Merge git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild-fixes

1 files changed, 165 insertions, 1420 deletions

diff --git a/drivers/misc/sgi-xp/xpc_channel.c b/drivers/misc/sgi-xp/xpc_channel.c
index 9c90c2d55c08..9cd2ebe2a3b6 100644
--- a/drivers/misc/sgi-xp/xpc_channel.c
+++ b/drivers/misc/sgi-xp/xpc_channel.c
@@ -14,536 +14,10 @@
  *
  */
 
-#include <linux/kernel.h>
-#include <linux/init.h>
-#include <linux/sched.h>
-#include <linux/cache.h>
-#include <linux/interrupt.h>
-#include <linux/mutex.h>
-#include <linux/completion.h>
-#include <asm/sn/bte.h>
-#include <asm/sn/sn_sal.h>
+#include <linux/device.h>
 #include "xpc.h"
 
 /*
- * Guarantee that the kzalloc'd memory is cacheline aligned.
- */
-static void *
-xpc_kzalloc_cacheline_aligned(size_t size, gfp_t flags, void **base)
-{
-	/* see if kzalloc will give us cachline aligned memory by default */
-	*base = kzalloc(size, flags);
-	if (*base == NULL)
-		return NULL;
-
-	if ((u64)*base == L1_CACHE_ALIGN((u64)*base))
-		return *base;
-
-	kfree(*base);
-
-	/* nope, we'll have to do it ourselves */
-	*base = kzalloc(size + L1_CACHE_BYTES, flags);
-	if (*base == NULL)
-		return NULL;
-
-	return (void *)L1_CACHE_ALIGN((u64)*base);
-}
-
-/*
- * Set up the initial values for the XPartition Communication channels.
- */
-static void
-xpc_initialize_channels(struct xpc_partition *part, short partid)
-{
-	int ch_number;
-	struct xpc_channel *ch;
-
-	for (ch_number = 0; ch_number < part->nchannels; ch_number++) {
-		ch = &part->channels[ch_number];
-
-		ch->partid = partid;
-		ch->number = ch_number;
-		ch->flags = XPC_C_DISCONNECTED;
-
-		ch->local_GP = &part->local_GPs[ch_number];
-		ch->local_openclose_args =
-		    &part->local_openclose_args[ch_number];
-
-		atomic_set(&ch->kthreads_assigned, 0);
-		atomic_set(&ch->kthreads_idle, 0);
-		atomic_set(&ch->kthreads_active, 0);
-
-		atomic_set(&ch->references, 0);
-		atomic_set(&ch->n_to_notify, 0);
-
-		spin_lock_init(&ch->lock);
-		mutex_init(&ch->msg_to_pull_mutex);
-		init_completion(&ch->wdisconnect_wait);
-
-		atomic_set(&ch->n_on_msg_allocate_wq, 0);
-		init_waitqueue_head(&ch->msg_allocate_wq);
-		init_waitqueue_head(&ch->idle_wq);
-	}
-}
-
-/*
- * Setup the infrastructure necessary to support XPartition Communication
- * between the specified remote partition and the local one.
- */
-enum xp_retval
-xpc_setup_infrastructure(struct xpc_partition *part)
-{
-	int ret, cpuid;
-	struct timer_list *timer;
-	short partid = XPC_PARTID(part);
-
-	/*
-	 * Zero out MOST of the entry for this partition. Only the fields
-	 * starting with `nchannels' will be zeroed. The preceding fields must
-	 * remain `viable' across partition ups and downs, since they may be
-	 * referenced during this memset() operation.
-	 */
-	memset(&part->nchannels, 0, sizeof(struct xpc_partition) -
-	       offsetof(struct xpc_partition, nchannels));
-
-	/*
-	 * Allocate all of the channel structures as a contiguous chunk of
-	 * memory.
-	 */
-	part->channels = kzalloc(sizeof(struct xpc_channel) * XPC_NCHANNELS,
-				 GFP_KERNEL);
-	if (part->channels == NULL) {
-		dev_err(xpc_chan, "can't get memory for channels\n");
-		return xpNoMemory;
-	}
-
-	part->nchannels = XPC_NCHANNELS;
-
-	/* 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) {
-		kfree(part->channels);
-		part->channels = NULL;
-		dev_err(xpc_chan, "can't get memory for local get/put "
-			"values\n");
-		return xpNoMemory;
-	}
-
-	part->remote_GPs = xpc_kzalloc_cacheline_aligned(XPC_GP_SIZE,
-							 GFP_KERNEL,
-							 &part->
-							 remote_GPs_base);
-	if (part->remote_GPs == NULL) {
-		dev_err(xpc_chan, "can't get memory for remote get/put "
-			"values\n");
-		kfree(part->local_GPs_base);
-		part->local_GPs = NULL;
-		kfree(part->channels);
-		part->channels = NULL;
-		return xpNoMemory;
-	}
-
-	/* allocate all the required open and close args */
-
-	part->local_openclose_args =
-	    xpc_kzalloc_cacheline_aligned(XPC_OPENCLOSE_ARGS_SIZE, GFP_KERNEL,
-					  &part->local_openclose_args_base);
-	if (part->local_openclose_args == NULL) {
-		dev_err(xpc_chan, "can't get memory for local connect args\n");
-		kfree(part->remote_GPs_base);
-		part->remote_GPs = NULL;
-		kfree(part->local_GPs_base);
-		part->local_GPs = NULL;
-		kfree(part->channels);
-		part->channels = NULL;
-		return xpNoMemory;
-	}
-
-	part->remote_openclose_args =
-	    xpc_kzalloc_cacheline_aligned(XPC_OPENCLOSE_ARGS_SIZE, GFP_KERNEL,
-					  &part->remote_openclose_args_base);
-	if (part->remote_openclose_args == NULL) {
-		dev_err(xpc_chan, "can't get memory for remote connect args\n");
-		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->channels);
-		part->channels = NULL;
-		return xpNoMemory;
-	}
-
-	xpc_initialize_channels(part, partid);
-
-	atomic_set(&part->nchannels_active, 0);
-	atomic_set(&part->nchannels_engaged, 0);
-
-	/* local_IPI_amo were set to 0 by an earlier memset() */
-
-	/* Initialize this partitions AMO_t structure */
-	part->local_IPI_amo_va = xpc_IPI_init(partid);
-
-	spin_lock_init(&part->IPI_lock);
-
-	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);
-	if (ret != 0) {
-		dev_err(xpc_chan, "can't register NOTIFY IRQ handler, "
-			"errno=%d\n", -ret);
-		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->channels);
-		part->channels = NULL;
-		return xpLackOfResources;
-	}
-
-	/* Setup a timer to check for dropped IPIs */
-	timer = &part->dropped_IPI_timer;
-	init_timer(timer);
-	timer->function = (void (*)(unsigned long))xpc_dropped_IPI_check;
-	timer->data = (unsigned long)part;
-	timer->expires = jiffies + XPC_P_DROPPED_IPI_WAIT;
-	add_timer(timer);
-
-	/*
-	 * With the setting of the partition setup_state to XPC_P_SETUP, we're
-	 * declaring that this partition is ready to go.
-	 */
-	part->setup_state = XPC_P_SETUP;
-
-	/*
-	 * Setup the per partition specific variables required by the
-	 * remote partition to establish channel connections with us.
-	 *
-	 * The setting of the magic # indicates that these per partition
-	 * specific variables are ready to be used.
-	 */
-	xpc_vars_part[partid].GPs_pa = __pa(part->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);
-	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);
-	xpc_vars_part[partid].nchannels = part->nchannels;
-	xpc_vars_part[partid].magic = XPC_VP_MAGIC1;
-
-	return xpSuccess;
-}
-
-/*
- * Create a wrapper that hides the underlying mechanism for pulling a cacheline
- * (or multiple cachelines) from a remote partition.
- *
- * src must be a cacheline aligned physical address on the remote partition.
- * dst must be a cacheline aligned virtual address on this partition.
- * cnt must be an cacheline sized
- */
-static enum xp_retval
-xpc_pull_remote_cachelines(struct xpc_partition *part, void *dst,
-			   const void *src, size_t cnt)
-{
-	bte_result_t bte_ret;
-
-	DBUG_ON((u64)src != L1_CACHE_ALIGN((u64)src));
-	DBUG_ON((u64)dst != L1_CACHE_ALIGN((u64)dst));
-	DBUG_ON(cnt != L1_CACHE_ALIGN(cnt));
-
-	if (part->act_state == XPC_P_DEACTIVATING)
-		return part->reason;
-
-	bte_ret = xp_bte_copy((u64)src, (u64)dst, (u64)cnt,
-			      (BTE_NORMAL | BTE_WACQUIRE), NULL);
-	if (bte_ret == BTE_SUCCESS)
-		return xpSuccess;
-
-	dev_dbg(xpc_chan, "xp_bte_copy() from partition %d failed, ret=%d\n",
-		XPC_PARTID(part), bte_ret);
-
