linux/drivers/hwmon/coretemp.c
<<
>>
Prefs
   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 },         /* Model 0x1c, stepping 2       */
 209        { "CPU  330", 125000 },         /* Model 0x1c, stepping 2       */
 210        { "CPU CE4110", 110000 },       /* Model 0x1c, stepping 10      */
 211        { "CPU CE4150", 110000 },       /* Model 0x1c, stepping 10      */
 212        { "CPU CE4170", 110000 },       /* Model 0x1c, stepping 10      */
 213};
 214
 215static int __cpuinit adjust_tjmax(struct cpuinfo_x86 *c, u32 id,
 216                                  struct device *dev)
 217{
 218        /* The 100C is default for both mobile and non mobile CPUs */
 219
 220        int tjmax = 100000;
 221        int tjmax_ee = 85000;
 222        int usemsr_ee = 1;
 223        int err;
 224        u32 eax, edx;
 225        struct pci_dev *host_bridge;
 226        int i;
 227
 228        /* explicit tjmax table entries override heuristics */
 229        for (i = 0; i < ARRAY_SIZE(tjmax_table); i++) {
 230                if (strstr(c->x86_model_id, tjmax_table[i].id))
 231                        return tjmax_table[i].tjmax;
 232        }
 233
 234        /* Early chips have no MSR for TjMax */
 235
 236        if (c->x86_model == 0xf && c->x86_mask < 4)
 237                usemsr_ee = 0;
 238
 239        /* Atom CPUs */
 240
 241        if (c->x86_model == 0x1c || c->x86_model == 0x26
 242            || c->x86_model == 0x27) {
 243                usemsr_ee = 0;
 244
 245                host_bridge = pci_get_bus_and_slot(0, PCI_DEVFN(0, 0));
 246
 247                if (host_bridge && host_bridge->vendor == PCI_VENDOR_ID_INTEL
 248                    && (host_bridge->device == 0xa000   /* NM10 based nettop */
 249                    || host_bridge->device == 0xa010))  /* NM10 based netbook */
 250                        tjmax = 100000;
 251                else
 252                        tjmax = 90000;
 253
 254                pci_dev_put(host_bridge);
 255        } else if (c->x86_model == 0x36) {
 256                usemsr_ee = 0;
 257                tjmax = 100000;
 258        }
 259
 260        if (c->x86_model > 0xe && usemsr_ee) {
 261                u8 platform_id;
 262
 263                /*
 264                 * Now we can detect the mobile CPU using Intel provided table
 265                 * http://softwarecommunity.intel.com/Wiki/Mobility/720.htm
 266                 * For Core2 cores, check MSR 0x17, bit 28 1 = Mobile CPU
 267                 */
 268                err = rdmsr_safe_on_cpu(id, 0x17, &eax, &edx);
 269                if (err) {
 270                        dev_warn(dev,
 271                                 "Unable to access MSR 0x17, assuming desktop"
 272                                 " CPU\n");
 273                        usemsr_ee = 0;
 274                } else if (c->x86_model < 0x17 && !(eax & 0x10000000)) {
 275                        /*
 276                         * Trust bit 28 up to Penryn, I could not find any
 277                         * documentation on that; if you happen to know
 278                         * someone at Intel please ask
 279                         */
 280                        usemsr_ee = 0;
 281                } else {
 282                        /* Platform ID bits 52:50 (EDX starts at bit 32) */
 283                        platform_id = (edx >> 18) & 0x7;
 284
 285                        /*
 286                         * Mobile Penryn CPU seems to be platform ID 7 or 5
 287                         * (guesswork)
 288                         */
 289                        if (c->x86_model == 0x17 &&
 290                            (platform_id == 5 || platform_id == 7)) {
 291                                /*
 292                                 * If MSR EE bit is set, set it to 90 degrees C,
 293                                 * otherwise 105 degrees C
 294                                 */
 295                                tjmax_ee = 90000;
 296                                tjmax = 105000;
 297                        }
 298                }
 299        }
 300
 301        if (usemsr_ee) {
 302                err = rdmsr_safe_on_cpu(id, 0xee, &eax, &edx);
 303                if (err) {
 304                        dev_warn(dev,
 305                                 "Unable to access MSR 0xEE, for Tjmax, left"
