sgi-xp: isolate xpc_vars structure to sn2 only

Isolate the xpc_vars structure of XPC's reserved page to sn2 only.

Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

6 files changed, 1433 insertions, 1255 deletions

diff --git a/drivers/misc/sgi-xp/xpc.h b/drivers/misc/sgi-xp/xpc.h
index e8c2a162960..a3a67485cf8 100644
--- a/drivers/misc/sgi-xp/xpc.h
+++ b/drivers/misc/sgi-xp/xpc.h
@@ -159,10 +159,10 @@ 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;
@@ -176,46 +176,23 @@ struct xpc_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).
+ * The following pertains to ia64-sn2 only.
+ *
+ * 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) to identify
+ * the senders of ACTIVATE IRQs, and 2 AMO variables to identify which remote
+ * partitions (i.e., XPCs) consider themselves currently engaged with the
+ * local XPC.
  */
-#define XPC_NOTIFY_IRQ_AMOS	   0
-#define XPC_ACTIVATE_IRQ_AMOS	   (XPC_NOTIFY_IRQ_AMOS + XP_MAX_NPARTITIONS_SN2)
+#define XPC_NOTIFY_IRQ_AMOS	0
+#define XPC_ACTIVATE_IRQ_AMOS	(XPC_NOTIFY_IRQ_AMOS + XP_MAX_NPARTITIONS_SN2)
 #define XPC_ENGAGED_PARTITIONS_AMO (XPC_ACTIVATE_IRQ_AMOS + XP_NASID_MASK_WORDS)
 #define XPC_DISENGAGE_REQUEST_AMO  (XPC_ENGAGED_PARTITIONS_AMO + 1)
 
@@ -259,11 +236,11 @@ struct xpc_vars_part_sn2 {
 /* 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) + \
+#define XPC_RP_VARS(_rp)	((struct xpc_vars_sn2 *)(XPC_RP_MACH_NASIDS(_rp) + \
 				    xp_nasid_mask_words))
 
 /*
@@ -344,6 +321,7 @@ struct xpc_notify {
  * allocated at the time a partition becomes active. The array contains one
  * of these structures for each potential channel connection to that partition.
  *
+>>> sn2 only!!!
  * Each of these structures 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
@@ -622,6 +600,9 @@ extern struct device *xpc_part;
 extern struct device *xpc_chan;
 extern int xpc_disengage_request_timelimit;
 extern int xpc_disengage_request_timedout;
+extern atomic_t xpc_act_IRQ_rcvd;
+extern wait_queue_head_t xpc_act_IRQ_wq;
+extern void *xpc_heartbeating_to_mask;
 extern irqreturn_t xpc_notify_IRQ_handler(int, void *);
 extern void xpc_dropped_IPI_check(struct xpc_partition *);
 extern void xpc_activate_partition(struct xpc_partition *);
@@ -629,15 +610,48 @@ 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 enum xp_retval (*xpc_rsvd_page_init) (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 void (*xpc_check_remote_hb) (void);
 extern enum xp_retval (*xpc_make_first_contact) (struct xpc_partition *);
 extern u64 (*xpc_get_IPI_flags) (struct xpc_partition *);
 extern struct xpc_msg *(*xpc_get_deliverable_msg) (struct xpc_channel *);
+extern void (*xpc_initiate_partition_activation) (struct xpc_rsvd_page *, u64,
+						  int);
+extern void (*xpc_process_act_IRQ_rcvd) (int);
 extern enum xp_retval (*xpc_setup_infrastructure) (struct xpc_partition *);
 extern void (*xpc_teardown_infrastructure) (struct xpc_partition *);
+extern void (*xpc_mark_partition_engaged) (struct xpc_partition *);
+extern void (*xpc_mark_partition_disengaged) (struct xpc_partition *);
+extern void (*xpc_request_partition_disengage) (struct xpc_partition *);
+extern void (*xpc_cancel_partition_disengage_request) (struct xpc_partition *);
+extern u64 (*xpc_partition_engaged) (u64);
+extern u64 (*xpc_partition_disengage_requested) (u64);;
+extern void (*xpc_clear_partition_engaged) (u64);
+extern void (*xpc_clear_partition_disengage_request) (u64);
+
+extern void (*xpc_IPI_send_local_activate) (int);
+extern void (*xpc_IPI_send_activated) (struct xpc_partition *);
+extern void (*xpc_IPI_send_local_reactivate) (int);
+extern void (*xpc_IPI_send_disengage) (struct xpc_partition *);
+
+extern void (*xpc_IPI_send_closerequest) (struct xpc_channel *,
+					  unsigned long *);
+extern void (*xpc_IPI_send_closereply) (struct xpc_channel *, unsigned long *);
+extern void (*xpc_IPI_send_openrequest) (struct xpc_channel *, unsigned long *);
+extern void (*xpc_IPI_send_openreply) (struct xpc_channel *, unsigned long *);
+
+extern enum xp_retval (*xpc_allocate_msg) (struct xpc_channel *, u32,
+					   struct xpc_msg **);
+extern enum xp_retval (*xpc_send_msg) (struct xpc_channel *, struct xpc_msg *,
+				       u8, xpc_notify_func, void *);
+extern void (*xpc_received_msg) (struct xpc_channel *, struct xpc_msg *);
 
