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                 /* fall through*/
  86
  87         case 2:         /* PIIX4E */
  88         case 3:         /* PIIX4M */
  89                 /*
  90                  * See erratum #18 ("C3 Power State/BMIDE and Type-F DMA
  91                  * Livelock") from the January 2002 PIIX4 specification update.
  92                  * Applies to all PIIX4 models.
  93                  */
  94
  95                 /*
  96                  * BM-IDE
  97                  * ------
  98                  * Find the PIIX4 IDE Controller and get the Bus Master IDE
  99                  * Status register address.  We'll use this later to read
 100                  * each IDE controller's DMA status to make sure we catch all
 101                  * DMA activity.
 102                  */
 103                 dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
 104                                      PCI_DEVICE_ID_INTEL_82371AB,
 105                                      PCI_ANY_ID, PCI_ANY_ID, NULL);
 106                 if (dev) {
 107                         errata.piix4.bmisx = pci_resource_start(dev, 4);
 108                         pci_dev_put(dev);
 109                 }
 110
 111                 /*
 112                  * Type-F DMA
 113                  * ----------
 114                  * Find the PIIX4 ISA Controller and read the Motherboard
 115                  * DMA controller's status to see if Type-F (Fast) DMA mode
 116                  * is enabled (bit 7) on either channel.  Note that we'll
 117                  * disable C3 support if this is enabled, as some legacy
 118                  * devices won't operate well if fast DMA is disabled.
 119                  */
 120                 dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
 121                                      PCI_DEVICE_ID_INTEL_82371AB_0,
 122                                      PCI_ANY_ID, PCI_ANY_ID, NULL);
 123                 if (dev) {
 124                         pci_read_config_byte(dev, 0x76, &value1);
 125                         pci_read_config_byte(dev, 0x77, &value2);
 126                         if ((value1 & 0x80) || (value2 & 0x80))
 127                                 errata.piix4.fdma = 1;
 128                         pci_dev_put(dev);
 129                 }
 130
 131                 break;
 132         }
 133
 134         if (errata.piix4.bmisx)
 135                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 136                                   "Bus master activity detection (BM-IDE) erratum enabled\n"));
 137         if (errata.piix4.fdma)
 138                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 139                                   "Type-F DMA livelock erratum (C3 disabled)\n"));
 140
 141         return 0;
 142 }
 143
 144 static int acpi_processor_errata(void)
 145 {
 146         int result = 0;
 147         struct pci_dev *dev = NULL;
 148
 149         /*
 150          * PIIX4
 151          */
 152         dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
 153                              PCI_DEVICE_ID_INTEL_82371AB_3, PCI_ANY_ID,
 154                              PCI_ANY_ID, NULL);
 155         if (dev) {
 156                 result = acpi_processor_errata_piix4(dev);
 157                 pci_dev_put(dev);
 158         }
 159
 160         return result;
 161 }
 162
 163 /* --------------------------------------------------------------------------
 164                                 Initialization
 165    -------------------------------------------------------------------------- */
 166
 167 #ifdef CONFIG_ACPI_HOTPLUG_CPU
 168 int __weak acpi_map_cpu(acpi_handle handle,
 169                 phys_cpuid_t physid, u32 acpi_id, int *pcpu)
 170 {
 171         return -ENODEV;
 172 }
 173
 174 int __weak acpi_unmap_cpu(int cpu)
 175 {
 176         return -ENODEV;
 177 }
 178
 179 int __weak arch_register_cpu(int cpu)
 180 {
 181         return -ENODEV;
 182 }
 183
 184 void __weak arch_unregister_cpu(int cpu) {}
 185
 186 static int acpi_processor_hotadd_init(struct acpi_processor *pr)
 187 {
 188         unsigned long long sta;
 189         acpi_status status;
 190         int ret;
 191
 192         if (invalid_phys_cpuid(pr->phys_id))
 193                 return -ENODEV;
 194
 195         status = acpi_evaluate_integer(pr->handle, "_STA", NULL, &sta);
 196         if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_PRESENT))
 197                 return -ENODEV;
 198
 199         cpu_maps_update_begin();
 200         cpu_hotplug_begin();
 201
 202         ret = acpi_map_cpu(pr->handle, pr->phys_id, pr->acpi_id, &pr->id);
 203         if (ret)
 204                 goto out;
 205
 206         ret = arch_register_cpu(pr->id);
 207         if (ret) {
 208                 acpi_unmap_cpu(pr->id);
 209                 goto out;
 210         }
 211
 212         /*
 213          * CPU got hot-added, but cpu_data is not initialized yet.  Set a flag
 214          * to delay cpu_idle/throttling initialization and do it when the CPU
 215          * gets online for the first time.
