sgi-xp: isolate additional sn2 specific code

Move additional sn2 specific code into xpc_sn2.c.

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>
diff --git a/drivers/misc/sgi-xp/xpc.h b/drivers/misc/sgi-xp/xpc.h
index 1edf375..b04cfbe 100644
--- a/drivers/misc/sgi-xp/xpc.h
+++ b/drivers/misc/sgi-xp/xpc.h
@@ -122,9 +122,6 @@
 
 #define XPC_RP_VERSION _XPC_VERSION(2, 0) /* version 2.0 of the reserved page */
 
-#define XPC_SUPPORTS_RP_STAMP(_version) \
-			(_version >= _XPC_VERSION(1, 1))
-
 /*
  * Define the structures by which XPC variables can be exported to other
  * partitions. (There are two: struct xpc_vars and struct xpc_vars_part)
@@ -144,8 +141,8 @@
 	u64 heartbeat;
 	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;
+	int activate_IRQ_nasid;
+	int activate_IRQ_phys_cpuid;
 	u64 vars_part_pa;
 	u64 amos_page_pa;	/* paddr of page of AMOs from MSPEC driver */
 	AMO_t *amos_page;	/* vaddr of page of AMOs from MSPEC driver */
@@ -153,9 +150,6 @@
 
 #define XPC_V_VERSION _XPC_VERSION(3, 1)    /* version 3.1 of the cross vars */
 
-#define XPC_SUPPORTS_DISENGAGE_REQUEST(_version) \
-			(_version >= _XPC_VERSION(3, 1))
-
 /*
  * The following pertains to ia64-sn2 only.
  *
@@ -167,14 +161,14 @@
  * 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
+ * the senders of ACTIVATE IRQs, 1 AMO variable to identify which remote
  * partitions (i.e., XPCs) consider themselves currently engaged with the
- * local XPC.
+ * local XPC and 1 AMO variable to request partition deactivation.
  */
 #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)
+#define XPC_DEACTIVATE_REQUEST_AMO  (XPC_ENGAGED_PARTITIONS_AMO + 1)
 
 /*
  * The following structure describes the per partition specific variables.
@@ -369,6 +363,23 @@
  *	new messages, by the clearing of the message flags of the acknowledged
  *	messages.
  */
+struct xpc_channel_sn2 {
+
+	/* various flavors of local and remote Get/Put values */
+
+	struct xpc_gp *local_GP;	/* local Get/Put values */
+	struct xpc_gp remote_GP;	/* remote Get/Put values */
+	struct xpc_gp w_local_GP;	/* working local Get/Put values */
+	struct xpc_gp w_remote_GP;	/* working remote Get/Put values */
+	s64 next_msg_to_pull;	/* Put value of next msg to pull */
+
+	struct mutex msg_to_pull_mutex;	/* next msg to pull serialization */
+};
+
+struct xpc_channel_uv {
+	/* >>> code is coming */
+};
+
 struct xpc_channel {
 	short partid;		/* ID of remote partition connected */
 	spinlock_t lock;	/* lock for updating this structure */
@@ -407,20 +418,11 @@
 	xpc_channel_func func;	/* user's channel function */
 	void *key;		/* pointer to user's key */
 
-	struct mutex msg_to_pull_mutex;	/* next msg to pull serialization */
 	struct completion wdisconnect_wait;    /* wait for channel disconnect */
 
 	struct xpc_openclose_args *local_openclose_args; /* args passed on */
 					     /* opening or closing of channel */
 
-	/* various flavors of local and remote Get/Put values */
-
-	struct xpc_gp *local_GP;	/* local Get/Put values */
-	struct xpc_gp remote_GP;	/* remote Get/Put values */
-	struct xpc_gp w_local_GP;	/* working local Get/Put values */
-	struct xpc_gp w_remote_GP;	/* working remote Get/Put values */
-	s64 next_msg_to_pull;	/* Put value of next msg to pull */
-
 	/* kthread management related fields */
 
 	atomic_t kthreads_assigned;	/* #of kthreads assigned to channel */
@@ -431,6 +433,11 @@
 
 	wait_queue_head_t idle_wq;	/* idle kthread wait queue */
 
+	union {
+		struct xpc_channel_sn2 sn2;
+		struct xpc_channel_uv uv;
+	} sn;
+
 } ____cacheline_aligned;
 
 /* struct xpc_channel flags */
@@ -467,6 +474,40 @@
  * for each partition (a partition will never utilize the structure that
  * represents itself).
  */
+
+struct xpc_partition_sn2 {
+	u64 remote_amos_page_pa;	/* phys addr of partition's amos page */
+	int activate_IRQ_nasid;	/* active partition's act/deact nasid */
+	int activate_IRQ_phys_cpuid;	/* active part's act/deact phys cpuid */
+
+	u64 remote_vars_pa;	/* phys addr of partition's vars */
+	u64 remote_vars_part_pa;	/* phys addr of partition's vars part */
+	u8 remote_vars_version;	/* version# of partition's vars */
+
+	void *local_GPs_base;	/* base address of kmalloc'd space */
+	struct xpc_gp *local_GPs;	/* local Get/Put values */
+	void *remote_GPs_base;	/* base address of kmalloc'd space */
+	struct xpc_gp *remote_GPs;	/* copy of remote partition's local */
+					/* Get/Put values */
+	u64 remote_GPs_pa;	/* phys address of remote partition's local */
+				/* Get/Put values */
+
+	u64 remote_openclose_args_pa;	/* phys addr of remote's args */
+
+	int remote_IPI_nasid;	/* nasid of where to send IPIs */
+	int remote_IPI_phys_cpuid;	/* phys CPU ID of where to send IPIs */
+	char IPI_owner[8];	/* IPI owner's name */
+
+	AMO_t *remote_IPI_amo_va;    /* address of remote IPI AMO_t structure */
+	AMO_t *local_IPI_amo_va;	/* address of IPI AMO_t structure */
+
+	struct timer_list dropped_notify_IRQ_timer;	/* dropped IRQ timer */
+};
+
+struct xpc_partition_uv {
+	/* >>> code is coming */
+};
+
 struct xpc_partition {
 
 	/* XPC HB infrastructure */
@@ -474,22 +515,15 @@
 	u8 remote_rp_version;	/* version# of partition's rsvd pg */
 	unsigned long remote_rp_stamp; /* time when rsvd pg was initialized */
 	u64 remote_rp_pa;	/* phys addr of partition's rsvd pg */
-	u64 remote_vars_pa;	/* phys addr of partition's vars */
-	u64 remote_vars_part_pa;	/* phys addr of partition's vars part */
 	u64 last_heartbeat;	/* HB at last read */
-	u64 remote_amos_page_pa;	/* phys addr of partition's amos page */
-	int remote_act_nasid;	/* active part's act/deact nasid */
-	int remote_act_phys_cpuid;	/* active part's act/deact phys cpuid */
 	u32 activate_IRQ_rcvd;	/* IRQs since activation */
 	spinlock_t act_lock;	/* protect updating of act_state */
 	u8 act_state;		/* from XPC HB viewpoint */
-	u8 remote_vars_version;	/* version# of partition's vars */
 	enum xp_retval reason;	/* reason partition is deactivating */
 	int reason_line;	/* line# deactivation initiated from */
-	int reactivate_nasid;	/* nasid in partition to reactivate */
 
-	unsigned long disengage_request_timeout;	/* timeout in jiffies */
-	struct timer_list disengage_request_timer;
+	unsigned long disengage_timeout;	/* timeout in jiffies */
+	struct timer_list disengage_timer;
 
 	/* XPC infrastructure referencing and teardown control */
 
@@ -502,14 +536,6 @@
 	atomic_t nchannels_engaged;  /* #of channels engaged with remote part */
 	struct xpc_channel *channels;	/* array of channel structures */
 
-	void *local_GPs_base;	/* base address of kmalloc'd space */
-	struct xpc_gp *local_GPs;	/* local Get/Put values */
-	void *remote_GPs_base;	/* base address of kmalloc'd space */
-	struct xpc_gp *remote_GPs;	/* copy of remote partition's local */
-					/* Get/Put values */
-	u64 remote_GPs_pa;	/* phys address of remote partition's local */
-				/* Get/Put values */
-
 	/* fields used to pass args when opening or closing a channel */
 
 	void *local_openclose_args_base;   /* base address of kmalloc'd space */
@@ -517,19 +543,10 @@
 	void *remote_openclose_args_base;  /* base address of kmalloc'd space */
 	struct xpc_openclose_args *remote_openclose_args; /* copy of remote's */
 							  /* args */
-	u64 remote_openclose_args_pa;	/* phys addr of remote's args */
 
 	/* IPI sending, receiving and handling related fields */
 
-	int remote_IPI_nasid;	/* nasid of where to send IPIs */
-	int remote_IPI_phys_cpuid;	/* phys CPU ID of where to send IPIs */
-	AMO_t *remote_IPI_amo_va;    /* address of remote IPI AMO_t structure */
-
-	AMO_t *local_IPI_amo_va;	/* address of IPI AMO_t structure */
 	u64 local_IPI_amo;	/* IPI amo flags yet to be handled */
-	char IPI_owner[8];	/* IPI owner's name */
-	struct timer_list dropped_IPI_timer;	/* dropped IPI timer */
-
 	spinlock_t IPI_lock;	/* IPI handler lock */
 
 	/* channel manager related fields */
@@ -537,6 +554,11 @@
 	atomic_t channel_mgr_requests;	/* #of requests to activate chan mgr */
 	wait_queue_head_t channel_mgr_wq;	/* channel mgr's wait queue */
 
+	union {
+		struct xpc_partition_sn2 sn2;
+		struct xpc_partition_uv uv;
+	} sn;
+
 } ____cacheline_aligned;
 
 /* struct xpc_partition act_state values (for XPC HB) */
@@ -565,10 +587,10 @@
 #define XPC_P_DROPPED_IPI_WAIT_INTERVAL	(0.25 * HZ)
 
 /* number of seconds to wait for other partitions to disengage */
-#define XPC_DISENGAGE_REQUEST_DEFAULT_TIMELIMIT	90
+#define XPC_DISENGAGE_DEFAULT_TIMELIMIT		90
 
-/* interval in seconds to print 'waiting disengagement' messages */
-#define XPC_DISENGAGE_PRINTMSG_INTERVAL		10
+/* interval in seconds to print 'waiting deactivation' messages */
+#define XPC_DEACTIVATE_PRINTMSG_INTERVAL	10
 
 #define XPC_PARTID(_p)	((short)((_p) - &xpc_partitions[0]))
 
@@ -578,13 +600,11 @@
 /* found in xpc_main.c */
 extern struct device *xpc_part;
 extern struct device *xpc_chan;
-extern int xpc_disengage_request_timelimit;
-extern int xpc_disengage_request_timedout;
+extern int xpc_disengage_timelimit;
+extern int xpc_disengage_timedout;
 extern atomic_t xpc_activate_IRQ_rcvd;
 extern wait_queue_head_t xpc_activate_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 *);
 extern void xpc_activate_kthreads(struct xpc_channel *, int);
 extern void xpc_create_kthreads(struct xpc_channel *, int, int);
@@ -598,31 +618,34 @@
 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 void (*xpc_notify_senders_of_disconnect) (struct xpc_channel *);
+extern void (*xpc_process_msg_IPI) (struct xpc_partition *, int);
+extern int (*xpc_n_of_deliverable_msgs) (struct xpc_channel *);
 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_request_partition_activation) (struct xpc_rsvd_page *, u64,
+						 int);
+extern void (*xpc_request_partition_reactivation) (struct xpc_partition *);
+extern void (*xpc_request_partition_deactivation) (struct xpc_partition *);
+extern void (*xpc_cancel_partition_deactivation_request) (
+							struct xpc_partition *);
 extern void (*xpc_process_activate_IRQ_rcvd) (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_indicate_partition_engaged) (struct xpc_partition *);
+extern int (*xpc_partition_engaged) (short);
+extern int (*xpc_any_partition_engaged) (void);
+extern void (*xpc_indicate_partition_disengaged) (struct xpc_partition *);
+extern void (*xpc_assume_partition_disengaged) (short);
 
