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 at least 4 byte aligned and lower two bits
53 * of base in timer_list is guaranteed to be zero. Use them for flags.
54 *
55 * A deferrable timer will work normally when the system is busy, but
56 * will not cause a CPU to come out of idle just to service it; instead,
57 * the timer will be serviced when the CPU eventually wakes up with a
58 * subsequent non-deferrable timer.
59 *
60 * An irqsafe timer is executed with IRQ disabled and it's safe to wait for
61 * the completion of the running instance from IRQ handlers, for example,
62 * by calling del_timer_sync().
63 *
64 * Note: The irq disabled callback execution is a special case for
65 * workqueue locking issues. It's not meant for executing random crap
66 * with interrupts disabled. Abuse is monitored!
67 */
68 #define TIMER_DEFERRABLE 0x1LU
69 #define TIMER_IRQSAFE 0x2LU
70
71 #define TIMER_FLAG_MASK 0x3LU
72
73 #define __TIMER_INITIALIZER(_function, _expires, _data, _flags) { \
74 .entry = { .prev = TIMER_ENTRY_STATIC }, \
75 .function = (_function), \
76 .expires = (_expires), \
77 .data = (_data), \
78 .base = (void *)((unsigned long)&boot_tvec_bases + (_flags)), \
79 .slack = -1, \
80 __TIMER_LOCKDEP_MAP_INITIALIZER( \
81 __FILE__ ":" __stringify(__LINE__)) \
82 }
83
84 #define TIMER_INITIALIZER(_function, _expires, _data) \
85 __TIMER_INITIALIZER((_function), (_expires), (_data), 0)
86
87 #define TIMER_DEFERRED_INITIALIZER(_function, _expires, _data) \
88 __TIMER_INITIALIZER((_function), (_expires), (_data), TIMER_DEFERRABLE)
89
90 #define DEFINE_TIMER(_name, _function, _expires, _data) \
91 struct timer_list _name = \
92 TIMER_INITIALIZER(_function, _expires, _data)
93
94 void init_timer_key(struct timer_list *timer, unsigned int flags,
95 const char *name, struct lock_class_key *key);
96
97 #ifdef CONFIG_DEBUG_OBJECTS_TIMERS
98 extern void init_timer_on_stack_key(struct timer_list *timer,
99 unsigned int flags, const char *name,
100 struct lock_class_key *key);
101 extern void destroy_timer_on_stack(struct timer_list *timer);
102 #else
destroy_timer_on_stack(struct timer_list * timer)103 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)104 static inline void init_timer_on_stack_key(struct timer_list *timer,
105 unsigned int flags, const char *name,
106 struct lock_class_key *key)
107 {
108 init_timer_key(timer, flags, name, key);
109 }
110 #endif
111
112 #ifdef CONFIG_LOCKDEP
113 #define __init_timer(_timer, _flags) \
114 do { \
115 static struct lock_class_key __key; \
116 init_timer_key((_timer), (_flags), #_timer, &__key); \
117 } while (0)
118
119 #define __init_timer_on_stack(_timer, _flags) \
120 do { \
121 static struct lock_class_key __key; \
122 init_timer_on_stack_key((_timer), (_flags), #_timer, &__key); \
123 } while (0)
124 #else
125 #define __init_timer(_timer, _flags) \
126 init_timer_key((_timer), (_flags), NULL, NULL)
127 #define __init_timer_on_stack(_timer, _flags) \
128 init_timer_on_stack_key((_timer), (_flags), NULL, NULL)
129 #endif
130
131 #define init_timer(timer) \
132 __init_timer((timer), 0)
133 #define init_timer_deferrable(timer) \
134 __init_timer((timer), TIMER_DEFERRABLE)
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_timer_on_stack(timer, fn, data) \
155 __setup_timer_on_stack((timer), (fn), (data), 0)
156 #define setup_deferrable_timer_on_stack(timer, fn, data) \
157 __setup_timer_on_stack((timer), (fn), (data), TIMER_DEFERRABLE)
158
159 /**
160 * timer_pending - is a timer pending?
