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         /* Number of clock shifted nano seconds in one NTP interval. */
  24         u64                     xtime_interval;
  25         /* shifted nano seconds left over when rounding cycle_interval */
  26         s64                     xtime_remainder;
  27         /* Raw nano seconds accumulated per NTP interval. */
  28         u32                     raw_interval;
  29
  30         /* Current CLOCK_REALTIME time in seconds */
  31         u64                     xtime_sec;
  32         /* Clock shifted nano seconds */
  33         u64                     xtime_nsec;
  34
  35         /* Difference between accumulated time and NTP time in ntp
  36          * shifted nano seconds. */
  37         s64                     ntp_error;
  38         /* Shift conversion between clock shifted nano seconds and
  39          * ntp shifted nano seconds. */
  40         u32                     ntp_error_shift;
  41
  42         /*
  43          * wall_to_monotonic is what we need to add to xtime (or xtime corrected
  44          * for sub jiffie times) to get to monotonic time.  Monotonic is pegged
  45          * at zero at system boot time, so wall_to_monotonic will be negative,
  46          * however, we will ALWAYS keep the tv_nsec part positive so we can use
  47          * the usual normalization.
  48          *
  49          * wall_to_monotonic is moved after resume from suspend for the
  50          * monotonic time not to jump. We need to add total_sleep_time to
  51          * wall_to_monotonic to get the real boot based time offset.
  52          *
  53          * - wall_to_monotonic is no longer the boot time, getboottime must be
  54          * used instead.
  55          */
  56         struct timespec         wall_to_monotonic;
  57         /* Offset clock monotonic -> clock realtime */
  58         ktime_t                 offs_real;
  59         /* time spent in suspend */
  60         struct timespec         total_sleep_time;
  61         /* Offset clock monotonic -> clock boottime */
  62         ktime_t                 offs_boot;
  63         /* The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock. */
  64         struct timespec         raw_time;
  65         /* Seqlock for all timekeeper values */
  66         seqlock_t               lock;
  67 };
  68
  69 static inline struct timespec tk_xtime(struct timekeeper *tk)
  70 {
  71         struct timespec ts;
  72
  73         ts.tv_sec = tk->xtime_sec;
  74         ts.tv_nsec = (long)(tk->xtime_nsec >> tk->shift);
  75         return ts;
  76 }
  77
  78
  79 #ifdef CONFIG_GENERIC_TIME_VSYSCALL
  80
  81 extern void update_vsyscall(struct timekeeper *tk);
  82 extern void update_vsyscall_tz(void);
  83
  84 #elif defined(CONFIG_GENERIC_TIME_VSYSCALL_OLD)
  85
  86 extern void update_vsyscall_old(struct timespec *ts, struct timespec *wtm,
  87                                 struct clocksource *c, u32 mult);
  88 extern void update_vsyscall_tz(void);
  89
  90 static inline void update_vsyscall(struct timekeeper *tk)
  91 {
  92         struct timespec xt;
  93
  94         xt = tk_xtime(tk);
  95         update_vsyscall_old(&xt, &tk->wall_to_monotonic, tk->clock, tk->mult);
  96 }
  97
  98 #else
  99
 100 static inline void update_vsyscall(struct timekeeper *tk)
 101 {
 102 }
 103 static inline void update_vsyscall_tz(void)
 104 {
 105 }
 106 #endif
 107
 108 #endif /* _LINUX_TIMEKEEPER_INTERNAL_H */