diff options
Diffstat (limited to 'arch/ia64/sn/kernel/xpc_channel.c')
| -rw-r--r-- | arch/ia64/sn/kernel/xpc_channel.c | 2379 |
1 files changed, 0 insertions, 2379 deletions
diff --git a/arch/ia64/sn/kernel/xpc_channel.c b/arch/ia64/sn/kernel/xpc_channel.c deleted file mode 100644 index 44ccc0d..0000000 --- a/arch/ia64/sn/kernel/xpc_channel.c +++ /dev/null @@ -1,2379 +0,0 @@ -/* - * This file is subject to the terms and conditions of the GNU General Public - * License. See the file "COPYING" in the main directory of this archive - * for more details. - * - * Copyright (c) 2004-2006 Silicon Graphics, Inc. All Rights Reserved. - */ - - -/* - * Cross Partition Communication (XPC) channel support. - * - * This is the part of XPC that manages the channels and - * sends/receives messages across them to/from other partitions. - * - */ - - -#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 <asm/sn/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); - if ((IPI_amo = part->local_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; - - - // >>> may want to check for ch->flags & XPC_C_DISCONNECTING between - // >>> iterations of the for-loop, bail if set? - - // >>> should we impose a minimum #of entries? like 4 or 8? - 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); - - // >>> may want to check for ch->flags & XPC_C_DISCONNECTING between - // >>> iterations of the for-loop, bail if set? - - // >>> should we impose a minimum #of entries? like 4 or 8? - 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); - - if ((ret = xpc_allocate_local_msgqueue(ch)) != xpcSuccess) { - return ret; - } - - if ((ret = xpc_allocate_remote_msgqueue(ch)) != 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 - * spin_lock_irqsave held and will leave it locked upon return. - */ -static void -xpc_process_connect(struct xpc_channel *ch, unsigned long *irq_flags) -{ - enum xpc_retval ret; - - - DBUG_ON(!spin_is_locked(&ch->lock)); - - if (!(ch->flags & XPC_C_OPENREQUEST) || - !(ch->flags & XPC_C_ROPENREQUEST)) { - /* nothing more to do for now */ - return; - } - DBUG_ON(!(ch->flags & XPC_C_CONNECTING)); - - if (!(ch->flags & XPC_C_SETUP)) { - spin_unlock_irqrestore(&ch->lock, *irq_flags); - ret = xpc_allocate_msgqueues(ch); - spin_lock_irqsave(&ch->lock, *irq_flags); - - if (ret != xpcSuccess) { - XPC_DISCONNECT_CHANNEL(ch, ret, irq_flags); - } - 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); - } - - 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", - ch->number, ch->partid); - - spin_unlock_irqrestore(&ch->lock, *irq_flags); - xpc_create_kthreads(ch, 1, 0); - spin_lock_irqsave(&ch->lock, *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(¬ify->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 -xpc_process_disconnect(struct xpc_channel *ch, unsigned long *irq_flags) -{ - struct xpc_partition *part = &xpc_partitions[ch->partid]; - u32 channel_was_connected = (ch->flags & XPC_C_WASCONNECTED); - - - DBUG_ON(!spin_is_locked(&ch->lock)); - - if (!(ch->flags & XPC_C_DISCONNECTING)) { - return; - } - - DBUG_ON(!(ch->flags & XPC_C_CLOSEREQUEST)); - - /* make sure all activity has settled down first */ - - if (atomic_read(&ch->kthreads_assigned) > 0 || - atomic_read(&ch->references) > 0) { - return; - } - DBUG_ON((ch->flags & XPC_C_CONNECTEDCALLOUT_MADE) && - !(ch->flags & XPC_C_DISCONNECTINGCALLOUT_MADE)); - - if (part->act_state == XPC_P_DEACTIVATING) { - /* can't proceed until the other side disengages from us */ - if (xpc_partition_engaged(1UL << ch->partid)) { - return; - } - - } else { - - /* as long as the other side is up do the full protocol */ - - if (!