[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, 1 insertions, 0 deletions

diff --git a/include/asm-ia64/atomic.h b/include/asm-ia64/atomic.h
index 15cf7984c48e..d3e0dfa99e1f 100644
--- a/include/asm-ia64/atomic.h
+++ b/include/asm-ia64/atomic.h
@@ -89,6 +89,7 @@ ia64_atomic64_sub (__s64 i, atomic64_t *v)
 }
 
 #define atomic_cmpxchg(v, old, new) ((int)cmpxchg(&((v)->counter), old, new))
+#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
 
 #define atomic_add_unless(v, a, u)                              \
 ({                                                              \