Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu

Pull RCU cleanup from Paul E. McKenney:

 "Privatize smp_mb__after_unlock_lock().  This commit moves the
  definition of smp_mb__after_unlock_lock() to kernel/rcu/tree.h,
  in recognition of the fact that RCU is the only thing using
  this, that nothing else is likely to use it, and that it is
  likely to go away completely."

Signed-off-by: Ingo Molnar <mingo@kernel.org>

kernel/rcu/tree.h

@@ -653,3 +653,15 @@ static inline void rcu_nocb_q_lengths(struct rcu_data *rdp, long *ql, long *qll)
 #endif /* #else #ifdef CONFIG_RCU_NOCB_CPU */
 }
 #endif /* #ifdef CONFIG_RCU_TRACE */
+
+/*
+ * 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.
+ */
+#ifdef CONFIG_PPC
+#define smp_mb__after_unlock_lock()	smp_mb()  /* Full ordering for lock. */
+#else /* #ifdef CONFIG_PPC */
+#define smp_mb__after_unlock_lock()	do { } while (0)
+#endif /* #else #ifdef CONFIG_PPC */