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 	int start_pid;
28 	void *start_site;
29 	char start_comm[16];
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 /*
52  * Note that all tvec_bases are 2 byte aligned and lower bit of
53  * base in timer_list is guaranteed to be zero. Use the LSB to
54  * indicate whether the timer is deferrable.
55  *
56  * A deferrable timer will work normally when the system is busy, but
57  * will not cause a CPU to come out of idle just to service it; instead,
58  * the timer will be serviced when the CPU eventually wakes up with a
59  * subsequent non-deferrable timer.
60  */
61 #define TBASE_DEFERRABLE_FLAG		(0x1)
62 
63 #define TIMER_INITIALIZER(_function, _expires, _data) {		\
64 		.entry = { .prev = TIMER_ENTRY_STATIC },	\
65 		.function = (_function),			\
66 		.expires = (_expires),				\
67 		.data = (_data),				\
68 		.base = &boot_tvec_bases,			\
69 		.slack = -1,					\
70 		__TIMER_LOCKDEP_MAP_INITIALIZER(		\
71 			__FILE__ ":" __stringify(__LINE__))	\
72 	}
73 
74 #define TBASE_MAKE_DEFERRED(ptr) ((struct tvec_base *)		\
75 		  ((unsigned char *)(ptr) + TBASE_DEFERRABLE_FLAG))
76 
77 #define TIMER_DEFERRED_INITIALIZER(_function, _expires, _data) {\
78 		.entry = { .prev = TIMER_ENTRY_STATIC },	\
79 		.function = (_function),			\
80 		.expires = (_expires),				\
81 		.data = (_data),				\
82 		.base = TBASE_MAKE_DEFERRED(&boot_tvec_bases),	\
83 		__TIMER_LOCKDEP_MAP_INITIALIZER(		\
84 			__FILE__ ":" __stringify(__LINE__))	\
85 	}
86 
87 #define DEFINE_TIMER(_name, _function, _expires, _data)		\
88 	struct timer_list _name =				\
89 		TIMER_INITIALIZER(_function, _expires, _data)
90 
91 void init_timer_key(struct timer_list *timer,
92 		    const char *name,
93 		    struct lock_class_key *key);
94 void init_timer_deferrable_key(struct timer_list *timer,
95 			       const char *name,
96 			       struct lock_class_key *key);
97 
98 #ifdef CONFIG_LOCKDEP
99 #define init_timer(timer)						\
100 	do {								\
101 		static struct lock_class_key __key;			\
102 		init_timer_key((timer), #timer, &__key);		\
103 	} while (0)
104 
105 #define init_timer_deferrable(timer)					\
106 	do {								\
107 		static struct lock_class_key __key;			\
108 		init_timer_deferrable_key((timer), #timer, &__key);	\
109 	} while (0)
110 
111 #define init_timer_on_stack(timer)					\
112 	do {								\
113 		static struct lock_class_key __key;			\
114 		init_timer_on_stack_key((timer), #timer, &__key);	\
115 	} while (0)
116 
117 #define setup_timer(timer, fn, data)					\
118 	do {								\
119 		static struct lock_class_key __key;			\
120 		setup_timer_key((timer), #timer, &__key, (fn), (data));\
121 	} while (0)
122 
123 #define setup_timer_on_stack(timer, fn, data)				\
124 	do {								\
125 		static struct lock_class_key __key;			\
126 		setup_timer_on_stack_key((timer), #timer, &__key,	\
127 					 (fn), (data));			\
128 	} while (0)
129 #define setup_deferrable_timer_on_stack(timer, fn, data)		\
130 	do {								\
131 		static struct lock_class_key __key;			\
132 		setup_deferrable_timer_on_stack_key((timer), #timer,	\
133 						    &__key, (fn),	\
134 						    (data));		\
135 	} while (0)
136 #else
137 #define init_timer(timer)\
138 	init_timer_key((timer), NULL, NULL)
139 #define init_timer_deferrable(timer)\
140 	init_timer_deferrable_key((timer), NULL, NULL)
141 #define init_timer_on_stack(timer)\
142 	init_timer_on_stack_key((timer), NULL, NULL)
143 #define setup_timer(timer, fn, data)\
144 	setup_timer_key((timer), NULL, NULL, (fn), (data))
145 #define setup_timer_on_stack(timer, fn, data)\
146 	setup_timer_on_stack_key((timer), NULL, NULL, (fn), (data))
147 #define setup_deferrable_timer_on_stack(timer, fn, data)\
148 	setup_deferrable_timer_on_stack_key((timer), NULL, NULL, (fn), (data))
149 #endif
150 
151 #ifdef CONFIG_DEBUG_OBJECTS_TIMERS
152 extern void init_timer_on_stack_key(struct timer_list *timer,
153 				    const char *name,
154 				    struct lock_class_key *key);
155 extern void destroy_timer_on_stack(struct timer_list *timer);
156 #else
destroy_timer_on_stack(struct timer_list * timer)157 static inline void destroy_timer_on_stack(struct timer_list *timer) { }
init_timer_on_stack_key(struct timer_list * timer,const char * name,struct lock_class_key * key)158 static inline void init_timer_on_stack_key(struct timer_list *timer,
159 					   const char *name,
160 					   struct lock_class_key *key)
161 {
162 	init_timer_key(timer, name, key);
163 }
164 #endif
165 
setup_timer_key(struct timer_list * timer,const char * name,struct lock_class_key * key,void (* function)(unsigned long),unsigned long data)166 static inline void setup_timer_key(struct timer_list * timer,
167 				const char *name,
168 				struct lock_class_key *key,
169 				void (*function)(unsigned long),
170 				unsigned long data)
171 {
172 	timer->function = function;
173 	timer->data = data;
174 	init_timer_key(timer, name, key);
175 }
176 
setup_timer_on_stack_key(struct timer_list * timer,const char * name,struct lock_class_key * key,void (* function)(unsigned long),unsigned long data)177 static inline void setup_timer_on_stack_key(struct timer_list *timer,
178 					const char *name,
179 					struct lock_class_key *key,
180 					void (*function)(unsigned long),
181 					unsigned long data)
182 {
183 	timer->function = function;
184 	timer->data = data;
185 	init_timer_on_stack_key(timer, name, key);
186 }
187 
188 extern void setup_deferrable_timer_on_stack_key(struct timer_list *timer,
189 						const char *name,
190 						struct lock_class_key *key,
191 						void (*function)(unsigned long),
192 						unsigned long data);
193 
194 /**
195  * timer_pending - is a timer pending?
