drivers/thermal/x86_pkg_temp_thermal.c

   1 /*
   2  * x86_pkg_temp_thermal driver
   3  * Copyright (c) 2013, Intel Corporation.
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms and conditions of the GNU General Public License,
   7  * version 2, as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along with
  15  * this program; if not, write to the Free Software Foundation, Inc.
  16  *
  17  */
  18 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  19
  20 #include <linux/module.h>
  21 #include <linux/init.h>
  22 #include <linux/err.h>
  23 #include <linux/param.h>
  24 #include <linux/device.h>
  25 #include <linux/platform_device.h>
  26 #include <linux/cpu.h>
  27 #include <linux/smp.h>
  28 #include <linux/slab.h>
  29 #include <linux/pm.h>
  30 #include <linux/thermal.h>
  31 #include <linux/debugfs.h>
  32 #include <asm/cpu_device_id.h>
  33 #include <asm/mce.h>
  34
  35 /*
  36 * Rate control delay: Idea is to introduce denounce effect
  37 * This should be long enough to avoid reduce events, when
  38 * threshold is set to a temperature, which is constantly
  39 * violated, but at the short enough to take any action.
  40 * The action can be remove threshold or change it to next
  41 * interesting setting. Based on experiments, in around
  42 * every 5 seconds under load will give us a significant
  43 * temperature change.
  44 */
  45 #define PKG_TEMP_THERMAL_NOTIFY_DELAY   5000
  46 static int notify_delay_ms = PKG_TEMP_THERMAL_NOTIFY_DELAY;
  47 module_param(notify_delay_ms, int, 0644);
  48 MODULE_PARM_DESC(notify_delay_ms,
  49         "User space notification delay in milli seconds.");
  50
  51 /* Number of trip points in thermal zone. Currently it can't
  52 * be more than 2. MSR can allow setting and getting notifications
  53 * for only 2 thresholds. This define enforces this, if there
  54 * is some wrong values returned by cpuid for number of thresholds.
  55 */
  56 #define MAX_NUMBER_OF_TRIPS     2
  57 /* Limit number of package temp zones */
  58 #define MAX_PKG_TEMP_ZONE_IDS   256
  59
  60 struct phy_dev_entry {
  61         struct list_head list;
  62         u16 phys_proc_id;
  63         u16 first_cpu;
  64         u32 tj_max;
  65         int ref_cnt;
  66         u32 start_pkg_therm_low;
  67         u32 start_pkg_therm_high;
  68         struct thermal_zone_device *tzone;
  69 };
  70
  71 static const struct thermal_zone_params pkg_temp_tz_params = {
  72         .no_hwmon       = true,
  73 };
  74
  75 /* List maintaining number of package instances */
  76 static LIST_HEAD(phy_dev_list);
  77 static DEFINE_MUTEX(phy_dev_list_mutex);
  78
  79 /* Interrupt to work function schedule queue */
  80 static DEFINE_PER_CPU(struct delayed_work, pkg_temp_thermal_threshold_work);
  81
  82 /* To track if the work is already scheduled on a package */
  83 static u8 *pkg_work_scheduled;
  84
  85 /* Spin lock to prevent races with pkg_work_scheduled */
  86 static spinlock_t pkg_work_lock;
  87 static u16 max_phy_id;
  88
  89 /* Debug counters to show using debugfs */
  90 static struct dentry *debugfs;
  91 static unsigned int pkg_interrupt_cnt;
  92 static unsigned int pkg_work_cnt;
  93
  94 static int pkg_temp_debugfs_init(void)
  95 {
  96         struct dentry *d;
  97
  98         debugfs = debugfs_create_dir("pkg_temp_thermal", NULL);
  99         if (!debugfs)
 100                 return -ENOENT;
 101
 102         d = debugfs_create_u32("pkg_thres_interrupt", S_IRUGO, debugfs,
 103                                 (u32 *)&pkg_interrupt_cnt);
 104         if (!d)
 105                 goto err_out;
 106
 107         d = debugfs_create_u32("pkg_thres_work", S_IRUGO, debugfs,
 108                                 (u32 *)&pkg_work_cnt);
 109         if (!d)
 110                 goto err_out;
 111
 112         return 0;
 113
 114 err_out:
 115         debugfs_remove_recursive(debugfs);
 116         return -ENOENT;
 117 }
 118
 119 static struct phy_dev_entry
 120                         *pkg_temp_thermal_get_phy_entry(unsigned int cpu)
 121 {
 122         u16 phys_proc_id = topology_physical_package_id(cpu);
 123         struct phy_dev_entry *phy_ptr;
 124
 125         mutex_lock(&phy_dev_list_mutex);
 126
 127         list_for_each_entry(phy_ptr, &phy_dev_list, list)
 128                 if (phy_ptr->phys_proc_id == phys_proc_id) {
 129                         mutex_unlock(&phy_dev_list_mutex);
 130                         return phy_ptr;
 131                 }
 132
 133         mutex_unlock(&phy_dev_list_mutex);
 134
 135         return NULL;
 136 }
 137
 138 /*
 139 * tj-max is is interesting because threshold is set relative to this
 140 * temperature.
