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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#include <linux/rcupdate.h>
15#include <linux/static_key.h>
16
17#ifdef CONFIG_GENERIC_CLOCKEVENTS
18extern void __init tick_init(void);
19/* Should be core only, but ARM BL switcher requires it */
20extern void tick_suspend_local(void);
21/* Should be core only, but XEN resume magic and ARM BL switcher require it */
22extern void tick_resume_local(void);
23extern void tick_cleanup_dead_cpu(int cpu);
24#else /* CONFIG_GENERIC_CLOCKEVENTS */
25static inline void tick_init(void) { }
26static inline void tick_suspend_local(void) { }
27static inline void tick_resume_local(void) { }
28static inline void tick_cleanup_dead_cpu(int cpu) { }
29#endif /* !CONFIG_GENERIC_CLOCKEVENTS */
30
31#if defined(CONFIG_GENERIC_CLOCKEVENTS) && defined(CONFIG_HOTPLUG_CPU)
32extern int tick_cpu_dying(unsigned int cpu);
33extern void tick_assert_timekeeping_handover(void);
34#else
35#define tick_cpu_dying NULL
36static inline void tick_assert_timekeeping_handover(void) { }
37#endif
38
39#if defined(CONFIG_GENERIC_CLOCKEVENTS) && defined(CONFIG_SUSPEND)
40extern void tick_freeze(void);
41extern void tick_unfreeze(void);
42#else
43static inline void tick_freeze(void) { }
44static inline void tick_unfreeze(void) { }
45#endif
46
47#ifdef CONFIG_TICK_ONESHOT
48extern void tick_irq_enter(void);
49# ifndef arch_needs_cpu
50# define arch_needs_cpu() (0)
51# endif
52# else
53static inline void tick_irq_enter(void) { }
54#endif
55
56#if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT)
57extern void hotplug_cpu__broadcast_tick_pull(int dead_cpu);
58#else
59static inline void hotplug_cpu__broadcast_tick_pull(int dead_cpu) { }
60#endif
61
62enum tick_broadcast_mode {
63 TICK_BROADCAST_OFF,
64 TICK_BROADCAST_ON,
65 TICK_BROADCAST_FORCE,
66};
67
68enum tick_broadcast_state {
69 TICK_BROADCAST_EXIT,
70 TICK_BROADCAST_ENTER,
71};
72
73extern struct static_key_false arch_needs_tick_broadcast;
74
75#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
76extern void tick_broadcast_control(enum tick_broadcast_mode mode);
77#else
78static inline void tick_broadcast_control(enum tick_broadcast_mode mode) { }
79#endif /* BROADCAST */
80
81#ifdef CONFIG_GENERIC_CLOCKEVENTS
82extern int tick_broadcast_oneshot_control(enum tick_broadcast_state state);
83#else
84static inline int tick_broadcast_oneshot_control(enum tick_broadcast_state state)
85{
86 return 0;
87}
88#endif
89
90static inline void tick_broadcast_enable(void)
91{
92 tick_broadcast_control(TICK_BROADCAST_ON);
93}
94static inline void tick_broadcast_disable(void)
95{
96 tick_broadcast_control(TICK_BROADCAST_OFF);
97}
98static inline void tick_broadcast_force(void)
99{
100 tick_broadcast_control(TICK_BROADCAST_FORCE);
101}
102static inline int tick_broadcast_enter(void)
103{
104 return tick_broadcast_oneshot_control(TICK_BROADCAST_ENTER);
105}
106static inline void tick_broadcast_exit(void)
107{
108 tick_broadcast_oneshot_control(TICK_BROADCAST_EXIT);
109}
110
111enum tick_dep_bits {
112 TICK_DEP_BIT_POSIX_TIMER = 0,
113 TICK_DEP_BIT_PERF_EVENTS = 1,
114 TICK_DEP_BIT_SCHED = 2,
115 TICK_DEP_BIT_CLOCK_UNSTABLE = 3,
116 TICK_DEP_BIT_RCU = 4,
117 TICK_DEP_BIT_RCU_EXP = 5
118};
119#define TICK_DEP_BIT_MAX TICK_DEP_BIT_RCU_EXP
120
121#define TICK_DEP_MASK_NONE 0
122#define TICK_DEP_MASK_POSIX_TIMER (1 << TICK_DEP_BIT_POSIX_TIMER)