-	return xpc_map_bte_errors(bte_ret);
-}
-
-/*
- * Pull the remote per partition specific variables from the specified
- * partition.
- */
-enum xp_retval
-xpc_pull_remote_vars_part(struct xpc_partition *part)
-{
-	u8 buffer[L1_CACHE_BYTES * 2];
-	struct xpc_vars_part *pulled_entry_cacheline =
-	    (struct xpc_vars_part *)L1_CACHE_ALIGN((u64)buffer);
-	struct xpc_vars_part *pulled_entry;
-	u64 remote_entry_cacheline_pa, remote_entry_pa;
-	short partid = XPC_PARTID(part);
-	enum xp_retval ret;
-
-	/* pull the cacheline that contains the variables we're interested in */
-
-	DBUG_ON(part->remote_vars_part_pa !=
-		L1_CACHE_ALIGN(part->remote_vars_part_pa));
-	DBUG_ON(sizeof(struct xpc_vars_part) != L1_CACHE_BYTES / 2);
-
-	remote_entry_pa = part->remote_vars_part_pa +
-	    sn_partition_id * sizeof(struct xpc_vars_part);
-
-	remote_entry_cacheline_pa = (remote_entry_pa & ~(L1_CACHE_BYTES - 1));
-
-	pulled_entry = (struct xpc_vars_part *)((u64)pulled_entry_cacheline +
-						(remote_entry_pa &
-						 (L1_CACHE_BYTES - 1)));
-
-	ret = xpc_pull_remote_cachelines(part, pulled_entry_cacheline,
-					 (void *)remote_entry_cacheline_pa,
-					 L1_CACHE_BYTES);
-	if (ret != xpSuccess) {
-		dev_dbg(xpc_chan, "failed to pull XPC vars_part from "
-			"partition %d, ret=%d\n", partid, ret);
-		return ret;
-	}
-
-	/* see if they've been set up yet */
-
-	if (pulled_entry->magic != XPC_VP_MAGIC1 &&
-	    pulled_entry->magic != XPC_VP_MAGIC2) {
-
-		if (pulled_entry->magic != 0) {
-			dev_dbg(xpc_chan, "partition %d's XPC vars_part for "
-				"partition %d has bad magic value (=0x%lx)\n",
-				partid, sn_partition_id, pulled_entry->magic);
-			return xpBadMagic;
-		}
-
-		/* they've not been initialized yet */
-		return xpRetry;
-	}
-
-	if (xpc_vars_part[partid].magic == XPC_VP_MAGIC1) {
-
-		/* validate the variables */
-
-		if (pulled_entry->GPs_pa == 0 ||
-		    pulled_entry->openclose_args_pa == 0 ||
-		    pulled_entry->IPI_amo_pa == 0) {
-
-			dev_err(xpc_chan, "partition %d's XPC vars_part for "
-				"partition %d are not valid\n", partid,
-				sn_partition_id);
-			return xpInvalidAddress;
-		}
-
-		/* the variables we imported look to be valid */
-
-		part->remote_GPs_pa = pulled_entry->GPs_pa;
-		part->remote_openclose_args_pa =
-		    pulled_entry->openclose_args_pa;
-		part->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;
-
-		if (part->nchannels > pulled_entry->nchannels)
-			part->nchannels = pulled_entry->nchannels;
-
-		/* let the other side know that we've pulled their variables */
-
-		xpc_vars_part[partid].magic = XPC_VP_MAGIC2;
-	}
-
-	if (pulled_entry->magic == XPC_VP_MAGIC1)
-		return xpRetry;
-
-	return xpSuccess;
-}
-
-/*
- * Get the IPI flags and pull the openclose args and/or remote GPs as needed.
- */
-static u64
-xpc_get_IPI_flags(struct xpc_partition *part)
-{
-	unsigned long irq_flags;
-	u64 IPI_amo;
-	enum xp_retval ret;
-
-	/*
-	 * See if there are any IPI flags to be handled.
-	 */
-
-	spin_lock_irqsave(&part->IPI_lock, irq_flags);
-	IPI_amo = part->local_IPI_amo;
-	if (IPI_amo != 0)
-		part->local_IPI_amo = 0;
-
-	spin_unlock_irqrestore(&part->IPI_lock, irq_flags);
-
-	if (XPC_ANY_OPENCLOSE_IPI_FLAGS_SET(IPI_amo)) {
-		ret = xpc_pull_remote_cachelines(part,
-						 part->remote_openclose_args,
-						 (void *)part->
-						 remote_openclose_args_pa,
-						 XPC_OPENCLOSE_ARGS_SIZE);
-		if (ret != xpSuccess) {
-			XPC_DEACTIVATE_PARTITION(part, ret);
-
-			dev_dbg(xpc_chan, "failed to pull openclose args from "
-				"partition %d, ret=%d\n", XPC_PARTID(part),
-				ret);
-
-			/* don't bother processing IPIs anymore */
-			IPI_amo = 0;
-		}
-	}
-
-	if (XPC_ANY_MSG_IPI_FLAGS_SET(IPI_amo)) {
-		ret = xpc_pull_remote_cachelines(part, part->remote_GPs,
-						 (void *)part->remote_GPs_pa,
-						 XPC_GP_SIZE);
-		if (ret != xpSuccess) {
-			XPC_DEACTIVATE_PARTITION(part, ret);
-
-			dev_dbg(xpc_chan, "failed to pull GPs from partition "
-				"%d, ret=%d\n", XPC_PARTID(part), ret);
-
-			/* don't bother processing IPIs anymore */
-			IPI_amo = 0;
-		}
-	}
-
-	return IPI_amo;
-}
-
-/*
- * Allocate the local message queue and the notify queue.
- */
-static enum xp_retval
-xpc_allocate_local_msgqueue(struct xpc_channel *ch)
-{
-	unsigned long irq_flags;
-	int nentries;
-	size_t nbytes;
-
-	for (nentries = ch->local_nentries; nentries > 0; nentries--) {
-
-		nbytes = nentries * ch->msg_size;
-		ch->local_msgqueue = xpc_kzalloc_cacheline_aligned(nbytes,
-								   GFP_KERNEL,
-						      &ch->local_msgqueue_base);
-		if (ch->local_msgqueue == NULL)
-			continue;
-
-		nbytes = nentries * sizeof(struct xpc_notify);
-		ch->notify_queue = kzalloc(nbytes, GFP_KERNEL);
-		if (ch->notify_queue == NULL) {
-			kfree(ch->local_msgqueue_base);
-			ch->local_msgqueue = NULL;
-			continue;
-		}
-
-		spin_lock_irqsave(&ch->lock, irq_flags);
-		if (nentries < ch->local_nentries) {
-			dev_dbg(xpc_chan, "nentries=%d local_nentries=%d, "
-				"partid=%d, channel=%d\n", nentries,
-				ch->local_nentries, ch->partid, ch->number);
-
-			ch->local_nentries = nentries;
-		}
-		spin_unlock_irqrestore(&ch->lock, irq_flags);
-		return xpSuccess;
-	}
-
-	dev_dbg(xpc_chan, "can't get memory for local message queue and notify "
-		"queue, partid=%d, channel=%d\n", ch->partid, ch->number);
-	return xpNoMemory;
-}
-
-/*
- * Allocate the cached remote message queue.
- */
-static enum xp_retval
-xpc_allocate_remote_msgqueue(struct xpc_channel *ch)
-{
-	unsigned long irq_flags;
-	int nentries;
-	size_t nbytes;
-
-	DBUG_ON(ch->remote_nentries <= 0);
-
-	for (nentries = ch->remote_nentries; nentries > 0; nentries--) {
-
-		nbytes = nentries * ch->msg_size;
-		ch->remote_msgqueue = xpc_kzalloc_cacheline_aligned(nbytes,
-								    GFP_KERNEL,
-						     &ch->remote_msgqueue_base);
-		if (ch->remote_msgqueue == NULL)
-			continue;
-
-		spin_lock_irqsave(&ch->lock, irq_flags);
-		if (nentries < ch->remote_nentries) {
-			dev_dbg(xpc_chan, "nentries=%d remote_nentries=%d, "
-				"partid=%d, channel=%d\n", nentries,
-				ch->remote_nentries, ch->partid, ch->number);
-
-			ch->remote_nentries = nentries;
-		}
-		spin_unlock_irqrestore(&ch->lock, irq_flags);
-		return xpSuccess;
-	}
-
-	dev_dbg(xpc_chan, "can't get memory for cached remote message queue, "
-		"partid=%d, channel=%d\n", ch->partid, ch->number);
-	return xpNoMemory;
-}
-
-/*
- * Allocate message queues and other stuff associated with a channel.
- *
- * Note: Assumes all of the channel sizes are filled in.
- */
-static enum xp_retval
-xpc_allocate_msgqueues(struct xpc_channel *ch)
-{
-	unsigned long irq_flags;
-	enum xp_retval ret;
-
-	DBUG_ON(ch->flags & XPC_C_SETUP);
-
-	ret = xpc_allocate_local_msgqueue(ch);
-	if (ret != xpSuccess)
-		return ret;
-
-	ret = xpc_allocate_remote_msgqueue(ch);
-	if (ret != xpSuccess) {
-		kfree(ch->local_msgqueue_base);
-		ch->local_msgqueue = NULL;
-		kfree(ch->notify_queue);
-		ch->notify_queue = NULL;
-		return ret;
-	}
-
-	spin_lock_irqsave(&ch->lock, irq_flags);
-	ch->flags |= XPC_C_SETUP;
-	spin_unlock_irqrestore(&ch->lock, irq_flags);
-
-	return xpSuccess;
-}
-
-/*
  * Process a connect message from a remote partition.
  *
  * Note: xpc_process_connect() is expecting to be called with the
@@ -565,30 +39,29 @@ xpc_process_connect(struct xpc_channel *ch, unsigned long *irq_flags)
 
