commit 8292c9e15c3b069459794a04f5e2cf0d5665ddc4
author Thomas Gleixner <tglx@linutronix.de> Wed Feb 24 09:50:22 2010 +0100
committer Ingo Molnar <mingo@elte.hu> Tue Sep 13 11:11:57 2011 +0200
tree 6dd98e626c2dc5fc38a7838295039226b301ee57
parent ee30a7b2fc072f139dac44826860d2c1f422137c

locking, semaphores: Annotate inner lock as raw

There is no reason to have the spin_lock protecting the semaphore
preemptible on -rt. Annotate it as a raw_spinlock.

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.

( On rt this also solves lockdep complaining about the
  rt_mutex.wait_lock being not initialized. )

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

kernel/semaphore.c

diff --git a/kernel/semaphore.c b/kernel/semaphore.c
index 94a62c0..d831841 100644
--- a/kernel/semaphore.c
+++ b/kernel/semaphore.c
@@ -54,12 +54,12 @@
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&sem->lock, flags);
+	raw_spin_lock_irqsave(&sem->lock, flags);
 	if (likely(sem->count > 0))
 		sem->count--;
 	else
 		__down(sem);
-	spin_unlock_irqrestore(&sem->lock, flags);
+	raw_spin_unlock_irqrestore(&sem->lock, flags);
 }
 EXPORT_SYMBOL(down);
 
@@ -77,12 +77,12 @@
 	unsigned long flags;
 	int result = 0;
 
-	spin_lock_irqsave(&sem->lock, flags);
+	raw_spin_lock_irqsave(&sem->lock, flags);
 	if (likely(sem->count > 0))
 		sem->count--;
 	else
 		result = __down_interruptible(sem);
-	spin_unlock_irqrestore(&sem->lock, flags);
+	raw_spin_unlock_irqrestore(&sem->lock, flags);
 
 	return result;
 }
@@ -103,12 +103,12 @@
 	unsigned long flags;
 	int result = 0;
 
-	spin_lock_irqsave(&sem->lock, flags);
+	raw_spin_lock_irqsave(&sem->lock, flags);
 	if (likely(sem->count > 0))
 		sem->count--;
 	else
 		result = __down_killable(sem);
-	spin_unlock_irqrestore(&sem->lock, flags);
+	raw_spin_unlock_irqrestore(&sem->lock, flags);
 
 	return result;
 }
@@ -132,11 +132,11 @@
 	unsigned long flags;
 	int count;
 
-	spin_lock_irqsave(&sem->lock, flags);
+	raw_spin_lock_irqsave(&sem->lock, flags);
 	count = sem->count - 1;
 	if (likely(count >= 0))
 		sem->count = count;
-	spin_unlock_irqrestore(&sem->lock, flags);
+	raw_spin_unlock_irqrestore(&sem->lock, flags);
 
 	return (count < 0);
 }
@@ -157,12 +157,12 @@
 	unsigned long flags;
 	int result = 0;
 
-	spin_lock_irqsave(&sem->lock, flags);
+	raw_spin_lock_irqsave(&sem->lock, flags);
 	if (likely(sem->count > 0))
 		sem->count--;
 	else
 		result = __down_timeout(sem, jiffies);
-	spin_unlock_irqrestore(&sem->lock, flags);
+	raw_spin_unlock_irqrestore(&sem->lock, flags);
 
 	return result;
 }
@@ -179,12 +179,12 @@
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&sem->lock, flags);
+	raw_spin_lock_irqsave(&sem->lock, flags);
 	if (likely(list_empty(&sem->wait_list)))
 		sem->count++;
 	else
 		__up(sem);
-	spin_unlock_irqrestore(&sem->lock, flags);
+	raw_spin_unlock_irqrestore(&sem->lock, flags);
 }
 EXPORT_SYMBOL(up);
 
@@ -217,9 +217,9 @@
 		if (timeout <= 0)
 			goto timed_out;
 		__set_task_state(task, state);
-		spin_unlock_irq(&sem->lock);
+		raw_spin_unlock_irq(&sem->lock);
 		timeout = schedule_timeout(timeout);
-		spin_lock_irq(&sem->lock);
+		raw_spin_lock_irq(&sem->lock);
 		if (waiter.up)
 			return 0;
 	}