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)				\
10 do {									\
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)				\
18 do {									\
19 	smp_store_release(lock, 1);					\
20 	dsb_sev();							\
21 } while (0)
22 
23 #endif	/* CONFIG_SMP */
24 #endif	/* __ASM_MCS_LOCK_H */
25