drivers/acpi/scan.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * scan.c - support for transforming the ACPI namespace into individual objects
   4  */
   5
   6 #define pr_fmt(fmt) "ACPI: " fmt
   7
   8 #include <linux/module.h>
   9 #include <linux/init.h>
  10 #include <linux/slab.h>
  11 #include <linux/kernel.h>
  12 #include <linux/acpi.h>
  13 #include <linux/acpi_iort.h>
  14 #include <linux/acpi_viot.h>
  15 #include <linux/iommu.h>
  16 #include <linux/signal.h>
  17 #include <linux/kthread.h>
  18 #include <linux/dmi.h>
  19 #include <linux/dma-map-ops.h>
  20 #include <linux/platform_data/x86/apple.h>
  21 #include <linux/pgtable.h>
  22 #include <linux/crc32.h>
  23 #include <linux/dma-direct.h>
  24
  25 #include "internal.h"
  26
  27 extern struct acpi_device *acpi_root;
  28
  29 #define ACPI_BUS_CLASS                  "system_bus"
  30 #define ACPI_BUS_HID                    "LNXSYBUS"
  31 #define ACPI_BUS_DEVICE_NAME            "System Bus"
  32
  33 #define INVALID_ACPI_HANDLE     ((acpi_handle)empty_zero_page)
  34
  35 static const char *dummy_hid = "device";
  36
  37 static LIST_HEAD(acpi_dep_list);
  38 static DEFINE_MUTEX(acpi_dep_list_lock);
  39 LIST_HEAD(acpi_bus_id_list);
  40 static DEFINE_MUTEX(acpi_scan_lock);
  41 static LIST_HEAD(acpi_scan_handlers_list);
  42 DEFINE_MUTEX(acpi_device_lock);
  43 LIST_HEAD(acpi_wakeup_device_list);
  44 static DEFINE_MUTEX(acpi_hp_context_lock);
  45
  46 /*
  47  * The UART device described by the SPCR table is the only object which needs
  48  * special-casing. Everything else is covered by ACPI namespace paths in STAO
  49  * table.
  50  */
  51 static u64 spcr_uart_addr;
  52
  53 void acpi_scan_lock_acquire(void)
  54 {
  55         mutex_lock(&acpi_scan_lock);
  56 }
  57 EXPORT_SYMBOL_GPL(acpi_scan_lock_acquire);
  58
  59 void acpi_scan_lock_release(void)
  60 {
  61         mutex_unlock(&acpi_scan_lock);
  62 }
  63 EXPORT_SYMBOL_GPL(acpi_scan_lock_release);
  64
  65 void acpi_lock_hp_context(void)
  66 {
  67         mutex_lock(&acpi_hp_context_lock);
  68 }
  69
  70 void acpi_unlock_hp_context(void)
  71 {
  72         mutex_unlock(&acpi_hp_context_lock);
  73 }
  74
  75 void acpi_initialize_hp_context(struct acpi_device *adev,
  76                                 struct acpi_hotplug_context *hp,
  77                                 int (*notify)(struct acpi_device *, u32),
  78                                 void (*uevent)(struct acpi_device *, u32))
  79 {
  80         acpi_lock_hp_context();
  81         hp->notify = notify;
  82         hp->uevent = uevent;
  83         acpi_set_hp_context(adev, hp);
  84         acpi_unlock_hp_context();
  85 }
  86 EXPORT_SYMBOL_GPL(acpi_initialize_hp_context);
  87
  88 int acpi_scan_add_handler(struct acpi_scan_handler *handler)
  89 {
  90         if (!handler)
  91                 return -EINVAL;
  92
  93         list_add_tail(&handler->list_node, &acpi_scan_handlers_list);
  94         return 0;
  95 }
  96
  97 int acpi_scan_add_handler_with_hotplug(struct acpi_scan_handler *handler,
  98                                        const char *hotplug_profile_name)
  99 {
 100         int error;
 101
 102         error = acpi_scan_add_handler(handler);
 103         if (error)
 104                 return error;
 105
 106         acpi_sysfs_add_hotplug_profile(&handler->hotplug, hotplug_profile_name);
 107         return 0;
 108 }
 109
 110 bool acpi_scan_is_offline(struct acpi_device *adev, bool uevent)
 111 {
 112         struct acpi_device_physical_node *pn;
 113         bool offline = true;
 114         char *envp[] = { "EVENT=offline", NULL };
 115
 116         /*
 117          * acpi_container_offline() calls this for all of the container's
 118          * children under the container's physical_node_lock lock.
