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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2001 Andrea Arcangeli <andrea@suse.de> SuSE
* Copyright 2003 Andi Kleen, SuSE Labs.
*
* Modified for x86 32 bit architecture by
* Stefani Seibold <stefani@seibold.net>
* sponsored by Rohde & Schwarz GmbH & Co. KG Munich/Germany
*
* Thanks to hpa@transmeta.com for some useful hint.
* Special thanks to Ingo Molnar for his early experience with
* a different vsyscall implementation for Linux/IA32 and for the name.
*
*/
#include <linux/timekeeper_internal.h>
#include <asm/vgtod.h>
#include <asm/vvar.h>
int vclocks_used __read_mostly;
DEFINE_VVAR(struct vsyscall_gtod_data, vsyscall_gtod_data);
void update_vsyscall_tz(void)
{
vsyscall_gtod_data.tz_minuteswest = sys_tz.tz_minuteswest;
vsyscall_gtod_data.tz_dsttime = sys_tz.tz_dsttime;
}
void update_vsyscall(struct timekeeper *tk)
{
int vclock_mode = tk->tkr_mono.clock->archdata.vclock_mode;
struct vsyscall_gtod_data *vdata = &vsyscall_gtod_data;
/* Mark the new vclock used. */
BUILD_BUG_ON(VCLOCK_MAX >= 32);
WRITE_ONCE(vclocks_used, READ_ONCE(vclocks_used) | (1 << vclock_mode));
gtod_write_begin(vdata);
/* copy vsyscall data */
vdata->vclock_mode = vclock_mode;
vdata->cycle_last = tk->tkr_mono.cycle_last;
vdata->mask = tk->tkr_mono.mask;
vdata->mult = tk->tkr_mono.mult;
vdata->shift = tk->tkr_mono.shift;
vdata->wall_time_sec = tk->xtime_sec;
vdata->wall_time_snsec = tk->tkr_mono.xtime_nsec;
vdata->monotonic_time_sec = tk->xtime_sec
+ tk->wall_to_monotonic.tv_sec;
vdata->monotonic_time_snsec = tk->tkr_mono.xtime_nsec
+ ((u64)tk->wall_to_monotonic.tv_nsec
<< tk->tkr_mono.shift);
while (vdata->monotonic_time_snsec >=
(((u64)NSEC_PER_SEC) << tk->tkr_mono.shift)) {
vdata->monotonic_time_snsec -=
((u64)NSEC_PER_SEC) << tk->tkr_mono.shift;
vdata->monotonic_time_sec++;
}
vdata->wall_time_coarse_sec = tk->xtime_sec;
vdata->wall_time_coarse_nsec = (long)(tk->tkr_mono.xtime_nsec >>
tk->tkr_mono.shift);
vdata->monotonic_time_coarse_sec =
vdata->wall_time_coarse_sec + tk->wall_to_monotonic.tv_sec;
vdata->monotonic_time_coarse_nsec =
vdata->wall_time_coarse_nsec + tk->wall_to_monotonic.tv_nsec;
while (vdata->monotonic_time_coarse_nsec >= NSEC_PER_SEC) {
vdata->monotonic_time_coarse_nsec -= NSEC_PER_SEC;
vdata->monotonic_time_coarse_sec++;
}
gtod_write_end(vdata);
}
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