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-rw-r--r--drivers/misc/sgi-xp/xp_main.c290
1 files changed, 290 insertions, 0 deletions
diff --git a/drivers/misc/sgi-xp/xp_main.c b/drivers/misc/sgi-xp/xp_main.c
new file mode 100644
index 00000000000..5f9f9c2e929
--- /dev/null
+++ b/drivers/misc/sgi-xp/xp_main.c
@@ -0,0 +1,290 @@
+/*
+ * 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) 2004-2008 Silicon Graphics, Inc. All Rights Reserved.
+ */
+
+
+/*
+ * Cross Partition (XP) base.
+ *
+ * XP provides a base from which its users can interact
+ * with XPC, yet not be dependent on XPC.
+ *
+ */
+
+
+#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 "xp.h"
+
+
+/*
+ * Target of nofault PIO read.
+ */
+u64 xp_nofault_PIOR_target;
+
+
+/*
+ * xpc_registrations[] keeps track of xpc_connect()'s done by the kernel-level
+ * users of XPC.
+ */
+struct xpc_registration xpc_registrations[XPC_NCHANNELS];
+
+
+/*
+ * Initialize the XPC interface to indicate that XPC isn't loaded.
+ */
+static enum xpc_retval xpc_notloaded(void) { return xpcNotLoaded; }
+
+struct xpc_interface xpc_interface = {
+ (void (*)(int)) xpc_notloaded,
+ (void (*)(int)) xpc_notloaded,
+ (enum xpc_retval (*)(partid_t, int, u32, void **)) xpc_notloaded,
+ (enum xpc_retval (*)(partid_t, int, void *)) xpc_notloaded,
+ (enum xpc_retval (*)(partid_t, int, void *, xpc_notify_func, void *))
+ xpc_notloaded,
+ (void (*)(partid_t, int, void *)) xpc_notloaded,
+ (enum xpc_retval (*)(partid_t, void *)) xpc_notloaded
+};
+
+
+/*
+ * XPC calls this when it (the XPC module) has been loaded.
+ */
+void
+xpc_set_interface(void (*connect)(int),
+ void (*disconnect)(int),
+ enum xpc_retval (*allocate)(partid_t, int, u32, void **),
+ enum xpc_retval (*send)(partid_t, int, void *),
+ enum xpc_retval (*send_notify)(partid_t, int, void *,
+ xpc_notify_func, void *),
+ void (*received)(partid_t, int, void *),
+ enum xpc_retval (*partid_to_nasids)(partid_t, 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;
+ xpc_interface.partid_to_nasids = partid_to_nasids;
+}
+
+
+/*
+ * XPC calls this when it (the XPC module) is being unloaded.
+ */
+void
+xpc_clear_interface(void)
+{
+ xpc_interface.connect = (void (*)(int)) xpc_notloaded;
+ xpc_interface.disconnect = (void (*)(int)) xpc_notloaded;
+ xpc_interface.allocate = (enum xpc_retval (*)(partid_t, int, u32,
+ void **)) xpc_notloaded;
+ xpc_interface.send = (enum xpc_retval (*)(partid_t, int, void *))
+ xpc_notloaded;
+ xpc_interface.send_notify = (enum xpc_retval (*)(partid_t, int, void *,
+ xpc_notify_func, void *)) xpc_notloaded;
+ xpc_interface.received = (void (*)(partid_t, int, void *))
+ xpc_notloaded;
+ xpc_interface.partid_to_nasids = (enum xpc_retval (*)(partid_t, void *))
+ xpc_notloaded;
+}
+
+
+/*
+ * Register for automatic establishment of a channel connection whenever
+ * a partition comes up.
+ *
+ * Arguments:
+ *
+ * ch_number - channel # to register for connection.
+ * func - function to call for asynchronous notification of channel
+ * state changes (i.e., connection, disconnection, error) and
+ * the arrival of incoming messages.
+ * key - pointer to optional user-defined value that gets passed back
+ * to the user on any callouts made to func.
+ * payload_size - size in bytes of the XPC message's payload area which
+ * contains a user-defined message. The user should make
+ * this large enough to hold their largest message.
+ * nentries - max #of XPC message entries a message queue can contain.
+ * The actual number, which is determined when a connection
+ * is established and may be less then requested, will be
+ * passed to the user via the xpcConnected callout.
