svn commit: r335481 - in head/sys: kern powerpc/cpufreq sys
Justin Hibbits
jhibbits at FreeBSD.org
Thu Jun 21 14:26:44 UTC 2018
Author: jhibbits
Date: Thu Jun 21 14:26:43 2018
New Revision: 335481
URL: https://svnweb.freebsd.org/changeset/base/335481
Log:
Introduce PMCR-based cpufreq(4) driver, for IBM POWER8 and POWER9 systems
Summary: POWER8 and POWER9 use a single CPU register, per core, to change clock
speed. Everything else is handled by the on-chip controller. This change
necessitates a change to the cpufreq global kernel driver to bump supported
levels, as the device tree for these systems can have theoretically 256
different options. On my POWER9 Talos, the list consists of 100 items. At
16.67MHz intervals, that allows for a change of roughly 1.67GHz between lowest
and highest.
This has only been tested on the POWER9. However, since they're similar, this
should work on POWER8 as well.
Reviewed By: nwhitehorn
Differential Revision: https://reviews.freebsd.org/D15932
Added:
head/sys/powerpc/cpufreq/pmcr.c (contents, props changed)
Modified:
head/sys/kern/kern_cpu.c
head/sys/sys/cpu.h
Modified: head/sys/kern/kern_cpu.c
==============================================================================
--- head/sys/kern/kern_cpu.c Thu Jun 21 14:21:11 2018 (r335480)
+++ head/sys/kern/kern_cpu.c Thu Jun 21 14:26:43 2018 (r335481)
@@ -59,7 +59,7 @@ __FBSDID("$FreeBSD$");
* Number of levels we can handle. Levels are synthesized from settings
* so for M settings and N drivers, there may be M*N levels.
*/
-#define CF_MAX_LEVELS 64
+#define CF_MAX_LEVELS 256
struct cf_saved_freq {
struct cf_level level;
Added: head/sys/powerpc/cpufreq/pmcr.c
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ head/sys/powerpc/cpufreq/pmcr.c Thu Jun 21 14:26:43 2018 (r335481)
@@ -0,0 +1,248 @@
+/*-
+ * 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].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[0] < 0 || set->spec[0] > npstates)
+ return (EINVAL);
+
+ pmcr = ((long)pstate_ids[set->spec[0]] << PMCR_LOWERPS_SHIFT) &
+ PMCR_LOWERPS_MASK;
+ pmcr |= ((long)pstate_ids[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->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);
+}
+
Modified: head/sys/sys/cpu.h
==============================================================================
--- head/sys/sys/cpu.h Thu Jun 21 14:21:11 2018 (r335480)
+++ head/sys/sys/cpu.h Thu Jun 21 14:26:43 2018 (r335481)
@@ -87,7 +87,7 @@ struct cf_setting {
};
/* Maximum number of settings a given driver can have. */
-#define MAX_SETTINGS 24
+#define MAX_SETTINGS 256
/* A combination of settings is a level. */
struct cf_level {
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