-extern void (*xpc_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 void (*xpc_send_channel_closerequest) (struct xpc_channel *,
+					      unsigned long *);
+extern void (*xpc_send_channel_closereply) (struct xpc_channel *,
+					    unsigned long *);
+extern void (*xpc_send_channel_openrequest) (struct xpc_channel *,
+					     unsigned long *);
+extern void (*xpc_send_channel_openreply) (struct xpc_channel *,
+					   unsigned long *);
 
 extern enum xp_retval (*xpc_send_msg) (struct xpc_channel *, u32, void *, u16,
 				       u8, xpc_notify_func, void *);
@@ -646,8 +669,6 @@
 extern void *xpc_remote_copy_buffer_base;
 extern void *xpc_kmalloc_cacheline_aligned(size_t, gfp_t, void **);
 extern struct xpc_rsvd_page *xpc_setup_rsvd_page(void);
-extern void xpc_allow_IPI_ops(void);
-extern void xpc_restrict_IPI_ops(void);
 extern int xpc_identify_activate_IRQ_sender(void);
 extern int xpc_partition_disengaged(struct xpc_partition *);
 extern enum xp_retval xpc_mark_partition_active(struct xpc_partition *);
diff --git a/drivers/misc/sgi-xp/xpc_channel.c b/drivers/misc/sgi-xp/xpc_channel.c
index 55182c8..48b1613 100644
--- a/drivers/misc/sgi-xp/xpc_channel.c
+++ b/drivers/misc/sgi-xp/xpc_channel.c
@@ -201,7 +201,7 @@
 
 	if (!(ch->flags & XPC_C_OPENREPLY)) {
 		ch->flags |= XPC_C_OPENREPLY;
-		xpc_IPI_send_openreply(ch, irq_flags);
+		xpc_send_channel_openreply(ch, irq_flags);
 	}
 
 	if (!(ch->flags & XPC_C_ROPENREPLY))
@@ -220,52 +220,6 @@
 }
 
 /*
- * Notify those who wanted to be notified upon delivery of their message.
- */
-static void
-xpc_notify_senders(struct xpc_channel *ch, enum xp_retval reason, s64 put)
-{
-	struct xpc_notify *notify;
-	u8 notify_type;
-	s64 get = ch->w_remote_GP.get - 1;
-
-	while (++get < put && atomic_read(&ch->n_to_notify) > 0) {
-
-		notify = &ch->notify_queue[get % ch->local_nentries];
-
-		/*
-		 * See if the notify entry indicates it was associated with
-		 * a message who's sender wants to be notified. It is possible
-		 * that it is, but someone else is doing or has done the
-		 * notification.
-		 */
-		notify_type = notify->type;
-		if (notify_type == 0 ||
-		    cmpxchg(&notify->type, notify_type, 0) != notify_type) {
-			continue;
-		}
-
-		DBUG_ON(notify_type != XPC_N_CALL);
-
-		atomic_dec(&ch->n_to_notify);
-
-		if (notify->func != NULL) {
-			dev_dbg(xpc_chan, "notify->func() called, notify=0x%p, "
-				"msg_number=%ld, partid=%d, channel=%d\n",
-				(void *)notify, get, ch->partid, ch->number);
-
-			notify->func(reason, ch->partid, ch->number,
-				     notify->key);
-
-			dev_dbg(xpc_chan, "notify->func() returned, "
-				"notify=0x%p, msg_number=%ld, partid=%d, "
-				"channel=%d\n", (void *)notify, get,
-				ch->partid, ch->number);
-		}
-	}
-}
-
-/*
  * Free up message queues and other stuff that were allocated for the specified
  * channel.
  *
@@ -275,6 +229,8 @@
 static void
 xpc_free_msgqueues(struct xpc_channel *ch)
 {
+	struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
+
 	DBUG_ON(!spin_is_locked(&ch->lock));
 	DBUG_ON(atomic_read(&ch->n_to_notify) != 0);
 
@@ -287,15 +243,15 @@
 	ch->kthreads_assigned_limit = 0;
 	ch->kthreads_idle_limit = 0;
 
-	ch->local_GP->get = 0;
-	ch->local_GP->put = 0;
-	ch->remote_GP.get = 0;
-	ch->remote_GP.put = 0;
-	ch->w_local_GP.get = 0;
-	ch->w_local_GP.put = 0;
-	ch->w_remote_GP.get = 0;
-	ch->w_remote_GP.put = 0;
-	ch->next_msg_to_pull = 0;
+	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) {
 		ch->flags &= ~XPC_C_SETUP;
@@ -339,7 +295,7 @@
 
 	if (part->act_state == XPC_P_DEACTIVATING) {
 		/* can't proceed until the other side disengages from us */
-		if (xpc_partition_engaged(1UL << ch->partid))
+		if (xpc_partition_engaged(ch->partid))
 			return;
 
 	} else {
@@ -351,7 +307,7 @@
 
 		if (!(ch->flags & XPC_C_CLOSEREPLY)) {
 			ch->flags |= XPC_C_CLOSEREPLY;
-			xpc_IPI_send_closereply(ch, irq_flags);
+			xpc_send_channel_closereply(ch, irq_flags);
 		}
 
 		if (!(ch->flags & XPC_C_RCLOSEREPLY))
@@ -361,7 +317,7 @@
 	/* wake those waiting for notify completion */
 	if (atomic_read(&ch->n_to_notify) > 0) {
 		/* >>> we do callout while holding ch->lock */
-		xpc_notify_senders(ch, ch->reason, ch->w_local_GP.put);
+		xpc_notify_senders_of_disconnect(ch);
 	}
 
 	/* both sides are disconnected now */
@@ -734,7 +690,7 @@
 	/* initiate the connection */
 
 	ch->flags |= (XPC_C_OPENREQUEST | XPC_C_CONNECTING);
-	xpc_IPI_send_openrequest(ch, &irq_flags);
+	xpc_send_channel_openrequest(ch, &irq_flags);
 
 	xpc_process_connect(ch, &irq_flags);
 
@@ -743,142 +699,6 @@
 	return xpSuccess;
 }
 
-/*
- * Clear some of the msg flags in the local message queue.
- */
-static inline void
-xpc_clear_local_msgqueue_flags(struct xpc_channel *ch)
-{
-	struct xpc_msg *msg;
-	s64 get;
-
-	get = ch->w_remote_GP.get;
-	do {
-		msg = (struct xpc_msg *)((u64)ch->local_msgqueue +
-					 (get % ch->local_nentries) *
-					 ch->msg_size);
-		msg->flags = 0;
-	} while (++get < ch->remote_GP.get);
-}
-
-/*
- * Clear some of the msg flags in the remote message queue.
- */
-static inline void
-xpc_clear_remote_msgqueue_flags(struct xpc_channel *ch)
-{
-	struct xpc_msg *msg;
-	s64 put;
-
-	put = ch->w_remote_GP.put;
-	do {
-		msg = (struct xpc_msg *)((u64)ch->remote_msgqueue +
-					 (put % ch->remote_nentries) *
-					 ch->msg_size);
-		msg->flags = 0;
-	} while (++put < ch->remote_GP.put);
-}
-
-static void
-xpc_process_msg_IPI(struct xpc_partition *part, int ch_number)
-{
-	struct xpc_channel *ch = &part->channels[ch_number];
-	int nmsgs_sent;
-
-	ch->remote_GP = part->remote_GPs[ch_number];
-
-	/* See what, if anything, has changed for each connected channel */
-
-	xpc_msgqueue_ref(ch);
-
-	if (ch->w_remote_GP.get == ch->remote_GP.get &&
-	    ch->w_remote_GP.put == ch->remote_GP.put) {
-		/* nothing changed since GPs were last pulled */
-		xpc_msgqueue_deref(ch);
-		return;
-	}
-
-	if (!(ch->flags & XPC_C_CONNECTED)) {
-		xpc_msgqueue_deref(ch);
-		return;
-	}
-
-	/*
-	 * First check to see if messages recently sent by us have been
-	 * received by the other side. (The remote GET value will have
-	 * changed since we last looked at it.)
-	 */
-
-	if (ch->w_remote_GP.get != ch->remote_GP.get) {
-
-		/*
-		 * We need to notify any senders that want to be notified
-		 * that their sent messages have been received by their
-		 * intended recipients. We need to do this before updating
-		 * w_remote_GP.get so that we don't allocate the same message
-		 * queue entries prematurely (see xpc_allocate_msg()).
-		 */
-		if (atomic_read(&ch->n_to_notify) > 0) {
-			/*
-			 * Notify senders that messages sent have been
-			 * received and delivered by the other side.
-			 */
-			xpc_notify_senders(ch, xpMsgDelivered,
-					   ch->remote_GP.get);
-		}
-
-		/*
-		 * Clear msg->flags in previously sent messages, so that
-		 * they're ready for xpc_allocate_msg().
-		 */
-		xpc_clear_local_msgqueue_flags(ch);
-
-		ch->w_remote_GP.get = ch->remote_GP.get;
-
-		dev_dbg(xpc_chan, "w_remote_GP.get changed to %ld, partid=%d, "
-			"channel=%d\n", ch->w_remote_GP.get, ch->partid,
-			ch->number);
-
-		/*
-		 * If anyone was waiting for message queue entries to become
-		 * available, wake them up.
-		 */
-		if (atomic_read(&ch->n_on_msg_allocate_wq) > 0)
-			wake_up(&ch->msg_allocate_wq);
-	}
-
-	/*
-	 * Now check for newly sent messages by the other side. (The remote
-	 * PUT value will have changed since we last looked at it.)
-	 */
-
-	if (ch->w_remote_GP.put != ch->remote_GP.put) {
-		/*
-		 * Clear msg->flags in previously received messages, so that
-		 * they're ready for xpc_get_deliverable_msg().
-		 */
-		xpc_clear_remote_msgqueue_flags(ch);
-
-		ch->w_remote_GP.put = ch->remote_GP.put;
-
-		dev_dbg(xpc_chan, "w_remote_GP.put changed to %ld, partid=%d, "
-			"channel=%d\n", ch->w_remote_GP.put, ch->partid,
-			ch->number);
-
-		nmsgs_sent = ch->w_remote_GP.put - ch->w_local_GP.get;
-		if (nmsgs_sent > 0) {
-			dev_dbg(xpc_chan, "msgs waiting to be copied and "
-				"delivered=%d, partid=%d, channel=%d\n",
-				nmsgs_sent, ch->partid, ch->number);
-
-			if (ch->flags & XPC_C_CONNECTEDCALLOUT_MADE)
-				xpc_activate_kthreads(ch, nmsgs_sent);
-		}
-	}
-
-	xpc_msgqueue_deref(ch);
-}
-
 void
 xpc_process_channel_activity(struct xpc_partition *part)
 {
@@ -1117,7 +937,7 @@
 		       XPC_C_ROPENREQUEST | XPC_C_ROPENREPLY |
 		       XPC_C_CONNECTING | XPC_C_CONNECTED);
 
-	xpc_IPI_send_closerequest(ch, irq_flags);
+	xpc_send_channel_closerequest(ch, irq_flags);
 
 	if (channel_was_connected)
 		ch->flags |= XPC_C_WASCONNECTED;
diff --git a/drivers/misc/sgi-xp/xpc_main.c b/drivers/misc/sgi-xp/xpc_main.c
index 8780d5d..563aaf4 100644
--- a/drivers/misc/sgi-xp/xpc_main.c
+++ b/drivers/misc/sgi-xp/xpc_main.c
@@ -26,7 +26,7 @@
  *	Caveats:
  *
  *	  . We currently have no way to determine which nasid an IPI came
- *	    from. Thus, xpc_IPI_send() does a remote AMO write followed by
+ *	    from. Thus, >>> xpc_IPI_send() does a remote AMO write followed by
  *	    an IPI. The AMO indicates where data is to be pulled from, so
  *	    after the IPI arrives, the remote partition checks the AMO word.
  *	    The IPI can actually arrive before the AMO however, so other code
@@ -89,9 +89,9 @@
 static int xpc_hb_check_min_interval = 10;
 static int xpc_hb_check_max_interval = 120;
 
