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 #define pr_fmt(fmt) "ACPI: " fmt
  13
  14 #include <linux/acpi.h>
  15 #include <linux/cpu.h>
  16 #include <linux/device.h>
  17 #include <linux/dmi.h>
  18 #include <linux/kernel.h>
  19 #include <linux/module.h>
  20 #include <linux/pci.h>
  21 #include <linux/platform_device.h>
  22
  23 #include <acpi/processor.h>
  24
  25 #include <asm/cpu.h>
  26
  27 #include <xen/xen.h>
  28
  29 #include "internal.h"
  30
  31 DEFINE_PER_CPU(struct acpi_processor *, processors);
  32 EXPORT_PER_CPU_SYMBOL(processors);
  33
  34 /* Errata Handling */
  35 struct acpi_processor_errata errata __read_mostly;
  36 EXPORT_SYMBOL_GPL(errata);
  37
  38 static int acpi_processor_errata_piix4(struct pci_dev *dev)
  39 {
  40         u8 value1 = 0;
  41         u8 value2 = 0;
  42
  43
  44         if (!dev)
  45                 return -EINVAL;
  46
  47         /*
  48          * Note that 'dev' references the PIIX4 ACPI Controller.
  49          */
  50
  51         switch (dev->revision) {
  52         case 0:
  53                 dev_dbg(&dev->dev, "Found PIIX4 A-step\n");
  54                 break;
  55         case 1:
  56                 dev_dbg(&dev->dev, "Found PIIX4 B-step\n");
  57                 break;
  58         case 2:
  59                 dev_dbg(&dev->dev, "Found PIIX4E\n");
  60                 break;
  61         case 3:
  62                 dev_dbg(&dev->dev, "Found PIIX4M\n");
  63                 break;
  64         default:
  65                 dev_dbg(&dev->dev, "Found unknown PIIX4\n");
  66                 break;
  67         }
  68
  69         switch (dev->revision) {
  70
  71         case 0:         /* PIIX4 A-step */
  72         case 1:         /* PIIX4 B-step */
  73                 /*
  74                  * See specification changes #13 ("Manual Throttle Duty Cycle")
  75                  * and #14 ("Enabling and Disabling Manual Throttle"), plus
  76                  * erratum #5 ("STPCLK# Deassertion Time") from the January
  77                  * 2002 PIIX4 specification update.  Applies to only older
  78                  * PIIX4 models.
  79                  */
  80                 errata.piix4.throttle = 1;
  81                 fallthrough;
  82
  83         case 2:         /* PIIX4E */
  84         case 3:         /* PIIX4M */
  85                 /*
  86                  * See erratum #18 ("C3 Power State/BMIDE and Type-F DMA
  87                  * Livelock") from the January 2002 PIIX4 specification update.
  88                  * Applies to all PIIX4 models.
  89                  */
  90
  91                 /*
  92                  * BM-IDE
  93                  * ------
  94                  * Find the PIIX4 IDE Controller and get the Bus Master IDE
  95                  * Status register address.  We'll use this later to read
  96                  * each IDE controller's DMA status to make sure we catch all
  97                  * DMA activity.
  98                  */
  99                 dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
 100                                      PCI_DEVICE_ID_INTEL_82371AB,
 101                                      PCI_ANY_ID, PCI_ANY_ID, NULL);
 102                 if (dev) {
 103                         errata.piix4.bmisx = pci_resource_start(dev, 4);
 104                         pci_dev_put(dev);
 105                 }
 106
 107                 /*
 108                  * Type-F DMA
 109                  * ----------
 110                  * Find the PIIX4 ISA Controller and read the Motherboard
 111                  * DMA controller's status to see if Type-F (Fast) DMA mode
 112                  * is enabled (bit 7) on either channel.  Note that we'll
 113                  * disable C3 support if this is enabled, as some legacy
 114                  * devices won't operate well if fast DMA is disabled.
