linux/include/linux/tick.h
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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
  15#ifdef CONFIG_GENERIC_CLOCKEVENTS
  16extern void __init tick_init(void);
  17/* Should be core only, but ARM BL switcher requires it */
  18extern void tick_suspend_local(void);
  19/* Should be core only, but XEN resume magic and ARM BL switcher require it */
  20extern void tick_resume_local(void);
  21extern void tick_handover_do_timer(void);
  22extern void tick_cleanup_dead_cpu(int cpu);
  23#else /* CONFIG_GENERIC_CLOCKEVENTS */
  24static inline void tick_init(void) { }
  25static inline void tick_suspend_local(void) { }
  26static inline void tick_resume_local(void) { }
  27static inline void tick_handover_do_timer(void) { }
  28static inline void tick_cleanup_dead_cpu(int cpu) { }
  29#endif /* !CONFIG_GENERIC_CLOCKEVENTS */
  30
  31#if defined(CONFIG_GENERIC_CLOCKEVENTS) && defined(CONFIG_SUSPEND)
  32extern void tick_freeze(void);
  33extern void tick_unfreeze(void);
  34#else
  35static inline void tick_freeze(void) { }
  36static inline void tick_unfreeze(void) { }
  37#endif
  38
  39#ifdef CONFIG_TICK_ONESHOT
  40extern void tick_irq_enter(void);
  41#  ifndef arch_needs_cpu
  42#   define arch_needs_cpu() (0)
  43#  endif
  44# else
  45static inline void tick_irq_enter(void) { }
  46#endif
  47
  48#if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT)
  49extern void hotplug_cpu__broadcast_tick_pull(int dead_cpu);
  50#else
  51static inline void hotplug_cpu__broadcast_tick_pull(int dead_cpu) { }
  52#endif
  53
  54enum tick_broadcast_mode {
  55        TICK_BROADCAST_OFF,
  56        TICK_BROADCAST_ON,
  57        TICK_BROADCAST_FORCE,
  58};
  59
  60enum tick_broadcast_state {
  61        TICK_BROADCAST_EXIT,
  62        TICK_BROADCAST_ENTER,
  63};
  64
  65#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
  66extern void tick_broadcast_control(enum tick_broadcast_mode mode);
  67#else
  68static 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)
  72extern void tick_offline_cpu(unsigned int cpu);
  73#else
  74static inline void tick_offline_cpu(unsigned int cpu) { }
  75#endif
  76
  77#ifdef CONFIG_GENERIC_CLOCKEVENTS
  78extern int tick_broadcast_oneshot_control(enum tick_broadcast_state state);
  79#else
  80static inline int tick_broadcast_oneshot_control(enum tick_broadcast_state state)
  81{
  82        return 0;
  83}
  84#endif
  85
  86static inline void tick_broadcast_enable(void)
  87{
  88        tick_broadcast_control(TICK_BROADCAST_ON);
  89}
  90static inline void tick_broadcast_disable(void)
  91{
  92        tick_broadcast_control(TICK_BROADCAST_OFF);
  93}
  94static inline void tick_broadcast_force(void)
  95{
  96        tick_broadcast_control(TICK_BROADCAST_FORCE);
  97}
  98static inline int tick_broadcast_enter(void)
  99{
 100        return tick_broadcast_oneshot_control(TICK_BROADCAST_ENTER);
 101}
 102static inline void tick_broadcast_exit(void)
 103{
 104        tick_broadcast_oneshot_control(TICK_BROADCAST_EXIT);
 105}
 106
 107enum 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
 126extern bool tick_nohz_enabled;
 127extern bool tick_nohz_tick_stopped(void);
 128extern bool tick_nohz_tick_stopped_cpu(int cpu);
 129extern void tick_nohz_idle_stop_tick(void);
 130extern void tick_nohz_idle_retain_tick(void);
 131extern void tick_nohz_idle_restart_tick(void);
 132extern void tick_nohz_idle_enter(void);
 133extern void tick_nohz_idle_exit(void);
 134extern void tick_nohz_irq_exit(void);
 135extern bool tick_nohz_idle_got_tick(void);
 136extern ktime_t tick_nohz_get_next_hrtimer(void);
 137extern ktime_t tick_nohz_get_sleep_length(ktime_t *delta_next);
 138extern unsigned long tick_nohz_get_idle_calls(void);
 139extern unsigned long tick_nohz_get_idle_calls_cpu(int cpu);
 140extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time);
 141extern u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time);
 142
 143static 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)
 152static inline int tick_nohz_tick_stopped(void) { return 0; }
 153static inline int tick_nohz_tick_stopped_cpu(int cpu) { return 0; }
 154static inline void tick_nohz_idle_stop_tick(void) { }
 155static inline void tick_nohz_idle_retain_tick(void) { }
 156static inline void tick_nohz_idle_restart_tick(void) { }
 157static inline void tick_nohz_idle_enter(void) { }
 158static inline void tick_nohz_idle_exit(void) { }
 159static inline bool tick_nohz_idle_got_tick(void) { return false; }
 160static 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}
 165static inline ktime_t tick_nohz_get_sleep_length(ktime_t *delta_next)
 166{
 167        *delta_next = TICK_NSEC;
 168        return *delta_next;
 169}
 170static inline u64 get_cpu_idle_time_us(int cpu, u64 *unused) { return -1; }
 171static inline u64 get_cpu_iowait_time_us(int cpu, u64 *unused) { return -1; }
 172
 173static inline void tick_nohz_idle_stop_tick_protected(void) { }
 174#endif /* !CONFIG_NO_HZ_COMMON */
