diff options
Diffstat (limited to 'kernel/time/tick-sched.h')
| -rw-r--r-- | kernel/time/tick-sched.h | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/kernel/time/tick-sched.h b/kernel/time/tick-sched.h new file mode 100644 index 000000000000..b4a7822f495d --- /dev/null +++ b/kernel/time/tick-sched.h @@ -0,0 +1,124 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _TICK_SCHED_H +#define _TICK_SCHED_H + +#include <linux/hrtimer.h> + +enum tick_device_mode { + TICKDEV_MODE_PERIODIC, + TICKDEV_MODE_ONESHOT, +}; + +struct tick_device { + struct clock_event_device *evtdev; + enum tick_device_mode mode; +}; + +/* The CPU is in the tick idle mode */ +#define TS_FLAG_INIDLE BIT(0) +/* The idle tick has been stopped */ +#define TS_FLAG_STOPPED BIT(1) +/* + * Indicator that the CPU is actively in the tick idle mode; + * it is reset during irq handling phases. + */ +#define TS_FLAG_IDLE_ACTIVE BIT(2) +/* CPU was the last one doing do_timer before going idle */ +#define TS_FLAG_DO_TIMER_LAST BIT(3) +/* NO_HZ is enabled */ +#define TS_FLAG_NOHZ BIT(4) +/* High resolution tick mode */ +#define TS_FLAG_HIGHRES BIT(5) + +/** + * struct tick_sched - sched tick emulation and no idle tick control/stats + * + * @flags: State flags gathering the TS_FLAG_* features + * @got_idle_tick: Tick timer function has run with @inidle set + * @stalled_jiffies: Number of stalled jiffies detected across ticks + * @last_tick_jiffies: Value of jiffies seen on last tick + * @sched_timer: hrtimer to schedule the periodic tick in high + * resolution mode + * @last_tick: Store the last tick expiry time when the tick + * timer is modified for nohz sleeps. This is necessary + * to resume the tick timer operation in the timeline + * when the CPU returns from nohz sleep. + * @next_tick: Next tick to be fired when in dynticks mode. + * @idle_jiffies: jiffies at the entry to idle for idle time accounting + * @idle_waketime: Time when the idle was interrupted + * @idle_sleeptime_seq: sequence counter for data consistency + * @idle_entrytime: Time when the idle call was entered + * @last_jiffies: Base jiffies snapshot when next event was last computed + * @timer_expires_base: Base time clock monotonic for @timer_expires + * @timer_expires: Anticipated timer expiration time (in case sched tick is stopped) + * @next_timer: Expiry time of next expiring timer for debugging purpose only + * @idle_expires: Next tick in idle, for debugging purpose only + * @idle_calls: Total number of idle calls + * @idle_sleeps: Number of idle calls, where the sched tick was stopped + * @idle_exittime: Time when the idle state was left + * @idle_sleeptime: Sum of the time slept in idle with sched tick stopped + * @iowait_sleeptime: Sum of the time slept in idle with sched tick stopped, with IO outstanding + * @tick_dep_mask: Tick dependency mask - is set, if someone needs the tick + * @check_clocks: Notification mechanism about clocksource changes + */ +struct tick_sched { + /* Common flags */ + unsigned long flags; + + /* Tick handling: jiffies stall check */ + unsigned int stalled_jiffies; + unsigned long last_tick_jiffies; + + /* Tick handling */ + struct hrtimer sched_timer; + ktime_t last_tick; + ktime_t next_tick; + unsigned long idle_jiffies; + ktime_t idle_waketime; + unsigned int got_idle_tick; + + /* Idle entry */ + seqcount_t idle_sleeptime_seq; + ktime_t idle_entrytime; + + /* Tick stop */ + unsigned long last_jiffies; + u64 timer_expires_base; + u64 timer_expires; + u64 next_timer; + ktime_t idle_expires; + unsigned long idle_calls; + unsigned long idle_sleeps; + + /* Idle exit */ + ktime_t idle_exittime; + ktime_t idle_sleeptime; + ktime_t iowait_sleeptime; + + /* Full dynticks handling */ + atomic_t tick_dep_mask; + + /* Clocksource changes */ + unsigned long check_clocks; +}; + +extern struct tick_sched *tick_get_tick_sched(int cpu); + +extern void tick_setup_sched_timer(bool hrtimer); +#if defined CONFIG_TICK_ONESHOT +extern void tick_sched_timer_dying(int cpu); +#else +static inline void tick_sched_timer_dying(int cpu) { } +#endif + +#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST +extern int __tick_broadcast_oneshot_control(enum tick_broadcast_state state); +#else +static inline int +__tick_broadcast_oneshot_control(enum tick_broadcast_state state) +{ + return -EBUSY; +} +#endif + +#endif |