locking/rtmutex: Allow specifying a subclass for nested locking

[ Upstream commit 62cedf3 ] Needed for annotating rt_mutex locks. Tested-by: John Sperbeck <[email protected]> Signed-off-by: Peter Rosin <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Davidlohr Bueso <[email protected]> Cc: Deepa Dinamani <[email protected]> Cc: Greg Kroah-Hartman <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Chang <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Philippe Ombredanne <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Will Deacon <[email protected]> Cc: Wolfram Sang <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> Signed-off-by: Sasha Levin <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
beagleboard · Sep 5, 2018 · b3da5df · b3da5df
1 parent 354e35b
commit b3da5df
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Showing 2 changed files with 32 additions and 4 deletions.
diff --git a/include/linux/rtmutex.h b/include/linux/rtmutex.h
@@ -106,7 +106,14 @@ static inline int rt_mutex_is_locked(struct rt_mutex *lock)
 extern void __rt_mutex_init(struct rt_mutex *lock, const char *name, struct lock_class_key *key);
 extern void rt_mutex_destroy(struct rt_mutex *lock);
 
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+extern void rt_mutex_lock_nested(struct rt_mutex *lock, unsigned int subclass);
+#define rt_mutex_lock(lock) rt_mutex_lock_nested(lock, 0)
+#else
 extern void rt_mutex_lock(struct rt_mutex *lock);
+#define rt_mutex_lock_nested(lock, subclass) rt_mutex_lock(lock)
+#endif
+
 extern int rt_mutex_lock_interruptible(struct rt_mutex *lock);
 extern int rt_mutex_timed_lock(struct rt_mutex *lock,
 			       struct hrtimer_sleeper *timeout);

diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c
@@ -1466,19 +1466,40 @@ rt_mutex_fastunlock(struct rt_mutex *lock,
 		rt_mutex_postunlock(&wake_q);
 }
 
+static inline void __rt_mutex_lock(struct rt_mutex *lock, unsigned int subclass)
+{
+	might_sleep();
+
+	mutex_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
+	rt_mutex_fastlock(lock, TASK_UNINTERRUPTIBLE, rt_mutex_slowlock);
+}
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+/**
+ * rt_mutex_lock_nested - lock a rt_mutex
+ *
+ * @lock: the rt_mutex to be locked
+ * @subclass: the lockdep subclass
+ */
+void __sched rt_mutex_lock_nested(struct rt_mutex *lock, unsigned int subclass)
+{
+	__rt_mutex_lock(lock, subclass);
+}
+EXPORT_SYMBOL_GPL(rt_mutex_lock_nested);
+#endif
+
+#ifndef CONFIG_DEBUG_LOCK_ALLOC
 /**
  * rt_mutex_lock - lock a rt_mutex
  *
  * @lock: the rt_mutex to be locked
  */
 void __sched rt_mutex_lock(struct rt_mutex *lock)
 {
-	might_sleep();
-
-	mutex_acquire(&lock->dep_map, 0, 0, _RET_IP_);
-	rt_mutex_fastlock(lock, TASK_UNINTERRUPTIBLE, rt_mutex_slowlock);
+	__rt_mutex_lock(lock, 0);
 }
 EXPORT_SYMBOL_GPL(rt_mutex_lock);
+#endif
 
 /**
  * rt_mutex_lock_interruptible - lock a rt_mutex interruptible