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 | |