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                 if (pr->acpi_id == 0xff)
 283                         dev_info_once(&device->dev,
 284                                 "Entry not well-defined, consider updating BIOS\n");
 285                 else
 286                         dev_err(&device->dev,
 287                                 "Failed to get unique processor _UID (0x%x)\n",
 288                                 pr->acpi_id);
 289                 return -ENODEV;
 290         }
 291
 292         pr->phys_id = acpi_get_phys_id(pr->handle, device_declaration,
 293                                         pr->acpi_id);
 294         if (invalid_phys_cpuid(pr->phys_id))
 295                 acpi_handle_debug(pr->handle, "failed to get CPU physical ID.\n");
 296
 297         pr->id = acpi_map_cpuid(pr->phys_id, pr->acpi_id);
 298         if (!cpu0_initialized && !acpi_has_cpu_in_madt()) {
 299                 cpu0_initialized = 1;
 300                 /*
 301                  * Handle UP system running SMP kernel, with no CPU
 302                  * entry in MADT
 303                  */
 304                 if (invalid_logical_cpuid(pr->id) && (num_online_cpus() == 1))
 305                         pr->id = 0;
 306         }
 307
 308         /*
 309          *  Extra Processor objects may be enumerated on MP systems with
 310          *  less than the max # of CPUs. They should be ignored _iff
 311          *  they are physically not present.
 312          *
 313          *  NOTE: Even if the processor has a cpuid, it may not be present
 314          *  because cpuid <-> apicid mapping is persistent now.
 315          */
 316         if (invalid_logical_cpuid(pr->id) || !cpu_present(pr->id)) {
 317                 int ret = acpi_processor_hotadd_init(pr);
 318                 if (ret)
 319                         return ret;
 320         }
 321
 322         /*
 323          * On some boxes several processors use the same processor bus id.
 324          * But they are located in different scope. For example:
 325          * \_SB.SCK0.CPU0
 326          * \_SB.SCK1.CPU0
 327          * Rename the processor device bus id. And the new bus id will be
 328          * generated as the following format:
 329          * CPU+CPU ID.
 330          */
 331         sprintf(acpi_device_bid(device), "CPU%X", pr->id);
 332         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Processor [%d:%d]\n", pr->id,
 333                           pr->acpi_id));
 334
 335         if (!object.processor.pblk_address)
 336                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No PBLK (NULL address)\n"));
 337         else if (object.processor.pblk_length != 6)
 338                 dev_err(&device->dev, "Invalid PBLK length [%d]\n",
 339                             object.processor.pblk_length);
 340         else {
 341                 pr->throttling.address = object.processor.pblk_address;
 342                 pr->throttling.duty_offset = acpi_gbl_FADT.duty_offset;
 343                 pr->throttling.duty_width = acpi_gbl_FADT.duty_width;
 344
 345                 pr->pblk = object.processor.pblk_address;
 346         }
 347
 348         /*
 349          * If ACPI describes a slot number for this CPU, we can use it to
 350          * ensure we get the right value in the "physical id" field
 351          * of /proc/cpuinfo
 352          */
 353         status = acpi_evaluate_integer(pr->handle, "_SUN", NULL, &value);
 354         if (ACPI_SUCCESS(status))
 355                 arch_fix_phys_package_id(pr->id, value);
 356
 357         return 0;
 358 }
 359
 360 /*
 361  * Do not put anything in here which needs the core to be online.
 362  * For example MSR access or setting up things which check for cpuinfo_x86
 363  * (cpu_data(cpu)) values, like CPU feature flags, family, model, etc.
 364  * Such things have to be put in and set up by the processor driver's .probe().
