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tick.h
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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 
50 struct tick_sched {
51  struct hrtimer sched_timer;
52  unsigned long check_clocks;
53  enum tick_nohz_mode nohz_mode;
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 #endif