[dragonfly.git] / sys / dev / acpica5 / acpi_timer.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: src/sys/dev/acpica/acpi_timer.c,v 1.35 2004/07/22 05:42:14 njl Exp $
 * $DragonFly: src/sys/dev/acpica5/acpi_timer.c,v 1.13 2007/10/09 09:46:56 y0netan1 Exp $
 */
#include "opt_acpi.h"
#include <sys/param.h>
#include <sys/bus.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/sysctl.h>
#include <sys/systimer.h>
#include <sys/rman.h>

#include <machine/lock.h>
#include <bus/pci/pcivar.h>

#include "acpi.h"
#include "acpivar.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 sysclock_t		acpi_counter_mask;
static sysclock_t		acpi_last_counter;

#define ACPI_TIMER_FREQ		(14318182 / 4)

static sysclock_t acpi_timer_get_timecount(void);
static sysclock_t acpi_timer_get_timecount24(void);
static sysclock_t acpi_timer_get_timecount_safe(void);
static void acpi_timer_construct(struct cputimer *timer, sysclock_t oldclock);

static struct cputimer acpi_cputimer = {
	SLIST_ENTRY_INITIALIZER,
	"ACPI",
	CPUTIMER_PRI_ACPI,
	CPUTIMER_ACPI,
	acpi_timer_get_timecount_safe,
	cputimer_default_fromhz,
	cputimer_default_fromus,
	acpi_timer_construct,
	cputimer_default_destruct,
	ACPI_TIMER_FREQ,
	0, 0, 0
};

static int	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 int	acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS);

static u_int	acpi_timer_read(void);
static int	acpi_timer_test(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);
MODULE_DEPEND(acpi_timer, acpi, 1, 1, 1);

static u_int
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 int
acpi_timer_identify(driver_t *driver, device_t parent)
{
    device_t dev;
    u_long rlen, rstart;
    int rid, rtype;

    /*
     * Just try once, do nothing if the 'acpi' bus is rescanned.
     */
    if (device_get_state(parent) == DS_ATTACHED)
	return (0);

    ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);

    if (acpi_disabled("timer") || acpi_timer_dev)
	return (ENXIO);

    if ((dev = BUS_ADD_CHILD(parent, parent, 0, "acpi_timer", 0)) == NULL) {
	device_printf(parent, "could not add acpi_timer0\n");
	return (ENXIO);
    }
    acpi_timer_dev = dev;

    rid = 0;
    rtype = AcpiGbl_FADT.XPmTimerBlock.SpaceId ?
	SYS_RES_IOPORT : SYS_RES_MEMORY;
    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%lx+0x%lx)\n",
	    (rtype == SYS_RES_IOPORT) ? "port" : "mem", rstart, rlen);
	return (ENXIO);
    }
    return (0);
}

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);

    rid = 0;
    rtype = AcpiGbl_FADT.XPmTimerBlock.SpaceId ?
	SYS_RES_IOPORT : SYS_RES_MEMORY;
    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) != 0)
	acpi_counter_mask = 0xffffffff;
    else
	acpi_counter_mask = 0x00ffffff;

    /*
     * 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;
    for (i = 0; i < 10; i++)
	j += acpi_timer_test();
    if (j == 10) {
	if (acpi_counter_mask == 0xffffffff) {
	    acpi_cputimer.name = "ACPI-fast";
	    acpi_cputimer.count = acpi_timer_get_timecount;
	} else {
	    acpi_cputimer.name = "ACPI-fast24";
	    acpi_cputimer.count = acpi_timer_get_timecount24;
	}
    } else {
	if (acpi_counter_mask == 0xffffffff)
		acpi_cputimer.name = "ACPI-safe";
	else
		acpi_cputimer.name = "ACPI-safe24";
	acpi_cputimer.count = acpi_timer_get_timecount_safe;
    }

    ksprintf(desc, "%d-bit timer at 3.579545MHz",
	    (AcpiGbl_FADT.Flags & ACPI_FADT_32BIT_TIMER) ? 32 : 24);
    device_set_desc_copy(dev, desc);

    cputimer_register(&acpi_cputimer);
    cputimer_select(&acpi_cputimer, 0);
    /* 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__);

    rid = 0;
    rtype = AcpiGbl_FADT.XPmTimerBlock.SpaceId ?
	SYS_RES_IOPORT : SYS_RES_MEMORY;
    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);
    return (0);
}