 365  */
 366 static DEFINE_PER_CPU(void *, processor_device_array);
 367
 368 static int acpi_processor_add(struct acpi_device *device,
 369                                         const struct acpi_device_id *id)
 370 {
 371         struct acpi_processor *pr;
 372         struct device *dev;
 373         int result = 0;
 374
 375         pr = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL);
 376         if (!pr)
 377                 return -ENOMEM;
 378
 379         if (!zalloc_cpumask_var(&pr->throttling.shared_cpu_map, GFP_KERNEL)) {
 380                 result = -ENOMEM;
 381                 goto err_free_pr;
 382         }
 383
 384         pr->handle = device->handle;
 385         strcpy(acpi_device_name(device), ACPI_PROCESSOR_DEVICE_NAME);
 386         strcpy(acpi_device_class(device), ACPI_PROCESSOR_CLASS);
 387         device->driver_data = pr;
 388
 389         result = acpi_processor_get_info(device);
 390         if (result) /* Processor is not physically present or unavailable */
 391                 return 0;
 392
 393         BUG_ON(pr->id >= nr_cpu_ids);
 394
 395         /*
 396          * Buggy BIOS check.
 397          * ACPI id of processors can be reported wrongly by the BIOS.
 398          * Don't trust it blindly
 399          */
 400         if (per_cpu(processor_device_array, pr->id) != NULL &&
 401             per_cpu(processor_device_array, pr->id) != device) {
 402                 dev_warn(&device->dev,
 403                         "BIOS reported wrong ACPI id %d for the processor\n",
 404                         pr->id);
 405                 /* Give up, but do not abort the namespace scan. */
 406                 goto err;
 407         }
 408         /*
 409          * processor_device_array is not cleared on errors to allow buggy BIOS
 410          * checks.
 411          */
 412         per_cpu(processor_device_array, pr->id) = device;
 413         per_cpu(processors, pr->id) = pr;
 414
 415         dev = get_cpu_device(pr->id);
 416         if (!dev) {
 417                 result = -ENODEV;
 418                 goto err;
 419         }
 420
 421         result = acpi_bind_one(dev, device);
 422         if (result)
 423                 goto err;
 424
 425         pr->dev = dev;
 426
 427         /* Trigger the processor driver's .probe() if present. */
 428         if (device_attach(dev) >= 0)
 429                 return 1;
 430
 431         dev_err(dev, "Processor driver could not be attached\n");
 432         acpi_unbind_one(dev);
 433
 434  err:
 435         free_cpumask_var(pr->throttling.shared_cpu_map);
 436         device->driver_data = NULL;
 437         per_cpu(processors, pr->id) = NULL;
 438  err_free_pr:
 439         kfree(pr);
 440         return result;
 441 }
 442
 443 #ifdef CONFIG_ACPI_HOTPLUG_CPU
 444 /* --------------------------------------------------------------------------
 445                                     Removal
 446    -------------------------------------------------------------------------- */
 447
 448 static void acpi_processor_remove(struct acpi_device *device)
 449 {
 450         struct acpi_processor *pr;
 451
 452         if (!device || !acpi_driver_data(device))
 453                 return;
 454
 455         pr = acpi_driver_data(device);
 456         if (pr->id >= nr_cpu_ids)
 457                 goto out;
 458
 459         /*
 460          * The only reason why we ever get here is CPU hot-removal.  The CPU is
 461          * already offline and the ACPI device removal locking prevents it from
 462          * being put back online at this point.
 463          *
 464          * Unbind the driver from the processor device and detach it from the
 465          * ACPI companion object.
