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>

6 files changed, 784 insertions, 806 deletions

diff --git a/drivers/misc/sgi-xp/xpc.h b/drivers/misc/sgi-xp/xpc.h
index 1edf37512de..b04cfbed958 100644
--- a/drivers/misc/sgi-xp/xpc.h
+++ b/drivers/misc/sgi-xp/xpc.h
@@ -122,9 +122,6 @@ struct xpc_rsvd_page {
 
 #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 @@ struct xpc_vars_sn2 {
 	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 @@ struct xpc_vars_sn2 {
 
 #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 @@ struct xpc_vars_sn2 {
  * 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 @@ struct xpc_notify {
  *	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 @@ struct xpc_channel {
 	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 @@ struct xpc_channel {
 
 	wait_queue_head_t idle_wq;	/* idle kthread wait queue */
 
+	union {
+		struct xpc_channel_sn2 sn2;
+		struct xpc_channel_uv uv;
+	} sn;
+
 } ____cacheline_aligned;
 
 /* struct xpc_channel flags */
@@ -467,6 +474,40 @@ struct xpc_channel {
  * 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 @@ struct xpc_partition {
 	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 @@ struct xpc_partition {
 	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 @@ struct xpc_partition {
 	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 @@ struct xpc_partition {
 	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 @@ struct xpc_partition {
 #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 @@ extern struct xpc_registration xpc_registrations[];
 /* found in xpc_main.c */
 extern struct device *xpc_part;
 extern struct device *xpc_chan;
-extern int xpc_disengage_request_timelimit;
-extern int xpc_disengage_request_timedout;
+extern 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_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 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_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_indicate_partition_engaged) (struct xpc_partition *);
+extern int (*xpc_partition_engaged) (short);
+extern int (*xpc_any_partition_engaged) (void);
+extern void (*xpc_indicate_partition_disengaged) (struct xpc_partition *);
+extern void (*xpc_assume_partition_disengaged) (short);
+
+extern void (*xpc_send_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 char *xpc_remote_copy_buffer;
 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 55182c8dd32..48b16136305 100644
--- a/drivers/misc/sgi-xp/xpc_channel.c
+++ b/drivers/misc/sgi-xp/xpc_channel.c
@@ -201,7 +201,7 @@ xpc_process_connect(struct xpc_channel *ch, unsigned long *irq_flags)
 
 	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 @@ xpc_process_connect(struct xpc_channel *ch, unsigned long *irq_flags)
 }
 
 /*
- * Notify those who wanted to be notified upon delivery of their message.
- */
-static void
-xpc_notify_senders(struct xpc_channel *ch, enum xp_retval reason, s64 put)
-{
-	struct xpc_notify *notify;
-	u8 notify_type;
-	s64 get = ch->w_remote_GP.get - 1;
-
-	while (++get < put && atomic_read(&ch->n_to_notify) > 0) {
-
-		notify = &ch->notify_queue[get % ch->local_nentries];
-
-		/*
-		 * See if the notify entry indicates it was associated with
-		 * a message who's sender wants to be notified. It is possible
-		 * that it is, but someone else is doing or has done the
-		 * notification.
-		 */
-		notify_type = notify->type;
-		if (notify_type == 0 ||
-		    cmpxchg(&notify->type, notify_type, 0) != notify_type) {
-			continue;
-		}
-
-		DBUG_ON(notify_type != XPC_N_CALL);
-
-		atomic_dec(&ch->n_to_notify);
-
-		if (notify->func != NULL) {
-			dev_dbg(xpc_chan, "notify->func() called, notify=0x%p, "
-				"msg_number=%ld, partid=%d, channel=%d\n",
-				(void *)notify, get, ch->partid, ch->number);
-
-			notify->func(reason, ch->partid, ch->number,
-				     notify->key);
-
-			dev_dbg(xpc_chan, "notify->func() returned, "
-				"notify=0x%p, msg_number=%ld, partid=%d, "
-				"channel=%d\n", (void *)notify, get,
-				ch->partid, ch->number);
-		}
-	}
-}
-
-/*
  * Free up message queues and other stuff that were allocated for the specified
  * channel.
  *
@@ -275,6 +229,8 @@ xpc_notify_senders(struct xpc_channel *ch, enum xp_retval reason, s64 put)
 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 @@ xpc_free_msgqueues(struct xpc_channel *ch)
 	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 @@ xpc_process_disconnect(struct xpc_channel *ch, unsigned long *irq_flags)
 
