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