/*-
* 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.
*/
#include <sys/cdefs.h>
#include "opt_acpi.h"
#include <sys/param.h>
#include <sys/bus.h>
#include <sys/eventhandler.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/sysctl.h>
#include <sys/timetc.h>
#include <machine/bus.h>
#include <machine/resource.h>
#include <sys/rman.h>
#include <contrib/dev/acpica/include/acpi.h>
#include <contrib/dev/acpica/include/accommon.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_TIMER
ACPI_MODULE_NAME("TIMER")
static device_t acpi_timer_dev;
static struct resource *acpi_timer_reg;
static bus_space_handle_t acpi_timer_bsh;
static bus_space_tag_t acpi_timer_bst;
static eventhandler_tag acpi_timer_eh;
static u_int acpi_timer_frequency = 14318182 / 4;
/* Knob to disable acpi_timer device */
bool acpi_timer_disabled = false;
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 void acpi_timer_resume_handler(struct timecounter *);
static void acpi_timer_suspend_handler(struct timecounter *);
static u_int acpi_timer_get_timecount(struct timecounter *tc);
static u_int acpi_timer_get_timecount_safe(struct timecounter *tc);
static int acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS);
static void acpi_timer_boot_test(void);
static int acpi_timer_test(void);
static int acpi_timer_test_enabled = 0;
TUNABLE_INT("hw.acpi.timer_test_enabled", &acpi_timer_test_enabled);
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),
DEVMETHOD_END
};
static driver_t acpi_timer_driver = {
"acpi_timer",
acpi_timer_methods,
0,
};
DRIVER_MODULE(acpi_timer, acpi, acpi_timer_driver, 0, 0);
MODULE_DEPEND(acpi_timer, acpi, 1, 1, 1);
static struct timecounter acpi_timer_timecounter = {
acpi_timer_get_timecount_safe, /* get_timecount function */
0, /* no poll_pps */
0, /* no default counter_mask */
0, /* no default frequency */
"ACPI", /* name */
-1 /* quality (chosen later) */
};
static __inline uint32_t
acpi_timer_read(void)
{
return (bus_space_read_4(acpi_timer_bst, acpi_timer_bsh, 0));
}
/*
* 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;
rman_res_t rlen, rstart;
int rid, rtype;
ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
if (acpi_disabled("timer") || (acpi_quirks & ACPI_Q_TIMER) ||
acpi_timer_dev || acpi_timer_disabled ||
AcpiGbl_FADT.PmTimerLength == 0)
return_VOID;
if ((dev = BUS_ADD_CHILD(parent, 2, "acpi_timer", 0)) == NULL) {
device_printf(parent, "could not add acpi_timer0\n");
return_VOID;
}
acpi_timer_dev = dev;
switch (AcpiGbl_FADT.XPmTimerBlock.SpaceId) {
case ACPI_ADR_SPACE_SYSTEM_MEMORY:
rtype = SYS_RES_MEMORY;
break;
case ACPI_ADR_SPACE_SYSTEM_IO:
rtype = SYS_RES_IOPORT;
break;
default:
return_VOID;
}
rid = 0;
rlen = AcpiGbl_FADT.PmTimerLength;
rstart = AcpiGbl_FADT.XPmTimerBlock.Address;
if (bus_set_resource(dev, rtype, rid, rstart, rlen))
device_printf(dev, "couldn't set resource (%s 0x%jx+0x%jx)\n",
(rtype == SYS_RES_IOPORT) ? "port" : "mem", rstart, rlen);
return_VOID;
}
static int
acpi_timer_probe(device_t dev)
{
char desc[40];
int i, j, rid, rtype;
ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
if (dev != acpi_timer_dev)
return (ENXIO);
switch (AcpiGbl_FADT.XPmTimerBlock.SpaceId) {
case ACPI_ADR_SPACE_SYSTEM_MEMORY:
rtype = SYS_RES_MEMORY;
break;
case ACPI_ADR_SPACE_SYSTEM_IO:
rtype = SYS_RES_IOPORT;
break;
default:
return (ENXIO);
}
rid = 0;
acpi_timer_reg = bus_alloc_resource_any(dev, rtype, &rid, RF_ACTIVE);
if (acpi_timer_reg == NULL) {
device_printf(dev, "couldn't allocate resource (%s 0x%lx)\n",
(rtype == SYS_RES_IOPORT) ? "port" : "mem",
(u_long)AcpiGbl_FADT.XPmTimerBlock.Address);
return (ENXIO);
}
acpi_timer_bsh = rman_get_bushandle(acpi_timer_reg);
acpi_timer_bst = rman_get_bustag(acpi_timer_reg);
if (AcpiGbl_FADT.Flags & ACPI_FADT_32BIT_TIMER)
acpi_timer_timecounter.tc_counter_mask = 0xffffffff;
else
acpi_timer_timecounter.tc_counter_mask = 0x00ffffff;
acpi_timer_timecounter.tc_frequency = acpi_timer_frequency;
acpi_timer_timecounter.tc_flags = TC_FLAGS_SUSPEND_SAFE;
if (testenv("debug.acpi.timer_test"))
acpi_timer_boot_test();
/*
* If all tests of the counter succeed, use the ACPI-fast method. If
* at least one failed, default to using the safe routine, which reads
* the timer multiple times to get a consistent value before returning.
