2 * Copyright (c) 2007, 2008 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.
28 * Device driver for Intel's On Die thermal sensor via MSR.
29 * First introduced in Intel's Core line of processors.
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
35 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/types.h>
39 #include <sys/module.h>
41 #include <sys/kernel.h>
42 #include <sys/sysctl.h>
43 #include <sys/proc.h> /* for curthread */
44 #include <sys/sched.h>
46 #include <machine/specialreg.h>
47 #include <machine/cpufunc.h>
48 #include <machine/cputypes.h>
49 #include <machine/md_var.h>
53 struct coretemp_softc {
56 struct sysctl_oid *sc_oid;
62 static void coretemp_identify(driver_t *driver, device_t parent);
63 static int coretemp_probe(device_t dev);
64 static int coretemp_attach(device_t dev);
65 static int coretemp_detach(device_t dev);
67 static int coretemp_get_temp(device_t dev);
68 static int coretemp_get_temp_sysctl(SYSCTL_HANDLER_ARGS);
70 static device_method_t coretemp_methods[] = {
71 /* Device interface */
72 DEVMETHOD(device_identify, coretemp_identify),
73 DEVMETHOD(device_probe, coretemp_probe),
74 DEVMETHOD(device_attach, coretemp_attach),
75 DEVMETHOD(device_detach, coretemp_detach),
80 static driver_t coretemp_driver = {
83 sizeof(struct coretemp_softc),
86 static devclass_t coretemp_devclass;
87 DRIVER_MODULE(coretemp, cpu, coretemp_driver, coretemp_devclass, NULL, NULL);
90 coretemp_identify(driver_t *driver, device_t parent)
95 /* Make sure we're not being doubly invoked. */
96 if (device_find_child(parent, "coretemp", -1) != NULL)
99 /* Check that CPUID 0x06 is supported and the vendor is Intel.*/
100 if (cpu_high < 6 || cpu_vendor_id != CPU_VENDOR_INTEL)
103 * CPUID 0x06 returns 1 if the processor has on-die thermal
104 * sensors. EBX[0:3] contains the number of sensors.
106 do_cpuid(0x06, regs);
107 if ((regs[0] & 0x1) != 1)
111 * We add a child for each CPU since settings must be performed
112 * on each CPU in the SMP case.
114 child = device_add_child(parent, "coretemp", -1);
116 device_printf(parent, "add coretemp child failed\n");
120 coretemp_probe(device_t dev)
122 if (resource_disabled("coretemp", 0))
125 device_set_desc(dev, "CPU On-Die Thermal Sensors");
127 return (BUS_PROBE_GENERIC);
131 coretemp_attach(device_t dev)
133 struct coretemp_softc *sc = device_get_softc(dev);
136 int cpu_model, cpu_stepping;
140 pdev = device_get_parent(dev);
141 cpu_model = CPUID_TO_MODEL(cpu_id);
142 cpu_stepping = cpu_id & CPUID_STEPPING;
145 * Some CPUs, namely the PIII, don't have thermal sensors, but
146 * report them when the CPUID check is performed in
147 * coretemp_identify(). This leads to a later GPF when the sensor
148 * is queried via a MSR, so we stop here.
154 * XXXrpaulo: I have this CPU model and when it returns from C3
155 * coretemp continues to function properly.
159 * Check for errata AE18.
160 * "Processor Digital Thermal Sensor (DTS) Readout stops
161 * updating upon returning from C3/C4 state."
163 * Adapted from the Linux coretemp driver.
165 if (cpu_model == 0xe && cpu_stepping < 0xc) {
166 msr = rdmsr(MSR_BIOS_SIGN);
169 device_printf(dev, "not supported (Intel errata "
170 "AE18), try updating your BIOS\n");
177 * Use 100C as the initial value.
181 if ((cpu_model == 0xf && cpu_stepping >= 2) || cpu_model == 0xe) {
183 * On some Core 2 CPUs, there's an undocumented MSR that
184 * can tell us if Tj(max) is 100 or 85.
186 * The if-clause for CPUs having the MSR_IA32_EXT_CONFIG was adapted
187 * from the Linux coretemp driver.
