| /* |
| * 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) 2004-2009 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/device.h> |
| #include "xpc.h" |
| |
| /* |
| * 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 xp_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_arch_ops.setup_msg_structures(ch); |
| spin_lock_irqsave(&ch->lock, *irq_flags); |
| |
| if (ret != xpSuccess) |
| XPC_DISCONNECT_CHANNEL(ch, ret, irq_flags); |
| else |
| ch->flags |= XPC_C_SETUP; |
| |
| if (ch->flags & XPC_C_DISCONNECTING) |
| return; |
| } |
| |
| if (!(ch->flags & XPC_C_OPENREPLY)) { |
| ch->flags |= XPC_C_OPENREPLY; |
| xpc_arch_ops.send_chctl_openreply(ch, irq_flags); |
| } |
| |
| if (!(ch->flags & XPC_C_ROPENREPLY)) |
| return; |
| |
| if (!(ch->flags & XPC_C_OPENCOMPLETE)) { |
| ch->flags |= (XPC_C_OPENCOMPLETE | XPC_C_CONNECTED); |
| xpc_arch_ops.send_chctl_opencomplete(ch, irq_flags); |
| } |
| |
| if (!(ch->flags & XPC_C_ROPENCOMPLETE)) |
| return; |
| |
| dev_info(xpc_chan, "channel %d to partition %d connected\n", |
| ch->number, ch->partid); |
| |
| ch->flags = (XPC_C_CONNECTED | XPC_C_SETUP); /* clear all else */ |
| } |
| |
| /* |
| * 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_AS_DEACTIVATING) { |
| /* can't proceed until the other side disengages from us */ |
| if (xpc_arch_ops.partition_engaged(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_arch_ops.send_chctl_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, callout can't block */ |
| xpc_arch_ops.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, 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_arch_ops.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 the channel disconnected and clear all other flags, including |
| * XPC_C_SETUP (because of call to |
| * xpc_arch_ops.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); |
| |
| 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_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_chctl_flags = 0; |
| } |
| } |
| |
| /* |
| * Process a change in the channel's remote connection state. |
| */ |
| static void |
| 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 xp_retval reason; |
| enum xp_retval ret; |
| int create_kthread = 0; |
| |
| spin_lock_irqsave(&ch->lock, irq_flags); |
| |
| again: |
| |
| if ((ch->flags & XPC_C_DISCONNECTED) && |
| (ch->flags & XPC_C_WDISCONNECT)) { |
| /* |
| * Delay processing chctl flags until thread waiting disconnect |
| * has had a chance to see that the channel is disconnected. |
| */ |
| ch->delayed_chctl_flags |= chctl_flags; |
| goto out; |
| } |
| |
| if (chctl_flags & XPC_CHCTL_CLOSEREQUEST) { |
| |
| 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 chctl_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(!(chctl_flags & XPC_CHCTL_CLOSEREPLY)); |
| chctl_flags &= ~XPC_CHCTL_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 (!(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); |
| } |
| goto out; |
| } |
| |
| XPC_SET_REASON(ch, 0, 0); |
| ch->flags &= ~XPC_C_DISCONNECTED; |
| |
| atomic_inc(&part->nchannels_active); |
| ch->flags |= (XPC_C_CONNECTING | XPC_C_ROPENREQUEST); |
| } |
| |
| chctl_flags &= ~(XPC_CHCTL_OPENREQUEST | XPC_CHCTL_OPENREPLY | |
| XPC_CHCTL_OPENCOMPLETE); |
| |
| /* |
| * 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 <= xpSuccess || reason > xpUnknownReason) |
| reason = xpUnknownReason; |
| else if (reason == xpUnregistering) |
| reason = xpOtherUnregistering; |
| |
| XPC_DISCONNECT_CHANNEL(ch, reason, &irq_flags); |
| |
| DBUG_ON(chctl_flags & XPC_CHCTL_CLOSEREPLY); |
| goto out; |
| } |
| |
| xpc_process_disconnect(ch, &irq_flags); |
| } |
| |
| if (chctl_flags & XPC_CHCTL_CLOSEREPLY) { |
| |
