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/*
* linux/arch/m68k/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> /* CONFIG_HEARTBEAT */
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/param.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <asm/machdep.h>
#include <asm/io.h>
#include <linux/timex.h>
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_profile (unsigned long pc)
{
if (prof_buffer && current->pid) {
extern int _stext;
pc -= (unsigned long) &_stext;
pc >>= prof_shift;
if (pc < prof_len)
++prof_buffer[pc];
else
/*
* Don't ignore out-of-bounds PC values silently,
* put them into the last histogram slot, so if
* present, they will show up as a sharp peak.
*/
++prof_buffer[prof_len-1];
}
}
/*
* timer_interrupt() needs to keep up the real-time clock,
* as well as call the "do_timer()" routine every clocktick
*/
static void timer_interrupt(int irq, void *dummy, struct pt_regs * regs)
{
/* last time the cmos clock got updated */
static long last_rtc_update=0;
do_timer(regs);
if (!user_mode(regs))
do_profile(regs->pc);
/*
* 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 ((time_status & STA_UNSYNC) == 0 &&
xtime.tv_sec > last_rtc_update + 660 &&
xtime.tv_usec >= 500000 - ((unsigned) tick) / 2 &&
xtime.tv_usec <= 500000 + ((unsigned) tick) / 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 */
}
/* Converts Gregorian date to seconds since 1970-01-01 00:00:00.
* Assumes input in normal date format, i.e. 1980-12-31 23:59:59
* => year=1980, mon=12, day=31, hour=23, min=59, sec=59.
*
* [For the Julian calendar (which was used in Russia before 1917,
* Britain & colonies before 1752, anywhere else before 1582,
* and is still in use by some communities) leave out the
* -year/100+year/400 terms, and add 10.]
*
* This algorithm was first published by Gauss (I think).
*
* WARNING: this function will overflow on 2106-02-07 06:28:16 on
* machines were long is 32-bit! (However, as time_t is signed, we
* will already get problems at other places on 2038-01-19 03:14:08)
*/
static inline unsigned long mktime(unsigned int year, unsigned int mon,
unsigned int day, unsigned int hour,
unsigned int min, unsigned int sec)
{
if (0 >= (int) (mon -= 2)) { /* 1..12 -> 11,12,1..10 */
mon += 12; /* Puts Feb last since it has leap day */
year -= 1;
}
return (((
(unsigned long)(year/4 - year/100 + year/400 + 367*mon/12 + day) +
year*365 - 719499
)*24 + hour /* now have hours */
)*60 + min /* now have minutes */
)*60 + sec; /* finally seconds */
}
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_usec = 0;
mach_sched_init(timer_interrupt);
}
extern rwlock_t xtime_lock;
/*
* This version of gettimeofday has near microsecond resolution.
*/
void do_gettimeofday(struct timeval *tv)
{
extern volatile unsigned long lost_ticks;
unsigned long flags;
unsigned long usec, sec, lost;
read_lock_irqsave(&xtime_lock, flags);
usec = mach_gettimeoffset();
lost = lost_ticks;
if (lost)
usec += lost * (1000000/HZ);
sec = xtime.tv_sec;
usec += xtime.tv_usec;
read_unlock_irqrestore(&xtime_lock, flags);
while (usec >= 1000000) {
usec -= 1000000;
sec++;
}
tv->tv_sec = sec;
tv->tv_usec = usec;
}
void do_settimeofday(struct timeval *tv)
{
write_lock_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!
*/
tv->tv_usec -= mach_gettimeoffset();
while (tv->tv_usec < 0) {
tv->tv_usec += 1000000;
tv->tv_sec--;
}
xtime = *tv;
time_adjust = 0; /* stop active adjtime() */
time_status |= STA_UNSYNC;
time_state = TIME_ERROR; /* p. 24, (a) */
time_maxerror = NTP_PHASE_LIMIT;
time_esterror = NTP_PHASE_LIMIT;
sti();
}
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