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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#ifdef CONFIG_LOCKDEP_COMPLETIONS
14#include <linux/lockdep.h>
15#endif
16
17/*
18 * struct completion - structure used to maintain state for a "completion"
19 *
20 * This is the opaque structure used to maintain the state for a "completion".
21 * Completions currently use a FIFO to queue threads that have to wait for
22 * the "completion" event.
23 *
24 * See also: complete(), wait_for_completion() (and friends _timeout,
25 * _interruptible, _interruptible_timeout, and _killable), init_completion(),
26 * reinit_completion(), and macros DECLARE_COMPLETION(),
27 * DECLARE_COMPLETION_ONSTACK().
28 */
29struct completion {
30 unsigned int done;
31 wait_queue_head_t wait;
32#ifdef CONFIG_LOCKDEP_COMPLETIONS
33 struct lockdep_map_cross map;
34#endif
35};
36
37#ifdef CONFIG_LOCKDEP_COMPLETIONS
38static inline void complete_acquire(struct completion *x)
39{
40 lock_acquire_exclusive((struct lockdep_map *)&x->map, 0, 0, NULL, _RET_IP_);
41}
42
43static inline void complete_release(struct completion *x)
44{
45 lock_release((struct lockdep_map *)&x->map, 0, _RET_IP_);
46}
47
48static inline void complete_release_commit(struct completion *x)
49{
50 lock_commit_crosslock((struct lockdep_map *)&x->map);
51}
52
53#define init_completion_map(x, m) \
54do { \
55 lockdep_init_map_crosslock((struct lockdep_map *)&(x)->map, \
56 (m)->name, (m)->key, 0); \
57 __init_completion(x); \
58} while (0)
59
60#define init_completion(x) \
61do { \
62 static struct lock_class_key __key; \
63 lockdep_init_map_crosslock((struct lockdep_map *)&(x)->map, \
64 "(completion)" #x, \
65 &__key, 0); \
66 __init_completion(x); \
67} while (0)
68#else
69#define init_completion_map(x, m) __init_completion(x)
70#define init_completion(x) __init_completion(x)
71static inline void complete_acquire(struct completion *x) {}
72static inline void complete_release(struct completion *x) {}
73static inline void complete_release_commit(struct completion *x) {}
74#endif
75
76#ifdef CONFIG_LOCKDEP_COMPLETIONS
77#define COMPLETION_INITIALIZER(work) \
78 { 0, __WAIT_QUEUE_HEAD_INITIALIZER((work).wait), \
79 STATIC_CROSS_LOCKDEP_MAP_INIT("(completion)" #work, &(work)) }
80#else
81#define COMPLETION_INITIALIZER(work) \
82 { 0, __WAIT_QUEUE_HEAD_INITIALIZER((work).wait) }
83#endif
84
85#define COMPLETION_INITIALIZER_ONSTACK_MAP(work, map) \
86 (*({ init_completion_map(&(work), &(map)); &(work); }))
87
88#define COMPLETION_INITIALIZER_ONSTACK(work) \
89 (*({ init_completion(&work); &work; }))
90
91/**
92 * DECLARE_COMPLETION - declare and initialize a completion structure
93 * @work: identifier for the completion structure
94 *
95 * This macro declares and initializes a completion structure. Generally used
96 * for static declarations. You should use the _ONSTACK variant for automatic
97 * variables.
98 */
99#define DECLARE_COMPLETION(work) \
100 struct completion work = COMPLETION_INITIALIZER(work)
101
102/*
103 * Lockdep needs to run a non-constant initializer for on-stack
104 * completions - so we use the _ONSTACK() variant for those that
105 * are on the kernel stack:
106 */
107/**
108 * DECLARE_COMPLETION_ONSTACK - declare and initialize a completion structure
109 * @work: identifier for the completion structure
110 *
111 * This macro declares and initializes a completion structure on the kernel
112 * stack.
113 */
114#ifdef CONFIG_LOCKDEP
115# define DECLARE_COMPLETION_ONSTACK(work) \
116 struct completion work = COMPLETION_INITIALIZER_ONSTACK(work)
117# define DECLARE_COMPLETION_ONSTACK_MAP(work, map) \
118 struct completion work = COMPLETION_INITIALIZER_ONSTACK_MAP(work, map)
119#else
120# define DECLARE_COMPLETION_ONSTACK(work) DECLARE_COMPLETION(work)
121# define DECLARE_COMPLETION_ONSTACK_MAP(work, map) DECLARE_COMPLETION(work)
122#endif
123
124/**
125 * init_completion - Initialize a dynamically allocated completion
126 * @x: pointer to completion structure that is to be initialized
127 *
128 * This inline function will initialize a dynamically created completion
129 * structure.
130 */
131static inline void __init_completion(struct completion *x)
132{
133 x->done = 0;
134 init_waitqueue_head(&x->wait);
135}
136
137/**
138 * reinit_completion - reinitialize a completion structure
139 * @x: pointer to completion structure that is to be reinitialized
140 *
141 * This inline function should be used to reinitialize a completion structure so it can
142 * be reused. This is especially important after complete_all() is used.
143 */
144static inline void reinit_completion(struct completion *x)
145{
146 x->done = 0;
147}
148
149extern void wait_for_completion(struct completion *);
150extern void wait_for_completion_io(struct completion *);
151extern int wait_for_completion_interruptible(struct completion *x);
152extern int wait_for_completion_killable(struct completion *x);
153extern unsigned long wait_for_completion_timeout(struct completion *x,
154 unsigned long timeout);
155extern unsigned long wait_for_completion_io_timeout(struct completion *x,
156 unsigned long timeout);
157extern long wait_for_completion_interruptible_timeout(
158 struct completion *x, unsigned long timeout);
159extern long wait_for_completion_killable_timeout(
160 struct completion *x, unsigned long timeout);
161extern bool try_wait_for_completion(struct completion *x);
162extern bool completion_done(struct completion *x);
163
164extern void complete(struct completion *);
165extern void complete_all(struct completion *);
166
167#endif