1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_GENERIC_BITOPS_LOCK_H_
3 #define _ASM_GENERIC_BITOPS_LOCK_H_
4 
5 /**
6  * test_and_set_bit_lock - Set a bit and return its old value, for lock
7  * @nr: Bit to set
8  * @addr: Address to count from
9  *
10  * This operation is atomic and provides acquire barrier semantics.
11  * It can be used to implement bit locks.
12  */
13 #define test_and_set_bit_lock(nr, addr)	test_and_set_bit(nr, addr)
14 
15 /**
16  * clear_bit_unlock - Clear a bit in memory, for unlock
17  * @nr: the bit to set
18  * @addr: the address to start counting from
19  *
20  * This operation is atomic and provides release barrier semantics.
21  */
22 #define clear_bit_unlock(nr, addr)	\
23 do {					\
24 	smp_mb__before_atomic();	\
25 	clear_bit(nr, addr);		\
26 } while (0)
27 
28 /**
29  * __clear_bit_unlock - Clear a bit in memory, for unlock
30  * @nr: the bit to set
31  * @addr: the address to start counting from
32  *
33  * A weaker form of clear_bit_unlock() as used by __bit_lock_unlock(). If all
34  * the bits in the word are protected by this lock some archs can use weaker
35  * ops to safely unlock.
36  *
37  * See for example x86's implementation.
38  */
39 #define __clear_bit_unlock(nr, addr)	\
40 do {					\
41 	smp_mb__before_atomic();	\
42 	clear_bit(nr, addr);		\
43 } while (0)
44 
45 #endif /* _ASM_GENERIC_BITOPS_LOCK_H_ */
46 
47