freebsd-dev/sys/dev/cpufreq/ichss.c

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/*-
* Copyright (c) 2004-2005 Nate Lawson (SDG)
* 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("$FreeBSD$");
#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/pcpu.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
#include <dev/pci/pcivar.h>
#include <machine/bus.h>
#include <machine/resource.h>
#include <sys/rman.h>
#include "cpufreq_if.h"
/*
* The SpeedStep ICH feature is a chipset-initiated voltage and frequency
* transition available on the ICH2M, 3M, and 4M. It is different from
* the newer Pentium-M SpeedStep feature. It offers only two levels of
* frequency/voltage. Often, the BIOS will select one of the levels via
* SMM code during the power-on process (i.e., choose a lower level if the
* system is off AC power.)
*/
struct ichss_softc {
device_t dev;
int bm_rid; /* Bus-mastering control (PM2REG). */
struct resource *bm_reg;
int ctrl_rid; /* Control/status register. */
struct resource *ctrl_reg;
struct cf_setting sets[2]; /* Only two settings. */
};
/* Supported PCI IDs. */
#define PCI_VENDOR_INTEL 0x8086
#define PCI_DEV_82801BA 0x244c /* ICH2M */
#define PCI_DEV_82801CA 0x248c /* ICH3M */
#define PCI_DEV_82801DB 0x24cc /* ICH4M */
#define PCI_DEV_82815_MC 0x1130 /* Unsupported/buggy part */
/* PCI config registers for finding PMBASE and enabling SpeedStep. */
#define ICHSS_PMBASE_OFFSET 0x40
#define ICHSS_PMCFG_OFFSET 0xa0
/* Values and masks. */
#define ICHSS_ENABLE (1<<3) /* Enable SpeedStep control. */
#define ICHSS_IO_REG 0x1 /* Access register via I/O space. */
#define ICHSS_PMBASE_MASK 0xff80 /* PMBASE address bits. */
#define ICHSS_CTRL_BIT 0x1 /* 0 is high speed, 1 is low. */
#define ICHSS_BM_DISABLE 0x1
/* Offsets from PMBASE for various registers. */
#define ICHSS_BM_OFFSET 0x20
#define ICHSS_CTRL_OFFSET 0x50
#define ICH_GET_REG(reg) \
(bus_space_read_1(rman_get_bustag((reg)), \
rman_get_bushandle((reg)), 0))
#define ICH_SET_REG(reg, val) \
(bus_space_write_1(rman_get_bustag((reg)), \
rman_get_bushandle((reg)), 0, (val)))
static void ichss_identify(driver_t *driver, device_t parent);
static int ichss_probe(device_t dev);
static int ichss_attach(device_t dev);
static int ichss_detach(device_t dev);
static int ichss_settings(device_t dev, struct cf_setting *sets,
int *count);
static int ichss_set(device_t dev, const struct cf_setting *set);
static int ichss_get(device_t dev, struct cf_setting *set);
static int ichss_type(device_t dev, int *type);
static device_method_t ichss_methods[] = {
/* Device interface */
DEVMETHOD(device_identify, ichss_identify),
DEVMETHOD(device_probe, ichss_probe),
DEVMETHOD(device_attach, ichss_attach),
DEVMETHOD(device_detach, ichss_detach),
/* cpufreq interface */
DEVMETHOD(cpufreq_drv_set, ichss_set),
DEVMETHOD(cpufreq_drv_get, ichss_get),
DEVMETHOD(cpufreq_drv_type, ichss_type),
DEVMETHOD(cpufreq_drv_settings, ichss_settings),
DEVMETHOD_END
};
static driver_t ichss_driver = {
"ichss", ichss_methods, sizeof(struct ichss_softc)
};
static devclass_t ichss_devclass;
DRIVER_MODULE(ichss, cpu, ichss_driver, ichss_devclass, 0, 0);
static device_t ich_device;
#if 0
#define DPRINT(x...) printf(x)
#else
#define DPRINT(x...)
#endif
static void
ichss_identify(driver_t *driver, device_t parent)
{
device_t child;
uint32_t pmbase;
if (resource_disabled("ichss", 0))
return;
/*
* It appears that ICH SpeedStep only requires a single CPU to
* set the value (since the chipset is shared by all CPUs.)
* Thus, we only add a child to cpu 0.
