xref: /freebsd/sys/dev/coretemp/coretemp.c (revision d9a42747950146bf03cda7f6e25d219253f8a57a)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2007, 2008 Rui Paulo <rpaulo@FreeBSD.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
19  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
20  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
21  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
22  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
24  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
25  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26  * POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 /*
30  * Device driver for Intel's On Die thermal sensor via MSR.
31  * First introduced in Intel's Core line of processors.
32  */
33 
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
36 
37 #include <sys/param.h>
38 #include <sys/bus.h>
39 #include <sys/conf.h>
40 #include <sys/kernel.h>
41 #include <sys/lock.h>
42 #include <sys/module.h>
43 #include <sys/mutex.h>
44 #include <sys/proc.h>	/* for curthread */
45 #include <sys/smp.h>
46 #include <sys/sysctl.h>
47 #include <sys/systm.h>
48 
49 #include <machine/specialreg.h>
50 #include <machine/cpufunc.h>
51 #include <machine/cputypes.h>
52 #include <machine/md_var.h>
53 
54 #define	TZ_ZEROC			2731
55 
56 #define	THERM_CRITICAL_STATUS_LOG       0x20
57 #define	THERM_CRITICAL_STATUS           0x10
58 #define	THERM_STATUS_LOG		0x02
59 #define	THERM_STATUS			0x01
60 #define	THERM_STATUS_TEMP_SHIFT		16
61 #define	THERM_STATUS_TEMP_MASK		0x7f
62 #define	THERM_STATUS_RES_SHIFT		27
63 #define	THERM_STATUS_RES_MASK		0x0f
64 #define	THERM_STATUS_VALID_SHIFT	31
65 #define	THERM_STATUS_VALID_MASK		0x01
66 
67 struct coretemp_softc {
68 	device_t	sc_dev;
69 	int		sc_tjmax;
70 	unsigned int	sc_throttle_log;
71 };
72 
73 /*
74  * Device methods.
75  */
76 static void	coretemp_identify(driver_t *driver, device_t parent);
77 static int	coretemp_probe(device_t dev);
78 static int	coretemp_attach(device_t dev);
79 static int	coretemp_detach(device_t dev);
80 
81 static uint64_t	coretemp_get_thermal_msr(int cpu);
82 static void	coretemp_clear_thermal_msr(int cpu);
83 static int	coretemp_get_val_sysctl(SYSCTL_HANDLER_ARGS);
84 static int	coretemp_throttle_log_sysctl(SYSCTL_HANDLER_ARGS);
85 
86 static device_method_t coretemp_methods[] = {
87 	/* Device interface */
88 	DEVMETHOD(device_identify,	coretemp_identify),
89 	DEVMETHOD(device_probe,		coretemp_probe),
90 	DEVMETHOD(device_attach,	coretemp_attach),
91 	DEVMETHOD(device_detach,	coretemp_detach),
92 
93 	DEVMETHOD_END
94 };
95 
96 static driver_t coretemp_driver = {
97 	"coretemp",
98 	coretemp_methods,
99 	sizeof(struct coretemp_softc),
100 };
101 
102 enum therm_info {
103 	CORETEMP_TEMP,
104 	CORETEMP_DELTA,
105 	CORETEMP_RESOLUTION,
106 	CORETEMP_TJMAX,
107 };
108 
109 DRIVER_MODULE(coretemp, cpu, coretemp_driver, NULL, NULL);
110 
111 static void
112 coretemp_identify(driver_t *driver, device_t parent)
113 {
114 	device_t child;
115 	u_int regs[4];
116 
117 	/* Make sure we're not being doubly invoked. */
118 	if (device_find_child(parent, "coretemp", -1) != NULL)
119 		return;
120 
121 	/* Check that CPUID 0x06 is supported and the vendor is Intel.*/
122 	if (cpu_high < 6 || cpu_vendor_id != CPU_VENDOR_INTEL)
123 		return;
124 	/*
125 	 * CPUID 0x06 returns 1 if the processor has on-die thermal
126 	 * sensors. EBX[0:3] contains the number of sensors.
