freebsd-dev/sys/pc98/cbus/clock.c
Alexander Motin dbd55f3ff0 - Implement MI helper functions, dividing one or two timer interrupts with
arbitrary frequencies into hardclock(), statclock() and profclock() calls.
Same code with minor variations duplicated several times over the tree for
different timer drivers and architectures.
- Switch all x86 archs to new functions, simplifying the code and removing
extra logic from timer drivers. Other archs are also welcome.
2010-05-24 11:40:49 +00:00

581 lines
14 KiB
C

/*-
* 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.
* 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: @(#)clock.c 7.2 (Berkeley) 5/12/91
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/*
* Routines to handle clock hardware.
*/
/*
* modified for PC98 by Kakefuda
*/
#include "opt_apic.h"
#include "opt_clock.h"
#include "opt_kdtrace.h"
#include "opt_isa.h"
#include "opt_mca.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/lock.h>
#include <sys/kdb.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/timetc.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/smp.h>
#include <sys/sysctl.h>
#include <machine/clock.h>
#include <machine/cpu.h>
#include <machine/frame.h>
#include <machine/intr_machdep.h>
#include <machine/md_var.h>
#include <machine/apicvar.h>
#include <machine/ppireg.h>
#include <machine/timerreg.h>
#include <machine/smp.h>
#include <pc98/pc98/pc98_machdep.h>
#ifdef DEV_ISA
#include <pc98/cbus/cbus.h>
#include <isa/isavar.h>
#endif
#ifdef KDTRACE_HOOKS
#include <sys/dtrace_bsd.h>
#endif
#define TIMER_DIV(x) ((i8254_freq + (x) / 2) / (x))
int clkintr_pending;
#ifndef TIMER_FREQ
#define TIMER_FREQ 2457600
#endif
u_int i8254_freq = TIMER_FREQ;
TUNABLE_INT("hw.i8254.freq", &i8254_freq);
int i8254_max_count;
static int i8254_real_max_count;
static int lapic_allclocks = 1;
TUNABLE_INT("machdep.lapic_allclocks", &lapic_allclocks);
static struct mtx clock_lock;
static struct intsrc *i8254_intsrc;
static u_int32_t i8254_lastcount;
static u_int32_t i8254_offset;
static int (*i8254_pending)(struct intsrc *);
static int i8254_ticked;
static enum lapic_clock using_lapic_timer = LAPIC_CLOCK_NONE;
/* Values for timerX_state: */
#define RELEASED 0
#define RELEASE_PENDING 1
#define ACQUIRED 2
#define ACQUIRE_PENDING 3
static u_char timer1_state;
static unsigned i8254_get_timecount(struct timecounter *tc);
static unsigned i8254_simple_get_timecount(struct timecounter *tc);
static void set_i8254_freq(u_int freq, int intr_freq);
static struct timecounter i8254_timecounter = {
i8254_get_timecount, /* get_timecount */
0, /* no poll_pps */
~0u, /* counter_mask */
0, /* frequency */
"i8254", /* name */
0 /* quality */
};
int
hardclockintr(struct trapframe *frame)
{
timer1clock(TRAPF_USERMODE(frame), TRAPF_PC(frame));
return (FILTER_HANDLED);
}
int
statclockintr(struct trapframe *frame)
{
return (FILTER_HANDLED);
}
static int
clkintr(struct trapframe *frame)
{
if (timecounter->tc_get_timecount == i8254_get_timecount) {
mtx_lock_spin(&clock_lock);
if (i8254_ticked)
i8254_ticked = 0;
else {
i8254_offset += i8254_max_count;
i8254_lastcount = 0;
}
clkintr_pending = 0;
mtx_unlock_spin(&clock_lock);
}
KASSERT(using_lapic_timer == LAPIC_CLOCK_NONE,
("clk interrupt enabled with lapic timer"));
#ifdef KDTRACE_HOOKS
/*
* If the DTrace hooks are configured and a callback function
* has been registered, then call it to process the high speed
* timers.
