From 87fa5af80cdd5053b27a546725948c2b74ec82b2 Mon Sep 17 00:00:00 2001
From: Heiko Carstens <heiko.carstens@de.ibm.com>
Date: Thu, 26 Mar 2009 15:24:10 +0100
Subject: [PATCH] [S390] cio: ensure single load of irq handler pointer
Add barrier to prevent compiler from reloading pointer to irq handler.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
drivers/s390/cio/airq.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/s390/cio/airq.c b/drivers/s390/cio/airq.c
index fe6cea15bbaf..d3850dc30e42 100644
--- a/drivers/s390/cio/airq.c
+++ b/drivers/s390/cio/airq.c
@@ -133,6 +133,8 @@ void do_adapter_IO(u8 isc)
while (word) {
if (word & INDICATOR_MASK) {
airq = airqs[isc][i];
+ /* Make sure gcc reads from airqs only once. */
+ barrier();
if (likely(airq))
airq->handler(&indicators[isc].byte[i],
airq->drv_data);
--
2.20.1