 	if (!(ch->flags & XPC_C_SETUP)) {
 		spin_unlock_irqrestore(&ch->lock, *irq_flags);
-		ret = xpc_allocate_msgqueues(ch);
+		ret = xpc_setup_msg_structures(ch);
 		spin_lock_irqsave(&ch->lock, *irq_flags);
 
 		if (ret != xpSuccess)
 			XPC_DISCONNECT_CHANNEL(ch, ret, irq_flags);
 
+		ch->flags |= XPC_C_SETUP;
+
 		if (ch->flags & (XPC_C_CONNECTED | XPC_C_DISCONNECTING))
 			return;
 
-		DBUG_ON(!(ch->flags & XPC_C_SETUP));
 		DBUG_ON(ch->local_msgqueue == NULL);
 		DBUG_ON(ch->remote_msgqueue == NULL);
 	}
 
 	if (!(ch->flags & XPC_C_OPENREPLY)) {
 		ch->flags |= XPC_C_OPENREPLY;
-		xpc_IPI_send_openreply(ch, irq_flags);
+		xpc_send_chctl_openreply(ch, irq_flags);
 	}
 
 	if (!(ch->flags & XPC_C_ROPENREPLY))
 		return;
 
-	DBUG_ON(ch->remote_msgqueue_pa == 0);
-
 	ch->flags = (XPC_C_CONNECTED | XPC_C_SETUP);	/* clear all else */
 
 	dev_info(xpc_chan, "channel %d to partition %d connected\n",
@@ -600,99 +73,6 @@ 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.
- *
- * Note: ch->reason and ch->reason_line are left set for debugging purposes,
- * they're cleared when XPC_C_DISCONNECTED is cleared.
- */
-static void
-xpc_free_msgqueues(struct xpc_channel *ch)
-{
-	DBUG_ON(!spin_is_locked(&ch->lock));
-	DBUG_ON(atomic_read(&ch->n_to_notify) != 0);
-
-	ch->remote_msgqueue_pa = 0;
-	ch->func = NULL;
-	ch->key = NULL;
-	ch->msg_size = 0;
-	ch->local_nentries = 0;
-	ch->remote_nentries = 0;
-	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;
-
-	if (ch->flags & XPC_C_SETUP) {
-		ch->flags &= ~XPC_C_SETUP;
-
-		dev_dbg(xpc_chan, "ch->flags=0x%x, partid=%d, channel=%d\n",
-			ch->flags, ch->partid, ch->number);
-
-		kfree(ch->local_msgqueue_base);
-		ch->local_msgqueue = NULL;
-		kfree(ch->remote_msgqueue_base);
-		ch->remote_msgqueue = NULL;
-		kfree(ch->notify_queue);
-		ch->notify_queue = NULL;
-	}
-}
-
-/*
  * spin_lock_irqsave() is expected to be held on entry.
  */
 static void
@@ -717,9 +97,9 @@ xpc_process_disconnect(struct xpc_channel *ch, unsigned long *irq_flags)
 	DBUG_ON((ch->flags & XPC_C_CONNECTEDCALLOUT_MADE) &&
 		!(ch->flags & XPC_C_DISCONNECTINGCALLOUT_MADE));
 
-	if (part->act_state == XPC_P_DEACTIVATING) {
+	if (part->act_state == XPC_P_AS_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 {
@@ -731,7 +111,7 @@ 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_chctl_closereply(ch, irq_flags);
 		}
 
 		if (!(ch->flags & XPC_C_RCLOSEREPLY))
@@ -740,8 +120,8 @@ 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);
+		/* we do callout while holding ch->lock, callout can't block */
+		xpc_notify_senders_of_disconnect(ch);
 	}
 
 	/* both sides are disconnected now */
@@ -752,10 +132,24 @@ xpc_process_disconnect(struct xpc_channel *ch, unsigned long *irq_flags)
 		spin_lock_irqsave(&ch->lock, *irq_flags);
 	}
 
+	DBUG_ON(atomic_read(&ch->n_to_notify) != 0);
+
 	/* it's now safe to free the channel's message queues */
-	xpc_free_msgqueues(ch);
+	xpc_teardown_msg_structures(ch);
 
-	/* mark disconnected, clear all other flags except XPC_C_WDISCONNECT */
+	ch->func = NULL;
+	ch->key = NULL;
+	ch->entry_size = 0;
+	ch->local_nentries = 0;
+	ch->remote_nentries = 0;
+	ch->kthreads_assigned_limit = 0;
+	ch->kthreads_idle_limit = 0;
+
+	/*
+	 * Mark the channel disconnected and clear all other flags, including
+	 * XPC_C_SETUP (because of call to xpc_teardown_msg_structures()) but
+	 * not including XPC_C_WDISCONNECT (if it was set).
+	 */
 	ch->flags = (XPC_C_DISCONNECTED | (ch->flags & XPC_C_WDISCONNECT));
 
 	atomic_dec(&part->nchannels_active);
@@ -768,15 +162,15 @@ xpc_process_disconnect(struct xpc_channel *ch, unsigned long *irq_flags)
 	if (ch->flags & XPC_C_WDISCONNECT) {
 		/* we won't lose the CPU since we're holding ch->lock */
 		complete(&ch->wdisconnect_wait);
-	} else if (ch->delayed_IPI_flags) {
-		if (part->act_state != XPC_P_DEACTIVATING) {
-			/* time to take action on any delayed IPI flags */
-			spin_lock(&part->IPI_lock);
-			XPC_SET_IPI_FLAGS(part->local_IPI_amo, ch->number,
-					  ch->delayed_IPI_flags);
-			spin_unlock(&part->IPI_lock);
+	} else if (ch->delayed_chctl_flags) {
+		if (part->act_state != XPC_P_AS_DEACTIVATING) {
+			/* time to take action on any delayed chctl flags */
+			spin_lock(&part->chctl_lock);
+			part->chctl.flags[ch->number] |=
+			    ch->delayed_chctl_flags;
+			spin_unlock(&part->chctl_lock);
 		}
-		ch->delayed_IPI_flags = 0;
+		ch->delayed_chctl_flags = 0;
 	}
 }
 
@@ -784,8 +178,8 @@ xpc_process_disconnect(struct xpc_channel *ch, unsigned long *irq_flags)
  * Process a change in the channel's remote connection state.
  */
 static void
-xpc_process_openclose_IPI(struct xpc_partition *part, int ch_number,
-			  u8 IPI_flags)
+xpc_process_openclose_chctl_flags(struct xpc_partition *part, int ch_number,
+				  u8 chctl_flags)
 {
 	unsigned long irq_flags;
 	struct xpc_openclose_args *args =
@@ -800,24 +194,24 @@ again:
 	if ((ch->flags & XPC_C_DISCONNECTED) &&
 	    (ch->flags & XPC_C_WDISCONNECT)) {
 		/*
-		 * Delay processing IPI flags until thread waiting disconnect
+		 * Delay processing chctl flags until thread waiting disconnect
 		 * has had a chance to see that the channel is disconnected.
 		 */
-		ch->delayed_IPI_flags |= IPI_flags;
+		ch->delayed_chctl_flags |= chctl_flags;
 		spin_unlock_irqrestore(&ch->lock, irq_flags);
 		return;
 	}
 
