Quelle  mcs_spinlock.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ASM_MCS_LOCK_H
#define __ASM_MCS_LOCK_H

#ifdef CONFIG_SMP
#include <asm/spinlock.h>

/* MCS spin-locking. */
#define arch_mcs_spin_lock_contended(lock)    \
do {         \
 /* Ensure prior stores are observed before we enter wfe. */ \
 smp_mb();       \
 while (!(smp_load_acquire(lock)))    \
  wfe();       \
} while (0)        \

#define arch_mcs_spin_unlock_contended(lock)    \
do {         \
 smp_store_release(lock, 1);     \
 dsb_sev();       \
} while (0)

#endif /* CONFIG_SMP */
#endif /* __ASM_MCS_LOCK_H */