Merge commit 'v2.6.28-rc2' into x86/pci-ioapic-boot-irq-quirks

12 files changed, 5704 insertions, 3693 deletions

diff --git a/drivers/misc/sgi-xp/Makefile b/drivers/misc/sgi-xp/Makefile
index b6e40a7958c..35ce2857807 100644
--- a/drivers/misc/sgi-xp/Makefile
+++ b/drivers/misc/sgi-xp/Makefile
@@ -3,9 +3,17 @@
 #
 
 obj-$(CONFIG_SGI_XP)		+= xp.o
-xp-y				:= xp_main.o xp_nofault.o
+xp-y				:= xp_main.o
+xp-$(CONFIG_IA64_SGI_SN2)	+= xp_sn2.o xp_nofault.o
+xp-$(CONFIG_IA64_GENERIC)	+= xp_sn2.o xp_nofault.o xp_uv.o
+xp-$(CONFIG_IA64_SGI_UV)	+= xp_uv.o
+xp-$(CONFIG_X86_64)		+= xp_uv.o
 
 obj-$(CONFIG_SGI_XP)		+= xpc.o
 xpc-y				:= xpc_main.o xpc_channel.o xpc_partition.o
+xpc-$(CONFIG_IA64_SGI_SN2)	+= xpc_sn2.o
+xpc-$(CONFIG_IA64_GENERIC)	+= xpc_sn2.o xpc_uv.o
+xpc-$(CONFIG_IA64_SGI_UV) 	+= xpc_uv.o
+xpc-$(CONFIG_X86_64)		+= xpc_uv.o
 
 obj-$(CONFIG_SGI_XP)		+= xpnet.o
diff --git a/drivers/misc/sgi-xp/xp.h b/drivers/misc/sgi-xp/xp.h
index 03a87a307e3..859a5281c61 100644
--- a/drivers/misc/sgi-xp/xp.h
+++ b/drivers/misc/sgi-xp/xp.h
@@ -13,11 +13,34 @@
 #ifndef _DRIVERS_MISC_SGIXP_XP_H
 #define _DRIVERS_MISC_SGIXP_XP_H
 
-#include <linux/cache.h>
-#include <linux/hardirq.h>
 #include <linux/mutex.h>
-#include <asm/sn/types.h>
-#include <asm/sn/bte.h>
+
+#ifdef CONFIG_IA64
+#include <asm/system.h>
+#include <asm/sn/arch.h>	/* defines is_shub1() and is_shub2() */
+#define is_shub()	ia64_platform_is("sn2")
+#define is_uv()		ia64_platform_is("uv")
+#endif
+#ifdef CONFIG_X86_64
+#include <asm/genapic.h>
+#define is_uv()		is_uv_system()
+#endif
+
+#ifndef is_shub1
+#define is_shub1()	0
+#endif
+
+#ifndef is_shub2
+#define is_shub2()	0
+#endif
+
+#ifndef is_shub
+#define is_shub()	0
+#endif
+
+#ifndef is_uv
+#define is_uv()		0
+#endif
 
 #ifdef USE_DBUG_ON
 #define DBUG_ON(condition)	BUG_ON(condition)
@@ -26,133 +49,56 @@
 #endif
 
 /*
- * Define the maximum number of logically defined partitions the system
- * can support. It is constrained by the maximum number of hardware
- * partitionable regions. The term 'region' in this context refers to the
- * minimum number of nodes that can comprise an access protection grouping.
- * The access protection is in regards to memory, IPI and IOI.
+ * Define the maximum number of partitions the system can possibly support.
+ * It is based on the maximum number of hardware partitionable regions. The
+ * term 'region' in this context refers to the minimum number of nodes that
+ * can comprise an access protection grouping. The access protection is in
+ * regards to memory, IPI and IOI.
  *
  * The maximum number of hardware partitionable regions is equal to the
  * maximum number of nodes in the entire system divided by the minimum number
  * of nodes that comprise an access protection grouping.
  */
-#define XP_MAX_PARTITIONS	64
-
-/*
- * Define the number of u64s required to represent all the C-brick nasids
- * as a bitmap.  The cross-partition kernel modules deal only with
- * C-brick nasids, thus the need for bitmaps which don't account for
- * odd-numbered (non C-brick) nasids.
- */
-#define XP_MAX_PHYSNODE_ID	(MAX_NUMALINK_NODES / 2)
-#define XP_NASID_MASK_BYTES	((XP_MAX_PHYSNODE_ID + 7) / 8)
-#define XP_NASID_MASK_WORDS	((XP_MAX_PHYSNODE_ID + 63) / 64)
-
-/*
- * Wrapper for bte_copy() that should it return a failure status will retry
- * the bte_copy() once in the hope that the failure was due to a temporary
- * aberration (i.e., the link going down temporarily).
- *
- * 	src - physical address of the source of the transfer.
- *	vdst - virtual address of the destination of the transfer.
- *	len - number of bytes to transfer from source to destination.
- *	mode - see bte_copy() for definition.
- *	notification - see bte_copy() for definition.
- *
- * Note: xp_bte_copy() should never be called while holding a spinlock.
- */
-static inline bte_result_t
-xp_bte_copy(u64 src, u64 vdst, u64 len, u64 mode, void *notification)
-{
-	bte_result_t ret;
-	u64 pdst = ia64_tpa(vdst);
-
-	/*
-	 * Ensure that the physically mapped memory is contiguous.
-	 *
-	 * We do this by ensuring that the memory is from region 7 only.
-	 * If the need should arise to use memory from one of the other
-	 * regions, then modify the BUG_ON() statement to ensure that the
-	 * memory from that region is always physically contiguous.
-	 */
-	BUG_ON(REGION_NUMBER(vdst) != RGN_KERNEL);
-
-	ret = bte_copy(src, pdst, len, mode, notification);
-	if ((ret != BTE_SUCCESS) && BTE_ERROR_RETRY(ret)) {
-		if (!in_interrupt())
-			cond_resched();
-
-		ret = bte_copy(src, pdst, len, mode, notification);
-	}
-
-	return ret;
-}
+#define XP_MAX_NPARTITIONS_SN2	64
+#define XP_MAX_NPARTITIONS_UV	256
 
 /*
  * XPC establishes channel connections between the local partition and any
  * other partition that is currently up. Over these channels, kernel-level
  * `users' can communicate with their counterparts on the other partitions.
  *
- * The maxinum number of channels is limited to eight. For performance reasons,
- * the internal cross partition structures require sixteen bytes per channel,
- * and eight allows all of this interface-shared info to fit in one cache line.
- *
- * XPC_NCHANNELS reflects the total number of channels currently defined.
  * If the need for additional channels arises, one can simply increase
- * XPC_NCHANNELS accordingly. If the day should come where that number
- * exceeds the MAXIMUM number of channels allowed (eight), then one will need
- * to make changes to the XPC code to allow for this.
+ * XPC_MAX_NCHANNELS accordingly. If the day should come where that number
+ * exceeds the absolute MAXIMUM number of channels possible (eight), then one
+ * will need to make changes to the XPC code to accommodate for this.
+ *
+ * The absolute maximum number of channels possible is limited to eight for
+ * performance reasons on sn2 hardware. The internal cross partition structures
+ * require sixteen bytes per channel, and eight allows all of this
+ * interface-shared info to fit in one 128-byte cacheline.
  */
 #define XPC_MEM_CHANNEL		0	/* memory channel number */
 #define	XPC_NET_CHANNEL		1	/* network channel number */
 
-#define	XPC_NCHANNELS		2	/* #of defined channels */
-#define XPC_MAX_NCHANNELS	8	/* max #of channels allowed */
+#define XPC_MAX_NCHANNELS	2	/* max #of channels allowed */
 
-#if XPC_NCHANNELS > XPC_MAX_NCHANNELS
-#error	XPC_NCHANNELS exceeds MAXIMUM allowed.
+#if XPC_MAX_NCHANNELS > 8
+#error	XPC_MAX_NCHANNELS exceeds absolute MAXIMUM possible.
 #endif
 
 /*
- * The format of an XPC message is as follows:
- *
- *      +-------+--------------------------------+
- *      | flags |////////////////////////////////|
- *      +-------+--------------------------------+
- *      |             message #                  |
- *      +----------------------------------------+
- *      |     payload (user-defined message)     |
- *      |                                        |
- *         		:
- *      |                                        |
- *      +----------------------------------------+
- *
- * The size of the payload is defined by the user via xpc_connect(). A user-
- * defined message resides in the payload area.
- *
- * The user should have no dealings with the message header, but only the
- * message's payload. When a message entry is allocated (via xpc_allocate())
- * a pointer to the payload area is returned and not the actual beginning of
- * the XPC message. The user then constructs a message in the payload area
- * and passes that pointer as an argument on xpc_send() or xpc_send_notify().
- *
- * The size of a message entry (within a message queue) must be a cacheline
- * sized multiple in order to facilitate the BTE transfer of messages from one
- * message queue to another. A macro, XPC_MSG_SIZE(), is provided for the user
+ * Define macro, XPC_MSG_SIZE(), is provided for the user
  * that wants to fit as many msg entries as possible in a given memory size
  * (e.g. a memory page).
  */
-struct xpc_msg {
-	u8 flags;		/* FOR XPC INTERNAL USE ONLY */
-	u8 reserved[7];		/* FOR XPC INTERNAL USE ONLY */
-	s64 number;		/* FOR XPC INTERNAL USE ONLY */
-
-	u64 payload;		/* user defined portion of message */
-};
+#define XPC_MSG_MAX_SIZE	128
+#define XPC_MSG_HDR_MAX_SIZE	16
+#define XPC_MSG_PAYLOAD_MAX_SIZE (XPC_MSG_MAX_SIZE - XPC_MSG_HDR_MAX_SIZE)
 
-#define XPC_MSG_PAYLOAD_OFFSET	(u64) (&((struct xpc_msg *)0)->payload)
 #define XPC_MSG_SIZE(_payload_size) \
-		L1_CACHE_ALIGN(XPC_MSG_PAYLOAD_OFFSET + (_payload_size))
+				ALIGN(XPC_MSG_HDR_MAX_SIZE + (_payload_size), \
+				      is_uv() ? 64 : 128)
+
 
 /*
  * Define the return values and values passed to user's callout functions.
@@ -233,8 +179,20 @@ enum xp_retval {
 	xpDisconnected,		/* 51: channel disconnected (closed) */
 
 	xpBteCopyError,		/* 52: bte_copy() returned error */
+	xpSalError,		/* 53: sn SAL error */
+	xpRsvdPageNotSet,	/* 54: the reserved page is not set up */
+	xpPayloadTooBig,	/* 55: payload too large for message slot */
+
+	xpUnsupported,		/* 56: unsupported functionality or resource */
+	xpNeedMoreInfo,		/* 57: more info is needed by SAL */
 
-	xpUnknownReason		/* 53: unknown reason - must be last in enum */
+	xpGruCopyError,		/* 58: gru_copy_gru() returned error */
+	xpGruSendMqError,	/* 59: gru send message queue related error */
+
+	xpBadChannelNumber,	/* 60: invalid channel number */
+	xpBadMsgType,		/* 60: invalid message type */
+
+	xpUnknownReason		/* 61: unknown reason - must be last in enum */
 };
 
 /*
@@ -285,6 +243,9 @@ typedef void (*xpc_channel_func) (enum xp_retval reason, short partid,
  * calling xpc_received().
  *
  * All other reason codes indicate failure.
+ *
+ * NOTE: The user defined function must be callable by an interrupt handler
+ *       and thus cannot block.
  */
 typedef void (*xpc_notify_func) (enum xp_retval reason, short partid,
 				 int ch_number, void *key);
@@ -308,23 +269,22 @@ struct xpc_registration {
 	xpc_channel_func func;	/* function to call */
 	void *key;		/* pointer to user's key */
 	u16 nentries;		/* #of msg entries in local msg queue */
-	u16 msg_size;		/* message queue's message size */
+	u16 entry_size;		/* message queue's message entry size */
 	u32 assigned_limit;	/* limit on #of assigned kthreads */
 	u32 idle_limit;		/* limit on #of idle kthreads */
 } ____cacheline_aligned;
 
 #define XPC_CHANNEL_REGISTERED(_c)	(xpc_registrations[_c].func != NULL)
 
-/* the following are valid xpc_allocate() flags */
+/* the following are valid xpc_send() or xpc_send_notify() flags */
 #define XPC_WAIT	0	/* wait flag */
 #define XPC_NOWAIT	1	/* no wait flag */
 
 struct xpc_interface {
 	void (*connect) (int);
 	void (*disconnect) (int);
-	enum xp_retval (*allocate) (short, int, u32, void **);
-	enum xp_retval (*send) (short, int, void *);
-	enum xp_retval (*send_notify) (short, int, void *,
+	enum xp_retval (*send) (short, int, u32, void *, u16);
+	enum xp_retval (*send_notify) (short, int, u32, void *, u16,
 					xpc_notify_func, void *);
 	void (*received) (short, int, void *);
 	enum xp_retval (*partid_to_nasids) (short, void *);
@@ -334,10 +294,9 @@ extern struct xpc_interface xpc_interface;
 
 extern void xpc_set_interface(void (*)(int),
 			      void (*)(int),
-			      enum xp_retval (*)(short, int, u32, void **),
-			      enum xp_retval (*)(short, int, void *),
-			      enum xp_retval (*)(short, int, void *,
-						  xpc_notify_func, void *),
+			      enum xp_retval (*)(short, int, u32, void *, u16),
+			      enum xp_retval (*)(short, int, u32, void *, u16,
+						 xpc_notify_func, void *),
 			      void (*)(short, int, void *),
 			      enum xp_retval (*)(short, void *));
 extern void xpc_clear_interface(void);
@@ -347,22 +306,19 @@ extern enum xp_retval xpc_connect(int, xpc_channel_func, void *, u16,
 extern void xpc_disconnect(int);
 
 static inline enum xp_retval
-xpc_allocate(short partid, int ch_number, u32 flags, void **payload)
-{
-	return xpc_interface.allocate(partid, ch_number, flags, payload);
-}
-
-static inline enum xp_retval
-xpc_send(short partid, int ch_number, void *payload)
+xpc_send(short partid, int ch_number, u32 flags, void *payload,
+	 u16 payload_size)
 {
-	return xpc_interface.send(partid, ch_number, payload);
+	return xpc_interface.send(partid, ch_number, flags, payload,
+				  payload_size);
 }
 
 static inline enum xp_retval
-xpc_send_notify(short partid, int ch_number, void *payload,
-		xpc_notify_func func, void *key)
+xpc_send_notify(short partid, int ch_number, u32 flags, void *payload,
+		u16 payload_size, xpc_notify_func func, void *key)
 {
-	return xpc_interface.send_notify(partid, ch_number, payload, func, key);
+	return xpc_interface.send_notify(partid, ch_number, flags, payload,
+					 payload_size, func, key);
 }
 
 static inline void
@@ -377,8 +333,23 @@ xpc_partid_to_nasids(short partid, void *nasids)
 	return xpc_interface.partid_to_nasids(partid, nasids);
 }
 
+extern short xp_max_npartitions;
+extern short xp_partition_id;
+extern u8 xp_region_size;
+
+extern unsigned long (*xp_pa) (void *);
+extern enum xp_retval (*xp_remote_memcpy) (unsigned long, const unsigned long,
+		       size_t);
+extern int (*xp_cpu_to_nasid) (int);
+
 extern u64 xp_nofault_PIOR_target;
 extern int xp_nofault_PIOR(void *);
 extern int xp_error_PIOR(void);
 
+extern struct device *xp;
+extern enum xp_retval xp_init_sn2(void);
+extern enum xp_retval xp_init_uv(void);
+extern void xp_exit_sn2(void);
+extern void xp_exit_uv(void);
+
 #endif /* _DRIVERS_MISC_SGIXP_XP_H */
diff --git a/drivers/misc/sgi-xp/xp_main.c b/drivers/misc/sgi-xp/xp_main.c
index 196480b691a..66a1d19e08a 100644
--- a/drivers/misc/sgi-xp/xp_main.c
+++ b/drivers/misc/sgi-xp/xp_main.c
@@ -14,29 +14,48 @@
  *
  */
 
-#include <linux/kernel.h>
-#include <linux/interrupt.h>
 #include <linux/module.h>
-#include <linux/mutex.h>
-#include <asm/sn/intr.h>
-#include <asm/sn/sn_sal.h>
+#include <linux/device.h>
 #include "xp.h"
 
-/*
- * The export of xp_nofault_PIOR needs to happen here since it is defined
- * in drivers/misc/sgi-xp/xp_nofault.S. The target of the nofault read is
- * defined here.
- */
-EXPORT_SYMBOL_GPL(xp_nofault_PIOR);
+/* define the XP debug device structures to be used with dev_dbg() et al */
+
+struct device_driver xp_dbg_name = {
+	.name = "xp"
+};
+
+struct device xp_dbg_subname = {
+	.bus_id = {0},		/* set to "" */
+	.driver = &xp_dbg_name
+};
+
+struct device *xp = &xp_dbg_subname;
+
+/* max #of partitions possible */
+short xp_max_npartitions;
+EXPORT_SYMBOL_GPL(xp_max_npartitions);
+
+short xp_partition_id;
+EXPORT_SYMBOL_GPL(xp_partition_id);
+
+u8 xp_region_size;
+EXPORT_SYMBOL_GPL(xp_region_size);
+
+unsigned long (*xp_pa) (void *addr);
+EXPORT_SYMBOL_GPL(xp_pa);
+
+enum xp_retval (*xp_remote_memcpy) (unsigned long dst_gpa,
+				    const unsigned long src_gpa, size_t len);
+EXPORT_SYMBOL_GPL(xp_remote_memcpy);
 
-u64 xp_nofault_PIOR_target;
-EXPORT_SYMBOL_GPL(xp_nofault_PIOR_target);
+int (*xp_cpu_to_nasid) (int cpuid);
+EXPORT_SYMBOL_GPL(xp_cpu_to_nasid);
 
 /*
  * xpc_registrations[] keeps track of xpc_connect()'s done by the kernel-level
  * users of XPC.
  */
-struct xpc_registration xpc_registrations[XPC_NCHANNELS];
+struct xpc_registration xpc_registrations[XPC_MAX_NCHANNELS];
 EXPORT_SYMBOL_GPL(xpc_registrations);
 
 /*
@@ -51,10 +70,9 @@ xpc_notloaded(void)
 struct xpc_interface xpc_interface = {
 	(void (*)(int))xpc_notloaded,
 	(void (*)(int))xpc_notloaded,
-	(enum xp_retval(*)(short, int, u32, void **))xpc_notloaded,
-	(enum xp_retval(*)(short, int, void *))xpc_notloaded,
-	(enum xp_retval(*)(short, int, void *, xpc_notify_func, void *))
-	    xpc_notloaded,
+	(enum xp_retval(*)(short, int, u32, void *, u16))xpc_notloaded,
+	(enum xp_retval(*)(short, int, u32, void *, u16, xpc_notify_func,
+			   void *))xpc_notloaded,
 	(void (*)(short, int, void *))xpc_notloaded,
 	(enum xp_retval(*)(short, void *))xpc_notloaded
 };
@@ -66,16 +84,14 @@ EXPORT_SYMBOL_GPL(xpc_interface);
 void
 xpc_set_interface(void (*connect) (int),
 		  void (*disconnect) (int),
-		  enum xp_retval (*allocate) (short, int, u32, void **),
-		  enum xp_retval (*send) (short, int, void *),
-		  enum xp_retval (*send_notify) (short, int, void *,
+		  enum xp_retval (*send) (short, int, u32, void *, u16),
+		  enum xp_retval (*send_notify) (short, int, u32, void *, u16,
 						  xpc_notify_func, void *),
 		  void (*received) (short, int, void *),
 		  enum xp_retval (*partid_to_nasids) (short, void *))
 {
 	xpc_interface.connect = connect;
 	xpc_interface.disconnect = disconnect;
-	xpc_interface.allocate = allocate;
 	xpc_interface.send = send;
 	xpc_interface.send_notify = send_notify;
 	xpc_interface.received = received;
@@ -91,13 +107,11 @@ xpc_clear_interface(void)
 {
 	xpc_interface.connect = (void (*)(int))xpc_notloaded;
 	xpc_interface.disconnect = (void (*)(int))xpc_notloaded;
-	xpc_interface.allocate = (enum xp_retval(*)(short, int, u32,
-						     void **))xpc_notloaded;
-	xpc_interface.send = (enum xp_retval(*)(short, int, void *))
+	xpc_interface.send = (enum xp_retval(*)(short, int, u32, void *, u16))
 	    xpc_notloaded;
-	xpc_interface.send_notify = (enum xp_retval(*)(short, int, void *,
-							xpc_notify_func,
-							void *))xpc_notloaded;
+	xpc_interface.send_notify = (enum xp_retval(*)(short, int, u32, void *,
+						       u16, xpc_notify_func,
+						       void *))xpc_notloaded;
 	xpc_interface.received = (void (*)(short, int, void *))
 	    xpc_notloaded;
 	xpc_interface.partid_to_nasids = (enum xp_retval(*)(short, void *))
@@ -135,11 +149,14 @@ xpc_connect(int ch_number, xpc_channel_func func, void *key, u16 payload_size,
 {
 	struct xpc_registration *registration;
 
-	DBUG_ON(ch_number < 0 || ch_number >= XPC_NCHANNELS);
+	DBUG_ON(ch_number < 0 || ch_number >= XPC_MAX_NCHANNELS);
 	DBUG_ON(payload_size == 0 || nentries == 0);
 	DBUG_ON(func == NULL);
 	DBUG_ON(assigned_limit == 0 || idle_limit > assigned_limit);
 
+	if (XPC_MSG_SIZE(payload_size) > XPC_MSG_MAX_SIZE)
+		return xpPayloadTooBig;
+
 	registration = &xpc_registrations[ch_number];
 
 	if (mutex_lock_interruptible(&registration->mutex) != 0)
@@ -152,7 +169,7 @@ xpc_connect(int ch_number, xpc_channel_func func, void *key, u16 payload_size,
 	}
 
 	/* register the channel for connection */
-	registration->msg_size = XPC_MSG_SIZE(payload_size);
+	registration->entry_size = XPC_MSG_SIZE(payload_size);
 	registration->nentries = nentries;
 	registration->assigned_limit = assigned_limit;
 	registration->idle_limit = idle_limit;
@@ -185,7 +202,7 @@ xpc_disconnect(int ch_number)
 {
 	struct xpc_registration *registration;
 
-	DBUG_ON(ch_number < 0 || ch_number >= XPC_NCHANNELS);
+	DBUG_ON(ch_number < 0 || ch_number >= XPC_MAX_NCHANNELS);
 
 	registration = &xpc_registrations[ch_number];
 
@@ -206,7 +223,7 @@ xpc_disconnect(int ch_number)
 	registration->func = NULL;
 	registration->key = NULL;
 	registration->nentries = 0;
-	registration->msg_size = 0;
+	registration->entry_size = 0;
 	registration->assigned_limit = 0;
 	registration->idle_limit = 0;
 
@@ -221,39 +238,21 @@ EXPORT_SYMBOL_GPL(xpc_disconnect);
 int __init
 xp_init(void)
 {
-	int ret, ch_number;
-	u64 func_addr = *(u64 *)xp_nofault_PIOR;
-	u64 err_func_addr = *(u64 *)xp_error_PIOR;
-
-	if (!ia64_platform_is("sn2"))
-		return -ENODEV;
+	enum xp_retval ret;
+	int ch_number;
 
-	/*
-	 * Register a nofault code region which performs a cross-partition
-	 * PIO read. If the PIO read times out, the MCA handler will consume
-	 * the error and return to a kernel-provided instruction to indicate
-	 * an error. This PIO read exists because it is guaranteed to timeout
-	 * if the destination is down (AMO operations do not timeout on at
-	 * least some CPUs on Shubs <= v1.2, which unfortunately we have to
-	 * work around).
-	 */
-	ret = sn_register_nofault_code(func_addr, err_func_addr, err_func_addr,
-				       1, 1);
-	if (ret != 0) {
-		printk(KERN_ERR "XP: can't register nofault code, error=%d\n",
-		       ret);
-	}
-	/*
-	 * Setup the nofault PIO read target. (There is no special reason why
-	 * SH_IPI_ACCESS was selected.)
-	 */
-	if (is_shub2())
-		xp_nofault_PIOR_target = SH2_IPI_ACCESS0;
+	if (is_shub())
+		ret = xp_init_sn2();
+	else if (is_uv())
+		ret = xp_init_uv();
 	else
-		xp_nofault_PIOR_target = SH1_IPI_ACCESS;
+		ret = xpUnsupported;
+
+	if (ret != xpSuccess)
+		return -ENODEV;
 
 	/* initialize the connection registration mutex */
-	for (ch_number = 0; ch_number < XPC_NCHANNELS; ch_number++)
+	for (ch_number = 0; ch_number < XPC_MAX_NCHANNELS; ch_number++)
 		mutex_init(&xpc_registrations[ch_number].mutex);
 
 	return 0;
@@ -264,12 +263,10 @@ module_init(xp_init);
 void __exit
 xp_exit(void)
 {
-	u64 func_addr = *(u64 *)xp_nofault_PIOR;
-	u64 err_func_addr = *(u64 *)xp_error_PIOR;
-
-	/* unregister the PIO read nofault code region */
-	(void)sn_register_nofault_code(func_addr, err_func_addr,
-				       err_func_addr, 1, 0);
+	if (is_shub())
+		xp_exit_sn2();
+	else if (is_uv())
+		xp_exit_uv();
 }
 
 module_exit(xp_exit);
diff --git a/drivers/misc/sgi-xp/xp_sn2.c b/drivers/misc/sgi-xp/xp_sn2.c
new file mode 100644
index 00000000000..1440134caf3
--- /dev/null
+++ b/drivers/misc/sgi-xp/xp_sn2.c
@@ -0,0 +1,146 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (c) 2008 Silicon Graphics, Inc.  All Rights Reserved.
+ */
+
+/*
+ * Cross Partition (XP) sn2-based functions.
+ *
+ *      Architecture specific implementation of common functions.
+ */
+
+#include <linux/module.h>
+#include <linux/device.h>
+#include <asm/sn/bte.h>
+#include <asm/sn/sn_sal.h>
+#include "xp.h"
+
+/*
+ * The export of xp_nofault_PIOR needs to happen here since it is defined
+ * in drivers/misc/sgi-xp/xp_nofault.S. The target of the nofault read is
+ * defined here.
+ */
+EXPORT_SYMBOL_GPL(xp_nofault_PIOR);
+
+u64 xp_nofault_PIOR_target;
+EXPORT_SYMBOL_GPL(xp_nofault_PIOR_target);
+
+/*
+ * Register a nofault code region which performs a cross-partition PIO read.
+ * If the PIO read times out, the MCA handler will consume the error and
+ * return to a kernel-provided instruction to indicate an error. This PIO read
+ * exists because it is guaranteed to timeout if the destination is down
+ * (amo operations do not timeout on at least some CPUs on Shubs <= v1.2,
+ * which unfortunately we have to work around).
+ */
+static enum xp_retval
+xp_register_nofault_code_sn2(void)
+{
+	int ret;
+	u64 func_addr;
+	u64 err_func_addr;
+
+	func_addr = *(u64 *)xp_nofault_PIOR;
+	err_func_addr = *(u64 *)xp_error_PIOR;
+	ret = sn_register_nofault_code(func_addr, err_func_addr, err_func_addr,
+				       1, 1);
+	if (ret != 0) {
+		dev_err(xp, "can't register nofault code, error=%d\n", ret);
+		return xpSalError;
+	}
+	/*
+	 * Setup the nofault PIO read target. (There is no special reason why
+	 * SH_IPI_ACCESS was selected.)
+	 */
+	if (is_shub1())
+		xp_nofault_PIOR_target = SH1_IPI_ACCESS;
+	else if (is_shub2())
+		xp_nofault_PIOR_target = SH2_IPI_ACCESS0;
+
+	return xpSuccess;
+}
+
+static void
+xp_unregister_nofault_code_sn2(void)
+{
+	u64 func_addr = *(u64 *)xp_nofault_PIOR;
+	u64 err_func_addr = *(u64 *)xp_error_PIOR;
+
+	/* unregister the PIO read nofault code region */
+	(void)sn_register_nofault_code(func_addr, err_func_addr,
+				       err_func_addr, 1, 0);
+}
+
+/*
+ * Convert a virtual memory address to a physical memory address.
+ */
+static unsigned long
+xp_pa_sn2(void *addr)
+{
+	return __pa(addr);
+}
+
+/*
+ * Wrapper for bte_copy().
+ *
+ *	dst_pa - physical address of the destination of the transfer.
+ *	src_pa - physical address of the source of the transfer.
+ *	len - number of bytes to transfer from source to destination.
+ *
+ * Note: xp_remote_memcpy_sn2() should never be called while holding a spinlock.
+ */
+static enum xp_retval
+xp_remote_memcpy_sn2(unsigned long dst_pa, const unsigned long src_pa,
+		     size_t len)
+{
+	bte_result_t ret;
+
+	ret = bte_copy(src_pa, dst_pa, len, (BTE_NOTIFY | BTE_WACQUIRE), NULL);
+	if (ret == BTE_SUCCESS)
+		return xpSuccess;
+
+	if (is_shub2()) {
+		dev_err(xp, "bte_copy() on shub2 failed, error=0x%x dst_pa="
+			"0x%016lx src_pa=0x%016lx len=%ld\\n", ret, dst_pa,
+			src_pa, len);
+	} else {
+		dev_err(xp, "bte_copy() failed, error=%d dst_pa=0x%016lx "
+			"src_pa=0x%016lx len=%ld\\n", ret, dst_pa, src_pa, len);
+	}
+
+	return xpBteCopyError;
+}
+
+static int
+xp_cpu_to_nasid_sn2(int cpuid)
+{
+	return cpuid_to_nasid(cpuid);
+}
+
+enum xp_retval
+xp_init_sn2(void)
+{
+	BUG_ON(!is_shub());
+
+	xp_max_npartitions = XP_MAX_NPARTITIONS_SN2;
+	xp_partition_id = sn_partition_id;
+	xp_region_size = sn_region_size;
+
+	xp_pa = xp_pa_sn2;
+	xp_remote_memcpy = xp_remote_memcpy_sn2;
+	xp_cpu_to_nasid = xp_cpu_to_nasid_sn2;
+
+	return xp_register_nofault_code_sn2();
+}
+
+void
+xp_exit_sn2(void)
+{
+	BUG_ON(!is_shub());
+
+	xp_unregister_nofault_code_sn2();
+}
+
diff --git a/drivers/misc/sgi-xp/xp_uv.c b/drivers/misc/sgi-xp/xp_uv.c
new file mode 100644
index 00000000000..d9f7ce2510b
--- /dev/null
+++ b/drivers/misc/sgi-xp/xp_uv.c
@@ -0,0 +1,72 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (c) 2008 Silicon Graphics, Inc.  All Rights Reserved.
+ */
+
+/*
+ * Cross Partition (XP) uv-based functions.
+ *
+ *      Architecture specific implementation of common functions.
+ *
+ */
+
+#include <linux/device.h>
+#include <asm/uv/uv_hub.h>
+#include "../sgi-gru/grukservices.h"
+#include "xp.h"
+
+/*
+ * Convert a virtual memory address to a physical memory address.
+ */
+static unsigned long
+xp_pa_uv(void *addr)
+{
+	return uv_gpa(addr);
+}
+
+static enum xp_retval
+xp_remote_memcpy_uv(unsigned long dst_gpa, const unsigned long src_gpa,
+		    size_t len)
+{
+	int ret;
+
+	ret = gru_copy_gpa(dst_gpa, src_gpa, len);
+	if (ret == 0)
+		return xpSuccess;
+
+	dev_err(xp, "gru_copy_gpa() failed, dst_gpa=0x%016lx src_gpa=0x%016lx "
+		"len=%ld\n", dst_gpa, src_gpa, len);
+	return xpGruCopyError;
+}
+
+static int
+xp_cpu_to_nasid_uv(int cpuid)
+{
+	/* ??? Is this same as sn2 nasid in mach/part bitmaps set up by SAL? */
+	return UV_PNODE_TO_NASID(uv_cpu_to_pnode(cpuid));
+}
+
+enum xp_retval
+xp_init_uv(void)
+{
+	BUG_ON(!is_uv());
+
+	xp_max_npartitions = XP_MAX_NPARTITIONS_UV;
+	xp_partition_id = 0;	/* !!! not correct value */
+	xp_region_size = 0;	/* !!! not correct value */
+
+	xp_pa = xp_pa_uv;
+	xp_remote_memcpy = xp_remote_memcpy_uv;
+	xp_cpu_to_nasid = xp_cpu_to_nasid_uv;
+
+	return xpSuccess;
+}
+
+void
+xp_exit_uv(void)
+{
+	BUG_ON(!is_uv());
+}
diff --git a/drivers/misc/sgi-xp/xpc.h b/drivers/misc/sgi-xp/xpc.h
index 11ac267ed68..619208d6186 100644
--- a/drivers/misc/sgi-xp/xpc.h
+++ b/drivers/misc/sgi-xp/xpc.h
@@ -13,18 +13,10 @@
 #ifndef _DRIVERS_MISC_SGIXP_XPC_H
 #define _DRIVERS_MISC_SGIXP_XPC_H
 
-#include <linux/interrupt.h>
-#include <linux/sysctl.h>
-#include <linux/device.h>
-#include <linux/mutex.h>
+#include <linux/wait.h>
 #include <linux/completion.h>
-#include <asm/pgtable.h>
-#include <asm/processor.h>
-#include <asm/sn/bte.h>
-#include <asm/sn/clksupport.h>
-#include <asm/sn/addrs.h>
-#include <asm/sn/mspec.h>
-#include <asm/sn/shub_mmr.h>
+#include <linux/timer.h>
+#include <linux/sched.h>
 #include "xp.h"
 
 /*
@@ -36,23 +28,7 @@
 #define XPC_VERSION_MAJOR(_v)		((_v) >> 4)
 #define XPC_VERSION_MINOR(_v)		((_v) & 0xf)
 
-/*
- * The next macros define word or bit representations for given
- * C-brick nasid in either the SAL provided bit array representing
- * nasids in the partition/machine or the AMO_t array used for
- * inter-partition initiation communications.
- *
- * For SN2 machines, C-Bricks are alway even numbered NASIDs.  As
- * such, some space will be saved by insisting that nasid information
- * passed from SAL always be packed for C-Bricks and the
- * cross-partition interrupts use the same packing scheme.
- */
-#define XPC_NASID_W_INDEX(_n)	(((_n) / 64) / 2)
-#define XPC_NASID_B_INDEX(_n)	(((_n) / 2) & (64 - 1))
-#define XPC_NASID_IN_ARRAY(_n, _p) ((_p)[XPC_NASID_W_INDEX(_n)] & \
-				    (1UL << XPC_NASID_B_INDEX(_n)))
-#define XPC_NASID_FROM_W_B(_w, _b) (((_w) * 64 + (_b)) * 2)
-
+/* define frequency of the heartbeat and frequency how often it's checked */
 #define XPC_HB_DEFAULT_INTERVAL		5	/* incr HB every x secs */
 #define XPC_HB_CHECK_DEFAULT_INTERVAL	20	/* check HB every x secs */
 
@@ -72,11 +48,11 @@
  *
  *   reserved page header
  *
- *     The first cacheline of the reserved page contains the header
- *     (struct xpc_rsvd_page). Before SAL initialization has completed,
+ *     The first two 64-byte cachelines of the reserved page contain the
+ *     header (struct xpc_rsvd_page). Before SAL initialization has completed,
  *     SAL has set up the following fields of the reserved page header:
- *     SAL_signature, SAL_version, partid, and nasids_size. The other
- *     fields are set up by XPC. (xpc_rsvd_page points to the local
+ *     SAL_signature, SAL_version, SAL_partid, and SAL_nasids_size. The
+ *     other fields are set up by XPC. (xpc_rsvd_page points to the local
  *     partition's reserved page.)
  *
  *   part_nasids mask
@@ -87,14 +63,16 @@
  *     the actual nasids in the entire machine (mach_nasids). We're only
  *     interested in the even numbered nasids (which contain the processors
  *     and/or memory), so we only need half as many bits to represent the
- *     nasids. The part_nasids mask is located starting at the first cacheline
- *     following the reserved page header. The mach_nasids mask follows right
- *     after the part_nasids mask. The size in bytes of each mask is reflected
- *     by the reserved page header field 'nasids_size'. (Local partition's
- *     mask pointers are xpc_part_nasids and xpc_mach_nasids.)
+ *     nasids. When mapping nasid to bit in a mask (or bit to nasid) be sure
+ *     to either divide or multiply by 2. The part_nasids mask is located
+ *     starting at the first cacheline following the reserved page header. The
+ *     mach_nasids mask follows right after the part_nasids mask. The size in
+ *     bytes of each mask is reflected by the reserved page header field
+ *     'SAL_nasids_size'. (Local partition's mask pointers are xpc_part_nasids
+ *     and xpc_mach_nasids.)
  *
- *   vars
- *   vars part
+ *   vars	(ia64-sn2 only)
+ *   vars part	(ia64-sn2 only)
  *
  *     Immediately following the mach_nasids mask are the XPC variables
  *     required by other partitions. First are those that are generic to all
@@ -102,43 +80,26 @@
  *     which are partition specific (vars part). These are setup by XPC.
  *     (Local partition's vars pointers are xpc_vars and xpc_vars_part.)
  *
- * Note: Until vars_pa is set, the partition XPC code has not been initialized.
+ * Note: Until 'ts_jiffies' is set non-zero, the partition XPC code has not been
+ *       initialized.
  */
 struct xpc_rsvd_page {
 	u64 SAL_signature;	/* SAL: unique signature */
 	u64 SAL_version;	/* SAL: version */
-	u8 partid;		/* SAL: partition ID */
+	short SAL_partid;	/* SAL: partition ID */
+	short max_npartitions;	/* value of XPC_MAX_PARTITIONS */
 	u8 version;
-	u8 pad1[6];		/* align to next u64 in cacheline */
-	u64 vars_pa;		/* physical address of struct xpc_vars */
-	struct timespec stamp;	/* time when reserved page was setup by XPC */
-	u64 pad2[9];		/* align to last u64 in cacheline */
-	u64 nasids_size;	/* SAL: size of each nasid mask in bytes */
+	u8 pad1[3];		/* align to next u64 in 1st 64-byte cacheline */
+	union {
+		unsigned long vars_pa;	/* phys address of struct xpc_vars */
+		unsigned long activate_mq_gpa; /* gru phy addr of activate_mq */
+	} sn;
+	unsigned long ts_jiffies; /* timestamp when rsvd pg was setup by XPC */
+	u64 pad2[10];		/* align to last u64 in 2nd 64-byte cacheline */
+	u64 SAL_nasids_size;	/* SAL: size of each nasid mask in bytes */
 };
 
-#define XPC_RP_VERSION _XPC_VERSION(1, 1) /* version 1.1 of the reserved page */
-
-#define XPC_SUPPORTS_RP_STAMP(_version) \
-			(_version >= _XPC_VERSION(1, 1))
-
-/*
- * compare stamps - the return value is:
- *
- *	< 0,	if stamp1 < stamp2
- *	= 0,	if stamp1 == stamp2
- *	> 0,	if stamp1 > stamp2
- */
-static inline int
-xpc_compare_stamps(struct timespec *stamp1, struct timespec *stamp2)
-{
-	int ret;
-
-	ret = stamp1->tv_sec - stamp2->tv_sec;
-	if (ret == 0)
-		ret = stamp1->tv_nsec - stamp2->tv_nsec;
-
-	return ret;
-}
+#define XPC_RP_VERSION _XPC_VERSION(2, 0) /* version 2.0 of the reserved page */
 
 /*
  * Define the structures by which XPC variables can be exported to other
@@ -154,85 +115,40 @@ xpc_compare_stamps(struct timespec *stamp1, struct timespec *stamp2)
  * reflected by incrementing either the major or minor version numbers
  * of struct xpc_vars.
  */
-struct xpc_vars {
+struct xpc_vars_sn2 {
 	u8 version;
 	u64 heartbeat;
-	u64 heartbeating_to_mask;
+	DECLARE_BITMAP(heartbeating_to_mask, XP_MAX_NPARTITIONS_SN2);
 	u64 heartbeat_offline;	/* if 0, heartbeat should be changing */
-	int act_nasid;
-	int act_phys_cpuid;
-	u64 vars_part_pa;
-	u64 amos_page_pa;	/* paddr of page of AMOs from MSPEC driver */
-	AMO_t *amos_page;	/* vaddr of page of AMOs from MSPEC driver */
+	int activate_IRQ_nasid;
+	int activate_IRQ_phys_cpuid;
+	unsigned long vars_part_pa;
+	unsigned long amos_page_pa;/* paddr of page of amos from MSPEC driver */
+	struct amo *amos_page;	/* vaddr of page of amos from MSPEC driver */
 };
 
 #define XPC_V_VERSION _XPC_VERSION(3, 1)    /* version 3.1 of the cross vars */
 
-#define XPC_SUPPORTS_DISENGAGE_REQUEST(_version) \
-			(_version >= _XPC_VERSION(3, 1))
-
-static inline int
-xpc_hb_allowed(short partid, struct xpc_vars *vars)
-{
-	return ((vars->heartbeating_to_mask & (1UL << partid)) != 0);
-}
-
-static inline void
-xpc_allow_hb(short partid, struct xpc_vars *vars)
-{
-	u64 old_mask, new_mask;
-
-	do {
-		old_mask = vars->heartbeating_to_mask;
-		new_mask = (old_mask | (1UL << partid));
-	} while (cmpxchg(&vars->heartbeating_to_mask, old_mask, new_mask) !=
-		 old_mask);
-}
-
-static inline void
-xpc_disallow_hb(short partid, struct xpc_vars *vars)
-{
-	u64 old_mask, new_mask;
-
-	do {
-		old_mask = vars->heartbeating_to_mask;
-		new_mask = (old_mask & ~(1UL << partid));
-	} while (cmpxchg(&vars->heartbeating_to_mask, old_mask, new_mask) !=
-		 old_mask);
-}
-
-/*
- * The AMOs page consists of a number of AMO variables which are divided into
- * four groups, The first two groups are used to identify an IRQ's sender.
- * These two groups consist of 64 and 128 AMO variables respectively. The last
- * two groups, consisting of just one AMO variable each, are used to identify
- * the remote partitions that are currently engaged (from the viewpoint of
- * the XPC running on the remote partition).
- */
-#define XPC_NOTIFY_IRQ_AMOS	   0
-#define XPC_ACTIVATE_IRQ_AMOS	   (XPC_NOTIFY_IRQ_AMOS + XP_MAX_PARTITIONS)
-#define XPC_ENGAGED_PARTITIONS_AMO (XPC_ACTIVATE_IRQ_AMOS + XP_NASID_MASK_WORDS)
-#define XPC_DISENGAGE_REQUEST_AMO  (XPC_ENGAGED_PARTITIONS_AMO + 1)
-
 /*
  * The following structure describes the per partition specific variables.
  *
  * An array of these structures, one per partition, will be defined. As a
  * partition becomes active XPC will copy the array entry corresponding to
- * itself from that partition. It is desirable that the size of this
- * structure evenly divide into a cacheline, such that none of the entries
- * in this array crosses a cacheline boundary. As it is now, each entry
- * occupies half a cacheline.
+ * itself from that partition. It is desirable that the size of this structure
+ * evenly divides into a 128-byte cacheline, such that none of the entries in
+ * this array crosses a 128-byte cacheline boundary. As it is now, each entry
+ * occupies 64-bytes.
  */
-struct xpc_vars_part {
+struct xpc_vars_part_sn2 {
 	u64 magic;
 
-	u64 openclose_args_pa;	/* physical address of open and close args */
-	u64 GPs_pa;		/* physical address of Get/Put values */
+	unsigned long openclose_args_pa; /* phys addr of open and close args */
+	unsigned long GPs_pa;	/* physical address of Get/Put values */
+
+	unsigned long chctl_amo_pa; /* physical address of chctl flags' amo */
 
-	u64 IPI_amo_pa;		/* physical address of IPI AMO_t structure */
-	int IPI_nasid;		/* nasid of where to send IPIs */
-	int IPI_phys_cpuid;	/* physical CPU ID of where to send IPIs */
+	int notify_IRQ_nasid;	/* nasid of where to send notify IRQs */
+	int notify_IRQ_phys_cpuid;	/* CPUID of where to send notify IRQs */
 
 	u8 nchannels;		/* #of defined channels supported */
 
@@ -248,20 +164,95 @@ struct xpc_vars_part {
  * MAGIC2 indicates that this partition has pulled the remote partititions
  * per partition variables that pertain to this partition.
  */
-#define XPC_VP_MAGIC1	0x0053524156435058L   /* 'XPCVARS\0'L (little endian) */
-#define XPC_VP_MAGIC2	0x0073726176435058L   /* 'XPCvars\0'L (little endian) */
+#define XPC_VP_MAGIC1_SN2 0x0053524156435058L /* 'XPCVARS\0'L (little endian) */
+#define XPC_VP_MAGIC2_SN2 0x0073726176435058L /* 'XPCvars\0'L (little endian) */
 
 /* the reserved page sizes and offsets */
 
 #define XPC_RP_HEADER_SIZE	L1_CACHE_ALIGN(sizeof(struct xpc_rsvd_page))
-#define XPC_RP_VARS_SIZE	L1_CACHE_ALIGN(sizeof(struct xpc_vars))
+#define XPC_RP_VARS_SIZE	L1_CACHE_ALIGN(sizeof(struct xpc_vars_sn2))
 
-#define XPC_RP_PART_NASIDS(_rp) ((u64 *)((u8 *)(_rp) + XPC_RP_HEADER_SIZE))
-#define XPC_RP_MACH_NASIDS(_rp) (XPC_RP_PART_NASIDS(_rp) + xp_nasid_mask_words)
-#define XPC_RP_VARS(_rp)	((struct xpc_vars *)(XPC_RP_MACH_NASIDS(_rp) + \
-				    xp_nasid_mask_words))
-#define XPC_RP_VARS_PART(_rp)	((struct xpc_vars_part *) \
-				    ((u8 *)XPC_RP_VARS(_rp) + XPC_RP_VARS_SIZE))
+#define XPC_RP_PART_NASIDS(_rp) ((unsigned long *)((u8 *)(_rp) + \
+				 XPC_RP_HEADER_SIZE))
+#define XPC_RP_MACH_NASIDS(_rp) (XPC_RP_PART_NASIDS(_rp) + \
+				 xpc_nasid_mask_nlongs)
+#define XPC_RP_VARS(_rp)	((struct xpc_vars_sn2 *) \
+				 (XPC_RP_MACH_NASIDS(_rp) + \
+				  xpc_nasid_mask_nlongs))
+
+/*
+ * The activate_mq is used to send/receive GRU messages that affect XPC's
+ * heartbeat, partition active state, and channel state. This is UV only.
+ */
+struct xpc_activate_mq_msghdr_uv {
+	short partid;		/* sender's partid */
+	u8 act_state;		/* sender's act_state at time msg sent */
+	u8 type;		/* message's type */
+	unsigned long rp_ts_jiffies; /* timestamp of sender's rp setup by XPC */
+};
+
+/* activate_mq defined message types */
+#define XPC_ACTIVATE_MQ_MSG_SYNC_ACT_STATE_UV		0
+#define XPC_ACTIVATE_MQ_MSG_INC_HEARTBEAT_UV		1
+#define XPC_ACTIVATE_MQ_MSG_OFFLINE_HEARTBEAT_UV	2
+#define XPC_ACTIVATE_MQ_MSG_ONLINE_HEARTBEAT_UV		3
+
+#define XPC_ACTIVATE_MQ_MSG_ACTIVATE_REQ_UV		4
+#define XPC_ACTIVATE_MQ_MSG_DEACTIVATE_REQ_UV		5
+
+#define XPC_ACTIVATE_MQ_MSG_CHCTL_CLOSEREQUEST_UV	6
+#define XPC_ACTIVATE_MQ_MSG_CHCTL_CLOSEREPLY_UV		7
+#define XPC_ACTIVATE_MQ_MSG_CHCTL_OPENREQUEST_UV	8
+#define XPC_ACTIVATE_MQ_MSG_CHCTL_OPENREPLY_UV		9
+
+#define XPC_ACTIVATE_MQ_MSG_MARK_ENGAGED_UV		10
+#define XPC_ACTIVATE_MQ_MSG_MARK_DISENGAGED_UV		11
+
+struct xpc_activate_mq_msg_uv {
+	struct xpc_activate_mq_msghdr_uv hdr;
+};
+
+struct xpc_activate_mq_msg_heartbeat_req_uv {
+	struct xpc_activate_mq_msghdr_uv hdr;
+	u64 heartbeat;
+};
+
+struct xpc_activate_mq_msg_activate_req_uv {
+	struct xpc_activate_mq_msghdr_uv hdr;
+	unsigned long rp_gpa;
+	unsigned long activate_mq_gpa;
+};
+
+struct xpc_activate_mq_msg_deactivate_req_uv {
+	struct xpc_activate_mq_msghdr_uv hdr;
+	enum xp_retval reason;
+};
+
+struct xpc_activate_mq_msg_chctl_closerequest_uv {
+	struct xpc_activate_mq_msghdr_uv hdr;
+	short ch_number;
+	enum xp_retval reason;
+};
+
+struct xpc_activate_mq_msg_chctl_closereply_uv {
+	struct xpc_activate_mq_msghdr_uv hdr;
+	short ch_number;
+};
+
+struct xpc_activate_mq_msg_chctl_openrequest_uv {
+	struct xpc_activate_mq_msghdr_uv hdr;
+	short ch_number;
+	short entry_size;	/* size of notify_mq's GRU messages */
+	short local_nentries;	/* ??? Is this needed? What is? */
+};
+
+struct xpc_activate_mq_msg_chctl_openreply_uv {
+	struct xpc_activate_mq_msghdr_uv hdr;
+	short ch_number;
+	short remote_nentries;	/* ??? Is this needed? What is? */
+	short local_nentries;	/* ??? Is this needed? What is? */
+	unsigned long local_notify_mq_gpa;
+};
 
 /*
  * Functions registered by add_timer() or called by kernel_thread() only
@@ -270,22 +261,22 @@ struct xpc_vars_part {
  * the passed argument.
  */
 #define XPC_PACK_ARGS(_arg1, _arg2) \
-			((((u64) _arg1) & 0xffffffff) | \
-			((((u64) _arg2) & 0xffffffff) << 32))
+			((((u64)_arg1) & 0xffffffff) | \
+			((((u64)_arg2) & 0xffffffff) << 32))
 
-#define XPC_UNPACK_ARG1(_args)	(((u64) _args) & 0xffffffff)
-#define XPC_UNPACK_ARG2(_args)	((((u64) _args) >> 32) & 0xffffffff)
+#define XPC_UNPACK_ARG1(_args)	(((u64)_args) & 0xffffffff)
+#define XPC_UNPACK_ARG2(_args)	((((u64)_args) >> 32) & 0xffffffff)
 
 /*
  * Define a Get/Put value pair (pointers) used with a message queue.
  */
-struct xpc_gp {
+struct xpc_gp_sn2 {
 	s64 get;		/* Get value */
 	s64 put;		/* Put value */
 };
 
 #define XPC_GP_SIZE \
-		L1_CACHE_ALIGN(sizeof(struct xpc_gp) * XPC_NCHANNELS)
+		L1_CACHE_ALIGN(sizeof(struct xpc_gp_sn2) * XPC_MAX_NCHANNELS)
 
 /*
  * Define a structure that contains arguments associated with opening and
@@ -293,31 +284,89 @@ struct xpc_gp {
  */
 struct xpc_openclose_args {
 	u16 reason;		/* reason why channel is closing */
-	u16 msg_size;		/* sizeof each message entry */
+	u16 entry_size;		/* sizeof each message entry */
 	u16 remote_nentries;	/* #of message entries in remote msg queue */
 	u16 local_nentries;	/* #of message entries in local msg queue */
-	u64 local_msgqueue_pa;	/* physical address of local message queue */
+	unsigned long local_msgqueue_pa; /* phys addr of local message queue */
 };
 
 #define XPC_OPENCLOSE_ARGS_SIZE \
-	      L1_CACHE_ALIGN(sizeof(struct xpc_openclose_args) * XPC_NCHANNELS)
+	      L1_CACHE_ALIGN(sizeof(struct xpc_openclose_args) * \
+	      XPC_MAX_NCHANNELS)
 
-/* struct xpc_msg flags */
 
-#define	XPC_M_DONE		0x01	/* msg has been received/consumed */
-#define	XPC_M_READY		0x02	/* msg is ready to be sent */
-#define	XPC_M_INTERRUPT		0x04	/* send interrupt when msg consumed */
+/*
+ * Structures to define a fifo singly-linked list.
+ */
 
-#define XPC_MSG_ADDRESS(_payload) \
-		((struct xpc_msg *)((u8 *)(_payload) - XPC_MSG_PAYLOAD_OFFSET))
+struct xpc_fifo_entry_uv {
+	struct xpc_fifo_entry_uv *next;
+};
+
+struct xpc_fifo_head_uv {
+	struct xpc_fifo_entry_uv *first;
+	struct xpc_fifo_entry_uv *last;
+	spinlock_t lock;
+	int n_entries;
+};
 
 /*
- * Defines notify entry.
+ * Define a sn2 styled message.
+ *
+ * A user-defined message resides in the payload area. The max size of the
+ * payload is defined by the user via xpc_connect().
+ *
+ * The size of a message entry (within a message queue) must be a 128-byte
+ * cacheline sized multiple in order to facilitate the BTE transfer of messages
+ * from one message queue to another.
+ */
+struct xpc_msg_sn2 {
+	u8 flags;		/* FOR XPC INTERNAL USE ONLY */
+	u8 reserved[7];		/* FOR XPC INTERNAL USE ONLY */
+	s64 number;		/* FOR XPC INTERNAL USE ONLY */
+
+	u64 payload;		/* user defined portion of message */
+};
+
+/* struct xpc_msg_sn2 flags */
+
+#define	XPC_M_SN2_DONE		0x01	/* msg has been received/consumed */
+#define	XPC_M_SN2_READY		0x02	/* msg is ready to be sent */
+#define	XPC_M_SN2_INTERRUPT	0x04	/* send interrupt when msg consumed */
+
+/*
+ * The format of a uv XPC notify_mq GRU message is as follows:
+ *
+ * A user-defined message resides in the payload area. The max size of the
+ * payload is defined by the user via xpc_connect().
+ *
+ * The size of a message (payload and header) sent via the GRU must be either 1
+ * or 2 GRU_CACHE_LINE_BYTES in length.
+ */
+
+struct xpc_notify_mq_msghdr_uv {
+	union {
+		unsigned int gru_msg_hdr;	/* FOR GRU INTERNAL USE ONLY */
+		struct xpc_fifo_entry_uv next;	/* FOR XPC INTERNAL USE ONLY */
+	} u;
+	short partid;		/* FOR XPC INTERNAL USE ONLY */
+	u8 ch_number;		/* FOR XPC INTERNAL USE ONLY */
+	u8 size;		/* FOR XPC INTERNAL USE ONLY */
+	unsigned int msg_slot_number;	/* FOR XPC INTERNAL USE ONLY */
+};
+
+struct xpc_notify_mq_msg_uv {
+	struct xpc_notify_mq_msghdr_uv hdr;
+	unsigned long payload;
+};
+
+/*
+ * Define sn2's notify entry.
  *
  * This is used to notify a message's sender that their message was received
  * and consumed by the intended recipient.
  */
-struct xpc_notify {
+struct xpc_notify_sn2 {
 	u8 type;		/* type of notification */
 
 	/* the following two fields are only used if type == XPC_N_CALL */
@@ -325,9 +374,20 @@ struct xpc_notify {
 	void *key;		/* pointer to user's key */
 };
 
-/* struct xpc_notify type of notification */
+/* struct xpc_notify_sn2 type of notification */
+
+#define	XPC_N_CALL	0x01	/* notify function provided by user */
 
-#define	XPC_N_CALL		0x01	/* notify function provided by user */
+/*
+ * Define uv's version of the notify entry. It additionally is used to allocate
+ * a msg slot on the remote partition into which is copied a sent message.
+ */
+struct xpc_send_msg_slot_uv {
+	struct xpc_fifo_entry_uv next;
+	unsigned int msg_slot_number;
+	xpc_notify_func func;	/* user's notify function */
+	void *key;		/* pointer to user's key */
+};
 
