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) {}
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 */
85static 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 */
98static inline void reinit_completion(struct completion *x)
99{
100 x->done = 0;
101}
102
103extern void wait_for_completion(struct completion *);
104extern void wait_for_completion_io(struct completion *);
105extern int wait_for_completion_interruptible(struct completion *x);
106extern int wait_for_completion_killable(struct completion *x);
107extern unsigned long wait_for_completion_timeout(struct completion *x,
108 unsigned long timeout);
109extern unsigned long wait_for_completion_io_timeout(struct completion *x,
110 unsigned long timeout);
111extern long wait_for_completion_interruptible_timeout(
112 struct completion *x, unsigned long timeout);
113extern long wait_for_completion_killable_timeout(
114 struct completion *x, unsigned long timeout);
115extern bool try_wait_for_completion(struct completion *x);
116extern bool completion_done(struct completion *x);
117
118extern void complete(struct completion *);
119extern void complete_all(struct completion *);
120
121#endif
122