NetBSD/sys/arch/x68k/x68k/clock.c
1996-05-15 16:12:48 +00:00

498 lines
12 KiB
C

/* $NetBSD: clock.c,v 1.2 1996/05/15 16:12:48 oki Exp $ */
/*
* Copyright (c) 1988 University of Utah.
* Copyright (c) 1982, 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* the Systems Programming Group of the University of Utah Computer
* Science Department.
*
* 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.
*
* from: Utah $Hdr: clock.c 1.18 91/01/21$
*
* @(#)clock.c 8.2 (Berkeley) 1/12/94
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/device.h>
#include <machine/psl.h>
#include <machine/cpu.h>
#include <x68k/x68k/iodevice.h>
#include <x68k/dev/rtclock_var.h>
#ifdef GPROF
#include <sys/gmon.h>
#endif
/* We're using a 100 Hz clock. */
#define CLK_INTERVAL 200
#define CLOCKS_PER_SEC 100
/*
* 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.
*
* Resettodr restores the time of day hardware after a time change.
*
* A note on the real-time clock:
* We actually load the clock with CLK_INTERVAL-1 instead of CLK_INTERVAL.
* This is because the counter decrements to zero after N+1 enabled clock
* periods where N is the value loaded into the counter.
*/
/*
* Set up the real-time and statistics clocks. Leave stathz 0 only if
* no alternative timer is available.
*
*/
void
cpu_initclocks()
{
/* stop timer-C */
mfp.tcdcr &= 0x0f;
mfp.tcdr = CLK_INTERVAL;
/* enable interrupts for timer-C */
mfp.tcdcr |= 0x70; /* prescale 1/200 */
mfp.ierb |= 0x20;
}
/*
* 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(hz)
int hz;
{
}
/*
* Returns number of usec since last recorded clock "tick"
* (i.e. clock interrupt).
*/
int
clkread()
{
return (mfp.tcdr * CLOCKS_PER_SEC) / CLK_INTERVAL;
}
#if 0
void
DELAY(mic)
int mic;
{
u_long n;
short hpos;
/*
* busy-poll for mic microseconds. This is *no* general timeout function,
* it's meant for timing in hardware control, and as such, may not lower
* interrupt priorities to really `sleep'.
*/
/*
* this function uses HSync pulses as base units. The custom chips
* display only deals with 31.6kHz/2 refresh, this gives us a
* resolution of 1/15800 s, which is ~63us (add some fuzz so we really
* wait awhile, even if using small timeouts)
*/
n = mic/32 + 2;
do {
while ((mfp.gpip & MFP_GPIP_HSYNC) != 0)
asm("nop");
while ((mfp.gpip & MFP_GPIP_HSYNC) == 0)
asm("nop");
} while (n--);
}
#endif
#if notyet
/* implement this later. I'd suggest using both timers in CIA-A, they're
not yet used. */
#include "clock.h"
#if NCLOCK > 0
/*
* /dev/clock: mappable high resolution timer.
*
* This code implements a 32-bit recycling counter (with a 4 usec period)
* using timers 2 & 3 on the 6840 clock chip. The counter can be mapped
* RO into a user's address space to achieve low overhead (no system calls),
* high-precision timing.
*
* Note that timer 3 is also used for the high precision profiling timer
* (PROFTIMER code above). Care should be taken when both uses are
* configured as only a token effort is made to avoid conflicting use.
*/
#include <sys/proc.h>
#include <sys/resourcevar.h>
#include <sys/ioctl.h>
#include <sys/malloc.h>
#include <vm/vm.h>
#include <x68k/x68k/clockioctl.h>
#include <sys/specdev.h>
#include <sys/vnode.h>
#include <sys/mman.h>
int clockon = 0; /* non-zero if high-res timer enabled */
#ifdef PROFTIMER
int profprocs = 0; /* # of procs using profiling timer */
#endif
#ifdef DEBUG
int clockdebug = 0;
#endif
/*ARGSUSED*/
clockopen(dev, flags)
dev_t dev;
{
#ifdef PROFTIMER
#ifdef PROF
/*
* Kernel profiling enabled, give up.
