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-sparc/atomic.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/asm-sparc') diff --git a/include/asm-sparc/atomic.h b/include/asm-sparc/atomic.h index 52bdd1a895fa..62bec7ad271c 100644 --- a/include/asm-sparc/atomic.h +++ b/include/asm-sparc/atomic.h @@ -20,6 +20,7 @@ typedef struct { volatile int counter; } atomic_t; extern int __atomic_add_return(int, atomic_t *); extern int atomic_cmpxchg(atomic_t *, int, int); +extern int atomic_add_unless(atomic_t *, int, int); extern void atomic_set(atomic_t *, int); #define atomic_read(v) ((v)->counter) @@ -49,6 +50,8 @@ extern void atomic_set(atomic_t *, int); #define atomic_dec_and_test(v) (atomic_dec_return(v) == 0) #define atomic_sub_and_test(i, v) (atomic_sub_return(i, v) == 0) +#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) + /* This is the old 24-bit implementation. It's still used internally * by some sparc-specific code, notably the semaphore implementation. */ -- cgit v1.2.2