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_PER_CPU(struct acpi_processor *, processors);
  26 EXPORT_PER_CPU_SYMBOL(processors);
  27
  28 /* Errata Handling */
  29 struct acpi_processor_errata errata __read_mostly;
  30 EXPORT_SYMBOL_GPL(errata);
  31
  32 static int acpi_processor_errata_piix4(struct pci_dev *dev)
  33 {
  34         u8 value1 = 0;
  35         u8 value2 = 0;
  36
  37
  38         if (!dev)
  39                 return -EINVAL;
  40
  41         /*
  42          * Note that 'dev' references the PIIX4 ACPI Controller.
  43          */
  44
  45         switch (dev->revision) {
  46         case 0:
  47                 dev_dbg(&dev->dev, "Found PIIX4 A-step\n");
  48                 break;
  49         case 1:
  50                 dev_dbg(&dev->dev, "Found PIIX4 B-step\n");
  51                 break;
  52         case 2:
  53                 dev_dbg(&dev->dev, "Found PIIX4E\n");
  54                 break;
  55         case 3:
  56                 dev_dbg(&dev->dev, "Found PIIX4M\n");
  57                 break;
  58         default:
  59                 dev_dbg(&dev->dev, "Found unknown PIIX4\n");
  60                 break;
  61         }
  62
  63         switch (dev->revision) {
  64
  65         case 0:         /* PIIX4 A-step */
  66         case 1:         /* PIIX4 B-step */
  67                 /*
  68                  * See specification changes #13 ("Manual Throttle Duty Cycle")
  69                  * and #14 ("Enabling and Disabling Manual Throttle"), plus
  70                  * erratum #5 ("STPCLK# Deassertion Time") from the January
  71                  * 2002 PIIX4 specification update.  Applies to only older
  72                  * PIIX4 models.
  73                  */
  74                 errata.piix4.throttle = 1;
  75                 fallthrough;
  76
  77         case 2:         /* PIIX4E */
  78         case 3:         /* PIIX4M */
  79                 /*
  80                  * See erratum #18 ("C3 Power State/BMIDE and Type-F DMA
  81                  * Livelock") from the January 2002 PIIX4 specification update.
  82                  * Applies to all PIIX4 models.
  83                  */
  84
  85                 /*
  86                  * BM-IDE
  87                  * ------
  88                  * Find the PIIX4 IDE Controller and get the Bus Master IDE
  89                  * Status register address.  We'll use this later to read
  90                  * each IDE controller's DMA status to make sure we catch all
  91                  * DMA activity.
  92                  */
  93                 dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
  94                                      PCI_DEVICE_ID_INTEL_82371AB,
  95                                      PCI_ANY_ID, PCI_ANY_ID, NULL);
  96                 if (dev) {
  97                         errata.piix4.bmisx = pci_resource_start(dev, 4);
  98                         pci_dev_put(dev);
  99                 }
 100
 101                 /*
 102                  * Type-F DMA
 103                  * ----------
 104                  * Find the PIIX4 ISA Controller and read the Motherboard
 105                  * DMA controller's status to see if Type-F (Fast) DMA mode
 106                  * is enabled (bit 7) on either channel.  Note that we'll
 107                  * disable C3 support if this is enabled, as some legacy
 108                  * devices won't operate well if fast DMA is disabled.