 306                                 " at default\n");
 307                } else if (eax & 0x40000000) {
 308                        tjmax = tjmax_ee;
 309                }
 310        } else if (tjmax == 100000) {
 311                /*
 312                 * If we don't use msr EE it means we are desktop CPU
 313                 * (with exeception of Atom)
 314                 */
 315                dev_warn(dev, "Using relative temperature scale!\n");
 316        }
 317
 318        return tjmax;
 319}
 320
 321static int __cpuinit get_tjmax(struct cpuinfo_x86 *c, u32 id,
 322                               struct device *dev)
 323{
 324        int err;
 325        u32 eax, edx;
 326        u32 val;
 327
 328        /*
 329         * A new feature of current Intel(R) processors, the
 330         * IA32_TEMPERATURE_TARGET contains the TjMax value
 331         */
 332        err = rdmsr_safe_on_cpu(id, MSR_IA32_TEMPERATURE_TARGET, &eax, &edx);
 333        if (err) {
 334                if (c->x86_model > 0xe && c->x86_model != 0x1c)
 335                        dev_warn(dev, "Unable to read TjMax from CPU %u\n", id);
 336        } else {
 337                val = (eax >> 16) & 0xff;
 338                /*
 339                 * If the TjMax is not plausible, an assumption
 340                 * will be used
 341                 */
 342                if (val) {
 343                        dev_dbg(dev, "TjMax is %d degrees C\n", val);
 344                        return val * 1000;
 345                }
 346        }
 347
 348        if (force_tjmax) {
 349                dev_notice(dev, "TjMax forced to %d degrees C by user\n",
 350                           force_tjmax);
 351                return force_tjmax * 1000;
 352        }
 353
 354        /*
 355         * An assumption is made for early CPUs and unreadable MSR.
 356         * NOTE: the calculated value may not be correct.
 357         */
 358        return adjust_tjmax(c, id, dev);
 359}
 360
 361static int __devinit create_name_attr(struct platform_data *pdata,
 362                                      struct device *dev)
 363{
 364        sysfs_attr_init(&pdata->name_attr.attr);
 365        pdata->name_attr.attr.name = "name";
 366        pdata->name_attr.attr.mode = S_IRUGO;
 367        pdata->name_attr.show = show_name;
 368        return device_create_file(dev, &pdata->name_attr);
 369}
 370
 371static int __cpuinit create_core_attrs(struct temp_data *tdata,
 372                                       struct device *dev, int attr_no)
 373{
 374        int err, i;
 375        static ssize_t (*const rd_ptr[TOTAL_ATTRS]) (struct device *dev,
 376                        struct device_attribute *devattr, char *buf) = {
 377                        show_label, show_crit_alarm, show_temp, show_tjmax,
 378                        show_ttarget };
 379        static const char *const names[TOTAL_ATTRS] = {
 380                                        "temp%d_label", "temp%d_crit_alarm",
 381                                        "temp%d_input", "temp%d_crit",
 382                                        "temp%d_max" };
 383
 384        for (i = 0; i < tdata->attr_size; i++) {
 385                snprintf(tdata->attr_name[i], CORETEMP_NAME_LENGTH, names[i],
 386                        attr_no);
 387                sysfs_attr_init(&tdata->sd_attrs[i].dev_attr.attr);
 388                tdata->sd_attrs[i].dev_attr.attr.name = tdata->attr_name[i];
 389                tdata->sd_attrs[i].dev_attr.attr.mode = S_IRUGO;
 390                tdata->sd_attrs[i].dev_attr.show = rd_ptr[i];
 391                tdata->sd_attrs[i].index = attr_no;
 392                err = device_create_file(dev, &tdata->sd_attrs[i].dev_attr);
 393                if (err)
 394                        goto exit_free;
 395        }
 396        return 0;
 397
 398exit_free:
 399        while (--i >= 0)
 400                device_remove_file(dev, &tdata->sd_attrs[i].dev_attr);
 401        return err;
 402}
 403
 404
 405static int __cpuinit chk_ucode_version(unsigned int cpu)
 406{
 407        struct cpuinfo_x86 *c = &cpu_data(cpu);
 408
 409        /*
 410         * Check if we have problem with errata AE18 of Core processors:
 411         * Readings might stop update when processor visited too deep sleep,
 412         * fixed for stepping D0 (6EC).
