/*
* You SHOULD NOT be including this unless you're vsyscall
* handling code or timekeeping internal code!
*/
#ifndef _LINUX_TIMEKEEPER_INTERNAL_H
#define _LINUX_TIMEKEEPER_INTERNAL_H
#include <linux/clocksource.h>
#include <linux/jiffies.h>
#include <linux/time.h>
/**
* struct tk_read_base - base structure for timekeeping readout
* @clock: Current clocksource used for timekeeping.
* @read: Read function of @clock
* @mask: Bitmask for two's complement subtraction of non 64bit clocks
* @cycle_last: @clock cycle value at last update
* @mult: NTP adjusted multiplier for scaled math conversion
* @shift: Shift value for scaled math conversion
* @xtime_nsec: Shifted (fractional) nano seconds offset for readout
* @base_mono: ktime_t (nanoseconds) base time for readout
*
* This struct has size 56 byte on 64 bit. Together with a seqcount it
* occupies a single 64byte cache line.
*
* The struct is separate from struct timekeeper as it is also used
* for a fast NMI safe accessor to clock monotonic.
*/
struct tk_read_base {
struct clocksource *clock;
cycle_t (*read)(struct clocksource *cs);
cycle_t mask;
cycle_t cycle_last;
u32 mult;
u32 shift;
u64 xtime_nsec;
ktime_t base_mono;
};
/**
* struct timekeeper - Structure holding internal timekeeping values.
* @tkr: The readout base structure
* @xtime_sec: Current CLOCK_REALTIME time in seconds
* @wall_to_monotonic: CLOCK_REALTIME to CLOCK_MONOTONIC offset
* @offs_real: Offset clock monotonic -> clock realtime
* @offs_boot: Offset clock monotonic -> clock boottime
* @offs_tai: Offset clock monotonic -> clock tai
* @tai_offset: The current UTC to TAI offset in seconds
* @base_raw: Monotonic raw base time in ktime_t format
* @raw_time: Monotonic raw base time in timespec64 format
* @cycle_interval: Number of clock cycles in one NTP interval
* @xtime_interval: Number of clock shifted nano seconds in one NTP
* interval.
* @xtime_remainder: Shifted nano seconds left over when rounding
* @cycle_interval
* @raw_interval: Raw nano seconds accumulated per NTP interval.
* @ntp_error: Difference between accumulated time and NTP time in ntp
* shifted nano seconds.
* @ntp_error_shift: Shift conversion between clock shifted nano seconds and
* ntp shifted nano seconds.
*
* Note: For timespec(64) based interfaces wall_to_monotonic is what
* we need to add to xtime (or xtime corrected for sub jiffie times)
* to get to monotonic time. Monotonic is pegged at zero at system
* boot time, so wall_to_monotonic will be negative, however, we will
* ALWAYS keep the tv_nsec part positive so we can use the usual
* normalization.
*
* wall_to_monotonic is moved after resume from suspend for the
* monotonic time not to jump. We need to add total_sleep_time to
* wall_to_monotonic to get the real boot based time offset.
*
* wall_to_monotonic is no longer the boot time, getboottime must be
* used instead.
*/
struct timekeeper {
struct tk_read_base tkr;
u64 xtime_sec;
struct timespec64 wall_to_monotonic;
ktime_t offs_real;
ktime_t offs_boot;
ktime_t offs_tai;
s32 tai_offset;
ktime_t base_raw;
struct timespec64 raw_time;
/* The following members are for timekeeping internal use */
cycle_t cycle_interval;
u64 xtime_interval;
s64 xtime_remainder;
u32 raw_interval;
/* The ntp_tick_length() value currently being used.
* This cached copy ensures we consistently apply the tick
* length for an entire tick, as ntp_tick_length may change
* mid-tick, and we don't want to apply that new value to
* the tick in progress.
*/
u64 ntp_tick;
/* Difference between accumulated time and NTP time in ntp
* shifted nano seconds. */
s64 ntp_error;
u32 ntp_error_shift;
u32 ntp_err_mult;
};
#ifdef CONFIG_GENERIC_TIME_VSYSCALL
extern void update_vsyscall(struct timekeeper *tk);
extern void update_vsyscall_tz(void);
#elif defined(CONFIG_GENERIC_TIME_VSYSCALL_OLD)
extern void update_vsyscall_old(struct timespec *ts, struct timespec *wtm,
struct clocksource *c, u32 mult,
cycle_t cycle_last);
extern void update_vsyscall_tz(void);
#else
static inline void update_vsyscall(struct timekeeper *tk)
{
}
static inline void update_vsyscall_tz(void)
{
}
#endif
#endif /* _LINUX_TIMEKEEPER_INTERNAL_H */