linux/drivers/hwmon/coretemp.c
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   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 */
  50static int force_tjmax;
  51module_param_named(tjmax, force_tjmax, int, 0444);
  52MODULE_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 */
  84struct 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 */
 101struct 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
 108struct pdev_entry {
 109        struct list_head list;
 110        struct platform_device *pdev;
 111        u16 phys_proc_id;
 112};
 113
 114static LIST_HEAD(pdev_list);
 115static DEFINE_MUTEX(pdev_list_mutex);
 116
 117static ssize_t show_name(struct device *dev,
 118                        struct device_attribute *devattr, char *buf)
 119{
 120        return sprintf(buf, "%s\n", DRVNAME);
 121}
 122
 123static 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
 136static 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
 149static 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
 158static 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
 167static 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
 194struct tjmax {
 195        char const *id;
 196        int tjmax;
 197};
 198
 199static const 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
 212static 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
 318static 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
 358static 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
 368static 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
 395exit_free:
 396        while (--i >= 0)
 397                device_remove_file(dev, &tdata->sd_attrs[i].dev_attr);
 398        return err;
 399}
 400
 401
 402static 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
 419static 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
 436static 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
 455static 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;
 520exit_free:
 521        pdata->core_data[attr_no] = NULL;
 522        kfree(tdata);
 523        return err;
 524}
 525
 526static 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
 539static 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
 553static 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
 578exit_name:
 579        device_remove_file(&pdev->dev, &pdata->name_attr);
 580        platform_set_drvdata(pdev, NULL);
 581exit_free:
 582        kfree(pdata);
 583        return err;
 584}
 585
 586static 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
 602static 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
 611static 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
 646exit_device_free:
 647        kfree(pdev_entry);
 648exit_device_put:
 649        platform_device_put(pdev);
 650exit:
 651        mutex_unlock(&pdev_list_mutex);
 652        return err;
 653}
 654
 655static 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
 671static 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
 685static 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
 727static 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
 775static 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
 792static struct notifier_block coretemp_cpu_notifier __refdata = {
 793        .notifier_call = coretemp_cpu_callback,
 794};
 795
 796static const struct x86_cpu_id __initconst coretemp_ids[] = {
 797        { X86_VENDOR_INTEL, X86_FAMILY_ANY, X86_MODEL_ANY, X86_FEATURE_DTHERM },
 798        {}
 799};
 800MODULE_DEVICE_TABLE(x86cpu, coretemp_ids);
 801
 802static 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        get_online_cpus();
 819        for_each_online_cpu(i)
 820                get_core_online(i);
 821
 822#ifndef CONFIG_HOTPLUG_CPU
 823        if (list_empty(&pdev_list)) {
 824                put_online_cpus();
 825                err = -ENODEV;
 826                goto exit_driver_unreg;
 827        }
 828#endif
 829
 830        register_hotcpu_notifier(&coretemp_cpu_notifier);
 831        put_online_cpus();
 832        return 0;
 833
 834#ifndef CONFIG_HOTPLUG_CPU
 835exit_driver_unreg:
 836        platform_driver_unregister(&coretemp_driver);
 837#endif
 838exit:
 839        return err;
 840}
 841
 842static void __exit coretemp_exit(void)
 843{
 844        struct pdev_entry *p, *n;
 845
 846        get_online_cpus();
 847        unregister_hotcpu_notifier(&coretemp_cpu_notifier);
 848        mutex_lock(&pdev_list_mutex);
 849        list_for_each_entry_safe(p, n, &pdev_list, list) {
 850                platform_device_unregister(p->pdev);
 851                list_del(&p->list);
 852                kfree(p);
 853        }
 854        mutex_unlock(&pdev_list_mutex);
 855        put_online_cpus();
 856        platform_driver_unregister(&coretemp_driver);
 857}
 858
 859MODULE_AUTHOR("Rudolf Marek <r.marek@assembler.cz>");
 860MODULE_DESCRIPTION("Intel Core temperature monitor");
 861MODULE_LICENSE("GPL");
 862
 863module_init(coretemp_init)
 864module_exit(coretemp_exit)
 865
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