From 8426e1f6af0fd7f44d040af7263750c5a52f3cc3 Mon Sep 17 00:00:00 2001 From: Nick Piggin Date: Sun, 13 Nov 2005 16:07:25 -0800 Subject: [PATCH] atomic: inc_not_zero Introduce an atomic_inc_not_zero operation. Make this a special case of atomic_add_unless because lockless pagecache actually wants atomic_inc_not_negativeone due to its offset refcount. Signed-off-by: Nick Piggin Cc: "Paul E. McKenney" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/asm-cris/atomic.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'include/asm-cris') diff --git a/include/asm-cris/atomic.h b/include/asm-cris/atomic.h index 45891f7d..683b05a 100644 --- a/include/asm-cris/atomic.h +++ b/include/asm-cris/atomic.h @@ -136,6 +136,20 @@ static inline int atomic_cmpxchg(atomic_t *v, int old, int new) return ret; } +static inline int atomic_add_unless(atomic_t *v, int a, int u) +{ + int ret; + unsigned long flags; + + cris_atomic_save(v, flags); + ret = v->counter; + if (ret != u) + v->counter += a; + cris_atomic_restore(v, flags); + return ret != u; +} +#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) + /* Atomic operations are already serializing */ #define smp_mb__before_atomic_dec() barrier() #define smp_mb__after_atomic_dec() barrier() -- cgit v1.1