#define smp_mb__before_spinlock() smp_wmb()
#endif
+/*
+ * Place this after a lock-acquisition primitive to guarantee that
+ * an UNLOCK+LOCK pair act as a full barrier. This guarantee applies
+ * if the UNLOCK and LOCK are executed by the same CPU or if the
+ * UNLOCK and LOCK operate on the same lock variable.
+ */
+#ifndef smp_mb__after_unlock_lock
+#define smp_mb__after_unlock_lock() do { } while (0)
+#endif
+
/**
* raw_spin_unlock_wait - wait until the spinlock gets unlocked
* @lock: the spinlock in question.