drivers/hwmon/coretemp.c

   1 /*
   2  * coretemp.c - Linux kernel module for hardware monitoring
   3  *
   4  * Copyright (C) 2007 Rudolf Marek <r.marek@assembler.cz>
   5  *
   6  * Inspired from many hwmon drivers
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; version 2 of the License.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  20  * 02110-1301 USA.
  21  */
  22
  23 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  24
  25 #include <linux/module.h>
  26 #include <linux/init.h>
  27 #include <linux/slab.h>
  28 #include <linux/jiffies.h>
  29 #include <linux/hwmon.h>
  30 #include <linux/sysfs.h>
  31 #include <linux/hwmon-sysfs.h>
  32 #include <linux/err.h>
  33 #include <linux/mutex.h>
  34 #include <linux/list.h>
  35 #include <linux/platform_device.h>
  36 #include <linux/cpu.h>
  37 #include <linux/pci.h>
  38 #include <linux/smp.h>
  39 #include <linux/moduleparam.h>
  40 #include <asm/msr.h>
  41 #include <asm/processor.h>
  42 #include <asm/cpu_device_id.h>
  43
  44 #define DRVNAME "coretemp"
  45
  46 /*
  47  * force_tjmax only matters when TjMax can't be read from the CPU itself.
  48  * When set, it replaces the driver's suboptimal heuristic.
  49  */
  50 static int force_tjmax;
  51 module_param_named(tjmax, force_tjmax, int, 0444);
  52 MODULE_PARM_DESC(tjmax, "TjMax value in degrees Celsius");
  53
  54 #define BASE_SYSFS_ATTR_NO      2       /* Sysfs Base attr no for coretemp */
  55 #define NUM_REAL_CORES          32      /* Number of Real cores per cpu */
  56 #define CORETEMP_NAME_LENGTH    17      /* String Length of attrs */
  57 #define MAX_CORE_ATTRS          4       /* Maximum no of basic attrs */
  58 #define TOTAL_ATTRS             (MAX_CORE_ATTRS + 1)
  59 #define MAX_CORE_DATA           (NUM_REAL_CORES + BASE_SYSFS_ATTR_NO)
  60
  61 #define TO_PHYS_ID(cpu)         (cpu_data(cpu).phys_proc_id)
  62 #define TO_CORE_ID(cpu)         (cpu_data(cpu).cpu_core_id)
  63 #define TO_ATTR_NO(cpu)         (TO_CORE_ID(cpu) + BASE_SYSFS_ATTR_NO)
  64
  65 #ifdef CONFIG_SMP
  66 #define for_each_sibling(i, cpu)        for_each_cpu(i, cpu_sibling_mask(cpu))
  67 #else
  68 #define for_each_sibling(i, cpu)        for (i = 0; false; )
  69 #endif
  70
  71 /*
  72  * Per-Core Temperature Data
  73  * @last_updated: The time when the current temperature value was updated
  74  *              earlier (in jiffies).
  75  * @cpu_core_id: The CPU Core from which temperature values should be read
  76  *              This value is passed as "id" field to rdmsr/wrmsr functions.
  77  * @status_reg: One of IA32_THERM_STATUS or IA32_PACKAGE_THERM_STATUS,
  78  *              from where the temperature values should be read.
  79  * @attr_size:  Total number of pre-core attrs displayed in the sysfs.
  80  * @is_pkg_data: If this is 1, the temp_data holds pkgtemp data.
  81  *              Otherwise, temp_data holds coretemp data.
  82  * @valid: If this is 1, the current temperature is valid.