 413         */
 414        if (c->x86_model == 0xe && c->x86_mask < 0xc && c->microcode < 0x39) {
 415                pr_err("Errata AE18 not fixed, update BIOS or "
 416                       "microcode of the CPU!\n");
 417                return -ENODEV;
 418        }
 419        return 0;
 420}
 421
 422static struct platform_device __cpuinit *coretemp_get_pdev(unsigned int cpu)
 423{
 424        u16 phys_proc_id = TO_PHYS_ID(cpu);
 425        struct pdev_entry *p;
 426
 427        mutex_lock(&pdev_list_mutex);
 428
 429        list_for_each_entry(p, &pdev_list, list)
 430                if (p->phys_proc_id == phys_proc_id) {
 431                        mutex_unlock(&pdev_list_mutex);
 432                        return p->pdev;
 433                }
 434
 435        mutex_unlock(&pdev_list_mutex);
 436        return NULL;
 437}
 438
 439static struct temp_data __cpuinit *init_temp_data(unsigned int cpu,
 440                                                  int pkg_flag)
 441{
 442        struct temp_data *tdata;
 443
 444        tdata = kzalloc(sizeof(struct temp_data), GFP_KERNEL);
 445        if (!tdata)
 446                return NULL;
 447
 448        tdata->status_reg = pkg_flag ? MSR_IA32_PACKAGE_THERM_STATUS :
 449                                                        MSR_IA32_THERM_STATUS;
 450        tdata->is_pkg_data = pkg_flag;
 451        tdata->cpu = cpu;
 452        tdata->cpu_core_id = TO_CORE_ID(cpu);
 453        tdata->attr_size = MAX_CORE_ATTRS;
 454        mutex_init(&tdata->update_lock);
 455        return tdata;
 456}
 457
 458static int __cpuinit create_core_data(struct platform_device *pdev,
 459                                unsigned int cpu, int pkg_flag)
 460{
 461        struct temp_data *tdata;
 462        struct platform_data *pdata = platform_get_drvdata(pdev);
 463        struct cpuinfo_x86 *c = &cpu_data(cpu);
 464        u32 eax, edx;
 465        int err, attr_no;
 466
 467        /*
 468         * Find attr number for sysfs:
 469         * We map the attr number to core id of the CPU
 470         * The attr number is always core id + 2
 471         * The Pkgtemp will always show up as temp1_*, if available
 472         */
 473        attr_no = pkg_flag ? 1 : TO_ATTR_NO(cpu);
 474
 475        if (attr_no > MAX_CORE_DATA - 1)
 476                return -ERANGE;
 477
 478        /*
 479         * Provide a single set of attributes for all HT siblings of a core
 480         * to avoid duplicate sensors (the processor ID and core ID of all
 481         * HT siblings of a core are the same).
 482         * Skip if a HT sibling of this core is already registered.
 483         * This is not an error.
 484         */
 485        if (pdata->core_data[attr_no] != NULL)
 486                return 0;
 487
 488        tdata = init_temp_data(cpu, pkg_flag);
 489        if (!tdata)
 490                return -ENOMEM;
 491
 492        /* Test if we can access the status register */
 493        err = rdmsr_safe_on_cpu(cpu, tdata->status_reg, &eax, &edx);
 494        if (err)
 495                goto exit_free;
 496
 497        /* We can access status register. Get Critical Temperature */
 498        tdata->tjmax = get_tjmax(c, cpu, &pdev->dev);
 499
 500        /*
 501         * Read the still undocumented bits 8:15 of IA32_TEMPERATURE_TARGET.
 502         * The target temperature is available on older CPUs but not in this
 503         * register. Atoms don't have the register at all.