 119          */
 120         mutex_lock_nested(&adev->physical_node_lock, SINGLE_DEPTH_NESTING);
 121
 122         list_for_each_entry(pn, &adev->physical_node_list, node)
 123                 if (device_supports_offline(pn->dev) && !pn->dev->offline) {
 124                         if (uevent)
 125                                 kobject_uevent_env(&pn->dev->kobj, KOBJ_CHANGE, envp);
 126
 127                         offline = false;
 128                         break;
 129                 }
 130
 131         mutex_unlock(&adev->physical_node_lock);
 132         return offline;
 133 }
 134
 135 static acpi_status acpi_bus_offline(acpi_handle handle, u32 lvl, void *data,
 136                                     void **ret_p)
 137 {
 138         struct acpi_device *device = acpi_fetch_acpi_dev(handle);
 139         struct acpi_device_physical_node *pn;
 140         bool second_pass = (bool)data;
 141         acpi_status status = AE_OK;
 142
 143         if (!device)
 144                 return AE_OK;
 145
 146         if (device->handler && !device->handler->hotplug.enabled) {
 147                 *ret_p = &device->dev;
 148                 return AE_SUPPORT;
 149         }
 150
 151         mutex_lock(&device->physical_node_lock);
 152
 153         list_for_each_entry(pn, &device->physical_node_list, node) {
 154                 int ret;
 155
 156                 if (second_pass) {
 157                         /* Skip devices offlined by the first pass. */
 158                         if (pn->put_online)
 159                                 continue;
 160                 } else {
 161                         pn->put_online = false;
 162                 }
 163                 ret = device_offline(pn->dev);
 164                 if (ret >= 0) {
 165                         pn->put_online = !ret;
 166                 } else {
 167                         *ret_p = pn->dev;
 168                         if (second_pass) {
 169                                 status = AE_ERROR;
 170                                 break;
 171                         }
 172                 }
 173         }
 174
 175         mutex_unlock(&device->physical_node_lock);
 176
 177         return status;
 178 }
 179
 180 static acpi_status acpi_bus_online(acpi_handle handle, u32 lvl, void *data,
 181                                    void **ret_p)
 182 {
 183         struct acpi_device *device = acpi_fetch_acpi_dev(handle);
 184         struct acpi_device_physical_node *pn;
 185
 186         if (!device)
 187                 return AE_OK;
 188
 189         mutex_lock(&device->physical_node_lock);
 190
 191         list_for_each_entry(pn, &device->physical_node_list, node)
 192                 if (pn->put_online) {
 193                         device_online(pn->dev);
 194                         pn->put_online = false;
 195                 }
 196
 197         mutex_unlock(&device->physical_node_lock);
 198
 199         return AE_OK;
 200 }
 201
 202 static int acpi_scan_try_to_offline(struct acpi_device *device)
 203 {
 204         acpi_handle handle = device->handle;
 205         struct device *errdev = NULL;
 206         acpi_status status;
 207
 208         /*
 209          * Carry out two passes here and ignore errors in the first pass,
 210          * because if the devices in question are memory blocks and
 211          * CONFIG_MEMCG is set, one of the blocks may hold data structures
 212          * that the other blocks depend on, but it is not known in advance which
 213          * block holds them.
 214          *
 215          * If the first pass is successful, the second one isn't needed, though.
