38 lines
914 B
C
38 lines
914 B
C
|
#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 */
|