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![Lance Roy](/assets/img/avatar_default.png)
lockdep_assert_held() is better suited to checking locking requirements, since it won't get confused when someone else holds the lock. This is also a step towards possibly removing spin_is_locked(). Signed-off-by: Lance Roy <ldr709@gmail.com> Cc: Cliff Whickman <cpw@sgi.com> Cc: Arnd Bergmann <arnd@arndb.de> Acked-by: Robin Holt <robinmholt@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1011 lines
28 KiB
C
1011 lines
28 KiB
C
/*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (c) 2004-2009 Silicon Graphics, Inc. All Rights Reserved.
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*/
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/*
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* Cross Partition Communication (XPC) channel support.
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*
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* This is the part of XPC that manages the channels and
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* sends/receives messages across them to/from other partitions.
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*
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*/
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#include <linux/device.h>
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#include "xpc.h"
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/*
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* Process a connect message from a remote partition.
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*
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* Note: xpc_process_connect() is expecting to be called with the
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* spin_lock_irqsave held and will leave it locked upon return.
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*/
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static void
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xpc_process_connect(struct xpc_channel *ch, unsigned long *irq_flags)
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{
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enum xp_retval ret;
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lockdep_assert_held(&ch->lock);
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if (!(ch->flags & XPC_C_OPENREQUEST) ||
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!(ch->flags & XPC_C_ROPENREQUEST)) {
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/* nothing more to do for now */
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return;
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}
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DBUG_ON(!(ch->flags & XPC_C_CONNECTING));
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if (!(ch->flags & XPC_C_SETUP)) {
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spin_unlock_irqrestore(&ch->lock, *irq_flags);
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ret = xpc_arch_ops.setup_msg_structures(ch);
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spin_lock_irqsave(&ch->lock, *irq_flags);
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if (ret != xpSuccess)
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XPC_DISCONNECT_CHANNEL(ch, ret, irq_flags);
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else
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ch->flags |= XPC_C_SETUP;
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if (ch->flags & XPC_C_DISCONNECTING)
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return;
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}
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if (!(ch->flags & XPC_C_OPENREPLY)) {
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ch->flags |= XPC_C_OPENREPLY;
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xpc_arch_ops.send_chctl_openreply(ch, irq_flags);
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}
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if (!(ch->flags & XPC_C_ROPENREPLY))
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return;
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if (!(ch->flags & XPC_C_OPENCOMPLETE)) {
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ch->flags |= (XPC_C_OPENCOMPLETE | XPC_C_CONNECTED);
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xpc_arch_ops.send_chctl_opencomplete(ch, irq_flags);
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}
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if (!(ch->flags & XPC_C_ROPENCOMPLETE))
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return;
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dev_info(xpc_chan, "channel %d to partition %d connected\n",
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ch->number, ch->partid);
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ch->flags = (XPC_C_CONNECTED | XPC_C_SETUP); /* clear all else */
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}
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/*
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* spin_lock_irqsave() is expected to be held on entry.