 /*
  * Define the structure that manages all the stuff required by a channel. In
@@ -339,8 +399,12 @@ struct xpc_notify {
  * There is an array of these structures for each remote partition. It is
  * allocated at the time a partition becomes active. The array contains one
  * of these structures for each potential channel connection to that partition.
+ */
+
+/*
+ * The following is sn2 only.
  *
- * Each of these structures manages two message queues (circular buffers).
+ * Each channel structure manages two message queues (circular buffers).
  * They are allocated at the time a channel connection is made. One of
  * these message queues (local_msgqueue) holds the locally created messages
  * that are destined for the remote partition. The other of these message
@@ -407,58 +471,72 @@ struct xpc_notify {
  *	new messages, by the clearing of the message flags of the acknowledged
  *	messages.
  */
+
+struct xpc_channel_sn2 {
+	struct xpc_openclose_args *local_openclose_args; /* args passed on */
+					     /* opening or closing of channel */
+
+	void *local_msgqueue_base;	/* base address of kmalloc'd space */
+	struct xpc_msg_sn2 *local_msgqueue;	/* local message queue */
+	void *remote_msgqueue_base;	/* base address of kmalloc'd space */
+	struct xpc_msg_sn2 *remote_msgqueue; /* cached copy of remote */
+					   /* partition's local message queue */
+	unsigned long remote_msgqueue_pa; /* phys addr of remote partition's */
+					  /* local message queue */
+
+	struct xpc_notify_sn2 *notify_queue;/* notify queue for messages sent */
+
+	/* various flavors of local and remote Get/Put values */
+
+	struct xpc_gp_sn2 *local_GP;	/* local Get/Put values */
+	struct xpc_gp_sn2 remote_GP;	/* remote Get/Put values */
+	struct xpc_gp_sn2 w_local_GP;	/* working local Get/Put values */
+	struct xpc_gp_sn2 w_remote_GP;	/* working remote Get/Put values */
+	s64 next_msg_to_pull;	/* Put value of next msg to pull */
+
+	struct mutex msg_to_pull_mutex;	/* next msg to pull serialization */
+};
+
+struct xpc_channel_uv {
+	unsigned long remote_notify_mq_gpa;	/* gru phys address of remote */
+						/* partition's notify mq */
+
+	struct xpc_send_msg_slot_uv *send_msg_slots;
+	struct xpc_notify_mq_msg_uv *recv_msg_slots;
+
+	struct xpc_fifo_head_uv msg_slot_free_list;
+	struct xpc_fifo_head_uv recv_msg_list;	/* deliverable payloads */
+};
+
 struct xpc_channel {
 	short partid;		/* ID of remote partition connected */
 	spinlock_t lock;	/* lock for updating this structure */
-	u32 flags;		/* general flags */
+	unsigned int flags;	/* general flags */
 
 	enum xp_retval reason;	/* reason why channel is disconnect'g */
 	int reason_line;	/* line# disconnect initiated from */
 
 	u16 number;		/* channel # */
 
-	u16 msg_size;		/* sizeof each msg entry */
+	u16 entry_size;		/* sizeof each msg entry */
 	u16 local_nentries;	/* #of msg entries in local msg queue */
 	u16 remote_nentries;	/* #of msg entries in remote msg queue */
 
-	void *local_msgqueue_base;	/* base address of kmalloc'd space */
-	struct xpc_msg *local_msgqueue;	/* local message queue */
-	void *remote_msgqueue_base;	/* base address of kmalloc'd space */
-	struct xpc_msg *remote_msgqueue; /* cached copy of remote partition's */
-					 /* local message queue */
-	u64 remote_msgqueue_pa;	/* phys addr of remote partition's */
-				/* local message queue */
-
 	atomic_t references;	/* #of external references to queues */
 
 	atomic_t n_on_msg_allocate_wq;	/* #on msg allocation wait queue */
 	wait_queue_head_t msg_allocate_wq;	/* msg allocation wait queue */
 
-	u8 delayed_IPI_flags;	/* IPI flags received, but delayed */
+	u8 delayed_chctl_flags;	/* chctl flags received, but delayed */
 				/* action until channel disconnected */
 
-	/* queue of msg senders who want to be notified when msg received */
-
 	atomic_t n_to_notify;	/* #of msg senders to notify */
-	struct xpc_notify *notify_queue;    /* notify queue for messages sent */
 
 	xpc_channel_func func;	/* user's channel function */
 	void *key;		/* pointer to user's key */
 
-	struct mutex msg_to_pull_mutex;	/* next msg to pull serialization */
 	struct completion wdisconnect_wait;    /* wait for channel disconnect */
 
-	struct xpc_openclose_args *local_openclose_args; /* args passed on */
-					     /* opening or closing of channel */
-
-	/* various flavors of local and remote Get/Put values */
-
-	struct xpc_gp *local_GP;	/* local Get/Put values */
-	struct xpc_gp remote_GP;	/* remote Get/Put values */
-	struct xpc_gp w_local_GP;	/* working local Get/Put values */
-	struct xpc_gp w_remote_GP;	/* working remote Get/Put values */
-	s64 next_msg_to_pull;	/* Put value of next msg to pull */
-
 	/* kthread management related fields */
 
 	atomic_t kthreads_assigned;	/* #of kthreads assigned to channel */
@@ -469,6 +547,11 @@ struct xpc_channel {
 
 	wait_queue_head_t idle_wq;	/* idle kthread wait queue */
 
+	union {
+		struct xpc_channel_sn2 sn2;
+		struct xpc_channel_uv uv;
+	} sn;
+
 } ____cacheline_aligned;
 
 /* struct xpc_channel flags */
@@ -501,33 +584,128 @@ struct xpc_channel {
 #define	XPC_C_WDISCONNECT	0x00040000  /* waiting for channel disconnect */
 
 /*
- * Manages channels on a partition basis. There is one of these structures
+ * The channel control flags (chctl) union consists of a 64-bit variable which
+ * is divided up into eight bytes, ordered from right to left. Byte zero
+ * pertains to channel 0, byte one to channel 1, and so on. Each channel's byte
+ * can have one or more of the chctl flags set in it.
+ */
+
+union xpc_channel_ctl_flags {
+	u64 all_flags;
+	u8 flags[XPC_MAX_NCHANNELS];
+};
+
+/* chctl flags */
+#define	XPC_CHCTL_CLOSEREQUEST	0x01
+#define	XPC_CHCTL_CLOSEREPLY	0x02
+#define	XPC_CHCTL_OPENREQUEST	0x04
+#define	XPC_CHCTL_OPENREPLY	0x08
+#define	XPC_CHCTL_MSGREQUEST	0x10
+
+#define XPC_OPENCLOSE_CHCTL_FLAGS \
+			(XPC_CHCTL_CLOSEREQUEST | XPC_CHCTL_CLOSEREPLY | \
+			 XPC_CHCTL_OPENREQUEST | XPC_CHCTL_OPENREPLY)
+#define XPC_MSG_CHCTL_FLAGS	XPC_CHCTL_MSGREQUEST
+
+static inline int
+xpc_any_openclose_chctl_flags_set(union xpc_channel_ctl_flags *chctl)
+{
+	int ch_number;
+
+	for (ch_number = 0; ch_number < XPC_MAX_NCHANNELS; ch_number++) {
+		if (chctl->flags[ch_number] & XPC_OPENCLOSE_CHCTL_FLAGS)
+			return 1;
+	}
+	return 0;
+}
+
+static inline int
+xpc_any_msg_chctl_flags_set(union xpc_channel_ctl_flags *chctl)
+{
+	int ch_number;
+
+	for (ch_number = 0; ch_number < XPC_MAX_NCHANNELS; ch_number++) {
+		if (chctl->flags[ch_number] & XPC_MSG_CHCTL_FLAGS)
+			return 1;
+	}
+	return 0;
+}
+
+/*
+ * Manage channels on a partition basis. There is one of these structures
  * for each partition (a partition will never utilize the structure that
  * represents itself).
  */
+
+struct xpc_partition_sn2 {
+	unsigned long remote_amos_page_pa; /* paddr of partition's amos page */
+	int activate_IRQ_nasid;	/* active partition's act/deact nasid */
+	int activate_IRQ_phys_cpuid;	/* active part's act/deact phys cpuid */
+
+	unsigned long remote_vars_pa;	/* phys addr of partition's vars */
+	unsigned long remote_vars_part_pa; /* paddr of partition's vars part */
+	u8 remote_vars_version;	/* version# of partition's vars */
+
+	void *local_GPs_base;	/* base address of kmalloc'd space */
+	struct xpc_gp_sn2 *local_GPs;	/* local Get/Put values */
+	void *remote_GPs_base;	/* base address of kmalloc'd space */
+	struct xpc_gp_sn2 *remote_GPs;	/* copy of remote partition's local */
+					/* Get/Put values */
+	unsigned long remote_GPs_pa; /* phys addr of remote partition's local */
+				     /* Get/Put values */
+
+	void *local_openclose_args_base;   /* base address of kmalloc'd space */
+	struct xpc_openclose_args *local_openclose_args;      /* local's args */
+	unsigned long remote_openclose_args_pa;	/* phys addr of remote's args */
+
+	int notify_IRQ_nasid;	/* nasid of where to send notify IRQs */
+	int notify_IRQ_phys_cpuid;	/* CPUID of where to send notify IRQs */
+	char notify_IRQ_owner[8];	/* notify IRQ's owner's name */
+
+	struct amo *remote_chctl_amo_va; /* addr of remote chctl flags' amo */
+	struct amo *local_chctl_amo_va;	/* address of chctl flags' amo */
+
+	struct timer_list dropped_notify_IRQ_timer;	/* dropped IRQ timer */
+};
+
+struct xpc_partition_uv {
+	unsigned long remote_activate_mq_gpa;	/* gru phys address of remote */
+						/* partition's activate mq */
+	spinlock_t flags_lock;	/* protect updating of flags */
+	unsigned int flags;	/* general flags */
+	u8 remote_act_state;	/* remote partition's act_state */
+	u8 act_state_req;	/* act_state request from remote partition */
+	enum xp_retval reason;	/* reason for deactivate act_state request */
+	u64 heartbeat;		/* incremented by remote partition */
+};
+
+/* struct xpc_partition_uv flags */
+
+#define XPC_P_HEARTBEAT_OFFLINE_UV	0x00000001
+#define XPC_P_ENGAGED_UV		0x00000002
+
+/* struct xpc_partition_uv act_state change requests */
+
+#define XPC_P_ASR_ACTIVATE_UV		0x01
+#define XPC_P_ASR_REACTIVATE_UV		0x02
+#define XPC_P_ASR_DEACTIVATE_UV		0x03
+
 struct xpc_partition {
 
 	/* XPC HB infrastructure */
 
 	u8 remote_rp_version;	/* version# of partition's rsvd pg */
-	struct timespec remote_rp_stamp; /* time when rsvd pg was initialized */
-	u64 remote_rp_pa;	/* phys addr of partition's rsvd pg */
-	u64 remote_vars_pa;	/* phys addr of partition's vars */
-	u64 remote_vars_part_pa;	/* phys addr of partition's vars part */
+	unsigned long remote_rp_ts_jiffies; /* timestamp when rsvd pg setup */
+	unsigned long remote_rp_pa;	/* phys addr of partition's rsvd pg */
 	u64 last_heartbeat;	/* HB at last read */
-	u64 remote_amos_page_pa;	/* phys addr of partition's amos page */
-	int remote_act_nasid;	/* active part's act/deact nasid */
-	int remote_act_phys_cpuid;	/* active part's act/deact phys cpuid */
-	u32 act_IRQ_rcvd;	/* IRQs since activation */
+	u32 activate_IRQ_rcvd;	/* IRQs since activation */
 	spinlock_t act_lock;	/* protect updating of act_state */
 	u8 act_state;		/* from XPC HB viewpoint */
-	u8 remote_vars_version;	/* version# of partition's vars */
 	enum xp_retval reason;	/* reason partition is deactivating */
 	int reason_line;	/* line# deactivation initiated from */
-	int reactivate_nasid;	/* nasid in partition to reactivate */
 
-	unsigned long disengage_request_timeout;	/* timeout in jiffies */
-	struct timer_list disengage_request_timer;
+	unsigned long disengage_timeout;	/* timeout in jiffies */
+	struct timer_list disengage_timer;
 
 	/* XPC infrastructure referencing and teardown control */
 
@@ -535,85 +713,63 @@ struct xpc_partition {
 	wait_queue_head_t teardown_wq;	/* kthread waiting to teardown infra */
 	atomic_t references;	/* #of references to infrastructure */
 
-	/*
-	 * NONE OF THE PRECEDING FIELDS OF THIS STRUCTURE WILL BE CLEARED WHEN
-	 * XPC SETS UP THE NECESSARY INFRASTRUCTURE TO SUPPORT CROSS PARTITION
-	 * COMMUNICATION. ALL OF THE FOLLOWING FIELDS WILL BE CLEARED. (THE
-	 * 'nchannels' FIELD MUST BE THE FIRST OF THE FIELDS TO BE CLEARED.)
-	 */
-
 	u8 nchannels;		/* #of defined channels supported */
 	atomic_t nchannels_active;  /* #of channels that are not DISCONNECTED */
 	atomic_t nchannels_engaged;  /* #of channels engaged with remote part */
 	struct xpc_channel *channels;	/* array of channel structures */
 
-	void *local_GPs_base;	/* base address of kmalloc'd space */
-	struct xpc_gp *local_GPs;	/* local Get/Put values */
-	void *remote_GPs_base;	/* base address of kmalloc'd space */
-	struct xpc_gp *remote_GPs;	/* copy of remote partition's local */
-					/* Get/Put values */
-	u64 remote_GPs_pa;	/* phys address of remote partition's local */
-				/* Get/Put values */
+	/* fields used for managing channel avialability and activity */
 
-	/* fields used to pass args when opening or closing a channel */
+	union xpc_channel_ctl_flags chctl; /* chctl flags yet to be processed */
+	spinlock_t chctl_lock;	/* chctl flags lock */
 
-	void *local_openclose_args_base;   /* base address of kmalloc'd space */
-	struct xpc_openclose_args *local_openclose_args;      /* local's args */
 	void *remote_openclose_args_base;  /* base address of kmalloc'd space */
 	struct xpc_openclose_args *remote_openclose_args; /* copy of remote's */
 							  /* args */
-	u64 remote_openclose_args_pa;	/* phys addr of remote's args */
-
-	/* IPI sending, receiving and handling related fields */
-
-	int remote_IPI_nasid;	/* nasid of where to send IPIs */
-	int remote_IPI_phys_cpuid;	/* phys CPU ID of where to send IPIs */
-	AMO_t *remote_IPI_amo_va;    /* address of remote IPI AMO_t structure */
-
-	AMO_t *local_IPI_amo_va;	/* address of IPI AMO_t structure */
-	u64 local_IPI_amo;	/* IPI amo flags yet to be handled */
-	char IPI_owner[8];	/* IPI owner's name */
-	struct timer_list dropped_IPI_timer;	/* dropped IPI timer */
-
-	spinlock_t IPI_lock;	/* IPI handler lock */
 
 	/* channel manager related fields */
 
 	atomic_t channel_mgr_requests;	/* #of requests to activate chan mgr */
 	wait_queue_head_t channel_mgr_wq;	/* channel mgr's wait queue */
 
+	union {
+		struct xpc_partition_sn2 sn2;
+		struct xpc_partition_uv uv;
+	} sn;
+
 } ____cacheline_aligned;
 
 /* struct xpc_partition act_state values (for XPC HB) */
 
-#define	XPC_P_INACTIVE		0x00	/* partition is not active */
-#define XPC_P_ACTIVATION_REQ	0x01	/* created thread to activate */
-#define XPC_P_ACTIVATING	0x02	/* activation thread started */
-#define XPC_P_ACTIVE		0x03	/* xpc_partition_up() was called */
-#define XPC_P_DEACTIVATING	0x04	/* partition deactivation initiated */
+#define	XPC_P_AS_INACTIVE	0x00	/* partition is not active */
+#define XPC_P_AS_ACTIVATION_REQ	0x01	/* created thread to activate */
+#define XPC_P_AS_ACTIVATING	0x02	/* activation thread started */
+#define XPC_P_AS_ACTIVE		0x03	/* xpc_partition_up() was called */
+#define XPC_P_AS_DEACTIVATING	0x04	/* partition deactivation initiated */
 
 #define XPC_DEACTIVATE_PARTITION(_p, _reason) \
 			xpc_deactivate_partition(__LINE__, (_p), (_reason))
 
 /* struct xpc_partition setup_state values */
 
-#define XPC_P_UNSET		0x00	/* infrastructure was never setup */
-#define XPC_P_SETUP		0x01	/* infrastructure is setup */
-#define XPC_P_WTEARDOWN		0x02	/* waiting to teardown infrastructure */
-#define XPC_P_TORNDOWN		0x03	/* infrastructure is torndown */
+#define XPC_P_SS_UNSET		0x00	/* infrastructure was never setup */
+#define XPC_P_SS_SETUP		0x01	/* infrastructure is setup */
+#define XPC_P_SS_WTEARDOWN	0x02	/* waiting to teardown infrastructure */
+#define XPC_P_SS_TORNDOWN	0x03	/* infrastructure is torndown */
 
 /*
- * struct xpc_partition IPI_timer #of seconds to wait before checking for
- * dropped IPIs. These occur whenever an IPI amo write doesn't complete until
- * after the IPI was received.
+ * struct xpc_partition_sn2's dropped notify IRQ timer is set to wait the
+ * following interval #of seconds before checking for dropped notify IRQs.
+ * These can occur whenever an IRQ's associated amo write doesn't complete
+ * until after the IRQ was received.
  */
-#define XPC_P_DROPPED_IPI_WAIT	(0.25 * HZ)
+#define XPC_DROPPED_NOTIFY_IRQ_WAIT_INTERVAL	(0.25 * HZ)
 
 /* number of seconds to wait for other partitions to disengage */
-#define XPC_DISENGAGE_REQUEST_DEFAULT_TIMELIMIT	90
+#define XPC_DISENGAGE_DEFAULT_TIMELIMIT		90
 
-/* interval in seconds to print 'waiting disengagement' messages */
-#define XPC_DISENGAGE_PRINTMSG_INTERVAL		10
+/* interval in seconds to print 'waiting deactivation' messages */
+#define XPC_DEACTIVATE_PRINTMSG_INTERVAL	10
 
 #define XPC_PARTID(_p)	((short)((_p) - &xpc_partitions[0]))
 
@@ -623,33 +779,92 @@ extern struct xpc_registration xpc_registrations[];
 /* found in xpc_main.c */
 extern struct device *xpc_part;
 extern struct device *xpc_chan;
-extern int xpc_disengage_request_timelimit;
-extern int xpc_disengage_request_timedout;
-extern irqreturn_t xpc_notify_IRQ_handler(int, void *);
-extern void xpc_dropped_IPI_check(struct xpc_partition *);
+extern int xpc_disengage_timelimit;
+extern int xpc_disengage_timedout;
+extern int xpc_activate_IRQ_rcvd;
+extern spinlock_t xpc_activate_IRQ_rcvd_lock;
+extern wait_queue_head_t xpc_activate_IRQ_wq;
+extern void *xpc_heartbeating_to_mask;
+extern void *xpc_kzalloc_cacheline_aligned(size_t, gfp_t, void **);
 extern void xpc_activate_partition(struct xpc_partition *);
 extern void xpc_activate_kthreads(struct xpc_channel *, int);
 extern void xpc_create_kthreads(struct xpc_channel *, int, int);
 extern void xpc_disconnect_wait(int);
+extern int (*xpc_setup_partitions_sn) (void);
+extern enum xp_retval (*xpc_get_partition_rsvd_page_pa) (void *, u64 *,
+							 unsigned long *,
+							 size_t *);
+extern int (*xpc_setup_rsvd_page_sn) (struct xpc_rsvd_page *);
+extern void (*xpc_heartbeat_init) (void);
+extern void (*xpc_heartbeat_exit) (void);
+extern void (*xpc_increment_heartbeat) (void);
+extern void (*xpc_offline_heartbeat) (void);
+extern void (*xpc_online_heartbeat) (void);
+extern enum xp_retval (*xpc_get_remote_heartbeat) (struct xpc_partition *);
+extern enum xp_retval (*xpc_make_first_contact) (struct xpc_partition *);
+extern u64 (*xpc_get_chctl_all_flags) (struct xpc_partition *);
+extern enum xp_retval (*xpc_setup_msg_structures) (struct xpc_channel *);
+extern void (*xpc_teardown_msg_structures) (struct xpc_channel *);
+extern void (*xpc_notify_senders_of_disconnect) (struct xpc_channel *);
+extern void (*xpc_process_msg_chctl_flags) (struct xpc_partition *, int);
+extern int (*xpc_n_of_deliverable_payloads) (struct xpc_channel *);
+extern void *(*xpc_get_deliverable_payload) (struct xpc_channel *);
+extern void (*xpc_request_partition_activation) (struct xpc_rsvd_page *,
+						 unsigned long, int);
+extern void (*xpc_request_partition_reactivation) (struct xpc_partition *);
+extern void (*xpc_request_partition_deactivation) (struct xpc_partition *);
+extern void (*xpc_cancel_partition_deactivation_request) (
+							struct xpc_partition *);
+extern void (*xpc_process_activate_IRQ_rcvd) (void);
+extern enum xp_retval (*xpc_setup_ch_structures_sn) (struct xpc_partition *);
+extern void (*xpc_teardown_ch_structures_sn) (struct xpc_partition *);
+
+extern void (*xpc_indicate_partition_engaged) (struct xpc_partition *);
+extern int (*xpc_partition_engaged) (short);
+extern int (*xpc_any_partition_engaged) (void);
+extern void (*xpc_indicate_partition_disengaged) (struct xpc_partition *);
+extern void (*xpc_assume_partition_disengaged) (short);
+
+extern void (*xpc_send_chctl_closerequest) (struct xpc_channel *,
+					    unsigned long *);
+extern void (*xpc_send_chctl_closereply) (struct xpc_channel *,
+					  unsigned long *);
+extern void (*xpc_send_chctl_openrequest) (struct xpc_channel *,
+					   unsigned long *);
+extern void (*xpc_send_chctl_openreply) (struct xpc_channel *, unsigned long *);
+
+extern void (*xpc_save_remote_msgqueue_pa) (struct xpc_channel *,
+					    unsigned long);
+
+extern enum xp_retval (*xpc_send_payload) (struct xpc_channel *, u32, void *,
+					   u16, u8, xpc_notify_func, void *);
+extern void (*xpc_received_payload) (struct xpc_channel *, void *);
+
+/* found in xpc_sn2.c */
+extern int xpc_init_sn2(void);
+extern void xpc_exit_sn2(void);
+
+/* found in xpc_uv.c */
+extern int xpc_init_uv(void);
+extern void xpc_exit_uv(void);
 
 /* found in xpc_partition.c */
 extern int xpc_exiting;
-extern struct xpc_vars *xpc_vars;
+extern int xpc_nasid_mask_nlongs;
 extern struct xpc_rsvd_page *xpc_rsvd_page;
-extern struct xpc_vars_part *xpc_vars_part;
-extern struct xpc_partition xpc_partitions[XP_MAX_PARTITIONS + 1];
-extern char *xpc_remote_copy_buffer;
-extern void *xpc_remote_copy_buffer_base;
+extern unsigned long *xpc_mach_nasids;
+extern struct xpc_partition *xpc_partitions;
 extern void *xpc_kmalloc_cacheline_aligned(size_t, gfp_t, void **);
-extern struct xpc_rsvd_page *xpc_rsvd_page_init(void);
-extern void xpc_allow_IPI_ops(void);
-extern void xpc_restrict_IPI_ops(void);
-extern int xpc_identify_act_IRQ_sender(void);
+extern int xpc_setup_rsvd_page(void);
+extern void xpc_teardown_rsvd_page(void);
+extern int xpc_identify_activate_IRQ_sender(void);
 extern int xpc_partition_disengaged(struct xpc_partition *);
 extern enum xp_retval xpc_mark_partition_active(struct xpc_partition *);
 extern void xpc_mark_partition_inactive(struct xpc_partition *);
 extern void xpc_discovery(void);
-extern void xpc_check_remote_hb(void);
+extern enum xp_retval xpc_get_remote_rp(int, unsigned long *,
+					struct xpc_rsvd_page *,
+					unsigned long *);
 extern void xpc_deactivate_partition(const int, struct xpc_partition *,
 				     enum xp_retval);
 extern enum xp_retval xpc_initiate_partid_to_nasids(short, void *);
@@ -657,21 +872,52 @@ extern enum xp_retval xpc_initiate_partid_to_nasids(short, void *);
 /* found in xpc_channel.c */
 extern void xpc_initiate_connect(int);
 extern void xpc_initiate_disconnect(int);
-extern enum xp_retval xpc_initiate_allocate(short, int, u32, void **);
-extern enum xp_retval xpc_initiate_send(short, int, void *);
-extern enum xp_retval xpc_initiate_send_notify(short, int, void *,
+extern enum xp_retval xpc_allocate_msg_wait(struct xpc_channel *);
+extern enum xp_retval xpc_initiate_send(short, int, u32, void *, u16);
+extern enum xp_retval xpc_initiate_send_notify(short, int, u32, void *, u16,
 					       xpc_notify_func, void *);
 extern void xpc_initiate_received(short, int, void *);
-extern enum xp_retval xpc_setup_infrastructure(struct xpc_partition *);
-extern enum xp_retval xpc_pull_remote_vars_part(struct xpc_partition *);
-extern void xpc_process_channel_activity(struct xpc_partition *);
+extern void xpc_process_sent_chctl_flags(struct xpc_partition *);
 extern void xpc_connected_callout(struct xpc_channel *);
-extern void xpc_deliver_msg(struct xpc_channel *);
+extern void xpc_deliver_payload(struct xpc_channel *);
 extern void xpc_disconnect_channel(const int, struct xpc_channel *,
 				   enum xp_retval, unsigned long *);
 extern void xpc_disconnect_callout(struct xpc_channel *, enum xp_retval);
 extern void xpc_partition_going_down(struct xpc_partition *, enum xp_retval);
-extern void xpc_teardown_infrastructure(struct xpc_partition *);
+
+static inline int
+xpc_hb_allowed(short partid, void *heartbeating_to_mask)
+{
+	return test_bit(partid, heartbeating_to_mask);
+}
+
+static inline int
+xpc_any_hbs_allowed(void)
+{
+	DBUG_ON(xpc_heartbeating_to_mask == NULL);
+	return !bitmap_empty(xpc_heartbeating_to_mask, xp_max_npartitions);
+}
+
+static inline void
+xpc_allow_hb(short partid)
+{
+	DBUG_ON(xpc_heartbeating_to_mask == NULL);
+	set_bit(partid, xpc_heartbeating_to_mask);
+}
+
+static inline void
+xpc_disallow_hb(short partid)
+{
+	DBUG_ON(xpc_heartbeating_to_mask == NULL);
+	clear_bit(partid, xpc_heartbeating_to_mask);
+}
+
+static inline void
+xpc_disallow_all_hbs(void)
+{
+	DBUG_ON(xpc_heartbeating_to_mask == NULL);
+	bitmap_zero(xpc_heartbeating_to_mask, xp_max_npartitions);
+}
 
 static inline void
 xpc_wakeup_channel_mgr(struct xpc_partition *part)
@@ -713,7 +959,7 @@ xpc_part_deref(struct xpc_partition *part)
 	s32 refs = atomic_dec_return(&part->references);
 
 	DBUG_ON(refs < 0);
-	if (refs == 0 && part->setup_state == XPC_P_WTEARDOWN)
+	if (refs == 0 && part->setup_state == XPC_P_SS_WTEARDOWN)
 		wake_up(&part->teardown_wq);
 }
 
@@ -723,7 +969,7 @@ xpc_part_ref(struct xpc_partition *part)
 	int setup;
 
 	atomic_inc(&part->references);
-	setup = (part->setup_state == XPC_P_SETUP);
+	setup = (part->setup_state == XPC_P_SS_SETUP);
 	if (!setup)
 		xpc_part_deref(part);
 
@@ -741,416 +987,4 @@ xpc_part_ref(struct xpc_partition *part)
 		(_p)->reason_line = _line; \
 	}
 
-/*
- * This next set of inlines are used to keep track of when a partition is
- * potentially engaged in accessing memory belonging to another partition.
- */
-
-static inline void
-xpc_mark_partition_engaged(struct xpc_partition *part)
-{
-	unsigned long irq_flags;
-	AMO_t *amo = (AMO_t *)__va(part->remote_amos_page_pa +
-				   (XPC_ENGAGED_PARTITIONS_AMO *
-				    sizeof(AMO_t)));
-
-	local_irq_save(irq_flags);
-
-	/* set bit corresponding to our partid in remote partition's AMO */
-	FETCHOP_STORE_OP(TO_AMO((u64)&amo->variable), FETCHOP_OR,
-			 (1UL << sn_partition_id));
-	/*
-	 * We must always use the nofault function regardless of whether we
-	 * are on a Shub 1.1 system or a Shub 1.2 slice 0xc processor. If we
-	 * didn't, we'd never know that the other partition is down and would
-	 * keep sending IPIs and AMOs to it until the heartbeat times out.
-	 */
-	(void)xp_nofault_PIOR((u64 *)GLOBAL_MMR_ADDR(NASID_GET(&amo->
-							       variable),
-						     xp_nofault_PIOR_target));
-
-	local_irq_restore(irq_flags);
-}
-
-static inline void
-xpc_mark_partition_disengaged(struct xpc_partition *part)
-{
-	unsigned long irq_flags;
-	AMO_t *amo = (AMO_t *)__va(part->remote_amos_page_pa +
-				   (XPC_ENGAGED_PARTITIONS_AMO *
-				    sizeof(AMO_t)));
-
-	local_irq_save(irq_flags);
-
-	/* clear bit corresponding to our partid in remote partition's AMO */
-	FETCHOP_STORE_OP(TO_AMO((u64)&amo->variable), FETCHOP_AND,
-			 ~(1UL << sn_partition_id));
-	/*
-	 * We must always use the nofault function regardless of whether we
-	 * are on a Shub 1.1 system or a Shub 1.2 slice 0xc processor. If we
-	 * didn't, we'd never know that the other partition is down and would
-	 * keep sending IPIs and AMOs to it until the heartbeat times out.
-	 */
-	(void)xp_nofault_PIOR((u64 *)GLOBAL_MMR_ADDR(NASID_GET(&amo->
-							       variable),
-						     xp_nofault_PIOR_target));
-
-	local_irq_restore(irq_flags);
-}
-
-static inline void
-xpc_request_partition_disengage(struct xpc_partition *part)
-{
-	unsigned long irq_flags;
-	AMO_t *amo = (AMO_t *)__va(part->remote_amos_page_pa +
-				   (XPC_DISENGAGE_REQUEST_AMO * sizeof(AMO_t)));
-
-	local_irq_save(irq_flags);
-
-	/* set bit corresponding to our partid in remote partition's AMO */
-	FETCHOP_STORE_OP(TO_AMO((u64)&amo->variable), FETCHOP_OR,
-			 (1UL << sn_partition_id));
-	/*
-	 * We must always use the nofault function regardless of whether we
-	 * are on a Shub 1.1 system or a Shub 1.2 slice 0xc processor. If we
-	 * didn't, we'd never know that the other partition is down and would
-	 * keep sending IPIs and AMOs to it until the heartbeat times out.
-	 */
-	(void)xp_nofault_PIOR((u64 *)GLOBAL_MMR_ADDR(NASID_GET(&amo->
-							       variable),
-						     xp_nofault_PIOR_target));
-
-	local_irq_restore(irq_flags);
-}
-
-static inline void
-xpc_cancel_partition_disengage_request(struct xpc_partition *part)
-{
-	unsigned long irq_flags;
-	AMO_t *amo = (AMO_t *)__va(part->remote_amos_page_pa +
-				   (XPC_DISENGAGE_REQUEST_AMO * sizeof(AMO_t)));
-
-	local_irq_save(irq_flags);
-
-	/* clear bit corresponding to our partid in remote partition's AMO */
-	FETCHOP_STORE_OP(TO_AMO((u64)&amo->variable), FETCHOP_AND,
-			 ~(1UL << sn_partition_id));
-	/*
-	 * We must always use the nofault function regardless of whether we
-	 * are on a Shub 1.1 system or a Shub 1.2 slice 0xc processor. If we
-	 * didn't, we'd never know that the other partition is down and would
-	 * keep sending IPIs and AMOs to it until the heartbeat times out.
-	 */
-	(void)xp_nofault_PIOR((u64 *)GLOBAL_MMR_ADDR(NASID_GET(&amo->
-							       variable),
-						     xp_nofault_PIOR_target));
-
-	local_irq_restore(irq_flags);
-}
-
-static inline u64
-xpc_partition_engaged(u64 partid_mask)
-{
-	AMO_t *amo = xpc_vars->amos_page + XPC_ENGAGED_PARTITIONS_AMO;
-
-	/* return our partition's AMO variable ANDed with partid_mask */
-	return (FETCHOP_LOAD_OP(TO_AMO((u64)&amo->variable), FETCHOP_LOAD) &
-		partid_mask);
-}
-
-static inline u64
-xpc_partition_disengage_requested(u64 partid_mask)
-{
-	AMO_t *amo = xpc_vars->amos_page + XPC_DISENGAGE_REQUEST_AMO;
-
-	/* return our partition's AMO variable ANDed with partid_mask */
-	return (FETCHOP_LOAD_OP(TO_AMO((u64)&amo->variable), FETCHOP_LOAD) &
-		partid_mask);
-}
-
-static inline void
-xpc_clear_partition_engaged(u64 partid_mask)
-{
-	AMO_t *amo = xpc_vars->amos_page + XPC_ENGAGED_PARTITIONS_AMO;
-
-	/* clear bit(s) based on partid_mask in our partition's AMO */
-	FETCHOP_STORE_OP(TO_AMO((u64)&amo->variable), FETCHOP_AND,
-			 ~partid_mask);
-}
-
-static inline void
-xpc_clear_partition_disengage_request(u64 partid_mask)
-{
-	AMO_t *amo = xpc_vars->amos_page + XPC_DISENGAGE_REQUEST_AMO;
-
-	/* clear bit(s) based on partid_mask in our partition's AMO */
-	FETCHOP_STORE_OP(TO_AMO((u64)&amo->variable), FETCHOP_AND,
-			 ~partid_mask);
-}
-
-/*
- * The following set of macros and inlines are used for the sending and
- * receiving of IPIs (also known as IRQs). There are two flavors of IPIs,
- * one that is associated with partition activity (SGI_XPC_ACTIVATE) and
- * the other that is associated with channel activity (SGI_XPC_NOTIFY).
- */
-
-static inline u64
-xpc_IPI_receive(AMO_t *amo)
-{
-	return FETCHOP_LOAD_OP(TO_AMO((u64)&amo->variable), FETCHOP_CLEAR);
-}
-
-static inline enum xp_retval
-xpc_IPI_send(AMO_t *amo, u64 flag, int nasid, int phys_cpuid, int vector)
-{
-	int ret = 0;
-	unsigned long irq_flags;
-
-	local_irq_save(irq_flags);
-
-	FETCHOP_STORE_OP(TO_AMO((u64)&amo->variable), FETCHOP_OR, flag);
-	sn_send_IPI_phys(nasid, phys_cpuid, vector, 0);
-
-	/*
-	 * We must always use the nofault function regardless of whether we
-	 * are on a Shub 1.1 system or a Shub 1.2 slice 0xc processor. If we
-	 * didn't, we'd never know that the other partition is down and would
-	 * keep sending IPIs and AMOs to it until the heartbeat times out.
-	 */
-	ret = xp_nofault_PIOR((u64 *)GLOBAL_MMR_ADDR(NASID_GET(&amo->variable),
-						     xp_nofault_PIOR_target));
-
-	local_irq_restore(irq_flags);
-
-	return ((ret == 0) ? xpSuccess : xpPioReadError);
-}
-
-/*
- * IPIs associated with SGI_XPC_ACTIVATE IRQ.
- */
-
-/*
- * Flag the appropriate AMO variable and send an IPI to the specified node.
- */
-static inline void
-xpc_activate_IRQ_send(u64 amos_page_pa, int from_nasid, int to_nasid,
-		      int to_phys_cpuid)
-{
-	int w_index = XPC_NASID_W_INDEX(from_nasid);
-	int b_index = XPC_NASID_B_INDEX(from_nasid);
-	AMO_t *amos = (AMO_t *)__va(amos_page_pa +
-				    (XPC_ACTIVATE_IRQ_AMOS * sizeof(AMO_t)));
-
-	(void)xpc_IPI_send(&amos[w_index], (1UL << b_index), to_nasid,
-			   to_phys_cpuid, SGI_XPC_ACTIVATE);
-}
-
-static inline void
-xpc_IPI_send_activate(struct xpc_vars *vars)
-{
-	xpc_activate_IRQ_send(vars->amos_page_pa, cnodeid_to_nasid(0),
-			      vars->act_nasid, vars->act_phys_cpuid);
-}
-
-static inline void
-xpc_IPI_send_activated(struct xpc_partition *part)
-{
-	xpc_activate_IRQ_send(part->remote_amos_page_pa, cnodeid_to_nasid(0),
-			      part->remote_act_nasid,
-			      part->remote_act_phys_cpuid);
-}
-
-static inline void
-xpc_IPI_send_reactivate(struct xpc_partition *part)
-{
-	xpc_activate_IRQ_send(xpc_vars->amos_page_pa, part->reactivate_nasid,
-			      xpc_vars->act_nasid, xpc_vars->act_phys_cpuid);
-}
-
-static inline void
-xpc_IPI_send_disengage(struct xpc_partition *part)
-{
-	xpc_activate_IRQ_send(part->remote_amos_page_pa, cnodeid_to_nasid(0),
-			      part->remote_act_nasid,
-			      part->remote_act_phys_cpuid);
-}
-
-/*
- * IPIs associated with SGI_XPC_NOTIFY IRQ.
- */
-
-/*
- * Send an IPI to the remote partition that is associated with the
- * specified channel.
- */
-#define XPC_NOTIFY_IRQ_SEND(_ch, _ipi_f, _irq_f) \
-		xpc_notify_IRQ_send(_ch, _ipi_f, #_ipi_f, _irq_f)
-
-static inline void
-xpc_notify_IRQ_send(struct xpc_channel *ch, u8 ipi_flag, char *ipi_flag_string,
-		    unsigned long *irq_flags)
-{
-	struct xpc_partition *part = &xpc_partitions[ch->partid];
-	enum xp_retval ret;
-
-	if (likely(part->act_state != XPC_P_DEACTIVATING)) {
-		ret = xpc_IPI_send(part->remote_IPI_amo_va,
-				   (u64)ipi_flag << (ch->number * 8),
-				   part->remote_IPI_nasid,
-				   part->remote_IPI_phys_cpuid, SGI_XPC_NOTIFY);
-		dev_dbg(xpc_chan, "%s sent to partid=%d, channel=%d, ret=%d\n",
-			ipi_flag_string, ch->partid, ch->number, ret);
-		if (unlikely(ret != xpSuccess)) {
-			if (irq_flags != NULL)
-				spin_unlock_irqrestore(&ch->lock, *irq_flags);
-			XPC_DEACTIVATE_PARTITION(part, ret);
-			if (irq_flags != NULL)
-				spin_lock_irqsave(&ch->lock, *irq_flags);
-		}
-	}
-}
-
-/*
- * Make it look like the remote partition, which is associated with the
- * specified channel, sent us an IPI. This faked IPI will be handled
- * by xpc_dropped_IPI_check().
- */
-#define XPC_NOTIFY_IRQ_SEND_LOCAL(_ch, _ipi_f) \
-		xpc_notify_IRQ_send_local(_ch, _ipi_f, #_ipi_f)
-
-static inline void
-xpc_notify_IRQ_send_local(struct xpc_channel *ch, u8 ipi_flag,
-			  char *ipi_flag_string)
-{
-	struct xpc_partition *part = &xpc_partitions[ch->partid];
-
-	FETCHOP_STORE_OP(TO_AMO((u64)&part->local_IPI_amo_va->variable),
-			 FETCHOP_OR, ((u64)ipi_flag << (ch->number * 8)));
-	dev_dbg(xpc_chan, "%s sent local from partid=%d, channel=%d\n",
-		ipi_flag_string, ch->partid, ch->number);
-}
-
-/*
- * The sending and receiving of IPIs includes the setting of an AMO variable
- * to indicate the reason the IPI was sent. The 64-bit variable is divided
- * up into eight bytes, ordered from right to left. Byte zero pertains to
- * channel 0, byte one to channel 1, and so on. Each byte is described by
- * the following IPI flags.
- */
-
-#define	XPC_IPI_CLOSEREQUEST	0x01
-#define	XPC_IPI_CLOSEREPLY	0x02
-#define	XPC_IPI_OPENREQUEST	0x04
-#define	XPC_IPI_OPENREPLY	0x08
-#define	XPC_IPI_MSGREQUEST	0x10
-
-/* given an AMO variable and a channel#, get its associated IPI flags */
-#define XPC_GET_IPI_FLAGS(_amo, _c)	((u8) (((_amo) >> ((_c) * 8)) & 0xff))
-#define XPC_SET_IPI_FLAGS(_amo, _c, _f)	(_amo) |= ((u64) (_f) << ((_c) * 8))
-
-#define	XPC_ANY_OPENCLOSE_IPI_FLAGS_SET(_amo) ((_amo) & 0x0f0f0f0f0f0f0f0fUL)
-#define XPC_ANY_MSG_IPI_FLAGS_SET(_amo)       ((_amo) & 0x1010101010101010UL)
-
-static inline void
-xpc_IPI_send_closerequest(struct xpc_channel *ch, unsigned long *irq_flags)
-{
-	struct xpc_openclose_args *args = ch->local_openclose_args;
-
-	args->reason = ch->reason;
-
-	XPC_NOTIFY_IRQ_SEND(ch, XPC_IPI_CLOSEREQUEST, irq_flags);
-}
-
-static inline void
-xpc_IPI_send_closereply(struct xpc_channel *ch, unsigned long *irq_flags)
-{
-	XPC_NOTIFY_IRQ_SEND(ch, XPC_IPI_CLOSEREPLY, irq_flags);
-}
-
-static inline void
-xpc_IPI_send_openrequest(struct xpc_channel *ch, unsigned long *irq_flags)
-{
-	struct xpc_openclose_args *args = ch->local_openclose_args;
-
-	args->msg_size = ch->msg_size;
-	args->local_nentries = ch->local_nentries;
-
-	XPC_NOTIFY_IRQ_SEND(ch, XPC_IPI_OPENREQUEST, irq_flags);
-}
-
-static inline void
-xpc_IPI_send_openreply(struct xpc_channel *ch, unsigned long *irq_flags)
-{
-	struct xpc_openclose_args *args = ch->local_openclose_args;
-
-	args->remote_nentries = ch->remote_nentries;
-	args->local_nentries = ch->local_nentries;
-	args->local_msgqueue_pa = __pa(ch->local_msgqueue);
-
-	XPC_NOTIFY_IRQ_SEND(ch, XPC_IPI_OPENREPLY, irq_flags);
-}
-
-static inline void
-xpc_IPI_send_msgrequest(struct xpc_channel *ch)
-{
-	XPC_NOTIFY_IRQ_SEND(ch, XPC_IPI_MSGREQUEST, NULL);
-}
-
-static inline void
-xpc_IPI_send_local_msgrequest(struct xpc_channel *ch)
-{
-	XPC_NOTIFY_IRQ_SEND_LOCAL(ch, XPC_IPI_MSGREQUEST);
-}
-
-/*
- * Memory for XPC's AMO variables is allocated by the MSPEC driver. These
- * pages are located in the lowest granule. The lowest granule uses 4k pages
- * for cached references and an alternate TLB handler to never provide a
- * cacheable mapping for the entire region. This will prevent speculative
- * reading of cached copies of our lines from being issued which will cause
- * a PI FSB Protocol error to be generated by the SHUB. For XPC, we need 64
- * AMO variables (based on XP_MAX_PARTITIONS) for message notification and an
- * additional 128 AMO variables (based on XP_NASID_MASK_WORDS) for partition
- * activation and 2 AMO variables for partition deactivation.
- */
-static inline AMO_t *
-xpc_IPI_init(int index)
-{
-	AMO_t *amo = xpc_vars->amos_page + index;
-
-	(void)xpc_IPI_receive(amo);	/* clear AMO variable */
-	return amo;
-}
-
-static inline enum xp_retval
-xpc_map_bte_errors(bte_result_t error)
-{
-	return ((error == BTE_SUCCESS) ? xpSuccess : xpBteCopyError);
-}
-
-/*
- * Check to see if there is any channel activity to/from the specified
- * partition.
- */
-static inline void
-xpc_check_for_channel_activity(struct xpc_partition *part)
-{
-	u64 IPI_amo;
-	unsigned long irq_flags;
-
-	IPI_amo = xpc_IPI_receive(part->local_IPI_amo_va);
-	if (IPI_amo == 0)
-		return;
-
-	spin_lock_irqsave(&part->IPI_lock, irq_flags);
-	part->local_IPI_amo |= IPI_amo;
-	spin_unlock_irqrestore(&part->IPI_lock, irq_flags);
-
-	dev_dbg(xpc_chan, "received IPI from partid=%d, IPI_amo=0x%lx\n",
-		XPC_PARTID(part), IPI_amo);
-
-	xpc_wakeup_channel_mgr(part);
-}
-
 #endif /* _DRIVERS_MISC_SGIXP_XPC_H */
diff --git a/drivers/misc/sgi-xp/xpc_channel.c b/drivers/misc/sgi-xp/xpc_channel.c
index 9c90c2d55c0..9cd2ebe2a3b 100644
--- a/drivers/misc/sgi-xp/xpc_channel.c
+++ b/drivers/misc/sgi-xp/xpc_channel.c
@@ -14,536 +14,10 @@
  *
  */
 
-#include <linux/kernel.h>
-#include <linux/init.h>
-#include <linux/sched.h>
-#include <linux/cache.h>
-#include <linux/interrupt.h>
-#include <linux/mutex.h>
-#include <linux/completion.h>
-#include <asm/sn/bte.h>
-#include <asm/sn/sn_sal.h>
+#include <linux/device.h>
 #include "xpc.h"
 
 /*
- * Guarantee that the kzalloc'd memory is cacheline aligned.
- */
-static void *
-xpc_kzalloc_cacheline_aligned(size_t size, gfp_t flags, void **base)
-{
-	/* see if kzalloc will give us cachline aligned memory by default */
-	*base = kzalloc(size, flags);
-	if (*base == NULL)
-		return NULL;
-
-	if ((u64)*base == L1_CACHE_ALIGN((u64)*base))
-		return *base;
-
-	kfree(*base);
-
-	/* nope, we'll have to do it ourselves */
-	*base = kzalloc(size + L1_CACHE_BYTES, flags);
-	if (*base == NULL)
-		return NULL;
-
-	return (void *)L1_CACHE_ALIGN((u64)*base);
-}
-
-/*
- * Set up the initial values for the XPartition Communication channels.
- */
-static void
-xpc_initialize_channels(struct xpc_partition *part, short partid)
-{
-	int ch_number;
-	struct xpc_channel *ch;
-
-	for (ch_number = 0; ch_number < part->nchannels; ch_number++) {
-		ch = &part->channels[ch_number];
-
-		ch->partid = partid;
-		ch->number = ch_number;
-		ch->flags = XPC_C_DISCONNECTED;
-
-		ch->local_GP = &part->local_GPs[ch_number];
-		ch->local_openclose_args =
-		    &part->local_openclose_args[ch_number];
-
-		atomic_set(&ch->kthreads_assigned, 0);
-		atomic_set(&ch->kthreads_idle, 0);
-		atomic_set(&ch->kthreads_active, 0);
-
-		atomic_set(&ch->references, 0);
-		atomic_set(&ch->n_to_notify, 0);
-
-		spin_lock_init(&ch->lock);
-		mutex_init(&ch->msg_to_pull_mutex);
-		init_completion(&ch->wdisconnect_wait);
-
-		atomic_set(&ch->n_on_msg_allocate_wq, 0);
-		init_waitqueue_head(&ch->msg_allocate_wq);
-		init_waitqueue_head(&ch->idle_wq);
-	}
-}
-
-/*
- * Setup the infrastructure necessary to support XPartition Communication
- * between the specified remote partition and the local one.
- */
-enum xp_retval
-xpc_setup_infrastructure(struct xpc_partition *part)
-{
-	int ret, cpuid;
-	struct timer_list *timer;
-	short partid = XPC_PARTID(part);
-
-	/*
-	 * Zero out MOST of the entry for this partition. Only the fields
-	 * starting with `nchannels' will be zeroed. The preceding fields must
-	 * remain `viable' across partition ups and downs, since they may be
-	 * referenced during this memset() operation.
-	 */
-	memset(&part->nchannels, 0, sizeof(struct xpc_partition) -
-	       offsetof(struct xpc_partition, nchannels));
-
-	/*
-	 * Allocate all of the channel structures as a contiguous chunk of
-	 * memory.
-	 */
-	part->channels = kzalloc(sizeof(struct xpc_channel) * XPC_NCHANNELS,
-				 GFP_KERNEL);
-	if (part->channels == NULL) {
-		dev_err(xpc_chan, "can't get memory for channels\n");
-		return xpNoMemory;
-	}
-
-	part->nchannels = XPC_NCHANNELS;
-
-	/* allocate all the required GET/PUT values */
-
-	part->local_GPs = xpc_kzalloc_cacheline_aligned(XPC_GP_SIZE,
-							GFP_KERNEL,
-							&part->local_GPs_base);
-	if (part->local_GPs == NULL) {
-		kfree(part->channels);
-		part->channels = NULL;
-		dev_err(xpc_chan, "can't get memory for local get/put "
-			"values\n");
-		return xpNoMemory;
-	}
-
-	part->remote_GPs = xpc_kzalloc_cacheline_aligned(XPC_GP_SIZE,
-							 GFP_KERNEL,
-							 &part->
-							 remote_GPs_base);
-	if (part->remote_GPs == NULL) {
-		dev_err(xpc_chan, "can't get memory for remote get/put "
-			"values\n");
-		kfree(part->local_GPs_base);
-		part->local_GPs = NULL;
-		kfree(part->channels);
-		part->channels = NULL;
-		return xpNoMemory;
-	}
-
-	/* allocate all the required open and close args */
-
-	part->local_openclose_args =
-	    xpc_kzalloc_cacheline_aligned(XPC_OPENCLOSE_ARGS_SIZE, GFP_KERNEL,
-					  &part->local_openclose_args_base);
-	if (part->local_openclose_args == NULL) {
-		dev_err(xpc_chan, "can't get memory for local connect args\n");
-		kfree(part->remote_GPs_base);
-		part->remote_GPs = NULL;
-		kfree(part->local_GPs_base);
-		part->local_GPs = NULL;
-		kfree(part->channels);
-		part->channels = NULL;
-		return xpNoMemory;
-	}
-
-	part->remote_openclose_args =
-	    xpc_kzalloc_cacheline_aligned(XPC_OPENCLOSE_ARGS_SIZE, GFP_KERNEL,
-					  &part->remote_openclose_args_base);
-	if (part->remote_openclose_args == NULL) {
-		dev_err(xpc_chan, "can't get memory for remote connect args\n");
-		kfree(part->local_openclose_args_base);
-		part->local_openclose_args = NULL;
-		kfree(part->remote_GPs_base);
-		part->remote_GPs = NULL;
-		kfree(part->local_GPs_base);
-		part->local_GPs = NULL;
-		kfree(part->channels);
-		part->channels = NULL;
-		return xpNoMemory;
-	}
-
-	xpc_initialize_channels(part, partid);
-
-	atomic_set(&part->nchannels_active, 0);
-	atomic_set(&part->nchannels_engaged, 0);
-
-	/* local_IPI_amo were set to 0 by an earlier memset() */
-
-	/* Initialize this partitions AMO_t structure */
-	part->local_IPI_amo_va = xpc_IPI_init(partid);
-
-	spin_lock_init(&part->IPI_lock);
-
-	atomic_set(&part->channel_mgr_requests, 1);
-	init_waitqueue_head(&part->channel_mgr_wq);
-
-	sprintf(part->IPI_owner, "xpc%02d", partid);
-	ret = request_irq(SGI_XPC_NOTIFY, xpc_notify_IRQ_handler, IRQF_SHARED,
-			  part->IPI_owner, (void *)(u64)partid);
-	if (ret != 0) {
-		dev_err(xpc_chan, "can't register NOTIFY IRQ handler, "
-			"errno=%d\n", -ret);
-		kfree(part->remote_openclose_args_base);
-		part->remote_openclose_args = NULL;
-		kfree(part->local_openclose_args_base);
-		part->local_openclose_args = NULL;
-		kfree(part->remote_GPs_base);
-		part->remote_GPs = NULL;
-		kfree(part->local_GPs_base);
-		part->local_GPs = NULL;
-		kfree(part->channels);
-		part->channels = NULL;
-		return xpLackOfResources;
-	}
-
-	/* Setup a timer to check for dropped IPIs */
-	timer = &part->dropped_IPI_timer;
-	init_timer(timer);
-	timer->function = (void (*)(unsigned long))xpc_dropped_IPI_check;
-	timer->data = (unsigned long)part;
-	timer->expires = jiffies + XPC_P_DROPPED_IPI_WAIT;
-	add_timer(timer);
-
-	/*
-	 * With the setting of the partition setup_state to XPC_P_SETUP, we're
-	 * declaring that this partition is ready to go.
-	 */
-	part->setup_state = XPC_P_SETUP;
-
-	/*
-	 * Setup the per partition specific variables required by the
-	 * remote partition to establish channel connections with us.
-	 *
-	 * The setting of the magic # indicates that these per partition
-	 * specific variables are ready to be used.
-	 */
-	xpc_vars_part[partid].GPs_pa = __pa(part->local_GPs);
-	xpc_vars_part[partid].openclose_args_pa =
-	    __pa(part->local_openclose_args);
-	xpc_vars_part[partid].IPI_amo_pa = __pa(part->local_IPI_amo_va);
-	cpuid = raw_smp_processor_id();	/* any CPU in this partition will do */
-	xpc_vars_part[partid].IPI_nasid = cpuid_to_nasid(cpuid);
-	xpc_vars_part[partid].IPI_phys_cpuid = cpu_physical_id(cpuid);
-	xpc_vars_part[partid].nchannels = part->nchannels;
-	xpc_vars_part[partid].magic = XPC_VP_MAGIC1;
-
-	return xpSuccess;
-}
-
-/*
- * Create a wrapper that hides the underlying mechanism for pulling a cacheline
- * (or multiple cachelines) from a remote partition.
- *
- * src must be a cacheline aligned physical address on the remote partition.
- * dst must be a cacheline aligned virtual address on this partition.
- * cnt must be an cacheline sized
- */
-static enum xp_retval
-xpc_pull_remote_cachelines(struct xpc_partition *part, void *dst,
-			   const void *src, size_t cnt)
-{
-	bte_result_t bte_ret;
-
-	DBUG_ON((u64)src != L1_CACHE_ALIGN((u64)src));
-	DBUG_ON((u64)dst != L1_CACHE_ALIGN((u64)dst));
-	DBUG_ON(cnt != L1_CACHE_ALIGN(cnt));
-
-	if (part->act_state == XPC_P_DEACTIVATING)
-		return part->reason;
-
-	bte_ret = xp_bte_copy((u64)src, (u64)dst, (u64)cnt,
-			      (BTE_NORMAL | BTE_WACQUIRE), NULL);
-	if (bte_ret == BTE_SUCCESS)
-		return xpSuccess;
-
-	dev_dbg(xpc_chan, "xp_bte_copy() from partition %d failed, ret=%d\n",
-		XPC_PARTID(part), bte_ret);
-
-	return xpc_map_bte_errors(bte_ret);
-}
-
-/*
- * Pull the remote per partition specific variables from the specified
- * partition.
- */
-enum xp_retval
-xpc_pull_remote_vars_part(struct xpc_partition *part)
-{
-	u8 buffer[L1_CACHE_BYTES * 2];
-	struct xpc_vars_part *pulled_entry_cacheline =
-	    (struct xpc_vars_part *)L1_CACHE_ALIGN((u64)buffer);
-	struct xpc_vars_part *pulled_entry;
-	u64 remote_entry_cacheline_pa, remote_entry_pa;
-	short partid = XPC_PARTID(part);
-	enum xp_retval ret;
-
-	/* pull the cacheline that contains the variables we're interested in */
-
-	DBUG_ON(part->remote_vars_part_pa !=
-		L1_CACHE_ALIGN(part->remote_vars_part_pa));
-	DBUG_ON(sizeof(struct xpc_vars_part) != L1_CACHE_BYTES / 2);
-
-	remote_entry_pa = part->remote_vars_part_pa +
-	    sn_partition_id * sizeof(struct xpc_vars_part);
-
-	remote_entry_cacheline_pa = (remote_entry_pa & ~(L1_CACHE_BYTES - 1));
-
-	pulled_entry = (struct xpc_vars_part *)((u64)pulled_entry_cacheline +
-						(remote_entry_pa &
-						 (L1_CACHE_BYTES - 1)));
-
-	ret = xpc_pull_remote_cachelines(part, pulled_entry_cacheline,
-					 (void *)remote_entry_cacheline_pa,
-					 L1_CACHE_BYTES);
-	if (ret != xpSuccess) {
-		dev_dbg(xpc_chan, "failed to pull XPC vars_part from "
-			"partition %d, ret=%d\n", partid, ret);
-		return ret;
-	}
-
-	/* see if they've been set up yet */
-
-	if (pulled_entry->magic != XPC_VP_MAGIC1 &&
-	    pulled_entry->magic != XPC_VP_MAGIC2) {
-
-		if (pulled_entry->magic != 0) {
-			dev_dbg(xpc_chan, "partition %d's XPC vars_part for "
-				"partition %d has bad magic value (=0x%lx)\n",
-				partid, sn_partition_id, pulled_entry->magic);
-			return xpBadMagic;
-		}
-
-		/* they've not been initialized yet */
-		return xpRetry;
-	}
-
-	if (xpc_vars_part[partid].magic == XPC_VP_MAGIC1) {
-
-		/* validate the variables */
-
-		if (pulled_entry->GPs_pa == 0 ||
-		    pulled_entry->openclose_args_pa == 0 ||
-		    pulled_entry->IPI_amo_pa == 0) {
-
-			dev_err(xpc_chan, "partition %d's XPC vars_part for "
-				"partition %d are not valid\n", partid,
-				sn_partition_id);
-			return xpInvalidAddress;
-		}
-
-		/* the variables we imported look to be valid */
-
-		part->remote_GPs_pa = pulled_entry->GPs_pa;
-		part->remote_openclose_args_pa =
-		    pulled_entry->openclose_args_pa;
-		part->remote_IPI_amo_va =
-		    (AMO_t *)__va(pulled_entry->IPI_amo_pa);
-		part->remote_IPI_nasid = pulled_entry->IPI_nasid;
-		part->remote_IPI_phys_cpuid = pulled_entry->IPI_phys_cpuid;
-
-		if (part->nchannels > pulled_entry->nchannels)
-			part->nchannels = pulled_entry->nchannels;
-
-		/* let the other side know that we've pulled their variables */
-
-		xpc_vars_part[partid].magic = XPC_VP_MAGIC2;
-	}
-
-	if (pulled_entry->magic == XPC_VP_MAGIC1)
-		return xpRetry;
-
-	return xpSuccess;
-}
-
-/*
- * Get the IPI flags and pull the openclose args and/or remote GPs as needed.
- */
-static u64
-xpc_get_IPI_flags(struct xpc_partition *part)
-{
-	unsigned long irq_flags;
-	u64 IPI_amo;
-	enum xp_retval ret;
-
-	/*
-	 * See if there are any IPI flags to be handled.
-	 */
-
-	spin_lock_irqsave(&part->IPI_lock, irq_flags);
-	IPI_amo = part->local_IPI_amo;
-	if (IPI_amo != 0)
-		part->local_IPI_amo = 0;
-
-	spin_unlock_irqrestore(&part->IPI_lock, irq_flags);
-
-	if (XPC_ANY_OPENCLOSE_IPI_FLAGS_SET(IPI_amo)) {
-		ret = xpc_pull_remote_cachelines(part,
-						 part->remote_openclose_args,
-						 (void *)part->
-						 remote_openclose_args_pa,
-						 XPC_OPENCLOSE_ARGS_SIZE);
-		if (ret != xpSuccess) {
-			XPC_DEACTIVATE_PARTITION(part, ret);
-
-			dev_dbg(xpc_chan, "failed to pull openclose args from "
-				"partition %d, ret=%d\n", XPC_PARTID(part),
-				ret);
-
-			/* don't bother processing IPIs anymore */
-			IPI_amo = 0;
-		}
-	}
-
-	if (XPC_ANY_MSG_IPI_FLAGS_SET(IPI_amo)) {
-		ret = xpc_pull_remote_cachelines(part, part->remote_GPs,
-						 (void *)part->remote_GPs_pa,
-						 XPC_GP_SIZE);
-		if (ret != xpSuccess) {
-			XPC_DEACTIVATE_PARTITION(part, ret);
-
-			dev_dbg(xpc_chan, "failed to pull GPs from partition "
-				"%d, ret=%d\n", XPC_PARTID(part), ret);
-
-			/* don't bother processing IPIs anymore */
-			IPI_amo = 0;
-		}
-	}
-
-	return IPI_amo;
-}
-
-/*
- * Allocate the local message queue and the notify queue.
- */
-static enum xp_retval
-xpc_allocate_local_msgqueue(struct xpc_channel *ch)
-{
-	unsigned long irq_flags;
-	int nentries;
-	size_t nbytes;
-
-	for (nentries = ch->local_nentries; nentries > 0; nentries--) {
-
-		nbytes = nentries * ch->msg_size;
-		ch->local_msgqueue = xpc_kzalloc_cacheline_aligned(nbytes,
-								   GFP_KERNEL,
-						      &ch->local_msgqueue_base);
-		if (ch->local_msgqueue == NULL)
-			continue;
-
-		nbytes = nentries * sizeof(struct xpc_notify);
-		ch->notify_queue = kzalloc(nbytes, GFP_KERNEL);
-		if (ch->notify_queue == NULL) {
-			kfree(ch->local_msgqueue_base);
-			ch->local_msgqueue = NULL;
-			continue;
-		}
-
-		spin_lock_irqsave(&ch->lock, irq_flags);
-		if (nentries < ch->local_nentries) {
-			dev_dbg(xpc_chan, "nentries=%d local_nentries=%d, "
-				"partid=%d, channel=%d\n", nentries,
-				ch->local_nentries, ch->partid, ch->number);
-
-			ch->local_nentries = nentries;
-		}
-		spin_unlock_irqrestore(&ch->lock, irq_flags);
-		return xpSuccess;
-	}
-
-	dev_dbg(xpc_chan, "can't get memory for local message queue and notify "
-		"queue, partid=%d, channel=%d\n", ch->partid, ch->number);
-	return xpNoMemory;
-}
-
-/*
- * Allocate the cached remote message queue.
- */
-static enum xp_retval
-xpc_allocate_remote_msgqueue(struct xpc_channel *ch)
-{
-	unsigned long irq_flags;
-	int nentries;
-	size_t nbytes;
-
-	DBUG_ON(ch->remote_nentries <= 0);
-
-	for (nentries = ch->remote_nentries; nentries > 0; nentries--) {
-
-		nbytes = nentries * ch->msg_size;
-		ch->remote_msgqueue = xpc_kzalloc_cacheline_aligned(nbytes,
-								    GFP_KERNEL,
-						     &ch->remote_msgqueue_base);
-		if (ch->remote_msgqueue == NULL)
-			continue;
-
-		spin_lock_irqsave(&ch->lock, irq_flags);
-		if (nentries < ch->remote_nentries) {
-			dev_dbg(xpc_chan, "nentries=%d remote_nentries=%d, "
-				"partid=%d, channel=%d\n", nentries,
-				ch->remote_nentries, ch->partid, ch->number);
-
-			ch->remote_nentries = nentries;
-		}
-		spin_unlock_irqrestore(&ch->lock, irq_flags);
-		return xpSuccess;
-	}
-
-	dev_dbg(xpc_chan, "can't get memory for cached remote message queue, "
-		"partid=%d, channel=%d\n", ch->partid, ch->number);
-	return xpNoMemory;
-}
-
-/*
- * Allocate message queues and other stuff associated with a channel.
- *
- * Note: Assumes all of the channel sizes are filled in.
- */
-static enum xp_retval
-xpc_allocate_msgqueues(struct xpc_channel *ch)
-{
-	unsigned long irq_flags;
-	enum xp_retval ret;
-
-	DBUG_ON(ch->flags & XPC_C_SETUP);
-
-	ret = xpc_allocate_local_msgqueue(ch);
-	if (ret != xpSuccess)
-		return ret;
-
-	ret = xpc_allocate_remote_msgqueue(ch);
-	if (ret != xpSuccess) {
-		kfree(ch->local_msgqueue_base);
-		ch->local_msgqueue = NULL;
-		kfree(ch->notify_queue);
-		ch->notify_queue = NULL;
-		return ret;
-	}
-
-	spin_lock_irqsave(&ch->lock, irq_flags);
-	ch->flags |= XPC_C_SETUP;
-	spin_unlock_irqrestore(&ch->lock, irq_flags);
-
-	return xpSuccess;
-}
-
-/*
  * Process a connect message from a remote partition.
  *
  * Note: xpc_process_connect() is expecting to be called with the
@@ -565,30 +39,29 @@ xpc_process_connect(struct xpc_channel *ch, unsigned long *irq_flags)
 
 	if (!(ch->flags & XPC_C_SETUP)) {
 		spin_unlock_irqrestore(&ch->lock, *irq_flags);
-		ret = xpc_allocate_msgqueues(ch);
+		ret = xpc_setup_msg_structures(ch);
 		spin_lock_irqsave(&ch->lock, *irq_flags);
 
 		if (ret != xpSuccess)
 			XPC_DISCONNECT_CHANNEL(ch, ret, irq_flags);
 
