xref: /openbmc/linux/include/linux/tick.h (revision 0d456bad)
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 
12 #ifdef CONFIG_GENERIC_CLOCKEVENTS
13 
14 enum tick_device_mode {
15 	TICKDEV_MODE_PERIODIC,
16 	TICKDEV_MODE_ONESHOT,
17 };
18 
19 struct tick_device {
20 	struct clock_event_device *evtdev;
21 	enum tick_device_mode mode;
22 };
23 
24 enum tick_nohz_mode {
25 	NOHZ_MODE_INACTIVE,
26 	NOHZ_MODE_LOWRES,
27 	NOHZ_MODE_HIGHRES,
28 };
29 
30 /**
31  * struct tick_sched - sched tick emulation and no idle tick control/stats
32  * @sched_timer:	hrtimer to schedule the periodic tick in high
33  *			resolution mode
34  * @last_tick:		Store the last tick expiry time when the tick
35  *			timer is modified for nohz sleeps. This is necessary
36  *			to resume the tick timer operation in the timeline
37  *			when the CPU returns from nohz sleep.
38  * @tick_stopped:	Indicator that the idle tick has been stopped
39  * @idle_jiffies:	jiffies at the entry to idle for idle time accounting
40  * @idle_calls:		Total number of idle calls
41  * @idle_sleeps:	Number of idle calls, where the sched tick was stopped
42  * @idle_entrytime:	Time when the idle call was entered
43  * @idle_waketime:	Time when the idle was interrupted
44  * @idle_exittime:	Time when the idle state was left
45  * @idle_sleeptime:	Sum of the time slept in idle with sched tick stopped
46  * @iowait_sleeptime:	Sum of the time slept in idle with sched tick stopped, with IO outstanding
47  * @sleep_length:	Duration of the current idle sleep
48  * @do_timer_lst:	CPU was the last one doing do_timer before going idle
49  */
50 struct tick_sched {
51 	struct hrtimer			sched_timer;
52 	unsigned long			check_clocks;
53 	enum tick_nohz_mode		nohz_mode;
54 	ktime_t				last_tick;
55 	int				inidle;
56 	int				tick_stopped;
57 	unsigned long			idle_jiffies;
58 	unsigned long			idle_calls;
59 	unsigned long			idle_sleeps;
60 	int				idle_active;
61 	ktime_t				idle_entrytime;
62 	ktime_t				idle_waketime;
63 	ktime_t				idle_exittime;
64 	ktime_t				idle_sleeptime;
65 	ktime_t				iowait_sleeptime;
66 	ktime_t				sleep_length;
67 	unsigned long			last_jiffies;
68 	unsigned long			next_jiffies;
69 	ktime_t				idle_expires;
70 	int				do_timer_last;
71 };
72 
73 extern void __init tick_init(void);
74 extern int tick_is_oneshot_available(void);
75 extern struct tick_device *tick_get_device(int cpu);
76 
77 # ifdef CONFIG_HIGH_RES_TIMERS
78 extern int tick_init_highres(void);
79 extern int tick_program_event(ktime_t expires, int force);
80 extern void tick_setup_sched_timer(void);
81 # endif
82 
83 # if defined CONFIG_NO_HZ || defined CONFIG_HIGH_RES_TIMERS
84 extern void tick_cancel_sched_timer(int cpu);
85 # else
86 static inline void tick_cancel_sched_timer(int cpu) { }
87 # endif
88 
89 # ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
90 extern struct tick_device *tick_get_broadcast_device(void);
91 extern struct cpumask *tick_get_broadcast_mask(void);
92 
93 #  ifdef CONFIG_TICK_ONESHOT
94 extern struct cpumask *tick_get_broadcast_oneshot_mask(void);
95 #  endif
96 
97 # endif /* BROADCAST */
98 
99 # ifdef CONFIG_TICK_ONESHOT
100 extern void tick_clock_notify(void);
101 extern int tick_check_oneshot_change(int allow_nohz);
102 extern struct tick_sched *tick_get_tick_sched(int cpu);
103 extern void tick_check_idle(int cpu);
104 extern int tick_oneshot_mode_active(void);
105 #  ifndef arch_needs_cpu
106 #   define arch_needs_cpu(cpu) (0)
107 #  endif
108 # else
109 static inline void tick_clock_notify(void) { }
110 static inline int tick_check_oneshot_change(int allow_nohz) { return 0; }
111 static inline void tick_check_idle(int cpu) { }
112 static inline int tick_oneshot_mode_active(void) { return 0; }
113 # endif
114 
115 #else /* CONFIG_GENERIC_CLOCKEVENTS */
116 static inline void tick_init(void) { }
117 static inline void tick_cancel_sched_timer(int cpu) { }
118 static inline void tick_clock_notify(void) { }
119 static inline int tick_check_oneshot_change(int allow_nohz) { return 0; }
120 static inline void tick_check_idle(int cpu) { }
121 static inline int tick_oneshot_mode_active(void) { return 0; }
122 #endif /* !CONFIG_GENERIC_CLOCKEVENTS */
123 
124 # ifdef CONFIG_NO_HZ
125 extern void tick_nohz_idle_enter(void);
126 extern void tick_nohz_idle_exit(void);
127 extern void tick_nohz_irq_exit(void);
128 extern ktime_t tick_nohz_get_sleep_length(void);
129 extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time);
130 extern u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time);
131 # else
132 static inline void tick_nohz_idle_enter(void) { }
133 static inline void tick_nohz_idle_exit(void) { }
134 
135 static inline ktime_t tick_nohz_get_sleep_length(void)
136 {
137 	ktime_t len = { .tv64 = NSEC_PER_SEC/HZ };
138 
139 	return len;
140 }
141 static inline u64 get_cpu_idle_time_us(int cpu, u64 *unused) { return -1; }
142 static inline u64 get_cpu_iowait_time_us(int cpu, u64 *unused) { return -1; }
143 # endif /* !NO_HZ */
144 
145 # ifdef CONFIG_CPU_IDLE_GOV_MENU
146 extern void menu_hrtimer_cancel(void);
147 # else
148 static inline void menu_hrtimer_cancel(void) {}
149 # endif /* CONFIG_CPU_IDLE_GOV_MENU */
150 
151 #endif
152