/*
 * Construct the timer.  Adjust the base so the system clock does not
 * jump weirdly.
 */
static void
acpi_timer_construct(struct cputimer *timer, sysclock_t oldclock)
{
    timer->base = 0;
    timer->base = oldclock - acpi_timer_get_timecount_safe();
}

/*
 * Fetch current time value from reliable hardware.
 *
 * The cputimer interface requires a 32 bit return value.  If the ACPI timer
 * is only 24 bits then we have to keep track of the upper 8 bits on our
 * own.
 *
 * XXX we could probably get away with using a per-cpu field for this and
 * just use interrupt disablement instead of clock_lock.
 */
static sysclock_t
acpi_timer_get_timecount24(void)
{
    sysclock_t counter;

    clock_lock();
    counter = acpi_timer_read();
    if (counter < acpi_last_counter)
	acpi_cputimer.base += 0x01000000;
    acpi_last_counter = counter;
    counter += acpi_cputimer.base;
    clock_unlock();
    return (counter);
}

static sysclock_t
acpi_timer_get_timecount(void)
{
    return (acpi_timer_read() + acpi_cputimer.base);
}

/*
 * 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 sysclock_t
acpi_timer_get_timecount_safe(void)
{
    u_int u1, u2, u3;

    if (acpi_counter_mask != 0xffffffff)
	clock_lock();

    u2 = acpi_timer_read();
    u3 = acpi_timer_read();
    do {
	u1 = u2;
	u2 = u3;
	u3 = acpi_timer_read();
    } while (u1 > u2 || u2 > u3);

    if (acpi_counter_mask != 0xffffffff) {
	if (u2 < acpi_last_counter)
	    acpi_cputimer.base += 0x01000000;
	acpi_last_counter = u2;
	clock_unlock();
    }
    return (u2 + acpi_cputimer.base);
}

/*
 * Timecounter freqency adjustment interface.
 */ 
static int
acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS)
{
    int error;
    u_int freq;
 
    if (acpi_cputimer.freq == 0)
	return (EOPNOTSUPP);
    freq = acpi_cputimer.freq;
    error = sysctl_handle_int(oidp, &freq, sizeof(freq), req);
    if (error == 0 && req->newptr != NULL)
	cputimer_set_frequency(&acpi_cputimer, freq);

    return (error);
}
 
SYSCTL_PROC(_machdep, OID_AUTO, acpi_timer_freq, CTLTYPE_INT | CTLFLAG_RW,
	    0, sizeof(u_int), acpi_timer_sysctl_freq, "I", "");

/*
 * 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.
 */

static int
acpi_timer_test(void)
{
    uint32_t	last, this;
    int		min, max, n, delta;
    register_t	s;

    min = 10000000;
    max = 0;

    /* Test the timer with interrupts disabled to get accurate results. */
#if defined(__i386__)
    s = read_eflags();
#elif defined(__amd64__)
    s = read_rflags();
#else
#error "no read_eflags"
#endif
    cpu_disable_intr();
    last = acpi_timer_read();
    for (n = 0; n < 2000; n++) {
	this = acpi_timer_read();
	delta = acpi_TimerDelta(this, last);
	if (delta > max)
	    max = delta;
	else if (delta < min)
	    min = delta;
	last = this;
    }
#if defined(__i386__)
    write_eflags(s);
#elif defined(__amd64__)
    write_rflags(s);
#else
#error "no read_eflags"
#endif

    if (max - min > 2)
	n = 0;
    else if (min < 0 || max == 0)
	n = 0;
    else
	n = 1;
    if (bootverbose) {
	kprintf("ACPI timer looks %s min = %d, max = %d, width = %d\n",
		n ? "GOOD" : "BAD ",
		min, max, max - min);
    }