 115                  */
 116                 dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
 117                                      PCI_DEVICE_ID_INTEL_82371AB_0,
 118                                      PCI_ANY_ID, PCI_ANY_ID, NULL);
 119                 if (dev) {
 120                         pci_read_config_byte(dev, 0x76, &value1);
 121                         pci_read_config_byte(dev, 0x77, &value2);
 122                         if ((value1 & 0x80) || (value2 & 0x80))
 123                                 errata.piix4.fdma = 1;
 124                         pci_dev_put(dev);
 125                 }
 126
 127                 break;
 128         }
 129
 130         if (errata.piix4.bmisx)
 131                 dev_dbg(&dev->dev, "Bus master activity detection (BM-IDE) erratum enabled\n");
 132         if (errata.piix4.fdma)
 133                 dev_dbg(&dev->dev, "Type-F DMA livelock erratum (C3 disabled)\n");
 134
 135         return 0;
 136 }
 137
 138 static int acpi_processor_errata(void)
 139 {
 140         int result = 0;
 141         struct pci_dev *dev = NULL;
 142
 143         /*
 144          * PIIX4
 145          */
 146         dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
 147                              PCI_DEVICE_ID_INTEL_82371AB_3, PCI_ANY_ID,
 148                              PCI_ANY_ID, NULL);
 149         if (dev) {
 150                 result = acpi_processor_errata_piix4(dev);
 151                 pci_dev_put(dev);
 152         }
 153
 154         return result;
 155 }
 156
 157 /* Create a platform device to represent a CPU frequency control mechanism. */
 158 static void cpufreq_add_device(const char *name)
 159 {
 160         struct platform_device *pdev;
 161
 162         pdev = platform_device_register_simple(name, PLATFORM_DEVID_NONE, NULL, 0);
 163         if (IS_ERR(pdev))
 164                 pr_info("%s device creation failed: %pe\n", name, pdev);
 165 }
 166
 167 #ifdef CONFIG_X86
 168 /* Check presence of Processor Clocking Control by searching for \_SB.PCCH. */
 169 static void __init acpi_pcc_cpufreq_init(void)
 170 {
 171         acpi_status status;
 172         acpi_handle handle;
 173
 174         status = acpi_get_handle(NULL, "\\_SB", &handle);
 175         if (ACPI_FAILURE(status))
 176                 return;
 177
 178         if (acpi_has_method(handle, "PCCH"))
 179                 cpufreq_add_device("pcc-cpufreq");
 180 }
 181 #else
 182 static void __init acpi_pcc_cpufreq_init(void) {}
 183 #endif /* CONFIG_X86 */
 184
 185 /* Initialization */
 186 #ifdef CONFIG_ACPI_HOTPLUG_CPU
 187 static int acpi_processor_hotadd_init(struct acpi_processor *pr)
 188 {
 189         unsigned long long sta;
 190         acpi_status status;
 191         int ret;
 192
 193         if (invalid_phys_cpuid(pr->phys_id))
 194                 return -ENODEV;
 195
 196         status = acpi_evaluate_integer(pr->handle, "_STA", NULL, &sta);
 197         if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_PRESENT))
 198                 return -ENODEV;
 199
 200         cpu_maps_update_begin();
 201         cpus_write_lock();
 202
 203         ret = acpi_map_cpu(pr->handle, pr->phys_id, pr->acpi_id, &pr->id);
 204         if (ret)
 205                 goto out;
 206
 207         ret = arch_register_cpu(pr->id);
 208         if (ret) {
 209                 acpi_unmap_cpu(pr->id);
 210                 goto out;
 211         }
 212
 213         /*
 214          * CPU got hot-added, but cpu_data is not initialized yet.  Set a flag
 215          * to delay cpu_idle/throttling initialization and do it when the CPU
 216          * gets online for the first time.
 217          */
 218         pr_info("CPU%d has been hot-added\n", pr->id);
 219         pr->flags.need_hotplug_init = 1;
 220
 221 out:
 222         cpus_write_unlock();
 223         cpu_maps_update_done();
 224         return ret;
 225 }
 226 #else
 227 static inline int acpi_processor_hotadd_init(struct acpi_processor *pr)
 228 {
 229         return -ENODEV;
 230 }
 231 #endif /* CONFIG_ACPI_HOTPLUG_CPU */
 232
 233 static int acpi_processor_get_info(struct acpi_device *device)
 234 {
 235         union acpi_object object = { 0 };
 236         struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
 237         struct acpi_processor *pr = acpi_driver_data(device);
 238         int device_declaration = 0;
 239         acpi_status status = AE_OK;
 240         static int cpu0_initialized;
 241         unsigned long long value;
 242
 243         acpi_processor_errata();
 244
 245         /*
 246          * Check to see if we have bus mastering arbitration control.  This
 247          * is required for proper C3 usage (to maintain cache coherency).
