1 files changed, 82 insertions, 59 deletions

diff --git a/include/linux/rtmutex.h b/include/linux/rtmutex.h
index de17134244f3..ede4c6bf6f22 100644
--- a/include/linux/rtmutex.h
+++ b/include/linux/rtmutex.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * RT Mutexes: blocking mutual exclusion locks with PI support
  *
@@ -12,28 +13,61 @@
 #ifndef __LINUX_RT_MUTEX_H
 #define __LINUX_RT_MUTEX_H
 
+#include <linux/compiler.h>
 #include <linux/linkage.h>
-#include <linux/plist.h>
-#include <linux/spinlock_types.h>
+#include <linux/rbtree_types.h>
+#include <linux/spinlock_types_raw.h>
 
-extern int max_lock_depth; /* for sysctl */
+extern int max_lock_depth;
+
+struct rt_mutex_base {
+	raw_spinlock_t		wait_lock;
+	struct rb_root_cached   waiters;
+	struct task_struct	*owner;
+};
+
+#define __RT_MUTEX_BASE_INITIALIZER(rtbasename)				\
+{									\
+	.wait_lock = __RAW_SPIN_LOCK_UNLOCKED(rtbasename.wait_lock),	\
+	.waiters = RB_ROOT_CACHED,					\
+	.owner = NULL							\
+}
+
+/**
+ * rt_mutex_base_is_locked - is the rtmutex locked
+ * @lock: the mutex to be queried
+ *
+ * Returns true if the mutex is locked, false if unlocked.
+ */
+static inline bool rt_mutex_base_is_locked(struct rt_mutex_base *lock)
+{
+	return READ_ONCE(lock->owner) != NULL;
+}
+
+#ifdef CONFIG_RT_MUTEXES
+#define RT_MUTEX_HAS_WAITERS	1UL
+
+static inline struct task_struct *rt_mutex_owner(struct rt_mutex_base *lock)
+{
+	unsigned long owner = (unsigned long) READ_ONCE(lock->owner);
+
+	return (struct task_struct *) (owner & ~RT_MUTEX_HAS_WAITERS);
+}
+#endif
+extern void rt_mutex_base_init(struct rt_mutex_base *rtb);
 
 /**
  * The rt_mutex structure
  *
  * @wait_lock:	spinlock to protect the structure
- * @wait_list:	pilist head to enqueue waiters in priority order
+ * @waiters:	rbtree root to enqueue waiters in priority order;
+ *              caches top-waiter (leftmost node).
  * @owner:	the mutex owner
  */
 struct rt_mutex {
-	raw_spinlock_t		wait_lock;
-	struct plist_head	wait_list;
-	struct task_struct	*owner;
-#ifdef CONFIG_DEBUG_RT_MUTEXES
-	int			save_state;
-	const char 		*name, *file;
-	int			line;
-	void			*magic;
+	struct rt_mutex_base	rtmutex;
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+	struct lockdep_map	dep_map;
 #endif
 };
 
@@ -41,69 +75,58 @@ struct rt_mutex_waiter;
 struct hrtimer_sleeper;
 
 #ifdef CONFIG_DEBUG_RT_MUTEXES
- extern int rt_mutex_debug_check_no_locks_freed(const void *from,
-						unsigned long len);
- extern void rt_mutex_debug_check_no_locks_held(struct task_struct *task);
+extern void rt_mutex_debug_task_free(struct task_struct *tsk);
 #else
- static inline int rt_mutex_debug_check_no_locks_freed(const void *from,
-						       unsigned long len)
- {
-	return 0;
- }
-# define rt_mutex_debug_check_no_locks_held(task)	do { } while (0)
+static inline void rt_mutex_debug_task_free(struct task_struct *tsk) { }
 #endif
 
