drivers/acpi/acpi_processor.c

   1 /*
   2  * acpi_processor.c - ACPI processor enumeration support
   3  *
   4  * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   5  * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   6  * Copyright (C) 2004       Dominik Brodowski <linux@brodo.de>
   7  * Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
   8  * Copyright (C) 2013, Intel Corporation
   9  *                     Rafael J. Wysocki <rafael.j.wysocki@intel.com>
  10  *
  11  * This program is free software; you can redistribute it and/or modify it
  12  * under the terms of the GNU General Public License version 2 as published
  13  * by the Free Software Foundation.
  14  */
  15
  16 #include <linux/acpi.h>
  17 #include <linux/device.h>
  18 #include <linux/kernel.h>
  19 #include <linux/module.h>
  20 #include <linux/pci.h>
  21
  22 #include <acpi/processor.h>
  23
  24 #include <asm/cpu.h>
  25
  26 #include "internal.h"
  27
  28 #define _COMPONENT      ACPI_PROCESSOR_COMPONENT
  29
  30 ACPI_MODULE_NAME("processor");
  31
  32 DEFINE_PER_CPU(struct acpi_processor *, processors);
  33 EXPORT_PER_CPU_SYMBOL(processors);
  34
  35 /* --------------------------------------------------------------------------
  36                                 Errata Handling
  37    -------------------------------------------------------------------------- */
  38
  39 struct acpi_processor_errata errata __read_mostly;
  40 EXPORT_SYMBOL_GPL(errata);
  41
  42 static int acpi_processor_errata_piix4(struct pci_dev *dev)
  43 {
  44         u8 value1 = 0;
  45         u8 value2 = 0;
  46
  47
  48         if (!dev)
  49                 return -EINVAL;
  50
  51         /*
  52          * Note that 'dev' references the PIIX4 ACPI Controller.
  53          */
  54
  55         switch (dev->revision) {
  56         case 0:
  57                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4 A-step\n"));
  58                 break;
  59         case 1:
  60                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4 B-step\n"));
  61                 break;
  62         case 2:
  63                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4E\n"));
  64                 break;
  65         case 3:
  66                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4M\n"));
  67                 break;
  68         default:
  69                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found unknown PIIX4\n"));
  70                 break;
  71         }
  72
  73         switch (dev->revision) {
  74
  75         case 0:         /* PIIX4 A-step */
  76         case 1:         /* PIIX4 B-step */
  77                 /*
  78                  * See specification changes #13 ("Manual Throttle Duty Cycle")
  79                  * and #14 ("Enabling and Disabling Manual Throttle"), plus
  80                  * erratum #5 ("STPCLK# Deassertion Time") from the January
  81                  * 2002 PIIX4 specification update.  Applies to only older
  82                  * PIIX4 models.
  83                  */
  84                 errata.piix4.throttle = 1;
  85
  86         case 2:         /* PIIX4E */
  87         case 3:         /* PIIX4M */
  88                 /*
  89                  * See erratum #18 ("C3 Power State/BMIDE and Type-F DMA
  90                  * Livelock") from the January 2002 PIIX4 specification update.
  91                  * Applies to all PIIX4 models.
  92                  */
  93
  94                 /*
  95                  * BM-IDE
  96                  * ------
  97                  * Find the PIIX4 IDE Controller and get the Bus Master IDE
  98                  * Status register address.  We'll use this later to read
  99                  * each IDE controller's DMA status to make sure we catch all
 100                  * DMA activity.
 101                  */
 102                 dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
 103                                      PCI_DEVICE_ID_INTEL_82371AB,
 104                                      PCI_ANY_ID, PCI_ANY_ID, NULL);
 105                 if (dev) {
 106                         errata.piix4.bmisx = pci_resource_start(dev, 4);
 107                         pci_dev_put(dev);
 108                 }
 109
 110                 /*
 111                  * Type-F DMA
 112                  * ----------
 113                  * Find the PIIX4 ISA Controller and read the Motherboard
 114                  * DMA controller's status to see if Type-F (Fast) DMA mode
 115                  * is enabled (bit 7) on either channel.  Note that we'll
 116                  * disable C3 support if this is enabled, as some legacy
 117                  * devices won't operate well if fast DMA is disabled.