 109                  */
 110                 dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
 111                                      PCI_DEVICE_ID_INTEL_82371AB_0,
 112                                      PCI_ANY_ID, PCI_ANY_ID, NULL);
 113                 if (dev) {
 114                         pci_read_config_byte(dev, 0x76, &value1);
 115                         pci_read_config_byte(dev, 0x77, &value2);
 116                         if ((value1 & 0x80) || (value2 & 0x80))
 117                                 errata.piix4.fdma = 1;
 118                         pci_dev_put(dev);
 119                 }
 120
 121                 break;
 122         }
 123
 124         if (errata.piix4.bmisx)
 125                 dev_dbg(&dev->dev, "Bus master activity detection (BM-IDE) erratum enabled\n");
 126         if (errata.piix4.fdma)
 127                 dev_dbg(&dev->dev, "Type-F DMA livelock erratum (C3 disabled)\n");
 128
 129         return 0;
 130 }
 131
 132 static int acpi_processor_errata(void)
 133 {
 134         int result = 0;
 135         struct pci_dev *dev = NULL;
 136
 137         /*
 138          * PIIX4
 139          */
 140         dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
 141                              PCI_DEVICE_ID_INTEL_82371AB_3, PCI_ANY_ID,
 142                              PCI_ANY_ID, NULL);
 143         if (dev) {
 144                 result = acpi_processor_errata_piix4(dev);
 145                 pci_dev_put(dev);
 146         }
 147
 148         return result;
 149 }
 150
 151 /* Initialization */
 152 #ifdef CONFIG_ACPI_HOTPLUG_CPU
 153 int __weak acpi_map_cpu(acpi_handle handle,
 154                 phys_cpuid_t physid, u32 acpi_id, int *pcpu)
 155 {
 156         return -ENODEV;
 157 }
 158
 159 int __weak acpi_unmap_cpu(int cpu)
 160 {
 161         return -ENODEV;
 162 }
 163
 164 int __weak arch_register_cpu(int cpu)
 165 {
 166         return -ENODEV;
 167 }
 168
 169 void __weak arch_unregister_cpu(int cpu) {}
 170
 171 static int acpi_processor_hotadd_init(struct acpi_processor *pr)
 172 {
 173         unsigned long long sta;
 174         acpi_status status;
 175         int ret;
 176
 177         if (invalid_phys_cpuid(pr->phys_id))
 178                 return -ENODEV;
 179
 180         status = acpi_evaluate_integer(pr->handle, "_STA", NULL, &sta);
 181         if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_PRESENT))
 182                 return -ENODEV;
 183
 184         cpu_maps_update_begin();
 185         cpus_write_lock();
 186
 187         ret = acpi_map_cpu(pr->handle, pr->phys_id, pr->acpi_id, &pr->id);
 188         if (ret)
 189                 goto out;
 190
 191         ret = arch_register_cpu(pr->id);
 192         if (ret) {
 193                 acpi_unmap_cpu(pr->id);
 194                 goto out;
 195         }
 196
 197         /*
 198          * CPU got hot-added, but cpu_data is not initialized yet.  Set a flag
 199          * to delay cpu_idle/throttling initialization and do it when the CPU
 200          * gets online for the first time.
 201          */
 202         pr_info("CPU%d has been hot-added\n", pr->id);
 203         pr->flags.need_hotplug_init = 1;
 204
 205 out:
 206         cpus_write_unlock();
 207         cpu_maps_update_done();
 208         return ret;
 209 }
 210 #else
 211 static inline int acpi_processor_hotadd_init(struct acpi_processor *pr)
 212 {
 213         return -ENODEV;
 214 }
 215 #endif /* CONFIG_ACPI_HOTPLUG_CPU */
 216
 217 static int acpi_processor_get_info(struct acpi_device *device)
 218 {
 219         union acpi_object object = { 0 };
 220         struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
 221         struct acpi_processor *pr = acpi_driver_data(device);
 222         int device_declaration = 0;
 223         acpi_status status = AE_OK;
 224         static int cpu0_initialized;
 225         unsigned long long value;
 226
 227         acpi_processor_errata();
 228
 229         /*
 230          * Check to see if we have bus mastering arbitration control.  This
 231          * is required for proper C3 usage (to maintain cache coherency).
 232          */
 233         if (acpi_gbl_FADT.pm2_control_block && acpi_gbl_FADT.pm2_control_length) {
 234                 pr->flags.bm_control = 1;
 235                 dev_dbg(&device->dev, "Bus mastering arbitration control present\n");
 236         } else
 237                 dev_dbg(&device->dev, "No bus mastering arbitration control\n");
 238
 239         if (!strcmp(acpi_device_hid(device), ACPI_PROCESSOR_OBJECT_HID)) {
 240                 /* Declared with "Processor" statement; match ProcessorID */
 241                 status = acpi_evaluate_object(pr->handle, NULL, NULL, &buffer);
 242                 if (ACPI_FAILURE(status)) {
 243                         dev_err(&device->dev,
 244                                 "Failed to evaluate processor object (0x%x)\n",
 245                                 status);
 246                         return -ENODEV;
 247                 }
 248
 249                 pr->acpi_id = object.processor.proc_id;
 250         } else {
 251                 /*
 252                  * Declared with "Device" statement; match _UID.