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*/
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static void
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xpc_process_disconnect(struct xpc_channel *ch, unsigned long *irq_flags)
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{
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struct xpc_partition *part = &xpc_partitions[ch->partid];
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u32 channel_was_connected = (ch->flags & XPC_C_WASCONNECTED);
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lockdep_assert_held(&ch->lock);
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if (!(ch->flags & XPC_C_DISCONNECTING))
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return;
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DBUG_ON(!(ch->flags & XPC_C_CLOSEREQUEST));
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/* make sure all activity has settled down first */
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if (atomic_read(&ch->kthreads_assigned) > 0 ||
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atomic_read(&ch->references) > 0) {
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return;
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}
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DBUG_ON((ch->flags & XPC_C_CONNECTEDCALLOUT_MADE) &&
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!(ch->flags & XPC_C_DISCONNECTINGCALLOUT_MADE));
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if (part->act_state == XPC_P_AS_DEACTIVATING) {
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/* can't proceed until the other side disengages from us */
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if (xpc_arch_ops.partition_engaged(ch->partid))
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return;
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} else {
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/* as long as the other side is up do the full protocol */
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if (!(ch->flags & XPC_C_RCLOSEREQUEST))
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return;
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if (!(ch->flags & XPC_C_CLOSEREPLY)) {
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ch->flags |= XPC_C_CLOSEREPLY;
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xpc_arch_ops.send_chctl_closereply(ch, irq_flags);
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}
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if (!(ch->flags & XPC_C_RCLOSEREPLY))
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return;
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}
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/* wake those waiting for notify completion */
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if (atomic_read(&ch->n_to_notify) > 0) {
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/* we do callout while holding ch->lock, callout can't block */
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xpc_arch_ops.notify_senders_of_disconnect(ch);
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}
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/* both sides are disconnected now */
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if (ch->flags & XPC_C_DISCONNECTINGCALLOUT_MADE) {
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spin_unlock_irqrestore(&ch->lock, *irq_flags);
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xpc_disconnect_callout(ch, xpDisconnected);
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spin_lock_irqsave(&ch->lock, *irq_flags);
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}
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DBUG_ON(atomic_read(&ch->n_to_notify) != 0);
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/* it's now safe to free the channel's message queues */
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xpc_arch_ops.teardown_msg_structures(ch);
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ch->func = NULL;
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ch->key = NULL;
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ch->entry_size = 0;
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ch->local_nentries = 0;
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ch->remote_nentries = 0;
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ch->kthreads_assigned_limit = 0;
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ch->kthreads_idle_limit = 0;
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/*
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* Mark the channel disconnected and clear all other flags, including
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* XPC_C_SETUP (because of call to
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* xpc_arch_ops.teardown_msg_structures()) but not including
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* XPC_C_WDISCONNECT (if it was set).
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*/
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ch->flags = (XPC_C_DISCONNECTED | (ch->flags & XPC_C_WDISCONNECT));
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atomic_dec(&part->nchannels_active);
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if (channel_was_connected) {
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dev_info(xpc_chan, "channel %d to partition %d disconnected, "
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"reason=%d\n", ch->number, ch->partid, ch->reason);
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}
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if (ch->flags & XPC_C_WDISCONNECT) {
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/* we won't lose the CPU since we're holding ch->lock */
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complete(&ch->wdisconnect_wait);
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} else if (ch->delayed_chctl_flags) {
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if (part->act_state != XPC_P_AS_DEACTIVATING) {
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/* time to take action on any delayed chctl flags */
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spin_lock(&part->chctl_lock);
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part->chctl.flags[ch->number] |=
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ch->delayed_chctl_flags;
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spin_unlock(&part->chctl_lock);
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}
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ch->delayed_chctl_flags = 0;
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}
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}
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/*
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* Process a change in the channel's remote connection state.
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*/
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static void
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xpc_process_openclose_chctl_flags(struct xpc_partition *part, int ch_number,
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u8 chctl_flags)
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{
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unsigned long irq_flags;
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struct xpc_openclose_args *args =
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&part->remote_openclose_args[ch_number];
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struct xpc_channel *ch = &part->channels[ch_number];
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enum xp_retval reason;
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enum xp_retval ret;
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int create_kthread = 0;
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spin_lock_irqsave(&ch->lock, irq_flags);
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again:
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if ((ch->flags & XPC_C_DISCONNECTED) &&
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(ch->flags & XPC_C_WDISCONNECT)) {
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/*
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* Delay processing chctl flags until thread waiting disconnect
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* has had a chance to see that the channel is disconnected.
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*/
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ch->delayed_chctl_flags |= chctl_flags;
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goto out;
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}
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if (chctl_flags & XPC_CHCTL_CLOSEREQUEST) {
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dev_dbg(xpc_chan, "XPC_CHCTL_CLOSEREQUEST (reason=%d) received "
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"from partid=%d, channel=%d\n", args->reason,
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ch->partid, ch->number);
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/*
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* If RCLOSEREQUEST is set, we're probably waiting for
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* RCLOSEREPLY. We should find it and a ROPENREQUEST packed
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* with this RCLOSEREQUEST in the chctl_flags.