 141 */
 142 static int get_tj_max(int cpu, u32 *tj_max)
 143 {
 144         u32 eax, edx;
 145         u32 val;
 146         int err;
 147
 148         err = rdmsr_safe_on_cpu(cpu, MSR_IA32_TEMPERATURE_TARGET, &eax, &edx);
 149         if (err)
 150                 goto err_ret;
 151         else {
 152                 val = (eax >> 16) & 0xff;
 153                 if (val)
 154                         *tj_max = val * 1000;
 155                 else {
 156                         err = -EINVAL;
 157                         goto err_ret;
 158                 }
 159         }
 160
 161         return 0;
 162 err_ret:
 163         *tj_max = 0;
 164         return err;
 165 }
 166
 167 static int sys_get_curr_temp(struct thermal_zone_device *tzd, unsigned long *temp)
 168 {
 169         u32 eax, edx;
 170         struct phy_dev_entry *phy_dev_entry;
 171
 172         phy_dev_entry = tzd->devdata;
 173         rdmsr_on_cpu(phy_dev_entry->first_cpu, MSR_IA32_PACKAGE_THERM_STATUS,
 174                         &eax, &edx);
 175         if (eax & 0x80000000) {
 176                 *temp = phy_dev_entry->tj_max -
 177                                 ((eax >> 16) & 0x7f) * 1000;
 178                 pr_debug("sys_get_curr_temp %ld\n", *temp);
 179                 return 0;
 180         }
 181
 182         return -EINVAL;
 183 }
 184
 185 static int sys_get_trip_temp(struct thermal_zone_device *tzd,
 186                 int trip, unsigned long *temp)
 187 {
 188         u32 eax, edx;
 189         struct phy_dev_entry *phy_dev_entry;
 190         u32 mask, shift;
 191         unsigned long thres_reg_value;
 192         int ret;
 193
 194         if (trip >= MAX_NUMBER_OF_TRIPS)
 195                 return -EINVAL;
 196
 197         phy_dev_entry = tzd->devdata;
 198
 199         if (trip) {
 200                 mask = THERM_MASK_THRESHOLD1;
 201                 shift = THERM_SHIFT_THRESHOLD1;
 202         } else {
 203                 mask = THERM_MASK_THRESHOLD0;
 204                 shift = THERM_SHIFT_THRESHOLD0;
 205         }
 206
 207         ret = rdmsr_on_cpu(phy_dev_entry->first_cpu,
 208                                 MSR_IA32_PACKAGE_THERM_INTERRUPT, &eax, &edx);
 209         if (ret < 0)
 210                 return -EINVAL;
 211
 212         thres_reg_value = (eax & mask) >> shift;
 213         if (thres_reg_value)
 214                 *temp = phy_dev_entry->tj_max - thres_reg_value * 1000;
 215         else
 216                 *temp = 0;
 217         pr_debug("sys_get_trip_temp %ld\n", *temp);
 218
 219         return 0;
 220 }
 221
 222 static int sys_set_trip_temp(struct thermal_zone_device *tzd, int trip,
 223                                                         unsigned long temp)
 224 {
 225         u32 l, h;
 226         struct phy_dev_entry *phy_dev_entry;
 227         u32 mask, shift, intr;
 228         int ret;
 229
 230         phy_dev_entry = tzd->devdata;
 231
 232         if (trip >= MAX_NUMBER_OF_TRIPS || temp >= phy_dev_entry->tj_max)
 233                 return -EINVAL;
 234
 235         ret = rdmsr_on_cpu(phy_dev_entry->first_cpu,
 236                                         MSR_IA32_PACKAGE_THERM_INTERRUPT,
 237                                         &l, &h);
 238         if (ret < 0)
 239                 return -EINVAL;
 240
 241         if (trip) {
 242                 mask = THERM_MASK_THRESHOLD1;
 243                 shift = THERM_SHIFT_THRESHOLD1;
 244                 intr = THERM_INT_THRESHOLD1_ENABLE;
 245         } else {
 246                 mask = THERM_MASK_THRESHOLD0;
 247                 shift = THERM_SHIFT_THRESHOLD0;
 248                 intr = THERM_INT_THRESHOLD0_ENABLE;
 249         }
 250         l &= ~mask;
 251         /*
 252         * When users space sets a trip temperature == 0, which is indication
 253         * that, it is no longer interested in receiving notifications.
