xref: /freebsd/sys/dev/coretemp/coretemp.c (revision d0b2dbfa0ecf2bbc9709efc5e20baf8e4b44bbbf)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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 #include <sys/param.h>
36 #include <sys/bus.h>
37 #include <sys/conf.h>
38 #include <sys/kernel.h>
39 #include <sys/lock.h>
40 #include <sys/module.h>
41 #include <sys/mutex.h>
42 #include <sys/proc.h>	/* for curthread */
43 #include <sys/smp.h>
44 #include <sys/sysctl.h>
45 #include <sys/systm.h>
46 
47 #include <machine/specialreg.h>
48 #include <machine/cpufunc.h>
49 #include <machine/cputypes.h>
50 #include <machine/md_var.h>
51 
52 #define	TZ_ZEROC			2731
53 
54 #define	THERM_CRITICAL_STATUS_LOG       0x20
55 #define	THERM_CRITICAL_STATUS           0x10
56 #define	THERM_STATUS_LOG		0x02
57 #define	THERM_STATUS			0x01
58 #define	THERM_STATUS_TEMP_SHIFT		16
59 #define	THERM_STATUS_TEMP_MASK		0x7f
60 #define	THERM_STATUS_RES_SHIFT		27
61 #define	THERM_STATUS_RES_MASK		0x0f
62 #define	THERM_STATUS_VALID_SHIFT	31
63 #define	THERM_STATUS_VALID_MASK		0x01
64 
65 struct coretemp_softc {
66 	device_t	sc_dev;
67 	int		sc_tjmax;
68 	unsigned int	sc_throttle_log;
69 };
70 
71 /*
72  * Device methods.
73  */
74 static void	coretemp_identify(driver_t *driver, device_t parent);
75 static int	coretemp_probe(device_t dev);
76 static int	coretemp_attach(device_t dev);
77 static int	coretemp_detach(device_t dev);
78 
79 static uint64_t	coretemp_get_thermal_msr(int cpu);
80 static void	coretemp_clear_thermal_msr(int cpu);
81 static int	coretemp_get_val_sysctl(SYSCTL_HANDLER_ARGS);
82 static int	coretemp_throttle_log_sysctl(SYSCTL_HANDLER_ARGS);
83 
84 static device_method_t coretemp_methods[] = {
85 	/* Device interface */
86 	DEVMETHOD(device_identify,	coretemp_identify),
87 	DEVMETHOD(device_probe,		coretemp_probe),
88 	DEVMETHOD(device_attach,	coretemp_attach),
89 	DEVMETHOD(device_detach,	coretemp_detach),
90 
91 	DEVMETHOD_END
92 };
93 
94 static driver_t coretemp_driver = {
95 	"coretemp",
96 	coretemp_methods,
97 	sizeof(struct coretemp_softc),
98 };
99 
100 enum therm_info {
101 	CORETEMP_TEMP,
102 	CORETEMP_DELTA,
103 	CORETEMP_RESOLUTION,
104 	CORETEMP_TJMAX,
105 };
106 
107 DRIVER_MODULE(coretemp, cpu, coretemp_driver, NULL, NULL);
108 
109 static void
110 coretemp_identify(driver_t *driver, device_t parent)
111 {
112 	device_t child;
113 	u_int regs[4];
114 
115 	/* Make sure we're not being doubly invoked. */
116 	if (device_find_child(parent, "coretemp", -1) != NULL)
117 		return;
118 
119 	/* Check that CPUID 0x06 is supported and the vendor is Intel.*/
120 	if (cpu_high < 6 || cpu_vendor_id != CPU_VENDOR_INTEL)
121 		return;
122 	/*
123 	 * CPUID 0x06 returns 1 if the processor has on-die thermal
124 	 * sensors. EBX[0:3] contains the number of sensors.
125 	 */
126 	do_cpuid(0x06, regs);
127 	if ((regs[0] & 0x1) != 1)
128 		return;
129 
130 	/*
131 	 * We add a child for each CPU since settings must be performed
132 	 * on each CPU in the SMP case.