    return (n);
}
Commit	Line	Data
5ed44076 MD	1	/*-
	2	* Copyright (c) 2000, 2001 Michael Smith
	3	* Copyright (c) 2000 BSDi
	4	* All rights reserved.
	5	*
	6	* Redistribution and use in source and binary forms, with or without
	7	* modification, are permitted provided that the following conditions
	8	* are met:
	9	* 1. Redistributions of source code must retain the above copyright
	10	* notice, this list of conditions and the following disclaimer.
	11	* 2. Redistributions in binary form must reproduce the above copyright
	12	* notice, this list of conditions and the following disclaimer in the
	13	* documentation and/or other materials provided with the distribution.
	14	*
	15	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
	16	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	17	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	18	* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
	19	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	20	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	21	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	22	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	23	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	24	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	25	* SUCH DAMAGE.
	26	*
3e5760cd YT	27	* $FreeBSD: src/sys/dev/acpica/acpi_timer.c,v 1.35 2004/07/22 05:42:14 njl Exp $
3e5760cd YT	28	* $DragonFly: src/sys/dev/acpica5/acpi_timer.c,v 1.13 2007/10/09 09:46:56 y0netan1 Exp $
5ed44076 MD	29	*/
	30	#include "opt_acpi.h"
	31	#include <sys/param.h>
	32	#include <sys/bus.h>
	33	#include <sys/kernel.h>
49e48b8a	34	#include <sys/module.h>
5ed44076	35	#include <sys/sysctl.h>
7817ea35	36	#include <sys/systimer.h>
1f7ab7c9	37	#include <sys/rman.h>
5ed44076	38
7817ea35	39	#include <machine/lock.h>
5ed44076 MD	40	#include <bus/pci/pcivar.h>
	41
	42	#include "acpi.h"
	43	#include "acpivar.h"
	44
5ed44076 MD	45	/*
	46	* A timecounter based on the free-running ACPI timer.
	47	*
	48	* Based on the i386-only mp_clock.c by <phk@FreeBSD.ORG>.
	49	*/
	50
	51	/* Hooks for the ACPI CA debugging infrastructure */
f9d8cd12	52	#define _COMPONENT ACPI_TIMER
5ed44076 MD	53	ACPI_MODULE_NAME("TIMER")
5ed44076 MD	54
f9d8cd12 MD	55	static device_t acpi_timer_dev;
	56	static struct resource *acpi_timer_reg;
	57	static bus_space_handle_t acpi_timer_bsh;
	58	static bus_space_tag_t acpi_timer_bst;
7817ea35 MD	59	static sysclock_t acpi_counter_mask;
	60	static sysclock_t acpi_last_counter;
	61
	62	#define ACPI_TIMER_FREQ (14318182 / 4)
	63
	64	static sysclock_t acpi_timer_get_timecount(void);
	65	static sysclock_t acpi_timer_get_timecount24(void);
	66	static sysclock_t acpi_timer_get_timecount_safe(void);
	67	static void acpi_timer_construct(struct cputimer *timer, sysclock_t oldclock);
	68
	69	static struct cputimer acpi_cputimer = {
d8fdd978	70	SLIST_ENTRY_INITIALIZER,
7817ea35 MD	71	"ACPI",
	72	CPUTIMER_PRI_ACPI,
	73	CPUTIMER_ACPI,
	74	acpi_timer_get_timecount_safe,
	75	cputimer_default_fromhz,
	76	cputimer_default_fromus,
	77	acpi_timer_construct,
	78	cputimer_default_destruct,
	79	ACPI_TIMER_FREQ,
	80	0, 0, 0
	81	};
5ed44076	82
39b5d600	83	static int acpi_timer_identify(driver_t *driver, device_t parent);
5ed44076 MD	84	static int acpi_timer_probe(device_t dev);
5ed44076 MD	85	static int acpi_timer_attach(device_t dev);
5ed44076	86	static int acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS);
5ed44076	87
f9d8cd12 MD	88	static u_int acpi_timer_read(void);
f9d8cd12 MD	89	static int acpi_timer_test(void);
5ed44076 MD	90
	91	static device_method_t acpi_timer_methods[] = {
