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/seqlock.h>
  11 #include <linux/time.h>
  12 #include <linux/timekeeper_internal.h>
  13
  14 #include <asm/vvar.h>
  15
  16 void update_vsyscall_tz(void)
  17 {
  18         if (unlikely(vvar_data == NULL))
  19                 return;
  20
  21         vvar_data->tz_minuteswest = sys_tz.tz_minuteswest;
  22         vvar_data->tz_dsttime = sys_tz.tz_dsttime;
  23 }
  24
  25 void update_vsyscall(struct timekeeper *tk)
  26 {
  27         struct vvar_data *vdata = vvar_data;
  28
  29         if (unlikely(vdata == NULL))
  30                 return;
  31
  32         vvar_write_begin(vdata);
  33         vdata->vclock_mode = tk->tkr_mono.clock->archdata.vclock_mode;
  34         vdata->clock.cycle_last = tk->tkr_mono.cycle_last;
  35         vdata->clock.mask = tk->tkr_mono.mask;
  36         vdata->clock.mult = tk->tkr_mono.mult;
  37         vdata->clock.shift = tk->tkr_mono.shift;
  38
  39         vdata->wall_time_sec = tk->xtime_sec;
  40         vdata->wall_time_snsec = tk->tkr_mono.xtime_nsec;
  41
  42         vdata->monotonic_time_sec = tk->xtime_sec +
  43                                     tk->wall_to_monotonic.tv_sec;
  44         vdata->monotonic_time_snsec = tk->tkr_mono.xtime_nsec +
  45                                       (tk->wall_to_monotonic.tv_nsec <<
  46                                        tk->tkr_mono.shift);
  47
  48         while (vdata->monotonic_time_snsec >=
  49                (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift)) {
  50                 vdata->monotonic_time_snsec -=
  51                                 ((u64)NSEC_PER_SEC) << tk->tkr_mono.shift;
  52                 vdata->monotonic_time_sec++;
  53         }
  54
  55         vdata->wall_time_coarse_sec = tk->xtime_sec;
  56         vdata->wall_time_coarse_nsec =
  57                         (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift);
  58
  59         vdata->monotonic_time_coarse_sec =
  60                 vdata->wall_time_coarse_sec + tk->wall_to_monotonic.tv_sec;
  61         vdata->monotonic_time_coarse_nsec =
  62                 vdata->wall_time_coarse_nsec + tk->wall_to_monotonic.tv_nsec;
  63
  64         while (vdata->monotonic_time_coarse_nsec >= NSEC_PER_SEC) {
  65                 vdata->monotonic_time_coarse_nsec -= NSEC_PER_SEC;
  66                 vdata->monotonic_time_coarse_sec++;
  67         }
  68
  69         vvar_write_end(vdata);
  70 }