 216          */
 217         pr_info("CPU%d has been hot-added\n", pr->id);
 218         pr->flags.need_hotplug_init = 1;
 219
 220 out:
 221         cpu_hotplug_done();
 222         cpu_maps_update_done();
 223         return ret;
 224 }
 225 #else
 226 static inline int acpi_processor_hotadd_init(struct acpi_processor *pr)
 227 {
 228         return -ENODEV;
 229 }
 230 #endif /* CONFIG_ACPI_HOTPLUG_CPU */
 231
 232 static int acpi_processor_get_info(struct acpi_device *device)
 233 {
 234         union acpi_object object = { 0 };
 235         struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
 236         struct acpi_processor *pr = acpi_driver_data(device);
 237         int device_declaration = 0;
 238         acpi_status status = AE_OK;
 239         static int cpu0_initialized;
 240         unsigned long long value;
 241
 242         acpi_processor_errata();
 243
 244         /*
 245          * Check to see if we have bus mastering arbitration control.  This
 246          * is required for proper C3 usage (to maintain cache coherency).
 247          */
 248         if (acpi_gbl_FADT.pm2_control_block && acpi_gbl_FADT.pm2_control_length) {
 249                 pr->flags.bm_control = 1;
 250                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 251                                   "Bus mastering arbitration control present\n"));
 252         } else
 253                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 254                                   "No bus mastering arbitration control\n"));
 255
 256         if (!strcmp(acpi_device_hid(device), ACPI_PROCESSOR_OBJECT_HID)) {
 257                 /* Declared with "Processor" statement; match ProcessorID */
 258                 status = acpi_evaluate_object(pr->handle, NULL, NULL, &buffer);
 259                 if (ACPI_FAILURE(status)) {
 260                         dev_err(&device->dev,
 261                                 "Failed to evaluate processor object (0x%x)\n",
 262                                 status);
 263                         return -ENODEV;
 264                 }
 265
 266                 pr->acpi_id = object.processor.proc_id;
 267         } else {
 268                 /*
 269                  * Declared with "Device" statement; match _UID.
 270                  * Note that we don't handle string _UIDs yet.