 254         */
 255         if (!temp)
 256                 l &= ~intr;
 257         else {
 258                 l |= (phy_dev_entry->tj_max - temp)/1000 << shift;
 259                 l |= intr;
 260         }
 261
 262         return wrmsr_on_cpu(phy_dev_entry->first_cpu,
 263                                         MSR_IA32_PACKAGE_THERM_INTERRUPT,
 264                                         l, h);
 265 }
 266
 267 static int sys_get_trip_type(struct thermal_zone_device *thermal,
 268                 int trip, enum thermal_trip_type *type)
 269 {
 270
 271         *type = THERMAL_TRIP_PASSIVE;
 272
 273         return 0;
 274 }
 275
 276 /* Thermal zone callback registry */
 277 static struct thermal_zone_device_ops tzone_ops = {
 278         .get_temp = sys_get_curr_temp,
 279         .get_trip_temp = sys_get_trip_temp,
 280         .get_trip_type = sys_get_trip_type,
 281         .set_trip_temp = sys_set_trip_temp,
 282 };
 283
 284 static bool pkg_temp_thermal_platform_thermal_rate_control(void)
 285 {
 286         return true;
 287 }
 288
 289 /* Enable threshold interrupt on local package/cpu */
 290 static inline void enable_pkg_thres_interrupt(void)
 291 {
 292         u32 l, h;
 293         u8 thres_0, thres_1;
 294
 295         rdmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h);
 296         /* only enable/disable if it had valid threshold value */
 297         thres_0 = (l & THERM_MASK_THRESHOLD0) >> THERM_SHIFT_THRESHOLD0;
 298         thres_1 = (l & THERM_MASK_THRESHOLD1) >> THERM_SHIFT_THRESHOLD1;
 299         if (thres_0)
 300                 l |= THERM_INT_THRESHOLD0_ENABLE;
 301         if (thres_1)
 302                 l |= THERM_INT_THRESHOLD1_ENABLE;
 303         wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h);
 304 }
 305
 306 /* Disable threshold interrupt on local package/cpu */
 307 static inline void disable_pkg_thres_interrupt(void)
 308 {
 309         u32 l, h;
 310         rdmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT, l, h);
 311         wrmsr(MSR_IA32_PACKAGE_THERM_INTERRUPT,
 312                         l & (~THERM_INT_THRESHOLD0_ENABLE) &
 313                                 (~THERM_INT_THRESHOLD1_ENABLE), h);
 314 }
 315
 316 static void pkg_temp_thermal_threshold_work_fn(struct work_struct *work)
 317 {
 318         __u64 msr_val;
 319         int cpu = smp_processor_id();
 320         int phy_id = topology_physical_package_id(cpu);
 321         struct phy_dev_entry *phdev = pkg_temp_thermal_get_phy_entry(cpu);
 322         bool notify = false;
 323         unsigned long flags;
 324
 325         if (!phdev)
 326                 return;
 327
 328         spin_lock_irqsave(&pkg_work_lock, flags);
 329         ++pkg_work_cnt;
 330         if (unlikely(phy_id > max_phy_id)) {
 331                 spin_unlock_irqrestore(&pkg_work_lock, flags);
 332                 return;
 333         }
 334         pkg_work_scheduled[phy_id] = 0;
 335         spin_unlock_irqrestore(&pkg_work_lock, flags);
 336
 337         enable_pkg_thres_interrupt();
 338         rdmsrl(MSR_IA32_PACKAGE_THERM_STATUS, msr_val);
 339         if (msr_val & THERM_LOG_THRESHOLD0) {
 340                 wrmsrl(MSR_IA32_PACKAGE_THERM_STATUS,
 341                                 msr_val & ~THERM_LOG_THRESHOLD0);
 342                 notify = true;
 343         }
 344         if (msr_val & THERM_LOG_THRESHOLD1) {
 345                 wrmsrl(MSR_IA32_PACKAGE_THERM_STATUS,
 346                                 msr_val & ~THERM_LOG_THRESHOLD1);
 347                 notify = true;
 348         }
 349         if (notify) {
 350                 pr_debug("thermal_zone_device_update\n");
 351                 thermal_zone_device_update(phdev->tzone);
 352         }
 353 }
 354
 355 static int pkg_temp_thermal_platform_thermal_notify(__u64 msr_val)
 356 {
 357         unsigned long flags;
 358         int cpu = smp_processor_id();
 359         int phy_id = topology_physical_package_id(cpu);
 360
 361         /*
 362         * When a package is in interrupted state, all CPU's in that package
 363         * are in the same interrupt state. So scheduling on any one CPU in
 364         * the package is enough and simply return for others.