 118                  */
 119                 dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
 120                                      PCI_DEVICE_ID_INTEL_82371AB_0,
 121                                      PCI_ANY_ID, PCI_ANY_ID, NULL);
 122                 if (dev) {
 123                         pci_read_config_byte(dev, 0x76, &value1);
 124                         pci_read_config_byte(dev, 0x77, &value2);
 125                         if ((value1 & 0x80) || (value2 & 0x80))
 126                                 errata.piix4.fdma = 1;
 127                         pci_dev_put(dev);
 128                 }
 129
 130                 break;
 131         }
 132
 133         if (errata.piix4.bmisx)
 134                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 135                                   "Bus master activity detection (BM-IDE) erratum enabled\n"));
 136         if (errata.piix4.fdma)
 137                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 138                                   "Type-F DMA livelock erratum (C3 disabled)\n"));
 139
 140         return 0;
 141 }
 142
 143 static int acpi_processor_errata(void)
 144 {
 145         int result = 0;
 146         struct pci_dev *dev = NULL;
 147
 148         /*
 149          * PIIX4
 150          */
 151         dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
 152                              PCI_DEVICE_ID_INTEL_82371AB_3, PCI_ANY_ID,
 153                              PCI_ANY_ID, NULL);
 154         if (dev) {
 155                 result = acpi_processor_errata_piix4(dev);
 156                 pci_dev_put(dev);
 157         }
 158
 159         return result;
 160 }
 161
 162 /* --------------------------------------------------------------------------
 163                                 Initialization
 164    -------------------------------------------------------------------------- */
 165
 166 #ifdef CONFIG_ACPI_HOTPLUG_CPU
 167 int __weak acpi_map_cpu(acpi_handle handle,
 168                 phys_cpuid_t physid, int *pcpu)
 169 {
 170         return -ENODEV;
 171 }
 172
 173 int __weak acpi_unmap_cpu(int cpu)
 174 {
 175         return -ENODEV;
 176 }
 177
 178 int __weak arch_register_cpu(int cpu)
 179 {
 180         return -ENODEV;
 181 }
 182
 183 void __weak arch_unregister_cpu(int cpu) {}
 184
 185 int __weak acpi_map_cpu2node(acpi_handle handle, int cpu, int physid)
 186 {
 187         return -ENODEV;
 188 }
 189
 190 static int acpi_processor_hotadd_init(struct acpi_processor *pr)
 191 {
 192         unsigned long long sta;
 193         acpi_status status;
 194         int ret;
 195
 196         if (invalid_phys_cpuid(pr->phys_id))
 197                 return -ENODEV;
 198
 199         status = acpi_evaluate_integer(pr->handle, "_STA", NULL, &sta);
 200         if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_PRESENT))
 201                 return -ENODEV;
 202
 203         cpu_maps_update_begin();
 204         cpu_hotplug_begin();
 205
 206         ret = acpi_map_cpu(pr->handle, pr->phys_id, &pr->id);
 207         if (ret)
 208                 goto out;
 209
 210         ret = arch_register_cpu(pr->id);
 211         if (ret) {
 212                 acpi_unmap_cpu(pr->id);
 213                 goto out;
 214         }
 215
 216         /*
 217          * CPU got hot-added, but cpu_data is not initialized yet.  Set a flag
 218          * to delay cpu_idle/throttling initialization and do it when the CPU
 219          * gets online for the first time.
 220          */
 221         pr_info("CPU%d has been hot-added\n", pr->id);
 222         pr->flags.need_hotplug_init = 1;
 223
 224 out:
 225         cpu_hotplug_done();
 226         cpu_maps_update_done();
 227         return ret;
 228 }
 229 #else
 230 static inline int acpi_processor_hotadd_init(struct acpi_processor *pr)
 231 {
 232         return -ENODEV;
 233 }
 234 #endif /* CONFIG_ACPI_HOTPLUG_CPU */
 235
 236 static int acpi_processor_get_info(struct acpi_device *device)
 237 {
 238         union acpi_object object = { 0 };
 239         struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
 240         struct acpi_processor *pr = acpi_driver_data(device);
 241         int device_declaration = 0;
 242         acpi_status status = AE_OK;
 243         static int cpu0_initialized;
 244         unsigned long long value;
 245
 246         acpi_processor_errata();
 247
 248         /*
 249          * Check to see if we have bus mastering arbitration control.  This
 250          * is required for proper C3 usage (to maintain cache coherency).