133 	 */
134 	child = device_add_child(parent, "coretemp", device_get_unit(parent));
135 	if (child == NULL)
136 		device_printf(parent, "add coretemp child failed\n");
137 }
138 
139 static int
140 coretemp_probe(device_t dev)
141 {
142 	if (resource_disabled("coretemp", 0))
143 		return (ENXIO);
144 
145 	device_set_desc(dev, "CPU On-Die Thermal Sensors");
146 
147 	if (!bootverbose && device_get_unit(dev) != 0)
148 		device_quiet(dev);
149 
150 	return (BUS_PROBE_GENERIC);
151 }
152 
153 static int
154 coretemp_attach(device_t dev)
155 {
156 	struct coretemp_softc *sc = device_get_softc(dev);
157 	device_t pdev;
158 	uint64_t msr;
159 	int cpu_model, cpu_stepping;
160 	int ret, tjtarget;
161 	struct sysctl_oid *oid;
162 	struct sysctl_ctx_list *ctx;
163 
164 	sc->sc_dev = dev;
165 	pdev = device_get_parent(dev);
166 	cpu_model = CPUID_TO_MODEL(cpu_id);
167 	cpu_stepping = CPUID_TO_STEPPING(cpu_id);
168 
169 	/*
170 	 * Some CPUs, namely the PIII, don't have thermal sensors, but
171 	 * report them when the CPUID check is performed in
172 	 * coretemp_identify(). This leads to a later GPF when the sensor
173 	 * is queried via a MSR, so we stop here.
174 	 */
175 	if (cpu_model < 0xe)
176 		return (ENXIO);
177 
178 #if 0 /*
179        * XXXrpaulo: I have this CPU model and when it returns from C3
180        * coretemp continues to function properly.
181        */
182 
183 	/*
184 	 * Check for errata AE18.
185 	 * "Processor Digital Thermal Sensor (DTS) Readout stops
186 	 *  updating upon returning from C3/C4 state."
187 	 *
188 	 * Adapted from the Linux coretemp driver.
189 	 */
190 	if (cpu_model == 0xe && cpu_stepping < 0xc) {
191 		msr = rdmsr(MSR_BIOS_SIGN);
192 		msr = msr >> 32;
193 		if (msr < 0x39) {
194 			device_printf(dev, "not supported (Intel errata "
195 			    "AE18), try updating your BIOS\n");
196 			return (ENXIO);
197 		}
198 	}
199 #endif
200 
201 	/*
202 	 * Use 100C as the initial value.
203 	 */
204 	sc->sc_tjmax = 100;
205 
206 	if ((cpu_model == 0xf && cpu_stepping >= 2) || cpu_model == 0xe) {
207 		/*
208 		 * On some Core 2 CPUs, there's an undocumented MSR that
209 		 * can tell us if Tj(max) is 100 or 85.
210 		 *
211 		 * The if-clause for CPUs having the MSR_IA32_EXT_CONFIG was adapted
212 		 * from the Linux coretemp driver.
213 		 */
214 		msr = rdmsr(MSR_IA32_EXT_CONFIG);
215 		if (msr & (1 << 30))
216 			sc->sc_tjmax = 85;
217 	} else if (cpu_model == 0x17) {
218 		switch (cpu_stepping) {
219 		case 0x6:	/* Mobile Core 2 Duo */
220 			sc->sc_tjmax = 105;
221 			break;
222 		default:	/* Unknown stepping */
223 			break;
224 		}
225 	} else if (cpu_model == 0x1c) {
226 		switch (cpu_stepping) {
227 		case 0xa:	/* 45nm Atom D400, N400 and D500 series */
228 			sc->sc_tjmax = 100;
229 			break;
230 		default:
231 			sc->sc_tjmax = 90;
232 			break;
233 		}
234 	} else {
235 		/*
236 		 * Attempt to get Tj(max) from MSR IA32_TEMPERATURE_TARGET.