-int xpc_disengage_request_timelimit = XPC_DISENGAGE_REQUEST_DEFAULT_TIMELIMIT;
-static int xpc_disengage_request_min_timelimit;	/* = 0 */
-static int xpc_disengage_request_max_timelimit = 120;
+int xpc_disengage_timelimit = XPC_DISENGAGE_DEFAULT_TIMELIMIT;
+static int xpc_disengage_min_timelimit;	/* = 0 */
+static int xpc_disengage_max_timelimit = 120;
 
 static ctl_table xpc_sys_xpc_hb_dir[] = {
 	{
@@ -124,14 +124,14 @@
 	 .child = xpc_sys_xpc_hb_dir},
 	{
 	 .ctl_name = CTL_UNNUMBERED,
-	 .procname = "disengage_request_timelimit",
-	 .data = &xpc_disengage_request_timelimit,
+	 .procname = "disengage_timelimit",
+	 .data = &xpc_disengage_timelimit,
 	 .maxlen = sizeof(int),
 	 .mode = 0644,
 	 .proc_handler = &proc_dointvec_minmax,
 	 .strategy = &sysctl_intvec,
-	 .extra1 = &xpc_disengage_request_min_timelimit,
-	 .extra2 = &xpc_disengage_request_max_timelimit},
+	 .extra1 = &xpc_disengage_min_timelimit,
+	 .extra2 = &xpc_disengage_max_timelimit},
 	{}
 };
 static ctl_table xpc_sys_dir[] = {
@@ -144,8 +144,8 @@
 };
 static struct ctl_table_header *xpc_sysctl;
 
-/* non-zero if any remote partition disengage request was timed out */
-int xpc_disengage_request_timedout;
+/* non-zero if any remote partition disengage was timed out */
+int xpc_disengage_timedout;
 
 /* #of activate IRQs received */
 atomic_t xpc_activate_IRQ_rcvd = ATOMIC_INIT(0);
@@ -184,38 +184,36 @@
 void (*xpc_check_remote_hb) (void);
 
 enum xp_retval (*xpc_make_first_contact) (struct xpc_partition *part);
+void (*xpc_notify_senders_of_disconnect) (struct xpc_channel *ch);
 u64 (*xpc_get_IPI_flags) (struct xpc_partition *part);
+void (*xpc_process_msg_IPI) (struct xpc_partition *part, int ch_number);
+int (*xpc_n_of_deliverable_msgs) (struct xpc_channel *ch);
 struct xpc_msg *(*xpc_get_deliverable_msg) (struct xpc_channel *ch);
 
-void (*xpc_initiate_partition_activation) (struct xpc_rsvd_page *remote_rp,
-					   u64 remote_rp_pa, int nasid);
+void (*xpc_request_partition_activation) (struct xpc_rsvd_page *remote_rp,
+					  u64 remote_rp_pa, int nasid);
+void (*xpc_request_partition_reactivation) (struct xpc_partition *part);
+void (*xpc_request_partition_deactivation) (struct xpc_partition *part);
+void (*xpc_cancel_partition_deactivation_request) (struct xpc_partition *part);
 
 void (*xpc_process_activate_IRQ_rcvd) (int n_IRQs_expected);
 enum xp_retval (*xpc_setup_infrastructure) (struct xpc_partition *part);
 void (*xpc_teardown_infrastructure) (struct xpc_partition *part);
 
-void (*xpc_mark_partition_engaged) (struct xpc_partition *part);
-void (*xpc_mark_partition_disengaged) (struct xpc_partition *part);
-void (*xpc_request_partition_disengage) (struct xpc_partition *part);
-void (*xpc_cancel_partition_disengage_request) (struct xpc_partition *part);
-u64 (*xpc_partition_engaged) (u64 partid_mask);
-u64 (*xpc_partition_disengage_requested) (u64 partid_mask);
-void (*xpc_clear_partition_engaged) (u64 partid_mask);
-void (*xpc_clear_partition_disengage_request) (u64 partid_mask);
+void (*xpc_indicate_partition_engaged) (struct xpc_partition *part);
+int (*xpc_partition_engaged) (short partid);
+int (*xpc_any_partition_engaged) (void);
+void (*xpc_indicate_partition_disengaged) (struct xpc_partition *part);
+void (*xpc_assume_partition_disengaged) (short partid);
 
-void (*xpc_IPI_send_local_activate) (int from_nasid);
-void (*xpc_IPI_send_activated) (struct xpc_partition *part);
-void (*xpc_IPI_send_local_reactivate) (int from_nasid);
-void (*xpc_IPI_send_disengage) (struct xpc_partition *part);
-
-void (*xpc_IPI_send_closerequest) (struct xpc_channel *ch,
-				   unsigned long *irq_flags);
-void (*xpc_IPI_send_closereply) (struct xpc_channel *ch,
-				 unsigned long *irq_flags);
-void (*xpc_IPI_send_openrequest) (struct xpc_channel *ch,
-				  unsigned long *irq_flags);
-void (*xpc_IPI_send_openreply) (struct xpc_channel *ch,
-				unsigned long *irq_flags);
+void (*xpc_send_channel_closerequest) (struct xpc_channel *ch,
+				       unsigned long *irq_flags);
+void (*xpc_send_channel_closereply) (struct xpc_channel *ch,
+				     unsigned long *irq_flags);
+void (*xpc_send_channel_openrequest) (struct xpc_channel *ch,
+				      unsigned long *irq_flags);
+void (*xpc_send_channel_openreply) (struct xpc_channel *ch,
+				    unsigned long *irq_flags);
 
 enum xp_retval (*xpc_send_msg) (struct xpc_channel *ch, u32 flags,
 				void *payload, u16 payload_size, u8 notify_type,
@@ -223,19 +221,19 @@
 void (*xpc_received_msg) (struct xpc_channel *ch, struct xpc_msg *msg);
 
 /*
- * Timer function to enforce the timelimit on the partition disengage request.
+ * Timer function to enforce the timelimit on the partition disengage.
  */
 static void
-xpc_timeout_partition_disengage_request(unsigned long data)
+xpc_timeout_partition_disengage(unsigned long data)
 {
 	struct xpc_partition *part = (struct xpc_partition *)data;
 
-	DBUG_ON(time_is_after_jiffies(part->disengage_request_timeout));
+	DBUG_ON(time_is_after_jiffies(part->disengage_timeout));
 
 	(void)xpc_partition_disengaged(part);
 
-	DBUG_ON(part->disengage_request_timeout != 0);
-	DBUG_ON(xpc_partition_engaged(1UL << XPC_PARTID(part)) != 0);
+	DBUG_ON(part->disengage_timeout != 0);
+	DBUG_ON(xpc_partition_engaged(XPC_PARTID(part)));
 }
 
 /*
@@ -464,7 +462,7 @@
 
 	if (part->reason == xpReactivating) {
 		/* interrupting ourselves results in activating partition */
-		xpc_IPI_send_local_reactivate(part->reactivate_nasid);
+		xpc_request_partition_reactivation(part);
 	}
 
 	return 0;
@@ -496,82 +494,6 @@
 	}
 }
 
-/*
- * Check to see if there is any channel activity to/from the specified
- * partition.
- */
-static void
-xpc_check_for_channel_activity(struct xpc_partition *part)
-{
-	u64 IPI_amo;
-	unsigned long irq_flags;
-
-/* this needs to be uncommented, but I'm thinking this function and the */
-/* ones that call it need to be moved into xpc_sn2.c... */
-	IPI_amo = 0; /* = 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);
-}
-
-/*
- * Handle the receipt of a SGI_XPC_NOTIFY IRQ by seeing whether the specified
- * partition actually sent it. Since SGI_XPC_NOTIFY IRQs may be shared by more
- * than one partition, we use an AMO_t structure per partition to indicate
- * whether a partition has sent an IPI or not.  If it has, then wake up the
- * associated kthread to handle it.
- *
- * All SGI_XPC_NOTIFY IRQs received by XPC are the result of IPIs sent by XPC
- * running on other partitions.
- *
- * Noteworthy Arguments:
- *
- *	irq - Interrupt ReQuest number. NOT USED.
- *
- *	dev_id - partid of IPI's potential sender.
- */
-irqreturn_t
-xpc_notify_IRQ_handler(int irq, void *dev_id)
-{
-	short partid = (short)(u64)dev_id;
-	struct xpc_partition *part = &xpc_partitions[partid];
-
-	DBUG_ON(partid < 0 || partid >= xp_max_npartitions);
-
-	if (xpc_part_ref(part)) {
-		xpc_check_for_channel_activity(part);
-
-		xpc_part_deref(part);
-	}
-	return IRQ_HANDLED;
-}
-
-/*
- * Check to see if xpc_notify_IRQ_handler() dropped any IPIs on the floor
- * because the write to their associated IPI amo completed after the IRQ/IPI
- * was received.
- */
-void
-xpc_dropped_IPI_check(struct xpc_partition *part)
-{
-	if (xpc_part_ref(part)) {
-		xpc_check_for_channel_activity(part);
-
-		part->dropped_IPI_timer.expires = jiffies +
-		    XPC_P_DROPPED_IPI_WAIT_INTERVAL;
-		add_timer(&part->dropped_IPI_timer);
-		xpc_part_deref(part);
-	}
-}
-
 void
 xpc_activate_kthreads(struct xpc_channel *ch, int needed)
 {
@@ -616,7 +538,7 @@
 	do {
 		/* deliver messages to their intended recipients */
 
-		while (ch->w_local_GP.get < ch->w_remote_GP.put &&
+		while (xpc_n_of_deliverable_msgs(ch) > 0 &&
 		       !(ch->flags & XPC_C_DISCONNECTING)) {
 			xpc_deliver_msg(ch);
 		}
@@ -632,7 +554,7 @@
 			"wait_event_interruptible_exclusive()\n");
 
 		(void)wait_event_interruptible_exclusive(ch->idle_wq,
-				(ch->w_local_GP.get < ch->w_remote_GP.put ||
+				(xpc_n_of_deliverable_msgs(ch) > 0 ||
 				 (ch->flags & XPC_C_DISCONNECTING)));
 
 		atomic_dec(&ch->kthreads_idle);
@@ -677,7 +599,7 @@
 			 * additional kthreads to help deliver them. We only
 			 * need one less than total #of messages to deliver.
 			 */
-			n_needed = ch->w_remote_GP.put - ch->w_local_GP.get - 1;
+			n_needed = xpc_n_of_deliverable_msgs(ch) - 1;
 			if (n_needed > 0 && !(ch->flags & XPC_C_DISCONNECTING))
 				xpc_activate_kthreads(ch, n_needed);
 
@@ -703,11 +625,9 @@
 	}
 	spin_unlock_irqrestore(&ch->lock, irq_flags);
 
-	if (atomic_dec_return(&ch->kthreads_assigned) == 0) {
-		if (atomic_dec_return(&part->nchannels_engaged) == 0) {
-			xpc_mark_partition_disengaged(part);
-			xpc_IPI_send_disengage(part);
-		}
+	if (atomic_dec_return(&ch->kthreads_assigned) == 0 &&
+	    atomic_dec_return(&part->nchannels_engaged) == 0) {
+		xpc_indicate_partition_disengaged(part);
 	}
 
 	xpc_msgqueue_deref(ch);
@@ -758,9 +678,9 @@
 		} else if (ch->flags & XPC_C_DISCONNECTING) {
 			break;
 
-		} else if (atomic_inc_return(&ch->kthreads_assigned) == 1) {
-			if (atomic_inc_return(&part->nchannels_engaged) == 1)
-				xpc_mark_partition_engaged(part);
+		} else if (atomic_inc_return(&ch->kthreads_assigned) == 1 &&
+			   atomic_inc_return(&part->nchannels_engaged) == 1) {
+				xpc_indicate_partition_engaged(part);
 		}
 		(void)xpc_part_ref(part);
 		xpc_msgqueue_ref(ch);
@@ -782,8 +702,7 @@
 
 			if (atomic_dec_return(&ch->kthreads_assigned) == 0 &&
 			    atomic_dec_return(&part->nchannels_engaged) == 0) {
-				xpc_mark_partition_disengaged(part);
-				xpc_IPI_send_disengage(part);
+				xpc_indicate_partition_disengaged(part);
 			}
 			xpc_msgqueue_deref(ch);
 			xpc_part_deref(part);
@@ -862,7 +781,7 @@
 	short partid;
 	int active_part_count, printed_waiting_msg = 0;
 	struct xpc_partition *part;
-	unsigned long printmsg_time, disengage_request_timeout = 0;
+	unsigned long printmsg_time, disengage_timeout = 0;
 
