locking, rwsem: Annotate inner lock as raw

There is no reason to allow the lock protecting rwsems (the
ownerless variant) to be preemptible on -rt. Convert it to raw.

In mainline this change documents the low level nature of
the lock - otherwise there's no functional difference. Lockdep
and Sparse checking will work as usual.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/lib/rwsem.c b/lib/rwsem.c
index aa7c305..410aa11 100644
--- a/lib/rwsem.c
+++ b/lib/rwsem.c
@@ -22,7 +22,7 @@
 	lockdep_init_map(&sem->dep_map, name, key, 0);
 #endif
 	sem->count = RWSEM_UNLOCKED_VALUE;
-	spin_lock_init(&sem->wait_lock);
+	raw_spin_lock_init(&sem->wait_lock);
 	INIT_LIST_HEAD(&sem->wait_list);
 }
 
@@ -180,7 +180,7 @@
 	set_task_state(tsk, TASK_UNINTERRUPTIBLE);
 
 	/* set up my own style of waitqueue */
-	spin_lock_irq(&sem->wait_lock);
+	raw_spin_lock_irq(&sem->wait_lock);
 	waiter.task = tsk;
 	waiter.flags = flags;
 	get_task_struct(tsk);
@@ -204,7 +204,7 @@
 		 adjustment == -RWSEM_ACTIVE_WRITE_BIAS)
 		sem = __rwsem_do_wake(sem, RWSEM_WAKE_READ_OWNED);
 
-	spin_unlock_irq(&sem->wait_lock);
+	raw_spin_unlock_irq(&sem->wait_lock);
 
 	/* wait to be given the lock */
 	for (;;) {
@@ -245,13 +245,13 @@
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&sem->wait_lock, flags);
+	raw_spin_lock_irqsave(&sem->wait_lock, flags);
 
 	/* do nothing if list empty */
 	if (!list_empty(&sem->wait_list))
 		sem = __rwsem_do_wake(sem, RWSEM_WAKE_ANY);
 
-	spin_unlock_irqrestore(&sem->wait_lock, flags);
+	raw_spin_unlock_irqrestore(&sem->wait_lock, flags);
 
 	return sem;
 }
@@ -265,13 +265,13 @@
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&sem->wait_lock, flags);
+	raw_spin_lock_irqsave(&sem->wait_lock, flags);
 
 	/* do nothing if list empty */
 	if (!list_empty(&sem->wait_list))
 		sem = __rwsem_do_wake(sem, RWSEM_WAKE_READ_OWNED);
 
-	spin_unlock_irqrestore(&sem->wait_lock, flags);
+	raw_spin_unlock_irqrestore(&sem->wait_lock, flags);
 
 	return sem;
 }