freebsd-dev/sys/x86/isa/clock.c
Ian Lepore 8355852f85 Use separate mutexes for atrtc and i8254 locking. Change all the strange
un-function-like RTC_LOCK/UNLOCK macro usage into normal function calls.
Since there is no longer any need to handle register access from a debugger
context, those function calls can just be regular mutex lock/unlock calls.

Requested by:  bde
2018-03-11 18:20:49 +00:00

673 lines
16 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1990 The Regents of the University of California.
* Copyright (c) 2010 Alexander Motin <mav@FreeBSD.org>
* 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. 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.
*/
#include "opt_clock.h"
#include "opt_isa.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/kernel.h>
#include <sys/module.h>
#include <sys/rman.h>
#include <sys/sched.h>
#include <sys/smp.h>
#include <sys/sysctl.h>
#include <sys/timeet.h>
#include <sys/timetc.h>
#include <machine/clock.h>
#include <machine/cpu.h>
#include <machine/intr_machdep.h>
#include <machine/ppireg.h>
#include <machine/timerreg.h>
#include <x86/init.h>
#include <isa/rtc.h>
#ifdef DEV_ISA
#include <isa/isareg.h>
#include <isa/isavar.h>
#endif
int clkintr_pending;
#ifndef TIMER_FREQ
#define TIMER_FREQ 1193182
#endif
u_int i8254_freq = TIMER_FREQ;
TUNABLE_INT("hw.i8254.freq", &i8254_freq);
int i8254_max_count;
static int i8254_timecounter = 1;
static struct mtx clock_lock;
static struct intsrc *i8254_intsrc;
static uint16_t i8254_lastcount;
static uint16_t i8254_offset;
static int (*i8254_pending)(struct intsrc *);
static int i8254_ticked;
struct attimer_softc {
int intr_en;
int port_rid, intr_rid;
struct resource *port_res;
struct resource *intr_res;
void *intr_handler;
struct timecounter tc;
struct eventtimer et;
int mode;
#define MODE_STOP 0
#define MODE_PERIODIC 1
#define MODE_ONESHOT 2
uint32_t period;
};
static struct attimer_softc *attimer_sc = NULL;
static int timer0_period = -2;
static int timer0_mode = 0xffff;
static int timer0_last = 0xffff;
/* Values for timerX_state: */
#define RELEASED 0
#define RELEASE_PENDING 1
#define ACQUIRED 2
#define ACQUIRE_PENDING 3
static u_char timer2_state;
static unsigned i8254_get_timecount(struct timecounter *tc);
static void set_i8254_freq(int mode, uint32_t period);
void
clock_init(void)
{
/* Init the clock lock */
mtx_init(&clock_lock, "clk", NULL, MTX_SPIN | MTX_NOPROFILE);
/* Init the clock in order to use DELAY */
init_ops.early_clock_source_init();
}
static int
clkintr(void *arg)
{
struct attimer_softc *sc = (struct attimer_softc *)arg;
if (i8254_timecounter && sc->period != 0) {
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);
}
if (sc->et.et_active && sc->mode != MODE_STOP)
sc->et.et_event_cb(&sc->et, sc->et.et_arg);
return (FILTER_HANDLED);
}
int
timer_spkr_acquire(void)
{
int mode;
mode = TIMER_SEL2 | TIMER_SQWAVE | TIMER_16BIT;
if (timer2_state != RELEASED)
return (-1);
timer2_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_SEL2 | (mode & 0x3f));
ppi_spkr_on(); /* enable counter2 output to speaker */
return (0);
}
int
timer_spkr_release(void)
