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
 11struct 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
 21DECLARE_PER_CPU(struct tick_device, tick_cpu_device);
 22extern ktime_t tick_next_period;
 23extern int tick_do_timer_cpu __read_mostly;
 24
 25extern void tick_setup_periodic(struct clock_event_device *dev, int broadcast);
 26extern void tick_handle_periodic(struct clock_event_device *dev);
 27extern void tick_check_new_device(struct clock_event_device *dev);
 28extern void tick_offline_cpu(unsigned int cpu);
 29extern void tick_shutdown(void);
 30extern void tick_suspend(void);
 31extern void tick_resume(void);
 32extern bool tick_check_replacement(struct clock_event_device *curdev,
 33				   struct clock_event_device *newdev);
 34extern void tick_install_replacement(struct clock_event_device *dev);
 35extern int tick_is_oneshot_available(void);
 36extern struct tick_device *tick_get_device(int cpu);
 37
 38extern int clockevents_tick_resume(struct clock_event_device *dev);
 39/* Check, if the device is functional or a dummy for broadcast */
 40static inline int tick_device_is_functional(struct clock_event_device *dev)
 41{
 42	return !(dev->features & CLOCK_EVT_FEAT_DUMMY);
 43}
 44
 45static inline enum clock_event_state clockevent_get_state(struct clock_event_device *dev)
 46{
 47	return dev->state_use_accessors;
 48}
 49
 50static 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
 56extern void clockevents_shutdown(struct clock_event_device *dev);
 57extern void clockevents_exchange_device(struct clock_event_device *old,
 58					struct clock_event_device *new);
 59extern void clockevents_switch_state(struct clock_event_device *dev,
 60				     enum clock_event_state state);
 61extern int clockevents_program_event(struct clock_event_device *dev,
 62				     ktime_t expires, bool force);
 63extern void clockevents_handle_noop(struct clock_event_device *dev);
 64extern int __clockevents_update_freq(struct clock_event_device *dev, u32 freq);
 65
 66/* Broadcasting support */
 67# ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
 68extern int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu);
 69extern void tick_install_broadcast_device(struct clock_event_device *dev, int cpu);
 70extern int tick_is_broadcast_device(struct clock_event_device *dev);
 71extern void tick_suspend_broadcast(void);
 72extern void tick_resume_broadcast(void);
 73extern bool tick_resume_check_broadcast(void);
 74extern void tick_broadcast_init(void);
 75extern void tick_set_periodic_handler(struct clock_event_device *dev, int broadcast);
 76extern int tick_broadcast_update_freq(struct clock_event_device *dev, u32 freq);
 77extern struct tick_device *tick_get_broadcast_device(void);
 78extern struct cpumask *tick_get_broadcast_mask(void);
 79extern const struct clock_event_device *tick_get_wakeup_device(int cpu);
 80# else /* !CONFIG_GENERIC_CLOCKEVENTS_BROADCAST: */
 81static inline void tick_install_broadcast_device(struct clock_event_device *dev, int cpu) { }
 82static inline int tick_is_broadcast_device(struct clock_event_device *dev) { return 0; }
 83static inline int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu) { return 0; }
 84static inline void tick_do_periodic_broadcast(struct clock_event_device *d) { }
 85static inline void tick_suspend_broadcast(void) { }
 86static inline void tick_resume_broadcast(void) { }
 87static inline bool tick_resume_check_broadcast(void) { return false; }
 88static inline void tick_broadcast_init(void) { }
 89static 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 */
 92static 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: */
 99static inline void tick_suspend(void) { }
100static inline void tick_resume(void) { }
101#endif /* !GENERIC_CLOCKEVENTS */
102
103/* Oneshot related functions */
104#ifdef CONFIG_TICK_ONESHOT
105extern void tick_setup_oneshot(struct clock_event_device *newdev,
106			       void (*handler)(struct clock_event_device *),
107			       ktime_t nextevt);
108extern int tick_program_event(ktime_t expires, int force);
109extern void tick_oneshot_notify(void);
110extern int tick_switch_to_oneshot(void (*handler)(struct clock_event_device *));
111extern void tick_resume_oneshot(void);
112static inline bool tick_oneshot_possible(void) { return true; }
113extern int tick_oneshot_mode_active(void);
114extern void tick_clock_notify(void);
115extern int tick_check_oneshot_change(int allow_nohz);
116extern int tick_init_highres(void);
117#else /* !CONFIG_TICK_ONESHOT: */
118static inline
119void tick_setup_oneshot(struct clock_event_device *newdev,
120			void (*handler)(struct clock_event_device *),
121			ktime_t nextevt) { BUG(); }
122static inline void tick_resume_oneshot(void) { BUG(); }
123static inline int tick_program_event(ktime_t expires, int force) { return 0; }
124static inline void tick_oneshot_notify(void) { }
125static inline bool tick_oneshot_possible(void) { return false; }
126static inline int tick_oneshot_mode_active(void) { return 0; }
127static inline void tick_clock_notify(void) { }
128static 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)
133extern void tick_broadcast_switch_to_oneshot(void);
134extern int tick_broadcast_oneshot_active(void);
135extern void tick_check_oneshot_broadcast_this_cpu(void);
136bool tick_broadcast_oneshot_available(void);
137extern struct cpumask *tick_get_broadcast_oneshot_mask(void);
138#else /* !(BROADCAST && ONESHOT): */
139static inline void tick_broadcast_switch_to_oneshot(void) { }
140static inline int tick_broadcast_oneshot_active(void) { return 0; }
141static inline void tick_check_oneshot_broadcast_this_cpu(void) { }
142static 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)
146extern void tick_broadcast_offline(unsigned int cpu);
147#else
148static inline void tick_broadcast_offline(unsigned int cpu) { }
149#endif
150
151/* NO_HZ_FULL internal */
152#ifdef CONFIG_NO_HZ_FULL
153extern void tick_nohz_init(void);
154# else
155static inline void tick_nohz_init(void) { }
156#endif
157
158#ifdef CONFIG_NO_HZ_COMMON
159extern unsigned long tick_nohz_active;
160extern void timers_update_nohz(void);
161extern u64 get_jiffies_update(unsigned long *basej);
162# ifdef CONFIG_SMP
163extern struct static_key_false timers_migration_enabled;
164extern void fetch_next_timer_interrupt_remote(unsigned long basej, u64 basem,
165					      struct timer_events *tevt,
166					      unsigned int cpu);
167extern void timer_lock_remote_bases(unsigned int cpu);
168extern void timer_unlock_remote_bases(unsigned int cpu);
169extern bool timer_base_is_idle(void);
170extern void timer_expire_remote(unsigned int cpu);
171# endif
172#else /* CONFIG_NO_HZ_COMMON */
173static inline void timers_update_nohz(void) { }
174#define tick_nohz_active (0)
175#endif
176
177DECLARE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases);
178
179extern u64 get_next_timer_interrupt(unsigned long basej, u64 basem);
180u64 timer_base_try_to_set_idle(unsigned long basej, u64 basem, bool *idle);
181void 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
190void clock_was_set(unsigned int bases);
191void clock_was_set_delayed(void);
192
193void 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
215extern ssize_t sysfs_get_uname(const char *buf, char *dst, size_t cnt);