-	if (IPI_flags & XPC_IPI_CLOSEREQUEST) {
+	if (chctl_flags & XPC_CHCTL_CLOSEREQUEST) {
 
-		dev_dbg(xpc_chan, "XPC_IPI_CLOSEREQUEST (reason=%d) received "
+		dev_dbg(xpc_chan, "XPC_CHCTL_CLOSEREQUEST (reason=%d) received "
 			"from partid=%d, channel=%d\n", args->reason,
 			ch->partid, ch->number);
 
 		/*
 		 * If RCLOSEREQUEST is set, we're probably waiting for
 		 * RCLOSEREPLY. We should find it and a ROPENREQUEST packed
-		 * with this RCLOSEREQUEST in the IPI_flags.
+		 * with this RCLOSEREQUEST in the chctl_flags.
 		 */
 
 		if (ch->flags & XPC_C_RCLOSEREQUEST) {
@@ -826,8 +220,8 @@ again:
 			DBUG_ON(!(ch->flags & XPC_C_CLOSEREPLY));
 			DBUG_ON(ch->flags & XPC_C_RCLOSEREPLY);
 
-			DBUG_ON(!(IPI_flags & XPC_IPI_CLOSEREPLY));
-			IPI_flags &= ~XPC_IPI_CLOSEREPLY;
+			DBUG_ON(!(chctl_flags & XPC_CHCTL_CLOSEREPLY));
+			chctl_flags &= ~XPC_CHCTL_CLOSEREPLY;
 			ch->flags |= XPC_C_RCLOSEREPLY;
 
 			/* both sides have finished disconnecting */
@@ -837,17 +231,15 @@ again:
 		}
 
 		if (ch->flags & XPC_C_DISCONNECTED) {
-			if (!(IPI_flags & XPC_IPI_OPENREQUEST)) {
-				if ((XPC_GET_IPI_FLAGS(part->local_IPI_amo,
-						       ch_number) &
-				     XPC_IPI_OPENREQUEST)) {
-
-					DBUG_ON(ch->delayed_IPI_flags != 0);
-					spin_lock(&part->IPI_lock);
-					XPC_SET_IPI_FLAGS(part->local_IPI_amo,
-							  ch_number,
-							  XPC_IPI_CLOSEREQUEST);
-					spin_unlock(&part->IPI_lock);
+			if (!(chctl_flags & XPC_CHCTL_OPENREQUEST)) {
+				if (part->chctl.flags[ch_number] &
+				    XPC_CHCTL_OPENREQUEST) {
+
+					DBUG_ON(ch->delayed_chctl_flags != 0);
+					spin_lock(&part->chctl_lock);
+					part->chctl.flags[ch_number] |=
+					    XPC_CHCTL_CLOSEREQUEST;
+					spin_unlock(&part->chctl_lock);
 				}
 				spin_unlock_irqrestore(&ch->lock, irq_flags);
 				return;
@@ -860,7 +252,7 @@ again:
 			ch->flags |= (XPC_C_CONNECTING | XPC_C_ROPENREQUEST);
 		}
 
-		IPI_flags &= ~(XPC_IPI_OPENREQUEST | XPC_IPI_OPENREPLY);
+		chctl_flags &= ~(XPC_CHCTL_OPENREQUEST | XPC_CHCTL_OPENREPLY);
 
 		/*
 		 * The meaningful CLOSEREQUEST connection state fields are:
@@ -878,7 +270,7 @@ again:
 
 			XPC_DISCONNECT_CHANNEL(ch, reason, &irq_flags);
 
-			DBUG_ON(IPI_flags & XPC_IPI_CLOSEREPLY);
+			DBUG_ON(chctl_flags & XPC_CHCTL_CLOSEREPLY);
 			spin_unlock_irqrestore(&ch->lock, irq_flags);
 			return;
 		}
@@ -886,13 +278,13 @@ again:
 		xpc_process_disconnect(ch, &irq_flags);
 	}
 
-	if (IPI_flags & XPC_IPI_CLOSEREPLY) {
+	if (chctl_flags & XPC_CHCTL_CLOSEREPLY) {
 
-		dev_dbg(xpc_chan, "XPC_IPI_CLOSEREPLY received from partid=%d,"
-			" channel=%d\n", ch->partid, ch->number);
+		dev_dbg(xpc_chan, "XPC_CHCTL_CLOSEREPLY received from partid="
+			"%d, channel=%d\n", ch->partid, ch->number);
 
 		if (ch->flags & XPC_C_DISCONNECTED) {
-			DBUG_ON(part->act_state != XPC_P_DEACTIVATING);
+			DBUG_ON(part->act_state != XPC_P_AS_DEACTIVATING);
 			spin_unlock_irqrestore(&ch->lock, irq_flags);
 			return;
 		}
@@ -900,15 +292,14 @@ again:
 		DBUG_ON(!(ch->flags & XPC_C_CLOSEREQUEST));
 
 		if (!(ch->flags & XPC_C_RCLOSEREQUEST)) {
-			if ((XPC_GET_IPI_FLAGS(part->local_IPI_amo, ch_number)
-			     & XPC_IPI_CLOSEREQUEST)) {
-
-				DBUG_ON(ch->delayed_IPI_flags != 0);
-				spin_lock(&part->IPI_lock);
-				XPC_SET_IPI_FLAGS(part->local_IPI_amo,
-						  ch_number,
-						  XPC_IPI_CLOSEREPLY);
-				spin_unlock(&part->IPI_lock);
+			if (part->chctl.flags[ch_number] &
+			    XPC_CHCTL_CLOSEREQUEST) {
+
+				DBUG_ON(ch->delayed_chctl_flags != 0);
+				spin_lock(&part->chctl_lock);
+				part->chctl.flags[ch_number] |=
+				    XPC_CHCTL_CLOSEREPLY;
+				spin_unlock(&part->chctl_lock);
 			}
 			spin_unlock_irqrestore(&ch->lock, irq_flags);
 			return;
@@ -922,21 +313,21 @@ again:
 		}
 	}
 
-	if (IPI_flags & XPC_IPI_OPENREQUEST) {
+	if (chctl_flags & XPC_CHCTL_OPENREQUEST) {
 
-		dev_dbg(xpc_chan, "XPC_IPI_OPENREQUEST (msg_size=%d, "
+		dev_dbg(xpc_chan, "XPC_CHCTL_OPENREQUEST (entry_size=%d, "
 			"local_nentries=%d) received from partid=%d, "
-			"channel=%d\n", args->msg_size, args->local_nentries,
+			"channel=%d\n", args->entry_size, args->local_nentries,
 			ch->partid, ch->number);
 
-		if (part->act_state == XPC_P_DEACTIVATING ||
+		if (part->act_state == XPC_P_AS_DEACTIVATING ||
 		    (ch->flags & XPC_C_ROPENREQUEST)) {
 			spin_unlock_irqrestore(&ch->lock, irq_flags);
 			return;
 		}
 
 		if (ch->flags & (XPC_C_DISCONNECTING | XPC_C_WDISCONNECT)) {
-			ch->delayed_IPI_flags |= XPC_IPI_OPENREQUEST;
+			ch->delayed_chctl_flags |= XPC_CHCTL_OPENREQUEST;
 			spin_unlock_irqrestore(&ch->lock, irq_flags);
 			return;
 		}
@@ -947,10 +338,10 @@ again:
 
 		/*
 		 * The meaningful OPENREQUEST connection state fields are:
-		 *      msg_size = size of channel's messages in bytes
+		 *      entry_size = size of channel's messages in bytes
 		 *      local_nentries = remote partition's local_nentries
 		 */
-		if (args->msg_size == 0 || args->local_nentries == 0) {
+		if (args->entry_size == 0 || args->local_nentries == 0) {
 			/* assume OPENREQUEST was delayed by mistake */
 			spin_unlock_irqrestore(&ch->lock, irq_flags);
 			return;
@@ -960,14 +351,14 @@ again:
 		ch->remote_nentries = args->local_nentries;
 
 		if (ch->flags & XPC_C_OPENREQUEST) {
-			if (args->msg_size != ch->msg_size) {
+			if (args->entry_size != ch->entry_size) {
 				XPC_DISCONNECT_CHANNEL(ch, xpUnequalMsgSizes,
 						       &irq_flags);
 				spin_unlock_irqrestore(&ch->lock, irq_flags);
 				return;
 			}
 		} else {
-			ch->msg_size = args->msg_size;
+			ch->entry_size = args->entry_size;
 
