xref: /linux-6.15/include/linux/tick.h (revision f105dfec)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Tick related global functions
4  */
5 #ifndef _LINUX_TICK_H
6 #define _LINUX_TICK_H
7 
8 #include <linux/clockchips.h>
9 #include <linux/irqflags.h>
10 #include <linux/percpu.h>
11 #include <linux/context_tracking_state.h>
12 #include <linux/cpumask.h>
13 #include <linux/sched.h>
14 
15 #ifdef CONFIG_GENERIC_CLOCKEVENTS
16 extern void __init tick_init(void);
17 /* Should be core only, but ARM BL switcher requires it */
18 extern void tick_suspend_local(void);
19 /* Should be core only, but XEN resume magic and ARM BL switcher require it */
20 extern void tick_resume_local(void);
21 extern void tick_handover_do_timer(void);
22 extern void tick_cleanup_dead_cpu(int cpu);
23 #else /* CONFIG_GENERIC_CLOCKEVENTS */
24 static inline void tick_init(void) { }
25 static inline void tick_suspend_local(void) { }
26 static inline void tick_resume_local(void) { }
27 static inline void tick_handover_do_timer(void) { }
28 static inline void tick_cleanup_dead_cpu(int cpu) { }
29 #endif /* !CONFIG_GENERIC_CLOCKEVENTS */
30 
31 #if defined(CONFIG_GENERIC_CLOCKEVENTS) && defined(CONFIG_SUSPEND)
32 extern void tick_freeze(void);
33 extern void tick_unfreeze(void);
34 #else
35 static inline void tick_freeze(void) { }
36 static inline void tick_unfreeze(void) { }
37 #endif
38 
39 #ifdef CONFIG_TICK_ONESHOT
40 extern void tick_irq_enter(void);
41 #  ifndef arch_needs_cpu
42 #   define arch_needs_cpu() (0)
43 #  endif
44 # else
45 static inline void tick_irq_enter(void) { }
46 #endif
47 
48 #if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT)
49 extern void hotplug_cpu__broadcast_tick_pull(int dead_cpu);
50 #else
51 static inline void hotplug_cpu__broadcast_tick_pull(int dead_cpu) { }
52 #endif
53 
54 enum tick_broadcast_mode {
55 	TICK_BROADCAST_OFF,
56 	TICK_BROADCAST_ON,
57 	TICK_BROADCAST_FORCE,
58 };
59 
60 enum tick_broadcast_state {
61 	TICK_BROADCAST_EXIT,
62 	TICK_BROADCAST_ENTER,
63 };
64 
65 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
66 extern void tick_broadcast_control(enum tick_broadcast_mode mode);
67 #else
68 static inline void tick_broadcast_control(enum tick_broadcast_mode mode) { }
69 #endif /* BROADCAST */
70 
71 #if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_HOTPLUG_CPU)
72 extern void tick_offline_cpu(unsigned int cpu);
73 #else
74 static inline void tick_offline_cpu(unsigned int cpu) { }
75 #endif
76 
77 #ifdef CONFIG_GENERIC_CLOCKEVENTS
78 extern int tick_broadcast_oneshot_control(enum tick_broadcast_state state);
79 #else
80 static inline int tick_broadcast_oneshot_control(enum tick_broadcast_state state)
81 {
82 	return 0;
83 }
84 #endif
85 
86 static inline void tick_broadcast_enable(void)
87 {
88 	tick_broadcast_control(TICK_BROADCAST_ON);
89 }
90 static inline void tick_broadcast_disable(void)
91 {
92 	tick_broadcast_control(TICK_BROADCAST_OFF);
93 }
94 static inline void tick_broadcast_force(void)
95 {
96 	tick_broadcast_control(TICK_BROADCAST_FORCE);
97 }
98 static inline int tick_broadcast_enter(void)
99 {
100 	return tick_broadcast_oneshot_control(TICK_BROADCAST_ENTER);
101 }
102 static inline void tick_broadcast_exit(void)
103 {
104 	tick_broadcast_oneshot_control(TICK_BROADCAST_EXIT);
105 }
106 
107 enum tick_dep_bits {