 253                  */
 254                 status = acpi_evaluate_integer(pr->handle, METHOD_NAME__UID,
 255                                                 NULL, &value);
 256                 if (ACPI_FAILURE(status)) {
 257                         dev_err(&device->dev,
 258                                 "Failed to evaluate processor _UID (0x%x)\n",
 259                                 status);
 260                         return -ENODEV;
 261                 }
 262                 device_declaration = 1;
 263                 pr->acpi_id = value;
 264         }
 265
 266         if (acpi_duplicate_processor_id(pr->acpi_id)) {
 267                 if (pr->acpi_id == 0xff)
 268                         dev_info_once(&device->dev,
 269                                 "Entry not well-defined, consider updating BIOS\n");
 270                 else
 271                         dev_err(&device->dev,
 272                                 "Failed to get unique processor _UID (0x%x)\n",
 273                                 pr->acpi_id);
 274                 return -ENODEV;
 275         }
 276
 277         pr->phys_id = acpi_get_phys_id(pr->handle, device_declaration,
 278                                         pr->acpi_id);
 279         if (invalid_phys_cpuid(pr->phys_id))
 280                 dev_dbg(&device->dev, "Failed to get CPU physical ID.\n");
 281
 282         pr->id = acpi_map_cpuid(pr->phys_id, pr->acpi_id);
 283         if (!cpu0_initialized && !acpi_has_cpu_in_madt()) {
 284                 cpu0_initialized = 1;
 285                 /*
 286                  * Handle UP system running SMP kernel, with no CPU
 287                  * entry in MADT
 288                  */
 289                 if (invalid_logical_cpuid(pr->id) && (num_online_cpus() == 1))
 290                         pr->id = 0;
 291         }
 292
 293         /*
 294          *  Extra Processor objects may be enumerated on MP systems with
 295          *  less than the max # of CPUs. They should be ignored _iff
 296          *  they are physically not present.
 297          *
 298          *  NOTE: Even if the processor has a cpuid, it may not be present
 299          *  because cpuid <-> apicid mapping is persistent now.
 300          */
 301         if (invalid_logical_cpuid(pr->id) || !cpu_present(pr->id)) {
 302                 int ret = acpi_processor_hotadd_init(pr);
 303
 304                 if (ret)
 305                         return ret;
 306         }
 307
 308         /*
 309          * On some boxes several processors use the same processor bus id.
 310          * But they are located in different scope. For example:
 311          * \_SB.SCK0.CPU0
 312          * \_SB.SCK1.CPU0
 313          * Rename the processor device bus id. And the new bus id will be
 314          * generated as the following format:
 315          * CPU+CPU ID.
 316          */
 317         sprintf(acpi_device_bid(device), "CPU%X", pr->id);
 318         dev_dbg(&device->dev, "Processor [%d:%d]\n", pr->id, pr->acpi_id);
 319
 320         if (!object.processor.pblk_address)
 321                 dev_dbg(&device->dev, "No PBLK (NULL address)\n");
 322         else if (object.processor.pblk_length != 6)
 323                 dev_err(&device->dev, "Invalid PBLK length [%d]\n",
 324                             object.processor.pblk_length);
 325         else {
 326                 pr->throttling.address = object.processor.pblk_address;
 327                 pr->throttling.duty_offset = acpi_gbl_FADT.duty_offset;
 328                 pr->throttling.duty_width = acpi_gbl_FADT.duty_width;
 329
 330                 pr->pblk = object.processor.pblk_address;
 331         }
 332
 333         /*
 334          * If ACPI describes a slot number for this CPU, we can use it to
 335          * ensure we get the right value in the "physical id" field
 336          * of /proc/cpuinfo
 337          */
 338         status = acpi_evaluate_integer(pr->handle, "_SUN", NULL, &value);
 339         if (ACPI_SUCCESS(status))
 340                 arch_fix_phys_package_id(pr->id, value);
 341
 342         return 0;
 343 }
 344
 345 /*
 346  * Do not put anything in here which needs the core to be online.
