/*- * SPDX-License-Identifier: BSD-2-Clause * * Copyright (c) 2005 Nate Lawson * 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 ``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. */ /* * Throttle clock frequency by using the thermal control circuit. This * operates independently of SpeedStep and ACPI throttling and is supported * on Pentium 4 and later models (feature TM). * * Reference: Intel Developer's manual v.3 #245472-012 * * The original version of this driver was written by Ted Unangst for * OpenBSD and imported by Maxim Sobolev. It was rewritten by Nate Lawson * for use with the cpufreq framework. */ #include #include #include #include #include #include #include #include #include #include "cpufreq_if.h" #include #include #include "acpi_if.h" struct p4tcc_softc { device_t dev; int set_count; int lowest_val; int auto_mode; }; #define TCC_NUM_SETTINGS 8 #define TCC_ENABLE_ONDEMAND (1<<4) #define TCC_REG_OFFSET 1 #define TCC_SPEED_PERCENT(x) ((10000 * (x)) / TCC_NUM_SETTINGS) static int p4tcc_features(driver_t *driver, u_int *features); static void p4tcc_identify(driver_t *driver, device_t parent); static int p4tcc_probe(device_t dev); static int p4tcc_attach(device_t dev); static int p4tcc_detach(device_t dev); static int p4tcc_settings(device_t dev, struct cf_setting *sets, int *count); static int p4tcc_set(device_t dev, const struct cf_setting *set); static int p4tcc_get(device_t dev, struct cf_setting *set); static int p4tcc_type(device_t dev, int *type); static device_method_t p4tcc_methods[] = { /* Device interface */ DEVMETHOD(device_identify, p4tcc_identify), DEVMETHOD(device_probe, p4tcc_probe), DEVMETHOD(device_attach, p4tcc_attach), DEVMETHOD(device_detach, p4tcc_detach), /* cpufreq interface */ DEVMETHOD(cpufreq_drv_set, p4tcc_set), DEVMETHOD(cpufreq_drv_get, p4tcc_get), DEVMETHOD(cpufreq_drv_type, p4tcc_type), DEVMETHOD(cpufreq_drv_settings, p4tcc_settings), /* ACPI interface */ DEVMETHOD(acpi_get_features, p4tcc_features), {0, 0} }; static driver_t p4tcc_driver = { "p4tcc", p4tcc_methods, sizeof(struct p4tcc_softc), }; static devclass_t p4tcc_devclass; DRIVER_MODULE(p4tcc, cpu, p4tcc_driver, p4tcc_devclass, 0, 0); static int p4tcc_features(driver_t *driver, u_int *features) { /* Notify the ACPI CPU that we support direct access to MSRs */ *features = ACPI_CAP_THR_MSRS; return (0); } static void p4tcc_identify(driver_t *driver, device_t parent) { if ((cpu_feature & (CPUID_ACPI | CPUID_TM)) != (CPUID_ACPI | CPUID_TM)) return; /* Make sure we're not being doubly invoked. */ if (device_find_child(parent, "p4tcc", -1) != NULL) return; /* * We attach a p4tcc child for every CPU since settings need to * be performed on every CPU in the SMP case. See section 13.15.3 * of the IA32 Intel Architecture Software Developer's Manual, * Volume 3, for more info. */ if (BUS_ADD_CHILD(parent, 10, "p4tcc", device_get_unit(parent)) == NULL) device_printf(parent, "add p4tcc child failed\n"); } static int p4tcc_probe(device_t dev) { if (resource_disabled("p4tcc", 0)) return (ENXIO); device_set_desc(dev, "CPU Frequency Thermal Control"); return (0); } static int p4tcc_attach(device_t dev) { struct p4tcc_softc *sc; struct cf_setting set; sc = device_get_softc(dev); sc->dev = dev; sc->set_count = TCC_NUM_SETTINGS; /* * On boot, the TCC is usually in Automatic mode where reading the * current performance level is likely to produce bogus results. * We record that state here and don't trust the contents of the * status MSR until we've set it ourselves. */ sc->auto_mode = TRUE; /* * XXX: After a cursory glance at various Intel specification * XXX: updates it seems like these tests for errata is bogus. * XXX: As far as I can tell, the failure mode is benign, in * XXX: that cpus with no errata will have their bottom