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freebsd/sys/dev/acpica/acpi_timer.c
Nate Lawson be2b179704 Style and whitespace changes. Also, make the ivar functions non-inline
since inlining failed due to the size of BUS_*
2003-08-28 16:06:30 +00:00

390 lines
10 KiB
C

/*-
* Copyright (c) 2000, 2001 Michael Smith
* Copyright (c) 2000 BSDi
* All rights reserved.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*
* $FreeBSD$
*/
#include "opt_acpi.h"
#include <sys/param.h>
#include <sys/bus.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#if __FreeBSD_version >= 500000
#include <sys/timetc.h>
#else
#include <sys/time.h>
#endif
#include <machine/bus.h>
#include <machine/resource.h>
#include <sys/rman.h>
#include "acpi.h"
#include <dev/acpica/acpivar.h>
#include <dev/pci/pcivar.h>
/*
* A timecounter based on the free-running ACPI timer.
*
* Based on the i386-only mp_clock.c by <phk@FreeBSD.ORG>.
*/
/* Hooks for the ACPI CA debugging infrastructure */
#define _COMPONENT ACPI_SYSTEM
ACPI_MODULE_NAME("TIMER")
static device_t acpi_timer_dev;
struct resource *acpi_timer_reg;
static u_int acpi_timer_frequency = 14318182 / 4;
static void acpi_timer_identify(driver_t *driver, device_t parent);
static int acpi_timer_probe(device_t dev);
static int acpi_timer_attach(device_t dev);
static unsigned acpi_timer_get_timecount(struct timecounter *tc);
static unsigned acpi_timer_get_timecount_safe(struct timecounter *tc);
static int acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS);
static void acpi_timer_test(void);
static uint32_t read_counter(void);
static int test_counter(void);
static device_method_t acpi_timer_methods[] = {
DEVMETHOD(device_identify, acpi_timer_identify),
DEVMETHOD(device_probe, acpi_timer_probe),
DEVMETHOD(device_attach, acpi_timer_attach),
{0, 0}
};
static driver_t acpi_timer_driver = {
"acpi_timer",
acpi_timer_methods,
0,
};
static devclass_t acpi_timer_devclass;
DRIVER_MODULE(acpi_timer, acpi, acpi_timer_driver, acpi_timer_devclass, 0, 0);
static struct timecounter acpi_timer_timecounter = {
acpi_timer_get_timecount_safe,
0,
0xffffff,
0,
"ACPI",
1000
};
static uint32_t
read_counter()
{
bus_space_handle_t bsh;
bus_space_tag_t bst;
u_int32_t tv;
bsh = rman_get_bushandle(acpi_timer_reg);
bst = rman_get_bustag(acpi_timer_reg);
tv = bus_space_read_4(bst, bsh, 0);
bus_space_barrier(bst, bsh, 0, 4, BUS_SPACE_BARRIER_READ);
return (tv);
}
#define N 2000
static int
test_counter()
{
u_int last, this;
int min, max, n, delta;
min = 10000000;
max = 0;
last = read_counter();
for (n = 0; n < N; n++) {
this = read_counter();
delta = (this - last) & 0xffffff;
if (delta > max)
max = delta;
else if (delta < min)
min = delta;
last = this;
}
if (max - min > 2)
n = 0;
else if (min < 0 || max == 0)
n = 0;
else
n = 1;
if (bootverbose) {
printf("ACPI timer looks %s min = %d, max = %d, width = %d\n",
n ? "GOOD" : "BAD ",
min, max, max - min);
}
return (n);
}
#undef N
/*
* Locate the ACPI timer using the FADT, set up and allocate the I/O resources
* we will be using.
*/
static void
acpi_timer_identify(driver_t *driver, device_t parent)
{
device_t dev;
char desc[40];
u_long rlen, rstart;
int i, j, rid, rtype;
ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
if (acpi_disabled("timer") || AcpiGbl_FADT == NULL)
return_VOID;
if ((dev = BUS_ADD_CHILD(parent, 0, "acpi_timer", 0)) == NULL) {
device_printf(parent, "could not add acpi_timer0\n");
return_VOID;
}
acpi_timer_dev = dev;
rid = 0;
rlen = AcpiGbl_FADT->PmTmLen;
rtype = (AcpiGbl_FADT->XPmTmrBlk.AddressSpaceId)
? SYS_RES_IOPORT : SYS_RES_MEMORY;
rstart = AcpiGbl_FADT->XPmTmrBlk.Address;
bus_set_resource(dev, rtype, rid, rstart, rlen);
acpi_timer_reg = bus_alloc_resource(dev, rtype, &rid, 0, ~0, 1, RF_ACTIVE);
if (acpi_timer_reg == NULL) {
device_printf(dev, "couldn't allocate I/O resource (%s 0x%lx)\n",
rtype == SYS_RES_IOPORT ? "port" : "mem", rstart);
return_VOID;
}
if (testenv("debug.acpi.timer_test"))
acpi_timer_test();
acpi_timer_timecounter.tc_frequency = acpi_timer_frequency;
j = 0;
for(i = 0; i < 10; i++)
j += test_counter();
if (j == 10) {
acpi_timer_timecounter.tc_name = "ACPI-fast";
acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount;
} else {
acpi_timer_timecounter.tc_name = "ACPI-safe";
acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount_safe;
}
tc_init(&acpi_timer_timecounter);
sprintf(desc, "%d-bit timer at 3.579545MHz",
AcpiGbl_FADT->TmrValExt ? 32 : 24);
device_set_desc_copy(dev, desc);
return_VOID;
}
static int
acpi_timer_probe(device_t dev)
{
if (dev == acpi_timer_dev)
return (0);
return (ENXIO);
}
static int
acpi_timer_attach(device_t dev)
{
return (0);
}
/*
* Fetch current time value from reliable hardware.