 	/* a 'rmmod XPC' and a 'reboot' cannot both end up here together */
 	DBUG_ON(xpc_exiting == 1);
@@ -886,8 +805,8 @@
 
 	/* wait for all partitions to become inactive */
 
-	printmsg_time = jiffies + (XPC_DISENGAGE_PRINTMSG_INTERVAL * HZ);
-	xpc_disengage_request_timedout = 0;
+	printmsg_time = jiffies + (XPC_DEACTIVATE_PRINTMSG_INTERVAL * HZ);
+	xpc_disengage_timedout = 0;
 
 	do {
 		active_part_count = 0;
@@ -904,36 +823,32 @@
 
 			XPC_DEACTIVATE_PARTITION(part, reason);
 
-			if (part->disengage_request_timeout >
-			    disengage_request_timeout) {
-				disengage_request_timeout =
-				    part->disengage_request_timeout;
-			}
+			if (part->disengage_timeout > disengage_timeout)
+				disengage_timeout = part->disengage_timeout;
 		}
 
-		if (xpc_partition_engaged(-1UL)) {
+		if (xpc_any_partition_engaged()) {
 			if (time_is_before_jiffies(printmsg_time)) {
 				dev_info(xpc_part, "waiting for remote "
-					 "partitions to disengage, timeout in "
-					 "%ld seconds\n",
-					 (disengage_request_timeout - jiffies)
-					 / HZ);
+					 "partitions to deactivate, timeout in "
+					 "%ld seconds\n", (disengage_timeout -
+					 jiffies) / HZ);
 				printmsg_time = jiffies +
-				    (XPC_DISENGAGE_PRINTMSG_INTERVAL * HZ);
+				    (XPC_DEACTIVATE_PRINTMSG_INTERVAL * HZ);
 				printed_waiting_msg = 1;
 			}
 
 		} else if (active_part_count > 0) {
 			if (printed_waiting_msg) {
 				dev_info(xpc_part, "waiting for local partition"
-					 " to disengage\n");
+					 " to deactivate\n");
 				printed_waiting_msg = 0;
 			}
 
 		} else {
-			if (!xpc_disengage_request_timedout) {
+			if (!xpc_disengage_timedout) {
 				dev_info(xpc_part, "all partitions have "
-					 "disengaged\n");
+					 "deactivated\n");
 			}
 			break;
 		}
@@ -943,7 +858,7 @@
 
 	} while (1);
 
-	DBUG_ON(xpc_partition_engaged(-1UL));
+	DBUG_ON(xpc_any_partition_engaged());
 	DBUG_ON(xpc_any_hbs_allowed() != 0);
 
 	/* indicate to others that our reserved page is uninitialized */
@@ -996,15 +911,16 @@
 }
 
 /*
- * Notify other partitions to disengage from all references to our memory.
+ * Notify other partitions to deactivate from us by first disengaging from all
+ * references to our memory.
  */
 static void
-xpc_die_disengage(void)
+xpc_die_deactivate(void)
 {
 	struct xpc_partition *part;
 	short partid;
-	unsigned long engaged;
-	long time, printmsg_time, disengage_request_timeout;
+	int any_engaged;
+	long time, printmsg_time, disengage_timeout;
 
 	/* keep xpc_hb_checker thread from doing anything (just in case) */
 	xpc_exiting = 1;
@@ -1014,43 +930,37 @@
 	for (partid = 0; partid < xp_max_npartitions; partid++) {
 		part = &xpc_partitions[partid];
 
-		if (!XPC_SUPPORTS_DISENGAGE_REQUEST(part->
-		    remote_vars_version)) {
-
-			/* just in case it was left set by an earlier XPC */
-			xpc_clear_partition_engaged(1UL << partid);
-			continue;
-		}
-
-		if (xpc_partition_engaged(1UL << partid) ||
+		if (xpc_partition_engaged(partid) ||
 		    part->act_state != XPC_P_INACTIVE) {
-			xpc_request_partition_disengage(part);
-			xpc_mark_partition_disengaged(part);
-			xpc_IPI_send_disengage(part);
+			xpc_request_partition_deactivation(part);
+			xpc_indicate_partition_disengaged(part);
 		}
 	}
 
 	time = rtc_time();
 	printmsg_time = time +
-	    (XPC_DISENGAGE_PRINTMSG_INTERVAL * sn_rtc_cycles_per_second);
-	disengage_request_timeout = time +
-	    (xpc_disengage_request_timelimit * sn_rtc_cycles_per_second);
+	    (XPC_DEACTIVATE_PRINTMSG_INTERVAL * sn_rtc_cycles_per_second);
+	disengage_timeout = time +
+	    (xpc_disengage_timelimit * sn_rtc_cycles_per_second);
 
-	/* wait for all other partitions to disengage from us */
+	/*
+	 * Though we requested that all other partitions deactivate from us,
+	 * we only wait until they've all disengaged.
+	 */
 
 	while (1) {
-		engaged = xpc_partition_engaged(-1UL);
-		if (!engaged) {
-			dev_info(xpc_part, "all partitions have disengaged\n");
+		any_engaged = xpc_any_partition_engaged();
+		if (!any_engaged) {
+			dev_info(xpc_part, "all partitions have deactivated\n");
 			break;
 		}
 
 		time = rtc_time();
-		if (time >= disengage_request_timeout) {
+		if (time >= disengage_timeout) {
 			for (partid = 0; partid < xp_max_npartitions;
 			     partid++) {
-				if (engaged & (1UL << partid)) {
-					dev_info(xpc_part, "disengage from "
+				if (xpc_partition_engaged(partid)) {
+					dev_info(xpc_part, "deactivate from "
 						 "remote partition %d timed "
 						 "out\n", partid);
 				}
@@ -1060,11 +970,11 @@
 
 		if (time >= printmsg_time) {
 			dev_info(xpc_part, "waiting for remote partitions to "
-				 "disengage, timeout in %ld seconds\n",
-				 (disengage_request_timeout - time) /
+				 "deactivate, timeout in %ld seconds\n",
+				 (disengage_timeout - time) /
 				 sn_rtc_cycles_per_second);
 			printmsg_time = time +
-			    (XPC_DISENGAGE_PRINTMSG_INTERVAL *
+			    (XPC_DEACTIVATE_PRINTMSG_INTERVAL *
 			     sn_rtc_cycles_per_second);
 		}
 	}
@@ -1084,7 +994,7 @@
 	switch (event) {
 	case DIE_MACHINE_RESTART:
 	case DIE_MACHINE_HALT:
-		xpc_die_disengage();
+		xpc_die_deactivate();
 		break;
 
 	case DIE_KDEBUG_ENTER:
@@ -1183,10 +1093,10 @@
 		part->act_state = XPC_P_INACTIVE;
 		XPC_SET_REASON(part, 0, 0);
 
-		init_timer(&part->disengage_request_timer);
-		part->disengage_request_timer.function =
-		    xpc_timeout_partition_disengage_request;
-		part->disengage_request_timer.data = (unsigned long)part;
+		init_timer(&part->disengage_timer);
+		part->disengage_timer.function =
+		    xpc_timeout_partition_disengage;
+		part->disengage_timer.data = (unsigned long)part;
 
 		part->setup_state = XPC_P_UNSET;
 		init_waitqueue_head(&part->teardown_wq);
@@ -1295,9 +1205,9 @@
 MODULE_PARM_DESC(xpc_hb_check_interval, "Number of seconds between "
 		 "heartbeat checks.");
 
-module_param(xpc_disengage_request_timelimit, int, 0);
-MODULE_PARM_DESC(xpc_disengage_request_timelimit, "Number of seconds to wait "
-		 "for disengage request to complete.");
+module_param(xpc_disengage_timelimit, int, 0);
+MODULE_PARM_DESC(xpc_disengage_timelimit, "Number of seconds to wait "
+		 "for disengage to complete.");
 
 module_param(xpc_kdebug_ignore, int, 0);
 MODULE_PARM_DESC(xpc_kdebug_ignore, "Should lack of heartbeat be ignored by "
diff --git a/drivers/misc/sgi-xp/xpc_partition.c b/drivers/misc/sgi-xp/xpc_partition.c
index bf9b119..c769ab8 100644
--- a/drivers/misc/sgi-xp/xpc_partition.c
+++ b/drivers/misc/sgi-xp/xpc_partition.c
@@ -242,7 +242,7 @@
 		return xpBadVersion;
 	}
 
-	/* check that both local and remote partids are valid for each side */
+	/* check that both remote and local partids are valid for each side */
 	if (remote_rp->SAL_partid < 0 ||
 	    remote_rp->SAL_partid >= xp_max_npartitions ||
 	    remote_rp->max_npartitions <= sn_partition_id) {
@@ -256,8 +256,9 @@
 }
 
 /*
- * See if the other side has responded to a partition disengage request
- * from us.
+ * See if the other side has responded to a partition deactivate request
+ * from us. Though we requested the remote partition to deactivate with regard
+ * to us, we really only need to wait for the other side to disengage from us.
  */
 int
 xpc_partition_disengaged(struct xpc_partition *part)
@@ -265,41 +266,37 @@
 	short partid = XPC_PARTID(part);
 	int disengaged;
 
-	disengaged = (xpc_partition_engaged(1UL << partid) == 0);
-	if (part->disengage_request_timeout) {
+	disengaged = !xpc_partition_engaged(partid);
+	if (part->disengage_timeout) {
 		if (!disengaged) {
-			if (time_is_after_jiffies(part->
-						  disengage_request_timeout)) {
+			if (time_is_after_jiffies(part->disengage_timeout)) {
 				/* timelimit hasn't been reached yet */
 				return 0;
 			}
 
 			/*
-			 * Other side hasn't responded to our disengage
+			 * Other side hasn't responded to our deactivate
 			 * request in a timely fashion, so assume it's dead.
 			 */
 
-			dev_info(xpc_part, "disengage from remote partition %d "
-				 "timed out\n", partid);
-			xpc_disengage_request_timedout = 1;
-			xpc_clear_partition_engaged(1UL << partid);
+			dev_info(xpc_part, "deactivate request to remote "
+				 "partition %d timed out\n", partid);
+			xpc_disengage_timedout = 1;
+			xpc_assume_partition_disengaged(partid);
 			disengaged = 1;
 		}
-		part->disengage_request_timeout = 0;
+		part->disengage_timeout = 0;
 
 		/* cancel the timer function, provided it's not us */
-		if (!in_interrupt()) {
-			del_singleshot_timer_sync(&part->
-						  disengage_request_timer);
-		}
+		if (!in_interrupt())
+			del_singleshot_timer_sync(&part->disengage_timer);
 
 		DBUG_ON(part->act_state != XPC_P_DEACTIVATING &&
 			part->act_state != XPC_P_INACTIVE);
 		if (part->act_state != XPC_P_INACTIVE)
 			xpc_wakeup_channel_mgr(part);
 
-		if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version))
-			xpc_cancel_partition_disengage_request(part);
+		xpc_cancel_partition_deactivation_request(part);
 	}
 	return disengaged;
 }
@@ -329,7 +326,7 @@
 }
 
 /*
- * Notify XPC that the partition is down.
+ * Start the process of deactivating the specified partition.
  */
 void
 xpc_deactivate_partition(const int line, struct xpc_partition *part,
@@ -344,7 +341,7 @@
 		spin_unlock_irqrestore(&part->act_lock, irq_flags);
 		if (reason == xpReactivating) {
 			/* we interrupt ourselves to reactivate partition */
-			xpc_IPI_send_local_reactivate(part->reactivate_nasid);
+			xpc_request_partition_reactivation(part);
 		}
 		return;
 	}
@@ -362,17 +359,13 @@
 
 	spin_unlock_irqrestore(&part->act_lock, irq_flags);
 
