xref: /openbmc/linux/include/linux/tick.h (revision b34e08d5)
1 /*  linux/include/linux/tick.h
2  *
3  *  This file contains the structure definitions for tick related functions
4  *
5  */
6 #ifndef _LINUX_TICK_H
7 #define _LINUX_TICK_H
8 
9 #include <linux/clockchips.h>
10 #include <linux/irqflags.h>
11 #include <linux/percpu.h>
12 #include <linux/hrtimer.h>
13 #include <linux/context_tracking_state.h>
14 #include <linux/cpumask.h>
15 
16 #ifdef CONFIG_GENERIC_CLOCKEVENTS
17 
18 enum tick_device_mode {
19 	TICKDEV_MODE_PERIODIC,
20 	TICKDEV_MODE_ONESHOT,
21 };
22 
23 struct tick_device {
24 	struct clock_event_device *evtdev;
25 	enum tick_device_mode mode;
26 };
27 
28 enum tick_nohz_mode {
29 	NOHZ_MODE_INACTIVE,
30 	NOHZ_MODE_LOWRES,
31 	NOHZ_MODE_HIGHRES,
32 };
33 
34 /**
35  * struct tick_sched - sched tick emulation and no idle tick control/stats
36  * @sched_timer:	hrtimer to schedule the periodic tick in high
37  *			resolution mode
38  * @last_tick:		Store the last tick expiry time when the tick
39  *			timer is modified for nohz sleeps. This is necessary
40  *			to resume the tick timer operation in the timeline
41  *			when the CPU returns from nohz sleep.
42  * @tick_stopped:	Indicator that the idle tick has been stopped
43  * @idle_jiffies:	jiffies at the entry to idle for idle time accounting
44  * @idle_calls:		Total number of idle calls
45  * @idle_sleeps:	Number of idle calls, where the sched tick was stopped
46  * @idle_entrytime:	Time when the idle call was entered
47  * @idle_waketime:	Time when the idle was interrupted
48  * @idle_exittime:	Time when the idle state was left
49  * @idle_sleeptime:	Sum of the time slept in idle with sched tick stopped
50  * @iowait_sleeptime:	Sum of the time slept in idle with sched tick stopped, with IO outstanding
51  * @sleep_length:	Duration of the current idle sleep
52  * @do_timer_lst:	CPU was the last one doing do_timer before going idle
53  */
54 struct tick_sched {
55 	struct hrtimer			sched_timer;
56 	unsigned long			check_clocks;
57 	enum tick_nohz_mode		nohz_mode;
58 	ktime_t				last_tick;
59 	int				inidle;
60 	int				tick_stopped;
61 	unsigned long			idle_jiffies;
62 	unsigned long			idle_calls;
63 	unsigned long			idle_sleeps;
64 	int				idle_active;
65 	ktime_t				idle_entrytime;
66 	ktime_t				idle_waketime;
67 	ktime_t				idle_exittime;
68 	ktime_t				idle_sleeptime;
69 	ktime_t				iowait_sleeptime;
70 	ktime_t				sleep_length;
71 	unsigned long			last_jiffies;
72 	unsigned long			next_jiffies;
73 	ktime_t				idle_expires;
74 	int				do_timer_last;
75 };
76 
77 extern void __init tick_init(void);
78 extern int tick_is_oneshot_available(void);
79 extern struct tick_device *tick_get_device(int cpu);
80 
81 # ifdef CONFIG_HIGH_RES_TIMERS
82 extern int tick_init_highres(void);
83 extern int tick_program_event(ktime_t expires, int force);
84 extern void tick_setup_sched_timer(void);
85 # endif
86 
87 # if defined CONFIG_NO_HZ_COMMON || defined CONFIG_HIGH_RES_TIMERS
88 extern void tick_cancel_sched_timer(int cpu);
89 # else
90 static inline void tick_cancel_sched_timer(int cpu) { }
91 # endif
92 
93 # ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
94 extern struct tick_device *tick_get_broadcast_device(void);
95 extern struct cpumask *tick_get_broadcast_mask(void);
96 
97 #  ifdef CONFIG_TICK_ONESHOT
98 extern struct cpumask *tick_get_broadcast_oneshot_mask(void);
99 #  endif
100 
101 # endif /* BROADCAST */
102 
103 # ifdef CONFIG_TICK_ONESHOT
104 extern void tick_clock_notify(void);
105 extern int tick_check_oneshot_change(int allow_nohz);