*/
static unsigned
acpi_timer_get_timecount(struct timecounter *tc)
{
return (read_counter());
}
/*
* Fetch current time value from hardware that may not correctly
* latch the counter.
*/
static unsigned
acpi_timer_get_timecount_safe(struct timecounter *tc)
{
unsigned u1, u2, u3;
u2 = read_counter();
u3 = read_counter();
do {
u1 = u2;
u2 = u3;
u3 = read_counter();
} while (u1 > u2 || u2 > u3 || u3 - u1 > 15);
return (u2);
}
/*
* Timecounter freqency adjustment interface.
*/
static int
acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS)
{
int error;
u_int freq;
if (acpi_timer_timecounter.tc_frequency == 0)
return (EOPNOTSUPP);
freq = acpi_timer_frequency;
error = sysctl_handle_int(oidp, &freq, sizeof(freq), req);
if (error == 0 && req->newptr != NULL) {
acpi_timer_frequency = freq;
acpi_timer_timecounter.tc_frequency = acpi_timer_frequency;
}
return (error);
}
SYSCTL_PROC(_machdep, OID_AUTO, acpi_timer_freq, CTLTYPE_INT | CTLFLAG_RW,
0, sizeof(u_int), acpi_timer_sysctl_freq, "I", "");
/*
* Test harness for verifying ACPI timer behaviour.
* Boot with debug.acpi.timer_test set to invoke this.
*/
static void
acpi_timer_test(void)
{
u_int32_t u1, u2, u3;
u1 = read_counter();
u2 = read_counter();
u3 = read_counter();
device_printf(acpi_timer_dev, "timer test in progress, reboot to quit.\n");
for (;;) {
/*
* The failure case is where u3 > u1, but u2 does not fall between
* the two, ie. it contains garbage.
*/
if (u3 > u1) {
if (u2 < u1 || u2 > u3)
device_printf(acpi_timer_dev,
"timer is not monotonic: 0x%08x,0x%08x,0x%08x\n",
u1, u2, u3);
}
u1 = u2;
u2 = u3;
u3 = read_counter();
}
}
/*
* Chipset workaround driver hung off PCI.
*
* Some ACPI timers are known or believed to suffer from implementation
* problems which can lead to erroneous values being read from the timer.
*
* Since we can't trust unknown chipsets, we default to a timer-read
* routine which compensates for the most common problem (as detailed
* in the excerpt from the Intel PIIX4 datasheet below).
*
* When we detect a known-functional chipset, we disable the workaround
* to improve speed.
*
* ] 20. ACPI Timer Errata
* ]
* ] Problem: The power management timer may return improper result when
* ] read. Although the timer value settles properly after incrementing,
* ] while incrementing there is a 3nS window every 69.8nS where the
* ] timer value is indeterminate (a 4.2% chance that the data will be
* ] incorrect when read). As a result, the ACPI free running count up
* ] timer specification is violated due to erroneous reads. Implication:
* ] System hangs due to the "inaccuracy" of the timer when used by
* ] software for time critical events and delays.
* ]
* ] Workaround: Read the register twice and compare.
* ] Status: This will not be fixed in the PIIX4 or PIIX4E, it is fixed
* ] in the PIIX4M.
*
* The counter is in other words not latched to the PCI bus clock when
* read. Notice the workaround isn't: We need to read until we have
* three monotonic samples and then use the middle one, otherwise we are
* not protected against the fact that the bits can be wrong in two
* directions. If we only cared about monosity two reads would be enough.
*/
#if 0
static int acpi_timer_pci_probe(device_t dev);
static device_method_t acpi_timer_pci_methods[] = {
DEVMETHOD(device_probe, acpi_timer_pci_probe),
{0, 0}
};
static driver_t acpi_timer_pci_driver = {
"acpi_timer_pci",
acpi_timer_pci_methods,
0,
};
devclass_t acpi_timer_pci_devclass;
DRIVER_MODULE(acpi_timer_pci, pci, acpi_timer_pci_driver,
acpi_timer_pci_devclass, 0, 0);
/*
* Look at PCI devices going past; if we detect one we know contains
* a functional ACPI timer device, enable the faster timecounter read
* routine.
*/
static int
acpi_timer_pci_probe(device_t dev)
{
int vendor, device, revid;
vendor = pci_get_vendor(dev);
device = pci_get_device(dev);
revid = pci_get_revid(dev);
/* Detect the PIIX4M and i440MX, respectively */
if ((vendor == 0x8086 && device == 0x7113 && revid >= 0x03) ||
(vendor == 0x8086 && device == 0x719b)) {
acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount;
acpi_timer_timecounter.tc_name = "ACPI-fast";
if (bootverbose) {
device_printf(acpi_timer_dev,"functional ACPI timer detected, "
"enabling fast timecount interface\n");
}
}
/* We never match anything */
return (ENXIO);
}
#endif