From 4d9d951e6b5df85ccfca2c5bd8b4f5c71d256b65 Mon Sep 17 00:00:00 2001
From: Jason Low <jason.low2@hp.com>
Date: Mon, 14 Jul 2014 10:27:50 -0700
Subject: 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 <jason.low2@hp.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Scott Norton <scott.norton@hp.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Waiman Long <waiman.long@hp.com>
Cc: Davidlohr Bueso <davidlohr@hp.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Aswin Chandramouleeswaran <aswin@hp.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <jbacik@fusionio.com>
Link: http://lkml.kernel.org/r/1405358872-3732-4-git-send-email-jason.low2@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 include/linux/osq_lock.h | 8 ++++++++
 include/linux/rwsem.h    | 2 +-
 2 files changed, 9 insertions(+), 1 deletion(-)

(limited to 'include')

diff --git a/include/linux/osq_lock.h b/include/linux/osq_lock.h
index b001682bf7c..90230d5811c 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 9fdcdd03507..25cd9aa2f3d 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)			\
-- 
cgit v1.2.3-18-g5258