*/
int cpu = PCPU_GET(cpuid);
if (cyclic_clock_func[cpu] != NULL)
(*cyclic_clock_func[cpu])(frame);
#endif
#ifdef SMP
if (smp_started)
ipi_all_but_self(IPI_HARDCLOCK);
#endif
hardclockintr(frame);
return (FILTER_HANDLED);
}
int
timer_spkr_acquire(void)
{
int mode;
mode = TIMER_SEL1 | TIMER_SQWAVE | TIMER_16BIT;
if (timer1_state != RELEASED)
return (-1);
timer1_state = ACQUIRED;
/*
* This access to the timer registers is as atomic as possible
* because it is a single instruction. We could do better if we
* knew the rate. Use of splclock() limits glitches to 10-100us,
* and this is probably good enough for timer2, so we aren't as
* careful with it as with timer0.
*/
outb(TIMER_MODE, TIMER_SEL1 | (mode & 0x3f));
ppi_spkr_on(); /* enable counter1 output to speaker */
return (0);
}
int
timer_spkr_release(void)
{
if (timer1_state != ACQUIRED)
return (-1);
timer1_state = RELEASED;
outb(TIMER_MODE, TIMER_SEL1 | TIMER_SQWAVE | TIMER_16BIT);
ppi_spkr_off(); /* disable counter1 output to speaker */
return (0);
}
void
timer_spkr_setfreq(int freq)
{
freq = i8254_freq / freq;
mtx_lock_spin(&clock_lock);
outb(TIMER_CNTR1, (freq) & 0xff);
outb(TIMER_CNTR1, (freq) >> 8);
mtx_unlock_spin(&clock_lock);
}
static int
getit(void)
{
int high, low;
mtx_lock_spin(&clock_lock);
/* Select timer0 and latch counter value. */
outb(TIMER_MODE, TIMER_SEL0 | TIMER_LATCH);
low = inb(TIMER_CNTR0);
high = inb(TIMER_CNTR0);
mtx_unlock_spin(&clock_lock);
return ((high << 8) | low);
}
/*
* Wait "n" microseconds.
* Relies on timer 1 counting down from (i8254_freq / hz)
* Note: timer had better have been programmed before this is first used!
*/
void
DELAY(int n)
{
int delta, prev_tick, tick, ticks_left;
#ifdef DELAYDEBUG
int getit_calls = 1;
int n1;
static int state = 0;
if (state == 0) {
state = 1;
for (n1 = 1; n1 <= 10000000; n1 *= 10)
DELAY(n1);
state = 2;
}
if (state == 1)
printf("DELAY(%d)...", n);
#endif
/*
* Read the counter first, so that the rest of the setup overhead is
* counted. Guess the initial overhead is 20 usec (on most systems it
* takes about 1.5 usec for each of the i/o's in getit(). The loop
* takes about 6 usec on a 486/33 and 13 usec on a 386/20. The
* multiplications and divisions to scale the count take a while).
*
* However, if ddb is active then use a fake counter since reading
* the i8254 counter involves acquiring a lock. ddb must not do
* locking for many reasons, but it calls here for at least atkbd
* input.
*/
#ifdef KDB
if (kdb_active)
prev_tick = 1;
else
#endif
prev_tick = getit();
n -= 0; /* XXX actually guess no initial overhead */
/*
* Calculate (n * (i8254_freq / 1e6)) without using floating point
* and without any avoidable overflows.
*/
if (n <= 0)
ticks_left = 0;
else if (n < 256)
/*
* Use fixed point to avoid a slow division by 1000000.
* 39099 = 1193182 * 2^15 / 10^6 rounded to nearest.
* 2^15 is the first power of 2 that gives exact results
* for n between 0 and 256.
*/
ticks_left = ((u_int)n * 39099 + (1 << 15) - 1) >> 15;
else
/*
* Don't bother using fixed point, although gcc-2.7.2
* generates particularly poor code for the long long
* division, since even the slow way will complete long
* before the delay is up (unless we're interrupted).