	92	DEVMETHOD(device_identify, acpi_timer_identify),
	93	DEVMETHOD(device_probe, acpi_timer_probe),
	94	DEVMETHOD(device_attach, acpi_timer_attach),
	95
	96	{0, 0}
	97	};
	98
	99	static driver_t acpi_timer_driver = {
	100	"acpi_timer",
	101	acpi_timer_methods,
	102	0,
	103	};
	104
	105	static devclass_t acpi_timer_devclass;
	106	DRIVER_MODULE(acpi_timer, acpi, acpi_timer_driver, acpi_timer_devclass, 0, 0);
f9d8cd12	107	MODULE_DEPEND(acpi_timer, acpi, 1, 1, 1);
5ed44076	108
f9d8cd12	109	static u_int
c436375a	110	acpi_timer_read(void)
5ed44076	111	{
f9d8cd12	112	return (bus_space_read_4(acpi_timer_bst, acpi_timer_bsh, 0));
5ed44076 MD	113	}
5ed44076 MD	114
5ed44076 MD	115	/*
	116	* Locate the ACPI timer using the FADT, set up and allocate the I/O resources
	117	* we will be using.
	118	*/
39b5d600	119	static int
5ed44076 MD	120	acpi_timer_identify(driver_t *driver, device_t parent)
5ed44076 MD	121	{
3e5760cd YT	122	device_t dev;
	123	u_long rlen, rstart;
	124	int rid, rtype;
5ed44076	125
39b5d600 MD	126	/*
	127	* Just try once, do nothing if the 'acpi' bus is rescanned.
	128	*/
	129	if (device_get_state(parent) == DS_ATTACHED)
	130	return (0);
	131
5ed44076 MD	132	ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
5ed44076 MD	133
3e5760cd	134	if (acpi_disabled("timer") \|\| acpi_timer_dev)
39b5d600	135	return (ENXIO);
f9d8cd12	136
2581072f	137	if ((dev = BUS_ADD_CHILD(parent, parent, 0, "acpi_timer", 0)) == NULL) {
5ed44076	138	device_printf(parent, "could not add acpi_timer0\n");
39b5d600	139	return (ENXIO);
5ed44076 MD	140	}
	141	acpi_timer_dev = dev;
	142
	143	rid = 0;
3e5760cd YT	144	rtype = AcpiGbl_FADT.XPmTimerBlock.SpaceId ?
3e5760cd YT	145	SYS_RES_IOPORT : SYS_RES_MEMORY;
e1eeedd0	146	rlen = AcpiGbl_FADT.PmTimerLength;
e1eeedd0	147	rstart = AcpiGbl_FADT.XPmTimerBlock.Address;
3e5760cd YT	148	if (bus_set_resource(dev, rtype, rid, rstart, rlen)) {
	149	device_printf(dev, "couldn't set resource (%s 0x%lx+0x%lx)\n",
	150	(rtype == SYS_RES_IOPORT) ? "port" : "mem", rstart, rlen);
	151	return (ENXIO);
	152	}
	153	return (0);
	154	}
	155
	156	static int
	157	acpi_timer_probe(device_t dev)
	158	{
	159	char desc[40];
	160	int i, j, rid, rtype;
	161
	162	ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
	163
	164	if (dev != acpi_timer_dev)
	165	return (ENXIO);
	166
	167	rid = 0;
	168	rtype = AcpiGbl_FADT.XPmTimerBlock.SpaceId ?
	169	SYS_RES_IOPORT : SYS_RES_MEMORY;
f9d8cd12	170	acpi_timer_reg = bus_alloc_resource_any(dev, rtype, &rid, RF_ACTIVE);
5ed44076	171	if (acpi_timer_reg == NULL) {
3e5760cd YT	172	device_printf(dev, "couldn't allocate resource (%s 0x%lx)\n",
	173	(rtype == SYS_RES_IOPORT) ? "port" : "mem",
	174	(u_long)AcpiGbl_FADT.XPmTimerBlock.Address);
39b5d600	175	return (ENXIO);
5ed44076	176	}
f9d8cd12 MD	177	acpi_timer_bsh = rman_get_bushandle(acpi_timer_reg);
f9d8cd12 MD	178	acpi_timer_bst = rman_get_bustag(acpi_timer_reg);
e1eeedd0	179	if ((AcpiGbl_FADT.Flags & ACPI_FADT_32BIT_TIMER) != 0)
7817ea35	180	acpi_counter_mask = 0xffffffff;
f9d8cd12	181	else
7817ea35	182	acpi_counter_mask = 0x00ffffff;
5ed44076	183
f9d8cd12 MD	184	/*
	185	* If all tests of the counter succeed, use the ACPI-fast method. If
	186	* at least one failed, default to using the safe routine, which reads
	187	* the timer multiple times to get a consistent value before returning.
	188	*/
5ed44076	189	j = 0;
f9d8cd12 MD	190	for (i = 0; i < 10; i++)
f9d8cd12 MD	191	j += acpi_timer_test();
5ed44076	192	if (j == 10) {
7817ea35 MD	193	if (acpi_counter_mask == 0xffffffff) {
	194	acpi_cputimer.name = "ACPI-fast";
	195	acpi_cputimer.count = acpi_timer_get_timecount;