 466          */
 467         device_release_driver(pr->dev);
 468         acpi_unbind_one(pr->dev);
 469
 470         /* Clean up. */
 471         per_cpu(processor_device_array, pr->id) = NULL;
 472         per_cpu(processors, pr->id) = NULL;
 473
 474         cpu_maps_update_begin();
 475         cpu_hotplug_begin();
 476
 477         /* Remove the CPU. */
 478         arch_unregister_cpu(pr->id);
 479         acpi_unmap_cpu(pr->id);
 480
 481         cpu_hotplug_done();
 482         cpu_maps_update_done();
 483
 484         try_offline_node(cpu_to_node(pr->id));
 485
 486  out:
 487         free_cpumask_var(pr->throttling.shared_cpu_map);
 488         kfree(pr);
 489 }
 490 #endif /* CONFIG_ACPI_HOTPLUG_CPU */
 491
 492 #ifdef CONFIG_X86
 493 static bool acpi_hwp_native_thermal_lvt_set;
 494 static acpi_status __init acpi_hwp_native_thermal_lvt_osc(acpi_handle handle,
 495                                                           u32 lvl,
 496                                                           void *context,
 497                                                           void **rv)
 498 {
 499         u8 sb_uuid_str[] = "4077A616-290C-47BE-9EBD-D87058713953";
 500         u32 capbuf[2];
 501         struct acpi_osc_context osc_context = {
 502                 .uuid_str = sb_uuid_str,
 503                 .rev = 1,
 504                 .cap.length = 8,
 505                 .cap.pointer = capbuf,
 506         };
 507
 508         if (acpi_hwp_native_thermal_lvt_set)
 509                 return AE_CTRL_TERMINATE;
 510
 511         capbuf[0] = 0x0000;
 512         capbuf[1] = 0x1000; /* set bit 12 */
 513
 514         if (ACPI_SUCCESS(acpi_run_osc(handle, &osc_context))) {
 515                 if (osc_context.ret.pointer && osc_context.ret.length > 1) {
 516                         u32 *capbuf_ret = osc_context.ret.pointer;
 517
 518                         if (capbuf_ret[1] & 0x1000) {
 519                                 acpi_handle_info(handle,
 520                                         "_OSC native thermal LVT Acked\n");
 521                                 acpi_hwp_native_thermal_lvt_set = true;
 522                         }
 523                 }
 524                 kfree(osc_context.ret.pointer);
 525         }
 526
 527         return AE_OK;
 528 }
 529
 530 void __init acpi_early_processor_osc(void)
 531 {
 532         if (boot_cpu_has(X86_FEATURE_HWP)) {
 533                 acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
 534                                     ACPI_UINT32_MAX,
 535                                     acpi_hwp_native_thermal_lvt_osc,
 536                                     NULL, NULL, NULL);
 537                 acpi_get_devices(ACPI_PROCESSOR_DEVICE_HID,
 538                                  acpi_hwp_native_thermal_lvt_osc,
 539                                  NULL, NULL);
 540         }
 541 }
 542 #endif
 543
 544 /*
 545  * The following ACPI IDs are known to be suitable for representing as
 546  * processor devices.
 547  */
 548 static const struct acpi_device_id processor_device_ids[] = {
 549
 550         { ACPI_PROCESSOR_OBJECT_HID, },
 551         { ACPI_PROCESSOR_DEVICE_HID, },
 552
 553         { }
 554 };
 555
 556 static struct acpi_scan_handler processor_handler = {
 557         .ids = processor_device_ids,
 558         .attach = acpi_processor_add,
 559 #ifdef CONFIG_ACPI_HOTPLUG_CPU
 560         .detach = acpi_processor_remove,
 561 #endif
 562         .hotplug = {
 563                 .enabled = true,
 564         },
 565 };
 566
 567 static int acpi_processor_container_attach(struct acpi_device *dev,
 568                                            const struct acpi_device_id *id)
 569 {
 570         return 1;
 571 }
 572
 573 static const struct acpi_device_id processor_container_ids[] = {
 574         { ACPI_PROCESSOR_CONTAINER_HID, },
 575         { }
 576 };
 577
 578 static struct acpi_scan_handler processor_container_handler = {
 579         .ids = processor_container_ids,
 580         .attach = acpi_processor_container_attach,
 581 };
 582
 583 /* The number of the unique processor IDs */
 584 static int nr_unique_ids __initdata;
 585
 586 /* The number of the duplicate processor IDs */
 587 static int nr_duplicate_ids;
 588
 589 /* Used to store the unique processor IDs */
 590 static int unique_processor_ids[] __initdata = {
 591         [0 ... NR_CPUS - 1] = -1,
 592 };
 593
 594 /* Used to store the duplicate processor IDs */
 595 static int duplicate_processor_ids[] = {
 596         [0 ... NR_CPUS - 1] = -1,
 597 };
 598
 599 static void __init processor_validated_ids_update(int proc_id)
 600 {
 601         int i;
 602
 603         if (nr_unique_ids == NR_CPUS||nr_duplicate_ids == NR_CPUS)
 604                 return;
 605
 606         /*
 607          * Firstly, compare the proc_id with duplicate IDs, if the proc_id is
 608          * already in the IDs, do nothing.