  83  */
  84 struct temp_data {
  85         int temp;
  86         int ttarget;
  87         int tjmax;
  88         unsigned long last_updated;
  89         unsigned int cpu;
  90         u32 cpu_core_id;
  91         u32 status_reg;
  92         int attr_size;
  93         bool is_pkg_data;
  94         bool valid;
  95         struct sensor_device_attribute sd_attrs[TOTAL_ATTRS];
  96         char attr_name[TOTAL_ATTRS][CORETEMP_NAME_LENGTH];
  97         struct mutex update_lock;
  98 };
  99
 100 /* Platform Data per Physical CPU */
 101 struct platform_data {
 102         struct device *hwmon_dev;
 103         u16 phys_proc_id;
 104         struct temp_data *core_data[MAX_CORE_DATA];
 105         struct device_attribute name_attr;
 106 };
 107
 108 struct pdev_entry {
 109         struct list_head list;
 110         struct platform_device *pdev;
 111         u16 phys_proc_id;
 112 };
 113
 114 static LIST_HEAD(pdev_list);
 115 static DEFINE_MUTEX(pdev_list_mutex);
 116
 117 static ssize_t show_name(struct device *dev,
 118                         struct device_attribute *devattr, char *buf)
 119 {
 120         return sprintf(buf, "%s\n", DRVNAME);
 121 }
 122
 123 static ssize_t show_label(struct device *dev,
 124                                 struct device_attribute *devattr, char *buf)
 125 {
 126         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 127         struct platform_data *pdata = dev_get_drvdata(dev);
 128         struct temp_data *tdata = pdata->core_data[attr->index];
 129
 130         if (tdata->is_pkg_data)
 131                 return sprintf(buf, "Physical id %u\n", pdata->phys_proc_id);
 132
 133         return sprintf(buf, "Core %u\n", tdata->cpu_core_id);
 134 }
 135
 136 static ssize_t show_crit_alarm(struct device *dev,
 137                                 struct device_attribute *devattr, char *buf)
 138 {
 139         u32 eax, edx;
 140         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 141         struct platform_data *pdata = dev_get_drvdata(dev);
 142         struct temp_data *tdata = pdata->core_data[attr->index];
 143
 144         rdmsr_on_cpu(tdata->cpu, tdata->status_reg, &eax, &edx);
 145
 146         return sprintf(buf, "%d\n", (eax >> 5) & 1);
 147 }
 148
 149 static ssize_t show_tjmax(struct device *dev,
 150                         struct device_attribute *devattr, char *buf)
 151 {
 152         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 153         struct platform_data *pdata = dev_get_drvdata(dev);
 154
 155         return sprintf(buf, "%d\n", pdata->core_data[attr->index]->tjmax);
 156 }
 157
 158 static ssize_t show_ttarget(struct device *dev,
 159                                 struct device_attribute *devattr, char *buf)
 160 {
 161         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 162         struct platform_data *pdata = dev_get_drvdata(dev);
 163
 164         return sprintf(buf, "%d\n", pdata->core_data[attr->index]->ttarget);
 165 }
 166
 167 static ssize_t show_temp(struct device *dev,
 168                         struct device_attribute *devattr, char *buf)
 169 {
 170         u32 eax, edx;
 171         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 172         struct platform_data *pdata = dev_get_drvdata(dev);
 173         struct temp_data *tdata = pdata->core_data[attr->index];
 174
 175         mutex_lock(&tdata->update_lock);
 176
 177         /* Check whether the time interval has elapsed */
 178         if (!tdata->valid || time_after(jiffies, tdata->last_updated + HZ)) {
 179                 rdmsr_on_cpu(tdata->cpu, tdata->status_reg, &eax, &edx);
 180                 tdata->valid = 0;
 181                 /* Check whether the data is valid */
 182                 if (eax & 0x80000000) {
 183                         tdata->temp = tdata->tjmax -
 184                                         ((eax >> 16) & 0x7f) * 1000;
 185                         tdata->valid = 1;
 186                 }
 187                 tdata->last_updated = jiffies;
 188         }
 189
 190         mutex_unlock(&tdata->update_lock);
 191         return tdata->valid ? sprintf(buf, "%d\n", tdata->temp) : -EAGAIN;
 192 }
 193
 194 struct tjmax {
 195         char const *id;
 196         int tjmax;
 197 };
 198
 199 static struct tjmax __cpuinitconst tjmax_table[] = {
 200         { "CPU D410", 100000 },
