Linux kernel mirror (for testing)
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linux
1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _LINUX_TIMER_H
3#define _LINUX_TIMER_H
4
5#include <linux/list.h>
6#include <linux/ktime.h>
7#include <linux/stddef.h>
8#include <linux/debugobjects.h>
9#include <linux/stringify.h>
10
11struct tvec_base;
12
13struct timer_list {
14 /*
15 * All fields that change during normal runtime grouped to the
16 * same cacheline
17 */
18 struct hlist_node entry;
19 unsigned long expires;
20 void (*function)(unsigned long);
21 unsigned long data;
22 u32 flags;
23
24#ifdef CONFIG_LOCKDEP
25 struct lockdep_map lockdep_map;
26#endif
27};
28
29#ifdef CONFIG_LOCKDEP
30/*
31 * NB: because we have to copy the lockdep_map, setting the lockdep_map key
32 * (second argument) here is required, otherwise it could be initialised to
33 * the copy of the lockdep_map later! We use the pointer to and the string
34 * "<file>:<line>" as the key resp. the name of the lockdep_map.
35 */
36#define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn) \
37 .lockdep_map = STATIC_LOCKDEP_MAP_INIT(_kn, &_kn),
38#else
39#define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn)
40#endif
41
42/*
43 * A deferrable timer will work normally when the system is busy, but
44 * will not cause a CPU to come out of idle just to service it; instead,
45 * the timer will be serviced when the CPU eventually wakes up with a
46 * subsequent non-deferrable timer.
47 *
48 * An irqsafe timer is executed with IRQ disabled and it's safe to wait for
49 * the completion of the running instance from IRQ handlers, for example,
50 * by calling del_timer_sync().
51 *
52 * Note: The irq disabled callback execution is a special case for
53 * workqueue locking issues. It's not meant for executing random crap
54 * with interrupts disabled. Abuse is monitored!
55 */
56#define TIMER_CPUMASK 0x0003FFFF
57#define TIMER_MIGRATING 0x00040000
58#define TIMER_BASEMASK (TIMER_CPUMASK | TIMER_MIGRATING)
59#define TIMER_DEFERRABLE 0x00080000
60#define TIMER_PINNED 0x00100000
61#define TIMER_IRQSAFE 0x00200000
62#define TIMER_ARRAYSHIFT 22
63#define TIMER_ARRAYMASK 0xFFC00000
64
65#define TIMER_TRACE_FLAGMASK (TIMER_MIGRATING | TIMER_DEFERRABLE | TIMER_PINNED | TIMER_IRQSAFE)
66
67#define TIMER_DATA_TYPE unsigned long
68#define TIMER_FUNC_TYPE void (*)(TIMER_DATA_TYPE)
69
70#define __TIMER_INITIALIZER(_function, _data, _flags) { \
71 .entry = { .next = TIMER_ENTRY_STATIC }, \
72 .function = (_function), \
73 .data = (_data), \
74 .flags = (_flags), \
75 __TIMER_LOCKDEP_MAP_INITIALIZER( \
76 __FILE__ ":" __stringify(__LINE__)) \
77 }
78
79#define DEFINE_TIMER(_name, _function) \
80 struct timer_list _name = \
81 __TIMER_INITIALIZER((TIMER_FUNC_TYPE)_function, 0, 0)
82
83void init_timer_key(struct timer_list *timer, unsigned int flags,
84 const char *name, struct lock_class_key *key);
85
86#ifdef CONFIG_DEBUG_OBJECTS_TIMERS
87extern void init_timer_on_stack_key(struct timer_list *timer,
88 unsigned int flags, const char *name,
89 struct lock_class_key *key);
90extern void destroy_timer_on_stack(struct timer_list *timer);
91#else
92static inline void destroy_timer_on_stack(struct timer_list *timer) { }
93static inline void init_timer_on_stack_key(struct timer_list *timer,
94 unsigned int flags, const char *name,
95 struct lock_class_key *key)
96{
97 init_timer_key(timer, flags, name, key);
98}
99#endif
100
101#ifdef CONFIG_LOCKDEP
102#define __init_timer(_timer, _flags) \
103 do { \
104 static struct lock_class_key __key; \
105 init_timer_key((_timer), (_flags), #_timer, &__key); \
106 } while (0)
107
108#define __init_timer_on_stack(_timer, _flags) \
109 do { \
110 static struct lock_class_key __key; \
111 init_timer_on_stack_key((_timer), (_flags), #_timer, &__key); \
112 } while (0)
113#else
114#define __init_timer(_timer, _flags) \
115 init_timer_key((_timer), (_flags), NULL, NULL)
116#define __init_timer_on_stack(_timer, _flags) \
117 init_timer_on_stack_key((_timer), (_flags), NULL, NULL)
118#endif
119
120#define init_timer(timer) \
121 __init_timer((timer), 0)
122
123#define __setup_timer(_timer, _fn, _data, _flags) \
124 do { \
125 __init_timer((_timer), (_flags)); \
126 (_timer)->function = (_fn); \
127 (_timer)->data = (_data); \
128 } while (0)
129
130#define __setup_timer_on_stack(_timer, _fn, _data, _flags) \
131 do { \
132 __init_timer_on_stack((_timer), (_flags)); \
133 (_timer)->function = (_fn); \
134 (_timer)->data = (_data); \
135 } while (0)
136