{
if (timer2_state != ACQUIRED)
return (-1);
timer2_state = RELEASED;
outb(TIMER_MODE, TIMER_SEL2 | TIMER_SQWAVE | TIMER_16BIT);
ppi_spkr_off(); /* disable counter2 output to speaker */
return (0);
}
void
timer_spkr_setfreq(int freq)
{
freq = i8254_freq / freq;
mtx_lock_spin(&clock_lock);
outb(TIMER_CNTR2, freq & 0xff);
outb(TIMER_CNTR2, 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
i8254_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) {
inb(0x84);
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(int mode, uint32_t period)
{
int new_count, new_mode;
mtx_lock_spin(&clock_lock);
if (mode == MODE_STOP) {
if (i8254_timecounter) {
mode = MODE_PERIODIC;
new_count = 0x10000;
} else
new_count = -1;
} else {
new_count = min(((uint64_t)i8254_freq * period +
0x80000000LLU) >> 32, 0x10000);
}
if (new_count == timer0_period)
goto out;
i8254_max_count = ((new_count & ~0xffff) != 0) ? 0xffff : new_count;
timer0_period = (mode == MODE_PERIODIC) ? new_count : -1;
switch (mode) {
case MODE_STOP:
new_mode = TIMER_SEL0 | TIMER_INTTC | TIMER_16BIT;
outb(TIMER_MODE, new_mode);
outb(TIMER_CNTR0, 0);
outb(TIMER_CNTR0, 0);
break;
case MODE_PERIODIC:
new_mode = TIMER_SEL0 | TIMER_RATEGEN | TIMER_16BIT;
outb(TIMER_MODE, new_mode);
outb(TIMER_CNTR0, new_count & 0xff);
outb(TIMER_CNTR0, new_count >> 8);
break;
case MODE_ONESHOT:
if (new_count < 256 && timer0_last < 256) {
new_mode = TIMER_SEL0 | TIMER_INTTC | TIMER_LSB;
if (new_mode != timer0_mode)
outb(TIMER_MODE, new_mode);
outb(TIMER_CNTR0, new_count & 0xff);
break;
}
new_mode = TIMER_SEL0 | TIMER_INTTC | TIMER_16BIT;
if (new_mode != timer0_mode)
outb(TIMER_MODE, new_mode);
outb(TIMER_CNTR0, new_count & 0xff);
outb(TIMER_CNTR0, new_count >> 8);
break;
default:
panic("set_i8254_freq: unknown operational mode");
}
timer0_mode = new_mode;
timer0_last = new_count;
out:
mtx_unlock_spin(&clock_lock);
}
static void
i8254_restore(void)
{
timer0_period = -2;
timer0_mode = 0xffff;
timer0_last = 0xffff;
if (attimer_sc != NULL)
set_i8254_freq(attimer_sc->mode, attimer_sc->period);
else
set_i8254_freq(MODE_STOP, 0);
}
#ifndef __amd64__
/*
* 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. The APM spec was at best vague on the
* subject.
* pmtimer is used only with the old APM power management, and not with
* acpi, which is required for amd64, so skip it in that case.
*/
void
timer_restore(void)
{
i8254_restore(); /* restore i8254_freq and hz */
atrtc_restore(); /* reenable RTC interrupts */
}
#endif
/* This is separate from startrtclock() so that it can be called early. */
void
i8254_init(void)
{
set_i8254_freq(MODE_STOP, 0);
}
void
startrtclock()
{
init_TSC();
}
void
cpu_initclocks(void)
{
#ifdef EARLY_AP_STARTUP
struct thread *td;
int i;
td = curthread;
cpu_initclocks_bsp();
CPU_FOREACH(i) {
if (i == 0)
continue;
thread_lock(td);
sched_bind(td, i);
thread_unlock(td);
cpu_initclocks_ap();
}
thread_lock(td);
if (sched_is_bound(td))
sched_unbind(td);
thread_unlock(td);
#else
cpu_initclocks_bsp();
#endif
}
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 too generic. Should use it everywhere.