 347  * For example MSR access or setting up things which check for cpuinfo_x86
 348  * (cpu_data(cpu)) values, like CPU feature flags, family, model, etc.
 349  * Such things have to be put in and set up by the processor driver's .probe().
 350  */
 351 static DEFINE_PER_CPU(void *, processor_device_array);
 352
 353 static int acpi_processor_add(struct acpi_device *device,
 354                                         const struct acpi_device_id *id)
 355 {
 356         struct acpi_processor *pr;
 357         struct device *dev;
 358         int result = 0;
 359
 360         pr = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL);
 361         if (!pr)
 362                 return -ENOMEM;
 363
 364         if (!zalloc_cpumask_var(&pr->throttling.shared_cpu_map, GFP_KERNEL)) {
 365                 result = -ENOMEM;
 366                 goto err_free_pr;
 367         }
 368
 369         pr->handle = device->handle;
 370         strcpy(acpi_device_name(device), ACPI_PROCESSOR_DEVICE_NAME);
 371         strcpy(acpi_device_class(device), ACPI_PROCESSOR_CLASS);
 372         device->driver_data = pr;
 373
 374         result = acpi_processor_get_info(device);
 375         if (result) /* Processor is not physically present or unavailable */
 376                 return 0;
 377
 378         BUG_ON(pr->id >= nr_cpu_ids);
 379
 380         /*
 381          * Buggy BIOS check.
 382          * ACPI id of processors can be reported wrongly by the BIOS.
 383          * Don't trust it blindly
 384          */
 385         if (per_cpu(processor_device_array, pr->id) != NULL &&
 386             per_cpu(processor_device_array, pr->id) != device) {
 387                 dev_warn(&device->dev,
 388                         "BIOS reported wrong ACPI id %d for the processor\n",
 389                         pr->id);
 390                 /* Give up, but do not abort the namespace scan. */
 391                 goto err;
 392         }
 393         /*
 394          * processor_device_array is not cleared on errors to allow buggy BIOS
 395          * checks.
 396          */
 397         per_cpu(processor_device_array, pr->id) = device;
 398         per_cpu(processors, pr->id) = pr;
 399
 400         dev = get_cpu_device(pr->id);
 401         if (!dev) {
 402                 result = -ENODEV;
 403                 goto err;
 404         }
 405
 406         result = acpi_bind_one(dev, device);
 407         if (result)
 408                 goto err;
 409
 410         pr->dev = dev;
 411
 412         /* Trigger the processor driver's .probe() if present. */
 413         if (device_attach(dev) >= 0)
 414                 return 1;
 415
 416         dev_err(dev, "Processor driver could not be attached\n");
 417         acpi_unbind_one(dev);
 418
 419  err:
 420         free_cpumask_var(pr->throttling.shared_cpu_map);
 421         device->driver_data = NULL;
 422         per_cpu(processors, pr->id) = NULL;
 423  err_free_pr:
 424         kfree(pr);
 425         return result;
 426 }
 427
 428 #ifdef CONFIG_ACPI_HOTPLUG_CPU
 429 /* Removal */
 430 static void acpi_processor_remove(struct acpi_device *device)
 431 {
 432         struct acpi_processor *pr;
 433
 434         if (!device || !acpi_driver_data(device))
 435                 return;
 436
 437         pr = acpi_driver_data(device);
 438         if (pr->id >= nr_cpu_ids)
 439                 goto out;
 440
 441         /*
 442          * The only reason why we ever get here is CPU hot-removal.  The CPU is
 443          * already offline and the ACPI device removal locking prevents it from
 444          * being put back online at this point.
 445          *
 446          * Unbind the driver from the processor device and detach it from the
 447          * ACPI companion object.