 201         { "CPU D425", 100000 },
 202         { "CPU D510", 100000 },
 203         { "CPU D525", 100000 },
 204         { "CPU N450", 100000 },
 205         { "CPU N455", 100000 },
 206         { "CPU N470", 100000 },
 207         { "CPU N475", 100000 },
 208         { "CPU  230", 100000 },
 209         { "CPU  330", 125000 },
 210 };
 211
 212 static int __cpuinit adjust_tjmax(struct cpuinfo_x86 *c, u32 id,
 213                                   struct device *dev)
 214 {
 215         /* The 100C is default for both mobile and non mobile CPUs */
 216
 217         int tjmax = 100000;
 218         int tjmax_ee = 85000;
 219         int usemsr_ee = 1;
 220         int err;
 221         u32 eax, edx;
 222         struct pci_dev *host_bridge;
 223         int i;
 224
 225         /* explicit tjmax table entries override heuristics */
 226         for (i = 0; i < ARRAY_SIZE(tjmax_table); i++) {
 227                 if (strstr(c->x86_model_id, tjmax_table[i].id))
 228                         return tjmax_table[i].tjmax;
 229         }
 230
 231         /* Early chips have no MSR for TjMax */
 232
 233         if (c->x86_model == 0xf && c->x86_mask < 4)
 234                 usemsr_ee = 0;
 235
 236         /* Atom CPUs */
 237
 238         if (c->x86_model == 0x1c || c->x86_model == 0x26
 239             || c->x86_model == 0x27) {
 240                 usemsr_ee = 0;
 241
 242                 host_bridge = pci_get_bus_and_slot(0, PCI_DEVFN(0, 0));
 243
 244                 if (host_bridge && host_bridge->vendor == PCI_VENDOR_ID_INTEL
 245                     && (host_bridge->device == 0xa000   /* NM10 based nettop */
 246                     || host_bridge->device == 0xa010))  /* NM10 based netbook */
 247                         tjmax = 100000;
 248                 else
 249                         tjmax = 90000;
 250
 251                 pci_dev_put(host_bridge);
 252         } else if (c->x86_model == 0x36) {
 253                 usemsr_ee = 0;
 254                 tjmax = 100000;
 255         }
 256
 257         if (c->x86_model > 0xe && usemsr_ee) {
 258                 u8 platform_id;
 259
 260                 /*
 261                  * Now we can detect the mobile CPU using Intel provided table
 262                  * http://softwarecommunity.intel.com/Wiki/Mobility/720.htm
 263                  * For Core2 cores, check MSR 0x17, bit 28 1 = Mobile CPU
 264                  */
 265                 err = rdmsr_safe_on_cpu(id, 0x17, &eax, &edx);
 266                 if (err) {
 267                         dev_warn(dev,
 268                                  "Unable to access MSR 0x17, assuming desktop"
 269                                  " CPU\n");
 270                         usemsr_ee = 0;
 271                 } else if (c->x86_model < 0x17 && !(eax & 0x10000000)) {
 272                         /*
 273                          * Trust bit 28 up to Penryn, I could not find any
 274                          * documentation on that; if you happen to know
 275                          * someone at Intel please ask
 276                          */
 277                         usemsr_ee = 0;
 278                 } else {
 279                         /* Platform ID bits 52:50 (EDX starts at bit 32) */
 280                         platform_id = (edx >> 18) & 0x7;
 281
 282                         /*
 283                          * Mobile Penryn CPU seems to be platform ID 7 or 5
 284                          * (guesswork)
 285                          */
 286                         if (c->x86_model == 0x17 &&
 287                             (platform_id == 5 || platform_id == 7)) {
 288                                 /*
 289                                  * If MSR EE bit is set, set it to 90 degrees C,
 290                                  * otherwise 105 degrees C
 291                                  */
 292                                 tjmax_ee = 90000;
 293                                 tjmax = 105000;
 294                         }
 295                 }
 296         }
 297
 298         if (usemsr_ee) {
 299                 err = rdmsr_safe_on_cpu(id, 0xee, &eax, &edx);
 300                 if (err) {
 301                         dev_warn(dev,
 302                                  "Unable to access MSR 0xEE, for Tjmax, left"
 303                                  " at default\n");
