xref: /openbmc/linux/kernel/time/tick-sched.h (revision 8cb5d748)
1 #ifndef _TICK_SCHED_H
2 #define _TICK_SCHED_H
3 
4 #include <linux/hrtimer.h>
5 
6 enum tick_device_mode {
7 	TICKDEV_MODE_PERIODIC,
8 	TICKDEV_MODE_ONESHOT,
9 };
10 
11 struct tick_device {
12 	struct clock_event_device *evtdev;
13 	enum tick_device_mode mode;
14 };
15 
16 enum tick_nohz_mode {
17 	NOHZ_MODE_INACTIVE,
18 	NOHZ_MODE_LOWRES,
19 	NOHZ_MODE_HIGHRES,
20 };
21 
22 /**
23  * struct tick_sched - sched tick emulation and no idle tick control/stats
24  * @sched_timer:	hrtimer to schedule the periodic tick in high
25  *			resolution mode
26  * @last_tick:		Store the last tick expiry time when the tick
27  *			timer is modified for nohz sleeps. This is necessary
28  *			to resume the tick timer operation in the timeline
29  *			when the CPU returns from nohz sleep.
30  * @next_tick:		Next tick to be fired when in dynticks mode.
31  * @tick_stopped:	Indicator that the idle tick has been stopped
32  * @idle_jiffies:	jiffies at the entry to idle for idle time accounting
33  * @idle_calls:		Total number of idle calls
34  * @idle_sleeps:	Number of idle calls, where the sched tick was stopped
35  * @idle_entrytime:	Time when the idle call was entered
36  * @idle_waketime:	Time when the idle was interrupted
37  * @idle_exittime:	Time when the idle state was left
38  * @idle_sleeptime:	Sum of the time slept in idle with sched tick stopped
39  * @iowait_sleeptime:	Sum of the time slept in idle with sched tick stopped, with IO outstanding
40  * @sleep_length:	Duration of the current idle sleep
41  * @do_timer_lst:	CPU was the last one doing do_timer before going idle
42  */
43 struct tick_sched {
44 	struct hrtimer			sched_timer;
45 	unsigned long			check_clocks;
46 	enum tick_nohz_mode		nohz_mode;
47 	ktime_t				last_tick;
48 	ktime_t				next_tick;
49 	int				inidle;
50 	int				tick_stopped;
51 	unsigned long			idle_jiffies;
52 	unsigned long			idle_calls;
53 	unsigned long			idle_sleeps;
54 	int				idle_active;
55 	ktime_t				idle_entrytime;
56 	ktime_t				idle_waketime;
57 	ktime_t				idle_exittime;
58 	ktime_t				idle_sleeptime;
59 	ktime_t				iowait_sleeptime;
60 	ktime_t				sleep_length;
61 	unsigned long			last_jiffies;
62 	u64				next_timer;
63 	ktime_t				idle_expires;
64 	int				do_timer_last;
65 	atomic_t			tick_dep_mask;
66 };
67 
68 extern struct tick_sched *tick_get_tick_sched(int cpu);
69 
70 extern void tick_setup_sched_timer(void);
71 #if defined CONFIG_NO_HZ_COMMON || defined CONFIG_HIGH_RES_TIMERS
72 extern void tick_cancel_sched_timer(int cpu);
73 #else
74 static inline void tick_cancel_sched_timer(int cpu) { }
75 #endif
76 
77 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
78 extern int __tick_broadcast_oneshot_control(enum tick_broadcast_state state);
79 #else
80 static inline int
81 __tick_broadcast_oneshot_control(enum tick_broadcast_state state)
82 {
83 	return -EBUSY;
84 }
85 #endif
86 
87 #endif
88