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
18 extern void __init tick_init(void);
19 /* Should be core only, but ARM BL switcher requires it */
20 extern void tick_suspend_local(void);
21 /* Should be core only, but XEN resume magic and ARM BL switcher require it */
22 extern void tick_resume_local(void);
23 #else /* CONFIG_GENERIC_CLOCKEVENTS */
tick_init(void)24 static inline void tick_init(void) { }
tick_suspend_local(void)25 static inline void tick_suspend_local(void) { }
tick_resume_local(void)26 static inline void tick_resume_local(void) { }
27 #endif /* !CONFIG_GENERIC_CLOCKEVENTS */
28
29 #if defined(CONFIG_GENERIC_CLOCKEVENTS) && defined(CONFIG_HOTPLUG_CPU)
30 extern int tick_cpu_dying(unsigned int cpu);
31 extern void tick_assert_timekeeping_handover(void);
32 #else
33 #define tick_cpu_dying NULL
tick_assert_timekeeping_handover(void)34 static inline void tick_assert_timekeeping_handover(void) { }
35 #endif
36
37 #if defined(CONFIG_GENERIC_CLOCKEVENTS) && defined(CONFIG_SUSPEND)
38 extern void tick_freeze(void);
39 extern void tick_unfreeze(void);
40 #else
tick_freeze(void)41 static inline void tick_freeze(void) { }
tick_unfreeze(void)42 static inline void tick_unfreeze(void) { }
43 #endif
44
45 #ifdef CONFIG_TICK_ONESHOT
46 extern void tick_irq_enter(void);
47 # ifndef arch_needs_cpu
48 # define arch_needs_cpu() (0)
49 # endif
50 # else
tick_irq_enter(void)51 static inline void tick_irq_enter(void) { }
52 #endif
53
54 #if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT)
55 extern void hotplug_cpu__broadcast_tick_pull(int dead_cpu);
56 #else
hotplug_cpu__broadcast_tick_pull(int dead_cpu)57 static inline void hotplug_cpu__broadcast_tick_pull(int dead_cpu) { }
58 #endif
59
60 enum tick_broadcast_mode {
61 TICK_BROADCAST_OFF,
62 TICK_BROADCAST_ON,
63 TICK_BROADCAST_FORCE,
64 };
65
66 enum tick_broadcast_state {
67 TICK_BROADCAST_EXIT,
68 TICK_BROADCAST_ENTER,
69 };
70
71 extern struct static_key_false arch_needs_tick_broadcast;
72
73 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
74 extern void tick_broadcast_control(enum tick_broadcast_mode mode);
75 #else
tick_broadcast_control(enum tick_broadcast_mode mode)76 static inline void tick_broadcast_control(enum tick_broadcast_mode mode) { }
77 #endif /* BROADCAST */
78
79 #ifdef CONFIG_GENERIC_CLOCKEVENTS
80 extern int tick_broadcast_oneshot_control(enum tick_broadcast_state state);
81 #else
tick_broadcast_oneshot_control(enum tick_broadcast_state state)82 static inline int tick_broadcast_oneshot_control(enum tick_broadcast_state state)
83 {
84 return 0;
85 }
86 #endif
87
tick_broadcast_enable(void)88 static inline void tick_broadcast_enable(void)
89 {
90 tick_broadcast_control(TICK_BROADCAST_ON);
91 }
tick_broadcast_disable(void)92 static inline void tick_broadcast_disable(void)
93 {
94 tick_broadcast_control(TICK_BROADCAST_OFF);
95 }
tick_broadcast_force(void)96 static inline void tick_broadcast_force(void)
97 {
98 tick_broadcast_control(TICK_BROADCAST_FORCE);
99 }
tick_broadcast_enter(void)100 static inline int tick_broadcast_enter(void)
101 {
102 return tick_broadcast_oneshot_control(TICK_BROADCAST_ENTER);
103 }