 504         */
 505        if (c->x86_model > 0xe && c->x86_model != 0x1c) {
 506                err = rdmsr_safe_on_cpu(cpu, MSR_IA32_TEMPERATURE_TARGET,
 507                                        &eax, &edx);
 508                if (!err) {
 509                        tdata->ttarget
 510                          = tdata->tjmax - ((eax >> 8) & 0xff) * 1000;
 511                        tdata->attr_size++;
 512                }
 513        }
 514
 515        pdata->core_data[attr_no] = tdata;
 516
 517        /* Create sysfs interfaces */
 518        err = create_core_attrs(tdata, &pdev->dev, attr_no);
 519        if (err)
 520                goto exit_free;
 521
 522        return 0;
 523exit_free:
 524        pdata->core_data[attr_no] = NULL;
 525        kfree(tdata);
 526        return err;
 527}
 528
 529static void __cpuinit coretemp_add_core(unsigned int cpu, int pkg_flag)
 530{
 531        struct platform_device *pdev = coretemp_get_pdev(cpu);
 532        int err;
 533
 534        if (!pdev)
 535                return;
 536
 537        err = create_core_data(pdev, cpu, pkg_flag);
 538        if (err)
 539                dev_err(&pdev->dev, "Adding Core %u failed\n", cpu);
 540}
 541
 542static void coretemp_remove_core(struct platform_data *pdata,
 543                                struct device *dev, int indx)
 544{
 545        int i;
 546        struct temp_data *tdata = pdata->core_data[indx];
 547
 548        /* Remove the sysfs attributes */
 549        for (i = 0; i < tdata->attr_size; i++)
 550                device_remove_file(dev, &tdata->sd_attrs[i].dev_attr);
 551
 552        kfree(pdata->core_data[indx]);
 553        pdata->core_data[indx] = NULL;
 554}
 555
 556static int __devinit coretemp_probe(struct platform_device *pdev)
 557{
 558        struct platform_data *pdata;
 559        int err;
 560
 561        /* Initialize the per-package data structures */
 562        pdata = kzalloc(sizeof(struct platform_data), GFP_KERNEL);
 563        if (!pdata)
 564                return -ENOMEM;
 565
 566        err = create_name_attr(pdata, &pdev->dev);
 567        if (err)
 568                goto exit_free;
 569
 570        pdata->phys_proc_id = pdev->id;
 571        platform_set_drvdata(pdev, pdata);
 572
 573        pdata->hwmon_dev = hwmon_device_register(&pdev->dev);
 574        if (IS_ERR(pdata->hwmon_dev)) {
 575                err = PTR_ERR(pdata->hwmon_dev);
 576                dev_err(&pdev->dev, "Class registration failed (%d)\n", err);
 577                goto exit_name;
 578        }
 579        return 0;
 580
 581exit_name:
 582        device_remove_file(&pdev->dev, &pdata->name_attr);
 583        platform_set_drvdata(pdev, NULL);
 584exit_free:
 585        kfree(pdata);
 586        return err;
 587}
 588
 589static int __devexit coretemp_remove(struct platform_device *pdev)
 590{
 591        struct platform_data *pdata = platform_get_drvdata(pdev);
 592        int i;
 593
 594        for (i = MAX_CORE_DATA - 1; i >= 0; --i)
 595                if (pdata->core_data[i])
 596                        coretemp_remove_core(pdata, &pdev->dev, i);
 597
 598        device_remove_file(&pdev->dev, &pdata->name_attr);
 599        hwmon_device_unregister(pdata->hwmon_dev);
 600        platform_set_drvdata(pdev, NULL);
 601        kfree(pdata);
 602        return 0;
 603}
 604
 605static struct platform_driver coretemp_driver = {
 606        .driver = {
 607                .owner = THIS_MODULE,
 608                .name = DRVNAME,
 609        },
 610        .probe = coretemp_probe,
 611        .remove = __devexit_p(coretemp_remove),
 612};
 613
 614static int __cpuinit coretemp_device_add(unsigned int cpu)
 615{
 616        int err;
 617        struct platform_device *pdev;
 618        struct pdev_entry *pdev_entry;
 619
 620        mutex_lock(&pdev_list_mutex);
 621
 622        pdev = platform_device_alloc(DRVNAME, TO_PHYS_ID(cpu));
 623        if (!pdev) {
 624                err = -ENOMEM;
 625                pr_err("Device allocation failed\n");
 626                goto exit;
 627        }
 628
 629        pdev_entry = kzalloc(sizeof(struct pdev_entry), GFP_KERNEL);
 630        if (!pdev_entry) {