 365         */
 366         spin_lock_irqsave(&pkg_work_lock, flags);
 367         ++pkg_interrupt_cnt;
 368         if (unlikely(phy_id > max_phy_id) || unlikely(!pkg_work_scheduled) ||
 369                         pkg_work_scheduled[phy_id]) {
 370                 disable_pkg_thres_interrupt();
 371                 spin_unlock_irqrestore(&pkg_work_lock, flags);
 372                 return -EINVAL;
 373         }
 374         pkg_work_scheduled[phy_id] = 1;
 375         spin_unlock_irqrestore(&pkg_work_lock, flags);
 376
 377         disable_pkg_thres_interrupt();
 378         schedule_delayed_work_on(cpu,
 379                                 &per_cpu(pkg_temp_thermal_threshold_work, cpu),
 380                                 msecs_to_jiffies(notify_delay_ms));
 381         return 0;
 382 }
 383
 384 static int find_siblings_cpu(int cpu)
 385 {
 386         int i;
 387         int id = topology_physical_package_id(cpu);
 388
 389         for_each_online_cpu(i)
 390                 if (i != cpu && topology_physical_package_id(i) == id)
 391                         return i;
 392
 393         return 0;
 394 }
 395
 396 static int pkg_temp_thermal_device_add(unsigned int cpu)
 397 {
 398         int err;
 399         u32 tj_max;
 400         struct phy_dev_entry *phy_dev_entry;
 401         int thres_count;
 402         u32 eax, ebx, ecx, edx;
 403         u8 *temp;
 404         unsigned long flags;
 405
 406         cpuid(6, &eax, &ebx, &ecx, &edx);
 407         thres_count = ebx & 0x07;
 408         if (!thres_count)
 409                 return -ENODEV;
 410
 411         if (topology_physical_package_id(cpu) > MAX_PKG_TEMP_ZONE_IDS)
 412                 return -ENODEV;
 413
 414         thres_count = clamp_val(thres_count, 0, MAX_NUMBER_OF_TRIPS);
 415
 416         err = get_tj_max(cpu, &tj_max);
 417         if (err)
 418                 goto err_ret;
 419
 420         mutex_lock(&phy_dev_list_mutex);
 421
 422         phy_dev_entry = kzalloc(sizeof(*phy_dev_entry), GFP_KERNEL);
 423         if (!phy_dev_entry) {
 424                 err = -ENOMEM;
 425                 goto err_ret_unlock;
 426         }
 427
 428         spin_lock_irqsave(&pkg_work_lock, flags);
 429         if (topology_physical_package_id(cpu) > max_phy_id)
 430                 max_phy_id = topology_physical_package_id(cpu);
 431         temp = krealloc(pkg_work_scheduled,
 432                         (max_phy_id+1) * sizeof(u8), GFP_ATOMIC);
 433         if (!temp) {
 434                 spin_unlock_irqrestore(&pkg_work_lock, flags);
 435                 err = -ENOMEM;
 436                 goto err_ret_free;
 437         }
 438         pkg_work_scheduled = temp;
 439         pkg_work_scheduled[topology_physical_package_id(cpu)] = 0;
 440         spin_unlock_irqrestore(&pkg_work_lock, flags);
 441
 442         phy_dev_entry->phys_proc_id = topology_physical_package_id(cpu);
 443         phy_dev_entry->first_cpu = cpu;
 444         phy_dev_entry->tj_max = tj_max;
 445         phy_dev_entry->ref_cnt = 1;
 446         phy_dev_entry->tzone = thermal_zone_device_register("x86_pkg_temp",
 447                         thres_count,
 448                         (thres_count == MAX_NUMBER_OF_TRIPS) ?
