diff mbox

[kvm-unit-tests,v7,07/11] io: Disallow memory re-ordering for generic memory barriers

Message ID 6e277749a4e0ad3ad9d00224cf063afa47057c5e.1462457467.git.agordeev@redhat.com (mailing list archive)
State New, archived
Headers show

Commit Message

Alexander Gordeev May 5, 2016, 2:26 p.m. UTC 
Suggested-by: Thomas Huth <thuth@redhat.com>
Cc: Andrew Jones <drjones@redhat.com>
Cc: Thomas Huth <thuth@redhat.com>
Cc: Radim Kr?má? <rkrcmar@redhat.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
---
 lib/asm-generic/io.h | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)
diff mbox

Patch

diff --git a/lib/asm-generic/io.h b/lib/asm-generic/io.h
index 3585ac0..1834720 100644
--- a/lib/asm-generic/io.h
+++ b/lib/asm-generic/io.h
@@ -127,11 +127,14 @@  static inline u64 __bswap64(u64 x)
 	({ u64 __r = !__cpu_is_be() ? __bswap64(x) : ((u64)x); __r; })
 #define cpu_to_be64 be64_to_cpu
 
+#ifndef mb
+#define mb()	asm volatile("":::"memory")
+#endif
 #ifndef rmb
-#define rmb() do { } while (0)
+#define rmb()	asm volatile("":::"memory")
 #endif
 #ifndef wmb
-#define wmb() do { } while (0)
+#define wmb()	asm volatile("":::"memory")
 #endif
 
 #define readb(addr) \