1 /*-
2 * Copyright (c) 2007 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 * $FreeBSD$
27 *
28 */
29
30 /*
31 * Device driver for Intel's On Die thermal sensor via MSR.
32 * First introduced in Intel's Core line of processors.
33 */
34
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
37
38 #include <sys/param.h>
39 #include <sys/bus.h>
40 #include <sys/systm.h>
41 #include <sys/types.h>
42 #include <sys/module.h>
43 #include <sys/conf.h>
44 #include <sys/kernel.h>
45 #include <sys/sysctl.h>
46 #include <sys/proc.h> /* for curthread */
47 #include <sys/sched.h>
48
49 #include <machine/specialreg.h>
50 #include <machine/cpufunc.h>
51 #include <machine/md_var.h>
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 is supported and the vendor is Intel.*/
100 if (cpu_high == 0 || strcmp(cpu_vendor, "GenuineIntel"))
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 * Check for errata AE18.
148 * "Processor Digital Thermal Sensor (DTS) Readout stops
149 * updating upon returning from C3/C4 state."
150 *
151 * Adapted from the Linux coretemp driver.
152 */
153 if (cpu_model == 0xe && cpu_mask < 0xc) {
154 msr = rdmsr(MSR_BIOS_SIGN);
155 msr = msr >> 32;
156 if (msr < 0x39) {
157 device_printf(dev, "not supported (Intel errata "
158 "AE18), try updating your BIOS\n");
159 return (ENXIO);
160 }
161 }
162 /*
163 * On some Core 2 CPUs, there's an undocumented MSR that
164 * can tell us if Tj(max) is 100 or 85.
165 *
166 * The if-clause for CPUs having the MSR_IA32_EXT_CONFIG was adapted
167 * from the Linux coretemp driver.
168 */
169 sc->sc_tjmax = 100;
170 if ((cpu_model == 0xf && cpu_mask >= 2) || cpu_model == 0xe) {
171 msr = rdmsr(MSR_IA32_EXT_CONFIG);
172 if (msr & (1 << 30))
173 sc->sc_tjmax = 85;
174 }
175
176 /*
177 * Add the "temperature" MIB to dev.cpu.N.
178 */
179 sc->sc_oid = SYSCTL_ADD_PROC(device_get_sysctl_ctx(pdev),
180 SYSCTL_CHILDREN(device_get_sysctl_tree(pdev)),
181 OID_AUTO, "temperature",
182 CTLTYPE_INT | CTLFLAG_RD,
183 dev, 0, coretemp_get_temp_sysctl, "I",
184 "Current temperature in degC");
185
186 return (0);
187 }
188
189 static int
190 coretemp_detach(device_t dev)
191 {
192 struct coretemp_softc *sc = device_get_softc(dev);
193
194 sysctl_remove_oid(sc->sc_oid, 1, 0);
195
196 return (0);
197 }
198
199
200 static int
201 coretemp_get_temp(device_t dev)
202 {
203 uint64_t msr;
204 int temp;
205 int cpu = device_get_unit(dev);
206 struct coretemp_softc *sc = device_get_softc(dev);
207 char stemp[16];
208
209 thread_lock(curthread);
210 sched_bind(curthread, cpu);
211 thread_unlock(curthread);
212
213 /*
214 * The digital temperature reading is located at bit 16
215 * of MSR_THERM_STATUS.
216 *
217 * There is a bit on that MSR that indicates whether the
218 * temperature is valid or not.
219 *
220 * The temperature is computed by subtracting the temperature
221 * reading by Tj(max).
222 */
223 msr = rdmsr(MSR_THERM_STATUS);
224
225 thread_lock(curthread);
226 sched_unbind(curthread);
227 thread_unlock(curthread);
228
229 /*
230 * Check for Thermal Status and Thermal Status Log.
231 */
232 if ((msr & 0x3) == 0x3)
233 device_printf(dev, "PROCHOT asserted\n");
234
235 /*
236 * Bit 31 contains "Reading valid"
237 */
238 if (((msr >> 31) & 0x1) == 1) {
239 /*
240 * Starting on bit 16 and ending on bit 22.
241 */
242 temp = sc->sc_tjmax - ((msr >> 16) & 0x7f);
243 } else
244 temp = -1;
245
246 /*
247 * Check for Critical Temperature Status and Critical
248 * Temperature Log.
249 * It doesn't really matter if the current temperature is
250 * invalid because the "Critical Temperature Log" bit will
251 * tell us if the Critical Temperature has been reached in
252 * past. It's not directly related to the current temperature.
253 *
254 * If we reach a critical level, allow devctl(4) to catch this
255 * and shutdown the system.
256 */
257 if (((msr >> 4) & 0x3) == 0x3) {
258 device_printf(dev, "critical temperature detected, "
259 "suggest system shutdown\n");
260 snprintf(stemp, sizeof(stemp), "%d", temp);
261 devctl_notify("coretemp", "Thermal", stemp, "notify=0xcc");
262 }
263
264 return (temp);
265 }
266
267 static int
268 coretemp_get_temp_sysctl(SYSCTL_HANDLER_ARGS)
269 {
270 device_t dev = (device_t) arg1;
271 int temp;
272
273 temp = coretemp_get_temp(dev);
274
275 return (sysctl_handle_int(oidp, &temp, 0, req));
276 }
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