| 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_AS_DEACTIVATING); |
| goto out; |
| } |
| |
| DBUG_ON(!(ch->flags & XPC_C_CLOSEREQUEST)); |
| |
| if (!(ch->flags & XPC_C_RCLOSEREQUEST)) { |
| 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); |
| } |
| goto out; |
| } |
| |
| ch->flags |= XPC_C_RCLOSEREPLY; |
| |
| if (ch->flags & XPC_C_CLOSEREPLY) { |
| /* both sides have finished disconnecting */ |
| xpc_process_disconnect(ch, &irq_flags); |
| } |
| } |
| |
| if (chctl_flags & XPC_CHCTL_OPENREQUEST) { |
| |
| dev_dbg(xpc_chan, "XPC_CHCTL_OPENREQUEST (entry_size=%d, " |
| "local_nentries=%d) received from partid=%d, " |
| "channel=%d\n", args->entry_size, args->local_nentries, |
| ch->partid, ch->number); |
| |
| if (part->act_state == XPC_P_AS_DEACTIVATING || |
| (ch->flags & XPC_C_ROPENREQUEST)) { |
| goto out; |
| } |
| |
| if (ch->flags & (XPC_C_DISCONNECTING | XPC_C_WDISCONNECT)) { |
| ch->delayed_chctl_flags |= XPC_CHCTL_OPENREQUEST; |
| goto out; |
| } |
| 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: |
| * entry_size = size of channel's messages in bytes |
| * local_nentries = remote partition's local_nentries |
| */ |
| if (args->entry_size == 0 || args->local_nentries == 0) { |
| /* assume OPENREQUEST was delayed by mistake */ |
| goto out; |
| } |
| |
| ch->flags |= (XPC_C_ROPENREQUEST | XPC_C_CONNECTING); |
| ch->remote_nentries = args->local_nentries; |
| |
| if (ch->flags & XPC_C_OPENREQUEST) { |
| if (args->entry_size != ch->entry_size) { |
| XPC_DISCONNECT_CHANNEL(ch, xpUnequalMsgSizes, |
| &irq_flags); |
| goto out; |
| } |
| } else { |
| ch->entry_size = args->entry_size; |
| |
| XPC_SET_REASON(ch, 0, 0); |
| ch->flags &= ~XPC_C_DISCONNECTED; |
| |
| atomic_inc(&part->nchannels_active); |
| } |
| |
| xpc_process_connect(ch, &irq_flags); |
| } |
| |
| if (chctl_flags & XPC_CHCTL_OPENREPLY) { |
| |
| 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)) |
| goto out; |
| |
| if (!(ch->flags & XPC_C_OPENREQUEST)) { |
| XPC_DISCONNECT_CHANNEL(ch, xpOpenCloseError, |
| &irq_flags); |
| goto out; |
| } |
| |
| 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); |
| |
| ret = xpc_arch_ops.save_remote_msgqueue_pa(ch, |
| args->local_msgqueue_pa); |
| if (ret != xpSuccess) { |
| XPC_DISCONNECT_CHANNEL(ch, ret, &irq_flags); |
| goto out; |
| } |
| ch->flags |= XPC_C_ROPENREPLY; |
| |
| if (args->local_nentries < ch->remote_nentries) { |
| 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, |
| ch->partid, ch->number); |
| |
| ch->remote_nentries = args->local_nentries; |
| } |
| if (args->remote_nentries < ch->local_nentries) { |
| 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, |
| ch->partid, ch->number); |
| |
| ch->local_nentries = args->remote_nentries; |
| } |
| |
| xpc_process_connect(ch, &irq_flags); |
| } |
| |
| if (chctl_flags & XPC_CHCTL_OPENCOMPLETE) { |
| |
| dev_dbg(xpc_chan, "XPC_CHCTL_OPENCOMPLETE received from " |
| "partid=%d, channel=%d\n", ch->partid, ch->number); |
| |
| if (ch->flags & (XPC_C_DISCONNECTING | XPC_C_DISCONNECTED)) |
| goto out; |
| |
| if (!(ch->flags & XPC_C_OPENREQUEST) || |
| !(ch->flags & XPC_C_OPENREPLY)) { |
| XPC_DISCONNECT_CHANNEL(ch, xpOpenCloseError, |
| &irq_flags); |
| goto out; |
| } |
| |
| DBUG_ON(!(ch->flags & XPC_C_ROPENREQUEST)); |
| DBUG_ON(!(ch->flags & XPC_C_ROPENREPLY)); |
| DBUG_ON(!(ch->flags & XPC_C_CONNECTED)); |
| |
| ch->flags |= XPC_C_ROPENCOMPLETE; |
| |
| xpc_process_connect(ch, &irq_flags); |
| create_kthread = 1; |
| } |
| |
| out: |
| spin_unlock_irqrestore(&ch->lock, irq_flags); |
| |
| if (create_kthread) |
| xpc_create_kthreads(ch, 1, 0); |
| } |
| |
| /* |
| * Attempt to establish a channel connection to a remote partition. |