+		ch->flags |= XPC_C_SETUP;
+
 		if (ch->flags & (XPC_C_CONNECTED | XPC_C_DISCONNECTING))
 			return;
 
-		DBUG_ON(!(ch->flags & XPC_C_SETUP));
 		DBUG_ON(ch->local_msgqueue == NULL);
 		DBUG_ON(ch->remote_msgqueue == NULL);
 	}
 
 	if (!(ch->flags & XPC_C_OPENREPLY)) {
 		ch->flags |= XPC_C_OPENREPLY;
-		xpc_IPI_send_openreply(ch, irq_flags);
+		xpc_send_chctl_openreply(ch, irq_flags);
 	}
 
 	if (!(ch->flags & XPC_C_ROPENREPLY))
 		return;
 
-	DBUG_ON(ch->remote_msgqueue_pa == 0);
-
 	ch->flags = (XPC_C_CONNECTED | XPC_C_SETUP);	/* clear all else */
 
 	dev_info(xpc_chan, "channel %d to partition %d connected\n",
@@ -600,99 +73,6 @@ xpc_process_connect(struct xpc_channel *ch, unsigned long *irq_flags)
 }
 
 /*
- * Notify those who wanted to be notified upon delivery of their message.
- */
-static void
-xpc_notify_senders(struct xpc_channel *ch, enum xp_retval reason, s64 put)
-{
-	struct xpc_notify *notify;
-	u8 notify_type;
-	s64 get = ch->w_remote_GP.get - 1;
-
-	while (++get < put && atomic_read(&ch->n_to_notify) > 0) {
-
-		notify = &ch->notify_queue[get % ch->local_nentries];
-
-		/*
-		 * See if the notify entry indicates it was associated with
-		 * a message who's sender wants to be notified. It is possible
-		 * that it is, but someone else is doing or has done the
-		 * notification.
-		 */
-		notify_type = notify->type;
-		if (notify_type == 0 ||
-		    cmpxchg(&notify->type, notify_type, 0) != notify_type) {
-			continue;
-		}
-
-		DBUG_ON(notify_type != XPC_N_CALL);
-
-		atomic_dec(&ch->n_to_notify);
-
-		if (notify->func != NULL) {
-			dev_dbg(xpc_chan, "notify->func() called, notify=0x%p, "
-				"msg_number=%ld, partid=%d, channel=%d\n",
-				(void *)notify, get, ch->partid, ch->number);
-
-			notify->func(reason, ch->partid, ch->number,
-				     notify->key);
-
-			dev_dbg(xpc_chan, "notify->func() returned, "
-				"notify=0x%p, msg_number=%ld, partid=%d, "
-				"channel=%d\n", (void *)notify, get,
-				ch->partid, ch->number);
-		}
-	}
-}
-
-/*
- * Free up message queues and other stuff that were allocated for the specified
- * channel.
- *
- * Note: ch->reason and ch->reason_line are left set for debugging purposes,
- * they're cleared when XPC_C_DISCONNECTED is cleared.
- */
-static void
-xpc_free_msgqueues(struct xpc_channel *ch)
-{
-	DBUG_ON(!spin_is_locked(&ch->lock));
-	DBUG_ON(atomic_read(&ch->n_to_notify) != 0);
-
-	ch->remote_msgqueue_pa = 0;
-	ch->func = NULL;
-	ch->key = NULL;
-	ch->msg_size = 0;
-	ch->local_nentries = 0;
-	ch->remote_nentries = 0;
-	ch->kthreads_assigned_limit = 0;
-	ch->kthreads_idle_limit = 0;
-
-	ch->local_GP->get = 0;
-	ch->local_GP->put = 0;
-	ch->remote_GP.get = 0;
-	ch->remote_GP.put = 0;
-	ch->w_local_GP.get = 0;
-	ch->w_local_GP.put = 0;
-	ch->w_remote_GP.get = 0;
-	ch->w_remote_GP.put = 0;
-	ch->next_msg_to_pull = 0;
-
-	if (ch->flags & XPC_C_SETUP) {
-		ch->flags &= ~XPC_C_SETUP;
-
-		dev_dbg(xpc_chan, "ch->flags=0x%x, partid=%d, channel=%d\n",
-			ch->flags, ch->partid, ch->number);
-
-		kfree(ch->local_msgqueue_base);
-		ch->local_msgqueue = NULL;
-		kfree(ch->remote_msgqueue_base);
-		ch->remote_msgqueue = NULL;
-		kfree(ch->notify_queue);
-		ch->notify_queue = NULL;
-	}
-}
-
-/*
  * spin_lock_irqsave() is expected to be held on entry.
  */
 static void
@@ -717,9 +97,9 @@ xpc_process_disconnect(struct xpc_channel *ch, unsigned long *irq_flags)
 	DBUG_ON((ch->flags & XPC_C_CONNECTEDCALLOUT_MADE) &&
 		!(ch->flags & XPC_C_DISCONNECTINGCALLOUT_MADE));
 
-	if (part->act_state == XPC_P_DEACTIVATING) {
+	if (part->act_state == XPC_P_AS_DEACTIVATING) {
 		/* can't proceed until the other side disengages from us */
-		if (xpc_partition_engaged(1UL << ch->partid))
+		if (xpc_partition_engaged(ch->partid))
 			return;
 
 	} else {
@@ -731,7 +111,7 @@ xpc_process_disconnect(struct xpc_channel *ch, unsigned long *irq_flags)
 
 		if (!(ch->flags & XPC_C_CLOSEREPLY)) {
 			ch->flags |= XPC_C_CLOSEREPLY;
-			xpc_IPI_send_closereply(ch, irq_flags);
+			xpc_send_chctl_closereply(ch, irq_flags);
 		}
 
 		if (!(ch->flags & XPC_C_RCLOSEREPLY))
@@ -740,8 +120,8 @@ xpc_process_disconnect(struct xpc_channel *ch, unsigned long *irq_flags)
 
 	/* wake those waiting for notify completion */
 	if (atomic_read(&ch->n_to_notify) > 0) {
-		/* >>> we do callout while holding ch->lock */
-		xpc_notify_senders(ch, ch->reason, ch->w_local_GP.put);
+		/* we do callout while holding ch->lock, callout can't block */
+		xpc_notify_senders_of_disconnect(ch);
 	}
 
 	/* both sides are disconnected now */
@@ -752,10 +132,24 @@ xpc_process_disconnect(struct xpc_channel *ch, unsigned long *irq_flags)
 		spin_lock_irqsave(&ch->lock, *irq_flags);
 	}
 
+	DBUG_ON(atomic_read(&ch->n_to_notify) != 0);
+
 	/* it's now safe to free the channel's message queues */
-	xpc_free_msgqueues(ch);
+	xpc_teardown_msg_structures(ch);
 
-	/* mark disconnected, clear all other flags except XPC_C_WDISCONNECT */
+	ch->func = NULL;
+	ch->key = NULL;
+	ch->entry_size = 0;
+	ch->local_nentries = 0;
+	ch->remote_nentries = 0;
+	ch->kthreads_assigned_limit = 0;
+	ch->kthreads_idle_limit = 0;
+
+	/*
+	 * Mark the channel disconnected and clear all other flags, including
+	 * XPC_C_SETUP (because of call to xpc_teardown_msg_structures()) but
+	 * not including XPC_C_WDISCONNECT (if it was set).
+	 */
 	ch->flags = (XPC_C_DISCONNECTED | (ch->flags & XPC_C_WDISCONNECT));
 
 	atomic_dec(&part->nchannels_active);
@@ -768,15 +162,15 @@ xpc_process_disconnect(struct xpc_channel *ch, unsigned long *irq_flags)
 	if (ch->flags & XPC_C_WDISCONNECT) {
 		/* we won't lose the CPU since we're holding ch->lock */
 		complete(&ch->wdisconnect_wait);
-	} else if (ch->delayed_IPI_flags) {
-		if (part->act_state != XPC_P_DEACTIVATING) {
-			/* time to take action on any delayed IPI flags */
-			spin_lock(&part->IPI_lock);
-			XPC_SET_IPI_FLAGS(part->local_IPI_amo, ch->number,
-					  ch->delayed_IPI_flags);
-			spin_unlock(&part->IPI_lock);
+	} else if (ch->delayed_chctl_flags) {
+		if (part->act_state != XPC_P_AS_DEACTIVATING) {
+			/* time to take action on any delayed chctl flags */
+			spin_lock(&part->chctl_lock);
+			part->chctl.flags[ch->number] |=
+			    ch->delayed_chctl_flags;
+			spin_unlock(&part->chctl_lock);
 		}
-		ch->delayed_IPI_flags = 0;
+		ch->delayed_chctl_flags = 0;
 	}
 }
 
@@ -784,8 +178,8 @@ xpc_process_disconnect(struct xpc_channel *ch, unsigned long *irq_flags)
  * Process a change in the channel's remote connection state.
  */
 static void
-xpc_process_openclose_IPI(struct xpc_partition *part, int ch_number,
-			  u8 IPI_flags)
+xpc_process_openclose_chctl_flags(struct xpc_partition *part, int ch_number,
+				  u8 chctl_flags)
 {
 	unsigned long irq_flags;
 	struct xpc_openclose_args *args =
@@ -800,24 +194,24 @@ again:
 	if ((ch->flags & XPC_C_DISCONNECTED) &&
 	    (ch->flags & XPC_C_WDISCONNECT)) {
 		/*
-		 * Delay processing IPI flags until thread waiting disconnect
+		 * Delay processing chctl flags until thread waiting disconnect
 		 * has had a chance to see that the channel is disconnected.
 		 */
-		ch->delayed_IPI_flags |= IPI_flags;
+		ch->delayed_chctl_flags |= chctl_flags;
 		spin_unlock_irqrestore(&ch->lock, irq_flags);
 		return;
 	}
 
-	if (IPI_flags & XPC_IPI_CLOSEREQUEST) {
+	if (chctl_flags & XPC_CHCTL_CLOSEREQUEST) {
 
-		dev_dbg(xpc_chan, "XPC_IPI_CLOSEREQUEST (reason=%d) received "
+		dev_dbg(xpc_chan, "XPC_CHCTL_CLOSEREQUEST (reason=%d) received "
 			"from partid=%d, channel=%d\n", args->reason,
 			ch->partid, ch->number);
 
 		/*
 		 * If RCLOSEREQUEST is set, we're probably waiting for
 		 * RCLOSEREPLY. We should find it and a ROPENREQUEST packed
-		 * with this RCLOSEREQUEST in the IPI_flags.
+		 * with this RCLOSEREQUEST in the chctl_flags.
 		 */
 
 		if (ch->flags & XPC_C_RCLOSEREQUEST) {
@@ -826,8 +220,8 @@ again:
 			DBUG_ON(!(ch->flags & XPC_C_CLOSEREPLY));
 			DBUG_ON(ch->flags & XPC_C_RCLOSEREPLY);
 
-			DBUG_ON(!(IPI_flags & XPC_IPI_CLOSEREPLY));
-			IPI_flags &= ~XPC_IPI_CLOSEREPLY;
+			DBUG_ON(!(chctl_flags & XPC_CHCTL_CLOSEREPLY));
+			chctl_flags &= ~XPC_CHCTL_CLOSEREPLY;
 			ch->flags |= XPC_C_RCLOSEREPLY;
 
 			/* both sides have finished disconnecting */
@@ -837,17 +231,15 @@ again:
 		}
 
 		if (ch->flags & XPC_C_DISCONNECTED) {
-			if (!(IPI_flags & XPC_IPI_OPENREQUEST)) {
-				if ((XPC_GET_IPI_FLAGS(part->local_IPI_amo,
-						       ch_number) &
-				     XPC_IPI_OPENREQUEST)) {
-
-					DBUG_ON(ch->delayed_IPI_flags != 0);
-					spin_lock(&part->IPI_lock);
-					XPC_SET_IPI_FLAGS(part->local_IPI_amo,
-							  ch_number,
-							  XPC_IPI_CLOSEREQUEST);
-					spin_unlock(&part->IPI_lock);
+			if (!(chctl_flags & XPC_CHCTL_OPENREQUEST)) {
+				if (part->chctl.flags[ch_number] &
+				    XPC_CHCTL_OPENREQUEST) {
+
+					DBUG_ON(ch->delayed_chctl_flags != 0);
+					spin_lock(&part->chctl_lock);
+					part->chctl.flags[ch_number] |=
+					    XPC_CHCTL_CLOSEREQUEST;
+					spin_unlock(&part->chctl_lock);
 				}
 				spin_unlock_irqrestore(&ch->lock, irq_flags);
 				return;
@@ -860,7 +252,7 @@ again:
 			ch->flags |= (XPC_C_CONNECTING | XPC_C_ROPENREQUEST);
 		}
 
-		IPI_flags &= ~(XPC_IPI_OPENREQUEST | XPC_IPI_OPENREPLY);
+		chctl_flags &= ~(XPC_CHCTL_OPENREQUEST | XPC_CHCTL_OPENREPLY);
 
 		/*
 		 * The meaningful CLOSEREQUEST connection state fields are:
@@ -878,7 +270,7 @@ again:
 
 			XPC_DISCONNECT_CHANNEL(ch, reason, &irq_flags);
 
-			DBUG_ON(IPI_flags & XPC_IPI_CLOSEREPLY);
+			DBUG_ON(chctl_flags & XPC_CHCTL_CLOSEREPLY);
 			spin_unlock_irqrestore(&ch->lock, irq_flags);
 			return;
 		}
@@ -886,13 +278,13 @@ again:
 		xpc_process_disconnect(ch, &irq_flags);
 	}
 
-	if (IPI_flags & XPC_IPI_CLOSEREPLY) {
+	if (chctl_flags & XPC_CHCTL_CLOSEREPLY) {
 
-		dev_dbg(xpc_chan, "XPC_IPI_CLOSEREPLY received from partid=%d,"
-			" channel=%d\n", ch->partid, ch->number);
+		dev_dbg(xpc_chan, "XPC_CHCTL_CLOSEREPLY received from partid="
+			"%d, channel=%d\n", ch->partid, ch->number);
 
 		if (ch->flags & XPC_C_DISCONNECTED) {
-			DBUG_ON(part->act_state != XPC_P_DEACTIVATING);
+			DBUG_ON(part->act_state != XPC_P_AS_DEACTIVATING);
 			spin_unlock_irqrestore(&ch->lock, irq_flags);
 			return;
 		}
@@ -900,15 +292,14 @@ again:
 		DBUG_ON(!(ch->flags & XPC_C_CLOSEREQUEST));
 
 		if (!(ch->flags & XPC_C_RCLOSEREQUEST)) {
-			if ((XPC_GET_IPI_FLAGS(part->local_IPI_amo, ch_number)
-			     & XPC_IPI_CLOSEREQUEST)) {
-
-				DBUG_ON(ch->delayed_IPI_flags != 0);
-				spin_lock(&part->IPI_lock);
-				XPC_SET_IPI_FLAGS(part->local_IPI_amo,
-						  ch_number,
-						  XPC_IPI_CLOSEREPLY);
-				spin_unlock(&part->IPI_lock);
+			if (part->chctl.flags[ch_number] &
+			    XPC_CHCTL_CLOSEREQUEST) {
+
+				DBUG_ON(ch->delayed_chctl_flags != 0);
+				spin_lock(&part->chctl_lock);
+				part->chctl.flags[ch_number] |=
+				    XPC_CHCTL_CLOSEREPLY;
+				spin_unlock(&part->chctl_lock);
 			}
 			spin_unlock_irqrestore(&ch->lock, irq_flags);
 			return;
@@ -922,21 +313,21 @@ again:
 		}
 	}
 
-	if (IPI_flags & XPC_IPI_OPENREQUEST) {
+	if (chctl_flags & XPC_CHCTL_OPENREQUEST) {
 
-		dev_dbg(xpc_chan, "XPC_IPI_OPENREQUEST (msg_size=%d, "
+		dev_dbg(xpc_chan, "XPC_CHCTL_OPENREQUEST (entry_size=%d, "
 			"local_nentries=%d) received from partid=%d, "
-			"channel=%d\n", args->msg_size, args->local_nentries,
+			"channel=%d\n", args->entry_size, args->local_nentries,
 			ch->partid, ch->number);
 
-		if (part->act_state == XPC_P_DEACTIVATING ||
+		if (part->act_state == XPC_P_AS_DEACTIVATING ||
 		    (ch->flags & XPC_C_ROPENREQUEST)) {
 			spin_unlock_irqrestore(&ch->lock, irq_flags);
 			return;
 		}
 
 		if (ch->flags & (XPC_C_DISCONNECTING | XPC_C_WDISCONNECT)) {
-			ch->delayed_IPI_flags |= XPC_IPI_OPENREQUEST;
+			ch->delayed_chctl_flags |= XPC_CHCTL_OPENREQUEST;
 			spin_unlock_irqrestore(&ch->lock, irq_flags);
 			return;
 		}
@@ -947,10 +338,10 @@ again:
 
 		/*
 		 * The meaningful OPENREQUEST connection state fields are:
-		 *      msg_size = size of channel's messages in bytes
+		 *      entry_size = size of channel's messages in bytes
 		 *      local_nentries = remote partition's local_nentries
 		 */
-		if (args->msg_size == 0 || args->local_nentries == 0) {
+		if (args->entry_size == 0 || args->local_nentries == 0) {
 			/* assume OPENREQUEST was delayed by mistake */
 			spin_unlock_irqrestore(&ch->lock, irq_flags);
 			return;
@@ -960,14 +351,14 @@ again:
 		ch->remote_nentries = args->local_nentries;
 
 		if (ch->flags & XPC_C_OPENREQUEST) {
-			if (args->msg_size != ch->msg_size) {
+			if (args->entry_size != ch->entry_size) {
 				XPC_DISCONNECT_CHANNEL(ch, xpUnequalMsgSizes,
 						       &irq_flags);
 				spin_unlock_irqrestore(&ch->lock, irq_flags);
 				return;
 			}
 		} else {
-			ch->msg_size = args->msg_size;
+			ch->entry_size = args->entry_size;
 
 			XPC_SET_REASON(ch, 0, 0);
 			ch->flags &= ~XPC_C_DISCONNECTED;
@@ -978,13 +369,13 @@ again:
 		xpc_process_connect(ch, &irq_flags);
 	}
 
-	if (IPI_flags & XPC_IPI_OPENREPLY) {
+	if (chctl_flags & XPC_CHCTL_OPENREPLY) {
 
-		dev_dbg(xpc_chan, "XPC_IPI_OPENREPLY (local_msgqueue_pa=0x%lx, "
-			"local_nentries=%d, remote_nentries=%d) received from "
-			"partid=%d, channel=%d\n", args->local_msgqueue_pa,
-			args->local_nentries, args->remote_nentries,
-			ch->partid, ch->number);
+		dev_dbg(xpc_chan, "XPC_CHCTL_OPENREPLY (local_msgqueue_pa="
+			"0x%lx, local_nentries=%d, remote_nentries=%d) "
+			"received from partid=%d, channel=%d\n",
+			args->local_msgqueue_pa, args->local_nentries,
+			args->remote_nentries, ch->partid, ch->number);
 
 		if (ch->flags & (XPC_C_DISCONNECTING | XPC_C_DISCONNECTED)) {
 			spin_unlock_irqrestore(&ch->lock, irq_flags);
@@ -1012,10 +403,10 @@ again:
 		DBUG_ON(args->remote_nentries == 0);
 
 		ch->flags |= XPC_C_ROPENREPLY;
-		ch->remote_msgqueue_pa = args->local_msgqueue_pa;
+		xpc_save_remote_msgqueue_pa(ch, args->local_msgqueue_pa);
 
 		if (args->local_nentries < ch->remote_nentries) {
-			dev_dbg(xpc_chan, "XPC_IPI_OPENREPLY: new "
+			dev_dbg(xpc_chan, "XPC_CHCTL_OPENREPLY: new "
 				"remote_nentries=%d, old remote_nentries=%d, "
 				"partid=%d, channel=%d\n",
 				args->local_nentries, ch->remote_nentries,
@@ -1024,7 +415,7 @@ again:
 			ch->remote_nentries = args->local_nentries;
 		}
 		if (args->remote_nentries < ch->local_nentries) {
-			dev_dbg(xpc_chan, "XPC_IPI_OPENREPLY: new "
+			dev_dbg(xpc_chan, "XPC_CHCTL_OPENREPLY: new "
 				"local_nentries=%d, old local_nentries=%d, "
 				"partid=%d, channel=%d\n",
 				args->remote_nentries, ch->local_nentries,
@@ -1082,7 +473,7 @@ xpc_connect_channel(struct xpc_channel *ch)
 	ch->local_nentries = registration->nentries;
 
 	if (ch->flags & XPC_C_ROPENREQUEST) {
-		if (registration->msg_size != ch->msg_size) {
+		if (registration->entry_size != ch->entry_size) {
 			/* the local and remote sides aren't the same */
 
 			/*
@@ -1101,7 +492,7 @@ xpc_connect_channel(struct xpc_channel *ch)
 			return xpUnequalMsgSizes;
 		}
 	} else {
-		ch->msg_size = registration->msg_size;
+		ch->entry_size = registration->entry_size;
 
 		XPC_SET_REASON(ch, 0, 0);
 		ch->flags &= ~XPC_C_DISCONNECTED;
@@ -1114,7 +505,7 @@ xpc_connect_channel(struct xpc_channel *ch)
 	/* initiate the connection */
 
 	ch->flags |= (XPC_C_OPENREQUEST | XPC_C_CONNECTING);
-	xpc_IPI_send_openrequest(ch, &irq_flags);
+	xpc_send_chctl_openrequest(ch, &irq_flags);
 
 	xpc_process_connect(ch, &irq_flags);
 
@@ -1123,152 +514,16 @@ xpc_connect_channel(struct xpc_channel *ch)
 	return xpSuccess;
 }
 
-/*
- * Clear some of the msg flags in the local message queue.
- */
-static inline void
-xpc_clear_local_msgqueue_flags(struct xpc_channel *ch)
-{
-	struct xpc_msg *msg;
-	s64 get;
-
-	get = ch->w_remote_GP.get;
-	do {
-		msg = (struct xpc_msg *)((u64)ch->local_msgqueue +
-					 (get % ch->local_nentries) *
-					 ch->msg_size);
-		msg->flags = 0;
-	} while (++get < ch->remote_GP.get);
-}
-
-/*
- * Clear some of the msg flags in the remote message queue.
- */
-static inline void
-xpc_clear_remote_msgqueue_flags(struct xpc_channel *ch)
-{
-	struct xpc_msg *msg;
-	s64 put;
-
-	put = ch->w_remote_GP.put;
-	do {
-		msg = (struct xpc_msg *)((u64)ch->remote_msgqueue +
-					 (put % ch->remote_nentries) *
-					 ch->msg_size);
-		msg->flags = 0;
-	} while (++put < ch->remote_GP.put);
-}
-
-static void
-xpc_process_msg_IPI(struct xpc_partition *part, int ch_number)
-{
-	struct xpc_channel *ch = &part->channels[ch_number];
-	int nmsgs_sent;
-
-	ch->remote_GP = part->remote_GPs[ch_number];
-
-	/* See what, if anything, has changed for each connected channel */
-
-	xpc_msgqueue_ref(ch);
-
-	if (ch->w_remote_GP.get == ch->remote_GP.get &&
-	    ch->w_remote_GP.put == ch->remote_GP.put) {
-		/* nothing changed since GPs were last pulled */
-		xpc_msgqueue_deref(ch);
-		return;
-	}
-
-	if (!(ch->flags & XPC_C_CONNECTED)) {
-		xpc_msgqueue_deref(ch);
-		return;
-	}
-
-	/*
-	 * First check to see if messages recently sent by us have been
-	 * received by the other side. (The remote GET value will have
-	 * changed since we last looked at it.)
-	 */
-
-	if (ch->w_remote_GP.get != ch->remote_GP.get) {
-
-		/*
-		 * We need to notify any senders that want to be notified
-		 * that their sent messages have been received by their
-		 * intended recipients. We need to do this before updating
-		 * w_remote_GP.get so that we don't allocate the same message
-		 * queue entries prematurely (see xpc_allocate_msg()).
-		 */
-		if (atomic_read(&ch->n_to_notify) > 0) {
-			/*
-			 * Notify senders that messages sent have been
-			 * received and delivered by the other side.
-			 */
-			xpc_notify_senders(ch, xpMsgDelivered,
-					   ch->remote_GP.get);
-		}
-
-		/*
-		 * Clear msg->flags in previously sent messages, so that
-		 * they're ready for xpc_allocate_msg().
-		 */
-		xpc_clear_local_msgqueue_flags(ch);
-
-		ch->w_remote_GP.get = ch->remote_GP.get;
-
-		dev_dbg(xpc_chan, "w_remote_GP.get changed to %ld, partid=%d, "
-			"channel=%d\n", ch->w_remote_GP.get, ch->partid,
-			ch->number);
-
-		/*
-		 * If anyone was waiting for message queue entries to become
-		 * available, wake them up.
-		 */
-		if (atomic_read(&ch->n_on_msg_allocate_wq) > 0)
-			wake_up(&ch->msg_allocate_wq);
-	}
-
-	/*
-	 * Now check for newly sent messages by the other side. (The remote
-	 * PUT value will have changed since we last looked at it.)
-	 */
-
-	if (ch->w_remote_GP.put != ch->remote_GP.put) {
-		/*
-		 * Clear msg->flags in previously received messages, so that
-		 * they're ready for xpc_get_deliverable_msg().
-		 */
-		xpc_clear_remote_msgqueue_flags(ch);
-
-		ch->w_remote_GP.put = ch->remote_GP.put;
-
-		dev_dbg(xpc_chan, "w_remote_GP.put changed to %ld, partid=%d, "
-			"channel=%d\n", ch->w_remote_GP.put, ch->partid,
-			ch->number);
-
-		nmsgs_sent = ch->w_remote_GP.put - ch->w_local_GP.get;
-		if (nmsgs_sent > 0) {
-			dev_dbg(xpc_chan, "msgs waiting to be copied and "
-				"delivered=%d, partid=%d, channel=%d\n",
-				nmsgs_sent, ch->partid, ch->number);
-
-			if (ch->flags & XPC_C_CONNECTEDCALLOUT_MADE)
-				xpc_activate_kthreads(ch, nmsgs_sent);
-		}
-	}
-
-	xpc_msgqueue_deref(ch);
-}
-
 void
-xpc_process_channel_activity(struct xpc_partition *part)
+xpc_process_sent_chctl_flags(struct xpc_partition *part)
 {
 	unsigned long irq_flags;
-	u64 IPI_amo, IPI_flags;
+	union xpc_channel_ctl_flags chctl;
 	struct xpc_channel *ch;
 	int ch_number;
 	u32 ch_flags;
 
-	IPI_amo = xpc_get_IPI_flags(part);
+	chctl.all_flags = xpc_get_chctl_all_flags(part);
 
 	/*
 	 * Initiate channel connections for registered channels.
@@ -1281,14 +536,14 @@ xpc_process_channel_activity(struct xpc_partition *part)
 		ch = &part->channels[ch_number];
 
 		/*
-		 * Process any open or close related IPI flags, and then deal
+		 * Process any open or close related chctl flags, and then deal
 		 * with connecting or disconnecting the channel as required.
 		 */
 
-		IPI_flags = XPC_GET_IPI_FLAGS(IPI_amo, ch_number);
-
-		if (XPC_ANY_OPENCLOSE_IPI_FLAGS_SET(IPI_flags))
-			xpc_process_openclose_IPI(part, ch_number, IPI_flags);
+		if (chctl.flags[ch_number] & XPC_OPENCLOSE_CHCTL_FLAGS) {
+			xpc_process_openclose_chctl_flags(part, ch_number,
+							chctl.flags[ch_number]);
+		}
 
 		ch_flags = ch->flags;	/* need an atomic snapshot of flags */
 
@@ -1299,7 +554,7 @@ xpc_process_channel_activity(struct xpc_partition *part)
 			continue;
 		}
 
-		if (part->act_state == XPC_P_DEACTIVATING)
+		if (part->act_state == XPC_P_AS_DEACTIVATING)
 			continue;
 
 		if (!(ch_flags & XPC_C_CONNECTED)) {
@@ -1315,13 +570,13 @@ xpc_process_channel_activity(struct xpc_partition *part)
 		}
 
 		/*
-		 * Process any message related IPI flags, this may involve the
-		 * activation of kthreads to deliver any pending messages sent
-		 * from the other partition.
+		 * Process any message related chctl flags, this may involve
+		 * the activation of kthreads to deliver any pending messages
+		 * sent from the other partition.
 		 */
 
-		if (XPC_ANY_MSG_IPI_FLAGS_SET(IPI_flags))
-			xpc_process_msg_IPI(part, ch_number);
+		if (chctl.flags[ch_number] & XPC_MSG_CHCTL_FLAGS)
+			xpc_process_msg_chctl_flags(part, ch_number);
 	}
 }
 
@@ -1369,59 +624,6 @@ xpc_partition_going_down(struct xpc_partition *part, enum xp_retval reason)
 }
 
 /*
- * Teardown the infrastructure necessary to support XPartition Communication
- * between the specified remote partition and the local one.
- */
-void
-xpc_teardown_infrastructure(struct xpc_partition *part)
-{
-	short partid = XPC_PARTID(part);
-
-	/*
-	 * We start off by making this partition inaccessible to local
-	 * processes by marking it as no longer setup. Then we make it
-	 * inaccessible to remote processes by clearing the XPC per partition
-	 * specific variable's magic # (which indicates that these variables
-	 * are no longer valid) and by ignoring all XPC notify IPIs sent to
-	 * this partition.
-	 */
-
-	DBUG_ON(atomic_read(&part->nchannels_engaged) != 0);
-	DBUG_ON(atomic_read(&part->nchannels_active) != 0);
-	DBUG_ON(part->setup_state != XPC_P_SETUP);
-	part->setup_state = XPC_P_WTEARDOWN;
-
-	xpc_vars_part[partid].magic = 0;
-
-	free_irq(SGI_XPC_NOTIFY, (void *)(u64)partid);
-
-	/*
-	 * Before proceeding with the teardown we have to wait until all
-	 * existing references cease.
-	 */
-	wait_event(part->teardown_wq, (atomic_read(&part->references) == 0));
-
-	/* now we can begin tearing down the infrastructure */
-
-	part->setup_state = XPC_P_TORNDOWN;
-
-	/* in case we've still got outstanding timers registered... */
-	del_timer_sync(&part->dropped_IPI_timer);
-
-	kfree(part->remote_openclose_args_base);
-	part->remote_openclose_args = NULL;
-	kfree(part->local_openclose_args_base);
-	part->local_openclose_args = NULL;
-	kfree(part->remote_GPs_base);
-	part->remote_GPs = NULL;
-	kfree(part->local_GPs_base);
-	part->local_GPs = NULL;
-	kfree(part->channels);
-	part->channels = NULL;
-	part->local_IPI_amo_va = NULL;
-}
-
-/*
  * Called by XP at the time of channel connection registration to cause
  * XPC to establish connections to all currently active partitions.
  */
@@ -1432,9 +634,9 @@ xpc_initiate_connect(int ch_number)
 	struct xpc_partition *part;
 	struct xpc_channel *ch;
 
-	DBUG_ON(ch_number < 0 || ch_number >= XPC_NCHANNELS);
+	DBUG_ON(ch_number < 0 || ch_number >= XPC_MAX_NCHANNELS);
 
-	for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) {
+	for (partid = 0; partid < xp_max_npartitions; partid++) {
 		part = &xpc_partitions[partid];
 
 		if (xpc_part_ref(part)) {
@@ -1488,10 +690,10 @@ xpc_initiate_disconnect(int ch_number)
 	struct xpc_partition *part;
 	struct xpc_channel *ch;
 
-	DBUG_ON(ch_number < 0 || ch_number >= XPC_NCHANNELS);
+	DBUG_ON(ch_number < 0 || ch_number >= XPC_MAX_NCHANNELS);
 
 	/* initiate the channel disconnect for every active partition */
-	for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) {
+	for (partid = 0; partid < xp_max_npartitions; partid++) {
 		part = &xpc_partitions[partid];
 
 		if (xpc_part_ref(part)) {
@@ -1550,7 +752,7 @@ xpc_disconnect_channel(const int line, struct xpc_channel *ch,
 		       XPC_C_ROPENREQUEST | XPC_C_ROPENREPLY |
 		       XPC_C_CONNECTING | XPC_C_CONNECTED);
 
-	xpc_IPI_send_closerequest(ch, irq_flags);
+	xpc_send_chctl_closerequest(ch, irq_flags);
 
 	if (channel_was_connected)
 		ch->flags |= XPC_C_WASCONNECTED;
@@ -1598,7 +800,7 @@ xpc_disconnect_callout(struct xpc_channel *ch, enum xp_retval reason)
  * Wait for a message entry to become available for the specified channel,
  * but don't wait any longer than 1 jiffy.
  */
-static enum xp_retval
+enum xp_retval
 xpc_allocate_msg_wait(struct xpc_channel *ch)
 {
 	enum xp_retval ret;
@@ -1625,315 +827,54 @@ xpc_allocate_msg_wait(struct xpc_channel *ch)
 }
 
 /*
- * Allocate an entry for a message from the message queue associated with the
- * specified channel.
- */
-static enum xp_retval
-xpc_allocate_msg(struct xpc_channel *ch, u32 flags,
-		 struct xpc_msg **address_of_msg)
-{
-	struct xpc_msg *msg;
-	enum xp_retval ret;
-	s64 put;
-
-	/* this reference will be dropped in xpc_send_msg() */
-	xpc_msgqueue_ref(ch);
-
-	if (ch->flags & XPC_C_DISCONNECTING) {
-		xpc_msgqueue_deref(ch);
-		return ch->reason;
-	}
-	if (!(ch->flags & XPC_C_CONNECTED)) {
-		xpc_msgqueue_deref(ch);
-		return xpNotConnected;
-	}
-
-	/*
-	 * Get the next available message entry from the local message queue.
-	 * If none are available, we'll make sure that we grab the latest
-	 * GP values.
-	 */
-	ret = xpTimeout;
-
-	while (1) {
-
-		put = ch->w_local_GP.put;
-		rmb();	/* guarantee that .put loads before .get */
-		if (put - ch->w_remote_GP.get < ch->local_nentries) {
-
-			/* There are available message entries. We need to try
-			 * to secure one for ourselves. We'll do this by trying
-			 * to increment w_local_GP.put as long as someone else
-			 * doesn't beat us to it. If they do, we'll have to
-			 * try again.
-			 */
-			if (cmpxchg(&ch->w_local_GP.put, put, put + 1) == put) {
-				/* we got the entry referenced by put */
-				break;
-			}
-			continue;	/* try again */
-		}
-
-		/*
-		 * There aren't any available msg entries at this time.
-		 *
-		 * In waiting for a message entry to become available,
-		 * we set a timeout in case the other side is not
-		 * sending completion IPIs. This lets us fake an IPI
-		 * that will cause the IPI handler to fetch the latest
-		 * GP values as if an IPI was sent by the other side.
-		 */
-		if (ret == xpTimeout)
-			xpc_IPI_send_local_msgrequest(ch);
-
-		if (flags & XPC_NOWAIT) {
-			xpc_msgqueue_deref(ch);
-			return xpNoWait;
-		}
-
-		ret = xpc_allocate_msg_wait(ch);
-		if (ret != xpInterrupted && ret != xpTimeout) {
-			xpc_msgqueue_deref(ch);
-			return ret;
-		}
-	}
-
-	/* get the message's address and initialize it */
-	msg = (struct xpc_msg *)((u64)ch->local_msgqueue +
-				 (put % ch->local_nentries) * ch->msg_size);
-
-	DBUG_ON(msg->flags != 0);
-	msg->number = put;
-
-	dev_dbg(xpc_chan, "w_local_GP.put changed to %ld; msg=0x%p, "
-		"msg_number=%ld, partid=%d, channel=%d\n", put + 1,
-		(void *)msg, msg->number, ch->partid, ch->number);
-
-	*address_of_msg = msg;
-
-	return xpSuccess;
-}
-
-/*
- * Allocate an entry for a message from the message queue associated with the
- * specified channel. NOTE that this routine can sleep waiting for a message
- * entry to become available. To not sleep, pass in the XPC_NOWAIT flag.
+ * Send a message that contains the user's payload on the specified channel
+ * connected to the specified partition.
  *
- * Arguments:
+ * NOTE that this routine can sleep waiting for a message entry to become
+ * available. To not sleep, pass in the XPC_NOWAIT flag.
  *
- *	partid - ID of partition to which the channel is connected.
- *	ch_number - channel #.
- *	flags - see xpc.h for valid flags.
- *	payload - address of the allocated payload area pointer (filled in on
- * 	          return) in which the user-defined message is constructed.
- */
-enum xp_retval
-xpc_initiate_allocate(short partid, int ch_number, u32 flags, void **payload)
-{
-	struct xpc_partition *part = &xpc_partitions[partid];
-	enum xp_retval ret = xpUnknownReason;
-	struct xpc_msg *msg = NULL;
-
-	DBUG_ON(partid <= 0 || partid >= XP_MAX_PARTITIONS);
-	DBUG_ON(ch_number < 0 || ch_number >= part->nchannels);
-
-	*payload = NULL;
-
-	if (xpc_part_ref(part)) {
-		ret = xpc_allocate_msg(&part->channels[ch_number], flags, &msg);
-		xpc_part_deref(part);
-
-		if (msg != NULL)
-			*payload = &msg->payload;
-	}
-
-	return ret;
-}
-
-/*
- * Now we actually send the messages that are ready to be sent by advancing
- * the local message queue's Put value and then send an IPI to the recipient
- * partition.
- */
-static void
-xpc_send_msgs(struct xpc_channel *ch, s64 initial_put)
-{
-	struct xpc_msg *msg;
-	s64 put = initial_put + 1;
-	int send_IPI = 0;
-
-	while (1) {
-
-		while (1) {
-			if (put == ch->w_local_GP.put)
-				break;
-
-			msg = (struct xpc_msg *)((u64)ch->local_msgqueue +
-						 (put % ch->local_nentries) *
-						 ch->msg_size);
-
-			if (!(msg->flags & XPC_M_READY))
-				break;
-
-			put++;
-		}
-
-		if (put == initial_put) {
-			/* nothing's changed */
-			break;
-		}
-
-		if (cmpxchg_rel(&ch->local_GP->put, initial_put, put) !=
-		    initial_put) {
-			/* someone else beat us to it */
-			DBUG_ON(ch->local_GP->put < initial_put);
-			break;
-		}
-
-		/* we just set the new value of local_GP->put */
-
-		dev_dbg(xpc_chan, "local_GP->put changed to %ld, partid=%d, "
-			"channel=%d\n", put, ch->partid, ch->number);
-
-		send_IPI = 1;
-
-		/*
-		 * We need to ensure that the message referenced by
-		 * local_GP->put is not XPC_M_READY or that local_GP->put
-		 * equals w_local_GP.put, so we'll go have a look.
-		 */
-		initial_put = put;
-	}
-
-	if (send_IPI)
-		xpc_IPI_send_msgrequest(ch);
-}
-
-/*
- * Common code that does the actual sending of the message by advancing the
- * local message queue's Put value and sends an IPI to the partition the
- * message is being sent to.
- */
-static enum xp_retval
-xpc_send_msg(struct xpc_channel *ch, struct xpc_msg *msg, u8 notify_type,
-	     xpc_notify_func func, void *key)
-{
-	enum xp_retval ret = xpSuccess;
-	struct xpc_notify *notify = notify;
-	s64 put, msg_number = msg->number;
-
-	DBUG_ON(notify_type == XPC_N_CALL && func == NULL);
-	DBUG_ON((((u64)msg - (u64)ch->local_msgqueue) / ch->msg_size) !=
-		msg_number % ch->local_nentries);
-	DBUG_ON(msg->flags & XPC_M_READY);
-
-	if (ch->flags & XPC_C_DISCONNECTING) {
-		/* drop the reference grabbed in xpc_allocate_msg() */
-		xpc_msgqueue_deref(ch);
-		return ch->reason;
-	}
-
-	if (notify_type != 0) {
-		/*
-		 * Tell the remote side to send an ACK interrupt when the
-		 * message has been delivered.
-		 */
-		msg->flags |= XPC_M_INTERRUPT;
-
-		atomic_inc(&ch->n_to_notify);
-
-		notify = &ch->notify_queue[msg_number % ch->local_nentries];
-		notify->func = func;
-		notify->key = key;
-		notify->type = notify_type;
-
-		/* >>> is a mb() needed here? */
-
-		if (ch->flags & XPC_C_DISCONNECTING) {
-			/*
-			 * An error occurred between our last error check and
-			 * this one. We will try to clear the type field from
-			 * the notify entry. If we succeed then
-			 * xpc_disconnect_channel() didn't already process
-			 * the notify entry.
-			 */
-			if (cmpxchg(&notify->type, notify_type, 0) ==
-			    notify_type) {
-				atomic_dec(&ch->n_to_notify);
-				ret = ch->reason;
-			}
-
-			/* drop the reference grabbed in xpc_allocate_msg() */
-			xpc_msgqueue_deref(ch);
-			return ret;
-		}
-	}
-
-	msg->flags |= XPC_M_READY;
-
-	/*
-	 * The preceding store of msg->flags must occur before the following
-	 * load of ch->local_GP->put.
-	 */
-	mb();
-
-	/* see if the message is next in line to be sent, if so send it */
-
-	put = ch->local_GP->put;
-	if (put == msg_number)
-		xpc_send_msgs(ch, put);
-
-	/* drop the reference grabbed in xpc_allocate_msg() */
-	xpc_msgqueue_deref(ch);
-	return ret;
-}
-
-/*
- * Send a message previously allocated using xpc_initiate_allocate() on the
- * specified channel connected to the specified partition.
- *
- * This routine will not wait for the message to be received, nor will
- * notification be given when it does happen. Once this routine has returned
- * the message entry allocated via xpc_initiate_allocate() is no longer
- * accessable to the caller.
- *
- * This routine, although called by users, does not call xpc_part_ref() to
- * ensure that the partition infrastructure is in place. It relies on the
- * fact that we called xpc_msgqueue_ref() in xpc_allocate_msg().
+ * Once sent, this routine will not wait for the message to be received, nor
+ * will notification be given when it does happen.
  *
  * Arguments:
  *
  *	partid - ID of partition to which the channel is connected.
  *	ch_number - channel # to send message on.
- *	payload - pointer to the payload area allocated via
- *			xpc_initiate_allocate().
+ *	flags - see xp.h for valid flags.
+ *	payload - pointer to the payload which is to be sent.
+ *	payload_size - size of the payload in bytes.
  */
 enum xp_retval
-xpc_initiate_send(short partid, int ch_number, void *payload)
+xpc_initiate_send(short partid, int ch_number, u32 flags, void *payload,
+		  u16 payload_size)
 {
 	struct xpc_partition *part = &xpc_partitions[partid];
-	struct xpc_msg *msg = XPC_MSG_ADDRESS(payload);
-	enum xp_retval ret;
+	enum xp_retval ret = xpUnknownReason;
 
-	dev_dbg(xpc_chan, "msg=0x%p, partid=%d, channel=%d\n", (void *)msg,
+	dev_dbg(xpc_chan, "payload=0x%p, partid=%d, channel=%d\n", payload,
 		partid, ch_number);
 
-	DBUG_ON(partid <= 0 || partid >= XP_MAX_PARTITIONS);
+	DBUG_ON(partid < 0 || partid >= xp_max_npartitions);
 	DBUG_ON(ch_number < 0 || ch_number >= part->nchannels);
-	DBUG_ON(msg == NULL);
+	DBUG_ON(payload == NULL);
 
-	ret = xpc_send_msg(&part->channels[ch_number], msg, 0, NULL, NULL);
+	if (xpc_part_ref(part)) {
+		ret = xpc_send_payload(&part->channels[ch_number], flags,
+				       payload, payload_size, 0, NULL, NULL);
+		xpc_part_deref(part);
+	}
 
 	return ret;
 }
 
 /*
- * Send a message previously allocated using xpc_initiate_allocate on the
- * specified channel connected to the specified partition.
+ * Send a message that contains the user's payload on the specified channel
+ * connected to the specified partition.
  *
- * This routine will not wait for the message to be sent. Once this routine
- * has returned the message entry allocated via xpc_initiate_allocate() is no
- * longer accessable to the caller.
+ * NOTE that this routine can sleep waiting for a message entry to become
+ * available. To not sleep, pass in the XPC_NOWAIT flag.
+ *
+ * This routine will not wait for the message to be sent or received.
  *
  * Once the remote end of the channel has received the message, the function
  * passed as an argument to xpc_initiate_send_notify() will be called. This
@@ -1943,158 +884,51 @@ xpc_initiate_send(short partid, int ch_number, void *payload)
  *
  * If this routine returns an error, the caller's function will NOT be called.
  *
- * This routine, although called by users, does not call xpc_part_ref() to
- * ensure that the partition infrastructure is in place. It relies on the
- * fact that we called xpc_msgqueue_ref() in xpc_allocate_msg().
- *
  * Arguments:
  *
  *	partid - ID of partition to which the channel is connected.
  *	ch_number - channel # to send message on.
- *	payload - pointer to the payload area allocated via
- *			xpc_initiate_allocate().
+ *	flags - see xp.h for valid flags.
+ *	payload - pointer to the payload which is to be sent.
+ *	payload_size - size of the payload in bytes.
  *	func - function to call with asynchronous notification of message
  *		  receipt. THIS FUNCTION MUST BE NON-BLOCKING.
  *	key - user-defined key to be passed to the function when it's called.
  */
 enum xp_retval
-xpc_initiate_send_notify(short partid, int ch_number, void *payload,
-			 xpc_notify_func func, void *key)
+xpc_initiate_send_notify(short partid, int ch_number, u32 flags, void *payload,
+			 u16 payload_size, xpc_notify_func func, void *key)
 {
 	struct xpc_partition *part = &xpc_partitions[partid];
-	struct xpc_msg *msg = XPC_MSG_ADDRESS(payload);
-	enum xp_retval ret;
+	enum xp_retval ret = xpUnknownReason;
 
-	dev_dbg(xpc_chan, "msg=0x%p, partid=%d, channel=%d\n", (void *)msg,
+	dev_dbg(xpc_chan, "payload=0x%p, partid=%d, channel=%d\n", payload,
 		partid, ch_number);
 
-	DBUG_ON(partid <= 0 || partid >= XP_MAX_PARTITIONS);
+	DBUG_ON(partid < 0 || partid >= xp_max_npartitions);
 	DBUG_ON(ch_number < 0 || ch_number >= part->nchannels);
-	DBUG_ON(msg == NULL);
+	DBUG_ON(payload == NULL);
 	DBUG_ON(func == NULL);
 
