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
  14 #ifdef CONFIG_GENERIC_CLOCKEVENTS
  15
  16 enum tick_device_mode {
  17         TICKDEV_MODE_PERIODIC,
  18         TICKDEV_MODE_ONESHOT,
  19 };
  20
  21 struct tick_device {
  22         struct clock_event_device *evtdev;
  23         enum tick_device_mode mode;
  24 };
  25
  26 enum tick_nohz_mode {
  27         NOHZ_MODE_INACTIVE,
  28         NOHZ_MODE_LOWRES,
  29         NOHZ_MODE_HIGHRES,
  30 };
  31
  32 /**
  33  * struct tick_sched - sched tick emulation and no idle tick control/stats
  34  * @sched_timer:        hrtimer to schedule the periodic tick in high
  35  *                      resolution mode
  36  * @last_tick:          Store the last tick expiry time when the tick
  37  *                      timer is modified for nohz sleeps. This is necessary
  38  *                      to resume the tick timer operation in the timeline
  39  *                      when the CPU returns from nohz sleep.
  40  * @tick_stopped:       Indicator that the idle tick has been stopped
  41  * @idle_jiffies:       jiffies at the entry to idle for idle time accounting
  42  * @idle_calls:         Total number of idle calls
  43  * @idle_sleeps:        Number of idle calls, where the sched tick was stopped
  44  * @idle_entrytime:     Time when the idle call was entered
  45  * @idle_waketime:      Time when the idle was interrupted
  46  * @idle_exittime:      Time when the idle state was left
  47  * @idle_sleeptime:     Sum of the time slept in idle with sched tick stopped
  48  * @iowait_sleeptime:   Sum of the time slept in idle with sched tick stopped, with IO outstanding
  49  * @sleep_length:       Duration of the current idle sleep
  50  * @do_timer_lst:       CPU was the last one doing do_timer before going idle
  51  */
  52 struct tick_sched {
  53         struct hrtimer                  sched_timer;
  54         unsigned long                   check_clocks;
  55         enum tick_nohz_mode             nohz_mode;
  56         ktime_t                         last_tick;
  57         int                             inidle;
  58         int                             tick_stopped;
  59         unsigned long                   idle_jiffies;
  60         unsigned long                   idle_calls;
  61         unsigned long                   idle_sleeps;
  62         int                             idle_active;
  63         ktime_t                         idle_entrytime;
  64         ktime_t                         idle_waketime;
  65         ktime_t                         idle_exittime;
  66         ktime_t                         idle_sleeptime;
  67         ktime_t                         iowait_sleeptime;
  68         ktime_t                         sleep_length;
  69         unsigned long                   last_jiffies;
  70         unsigned long                   next_jiffies;
  71         ktime_t                         idle_expires;
  72         int                             do_timer_last;
  73 };
  74
  75 extern void __init tick_init(void);
  76 extern int tick_is_oneshot_available(void);
  77 extern struct tick_device *tick_get_device(int cpu);
  78
  79 # ifdef CONFIG_HIGH_RES_TIMERS
  80 extern int tick_init_highres(void);
  81 extern int tick_program_event(ktime_t expires, int force);
  82 extern void tick_setup_sched_timer(void);
  83 # endif
  84
  85 # if defined CONFIG_NO_HZ || 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 struct tick_device *tick_get_broadcast_device(void);
  93 extern struct cpumask *tick_get_broadcast_mask(void);
  94
  95 #  ifdef CONFIG_TICK_ONESHOT
  96 extern struct cpumask *tick_get_broadcast_oneshot_mask(void);
  97 #  endif
  98
  99 # endif /* BROADCAST */
 100
 101 # ifdef CONFIG_TICK_ONESHOT
 102 extern void tick_clock_notify(void);
 103 extern int tick_check_oneshot_change(int allow_nohz);
 104 extern struct tick_sched *tick_get_tick_sched(int cpu);
 105 extern void tick_check_idle(int cpu);
 106 extern int tick_oneshot_mode_active(void);
 107 #  ifndef arch_needs_cpu
 108 #   define arch_needs_cpu(cpu) (0)
 109 #  endif
 110 # else
 111 static inline void tick_clock_notify(void) { }
 112 static inline int tick_check_oneshot_change(int allow_nohz) { return 0; }
 113 static inline void tick_check_idle(int cpu) { }
 114 static inline int tick_oneshot_mode_active(void) { return 0; }
 115 # endif
 116
 117 #else /* CONFIG_GENERIC_CLOCKEVENTS */
 118 static inline void tick_init(void) { }
 119 static inline void tick_cancel_sched_timer(int cpu) { }
 120 static inline void tick_clock_notify(void) { }
 121 static inline int tick_check_oneshot_change(int allow_nohz) { return 0; }
 122 static inline void tick_check_idle(int cpu) { }
 123 static inline int tick_oneshot_mode_active(void) { return 0; }
 124 #endif /* !CONFIG_GENERIC_CLOCKEVENTS */
 125
 126 # ifdef CONFIG_NO_HZ
 127 DECLARE_PER_CPU(struct tick_sched, tick_cpu_sched);
 128
 129 static inline int tick_nohz_tick_stopped(void)
 130 {
 131         return __this_cpu_read(tick_cpu_sched.tick_stopped);
 132 }
 133
 134 extern void tick_nohz_idle_enter(void);
 135 extern void tick_nohz_idle_exit(void);
 136 extern void tick_nohz_irq_exit(void);
 137 extern ktime_t tick_nohz_get_sleep_length(void);
 138 extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time);
 139 extern u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time);
 140
 141 # else /* !CONFIG_NO_HZ */
 142 static inline int tick_nohz_tick_stopped(void)
 143 {
 144         return 0;
 145 }
 146
 147 static inline void tick_nohz_idle_enter(void) { }
 148 static inline void tick_nohz_idle_exit(void) { }
 149
 150 static inline ktime_t tick_nohz_get_sleep_length(void)
 151 {
 152         ktime_t len = { .tv64 = NSEC_PER_SEC/HZ };
 153
 154         return len;
 155 }
 156 static inline u64 get_cpu_idle_time_us(int cpu, u64 *unused) { return -1; }
 157 static inline u64 get_cpu_iowait_time_us(int cpu, u64 *unused) { return -1; }
 158 # endif /* !NO_HZ */
 159
 160 # ifdef CONFIG_CPU_IDLE_GOV_MENU
 161 extern void menu_hrtimer_cancel(void);
 162 # else
 163 static inline void menu_hrtimer_cancel(void) {}
 164 # endif /* CONFIG_CPU_IDLE_GOV_MENU */
 165
 166 #endif