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 --- arch/sparc/lib/atomic32.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'arch/sparc/lib') diff --git a/arch/sparc/lib/atomic32.c b/arch/sparc/lib/atomic32.c index be46f6545184..cb3cf0f22822 100644 --- a/arch/sparc/lib/atomic32.c +++ b/arch/sparc/lib/atomic32.c @@ -53,6 +53,21 @@ int atomic_cmpxchg(atomic_t *v, int old, int new) return ret; } +int atomic_add_unless(atomic_t *v, int a, int u) +{ + int ret; + unsigned long flags; + + spin_lock_irqsave(ATOMIC_HASH(v), flags); + ret = v->counter; + if (ret != u) + v->counter += a; + spin_unlock_irqrestore(ATOMIC_HASH(v), flags); + return ret != u; +} + +static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr) +/* Atomic operations are already serializing */ void atomic_set(atomic_t *v, int i) { unsigned long flags; -- cgit v1.2.2