drivers/acpi/acpi_processor.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * acpi_processor.c - ACPI processor enumeration support
   4  *
   5  * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   6  * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   7  * Copyright (C) 2004       Dominik Brodowski <linux@brodo.de>
   8  * Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
   9  * Copyright (C) 2013, Intel Corporation
  10  *                     Rafael J. Wysocki <rafael.j.wysocki@intel.com>
  11  */
  12
  13 #include <linux/acpi.h>
  14 #include <linux/device.h>
  15 #include <linux/kernel.h>
  16 #include <linux/module.h>
  17 #include <linux/pci.h>
  18
  19 #include <acpi/processor.h>
  20
  21 #include <asm/cpu.h>
  22
  23 #include "internal.h"
  24
  25 #define _COMPONENT      ACPI_PROCESSOR_COMPONENT
  26
  27 ACPI_MODULE_NAME("processor");
  28
  29 DEFINE_PER_CPU(struct acpi_processor *, processors);
  30 EXPORT_PER_CPU_SYMBOL(processors);
  31
  32 /* --------------------------------------------------------------------------
  33                                 Errata Handling
  34    -------------------------------------------------------------------------- */
  35
  36 struct acpi_processor_errata errata __read_mostly;
  37 EXPORT_SYMBOL_GPL(errata);
  38
  39 static int acpi_processor_errata_piix4(struct pci_dev *dev)
  40 {
  41         u8 value1 = 0;
  42         u8 value2 = 0;
  43
  44
  45         if (!dev)
  46                 return -EINVAL;
  47
  48         /*
  49          * Note that 'dev' references the PIIX4 ACPI Controller.
  50          */
  51
  52         switch (dev->revision) {
  53         case 0:
  54                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4 A-step\n"));
  55                 break;
  56         case 1:
  57                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4 B-step\n"));
  58                 break;
  59         case 2:
  60                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4E\n"));
  61                 break;
  62         case 3:
  63                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4M\n"));
  64                 break;
  65         default:
  66                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found unknown PIIX4\n"));
  67                 break;
  68         }
  69
  70         switch (dev->revision) {
  71
  72         case 0:         /* PIIX4 A-step */
  73         case 1:         /* PIIX4 B-step */
  74                 /*
  75                  * See specification changes #13 ("Manual Throttle Duty Cycle")
  76                  * and #14 ("Enabling and Disabling Manual Throttle"), plus
  77                  * erratum #5 ("STPCLK# Deassertion Time") from the January
  78                  * 2002 PIIX4 specification update.  Applies to only older
  79                  * PIIX4 models.
  80                  */
  81                 errata.piix4.throttle = 1;
  82                 /* fall through*/
  83
  84         case 2:         /* PIIX4E */
  85         case 3:         /* PIIX4M */
  86                 /*
  87                  * See erratum #18 ("C3 Power State/BMIDE and Type-F DMA
  88                  * Livelock") from the January 2002 PIIX4 specification update.
  89                  * Applies to all PIIX4 models.
  90                  */
  91
  92                 /*
  93                  * BM-IDE
  94                  * ------
  95                  * Find the PIIX4 IDE Controller and get the Bus Master IDE
  96                  * Status register address.  We'll use this later to read
  97                  * each IDE controller's DMA status to make sure we catch all
  98                  * DMA activity.
  99                  */
 100                 dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
 101                                      PCI_DEVICE_ID_INTEL_82371AB,
 102                                      PCI_ANY_ID, PCI_ANY_ID, NULL);
 103                 if (dev) {
 104                         errata.piix4.bmisx = pci_resource_start(dev, 4);
 105                         pci_dev_put(dev);
 106                 }
 107
 108                 /*
 109                  * Type-F DMA
 110                  * ----------
 111                  * Find the PIIX4 ISA Controller and read the Motherboard
 112                  * DMA controller's status to see if Type-F (Fast) DMA mode
 113                  * is enabled (bit 7) on either channel.  Note that we'll
 114                  * disable C3 support if this is enabled, as some legacy
 115                  * devices won't operate well if fast DMA is disabled.