 448          */
 449         device_release_driver(pr->dev);
 450         acpi_unbind_one(pr->dev);
 451
 452         /* Clean up. */
 453         per_cpu(processor_device_array, pr->id) = NULL;
 454         per_cpu(processors, pr->id) = NULL;
 455
 456         cpu_maps_update_begin();
 457         cpus_write_lock();
 458
 459         /* Remove the CPU. */
 460         arch_unregister_cpu(pr->id);
 461         acpi_unmap_cpu(pr->id);
 462
 463         cpus_write_unlock();
 464         cpu_maps_update_done();
 465
 466         try_offline_node(cpu_to_node(pr->id));
 467
 468  out:
 469         free_cpumask_var(pr->throttling.shared_cpu_map);
 470         kfree(pr);
 471 }
 472 #endif /* CONFIG_ACPI_HOTPLUG_CPU */
 473
 474 #ifdef CONFIG_X86
 475 static bool acpi_hwp_native_thermal_lvt_set;
 476 static acpi_status __init acpi_hwp_native_thermal_lvt_osc(acpi_handle handle,
 477                                                           u32 lvl,
 478                                                           void *context,
 479                                                           void **rv)
 480 {
 481         u8 sb_uuid_str[] = "4077A616-290C-47BE-9EBD-D87058713953";
 482         u32 capbuf[2];
 483         struct acpi_osc_context osc_context = {
 484                 .uuid_str = sb_uuid_str,
 485                 .rev = 1,
 486                 .cap.length = 8,
 487                 .cap.pointer = capbuf,
 488         };
 489
 490         if (acpi_hwp_native_thermal_lvt_set)
 491                 return AE_CTRL_TERMINATE;
 492
 493         capbuf[0] = 0x0000;
 494         capbuf[1] = 0x1000; /* set bit 12 */
 495
 496         if (ACPI_SUCCESS(acpi_run_osc(handle, &osc_context))) {
 497                 if (osc_context.ret.pointer && osc_context.ret.length > 1) {
 498                         u32 *capbuf_ret = osc_context.ret.pointer;
 499
 500                         if (capbuf_ret[1] & 0x1000) {
 501                                 acpi_handle_info(handle,
 502                                         "_OSC native thermal LVT Acked\n");
 503                                 acpi_hwp_native_thermal_lvt_set = true;
 504                         }
 505                 }
 506                 kfree(osc_context.ret.pointer);
 507         }
 508
 509         return AE_OK;
 510 }
 511
 512 void __init acpi_early_processor_osc(void)
 513 {
 514         if (boot_cpu_has(X86_FEATURE_HWP)) {
 515                 acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
 516                                     ACPI_UINT32_MAX,
 517                                     acpi_hwp_native_thermal_lvt_osc,
 518                                     NULL, NULL, NULL);
 519                 acpi_get_devices(ACPI_PROCESSOR_DEVICE_HID,
 520                                  acpi_hwp_native_thermal_lvt_osc,
 521                                  NULL, NULL);
 522         }
 523 }
 524 #endif
 525
 526 /*
 527  * The following ACPI IDs are known to be suitable for representing as
 528  * processor devices.
 529  */
 530 static const struct acpi_device_id processor_device_ids[] = {
 531
 532         { ACPI_PROCESSOR_OBJECT_HID, },
 533         { ACPI_PROCESSOR_DEVICE_HID, },
 534
 535         { }
 536 };
 537
 538 static struct acpi_scan_handler processor_handler = {
 539         .ids = processor_device_ids,
 540         .attach = acpi_processor_add,
 541 #ifdef CONFIG_ACPI_HOTPLUG_CPU
 542         .detach = acpi_processor_remove,
 543 #endif
 544         .hotplug = {
 545                 .enabled = true,
 546         },
 547 };
 548
 549 static int acpi_processor_container_attach(struct acpi_device *dev,
 550                                            const struct acpi_device_id *id)
 551 {
 552         return 1;
 553 }
 554
 555 static const struct acpi_device_id processor_container_ids[] = {
 556         { ACPI_PROCESSOR_CONTAINER_HID, },
 557         { }
 558 };
 559
 560 static struct acpi_scan_handler processor_container_handler = {
 561         .ids = processor_container_ids,
 562         .attach = acpi_processor_container_attach,
 563 };
 564
 565 /* The number of the unique processor IDs */
 566 static int nr_unique_ids __initdata;
 567
 568 /* The number of the duplicate processor IDs */
 569 static int nr_duplicate_ids;
 570
 571 /* Used to store the unique processor IDs */
 572 static int unique_processor_ids[] __initdata = {
 573         [0 ... NR_CPUS - 1] = -1,
 574 };
 575
 576 /* Used to store the duplicate processor IDs */
 577 static int duplicate_processor_ids[] = {
 578         [0 ... NR_CPUS - 1] = -1,
 579 };
 580
 581 static void __init processor_validated_ids_update(int proc_id)
 582 {
 583         int i;
 584
 585         if (nr_unique_ids == NR_CPUS||nr_duplicate_ids == NR_CPUS)
 586                 return;
 587
 588         /*
 589          * Firstly, compare the proc_id with duplicate IDs, if the proc_id is
 590          * already in the IDs, do nothing.
