[PATCH] atomic: cmpxchg

Introduce an atomic_cmpxchg operation.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Nick Piggin
2005-11-13 16:07:24 -08:00
committed by Linus Torvalds
parent 53e86b91b7
commit 4a6dae6d38
23 changed files with 169 additions and 5 deletions

View File

@ -139,6 +139,8 @@ static inline void atomic_set_mask(unsigned long mask, unsigned long *v)
__asm__ __volatile__("orl %1,%0" : "+m" (*v) : "id" (mask));
}
#define atomic_cmpxchg(v, o, n) ((int)cmpxchg(&((v)->counter), (o), (n)))
/* Atomic operations are already serializing */
#define smp_mb__before_atomic_dec() barrier()
#define smp_mb__after_atomic_dec() barrier()