676 lines
18 KiB
C
676 lines
18 KiB
C
/* $NetBSD: clock.c,v 1.4 2000/01/19 02:52:17 msaitoh Exp $ */
|
|
|
|
/*
|
|
* Copyright 1997
|
|
* Digital Equipment Corporation. All rights reserved.
|
|
*
|
|
* This software is furnished under license and may be used and
|
|
* copied only in accordance with the following terms and conditions.
|
|
* Subject to these conditions, you may download, copy, install,
|
|
* use, modify and distribute this software in source and/or binary
|
|
* form. No title or ownership is transferred hereby.
|
|
*
|
|
* 1) Any source code used, modified or distributed must reproduce
|
|
* and retain this copyright notice and list of conditions as
|
|
* they appear in the source file.
|
|
*
|
|
* 2) No right is granted to use any trade name, trademark, or logo of
|
|
* Digital Equipment Corporation. Neither the "Digital Equipment
|
|
* Corporation" name nor any trademark or logo of Digital Equipment
|
|
* Corporation may be used to endorse or promote products derived
|
|
* from this software without the prior written permission of
|
|
* Digital Equipment Corporation.
|
|
*
|
|
* 3) This software is provided "AS-IS" and any express or implied
|
|
* warranties, including but not limited to, any implied warranties
|
|
* of merchantability, fitness for a particular purpose, or
|
|
* non-infringement are disclaimed. In no event shall DIGITAL be
|
|
* liable for any damages whatsoever, and in particular, DIGITAL
|
|
* shall not be liable for special, indirect, consequential, or
|
|
* incidental damages or damages for lost profits, loss of
|
|
* revenue or loss of use, whether such damages arise in contract,
|
|
* negligence, tort, under statute, in equity, at law or otherwise,
|
|
* even if advised of the possibility of such damage.
|
|
*/
|
|
|
|
/*-
|
|
* Copyright (c) 1993, 1994 Charles M. Hannum.
|
|
* Copyright (c) 1990 The Regents of the University of California.
|
|
* All rights reserved.
|
|
*
|
|
* This code is derived from software contributed to Berkeley by
|
|
* William Jolitz and Don Ahn.
|
|
*
|
|
* 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 the University of
|
|
* California, Berkeley and its contributors.
|
|
* 4. Neither the name of the University nor the names of its contributors
|
|
* may be used to endorse or promote products derived from this software
|
|
* without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 THE REGENTS OR CONTRIBUTORS 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.
|
|
*
|
|
* @(#)clock.c 7.2 (Berkeley) 5/12/91
|
|
*/
|
|
/*
|
|
* Mach Operating System
|
|
* Copyright (c) 1991,1990,1989 Carnegie Mellon University
|
|
* All Rights Reserved.
|
|
*
|
|
* Permission to use, copy, modify and distribute this software and its
|
|
* documentation is hereby granted, provided that both the copyright
|
|
* notice and this permission notice appear in all copies of the
|
|
* software, derivative works or modified versions, and any portions
|
|
* thereof, and that both notices appear in supporting documentation.
|
|
*
|
|
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
|
|
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
|
|
* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
|
|
*
|
|
* Carnegie Mellon requests users of this software to return to
|
|
*
|
|
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
|
|
* School of Computer Science
|
|
* Carnegie Mellon University
|
|
* Pittsburgh PA 15213-3890
|
|
*
|
|
* any improvements or extensions that they make and grant Carnegie Mellon
|
|
* the rights to redistribute these changes.
|
|
*/
|
|
/*
|
|
Copyright 1988, 1989 by Intel Corporation, Santa Clara, California.
|
|
|
|
All Rights Reserved
|
|
|
|
Permission to use, copy, modify, and distribute this software and
|
|
its documentation for any purpose and without fee is hereby
|
|
granted, provided that the above copyright notice appears in all
|
|
copies and that both the copyright notice and this permission notice
|
|
appear in supporting documentation, and that the name of Intel
|
|
not be used in advertising or publicity pertaining to distribution
|
|
of the software without specific, written prior permission.
