[IA64-SGI] enforce proper ordering of callouts by XPC
Fix XPC so that it does not deliver any messages until the connected
callout has returned, as well as, prevent the disconnected callout to
occur before the disconnecting callout has returned.
Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
diff --git a/arch/ia64/sn/kernel/xpc_channel.c b/arch/ia64/sn/kernel/xpc_channel.c
index 36e5437..cdf6856 100644
--- a/arch/ia64/sn/kernel/xpc_channel.c
+++ b/arch/ia64/sn/kernel/xpc_channel.c
@@ -738,7 +738,9 @@
/* make sure all activity has settled down first */
- if (atomic_read(&ch->references) > 0) {
+ if (atomic_read(&ch->references) > 0 ||
+ ((ch->flags & XPC_C_CONNECTEDCALLOUT_MADE) &&
+ !(ch->flags & XPC_C_DISCONNECTINGCALLOUT_MADE))) {
return;
}
DBUG_ON(atomic_read(&ch->kthreads_assigned) != 0);
@@ -775,7 +777,7 @@
/* both sides are disconnected now */
- if (ch->flags & XPC_C_CONNECTCALLOUT) {
+ 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);
@@ -1300,7 +1302,7 @@
"delivered=%d, partid=%d, channel=%d\n",
nmsgs_sent, ch->partid, ch->number);
- if (ch->flags & XPC_C_CONNECTCALLOUT) {
+ if (ch->flags & XPC_C_CONNECTEDCALLOUT_MADE) {
xpc_activate_kthreads(ch, nmsgs_sent);
}
}
diff --git a/arch/ia64/sn/kernel/xpc_main.c b/arch/ia64/sn/kernel/xpc_main.c
index 9cd460d..8cbf164 100644
--- a/arch/ia64/sn/kernel/xpc_main.c
+++ b/arch/ia64/sn/kernel/xpc_main.c
@@ -750,12 +750,16 @@
/* let registerer know that connection has been established */
spin_lock_irqsave(&ch->lock, irq_flags);
- if (!(ch->flags & XPC_C_CONNECTCALLOUT)) {
- ch->flags |= XPC_C_CONNECTCALLOUT;
+ 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.
@@ -777,15 +781,17 @@
if (atomic_dec_return(&ch->kthreads_assigned) == 0) {
spin_lock_irqsave(&ch->lock, irq_flags);
- if ((ch->flags & XPC_C_CONNECTCALLOUT) &&
- !(ch->flags & XPC_C_DISCONNECTCALLOUT)) {
- ch->flags |= XPC_C_DISCONNECTCALLOUT;
+ 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, xpcDisconnecting);
- } else {
- spin_unlock_irqrestore(&ch->lock, irq_flags);
+
+ spin_lock_irqsave(&ch->lock, irq_flags);
+ ch->flags |= XPC_C_DISCONNECTINGCALLOUT_MADE;
}
+ spin_unlock_irqrestore(&ch->lock, irq_flags);
if (atomic_dec_return(&part->nchannels_engaged) == 0) {
xpc_mark_partition_disengaged(part);
xpc_IPI_send_disengage(part);
diff --git a/include/asm-ia64/sn/xpc.h b/include/asm-ia64/sn/xpc.h
index 0c36928..df7f5f4 100644
--- a/include/asm-ia64/sn/xpc.h
+++ b/include/asm-ia64/sn/xpc.h
@@ -508,19 +508,24 @@
#define XPC_C_OPENREQUEST 0x00000010 /* local open channel request */
#define XPC_C_SETUP 0x00000020 /* channel's msgqueues are alloc'd */
-#define XPC_C_CONNECTCALLOUT 0x00000040 /* channel connected callout made */
-#define XPC_C_CONNECTED 0x00000080 /* local channel is connected */
-#define XPC_C_CONNECTING 0x00000100 /* channel is being connected */
+#define XPC_C_CONNECTEDCALLOUT 0x00000040 /* connected callout initiated */
+#define XPC_C_CONNECTEDCALLOUT_MADE \
+ 0x00000080 /* connected callout completed */
+#define XPC_C_CONNECTED 0x00000100 /* local channel is connected */
+#define XPC_C_CONNECTING 0x00000200 /* channel is being connected */
-#define XPC_C_RCLOSEREPLY 0x00000200 /* remote close channel reply */
-#define XPC_C_CLOSEREPLY 0x00000400 /* local close channel reply */
-#define XPC_C_RCLOSEREQUEST 0x00000800 /* remote close channel request */
-#define XPC_C_CLOSEREQUEST 0x00001000 /* local close channel request */
+#define XPC_C_RCLOSEREPLY 0x00000400 /* remote close channel reply */
+#define XPC_C_CLOSEREPLY 0x00000800 /* local close channel reply */
+#define XPC_C_RCLOSEREQUEST 0x00001000 /* remote close channel request */
+#define XPC_C_CLOSEREQUEST 0x00002000 /* local close channel request */
-#define XPC_C_DISCONNECTED 0x00002000 /* channel is disconnected */
-#define XPC_C_DISCONNECTING 0x00004000 /* channel is being disconnected */
-#define XPC_C_DISCONNECTCALLOUT 0x00008000 /* chan disconnected callout made */
-#define XPC_C_WDISCONNECT 0x00010000 /* waiting for channel disconnect */
+#define XPC_C_DISCONNECTED 0x00004000 /* channel is disconnected */
+#define XPC_C_DISCONNECTING 0x00008000 /* channel is being disconnected */
+#define XPC_C_DISCONNECTINGCALLOUT \
+ 0x00010000 /* disconnecting callout initiated */
+#define XPC_C_DISCONNECTINGCALLOUT_MADE \
+ 0x00020000 /* disconnecting callout completed */
+#define XPC_C_WDISCONNECT 0x00040000 /* waiting for channel disconnect */