 216          */
 217         status = acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
 218                                      NULL, acpi_bus_offline, (void *)false,
 219                                      (void **)&errdev);
 220         if (status == AE_SUPPORT) {
 221                 dev_warn(errdev, "Offline disabled.\n");
 222                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
 223                                     acpi_bus_online, NULL, NULL, NULL);
 224                 return -EPERM;
 225         }
 226         acpi_bus_offline(handle, 0, (void *)false, (void **)&errdev);
 227         if (errdev) {
 228                 errdev = NULL;
 229                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
 230                                     NULL, acpi_bus_offline, (void *)true,
 231                                     (void **)&errdev);
 232                 if (!errdev)
 233                         acpi_bus_offline(handle, 0, (void *)true,
 234                                          (void **)&errdev);
 235
 236                 if (errdev) {
 237                         dev_warn(errdev, "Offline failed.\n");
 238                         acpi_bus_online(handle, 0, NULL, NULL);
 239                         acpi_walk_namespace(ACPI_TYPE_ANY, handle,
 240                                             ACPI_UINT32_MAX, acpi_bus_online,
 241                                             NULL, NULL, NULL);
 242                         return -EBUSY;
 243                 }
 244         }
 245         return 0;
 246 }
 247
 248 static int acpi_scan_hot_remove(struct acpi_device *device)
 249 {
 250         acpi_handle handle = device->handle;
 251         unsigned long long sta;
 252         acpi_status status;
 253
 254         if (device->handler && device->handler->hotplug.demand_offline) {
 255                 if (!acpi_scan_is_offline(device, true))
 256                         return -EBUSY;
 257         } else {
 258                 int error = acpi_scan_try_to_offline(device);
 259                 if (error)
 260                         return error;
 261         }
 262
 263         acpi_handle_debug(handle, "Ejecting\n");
 264
 265         acpi_bus_trim(device);
 266
 267         acpi_evaluate_lck(handle, 0);
 268         /*
 269          * TBD: _EJD support.
 270          */
 271         status = acpi_evaluate_ej0(handle);
 272         if (status == AE_NOT_FOUND)
 273                 return -ENODEV;
 274         else if (ACPI_FAILURE(status))
 275                 return -EIO;
 276
 277         /*
 278          * Verify if eject was indeed successful.  If not, log an error
 279          * message.  No need to call _OST since _EJ0 call was made OK.
 280          */
 281         status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
 282         if (ACPI_FAILURE(status)) {
 283                 acpi_handle_warn(handle,
 284                         "Status check after eject failed (0x%x)\n", status);
 285         } else if (sta & ACPI_STA_DEVICE_ENABLED) {
 286                 acpi_handle_warn(handle,
 287                         "Eject incomplete - status 0x%llx\n", sta);
 288         }
 289
 290         return 0;
 291 }
 292
 293 static int acpi_scan_device_not_present(struct acpi_device *adev)
 294 {
 295         if (!acpi_device_enumerated(adev)) {
 296                 dev_warn(&adev->dev, "Still not present\n");
 297                 return -EALREADY;
 298         }
 299         acpi_bus_trim(adev);
 300         return 0;
 301 }
 302
 303 static int acpi_scan_device_check(struct acpi_device *adev)
 304 {
 305         int error;
 306
 307         acpi_bus_get_status(adev);
 308         if (adev->status.present || adev->status.functional) {
 309                 /*
 310                  * This function is only called for device objects for which
 311                  * matching scan handlers exist.  The only situation in which
 312                  * the scan handler is not attached to this device object yet
 313                  * is when the device has just appeared (either it wasn't
 314                  * present at all before or it was removed and then added
 315                  * again).