196  * @timer: the timer in question
197  *
198  * timer_pending will tell whether a given timer is currently pending,
199  * or not. Callers must ensure serialization wrt. other operations done
200  * to this timer, eg. interrupt contexts, or other CPUs on SMP.
201  *
202  * return value: 1 if the timer is pending, 0 if not.
203  */
timer_pending(const struct timer_list * timer)204 static inline int timer_pending(const struct timer_list * timer)
205 {
206 	return timer->entry.next != NULL;
207 }
208 
209 extern void add_timer_on(struct timer_list *timer, int cpu);
210 extern int del_timer(struct timer_list * timer);
211 extern int mod_timer(struct timer_list *timer, unsigned long expires);
212 extern int mod_timer_pending(struct timer_list *timer, unsigned long expires);
213 extern int mod_timer_pinned(struct timer_list *timer, unsigned long expires);
214 
215 extern void set_timer_slack(struct timer_list *time, int slack_hz);
216 
217 #define TIMER_NOT_PINNED	0
218 #define TIMER_PINNED		1
219 /*
220  * The jiffies value which is added to now, when there is no timer
221  * in the timer wheel:
222  */
223 #define NEXT_TIMER_MAX_DELTA	((1UL << 30) - 1)
224 
225 /*
226  * Return when the next timer-wheel timeout occurs (in absolute jiffies),
227  * locks the timer base and does the comparison against the given
228  * jiffie.
229  */
230 extern unsigned long get_next_timer_interrupt(unsigned long now);
231 
232 /*
233  * Timer-statistics info:
234  */
235 #ifdef CONFIG_TIMER_STATS
236 
237 extern int timer_stats_active;
238 
239 #define TIMER_STATS_FLAG_DEFERRABLE	0x1
240 
241 extern void init_timer_stats(void);
242 
243 extern void timer_stats_update_stats(void *timer, pid_t pid, void *startf,
244 				     void *timerf, char *comm,
245 				     unsigned int timer_flag);
246 
247 extern void __timer_stats_timer_set_start_info(struct timer_list *timer,
248 					       void *addr);
249 
timer_stats_timer_set_start_info(struct timer_list * timer)250 static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
251 {
252 	if (likely(!timer_stats_active))
253 		return;
254 	__timer_stats_timer_set_start_info(timer, __builtin_return_address(0));
255 }
256 
timer_stats_timer_clear_start_info(struct timer_list * timer)257 static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
258 {
259 	timer->start_site = NULL;
260 }
261 #else
init_timer_stats(void)262 static inline void init_timer_stats(void)
263 {
264 }
265 
timer_stats_timer_set_start_info(struct timer_list * timer)266 static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
267 {
268 }
269 
timer_stats_timer_clear_start_info(struct timer_list * timer)270 static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
271 {
272 }
273 #endif
274 
275 extern void add_timer(struct timer_list *timer);
276 
277 extern int try_to_del_timer_sync(struct timer_list *timer);
278 
279 #ifdef CONFIG_SMP
280   extern int del_timer_sync(struct timer_list *timer);
281 #else
282 # define del_timer_sync(t)		del_timer(t)
283 #endif
284 
285 #define del_singleshot_timer_sync(t) del_timer_sync(t)
286 
287 extern void init_timers(void);
288 extern void run_local_timers(void);
289 struct hrtimer;
290 extern enum hrtimer_restart it_real_fn(struct hrtimer *);
291 
292 unsigned long __round_jiffies(unsigned long j, int cpu);
293 unsigned long __round_jiffies_relative(unsigned long j, int cpu);
294 unsigned long round_jiffies(unsigned long j);
295 unsigned long round_jiffies_relative(unsigned long j);
296 
297 unsigned long __round_jiffies_up(unsigned long j, int cpu);
298 unsigned long __round_jiffies_up_relative(unsigned long j, int cpu);
299 unsigned long round_jiffies_up(unsigned long j);
300 unsigned long round_jiffies_up_relative(unsigned long j);
301 
302 #endif
303