LXR linux/include/linux/timekeeper

   1/*
   2 * You SHOULD NOT be including this unless you're vsyscall
   3 * handling code or timekeeping internal code!
   4 */
   5
   6#ifndef _LINUX_TIMEKEEPER_INTERNAL_H
   7#define _LINUX_TIMEKEEPER_INTERNAL_H
   8
   9#include <linux/clocksource.h>
  10#include <linux/jiffies.h>
  11#include <linux/time.h>
  12
  13/* Structure holding internal timekeeping values. */
  14struct timekeeper {
  15        /* Current clocksource used for timekeeping. */
  16        struct clocksource      *clock;
  17        /* NTP adjusted clock multiplier */
  18        u32                     mult;
  19        /* The shift value of the current clocksource. */
  20        u32                     shift;
  21        /* Number of clock cycles in one NTP interval. */
  22        cycle_t                 cycle_interval;
  23        /* Last cycle value (also stored in clock->cycle_last) */
  24        cycle_t                 cycle_last;
  25        /* Number of clock shifted nano seconds in one NTP interval. */
  26        u64                     xtime_interval;
  27        /* shifted nano seconds left over when rounding cycle_interval */
  28        s64                     xtime_remainder;
  29        /* Raw nano seconds accumulated per NTP interval. */
  30        u32                     raw_interval;
  31
  32        /* Current CLOCK_REALTIME time in seconds */
  33        u64                     xtime_sec;
  34        /* Clock shifted nano seconds */
  35        u64                     xtime_nsec;
  36
  37        /* Difference between accumulated time and NTP time in ntp
  38         * shifted nano seconds. */
  39        s64                     ntp_error;
  40        /* Shift conversion between clock shifted nano seconds and
  41         * ntp shifted nano seconds. */
  42        u32                     ntp_error_shift;
  43
  44        /*
  45         * wall_to_monotonic is what we need to add to xtime (or xtime corrected
  46         * for sub jiffie times) to get to monotonic time.  Monotonic is pegged
  47         * at zero at system boot time, so wall_to_monotonic will be negative,
  48         * however, we will ALWAYS keep the tv_nsec part positive so we can use
  49         * the usual normalization.
  50         *
  51         * wall_to_monotonic is moved after resume from suspend for the
  52         * monotonic time not to jump. We need to add total_sleep_time to
  53         * wall_to_monotonic to get the real boot based time offset.
  54         *
  55         * - wall_to_monotonic is no longer the boot time, getboottime must be
  56         * used instead.
  57         */
  58        struct timespec         wall_to_monotonic;
  59        /* Offset clock monotonic -> clock realtime */
  60        ktime_t                 offs_real;
  61        /* time spent in suspend */
  62        struct timespec         total_sleep_time;
  63        /* Offset clock monotonic -> clock boottime */
  64        ktime_t                 offs_boot;
  65        /* The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock. */
  66        struct timespec         raw_time;
  67        /* The current UTC to TAI offset in seconds */
  68        s32                     tai_offset;
  69        /* Offset clock monotonic -> clock tai */
  70        ktime_t                 offs_tai;
  71
  72};
  73
  74static inline struct timespec tk_xtime(struct timekeeper *tk)
  75{
  76        struct timespec ts;
  77
  78        ts.tv_sec = tk->xtime_sec;
  79        ts.tv_nsec = (long)(tk->xtime_nsec >> tk->shift);
  80        return ts;
  81}
  82
  83
  84#ifdef CONFIG_GENERIC_TIME_VSYSCALL
  85
  86extern void update_vsyscall(struct timekeeper *tk);
  87extern void update_vsyscall_tz(void);
  88
  89#elif defined(CONFIG_GENERIC_TIME_VSYSCALL_OLD)
  90
  91extern void update_vsyscall_old(struct timespec *ts, struct timespec *wtm,
  92                                struct clocksource *c, u32 mult);
  93extern void update_vsyscall_tz(void);
  94
  95static inline void update_vsyscall(struct timekeeper *tk)
  96{
  97        struct timespec xt;
  98
  99        xt = tk_xtime(tk);
 100        update_vsyscall_old(&xt, &tk->wall_to_monotonic, tk->clock, tk->mult);
 101}
 102
 103#else
 104
 105static inline void update_vsyscall(struct timekeeper *tk)
 106{
 107}
 108static inline void update_vsyscall_tz(void)
 109{
 110}
 111#endif
 112
 113#endif /* _LINUX_TIMEKEEPER_INTERNAL_H */
 114