1 files changed, 8 insertions, 1 deletions

diff --git a/arch/arc/include/asm/spinlock.h b/arch/arc/include/asm/spinlock.h
index f158197ac5b0..b6a8c2dfbe6e 100644
--- a/arch/arc/include/asm/spinlock.h
+++ b/arch/arc/include/asm/spinlock.h
@@ -45,7 +45,14 @@ static inline int arch_spin_trylock(arch_spinlock_t *lock)
 
 static inline void arch_spin_unlock(arch_spinlock_t *lock)
 {
-        lock->slock = __ARCH_SPIN_LOCK_UNLOCKED__;
+        unsigned int tmp = __ARCH_SPIN_LOCK_UNLOCKED__;
+
+        __asm__ __volatile__(
+        "       ex  %0, [%1]            \n"
+        : "+r" (tmp)
+        : "r"(&(lock->slock))
+        : "memory");
+
         smp_mb();
 }