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: releng/12.0/sys/dev/coretemp/coretemp.c 335186 2018-06-15 02:28:36Z mmacy $");
36
37 #include <sys/param.h>
38 #include <sys/bus.h>
39 #include <sys/systm.h>
40 #include <sys/types.h>
41 #include <sys/module.h>
42 #include <sys/conf.h>
43 #include <sys/kernel.h>
44 #include <sys/sysctl.h>
45 #include <sys/proc.h> /* for curthread */
46 #include <sys/sched.h>
47
48 #include <machine/specialreg.h>
49 #include <machine/cpufunc.h>
50 #include <machine/cputypes.h>
51 #include <machine/md_var.h>
52
53 #define TZ_ZEROC 2731
54
55 #define THERM_STATUS_LOG 0x02
56 #define THERM_STATUS 0x01
57 #define THERM_STATUS_TEMP_SHIFT 16
58 #define THERM_STATUS_TEMP_MASK 0x7f
59 #define THERM_STATUS_RES_SHIFT 27
60 #define THERM_STATUS_RES_MASK 0x0f
61 #define THERM_STATUS_VALID_SHIFT 31
62 #define THERM_STATUS_VALID_MASK 0x01
63
64 struct coretemp_softc {
65 device_t sc_dev;
66 int sc_tjmax;
67 unsigned int sc_throttle_log;
68 };
69
70 /*
71 * Device methods.
72 */
73 static void coretemp_identify(driver_t *driver, device_t parent);
74 static int coretemp_probe(device_t dev);
75 static int coretemp_attach(device_t dev);
76 static int coretemp_detach(device_t dev);
77
78 static uint64_t coretemp_get_thermal_msr(int cpu);
79 static void coretemp_clear_thermal_msr(int cpu);
80 static int coretemp_get_val_sysctl(SYSCTL_HANDLER_ARGS);
81 static int coretemp_throttle_log_sysctl(SYSCTL_HANDLER_ARGS);
82
83 static device_method_t coretemp_methods[] = {
84 /* Device interface */
85 DEVMETHOD(device_identify, coretemp_identify),
86 DEVMETHOD(device_probe, coretemp_probe),
87 DEVMETHOD(device_attach, coretemp_attach),
88 DEVMETHOD(device_detach, coretemp_detach),
89
90 DEVMETHOD_END
91 };
92
93 static driver_t coretemp_driver = {
94 "coretemp",
95 coretemp_methods,
96 sizeof(struct coretemp_softc),
97 };
98
99 enum therm_info {
100 CORETEMP_TEMP,
101 CORETEMP_DELTA,
102 CORETEMP_RESOLUTION,
103 CORETEMP_TJMAX,
104 };
105
106 static devclass_t coretemp_devclass;
107 DRIVER_MODULE(coretemp, cpu, coretemp_driver, coretemp_devclass, NULL,
108 NULL);
109
110 static void
111 coretemp_identify(driver_t *driver, device_t parent)
112 {
113 device_t child;
114 u_int regs[4];
115
116 /* Make sure we're not being doubly invoked. */
117 if (device_find_child(parent, "coretemp", -1) != NULL)
118 return;
119
120 /* Check that CPUID 0x06 is supported and the vendor is Intel.*/
121 if (cpu_high < 6 || cpu_vendor_id != CPU_VENDOR_INTEL)
122 return;
123 /*
124 * CPUID 0x06 returns 1 if the processor has on-die thermal
125 * sensors. EBX[0:3] contains the number of sensors.
126 */
127 do_cpuid(0x06, regs);
128 if ((regs[0] & 0x1) != 1)
129 return;
130
131 /*
132 * We add a child for each CPU since settings must be performed
133 * on each CPU in the SMP case.
134 */
135 child = device_add_child(parent, "coretemp", -1);
136 if (child == NULL)
137 device_printf(parent, "add coretemp child failed\n");
138 }
139
140 static int
141 coretemp_probe(device_t dev)
142 {
143 if (resource_disabled("coretemp", 0))
144 return (ENXIO);
145
146 device_set_desc(dev, "CPU On-Die Thermal Sensors");
147
148 if (!bootverbose && device_get_unit(dev) != 0)
149 device_quiet(dev);
150
151 return (BUS_PROBE_GENERIC);
152 }
153
154 static int
155 coretemp_attach(device_t dev)
156 {
157 struct coretemp_softc *sc = device_get_softc(dev);
158 device_t pdev;
159 uint64_t msr;
160 int cpu_model, cpu_stepping;
161 int ret, tjtarget;
162 struct sysctl_oid *oid;
163 struct sysctl_ctx_list *ctx;
164
165 sc->sc_dev = dev;
166 pdev = device_get_parent(dev);
167 cpu_model = CPUID_TO_MODEL(cpu_id);
168 cpu_stepping = cpu_id & CPUID_STEPPING;
169
170 /*
171 * Some CPUs, namely the PIII, don't have thermal sensors, but
172 * report them when the CPUID check is performed in
173 * coretemp_identify(). This leads to a later GPF when the sensor
174 * is queried via a MSR, so we stop here.
