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seta75D 2e8a93c394 Init
2021-10-11 18:20:23 -03:00

457 lines
12 KiB
C

#ifndef lint
static char sccsid[] = "@(#)clock.c 1.1 92/07/30";
#endif
/*
* Copyright (c) 1987 by Sun Microsystems, Inc.
*/
#include <sys/param.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <machine/clock.h>
#include <machine/interreg.h>
struct timeval todget();
/*
* Machine-dependent clock routines.
*
* Startrtclock restarts the real-time clock, which provides
* hardclock interrupts to kern_clock.c.
*
* Inittodr initializes the time of day hardware which provides
* date functions. Its primary function is to use some file
* system information in case the hardare clock lost state.
*
* Resettodr restores the time of day hardware after a time change.
*/
/*
* Start the real-time clock.
*/
startrtclock()
{
/*
* We will set things up to interrupt every 1/100 of a second.
* locore.s currently only calls hardclock every other clock
* interrupt, thus assuming 50 hz operation.
*/
if (hz != 50)
panic("startrtclock");
CLKADDR->clk_intrreg = CLK_INT_HSEC; /* set 1/100 sec clock intr */
set_clk_mode(IR_ENA_CLK5, 0); /* turn on level 5 clock intr */
}
/*
* Set and/or clear the desired clock bits in the interrupt
* register. We have to be extremely careful that we do it
* in such a manner that we don't get ourselves lost.
*/
set_clk_mode(on, off)
u_char on, off;
{
register u_char interreg, dummy;
/*
* make sure that we are only playing w/
* clock interrupt register bits
*/
on &= (IR_ENA_CLK7 | IR_ENA_CLK5);
off &= (IR_ENA_CLK7 | IR_ENA_CLK5);
/*
* Get a copy of current interrupt register,
* turning off any undesired bits (aka `off')
*/
interreg = *INTERREG & ~(off | IR_ENA_INT);
*INTERREG &= ~IR_ENA_INT;
/*
* Next we turns off the CLK5 and CLK7 bits to clear
* the flip-flops, then we disable clock interrupts.
* Now we can read the clock's interrupt register
* to clear any pending signals there.
*/
*INTERREG &= ~(IR_ENA_CLK7 | IR_ENA_CLK5);
CLKADDR->clk_cmd = (CLK_CMD_NORMAL & ~CLK_CMD_INTRENA);
dummy = CLKADDR->clk_intrreg; /* clear clock */
#ifdef lint
dummy = dummy;
#endif
/*
* Now we set all the desired bits
* in the interrupt register, then
* we turn the clock back on and
* finally we can enable all interrupts.
*/
*INTERREG |= (interreg | on); /* enable flip-flops */
CLKADDR->clk_cmd = CLK_CMD_NORMAL; /* enable clock intr */
*INTERREG |= IR_ENA_INT; /* enable interrupts */
}
int dosynctodr = 1; /* if true, sync UNIX time to TOD */
int clkdrift = 0; /* if true, show UNIX & TOD sync differences */
int synctodrval = 30; /* number of seconds between synctodr */
extern long timedelta;
extern int tickadj;
extern int tickdelta;
extern int doresettodr;
/* if true, continue to check time, but do not correct drift */
int allowdrift = 0;
/* if true, correct large jumps by resetting tod clock */
int fixtodjump = 1;
/* if true, report all tod errors */
int toddebug = 0;
#define ABS(x) ((x) < 0? -(x) : (x))
synctodr()
{
int deltat, s;
/*
* If timedelta is non-zero, assume someone who
* knows better is already adjusting the time.
*/
if (dosynctodr && timedelta == 0 && doresettodr == 0) {
s = splclock();
deltat = chkdeltat(0);
if (ABS(deltat) > 1000000 / hz && !allowdrift) {
/*
* partially simulate actions in adjtime (kern_time.c)
* give ourselves the ability to catch up quick
* for large drift...
* mjacob 9/20/87
*/
extern long bigadj;
timedelta = deltat;
if (ABS(deltat) > bigadj)
tickdelta = 10*tickadj;
else
tickdelta = tickadj; /* standard slew rate */
if (clkdrift)
printf("clkdrift: %d msec\n", deltat / 1000);
}
(void) splx(s);
}
timeout(synctodr, (caddr_t)0, synctodrval * hz);
}
/*
* Initialize the system time, based on the time base which is, e.g. from
* a filesystem. A base of -1 means the file system doesn't keep time.