*/
if (device_get_unit(parent) != 0)
return;
/* Avoid duplicates. */
if (device_find_child(parent, "ichss", -1))
return;
/*
* ICH2/3/4-M I/O Controller Hub is at bus 0, slot 1F, function 0.
* E.g. see Section 6.1 "PCI Devices and Functions" and table 6.1 of
* Intel(r) 82801BA I/O Controller Hub 2 (ICH2) and Intel(r) 82801BAM
* I/O Controller Hub 2 Mobile (ICH2-M).
*/
ich_device = pci_find_bsf(0, 0x1f, 0);
if (ich_device == NULL ||
pci_get_vendor(ich_device) != PCI_VENDOR_INTEL ||
(pci_get_device(ich_device) != PCI_DEV_82801BA &&
pci_get_device(ich_device) != PCI_DEV_82801CA &&
pci_get_device(ich_device) != PCI_DEV_82801DB))
return;
/*
* Certain systems with ICH2 and an Intel 82815_MC host bridge
* where the host bridge's revision is < 5 lockup if SpeedStep
* is used.
*/
if (pci_get_device(ich_device) == PCI_DEV_82801BA) {
device_t hostb;
hostb = pci_find_bsf(0, 0, 0);
if (hostb != NULL &&
pci_get_vendor(hostb) == PCI_VENDOR_INTEL &&
pci_get_device(hostb) == PCI_DEV_82815_MC &&
pci_get_revid(hostb) < 5)
return;
}
/* Find the PMBASE register from our PCI config header. */
pmbase = pci_read_config(ich_device, ICHSS_PMBASE_OFFSET,
sizeof(pmbase));
if ((pmbase & ICHSS_IO_REG) == 0) {
printf("ichss: invalid PMBASE memory type\n");
return;
}
pmbase &= ICHSS_PMBASE_MASK;
if (pmbase == 0) {
printf("ichss: invalid zero PMBASE address\n");
return;
}
DPRINT("ichss: PMBASE is %#x\n", pmbase);
child = BUS_ADD_CHILD(parent, 20, "ichss", 0);
if (child == NULL) {
device_printf(parent, "add SpeedStep child failed\n");
return;
}
/* Add the bus master arbitration and control registers. */
bus_set_resource(child, SYS_RES_IOPORT, 0, pmbase + ICHSS_BM_OFFSET,
1);
bus_set_resource(child, SYS_RES_IOPORT, 1, pmbase + ICHSS_CTRL_OFFSET,
1);
}
static int
ichss_probe(device_t dev)
{
device_t est_dev, perf_dev;
int error, type;
/*
* If the ACPI perf driver has attached and is not just offering
* info, let it manage things. Also, if Enhanced SpeedStep is
* available, don't attach.
*/
perf_dev = device_find_child(device_get_parent(dev), "acpi_perf", -1);
if (perf_dev && device_is_attached(perf_dev)) {
error = CPUFREQ_DRV_TYPE(perf_dev, &type);
if (error == 0 && (type & CPUFREQ_FLAG_INFO_ONLY) == 0)
return (ENXIO);
}
est_dev = device_find_child(device_get_parent(dev), "est", -1);
if (est_dev && device_is_attached(est_dev))
return (ENXIO);
device_set_desc(dev, "SpeedStep ICH");
return (-1000);
}
static int
ichss_attach(device_t dev)
{
struct ichss_softc *sc;
uint16_t ss_en;
sc = device_get_softc(dev);
sc->dev = dev;
sc->bm_rid = 0;
sc->bm_reg = bus_alloc_resource_any(dev, SYS_RES_IOPORT, &sc->bm_rid,
RF_ACTIVE);
if (sc->bm_reg == NULL) {
device_printf(dev, "failed to alloc BM arb register\n");
return (ENXIO);
}
sc->ctrl_rid = 1;
sc->ctrl_reg = bus_alloc_resource_any(dev, SYS_RES_IOPORT,
&sc->ctrl_rid, RF_ACTIVE);
if (sc->ctrl_reg == NULL) {
device_printf(dev, "failed to alloc control register\n");
bus_release_resource(dev, SYS_RES_IOPORT, sc->bm_rid,
sc->bm_reg);
return (ENXIO);
}
/* Activate SpeedStep control if not already enabled. */
ss_en = pci_read_config(ich_device, ICHSS_PMCFG_OFFSET, sizeof(ss_en));
if ((ss_en & ICHSS_ENABLE) == 0) {
device_printf(dev, "enabling SpeedStep support\n");
pci_write_config(ich_device, ICHSS_PMCFG_OFFSET,
ss_en | ICHSS_ENABLE, sizeof(ss_en));
}
/* Setup some defaults for our exported settings. */
sc->sets[0].freq = CPUFREQ_VAL_UNKNOWN;
sc->sets[0].volts = CPUFREQ_VAL_UNKNOWN;
sc->sets[0].power = CPUFREQ_VAL_UNKNOWN;
sc->sets[0].lat = 1000;
sc->sets[0].dev = dev;
sc->sets[1] = sc->sets[0];
cpufreq_register(dev);
return (0);
}
static int
ichss_detach(device_t dev)
{
/* TODO: teardown BM and CTRL registers. */
return (ENXIO);
}
static int
ichss_settings(device_t dev, struct cf_setting *sets, int *count)
{
struct ichss_softc *sc;
struct cf_setting set;
int first, i;
if (sets == NULL || count == NULL)
return (EINVAL);
if (*count < 2) {
*count = 2;
return (E2BIG);
}
sc = device_get_softc(dev);
/*
* Estimate frequencies for both levels, temporarily switching to
* the other one if we haven't calibrated it yet.