 248          */
 249         if (acpi_gbl_FADT.pm2_control_block && acpi_gbl_FADT.pm2_control_length) {
 250                 pr->flags.bm_control = 1;
 251                 dev_dbg(&device->dev, "Bus mastering arbitration control present\n");
 252         } else
 253                 dev_dbg(&device->dev, "No bus mastering arbitration control\n");
 254
 255         if (!strcmp(acpi_device_hid(device), ACPI_PROCESSOR_OBJECT_HID)) {
 256                 /* Declared with "Processor" statement; match ProcessorID */
 257                 status = acpi_evaluate_object(pr->handle, NULL, NULL, &buffer);
 258                 if (ACPI_FAILURE(status)) {
 259                         dev_err(&device->dev,
 260                                 "Failed to evaluate processor object (0x%x)\n",
 261                                 status);
 262                         return -ENODEV;
 263                 }
 264
 265                 pr->acpi_id = object.processor.proc_id;
 266         } else {
 267                 /*
 268                  * Declared with "Device" statement; match _UID.
 269                  */
 270                 status = acpi_evaluate_integer(pr->handle, METHOD_NAME__UID,
 271                                                 NULL, &value);
 272                 if (ACPI_FAILURE(status)) {
 273                         dev_err(&device->dev,
 274                                 "Failed to evaluate processor _UID (0x%x)\n",
 275                                 status);
 276                         return -ENODEV;
 277                 }
 278                 device_declaration = 1;
 279                 pr->acpi_id = value;
 280         }
 281
 282         if (acpi_duplicate_processor_id(pr->acpi_id)) {
 283                 if (pr->acpi_id == 0xff)
 284                         dev_info_once(&device->dev,
 285                                 "Entry not well-defined, consider updating BIOS\n");
 286                 else
 287                         dev_err(&device->dev,
 288                                 "Failed to get unique processor _UID (0x%x)\n",
 289                                 pr->acpi_id);
 290                 return -ENODEV;
 291         }
 292
 293         pr->phys_id = acpi_get_phys_id(pr->handle, device_declaration,
 294                                         pr->acpi_id);
 295         if (invalid_phys_cpuid(pr->phys_id))
 296                 dev_dbg(&device->dev, "Failed to get CPU physical ID.\n");
 297
 298         pr->id = acpi_map_cpuid(pr->phys_id, pr->acpi_id);
 299         if (!cpu0_initialized) {
 300                 cpu0_initialized = 1;
 301                 /*
 302                  * Handle UP system running SMP kernel, with no CPU
 303                  * entry in MADT
 304                  */
 305                 if (!acpi_has_cpu_in_madt() && invalid_logical_cpuid(pr->id) &&
 306                     (num_online_cpus() == 1))
 307                         pr->id = 0;
 308                 /*
 309                  * Check availability of Processor Performance Control by
 310                  * looking at the presence of the _PCT object under the first
 311                  * processor definition.
 312                  */
 313                 if (acpi_has_method(pr->handle, "_PCT"))
 314                         cpufreq_add_device("acpi-cpufreq");
 315         }
 316
 317         /*
 318          *  Extra Processor objects may be enumerated on MP systems with
 319          *  less than the max # of CPUs. They should be ignored _iff
 320          *  they are physically not present.
 321          *
 322          *  NOTE: Even if the processor has a cpuid, it may not be present
 323          *  because cpuid <-> apicid mapping is persistent now.
 324          */
 325         if (invalid_logical_cpuid(pr->id) || !cpu_present(pr->id)) {
 326                 int ret = acpi_processor_hotadd_init(pr);
 327
 328                 if (ret)
 329                         return ret;
 330         }
 331
 332         /*
 333          * On some boxes several processors use the same processor bus id.
 334          * But they are located in different scope. For example:
 335          * \_SB.SCK0.CPU0
 336          * \_SB.SCK1.CPU0
 337          * Rename the processor device bus id. And the new bus id will be
 338          * generated as the following format:
 339          * CPU+CPU ID.
 340          */
 341         sprintf(acpi_device_bid(device), "CPU%X", pr->id);
 342         dev_dbg(&device->dev, "Processor [%d:%d]\n", pr->id, pr->acpi_id);
 343
 344         if (!object.processor.pblk_address)
 345                 dev_dbg(&device->dev, "No PBLK (NULL address)\n");
 346         else if (object.processor.pblk_length != 6)
 347                 dev_err(&device->dev, "Invalid PBLK length [%d]\n",
 348                             object.processor.pblk_length);
 349         else {
 350                 pr->throttling.address = object.processor.pblk_address;
 351                 pr->throttling.duty_offset = acpi_gbl_FADT.duty_offset;
 352                 pr->throttling.duty_width = acpi_gbl_FADT.duty_width;
 353
 354                 pr->pblk = object.processor.pblk_address;
 355         }
 356
 357         /*
 358          * If ACPI describes a slot number for this CPU, we can use it to
 359          * ensure we get the right value in the "physical id" field
 360          * of /proc/cpuinfo
 361          */
 362         status = acpi_evaluate_integer(pr->handle, "_SUN", NULL, &value);
 363         if (ACPI_SUCCESS(status))
 364                 arch_fix_phys_package_id(pr->id, value);
 365
 366         return 0;
 367 }
 368
 369 /*
 370  * Do not put anything in here which needs the core to be online.
