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#include <linux/rcupdate.h>
  15
  16#ifdef CONFIG_GENERIC_CLOCKEVENTS
  17extern void __init tick_init(void);
  18/* Should be core only, but ARM BL switcher requires it */
  19extern void tick_suspend_local(void);
  20/* Should be core only, but XEN resume magic and ARM BL switcher require it */
  21extern void tick_resume_local(void);
  22extern void tick_handover_do_timer(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_handover_do_timer(void) { }
  29static inline void tick_cleanup_dead_cpu(int cpu) { }
  30#endif /* !CONFIG_GENERIC_CLOCKEVENTS */
  31
  32#if defined(CONFIG_GENERIC_CLOCKEVENTS) && defined(CONFIG_SUSPEND)
  33extern void tick_freeze(void);
  34extern void tick_unfreeze(void);
  35#else
  36static inline void tick_freeze(void) { }
  37static inline void tick_unfreeze(void) { }
  38#endif
  39
  40#ifdef CONFIG_TICK_ONESHOT
  41extern void tick_irq_enter(void);
  42#  ifndef arch_needs_cpu
  43#   define arch_needs_cpu() (0)
  44#  endif
  45# else
  46static inline void tick_irq_enter(void) { }
  47#endif
  48
  49#if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT)
  50extern void hotplug_cpu__broadcast_tick_pull(int dead_cpu);
  51#else
  52static inline void hotplug_cpu__broadcast_tick_pull(int dead_cpu) { }
  53#endif
  54
  55enum tick_broadcast_mode {
  56        TICK_BROADCAST_OFF,
  57        TICK_BROADCAST_ON,
  58        TICK_BROADCAST_FORCE,
  59};
  60
  61enum tick_broadcast_state {
  62        TICK_BROADCAST_EXIT,
  63        TICK_BROADCAST_ENTER,
  64};
  65
  66#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
  67extern void tick_broadcast_control(enum tick_broadcast_mode mode);
  68#else
  69static inline void tick_broadcast_control(enum tick_broadcast_mode mode) { }
  70#endif /* BROADCAST */
  71
  72#if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_HOTPLUG_CPU)
  73extern void tick_offline_cpu(unsigned int cpu);
  74#else
  75static inline void tick_offline_cpu(unsigned int cpu) { }
  76#endif
  77
  78#ifdef CONFIG_GENERIC_CLOCKEVENTS
  79extern int tick_broadcast_oneshot_control(enum tick_broadcast_state state);
  80#else
  81static inline int tick_broadcast_oneshot_control(enum tick_broadcast_state state)
  82{
  83        return 0;
  84}
  85#endif
  86
  87static inline void tick_broadcast_enable(void)
  88{
  89        tick_broadcast_control(TICK_BROADCAST_ON);
  90}
  91static inline void tick_broadcast_disable(void)
  92{
  93        tick_broadcast_control(TICK_BROADCAST_OFF);
  94}
  95static inline void tick_broadcast_force(void)
  96{
  97        tick_broadcast_control(TICK_BROADCAST_FORCE);
  98}
  99static inline int tick_broadcast_enter(void)
 100{
 101        return tick_broadcast_oneshot_control(TICK_BROADCAST_ENTER);
 102}
 103static inline void tick_broadcast_exit(void)
 104{
 105        tick_broadcast_oneshot_control(TICK_BROADCAST_EXIT);
 106}
 107
 108enum tick_dep_bits {
 109        TICK_DEP_BIT_POSIX_TIMER        = 0,
 110        TICK_DEP_BIT_PERF_EVENTS        = 1,
 111        TICK_DEP_BIT_SCHED              = 2,
 112        TICK_DEP_BIT_CLOCK_UNSTABLE     = 3,
 113        TICK_DEP_BIT_RCU                = 4,
 114        TICK_DEP_BIT_RCU_EXP            = 5
 115};
 116#define TICK_DEP_BIT_MAX TICK_DEP_BIT_RCU_EXP
 117
 118#define TICK_DEP_MASK_NONE              0
 119#define TICK_DEP_MASK_POSIX_TIMER       (1 << TICK_DEP_BIT_POSIX_TIMER)
 120#define TICK_DEP_MASK_PERF_EVENTS       (1 << TICK_DEP_BIT_PERF_EVENTS)
 121#define TICK_DEP_MASK_SCHED             (1 << TICK_DEP_BIT_SCHED)
 122#define TICK_DEP_MASK_CLOCK_UNSTABLE    (1 << TICK_DEP_BIT_CLOCK_UNSTABLE)
 123#define TICK_DEP_MASK_RCU               (1 << TICK_DEP_BIT_RCU)
 124#define TICK_DEP_MASK_RCU_EXP           (1 << TICK_DEP_BIT_RCU_EXP)
