| Current Path : /sys/dev/acpica/ |
FreeBSD hs32.drive.ne.jp 9.1-RELEASE FreeBSD 9.1-RELEASE #1: Wed Jan 14 12:18:08 JST 2015 root@hs32.drive.ne.jp:/sys/amd64/compile/hs32 amd64 |
| Current File : //sys/dev/acpica/acpi_throttle.c |
/*-
* Copyright (c) 2003-2005 Nate Lawson (SDG)
* Copyright (c) 2001 Michael Smith
* 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>
__FBSDID("$FreeBSD: release/9.1.0/sys/dev/acpica/acpi_throttle.c 193530 2009-06-05 18:44:36Z jkim $");
#include "opt_acpi.h"
#include <sys/param.h>
#include <sys/bus.h>
#include <sys/cpu.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/rman.h>
#include <machine/bus.h>
#include <contrib/dev/acpica/include/acpi.h>
#include <dev/acpica/acpivar.h>
#include <dev/pci/pcivar.h>
#include "cpufreq_if.h"
/*
* Throttling provides relative frequency control. It involves modulating
* the clock so that the CPU is active for only a fraction of the normal
* clock cycle. It does not change voltage and so is less efficient than
* other mechanisms. Since it is relative, it can be used in addition to
* absolute cpufreq drivers. We support the ACPI 2.0 specification.
*/
struct acpi_throttle_softc {
device_t cpu_dev;
ACPI_HANDLE cpu_handle;
uint32_t cpu_p_blk; /* ACPI P_BLK location */
uint32_t cpu_p_blk_len; /* P_BLK length (must be 6). */
struct resource *cpu_p_cnt; /* Throttling control register */
int cpu_p_type; /* Resource type for cpu_p_cnt. */
uint32_t cpu_thr_state; /* Current throttle setting. */
};
#define THR_GET_REG(reg) \
(bus_space_read_4(rman_get_bustag((reg)), \
rman_get_bushandle((reg)), 0))
#define THR_SET_REG(reg, val) \
(bus_space_write_4(rman_get_bustag((reg)), \
rman_get_bushandle((reg)), 0, (val)))
/*
* Speeds are stored in counts, from 1 to CPU_MAX_SPEED, and
* reported to the user in hundredths of a percent.
*/
#define CPU_MAX_SPEED (1 << cpu_duty_width)
#define CPU_SPEED_PERCENT(x) ((10000 * (x)) / CPU_MAX_SPEED)
#define CPU_SPEED_PRINTABLE(x) (CPU_SPEED_PERCENT(x) / 10), \
(CPU_SPEED_PERCENT(x) % 10)
#define CPU_P_CNT_THT_EN (1<<4)
#define CPU_QUIRK_NO_THROTTLE (1<<1) /* Throttling is not usable. */
#define PCI_VENDOR_INTEL 0x8086
#define PCI_DEVICE_82371AB_3 0x7113 /* PIIX4 chipset for quirks. */
#define PCI_REVISION_A_STEP 0
#define PCI_REVISION_B_STEP 1
static uint32_t cpu_duty_offset; /* Offset in P_CNT of throttle val. */
static uint32_t cpu_duty_width; /* Bit width of throttle value. */
static int thr_rid; /* Driver-wide resource id. */
static int thr_quirks; /* Indicate any hardware bugs. */
static void acpi_throttle_identify(driver_t *driver, device_t parent);
static int acpi_throttle_probe(device_t dev);
static int acpi_throttle_attach(device_t dev);
static int acpi_throttle_evaluate(struct acpi_throttle_softc *sc);
static int acpi_throttle_quirks(struct acpi_throttle_softc *sc);
static int acpi_thr_settings(device_t dev, struct cf_setting *sets,
int *count);
static int acpi_thr_set(device_t dev, const struct cf_setting *set);
static int acpi_thr_get(device_t dev, struct cf_setting *set);
static int acpi_thr_type(device_t dev, int *type);
static device_method_t acpi_throttle_methods[] = {