-	ret = xpc_send_msg(&part->channels[ch_number], msg, XPC_N_CALL,
-			   func, key);
-	return ret;
-}
-
-static struct xpc_msg *
-xpc_pull_remote_msg(struct xpc_channel *ch, s64 get)
-{
-	struct xpc_partition *part = &xpc_partitions[ch->partid];
-	struct xpc_msg *remote_msg, *msg;
-	u32 msg_index, nmsgs;
-	u64 msg_offset;
-	enum xp_retval ret;
-
-	if (mutex_lock_interruptible(&ch->msg_to_pull_mutex) != 0) {
-		/* we were interrupted by a signal */
-		return NULL;
-	}
-
-	while (get >= ch->next_msg_to_pull) {
-
-		/* pull as many messages as are ready and able to be pulled */
-
-		msg_index = ch->next_msg_to_pull % ch->remote_nentries;
-
-		DBUG_ON(ch->next_msg_to_pull >= ch->w_remote_GP.put);
-		nmsgs = ch->w_remote_GP.put - ch->next_msg_to_pull;
-		if (msg_index + nmsgs > ch->remote_nentries) {
-			/* ignore the ones that wrap the msg queue for now */
-			nmsgs = ch->remote_nentries - msg_index;
-		}
-
-		msg_offset = msg_index * ch->msg_size;
-		msg = (struct xpc_msg *)((u64)ch->remote_msgqueue + msg_offset);
-		remote_msg = (struct xpc_msg *)(ch->remote_msgqueue_pa +
-						msg_offset);
-
-		ret = xpc_pull_remote_cachelines(part, msg, remote_msg,
-						 nmsgs * ch->msg_size);
-		if (ret != xpSuccess) {
-
-			dev_dbg(xpc_chan, "failed to pull %d msgs starting with"
-				" msg %ld from partition %d, channel=%d, "
-				"ret=%d\n", nmsgs, ch->next_msg_to_pull,
-				ch->partid, ch->number, ret);
-
-			XPC_DEACTIVATE_PARTITION(part, ret);
-
-			mutex_unlock(&ch->msg_to_pull_mutex);
-			return NULL;
-		}
-
-		ch->next_msg_to_pull += nmsgs;
+	if (xpc_part_ref(part)) {
+		ret = xpc_send_payload(&part->channels[ch_number], flags,
+				       payload, payload_size, XPC_N_CALL, func,
+				       key);
+		xpc_part_deref(part);
 	}
-
-	mutex_unlock(&ch->msg_to_pull_mutex);
-
-	/* return the message we were looking for */
-	msg_offset = (get % ch->remote_nentries) * ch->msg_size;
-	msg = (struct xpc_msg *)((u64)ch->remote_msgqueue + msg_offset);
-
-	return msg;
-}
-
-/*
- * Get a message to be delivered.
- */
-static struct xpc_msg *
-xpc_get_deliverable_msg(struct xpc_channel *ch)
-{
-	struct xpc_msg *msg = NULL;
-	s64 get;
-
-	do {
-		if (ch->flags & XPC_C_DISCONNECTING)
-			break;
-
-		get = ch->w_local_GP.get;
-		rmb();	/* guarantee that .get loads before .put */
-		if (get == ch->w_remote_GP.put)
-			break;
-
-		/* There are messages waiting to be pulled and delivered.
-		 * We need to try to secure one for ourselves. We'll do this
-		 * by trying to increment w_local_GP.get and hope that no one
-		 * else beats us to it. If they do, we'll we'll simply have
-		 * to try again for the next one.
-		 */
-
-		if (cmpxchg(&ch->w_local_GP.get, get, get + 1) == get) {
-			/* we got the entry referenced by get */
-
-			dev_dbg(xpc_chan, "w_local_GP.get changed to %ld, "
-				"partid=%d, channel=%d\n", get + 1,
-				ch->partid, ch->number);
-
-			/* pull the message from the remote partition */
-
-			msg = xpc_pull_remote_msg(ch, get);
-
-			DBUG_ON(msg != NULL && msg->number != get);
-			DBUG_ON(msg != NULL && (msg->flags & XPC_M_DONE));
-			DBUG_ON(msg != NULL && !(msg->flags & XPC_M_READY));
-
-			break;
-		}
-
-	} while (1);
-
-	return msg;
+	return ret;
 }
 
 /*
- * Deliver a message to its intended recipient.
+ * Deliver a message's payload to its intended recipient.
  */
 void
-xpc_deliver_msg(struct xpc_channel *ch)
+xpc_deliver_payload(struct xpc_channel *ch)
 {
-	struct xpc_msg *msg;
+	void *payload;
 
-	msg = xpc_get_deliverable_msg(ch);
-	if (msg != NULL) {
+	payload = xpc_get_deliverable_payload(ch);
+	if (payload != NULL) {
 
 		/*
 		 * This ref is taken to protect the payload itself from being
@@ -2106,18 +940,16 @@ xpc_deliver_msg(struct xpc_channel *ch)
 		atomic_inc(&ch->kthreads_active);
 
 		if (ch->func != NULL) {
-			dev_dbg(xpc_chan, "ch->func() called, msg=0x%p, "
-				"msg_number=%ld, partid=%d, channel=%d\n",
-				(void *)msg, msg->number, ch->partid,
+			dev_dbg(xpc_chan, "ch->func() called, payload=0x%p "
+				"partid=%d channel=%d\n", payload, ch->partid,
 				ch->number);
 
 			/* deliver the message to its intended recipient */
-			ch->func(xpMsgReceived, ch->partid, ch->number,
-				 &msg->payload, ch->key);
+			ch->func(xpMsgReceived, ch->partid, ch->number, payload,
+				 ch->key);
 
-			dev_dbg(xpc_chan, "ch->func() returned, msg=0x%p, "
-				"msg_number=%ld, partid=%d, channel=%d\n",
-				(void *)msg, msg->number, ch->partid,
+			dev_dbg(xpc_chan, "ch->func() returned, payload=0x%p "
+				"partid=%d channel=%d\n", payload, ch->partid,
 				ch->number);
 		}
 
@@ -2126,118 +958,31 @@ xpc_deliver_msg(struct xpc_channel *ch)
 }
 
 /*
- * Now we actually acknowledge the messages that have been delivered and ack'd
- * by advancing the cached remote message queue's Get value and if requested
- * send an IPI to the message sender's partition.
- */
-static void
-xpc_acknowledge_msgs(struct xpc_channel *ch, s64 initial_get, u8 msg_flags)
-{
-	struct xpc_msg *msg;
-	s64 get = initial_get + 1;
-	int send_IPI = 0;
-
-	while (1) {
-
-		while (1) {
-			if (get == ch->w_local_GP.get)
-				break;
-
-			msg = (struct xpc_msg *)((u64)ch->remote_msgqueue +
-						 (get % ch->remote_nentries) *
-						 ch->msg_size);
-
-			if (!(msg->flags & XPC_M_DONE))
-				break;
-
-			msg_flags |= msg->flags;
-			get++;
-		}
-
-		if (get == initial_get) {
-			/* nothing's changed */
-			break;
-		}
-
-		if (cmpxchg_rel(&ch->local_GP->get, initial_get, get) !=
-		    initial_get) {
-			/* someone else beat us to it */
-			DBUG_ON(ch->local_GP->get <= initial_get);
-			break;
-		}
-
-		/* we just set the new value of local_GP->get */
-
-		dev_dbg(xpc_chan, "local_GP->get changed to %ld, partid=%d, "
-			"channel=%d\n", get, ch->partid, ch->number);
-
-		send_IPI = (msg_flags & XPC_M_INTERRUPT);
-
-		/*
-		 * We need to ensure that the message referenced by
-		 * local_GP->get is not XPC_M_DONE or that local_GP->get
-		 * equals w_local_GP.get, so we'll go have a look.
-		 */
-		initial_get = get;
-	}
-
-	if (send_IPI)
-		xpc_IPI_send_msgrequest(ch);
-}
-
-/*
- * Acknowledge receipt of a delivered message.
- *
- * If a message has XPC_M_INTERRUPT set, send an interrupt to the partition
- * that sent the message.
+ * Acknowledge receipt of a delivered message's payload.
  *
  * This function, although called by users, does not call xpc_part_ref() to
  * ensure that the partition infrastructure is in place. It relies on the
- * fact that we called xpc_msgqueue_ref() in xpc_deliver_msg().
+ * fact that we called xpc_msgqueue_ref() in xpc_deliver_payload().
  *
  * Arguments:
  *
  *	partid - ID of partition to which the channel is connected.
  *	ch_number - channel # message received on.
  *	payload - pointer to the payload area allocated via
- *			xpc_initiate_allocate().
+ *			xpc_initiate_send() or xpc_initiate_send_notify().
  */
 void
 xpc_initiate_received(short partid, int ch_number, void *payload)
 {
 	struct xpc_partition *part = &xpc_partitions[partid];
 	struct xpc_channel *ch;
-	struct xpc_msg *msg = XPC_MSG_ADDRESS(payload);
-	s64 get, msg_number = msg->number;
 
-	DBUG_ON(partid <= 0 || partid >= XP_MAX_PARTITIONS);
+	DBUG_ON(partid < 0 || partid >= xp_max_npartitions);
 	DBUG_ON(ch_number < 0 || ch_number >= part->nchannels);
 
 	ch = &part->channels[ch_number];
+	xpc_received_payload(ch, payload);
 
-	dev_dbg(xpc_chan, "msg=0x%p, msg_number=%ld, partid=%d, channel=%d\n",
-		(void *)msg, msg_number, ch->partid, ch->number);
-
-	DBUG_ON((((u64)msg - (u64)ch->remote_msgqueue) / ch->msg_size) !=
-		msg_number % ch->remote_nentries);
-	DBUG_ON(msg->flags & XPC_M_DONE);
-
-	msg->flags |= XPC_M_DONE;
-
-	/*
-	 * The preceding store of msg->flags must occur before the following
-	 * load of ch->local_GP->get.
-	 */
-	mb();
-
-	/*
-	 * See if this message is next in line to be acknowledged as having
-	 * been delivered.
-	 */
-	get = ch->local_GP->get;
-	if (get == msg_number)
-		xpc_acknowledge_msgs(ch, get, msg->flags);
-
-	/* the call to xpc_msgqueue_ref() was done by xpc_deliver_msg()  */
+	/* the call to xpc_msgqueue_ref() was done by xpc_deliver_payload()  */
 	xpc_msgqueue_deref(ch);
 }
diff --git a/drivers/misc/sgi-xp/xpc_main.c b/drivers/misc/sgi-xp/xpc_main.c
index 08256ed0d9a..46325fc8481 100644
--- a/drivers/misc/sgi-xp/xpc_main.c
+++ b/drivers/misc/sgi-xp/xpc_main.c
@@ -25,37 +25,31 @@
  *
  *	Caveats:
  *
- *	  . We currently have no way to determine which nasid an IPI came
- *	    from. Thus, xpc_IPI_send() does a remote AMO write followed by
- *	    an IPI. The AMO indicates where data is to be pulled from, so
- *	    after the IPI arrives, the remote partition checks the AMO word.
- *	    The IPI can actually arrive before the AMO however, so other code
- *	    must periodically check for this case. Also, remote AMO operations
- *	    do not reliably time out. Thus we do a remote PIO read solely to
- *	    know whether the remote partition is down and whether we should
- *	    stop sending IPIs to it. This remote PIO read operation is set up
- *	    in a special nofault region so SAL knows to ignore (and cleanup)
- *	    any errors due to the remote AMO write, PIO read, and/or PIO
- *	    write operations.
+ *	  . Currently on sn2, we have no way to determine which nasid an IRQ
+ *	    came from. Thus, xpc_send_IRQ_sn2() does a remote amo write
+ *	    followed by an IPI. The amo indicates where data is to be pulled
+ *	    from, so after the IPI arrives, the remote partition checks the amo
+ *	    word. The IPI can actually arrive before the amo however, so other
+ *	    code must periodically check for this case. Also, remote amo
+ *	    operations do not reliably time out. Thus we do a remote PIO read
+ *	    solely to know whether the remote partition is down and whether we
+ *	    should stop sending IPIs to it. This remote PIO read operation is
+ *	    set up in a special nofault region so SAL knows to ignore (and
+ *	    cleanup) any errors due to the remote amo write, PIO read, and/or
+ *	    PIO write operations.
  *
  *	    If/when new hardware solves this IPI problem, we should abandon
  *	    the current approach.
  *
  */
 
-#include <linux/kernel.h>
 #include <linux/module.h>
-#include <linux/init.h>
-#include <linux/cache.h>
-#include <linux/interrupt.h>
+#include <linux/sysctl.h>
+#include <linux/device.h>
 #include <linux/delay.h>
 #include <linux/reboot.h>
-#include <linux/completion.h>
 #include <linux/kdebug.h>
 #include <linux/kthread.h>
-#include <linux/uaccess.h>
-#include <asm/sn/intr.h>
-#include <asm/sn/sn_sal.h>
 #include "xpc.h"
 
 /* define two XPC debug device structures to be used with dev_dbg() et al */
@@ -89,9 +83,9 @@ static int xpc_hb_check_interval = XPC_HB_CHECK_DEFAULT_INTERVAL;
 static int xpc_hb_check_min_interval = 10;
 static int xpc_hb_check_max_interval = 120;
 
-int xpc_disengage_request_timelimit = XPC_DISENGAGE_REQUEST_DEFAULT_TIMELIMIT;
-static int xpc_disengage_request_min_timelimit;	/* = 0 */
-static int xpc_disengage_request_max_timelimit = 120;
+int xpc_disengage_timelimit = XPC_DISENGAGE_DEFAULT_TIMELIMIT;
+static int xpc_disengage_min_timelimit;	/* = 0 */
+static int xpc_disengage_max_timelimit = 120;
 
 static ctl_table xpc_sys_xpc_hb_dir[] = {
 	{
@@ -124,14 +118,14 @@ static ctl_table xpc_sys_xpc_dir[] = {
 	 .child = xpc_sys_xpc_hb_dir},
 	{
 	 .ctl_name = CTL_UNNUMBERED,
-	 .procname = "disengage_request_timelimit",
-	 .data = &xpc_disengage_request_timelimit,
+	 .procname = "disengage_timelimit",
+	 .data = &xpc_disengage_timelimit,
 	 .maxlen = sizeof(int),
 	 .mode = 0644,
 	 .proc_handler = &proc_dointvec_minmax,
 	 .strategy = &sysctl_intvec,
-	 .extra1 = &xpc_disengage_request_min_timelimit,
-	 .extra2 = &xpc_disengage_request_max_timelimit},
+	 .extra1 = &xpc_disengage_min_timelimit,
+	 .extra2 = &xpc_disengage_max_timelimit},
 	{}
 };
 static ctl_table xpc_sys_dir[] = {
@@ -144,16 +138,19 @@ static ctl_table xpc_sys_dir[] = {
 };
 static struct ctl_table_header *xpc_sysctl;
 
-/* non-zero if any remote partition disengage request was timed out */
-int xpc_disengage_request_timedout;
+/* non-zero if any remote partition disengage was timed out */
+int xpc_disengage_timedout;
 
-/* #of IRQs received */
-static atomic_t xpc_act_IRQ_rcvd;
+/* #of activate IRQs received and not yet processed */
+int xpc_activate_IRQ_rcvd;
+DEFINE_SPINLOCK(xpc_activate_IRQ_rcvd_lock);
 
 /* IRQ handler notifies this wait queue on receipt of an IRQ */
-static DECLARE_WAIT_QUEUE_HEAD(xpc_act_IRQ_wq);
+DECLARE_WAIT_QUEUE_HEAD(xpc_activate_IRQ_wq);
 
 static unsigned long xpc_hb_check_timeout;
+static struct timer_list xpc_hb_timer;
+void *xpc_heartbeating_to_mask;
 
 /* notification that the xpc_hb_checker thread has exited */
 static DECLARE_COMPLETION(xpc_hb_checker_exited);
@@ -161,8 +158,6 @@ static DECLARE_COMPLETION(xpc_hb_checker_exited);
 /* notification that the xpc_discovery thread has exited */
 static DECLARE_COMPLETION(xpc_discovery_exited);
 
-static struct timer_list xpc_hb_timer;
-
 static void xpc_kthread_waitmsgs(struct xpc_partition *, struct xpc_channel *);
 
 static int xpc_system_reboot(struct notifier_block *, unsigned long, void *);
@@ -175,31 +170,76 @@ static struct notifier_block xpc_die_notifier = {
 	.notifier_call = xpc_system_die,
 };
 
+int (*xpc_setup_partitions_sn) (void);
+enum xp_retval (*xpc_get_partition_rsvd_page_pa) (void *buf, u64 *cookie,
+						  unsigned long *rp_pa,
+						  size_t *len);
+int (*xpc_setup_rsvd_page_sn) (struct xpc_rsvd_page *rp);
+void (*xpc_heartbeat_init) (void);
+void (*xpc_heartbeat_exit) (void);
+void (*xpc_increment_heartbeat) (void);
+void (*xpc_offline_heartbeat) (void);
+void (*xpc_online_heartbeat) (void);
+enum xp_retval (*xpc_get_remote_heartbeat) (struct xpc_partition *part);
+
+enum xp_retval (*xpc_make_first_contact) (struct xpc_partition *part);
+void (*xpc_notify_senders_of_disconnect) (struct xpc_channel *ch);
+u64 (*xpc_get_chctl_all_flags) (struct xpc_partition *part);
+enum xp_retval (*xpc_setup_msg_structures) (struct xpc_channel *ch);
+void (*xpc_teardown_msg_structures) (struct xpc_channel *ch);
+void (*xpc_process_msg_chctl_flags) (struct xpc_partition *part, int ch_number);
+int (*xpc_n_of_deliverable_payloads) (struct xpc_channel *ch);
+void *(*xpc_get_deliverable_payload) (struct xpc_channel *ch);
+
+void (*xpc_request_partition_activation) (struct xpc_rsvd_page *remote_rp,
+					  unsigned long remote_rp_pa,
+					  int nasid);
+void (*xpc_request_partition_reactivation) (struct xpc_partition *part);
+void (*xpc_request_partition_deactivation) (struct xpc_partition *part);
+void (*xpc_cancel_partition_deactivation_request) (struct xpc_partition *part);
+
+void (*xpc_process_activate_IRQ_rcvd) (void);
+enum xp_retval (*xpc_setup_ch_structures_sn) (struct xpc_partition *part);
+void (*xpc_teardown_ch_structures_sn) (struct xpc_partition *part);
+
+void (*xpc_indicate_partition_engaged) (struct xpc_partition *part);
+int (*xpc_partition_engaged) (short partid);
+int (*xpc_any_partition_engaged) (void);
+void (*xpc_indicate_partition_disengaged) (struct xpc_partition *part);
+void (*xpc_assume_partition_disengaged) (short partid);
+
+void (*xpc_send_chctl_closerequest) (struct xpc_channel *ch,
+				     unsigned long *irq_flags);
+void (*xpc_send_chctl_closereply) (struct xpc_channel *ch,
+				   unsigned long *irq_flags);
+void (*xpc_send_chctl_openrequest) (struct xpc_channel *ch,
+				    unsigned long *irq_flags);
+void (*xpc_send_chctl_openreply) (struct xpc_channel *ch,
+				  unsigned long *irq_flags);
+
+void (*xpc_save_remote_msgqueue_pa) (struct xpc_channel *ch,
+				     unsigned long msgqueue_pa);
+
+enum xp_retval (*xpc_send_payload) (struct xpc_channel *ch, u32 flags,
+				    void *payload, u16 payload_size,
+				    u8 notify_type, xpc_notify_func func,
+				    void *key);
+void (*xpc_received_payload) (struct xpc_channel *ch, void *payload);
+
 /*
- * Timer function to enforce the timelimit on the partition disengage request.
+ * Timer function to enforce the timelimit on the partition disengage.
  */
 static void
-xpc_timeout_partition_disengage_request(unsigned long data)
+xpc_timeout_partition_disengage(unsigned long data)
 {
 	struct xpc_partition *part = (struct xpc_partition *)data;
 
-	DBUG_ON(time_before(jiffies, part->disengage_request_timeout));
+	DBUG_ON(time_is_after_jiffies(part->disengage_timeout));
 
 	(void)xpc_partition_disengaged(part);
 
-	DBUG_ON(part->disengage_request_timeout != 0);
-	DBUG_ON(xpc_partition_engaged(1UL << XPC_PARTID(part)) != 0);
-}
-
-/*
- * Notify the heartbeat check thread that an IRQ has been received.
- */
-static irqreturn_t
-xpc_act_IRQ_handler(int irq, void *dev_id)
-{
-	atomic_inc(&xpc_act_IRQ_rcvd);
-	wake_up_interruptible(&xpc_act_IRQ_wq);
-	return IRQ_HANDLED;
+	DBUG_ON(part->disengage_timeout != 0);
+	DBUG_ON(xpc_partition_engaged(XPC_PARTID(part)));
 }
 
 /*
@@ -210,15 +250,63 @@ xpc_act_IRQ_handler(int irq, void *dev_id)
 static void
 xpc_hb_beater(unsigned long dummy)
 {
-	xpc_vars->heartbeat++;
+	xpc_increment_heartbeat();
 
-	if (time_after_eq(jiffies, xpc_hb_check_timeout))
-		wake_up_interruptible(&xpc_act_IRQ_wq);
+	if (time_is_before_eq_jiffies(xpc_hb_check_timeout))
+		wake_up_interruptible(&xpc_activate_IRQ_wq);
 
 	xpc_hb_timer.expires = jiffies + (xpc_hb_interval * HZ);
 	add_timer(&xpc_hb_timer);
 }
 
+static void
+xpc_start_hb_beater(void)
+{
+	xpc_heartbeat_init();
+	init_timer(&xpc_hb_timer);
+	xpc_hb_timer.function = xpc_hb_beater;
+	xpc_hb_beater(0);
+}
+
+static void
+xpc_stop_hb_beater(void)
+{
+	del_timer_sync(&xpc_hb_timer);
+	xpc_heartbeat_exit();
+}
+
+/*
+ * At periodic intervals, scan through all active partitions and ensure
+ * their heartbeat is still active.  If not, the partition is deactivated.
+ */
+static void
+xpc_check_remote_hb(void)
+{
+	struct xpc_partition *part;
+	short partid;
+	enum xp_retval ret;
+
+	for (partid = 0; partid < xp_max_npartitions; partid++) {
+
+		if (xpc_exiting)
+			break;
+
+		if (partid == xp_partition_id)
+			continue;
+
+		part = &xpc_partitions[partid];
+
+		if (part->act_state == XPC_P_AS_INACTIVE ||
+		    part->act_state == XPC_P_AS_DEACTIVATING) {
+			continue;
+		}
+
+		ret = xpc_get_remote_heartbeat(part);
+		if (ret != xpSuccess)
+			XPC_DEACTIVATE_PARTITION(part, ret);
+	}
+}
+
 /*
  * This thread is responsible for nearly all of the partition
  * activation/deactivation.
@@ -226,66 +314,57 @@ xpc_hb_beater(unsigned long dummy)
 static int
 xpc_hb_checker(void *ignore)
 {
-	int last_IRQ_count = 0;
-	int new_IRQ_count;
 	int force_IRQ = 0;
 
 	/* this thread was marked active by xpc_hb_init() */
 
-	set_cpus_allowed(current, cpumask_of_cpu(XPC_HB_CHECK_CPU));
+	set_cpus_allowed_ptr(current, &cpumask_of_cpu(XPC_HB_CHECK_CPU));
 
 	/* set our heartbeating to other partitions into motion */
 	xpc_hb_check_timeout = jiffies + (xpc_hb_check_interval * HZ);
-	xpc_hb_beater(0);
+	xpc_start_hb_beater();
 
 	while (!xpc_exiting) {
 
 		dev_dbg(xpc_part, "woke up with %d ticks rem; %d IRQs have "
 			"been received\n",
 			(int)(xpc_hb_check_timeout - jiffies),
-			atomic_read(&xpc_act_IRQ_rcvd) - last_IRQ_count);
+			xpc_activate_IRQ_rcvd);
 
 		/* checking of remote heartbeats is skewed by IRQ handling */
-		if (time_after_eq(jiffies, xpc_hb_check_timeout)) {
+		if (time_is_before_eq_jiffies(xpc_hb_check_timeout)) {
+			xpc_hb_check_timeout = jiffies +
+			    (xpc_hb_check_interval * HZ);
+
 			dev_dbg(xpc_part, "checking remote heartbeats\n");
 			xpc_check_remote_hb();
 
 			/*
-			 * We need to periodically recheck to ensure no
-			 * IPI/AMO pairs have been missed.  That check
-			 * must always reset xpc_hb_check_timeout.
+			 * On sn2 we need to periodically recheck to ensure no
+			 * IRQ/amo pairs have been missed.
 			 */
-			force_IRQ = 1;
+			if (is_shub())
+				force_IRQ = 1;
 		}
 
 		/* check for outstanding IRQs */
-		new_IRQ_count = atomic_read(&xpc_act_IRQ_rcvd);
-		if (last_IRQ_count < new_IRQ_count || force_IRQ != 0) {
+		if (xpc_activate_IRQ_rcvd > 0 || force_IRQ != 0) {
 			force_IRQ = 0;
-
-			dev_dbg(xpc_part, "found an IRQ to process; will be "
-				"resetting xpc_hb_check_timeout\n");
-
-			last_IRQ_count += xpc_identify_act_IRQ_sender();
-			if (last_IRQ_count < new_IRQ_count) {
-				/* retry once to help avoid missing AMO */
-				(void)xpc_identify_act_IRQ_sender();
-			}
-			last_IRQ_count = new_IRQ_count;
-
-			xpc_hb_check_timeout = jiffies +
-			    (xpc_hb_check_interval * HZ);
+			dev_dbg(xpc_part, "processing activate IRQs "
+				"received\n");
+			xpc_process_activate_IRQ_rcvd();
 		}
 
 		/* wait for IRQ or timeout */
-		(void)wait_event_interruptible(xpc_act_IRQ_wq,
-					       (last_IRQ_count <
-						atomic_read(&xpc_act_IRQ_rcvd)
-						|| time_after_eq(jiffies,
-							xpc_hb_check_timeout) ||
+		(void)wait_event_interruptible(xpc_activate_IRQ_wq,
+					       (time_is_before_eq_jiffies(
+						xpc_hb_check_timeout) ||
+						xpc_activate_IRQ_rcvd > 0 ||
 						xpc_exiting));
 	}
 
+	xpc_stop_hb_beater();
+
 	dev_dbg(xpc_part, "heartbeat checker is exiting\n");
 
 	/* mark this thread as having exited */
@@ -311,37 +390,8 @@ xpc_initiate_discovery(void *ignore)
 }
 
 /*
- * Establish first contact with the remote partititon. This involves pulling
- * the XPC per partition variables from the remote partition and waiting for
- * the remote partition to pull ours.
- */
-static enum xp_retval
-xpc_make_first_contact(struct xpc_partition *part)
-{
-	enum xp_retval ret;
-
-	while ((ret = xpc_pull_remote_vars_part(part)) != xpSuccess) {
-		if (ret != xpRetry) {
-			XPC_DEACTIVATE_PARTITION(part, ret);
-			return ret;
-		}
-
-		dev_dbg(xpc_chan, "waiting to make first contact with "
-			"partition %d\n", XPC_PARTID(part));
-
-		/* wait a 1/4 of a second or so */
-		(void)msleep_interruptible(250);
-
-		if (part->act_state == XPC_P_DEACTIVATING)
-			return part->reason;
-	}
-
-	return xpc_mark_partition_active(part);
-}
-
-/*
  * The first kthread assigned to a newly activated partition is the one
- * created by XPC HB with which it calls xpc_partition_up(). XPC hangs on to
+ * created by XPC HB with which it calls xpc_activating(). XPC hangs on to
  * that kthread until the partition is brought down, at which time that kthread
  * returns back to XPC HB. (The return of that kthread will signify to XPC HB
  * that XPC has dismantled all communication infrastructure for the associated
@@ -354,11 +404,11 @@ xpc_make_first_contact(struct xpc_partition *part)
 static void
 xpc_channel_mgr(struct xpc_partition *part)
 {
-	while (part->act_state != XPC_P_DEACTIVATING ||
+	while (part->act_state != XPC_P_AS_DEACTIVATING ||
 	       atomic_read(&part->nchannels_active) > 0 ||
 	       !xpc_partition_disengaged(part)) {
 
-		xpc_process_channel_activity(part);
+		xpc_process_sent_chctl_flags(part);
 
 		/*
 		 * Wait until we've been requested to activate kthreads or
@@ -376,8 +426,8 @@ xpc_channel_mgr(struct xpc_partition *part)
 		atomic_dec(&part->channel_mgr_requests);
 		(void)wait_event_interruptible(part->channel_mgr_wq,
 				(atomic_read(&part->channel_mgr_requests) > 0 ||
-				 part->local_IPI_amo != 0 ||
-				 (part->act_state == XPC_P_DEACTIVATING &&
+				 part->chctl.all_flags != 0 ||
+				 (part->act_state == XPC_P_AS_DEACTIVATING &&
 				 atomic_read(&part->nchannels_active) == 0 &&
 				 xpc_partition_disengaged(part))));
 		atomic_set(&part->channel_mgr_requests, 1);
@@ -385,47 +435,163 @@ xpc_channel_mgr(struct xpc_partition *part)
 }
 
 /*
- * When XPC HB determines that a partition has come up, it will create a new
- * kthread and that kthread will call this function to attempt to set up the
- * basic infrastructure used for Cross Partition Communication with the newly
- * upped partition.
- *
- * The kthread that was created by XPC HB and which setup the XPC
- * infrastructure will remain assigned to the partition until the partition
- * goes down. At which time the kthread will teardown the XPC infrastructure
- * and then exit.
- *
- * XPC HB will put the remote partition's XPC per partition specific variables
- * physical address into xpc_partitions[partid].remote_vars_part_pa prior to
- * calling xpc_partition_up().
+ * Guarantee that the kzalloc'd memory is cacheline aligned.
  */
-static void
-xpc_partition_up(struct xpc_partition *part)
+void *
+xpc_kzalloc_cacheline_aligned(size_t size, gfp_t flags, void **base)
+{
+	/* see if kzalloc will give us cachline aligned memory by default */
+	*base = kzalloc(size, flags);
+	if (*base == NULL)
+		return NULL;
+
+	if ((u64)*base == L1_CACHE_ALIGN((u64)*base))
+		return *base;
+
+	kfree(*base);
+
+	/* nope, we'll have to do it ourselves */
+	*base = kzalloc(size + L1_CACHE_BYTES, flags);
+	if (*base == NULL)
+		return NULL;
+
+	return (void *)L1_CACHE_ALIGN((u64)*base);
+}
+
+/*
+ * Setup the channel structures necessary to support XPartition Communication
+ * between the specified remote partition and the local one.
+ */
+static enum xp_retval
+xpc_setup_ch_structures(struct xpc_partition *part)
 {
+	enum xp_retval ret;
+	int ch_number;
+	struct xpc_channel *ch;
+	short partid = XPC_PARTID(part);
+
+	/*
+	 * Allocate all of the channel structures as a contiguous chunk of
+	 * memory.
+	 */
 	DBUG_ON(part->channels != NULL);
+	part->channels = kzalloc(sizeof(struct xpc_channel) * XPC_MAX_NCHANNELS,
+				 GFP_KERNEL);
+	if (part->channels == NULL) {
+		dev_err(xpc_chan, "can't get memory for channels\n");
+		return xpNoMemory;
+	}
 
-	dev_dbg(xpc_chan, "activating partition %d\n", XPC_PARTID(part));
+	/* allocate the remote open and close args */
 
-	if (xpc_setup_infrastructure(part) != xpSuccess)
-		return;
+	part->remote_openclose_args =
+	    xpc_kzalloc_cacheline_aligned(XPC_OPENCLOSE_ARGS_SIZE,
+					  GFP_KERNEL, &part->
+					  remote_openclose_args_base);
+	if (part->remote_openclose_args == NULL) {
+		dev_err(xpc_chan, "can't get memory for remote connect args\n");
+		ret = xpNoMemory;
+		goto out_1;
+	}
+
+	part->chctl.all_flags = 0;
+	spin_lock_init(&part->chctl_lock);
+
+	atomic_set(&part->channel_mgr_requests, 1);
+	init_waitqueue_head(&part->channel_mgr_wq);
+
+	part->nchannels = XPC_MAX_NCHANNELS;
+
+	atomic_set(&part->nchannels_active, 0);
+	atomic_set(&part->nchannels_engaged, 0);
+
+	for (ch_number = 0; ch_number < part->nchannels; ch_number++) {
+		ch = &part->channels[ch_number];
+
+		ch->partid = partid;
+		ch->number = ch_number;
+		ch->flags = XPC_C_DISCONNECTED;
+
+		atomic_set(&ch->kthreads_assigned, 0);
+		atomic_set(&ch->kthreads_idle, 0);
+		atomic_set(&ch->kthreads_active, 0);
+
+		atomic_set(&ch->references, 0);
+		atomic_set(&ch->n_to_notify, 0);
+
+		spin_lock_init(&ch->lock);
+		init_completion(&ch->wdisconnect_wait);
+
+		atomic_set(&ch->n_on_msg_allocate_wq, 0);
+		init_waitqueue_head(&ch->msg_allocate_wq);
+		init_waitqueue_head(&ch->idle_wq);
+	}
+
+	ret = xpc_setup_ch_structures_sn(part);
+	if (ret != xpSuccess)
+		goto out_2;
+
+	/*
+	 * With the setting of the partition setup_state to XPC_P_SS_SETUP,
+	 * we're declaring that this partition is ready to go.
+	 */
+	part->setup_state = XPC_P_SS_SETUP;
+
+	return xpSuccess;
+
+	/* setup of ch structures failed */
+out_2:
+	kfree(part->remote_openclose_args_base);
+	part->remote_openclose_args = NULL;
+out_1:
+	kfree(part->channels);
+	part->channels = NULL;
+	return ret;
+}
+
+/*
+ * Teardown the channel structures necessary to support XPartition Communication
+ * between the specified remote partition and the local one.
+ */
+static void
+xpc_teardown_ch_structures(struct xpc_partition *part)
+{
+	DBUG_ON(atomic_read(&part->nchannels_engaged) != 0);
+	DBUG_ON(atomic_read(&part->nchannels_active) != 0);
 
 	/*
-	 * The kthread that XPC HB called us with will become the
-	 * channel manager for this partition. It will not return
-	 * back to XPC HB until the partition's XPC infrastructure
-	 * has been dismantled.
+	 * Make this partition inaccessible to local processes by marking it
+	 * as no longer setup. Then wait before proceeding with the teardown
+	 * until all existing references cease.
 	 */
+	DBUG_ON(part->setup_state != XPC_P_SS_SETUP);
+	part->setup_state = XPC_P_SS_WTEARDOWN;
 
-	(void)xpc_part_ref(part);	/* this will always succeed */
+	wait_event(part->teardown_wq, (atomic_read(&part->references) == 0));
 
-	if (xpc_make_first_contact(part) == xpSuccess)
-		xpc_channel_mgr(part);
+	/* now we can begin tearing down the infrastructure */
 
-	xpc_part_deref(part);
+	xpc_teardown_ch_structures_sn(part);
 
-	xpc_teardown_infrastructure(part);
+	kfree(part->remote_openclose_args_base);
+	part->remote_openclose_args = NULL;
+	kfree(part->channels);
+	part->channels = NULL;
+
+	part->setup_state = XPC_P_SS_TORNDOWN;
 }
 
+/*
+ * When XPC HB determines that a partition has come up, it will create a new
+ * kthread and that kthread will call this function to attempt to set up the
+ * basic infrastructure used for Cross Partition Communication with the newly
+ * upped partition.
+ *
+ * The kthread that was created by XPC HB and which setup the XPC
+ * infrastructure will remain assigned to the partition becoming the channel
+ * manager for that partition until the partition is deactivating, at which
+ * time the kthread will teardown the XPC infrastructure and then exit.
+ */
 static int
 xpc_activating(void *__partid)
 {
@@ -433,64 +599,47 @@ xpc_activating(void *__partid)
 	struct xpc_partition *part = &xpc_partitions[partid];
 	unsigned long irq_flags;
 
-	DBUG_ON(partid <= 0 || partid >= XP_MAX_PARTITIONS);
+	DBUG_ON(partid < 0 || partid >= xp_max_npartitions);
 
 	spin_lock_irqsave(&part->act_lock, irq_flags);
 
-	if (part->act_state == XPC_P_DEACTIVATING) {
-		part->act_state = XPC_P_INACTIVE;
+	if (part->act_state == XPC_P_AS_DEACTIVATING) {
+		part->act_state = XPC_P_AS_INACTIVE;
 		spin_unlock_irqrestore(&part->act_lock, irq_flags);
 		part->remote_rp_pa = 0;
 		return 0;
 	}
 
 	/* indicate the thread is activating */
-	DBUG_ON(part->act_state != XPC_P_ACTIVATION_REQ);
-	part->act_state = XPC_P_ACTIVATING;
+	DBUG_ON(part->act_state != XPC_P_AS_ACTIVATION_REQ);
+	part->act_state = XPC_P_AS_ACTIVATING;
 
 	XPC_SET_REASON(part, 0, 0);
 	spin_unlock_irqrestore(&part->act_lock, irq_flags);
 
-	dev_dbg(xpc_part, "bringing partition %d up\n", partid);
+	dev_dbg(xpc_part, "activating partition %d\n", partid);
 
-	/*
-	 * Register the remote partition's AMOs with SAL so it can handle
-	 * and cleanup errors within that address range should the remote
-	 * partition go down. We don't unregister this range because it is
-	 * difficult to tell when outstanding writes to the remote partition
-	 * are finished and thus when it is safe to unregister. This should
-	 * not result in wasted space in the SAL xp_addr_region table because
-	 * we should get the same page for remote_amos_page_pa after module
-	 * reloads and system reboots.
-	 */
-	if (sn_register_xp_addr_region(part->remote_amos_page_pa,
-				       PAGE_SIZE, 1) < 0) {
-		dev_warn(xpc_part, "xpc_partition_up(%d) failed to register "
-			 "xp_addr region\n", partid);
+	xpc_allow_hb(partid);
 
-		spin_lock_irqsave(&part->act_lock, irq_flags);
-		part->act_state = XPC_P_INACTIVE;
-		XPC_SET_REASON(part, xpPhysAddrRegFailed, __LINE__);
-		spin_unlock_irqrestore(&part->act_lock, irq_flags);
-		part->remote_rp_pa = 0;
-		return 0;
-	}
+	if (xpc_setup_ch_structures(part) == xpSuccess) {
+		(void)xpc_part_ref(part);	/* this will always succeed */
 
-	xpc_allow_hb(partid, xpc_vars);
-	xpc_IPI_send_activated(part);
+		if (xpc_make_first_contact(part) == xpSuccess) {
+			xpc_mark_partition_active(part);
+			xpc_channel_mgr(part);
+			/* won't return until partition is deactivating */
+		}
 
-	/*
-	 * xpc_partition_up() holds this thread and marks this partition as
-	 * XPC_P_ACTIVE by calling xpc_hb_mark_active().
-	 */
-	(void)xpc_partition_up(part);
+		xpc_part_deref(part);
+		xpc_teardown_ch_structures(part);
+	}
 
-	xpc_disallow_hb(partid, xpc_vars);
+	xpc_disallow_hb(partid);
 	xpc_mark_partition_inactive(part);
 
 	if (part->reason == xpReactivating) {
 		/* interrupting ourselves results in activating partition */
-		xpc_IPI_send_reactivate(part);
+		xpc_request_partition_reactivation(part);
 	}
 
 	return 0;
@@ -505,9 +654,9 @@ xpc_activate_partition(struct xpc_partition *part)
 
 	spin_lock_irqsave(&part->act_lock, irq_flags);
 
-	DBUG_ON(part->act_state != XPC_P_INACTIVE);
+	DBUG_ON(part->act_state != XPC_P_AS_INACTIVE);
 
-	part->act_state = XPC_P_ACTIVATION_REQ;
+	part->act_state = XPC_P_AS_ACTIVATION_REQ;
 	XPC_SET_REASON(part, xpCloneKThread, __LINE__);
 
 	spin_unlock_irqrestore(&part->act_lock, irq_flags);
@@ -516,62 +665,12 @@ xpc_activate_partition(struct xpc_partition *part)
 			      partid);
 	if (IS_ERR(kthread)) {
 		spin_lock_irqsave(&part->act_lock, irq_flags);
-		part->act_state = XPC_P_INACTIVE;
+		part->act_state = XPC_P_AS_INACTIVE;
 		XPC_SET_REASON(part, xpCloneKThreadFailed, __LINE__);
 		spin_unlock_irqrestore(&part->act_lock, irq_flags);
 	}
 }
 
-/*
- * Handle the receipt of a SGI_XPC_NOTIFY IRQ by seeing whether the specified
- * partition actually sent it. Since SGI_XPC_NOTIFY IRQs may be shared by more
- * than one partition, we use an AMO_t structure per partition to indicate
- * whether a partition has sent an IPI or not.  If it has, then wake up the
- * associated kthread to handle it.
- *
- * All SGI_XPC_NOTIFY IRQs received by XPC are the result of IPIs sent by XPC
- * running on other partitions.
- *
- * Noteworthy Arguments:
- *
- *	irq - Interrupt ReQuest number. NOT USED.
- *
- *	dev_id - partid of IPI's potential sender.
- */
-irqreturn_t
-xpc_notify_IRQ_handler(int irq, void *dev_id)
-{
-	short partid = (short)(u64)dev_id;
-	struct xpc_partition *part = &xpc_partitions[partid];
-
-	DBUG_ON(partid <= 0 || partid >= XP_MAX_PARTITIONS);
-
-	if (xpc_part_ref(part)) {
-		xpc_check_for_channel_activity(part);
-
-		xpc_part_deref(part);
-	}
-	return IRQ_HANDLED;
-}
-
-/*
- * Check to see if xpc_notify_IRQ_handler() dropped any IPIs on the floor
- * because the write to their associated IPI amo completed after the IRQ/IPI
- * was received.
- */
-void
-xpc_dropped_IPI_check(struct xpc_partition *part)
-{
-	if (xpc_part_ref(part)) {
-		xpc_check_for_channel_activity(part);
-
-		part->dropped_IPI_timer.expires = jiffies +
-		    XPC_P_DROPPED_IPI_WAIT;
-		add_timer(&part->dropped_IPI_timer);
-		xpc_part_deref(part);
-	}
-}
-
 void
 xpc_activate_kthreads(struct xpc_channel *ch, int needed)
 {
@@ -616,9 +715,9 @@ xpc_kthread_waitmsgs(struct xpc_partition *part, struct xpc_channel *ch)
 	do {
 		/* deliver messages to their intended recipients */
 
-		while (ch->w_local_GP.get < ch->w_remote_GP.put &&
+		while (xpc_n_of_deliverable_payloads(ch) > 0 &&
 		       !(ch->flags & XPC_C_DISCONNECTING)) {
-			xpc_deliver_msg(ch);
+			xpc_deliver_payload(ch);
 		}
 
 		if (atomic_inc_return(&ch->kthreads_idle) >
@@ -632,7 +731,7 @@ xpc_kthread_waitmsgs(struct xpc_partition *part, struct xpc_channel *ch)
 			"wait_event_interruptible_exclusive()\n");
 
 		(void)wait_event_interruptible_exclusive(ch->idle_wq,
-				(ch->w_local_GP.get < ch->w_remote_GP.put ||
+				(xpc_n_of_deliverable_payloads(ch) > 0 ||
 				 (ch->flags & XPC_C_DISCONNECTING)));
 
 		atomic_dec(&ch->kthreads_idle);
@@ -677,7 +776,7 @@ xpc_kthread_start(void *args)
 			 * additional kthreads to help deliver them. We only
 			 * need one less than total #of messages to deliver.
 			 */
-			n_needed = ch->w_remote_GP.put - ch->w_local_GP.get - 1;
+			n_needed = xpc_n_of_deliverable_payloads(ch) - 1;
 			if (n_needed > 0 && !(ch->flags & XPC_C_DISCONNECTING))
 				xpc_activate_kthreads(ch, n_needed);
 
@@ -703,11 +802,9 @@ xpc_kthread_start(void *args)
 	}
 	spin_unlock_irqrestore(&ch->lock, irq_flags);
 
-	if (atomic_dec_return(&ch->kthreads_assigned) == 0) {
-		if (atomic_dec_return(&part->nchannels_engaged) == 0) {
-			xpc_mark_partition_disengaged(part);
-			xpc_IPI_send_disengage(part);
-		}
+	if (atomic_dec_return(&ch->kthreads_assigned) == 0 &&
+	    atomic_dec_return(&part->nchannels_engaged) == 0) {
+		xpc_indicate_partition_disengaged(part);
 	}
 
 	xpc_msgqueue_deref(ch);
@@ -758,9 +855,9 @@ xpc_create_kthreads(struct xpc_channel *ch, int needed,
 		} else if (ch->flags & XPC_C_DISCONNECTING) {
 			break;
 
-		} else if (atomic_inc_return(&ch->kthreads_assigned) == 1) {
-			if (atomic_inc_return(&part->nchannels_engaged) == 1)
-				xpc_mark_partition_engaged(part);
+		} else if (atomic_inc_return(&ch->kthreads_assigned) == 1 &&
+			   atomic_inc_return(&part->nchannels_engaged) == 1) {
+				xpc_indicate_partition_engaged(part);
 		}
 		(void)xpc_part_ref(part);
 		xpc_msgqueue_ref(ch);
@@ -782,8 +879,7 @@ xpc_create_kthreads(struct xpc_channel *ch, int needed,
 
 			if (atomic_dec_return(&ch->kthreads_assigned) == 0 &&
 			    atomic_dec_return(&part->nchannels_engaged) == 0) {
-				xpc_mark_partition_disengaged(part);
-				xpc_IPI_send_disengage(part);
+				xpc_indicate_partition_disengaged(part);
 			}
 			xpc_msgqueue_deref(ch);
 			xpc_part_deref(part);
@@ -815,7 +911,7 @@ xpc_disconnect_wait(int ch_number)
 	int wakeup_channel_mgr;
 
 	/* now wait for all callouts to the caller's function to cease */
-	for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) {
+	for (partid = 0; partid < xp_max_npartitions; partid++) {
 		part = &xpc_partitions[partid];
 
 		if (!xpc_part_ref(part))
@@ -834,16 +930,15 @@ xpc_disconnect_wait(int ch_number)
 		DBUG_ON(!(ch->flags & XPC_C_DISCONNECTED));
 		wakeup_channel_mgr = 0;
 
-		if (ch->delayed_IPI_flags) {
-			if (part->act_state != XPC_P_DEACTIVATING) {
-				spin_lock(&part->IPI_lock);
-				XPC_SET_IPI_FLAGS(part->local_IPI_amo,
-						  ch->number,
-						  ch->delayed_IPI_flags);
-				spin_unlock(&part->IPI_lock);
+		if (ch->delayed_chctl_flags) {
+			if (part->act_state != XPC_P_AS_DEACTIVATING) {
+				spin_lock(&part->chctl_lock);
+				part->chctl.flags[ch->number] |=
+				    ch->delayed_chctl_flags;
+				spin_unlock(&part->chctl_lock);
 				wakeup_channel_mgr = 1;
 			}
-			ch->delayed_IPI_flags = 0;
+			ch->delayed_chctl_flags = 0;
 		}
 
 		ch->flags &= ~XPC_C_WDISCONNECT;
@@ -856,13 +951,63 @@ xpc_disconnect_wait(int ch_number)
 	}
 }
 
+static int
+xpc_setup_partitions(void)
+{
+	short partid;
+	struct xpc_partition *part;
+
+	xpc_partitions = kzalloc(sizeof(struct xpc_partition) *
+				 xp_max_npartitions, GFP_KERNEL);
+	if (xpc_partitions == NULL) {
+		dev_err(xpc_part, "can't get memory for partition structure\n");
+		return -ENOMEM;
+	}
+
+	/*
+	 * The first few fields of each entry of xpc_partitions[] need to
+	 * be initialized now so that calls to xpc_connect() and
+	 * xpc_disconnect() can be made prior to the activation of any remote
+	 * partition. NOTE THAT NONE OF THE OTHER FIELDS BELONGING TO THESE
+	 * ENTRIES ARE MEANINGFUL UNTIL AFTER AN ENTRY'S CORRESPONDING
+	 * PARTITION HAS BEEN ACTIVATED.
+	 */
+	for (partid = 0; partid < xp_max_npartitions; partid++) {
+		part = &xpc_partitions[partid];
+
+		DBUG_ON((u64)part != L1_CACHE_ALIGN((u64)part));
+
+		part->activate_IRQ_rcvd = 0;
+		spin_lock_init(&part->act_lock);
+		part->act_state = XPC_P_AS_INACTIVE;
+		XPC_SET_REASON(part, 0, 0);
+
+		init_timer(&part->disengage_timer);
+		part->disengage_timer.function =
+		    xpc_timeout_partition_disengage;
+		part->disengage_timer.data = (unsigned long)part;
+
+		part->setup_state = XPC_P_SS_UNSET;
+		init_waitqueue_head(&part->teardown_wq);
+		atomic_set(&part->references, 0);
+	}
+
+	return xpc_setup_partitions_sn();
+}
+
+static void
+xpc_teardown_partitions(void)
+{
+	kfree(xpc_partitions);
+}
+
 static void
 xpc_do_exit(enum xp_retval reason)
 {
 	short partid;
 	int active_part_count, printed_waiting_msg = 0;
 	struct xpc_partition *part;
-	unsigned long printmsg_time, disengage_request_timeout = 0;
+	unsigned long printmsg_time, disengage_timeout = 0;
 
 	/* a 'rmmod XPC' and a 'reboot' cannot both end up here together */
 	DBUG_ON(xpc_exiting == 1);
@@ -873,10 +1018,7 @@ xpc_do_exit(enum xp_retval reason)
 	 * the heartbeat checker thread in case it's sleeping.
 	 */
 	xpc_exiting = 1;
-	wake_up_interruptible(&xpc_act_IRQ_wq);
-
-	/* ignore all incoming interrupts */
-	free_irq(SGI_XPC_ACTIVATE, NULL);
+	wake_up_interruptible(&xpc_activate_IRQ_wq);
 
 	/* wait for the discovery thread to exit */
 	wait_for_completion(&xpc_discovery_exited);
@@ -889,17 +1031,17 @@ xpc_do_exit(enum xp_retval reason)
 
 	/* wait for all partitions to become inactive */
 
-	printmsg_time = jiffies + (XPC_DISENGAGE_PRINTMSG_INTERVAL * HZ);
-	xpc_disengage_request_timedout = 0;
+	printmsg_time = jiffies + (XPC_DEACTIVATE_PRINTMSG_INTERVAL * HZ);
+	xpc_disengage_timedout = 0;
 
 	do {
 		active_part_count = 0;
 
-		for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) {
+		for (partid = 0; partid < xp_max_npartitions; partid++) {
 			part = &xpc_partitions[partid];
 
 			if (xpc_partition_disengaged(part) &&
-			    part->act_state == XPC_P_INACTIVE) {
+			    part->act_state == XPC_P_AS_INACTIVE) {
 				continue;
 			}
 
@@ -907,36 +1049,32 @@ xpc_do_exit(enum xp_retval reason)
 
 			XPC_DEACTIVATE_PARTITION(part, reason);
 
-			if (part->disengage_request_timeout >
-			    disengage_request_timeout) {
-				disengage_request_timeout =
-				    part->disengage_request_timeout;
-			}
+			if (part->disengage_timeout > disengage_timeout)
+				disengage_timeout = part->disengage_timeout;
 		}
 
-		if (xpc_partition_engaged(-1UL)) {
-			if (time_after(jiffies, printmsg_time)) {
+		if (xpc_any_partition_engaged()) {
+			if (time_is_before_jiffies(printmsg_time)) {
 				dev_info(xpc_part, "waiting for remote "
-					 "partitions to disengage, timeout in "
-					 "%ld seconds\n",
-					 (disengage_request_timeout - jiffies)
-					 / HZ);
+					 "partitions to deactivate, timeout in "
+					 "%ld seconds\n", (disengage_timeout -
+					 jiffies) / HZ);
 				printmsg_time = jiffies +
-				    (XPC_DISENGAGE_PRINTMSG_INTERVAL * HZ);
+				    (XPC_DEACTIVATE_PRINTMSG_INTERVAL * HZ);
 				printed_waiting_msg = 1;
 			}
 
 		} else if (active_part_count > 0) {
 			if (printed_waiting_msg) {
 				dev_info(xpc_part, "waiting for local partition"
-					 " to disengage\n");
+					 " to deactivate\n");
 				printed_waiting_msg = 0;
 			}
 
 		} else {
-			if (!xpc_disengage_request_timedout) {
+			if (!xpc_disengage_timedout) {
 				dev_info(xpc_part, "all partitions have "
-					 "disengaged\n");
+					 "deactivated\n");
 			}
 			break;
 		}
@@ -946,33 +1084,28 @@ xpc_do_exit(enum xp_retval reason)
 
 	} while (1);
 
-	DBUG_ON(xpc_partition_engaged(-1UL));
+	DBUG_ON(xpc_any_partition_engaged());
+	DBUG_ON(xpc_any_hbs_allowed() != 0);
 
-	/* indicate to others that our reserved page is uninitialized */
-	xpc_rsvd_page->vars_pa = 0;
-
-	/* now it's time to eliminate our heartbeat */
-	del_timer_sync(&xpc_hb_timer);
-	DBUG_ON(xpc_vars->heartbeating_to_mask != 0);
+	xpc_teardown_rsvd_page();
 
 	if (reason == xpUnloading) {
-		/* take ourselves off of the reboot_notifier_list */
-		(void)unregister_reboot_notifier(&xpc_reboot_notifier);
-
-		/* take ourselves off of the die_notifier list */
 		(void)unregister_die_notifier(&xpc_die_notifier);
+		(void)unregister_reboot_notifier(&xpc_reboot_notifier);
 	}
 
-	/* close down protections for IPI operations */
-	xpc_restrict_IPI_ops();
-
 	/* clear the interface to XPC's functions */
 	xpc_clear_interface();
 
 	if (xpc_sysctl)
 		unregister_sysctl_table(xpc_sysctl);
 
-	kfree(xpc_remote_copy_buffer_base);
+	xpc_teardown_partitions();
+
+	if (is_shub())
+		xpc_exit_sn2();
+	else
+		xpc_exit_uv();
 }
 
 /*
@@ -1002,60 +1135,57 @@ xpc_system_reboot(struct notifier_block *nb, unsigned long event, void *unused)
 }
 
 /*
- * Notify other partitions to disengage from all references to our memory.
+ * Notify other partitions to deactivate from us by first disengaging from all
+ * references to our memory.
  */
 static void
-xpc_die_disengage(void)
+xpc_die_deactivate(void)
 {
 	struct xpc_partition *part;
 	short partid;
-	unsigned long engaged;
-	long time, printmsg_time, disengage_request_timeout;
+	int any_engaged;
+	long keep_waiting;
+	long wait_to_print;
 
 	/* keep xpc_hb_checker thread from doing anything (just in case) */
 	xpc_exiting = 1;
 
-	xpc_vars->heartbeating_to_mask = 0;	/* indicate we're deactivated */
+	xpc_disallow_all_hbs();	/*indicate we're deactivated */
 
-	for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) {
+	for (partid = 0; partid < xp_max_npartitions; partid++) {
 		part = &xpc_partitions[partid];
 
-		if (!XPC_SUPPORTS_DISENGAGE_REQUEST(part->
-		    remote_vars_version)) {
-
-			/* just in case it was left set by an earlier XPC */
-			xpc_clear_partition_engaged(1UL << partid);
-			continue;
-		}
-
-		if (xpc_partition_engaged(1UL << partid) ||
-		    part->act_state != XPC_P_INACTIVE) {
-			xpc_request_partition_disengage(part);
-			xpc_mark_partition_disengaged(part);
-			xpc_IPI_send_disengage(part);
+		if (xpc_partition_engaged(partid) ||
+		    part->act_state != XPC_P_AS_INACTIVE) {
+			xpc_request_partition_deactivation(part);
+			xpc_indicate_partition_disengaged(part);
 		}
 	}
 
-	time = rtc_time();
-	printmsg_time = time +
-	    (XPC_DISENGAGE_PRINTMSG_INTERVAL * sn_rtc_cycles_per_second);
-	disengage_request_timeout = time +
-	    (xpc_disengage_request_timelimit * sn_rtc_cycles_per_second);
-
-	/* wait for all other partitions to disengage from us */
+	/*
+	 * Though we requested that all other partitions deactivate from us,
+	 * we only wait until they've all disengaged or we've reached the
+	 * defined timelimit.
+	 *
+	 * Given that one iteration through the following while-loop takes
+	 * approximately 200 microseconds, calculate the #of loops to take
+	 * before bailing and the #of loops before printing a waiting message.
+	 */
+	keep_waiting = xpc_disengage_timelimit * 1000 * 5;
+	wait_to_print = XPC_DEACTIVATE_PRINTMSG_INTERVAL * 1000 * 5;
 
 	while (1) {
-		engaged = xpc_partition_engaged(-1UL);
-		if (!engaged) {
-			dev_info(xpc_part, "all partitions have disengaged\n");
+		any_engaged = xpc_any_partition_engaged();
+		if (!any_engaged) {
+			dev_info(xpc_part, "all partitions have deactivated\n");
 			break;
 		}
 
-		time = rtc_time();
-		if (time >= disengage_request_timeout) {
-			for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) {
-				if (engaged & (1UL << partid)) {
-					dev_info(xpc_part, "disengage from "
+		if (!keep_waiting--) {
+			for (partid = 0; partid < xp_max_npartitions;
+			     partid++) {
+				if (xpc_partition_engaged(partid)) {
+					dev_info(xpc_part, "deactivate from "
 						 "remote partition %d timed "
 						 "out\n", partid);
 				}
@@ -1063,15 +1193,15 @@ xpc_die_disengage(void)
 			break;
 		}
 
-		if (time >= printmsg_time) {
+		if (!wait_to_print--) {
 			dev_info(xpc_part, "waiting for remote partitions to "
-				 "disengage, timeout in %ld seconds\n",
-				 (disengage_request_timeout - time) /
-				 sn_rtc_cycles_per_second);
-			printmsg_time = time +
-			    (XPC_DISENGAGE_PRINTMSG_INTERVAL *
-			     sn_rtc_cycles_per_second);
+				 "deactivate, timeout in %ld seconds\n",
+				 keep_waiting / (1000 * 5));
+			wait_to_print = XPC_DEACTIVATE_PRINTMSG_INTERVAL *
+			    1000 * 5;
 		}
+
+		udelay(200);
 	}
 }
 
