kernel/time/tick-internal.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * tick internal variable and functions used by low/high res code
   4  */
   5 #include <linux/hrtimer.h>
   6 #include <linux/tick.h>
   7
   8 #include "timekeeping.h"
   9 #include "tick-sched.h"
  10
  11 struct timer_events {
  12         u64     local;
  13         u64     global;
  14 };
  15
  16 #ifdef CONFIG_GENERIC_CLOCKEVENTS
  17
  18 # define TICK_DO_TIMER_NONE     -1
  19 # define TICK_DO_TIMER_BOOT     -2
  20
  21 DECLARE_PER_CPU(struct tick_device, tick_cpu_device);
  22 extern ktime_t tick_next_period;
  23 extern int tick_do_timer_cpu __read_mostly;
  24
  25 extern void tick_setup_periodic(struct clock_event_device *dev, int broadcast);
  26 extern void tick_handle_periodic(struct clock_event_device *dev);
  27 extern void tick_check_new_device(struct clock_event_device *dev);
  28 extern void tick_offline_cpu(unsigned int cpu);
  29 extern void tick_shutdown(unsigned int cpu);
  30 extern void tick_suspend(void);
  31 extern void tick_resume(void);
  32 extern bool tick_check_replacement(struct clock_event_device *curdev,
  33                                    struct clock_event_device *newdev);
  34 extern void tick_install_replacement(struct clock_event_device *dev);
  35 extern int tick_is_oneshot_available(void);
  36 extern struct tick_device *tick_get_device(int cpu);
  37
  38 extern int clockevents_tick_resume(struct clock_event_device *dev);
  39 /* Check, if the device is functional or a dummy for broadcast */
  40 static inline int tick_device_is_functional(struct clock_event_device *dev)
  41 {
  42         return !(dev->features & CLOCK_EVT_FEAT_DUMMY);
  43 }
  44
  45 static inline enum clock_event_state clockevent_get_state(struct clock_event_device *dev)
  46 {
  47         return dev->state_use_accessors;
  48 }
  49
  50 static inline void clockevent_set_state(struct clock_event_device *dev,
  51                                         enum clock_event_state state)
  52 {
  53         dev->state_use_accessors = state;
  54 }
  55
  56 extern void clockevents_shutdown(struct clock_event_device *dev);
  57 extern void clockevents_exchange_device(struct clock_event_device *old,
  58                                         struct clock_event_device *new);
  59 extern void clockevents_switch_state(struct clock_event_device *dev,
  60                                      enum clock_event_state state);
  61 extern int clockevents_program_event(struct clock_event_device *dev,
  62                                      ktime_t expires, bool force);
  63 extern void clockevents_handle_noop(struct clock_event_device *dev);
  64 extern int __clockevents_update_freq(struct clock_event_device *dev, u32 freq);
  65
  66 /* Broadcasting support */
  67 # ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
  68 extern int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu);
  69 extern void tick_install_broadcast_device(struct clock_event_device *dev, int cpu);
  70 extern int tick_is_broadcast_device(struct clock_event_device *dev);
  71 extern void tick_suspend_broadcast(void);
  72 extern void tick_resume_broadcast(void);
  73 extern bool tick_resume_check_broadcast(void);
  74 extern void tick_broadcast_init(void);
  75 extern void tick_set_periodic_handler(struct clock_event_device *dev, int broadcast);
  76 extern int tick_broadcast_update_freq(struct clock_event_device *dev, u32 freq);
  77 extern struct tick_device *tick_get_broadcast_device(void);
  78 extern struct cpumask *tick_get_broadcast_mask(void);
  79 extern const struct clock_event_device *tick_get_wakeup_device(int cpu);
  80 # else /* !CONFIG_GENERIC_CLOCKEVENTS_BROADCAST: */
  81 static inline void tick_install_broadcast_device(struct clock_event_device *dev, int cpu) { }
  82 static inline int tick_is_broadcast_device(struct clock_event_device *dev) { return 0; }
  83 static inline int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu) { return 0; }
  84 static inline void tick_do_periodic_broadcast(struct clock_event_device *d) { }
  85 static inline void tick_suspend_broadcast(void) { }
  86 static inline void tick_resume_broadcast(void) { }
  87 static inline bool tick_resume_check_broadcast(void) { return false; }
  88 static inline void tick_broadcast_init(void) { }
  89 static inline int tick_broadcast_update_freq(struct clock_event_device *dev, u32 freq) { return -ENODEV; }
  90
  91 /* Set the periodic handler in non broadcast mode */
  92 static inline void tick_set_periodic_handler(struct clock_event_device *dev, int broadcast)
  93 {
  94         dev->event_handler = tick_handle_periodic;
  95 }
  96 # endif /* !CONFIG_GENERIC_CLOCKEVENTS_BROADCAST */
  97
  98 #else /* !GENERIC_CLOCKEVENTS: */
  99 static inline void tick_suspend(void) { }
 100 static inline void tick_resume(void) { }
 101 #endif /* !GENERIC_CLOCKEVENTS */
 102
 103 /* Oneshot related functions */
 104 #ifdef CONFIG_TICK_ONESHOT
 105 extern void tick_setup_oneshot(struct clock_event_device *newdev,