/* Device interface */
DEVMETHOD(device_identify, acpi_throttle_identify),
DEVMETHOD(device_probe, acpi_throttle_probe),
DEVMETHOD(device_attach, acpi_throttle_attach),
/* cpufreq interface */
DEVMETHOD(cpufreq_drv_set, acpi_thr_set),
DEVMETHOD(cpufreq_drv_get, acpi_thr_get),
DEVMETHOD(cpufreq_drv_type, acpi_thr_type),
DEVMETHOD(cpufreq_drv_settings, acpi_thr_settings),
{0, 0}
};
static driver_t acpi_throttle_driver = {
"acpi_throttle",
acpi_throttle_methods,
sizeof(struct acpi_throttle_softc),
};
static devclass_t acpi_throttle_devclass;
DRIVER_MODULE(acpi_throttle, cpu, acpi_throttle_driver, acpi_throttle_devclass,
0, 0);
static void
acpi_throttle_identify(driver_t *driver, device_t parent)
{
ACPI_BUFFER buf;
ACPI_HANDLE handle;
ACPI_OBJECT *obj;
/* Make sure we're not being doubly invoked. */
if (device_find_child(parent, "acpi_throttle", -1))
return;
/* Check for a valid duty width and parent CPU type. */
handle = acpi_get_handle(parent);
if (handle == NULL)
return;
if (AcpiGbl_FADT.DutyWidth == 0 ||
acpi_get_type(parent) != ACPI_TYPE_PROCESSOR)
return;
/*
* Add a child if there's a non-NULL P_BLK and correct length, or
* if the _PTC method is present.
*/
buf.Pointer = NULL;
buf.Length = ACPI_ALLOCATE_BUFFER;
if (ACPI_FAILURE(AcpiEvaluateObject(handle, NULL, NULL, &buf)))
return;
obj = (ACPI_OBJECT *)buf.Pointer;
if ((obj->Processor.PblkAddress && obj->Processor.PblkLength >= 4) ||
ACPI_SUCCESS(AcpiEvaluateObject(handle, "_PTC", NULL, NULL))) {
if (BUS_ADD_CHILD(parent, 0, "acpi_throttle", -1) == NULL)
device_printf(parent, "add throttle child failed\n");
}
AcpiOsFree(obj);
}
static int
acpi_throttle_probe(device_t dev)
{
if (resource_disabled("acpi_throttle", 0))
return (ENXIO);
/*
* On i386 platforms at least, ACPI throttling is accomplished by
* the chipset modulating the STPCLK# pin based on the duty cycle.
* Since p4tcc uses the same mechanism (but internal to the CPU),
* we disable acpi_throttle when p4tcc is also present.
*/
if (device_find_child(device_get_parent(dev), "p4tcc", -1) &&
!resource_disabled("p4tcc", 0))
return (ENXIO);
device_set_desc(dev, "ACPI CPU Throttling");
return (0);
}
static int
acpi_throttle_attach(device_t dev)
{
struct acpi_throttle_softc *sc;
struct cf_setting set;
ACPI_BUFFER buf;
ACPI_OBJECT *obj;
ACPI_STATUS status;
int error;
sc = device_get_softc(dev);
sc->cpu_dev = dev;
sc->cpu_handle = acpi_get_handle(dev);
buf.Pointer = NULL;
buf.Length = ACPI_ALLOCATE_BUFFER;
status = AcpiEvaluateObject(sc->cpu_handle, NULL, NULL, &buf);
if (ACPI_FAILURE(status)) {
device_printf(dev, "attach failed to get Processor obj - %s\n",
AcpiFormatException(status));
return (ENXIO);
}
obj = (ACPI_OBJECT *)buf.Pointer;
sc->cpu_p_blk = obj->Processor.PblkAddress;
sc->cpu_p_blk_len = obj->Processor.PblkLength;
AcpiOsFree(obj);
/* If this is the first device probed, check for quirks. */
if (device_get_unit(dev) == 0)
acpi_throttle_quirks(sc);
/* Attempt to attach the actual throttling register. */
error = acpi_throttle_evaluate(sc);
if (error)
return (error);
/*
* Set our initial frequency to the highest since some systems
* seem to boot with this at the lowest setting.
