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 timer_list { |
12 | /* |
13 | * All fields that change during normal runtime grouped to the |
14 | * same cacheline |
15 | */ |
16 | struct hlist_node entry; |
17 | unsigned long expires; |
18 | void (*function)(struct timer_list *); |
19 | u32 flags; |
20 | |
21 | #ifdef CONFIG_LOCKDEP |
22 | struct lockdep_map lockdep_map; |
23 | #endif |
24 | }; |
25 | |
26 | #ifdef CONFIG_LOCKDEP |
27 | /* |
28 | * NB: because we have to copy the lockdep_map, setting the lockdep_map key |
29 | * (second argument) here is required, otherwise it could be initialised to |
30 | * the copy of the lockdep_map later! We use the pointer to and the string |
31 | * "<file>:<line>" as the key resp. the name of the lockdep_map. |
32 | */ |
33 | #define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn) \ |
34 | .lockdep_map = STATIC_LOCKDEP_MAP_INIT(_kn, &_kn), |
35 | #else |
36 | #define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn) |
37 | #endif |
38 | |
39 | /* |
40 | * A deferrable timer will work normally when the system is busy, but |
41 | * will not cause a CPU to come out of idle just to service it; instead, |
42 | * the timer will be serviced when the CPU eventually wakes up with a |
43 | * subsequent non-deferrable timer. |
44 | * |
45 | * An irqsafe timer is executed with IRQ disabled and it's safe to wait for |
46 | * the completion of the running instance from IRQ handlers, for example, |
47 | * by calling del_timer_sync(). |
48 | * |
49 | * Note: The irq disabled callback execution is a special case for |
50 | * workqueue locking issues. It's not meant for executing random crap |
51 | * with interrupts disabled. Abuse is monitored! |
52 | */ |
53 | #define TIMER_CPUMASK 0x0003FFFF |
54 | #define TIMER_MIGRATING 0x00040000 |
55 | #define TIMER_BASEMASK (TIMER_CPUMASK | TIMER_MIGRATING) |
56 | #define TIMER_DEFERRABLE 0x00080000 |
57 | #define TIMER_PINNED 0x00100000 |
58 | #define TIMER_IRQSAFE 0x00200000 |
59 | #define TIMER_ARRAYSHIFT 22 |
60 | #define TIMER_ARRAYMASK 0xFFC00000 |
61 | |
62 | #define TIMER_TRACE_FLAGMASK (TIMER_MIGRATING | TIMER_DEFERRABLE | TIMER_PINNED | TIMER_IRQSAFE) |
63 | |
64 | #define __TIMER_INITIALIZER(_function, _flags) { \ |
65 | .entry = { .next = TIMER_ENTRY_STATIC }, \ |
66 | .function = (_function), \ |
67 | .flags = (_flags), \ |
68 | __TIMER_LOCKDEP_MAP_INITIALIZER( \ |
69 | __FILE__ ":" __stringify(__LINE__)) \ |
70 | } |
71 | |
72 | #define DEFINE_TIMER(_name, _function) \ |
73 | struct timer_list _name = \ |
74 | __TIMER_INITIALIZER(_function, 0) |
75 | |
76 | /* |
77 | * LOCKDEP and DEBUG timer interfaces. |
78 | */ |
79 | void init_timer_key(struct timer_list *timer, |
80 | void (*func)(struct timer_list *), unsigned int flags, |
81 | const char *name, struct lock_class_key *key); |
82 | |
83 | #ifdef CONFIG_DEBUG_OBJECTS_TIMERS |
84 | extern void init_timer_on_stack_key(struct timer_list *timer, |
85 | void (*func)(struct timer_list *), |
86 | unsigned int flags, const char *name, |
87 | struct lock_class_key *key); |
88 | #else |
89 | static inline void init_timer_on_stack_key(struct timer_list *timer, |
90 | void (*func)(struct timer_list *), |
91 | unsigned int flags, |
92 | const char *name, |
93 | struct lock_class_key *key) |
94 | { |
95 | init_timer_key(timer, func, flags, name, key); |
96 | } |
97 | #endif |
98 | |
99 | #ifdef CONFIG_LOCKDEP |
100 | #define __init_timer(_timer, _fn, _flags) \ |
101 | do { \ |
102 | static struct lock_class_key __key; \ |
103 | init_timer_key((_timer), (_fn), (_flags), #_timer, &__key);\ |
104 | } while (0) |
105 | |
106 | #define __init_timer_on_stack(_timer, _fn, _flags) \ |
107 | do { \ |
108 | static struct lock_class_key __key; \ |
109 | init_timer_on_stack_key((_timer), (_fn), (_flags), \ |
110 | #_timer, &__key); \ |
111 | } while (0) |
112 | #else |
113 | #define __init_timer(_timer, _fn, _flags) \ |
114 | init_timer_key((_timer), (_fn), (_flags), NULL, NULL) |
115 | #define __init_timer_on_stack(_timer, _fn, _flags) \ |
