diff options
author | Paul Mundt <lethal@linux-sh.org> | 2011-01-13 15:06:28 +0900 |
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committer | Paul Mundt <lethal@linux-sh.org> | 2011-01-13 15:06:28 +0900 |
commit | f43dc23d5ea91fca257be02138a255f02d98e806 (patch) | |
tree | b29722f6e965316e90ac97abf79923ced250dc21 /include/linux/atomic.h | |
parent | f8e53553f452dcbf67cb89c8cba63a1cd6eb4cc0 (diff) | |
parent | 4162cf64973df51fc885825bc9ca4d055891c49f (diff) |
Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6 into common/serial-rework
Conflicts:
arch/sh/kernel/cpu/sh2/setup-sh7619.c
arch/sh/kernel/cpu/sh2a/setup-mxg.c
arch/sh/kernel/cpu/sh2a/setup-sh7201.c
arch/sh/kernel/cpu/sh2a/setup-sh7203.c
arch/sh/kernel/cpu/sh2a/setup-sh7206.c
arch/sh/kernel/cpu/sh3/setup-sh7705.c
arch/sh/kernel/cpu/sh3/setup-sh770x.c
arch/sh/kernel/cpu/sh3/setup-sh7710.c
arch/sh/kernel/cpu/sh3/setup-sh7720.c
arch/sh/kernel/cpu/sh4/setup-sh4-202.c
arch/sh/kernel/cpu/sh4/setup-sh7750.c
arch/sh/kernel/cpu/sh4/setup-sh7760.c
arch/sh/kernel/cpu/sh4a/setup-sh7343.c
arch/sh/kernel/cpu/sh4a/setup-sh7366.c
arch/sh/kernel/cpu/sh4a/setup-sh7722.c
arch/sh/kernel/cpu/sh4a/setup-sh7723.c
arch/sh/kernel/cpu/sh4a/setup-sh7724.c
arch/sh/kernel/cpu/sh4a/setup-sh7763.c
arch/sh/kernel/cpu/sh4a/setup-sh7770.c
arch/sh/kernel/cpu/sh4a/setup-sh7780.c
arch/sh/kernel/cpu/sh4a/setup-sh7785.c
arch/sh/kernel/cpu/sh4a/setup-sh7786.c
arch/sh/kernel/cpu/sh4a/setup-shx3.c
arch/sh/kernel/cpu/sh5/setup-sh5.c
drivers/serial/sh-sci.c
drivers/serial/sh-sci.h
include/linux/serial_sci.h
Diffstat (limited to 'include/linux/atomic.h')
-rw-r--r-- | include/linux/atomic.h | 37 |
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 @@ +#ifndef _LINUX_ATOMIC_H +#define _LINUX_ATOMIC_H +#include <asm/atomic.h> + +/** + * atomic_inc_not_zero_hint - increment if not null + * @v: pointer of type atomic_t + * @hint: probable value of the atomic before the increment + * + * This version of atomic_inc_not_zero() gives a hint of probable + * value of the atomic. This helps processor to not read the memory + * before doing the atomic read/modify/write cycle, lowering + * number of bus transactions on some arches. + * + * Returns: 0 if increment was not done, 1 otherwise. + */ +#ifndef atomic_inc_not_zero_hint +static inline int atomic_inc_not_zero_hint(atomic_t *v, int hint) +{ + int val, c = hint; + + /* sanity test, should be removed by compiler if hint is a constant */ + if (!hint) + return atomic_inc_not_zero(v); + + do { + val = atomic_cmpxchg(v, c, c + 1); + if (val == c) + return 1; + c = val; + } while (c); + + return 0; +} +#endif + +#endif /* _LINUX_ATOMIC_H */ |