327 lines
7.7 KiB
C
327 lines
7.7 KiB
C
/* $NetBSD: clock.c,v 1.3 2001/11/18 15:30:43 kleink Exp $ */
|
|
/* $OpenBSD: clock.c,v 1.3 1997/10/13 13:42:53 pefo Exp $ */
|
|
|
|
/*
|
|
* Copyright (C) 1995, 1996 Wolfgang Solfrank.
|
|
* Copyright (C) 1995, 1996 TooLs GmbH.
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* 3. All advertising materials mentioning features or use of this software
|
|
* must display the following acknowledgement:
|
|
* This product includes software developed by TooLs GmbH.
|
|
* 4. The name of TooLs GmbH may not be used to endorse or promote products
|
|
* derived from this software without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
|
|
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
|
|
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
|
|
* IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
|
|
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
|
|
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
|
|
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
|
|
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
|
|
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
|
|
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/kernel.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/device.h>
|
|
|
|
#include <dev/clock_subr.h>
|
|
|
|
#include <prep/prep/clockvar.h>
|
|
|
|
#define MINYEAR 1990
|
|
|
|
void decr_intr __P((struct clockframe *));
|
|
static inline u_quad_t mftb __P((void));
|
|
|
|
/*
|
|
* Initially we assume a processor with a bus frequency of 12.5 MHz.
|
|
*/
|
|
u_long ticks_per_sec;
|
|
u_long ns_per_tick;
|
|
static long ticks_per_intr;
|
|
static volatile u_long lasttb;
|
|
|
|
struct device *clockdev;
|
|
const struct clockfns *clockfns;
|
|
int clockinitted;
|
|
|
|
void
|
|
clockattach(dev, fns)
|
|
struct device *dev;
|
|
const struct clockfns *fns;
|
|
{
|
|
|
|
printf("\n");
|
|
|
|
if (clockfns != NULL)
|
|
panic("clockattach: multiple clocks");
|
|
|
|
clockdev = dev;
|
|
clockfns = fns;
|
|
}
|
|
|
|
/*
|
|
* Start the real-time and statistics clocks. Leave stathz 0 since there
|
|
* are no other timers available.
|
|
*/
|
|
void
|
|
cpu_initclocks()
|
|
{
|
|
|
|
ticks_per_intr = ticks_per_sec / hz;
|
|
asm volatile ("mftb %0" : "=r"(lasttb));
|
|
asm volatile ("mtdec %0" :: "r"(ticks_per_intr));
|
|
}
|
|
|
|
/*
|
|
* Initialize the time of day register, based on the time base which is, e.g.
|
|
* from a filesystem.
|
|
*/
|
|
void
|
|
inittodr(base)
|
|
time_t base;
|
|
{
|
|
struct clocktime ct;
|
|
int year;
|
|
struct clock_ymdhms dt;
|
|
time_t deltat;
|
|
int badbase = 0;
|
|
|
|
if (base < (MINYEAR - 1970) * SECYR) {
|
|
printf("WARNING: preposterous time in file system");
|
|
/* read the system clock anyway */
|
|
base = (MINYEAR - 1970) * SECYR + 186 * SECDAY + SECDAY / 2;
|
|
badbase = 1;
|
|
}
|
|
|
|
(*clockfns->cf_get)(clockdev, base, &ct);
|
|
#ifdef DEBUG
|
|
printf("readclock: %d/%d/%d/%d/%d/%d", ct.year, ct.mon, ct.day,
|
|
ct.hour, ct.min, ct.sec);
|
|
#endif
|
|
clockinitted = 1;
|
|
|
|
year = 1900 + ct.year;
|
|
if (year < 1970)
|
|
year += 100;
|
|
|
|
/* simple sanity checks (2037 = time_t overflow) */
|
|
if (year < MINYEAR || year > 2037 ||
|
|
ct.mon < 1 || ct.mon > 12 || ct.day < 1 ||
|
|
ct.day > 31 || ct.hour > 23 || ct.min > 59 || ct.sec > 59) {
|
|
/*
|
|
* Believe the time in the file system for lack of
|
|
* anything better, resetting the TODR.
|
|
*/
|
|
time.tv_sec = base;
|
|
if (!badbase) {
|
|
printf("WARNING: preposterous clock chip time\n");
|
|
resettodr();
|
|
}
|
|
goto bad;
|
|
}
|
|
|
|
dt.dt_year = year;
|
|
dt.dt_mon = ct.mon;
|
|
dt.dt_day = ct.day;
|
|
dt.dt_hour = ct.hour;
|
|
dt.dt_min = ct.min;
|
|
dt.dt_sec = ct.sec;
|
|
time.tv_sec = clock_ymdhms_to_secs(&dt);
|
|
#ifdef DEBUG
|
|
printf("=>%ld (%d)\n", (long int)time.tv_sec, (int)base);
|
|
#endif
|
|
|
|
if (!badbase) {
|
|
/*
|
|
* See if we gained/lost two or more days;
|
|
* if so, assume something is amiss.
|
|
*/
|
|
deltat = time.tv_sec - base;
|
|
if (deltat < 0)
|
|
deltat = -deltat;
|
|
if (deltat < 2 * SECDAY)
|
|
return;
|
|
printf("WARNING: clock %s %ld days",
|
|
time.tv_sec < base ? "lost" : "gained",
|
|
(long)deltat / SECDAY);
|
|
}
|
|
bad:
|
|
printf(" -- CHECK AND RESET THE DATE!\n");
|
|
}
|
|
|
|
/*
|
|
* Reset the TODR based on the time value; used when the TODR
|
|
* has a preposterous value and also when the time is reset
|
|
* by the stime system call. Also called when the TODR goes past
|
|
* TODRZERO + 100*(SECYEAR+2*SECDAY) (e.g. on Jan 2 just after midnight)
|
|
* to wrap the TODR around.