*/
if (profiling)
return(EBUSY);
#endif
/*
* If any user processes are profiling, give up.
*/
if (profprocs)
return(EBUSY);
#endif
if (!clockon) {
startclock();
clockon++;
}
return(0);
}
/*ARGSUSED*/
clockclose(dev, flags)
dev_t dev;
{
(void) clockunmmap(dev, (caddr_t)0, curproc); /* XXX */
stopclock();
clockon = 0;
return(0);
}
/*ARGSUSED*/
clockioctl(dev, cmd, data, flag, p)
dev_t dev;
caddr_t data;
struct proc *p;
{
int error = 0;
switch (cmd) {
case CLOCKMAP:
error = clockmmap(dev, (caddr_t *)data, p);
break;
case CLOCKUNMAP:
error = clockunmmap(dev, *(caddr_t *)data, p);
break;
case CLOCKGETRES:
*(int *)data = CLK_RESOLUTION;
break;
default:
error = EINVAL;
break;
}
return(error);
}
/*ARGSUSED*/
clockmap(dev, off, prot)
dev_t dev;
{
return((off + (INTIOBASE+CLKBASE+CLKSR-1)) >> PGSHIFT);
}
clockmmap(dev, addrp, p)
dev_t dev;
caddr_t *addrp;
struct proc *p;
{
int error;
struct vnode vn;
struct specinfo si;
int flags;
flags = MAP_FILE|MAP_SHARED;
if (*addrp)
flags |= MAP_FIXED;
else
*addrp = (caddr_t)0x1000000; /* XXX */
vn.v_type = VCHR; /* XXX */
vn.v_specinfo = &si; /* XXX */
vn.v_rdev = dev; /* XXX */
error = vm_mmap(&p->p_vmspace->vm_map, (vm_offset_t *)addrp,
PAGE_SIZE, VM_PROT_ALL, flags, (caddr_t)&vn, 0);
return(error);
}
clockunmmap(dev, addr, p)
dev_t dev;
caddr_t addr;
struct proc *p;
{
int rv;
if (addr == 0)
return(EINVAL); /* XXX: how do we deal with this? */
rv = vm_deallocate(p->p_vmspace->vm_map, (vm_offset_t)addr, PAGE_SIZE);
return(rv == KERN_SUCCESS ? 0 : EINVAL);
}
startclock()
{
register struct clkreg *clk = (struct clkreg *)clkstd[0];
clk->clk_msb2 = -1; clk->clk_lsb2 = -1;
clk->clk_msb3 = -1; clk->clk_lsb3 = -1;
clk->clk_cr2 = CLK_CR3;
clk->clk_cr3 = CLK_OENAB|CLK_8BIT;
clk->clk_cr2 = CLK_CR1;
clk->clk_cr1 = CLK_IENAB;
}
stopclock()
{
register struct clkreg *clk = (struct clkreg *)clkstd[0];
clk->clk_cr2 = CLK_CR3;
clk->clk_cr3 = 0;
clk->clk_cr2 = CLK_CR1;
clk->clk_cr1 = CLK_IENAB;
}
#endif
#endif
#ifdef PROFTIMER
/*
* This code allows the amiga kernel to use one of the extra timers on
* the clock chip for profiling, instead of the regular system timer.
* The advantage of this is that the profiling timer can be turned up to
* a higher interrupt rate, giving finer resolution timing. The profclock
* routine is called from the lev6intr in locore, and is a specialized
* routine that calls addupc. The overhead then is far less than if
* hardclock/softclock was called. Further, the context switch code in
* locore has been changed to turn the profile clock on/off when switching
* into/out of a process that is profiling (startprofclock/stopprofclock).
* This reduces the impact of the profiling clock on other users, and might
* possibly increase the accuracy of the profiling.