-	if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version)) {
-		xpc_request_partition_disengage(part);
-		xpc_IPI_send_disengage(part);
+	/* ask remote partition to deactivate with regard to us */
+	xpc_request_partition_deactivation(part);
 
-		/* set a timelimit on the disengage request */
-		part->disengage_request_timeout = jiffies +
-		    (xpc_disengage_request_timelimit * HZ);
-		part->disengage_request_timer.expires =
-		    part->disengage_request_timeout;
-		add_timer(&part->disengage_request_timer);
-	}
+	/* set a timelimit on the disengage phase of the deactivation request */
+	part->disengage_timeout = jiffies + (xpc_disengage_timelimit * HZ);
+	part->disengage_timer.expires = part->disengage_timeout;
+	add_timer(&part->disengage_timer);
 
 	dev_dbg(xpc_part, "bringing partition %d down, reason = %d\n",
 		XPC_PARTID(part), reason);
@@ -505,8 +498,8 @@
 				continue;
 			}
 
-			xpc_initiate_partition_activation(remote_rp,
-							  remote_rp_pa, nasid);
+			xpc_request_partition_activation(remote_rp,
+							 remote_rp_pa, nasid);
 		}
 	}
 
diff --git a/drivers/misc/sgi-xp/xpc_sn2.c b/drivers/misc/sgi-xp/xpc_sn2.c
index 4659f6c..69d74bd 100644
--- a/drivers/misc/sgi-xp/xpc_sn2.c
+++ b/drivers/misc/sgi-xp/xpc_sn2.c
@@ -196,39 +196,87 @@
 	wake_up_interruptible(&xpc_activate_IRQ_wq);
 }
 
-static void
-xpc_IPI_send_local_activate_sn2(int from_nasid)
-{
-	xpc_activate_IRQ_send_local_sn2(from_nasid);
-}
-
-static void
-xpc_IPI_send_activated_sn2(struct xpc_partition *part)
-{
-	xpc_activate_IRQ_send_sn2(part->remote_amos_page_pa,
-				  cnodeid_to_nasid(0), part->remote_act_nasid,
-				  part->remote_act_phys_cpuid);
-}
-
-static void
-xpc_IPI_send_local_reactivate_sn2(int from_nasid)
-{
-	xpc_activate_IRQ_send_local_sn2(from_nasid);
-}
-
-static void
-xpc_IPI_send_disengage_sn2(struct xpc_partition *part)
-{
-	xpc_activate_IRQ_send_sn2(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.
  */
 
 /*
+ * Check to see if there is any channel activity to/from the specified
+ * partition.
+ */
+static void
+xpc_check_for_channel_activity_sn2(struct xpc_partition *part)
+{
+	u64 IPI_amo;
+	unsigned long irq_flags;
+
+	IPI_amo = xpc_IPI_receive_sn2(part->sn.sn2.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);
+}
+
+/*
+ * Handle the receipt of a SGI_XPC_NOTIFY IRQ by seeing whether the specified
+ * partition actually sent it. Since SGI_XPC_NOTIFY IRQs may be shared by more
+ * than one partition, we use an AMO_t structure per partition to indicate
+ * whether a partition has sent an IPI or not.  If it has, then wake up the
+ * associated kthread to handle it.
+ *
+ * All SGI_XPC_NOTIFY IRQs received by XPC are the result of IPIs sent by XPC
+ * running on other partitions.
+ *
+ * Noteworthy Arguments:
+ *
+ *	irq - Interrupt ReQuest number. NOT USED.
+ *
+ *	dev_id - partid of IPI's potential sender.
+ */
+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);
+
+	if (xpc_part_ref(part)) {
+		xpc_check_for_channel_activity_sn2(part);
+
+		xpc_part_deref(part);
+	}
+	return IRQ_HANDLED;
+}
+
+/*
+ * Check to see if xpc_handle_notify_IRQ_sn2() dropped any IPIs on the floor
+ * because the write to their associated IPI amo completed after the IRQ/IPI
+ * was received.
+ */
+static void
+xpc_dropped_notify_IRQ_check_sn2(struct xpc_partition *part)
+{
+	struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
+
+	if (xpc_part_ref(part)) {
+		xpc_check_for_channel_activity_sn2(part);
+
+		part_sn2->dropped_notify_IRQ_timer.expires = jiffies +
+		    XPC_P_DROPPED_IPI_WAIT_INTERVAL;
+		add_timer(&part_sn2->dropped_notify_IRQ_timer);
+		xpc_part_deref(part);
+	}
+}
+
+/*
  * Send an IPI to the remote partition that is associated with the
  * specified channel.
  */
@@ -237,13 +285,14 @@
 			char *ipi_flag_string, unsigned long *irq_flags)
 {
 	struct xpc_partition *part = &xpc_partitions[ch->partid];
+	struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
 	enum xp_retval ret;
 
 	if (likely(part->act_state != XPC_P_DEACTIVATING)) {
-		ret = xpc_IPI_send_sn2(part->remote_IPI_amo_va,
+		ret = xpc_IPI_send_sn2(part_sn2->remote_IPI_amo_va,
 				       (u64)ipi_flag << (ch->number * 8),
-				       part->remote_IPI_nasid,
-				       part->remote_IPI_phys_cpuid,
+				       part_sn2->remote_IPI_nasid,
+				       part_sn2->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);
@@ -263,7 +312,7 @@
 /*
  * 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().
+ * by xpc_dropped_notify_IRQ_check_sn2().
  */
 static void
 xpc_notify_IRQ_send_local_sn2(struct xpc_channel *ch, u8 ipi_flag,
@@ -271,7 +320,7 @@
 {
 	struct xpc_partition *part = &xpc_partitions[ch->partid];
 
-	FETCHOP_STORE_OP(TO_AMO((u64)&part->local_IPI_amo_va->variable),
+	FETCHOP_STORE_OP(TO_AMO((u64)&part->sn.sn2.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);
@@ -281,7 +330,8 @@
 		xpc_notify_IRQ_send_local_sn2(_ch, _ipi_f, #_ipi_f)
 
 static void
-xpc_IPI_send_closerequest_sn2(struct xpc_channel *ch, unsigned long *irq_flags)
+xpc_send_channel_closerequest_sn2(struct xpc_channel *ch,
+				  unsigned long *irq_flags)
 {
 	struct xpc_openclose_args *args = ch->local_openclose_args;
 
@@ -290,13 +340,15 @@
 }
 
 static void
-xpc_IPI_send_closereply_sn2(struct xpc_channel *ch, unsigned long *irq_flags)
+xpc_send_channel_closereply_sn2(struct xpc_channel *ch,
+				unsigned long *irq_flags)
 {
 	XPC_NOTIFY_IRQ_SEND_SN2(ch, XPC_IPI_CLOSEREPLY, irq_flags);
 }
 
 static void
-xpc_IPI_send_openrequest_sn2(struct xpc_channel *ch, unsigned long *irq_flags)
+xpc_send_channel_openrequest_sn2(struct xpc_channel *ch,
+				 unsigned long *irq_flags)
 {
 	struct xpc_openclose_args *args = ch->local_openclose_args;
 
@@ -306,7 +358,7 @@
 }
 
 static void
-xpc_IPI_send_openreply_sn2(struct xpc_channel *ch, unsigned long *irq_flags)
+xpc_send_channel_openreply_sn2(struct xpc_channel *ch, unsigned long *irq_flags)
 {
 	struct xpc_openclose_args *args = ch->local_openclose_args;
 
@@ -317,13 +369,13 @@
 }
 
 static void
-xpc_IPI_send_msgrequest_sn2(struct xpc_channel *ch)
+xpc_send_channel_msgrequest_sn2(struct xpc_channel *ch)
 {
 	XPC_NOTIFY_IRQ_SEND_SN2(ch, XPC_IPI_MSGREQUEST, NULL);
 }
 
 static void
-xpc_IPI_send_local_msgrequest_sn2(struct xpc_channel *ch)
+xpc_send_channel_local_msgrequest_sn2(struct xpc_channel *ch)
 {
 	XPC_NOTIFY_IRQ_SEND_LOCAL_SN2(ch, XPC_IPI_MSGREQUEST);
 }
@@ -334,10 +386,10 @@
  */
 
 static void
-xpc_mark_partition_engaged_sn2(struct xpc_partition *part)
+xpc_indicate_partition_engaged_sn2(struct xpc_partition *part)
 {
 	unsigned long irq_flags;
-	AMO_t *amo = (AMO_t *)__va(part->remote_amos_page_pa +
+	AMO_t *amo = (AMO_t *)__va(part->sn.sn2.remote_amos_page_pa +
 				   (XPC_ENGAGED_PARTITIONS_AMO *
 				    sizeof(AMO_t)));
 
@@ -360,10 +412,11 @@
 }
 
 static void
-xpc_mark_partition_disengaged_sn2(struct xpc_partition *part)
+xpc_indicate_partition_disengaged_sn2(struct xpc_partition *part)
 {
+	struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
 	unsigned long irq_flags;
-	AMO_t *amo = (AMO_t *)__va(part->remote_amos_page_pa +
+	AMO_t *amo = (AMO_t *)__va(part_sn2->remote_amos_page_pa +
 				   (XPC_ENGAGED_PARTITIONS_AMO *
 				    sizeof(AMO_t)));
 
@@ -383,96 +436,44 @@
 						     xp_nofault_PIOR_target));
 
 	local_irq_restore(irq_flags);
-}
 
-static void
-xpc_request_partition_disengage_sn2(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.
+	 * Send activate IRQ to get other side to see that we've cleared our
+	 * bit in their engaged partitions AMO.
 	 */
-	(void)xp_nofault_PIOR((u64 *)GLOBAL_MMR_ADDR(NASID_GET(&amo->
-							       variable),
-						     xp_nofault_PIOR_target));
-
-	local_irq_restore(irq_flags);
+	xpc_activate_IRQ_send_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_disengage_request_sn2(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 u64
-xpc_partition_engaged_sn2(u64 partid_mask)
+static int
+xpc_partition_engaged_sn2(short partid)
 {
 	AMO_t *amo = xpc_vars->amos_page + XPC_ENGAGED_PARTITIONS_AMO;
 
-	/* return our partition's AMO variable ANDed with partid_mask */
+	/* our partition's AMO variable ANDed with partid mask */
 	return (FETCHOP_LOAD_OP(TO_AMO((u64)&amo->variable), FETCHOP_LOAD) &
-		partid_mask);
+		(1UL << partid)) != 0;
 }
 
-static u64
-xpc_partition_disengage_requested_sn2(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 void
-xpc_clear_partition_engaged_sn2(u64 partid_mask)
+static int
+xpc_any_partition_engaged_sn2(void)
 {
 	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);
+	/* our partition's AMO variable */
+	return FETCHOP_LOAD_OP(TO_AMO((u64)&amo->variable), FETCHOP_LOAD) != 0;
 }
 
 static void
-xpc_clear_partition_disengage_request_sn2(u64 partid_mask)
+xpc_assume_partition_disengaged_sn2(short partid)
 {
-	AMO_t *amo = xpc_vars->amos_page + XPC_DISENGAGE_REQUEST_AMO;
+	AMO_t *amo = xpc_vars->amos_page + XPC_ENGAGED_PARTITIONS_AMO;
 
-	/* clear bit(s) based on partid_mask in our partition's 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);
+			 ~(1UL << partid));
 }
 
 /* original protection values for each node */
@@ -545,7 +546,6 @@
 	xpc_vars_part = (struct xpc_vars_part_sn2 *)((u8 *)XPC_RP_VARS(rp) +
 						     XPC_RP_VARS_SIZE);
 
