[mirror_ubuntu-bionic-kernel.git] / include / asm-generic / bitops / lock.h

/* SPDX-License-Identifier: GPL-2.0 */
#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_ */
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
26333576 NP	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 { \
4e857c58	24	smp_mb__before_atomic(); \
26333576 NP	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	*
f75d4864 PZ	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.
26333576 NP	38	*/
	39	#define __clear_bit_unlock(nr, addr) \
	40	do { \
f75d4864 PZ	41	smp_mb__before_atomic(); \
f75d4864 PZ	42	clear_bit(nr, addr); \
26333576 NP	43	} while (0)
	44
	45	#endif /* _ASM_GENERIC_BITOPS_LOCK_H_ */
	46