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}