127 	 */
128 	do_cpuid(0x06, regs);
129 	if ((regs[0] & 0x1) != 1)
130 		return;
131 
132 	/*
133 	 * We add a child for each CPU since settings must be performed
134 	 * on each CPU in the SMP case.
135 	 */
136 	child = device_add_child(parent, "coretemp", device_get_unit(parent));
137 	if (child == NULL)
138 		device_printf(parent, "add coretemp child failed\n");
139 }
140 
141 static int
142 coretemp_probe(device_t dev)
143 {
144 	if (resource_disabled("coretemp", 0))
145 		return (ENXIO);
146 
147 	device_set_desc(dev, "CPU On-Die Thermal Sensors");
148 
149 	if (!bootverbose && device_get_unit(dev) != 0)
150 		device_quiet(dev);
151 
152 	return (BUS_PROBE_GENERIC);
153 }
154 
155 static int
156 coretemp_attach(device_t dev)
157 {
158 	struct coretemp_softc *sc = device_get_softc(dev);
159 	device_t pdev;
160 	uint64_t msr;
161 	int cpu_model, cpu_stepping;
162 	int ret, tjtarget;
163 	struct sysctl_oid *oid;
164 	struct sysctl_ctx_list *ctx;
165 
166 	sc->sc_dev = dev;
167 	pdev = device_get_parent(dev);
168 	cpu_model = CPUID_TO_MODEL(cpu_id);
169 	cpu_stepping = CPUID_TO_STEPPING(cpu_id);
170 
171 	/*
172 	 * Some CPUs, namely the PIII, don't have thermal sensors, but
173 	 * report them when the CPUID check is performed in
174 	 * coretemp_identify(). This leads to a later GPF when the sensor
175 	 * is queried via a MSR, so we stop here.
176 	 */
177 	if (cpu_model < 0xe)
178 		return (ENXIO);
179 
180 #if 0 /*
181        * XXXrpaulo: I have this CPU model and when it returns from C3
182        * coretemp continues to function properly.
183        */
184 
185 	/*
186 	 * Check for errata AE18.
187 	 * "Processor Digital Thermal Sensor (DTS) Readout stops
188 	 *  updating upon returning from C3/C4 state."
189 	 *
190 	 * Adapted from the Linux coretemp driver.
191 	 */
192 	if (cpu_model == 0xe && cpu_stepping < 0xc) {
193 		msr = rdmsr(MSR_BIOS_SIGN);
194 		msr = msr >> 32;
195 		if (msr < 0x39) {
196 			device_printf(dev, "not supported (Intel errata "
197 			    "AE18), try updating your BIOS\n");
198 			return (ENXIO);
199 		}
200 	}
201 #endif
202 
203 	/*
204 	 * Use 100C as the initial value.
205 	 */
206 	sc->sc_tjmax = 100;
207 
208 	if ((cpu_model == 0xf && cpu_stepping >= 2) || cpu_model == 0xe) {
209 		/*
210 		 * On some Core 2 CPUs, there's an undocumented MSR that
211 		 * can tell us if Tj(max) is 100 or 85.
212 		 *
213 		 * The if-clause for CPUs having the MSR_IA32_EXT_CONFIG was adapted
214 		 * from the Linux coretemp driver.
215 		 */
216 		msr = rdmsr(MSR_IA32_EXT_CONFIG);
217 		if (msr & (1 << 30))
218 			sc->sc_tjmax = 85;
219 	} else if (cpu_model == 0x17) {
220 		switch (cpu_stepping) {
221 		case 0x6:	/* Mobile Core 2 Duo */
222 			sc->sc_tjmax = 105;
223 			break;
224 		default:	/* Unknown stepping */
225 			break;
226 		}
227 	} else if (cpu_model == 0x1c) {
228 		switch (cpu_stepping) {
229 		case 0xa:	/* 45nm Atom D400, N400 and D500 series */
230 			sc->sc_tjmax = 100;
231 			break;
232 		default:
233 			sc->sc_tjmax = 90;
234 			break;
235 		}
236 	} else {
237 		/*
238 		 * Attempt to get Tj(max) from MSR IA32_TEMPERATURE_TARGET.
