sgi-xp: setup the notify GRU message queue
[safe/jmp/linux-2.6] / drivers / misc / sgi-xp / xpc_channel.c
index bfcb9ea..9cd2ebe 100644 (file)
  *
  */
 
-#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, partid_t 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 xpc_retval
-xpc_setup_infrastructure(struct xpc_partition *part)
-{
-       int ret, cpuid;
-       struct timer_list *timer;
-       partid_t 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 xpcNoMemory;
-       }
-
-       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 xpcNoMemory;
-       }
-
-       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 xpcNoMemory;
-       }
-
-       /* 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 xpcNoMemory;
-       }
-
-       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 xpcNoMemory;
-       }
-
-       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 xpcLackOfResources;
-       }
-
-       /* 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 xpcSuccess;
-}
-
-/*
- * 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 xpc_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 xpcSuccess;
-
-       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 xpc_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;
-       partid_t partid = XPC_PARTID(part);
-       enum xpc_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 != xpcSuccess) {
-               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 xpcBadMagic;
-               }
-
-               /* they've not been initialized yet */
-               return xpcRetry;
-       }
-
-       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 xpcInvalidAddress;
-               }
-
-               /* 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 xpcRetry;
-
-       return xpcSuccess;
-}
-
-/*
- * 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 xpc_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 != xpcSuccess) {
-                       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 != xpcSuccess) {
-                       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 xpc_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 xpcSuccess;
-       }
-
-       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 xpcNoMemory;
-}
-
-/*
- * Allocate the cached remote message queue.
- */
-static enum xpc_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 xpcSuccess;
-       }
-
-       dev_dbg(xpc_chan, "can't get memory for cached remote message queue, "
-               "partid=%d, channel=%d\n", ch->partid, ch->number);
-       return xpcNoMemory;
-}
-
-/*
- * Allocate message queues and other stuff associated with a channel.
- *
- * Note: Assumes all of the channel sizes are filled in.
- */
-static enum xpc_retval
-xpc_allocate_msgqueues(struct xpc_channel *ch)
-{
-       unsigned long irq_flags;
-       enum xpc_retval ret;
-
-       DBUG_ON(ch->flags & XPC_C_SETUP);
-
-       ret = xpc_allocate_local_msgqueue(ch);
-       if (ret != xpcSuccess)
-               return ret;
-
-       ret = xpc_allocate_remote_msgqueue(ch);
-       if (ret != xpcSuccess) {
-               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 xpcSuccess;
-}
-
-/*
  * Process a connect message from a remote partition.
  *
  * Note: xpc_process_connect() is expecting to be called with the
@@ -552,7 +26,7 @@ xpc_allocate_msgqueues(struct xpc_channel *ch)
 static void
 xpc_process_connect(struct xpc_channel *ch, unsigned long *irq_flags)
 {
-       enum xpc_retval ret;
+       enum xp_retval ret;
 
        DBUG_ON(!spin_is_locked(&ch->lock));
 
@@ -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 != xpcSuccess)
+               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 xpc_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))
@@ -740,22 +120,36 @@ 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 */
 
        if (ch->flags & XPC_C_DISCONNECTINGCALLOUT_MADE) {
                spin_unlock_irqrestore(&ch->lock, *irq_flags);
-               xpc_disconnect_callout(ch, xpcDisconnected);
+               xpc_disconnect_callout(ch, xpDisconnected);
                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);
+
+       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 disconnected, clear all other flags except XPC_C_WDISCONNECT */
+       /*
+        * 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;
        }
 }
 
@@ -784,14 +178,14 @@ 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 =
            &part->remote_openclose_args[ch_number];
        struct xpc_channel *ch = &part->channels[ch_number];
-       enum xpc_retval reason;
+       enum xp_retval reason;
 
        spin_lock_irqsave(&ch->lock, irq_flags);
 
@@ -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:
@@ -871,14 +263,14 @@ again:
 
                if (!(ch->flags & XPC_C_DISCONNECTING)) {
                        reason = args->reason;
-                       if (reason <= xpcSuccess || reason > xpcUnknownReason)
-                               reason = xpcUnknownReason;
-                       else if (reason == xpcUnregistering)
-                               reason = xpcOtherUnregistering;
+                       if (reason <= xpSuccess || reason > xpUnknownReason)
+                               reason = xpUnknownReason;
+                       else if (reason == xpUnregistering)
+                               reason = xpOtherUnregistering;
 