 125
 126#ifdef CONFIG_NO_HZ_COMMON
 127extern bool tick_nohz_enabled;
 128extern bool tick_nohz_tick_stopped(void);
 129extern bool tick_nohz_tick_stopped_cpu(int cpu);
 130extern void tick_nohz_idle_stop_tick(void);
 131extern void tick_nohz_idle_retain_tick(void);
 132extern void tick_nohz_idle_restart_tick(void);
 133extern void tick_nohz_idle_enter(void);
 134extern void tick_nohz_idle_exit(void);
 135extern void tick_nohz_irq_exit(void);
 136extern bool tick_nohz_idle_got_tick(void);
 137extern ktime_t tick_nohz_get_next_hrtimer(void);
 138extern ktime_t tick_nohz_get_sleep_length(ktime_t *delta_next);
 139extern unsigned long tick_nohz_get_idle_calls(void);
 140extern unsigned long tick_nohz_get_idle_calls_cpu(int cpu);
 141extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time);
 142extern u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time);
 143
 144static inline void tick_nohz_idle_stop_tick_protected(void)
 145{
 146        local_irq_disable();
 147        tick_nohz_idle_stop_tick();
 148        local_irq_enable();
 149}
 150
 151#else /* !CONFIG_NO_HZ_COMMON */
 152#define tick_nohz_enabled (0)
 153static inline int tick_nohz_tick_stopped(void) { return 0; }
 154static inline int tick_nohz_tick_stopped_cpu(int cpu) { return 0; }
 155static inline void tick_nohz_idle_stop_tick(void) { }
 156static inline void tick_nohz_idle_retain_tick(void) { }
 157static inline void tick_nohz_idle_restart_tick(void) { }
 158static inline void tick_nohz_idle_enter(void) { }
 159static inline void tick_nohz_idle_exit(void) { }
 160static inline bool tick_nohz_idle_got_tick(void) { return false; }
 161static inline ktime_t tick_nohz_get_next_hrtimer(void)
 162{
 163        /* Next wake up is the tick period, assume it starts now */
 164        return ktime_add(ktime_get(), TICK_NSEC);
 165}
 166static inline ktime_t tick_nohz_get_sleep_length(ktime_t *delta_next)
 167{
 168        *delta_next = TICK_NSEC;
 169        return *delta_next;
 170}
 171static inline u64 get_cpu_idle_time_us(int cpu, u64 *unused) { return -1; }
 172static inline u64 get_cpu_iowait_time_us(int cpu, u64 *unused) { return -1; }
 173
 174static inline void tick_nohz_idle_stop_tick_protected(void) { }
 175#endif /* !CONFIG_NO_HZ_COMMON */
 176
 177#ifdef CONFIG_NO_HZ_FULL
 178extern bool tick_nohz_full_running;
 179extern cpumask_var_t tick_nohz_full_mask;
 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);
 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) { }
 283
 284static inline void tick_dep_set(enum tick_dep_bits bit) { }
 285static inline void tick_dep_clear(enum tick_dep_bits bit) { }
 286static inline void tick_dep_set_cpu(int cpu, enum tick_dep_bits bit) { }
 287static inline void tick_dep_clear_cpu(int cpu, enum tick_dep_bits bit) { }
 288static inline void tick_dep_set_task(struct task_struct *tsk,
 289                                     enum tick_dep_bits bit) { }
 290static inline void tick_dep_clear_task(struct task_struct *tsk,
 291                                       enum tick_dep_bits bit) { }
 292static inline void tick_dep_set_signal(struct task_struct *tsk,
 293                                       enum tick_dep_bits bit) { }
 294static inline void tick_dep_clear_signal(struct signal_struct *signal,
 295                                         enum tick_dep_bits bit) { }
 296
 297static inline void tick_nohz_full_kick_cpu(int cpu) { }
 298static inline void __tick_nohz_task_switch(void) { }
 299static inline void tick_nohz_full_setup(cpumask_var_t cpumask) { }
 300#endif
 301
 302static inline void tick_nohz_task_switch(void)
 303{
 304        if (tick_nohz_full_enabled())
 305                __tick_nohz_task_switch();
 306}
 307
 308static 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