*/
set.freq = 10000;
acpi_thr_set(dev, &set);
/* Everything went ok, register with cpufreq(4). */
cpufreq_register(dev);
return (0);
}
static int
acpi_throttle_evaluate(struct acpi_throttle_softc *sc)
{
uint32_t duty_end;
ACPI_BUFFER buf;
ACPI_OBJECT obj;
ACPI_GENERIC_ADDRESS gas;
ACPI_STATUS status;
/* Get throttling parameters from the FADT. 0 means not supported. */
if (device_get_unit(sc->cpu_dev) == 0) {
cpu_duty_offset = AcpiGbl_FADT.DutyOffset;
cpu_duty_width = AcpiGbl_FADT.DutyWidth;
}
if (cpu_duty_width == 0 || (thr_quirks & CPU_QUIRK_NO_THROTTLE) != 0)
return (ENXIO);
/* Validate the duty offset/width. */
duty_end = cpu_duty_offset + cpu_duty_width - 1;
if (duty_end > 31) {
device_printf(sc->cpu_dev,
"CLK_VAL field overflows P_CNT register\n");
return (ENXIO);
}
if (cpu_duty_offset <= 4 && duty_end >= 4) {
device_printf(sc->cpu_dev,
"CLK_VAL field overlaps THT_EN bit\n");
return (ENXIO);
}
/*
* If not present, fall back to using the processor's P_BLK to find
* the P_CNT register.
*
* Note that some systems seem to duplicate the P_BLK pointer
* across multiple CPUs, so not getting the resource is not fatal.
*/
buf.Pointer = &obj;
buf.Length = sizeof(obj);
status = AcpiEvaluateObject(sc->cpu_handle, "_PTC", NULL, &buf);
if (ACPI_SUCCESS(status)) {
if (obj.Buffer.Length < sizeof(ACPI_GENERIC_ADDRESS) + 3) {
device_printf(sc->cpu_dev, "_PTC buffer too small\n");
return (ENXIO);
}
memcpy(&gas, obj.Buffer.Pointer + 3, sizeof(gas));
acpi_bus_alloc_gas(sc->cpu_dev, &sc->cpu_p_type, &thr_rid,
&gas, &sc->cpu_p_cnt, 0);
if (sc->cpu_p_cnt != NULL && bootverbose) {
device_printf(sc->cpu_dev, "P_CNT from _PTC %#jx\n",
gas.Address);
}
}
/* If _PTC not present or other failure, try the P_BLK. */
if (sc->cpu_p_cnt == NULL) {
/*
* The spec says P_BLK must be 6 bytes long. However, some
* systems use it to indicate a fractional set of features
* present so we take anything >= 4.
*/
if (sc->cpu_p_blk_len < 4)
return (ENXIO);
gas.Address = sc->cpu_p_blk;
gas.SpaceId = ACPI_ADR_SPACE_SYSTEM_IO;
gas.BitWidth = 32;
acpi_bus_alloc_gas(sc->cpu_dev, &sc->cpu_p_type, &thr_rid,
&gas, &sc->cpu_p_cnt, 0);
if (sc->cpu_p_cnt != NULL) {
if (bootverbose)
device_printf(sc->cpu_dev,
"P_CNT from P_BLK %#x\n", sc->cpu_p_blk);
} else {
device_printf(sc->cpu_dev, "failed to attach P_CNT\n");
return (ENXIO);
}
}
thr_rid++;
return (0);
}
static int
acpi_throttle_quirks(struct acpi_throttle_softc *sc)
{
device_t acpi_dev;
/* Look for various quirks of the PIIX4 part. */
acpi_dev = pci_find_device(PCI_VENDOR_INTEL, PCI_DEVICE_82371AB_3);
if (acpi_dev) {
switch (pci_get_revid(acpi_dev)) {
/*
* Disable throttling control on PIIX4 A and B-step.