-
 	/*
 	 * Before clearing xpc_vars, see if a page of AMOs had been previously
 	 * allocated. If not we'll need to allocate one and set permissions
@@ -583,8 +583,8 @@
 	memset(xpc_vars, 0, sizeof(struct xpc_vars_sn2));
 
 	xpc_vars->version = XPC_V_VERSION;
-	xpc_vars->act_nasid = cpuid_to_nasid(0);
-	xpc_vars->act_phys_cpuid = cpu_physical_id(0);
+	xpc_vars->activate_IRQ_nasid = cpuid_to_nasid(0);
+	xpc_vars->activate_IRQ_phys_cpuid = cpu_physical_id(0);
 	xpc_vars->vars_part_pa = __pa(xpc_vars_part);
 	xpc_vars->amos_page_pa = ia64_tpa((u64)amos_page);
 	xpc_vars->amos_page = amos_page;	/* save for next load of XPC */
@@ -599,7 +599,7 @@
 
 	/* initialize the engaged remote partitions related AMO variables */
 	(void)xpc_IPI_init_sn2(XPC_ENGAGED_PARTITIONS_AMO);
-	(void)xpc_IPI_init_sn2(XPC_DISENGAGE_REQUEST_AMO);
+	(void)xpc_IPI_init_sn2(XPC_DEACTIVATE_REQUEST_AMO);
 
 	return xpSuccess;
 }
@@ -671,7 +671,7 @@
 
 		/* pull the remote_hb cache line */
 		ret = xp_remote_memcpy(remote_vars,
-				       (void *)part->remote_vars_pa,
+				       (void *)part->sn.sn2.remote_vars_pa,
 				       XPC_RP_VARS_SIZE);
 		if (ret != xpSuccess) {
 			XPC_DEACTIVATE_PARTITION(part, ret);
@@ -726,10 +726,86 @@
 }
 
 static void
-xpc_initiate_partition_activation_sn2(struct xpc_rsvd_page *remote_rp,
-				      u64 remote_rp_pa, int nasid)
+xpc_request_partition_activation_sn2(struct xpc_rsvd_page *remote_rp,
+				     u64 remote_rp_pa, int nasid)
 {
-	xpc_IPI_send_local_activate(nasid);
+	xpc_activate_IRQ_send_local_sn2(nasid);
+}
+
+static void
+xpc_request_partition_reactivation_sn2(struct xpc_partition *part)
+{
+	xpc_activate_IRQ_send_local_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;
+	AMO_t *amo = (AMO_t *)__va(part_sn2->remote_amos_page_pa +
+				  (XPC_DEACTIVATE_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);
+
+	/*
+	 * Send activate IRQ to get other side to see that we've set our
+	 * bit in their deactivate request AMO.
+	 */
+	xpc_activate_IRQ_send_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;
+	AMO_t *amo = (AMO_t *)__va(part->sn.sn2.remote_amos_page_pa +
+				  (XPC_DEACTIVATE_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 int
+xpc_partition_deactivation_requested_sn2(short partid)
+{
+	AMO_t *amo = xpc_vars->amos_page + XPC_DEACTIVATE_REQUEST_AMO;
+
+	/* our partition's AMO variable ANDed with partid mask */
+	return (FETCHOP_LOAD_OP(TO_AMO((u64)&amo->variable), FETCHOP_LOAD) &
+		(1UL << partid)) != 0;
 }
 
 /*
@@ -741,6 +817,8 @@
 			      u64 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);
@@ -752,33 +830,34 @@
 	part->remote_rp_pa = remote_rp_pa;
 	dev_dbg(xpc_part, "  remote_rp_pa = 0x%016lx\n", part->remote_rp_pa);
 
-	part->remote_vars_pa = remote_vars_pa;
+	part_sn2->remote_vars_pa = remote_vars_pa;
 	dev_dbg(xpc_part, "  remote_vars_pa = 0x%016lx\n",
-		part->remote_vars_pa);
+		part_sn2->remote_vars_pa);
 
 	part->last_heartbeat = remote_vars->heartbeat;
 	dev_dbg(xpc_part, "  last_heartbeat = 0x%016lx\n",
 		part->last_heartbeat);
 
-	part->remote_vars_part_pa = remote_vars->vars_part_pa;
+	part_sn2->remote_vars_part_pa = remote_vars->vars_part_pa;
 	dev_dbg(xpc_part, "  remote_vars_part_pa = 0x%016lx\n",
-		part->remote_vars_part_pa);
+		part_sn2->remote_vars_part_pa);
 
-	part->remote_act_nasid = remote_vars->act_nasid;
-	dev_dbg(xpc_part, "  remote_act_nasid = 0x%x\n",
-		part->remote_act_nasid);
+	part_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->remote_act_phys_cpuid = remote_vars->act_phys_cpuid;
-	dev_dbg(xpc_part, "  remote_act_phys_cpuid = 0x%x\n",
-		part->remote_act_phys_cpuid);
+	part_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->remote_amos_page_pa = remote_vars->amos_page_pa;
+	part_sn2->remote_amos_page_pa = remote_vars->amos_page_pa;
 	dev_dbg(xpc_part, "  remote_amos_page_pa = 0x%lx\n",
-		part->remote_amos_page_pa);
+		part_sn2->remote_amos_page_pa);
 
-	part->remote_vars_version = remote_vars->version;
+	part_sn2->remote_vars_version = remote_vars->version;
 	dev_dbg(xpc_part, "  remote_vars_version = 0x%x\n",
-		part->remote_vars_version);
+		part_sn2->remote_vars_version);
 }
 
 /*
@@ -807,6 +886,7 @@
 	unsigned long remote_rp_stamp = 0;
 	short partid;
 	struct xpc_partition *part;
+	struct xpc_partition_sn2 *part_sn2;
 	enum xp_retval ret;
 
 	/* pull over the reserved page structure */
@@ -822,11 +902,11 @@
 
 	remote_vars_pa = remote_rp->sn.vars_pa;
 	remote_rp_version = remote_rp->version;
-	if (XPC_SUPPORTS_RP_STAMP(remote_rp_version))
-		remote_rp_stamp = remote_rp->stamp;
+	remote_rp_stamp = remote_rp->stamp;
 
 	partid = remote_rp->SAL_partid;
 	part = &xpc_partitions[partid];
+	part_sn2 = &part->sn.sn2;
 
 	/* pull over the cross partition variables */
 
@@ -834,7 +914,6 @@
 
 	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);
 
@@ -855,18 +934,12 @@
 					      &remote_rp_stamp, remote_rp_pa,
 					      remote_vars_pa, remote_vars);
 
-		if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version)) {
-			if (xpc_partition_disengage_requested(1UL << partid)) {
-				/*
-				 * Other side is waiting on us to disengage,
-				 * even though we already have.
-				 */
-				return;
-			}
-
-		} else {
-			/* other side doesn't support disengage requests */
-			xpc_clear_partition_disengage_request(1UL << partid);
+		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);
@@ -874,93 +947,30 @@
 	}
 
 	DBUG_ON(part->remote_rp_version == 0);
-	DBUG_ON(part->remote_vars_version == 0);
+	DBUG_ON(part_sn2->remote_vars_version == 0);
 
-	if (!XPC_SUPPORTS_RP_STAMP(part->remote_rp_version)) {
-		DBUG_ON(XPC_SUPPORTS_DISENGAGE_REQUEST(part->
-						       remote_vars_version));
+	if (remote_rp_stamp != part->remote_rp_stamp) {
 
-		if (!XPC_SUPPORTS_RP_STAMP(remote_rp_version)) {
-			DBUG_ON(XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->
-							       version));
-			/* see if the other side rebooted */
-			if (part->remote_amos_page_pa ==
-			    remote_vars->amos_page_pa &&
-			    xpc_hb_allowed(sn_partition_id,
-					  &remote_vars->heartbeating_to_mask)) {
-				/* doesn't look that way, so ignore the IPI */
-				return;
-			}
-		}
+		/* the other side rebooted */
 
-		/*
-		 * Other side rebooted and previous XPC didn't support the
-		 * disengage request, so we don't need to do anything special.
-		 */
-
-		xpc_update_partition_info_sn2(part, remote_rp_version,
-					      &remote_rp_stamp, remote_rp_pa,
-					      remote_vars_pa, remote_vars);
-		part->reactivate_nasid = nasid;
-		XPC_DEACTIVATE_PARTITION(part, xpReactivating);
-		return;
-	}
-
-	DBUG_ON(!XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version));
-
-	if (!XPC_SUPPORTS_RP_STAMP(remote_rp_version)) {
-		DBUG_ON(!XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->version));
-
-		/*
-		 * Other side rebooted and previous XPC did support the
-		 * disengage request, but the new one doesn't.
-		 */
-
-		xpc_clear_partition_engaged(1UL << partid);
-		xpc_clear_partition_disengage_request(1UL << partid);
+		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_stamp, remote_rp_pa,
 					      remote_vars_pa, remote_vars);
 		reactivate = 1;
-
-	} else {
-		DBUG_ON(!XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->version));
-
-		if (remote_rp_stamp != part->remote_rp_stamp) {
-
-			/*
-			 * Other side rebooted and the previous XPC did support
-			 * the disengage request, as does the new one.
-			 */
-
-			DBUG_ON(xpc_partition_engaged(1UL << partid));
-			DBUG_ON(xpc_partition_disengage_requested(1UL <<
-								  partid));
-
-			xpc_update_partition_info_sn2(part, remote_rp_version,
-						      &remote_rp_stamp,
-						      remote_rp_pa,
-						      remote_vars_pa,
-						      remote_vars);
-			reactivate = 1;
-		}
 	}
 
-	if (part->disengage_request_timeout > 0 &&
-	    !xpc_partition_disengaged(part)) {
+	if (part->disengage_timeout > 0 && !xpc_partition_disengaged(part)) {
 		/* still waiting on other side to disengage from us */
 		return;
 	}
 
-	if (reactivate) {
-		part->reactivate_nasid = nasid;
+	if (reactivate)
 		XPC_DEACTIVATE_PARTITION(part, xpReactivating);
-
-	} else if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version) &&
-		   xpc_partition_disengage_requested(1UL << partid)) {
+	else if (xpc_partition_deactivation_requested_sn2(partid))
 		XPC_DEACTIVATE_PARTITION(part, xpOtherGoingDown);
-	}
 }
 
 /*
@@ -1038,6 +1048,7 @@
 static enum xp_retval
 xpc_setup_infrastructure_sn2(struct xpc_partition *part)
 {
+	struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
 	enum xp_retval retval;
 	int ret;
 	int cpuid;
@@ -1060,28 +1071,29 @@
 
 	/* allocate all the required GET/PUT values */
 
-	part->local_GPs = xpc_kzalloc_cacheline_aligned(XPC_GP_SIZE,
-							GFP_KERNEL,
-							&part->local_GPs_base);
-	if (part->local_GPs == NULL) {
+	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");
 		retval = xpNoMemory;
 		goto out_1;
 	}
 
-	part->remote_GPs = xpc_kzalloc_cacheline_aligned(XPC_GP_SIZE,
-							 GFP_KERNEL,
-							 &part->
-							 remote_GPs_base);
-	if (part->remote_GPs == NULL) {
+	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_2;
 	}
 
-	part->remote_GPs_pa = 0;
+	part_sn2->remote_GPs_pa = 0;
 
 	/* allocate all the required open and close args */
 
@@ -1103,22 +1115,23 @@
 		goto out_4;
 	}
 
-	part->remote_openclose_args_pa = 0;
+	part_sn2->remote_openclose_args_pa = 0;
 
-	part->local_IPI_amo_va = xpc_IPI_init_sn2(partid);
+	part_sn2->local_IPI_amo_va = xpc_IPI_init_sn2(partid);
 	part->local_IPI_amo = 0;
 	spin_lock_init(&part->IPI_lock);
 
-	part->remote_IPI_nasid = 0;
-	part->remote_IPI_phys_cpuid = 0;
-	part->remote_IPI_amo_va = NULL;
+	part_sn2->remote_IPI_nasid = 0;
+	part_sn2->remote_IPI_phys_cpuid = 0;
+	part_sn2->remote_IPI_amo_va = NULL;
 
 	atomic_set(&part->channel_mgr_requests, 1);
 	init_waitqueue_head(&part->channel_mgr_wq);
 