*/
ichss_get(dev, &set);
for (i = 0; i < 2; i++) {
if (sc->sets[i].freq == CPUFREQ_VAL_UNKNOWN) {
first = (i == 0) ? 1 : 0;
ichss_set(dev, &sc->sets[i]);
ichss_set(dev, &sc->sets[first]);
}
}
bcopy(sc->sets, sets, sizeof(sc->sets));
*count = 2;
return (0);
}
static int
ichss_set(device_t dev, const struct cf_setting *set)
{
struct ichss_softc *sc;
uint8_t bmval, new_val, old_val, req_val;
uint64_t rate;
register_t regs;
/* Look up appropriate bit value based on frequency. */
sc = device_get_softc(dev);
if (CPUFREQ_CMP(set->freq, sc->sets[0].freq))
req_val = 0;
else if (CPUFREQ_CMP(set->freq, sc->sets[1].freq))
req_val = ICHSS_CTRL_BIT;
else
return (EINVAL);
DPRINT("ichss: requested setting %d\n", req_val);
/* Disable interrupts and get the other register contents. */
regs = intr_disable();
old_val = ICH_GET_REG(sc->ctrl_reg) & ~ICHSS_CTRL_BIT;
/*
* Disable bus master arbitration, write the new value to the control
* register, and then re-enable bus master arbitration.
*/
bmval = ICH_GET_REG(sc->bm_reg) | ICHSS_BM_DISABLE;
ICH_SET_REG(sc->bm_reg, bmval);
ICH_SET_REG(sc->ctrl_reg, old_val | req_val);
ICH_SET_REG(sc->bm_reg, bmval & ~ICHSS_BM_DISABLE);
/* Get the new value and re-enable interrupts. */
new_val = ICH_GET_REG(sc->ctrl_reg);
intr_restore(regs);
/* Check if the desired state was indeed selected. */
if (req_val != (new_val & ICHSS_CTRL_BIT)) {
device_printf(sc->dev, "transition to %d failed\n", req_val);
return (ENXIO);
}
/* Re-initialize our cycle counter if we don't know this new state. */
if (sc->sets[req_val].freq == CPUFREQ_VAL_UNKNOWN) {
cpu_est_clockrate(0, &rate);
sc->sets[req_val].freq = rate / 1000000;
DPRINT("ichss: set calibrated new rate of %d\n",
sc->sets[req_val].freq);
}
return (0);
}
static int
ichss_get(device_t dev, struct cf_setting *set)
{
struct ichss_softc *sc;
uint64_t rate;
uint8_t state;
sc = device_get_softc(dev);
state = ICH_GET_REG(sc->ctrl_reg) & ICHSS_CTRL_BIT;
/* If we haven't changed settings yet, estimate the current value. */
if (sc->sets[state].freq == CPUFREQ_VAL_UNKNOWN) {
cpu_est_clockrate(0, &rate);
sc->sets[state].freq = rate / 1000000;
DPRINT("ichss: get calibrated new rate of %d\n",
sc->sets[state].freq);
}
*set = sc->sets[state];
return (0);
}
static int
ichss_type(device_t dev, int *type)
{
if (type == NULL)
return (EINVAL);
*type = CPUFREQ_TYPE_ABSOLUTE;
return (0);
}