Linux kernel mirror (for testing)
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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)(struct timer_list *);
21 u32 flags;
22
23#ifdef CONFIG_LOCKDEP
24 struct lockdep_map lockdep_map;
25#endif
26};
27
28#ifdef CONFIG_LOCKDEP
29/*
30 * NB: because we have to copy the lockdep_map, setting the lockdep_map key
31 * (second argument) here is required, otherwise it could be initialised to
32 * the copy of the lockdep_map later! We use the pointer to and the string
33 * "<file>:<line>" as the key resp. the name of the lockdep_map.
34 */
35#define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn) \
36 .lockdep_map = STATIC_LOCKDEP_MAP_INIT(_kn, &_kn),
37#else
38#define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn)
39#endif
40
41/*
42 * A deferrable timer will work normally when the system is busy, but
43 * will not cause a CPU to come out of idle just to service it; instead,
44 * the timer will be serviced when the CPU eventually wakes up with a
45 * subsequent non-deferrable timer.
46 *
47 * An irqsafe timer is executed with IRQ disabled and it's safe to wait for
48 * the completion of the running instance from IRQ handlers, for example,
49 * by calling del_timer_sync().
50 *
51 * Note: The irq disabled callback execution is a special case for
52 * workqueue locking issues. It's not meant for executing random crap
53 * with interrupts disabled. Abuse is monitored!
54 */
55#define TIMER_CPUMASK 0x0003FFFF
56#define TIMER_MIGRATING 0x00040000
57#define TIMER_BASEMASK (TIMER_CPUMASK | TIMER_MIGRATING)
58#define TIMER_DEFERRABLE 0x00080000
59#define TIMER_PINNED 0x00100000
60#define TIMER_IRQSAFE 0x00200000
61#define TIMER_ARRAYSHIFT 22
62#define TIMER_ARRAYMASK 0xFFC00000
63
64#define TIMER_TRACE_FLAGMASK (TIMER_MIGRATING | TIMER_DEFERRABLE | TIMER_PINNED | TIMER_IRQSAFE)
65
66#define __TIMER_INITIALIZER(_function, _flags) { \
67 .entry = { .next = TIMER_ENTRY_STATIC }, \
68 .function = (_function), \
69 .flags = (_flags), \
70 __TIMER_LOCKDEP_MAP_INITIALIZER( \
71 __FILE__ ":" __stringify(__LINE__)) \
72 }
73
74#define DEFINE_TIMER(_name, _function) \
75 struct timer_list _name = \
76 __TIMER_INITIALIZER(_function, 0)
77
78/*
79 * LOCKDEP and DEBUG timer interfaces.
80 */
81void init_timer_key(struct timer_list *timer,
82 void (*func)(struct timer_list *), unsigned int flags,
83 const char *name, struct lock_class_key *key);
84
85#ifdef CONFIG_DEBUG_OBJECTS_TIMERS
86extern void init_timer_on_stack_key(struct timer_list *timer,
87 void (*func)(struct timer_list *),
88 unsigned int flags, const char *name,
89 struct lock_class_key *key);
90#else
91static inline void init_timer_on_stack_key(struct timer_list *timer,
92 void (*func)(struct timer_list *),
93 unsigned int flags,
94 const char *name,
95 struct lock_class_key *key)
96{
97 init_timer_key(timer, func, flags, name, key);
98}
99#endif
100
101#ifdef CONFIG_LOCKDEP
102#define __init_timer(_timer, _fn, _flags) \
103 do { \
104 static struct lock_class_key __key; \
105 init_timer_key((_timer), (_fn), (_flags), #_timer, &__key);\
106 } while (0)
107
108#define __init_timer_on_stack(_timer, _fn, _flags) \
109 do { \
110 static struct lock_class_key __key; \
111 init_timer_on_stack_key((_timer), (_fn), (_flags), \
112 #_timer, &__key); \
113 } while (0)
114#else
115#define __init_timer(_timer, _fn, _flags) \
116 init_timer_key((_timer), (_fn), (_flags), NULL, NULL)
117#define __init_timer_on_stack(_timer, _fn, _flags) \
118 init_timer_on_stack_key((_timer), (_fn), (_flags), NULL, NULL)
119#endif
120
121/**
122 * timer_setup - prepare a timer for first use
123 * @timer: the timer in question
124 * @callback: the function to call when timer expires
125 * @flags: any TIMER_* flags
126 *
127 * Regular timer initialization should use either DEFINE_TIMER() above,
128 * or timer_setup(). For timers on the stack, timer_setup_on_stack() must
129 * be used and must be balanced with a call to destroy_timer_on_stack().
