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 /* Structure holding internal timekeeping values. */
  14 struct 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
  74 static 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
  86 extern void update_vsyscall(struct timekeeper *tk);
  87 extern void update_vsyscall_tz(void);
  88
  89 #elif defined(CONFIG_GENERIC_TIME_VSYSCALL_OLD)
  90
  91 extern void update_vsyscall_old(struct timespec *ts, struct timespec *wtm,
  92                                 struct clocksource *c, u32 mult);
  93 extern void update_vsyscall_tz(void);
  94
  95 static 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
 105 static inline void update_vsyscall(struct timekeeper *tk)
 106 {
 107 }
 108 static inline void update_vsyscall_tz(void)
 109 {
 110 }
 111 #endif
 112
 113 #endif /* _LINUX_TIMEKEEPER_INTERNAL_H */