175 */
176 if (cpu_model < 0xe)
177 return (ENXIO);
178
179 #if 0 /*
180 * XXXrpaulo: I have this CPU model and when it returns from C3
181 * coretemp continues to function properly.
182 */
183
184 /*
185 * Check for errata AE18.
186 * "Processor Digital Thermal Sensor (DTS) Readout stops
187 * updating upon returning from C3/C4 state."
188 *
189 * Adapted from the Linux coretemp driver.
190 */
191 if (cpu_model == 0xe && cpu_stepping < 0xc) {
192 msr = rdmsr(MSR_BIOS_SIGN);
193 msr = msr >> 32;
194 if (msr < 0x39) {
195 device_printf(dev, "not supported (Intel errata "
196 "AE18), try updating your BIOS\n");
197 return (ENXIO);
198 }
199 }
200 #endif
201
202 /*
203 * Use 100C as the initial value.
204 */
205 sc->sc_tjmax = 100;
206
207 if ((cpu_model == 0xf && cpu_stepping >= 2) || cpu_model == 0xe) {
208 /*
209 * On some Core 2 CPUs, there's an undocumented MSR that
210 * can tell us if Tj(max) is 100 or 85.
211 *
212 * The if-clause for CPUs having the MSR_IA32_EXT_CONFIG was adapted
213 * from the Linux coretemp driver.
214 */
215 msr = rdmsr(MSR_IA32_EXT_CONFIG);
216 if (msr & (1 << 30))
217 sc->sc_tjmax = 85;
218 } else if (cpu_model == 0x17) {
219 switch (cpu_stepping) {
220 case 0x6: /* Mobile Core 2 Duo */
221 sc->sc_tjmax = 105;
222 break;
223 default: /* Unknown stepping */
224 break;
225 }
226 } else if (cpu_model == 0x1c) {
227 switch (cpu_stepping) {
228 case 0xa: /* 45nm Atom D400, N400 and D500 series */
229 sc->sc_tjmax = 100;
230 break;
231 default:
232 sc->sc_tjmax = 90;
233 break;
234 }
235 } else {
236 /*
237 * Attempt to get Tj(max) from MSR IA32_TEMPERATURE_TARGET.
238 *
239 * This method is described in Intel white paper "CPU
240 * Monitoring With DTS/PECI". (#322683)
241 */
242 ret = rdmsr_safe(MSR_IA32_TEMPERATURE_TARGET, &msr);
243 if (ret == 0) {
244 tjtarget = (msr >> 16) & 0xff;
245
246 /*
247 * On earlier generation of processors, the value
248 * obtained from IA32_TEMPERATURE_TARGET register is
249 * an offset that needs to be summed with a model
250 * specific base. It is however not clear what
251 * these numbers are, with the publicly available
252 * documents from Intel.
253 *
254 * For now, we consider [70, 110]C range, as
255 * described in #322683, as "reasonable" and accept
256 * these values whenever the MSR is available for
257 * read, regardless the CPU model.
258 */
259 if (tjtarget >= 70 && tjtarget <= 110)
260 sc->sc_tjmax = tjtarget;
261 else
262 device_printf(dev, "Tj(target) value %d "
263 "does not seem right.\n", tjtarget);
264 } else
265 device_printf(dev, "Can not get Tj(target) "
266 "from your CPU, using 100C.\n");
267 }
268
269 if (bootverbose)
270 device_printf(dev, "Setting TjMax=%d\n", sc->sc_tjmax);
271
272 ctx = device_get_sysctl_ctx(dev);
273
274 oid = SYSCTL_ADD_NODE(ctx,
275 SYSCTL_CHILDREN(device_get_sysctl_tree(pdev)), OID_AUTO,
276 "coretemp", CTLFLAG_RD, NULL, "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 static uint64_t
312 coretemp_get_thermal_msr(int cpu)
313 {
314 uint64_t msr;
315
316 thread_lock(curthread);
317 sched_bind(curthread, cpu);
318 thread_unlock(curthread);
319
320 /*
321 * The digital temperature reading is located at bit 16
322 * of MSR_THERM_STATUS.