 116                  */
 117                 dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
 118                                      PCI_DEVICE_ID_INTEL_82371AB_0,
 119                                      PCI_ANY_ID, PCI_ANY_ID, NULL);
 120                 if (dev) {
 121                         pci_read_config_byte(dev, 0x76, &value1);
 122                         pci_read_config_byte(dev, 0x77, &value2);
 123                         if ((value1 & 0x80) || (value2 & 0x80))
 124                                 errata.piix4.fdma = 1;
 125                         pci_dev_put(dev);
 126                 }
 127
 128                 break;
 129         }
 130
 131         if (errata.piix4.bmisx)
 132                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 133                                   "Bus master activity detection (BM-IDE) erratum enabled\n"));
 134         if (errata.piix4.fdma)
 135                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 136                                   "Type-F DMA livelock erratum (C3 disabled)\n"));
 137
 138         return 0;
 139 }
 140
 141 static int acpi_processor_errata(void)
 142 {
 143         int result = 0;
 144         struct pci_dev *dev = NULL;
 145
 146         /*
 147          * PIIX4
 148          */
 149         dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
 150                              PCI_DEVICE_ID_INTEL_82371AB_3, PCI_ANY_ID,
 151                              PCI_ANY_ID, NULL);
 152         if (dev) {
 153                 result = acpi_processor_errata_piix4(dev);
 154                 pci_dev_put(dev);
 155         }
 156
 157         return result;
 158 }
 159
 160 /* --------------------------------------------------------------------------
 161                                 Initialization
 162    -------------------------------------------------------------------------- */
 163
 164 #ifdef CONFIG_ACPI_HOTPLUG_CPU
 165 int __weak acpi_map_cpu(acpi_handle handle,
 166                 phys_cpuid_t physid, u32 acpi_id, int *pcpu)
 167 {
 168         return -ENODEV;
 169 }
 170
 171 int __weak acpi_unmap_cpu(int cpu)
 172 {
 173         return -ENODEV;
 174 }
 175
 176 int __weak arch_register_cpu(int cpu)
 177 {
 178         return -ENODEV;
 179 }
 180
 181 void __weak arch_unregister_cpu(int cpu) {}
 182
 183 static int acpi_processor_hotadd_init(struct acpi_processor *pr)
 184 {
 185         unsigned long long sta;
 186         acpi_status status;
 187         int ret;
 188
 189         if (invalid_phys_cpuid(pr->phys_id))
 190                 return -ENODEV;
 191
 192         status = acpi_evaluate_integer(pr->handle, "_STA", NULL, &sta);
 193         if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_PRESENT))
 194                 return -ENODEV;
 195
 196         cpu_maps_update_begin();
 197         cpu_hotplug_begin();
 198
 199         ret = acpi_map_cpu(pr->handle, pr->phys_id, pr->acpi_id, &pr->id);
 200         if (ret)
 201                 goto out;
 202
 203         ret = arch_register_cpu(pr->id);
 204         if (ret) {
 205                 acpi_unmap_cpu(pr->id);
 206                 goto out;
 207         }
 208
 209         /*
 210          * CPU got hot-added, but cpu_data is not initialized yet.  Set a flag
 211          * to delay cpu_idle/throttling initialization and do it when the CPU
 212          * gets online for the first time.
 213          */
 214         pr_info("CPU%d has been hot-added\n", pr->id);
 215         pr->flags.need_hotplug_init = 1;
 216
 217 out:
 218         cpu_hotplug_done();
 219         cpu_maps_update_done();
 220         return ret;
 221 }
 222 #else
 223 static inline int acpi_processor_hotadd_init(struct acpi_processor *pr)
 224 {
 225         return -ENODEV;
 226 }
 227 #endif /* CONFIG_ACPI_HOTPLUG_CPU */
 228
 229 static int acpi_processor_get_info(struct acpi_device *device)
 230 {
 231         union acpi_object object = { 0 };
 232         struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
 233         struct acpi_processor *pr = acpi_driver_data(device);
 234         int device_declaration = 0;
 235         acpi_status status = AE_OK;
 236         static int cpu0_initialized;
 237         unsigned long long value;
 238
 239         acpi_processor_errata();
 240
 241         /*
 242          * Check to see if we have bus mastering arbitration control.  This
 243          * is required for proper C3 usage (to maintain cache coherency).