 371  * For example MSR access or setting up things which check for cpuinfo_x86
 372  * (cpu_data(cpu)) values, like CPU feature flags, family, model, etc.
 373  * Such things have to be put in and set up by the processor driver's .probe().
 374  */
 375 static DEFINE_PER_CPU(void *, processor_device_array);
 376
 377 static int acpi_processor_add(struct acpi_device *device,
 378                                         const struct acpi_device_id *id)
 379 {
 380         struct acpi_processor *pr;
 381         struct device *dev;
 382         int result = 0;
 383
 384         if (!acpi_device_is_enabled(device))
 385                 return -ENODEV;
 386
 387         pr = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL);
 388         if (!pr)
 389                 return -ENOMEM;
 390
 391         if (!zalloc_cpumask_var(&pr->throttling.shared_cpu_map, GFP_KERNEL)) {
 392                 result = -ENOMEM;
 393                 goto err_free_pr;
 394         }
 395
 396         pr->handle = device->handle;
 397         strcpy(acpi_device_name(device), ACPI_PROCESSOR_DEVICE_NAME);
 398         strcpy(acpi_device_class(device), ACPI_PROCESSOR_CLASS);
 399         device->driver_data = pr;
 400
 401         result = acpi_processor_get_info(device);
 402         if (result) /* Processor is not physically present or unavailable */
 403                 return 0;
 404
 405         BUG_ON(pr->id >= nr_cpu_ids);
 406
 407         /*
 408          * Buggy BIOS check.
 409          * ACPI id of processors can be reported wrongly by the BIOS.
 410          * Don't trust it blindly
 411          */
 412         if (per_cpu(processor_device_array, pr->id) != NULL &&
 413             per_cpu(processor_device_array, pr->id) != device) {
 414                 dev_warn(&device->dev,
 415                         "BIOS reported wrong ACPI id %d for the processor\n",
 416                         pr->id);
 417                 /* Give up, but do not abort the namespace scan. */
 418                 goto err;
 419         }
 420         /*
 421          * processor_device_array is not cleared on errors to allow buggy BIOS
 422          * checks.
 423          */
 424         per_cpu(processor_device_array, pr->id) = device;
 425         per_cpu(processors, pr->id) = pr;
 426
 427         dev = get_cpu_device(pr->id);
 428         if (!dev) {
 429                 result = -ENODEV;
 430                 goto err;
 431         }
 432
 433         result = acpi_bind_one(dev, device);
 434         if (result)
 435                 goto err;
 436
 437         pr->dev = dev;
 438
 439         /* Trigger the processor driver's .probe() if present. */
 440         if (device_attach(dev) >= 0)
 441                 return 1;
 442
 443         dev_err(dev, "Processor driver could not be attached\n");
 444         acpi_unbind_one(dev);
 445
 446  err:
 447         free_cpumask_var(pr->throttling.shared_cpu_map);
 448         device->driver_data = NULL;
 449         per_cpu(processors, pr->id) = NULL;
 450  err_free_pr:
 451         kfree(pr);
 452         return result;
 453 }
 454
 455 #ifdef CONFIG_ACPI_HOTPLUG_CPU
 456 /* Removal */
 457 static void acpi_processor_remove(struct acpi_device *device)
 458 {
 459         struct acpi_processor *pr;
 460
 461         if (!device || !acpi_driver_data(device))
 462                 return;
 463
 464         pr = acpi_driver_data(device);
 465         if (pr->id >= nr_cpu_ids)
 466                 goto out;
 467
 468         /*
 469          * The only reason why we ever get here is CPU hot-removal.  The CPU is
 470          * already offline and the ACPI device removal locking prevents it from
 471          * being put back online at this point.
 472          *
 473          * Unbind the driver from the processor device and detach it from the
 474          * ACPI companion object.
