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/7.3/sys/dev/coretemp/coretemp.c 195197 2009-06-30 17:10:08Z avg $");
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 struct coretemp_softc {
52 device_t sc_dev;
53 int sc_tjmax;
54 struct sysctl_oid *sc_oid;
55 };
56
57 /*
58 * Device methods.
59 */
60 static void coretemp_identify(driver_t *driver, device_t parent);
61 static int coretemp_probe(device_t dev);
62 static int coretemp_attach(device_t dev);
63 static int coretemp_detach(device_t dev);
64
65 static int coretemp_get_temp(device_t dev);
66 static int coretemp_get_temp_sysctl(SYSCTL_HANDLER_ARGS);
67
68 static device_method_t coretemp_methods[] = {
69 /* Device interface */
70 DEVMETHOD(device_identify, coretemp_identify),
71 DEVMETHOD(device_probe, coretemp_probe),
72 DEVMETHOD(device_attach, coretemp_attach),
73 DEVMETHOD(device_detach, coretemp_detach),
74
75 {0, 0}
76 };
77
78 static driver_t coretemp_driver = {
79 "coretemp",
80 coretemp_methods,
81 sizeof(struct coretemp_softc),
82 };
83
84 static devclass_t coretemp_devclass;
85 DRIVER_MODULE(coretemp, cpu, coretemp_driver, coretemp_devclass, NULL, NULL);
86
87 static void
88 coretemp_identify(driver_t *driver, device_t parent)
89 {
90 device_t child;
91 u_int regs[4];
92
93 /* Make sure we're not being doubly invoked. */
94 if (device_find_child(parent, "coretemp", -1) != NULL)
95 return;
96
97 /* Check that CPUID 0x06 is supported and the vendor is Intel.*/
98 if (cpu_high < 6 || cpu_vendor_id != CPU_VENDOR_INTEL)
99 return;
100 /*
101 * CPUID 0x06 returns 1 if the processor has on-die thermal
102 * sensors. EBX[0:3] contains the number of sensors.
103 */
104 do_cpuid(0x06, regs);
105 if ((regs[0] & 0x1) != 1)
106 return;
107
108 /*
109 * We add a child for each CPU since settings must be performed
110 * on each CPU in the SMP case.
111 */
112 child = device_add_child(parent, "coretemp", -1);
113 if (child == NULL)
114 device_printf(parent, "add coretemp child failed\n");
115 }
116
117 static int
118 coretemp_probe(device_t dev)
119 {
120 if (resource_disabled("coretemp", 0))
121 return (ENXIO);
122
123 device_set_desc(dev, "CPU On-Die Thermal Sensors");
124
125 return (BUS_PROBE_GENERIC);
126 }
127
128 static int
129 coretemp_attach(device_t dev)
130 {
131 struct coretemp_softc *sc = device_get_softc(dev);
132 device_t pdev;
133 uint64_t msr;
134 int cpu_model;
135 int cpu_mask;
136
137 sc->sc_dev = dev;
138 pdev = device_get_parent(dev);
139 cpu_model = (cpu_id >> 4) & 15;
140 /* extended model */
141 cpu_model += ((cpu_id >> 16) & 0xf) << 4;
142 cpu_mask = cpu_id & 15;
143
144 /*
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.
149 */
150 if (cpu_model < 0xe)
151 return (ENXIO);
152
153 /*
154 * Check for errata AE18.
155 * "Processor Digital Thermal Sensor (DTS) Readout stops
156 * updating upon returning from C3/C4 state."
157 *
158 * Adapted from the Linux coretemp driver.
159 */
160 if (cpu_model == 0xe && cpu_mask < 0xc) {
161 msr = rdmsr(MSR_BIOS_SIGN);
162 msr = msr >> 32;
163 if (msr < 0x39) {
164 device_printf(dev, "not supported (Intel errata "
165 "AE18), try updating your BIOS\n");
166 return (ENXIO);
167 }
168 }
169 /*
170 * On some Core 2 CPUs, there's an undocumented MSR that
171 * can tell us if Tj(max) is 100 or 85.