123#define TICK_DEP_MASK_PERF_EVENTS (1 << TICK_DEP_BIT_PERF_EVENTS)
124#define TICK_DEP_MASK_SCHED (1 << TICK_DEP_BIT_SCHED)
125#define TICK_DEP_MASK_CLOCK_UNSTABLE (1 << TICK_DEP_BIT_CLOCK_UNSTABLE)
126#define TICK_DEP_MASK_RCU (1 << TICK_DEP_BIT_RCU)
127#define TICK_DEP_MASK_RCU_EXP (1 << TICK_DEP_BIT_RCU_EXP)
128
129#ifdef CONFIG_NO_HZ_COMMON
130extern bool tick_nohz_enabled;
131extern bool tick_nohz_tick_stopped(void);
132extern bool tick_nohz_tick_stopped_cpu(int cpu);
133extern void tick_nohz_idle_stop_tick(void);
134extern void tick_nohz_idle_retain_tick(void);
135extern void tick_nohz_idle_restart_tick(void);
136extern void tick_nohz_idle_enter(void);
137extern void tick_nohz_idle_exit(void);
138extern void tick_nohz_irq_exit(void);
139extern bool tick_nohz_idle_got_tick(void);
140extern ktime_t tick_nohz_get_next_hrtimer(void);
141extern ktime_t tick_nohz_get_sleep_length(ktime_t *delta_next);
142extern unsigned long tick_nohz_get_idle_calls_cpu(int cpu);
143extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time);
144extern u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time);
145#else /* !CONFIG_NO_HZ_COMMON */
146#define tick_nohz_enabled (0)
147static inline int tick_nohz_tick_stopped(void) { return 0; }
148static inline int tick_nohz_tick_stopped_cpu(int cpu) { return 0; }
149static inline void tick_nohz_idle_stop_tick(void) { }
150static inline void tick_nohz_idle_retain_tick(void) { }
151static inline void tick_nohz_idle_restart_tick(void) { }
152static inline void tick_nohz_idle_enter(void) { }
153static inline void tick_nohz_idle_exit(void) { }
154static inline bool tick_nohz_idle_got_tick(void) { return false; }
155static inline ktime_t tick_nohz_get_next_hrtimer(void)
156{
157 /* Next wake up is the tick period, assume it starts now */
158 return ktime_add(ktime_get(), TICK_NSEC);
159}
160static inline ktime_t tick_nohz_get_sleep_length(ktime_t *delta_next)
161{
162 *delta_next = TICK_NSEC;
163 return *delta_next;
164}
165static inline u64 get_cpu_idle_time_us(int cpu, u64 *unused) { return -1; }
166static inline u64 get_cpu_iowait_time_us(int cpu, u64 *unused) { return -1; }
167#endif /* !CONFIG_NO_HZ_COMMON */
168
169/*
170 * Mask of CPUs that are nohz_full.
171 *
172 * Users should be guarded by CONFIG_NO_HZ_FULL or a tick_nohz_full_cpu()
173 * check.
174 */
175extern cpumask_var_t tick_nohz_full_mask;
176
177#ifdef CONFIG_NO_HZ_FULL
178extern bool tick_nohz_full_running;
179
180static 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
200static 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
206extern void tick_nohz_dep_set(enum tick_dep_bits bit);
207extern void tick_nohz_dep_clear(enum tick_dep_bits bit);
208extern void tick_nohz_dep_set_cpu(int cpu, enum tick_dep_bits bit);
209extern void tick_nohz_dep_clear_cpu(int cpu, enum tick_dep_bits bit);
210extern void tick_nohz_dep_set_task(struct task_struct *tsk,
211 enum tick_dep_bits bit);
212extern void tick_nohz_dep_clear_task(struct task_struct *tsk,
213 enum tick_dep_bits bit);
214extern void tick_nohz_dep_set_signal(struct task_struct *tsk,
215 enum tick_dep_bits bit);
216extern void tick_nohz_dep_clear_signal(struct signal_struct *signal,
217 enum tick_dep_bits bit);
218extern bool tick_nohz_cpu_hotpluggable(unsigned int cpu);
219
220/*
221 * The below are tick_nohz_[set,clear]_dep() wrappers that optimize off-cases
222 * on top of static keys.
