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23f78d4a IM |
1 | /* |
2 | * RT Mutexes: blocking mutual exclusion locks with PI support | |
3 | * | |
4 | * started by Ingo Molnar and Thomas Gleixner: | |
5 | * | |
6 | * Copyright (C) 2004-2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com> | |
7 | * Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com> | |
8 | * | |
9 | * This file contains the private data structure and API definitions. | |
10 | */ | |
11 | ||
12 | #ifndef __KERNEL_RTMUTEX_COMMON_H | |
13 | #define __KERNEL_RTMUTEX_COMMON_H | |
14 | ||
15 | #include <linux/rtmutex.h> | |
16 | ||
61a87122 TG |
17 | /* |
18 | * The rtmutex in kernel tester is independent of rtmutex debugging. We | |
19 | * call schedule_rt_mutex_test() instead of schedule() for the tasks which | |
20 | * belong to the tester. That way we can delay the wakeup path of those | |
21 | * threads to provoke lock stealing and testing of complex boosting scenarios. | |
22 | */ | |
23 | #ifdef CONFIG_RT_MUTEX_TESTER | |
24 | ||
25 | extern void schedule_rt_mutex_test(struct rt_mutex *lock); | |
26 | ||
27 | #define schedule_rt_mutex(_lock) \ | |
28 | do { \ | |
29 | if (!(current->flags & PF_MUTEX_TESTER)) \ | |
30 | schedule(); \ | |
31 | else \ | |
32 | schedule_rt_mutex_test(_lock); \ | |
33 | } while (0) | |
34 | ||
35 | #else | |
36 | # define schedule_rt_mutex(_lock) schedule() | |
37 | #endif | |
38 | ||
23f78d4a IM |
39 | /* |
40 | * This is the control structure for tasks blocked on a rt_mutex, | |
41 | * which is allocated on the kernel stack on of the blocked task. | |
42 | * | |
fb00aca4 PZ |
43 | * @tree_entry: pi node to enqueue into the mutex waiters tree |
44 | * @pi_tree_entry: pi node to enqueue into the mutex owner waiters tree | |
23f78d4a IM |
45 | * @task: task reference to the blocked task |
46 | */ | |
47 | struct rt_mutex_waiter { | |
fb00aca4 PZ |
48 | struct rb_node tree_entry; |
49 | struct rb_node pi_tree_entry; | |
23f78d4a IM |
50 | struct task_struct *task; |
51 | struct rt_mutex *lock; | |
52 | #ifdef CONFIG_DEBUG_RT_MUTEXES | |
53 | unsigned long ip; | |
48d13e48 | 54 | struct pid *deadlock_task_pid; |
23f78d4a IM |
55 | struct rt_mutex *deadlock_lock; |
56 | #endif | |
2d3d891d | 57 | int prio; |
23f78d4a IM |
58 | }; |
59 | ||
60 | /* | |
fb00aca4 | 61 | * Various helpers to access the waiters-tree: |
23f78d4a IM |
62 | */ |
63 | static inline int rt_mutex_has_waiters(struct rt_mutex *lock) | |
64 | { | |
fb00aca4 | 65 | return !RB_EMPTY_ROOT(&lock->waiters); |
23f78d4a IM |
66 | } |
67 | ||
68 | static inline struct rt_mutex_waiter * | |
69 | rt_mutex_top_waiter(struct rt_mutex *lock) | |
70 | { | |
71 | struct rt_mutex_waiter *w; | |
72 | ||
fb00aca4 PZ |
73 | w = rb_entry(lock->waiters_leftmost, struct rt_mutex_waiter, |
74 | tree_entry); | |
23f78d4a IM |
75 | BUG_ON(w->lock != lock); |
76 | ||
77 | return w; | |
78 | } | |
79 | ||
80 | static inline int task_has_pi_waiters(struct task_struct *p) | |
81 | { | |
fb00aca4 | 82 | return !RB_EMPTY_ROOT(&p->pi_waiters); |
23f78d4a IM |
83 | } |
84 | ||
85 | static inline struct rt_mutex_waiter * | |
86 | task_top_pi_waiter(struct task_struct *p) | |
87 | { | |
fb00aca4 PZ |
88 | return rb_entry(p->pi_waiters_leftmost, struct rt_mutex_waiter, |
89 | pi_tree_entry); | |
23f78d4a IM |
90 | } |
91 | ||
92 | /* | |
93 | * lock->owner state tracking: | |
94 | */ | |
8161239a LJ |
95 | #define RT_MUTEX_HAS_WAITERS 1UL |
96 | #define RT_MUTEX_OWNER_MASKALL 1UL | |
23f78d4a IM |
97 | |
98 | static inline struct task_struct *rt_mutex_owner(struct rt_mutex *lock) | |
99 | { | |
100 | return (struct task_struct *) | |
101 | ((unsigned long)lock->owner & ~RT_MUTEX_OWNER_MASKALL); | |
102 | } | |
103 | ||
c87e2837 IM |
104 | /* |
105 | * PI-futex support (proxy locking functions, etc.): | |
106 | */ | |
107 | extern struct task_struct *rt_mutex_next_owner(struct rt_mutex *lock); | |
108 | extern void rt_mutex_init_proxy_locked(struct rt_mutex *lock, | |
109 | struct task_struct *proxy_owner); | |
110 | extern void rt_mutex_proxy_unlock(struct rt_mutex *lock, | |
111 | struct task_struct *proxy_owner); | |
8dac456a DH |
112 | extern int rt_mutex_start_proxy_lock(struct rt_mutex *lock, |
113 | struct rt_mutex_waiter *waiter, | |
114 | struct task_struct *task, | |
115 | int detect_deadlock); | |
116 | extern int rt_mutex_finish_proxy_lock(struct rt_mutex *lock, | |
117 | struct hrtimer_sleeper *to, | |
118 | struct rt_mutex_waiter *waiter, | |
119 | int detect_deadlock); | |
36cf3b5c TG |
120 | |
121 | #ifdef CONFIG_DEBUG_RT_MUTEXES | |
122 | # include "rtmutex-debug.h" | |
123 | #else | |
124 | # include "rtmutex.h" | |
125 | #endif | |
126 | ||
23f78d4a | 127 | #endif |