*/
inittodr(base)
time_t base;
{
register long deltat;
int s;
s = splclock();
time = todget();
(void) splx(s);
if (time.tv_sec < SECYR) {
if (base == -1)
time.tv_sec = (87 - YRREF) * SECYR; /* ~1987 */
else
time.tv_sec = base;
printf("WARNING: TOD clock not initialized");
resettodr();
goto check;
}
if (base == -1)
goto out;
if (base < (87 - YRREF) * SECYR) { /* ~1987 */
printf("WARNING: preposterous time in file system");
goto check;
}
deltat = time.tv_sec - base;
/*
* See if we gained/lost two or more days;
* if so, assume something is amiss.
*/
if (deltat < 0)
deltat = -deltat;
if (deltat < 2*SECDAY)
goto out;
printf("WARNING: clock %s %d days",
time.tv_sec < base ? "lost" : "gained", deltat / SECDAY);
check:
printf(" -- CHECK AND RESET THE DATE!\n");
out:
if (dosynctodr)
timeout(synctodr, (caddr_t)0, synctodrval * hz);
}
/*
* For Sun-3, we use the Intersil ICM7170 for both the
* real time clock and the time-of-day device.
*/
static u_int monthsec[12] = {
31 * SECDAY, /* Jan */
28 * SECDAY, /* Feb */
31 * SECDAY, /* Mar */
30 * SECDAY, /* Apr */
31 * SECDAY, /* May */
30 * SECDAY, /* Jun */
31 * SECDAY, /* Jul */
31 * SECDAY, /* Aug */
30 * SECDAY, /* Sep */
31 * SECDAY, /* Oct */
30 * SECDAY, /* Nov */
31 * SECDAY /* Dec */
};
#define MONTHSEC(mon, yr) \
(((((yr) % 4) == 0) && ((mon) == 2))? 29*SECDAY : monthsec[(mon) - 1])
/*
* Set the TOD based on the argument value; used when the TOD
* has a preposterous value and also when the time is reset
* by the settimeofday system call. We run at splclock() to
* avoid synctodr() from running and getting confused.
*/
resettodr()
{
register int t;
u_short hsec, sec, min, hour, day, mon, weekday, year;
int s;
s = splclock();
/*
* Figure out the (adjusted) year
*/
t = time.tv_sec;
for (year = (YRREF - YRBASE); t > SECYEAR(year); year++)
t -= SECYEAR(year);
/*
* Figure out what month this is by subtracting off
* time per month, adjust for leap year if appropriate.
*/
for (mon = 1; t >= 0; mon++)
t -= MONTHSEC(mon, year);
mon--; /* back off one month */
t += MONTHSEC(mon, year);
sec = t % 60; /* seconds */
t /= 60;
min = t % 60; /* minutes */
t /= 60;
hour = t % 24; /* hours (24 hour format) */
day = t / 24; /* day of the month */
day++; /* adjust to start at 1 */
weekday = day % 7; /* not right, but it doesn't matter */
hsec = time.tv_usec / 10000;
CLKADDR->clk_cmd = (CLK_CMD_NORMAL & ~CLK_CMD_RUN);
CLKADDR->clk_weekday = weekday;
CLKADDR->clk_year = year;
CLKADDR->clk_mon = mon;
CLKADDR->clk_day = day;
CLKADDR->clk_hour = hour;
CLKADDR->clk_min = min;
CLKADDR->clk_sec = sec;
CLKADDR->clk_hsec = hsec;
CLKADDR->clk_cmd = CLK_CMD_NORMAL;
timedelta = 0; /* destroy any time delta */
tickdelta = tickadj; /* restore standard slew rate */
if (toddebug) {
printf("CLKSET (yr.mo.da.hr.mi.se.hs): %d.%d.%d.%d.%d.%d.%d\n",
year, mon, day, hour, min, sec, hsec);
(void) chkdeltat(0);
}
(void) splx(s);
}
static int jumpdeltat = 2147;
static u_char now[CLK_WEEKDAY+1];
#define TPRINTF if (toddebug) printf
#define DUMPTIME(x) TPRINTF(\
"Clock Values (yr.mo.da.hr.mi.se.hs): %d.%d.%d.%d.%d.%d.%d\n", \
(x)[CLK_YEAR], (x)[CLK_MON], (x)[CLK_DAY], (x)[CLK_HOUR], \
(x)[CLK_MIN], (x)[CLK_SEC], (x)[CLK_HSEC]);
static
chkdeltat(level)
{
struct timeval todget();
auto struct timeval tv;
register fail = 0;
tv = todget();
if (!tv.tv_sec && !tv.tv_usec) {
fail = 1; /* major failure 1 */
TPRINTF("todget rejects read of tod ");
} else if (ABS(tv.tv_sec-time.tv_sec) > jumpdeltat) {
fail = 1;
TPRINTF("Large Magnitude time change (cutoff %d): %d sec\n",
jumpdeltat, tv.tv_sec - time.tv_sec);
} else if (tv.tv_sec < time.tv_sec || (tv.tv_sec == time.tv_sec &&
tv.tv_usec < (time.tv_usec)-(2*tick))) {
fail = 1;
TPRINTF("Time is going backwards: new %d.%d old %d.%d\n",
tv.tv_sec, tv.tv_usec, time.tv_sec, time.tv_usec);
}
if (level > 0) {
if (fail) {
TPRINTF("Second Read of TOD Fails\n");
DUMPTIME(now);
if (fixtodjump) {
/*
* Supposedly, this will only happen
* if the chip read really fails.