 244          */
 245         if (acpi_gbl_FADT.pm2_control_block && acpi_gbl_FADT.pm2_control_length) {
 246                 pr->flags.bm_control = 1;
 247                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 248                                   "Bus mastering arbitration control present\n"));
 249         } else
 250                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 251                                   "No bus mastering arbitration control\n"));
 252
 253         if (!strcmp(acpi_device_hid(device), ACPI_PROCESSOR_OBJECT_HID)) {
 254                 /* Declared with "Processor" statement; match ProcessorID */
 255                 status = acpi_evaluate_object(pr->handle, NULL, NULL, &buffer);
 256                 if (ACPI_FAILURE(status)) {
 257                         dev_err(&device->dev,
 258                                 "Failed to evaluate processor object (0x%x)\n",
 259                                 status);
 260                         return -ENODEV;
 261                 }
 262
 263                 pr->acpi_id = object.processor.proc_id;
 264         } else {
 265                 /*
 266                  * Declared with "Device" statement; match _UID.
 267                  * Note that we don't handle string _UIDs yet.
 268                  */
 269                 status = acpi_evaluate_integer(pr->handle, METHOD_NAME__UID,
 270                                                 NULL, &value);
 271                 if (ACPI_FAILURE(status)) {
 272                         dev_err(&device->dev,
 273                                 "Failed to evaluate processor _UID (0x%x)\n",
 274                                 status);
 275                         return -ENODEV;
 276                 }
 277                 device_declaration = 1;
 278                 pr->acpi_id = value;
 279         }
 280
 281         if (acpi_duplicate_processor_id(pr->acpi_id)) {
 282                 dev_err(&device->dev,
 283                         "Failed to get unique processor _UID (0x%x)\n",
 284                         pr->acpi_id);
 285                 return -ENODEV;
 286         }
 287
 288         pr->phys_id = acpi_get_phys_id(pr->handle, device_declaration,
 289                                         pr->acpi_id);
 290         if (invalid_phys_cpuid(pr->phys_id))
 291                 acpi_handle_debug(pr->handle, "failed to get CPU physical ID.\n");
 292
 293         pr->id = acpi_map_cpuid(pr->phys_id, pr->acpi_id);
 294         if (!cpu0_initialized && !acpi_has_cpu_in_madt()) {
 295                 cpu0_initialized = 1;
 296                 /*
 297                  * Handle UP system running SMP kernel, with no CPU
 298                  * entry in MADT
 299                  */
 300                 if (invalid_logical_cpuid(pr->id) && (num_online_cpus() == 1))
 301                         pr->id = 0;
 302         }
 303
 304         /*
 305          *  Extra Processor objects may be enumerated on MP systems with
 306          *  less than the max # of CPUs. They should be ignored _iff
 307          *  they are physically not present.
 308          *
 309          *  NOTE: Even if the processor has a cpuid, it may not be present
 310          *  because cpuid <-> apicid mapping is persistent now.
 311          */
 312         if (invalid_logical_cpuid(pr->id) || !cpu_present(pr->id)) {
 313                 int ret = acpi_processor_hotadd_init(pr);
 314                 if (ret)
 315                         return ret;
 316         }
 317
 318         /*
 319          * On some boxes several processors use the same processor bus id.
 320          * But they are located in different scope. For example:
 321          * \_SB.SCK0.CPU0
 322          * \_SB.SCK1.CPU0
 323          * Rename the processor device bus id. And the new bus id will be
 324          * generated as the following format:
 325          * CPU+CPU ID.
 326          */
 327         sprintf(acpi_device_bid(device), "CPU%X", pr->id);
 328         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Processor [%d:%d]\n", pr->id,
 329                           pr->acpi_id));
 330
 331         if (!object.processor.pblk_address)
 332                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No PBLK (NULL address)\n"));
 333         else if (object.processor.pblk_length != 6)
 334                 dev_err(&device->dev, "Invalid PBLK length [%d]\n",
 335                             object.processor.pblk_length);
 336         else {
 337                 pr->throttling.address = object.processor.pblk_address;
 338                 pr->throttling.duty_offset = acpi_gbl_FADT.duty_offset;
 339                 pr->throttling.duty_width = acpi_gbl_FADT.duty_width;
 340
 341                 pr->pblk = object.processor.pblk_address;
 342         }
 343
 344         /*
 345          * If ACPI describes a slot number for this CPU, we can use it to
 346          * ensure we get the right value in the "physical id" field
 347          * of /proc/cpuinfo
 348          */
 349         status = acpi_evaluate_integer(pr->handle, "_SUN", NULL, &value);
 350         if (ACPI_SUCCESS(status))
 351                 arch_fix_phys_package_id(pr->id, value);
 352
 353         return 0;
 354 }
 355
 356 /*
 357  * Do not put anything in here which needs the core to be online.