 271                  */
 272                 status = acpi_evaluate_integer(pr->handle, METHOD_NAME__UID,
 273                                                 NULL, &value);
 274                 if (ACPI_FAILURE(status)) {
 275                         dev_err(&device->dev,
 276                                 "Failed to evaluate processor _UID (0x%x)\n",
 277                                 status);
 278                         return -ENODEV;
 279                 }
 280                 device_declaration = 1;
 281                 pr->acpi_id = value;
 282         }
 283
 284         if (acpi_duplicate_processor_id(pr->acpi_id)) {
 285                 if (pr->acpi_id == 0xff)
 286                         dev_info_once(&device->dev,
 287                                 "Entry not well-defined, consider updating BIOS\n");
 288                 else
 289                         dev_err(&device->dev,
 290                                 "Failed to get unique processor _UID (0x%x)\n",
 291                                 pr->acpi_id);
 292                 return -ENODEV;
 293         }
 294
 295         pr->phys_id = acpi_get_phys_id(pr->handle, device_declaration,
 296                                         pr->acpi_id);
 297         if (invalid_phys_cpuid(pr->phys_id))
 298                 acpi_handle_debug(pr->handle, "failed to get CPU physical ID.\n");
 299
 300         pr->id = acpi_map_cpuid(pr->phys_id, pr->acpi_id);
 301         if (!cpu0_initialized && !acpi_has_cpu_in_madt()) {
 302                 cpu0_initialized = 1;
 303                 /*
 304                  * Handle UP system running SMP kernel, with no CPU
 305                  * entry in MADT
 306                  */
 307                 if (invalid_logical_cpuid(pr->id) && (num_online_cpus() == 1))
 308                         pr->id = 0;
 309         }
 310
 311         /*
 312          *  Extra Processor objects may be enumerated on MP systems with
 313          *  less than the max # of CPUs. They should be ignored _iff
 314          *  they are physically not present.
 315          *
 316          *  NOTE: Even if the processor has a cpuid, it may not be present
 317          *  because cpuid <-> apicid mapping is persistent now.
 318          */
 319         if (invalid_logical_cpuid(pr->id) || !cpu_present(pr->id)) {
 320                 int ret = acpi_processor_hotadd_init(pr);
 321                 if (ret)
 322                         return ret;
 323         }
 324
 325         /*
 326          * On some boxes several processors use the same processor bus id.
 327          * But they are located in different scope. For example:
 328          * \_SB.SCK0.CPU0
 329          * \_SB.SCK1.CPU0
 330          * Rename the processor device bus id. And the new bus id will be
 331          * generated as the following format:
 332          * CPU+CPU ID.
 333          */
 334         sprintf(acpi_device_bid(device), "CPU%X", pr->id);
 335         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Processor [%d:%d]\n", pr->id,
 336                           pr->acpi_id));
 337
 338         if (!object.processor.pblk_address)
 339                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No PBLK (NULL address)\n"));
 340         else if (object.processor.pblk_length != 6)
 341                 dev_err(&device->dev, "Invalid PBLK length [%d]\n",
 342                             object.processor.pblk_length);
 343         else {
 344                 pr->throttling.address = object.processor.pblk_address;
 345                 pr->throttling.duty_offset = acpi_gbl_FADT.duty_offset;
 346                 pr->throttling.duty_width = acpi_gbl_FADT.duty_width;
 347
 348                 pr->pblk = object.processor.pblk_address;
 349         }
 350
 351         /*
 352          * If ACPI describes a slot number for this CPU, we can use it to
 353          * ensure we get the right value in the "physical id" field
 354          * of /proc/cpuinfo
 355          */
 356         status = acpi_evaluate_integer(pr->handle, "_SUN", NULL, &value);
 357         if (ACPI_SUCCESS(status))
 358                 arch_fix_phys_package_id(pr->id, value);
 359
 360         return 0;
 361 }
 362
 363 /*
 364  * Do not put anything in here which needs the core to be online.
 365  * For example MSR access or setting up things which check for cpuinfo_x86
 366  * (cpu_data(cpu)) values, like CPU feature flags, family, model, etc.
 367  * Such things have to be put in and set up by the processor driver's .probe().
 368  */
 369 static DEFINE_PER_CPU(void *, processor_device_array);
 370
 371 static int acpi_processor_add(struct acpi_device *device,
 372                                         const struct acpi_device_id *id)
 373 {
 374         struct acpi_processor *pr;
 375         struct device *dev;
 376         int result = 0;
 377
 378         pr = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL);
 379         if (!pr)
 380                 return -ENOMEM;
 381
 382         if (!zalloc_cpumask_var(&pr->throttling.shared_cpu_map, GFP_KERNEL)) {
 383                 result = -ENOMEM;
 384                 goto err_free_pr;
 385         }
 386
 387         pr->handle = device->handle;
 388         strcpy(acpi_device_name(device), ACPI_PROCESSOR_DEVICE_NAME);
 389         strcpy(acpi_device_class(device), ACPI_PROCESSOR_CLASS);
 390         device->driver_data = pr;
 391
 392         result = acpi_processor_get_info(device);
 393         if (result) /* Processor is not physically present or unavailable */
 394                 return 0;
 395
 396         BUG_ON(pr->id >= nr_cpu_ids);
 397
 398         /*
 399          * Buggy BIOS check.