237 		 *
238 		 * This method is described in Intel white paper "CPU
239 		 * Monitoring With DTS/PECI". (#322683)
240 		 */
241 		ret = rdmsr_safe(MSR_IA32_TEMPERATURE_TARGET, &msr);
242 		if (ret == 0) {
243 			tjtarget = (msr >> 16) & 0xff;
244 
245 			/*
246 			 * On earlier generation of processors, the value
247 			 * obtained from IA32_TEMPERATURE_TARGET register is
248 			 * an offset that needs to be summed with a model
249 			 * specific base.  It is however not clear what
250 			 * these numbers are, with the publicly available
251 			 * documents from Intel.
252 			 *
253 			 * For now, we consider [70, 110]C range, as
254 			 * described in #322683, as "reasonable" and accept
255 			 * these values whenever the MSR is available for
256 			 * read, regardless the CPU model.
257 			 */
258 			if (tjtarget >= 70 && tjtarget <= 110)
259 				sc->sc_tjmax = tjtarget;
260 			else
261 				device_printf(dev, "Tj(target) value %d "
262 				    "does not seem right.\n", tjtarget);
263 		} else
264 			device_printf(dev, "Can not get Tj(target) "
265 			    "from your CPU, using 100C.\n");
266 	}
267 
268 	if (bootverbose)
269 		device_printf(dev, "Setting TjMax=%d\n", sc->sc_tjmax);
270 
271 	ctx = device_get_sysctl_ctx(dev);
272 
273 	oid = SYSCTL_ADD_NODE(ctx,
274 	    SYSCTL_CHILDREN(device_get_sysctl_tree(pdev)), OID_AUTO,
275 	    "coretemp", CTLFLAG_RD | CTLFLAG_MPSAFE, NULL,
276 	    "Per-CPU thermal information");
277 
278 	/*
279 	 * Add the MIBs to dev.cpu.N and dev.cpu.N.coretemp.
280 	 */
281 	SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(device_get_sysctl_tree(pdev)),
282 	    OID_AUTO, "temperature", CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE,
283 	    dev, CORETEMP_TEMP, coretemp_get_val_sysctl, "IK",
284 	    "Current temperature");
285 	SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(oid), OID_AUTO, "delta",
286 	    CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE, dev, CORETEMP_DELTA,
287 	    coretemp_get_val_sysctl, "I",
288 	    "Delta between TCC activation and current temperature");
289 	SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(oid), OID_AUTO, "resolution",
290 	    CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE, dev, CORETEMP_RESOLUTION,
291 	    coretemp_get_val_sysctl, "I",
292 	    "Resolution of CPU thermal sensor");
293 	SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(oid), OID_AUTO, "tjmax",
294 	    CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE, dev, CORETEMP_TJMAX,
295 	    coretemp_get_val_sysctl, "IK",
296 	    "TCC activation temperature");
297 	SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(oid), OID_AUTO,
298 	    "throttle_log", CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, dev, 0,
299 	    coretemp_throttle_log_sysctl, "I",
300 	    "Set to 1 if the thermal sensor has tripped");
301 
302 	return (0);
303 }
304 
305 static int
306 coretemp_detach(device_t dev)
307 {
308 	return (0);
309 }
310 
311 struct coretemp_args {
312 	u_int		msr;
313 	uint64_t	val;
314 };
315 
316 /*
317  * The digital temperature reading is located at bit 16
318  * of MSR_THERM_STATUS.
319  *
320  * There is a bit on that MSR that indicates whether the
321  * temperature is valid or not.
322  *
323  * The temperature is computed by subtracting the temperature
324  * reading by Tj(max).