-	sprintf(part->IPI_owner, "xpc%02d", partid);
-	ret = request_irq(SGI_XPC_NOTIFY, xpc_notify_IRQ_handler, IRQF_SHARED,
-			  part->IPI_owner, (void *)(u64)partid);
+	sprintf(part_sn2->IPI_owner, "xpc%02d", partid);
+	ret = request_irq(SGI_XPC_NOTIFY, xpc_handle_notify_IRQ_sn2,
+			  IRQF_SHARED, part_sn2->IPI_owner,
+			  (void *)(u64)partid);
 	if (ret != 0) {
 		dev_err(xpc_chan, "can't register NOTIFY IRQ handler, "
 			"errno=%d\n", -ret);
@@ -1127,9 +1140,10 @@
 	}
 
 	/* Setup a timer to check for dropped IPIs */
-	timer = &part->dropped_IPI_timer;
+	timer = &part_sn2->dropped_notify_IRQ_timer;
 	init_timer(timer);
-	timer->function = (void (*)(unsigned long))xpc_dropped_IPI_check;
+	timer->function =
+	    (void (*)(unsigned long))xpc_dropped_notify_IRQ_check_sn2;
 	timer->data = (unsigned long)part;
 	timer->expires = jiffies + XPC_P_DROPPED_IPI_WAIT_INTERVAL;
 	add_timer(timer);
@@ -1146,7 +1160,7 @@
 		ch->number = ch_number;
 		ch->flags = XPC_C_DISCONNECTED;
 
-		ch->local_GP = &part->local_GPs[ch_number];
+		ch->sn.sn2.local_GP = &part_sn2->local_GPs[ch_number];
 		ch->local_openclose_args =
 		    &part->local_openclose_args[ch_number];
 
@@ -1158,7 +1172,7 @@
 		atomic_set(&ch->n_to_notify, 0);
 
 		spin_lock_init(&ch->lock);
-		mutex_init(&ch->msg_to_pull_mutex);
+		mutex_init(&ch->sn.sn2.msg_to_pull_mutex);
 		init_completion(&ch->wdisconnect_wait);
 
 		atomic_set(&ch->n_on_msg_allocate_wq, 0);
@@ -1179,10 +1193,10 @@
 	 * The setting of the magic # indicates that these per partition
 	 * specific variables are ready to be used.
 	 */
-	xpc_vars_part[partid].GPs_pa = __pa(part->local_GPs);
+	xpc_vars_part[partid].GPs_pa = __pa(part_sn2->local_GPs);
 	xpc_vars_part[partid].openclose_args_pa =
 	    __pa(part->local_openclose_args);
-	xpc_vars_part[partid].IPI_amo_pa = __pa(part->local_IPI_amo_va);
+	xpc_vars_part[partid].IPI_amo_pa = __pa(part_sn2->local_IPI_amo_va);
 	cpuid = raw_smp_processor_id();	/* any CPU in this partition will do */
 	xpc_vars_part[partid].IPI_nasid = cpuid_to_nasid(cpuid);
 	xpc_vars_part[partid].IPI_phys_cpuid = cpu_physical_id(cpuid);
@@ -1199,11 +1213,11 @@
 	kfree(part->local_openclose_args_base);
 	part->local_openclose_args = NULL;
 out_3:
-	kfree(part->remote_GPs_base);
-	part->remote_GPs = NULL;
+	kfree(part_sn2->remote_GPs_base);
+	part_sn2->remote_GPs = NULL;
 out_2:
-	kfree(part->local_GPs_base);
-	part->local_GPs = NULL;
+	kfree(part_sn2->local_GPs_base);
+	part_sn2->local_GPs = NULL;
 out_1:
 	kfree(part->channels);
 	part->channels = NULL;
@@ -1217,6 +1231,7 @@
 static void
 xpc_teardown_infrastructure_sn2(struct xpc_partition *part)
 {
+	struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
 	short partid = XPC_PARTID(part);
 
 	/*
@@ -1248,19 +1263,19 @@
 	part->setup_state = XPC_P_TORNDOWN;
 
 	/* in case we've still got outstanding timers registered... */
-	del_timer_sync(&part->dropped_IPI_timer);
+	del_timer_sync(&part_sn2->dropped_notify_IRQ_timer);
 
 	kfree(part->remote_openclose_args_base);
 	part->remote_openclose_args = NULL;
 	kfree(part->local_openclose_args_base);
 	part->local_openclose_args = NULL;
-	kfree(part->remote_GPs_base);
-	part->remote_GPs = NULL;
-	kfree(part->local_GPs_base);
-	part->local_GPs = NULL;
+	kfree(part_sn2->remote_GPs_base);
+	part_sn2->remote_GPs = NULL;
+	kfree(part_sn2->local_GPs_base);
+	part_sn2->local_GPs = NULL;
 	kfree(part->channels);
 	part->channels = NULL;
-	part->local_IPI_amo_va = NULL;
+	part_sn2->local_IPI_amo_va = NULL;
 }
 
 /*
@@ -1300,6 +1315,7 @@
 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);
@@ -1310,11 +1326,11 @@
 
 	/* pull the cacheline that contains the variables we're interested in */
 
-	DBUG_ON(part->remote_vars_part_pa !=
-		L1_CACHE_ALIGN(part->remote_vars_part_pa));
+	DBUG_ON(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->remote_vars_part_pa +
+	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));
@@ -1364,13 +1380,13 @@
 
 		/* the variables we imported look to be valid */
 
-		part->remote_GPs_pa = pulled_entry->GPs_pa;
-		part->remote_openclose_args_pa =
+		part_sn2->remote_GPs_pa = pulled_entry->GPs_pa;
+		part_sn2->remote_openclose_args_pa =
 		    pulled_entry->openclose_args_pa;
-		part->remote_IPI_amo_va =
+		part_sn2->remote_IPI_amo_va =
 		    (AMO_t *)__va(pulled_entry->IPI_amo_pa);
-		part->remote_IPI_nasid = pulled_entry->IPI_nasid;
-		part->remote_IPI_phys_cpuid = pulled_entry->IPI_phys_cpuid;
+		part_sn2->remote_IPI_nasid = pulled_entry->IPI_nasid;
+		part_sn2->remote_IPI_phys_cpuid = pulled_entry->IPI_phys_cpuid;
 
 		if (part->nchannels > pulled_entry->nchannels)
 			part->nchannels = pulled_entry->nchannels;
@@ -1394,6 +1410,7 @@
 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;
 
 	/*
@@ -1406,7 +1423,7 @@
 	 * we should get the same page for remote_amos_page_pa after module
 	 * reloads and system reboots.
 	 */
-	if (sn_register_xp_addr_region(part->remote_amos_page_pa,
+	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));
@@ -1416,7 +1433,14 @@
 		return ret;
 	}
 
-	xpc_IPI_send_activated(part);
+	/*
+	 * Send activate IRQ to get other side to activate if they've not
+	 * already begun to do so.
+	 */
+	xpc_activate_IRQ_send_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) {
@@ -1443,6 +1467,7 @@
 static u64
 xpc_get_IPI_flags_sn2(struct xpc_partition *part)
 {
+	struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
 	unsigned long irq_flags;
 	u64 IPI_amo;
 	enum xp_retval ret;
@@ -1459,9 +1484,9 @@
 	spin_unlock_irqrestore(&part->IPI_lock, irq_flags);
 
 	if (XPC_ANY_OPENCLOSE_IPI_FLAGS_SET(IPI_amo)) {
-		ret = xpc_pull_remote_cachelines_sn2(part,
-						    part->remote_openclose_args,
-						     (void *)part->
+		ret = xpc_pull_remote_cachelines_sn2(part, part->
+						     remote_openclose_args,
+						     (void *)part_sn2->
 						     remote_openclose_args_pa,
 						     XPC_OPENCLOSE_ARGS_SIZE);
 		if (ret != xpSuccess) {
@@ -1477,8 +1502,8 @@
 	}
 
 	if (XPC_ANY_MSG_IPI_FLAGS_SET(IPI_amo)) {
-		ret = xpc_pull_remote_cachelines_sn2(part, part->remote_GPs,
-						    (void *)part->remote_GPs_pa,
+		ret = xpc_pull_remote_cachelines_sn2(part, part_sn2->remote_GPs,
+						(void *)part_sn2->remote_GPs_pa,
 						     XPC_GP_SIZE);
 		if (ret != xpSuccess) {
 			XPC_DEACTIVATE_PARTITION(part, ret);
@@ -1494,28 +1519,220 @@
 	return IPI_amo;
 }
 
+/*
+ * 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 *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->notify_queue[get % ch->local_nentries];
+
+		/*
+		 * See if the notify entry indicates it was associated with
+		 * a message who's sender wants to be notified. It is possible
+		 * that it is, but someone else is doing or has done the
+		 * notification.
+		 */
+		notify_type = notify->type;
+		if (notify_type == 0 ||
+		    cmpxchg(&notify->type, notify_type, 0) != notify_type) {
+			continue;
+		}
+
+		DBUG_ON(notify_type != XPC_N_CALL);
+
+		atomic_dec(&ch->n_to_notify);
+
+		if (notify->func != NULL) {
+			dev_dbg(xpc_chan, "notify->func() called, notify=0x%p, "
+				"msg_number=%ld, partid=%d, channel=%d\n",
+				(void *)notify, get, ch->partid, ch->number);
+
+			notify->func(reason, ch->partid, ch->number,
+				     notify->key);
+
+			dev_dbg(xpc_chan, "notify->func() returned, "
+				"notify=0x%p, msg_number=%ld, partid=%d, "
+				"channel=%d\n", (void *)notify, get,
+				ch->partid, ch->number);
+		}
+	}
+}
+
+static void
+xpc_notify_senders_of_disconnect_sn2(struct xpc_channel *ch)
+{
+	xpc_notify_senders_sn2(ch, ch->reason, ch->sn.sn2.w_local_GP.put);
+}
+
+/*
+ * Clear some of the msg flags in the local message queue.
+ */
+static inline void
+xpc_clear_local_msgqueue_flags_sn2(struct xpc_channel *ch)
+{
+	struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
+	struct xpc_msg *msg;
+	s64 get;
+
+	get = ch_sn2->w_remote_GP.get;
+	do {
+		msg = (struct xpc_msg *)((u64)ch->local_msgqueue +
+					 (get % ch->local_nentries) *
+					 ch->msg_size);
+		msg->flags = 0;
+	} while (++get < ch_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 *msg;
+	s64 put;
+
+	put = ch_sn2->w_remote_GP.put;
+	do {
+		msg = (struct xpc_msg *)((u64)ch->remote_msgqueue +
+					 (put % ch->remote_nentries) *
+					 ch->msg_size);
+		msg->flags = 0;
+	} while (++put < ch_sn2->remote_GP.put);
+}
+
+static void
+xpc_process_msg_IPI_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 nmsgs_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_msg().
+		 */
+		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);
+
+		nmsgs_sent = ch_sn2->w_remote_GP.put - ch_sn2->w_local_GP.get;
+		if (nmsgs_sent > 0) {
+			dev_dbg(xpc_chan, "msgs waiting to be copied and "
+				"delivered=%d, partid=%d, channel=%d\n",
+				nmsgs_sent, ch->partid, ch->number);
+
+			if (ch->flags & XPC_C_CONNECTEDCALLOUT_MADE)
+				xpc_activate_kthreads(ch, nmsgs_sent);
+		}
+	}
+
+	xpc_msgqueue_deref(ch);
+}
+
 static struct xpc_msg *
 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;
 	struct xpc_msg *remote_msg, *msg;
 	u32 msg_index, nmsgs;
 	u64 msg_offset;
 	enum xp_retval ret;
 
-	if (mutex_lock_interruptible(&ch->msg_to_pull_mutex) != 0) {
+	if (mutex_lock_interruptible(&ch_sn2->msg_to_pull_mutex) != 0) {
 		/* we were interrupted by a signal */
 		return NULL;
 	}
 
-	while (get >= ch->next_msg_to_pull) {
+	while (get >= ch_sn2->next_msg_to_pull) {
 
 		/* pull as many messages as are ready and able to be pulled */
 
-		msg_index = ch->next_msg_to_pull % ch->remote_nentries;
+		msg_index = ch_sn2->next_msg_to_pull % ch->remote_nentries;
 