 400          * ACPI id of processors can be reported wrongly by the BIOS.
 401          * Don't trust it blindly
 402          */
 403         if (per_cpu(processor_device_array, pr->id) != NULL &&
 404             per_cpu(processor_device_array, pr->id) != device) {
 405                 dev_warn(&device->dev,
 406                         "BIOS reported wrong ACPI id %d for the processor\n",
 407                         pr->id);
 408                 /* Give up, but do not abort the namespace scan. */
 409                 goto err;
 410         }
 411         /*
 412          * processor_device_array is not cleared on errors to allow buggy BIOS
 413          * checks.
 414          */
 415         per_cpu(processor_device_array, pr->id) = device;
 416         per_cpu(processors, pr->id) = pr;
 417
 418         dev = get_cpu_device(pr->id);
 419         if (!dev) {
 420                 result = -ENODEV;
 421                 goto err;
 422         }
 423
 424         result = acpi_bind_one(dev, device);
 425         if (result)
 426                 goto err;
 427
 428         pr->dev = dev;
 429
 430         /* Trigger the processor driver's .probe() if present. */
 431         if (device_attach(dev) >= 0)
 432                 return 1;
 433
 434         dev_err(dev, "Processor driver could not be attached\n");
 435         acpi_unbind_one(dev);
 436
 437  err:
 438         free_cpumask_var(pr->throttling.shared_cpu_map);
 439         device->driver_data = NULL;
 440         per_cpu(processors, pr->id) = NULL;
 441  err_free_pr:
 442         kfree(pr);
 443         return result;
 444 }
 445
 446 #ifdef CONFIG_ACPI_HOTPLUG_CPU
 447 /* --------------------------------------------------------------------------
 448                                     Removal
 449    -------------------------------------------------------------------------- */
 450
 451 static void acpi_processor_remove(struct acpi_device *device)
 452 {
 453         struct acpi_processor *pr;
 454
 455         if (!device || !acpi_driver_data(device))
 456                 return;
 457
 458         pr = acpi_driver_data(device);
 459         if (pr->id >= nr_cpu_ids)
 460                 goto out;
 461
 462         /*
 463          * The only reason why we ever get here is CPU hot-removal.  The CPU is
 464          * already offline and the ACPI device removal locking prevents it from
 465          * being put back online at this point.
 466          *
 467          * Unbind the driver from the processor device and detach it from the
 468          * ACPI companion object.