 358  * For example MSR access or setting up things which check for cpuinfo_x86
 359  * (cpu_data(cpu)) values, like CPU feature flags, family, model, etc.
 360  * Such things have to be put in and set up by the processor driver's .probe().
 361  */
 362 static DEFINE_PER_CPU(void *, processor_device_array);
 363
 364 static int acpi_processor_add(struct acpi_device *device,
 365                                         const struct acpi_device_id *id)
 366 {
 367         struct acpi_processor *pr;
 368         struct device *dev;
 369         int result = 0;
 370
 371         pr = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL);
 372         if (!pr)
 373                 return -ENOMEM;
 374
 375         if (!zalloc_cpumask_var(&pr->throttling.shared_cpu_map, GFP_KERNEL)) {
 376                 result = -ENOMEM;
 377                 goto err_free_pr;
 378         }
 379
 380         pr->handle = device->handle;
 381         strcpy(acpi_device_name(device), ACPI_PROCESSOR_DEVICE_NAME);
 382         strcpy(acpi_device_class(device), ACPI_PROCESSOR_CLASS);
 383         device->driver_data = pr;
 384
 385         result = acpi_processor_get_info(device);
 386         if (result) /* Processor is not physically present or unavailable */
 387                 return 0;
 388
 389         BUG_ON(pr->id >= nr_cpu_ids);
 390
 391         /*
 392          * Buggy BIOS check.
 393          * ACPI id of processors can be reported wrongly by the BIOS.
 394          * Don't trust it blindly
 395          */
 396         if (per_cpu(processor_device_array, pr->id) != NULL &&
 397             per_cpu(processor_device_array, pr->id) != device) {
 398                 dev_warn(&device->dev,
 399                         "BIOS reported wrong ACPI id %d for the processor\n",
 400                         pr->id);
 401                 /* Give up, but do not abort the namespace scan. */
 402                 goto err;
 403         }
 404         /*
 405          * processor_device_array is not cleared on errors to allow buggy BIOS
 406          * checks.
 407          */
 408         per_cpu(processor_device_array, pr->id) = device;
 409         per_cpu(processors, pr->id) = pr;
 410
 411         dev = get_cpu_device(pr->id);
 412         if (!dev) {
 413                 result = -ENODEV;
 414                 goto err;
 415         }
 416
 417         result = acpi_bind_one(dev, device);
 418         if (result)
 419                 goto err;
 420
 421         pr->dev = dev;
 422
 423         /* Trigger the processor driver's .probe() if present. */
 424         if (device_attach(dev) >= 0)
 425                 return 1;
 426
 427         dev_err(dev, "Processor driver could not be attached\n");
 428         acpi_unbind_one(dev);
 429
 430  err:
 431         free_cpumask_var(pr->throttling.shared_cpu_map);
 432         device->driver_data = NULL;
 433         per_cpu(processors, pr->id) = NULL;
 434  err_free_pr:
 435         kfree(pr);
 436         return result;
 437 }
 438
 439 #ifdef CONFIG_ACPI_HOTPLUG_CPU
 440 /* --------------------------------------------------------------------------
 441                                     Removal
 442    -------------------------------------------------------------------------- */
 443
 444 static void acpi_processor_remove(struct acpi_device *device)
 445 {
 446         struct acpi_processor *pr;
 447
 448         if (!device || !acpi_driver_data(device))
 449                 return;
 450
 451         pr = acpi_driver_data(device);
 452         if (pr->id >= nr_cpu_ids)
 453                 goto out;
 454
 455         /*
 456          * The only reason why we ever get here is CPU hot-removal.  The CPU is
 457          * already offline and the ACPI device removal locking prevents it from
 458          * being put back online at this point.
 459          *
 460          * Unbind the driver from the processor device and detach it from the
 461          * ACPI companion object.
