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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
23f78d4a IM |
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 <mingo@redhat.com> | |
8 | * Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com> | |
9 | * | |
10 | * This file contains the private data structure and API definitions. | |
11 | */ | |
12 | ||
13 | #ifndef __KERNEL_RTMUTEX_COMMON_H | |
14 | #define __KERNEL_RTMUTEX_COMMON_H | |
15 | ||
16 | #include <linux/rtmutex.h> | |
84f001e1 | 17 | #include <linux/sched/wake_q.h> |
23f78d4a IM |
18 | |
19 | /* | |
20 | * This is the control structure for tasks blocked on a rt_mutex, | |
21 | * which is allocated on the kernel stack on of the blocked task. | |
22 | * | |
fb00aca4 PZ |
23 | * @tree_entry: pi node to enqueue into the mutex waiters tree |
24 | * @pi_tree_entry: pi node to enqueue into the mutex owner waiters tree | |
23f78d4a IM |
25 | * @task: task reference to the blocked task |
26 | */ | |
27 | struct rt_mutex_waiter { | |
fb00aca4 PZ |
28 | struct rb_node tree_entry; |
29 | struct rb_node pi_tree_entry; | |
23f78d4a IM |
30 | struct task_struct *task; |
31 | struct rt_mutex *lock; | |
32 | #ifdef CONFIG_DEBUG_RT_MUTEXES | |
33 | unsigned long ip; | |
48d13e48 | 34 | struct pid *deadlock_task_pid; |
23f78d4a IM |
35 | struct rt_mutex *deadlock_lock; |
36 | #endif | |
2d3d891d | 37 | int prio; |
e0aad5b4 | 38 | u64 deadline; |
23f78d4a IM |
39 | }; |
40 | ||
41 | /* | |
fb00aca4 | 42 | * Various helpers to access the waiters-tree: |
23f78d4a | 43 | */ |
bc2eecd7 NP |
44 | |
45 | #ifdef CONFIG_RT_MUTEXES | |
46 | ||
23f78d4a IM |
47 | static inline int rt_mutex_has_waiters(struct rt_mutex *lock) |
48 | { | |
a23ba907 | 49 | return !RB_EMPTY_ROOT(&lock->waiters.rb_root); |
23f78d4a IM |
50 | } |
51 | ||
52 | static inline struct rt_mutex_waiter * | |
53 | rt_mutex_top_waiter(struct rt_mutex *lock) | |
54 | { | |
c28d62cf PZ |
55 | struct rb_node *leftmost = rb_first_cached(&lock->waiters); |
56 | struct rt_mutex_waiter *w = NULL; | |
23f78d4a | 57 | |
c28d62cf PZ |
58 | if (leftmost) { |
59 | w = rb_entry(leftmost, struct rt_mutex_waiter, tree_entry); | |
60 | BUG_ON(w->lock != lock); | |
61 | } | |
23f78d4a IM |
62 | return w; |
63 | } | |
64 | ||
65 | static inline int task_has_pi_waiters(struct task_struct *p) | |
66 | { | |
a23ba907 | 67 | return !RB_EMPTY_ROOT(&p->pi_waiters.rb_root); |
23f78d4a IM |
68 | } |
69 | ||
70 | static inline struct rt_mutex_waiter * | |
71 | task_top_pi_waiter(struct task_struct *p) | |
72 | { | |
a23ba907 DB |
73 | return rb_entry(p->pi_waiters.rb_leftmost, |
74 | struct rt_mutex_waiter, pi_tree_entry); | |
23f78d4a IM |
75 | } |
76 | ||
bc2eecd7 NP |
77 | #else |
78 | ||
79 | static inline int rt_mutex_has_waiters(struct rt_mutex *lock) | |
80 | { | |
81 | return false; | |
82 | } | |
83 | ||
84 | static inline struct rt_mutex_waiter * | |
85 | rt_mutex_top_waiter(struct rt_mutex *lock) | |
86 | { | |
87 | return NULL; | |
88 | } | |
89 | ||