 			XPC_SET_REASON(ch, 0, 0);
 			ch->flags &= ~XPC_C_DISCONNECTED;
@@ -978,13 +369,13 @@ again:
 		xpc_process_connect(ch, &irq_flags);
 	}
 
-	if (IPI_flags & XPC_IPI_OPENREPLY) {
+	if (chctl_flags & XPC_CHCTL_OPENREPLY) {
 
-		dev_dbg(xpc_chan, "XPC_IPI_OPENREPLY (local_msgqueue_pa=0x%lx, "
-			"local_nentries=%d, remote_nentries=%d) received from "
-			"partid=%d, channel=%d\n", args->local_msgqueue_pa,
-			args->local_nentries, args->remote_nentries,
-			ch->partid, ch->number);
+		dev_dbg(xpc_chan, "XPC_CHCTL_OPENREPLY (local_msgqueue_pa="
+			"0x%lx, local_nentries=%d, remote_nentries=%d) "
+			"received from partid=%d, channel=%d\n",
+			args->local_msgqueue_pa, args->local_nentries,
+			args->remote_nentries, ch->partid, ch->number);
 
 		if (ch->flags & (XPC_C_DISCONNECTING | XPC_C_DISCONNECTED)) {
 			spin_unlock_irqrestore(&ch->lock, irq_flags);
@@ -1012,10 +403,10 @@ again:
 		DBUG_ON(args->remote_nentries == 0);
 
 		ch->flags |= XPC_C_ROPENREPLY;
-		ch->remote_msgqueue_pa = args->local_msgqueue_pa;
+		xpc_save_remote_msgqueue_pa(ch, args->local_msgqueue_pa);
 
 		if (args->local_nentries < ch->remote_nentries) {
-			dev_dbg(xpc_chan, "XPC_IPI_OPENREPLY: new "
+			dev_dbg(xpc_chan, "XPC_CHCTL_OPENREPLY: new "
 				"remote_nentries=%d, old remote_nentries=%d, "
 				"partid=%d, channel=%d\n",
 				args->local_nentries, ch->remote_nentries,
@@ -1024,7 +415,7 @@ again:
 			ch->remote_nentries = args->local_nentries;
 		}
 		if (args->remote_nentries < ch->local_nentries) {
-			dev_dbg(xpc_chan, "XPC_IPI_OPENREPLY: new "
+			dev_dbg(xpc_chan, "XPC_CHCTL_OPENREPLY: new "
 				"local_nentries=%d, old local_nentries=%d, "
 				"partid=%d, channel=%d\n",
 				args->remote_nentries, ch->local_nentries,
@@ -1082,7 +473,7 @@ xpc_connect_channel(struct xpc_channel *ch)
 	ch->local_nentries = registration->nentries;
 
 	if (ch->flags & XPC_C_ROPENREQUEST) {
-		if (registration->msg_size != ch->msg_size) {
+		if (registration->entry_size != ch->entry_size) {
 			/* the local and remote sides aren't the same */
 
 			/*
@@ -1101,7 +492,7 @@ xpc_connect_channel(struct xpc_channel *ch)
 			return xpUnequalMsgSizes;
 		}
 	} else {
-		ch->msg_size = registration->msg_size;
+		ch->entry_size = registration->entry_size;
 
 		XPC_SET_REASON(ch, 0, 0);
 		ch->flags &= ~XPC_C_DISCONNECTED;
@@ -1114,7 +505,7 @@ 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_chctl_openrequest(ch, &irq_flags);
 
 	xpc_process_connect(ch, &irq_flags);
 
@@ -1123,152 +514,16 @@ 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)
+xpc_process_sent_chctl_flags(struct xpc_partition *part)
 {
 	unsigned long irq_flags;
-	u64 IPI_amo, IPI_flags;
+	union xpc_channel_ctl_flags chctl;
 	struct xpc_channel *ch;
 	int ch_number;
 	u32 ch_flags;
 
-	IPI_amo = xpc_get_IPI_flags(part);
+	chctl.all_flags = xpc_get_chctl_all_flags(part);
 
 	/*
 	 * Initiate channel connections for registered channels.
@@ -1281,14 +536,14 @@ xpc_process_channel_activity(struct xpc_partition *part)
 		ch = &part->channels[ch_number];
 
 		/*
-		 * Process any open or close related IPI flags, and then deal
+		 * Process any open or close related chctl flags, and then deal
 		 * with connecting or disconnecting the channel as required.
 		 */
 
-		IPI_flags = XPC_GET_IPI_FLAGS(IPI_amo, ch_number);
-
-		if (XPC_ANY_OPENCLOSE_IPI_FLAGS_SET(IPI_flags))
-			xpc_process_openclose_IPI(part, ch_number, IPI_flags);
+		if (chctl.flags[ch_number] & XPC_OPENCLOSE_CHCTL_FLAGS) {
+			xpc_process_openclose_chctl_flags(part, ch_number,
+							chctl.flags[ch_number]);
+		}
 
 		ch_flags = ch->flags;	/* need an atomic snapshot of flags */
 
@@ -1299,7 +554,7 @@ xpc_process_channel_activity(struct xpc_partition *part)
 			continue;
 		}
 
-		if (part->act_state == XPC_P_DEACTIVATING)
+		if (part->act_state == XPC_P_AS_DEACTIVATING)
 			continue;
 
 		if (!(ch_flags & XPC_C_CONNECTED)) {
@@ -1315,13 +570,13 @@ xpc_process_channel_activity(struct xpc_partition *part)
 		}
 
 		/*
-		 * Process any message related IPI flags, this may involve the
-		 * activation of kthreads to deliver any pending messages sent
-		 * from the other partition.
+		 * Process any message related chctl flags, this may involve
+		 * the activation of kthreads to deliver any pending messages
+		 * sent from the other partition.
 		 */
 
-		if (XPC_ANY_MSG_IPI_FLAGS_SET(IPI_flags))
-			xpc_process_msg_IPI(part, ch_number);
+		if (chctl.flags[ch_number] & XPC_MSG_CHCTL_FLAGS)
+			xpc_process_msg_chctl_flags(part, ch_number);
 	}
 }
 
@@ -1369,59 +624,6 @@ xpc_partition_going_down(struct xpc_partition *part, enum xp_retval reason)
 }
 
 /*
- * Teardown the infrastructure necessary to support XPartition Communication
- * between the specified remote partition and the local one.
- */
-void
-xpc_teardown_infrastructure(struct xpc_partition *part)
-{
-	short partid = XPC_PARTID(part);
-
-	/*
-	 * We start off by making this partition inaccessible to local
-	 * processes by marking it as no longer setup. Then we make it
-	 * inaccessible to remote processes by clearing the XPC per partition
-	 * specific variable's magic # (which indicates that these variables
-	 * are no longer valid) and by ignoring all XPC notify IPIs sent to
-	 * this partition.
-	 */
-
-	DBUG_ON(atomic_read(&part->nchannels_engaged) != 0);
-	DBUG_ON(atomic_read(&part->nchannels_active) != 0);
-	DBUG_ON(part->setup_state != XPC_P_SETUP);
-	part->setup_state = XPC_P_WTEARDOWN;
-
-	xpc_vars_part[partid].magic = 0;
-
-	free_irq(SGI_XPC_NOTIFY, (void *)(u64)partid);
-
-	/*
-	 * Before proceeding with the teardown we have to wait until all
-	 * existing references cease.
-	 */
-	wait_event(part->teardown_wq, (atomic_read(&part->references) == 0));
-
-	/* now we can begin tearing down the infrastructure */
-
-	part->setup_state = XPC_P_TORNDOWN;
-
-	/* in case we've still got outstanding timers registered... */
-	del_timer_sync(&part->dropped_IPI_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->channels);
-	part->channels = NULL;
-	part->local_IPI_amo_va = NULL;
-}
-
-/*
  * Called by XP at the time of channel connection registration to cause
  * XPC to establish connections to all currently active partitions.
  */
@@ -1432,9 +634,9 @@ xpc_initiate_connect(int ch_number)
 	struct xpc_partition *part;
 	struct xpc_channel *ch;
 
-	DBUG_ON(ch_number < 0 || ch_number >= XPC_NCHANNELS);
+	DBUG_ON(ch_number < 0 || ch_number >= XPC_MAX_NCHANNELS);
 
