xtensa: fix mb and wmb definitions
Define mb and wmb as memw to force memory barrier.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Chris Zankel <chris@zankel.net>
diff --git a/arch/xtensa/include/asm/barrier.h b/arch/xtensa/include/asm/barrier.h
index 55707a8..ef02167 100644
--- a/arch/xtensa/include/asm/barrier.h
+++ b/arch/xtensa/include/asm/barrier.h
@@ -3,7 +3,7 @@
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
- * Copyright (C) 2001 - 2005 Tensilica Inc.
+ * Copyright (C) 2001 - 2012 Tensilica Inc.
*/
#ifndef _XTENSA_SYSTEM_H
@@ -12,8 +12,8 @@
#define smp_read_barrier_depends() do { } while(0)
#define read_barrier_depends() do { } while(0)
-#define mb() barrier()
-#define rmb() mb()
+#define mb() ({ __asm__ __volatile__("memw" : : : "memory"); })
+#define rmb() barrier()
#define wmb() mb()
#ifdef CONFIG_SMP