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
11 struct tvec_base;
12
13 struct 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_INITIALIZER(_function, _expires, _data, _flags) { \
68 .entry = { .next = TIMER_ENTRY_STATIC }, \
69 .function = (_function), \
70 .expires = (_expires), \
71 .data = (_data), \
72 .flags = (_flags), \
73 __TIMER_LOCKDEP_MAP_INITIALIZER( \
74 __FILE__ ":" __stringify(__LINE__)) \
75 }
76
77 #define TIMER_INITIALIZER(_function, _expires, _data) \
78 __TIMER_INITIALIZER((_function), (_expires), (_data), 0)
79
80 #define TIMER_PINNED_INITIALIZER(_function, _expires, _data) \
81 __TIMER_INITIALIZER((_function), (_expires), (_data), TIMER_PINNED)
82
83 #define TIMER_DEFERRED_INITIALIZER(_function, _expires, _data) \
84 __TIMER_INITIALIZER((_function), (_expires), (_data), TIMER_DEFERRABLE)
85
86 #define TIMER_PINNED_DEFERRED_INITIALIZER(_function, _expires, _data) \
87 __TIMER_INITIALIZER((_function), (_expires), (_data), TIMER_DEFERRABLE | TIMER_PINNED)
88
89 #define DEFINE_TIMER(_name, _function, _expires, _data) \
90 struct timer_list _name = \
91 TIMER_INITIALIZER(_function, _expires, _data)
92
93 void init_timer_key(struct timer_list *timer, unsigned int flags,
94 const char *name, struct lock_class_key *key);
95
96 #ifdef CONFIG_DEBUG_OBJECTS_TIMERS
97 extern void init_timer_on_stack_key(struct timer_list *timer,
98 unsigned int flags, const char *name,
99 struct lock_class_key *key);
100 extern void destroy_timer_on_stack(struct timer_list *timer);
101 #else
destroy_timer_on_stack(struct timer_list * timer)102 static inline void destroy_timer_on_stack(struct timer_list *timer) { }
init_timer_on_stack_key(struct timer_list * timer,unsigned int flags,const char * name,struct lock_class_key * key)103 static inline void init_timer_on_stack_key(struct timer_list *timer,
104 unsigned int flags, const char *name,
105 struct lock_class_key *key)
106 {
107 init_timer_key(timer, flags, name, key);
108 }
109 #endif
110
111 #ifdef CONFIG_LOCKDEP
112 #define __init_timer(_timer, _flags) \
113 do { \
114 static struct lock_class_key __key; \
115 init_timer_key((_timer), (_flags), #_timer, &__key); \
116 } while (0)
117
118 #define __init_timer_on_stack(_timer, _flags) \
119 do { \
120 static struct lock_class_key __key; \
121 init_timer_on_stack_key((_timer), (_flags), #_timer, &__key); \
122 } while (0)
123 #else
124 #define __init_timer(_timer, _flags) \
125 init_timer_key((_timer), (_flags), NULL, NULL)
126 #define __init_timer_on_stack(_timer, _flags) \
127 init_timer_on_stack_key((_timer), (_flags), NULL, NULL)
128 #endif
129
130 #define init_timer(timer) \
131 __init_timer((timer), 0)
132 #define init_timer_pinned(timer) \
133 __init_timer((timer), TIMER_PINNED)
134 #define init_timer_deferrable(timer) \
135 __init_timer((timer), TIMER_DEFERRABLE)
136 #define init_timer_pinned_deferrable(timer) \
137 __init_timer((timer), TIMER_DEFERRABLE | TIMER_PINNED)
138 #define init_timer_on_stack(timer) \
139 __init_timer_on_stack((timer), 0)
140
141 #define __setup_timer(_timer, _fn, _data, _flags) \
142 do { \
143 __init_timer((_timer), (_flags)); \
144 (_timer)->function = (_fn); \
145 (_timer)->data = (_data); \
146 } while (0)
147
148 #define __setup_timer_on_stack(_timer, _fn, _data, _flags) \
149 do { \
150 __init_timer_on_stack((_timer), (_flags)); \
151 (_timer)->function = (_fn); \
152 (_timer)->data = (_data); \
153 } while (0)
154
155 #define setup_timer(timer, fn, data) \
156 __setup_timer((timer), (fn), (data), 0)
157 #define setup_pinned_timer(timer, fn, data) \
158 __setup_timer((timer), (fn), (data), TIMER_PINNED)
159 #define setup_deferrable_timer(timer, fn, data) \
160 __setup_timer((timer), (fn), (data), TIMER_DEFERRABLE)