|
|
|
|
INTEL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE
|
|
INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS,
|
|
IN NO EVENT SHALL INTEL BE LIABLE FOR ANY SPECIAL, INDIRECT, OR
|
|
CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
|
|
LOSS OF USE, DATA OR PROFITS, WHETHER IN ACTION OF CONTRACT,
|
|
NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
|
|
WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
|
|
*/
|
|
|
|
/*
|
|
* Primitive clock interrupt routines.
|
|
*/
|
|
#include <sys/param.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/time.h>
|
|
#include <sys/kernel.h>
|
|
#include <sys/device.h>
|
|
|
|
#include <machine/cpu.h>
|
|
#include <machine/irqhandler.h>
|
|
#include <machine/pio.h>
|
|
#include <machine/cpufunc.h>
|
|
|
|
#include <dev/isa/isareg.h>
|
|
#include <dev/isa/isavar.h>
|
|
#include <dev/ic/mc146818reg.h>
|
|
#include <arm32/isa/nvram.h>
|
|
#include <arm32/isa/timerreg.h>
|
|
#include <arm32/isa/spkrreg.h>
|
|
|
|
#ifdef SHARK
|
|
#include <arm32/shark/hat.h>
|
|
#endif
|
|
|
|
void sysbeepstop __P((void *));
|
|
void sysbeep __P((int, int));
|
|
void rtcinit __P((void));
|
|
int timer_hz_to_count(int);
|
|
|
|
static void findcpuspeed __P((void));
|
|
static void init_isa_timer_tables();
|
|
static void delayloop(int);
|
|
static int clockintr __P((void *));
|
|
static int gettick __P((void));
|
|
|
|
__inline u_int mc146818_read __P((void *, u_int));
|
|
__inline void mc146818_write __P((void *, u_int, u_int));
|
|
|
|
#define SECMIN ((unsigned)60) /* seconds per minute */
|
|
#define SECHOUR ((unsigned)(60*SECMIN)) /* seconds per hour */
|
|
#define SECDAY ((unsigned)(24*SECHOUR)) /* seconds per day */
|
|
#define SECYR ((unsigned)(365*SECDAY)) /* seconds per common year */
|
|
|
|
__inline u_int
|
|
mc146818_read(sc, reg)
|
|
void *sc; /* XXX use it? */
|
|
u_int reg;
|
|
{
|
|
|
|
outb(IO_RTC, reg);
|
|
return (inb(IO_RTC+1));
|
|
}
|
|
|
|
__inline void
|
|
mc146818_write(sc, reg, datum)
|
|
void *sc; /* XXX use it? */
|
|
u_int reg, datum;
|
|
{
|
|
|
|
outb(IO_RTC, reg);
|
|
outb(IO_RTC+1, datum);
|
|
}
|
|
|
|
unsigned int count1024usec; /* calibrated loop variable (1024 microseconds) */
|
|
|
|
/* number of timer ticks in a Musec = 2^20 usecs */
|
|
#define TIMER_MUSECFREQ\
|
|
(((((((TIMER_FREQ) * 1024) + 999) / 1000) * 1024) + 999) / 1000)
|
|
#define TIMER_MUSECDIV(x) ((TIMER_MUSECFREQ+(x)/2)/(x))
|
|
|
|
/*
|
|
* microtime() makes use of the following globals.
|
|
* timer_msb_table[] and timer_lsb_table[] are used to compute the
|
|
* microsecond increment.