tick_broadcast_exit(void)104 static inline void tick_broadcast_exit(void)
105 {
106 tick_broadcast_oneshot_control(TICK_BROADCAST_EXIT);
107 }
108
109 enum tick_dep_bits {
110 TICK_DEP_BIT_POSIX_TIMER = 0,
111 TICK_DEP_BIT_PERF_EVENTS = 1,
112 TICK_DEP_BIT_SCHED = 2,
113 TICK_DEP_BIT_CLOCK_UNSTABLE = 3,
114 TICK_DEP_BIT_RCU = 4,
115 TICK_DEP_BIT_RCU_EXP = 5
116 };
117 #define TICK_DEP_BIT_MAX TICK_DEP_BIT_RCU_EXP
118
119 #define TICK_DEP_MASK_NONE 0
120 #define TICK_DEP_MASK_POSIX_TIMER (1 << TICK_DEP_BIT_POSIX_TIMER)
121 #define TICK_DEP_MASK_PERF_EVENTS (1 << TICK_DEP_BIT_PERF_EVENTS)
122 #define TICK_DEP_MASK_SCHED (1 << TICK_DEP_BIT_SCHED)
123 #define TICK_DEP_MASK_CLOCK_UNSTABLE (1 << TICK_DEP_BIT_CLOCK_UNSTABLE)
124 #define TICK_DEP_MASK_RCU (1 << TICK_DEP_BIT_RCU)
125 #define TICK_DEP_MASK_RCU_EXP (1 << TICK_DEP_BIT_RCU_EXP)
126
127 #ifdef CONFIG_NO_HZ_COMMON
128 extern bool tick_nohz_enabled;
129 extern bool tick_nohz_tick_stopped(void);
130 extern bool tick_nohz_tick_stopped_cpu(int cpu);
131 extern void tick_nohz_idle_stop_tick(void);
132 extern void tick_nohz_idle_retain_tick(void);
133 extern void tick_nohz_idle_restart_tick(void);
134 extern void tick_nohz_idle_enter(void);
135 extern void tick_nohz_idle_exit(void);
136 extern void tick_nohz_irq_exit(void);
137 extern bool tick_nohz_idle_got_tick(void);
138 extern ktime_t tick_nohz_get_next_hrtimer(void);
139 extern ktime_t tick_nohz_get_sleep_length(ktime_t *delta_next);
140 extern unsigned long tick_nohz_get_idle_calls_cpu(int cpu);
141 extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time);
142 extern u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time);
143 #else /* !CONFIG_NO_HZ_COMMON */
144 #define tick_nohz_enabled (0)
tick_nohz_tick_stopped(void)145 static inline int tick_nohz_tick_stopped(void) { return 0; }
tick_nohz_tick_stopped_cpu(int cpu)146 static inline int tick_nohz_tick_stopped_cpu(int cpu) { return 0; }
tick_nohz_idle_stop_tick(void)147 static inline void tick_nohz_idle_stop_tick(void) { }
tick_nohz_idle_retain_tick(void)148 static inline void tick_nohz_idle_retain_tick(void) { }
tick_nohz_idle_restart_tick(void)149 static inline void tick_nohz_idle_restart_tick(void) { }
tick_nohz_idle_enter(void)150 static inline void tick_nohz_idle_enter(void) { }
tick_nohz_idle_exit(void)151 static inline void tick_nohz_idle_exit(void) { }
tick_nohz_idle_got_tick(void)152 static inline bool tick_nohz_idle_got_tick(void) { return false; }
tick_nohz_get_next_hrtimer(void)153 static inline ktime_t tick_nohz_get_next_hrtimer(void)
154 {
155 /* Next wake up is the tick period, assume it starts now */
156 return ktime_add(ktime_get(), TICK_NSEC);
157 }
tick_nohz_get_sleep_length(ktime_t * delta_next)158 static inline ktime_t tick_nohz_get_sleep_length(ktime_t *delta_next)
159 {
160 *delta_next = TICK_NSEC;
161 return *delta_next;
162 }
get_cpu_idle_time_us(int cpu,u64 * unused)163 static inline u64 get_cpu_idle_time_us(int cpu, u64 *unused) { return -1; }
get_cpu_iowait_time_us(int cpu,u64 * unused)164 static inline u64 get_cpu_iowait_time_us(int cpu, u64 *unused) { return -1; }
165 #endif /* !CONFIG_NO_HZ_COMMON */
166
167 /*
168 * Mask of CPUs that are nohz_full.
