freebsd-dev/sys/powerpc/cpufreq/pmcr.c
Conrad Meyer d86e0b338f pmcr: Fix pstate setting on Power8
Fix p-state setting on Power8 by removing the accidental double-indirection of
the pstate_ids table.

The pstate_ids table comes from the OF property "ibm,pstate-ids."  On Power9,
the values happen to be identical to the indices, so the extra indirection was
harmless.  On Power8, the values were out of the range [0, npstates], so
pmcr_set() would fail the spec[0] range check with EINVAL.

While here, include both the value and index in the driver-specific register
array as spec[0] and spec[1] respectively.  They're redundant, but relatively
harmless, and it may aid debugging.

While here, fix the range check to exclude the index npstates, which is one
past the last valid index.

PR:		233693
Reported and tested by:	sbruno
Reviewed by:	jhibbits
2018-12-01 21:37:47 +00:00

249 lines
5.8 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2018 Justin Hibbits
*
* 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 ``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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/cpu.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <dev/ofw/openfirm.h>
#include "cpufreq_if.h"
static int pstate_ids[256];
static int pstate_freqs[256];
static int npstates;
static void parse_pstates(void)
{
phandle_t node;
node = OF_finddevice("/ibm,opal/power-mgt");
/* If this fails, npstates will remain 0, and any attachment will bail. */
if (node == -1)
return;
npstates = OF_getencprop(node, "ibm,pstate-ids", pstate_ids,
sizeof(pstate_ids));
if (npstates < 0) {
npstates = 0;
return;
}
if (OF_getencprop(node, "ibm,pstate-frequencies-mhz", pstate_freqs,
sizeof(pstate_freqs)) != npstates) {
npstates = 0;
return;
}
npstates /= sizeof(cell_t);
}
/* Make this a sysinit so it runs before the cpufreq driver attaches. */
SYSINIT(parse_pstates, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, parse_pstates, NULL);
#define PMCR_UPPERPS_MASK 0xff00000000000000UL
#define PMCR_UPPERPS_SHIFT 56
#define PMCR_LOWERPS_MASK 0x00ff000000000000UL
#define PMCR_LOWERPS_SHIFT 48
#define PMCR_VERSION_MASK 0x0000000f
#define PMCR_VERSION_1 1
struct pmcr_softc {
device_t dev;
};
static void pmcr_identify(driver_t *driver, device_t parent);
static int pmcr_probe(device_t dev);
static int pmcr_attach(device_t dev);
static int pmcr_settings(device_t dev, struct cf_setting *sets, int *count);
static int pmcr_set(device_t dev, const struct cf_setting *set);
static int pmcr_get(device_t dev, struct cf_setting *set);
static int pmcr_type(device_t dev, int *type);
static device_method_t pmcr_methods[] = {
/* Device interface */
DEVMETHOD(device_identify, pmcr_identify),
DEVMETHOD(device_probe, pmcr_probe),
DEVMETHOD(device_attach, pmcr_attach),
/* cpufreq interface */
DEVMETHOD(cpufreq_drv_set, pmcr_set),
DEVMETHOD(cpufreq_drv_get, pmcr_get),
DEVMETHOD(cpufreq_drv_type, pmcr_type),
DEVMETHOD(cpufreq_drv_settings, pmcr_settings),
{0, 0}
};
static driver_t pmcr_driver = {
"pmcr",
pmcr_methods,
sizeof(struct pmcr_softc)
};
static devclass_t pmcr_devclass;
DRIVER_MODULE(pmcr, cpu, pmcr_driver, pmcr_devclass, 0, 0);
static void
pmcr_identify(driver_t *driver, device_t parent)
{
/* Make sure we're not being doubly invoked. */
if (device_find_child(parent, "pmcr", -1) != NULL)
return;
/*
* We attach a child for every CPU since settings need to
* be performed on every CPU in the SMP case.
*/
if (BUS_ADD_CHILD(parent, 10, "pmcr", -1) == NULL)
device_printf(parent, "add pmcr child failed\n");
}
static int
pmcr_probe(device_t dev)
{
if (resource_disabled("pmcr", 0))
return (ENXIO);
if (npstates == 0)
return (ENXIO);
device_set_desc(dev, "Power Management Control Register");
return (0);
}
static int
pmcr_attach(device_t dev)
{
struct pmcr_softc *sc;
sc = device_get_softc(dev);
sc->dev = dev;
cpufreq_register(dev);
return (0);
}
static int
pmcr_settings(device_t dev, struct cf_setting *sets, int *count)
{
struct pmcr_softc *sc;
int i;
sc = device_get_softc(dev);
if (sets == NULL || count == NULL)
return (EINVAL);
if (*count < npstates)
return (E2BIG);
/* Return a list of valid settings for this driver. */
memset(sets, CPUFREQ_VAL_UNKNOWN, sizeof(*sets) * npstates);
for (i = 0; i < npstates; i++) {
sets[i].freq = pstate_freqs[i];
sets[i].spec[0] = pstate_ids[i];
sets[i].spec[1] = i;
sets[i].dev = dev;
}
*count = npstates;
return (0);
}
static int
pmcr_set(device_t dev, const struct cf_setting *set)
{
register_t pmcr;
if (set == NULL)
return (EINVAL);
if (set->spec[1] < 0 || set->spec[1] >= npstates)
return (EINVAL);
pmcr = ((long)set->spec[0] << PMCR_LOWERPS_SHIFT) & PMCR_LOWERPS_MASK;
pmcr |= ((long)set->spec[0] << PMCR_UPPERPS_SHIFT) & PMCR_UPPERPS_MASK;
pmcr |= PMCR_VERSION_1;
mtspr(SPR_PMCR, pmcr);
powerpc_sync(); isync();
return (0);
}
static int
pmcr_get(device_t dev, struct cf_setting *set)
{
struct pmcr_softc *sc;
register_t pmcr;
int i, pstate;
if (set == NULL)
return (EINVAL);
sc = device_get_softc(dev);
memset(set, CPUFREQ_VAL_UNKNOWN, sizeof(*set));
pmcr = mfspr(SPR_PMCR);
pstate = (pmcr & PMCR_LOWERPS_MASK) >> PMCR_LOWERPS_SHIFT;
for (i = 0; i < npstates && pstate_ids[i] != pstate; i++)
;
if (i == npstates)
return (EINVAL);
set->spec[0] = pstate;
set->spec[1] = i;
set->freq = pstate_freqs[i];
set->dev = dev;
return (0);
}
static int
pmcr_type(device_t dev, int *type)
{
if (type == NULL)
return (EINVAL);
*type = CPUFREQ_TYPE_ABSOLUTE;
return (0);
}