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