2021-10-11 18:20:23 -03:00

586 lines
15 KiB
C

#ifndef lint
static char sccsid[] = "@(#)clock.c 1.1 92/07/30 SMI";
#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>
#include <machine/cpu.h>
struct timeval todget();
/*
* Defines for conversion between binary and bcd representation. These are
* necessary for the Mostek 48T02 TOD clock regs. (Works only on 8 bit
* unsigned values.)
*/
#define bcdtob(x) (((x) & 0xf) + 10 * ((x) >> 4))
#define btobcd(x) ((((x) / 10) << 4) + ((x) % 10))
int clock_type = 0;
/*
* 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");
/*
* Determine the clock type (intersil7170 vs mostek48t02). Attempt to
* read a register on the intersil 7170.
*/
#ifndef SAS
#ifdef SUN3X_80
/* XXX Hardware problem, 3X/80 can't tell if a INTERSIL7170 exists */
if (cpu == CPU_SUN3X_80)
clock_type = MOSTEK48T02;
else
#endif /* SUN3X_80 */
if (peekc((char *) CLKADDR) != -1) {
clock_type = INTERSIL7170;
/* set 1/100 sec clock intr */
CLKADDR->clk_intrreg = CLK_INT_HSEC;
} else {
/* machine using this clock will set 1/100 sec clock intr */
clock_type = MOSTEK48T02;
}
#endif /* !SAS */
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);
#ifndef SAS
if (clock_type == INTERSIL7170) {
CLKADDR->clk_cmd = (CLK_CMD_NORMAL & ~CLK_CMD_INTRENA);
dummy = CLKADDR->clk_intrreg; /* clear clock */
}
#endif /* !SAS */
#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 */
#ifndef SAS
if (clock_type == INTERSIL7170) {
CLKADDR->clk_cmd = CLK_CMD_NORMAL; /* enable clock intr */
}
#endif /* !SAS */
*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 */
/*
* Commented out since it's not used in 3x, and lint complains. 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))
int todsyncat = 0;
synctodr()
{
struct timeval tv;
int deltat, s;
int sch = synctodrval * hz - 2;
/*
* If timedelta is non-zero, assume someone who knows better is
* already adjusting the time. Don't assume that this nice person is
* going to hang around forever, tho.
*/
if (dosynctodr && timedelta == 0 && doresettodr == 0) {
s = splclock();
tv = todget();
/*
* Sorry about the gotos, but in this case they are more
* clear than nested conditionals or a do { ... } while (0);
* construct with multiple break statements, or replication
* of the splx() and timeout() code. All of the gotos here
* branch down to the bottom of the current conditional, just
* above where the priority is restored.
*/
/*
* Several machines have clock chips that only give us one
* second of precision; for them, we must hang out until the
* clock changes. When this happens, we can assume we are
* near (within 10ms) the beginning of the second, and apply
* the normal algorithm.
*
* Systems with higher precision clocks are not hurt by having
* this run, since the overhead is nearly zero, so we just go
* ahead and do it everywhere.
*/
if (!todsyncat)
todsyncat = tv.tv_sec;
if (todsyncat == tv.tv_sec) {
sch = 1;
goto bottom;
}
/*
* Sanity check: if todget is returning zeros, bitch and turn
* off clock synchronization. The old code would flail about
* madly.
*/
if (tv.tv_sec == 0) {
printf("synctodr: unable to read clock chip\n");
dosynctodr = 0;
goto bottom;
}
/*
* Sanity check: if the two clocks are out of sync by more
* than about 2000 seconds, complain and turn off sync;
* continuing would result in integer overflows resulting in
* synchronizing to the wrong time.
*/
deltat = tv.tv_sec - time.tv_sec;
if (ABS(deltat) > 2000) {
printf("synctodr: unable to sync\n");
dosynctodr = 0;
goto bottom;
}
/*
* Calculate how far off we are. If we are out by more than
* one clock tick, set up timedelta and tickdelta so that
* hardclock() will increment the software clock a bit fast
* or a bit slow. How fast or how slow is determined by
* tickadj, the number of microseconds of correction applied
* each tick.
*/
deltat = deltat * 1000000 + tv.tv_usec - time.tv_usec;
if (ABS(deltat) > 1000000 / hz) {
timedelta = deltat;
tickdelta = tickadj; /* standard slew rate */
if (clkdrift)
printf("<[%d]> ", deltat / 1000);
}
todsyncat = 0;
bottom:
(void) splx(s);
}
timeout(synctodr, (caddr_t) 0, sch);
}
/*
* 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();
t = time.tv_sec;
/*
* Figure out the weekday
*/
weekday = (t / (60 * 60 * 24) + 2) % 7 + 1; /* 1..7 */
/*
* Figure out the (adjusted) year
*/
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 */
hsec = time.tv_usec / 10000;
#ifndef SAS
if (clock_type == INTERSIL7170) {
CLKADDR->clk_cmd = (CLK_CMD_NORMAL & ~CLK_CMD_RUN);
CLKADDR->clk_weekday = weekday % 7; /* 0..6 */
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;
} else if (clock_type == MOSTEK48T02) {
CLK1ADDR->clk_ctrl |= CLK_CTRL_WRITE;
CLK1ADDR->clk_sec = btobcd(sec) & CLK_SEC_MASK;
CLK1ADDR->clk_min = btobcd(min) & CLK_MIN_MASK;
CLK1ADDR->clk_hour = btobcd(hour) & CLK_HOUR_MASK;
CLK1ADDR->clk_weekday = btobcd(weekday) & CLK_WEEKDAY_MASK;
CLK1ADDR->clk_day = btobcd(day) & CLK_DAY_MASK;
CLK1ADDR->clk_month = btobcd(mon) & CLK_MONTH_MASK;
CLK1ADDR->clk_year = btobcd(year);
CLK1ADDR->clk_ctrl &= ~CLK_CTRL_WRITE;
}
#endif /* !SAS */
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 char *glitchstr = "WARNING: Time-of-Day Chip glitch-\n\
Resetting to internal tick time.\n\
Please check System date";
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, then 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(glitchstr);
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;
#ifndef SAS
if (clock_type == INTERSIL7170) {
for (i = CLK_HSEC; i <= CLK_WEEKDAY + 1; i++)
np[i] = *cp++;
} else if (clock_type == MOSTEK48T02) {
CLK1ADDR->clk_ctrl |= CLK_CTRL_READ;
now[CLK_HSEC] = 0; /* XXX perhaps look at a counter ? */
now[CLK_HOUR] = bcdtob(CLK1ADDR->clk_hour);
now[CLK_MIN] = bcdtob(CLK1ADDR->clk_min);
now[CLK_SEC] = bcdtob(CLK1ADDR->clk_sec);
now[CLK_MON] = bcdtob(CLK1ADDR->clk_month);
now[CLK_DAY] = bcdtob(CLK1ADDR->clk_day);
now[CLK_YEAR] = bcdtob(CLK1ADDR->clk_year);
now[CLK_WEEKDAY] = bcdtob(CLK1ADDR->clk_weekday);
CLK1ADDR->clk_ctrl &= ~CLK_CTRL_READ;
}
#endif /* !SAS */
}
/*
* 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] > 7 || 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);
}