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 extern void tick_cleanup_dead_cpu(int cpu);
24 #else /* CONFIG_GENERIC_CLOCKEVENTS */
25 static inline void tick_init(void) { }
26 static inline void tick_suspend_local(void) { }
27 static inline void tick_resume_local(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_HOTPLUG_CPU)
32 extern int tick_cpu_dying(unsigned int cpu);
33 extern void tick_assert_timekeeping_handover(void);
34 #else
35 #define tick_cpu_dying NULL
36 static inline void tick_assert_timekeeping_handover(void) { }
37 #endif
38
39 #if defined(CONFIG_GENERIC_CLOCKEVENTS) && defined(CONFIG_SUSPEND)
40 extern void tick_freeze(void);
41 extern void tick_unfreeze(void);
42 #else
43 static inline void tick_freeze(void) { }
44 static inline void tick_unfreeze(void) { }
45 #endif
46
47 #ifdef CONFIG_TICK_ONESHOT
48 extern void tick_irq_enter(void);
49 # ifndef arch_needs_cpu
50 # define arch_needs_cpu() (0)
51 # endif
52 # else
53 static inline void tick_irq_enter(void) { }
54 #endif
55
56 #if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT)
57 extern void hotplug_cpu__broadcast_tick_pull(int dead_cpu);
58 #else
59 static inline void hotplug_cpu__broadcast_tick_pull(int dead_cpu) { }
60 #endif
61
62 enum tick_broadcast_mode {
63 TICK_BROADCAST_OFF,
64 TICK_BROADCAST_ON,
65 TICK_BROADCAST_FORCE,
66 };
67
68 enum tick_broadcast_state {
69 TICK_BROADCAST_EXIT,
70 TICK_BROADCAST_ENTER,
71 };
72
73 extern struct static_key_false arch_needs_tick_broadcast;
74
75 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
76 extern void tick_broadcast_control(enum tick_broadcast_mode mode);
77 #else
78 static inline void tick_broadcast_control(enum tick_broadcast_mode mode) { }
79 #endif /* BROADCAST */
80
81 #ifdef CONFIG_GENERIC_CLOCKEVENTS
82 extern int tick_broadcast_oneshot_control(enum tick_broadcast_state state);
83 #else
84 static inline int tick_broadcast_oneshot_control(enum tick_broadcast_state state)
85 {
86 return 0;
87 }
88 #endif
89
90 static inline void tick_broadcast_enable(void)
91 {
92 tick_broadcast_control(TICK_BROADCAST_ON);
93 }
94 static inline void tick_broadcast_disable(void)
95 {
96 tick_broadcast_control(TICK_BROADCAST_OFF);
97 }
98 static inline void tick_broadcast_force(void)
99 {
100 tick_broadcast_control(TICK_BROADCAST_FORCE);
101 }
102 static inline int tick_broadcast_enter(void)
103 {
104 return tick_broadcast_oneshot_control(TICK_BROADCAST_ENTER);
105 }
106 static inline void tick_broadcast_exit(void)
107 {
108 tick_broadcast_oneshot_control(TICK_BROADCAST_EXIT);
109 }
110
111 enum 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
130 extern bool tick_nohz_enabled;
131 extern bool tick_nohz_tick_stopped(void);
132 extern bool tick_nohz_tick_stopped_cpu(int cpu);
133 extern void tick_nohz_idle_stop_tick(void);
134 extern void tick_nohz_idle_retain_tick(void);
135 extern void tick_nohz_idle_restart_tick(void);
136 extern void tick_nohz_idle_enter(void);
137 extern void tick_nohz_idle_exit(void);
138 extern void tick_nohz_irq_exit(void);
139 extern bool tick_nohz_idle_got_tick(void);
140 extern ktime_t tick_nohz_get_next_hrtimer(void);
141 extern ktime_t tick_nohz_get_sleep_length(ktime_t *delta_next);
142 extern unsigned long tick_nohz_get_idle_calls_cpu(int cpu);
143 extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time);
144 extern u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time);
145 #else /* !CONFIG_NO_HZ_COMMON */
146 #define tick_nohz_enabled (0)
147 static inline int tick_nohz_tick_stopped(void) { return 0; }
148 static inline int tick_nohz_tick_stopped_cpu(int cpu) { return 0; }
149 static inline void tick_nohz_idle_stop_tick(void) { }
150 static inline void tick_nohz_idle_retain_tick(void) { }
151 static inline void tick_nohz_idle_restart_tick(void) { }
152 static inline void tick_nohz_idle_enter(void) { }
153 static inline void tick_nohz_idle_exit(void) { }
154 static inline bool tick_nohz_idle_got_tick(void) { return false; }
155 static 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 }
160 static inline ktime_t tick_nohz_get_sleep_length(ktime_t *delta_next)
161 {
162 *delta_next = TICK_NSEC;
163 return *delta_next;
164 }
165 static inline u64 get_cpu_idle_time_us(int cpu, u64 *unused) { return -1; }
166 static 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 */
175 extern cpumask_var_t tick_nohz_full_mask;
176
177 #ifdef CONFIG_NO_HZ_FULL
178 extern bool tick_nohz_full_running;
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 task_struct *tsk,
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 extern 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 */
224 static 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
230 static 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
236 static 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
242 static 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
248 static 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 }
254 static 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 }
260 static 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 }
266 static 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
273 extern void tick_nohz_full_kick_cpu(int cpu);
274 extern void __tick_nohz_task_switch(void);
275 extern void __init tick_nohz_full_setup(cpumask_var_t cpumask);
276 #else
277 static inline bool tick_nohz_full_enabled(void) { return false; }
278 static inline bool tick_nohz_full_cpu(int cpu) { return false; }
279 static inline void tick_nohz_full_add_cpus_to(struct cpumask *mask) { }
280
281 static inline void tick_nohz_dep_set_cpu(int cpu, enum tick_dep_bits bit) { }
282 static inline void tick_nohz_dep_clear_cpu(int cpu, enum tick_dep_bits bit) { }
283 static inline bool tick_nohz_cpu_hotpluggable(unsigned int cpu) { return true; }
284
285 static inline void tick_dep_set(enum tick_dep_bits bit) { }
286 static inline void tick_dep_clear(enum tick_dep_bits bit) { }
287 static inline void tick_dep_set_cpu(int cpu, enum tick_dep_bits bit) { }
288 static inline void tick_dep_clear_cpu(int cpu, enum tick_dep_bits bit) { }
289 static inline void tick_dep_set_task(struct task_struct *tsk,
290 enum tick_dep_bits bit) { }
291 static inline void tick_dep_clear_task(struct task_struct *tsk,
292 enum tick_dep_bits bit) { }
293 static inline void tick_dep_set_signal(struct task_struct *tsk,
294 enum tick_dep_bits bit) { }
295 static inline void tick_dep_clear_signal(struct signal_struct *signal,
296 enum tick_dep_bits bit) { }
297
298 static inline void tick_nohz_full_kick_cpu(int cpu) { }
299 static inline void __tick_nohz_task_switch(void) { }
300 static inline void tick_nohz_full_setup(cpumask_var_t cpumask) { }
301 #endif
302
303 static inline void tick_nohz_task_switch(void)
304 {
305 if (tick_nohz_full_enabled())
306 __tick_nohz_task_switch();
307 }
308
309 static 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
316
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