arch/sparc/kernel/vdso.c

   1 /*
   2  *  Copyright (C) 2001 Andrea Arcangeli <andrea@suse.de> SuSE
   3  *  Copyright 2003 Andi Kleen, SuSE Labs.
   4  *
   5  *  Thanks to hpa@transmeta.com for some useful hint.
   6  *  Special thanks to Ingo Molnar for his early experience with
   7  *  a different vsyscall implementation for Linux/IA32 and for the name.
   8  */
   9
  10 #include <linux/time.h>
  11 #include <linux/timekeeper_internal.h>
  12
  13 #include <asm/vvar.h>
  14
  15 void update_vsyscall_tz(void)
  16 {
  17         if (unlikely(vvar_data == NULL))
  18                 return;
  19
  20         vvar_data->tz_minuteswest = sys_tz.tz_minuteswest;
  21         vvar_data->tz_dsttime = sys_tz.tz_dsttime;
  22 }
  23
  24 void update_vsyscall(struct timekeeper *tk)
  25 {
  26         struct vvar_data *vdata = vvar_data;
  27
  28         if (unlikely(vdata == NULL))
  29                 return;
  30
  31         vvar_write_begin(vdata);
  32         vdata->vclock_mode = tk->tkr_mono.clock->archdata.vclock_mode;
  33         vdata->clock.cycle_last = tk->tkr_mono.cycle_last;
  34         vdata->clock.mask = tk->tkr_mono.mask;
  35         vdata->clock.mult = tk->tkr_mono.mult;
  36         vdata->clock.shift = tk->tkr_mono.shift;
  37
  38         vdata->wall_time_sec = tk->xtime_sec;
  39         vdata->wall_time_snsec = tk->tkr_mono.xtime_nsec;
  40
  41         vdata->monotonic_time_sec = tk->xtime_sec +
  42                                     tk->wall_to_monotonic.tv_sec;
  43         vdata->monotonic_time_snsec = tk->tkr_mono.xtime_nsec +
  44                                       (tk->wall_to_monotonic.tv_nsec <<
  45                                        tk->tkr_mono.shift);
  46
  47         while (vdata->monotonic_time_snsec >=
  48                (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift)) {
  49                 vdata->monotonic_time_snsec -=
  50                                 ((u64)NSEC_PER_SEC) << tk->tkr_mono.shift;
  51                 vdata->monotonic_time_sec++;
  52         }
  53
  54         vdata->wall_time_coarse_sec = tk->xtime_sec;
  55         vdata->wall_time_coarse_nsec =
  56                         (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift);
  57
  58         vdata->monotonic_time_coarse_sec =
  59                 vdata->wall_time_coarse_sec + tk->wall_to_monotonic.tv_sec;
  60         vdata->monotonic_time_coarse_nsec =
  61                 vdata->wall_time_coarse_nsec + tk->wall_to_monotonic.tv_nsec;
  62
  63         while (vdata->monotonic_time_coarse_nsec >= NSEC_PER_SEC) {
  64                 vdata->monotonic_time_coarse_nsec -= NSEC_PER_SEC;
  65                 vdata->monotonic_time_coarse_sec++;
  66         }
  67
  68         vvar_write_end(vdata);
  69 }