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_shutdown(unsigned int cpu);
29extern void tick_suspend(void);
30extern void tick_resume(void);
31extern bool tick_check_replacement(struct clock_event_device *curdev,
32				   struct clock_event_device *newdev);
33extern void tick_install_replacement(struct clock_event_device *dev);
34extern int tick_is_oneshot_available(void);
35extern struct tick_device *tick_get_device(int cpu);
36
37extern int clockevents_tick_resume(struct clock_event_device *dev);
38/* Check, if the device is functional or a dummy for broadcast */
39static inline int tick_device_is_functional(struct clock_event_device *dev)
40{
41	return !(dev->features & CLOCK_EVT_FEAT_DUMMY);
42}
43
44static inline enum clock_event_state clockevent_get_state(struct clock_event_device *dev)
45{
46	return dev->state_use_accessors;
47}
48
49static inline void clockevent_set_state(struct clock_event_device *dev,
50					enum clock_event_state state)
51{
52	dev->state_use_accessors = state;
53}
54
55extern void clockevents_shutdown(struct clock_event_device *dev);
56extern void clockevents_exchange_device(struct clock_event_device *old,
57					struct clock_event_device *new);
58extern void clockevents_switch_state(struct clock_event_device *dev,
59				     enum clock_event_state state);
60extern int clockevents_program_event(struct clock_event_device *dev,
61				     ktime_t expires, bool force);
62extern void clockevents_handle_noop(struct clock_event_device *dev);
63extern int __clockevents_update_freq(struct clock_event_device *dev, u32 freq);
64
65/* Broadcasting support */
66# ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
67extern int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu);
68extern void tick_install_broadcast_device(struct clock_event_device *dev, int cpu);
69extern int tick_is_broadcast_device(struct clock_event_device *dev);
70extern void tick_suspend_broadcast(void);
71extern void tick_resume_broadcast(void);
72extern bool tick_resume_check_broadcast(void);
73extern void tick_broadcast_init(void);
74extern void tick_set_periodic_handler(struct clock_event_device *dev, int broadcast);
75extern int tick_broadcast_update_freq(struct clock_event_device *dev, u32 freq);
76extern struct tick_device *tick_get_broadcast_device(void);
77extern struct cpumask *tick_get_broadcast_mask(void);
78extern const struct clock_event_device *tick_get_wakeup_device(int cpu);
79# else /* !CONFIG_GENERIC_CLOCKEVENTS_BROADCAST: */
80static inline void tick_install_broadcast_device(struct clock_event_device *dev, int cpu) { }
81static inline int tick_is_broadcast_device(struct clock_event_device *dev) { return 0; }
82static inline int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu) { return 0; }
83static inline void tick_do_periodic_broadcast(struct clock_event_device *d) { }
84static inline void tick_suspend_broadcast(void) { }
85static inline void tick_resume_broadcast(void) { }
86static inline bool tick_resume_check_broadcast(void) { return false; }
87static inline void tick_broadcast_init(void) { }
88static inline int tick_broadcast_update_freq(struct clock_event_device *dev, u32 freq) { return -ENODEV; }
89
90/* Set the periodic handler in non broadcast mode */
91static inline void tick_set_periodic_handler(struct clock_event_device *dev, int broadcast)
92{
93	dev->event_handler = tick_handle_periodic;
94}
95# endif /* !CONFIG_GENERIC_CLOCKEVENTS_BROADCAST */
96
97#else /* !GENERIC_CLOCKEVENTS: */
98static inline void tick_suspend(void) { }
99static inline void tick_resume(void) { }
100#endif /* !GENERIC_CLOCKEVENTS */
101
102/* Oneshot related functions */
103#ifdef CONFIG_TICK_ONESHOT
104extern void tick_setup_oneshot(struct clock_event_device *newdev,
105			       void (*handler)(struct clock_event_device *),
106			       ktime_t nextevt);
107extern int tick_program_event(ktime_t expires, int force);
108extern void tick_oneshot_notify(void);
109extern int tick_switch_to_oneshot(void (*handler)(struct clock_event_device *));
110extern void tick_resume_oneshot(void);
111static inline bool tick_oneshot_possible(void) { return true; }
112extern int tick_oneshot_mode_active(void);
113extern void tick_clock_notify(void);