 475          */
 476         device_release_driver(pr->dev);
 477         acpi_unbind_one(pr->dev);
 478
 479         /* Clean up. */
 480         per_cpu(processor_device_array, pr->id) = NULL;
 481         per_cpu(processors, pr->id) = NULL;
 482
 483         cpu_maps_update_begin();
 484         cpus_write_lock();
 485
 486         /* Remove the CPU. */
 487         arch_unregister_cpu(pr->id);
 488         acpi_unmap_cpu(pr->id);
 489
 490         cpus_write_unlock();
 491         cpu_maps_update_done();
 492
 493         try_offline_node(cpu_to_node(pr->id));
 494
 495  out:
 496         free_cpumask_var(pr->throttling.shared_cpu_map);
 497         kfree(pr);
 498 }
 499 #endif /* CONFIG_ACPI_HOTPLUG_CPU */
 500
 501 #ifdef CONFIG_ARCH_MIGHT_HAVE_ACPI_PDC
 502 bool __init processor_physically_present(acpi_handle handle)
 503 {
 504         int cpuid, type;
 505         u32 acpi_id;
 506         acpi_status status;
 507         acpi_object_type acpi_type;
 508         unsigned long long tmp;
 509         union acpi_object object = {};
 510         struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
 511
 512         status = acpi_get_type(handle, &acpi_type);
 513         if (ACPI_FAILURE(status))
 514                 return false;
 515
 516         switch (acpi_type) {
 517         case ACPI_TYPE_PROCESSOR:
 518                 status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
 519                 if (ACPI_FAILURE(status))
 520                         return false;
 521                 acpi_id = object.processor.proc_id;
 522                 break;
 523         case ACPI_TYPE_DEVICE:
 524                 status = acpi_evaluate_integer(handle, METHOD_NAME__UID,
 525                                                NULL, &tmp);
 526                 if (ACPI_FAILURE(status))
 527                         return false;
 528                 acpi_id = tmp;
 529                 break;
 530         default:
 531                 return false;
 532         }
 533
 534         if (xen_initial_domain())
 535                 /*
 536                  * When running as a Xen dom0 the number of processors Linux
 537                  * sees can be different from the real number of processors on
 538                  * the system, and we still need to execute _PDC or _OSC for
 539                  * all of them.
 540                  */
 541                 return xen_processor_present(acpi_id);
 542
 543         type = (acpi_type == ACPI_TYPE_DEVICE) ? 1 : 0;
 544         cpuid = acpi_get_cpuid(handle, type, acpi_id);
 545
 546         return !invalid_logical_cpuid(cpuid);
 547 }
 548
 549 /* vendor specific UUID indicating an Intel platform */
 550 static u8 sb_uuid_str[] = "4077A616-290C-47BE-9EBD-D87058713953";
 551
 552 static acpi_status __init acpi_processor_osc(acpi_handle handle, u32 lvl,
 553                                              void *context, void **rv)
 554 {
 555         u32 capbuf[2] = {};
 556         struct acpi_osc_context osc_context = {
 557                 .uuid_str = sb_uuid_str,
 558                 .rev = 1,
 559                 .cap.length = 8,
 560                 .cap.pointer = capbuf,
 561         };
 562         acpi_status status;
 563
 564         if (!processor_physically_present(handle))
 565                 return AE_OK;
 566
 567         arch_acpi_set_proc_cap_bits(&capbuf[OSC_SUPPORT_DWORD]);
 568
 569         status = acpi_run_osc(handle, &osc_context);
 570         if (ACPI_FAILURE(status))
 571                 return status;
 572
 573         kfree(osc_context.ret.pointer);
 574
 575         return AE_OK;
 576 }
 577
 578 static bool __init acpi_early_processor_osc(void)
 579 {
 580         acpi_status status;
 581
 582         acpi_proc_quirk_mwait_check();
 583
 584         status = acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
 585                                      ACPI_UINT32_MAX, acpi_processor_osc, NULL,
 586                                      NULL, NULL);
 587         if (ACPI_FAILURE(status))
 588                 return false;
 589
 590         status = acpi_get_devices(ACPI_PROCESSOR_DEVICE_HID, acpi_processor_osc,
 591                                   NULL, NULL);
 592         if (ACPI_FAILURE(status))
 593                 return false;
 594
 595         return true;
 596 }
 597
 598 void __init acpi_early_processor_control_setup(void)
 599 {
 600         if (acpi_early_processor_osc()) {
 601                 pr_info("_OSC evaluated successfully for all CPUs\n");
 602         } else {
 603                 pr_info("_OSC evaluation for CPUs failed, trying _PDC\n");
 604                 acpi_early_processor_set_pdc();
 605         }
 606 }
 607 #endif
 608
 609 /*
 610  * The following ACPI IDs are known to be suitable for representing as
 611  * processor devices.
