locking: Clean up pvqspinlock warning

 - Rename the on-stack variable to match the datastructure variable,

 - place the cmpxchg back under the comment that explains it,

 - clean up the WARN() statement to avoid superfluous conditionals
   and line-breaks.

Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Paul E. McKenney <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Waiman Long <[email protected]>
Cc: [email protected]
Signed-off-by: Ingo Molnar <[email protected]>

1 files changed, 7 insertions, 6 deletions

diff --git a/kernel/locking/qspinlock_paravirt.h b/kernel/locking/qspinlock_paravirt.h
index df19ae4debd0..489a87884337 100644
--- a/kernel/locking/qspinlock_paravirt.h
+++ b/kernel/locking/qspinlock_paravirt.h
@@ -287,20 +287,21 @@ __visible void __pv_queued_spin_unlock(struct qspinlock *lock)
 {
 	struct __qspinlock *l = (void *)lock;
 	struct pv_node *node;
-	u8 lockval = cmpxchg(&l->locked, _Q_LOCKED_VAL, 0);
+	u8 locked;
 
 	/*
 	 * We must not unlock if SLOW, because in that case we must first
 	 * unhash. Otherwise it would be possible to have multiple @lock
 	 * entries, which would be BAD.
 	 */
-	if (likely(lockval == _Q_LOCKED_VAL))
+	locked = cmpxchg(&l->locked, _Q_LOCKED_VAL, 0);
+	if (likely(locked == _Q_LOCKED_VAL))
 		return;
 
-	if (unlikely(lockval != _Q_SLOW_VAL)) {
-		if (debug_locks_silent)
-			return;
-		WARN(1, "pvqspinlock: lock %p has corrupted value 0x%x!\n", lock, atomic_read(&lock->val));
+	if (unlikely(locked != _Q_SLOW_VAL)) {
+		WARN(!debug_locks_silent,
+		     "pvqspinlock: lock 0x%lx has corrupted value 0x%x!\n",
+		     (unsigned long)lock, atomic_read(&lock->val));
 		return;
 	}