 106                                void (*handler)(struct clock_event_device *),
 107                                ktime_t nextevt);
 108 extern int tick_program_event(ktime_t expires, int force);
 109 extern void tick_oneshot_notify(void);
 110 extern int tick_switch_to_oneshot(void (*handler)(struct clock_event_device *));
 111 extern void tick_resume_oneshot(void);
 112 static inline bool tick_oneshot_possible(void) { return true; }
 113 extern int tick_oneshot_mode_active(void);
 114 extern void tick_clock_notify(void);
 115 extern int tick_check_oneshot_change(int allow_nohz);
 116 extern int tick_init_highres(void);
 117 #else /* !CONFIG_TICK_ONESHOT: */
 118 static inline
 119 void tick_setup_oneshot(struct clock_event_device *newdev,
 120                         void (*handler)(struct clock_event_device *),
 121                         ktime_t nextevt) { BUG(); }
 122 static inline void tick_resume_oneshot(void) { BUG(); }
 123 static inline int tick_program_event(ktime_t expires, int force) { return 0; }
 124 static inline void tick_oneshot_notify(void) { }
 125 static inline bool tick_oneshot_possible(void) { return false; }
 126 static inline int tick_oneshot_mode_active(void) { return 0; }
 127 static inline void tick_clock_notify(void) { }
 128 static inline int tick_check_oneshot_change(int allow_nohz) { return 0; }
 129 #endif /* !CONFIG_TICK_ONESHOT */
 130
 131 /* Functions related to oneshot broadcasting */
 132 #if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT)
 133 extern void tick_broadcast_switch_to_oneshot(void);
 134 extern int tick_broadcast_oneshot_active(void);
 135 extern void tick_check_oneshot_broadcast_this_cpu(void);
 136 bool tick_broadcast_oneshot_available(void);
 137 extern struct cpumask *tick_get_broadcast_oneshot_mask(void);
 138 #else /* !(BROADCAST && ONESHOT): */
 139 static inline void tick_broadcast_switch_to_oneshot(void) { }
 140 static inline int tick_broadcast_oneshot_active(void) { return 0; }
 141 static inline void tick_check_oneshot_broadcast_this_cpu(void) { }
 142 static inline bool tick_broadcast_oneshot_available(void) { return tick_oneshot_possible(); }
 143 #endif /* !(BROADCAST && ONESHOT) */
 144
 145 #if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_HOTPLUG_CPU)
 146 extern void tick_broadcast_offline(unsigned int cpu);
 147 #else
 148 static inline void tick_broadcast_offline(unsigned int cpu) { }
 149 #endif
 150
 151 /* NO_HZ_FULL internal */
 152 #ifdef CONFIG_NO_HZ_FULL
 153 extern void tick_nohz_init(void);
 154 # else
 155 static inline void tick_nohz_init(void) { }
 156 #endif
 157
 158 #ifdef CONFIG_NO_HZ_COMMON
 159 extern unsigned long tick_nohz_active;
 160 extern void timers_update_nohz(void);
 161 extern u64 get_jiffies_update(unsigned long *basej);
 162 # ifdef CONFIG_SMP
 163 extern struct static_key_false timers_migration_enabled;
 164 extern void fetch_next_timer_interrupt_remote(unsigned long basej, u64 basem,
 165                                               struct timer_events *tevt,
 166                                               unsigned int cpu);
 167 extern void timer_lock_remote_bases(unsigned int cpu);
 168 extern void timer_unlock_remote_bases(unsigned int cpu);
 169 extern bool timer_base_is_idle(void);
 170 extern void timer_expire_remote(unsigned int cpu);
 171 # endif
 172 #else /* CONFIG_NO_HZ_COMMON */
 173 static inline void timers_update_nohz(void) { }
 174 #define tick_nohz_active (0)
 175 #endif
 176
 177 DECLARE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases);
 178
 179 extern u64 get_next_timer_interrupt(unsigned long basej, u64 basem);
 180 u64 timer_base_try_to_set_idle(unsigned long basej, u64 basem, bool *idle);
 181 void timer_clear_idle(void);
 182
 183 #define CLOCK_SET_WALL                                                  \
 184         (BIT(HRTIMER_BASE_REALTIME) | BIT(HRTIMER_BASE_REALTIME_SOFT) | \
 185          BIT(HRTIMER_BASE_TAI) | BIT(HRTIMER_BASE_TAI_SOFT))
 186
 187 #define CLOCK_SET_BOOT                                                  \
 188         (BIT(HRTIMER_BASE_BOOTTIME) | BIT(HRTIMER_BASE_BOOTTIME_SOFT))
 189
 190 void clock_was_set(unsigned int bases);
 191 void clock_was_set_delayed(void);
 192
 193 void hrtimers_resume_local(void);
 194
 195 /* Since jiffies uses a simple TICK_NSEC multiplier
 196  * conversion, the .shift value could be zero. However
 197  * this would make NTP adjustments impossible as they are
 198  * in units of 1/2^.shift. Thus we use JIFFIES_SHIFT to
 199  * shift both the nominator and denominator the same
 200  * amount, and give ntp adjustments in units of 1/2^8
 201  *
 202  * The value 8 is somewhat carefully chosen, as anything
 203  * larger can result in overflows. TICK_NSEC grows as HZ
 204  * shrinks, so values greater than 8 overflow 32bits when
 205  * HZ=100.
 206  */
 207 #if HZ < 34
 208 #define JIFFIES_SHIFT   6
 209 #elif HZ < 67
 210 #define JIFFIES_SHIFT   7
 211 #else
 212 #define JIFFIES_SHIFT   8
 213 #endif
 214
 215 extern ssize_t sysfs_get_uname(const char *buf, char *dst, size_t cnt);