|
|
*
|
|
* time.tv_usec += isa_timer_msb_table[cnt_msb] + isa_timer_lsb_table[cnt_lsb];
|
|
*/
|
|
|
|
u_short isa_timer_msb_table[256]; /* timer->usec MSB */
|
|
u_short isa_timer_lsb_table[256]; /* timer->usec conversion for LSB */
|
|
|
|
/* 64 bit counts from timer 0 */
|
|
struct count64 {
|
|
unsigned lo; /* low 32 bits */
|
|
unsigned hi; /* high 32 bits */
|
|
};
|
|
|
|
#define TIMER0_ROLLOVER 0xFFFF /* maximum rollover for 8254 counter */
|
|
|
|
struct count64 timer0count;
|
|
struct count64 timer0_at_last_clockintr;
|
|
unsigned timer0last;
|
|
|
|
/*#define TESTHAT*/
|
|
#ifdef TESTHAT
|
|
#define HATSTACKSIZE 1024
|
|
#define HATHZ 50000
|
|
#define HATHZ2 10000
|
|
unsigned char hatStack[HATSTACKSIZE];
|
|
|
|
unsigned testHatOn = 0;
|
|
unsigned nHats = 0;
|
|
unsigned nHatWedges = 0;
|
|
unsigned fiqReason = 0;
|
|
unsigned hatCount = 0;
|
|
unsigned hatCount2 = 0;
|
|
|
|
void hatTest(int testReason)
|
|
{
|
|
fiqReason |= testReason;
|
|
nHats++;
|
|
|
|
}
|
|
|
|
void hatWedge(int nFIQs)
|
|
{
|
|
printf("Unwedging the HAT. fiqs_happened = %d\n", nFIQs);
|
|
nHatWedges++;
|
|
}
|
|
#endif
|
|
|
|
void
|
|
startrtclock()
|
|
{
|
|
findcpuspeed(); /* use the clock (while it's free)
|
|
to find the cpu speed */
|
|
|
|
init_isa_timer_tables();
|
|
|
|
timer0count.lo = 0;
|
|
timer0count.hi = 0;
|
|
timer0_at_last_clockintr.lo = 0;
|
|
timer0_at_last_clockintr.hi = 0;
|
|
timer0last = 0;
|
|
|
|
/* initialize 8253 clock */
|
|
outb(TIMER_MODE, TIMER_SEL0|TIMER_RATEGEN|TIMER_16BIT);
|
|
outb(TIMER_CNTR0, TIMER0_ROLLOVER % 256);
|
|
outb(TIMER_CNTR0, TIMER0_ROLLOVER / 256);
|
|
|
|
#ifdef TESTHAT
|
|
hatCount = timer_hz_to_count(HATHZ);
|
|
hatCount2 = timer_hz_to_count(HATHZ2);
|
|
printf("HAT test on @ %d Hz = %d ticks\n", HATHZ, hatCount);
|
|
#endif
|
|
}
|
|
|
|
static void
|
|
init_isa_timer_tables()
|
|
{
|
|
int s;
|
|
u_long t, msbmillion, quotient, remainder;
|
|
|
|
for (s = 0; s < 256; s++) {
|
|
/* LSB table is easy, just divide and round */
|
|
t = ((u_long) s * 1000000 * 2) / TIMER_FREQ;
|
|
isa_timer_lsb_table[s] = (u_short) ((t / 2) + (t & 0x1));
|
|
|
|
msbmillion = s * 1000000;
|
|
quotient = msbmillion / TIMER_FREQ;
|
|
remainder = msbmillion % TIMER_FREQ;
|
|
t = (remainder * 256 * 2) / TIMER_FREQ;
|
|
isa_timer_msb_table[s] =
|
|
(u_short)((t / 2) + (t & 1) + (quotient * 256));
|
|
|
|
#ifdef DIAGNOSTIC
|
|
if ((s > 0) &&
|
|
(isa_timer_msb_table[s] <
|
|
(isa_timer_msb_table[s - 1] + isa_timer_lsb_table[0xFF])))
|
|
panic ("time tables not monotonic %d: %d < (%d + %d) = %d\n",
|
|
s, isa_timer_msb_table[s],
|
|
isa_timer_msb_table[s - 1],
|
|
isa_timer_lsb_table[0xFF],
|
|
isa_timer_msb_table[s - 1] +
|
|
isa_timer_lsb_table[0xFF]);
|
|
#endif
|
|
} /* END for */
|
|
}
|
|
|
|
int
|
|
timer_hz_to_count(timer_hz)
|
|
int timer_hz;
|
|
{
|
|
u_long tval;
|
|
|
|
tval = (TIMER_FREQ * 2) / (u_long) timer_hz;
|
|
tval = (tval / 2) + (tval & 0x1);
|
|
|
|
return (int)tval;
|
|
|
|
}
|
|
|
|
/* must be called at SPL_CLOCK or higher */
|
|
void gettimer0count(pcount)
|
|
struct count64 *pcount;
|
|
{
|
|
unsigned current, ticks, oldlo;
|
|
|
|
/*
|
|
* Latch the current value of the timer and then read it.
|
|
* This guarentees an atomic reading of the time.