 449                                 0x03 : 0x01,
 450                         phy_dev_entry, &tzone_ops, &pkg_temp_tz_params, 0, 0);
 451         if (IS_ERR(phy_dev_entry->tzone)) {
 452                 err = PTR_ERR(phy_dev_entry->tzone);
 453                 goto err_ret_free;
 454         }
 455         /* Store MSR value for package thermal interrupt, to restore at exit */
 456         rdmsr_on_cpu(cpu, MSR_IA32_PACKAGE_THERM_INTERRUPT,
 457                                 &phy_dev_entry->start_pkg_therm_low,
 458                                 &phy_dev_entry->start_pkg_therm_high);
 459
 460         list_add_tail(&phy_dev_entry->list, &phy_dev_list);
 461         pr_debug("pkg_temp_thermal_device_add :phy_id %d cpu %d\n",
 462                         phy_dev_entry->phys_proc_id, cpu);
 463
 464         mutex_unlock(&phy_dev_list_mutex);
 465
 466         return 0;
 467
 468 err_ret_free:
 469         kfree(phy_dev_entry);
 470 err_ret_unlock:
 471         mutex_unlock(&phy_dev_list_mutex);
 472
 473 err_ret:
 474         return err;
 475 }
 476
 477 static int pkg_temp_thermal_device_remove(unsigned int cpu)
 478 {
 479         struct phy_dev_entry *n;
 480         u16 phys_proc_id = topology_physical_package_id(cpu);
 481         struct phy_dev_entry *phdev =
 482                         pkg_temp_thermal_get_phy_entry(cpu);
 483
 484         if (!phdev)
 485                 return -ENODEV;
 486
 487         mutex_lock(&phy_dev_list_mutex);
 488         /* If we are loosing the first cpu for this package, we need change */
 489         if (phdev->first_cpu == cpu) {
 490                 phdev->first_cpu = find_siblings_cpu(cpu);
 491                 pr_debug("thermal_device_remove: first cpu switched %d\n",
 492                                         phdev->first_cpu);
 493         }
 494         /*
 495         * It is possible that no siblings left as this was the last cpu
 496         * going offline. We don't need to worry about this assignment
 497         * as the phydev entry will be removed in this case and
 498         * thermal zone is removed.
 499         */
 500         --phdev->ref_cnt;
 501         pr_debug("thermal_device_remove: pkg: %d cpu %d ref_cnt %d\n",
 502                                         phys_proc_id, cpu, phdev->ref_cnt);
 503         if (!phdev->ref_cnt)
 504                 list_for_each_entry_safe(phdev, n, &phy_dev_list, list) {
 505                         if (phdev->phys_proc_id == phys_proc_id) {
 506                                 thermal_zone_device_unregister(phdev->tzone);
 507                                 list_del(&phdev->list);
 508                                 kfree(phdev);
 509                                 break;
 510                         }
 511                 }
 512         mutex_unlock(&phy_dev_list_mutex);
 513
 514         return 0;
 515 }
 516
 517 static int get_core_online(unsigned int cpu)
 518 {
 519         struct cpuinfo_x86 *c = &cpu_data(cpu);
 520         struct phy_dev_entry *phdev = pkg_temp_thermal_get_phy_entry(cpu);
 521
 522         /* Check if there is already an instance for this package */
 523         if (!phdev) {
 524                 if (!cpu_has(c, X86_FEATURE_DTHERM) ||
 525                                         !cpu_has(c, X86_FEATURE_PTS))
 526                         return -ENODEV;
 527                 if (pkg_temp_thermal_device_add(cpu))
 528                         return -ENODEV;
 529         } else {
 530                 mutex_lock(&phy_dev_list_mutex);
 531                 ++phdev->ref_cnt;
 532                 pr_debug("get_core_online: cpu %d ref_cnt %d\n",
 533                                                 cpu, phdev->ref_cnt);
 534                 mutex_unlock(&phy_dev_list_mutex);
 535         }
 536         INIT_DELAYED_WORK(&per_cpu(pkg_temp_thermal_threshold_work, cpu),
 537                         pkg_temp_thermal_threshold_work_fn);
 538
 539         pr_debug("get_core_online: cpu %d successful\n", cpu);
 540
