freebsd-dev/sys/x86/isa/clock.c
John Baldwin fdce57a042 Add an EARLY_AP_STARTUP option to start APs earlier during boot.
Currently, Application Processors (non-boot CPUs) are started by
MD code at SI_SUB_CPU, but they are kept waiting in a "pen" until
SI_SUB_SMP at which point they are released to run kernel threads.
SI_SUB_SMP is one of the last SYSINIT levels, so APs don't enter
the scheduler and start running threads until fairly late in the
boot.

This change moves SI_SUB_SMP up to just before software interrupt
threads are created allowing the APs to start executing kernel
threads much sooner (before any devices are probed).  This allows
several initialization routines that need to perform initialization
on all CPUs to now perform that initialization in one step rather
than having to defer the AP initialization to a second SYSINIT run
at SI_SUB_SMP.  It also permits all CPUs to be available for
handling interrupts before any devices are probed.

This last feature fixes a problem on with interrupt vector exhaustion.
Specifically, in the old model all device interrupts were routed
onto the boot CPU during boot.  Later after the APs were released at
SI_SUB_SMP, interrupts were redistributed across all CPUs.

However, several drivers for multiqueue hardware allocate N interrupts
per CPU in the system.  In a system with many CPUs, just a few drivers
doing this could exhaust the available pool of interrupt vectors on
the boot CPU as each driver was allocating N * mp_ncpu vectors on the
boot CPU.  Now, drivers will allocate interrupts on their desired CPUs
during boot meaning that only N interrupts are allocated from the boot
CPU instead of N * mp_ncpu.

Some other bits of code can also be simplified as smp_started is
now true much earlier and will now always be true for these bits of
code.  This removes the need to treat the single-CPU boot environment
as a special case.

As a transition aid, the new behavior is available under a new kernel
option (EARLY_AP_STARTUP).  This will allow the option to be turned off
if need be during initial testing.  I plan to enable this on x86 by
default in a followup commit in the next few days and to have all
platforms moved over before 11.0.  Once the transition is complete,
the option will be removed along with the !EARLY_AP_STARTUP code.

These changes have only been tested on x86.  Other platform maintainers
are encouraged to port their architectures over as well.  The main
things to check for are any uses of smp_started in MD code that can be
simplified and SI_SUB_SMP SYSINITs in MD code that can be removed in
the EARLY_AP_STARTUP case (e.g. the interrupt shuffling).

PR:		kern/199321
Reviewed by:	markj, gnn, kib
Sponsored by:	Netflix
2016-05-14 18:22:52 +00:00

775 lines
19 KiB
C

/*-
* 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.
* 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.
*/
#include "opt_clock.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/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>
#ifdef PC98
#include <pc98/pc98/pc98_machdep.h>
#else
#include <isa/rtc.h>
#endif
#ifdef DEV_ISA
#ifdef PC98
#include <pc98/cbus/cbus.h>
#else
#include <isa/isareg.h>
#endif
#include <isa/isavar.h>
#endif
#ifdef DEV_MCA
#include <i386/bios/mca_machdep.h>
#endif
int clkintr_pending;
#ifndef TIMER_FREQ
#ifdef PC98
#define TIMER_FREQ 2457600
#else
#define TIMER_FREQ 1193182
#endif
#endif
u_int i8254_freq = TIMER_FREQ;
TUNABLE_INT("hw.i8254.freq", &i8254_freq);
int i8254_max_count;
static int i8254_timecounter = 1;
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;
#ifdef PC98
int port_rid2;
struct resource *port_res2;
#endif
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);
#ifdef DEV_MCA
/* Reset clock interrupt by asserting bit 7 of port 0x61 */
if (MCA_system)
outb(0x61, inb(0x61) | 0x80);
#endif
return (FILTER_HANDLED);
}
int
timer_spkr_acquire(void)
{
int mode;
#ifdef PC98
mode = TIMER_SEL1 | TIMER_SQWAVE | TIMER_16BIT;
#else
mode = TIMER_SEL2 | TIMER_SQWAVE | TIMER_16BIT;
#endif
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.
*/
#ifdef PC98
outb(TIMER_MODE, TIMER_SEL1 | (mode & 0x3f));
#else
outb(TIMER_MODE, TIMER_SEL2 | (mode & 0x3f));
#endif
ppi_spkr_on(); /* enable counter2 output to speaker */
return (0);
}
int
timer_spkr_release(void)
{
if (timer2_state != ACQUIRED)
return (-1);
timer2_state = RELEASED;
#ifdef PC98
outb(TIMER_MODE, TIMER_SEL1 | TIMER_SQWAVE | TIMER_16BIT);
#else
outb(TIMER_MODE, TIMER_SEL2 | TIMER_SQWAVE | TIMER_16BIT);
#endif
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);
#ifdef PC98
outb(TIMER_CNTR1, freq & 0xff);
outb(TIMER_CNTR1, freq >> 8);
#else
outb(TIMER_CNTR2, freq & 0xff);
outb(TIMER_CNTR2, freq >> 8);
#endif
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) {
#ifdef PC98
outb(0x5f, 0);
#else
inb(0x84);
#endif
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 */
#ifndef PC98
atrtc_restore(); /* reenable RTC interrupts */
#endif
}
#endif
/* This is separate from startrtclock() so that it can be called early. */
void
i8254_init(void)
{
#ifdef PC98
if (pc98_machine_type & M_8M)
i8254_freq = 1996800L; /* 1.9968 MHz */
#endif
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 }
};
#ifdef PC98
static void
pc98_alloc_resource(device_t dev)
{
static bus_addr_t iat1[] = {0, 2, 4, 6};
static bus_addr_t iat2[] = {0, 4};
struct attimer_softc *sc;
sc = device_get_softc(dev);
sc->port_rid = 0;
bus_set_resource(dev, SYS_RES_IOPORT, sc->port_rid, IO_TIMER1, 1);
sc->port_res = isa_alloc_resourcev(dev, SYS_RES_IOPORT,
&sc->port_rid, iat1, 4, RF_ACTIVE);
if (sc->port_res == NULL)
device_printf(dev, "Warning: Couldn't map I/O.\n");
else
isa_load_resourcev(sc->port_res, iat1, 4);
sc->port_rid2 = 4;
bus_set_resource(dev, SYS_RES_IOPORT, sc->port_rid2, TIMER_CNTR1, 1);
sc->port_res2 = isa_alloc_resourcev(dev, SYS_RES_IOPORT,
&sc->port_rid2, iat2, 2, RF_ACTIVE);
if (sc->port_res2 == NULL)
device_printf(dev, "Warning: Couldn't map I/O.\n");
else
isa_load_resourcev(sc->port_res2, iat2, 2);
}
static void
pc98_release_resource(device_t dev)
{
struct attimer_softc *sc;
sc = device_get_softc(dev);
if (sc->port_res)
bus_release_resource(dev, SYS_RES_IOPORT, sc->port_rid,
sc->port_res);
if (sc->port_res2)
bus_release_resource(dev, SYS_RES_IOPORT, sc->port_rid2,
sc->port_res2);
}
#endif
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");
#ifdef PC98
/* To print resources correctly. */
pc98_alloc_resource(dev);
pc98_release_resource(dev);
#endif
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));
#ifdef PC98
pc98_alloc_resource(dev);
#else
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");
#endif
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);
#endif /* DEV_ISA */