xref: /linux-6.15/include/linux/timer.h (revision df92b408)
1 #ifndef _LINUX_TIMER_H
2 #define _LINUX_TIMER_H
3 
4 #include <linux/list.h>
5 #include <linux/ktime.h>
6 #include <linux/stddef.h>
7 #include <linux/debugobjects.h>
8 #include <linux/stringify.h>
9 
10 struct tvec_base;
11 
12 struct timer_list {
13 	/*
14 	 * All fields that change during normal runtime grouped to the
15 	 * same cacheline
16 	 */
17 	struct list_head entry;
18 	unsigned long expires;
19 	struct tvec_base *base;
20 
21 	void (*function)(unsigned long);
22 	unsigned long data;
23 
24 	int slack;
25 
26 #ifdef CONFIG_TIMER_STATS
27 	void *start_site;
28 	char start_comm[16];
29 	int start_pid;
30 #endif
31 #ifdef CONFIG_LOCKDEP
32 	struct lockdep_map lockdep_map;
33 #endif
34 };
35 
36 extern struct tvec_base boot_tvec_bases;
37 
38 #ifdef CONFIG_LOCKDEP
39 /*
40  * NB: because we have to copy the lockdep_map, setting the lockdep_map key
41  * (second argument) here is required, otherwise it could be initialised to
42  * the copy of the lockdep_map later! We use the pointer to and the string
43  * "<file>:<line>" as the key resp. the name of the lockdep_map.
44  */
45 #define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn)				\
46 	.lockdep_map = STATIC_LOCKDEP_MAP_INIT(_kn, &_kn),
47 #else
48 #define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn)
49 #endif
50 
51 #define TIMER_INITIALIZER(_function, _expires, _data) {		\
52 		.entry = { .prev = TIMER_ENTRY_STATIC },	\
53 		.function = (_function),			\
54 		.expires = (_expires),				\
55 		.data = (_data),				\
56 		.base = &boot_tvec_bases,			\
57 		__TIMER_LOCKDEP_MAP_INITIALIZER(		\
58 			__FILE__ ":" __stringify(__LINE__))	\
59 	}
60 
61 #define DEFINE_TIMER(_name, _function, _expires, _data)		\
62 	struct timer_list _name =				\
63 		TIMER_INITIALIZER(_function, _expires, _data)
64 
65 void init_timer_key(struct timer_list *timer,
66 		    const char *name,
67 		    struct lock_class_key *key);
68 void init_timer_deferrable_key(struct timer_list *timer,
69 			       const char *name,
70 			       struct lock_class_key *key);
71 
72 #ifdef CONFIG_LOCKDEP
73 #define init_timer(timer)						\
74 	do {								\
75 		static struct lock_class_key __key;			\
76 		init_timer_key((timer), #timer, &__key);		\
77 	} while (0)
78 
79 #define init_timer_deferrable(timer)					\
80 	do {								\
81 		static struct lock_class_key __key;			\
82 		init_timer_deferrable_key((timer), #timer, &__key);	\
83 	} while (0)
84 
85 #define init_timer_on_stack(timer)					\
86 	do {								\
87 		static struct lock_class_key __key;			\
88 		init_timer_on_stack_key((timer), #timer, &__key);	\
89 	} while (0)
90 
91 #define setup_timer(timer, fn, data)					\
92 	do {								\
93 		static struct lock_class_key __key;			\
94 		setup_timer_key((timer), #timer, &__key, (fn), (data));\
95 	} while (0)
96 
97 #define setup_timer_on_stack(timer, fn, data)				\
98 	do {								\
99 		static struct lock_class_key __key;			\
100 		setup_timer_on_stack_key((timer), #timer, &__key,	\
101 					 (fn), (data));			\
102 	} while (0)
103 #else
104 #define init_timer(timer)\
105 	init_timer_key((timer), NULL, NULL)
106 #define init_timer_deferrable(timer)\
107 	init_timer_deferrable_key((timer), NULL, NULL)
108 #define init_timer_on_stack(timer)\
109 	init_timer_on_stack_key((timer), NULL, NULL)
110 #define setup_timer(timer, fn, data)\
111 	setup_timer_key((timer), NULL, NULL, (fn), (data))
112 #define setup_timer_on_stack(timer, fn, data)\
113 	setup_timer_on_stack_key((timer), NULL, NULL, (fn), (data))
114 #endif
115 
116 #ifdef CONFIG_DEBUG_OBJECTS_TIMERS
117 extern void init_timer_on_stack_key(struct timer_list *timer,
118 				    const char *name,
119 				    struct lock_class_key *key);
120 extern void destroy_timer_on_stack(struct timer_list *timer);
121 #else
122 static inline void destroy_timer_on_stack(struct timer_list *timer) { }
123 static inline void init_timer_on_stack_key(struct timer_list *timer,
124 					   const char *name,
125 					   struct lock_class_key *key)
126 {
127 	init_timer_key(timer, name, key);
128 }
129 #endif
130 
131 static inline void setup_timer_key(struct timer_list * timer,
132 				const char *name,
133 				struct lock_class_key *key,
134 				void (*function)(unsigned long),
135 				unsigned long data)
136 {
137 	timer->function = function;
138 	timer->data = data;
139 	init_timer_key(timer, name, key);
140 }
141 
142 static inline void setup_timer_on_stack_key(struct timer_list *timer,
143 					const char *name,
144 					struct lock_class_key *key,
145 					void (*function)(unsigned long),
146 					unsigned long data)
147 {
148 	timer->function = function;
149 	timer->data = data;
150 	init_timer_on_stack_key(timer, name, key);
151 }
152 
153 /**
154  * timer_pending - is a timer pending?