	196	} else {
	197	acpi_cputimer.name = "ACPI-fast24";
	198	acpi_cputimer.count = acpi_timer_get_timecount24;
	199	}
5ed44076	200	} else {
50e6791e SZ	201	if (acpi_counter_mask == 0xffffffff)
	202	acpi_cputimer.name = "ACPI-safe";
	203	else
	204	acpi_cputimer.name = "ACPI-safe24";
7817ea35	205	acpi_cputimer.count = acpi_timer_get_timecount_safe;
5ed44076	206	}
5ed44076	207
f8c7a42d	208	ksprintf(desc, "%d-bit timer at 3.579545MHz",
e1eeedd0	209	(AcpiGbl_FADT.Flags & ACPI_FADT_32BIT_TIMER) ? 32 : 24);
5ed44076 MD	210	device_set_desc_copy(dev, desc);
5ed44076 MD	211
7817ea35 MD	212	cputimer_register(&acpi_cputimer);
7817ea35 MD	213	cputimer_select(&acpi_cputimer, 0);
3e5760cd YT	214	/* Release the resource, we'll allocate it again during attach. */
3e5760cd YT	215	bus_release_resource(dev, rtype, rid, acpi_timer_reg);
39b5d600	216	return (0);
5ed44076 MD	217	}
	218
	219	static int
3e5760cd	220	acpi_timer_attach(device_t dev)
5ed44076	221	{
3e5760cd	222	int rid, rtype;
5ed44076	223
3e5760cd	224	ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
5ed44076	225
3e5760cd YT	226	rid = 0;
	227	rtype = AcpiGbl_FADT.XPmTimerBlock.SpaceId ?
	228	SYS_RES_IOPORT : SYS_RES_MEMORY;
	229	acpi_timer_reg = bus_alloc_resource_any(dev, rtype, &rid, RF_ACTIVE);
	230	if (acpi_timer_reg == NULL)
	231	return (ENXIO);
	232	acpi_timer_bsh = rman_get_bushandle(acpi_timer_reg);
	233	acpi_timer_bst = rman_get_bustag(acpi_timer_reg);
5ed44076 MD	234	return (0);
	235	}
	236
	237	/*
7817ea35 MD	238	* Construct the timer. Adjust the base so the system clock does not
	239	* jump weirdly.
	240	*/
	241	static void
	242	acpi_timer_construct(struct cputimer *timer, sysclock_t oldclock)
	243	{
	244	timer->base = 0;
	245	timer->base = oldclock - acpi_timer_get_timecount_safe();
	246	}
	247
	248	/*
5ed44076	249	* Fetch current time value from reliable hardware.
7817ea35 MD	250	*
	251	* The cputimer interface requires a 32 bit return value. If the ACPI timer
	252	* is only 24 bits then we have to keep track of the upper 8 bits on our
	253	* own.
	254	*
	255	* XXX we could probably get away with using a per-cpu field for this and
	256	* just use interrupt disablement instead of clock_lock.
5ed44076	257	*/
7817ea35 MD	258	static sysclock_t
7817ea35 MD	259	acpi_timer_get_timecount24(void)
5ed44076	260	{
7817ea35 MD	261	sysclock_t counter;
	262
	263	clock_lock();
	264	counter = acpi_timer_read();
	265	if (counter < acpi_last_counter)
	266	acpi_cputimer.base += 0x01000000;
	267	acpi_last_counter = counter;
	268	counter += acpi_cputimer.base;
	269	clock_unlock();
	270	return (counter);
	271	}
	272
	273	static sysclock_t
	274	acpi_timer_get_timecount(void)
	275	{
	276	return (acpi_timer_read() + acpi_cputimer.base);
5ed44076 MD	277	}
	278
	279	/*
	280	* Fetch current time value from hardware that may not correctly
f9d8cd12 MD	281	* latch the counter. We need to read until we have three monotonic
	282	* samples and then use the middle one, otherwise we are not protected
	283	* against the fact that the bits can be wrong in two directions. If
	284	* we only cared about monosity, two reads would be enough.
5ed44076	285	*/
7817ea35 MD	286	static sysclock_t
7817ea35 MD	287	acpi_timer_get_timecount_safe(void)
5ed44076	288	{
f9d8cd12	289	u_int u1, u2, u3;
5ed44076	290
7817ea35 MD	291	if (acpi_counter_mask != 0xffffffff)
	292	clock_lock();
	293
f9d8cd12 MD	294	u2 = acpi_timer_read();
f9d8cd12 MD	295	u3 = acpi_timer_read();
5ed44076 MD	296	do {
	297	u1 = u2;
	298	u2 = u3;
f9d8cd12 MD	299	u3 = acpi_timer_read();
f9d8cd12 MD	300	} while (u1 > u2 \|\| u2 > u3);
5ed44076	301
