include/linux/tick.h

   1 /*  linux/include/linux/tick.h
   2  *
   3  *  This file contains the structure definitions for tick related functions
   4  *
   5  */
   6 #ifndef _LINUX_TICK_H
   7 #define _LINUX_TICK_H
   8
   9 #include <linux/clockchips.h>
  10 #include <linux/irqflags.h>
  11 #include <linux/percpu.h>
  12 #include <linux/hrtimer.h>
  13 #include <linux/context_tracking_state.h>
  14 #include <linux/cpumask.h>
  15
  16 #ifdef CONFIG_GENERIC_CLOCKEVENTS
  17
  18 enum tick_device_mode {
  19         TICKDEV_MODE_PERIODIC,
  20         TICKDEV_MODE_ONESHOT,
  21 };
  22
  23 struct tick_device {
  24         struct clock_event_device *evtdev;
  25         enum tick_device_mode mode;
  26 };
  27
  28 enum tick_nohz_mode {
  29         NOHZ_MODE_INACTIVE,
  30         NOHZ_MODE_LOWRES,
  31         NOHZ_MODE_HIGHRES,
  32 };
  33
  34 /**
  35  * struct tick_sched - sched tick emulation and no idle tick control/stats
  36  * @sched_timer:        hrtimer to schedule the periodic tick in high
  37  *                      resolution mode
  38  * @last_tick:          Store the last tick expiry time when the tick
  39  *                      timer is modified for nohz sleeps. This is necessary
  40  *                      to resume the tick timer operation in the timeline
  41  *                      when the CPU returns from nohz sleep.
  42  * @tick_stopped:       Indicator that the idle tick has been stopped
  43  * @idle_jiffies:       jiffies at the entry to idle for idle time accounting
  44  * @idle_calls:         Total number of idle calls
  45  * @idle_sleeps:        Number of idle calls, where the sched tick was stopped
  46  * @idle_entrytime:     Time when the idle call was entered
  47  * @idle_waketime:      Time when the idle was interrupted
  48  * @idle_exittime:      Time when the idle state was left
  49  * @idle_sleeptime:     Sum of the time slept in idle with sched tick stopped
  50  * @iowait_sleeptime:   Sum of the time slept in idle with sched tick stopped, with IO outstanding
  51  * @sleep_length:       Duration of the current idle sleep
  52  * @do_timer_lst:       CPU was the last one doing do_timer before going idle
  53  */
  54 struct tick_sched {
  55         struct hrtimer                  sched_timer;
  56         unsigned long                   check_clocks;
  57         enum tick_nohz_mode             nohz_mode;
  58         ktime_t                         last_tick;
  59         int                             inidle;
  60         int                             tick_stopped;
  61         unsigned long                   idle_jiffies;
  62         unsigned long                   idle_calls;
  63         unsigned long                   idle_sleeps;
  64         int                             idle_active;
  65         ktime_t                         idle_entrytime;
  66         ktime_t                         idle_waketime;
  67         ktime_t                         idle_exittime;
  68         ktime_t                         idle_sleeptime;
  69         ktime_t                         iowait_sleeptime;
  70         ktime_t                         sleep_length;
  71         unsigned long                   last_jiffies;
  72         unsigned long                   next_jiffies;
  73         ktime_t                         idle_expires;
  74         int                             do_timer_last;
  75 };
  76
  77 extern void __init tick_init(void);
  78 extern int tick_is_oneshot_available(void);
  79 extern struct tick_device *tick_get_device(int cpu);
  80
  81 # ifdef CONFIG_HIGH_RES_TIMERS
  82 extern int tick_init_highres(void);
  83 extern int tick_program_event(ktime_t expires, int force);
  84 extern void tick_setup_sched_timer(void);
  85 # endif
  86
  87 # if defined CONFIG_NO_HZ_COMMON || defined CONFIG_HIGH_RES_TIMERS
  88 extern void tick_cancel_sched_timer(int cpu);
  89 # else
  90 static inline void tick_cancel_sched_timer(int cpu) { }
  91 # endif
  92
  93 # ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