223 */
224static inline void tick_dep_set(enum tick_dep_bits bit)
225{
226 if (tick_nohz_full_enabled())
227 tick_nohz_dep_set(bit);
228}
229
230static inline void tick_dep_clear(enum tick_dep_bits bit)
231{
232 if (tick_nohz_full_enabled())
233 tick_nohz_dep_clear(bit);
234}
235
236static inline void tick_dep_set_cpu(int cpu, enum tick_dep_bits bit)
237{
238 if (tick_nohz_full_cpu(cpu))
239 tick_nohz_dep_set_cpu(cpu, bit);
240}
241
242static inline void tick_dep_clear_cpu(int cpu, enum tick_dep_bits bit)
243{
244 if (tick_nohz_full_cpu(cpu))
245 tick_nohz_dep_clear_cpu(cpu, bit);
246}
247
248static inline void tick_dep_set_task(struct task_struct *tsk,
249 enum tick_dep_bits bit)
250{
251 if (tick_nohz_full_enabled())
252 tick_nohz_dep_set_task(tsk, bit);
253}
254static inline void tick_dep_clear_task(struct task_struct *tsk,
255 enum tick_dep_bits bit)
256{
257 if (tick_nohz_full_enabled())
258 tick_nohz_dep_clear_task(tsk, bit);
259}
260static inline void tick_dep_set_signal(struct task_struct *tsk,
261 enum tick_dep_bits bit)
262{
263 if (tick_nohz_full_enabled())
264 tick_nohz_dep_set_signal(tsk, bit);
265}
266static inline void tick_dep_clear_signal(struct signal_struct *signal,
267 enum tick_dep_bits bit)
268{
269 if (tick_nohz_full_enabled())
270 tick_nohz_dep_clear_signal(signal, bit);
271}
272
273extern void tick_nohz_full_kick_cpu(int cpu);
274extern void __tick_nohz_task_switch(void);
275extern void __init tick_nohz_full_setup(cpumask_var_t cpumask);
276#else
277static inline bool tick_nohz_full_enabled(void) { return false; }
278static inline bool tick_nohz_full_cpu(int cpu) { return false; }
279static inline void tick_nohz_full_add_cpus_to(struct cpumask *mask) { }
280
281static inline void tick_nohz_dep_set_cpu(int cpu, enum tick_dep_bits bit) { }
282static inline void tick_nohz_dep_clear_cpu(int cpu, enum tick_dep_bits bit) { }
283static inline bool tick_nohz_cpu_hotpluggable(unsigned int cpu) { return true; }
284
285static inline void tick_dep_set(enum tick_dep_bits bit) { }
286static inline void tick_dep_clear(enum tick_dep_bits bit) { }
287static inline void tick_dep_set_cpu(int cpu, enum tick_dep_bits bit) { }
288static inline void tick_dep_clear_cpu(int cpu, enum tick_dep_bits bit) { }
289static inline void tick_dep_set_task(struct task_struct *tsk,
290 enum tick_dep_bits bit) { }
291static inline void tick_dep_clear_task(struct task_struct *tsk,
292 enum tick_dep_bits bit) { }
293static inline void tick_dep_set_signal(struct task_struct *tsk,
294 enum tick_dep_bits bit) { }
295static inline void tick_dep_clear_signal(struct signal_struct *signal,
296 enum tick_dep_bits bit) { }
297
298static inline void tick_nohz_full_kick_cpu(int cpu) { }
299static inline void __tick_nohz_task_switch(void) { }
300static inline void tick_nohz_full_setup(cpumask_var_t cpumask) { }
301#endif
302
303static inline void tick_nohz_task_switch(void)
304{
305 if (tick_nohz_full_enabled())
306 __tick_nohz_task_switch();
307}
308
309static inline void tick_nohz_user_enter_prepare(void)
310{
311 if (tick_nohz_full_cpu(smp_processor_id()))
312 rcu_nocb_flush_deferred_wakeup();
313}
314
315#endif