108 	TICK_DEP_BIT_POSIX_TIMER	= 0,
109 	TICK_DEP_BIT_PERF_EVENTS	= 1,
110 	TICK_DEP_BIT_SCHED		= 2,
111 	TICK_DEP_BIT_CLOCK_UNSTABLE	= 3,
112 	TICK_DEP_BIT_RCU		= 4,
113 	TICK_DEP_BIT_RCU_EXP		= 5
114 };
115 #define TICK_DEP_BIT_MAX TICK_DEP_BIT_RCU_EXP
116 
117 #define TICK_DEP_MASK_NONE		0
118 #define TICK_DEP_MASK_POSIX_TIMER	(1 << TICK_DEP_BIT_POSIX_TIMER)
119 #define TICK_DEP_MASK_PERF_EVENTS	(1 << TICK_DEP_BIT_PERF_EVENTS)
120 #define TICK_DEP_MASK_SCHED		(1 << TICK_DEP_BIT_SCHED)
121 #define TICK_DEP_MASK_CLOCK_UNSTABLE	(1 << TICK_DEP_BIT_CLOCK_UNSTABLE)
122 #define TICK_DEP_MASK_RCU		(1 << TICK_DEP_BIT_RCU)
123 #define TICK_DEP_MASK_RCU_EXP		(1 << TICK_DEP_BIT_RCU_EXP)
124 
125 #ifdef CONFIG_NO_HZ_COMMON
126 extern bool tick_nohz_enabled;
127 extern bool tick_nohz_tick_stopped(void);
128 extern bool tick_nohz_tick_stopped_cpu(int cpu);
129 extern void tick_nohz_idle_stop_tick(void);
130 extern void tick_nohz_idle_retain_tick(void);
131 extern void tick_nohz_idle_restart_tick(void);
132 extern void tick_nohz_idle_enter(void);
133 extern void tick_nohz_idle_exit(void);
134 extern void tick_nohz_irq_exit(void);
135 extern bool tick_nohz_idle_got_tick(void);
136 extern ktime_t tick_nohz_get_next_hrtimer(void);
137 extern ktime_t tick_nohz_get_sleep_length(ktime_t *delta_next);
138 extern unsigned long tick_nohz_get_idle_calls(void);
139 extern unsigned long tick_nohz_get_idle_calls_cpu(int cpu);
140 extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time);
141 extern u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time);
142 
143 static inline void tick_nohz_idle_stop_tick_protected(void)
144 {
145 	local_irq_disable();
146 	tick_nohz_idle_stop_tick();
147 	local_irq_enable();
148 }
149 
150 #else /* !CONFIG_NO_HZ_COMMON */
151 #define tick_nohz_enabled (0)
152 static inline int tick_nohz_tick_stopped(void) { return 0; }
153 static inline int tick_nohz_tick_stopped_cpu(int cpu) { return 0; }
154 static inline void tick_nohz_idle_stop_tick(void) { }
155 static inline void tick_nohz_idle_retain_tick(void) { }
156 static inline void tick_nohz_idle_restart_tick(void) { }
157 static inline void tick_nohz_idle_enter(void) { }
158 static inline void tick_nohz_idle_exit(void) { }
159 static inline bool tick_nohz_idle_got_tick(void) { return false; }
160 static inline ktime_t tick_nohz_get_next_hrtimer(void)
161 {
162 	/* Next wake up is the tick period, assume it starts now */
163 	return ktime_add(ktime_get(), TICK_NSEC);
164 }
165 static inline ktime_t tick_nohz_get_sleep_length(ktime_t *delta_next)
166 {
167 	*delta_next = TICK_NSEC;
168 	return *delta_next;
169 }
170 static inline u64 get_cpu_idle_time_us(int cpu, u64 *unused) { return -1; }
171 static inline u64 get_cpu_iowait_time_us(int cpu, u64 *unused) { return -1; }
172 
173 static inline void tick_nohz_idle_stop_tick_protected(void) { }
174 #endif /* !CONFIG_NO_HZ_COMMON */
175 
176 #ifdef CONFIG_NO_HZ_FULL
177 extern bool tick_nohz_full_running;
178 extern cpumask_var_t tick_nohz_full_mask;
179 
180 static inline bool tick_nohz_full_enabled(void)
181 {
182 	if (!context_tracking_enabled())
183 		return false;
184 
185 	return tick_nohz_full_running;
186 }
187 
188 /*
189  * Check if a CPU is part of the nohz_full subset. Arrange for evaluating
190  * the cpu expression (typically smp_processor_id()) _after_ the static
191  * key.
