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(void); 143extern unsigned long tick_nohz_get_idle_calls_cpu(int cpu); 144extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time); 145extern u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time); 146#else /* !CONFIG_NO_HZ_COMMON */ 147#define tick_nohz_enabled (0) 148static inline int tick_nohz_tick_stopped(void) { return 0; } 149static inline int tick_nohz_tick_stopped_cpu(int cpu) { return 0; } 150static inline void tick_nohz_idle_stop_tick(void) { } 151static inline void tick_nohz_idle_retain_tick(void) { } 152static inline void tick_nohz_idle_restart_tick(void) { } 153static inline void tick_nohz_idle_enter(void) { } 154static inline void tick_nohz_idle_exit(void) { } 155static inline bool tick_nohz_idle_got_tick(void) { return false; } 156static inline ktime_t tick_nohz_get_next_hrtimer(void) 157{ 158 /* Next wake up is the tick period, assume it starts now */ 159 return ktime_add(ktime_get(), TICK_NSEC); 160} 161static inline ktime_t tick_nohz_get_sleep_length(ktime_t *delta_next) 162{ 163 *delta_next = TICK_NSEC; 164 return *delta_next; 165} 166static inline u64 get_cpu_idle_time_us(int cpu, u64 *unused) { return -1; } 167static inline u64 get_cpu_iowait_time_us(int cpu, u64 *unused) { return -1; } 168#endif /* !CONFIG_NO_HZ_COMMON */ 169 170/* 171 * Mask of CPUs that are nohz_full. 172 * 173 * Users should be guarded by CONFIG_NO_HZ_FULL or a tick_nohz_full_cpu() 174 * check. 175 */ 176extern cpumask_var_t tick_nohz_full_mask; 177 178#ifdef CONFIG_NO_HZ_FULL 179extern bool tick_nohz_full_running; 180 181static inline bool tick_nohz_full_enabled(void) 182{ 183 if (!context_tracking_enabled()) 184 return false; 185 186 return tick_nohz_full_running; 187} 188 189/* 190 * Check if a CPU is part of the nohz_full subset. Arrange for evaluating 191 * the cpu expression (typically smp_processor_id()) _after_ the static 192 * key. 193 */ 194#define tick_nohz_full_cpu(_cpu) ({ \ 195 bool __ret = false; \ 196 if (tick_nohz_full_enabled()) \ 197 __ret = cpumask_test_cpu((_cpu), tick_nohz_full_mask); \ 198 __ret; \ 199}) 200 201static inline void tick_nohz_full_add_cpus_to(struct cpumask *mask) 202{ 203 if (tick_nohz_full_enabled()) 204 cpumask_or(mask, mask, tick_nohz_full_mask); 205} 206 207extern void tick_nohz_dep_set(enum tick_dep_bits bit); 208extern void tick_nohz_dep_clear(enum tick_dep_bits bit); 209extern void tick_nohz_dep_set_cpu(int cpu, enum tick_dep_bits bit); 210extern void tick_nohz_dep_clear_cpu(int cpu, enum tick_dep_bits bit); 211extern void tick_nohz_dep_set_task(struct task_struct *tsk, 212 enum tick_dep_bits bit); 213extern void tick_nohz_dep_clear_task(struct task_struct *tsk, 214 enum tick_dep_bits bit); 215extern void tick_nohz_dep_set_signal(struct task_struct *tsk, 216 enum tick_dep_bits bit); 217extern void tick_nohz_dep_clear_signal(struct signal_struct *signal, 218 enum tick_dep_bits bit); 219extern bool tick_nohz_cpu_hotpluggable(unsigned int cpu); 220 221/* 222 * The below are tick_nohz_[set,clear]_dep() wrappers that optimize off-cases 223 * on top of static keys. 224 */ 225static