kernel/time/tick-sched.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _TICK_SCHED_H
   3 #define _TICK_SCHED_H
   4
   5 #include <linux/hrtimer.h>
   6
   7 enum tick_device_mode {
   8         TICKDEV_MODE_PERIODIC,
   9         TICKDEV_MODE_ONESHOT,
  10 };
  11
  12 struct tick_device {
  13         struct clock_event_device *evtdev;
  14         enum tick_device_mode mode;
  15 };
  16
  17 enum tick_nohz_mode {
  18         NOHZ_MODE_INACTIVE,
  19         NOHZ_MODE_LOWRES,
  20         NOHZ_MODE_HIGHRES,
  21 };
  22
  23 /**
  24  * struct tick_sched - sched tick emulation and no idle tick control/stats
  25  * @sched_timer:        hrtimer to schedule the periodic tick in high
  26  *                      resolution mode
  27  * @check_clocks:       Notification mechanism about clocksource changes
  28  * @nohz_mode:          Mode - one state of tick_nohz_mode
  29  * @inidle:             Indicator that the CPU is in the tick idle mode
  30  * @tick_stopped:       Indicator that the idle tick has been stopped
  31  * @idle_active:        Indicator that the CPU is actively in the tick idle mode;
  32  *                      it is resetted during irq handling phases.
  33  * @do_timer_lst:       CPU was the last one doing do_timer before going idle
  34  * @got_idle_tick:      Tick timer function has run with @inidle set
  35  * @last_tick:          Store the last tick expiry time when the tick
  36  *                      timer is modified for nohz sleeps. This is necessary
  37  *                      to resume the tick timer operation in the timeline
  38  *                      when the CPU returns from nohz sleep.
  39  * @next_tick:          Next tick to be fired when in dynticks mode.
  40  * @idle_jiffies:       jiffies at the entry to idle for idle time accounting
  41  * @idle_calls:         Total number of idle calls
  42  * @idle_sleeps:        Number of idle calls, where the sched tick was stopped
  43  * @idle_entrytime:     Time when the idle call was entered
  44  * @idle_waketime:      Time when the idle was interrupted
  45  * @idle_exittime:      Time when the idle state was left
  46  * @idle_sleeptime:     Sum of the time slept in idle with sched tick stopped
  47  * @iowait_sleeptime:   Sum of the time slept in idle with sched tick stopped, with IO outstanding
  48  * @timer_expires:      Anticipated timer expiration time (in case sched tick is stopped)
  49  * @timer_expires_base: Base time clock monotonic for @timer_expires
  50  * @next_timer:         Expiry time of next expiring timer for debugging purpose only
  51  * @tick_dep_mask:      Tick dependency mask - is set, if someone needs the tick
  52  */
  53 struct tick_sched {
  54         struct hrtimer                  sched_timer;
  55         unsigned long                   check_clocks;
  56         enum tick_nohz_mode             nohz_mode;
  57
  58         unsigned int                    inidle          : 1;
  59         unsigned int                    tick_stopped    : 1;
  60         unsigned int                    idle_active     : 1;
  61         unsigned int                    do_timer_last   : 1;
  62         unsigned int                    got_idle_tick   : 1;
  63
  64         ktime_t                         last_tick;
  65         ktime_t                         next_tick;
  66         unsigned long                   idle_jiffies;
  67         unsigned long                   idle_calls;
  68         unsigned long                   idle_sleeps;
  69         ktime_t                         idle_entrytime;
  70         ktime_t                         idle_waketime;
  71         ktime_t                         idle_exittime;
  72         ktime_t                         idle_sleeptime;
  73         ktime_t                         iowait_sleeptime;
  74         unsigned long                   last_jiffies;
  75         u64                             timer_expires;
  76         u64                             timer_expires_base;
  77         u64                             next_timer;
  78         ktime_t                         idle_expires;
  79         atomic_t                        tick_dep_mask;
  80 };
  81
  82 extern struct tick_sched *tick_get_tick_sched(int cpu);
  83
  84 extern void tick_setup_sched_timer(void);
  85 #if defined CONFIG_NO_HZ_COMMON || defined CONFIG_HIGH_RES_TIMERS
  86 extern void tick_cancel_sched_timer(int cpu);
  87 #else
  88 static inline void tick_cancel_sched_timer(int cpu) { }
  89 #endif
  90
  91 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
  92 extern int __tick_broadcast_oneshot_control(enum tick_broadcast_state state);
  93 #else
  94 static inline int
  95 __tick_broadcast_oneshot_control(enum tick_broadcast_state state)
  96 {
  97         return -EBUSY;
  98 }
  99 #endif
 100
 101 #endif