sgi-xpc: ensure flags are updated before bte_copy
The clearing of the msg->flags needs a barrier between it and the notify
of the channel threads that the messages are cleaned and ready for use.
Signed-off-by: Robin Holt <holt@sgi.com>
Signed-off-by: Dean Nelson <dcn@sgi.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/misc/sgi-xp/xpc_sn2.c b/drivers/misc/sgi-xp/xpc_sn2.c
index 82fb995..7aafb8a 100644
--- a/drivers/misc/sgi-xp/xpc_sn2.c
+++ b/drivers/misc/sgi-xp/xpc_sn2.c
@@ -1836,6 +1836,7 @@
*/
xpc_clear_remote_msgqueue_flags_sn2(ch);
+ smp_wmb(); /* ensure flags have been cleared before bte_copy */
ch_sn2->w_remote_GP.put = ch_sn2->remote_GP.put;
dev_dbg(xpc_chan, "w_remote_GP.put changed to %ld, partid=%d, "
@@ -1934,7 +1935,7 @@
break;
get = ch_sn2->w_local_GP.get;
- rmb(); /* guarantee that .get loads before .put */
+ smp_rmb(); /* guarantee that .get loads before .put */
if (get == ch_sn2->w_remote_GP.put)
break;
@@ -2053,7 +2054,7 @@
while (1) {
put = ch_sn2->w_local_GP.put;
- rmb(); /* guarantee that .put loads before .get */
+ smp_rmb(); /* guarantee that .put loads before .get */
if (put - ch_sn2->w_remote_GP.get < ch->local_nentries) {
/* There are available message entries. We need to try
@@ -2186,7 +2187,7 @@
* The preceding store of msg->flags must occur before the following
* load of local_GP->put.
*/
- mb();
+ smp_mb();
/* see if the message is next in line to be sent, if so send it */
@@ -2287,7 +2288,7 @@
* The preceding store of msg->flags must occur before the following
* load of local_GP->get.
*/
- mb();
+ smp_mb();
/*
* See if this message is next in line to be acknowledged as having
diff --git a/drivers/misc/sgi-xp/xpc_uv.c b/drivers/misc/sgi-xp/xpc_uv.c
index 91a55b1..f17f7d4 100644
--- a/drivers/misc/sgi-xp/xpc_uv.c
+++ b/drivers/misc/sgi-xp/xpc_uv.c
@@ -1423,7 +1423,7 @@
atomic_inc(&ch->n_to_notify);
msg_slot->key = key;
- wmb(); /* a non-NULL func must hit memory after the key */
+ smp_wmb(); /* a non-NULL func must hit memory after the key */
msg_slot->func = func;
if (ch->flags & XPC_C_DISCONNECTING) {