diff options
Diffstat (limited to 'include/linux/wait_bit.h')
| -rw-r--r-- | include/linux/wait_bit.h | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/include/linux/wait_bit.h b/include/linux/wait_bit.h index af0d495430d7..bc96d90bcafd 100644 --- a/include/linux/wait_bit.h +++ b/include/linux/wait_bit.h @@ -259,4 +259,21 @@ int wait_on_atomic_t(atomic_t *val, int (*action)(atomic_t *), unsigned mode) return out_of_line_wait_on_atomic_t(val, action, mode); } +/** + * clear_and_wake_up_bit - clear a bit and wake up anyone waiting on that bit + * + * @bit: the bit of the word being waited on + * @word: the word being waited on, a kernel virtual address + * + * You can use this helper if bitflags are manipulated atomically rather than + * non-atomically under a lock. + */ +static inline void clear_and_wake_up_bit(int bit, void *word) +{ + clear_bit_unlock(bit, word); + /* See wake_up_bit() for which memory barrier you need to use. */ + smp_mb__after_atomic(); + wake_up_bit(word, bit); +} + #endif /* _LINUX_WAIT_BIT_H */ |