 469          */
 470         device_release_driver(pr->dev);
 471         acpi_unbind_one(pr->dev);
 472
 473         /* Clean up. */
 474         per_cpu(processor_device_array, pr->id) = NULL;
 475         per_cpu(processors, pr->id) = NULL;
 476
 477         cpu_maps_update_begin();
 478         cpu_hotplug_begin();
 479
 480         /* Remove the CPU. */
 481         arch_unregister_cpu(pr->id);
 482         acpi_unmap_cpu(pr->id);
 483
 484         cpu_hotplug_done();
 485         cpu_maps_update_done();
 486
 487         try_offline_node(cpu_to_node(pr->id));
 488
 489  out:
 490         free_cpumask_var(pr->throttling.shared_cpu_map);
 491         kfree(pr);
 492 }
 493 #endif /* CONFIG_ACPI_HOTPLUG_CPU */
 494
 495 #ifdef CONFIG_X86
 496 static bool acpi_hwp_native_thermal_lvt_set;
 497 static acpi_status __init acpi_hwp_native_thermal_lvt_osc(acpi_handle handle,
 498                                                           u32 lvl,
 499                                                           void *context,
 500                                                           void **rv)
 501 {
 502         u8 sb_uuid_str[] = "4077A616-290C-47BE-9EBD-D87058713953";
 503         u32 capbuf[2];
 504         struct acpi_osc_context osc_context = {
 505                 .uuid_str = sb_uuid_str,
 506                 .rev = 1,
 507                 .cap.length = 8,
 508                 .cap.pointer = capbuf,
 509         };
 510
 511         if (acpi_hwp_native_thermal_lvt_set)
 512                 return AE_CTRL_TERMINATE;
 513
 514         capbuf[0] = 0x0000;
 515         capbuf[1] = 0x1000; /* set bit 12 */
 516
 517         if (ACPI_SUCCESS(acpi_run_osc(handle, &osc_context))) {
 518                 if (osc_context.ret.pointer && osc_context.ret.length > 1) {
 519                         u32 *capbuf_ret = osc_context.ret.pointer;
 520
 521                         if (capbuf_ret[1] & 0x1000) {
 522                                 acpi_handle_info(handle,
 523                                         "_OSC native thermal LVT Acked\n");
 524                                 acpi_hwp_native_thermal_lvt_set = true;
 525                         }
 526                 }
 527                 kfree(osc_context.ret.pointer);
 528         }
 529
 530         return AE_OK;
 531 }
 532
 533 void __init acpi_early_processor_osc(void)
 534 {
 535         if (boot_cpu_has(X86_FEATURE_HWP)) {
 536                 acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
 537                                     ACPI_UINT32_MAX,
 538                                     acpi_hwp_native_thermal_lvt_osc,
 539                                     NULL, NULL, NULL);
 540                 acpi_get_devices(ACPI_PROCESSOR_DEVICE_HID,
 541                                  acpi_hwp_native_thermal_lvt_osc,
 542                                  NULL, NULL);
 543         }
 544 }
 545 #endif
 546
 547 /*
 548  * The following ACPI IDs are known to be suitable for representing as
 549  * processor devices.
 550  */
 551 static const struct acpi_device_id processor_device_ids[] = {
 552
 553         { ACPI_PROCESSOR_OBJECT_HID, },
 554         { ACPI_PROCESSOR_DEVICE_HID, },
 555
 556         { }
 557 };
 558
 559 static struct acpi_scan_handler processor_handler = {
 560         .ids = processor_device_ids,
 561         .attach = acpi_processor_add,
 562 #ifdef CONFIG_ACPI_HOTPLUG_CPU
 563         .detach = acpi_processor_remove,
 564 #endif
 565         .hotplug = {
 566                 .enabled = true,
 567         },
 568 };
 569
 570 static int acpi_processor_container_attach(struct acpi_device *dev,
 571                                            const struct acpi_device_id *id)
 572 {
 573         return 1;
 574 }
 575
 576 static const struct acpi_device_id processor_container_ids[] = {
 577         { ACPI_PROCESSOR_CONTAINER_HID, },
 578         { }
 579 };
 580
 581 static struct acpi_scan_handler processor_container_handler = {
 582         .ids = processor_container_ids,
 583         .attach = acpi_processor_container_attach,
 584 };
 585
 586 /* The number of the unique processor IDs */
 587 static int nr_unique_ids __initdata;
 588
 589 /* The number of the duplicate processor IDs */
 590 static int nr_duplicate_ids;
 591
 592 /* Used to store the unique processor IDs */
 593 static int unique_processor_ids[] __initdata = {
 594         [0 ... NR_CPUS - 1] = -1,
 595 };
 596
 597 /* Used to store the duplicate processor IDs */
 598 static int duplicate_processor_ids[] = {
 599         [0 ... NR_CPUS - 1] = -1,
 600 };
 601
 602 static void __init processor_validated_ids_update(int proc_id)
 603 {
 604         int i;
 605
 606         if (nr_unique_ids == NR_CPUS||nr_duplicate_ids == NR_CPUS)
 607                 return;
 608
 609         /*
 610          * Firstly, compare the proc_id with duplicate IDs, if the proc_id is
 611          * already in the IDs, do nothing.
