From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-Id: <20090225150835.266333259@de.ibm.com> References: <20090225150622.529143164@de.ibm.com> Date: Wed, 25 Feb 2009 16:06:51 +0100 From: Martin Schwidefsky Subject: [patch/s390 29/46] cio: ensure single load of irq handler pointer Content-Disposition: inline; filename=128-cio-airq-barrier.diff Sender: linux-kernel-owner@vger.kernel.org List-Archive: List-Post: To: linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org Cc: Heiko Carstens , Martin Schwidefsky List-ID: From: Heiko Carstens Add barrier to prevent compiler from reloading pointer to irq handler. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky --- 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.