LXR linux/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
  15void 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
  24void 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}
  70