-	for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) {
+	for (partid = 0; partid < xp_max_npartitions; partid++) {
 		part = &xpc_partitions[partid];
 
 		if (xpc_part_ref(part)) {
@@ -1488,10 +690,10 @@ xpc_initiate_disconnect(int ch_number)
 	struct xpc_partition *part;
 	struct xpc_channel *ch;
 
-	DBUG_ON(ch_number < 0 || ch_number >= XPC_NCHANNELS);
+	DBUG_ON(ch_number < 0 || ch_number >= XPC_MAX_NCHANNELS);
 
 	/* initiate the channel disconnect for every active partition */
-	for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) {
+	for (partid = 0; partid < xp_max_npartitions; partid++) {
 		part = &xpc_partitions[partid];
 
 		if (xpc_part_ref(part)) {
@@ -1550,7 +752,7 @@ 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_chctl_closerequest(ch, irq_flags);
 
 	if (channel_was_connected)
 		ch->flags |= XPC_C_WASCONNECTED;
@@ -1598,7 +800,7 @@ xpc_disconnect_callout(struct xpc_channel *ch, enum xp_retval reason)
  * Wait for a message entry to become available for the specified channel,
  * but don't wait any longer than 1 jiffy.
  */
-static enum xp_retval
+enum xp_retval
 xpc_allocate_msg_wait(struct xpc_channel *ch)
 {
 	enum xp_retval ret;
@@ -1625,315 +827,54 @@ xpc_allocate_msg_wait(struct xpc_channel *ch)
 }
 
 /*
- * Allocate an entry for a message from the message queue associated with the
- * specified channel.
- */
-static enum xp_retval
-xpc_allocate_msg(struct xpc_channel *ch, u32 flags,
-		 struct xpc_msg **address_of_msg)
-{
-	struct xpc_msg *msg;
-	enum xp_retval ret;
-	s64 put;
-
-	/* this reference will be dropped in xpc_send_msg() */
-	xpc_msgqueue_ref(ch);
-
-	if (ch->flags & XPC_C_DISCONNECTING) {
-		xpc_msgqueue_deref(ch);
-		return ch->reason;
-	}
-	if (!(ch->flags & XPC_C_CONNECTED)) {
-		xpc_msgqueue_deref(ch);
-		return xpNotConnected;
-	}
-
-	/*
-	 * Get the next available message entry from the local message queue.
-	 * If none are available, we'll make sure that we grab the latest
-	 * GP values.
-	 */
-	ret = xpTimeout;
-
-	while (1) {
-
-		put = ch->w_local_GP.put;
-		rmb();	/* guarantee that .put loads before .get */
-		if (put - ch->w_remote_GP.get < ch->local_nentries) {
-
-			/* There are available message entries. We need to try
-			 * to secure one for ourselves. We'll do this by trying
-			 * to increment w_local_GP.put as long as someone else
-			 * doesn't beat us to it. If they do, we'll have to
-			 * try again.
-			 */
-			if (cmpxchg(&ch->w_local_GP.put, put, put + 1) == put) {
-				/* we got the entry referenced by put */
-				break;
-			}
-			continue;	/* try again */
-		}
-
-		/*
-		 * There aren't any available msg entries at this time.
-		 *
-		 * In waiting for a message entry to become available,
-		 * we set a timeout in case the other side is not
-		 * sending completion IPIs. This lets us fake an IPI
-		 * that will cause the IPI handler to fetch the latest
-		 * GP values as if an IPI was sent by the other side.
-		 */
-		if (ret == xpTimeout)
-			xpc_IPI_send_local_msgrequest(ch);
-
-		if (flags & XPC_NOWAIT) {
-			xpc_msgqueue_deref(ch);
-			return xpNoWait;
-		}
-
-		ret = xpc_allocate_msg_wait(ch);
-		if (ret != xpInterrupted && ret != xpTimeout) {
-			xpc_msgqueue_deref(ch);
-			return ret;
-		}
-	}
-
-	/* get the message's address and initialize it */
-	msg = (struct xpc_msg *)((u64)ch->local_msgqueue +
-				 (put % ch->local_nentries) * ch->msg_size);
-
-	DBUG_ON(msg->flags != 0);
-	msg->number = put;
-
-	dev_dbg(xpc_chan, "w_local_GP.put changed to %ld; msg=0x%p, "
-		"msg_number=%ld, partid=%d, channel=%d\n", put + 1,
-		(void *)msg, msg->number, ch->partid, ch->number);
-
-	*address_of_msg = msg;
-
-	return xpSuccess;
-}
-
-/*
- * Allocate an entry for a message from the message queue associated with the
- * specified channel. NOTE that this routine can sleep waiting for a message
- * entry to become available. To not sleep, pass in the XPC_NOWAIT flag.
+ * Send a message that contains the user's payload on the specified channel
+ * connected to the specified partition.
  *
- * Arguments:
+ * NOTE that this routine can sleep waiting for a message entry to become
+ * available. To not sleep, pass in the XPC_NOWAIT flag.
  *
- *	partid - ID of partition to which the channel is connected.
- *	ch_number - channel #.
- *	flags - see xpc.h for valid flags.
- *	payload - address of the allocated payload area pointer (filled in on
- * 	          return) in which the user-defined message is constructed.
- */
-enum xp_retval
-xpc_initiate_allocate(short partid, int ch_number, u32 flags, void **payload)
-{
-	struct xpc_partition *part = &xpc_partitions[partid];
-	enum xp_retval ret = xpUnknownReason;
-	struct xpc_msg *msg = NULL;
-
-	DBUG_ON(partid <= 0 || partid >= XP_MAX_PARTITIONS);
-	DBUG_ON(ch_number < 0 || ch_number >= part->nchannels);
-
-	*payload = NULL;
-
-	if (xpc_part_ref(part)) {
-		ret = xpc_allocate_msg(&part->channels[ch_number], flags, &msg);
-		xpc_part_deref(part);
-
-		if (msg != NULL)
-			*payload = &msg->payload;
-	}
-
-	return ret;
-}
-
-/*
- * Now we actually send the messages that are ready to be sent by advancing
- * the local message queue's Put value and then send an IPI to the recipient
- * partition.
- */
-static void
-xpc_send_msgs(struct xpc_channel *ch, s64 initial_put)
-{
-	struct xpc_msg *msg;
-	s64 put = initial_put + 1;
-	int send_IPI = 0;
-
-	while (1) {
-
-		while (1) {
-			if (put == ch->w_local_GP.put)
-				break;
-
-			msg = (struct xpc_msg *)((u64)ch->local_msgqueue +
-						 (put % ch->local_nentries) *
-						 ch->msg_size);
-
-			if (!(msg->flags & XPC_M_READY))
-				break;
-
-			put++;
-		}
-
-		if (put == initial_put) {
-			/* nothing's changed */
-			break;
-		}
-
-		if (cmpxchg_rel(&ch->local_GP->put, initial_put, put) !=
-		    initial_put) {
-			/* someone else beat us to it */
-			DBUG_ON(ch->local_GP->put < initial_put);
-			break;
-		}
-
-		/* we just set the new value of local_GP->put */
-
-		dev_dbg(xpc_chan, "local_GP->put changed to %ld, partid=%d, "
-			"channel=%d\n", put, ch->partid, ch->number);
-
-		send_IPI = 1;
-
-		/*
-		 * We need to ensure that the message referenced by
-		 * local_GP->put is not XPC_M_READY or that local_GP->put
-		 * equals w_local_GP.put, so we'll go have a look.
-		 */
-		initial_put = put;
-	}
-
-	if (send_IPI)
-		xpc_IPI_send_msgrequest(ch);
-}
-
-/*
- * Common code that does the actual sending of the message by advancing the
- * local message queue's Put value and sends an IPI to the partition the
- * message is being sent to.
- */
-static enum xp_retval
-xpc_send_msg(struct xpc_channel *ch, struct xpc_msg *msg, u8 notify_type,
-	     xpc_notify_func func, void *key)
-{
-	enum xp_retval ret = xpSuccess;
-	struct xpc_notify *notify = notify;
-	s64 put, msg_number = msg->number;
-
-	DBUG_ON(notify_type == XPC_N_CALL && func == NULL);
-	DBUG_ON((((u64)msg - (u64)ch->local_msgqueue) / ch->msg_size) !=
-		msg_number % ch->local_nentries);
-	DBUG_ON(msg->flags & XPC_M_READY);
-
-	if (ch->flags & XPC_C_DISCONNECTING) {
-		/* drop the reference grabbed in xpc_allocate_msg() */
-		xpc_msgqueue_deref(ch);
-		return ch->reason;
-	}
-
-	if (notify_type != 0) {
-		/*
-		 * Tell the remote side to send an ACK interrupt when the
-		 * message has been delivered.
-		 */
-		msg->flags |= XPC_M_INTERRUPT;
-
-		atomic_inc(&ch->n_to_notify);
-
-		notify = &ch->notify_queue[msg_number % ch->local_nentries];
-		notify->func = func;
-		notify->key = key;
-		notify->type = notify_type;
-
-		/* >>> is a mb() needed here? */
-
-		if (ch->flags & XPC_C_DISCONNECTING) {
-			/*
-			 * An error occurred between our last error check and
-			 * this one. We will try to clear the type field from
-			 * the notify entry. If we succeed then
-			 * xpc_disconnect_channel() didn't already process
-			 * the notify entry.
-			 */
-			if (cmpxchg(&notify->type, notify_type, 0) ==
-			    notify_type) {
-				atomic_dec(&ch->n_to_notify);
-				ret = ch->reason;
-			}
-
-			/* drop the reference grabbed in xpc_allocate_msg() */
-			xpc_msgqueue_deref(ch);
-			return ret;
-		}
-	}
-
-	msg->flags |= XPC_M_READY;
-
-	/*
-	 * The preceding store of msg->flags must occur before the following
-	 * load of ch->local_GP->put.
-	 */
-	mb();
-
-	/* see if the message is next in line to be sent, if so send it */
-
-	put = ch->local_GP->put;
-	if (put == msg_number)
-		xpc_send_msgs(ch, put);
-
-	/* drop the reference grabbed in xpc_allocate_msg() */
-	xpc_msgqueue_deref(ch);
-	return ret;
-}
-
-/*
- * Send a message previously allocated using xpc_initiate_allocate() on the
- * specified channel connected to the specified partition.
- *
- * This routine will not wait for the message to be received, nor will
- * notification be given when it does happen. Once this routine has returned
- * the message entry allocated via xpc_initiate_allocate() is no longer
- * accessable to the caller.
- *
- * This routine, although called by users, does not call xpc_part_ref() to
- * ensure that the partition infrastructure is in place. It relies on the
- * fact that we called xpc_msgqueue_ref() in xpc_allocate_msg().
+ * Once sent, this routine will not wait for the message to be received, nor
+ * will notification be given when it does happen.
  *
  * Arguments:
  *
  *	partid - ID of partition to which the channel is connected.
  *	ch_number - channel # to send message on.
- *	payload - pointer to the payload area allocated via
- *			xpc_initiate_allocate().
+ *	flags - see xp.h for valid flags.
+ *	payload - pointer to the payload which is to be sent.
+ *	payload_size - size of the payload in bytes.
  */
 enum xp_retval
-xpc_initiate_send(short partid, int ch_number, void *payload)
+xpc_initiate_send(short partid, int ch_number, u32 flags, void *payload,
+		  u16 payload_size)
 {
 	struct xpc_partition *part = &xpc_partitions[partid];
-	struct xpc_msg *msg = XPC_MSG_ADDRESS(payload);
-	enum xp_retval ret;
+	enum xp_retval ret = xpUnknownReason;
 