169 *
170 * Users should be guarded by CONFIG_NO_HZ_FULL or a tick_nohz_full_cpu()
171 * check.
172 */
173 extern cpumask_var_t tick_nohz_full_mask;
174
175 #ifdef CONFIG_NO_HZ_FULL
176 extern bool tick_nohz_full_running;
177
tick_nohz_full_enabled(void)178 static inline bool tick_nohz_full_enabled(void)
179 {
180 if (!context_tracking_enabled())
181 return false;
182
183 return tick_nohz_full_running;
184 }
185
186 /*
187 * Check if a CPU is part of the nohz_full subset. Arrange for evaluating
188 * the cpu expression (typically smp_processor_id()) _after_ the static
189 * key.
190 */
191 #define tick_nohz_full_cpu(_cpu) ({ \
192 bool __ret = false; \
193 if (tick_nohz_full_enabled()) \
194 __ret = cpumask_test_cpu((_cpu), tick_nohz_full_mask); \
195 __ret; \
196 })
197
198 extern void tick_nohz_dep_set(enum tick_dep_bits bit);
199 extern void tick_nohz_dep_clear(enum tick_dep_bits bit);
200 extern void tick_nohz_dep_set_cpu(int cpu, enum tick_dep_bits bit);
201 extern void tick_nohz_dep_clear_cpu(int cpu, enum tick_dep_bits bit);
202 extern void tick_nohz_dep_set_task(struct task_struct *tsk,
203 enum tick_dep_bits bit);
204 extern void tick_nohz_dep_clear_task(struct task_struct *tsk,
205 enum tick_dep_bits bit);
206 extern void tick_nohz_dep_set_signal(struct task_struct *tsk,
207 enum tick_dep_bits bit);
208 extern void tick_nohz_dep_clear_signal(struct signal_struct *signal,
209 enum tick_dep_bits bit);
210 extern bool tick_nohz_cpu_hotpluggable(unsigned int cpu);
211
212 /*
213 * The below are tick_nohz_[set,clear]_dep() wrappers that optimize off-cases
214 * on top of static keys.
215 */
tick_dep_set(enum tick_dep_bits bit)216 static inline void tick_dep_set(enum tick_dep_bits bit)
217 {
218 if (tick_nohz_full_enabled())
219 tick_nohz_dep_set(bit);
220 }
221
tick_dep_clear(enum tick_dep_bits bit)222 static inline void tick_dep_clear(enum tick_dep_bits bit)
223 {
224 if (tick_nohz_full_enabled())
225 tick_nohz_dep_clear(bit);
226 }
227
tick_dep_set_cpu(int cpu,enum tick_dep_bits bit)228 static inline void tick_dep_set_cpu(int cpu, enum tick_dep_bits bit)
229 {
230 if (tick_nohz_full_cpu(cpu))
231 tick_nohz_dep_set_cpu(cpu, bit);
232 }
233
tick_dep_clear_cpu(int cpu,enum tick_dep_bits bit)234 static inline void tick_dep_clear_cpu(int cpu, enum tick_dep_bits bit)
235 {
236 if (tick_nohz_full_cpu(cpu))
237 tick_nohz_dep_clear_cpu(cpu, bit);
238 }
239
tick_dep_set_task(struct task_struct * tsk,enum tick_dep_bits bit)240 static inline void tick_dep_set_task(struct task_struct *tsk,
241 enum tick_dep_bits bit)
242 {
243 if (tick_nohz_full_enabled())
244 tick_nohz_dep_set_task(tsk, bit);
245 }
246
tick_dep_clear_task(struct task_struct * tsk,enum tick_dep_bits bit)247 static inline void tick_dep_clear_task(struct task_struct *tsk,
248 enum tick_dep_bits bit)
249 {
250 if (tick_nohz_full_enabled())
251 tick_nohz_dep_clear_task(tsk, bit);
252 }
253
tick_dep_init_task(struct task_struct * tsk)254 static inline void tick_dep_init_task(struct task_struct *tsk)
