1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | #ifndef __LINUX_COMPLETION_H |
3 | #define __LINUX_COMPLETION_H |
4 | |
5 | /* |
6 | * (C) Copyright 2001 Linus Torvalds |
7 | * |
8 | * Atomic wait-for-completion handler data structures. |
9 | * See kernel/sched/completion.c for details. |
10 | */ |
11 | |
12 | #include <linux/wait.h> |
13 | |
14 | /* |
15 | * struct completion - structure used to maintain state for a "completion" |
16 | * |
17 | * This is the opaque structure used to maintain the state for a "completion". |
18 | * Completions currently use a FIFO to queue threads that have to wait for |
19 | * the "completion" event. |
20 | * |
21 | * See also: complete(), wait_for_completion() (and friends _timeout, |
22 | * _interruptible, _interruptible_timeout, and _killable), init_completion(), |
23 | * reinit_completion(), and macros DECLARE_COMPLETION(), |
24 | * DECLARE_COMPLETION_ONSTACK(). |
25 | */ |
26 | struct completion { |
27 | unsigned int done; |
28 | wait_queue_head_t wait; |
29 | }; |
30 | |
31 | #define init_completion_map(x, m) __init_completion(x) |
32 | #define init_completion(x) __init_completion(x) |
33 | static inline void complete_acquire(struct completion *x) {} |
34 | static inline void complete_release(struct completion *x) {} |
35 | |
36 | #define COMPLETION_INITIALIZER(work) \ |
37 | { 0, __WAIT_QUEUE_HEAD_INITIALIZER((work).wait) } |
38 | |
39 | #define COMPLETION_INITIALIZER_ONSTACK_MAP(work, map) \ |
40 | (*({ init_completion_map(&(work), &(map)); &(work); })) |
41 | |
42 | #define COMPLETION_INITIALIZER_ONSTACK(work) \ |
43 | (*({ init_completion(&work); &work; })) |
44 | |
45 | /** |
46 | * DECLARE_COMPLETION - declare and initialize a completion structure |
47 | * @work: identifier for the completion structure |
48 | * |
49 | * This macro declares and initializes a completion structure. Generally used |
50 | * for static declarations. You should use the _ONSTACK variant for automatic |
51 | * variables. |
52 | */ |
53 | #define DECLARE_COMPLETION(work) \ |
54 | struct completion work = COMPLETION_INITIALIZER(work) |
55 | |
56 | /* |
57 | * Lockdep needs to run a non-constant initializer for on-stack |
58 | * completions - so we use the _ONSTACK() variant for those that |
59 | * are on the kernel stack: |
60 | */ |
61 | /** |
62 | * DECLARE_COMPLETION_ONSTACK - declare and initialize a completion structure |
63 | * @work: identifier for the completion structure |
64 | * |
65 | * This macro declares and initializes a completion structure on the kernel |
66 | * stack. |
67 | */ |
68 | #ifdef CONFIG_LOCKDEP |
69 | # define DECLARE_COMPLETION_ONSTACK(work) \ |
70 | struct completion work = COMPLETION_INITIALIZER_ONSTACK(work) |
71 | # define DECLARE_COMPLETION_ONSTACK_MAP(work, map) \ |
72 | struct completion work = COMPLETION_INITIALIZER_ONSTACK_MAP(work, map) |
73 | #else |
74 | # define DECLARE_COMPLETION_ONSTACK(work) DECLARE_COMPLETION(work) |
75 | # define DECLARE_COMPLETION_ONSTACK_MAP(work, map) DECLARE_COMPLETION(work) |
76 | #endif |
77 | |
78 | /** |
79 | * init_completion - Initialize a dynamically allocated completion |
80 | * @x: pointer to completion structure that is to be initialized |
81 | * |
82 | * This inline function will initialize a dynamically created completion |
83 | * structure. |
84 | */ |
85 | static inline void __init_completion(struct completion *x) |
86 | { |
87 | x->done = 0; |
88 | init_waitqueue_head(&x->wait); |
89 | } |
90 | |
91 | /** |
92 | * reinit_completion - reinitialize a completion structure |
93 | * @x: pointer to completion structure that is to be reinitialized |
94 | * |
95 | * This inline function should be used to reinitialize a completion structure so it can |
96 | * be reused. This is especially important after complete_all() is used. |
97 | */ |
98 | static inline void reinit_completion(struct completion *x) |
99 | { |
100 | x->done = 0; |
101 | } |
102 | |
103 | extern void wait_for_completion(struct completion *); |
104 | extern void wait_for_completion_io(struct completion *); |
105 | extern int wait_for_completion_interruptible(struct completion *x); |
106 | extern int wait_for_completion_killable(struct completion *x); |
107 | extern unsigned long wait_for_completion_timeout(struct completion *x, |
108 | unsigned long timeout); |
109 | extern unsigned long wait_for_completion_io_timeout(struct completion *x, |
110 | unsigned long timeout); |
111 | extern long wait_for_completion_interruptible_timeout( |
112 | struct completion *x, unsigned long timeout); |
113 | extern long wait_for_completion_killable_timeout( |
114 | struct completion *x, unsigned long timeout); |
115 | extern bool try_wait_for_completion(struct completion *x); |
116 | extern bool completion_done(struct completion *x); |
117 | |
118 | extern void complete(struct completion *); |
119 | extern void complete_all(struct completion *); |
120 | |
121 | #endif |
122 | |