xref: /linux-6.15/include/linux/timer.h (revision 6e5c8381)
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 hlist_node	entry;
18 	unsigned long		expires;
19 	void			(*function)(unsigned long);
20 	unsigned long		data;
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_INITIALIZER(_function, _expires, _data, _flags) { \
65 		.entry = { .next = TIMER_ENTRY_STATIC },	\
66 		.function = (_function),			\
67 		.expires = (_expires),				\
68 		.data = (_data),				\
69 		.flags = (_flags),				\
70 		__TIMER_LOCKDEP_MAP_INITIALIZER(		\
71 			__FILE__ ":" __stringify(__LINE__))	\
72 	}
73 
74 #define TIMER_INITIALIZER(_function, _expires, _data)		\
75 	__TIMER_INITIALIZER((_function), (_expires), (_data), 0)
76 
77 #define TIMER_PINNED_INITIALIZER(_function, _expires, _data)	\
78 	__TIMER_INITIALIZER((_function), (_expires), (_data), TIMER_PINNED)
79 
80 #define TIMER_DEFERRED_INITIALIZER(_function, _expires, _data)	\
81 	__TIMER_INITIALIZER((_function), (_expires), (_data), TIMER_DEFERRABLE)
82 
83 #define TIMER_PINNED_DEFERRED_INITIALIZER(_function, _expires, _data)	\
84 	__TIMER_INITIALIZER((_function), (_expires), (_data), TIMER_DEFERRABLE | TIMER_PINNED)
85 
86 #define DEFINE_TIMER(_name, _function, _expires, _data)		\
87 	struct timer_list _name =				\
88 		TIMER_INITIALIZER(_function, _expires, _data)
89 
90 void init_timer_key(struct timer_list *timer, unsigned int flags,
91 		    const char *name, struct lock_class_key *key);
92 
93 #ifdef CONFIG_DEBUG_OBJECTS_TIMERS
94 extern void init_timer_on_stack_key(struct timer_list *timer,
95 				    unsigned int flags, const char *name,
96 				    struct lock_class_key *key);
97 extern void destroy_timer_on_stack(struct timer_list *timer);
98 #else
99 static inline void destroy_timer_on_stack(struct timer_list *timer) { }
100 static inline void init_timer_on_stack_key(struct timer_list *timer,
101 					   unsigned int flags, const char *name,
102 					   struct lock_class_key *key)
103 {
104 	init_timer_key(timer, flags, name, key);
105 }
106 #endif
107 
108 #ifdef CONFIG_LOCKDEP
109 #define __init_timer(_timer, _flags)					\
110 	do {								\
111 		static struct lock_class_key __key;			\
112 		init_timer_key((_timer), (_flags), #_timer, &__key);	\
113 	} while (0)
114 
115 #define __init_timer_on_stack(_timer, _flags)				\
116 	do {								\
117 		static struct lock_class_key __key;			\
118 		init_timer_on_stack_key((_timer), (_flags), #_timer, &__key); \
119 	} while (0)
120 #else
121 #define __init_timer(_timer, _flags)					\
122 	init_timer_key((_timer), (_flags), NULL, NULL)
123 #define __init_timer_on_stack(_timer, _flags)				\
124 	init_timer_on_stack_key((_timer), (_flags), NULL, NULL)
125 #endif
126 
127 #define init_timer(timer)						\
128 	__init_timer((timer), 0)
129 #define init_timer_pinned(timer)					\
130 	__init_timer((timer), TIMER_PINNED)
131 #define init_timer_deferrable(timer)					\
132 	__init_timer((timer), TIMER_DEFERRABLE)
133 #define init_timer_pinned_deferrable(timer)				\
134 	__init_timer((timer), TIMER_DEFERRABLE | TIMER_PINNED)
135 #define init_timer_on_stack(timer)					\
136 	__init_timer_on_stack((timer), 0)
137 
138 #define __setup_timer(_timer, _fn, _data, _flags)			\
139 	do {								\
140 		__init_timer((_timer), (_flags));			\
141 		(_timer)->function = (_fn);				\
142 		(_timer)->data = (_data);				\
143 	} while (0)
144 
145 #define __setup_timer_on_stack(_timer, _fn, _data, _flags)		\
146 	do {								\
147 		__init_timer_on_stack((_timer), (_flags));		\