@@ -1086,10 +1216,11 @@ xpc_die_disengage(void)
 static int
 xpc_system_die(struct notifier_block *nb, unsigned long event, void *unused)
 {
+#ifdef CONFIG_IA64		/* !!! temporary kludge */
 	switch (event) {
 	case DIE_MACHINE_RESTART:
 	case DIE_MACHINE_HALT:
-		xpc_die_disengage();
+		xpc_die_deactivate();
 		break;
 
 	case DIE_KDEBUG_ENTER:
@@ -1100,8 +1231,7 @@ xpc_system_die(struct notifier_block *nb, unsigned long event, void *unused)
 		/* fall through */
 	case DIE_MCA_MONARCH_ENTER:
 	case DIE_INIT_MONARCH_ENTER:
-		xpc_vars->heartbeat++;
-		xpc_vars->heartbeat_offline = 1;
+		xpc_offline_heartbeat();
 		break;
 
 	case DIE_KDEBUG_LEAVE:
@@ -1112,10 +1242,12 @@ xpc_system_die(struct notifier_block *nb, unsigned long event, void *unused)
 		/* fall through */
 	case DIE_MCA_MONARCH_LEAVE:
 	case DIE_INIT_MONARCH_LEAVE:
-		xpc_vars->heartbeat++;
-		xpc_vars->heartbeat_offline = 0;
+		xpc_online_heartbeat();
 		break;
 	}
+#else
+	xpc_die_deactivate();
+#endif
 
 	return NOTIFY_DONE;
 }
@@ -1124,105 +1256,52 @@ int __init
 xpc_init(void)
 {
 	int ret;
-	short partid;
-	struct xpc_partition *part;
 	struct task_struct *kthread;
-	size_t buf_size;
-
-	if (!ia64_platform_is("sn2"))
-		return -ENODEV;
-
-	buf_size = max(XPC_RP_VARS_SIZE,
-		       XPC_RP_HEADER_SIZE + XP_NASID_MASK_BYTES);
-	xpc_remote_copy_buffer = xpc_kmalloc_cacheline_aligned(buf_size,
-							       GFP_KERNEL,
-						  &xpc_remote_copy_buffer_base);
-	if (xpc_remote_copy_buffer == NULL)
-		return -ENOMEM;
 
 	snprintf(xpc_part->bus_id, BUS_ID_SIZE, "part");
 	snprintf(xpc_chan->bus_id, BUS_ID_SIZE, "chan");
 
-	xpc_sysctl = register_sysctl_table(xpc_sys_dir);
-
-	/*
-	 * The first few fields of each entry of xpc_partitions[] need to
-	 * be initialized now so that calls to xpc_connect() and
-	 * xpc_disconnect() can be made prior to the activation of any remote
-	 * partition. NOTE THAT NONE OF THE OTHER FIELDS BELONGING TO THESE
-	 * ENTRIES ARE MEANINGFUL UNTIL AFTER AN ENTRY'S CORRESPONDING
-	 * PARTITION HAS BEEN ACTIVATED.
-	 */
-	for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) {
-		part = &xpc_partitions[partid];
-
-		DBUG_ON((u64)part != L1_CACHE_ALIGN((u64)part));
-
-		part->act_IRQ_rcvd = 0;
-		spin_lock_init(&part->act_lock);
-		part->act_state = XPC_P_INACTIVE;
-		XPC_SET_REASON(part, 0, 0);
+	if (is_shub()) {
+		/*
+		 * The ia64-sn2 architecture supports at most 64 partitions.
+		 * And the inability to unregister remote amos restricts us
+		 * further to only support exactly 64 partitions on this
+		 * architecture, no less.
+		 */
+		if (xp_max_npartitions != 64) {
+			dev_err(xpc_part, "max #of partitions not set to 64\n");
+			ret = -EINVAL;
+		} else {
+			ret = xpc_init_sn2();
+		}
 
-		init_timer(&part->disengage_request_timer);
-		part->disengage_request_timer.function =
-		    xpc_timeout_partition_disengage_request;
-		part->disengage_request_timer.data = (unsigned long)part;
+	} else if (is_uv()) {
+		ret = xpc_init_uv();
 
-		part->setup_state = XPC_P_UNSET;
-		init_waitqueue_head(&part->teardown_wq);
-		atomic_set(&part->references, 0);
+	} else {
+		ret = -ENODEV;
 	}
 
-	/*
-	 * Open up protections for IPI operations (and AMO operations on
-	 * Shub 1.1 systems).
-	 */
-	xpc_allow_IPI_ops();
-
-	/*
-	 * Interrupts being processed will increment this atomic variable and
-	 * awaken the heartbeat thread which will process the interrupts.
-	 */
-	atomic_set(&xpc_act_IRQ_rcvd, 0);
+	if (ret != 0)
+		return ret;
 
-	/*
-	 * This is safe to do before the xpc_hb_checker thread has started
-	 * because the handler releases a wait queue.  If an interrupt is
-	 * received before the thread is waiting, it will not go to sleep,
-	 * but rather immediately process the interrupt.
-	 */
-	ret = request_irq(SGI_XPC_ACTIVATE, xpc_act_IRQ_handler, 0,
-			  "xpc hb", NULL);
+	ret = xpc_setup_partitions();
 	if (ret != 0) {
-		dev_err(xpc_part, "can't register ACTIVATE IRQ handler, "
-			"errno=%d\n", -ret);
-
-		xpc_restrict_IPI_ops();
-
-		if (xpc_sysctl)
-			unregister_sysctl_table(xpc_sysctl);
-
-		kfree(xpc_remote_copy_buffer_base);
-		return -EBUSY;
+		dev_err(xpc_part, "can't get memory for partition structure\n");
+		goto out_1;
 	}
 
+	xpc_sysctl = register_sysctl_table(xpc_sys_dir);
+
 	/*
 	 * Fill the partition reserved page with the information needed by
 	 * other partitions to discover we are alive and establish initial
 	 * communications.
 	 */
-	xpc_rsvd_page = xpc_rsvd_page_init();
-	if (xpc_rsvd_page == NULL) {
-		dev_err(xpc_part, "could not setup our reserved page\n");
-
-		free_irq(SGI_XPC_ACTIVATE, NULL);
-		xpc_restrict_IPI_ops();
-
-		if (xpc_sysctl)
-			unregister_sysctl_table(xpc_sysctl);
-
-		kfree(xpc_remote_copy_buffer_base);
-		return -EBUSY;
+	ret = xpc_setup_rsvd_page();
+	if (ret != 0) {
+		dev_err(xpc_part, "can't setup our reserved page\n");
+		goto out_2;
 	}
 
 	/* add ourselves to the reboot_notifier_list */
@@ -1235,9 +1314,6 @@ xpc_init(void)
 	if (ret != 0)
 		dev_warn(xpc_part, "can't register die notifier\n");
 
-	init_timer(&xpc_hb_timer);
-	xpc_hb_timer.function = xpc_hb_beater;
-
 	/*
 	 * The real work-horse behind xpc.  This processes incoming
 	 * interrupts and monitors remote heartbeats.
@@ -1245,25 +1321,8 @@ xpc_init(void)
 	kthread = kthread_run(xpc_hb_checker, NULL, XPC_HB_CHECK_THREAD_NAME);
 	if (IS_ERR(kthread)) {
 		dev_err(xpc_part, "failed while forking hb check thread\n");
-
-		/* indicate to others that our reserved page is uninitialized */
-		xpc_rsvd_page->vars_pa = 0;
-
-		/* take ourselves off of the reboot_notifier_list */
-		(void)unregister_reboot_notifier(&xpc_reboot_notifier);
-
-		/* take ourselves off of the die_notifier list */
-		(void)unregister_die_notifier(&xpc_die_notifier);
-
-		del_timer_sync(&xpc_hb_timer);
-		free_irq(SGI_XPC_ACTIVATE, NULL);
-		xpc_restrict_IPI_ops();
-
-		if (xpc_sysctl)
-			unregister_sysctl_table(xpc_sysctl);
-
-		kfree(xpc_remote_copy_buffer_base);
-		return -EBUSY;
+		ret = -EBUSY;
+		goto out_3;
 	}
 
 	/*
@@ -1285,11 +1344,28 @@ xpc_init(void)
 
 	/* set the interface to point at XPC's functions */
 	xpc_set_interface(xpc_initiate_connect, xpc_initiate_disconnect,
-			  xpc_initiate_allocate, xpc_initiate_send,
-			  xpc_initiate_send_notify, xpc_initiate_received,
-			  xpc_initiate_partid_to_nasids);
+			  xpc_initiate_send, xpc_initiate_send_notify,
+			  xpc_initiate_received, xpc_initiate_partid_to_nasids);
 
 	return 0;
+
+	/* initialization was not successful */
+out_3:
+	xpc_teardown_rsvd_page();
+
+	(void)unregister_die_notifier(&xpc_die_notifier);
+	(void)unregister_reboot_notifier(&xpc_reboot_notifier);
+out_2:
+	if (xpc_sysctl)
+		unregister_sysctl_table(xpc_sysctl);
+
+	xpc_teardown_partitions();
+out_1:
+	if (is_shub())
+		xpc_exit_sn2();
+	else
+		xpc_exit_uv();
+	return ret;
 }
 
 module_init(xpc_init);
@@ -1314,9 +1390,9 @@ module_param(xpc_hb_check_interval, int, 0);
 MODULE_PARM_DESC(xpc_hb_check_interval, "Number of seconds between "
 		 "heartbeat checks.");
 
-module_param(xpc_disengage_request_timelimit, int, 0);
-MODULE_PARM_DESC(xpc_disengage_request_timelimit, "Number of seconds to wait "
-		 "for disengage request to complete.");
+module_param(xpc_disengage_timelimit, int, 0);
+MODULE_PARM_DESC(xpc_disengage_timelimit, "Number of seconds to wait "
+		 "for disengage to complete.");
 
 module_param(xpc_kdebug_ignore, int, 0);
 MODULE_PARM_DESC(xpc_kdebug_ignore, "Should lack of heartbeat be ignored by "
diff --git a/drivers/misc/sgi-xp/xpc_partition.c b/drivers/misc/sgi-xp/xpc_partition.c
index 7dd4b5812c4..6722f6fe4dc 100644
--- a/drivers/misc/sgi-xp/xpc_partition.c
+++ b/drivers/misc/sgi-xp/xpc_partition.c
@@ -15,57 +15,22 @@
  *
  */
 
-#include <linux/kernel.h>
-#include <linux/sysctl.h>
-#include <linux/cache.h>
-#include <linux/mmzone.h>
-#include <linux/nodemask.h>
-#include <asm/uncached.h>
-#include <asm/sn/bte.h>
-#include <asm/sn/intr.h>
-#include <asm/sn/sn_sal.h>
-#include <asm/sn/nodepda.h>
-#include <asm/sn/addrs.h>
+#include <linux/device.h>
+#include <linux/hardirq.h>
 #include "xpc.h"
 
 /* XPC is exiting flag */
 int xpc_exiting;
 
-/* SH_IPI_ACCESS shub register value on startup */
-static u64 xpc_sh1_IPI_access;
-static u64 xpc_sh2_IPI_access0;
-static u64 xpc_sh2_IPI_access1;
-static u64 xpc_sh2_IPI_access2;
-static u64 xpc_sh2_IPI_access3;
-
-/* original protection values for each node */
-u64 xpc_prot_vec[MAX_NUMNODES];
-
 /* this partition's reserved page pointers */
 struct xpc_rsvd_page *xpc_rsvd_page;
-static u64 *xpc_part_nasids;
-static u64 *xpc_mach_nasids;
-struct xpc_vars *xpc_vars;
-struct xpc_vars_part *xpc_vars_part;
+static unsigned long *xpc_part_nasids;
+unsigned long *xpc_mach_nasids;
 
-static int xp_nasid_mask_bytes;	/* actual size in bytes of nasid mask */
-static int xp_nasid_mask_words;	/* actual size in words of nasid mask */
-
-/*
- * For performance reasons, each entry of xpc_partitions[] is cacheline
- * aligned. And xpc_partitions[] is padded with an additional entry at the
- * end so that the last legitimate entry doesn't share its cacheline with
- * another variable.
- */
-struct xpc_partition xpc_partitions[XP_MAX_PARTITIONS + 1];
+static int xpc_nasid_mask_nbytes;	/* #of bytes in nasid mask */
+int xpc_nasid_mask_nlongs;	/* #of longs in nasid mask */
 
-/*
- * Generic buffer used to store a local copy of portions of a remote
- * partition's reserved page (either its header and part_nasids mask,
- * or its vars).
- */
-char *xpc_remote_copy_buffer;
-void *xpc_remote_copy_buffer_base;
+struct xpc_partition *xpc_partitions;
 
 /*
  * Guarantee that the kmalloc'd memory is cacheline aligned.
@@ -95,56 +60,59 @@ xpc_kmalloc_cacheline_aligned(size_t size, gfp_t flags, void **base)
  * Given a nasid, get the physical address of the  partition's reserved page
  * for that nasid. This function returns 0 on any error.
  */
-static u64
+static unsigned long
 xpc_get_rsvd_page_pa(int nasid)
 {
-	bte_result_t bte_res;
-	s64 status;
+	enum xp_retval ret;
 	u64 cookie = 0;
-	u64 rp_pa = nasid;	/* seed with nasid */
-	u64 len = 0;
-	u64 buf = buf;
-	u64 buf_len = 0;
+	unsigned long rp_pa = nasid;	/* seed with nasid */
+	size_t len = 0;
+	size_t buf_len = 0;
+	void *buf = buf;
 	void *buf_base = NULL;
 
 	while (1) {
 
-		status = sn_partition_reserved_page_pa(buf, &cookie, &rp_pa,
-						       &len);
+		/* !!! rp_pa will need to be _gpa on UV.
+		 * ??? So do we save it into the architecture specific parts
+		 * ??? of the xpc_partition structure? Do we rename this
+		 * ??? function or have two versions? Rename rp_pa for UV to
+		 * ??? rp_gpa?
+		 */
+		ret = xpc_get_partition_rsvd_page_pa(buf, &cookie, &rp_pa,
+						     &len);
 
-		dev_dbg(xpc_part, "SAL returned with status=%li, cookie="
-			"0x%016lx, address=0x%016lx, len=0x%016lx\n",
-			status, cookie, rp_pa, len);
+		dev_dbg(xpc_part, "SAL returned with ret=%d, cookie=0x%016lx, "
+			"address=0x%016lx, len=0x%016lx\n", ret,
+			(unsigned long)cookie, rp_pa, len);
 
-		if (status != SALRET_MORE_PASSES)
+		if (ret != xpNeedMoreInfo)
 			break;
 
+		/* !!! L1_CACHE_ALIGN() is only a sn2-bte_copy requirement */
 		if (L1_CACHE_ALIGN(len) > buf_len) {
 			kfree(buf_base);
 			buf_len = L1_CACHE_ALIGN(len);
-			buf = (u64)xpc_kmalloc_cacheline_aligned(buf_len,
-								 GFP_KERNEL,
-								 &buf_base);
+			buf = xpc_kmalloc_cacheline_aligned(buf_len, GFP_KERNEL,
+							    &buf_base);
 			if (buf_base == NULL) {
 				dev_err(xpc_part, "unable to kmalloc "
 					"len=0x%016lx\n", buf_len);
-				status = SALRET_ERROR;
+				ret = xpNoMemory;
 				break;
 			}
 		}
 
-		bte_res = xp_bte_copy(rp_pa, buf, buf_len,
-				      (BTE_NOTIFY | BTE_WACQUIRE), NULL);
-		if (bte_res != BTE_SUCCESS) {
-			dev_dbg(xpc_part, "xp_bte_copy failed %i\n", bte_res);
-			status = SALRET_ERROR;
+		ret = xp_remote_memcpy(xp_pa(buf), rp_pa, buf_len);
+		if (ret != xpSuccess) {
+			dev_dbg(xpc_part, "xp_remote_memcpy failed %d\n", ret);
 			break;
 		}
 	}
 
 	kfree(buf_base);
 
-	if (status != SALRET_OK)
+	if (ret != xpSuccess)
 		rp_pa = 0;
 
 	dev_dbg(xpc_part, "reserved page at phys address 0x%016lx\n", rp_pa);
@@ -156,300 +124,77 @@ xpc_get_rsvd_page_pa(int nasid)
  * other partitions to discover we are alive and establish initial
  * communications.
  */
-struct xpc_rsvd_page *
-xpc_rsvd_page_init(void)
+int
+xpc_setup_rsvd_page(void)
 {
+	int ret;
 	struct xpc_rsvd_page *rp;
-	AMO_t *amos_page;
-	u64 rp_pa, nasid_array = 0;
-	int i, ret;
+	unsigned long rp_pa;
+	unsigned long new_ts_jiffies;
 
 	/* get the local reserved page's address */
 
 	preempt_disable();
-	rp_pa = xpc_get_rsvd_page_pa(cpuid_to_nasid(smp_processor_id()));
+	rp_pa = xpc_get_rsvd_page_pa(xp_cpu_to_nasid(smp_processor_id()));
 	preempt_enable();
 	if (rp_pa == 0) {
 		dev_err(xpc_part, "SAL failed to locate the reserved page\n");
-		return NULL;
+		return -ESRCH;
 	}
 	rp = (struct xpc_rsvd_page *)__va(rp_pa);
 
-	if (rp->partid != sn_partition_id) {
-		dev_err(xpc_part, "the reserved page's partid of %d should be "
-			"%d\n", rp->partid, sn_partition_id);
-		return NULL;
+	if (rp->SAL_version < 3) {
+		/* SAL_versions < 3 had a SAL_partid defined as a u8 */
+		rp->SAL_partid &= 0xff;
+	}
+	BUG_ON(rp->SAL_partid != xp_partition_id);
+
+	if (rp->SAL_partid < 0 || rp->SAL_partid >= xp_max_npartitions) {
+		dev_err(xpc_part, "the reserved page's partid of %d is outside "
+			"supported range (< 0 || >= %d)\n", rp->SAL_partid,
+			xp_max_npartitions);
+		return -EINVAL;
 	}
 
 	rp->version = XPC_RP_VERSION;
+	rp->max_npartitions = xp_max_npartitions;
 
 	/* establish the actual sizes of the nasid masks */
 	if (rp->SAL_version == 1) {
 		/* SAL_version 1 didn't set the nasids_size field */
-		rp->nasids_size = 128;
+		rp->SAL_nasids_size = 128;
 	}
-	xp_nasid_mask_bytes = rp->nasids_size;
-	xp_nasid_mask_words = xp_nasid_mask_bytes / 8;
+	xpc_nasid_mask_nbytes = rp->SAL_nasids_size;
+	xpc_nasid_mask_nlongs = BITS_TO_LONGS(rp->SAL_nasids_size *
+					      BITS_PER_BYTE);
 
 	/* setup the pointers to the various items in the reserved page */
 	xpc_part_nasids = XPC_RP_PART_NASIDS(rp);
 	xpc_mach_nasids = XPC_RP_MACH_NASIDS(rp);
-	xpc_vars = XPC_RP_VARS(rp);
-	xpc_vars_part = XPC_RP_VARS_PART(rp);
-
-	/*
-	 * Before clearing xpc_vars, see if a page of AMOs had been previously
-	 * allocated. If not we'll need to allocate one and set permissions
-	 * so that cross-partition AMOs are allowed.
-	 *
-	 * The allocated AMO page needs MCA reporting to remain disabled after
-	 * XPC has unloaded.  To make this work, we keep a copy of the pointer
-	 * to this page (i.e., amos_page) in the struct xpc_vars structure,
-	 * which is pointed to by the reserved page, and re-use that saved copy
-	 * on subsequent loads of XPC. This AMO page is never freed, and its
-	 * memory protections are never restricted.
-	 */
-	amos_page = xpc_vars->amos_page;
-	if (amos_page == NULL) {
-		amos_page = (AMO_t *)TO_AMO(uncached_alloc_page(0, 1));
-		if (amos_page == NULL) {
-			dev_err(xpc_part, "can't allocate page of AMOs\n");
-			return NULL;
-		}
-
-		/*
-		 * Open up AMO-R/W to cpu.  This is done for Shub 1.1 systems
-		 * when xpc_allow_IPI_ops() is called via xpc_hb_init().
-		 */
-		if (!enable_shub_wars_1_1()) {
-			ret = sn_change_memprotect(ia64_tpa((u64)amos_page),
-						   PAGE_SIZE,
-						   SN_MEMPROT_ACCESS_CLASS_1,
-						   &nasid_array);
-			if (ret != 0) {
-				dev_err(xpc_part, "can't change memory "
-					"protections\n");
-				uncached_free_page(__IA64_UNCACHED_OFFSET |
-						   TO_PHYS((u64)amos_page), 1);
-				return NULL;
-			}
-		}
-	} else if (!IS_AMO_ADDRESS((u64)amos_page)) {
-		/*
-		 * EFI's XPBOOT can also set amos_page in the reserved page,
-		 * but it happens to leave it as an uncached physical address
-		 * and we need it to be an uncached virtual, so we'll have to
-		 * convert it.
-		 */
-		if (!IS_AMO_PHYS_ADDRESS((u64)amos_page)) {
-			dev_err(xpc_part, "previously used amos_page address "
-				"is bad = 0x%p\n", (void *)amos_page);
-			return NULL;
-		}
-		amos_page = (AMO_t *)TO_AMO((u64)amos_page);
-	}
-
-	/* clear xpc_vars */
-	memset(xpc_vars, 0, sizeof(struct xpc_vars));
-
-	xpc_vars->version = XPC_V_VERSION;
-	xpc_vars->act_nasid = cpuid_to_nasid(0);
-	xpc_vars->act_phys_cpuid = cpu_physical_id(0);
-	xpc_vars->vars_part_pa = __pa(xpc_vars_part);
-	xpc_vars->amos_page_pa = ia64_tpa((u64)amos_page);
-	xpc_vars->amos_page = amos_page;	/* save for next load of XPC */
-
-	/* clear xpc_vars_part */
-	memset((u64 *)xpc_vars_part, 0, sizeof(struct xpc_vars_part) *
-	       XP_MAX_PARTITIONS);
-
-	/* initialize the activate IRQ related AMO variables */
-	for (i = 0; i < xp_nasid_mask_words; i++)
-		(void)xpc_IPI_init(XPC_ACTIVATE_IRQ_AMOS + i);
-
-	/* initialize the engaged remote partitions related AMO variables */
-	(void)xpc_IPI_init(XPC_ENGAGED_PARTITIONS_AMO);
-	(void)xpc_IPI_init(XPC_DISENGAGE_REQUEST_AMO);
 
-	/* timestamp of when reserved page was setup by XPC */
-	rp->stamp = CURRENT_TIME;
+	ret = xpc_setup_rsvd_page_sn(rp);
+	if (ret != 0)
+		return ret;
 
 	/*
+	 * Set timestamp of when reserved page was setup by XPC.
 	 * This signifies to the remote partition that our reserved
 	 * page is initialized.
 	 */
-	rp->vars_pa = __pa(xpc_vars);
+	new_ts_jiffies = jiffies;
+	if (new_ts_jiffies == 0 || new_ts_jiffies == rp->ts_jiffies)
+		new_ts_jiffies++;
+	rp->ts_jiffies = new_ts_jiffies;
 
-	return rp;
+	xpc_rsvd_page = rp;
+	return 0;
 }
 
-/*
- * Change protections to allow IPI operations (and AMO operations on
- * Shub 1.1 systems).
- */
 void
-xpc_allow_IPI_ops(void)
+xpc_teardown_rsvd_page(void)
 {
-	int node;
-	int nasid;
-
-	/* >>> Change SH_IPI_ACCESS code to use SAL call once it is available */
-
-	if (is_shub2()) {
-		xpc_sh2_IPI_access0 =
-		    (u64)HUB_L((u64 *)LOCAL_MMR_ADDR(SH2_IPI_ACCESS0));
-		xpc_sh2_IPI_access1 =
-		    (u64)HUB_L((u64 *)LOCAL_MMR_ADDR(SH2_IPI_ACCESS1));
-		xpc_sh2_IPI_access2 =
-		    (u64)HUB_L((u64 *)LOCAL_MMR_ADDR(SH2_IPI_ACCESS2));
-		xpc_sh2_IPI_access3 =
-		    (u64)HUB_L((u64 *)LOCAL_MMR_ADDR(SH2_IPI_ACCESS3));
-
-		for_each_online_node(node) {
-			nasid = cnodeid_to_nasid(node);
-			HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS0),
-			      -1UL);
-			HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS1),
-			      -1UL);
-			HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS2),
-			      -1UL);
-			HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS3),
-			      -1UL);
-		}
-
-	} else {
-		xpc_sh1_IPI_access =
-		    (u64)HUB_L((u64 *)LOCAL_MMR_ADDR(SH1_IPI_ACCESS));
-
-		for_each_online_node(node) {
-			nasid = cnodeid_to_nasid(node);
-			HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH1_IPI_ACCESS),
-			      -1UL);
-
-			/*
-			 * Since the BIST collides with memory operations on
-			 * SHUB 1.1 sn_change_memprotect() cannot be used.
-			 */
-			if (enable_shub_wars_1_1()) {
-				/* open up everything */
-				xpc_prot_vec[node] = (u64)HUB_L((u64 *)
-								GLOBAL_MMR_ADDR
-								(nasid,
-						  SH1_MD_DQLP_MMR_DIR_PRIVEC0));
-				HUB_S((u64 *)
-				      GLOBAL_MMR_ADDR(nasid,
-						   SH1_MD_DQLP_MMR_DIR_PRIVEC0),
-				      -1UL);
-				HUB_S((u64 *)
-				      GLOBAL_MMR_ADDR(nasid,
-						   SH1_MD_DQRP_MMR_DIR_PRIVEC0),
-				      -1UL);
-			}
-		}
-	}
-}
-
-/*
- * Restrict protections to disallow IPI operations (and AMO operations on
- * Shub 1.1 systems).
- */
-void
-xpc_restrict_IPI_ops(void)
-{
-	int node;
-	int nasid;
-
-	/* >>> Change SH_IPI_ACCESS code to use SAL call once it is available */
-
-	if (is_shub2()) {
-
-		for_each_online_node(node) {
-			nasid = cnodeid_to_nasid(node);
-			HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS0),
-			      xpc_sh2_IPI_access0);
-			HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS1),
-			      xpc_sh2_IPI_access1);
-			HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS2),
-			      xpc_sh2_IPI_access2);
-			HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS3),
-			      xpc_sh2_IPI_access3);
-		}
-
-	} else {
-
-		for_each_online_node(node) {
-			nasid = cnodeid_to_nasid(node);
-			HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH1_IPI_ACCESS),
-			      xpc_sh1_IPI_access);
-
-			if (enable_shub_wars_1_1()) {
-				HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid,
-						   SH1_MD_DQLP_MMR_DIR_PRIVEC0),
-				      xpc_prot_vec[node]);
-				HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid,
-						   SH1_MD_DQRP_MMR_DIR_PRIVEC0),
-				      xpc_prot_vec[node]);
-			}
-		}
-	}
-}
-
-/*
- * At periodic intervals, scan through all active partitions and ensure
- * their heartbeat is still active.  If not, the partition is deactivated.
- */
-void
-xpc_check_remote_hb(void)
-{
-	struct xpc_vars *remote_vars;
-	struct xpc_partition *part;
-	short partid;
-	bte_result_t bres;
-
-	remote_vars = (struct xpc_vars *)xpc_remote_copy_buffer;
-
-	for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) {
-
-		if (xpc_exiting)
-			break;
-
-		if (partid == sn_partition_id)
-			continue;
-
-		part = &xpc_partitions[partid];
-
-		if (part->act_state == XPC_P_INACTIVE ||
-		    part->act_state == XPC_P_DEACTIVATING) {
-			continue;
-		}
-
-		/* pull the remote_hb cache line */
-		bres = xp_bte_copy(part->remote_vars_pa,
-				   (u64)remote_vars,
-				   XPC_RP_VARS_SIZE,
-				   (BTE_NOTIFY | BTE_WACQUIRE), NULL);
-		if (bres != BTE_SUCCESS) {
-			XPC_DEACTIVATE_PARTITION(part,
-						 xpc_map_bte_errors(bres));
-			continue;
-		}
-
-		dev_dbg(xpc_part, "partid = %d, heartbeat = %ld, last_heartbeat"
-			" = %ld, heartbeat_offline = %ld, HB_mask = 0x%lx\n",
-			partid, remote_vars->heartbeat, part->last_heartbeat,
-			remote_vars->heartbeat_offline,
-			remote_vars->heartbeating_to_mask);
-
-		if (((remote_vars->heartbeat == part->last_heartbeat) &&
-		     (remote_vars->heartbeat_offline == 0)) ||
-		    !xpc_hb_allowed(sn_partition_id, remote_vars)) {
-
-			XPC_DEACTIVATE_PARTITION(part, xpNoHeartbeat);
-			continue;
-		}
-
-		part->last_heartbeat = remote_vars->heartbeat;
-	}
+	/* a zero timestamp indicates our rsvd page is not initialized */
+	xpc_rsvd_page->ts_jiffies = 0;
 }
 
 /*
@@ -459,11 +204,12 @@ xpc_check_remote_hb(void)
  * is large enough to contain a copy of their reserved page header and
  * part_nasids mask.
  */
-static enum xp_retval
-xpc_get_remote_rp(int nasid, u64 *discovered_nasids,
-		  struct xpc_rsvd_page *remote_rp, u64 *remote_rp_pa)
+enum xp_retval
+xpc_get_remote_rp(int nasid, unsigned long *discovered_nasids,
+		  struct xpc_rsvd_page *remote_rp, unsigned long *remote_rp_pa)
 {
-	int bres, i;
+	int l;
+	enum xp_retval ret;
 
 	/* get the reserved page's physical address */
 
@@ -472,355 +218,45 @@ xpc_get_remote_rp(int nasid, u64 *discovered_nasids,
 		return xpNoRsvdPageAddr;
 
 	/* pull over the reserved page header and part_nasids mask */
-	bres = xp_bte_copy(*remote_rp_pa, (u64)remote_rp,
-			   XPC_RP_HEADER_SIZE + xp_nasid_mask_bytes,
-			   (BTE_NOTIFY | BTE_WACQUIRE), NULL);
-	if (bres != BTE_SUCCESS)
-		return xpc_map_bte_errors(bres);
+	ret = xp_remote_memcpy(xp_pa(remote_rp), *remote_rp_pa,
+			       XPC_RP_HEADER_SIZE + xpc_nasid_mask_nbytes);
+	if (ret != xpSuccess)
+		return ret;
 
 	if (discovered_nasids != NULL) {
-		u64 *remote_part_nasids = XPC_RP_PART_NASIDS(remote_rp);
-
-		for (i = 0; i < xp_nasid_mask_words; i++)
-			discovered_nasids[i] |= remote_part_nasids[i];
-	}
-
-	/* check that the partid is for another partition */
+		unsigned long *remote_part_nasids =
+		    XPC_RP_PART_NASIDS(remote_rp);
 
-	if (remote_rp->partid < 1 ||
-	    remote_rp->partid > (XP_MAX_PARTITIONS - 1)) {
-		return xpInvalidPartid;
+		for (l = 0; l < xpc_nasid_mask_nlongs; l++)
+			discovered_nasids[l] |= remote_part_nasids[l];
 	}
 
-	if (remote_rp->partid == sn_partition_id)
-		return xpLocalPartid;
+	/* zero timestamp indicates the reserved page has not been setup */
+	if (remote_rp->ts_jiffies == 0)
+		return xpRsvdPageNotSet;
 
 	if (XPC_VERSION_MAJOR(remote_rp->version) !=
 	    XPC_VERSION_MAJOR(XPC_RP_VERSION)) {
 		return xpBadVersion;
 	}
 
-	return xpSuccess;
-}
-
-/*
- * Get a copy of the remote partition's XPC variables from the reserved page.
- *
- * remote_vars points to a buffer that is cacheline aligned for BTE copies and
- * assumed to be of size XPC_RP_VARS_SIZE.
- */
-static enum xp_retval
-xpc_get_remote_vars(u64 remote_vars_pa, struct xpc_vars *remote_vars)
-{
-	int bres;
-
-	if (remote_vars_pa == 0)
-		return xpVarsNotSet;
-
-	/* pull over the cross partition variables */
-	bres = xp_bte_copy(remote_vars_pa, (u64)remote_vars, XPC_RP_VARS_SIZE,
-			   (BTE_NOTIFY | BTE_WACQUIRE), NULL);
-	if (bres != BTE_SUCCESS)
-		return xpc_map_bte_errors(bres);
-
-	if (XPC_VERSION_MAJOR(remote_vars->version) !=
-	    XPC_VERSION_MAJOR(XPC_V_VERSION)) {
-		return xpBadVersion;
-	}
-
-	return xpSuccess;
-}
-
-/*
- * Update the remote partition's info.
- */
-static void
-xpc_update_partition_info(struct xpc_partition *part, u8 remote_rp_version,
-			  struct timespec *remote_rp_stamp, u64 remote_rp_pa,
-			  u64 remote_vars_pa, struct xpc_vars *remote_vars)
-{
-	part->remote_rp_version = remote_rp_version;
-	dev_dbg(xpc_part, "  remote_rp_version = 0x%016x\n",
-		part->remote_rp_version);
-
-	part->remote_rp_stamp = *remote_rp_stamp;
-	dev_dbg(xpc_part, "  remote_rp_stamp (tv_sec = 0x%lx tv_nsec = 0x%lx\n",
-		part->remote_rp_stamp.tv_sec, part->remote_rp_stamp.tv_nsec);
-
-	part->remote_rp_pa = remote_rp_pa;
-	dev_dbg(xpc_part, "  remote_rp_pa = 0x%016lx\n", part->remote_rp_pa);
-
-	part->remote_vars_pa = remote_vars_pa;
-	dev_dbg(xpc_part, "  remote_vars_pa = 0x%016lx\n",
-		part->remote_vars_pa);
-
-	part->last_heartbeat = remote_vars->heartbeat;
-	dev_dbg(xpc_part, "  last_heartbeat = 0x%016lx\n",
-		part->last_heartbeat);
-
-	part->remote_vars_part_pa = remote_vars->vars_part_pa;
-	dev_dbg(xpc_part, "  remote_vars_part_pa = 0x%016lx\n",
-		part->remote_vars_part_pa);
-
-	part->remote_act_nasid = remote_vars->act_nasid;
-	dev_dbg(xpc_part, "  remote_act_nasid = 0x%x\n",
-		part->remote_act_nasid);
-
-	part->remote_act_phys_cpuid = remote_vars->act_phys_cpuid;
-	dev_dbg(xpc_part, "  remote_act_phys_cpuid = 0x%x\n",
-		part->remote_act_phys_cpuid);
-
-	part->remote_amos_page_pa = remote_vars->amos_page_pa;
-	dev_dbg(xpc_part, "  remote_amos_page_pa = 0x%lx\n",
-		part->remote_amos_page_pa);
-
-	part->remote_vars_version = remote_vars->version;
-	dev_dbg(xpc_part, "  remote_vars_version = 0x%x\n",
-		part->remote_vars_version);
-}
-
-/*
- * Prior code has determined the nasid which generated an IPI.  Inspect
- * that nasid to determine if its partition needs to be activated or
- * deactivated.
- *
- * A partition is consider "awaiting activation" if our partition
- * flags indicate it is not active and it has a heartbeat.  A
- * partition is considered "awaiting deactivation" if our partition
- * flags indicate it is active but it has no heartbeat or it is not
- * sending its heartbeat to us.
- *
- * To determine the heartbeat, the remote nasid must have a properly
- * initialized reserved page.
- */
-static void
-xpc_identify_act_IRQ_req(int nasid)
-{
-	struct xpc_rsvd_page *remote_rp;
-	struct xpc_vars *remote_vars;
-	u64 remote_rp_pa;
-	u64 remote_vars_pa;
-	int remote_rp_version;
-	int reactivate = 0;
-	int stamp_diff;
-	struct timespec remote_rp_stamp = { 0, 0 };
-	short partid;
-	struct xpc_partition *part;
-	enum xp_retval ret;
-
-	/* pull over the reserved page structure */
-
-	remote_rp = (struct xpc_rsvd_page *)xpc_remote_copy_buffer;
-
-	ret = xpc_get_remote_rp(nasid, NULL, remote_rp, &remote_rp_pa);
-	if (ret != xpSuccess) {
-		dev_warn(xpc_part, "unable to get reserved page from nasid %d, "
-			 "which sent interrupt, reason=%d\n", nasid, ret);
-		return;
-	}
-
-	remote_vars_pa = remote_rp->vars_pa;
-	remote_rp_version = remote_rp->version;
-	if (XPC_SUPPORTS_RP_STAMP(remote_rp_version))
-		remote_rp_stamp = remote_rp->stamp;
-
-	partid = remote_rp->partid;
-	part = &xpc_partitions[partid];
-
-	/* pull over the cross partition variables */
-
-	remote_vars = (struct xpc_vars *)xpc_remote_copy_buffer;
-
-	ret = xpc_get_remote_vars(remote_vars_pa, remote_vars);
-	if (ret != xpSuccess) {
-
-		dev_warn(xpc_part, "unable to get XPC variables from nasid %d, "
-			 "which sent interrupt, reason=%d\n", nasid, ret);
-
-		XPC_DEACTIVATE_PARTITION(part, ret);
-		return;
-	}
-
-	part->act_IRQ_rcvd++;
-
-	dev_dbg(xpc_part, "partid for nasid %d is %d; IRQs = %d; HB = "
-		"%ld:0x%lx\n", (int)nasid, (int)partid, part->act_IRQ_rcvd,
-		remote_vars->heartbeat, remote_vars->heartbeating_to_mask);
-
-	if (xpc_partition_disengaged(part) &&
-	    part->act_state == XPC_P_INACTIVE) {
-
-		xpc_update_partition_info(part, remote_rp_version,
-					  &remote_rp_stamp, remote_rp_pa,
-					  remote_vars_pa, remote_vars);
-
-		if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version)) {
-			if (xpc_partition_disengage_requested(1UL << partid)) {
-				/*
-				 * Other side is waiting on us to disengage,
-				 * even though we already have.
-				 */
-				return;
-			}
-		} else {
-			/* other side doesn't support disengage requests */
-			xpc_clear_partition_disengage_request(1UL << partid);
-		}
-
-		xpc_activate_partition(part);
-		return;
-	}
-
-	DBUG_ON(part->remote_rp_version == 0);
-	DBUG_ON(part->remote_vars_version == 0);
-
-	if (!XPC_SUPPORTS_RP_STAMP(part->remote_rp_version)) {
-		DBUG_ON(XPC_SUPPORTS_DISENGAGE_REQUEST(part->
-						       remote_vars_version));
-
-		if (!XPC_SUPPORTS_RP_STAMP(remote_rp_version)) {
-			DBUG_ON(XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->
-							       version));
-			/* see if the other side rebooted */
-			if (part->remote_amos_page_pa ==
-			    remote_vars->amos_page_pa &&
-			    xpc_hb_allowed(sn_partition_id, remote_vars)) {
-				/* doesn't look that way, so ignore the IPI */
-				return;
-			}
-		}
-
-		/*
-		 * Other side rebooted and previous XPC didn't support the
-		 * disengage request, so we don't need to do anything special.
-		 */
-
-		xpc_update_partition_info(part, remote_rp_version,
-					  &remote_rp_stamp, remote_rp_pa,
-					  remote_vars_pa, remote_vars);
-		part->reactivate_nasid = nasid;
-		XPC_DEACTIVATE_PARTITION(part, xpReactivating);
-		return;
-	}
-
-	DBUG_ON(!XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version));
-
-	if (!XPC_SUPPORTS_RP_STAMP(remote_rp_version)) {
-		DBUG_ON(!XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->version));
-
-		/*
-		 * Other side rebooted and previous XPC did support the
-		 * disengage request, but the new one doesn't.
-		 */
-
-		xpc_clear_partition_engaged(1UL << partid);
-		xpc_clear_partition_disengage_request(1UL << partid);
-
-		xpc_update_partition_info(part, remote_rp_version,
-					  &remote_rp_stamp, remote_rp_pa,
-					  remote_vars_pa, remote_vars);
-		reactivate = 1;
-
-	} else {
-		DBUG_ON(!XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->version));
-
-		stamp_diff = xpc_compare_stamps(&part->remote_rp_stamp,
-						&remote_rp_stamp);
-		if (stamp_diff != 0) {
-			DBUG_ON(stamp_diff >= 0);
-
-			/*
-			 * Other side rebooted and the previous XPC did support
-			 * the disengage request, as does the new one.
-			 */
-
-			DBUG_ON(xpc_partition_engaged(1UL << partid));
-			DBUG_ON(xpc_partition_disengage_requested(1UL <<
-								  partid));
-
-			xpc_update_partition_info(part, remote_rp_version,
-						  &remote_rp_stamp,
-						  remote_rp_pa, remote_vars_pa,
-						  remote_vars);
-			reactivate = 1;
-		}
-	}
-
-	if (part->disengage_request_timeout > 0 &&
-	    !xpc_partition_disengaged(part)) {
-		/* still waiting on other side to disengage from us */
-		return;
-	}
-
-	if (reactivate) {
-		part->reactivate_nasid = nasid;
-		XPC_DEACTIVATE_PARTITION(part, xpReactivating);
-
-	} else if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version) &&
-		   xpc_partition_disengage_requested(1UL << partid)) {
-		XPC_DEACTIVATE_PARTITION(part, xpOtherGoingDown);
+	/* check that both remote and local partids are valid for each side */
+	if (remote_rp->SAL_partid < 0 ||
+	    remote_rp->SAL_partid >= xp_max_npartitions ||
+	    remote_rp->max_npartitions <= xp_partition_id) {
+		return xpInvalidPartid;
 	}
-}
 
-/*
- * Loop through the activation AMO variables and process any bits
- * which are set.  Each bit indicates a nasid sending a partition
- * activation or deactivation request.
- *
- * Return #of IRQs detected.
- */
-int
-xpc_identify_act_IRQ_sender(void)
-{
-	int word, bit;
-	u64 nasid_mask;
-	u64 nasid;		/* remote nasid */
-	int n_IRQs_detected = 0;
-	AMO_t *act_amos;
-
-	act_amos = xpc_vars->amos_page + XPC_ACTIVATE_IRQ_AMOS;
-
-	/* scan through act AMO variable looking for non-zero entries */
-	for (word = 0; word < xp_nasid_mask_words; word++) {
-
-		if (xpc_exiting)
-			break;
-
-		nasid_mask = xpc_IPI_receive(&act_amos[word]);
-		if (nasid_mask == 0) {
-			/* no IRQs from nasids in this variable */
-			continue;
-		}
-
-		dev_dbg(xpc_part, "AMO[%d] gave back 0x%lx\n", word,
-			nasid_mask);
-
-		/*
-		 * If this nasid has been added to the machine since
-		 * our partition was reset, this will retain the
-		 * remote nasid in our reserved pages machine mask.
-		 * This is used in the event of module reload.
-		 */
-		xpc_mach_nasids[word] |= nasid_mask;
-
-		/* locate the nasid(s) which sent interrupts */
+	if (remote_rp->SAL_partid == xp_partition_id)
+		return xpLocalPartid;
 
-		for (bit = 0; bit < (8 * sizeof(u64)); bit++) {
-			if (nasid_mask & (1UL << bit)) {
-				n_IRQs_detected++;
-				nasid = XPC_NASID_FROM_W_B(word, bit);
-				dev_dbg(xpc_part, "interrupt from nasid %ld\n",
-					nasid);
-				xpc_identify_act_IRQ_req(nasid);
-			}
-		}
-	}
-	return n_IRQs_detected;
+	return xpSuccess;
 }
 
 /*
- * See if the other side has responded to a partition disengage request
- * from us.
+ * See if the other side has responded to a partition deactivate request
+ * from us. Though we requested the remote partition to deactivate with regard
+ * to us, we really only need to wait for the other side to disengage from us.
  */
 int
 xpc_partition_disengaged(struct xpc_partition *part)
@@ -828,41 +264,37 @@ xpc_partition_disengaged(struct xpc_partition *part)
 	short partid = XPC_PARTID(part);
 	int disengaged;
 
-	disengaged = (xpc_partition_engaged(1UL << partid) == 0);
-	if (part->disengage_request_timeout) {
+	disengaged = !xpc_partition_engaged(partid);
+	if (part->disengage_timeout) {
 		if (!disengaged) {
-			if (time_before(jiffies,
-			    part->disengage_request_timeout)) {
+			if (time_is_after_jiffies(part->disengage_timeout)) {
 				/* timelimit hasn't been reached yet */
 				return 0;
 			}
 
 			/*
-			 * Other side hasn't responded to our disengage
+			 * Other side hasn't responded to our deactivate
 			 * request in a timely fashion, so assume it's dead.
 			 */
 
-			dev_info(xpc_part, "disengage from remote partition %d "
-				 "timed out\n", partid);
-			xpc_disengage_request_timedout = 1;
-			xpc_clear_partition_engaged(1UL << partid);
+			dev_info(xpc_part, "deactivate request to remote "
+				 "partition %d timed out\n", partid);
+			xpc_disengage_timedout = 1;
+			xpc_assume_partition_disengaged(partid);
 			disengaged = 1;
 		}
-		part->disengage_request_timeout = 0;
+		part->disengage_timeout = 0;
 
 		/* cancel the timer function, provided it's not us */
-		if (!in_interrupt()) {
-			del_singleshot_timer_sync(&part->
-						  disengage_request_timer);
-		}
+		if (!in_interrupt())
+			del_singleshot_timer_sync(&part->disengage_timer);
 
-		DBUG_ON(part->act_state != XPC_P_DEACTIVATING &&
-			part->act_state != XPC_P_INACTIVE);
-		if (part->act_state != XPC_P_INACTIVE)
+		DBUG_ON(part->act_state != XPC_P_AS_DEACTIVATING &&
+			part->act_state != XPC_P_AS_INACTIVE);
+		if (part->act_state != XPC_P_AS_INACTIVE)
 			xpc_wakeup_channel_mgr(part);
 
-		if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version))
-			xpc_cancel_partition_disengage_request(part);
+		xpc_cancel_partition_deactivation_request(part);
 	}
 	return disengaged;
 }
@@ -879,8 +311,8 @@ xpc_mark_partition_active(struct xpc_partition *part)
 	dev_dbg(xpc_part, "setting partition %d to ACTIVE\n", XPC_PARTID(part));
 
 	spin_lock_irqsave(&part->act_lock, irq_flags);
-	if (part->act_state == XPC_P_ACTIVATING) {
-		part->act_state = XPC_P_ACTIVE;
+	if (part->act_state == XPC_P_AS_ACTIVATING) {
+		part->act_state = XPC_P_AS_ACTIVE;
 		ret = xpSuccess;
 	} else {
 		DBUG_ON(part->reason == xpSuccess);
@@ -892,7 +324,7 @@ xpc_mark_partition_active(struct xpc_partition *part)
 }
 
 /*
- * Notify XPC that the partition is down.
+ * Start the process of deactivating the specified partition.
  */
 void
 xpc_deactivate_partition(const int line, struct xpc_partition *part,
@@ -902,16 +334,16 @@ xpc_deactivate_partition(const int line, struct xpc_partition *part,
 
 	spin_lock_irqsave(&part->act_lock, irq_flags);
 
-	if (part->act_state == XPC_P_INACTIVE) {
+	if (part->act_state == XPC_P_AS_INACTIVE) {
 		XPC_SET_REASON(part, reason, line);
 		spin_unlock_irqrestore(&part->act_lock, irq_flags);
 		if (reason == xpReactivating) {
 			/* we interrupt ourselves to reactivate partition */
-			xpc_IPI_send_reactivate(part);
+			xpc_request_partition_reactivation(part);
 		}
 		return;
 	}
-	if (part->act_state == XPC_P_DEACTIVATING) {
+	if (part->act_state == XPC_P_AS_DEACTIVATING) {
 		if ((part->reason == xpUnloading && reason != xpUnloading) ||
 		    reason == xpReactivating) {
 			XPC_SET_REASON(part, reason, line);
@@ -920,22 +352,18 @@ xpc_deactivate_partition(const int line, struct xpc_partition *part,
 		return;
 	}
 
-	part->act_state = XPC_P_DEACTIVATING;
+	part->act_state = XPC_P_AS_DEACTIVATING;
 	XPC_SET_REASON(part, reason, line);
 
 	spin_unlock_irqrestore(&part->act_lock, irq_flags);
 
-	if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version)) {
-		xpc_request_partition_disengage(part);
-		xpc_IPI_send_disengage(part);
+	/* ask remote partition to deactivate with regard to us */
+	xpc_request_partition_deactivation(part);
 
-		/* set a timelimit on the disengage request */
-		part->disengage_request_timeout = jiffies +
-		    (xpc_disengage_request_timelimit * HZ);
-		part->disengage_request_timer.expires =
-		    part->disengage_request_timeout;
-		add_timer(&part->disengage_request_timer);
-	}
+	/* set a timelimit on the disengage phase of the deactivation request */
+	part->disengage_timeout = jiffies + (xpc_disengage_timelimit * HZ);
+	part->disengage_timer.expires = part->disengage_timeout;
+	add_timer(&part->disengage_timer);
 
 	dev_dbg(xpc_part, "bringing partition %d down, reason = %d\n",
 		XPC_PARTID(part), reason);
@@ -955,7 +383,7 @@ xpc_mark_partition_inactive(struct xpc_partition *part)
 		XPC_PARTID(part));
 
 	spin_lock_irqsave(&part->act_lock, irq_flags);
-	part->act_state = XPC_P_INACTIVE;
+	part->act_state = XPC_P_AS_INACTIVE;
 	spin_unlock_irqrestore(&part->act_lock, irq_flags);
 	part->remote_rp_pa = 0;
 }
@@ -974,28 +402,22 @@ xpc_discovery(void)
 {
 	void *remote_rp_base;
 	struct xpc_rsvd_page *remote_rp;
-	struct xpc_vars *remote_vars;
-	u64 remote_rp_pa;
-	u64 remote_vars_pa;
+	unsigned long remote_rp_pa;
 	int region;
 	int region_size;
 	int max_regions;
 	int nasid;
 	struct xpc_rsvd_page *rp;
-	short partid;
-	struct xpc_partition *part;
-	u64 *discovered_nasids;
+	unsigned long *discovered_nasids;
 	enum xp_retval ret;
 
 	remote_rp = xpc_kmalloc_cacheline_aligned(XPC_RP_HEADER_SIZE +
-						  xp_nasid_mask_bytes,
+						  xpc_nasid_mask_nbytes,
 						  GFP_KERNEL, &remote_rp_base);
 	if (remote_rp == NULL)
 		return;
 
-	remote_vars = (struct xpc_vars *)remote_rp;
-
-	discovered_nasids = kzalloc(sizeof(u64) * xp_nasid_mask_words,
+	discovered_nasids = kzalloc(sizeof(long) * xpc_nasid_mask_nlongs,
 				    GFP_KERNEL);
 	if (discovered_nasids == NULL) {
 		kfree(remote_rp_base);
@@ -1010,7 +432,7 @@ xpc_discovery(void)
 	 * protection is in regards to memory, IOI and IPI.
 	 */
 	max_regions = 64;
-	region_size = sn_region_size;
+	region_size = xp_region_size;
 
 	switch (region_size) {
 	case 128:
@@ -1038,28 +460,28 @@ xpc_discovery(void)
 
 			dev_dbg(xpc_part, "checking nasid %d\n", nasid);
 
-			if (XPC_NASID_IN_ARRAY(nasid, xpc_part_nasids)) {
+			if (test_bit(nasid / 2, xpc_part_nasids)) {
 				dev_dbg(xpc_part, "PROM indicates Nasid %d is "
 					"part of the local partition; skipping "
 					"region\n", nasid);
 				break;
 			}
 
-			if (!(XPC_NASID_IN_ARRAY(nasid, xpc_mach_nasids))) {
+			if (!(test_bit(nasid / 2, xpc_mach_nasids))) {
 				dev_dbg(xpc_part, "PROM indicates Nasid %d was "
 					"not on Numa-Link network at reset\n",
 					nasid);
 				continue;
 			}
 
-			if (XPC_NASID_IN_ARRAY(nasid, discovered_nasids)) {
+			if (test_bit(nasid / 2, discovered_nasids)) {
 				dev_dbg(xpc_part, "Nasid %d is part of a "
 					"partition which was previously "
 					"discovered\n", nasid);
 				continue;
 			}
 
-			/* pull over the reserved page structure */
+			/* pull over the rsvd page header & part_nasids mask */
 
 			ret = xpc_get_remote_rp(nasid, discovered_nasids,
 						remote_rp, &remote_rp_pa);
@@ -1074,72 +496,8 @@ xpc_discovery(void)
 				continue;
 			}
 
-			remote_vars_pa = remote_rp->vars_pa;
-
-			partid = remote_rp->partid;
-			part = &xpc_partitions[partid];
-
-			/* pull over the cross partition variables */
-
-			ret = xpc_get_remote_vars(remote_vars_pa, remote_vars);
-			if (ret != xpSuccess) {
-				dev_dbg(xpc_part, "unable to get XPC variables "
-					"from nasid %d, reason=%d\n", nasid,
-					ret);
-
-				XPC_DEACTIVATE_PARTITION(part, ret);
-				continue;
-			}
-
-			if (part->act_state != XPC_P_INACTIVE) {
-				dev_dbg(xpc_part, "partition %d on nasid %d is "
-					"already activating\n", partid, nasid);
-				break;
-			}
-
-			/*
-			 * Register the remote partition's AMOs with SAL so it
-			 * can handle and cleanup errors within that address
-			 * range should the remote partition go down. We don't
-			 * unregister this range because it is difficult to
-			 * tell when outstanding writes to the remote partition
-			 * are finished and thus when it is thus safe to
-			 * unregister. This should not result in wasted space
-			 * in the SAL xp_addr_region table because we should
-			 * get the same page for remote_act_amos_pa after
-			 * module reloads and system reboots.
-			 */
-			if (sn_register_xp_addr_region
-			    (remote_vars->amos_page_pa, PAGE_SIZE, 1) < 0) {
-				dev_dbg(xpc_part,
-					"partition %d failed to "
-					"register xp_addr region 0x%016lx\n",
-					partid, remote_vars->amos_page_pa);
-
-				XPC_SET_REASON(part, xpPhysAddrRegFailed,
-					       __LINE__);
-				break;
-			}
-
-			/*
-			 * The remote nasid is valid and available.
-			 * Send an interrupt to that nasid to notify
-			 * it that we are ready to begin activation.
-			 */
-			dev_dbg(xpc_part, "sending an interrupt to AMO 0x%lx, "
-				"nasid %d, phys_cpuid 0x%x\n",
-				remote_vars->amos_page_pa,
-				remote_vars->act_nasid,
-				remote_vars->act_phys_cpuid);
-
-			if (XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->
-							   version)) {
-				part->remote_amos_page_pa =
-				    remote_vars->amos_page_pa;
-				xpc_mark_partition_disengaged(part);
-				xpc_cancel_partition_disengage_request(part);
-			}
-			xpc_IPI_send_activate(remote_vars);
+			xpc_request_partition_activation(remote_rp,
+							 remote_rp_pa, nasid);
 		}
 	}
 
@@ -1155,20 +513,16 @@ enum xp_retval
 xpc_initiate_partid_to_nasids(short partid, void *nasid_mask)
 {
 	struct xpc_partition *part;
-	u64 part_nasid_pa;
-	int bte_res;
+	unsigned long part_nasid_pa;
 
 	part = &xpc_partitions[partid];
 	if (part->remote_rp_pa == 0)
 		return xpPartitionDown;
 
-	memset(nasid_mask, 0, XP_NASID_MASK_BYTES);
-
-	part_nasid_pa = (u64)XPC_RP_PART_NASIDS(part->remote_rp_pa);
+	memset(nasid_mask, 0, xpc_nasid_mask_nbytes);
 
-	bte_res = xp_bte_copy(part_nasid_pa, (u64)nasid_mask,
-			      xp_nasid_mask_bytes, (BTE_NOTIFY | BTE_WACQUIRE),
-			      NULL);
+	part_nasid_pa = (unsigned long)XPC_RP_PART_NASIDS(part->remote_rp_pa);
 