 175
 176#ifdef CONFIG_NO_HZ_FULL
 177extern bool tick_nohz_full_running;
 178extern cpumask_var_t tick_nohz_full_mask;
 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
 188static inline bool tick_nohz_full_cpu(int cpu)
 189{
 190        if (!tick_nohz_full_enabled())
 191                return false;
 192
 193        return cpumask_test_cpu(cpu, tick_nohz_full_mask);
 194}
 195
 196static inline void tick_nohz_full_add_cpus_to(struct cpumask *mask)
 197{
 198        if (tick_nohz_full_enabled())
 199                cpumask_or(mask, mask, tick_nohz_full_mask);
 200}
 201
 202extern void tick_nohz_dep_set(enum tick_dep_bits bit);
 203extern void tick_nohz_dep_clear(enum tick_dep_bits bit);
 204extern void tick_nohz_dep_set_cpu(int cpu, enum tick_dep_bits bit);
 205extern void tick_nohz_dep_clear_cpu(int cpu, enum tick_dep_bits bit);
 206extern void tick_nohz_dep_set_task(struct task_struct *tsk,
 207                                   enum tick_dep_bits bit);
 208extern void tick_nohz_dep_clear_task(struct task_struct *tsk,
 209                                     enum tick_dep_bits bit);
 210extern void tick_nohz_dep_set_signal(struct signal_struct *signal,
 211                                     enum tick_dep_bits bit);
 212extern void tick_nohz_dep_clear_signal(struct signal_struct *signal,
 213                                       enum tick_dep_bits bit);
 214
 215/*
 216 * The below are tick_nohz_[set,clear]_dep() wrappers that optimize off-cases
 217 * on top of static keys.
 218 */
 219static inline void tick_dep_set(enum tick_dep_bits bit)
 220{
 221        if (tick_nohz_full_enabled())
 222                tick_nohz_dep_set(bit);
 223}
 224
 225static inline void tick_dep_clear(enum tick_dep_bits bit)
 226{
 227        if (tick_nohz_full_enabled())
 228                tick_nohz_dep_clear(bit);
 229}
 230
 231static inline void tick_dep_set_cpu(int cpu, enum tick_dep_bits bit)
 232{
 233        if (tick_nohz_full_cpu(cpu))
 234                tick_nohz_dep_set_cpu(cpu, bit);
 235}
 236
 237static inline void tick_dep_clear_cpu(int cpu, enum tick_dep_bits bit)
 238{
 239        if (tick_nohz_full_cpu(cpu))
 240                tick_nohz_dep_clear_cpu(cpu, bit);
 241}
 242
 243static inline void tick_dep_set_task(struct task_struct *tsk,
 244                                     enum tick_dep_bits bit)
 245{
 246        if (tick_nohz_full_enabled())
 247                tick_nohz_dep_set_task(tsk, bit);
 248}
 249static inline void tick_dep_clear_task(struct task_struct *tsk,
 250                                       enum tick_dep_bits bit)
 251{
 252        if (tick_nohz_full_enabled())
 253                tick_nohz_dep_clear_task(tsk, bit);
 254}
 255static inline void tick_dep_set_signal(struct signal_struct *signal,
 256                                       enum tick_dep_bits bit)
 257{
 258        if (tick_nohz_full_enabled())
 259                tick_nohz_dep_set_signal(signal, bit);
 260}
 261static inline void tick_dep_clear_signal(struct signal_struct *signal,
 262                                         enum tick_dep_bits bit)
 263{
 264        if (tick_nohz_full_enabled())
 265                tick_nohz_dep_clear_signal(signal, bit);
 266}
 267
 268extern void tick_nohz_full_kick_cpu(int cpu);
 269extern void __tick_nohz_task_switch(void);
 270extern void __init tick_nohz_full_setup(cpumask_var_t cpumask);
 271#else
 272static inline bool tick_nohz_full_enabled(void) { return false; }
 273static inline bool tick_nohz_full_cpu(int cpu) { return false; }
 274static inline void tick_nohz_full_add_cpus_to(struct cpumask *mask) { }
 275
 276static inline void tick_nohz_dep_set_cpu(int cpu, enum tick_dep_bits bit) { }
 277static inline void tick_nohz_dep_clear_cpu(int cpu, enum tick_dep_bits bit) { }
 278
 279static inline void tick_dep_set(enum tick_dep_bits bit) { }
 280static inline void tick_dep_clear(enum tick_dep_bits bit) { }
 281static inline void tick_dep_set_cpu(int cpu, enum tick_dep_bits bit) { }
 282static inline void tick_dep_clear_cpu(int cpu, enum tick_dep_bits bit) { }
 283static inline void tick_dep_set_task(struct task_struct *tsk,
 284                                     enum tick_dep_bits bit) { }
 285static inline void tick_dep_clear_task(struct task_struct *tsk,
 286                                       enum tick_dep_bits bit) { }
 287static inline void tick_dep_set_signal(struct signal_struct *signal,
 288                                       enum tick_dep_bits bit) { }
 289static inline void tick_dep_clear_signal(struct signal_struct *signal,
 290                                         enum tick_dep_bits bit) { }
 291
 292static inline void tick_nohz_full_kick_cpu(int cpu) { }
 293static inline void __tick_nohz_task_switch(void) { }
 294static inline void tick_nohz_full_setup(cpumask_var_t cpumask) { }
 295#endif
 296
 297static inline void tick_nohz_task_switch(void)
 298{
 299        if (tick_nohz_full_enabled())
 300                __tick_nohz_task_switch();
 301}
 302
 303#endif
 304