-#ifdef CONFIG_DEBUG_RT_MUTEXES
-# define __DEBUG_RT_MUTEX_INITIALIZER(mutexname) \
-	, .name = #mutexname, .file = __FILE__, .line = __LINE__
-# define rt_mutex_init(mutex)			__rt_mutex_init(mutex, __func__)
- extern void rt_mutex_debug_task_free(struct task_struct *tsk);
+#define rt_mutex_init(mutex) \
+do { \
+	static struct lock_class_key __key; \
+	__rt_mutex_init(mutex, __func__, &__key); \
+} while (0)
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+#define __DEP_MAP_RT_MUTEX_INITIALIZER(mutexname)	\
+	.dep_map = {					\
+		.name = #mutexname,			\
+		.wait_type_inner = LD_WAIT_SLEEP,	\
+	}
 #else
-# define __DEBUG_RT_MUTEX_INITIALIZER(mutexname)
-# define rt_mutex_init(mutex)			__rt_mutex_init(mutex, NULL)
-# define rt_mutex_debug_task_free(t)			do { } while (0)
+#define __DEP_MAP_RT_MUTEX_INITIALIZER(mutexname)
 #endif
 
-#define __RT_MUTEX_INITIALIZER(mutexname) \
-	{ .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(mutexname.wait_lock) \
-	, .wait_list = PLIST_HEAD_INIT(mutexname.wait_list) \
-	, .owner = NULL \
-	__DEBUG_RT_MUTEX_INITIALIZER(mutexname)}
+#define __RT_MUTEX_INITIALIZER(mutexname)				\
+{									\
+	.rtmutex = __RT_MUTEX_BASE_INITIALIZER(mutexname.rtmutex),	\
+	__DEP_MAP_RT_MUTEX_INITIALIZER(mutexname)			\
+}
 
 #define DEFINE_RT_MUTEX(mutexname) \
 	struct rt_mutex mutexname = __RT_MUTEX_INITIALIZER(mutexname)
 
-/**
- * rt_mutex_is_locked - is the mutex locked
- * @lock: the mutex to be queried
- *
- * Returns 1 if the mutex is locked, 0 if unlocked.
- */
-static inline int rt_mutex_is_locked(struct rt_mutex *lock)
-{
-	return lock->owner != NULL;
-}
+extern void __rt_mutex_init(struct rt_mutex *lock, const char *name, struct lock_class_key *key);
 
-extern void __rt_mutex_init(struct rt_mutex *lock, const char *name);
-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);
+extern void _rt_mutex_lock_nest_lock(struct rt_mutex *lock, struct lockdep_map *nest_lock);
+#define rt_mutex_lock(lock) rt_mutex_lock_nested(lock, 0)
+#define rt_mutex_lock_nest_lock(lock, nest_lock)			\
+	do {								\
+		typecheck(struct lockdep_map *, &(nest_lock)->dep_map);	\
+		_rt_mutex_lock_nest_lock(lock, &(nest_lock)->dep_map);	\
+	} while (0)
 
+#else
 extern void rt_mutex_lock(struct rt_mutex *lock);
-extern int rt_mutex_lock_interruptible(struct rt_mutex *lock,
-						int detect_deadlock);
-extern int rt_mutex_timed_lock(struct rt_mutex *lock,
-					struct hrtimer_sleeper *timeout,
-					int detect_deadlock);
+#define rt_mutex_lock_nested(lock, subclass) rt_mutex_lock(lock)
+#define rt_mutex_lock_nest_lock(lock, nest_lock) rt_mutex_lock(lock)
+#endif
 
+extern int rt_mutex_lock_interruptible(struct rt_mutex *lock);
+extern int rt_mutex_lock_killable(struct rt_mutex *lock);
 extern int rt_mutex_trylock(struct rt_mutex *lock);
 
 extern void rt_mutex_unlock(struct rt_mutex *lock);
 
-#ifdef CONFIG_RT_MUTEXES
-# define INIT_RT_MUTEXES(tsk)						\
-	.pi_waiters	= PLIST_HEAD_INIT(tsk.pi_waiters),	\
-	INIT_RT_MUTEX_DEBUG(tsk)
-#else
-# define INIT_RT_MUTEXES(tsk)
-#endif
-
 #endif