+ * assigned_limit - max number of kthreads allowed to be processing
+ * messages (per connection) at any given instant.
+ * idle_limit - max number of kthreads allowed to be idle at any given
+ * instant.
+ */
+enum xpc_retval
+xpc_connect(int ch_number, xpc_channel_func func, void *key, u16 payload_size,
+ u16 nentries, u32 assigned_limit, u32 idle_limit)
+{
+ struct xpc_registration *registration;
+
+
+ DBUG_ON(ch_number < 0 || ch_number >= XPC_NCHANNELS);
+ DBUG_ON(payload_size == 0 || nentries == 0);
+ DBUG_ON(func == NULL);
+ DBUG_ON(assigned_limit == 0 || idle_limit > assigned_limit);
+
+ registration = &xpc_registrations[ch_number];
+
+ if (mutex_lock_interruptible(&registration->mutex) != 0) {
+ return xpcInterrupted;
+ }
+
+ /* if XPC_CHANNEL_REGISTERED(ch_number) */
+ if (registration->func != NULL) {
+ mutex_unlock(&registration->mutex);
+ return xpcAlreadyRegistered;
+ }
+
+ /* register the channel for connection */
+ registration->msg_size = XPC_MSG_SIZE(payload_size);
+ registration->nentries = nentries;
+ registration->assigned_limit = assigned_limit;
+ registration->idle_limit = idle_limit;
+ registration->key = key;
+ registration->func = func;
+
+ mutex_unlock(&registration->mutex);
+
+ xpc_interface.connect(ch_number);
+
+ return xpcSuccess;
+}
+
+
+/*
+ * Remove the registration for automatic connection of the specified channel
+ * when a partition comes up.
+ *
+ * Before returning this xpc_disconnect() will wait for all connections on the
+ * specified channel have been closed/torndown. So the caller can be assured
+ * that they will not be receiving any more callouts from XPC to their
+ * function registered via xpc_connect().
+ *
+ * Arguments:
+ *
+ * ch_number - channel # to unregister.
+ */
+void
+xpc_disconnect(int ch_number)
+{
+ struct xpc_registration *registration;
+
+
+ DBUG_ON(ch_number < 0 || ch_number >= XPC_NCHANNELS);
+
+ registration = &xpc_registrations[ch_number];
+
+ /*
+ * We've decided not to make this a down_interruptible(), since we
+ * figured XPC's users will just turn around and call xpc_disconnect()
+ * again anyways, so we might as well wait, if need be.
+ */
+ mutex_lock(&registration->mutex);
+
+ /* if !XPC_CHANNEL_REGISTERED(ch_number) */
+ if (registration->func == NULL) {
+ mutex_unlock(&registration->mutex);
+ return;
+ }
+
+ /* remove the connection registration for the specified channel */
+ registration->func = NULL;
+ registration->key = NULL;
+ registration->nentries = 0;
+ registration->msg_size = 0;
+ registration->assigned_limit = 0;
+ registration->idle_limit = 0;
+
+ xpc_interface.disconnect(ch_number);
+
+ mutex_unlock(&registration->mutex);
+
+ return;
+}
+
+
+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;
+ }
+
+ /*
+ * 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).
+ */
+ if ((ret = sn_register_nofault_code(func_addr, err_func_addr,
+ err_func_addr, 1, 1)) != 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;
+ } else {
+ xp_nofault_PIOR_target = SH1_IPI_ACCESS;
+ }
+
+ /* initialize the connection registration mutex */
+ for (ch_number = 0; ch_number < XPC_NCHANNELS; ch_number++) {
+ mutex_init(&xpc_registrations[ch_number].mutex);
+ }
+
+ return 0;
+}
+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);
+}
+module_exit(xp_exit);
+
+
+MODULE_AUTHOR("Silicon Graphics, Inc.");
+MODULE_DESCRIPTION("Cross Partition (XP) base");
+MODULE_LICENSE("GPL");
+
+EXPORT_SYMBOL(xp_nofault_PIOR);
+EXPORT_SYMBOL(xp_nofault_PIOR_target);
+EXPORT_SYMBOL(xpc_registrations);
+EXPORT_SYMBOL(xpc_interface);
+EXPORT_SYMBOL(xpc_clear_interface);
+EXPORT_SYMBOL(xpc_set_interface);
+EXPORT_SYMBOL(xpc_connect);
+EXPORT_SYMBOL(xpc_disconnect);
+