x86: smp_mb__{before,after}_clear_bit() are no-ops.

Signed-off-by: Keir Fraser <keir.fraser@citrix.com>

diff --git a/xen/include/asm-x86/bitops.h b/xen/include/asm-x86/bitops.h
index d3664e3d4c580ab5cd3d791d337ac699f21663c1..8237381f81a48ef8c2046077fc6b53bdf3a26732 100644 (file)
--- a/xen/include/asm-x86/bitops.h
+++ b/xen/include/asm-x86/bitops.h
@@ -116,8 +116,8 @@ static inline void __clear_bit(int nr, volatile void *addr)
     __clear_bit(nr, addr);                              \
 })
 
-#define smp_mb__before_clear_bit() barrier()
-#define smp_mb__after_clear_bit()  barrier()
+#define smp_mb__before_clear_bit() ((void)0)
+#define smp_mb__after_clear_bit()  ((void)0)
 
 /**
  * __change_bit - Toggle a bit in memory