-		DBUG_ON(ch->next_msg_to_pull >= ch->w_remote_GP.put);
-		nmsgs = ch->w_remote_GP.put - ch->next_msg_to_pull;
+		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;
@@ -1532,19 +1749,19 @@
 
 			dev_dbg(xpc_chan, "failed to pull %d msgs starting with"
 				" msg %ld from partition %d, channel=%d, "
-				"ret=%d\n", nmsgs, ch->next_msg_to_pull,
+				"ret=%d\n", nmsgs, ch_sn2->next_msg_to_pull,
 				ch->partid, ch->number, ret);
 
 			XPC_DEACTIVATE_PARTITION(part, ret);
 
-			mutex_unlock(&ch->msg_to_pull_mutex);
+			mutex_unlock(&ch_sn2->msg_to_pull_mutex);
 			return NULL;
 		}
 
-		ch->next_msg_to_pull += nmsgs;
+		ch_sn2->next_msg_to_pull += nmsgs;
 	}
 
-	mutex_unlock(&ch->msg_to_pull_mutex);
+	mutex_unlock(&ch_sn2->msg_to_pull_mutex);
 
 	/* return the message we were looking for */
 	msg_offset = (get % ch->remote_nentries) * ch->msg_size;
@@ -1553,12 +1770,19 @@
 	return msg;
 }
 
+static int
+xpc_n_of_deliverable_msgs_sn2(struct xpc_channel *ch)
+{
+	return ch->sn.sn2.w_remote_GP.put - ch->sn.sn2.w_local_GP.get;
+}
+
 /*
  * Get a message to be delivered.
  */
 static struct xpc_msg *
 xpc_get_deliverable_msg_sn2(struct xpc_channel *ch)
 {
+	struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
 	struct xpc_msg *msg = NULL;
 	s64 get;
 
@@ -1566,9 +1790,9 @@
 		if (ch->flags & XPC_C_DISCONNECTING)
 			break;
 
-		get = ch->w_local_GP.get;
+		get = ch_sn2->w_local_GP.get;
 		rmb();	/* guarantee that .get loads before .put */
-		if (get == ch->w_remote_GP.put)
+		if (get == ch_sn2->w_remote_GP.put)
 			break;
 
 		/* There are messages waiting to be pulled and delivered.
@@ -1578,7 +1802,7 @@
 		 * to try again for the next one.
 		 */
 
-		if (cmpxchg(&ch->w_local_GP.get, get, get + 1) == get) {
+		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, "
@@ -1609,6 +1833,7 @@
 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 *msg;
 	s64 put = initial_put + 1;
 	int send_IPI = 0;
@@ -1616,7 +1841,7 @@
 	while (1) {
 
 		while (1) {
-			if (put == ch->w_local_GP.put)
+			if (put == ch_sn2->w_local_GP.put)
 				break;
 
 			msg = (struct xpc_msg *)((u64)ch->local_msgqueue +
@@ -1634,10 +1859,10 @@
 			break;
 		}
 
-		if (cmpxchg_rel(&ch->local_GP->put, initial_put, put) !=
+		if (cmpxchg_rel(&ch_sn2->local_GP->put, initial_put, put) !=
 		    initial_put) {
 			/* someone else beat us to it */
-			DBUG_ON(ch->local_GP->put < initial_put);
+			DBUG_ON(ch_sn2->local_GP->put < initial_put);
 			break;
 		}
 
@@ -1657,7 +1882,7 @@
 	}
 
 	if (send_IPI)
-		xpc_IPI_send_msgrequest_sn2(ch);
+		xpc_send_channel_msgrequest_sn2(ch);
 }
 
 /*
@@ -1668,6 +1893,7 @@
 xpc_allocate_msg_sn2(struct xpc_channel *ch, u32 flags,
 		     struct xpc_msg **address_of_msg)
 {
+	struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
 	struct xpc_msg *msg;
 	enum xp_retval ret;
 	s64 put;
@@ -1681,9 +1907,9 @@
 
 	while (1) {
 
-		put = ch->w_local_GP.put;
+		put = ch_sn2->w_local_GP.put;
 		rmb();	/* guarantee that .put loads before .get */
-		if (put - ch->w_remote_GP.get < ch->local_nentries) {
+		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
@@ -1691,7 +1917,8 @@
 			 * 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) {
+			if (cmpxchg(&ch_sn2->w_local_GP.put, put, put + 1) ==
+			    put) {
 				/* we got the entry referenced by put */
 				break;
 			}
@@ -1708,7 +1935,7 @@
 		 * GP values as if an IPI was sent by the other side.
 		 */
 		if (ret == xpTimeout)
-			xpc_IPI_send_local_msgrequest_sn2(ch);
+			xpc_send_channel_local_msgrequest_sn2(ch);
 
 		if (flags & XPC_NOWAIT)
 			return xpNoWait;
@@ -1810,13 +2037,13 @@
 
 	/*
 	 * The preceding store of msg->flags must occur before the following
-	 * load of ch->local_GP->put.
+	 * load of local_GP->put.
 	 */
 	mb();
 
 	/* see if the message is next in line to be sent, if so send it */
 
-	put = ch->local_GP->put;
+	put = ch->sn.sn2.local_GP->put;
 	if (put == msg_number)
 		xpc_send_msgs_sn2(ch, put);
 
@@ -1833,6 +2060,7 @@
 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 *msg;
 	s64 get = initial_get + 1;
 	int send_IPI = 0;
@@ -1840,7 +2068,7 @@
 	while (1) {
 
 		while (1) {
-			if (get == ch->w_local_GP.get)
+			if (get == ch_sn2->w_local_GP.get)
 				break;
 
 			msg = (struct xpc_msg *)((u64)ch->remote_msgqueue +
@@ -1859,10 +2087,10 @@
 			break;
 		}
 
-		if (cmpxchg_rel(&ch->local_GP->get, initial_get, get) !=
+		if (cmpxchg_rel(&ch_sn2->local_GP->get, initial_get, get) !=
 		    initial_get) {
 			/* someone else beat us to it */
-			DBUG_ON(ch->local_GP->get <= initial_get);
+			DBUG_ON(ch_sn2->local_GP->get <= initial_get);
 			break;
 		}
 
@@ -1882,7 +2110,7 @@
 	}
 
 	if (send_IPI)
-		xpc_IPI_send_msgrequest_sn2(ch);
+		xpc_send_channel_msgrequest_sn2(ch);
 }
 
 static void
@@ -1902,7 +2130,7 @@
 
 	/*
 	 * The preceding store of msg->flags must occur before the following
-	 * load of ch->local_GP->get.
+	 * load of local_GP->get.
 	 */
 	mb();
 
@@ -1910,7 +2138,7 @@
 	 * See if this message is next in line to be acknowledged as having
 	 * been delivered.
 	 */
-	get = ch->local_GP->get;
+	get = ch->sn.sn2.local_GP->get;
 	if (get == msg_number)
 		xpc_acknowledge_msgs_sn2(ch, get, msg->flags);
 }
@@ -1928,36 +2156,35 @@
 	xpc_heartbeat_exit = xpc_heartbeat_exit_sn2;
 	xpc_check_remote_hb = xpc_check_remote_hb_sn2;
 
-	xpc_initiate_partition_activation =
-	    xpc_initiate_partition_activation_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_infrastructure = xpc_setup_infrastructure_sn2;
 	xpc_teardown_infrastructure = xpc_teardown_infrastructure_sn2;
 	xpc_make_first_contact = xpc_make_first_contact_sn2;
 	xpc_get_IPI_flags = xpc_get_IPI_flags_sn2;
+	xpc_notify_senders_of_disconnect = xpc_notify_senders_of_disconnect_sn2;
+	xpc_process_msg_IPI = xpc_process_msg_IPI_sn2;
+	xpc_n_of_deliverable_msgs = xpc_n_of_deliverable_msgs_sn2;
 	xpc_get_deliverable_msg = xpc_get_deliverable_msg_sn2;
 
-	xpc_mark_partition_engaged = xpc_mark_partition_engaged_sn2;
-	xpc_mark_partition_disengaged = xpc_mark_partition_disengaged_sn2;
-	xpc_request_partition_disengage = xpc_request_partition_disengage_sn2;
-	xpc_cancel_partition_disengage_request =
-	    xpc_cancel_partition_disengage_request_sn2;
+	xpc_indicate_partition_engaged = xpc_indicate_partition_engaged_sn2;
 	xpc_partition_engaged = xpc_partition_engaged_sn2;
-	xpc_partition_disengage_requested =
-	    xpc_partition_disengage_requested_sn2;
-	xpc_clear_partition_engaged = xpc_clear_partition_engaged_sn2;
-	xpc_clear_partition_disengage_request =
-	    xpc_clear_partition_disengage_request_sn2;
+	xpc_any_partition_engaged = xpc_any_partition_engaged_sn2;
+	xpc_indicate_partition_disengaged =
+	    xpc_indicate_partition_disengaged_sn2;
+	xpc_assume_partition_disengaged = xpc_assume_partition_disengaged_sn2;
 
-	xpc_IPI_send_local_activate = xpc_IPI_send_local_activate_sn2;
-	xpc_IPI_send_activated = xpc_IPI_send_activated_sn2;
-	xpc_IPI_send_local_reactivate = xpc_IPI_send_local_reactivate_sn2;
-	xpc_IPI_send_disengage = xpc_IPI_send_disengage_sn2;
-
-	xpc_IPI_send_closerequest = xpc_IPI_send_closerequest_sn2;
-	xpc_IPI_send_closereply = xpc_IPI_send_closereply_sn2;
-	xpc_IPI_send_openrequest = xpc_IPI_send_openrequest_sn2;
-	xpc_IPI_send_openreply = xpc_IPI_send_openreply_sn2;
+	xpc_send_channel_closerequest = xpc_send_channel_closerequest_sn2;
+	xpc_send_channel_closereply = xpc_send_channel_closereply_sn2;
+	xpc_send_channel_openrequest = xpc_send_channel_openrequest_sn2;
+	xpc_send_channel_openreply = xpc_send_channel_openreply_sn2;
 
 	xpc_send_msg = xpc_send_msg_sn2;
 	xpc_received_msg = xpc_received_msg_sn2;
diff --git a/drivers/misc/sgi-xp/xpc_uv.c b/drivers/misc/sgi-xp/xpc_uv.c
index 32c577b..c53b229 100644
--- a/drivers/misc/sgi-xp/xpc_uv.c
+++ b/drivers/misc/sgi-xp/xpc_uv.c
@@ -63,8 +63,8 @@
 }
 
 static void
-xpc_initiate_partition_activation_uv(struct xpc_rsvd_page *remote_rp,
-				     u64 remote_rp_pa, int nasid)
+xpc_request_partition_activation_uv(struct xpc_rsvd_page *remote_rp,
+				    u64 remote_rp_pa, int nasid)
 {
 	short partid = remote_rp->SAL_partid;
 	struct xpc_partition *part = &xpc_partitions[partid];
@@ -78,6 +78,12 @@
 	xpc_IPI_send_local_activate_uv(part);
 }
 
+static void
+xpc_request_partition_reactivation_uv(struct xpc_partition *part)
+{
+	xpc_IPI_send_local_activate_uv(part);
+}
+
 /*
  * Setup the infrastructure necessary to support XPartition Communication
  * between the specified remote partition and the local one.
@@ -128,8 +134,9 @@
 	xpc_increment_heartbeat = xpc_increment_heartbeat_uv;
 	xpc_heartbeat_init = xpc_heartbeat_init_uv;
 	xpc_heartbeat_exit = xpc_heartbeat_exit_uv;
-	xpc_initiate_partition_activation =
-	    xpc_initiate_partition_activation_uv;
+	xpc_request_partition_activation = xpc_request_partition_activation_uv;
+	xpc_request_partition_reactivation =
+	    xpc_request_partition_reactivation_uv;
 	xpc_setup_infrastructure = xpc_setup_infrastructure_uv;
 	xpc_teardown_infrastructure = xpc_teardown_infrastructure_uv;
 	xpc_make_first_contact = xpc_make_first_contact_uv;