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| author | Alex Shi <alex.shi@linaro.org> | 2016-05-05 13:36:03 +0800 |
|---|---|---|
| committer | Alex Shi <alex.shi@linaro.org> | 2016-05-05 13:36:03 +0800 |
| commit | e91b1cc90283c1b9b75670b027a18afbd20fe070 (patch) | |
| tree | 81c395406a3774775a183d544aee9c5ced1c31d6 /include/asm-generic/bitops/lock.h | |
| parent | d83731cf53fd3af7173cab5e3f573d06ebc852be (diff) | |
| parent | 0b3df30dcadcddc56aed56c3c2d2de2ca963e81d (diff) | |
Merge branch 'linux-linaro-lsk-v4.1' into linux-linaro-lsk-v4.1-rtlsk-v4.1-16.06-rtlsk-v4.1-16.05-rt
Diffstat (limited to 'include/asm-generic/bitops/lock.h')
| -rw-r--r-- | include/asm-generic/bitops/lock.h | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/include/asm-generic/bitops/lock.h b/include/asm-generic/bitops/lock.h index c30266e94806..8ef0ccbf8167 100644 --- a/include/asm-generic/bitops/lock.h +++ b/include/asm-generic/bitops/lock.h @@ -29,16 +29,16 @@ do { \ * @nr: the bit to set * @addr: the address to start counting from * - * This operation is like clear_bit_unlock, however it is not atomic. - * It does provide release barrier semantics so it can be used to unlock - * a bit lock, however it would only be used if no other CPU can modify - * any bits in the memory until the lock is released (a good example is - * if the bit lock itself protects access to the other bits in the word). + * A weaker form of clear_bit_unlock() as used by __bit_lock_unlock(). If all + * the bits in the word are protected by this lock some archs can use weaker + * ops to safely unlock. + * + * See for example x86's implementation. */ #define __clear_bit_unlock(nr, addr) \ do { \ - smp_mb(); \ - __clear_bit(nr, addr); \ + smp_mb__before_atomic(); \ + clear_bit(nr, addr); \ } while (0) #endif /* _ASM_GENERIC_BITOPS_LOCK_H_ */ |