xref: /linux/kernel/time/tick-internal.h (revision 79790b6818e96c58fe2bffee1b418c16e64e7b80)
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_shutdown(unsigned int cpu);
29 extern void tick_suspend(void);
30 extern void tick_resume(void);
31 extern bool tick_check_replacement(struct clock_event_device *curdev,
32 				   struct clock_event_device *newdev);
33 extern void tick_install_replacement(struct clock_event_device *dev);
34 extern int tick_is_oneshot_available(void);
35 extern struct tick_device *tick_get_device(int cpu);
36 
37 extern int clockevents_tick_resume(struct clock_event_device *dev);
38 /* Check, if the device is functional or a dummy for broadcast */
tick_device_is_functional(struct clock_event_device * dev)39 static inline int tick_device_is_functional(struct clock_event_device *dev)
40 {
41 	return !(dev->features & CLOCK_EVT_FEAT_DUMMY);
42 }
43 
clockevent_get_state(struct clock_event_device * dev)44 static inline enum clock_event_state clockevent_get_state(struct clock_event_device *dev)
45 {
46 	return dev->state_use_accessors;
47 }
48 
clockevent_set_state(struct clock_event_device * dev,enum clock_event_state state)49 static 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 
55 extern void clockevents_shutdown(struct clock_event_device *dev);
56 extern void clockevents_exchange_device(struct clock_event_device *old,
57 					struct clock_event_device *new);
58 extern void clockevents_switch_state(struct clock_event_device *dev,
59 				     enum clock_event_state state);
60 extern int clockevents_program_event(struct clock_event_device *dev,
61 				     ktime_t expires, bool force);
62 extern void clockevents_handle_noop(struct clock_event_device *dev);
63 extern int __clockevents_update_freq(struct clock_event_device *dev, u32 freq);
64 
65 /* Broadcasting support */
66 # ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
67 extern int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu);
68 extern void tick_install_broadcast_device(struct clock_event_device *dev, int cpu);
69 extern int tick_is_broadcast_device(struct clock_event_device *dev);
70 extern void tick_suspend_broadcast(void);
71 extern void tick_resume_broadcast(void);
72 extern bool tick_resume_check_broadcast(void);
73 extern void tick_broadcast_init(void);
74 extern void tick_set_periodic_handler(struct clock_event_device *dev, int broadcast);
75 extern int tick_broadcast_update_freq(struct clock_event_device *dev, u32 freq);
76 extern struct tick_device *tick_get_broadcast_device(void);
77 extern struct cpumask *tick_get_broadcast_mask(void);
78 extern const struct clock_event_device *tick_get_wakeup_device(int cpu);
79 # else /* !CONFIG_GENERIC_CLOCKEVENTS_BROADCAST: */
tick_install_broadcast_device(struct clock_event_device * dev,int cpu)80 static inline void tick_install_broadcast_device(struct clock_event_device *dev, int cpu) { }
tick_is_broadcast_device(struct clock_event_device * dev)81 static inline int tick_is_broadcast_device(struct clock_event_device *dev) { return 0; }
tick_device_uses_broadcast(struct clock_event_device * dev,int cpu)82 static inline int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu) { return 0; }
tick_do_periodic_broadcast(struct clock_event_device * d)83 static inline void tick_do_periodic_broadcast(struct clock_event_device *d) { }
tick_suspend_broadcast(void)84 static inline void tick_suspend_broadcast(void) { }
tick_resume_broadcast(void)85 static inline void tick_resume_broadcast(void) { }
tick_resume_check_broadcast(void)86 static inline bool tick_resume_check_broadcast(void) { return false; }
tick_broadcast_init(void)87 static inline void tick_broadcast_init(void) { }
tick_broadcast_update_freq(struct clock_event_device * dev,u32 freq)88 static 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 */
tick_set_periodic_handler(struct clock_event_device * dev,int broadcast)91 static 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: */
tick_suspend(void)98 static inline void tick_suspend(void) { }
tick_resume(void)99 static inline void tick_resume(void) { }
100 #endif /* !GENERIC_CLOCKEVENTS */
101 
102 /* Oneshot related functions */
103 #ifdef CONFIG_TICK_ONESHOT
104 extern void tick_setup_oneshot(struct clock_event_device *newdev,