 591          */
 592         for (i = 0; i < nr_duplicate_ids; i++) {
 593                 if (duplicate_processor_ids[i] == proc_id)
 594                         return;
 595         }
 596
 597         /*
 598          * Secondly, compare the proc_id with unique IDs, if the proc_id is in
 599          * the IDs, put it in the duplicate IDs.
 600          */
 601         for (i = 0; i < nr_unique_ids; i++) {
 602                 if (unique_processor_ids[i] == proc_id) {
 603                         duplicate_processor_ids[nr_duplicate_ids] = proc_id;
 604                         nr_duplicate_ids++;
 605                         return;
 606                 }
 607         }
 608
 609         /*
 610          * Lastly, the proc_id is a unique ID, put it in the unique IDs.
 611          */
 612         unique_processor_ids[nr_unique_ids] = proc_id;
 613         nr_unique_ids++;
 614 }
 615
 616 static acpi_status __init acpi_processor_ids_walk(acpi_handle handle,
 617                                                   u32 lvl,
 618                                                   void *context,
 619                                                   void **rv)
 620 {
 621         acpi_status status;
 622         acpi_object_type acpi_type;
 623         unsigned long long uid;
 624         union acpi_object object = { 0 };
 625         struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
 626
 627         status = acpi_get_type(handle, &acpi_type);
 628         if (ACPI_FAILURE(status))
 629                 return status;
 630
 631         switch (acpi_type) {
 632         case ACPI_TYPE_PROCESSOR:
 633                 status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
 634                 if (ACPI_FAILURE(status))
 635                         goto err;
 636                 uid = object.processor.proc_id;
 637                 break;
 638
 639         case ACPI_TYPE_DEVICE:
 640                 status = acpi_evaluate_integer(handle, "_UID", NULL, &uid);
 641                 if (ACPI_FAILURE(status))
 642                         goto err;
 643                 break;
 644         default:
 645                 goto err;
 646         }
 647
 648         processor_validated_ids_update(uid);
 649         return AE_OK;
 650
 651 err:
 652         /* Exit on error, but don't abort the namespace walk */
 653         acpi_handle_info(handle, "Invalid processor object\n");
 654         return AE_OK;
 655
 656 }
 657
 658 static void __init acpi_processor_check_duplicates(void)
 659 {
 660         /* check the correctness for all processors in ACPI namespace */
 661         acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
 662                                                 ACPI_UINT32_MAX,
 663                                                 acpi_processor_ids_walk,
 664                                                 NULL, NULL, NULL);
 665         acpi_get_devices(ACPI_PROCESSOR_DEVICE_HID, acpi_processor_ids_walk,
 666                                                 NULL, NULL);
 667 }
 668
 669 bool acpi_duplicate_processor_id(int proc_id)
 670 {
 671         int i;
 672
 673         /*
 674          * compare the proc_id with duplicate IDs, if the proc_id is already
 675          * in the duplicate IDs, return true, otherwise, return false.
 676          */
 677         for (i = 0; i < nr_duplicate_ids; i++) {
 678                 if (duplicate_processor_ids[i] == proc_id)
 679                         return true;
 680         }
 681         return false;
 682 }
 683
 684 void __init acpi_processor_init(void)
 685 {
 686         acpi_processor_check_duplicates();
 687         acpi_scan_add_handler_with_hotplug(&processor_handler, "processor");
 688         acpi_scan_add_handler(&processor_container_handler);
 689 }
 690
 691 #ifdef CONFIG_ACPI_PROCESSOR_CSTATE
 692 /**
 693  * acpi_processor_claim_cst_control - Request _CST control from the platform.
