locking/spinlocks/mcs: Introduce and use init macro and function for osq locks

Currently, we initialize the osq lock by directly setting the lock's values. It
would be preferable if we use an init macro to do the initialization like we do
with other locks.

This patch introduces and uses a macro and function for initializing the osq lock.

Signed-off-by: Jason Low <[email protected]>
Signed-off-by: Peter Zijlstra <[email protected]>
Cc: Scott Norton <[email protected]>
Cc: "Paul E. McKenney" <[email protected]>
Cc: Dave Chinner <[email protected]>
Cc: Waiman Long <[email protected]>
Cc: Davidlohr Bueso <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Tim Chen <[email protected]>
Cc: Konrad Rzeszutek Wilk <[email protected]>
Cc: Aswin Chandramouleeswaran <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Chris Mason <[email protected]>
Cc: Josef Bacik <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

4 files changed, 11 insertions, 3 deletions

diff --git a/include/linux/osq_lock.h b/include/linux/osq_lock.h
index b001682bf7cb..90230d5811c5 100644
--- a/include/linux/osq_lock.h
+++ b/include/linux/osq_lock.h
@@ -16,4 +16,12 @@ struct optimistic_spin_queue {
 	atomic_t tail;
 };
 
+/* Init macro and function. */
+#define OSQ_LOCK_UNLOCKED { ATOMIC_INIT(OSQ_UNLOCKED_VAL) }
+
+static inline void osq_lock_init(struct optimistic_spin_queue *lock)
+{
+	atomic_set(&lock->tail, OSQ_UNLOCKED_VAL);
+}
+
 #endif
diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h
index 9fdcdd03507d..25cd9aa2f3d7 100644
--- a/include/linux/rwsem.h
+++ b/include/linux/rwsem.h
@@ -69,7 +69,7 @@ static inline int rwsem_is_locked(struct rw_semaphore *sem)
 	  __RAW_SPIN_LOCK_UNLOCKED(name.wait_lock),	\
 	  LIST_HEAD_INIT((name).wait_list),		\
 	  NULL, /* owner */				\
-	  { ATOMIC_INIT(OSQ_UNLOCKED_VAL) } /* osq */   \
+	  OSQ_LOCK_UNLOCKED /* osq */			\
 	  __RWSEM_DEP_MAP_INIT(name) }
 #else
 #define __RWSEM_INITIALIZER(name)			\
diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c
index d9b313906caa..acca2c1a3c5e 100644
--- a/kernel/locking/mutex.c
+++ b/kernel/locking/mutex.c
@@ -60,7 +60,7 @@ __mutex_init(struct mutex *lock, const char *name, struct lock_class_key *key)
 	INIT_LIST_HEAD(&lock->wait_list);
 	mutex_clear_owner(lock);
 #ifdef CONFIG_MUTEX_SPIN_ON_OWNER
-	atomic_set(&lock->osq.tail, OSQ_UNLOCKED_VAL);
+	osq_lock_init(&lock->osq);
 #endif
 
 	debug_mutex_init(lock, name, key);
diff --git a/kernel/locking/rwsem-xadd.c b/kernel/locking/rwsem-xadd.c
index b77a6230bbf6..7190592c2645 100644
--- a/kernel/locking/rwsem-xadd.c
+++ b/kernel/locking/rwsem-xadd.c
@@ -84,7 +84,7 @@ void __init_rwsem(struct rw_semaphore *sem, const char *name,
 	INIT_LIST_HEAD(&sem->wait_list);
 #ifdef CONFIG_SMP
 	sem->owner = NULL;
-	atomic_set(&sem->osq.tail, OSQ_UNLOCKED_VAL);
+	osq_lock_init(&sem->osq);
 #endif
 }