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Diffstat (limited to 'arch/arm/include/asm/spinlock.h')
-rw-r--r--arch/arm/include/asm/spinlock.h19
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)