From 4a6dae6d382e9edf3ff440b819e554ed706359bc Mon Sep 17 00:00:00 2001 From: Nick Piggin Date: Sun, 13 Nov 2005 16:07:24 -0800 Subject: [PATCH] atomic: cmpxchg Introduce an atomic_cmpxchg operation. Signed-off-by: Nick Piggin Cc: "Paul E. McKenney" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/asm-ia64/atomic.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/asm-ia64/atomic.h') diff --git a/include/asm-ia64/atomic.h b/include/asm-ia64/atomic.h index 874a6f890e75..593d3da9f3c2 100644 --- a/include/asm-ia64/atomic.h +++ b/include/asm-ia64/atomic.h @@ -88,6 +88,8 @@ ia64_atomic64_sub (__s64 i, atomic64_t *v) return new; } +#define atomic_cmpxchg(v, old, new) ((int)cmpxchg(&((v)->counter), old, new)) + #define atomic_add_return(i,v) \ ({ \ int __ia64_aar_i = (i); \ -- cgit v1.2.2 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-ia64/atomic.h | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'include/asm-ia64/atomic.h') diff --git a/include/asm-ia64/atomic.h b/include/asm-ia64/atomic.h index 593d3da9f3c2..2fbebf85c31d 100644 --- a/include/asm-ia64/atomic.h +++ b/include/asm-ia64/atomic.h @@ -90,6 +90,16 @@ ia64_atomic64_sub (__s64 i, atomic64_t *v) #define atomic_cmpxchg(v, old, new) ((int)cmpxchg(&((v)->counter), old, new)) +#define atomic_add_unless(v, a, u) \ +({ \ + int c, old; \ + c = atomic_read(v); \ + while (c != (u) && (old = atomic_cmpxchg((v), c, c + (a))) != c) \ + c = old; \ + c != (u); \ +}) +#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) + #define atomic_add_return(i,v) \ ({ \ int __ia64_aar_i = (i); \ -- cgit v1.2.2