 316                  */
 317                 if (adev->handler) {
 318                         dev_warn(&adev->dev, "Already enumerated\n");
 319                         return -EALREADY;
 320                 }
 321                 error = acpi_bus_scan(adev->handle);
 322                 if (error) {
 323                         dev_warn(&adev->dev, "Namespace scan failure\n");
 324                         return error;
 325                 }
 326                 if (!adev->handler) {
 327                         dev_warn(&adev->dev, "Enumeration failure\n");
 328                         error = -ENODEV;
 329                 }
 330         } else {
 331                 error = acpi_scan_device_not_present(adev);
 332         }
 333         return error;
 334 }
 335
 336 static int acpi_scan_bus_check(struct acpi_device *adev, void *not_used)
 337 {
 338         struct acpi_scan_handler *handler = adev->handler;
 339         int error;
 340
 341         acpi_bus_get_status(adev);
 342         if (!(adev->status.present || adev->status.functional)) {
 343                 acpi_scan_device_not_present(adev);
 344                 return 0;
 345         }
 346         if (handler && handler->hotplug.scan_dependent)
 347                 return handler->hotplug.scan_dependent(adev);
 348
 349         error = acpi_bus_scan(adev->handle);
 350         if (error) {
 351                 dev_warn(&adev->dev, "Namespace scan failure\n");
 352                 return error;
 353         }
 354         return acpi_dev_for_each_child(adev, acpi_scan_bus_check, NULL);
 355 }
 356
 357 static int acpi_generic_hotplug_event(struct acpi_device *adev, u32 type)
 358 {
 359         switch (type) {
 360         case ACPI_NOTIFY_BUS_CHECK:
 361                 return acpi_scan_bus_check(adev, NULL);
 362         case ACPI_NOTIFY_DEVICE_CHECK:
 363                 return acpi_scan_device_check(adev);
 364         case ACPI_NOTIFY_EJECT_REQUEST:
 365         case ACPI_OST_EC_OSPM_EJECT:
 366                 if (adev->handler && !adev->handler->hotplug.enabled) {
 367                         dev_info(&adev->dev, "Eject disabled\n");
 368                         return -EPERM;
 369                 }
 370                 acpi_evaluate_ost(adev->handle, ACPI_NOTIFY_EJECT_REQUEST,
 371                                   ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
 372                 return acpi_scan_hot_remove(adev);
 373         }
 374         return -EINVAL;
 375 }
 376
 377 void acpi_device_hotplug(struct acpi_device *adev, u32 src)
 378 {
 379         u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
 380         int error = -ENODEV;
 381
 382         lock_device_hotplug();
 383         mutex_lock(&acpi_scan_lock);
 384
 385         /*
 386          * The device object's ACPI handle cannot become invalid as long as we
 387          * are holding acpi_scan_lock, but it might have become invalid before
 388          * that lock was acquired.
 389          */
 390         if (adev->handle == INVALID_ACPI_HANDLE)
 391                 goto err_out;
 392
 393         if (adev->flags.is_dock_station) {
 394                 error = dock_notify(adev, src);
 395         } else if (adev->flags.hotplug_notify) {
 396                 error = acpi_generic_hotplug_event(adev, src);
 397         } else {
 398                 int (*notify)(struct acpi_device *, u32);
 399
 400                 acpi_lock_hp_context();
 401                 notify = adev->hp ? adev->hp->notify : NULL;
 402                 acpi_unlock_hp_context();
 403                 /*
 404                  * There may be additional notify handlers for device objects
 405                  * without the .event() callback, so ignore them here.
 406                  */
 407                 if (notify)
 408                         error = notify(adev, src);
 409                 else
 410                         goto out;
 411         }
 412         switch (error) {
 413         case 0:
 414                 ost_code = ACPI_OST_SC_SUCCESS;
 415                 break;
 416         case -EPERM:
 417                 ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
 418                 break;
 419         case -EBUSY:
 420                 ost_code = ACPI_OST_SC_DEVICE_BUSY;
 421                 break;
 422         default:
 423                 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
 424                 break;
 425         }
 426
 427  err_out:
 428         acpi_evaluate_ost(adev->handle, src, ost_code, NULL);
 429
 430  out:
 431         acpi_put_acpi_dev(adev);
 432         mutex_unlock(&acpi_scan_lock);
 433         unlock_device_hotplug();
 434 }
 435
 436 static void acpi_free_power_resources_lists(struct acpi_device *device)
 437 {
 438         int i;
 439
 440         if (device->wakeup.flags.valid)