161 #define setup_pinned_deferrable_timer(timer, fn, data) \
162 __setup_timer((timer), (fn), (data), TIMER_DEFERRABLE | TIMER_PINNED)
163 #define setup_timer_on_stack(timer, fn, data) \
164 __setup_timer_on_stack((timer), (fn), (data), 0)
165 #define setup_pinned_timer_on_stack(timer, fn, data) \
166 __setup_timer_on_stack((timer), (fn), (data), TIMER_PINNED)
167 #define setup_deferrable_timer_on_stack(timer, fn, data) \
168 __setup_timer_on_stack((timer), (fn), (data), TIMER_DEFERRABLE)
169 #define setup_pinned_deferrable_timer_on_stack(timer, fn, data) \
170 __setup_timer_on_stack((timer), (fn), (data), TIMER_DEFERRABLE | TIMER_PINNED)
171
172 #define TIMER_DATA_TYPE unsigned long
173 #define TIMER_FUNC_TYPE void (*)(TIMER_DATA_TYPE)
174
timer_setup(struct timer_list * timer,void (* callback)(struct timer_list *),unsigned int flags)175 static inline void timer_setup(struct timer_list *timer,
176 void (*callback)(struct timer_list *),
177 unsigned int flags)
178 {
179 __setup_timer(timer, (TIMER_FUNC_TYPE)callback,
180 (TIMER_DATA_TYPE)timer, flags);
181 }
182
183 #define from_timer(var, callback_timer, timer_fieldname) \
184 container_of(callback_timer, typeof(*var), timer_fieldname)
185
186 /**
187 * timer_pending - is a timer pending?
188 * @timer: the timer in question
189 *
190 * timer_pending will tell whether a given timer is currently pending,
191 * or not. Callers must ensure serialization wrt. other operations done
192 * to this timer, eg. interrupt contexts, or other CPUs on SMP.
193 *
194 * return value: 1 if the timer is pending, 0 if not.
195 */
timer_pending(const struct timer_list * timer)196 static inline int timer_pending(const struct timer_list * timer)
197 {
198 return timer->entry.pprev != NULL;
199 }
200
201 extern void add_timer_on(struct timer_list *timer, int cpu);
202 extern int del_timer(struct timer_list * timer);
203 extern int mod_timer(struct timer_list *timer, unsigned long expires);
204 extern int mod_timer_pending(struct timer_list *timer, unsigned long expires);
205
206 /*
207 * The jiffies value which is added to now, when there is no timer
208 * in the timer wheel:
209 */
210 #define NEXT_TIMER_MAX_DELTA ((1UL << 30) - 1)
211
212 extern void add_timer(struct timer_list *timer);
213
214 extern int try_to_del_timer_sync(struct timer_list *timer);
215
216 #ifdef CONFIG_SMP
217 extern int del_timer_sync(struct timer_list *timer);
218 #else
219 # define del_timer_sync(t) del_timer(t)
220 #endif
221
222 #define del_singleshot_timer_sync(t) del_timer_sync(t)
223
224 extern void init_timers(void);
225 extern void run_local_timers(void);
226 struct hrtimer;
227 extern enum hrtimer_restart it_real_fn(struct hrtimer *);
228
229 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
230 struct ctl_table;
231
232 extern unsigned int sysctl_timer_migration;
233 int timer_migration_handler(struct ctl_table *table, int write,
234 void __user *buffer, size_t *lenp,
235 loff_t *ppos);
236 #endif
237
238 unsigned long __round_jiffies(unsigned long j, int cpu);
239 unsigned long __round_jiffies_relative(unsigned long j, int cpu);
240 unsigned long round_jiffies(unsigned long j);
241 unsigned long round_jiffies_relative(unsigned long j);
242
243 unsigned long __round_jiffies_up(unsigned long j, int cpu);
244 unsigned long __round_jiffies_up_relative(unsigned long j, int cpu);
245 unsigned long round_jiffies_up(unsigned long j);
246 unsigned long round_jiffies_up_relative(unsigned long j);
247
248 #ifdef CONFIG_HOTPLUG_CPU
249 int timers_prepare_cpu(unsigned int cpu);
250 int timers_dead_cpu(unsigned int cpu);
251 #else
252 #define timers_prepare_cpu NULL
253 #define timers_dead_cpu NULL
254 #endif
255
256 #endif
257