| */ |
| 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(®istration->mutex) == 0) |
| return xpRetry; |
| |
| if (!XPC_CHANNEL_REGISTERED(ch->number)) { |
| mutex_unlock(®istration->mutex); |
| return xpUnregistered; |
| } |
| |
| 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->entry_size != ch->entry_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, xpUnequalMsgSizes, |
| &irq_flags); |
| spin_unlock_irqrestore(&ch->lock, irq_flags); |
| return xpUnequalMsgSizes; |
| } |
| } else { |
| ch->entry_size = registration->entry_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_arch_ops.send_chctl_openrequest(ch, &irq_flags); |
| |
| xpc_process_connect(ch, &irq_flags); |
| |
| spin_unlock_irqrestore(&ch->lock, irq_flags); |
| |
| return xpSuccess; |
| } |
| |
| void |
| xpc_process_sent_chctl_flags(struct xpc_partition *part) |
| { |
| unsigned long irq_flags; |
| union xpc_channel_ctl_flags chctl; |
| struct xpc_channel *ch; |
| int ch_number; |
| u32 ch_flags; |
| |
| chctl.all_flags = xpc_arch_ops.get_chctl_all_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 chctl flags, and then deal |
| * with connecting or disconnecting the channel as required. |
| */ |
| |
| 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 */ |
| |
| 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_AS_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); |
| } |
| continue; |
| } |
| |
| /* |
| * Process any message related chctl flags, this may involve |
| * the activation of kthreads to deliver any pending messages |
| * sent from the other partition. |
| */ |
| |
| if (chctl.flags[ch_number] & XPC_MSG_CHCTL_FLAGS) |
| xpc_arch_ops.process_msg_chctl_flags(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 xp_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); |
| } |
| |
| /* |
| * 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) |
| { |
| short partid; |
| struct xpc_partition *part; |
| struct xpc_channel *ch; |
| |
| DBUG_ON(ch_number < 0 || ch_number >= XPC_MAX_NCHANNELS); |
| |
| for (partid = 0; partid < xp_max_npartitions; 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=xpConnected, " |
| "partid=%d, channel=%d\n", 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=xpConnected, " |
| "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; |
| short partid; |
| struct xpc_partition *part; |
| struct xpc_channel *ch; |
| |
| DBUG_ON(ch_number < 0 || ch_number >= XPC_MAX_NCHANNELS); |
| |
| /* initiate the channel disconnect for every active partition */ |
| for (partid = 0; partid < xp_max_npartitions; 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, xpUnregistering, |
| &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 xp_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_arch_ops.send_chctl_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 xpDisconnecting 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 xp_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. |
| */ |
| enum xp_retval |
| xpc_allocate_msg_wait(struct xpc_channel *ch) |
| { |
| enum xp_retval ret; |
| |
| if (ch->flags & XPC_C_DISCONNECTING) { |
| DBUG_ON(ch->reason == xpInterrupted); |
| 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 == xpInterrupted); |
| } else if (ret == 0) { |
| ret = xpTimeout; |
| } else { |
| ret = xpInterrupted; |
| } |
| |
| return ret; |
| } |
| |
| /* |
| * Send a message that contains the user's payload on the specified channel |
| * connected to the specified partition. |
| * |
| * NOTE that this routine can sleep waiting for a message entry to become |
| * available. To not sleep, pass in the XPC_NOWAIT flag. |
| * |
| * 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. |