 612  */
 613 static const struct acpi_device_id processor_device_ids[] = {
 614
 615         { ACPI_PROCESSOR_OBJECT_HID, },
 616         { ACPI_PROCESSOR_DEVICE_HID, },
 617
 618         { }
 619 };
 620
 621 static struct acpi_scan_handler processor_handler = {
 622         .ids = processor_device_ids,
 623         .attach = acpi_processor_add,
 624 #ifdef CONFIG_ACPI_HOTPLUG_CPU
 625         .detach = acpi_processor_remove,
 626 #endif
 627         .hotplug = {
 628                 .enabled = true,
 629         },
 630 };
 631
 632 static int acpi_processor_container_attach(struct acpi_device *dev,
 633                                            const struct acpi_device_id *id)
 634 {
 635         return 1;
 636 }
 637
 638 static const struct acpi_device_id processor_container_ids[] = {
 639         { ACPI_PROCESSOR_CONTAINER_HID, },
 640         { }
 641 };
 642
 643 static struct acpi_scan_handler processor_container_handler = {
 644         .ids = processor_container_ids,
 645         .attach = acpi_processor_container_attach,
 646 };
 647
 648 /* The number of the unique processor IDs */
 649 static int nr_unique_ids __initdata;
 650
 651 /* The number of the duplicate processor IDs */
 652 static int nr_duplicate_ids;
 653
 654 /* Used to store the unique processor IDs */
 655 static int unique_processor_ids[] __initdata = {
 656         [0 ... NR_CPUS - 1] = -1,
 657 };
 658
 659 /* Used to store the duplicate processor IDs */
 660 static int duplicate_processor_ids[] = {
 661         [0 ... NR_CPUS - 1] = -1,
 662 };
 663
 664 static void __init processor_validated_ids_update(int proc_id)
 665 {
 666         int i;
 667
 668         if (nr_unique_ids == NR_CPUS||nr_duplicate_ids == NR_CPUS)
 669                 return;
 670
 671         /*
 672          * Firstly, compare the proc_id with duplicate IDs, if the proc_id is
 673          * already in the IDs, do nothing.
 674          */
 675         for (i = 0; i < nr_duplicate_ids; i++) {
 676                 if (duplicate_processor_ids[i] == proc_id)
 677                         return;
 678         }
 679
 680         /*
 681          * Secondly, compare the proc_id with unique IDs, if the proc_id is in
 682          * the IDs, put it in the duplicate IDs.
 683          */
 684         for (i = 0; i < nr_unique_ids; i++) {
 685                 if (unique_processor_ids[i] == proc_id) {
 686                         duplicate_processor_ids[nr_duplicate_ids] = proc_id;
 687                         nr_duplicate_ids++;
 688                         return;
 689                 }
 690         }
 691
 692         /*
 693          * Lastly, the proc_id is a unique ID, put it in the unique IDs.
 694          */
 695         unique_processor_ids[nr_unique_ids] = proc_id;
 696         nr_unique_ids++;
 697 }
 698
 699 static acpi_status __init acpi_processor_ids_walk(acpi_handle handle,
 700                                                   u32 lvl,
 701                                                   void *context,
 702                                                   void **rv)
 703 {
 704         acpi_status status;
 705         acpi_object_type acpi_type;
 706         unsigned long long uid;
 707         union acpi_object object = { 0 };
 708         struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
 709
 710         status = acpi_get_type(handle, &acpi_type);
 711         if (ACPI_FAILURE(status))
 712                 return status;
 713
 714         switch (acpi_type) {
 715         case ACPI_TYPE_PROCESSOR:
 716                 status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
 717                 if (ACPI_FAILURE(status))
 718                         goto err;
 719                 uid = object.processor.proc_id;
 720                 break;
 721
 722         case ACPI_TYPE_DEVICE:
 723                 status = acpi_evaluate_integer(handle, "_UID", NULL, &uid);
 724                 if (ACPI_FAILURE(status))
 725                         goto err;
 726                 break;
 727         default:
 728                 goto err;
 729         }
 730
 731         processor_validated_ids_update(uid);
 732         return AE_OK;
 733
 734 err:
 735         /* Exit on error, but don't abort the namespace walk */
 736         acpi_handle_info(handle, "Invalid processor object\n");
 737         return AE_OK;
 738
 739 }
 740
 741 static void __init acpi_processor_check_duplicates(void)
 742 {
 743         /* check the correctness for all processors in ACPI namespace */
 744         acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
 745                                                 ACPI_UINT32_MAX,
 746                                                 acpi_processor_ids_walk,
 747                                                 NULL, NULL, NULL);
 748         acpi_get_devices(ACPI_PROCESSOR_DEVICE_HID, acpi_processor_ids_walk,
 749                                                 NULL, NULL);
 750 }
 751
 752 bool acpi_duplicate_processor_id(int proc_id)
 753 {
 754         int i;
 755
 756         /*
 757          * compare the proc_id with duplicate IDs, if the proc_id is already
 758          * in the duplicate IDs, return true, otherwise, return false.