(ch->flags & XPC_C_RCLOSEREQUEST)) { - return; - } - - if (!(ch->flags & XPC_C_CLOSEREPLY)) { - ch->flags |= XPC_C_CLOSEREPLY; - xpc_IPI_send_closereply(ch, irq_flags); - } - - if (!(ch->flags & XPC_C_RCLOSEREPLY)) { - return; - } - } - - /* 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); - } - - /* both sides are disconnected now */ - - if (ch->flags & XPC_C_DISCONNECTINGCALLOUT_MADE) { - spin_unlock_irqrestore(&ch->lock, *irq_flags); - xpc_disconnect_callout(ch, xpcDisconnected); - spin_lock_irqsave(&ch->lock, *irq_flags); - } - - /* it's now safe to free the channel's message queues */ - xpc_free_msgqueues(ch); - - /* mark disconnected, clear all other flags except XPC_C_WDISCONNECT */ - ch->flags = (XPC_C_DISCONNECTED | (ch->flags & XPC_C_WDISCONNECT)); - - atomic_dec(&part->nchannels_active); - - if (channel_was_connected) { - dev_info(xpc_chan, "channel %d to partition %d disconnected, " - "reason=%d\n", ch->number, ch->partid, ch->reason); - } - - 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); - } - ch->delayed_IPI_flags = 0; - } -} - - -/* - * 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) -{ - 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; - - - - spin_lock_irqsave(&ch->lock, irq_flags); - -again: - - if ((ch->flags & XPC_C_DISCONNECTED) && - (ch->flags & XPC_C_WDISCONNECT)) { - /* - * Delay processing IPI flags until thread waiting disconnect - * has had a chance to see that the channel is disconnected. - */ - ch->delayed_IPI_flags |= IPI_flags; - spin_unlock_irqrestore(&ch->lock, irq_flags); - return; - } - - - if (IPI_flags & XPC_IPI_CLOSEREQUEST) { - - dev_dbg(xpc_chan, "XPC_IPI_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. - */ - - if (ch->flags & XPC_C_RCLOSEREQUEST) { - DBUG_ON(!(ch->flags & XPC_C_DISCONNECTING)); - DBUG_ON(!(ch->flags & XPC_C_CLOSEREQUEST)); - 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; - ch->flags |= XPC_C_RCLOSEREPLY; - - /* both sides have finished disconnecting */ - xpc_process_disconnect(ch, &irq_flags); - DBUG_ON(!(ch->flags & XPC_C_DISCONNECTED)); - goto 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); - } - spin_unlock_irqrestore(&ch->lock, irq_flags); - return; - } - - XPC_SET_REASON(ch, 0, 0); - ch->flags &= ~XPC_C_DISCONNECTED; - - atomic_inc(&part->nchannels_active); - ch->flags |= (XPC_C_CONNECTING | XPC_C_ROPENREQUEST); - } - - IPI_flags &= ~(XPC_IPI_OPENREQUEST | XPC_IPI_OPENREPLY); - - /* - * The meaningful CLOSEREQUEST connection state fields are: - * reason = reason connection is to be closed - */ - - ch->flags |= XPC_C_RCLOSEREQUEST; - - if (!(ch->flags & XPC_C_DISCONNECTING)) { - reason = args->reason; - if (reason <= xpcSuccess || reason > xpcUnknownReason) { - reason = xpcUnknownReason; - } else if (reason == xpcUnregistering) { - reason = xpcOtherUnregistering; - } - - XPC_DISCONNECT_CHANNEL(ch, reason, &irq_flags); - - DBUG_ON(IPI_flags & XPC_IPI_CLOSEREPLY); - spin_unlock_irqrestore(&ch->lock, irq_flags); - return; - } - - xpc_process_disconnect(ch, &irq_flags); - } - - - if (IPI_flags & XPC_IPI_CLOSEREPLY) { - - dev_dbg(xpc_chan, "XPC_IPI_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); - spin_unlock_irqrestore(&ch->lock, irq_flags); - return; - } - - 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); - } - spin_unlock_irqrestore(&ch->lock, irq_flags); - return; - } - - ch->flags |= XPC_C_RCLOSEREPLY; - - if (ch->flags & XPC_C_CLOSEREPLY) { - /* both sides have finished disconnecting */ - xpc_process_disconnect(ch, &irq_flags); - } - } - - - if (IPI_flags & XPC_IPI_OPENREQUEST) { - - dev_dbg(xpc_chan, "XPC_IPI_OPENREQUEST (msg_size=%d, " - "local_nentries=%d) received from partid=%d, " - "channel=%d\n", args->msg_size, args->local_nentries, - ch->partid, ch->number); - - if (part->act_state == XPC_P_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; - spin_unlock_irqrestore(&ch->lock, irq_flags); - return; - } - DBUG_ON(!