| * flags - see xp.h for valid flags. |
| * payload - pointer to the payload which is to be sent. |
| * payload_size - size of the payload in bytes. |
| */ |
| enum xp_retval |
| xpc_initiate_send(short partid, int ch_number, u32 flags, void *payload, |
| u16 payload_size) |
| { |
| struct xpc_partition *part = &xpc_partitions[partid]; |
| enum xp_retval ret = xpUnknownReason; |
| |
| dev_dbg(xpc_chan, "payload=0x%p, partid=%d, channel=%d\n", payload, |
| partid, ch_number); |
| |
| DBUG_ON(partid < 0 || partid >= xp_max_npartitions); |
| DBUG_ON(ch_number < 0 || ch_number >= part->nchannels); |
| DBUG_ON(payload == NULL); |
| |
| if (xpc_part_ref(part)) { |
| ret = xpc_arch_ops.send_payload(&part->channels[ch_number], |
| flags, payload, payload_size, 0, NULL, NULL); |
| xpc_part_deref(part); |
| } |
| |
| return ret; |
| } |
| |
| /* |
| * Send a message that contains the user's payload on the specified channel |
| * connected to the specified partition. |
| * |
| * 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 |
| * 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. |
| * |
| * Arguments: |
| * |
| * partid - ID of partition to which the channel is connected. |
| * ch_number - channel # to send message on. |
| * flags - see xp.h for valid flags. |
| * payload - pointer to the payload which is to be sent. |
| * payload_size - size of the payload in bytes. |
| * func - function to call with asynchronous notification of message |
| * receipt. THIS FUNCTION MUST BE NON-BLOCKING. |
| * key - user-defined key to be passed to the function when it's called. |
| */ |
| enum xp_retval |
| xpc_initiate_send_notify(short partid, int ch_number, u32 flags, void *payload, |
| u16 payload_size, xpc_notify_func func, void *key) |
| { |
| struct xpc_partition *part = &xpc_partitions[partid]; |
| enum xp_retval ret = xpUnknownReason; |
| |
| dev_dbg(xpc_chan, "payload=0x%p, partid=%d, channel=%d\n", payload, |
| partid, ch_number); |
| |
| DBUG_ON(partid < 0 || partid >= xp_max_npartitions); |
| DBUG_ON(ch_number < 0 || ch_number >= part->nchannels); |
| DBUG_ON(payload == NULL); |
| DBUG_ON(func == NULL); |
| |
| if (xpc_part_ref(part)) { |
| ret = xpc_arch_ops.send_payload(&part->channels[ch_number], |
| flags, payload, payload_size, XPC_N_CALL, func, key); |
| xpc_part_deref(part); |
| } |
| return ret; |
| } |
| |
| /* |
| * Deliver a message's payload to its intended recipient. |
| */ |
| void |
| xpc_deliver_payload(struct xpc_channel *ch) |
| { |
| void *payload; |
| |
| payload = xpc_arch_ops.get_deliverable_payload(ch); |
| if (payload != 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, payload=0x%p " |
| "partid=%d channel=%d\n", payload, ch->partid, |
| ch->number); |
| |
| /* deliver the message to its intended recipient */ |
| ch->func(xpMsgReceived, ch->partid, ch->number, payload, |
| ch->key); |
| |
| dev_dbg(xpc_chan, "ch->func() returned, payload=0x%p " |
| "partid=%d channel=%d\n", payload, ch->partid, |
| ch->number); |
| } |
| |
| atomic_dec(&ch->kthreads_active); |
| } |
| } |
| |
| /* |
| * 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_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_send() or xpc_initiate_send_notify(). |
| */ |
| void |
| xpc_initiate_received(short partid, int ch_number, void *payload) |
| { |
| struct xpc_partition *part = &xpc_partitions[partid]; |
| struct xpc_channel *ch; |
| |
| DBUG_ON(partid < 0 || partid >= xp_max_npartitions); |
| DBUG_ON(ch_number < 0 || ch_number >= part->nchannels); |
| |
| ch = &part->channels[ch_number]; |
| xpc_arch_ops.received_payload(ch, payload); |
| |
| /* the call to xpc_msgqueue_ref() was done by xpc_deliver_payload() */ |
| xpc_msgqueue_deref(ch); |
| } |