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 * @sleep_length:       Duration of the current idle sleep
  46 * @do_timer_lst:       CPU was the last one doing do_timer before going idle
  47 */
  48struct tick_sched {
  49        struct hrtimer                  sched_timer;
  50        unsigned long                   check_clocks;
  51        enum tick_nohz_mode             nohz_mode;
  52        ktime_t                         idle_tick;
  53        int                             inidle;
  54        int                             tick_stopped;
  55        unsigned long                   idle_jiffies;
  56        unsigned long                   idle_calls;
  57        unsigned long                   idle_sleeps;
  58        int                             idle_active;
  59        ktime_t                         idle_entrytime;
  60        ktime_t                         idle_waketime;
  61        ktime_t                         idle_exittime;
  62        ktime_t                         idle_sleeptime;
  63        ktime_t                         idle_lastupdate;
  64        ktime_t                         sleep_length;
  65        unsigned long                   last_jiffies;
  66        unsigned long                   next_jiffies;
  67        ktime_t                         idle_expires;
  68        int                             do_timer_last;
  69};
  70
  71extern void __init tick_init(void);
  72extern int tick_is_oneshot_available(void);
  73extern struct tick_device *tick_get_device(int cpu);
  74
  75# ifdef CONFIG_HIGH_RES_TIMERS
  76extern int tick_init_highres(void);
  77extern int tick_program_event(ktime_t expires, int force);
  78extern void tick_setup_sched_timer(void);
  79# endif
  80
  81# if defined CONFIG_NO_HZ || defined CONFIG_HIGH_RES_TIMERS
  82extern void tick_cancel_sched_timer(int cpu);
  83# else
  84static inline void tick_cancel_sched_timer(int cpu) { }
  85# endif
  86
  87# ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
  88extern struct tick_device *tick_get_broadcast_device(void);
  89extern struct cpumask *tick_get_broadcast_mask(void);
  90
  91#  ifdef CONFIG_TICK_ONESHOT
  92extern struct cpumask *tick_get_broadcast_oneshot_mask(void);
  93#  endif
  94
  95# endif /* BROADCAST */
  96
  97# ifdef CONFIG_TICK_ONESHOT
  98extern void tick_clock_notify(void);
  99extern int tick_check_oneshot_change(int allow_nohz);
 100extern struct tick_sched *tick_get_tick_sched(int cpu);
 101extern void tick_check_idle(int cpu);
 102extern int tick_oneshot_mode_active(void);
 103#  ifndef arch_needs_cpu
 104#   define arch_needs_cpu(cpu) (0)
 105#  endif
 106# else
 107static inline void tick_clock_notify(void) { }
 108static inline int tick_check_oneshot_change(int allow_nohz) { return 0; }
 109static inline void tick_check_idle(int cpu) { }
 110static inline int tick_oneshot_mode_active(void) { return 0; }
 111# endif
 112
 113#else /* CONFIG_GENERIC_CLOCKEVENTS */
 114static inline void tick_init(void) { }
 115static inline void tick_cancel_sched_timer(int cpu) { }
 116static inline void tick_clock_notify(void) { }
 117static inline int tick_check_oneshot_change(int allow_nohz) { return 0; }
 118static inline void tick_check_idle(int cpu) { }
 119static inline int tick_oneshot_mode_active(void) { return 0; }
 120#endif /* !CONFIG_GENERIC_CLOCKEVENTS */
 121
 122# ifdef CONFIG_NO_HZ
 123extern void tick_nohz_stop_sched_tick(int inidle);
 124extern void tick_nohz_restart_sched_tick(void);
 125extern ktime_t tick_nohz_get_sleep_length(void);
 126extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time);
 127# else
 128static inline void tick_nohz_stop_sched_tick(int inidle) { }
 129static inline void tick_nohz_restart_sched_tick(void) { }
 130static inline ktime_t tick_nohz_get_sleep_length(void)
 131{
 132        ktime_t len = { .tv64 = NSEC_PER_SEC/HZ };
 133
 134        return len;
 135}
 136static inline u64 get_cpu_idle_time_us(int cpu, u64 *unused) { return -1; }
 137# endif /* !NO_HZ */
 138
 139#endif
 140