-	dev_dbg(xpc_chan, "msg=0x%p, partid=%d, channel=%d\n", (void *)msg,
+	dev_dbg(xpc_chan, "payload=0x%p, partid=%d, channel=%d\n", payload,
 		partid, ch_number);
 
-	DBUG_ON(partid <= 0 || partid >= XP_MAX_PARTITIONS);
+	DBUG_ON(partid < 0 || partid >= xp_max_npartitions);
 	DBUG_ON(ch_number < 0 || ch_number >= part->nchannels);
-	DBUG_ON(msg == NULL);
+	DBUG_ON(payload == NULL);
 
-	ret = xpc_send_msg(&part->channels[ch_number], msg, 0, NULL, NULL);
+	if (xpc_part_ref(part)) {
+		ret = xpc_send_payload(&part->channels[ch_number], flags,
+				       payload, payload_size, 0, NULL, NULL);
+		xpc_part_deref(part);
+	}
 
 	return ret;
 }
 
 /*
- * Send a message previously allocated using xpc_initiate_allocate on the
- * specified channel connected to the specified partition.
+ * Send a message that contains the user's payload on the specified channel
+ * connected to the specified partition.
  *
- * This routine will not wait for the message to be sent. Once this routine
- * has returned the message entry allocated via xpc_initiate_allocate() is no
- * longer accessable to the caller.
+ * NOTE that this routine can sleep waiting for a message entry to become
+ * available. To not sleep, pass in the XPC_NOWAIT flag.
+ *
+ * This routine will not wait for the message to be sent or received.
  *
  * Once the remote end of the channel has received the message, the function
  * passed as an argument to xpc_initiate_send_notify() will be called. This
@@ -1943,158 +884,51 @@ xpc_initiate_send(short partid, int ch_number, void *payload)
  *
  * If this routine returns an error, the caller's function will NOT be called.
  *
- * This routine, although called by users, does not call xpc_part_ref() to
- * ensure that the partition infrastructure is in place. It relies on the
- * fact that we called xpc_msgqueue_ref() in xpc_allocate_msg().
- *
  * Arguments:
  *
  *	partid - ID of partition to which the channel is connected.
  *	ch_number - channel # to send message on.
- *	payload - pointer to the payload area allocated via
- *			xpc_initiate_allocate().
+ *	flags - see xp.h for valid flags.
+ *	payload - pointer to the payload which is to be sent.
+ *	payload_size - size of the payload in bytes.
  *	func - function to call with asynchronous notification of message
  *		  receipt. THIS FUNCTION MUST BE NON-BLOCKING.
  *	key - user-defined key to be passed to the function when it's called.
  */
 enum xp_retval
-xpc_initiate_send_notify(short partid, int ch_number, void *payload,
-			 xpc_notify_func func, void *key)
+xpc_initiate_send_notify(short partid, int ch_number, u32 flags, void *payload,
+			 u16 payload_size, xpc_notify_func func, void *key)
 {
 	struct xpc_partition *part = &xpc_partitions[partid];
-	struct xpc_msg *msg = XPC_MSG_ADDRESS(payload);
-	enum xp_retval ret;
+	enum xp_retval ret = xpUnknownReason;
 
-	dev_dbg(xpc_chan, "msg=0x%p, partid=%d, channel=%d\n", (void *)msg,
+	dev_dbg(xpc_chan, "payload=0x%p, partid=%d, channel=%d\n", payload,
 		partid, ch_number);
 
-	DBUG_ON(partid <= 0 || partid >= XP_MAX_PARTITIONS);
+	DBUG_ON(partid < 0 || partid >= xp_max_npartitions);
 	DBUG_ON(ch_number < 0 || ch_number >= part->nchannels);
-	DBUG_ON(msg == NULL);
+	DBUG_ON(payload == NULL);
 	DBUG_ON(func == NULL);
 