*/
freq = i8254_freq;
error = sysctl_handle_int(oidp, &freq, 0, req);
if (error == 0 && req->newptr != NULL) {
i8254_freq = freq;
if (attimer_sc != NULL) {
set_i8254_freq(attimer_sc->mode, attimer_sc->period);
attimer_sc->tc.tc_frequency = freq;
} else {
set_i8254_freq(MODE_STOP, 0);
}
}
return (error);
}
SYSCTL_PROC(_machdep, OID_AUTO, i8254_freq, CTLTYPE_INT | CTLFLAG_RW,
0, sizeof(u_int), sysctl_machdep_i8254_freq, "IU",
"i8254 timer frequency");
static unsigned
i8254_get_timecount(struct timecounter *tc)
{
device_t dev = (device_t)tc->tc_priv;
struct attimer_softc *sc = device_get_softc(dev);
register_t flags;
uint16_t count;
u_int high, low;
if (sc->period == 0)
return (i8254_max_count - getit());
#ifdef __amd64__
flags = read_rflags();
#else
flags = read_eflags();
#endif
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 || (!(flags & 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);
}
static int
attimer_start(struct eventtimer *et, sbintime_t first, sbintime_t period)
{
device_t dev = (device_t)et->et_priv;
struct attimer_softc *sc = device_get_softc(dev);
if (period != 0) {
sc->mode = MODE_PERIODIC;
sc->period = period;
} else {
sc->mode = MODE_ONESHOT;
sc->period = first;
}
if (!sc->intr_en) {
i8254_intsrc->is_pic->pic_enable_source(i8254_intsrc);
sc->intr_en = 1;
}
set_i8254_freq(sc->mode, sc->period);
return (0);
}
static int
attimer_stop(struct eventtimer *et)
{
device_t dev = (device_t)et->et_priv;
struct attimer_softc *sc = device_get_softc(dev);
sc->mode = MODE_STOP;
sc->period = 0;
set_i8254_freq(sc->mode, sc->period);
return (0);
}
#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);
/* ENOENT means no PnP-ID, device is hinted. */
if (result == ENOENT) {
device_set_desc(dev, "AT timer");
return (BUS_PROBE_LOW_PRIORITY);
}
return (result);
}
static int
attimer_attach(device_t dev)
{
struct attimer_softc *sc;
rman_res_t s;
int i;
attimer_sc = sc = device_get_softc(dev);
bzero(sc, sizeof(struct attimer_softc));
if (!(sc->port_res = bus_alloc_resource(dev, SYS_RES_IOPORT,
&sc->port_rid, IO_TIMER1, IO_TIMER1 + 3, 4, RF_ACTIVE)))
device_printf(dev,"Warning: Couldn't map I/O.\n");
i8254_intsrc = intr_lookup_source(0);
if (i8254_intsrc != NULL)
i8254_pending = i8254_intsrc->is_pic->pic_source_pending;
resource_int_value(device_get_name(dev), device_get_unit(dev),
"timecounter", &i8254_timecounter);
set_i8254_freq(MODE_STOP, 0);
if (i8254_timecounter) {
sc->tc.tc_get_timecount = i8254_get_timecount;
sc->tc.tc_counter_mask = 0xffff;
sc->tc.tc_frequency = i8254_freq;
sc->tc.tc_name = "i8254";
sc->tc.tc_quality = 0;
sc->tc.tc_priv = dev;
tc_init(&sc->tc);
}
if (resource_int_value(device_get_name(dev), device_get_unit(dev),
"clock", &i) != 0 || i != 0) {
sc->intr_rid = 0;
while (bus_get_resource(dev, SYS_RES_IRQ, sc->intr_rid,
&s, NULL) == 0 && s != 0)
sc->intr_rid++;
if (!(sc->intr_res = bus_alloc_resource(dev, SYS_RES_IRQ,
&sc->intr_rid, 0, 0, 1, RF_ACTIVE))) {
device_printf(dev,"Can't map interrupt.\n");
return (0);
}
/* Dirty hack, to make bus_setup_intr to not enable source. */
i8254_intsrc->is_handlers++;
if ((bus_setup_intr(dev, sc->intr_res,
INTR_MPSAFE | INTR_TYPE_CLK,
(driver_filter_t *)clkintr, NULL,
sc, &sc->intr_handler))) {
device_printf(dev, "Can't setup interrupt.\n");
i8254_intsrc->is_handlers--;
return (0);
}
i8254_intsrc->is_handlers--;
i8254_intsrc->is_pic->pic_enable_intr(i8254_intsrc);
sc->et.et_name = "i8254";
sc->et.et_flags = ET_FLAGS_PERIODIC;
if (!i8254_timecounter)
sc->et.et_flags |= ET_FLAGS_ONESHOT;
sc->et.et_quality = 100;
sc->et.et_frequency = i8254_freq;
sc->et.et_min_period = (0x0002LLU << 32) / i8254_freq;
sc->et.et_max_period = (0xfffeLLU << 32) / i8254_freq;
sc->et.et_start = attimer_start;
sc->et.et_stop = attimer_stop;
sc->et.et_priv = dev;
et_register(&sc->et);
}
return(0);
}
static int
attimer_resume(device_t dev)
{
i8254_restore();
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, attimer_resume),
{ 0, 0 }
};
static driver_t attimer_driver = {
"attimer",
attimer_methods,
sizeof(struct attimer_softc),
};
static devclass_t attimer_devclass;
DRIVER_MODULE(attimer, isa, attimer_driver, attimer_devclass, 0, 0);
DRIVER_MODULE(attimer, acpi, attimer_driver, attimer_devclass, 0, 0);
ISA_PNP_INFO(attimer_ids);
#endif /* DEV_ISA */