Merge branch 'core/xen' into x86/urgent

3 files changed, 24 insertions, 17 deletions

diff --git a/drivers/misc/sgi-xp/xpc_channel.c b/drivers/misc/sgi-xp/xpc_channel.c
index 9cd2ebe2a3b..45fd653dbe3 100644
--- a/drivers/misc/sgi-xp/xpc_channel.c
+++ b/drivers/misc/sgi-xp/xpc_channel.c
@@ -49,9 +49,6 @@ xpc_process_connect(struct xpc_channel *ch, unsigned long *irq_flags)
 
 		if (ch->flags & (XPC_C_CONNECTED | XPC_C_DISCONNECTING))
 			return;
-
-		DBUG_ON(ch->local_msgqueue == NULL);
-		DBUG_ON(ch->remote_msgqueue == NULL);
 	}
 
 	if (!(ch->flags & XPC_C_OPENREPLY)) {
diff --git a/drivers/misc/sgi-xp/xpc_sn2.c b/drivers/misc/sgi-xp/xpc_sn2.c
index 73b7fb8de47..2e975762c32 100644
--- a/drivers/misc/sgi-xp/xpc_sn2.c
+++ b/drivers/misc/sgi-xp/xpc_sn2.c
@@ -899,7 +899,7 @@ xpc_update_partition_info_sn2(struct xpc_partition *part, u8 remote_rp_version,
 	dev_dbg(xpc_part, "  remote_vars_pa = 0x%016lx\n",
 		part_sn2->remote_vars_pa);
 
-	part->last_heartbeat = remote_vars->heartbeat;
+	part->last_heartbeat = remote_vars->heartbeat - 1;
 	dev_dbg(xpc_part, "  last_heartbeat = 0x%016lx\n",
 		part->last_heartbeat);
 
@@ -1106,8 +1106,6 @@ xpc_process_activate_IRQ_rcvd_sn2(void)
 	int n_IRQs_expected;
 	int n_IRQs_detected;
 
-	DBUG_ON(xpc_activate_IRQ_rcvd == 0);
-
 	spin_lock_irqsave(&xpc_activate_IRQ_rcvd_lock, irq_flags);
 	n_IRQs_expected = xpc_activate_IRQ_rcvd;
 	xpc_activate_IRQ_rcvd = 0;
@@ -1726,6 +1724,7 @@ xpc_clear_local_msgqueue_flags_sn2(struct xpc_channel *ch)
 		msg = (struct xpc_msg_sn2 *)((u64)ch_sn2->local_msgqueue +
 					     (get % ch->local_nentries) *
 					     ch->entry_size);
+		DBUG_ON(!(msg->flags & XPC_M_SN2_READY));
 		msg->flags = 0;
 	} while (++get < ch_sn2->remote_GP.get);
 }
@@ -1740,11 +1739,18 @@ xpc_clear_remote_msgqueue_flags_sn2(struct xpc_channel *ch)
 	struct xpc_msg_sn2 *msg;
 	s64 put;
 
-	put = ch_sn2->w_remote_GP.put;
+	/* flags are zeroed when the buffer is allocated */
+	if (ch_sn2->remote_GP.put < ch->remote_nentries)
+		return;
+
+	put = max(ch_sn2->w_remote_GP.put, ch->remote_nentries);
 	do {
 		msg = (struct xpc_msg_sn2 *)((u64)ch_sn2->remote_msgqueue +
 					     (put % ch->remote_nentries) *
 					     ch->entry_size);
+		DBUG_ON(!(msg->flags & XPC_M_SN2_READY));
+		DBUG_ON(!(msg->flags & XPC_M_SN2_DONE));
+		DBUG_ON(msg->number != put - ch->remote_nentries);
 		msg->flags = 0;
 	} while (++put < ch_sn2->remote_GP.put);
 }
@@ -1836,6 +1842,7 @@ xpc_process_msg_chctl_flags_sn2(struct xpc_partition *part, int ch_number)
 		 */
 		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 +1941,7 @@ xpc_get_deliverable_payload_sn2(struct xpc_channel *ch)
 			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;
 
@@ -1956,11 +1963,13 @@ xpc_get_deliverable_payload_sn2(struct xpc_channel *ch)
 
 			msg = xpc_pull_remote_msg_sn2(ch, get);
 
-			DBUG_ON(msg != NULL && msg->number != get);
-			DBUG_ON(msg != NULL && (msg->flags & XPC_M_SN2_DONE));
-			DBUG_ON(msg != NULL && !(msg->flags & XPC_M_SN2_READY));
+			if (msg != NULL) {
+				DBUG_ON(msg->number != get);
+				DBUG_ON(msg->flags & XPC_M_SN2_DONE);
+				DBUG_ON(!(msg->flags & XPC_M_SN2_READY));
 
-			payload = &msg->payload;
+				payload = &msg->payload;
+			}
 			break;
 		}
 
@@ -2053,7 +2062,7 @@ xpc_allocate_msg_sn2(struct xpc_channel *ch, u32 flags,
 	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 +2195,7 @@ xpc_send_payload_sn2(struct xpc_channel *ch, u32 flags, void *payload,
 	 * 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 */
 
@@ -2277,8 +2286,9 @@ xpc_received_payload_sn2(struct xpc_channel *ch, void *payload)
 	dev_dbg(xpc_chan, "msg=0x%p, msg_number=%ld, partid=%d, channel=%d\n",
 		(void *)msg, msg_number, ch->partid, ch->number);
 
-	DBUG_ON((((u64)msg - (u64)ch->remote_msgqueue) / ch->entry_size) !=
+	DBUG_ON((((u64)msg - (u64)ch->sn.sn2.remote_msgqueue) / ch->entry_size) !=
 		msg_number % ch->remote_nentries);
+	DBUG_ON(!(msg->flags & XPC_M_SN2_READY));
 	DBUG_ON(msg->flags & XPC_M_SN2_DONE);
 
 	msg->flags |= XPC_M_SN2_DONE;
@@ -2287,7 +2297,7 @@ xpc_received_payload_sn2(struct xpc_channel *ch, void *payload)
 	 * 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 91a55b1b103..f17f7d40ea2 100644
--- a/drivers/misc/sgi-xp/xpc_uv.c
+++ b/drivers/misc/sgi-xp/xpc_uv.c
@@ -1423,7 +1423,7 @@ xpc_send_payload_uv(struct xpc_channel *ch, u32 flags, void *payload,
 		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) {