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("$FreeBSD$"); 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 #if 0 /* 154 * XXXrpaulo: I have this CPU model and when it returns from C3 155 * coretemp continues to function properly. 156 */ 157 158 /* 159 * Check for errata AE18. 160 * "Processor Digital Thermal Sensor (DTS) Readout stops 161 * updating upon returning from C3/C4 state." 162 * 163 * Adapted from the Linux coretemp driver. 164 */ 165 if (cpu_model == 0xe && cpu_mask < 0xc) { 166 msr = rdmsr(MSR_BIOS_SIGN); 167 msr = msr >> 32; 168 if (msr < 0x39) { 169 device_printf(dev, "not supported (Intel errata " 170 "AE18), try updating your BIOS\n"); 171 return (ENXIO); 172 } 173 } 174 #endif 175 /* 176 * On some Core 2 CPUs, there's an undocumented MSR that 177 * can tell us if Tj(max) is 100 or 85. 178 * 179 * The if-clause for CPUs having the MSR_IA32_EXT_CONFIG was adapted 180 * from the Linux coretemp driver. 181 */ 182 sc->sc_tjmax = 100; 183 if ((cpu_model == 0xf && cpu_mask >= 2) || cpu_model == 0xe) { 184 msr = rdmsr(MSR_IA32_EXT_CONFIG); 185 if (msr & (1 << 30)) 186 sc->sc_tjmax = 85; 187 } 188 189 /* 190 * Add the "temperature" MIB to dev.cpu.N. 191 */ 192 sc->sc_oid = SYSCTL_ADD_PROC(device_get_sysctl_ctx(pdev), 193 SYSCTL_CHILDREN(device_get_sysctl_tree(pdev)), 194 OID_AUTO, "temperature", 195 CTLTYPE_INT | CTLFLAG_RD, 196 dev, 0, coretemp_get_temp_sysctl, "I", 197 "Current temperature in degC"); 198 199 return (0); 200 } 201 202 static int 203 coretemp_detach(device_t dev) 204 { 205 struct coretemp_softc *sc = device_get_softc(dev); 206 207 sysctl_remove_oid(sc->sc_oid, 1, 0); 208 209 return (0); 210 } 211 212 213 static int 214 coretemp_get_temp(device_t dev) 215 { 216 uint64_t msr; 217 int temp; 218 int cpu = device_get_unit(dev); 219 struct coretemp_softc *sc = device_get_softc(dev); 220 char stemp[16]; 221 222 thread_lock(curthread); 223 sched_bind(curthread, cpu); 224 thread_unlock(curthread); 225 226 /* 227 * The digital temperature reading is located at bit 16 228 * of MSR_THERM_STATUS. 229 * 230 * There is a bit on that MSR that indicates whether the 231 * temperature is valid or not. 232 * 233 * The temperature is computed by subtracting the temperature 234 * reading by Tj(max). 235 */ 236 msr = rdmsr(MSR_THERM_STATUS); 237 238 thread_lock(curthread); 239 sched_unbind(curthread); 240 thread_unlock(curthread); 241 242 /* 243 * Check for Thermal Status and Thermal Status Log. 244 */ 245 if ((msr & 0x3) == 0x3) 246 device_printf(dev, "PROCHOT asserted\n"); 247 248 /* 249 * Bit 31 contains "Reading valid" 250 */ 251 if (((msr >> 31) & 0x1) == 1) { 252 /* 253 * Starting on bit 16 and ending on bit 22. 254 */ 255 temp = sc->sc_tjmax - ((msr >> 16) & 0x7f); 256 } else 257 temp = -1; 258 259 /* 260 * Check for Critical Temperature Status and Critical 261 * Temperature Log. 262 * It doesn't really matter if the current temperature is 263 * invalid because the "Critical Temperature Log" bit will 264 * tell us if the Critical Temperature has been reached in 265 * past. It's not directly related to the current temperature. 266 * 267 * If we reach a critical level, allow devctl(4) to catch this 268 * and shutdown the system. 269 */ 270 if (((msr >> 4) & 0x3) == 0x3) { 271 device_printf(dev, "critical temperature detected, " 272 "suggest system shutdown\n"); 273 snprintf(stemp, sizeof(stemp), "%d", temp); 274 devctl_notify("coretemp", "Thermal", stemp, "notify=0xcc"); 275 } 276 277 return (temp); 278 } 279 280 static int 281 coretemp_get_temp_sysctl(SYSCTL_HANDLER_ARGS) 282 { 283 device_t dev = (device_t) arg1; 284 int temp; 285 286 temp = coretemp_get_temp(dev); 287 288 return (sysctl_handle_int(oidp, &temp, 0, req)); 289 } 290