 441                 acpi_power_resources_list_free(&device->wakeup.resources);
 442
 443         if (!device->power.flags.power_resources)
 444                 return;
 445
 446         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
 447                 struct acpi_device_power_state *ps = &device->power.states[i];
 448                 acpi_power_resources_list_free(&ps->resources);
 449         }
 450 }
 451
 452 static void acpi_device_release(struct device *dev)
 453 {
 454         struct acpi_device *acpi_dev = to_acpi_device(dev);
 455
 456         acpi_free_properties(acpi_dev);
 457         acpi_free_pnp_ids(&acpi_dev->pnp);
 458         acpi_free_power_resources_lists(acpi_dev);
 459         kfree(acpi_dev);
 460 }
 461
 462 static void acpi_device_del(struct acpi_device *device)
 463 {
 464         struct acpi_device_bus_id *acpi_device_bus_id;
 465
 466         mutex_lock(&acpi_device_lock);
 467
 468         list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node)
 469                 if (!strcmp(acpi_device_bus_id->bus_id,
 470                             acpi_device_hid(device))) {
 471                         ida_free(&acpi_device_bus_id->instance_ida,
 472                                  device->pnp.instance_no);
 473                         if (ida_is_empty(&acpi_device_bus_id->instance_ida)) {
 474                                 list_del(&acpi_device_bus_id->node);
 475                                 kfree_const(acpi_device_bus_id->bus_id);
 476                                 kfree(acpi_device_bus_id);
 477                         }
 478                         break;
 479                 }
 480
 481         list_del(&device->wakeup_list);
 482
 483         mutex_unlock(&acpi_device_lock);
 484
 485         acpi_power_add_remove_device(device, false);
 486         acpi_device_remove_files(device);
 487         if (device->remove)
 488                 device->remove(device);
 489
 490         device_del(&device->dev);
 491 }
 492
 493 static BLOCKING_NOTIFIER_HEAD(acpi_reconfig_chain);
 494
 495 static LIST_HEAD(acpi_device_del_list);
 496 static DEFINE_MUTEX(acpi_device_del_lock);
 497
 498 static void acpi_device_del_work_fn(struct work_struct *work_not_used)
 499 {
 500         for (;;) {
 501                 struct acpi_device *adev;
 502
 503                 mutex_lock(&acpi_device_del_lock);
 504
 505                 if (list_empty(&acpi_device_del_list)) {
 506                         mutex_unlock(&acpi_device_del_lock);
 507                         break;
 508                 }
 509                 adev = list_first_entry(&acpi_device_del_list,
 510                                         struct acpi_device, del_list);
 511                 list_del(&adev->del_list);
 512
 513                 mutex_unlock(&acpi_device_del_lock);
 514
 515                 blocking_notifier_call_chain(&acpi_reconfig_chain,
 516                                              ACPI_RECONFIG_DEVICE_REMOVE, adev);
 517
 518                 acpi_device_del(adev);
 519                 /*
 520                  * Drop references to all power resources that might have been
 521                  * used by the device.
 522                  */
 523                 acpi_power_transition(adev, ACPI_STATE_D3_COLD);
 524                 acpi_dev_put(adev);
 525         }
 526 }
 527
 528 /**
 529  * acpi_scan_drop_device - Drop an ACPI device object.
 530  * @handle: Handle of an ACPI namespace node, not used.
 531  * @context: Address of the ACPI device object to drop.
 532  *
 533  * This is invoked by acpi_ns_delete_node() during the removal of the ACPI
 534  * namespace node the device object pointed to by @context is attached to.
 535  *
 536  * The unregistration is carried out asynchronously to avoid running
 537  * acpi_device_del() under the ACPICA's namespace mutex and the list is used to
 538  * ensure the correct ordering (the device objects must be unregistered in the
 539  * same order in which the corresponding namespace nodes are deleted).
 540  */
 541 static void acpi_scan_drop_device(acpi_handle handle, void *context)
 542 {
 543         static DECLARE_WORK(work, acpi_device_del_work_fn);
 544         struct acpi_device *adev = context;
 545
 546         mutex_lock(&acpi_device_del_lock);
 547
 548         /*
 549          * Use the ACPI hotplug workqueue which is ordered, so this work item
 550          * won't run after any hotplug work items submitted subsequently.  That
 551          * prevents attempts to register device objects identical to those being
 552          * deleted from happening concurrently (such attempts result from
 553          * hotplug events handled via the ACPI hotplug workqueue).  It also will
 554          * run after all of the work items submitted previously, which helps
 555          * those work items to ensure that they are not accessing stale device
 556          * objects.
