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authorJeremy Kerr <jk@ozlabs.org>2009-03-23 16:55:08 +0000
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2009-03-27 16:58:23 +1100
commit82631f5dd114e52239fb3d1e270a49d37c088b46 (patch)
treec56dd87c9659864f5a3bc5068c0cb877c39bc705 /arch/powerpc/platforms/pseries
parent757c74d298dc8438760b8dea275c4c6e0ac8a77f (diff)
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>
Diffstat (limited to 'arch/powerpc/platforms/pseries')
-rw-r--r--arch/powerpc/platforms/pseries/dtl.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/pseries/dtl.c b/arch/powerpc/platforms/pseries/dtl.c
index dc9b0f81e60..fafcaa0e81e 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;