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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 */
26struct 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)
33static inline void complete_acquire(struct completion *x) {}
34static inline void complete_release(struct completion *x) {}
35static inline void complete_release_commit(struct completion *x) {}
36
37#define COMPLETION_INITIALIZER(work) \
38 { 0, __WAIT_QUEUE_HEAD_INITIALIZER((work).wait) }
39
40#define COMPLETION_INITIALIZER_ONSTACK_MAP(work, map) \
41 (*({ init_completion_map(&(work), &(map)); &(work); }))
42
43#define COMPLETION_INITIALIZER_ONSTACK(work) \
44 (*({ init_completion(&work); &work; }))
45
46/**
47 * DECLARE_COMPLETION - declare and initialize a completion structure
48 * @work: identifier for the completion structure
49 *
50 * This macro declares and initializes a completion structure. Generally used
51 * for static declarations. You should use the _ONSTACK variant for automatic
52 * variables.
53 */
54#define DECLARE_COMPLETION(work) \
55 struct completion work = COMPLETION_INITIALIZER(work)
56
57/*
58 * Lockdep needs to run a non-constant initializer for on-stack
59 * completions - so we use the _ONSTACK() variant for those that
60 * are on the kernel stack:
61 */
62/**
63 * DECLARE_COMPLETION_ONSTACK - declare and initialize a completion structure
64 * @work: identifier for the completion structure
65 *
66 * This macro declares and initializes a completion structure on the kernel
67 * stack.
68 */
69#ifdef CONFIG_LOCKDEP
70# define DECLARE_COMPLETION_ONSTACK(work) \
71 struct completion work = COMPLETION_INITIALIZER_ONSTACK(work)
72# define DECLARE_COMPLETION_ONSTACK_MAP(work, map) \
73 struct completion work = COMPLETION_INITIALIZER_ONSTACK_MAP(work, map)
74#else
75# define DECLARE_COMPLETION_ONSTACK(work) DECLARE_COMPLETION(work)
76# define DECLARE_COMPLETION_ONSTACK_MAP(work, map) DECLARE_COMPLETION(work)
77#endif
78
79/**
80 * init_completion - Initialize a dynamically allocated completion
81 * @x: pointer to completion structure that is to be initialized
82 *
83 * This inline function will initialize a dynamically created completion
84 * structure.
85 */
86static inline void __init_completion(struct completion *x)
87{
88 x->done = 0;
89 init_waitqueue_head(&x->wait);
90}
91
92/**
93 * reinit_completion - reinitialize a completion structure
94 * @x: pointer to completion structure that is to be reinitialized
95 *
96 * This inline function should be used to reinitialize a completion structure so it can
97 * be reused. This is especially important after complete_all() is used.
98 */
99static inline void reinit_completion(struct completion *x)
100{
101 x->done = 0;
102}
103
104extern void wait_for_completion(struct completion *);
105extern void wait_for_completion_io(struct completion *);
106extern int wait_for_completion_interruptible(struct completion *x);
107extern int wait_for_completion_killable(struct completion *x);
108extern unsigned long wait_for_completion_timeout(struct completion *x,
109 unsigned long timeout);
110extern unsigned long wait_for_completion_io_timeout(struct completion *x,
111 unsigned long timeout);
112extern long wait_for_completion_interruptible_timeout(
113 struct completion *x, unsigned long timeout);
114extern long wait_for_completion_killable_timeout(
115 struct completion *x, unsigned long timeout);
116extern bool try_wait_for_completion(struct completion *x);
117extern bool completion_done(struct completion *x);
118
119extern void complete(struct completion *);
120extern void complete_all(struct completion *);
121
122#endif