|
|
*/
|
|
|
|
current = gettick();
|
|
|
|
if (timer0last >= current)
|
|
ticks = timer0last - current;
|
|
else
|
|
ticks = timer0last + (TIMER0_ROLLOVER - current);
|
|
|
|
timer0last = current;
|
|
|
|
oldlo = timer0count.lo;
|
|
|
|
if (oldlo > (timer0count.lo = oldlo + ticks)) /* carry? */
|
|
timer0count.hi++;
|
|
|
|
*pcount = timer0count;
|
|
}
|
|
|
|
static int
|
|
clockintr(arg)
|
|
void *arg;
|
|
{
|
|
struct clockframe *frame = arg; /* not strictly necessary */
|
|
extern void isa_specific_eoi(int irq);
|
|
#ifdef TESTHAT
|
|
static int ticks = 0;
|
|
#endif
|
|
#ifdef SHARK
|
|
static int hatUnwedgeCtr = 0;
|
|
#endif
|
|
|
|
gettimer0count(&timer0_at_last_clockintr);
|
|
|
|
mc146818_read(NULL, MC_REGC); /* clear the clock interrupt */
|
|
|
|
#ifdef SHARK
|
|
/* check to see if the high-availability timer needs to be unwedged */
|
|
if (++hatUnwedgeCtr >= (hz / HAT_MIN_FREQ)) {
|
|
hatUnwedgeCtr = 0;
|
|
hatUnwedge();
|
|
}
|
|
#endif
|
|
|
|
#ifdef TESTHAT
|
|
++ticks;
|
|
|
|
if (testHatOn && ((ticks & 0x3f) == 0)) {
|
|
if (testHatOn == 1) {
|
|
hatClkAdjust(hatCount2);
|
|
testHatOn = 2;
|
|
} else {
|
|
testHatOn = 0;
|
|
hatClkOff();
|
|
printf("hat off status: %d %d %x\n", nHats, nHatWedges, fiqReason);
|
|
}
|
|
} else if (!testHatOn && (ticks & 0x1ff) == 0) {
|
|
printf("hat on status: %d %d %x\n", nHats, nHatWedges, fiqReason);
|
|
testHatOn = 1;
|
|
nHats = 0;
|
|
fiqReason = 0;
|
|
hatClkOn(hatCount, hatTest, 0xfeedface,
|
|
hatStack + HATSTACKSIZE - sizeof(unsigned),
|
|
hatWedge);
|
|
}
|
|
#endif
|
|
hardclock(frame);
|
|
return(0);
|
|
}
|
|
|
|
static int
|
|
gettick()
|
|
{
|
|
u_char lo, hi;
|
|
u_int savedints;
|
|
|
|
/* Don't want someone screwing with the counter while we're here. */
|
|
savedints = disable_interrupts(I32_bit);
|
|
/* Select counter 0 and latch it. */
|
|
outb(TIMER_MODE, TIMER_SEL0 | TIMER_LATCH);
|
|
lo = inb(TIMER_CNTR0);
|
|
hi = inb(TIMER_CNTR0);
|
|
restore_interrupts(savedints);
|
|
return ((hi << 8) | lo);
|
|
}
|
|
|
|
/* modifications from i386 to arm32 isa version:
|
|
- removed hardcoded "n -=" values that approximated the time to
|
|
calculate delay ticks
|
|
- made the time to calculate delay ticks almost negligable. 4 multiplies
|
|
= maximum of 12 cycles = 75ns on a slow SA-110, plus a bunch of shifts;
|
|
as opposed to 4 multiplies plus a bunch of divides.
|
|
- removed i386 assembly language hack
|
|
- put code in findcpuspeed that works even if FIRST_GUESS is orders
|
|
of magnitude low
|
|
- put code in delay() to use delayloop() for short delays
|
|
- microtime no longer in assembly language
|
|
*/
|
|
|
|
/*
|
|
* Wait "n" microseconds.
|
|
* Relies on timer 1 counting down from (TIMER_FREQ / hz) at TIMER_FREQ Hz.
|
|
* Note: timer had better have been programmed before this is first used!
|
|
* (Note that we use `rate generator' mode, which counts at 1:1; `square
|
|
* wave' mode counts at 2:1).
