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 /* The CPU is in the tick idle mode */
18 #define TS_FLAG_INIDLE BIT(0)
19 /* The idle tick has been stopped */
20 #define TS_FLAG_STOPPED BIT(1)
21 /*
22 * Indicator that the CPU is actively in the tick idle mode;
23 * it is reset during irq handling phases.
24 */
25 #define TS_FLAG_IDLE_ACTIVE BIT(2)
26 /* CPU was the last one doing do_timer before going idle */
27 #define TS_FLAG_DO_TIMER_LAST BIT(3)
28 /* NO_HZ is enabled */
29 #define TS_FLAG_NOHZ BIT(4)
30 /* High resolution tick mode */
31 #define TS_FLAG_HIGHRES BIT(5)
32
33 /**
34 * struct tick_sched - sched tick emulation and no idle tick control/stats
35 *
36 * @flags: State flags gathering the TS_FLAG_* features
37 * @got_idle_tick: Tick timer function has run with @inidle set
38 * @stalled_jiffies: Number of stalled jiffies detected across ticks
39 * @last_tick_jiffies: Value of jiffies seen on last tick
40 * @sched_timer: hrtimer to schedule the periodic tick in high
41 * resolution mode
42 * @last_tick: Store the last tick expiry time when the tick
43 * timer is modified for nohz sleeps. This is necessary
44 * to resume the tick timer operation in the timeline
45 * when the CPU returns from nohz sleep.
46 * @next_tick: Next tick to be fired when in dynticks mode.
47 * @idle_jiffies: jiffies at the entry to idle for idle time accounting
48 * @idle_waketime: Time when the idle was interrupted
49 * @idle_sleeptime_seq: sequence counter for data consistency
50 * @idle_entrytime: Time when the idle call was entered
51 * @last_jiffies: Base jiffies snapshot when next event was last computed
52 * @timer_expires_base: Base time clock monotonic for @timer_expires
53 * @timer_expires: Anticipated timer expiration time (in case sched tick is stopped)
54 * @next_timer: Expiry time of next expiring timer for debugging purpose only
55 * @idle_expires: Next tick in idle, for debugging purpose only
56 * @idle_calls: Total number of idle calls
57 * @idle_sleeps: Number of idle calls, where the sched tick was stopped
58 * @idle_exittime: Time when the idle state was left
59 * @idle_sleeptime: Sum of the time slept in idle with sched tick stopped
60 * @iowait_sleeptime: Sum of the time slept in idle with sched tick stopped, with IO outstanding
61 * @tick_dep_mask: Tick dependency mask - is set, if someone needs the tick
62 * @check_clocks: Notification mechanism about clocksource changes
63 */
64 struct tick_sched {
65 /* Common flags */
66 unsigned long flags;
67
68 /* Tick handling: jiffies stall check */
69 unsigned int stalled_jiffies;
70 unsigned long last_tick_jiffies;
71
72 /* Tick handling */
73 struct hrtimer sched_timer;
74 ktime_t last_tick;
75 ktime_t next_tick;
76 unsigned long idle_jiffies;
77 ktime_t idle_waketime;
78 unsigned int got_idle_tick;
79
80 /* Idle entry */
81 seqcount_t idle_sleeptime_seq;
82 ktime_t idle_entrytime;
83
84 /* Tick stop */
85 unsigned long last_jiffies;
86 u64 timer_expires_base;
87 u64 timer_expires;
88 u64 next_timer;
89 ktime_t idle_expires;
90 unsigned long idle_calls;
91 unsigned long idle_sleeps;
92
93 /* Idle exit */
94 ktime_t idle_exittime;
95 ktime_t idle_sleeptime;
96 ktime_t iowait_sleeptime;
97
98 /* Full dynticks handling */
99 atomic_t tick_dep_mask;
100
101 /* Clocksource changes */
102 unsigned long check_clocks;
103 };
104
105 extern struct tick_sched *tick_get_tick_sched(int cpu);
106
107 extern void tick_setup_sched_timer(bool hrtimer);
108 #if defined CONFIG_TICK_ONESHOT
109 extern void tick_sched_timer_dying(int cpu);
110 #else
111 static inline void tick_sched_timer_dying(int cpu) { }
112 #endif
113
114 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
115 extern int __tick_broadcast_oneshot_control(enum tick_broadcast_state state);
116 #else
117 static inline int
118 __tick_broadcast_oneshot_control(enum tick_broadcast_state state)
119 {
120 return -EBUSY;
121 }
122 #endif
123
124 #endif
125
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