mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-23 20:53:53 +08:00
46 lines
1.3 KiB
C
46 lines
1.3 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_clear_bit(); \
|
||
|
|
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
|
||
|
|
*
|
||
|
|
* 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).
|
||
|
|
*/
|
||
|
|
#define __clear_bit_unlock(nr, addr) \
|
||
|
|
do { \
|
||
|
|
smp_mb(); \
|
||
|
|
__clear_bit(nr, addr); \
|
||
|
|
} while (0)
|
||
|
|
|
||
|
|
#endif /* _ASM_GENERIC_BITOPS_LOCK_H_ */
|
||
|
|
|