 631                err = -ENOMEM;
 632                goto exit_device_put;
 633        }
 634
 635        err = platform_device_add(pdev);
 636        if (err) {
 637                pr_err("Device addition failed (%d)\n", err);
 638                goto exit_device_free;
 639        }
 640
 641        pdev_entry->pdev = pdev;
 642        pdev_entry->phys_proc_id = pdev->id;
 643
 644        list_add_tail(&pdev_entry->list, &pdev_list);
 645        mutex_unlock(&pdev_list_mutex);
 646
 647        return 0;
 648
 649exit_device_free:
 650        kfree(pdev_entry);
 651exit_device_put:
 652        platform_device_put(pdev);
 653exit:
 654        mutex_unlock(&pdev_list_mutex);
 655        return err;
 656}
 657
 658static void __cpuinit coretemp_device_remove(unsigned int cpu)
 659{
 660        struct pdev_entry *p, *n;
 661        u16 phys_proc_id = TO_PHYS_ID(cpu);
 662
 663        mutex_lock(&pdev_list_mutex);
 664        list_for_each_entry_safe(p, n, &pdev_list, list) {
 665                if (p->phys_proc_id != phys_proc_id)
 666                        continue;
 667                platform_device_unregister(p->pdev);
 668                list_del(&p->list);
 669                kfree(p);
 670        }
 671        mutex_unlock(&pdev_list_mutex);
 672}
 673
 674static bool __cpuinit is_any_core_online(struct platform_data *pdata)
 675{
 676        int i;
 677
 678        /* Find online cores, except pkgtemp data */
 679        for (i = MAX_CORE_DATA - 1; i >= 0; --i) {
 680                if (pdata->core_data[i] &&
 681                        !pdata->core_data[i]->is_pkg_data) {
 682                        return true;
 683                }
 684        }
 685        return false;
 686}
 687
 688static void __cpuinit get_core_online(unsigned int cpu)
 689{
 690        struct cpuinfo_x86 *c = &cpu_data(cpu);
 691        struct platform_device *pdev = coretemp_get_pdev(cpu);
 692        int err;
 693
 694        /*
 695         * CPUID.06H.EAX[0] indicates whether the CPU has thermal
 696         * sensors. We check this bit only, all the early CPUs
 697         * without thermal sensors will be filtered out.
 698         */
 699        if (!cpu_has(c, X86_FEATURE_DTHERM))
 700                return;
 701
 702        if (!pdev) {
 703                /* Check the microcode version of the CPU */
 704                if (chk_ucode_version(cpu))
 705                        return;
 706
 707                /*
 708                 * Alright, we have DTS support.
 709                 * We are bringing the _first_ core in this pkg
 710                 * online. So, initialize per-pkg data structures and
 711                 * then bring this core online.
 712                 */
 713                err = coretemp_device_add(cpu);
 714                if (err)
 715                        return;
 716                /*
 717                 * Check whether pkgtemp support is available.
 718                 * If so, add interfaces for pkgtemp.
 719                 */
 720                if (cpu_has(c, X86_FEATURE_PTS))
 721                        coretemp_add_core(cpu, 1);
 722        }
 723        /*
 724         * Physical CPU device already exists.
 725         * So, just add interfaces for this core.
 726         */
 727        coretemp_add_core(cpu, 0);
 728}
 729
 730static void __cpuinit put_core_offline(unsigned int cpu)
 731{
 732        int i, indx;
 733        struct platform_data *pdata;
 734        struct platform_device *pdev = coretemp_get_pdev(cpu);
 735
 736        /* If the physical CPU device does not exist, just return */
 737        if (!pdev)
 738                return;
 739
 740        pdata = platform_get_drvdata(pdev);
 741
 742        indx = TO_ATTR_NO(cpu);
 743
 744        /* The core id is too big, just return */
 745        if (indx > MAX_CORE_DATA - 1)
 746                return;
 747
 748        if (pdata->core_data[indx] && pdata->core_data[indx]->cpu == cpu)
 749                coretemp_remove_core(pdata, &pdev->dev, indx);
 750
 751        /*
 752         * If a HT sibling of a core is taken offline, but another HT sibling
 753         * of the same core is still online, register the alternate sibling.