130 */
131#define timer_setup(timer, callback, flags) \
132 __init_timer((timer), (callback), (flags))
133
134#define timer_setup_on_stack(timer, callback, flags) \
135 __init_timer_on_stack((timer), (callback), (flags))
136
137#ifdef CONFIG_DEBUG_OBJECTS_TIMERS
138extern void destroy_timer_on_stack(struct timer_list *timer);
139#else
140static inline void destroy_timer_on_stack(struct timer_list *timer) { }
141#endif
142
143#define from_timer(var, callback_timer, timer_fieldname) \
144 container_of(callback_timer, typeof(*var), timer_fieldname)
145
146/**
147 * timer_pending - is a timer pending?
148 * @timer: the timer in question
149 *
150 * timer_pending will tell whether a given timer is currently pending,
151 * or not. Callers must ensure serialization wrt. other operations done
152 * to this timer, eg. interrupt contexts, or other CPUs on SMP.
153 *
154 * return value: 1 if the timer is pending, 0 if not.
155 */
156static inline int timer_pending(const struct timer_list * timer)
157{
158 return timer->entry.pprev != NULL;
159}
160
161extern void add_timer_on(struct timer_list *timer, int cpu);
162extern int del_timer(struct timer_list * timer);
163extern int mod_timer(struct timer_list *timer, unsigned long expires);
164extern int mod_timer_pending(struct timer_list *timer, unsigned long expires);
165extern int timer_reduce(struct timer_list *timer, unsigned long expires);
166
167/*
168 * The jiffies value which is added to now, when there is no timer
169 * in the timer wheel:
170 */
171#define NEXT_TIMER_MAX_DELTA ((1UL << 30) - 1)
172
173extern void add_timer(struct timer_list *timer);
174
175extern int try_to_del_timer_sync(struct timer_list *timer);
176
177#ifdef CONFIG_SMP
178 extern int del_timer_sync(struct timer_list *timer);
179#else
180# define del_timer_sync(t) del_timer(t)
181#endif
182
183#define del_singleshot_timer_sync(t) del_timer_sync(t)
184
185extern void init_timers(void);
186extern void run_local_timers(void);
187struct hrtimer;
188extern enum hrtimer_restart it_real_fn(struct hrtimer *);
189
190#if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
191struct ctl_table;
192
193extern unsigned int sysctl_timer_migration;
194int timer_migration_handler(struct ctl_table *table, int write,
195 void __user *buffer, size_t *lenp,
196 loff_t *ppos);
197#endif
198
199unsigned long __round_jiffies(unsigned long j, int cpu);
200unsigned long __round_jiffies_relative(unsigned long j, int cpu);
201unsigned long round_jiffies(unsigned long j);
202unsigned long round_jiffies_relative(unsigned long j);
203
204unsigned long __round_jiffies_up(unsigned long j, int cpu);
205unsigned long __round_jiffies_up_relative(unsigned long j, int cpu);
206unsigned long round_jiffies_up(unsigned long j);
207unsigned long round_jiffies_up_relative(unsigned long j);
208
209#ifdef CONFIG_HOTPLUG_CPU
210int timers_dead_cpu(unsigned int cpu);
211#else
212#define timers_dead_cpu NULL
213#endif
214
215#endif