|
|
*/
|
|
void
|
|
delay(n)
|
|
unsigned n;
|
|
{
|
|
int tick, otick;
|
|
int nticks;
|
|
|
|
if (n < 100) {
|
|
/* it can take a long time (1 usec or longer) just for 1 ISA read,
|
|
so it's best not to use the timer for short delays */
|
|
delayloop((n * count1024usec) >> 10);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Read the counter first, so that the rest of the setup overhead is
|
|
* counted.
|
|
*/
|
|
otick = gettick();
|
|
|
|
/*
|
|
* Calculate ((n * TIMER_FREQ) / 1e6) without using floating point and
|
|
* without any avoidable overflows.
|
|
*/
|
|
{
|
|
/* a Musec = 2^20 usec */
|
|
int Musec = n >> 20,
|
|
usec = n & ((1 << 20) - 1);
|
|
nticks
|
|
= (Musec * TIMER_MUSECFREQ) +
|
|
(usec * (TIMER_MUSECFREQ >> 20)) +
|
|
((usec * ((TIMER_MUSECFREQ & ((1 <<20) - 1)) >>10)) >>10) +
|
|
((usec * (TIMER_MUSECFREQ & ((1 << 10) - 1))) >> 20);
|
|
}
|
|
|
|
while (nticks > 0) {
|
|
tick = gettick();
|
|
if (tick > otick)
|
|
nticks -= TIMER0_ROLLOVER - (tick - otick);
|
|
else
|
|
nticks -= otick - tick;
|
|
otick = tick;
|
|
}
|
|
|
|
}
|
|
|
|
void
|
|
sysbeepstop(arg)
|
|
void *arg;
|
|
{
|
|
}
|
|
|
|
void
|
|
sysbeep(pitch, period)
|
|
int pitch, period;
|
|
{
|
|
}
|
|
|
|
#define FIRST_GUESS 0x2000
|
|
|
|
static void
|
|
findcpuspeed()
|
|
{
|
|
int ticks;
|
|
unsigned int guess = FIRST_GUESS;
|
|
|
|
while (1) { /* loop until accurate enough */
|
|
/* Put counter in count down mode */
|
|
outb(TIMER_MODE, TIMER_SEL0 | TIMER_16BIT | TIMER_RATEGEN);
|
|
outb(TIMER_CNTR0, 0xff);
|
|
outb(TIMER_CNTR0, 0xff);
|
|
delayloop(guess);
|
|
|
|
/* Read the value left in the counter */
|
|
/*
|
|
* Formula for delaycount is:
|
|
* (loopcount * timer clock speed) / (counter ticks * 1000)
|
|
*/
|
|
ticks = 0xFFFF - gettick();
|
|
if (ticks == 0) ticks = 1; /* just in case */
|
|
if (ticks < (TIMER_MUSECDIV(1024))) { /* not accurate enough */
|
|
guess *= max(2, (TIMER_MUSECDIV(1024) / ticks));
|
|
continue;
|
|
}
|
|
count1024usec = (guess * (TIMER_MUSECDIV(1024))) / ticks;
|
|
return;
|
|
}
|
|
}
|
|
|
|
static void
|
|
delayloop(counts)
|
|
{
|
|
while (counts--);
|
|
}
|
|
|
|
void
|
|
cpu_initclocks()
|
|
{
|
|
unsigned hzval;
|
|
|
|
printf("clock: hz=%d stathz = %d profhz = %d\n", hz, stathz, profhz);
|
|
|
|
/* install RTC interrupt handler */
|
|
(void)isa_intr_establish(NULL, IRQ_RTC, IST_LEVEL, IPL_CLOCK,
|
|
clockintr, 0);
|
|
|
|
/* code for values of hz that don't divide 1000000 exactly */
|
|
tickfix = 1000000 - (hz * tick);
|
|
if (tickfix) {
|
|
int ftp;
|
|
|
|
ftp = min(ffs(tickfix), ffs(hz));
|
|
tickfix >>= (ftp - 1);
|
|
tickfixinterval = hz >> (ftp - 1);
|
|
}
|
|
|
|
/* set up periodic interrupt @ hz
|
|
this is the subset of hz values in kern_clock.c that are
