mirror of https://gitee.com/openkylin/linux.git
84 lines
2.4 KiB
C
84 lines
2.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 2001 Andrea Arcangeli <andrea@suse.de> SuSE
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* Copyright 2003 Andi Kleen, SuSE Labs.
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*
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* Modified for x86 32 bit architecture by
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* Stefani Seibold <stefani@seibold.net>
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* sponsored by Rohde & Schwarz GmbH & Co. KG Munich/Germany
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*
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* Thanks to hpa@transmeta.com for some useful hint.
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* Special thanks to Ingo Molnar for his early experience with
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* a different vsyscall implementation for Linux/IA32 and for the name.
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*
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*/
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#include <linux/timekeeper_internal.h>
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#include <asm/vgtod.h>
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#include <asm/vvar.h>
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int vclocks_used __read_mostly;
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DEFINE_VVAR(struct vsyscall_gtod_data, vsyscall_gtod_data);
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void update_vsyscall_tz(void)
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{
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vsyscall_gtod_data.tz_minuteswest = sys_tz.tz_minuteswest;
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vsyscall_gtod_data.tz_dsttime = sys_tz.tz_dsttime;
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}
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void update_vsyscall(struct timekeeper *tk)
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{
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int vclock_mode = tk->tkr_mono.clock->archdata.vclock_mode;
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struct vsyscall_gtod_data *vdata = &vsyscall_gtod_data;
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struct vgtod_ts *base;
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u64 nsec;
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/* Mark the new vclock used. */
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BUILD_BUG_ON(VCLOCK_MAX >= 32);
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WRITE_ONCE(vclocks_used, READ_ONCE(vclocks_used) | (1 << vclock_mode));
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gtod_write_begin(vdata);
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/* copy vsyscall data */
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vdata->vclock_mode = vclock_mode;
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vdata->cycle_last = tk->tkr_mono.cycle_last;
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vdata->mask = tk->tkr_mono.mask;
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vdata->mult = tk->tkr_mono.mult;
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vdata->shift = tk->tkr_mono.shift;
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base = &vdata->basetime[CLOCK_REALTIME];
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base->sec = tk->xtime_sec;
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base->nsec = tk->tkr_mono.xtime_nsec;
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base = &vdata->basetime[CLOCK_TAI];
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base->sec = tk->xtime_sec + (s64)tk->tai_offset;
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base->nsec = tk->tkr_mono.xtime_nsec;
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base = &vdata->basetime[CLOCK_MONOTONIC];
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base->sec = tk->xtime_sec + tk->wall_to_monotonic.tv_sec;
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nsec = tk->tkr_mono.xtime_nsec;
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nsec += ((u64)tk->wall_to_monotonic.tv_nsec << tk->tkr_mono.shift);
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while (nsec >= (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift)) {
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nsec -= ((u64)NSEC_PER_SEC) << tk->tkr_mono.shift;
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base->sec++;
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}
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base->nsec = nsec;
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base = &vdata->basetime[CLOCK_REALTIME_COARSE];
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base->sec = tk->xtime_sec;
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base->nsec = tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift;
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base = &vdata->basetime[CLOCK_MONOTONIC_COARSE];
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base->sec = tk->xtime_sec + tk->wall_to_monotonic.tv_sec;
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nsec = tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift;
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nsec += tk->wall_to_monotonic.tv_nsec;
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while (nsec >= NSEC_PER_SEC) {
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nsec -= NSEC_PER_SEC;
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base->sec++;
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}
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base->nsec = nsec;
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gtod_write_end(vdata);
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}
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