323 *
324 * There is a bit on that MSR that indicates whether the
325 * temperature is valid or not.
326 *
327 * The temperature is computed by subtracting the temperature
328 * reading by Tj(max).
329 */
330 msr = rdmsr(MSR_THERM_STATUS);
331
332 thread_lock(curthread);
333 sched_unbind(curthread);
334 thread_unlock(curthread);
335
336 return (msr);
337 }
338
339 static void
340 coretemp_clear_thermal_msr(int cpu)
341 {
342 thread_lock(curthread);
343 sched_bind(curthread, cpu);
344 thread_unlock(curthread);
345
346 wrmsr(MSR_THERM_STATUS, 0);
347
348 thread_lock(curthread);
349 sched_unbind(curthread);
350 thread_unlock(curthread);
351 }
352
353 static int
354 coretemp_get_val_sysctl(SYSCTL_HANDLER_ARGS)
355 {
356 device_t dev;
357 uint64_t msr;
358 int val, tmp;
359 struct coretemp_softc *sc;
360 enum therm_info type;
361 char stemp[16];
362
363 dev = (device_t) arg1;
364 msr = coretemp_get_thermal_msr(device_get_unit(dev));
365 sc = device_get_softc(dev);
366 type = arg2;
367
368 if (((msr >> THERM_STATUS_VALID_SHIFT) & THERM_STATUS_VALID_MASK) != 1) {
369 val = -1;
370 } else {
371 switch (type) {
372 case CORETEMP_TEMP:
373 tmp = (msr >> THERM_STATUS_TEMP_SHIFT) &
374 THERM_STATUS_TEMP_MASK;
375 val = (sc->sc_tjmax - tmp) * 10 + TZ_ZEROC;
376 break;
377 case CORETEMP_DELTA:
378 val = (msr >> THERM_STATUS_TEMP_SHIFT) &
379 THERM_STATUS_TEMP_MASK;
380 break;
381 case CORETEMP_RESOLUTION:
382 val = (msr >> THERM_STATUS_RES_SHIFT) &
383 THERM_STATUS_RES_MASK;
384 break;
385 case CORETEMP_TJMAX:
386 val = sc->sc_tjmax * 10 + TZ_ZEROC;
387 break;
388 }
389 }
390
391 if (msr & THERM_STATUS_LOG) {
392 coretemp_clear_thermal_msr(device_get_unit(dev));
393 sc->sc_throttle_log = 1;
394
395 /*
396 * Check for Critical Temperature Status and Critical
397 * Temperature Log. It doesn't really matter if the
398 * current temperature is invalid because the "Critical
399 * Temperature Log" bit will tell us if the Critical
400 * Temperature has * been reached in past. It's not
401 * directly related to the current temperature.
402 *
403 * If we reach a critical level, allow devctl(4)
404 * to catch this and shutdown the system.
405 */
406 if (msr & THERM_STATUS) {
407 tmp = (msr >> THERM_STATUS_TEMP_SHIFT) &
408 THERM_STATUS_TEMP_MASK;
409 tmp = (sc->sc_tjmax - tmp) * 10 + TZ_ZEROC;
410 device_printf(dev, "critical temperature detected, "
411 "suggest system shutdown\n");
412 snprintf(stemp, sizeof(stemp), "%d", tmp);
413 devctl_notify("coretemp", "Thermal", stemp,
414 "notify=0xcc");
415 }
416 }
417
418 return (sysctl_handle_int(oidp, &val, 0, req));
419 }
420
421 static int
422 coretemp_throttle_log_sysctl(SYSCTL_HANDLER_ARGS)
423 {
424 device_t dev;
425 uint64_t msr;
426 int error, val;
427 struct coretemp_softc *sc;
428
429 dev = (device_t) arg1;
430 msr = coretemp_get_thermal_msr(device_get_unit(dev));
431 sc = device_get_softc(dev);
432
433 if (msr & THERM_STATUS_LOG) {
434 coretemp_clear_thermal_msr(device_get_unit(dev));
435 sc->sc_throttle_log = 1;
436 }
437
438 val = sc->sc_throttle_log;
439
440 error = sysctl_handle_int(oidp, &val, 0, req);
441
442 if (error || !req->newptr)
443 return (error);
444 else if (val != 0)
445 return (EINVAL);
446
447 coretemp_clear_thermal_msr(device_get_unit(dev));
448 sc->sc_throttle_log = 0;
449
450 return (0);
451 }
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