255 {
256 atomic_set(&tsk->tick_dep_mask, 0);
257 }
258
tick_dep_set_signal(struct task_struct * tsk,enum tick_dep_bits bit)259 static inline void tick_dep_set_signal(struct task_struct *tsk,
260 enum tick_dep_bits bit)
261 {
262 if (tick_nohz_full_enabled())
263 tick_nohz_dep_set_signal(tsk, bit);
264 }
tick_dep_clear_signal(struct signal_struct * signal,enum tick_dep_bits bit)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
tick_nohz_full_enabled(void)276 static inline bool tick_nohz_full_enabled(void) { return false; }
tick_nohz_full_cpu(int cpu)277 static inline bool tick_nohz_full_cpu(int cpu) { return false; }
278
tick_nohz_dep_set_cpu(int cpu,enum tick_dep_bits bit)279 static inline void tick_nohz_dep_set_cpu(int cpu, enum tick_dep_bits bit) { }
tick_nohz_dep_clear_cpu(int cpu,enum tick_dep_bits bit)280 static inline void tick_nohz_dep_clear_cpu(int cpu, enum tick_dep_bits bit) { }
tick_nohz_cpu_hotpluggable(unsigned int cpu)281 static inline bool tick_nohz_cpu_hotpluggable(unsigned int cpu) { return true; }
282
tick_dep_set(enum tick_dep_bits bit)283 static inline void tick_dep_set(enum tick_dep_bits bit) { }
tick_dep_clear(enum tick_dep_bits bit)284 static inline void tick_dep_clear(enum tick_dep_bits bit) { }
tick_dep_set_cpu(int cpu,enum tick_dep_bits bit)285 static inline void tick_dep_set_cpu(int cpu, enum tick_dep_bits bit) { }
tick_dep_clear_cpu(int cpu,enum tick_dep_bits bit)286 static inline void tick_dep_clear_cpu(int cpu, enum tick_dep_bits bit) { }
tick_dep_set_task(struct task_struct * tsk,enum tick_dep_bits bit)287 static inline void tick_dep_set_task(struct task_struct *tsk,
288 enum tick_dep_bits bit) { }
tick_dep_clear_task(struct task_struct * tsk,enum tick_dep_bits bit)289 static inline void tick_dep_clear_task(struct task_struct *tsk,
290 enum tick_dep_bits bit) { }
tick_dep_init_task(struct task_struct * tsk)291 static inline void tick_dep_init_task(struct task_struct *tsk) { }
tick_dep_set_signal(struct task_struct * tsk,enum tick_dep_bits bit)292 static inline void tick_dep_set_signal(struct task_struct *tsk,
293 enum tick_dep_bits bit) { }
tick_dep_clear_signal(struct signal_struct * signal,enum tick_dep_bits bit)294 static inline void tick_dep_clear_signal(struct signal_struct *signal,
295 enum tick_dep_bits bit) { }
296
tick_nohz_full_kick_cpu(int cpu)297 static inline void tick_nohz_full_kick_cpu(int cpu) { }
__tick_nohz_task_switch(void)298 static inline void __tick_nohz_task_switch(void) { }
tick_nohz_full_setup(cpumask_var_t cpumask)299 static inline void tick_nohz_full_setup(cpumask_var_t cpumask) { }
300 #endif
301
tick_nohz_task_switch(void)302 static inline void tick_nohz_task_switch(void)
303 {
304 if (tick_nohz_full_enabled())
305 __tick_nohz_task_switch();
306 }
307
tick_nohz_user_enter_prepare(void)308 static inline void tick_nohz_user_enter_prepare(void)
309 {
310 if (tick_nohz_full_cpu(smp_processor_id()))
311 rcu_nocb_flush_deferred_wakeup();
312 }
313
314 #endif
315