 759          */
 760         for (i = 0; i < nr_duplicate_ids; i++) {
 761                 if (duplicate_processor_ids[i] == proc_id)
 762                         return true;
 763         }
 764         return false;
 765 }
 766
 767 void __init acpi_processor_init(void)
 768 {
 769         acpi_processor_check_duplicates();
 770         acpi_scan_add_handler_with_hotplug(&processor_handler, "processor");
 771         acpi_scan_add_handler(&processor_container_handler);
 772         acpi_pcc_cpufreq_init();
 773 }
 774
 775 #ifdef CONFIG_ACPI_PROCESSOR_CSTATE
 776 /**
 777  * acpi_processor_claim_cst_control - Request _CST control from the platform.
 778  */
 779 bool acpi_processor_claim_cst_control(void)
 780 {
 781         static bool cst_control_claimed;
 782         acpi_status status;
 783
 784         if (!acpi_gbl_FADT.cst_control || cst_control_claimed)
 785                 return true;
 786
 787         status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
 788                                     acpi_gbl_FADT.cst_control, 8);
 789         if (ACPI_FAILURE(status)) {
 790                 pr_warn("ACPI: Failed to claim processor _CST control\n");
 791                 return false;
 792         }
 793
 794         cst_control_claimed = true;
 795         return true;
 796 }
 797 EXPORT_SYMBOL_GPL(acpi_processor_claim_cst_control);
 798
 799 /**
 800  * acpi_processor_evaluate_cst - Evaluate the processor _CST control method.
 801  * @handle: ACPI handle of the processor object containing the _CST.
 802  * @cpu: The numeric ID of the target CPU.
 803  * @info: Object write the C-states information into.
 804  *
 805  * Extract the C-state information for the given CPU from the output of the _CST
 806  * control method under the corresponding ACPI processor object (or processor
 807  * device object) and populate @info with it.
 808  *
 809  * If any ACPI_ADR_SPACE_FIXED_HARDWARE C-states are found, invoke
 810  * acpi_processor_ffh_cstate_probe() to verify them and update the
 811  * cpu_cstate_entry data for @cpu.
 812  */
 813 int acpi_processor_evaluate_cst(acpi_handle handle, u32 cpu,
 814                                 struct acpi_processor_power *info)
 815 {
 816         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 817         union acpi_object *cst;
 818         acpi_status status;
 819         u64 count;
 820         int last_index = 0;
 821         int i, ret = 0;
 822
 823         status = acpi_evaluate_object(handle, "_CST", NULL, &buffer);
 824         if (ACPI_FAILURE(status)) {
 825                 acpi_handle_debug(handle, "No _CST\n");
 826                 return -ENODEV;
 827         }
 828
 829         cst = buffer.pointer;
 830
 831         /* There must be at least 2 elements. */
 832         if (!cst || cst->type != ACPI_TYPE_PACKAGE || cst->package.count < 2) {
 833                 acpi_handle_warn(handle, "Invalid _CST output\n");
 834                 ret = -EFAULT;
 835                 goto end;
 836         }
 837
 838         count = cst->package.elements[0].integer.value;
 839
 840         /* Validate the number of C-states. */
 841         if (count < 1 || count != cst->package.count - 1) {
 842                 acpi_handle_warn(handle, "Inconsistent _CST data\n");
 843                 ret = -EFAULT;
 844                 goto end;
 845         }
 846
 847         for (i = 1; i <= count; i++) {
 848                 union acpi_object *element;
 849                 union acpi_object *obj;
 850                 struct acpi_power_register *reg;
 851                 struct acpi_processor_cx cx;
 852
 853                 /*
 854                  * If there is not enough space for all C-states, skip the
 855                  * excess ones and log a warning.