 	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 @@ xpc_process_disconnect(struct xpc_channel *ch, unsigned long *irq_flags)
 
 		if (!(ch->flags & XPC_C_CLOSEREPLY)) {
 			ch->flags |= XPC_C_CLOSEREPLY;
-			xpc_IPI_send_closereply(ch, irq_flags);
+			xpc_send_channel_closereply(ch, irq_flags);
 		}
 
 		if (!(ch->flags & XPC_C_RCLOSEREPLY))
@@ -361,7 +317,7 @@ xpc_process_disconnect(struct xpc_channel *ch, unsigned long *irq_flags)
 	/* wake those waiting for notify completion */
 	if (atomic_read(&ch->n_to_notify) > 0) {
 		/* >>> we do callout while holding ch->lock */
-		xpc_notify_senders(ch, ch->reason, ch->w_local_GP.put);
+		xpc_notify_senders_of_disconnect(ch);
 	}
 
 	/* both sides are disconnected now */
@@ -734,7 +690,7 @@ xpc_connect_channel(struct xpc_channel *ch)
 	/* initiate the connection */
 
 	ch->flags |= (XPC_C_OPENREQUEST | XPC_C_CONNECTING);
-	xpc_IPI_send_openrequest(ch, &irq_flags);
+	xpc_send_channel_openrequest(ch, &irq_flags);
 
 	xpc_process_connect(ch, &irq_flags);
 
@@ -743,142 +699,6 @@ xpc_connect_channel(struct xpc_channel *ch)
 	return xpSuccess;
 }
 
-/*
- * Clear some of the msg flags in the local message queue.
- */
-static inline void
-xpc_clear_local_msgqueue_flags(struct xpc_channel *ch)
-{
-	struct xpc_msg *msg;
-	s64 get;
-
-	get = ch->w_remote_GP.get;
-	do {
-		msg = (struct xpc_msg *)((u64)ch->local_msgqueue +
-					 (get % ch->local_nentries) *
-					 ch->msg_size);
-		msg->flags = 0;
-	} while (++get < ch->remote_GP.get);
-}
-
-/*
- * Clear some of the msg flags in the remote message queue.
- */
-static inline void
-xpc_clear_remote_msgqueue_flags(struct xpc_channel *ch)
-{
-	struct xpc_msg *msg;
-	s64 put;
-
-	put = ch->w_remote_GP.put;
-	do {
-		msg = (struct xpc_msg *)((u64)ch->remote_msgqueue +
-					 (put % ch->remote_nentries) *
-					 ch->msg_size);
-		msg->flags = 0;
-	} while (++put < ch->remote_GP.put);
-}
-
-static void
-xpc_process_msg_IPI(struct xpc_partition *part, int ch_number)
-{
-	struct xpc_channel *ch = &part->channels[ch_number];
-	int nmsgs_sent;
-
-	ch->remote_GP = part->remote_GPs[ch_number];
-
-	/* See what, if anything, has changed for each connected channel */
-
-	xpc_msgqueue_ref(ch);
-
-	if (ch->w_remote_GP.get == ch->remote_GP.get &&
-	    ch->w_remote_GP.put == ch->remote_GP.put) {
-		/* nothing changed since GPs were last pulled */
-		xpc_msgqueue_deref(ch);
-		return;
-	}
-
-	if (!(ch->flags & XPC_C_CONNECTED)) {
-		xpc_msgqueue_deref(ch);
-		return;
-	}
-
-	/*
-	 * First check to see if messages recently sent by us have been
-	 * received by the other side. (The remote GET value will have
-	 * changed since we last looked at it.)
-	 */
-
-	if (ch->w_remote_GP.get != ch->remote_GP.get) {
-
-		/*
-		 * We need to notify any senders that want to be notified
-		 * that their sent messages have been received by their
-		 * intended recipients. We need to do this before updating
-		 * w_remote_GP.get so that we don't allocate the same message
-		 * queue entries prematurely (see xpc_allocate_msg()).
-		 */
-		if (atomic_read(&ch->n_to_notify) > 0) {
-			/*
-			 * Notify senders that messages sent have been
-			 * received and delivered by the other side.
-			 */
-			xpc_notify_senders(ch, xpMsgDelivered,
-					   ch->remote_GP.get);
-		}
-
-		/*
-		 * Clear msg->flags in previously sent messages, so that
-		 * they're ready for xpc_allocate_msg().
-		 */
-		xpc_clear_local_msgqueue_flags(ch);
-
-		ch->w_remote_GP.get = ch->remote_GP.get;
-
-		dev_dbg(xpc_chan, "w_remote_GP.get changed to %ld, partid=%d, "
-			"channel=%d\n", ch->w_remote_GP.get, ch->partid,
-			ch->number);
-
-		/*
-		 * If anyone was waiting for message queue entries to become
-		 * available, wake them up.
-		 */
-		if (atomic_read(&ch->n_on_msg_allocate_wq) > 0)
-			wake_up(&ch->msg_allocate_wq);
-	}
-
-	/*
-	 * Now check for newly sent messages by the other side. (The remote
-	 * PUT value will have changed since we last looked at it.)
-	 */
-
-	if (ch->w_remote_GP.put != ch->remote_GP.put) {
-		/*
-		 * Clear msg->flags in previously received messages, so that
-		 * they're ready for xpc_get_deliverable_msg().
-		 */
-		xpc_clear_remote_msgqueue_flags(ch);
-
-		ch->w_remote_GP.put = ch->remote_GP.put;
-
-		dev_dbg(xpc_chan, "w_remote_GP.put changed to %ld, partid=%d, "
-			"channel=%d\n", ch->w_remote_GP.put, ch->partid,
-			ch->number);
-
-		nmsgs_sent = ch->w_remote_GP.put - ch->w_local_GP.get;
-		if (nmsgs_sent > 0) {
-			dev_dbg(xpc_chan, "msgs waiting to be copied and "
-				"delivered=%d, partid=%d, channel=%d\n",
-				nmsgs_sent, ch->partid, ch->number);
-
-			if (ch->flags & XPC_C_CONNECTEDCALLOUT_MADE)
-				xpc_activate_kthreads(ch, nmsgs_sent);
-		}
-	}
-
-	xpc_msgqueue_deref(ch);
-}
-
 void
 xpc_process_channel_activity(struct xpc_partition *part)
 {
@@ -1117,7 +937,7 @@ xpc_disconnect_channel(const int line, struct xpc_channel *ch,
 		       XPC_C_ROPENREQUEST | XPC_C_ROPENREPLY |
 		       XPC_C_CONNECTING | XPC_C_CONNECTED);
 
