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 #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 } 292