106 extern struct tick_sched *tick_get_tick_sched(int cpu);
107 extern void tick_irq_enter(void);
108 extern int tick_oneshot_mode_active(void);
109 #  ifndef arch_needs_cpu
110 #   define arch_needs_cpu(cpu) (0)
111 #  endif
112 # else
113 static inline void tick_clock_notify(void) { }
114 static inline int tick_check_oneshot_change(int allow_nohz) { return 0; }
115 static inline void tick_irq_enter(void) { }
116 static inline int tick_oneshot_mode_active(void) { return 0; }
117 # endif
118 
119 #else /* CONFIG_GENERIC_CLOCKEVENTS */
120 static inline void tick_init(void) { }
121 static inline void tick_cancel_sched_timer(int cpu) { }
122 static inline void tick_clock_notify(void) { }
123 static inline int tick_check_oneshot_change(int allow_nohz) { return 0; }
124 static inline void tick_irq_enter(void) { }
125 static inline int tick_oneshot_mode_active(void) { return 0; }
126 #endif /* !CONFIG_GENERIC_CLOCKEVENTS */
127 
128 # ifdef CONFIG_NO_HZ_COMMON
129 DECLARE_PER_CPU(struct tick_sched, tick_cpu_sched);
130 
131 static inline int tick_nohz_tick_stopped(void)
132 {
133 	return __this_cpu_read(tick_cpu_sched.tick_stopped);
134 }
135 
136 extern void tick_nohz_idle_enter(void);
137 extern void tick_nohz_idle_exit(void);
138 extern void tick_nohz_irq_exit(void);
139 extern ktime_t tick_nohz_get_sleep_length(void);
140 extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time);
141 extern u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time);
142 
143 # else /* !CONFIG_NO_HZ_COMMON */
144 static inline int tick_nohz_tick_stopped(void)
145 {
146 	return 0;
147 }
148 
149 static inline void tick_nohz_idle_enter(void) { }
150 static inline void tick_nohz_idle_exit(void) { }
151 
152 static inline ktime_t tick_nohz_get_sleep_length(void)
153 {
154 	ktime_t len = { .tv64 = NSEC_PER_SEC/HZ };
155 
156 	return len;
157 }
158 static inline u64 get_cpu_idle_time_us(int cpu, u64 *unused) { return -1; }
159 static inline u64 get_cpu_iowait_time_us(int cpu, u64 *unused) { return -1; }
160 # endif /* !CONFIG_NO_HZ_COMMON */
161 
162 #ifdef CONFIG_NO_HZ_FULL
163 extern bool tick_nohz_full_running;
164 extern cpumask_var_t tick_nohz_full_mask;
165 
166 static inline bool tick_nohz_full_enabled(void)
167 {
168 	if (!context_tracking_is_enabled())
169 		return false;
170 
171 	return tick_nohz_full_running;
172 }
173 
174 static inline bool tick_nohz_full_cpu(int cpu)
175 {
176 	if (!tick_nohz_full_enabled())
177 		return false;
178 
179 	return cpumask_test_cpu(cpu, tick_nohz_full_mask);
180 }
181 
182 extern void tick_nohz_init(void);
183 extern void __tick_nohz_full_check(void);
184 extern void tick_nohz_full_kick(void);
185 extern void tick_nohz_full_kick_all(void);
186 extern void __tick_nohz_task_switch(struct task_struct *tsk);
187 #else
188 static inline void tick_nohz_init(void) { }
189 static inline bool tick_nohz_full_enabled(void) { return false; }
190 static inline bool tick_nohz_full_cpu(int cpu) { return false; }
191 static inline void __tick_nohz_full_check(void) { }
192 static inline void tick_nohz_full_kick(void) { }
193 static inline void tick_nohz_full_kick_all(void) { }
194 static inline void __tick_nohz_task_switch(struct task_struct *tsk) { }
195 #endif
196 
197 static inline void tick_nohz_full_check(void)
198 {
199 	if (tick_nohz_full_enabled())
200 		__tick_nohz_full_check();
201 }
202 
203 static inline void tick_nohz_task_switch(struct task_struct *tsk)
204 {
205 	if (tick_nohz_full_enabled())
206 		__tick_nohz_task_switch(tsk);
207 }
208 
209 
210 #endif
211