 609          */
 610         for (i = 0; i < nr_duplicate_ids; i++) {
 611                 if (duplicate_processor_ids[i] == proc_id)
 612                         return;
 613         }
 614
 615         /*
 616          * Secondly, compare the proc_id with unique IDs, if the proc_id is in
 617          * the IDs, put it in the duplicate IDs.
 618          */
 619         for (i = 0; i < nr_unique_ids; i++) {
 620                 if (unique_processor_ids[i] == proc_id) {
 621                         duplicate_processor_ids[nr_duplicate_ids] = proc_id;
 622                         nr_duplicate_ids++;
 623                         return;
 624                 }
 625         }
 626
 627         /*
 628          * Lastly, the proc_id is a unique ID, put it in the unique IDs.
 629          */
 630         unique_processor_ids[nr_unique_ids] = proc_id;
 631         nr_unique_ids++;
 632 }
 633
 634 static acpi_status __init acpi_processor_ids_walk(acpi_handle handle,
 635                                                   u32 lvl,
 636                                                   void *context,
 637                                                   void **rv)
 638 {
 639         acpi_status status;
 640         acpi_object_type acpi_type;
 641         unsigned long long uid;
 642         union acpi_object object = { 0 };
 643         struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
 644
 645         status = acpi_get_type(handle, &acpi_type);
 646         if (ACPI_FAILURE(status))
 647                 return status;
 648
 649         switch (acpi_type) {
 650         case ACPI_TYPE_PROCESSOR:
 651                 status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
 652                 if (ACPI_FAILURE(status))
 653                         goto err;
 654                 uid = object.processor.proc_id;
 655                 break;
 656
 657         case ACPI_TYPE_DEVICE:
 658                 status = acpi_evaluate_integer(handle, "_UID", NULL, &uid);
 659                 if (ACPI_FAILURE(status))
 660                         goto err;
 661                 break;
 662         default:
 663                 goto err;
 664         }
 665
 666         processor_validated_ids_update(uid);
 667         return AE_OK;
 668
 669 err:
 670         /* Exit on error, but don't abort the namespace walk */
 671         acpi_handle_info(handle, "Invalid processor object\n");
 672         return AE_OK;
 673
 674 }
 675
 676 static void __init acpi_processor_check_duplicates(void)
 677 {
 678         /* check the correctness for all processors in ACPI namespace */
 679         acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
 680                                                 ACPI_UINT32_MAX,
 681                                                 acpi_processor_ids_walk,
 682                                                 NULL, NULL, NULL);
 683         acpi_get_devices(ACPI_PROCESSOR_DEVICE_HID, acpi_processor_ids_walk,
 684                                                 NULL, NULL);
 685 }
 686
 687 bool acpi_duplicate_processor_id(int proc_id)
 688 {
 689         int i;
 690
 691         /*
 692          * compare the proc_id with duplicate IDs, if the proc_id is already
 693          * in the duplicate IDs, return true, otherwise, return false.
 694          */
 695         for (i = 0; i < nr_duplicate_ids; i++) {
 696                 if (duplicate_processor_ids[i] == proc_id)
 697                         return true;
 698         }
 699         return false;
 700 }
 701
 702 void __init acpi_processor_init(void)
 703 {
 704         acpi_processor_check_duplicates();
 705         acpi_scan_add_handler_with_hotplug(&processor_handler, "processor");
 706         acpi_scan_add_handler(&processor_container_handler);
 707 }