/*
* 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_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_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_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_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_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;
}
}
static int
xpc_kthread_start(void *args)
{
short partid = XPC_UNPACK_ARG1(args);
u16 ch_number = XPC_UNPACK_ARG2(args);
struct xpc_partition *part = &xpc_partitions[partid];
struct xpc_channel *ch;
int n_needed;
unsigned long irq_flags;
int (*n_of_deliverable_payloads) (struct xpc_channel *) =
xpc_arch_ops.n_of_deliverable_payloads;
dev_dbg(xpc_chan, "kthread starting, partid=%d, channel=%d\n",
partid, ch_number);
ch = &part->channels[ch_number];
if (!(ch->flags & XPC_C_DISCONNECTING)) {
/* */
spin_lock_irqsave(&ch->lock, irq_flags);
if (!(ch->flags & XPC_C_CONNECTEDCALLOUT)) {
ch->flags |= XPC_C_CONNECTEDCALLOUT;
spin_unlock_irqrestore(&ch->lock, irq_flags);
xpc_connected_callout(ch);
spin_lock_irqsave(&ch->lock, irq_flags);
ch->flags |= XPC_C_CONNECTEDCALLOUT_MADE;
spin_unlock_irqrestore(&ch->lock, irq_flags);
/*
*/
n_needed = n_of_deliverable_payloads(ch) - 1;
if (n_needed > 0 && !(ch->flags & XPC_C_DISCONNECTING))
xpc_activate_kthreads(ch, n_needed);
} else {
spin_unlock_irqrestore(&ch->lock, irq_flags);
}
xpc_kthread_waitmsgs(part, ch);
}
/* */
spin_lock_irqsave(&ch->lock, irq_flags);
if ((ch->flags & XPC_C_CONNECTEDCALLOUT_MADE) &&
!(ch->flags & XPC_C_DISCONNECTINGCALLOUT)) {
ch->flags |= XPC_C_DISCONNECTINGCALLOUT;
spin_unlock_irqrestore(&ch->lock, irq_flags);
xpc_disconnect_callout(ch, xpDisconnecting);
spin_lock_irqsave(&ch->lock, irq_flags);
ch->flags |= XPC_C_DISCONNECTINGCALLOUT_MADE;
}
spin_unlock_irqrestore(&ch->lock, irq_flags);
if (atomic_dec_return(&ch->kthreads_assigned) == 0 &&
atomic_dec_return(&part->nchannels_engaged) == 0) {
xpc_arch_ops.indicate_partition_disengaged(part);
}
xpc_msgqueue_deref(ch);
dev_dbg(xpc_chan, "kthread exiting, partid=%d, channel=%d\n",
partid, ch_number);
xpc_part_deref(part);
return 0;
}
static int
xpc_kthread_start(void *args)
{
short partid = XPC_UNPACK_ARG1(args);
u16 ch_number = XPC_UNPACK_ARG2(args);
struct xpc_partition *part = &xpc_partitions[partid];
struct xpc_channel *ch;
int n_needed;
unsigned long irq_flags;
dev_dbg(xpc_chan, "kthread starting, partid=%d, channel=%d\n",
partid, ch_number);
ch = &part->channels[ch_number];
if (!(ch->flags & XPC_C_DISCONNECTING)) {
/* let registerer know that connection has been established */
spin_lock_irqsave(&ch->lock, irq_flags);
if (!(ch->flags & XPC_C_CONNECTEDCALLOUT)) {
ch->flags |= XPC_C_CONNECTEDCALLOUT;
spin_unlock_irqrestore(&ch->lock, irq_flags);
xpc_connected_callout(ch);
spin_lock_irqsave(&ch->lock, irq_flags);
ch->flags |= XPC_C_CONNECTEDCALLOUT_MADE;
spin_unlock_irqrestore(&ch->lock, irq_flags);
/*
* It is possible that while the callout was being
* made that the remote partition sent some messages.
* If that is the case, we may need to activate
* additional kthreads to help deliver them. We only
* need one less than total #of messages to deliver.
*/
n_needed = xpc_n_of_deliverable_payloads(ch) - 1;
if (n_needed > 0 && !(ch->flags & XPC_C_DISCONNECTING))
xpc_activate_kthreads(ch, n_needed);
} else {
spin_unlock_irqrestore(&ch->lock, irq_flags);
}
xpc_kthread_waitmsgs(part, ch);
}
/* let registerer know that connection is disconnecting */
spin_lock_irqsave(&ch->lock, irq_flags);
if ((ch->flags & XPC_C_CONNECTEDCALLOUT_MADE) &&
!(ch->flags & XPC_C_DISCONNECTINGCALLOUT)) {
ch->flags |= XPC_C_DISCONNECTINGCALLOUT;
spin_unlock_irqrestore(&ch->lock, irq_flags);
xpc_disconnect_callout(ch, xpDisconnecting);
spin_lock_irqsave(&ch->lock, irq_flags);
ch->flags |= XPC_C_DISCONNECTINGCALLOUT_MADE;
}
spin_unlock_irqrestore(&ch->lock, irq_flags);
if (atomic_dec_return(&ch->kthreads_assigned) == 0 &&
atomic_dec_return(&part->nchannels_engaged) == 0) {
xpc_indicate_partition_disengaged(part);
}
xpc_msgqueue_deref(ch);
dev_dbg(xpc_chan, "kthread exiting, partid=%d, channel=%d\n",
partid, ch_number);
xpc_part_deref(part);
return 0;
}
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));
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) {
if (xpc_arch_ops.partition_engaged(ch->partid))
return;
} else {
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;
}
if (atomic_read(&ch->n_to_notify) > 0) {
xpc_arch_ops.notify_senders_of_disconnect(ch);
}
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);
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;
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) {
complete(&ch->wdisconnect_wait);
} else if (ch->delayed_chctl_flags) {
if (part->act_state != XPC_P_AS_DEACTIVATING) {
spin_lock(&part->chctl_lock);
part->chctl.flags[ch->number] |=
ch->delayed_chctl_flags;
spin_unlock(&part->chctl_lock);
}
ch->delayed_chctl_flags = 0;
}
}
