mce_start() has an explicit smp_wmb to serialize writes to
global_nwo and mce_callin. However, atomic_inc_return() implies
barriers on both sides of the call, as such simply rely on this
full smp barrier.

Signed-off-by: Davidlohr Bueso <[email protected]>
---
 arch/x86/kernel/cpu/mcheck/mce.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index f0c921b03e42..6b7039c166b8 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -830,9 +830,9 @@ static int mce_start(int *no_way_out)
 
        atomic_add(*no_way_out, &global_nwo);
        /*
-        * global_nwo should be updated before mce_callin
+        * Rely on the implied barrier below, such that global_nwo
+        * is updated before mce_callin.
         */
-       smp_wmb();
        order = atomic_inc_return(&mce_callin);
 
        /*
-- 
2.1.4

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