 251          */
 252         if (acpi_gbl_FADT.pm2_control_block && acpi_gbl_FADT.pm2_control_length) {
 253                 pr->flags.bm_control = 1;
 254                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 255                                   "Bus mastering arbitration control present\n"));
 256         } else
 257                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 258                                   "No bus mastering arbitration control\n"));
 259
 260         if (!strcmp(acpi_device_hid(device), ACPI_PROCESSOR_OBJECT_HID)) {
 261                 /* Declared with "Processor" statement; match ProcessorID */
 262                 status = acpi_evaluate_object(pr->handle, NULL, NULL, &buffer);
 263                 if (ACPI_FAILURE(status)) {
 264                         dev_err(&device->dev,
 265                                 "Failed to evaluate processor object (0x%x)\n",
 266                                 status);
 267                         return -ENODEV;
 268                 }
 269
 270                 pr->acpi_id = object.processor.proc_id;
 271         } else {
 272                 /*
 273                  * Declared with "Device" statement; match _UID.
 274                  * Note that we don't handle string _UIDs yet.
 275                  */
 276                 status = acpi_evaluate_integer(pr->handle, METHOD_NAME__UID,
 277                                                 NULL, &value);
 278                 if (ACPI_FAILURE(status)) {
 279                         dev_err(&device->dev,
 280                                 "Failed to evaluate processor _UID (0x%x)\n",
 281                                 status);
 282                         return -ENODEV;
 283                 }
 284                 device_declaration = 1;
 285                 pr->acpi_id = value;
 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 #ifdef CONFIG_SMP
 390         if (pr->id >= setup_max_cpus && pr->id != 0)
 391                 return 0;
 392 #endif
 393
 394         BUG_ON(pr->id >= nr_cpu_ids);
 395
 396         /*
 397          * Buggy BIOS check.
 398          * ACPI id of processors can be reported wrongly by the BIOS.
 399          * Don't trust it blindly
 400          */
 401         if (per_cpu(processor_device_array, pr->id) != NULL &&
 402             per_cpu(processor_device_array, pr->id) != device) {
 403                 dev_warn(&device->dev,
 404                         "BIOS reported wrong ACPI id %d for the processor\n",
 405                         pr->id);
 406                 /* Give up, but do not abort the namespace scan. */
 407                 goto err;
 408         }
 409         /*
 410          * processor_device_array is not cleared on errors to allow buggy BIOS
 411          * checks.
 412          */
 413         per_cpu(processor_device_array, pr->id) = device;
 414         per_cpu(processors, pr->id) = pr;
 415
 416         dev = get_cpu_device(pr->id);
 417         if (!dev) {
 418                 result = -ENODEV;
 419                 goto err;
 420         }
 421
 422         result = acpi_bind_one(dev, device);
 423         if (result)
 424                 goto err;
 425
 426         pr->dev = dev;
 427
 428         /* Trigger the processor driver's .probe() if present. */
 429         if (device_attach(dev) >= 0)
 430                 return 1;
 431
 432         dev_err(dev, "Processor driver could not be attached\n");
 433         acpi_unbind_one(dev);
 434
 435  err:
 436         free_cpumask_var(pr->throttling.shared_cpu_map);
 437         device->driver_data = NULL;
 438         per_cpu(processors, pr->id) = NULL;
 439  err_free_pr:
 440         kfree(pr);
 441         return result;
 442 }
 443
 444 #ifdef CONFIG_ACPI_HOTPLUG_CPU
 445 /* --------------------------------------------------------------------------
 446                                     Removal
 447    -------------------------------------------------------------------------- */
 448
 449 static void acpi_processor_remove(struct acpi_device *device)
 450 {
 451         struct acpi_processor *pr;
 452
 453         if (!device || !acpi_driver_data(device))
 454                 return;
 455
 456         pr = acpi_driver_data(device);
 457         if (pr->id >= nr_cpu_ids)
 458                 goto out;
 459
 460         /*
 461          * The only reason why we ever get here is CPU hot-removal.  The CPU is
 462          * already offline and the ACPI device removal locking prevents it from
 463          * being put back online at this point.
