freebsd-dev/sys/x86/cpufreq/hwpstate_amd.c
Conrad Meyer 43524989c5 hwpstate(4): Ignore CurPstateLimit by default
Add a sysctl knob to allow users to re-enable it, and document the knob and
default in cpufreq.4.  (While here, add a few unrelated updates to
cpufreq.4.)

It seems that the register value in some hardware simply reflects the
configured P-state.  This results in an inadvertent and unintended outcome
where the P-state can only walk down, and then the driver becomes "stuck" in
the slowest possible P-state.

The Linux driver never consults this register, so that's some evidence that
ignoring the contents are relatively harmless.

PR:		234733
Reported by:	sigsys AT gmail.com, Erich Dollanksy <freebsd.ed.lists AT
		sumeritec.com>
2020-01-31 17:40:41 +00:00

556 lines
14 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2005 Nate Lawson
* Copyright (c) 2004 Colin Percival
* Copyright (c) 2004-2005 Bruno Durcot
* Copyright (c) 2004 FUKUDA Nobuhiko
* Copyright (c) 2009 Michael Reifenberger
* Copyright (c) 2009 Norikatsu Shigemura
* Copyright (c) 2008-2009 Gen Otsuji
*
* This code is depending on kern_cpu.c, est.c, powernow.c, p4tcc.c, smist.c
* in various parts. The authors of these files are Nate Lawson,
* Colin Percival, Bruno Durcot, and FUKUDA Nobuhiko.
* This code contains patches by Michael Reifenberger and Norikatsu Shigemura.
* Thank you.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted providing 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``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 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.
*/
/*
* For more info:
* BIOS and Kernel Developer's Guide(BKDG) for AMD Family 10h Processors
* 31116 Rev 3.20 February 04, 2009
* BIOS and Kernel Developer's Guide(BKDG) for AMD Family 11h Processors
* 41256 Rev 3.00 - July 07, 2008
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/bus.h>
#include <sys/cpu.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/malloc.h>
#include <sys/proc.h>
#include <sys/pcpu.h>
#include <sys/smp.h>
#include <sys/sched.h>
#include <machine/md_var.h>
#include <machine/cputypes.h>
#include <machine/specialreg.h>
#include <contrib/dev/acpica/include/acpi.h>
#include <dev/acpica/acpivar.h>
#include "acpi_if.h"
#include "cpufreq_if.h"
#define MSR_AMD_10H_11H_LIMIT 0xc0010061
#define MSR_AMD_10H_11H_CONTROL 0xc0010062
#define MSR_AMD_10H_11H_STATUS 0xc0010063
#define MSR_AMD_10H_11H_CONFIG 0xc0010064
#define AMD_10H_11H_MAX_STATES 16
/* for MSR_AMD_10H_11H_LIMIT C001_0061 */
#define AMD_10H_11H_GET_PSTATE_MAX_VAL(msr) (((msr) >> 4) & 0x7)
#define AMD_10H_11H_GET_PSTATE_LIMIT(msr) (((msr)) & 0x7)
/* for MSR_AMD_10H_11H_CONFIG 10h:C001_0064:68 / 11h:C001_0064:6B */
#define AMD_10H_11H_CUR_VID(msr) (((msr) >> 9) & 0x7F)
#define AMD_10H_11H_CUR_DID(msr) (((msr) >> 6) & 0x07)
#define AMD_10H_11H_CUR_FID(msr) ((msr) & 0x3F)
#define AMD_17H_CUR_VID(msr) (((msr) >> 14) & 0xFF)
#define AMD_17H_CUR_DID(msr) (((msr) >> 8) & 0x3F)
#define AMD_17H_CUR_FID(msr) ((msr) & 0xFF)
#define HWPSTATE_DEBUG(dev, msg...) \
do { \
if (hwpstate_verbose) \
device_printf(dev, msg); \
} while (0)
struct hwpstate_setting {
int freq; /* CPU clock in Mhz or 100ths of a percent. */
int volts; /* Voltage in mV. */