  94 extern struct tick_device *tick_get_broadcast_device(void);
  95 extern struct cpumask *tick_get_broadcast_mask(void);
  96
  97 #  ifdef CONFIG_TICK_ONESHOT
  98 extern struct cpumask *tick_get_broadcast_oneshot_mask(void);
  99 #  endif
 100
 101 # endif /* BROADCAST */
 102
 103 # ifdef CONFIG_TICK_ONESHOT
 104 extern void tick_clock_notify(void);
 105 extern int tick_check_oneshot_change(int allow_nohz);
 106 extern struct tick_sched *tick_get_tick_sched(int cpu);
 107 extern void tick_irq_enter(void);
 108 extern int tick_oneshot_mode_active(void);
 109 #  ifndef arch_needs_cpu
 110 #   define arch_needs_cpu(cpu) (0)
 111 #  endif
 112 # else
 113 static inline void tick_clock_notify(void) { }
 114 static inline int tick_check_oneshot_change(int allow_nohz) { return 0; }
 115 static inline void tick_irq_enter(void) { }
 116 static inline int tick_oneshot_mode_active(void) { return 0; }
 117 # endif
 118
 119 #else /* CONFIG_GENERIC_CLOCKEVENTS */
 120 static inline void tick_init(void) { }
 121 static inline void tick_cancel_sched_timer(int cpu) { }
 122 static inline void tick_clock_notify(void) { }
 123 static inline int tick_check_oneshot_change(int allow_nohz) { return 0; }
 124 static inline void tick_irq_enter(void) { }
 125 static inline int tick_oneshot_mode_active(void) { return 0; }
 126 #endif /* !CONFIG_GENERIC_CLOCKEVENTS */
 127
 128 # ifdef CONFIG_NO_HZ_COMMON
 129 DECLARE_PER_CPU(struct tick_sched, tick_cpu_sched);
 130
 131 static inline int tick_nohz_tick_stopped(void)
 132 {
 133         return __this_cpu_read(tick_cpu_sched.tick_stopped);
 134 }
 135
 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 ktime_t tick_nohz_get_sleep_length(void);
 140 extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time);
 141 extern u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time);
 142
 143 # else /* !CONFIG_NO_HZ_COMMON */
 144 static inline int tick_nohz_tick_stopped(void)
 145 {
 146         return 0;
 147 }
 148
 149 static inline void tick_nohz_idle_enter(void) { }
 150 static inline void tick_nohz_idle_exit(void) { }
 151
 152 static inline ktime_t tick_nohz_get_sleep_length(void)
 153 {
 154         ktime_t len = { .tv64 = NSEC_PER_SEC/HZ };
 155
 156         return len;
 157 }
 158 static inline u64 get_cpu_idle_time_us(int cpu, u64 *unused) { return -1; }
 159 static inline u64 get_cpu_iowait_time_us(int cpu, u64 *unused) { return -1; }
 160 # endif /* !CONFIG_NO_HZ_COMMON */
 161
 162 #ifdef CONFIG_NO_HZ_FULL
 163 extern bool tick_nohz_full_running;
 164 extern cpumask_var_t tick_nohz_full_mask;
 165
 166 static inline bool tick_nohz_full_enabled(void)
 167 {
 168         if (!context_tracking_is_enabled())
 169                 return false;
 170
 171         return tick_nohz_full_running;
 172 }
 173
 174 static inline bool tick_nohz_full_cpu(int cpu)
 175 {
 176         if (!tick_nohz_full_enabled())
 177                 return false;
 178
 179         return cpumask_test_cpu(cpu, tick_nohz_full_mask);
 180 }
 181
 182 extern void tick_nohz_init(void);
 183 extern void __tick_nohz_full_check(void);
 184 extern void tick_nohz_full_kick(void);
 185 extern void tick_nohz_full_kick_all(void);
 186 extern void __tick_nohz_task_switch(struct task_struct *tsk);
 187 #else
 188 static inline void tick_nohz_init(void) { }
 189 static inline bool tick_nohz_full_enabled(void) { return false; }
 190 static inline bool tick_nohz_full_cpu(int cpu) { return false; }
 191 static inline void __tick_nohz_full_check(void) { }
 192 static inline void tick_nohz_full_kick(void) { }
 193 static inline void tick_nohz_full_kick_all(void) { }
 194 static inline void __tick_nohz_task_switch(struct task_struct *tsk) { }
 195 #endif
 196
 197 static inline void tick_nohz_full_check(void)
 198 {
 199         if (tick_nohz_full_enabled())
 200                 __tick_nohz_full_check();
 201 }
 202
 203 static inline void tick_nohz_task_switch(struct task_struct *tsk)
 204 {
 205         if (tick_nohz_full_enabled())
 206                 __tick_nohz_task_switch(tsk);
 207 }
 208
 209
 210 #endif