xref: /openbmc/linux/kernel/time/tick-sched.h (revision 82e6fdd6)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _TICK_SCHED_H
3 #define _TICK_SCHED_H
4 
5 #include <linux/hrtimer.h>
6 
7 enum tick_device_mode {
8 	TICKDEV_MODE_PERIODIC,
9 	TICKDEV_MODE_ONESHOT,
10 };
11 
12 struct tick_device {
13 	struct clock_event_device *evtdev;
14 	enum tick_device_mode mode;
15 };
16 
17 enum tick_nohz_mode {
18 	NOHZ_MODE_INACTIVE,
19 	NOHZ_MODE_LOWRES,
20 	NOHZ_MODE_HIGHRES,
21 };
22 
23 /**
24  * struct tick_sched - sched tick emulation and no idle tick control/stats
25  * @sched_timer:	hrtimer to schedule the periodic tick in high
26  *			resolution mode
27  * @last_tick:		Store the last tick expiry time when the tick
28  *			timer is modified for nohz sleeps. This is necessary
29  *			to resume the tick timer operation in the timeline
30  *			when the CPU returns from nohz sleep.
31  * @next_tick:		Next tick to be fired when in dynticks mode.
32  * @tick_stopped:	Indicator that the idle tick has been stopped
33  * @idle_jiffies:	jiffies at the entry to idle for idle time accounting
34  * @idle_calls:		Total number of idle calls
35  * @idle_sleeps:	Number of idle calls, where the sched tick was stopped
36  * @idle_entrytime:	Time when the idle call was entered
37  * @idle_waketime:	Time when the idle was interrupted
38  * @idle_exittime:	Time when the idle state was left
39  * @idle_sleeptime:	Sum of the time slept in idle with sched tick stopped
40  * @iowait_sleeptime:	Sum of the time slept in idle with sched tick stopped, with IO outstanding
41  * @sleep_length:	Duration of the current idle sleep
42  * @do_timer_lst:	CPU was the last one doing do_timer before going idle
43  */
44 struct tick_sched {
45 	struct hrtimer			sched_timer;
46 	unsigned long			check_clocks;
47 	enum tick_nohz_mode		nohz_mode;
48 	ktime_t				last_tick;
49 	ktime_t				next_tick;
50 	int				inidle;
51 	int				tick_stopped;
52 	unsigned long			idle_jiffies;
53 	unsigned long			idle_calls;
54 	unsigned long			idle_sleeps;
55 	int				idle_active;
56 	ktime_t				idle_entrytime;
57 	ktime_t				idle_waketime;
58 	ktime_t				idle_exittime;
59 	ktime_t				idle_sleeptime;
60 	ktime_t				iowait_sleeptime;
61 	ktime_t				sleep_length;
62 	unsigned long			last_jiffies;
63 	u64				next_timer;
64 	ktime_t				idle_expires;
65 	int				do_timer_last;
66 	atomic_t			tick_dep_mask;
67 };
68 
69 extern struct tick_sched *tick_get_tick_sched(int cpu);
70 
71 extern void tick_setup_sched_timer(void);
72 #if defined CONFIG_NO_HZ_COMMON || defined CONFIG_HIGH_RES_TIMERS
73 extern void tick_cancel_sched_timer(int cpu);
74 #else
75 static inline void tick_cancel_sched_timer(int cpu) { }
76 #endif
77 
78 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
79 extern int __tick_broadcast_oneshot_control(enum tick_broadcast_state state);
80 #else
81 static inline int
82 __tick_broadcast_oneshot_control(enum tick_broadcast_state state)
83 {
84 	return -EBUSY;
85 }
86 #endif
87 
88 #endif
89