90 | static inline int task_has_pi_waiters(struct task_struct *p) | |
91 | { | |
92 | return false; | |
93 | } | |
94 | ||
95 | static inline struct rt_mutex_waiter * | |
96 | task_top_pi_waiter(struct task_struct *p) | |
97 | { | |
98 | return NULL; | |
99 | } | |
100 | ||
101 | #endif | |
102 | ||
23f78d4a IM |
103 | /* |
104 | * lock->owner state tracking: | |
105 | */ | |
8161239a | 106 | #define RT_MUTEX_HAS_WAITERS 1UL |
23f78d4a IM |
107 | |
108 | static inline struct task_struct *rt_mutex_owner(struct rt_mutex *lock) | |
109 | { | |
1be5d4fa TG |
110 | unsigned long owner = (unsigned long) READ_ONCE(lock->owner); |
111 | ||
b5016e82 | 112 | return (struct task_struct *) (owner & ~RT_MUTEX_HAS_WAITERS); |
23f78d4a IM |
113 | } |
114 | ||
8930ed80 TG |
115 | /* |
116 | * Constants for rt mutex functions which have a selectable deadlock | |
117 | * detection. | |
118 | * | |
119 | * RT_MUTEX_MIN_CHAINWALK: Stops the lock chain walk when there are | |
120 | * no further PI adjustments to be made. | |
121 | * | |
122 | * RT_MUTEX_FULL_CHAINWALK: Invoke deadlock detection with a full | |
123 | * walk of the lock chain. | |
124 | */ | |
125 | enum rtmutex_chainwalk { | |
126 | RT_MUTEX_MIN_CHAINWALK, | |
127 | RT_MUTEX_FULL_CHAINWALK, | |
128 | }; | |
129 | ||
c87e2837 IM |
130 | /* |
131 | * PI-futex support (proxy locking functions, etc.): | |
132 | */ | |
133 | extern struct task_struct *rt_mutex_next_owner(struct rt_mutex *lock); | |
134 | extern void rt_mutex_init_proxy_locked(struct rt_mutex *lock, | |
135 | struct task_struct *proxy_owner); | |
136 | extern void rt_mutex_proxy_unlock(struct rt_mutex *lock, | |
137 | struct task_struct *proxy_owner); | |
50809358 | 138 | extern void rt_mutex_init_waiter(struct rt_mutex_waiter *waiter); |
56222b21 PZ |
139 | extern int __rt_mutex_start_proxy_lock(struct rt_mutex *lock, |
140 | struct rt_mutex_waiter *waiter, | |
141 | struct task_struct *task); | |
8dac456a DH |
142 | extern int rt_mutex_start_proxy_lock(struct rt_mutex *lock, |
143 | struct rt_mutex_waiter *waiter, | |
c051b21f | 144 | struct task_struct *task); |
38d589f2 PZ |
145 | extern int rt_mutex_wait_proxy_lock(struct rt_mutex *lock, |
146 | struct hrtimer_sleeper *to, | |
147 | struct rt_mutex_waiter *waiter); | |
148 | extern bool rt_mutex_cleanup_proxy_lock(struct rt_mutex *lock, | |
149 | struct rt_mutex_waiter *waiter); | |
5293c2ef | 150 | |
5293c2ef | 151 | extern int rt_mutex_futex_trylock(struct rt_mutex *l); |
c1e2f0ea | 152 | extern int __rt_mutex_futex_trylock(struct rt_mutex *l); |
5293c2ef PZ |
153 | |
154 | extern void rt_mutex_futex_unlock(struct rt_mutex *lock); | |
155 | extern bool __rt_mutex_futex_unlock(struct rt_mutex *lock, | |
156 | struct wake_q_head *wqh); | |
157 | ||
aa2bfe55 | 158 | extern void rt_mutex_postunlock(struct wake_q_head *wake_q); |
36cf3b5c TG |
159 | |
160 | #ifdef CONFIG_DEBUG_RT_MUTEXES | |
161 | # include "rtmutex-debug.h" | |
162 | #else | |
163 | # include "rtmutex.h" | |
164 | #endif | |
165 | ||
23f78d4a | 166 | #endif |