 541         return 0;
 542 }
 543
 544 static void put_core_offline(unsigned int cpu)
 545 {
 546         if (!pkg_temp_thermal_device_remove(cpu))
 547                 cancel_delayed_work_sync(
 548                         &per_cpu(pkg_temp_thermal_threshold_work, cpu));
 549
 550         pr_debug("put_core_offline: cpu %d\n", cpu);
 551 }
 552
 553 static int pkg_temp_thermal_cpu_callback(struct notifier_block *nfb,
 554                                  unsigned long action, void *hcpu)
 555 {
 556         unsigned int cpu = (unsigned long) hcpu;
 557
 558         switch (action) {
 559         case CPU_ONLINE:
 560         case CPU_DOWN_FAILED:
 561                 get_core_online(cpu);
 562                 break;
 563         case CPU_DOWN_PREPARE:
 564                 put_core_offline(cpu);
 565                 break;
 566         }
 567         return NOTIFY_OK;
 568 }
 569
 570 static struct notifier_block pkg_temp_thermal_notifier __refdata = {
 571         .notifier_call = pkg_temp_thermal_cpu_callback,
 572 };
 573
 574 static const struct x86_cpu_id __initconst pkg_temp_thermal_ids[] = {
 575         { X86_VENDOR_INTEL, X86_FAMILY_ANY, X86_MODEL_ANY, X86_FEATURE_PTS },
 576         {}
 577 };
 578 MODULE_DEVICE_TABLE(x86cpu, pkg_temp_thermal_ids);
 579
 580 static int __init pkg_temp_thermal_init(void)
 581 {
 582         int i;
 583
 584         if (!x86_match_cpu(pkg_temp_thermal_ids))
 585                 return -ENODEV;
 586
 587         spin_lock_init(&pkg_work_lock);
 588         platform_thermal_package_notify =
 589                         pkg_temp_thermal_platform_thermal_notify;
 590         platform_thermal_package_rate_control =
 591                         pkg_temp_thermal_platform_thermal_rate_control;
 592
 593         cpu_notifier_register_begin();
 594         for_each_online_cpu(i)
 595                 if (get_core_online(i))
 596                         goto err_ret;
 597         __register_hotcpu_notifier(&pkg_temp_thermal_notifier);
 598         cpu_notifier_register_done();
 599
 600         pkg_temp_debugfs_init(); /* Don't care if fails */
 601
 602         return 0;
 603
 604 err_ret:
 605         for_each_online_cpu(i)
 606                 put_core_offline(i);
 607         cpu_notifier_register_done();
 608         kfree(pkg_work_scheduled);
 609         platform_thermal_package_notify = NULL;
 610         platform_thermal_package_rate_control = NULL;
 611
 612         return -ENODEV;
 613 }
 614
 615 static void __exit pkg_temp_thermal_exit(void)
 616 {
 617         struct phy_dev_entry *phdev, *n;
 618         int i;
 619
 620         cpu_notifier_register_begin();
 621         __unregister_hotcpu_notifier(&pkg_temp_thermal_notifier);
 622         mutex_lock(&phy_dev_list_mutex);
 623         list_for_each_entry_safe(phdev, n, &phy_dev_list, list) {
 624                 /* Retore old MSR value for package thermal interrupt */
 625                 wrmsr_on_cpu(phdev->first_cpu,
 626                         MSR_IA32_PACKAGE_THERM_INTERRUPT,
 627                         phdev->start_pkg_therm_low,
 628                         phdev->start_pkg_therm_high);
 629                 thermal_zone_device_unregister(phdev->tzone);
 630                 list_del(&phdev->list);
 631                 kfree(phdev);
 632         }
 633         mutex_unlock(&phy_dev_list_mutex);
 634         platform_thermal_package_notify = NULL;
 635         platform_thermal_package_rate_control = NULL;
 636         for_each_online_cpu(i)
 637                 cancel_delayed_work_sync(
 638                         &per_cpu(pkg_temp_thermal_threshold_work, i));
 639         cpu_notifier_register_done();
 640
 641         kfree(pkg_work_scheduled);
 642
 643         debugfs_remove_recursive(debugfs);
 644 }
 645
 646 module_init(pkg_temp_thermal_init)
 647 module_exit(pkg_temp_thermal_exit)
 648
 649 MODULE_DESCRIPTION("X86 PKG TEMP Thermal Driver");
 650 MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
 651 MODULE_LICENSE("GPL v2");