 694  */
 695 bool acpi_processor_claim_cst_control(void)
 696 {
 697         static bool cst_control_claimed;
 698         acpi_status status;
 699
 700         if (!acpi_gbl_FADT.cst_control || cst_control_claimed)
 701                 return true;
 702
 703         status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
 704                                     acpi_gbl_FADT.cst_control, 8);
 705         if (ACPI_FAILURE(status)) {
 706                 pr_warn("ACPI: Failed to claim processor _CST control\n");
 707                 return false;
 708         }
 709
 710         cst_control_claimed = true;
 711         return true;
 712 }
 713 EXPORT_SYMBOL_GPL(acpi_processor_claim_cst_control);
 714
 715 /**
 716  * acpi_processor_evaluate_cst - Evaluate the processor _CST control method.
 717  * @handle: ACPI handle of the processor object containing the _CST.
 718  * @cpu: The numeric ID of the target CPU.
 719  * @info: Object write the C-states information into.
 720  *
 721  * Extract the C-state information for the given CPU from the output of the _CST
 722  * control method under the corresponding ACPI processor object (or processor
 723  * device object) and populate @info with it.
 724  *
 725  * If any ACPI_ADR_SPACE_FIXED_HARDWARE C-states are found, invoke
 726  * acpi_processor_ffh_cstate_probe() to verify them and update the
 727  * cpu_cstate_entry data for @cpu.
 728  */
 729 int acpi_processor_evaluate_cst(acpi_handle handle, u32 cpu,
 730                                 struct acpi_processor_power *info)
 731 {
 732         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 733         union acpi_object *cst;
 734         acpi_status status;
 735         u64 count;
 736         int last_index = 0;
 737         int i, ret = 0;
 738
 739         status = acpi_evaluate_object(handle, "_CST", NULL, &buffer);
 740         if (ACPI_FAILURE(status)) {
 741                 acpi_handle_debug(handle, "No _CST\n");
 742                 return -ENODEV;
 743         }
 744
 745         cst = buffer.pointer;
 746
 747         /* There must be at least 2 elements. */
 748         if (!cst || cst->type != ACPI_TYPE_PACKAGE || cst->package.count < 2) {
 749                 acpi_handle_warn(handle, "Invalid _CST output\n");
 750                 ret = -EFAULT;
 751                 goto end;
 752         }
 753
 754         count = cst->package.elements[0].integer.value;
 755
 756         /* Validate the number of C-states. */
 757         if (count < 1 || count != cst->package.count - 1) {
 758                 acpi_handle_warn(handle, "Inconsistent _CST data\n");
 759                 ret = -EFAULT;
 760                 goto end;
 761         }
 762
 763         for (i = 1; i <= count; i++) {
 764                 union acpi_object *element;
 765                 union acpi_object *obj;
 766                 struct acpi_power_register *reg;
 767                 struct acpi_processor_cx cx;
 768
 769                 /*
 770                  * If there is not enough space for all C-states, skip the
 771                  * excess ones and log a warning.