int power; /* Power consumed in mW. */
int lat; /* Transition latency in us. */
int pstate_id; /* P-State id */
};
struct hwpstate_softc {
device_t dev;
struct hwpstate_setting hwpstate_settings[AMD_10H_11H_MAX_STATES];
int cfnum;
};
static void hwpstate_identify(driver_t *driver, device_t parent);
static int hwpstate_probe(device_t dev);
static int hwpstate_attach(device_t dev);
static int hwpstate_detach(device_t dev);
static int hwpstate_set(device_t dev, const struct cf_setting *cf);
static int hwpstate_get(device_t dev, struct cf_setting *cf);
static int hwpstate_settings(device_t dev, struct cf_setting *sets, int *count);
static int hwpstate_type(device_t dev, int *type);
static int hwpstate_shutdown(device_t dev);
static int hwpstate_features(driver_t *driver, u_int *features);
static int hwpstate_get_info_from_acpi_perf(device_t dev, device_t perf_dev);
static int hwpstate_get_info_from_msr(device_t dev);
static int hwpstate_goto_pstate(device_t dev, int pstate_id);
static int hwpstate_verbose;
SYSCTL_INT(_debug, OID_AUTO, hwpstate_verbose, CTLFLAG_RWTUN,
&hwpstate_verbose, 0, "Debug hwpstate");
static int hwpstate_verify;
SYSCTL_INT(_debug, OID_AUTO, hwpstate_verify, CTLFLAG_RWTUN,
&hwpstate_verify, 0, "Verify P-state after setting");
static bool hwpstate_pstate_limit;
SYSCTL_BOOL(_debug, OID_AUTO, hwpstate_pstate_limit, CTLFLAG_RWTUN,
&hwpstate_pstate_limit, 0,
"If enabled (1), limit administrative control of P-states to the value in "
"CurPstateLimit");
static device_method_t hwpstate_methods[] = {
/* Device interface */
DEVMETHOD(device_identify, hwpstate_identify),
DEVMETHOD(device_probe, hwpstate_probe),
DEVMETHOD(device_attach, hwpstate_attach),
DEVMETHOD(device_detach, hwpstate_detach),
DEVMETHOD(device_shutdown, hwpstate_shutdown),
/* cpufreq interface */
DEVMETHOD(cpufreq_drv_set, hwpstate_set),
DEVMETHOD(cpufreq_drv_get, hwpstate_get),
DEVMETHOD(cpufreq_drv_settings, hwpstate_settings),
DEVMETHOD(cpufreq_drv_type, hwpstate_type),
/* ACPI interface */
DEVMETHOD(acpi_get_features, hwpstate_features),
{0, 0}
};
static devclass_t hwpstate_devclass;
static driver_t hwpstate_driver = {
"hwpstate",
hwpstate_methods,
sizeof(struct hwpstate_softc),
};
DRIVER_MODULE(hwpstate, cpu, hwpstate_driver, hwpstate_devclass, 0, 0);
/*
* Go to Px-state on all cpus, considering the limit register (if so
* configured).
*/
static int
hwpstate_goto_pstate(device_t dev, int id)
{
sbintime_t sbt;
uint64_t msr;
int cpu, i, j, limit;
if (hwpstate_pstate_limit) {
/* get the current pstate limit */
msr = rdmsr(MSR_AMD_10H_11H_LIMIT);
limit = AMD_10H_11H_GET_PSTATE_LIMIT(msr);
if (limit > id) {
HWPSTATE_DEBUG(dev, "Restricting requested P%d to P%d "
"due to HW limit\n", id, limit);
id = limit;
}
}
cpu = curcpu;
HWPSTATE_DEBUG(dev, "setting P%d-state on cpu%d\n", id, cpu);
/* Go To Px-state */
wrmsr(MSR_AMD_10H_11H_CONTROL, id);
/*
* We are going to the same Px-state on all cpus.
* Probably should take _PSD into account.
*/
CPU_FOREACH(i) {
if (i == cpu)
continue;
/* Bind to each cpu. */
thread_lock(curthread);
sched_bind(curthread, i);
thread_unlock(curthread);
HWPSTATE_DEBUG(dev, "setting P%d-state on cpu%d\n", id, i);
/* Go To Px-state */
wrmsr(MSR_AMD_10H_11H_CONTROL, id);
}
/*
* Verify whether each core is in the requested P-state.