137#define setup_timer(timer, fn, data) \
138 __setup_timer((timer), (fn), (data), 0)
139#define setup_pinned_timer(timer, fn, data) \
140 __setup_timer((timer), (fn), (data), TIMER_PINNED)
141#define setup_deferrable_timer(timer, fn, data) \
142 __setup_timer((timer), (fn), (data), TIMER_DEFERRABLE)
143#define setup_pinned_deferrable_timer(timer, fn, data) \
144 __setup_timer((timer), (fn), (data), TIMER_DEFERRABLE | TIMER_PINNED)
145#define setup_timer_on_stack(timer, fn, data) \
146 __setup_timer_on_stack((timer), (fn), (data), 0)
147#define setup_pinned_timer_on_stack(timer, fn, data) \
148 __setup_timer_on_stack((timer), (fn), (data), TIMER_PINNED)
149#define setup_deferrable_timer_on_stack(timer, fn, data) \
150 __setup_timer_on_stack((timer), (fn), (data), TIMER_DEFERRABLE)
151#define setup_pinned_deferrable_timer_on_stack(timer, fn, data) \
152 __setup_timer_on_stack((timer), (fn), (data), TIMER_DEFERRABLE | TIMER_PINNED)
153
154#ifndef CONFIG_LOCKDEP
155static inline void timer_setup(struct timer_list *timer,
156 void (*callback)(struct timer_list *),
157 unsigned int flags)
158{
159 __setup_timer(timer, (TIMER_FUNC_TYPE)callback,
160 (TIMER_DATA_TYPE)timer, flags);
161}
162
163static inline void timer_setup_on_stack(struct timer_list *timer,
164 void (*callback)(struct timer_list *),
165 unsigned int flags)
166{
167 __setup_timer_on_stack(timer, (TIMER_FUNC_TYPE)callback,
168 (TIMER_DATA_TYPE)timer, flags);
169}
170#else
171/*
172 * Under LOCKDEP, the timer lock_class_key (set up in __init_timer) needs
173 * to be tied to the caller's context, so an inline (above) won't work. We
174 * do want to keep the inline for argument type checking, though.
175 */
176# define timer_setup(timer, callback, flags) \
177 __setup_timer((timer), (TIMER_FUNC_TYPE)(callback), \
178 (TIMER_DATA_TYPE)(timer), (flags))
179# define timer_setup_on_stack(timer, callback, flags) \
180 __setup_timer_on_stack((timer), \
181 (TIMER_FUNC_TYPE)(callback), \
182 (TIMER_DATA_TYPE)(timer), (flags))
183#endif
184
185#define from_timer(var, callback_timer, timer_fieldname) \
186 container_of(callback_timer, typeof(*var), timer_fieldname)
187
188/**
189 * timer_pending - is a timer pending?
190 * @timer: the timer in question
191 *
192 * timer_pending will tell whether a given timer is currently pending,
193 * or not. Callers must ensure serialization wrt. other operations done
194 * to this timer, eg. interrupt contexts, or other CPUs on SMP.
195 *
196 * return value: 1 if the timer is pending, 0 if not.
197 */
198static inline int timer_pending(const struct timer_list * timer)
199{
200 return timer->entry.pprev != NULL;
201}
202
203extern void add_timer_on(struct timer_list *timer, int cpu);
204extern int del_timer(struct timer_list * timer);
205extern int mod_timer(struct timer_list *timer, unsigned long expires);
206extern int mod_timer_pending(struct timer_list *timer, unsigned long expires);
207extern int timer_reduce(struct timer_list *timer, unsigned long expires);
208
209/*
210 * The jiffies value which is added to now, when there is no timer
211 * in the timer wheel:
212 */
213#define NEXT_TIMER_MAX_DELTA ((1UL << 30) - 1)
214
215extern void add_timer(struct timer_list *timer);
216
217extern int try_to_del_timer_sync(struct timer_list *timer);
218
219#ifdef CONFIG_SMP
220 extern int del_timer_sync(struct timer_list *timer);
221#else
222# define del_timer_sync(t) del_timer(t)
223#endif
224
225#define del_singleshot_timer_sync(t) del_timer_sync(t)
226
227extern void init_timers(void);
228extern void run_local_timers(void);
229struct hrtimer;
230extern enum hrtimer_restart it_real_fn(struct hrtimer *);
231
232#if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
233struct ctl_table;
234
235extern unsigned int sysctl_timer_migration;
236int timer_migration_handler(struct ctl_table *table, int write,
237 void __user *buffer, size_t *lenp,
238 loff_t *ppos);
239#endif
240
241unsigned long __round_jiffies(unsigned long j, int cpu);
242unsigned long __round_jiffies_relative(unsigned long j, int cpu);
243unsigned long round_jiffies(unsigned long j);
244unsigned long round_jiffies_relative(unsigned long j);
245
246unsigned long __round_jiffies_up(unsigned long j, int cpu);
247unsigned long __round_jiffies_up_relative(unsigned long j, int cpu);
248unsigned long round_jiffies_up(unsigned long j);
249unsigned long round_jiffies_up_relative(unsigned long j);
250
251#ifdef CONFIG_HOTPLUG_CPU
252int timers_dead_cpu(unsigned int cpu);
253#else
254#define timers_dead_cpu NULL
255#endif
256
257#endif