[PATCH] mutex subsystem, add atomic_xchg() to all arches

add atomic_xchg() to all the architectures. Needed by the new mutex code.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@infradead.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/asm-arm/atomic.h b/include/asm-arm/atomic.h
index f72b63309bc5..3d7283d84405 100644
--- a/include/asm-arm/atomic.h
+++ b/include/asm-arm/atomic.h
@@ -175,6 +175,8 @@ static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr)
 
 #endif /* __LINUX_ARM_ARCH__ */
 
+#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
+
 static inline int atomic_add_unless(atomic_t *v, int a, int u)
 {
         int c, old;