-	xpc_IPI_send_closerequest(ch, irq_flags);
+	xpc_send_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 8780d5d00f6..563aaf4a2ff 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_interval = XPC_HB_CHECK_DEFAULT_INTERVAL;
 static int xpc_hb_check_min_interval = 10;
 static int xpc_hb_check_max_interval = 120;
 
-int xpc_disengage_request_timelimit = XPC_DISENGAGE_REQUEST_DEFAULT_TIMELIMIT;
-static int xpc_disengage_request_min_timelimit;	/* = 0 */
-static int xpc_disengage_request_max_timelimit = 120;
+int xpc_disengage_timelimit = XPC_DISENGAGE_DEFAULT_TIMELIMIT;
+static int xpc_disengage_min_timelimit;	/* = 0 */
+static int xpc_disengage_max_timelimit = 120;
 
 static ctl_table xpc_sys_xpc_hb_dir[] = {
 	{
@@ -124,14 +124,14 @@ static ctl_table xpc_sys_xpc_dir[] = {
 	 .child = xpc_sys_xpc_hb_dir},
 	{
 	 .ctl_name = CTL_UNNUMBERED,
-	 .procname = "disengage_request_timelimit",
-	 .data = &xpc_disengage_request_timelimit,
+	 .procname = "disengage_timelimit",
+	 .data = &xpc_disengage_timelimit,
 	 .maxlen = sizeof(int),
 	 .mode = 0644,
 	 .proc_handler = &proc_dointvec_minmax,
 	 .strategy = &sysctl_intvec,
-	 .extra1 = &xpc_disengage_request_min_timelimit,
-	 .extra2 = &xpc_disengage_request_max_timelimit},
+	 .extra1 = &xpc_disengage_min_timelimit,
+	 .extra2 = &xpc_disengage_max_timelimit},
 	{}
 };
 static ctl_table xpc_sys_dir[] = {
@@ -144,8 +144,8 @@ static ctl_table xpc_sys_dir[] = {
 };
 static struct ctl_table_header *xpc_sysctl;
 
-/* non-zero if any remote partition disengage request was timed out */
-int xpc_disengage_request_timedout;
+/* non-zero if any remote partition disengage was timed out */
+int xpc_disengage_timedout;
 
 /* #of activate IRQs received */
 atomic_t xpc_activate_IRQ_rcvd = ATOMIC_INIT(0);
@@ -184,38 +184,36 @@ void (*xpc_online_heartbeat) (void);
 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_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_indicate_partition_engaged) (struct xpc_partition *part);
+int (*xpc_partition_engaged) (short partid);
+int (*xpc_any_partition_engaged) (void);
+void (*xpc_indicate_partition_disengaged) (struct xpc_partition *part);
+void (*xpc_assume_partition_disengaged) (short partid);
+
+void (*xpc_send_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 @@ enum xp_retval (*xpc_send_msg) (struct xpc_channel *ch, u32 flags,
 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 @@ xpc_activating(void *__partid)
 
 	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 @@ xpc_activate_partition(struct xpc_partition *part)
 	}
 }
 
-/*
- * 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 @@ xpc_kthread_waitmsgs(struct xpc_partition *part, struct xpc_channel *ch)
 	do {
 		/* deliver messages to their intended recipients */
 