 304                 } else if (eax & 0x40000000) {
 305                         tjmax = tjmax_ee;
 306                 }
 307         } else if (tjmax == 100000) {
 308                 /*
 309                  * If we don't use msr EE it means we are desktop CPU
 310                  * (with exeception of Atom)
 311                  */
 312                 dev_warn(dev, "Using relative temperature scale!\n");
 313         }
 314
 315         return tjmax;
 316 }
 317
 318 static int __cpuinit get_tjmax(struct cpuinfo_x86 *c, u32 id,
 319                                struct device *dev)
 320 {
 321         int err;
 322         u32 eax, edx;
 323         u32 val;
 324
 325         /*
 326          * A new feature of current Intel(R) processors, the
 327          * IA32_TEMPERATURE_TARGET contains the TjMax value
 328          */
 329         err = rdmsr_safe_on_cpu(id, MSR_IA32_TEMPERATURE_TARGET, &eax, &edx);
 330         if (err) {
 331                 if (c->x86_model > 0xe && c->x86_model != 0x1c)
 332                         dev_warn(dev, "Unable to read TjMax from CPU %u\n", id);
 333         } else {
 334                 val = (eax >> 16) & 0xff;
 335                 /*
 336                  * If the TjMax is not plausible, an assumption
 337                  * will be used
 338                  */
 339                 if (val) {
 340                         dev_dbg(dev, "TjMax is %d degrees C\n", val);
 341                         return val * 1000;
 342                 }
 343         }
 344
 345         if (force_tjmax) {
 346                 dev_notice(dev, "TjMax forced to %d degrees C by user\n",
 347                            force_tjmax);
 348                 return force_tjmax * 1000;
 349         }
 350
 351         /*
 352          * An assumption is made for early CPUs and unreadable MSR.
 353          * NOTE: the calculated value may not be correct.
 354          */
 355         return adjust_tjmax(c, id, dev);
 356 }
 357
 358 static int __devinit create_name_attr(struct platform_data *pdata,
 359                                       struct device *dev)
 360 {
 361         sysfs_attr_init(&pdata->name_attr.attr);
 362         pdata->name_attr.attr.name = "name";
 363         pdata->name_attr.attr.mode = S_IRUGO;
 364         pdata->name_attr.show = show_name;
 365         return device_create_file(dev, &pdata->name_attr);
 366 }
 367
 368 static int __cpuinit create_core_attrs(struct temp_data *tdata,
 369                                        struct device *dev, int attr_no)
 370 {
 371         int err, i;
 372         static ssize_t (*const rd_ptr[TOTAL_ATTRS]) (struct device *dev,
 373                         struct device_attribute *devattr, char *buf) = {
 374                         show_label, show_crit_alarm, show_temp, show_tjmax,
 375                         show_ttarget };
 376         static const char *const names[TOTAL_ATTRS] = {
 377                                         "temp%d_label", "temp%d_crit_alarm",
 378                                         "temp%d_input", "temp%d_crit",
 379                                         "temp%d_max" };
 380
 381         for (i = 0; i < tdata->attr_size; i++) {
 382                 snprintf(tdata->attr_name[i], CORETEMP_NAME_LENGTH, names[i],
 383                         attr_no);
 384                 sysfs_attr_init(&tdata->sd_attrs[i].dev_attr.attr);
 385                 tdata->sd_attrs[i].dev_attr.attr.name = tdata->attr_name[i];
 386                 tdata->sd_attrs[i].dev_attr.attr.mode = S_IRUGO;
 387                 tdata->sd_attrs[i].dev_attr.show = rd_ptr[i];
 388                 tdata->sd_attrs[i].index = attr_no;
 389                 err = device_create_file(dev, &tdata->sd_attrs[i].dev_attr);
 390                 if (err)
 391                         goto exit_free;
 392         }
 393         return 0;
 394
 395 exit_free:
 396         while (--i >= 0)
 397                 device_remove_file(dev, &tdata->sd_attrs[i].dev_attr);
 398         return err;
 399 }
 400
 401
 402 static int __cpuinit chk_ucode_version(unsigned int cpu)
 403 {
 404         struct cpuinfo_x86 *c = &cpu_data(cpu);
 405
 406         /*
 407          * Check if we have problem with errata AE18 of Core processors:
 408          * Readings might stop update when processor visited too deep sleep,
 409          * fixed for stepping D0 (6EC).