239 		 *
240 		 * This method is described in Intel white paper "CPU
241 		 * Monitoring With DTS/PECI". (#322683)
242 		 */
243 		ret = rdmsr_safe(MSR_IA32_TEMPERATURE_TARGET, &msr);
244 		if (ret == 0) {
245 			tjtarget = (msr >> 16) & 0xff;
246 
247 			/*
248 			 * On earlier generation of processors, the value
249 			 * obtained from IA32_TEMPERATURE_TARGET register is
250 			 * an offset that needs to be summed with a model
251 			 * specific base.  It is however not clear what
252 			 * these numbers are, with the publicly available
253 			 * documents from Intel.
254 			 *
255 			 * For now, we consider [70, 110]C range, as
256 			 * described in #322683, as "reasonable" and accept
257 			 * these values whenever the MSR is available for
258 			 * read, regardless the CPU model.
259 			 */
260 			if (tjtarget >= 70 && tjtarget <= 110)
261 				sc->sc_tjmax = tjtarget;
262 			else
263 				device_printf(dev, "Tj(target) value %d "
264 				    "does not seem right.\n", tjtarget);
265 		} else
266 			device_printf(dev, "Can not get Tj(target) "
267 			    "from your CPU, using 100C.\n");
268 	}
269 
270 	if (bootverbose)
271 		device_printf(dev, "Setting TjMax=%d\n", sc->sc_tjmax);
272 
273 	ctx = device_get_sysctl_ctx(dev);
274 
275 	oid = SYSCTL_ADD_NODE(ctx,
276 	    SYSCTL_CHILDREN(device_get_sysctl_tree(pdev)), OID_AUTO,
277 	    "coretemp", CTLFLAG_RD | CTLFLAG_MPSAFE, NULL,
278 	    "Per-CPU thermal information");
279 
280 	/*
281 	 * Add the MIBs to dev.cpu.N and dev.cpu.N.coretemp.
282 	 */
283 	SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(device_get_sysctl_tree(pdev)),
284 	    OID_AUTO, "temperature", CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE,
285 	    dev, CORETEMP_TEMP, coretemp_get_val_sysctl, "IK",
286 	    "Current temperature");
287 	SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(oid), OID_AUTO, "delta",
288 	    CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE, dev, CORETEMP_DELTA,
289 	    coretemp_get_val_sysctl, "I",
290 	    "Delta between TCC activation and current temperature");
291 	SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(oid), OID_AUTO, "resolution",
292 	    CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE, dev, CORETEMP_RESOLUTION,
293 	    coretemp_get_val_sysctl, "I",
294 	    "Resolution of CPU thermal sensor");
295 	SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(oid), OID_AUTO, "tjmax",
296 	    CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE, dev, CORETEMP_TJMAX,
297 	    coretemp_get_val_sysctl, "IK",
298 	    "TCC activation temperature");
299 	SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(oid), OID_AUTO,
300 	    "throttle_log", CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, dev, 0,
301 	    coretemp_throttle_log_sysctl, "I",
302 	    "Set to 1 if the thermal sensor has tripped");
303 
304 	return (0);
305 }
306 
307 static int
308 coretemp_detach(device_t dev)
309 {
310 	return (0);
311 }
312 
313 struct coretemp_args {
314 	u_int		msr;
315 	uint64_t	val;
316 };
317 
318 /*
319  * The digital temperature reading is located at bit 16
320  * of MSR_THERM_STATUS.
321  *
322  * There is a bit on that MSR that indicates whether the
323  * temperature is valid or not.
324  *
325  * The temperature is computed by subtracting the temperature
326  * reading by Tj(max).