*/
ticks_left = ((u_int)n * (long long)i8254_freq + 999999)
/ 1000000;
while (ticks_left > 0) {
#ifdef KDB
if (kdb_active) {
outb(0x5f, 0);
tick = prev_tick - 1;
if (tick <= 0)
tick = i8254_max_count;
} else
#endif
tick = getit();
#ifdef DELAYDEBUG
++getit_calls;
#endif
delta = prev_tick - tick;
prev_tick = tick;
if (delta < 0) {
delta += i8254_max_count;
/*
* Guard against i8254_max_count being wrong.
* This shouldn't happen in normal operation,
* but it may happen if set_i8254_freq() is
* traced.
*/
if (delta < 0)
delta = 0;
}
ticks_left -= delta;
}
#ifdef DELAYDEBUG
if (state == 1)
printf(" %d calls to getit() at %d usec each\n",
getit_calls, (n + 5) / getit_calls);
#endif
}
static void
set_i8254_freq(u_int freq, int intr_freq)
{
int new_i8254_real_max_count;
i8254_timecounter.tc_frequency = freq;
mtx_lock_spin(&clock_lock);
i8254_freq = freq;
if (using_lapic_timer != LAPIC_CLOCK_NONE)
new_i8254_real_max_count = 0x10000;
else
new_i8254_real_max_count = TIMER_DIV(intr_freq);
if (new_i8254_real_max_count != i8254_real_max_count) {
i8254_real_max_count = new_i8254_real_max_count;
if (i8254_real_max_count == 0x10000)
i8254_max_count = 0xffff;
else
i8254_max_count = i8254_real_max_count;
outb(TIMER_MODE, TIMER_SEL0 | TIMER_RATEGEN | TIMER_16BIT);
outb(TIMER_CNTR0, i8254_real_max_count & 0xff);
outb(TIMER_CNTR0, i8254_real_max_count >> 8);
}
mtx_unlock_spin(&clock_lock);
}
static void
i8254_restore(void)
{
mtx_lock_spin(&clock_lock);
outb(TIMER_MODE, TIMER_SEL0 | TIMER_RATEGEN | TIMER_16BIT);
outb(TIMER_CNTR0, i8254_real_max_count & 0xff);
outb(TIMER_CNTR0, i8254_real_max_count >> 8);
mtx_unlock_spin(&clock_lock);
}
/*
* Restore all the timers non-atomically (XXX: should be atomically).
*
* This function is called from pmtimer_resume() to restore all the timers.
* This should not be necessary, but there are broken laptops that do not
* restore all the timers on resume.
*/
void
timer_restore(void)
{
i8254_restore(); /* restore i8254_freq and hz */
}
/* This is separate from startrtclock() so that it can be called early. */
void
i8254_init(void)
{
mtx_init(&clock_lock, "clk", NULL, MTX_SPIN | MTX_NOPROFILE);
if (pc98_machine_type & M_8M)
i8254_freq = 1996800L; /* 1.9968 MHz */
else
i8254_freq = 2457600L; /* 2.4576 MHz */
set_i8254_freq(i8254_freq, hz);
}
void
startrtclock()
{
set_i8254_freq(i8254_freq, hz);
tc_init(&i8254_timecounter);
init_TSC();
}
/*
* Start both clocks running.
*/
void
cpu_initclocks()
{
#if defined(DEV_APIC)
enum lapic_clock tlsca;
tlsca = lapic_allclocks == 0 ? LAPIC_CLOCK_HARDCLOCK : LAPIC_CLOCK_ALL;
using_lapic_timer = lapic_setup_clock(tlsca);
#endif
/*
* If we aren't using the local APIC timer to drive the kernel
* clocks, setup the interrupt handler for the 8254 timer 0 so
* that it can drive hardclock(). Otherwise, change the 8254
* timecounter to user a simpler algorithm.