-	return xpc_map_bte_errors(bte_res);
+	return xp_remote_memcpy(xp_pa(nasid_mask), part_nasid_pa,
+				xpc_nasid_mask_nbytes);
 }
diff --git a/drivers/misc/sgi-xp/xpc_sn2.c b/drivers/misc/sgi-xp/xpc_sn2.c
new file mode 100644
index 00000000000..b4882ccf634
--- /dev/null
+++ b/drivers/misc/sgi-xp/xpc_sn2.c
@@ -0,0 +1,2404 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (c) 2008 Silicon Graphics, Inc.  All Rights Reserved.
+ */
+
+/*
+ * Cross Partition Communication (XPC) sn2-based functions.
+ *
+ *     Architecture specific implementation of common functions.
+ *
+ */
+
+#include <linux/delay.h>
+#include <asm/uncached.h>
+#include <asm/sn/mspec.h>
+#include <asm/sn/sn_sal.h>
+#include "xpc.h"
+
+/*
+ * Define the number of u64s required to represent all the C-brick nasids
+ * as a bitmap.  The cross-partition kernel modules deal only with
+ * C-brick nasids, thus the need for bitmaps which don't account for
+ * odd-numbered (non C-brick) nasids.
+ */
+#define XPC_MAX_PHYSNODES_SN2	(MAX_NUMALINK_NODES / 2)
+#define XP_NASID_MASK_BYTES_SN2	((XPC_MAX_PHYSNODES_SN2 + 7) / 8)
+#define XP_NASID_MASK_WORDS_SN2	((XPC_MAX_PHYSNODES_SN2 + 63) / 64)
+
+/*
+ * Memory for XPC's amo variables is allocated by the MSPEC driver. These
+ * pages are located in the lowest granule. The lowest granule uses 4k pages
+ * for cached references and an alternate TLB handler to never provide a
+ * cacheable mapping for the entire region. This will prevent speculative
+ * reading of cached copies of our lines from being issued which will cause
+ * a PI FSB Protocol error to be generated by the SHUB. For XPC, we need 64
+ * amo variables (based on XP_MAX_NPARTITIONS_SN2) to identify the senders of
+ * NOTIFY IRQs, 128 amo variables (based on XP_NASID_MASK_WORDS_SN2) to identify
+ * the senders of ACTIVATE IRQs, 1 amo variable to identify which remote
+ * partitions (i.e., XPCs) consider themselves currently engaged with the
+ * local XPC and 1 amo variable to request partition deactivation.
+ */
+#define XPC_NOTIFY_IRQ_AMOS_SN2		0
+#define XPC_ACTIVATE_IRQ_AMOS_SN2	(XPC_NOTIFY_IRQ_AMOS_SN2 + \
+					 XP_MAX_NPARTITIONS_SN2)
+#define XPC_ENGAGED_PARTITIONS_AMO_SN2	(XPC_ACTIVATE_IRQ_AMOS_SN2 + \
+					 XP_NASID_MASK_WORDS_SN2)
+#define XPC_DEACTIVATE_REQUEST_AMO_SN2	(XPC_ENGAGED_PARTITIONS_AMO_SN2 + 1)
+
+/*
+ * Buffer used to store a local copy of portions of a remote partition's
+ * reserved page (either its header and part_nasids mask, or its vars).
+ */
+static void *xpc_remote_copy_buffer_base_sn2;
+static char *xpc_remote_copy_buffer_sn2;
+
+static struct xpc_vars_sn2 *xpc_vars_sn2;
+static struct xpc_vars_part_sn2 *xpc_vars_part_sn2;
+
+static int
+xpc_setup_partitions_sn_sn2(void)
+{
+	/* nothing needs to be done */
+	return 0;
+}
+
+/* SH_IPI_ACCESS shub register value on startup */
+static u64 xpc_sh1_IPI_access_sn2;
+static u64 xpc_sh2_IPI_access0_sn2;
+static u64 xpc_sh2_IPI_access1_sn2;
+static u64 xpc_sh2_IPI_access2_sn2;
+static u64 xpc_sh2_IPI_access3_sn2;
+
+/*
+ * Change protections to allow IPI operations.
+ */
+static void
+xpc_allow_IPI_ops_sn2(void)
+{
+	int node;
+	int nasid;
+
+	/* !!! The following should get moved into SAL. */
+	if (is_shub2()) {
+		xpc_sh2_IPI_access0_sn2 =
+		    (u64)HUB_L((u64 *)LOCAL_MMR_ADDR(SH2_IPI_ACCESS0));
+		xpc_sh2_IPI_access1_sn2 =
+		    (u64)HUB_L((u64 *)LOCAL_MMR_ADDR(SH2_IPI_ACCESS1));
+		xpc_sh2_IPI_access2_sn2 =
+		    (u64)HUB_L((u64 *)LOCAL_MMR_ADDR(SH2_IPI_ACCESS2));
+		xpc_sh2_IPI_access3_sn2 =
+		    (u64)HUB_L((u64 *)LOCAL_MMR_ADDR(SH2_IPI_ACCESS3));
+
+		for_each_online_node(node) {
+			nasid = cnodeid_to_nasid(node);
+			HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS0),
+			      -1UL);
+			HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS1),
+			      -1UL);
+			HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS2),
+			      -1UL);
+			HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS3),
+			      -1UL);
+		}
+	} else {
+		xpc_sh1_IPI_access_sn2 =
+		    (u64)HUB_L((u64 *)LOCAL_MMR_ADDR(SH1_IPI_ACCESS));
+
+		for_each_online_node(node) {
+			nasid = cnodeid_to_nasid(node);
+			HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH1_IPI_ACCESS),
+			      -1UL);
+		}
+	}
+}
+
+/*
+ * Restrict protections to disallow IPI operations.
+ */
+static void
+xpc_disallow_IPI_ops_sn2(void)
+{
+	int node;
+	int nasid;
+
+	/* !!! The following should get moved into SAL. */
+	if (is_shub2()) {
+		for_each_online_node(node) {
+			nasid = cnodeid_to_nasid(node);
+			HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS0),
+			      xpc_sh2_IPI_access0_sn2);
+			HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS1),
+			      xpc_sh2_IPI_access1_sn2);
+			HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS2),
+			      xpc_sh2_IPI_access2_sn2);
+			HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS3),
+			      xpc_sh2_IPI_access3_sn2);
+		}
+	} else {
+		for_each_online_node(node) {
+			nasid = cnodeid_to_nasid(node);
+			HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH1_IPI_ACCESS),
+			      xpc_sh1_IPI_access_sn2);
+		}
+	}
+}
+
+/*
+ * The following set of functions are used for the sending and receiving of
+ * IRQs (also known as IPIs). There are two flavors of IRQs, one that is
+ * associated with partition activity (SGI_XPC_ACTIVATE) and the other that
+ * is associated with channel activity (SGI_XPC_NOTIFY).
+ */
+
+static u64
+xpc_receive_IRQ_amo_sn2(struct amo *amo)
+{
+	return FETCHOP_LOAD_OP(TO_AMO((u64)&amo->variable), FETCHOP_CLEAR);
+}
+
+static enum xp_retval
+xpc_send_IRQ_sn2(struct amo *amo, u64 flag, int nasid, int phys_cpuid,
+		 int vector)
+{
+	int ret = 0;
+	unsigned long irq_flags;
+
+	local_irq_save(irq_flags);
+
+	FETCHOP_STORE_OP(TO_AMO((u64)&amo->variable), FETCHOP_OR, flag);
+	sn_send_IPI_phys(nasid, phys_cpuid, vector, 0);
+
+	/*
+	 * We must always use the nofault function regardless of whether we
+	 * are on a Shub 1.1 system or a Shub 1.2 slice 0xc processor. If we
+	 * didn't, we'd never know that the other partition is down and would
+	 * keep sending IRQs and amos to it until the heartbeat times out.
+	 */
+	ret = xp_nofault_PIOR((u64 *)GLOBAL_MMR_ADDR(NASID_GET(&amo->variable),
+						     xp_nofault_PIOR_target));
+
+	local_irq_restore(irq_flags);
+
+	return (ret == 0) ? xpSuccess : xpPioReadError;
+}
+
+static struct amo *
+xpc_init_IRQ_amo_sn2(int index)
+{
+	struct amo *amo = xpc_vars_sn2->amos_page + index;
+
+	(void)xpc_receive_IRQ_amo_sn2(amo);	/* clear amo variable */
+	return amo;
+}
+
+/*
+ * Functions associated with SGI_XPC_ACTIVATE IRQ.
+ */
+
+/*
+ * Notify the heartbeat check thread that an activate IRQ has been received.
+ */
+static irqreturn_t
+xpc_handle_activate_IRQ_sn2(int irq, void *dev_id)
+{
+	unsigned long irq_flags;
+
+	spin_lock_irqsave(&xpc_activate_IRQ_rcvd_lock, irq_flags);
+	xpc_activate_IRQ_rcvd++;
+	spin_unlock_irqrestore(&xpc_activate_IRQ_rcvd_lock, irq_flags);
+
+	wake_up_interruptible(&xpc_activate_IRQ_wq);
+	return IRQ_HANDLED;
+}
+
+/*
+ * Flag the appropriate amo variable and send an IRQ to the specified node.
+ */
+static void
+xpc_send_activate_IRQ_sn2(unsigned long amos_page_pa, int from_nasid,
+			  int to_nasid, int to_phys_cpuid)
+{
+	struct amo *amos = (struct amo *)__va(amos_page_pa +
+					      (XPC_ACTIVATE_IRQ_AMOS_SN2 *
+					      sizeof(struct amo)));
+
+	(void)xpc_send_IRQ_sn2(&amos[BIT_WORD(from_nasid / 2)],
+			       BIT_MASK(from_nasid / 2), to_nasid,
+			       to_phys_cpuid, SGI_XPC_ACTIVATE);
+}
+
+static void
+xpc_send_local_activate_IRQ_sn2(int from_nasid)
+{
+	unsigned long irq_flags;
+	struct amo *amos = (struct amo *)__va(xpc_vars_sn2->amos_page_pa +
+					      (XPC_ACTIVATE_IRQ_AMOS_SN2 *
+					      sizeof(struct amo)));
+
+	/* fake the sending and receipt of an activate IRQ from remote nasid */
+	FETCHOP_STORE_OP(TO_AMO((u64)&amos[BIT_WORD(from_nasid / 2)].variable),
+			 FETCHOP_OR, BIT_MASK(from_nasid / 2));
+
+	spin_lock_irqsave(&xpc_activate_IRQ_rcvd_lock, irq_flags);
+	xpc_activate_IRQ_rcvd++;
+	spin_unlock_irqrestore(&xpc_activate_IRQ_rcvd_lock, irq_flags);
+
+	wake_up_interruptible(&xpc_activate_IRQ_wq);
+}
+
+/*
+ * Functions associated with SGI_XPC_NOTIFY IRQ.
+ */
+
+/*
+ * Check to see if any chctl flags were sent from the specified partition.
+ */
+static void
+xpc_check_for_sent_chctl_flags_sn2(struct xpc_partition *part)
+{
+	union xpc_channel_ctl_flags chctl;
+	unsigned long irq_flags;
+
+	chctl.all_flags = xpc_receive_IRQ_amo_sn2(part->sn.sn2.
+						  local_chctl_amo_va);
+	if (chctl.all_flags == 0)
+		return;
+
+	spin_lock_irqsave(&part->chctl_lock, irq_flags);
+	part->chctl.all_flags |= chctl.all_flags;
+	spin_unlock_irqrestore(&part->chctl_lock, irq_flags);
+
+	dev_dbg(xpc_chan, "received notify IRQ from partid=%d, chctl.all_flags="
+		"0x%lx\n", XPC_PARTID(part), chctl.all_flags);
+
+	xpc_wakeup_channel_mgr(part);
+}
+
+/*
+ * Handle the receipt of a SGI_XPC_NOTIFY IRQ by seeing whether the specified
+ * partition actually sent it. Since SGI_XPC_NOTIFY IRQs may be shared by more
+ * than one partition, we use an amo structure per partition to indicate
+ * whether a partition has sent an IRQ or not.  If it has, then wake up the
+ * associated kthread to handle it.
+ *
+ * All SGI_XPC_NOTIFY IRQs received by XPC are the result of IRQs sent by XPC
+ * running on other partitions.
+ *
+ * Noteworthy Arguments:
+ *
+ *	irq - Interrupt ReQuest number. NOT USED.
+ *
+ *	dev_id - partid of IRQ's potential sender.
+ */
+static irqreturn_t
+xpc_handle_notify_IRQ_sn2(int irq, void *dev_id)
+{
+	short partid = (short)(u64)dev_id;
+	struct xpc_partition *part = &xpc_partitions[partid];
+
+	DBUG_ON(partid < 0 || partid >= XP_MAX_NPARTITIONS_SN2);
+
+	if (xpc_part_ref(part)) {
+		xpc_check_for_sent_chctl_flags_sn2(part);
+
+		xpc_part_deref(part);
+	}
+	return IRQ_HANDLED;
+}
+
+/*
+ * Check to see if xpc_handle_notify_IRQ_sn2() dropped any IRQs on the floor
+ * because the write to their associated amo variable completed after the IRQ
+ * was received.
+ */
+static void
+xpc_check_for_dropped_notify_IRQ_sn2(struct xpc_partition *part)
+{
+	struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
+
+	if (xpc_part_ref(part)) {
+		xpc_check_for_sent_chctl_flags_sn2(part);
+
+		part_sn2->dropped_notify_IRQ_timer.expires = jiffies +
+		    XPC_DROPPED_NOTIFY_IRQ_WAIT_INTERVAL;
+		add_timer(&part_sn2->dropped_notify_IRQ_timer);
+		xpc_part_deref(part);
+	}
+}
+
+/*
+ * Send a notify IRQ to the remote partition that is associated with the
+ * specified channel.
+ */
+static void
+xpc_send_notify_IRQ_sn2(struct xpc_channel *ch, u8 chctl_flag,
+			char *chctl_flag_string, unsigned long *irq_flags)
+{
+	struct xpc_partition *part = &xpc_partitions[ch->partid];
+	struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
+	union xpc_channel_ctl_flags chctl = { 0 };
+	enum xp_retval ret;
+
+	if (likely(part->act_state != XPC_P_AS_DEACTIVATING)) {
+		chctl.flags[ch->number] = chctl_flag;
+		ret = xpc_send_IRQ_sn2(part_sn2->remote_chctl_amo_va,
+				       chctl.all_flags,
+				       part_sn2->notify_IRQ_nasid,
+				       part_sn2->notify_IRQ_phys_cpuid,
+				       SGI_XPC_NOTIFY);
+		dev_dbg(xpc_chan, "%s sent to partid=%d, channel=%d, ret=%d\n",
+			chctl_flag_string, ch->partid, ch->number, ret);
+		if (unlikely(ret != xpSuccess)) {
+			if (irq_flags != NULL)
+				spin_unlock_irqrestore(&ch->lock, *irq_flags);
+			XPC_DEACTIVATE_PARTITION(part, ret);
+			if (irq_flags != NULL)
+				spin_lock_irqsave(&ch->lock, *irq_flags);
+		}
+	}
+}
+
+#define XPC_SEND_NOTIFY_IRQ_SN2(_ch, _ipi_f, _irq_f) \
+		xpc_send_notify_IRQ_sn2(_ch, _ipi_f, #_ipi_f, _irq_f)
+
+/*
+ * Make it look like the remote partition, which is associated with the
+ * specified channel, sent us a notify IRQ. This faked IRQ will be handled
+ * by xpc_check_for_dropped_notify_IRQ_sn2().
+ */
+static void
+xpc_send_local_notify_IRQ_sn2(struct xpc_channel *ch, u8 chctl_flag,
+			      char *chctl_flag_string)
+{
+	struct xpc_partition *part = &xpc_partitions[ch->partid];
+	union xpc_channel_ctl_flags chctl = { 0 };
+
+	chctl.flags[ch->number] = chctl_flag;
+	FETCHOP_STORE_OP(TO_AMO((u64)&part->sn.sn2.local_chctl_amo_va->
+				variable), FETCHOP_OR, chctl.all_flags);
+	dev_dbg(xpc_chan, "%s sent local from partid=%d, channel=%d\n",
+		chctl_flag_string, ch->partid, ch->number);
+}
+
+#define XPC_SEND_LOCAL_NOTIFY_IRQ_SN2(_ch, _ipi_f) \
+		xpc_send_local_notify_IRQ_sn2(_ch, _ipi_f, #_ipi_f)
+
+static void
+xpc_send_chctl_closerequest_sn2(struct xpc_channel *ch,
+				unsigned long *irq_flags)
+{
+	struct xpc_openclose_args *args = ch->sn.sn2.local_openclose_args;
+
+	args->reason = ch->reason;
+	XPC_SEND_NOTIFY_IRQ_SN2(ch, XPC_CHCTL_CLOSEREQUEST, irq_flags);
+}
+
+static void
+xpc_send_chctl_closereply_sn2(struct xpc_channel *ch, unsigned long *irq_flags)
+{
+	XPC_SEND_NOTIFY_IRQ_SN2(ch, XPC_CHCTL_CLOSEREPLY, irq_flags);
+}
+
+static void
+xpc_send_chctl_openrequest_sn2(struct xpc_channel *ch, unsigned long *irq_flags)
+{
+	struct xpc_openclose_args *args = ch->sn.sn2.local_openclose_args;
+
+	args->entry_size = ch->entry_size;
+	args->local_nentries = ch->local_nentries;
+	XPC_SEND_NOTIFY_IRQ_SN2(ch, XPC_CHCTL_OPENREQUEST, irq_flags);
+}
+
+static void
+xpc_send_chctl_openreply_sn2(struct xpc_channel *ch, unsigned long *irq_flags)
+{
+	struct xpc_openclose_args *args = ch->sn.sn2.local_openclose_args;
+
+	args->remote_nentries = ch->remote_nentries;
+	args->local_nentries = ch->local_nentries;
+	args->local_msgqueue_pa = xp_pa(ch->sn.sn2.local_msgqueue);
+	XPC_SEND_NOTIFY_IRQ_SN2(ch, XPC_CHCTL_OPENREPLY, irq_flags);
+}
+
+static void
+xpc_send_chctl_msgrequest_sn2(struct xpc_channel *ch)
+{
+	XPC_SEND_NOTIFY_IRQ_SN2(ch, XPC_CHCTL_MSGREQUEST, NULL);
+}
+
+static void
+xpc_send_chctl_local_msgrequest_sn2(struct xpc_channel *ch)
+{
+	XPC_SEND_LOCAL_NOTIFY_IRQ_SN2(ch, XPC_CHCTL_MSGREQUEST);
+}
+
+static void
+xpc_save_remote_msgqueue_pa_sn2(struct xpc_channel *ch,
+				unsigned long msgqueue_pa)
+{
+	ch->sn.sn2.remote_msgqueue_pa = msgqueue_pa;
+}
+
+/*
+ * This next set of functions are used to keep track of when a partition is
+ * potentially engaged in accessing memory belonging to another partition.
+ */
+
+static void
+xpc_indicate_partition_engaged_sn2(struct xpc_partition *part)
+{
+	unsigned long irq_flags;
+	struct amo *amo = (struct amo *)__va(part->sn.sn2.remote_amos_page_pa +
+					     (XPC_ENGAGED_PARTITIONS_AMO_SN2 *
+					     sizeof(struct amo)));
+
+	local_irq_save(irq_flags);
+
+	/* set bit corresponding to our partid in remote partition's amo */
+	FETCHOP_STORE_OP(TO_AMO((u64)&amo->variable), FETCHOP_OR,
+			 BIT(sn_partition_id));
+
+	/*
+	 * We must always use the nofault function regardless of whether we
+	 * are on a Shub 1.1 system or a Shub 1.2 slice 0xc processor. If we
+	 * didn't, we'd never know that the other partition is down and would
+	 * keep sending IRQs and amos to it until the heartbeat times out.
+	 */
+	(void)xp_nofault_PIOR((u64 *)GLOBAL_MMR_ADDR(NASID_GET(&amo->
+							       variable),
+						     xp_nofault_PIOR_target));
+
+	local_irq_restore(irq_flags);
+}
+
+static void
+xpc_indicate_partition_disengaged_sn2(struct xpc_partition *part)
+{
+	struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
+	unsigned long irq_flags;
+	struct amo *amo = (struct amo *)__va(part_sn2->remote_amos_page_pa +
+					     (XPC_ENGAGED_PARTITIONS_AMO_SN2 *
+					     sizeof(struct amo)));
+
+	local_irq_save(irq_flags);
+
+	/* clear bit corresponding to our partid in remote partition's amo */
+	FETCHOP_STORE_OP(TO_AMO((u64)&amo->variable), FETCHOP_AND,
+			 ~BIT(sn_partition_id));
+
+	/*
+	 * We must always use the nofault function regardless of whether we
+	 * are on a Shub 1.1 system or a Shub 1.2 slice 0xc processor. If we
+	 * didn't, we'd never know that the other partition is down and would
+	 * keep sending IRQs and amos to it until the heartbeat times out.
+	 */
+	(void)xp_nofault_PIOR((u64 *)GLOBAL_MMR_ADDR(NASID_GET(&amo->
+							       variable),
+						     xp_nofault_PIOR_target));
+
+	local_irq_restore(irq_flags);
+
+	/*
+	 * Send activate IRQ to get other side to see that we've cleared our
+	 * bit in their engaged partitions amo.
+	 */
+	xpc_send_activate_IRQ_sn2(part_sn2->remote_amos_page_pa,
+				  cnodeid_to_nasid(0),
+				  part_sn2->activate_IRQ_nasid,
+				  part_sn2->activate_IRQ_phys_cpuid);
+}
+
+static void
+xpc_assume_partition_disengaged_sn2(short partid)
+{
+	struct amo *amo = xpc_vars_sn2->amos_page +
+			  XPC_ENGAGED_PARTITIONS_AMO_SN2;
+
+	/* clear bit(s) based on partid mask in our partition's amo */
+	FETCHOP_STORE_OP(TO_AMO((u64)&amo->variable), FETCHOP_AND,
+			 ~BIT(partid));
+}
+
+static int
+xpc_partition_engaged_sn2(short partid)
+{
+	struct amo *amo = xpc_vars_sn2->amos_page +
+			  XPC_ENGAGED_PARTITIONS_AMO_SN2;
+
+	/* our partition's amo variable ANDed with partid mask */
+	return (FETCHOP_LOAD_OP(TO_AMO((u64)&amo->variable), FETCHOP_LOAD) &
+		BIT(partid)) != 0;
+}
+
+static int
+xpc_any_partition_engaged_sn2(void)
+{
+	struct amo *amo = xpc_vars_sn2->amos_page +
+			  XPC_ENGAGED_PARTITIONS_AMO_SN2;
+
+	/* our partition's amo variable */
+	return FETCHOP_LOAD_OP(TO_AMO((u64)&amo->variable), FETCHOP_LOAD) != 0;
+}
+
+/* original protection values for each node */
+static u64 xpc_prot_vec_sn2[MAX_NUMNODES];
+
+/*
+ * Change protections to allow amo operations on non-Shub 1.1 systems.
+ */
+static enum xp_retval
+xpc_allow_amo_ops_sn2(struct amo *amos_page)
+{
+	u64 nasid_array = 0;
+	int ret;
+
+	/*
+	 * On SHUB 1.1, we cannot call sn_change_memprotect() since the BIST
+	 * collides with memory operations. On those systems we call
+	 * xpc_allow_amo_ops_shub_wars_1_1_sn2() instead.
+	 */
+	if (!enable_shub_wars_1_1()) {
+		ret = sn_change_memprotect(ia64_tpa((u64)amos_page), PAGE_SIZE,
+					   SN_MEMPROT_ACCESS_CLASS_1,
+					   &nasid_array);
+		if (ret != 0)
+			return xpSalError;
+	}
+	return xpSuccess;
+}
+
+/*
+ * Change protections to allow amo operations on Shub 1.1 systems.
+ */
+static void
+xpc_allow_amo_ops_shub_wars_1_1_sn2(void)
+{
+	int node;
+	int nasid;
+
+	if (!enable_shub_wars_1_1())
+		return;
+
+	for_each_online_node(node) {
+		nasid = cnodeid_to_nasid(node);
+		/* save current protection values */
+		xpc_prot_vec_sn2[node] =
+		    (u64)HUB_L((u64 *)GLOBAL_MMR_ADDR(nasid,
+						  SH1_MD_DQLP_MMR_DIR_PRIVEC0));
+		/* open up everything */
+		HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid,
+					     SH1_MD_DQLP_MMR_DIR_PRIVEC0),
+		      -1UL);
+		HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid,
+					     SH1_MD_DQRP_MMR_DIR_PRIVEC0),
+		      -1UL);
+	}
+}
+
+static enum xp_retval
+xpc_get_partition_rsvd_page_pa_sn2(void *buf, u64 *cookie, unsigned long *rp_pa,
+				   size_t *len)
+{
+	s64 status;
+	enum xp_retval ret;
+
+	status = sn_partition_reserved_page_pa((u64)buf, cookie, rp_pa, len);
+	if (status == SALRET_OK)
+		ret = xpSuccess;
+	else if (status == SALRET_MORE_PASSES)
+		ret = xpNeedMoreInfo;
+	else
+		ret = xpSalError;
+
+	return ret;
+}
+
+
+static int
+xpc_setup_rsvd_page_sn_sn2(struct xpc_rsvd_page *rp)
+{
+	struct amo *amos_page;
+	int i;
+	int ret;
+
+	xpc_vars_sn2 = XPC_RP_VARS(rp);
+
+	rp->sn.vars_pa = xp_pa(xpc_vars_sn2);
+
+	/* vars_part array follows immediately after vars */
+	xpc_vars_part_sn2 = (struct xpc_vars_part_sn2 *)((u8 *)XPC_RP_VARS(rp) +
+							 XPC_RP_VARS_SIZE);
+
+	/*
+	 * Before clearing xpc_vars_sn2, see if a page of amos had been
+	 * previously allocated. If not we'll need to allocate one and set
+	 * permissions so that cross-partition amos are allowed.
+	 *
+	 * The allocated amo page needs MCA reporting to remain disabled after
+	 * XPC has unloaded.  To make this work, we keep a copy of the pointer
+	 * to this page (i.e., amos_page) in the struct xpc_vars_sn2 structure,
+	 * which is pointed to by the reserved page, and re-use that saved copy
+	 * on subsequent loads of XPC. This amo page is never freed, and its
+	 * memory protections are never restricted.
+	 */
+	amos_page = xpc_vars_sn2->amos_page;
+	if (amos_page == NULL) {
+		amos_page = (struct amo *)TO_AMO(uncached_alloc_page(0, 1));
+		if (amos_page == NULL) {
+			dev_err(xpc_part, "can't allocate page of amos\n");
+			return -ENOMEM;
+		}
+
+		/*
+		 * Open up amo-R/W to cpu.  This is done on Shub 1.1 systems
+		 * when xpc_allow_amo_ops_shub_wars_1_1_sn2() is called.
+		 */
+		ret = xpc_allow_amo_ops_sn2(amos_page);
+		if (ret != xpSuccess) {
+			dev_err(xpc_part, "can't allow amo operations\n");
+			uncached_free_page(__IA64_UNCACHED_OFFSET |
+					   TO_PHYS((u64)amos_page), 1);
+			return -EPERM;
+		}
+	}
+
+	/* clear xpc_vars_sn2 */
+	memset(xpc_vars_sn2, 0, sizeof(struct xpc_vars_sn2));
+
+	xpc_vars_sn2->version = XPC_V_VERSION;
+	xpc_vars_sn2->activate_IRQ_nasid = cpuid_to_nasid(0);
+	xpc_vars_sn2->activate_IRQ_phys_cpuid = cpu_physical_id(0);
+	xpc_vars_sn2->vars_part_pa = xp_pa(xpc_vars_part_sn2);
+	xpc_vars_sn2->amos_page_pa = ia64_tpa((u64)amos_page);
+	xpc_vars_sn2->amos_page = amos_page;	/* save for next load of XPC */
+
+	/* clear xpc_vars_part_sn2 */
+	memset((u64 *)xpc_vars_part_sn2, 0, sizeof(struct xpc_vars_part_sn2) *
+	       XP_MAX_NPARTITIONS_SN2);
+
+	/* initialize the activate IRQ related amo variables */
+	for (i = 0; i < xpc_nasid_mask_nlongs; i++)
+		(void)xpc_init_IRQ_amo_sn2(XPC_ACTIVATE_IRQ_AMOS_SN2 + i);
+
+	/* initialize the engaged remote partitions related amo variables */
+	(void)xpc_init_IRQ_amo_sn2(XPC_ENGAGED_PARTITIONS_AMO_SN2);
+	(void)xpc_init_IRQ_amo_sn2(XPC_DEACTIVATE_REQUEST_AMO_SN2);
+
+	return 0;
+}
+
+static void
+xpc_increment_heartbeat_sn2(void)
+{
+	xpc_vars_sn2->heartbeat++;
+}
+
+static void
+xpc_offline_heartbeat_sn2(void)
+{
+	xpc_increment_heartbeat_sn2();
+	xpc_vars_sn2->heartbeat_offline = 1;
+}
+
+static void
+xpc_online_heartbeat_sn2(void)
+{
+	xpc_increment_heartbeat_sn2();
+	xpc_vars_sn2->heartbeat_offline = 0;
+}
+
+static void
+xpc_heartbeat_init_sn2(void)
+{
+	DBUG_ON(xpc_vars_sn2 == NULL);
+
+	bitmap_zero(xpc_vars_sn2->heartbeating_to_mask, XP_MAX_NPARTITIONS_SN2);
+	xpc_heartbeating_to_mask = &xpc_vars_sn2->heartbeating_to_mask[0];
+	xpc_online_heartbeat_sn2();
+}
+
+static void
+xpc_heartbeat_exit_sn2(void)
+{
+	xpc_offline_heartbeat_sn2();
+}
+
+static enum xp_retval
+xpc_get_remote_heartbeat_sn2(struct xpc_partition *part)
+{
+	struct xpc_vars_sn2 *remote_vars;
+	enum xp_retval ret;
+
+	remote_vars = (struct xpc_vars_sn2 *)xpc_remote_copy_buffer_sn2;
+
+	/* pull the remote vars structure that contains the heartbeat */
+	ret = xp_remote_memcpy(xp_pa(remote_vars),
+			       part->sn.sn2.remote_vars_pa,
+			       XPC_RP_VARS_SIZE);
+	if (ret != xpSuccess)
+		return ret;
+
+	dev_dbg(xpc_part, "partid=%d, heartbeat=%ld, last_heartbeat=%ld, "
+		"heartbeat_offline=%ld, HB_mask[0]=0x%lx\n", XPC_PARTID(part),
+		remote_vars->heartbeat, part->last_heartbeat,
+		remote_vars->heartbeat_offline,
+		remote_vars->heartbeating_to_mask[0]);
+
+	if ((remote_vars->heartbeat == part->last_heartbeat &&
+	    remote_vars->heartbeat_offline == 0) ||
+	    !xpc_hb_allowed(sn_partition_id,
+			    &remote_vars->heartbeating_to_mask)) {
+		ret = xpNoHeartbeat;
+	} else {
+		part->last_heartbeat = remote_vars->heartbeat;
+	}
+
+	return ret;
+}
+
+/*
+ * Get a copy of the remote partition's XPC variables from the reserved page.
+ *
+ * remote_vars points to a buffer that is cacheline aligned for BTE copies and
+ * assumed to be of size XPC_RP_VARS_SIZE.
+ */
+static enum xp_retval
+xpc_get_remote_vars_sn2(unsigned long remote_vars_pa,
+			struct xpc_vars_sn2 *remote_vars)
+{
+	enum xp_retval ret;
+
+	if (remote_vars_pa == 0)
+		return xpVarsNotSet;
+
+	/* pull over the cross partition variables */
+	ret = xp_remote_memcpy(xp_pa(remote_vars), remote_vars_pa,
+			       XPC_RP_VARS_SIZE);
+	if (ret != xpSuccess)
+		return ret;
+
+	if (XPC_VERSION_MAJOR(remote_vars->version) !=
+	    XPC_VERSION_MAJOR(XPC_V_VERSION)) {
+		return xpBadVersion;
+	}
+
+	return xpSuccess;
+}
+
+static void
+xpc_request_partition_activation_sn2(struct xpc_rsvd_page *remote_rp,
+				     unsigned long remote_rp_pa, int nasid)
+{
+	xpc_send_local_activate_IRQ_sn2(nasid);
+}
+
+static void
+xpc_request_partition_reactivation_sn2(struct xpc_partition *part)
+{
+	xpc_send_local_activate_IRQ_sn2(part->sn.sn2.activate_IRQ_nasid);
+}
+
+static void
+xpc_request_partition_deactivation_sn2(struct xpc_partition *part)
+{
+	struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
+	unsigned long irq_flags;
+	struct amo *amo = (struct amo *)__va(part_sn2->remote_amos_page_pa +
+					     (XPC_DEACTIVATE_REQUEST_AMO_SN2 *
+					     sizeof(struct amo)));
+
+	local_irq_save(irq_flags);
+
+	/* set bit corresponding to our partid in remote partition's amo */
+	FETCHOP_STORE_OP(TO_AMO((u64)&amo->variable), FETCHOP_OR,
+			 BIT(sn_partition_id));
+
+	/*
+	 * We must always use the nofault function regardless of whether we
+	 * are on a Shub 1.1 system or a Shub 1.2 slice 0xc processor. If we
+	 * didn't, we'd never know that the other partition is down and would
+	 * keep sending IRQs and amos to it until the heartbeat times out.
+	 */
+	(void)xp_nofault_PIOR((u64 *)GLOBAL_MMR_ADDR(NASID_GET(&amo->
+							       variable),
+						     xp_nofault_PIOR_target));
+
+	local_irq_restore(irq_flags);
+
+	/*
+	 * Send activate IRQ to get other side to see that we've set our
+	 * bit in their deactivate request amo.
+	 */
+	xpc_send_activate_IRQ_sn2(part_sn2->remote_amos_page_pa,
+				  cnodeid_to_nasid(0),
+				  part_sn2->activate_IRQ_nasid,
+				  part_sn2->activate_IRQ_phys_cpuid);
+}
+
+static void
+xpc_cancel_partition_deactivation_request_sn2(struct xpc_partition *part)
+{
+	unsigned long irq_flags;
+	struct amo *amo = (struct amo *)__va(part->sn.sn2.remote_amos_page_pa +
+					     (XPC_DEACTIVATE_REQUEST_AMO_SN2 *
+					     sizeof(struct amo)));
+
+	local_irq_save(irq_flags);
+
+	/* clear bit corresponding to our partid in remote partition's amo */
+	FETCHOP_STORE_OP(TO_AMO((u64)&amo->variable), FETCHOP_AND,
+			 ~BIT(sn_partition_id));
+
+	/*
+	 * We must always use the nofault function regardless of whether we
+	 * are on a Shub 1.1 system or a Shub 1.2 slice 0xc processor. If we
+	 * didn't, we'd never know that the other partition is down and would
+	 * keep sending IRQs and amos to it until the heartbeat times out.
+	 */
+	(void)xp_nofault_PIOR((u64 *)GLOBAL_MMR_ADDR(NASID_GET(&amo->
+							       variable),
+						     xp_nofault_PIOR_target));
+
+	local_irq_restore(irq_flags);
+}
+
+static int
+xpc_partition_deactivation_requested_sn2(short partid)
+{
+	struct amo *amo = xpc_vars_sn2->amos_page +
+			  XPC_DEACTIVATE_REQUEST_AMO_SN2;
+
+	/* our partition's amo variable ANDed with partid mask */
+	return (FETCHOP_LOAD_OP(TO_AMO((u64)&amo->variable), FETCHOP_LOAD) &
+		BIT(partid)) != 0;
+}
+
+/*
+ * Update the remote partition's info.
+ */
+static void
+xpc_update_partition_info_sn2(struct xpc_partition *part, u8 remote_rp_version,
+			      unsigned long *remote_rp_ts_jiffies,
+			      unsigned long remote_rp_pa,
+			      unsigned long remote_vars_pa,
+			      struct xpc_vars_sn2 *remote_vars)
+{
+	struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
+
+	part->remote_rp_version = remote_rp_version;
+	dev_dbg(xpc_part, "  remote_rp_version = 0x%016x\n",
+		part->remote_rp_version);
+
+	part->remote_rp_ts_jiffies = *remote_rp_ts_jiffies;
+	dev_dbg(xpc_part, "  remote_rp_ts_jiffies = 0x%016lx\n",
+		part->remote_rp_ts_jiffies);
+
+	part->remote_rp_pa = remote_rp_pa;
+	dev_dbg(xpc_part, "  remote_rp_pa = 0x%016lx\n", part->remote_rp_pa);
+
+	part_sn2->remote_vars_pa = remote_vars_pa;
+	dev_dbg(xpc_part, "  remote_vars_pa = 0x%016lx\n",
+		part_sn2->remote_vars_pa);
+
+	part->last_heartbeat = remote_vars->heartbeat;
+	dev_dbg(xpc_part, "  last_heartbeat = 0x%016lx\n",
+		part->last_heartbeat);
+
+	part_sn2->remote_vars_part_pa = remote_vars->vars_part_pa;
+	dev_dbg(xpc_part, "  remote_vars_part_pa = 0x%016lx\n",
+		part_sn2->remote_vars_part_pa);
+
+	part_sn2->activate_IRQ_nasid = remote_vars->activate_IRQ_nasid;
+	dev_dbg(xpc_part, "  activate_IRQ_nasid = 0x%x\n",
+		part_sn2->activate_IRQ_nasid);
+
+	part_sn2->activate_IRQ_phys_cpuid =
+	    remote_vars->activate_IRQ_phys_cpuid;
+	dev_dbg(xpc_part, "  activate_IRQ_phys_cpuid = 0x%x\n",
+		part_sn2->activate_IRQ_phys_cpuid);
+
+	part_sn2->remote_amos_page_pa = remote_vars->amos_page_pa;
+	dev_dbg(xpc_part, "  remote_amos_page_pa = 0x%lx\n",
+		part_sn2->remote_amos_page_pa);
+
+	part_sn2->remote_vars_version = remote_vars->version;
+	dev_dbg(xpc_part, "  remote_vars_version = 0x%x\n",
+		part_sn2->remote_vars_version);
+}
+
+/*
+ * Prior code has determined the nasid which generated a activate IRQ.
+ * Inspect that nasid to determine if its partition needs to be activated
+ * or deactivated.
+ *
+ * A partition is considered "awaiting activation" if our partition
+ * flags indicate it is not active and it has a heartbeat.  A
+ * partition is considered "awaiting deactivation" if our partition
+ * flags indicate it is active but it has no heartbeat or it is not
+ * sending its heartbeat to us.
+ *
+ * To determine the heartbeat, the remote nasid must have a properly
+ * initialized reserved page.
+ */
+static void
+xpc_identify_activate_IRQ_req_sn2(int nasid)
+{
+	struct xpc_rsvd_page *remote_rp;
+	struct xpc_vars_sn2 *remote_vars;
+	unsigned long remote_rp_pa;
+	unsigned long remote_vars_pa;
+	int remote_rp_version;
+	int reactivate = 0;
+	unsigned long remote_rp_ts_jiffies = 0;
+	short partid;
+	struct xpc_partition *part;
+	struct xpc_partition_sn2 *part_sn2;
+	enum xp_retval ret;
+
+	/* pull over the reserved page structure */
+
+	remote_rp = (struct xpc_rsvd_page *)xpc_remote_copy_buffer_sn2;
+
+	ret = xpc_get_remote_rp(nasid, NULL, remote_rp, &remote_rp_pa);
+	if (ret != xpSuccess) {
+		dev_warn(xpc_part, "unable to get reserved page from nasid %d, "
+			 "which sent interrupt, reason=%d\n", nasid, ret);
+		return;
+	}
+
+	remote_vars_pa = remote_rp->sn.vars_pa;
+	remote_rp_version = remote_rp->version;
+	remote_rp_ts_jiffies = remote_rp->ts_jiffies;
+
+	partid = remote_rp->SAL_partid;
+	part = &xpc_partitions[partid];
+	part_sn2 = &part->sn.sn2;
+
+	/* pull over the cross partition variables */
+
+	remote_vars = (struct xpc_vars_sn2 *)xpc_remote_copy_buffer_sn2;
+
+	ret = xpc_get_remote_vars_sn2(remote_vars_pa, remote_vars);
+	if (ret != xpSuccess) {
+		dev_warn(xpc_part, "unable to get XPC variables from nasid %d, "
+			 "which sent interrupt, reason=%d\n", nasid, ret);
+
+		XPC_DEACTIVATE_PARTITION(part, ret);
+		return;
+	}
+
+	part->activate_IRQ_rcvd++;
+
+	dev_dbg(xpc_part, "partid for nasid %d is %d; IRQs = %d; HB = "
+		"%ld:0x%lx\n", (int)nasid, (int)partid, part->activate_IRQ_rcvd,
+		remote_vars->heartbeat, remote_vars->heartbeating_to_mask[0]);
+
+	if (xpc_partition_disengaged(part) &&
+	    part->act_state == XPC_P_AS_INACTIVE) {
+
+		xpc_update_partition_info_sn2(part, remote_rp_version,
+					      &remote_rp_ts_jiffies,
+					      remote_rp_pa, remote_vars_pa,
+					      remote_vars);
+
+		if (xpc_partition_deactivation_requested_sn2(partid)) {
+			/*
+			 * Other side is waiting on us to deactivate even though
+			 * we already have.
+			 */
+			return;
+		}
+
+		xpc_activate_partition(part);
+		return;
+	}
+
+	DBUG_ON(part->remote_rp_version == 0);
+	DBUG_ON(part_sn2->remote_vars_version == 0);
+
+	if (remote_rp_ts_jiffies != part->remote_rp_ts_jiffies) {
+
+		/* the other side rebooted */
+
+		DBUG_ON(xpc_partition_engaged_sn2(partid));
+		DBUG_ON(xpc_partition_deactivation_requested_sn2(partid));
+
+		xpc_update_partition_info_sn2(part, remote_rp_version,
+					      &remote_rp_ts_jiffies,
+					      remote_rp_pa, remote_vars_pa,
+					      remote_vars);
+		reactivate = 1;
+	}
+
+	if (part->disengage_timeout > 0 && !xpc_partition_disengaged(part)) {
+		/* still waiting on other side to disengage from us */
+		return;
+	}
+
+	if (reactivate)
+		XPC_DEACTIVATE_PARTITION(part, xpReactivating);
+	else if (xpc_partition_deactivation_requested_sn2(partid))
+		XPC_DEACTIVATE_PARTITION(part, xpOtherGoingDown);
+}
+
+/*
+ * Loop through the activation amo variables and process any bits
+ * which are set.  Each bit indicates a nasid sending a partition
+ * activation or deactivation request.
+ *
+ * Return #of IRQs detected.
+ */
+int
+xpc_identify_activate_IRQ_sender_sn2(void)
+{
+	int l;
+	int b;
+	unsigned long nasid_mask_long;
+	u64 nasid;		/* remote nasid */
+	int n_IRQs_detected = 0;
+	struct amo *act_amos;
+
+	act_amos = xpc_vars_sn2->amos_page + XPC_ACTIVATE_IRQ_AMOS_SN2;
+
+	/* scan through activate amo variables looking for non-zero entries */
+	for (l = 0; l < xpc_nasid_mask_nlongs; l++) {
+
+		if (xpc_exiting)
+			break;
+
+		nasid_mask_long = xpc_receive_IRQ_amo_sn2(&act_amos[l]);
+
+		b = find_first_bit(&nasid_mask_long, BITS_PER_LONG);
+		if (b >= BITS_PER_LONG) {
+			/* no IRQs from nasids in this amo variable */
+			continue;
+		}
+
+		dev_dbg(xpc_part, "amo[%d] gave back 0x%lx\n", l,
+			nasid_mask_long);
+
+		/*
+		 * If this nasid has been added to the machine since
+		 * our partition was reset, this will retain the
+		 * remote nasid in our reserved pages machine mask.
+		 * This is used in the event of module reload.
+		 */
+		xpc_mach_nasids[l] |= nasid_mask_long;
+
+		/* locate the nasid(s) which sent interrupts */
+
+		do {
+			n_IRQs_detected++;
+			nasid = (l * BITS_PER_LONG + b) * 2;
+			dev_dbg(xpc_part, "interrupt from nasid %ld\n", nasid);
+			xpc_identify_activate_IRQ_req_sn2(nasid);
+
+			b = find_next_bit(&nasid_mask_long, BITS_PER_LONG,
+					  b + 1);
+		} while (b < BITS_PER_LONG);
+	}
+	return n_IRQs_detected;
+}
+
+static void
+xpc_process_activate_IRQ_rcvd_sn2(void)
+{
+	unsigned long irq_flags;
+	int n_IRQs_expected;
+	int n_IRQs_detected;
+
+	DBUG_ON(xpc_activate_IRQ_rcvd == 0);
+
+	spin_lock_irqsave(&xpc_activate_IRQ_rcvd_lock, irq_flags);
+	n_IRQs_expected = xpc_activate_IRQ_rcvd;
+	xpc_activate_IRQ_rcvd = 0;
+	spin_unlock_irqrestore(&xpc_activate_IRQ_rcvd_lock, irq_flags);
+
+	n_IRQs_detected = xpc_identify_activate_IRQ_sender_sn2();
+	if (n_IRQs_detected < n_IRQs_expected) {
+		/* retry once to help avoid missing amo */
+		(void)xpc_identify_activate_IRQ_sender_sn2();
+	}
+}
+
+/*
+ * Setup the channel structures that are sn2 specific.
+ */
+static enum xp_retval
+xpc_setup_ch_structures_sn_sn2(struct xpc_partition *part)
+{
+	struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
+	struct xpc_channel_sn2 *ch_sn2;
+	enum xp_retval retval;
+	int ret;
+	int cpuid;
+	int ch_number;
+	struct timer_list *timer;
+	short partid = XPC_PARTID(part);
+
+	/* allocate all the required GET/PUT values */
+
+	part_sn2->local_GPs =
+	    xpc_kzalloc_cacheline_aligned(XPC_GP_SIZE, GFP_KERNEL,
+					  &part_sn2->local_GPs_base);
+	if (part_sn2->local_GPs == NULL) {
+		dev_err(xpc_chan, "can't get memory for local get/put "
+			"values\n");
+		return xpNoMemory;
+	}
+
+	part_sn2->remote_GPs =
+	    xpc_kzalloc_cacheline_aligned(XPC_GP_SIZE, GFP_KERNEL,
+					  &part_sn2->remote_GPs_base);
+	if (part_sn2->remote_GPs == NULL) {
+		dev_err(xpc_chan, "can't get memory for remote get/put "
+			"values\n");
+		retval = xpNoMemory;
+		goto out_1;
+	}
+
+	part_sn2->remote_GPs_pa = 0;
+
+	/* allocate all the required open and close args */
+
+	part_sn2->local_openclose_args =
+	    xpc_kzalloc_cacheline_aligned(XPC_OPENCLOSE_ARGS_SIZE,
+					  GFP_KERNEL, &part_sn2->
+					  local_openclose_args_base);
+	if (part_sn2->local_openclose_args == NULL) {
+		dev_err(xpc_chan, "can't get memory for local connect args\n");
+		retval = xpNoMemory;
+		goto out_2;
+	}
+
+	part_sn2->remote_openclose_args_pa = 0;
+
+	part_sn2->local_chctl_amo_va = xpc_init_IRQ_amo_sn2(partid);
+
+	part_sn2->notify_IRQ_nasid = 0;
+	part_sn2->notify_IRQ_phys_cpuid = 0;
+	part_sn2->remote_chctl_amo_va = NULL;
+
+	sprintf(part_sn2->notify_IRQ_owner, "xpc%02d", partid);
+	ret = request_irq(SGI_XPC_NOTIFY, xpc_handle_notify_IRQ_sn2,
+			  IRQF_SHARED, part_sn2->notify_IRQ_owner,
+			  (void *)(u64)partid);
+	if (ret != 0) {
+		dev_err(xpc_chan, "can't register NOTIFY IRQ handler, "
+			"errno=%d\n", -ret);
+		retval = xpLackOfResources;
+		goto out_3;
+	}
+
+	/* Setup a timer to check for dropped notify IRQs */
+	timer = &part_sn2->dropped_notify_IRQ_timer;
+	init_timer(timer);
+	timer->function =
+	    (void (*)(unsigned long))xpc_check_for_dropped_notify_IRQ_sn2;
+	timer->data = (unsigned long)part;
+	timer->expires = jiffies + XPC_DROPPED_NOTIFY_IRQ_WAIT_INTERVAL;
+	add_timer(timer);
+
+	for (ch_number = 0; ch_number < part->nchannels; ch_number++) {
+		ch_sn2 = &part->channels[ch_number].sn.sn2;
+
+		ch_sn2->local_GP = &part_sn2->local_GPs[ch_number];
+		ch_sn2->local_openclose_args =
+		    &part_sn2->local_openclose_args[ch_number];
+
+		mutex_init(&ch_sn2->msg_to_pull_mutex);
+	}
+
+	/*
+	 * Setup the per partition specific variables required by the
+	 * remote partition to establish channel connections with us.
+	 *
+	 * The setting of the magic # indicates that these per partition
+	 * specific variables are ready to be used.
+	 */
+	xpc_vars_part_sn2[partid].GPs_pa = xp_pa(part_sn2->local_GPs);
+	xpc_vars_part_sn2[partid].openclose_args_pa =
+	    xp_pa(part_sn2->local_openclose_args);
+	xpc_vars_part_sn2[partid].chctl_amo_pa =
+	    xp_pa(part_sn2->local_chctl_amo_va);
+	cpuid = raw_smp_processor_id();	/* any CPU in this partition will do */
+	xpc_vars_part_sn2[partid].notify_IRQ_nasid = cpuid_to_nasid(cpuid);
+	xpc_vars_part_sn2[partid].notify_IRQ_phys_cpuid =
+	    cpu_physical_id(cpuid);
+	xpc_vars_part_sn2[partid].nchannels = part->nchannels;
+	xpc_vars_part_sn2[partid].magic = XPC_VP_MAGIC1_SN2;
+
+	return xpSuccess;
+
+	/* setup of ch structures failed */
+out_3:
+	kfree(part_sn2->local_openclose_args_base);
+	part_sn2->local_openclose_args = NULL;
+out_2:
+	kfree(part_sn2->remote_GPs_base);
+	part_sn2->remote_GPs = NULL;
+out_1:
+	kfree(part_sn2->local_GPs_base);
+	part_sn2->local_GPs = NULL;
+	return retval;
+}
+
+/*
+ * Teardown the channel structures that are sn2 specific.
+ */
+static void
+xpc_teardown_ch_structures_sn_sn2(struct xpc_partition *part)
+{
+	struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
+	short partid = XPC_PARTID(part);
+
+	/*
+	 * Indicate that the variables specific to the remote partition are no
+	 * longer available for its use.
+	 */
+	xpc_vars_part_sn2[partid].magic = 0;
+
+	/* in case we've still got outstanding timers registered... */
+	del_timer_sync(&part_sn2->dropped_notify_IRQ_timer);
+	free_irq(SGI_XPC_NOTIFY, (void *)(u64)partid);
+
+	kfree(part_sn2->local_openclose_args_base);
+	part_sn2->local_openclose_args = NULL;
+	kfree(part_sn2->remote_GPs_base);
+	part_sn2->remote_GPs = NULL;
+	kfree(part_sn2->local_GPs_base);
+	part_sn2->local_GPs = NULL;
+	part_sn2->local_chctl_amo_va = NULL;
+}
+
+/*
+ * Create a wrapper that hides the underlying mechanism for pulling a cacheline
+ * (or multiple cachelines) from a remote partition.
+ *
+ * src_pa must be a cacheline aligned physical address on the remote partition.
+ * dst must be a cacheline aligned virtual address on this partition.
+ * cnt must be cacheline sized
+ */
+/* ??? Replace this function by call to xp_remote_memcpy() or bte_copy()? */
+static enum xp_retval
+xpc_pull_remote_cachelines_sn2(struct xpc_partition *part, void *dst,
+			       const unsigned long src_pa, size_t cnt)
+{
+	enum xp_retval ret;
+
+	DBUG_ON(src_pa != L1_CACHE_ALIGN(src_pa));
+	DBUG_ON((unsigned long)dst != L1_CACHE_ALIGN((unsigned long)dst));
+	DBUG_ON(cnt != L1_CACHE_ALIGN(cnt));
+
+	if (part->act_state == XPC_P_AS_DEACTIVATING)
+		return part->reason;
+
+	ret = xp_remote_memcpy(xp_pa(dst), src_pa, cnt);
+	if (ret != xpSuccess) {
+		dev_dbg(xpc_chan, "xp_remote_memcpy() from partition %d failed,"
+			" ret=%d\n", XPC_PARTID(part), ret);
+	}
+	return ret;
+}
+
+/*
+ * Pull the remote per partition specific variables from the specified
+ * partition.
+ */
+static enum xp_retval
+xpc_pull_remote_vars_part_sn2(struct xpc_partition *part)
+{
+	struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
+	u8 buffer[L1_CACHE_BYTES * 2];
+	struct xpc_vars_part_sn2 *pulled_entry_cacheline =
+	    (struct xpc_vars_part_sn2 *)L1_CACHE_ALIGN((u64)buffer);
+	struct xpc_vars_part_sn2 *pulled_entry;
+	unsigned long remote_entry_cacheline_pa;
+	unsigned long remote_entry_pa;
+	short partid = XPC_PARTID(part);
+	enum xp_retval ret;
+
+	/* pull the cacheline that contains the variables we're interested in */
+
+	DBUG_ON(part_sn2->remote_vars_part_pa !=
+		L1_CACHE_ALIGN(part_sn2->remote_vars_part_pa));
+	DBUG_ON(sizeof(struct xpc_vars_part_sn2) != L1_CACHE_BYTES / 2);
+
+	remote_entry_pa = part_sn2->remote_vars_part_pa +
+	    sn_partition_id * sizeof(struct xpc_vars_part_sn2);
+
+	remote_entry_cacheline_pa = (remote_entry_pa & ~(L1_CACHE_BYTES - 1));
+
+	pulled_entry = (struct xpc_vars_part_sn2 *)((u64)pulled_entry_cacheline
+						    + (remote_entry_pa &
+						    (L1_CACHE_BYTES - 1)));
+
+	ret = xpc_pull_remote_cachelines_sn2(part, pulled_entry_cacheline,
+					     remote_entry_cacheline_pa,
+					     L1_CACHE_BYTES);
+	if (ret != xpSuccess) {
+		dev_dbg(xpc_chan, "failed to pull XPC vars_part from "
+			"partition %d, ret=%d\n", partid, ret);
+		return ret;
+	}
+
+	/* see if they've been set up yet */
+
+	if (pulled_entry->magic != XPC_VP_MAGIC1_SN2 &&
+	    pulled_entry->magic != XPC_VP_MAGIC2_SN2) {
+
+		if (pulled_entry->magic != 0) {
+			dev_dbg(xpc_chan, "partition %d's XPC vars_part for "
+				"partition %d has bad magic value (=0x%lx)\n",
+				partid, sn_partition_id, pulled_entry->magic);
+			return xpBadMagic;
+		}
+
+		/* they've not been initialized yet */
+		return xpRetry;
+	}
+
+	if (xpc_vars_part_sn2[partid].magic == XPC_VP_MAGIC1_SN2) {
+
+		/* validate the variables */
+
+		if (pulled_entry->GPs_pa == 0 ||
+		    pulled_entry->openclose_args_pa == 0 ||
+		    pulled_entry->chctl_amo_pa == 0) {
+
+			dev_err(xpc_chan, "partition %d's XPC vars_part for "
+				"partition %d are not valid\n", partid,
+				sn_partition_id);
+			return xpInvalidAddress;
+		}
+
+		/* the variables we imported look to be valid */
+
+		part_sn2->remote_GPs_pa = pulled_entry->GPs_pa;
+		part_sn2->remote_openclose_args_pa =
+		    pulled_entry->openclose_args_pa;
+		part_sn2->remote_chctl_amo_va =
+		    (struct amo *)__va(pulled_entry->chctl_amo_pa);
+		part_sn2->notify_IRQ_nasid = pulled_entry->notify_IRQ_nasid;
+		part_sn2->notify_IRQ_phys_cpuid =
+		    pulled_entry->notify_IRQ_phys_cpuid;
+
+		if (part->nchannels > pulled_entry->nchannels)
+			part->nchannels = pulled_entry->nchannels;
+
+		/* let the other side know that we've pulled their variables */
+
+		xpc_vars_part_sn2[partid].magic = XPC_VP_MAGIC2_SN2;
+	}
+
+	if (pulled_entry->magic == XPC_VP_MAGIC1_SN2)
+		return xpRetry;
+
+	return xpSuccess;
+}
+
+/*
+ * Establish first contact with the remote partititon. This involves pulling
+ * the XPC per partition variables from the remote partition and waiting for
+ * the remote partition to pull ours.
+ */
+static enum xp_retval
+xpc_make_first_contact_sn2(struct xpc_partition *part)
+{
+	struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
+	enum xp_retval ret;
+
+	/*
+	 * Register the remote partition's amos with SAL so it can handle
+	 * and cleanup errors within that address range should the remote
+	 * partition go down. We don't unregister this range because it is
+	 * difficult to tell when outstanding writes to the remote partition
+	 * are finished and thus when it is safe to unregister. This should
+	 * not result in wasted space in the SAL xp_addr_region table because
+	 * we should get the same page for remote_amos_page_pa after module
+	 * reloads and system reboots.
+	 */
+	if (sn_register_xp_addr_region(part_sn2->remote_amos_page_pa,
+				       PAGE_SIZE, 1) < 0) {
+		dev_warn(xpc_part, "xpc_activating(%d) failed to register "
+			 "xp_addr region\n", XPC_PARTID(part));
+
+		ret = xpPhysAddrRegFailed;
+		XPC_DEACTIVATE_PARTITION(part, ret);
+		return ret;
+	}
+
+	/*
+	 * Send activate IRQ to get other side to activate if they've not
+	 * already begun to do so.
+	 */
+	xpc_send_activate_IRQ_sn2(part_sn2->remote_amos_page_pa,
+				  cnodeid_to_nasid(0),
+				  part_sn2->activate_IRQ_nasid,
+				  part_sn2->activate_IRQ_phys_cpuid);
+
+	while ((ret = xpc_pull_remote_vars_part_sn2(part)) != xpSuccess) {
+		if (ret != xpRetry) {
+			XPC_DEACTIVATE_PARTITION(part, ret);
+			return ret;
+		}
+
+		dev_dbg(xpc_part, "waiting to make first contact with "
+			"partition %d\n", XPC_PARTID(part));
+
+		/* wait a 1/4 of a second or so */
+		(void)msleep_interruptible(250);
+
+		if (part->act_state == XPC_P_AS_DEACTIVATING)
+			return part->reason;
+	}
+
+	return xpSuccess;
+}
+
+/*
+ * Get the chctl flags and pull the openclose args and/or remote GPs as needed.
+ */
+static u64
+xpc_get_chctl_all_flags_sn2(struct xpc_partition *part)
+{
+	struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
+	unsigned long irq_flags;
+	union xpc_channel_ctl_flags chctl;
+	enum xp_retval ret;
+
+	/*
+	 * See if there are any chctl flags to be handled.
+	 */
+
+	spin_lock_irqsave(&part->chctl_lock, irq_flags);
+	chctl = part->chctl;
+	if (chctl.all_flags != 0)
+		part->chctl.all_flags = 0;
+
+	spin_unlock_irqrestore(&part->chctl_lock, irq_flags);
+
+	if (xpc_any_openclose_chctl_flags_set(&chctl)) {
+		ret = xpc_pull_remote_cachelines_sn2(part, part->
+						     remote_openclose_args,
+						     part_sn2->
+						     remote_openclose_args_pa,
+						     XPC_OPENCLOSE_ARGS_SIZE);
+		if (ret != xpSuccess) {
+			XPC_DEACTIVATE_PARTITION(part, ret);
+
+			dev_dbg(xpc_chan, "failed to pull openclose args from "
+				"partition %d, ret=%d\n", XPC_PARTID(part),
+				ret);
+
+			/* don't bother processing chctl flags anymore */
+			chctl.all_flags = 0;
+		}
+	}
+
+	if (xpc_any_msg_chctl_flags_set(&chctl)) {
+		ret = xpc_pull_remote_cachelines_sn2(part, part_sn2->remote_GPs,
+						     part_sn2->remote_GPs_pa,
+						     XPC_GP_SIZE);
+		if (ret != xpSuccess) {
+			XPC_DEACTIVATE_PARTITION(part, ret);
+
+			dev_dbg(xpc_chan, "failed to pull GPs from partition "
+				"%d, ret=%d\n", XPC_PARTID(part), ret);
+
+			/* don't bother processing chctl flags anymore */
+			chctl.all_flags = 0;
+		}
+	}
+
+	return chctl.all_flags;
+}
+
+/*
+ * Allocate the local message queue and the notify queue.
+ */
+static enum xp_retval
+xpc_allocate_local_msgqueue_sn2(struct xpc_channel *ch)
+{
+	struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
+	unsigned long irq_flags;
+	int nentries;
+	size_t nbytes;
+
+	for (nentries = ch->local_nentries; nentries > 0; nentries--) {
+
+		nbytes = nentries * ch->entry_size;
+		ch_sn2->local_msgqueue =
+		    xpc_kzalloc_cacheline_aligned(nbytes, GFP_KERNEL,
+						  &ch_sn2->local_msgqueue_base);
+		if (ch_sn2->local_msgqueue == NULL)
+			continue;
+
+		nbytes = nentries * sizeof(struct xpc_notify_sn2);
+		ch_sn2->notify_queue = kzalloc(nbytes, GFP_KERNEL);
+		if (ch_sn2->notify_queue == NULL) {
+			kfree(ch_sn2->local_msgqueue_base);
+			ch_sn2->local_msgqueue = NULL;
+			continue;
+		}
+
+		spin_lock_irqsave(&ch->lock, irq_flags);
+		if (nentries < ch->local_nentries) {
+			dev_dbg(xpc_chan, "nentries=%d local_nentries=%d, "
+				"partid=%d, channel=%d\n", nentries,
+				ch->local_nentries, ch->partid, ch->number);
+
+			ch->local_nentries = nentries;
+		}
+		spin_unlock_irqrestore(&ch->lock, irq_flags);
+		return xpSuccess;
+	}
+
+	dev_dbg(xpc_chan, "can't get memory for local message queue and notify "
+		"queue, partid=%d, channel=%d\n", ch->partid, ch->number);
+	return xpNoMemory;
+}
+
+/*
+ * Allocate the cached remote message queue.
+ */
+static enum xp_retval
+xpc_allocate_remote_msgqueue_sn2(struct xpc_channel *ch)
+{
+	struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
+	unsigned long irq_flags;
+	int nentries;
+	size_t nbytes;
+
+	DBUG_ON(ch->remote_nentries <= 0);
+
+	for (nentries = ch->remote_nentries; nentries > 0; nentries--) {
+
+		nbytes = nentries * ch->entry_size;
+		ch_sn2->remote_msgqueue =
+		    xpc_kzalloc_cacheline_aligned(nbytes, GFP_KERNEL, &ch_sn2->
+						  remote_msgqueue_base);
+		if (ch_sn2->remote_msgqueue == NULL)
+			continue;
+
+		spin_lock_irqsave(&ch->lock, irq_flags);
+		if (nentries < ch->remote_nentries) {
+			dev_dbg(xpc_chan, "nentries=%d remote_nentries=%d, "
+				"partid=%d, channel=%d\n", nentries,
+				ch->remote_nentries, ch->partid, ch->number);
+
+			ch->remote_nentries = nentries;
+		}
+		spin_unlock_irqrestore(&ch->lock, irq_flags);
+		return xpSuccess;
+	}
+
+	dev_dbg(xpc_chan, "can't get memory for cached remote message queue, "
+		"partid=%d, channel=%d\n", ch->partid, ch->number);
+	return xpNoMemory;
+}
+
+/*
+ * Allocate message queues and other stuff associated with a channel.
+ *
+ * Note: Assumes all of the channel sizes are filled in.
+ */
+static enum xp_retval
+xpc_setup_msg_structures_sn2(struct xpc_channel *ch)
+{
+	struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
+	enum xp_retval ret;
+
+	DBUG_ON(ch->flags & XPC_C_SETUP);
+
+	ret = xpc_allocate_local_msgqueue_sn2(ch);
+	if (ret == xpSuccess) {
+
+		ret = xpc_allocate_remote_msgqueue_sn2(ch);
+		if (ret != xpSuccess) {
+			kfree(ch_sn2->local_msgqueue_base);
+			ch_sn2->local_msgqueue = NULL;
+			kfree(ch_sn2->notify_queue);
+			ch_sn2->notify_queue = NULL;
+		}
+	}
+	return ret;
+}
+
+/*
+ * Free up message queues and other stuff that were allocated for the specified
+ * channel.
+ */
+static void
+xpc_teardown_msg_structures_sn2(struct xpc_channel *ch)
+{
+	struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
+
+	DBUG_ON(!spin_is_locked(&ch->lock));
+
+	ch_sn2->remote_msgqueue_pa = 0;
+
+	ch_sn2->local_GP->get = 0;
+	ch_sn2->local_GP->put = 0;
+	ch_sn2->remote_GP.get = 0;
+	ch_sn2->remote_GP.put = 0;
+	ch_sn2->w_local_GP.get = 0;
+	ch_sn2->w_local_GP.put = 0;
+	ch_sn2->w_remote_GP.get = 0;
+	ch_sn2->w_remote_GP.put = 0;
+	ch_sn2->next_msg_to_pull = 0;
+
+	if (ch->flags & XPC_C_SETUP) {
+		dev_dbg(xpc_chan, "ch->flags=0x%x, partid=%d, channel=%d\n",
+			ch->flags, ch->partid, ch->number);
+
+		kfree(ch_sn2->local_msgqueue_base);
+		ch_sn2->local_msgqueue = NULL;
+		kfree(ch_sn2->remote_msgqueue_base);
+		ch_sn2->remote_msgqueue = NULL;
+		kfree(ch_sn2->notify_queue);
+		ch_sn2->notify_queue = NULL;
+	}
+}
+
+/*
+ * Notify those who wanted to be notified upon delivery of their message.
+ */
+static void
+xpc_notify_senders_sn2(struct xpc_channel *ch, enum xp_retval reason, s64 put)
+{
+	struct xpc_notify_sn2 *notify;
+	u8 notify_type;
+	s64 get = ch->sn.sn2.w_remote_GP.get - 1;
+
+	while (++get < put && atomic_read(&ch->n_to_notify) > 0) {
+
+		notify = &ch->sn.sn2.notify_queue[get % ch->local_nentries];
+
+		/*
+		 * See if the notify entry indicates it was associated with
+		 * a message who's sender wants to be notified. It is possible
+		 * that it is, but someone else is doing or has done the
+		 * notification.
+		 */
+		notify_type = notify->type;
+		if (notify_type == 0 ||
+		    cmpxchg(&notify->type, notify_type, 0) != notify_type) {
+			continue;
+		}
+
+		DBUG_ON(notify_type != XPC_N_CALL);
+
+		atomic_dec(&ch->n_to_notify);
+
+		if (notify->func != NULL) {
+			dev_dbg(xpc_chan, "notify->func() called, notify=0x%p "
+				"msg_number=%ld partid=%d channel=%d\n",
+				(void *)notify, get, ch->partid, ch->number);
+
+			notify->func(reason, ch->partid, ch->number,
+				     notify->key);
+
+			dev_dbg(xpc_chan, "notify->func() returned, notify=0x%p"
+				" msg_number=%ld partid=%d channel=%d\n",
+				(void *)notify, get, ch->partid, ch->number);
+		}
+	}
+}
+
+static void
+xpc_notify_senders_of_disconnect_sn2(struct xpc_channel *ch)
+{
+	xpc_notify_senders_sn2(ch, ch->reason, ch->sn.sn2.w_local_GP.put);
+}
+
+/*
+ * Clear some of the msg flags in the local message queue.
+ */
+static inline void
+xpc_clear_local_msgqueue_flags_sn2(struct xpc_channel *ch)
+{
+	struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
+	struct xpc_msg_sn2 *msg;
+	s64 get;
+
+	get = ch_sn2->w_remote_GP.get;
+	do {
+		msg = (struct xpc_msg_sn2 *)((u64)ch_sn2->local_msgqueue +
+					     (get % ch->local_nentries) *
+					     ch->entry_size);
+		msg->flags = 0;
+	} while (++get < ch_sn2->remote_GP.get);
+}
+
+/*
+ * Clear some of the msg flags in the remote message queue.
+ */
+static inline void
+xpc_clear_remote_msgqueue_flags_sn2(struct xpc_channel *ch)
+{
+	struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
+	struct xpc_msg_sn2 *msg;
+	s64 put;
+
+	put = ch_sn2->w_remote_GP.put;
+	do {
+		msg = (struct xpc_msg_sn2 *)((u64)ch_sn2->remote_msgqueue +
+					     (put % ch->remote_nentries) *
+					     ch->entry_size);
+		msg->flags = 0;
+	} while (++put < ch_sn2->remote_GP.put);
+}
+
+static int
+xpc_n_of_deliverable_payloads_sn2(struct xpc_channel *ch)
+{
+	return ch->sn.sn2.w_remote_GP.put - ch->sn.sn2.w_local_GP.get;
+}
+
+static void
+xpc_process_msg_chctl_flags_sn2(struct xpc_partition *part, int ch_number)
+{
+	struct xpc_channel *ch = &part->channels[ch_number];
+	struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
+	int npayloads_sent;
+
+	ch_sn2->remote_GP = part->sn.sn2.remote_GPs[ch_number];
+
+	/* See what, if anything, has changed for each connected channel */
+
+	xpc_msgqueue_ref(ch);
+
+	if (ch_sn2->w_remote_GP.get == ch_sn2->remote_GP.get &&
+	    ch_sn2->w_remote_GP.put == ch_sn2->remote_GP.put) {
+		/* nothing changed since GPs were last pulled */
+		xpc_msgqueue_deref(ch);
+		return;
+	}
+
+	if (!(ch->flags & XPC_C_CONNECTED)) {
+		xpc_msgqueue_deref(ch);
+		return;
+	}
+
+	/*
+	 * First check to see if messages recently sent by us have been
+	 * received by the other side. (The remote GET value will have
+	 * changed since we last looked at it.)
+	 */
+
+	if (ch_sn2->w_remote_GP.get != ch_sn2->remote_GP.get) {
+
+		/*
+		 * We need to notify any senders that want to be notified
+		 * that their sent messages have been received by their
+		 * intended recipients. We need to do this before updating
+		 * w_remote_GP.get so that we don't allocate the same message
+		 * queue entries prematurely (see xpc_allocate_msg()).
+		 */
+		if (atomic_read(&ch->n_to_notify) > 0) {
+			/*
+			 * Notify senders that messages sent have been
+			 * received and delivered by the other side.
+			 */
+			xpc_notify_senders_sn2(ch, xpMsgDelivered,
+					       ch_sn2->remote_GP.get);
+		}
+
+		/*
+		 * Clear msg->flags in previously sent messages, so that
+		 * they're ready for xpc_allocate_msg().
+		 */
+		xpc_clear_local_msgqueue_flags_sn2(ch);
+
+		ch_sn2->w_remote_GP.get = ch_sn2->remote_GP.get;
+
+		dev_dbg(xpc_chan, "w_remote_GP.get changed to %ld, partid=%d, "
+			"channel=%d\n", ch_sn2->w_remote_GP.get, ch->partid,
+			ch->number);
+
+		/*
+		 * If anyone was waiting for message queue entries to become
+		 * available, wake them up.
+		 */
+		if (atomic_read(&ch->n_on_msg_allocate_wq) > 0)
+			wake_up(&ch->msg_allocate_wq);
+	}
+
+	/*
+	 * Now check for newly sent messages by the other side. (The remote
+	 * PUT value will have changed since we last looked at it.)
+	 */
+
+	if (ch_sn2->w_remote_GP.put != ch_sn2->remote_GP.put) {
+		/*
+		 * Clear msg->flags in previously received messages, so that
+		 * they're ready for xpc_get_deliverable_payload_sn2().
+		 */
+		xpc_clear_remote_msgqueue_flags_sn2(ch);
+
+		ch_sn2->w_remote_GP.put = ch_sn2->remote_GP.put;
+
+		dev_dbg(xpc_chan, "w_remote_GP.put changed to %ld, partid=%d, "
+			"channel=%d\n", ch_sn2->w_remote_GP.put, ch->partid,
+			ch->number);
+
+		npayloads_sent = xpc_n_of_deliverable_payloads_sn2(ch);
+		if (npayloads_sent > 0) {
+			dev_dbg(xpc_chan, "msgs waiting to be copied and "
+				"delivered=%d, partid=%d, channel=%d\n",
+				npayloads_sent, ch->partid, ch->number);
+
+			if (ch->flags & XPC_C_CONNECTEDCALLOUT_MADE)
+				xpc_activate_kthreads(ch, npayloads_sent);
+		}
+	}
+
+	xpc_msgqueue_deref(ch);
+}
+
+static struct xpc_msg_sn2 *
+xpc_pull_remote_msg_sn2(struct xpc_channel *ch, s64 get)
+{
+	struct xpc_partition *part = &xpc_partitions[ch->partid];
+	struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
+	unsigned long remote_msg_pa;
+	struct xpc_msg_sn2 *msg;
+	u32 msg_index;
+	u32 nmsgs;
+	u64 msg_offset;
+	enum xp_retval ret;
+