161 * @timer: the timer in question
162 *
163 * timer_pending will tell whether a given timer is currently pending,
164 * or not. Callers must ensure serialization wrt. other operations done
165 * to this timer, eg. interrupt contexts, or other CPUs on SMP.
166 *
167 * return value: 1 if the timer is pending, 0 if not.
168 */
timer_pending(const struct timer_list * timer)169 static inline int timer_pending(const struct timer_list * timer)
170 {
171 return timer->entry.next != NULL;
172 }
173
174 extern void add_timer_on(struct timer_list *timer, int cpu);
175 extern int del_timer(struct timer_list * timer);
176 extern int mod_timer(struct timer_list *timer, unsigned long expires);
177 extern int mod_timer_pending(struct timer_list *timer, unsigned long expires);
178 extern int mod_timer_pinned(struct timer_list *timer, unsigned long expires);
179
180 extern void set_timer_slack(struct timer_list *time, int slack_hz);
181
182 #define TIMER_NOT_PINNED 0
183 #define TIMER_PINNED 1
184 /*
185 * The jiffies value which is added to now, when there is no timer
186 * in the timer wheel:
187 */
188 #define NEXT_TIMER_MAX_DELTA ((1UL << 30) - 1)
189
190 /*
191 * Return when the next timer-wheel timeout occurs (in absolute jiffies),
192 * locks the timer base and does the comparison against the given
193 * jiffie.
194 */
195 extern unsigned long get_next_timer_interrupt(unsigned long now);
196
197 /*
198 * Timer-statistics info:
199 */
200 #ifdef CONFIG_TIMER_STATS
201
202 extern int timer_stats_active;
203
204 #define TIMER_STATS_FLAG_DEFERRABLE 0x1
205
206 extern void init_timer_stats(void);
207
208 extern void timer_stats_update_stats(void *timer, pid_t pid, void *startf,
209 void *timerf, char *comm,
210 unsigned int timer_flag);
211
212 extern void __timer_stats_timer_set_start_info(struct timer_list *timer,
213 void *addr);
214
timer_stats_timer_set_start_info(struct timer_list * timer)215 static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
216 {
217 if (likely(!timer_stats_active))
218 return;
219 __timer_stats_timer_set_start_info(timer, __builtin_return_address(0));
220 }
221
timer_stats_timer_clear_start_info(struct timer_list * timer)222 static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
223 {
224 timer->start_site = NULL;
225 }
226 #else
init_timer_stats(void)227 static inline void init_timer_stats(void)
228 {
229 }
230
timer_stats_timer_set_start_info(struct timer_list * timer)231 static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
232 {
233 }
234
timer_stats_timer_clear_start_info(struct timer_list * timer)235 static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
236 {
237 }
238 #endif
239
240 extern void add_timer(struct timer_list *timer);
241
242 extern int try_to_del_timer_sync(struct timer_list *timer);
243
244 #ifdef CONFIG_SMP
245 extern int del_timer_sync(struct timer_list *timer);
246 #else
247 # define del_timer_sync(t) del_timer(t)
248 #endif
249
250 #define del_singleshot_timer_sync(t) del_timer_sync(t)
251
252 extern void init_timers(void);
253 extern void run_local_timers(void);
254 struct hrtimer;
255 extern enum hrtimer_restart it_real_fn(struct hrtimer *);
256
257 unsigned long __round_jiffies(unsigned long j, int cpu);
258 unsigned long __round_jiffies_relative(unsigned long j, int cpu);
259 unsigned long round_jiffies(unsigned long j);
260 unsigned long round_jiffies_relative(unsigned long j);
261
262 unsigned long __round_jiffies_up(unsigned long j, int cpu);
263 unsigned long __round_jiffies_up_relative(unsigned long j, int cpu);
264 unsigned long round_jiffies_up(unsigned long j);
265 unsigned long round_jiffies_up_relative(unsigned long j);
266
267 #endif
268