46 lines
1.2 KiB
C
46 lines
1.2 KiB
C
#ifndef _ASM_GENERIC_BITOPS_LOCK_H_
|
|
#define _ASM_GENERIC_BITOPS_LOCK_H_
|
|
|
|
/**
|
|
* test_and_set_bit_lock - Set a bit and return its old value, for lock
|
|
* @nr: Bit to set
|
|
* @addr: Address to count from
|
|
*
|
|
* This operation is atomic and provides acquire barrier semantics.
|
|
* It can be used to implement bit locks.
|
|
*/
|
|
#define test_and_set_bit_lock(nr, addr) test_and_set_bit(nr, addr)
|
|
|
|
/**
|
|
* clear_bit_unlock - Clear a bit in memory, for unlock
|
|
* @nr: the bit to set
|
|
* @addr: the address to start counting from
|
|
*
|
|
* This operation is atomic and provides release barrier semantics.
|
|
*/
|
|
#define clear_bit_unlock(nr, addr) \
|
|
do { \
|
|
smp_mb__before_atomic(); \
|
|
clear_bit(nr, addr); \
|
|
} while (0)
|
|
|
|
/**
|
|
* __clear_bit_unlock - Clear a bit in memory, for unlock
|
|
* @nr: the bit to set
|
|
* @addr: the address to start counting from
|
|
*
|
|
* 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__before_atomic(); \
|
|
clear_bit(nr, addr); \
|
|
} while (0)
|
|
|
|
#endif /* _ASM_GENERIC_BITOPS_LOCK_H_ */
|
|
|