 557          */
 558         if (list_empty(&acpi_device_del_list))
 559                 acpi_queue_hotplug_work(&work);
 560
 561         list_add_tail(&adev->del_list, &acpi_device_del_list);
 562         /* Make acpi_ns_validate_handle() return NULL for this handle. */
 563         adev->handle = INVALID_ACPI_HANDLE;
 564
 565         mutex_unlock(&acpi_device_del_lock);
 566 }
 567
 568 static struct acpi_device *handle_to_device(acpi_handle handle,
 569                                             void (*callback)(void *))
 570 {
 571         struct acpi_device *adev = NULL;
 572         acpi_status status;
 573
 574         status = acpi_get_data_full(handle, acpi_scan_drop_device,
 575                                     (void **)&adev, callback);
 576         if (ACPI_FAILURE(status) || !adev) {
 577                 acpi_handle_debug(handle, "No context!\n");
 578                 return NULL;
 579         }
 580         return adev;
 581 }
 582
 583 /**
 584  * acpi_fetch_acpi_dev - Retrieve ACPI device object.
 585  * @handle: ACPI handle associated with the requested ACPI device object.
 586  *
 587  * Return a pointer to the ACPI device object associated with @handle, if
 588  * present, or NULL otherwise.
 589  */
 590 struct acpi_device *acpi_fetch_acpi_dev(acpi_handle handle)
 591 {
 592         return handle_to_device(handle, NULL);
 593 }
 594 EXPORT_SYMBOL_GPL(acpi_fetch_acpi_dev);
 595
 596 static void get_acpi_device(void *dev)
 597 {
 598         acpi_dev_get(dev);
 599 }
 600
 601 /**
 602  * acpi_get_acpi_dev - Retrieve ACPI device object and reference count it.
 603  * @handle: ACPI handle associated with the requested ACPI device object.
 604  *
 605  * Return a pointer to the ACPI device object associated with @handle and bump
 606  * up that object's reference counter (under the ACPI Namespace lock), if
 607  * present, or return NULL otherwise.
 608  *
 609  * The ACPI device object reference acquired by this function needs to be
 610  * dropped via acpi_dev_put().
 611  */
 612 struct acpi_device *acpi_get_acpi_dev(acpi_handle handle)
 613 {
 614         return handle_to_device(handle, get_acpi_device);
 615 }
 616 EXPORT_SYMBOL_GPL(acpi_get_acpi_dev);
 617
 618 static struct acpi_device_bus_id *acpi_device_bus_id_match(const char *dev_id)
 619 {
 620         struct acpi_device_bus_id *acpi_device_bus_id;
 621
 622         /* Find suitable bus_id and instance number in acpi_bus_id_list. */
 623         list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
 624                 if (!strcmp(acpi_device_bus_id->bus_id, dev_id))
 625                         return acpi_device_bus_id;
 626         }
 627         return NULL;
 628 }
 629
 630 static int acpi_device_set_name(struct acpi_device *device,
 631                                 struct acpi_device_bus_id *acpi_device_bus_id)
 632 {
 633         struct ida *instance_ida = &acpi_device_bus_id->instance_ida;
 634         int result;
 635
 636         result = ida_alloc(instance_ida, GFP_KERNEL);
 637         if (result < 0)
 638                 return result;
 639
 640         device->pnp.instance_no = result;
 641         dev_set_name(&device->dev, "%s:%02x", acpi_device_bus_id->bus_id, result);
 642         return 0;
 643 }
 644
 645 int acpi_tie_acpi_dev(struct acpi_device *adev)
 646 {
 647         acpi_handle handle = adev->handle;
 648         acpi_status status;
 649
 650         if (!handle)
 651                 return 0;
 652
 653         status = acpi_attach_data(handle, acpi_scan_drop_device, adev);
 654         if (ACPI_FAILURE(status)) {
 655                 acpi_handle_err(handle, "Unable to attach device data\n");
 656                 return -ENODEV;
 657         }
 658
 659         return 0;
 660 }
 661
 662 static void acpi_store_pld_crc(struct acpi_device *adev)
 663 {
 664         struct acpi_pld_info *pld;
 665         acpi_status status;
 666
 667         status = acpi_get_physical_device_location(adev->handle, &pld);
 668         if (ACPI_FAILURE(status))
 669                 return;
 670
 671         adev->pld_crc = crc32(~0, pld, sizeof(*pld));
 672         ACPI_FREE(pld);
 673 }
 674
 675 int acpi_device_add(struct acpi_device *device)
 676 {
 677         struct acpi_device_bus_id *acpi_device_bus_id;
 678         int result;
 679
 680         /*
 681          * Linkage
 682          * -------
 683          * Link this device to its parent and siblings.
