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 */
39 static inline int tick_device_is_functional(struct clock_event_device *dev)
40 {
41 return !(dev->features & CLOCK_EVT_FEAT_DUMMY);
42 }
43
44 static inline enum clock_event_state clockevent_get_state(struct clock_event_device *dev)
45 {
46 return dev->state_use_accessors;
47 }
48
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: */
80 static inline void tick_install_broadcast_device(struct clock_event_device *dev, int cpu) { }
81 static inline int tick_is_broadcast_device(struct clock_event_device *dev) { return 0; }
82 static inline int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu) { return 0; }
83 static inline void tick_do_periodic_broadcast(struct clock_event_device *d) { }
84 static inline void tick_suspend_broadcast(void) { }
85 static inline void tick_resume_broadcast(void) { }
86 static inline bool tick_resume_check_broadcast(void) { return false; }
87 static inline void tick_broadcast_init(void) { }
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 */
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: */
98 static inline void tick_suspend(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);
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
118 void tick_setup_oneshot(struct clock_event_device *newdev,
119 void (*handler)(struct clock_event_device *),
120 ktime_t nextevt) { BUG(); }
121 static inline void tick_resume_oneshot(void) { BUG(); }
122 static inline int tick_program_event(ktime_t expires, int force) { return 0; }
123 static inline void tick_oneshot_notify(void) { }
124 static inline bool tick_oneshot_possible(void) { return false; }
125 static inline int tick_oneshot_mode_active(void) { return 0; }
126 static inline void tick_clock_notify(void) { }
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): */
138 static inline void tick_broadcast_switch_to_oneshot(void) { }
139 static inline int tick_broadcast_oneshot_active(void) { return 0; }
140 static inline void tick_check_oneshot_broadcast_this_cpu(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
148 static inline void tick_offline_cpu(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
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 */
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
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