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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/config.h>
#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/io.h>
#define TICK_SIZE (tick_nsec / 1000)
extern unsigned long wall_jiffies;
static inline int set_rtc_mmss(unsigned long nowtime)
{
if (mach_set_clock_mmss)
return mach_set_clock_mmss (nowtime);
return -1;
}
/*
* timer_interrupt() needs to keep up the real-time clock,
* as well as call the "do_timer()" routine every clocktick
*/
static irqreturn_t timer_interrupt(int irq, void *dummy, struct pt_regs * regs)
{
/* last time the cmos clock got updated */
static long last_rtc_update=0;
/* may need to kick the hardware timer */
if (mach_tick)
mach_tick();
write_seqlock(&xtime_lock);
do_timer(regs);
#ifndef CONFIG_SMP
update_process_times(user_mode(regs));
#endif
if (current->pid)
profile_tick(CPU_PROFILING, regs);
/*
* 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 */
}
#ifdef CONFIG_HEARTBEAT
/* use power LED as a heartbeat instead -- much more useful
for debugging -- based on the version for PReP by Cort */
/* acts like an actual heart beat -- ie thump-thump-pause... */
if (mach_heartbeat) {
static unsigned cnt = 0, period = 0, dist = 0;
if (cnt == 0 || cnt == dist)
mach_heartbeat( 1 );
else if (cnt == 7 || cnt == dist+7)
mach_heartbeat( 0 );
if (++cnt > period) {
cnt = 0;
/* The hyperbolic function below modifies the heartbeat period
* length in dependency of the current (5min) load. It goes
* through the points f(0)=126, f(1)=86, f(5)=51,
* f(inf)->30. */
period = ((672<<FSHIFT)/(5*avenrun[0]+(7<<FSHIFT))) + 30;
dist = period / 4;
}
}
#endif /* CONFIG_HEARTBEAT */
write_sequnlock(&xtime_lock);
return(IRQ_HANDLED);
}
void time_init(void)
{
unsigned int year, mon, day, hour, min, sec;
extern void arch_gettod(int *year, int *mon, int *day, int *hour,
int *min, int *sec);
arch_gettod(&year, &mon, &day, &hour, &min, &sec);
if ((year += 1900) < 1970)
year += 100;
xtime.tv_sec = mktime(year, mon, day, hour, min, sec);
xtime.tv_nsec = 0;
wall_to_monotonic.tv_sec = -xtime.tv_sec;
mach_sched_init(timer_interrupt);
}
/*
* This version of gettimeofday has near microsecond resolution.
*/
void do_gettimeofday(struct timeval *tv)
{
unsigned long flags;
unsigned long lost, seq;
unsigned long usec, sec;
do {
seq = read_seqbegin_irqsave(&xtime_lock, flags);
usec = mach_gettimeoffset ? mach_gettimeoffset() : 0;
lost = jiffies - wall_jiffies;
if (lost)
usec += lost * (1000000 / HZ);
sec = xtime.tv_sec;
usec += (xtime.tv_nsec / 1000);
} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
while (usec >= 1000000) {
usec -= 1000000;
sec++;
}
tv->tv_sec = sec;
tv->tv_usec = usec;
}
EXPORT_SYMBOL(do_gettimeofday);
int do_settimeofday(struct timespec *tv)
{
time_t wtm_sec, sec = tv->tv_sec;
long wtm_nsec, nsec = tv->tv_nsec;
if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
return -EINVAL;
write_seqlock_irq(&xtime_lock);
/*
* This is revolting. We need to set the xtime.tv_usec
* correctly. However, the value in this location is
* is value at the last tick.
* Discover what correction gettimeofday
* would have done, and then undo it!
*/
if (mach_gettimeoffset)
nsec -= (mach_gettimeoffset() * 1000);
wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
set_normalized_timespec(&xtime, sec, nsec);
set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
ntp_clear();
write_sequnlock_irq(&xtime_lock);
clock_was_set();
return 0;
}
/*
* Scheduler clock - returns current time in nanosec units.
*/
unsigned long long sched_clock(void)
{
return (unsigned long long)jiffies * (1000000000 / HZ);
}
EXPORT_SYMBOL(do_settimeofday);
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