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/* Copyright (c) 2012, The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/export.h>
#include <linux/clocksource.h>
#include <linux/time.h>
#include "update_vsyscall_arm.h"
/*
* See entry-armv.S for the offsets into the kernel user helper for
* these fields.
*/
#define ARM_VSYSCALL_TIMER_TZ 0xf20
#define ARM_VSYSCALL_TIMER_SEQ 0xf28
#define ARM_VSYSCALL_TIMER_OFFSET 0xf30
#define ARM_VSYSCALL_TIMER_WTM_TV_SEC 0xf38
#define ARM_VSYSCALL_TIMER_WTM_TV_NSEC 0xf3c
#define ARM_VSYSCALL_TIMER_CYCLE_LAST 0xf40
#define ARM_VSYSCALL_TIMER_MASK 0xf48
#define ARM_VSYSCALL_TIMER_MULT 0xf50
#define ARM_VSYSCALL_TIMER_SHIFT 0xf54
#define ARM_VSYSCALL_TIMER_TV_SEC 0xf58
#define ARM_VSYSCALL_TIMER_TV_NSEC 0xf5c
struct kernel_gtod_t {
u64 cycle_last;
u64 mask;
u32 mult;
u32 shift;
u32 tv_sec;
u32 tv_nsec;
};
struct kernel_tz_t {
u32 tz_minuteswest;
u32 tz_dsttime;
};
struct kernel_wtm_t {
u32 tv_sec;
u32 tv_nsec;
};
/*
* Updates the kernel user helper area with the current timespec
* data, as well as additional fields needed to calculate
* gettimeofday, clock_gettime, etc.
*/
void
update_vsyscall(struct timespec *ts, struct timespec *wtm,
struct clocksource *c, u32 mult)
{
unsigned long vectors = (unsigned long)vectors_page;
unsigned long flags;
unsigned *seqnum = (unsigned *)(vectors + ARM_VSYSCALL_TIMER_SEQ);
struct kernel_gtod_t *dgtod = (struct kernel_gtod_t *)(vectors +
ARM_VSYSCALL_TIMER_CYCLE_LAST);
struct kernel_wtm_t *dgwtm = (struct kernel_wtm_t *)(vectors +
ARM_VSYSCALL_TIMER_WTM_TV_SEC);
write_seqlock_irqsave(&kuh_time_lock, flags);
*seqnum = kuh_time_lock.sequence;
dgtod->cycle_last = c->cycle_last;
dgtod->mask = c->mask;
dgtod->mult = c->mult;
dgtod->shift = c->shift;
dgtod->tv_sec = ts->tv_sec;
dgtod->tv_nsec = ts->tv_nsec;
dgwtm->tv_sec = wtm->tv_sec;
dgwtm->tv_nsec = wtm->tv_nsec;
*seqnum = kuh_time_lock.sequence + 1;
write_sequnlock_irqrestore(&kuh_time_lock, flags);
}
EXPORT_SYMBOL(update_vsyscall);
void
update_vsyscall_tz(void)
{
unsigned long vectors = (unsigned long)vectors_page;
unsigned long flags;
unsigned *seqnum = (unsigned *)(vectors + ARM_VSYSCALL_TIMER_SEQ);
struct kernel_tz_t *dgtod = (struct kernel_tz_t *)(vectors +
ARM_VSYSCALL_TIMER_TZ);
write_seqlock_irqsave(&kuh_time_lock, flags);
*seqnum = kuh_time_lock.sequence;
dgtod->tz_minuteswest = sys_tz.tz_minuteswest;
dgtod->tz_dsttime = sys_tz.tz_dsttime;
*seqnum = kuh_time_lock.sequence + 1;
write_sequnlock_irqrestore(&kuh_time_lock, flags);
}
EXPORT_SYMBOL(update_vsyscall_tz);
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