*/
int profint = PRF_INTERVAL; /* Clock ticks between interrupts */
int profscale = 0; /* Scale factor from sys clock to prof clock */
char profon = 0; /* Is profiling clock on? */
/* profon values - do not change, locore.s assumes these values */
#define PRF_NONE 0x00
#define PRF_USER 0x01
#define PRF_KERNEL 0x80
initprofclock()
{
#if NCLOCK > 0
struct proc *p = curproc; /* XXX */
/*
* If the high-res timer is running, force profiling off.
* Unfortunately, this gets reflected back to the user not as
* an error but as a lack of results.
*/
if (clockon) {
p->p_stats->p_prof.pr_scale = 0;
return;
}
/*
* Keep track of the number of user processes that are profiling
* by checking the scale value.
*
* XXX: this all assumes that the profiling code is well behaved;
* i.e. profil() is called once per process with pcscale non-zero
* to turn it on, and once with pcscale zero to turn it off.
* Also assumes you don't do any forks or execs. Oh well, there
* is always adb...
*/
if (p->p_stats->p_prof.pr_scale)
profprocs++;
else
profprocs--;
#endif
/*
* The profile interrupt interval must be an even divisor
* of the CLK_INTERVAL so that scaling from a system clock
* tick to a profile clock tick is possible using integer math.
*/
if (profint > CLK_INTERVAL || (CLK_INTERVAL % profint) != 0)
profint = CLK_INTERVAL;
profscale = CLK_INTERVAL / profint;
}
startprofclock()
{
}
stopprofclock()
{
}
#ifdef PROF
/*
* profclock() is expanded in line in lev6intr() unless profiling kernel.
* Assumes it is called with clock interrupts blocked.
*/
profclock(pc, ps)
caddr_t pc;
int ps;
{
/*
* Came from user mode.
* If this process is being profiled record the tick.
*/
if (USERMODE(ps)) {
if (p->p_stats.p_prof.pr_scale)
addupc(pc, &curproc->p_stats.p_prof, 1);
}
/*
* Came from kernel (supervisor) mode.
* If we are profiling the kernel, record the tick.
*/
else if (profiling < 2) {
register int s = pc - s_lowpc;
if (s < s_textsize)
kcount[s / (HISTFRACTION * sizeof (*kcount))]++;
}
/*
* Kernel profiling was on but has been disabled.
* Mark as no longer profiling kernel and if all profiling done,
* disable the clock.
*/
if (profiling && (profon & PRF_KERNEL)) {
profon &= ~PRF_KERNEL;
if (profon == PRF_NONE)
stopprofclock();
}
}
#endif
#endif
/*
* Return the best possible estimate of the current time.
*/
void
microtime(tvp)
register struct timeval *tvp;
{
static struct timeval lasttime;
*tvp = time;
tvp->tv_usec += clkread();
while (tvp->tv_usec > 1000000) {
tvp->tv_sec++;
tvp->tv_usec -= 1000000;
}
if (tvp->tv_sec == lasttime.tv_sec &&
tvp->tv_usec <= lasttime.tv_usec &&
(tvp->tv_usec = lasttime.tv_usec + 1) > 1000000) {
tvp->tv_sec++;
tvp->tv_usec -= 1000000;
}
lasttime = *tvp;
}
/* this is a hook set by a clock driver for the configured realtime clock,
returning plain current unix-time */
long (*gettod) () = 0;
long (*settod) () = 0;
/*
* Initialize the time of day register, based on the time base which is, e.g.
* from a filesystem.
*/
void
inittodr(base)
time_t base;
{
u_long timbuf = base; /* assume no battery clock exists */
if (!gettod)
printf ("WARNING: no battery clock\n");
else
timbuf = gettod();
if (timbuf < base) {
printf ("WARNING: bad date in battery clock\n");
timbuf = base;
}
if (base < 5*SECYR) {
printf("WARNING: preposterous time in file system");
timbuf = 6*SECYR + 186*SECDAY + SECDAY/2;
printf(" -- CHECK AND RESET THE DATE!\n");
}
/* Battery clock does not store usec's, so forget about it. */
time.tv_sec = timbuf;
}
void
resettodr()
{
if (settod)
if (settod (time.tv_sec) != 1)
printf("Cannot set battery backed clock\n");
}