|
|
supported by the ISA RTC */
|
|
switch (hz) {
|
|
case 64:
|
|
hzval = MC_RATE_64_Hz;
|
|
break;
|
|
case 128:
|
|
hzval = MC_RATE_128_Hz;
|
|
break;
|
|
case 256:
|
|
hzval = MC_RATE_256_Hz;
|
|
break;
|
|
case 1024:
|
|
hzval = MC_RATE_1024_Hz;
|
|
break;
|
|
default:
|
|
panic("cannot configure hz = %d\n", hz);
|
|
}
|
|
|
|
rtcinit(); /* make sure basics are done by now */
|
|
|
|
/* blast values to set up clock interrupt */
|
|
mc146818_write(NULL, MC_REGA, MC_BASE_32_KHz | hzval);
|
|
/* enable periodic interrupt */
|
|
mc146818_write(NULL, MC_REGB,
|
|
mc146818_read(NULL, MC_REGB) | MC_REGB_PIE);
|
|
}
|
|
|
|
void
|
|
rtcinit()
|
|
{
|
|
static int first_rtcopen_ever = 1;
|
|
|
|
if (!first_rtcopen_ever)
|
|
return;
|
|
first_rtcopen_ever = 0;
|
|
|
|
mc146818_write(NULL, MC_REGA, /* XXX softc */
|
|
MC_BASE_32_KHz | MC_RATE_1024_Hz);
|
|
mc146818_write(NULL, MC_REGB, MC_REGB_24HR); /* XXX softc */
|
|
}
|
|
|
|
void
|
|
setstatclockrate(arg)
|
|
int arg;
|
|
{
|
|
}
|
|
|
|
/*
|
|
* void microtime(struct timeval *tvp)
|
|
*
|
|
* Fill in the specified timeval struct with the current time
|
|
* accurate to the microsecond.
|
|
*/
|
|
|
|
void
|
|
microtime(tvp)
|
|
struct timeval *tvp;
|
|
{
|
|
int s;
|
|
unsigned lsb, msb;
|
|
int tm;
|
|
static struct timeval oldtv;
|
|
struct count64 timer0current;
|
|
int ticks;
|
|
|
|
s = splstatclock();
|
|
|
|
gettimer0count(&timer0current);
|
|
|
|
tm = time.tv_usec;
|
|
|
|
/* unsigned arithmetic should take care of overflow */
|
|
/* with a >= 32 Hz clock, ticks will always be < 0x7FFF */
|
|
ticks = (int)((unsigned)
|
|
(timer0current.lo - timer0_at_last_clockintr.lo));
|
|
|
|
#ifdef DIAGNOSTIC
|
|
if ((ticks < 0) || (ticks > 0xffff))
|
|
printf("microtime bug: ticks = %x\n", ticks);
|
|
#endif
|
|
|
|
while (ticks > 0) {
|
|
|
|
if (ticks < 0xffff) {
|
|
msb = (ticks >> 8) & 0xFF;
|
|
lsb = ticks & 0xFF;
|
|
} else {
|
|
msb = 0xff;
|
|
lsb = 0xff;
|
|
}
|
|
|
|
/* see comments above */
|
|
tm += isa_timer_msb_table[msb] + isa_timer_lsb_table[lsb];
|
|
|
|
/* for a 64 Hz RTC, ticks will never overflow table */
|
|
/* microtime will be less accurate if the RTC is < 36 Hz */
|
|
ticks -= 0xffff;
|
|
}
|
|
|
|
tvp->tv_sec = time.tv_sec;
|
|
if (tm >= 1000000) {
|
|
tvp->tv_sec += 1;
|
|
tm -= 1000000;
|
|
}
|
|
|
|
tvp->tv_usec = tm;
|
|
|
|
/* Make sure the time has advanced. */
|
|
|
|
if (tvp->tv_sec == oldtv.tv_sec &&
|
|
tvp->tv_usec <= oldtv.tv_usec) {
|
|
tvp->tv_usec = oldtv.tv_usec + 1;
|
|
if (tvp->tv_usec >= 1000000) {
|
|
tvp->tv_usec -= 1000000;
|
|
++tvp->tv_sec;
|
|
}
|
|
}
|
|
|
|
oldtv = *tvp;
|
|
(void)splx(s);
|
|
}
|
|
|
|
void
|
|
need_proftick(p)
|
|
struct proc *p;
|
|
{
|
|
}
|
|
|
|
/* End of clock.c */
|