189 msr = rdmsr(MSR_IA32_EXT_CONFIG);
192 } else if (cpu_model == 0x17) {
193 switch (cpu_stepping) {
194 case 0x6: /* Mobile Core 2 Duo */
197 default: /* Unknown stepping */
202 * Attempt to get Tj(max) from MSR IA32_TEMPERATURE_TARGET.
204 * This method is described in Intel white paper "CPU
205 * Monitoring With DTS/PECI". (#322683)
207 ret = rdmsr_safe(MSR_IA32_TEMPERATURE_TARGET, &msr);
209 tjtarget = (msr >> 16) & 0xff;
212 * On earlier generation of processors, the value
213 * obtained from IA32_TEMPERATURE_TARGET register is
214 * an offset that needs to be summed with a model
215 * specific base. It is however not clear what
216 * these numbers are, with the publicly available
217 * documents from Intel.
219 * For now, we consider [70, 100]C range, as
220 * described in #322683, as "reasonable" and accept
221 * these values whenever the MSR is available for
222 * read, regardless the CPU model.
224 if (tjtarget >= 70 && tjtarget <= 100)
225 sc->sc_tjmax = tjtarget;
227 device_printf(dev, "Tj(target) value %d "
228 "does not seem right.\n", tjtarget);
230 device_printf(dev, "Can not get Tj(target) "
231 "from your CPU, using 100C.\n");
235 device_printf(dev, "Setting TjMax=%d\n", sc->sc_tjmax);
238 * Add the "temperature" MIB to dev.cpu.N.
240 sc->sc_oid = SYSCTL_ADD_PROC(device_get_sysctl_ctx(pdev),
241 SYSCTL_CHILDREN(device_get_sysctl_tree(pdev)),
242 OID_AUTO, "temperature",
243 CTLTYPE_INT | CTLFLAG_RD,
244 dev, 0, coretemp_get_temp_sysctl, "IK",
245 "Current temperature");
251 coretemp_detach(device_t dev)
253 struct coretemp_softc *sc = device_get_softc(dev);
255 sysctl_remove_oid(sc->sc_oid, 1, 0);
262 coretemp_get_temp(device_t dev)
266 int cpu = device_get_unit(dev);
267 struct coretemp_softc *sc = device_get_softc(dev);
270 thread_lock(curthread);
271 sched_bind(curthread, cpu);
272 thread_unlock(curthread);
275 * The digital temperature reading is located at bit 16
276 * of MSR_THERM_STATUS.
278 * There is a bit on that MSR that indicates whether the
279 * temperature is valid or not.
281 * The temperature is computed by subtracting the temperature
282 * reading by Tj(max).
284 msr = rdmsr(MSR_THERM_STATUS);
286 thread_lock(curthread);
287 sched_unbind(curthread);
288 thread_unlock(curthread);
291 * Check for Thermal Status and Thermal Status Log.
293 if ((msr & 0x3) == 0x3)
294 device_printf(dev, "PROCHOT asserted\n");
297 * Bit 31 contains "Reading valid"
299 if (((msr >> 31) & 0x1) == 1) {
301 * Starting on bit 16 and ending on bit 22.
303 temp = sc->sc_tjmax - ((msr >> 16) & 0x7f);
308 * Check for Critical Temperature Status and Critical
310 * It doesn't really matter if the current temperature is
311 * invalid because the "Critical Temperature Log" bit will
312 * tell us if the Critical Temperature has been reached in
313 * past. It's not directly related to the current temperature.
315 * If we reach a critical level, allow devctl(4) to catch this
316 * and shutdown the system.
318 if (((msr >> 4) & 0x3) == 0x3) {
319 device_printf(dev, "critical temperature detected, "
320 "suggest system shutdown\n");
321 snprintf(stemp, sizeof(stemp), "%d", temp);
322 devctl_notify("coretemp", "Thermal", stemp, "notify=0xcc");
329 coretemp_get_temp_sysctl(SYSCTL_HANDLER_ARGS)
331 device_t dev = (device_t) arg1;
334 temp = coretemp_get_temp(dev) * 10 + TZ_ZEROC;
336 return (sysctl_handle_int(oidp, &temp, 0, req));