mcs_spinlock.h

 1/* SPDX-License-Identifier: GPL-2.0 */
 2#ifndef __ASM_MCS_LOCK_H
 3#define __ASM_MCS_LOCK_H
 4
 5#ifdef CONFIG_SMP
 6#include <asm/spinlock.h>
 7
 8/* MCS spin-locking. */
 9#define arch_mcs_spin_lock_contended(lock)				\
10do {									\
11	/* Ensure prior stores are observed before we enter wfe. */	\
12	smp_mb();							\
13	while (!(smp_load_acquire(lock)))				\
14		wfe();							\
15} while (0)								\
16
17#define arch_mcs_spin_unlock_contended(lock)				\
18do {									\
19	smp_store_release(lock, 1);					\
20	dsb_sev();							\
21} while (0)
22
23#endif	/* CONFIG_SMP */
24#endif	/* __ASM_MCS_LOCK_H */