2 * Copyright (c) 2007 Rui Paulo <rpaulo@FreeBSD.org>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
16 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
17 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
18 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
19 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
20 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
22 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
23 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
24 * POSSIBILITY OF SUCH DAMAGE.
26 * $FreeBSD: src/sys/dev/coretemp/coretemp.c,v 1.2 2007/08/23 10:53:03 des Exp $
27 * $DragonFly: src/sys/dev/powermng/coretemp/coretemp.c,v 1.1 2007/10/02 13:16:42 hasso Exp $
31 * Device driver for Intel's On Die thermal sensor via MSR.
32 * First introduced in Intel's Core line of processors.
35 #include <sys/cdefs.h>
36 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/types.h>
40 #include <sys/module.h>
42 #include <sys/kernel.h>
43 #include <sys/sensors.h>
44 #include <sys/spinlock.h>
45 #include <sys/spinlock2.h>
46 #include <sys/proc.h> /* for curthread */
47 #include <sys/sched.h>
49 #include <machine/specialreg.h>
50 #include <machine/cpufunc.h>
51 #include <machine/md_var.h>
53 static struct spinlock coretemp_lock;
55 struct coretemp_softc {
56 struct ksensordev sc_sensordev;
57 struct ksensor sc_sensor;
65 static void coretemp_identify(driver_t *driver, device_t parent);
66 static int coretemp_probe(device_t dev);
67 static int coretemp_attach(device_t dev);
68 static int coretemp_detach(device_t dev);
70 static int coretemp_get_temp(device_t dev);
71 static void coretemp_refresh(void *arg);
73 static device_method_t coretemp_methods[] = {
74 /* Device interface */
75 DEVMETHOD(device_identify, coretemp_identify),
76 DEVMETHOD(device_probe, coretemp_probe),
77 DEVMETHOD(device_attach, coretemp_attach),
78 DEVMETHOD(device_detach, coretemp_detach),
83 static driver_t coretemp_driver = {
86 sizeof(struct coretemp_softc),
89 static devclass_t coretemp_devclass;
90 DRIVER_MODULE(coretemp, cpu, coretemp_driver, coretemp_devclass, NULL, NULL);
93 coretemp_identify(driver_t *driver, device_t parent)
98 /* Make sure we're not being doubly invoked. */
99 if (device_find_child(parent, "coretemp", -1) != NULL)
102 /* Check that CPUID is supported and the vendor is Intel.*/
103 if (cpu_high == 0 || strcmp(cpu_vendor, "GenuineIntel"))
106 * CPUID 0x06 returns 1 if the processor has on-die thermal
107 * sensors. EBX[0:3] contains the number of sensors.
109 do_cpuid(0x06, regs);
110 if ((regs[0] & 0x1) != 1)
114 * We add a child for each CPU since settings must be performed
115 * on each CPU in the SMP case.
117 child = device_add_child(parent, "coretemp", -1);
119 device_printf(parent, "add coretemp child failed\n");
123 coretemp_probe(device_t dev)
125 if (resource_disabled("coretemp", 0))
128 device_set_desc(dev, "CPU On-Die Thermal Sensors");
130 return (BUS_PROBE_GENERIC);
134 coretemp_attach(device_t dev)
136 struct coretemp_softc *sc = device_get_softc(dev);
143 pdev = device_get_parent(dev);
144 cpu_model = (cpu_id >> 4) & 15;
146 cpu_model += ((cpu_id >> 16) & 0xf) << 4;
147 cpu_mask = cpu_id & 15;
150 * Check for errata AE18.
151 * "Processor Digital Thermal Sensor (DTS) Readout stops
152 * updating upon returning from C3/C4 state."
154 * Adapted from the Linux coretemp driver.
156 if (cpu_model == 0xe && cpu_mask < 0xc) {
157 msr = rdmsr(MSR_BIOS_SIGN);
160 device_printf(dev, "not supported (Intel errata "
161 "AE18), try updating your BIOS\n");
166 * On some Core 2 CPUs, there's an undocumented MSR that
167 * can tell us if Tj(max) is 100 or 85.
169 * The if-clause for CPUs having the MSR_IA32_EXT_CONFIG was adapted
170 * from the Linux coretemp driver.
173 if ((cpu_model == 0xf && cpu_mask >= 2) || cpu_model == 0xe) {
174 msr = rdmsr(MSR_IA32_EXT_CONFIG);
180 * Add hw.sensors.cpuN.temp0 MIB.
182 strlcpy(sc->sc_sensordev.xname, device_get_nameunit(pdev),
183 sizeof(sc->sc_sensordev.xname));
184 sc->sc_sensor.type = SENSOR_TEMP;
185 sensor_attach(&sc->sc_sensordev, &sc->sc_sensor);
186 if (sensor_task_register(sc, coretemp_refresh, 2)) {
187 device_printf(dev, "unable to register update task\n");
190 sensordev_install(&sc->sc_sensordev);
191 spin_init(&coretemp_lock);
197 coretemp_detach(device_t dev)
199 struct coretemp_softc *sc = device_get_softc(dev);
201 spin_lock_wr(&coretemp_lock);
202 sensordev_deinstall(&sc->sc_sensordev);
203 sensor_task_unregister(sc);
204 spin_unlock_wr(&coretemp_lock);
205 spin_uninit(&coretemp_lock);
212 coretemp_get_temp(device_t dev)
216 int cpu = device_get_unit(dev);
217 struct coretemp_softc *sc = device_get_softc(dev);
221 * Bind to specific CPU to read the correct temperature.
222 * If not all CPUs are initialised, then only read from
223 * cpu0, returning -1 on all other CPUs.
226 spin_lock_rd(&coretemp_lock);
227 msr = rdmsr(MSR_THERM_STATUS);
228 spin_unlock_rd(&coretemp_lock);
232 msr = rdmsr(MSR_THERM_STATUS);
235 * Check for Thermal Status and Thermal Status Log.
237 if ((msr & 0x3) == 0x3)
238 device_printf(dev, "PROCHOT asserted\n");
241 * Bit 31 contains "Reading valid"
243 if (((msr >> 31) & 0x1) == 1) {
245 * Starting on bit 16 and ending on bit 22.
247 temp = sc->sc_tjmax - ((msr >> 16) & 0x7f);
252 * Check for Critical Temperature Status and Critical
254 * It doesn't really matter if the current temperature is
255 * invalid because the "Critical Temperature Log" bit will
256 * tell us if the Critical Temperature has been reached in
257 * past. It's not directly related to the current temperature.
259 * If we reach a critical level, allow devctl(4) to catch this
260 * and shutdown the system.
262 if (((msr >> 4) & 0x3) == 0x3) {
263 device_printf(dev, "critical temperature detected, "
264 "suggest system shutdown\n");
265 ksnprintf(stemp, sizeof(stemp), "%d", temp);
267 devctl_notify("coretemp", "Thermal", stemp, "notify=0xcc");
275 coretemp_refresh(void *arg)
277 struct coretemp_softc *sc = arg;
278 device_t dev = sc->sc_dev;
279 struct ksensor *s = &sc->sc_sensor;
282 temp = coretemp_get_temp(dev);
285 s->flags |= SENSOR_FINVALID;
288 s->flags &= ~SENSOR_FINVALID;
289 s->value = temp * 1000000 + 273150000;