 410          */
 411         if (c->x86_model == 0xe && c->x86_mask < 0xc && c->microcode < 0x39) {
 412                 pr_err("Errata AE18 not fixed, update BIOS or "
 413                        "microcode of the CPU!\n");
 414                 return -ENODEV;
 415         }
 416         return 0;
 417 }
 418
 419 static struct platform_device __cpuinit *coretemp_get_pdev(unsigned int cpu)
 420 {
 421         u16 phys_proc_id = TO_PHYS_ID(cpu);
 422         struct pdev_entry *p;
 423
 424         mutex_lock(&pdev_list_mutex);
 425
 426         list_for_each_entry(p, &pdev_list, list)
 427                 if (p->phys_proc_id == phys_proc_id) {
 428                         mutex_unlock(&pdev_list_mutex);
 429                         return p->pdev;
 430                 }
 431
 432         mutex_unlock(&pdev_list_mutex);
 433         return NULL;
 434 }
 435
 436 static struct temp_data __cpuinit *init_temp_data(unsigned int cpu,
 437                                                   int pkg_flag)
 438 {
 439         struct temp_data *tdata;
 440
 441         tdata = kzalloc(sizeof(struct temp_data), GFP_KERNEL);
 442         if (!tdata)
 443                 return NULL;
 444
 445         tdata->status_reg = pkg_flag ? MSR_IA32_PACKAGE_THERM_STATUS :
 446                                                         MSR_IA32_THERM_STATUS;
 447         tdata->is_pkg_data = pkg_flag;
 448         tdata->cpu = cpu;
 449         tdata->cpu_core_id = TO_CORE_ID(cpu);
 450         tdata->attr_size = MAX_CORE_ATTRS;
 451         mutex_init(&tdata->update_lock);
 452         return tdata;
 453 }
 454
 455 static int __cpuinit create_core_data(struct platform_device *pdev,
 456                                 unsigned int cpu, int pkg_flag)
 457 {
 458         struct temp_data *tdata;
 459         struct platform_data *pdata = platform_get_drvdata(pdev);
 460         struct cpuinfo_x86 *c = &cpu_data(cpu);
 461         u32 eax, edx;
 462         int err, attr_no;
 463
 464         /*
 465          * Find attr number for sysfs:
 466          * We map the attr number to core id of the CPU
 467          * The attr number is always core id + 2
 468          * The Pkgtemp will always show up as temp1_*, if available
 469          */
 470         attr_no = pkg_flag ? 1 : TO_ATTR_NO(cpu);
 471
 472         if (attr_no > MAX_CORE_DATA - 1)
 473                 return -ERANGE;
 474
 475         /*
 476          * Provide a single set of attributes for all HT siblings of a core
 477          * to avoid duplicate sensors (the processor ID and core ID of all
 478          * HT siblings of a core are the same).
 479          * Skip if a HT sibling of this core is already registered.
 480          * This is not an error.
 481          */
 482         if (pdata->core_data[attr_no] != NULL)
 483                 return 0;
 484
 485         tdata = init_temp_data(cpu, pkg_flag);
 486         if (!tdata)
 487                 return -ENOMEM;
 488
 489         /* Test if we can access the status register */
 490         err = rdmsr_safe_on_cpu(cpu, tdata->status_reg, &eax, &edx);
 491         if (err)
 492                 goto exit_free;
 493
 494         /* We can access status register. Get Critical Temperature */
 495         tdata->tjmax = get_tjmax(c, cpu, &pdev->dev);
 496
 497         /*
 498          * Read the still undocumented bits 8:15 of IA32_TEMPERATURE_TARGET.
 499          * The target temperature is available on older CPUs but not in this
 500          * register. Atoms don't have the register at all.
