linux-stable-mirror/include/linux/timekeeping.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_TIMEKEEPING_H
#define _LINUX_TIMEKEEPING_H

#include <linux/errno.h>
#include <linux/clocksource_ids.h>
#include <linux/ktime.h>

/* Included from linux/ktime.h */

void timekeeping_init(void);
extern int timekeeping_suspended;

/* Architecture timer tick functions: */
extern void legacy_timer_tick(unsigned long ticks);

/*
 * Get and set timeofday
 */
extern int do_settimeofday64(const struct timespec64 *ts);
extern int do_sys_settimeofday64(const struct timespec64 *tv,
				 const struct timezone *tz);

/*
 * ktime_get() family - read the current time in a multitude of ways.
 *
 * The default time reference is CLOCK_MONOTONIC, starting at
 * boot time but not counting the time spent in suspend.
 * For other references, use the functions with "real", "clocktai",
 * "boottime" and "raw" suffixes.
 *
 * To get the time in a different format, use the ones with
 * "ns", "ts64" and "seconds" suffix.
 *
 * See Documentation/core-api/timekeeping.rst for more details.
 */


/*
 * timespec64 based interfaces
 */
extern void ktime_get_raw_ts64(struct timespec64 *ts);
extern void ktime_get_ts64(struct timespec64 *ts);
extern void ktime_get_real_ts64(struct timespec64 *tv);
extern void ktime_get_coarse_ts64(struct timespec64 *ts);
extern void ktime_get_coarse_real_ts64(struct timespec64 *ts);

/* Multigrain timestamp interfaces */
extern void ktime_get_coarse_real_ts64_mg(struct timespec64 *ts);
extern void ktime_get_real_ts64_mg(struct timespec64 *ts);
extern unsigned long timekeeping_get_mg_floor_swaps(void);

void getboottime64(struct timespec64 *ts);

/*
 * time64_t base interfaces
 */
extern time64_t ktime_get_seconds(void);
extern time64_t __ktime_get_real_seconds(void);
extern time64_t ktime_get_real_seconds(void);

/*
 * ktime_t based interfaces
 */

enum tk_offsets {
	TK_OFFS_REAL,
	TK_OFFS_BOOT,
	TK_OFFS_TAI,
	TK_OFFS_MAX,
};

extern ktime_t ktime_get(void);
extern ktime_t ktime_get_with_offset(enum tk_offsets offs);
extern ktime_t ktime_get_coarse_with_offset(enum tk_offsets offs);
extern ktime_t ktime_mono_to_any(ktime_t tmono, enum tk_offsets offs);
extern ktime_t ktime_get_raw(void);
extern u32 ktime_get_resolution_ns(void);

/**
 * ktime_get_real - get the real (wall-) time in ktime_t format
 *
 * Returns: real (wall) time in ktime_t format
 */
static inline ktime_t ktime_get_real(void)
{
	return ktime_get_with_offset(TK_OFFS_REAL);
}

static inline ktime_t ktime_get_coarse_real(void)
{
	return ktime_get_coarse_with_offset(TK_OFFS_REAL);
}

/**
 * ktime_get_boottime - Get monotonic time since boot in ktime_t format
 *
 * This is similar to CLOCK_MONTONIC/ktime_get, but also includes the
 * time spent in suspend.
 *
 * Returns: monotonic time since boot in ktime_t format
 */
static inline ktime_t ktime_get_boottime(void)
{
	return ktime_get_with_offset(TK_OFFS_BOOT);
}

static inline ktime_t ktime_get_coarse_boottime(void)
{
	return ktime_get_coarse_with_offset(TK_OFFS_BOOT);
}

/**
 * ktime_get_clocktai - Get the TAI time of day in ktime_t format
 *
 * Returns: the TAI time of day in ktime_t format
 */
static inline ktime_t ktime_get_clocktai(void)
{
	return ktime_get_with_offset(TK_OFFS_TAI);
}

static inline ktime_t ktime_get_coarse_clocktai(void)
{
	return ktime_get_coarse_with_offset(TK_OFFS_TAI);
}

static inline ktime_t ktime_get_coarse(void)
{
	struct timespec64 ts;

	ktime_get_coarse_ts64(&ts);
	return timespec64_to_ktime(ts);
}

static inline u64 ktime_get_coarse_ns(void)
{
	return ktime_to_ns(ktime_get_coarse());
}

static inline u64 ktime_get_coarse_real_ns(void)
{
	return ktime_to_ns(ktime_get_coarse_real());
}

static inline u64 ktime_get_coarse_boottime_ns(void)
{
	return ktime_to_ns(ktime_get_coarse_boottime());
}

static inline u64 ktime_get_coarse_clocktai_ns(void)
{
	return ktime_to_ns(ktime_get_coarse_clocktai());
}