 462          */
 463         device_release_driver(pr->dev);
 464         acpi_unbind_one(pr->dev);
 465
 466         /* Clean up. */
 467         per_cpu(processor_device_array, pr->id) = NULL;
 468         per_cpu(processors, pr->id) = NULL;
 469
 470         cpu_maps_update_begin();
 471         cpu_hotplug_begin();
 472
 473         /* Remove the CPU. */
 474         arch_unregister_cpu(pr->id);
 475         acpi_unmap_cpu(pr->id);
 476
 477         cpu_hotplug_done();
 478         cpu_maps_update_done();
 479
 480         try_offline_node(cpu_to_node(pr->id));
 481
 482  out:
 483         free_cpumask_var(pr->throttling.shared_cpu_map);
 484         kfree(pr);
 485 }
 486 #endif /* CONFIG_ACPI_HOTPLUG_CPU */
 487
 488 #ifdef CONFIG_X86
 489 static bool acpi_hwp_native_thermal_lvt_set;
 490 static acpi_status __init acpi_hwp_native_thermal_lvt_osc(acpi_handle handle,
 491                                                           u32 lvl,
 492                                                           void *context,
 493                                                           void **rv)
 494 {
 495         u8 sb_uuid_str[] = "4077A616-290C-47BE-9EBD-D87058713953";
 496         u32 capbuf[2];
 497         struct acpi_osc_context osc_context = {
 498                 .uuid_str = sb_uuid_str,
 499                 .rev = 1,
 500                 .cap.length = 8,
 501                 .cap.pointer = capbuf,
 502         };
 503
 504         if (acpi_hwp_native_thermal_lvt_set)
 505                 return AE_CTRL_TERMINATE;
 506
 507         capbuf[0] = 0x0000;
 508         capbuf[1] = 0x1000; /* set bit 12 */
 509
 510         if (ACPI_SUCCESS(acpi_run_osc(handle, &osc_context))) {
 511                 if (osc_context.ret.pointer && osc_context.ret.length > 1) {
 512                         u32 *capbuf_ret = osc_context.ret.pointer;
 513
 514                         if (capbuf_ret[1] & 0x1000) {
 515                                 acpi_handle_info(handle,
 516                                         "_OSC native thermal LVT Acked\n");
 517                                 acpi_hwp_native_thermal_lvt_set = true;
 518                         }
 519                 }
 520                 kfree(osc_context.ret.pointer);
 521         }
 522
 523         return AE_OK;
 524 }
 525
 526 void __init acpi_early_processor_osc(void)
 527 {
 528         if (boot_cpu_has(X86_FEATURE_HWP)) {
 529                 acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
 530                                     ACPI_UINT32_MAX,
 531                                     acpi_hwp_native_thermal_lvt_osc,
 532                                     NULL, NULL, NULL);
 533                 acpi_get_devices(ACPI_PROCESSOR_DEVICE_HID,
 534                                  acpi_hwp_native_thermal_lvt_osc,
 535                                  NULL, NULL);
 536         }
 537 }
 538 #endif
 539
 540 /*
 541  * The following ACPI IDs are known to be suitable for representing as
 542  * processor devices.
 543  */
 544 static const struct acpi_device_id processor_device_ids[] = {
 545
 546         { ACPI_PROCESSOR_OBJECT_HID, },
 547         { ACPI_PROCESSOR_DEVICE_HID, },
 548
 549         { }
 550 };
 551
 552 static struct acpi_scan_handler processor_handler = {
 553         .ids = processor_device_ids,
 554         .attach = acpi_processor_add,
 555 #ifdef CONFIG_ACPI_HOTPLUG_CPU
 556         .detach = acpi_processor_remove,
 557 #endif
 558         .hotplug = {
 559                 .enabled = true,
 560         },
 561 };
 562
 563 static int acpi_processor_container_attach(struct acpi_device *dev,
 564                                            const struct acpi_device_id *id)
 565 {
 566         return 1;
 567 }
 568
 569 static const struct acpi_device_id processor_container_ids[] = {
 570         { ACPI_PROCESSOR_CONTAINER_HID, },
 571         { }
 572 };
 573
 574 static struct acpi_scan_handler processor_container_handler = {
 575         .ids = processor_container_ids,
 576         .attach = acpi_processor_container_attach,
 577 };
 578
 579 /* The number of the unique processor IDs */
 580 static int nr_unique_ids __initdata;
 581
 582 /* The number of the duplicate processor IDs */
 583 static int nr_duplicate_ids;
 584
 585 /* Used to store the unique processor IDs */
 586 static int unique_processor_ids[] __initdata = {
 587         [0 ... NR_CPUS - 1] = -1,
 588 };
 589
 590 /* Used to store the duplicate processor IDs */
 591 static int duplicate_processor_ids[] = {
 592         [0 ... NR_CPUS - 1] = -1,
 593 };
 594
 595 static void __init processor_validated_ids_update(int proc_id)
 596 {
 597         int i;
 598
 599         if (nr_unique_ids == NR_CPUS||nr_duplicate_ids == NR_CPUS)
 600                 return;
 601
 602         /*
 603          * Firstly, compare the proc_id with duplicate IDs, if the proc_id is
 604          * already in the IDs, do nothing.
