Commit | Line | Data |
---|---|---|
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 | ||
17 | /* | |
18 | * This is the control structure for tasks blocked on a rt_mutex, | |
19 | * which is allocated on the kernel stack on of the blocked task. | |
20 | * | |
21 | * @list_entry: pi node to enqueue into the mutex waiters list | |
22 | * @pi_list_entry: pi node to enqueue into the mutex owner waiters list | |
23 | * @task: task reference to the blocked task | |
24 | */ | |
25 | struct rt_mutex_waiter { | |
26 | struct plist_node list_entry; | |
27 | struct plist_node pi_list_entry; | |
28 | struct task_struct *task; | |
29 | struct rt_mutex *lock; | |
30 | #ifdef CONFIG_DEBUG_RT_MUTEXES | |
31 | unsigned long ip; | |
32 | pid_t deadlock_task_pid; | |
33 | struct rt_mutex *deadlock_lock; | |
34 | #endif | |
35 | }; | |
36 | ||
37 | /* | |
38 | * Various helpers to access the waiters-plist: | |
39 | */ | |
40 | static inline int rt_mutex_has_waiters(struct rt_mutex *lock) | |
41 | { | |
42 | return !plist_head_empty(&lock->wait_list); | |
43 | } | |
44 | ||
45 | static inline struct rt_mutex_waiter * | |
46 | rt_mutex_top_waiter(struct rt_mutex *lock) | |
47 | { | |
48 | struct rt_mutex_waiter *w; | |
49 | ||
50 | w = plist_first_entry(&lock->wait_list, struct rt_mutex_waiter, | |
51 | list_entry); | |
52 | BUG_ON(w->lock != lock); | |
53 | ||
54 | return w; | |
55 | } | |
56 | ||
57 | static inline int task_has_pi_waiters(struct task_struct *p) | |
58 | { | |
59 | return !plist_head_empty(&p->pi_waiters); | |
60 | } | |
61 | ||
62 | static inline struct rt_mutex_waiter * | |
63 | task_top_pi_waiter(struct task_struct *p) | |
64 | { | |
65 | return plist_first_entry(&p->pi_waiters, struct rt_mutex_waiter, | |
66 | pi_list_entry); | |
67 | } | |
68 | ||
69 | /* | |
70 | * lock->owner state tracking: | |
71 | */ | |
72 | #define RT_MUTEX_OWNER_PENDING 1UL | |
73 | #define RT_MUTEX_HAS_WAITERS 2UL | |
74 | #define RT_MUTEX_OWNER_MASKALL 3UL | |
75 | ||
76 | static inline struct task_struct *rt_mutex_owner(struct rt_mutex *lock) | |
77 | { | |
78 | return (struct task_struct *) | |
79 | ((unsigned long)lock->owner & ~RT_MUTEX_OWNER_MASKALL); | |
80 | } | |
81 | ||
82 | static inline struct task_struct *rt_mutex_real_owner(struct rt_mutex *lock) | |
83 | { | |
84 | return (struct task_struct *) | |
85 | ((unsigned long)lock->owner & ~RT_MUTEX_HAS_WAITERS); | |
86 | } | |
87 | ||
88 | static inline unsigned long rt_mutex_owner_pending(struct rt_mutex *lock) | |
89 | { | |
90 | return (unsigned long)lock->owner & RT_MUTEX_OWNER_PENDING; | |
91 | } | |
92 | ||
93 | #endif |