 501          */
 502         if (c->x86_model > 0xe && c->x86_model != 0x1c) {
 503                 err = rdmsr_safe_on_cpu(cpu, MSR_IA32_TEMPERATURE_TARGET,
 504                                         &eax, &edx);
 505                 if (!err) {
 506                         tdata->ttarget
 507                           = tdata->tjmax - ((eax >> 8) & 0xff) * 1000;
 508                         tdata->attr_size++;
 509                 }
 510         }
 511
 512         pdata->core_data[attr_no] = tdata;
 513
 514         /* Create sysfs interfaces */
 515         err = create_core_attrs(tdata, &pdev->dev, attr_no);
 516         if (err)
 517                 goto exit_free;
 518
 519         return 0;
 520 exit_free:
 521         pdata->core_data[attr_no] = NULL;
 522         kfree(tdata);
 523         return err;
 524 }
 525
 526 static void __cpuinit coretemp_add_core(unsigned int cpu, int pkg_flag)
 527 {
 528         struct platform_device *pdev = coretemp_get_pdev(cpu);
 529         int err;
 530
 531         if (!pdev)
 532                 return;
 533
 534         err = create_core_data(pdev, cpu, pkg_flag);
 535         if (err)
 536                 dev_err(&pdev->dev, "Adding Core %u failed\n", cpu);
 537 }
 538
 539 static void coretemp_remove_core(struct platform_data *pdata,
 540                                 struct device *dev, int indx)
 541 {
 542         int i;
 543         struct temp_data *tdata = pdata->core_data[indx];
 544
 545         /* Remove the sysfs attributes */
 546         for (i = 0; i < tdata->attr_size; i++)
 547                 device_remove_file(dev, &tdata->sd_attrs[i].dev_attr);
 548
 549         kfree(pdata->core_data[indx]);
 550         pdata->core_data[indx] = NULL;
 551 }
 552
 553 static int __devinit coretemp_probe(struct platform_device *pdev)
 554 {
 555         struct platform_data *pdata;
 556         int err;
 557
 558         /* Initialize the per-package data structures */
 559         pdata = kzalloc(sizeof(struct platform_data), GFP_KERNEL);
 560         if (!pdata)
 561                 return -ENOMEM;
 562
 563         err = create_name_attr(pdata, &pdev->dev);
 564         if (err)
 565                 goto exit_free;
 566
 567         pdata->phys_proc_id = pdev->id;
 568         platform_set_drvdata(pdev, pdata);
 569
 570         pdata->hwmon_dev = hwmon_device_register(&pdev->dev);
 571         if (IS_ERR(pdata->hwmon_dev)) {
 572                 err = PTR_ERR(pdata->hwmon_dev);
 573                 dev_err(&pdev->dev, "Class registration failed (%d)\n", err);
 574                 goto exit_name;
 575         }
 576         return 0;
 577
 578 exit_name:
 579         device_remove_file(&pdev->dev, &pdata->name_attr);
 580         platform_set_drvdata(pdev, NULL);
 581 exit_free:
 582         kfree(pdata);
 583         return err;
 584 }
 585
 586 static int __devexit coretemp_remove(struct platform_device *pdev)
 587 {
 588         struct platform_data *pdata = platform_get_drvdata(pdev);
 589         int i;
 590
 591         for (i = MAX_CORE_DATA - 1; i >= 0; --i)
 592                 if (pdata->core_data[i])
 593                         coretemp_remove_core(pdata, &pdev->dev, i);
 594
 595         device_remove_file(&pdev->dev, &pdata->name_attr);
 596         hwmon_device_unregister(pdata->hwmon_dev);
 597         platform_set_drvdata(pdev, NULL);
 598         kfree(pdata);
 599         return 0;
 600 }
 601
 602 static struct platform_driver coretemp_driver = {
 603         .driver = {
 604                 .owner = THIS_MODULE,
 605                 .name = DRVNAME,
 606         },
 607         .probe = coretemp_probe,
 608         .remove = __devexit_p(coretemp_remove),
 609 };
 610
 611 static int __cpuinit coretemp_device_add(unsigned int cpu)
 612 {
 613         int err;
 614         struct platform_device *pdev;
 615         struct pdev_entry *pdev_entry;
 616
 617         mutex_lock(&pdev_list_mutex);
 618
 619         pdev = platform_device_alloc(DRVNAME, TO_PHYS_ID(cpu));
 620         if (!pdev) {
 621                 err = -ENOMEM;
 622                 pr_err("Device allocation failed\n");
 623                 goto exit;
 624         }
 625
 626         pdev_entry = kzalloc(sizeof(struct pdev_entry), GFP_KERNEL);
 627         if (!pdev_entry) {