(ch->flags & (XPC_C_DISCONNECTED | - XPC_C_OPENREQUEST))); - DBUG_ON(ch->flags & (XPC_C_ROPENREQUEST | XPC_C_ROPENREPLY | - XPC_C_OPENREPLY | XPC_C_CONNECTED)); - - /* - * The meaningful OPENREQUEST connection state fields are: - * msg_size = size of channel's messages in bytes - * local_nentries = remote partition's local_nentries - */ - if (args->msg_size == 0 || args->local_nentries == 0) { - /* assume OPENREQUEST was delayed by mistake */ - spin_unlock_irqrestore(&ch->lock, irq_flags); - return; - } - - ch->flags |= (XPC_C_ROPENREQUEST | XPC_C_CONNECTING); - ch->remote_nentries = args->local_nentries; - - - if (ch->flags & XPC_C_OPENREQUEST) { - if (args->msg_size != ch->msg_size) { - XPC_DISCONNECT_CHANNEL(ch, xpcUnequalMsgSizes, - &irq_flags); - spin_unlock_irqrestore(&ch->lock, irq_flags); - return; - } - } else { - ch->msg_size = args->msg_size; - - XPC_SET_REASON(ch, 0, 0); - ch->flags &= ~XPC_C_DISCONNECTED; - - atomic_inc(&part->nchannels_active); - } - - xpc_process_connect(ch, &irq_flags); - } - - - if (IPI_flags & XPC_IPI_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); - - 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, - &irq_flags); - spin_unlock_irqrestore(&ch->lock, irq_flags); - return; - } - - DBUG_ON(!(ch->flags & XPC_C_ROPENREQUEST)); - DBUG_ON(ch->flags & XPC_C_CONNECTED); - - /* - * The meaningful OPENREPLY connection state fields are: - * local_msgqueue_pa = physical address of remote - * partition's local_msgqueue - * local_nentries = remote partition's local_nentries - * remote_nentries = remote partition's remote_nentries - */ - DBUG_ON(args->local_msgqueue_pa == 0); - DBUG_ON(args->local_nentries == 0); - DBUG_ON(args->remote_nentries == 0); - - ch->flags |= XPC_C_ROPENREPLY; - ch->remote_msgqueue_pa = args->local_msgqueue_pa; - - if (args->local_nentries < ch->remote_nentries) { - dev_dbg(xpc_chan, "XPC_IPI_OPENREPLY: new " - "remote_nentries=%d, old remote_nentries=%d, " - "partid=%d, channel=%d\n", - args->local_nentries, ch->remote_nentries, - ch->partid, ch->number); - - ch->remote_nentries = args->local_nentries; - } - if (args->remote_nentries < ch->local_nentries) { - dev_dbg(xpc_chan, "XPC_IPI_OPENREPLY: new " - "local_nentries=%d, old local_nentries=%d, " - "partid=%d, channel=%d\n", - args->remote_nentries, ch->local_nentries, - ch->partid, ch->number); - - ch->local_nentries = args->remote_nentries; - } - - xpc_process_connect(ch, &irq_flags); - } - - spin_unlock_irqrestore(&ch->lock, irq_flags); -} - - -/* - * Attempt to establish a channel connection to a remote partition. - */ -static enum xpc_retval -xpc_connect_channel(struct xpc_channel *ch) -{ - unsigned long irq_flags; - struct xpc_registration *registration = &xpc_registrations[ch->number]; - - - if (mutex_trylock(®istration->mutex) == 0) { - return xpcRetry; - } - - if (!XPC_CHANNEL_REGISTERED(ch->number)) { - mutex_unlock(®istration->mutex); - return xpcUnregistered; - } - - spin_lock_irqsave(&ch->lock, irq_flags); - - DBUG_ON(ch->flags & XPC_C_CONNECTED); - DBUG_ON(ch->flags & XPC_C_OPENREQUEST); - - if (ch->flags & XPC_C_DISCONNECTING) { - spin_unlock_irqrestore(&ch->lock, irq_flags); - mutex_unlock(®istration->mutex); - return ch->reason; - } - - - /* add info from the channel connect registration to the channel */ - - ch->kthreads_assigned_limit = registration->assigned_limit; - ch->kthreads_idle_limit = registration->idle_limit; - DBUG_ON(atomic_read(&ch->kthreads_assigned) != 0); - DBUG_ON(atomic_read(&ch->kthreads_idle) != 0); - DBUG_ON(atomic_read(&ch->kthreads_active) != 0); - - ch->func = registration->func; - DBUG_ON(registration->func == NULL); - ch->key = registration->key; - - ch->local_nentries = registration->nentries; - - if (ch->flags & XPC_C_ROPENREQUEST) { - if (registration->msg_size != ch->msg_size) { - /* the local and remote sides aren't the same */ - - /* - * Because XPC_DISCONNECT_CHANNEL() can block we're - * forced to up the registration sema before we unlock - * the channel lock. But that's okay here because we're - * done with the part that required the registration - * sema. XPC_DISCONNECT_CHANNEL() requires that the - * channel lock be locked and will unlock and relock - * the channel lock as needed. - */ - mutex_unlock(®istration->mutex); - XPC_DISCONNECT_CHANNEL(ch, xpcUnequalMsgSizes, - &irq_flags); - spin_unlock_irqrestore(&ch->lock, irq_flags); - return xpcUnequalMsgSizes; - } - } else { - ch->msg_size = registration->msg_size; - - XPC_SET_REASON(ch, 0, 0); - ch->flags &= ~XPC_C_DISCONNECTED; - - atomic_inc(&xpc_partitions[ch->partid].nchannels_active); - } - - mutex_unlock(®istration->mutex); - - - /* initiate the connection */ - - ch->flags |= (XPC_C_OPENREQUEST | XPC_C_CONNECTING); - xpc_IPI_send_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 < (volatile s64) 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 < (volatile s64) 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); -} - - -void -xpc_process_channel_activity(struct xpc_partition *part) -{ - unsigned long irq_flags; - u64 IPI_amo, IPI_flags; - struct xpc_channel *ch; - int ch_number; - u32 ch_flags; - - - IPI_amo = xpc_get_IPI_flags(part); - - /* - * Initiate channel connections for registered channels. - * - * For each connected channel that has pending messages activate idle - * kthreads and/or create new kthreads as needed. - */ - - for (ch_number = 0; ch_number < part->nchannels; ch_number++) { - ch = &part->channels[ch_number]; - - - /* - * Process any open or close related IPI 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); - } - - ch_flags = ch->flags; /* need an atomic snapshot of flags */ - - if (ch_flags & XPC_C_DISCONNECTING) { - spin_lock_irqsave(&ch->lock, irq_flags); - xpc_process_disconnect(ch, &irq_flags); - spin_unlock_irqrestore(&ch->lock, irq_flags); - continue; - } - - if (part->act_state == XPC_P_DEACTIVATING) { - continue; - } - - if (!(ch_flags & XPC_C_CONNECTED)) { - if (!(ch_flags & XPC_C_OPENREQUEST)) { - DBUG_ON(ch_flags & XPC_C_SETUP); - (void) xpc_connect_channel(ch); - } else { - spin_lock_irqsave(&ch->lock, irq_flags); - xpc_process_connect(ch, &irq_flags); - spin_unlock_irqrestore(&ch->lock, irq_flags); - } - continue; - } - - - /* - * Process any message related IPI 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); - } - } -} - - -/* - * XPC's heartbeat code calls this function to inform XPC that a partition is - * going down. XPC responds by tearing down the XPartition Communication - * infrastructure used for the just downed partition. - * - * XPC's heartbeat code will never call this function and xpc_partition_up() - * at the same time. Nor will it ever make multiple calls to either function - * at the same time. - */ -void -xpc_partition_going_down(struct xpc_partition *part, enum xpc_retval reason) -{ - unsigned long irq_flags; - int ch_number; - struct xpc_channel *ch; - - - dev_dbg(xpc_chan, "deactivating partition %d, reason=%d\n", - XPC_PARTID(part), reason); - - if (!xpc_part_ref(part)) { - /* infrastructure for this partition isn't currently set up */ - return; - } - - - /* disconnect channels associated with the partition going down */ - - for (ch_number = 0; ch_number < part->nchannels; ch_number++) { - ch = &part->channels[ch_number]; - - xpc_msgqueue_ref(ch); - spin_lock_irqsave(&ch->lock, irq_flags); - - XPC_DISCONNECT_CHANNEL(ch, reason, &irq_flags); - - spin_unlock_irqrestore(&ch->lock, irq_flags); - xpc_msgqueue_deref(ch); - } - - xpc_wakeup_channel_mgr(part); - - xpc_part_deref(part); -} - - -/* - * 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; - struct xpc_partition *part; - struct xpc_channel *ch; - - - DBUG_ON(ch_number < 0 || ch_number >= XPC_NCHANNELS); - - for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) { - part = &xpc_partitions[partid]; - - if (xpc_part_ref(part)) { - ch = &part->channels[ch_number]; - - /* - * Initiate the establishment of a connection on the - * newly registered channel to the remote partition. - */ - xpc_wakeup_channel_mgr(part); - xpc_part_deref(part); - } - } -} - - -void -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, " - "partid=%d, channel=%d\n", ch->partid, ch->number); - - ch->func(xpcConnected, ch->partid, ch->number, - (void *) (u64) ch->local_nentries, ch->key); - - dev_dbg(xpc_chan, "ch->func() returned, reason=xpcConnected, " - "partid=%d, channel=%d\n", ch->partid, ch->number); - } -} - - -/* - * Called by XP at the time of channel connection unregistration to cause - * XPC to teardown all current connections for the specified channel. - * - * Before returning xpc_initiate_disconnect() will wait until all connections - * on the specified channel have been closed/torndown. So the caller can be - * assured that they will not be receiving any more callouts from XPC to the - * function they registered via xpc_connect(). - * - * Arguments: - * - * ch_number - channel # to unregister. - */ -void -xpc_initiate_disconnect(int ch_number) -{ - unsigned long irq_flags; - partid_t partid; - struct xpc_partition *part; - struct xpc_channel *ch; - - - DBUG_ON(ch_number < 0 || ch_number >= XPC_NCHANNELS); - - /* initiate the channel disconnect for every active partition */ - for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) { - part = &xpc_partitions[partid]; - - if (xpc_part_ref(part)) { - ch = &part->channels[ch_number]; - xpc_msgqueue_ref(ch); - - spin_lock_irqsave(&ch->lock, irq_flags); - - if (!(ch->flags & XPC_C_DISCONNECTED)) { - ch->flags |= XPC_C_WDISCONNECT; - - XPC_DISCONNECT_CHANNEL(ch, xpcUnregistering, - &irq_flags); - } - - spin_unlock_irqrestore(&ch->lock, irq_flags); - - xpc_msgqueue_deref(ch); - xpc_part_deref(part); - } - } - - xpc_disconnect_wait(ch_number); -} - - -/* - * To disconnect a channel, and reflect it back to all who may be waiting. - * - * An OPEN is not allowed until XPC_C_DISCONNECTING is cleared by - * xpc_process_disconnect(), and if set, XPC_C_WDISCONNECT is cleared by - * xpc_disconnect_wait(). - * - * THE CHANNEL IS TO BE LOCKED BY THE CALLER AND WILL REMAIN LOCKED UPON RETURN. - */ -void -xpc_disconnect_channel(const int line, struct xpc_channel *ch, - enum xpc_retval reason, unsigned long *irq_flags) -{ - u32 channel_was_connected = (ch->flags & XPC_C_CONNECTED); - - - DBUG_ON(!spin_is_locked(&ch->lock)); - - if (ch->flags & (XPC_C_DISCONNECTING | XPC_C_DISCONNECTED)) { - return; - } - DBUG_ON(!