*/
if (hwpstate_verify) {
CPU_FOREACH(i) {
thread_lock(curthread);
sched_bind(curthread, i);
thread_unlock(curthread);
/* wait loop (100*100 usec is enough ?) */
for (j = 0; j < 100; j++) {
/* get the result. not assure msr=id */
msr = rdmsr(MSR_AMD_10H_11H_STATUS);
if (msr == id)
break;
sbt = SBT_1MS / 10;
tsleep_sbt(dev, PZERO, "pstate_goto", sbt,
sbt >> tc_precexp, 0);
}
HWPSTATE_DEBUG(dev, "result: P%d-state on cpu%d\n",
(int)msr, i);
if (msr != id) {
HWPSTATE_DEBUG(dev,
"error: loop is not enough.\n");
return (ENXIO);
}
}
}
return (0);
}
static int
hwpstate_set(device_t dev, const struct cf_setting *cf)
{
struct hwpstate_softc *sc;
struct hwpstate_setting *set;
int i;
if (cf == NULL)
return (EINVAL);
sc = device_get_softc(dev);
set = sc->hwpstate_settings;
for (i = 0; i < sc->cfnum; i++)
if (CPUFREQ_CMP(cf->freq, set[i].freq))
break;
if (i == sc->cfnum)
return (EINVAL);
return (hwpstate_goto_pstate(dev, set[i].pstate_id));
}
static int
hwpstate_get(device_t dev, struct cf_setting *cf)
{
struct hwpstate_softc *sc;
struct hwpstate_setting set;
uint64_t msr;
sc = device_get_softc(dev);
if (cf == NULL)
return (EINVAL);
msr = rdmsr(MSR_AMD_10H_11H_STATUS);
if (msr >= sc->cfnum)
return (EINVAL);
set = sc->hwpstate_settings[msr];
cf->freq = set.freq;
cf->volts = set.volts;
cf->power = set.power;
cf->lat = set.lat;
cf->dev = dev;
return (0);
}
static int
hwpstate_settings(device_t dev, struct cf_setting *sets, int *count)
{
struct hwpstate_softc *sc;
struct hwpstate_setting set;
int i;
if (sets == NULL || count == NULL)
return (EINVAL);
sc = device_get_softc(dev);
if (*count < sc->cfnum)
return (E2BIG);
for (i = 0; i < sc->cfnum; i++, sets++) {
set = sc->hwpstate_settings[i];
sets->freq = set.freq;
sets->volts = set.volts;
sets->power = set.power;
sets->lat = set.lat;
sets->dev = dev;
}
*count = sc->cfnum;
return (0);
}
static int
hwpstate_type(device_t dev, int *type)
{
if (type == NULL)
return (EINVAL);
*type = CPUFREQ_TYPE_ABSOLUTE;
return (0);
}
static void
hwpstate_identify(driver_t *driver, device_t parent)
{
if (device_find_child(parent, "hwpstate", -1) != NULL)
return;
if ((cpu_vendor_id != CPU_VENDOR_AMD || CPUID_TO_FAMILY(cpu_id) < 0x10) &&
cpu_vendor_id != CPU_VENDOR_HYGON)
return;
/*
* Check if hardware pstate enable bit is set.
*/
if ((amd_pminfo & AMDPM_HW_PSTATE) == 0) {
HWPSTATE_DEBUG(parent, "hwpstate enable bit is not set.\n");
return;
}
if (resource_disabled("hwpstate", 0))
return;
if (BUS_ADD_CHILD(parent, 10, "hwpstate", -1) == NULL)
device_printf(parent, "hwpstate: add child failed\n");
}
static int
hwpstate_probe(device_t dev)
{
struct hwpstate_softc *sc;
device_t perf_dev;
uint64_t msr;
int error, type;
/*
* Only hwpstate0.
* It goes well with acpi_throttle.
*/
if (device_get_unit(dev) != 0)
return (ENXIO);
sc = device_get_softc(dev);
sc->dev = dev;
/*
* Check if acpi_perf has INFO only flag.
*/
perf_dev = device_find_child(device_get_parent(dev), "acpi_perf", -1);
error = TRUE;
if (perf_dev && device_is_attached(perf_dev)) {
error = CPUFREQ_DRV_TYPE(perf_dev, &type);
if (error == 0) {
if ((type & CPUFREQ_FLAG_INFO_ONLY) == 0) {
/*
* If acpi_perf doesn't have INFO_ONLY flag,
* it will take care of pstate transitions.
*/
HWPSTATE_DEBUG(dev, "acpi_perf will take care of pstate transitions.\n");
return (ENXIO);
} else {
/*
* If acpi_perf has INFO_ONLY flag, (_PCT has FFixedHW)
* we can get _PSS info from acpi_perf
* without going into ACPI.
*/
HWPSTATE_DEBUG(dev, "going to fetch info from acpi_perf\n");
error = hwpstate_get_info_from_acpi_perf(dev, perf_dev);
}
}
}
if (error == 0) {
/*
* Now we get _PSS info from acpi_perf without error.
* Let's check it.
*/
msr = rdmsr(MSR_AMD_10H_11H_LIMIT);
if (sc->cfnum != 1 + AMD_10H_11H_GET_PSTATE_MAX_VAL(msr)) {
HWPSTATE_DEBUG(dev, "MSR (%jd) and ACPI _PSS (%d)"
" count mismatch\n", (intmax_t)msr, sc->cfnum);
error = TRUE;
}
}
/*
* If we cannot get info from acpi_perf,
* Let's get info from MSRs.
