1 /*-
2 * Copyright (c) 2007, 2008 Rui Paulo <rpaulo@FreeBSD.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
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.
13 *
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.
25 */
26
27 /*
28 * Device driver for Intel's On Die thermal sensor via MSR.
29 * First introduced in Intel's Core line of processors.
30 */
31
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD: releng/8.1/sys/dev/coretemp/coretemp.c 197199 2009-09-14 17:49:59Z jhb $");
34
35 #include <sys/param.h>
36 #include <sys/bus.h>
37 #include <sys/systm.h>
38 #include <sys/types.h>
39 #include <sys/module.h>
40 #include <sys/conf.h>
41 #include <sys/kernel.h>
42 #include <sys/sysctl.h>
43 #include <sys/proc.h> /* for curthread */
44 #include <sys/sched.h>
45
46 #include <machine/specialreg.h>
47 #include <machine/cpufunc.h>
48 #include <machine/cputypes.h>
49 #include <machine/md_var.h>
50
51 #define TZ_ZEROC 2732
52
53 struct coretemp_softc {
54 device_t sc_dev;
55 int sc_tjmax;
56 struct sysctl_oid *sc_oid;
57 };
58
59 /*
60 * Device methods.
61 */
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);
66
67 static int coretemp_get_temp(device_t dev);
68 static int coretemp_get_temp_sysctl(SYSCTL_HANDLER_ARGS);
69
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),
76
77 {0, 0}
78 };
79
80 static driver_t coretemp_driver = {
81 "coretemp",
82 coretemp_methods,
83 sizeof(struct coretemp_softc),
84 };
85
86 static devclass_t coretemp_devclass;
87 DRIVER_MODULE(coretemp, cpu, coretemp_driver, coretemp_devclass, NULL, NULL);
88
89 static void
90 coretemp_identify(driver_t *driver, device_t parent)
91 {
92 device_t child;
93 u_int regs[4];
94
95 /* Make sure we're not being doubly invoked. */
96 if (device_find_child(parent, "coretemp", -1) != NULL)
97 return;
98
99 /* Check that CPUID 0x06 is supported and the vendor is Intel.*/
100 if (cpu_high < 6 || cpu_vendor_id != CPU_VENDOR_INTEL)
101 return;
102 /*
103 * CPUID 0x06 returns 1 if the processor has on-die thermal
104 * sensors. EBX[0:3] contains the number of sensors.
105 */
106 do_cpuid(0x06, regs);
107 if ((regs[0] & 0x1) != 1)
108 return;
109
110 /*
111 * We add a child for each CPU since settings must be performed
112 * on each CPU in the SMP case.
113 */
114 child = device_add_child(parent, "coretemp", -1);
115 if (child == NULL)
116 device_printf(parent, "add coretemp child failed\n");
117 }
118
119 static int
120 coretemp_probe(device_t dev)
121 {
122 if (resource_disabled("coretemp", 0))
123 return (ENXIO);
124
125 device_set_desc(dev, "CPU On-Die Thermal Sensors");
126
127 return (BUS_PROBE_GENERIC);
128 }
129
130 static int
131 coretemp_attach(device_t dev)
132 {
133 struct coretemp_softc *sc = device_get_softc(dev);
134 device_t pdev;
135 uint64_t msr;
136 int cpu_model;
137 int cpu_mask;
138
139 sc->sc_dev = dev;
140 pdev = device_get_parent(dev);
141 cpu_model = (cpu_id >> 4) & 15;
142 /* extended model */
143 cpu_model += ((cpu_id >> 16) & 0xf) << 4;
144 cpu_mask = cpu_id & 15;
145
146 /*
147 * Some CPUs, namely the PIII, don't have thermal sensors, but
148 * report them when the CPUID check is performed in
149 * coretemp_identify(). This leads to a later GPF when the sensor
150 * is queried via a MSR, so we stop here.
151 */
152 if (cpu_model < 0xe)
153 return (ENXIO);
154
155 #if 0 /*
156 * XXXrpaulo: I have this CPU model and when it returns from C3
157 * coretemp continues to function properly.
158 */
159
160 /*
161 * Check for errata AE18.
162 * "Processor Digital Thermal Sensor (DTS) Readout stops
163 * updating upon returning from C3/C4 state."
164 *
165 * Adapted from the Linux coretemp driver.
