include/linux/timekeeper_internal.h

   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 /*
  14  * Structure holding internal timekeeping values.
  15  *
  16  * Note: wall_to_monotonic is what we need to add to xtime (or xtime
  17  * corrected for sub jiffie times) to get to monotonic time.
  18  * Monotonic is pegged at zero at system boot time, so
  19  * wall_to_monotonic will be negative, however, we will ALWAYS keep
  20  * the tv_nsec part positive so we can use the usual normalization.
  21  *
  22  * wall_to_monotonic is moved after resume from suspend for the
  23  * monotonic time not to jump. We need to add total_sleep_time to
  24  * wall_to_monotonic to get the real boot based time offset.
  25  *
  26  * - wall_to_monotonic is no longer the boot time, getboottime must be
  27  * used instead.
  28  */
  29 struct timekeeper {
  30         /* Current clocksource used for timekeeping. */
  31         struct clocksource      *clock;
  32         /* NTP adjusted clock multiplier */
  33         u32                     mult;
  34         /* The shift value of the current clocksource. */
  35         u32                     shift;
  36         /* Clock shifted nano seconds */
  37         u64                     xtime_nsec;
  38
  39         /* Monotonic base time */
  40         ktime_t                 base_mono;
  41
  42         /* Current CLOCK_REALTIME time in seconds */
  43         u64                     xtime_sec;
  44         /* CLOCK_REALTIME to CLOCK_MONOTONIC offset */
  45         struct timespec64       wall_to_monotonic;
  46
  47         /* Offset clock monotonic -> clock realtime */
  48         ktime_t                 offs_real;
  49         /* Offset clock monotonic -> clock boottime */
  50         ktime_t                 offs_boot;
  51         /* Offset clock monotonic -> clock tai */
  52         ktime_t                 offs_tai;
  53
  54         /* time spent in suspend */
  55         struct timespec64       total_sleep_time;
  56         /* The current UTC to TAI offset in seconds */
  57         s32                     tai_offset;
  58
  59         /* The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock. */
  60         struct timespec64       raw_time;
  61
  62         /* Number of clock cycles in one NTP interval. */
  63         cycle_t                 cycle_interval;
  64         /* Last cycle value (also stored in clock->cycle_last) */
  65         cycle_t                 cycle_last;
  66         /* Number of clock shifted nano seconds in one NTP interval. */
  67         u64                     xtime_interval;
  68         /* shifted nano seconds left over when rounding cycle_interval */
  69         s64                     xtime_remainder;
  70         /* Raw nano seconds accumulated per NTP interval. */
  71         u32                     raw_interval;
  72
  73         /*
  74          * Difference between accumulated time and NTP time in ntp
  75          * shifted nano seconds.
  76          */
  77         s64                     ntp_error;
  78         /*
  79          * Shift conversion between clock shifted nano seconds and
  80          * ntp shifted nano seconds.
  81          */
  82         u32                     ntp_error_shift;
  83 };
  84
  85 #ifdef CONFIG_GENERIC_TIME_VSYSCALL
  86
  87 extern void update_vsyscall(struct timekeeper *tk);
  88 extern void update_vsyscall_tz(void);
  89
  90 #elif defined(CONFIG_GENERIC_TIME_VSYSCALL_OLD)
  91
  92 extern void update_vsyscall_old(struct timespec *ts, struct timespec *wtm,
  93                                 struct clocksource *c, u32 mult);
  94 extern void update_vsyscall_tz(void);
  95
  96 #else
  97
  98 static inline void update_vsyscall(struct timekeeper *tk)
  99 {
 100 }
 101 static inline void update_vsyscall_tz(void)
 102 {
 103 }
 104 #endif
 105
 106 #endif /* _LINUX_TIMEKEEPER_INTERNAL_H */