* This was certainly the case for
* 3/50s for a while. By extension,
* 3/260s should have the same problem
* since they had the same circuit
* as the 3/50. I don't know about 3/60s,
* 3/110s and 3/160s.
*
* However, the when 4.0 alpha-3 came
* out, people reported seeing this
* message on a variety of systems.
* However, it didn't happen very often,
* and, as usual, they just complained
* about it, but weren't very helpful
* about pointing out which systems it
* happened on or cooperated about trying
* to nail it.
*
* So, I was in a quandary about to do do.
* I looked over the code again, think
* I understood what had changed since I
* first put this change in (3.4.1), and
* didn't see how this could happen, except
* when:
*
* 1) time was spent in the monitor or kadb
*
* 2) the chip actually *did* glitch.
*
* 3) > 60 seconds (jumpdeltat was that
* that value then) was spent in rewinding
* a sysgen cartridge tape during
* boot time when the scsi bus was being
* probed (known to be possible
* during installation).
*
* In order to solve this problem, I decided
* that
*
* a) jumpdeltat could be as close to the
* sign extension limit for the u-sec
* valued deltat. This value is approx.
* 2147 seconds, or nearly 35 minutes.
*
*
* b) I would turn off the warning message.
* If problems arise, it can be turned
* back on by an adb patch...
*
* matt jacob 9/20/87
*/
TPRINTF("WARNING: Time-of-Day chip glitch-\n");
TPRINTF(
"Resetting to internal tick time. Please check system date\n");
resettodr();
}
return (0);
} else {
TPRINTF("Second READ of TOD now shows sanity\n");
}
} else if (fail) {
TPRINTF("First Read of TOD chip shows insanity\n");
DUMPTIME(now);
return (chkdeltat(++level));
}
return (1000000 * (tv.tv_sec - time.tv_sec) +
(tv.tv_usec - time.tv_usec));
}
static
readtod(np)
u_char np[];
{
register i;
register u_char *cp = (u_char *)CLKADDR;
for (i = CLK_HSEC; i <= CLK_WEEKDAY+1; i++)
np[i] = *cp++;
}
/*
* Read the current time from the clock chip and convert to UNIX form.
* Assumes that the year in the counter chip is valid.
*/
struct timeval
todget()
{
struct timeval tv;
register int i, t = 0;
u_short year;
readtod(now);
if (now[CLK_MON] < 1 || now[CLK_MON] > 12 ||
now[CLK_DAY] < 1 || now[CLK_DAY] > 31 ||
now[CLK_WEEKDAY] > 6 || now[CLK_HOUR] > 23 ||
now[CLK_MIN] > 59 || now[CLK_SEC] > 59 ||
now[CLK_YEAR] < (YRREF - YRBASE)) { /* not initialized */
tv.tv_sec = 0;
tv.tv_usec = 0;
return (tv);
}
/*
* Add the number of seconds for each year onto our time t.
* We start at YRREF - YRBASE (which is the chip's value
* for UNIX's YRREF year), and count up to the year value given
* by the chip, adding each years seconds value to the Unix
* time value we are calculating.
*/
for (year = YRREF - YRBASE; year < now[CLK_YEAR]; year++)
t += SECYEAR(year);
/*
* Now add in the seconds for each month that has gone
* by this year, adjusting for leap year if appropriate.
*/
for (i = 1; i < now[CLK_MON]; i++)
t += MONTHSEC(i, year);
t += (now[CLK_DAY] - 1) * SECDAY;
t += now[CLK_HOUR] * (60*60);
t += now[CLK_MIN] * 60;
t += now[CLK_SEC];
/*
* If t is negative, assume bogus time
* (year was too large) and use 0 seconds.
* XXX - tv_sec and tv_usec should be unsigned.
*/
if (t < 0) {
tv.tv_sec = 0;
tv.tv_usec = 0;
} else {
tv.tv_sec = t;
tv.tv_usec = now[CLK_HSEC] * 10000;
}
return (tv);
}