166 */
167 if (cpu_model == 0xe && cpu_mask < 0xc) {
168 msr = rdmsr(MSR_BIOS_SIGN);
169 msr = msr >> 32;
170 if (msr < 0x39) {
171 device_printf(dev, "not supported (Intel errata "
172 "AE18), try updating your BIOS\n");
173 return (ENXIO);
174 }
175 }
176 #endif
177 /*
178 * On some Core 2 CPUs, there's an undocumented MSR that
179 * can tell us if Tj(max) is 100 or 85.
180 *
181 * The if-clause for CPUs having the MSR_IA32_EXT_CONFIG was adapted
182 * from the Linux coretemp driver.
183 */
184 sc->sc_tjmax = 100;
185 if ((cpu_model == 0xf && cpu_mask >= 2) || cpu_model == 0xe) {
186 msr = rdmsr(MSR_IA32_EXT_CONFIG);
187 if (msr & (1 << 30))
188 sc->sc_tjmax = 85;
189 }
190
191 /*
192 * Add the "temperature" MIB to dev.cpu.N.
193 */
194 sc->sc_oid = SYSCTL_ADD_PROC(device_get_sysctl_ctx(pdev),
195 SYSCTL_CHILDREN(device_get_sysctl_tree(pdev)),
196 OID_AUTO, "temperature",
197 CTLTYPE_INT | CTLFLAG_RD,
198 dev, 0, coretemp_get_temp_sysctl, "IK",
199 "Current temperature");
200
201 return (0);
202 }
203
204 static int
205 coretemp_detach(device_t dev)
206 {
207 struct coretemp_softc *sc = device_get_softc(dev);
208
209 sysctl_remove_oid(sc->sc_oid, 1, 0);
210
211 return (0);
212 }
213
214
215 static int
216 coretemp_get_temp(device_t dev)
217 {
218 uint64_t msr;
219 int temp;
220 int cpu = device_get_unit(dev);
221 struct coretemp_softc *sc = device_get_softc(dev);
222 char stemp[16];
223
224 thread_lock(curthread);
225 sched_bind(curthread, cpu);
226 thread_unlock(curthread);
227
228 /*
229 * The digital temperature reading is located at bit 16
230 * of MSR_THERM_STATUS.
231 *
232 * There is a bit on that MSR that indicates whether the
233 * temperature is valid or not.
234 *
235 * The temperature is computed by subtracting the temperature
236 * reading by Tj(max).
237 */
238 msr = rdmsr(MSR_THERM_STATUS);
239
240 thread_lock(curthread);
241 sched_unbind(curthread);
242 thread_unlock(curthread);
243
244 /*
245 * Check for Thermal Status and Thermal Status Log.
246 */
247 if ((msr & 0x3) == 0x3)
248 device_printf(dev, "PROCHOT asserted\n");
249
250 /*
251 * Bit 31 contains "Reading valid"
252 */
253 if (((msr >> 31) & 0x1) == 1) {
254 /*
255 * Starting on bit 16 and ending on bit 22.
256 */
257 temp = sc->sc_tjmax - ((msr >> 16) & 0x7f);
258 } else
259 temp = -1;
260
261 /*
262 * Check for Critical Temperature Status and Critical
263 * Temperature Log.
264 * It doesn't really matter if the current temperature is
265 * invalid because the "Critical Temperature Log" bit will
266 * tell us if the Critical Temperature has been reached in
267 * past. It's not directly related to the current temperature.
268 *
269 * If we reach a critical level, allow devctl(4) to catch this
270 * and shutdown the system.
271 */
272 if (((msr >> 4) & 0x3) == 0x3) {
273 device_printf(dev, "critical temperature detected, "
274 "suggest system shutdown\n");
275 snprintf(stemp, sizeof(stemp), "%d", temp);
276 devctl_notify("coretemp", "Thermal", stemp, "notify=0xcc");
277 }
278
279 return (temp);
280 }
281
282 static int
283 coretemp_get_temp_sysctl(SYSCTL_HANDLER_ARGS)
284 {
285 device_t dev = (device_t) arg1;
286 int temp;
287
288 temp = coretemp_get_temp(dev) * 10 + TZ_ZEROC;
289
290 return (sysctl_handle_int(oidp, &temp, 0, req));
291 }
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