 628                 err = -ENOMEM;
 629                 goto exit_device_put;
 630         }
 631
 632         err = platform_device_add(pdev);
 633         if (err) {
 634                 pr_err("Device addition failed (%d)\n", err);
 635                 goto exit_device_free;
 636         }
 637
 638         pdev_entry->pdev = pdev;
 639         pdev_entry->phys_proc_id = pdev->id;
 640
 641         list_add_tail(&pdev_entry->list, &pdev_list);
 642         mutex_unlock(&pdev_list_mutex);
 643
 644         return 0;
 645
 646 exit_device_free:
 647         kfree(pdev_entry);
 648 exit_device_put:
 649         platform_device_put(pdev);
 650 exit:
 651         mutex_unlock(&pdev_list_mutex);
 652         return err;
 653 }
 654
 655 static void __cpuinit coretemp_device_remove(unsigned int cpu)
 656 {
 657         struct pdev_entry *p, *n;
 658         u16 phys_proc_id = TO_PHYS_ID(cpu);
 659
 660         mutex_lock(&pdev_list_mutex);
 661         list_for_each_entry_safe(p, n, &pdev_list, list) {
 662                 if (p->phys_proc_id != phys_proc_id)
 663                         continue;
 664                 platform_device_unregister(p->pdev);
 665                 list_del(&p->list);
 666                 kfree(p);
 667         }
 668         mutex_unlock(&pdev_list_mutex);
 669 }
 670
 671 static bool __cpuinit is_any_core_online(struct platform_data *pdata)
 672 {
 673         int i;
 674
 675         /* Find online cores, except pkgtemp data */
 676         for (i = MAX_CORE_DATA - 1; i >= 0; --i) {
 677                 if (pdata->core_data[i] &&
 678                         !pdata->core_data[i]->is_pkg_data) {
 679                         return true;
 680                 }
 681         }
 682         return false;
 683 }
 684
 685 static void __cpuinit get_core_online(unsigned int cpu)
 686 {
 687         struct cpuinfo_x86 *c = &cpu_data(cpu);
 688         struct platform_device *pdev = coretemp_get_pdev(cpu);
 689         int err;
 690
 691         /*
 692          * CPUID.06H.EAX[0] indicates whether the CPU has thermal
 693          * sensors. We check this bit only, all the early CPUs
 694          * without thermal sensors will be filtered out.
 695          */
 696         if (!cpu_has(c, X86_FEATURE_DTHERM))
 697                 return;
 698
 699         if (!pdev) {
 700                 /* Check the microcode version of the CPU */
 701                 if (chk_ucode_version(cpu))
 702                         return;
 703
 704                 /*
 705                  * Alright, we have DTS support.
 706                  * We are bringing the _first_ core in this pkg
 707                  * online. So, initialize per-pkg data structures and
 708                  * then bring this core online.
 709                  */
 710                 err = coretemp_device_add(cpu);
 711                 if (err)
 712                         return;
 713                 /*
 714                  * Check whether pkgtemp support is available.
 715                  * If so, add interfaces for pkgtemp.
 716                  */
 717                 if (cpu_has(c, X86_FEATURE_PTS))
 718                         coretemp_add_core(cpu, 1);
 719         }
 720         /*
 721          * Physical CPU device already exists.
 722          * So, just add interfaces for this core.
 723          */
 724         coretemp_add_core(cpu, 0);
 725 }
 726
 727 static void __cpuinit put_core_offline(unsigned int cpu)
 728 {
 729         int i, indx;
 730         struct platform_data *pdata;
 731         struct platform_device *pdev = coretemp_get_pdev(cpu);
 732
 733         /* If the physical CPU device does not exist, just return */
 734         if (!pdev)
 735                 return;
 736
 737         pdata = platform_get_drvdata(pdev);
 738
 739         indx = TO_ATTR_NO(cpu);
 740
 741         /* The core id is too big, just return */
 742         if (indx > MAX_CORE_DATA - 1)
 743                 return;
 744
 745         if (pdata->core_data[indx] && pdata->core_data[indx]->cpu == cpu)
 746                 coretemp_remove_core(pdata, &pdev->dev, indx);
 747
 748         /*
 749          * If a HT sibling of a core is taken offline, but another HT sibling
 750          * of the same core is still online, register the alternate sibling.