*/
if (using_lapic_timer == LAPIC_CLOCK_NONE) {
timer1hz = hz;
intr_add_handler("clk", 0, (driver_filter_t *)clkintr, NULL,
NULL, INTR_TYPE_CLK, NULL);
i8254_intsrc = intr_lookup_source(0);
if (i8254_intsrc != NULL)
i8254_pending =
i8254_intsrc->is_pic->pic_source_pending;
} else {
i8254_timecounter.tc_get_timecount =
i8254_simple_get_timecount;
i8254_timecounter.tc_counter_mask = 0xffff;
set_i8254_freq(i8254_freq, hz);
}
if (using_lapic_timer != LAPIC_CLOCK_ALL) {
profhz = hz;
if (hz < 128)
stathz = hz;
else
stathz = hz / (hz / 128);
}
timer2hz = 0;
init_TSC_tc();
}
void
cpu_startprofclock(void)
{
}
void
cpu_stopprofclock(void)
{
}
static int
sysctl_machdep_i8254_freq(SYSCTL_HANDLER_ARGS)
{
int error;
u_int freq;
/*
* Use `i8254' instead of `timer' in external names because `timer'
* is is too generic. Should use it everywhere.
*/
freq = i8254_freq;
error = sysctl_handle_int(oidp, &freq, 0, req);
if (error == 0 && req->newptr != NULL)
set_i8254_freq(freq, hz);
return (error);
}
SYSCTL_PROC(_machdep, OID_AUTO, i8254_freq, CTLTYPE_INT | CTLFLAG_RW,
0, sizeof(u_int), sysctl_machdep_i8254_freq, "IU", "");
static unsigned
i8254_simple_get_timecount(struct timecounter *tc)
{
return (i8254_max_count - getit());
}
static unsigned
i8254_get_timecount(struct timecounter *tc)
{
u_int count;
u_int high, low;
u_int eflags;
eflags = read_eflags();
mtx_lock_spin(&clock_lock);
/* Select timer0 and latch counter value. */
outb(TIMER_MODE, TIMER_SEL0 | TIMER_LATCH);
low = inb(TIMER_CNTR0);
high = inb(TIMER_CNTR0);
count = i8254_max_count - ((high << 8) | low);
if (count < i8254_lastcount ||
(!i8254_ticked && (clkintr_pending ||
((count < 20 || (!(eflags & PSL_I) &&
count < i8254_max_count / 2u)) &&
i8254_pending != NULL && i8254_pending(i8254_intsrc))))) {
i8254_ticked = 1;
i8254_offset += i8254_max_count;
}
i8254_lastcount = count;
count += i8254_offset;
mtx_unlock_spin(&clock_lock);
return (count);
}
#ifdef DEV_ISA
/*
* Attach to the ISA PnP descriptors for the timer
*/
static struct isa_pnp_id attimer_ids[] = {
{ 0x0001d041 /* PNP0100 */, "AT timer" },
{ 0 }
};
static int
attimer_probe(device_t dev)
{
int result;
result = ISA_PNP_PROBE(device_get_parent(dev), dev, attimer_ids);
if (result <= 0)
device_quiet(dev);
return(result);
}
static int
attimer_attach(device_t dev)
{
return(0);
}
static device_method_t attimer_methods[] = {
/* Device interface */
DEVMETHOD(device_probe, attimer_probe),
DEVMETHOD(device_attach, attimer_attach),
DEVMETHOD(device_detach, bus_generic_detach),
DEVMETHOD(device_shutdown, bus_generic_shutdown),
DEVMETHOD(device_suspend, bus_generic_suspend),
DEVMETHOD(device_resume, bus_generic_resume),
{ 0, 0 }
};
static driver_t attimer_driver = {
"attimer",
attimer_methods,
1, /* no softc */
};
static devclass_t attimer_devclass;
DRIVER_MODULE(attimer, isa, attimer_driver, attimer_devclass, 0, 0);
#endif /* DEV_ISA */