inline void tick_dep_set(enum tick_dep_bits bit) 226{ 227 if (tick_nohz_full_enabled()) 228 tick_nohz_dep_set(bit); 229} 230 231static inline void tick_dep_clear(enum tick_dep_bits bit) 232{ 233 if (tick_nohz_full_enabled()) 234 tick_nohz_dep_clear(bit); 235} 236 237static inline void tick_dep_set_cpu(int cpu, enum tick_dep_bits bit) 238{ 239 if (tick_nohz_full_cpu(cpu)) 240 tick_nohz_dep_set_cpu(cpu, bit); 241} 242 243static inline void tick_dep_clear_cpu(int cpu, enum tick_dep_bits bit) 244{ 245 if (tick_nohz_full_cpu(cpu)) 246 tick_nohz_dep_clear_cpu(cpu, bit); 247} 248 249static inline void tick_dep_set_task(struct task_struct *tsk, 250 enum tick_dep_bits bit) 251{ 252 if (tick_nohz_full_enabled()) 253 tick_nohz_dep_set_task(tsk, bit); 254} 255static inline void tick_dep_clear_task(struct task_struct *tsk, 256 enum tick_dep_bits bit) 257{ 258 if (tick_nohz_full_enabled()) 259 tick_nohz_dep_clear_task(tsk, bit); 260} 261static inline void tick_dep_set_signal(struct task_struct *tsk, 262 enum tick_dep_bits bit) 263{ 264 if (tick_nohz_full_enabled()) 265 tick_nohz_dep_set_signal(tsk, bit); 266} 267static inline void tick_dep_clear_signal(struct signal_struct *signal, 268 enum tick_dep_bits bit) 269{ 270 if (tick_nohz_full_enabled()) 271 tick_nohz_dep_clear_signal(signal, bit); 272} 273 274extern void tick_nohz_full_kick_cpu(int cpu); 275extern void __tick_nohz_task_switch(void); 276extern void __init tick_nohz_full_setup(cpumask_var_t cpumask); 277#else 278static inline bool tick_nohz_full_enabled(void) { return false; } 279static inline bool tick_nohz_full_cpu(int cpu) { return false; } 280static inline void tick_nohz_full_add_cpus_to(struct cpumask *mask) { } 281 282static inline void tick_nohz_dep_set_cpu(int cpu, enum tick_dep_bits bit) { } 283static inline void tick_nohz_dep_clear_cpu(int cpu, enum tick_dep_bits bit) { } 284static inline bool tick_nohz_cpu_hotpluggable(unsigned int cpu) { return true; } 285 286static inline void tick_dep_set(enum tick_dep_bits bit) { } 287static inline void tick_dep_clear(enum tick_dep_bits bit) { } 288static inline void tick_dep_set_cpu(int cpu, enum tick_dep_bits bit) { } 289static inline void tick_dep_clear_cpu(int cpu, enum tick_dep_bits bit) { } 290static inline void tick_dep_set_task(struct task_struct *tsk, 291 enum tick_dep_bits bit) { } 292static inline void tick_dep_clear_task(struct task_struct *tsk, 293 enum tick_dep_bits bit) { } 294static inline void tick_dep_set_signal(struct task_struct *tsk, 295 enum tick_dep_bits bit) { } 296static inline void tick_dep_clear_signal(struct signal_struct *signal, 297 enum tick_dep_bits bit) { } 298 299static inline void tick_nohz_full_kick_cpu(int cpu) { } 300static inline void __tick_nohz_task_switch(void) { } 301static inline void tick_nohz_full_setup(cpumask_var_t cpumask) { } 302#endif 303 304static inline void tick_nohz_task_switch(void) 305{ 306 if (tick_nohz_full_enabled()) 307 __tick_nohz_task_switch(); 308} 309 310static inline void tick_nohz_user_enter_prepare(void) 311{ 312 if (tick_nohz_full_cpu(smp_processor_id())) 313 rcu_nocb_flush_deferred_wakeup(); 314} 315 316#endif 317