114extern int tick_check_oneshot_change(int allow_nohz);
115extern int tick_init_highres(void);
116#else /* !CONFIG_TICK_ONESHOT: */
117static inline
118void tick_setup_oneshot(struct clock_event_device *newdev,
119			void (*handler)(struct clock_event_device *),
120			ktime_t nextevt) { BUG(); }
121static inline void tick_resume_oneshot(void) { BUG(); }
122static inline int tick_program_event(ktime_t expires, int force) { return 0; }
123static inline void tick_oneshot_notify(void) { }
124static inline bool tick_oneshot_possible(void) { return false; }
125static inline int tick_oneshot_mode_active(void) { return 0; }
126static inline void tick_clock_notify(void) { }
127static inline int tick_check_oneshot_change(int allow_nohz) { return 0; }
128#endif /* !CONFIG_TICK_ONESHOT */
129
130/* Functions related to oneshot broadcasting */
131#if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT)
132extern void tick_broadcast_switch_to_oneshot(void);
133extern int tick_broadcast_oneshot_active(void);
134extern void tick_check_oneshot_broadcast_this_cpu(void);
135bool tick_broadcast_oneshot_available(void);
136extern struct cpumask *tick_get_broadcast_oneshot_mask(void);
137#else /* !(BROADCAST && ONESHOT): */
138static inline void tick_broadcast_switch_to_oneshot(void) { }
139static inline int tick_broadcast_oneshot_active(void) { return 0; }
140static inline void tick_check_oneshot_broadcast_this_cpu(void) { }
141static inline bool tick_broadcast_oneshot_available(void) { return tick_oneshot_possible(); }
142#endif /* !(BROADCAST && ONESHOT) */
143
144#if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_HOTPLUG_CPU)
145extern void tick_offline_cpu(unsigned int cpu);
146extern void tick_broadcast_offline(unsigned int cpu);
147#else
148static inline void tick_offline_cpu(unsigned int cpu) { }
149static inline void tick_broadcast_offline(unsigned int cpu) { }
150#endif
151
152/* NO_HZ_FULL internal */
153#ifdef CONFIG_NO_HZ_FULL
154extern void tick_nohz_init(void);
155# else
156static inline void tick_nohz_init(void) { }
157#endif
158
159#ifdef CONFIG_NO_HZ_COMMON
160extern unsigned long tick_nohz_active;
161extern void timers_update_nohz(void);
162extern u64 get_jiffies_update(unsigned long *basej);
163# ifdef CONFIG_SMP
164extern struct static_key_false timers_migration_enabled;
165extern void fetch_next_timer_interrupt_remote(unsigned long basej, u64 basem,
166					      struct timer_events *tevt,
167					      unsigned int cpu);
168extern void timer_lock_remote_bases(unsigned int cpu);
169extern void timer_unlock_remote_bases(unsigned int cpu);
170extern bool timer_base_is_idle(void);
171extern void timer_expire_remote(unsigned int cpu);
172# endif
173#else /* CONFIG_NO_HZ_COMMON */
174static inline void timers_update_nohz(void) { }
175#define tick_nohz_active (0)
176#endif
177
178DECLARE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases);
179
180extern u64 get_next_timer_interrupt(unsigned long basej, u64 basem);
181u64 timer_base_try_to_set_idle(unsigned long basej, u64 basem, bool *idle);
182void timer_clear_idle(void);
183
184#define CLOCK_SET_WALL							\
185	(BIT(HRTIMER_BASE_REALTIME) | BIT(HRTIMER_BASE_REALTIME_SOFT) |	\
186	 BIT(HRTIMER_BASE_TAI) | BIT(HRTIMER_BASE_TAI_SOFT))
187
188#define CLOCK_SET_BOOT							\
189	(BIT(HRTIMER_BASE_BOOTTIME) | BIT(HRTIMER_BASE_BOOTTIME_SOFT))
190
191void clock_was_set(unsigned int bases);
192void clock_was_set_delayed(void);
193
194void hrtimers_resume_local(void);
195
196/* Since jiffies uses a simple TICK_NSEC multiplier
197 * conversion, the .shift value could be zero. However
198 * this would make NTP adjustments impossible as they are
199 * in units of 1/2^.shift. Thus we use JIFFIES_SHIFT to
200 * shift both the nominator and denominator the same
201 * amount, and give ntp adjustments in units of 1/2^8
202 *
203 * The value 8 is somewhat carefully chosen, as anything
204 * larger can result in overflows. TICK_NSEC grows as HZ
205 * shrinks, so values greater than 8 overflow 32bits when
206 * HZ=100.
207 */
208#if HZ < 34
209#define JIFFIES_SHIFT	6
210#elif HZ < 67
211#define JIFFIES_SHIFT	7
212#else
213#define JIFFIES_SHIFT	8
214#endif
215
216extern ssize_t sysfs_get_uname(const char *buf, char *dst, size_t cnt);
217