LXR linux/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
  11#ifdef CONFIG_GENERIC_CLOCKEVENTS
  12
  13enum tick_device_mode {
  14        TICKDEV_MODE_PERIODIC,
  15        TICKDEV_MODE_ONESHOT,
  16};
  17
  18struct tick_device {
  19        struct clock_event_device *evtdev;
  20        enum tick_device_mode mode;
  21};
  22
  23enum tick_nohz_mode {
  24        NOHZ_MODE_INACTIVE,
  25        NOHZ_MODE_LOWRES,
  26        NOHZ_MODE_HIGHRES,
  27};
  28
  29/**
  30 * struct tick_sched - sched tick emulation and no idle tick control/stats
  31 * @sched_timer:        hrtimer to schedule the periodic tick in high
  32 *                      resolution mode
  33 * @idle_tick:          Store the last idle tick expiry time when the tick
  34 *                      timer is modified for idle sleeps. This is necessary
  35 *                      to resume the tick timer operation in the timeline
  36 *                      when the CPU returns from idle
  37 * @tick_stopped:       Indicator that the idle tick has been stopped
  38 * @idle_jiffies:       jiffies at the entry to idle for idle time accounting
  39 * @idle_calls:         Total number of idle calls
  40 * @idle_sleeps:        Number of idle calls, where the sched tick was stopped
  41 * @idle_entrytime:     Time when the idle call was entered
  42 * @idle_waketime:      Time when the idle was interrupted
  43 * @idle_exittime:      Time when the idle state was left
  44 * @idle_sleeptime:     Sum of the time slept in idle with sched tick stopped
  45 * @iowait_sleeptime:   Sum of the time slept in idle with sched tick stopped, with IO outstanding
  46 * @sleep_length:       Duration of the current idle sleep
  47 * @do_timer_lst:       CPU was the last one doing do_timer before going idle
  48 */
  49struct tick_sched {
  50        struct hrtimer                  sched_timer;
  51        unsigned long                   check_clocks;
  52        enum tick_nohz_mode             nohz_mode;
  53        ktime_t                         idle_tick;
  54        int                             inidle;
  55        int                             tick_stopped;
  56        unsigned long                   idle_jiffies;
  57        unsigned long                   idle_calls;
  58        unsigned long                   idle_sleeps;
  59        int                             idle_active;
  60        ktime_t                         idle_entrytime;
  61        ktime_t                         idle_waketime;
  62        ktime_t                         idle_exittime;
  63        ktime_t                         idle_sleeptime;
  64        ktime_t                         iowait_sleeptime;
  65        ktime_t                         sleep_length;
  66        unsigned long                   last_jiffies;
  67        unsigned long                   next_jiffies;
  68        ktime_t                         idle_expires;
  69        int                             do_timer_last;
  70};
  71
  72extern void __init tick_init(void);
  73extern int tick_is_oneshot_available(void);
  74extern struct tick_device *tick_get_device(int cpu);
  75
  76# ifdef CONFIG_HIGH_RES_TIMERS
  77extern int tick_init_highres(void);
  78extern int tick_program_event(ktime_t expires, int force);
  79extern void tick_setup_sched_timer(void);
  80# endif
  81
  82# if defined CONFIG_NO_HZ || defined CONFIG_HIGH_RES_TIMERS
  83extern void tick_cancel_sched_timer(int cpu);
  84# else
  85static inline void tick_cancel_sched_timer(int cpu) { }
  86# endif
  87
  88# ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
  89extern struct tick_device *tick_get_broadcast_device(void);
  90extern struct cpumask *tick_get_broadcast_mask(void);
  91
  92#  ifdef CONFIG_TICK_ONESHOT
  93extern struct cpumask *tick_get_broadcast_oneshot_mask(void);
  94#  endif
  95
  96# endif /* BROADCAST */
  97
  98# ifdef CONFIG_TICK_ONESHOT
  99extern void tick_clock_notify(void);
 100extern int tick_check_oneshot_change(int allow_nohz);
 101extern struct tick_sched *tick_get_tick_sched(int cpu);
 102extern void tick_check_idle(int cpu);
 103extern int tick_oneshot_mode_active(void);
 104#  ifndef arch_needs_cpu
 105#   define arch_needs_cpu(cpu) (0)
 106#  endif
 107# else
 108static inline void tick_clock_notify(void) { }
 109static inline int tick_check_oneshot_change(int allow_nohz) { return 0; }
 110static inline void tick_check_idle(int cpu) { }
 111static inline int tick_oneshot_mode_active(void) { return 0; }
 112# endif
 113
 114#else /* CONFIG_GENERIC_CLOCKEVENTS */
 115static inline void tick_init(void) { }
 116static inline void tick_cancel_sched_timer(int cpu) { }
 117static inline void tick_clock_notify(void) { }
 118static inline int tick_check_oneshot_change(int allow_nohz) { return 0; }
 119static inline void tick_check_idle(int cpu) { }
 120static inline int tick_oneshot_mode_active(void) { return 0; }
 121#endif /* !CONFIG_GENERIC_CLOCKEVENTS */
 122
 123# ifdef CONFIG_NO_HZ
 124extern void tick_nohz_stop_sched_tick(int inidle);
 125extern void tick_nohz_restart_sched_tick(void);
 126extern ktime_t tick_nohz_get_sleep_length(void);
 127extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time);
 128extern u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time);
 129# else
 130static inline void tick_nohz_stop_sched_tick(int inidle) { }
 131static inline void tick_nohz_restart_sched_tick(void) { }
 132static inline ktime_t tick_nohz_get_sleep_length(void)
 133{
 134        ktime_t len = { .tv64 = NSEC_PER_SEC/HZ };
 135
 136        return len;
 137}
 138static inline u64 get_cpu_idle_time_us(int cpu, u64 *unused) { return -1; }
 139static inline u64 get_cpu_iowait_time_us(int cpu, u64 *unused) { return -1; }
 140# endif /* !NO_HZ */
 141
 142#endif
 143