 /* found in xpc_sn2.c */
 extern void xpc_init_sn2(void);
-extern struct xpc_vars *xpc_vars;		/*>>> eliminate from here */
 
 /* found in xpc_uv.c */
 extern void xpc_init_uv(void);
@@ -646,6 +660,7 @@ extern void xpc_init_uv(void);
 extern int xpc_exiting;
 extern int xp_nasid_mask_words;
 extern struct xpc_rsvd_page *xpc_rsvd_page;
+extern u64 *xpc_mach_nasids;
 extern struct xpc_partition *xpc_partitions;
 extern char *xpc_remote_copy_buffer;
 extern void *xpc_remote_copy_buffer_base;
@@ -658,7 +673,8 @@ 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, u64 *, struct xpc_rsvd_page *,
+					u64 *);
 extern void xpc_deactivate_partition(const int, struct xpc_partition *,
 				     enum xp_retval);
 extern enum xp_retval xpc_initiate_partid_to_nasids(short, void *);
@@ -667,6 +683,7 @@ extern enum xp_retval xpc_initiate_partid_to_nasids(short, void *);
 extern void *xpc_kzalloc_cacheline_aligned(size_t, gfp_t, void **);
 extern void xpc_initiate_connect(int);
 extern void xpc_initiate_disconnect(int);
+extern enum xp_retval xpc_allocate_msg_wait(struct xpc_channel *);
 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 *,
@@ -680,6 +697,40 @@ extern void xpc_disconnect_channel(const int, struct xpc_channel *,
 extern void xpc_disconnect_callout(struct xpc_channel *, enum xp_retval);
 extern void xpc_partition_going_down(struct xpc_partition *, enum xp_retval);
 
+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)
 {
@@ -749,297 +800,7 @@ xpc_part_ref(struct xpc_partition *part)
 	}
 
 /*
- * 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
+ * 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
@@ -1052,107 +813,11 @@ xpc_notify_IRQ_send_local(struct xpc_channel *ch, u8 ipi_flag,
 #define	XPC_IPI_OPENREPLY	0x08
 #define	XPC_IPI_MSGREQUEST	0x10
 
-/* given an AMO variable and a channel#, get its associated IPI flags */
+/* 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);
-}
-
-/*
->>> this block comment needs to be moved and re-written.
- * 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) 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;
-}
-
-/*
- * 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 8081e8155df..26c5e12c122 100644
--- a/drivers/misc/sgi-xp/xpc_channel.c
+++ b/drivers/misc/sgi-xp/xpc_channel.c
@@ -1165,7 +1165,7 @@ 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;
@@ -1193,96 +1193,6 @@ 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.
  *
@@ -1318,144 +1228,6 @@ xpc_initiate_allocate(short partid, int ch_number, u32 flags, void **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 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.
  *
@@ -1586,66 +1358,6 @@ 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
@@ -1668,35 +1380,12 @@ 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_npartitions);
 	DBUG_ON(ch_number < 0 || ch_number >= part->nchannels);
 
 	ch = &part->channels[ch_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->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);
+	xpc_received_msg(ch, msg);
 
 	/* the call to xpc_msgqueue_ref() was done by xpc_deliver_msg()  */
 	xpc_msgqueue_deref(ch);
diff --git a/drivers/misc/sgi-xp/xpc_main.c b/drivers/misc/sgi-xp/xpc_main.c
index be3a4853930..10dac3652b2 100644
--- a/drivers/misc/sgi-xp/xpc_main.c
+++ b/drivers/misc/sgi-xp/xpc_main.c
@@ -148,12 +148,14 @@ static struct ctl_table_header *xpc_sysctl;
 int xpc_disengage_request_timedout;
 
 /* #of IRQs received */
-static atomic_t xpc_act_IRQ_rcvd;
+atomic_t xpc_act_IRQ_rcvd;
 
 /* IRQ handler notifies this wait queue on receipt of an IRQ */
-static DECLARE_WAIT_QUEUE_HEAD(xpc_act_IRQ_wq);