(ch->flags & (XPC_C_CONNECTING | XPC_C_CONNECTED))); - - dev_dbg(xpc_chan, "reason=%d, line=%d, partid=%d, channel=%d\n", - reason, line, ch->partid, ch->number); - - XPC_SET_REASON(ch, reason, line); - - ch->flags |= (XPC_C_CLOSEREQUEST | XPC_C_DISCONNECTING); - /* some of these may not have been set */ - ch->flags &= ~(XPC_C_OPENREQUEST | XPC_C_OPENREPLY | - XPC_C_ROPENREQUEST | XPC_C_ROPENREPLY | - XPC_C_CONNECTING | XPC_C_CONNECTED); - - xpc_IPI_send_closerequest(ch, irq_flags); - - if (channel_was_connected) { - ch->flags |= XPC_C_WASCONNECTED; - } - - spin_unlock_irqrestore(&ch->lock, *irq_flags); - - /* wake all idle kthreads so they can exit */ - if (atomic_read(&ch->kthreads_idle) > 0) { - wake_up_all(&ch->idle_wq); - - } else if ((ch->flags & XPC_C_CONNECTEDCALLOUT_MADE) && - !(ch->flags & XPC_C_DISCONNECTINGCALLOUT)) { - /* start a kthread that will do the xpcDisconnecting callout */ - xpc_create_kthreads(ch, 1, 1); - } - - /* wake those waiting to allocate an entry from the local msg queue */ - if (atomic_read(&ch->n_on_msg_allocate_wq) > 0) { - wake_up(&ch->msg_allocate_wq); - } - - spin_lock_irqsave(&ch->lock, *irq_flags); -} - - -void -xpc_disconnect_callout(struct xpc_channel *ch, enum xpc_retval reason) -{ - /* - * Let the channel's registerer know that the channel is being - * disconnected. We don't want to do this if the registerer was never - * informed of a connection being made. - */ - - if (ch->func != NULL) { - dev_dbg(xpc_chan, "ch->func() called, reason=%d, partid=%d, " - "channel=%d\n", reason, ch->partid, ch->number); - - ch->func(reason, ch->partid, ch->number, NULL, ch->key); - - dev_dbg(xpc_chan, "ch->func() returned, reason=%d, partid=%d, " - "channel=%d\n", reason, ch->partid, ch->number); - } -} - - -/* - * 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 -xpc_allocate_msg_wait(struct xpc_channel *ch) -{ - enum xpc_retval ret; - - - if (ch->flags & XPC_C_DISCONNECTING) { - DBUG_ON(ch->reason == xpcInterrupted); // >>> Is this true? - return ch->reason; - } - - atomic_inc(&ch->n_on_msg_allocate_wq); - ret = interruptible_sleep_on_timeout(&ch->msg_allocate_wq, 1); - atomic_dec(&ch->n_on_msg_allocate_wq); - - if (ch->flags & XPC_C_DISCONNECTING) { - ret = ch->reason; - DBUG_ON(ch->reason == xpcInterrupted); // >>> Is this true? - } else if (ret == 0) { - ret = xpcTimeout; - } else { - ret = xpcInterrupted; - } - - 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 = (volatile s64) ch->w_local_GP.put; - if (put - (volatile s64) 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. - * - * Arguments: - * - * 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 == (volatile s64) 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((volatile s64) 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(¬ify->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(). - * - * 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(). - */ -enum xpc_retval -xpc_initiate_send(partid_t partid, int ch_number, void *payload) -{ - struct xpc_partition *part = &xpc_partitions[partid]; - struct xpc_msg *msg = XPC_MSG_ADDRESS(payload); - enum xpc_retval ret; - - - dev_dbg(xpc_chan, "msg=0x%p, partid=%d, channel=%d\n", (void *) msg, - partid, ch_number); - - DBUG_ON(partid <= 0 || partid >= XP_MAX_PARTITIONS); - DBUG_ON(ch_number < 0 || ch_number >= part->nchannels); - DBUG_ON(msg == NULL); - - ret = xpc_send_msg(&part->channels[ch_number], msg, 