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

source code of linux/arch/sparc/kernel/vdso.c