*/
j = 0;
if (bootverbose)
printf("ACPI timer:");
for (i = 0; i < 10; i++)
j += acpi_timer_test();
if (bootverbose)
printf(" -> %d\n", j);
if (j == 10) {
acpi_timer_timecounter.tc_name = "ACPI-fast";
acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount;
acpi_timer_timecounter.tc_quality = 900;
} else {
acpi_timer_timecounter.tc_name = "ACPI-safe";
acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount_safe;
acpi_timer_timecounter.tc_quality = 850;
}
tc_init(&acpi_timer_timecounter);
sprintf(desc, "%d-bit timer at %u.%06uMHz",
(AcpiGbl_FADT.Flags & ACPI_FADT_32BIT_TIMER) != 0 ? 32 : 24,
acpi_timer_frequency / 1000000, acpi_timer_frequency % 1000000);
device_set_desc_copy(dev, desc);
/* Release the resource, we'll allocate it again during attach. */
bus_release_resource(dev, rtype, rid, acpi_timer_reg);
return (0);
}
static int
acpi_timer_attach(device_t dev)
{
int rid, rtype;
ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
switch (AcpiGbl_FADT.XPmTimerBlock.SpaceId) {
case ACPI_ADR_SPACE_SYSTEM_MEMORY:
rtype = SYS_RES_MEMORY;
break;
case ACPI_ADR_SPACE_SYSTEM_IO:
rtype = SYS_RES_IOPORT;
break;
default:
return (ENXIO);
}
rid = 0;
acpi_timer_reg = bus_alloc_resource_any(dev, rtype, &rid, RF_ACTIVE);
if (acpi_timer_reg == NULL)
return (ENXIO);
acpi_timer_bsh = rman_get_bushandle(acpi_timer_reg);
acpi_timer_bst = rman_get_bustag(acpi_timer_reg);
/* Register suspend event handler. */
if (EVENTHANDLER_REGISTER(power_suspend, acpi_timer_suspend_handler,
&acpi_timer_timecounter, EVENTHANDLER_PRI_LAST) == NULL)
device_printf(dev, "failed to register suspend event handler\n");
return (0);
}
static void
acpi_timer_resume_handler(struct timecounter *newtc)
{
struct timecounter *tc;
tc = timecounter;
if (tc != newtc) {
if (bootverbose)
device_printf(acpi_timer_dev,
"restoring timecounter, %s -> %s\n",
tc->tc_name, newtc->tc_name);
(void)newtc->tc_get_timecount(newtc);
timecounter = newtc;
}
}
static void
acpi_timer_suspend_handler(struct timecounter *newtc)
{
struct timecounter *tc;
/* Deregister existing resume event handler. */
if (acpi_timer_eh != NULL) {
EVENTHANDLER_DEREGISTER(power_resume, acpi_timer_eh);
acpi_timer_eh = NULL;
}
if ((timecounter->tc_flags & TC_FLAGS_SUSPEND_SAFE) != 0) {
/*
* If we are using a suspend safe timecounter, don't
* save/restore it across suspend/resume.
*/
return;
}
KASSERT(newtc == &acpi_timer_timecounter,
("acpi_timer_suspend_handler: wrong timecounter"));
tc = timecounter;
if (tc != newtc) {
if (bootverbose)
device_printf(acpi_timer_dev,
"switching timecounter, %s -> %s\n",
tc->tc_name, newtc->tc_name);
(void)acpi_timer_read();
(void)acpi_timer_read();
timecounter = newtc;
acpi_timer_eh = EVENTHANDLER_REGISTER(power_resume,
acpi_timer_resume_handler, tc, EVENTHANDLER_PRI_LAST);
}
}
/*
* Fetch current time value from reliable hardware.
*/
static u_int
acpi_timer_get_timecount(struct timecounter *tc)
{
return (acpi_timer_read());
}
/*
* Fetch current time value from hardware that may not correctly
* latch the counter. 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.
*/
static u_int
acpi_timer_get_timecount_safe(struct timecounter *tc)
{
u_int u1, u2, u3;
u2 = acpi_timer_read();
u3 = acpi_timer_read();
do {
u1 = u2;
u2 = u3;
u3 = acpi_timer_read();
} while (u1 > u2 || u2 > u3);
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, 0, 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 | CTLFLAG_MPSAFE, 0, 0,
acpi_timer_sysctl_freq, "I",
"ACPI timer frequency");
/*
* Some ACPI timers are known or believed to suffer from implementation
* problems which can lead to erroneous values being read. This function
* tests for consistent results from the timer and returns 1 if it believes
* the timer is consistent, otherwise it returns 0.
*
* It appears the cause is that the counter is not latched to the PCI bus
* clock when read:
*
* ] 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.
*/
#define N 2000
static int
acpi_timer_test(void)
{
uint32_t last, this;
int delta, max, max2, min, n;
register_t s;
/* Skip the test based on the hw.acpi.timer_test_enabled tunable. */
if (!acpi_timer_test_enabled)
return (1);
TSENTER();
min = INT32_MAX;
max = max2 = 0;
/* Test the timer with interrupts disabled to get accurate results. */
s = intr_disable();
last = acpi_timer_read();
for (n = 0; n < N; n++) {
this = acpi_timer_read();
delta = acpi_TimerDelta(this, last);
if (delta > max) {
max2 = max;
max = delta;
} else if (delta > max2)
max2 = delta;
if (delta < min)
min = delta;
last = this;
}
intr_restore(s);
delta = max2 - min;
if ((max - min > 8 || delta > 3) && vm_guest == VM_GUEST_NO)
n = 0;
else if (min < 0 || max == 0 || max2 == 0)
n = 0;
else
n = 1;
if (bootverbose)
printf(" %d/%d", n, delta);
TSEXIT();
return (n);
}
#undef N
/*
* Test harness for verifying ACPI timer behaviour.
* Boot with debug.acpi.timer_test set to invoke this.
*/
static void
acpi_timer_boot_test(void)
{
uint32_t u1, u2, u3;
u1 = acpi_timer_read();
u2 = acpi_timer_read();
u3 = acpi_timer_read();
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 = acpi_timer_read();
}
}
