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Subject[patch/s390 29/46] cio: ensure single load of irq handler pointer
From: Heiko Carstens <heiko.carstens@de.ibm.com>

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(+)
Index: quilt-2.6/drivers/s390/cio/airq.c
===================================================================
--- quilt-2.6.orig/drivers/s390/cio/airq.c
+++ quilt-2.6/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);
--
blue skies,
Martin.

"Reality continues to ruin my life." - Calvin.



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