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/seqlock.h>
  11#include <linux/time.h>
  12#include <linux/timekeeper_internal.h>
  13
  14#include <asm/vvar.h>
  15
  16void 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
  25void 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}
  71