 772                  */
 773                 if (last_index >= ACPI_PROCESSOR_MAX_POWER - 1) {
 774                         acpi_handle_warn(handle,
 775                                          "No room for more idle states (limit: %d)\n",
 776                                          ACPI_PROCESSOR_MAX_POWER - 1);
 777                         break;
 778                 }
 779
 780                 memset(&cx, 0, sizeof(cx));
 781
 782                 element = &cst->package.elements[i];
 783                 if (element->type != ACPI_TYPE_PACKAGE) {
 784                         acpi_handle_info(handle, "_CST C%d type(%x) is not package, skip...\n",
 785                                          i, element->type);
 786                         continue;
 787                 }
 788
 789                 if (element->package.count != 4) {
 790                         acpi_handle_info(handle, "_CST C%d package count(%d) is not 4, skip...\n",
 791                                          i, element->package.count);
 792                         continue;
 793                 }
 794
 795                 obj = &element->package.elements[0];
 796
 797                 if (obj->type != ACPI_TYPE_BUFFER) {
 798                         acpi_handle_info(handle, "_CST C%d package element[0] type(%x) is not buffer, skip...\n",
 799                                          i, obj->type);
 800                         continue;
 801                 }
 802
 803                 reg = (struct acpi_power_register *)obj->buffer.pointer;
 804
 805                 obj = &element->package.elements[1];
 806                 if (obj->type != ACPI_TYPE_INTEGER) {
 807                         acpi_handle_info(handle, "_CST C[%d] package element[1] type(%x) is not integer, skip...\n",
 808                                          i, obj->type);
 809                         continue;
 810                 }
 811
 812                 cx.type = obj->integer.value;
 813                 /*
 814                  * There are known cases in which the _CST output does not
 815                  * contain C1, so if the type of the first state found is not
 816                  * C1, leave an empty slot for C1 to be filled in later.
 817                  */
 818                 if (i == 1 && cx.type != ACPI_STATE_C1)
 819                         last_index = 1;
 820
 821                 cx.address = reg->address;
 822                 cx.index = last_index + 1;
 823
 824                 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
 825                         if (!acpi_processor_ffh_cstate_probe(cpu, &cx, reg)) {
 826                                 /*
 827                                  * In the majority of cases _CST describes C1 as
 828                                  * a FIXED_HARDWARE C-state, but if the command
 829                                  * line forbids using MWAIT, use CSTATE_HALT for
 830                                  * C1 regardless.
 831                                  */
 832                                 if (cx.type == ACPI_STATE_C1 &&
 833                                     boot_option_idle_override == IDLE_NOMWAIT) {
 834                                         cx.entry_method = ACPI_CSTATE_HALT;
 835                                         snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 836                                 } else {
 837                                         cx.entry_method = ACPI_CSTATE_FFH;
 838                                 }
 839                         } else if (cx.type == ACPI_STATE_C1) {
 840                                 /*
 841                                  * In the special case of C1, FIXED_HARDWARE can
 842                                  * be handled by executing the HLT instruction.
 843                                  */
 844                                 cx.entry_method = ACPI_CSTATE_HALT;
 845                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 846                         } else {
 847                                 acpi_handle_info(handle, "_CST C%d declares FIXED_HARDWARE C-state but not supported in hardware, skip...\n",
 848                                                  i);
 849                                 continue;
 850                         }
 851                 } else if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_IO) {
 852                         cx.entry_method = ACPI_CSTATE_SYSTEMIO;
 853                         snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
 854                                  cx.address);
 855                 } else {
 856                         acpi_handle_info(handle, "_CST C%d space_id(%x) neither FIXED_HARDWARE nor SYSTEM_IO, skip...\n",
 857                                          i, reg->space_id);
 858                         continue;
 859                 }
 860
 861                 if (cx.type == ACPI_STATE_C1)
 862                         cx.valid = 1;
 863
 864                 obj = &element->package.elements[2];
 865                 if (obj->type != ACPI_TYPE_INTEGER) {
 866                         acpi_handle_info(handle, "_CST C%d package element[2] type(%x) not integer, skip...\n",
 867                                          i, obj->type);
 868                         continue;
 869                 }
 870
 871                 cx.latency = obj->integer.value;
 872
 873                 obj = &element->package.elements[3];
 874                 if (obj->type != ACPI_TYPE_INTEGER) {
 875                         acpi_handle_info(handle, "_CST C%d package element[3] type(%x) not integer, skip...\n",
 876                                          i, obj->type);
 877                         continue;
 878                 }
 879
 880                 memcpy(&info->states[++last_index], &cx, sizeof(cx));
 881         }
 882
 883         acpi_handle_info(handle, "Found %d idle states\n", last_index);
 884
 885         info->count = last_index;
 886
 887 end:
 888         kfree(buffer.pointer);
 889
 890         return ret;
 891 }
 892 EXPORT_SYMBOL_GPL(acpi_processor_evaluate_cst);
 893 #endif /* CONFIG_ACPI_PROCESSOR_CSTATE */