                        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) {
-                               XPC_DISCONNECT_CHANNEL(ch, xpcUnequalMsgSizes,
+                       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;
@@ -978,20 +369,20 @@ 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);
                        return;
                }
                if (!(ch->flags & XPC_C_OPENREQUEST)) {
-                       XPC_DISCONNECT_CHANNEL(ch, xpcOpenCloseError,
+                       XPC_DISCONNECT_CHANNEL(ch, xpOpenCloseError,
                                               &irq_flags);
                        spin_unlock_irqrestore(&ch->lock, irq_flags);
                        return;
@@ -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,
@@ -1042,18 +433,18 @@ again:
 /*
  * Attempt to establish a channel connection to a remote partition.
  */
-static enum xpc_retval
+static enum xp_retval
 xpc_connect_channel(struct xpc_channel *ch)
 {
        unsigned long irq_flags;
        struct xpc_registration *registration = &xpc_registrations[ch->number];
 
        if (mutex_trylock(&registration->mutex) == 0)
-               return xpcRetry;
+               return xpRetry;
 
        if (!XPC_CHANNEL_REGISTERED(ch->number)) {
                mutex_unlock(&registration->mutex);
-               return xpcUnregistered;
+               return xpUnregistered;
        }
 
        spin_lock_irqsave(&ch->lock, irq_flags);
@@ -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 */
 
                        /*
@@ -1095,13 +486,13 @@ xpc_connect_channel(struct xpc_channel *ch)
                         * the channel lock as needed.
                         */
                        mutex_unlock(&registration->mutex);
-                       XPC_DISCONNECT_CHANNEL(ch, xpcUnequalMsgSizes,
+                       XPC_DISCONNECT_CHANNEL(ch, xpUnequalMsgSizes,
                                               &irq_flags);
                        spin_unlock_irqrestore(&ch->lock, irq_flags);
-                       return xpcUnequalMsgSizes;
+                       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;
@@ -1114,161 +505,25 @@ 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);
 
        spin_unlock_irqrestore(&ch->lock, irq_flags);
 
-       return xpcSuccess;
-}
-
-/*
- * 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, xpcMsgDelivered,
-                                          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);
+       return xpSuccess;
 }
 
 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);
        }
 }
 
@@ -1335,7 +590,7 @@ xpc_process_channel_activity(struct xpc_partition *part)
  * at the same time.
  */
 void
-xpc_partition_going_down(struct xpc_partition *part, enum xpc_retval reason)
+xpc_partition_going_down(struct xpc_partition *part, enum xp_retval reason)
 {
        unsigned long irq_flags;
        int ch_number;
@@ -1369,72 +624,19 @@ xpc_partition_going_down(struct xpc_partition *part, enum xpc_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)
-{
-       partid_t 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.
  */
 void
 xpc_initiate_connect(int ch_number)
 {
-       partid_t partid;
+       short partid;
        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)) {
@@ -1456,13 +658,13 @@ xpc_connected_callout(struct xpc_channel *ch)
        /* let the registerer know that a connection has been established */
 
        if (ch->func != NULL) {
-               dev_dbg(xpc_chan, "ch->func() called, reason=xpcConnected, "
+               dev_dbg(xpc_chan, "ch->func() called, reason=xpConnected, "
                        "partid=%d, channel=%d\n", ch->partid, ch->number);
 
-               ch->func(xpcConnected, ch->partid, ch->number,
+               ch->func(xpConnected, ch->partid, ch->number,
                         (void *)(u64)ch->local_nentries, ch->key);
 
-               dev_dbg(xpc_chan, "ch->func() returned, reason=xpcConnected, "
+               dev_dbg(xpc_chan, "ch->func() returned, reason=xpConnected, "
                        "partid=%d, channel=%d\n", ch->partid, ch->number);
        }
 }
@@ -1484,14 +686,14 @@ void
 xpc_initiate_disconnect(int ch_number)
 {
        unsigned long irq_flags;
-       partid_t partid;
+       short partid;
        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)) {
@@ -1503,7 +705,7 @@ xpc_initiate_disconnect(int ch_number)
                        if (!(ch->flags & XPC_C_DISCONNECTED)) {
                                ch->flags |= XPC_C_WDISCONNECT;
 
-                               XPC_DISCONNECT_CHANNEL(ch, xpcUnregistering,
+                               XPC_DISCONNECT_CHANNEL(ch, xpUnregistering,
                                                       &irq_flags);
                        }
 