-		while (ch->w_local_GP.get < ch->w_remote_GP.put &&
+		while (xpc_n_of_deliverable_msgs(ch) > 0 &&
 		       !(ch->flags & XPC_C_DISCONNECTING)) {
 			xpc_deliver_msg(ch);
 		}
@@ -632,7 +554,7 @@ xpc_kthread_waitmsgs(struct xpc_partition *part, struct xpc_channel *ch)
 			"wait_event_interruptible_exclusive()\n");
 
 		(void)wait_event_interruptible_exclusive(ch->idle_wq,
-				(ch->w_local_GP.get < ch->w_remote_GP.put ||
+				(xpc_n_of_deliverable_msgs(ch) > 0 ||
 				 (ch->flags & XPC_C_DISCONNECTING)));
 
 		atomic_dec(&ch->kthreads_idle);
@@ -677,7 +599,7 @@ xpc_kthread_start(void *args)
 			 * additional kthreads to help deliver them. We only
 			 * need one less than total #of messages to deliver.
 			 */
-			n_needed = ch->w_remote_GP.put - ch->w_local_GP.get - 1;
+			n_needed = xpc_n_of_deliverable_msgs(ch) - 1;
 			if (n_needed > 0 && !(ch->flags & XPC_C_DISCONNECTING))
 				xpc_activate_kthreads(ch, n_needed);
 
@@ -703,11 +625,9 @@ xpc_kthread_start(void *args)
 	}
 	spin_unlock_irqrestore(&ch->lock, irq_flags);
 
-	if (atomic_dec_return(&ch->kthreads_assigned) == 0) {
-		if (atomic_dec_return(&part->nchannels_engaged) == 0) {
-			xpc_mark_partition_disengaged(part);
-			xpc_IPI_send_disengage(part);
-		}
+	if (atomic_dec_return(&ch->kthreads_assigned) == 0 &&
+	    atomic_dec_return(&part->nchannels_engaged) == 0) {
+		xpc_indicate_partition_disengaged(part);
 	}
 
 	xpc_msgqueue_deref(ch);
@@ -758,9 +678,9 @@ xpc_create_kthreads(struct xpc_channel *ch, int needed,
 		} else if (ch->flags & XPC_C_DISCONNECTING) {
 			break;
 
-		} else if (atomic_inc_return(&ch->kthreads_assigned) == 1) {
-			if (atomic_inc_return(&part->nchannels_engaged) == 1)
-				xpc_mark_partition_engaged(part);
+		} else if (atomic_inc_return(&ch->kthreads_assigned) == 1 &&
+			   atomic_inc_return(&part->nchannels_engaged) == 1) {
+				xpc_indicate_partition_engaged(part);
 		}
 		(void)xpc_part_ref(part);
 		xpc_msgqueue_ref(ch);
@@ -782,8 +702,7 @@ xpc_create_kthreads(struct xpc_channel *ch, int needed,
 
 			if (atomic_dec_return(&ch->kthreads_assigned) == 0 &&
 			    atomic_dec_return(&part->nchannels_engaged) == 0) {
-				xpc_mark_partition_disengaged(part);
-				xpc_IPI_send_disengage(part);
+				xpc_indicate_partition_disengaged(part);
 			}
 			xpc_msgqueue_deref(ch);
 			xpc_part_deref(part);
@@ -862,7 +781,7 @@ xpc_do_exit(enum xp_retval reason)
 	short partid;
 	int active_part_count, printed_waiting_msg = 0;
 	struct xpc_partition *part;
-	unsigned long printmsg_time, disengage_request_timeout = 0;
+	unsigned long printmsg_time, disengage_timeout = 0;
 
 	/* a 'rmmod XPC' and a 'reboot' cannot both end up here together */
 	DBUG_ON(xpc_exiting == 1);
@@ -886,8 +805,8 @@ xpc_do_exit(enum xp_retval reason)
 
 	/* wait for all partitions to become inactive */
 
-	printmsg_time = jiffies + (XPC_DISENGAGE_PRINTMSG_INTERVAL * HZ);
-	xpc_disengage_request_timedout = 0;
+	printmsg_time = jiffies + (XPC_DEACTIVATE_PRINTMSG_INTERVAL * HZ);
+	xpc_disengage_timedout = 0;
 
 	do {
 		active_part_count = 0;
@@ -904,36 +823,32 @@ xpc_do_exit(enum xp_retval reason)
 
 			XPC_DEACTIVATE_PARTITION(part, reason);
 
-			if (part->disengage_request_timeout >
-			    disengage_request_timeout) {
-				disengage_request_timeout =
-				    part->disengage_request_timeout;
-			}
+			if (part->disengage_timeout > disengage_timeout)
+				disengage_timeout = part->disengage_timeout;
 		}
 
-		if (xpc_partition_engaged(-1UL)) {
+		if (xpc_any_partition_enga