148 		(_timer)->function = (_fn);				\
149 		(_timer)->data = (_data);				\
150 	} while (0)
151 
152 #define setup_timer(timer, fn, data)					\
153 	__setup_timer((timer), (fn), (data), 0)
154 #define setup_pinned_timer(timer, fn, data)				\
155 	__setup_timer((timer), (fn), (data), TIMER_PINNED)
156 #define setup_deferrable_timer(timer, fn, data)				\
157 	__setup_timer((timer), (fn), (data), TIMER_DEFERRABLE)
158 #define setup_pinned_deferrable_timer(timer, fn, data)			\
159 	__setup_timer((timer), (fn), (data), TIMER_DEFERRABLE | TIMER_PINNED)
160 #define setup_timer_on_stack(timer, fn, data)				\
161 	__setup_timer_on_stack((timer), (fn), (data), 0)
162 #define setup_pinned_timer_on_stack(timer, fn, data)			\
163 	__setup_timer_on_stack((timer), (fn), (data), TIMER_PINNED)
164 #define setup_deferrable_timer_on_stack(timer, fn, data)		\
165 	__setup_timer_on_stack((timer), (fn), (data), TIMER_DEFERRABLE)
166 #define setup_pinned_deferrable_timer_on_stack(timer, fn, data)		\
167 	__setup_timer_on_stack((timer), (fn), (data), TIMER_DEFERRABLE | TIMER_PINNED)
168 
169 /**
170  * timer_pending - is a timer pending?
171  * @timer: the timer in question
172  *
173  * timer_pending will tell whether a given timer is currently pending,
174  * or not. Callers must ensure serialization wrt. other operations done
175  * to this timer, eg. interrupt contexts, or other CPUs on SMP.
176  *
177  * return value: 1 if the timer is pending, 0 if not.
178  */
179 static inline int timer_pending(const struct timer_list * timer)
180 {
181 	return timer->entry.pprev != NULL;
182 }
183 
184 extern void add_timer_on(struct timer_list *timer, int cpu);
185 extern int del_timer(struct timer_list * timer);
186 extern int mod_timer(struct timer_list *timer, unsigned long expires);
187 extern int mod_timer_pending(struct timer_list *timer, unsigned long expires);
188 
189 /*
190  * The jiffies value which is added to now, when there is no timer
191  * in the timer wheel:
192  */
193 #define NEXT_TIMER_MAX_DELTA	((1UL << 30) - 1)
194 
195 extern void add_timer(struct timer_list *timer);
196 
197 extern int try_to_del_timer_sync(struct timer_list *timer);
198 
199 #ifdef CONFIG_SMP
200   extern int del_timer_sync(struct timer_list *timer);
201 #else
202 # define del_timer_sync(t)		del_timer(t)
203 #endif
204 
205 #define del_singleshot_timer_sync(t) del_timer_sync(t)
206 
207 extern void init_timers(void);
208 extern void run_local_timers(void);
209 struct hrtimer;
210 extern enum hrtimer_restart it_real_fn(struct hrtimer *);
211 
212 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
213 #include <linux/sysctl.h>
214 
215 extern unsigned int sysctl_timer_migration;
216 int timer_migration_handler(struct ctl_table *table, int write,
217 			    void __user *buffer, size_t *lenp,
218 			    loff_t *ppos);
219 #endif
220 
221 unsigned long __round_jiffies(unsigned long j, int cpu);
222 unsigned long __round_jiffies_relative(unsigned long j, int cpu);
223 unsigned long round_jiffies(unsigned long j);
224 unsigned long round_jiffies_relative(unsigned long j);
225 
226 unsigned long __round_jiffies_up(unsigned long j, int cpu);
227 unsigned long __round_jiffies_up_relative(unsigned long j, int cpu);
228 unsigned long round_jiffies_up(unsigned long j);
229 unsigned long round_jiffies_up_relative(unsigned long j);
230 
231 #ifdef CONFIG_HOTPLUG_CPU
232 int timers_dead_cpu(unsigned int cpu);
233 #else
234 #define timers_dead_cpu NULL
235 #endif
236 
237 #endif
238