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/*
* linux/arch/m68knommu/kernel/time.c
*
* Copyright (C) 1991, 1992, 1995 Linus Torvalds
*
* This file contains the m68k-specific time handling details.
* Most of the stuff is located in the machine specific files.
*
* 1997-09-10 Updated NTP code according to technical memorandum Jan '96
* "A Kernel Model for Precision Timekeeping" by Dave Mills
*/
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/param.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/profile.h>
#include <linux/time.h>
#include <linux/timex.h>
#include <asm/machdep.h>
#include <asm/irq_regs.h>
#define TICK_SIZE (tick_nsec / 1000)
static inline int set_rtc_mmss(unsigned long nowtime)
{
if (mach_set_clock_mmss)
return mach_set_clock_mmss (nowtime);
return -1;
}
static inline void do_set_rtc(void)
{
/* last time the cmos clock got updated */
static long last_rtc_update=0;
/*
* If we have an externally synchronized Linux clock, then update
* CMOS clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
* called as close as possible to 500 ms before the new second starts.
*/
if (ntp_synced() &&
xtime.tv_sec > last_rtc_update + 660 &&
(xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 &&
(xtime.tv_nsec / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 2) {
if (set_rtc_mmss(xtime.tv_sec) == 0)
last_rtc_update = xtime.tv_sec;
else
last_rtc_update = xtime.tv_sec - 600; /* do it again in 60 s */
}
}
/*
* timer_interrupt() needs to keep up the real-time clock,
* as well as call the "do_timer()" routine every clocktick
*/
irqreturn_t arch_timer_interrupt(int irq, void *dummy)
{
if (current->pid)
profile_tick(CPU_PROFILING);
write_seqlock(&xtime_lock);
do_timer(1);
do_set_rtc();
write_sequnlock(&xtime_lock);
#ifndef CONFIG_SMP
update_process_times(user_mode(get_irq_regs()));
#endif
return(IRQ_HANDLED);
}
static unsigned long read_rtc_mmss(void)
{
unsigned int year, mon, day, hour, min, sec;
if (mach_gettod)
mach_gettod(&year, &mon, &day, &hour, &min, &sec);
else
year = mon = day = hour = min = sec = 0;
if ((year += 1900) < 1970)
year += 100;
return mktime(year, mon, day, hour, min, sec);;
}
void time_init(void)
{
xtime.tv_sec = read_rtc_mmss();
xtime.tv_nsec = 0;
wall_to_monotonic.tv_sec = -xtime.tv_sec;
hw_timer_init();
}
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