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*/
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if (ch->flags & XPC_C_RCLOSEREQUEST) {
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DBUG_ON(!(ch->flags & XPC_C_DISCONNECTING));
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DBUG_ON(!(ch->flags & XPC_C_CLOSEREQUEST));
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DBUG_ON(!(ch->flags & XPC_C_CLOSEREPLY));
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DBUG_ON(ch->flags & XPC_C_RCLOSEREPLY);
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DBUG_ON(!(chctl_flags & XPC_CHCTL_CLOSEREPLY));
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chctl_flags &= ~XPC_CHCTL_CLOSEREPLY;
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ch->flags |= XPC_C_RCLOSEREPLY;
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/* both sides have finished disconnecting */
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xpc_process_disconnect(ch, &irq_flags);
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DBUG_ON(!(ch->flags & XPC_C_DISCONNECTED));
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goto again;
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}
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if (ch->flags & XPC_C_DISCONNECTED) {
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if (!(chctl_flags & XPC_CHCTL_OPENREQUEST)) {
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if (part->chctl.flags[ch_number] &
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XPC_CHCTL_OPENREQUEST) {
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DBUG_ON(ch->delayed_chctl_flags != 0);
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spin_lock(&part->chctl_lock);
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part->chctl.flags[ch_number] |=
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XPC_CHCTL_CLOSEREQUEST;
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spin_unlock(&part->chctl_lock);
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}
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goto out;
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}
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XPC_SET_REASON(ch, 0, 0);
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ch->flags &= ~XPC_C_DISCONNECTED;
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atomic_inc(&part->nchannels_active);
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ch->flags |= (XPC_C_CONNECTING | XPC_C_ROPENREQUEST);
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}
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chctl_flags &= ~(XPC_CHCTL_OPENREQUEST | XPC_CHCTL_OPENREPLY |
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XPC_CHCTL_OPENCOMPLETE);
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/*
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* The meaningful CLOSEREQUEST connection state fields are:
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* reason = reason connection is to be closed
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*/
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ch->flags |= XPC_C_RCLOSEREQUEST;
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if (!(ch->flags & XPC_C_DISCONNECTING)) {
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reason = args->reason;
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if (reason <= xpSuccess || reason > xpUnknownReason)
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reason = xpUnknownReason;
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else if (reason == xpUnregistering)
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reason = xpOtherUnregistering;
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XPC_DISCONNECT_CHANNEL(ch, reason, &irq_flags);
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DBUG_ON(chctl_flags & XPC_CHCTL_CLOSEREPLY);
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goto out;
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}
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xpc_process_disconnect(ch, &irq_flags);
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}
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if (chctl_flags & XPC_CHCTL_CLOSEREPLY) {
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dev_dbg(xpc_chan, "XPC_CHCTL_CLOSEREPLY received from partid="
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"%d, channel=%d\n", ch->partid, ch->number);
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if (ch->flags & XPC_C_DISCONNECTED) {
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DBUG_ON(part->act_state != XPC_P_AS_DEACTIVATING);
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goto out;
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}
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DBUG_ON(!(ch->flags & XPC_C_CLOSEREQUEST));
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if (!(ch->flags & XPC_C_RCLOSEREQUEST)) {
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if (part->chctl.flags[ch_number] &
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XPC_CHCTL_CLOSEREQUEST) {
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DBUG_ON(ch->delayed_chctl_flags != 0);
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spin_lock(&part->chctl_lock);
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part->chctl.flags[ch_number] |=
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XPC_CHCTL_CLOSEREPLY;
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spin_unlock(&part->chctl_lock);
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}
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goto out;
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}
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ch->flags |= XPC_C_RCLOSEREPLY;
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if (ch->flags & XPC_C_CLOSEREPLY) {
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/* both sides have finished disconnecting */
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xpc_process_disconnect(ch, &irq_flags);
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}
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}
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if (chctl_flags & XPC_CHCTL_OPENREQUEST) {
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dev_dbg(xpc_chan, "XPC_CHCTL_OPENREQUEST (entry_size=%d, "
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"local_nentries=%d) received from partid=%d, "