two * XXX: STPCLK# rates disabled, so rather than waste more time * XXX: hunting down intel docs, just document it and punt. /phk */ switch (cpu_id & 0xff) { case 0x22: case 0x24: case 0x25: case 0x27: case 0x29: /* * These CPU models hang when set to 12.5%. * See Errata O50, P44, and Z21. */ sc->set_count -= 1; break; case 0x07: /* errata N44 and P18 */ case 0x0a: case 0x12: case 0x13: case 0x62: /* Pentium D B1: errata AA21 */ case 0x64: /* Pentium D C1: errata AA21 */ case 0x65: /* Pentium D D0: errata AA21 */ /* * These CPU models hang when set to 12.5% or 25%. * See Errata N44, P18l and AA21. */ sc->set_count -= 2; break; } sc->lowest_val = TCC_NUM_SETTINGS - sc->set_count + 1; /* * Before we finish attach, switch to 100%. It's possible the BIOS * set us to a lower rate. The user can override this after boot. */ set.freq = 10000; p4tcc_set(dev, &set); cpufreq_register(dev); return (0); } static int p4tcc_detach(device_t dev) { struct cf_setting set; int error; error = cpufreq_unregister(dev); if (error) return (error); /* * Before we finish detach, switch to Automatic mode. */ set.freq = 10000; p4tcc_set(dev, &set); return(0); } static int p4tcc_settings(device_t dev, struct cf_setting *sets, int *count) { struct p4tcc_softc *sc; int i, val; sc = device_get_softc(dev); if (sets == NULL || count == NULL) return (EINVAL); if (*count < sc->set_count) return (E2BIG); /* Return a list of valid settings for this driver. */ memset(sets, CPUFREQ_VAL_UNKNOWN, sizeof(*sets) * sc->set_count); val = TCC_NUM_SETTINGS; for (i = 0; i < sc->set_count; i++, val--) { sets[i].freq = TCC_SPEED_PERCENT(val); sets[i].dev = dev; } *count = sc->set_count; return (0); } static int p4tcc_set(device_t dev, const struct cf_setting *set) { struct p4tcc_softc *sc; uint64_t mask, msr; int val; if (set == NULL) return (EINVAL); sc = device_get_softc(dev); /* * Validate requested state converts to a setting that is an integer * from [sc->lowest_val .. TCC_NUM_SETTINGS]. */ val = set->freq * TCC_NUM_SETTINGS / 10000; if (val * 10000 != set->freq * TCC_NUM_SETTINGS || val < sc->lowest_val || val > TCC_NUM_SETTINGS) return (EINVAL); /* * Read the current register and mask off the old setting and * On-Demand bit. If the new val is < 100%, set it and the On-Demand * bit, otherwise just return to Automatic mode. */ msr = rdmsr(MSR_THERM_CONTROL); mask = (TCC_NUM_SETTINGS - 1) << TCC_REG_OFFSET; msr &= ~(mask | TCC_ENABLE_ONDEMAND); if (val < TCC_NUM_SETTINGS) msr |= (val << TCC_REG_OFFSET) | TCC_ENABLE_ONDEMAND; wrmsr(MSR_THERM_CONTROL, msr); /* * Record whether we're now in Automatic or On-Demand mode. We have * to cache this since there is no reliable way to check if TCC is in * Automatic mode (i.e., at 100% or possibly 50%). Reading bit 4 of * the ACPI Thermal Monitor Control Register produces 0 no matter * what the current mode. */ if (msr & TCC_ENABLE_ONDEMAND) sc->auto_mode = FALSE; else sc->auto_mode = TRUE; return (0); } static int p4tcc_get(device_t dev, struct cf_setting *set) { struct p4tcc_softc *sc; uint64_t msr; int val; if (set == NULL) return (EINVAL); sc = device_get_softc(dev); /* * Read the current register and extract the current setting. If * in automatic mode, assume we're at TCC_NUM_SETTINGS (100%). * * XXX This is not completely reliable since at high temperatures * the CPU may be automatically throttling to 50% but it's the best * we can do. */ if (!sc->auto_mode) { msr = rdmsr(MSR_THERM_CONTROL); val = (msr >> TCC_REG_OFFSET) & (TCC_NUM_SETTINGS - 1); } else val = TCC_NUM_SETTINGS; memset(set, CPUFREQ_VAL_UNKNOWN, sizeof(*set)); set->freq = TCC_SPEED_PERCENT(val); set->dev = dev; return (0); } static int p4tcc_type(device_t dev, int *type) { if (type == NULL) return (EINVAL); *type = CPUFREQ_TYPE_RELATIVE; return (0); }