105 			       void (*handler)(struct clock_event_device *),
106 			       ktime_t nextevt);
107 extern int tick_program_event(ktime_t expires, int force);
108 extern void tick_oneshot_notify(void);
109 extern int tick_switch_to_oneshot(void (*handler)(struct clock_event_device *));
110 extern void tick_resume_oneshot(void);
tick_oneshot_possible(void)111 static inline bool tick_oneshot_possible(void) { return true; }
112 extern int tick_oneshot_mode_active(void);
113 extern void tick_clock_notify(void);
114 extern int tick_check_oneshot_change(int allow_nohz);
115 extern int tick_init_highres(void);
116 #else /* !CONFIG_TICK_ONESHOT: */
117 static inline
tick_setup_oneshot(struct clock_event_device * newdev,void (* handler)(struct clock_event_device *),ktime_t nextevt)118 void tick_setup_oneshot(struct clock_event_device *newdev,
119 			void (*handler)(struct clock_event_device *),
120 			ktime_t nextevt) { BUG(); }
tick_resume_oneshot(void)121 static inline void tick_resume_oneshot(void) { BUG(); }
tick_program_event(ktime_t expires,int force)122 static inline int tick_program_event(ktime_t expires, int force) { return 0; }
tick_oneshot_notify(void)123 static inline void tick_oneshot_notify(void) { }
tick_oneshot_possible(void)124 static inline bool tick_oneshot_possible(void) { return false; }
tick_oneshot_mode_active(void)125 static inline int tick_oneshot_mode_active(void) { return 0; }
tick_clock_notify(void)126 static inline void tick_clock_notify(void) { }
tick_check_oneshot_change(int allow_nohz)127 static 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)
132 extern void tick_broadcast_switch_to_oneshot(void);
133 extern int tick_broadcast_oneshot_active(void);
134 extern void tick_check_oneshot_broadcast_this_cpu(void);
135 bool tick_broadcast_oneshot_available(void);
136 extern struct cpumask *tick_get_broadcast_oneshot_mask(void);
137 #else /* !(BROADCAST && ONESHOT): */
tick_broadcast_switch_to_oneshot(void)138 static inline void tick_broadcast_switch_to_oneshot(void) { }
tick_broadcast_oneshot_active(void)139 static inline int tick_broadcast_oneshot_active(void) { return 0; }
tick_check_oneshot_broadcast_this_cpu(void)140 static inline void tick_check_oneshot_broadcast_this_cpu(void) { }
tick_broadcast_oneshot_available(void)141 static 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)
145 extern void tick_offline_cpu(unsigned int cpu);
146 extern void tick_broadcast_offline(unsigned int cpu);
147 #else
tick_offline_cpu(unsigned int cpu)148 static inline void tick_offline_cpu(unsigned int cpu) { }
tick_broadcast_offline(unsigned int cpu)149 static inline void tick_broadcast_offline(unsigned int cpu) { }
150 #endif
151 
152 /* NO_HZ_FULL internal */
153 #ifdef CONFIG_NO_HZ_FULL
154 extern void tick_nohz_init(void);
155 # else
tick_nohz_init(void)156 static inline void tick_nohz_init(void) { }
157 #endif
158 
159 #ifdef CONFIG_NO_HZ_COMMON
160 extern unsigned long tick_nohz_active;
161 extern void timers_update_nohz(void);
162 extern u64 get_jiffies_update(unsigned long *basej);
163 # ifdef CONFIG_SMP
164 extern struct static_key_false timers_migration_enabled;
165 extern void fetch_next_timer_interrupt_remote(unsigned long basej, u64 basem,
166 					      struct timer_events *tevt,
167 					      unsigned int cpu);
168 extern void timer_lock_remote_bases(unsigned int cpu);
169 extern void timer_unlock_remote_bases(unsigned int cpu);
170 extern bool timer_base_is_idle(void);
171 extern void timer_expire_remote(unsigned int cpu);
172 # endif
173 #else /* CONFIG_NO_HZ_COMMON */
timers_update_nohz(void)174 static inline void timers_update_nohz(void) { }
175 #define tick_nohz_active (0)
176 #endif
177 
178 DECLARE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases);
179 
180 extern u64 get_next_timer_interrupt(unsigned long basej, u64 basem);
181 u64 timer_base_try_to_set_idle(unsigned long basej, u64 basem, bool *idle);
182 void 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 
191 void clock_was_set(unsigned int bases);
192 void clock_was_set_delayed(void);
193 
194 void 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 
216 extern ssize_t sysfs_get_uname(const char *buf, char *dst, size_t cnt);
217