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"channel=%d\n", args->entry_size, args->local_nentries,
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ch->partid, ch->number);
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if (part->act_state == XPC_P_AS_DEACTIVATING ||
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(ch->flags & XPC_C_ROPENREQUEST)) {
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goto out;
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}
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if (ch->flags & (XPC_C_DISCONNECTING | XPC_C_WDISCONNECT)) {
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ch->delayed_chctl_flags |= XPC_CHCTL_OPENREQUEST;
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goto out;
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}
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DBUG_ON(!(ch->flags & (XPC_C_DISCONNECTED |
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XPC_C_OPENREQUEST)));
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DBUG_ON(ch->flags & (XPC_C_ROPENREQUEST | XPC_C_ROPENREPLY |
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XPC_C_OPENREPLY | XPC_C_CONNECTED));
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|
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/*
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* The meaningful OPENREQUEST connection state fields are:
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* entry_size = size of channel's messages in bytes
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* local_nentries = remote partition's local_nentries
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*/
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if (args->entry_size == 0 || args->local_nentries == 0) {
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/* assume OPENREQUEST was delayed by mistake */
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goto out;
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}
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ch->flags |= (XPC_C_ROPENREQUEST | XPC_C_CONNECTING);
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ch->remote_nentries = args->local_nentries;
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|
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if (ch->flags & XPC_C_OPENREQUEST) {
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if (args->entry_size != ch->entry_size) {
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XPC_DISCONNECT_CHANNEL(ch, xpUnequalMsgSizes,
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&irq_flags);
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goto out;
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}
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} else {
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ch->entry_size = args->entry_size;
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|
|
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XPC_SET_REASON(ch, 0, 0);
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ch->flags &= ~XPC_C_DISCONNECTED;
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|
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atomic_inc(&part->nchannels_active);
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}
|
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|
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xpc_process_connect(ch, &irq_flags);
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}
|
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if (chctl_flags & XPC_CHCTL_OPENREPLY) {
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|
|
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dev_dbg(xpc_chan, "XPC_CHCTL_OPENREPLY (local_msgqueue_pa="
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"0x%lx, local_nentries=%d, remote_nentries=%d) "
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"received from partid=%d, channel=%d\n",
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args->local_msgqueue_pa, args->local_nentries,
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args->remote_nentries, ch->partid, ch->number);
|
|
|
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if (ch->flags & (XPC_C_DISCONNECTING | XPC_C_DISCONNECTED))
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goto out;
|
|
|
|
if (!(ch->flags & XPC_C_OPENREQUEST)) {
|
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XPC_DISCONNECT_CHANNEL(ch, xpOpenCloseError,
|
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&irq_flags);
|
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goto out;
|
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}
|
|
|
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DBUG_ON(!(ch->flags & XPC_C_ROPENREQUEST));
|
|
DBUG_ON(ch->flags & XPC_C_CONNECTED);
|
|
|
|
/*
|
|
* The meaningful OPENREPLY connection state fields are:
|
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* local_msgqueue_pa = physical address of remote
|
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* partition's local_msgqueue
|
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* local_nentries = remote partition's local_nentries
|
|
* remote_nentries = remote partition's remote_nentries
|
|
*/
|
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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",
|
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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;
|
|
|
|
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)) {
|
|
/*
|
|
* 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);
|
|
|
|
lockdep_assert_held(&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;
|
|
DEFINE_WAIT(wait);
|
|
|
|
if (ch->flags & XPC_C_DISCONNECTING) {
|
|
DBUG_ON(ch->reason == xpInterrupted);
|
|
return ch->reason;
|
|
}
|
|
|
|
atomic_inc(&ch->n_on_msg_allocate_wq);
|
|
prepare_to_wait(&ch->msg_allocate_wq, &wait, TASK_INTERRUPTIBLE);
|
|
ret = schedule_timeout(1);
|
|
finish_wait(&ch->msg_allocate_wq, &wait);
|
|
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);
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|
DBUG_ON(ch_number < 0 || ch_number >= part->nchannels);
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|
|
|
ch = &part->channels[ch_number];
|
|
xpc_arch_ops.received_payload(ch, payload);
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|
|
|
/* the call to xpc_msgqueue_ref() was done by xpc_deliver_payload() */
|
|
xpc_msgqueue_deref(ch);
|
|
}
|