0, NULL, NULL); - - 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 sent. Once this routine - * has returned the message entry allocated via xpc_initiate_allocate() is no - * longer accessable to the caller. - * - * 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 - * allows the sender to free up or re-use any buffers referenced by the - * message, but does NOT mean the message has been processed at the remote - * end by a receiver. - * - * 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(). - * 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) -{ - struct xpc_partition *part = &xpc_partitions[partid]; - struct xpc_msg *msg = XPC_MSG_ADDRESS(payload); - enum xpc_retval ret; - - - dev_dbg(xpc_chan, "msg=0x%p, partid=%d, channel=%d\n", (void *) msg, - partid, ch_number); - - DBUG_ON(partid <= 0 || partid >= XP_MAX_PARTITIONS); - DBUG_ON(ch_number < 0 || ch_number >= part->nchannels); - DBUG_ON(msg == 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 >= - (volatile s64) ch->w_remote_GP.put); - nmsgs = (volatile s64) 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); - - if ((ret = xpc_pull_remote_cachelines(part, msg, remote_msg, - nmsgs * ch->msg_size)) != 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; - } - - mb(); /* >>> this may not be needed, we're not sure */ - - ch->next_msg_to_pull += nmsgs; - } - - 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 ((volatile u32) ch->flags & XPC_C_DISCONNECTING) { - break; - } - - get = (volatile s64) ch->w_local_GP.get; - if (get == (volatile s64) 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; -} - - -/* - * Deliver a message to its intended recipient. - */ -void -xpc_deliver_msg(struct xpc_channel *ch) -{ - struct xpc_msg *msg; - - - if ((msg = xpc_get_deliverable_msg(ch)) != NULL) { - - /* - * This ref is taken to protect the payload itself from being - * freed before the user is finished with it, which the user - * indicates by calling xpc_initiate_received(). - */ - xpc_msgqueue_ref(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, - ch->number); - - /* deliver the message to its intended recipient */ - ch->func(xpcMsgReceived, ch->partid, ch->number, - &msg->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, - ch->number); - } - - atomic_dec(&ch->kthreads_active); - } -} - - -/* - * 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 == (volatile s64) 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((volatile s64) 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. - * - * 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(). - * - * 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(). - */ -void -xpc_initiate_received(partid_t 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(ch_number < 0 || ch_number >= part->nchannels); - - ch = &part->channels[ch_number]; - - dev_dbg(xpc_chan, "msg=0x%p, msg_number=%ld, partid=%d, channel=%d\n", - (void *) msg, msg_number, ch->partid, ch->number); - - DBUG_ON((((u64) msg - (u64) ch->remote_msgqueue) / ch->msg_size) != - msg_number % ch->remote_nentries); - DBUG_ON(msg->flags & XPC_M_DONE); - - msg->flags |= XPC_M_DONE; - - /* - * The preceding store of msg->flags must occur before the following - * load of ch->local_GP->get. - */ - mb(); - - /* - * See if this message is next in line to be acknowledged as having - * been delivered. - */ - get = ch->local_GP->get; - if (get == msg_number) { - xpc_acknowledge_msgs(ch, get, msg->flags); - } - - /* the call to xpc_msgqueue_ref() was done by xpc_deliver_msg() */ - xpc_msgqueue_deref(ch); -} - |