@@ -1528,7 +730,7 @@ xpc_initiate_disconnect(int ch_number)
  */
 void
 xpc_disconnect_channel(const int line, struct xpc_channel *ch,
-                      enum xpc_retval reason, unsigned long *irq_flags)
+                      enum xp_retval reason, unsigned long *irq_flags)
 {
        u32 channel_was_connected = (ch->flags & XPC_C_CONNECTED);
 
@@ -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;
@@ -1563,7 +765,7 @@ xpc_disconnect_channel(const int line, struct xpc_channel *ch,
 
        } else if ((ch->flags & XPC_C_CONNECTEDCALLOUT_MADE) &&
                   !(ch->flags & XPC_C_DISCONNECTINGCALLOUT)) {
-               /* start a kthread that will do the xpcDisconnecting callout */
+               /* start a kthread that will do the xpDisconnecting callout */
                xpc_create_kthreads(ch, 1, 1);
        }
 
@@ -1575,7 +777,7 @@ xpc_disconnect_channel(const int line, struct xpc_channel *ch,
 }
 
 void
-xpc_disconnect_callout(struct xpc_channel *ch, enum xpc_retval reason)
+xpc_disconnect_callout(struct xpc_channel *ch, enum xp_retval reason)
 {
        /*
         * Let the channel's registerer know that the channel is being
@@ -1598,13 +800,13 @@ xpc_disconnect_callout(struct xpc_channel *ch, enum xpc_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 xpc_retval
+enum xp_retval
 xpc_allocate_msg_wait(struct xpc_channel *ch)
 {
-       enum xpc_retval ret;
+       enum xp_retval ret;
 
        if (ch->flags & XPC_C_DISCONNECTING) {
-               DBUG_ON(ch->reason == xpcInterrupted);
+               DBUG_ON(ch->reason == xpInterrupted);
                return ch->reason;
        }
 
@@ -1614,326 +816,65 @@ xpc_allocate_msg_wait(struct xpc_channel *ch)
 
        if (ch->flags & XPC_C_DISCONNECTING) {
                ret = ch->reason;
-               DBUG_ON(ch->reason == xpcInterrupted);
+               DBUG_ON(ch->reason == xpInterrupted);
        } else if (ret == 0) {
-               ret = xpcTimeout;
+               ret = xpTimeout;
        } else {
-               ret = xpcInterrupted;
+               ret = xpInterrupted;
        }
 
        return ret;
 }
 
 /*
- * Allocate an entry for a message from the message queue associated with the
- * specified channel.
- */
-static enum xpc_retval
-xpc_allocate_msg(struct xpc_channel *ch, u32 flags,
-                struct xpc_msg **address_of_msg)
-{
-       struct xpc_msg *msg;
-       enum xpc_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 xpcNotConnected;
-       }
-
-       /*
-        * 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 = xpcTimeout;
-
-       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 == xpcTimeout)
-                       xpc_IPI_send_local_msgrequest(ch);
-
-               if (flags & XPC_NOWAIT) {
-                       xpc_msgqueue_deref(ch);
-                       return xpcNoWait;
-               }
-
-               ret = xpc_allocate_msg_wait(ch);
-               if (ret != xpcInterrupted && ret != xpcTimeout) {
-                       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 xpcSuccess;
-}
-
-/*
- * 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 xpc_retval
-xpc_initiate_allocate(partid_t partid, int ch_number, u32 flags, void **payload)
-{
-       struct xpc_partition *part = &xpc_partitions[partid];
-       enum xpc_retval ret = xpcUnknownReason;
-       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 xpc_retval
-xpc_send_msg(struct xpc_channel *ch, struct xpc_msg *msg, u8 notify_type,
-            xpc_notify_func func, void *key)
-{
-       enum xpc_retval ret = xpcSuccess;
-       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 xpc_retval
-xpc_initiate_send(partid_t partid, int ch_number, void *payload)
+enum xp_retval
+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 xpc_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(partid_t 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 xpc_retval
-xpc_initiate_send_notify(partid_t partid, int ch_number, void *payload,
-                        xpc_notify_func func, void *key)
+enum xp_retval
+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 xpc_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 xpc_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 != xpcSuccess) {
-
-                       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(xpcMsgReceived, 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(partid_t partid, int ch_number, void *payload)
+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);
 }