327  */
328 static uint64_t
329 coretemp_get_thermal_msr(int cpu)
330 {
331 	uint64_t res;
332 
333 	x86_msr_op(MSR_THERM_STATUS, MSR_OP_RENDEZVOUS_ONE | MSR_OP_READ |
334 	    MSR_OP_CPUID(cpu), 0, &res);
335 	return (res);
336 }
337 
338 static void
339 coretemp_clear_thermal_msr(int cpu)
340 {
341 	x86_msr_op(MSR_THERM_STATUS, MSR_OP_RENDEZVOUS_ONE | MSR_OP_WRITE |
342 	    MSR_OP_CPUID(cpu), 0, NULL);
343 }
344 
345 static int
346 coretemp_get_val_sysctl(SYSCTL_HANDLER_ARGS)
347 {
348 	device_t dev;
349 	uint64_t msr;
350 	int val, tmp;
351 	struct coretemp_softc *sc;
352 	enum therm_info type;
353 	char stemp[16];
354 
355 	dev = (device_t) arg1;
356 	msr = coretemp_get_thermal_msr(device_get_unit(dev));
357 	sc = device_get_softc(dev);
358 	type = arg2;
359 
360 	if (((msr >> THERM_STATUS_VALID_SHIFT) & THERM_STATUS_VALID_MASK) != 1) {
361 		val = -1;
362 	} else {
363 		switch (type) {
364 		case CORETEMP_TEMP:
365 			tmp = (msr >> THERM_STATUS_TEMP_SHIFT) &
366 			    THERM_STATUS_TEMP_MASK;
367 			val = (sc->sc_tjmax - tmp) * 10 + TZ_ZEROC;
368 			break;
369 		case CORETEMP_DELTA:
370 			val = (msr >> THERM_STATUS_TEMP_SHIFT) &
371 			    THERM_STATUS_TEMP_MASK;
372 			break;
373 		case CORETEMP_RESOLUTION:
374 			val = (msr >> THERM_STATUS_RES_SHIFT) &
375 			    THERM_STATUS_RES_MASK;
376 			break;
377 		case CORETEMP_TJMAX:
378 			val = sc->sc_tjmax * 10 + TZ_ZEROC;
379 			break;
380 		}
381 	}
382 
383 	if (msr & THERM_STATUS_LOG) {
384 		coretemp_clear_thermal_msr(device_get_unit(dev));
385 		sc->sc_throttle_log = 1;
386 
387 		/*
388 		 * Check for Critical Temperature Status and Critical
389 		 * Temperature Log.  It doesn't really matter if the
390 		 * current temperature is invalid because the "Critical
391 		 * Temperature Log" bit will tell us if the Critical
392 		 * Temperature has * been reached in past. It's not
393 		 * directly related to the current temperature.
394 		 *
395 		 * If we reach a critical level, allow devctl(4)
396 		 * to catch this and shutdown the system.
397 		 */
398 		if (msr & THERM_CRITICAL_STATUS) {
399 			tmp = (msr >> THERM_STATUS_TEMP_SHIFT) &
400 			    THERM_STATUS_TEMP_MASK;
401 			tmp = (sc->sc_tjmax - tmp) * 10 + TZ_ZEROC;
402 			device_printf(dev, "critical temperature detected, "
403 			    "suggest system shutdown\n");
404 			snprintf(stemp, sizeof(stemp), "%d", tmp);
405 			devctl_notify("coretemp", "Thermal", stemp,
406 			    "notify=0xcc");
407 		}
408 	}
409 
410 	return (sysctl_handle_int(oidp, &val, 0, req));
411 }
412 
413 static int
414 coretemp_throttle_log_sysctl(SYSCTL_HANDLER_ARGS)
415 {
416 	device_t dev;
417 	uint64_t msr;
418 	int error, val;
419 	struct coretemp_softc *sc;
420 
421 	dev = (device_t) arg1;
422 	msr = coretemp_get_thermal_msr(device_get_unit(dev));
423 	sc = device_get_softc(dev);
424 
425 	if (msr & THERM_STATUS_LOG) {
426 		coretemp_clear_thermal_msr(device_get_unit(dev));
427 		sc->sc_throttle_log = 1;
428 	}
429 
430 	val = sc->sc_throttle_log;
431 
432 	error = sysctl_handle_int(oidp, &val, 0, req);
433 
434 	if (error || !req->newptr)
435 		return (error);
436 	else if (val != 0)
437 		return (EINVAL);
438 
439 	coretemp_clear_thermal_msr(device_get_unit(dev));
440 	sc->sc_throttle_log = 0;
441 
442 	return (0);
443 }
444