116 | init_timer_on_stack_key((_timer), (_fn), (_flags), NULL, NULL) |
117 | #endif |
118 | |
119 | /** |
120 | * timer_setup - prepare a timer for first use |
121 | * @timer: the timer in question |
122 | * @callback: the function to call when timer expires |
123 | * @flags: any TIMER_* flags |
124 | * |
125 | * Regular timer initialization should use either DEFINE_TIMER() above, |
126 | * or timer_setup(). For timers on the stack, timer_setup_on_stack() must |
127 | * be used and must be balanced with a call to destroy_timer_on_stack(). |
128 | */ |
129 | #define timer_setup(timer, callback, flags) \ |
130 | __init_timer((timer), (callback), (flags)) |
131 | |
132 | #define timer_setup_on_stack(timer, callback, flags) \ |
133 | __init_timer_on_stack((timer), (callback), (flags)) |
134 | |
135 | #ifdef CONFIG_DEBUG_OBJECTS_TIMERS |
136 | extern void destroy_timer_on_stack(struct timer_list *timer); |
137 | #else |
138 | static inline void destroy_timer_on_stack(struct timer_list *timer) { } |
139 | #endif |
140 | |
141 | #define from_timer(var, callback_timer, timer_fieldname) \ |
142 | container_of(callback_timer, typeof(*var), timer_fieldname) |
143 | |
144 | /** |
145 | * timer_pending - is a timer pending? |
146 | * @timer: the timer in question |
147 | * |
148 | * timer_pending will tell whether a given timer is currently pending, |
149 | * or not. Callers must ensure serialization wrt. other operations done |
150 | * to this timer, eg. interrupt contexts, or other CPUs on SMP. |
151 | * |
152 | * return value: 1 if the timer is pending, 0 if not. |
153 | */ |
154 | static inline int timer_pending(const struct timer_list * timer) |
155 | { |
156 | return timer->entry.pprev != NULL; |
157 | } |
158 | |
159 | extern void add_timer_on(struct timer_list *timer, int cpu); |
160 | extern int del_timer(struct timer_list * timer); |
161 | extern int mod_timer(struct timer_list *timer, unsigned long expires); |
162 | extern int mod_timer_pending(struct timer_list *timer, unsigned long expires); |
163 | extern int timer_reduce(struct timer_list *timer, unsigned long expires); |
164 | |
165 | /* |
166 | * The jiffies value which is added to now, when there is no timer |
167 | * in the timer wheel: |
168 | */ |
169 | #define NEXT_TIMER_MAX_DELTA ((1UL << 30) - 1) |
170 | |
171 | extern void add_timer(struct timer_list *timer); |
172 | |
173 | extern int try_to_del_timer_sync(struct timer_list *timer); |
174 | |
175 | #ifdef CONFIG_SMP |
176 | extern int del_timer_sync(struct timer_list *timer); |
177 | #else |
178 | # define del_timer_sync(t) del_timer(t) |
179 | #endif |
180 | |
181 | #define del_singleshot_timer_sync(t) del_timer_sync(t) |
182 | |
183 | extern void init_timers(void); |
184 | extern void run_local_timers(void); |
185 | struct hrtimer; |
186 | extern enum hrtimer_restart it_real_fn(struct hrtimer *); |
187 | |
188 | #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON) |
189 | struct ctl_table; |
190 | |
191 | extern unsigned int sysctl_timer_migration; |
192 | int timer_migration_handler(struct ctl_table *table, int write, |
193 | void __user *buffer, size_t *lenp, |
194 | loff_t *ppos); |
195 | #endif |
196 | |
197 | unsigned long __round_jiffies(unsigned long j, int cpu); |
198 | unsigned long __round_jiffies_relative(unsigned long j, int cpu); |
199 | unsigned long round_jiffies(unsigned long j); |
200 | unsigned long round_jiffies_relative(unsigned long j); |
201 | |
202 | unsigned long __round_jiffies_up(unsigned long j, int cpu); |
203 | unsigned long __round_jiffies_up_relative(unsigned long j, int cpu); |
204 | unsigned long round_jiffies_up(unsigned long j); |
205 | unsigned long round_jiffies_up_relative(unsigned long j); |
206 | |
207 | #ifdef CONFIG_HOTPLUG_CPU |
208 | int timers_prepare_cpu(unsigned int cpu); |
209 | int timers_dead_cpu(unsigned int cpu); |
210 | #else |
211 | #define timers_prepare_cpu NULL |
212 | #define timers_dead_cpu NULL |
213 | #endif |
214 | |
215 | #endif |
216 | |