1/*
 2 *  Copyright (C) 2001 Andrea Arcangeli <andrea@suse.de> SuSE
 3 *  Copyright 2003 Andi Kleen, SuSE Labs.
 4 *
 5 *  Modified for x86 32 bit architecture by
 6 *  Stefani Seibold <stefani@seibold.net>
 7 *  sponsored by Rohde & Schwarz GmbH & Co. KG Munich/Germany
 8 *
 9 *  Thanks to hpa@transmeta.com for some useful hint.
10 *  Special thanks to Ingo Molnar for his early experience with
11 *  a different vsyscall implementation for Linux/IA32 and for the name.
12 *
13 */
14
15#include <linux/timekeeper_internal.h>
16#include <asm/vgtod.h>
17#include <asm/vvar.h>
18
19DEFINE_VVAR(struct vsyscall_gtod_data, vsyscall_gtod_data);
20
21void update_vsyscall_tz(void)
22{
23	vsyscall_gtod_data.tz_minuteswest = sys_tz.tz_minuteswest;
24	vsyscall_gtod_data.tz_dsttime = sys_tz.tz_dsttime;
25}
26
27void update_vsyscall(struct timekeeper *tk)
28{
29	struct vsyscall_gtod_data *vdata = &vsyscall_gtod_data;
30
31	gtod_write_begin(vdata);
32
33	/* copy vsyscall data */
34	vdata->vclock_mode	= tk->clock->archdata.vclock_mode;
35	vdata->cycle_last	= tk->clock->cycle_last;
36	vdata->mask		= tk->clock->mask;
37	vdata->mult		= tk->mult;
38	vdata->shift		= tk->shift;
39
40	vdata->wall_time_sec		= tk->xtime_sec;
41	vdata->wall_time_snsec		= tk->xtime_nsec;
42
43	vdata->monotonic_time_sec	= tk->xtime_sec
44					+ tk->wall_to_monotonic.tv_sec;
45	vdata->monotonic_time_snsec	= tk->xtime_nsec
46					+ ((u64)tk->wall_to_monotonic.tv_nsec
47						<< tk->shift);
48	while (vdata->monotonic_time_snsec >=
49					(((u64)NSEC_PER_SEC) << tk->shift)) {
50		vdata->monotonic_time_snsec -=
51					((u64)NSEC_PER_SEC) << tk->shift;
52		vdata->monotonic_time_sec++;
53	}
54
55	vdata->wall_time_coarse_sec	= tk->xtime_sec;
56	vdata->wall_time_coarse_nsec	= (long)(tk->xtime_nsec >> tk->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	gtod_write_end(vdata);
69}