*/
if (error)
error = hwpstate_get_info_from_msr(dev);
if (error)
return (error);
device_set_desc(dev, "Cool`n'Quiet 2.0");
return (0);
}
static int
hwpstate_attach(device_t dev)
{
return (cpufreq_register(dev));
}
static int
hwpstate_get_info_from_msr(device_t dev)
{
struct hwpstate_softc *sc;
struct hwpstate_setting *hwpstate_set;
uint64_t msr;
int family, i, fid, did;
family = CPUID_TO_FAMILY(cpu_id);
sc = device_get_softc(dev);
/* Get pstate count */
msr = rdmsr(MSR_AMD_10H_11H_LIMIT);
sc->cfnum = 1 + AMD_10H_11H_GET_PSTATE_MAX_VAL(msr);
hwpstate_set = sc->hwpstate_settings;
for (i = 0; i < sc->cfnum; i++) {
msr = rdmsr(MSR_AMD_10H_11H_CONFIG + i);
if ((msr & ((uint64_t)1 << 63)) == 0) {
HWPSTATE_DEBUG(dev, "msr is not valid.\n");
return (ENXIO);
}
did = AMD_10H_11H_CUR_DID(msr);
fid = AMD_10H_11H_CUR_FID(msr);
/* Convert fid/did to frequency. */
switch (family) {
case 0x11:
hwpstate_set[i].freq = (100 * (fid + 0x08)) >> did;
break;
case 0x10:
case 0x12:
case 0x15:
case 0x16:
hwpstate_set[i].freq = (100 * (fid + 0x10)) >> did;
break;
case 0x17:
case 0x18:
did = AMD_17H_CUR_DID(msr);
if (did == 0) {
HWPSTATE_DEBUG(dev, "unexpected did: 0\n");
did = 1;
}
fid = AMD_17H_CUR_FID(msr);
hwpstate_set[i].freq = (200 * fid) / did;
break;
default:
HWPSTATE_DEBUG(dev, "get_info_from_msr: %s family"
" 0x%02x CPUs are not supported yet\n",
cpu_vendor_id == CPU_VENDOR_HYGON ? "Hygon" : "AMD",
family);
return (ENXIO);
}
hwpstate_set[i].pstate_id = i;
/* There was volts calculation, but deleted it. */
hwpstate_set[i].volts = CPUFREQ_VAL_UNKNOWN;
hwpstate_set[i].power = CPUFREQ_VAL_UNKNOWN;
hwpstate_set[i].lat = CPUFREQ_VAL_UNKNOWN;
}
return (0);
}
static int
hwpstate_get_info_from_acpi_perf(device_t dev, device_t perf_dev)
{
struct hwpstate_softc *sc;
struct cf_setting *perf_set;
struct hwpstate_setting *hwpstate_set;
int count, error, i;
perf_set = malloc(MAX_SETTINGS * sizeof(*perf_set), M_TEMP, M_NOWAIT);
if (perf_set == NULL) {
HWPSTATE_DEBUG(dev, "nomem\n");
return (ENOMEM);
}
/*
* Fetch settings from acpi_perf.
* Now it is attached, and has info only flag.
*/
count = MAX_SETTINGS;
error = CPUFREQ_DRV_SETTINGS(perf_dev, perf_set, &count);
if (error) {
HWPSTATE_DEBUG(dev, "error: CPUFREQ_DRV_SETTINGS.\n");
goto out;
}
sc = device_get_softc(dev);
sc->cfnum = count;
hwpstate_set = sc->hwpstate_settings;
for (i = 0; i < count; i++) {
if (i == perf_set[i].spec[0]) {
hwpstate_set[i].pstate_id = i;
hwpstate_set[i].freq = perf_set[i].freq;
hwpstate_set[i].volts = perf_set[i].volts;
hwpstate_set[i].power = perf_set[i].power;
hwpstate_set[i].lat = perf_set[i].lat;
} else {
HWPSTATE_DEBUG(dev, "ACPI _PSS object mismatch.\n");
error = ENXIO;
goto out;
}
}
out:
if (perf_set)
free(perf_set, M_TEMP);
return (error);
}
static int
hwpstate_detach(device_t dev)
{
hwpstate_goto_pstate(dev, 0);
return (cpufreq_unregister(dev));
}
static int
hwpstate_shutdown(device_t dev)
{
/* hwpstate_goto_pstate(dev, 0); */
return (0);
}
static int
hwpstate_features(driver_t *driver, u_int *features)
{
/* Notify the ACPI CPU that we support direct access to MSRs */
*features = ACPI_CAP_PERF_MSRS;
return (0);
}