172 *
173 * The if-clause for CPUs having the MSR_IA32_EXT_CONFIG was adapted
174 * from the Linux coretemp driver.
175 */
176 sc->sc_tjmax = 100;
177 if ((cpu_model == 0xf && cpu_mask >= 2) || cpu_model == 0xe) {
178 msr = rdmsr(MSR_IA32_EXT_CONFIG);
179 if (msr & (1 << 30))
180 sc->sc_tjmax = 85;
181 }
182
183 /*
184 * Add the "temperature" MIB to dev.cpu.N.
185 */
186 sc->sc_oid = SYSCTL_ADD_PROC(device_get_sysctl_ctx(pdev),
187 SYSCTL_CHILDREN(device_get_sysctl_tree(pdev)),
188 OID_AUTO, "temperature",
189 CTLTYPE_INT | CTLFLAG_RD,
190 dev, 0, coretemp_get_temp_sysctl, "I",
191 "Current temperature in degC");
192
193 return (0);
194 }
195
196 static int
197 coretemp_detach(device_t dev)
198 {
199 struct coretemp_softc *sc = device_get_softc(dev);
200
201 sysctl_remove_oid(sc->sc_oid, 1, 0);
202
203 return (0);
204 }
205
206
207 static int
208 coretemp_get_temp(device_t dev)
209 {
210 uint64_t msr;
211 int temp;
212 int cpu = device_get_unit(dev);
213 struct coretemp_softc *sc = device_get_softc(dev);
214 char stemp[16];
215
216 thread_lock(curthread);
217 sched_bind(curthread, cpu);
218 thread_unlock(curthread);
219
220 /*
221 * The digital temperature reading is located at bit 16
222 * of MSR_THERM_STATUS.
223 *
224 * There is a bit on that MSR that indicates whether the
225 * temperature is valid or not.
226 *
227 * The temperature is computed by subtracting the temperature
228 * reading by Tj(max).
229 */
230 msr = rdmsr(MSR_THERM_STATUS);
231
232 thread_lock(curthread);
233 sched_unbind(curthread);
234 thread_unlock(curthread);
235
236 /*
237 * Check for Thermal Status and Thermal Status Log.
238 */
239 if ((msr & 0x3) == 0x3)
240 device_printf(dev, "PROCHOT asserted\n");
241
242 /*
243 * Bit 31 contains "Reading valid"
244 */
245 if (((msr >> 31) & 0x1) == 1) {
246 /*
247 * Starting on bit 16 and ending on bit 22.
248 */
249 temp = sc->sc_tjmax - ((msr >> 16) & 0x7f);
250 } else
251 temp = -1;
252
253 /*
254 * Check for Critical Temperature Status and Critical
255 * Temperature Log.
256 * It doesn't really matter if the current temperature is
257 * invalid because the "Critical Temperature Log" bit will
258 * tell us if the Critical Temperature has been reached in
259 * past. It's not directly related to the current temperature.
260 *
261 * If we reach a critical level, allow devctl(4) to catch this
262 * and shutdown the system.
263 */
264 if (((msr >> 4) & 0x3) == 0x3) {
265 device_printf(dev, "critical temperature detected, "
266 "suggest system shutdown\n");
267 snprintf(stemp, sizeof(stemp), "%d", temp);
268 devctl_notify("coretemp", "Thermal", stemp, "notify=0xcc");
269 }
270
271 return (temp);
272 }
273
274 static int
275 coretemp_get_temp_sysctl(SYSCTL_HANDLER_ARGS)
276 {
277 device_t dev = (device_t) arg1;
278 int temp;
279
280 temp = coretemp_get_temp(dev);
281
282 return (sysctl_handle_int(oidp, &temp, 0, req));
283 }
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