|
|
*/
|
|
void
|
|
resettodr()
|
|
{
|
|
struct clock_ymdhms dt;
|
|
struct clocktime ct;
|
|
|
|
if (!clockinitted)
|
|
return;
|
|
|
|
clock_secs_to_ymdhms(time.tv_sec, &dt);
|
|
|
|
/* rt clock wants 2 digits */
|
|
ct.year = dt.dt_year % 100;
|
|
ct.mon = dt.dt_mon;
|
|
ct.day = dt.dt_day;
|
|
ct.hour = dt.dt_hour;
|
|
ct.min = dt.dt_min;
|
|
ct.sec = dt.dt_sec;
|
|
ct.dow = dt.dt_wday;
|
|
#ifdef DEBUG
|
|
printf("setclock: %d/%d/%d/%d/%d/%d\n", ct.year, ct.mon, ct.day,
|
|
ct.hour, ct.min, ct.sec);
|
|
#endif
|
|
|
|
(*clockfns->cf_set)(clockdev, &ct);
|
|
}
|
|
|
|
/*
|
|
* We assume newhz is either stathz or profhz, and that neither will
|
|
* change after being set up above. Could recalculate intervals here
|
|
* but that would be a drag.
|
|
*/
|
|
void
|
|
setstatclockrate(arg)
|
|
int arg;
|
|
{
|
|
|
|
/* Nothing we can do */
|
|
}
|
|
|
|
void
|
|
decr_intr(frame)
|
|
struct clockframe *frame;
|
|
{
|
|
int msr;
|
|
int pri;
|
|
u_long tb;
|
|
long tick;
|
|
int nticks;
|
|
extern long intrcnt[];
|
|
|
|
/*
|
|
* Check whether we are initialized.
|
|
*/
|
|
if (!ticks_per_intr)
|
|
return;
|
|
|
|
/*
|
|
* Based on the actual time delay since the last decrementer reload,
|
|
* we arrange for earlier interrupt next time.
|
|
*/
|
|
asm ("mftb %0; mfdec %1" : "=r"(tb), "=r"(tick));
|
|
for (nticks = 0; tick < 0; nticks++)
|
|
tick += ticks_per_intr;
|
|
asm volatile ("mtdec %0" :: "r"(tick));
|
|
|
|
/*
|
|
* lasttb is used during microtime. Set it to the virtual
|
|
* start of this tick interval.
|
|
*/
|
|
lasttb = tb + tick - ticks_per_intr;
|
|
|
|
intrcnt[CNT_CLOCK]++;
|
|
|
|
pri = splclock();
|
|
if (pri & SPL_CLOCK)
|
|
tickspending += nticks;
|
|
else {
|
|
nticks += tickspending;
|
|
tickspending = 0;
|
|
|
|
/*
|
|
* Reenable interrupts
|
|
*/
|
|
asm volatile ("mfmsr %0; ori %0, %0, %1; mtmsr %0"
|
|
: "=r"(msr) : "K"(PSL_EE));
|
|
|
|
/*
|
|
* Do standard timer interrupt stuff.
|
|
* Do softclock stuff only on the last iteration.
|
|
*/
|
|
frame->pri = pri | SINT_CLOCK;
|
|
while (--nticks > 0)
|
|
hardclock(frame);
|
|
frame->pri = pri;
|
|
hardclock(frame);
|
|
}
|
|
splx(pri);
|
|
}
|
|
|
|
static inline u_quad_t
|
|
mftb()
|
|
{
|
|
u_long scratch;
|
|
u_quad_t tb;
|
|
|
|
asm ("1: mftbu %0; mftb %0+1; mftbu %1; cmpw %0,%1; bne 1b"
|
|
: "=r"(tb), "=r"(scratch));
|
|
return tb;
|
|
}
|
|
|
|
/*
|
|
* Fill in *tvp with current time with microsecond resolution.
|
|
*/
|
|
void
|
|
microtime(tvp)
|
|
struct timeval *tvp;
|
|
{
|
|
u_long tb;
|
|
u_long ticks;
|
|
int msr, scratch;
|
|
|
|
asm volatile ("mfmsr %0; andi. %1,%0,%2; mtmsr %1"
|
|
: "=r"(msr), "=r"(scratch) : "K"((u_short)~PSL_EE));
|
|
asm ("mftb %0" : "=r"(tb));
|
|
ticks = (tb - lasttb) * ns_per_tick;
|
|
*tvp = time;
|
|
asm volatile ("mtmsr %0" :: "r"(msr));
|
|
ticks /= 1000;
|
|
tvp->tv_usec += ticks;
|
|
while (tvp->tv_usec >= 1000000) {
|
|
tvp->tv_usec -= 1000000;
|
|
tvp->tv_sec++;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Wait for about n microseconds (at least!).
|
|
*/
|
|
void
|
|
delay(n)
|
|
unsigned int n;
|
|
{
|
|
u_quad_t tb;
|
|
u_long tbh, tbl, scratch;
|
|
|
|
tb = mftb();
|
|
tb += (n * 1000 + ns_per_tick - 1) / ns_per_tick;
|
|
tbh = tb >> 32;
|
|
tbl = tb;
|
|
asm volatile ("1: mftbu %0; cmplw %0,%1; blt 1b; bgt 2f;"
|
|
"mftb %0; cmplw %0,%2; blt 1b; 2:"
|
|
: "=r"(scratch) : "r"(tbh), "r"(tbl));
|
|
}
|