1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * RT Mutexes: blocking mutual exclusion locks with PI support 4 * 5 * started by Ingo Molnar and Thomas Gleixner: 6 * 7 * Copyright (C) 2004-2006 Red Hat, Inc., Ingo Molnar <[email protected]> 8 * Copyright (C) 2006, Timesys Corp., Thomas Gleixner <[email protected]> 9 * 10 * This file contains the public data structure and API definitions. 11 */ 12 13 #ifndef __LINUX_RT_MUTEX_H 14 #define __LINUX_RT_MUTEX_H 15 16 #include <linux/linkage.h> 17 #include <linux/rbtree.h> 18 #include <linux/spinlock_types.h> 19 20 extern int max_lock_depth; /* for sysctl */ 21 22 struct rt_mutex_base { 23 raw_spinlock_t wait_lock; 24 struct rb_root_cached waiters; 25 struct task_struct *owner; 26 }; 27 28 #define __RT_MUTEX_BASE_INITIALIZER(rtbasename) \ 29 { \ 30 .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(rtbasename.wait_lock), \ 31 .waiters = RB_ROOT_CACHED, \ 32 .owner = NULL \ 33 } 34 35 extern void rt_mutex_base_init(struct rt_mutex_base *rtb); 36 37 /** 38 * The rt_mutex structure 39 * 40 * @wait_lock: spinlock to protect the structure 41 * @waiters: rbtree root to enqueue waiters in priority order; 42 * caches top-waiter (leftmost node). 43 * @owner: the mutex owner 44 */ 45 struct rt_mutex { 46 struct rt_mutex_base rtmutex; 47 #ifdef CONFIG_DEBUG_LOCK_ALLOC 48 struct lockdep_map dep_map; 49 #endif 50 }; 51 52 struct rt_mutex_waiter; 53 struct hrtimer_sleeper; 54 55 #ifdef CONFIG_DEBUG_RT_MUTEXES 56 extern void rt_mutex_debug_task_free(struct task_struct *tsk); 57 #else 58 static inline void rt_mutex_debug_task_free(struct task_struct *tsk) { } 59 #endif 60 61 #define rt_mutex_init(mutex) \ 62 do { \ 63 static struct lock_class_key __key; \ 64 __rt_mutex_init(mutex, __func__, &__key); \ 65 } while (0) 66 67 #ifdef CONFIG_DEBUG_LOCK_ALLOC 68 #define __DEP_MAP_RT_MUTEX_INITIALIZER(mutexname) \ 69 .dep_map = { \ 70 .name = #mutexname, \ 71 .wait_type_inner = LD_WAIT_SLEEP, \ 72 } 73 #else 74 #define __DEP_MAP_RT_MUTEX_INITIALIZER(mutexname) 75 #endif 76 77 #define __RT_MUTEX_INITIALIZER(mutexname) \ 78 { \ 79 .rtmutex = __RT_MUTEX_BASE_INITIALIZER(mutexname.rtmutex), \ 80 __DEP_MAP_RT_MUTEX_INITIALIZER(mutexname) \ 81 } 82 83 #define DEFINE_RT_MUTEX(mutexname) \ 84 struct rt_mutex mutexname = __RT_MUTEX_INITIALIZER(mutexname) 85 86 extern void __rt_mutex_init(struct rt_mutex *lock, const char *name, struct lock_class_key *key); 87 88 #ifdef CONFIG_DEBUG_LOCK_ALLOC 89 extern void rt_mutex_lock_nested(struct rt_mutex *lock, unsigned int subclass); 90 #define rt_mutex_lock(lock) rt_mutex_lock_nested(lock, 0) 91 #else 92 extern void rt_mutex_lock(struct rt_mutex *lock); 93 #define rt_mutex_lock_nested(lock, subclass) rt_mutex_lock(lock) 94 #endif 95 96 extern int rt_mutex_lock_interruptible(struct rt_mutex *lock); 97 extern int rt_mutex_trylock(struct rt_mutex *lock); 98 99 extern void rt_mutex_unlock(struct rt_mutex *lock); 100 101 #endif 102