/**
 * ktime_mono_to_real - Convert monotonic time to clock realtime
 * @mono: monotonic time to convert
 *
 * Returns: time converted to realtime clock
 */
static inline ktime_t ktime_mono_to_real(ktime_t mono)
{
	return ktime_mono_to_any(mono, TK_OFFS_REAL);
}

/**
 * ktime_get_ns - Get the current time in nanoseconds
 *
 * Returns: current time converted to nanoseconds
 */
static inline u64 ktime_get_ns(void)
{
	return ktime_to_ns(ktime_get());
}

/**
 * ktime_get_real_ns - Get the current real/wall time in nanoseconds
 *
 * Returns: current real time converted to nanoseconds
 */
static inline u64 ktime_get_real_ns(void)
{
	return ktime_to_ns(ktime_get_real());
}

/**
 * ktime_get_boottime_ns - Get the monotonic time since boot in nanoseconds
 *
 * Returns: current boottime converted to nanoseconds
 */
static inline u64 ktime_get_boottime_ns(void)
{
	return ktime_to_ns(ktime_get_boottime());
}

/**
 * ktime_get_clocktai_ns - Get the current TAI time of day in nanoseconds
 *
 * Returns: current TAI time converted to nanoseconds
 */
static inline u64 ktime_get_clocktai_ns(void)
{
	return ktime_to_ns(ktime_get_clocktai());
}

/**
 * ktime_get_raw_ns - Get the raw monotonic time in nanoseconds
 *
 * Returns: current raw monotonic time converted to nanoseconds
 */
static inline u64 ktime_get_raw_ns(void)
{
	return ktime_to_ns(ktime_get_raw());
}

extern u64 ktime_get_mono_fast_ns(void);
extern u64 ktime_get_raw_fast_ns(void);
extern u64 ktime_get_boot_fast_ns(void);
extern u64 ktime_get_tai_fast_ns(void);
extern u64 ktime_get_real_fast_ns(void);

/*
 * timespec64/time64_t interfaces utilizing the ktime based ones
 * for API completeness, these could be implemented more efficiently
 * if needed.
 */
static inline void ktime_get_boottime_ts64(struct timespec64 *ts)
{
	*ts = ktime_to_timespec64(ktime_get_boottime());
}

static inline void ktime_get_coarse_boottime_ts64(struct timespec64 *ts)
{
	*ts = ktime_to_timespec64(ktime_get_coarse_boottime());
}

static inline time64_t ktime_get_boottime_seconds(void)
{
	return ktime_divns(ktime_get_coarse_boottime(), NSEC_PER_SEC);
}

static inline void ktime_get_clocktai_ts64(struct timespec64 *ts)
{
	*ts = ktime_to_timespec64(ktime_get_clocktai());
}

static inline void ktime_get_coarse_clocktai_ts64(struct timespec64 *ts)
{
	*ts = ktime_to_timespec64(ktime_get_coarse_clocktai());
}

static inline time64_t ktime_get_clocktai_seconds(void)
{
	return ktime_divns(ktime_get_coarse_clocktai(), NSEC_PER_SEC);
}

/*
 * RTC specific
 */
extern bool timekeeping_rtc_skipsuspend(void);
extern bool timekeeping_rtc_skipresume(void);

extern void timekeeping_inject_sleeptime64(const struct timespec64 *delta);

/*
 * Auxiliary clock interfaces
 */
#ifdef CONFIG_POSIX_AUX_CLOCKS
extern bool __must_check ktime_get_aux(clockid_t id, ktime_t *kt);
extern bool __must_check ktime_get_aux_ts64(clockid_t id, struct timespec64 *kt);
#else
static inline bool __must_check ktime_get_aux(clockid_t id, ktime_t *kt) { return false; }
static inline bool __must_check ktime_get_aux_ts64(clockid_t id, struct timespec64 *kt)
{
	return false;
}
#endif