 612          */
 613         for (i = 0; i < nr_duplicate_ids; i++) {
 614                 if (duplicate_processor_ids[i] == proc_id)
 615                         return;
 616         }
 617
 618         /*
 619          * Secondly, compare the proc_id with unique IDs, if the proc_id is in
 620          * the IDs, put it in the duplicate IDs.
 621          */
 622         for (i = 0; i < nr_unique_ids; i++) {
 623                 if (unique_processor_ids[i] == proc_id) {
 624                         duplicate_processor_ids[nr_duplicate_ids] = proc_id;
 625                         nr_duplicate_ids++;
 626                         return;
 627                 }
 628         }
 629
 630         /*
 631          * Lastly, the proc_id is a unique ID, put it in the unique IDs.
 632          */
 633         unique_processor_ids[nr_unique_ids] = proc_id;
 634         nr_unique_ids++;
 635 }
 636
 637 static acpi_status __init acpi_processor_ids_walk(acpi_handle handle,
 638                                                   u32 lvl,
 639                                                   void *context,
 640                                                   void **rv)
 641 {
 642         acpi_status status;
 643         acpi_object_type acpi_type;
 644         unsigned long long uid;
 645         union acpi_object object = { 0 };
 646         struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
 647
 648         status = acpi_get_type(handle, &acpi_type);
 649         if (ACPI_FAILURE(status))
 650                 return status;
 651
 652         switch (acpi_type) {
 653         case ACPI_TYPE_PROCESSOR:
 654                 status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
 655                 if (ACPI_FAILURE(status))
 656                         goto err;
 657                 uid = object.processor.proc_id;
 658                 break;
 659
 660         case ACPI_TYPE_DEVICE:
 661                 status = acpi_evaluate_integer(handle, "_UID", NULL, &uid);
 662                 if (ACPI_FAILURE(status))
 663                         goto err;
 664                 break;
 665         default:
 666                 goto err;
 667         }
 668
 669         processor_validated_ids_update(uid);
 670         return AE_OK;
 671
 672 err:
 673         /* Exit on error, but don't abort the namespace walk */
 674         acpi_handle_info(handle, "Invalid processor object\n");
 675         return AE_OK;
 676
 677 }
 678
 679 static void __init acpi_processor_check_duplicates(void)
 680 {
 681         /* check the correctness for all processors in ACPI namespace */
 682         acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
 683                                                 ACPI_UINT32_MAX,
 684                                                 acpi_processor_ids_walk,
 685                                                 NULL, NULL, NULL);
 686         acpi_get_devices(ACPI_PROCESSOR_DEVICE_HID, acpi_processor_ids_walk,
 687                                                 NULL, NULL);
 688 }
 689
 690 bool acpi_duplicate_processor_id(int proc_id)
 691 {
 692         int i;
 693
 694         /*
 695          * compare the proc_id with duplicate IDs, if the proc_id is already
 696          * in the duplicate IDs, return true, otherwise, return false.
 697          */
 698         for (i = 0; i < nr_duplicate_ids; i++) {
 699                 if (duplicate_processor_ids[i] == proc_id)
 700                         return true;
 701         }
 702         return false;
 703 }
 704
 705 void __init acpi_processor_init(void)
 706 {
 707         acpi_processor_check_duplicates();
 708         acpi_scan_add_handler_with_hotplug(&processor_handler, "processor");
 709         acpi_scan_add_handler(&processor_container_handler);
 710 }