155  * @timer: the timer in question
156  *
157  * timer_pending will tell whether a given timer is currently pending,
158  * or not. Callers must ensure serialization wrt. other operations done
159  * to this timer, eg. interrupt contexts, or other CPUs on SMP.
160  *
161  * return value: 1 if the timer is pending, 0 if not.
162  */
163 static inline int timer_pending(const struct timer_list * timer)
164 {
165 	return timer->entry.next != NULL;
166 }
167 
168 extern void add_timer_on(struct timer_list *timer, int cpu);
169 extern int del_timer(struct timer_list * timer);
170 extern int mod_timer(struct timer_list *timer, unsigned long expires);
171 extern int mod_timer_pending(struct timer_list *timer, unsigned long expires);
172 extern int mod_timer_pinned(struct timer_list *timer, unsigned long expires);
173 
174 extern void set_timer_slack(struct timer_list *time, int slack_hz);
175 
176 #define TIMER_NOT_PINNED	0
177 #define TIMER_PINNED		1
178 /*
179  * The jiffies value which is added to now, when there is no timer
180  * in the timer wheel:
181  */
182 #define NEXT_TIMER_MAX_DELTA	((1UL << 30) - 1)
183 
184 /*
185  * Return when the next timer-wheel timeout occurs (in absolute jiffies),
186  * locks the timer base and does the comparison against the given
187  * jiffie.
188  */
189 extern unsigned long get_next_timer_interrupt(unsigned long now);
190 
191 /*
192  * Timer-statistics info:
193  */
194 #ifdef CONFIG_TIMER_STATS
195 
196 extern int timer_stats_active;
197 
198 #define TIMER_STATS_FLAG_DEFERRABLE	0x1
199 
200 extern void init_timer_stats(void);
201 
202 extern void timer_stats_update_stats(void *timer, pid_t pid, void *startf,
203 				     void *timerf, char *comm,
204 				     unsigned int timer_flag);
205 
206 extern void __timer_stats_timer_set_start_info(struct timer_list *timer,
207 					       void *addr);
208 
209 static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
210 {
211 	if (likely(!timer_stats_active))
212 		return;
213 	__timer_stats_timer_set_start_info(timer, __builtin_return_address(0));
214 }
215 
216 static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
217 {
218 	timer->start_site = NULL;
219 }
220 #else
221 static inline void init_timer_stats(void)
222 {
223 }
224 
225 static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
226 {
227 }
228 
229 static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
230 {
231 }
232 #endif
233 
234 extern void add_timer(struct timer_list *timer);
235 
236 #ifdef CONFIG_SMP
237   extern int try_to_del_timer_sync(struct timer_list *timer);
238   extern int del_timer_sync(struct timer_list *timer);
239 #else
240 # define try_to_del_timer_sync(t)	del_timer(t)
241 # define del_timer_sync(t)		del_timer(t)
242 #endif
243 
244 #define del_singleshot_timer_sync(t) del_timer_sync(t)
245 
246 extern void init_timers(void);
247 extern void run_local_timers(void);
248 struct hrtimer;
249 extern enum hrtimer_restart it_real_fn(struct hrtimer *);
250 
251 unsigned long __round_jiffies(unsigned long j, int cpu);
252 unsigned long __round_jiffies_relative(unsigned long j, int cpu);
253 unsigned long round_jiffies(unsigned long j);
254 unsigned long round_jiffies_relative(unsigned long j);
255 
256 unsigned long __round_jiffies_up(unsigned long j, int cpu);
257 unsigned long __round_jiffies_up_relative(unsigned long j, int cpu);
258 unsigned long round_jiffies_up(unsigned long j);
259 unsigned long round_jiffies_up_relative(unsigned long j);
260 
261 #endif
262