325  */
326 static uint64_t
327 coretemp_get_thermal_msr(int cpu)
328 {
329 	uint64_t res;
330 
331 	x86_msr_op(MSR_THERM_STATUS, MSR_OP_RENDEZVOUS_ONE | MSR_OP_READ |
332 	    MSR_OP_CPUID(cpu), 0, &res);
333 	return (res);
334 }
335 
336 static void
337 coretemp_clear_thermal_msr(int cpu)
338 {
339 	x86_msr_op(MSR_THERM_STATUS, MSR_OP_RENDEZVOUS_ONE | MSR_OP_WRITE |
340 	    MSR_OP_CPUID(cpu), 0, NULL);
341 }
342 
343 static int
344 coretemp_get_val_sysctl(SYSCTL_HANDLER_ARGS)
345 {
346 	device_t dev;
347 	uint64_t msr;
348 	int val, tmp;
349 	struct coretemp_softc *sc;
350 	enum therm_info type;
351 	char stemp[16];
352 
353 	dev = (device_t) arg1;
354 	msr = coretemp_get_thermal_msr(device_get_unit(dev));
355 	sc = device_get_softc(dev);
356 	type = arg2;
357 
358 	if (((msr >> THERM_STATUS_VALID_SHIFT) & THERM_STATUS_VALID_MASK) != 1) {
359 		val = -1;
360 	} else {
361 		switch (type) {
362 		case CORETEMP_TEMP:
363 			tmp = (msr >> THERM_STATUS_TEMP_SHIFT) &
364 			    THERM_STATUS_TEMP_MASK;
365 			val = (sc->sc_tjmax - tmp) * 10 + TZ_ZEROC;
366 			break;
367 		case CORETEMP_DELTA:
368 			val = (msr >> THERM_STATUS_TEMP_SHIFT) &
369 			    THERM_STATUS_TEMP_MASK;
370 			break;
371 		case CORETEMP_RESOLUTION:
372 			val = (msr >> THERM_STATUS_RES_SHIFT) &
373 			    THERM_STATUS_RES_MASK;
374 			break;
375 		case CORETEMP_TJMAX:
376 			val = sc->sc_tjmax * 10 + TZ_ZEROC;
377 			break;
378 		}
379 	}
380 
381 	if (msr & THERM_STATUS_LOG) {
382 		coretemp_clear_thermal_msr(device_get_unit(dev));
383 		sc->sc_throttle_log = 1;
384 
385 		/*
386 		 * Check for Critical Temperature Status and Critical
387 		 * Temperature Log.  It doesn't really matter if the
388 		 * current temperature is invalid because the "Critical
389 		 * Temperature Log" bit will tell us if the Critical
390 		 * Temperature has * been reached in past. It's not
391 		 * directly related to the current temperature.
392 		 *
393 		 * If we reach a critical level, allow devctl(4)
394 		 * to catch this and shutdown the system.
395 		 */
396 		if (msr & THERM_CRITICAL_STATUS) {
397 			tmp = (msr >> THERM_STATUS_TEMP_SHIFT) &
398 			    THERM_STATUS_TEMP_MASK;
399 			tmp = (sc->sc_tjmax - tmp) * 10 + TZ_ZEROC;
400 			device_printf(dev, "critical temperature detected, "
401 			    "suggest system shutdown\n");
402 			snprintf(stemp, sizeof(stemp), "%d", tmp);
403 			devctl_notify("coretemp", "Thermal", stemp,
404 			    "notify=0xcc");
405 		}
406 	}
407 
408 	return (sysctl_handle_int(oidp, &val, 0, req));
409 }
410 
411 static int
412 coretemp_throttle_log_sysctl(SYSCTL_HANDLER_ARGS)
413 {
414 	device_t dev;
415 	uint64_t msr;
416 	int error, val;
417 	struct coretemp_softc *sc;
418 
419 	dev = (device_t) arg1;
420 	msr = coretemp_get_thermal_msr(device_get_unit(dev));
421 	sc = device_get_softc(dev);
422 
423 	if (msr & THERM_STATUS_LOG) {
424 		coretemp_clear_thermal_msr(device_get_unit(dev));
425 		sc->sc_throttle_log = 1;
426 	}
427 
428 	val = sc->sc_throttle_log;
429 
430 	error = sysctl_handle_int(oidp, &val, 0, req);
431 
432 	if (error || !req->newptr)
433 		return (error);
434 	else if (val != 0)
435 		return (EINVAL);
436 
437 	coretemp_clear_thermal_msr(device_get_unit(dev));
438 	sc->sc_throttle_log = 0;
439 
440 	return (0);
441 }
442