[linux-block.git] / kernel / time / tick-sched.h

/* 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
Commit	Line	Data
	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