From 82631f5dd114e52239fb3d1e270a49d37c088b46 Mon Sep 17 00:00:00 2001 From: Jeremy Kerr <jk@ozlabs.org> Date: Mon, 23 Mar 2009 16:55:08 +0000 Subject: [PATCH] powerpc: Add write barrier before enabling DTL flags Currently, we don't enforce any ordering for updates to the lppaca when enabling dtl logging, so we may end up enabling logging before the index fields have been established. This change adds a smp_wmb() before doing the actual enable. Signed-off-by: Jeremy Kerr <jk@ozlabs.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> --- arch/powerpc/platforms/pseries/dtl.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/powerpc/platforms/pseries/dtl.c b/arch/powerpc/platforms/pseries/dtl.c index dc9b0f81e60f94..fafcaa0e81ef59 100644 --- a/arch/powerpc/platforms/pseries/dtl.c +++ b/arch/powerpc/platforms/pseries/dtl.c @@ -107,6 +107,10 @@ static int dtl_enable(struct dtl *dtl) /* set our initial buffer indices */ dtl->last_idx = lppaca[dtl->cpu].dtl_idx = 0; + /* ensure that our updates to the lppaca fields have occurred before + * we actually enable the logging */ + smp_wmb(); + /* enable event logging */ lppaca[dtl->cpu].dtl_enable_mask = dtl_event_mask; -- GitLab