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authorPatrick McHardy <kaber@trash.net>2011-01-14 08:12:37 -0500
committerPatrick McHardy <kaber@trash.net>2011-01-14 08:12:37 -0500
commit0134e89c7bcc9fde1da962c82a120691e185619f (patch)
tree3e03335cf001019a2687d161e956de4f73379984 /include/linux/atomic.h
parentc7066f70d9610df0b9406cc635fc09e86136e714 (diff)
parent6faee60a4e82075853a437831768cc9e2e563e4e (diff)
Merge branch 'master' of git://1984.lsi.us.es/net-next-2.6
Conflicts: net/ipv4/route.c Signed-off-by: Patrick McHardy <kaber@trash.net>
Diffstat (limited to 'include/linux/atomic.h')
-rw-r--r--include/linux/atomic.h37
1 files changed, 37 insertions, 0 deletions
diff --git a/include/linux/atomic.h b/include/linux/atomic.h
new file mode 100644
index 000000000000..96c038e43d66
--- /dev/null
+++ b/include/linux/atomic.h
@@ -0,0 +1,37 @@
1#ifndef _LINUX_ATOMIC_H
2#define _LINUX_ATOMIC_H
3#include <asm/atomic.h>
4
5/**
6 * atomic_inc_not_zero_hint - increment if not null
7 * @v: pointer of type atomic_t
8 * @hint: probable value of the atomic before the increment
9 *
10 * This version of atomic_inc_not_zero() gives a hint of probable
11 * value of the atomic. This helps processor to not read the memory
12 * before doing the atomic read/modify/write cycle, lowering
13 * number of bus transactions on some arches.
14 *
15 * Returns: 0 if increment was not done, 1 otherwise.
16 */
17#ifndef atomic_inc_not_zero_hint
18static inline int atomic_inc_not_zero_hint(atomic_t *v, int hint)
19{
20 int val, c = hint;
21
22 /* sanity test, should be removed by compiler if hint is a constant */
23 if (!hint)
24 return atomic_inc_not_zero(v);
25
26 do {
27 val = atomic_cmpxchg(v, c, c + 1);
28 if (val == c)
29 return 1;
30 c = val;
31 } while (c);
32
33 return 0;
34}
35#endif
36
37#endif /* _LINUX_ATOMIC_H */