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| author | Nick Piggin <nickpiggin@yahoo.com.au> | 2005-11-14 03:07:25 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-11-14 05:14:16 +0300 |
| commit | 8426e1f6af0fd7f44d040af7263750c5a52f3cc3 (patch) | |
| tree | 827bd2588c2b73d11cea6869de8ff42dba134375 /arch/sparc/lib/atomic32.c | |
| parent | 4a6dae6d382e9edf3ff440b819e554ed706359bc (diff) | |
| download | linux-8426e1f6af0fd7f44d040af7263750c5a52f3cc3.tar.xz | |
[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 <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>
Diffstat (limited to 'arch/sparc/lib/atomic32.c')
| -rw-r--r-- | arch/sparc/lib/atomic32.c | 15 |
1 files changed, 15 insertions, 0 deletions
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; |