 751          * This ensures that exactly one set of attributes is provided as long
 752          * as at least one HT sibling of a core is online.
 753          */
 754         for_each_sibling(i, cpu) {
 755                 if (i != cpu) {
 756                         get_core_online(i);
 757                         /*
 758                          * Display temperature sensor data for one HT sibling
 759                          * per core only, so abort the loop after one such
 760                          * sibling has been found.
 761                          */
 762                         break;
 763                 }
 764         }
 765         /*
 766          * If all cores in this pkg are offline, remove the device.
 767          * coretemp_device_remove calls unregister_platform_device,
 768          * which in turn calls coretemp_remove. This removes the
 769          * pkgtemp entry and does other clean ups.
 770          */
 771         if (!is_any_core_online(pdata))
 772                 coretemp_device_remove(cpu);
 773 }
 774
 775 static int __cpuinit coretemp_cpu_callback(struct notifier_block *nfb,
 776                                  unsigned long action, void *hcpu)
 777 {
 778         unsigned int cpu = (unsigned long) hcpu;
 779
 780         switch (action) {
 781         case CPU_ONLINE:
 782         case CPU_DOWN_FAILED:
 783                 get_core_online(cpu);
 784                 break;
 785         case CPU_DOWN_PREPARE:
 786                 put_core_offline(cpu);
 787                 break;
 788         }
 789         return NOTIFY_OK;
 790 }
 791
 792 static struct notifier_block coretemp_cpu_notifier __refdata = {
 793         .notifier_call = coretemp_cpu_callback,
 794 };
 795
 796 static const struct x86_cpu_id coretemp_ids[] = {
 797         { X86_VENDOR_INTEL, X86_FAMILY_ANY, X86_MODEL_ANY, X86_FEATURE_DTHERM },
 798         {}
 799 };
 800 MODULE_DEVICE_TABLE(x86cpu, coretemp_ids);
 801
 802 static int __init coretemp_init(void)
 803 {
 804         int i, err;
 805
 806         /*
 807          * CPUID.06H.EAX[0] indicates whether the CPU has thermal
 808          * sensors. We check this bit only, all the early CPUs
 809          * without thermal sensors will be filtered out.
 810          */
 811         if (!x86_match_cpu(coretemp_ids))
 812                 return -ENODEV;
 813
 814         err = platform_driver_register(&coretemp_driver);
 815         if (err)
 816                 goto exit;
 817
 818         for_each_online_cpu(i)
 819                 get_core_online(i);
 820
 821 #ifndef CONFIG_HOTPLUG_CPU
 822         if (list_empty(&pdev_list)) {
 823                 err = -ENODEV;
 824                 goto exit_driver_unreg;
 825         }
 826 #endif
 827
 828         register_hotcpu_notifier(&coretemp_cpu_notifier);
 829         return 0;
 830
 831 #ifndef CONFIG_HOTPLUG_CPU
 832 exit_driver_unreg:
 833         platform_driver_unregister(&coretemp_driver);
 834 #endif
 835 exit:
 836         return err;
 837 }
 838
 839 static void __exit coretemp_exit(void)
 840 {
 841         struct pdev_entry *p, *n;
 842
 843         unregister_hotcpu_notifier(&coretemp_cpu_notifier);
 844         mutex_lock(&pdev_list_mutex);
 845         list_for_each_entry_safe(p, n, &pdev_list, list) {
 846                 platform_device_unregister(p->pdev);
 847                 list_del(&p->list);
 848                 kfree(p);
 849         }
 850         mutex_unlock(&pdev_list_mutex);
 851         platform_driver_unregister(&coretemp_driver);
 852 }
 853
 854 MODULE_AUTHOR("Rudolf Marek <r.marek@assembler.cz>");
 855 MODULE_DESCRIPTION("Intel Core temperature monitor");
 856 MODULE_LICENSE("GPL");
 857
 858 module_init(coretemp_init)
 859 module_exit(coretemp_exit)