 856                  */
 857                 if (last_index >= ACPI_PROCESSOR_MAX_POWER - 1) {
 858                         acpi_handle_warn(handle,
 859                                          "No room for more idle states (limit: %d)\n",
 860                                          ACPI_PROCESSOR_MAX_POWER - 1);
 861                         break;
 862                 }
 863
 864                 memset(&cx, 0, sizeof(cx));
 865
 866                 element = &cst->package.elements[i];
 867                 if (element->type != ACPI_TYPE_PACKAGE) {
 868                         acpi_handle_info(handle, "_CST C%d type(%x) is not package, skip...\n",
 869                                          i, element->type);
 870                         continue;
 871                 }
 872
 873                 if (element->package.count != 4) {
 874                         acpi_handle_info(handle, "_CST C%d package count(%d) is not 4, skip...\n",
 875                                          i, element->package.count);
 876                         continue;
 877                 }
 878
 879                 obj = &element->package.elements[0];
 880
 881                 if (obj->type != ACPI_TYPE_BUFFER) {
 882                         acpi_handle_info(handle, "_CST C%d package element[0] type(%x) is not buffer, skip...\n",
 883                                          i, obj->type);
 884                         continue;
 885                 }
 886
 887                 reg = (struct acpi_power_register *)obj->buffer.pointer;
 888
 889                 obj = &element->package.elements[1];
 890                 if (obj->type != ACPI_TYPE_INTEGER) {
 891                         acpi_handle_info(handle, "_CST C[%d] package element[1] type(%x) is not integer, skip...\n",
 892                                          i, obj->type);
 893                         continue;
 894                 }
 895
 896                 cx.type = obj->integer.value;
 897                 /*
 898                  * There are known cases in which the _CST output does not
 899                  * contain C1, so if the type of the first state found is not
 900                  * C1, leave an empty slot for C1 to be filled in later.
 901                  */
 902                 if (i == 1 && cx.type != ACPI_STATE_C1)
 903                         last_index = 1;
 904
 905                 cx.address = reg->address;
 906                 cx.index = last_index + 1;
 907
 908                 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
 909                         if (!acpi_processor_ffh_cstate_probe(cpu, &cx, reg)) {
 910                                 /*
 911                                  * In the majority of cases _CST describes C1 as
 912                                  * a FIXED_HARDWARE C-state, but if the command
 913                                  * line forbids using MWAIT, use CSTATE_HALT for
 914                                  * C1 regardless.
 915                                  */
 916                                 if (cx.type == ACPI_STATE_C1 &&
 917                                     boot_option_idle_override == IDLE_NOMWAIT) {
 918                                         cx.entry_method = ACPI_CSTATE_HALT;
 919                                         snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 920                                 } else {
 921                                         cx.entry_method = ACPI_CSTATE_FFH;
 922                                 }
 923                         } else if (cx.type == ACPI_STATE_C1) {
 924                                 /*
 925                                  * In the special case of C1, FIXED_HARDWARE can
 926                                  * be handled by executing the HLT instruction.
 927                                  */
 928                                 cx.entry_method = ACPI_CSTATE_HALT;
 929                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 930                         } else {
 931                                 acpi_handle_info(handle, "_CST C%d declares FIXED_HARDWARE C-state but not supported in hardware, skip...\n",
 932                                                  i);
 933                                 continue;
 934                         }
 935                 } else if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_IO) {
 936                         cx.entry_method = ACPI_CSTATE_SYSTEMIO;
 937                         snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
 938                                  cx.address);
 939                 } else {
 940                         acpi_handle_info(handle, "_CST C%d space_id(%x) neither FIXED_HARDWARE nor SYSTEM_IO, skip...\n",
 941                                          i, reg->space_id);
 942                         continue;
 943                 }
 944
 945                 if (cx.type == ACPI_STATE_C1)
 946                         cx.valid = 1;
 947
 948                 obj = &element->package.elements[2];
 949                 if (obj->type != ACPI_TYPE_INTEGER) {
 950                         acpi_handle_info(handle, "_CST C%d package element[2] type(%x) not integer, skip...\n",
 951                                          i, obj->type);
 952                         continue;
 953                 }
 954
 955                 cx.latency = obj->integer.value;
 956
 957                 obj = &element->package.elements[3];
 958                 if (obj->type != ACPI_TYPE_INTEGER) {
 959                         acpi_handle_info(handle, "_CST C%d package element[3] type(%x) not integer, skip...\n",
 960                                          i, obj->type);
 961                         continue;
 962                 }
 963
 964                 memcpy(&info->states[++last_index], &cx, sizeof(cx));
 965         }
 966
 967         acpi_handle_info(handle, "Found %d idle states\n", last_index);
 968
 969         info->count = last_index;
 970
 971 end:
 972         kfree(buffer.pointer);
 973
 974         return ret;
 975 }
 976 EXPORT_SYMBOL_GPL(acpi_processor_evaluate_cst);
 977 #endif /* CONFIG_ACPI_PROCESSOR_CSTATE */