-	ret = xpc_send_msg(&part->channels[ch_number], msg, XPC_N_CALL,
-			   func, key);
-	return ret;
-}
-
-static struct xpc_msg *
-xpc_pull_remote_msg(struct xpc_channel *ch, s64 get)
-{
-	struct xpc_partition *part = &xpc_partitions[ch->partid];
-	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) {
-		/* we were interrupted by a signal */
-		return NULL;
-	}
-
-	while (get >= ch->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;
-
-		DBUG_ON(ch->next_msg_to_pull >= ch->w_remote_GP.put);
-		nmsgs = ch->w_remote_GP.put - ch->next_msg_to_pull;
-		if (msg_index + nmsgs > ch->remote_nentries) {
-			/* ignore the ones that wrap the msg queue for now */
-			nmsgs = ch->remote_nentries - msg_index;
-		}
-
-		msg_offset = msg_index * ch->msg_size;
-		msg = (struct xpc_msg *)((u64)ch->remote_msgqueue + msg_offset);
-		remote_msg = (struct xpc_msg *)(ch->remote_msgqueue_pa +
-						msg_offset);
-
-		ret = xpc_pull_remote_cachelines(part, msg, remote_msg,
-						 nmsgs * ch->msg_size);
-		if (ret != xpSuccess) {
-
-			dev_dbg(xpc_chan, "failed to pull %d msgs starting with"
-				" msg %ld from partition %d, channel=%d, "
-				"ret=%d\n", nmsgs, ch->next_msg_to_pull,
-				ch->partid, ch->number, ret);
-
-			XPC_DEACTIVATE_PARTITION(part, ret);
-
-			mutex_unlock(&ch->msg_to_pull_mutex);
-			return NULL;
-		}
-
-		ch->next_msg_to_pull += nmsgs;
+	if (xpc_part_ref(part)) {
+		ret = xpc_send_payload(&part->channels[ch_number], flags,
+				       payload, payload_size, XPC_N_CALL, func,
+				       key);
+		xpc_part_deref(part);
 	}
-
-	mutex_unlock(&ch->msg_to_pull_mutex);
-
-	/* return the message we were looking for */
-	msg_offset = (get % ch->remote_nentries) * ch->msg_size;
-	msg = (struct xpc_msg *)((u64)ch->remote_msgqueue + msg_offset);
-
-	return msg;
-}
-
-/*
- * Get a message to be delivered.
- */
-static struct xpc_msg *
-xpc_get_deliverable_msg(struct xpc_channel *ch)
-{
-	struct xpc_msg *msg = NULL;
-	s64 get;
-
-	do {
-		if (ch->flags & XPC_C_DISCONNECTING)
-			break;
-
-		get = ch->w_local_GP.get;
-		rmb();	/* guarantee that .get loads before .put */
-		if (get == ch->w_remote_GP.put)
-			break;
-
-		/* There are messages waiting to be pulled and delivered.
-		 * We need to try to secure one for ourselves. We'll do this
-		 * by trying to increment w_local_GP.get and hope that no one
-		 * else beats us to it. If they do, we'll we'll simply have
-		 * to try again for the next one.
-		 */
-
-		if (cmpxchg(&ch->w_local_GP.get, get, get + 1) == get) {
-			/* we got the entry referenced by get */
-
-			dev_dbg(xpc_chan, "w_local_GP.get changed to %ld, "
-				"partid=%d, channel=%d\n", get + 1,
-				ch->partid, ch->number);
-
-			/* pull the message from the remote partition */
-
-			msg = xpc_pull_remote_msg(ch, get);
-
-			DBUG_ON(msg != NULL && msg->number != get);
-			DBUG_ON(msg != NULL && (msg->flags & XPC_M_DONE));
-			DBUG_ON(msg != NULL && !(msg->flags & XPC_M_READY));
-
-			break;
-		}
-
-	} while (1);
-
-	return msg;
+	return ret;
 }
 
 /*
- * Deliver a message to its intended recipient.
+ * Deliver a message's payload to its intended recipient.
  */
 void
-xpc_deliver_msg(struct xpc_channel *ch)
+xpc_deliver_payload(struct xpc_channel *ch)
 {
-	struct xpc_msg *msg;
+	void *payload;
 
-	msg = xpc_get_deliverable_msg(ch);
-	if (msg != NULL) {
+	payload = xpc_get_deliverable_payload(ch);
+	if (payload != NULL) {
 
 		/*
 		 * This ref is taken to protect the payload itself from being
@@ -2106,18 +940,16 @@ xpc_deliver_msg(struct xpc_channel *ch)
 		atomic_inc(&ch->kthreads_active);
 
 		if (ch->func != NULL) {
-			dev_dbg(xpc_chan, "ch->func() called, msg=0x%p, "
-				"msg_number=%ld, partid=%d, channel=%d\n",
-				(void *)msg, msg->number, ch->partid,
+			dev_dbg(xpc_chan, "ch->func() called, payload=0x%p "
+				"partid=%d channel=%d\n", payload, ch->partid,
 				ch->number);
 
 			/* deliver the message to its intended recipient */
-			ch->func(xpMsgReceived, ch->partid, ch->number,
-				 &msg->payload, ch->key);
+			ch->func(xpMsgReceived, ch->partid, ch->number, payload,
+				 ch->key);
 
-			dev_dbg(xpc_chan, "ch->func() returned, msg=0x%p, "
-				"msg_number=%ld, partid=%d, channel=%d\n",
-				(void *)msg, msg->number, ch->partid,
+			dev_dbg(xpc_chan, "ch->func() returned, payload=0x%p "
+				"partid=%d channel=%d\n", payload, ch->partid,
 				ch->number);
 		}
 
@@ -2126,118 +958,31 @@ xpc_deliver_msg(struct xpc_channel *ch)
 }
 
 /*
- * Now we actually acknowledge the messages that have been delivered and ack'd
- * by advancing the cached remote message queue's Get value and if requested
- * send an IPI to the message sender's partition.
- */
-static void
-xpc_acknowledge_msgs(struct xpc_channel *ch, s64 initial_get, u8 msg_flags)
-{
-	struct xpc_msg *msg;
-	s64 get = initial_get + 1;
-	int send_IPI = 0;
-
-	while (1) {
-
-		while (1) {
-			if (get == ch->w_local_GP.get)
-				break;
-
-			msg = (struct xpc_msg *)((u64)ch->remote_msgqueue +
-						 (get % ch->remote_nentries) *
-						 ch->msg_size);
-
-			if (!(msg->flags & XPC_M_DONE))
-				break;
-
-			msg_flags |= msg->flags;
-			get++;
-		}
-
-		if (get == initial_get) {
-			/* nothing's changed */
-			break;
-		}
-
-		if (cmpxchg_rel(&ch->local_GP->get, initial_get, get) !=
-		    initial_get) {
-			/* someone else beat us to it */
-			DBUG_ON(ch->local_GP->get <= initial_get);
-			break;
-		}
-
-		/* we just set the new value of local_GP->get */
-
-		dev_dbg(xpc_chan, "local_GP->get changed to %ld, partid=%d, "
-			"channel=%d\n", get, ch->partid, ch->number);
-
-		send_IPI = (msg_flags & XPC_M_INTERRUPT);
-
-		/*
-		 * We need to ensure that the message referenced by
-		 * local_GP->get is not XPC_M_DONE or that local_GP->get
-		 * equals w_local_GP.get, so we'll go have a look.
-		 */
-		initial_get = get;
-	}
-
-	if (send_IPI)
-		xpc_IPI_send_msgrequest(ch);
-}
-
-/*
- * Acknowledge receipt of a delivered message.
- *
- * If a message has XPC_M_INTERRUPT set, send an interrupt to the partition
- * that sent the message.
+ * Acknowledge receipt of a delivered message's payload.
  *
  * This function, although called by users, does not call xpc_part_ref() to
  * ensure that the partition infrastructure is in place. It relies on the
- * fact that we called xpc_msgqueue_ref() in xpc_deliver_msg().
+ * fact that we called xpc_msgqueue_ref() in xpc_deliver_payload().
  *
  * Arguments:
  *
  *	partid - ID of partition to which the channel is connected.
  *	ch_number - channel # message received on.
  *	payload - pointer to the payload area allocated via
- *			xpc_initiate_allocate().
+ *			xpc_initiate_send() or xpc_initiate_send_notify().
  */
 void
 xpc_initiate_received(short partid, int ch_number, void *payload)
 {
 	struct xpc_partition *part = &xpc_partitions[partid];
 	struct xpc_channel *ch;
-	struct xpc_msg *msg = XPC_MSG_ADDRESS(payload);
-	s64 get, msg_number = msg->number;
 
-	DBUG_ON(partid <= 0 || partid >= XP_MAX_PARTITIONS);
+	DBUG_ON(partid < 0 || partid >= xp_max_npartitions);
 	DBUG_ON(ch_number < 0 || ch_number >= part->nchannels);
 
 	ch = &part->channels[ch_number];
+	xpc_received_payload(ch, payload);
 
-	dev_dbg(xpc_chan, "msg=0x%p, msg_number=%ld, partid=%d, channel=%d\n",
-		(void *)msg, msg_number, ch->partid, ch->number);
-
-	DBUG_ON((((u64)msg - (u64)ch->remote_msgqueue) / ch->msg_size) !=
-		msg_number % ch->remote_nentries);
-	DBUG_ON(msg->flags & XPC_M_DONE);
-
-	msg->flags |= XPC_M_DONE;
-
-	/*
-	 * The preceding store of msg->flags must occur before the following
-	 * load of ch->local_GP->get.
-	 */
-	mb();
-
-	/*
-	 * See if this message is next in line to be acknowledged as having
-	 * been delivered.
-	 */
-	get = ch->local_GP->get;
-	if (get == msg_number)
-		xpc_acknowledge_msgs(ch, get, msg->flags);
-
-	/* the call to xpc_msgqueue_ref() was done by xpc_deliver_msg()  */
+	/* the call to xpc_msgqueue_ref() was done by xpc_deliver_payload()  */
 	xpc_msgqueue_deref(ch);
 }