7817ea35 MD	302	if (acpi_counter_mask != 0xffffffff) {
	303	if (u2 < acpi_last_counter)
	304	acpi_cputimer.base += 0x01000000;
	305	acpi_last_counter = u2;
	306	clock_unlock();
	307	}
	308	return (u2 + acpi_cputimer.base);
5ed44076 MD	309	}
	310
	311	/*
	312	* Timecounter freqency adjustment interface.
	313	*/
	314	static int
	315	acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS)
	316	{
	317	int error;
	318	u_int freq;
	319
7817ea35	320	if (acpi_cputimer.freq == 0)
5ed44076	321	return (EOPNOTSUPP);
7817ea35	322	freq = acpi_cputimer.freq;
5ed44076	323	error = sysctl_handle_int(oidp, &freq, sizeof(freq), req);
7817ea35 MD	324	if (error == 0 && req->newptr != NULL)
7817ea35 MD	325	cputimer_set_frequency(&acpi_cputimer, freq);
5ed44076 MD	326
	327	return (error);
	328	}
	329
	330	SYSCTL_PROC(_machdep, OID_AUTO, acpi_timer_freq, CTLTYPE_INT \| CTLFLAG_RW,
	331	0, sizeof(u_int), acpi_timer_sysctl_freq, "I", "");
	332
	333	/*
5ed44076	334	* Some ACPI timers are known or believed to suffer from implementation
f9d8cd12 MD	335	* problems which can lead to erroneous values being read. This function
	336	* tests for consistent results from the timer and returns 1 if it believes
	337	* the timer is consistent, otherwise it returns 0.
5ed44076	338	*
f9d8cd12 MD	339	* It appears the cause is that the counter is not latched to the PCI bus
f9d8cd12 MD	340	* clock when read:
5ed44076 MD	341	*
	342	* ] 20. ACPI Timer Errata
	343	* ]
	344	* ] Problem: The power management timer may return improper result when
	345	* ] read. Although the timer value settles properly after incrementing,
	346	* ] while incrementing there is a 3nS window every 69.8nS where the
	347	* ] timer value is indeterminate (a 4.2% chance that the data will be
	348	* ] incorrect when read). As a result, the ACPI free running count up
	349	* ] timer specification is violated due to erroneous reads. Implication:
	350	* ] System hangs due to the "inaccuracy" of the timer when used by
	351	* ] software for time critical events and delays.
	352	* ]
	353	* ] Workaround: Read the register twice and compare.
	354	* ] Status: This will not be fixed in the PIIX4 or PIIX4E, it is fixed
	355	* ] in the PIIX4M.
5ed44076	356	*/
7817ea35	357
f9d8cd12	358	static int
c436375a	359	acpi_timer_test(void)
f9d8cd12 MD	360	{
	361	uint32_t last, this;
	362	int min, max, n, delta;
	363	register_t s;
5ed44076	364
f9d8cd12 MD	365	min = 10000000;
f9d8cd12 MD	366	max = 0;
5ed44076	367
f9d8cd12	368	/* Test the timer with interrupts disabled to get accurate results. */
e774ca6d	369	#if defined(__i386__)
7817ea35	370	s = read_eflags();
e774ca6d MD	371	#elif defined(__amd64__)
	372	s = read_rflags();
	373	#else
	374	#error "no read_eflags"
	375	#endif
7817ea35	376	cpu_disable_intr();
f9d8cd12	377	last = acpi_timer_read();
7817ea35	378	for (n = 0; n < 2000; n++) {
f9d8cd12 MD	379	this = acpi_timer_read();
	380	delta = acpi_TimerDelta(this, last);
	381	if (delta > max)
	382	max = delta;
	383	else if (delta < min)
	384	min = delta;
	385	last = this;
	386	}
e774ca6d	387	#if defined(__i386__)
7817ea35	388	write_eflags(s);
e774ca6d MD	389	#elif defined(__amd64__)
	390	write_rflags(s);
	391	#else
	392	#error "no read_eflags"
	393	#endif
5ed44076	394
f9d8cd12 MD	395	if (max - min > 2)
	396	n = 0;
	397	else if (min < 0 \|\| max == 0)
	398	n = 0;
	399	else
	400	n = 1;
	401	if (bootverbose) {
e3869ec7	402	kprintf("ACPI timer looks %s min = %d, max = %d, width = %d\n",
f9d8cd12 MD	403	n ? "GOOD" : "BAD ",
	404	min, max, max - min);
	405	}
5ed44076	406
f9d8cd12 MD	407	return (n);
f9d8cd12 MD	408	}
5ed44076	409