192  */
193 #define tick_nohz_full_cpu(_cpu) ({					\
194 	bool __ret = false;						\
195 	if (tick_nohz_full_enabled())					\
196 		__ret = cpumask_test_cpu((_cpu), tick_nohz_full_mask);	\
197 	__ret;								\
198 })
199 
200 static inline void tick_nohz_full_add_cpus_to(struct cpumask *mask)
201 {
202 	if (tick_nohz_full_enabled())
203 		cpumask_or(mask, mask, tick_nohz_full_mask);
204 }
205 
206 extern void tick_nohz_dep_set(enum tick_dep_bits bit);
207 extern void tick_nohz_dep_clear(enum tick_dep_bits bit);
208 extern void tick_nohz_dep_set_cpu(int cpu, enum tick_dep_bits bit);
209 extern void tick_nohz_dep_clear_cpu(int cpu, enum tick_dep_bits bit);
210 extern void tick_nohz_dep_set_task(struct task_struct *tsk,
211 				   enum tick_dep_bits bit);
212 extern void tick_nohz_dep_clear_task(struct task_struct *tsk,
213 				     enum tick_dep_bits bit);
214 extern void tick_nohz_dep_set_signal(struct signal_struct *signal,
215 				     enum tick_dep_bits bit);
216 extern void tick_nohz_dep_clear_signal(struct signal_struct *signal,
217 				       enum tick_dep_bits bit);
218 
219 /*
220  * The below are tick_nohz_[set,clear]_dep() wrappers that optimize off-cases
221  * on top of static keys.
222  */
223 static inline void tick_dep_set(enum tick_dep_bits bit)
224 {
225 	if (tick_nohz_full_enabled())
226 		tick_nohz_dep_set(bit);
227 }
228 
229 static inline void tick_dep_clear(enum tick_dep_bits bit)
230 {
231 	if (tick_nohz_full_enabled())
232 		tick_nohz_dep_clear(bit);
233 }
234 
235 static inline void tick_dep_set_cpu(int cpu, enum tick_dep_bits bit)
236 {
237 	if (tick_nohz_full_cpu(cpu))
238 		tick_nohz_dep_set_cpu(cpu, bit);
239 }
240 
241 static inline void tick_dep_clear_cpu(int cpu, enum tick_dep_bits bit)
242 {
243 	if (tick_nohz_full_cpu(cpu))
244 		tick_nohz_dep_clear_cpu(cpu, bit);
245 }
246 
247 static inline void tick_dep_set_task(struct task_struct *tsk,
248 				     enum tick_dep_bits bit)
249 {
250 	if (tick_nohz_full_enabled())
251 		tick_nohz_dep_set_task(tsk, bit);
252 }
253 static inline void tick_dep_clear_task(struct task_struct *tsk,
254 				       enum tick_dep_bits bit)
255 {
256 	if (tick_nohz_full_enabled())
257 		tick_nohz_dep_clear_task(tsk, bit);
258 }
259 static inline void tick_dep_set_signal(struct signal_struct *signal,
260 				       enum tick_dep_bits bit)
261 {
262 	if (tick_nohz_full_enabled())
263 		tick_nohz_dep_set_signal(signal, bit);
264 }
265 static inline void tick_dep_clear_signal(struct signal_struct *signal,
266 					 enum tick_dep_bits bit)
267 {
268 	if (tick_nohz_full_enabled())
269 		tick_nohz_dep_clear_signal(signal, bit);
270 }
271 
272 extern void tick_nohz_full_kick_cpu(int cpu);
273 extern void __tick_nohz_task_switch(void);
274 extern void __init tick_nohz_full_setup(cpumask_var_t cpumask);
275 #else
276 static inline bool tick_nohz_full_enabled(void) { return false; }
277 static inline bool tick_nohz_full_cpu(int cpu) { return false; }
278 static inline void tick_nohz_full_add_cpus_to(struct cpumask *mask) { }
279 
280 static inline void tick_nohz_dep_set_cpu(int cpu, enum tick_dep_bits bit) { }
281 static inline void tick_nohz_dep_clear_cpu(int cpu, enum tick_dep_bits bit) { }
282 
283 static inline void tick_dep_set(enum tick_dep_bits bit) { }
284 static inline void tick_dep_clear(enum tick_dep_bits bit) { }
285 static inline void tick_dep_set_cpu(int cpu, enum tick_dep_bits bit) { }
286 static inline void tick_dep_clear_cpu(int cpu, enum tick_dep_bits bit) { }
287 static inline void tick_dep_set_task(struct task_struct *tsk,
288 				     enum tick_dep_bits bit) { }
289 static inline void tick_dep_clear_task(struct task_struct *tsk,
290 				       enum tick_dep_bits bit) { }
291 static inline void tick_dep_set_signal(struct signal_struct *signal,
292 				       enum tick_dep_bits bit) { }
293 static inline void tick_dep_clear_signal(struct signal_struct *signal,
294 					 enum tick_dep_bits bit) { }
295 
296 static inline void tick_nohz_full_kick_cpu(int cpu) { }
297 static inline void __tick_nohz_task_switch(void) { }
298 static inline void tick_nohz_full_setup(cpumask_var_t cpumask) { }
299 #endif
300 
301 static inline void tick_nohz_task_switch(void)
302 {
303 	if (tick_nohz_full_enabled())
304 		__tick_nohz_task_switch();
305 }
306 
307 #endif
308