 464          *
 465          * Unbind the driver from the processor device and detach it from the
 466          * ACPI companion object.
 467          */
 468         device_release_driver(pr->dev);
 469         acpi_unbind_one(pr->dev);
 470
 471         /* Clean up. */
 472         per_cpu(processor_device_array, pr->id) = NULL;
 473         per_cpu(processors, pr->id) = NULL;
 474
 475         cpu_maps_update_begin();
 476         cpu_hotplug_begin();
 477
 478         /* Remove the CPU. */
 479         arch_unregister_cpu(pr->id);
 480         acpi_unmap_cpu(pr->id);
 481
 482         cpu_hotplug_done();
 483         cpu_maps_update_done();
 484
 485         try_offline_node(cpu_to_node(pr->id));
 486
 487  out:
 488         free_cpumask_var(pr->throttling.shared_cpu_map);
 489         kfree(pr);
 490 }
 491 #endif /* CONFIG_ACPI_HOTPLUG_CPU */
 492
 493 #ifdef CONFIG_X86
 494 static bool acpi_hwp_native_thermal_lvt_set;
 495 static acpi_status __init acpi_hwp_native_thermal_lvt_osc(acpi_handle handle,
 496                                                           u32 lvl,
 497                                                           void *context,
 498                                                           void **rv)
 499 {
 500         u8 sb_uuid_str[] = "4077A616-290C-47BE-9EBD-D87058713953";
 501         u32 capbuf[2];
 502         struct acpi_osc_context osc_context = {
 503                 .uuid_str = sb_uuid_str,
 504                 .rev = 1,
 505                 .cap.length = 8,
 506                 .cap.pointer = capbuf,
 507         };
 508
 509         if (acpi_hwp_native_thermal_lvt_set)
 510                 return AE_CTRL_TERMINATE;
 511
 512         capbuf[0] = 0x0000;
 513         capbuf[1] = 0x1000; /* set bit 12 */
 514
 515         if (ACPI_SUCCESS(acpi_run_osc(handle, &osc_context))) {
 516                 if (osc_context.ret.pointer && osc_context.ret.length > 1) {
 517                         u32 *capbuf_ret = osc_context.ret.pointer;
 518
 519                         if (capbuf_ret[1] & 0x1000) {
 520                                 acpi_handle_info(handle,
 521                                         "_OSC native thermal LVT Acked\n");
 522                                 acpi_hwp_native_thermal_lvt_set = true;
 523                         }
 524                 }
 525                 kfree(osc_context.ret.pointer);
 526         }
 527
 528         return AE_OK;
 529 }
 530
 531 void __init acpi_early_processor_osc(void)
 532 {
 533         if (boot_cpu_has(X86_FEATURE_HWP)) {
 534                 acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
 535                                     ACPI_UINT32_MAX,
 536                                     acpi_hwp_native_thermal_lvt_osc,
 537                                     NULL, NULL, NULL);
 538                 acpi_get_devices(ACPI_PROCESSOR_DEVICE_HID,
 539                                  acpi_hwp_native_thermal_lvt_osc,
 540                                  NULL, NULL);
 541         }
 542 }
 543 #endif
 544
 545 /*
 546  * The following ACPI IDs are known to be suitable for representing as
 547  * processor devices.
