diff options
Diffstat (limited to 'arch/arm/include/asm/spinlock.h')
| -rw-r--r-- | arch/arm/include/asm/spinlock.h | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/arch/arm/include/asm/spinlock.h b/arch/arm/include/asm/spinlock.h index 0fa418463f49..4bec45442072 100644 --- a/arch/arm/include/asm/spinlock.h +++ b/arch/arm/include/asm/spinlock.h @@ -6,6 +6,8 @@ #endif #include <linux/prefetch.h> +#include <asm/barrier.h> +#include <asm/processor.h> /* * sev and wfe are ARMv6K extensions. Uniprocessor ARMv6 may not have the K @@ -50,8 +52,21 @@ static inline void dsb_sev(void) * memory. */ -#define arch_spin_unlock_wait(lock) \ - do { while (arch_spin_is_locked(lock)) cpu_relax(); } while (0) +static inline void arch_spin_unlock_wait(arch_spinlock_t *lock) +{ + u16 owner = READ_ONCE(lock->tickets.owner); + + for (;;) { + arch_spinlock_t tmp = READ_ONCE(*lock); + + if (tmp.tickets.owner == tmp.tickets.next || + tmp.tickets.owner != owner) + break; + + wfe(); + } + smp_acquire__after_ctrl_dep(); +} #define arch_spin_lock_flags(lock, flags) arch_spin_lock(lock) |