* See specification changes #13 ("Manual Throttle Duty Cycle")
* and #14 ("Enabling and Disabling Manual Throttle"), plus
* erratum #5 ("STPCLK# Deassertion Time") from the January
* 2002 PIIX4 specification update. Note that few (if any)
* mobile systems ever used this part.
*/
case PCI_REVISION_A_STEP:
case PCI_REVISION_B_STEP:
thr_quirks |= CPU_QUIRK_NO_THROTTLE;
break;
default:
break;
}
}
return (0);
}
static int
acpi_thr_settings(device_t dev, struct cf_setting *sets, int *count)
{
int i, speed;
if (sets == NULL || count == NULL)
return (EINVAL);
if (*count < CPU_MAX_SPEED)
return (E2BIG);
/* Return a list of valid settings for this driver. */
memset(sets, CPUFREQ_VAL_UNKNOWN, sizeof(*sets) * CPU_MAX_SPEED);
for (i = 0, speed = CPU_MAX_SPEED; speed != 0; i++, speed--) {
sets[i].freq = CPU_SPEED_PERCENT(speed);
sets[i].dev = dev;
}
*count = CPU_MAX_SPEED;
return (0);
}
static int
acpi_thr_set(device_t dev, const struct cf_setting *set)
{
struct acpi_throttle_softc *sc;
uint32_t clk_val, p_cnt, speed;
if (set == NULL)
return (EINVAL);
sc = device_get_softc(dev);
/*
* Validate requested state converts to a duty cycle that is an
* integer from [1 .. CPU_MAX_SPEED].
*/
speed = set->freq * CPU_MAX_SPEED / 10000;
if (speed * 10000 != set->freq * CPU_MAX_SPEED ||
speed < 1 || speed > CPU_MAX_SPEED)
return (EINVAL);
/* If we're at this setting, don't bother applying it again. */
if (speed == sc->cpu_thr_state)
return (0);
/* Get the current P_CNT value and disable throttling */
p_cnt = THR_GET_REG(sc->cpu_p_cnt);
p_cnt &= ~CPU_P_CNT_THT_EN;
THR_SET_REG(sc->cpu_p_cnt, p_cnt);
/* If we're at maximum speed, that's all */
if (speed < CPU_MAX_SPEED) {
/* Mask the old CLK_VAL off and OR in the new value */
clk_val = (CPU_MAX_SPEED - 1) << cpu_duty_offset;
p_cnt &= ~clk_val;
p_cnt |= (speed << cpu_duty_offset);
/* Write the new P_CNT value and then enable throttling */
THR_SET_REG(sc->cpu_p_cnt, p_cnt);
p_cnt |= CPU_P_CNT_THT_EN;
THR_SET_REG(sc->cpu_p_cnt, p_cnt);
}
sc->cpu_thr_state = speed;
return (0);
}
static int
acpi_thr_get(device_t dev, struct cf_setting *set)
{
struct acpi_throttle_softc *sc;
uint32_t p_cnt, clk_val;
if (set == NULL)
return (EINVAL);
sc = device_get_softc(dev);
/* Get the current throttling setting from P_CNT. */
p_cnt = THR_GET_REG(sc->cpu_p_cnt);
clk_val = (p_cnt >> cpu_duty_offset) & (CPU_MAX_SPEED - 1);
sc->cpu_thr_state = clk_val;
memset(set, CPUFREQ_VAL_UNKNOWN, sizeof(*set));
set->freq = CPU_SPEED_PERCENT(clk_val);
set->dev = dev;
return (0);
}
static int
acpi_thr_type(device_t dev, int *type)
{
if (type == NULL)
return (EINVAL);
*type = CPUFREQ_TYPE_RELATIVE;
return (0);
}