 605          */
 606         for (i = 0; i < nr_duplicate_ids; i++) {
 607                 if (duplicate_processor_ids[i] == proc_id)
 608                         return;
 609         }
 610
 611         /*
 612          * Secondly, compare the proc_id with unique IDs, if the proc_id is in
 613          * the IDs, put it in the duplicate IDs.
 614          */
 615         for (i = 0; i < nr_unique_ids; i++) {
 616                 if (unique_processor_ids[i] == proc_id) {
 617                         duplicate_processor_ids[nr_duplicate_ids] = proc_id;
 618                         nr_duplicate_ids++;
 619                         return;
 620                 }
 621         }
 622
 623         /*
 624          * Lastly, the proc_id is a unique ID, put it in the unique IDs.
 625          */
 626         unique_processor_ids[nr_unique_ids] = proc_id;
 627         nr_unique_ids++;
 628 }
 629
 630 static acpi_status __init acpi_processor_ids_walk(acpi_handle handle,
 631                                                   u32 lvl,
 632                                                   void *context,
 633                                                   void **rv)
 634 {
 635         acpi_status status;
 636         acpi_object_type acpi_type;
 637         unsigned long long uid;
 638         union acpi_object object = { 0 };
 639         struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
 640
 641         status = acpi_get_type(handle, &acpi_type);
 642         if (ACPI_FAILURE(status))
 643                 return status;
 644
 645         switch (acpi_type) {
 646         case ACPI_TYPE_PROCESSOR:
 647                 status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
 648                 if (ACPI_FAILURE(status))
 649                         goto err;
 650                 uid = object.processor.proc_id;
 651                 break;
 652
 653         case ACPI_TYPE_DEVICE:
 654                 status = acpi_evaluate_integer(handle, "_UID", NULL, &uid);
 655                 if (ACPI_FAILURE(status))
 656                         goto err;
 657                 break;
 658         default:
 659                 goto err;
 660         }
 661
 662         processor_validated_ids_update(uid);
 663         return AE_OK;
 664
 665 err:
 666         /* Exit on error, but don't abort the namespace walk */
 667         acpi_handle_info(handle, "Invalid processor object\n");
 668         return AE_OK;
 669
 670 }
 671
 672 static void __init acpi_processor_check_duplicates(void)
 673 {
 674         /* check the correctness for all processors in ACPI namespace */
 675         acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
 676                                                 ACPI_UINT32_MAX,
 677                                                 acpi_processor_ids_walk,
 678                                                 NULL, NULL, NULL);
 679         acpi_get_devices(ACPI_PROCESSOR_DEVICE_HID, acpi_processor_ids_walk,
 680                                                 NULL, NULL);
 681 }
 682
 683 bool acpi_duplicate_processor_id(int proc_id)
 684 {
 685         int i;
 686
 687         /*
 688          * compare the proc_id with duplicate IDs, if the proc_id is already
 689          * in the duplicate IDs, return true, otherwise, return false.
 690          */
 691         for (i = 0; i < nr_duplicate_ids; i++) {
 692                 if (duplicate_processor_ids[i] == proc_id)
 693                         return true;
 694         }
 695         return false;
 696 }
 697
 698 void __init acpi_processor_init(void)
 699 {
 700         acpi_processor_check_duplicates();
 701         acpi_scan_add_handler_with_hotplug(&processor_handler, "processor");
 702         acpi_scan_add_handler(&processor_container_handler);
 703 }