 548  */
 549 static const struct acpi_device_id processor_device_ids[] = {
 550
 551         { ACPI_PROCESSOR_OBJECT_HID, },
 552         { ACPI_PROCESSOR_DEVICE_HID, },
 553
 554         { }
 555 };
 556
 557 static struct acpi_scan_handler processor_handler = {
 558         .ids = processor_device_ids,
 559         .attach = acpi_processor_add,
 560 #ifdef CONFIG_ACPI_HOTPLUG_CPU
 561         .detach = acpi_processor_remove,
 562 #endif
 563         .hotplug = {
 564                 .enabled = true,
 565         },
 566 };
 567
 568 static int acpi_processor_container_attach(struct acpi_device *dev,
 569                                            const struct acpi_device_id *id)
 570 {
 571         return 1;
 572 }
 573
 574 static const struct acpi_device_id processor_container_ids[] = {
 575         { ACPI_PROCESSOR_CONTAINER_HID, },
 576         { }
 577 };
 578
 579 static struct acpi_scan_handler processor_container_handler = {
 580         .ids = processor_container_ids,
 581         .attach = acpi_processor_container_attach,
 582 };
 583
 584 /* The number of the unique processor IDs */
 585 static int nr_unique_ids __initdata;
 586
 587 /* The number of the duplicate processor IDs */
 588 static int nr_duplicate_ids __initdata;
 589
 590 /* Used to store the unique processor IDs */
 591 static int unique_processor_ids[] __initdata = {
 592         [0 ... NR_CPUS - 1] = -1,
 593 };
 594
 595 /* Used to store the duplicate processor IDs */
 596 static int duplicate_processor_ids[] __initdata = {
 597         [0 ... NR_CPUS - 1] = -1,
 598 };
 599
 600 static void __init processor_validated_ids_update(int proc_id)
 601 {
 602         int i;
 603
 604         if (nr_unique_ids == NR_CPUS||nr_duplicate_ids == NR_CPUS)
 605                 return;
 606
 607         /*
 608          * Firstly, compare the proc_id with duplicate IDs, if the proc_id is
 609          * already in the IDs, do nothing.
 610          */
 611         for (i = 0; i < nr_duplicate_ids; i++) {
 612                 if (duplicate_processor_ids[i] == proc_id)
 613                         return;
 614         }
 615
 616         /*
 617          * Secondly, compare the proc_id with unique IDs, if the proc_id is in
 618          * the IDs, put it in the duplicate IDs.
 619          */
 620         for (i = 0; i < nr_unique_ids; i++) {
 621                 if (unique_processor_ids[i] == proc_id) {
 622                         duplicate_processor_ids[nr_duplicate_ids] = proc_id;
 623                         nr_duplicate_ids++;
 624                         return;
 625                 }
 626         }
 627
 628         /*
 629          * Lastly, the proc_id is a unique ID, put it in the unique IDs.
 630          */
 631         unique_processor_ids[nr_unique_ids] = proc_id;
 632         nr_unique_ids++;
 633 }
 634
 635 static acpi_status __init acpi_processor_ids_walk(acpi_handle handle,
 636                                                   u32 lvl,
 637                                                   void *context,
 638                                                   void **rv)
 639 {
 640         acpi_status status;
 641         union acpi_object object = { 0 };
 642         struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
 643
 644         status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
 645         if (ACPI_FAILURE(status))
 646                 acpi_handle_info(handle, "Not get the processor object\n");
 647         else
 648                 processor_validated_ids_update(object.processor.proc_id);
 649
 650         return AE_OK;
 651 }
 652
 653 static void __init acpi_processor_check_duplicates(void)
 654 {
 655         /* Search all processor nodes in ACPI namespace */
 656         acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
 657                                                 ACPI_UINT32_MAX,
 658                                                 acpi_processor_ids_walk,
 659                                                 NULL, NULL, NULL);
 660 }
 661
 662 bool __init acpi_processor_validate_proc_id(int proc_id)
 663 {
 664         int i;
 665
 666         /*
 667          * compare the proc_id with duplicate IDs, if the proc_id is already
 668          * in the duplicate IDs, return true, otherwise, return false.
 669          */
 670         for (i = 0; i < nr_duplicate_ids; i++) {
 671                 if (duplicate_processor_ids[i] == proc_id)
 672                         return true;
 673         }
 674         return false;
 675 }
 676
 677 void __init acpi_processor_init(void)
 678 {
 679         acpi_processor_check_duplicates();
 680         acpi_scan_add_handler_with_hotplug(&processor_handler, "processor");
 681         acpi_scan_add_handler(&processor_container_handler);
 682 }