 754         * This ensures that exactly one set of attributes is provided as long
 755         * as at least one HT sibling of a core is online.
 756         */
 757        for_each_sibling(i, cpu) {
 758                if (i != cpu) {
 759                        get_core_online(i);
 760                        /*
 761                         * Display temperature sensor data for one HT sibling
 762                         * per core only, so abort the loop after one such
 763                         * sibling has been found.
 764                         */
 765                        break;
 766                }
 767        }
 768        /*
 769         * If all cores in this pkg are offline, remove the device.
 770         * coretemp_device_remove calls unregister_platform_device,
 771         * which in turn calls coretemp_remove. This removes the
 772         * pkgtemp entry and does other clean ups.
 773         */
 774        if (!is_any_core_online(pdata))
 775                coretemp_device_remove(cpu);
 776}
 777
 778static int __cpuinit coretemp_cpu_callback(struct notifier_block *nfb,
 779                                 unsigned long action, void *hcpu)
 780{
 781        unsigned int cpu = (unsigned long) hcpu;
 782
 783        switch (action) {
 784        case CPU_ONLINE:
 785        case CPU_DOWN_FAILED:
 786                get_core_online(cpu);
 787                break;
 788        case CPU_DOWN_PREPARE:
 789                put_core_offline(cpu);
 790                break;
 791        }
 792        return NOTIFY_OK;
 793}
 794
 795static struct notifier_block coretemp_cpu_notifier __refdata = {
 796        .notifier_call = coretemp_cpu_callback,
 797};
 798
 799static const struct x86_cpu_id __initconst coretemp_ids[] = {
 800        { X86_VENDOR_INTEL, X86_FAMILY_ANY, X86_MODEL_ANY, X86_FEATURE_DTHERM },
 801        {}
 802};
 803MODULE_DEVICE_TABLE(x86cpu, coretemp_ids);
 804
 805static int __init coretemp_init(void)
 806{
 807        int i, err;
 808
 809        /*
 810         * CPUID.06H.EAX[0] indicates whether the CPU has thermal
 811         * sensors. We check this bit only, all the early CPUs
 812         * without thermal sensors will be filtered out.
 813         */
 814        if (!x86_match_cpu(coretemp_ids))
 815                return -ENODEV;
 816
 817        err = platform_driver_register(&coretemp_driver);
 818        if (err)
 819                goto exit;
 820
 821        get_online_cpus();
 822        for_each_online_cpu(i)
 823                get_core_online(i);
 824
 825#ifndef CONFIG_HOTPLUG_CPU
 826        if (list_empty(&pdev_list)) {
 827                put_online_cpus();
 828                err = -ENODEV;
 829                goto exit_driver_unreg;
 830        }
 831#endif
 832
 833        register_hotcpu_notifier(&coretemp_cpu_notifier);
 834        put_online_cpus();
 835        return 0;
 836
 837#ifndef CONFIG_HOTPLUG_CPU
 838exit_driver_unreg:
 839        platform_driver_unregister(&coretemp_driver);
 840#endif
 841exit:
 842        return err;
 843}
 844
 845static void __exit coretemp_exit(void)
 846{
 847        struct pdev_entry *p, *n;
 848
 849        get_online_cpus();
 850        unregister_hotcpu_notifier(&coretemp_cpu_notifier);
 851        mutex_lock(&pdev_list_mutex);
 852        list_for_each_entry_safe(p, n, &pdev_list, list) {
 853                platform_device_unregister(p->pdev);
 854                list_del(&p->list);
 855                kfree(p);
 856        }
 857        mutex_unlock(&pdev_list_mutex);
 858        put_online_cpus();
 859        platform_driver_unregister(&coretemp_driver);
 860}
 861
 862MODULE_AUTHOR("Rudolf Marek <r.marek@assembler.cz>");
 863MODULE_DESCRIPTION("Intel Core temperature monitor");
 864MODULE_LICENSE("GPL");
 865
 866module_init(coretemp_init)
 867module_exit(coretemp_exit)
 868
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.