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Diffstat (limited to 'kernel/include/asm-generic/bitops/lock.h')
-rw-r--r--kernel/include/asm-generic/bitops/lock.h14
1 files changed, 7 insertions, 7 deletions
diff --git a/kernel/include/asm-generic/bitops/lock.h b/kernel/include/asm-generic/bitops/lock.h
index c30266e94..8ef0ccbf8 100644
--- a/kernel/include/asm-generic/bitops/lock.h
+++ b/kernel/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_ */