diff options
Diffstat (limited to 'drivers/misc/sgi-xp/xpc_sn2.c')
| -rw-r--r-- | drivers/misc/sgi-xp/xpc_sn2.c | 2404 |
1 files changed, 2404 insertions, 0 deletions
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(¬ify->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(¬ify->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); +} |