+	if (mutex_lock_interruptible(&ch_sn2->msg_to_pull_mutex) != 0) {
+		/* we were interrupted by a signal */
+		return NULL;
+	}
+
+	while (get >= ch_sn2->next_msg_to_pull) {
+
+		/* pull as many messages as are ready and able to be pulled */
+
+		msg_index = ch_sn2->next_msg_to_pull % ch->remote_nentries;
+
+		DBUG_ON(ch_sn2->next_msg_to_pull >= ch_sn2->w_remote_GP.put);
+		nmsgs = ch_sn2->w_remote_GP.put - ch_sn2->next_msg_to_pull;
+		if (msg_index + nmsgs > ch->remote_nentries) {
+			/* ignore the ones that wrap the msg queue for now */
+			nmsgs = ch->remote_nentries - msg_index;
+		}
+
+		msg_offset = msg_index * ch->entry_size;
+		msg = (struct xpc_msg_sn2 *)((u64)ch_sn2->remote_msgqueue +
+		    msg_offset);
+		remote_msg_pa = ch_sn2->remote_msgqueue_pa + msg_offset;
+
+		ret = xpc_pull_remote_cachelines_sn2(part, msg, remote_msg_pa,
+						     nmsgs * ch->entry_size);
+		if (ret != xpSuccess) {
+
+			dev_dbg(xpc_chan, "failed to pull %d msgs starting with"
+				" msg %ld from partition %d, channel=%d, "
+				"ret=%d\n", nmsgs, ch_sn2->next_msg_to_pull,
+				ch->partid, ch->number, ret);
+
+			XPC_DEACTIVATE_PARTITION(part, ret);
+
+			mutex_unlock(&ch_sn2->msg_to_pull_mutex);
+			return NULL;
+		}
+
+		ch_sn2->next_msg_to_pull += nmsgs;
+	}
+
+	mutex_unlock(&ch_sn2->msg_to_pull_mutex);
+
+	/* return the message we were looking for */
+	msg_offset = (get % ch->remote_nentries) * ch->entry_size;
+	msg = (struct xpc_msg_sn2 *)((u64)ch_sn2->remote_msgqueue + msg_offset);
+
+	return msg;
+}
+
+/*
+ * Get the next deliverable message's payload.
+ */
+static void *
+xpc_get_deliverable_payload_sn2(struct xpc_channel *ch)
+{
+	struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
+	struct xpc_msg_sn2 *msg;
+	void *payload = NULL;
+	s64 get;
+
+	do {
+		if (ch->flags & XPC_C_DISCONNECTING)
+			break;
+
+		get = ch_sn2->w_local_GP.get;
+		rmb();	/* guarantee that .get loads before .put */
+		if (get == ch_sn2->w_remote_GP.put)
+			break;
+
+		/* There are messages waiting to be pulled and delivered.
+		 * We need to try to secure one for ourselves. We'll do this
+		 * by trying to increment w_local_GP.get and hope that no one
+		 * else beats us to it. If they do, we'll we'll simply have
+		 * to try again for the next one.
+		 */
+
+		if (cmpxchg(&ch_sn2->w_local_GP.get, get, get + 1) == get) {
+			/* we got the entry referenced by get */
+
+			dev_dbg(xpc_chan, "w_local_GP.get changed to %ld, "
+				"partid=%d, channel=%d\n", get + 1,
+				ch->partid, ch->number);
+
+			/* pull the message from the remote partition */
+
+			msg = xpc_pull_remote_msg_sn2(ch, get);
+
+			DBUG_ON(msg != NULL && msg->number != get);
+			DBUG_ON(msg != NULL && (msg->flags & XPC_M_SN2_DONE));
+			DBUG_ON(msg != NULL && !(msg->flags & XPC_M_SN2_READY));
+
+			payload = &msg->payload;
+			break;
+		}
+
+	} while (1);
+
+	return payload;
+}
+
+/*
+ * Now we actually send the messages that are ready to be sent by advancing
+ * the local message queue's Put value and then send a chctl msgrequest to the
+ * recipient partition.
+ */
+static void
+xpc_send_msgs_sn2(struct xpc_channel *ch, s64 initial_put)
+{
+	struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
+	struct xpc_msg_sn2 *msg;
+	s64 put = initial_put + 1;
+	int send_msgrequest = 0;
+
+	while (1) {
+
+		while (1) {
+			if (put == ch_sn2->w_local_GP.put)
+				break;
+
+			msg = (struct xpc_msg_sn2 *)((u64)ch_sn2->
+						     local_msgqueue + (put %
+						     ch->local_nentries) *
+						     ch->entry_size);
+
+			if (!(msg->flags & XPC_M_SN2_READY))
+				break;
+
+			put++;
+		}
+
+		if (put == initial_put) {
+			/* nothing's changed */
+			break;
+		}
+
+		if (cmpxchg_rel(&ch_sn2->local_GP->put, initial_put, put) !=
+		    initial_put) {
+			/* someone else beat us to it */
+			DBUG_ON(ch_sn2->local_GP->put < initial_put);
+			break;
+		}
+
+		/* we just set the new value of local_GP->put */
+
+		dev_dbg(xpc_chan, "local_GP->put changed to %ld, partid=%d, "
+			"channel=%d\n", put, ch->partid, ch->number);
+
+		send_msgrequest = 1;
+
+		/*
+		 * We need to ensure that the message referenced by
+		 * local_GP->put is not XPC_M_SN2_READY or that local_GP->put
+		 * equals w_local_GP.put, so we'll go have a look.
+		 */
+		initial_put = put;
+	}
+
+	if (send_msgrequest)
+		xpc_send_chctl_msgrequest_sn2(ch);
+}
+
+/*
+ * Allocate an entry for a message from the message queue associated with the
+ * specified channel.
+ */
+static enum xp_retval
+xpc_allocate_msg_sn2(struct xpc_channel *ch, u32 flags,
+		     struct xpc_msg_sn2 **address_of_msg)
+{
+	struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
+	struct xpc_msg_sn2 *msg;
+	enum xp_retval ret;
+	s64 put;
+
+	/*
+	 * Get the next available message entry from the local message queue.
+	 * If none are available, we'll make sure that we grab the latest
+	 * GP values.
+	 */
+	ret = xpTimeout;
+
+	while (1) {
+
+		put = ch_sn2->w_local_GP.put;
+		rmb();	/* guarantee that .put loads before .get */
+		if (put - ch_sn2->w_remote_GP.get < ch->local_nentries) {
+
+			/* There are available message entries. We need to try
+			 * to secure one for ourselves. We'll do this by trying
+			 * to increment w_local_GP.put as long as someone else
+			 * doesn't beat us to it. If they do, we'll have to
+			 * try again.
+			 */
+			if (cmpxchg(&ch_sn2->w_local_GP.put, put, put + 1) ==
+			    put) {
+				/* we got the entry referenced by put */
+				break;
+			}
+			continue;	/* try again */
+		}
+
+		/*
+		 * There aren't any available msg entries at this time.
+		 *
+		 * In waiting for a message entry to become available,
+		 * we set a timeout in case the other side is not sending
+		 * completion interrupts. This lets us fake a notify IRQ
+		 * that will cause the notify IRQ handler to fetch the latest
+		 * GP values as if an interrupt was sent by the other side.
+		 */
+		if (ret == xpTimeout)
+			xpc_send_chctl_local_msgrequest_sn2(ch);
+
+		if (flags & XPC_NOWAIT)
+			return xpNoWait;
+
+		ret = xpc_allocate_msg_wait(ch);
+		if (ret != xpInterrupted && ret != xpTimeout)
+			return ret;
+	}
+
+	/* get the message's address and initialize it */
+	msg = (struct xpc_msg_sn2 *)((u64)ch_sn2->local_msgqueue +
+				     (put % ch->local_nentries) *
+				     ch->entry_size);
+
+	DBUG_ON(msg->flags != 0);
+	msg->number = put;
+
+	dev_dbg(xpc_chan, "w_local_GP.put changed to %ld; msg=0x%p, "
+		"msg_number=%ld, partid=%d, channel=%d\n", put + 1,
+		(void *)msg, msg->number, ch->partid, ch->number);
+
+	*address_of_msg = msg;
+	return xpSuccess;
+}
+
+/*
+ * Common code that does the actual sending of the message by advancing the
+ * local message queue's Put value and sends a chctl msgrequest to the
+ * partition the message is being sent to.
+ */
+static enum xp_retval
+xpc_send_payload_sn2(struct xpc_channel *ch, u32 flags, void *payload,
+		     u16 payload_size, u8 notify_type, xpc_notify_func func,
+		     void *key)
+{
+	enum xp_retval ret = xpSuccess;
+	struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
+	struct xpc_msg_sn2 *msg = msg;
+	struct xpc_notify_sn2 *notify = notify;
+	s64 msg_number;
+	s64 put;
+
+	DBUG_ON(notify_type == XPC_N_CALL && func == NULL);
+
+	if (XPC_MSG_SIZE(payload_size) > ch->entry_size)
+		return xpPayloadTooBig;
+
+	xpc_msgqueue_ref(ch);
+
+	if (ch->flags & XPC_C_DISCONNECTING) {
+		ret = ch->reason;
+		goto out_1;
+	}
+	if (!(ch->flags & XPC_C_CONNECTED)) {
+		ret = xpNotConnected;
+		goto out_1;
+	}
+
+	ret = xpc_allocate_msg_sn2(ch, flags, &msg);
+	if (ret != xpSuccess)
+		goto out_1;
+
+	msg_number = msg->number;
+
+	if (notify_type != 0) {
+		/*
+		 * Tell the remote side to send an ACK interrupt when the
+		 * message has been delivered.
+		 */
+		msg->flags |= XPC_M_SN2_INTERRUPT;
+
+		atomic_inc(&ch->n_to_notify);
+
+		notify = &ch_sn2->notify_queue[msg_number % ch->local_nentries];
+		notify->func = func;
+		notify->key = key;
+		notify->type = notify_type;
+
+		/* ??? Is a mb() needed here? */
+
+		if (ch->flags & XPC_C_DISCONNECTING) {
+			/*
+			 * An error occurred between our last error check and
+			 * this one. We will try to clear the type field from
+			 * the notify entry. If we succeed then
+			 * xpc_disconnect_channel() didn't already process
+			 * the notify entry.
+			 */
+			if (cmpxchg(&notify->type, notify_type, 0) ==
+			    notify_type) {
+				atomic_dec(&ch->n_to_notify);
+				ret = ch->reason;
+			}
+			goto out_1;
+		}
+	}
+
+	memcpy(&msg->payload, payload, payload_size);
+
+	msg->flags |= XPC_M_SN2_READY;
+
+	/*
+	 * The preceding store of msg->flags must occur before the following
+	 * load of local_GP->put.
+	 */
+	mb();
+
+	/* see if the message is next in line to be sent, if so send it */
+
+	put = ch_sn2->local_GP->put;
+	if (put == msg_number)
+		xpc_send_msgs_sn2(ch, put);
+
+out_1:
+	xpc_msgqueue_deref(ch);
+	return ret;
+}
+
+/*
+ * Now we actually acknowledge the messages that have been delivered and ack'd
+ * by advancing the cached remote message queue's Get value and if requested
+ * send a chctl msgrequest to the message sender's partition.
+ *
+ * If a message has XPC_M_SN2_INTERRUPT set, send an interrupt to the partition
+ * that sent the message.
+ */
+static void
+xpc_acknowledge_msgs_sn2(struct xpc_channel *ch, s64 initial_get, u8 msg_flags)
+{
+	struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
+	struct xpc_msg_sn2 *msg;
+	s64 get = initial_get + 1;
+	int send_msgrequest = 0;
+
+	while (1) {
+
+		while (1) {
+			if (get == ch_sn2->w_local_GP.get)
+				break;
+
+			msg = (struct xpc_msg_sn2 *)((u64)ch_sn2->
+						     remote_msgqueue + (get %
+						     ch->remote_nentries) *
+						     ch->entry_size);
+
+			if (!(msg->flags & XPC_M_SN2_DONE))
+				break;
+
+			msg_flags |= msg->flags;
+			get++;
+		}
+
+		if (get == initial_get) {
+			/* nothing's changed */
+			break;
+		}
+
+		if (cmpxchg_rel(&ch_sn2->local_GP->get, initial_get, get) !=
+		    initial_get) {
+			/* someone else beat us to it */
+			DBUG_ON(ch_sn2->local_GP->get <= initial_get);
+			break;
+		}
+
+		/* we just set the new value of local_GP->get */
+
+		dev_dbg(xpc_chan, "local_GP->get changed to %ld, partid=%d, "
+			"channel=%d\n", get, ch->partid, ch->number);
+
+		send_msgrequest = (msg_flags & XPC_M_SN2_INTERRUPT);
+
+		/*
+		 * We need to ensure that the message referenced by
+		 * local_GP->get is not XPC_M_SN2_DONE or that local_GP->get
+		 * equals w_local_GP.get, so we'll go have a look.
+		 */
+		initial_get = get;
+	}
+
+	if (send_msgrequest)
+		xpc_send_chctl_msgrequest_sn2(ch);
+}
+
+static void
+xpc_received_payload_sn2(struct xpc_channel *ch, void *payload)
+{
+	struct xpc_msg_sn2 *msg;
+	s64 msg_number;
+	s64 get;
+
+	msg = container_of(payload, struct xpc_msg_sn2, payload);
+	msg_number = msg->number;
+
+	dev_dbg(xpc_chan, "msg=0x%p, msg_number=%ld, partid=%d, channel=%d\n",
+		(void *)msg, msg_number, ch->partid, ch->number);
+
+	DBUG_ON((((u64)msg - (u64)ch->remote_msgqueue) / ch->entry_size) !=
+		msg_number % ch->remote_nentries);
+	DBUG_ON(msg->flags & XPC_M_SN2_DONE);
+
+	msg->flags |= XPC_M_SN2_DONE;
+
+	/*
+	 * The preceding store of msg->flags must occur before the following
+	 * load of local_GP->get.
+	 */
+	mb();
+
+	/*
+	 * See if this message is next in line to be acknowledged as having
+	 * been delivered.
+	 */
+	get = ch->sn.sn2.local_GP->get;
+	if (get == msg_number)
+		xpc_acknowledge_msgs_sn2(ch, get, msg->flags);
+}
+
+int
+xpc_init_sn2(void)
+{
+	int ret;
+	size_t buf_size;
+
+	xpc_setup_partitions_sn = xpc_setup_partitions_sn_sn2;
+	xpc_get_partition_rsvd_page_pa = xpc_get_partition_rsvd_page_pa_sn2;
+	xpc_setup_rsvd_page_sn = xpc_setup_rsvd_page_sn_sn2;
+	xpc_increment_heartbeat = xpc_increment_heartbeat_sn2;
+	xpc_offline_heartbeat = xpc_offline_heartbeat_sn2;
+	xpc_online_heartbeat = xpc_online_heartbeat_sn2;
+	xpc_heartbeat_init = xpc_heartbeat_init_sn2;
+	xpc_heartbeat_exit = xpc_heartbeat_exit_sn2;
+	xpc_get_remote_heartbeat = xpc_get_remote_heartbeat_sn2;
+
+	xpc_request_partition_activation = xpc_request_partition_activation_sn2;
+	xpc_request_partition_reactivation =
+	    xpc_request_partition_reactivation_sn2;
+	xpc_request_partition_deactivation =
+	    xpc_request_partition_deactivation_sn2;
+	xpc_cancel_partition_deactivation_request =
+	    xpc_cancel_partition_deactivation_request_sn2;
+
+	xpc_process_activate_IRQ_rcvd = xpc_process_activate_IRQ_rcvd_sn2;
+	xpc_setup_ch_structures_sn = xpc_setup_ch_structures_sn_sn2;
+	xpc_teardown_ch_structures_sn = xpc_teardown_ch_structures_sn_sn2;
+	xpc_make_first_contact = xpc_make_first_contact_sn2;
+
+	xpc_get_chctl_all_flags = xpc_get_chctl_all_flags_sn2;
+	xpc_send_chctl_closerequest = xpc_send_chctl_closerequest_sn2;
+	xpc_send_chctl_closereply = xpc_send_chctl_closereply_sn2;
+	xpc_send_chctl_openrequest = xpc_send_chctl_openrequest_sn2;
+	xpc_send_chctl_openreply = xpc_send_chctl_openreply_sn2;
+
+	xpc_save_remote_msgqueue_pa = xpc_save_remote_msgqueue_pa_sn2;
+
+	xpc_setup_msg_structures = xpc_setup_msg_structures_sn2;
+	xpc_teardown_msg_structures = xpc_teardown_msg_structures_sn2;
+
+	xpc_notify_senders_of_disconnect = xpc_notify_senders_of_disconnect_sn2;
+	xpc_process_msg_chctl_flags = xpc_process_msg_chctl_flags_sn2;
+	xpc_n_of_deliverable_payloads = xpc_n_of_deliverable_payloads_sn2;
+	xpc_get_deliverable_payload = xpc_get_deliverable_payload_sn2;
+
+	xpc_indicate_partition_engaged = xpc_indicate_partition_engaged_sn2;
+	xpc_indicate_partition_disengaged =
+	    xpc_indicate_partition_disengaged_sn2;
+	xpc_partition_engaged = xpc_partition_engaged_sn2;
+	xpc_any_partition_engaged = xpc_any_partition_engaged_sn2;
+	xpc_assume_partition_disengaged = xpc_assume_partition_disengaged_sn2;
+
+	xpc_send_payload = xpc_send_payload_sn2;
+	xpc_received_payload = xpc_received_payload_sn2;
+
+	if (offsetof(struct xpc_msg_sn2, payload) > XPC_MSG_HDR_MAX_SIZE) {
+		dev_err(xpc_part, "header portion of struct xpc_msg_sn2 is "
+			"larger than %d\n", XPC_MSG_HDR_MAX_SIZE);
+		return -E2BIG;
+	}
+
+	buf_size = max(XPC_RP_VARS_SIZE,
+		       XPC_RP_HEADER_SIZE + XP_NASID_MASK_BYTES_SN2);
+	xpc_remote_copy_buffer_sn2 = xpc_kmalloc_cacheline_aligned(buf_size,
+								   GFP_KERNEL,
+					      &xpc_remote_copy_buffer_base_sn2);
+	if (xpc_remote_copy_buffer_sn2 == NULL) {
+		dev_err(xpc_part, "can't get memory for remote copy buffer\n");
+		return -ENOMEM;
+	}
+
+	/* open up protections for IPI and [potentially] amo operations */
+	xpc_allow_IPI_ops_sn2();
+	xpc_allow_amo_ops_shub_wars_1_1_sn2();
+
+	/*
+	 * This is safe to do before the xpc_hb_checker thread has started
+	 * because the handler releases a wait queue.  If an interrupt is
+	 * received before the thread is waiting, it will not go to sleep,
+	 * but rather immediately process the interrupt.
+	 */
+	ret = request_irq(SGI_XPC_ACTIVATE, xpc_handle_activate_IRQ_sn2, 0,
+			  "xpc hb", NULL);
+	if (ret != 0) {
+		dev_err(xpc_part, "can't register ACTIVATE IRQ handler, "
+			"errno=%d\n", -ret);
+		xpc_disallow_IPI_ops_sn2();
+		kfree(xpc_remote_copy_buffer_base_sn2);
+	}
+	return ret;
+}
+
+void
+xpc_exit_sn2(void)
+{
+	free_irq(SGI_XPC_ACTIVATE, NULL);
+	xpc_disallow_IPI_ops_sn2();
+	kfree(xpc_remote_copy_buffer_base_sn2);
+}
diff --git a/drivers/misc/sgi-xp/xpc_uv.c b/drivers/misc/sgi-xp/xpc_uv.c
new file mode 100644
index 00000000000..1ac694c0162
--- /dev/null
+++ b/drivers/misc/sgi-xp/xpc_uv.c
@@ -0,0 +1,1443 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (c) 2008 Silicon Graphics, Inc.  All Rights Reserved.
+ */
+
+/*
+ * Cross Partition Communication (XPC) uv-based functions.
+ *
+ *     Architecture specific implementation of common functions.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <asm/uv/uv_hub.h>
+#include "../sgi-gru/gru.h"
+#include "../sgi-gru/grukservices.h"
+#include "xpc.h"
+
+static atomic64_t xpc_heartbeat_uv;
+static DECLARE_BITMAP(xpc_heartbeating_to_mask_uv, XP_MAX_NPARTITIONS_UV);
+
+#define XPC_ACTIVATE_MSG_SIZE_UV	(1 * GRU_CACHE_LINE_BYTES)
+#define XPC_NOTIFY_MSG_SIZE_UV		(2 * GRU_CACHE_LINE_BYTES)
+
+#define XPC_ACTIVATE_MQ_SIZE_UV	(4 * XP_MAX_NPARTITIONS_UV * \
+				 XPC_ACTIVATE_MSG_SIZE_UV)
+#define XPC_NOTIFY_MQ_SIZE_UV	(4 * XP_MAX_NPARTITIONS_UV * \
+				 XPC_NOTIFY_MSG_SIZE_UV)
+
+static void *xpc_activate_mq_uv;
+static void *xpc_notify_mq_uv;
+
+static int
+xpc_setup_partitions_sn_uv(void)
+{
+	short partid;
+	struct xpc_partition_uv *part_uv;
+
+	for (partid = 0; partid < XP_MAX_NPARTITIONS_UV; partid++) {
+		part_uv = &xpc_partitions[partid].sn.uv;
+
+		spin_lock_init(&part_uv->flags_lock);
+		part_uv->remote_act_state = XPC_P_AS_INACTIVE;
+	}
+	return 0;
+}
+
+static void *
+xpc_create_gru_mq_uv(unsigned int mq_size, int cpuid, unsigned int irq,
+		     irq_handler_t irq_handler)
+{
+	int ret;
+	int nid;
+	int mq_order;
+	struct page *page;
+	void *mq;
+
+	nid = cpu_to_node(cpuid);
+	mq_order = get_order(mq_size);
+	page = alloc_pages_node(nid, GFP_KERNEL | __GFP_ZERO | GFP_THISNODE,
+				mq_order);
+	if (page == NULL) {
+		dev_err(xpc_part, "xpc_create_gru_mq_uv() failed to alloc %d "
+			"bytes of memory on nid=%d for GRU mq\n", mq_size, nid);
+		return NULL;
+	}
+
+	mq = page_address(page);
+	ret = gru_create_message_queue(mq, mq_size);
+	if (ret != 0) {
+		dev_err(xpc_part, "gru_create_message_queue() returned "
+			"error=%d\n", ret);
+		free_pages((unsigned long)mq, mq_order);
+		return NULL;
+	}
+
+	/* !!! Need to do some other things to set up IRQ */
+
+	ret = request_irq(irq, irq_handler, 0, "xpc", NULL);
+	if (ret != 0) {
+		dev_err(xpc_part, "request_irq(irq=%d) returned error=%d\n",
+			irq, ret);
+		free_pages((unsigned long)mq, mq_order);
+		return NULL;
+	}
+
+	/* !!! enable generation of irq when GRU mq op occurs to this mq */
+
+	/* ??? allow other partitions to access GRU mq? */
+
+	return mq;
+}
+
+static void
+xpc_destroy_gru_mq_uv(void *mq, unsigned int mq_size, unsigned int irq)
+{
+	/* ??? disallow other partitions to access GRU mq? */
+
+	/* !!! disable generation of irq when GRU mq op occurs to this mq */
+
+	free_irq(irq, NULL);
+
+	free_pages((unsigned long)mq, get_order(mq_size));
+}
+
+static enum xp_retval
+xpc_send_gru_msg(unsigned long mq_gpa, void *msg, size_t msg_size)
+{
+	enum xp_retval xp_ret;
+	int ret;
+
+	while (1) {
+		ret = gru_send_message_gpa(mq_gpa, msg, msg_size);
+		if (ret == MQE_OK) {
+			xp_ret = xpSuccess;
+			break;
+		}
+
+		if (ret == MQE_QUEUE_FULL) {
+			dev_dbg(xpc_chan, "gru_send_message_gpa() returned "
+				"error=MQE_QUEUE_FULL\n");
+			/* !!! handle QLimit reached; delay & try again */
+			/* ??? Do we add a limit to the number of retries? */
+			(void)msleep_interruptible(10);
+		} else if (ret == MQE_CONGESTION) {
+			dev_dbg(xpc_chan, "gru_send_message_gpa() returned "
+				"error=MQE_CONGESTION\n");
+			/* !!! handle LB Overflow; simply try again */
+			/* ??? Do we add a limit to the number of retries? */
+		} else {
+			/* !!! Currently this is MQE_UNEXPECTED_CB_ERR */
+			dev_err(xpc_chan, "gru_send_message_gpa() returned "
+				"error=%d\n", ret);
+			xp_ret = xpGruSendMqError;
+			break;
+		}
+	}
+	return xp_ret;
+}
+
+static void
+xpc_process_activate_IRQ_rcvd_uv(void)
+{
+	unsigned long irq_flags;
+	short partid;
+	struct xpc_partition *part;
+	u8 act_state_req;
+
+	DBUG_ON(xpc_activate_IRQ_rcvd == 0);
+
+	spin_lock_irqsave(&xpc_activate_IRQ_rcvd_lock, irq_flags);
+	for (partid = 0; partid < XP_MAX_NPARTITIONS_UV; partid++) {
+		part = &xpc_partitions[partid];
+
+		if (part->sn.uv.act_state_req == 0)
+			continue;
+
+		xpc_activate_IRQ_rcvd--;
+		BUG_ON(xpc_activate_IRQ_rcvd < 0);
+
+		act_state_req = part->sn.uv.act_state_req;
+		part->sn.uv.act_state_req = 0;
+		spin_unlock_irqrestore(&xpc_activate_IRQ_rcvd_lock, irq_flags);
+
+		if (act_state_req == XPC_P_ASR_ACTIVATE_UV) {
+			if (part->act_state == XPC_P_AS_INACTIVE)
+				xpc_activate_partition(part);
+			else if (part->act_state == XPC_P_AS_DEACTIVATING)
+				XPC_DEACTIVATE_PARTITION(part, xpReactivating);
+
+		} else if (act_state_req == XPC_P_ASR_REACTIVATE_UV) {
+			if (part->act_state == XPC_P_AS_INACTIVE)
+				xpc_activate_partition(part);
+			else
+				XPC_DEACTIVATE_PARTITION(part, xpReactivating);
+
+		} else if (act_state_req == XPC_P_ASR_DEACTIVATE_UV) {
+			XPC_DEACTIVATE_PARTITION(part, part->sn.uv.reason);
+
+		} else {
+			BUG();
+		}
+
+		spin_lock_irqsave(&xpc_activate_IRQ_rcvd_lock, irq_flags);
+		if (xpc_activate_IRQ_rcvd == 0)
+			break;
+	}
+	spin_unlock_irqrestore(&xpc_activate_IRQ_rcvd_lock, irq_flags);
+
+}
+
+static void
+xpc_handle_activate_mq_msg_uv(struct xpc_partition *part,
+			      struct xpc_activate_mq_msghdr_uv *msg_hdr,
+			      int *wakeup_hb_checker)
+{
+	unsigned long irq_flags;
+	struct xpc_partition_uv *part_uv = &part->sn.uv;
+	struct xpc_openclose_args *args;
+
+	part_uv->remote_act_state = msg_hdr->act_state;
+
+	switch (msg_hdr->type) {
+	case XPC_ACTIVATE_MQ_MSG_SYNC_ACT_STATE_UV:
+		/* syncing of remote_act_state was just done above */
+		break;
+
+	case XPC_ACTIVATE_MQ_MSG_INC_HEARTBEAT_UV: {
+		struct xpc_activate_mq_msg_heartbeat_req_uv *msg;
+
+		msg = container_of(msg_hdr,
+				   struct xpc_activate_mq_msg_heartbeat_req_uv,
+				   hdr);
+		part_uv->heartbeat = msg->heartbeat;
+		break;
+	}
+	case XPC_ACTIVATE_MQ_MSG_OFFLINE_HEARTBEAT_UV: {
+		struct xpc_activate_mq_msg_heartbeat_req_uv *msg;
+
+		msg = container_of(msg_hdr,
+				   struct xpc_activate_mq_msg_heartbeat_req_uv,
+				   hdr);
+		part_uv->heartbeat = msg->heartbeat;
+
+		spin_lock_irqsave(&part_uv->flags_lock, irq_flags);
+		part_uv->flags |= XPC_P_HEARTBEAT_OFFLINE_UV;
+		spin_unlock_irqrestore(&part_uv->flags_lock, irq_flags);
+		break;
+	}
+	case XPC_ACTIVATE_MQ_MSG_ONLINE_HEARTBEAT_UV: {
+		struct xpc_activate_mq_msg_heartbeat_req_uv *msg;
+
+		msg = container_of(msg_hdr,
+				   struct xpc_activate_mq_msg_heartbeat_req_uv,
+				   hdr);
+		part_uv->heartbeat = msg->heartbeat;
+
+		spin_lock_irqsave(&part_uv->flags_lock, irq_flags);
+		part_uv->flags &= ~XPC_P_HEARTBEAT_OFFLINE_UV;
+		spin_unlock_irqrestore(&part_uv->flags_lock, irq_flags);
+		break;
+	}
+	case XPC_ACTIVATE_MQ_MSG_ACTIVATE_REQ_UV: {
+		struct xpc_activate_mq_msg_activate_req_uv *msg;
+
+		/*
+		 * ??? Do we deal here with ts_jiffies being different
+		 * ??? if act_state != XPC_P_AS_INACTIVE instead of
+		 * ??? below?
+		 */
+		msg = container_of(msg_hdr, struct
+				   xpc_activate_mq_msg_activate_req_uv, hdr);
+
+		spin_lock_irqsave(&xpc_activate_IRQ_rcvd_lock, irq_flags);
+		if (part_uv->act_state_req == 0)
+			xpc_activate_IRQ_rcvd++;
+		part_uv->act_state_req = XPC_P_ASR_ACTIVATE_UV;
+		part->remote_rp_pa = msg->rp_gpa; /* !!! _pa is _gpa */
+		part->remote_rp_ts_jiffies = msg_hdr->rp_ts_jiffies;
+		part_uv->remote_activate_mq_gpa = msg->activate_mq_gpa;
+		spin_unlock_irqrestore(&xpc_activate_IRQ_rcvd_lock, irq_flags);
+
+		(*wakeup_hb_checker)++;
+		break;
+	}
+	case XPC_ACTIVATE_MQ_MSG_DEACTIVATE_REQ_UV: {
+		struct xpc_activate_mq_msg_deactivate_req_uv *msg;
+
+		msg = container_of(msg_hdr, struct
+				   xpc_activate_mq_msg_deactivate_req_uv, hdr);
+
+		spin_lock_irqsave(&xpc_activate_IRQ_rcvd_lock, irq_flags);
+		if (part_uv->act_state_req == 0)
+			xpc_activate_IRQ_rcvd++;
+		part_uv->act_state_req = XPC_P_ASR_DEACTIVATE_UV;
+		part_uv->reason = msg->reason;
+		spin_unlock_irqrestore(&xpc_activate_IRQ_rcvd_lock, irq_flags);
+
+		(*wakeup_hb_checker)++;
+		return;
+	}
+	case XPC_ACTIVATE_MQ_MSG_CHCTL_CLOSEREQUEST_UV: {
+		struct xpc_activate_mq_msg_chctl_closerequest_uv *msg;
+
+		msg = container_of(msg_hdr, struct
+				   xpc_activate_mq_msg_chctl_closerequest_uv,
+				   hdr);
+		args = &part->remote_openclose_args[msg->ch_number];
+		args->reason = msg->reason;
+
+		spin_lock_irqsave(&part->chctl_lock, irq_flags);
+		part->chctl.flags[msg->ch_number] |= XPC_CHCTL_CLOSEREQUEST;
+		spin_unlock_irqrestore(&part->chctl_lock, irq_flags);
+
+		xpc_wakeup_channel_mgr(part);
+		break;
+	}
+	case XPC_ACTIVATE_MQ_MSG_CHCTL_CLOSEREPLY_UV: {
+		struct xpc_activate_mq_msg_chctl_closereply_uv *msg;
+
+		msg = container_of(msg_hdr, struct
+				   xpc_activate_mq_msg_chctl_closereply_uv,
+				   hdr);
+
+		spin_lock_irqsave(&part->chctl_lock, irq_flags);
+		part->chctl.flags[msg->ch_number] |= XPC_CHCTL_CLOSEREPLY;
+		spin_unlock_irqrestore(&part->chctl_lock, irq_flags);
+
+		xpc_wakeup_channel_mgr(part);
+		break;
+	}
+	case XPC_ACTIVATE_MQ_MSG_CHCTL_OPENREQUEST_UV: {
+		struct xpc_activate_mq_msg_chctl_openrequest_uv *msg;
+
+		msg = container_of(msg_hdr, struct
+				   xpc_activate_mq_msg_chctl_openrequest_uv,
+				   hdr);
+		args = &part->remote_openclose_args[msg->ch_number];
+		args->entry_size = msg->entry_size;
+		args->local_nentries = msg->local_nentries;
+
+		spin_lock_irqsave(&part->chctl_lock, irq_flags);
+		part->chctl.flags[msg->ch_number] |= XPC_CHCTL_OPENREQUEST;
+		spin_unlock_irqrestore(&part->chctl_lock, irq_flags);
+
+		xpc_wakeup_channel_mgr(part);
+		break;
+	}
+	case XPC_ACTIVATE_MQ_MSG_CHCTL_OPENREPLY_UV: {
+		struct xpc_activate_mq_msg_chctl_openreply_uv *msg;
+
+		msg = container_of(msg_hdr, struct
+				   xpc_activate_mq_msg_chctl_openreply_uv, hdr);
+		args = &part->remote_openclose_args[msg->ch_number];
+		args->remote_nentries = msg->remote_nentries;
+		args->local_nentries = msg->local_nentries;
+		args->local_msgqueue_pa = msg->local_notify_mq_gpa;
+
+		spin_lock_irqsave(&part->chctl_lock, irq_flags);
+		part->chctl.flags[msg->ch_number] |= XPC_CHCTL_OPENREPLY;
+		spin_unlock_irqrestore(&part->chctl_lock, irq_flags);
+
+		xpc_wakeup_channel_mgr(part);
+		break;
+	}
+	case XPC_ACTIVATE_MQ_MSG_MARK_ENGAGED_UV:
+		spin_lock_irqsave(&part_uv->flags_lock, irq_flags);
+		part_uv->flags |= XPC_P_ENGAGED_UV;
+		spin_unlock_irqrestore(&part_uv->flags_lock, irq_flags);
+		break;
+
+	case XPC_ACTIVATE_MQ_MSG_MARK_DISENGAGED_UV:
+		spin_lock_irqsave(&part_uv->flags_lock, irq_flags);
+		part_uv->flags &= ~XPC_P_ENGAGED_UV;
+		spin_unlock_irqrestore(&part_uv->flags_lock, irq_flags);
+		break;
+
+	default:
+		dev_err(xpc_part, "received unknown activate_mq msg type=%d "
+			"from partition=%d\n", msg_hdr->type, XPC_PARTID(part));
+
+		/* get hb checker to deactivate from the remote partition */
+		spin_lock_irqsave(&xpc_activate_IRQ_rcvd_lock, irq_flags);
+		if (part_uv->act_state_req == 0)
+			xpc_activate_IRQ_rcvd++;
+		part_uv->act_state_req = XPC_P_ASR_DEACTIVATE_UV;
+		part_uv->reason = xpBadMsgType;
+		spin_unlock_irqrestore(&xpc_activate_IRQ_rcvd_lock, irq_flags);
+
+		(*wakeup_hb_checker)++;
+		return;
+	}
+
+	if (msg_hdr->rp_ts_jiffies != part->remote_rp_ts_jiffies &&
+	    part->remote_rp_ts_jiffies != 0) {
+		/*
+		 * ??? Does what we do here need to be sensitive to
+		 * ??? act_state or remote_act_state?
+		 */
+		spin_lock_irqsave(&xpc_activate_IRQ_rcvd_lock, irq_flags);
+		if (part_uv->act_state_req == 0)
+			xpc_activate_IRQ_rcvd++;
+		part_uv->act_state_req = XPC_P_ASR_REACTIVATE_UV;
+		spin_unlock_irqrestore(&xpc_activate_IRQ_rcvd_lock, irq_flags);
+
+		(*wakeup_hb_checker)++;
+	}
+}
+
+static irqreturn_t
+xpc_handle_activate_IRQ_uv(int irq, void *dev_id)
+{
+	struct xpc_activate_mq_msghdr_uv *msg_hdr;
+	short partid;
+	struct xpc_partition *part;
+	int wakeup_hb_checker = 0;
+
+	while ((msg_hdr = gru_get_next_message(xpc_activate_mq_uv)) != NULL) {
+
+		partid = msg_hdr->partid;
+		if (partid < 0 || partid >= XP_MAX_NPARTITIONS_UV) {
+			dev_err(xpc_part, "xpc_handle_activate_IRQ_uv() "
+				"received invalid partid=0x%x in message\n",
+				partid);
+		} else {
+			part = &xpc_partitions[partid];
+			if (xpc_part_ref(part)) {
+				xpc_handle_activate_mq_msg_uv(part, msg_hdr,
+							    &wakeup_hb_checker);
+				xpc_part_deref(part);
+			}
+		}
+
+		gru_free_message(xpc_activate_mq_uv, msg_hdr);
+	}
+
+	if (wakeup_hb_checker)
+		wake_up_interruptible(&xpc_activate_IRQ_wq);
+
+	return IRQ_HANDLED;
+}
+
+static enum xp_retval
+xpc_send_activate_IRQ_uv(struct xpc_partition *part, void *msg, size_t msg_size,
+			 int msg_type)
+{
+	struct xpc_activate_mq_msghdr_uv *msg_hdr = msg;
+
+	DBUG_ON(msg_size > XPC_ACTIVATE_MSG_SIZE_UV);
+
+	msg_hdr->type = msg_type;
+	msg_hdr->partid = XPC_PARTID(part);
+	msg_hdr->act_state = part->act_state;
+	msg_hdr->rp_ts_jiffies = xpc_rsvd_page->ts_jiffies;
+
+	/* ??? Is holding a spin_lock (ch->lock) during this call a bad idea? */
+	return xpc_send_gru_msg(part->sn.uv.remote_activate_mq_gpa, msg,
+				msg_size);
+}
+
+static void
+xpc_send_activate_IRQ_part_uv(struct xpc_partition *part, void *msg,
+			      size_t msg_size, int msg_type)
+{
+	enum xp_retval ret;
+
+	ret = xpc_send_activate_IRQ_uv(part, msg, msg_size, msg_type);
+	if (unlikely(ret != xpSuccess))
+		XPC_DEACTIVATE_PARTITION(part, ret);
+}
+
+static void
+xpc_send_activate_IRQ_ch_uv(struct xpc_channel *ch, unsigned long *irq_flags,
+			 void *msg, size_t msg_size, int msg_type)
+{
+	struct xpc_partition *part = &xpc_partitions[ch->number];
+	enum xp_retval ret;
+
+	ret = xpc_send_activate_IRQ_uv(part, msg, msg_size, msg_type);
+	if (unlikely(ret != xpSuccess)) {
+		if (irq_flags != NULL)
+			spin_unlock_irqrestore(&ch->lock, *irq_flags);
+
+		XPC_DEACTIVATE_PARTITION(part, ret);
+
+		if (irq_flags != NULL)
+			spin_lock_irqsave(&ch->lock, *irq_flags);
+	}
+}
+
+static void
+xpc_send_local_activate_IRQ_uv(struct xpc_partition *part, int act_state_req)
+{
+	unsigned long irq_flags;
+	struct xpc_partition_uv *part_uv = &part->sn.uv;
+
+	/*
+	 * !!! Make our side think that the remote parition sent an activate
+	 * !!! message our way by doing what the activate IRQ handler would
+	 * !!! do had one really been sent.
+	 */
+
+	spin_lock_irqsave(&xpc_activate_IRQ_rcvd_lock, irq_flags);
+	if (part_uv->act_state_req == 0)
+		xpc_activate_IRQ_rcvd++;
+	part_uv->act_state_req = act_state_req;
+	spin_unlock_irqrestore(&xpc_activate_IRQ_rcvd_lock, irq_flags);
+
+	wake_up_interruptible(&xpc_activate_IRQ_wq);
+}
+
+static enum xp_retval
+xpc_get_partition_rsvd_page_pa_uv(void *buf, u64 *cookie, unsigned long *rp_pa,
+				  size_t *len)
+{
+	/* !!! call the UV version of sn_partition_reserved_page_pa() */
+	return xpUnsupported;
+}
+
+static int
+xpc_setup_rsvd_page_sn_uv(struct xpc_rsvd_page *rp)
+{
+	rp->sn.activate_mq_gpa = uv_gpa(xpc_activate_mq_uv);
+	return 0;
+}
+
+static void
+xpc_send_heartbeat_uv(int msg_type)
+{
+	short partid;
+	struct xpc_partition *part;
+	struct xpc_activate_mq_msg_heartbeat_req_uv msg;
+
+	/*
+	 * !!! On uv we're broadcasting a heartbeat message every 5 seconds.
+	 * !!! Whereas on sn2 we're bte_copy'ng the heartbeat info every 20
+	 * !!! seconds. This is an increase in numalink traffic.
+	 * ??? Is this good?
+	 */
+
+	msg.heartbeat = atomic64_inc_return(&xpc_heartbeat_uv);
+
+	partid = find_first_bit(xpc_heartbeating_to_mask_uv,
+				XP_MAX_NPARTITIONS_UV);
+
+	while (partid < XP_MAX_NPARTITIONS_UV) {
+		part = &xpc_partitions[partid];
+
+		xpc_send_activate_IRQ_part_uv(part, &msg, sizeof(msg),
+					      msg_type);
+
+		partid = find_next_bit(xpc_heartbeating_to_mask_uv,
+				       XP_MAX_NPARTITIONS_UV, partid + 1);
+	}
+}
+
+static void
+xpc_increment_heartbeat_uv(void)
+{
+	xpc_send_heartbeat_uv(XPC_ACTIVATE_MQ_MSG_INC_HEARTBEAT_UV);
+}
+
+static void
+xpc_offline_heartbeat_uv(void)
+{
+	xpc_send_heartbeat_uv(XPC_ACTIVATE_MQ_MSG_OFFLINE_HEARTBEAT_UV);
+}
+
+static void
+xpc_online_heartbeat_uv(void)
+{
+	xpc_send_heartbeat_uv(XPC_ACTIVATE_MQ_MSG_ONLINE_HEARTBEAT_UV);
+}
+
+static void
+xpc_heartbeat_init_uv(void)
+{
+	atomic64_set(&xpc_heartbeat_uv, 0);
+	bitmap_zero(xpc_heartbeating_to_mask_uv, XP_MAX_NPARTITIONS_UV);
+	xpc_heartbeating_to_mask = &xpc_heartbeating_to_mask_uv[0];
+}
+
+static void
+xpc_heartbeat_exit_uv(void)
+{
+	xpc_send_heartbeat_uv(XPC_ACTIVATE_MQ_MSG_OFFLINE_HEARTBEAT_UV);
+}
+
+static enum xp_retval
+xpc_get_remote_heartbeat_uv(struct xpc_partition *part)
+{
+	struct xpc_partition_uv *part_uv = &part->sn.uv;
+	enum xp_retval ret = xpNoHeartbeat;
+
+	if (part_uv->remote_act_state != XPC_P_AS_INACTIVE &&
+	    part_uv->remote_act_state != XPC_P_AS_DEACTIVATING) {
+
+		if (part_uv->heartbeat != part->last_heartbeat ||
+		    (part_uv->flags & XPC_P_HEARTBEAT_OFFLINE_UV)) {
+
+			part->last_heartbeat = part_uv->heartbeat;
+			ret = xpSuccess;
+		}
+	}
+	return ret;
+}
+
+static void
+xpc_request_partition_activation_uv(struct xpc_rsvd_page *remote_rp,
+				    unsigned long remote_rp_gpa, int nasid)
+{
+	short partid = remote_rp->SAL_partid;
+	struct xpc_partition *part = &xpc_partitions[partid];
+	struct xpc_activate_mq_msg_activate_req_uv msg;
+
+	part->remote_rp_pa = remote_rp_gpa; /* !!! _pa here is really _gpa */
+	part->remote_rp_ts_jiffies = remote_rp->ts_jiffies;
+	part->sn.uv.remote_activate_mq_gpa = remote_rp->sn.activate_mq_gpa;
+
+	/*
+	 * ??? Is it a good idea to make this conditional on what is
+	 * ??? potentially stale state information?
+	 */
+	if (part->sn.uv.remote_act_state == XPC_P_AS_INACTIVE) {
+		msg.rp_gpa = uv_gpa(xpc_rsvd_page);
+		msg.activate_mq_gpa = xpc_rsvd_page->sn.activate_mq_gpa;
+		xpc_send_activate_IRQ_part_uv(part, &msg, sizeof(msg),
+					   XPC_ACTIVATE_MQ_MSG_ACTIVATE_REQ_UV);
+	}
+
+	if (part->act_state == XPC_P_AS_INACTIVE)
+		xpc_send_local_activate_IRQ_uv(part, XPC_P_ASR_ACTIVATE_UV);
+}
+
+static void
+xpc_request_partition_reactivation_uv(struct xpc_partition *part)
+{
+	xpc_send_local_activate_IRQ_uv(part, XPC_P_ASR_ACTIVATE_UV);
+}
+
+static void
+xpc_request_partition_deactivation_uv(struct xpc_partition *part)
+{
+	struct xpc_activate_mq_msg_deactivate_req_uv msg;
+
+	/*
+	 * ??? Is it a good idea to make this conditional on what is
+	 * ??? potentially stale state information?
+	 */
+	if (part->sn.uv.remote_act_state != XPC_P_AS_DEACTIVATING &&
+	    part->sn.uv.remote_act_state != XPC_P_AS_INACTIVE) {
+
+		msg.reason = part->reason;
+		xpc_send_activate_IRQ_part_uv(part, &msg, sizeof(msg),
+					 XPC_ACTIVATE_MQ_MSG_DEACTIVATE_REQ_UV);
+	}
+}
+
+static void
+xpc_cancel_partition_deactivation_request_uv(struct xpc_partition *part)
+{
+	/* nothing needs to be done */
+	return;
+}
+
+static void
+xpc_init_fifo_uv(struct xpc_fifo_head_uv *head)
+{
+	head->first = NULL;
+	head->last = NULL;
+	spin_lock_init(&head->lock);
+	head->n_entries = 0;
+}
+
+static void *
+xpc_get_fifo_entry_uv(struct xpc_fifo_head_uv *head)
+{
+	unsigned long irq_flags;
+	struct xpc_fifo_entry_uv *first;
+
+	spin_lock_irqsave(&head->lock, irq_flags);
+	first = head->first;
+	if (head->first != NULL) {
+		head->first = first->next;
+		if (head->first == NULL)
+			head->last = NULL;
+	}
+	head->n_entries++;
+	spin_unlock_irqrestore(&head->lock, irq_flags);
+	first->next = NULL;
+	return first;
+}
+
+static void
+xpc_put_fifo_entry_uv(struct xpc_fifo_head_uv *head,
+		      struct xpc_fifo_entry_uv *last)
+{
+	unsigned long irq_flags;
+
+	last->next = NULL;
+	spin_lock_irqsave(&head->lock, irq_flags);
+	if (head->last != NULL)
+		head->last->next = last;
+	else
+		head->first = last;
+	head->last = last;
+	head->n_entries--;
+	BUG_ON(head->n_entries < 0);
+	spin_unlock_irqrestore(&head->lock, irq_flags);
+}
+
+static int
+xpc_n_of_fifo_entries_uv(struct xpc_fifo_head_uv *head)
+{
+	return head->n_entries;
+}
+
+/*
+ * Setup the channel structures that are uv specific.
+ */
+static enum xp_retval
+xpc_setup_ch_structures_sn_uv(struct xpc_partition *part)
+{
+	struct xpc_channel_uv *ch_uv;
+	int ch_number;
+
+	for (ch_number = 0; ch_number < part->nchannels; ch_number++) {
+		ch_uv = &part->channels[ch_number].sn.uv;
+
+		xpc_init_fifo_uv(&ch_uv->msg_slot_free_list);
+		xpc_init_fifo_uv(&ch_uv->recv_msg_list);
+	}
+
+	return xpSuccess;
+}
+
+/*
+ * Teardown the channel structures that are uv specific.
+ */
+static void
+xpc_teardown_ch_structures_sn_uv(struct xpc_partition *part)
+{
+	/* nothing needs to be done */
+	return;
+}
+
+static enum xp_retval
+xpc_make_first_contact_uv(struct xpc_partition *part)
+{
+	struct xpc_activate_mq_msg_uv msg;
+
+	/*
+	 * We send a sync msg to get the remote partition's remote_act_state
+	 * updated to our current act_state which at this point should
+	 * be XPC_P_AS_ACTIVATING.
+	 */
+	xpc_send_activate_IRQ_part_uv(part, &msg, sizeof(msg),
+				      XPC_ACTIVATE_MQ_MSG_SYNC_ACT_STATE_UV);
+
+	while (part->sn.uv.remote_act_state != XPC_P_AS_ACTIVATING) {
+
+		dev_dbg(xpc_part, "waiting to make first contact with "
+			"partition %d\n", XPC_PARTID(part));
+
+		/* wait a 1/4 of a second or so */
+		(void)msleep_interruptible(250);
+
+		if (part->act_state == XPC_P_AS_DEACTIVATING)
+			return part->reason;
+	}
+
+	return xpSuccess;
+}
+
+static u64
+xpc_get_chctl_all_flags_uv(struct xpc_partition *part)
+{
+	unsigned long irq_flags;
+	union xpc_channel_ctl_flags chctl;
+
+	spin_lock_irqsave(&part->chctl_lock, irq_flags);
+	chctl = part->chctl;
+	if (chctl.all_flags != 0)
+		part->chctl.all_flags = 0;
+
+	spin_unlock_irqrestore(&part->chctl_lock, irq_flags);
+	return chctl.all_flags;
+}
+
+static enum xp_retval
+xpc_allocate_send_msg_slot_uv(struct xpc_channel *ch)
+{
+	struct xpc_channel_uv *ch_uv = &ch->sn.uv;
+	struct xpc_send_msg_slot_uv *msg_slot;
+	unsigned long irq_flags;
+	int nentries;
+	int entry;
+	size_t nbytes;
+
+	for (nentries = ch->local_nentries; nentries > 0; nentries--) {
+		nbytes = nentries * sizeof(struct xpc_send_msg_slot_uv);
+		ch_uv->send_msg_slots = kzalloc(nbytes, GFP_KERNEL);
+		if (ch_uv->send_msg_slots == NULL)
+			continue;
+
+		for (entry = 0; entry < nentries; entry++) {
+			msg_slot = &ch_uv->send_msg_slots[entry];
+
+			msg_slot->msg_slot_number = entry;
+			xpc_put_fifo_entry_uv(&ch_uv->msg_slot_free_list,
+					      &msg_slot->next);
+		}
+
+		spin_lock_irqsave(&ch->lock, irq_flags);
+		if (nentries < ch->local_nentries)
+			ch->local_nentries = nentries;
+		spin_unlock_irqrestore(&ch->lock, irq_flags);
+		return xpSuccess;
+	}
+
+	return xpNoMemory;
+}
+
+static enum xp_retval
+xpc_allocate_recv_msg_slot_uv(struct xpc_channel *ch)
+{
+	struct xpc_channel_uv *ch_uv = &ch->sn.uv;
+	struct xpc_notify_mq_msg_uv *msg_slot;
+	unsigned long irq_flags;
+	int nentries;
+	int entry;
+	size_t nbytes;
+
+	for (nentries = ch->remote_nentries; nentries > 0; nentries--) {
+		nbytes = nentries * ch->entry_size;
+		ch_uv->recv_msg_slots = kzalloc(nbytes, GFP_KERNEL);
+		if (ch_uv->recv_msg_slots == NULL)
+			continue;
+
+		for (entry = 0; entry < nentries; entry++) {
+			msg_slot = ch_uv->recv_msg_slots + entry *
+			    ch->entry_size;
+
+			msg_slot->hdr.msg_slot_number = entry;
+		}
+
+		spin_lock_irqsave(&ch->lock, irq_flags);
+		if (nentries < ch->remote_nentries)
+			ch->remote_nentries = nentries;
+		spin_unlock_irqrestore(&ch->lock, irq_flags);
+		return xpSuccess;
+	}
+
+	return xpNoMemory;
+}
+
+/*
+ * Allocate msg_slots associated with the channel.
+ */
+static enum xp_retval
+xpc_setup_msg_structures_uv(struct xpc_channel *ch)
+{
+	static enum xp_retval ret;
+	struct xpc_channel_uv *ch_uv = &ch->sn.uv;
+
+	DBUG_ON(ch->flags & XPC_C_SETUP);
+
+	ret = xpc_allocate_send_msg_slot_uv(ch);
+	if (ret == xpSuccess) {
+
+		ret = xpc_allocate_recv_msg_slot_uv(ch);
+		if (ret != xpSuccess) {
+			kfree(ch_uv->send_msg_slots);
+			xpc_init_fifo_uv(&ch_uv->msg_slot_free_list);
+		}
+	}
+	return ret;
+}
+
+/*
+ * Free up msg_slots and clear other stuff that were setup for the specified
+ * channel.
+ */
+static void
+xpc_teardown_msg_structures_uv(struct xpc_channel *ch)
+{
+	struct xpc_channel_uv *ch_uv = &ch->sn.uv;
+
+	DBUG_ON(!spin_is_locked(&ch->lock));
+
+	ch_uv->remote_notify_mq_gpa = 0;
+
+	if (ch->flags & XPC_C_SETUP) {
+		xpc_init_fifo_uv(&ch_uv->msg_slot_free_list);
+		kfree(ch_uv->send_msg_slots);
+		xpc_init_fifo_uv(&ch_uv->recv_msg_list);
+		kfree(ch_uv->recv_msg_slots);
+	}
+}
+
+static void
+xpc_send_chctl_closerequest_uv(struct xpc_channel *ch, unsigned long *irq_flags)
+{
+	struct xpc_activate_mq_msg_chctl_closerequest_uv msg;
+
+	msg.ch_number = ch->number;
+	msg.reason = ch->reason;
+	xpc_send_activate_IRQ_ch_uv(ch, irq_flags, &msg, sizeof(msg),
+				    XPC_ACTIVATE_MQ_MSG_CHCTL_CLOSEREQUEST_UV);
+}
+
+static void
+xpc_send_chctl_closereply_uv(struct xpc_channel *ch, unsigned long *irq_flags)
+{
+	struct xpc_activate_mq_msg_chctl_closereply_uv msg;
+
+	msg.ch_number = ch->number;
+	xpc_send_activate_IRQ_ch_uv(ch, irq_flags, &msg, sizeof(msg),
+				    XPC_ACTIVATE_MQ_MSG_CHCTL_CLOSEREPLY_UV);
+}
+
+static void
+xpc_send_chctl_openrequest_uv(struct xpc_channel *ch, unsigned long *irq_flags)
+{
+	struct xpc_activate_mq_msg_chctl_openrequest_uv msg;
+
+	msg.ch_number = ch->number;
+	msg.entry_size = ch->entry_size;
+	msg.local_nentries = ch->local_nentries;
+	xpc_send_activate_IRQ_ch_uv(ch, irq_flags, &msg, sizeof(msg),
+				    XPC_ACTIVATE_MQ_MSG_CHCTL_OPENREQUEST_UV);
+}
+
+static void
+xpc_send_chctl_openreply_uv(struct xpc_channel *ch, unsigned long *irq_flags)
+{
+	struct xpc_activate_mq_msg_chctl_openreply_uv msg;
+
+	msg.ch_number = ch->number;
+	msg.local_nentries = ch->local_nentries;
+	msg.remote_nentries = ch->remote_nentries;
+	msg.local_notify_mq_gpa = uv_gpa(xpc_notify_mq_uv);
+	xpc_send_activate_IRQ_ch_uv(ch, irq_flags, &msg, sizeof(msg),
+				    XPC_ACTIVATE_MQ_MSG_CHCTL_OPENREPLY_UV);
+}
+
+static void
+xpc_send_chctl_local_msgrequest_uv(struct xpc_partition *part, int ch_number)
+{
+	unsigned long irq_flags;
+
+	spin_lock_irqsave(&part->chctl_lock, irq_flags);
+	part->chctl.flags[ch_number] |= XPC_CHCTL_MSGREQUEST;
+	spin_unlock_irqrestore(&part->chctl_lock, irq_flags);
+
+	xpc_wakeup_channel_mgr(part);
+}
+
+static void
+xpc_save_remote_msgqueue_pa_uv(struct xpc_channel *ch,
+			       unsigned long msgqueue_pa)
+{
+	ch->sn.uv.remote_notify_mq_gpa = msgqueue_pa;
+}
+
+static void
+xpc_indicate_partition_engaged_uv(struct xpc_partition *part)
+{
+	struct xpc_activate_mq_msg_uv msg;
+
+	xpc_send_activate_IRQ_part_uv(part, &msg, sizeof(msg),
+				      XPC_ACTIVATE_MQ_MSG_MARK_ENGAGED_UV);
+}
+
+static void
+xpc_indicate_partition_disengaged_uv(struct xpc_partition *part)
+{
+	struct xpc_activate_mq_msg_uv msg;
+
+	xpc_send_activate_IRQ_part_uv(part, &msg, sizeof(msg),
+				      XPC_ACTIVATE_MQ_MSG_MARK_DISENGAGED_UV);
+}
+
+static void
+xpc_assume_partition_disengaged_uv(short partid)
+{
+	struct xpc_partition_uv *part_uv = &xpc_partitions[partid].sn.uv;
+	unsigned long irq_flags;
+
+	spin_lock_irqsave(&part_uv->flags_lock, irq_flags);
+	part_uv->flags &= ~XPC_P_ENGAGED_UV;
+	spin_unlock_irqrestore(&part_uv->flags_lock, irq_flags);
+}
+
+static int
+xpc_partition_engaged_uv(short partid)
+{
+	return (xpc_partitions[partid].sn.uv.flags & XPC_P_ENGAGED_UV) != 0;
+}
+
+static int
+xpc_any_partition_engaged_uv(void)
+{
+	struct xpc_partition_uv *part_uv;
+	short partid;
+
+	for (partid = 0; partid < XP_MAX_NPARTITIONS_UV; partid++) {
+		part_uv = &xpc_partitions[partid].sn.uv;
+		if ((part_uv->flags & XPC_P_ENGAGED_UV) != 0)
+			return 1;
+	}
+	return 0;
+}
+
+static enum xp_retval
+xpc_allocate_msg_slot_uv(struct xpc_channel *ch, u32 flags,
+			 struct xpc_send_msg_slot_uv **address_of_msg_slot)
+{
+	enum xp_retval ret;
+	struct xpc_send_msg_slot_uv *msg_slot;
+	struct xpc_fifo_entry_uv *entry;
+
+	while (1) {
+		entry = xpc_get_fifo_entry_uv(&ch->sn.uv.msg_slot_free_list);
+		if (entry != NULL)
+			break;
+
+		if (flags & XPC_NOWAIT)
+			return xpNoWait;
+
+		ret = xpc_allocate_msg_wait(ch);
+		if (ret != xpInterrupted && ret != xpTimeout)
+			return ret;
+	}
+
+	msg_slot = container_of(entry, struct xpc_send_msg_slot_uv, next);
+	*address_of_msg_slot = msg_slot;
+	return xpSuccess;
+}
+
+static void
+xpc_free_msg_slot_uv(struct xpc_channel *ch,
+		     struct xpc_send_msg_slot_uv *msg_slot)
+{
+	xpc_put_fifo_entry_uv(&ch->sn.uv.msg_slot_free_list, &msg_slot->next);
+
+	/* wakeup anyone waiting for a free msg slot */
+	if (atomic_read(&ch->n_on_msg_allocate_wq) > 0)
+		wake_up(&ch->msg_allocate_wq);
+}
+
+static void
+xpc_notify_sender_uv(struct xpc_channel *ch,
+		     struct xpc_send_msg_slot_uv *msg_slot,
+		     enum xp_retval reason)
+{
+	xpc_notify_func func = msg_slot->func;
+
+	if (func != NULL && cmpxchg(&msg_slot->func, func, NULL) == func) {
+
+		atomic_dec(&ch->n_to_notify);
+
+		dev_dbg(xpc_chan, "msg_slot->func() called, msg_slot=0x%p "
+			"msg_slot_number=%d partid=%d channel=%d\n", msg_slot,
+			msg_slot->msg_slot_number, ch->partid, ch->number);
+
+		func(reason, ch->partid, ch->number, msg_slot->key);
+
+		dev_dbg(xpc_chan, "msg_slot->func() returned, msg_slot=0x%p "
+			"msg_slot_number=%d partid=%d channel=%d\n", msg_slot,
+			msg_slot->msg_slot_number, ch->partid, ch->number);
+	}
+}
+
+static void
+xpc_handle_notify_mq_ack_uv(struct xpc_channel *ch,
+			    struct xpc_notify_mq_msg_uv *msg)
+{
+	struct xpc_send_msg_slot_uv *msg_slot;
+	int entry = msg->hdr.msg_slot_number % ch->local_nentries;
+
+	msg_slot = &ch->sn.uv.send_msg_slots[entry];
+
+	BUG_ON(msg_slot->msg_slot_number != msg->hdr.msg_slot_number);
+	msg_slot->msg_slot_number += ch->local_nentries;
+
+	if (msg_slot->func != NULL)
+		xpc_notify_sender_uv(ch, msg_slot, xpMsgDelivered);
+
+	xpc_free_msg_slot_uv(ch, msg_slot);
+}
+
+static void
+xpc_handle_notify_mq_msg_uv(struct xpc_partition *part,
+			    struct xpc_notify_mq_msg_uv *msg)
+{
+	struct xpc_partition_uv *part_uv = &part->sn.uv;
+	struct xpc_channel *ch;
+	struct xpc_channel_uv *ch_uv;
+	struct xpc_notify_mq_msg_uv *msg_slot;
+	unsigned long irq_flags;
+	int ch_number = msg->hdr.ch_number;
+
+	if (unlikely(ch_number >= part->nchannels)) {
+		dev_err(xpc_part, "xpc_handle_notify_IRQ_uv() received invalid "
+			"channel number=0x%x in message from partid=%d\n",
+			ch_number, XPC_PARTID(part));
+
+		/* get hb checker to deactivate from the remote partition */
+		spin_lock_irqsave(&xpc_activate_IRQ_rcvd_lock, irq_flags);
+		if (part_uv->act_state_req == 0)
+			xpc_activate_IRQ_rcvd++;
+		part_uv->act_state_req = XPC_P_ASR_DEACTIVATE_UV;
+		part_uv->reason = xpBadChannelNumber;
+		spin_unlock_irqrestore(&xpc_activate_IRQ_rcvd_lock, irq_flags);
+
+		wake_up_interruptible(&xpc_activate_IRQ_wq);
+		return;
+	}
+
+	ch = &part->channels[ch_number];
+	xpc_msgqueue_ref(ch);
+
+	if (!(ch->flags & XPC_C_CONNECTED)) {
+		xpc_msgqueue_deref(ch);
+		return;
+	}
+
+	/* see if we're really dealing with an ACK for a previously sent msg */
+	if (msg->hdr.size == 0) {
+		xpc_handle_notify_mq_ack_uv(ch, msg);
+		xpc_msgqueue_deref(ch);
+		return;
+	}
+
+	/* we're dealing with a normal message sent via the notify_mq */
+	ch_uv = &ch->sn.uv;
+
+	msg_slot = (struct xpc_notify_mq_msg_uv *)((u64)ch_uv->recv_msg_slots +
+		    (msg->hdr.msg_slot_number % ch->remote_nentries) *
+		    ch->entry_size);
+
+	BUG_ON(msg->hdr.msg_slot_number != msg_slot->hdr.msg_slot_number);
+	BUG_ON(msg_slot->hdr.size != 0);
+
+	memcpy(msg_slot, msg, msg->hdr.size);
+
+	xpc_put_fifo_entry_uv(&ch_uv->recv_msg_list, &msg_slot->hdr.u.next);
+
+	if (ch->flags & XPC_C_CONNECTEDCALLOUT_MADE) {
+		/*
+		 * If there is an existing idle kthread get it to deliver
+		 * the payload, otherwise we'll have to get the channel mgr
+		 * for this partition to create a kthread to do the delivery.
+		 */
+		if (atomic_read(&ch->kthreads_idle) > 0)
+			wake_up_nr(&ch->idle_wq, 1);
+		else
+			xpc_send_chctl_local_msgrequest_uv(part, ch->number);
+	}
+	xpc_msgqueue_deref(ch);
+}
+
+static irqreturn_t
+xpc_handle_notify_IRQ_uv(int irq, void *dev_id)
+{
+	struct xpc_notify_mq_msg_uv *msg;
+	short partid;
+	struct xpc_partition *part;
+
+	while ((msg = gru_get_next_message(xpc_notify_mq_uv)) != NULL) {
+
+		partid = msg->hdr.partid;
+		if (partid < 0 || partid >= XP_MAX_NPARTITIONS_UV) {
+			dev_err(xpc_part, "xpc_handle_notify_IRQ_uv() received "
+				"invalid partid=0x%x in message\n", partid);
+		} else {
+			part = &xpc_partitions[partid];
+
+			if (xpc_part_ref(part)) {
+				xpc_handle_notify_mq_msg_uv(part, msg);
+				xpc_part_deref(part);
+			}
+		}
+
+		gru_free_message(xpc_notify_mq_uv, msg);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int
+xpc_n_of_deliverable_payloads_uv(struct xpc_channel *ch)
+{
+	return xpc_n_of_fifo_entries_uv(&ch->sn.uv.recv_msg_list);
+}
+
+static void
+xpc_process_msg_chctl_flags_uv(struct xpc_partition *part, int ch_number)
+{
+	struct xpc_channel *ch = &part->channels[ch_number];
+	int ndeliverable_payloads;
+
+	xpc_msgqueue_ref(ch);
+
+	ndeliverable_payloads = xpc_n_of_deliverable_payloads_uv(ch);
+
+	if (ndeliverable_payloads > 0 &&
+	    (ch->flags & XPC_C_CONNECTED) &&
+	    (ch->flags & XPC_C_CONNECTEDCALLOUT_MADE)) {
+
+		xpc_activate_kthreads(ch, ndeliverable_payloads);
+	}
+
+	xpc_msgqueue_deref(ch);
+}
+
+static enum xp_retval
+xpc_send_payload_uv(struct xpc_channel *ch, u32 flags, void *payload,
+		    u16 payload_size, u8 notify_type, xpc_notify_func func,
+		    void *key)
+{
+	enum xp_retval ret = xpSuccess;
+	struct xpc_send_msg_slot_uv *msg_slot = NULL;
+	struct xpc_notify_mq_msg_uv *msg;
+	u8 msg_buffer[XPC_NOTIFY_MSG_SIZE_UV];
+	size_t msg_size;
+
+	DBUG_ON(notify_type != XPC_N_CALL);
+
+	msg_size = sizeof(struct xpc_notify_mq_msghdr_uv) + payload_size;
+	if (msg_size > ch->entry_size)
+		return xpPayloadTooBig;
+
+	xpc_msgqueue_ref(ch);
+
+	if (ch->flags & XPC_C_DISCONNECTING) {
+		ret = ch->reason;
+		goto out_1;
+	}
+	if (!(ch->flags & XPC_C_CONNECTED)) {
+		ret = xpNotConnected;
+		goto out_1;
+	}
+
+	ret = xpc_allocate_msg_slot_uv(ch, flags, &msg_slot);
+	if (ret != xpSuccess)
+		goto out_1;
+
+	if (func != NULL) {
+		atomic_inc(&ch->n_to_notify);
+
+		msg_slot->key = key;
+		wmb(); /* a non-NULL func must hit memory after the key */
+		msg_slot->func = func;
+
+		if (ch->flags & XPC_C_DISCONNECTING) {
+			ret = ch->reason;
+			goto out_2;
+		}
+	}
+
+	msg = (struct xpc_notify_mq_msg_uv *)&msg_buffer;
+	msg->hdr.partid = xp_partition_id;
+	msg->hdr.ch_number = ch->number;
+	msg->hdr.size = msg_size;
+	msg->hdr.msg_slot_number = msg_slot->msg_slot_number;
+	memcpy(&msg->payload, payload, payload_size);
+
+	ret = xpc_send_gru_msg(ch->sn.uv.remote_notify_mq_gpa, msg, msg_size);
+	if (ret == xpSuccess)
+		goto out_1;
+
+	XPC_DEACTIVATE_PARTITION(&xpc_partitions[ch->partid], ret);
+out_2:
+	if (func != NULL) {
+		/*
+		 * Try to NULL the msg_slot's func field. If we fail, then
+		 * xpc_notify_senders_of_disconnect_uv() beat us to it, in which
+		 * case we need to pretend we succeeded to send the message
+		 * since the user will get a callout for the disconnect error
+		 * by xpc_notify_senders_of_disconnect_uv(), and to also get an
+		 * error returned here will confuse them. Additionally, since
+		 * in this case the channel is being disconnected we don't need
+		 * to put the the msg_slot back on the free list.
+		 */
+		if (cmpxchg(&msg_slot->func, func, NULL) != func) {
+			ret = xpSuccess;
+			goto out_1;
+		}
+
+		msg_slot->key = NULL;
+		atomic_dec(&ch->n_to_notify);
+	}
+	xpc_free_msg_slot_uv(ch, msg_slot);
+out_1:
+	xpc_msgqueue_deref(ch);
+	return ret;
+}
+
+/*
+ * Tell the callers of xpc_send_notify() that the status of their payloads
+ * is unknown because the channel is now disconnecting.
+ *
+ * We don't worry about putting these msg_slots on the free list since the
+ * msg_slots themselves are about to be kfree'd.
+ */
+static void
+xpc_notify_senders_of_disconnect_uv(struct xpc_channel *ch)
+{
+	struct xpc_send_msg_slot_uv *msg_slot;
+	int entry;
+
+	DBUG_ON(!(ch->flags & XPC_C_DISCONNECTING));
+
+	for (entry = 0; entry < ch->local_nentries; entry++) {
+
+		if (atomic_read(&ch->n_to_notify) == 0)
+			break;
+
+		msg_slot = &ch->sn.uv.send_msg_slots[entry];
+		if (msg_slot->func != NULL)
+			xpc_notify_sender_uv(ch, msg_slot, ch->reason);
+	}
+}
+
+/*
+ * Get the next deliverable message's payload.
+ */
+static void *
+xpc_get_deliverable_payload_uv(struct xpc_channel *ch)
+{
+	struct xpc_fifo_entry_uv *entry;
+	struct xpc_notify_mq_msg_uv *msg;
+	void *payload = NULL;
+
+	if (!(ch->flags & XPC_C_DISCONNECTING)) {
+		entry = xpc_get_fifo_entry_uv(&ch->sn.uv.recv_msg_list);
+		if (entry != NULL) {
+			msg = container_of(entry, struct xpc_notify_mq_msg_uv,
+					   hdr.u.next);
+			payload = &msg->payload;
+		}
+	}
+	return payload;
+}
+
+static void
+xpc_received_payload_uv(struct xpc_channel *ch, void *payload)
+{
+	struct xpc_notify_mq_msg_uv *msg;
+	enum xp_retval ret;
+
+	msg = container_of(payload, struct xpc_notify_mq_msg_uv, payload);
+
+	/* return an ACK to the sender of this message */
+
+	msg->hdr.partid = xp_partition_id;
+	msg->hdr.size = 0;	/* size of zero indicates this is an ACK */
+
+	ret = xpc_send_gru_msg(ch->sn.uv.remote_notify_mq_gpa, msg,
+			       sizeof(struct xpc_notify_mq_msghdr_uv));
+	if (ret != xpSuccess)
+		XPC_DEACTIVATE_PARTITION(&xpc_partitions[ch->partid], ret);
+
+	msg->hdr.msg_slot_number += ch->remote_nentries;
+}
+
+int
+xpc_init_uv(void)
+{
+	xpc_setup_partitions_sn = xpc_setup_partitions_sn_uv;
+	xpc_process_activate_IRQ_rcvd = xpc_process_activate_IRQ_rcvd_uv;
+	xpc_get_partition_rsvd_page_pa = xpc_get_partition_rsvd_page_pa_uv;
+	xpc_setup_rsvd_page_sn = xpc_setup_rsvd_page_sn_uv;
+	xpc_increment_heartbeat = xpc_increment_heartbeat_uv;
+	xpc_offline_heartbeat = xpc_offline_heartbeat_uv;
+	xpc_online_heartbeat = xpc_online_heartbeat_uv;
+	xpc_heartbeat_init = xpc_heartbeat_init_uv;
+	xpc_heartbeat_exit = xpc_heartbeat_exit_uv;
+	xpc_get_remote_heartbeat = xpc_get_remote_heartbeat_uv;
+
+	xpc_request_partition_activation = xpc_request_partition_activation_uv;
+	xpc_request_partition_reactivation =
+	    xpc_request_partition_reactivation_uv;
+	xpc_request_partition_deactivation =
+	    xpc_request_partition_deactivation_uv;
+	xpc_cancel_partition_deactivation_request =
+	    xpc_cancel_partition_deactivation_request_uv;
+
+	xpc_setup_ch_structures_sn = xpc_setup_ch_structures_sn_uv;
+	xpc_teardown_ch_structures_sn = xpc_teardown_ch_structures_sn_uv;
+
+	xpc_make_first_contact = xpc_make_first_contact_uv;
+
+	xpc_get_chctl_all_flags = xpc_get_chctl_all_flags_uv;
+	xpc_send_chctl_closerequest = xpc_send_chctl_closerequest_uv;
+	xpc_send_chctl_closereply = xpc_send_chctl_closereply_uv;
+	xpc_send_chctl_openrequest = xpc_send_chctl_openrequest_uv;
+	xpc_send_chctl_openreply = xpc_send_chctl_openreply_uv;
+
+	xpc_save_remote_msgqueue_pa = xpc_save_remote_msgqueue_pa_uv;
+
+	xpc_setup_msg_structures = xpc_setup_msg_structures_uv;
+	xpc_teardown_msg_structures = xpc_teardown_msg_structures_uv;
+
+	xpc_indicate_partition_engaged = xpc_indicate_partition_engaged_uv;
+	xpc_indicate_partition_disengaged =
+	    xpc_indicate_partition_disengaged_uv;
+	xpc_assume_partition_disengaged = xpc_assume_partition_disengaged_uv;
+	xpc_partition_engaged = xpc_partition_engaged_uv;
+	xpc_any_partition_engaged = xpc_any_partition_engaged_uv;
+
+	xpc_n_of_deliverable_payloads = xpc_n_of_deliverable_payloads_uv;
+	xpc_process_msg_chctl_flags = xpc_process_msg_chctl_flags_uv;
+	xpc_send_payload = xpc_send_payload_uv;
+	xpc_notify_senders_of_disconnect = xpc_notify_senders_of_disconnect_uv;
+	xpc_get_deliverable_payload = xpc_get_deliverable_payload_uv;
+	xpc_received_payload = xpc_received_payload_uv;
+
+	if (sizeof(struct xpc_notify_mq_msghdr_uv) > XPC_MSG_HDR_MAX_SIZE) {
+		dev_err(xpc_part, "xpc_notify_mq_msghdr_uv is larger than %d\n",
+			XPC_MSG_HDR_MAX_SIZE);
+		return -E2BIG;
+	}
+
+	/* ??? The cpuid argument's value is 0, is that what we want? */
+	/* !!! The irq argument's value isn't correct. */
+	xpc_activate_mq_uv = xpc_create_gru_mq_uv(XPC_ACTIVATE_MQ_SIZE_UV, 0, 0,
+						  xpc_handle_activate_IRQ_uv);
+	if (xpc_activate_mq_uv == NULL)
+		return -ENOMEM;
+
+	/* ??? The cpuid argument's value is 0, is that what we want? */
+	/* !!! The irq argument's value isn't correct. */
+	xpc_notify_mq_uv = xpc_create_gru_mq_uv(XPC_NOTIFY_MQ_SIZE_UV, 0, 0,
+						xpc_handle_notify_IRQ_uv);
+	if (xpc_notify_mq_uv == NULL) {
+		/* !!! The irq argument's value isn't correct. */
+		xpc_destroy_gru_mq_uv(xpc_activate_mq_uv,
+				      XPC_ACTIVATE_MQ_SIZE_UV, 0);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+void
+xpc_exit_uv(void)
+{
+	/* !!! The irq argument's value isn't correct. */
+	xpc_destroy_gru_mq_uv(xpc_notify_mq_uv, XPC_NOTIFY_MQ_SIZE_UV, 0);
+
+	/* !!! The irq argument's value isn't correct. */
+	xpc_destroy_gru_mq_uv(xpc_activate_mq_uv, XPC_ACTIVATE_MQ_SIZE_UV, 0);
+}
diff --git a/drivers/misc/sgi-xp/xpnet.c b/drivers/misc/sgi-xp/xpnet.c
index 822dc8e8d7f..71513b3af70 100644
--- a/drivers/misc/sgi-xp/xpnet.c
+++ b/drivers/misc/sgi-xp/xpnet.c
@@ -21,21 +21,8 @@
  */
 