/**
 * struct system_time_snapshot - Simultaneous time capture of monotonic raw time,
 *				 a selected CLOCK_* and the clocksource counter value
 * @cycles:		Clocksource counter value to produce the system times
 * @hw_cycles:		For derived clocksources, the hardware counter value from
 *			which @cycles was derived
 * @systime:		The system time of the selected CLOCK ID
 * @monoraw:		Monotonic raw system time
 * @cs_id:		Clocksource ID
 * @hw_csid:		Clocksource ID of the underlying hardware counter for derived
 *			clocksources which implement the read_snapshot() callback.
 * @clock_was_set_seq:	The sequence number of clock-was-set events
 * @cs_was_changed_seq:	The sequence number of clocksource change events
 * @valid:		True if the snapshot is valid
 *
 * @monoraw is CLOCK_MONOTONIC_RAW for system time CLOCK ids. For CLOCK_AUX$N
 * clock ids it's the monotonic raw time related to the AUX clock, which is
 * CLOCK_MONOTONIC_RAW plus a AUX clock specific offset.
 */
struct system_time_snapshot {
	u64			cycles;
	u64			hw_cycles;
	ktime_t			systime;
	ktime_t			monoraw;
	enum clocksource_ids	cs_id;
	enum clocksource_ids	hw_csid;
	u32			clock_was_set_seq;
	u8			cs_was_changed_seq;
	u8			valid;
};

/**
 * struct system_counterval_t - system counter value with the ID of the
 *				corresponding clocksource
 * @cycles:	System counter value
 * @cs_id:	Clocksource ID corresponding to system counter value. Used by
 *		timekeeping code to verify comparability of two cycle values.
 *		The default ID, CSID_GENERIC, does not identify a specific
 *		clocksource.
 * @use_nsecs:	@cycles is in nanoseconds.
 */
struct system_counterval_t {
	u64			cycles;
	enum clocksource_ids	cs_id;
	bool			use_nsecs;
};

/**
 * struct system_device_crosststamp - system/device cross-timestamp
 *				      (synchronized capture)
 * @clock_id:		System time Clock ID to capture
 * @device:		Device time
 * @sys_counter:	Clocksource counter value simultaneous with device time
 * @sys_systime:	System time for @clock_id
 * @sys_monoraw:	Monotonic raw simultaneous with device time
 *
 * @sys_monoraw is CLOCK_MONOTONIC_RAW for system time CLOCK ids. For
 * CLOCK_AUX$N clock ids it's the monotonic raw time related to the AUX clock,
 * which is CLOCK_MONOTONIC_RAW plus a AUX clock specific offset.
 */
struct system_device_crosststamp {
	clockid_t			clock_id;
	ktime_t				device;
	struct system_counterval_t	sys_counter;
	ktime_t				sys_systime;
	ktime_t				sys_monoraw;
};

extern bool ktime_real_to_base_clock(ktime_t treal,
				     enum clocksource_ids base_id, u64 *cycles);
extern bool timekeeping_clocksource_has_base(enum clocksource_ids id);

/*
 * Get cross timestamp between system clock and device clock
 */
extern int get_device_system_crosststamp(
			int (*get_time_fn)(ktime_t *device_time,
				struct system_counterval_t *system_counterval,
				void *ctx),
			void *ctx,
			struct system_time_snapshot *history,
			struct system_device_crosststamp *xtstamp);

/*
 * Simultaneously snapshot a given clock with MONOTONIC_RAW and the underlying
 * clocksource counter value.
 */
extern void ktime_get_snapshot_id(clockid_t clock_id, struct system_time_snapshot *systime_snapshot);

/*
 * Persistent clock related interfaces
 */
extern int persistent_clock_is_local;

extern void read_persistent_clock64(struct timespec64 *ts);
void read_persistent_wall_and_boot_offset(struct timespec64 *wall_clock,
					  struct timespec64 *boot_offset);
#ifdef CONFIG_GENERIC_CMOS_UPDATE
extern int update_persistent_clock64(struct timespec64 now);
#endif

#endif