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. To calculate the real boot time offset
  24  * we need to do offs_real - offs_boot.
  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         /* The current UTC to TAI offset in seconds */
  55         s32                     tai_offset;
  56
  57         /* Monotonic raw base time */
  58         ktime_t                 base_raw;
  59
  60         /* The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock. */
  61         struct timespec64       raw_time;
  62
  63         /* Number of clock cycles in one NTP interval. */
  64         cycle_t                 cycle_interval;
  65         /* Last cycle value (also stored in clock->cycle_last) */
  66         cycle_t                 cycle_last;
  67         /* Number of clock shifted nano seconds in one NTP interval. */
  68         u64                     xtime_interval;
  69         /* shifted nano seconds left over when rounding cycle_interval */
  70         s64                     xtime_remainder;
  71         /* Raw nano seconds accumulated per NTP interval. */
  72         u32                     raw_interval;
  73
  74         /*
  75          * Difference between accumulated time and NTP time in ntp
  76          * shifted nano seconds.
  77          */
  78         s64                     ntp_error;
  79         /*
  80          * Shift conversion between clock shifted nano seconds and
  81          * ntp shifted nano seconds.
  82          */
  83         u32                     ntp_error_shift;
  84 };
  85
  86 #ifdef CONFIG_GENERIC_TIME_VSYSCALL
  87
  88 extern void update_vsyscall(struct timekeeper *tk);
  89 extern void update_vsyscall_tz(void);
  90
  91 #elif defined(CONFIG_GENERIC_TIME_VSYSCALL_OLD)
  92
  93 extern void update_vsyscall_old(struct timespec *ts, struct timespec *wtm,
  94                                 struct clocksource *c, u32 mult);
  95 extern void update_vsyscall_tz(void);
  96
  97 #else
  98
  99 static inline void update_vsyscall(struct timekeeper *tk)
 100 {
 101 }
 102 static inline void update_vsyscall_tz(void)
 103 {
 104 }
 105 #endif
 106
 107 #endif /* _LINUX_TIMEKEEPER_INTERNAL_H */