 #include <linux/module.h>
-#include <linux/types.h>
-#include <linux/kernel.h>
-#include <linux/init.h>
-#include <linux/ioport.h>
 #include <linux/netdevice.h>
 #include <linux/etherdevice.h>
-#include <linux/delay.h>
-#include <linux/ethtool.h>
-#include <linux/mii.h>
-#include <linux/smp.h>
-#include <linux/string.h>
-#include <asm/sn/bte.h>
-#include <asm/sn/io.h>
-#include <asm/sn/sn_sal.h>
-#include <asm/atomic.h>
 #include "xp.h"
 
 /*
@@ -57,7 +44,7 @@ struct xpnet_message {
 	u16 version;		/* Version for this message */
 	u16 embedded_bytes;	/* #of bytes embedded in XPC message */
 	u32 magic;		/* Special number indicating this is xpnet */
-	u64 buf_pa;		/* phys address of buffer to retrieve */
+	unsigned long buf_pa;	/* phys address of buffer to retrieve */
 	u32 size;		/* #of bytes in buffer */
 	u8 leadin_ignore;	/* #of bytes to ignore at the beginning */
 	u8 tailout_ignore;	/* #of bytes to ignore at the end */
@@ -70,11 +57,10 @@ struct xpnet_message {
  *
  * XPC expects each message to exist in an individual cacheline.
  */
-#define XPNET_MSG_SIZE		(L1_CACHE_BYTES - XPC_MSG_PAYLOAD_OFFSET)
+#define XPNET_MSG_SIZE		XPC_MSG_PAYLOAD_MAX_SIZE
 #define XPNET_MSG_DATA_MAX	\
-		(XPNET_MSG_SIZE - (u64)(&((struct xpnet_message *)0)->data))
-#define XPNET_MSG_ALIGNED_SIZE	(L1_CACHE_ALIGN(XPNET_MSG_SIZE))
-#define XPNET_MSG_NENTRIES	(PAGE_SIZE / XPNET_MSG_ALIGNED_SIZE)
+		(XPNET_MSG_SIZE - offsetof(struct xpnet_message, data))
+#define XPNET_MSG_NENTRIES	(PAGE_SIZE / XPC_MSG_MAX_SIZE)
 
 #define XPNET_MAX_KTHREADS	(XPNET_MSG_NENTRIES + 1)
 #define XPNET_MAX_IDLE_KTHREADS	(XPNET_MSG_NENTRIES + 1)
@@ -105,7 +91,6 @@ struct xpnet_message {
  * then be released.
  */
 struct xpnet_pending_msg {
-	struct list_head free_list;
 	struct sk_buff *skb;
 	atomic_t use_count;
 };
@@ -121,7 +106,7 @@ struct net_device *xpnet_device;
  * When we are notified of other partitions activating, we add them to
  * our bitmask of partitions to which we broadcast.
  */
-static u64 xpnet_broadcast_partitions;
+static unsigned long *xpnet_broadcast_partitions;
 /* protect above */
 static DEFINE_SPINLOCK(xpnet_broadcast_lock);
 
@@ -141,16 +126,13 @@ static DEFINE_SPINLOCK(xpnet_broadcast_lock);
 #define XPNET_DEF_MTU (0x8000UL)
 
 /*
- * The partition id is encapsulated in the MAC address.  The following
- * define locates the octet the partid is in.
+ * The partid is encapsulated in the MAC address beginning in the following
+ * octet and it consists of two octets.
  */
-#define XPNET_PARTID_OCTET	1
-#define XPNET_LICENSE_OCTET	2
+#define XPNET_PARTID_OCTET	2
+
+/* Define the XPNET debug device structures to be used with dev_dbg() et al */
 
-/*
- * Define the XPNET debug device structure that is to be used with dev_dbg(),
- * dev_err(), dev_warn(), and dev_info().
- */
 struct device_driver xpnet_dbg_name = {
 	.name = "xpnet"
 };
@@ -169,7 +151,8 @@ static void
 xpnet_receive(short partid, int channel, struct xpnet_message *msg)
 {
 	struct sk_buff *skb;
-	bte_result_t bret;
+	void *dst;
+	enum xp_retval ret;
 	struct xpnet_dev_private *priv =
 	    (struct xpnet_dev_private *)xpnet_device->priv;
 
@@ -201,7 +184,7 @@ xpnet_receive(short partid, int channel, struct xpnet_message *msg)
 
 	/*
 	 * The allocated skb has some reserved space.
-	 * In order to use bte_copy, we need to get the
+	 * In order to use xp_remote_memcpy(), we need to get the
 	 * skb->data pointer moved forward.
 	 */
 	skb_reserve(skb, (L1_CACHE_BYTES - ((u64)skb->data &
@@ -226,26 +209,21 @@ xpnet_receive(short partid, int channel, struct xpnet_message *msg)
 		skb_copy_to_linear_data(skb, &msg->data,
 					(size_t)msg->embedded_bytes);
 	} else {
+		dst = (void *)((u64)skb->data & ~(L1_CACHE_BYTES - 1));
 		dev_dbg(xpnet, "transferring buffer to the skb->data area;\n\t"
-			"bte_copy(0x%p, 0x%p, %hu)\n", (void *)msg->buf_pa,
-			(void *)__pa((u64)skb->data & ~(L1_CACHE_BYTES - 1)),
-			msg->size);
-
-		bret = bte_copy(msg->buf_pa,
-				__pa((u64)skb->data & ~(L1_CACHE_BYTES - 1)),
-				msg->size, (BTE_NOTIFY | BTE_WACQUIRE), NULL);
+			"xp_remote_memcpy(0x%p, 0x%p, %hu)\n", dst,
+					  (void *)msg->buf_pa, msg->size);
 
-		if (bret != BTE_SUCCESS) {
+		ret = xp_remote_memcpy(xp_pa(dst), msg->buf_pa, msg->size);
+		if (ret != xpSuccess) {
 			/*
-			 * >>> Need better way of cleaning skb.  Currently skb
-			 * >>> appears in_use and we can't just call
-			 * >>> dev_kfree_skb.
+			 * !!! Need better way of cleaning skb.  Currently skb
+			 * !!! appears in_use and we can't just call
+			 * !!! dev_kfree_skb.
 			 */
-			dev_err(xpnet, "bte_copy(0x%p, 0x%p, 0x%hx) returned "
-				"error=0x%x\n", (void *)msg->buf_pa,
-				(void *)__pa((u64)skb->data &
-					     ~(L1_CACHE_BYTES - 1)),
-				msg->size, bret);
+			dev_err(xpnet, "xp_remote_memcpy(0x%p, 0x%p, 0x%hx) "
+				"returned error=0x%x\n", dst,
+				(void *)msg->buf_pa, msg->size, ret);
 
 			xpc_received(partid, channel, (void *)msg);
 
@@ -285,9 +263,7 @@ static void
 xpnet_connection_activity(enum xp_retval reason, short partid, int channel,
 			  void *data, void *key)
 {
-	long bp;
-
-	DBUG_ON(partid <= 0 || partid >= XP_MAX_PARTITIONS);
+	DBUG_ON(partid < 0 || partid >= xp_max_npartitions);
 	DBUG_ON(channel != XPC_NET_CHANNEL);
 
 	switch (reason) {
@@ -299,31 +275,28 @@ xpnet_connection_activity(enum xp_retval reason, short partid, int channel,
 
 	case xpConnected:	/* connection completed to a partition */
 		spin_lock_bh(&xpnet_broadcast_lock);
-		xpnet_broadcast_partitions |= 1UL << (partid - 1);
-		bp = xpnet_broadcast_partitions;
+		__set_bit(partid, xpnet_broadcast_partitions);
 		spin_unlock_bh(&xpnet_broadcast_lock);
 
 		netif_carrier_on(xpnet_device);
 
-		dev_dbg(xpnet, "%s connection created to partition %d; "
-			"xpnet_broadcast_partitions=0x%lx\n",
-			xpnet_device->name, partid, bp);
+		dev_dbg(xpnet, "%s connected to partition %d\n",
+			xpnet_device->name, partid);
 		break;
 
 	default:
 		spin_lock_bh(&xpnet_broadcast_lock);
-		xpnet_broadcast_partitions &= ~(1UL << (partid - 1));
-		bp = xpnet_broadcast_partitions;
+		__clear_bit(partid, xpnet_broadcast_partitions);
 		spin_unlock_bh(&xpnet_broadcast_lock);
 
-		if (bp == 0)
+		if (bitmap_empty((unsigned long *)xpnet_broadcast_partitions,
+				 xp_max_npartitions)) {
 			netif_carrier_off(xpnet_device);
+		}
 
-		dev_dbg(xpnet, "%s disconnected from partition %d; "
-			"xpnet_broadcast_partitions=0x%lx\n",
-			xpnet_device->name, partid, bp);
+		dev_dbg(xpnet, "%s disconnected from partition %d\n",
+			xpnet_device->name, partid);
 		break;
-
 	}
 }
 
@@ -334,8 +307,10 @@ xpnet_dev_open(struct net_device *dev)
 
 	dev_dbg(xpnet, "calling xpc_connect(%d, 0x%p, NULL, %ld, %ld, %ld, "
 		"%ld)\n", XPC_NET_CHANNEL, xpnet_connection_activity,
-		XPNET_MSG_SIZE, XPNET_MSG_NENTRIES, XPNET_MAX_KTHREADS,
-		XPNET_MAX_IDLE_KTHREADS);
+		(unsigned long)XPNET_MSG_SIZE,
+		(unsigned long)XPNET_MSG_NENTRIES,
+		(unsigned long)XPNET_MAX_KTHREADS,
+		(unsigned long)XPNET_MAX_IDLE_KTHREADS);
 
 	ret = xpc_connect(XPC_NET_CHANNEL, xpnet_connection_activity, NULL,
 			  XPNET_MSG_SIZE, XPNET_MSG_NENTRIES,
@@ -426,35 +401,74 @@ xpnet_send_completed(enum xp_retval reason, short partid, int channel,
 	}
 }
 
+static void
+xpnet_send(struct sk_buff *skb, struct xpnet_pending_msg *queued_msg,
+	   u64 start_addr, u64 end_addr, u16 embedded_bytes, int dest_partid)
+{
+	u8 msg_buffer[XPNET_MSG_SIZE];
+	struct xpnet_message *msg = (struct xpnet_message *)&msg_buffer;
+	u16 msg_size = sizeof(struct xpnet_message);
+	enum xp_retval ret;
+
+	msg->embedded_bytes = embedded_bytes;
+	if (unlikely(embedded_bytes != 0)) {
+		msg->version = XPNET_VERSION_EMBED;
+		dev_dbg(xpnet, "calling memcpy(0x%p, 0x%p, 0x%lx)\n",
+			&msg->data, skb->data, (size_t)embedded_bytes);
+		skb_copy_from_linear_data(skb, &msg->data,
+					  (size_t)embedded_bytes);
+		msg_size += embedded_bytes - 1;
+	} else {
+		msg->version = XPNET_VERSION;
+	}
+	msg->magic = XPNET_MAGIC;
+	msg->size = end_addr - start_addr;
+	msg->leadin_ignore = (u64)skb->data - start_addr;
+	msg->tailout_ignore = end_addr - (u64)skb_tail_pointer(skb);
+	msg->buf_pa = xp_pa((void *)start_addr);
+
+	dev_dbg(xpnet, "sending XPC message to %d:%d\n"
+		KERN_DEBUG "msg->buf_pa=0x%lx, msg->size=%u, "
+		"msg->leadin_ignore=%u, msg->tailout_ignore=%u\n",
+		dest_partid, XPC_NET_CHANNEL, msg->buf_pa, msg->size,
+		msg->leadin_ignore, msg->tailout_ignore);
+
+	atomic_inc(&queued_msg->use_count);
+
+	ret = xpc_send_notify(dest_partid, XPC_NET_CHANNEL, XPC_NOWAIT, msg,
+			      msg_size, xpnet_send_completed, queued_msg);
+	if (unlikely(ret != xpSuccess))
+		atomic_dec(&queued_msg->use_count);
+}
+
 /*
  * Network layer has formatted a packet (skb) and is ready to place it
  * "on the wire".  Prepare and send an xpnet_message to all partitions
  * which have connected with us and are targets of this packet.
  *
  * MAC-NOTE:  For the XPNET driver, the MAC address contains the
- * destination partition_id.  If the destination partition id word
- * is 0xff, this packet is to broadcast to all partitions.
+ * destination partid.  If the destination partid octets are 0xffff,
+ * this packet is to be broadcast to all connected partitions.
  */
 static int
 xpnet_dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	struct xpnet_pending_msg *queued_msg;
-	enum xp_retval ret;
-	struct xpnet_message *msg;
 	u64 start_addr, end_addr;
-	long dp;
-	u8 second_mac_octet;
 	short dest_partid;
-	struct xpnet_dev_private *priv;
-	u16 embedded_bytes;
-
-	priv = (struct xpnet_dev_private *)dev->priv;
+	struct xpnet_dev_private *priv = (struct xpnet_dev_private *)dev->priv;
+	u16 embedded_bytes = 0;
 
 	dev_dbg(xpnet, ">skb->head=0x%p skb->data=0x%p skb->tail=0x%p "
 		"skb->end=0x%p skb->len=%d\n", (void *)skb->head,
 		(void *)skb->data, skb_tail_pointer(skb), skb_end_pointer(skb),
 		skb->len);
 
+	if (skb->data[0] == 0x33) {
+		dev_kfree_skb(skb);
+		return 0;	/* nothing needed to be done */
+	}
+
 	/*
 	 * The xpnet_pending_msg tracks how many outstanding
 	 * xpc_send_notifies are relying on this skb.  When none
@@ -466,7 +480,6 @@ xpnet_dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
 			 "packet\n", sizeof(struct xpnet_pending_msg));
 
 		priv->stats.tx_errors++;
-
 		return -ENOMEM;
 	}
 
@@ -475,7 +488,6 @@ xpnet_dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
 	end_addr = L1_CACHE_ALIGN((u64)skb_tail_pointer(skb));
 
 	/* calculate how many bytes to embed in the XPC message */
-	embedded_bytes = 0;
 	if (unlikely(skb->len <= XPNET_MSG_DATA_MAX)) {
 		/* skb->data does fit so embed */
 		embedded_bytes = skb->len;
@@ -491,82 +503,28 @@ xpnet_dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
 	atomic_set(&queued_msg->use_count, 1);
 	queued_msg->skb = skb;
 
-	second_mac_octet = skb->data[XPNET_PARTID_OCTET];
-	if (second_mac_octet == 0xff) {
+	if (skb->data[0] == 0xff) {
 		/* we are being asked to broadcast to all partitions */
-		dp = xpnet_broadcast_partitions;
-	} else if (second_mac_octet != 0) {
-		dp = xpnet_broadcast_partitions &
-		    (1UL << (second_mac_octet - 1));
-	} else {
-		/* 0 is an invalid partid.  Ignore */
-		dp = 0;
-	}
-	dev_dbg(xpnet, "destination Partitions mask (dp) = 0x%lx\n", dp);
-
-	/*
-	 * If we wanted to allow promiscuous mode to work like an
-	 * unswitched network, this would be a good point to OR in a
-	 * mask of partitions which should be receiving all packets.
-	 */
-
-	/*
-	 * Main send loop.
-	 */
-	for (dest_partid = 1; dp && dest_partid < XP_MAX_PARTITIONS;
-	     dest_partid++) {
+		for_each_bit(dest_partid, xpnet_broadcast_partitions,
+			     xp_max_npartitions) {
 
-		if (!(dp & (1UL << (dest_partid - 1)))) {
-			/* not destined for this partition */
-			continue;
+			xpnet_send(skb, queued_msg, start_addr, end_addr,
+				   embedded_bytes, dest_partid);
 		}
+	} else {
+		dest_partid = (short)skb->data[XPNET_PARTID_OCTET + 1];
+		dest_partid |= (short)skb->data[XPNET_PARTID_OCTET + 0] << 8;
 
-		/* remove this partition from the destinations mask */
-		dp &= ~(1UL << (dest_partid - 1));
-
-		/* found a partition to send to */
-
-		ret = xpc_allocate(dest_partid, XPC_NET_CHANNEL,
-				   XPC_NOWAIT, (void **)&msg);
-		if (unlikely(ret != xpSuccess))
-			continue;
-
-		msg->embedded_bytes = embedded_bytes;
-		if (unlikely(embedded_bytes != 0)) {
-			msg->version = XPNET_VERSION_EMBED;
-			dev_dbg(xpnet, "calling memcpy(0x%p, 0x%p, 0x%lx)\n",
-				&msg->data, skb->data, (size_t)embedded_bytes);
-			skb_copy_from_linear_data(skb, &msg->data,
-						  (size_t)embedded_bytes);
-		} else {
-			msg->version = XPNET_VERSION;
-		}
-		msg->magic = XPNET_MAGIC;
-		msg->size = end_addr - start_addr;
-		msg->leadin_ignore = (u64)skb->data - start_addr;
-		msg->tailout_ignore = end_addr - (u64)skb_tail_pointer(skb);
-		msg->buf_pa = __pa(start_addr);
-
-		dev_dbg(xpnet, "sending XPC message to %d:%d\n"
-			KERN_DEBUG "msg->buf_pa=0x%lx, msg->size=%u, "
-			"msg->leadin_ignore=%u, msg->tailout_ignore=%u\n",
-			dest_partid, XPC_NET_CHANNEL, msg->buf_pa, msg->size,
-			msg->leadin_ignore, msg->tailout_ignore);
-
-		atomic_inc(&queued_msg->use_count);
-
-		ret = xpc_send_notify(dest_partid, XPC_NET_CHANNEL, msg,
-				      xpnet_send_completed, queued_msg);
-		if (unlikely(ret != xpSuccess)) {
-			atomic_dec(&queued_msg->use_count);
-			continue;
+		if (dest_partid >= 0 &&
+		    dest_partid < xp_max_npartitions &&
+		    test_bit(dest_partid, xpnet_broadcast_partitions) != 0) {
+
+			xpnet_send(skb, queued_msg, start_addr, end_addr,
+				   embedded_bytes, dest_partid);
 		}
 	}
 
 	if (atomic_dec_return(&queued_msg->use_count) == 0) {
-		dev_dbg(xpnet, "no partitions to receive packet destined for "
-			"%d\n", dest_partid);
-
 		dev_kfree_skb(skb);
 		kfree(queued_msg);
 	}
@@ -594,23 +552,28 @@ xpnet_dev_tx_timeout(struct net_device *dev)
 static int __init
 xpnet_init(void)
 {
-	int i;
-	u32 license_num;
-	int result = -ENOMEM;
+	int result;
 
-	if (!ia64_platform_is("sn2"))
+	if (!is_shub() && !is_uv())
 		return -ENODEV;
 
 	dev_info(xpnet, "registering network device %s\n", XPNET_DEVICE_NAME);
 
+	xpnet_broadcast_partitions = kzalloc(BITS_TO_LONGS(xp_max_npartitions) *
+					     sizeof(long), GFP_KERNEL);
+	if (xpnet_broadcast_partitions == NULL)
+		return -ENOMEM;
+
 	/*
 	 * use ether_setup() to init the majority of our device
 	 * structure and then override the necessary pieces.
 	 */
 	xpnet_device = alloc_netdev(sizeof(struct xpnet_dev_private),
 				    XPNET_DEVICE_NAME, ether_setup);
-	if (xpnet_device == NULL)
+	if (xpnet_device == NULL) {
+		kfree(xpnet_broadcast_partitions);
 		return -ENOMEM;
+	}
 
 	netif_carrier_off(xpnet_device);
 
@@ -628,14 +591,10 @@ xpnet_init(void)
 	 * MAC addresses.  We chose the first octet of the MAC to be unlikely
 	 * to collide with any vendor's officially issued MAC.
 	 */
-	xpnet_device->dev_addr[0] = 0xfe;
-	xpnet_device->dev_addr[XPNET_PARTID_OCTET] = sn_partition_id;
-	license_num = sn_partition_serial_number_val();
-	for (i = 3; i >= 0; i--) {
-		xpnet_device->dev_addr[XPNET_LICENSE_OCTET + i] =
-		    license_num & 0xff;
-		license_num = license_num >> 8;
-	}
+	xpnet_device->dev_addr[0] = 0x02;     /* locally administered, no OUI */
+
+	xpnet_device->dev_addr[XPNET_PARTID_OCTET + 1] = xp_partition_id;
+	xpnet_device->dev_addr[XPNET_PARTID_OCTET + 0] = (xp_partition_id >> 8);
 
 	/*
 	 * ether_setup() sets this to a multicast device.  We are
@@ -651,8 +610,10 @@ xpnet_init(void)
 	xpnet_device->features = NETIF_F_NO_CSUM;
 
 	result = register_netdev(xpnet_device);
-	if (result != 0)
+	if (result != 0) {
 		free_netdev(xpnet_device);
+		kfree(xpnet_broadcast_partitions);
+	}
 
 	return result;
 }
@@ -666,8 +627,8 @@ xpnet_exit(void)
 		 xpnet_device[0].name);
 
 	unregister_netdev(xpnet_device);
-
 	free_netdev(xpnet_device);
+	kfree(xpnet_broadcast_partitions);
 }
 
 module_exit(xpnet_exit);