 684          */
 685         INIT_LIST_HEAD(&device->wakeup_list);
 686         INIT_LIST_HEAD(&device->physical_node_list);
 687         INIT_LIST_HEAD(&device->del_list);
 688         mutex_init(&device->physical_node_lock);
 689
 690         mutex_lock(&acpi_device_lock);
 691
 692         acpi_device_bus_id = acpi_device_bus_id_match(acpi_device_hid(device));
 693         if (acpi_device_bus_id) {
 694                 result = acpi_device_set_name(device, acpi_device_bus_id);
 695                 if (result)
 696                         goto err_unlock;
 697         } else {
 698                 acpi_device_bus_id = kzalloc(sizeof(*acpi_device_bus_id),
 699                                              GFP_KERNEL);
 700                 if (!acpi_device_bus_id) {
 701                         result = -ENOMEM;
 702                         goto err_unlock;
 703                 }
 704                 acpi_device_bus_id->bus_id =
 705                         kstrdup_const(acpi_device_hid(device), GFP_KERNEL);
 706                 if (!acpi_device_bus_id->bus_id) {
 707                         kfree(acpi_device_bus_id);
 708                         result = -ENOMEM;
 709                         goto err_unlock;
 710                 }
 711
 712                 ida_init(&acpi_device_bus_id->instance_ida);
 713
 714                 result = acpi_device_set_name(device, acpi_device_bus_id);
 715                 if (result) {
 716                         kfree_const(acpi_device_bus_id->bus_id);
 717                         kfree(acpi_device_bus_id);
 718                         goto err_unlock;
 719                 }
 720
 721                 list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
 722         }
 723
 724         if (device->wakeup.flags.valid)
 725                 list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);
 726
 727         acpi_store_pld_crc(device);
 728
 729         mutex_unlock(&acpi_device_lock);
 730
 731         result = device_add(&device->dev);
 732         if (result) {
 733                 dev_err(&device->dev, "Error registering device\n");
 734                 goto err;
 735         }
 736
 737         result = acpi_device_setup_files(device);
 738         if (result)
 739                 pr_err("Error creating sysfs interface for device %s\n",
 740                        dev_name(&device->dev));
 741
 742         return 0;
 743
 744 err:
 745         mutex_lock(&acpi_device_lock);
 746
 747         list_del(&device->wakeup_list);
 748
 749 err_unlock:
 750         mutex_unlock(&acpi_device_lock);
 751
 752         acpi_detach_data(device->handle, acpi_scan_drop_device);
 753
 754         return result;
 755 }
 756
 757 /* --------------------------------------------------------------------------
 758                                  Device Enumeration
 759    -------------------------------------------------------------------------- */
 760 static bool acpi_info_matches_ids(struct acpi_device_info *info,
 761                                   const char * const ids[])
 762 {
 763         struct acpi_pnp_device_id_list *cid_list = NULL;
 764         int i, index;
 765
 766         if (!(info->valid & ACPI_VALID_HID))
 767                 return false;
 768
 769         index = match_string(ids, -1, info->hardware_id.string);
 770         if (index >= 0)
 771                 return true;
 772
 773         if (info->valid & ACPI_VALID_CID)
 774                 cid_list = &info->compatible_id_list;
 775
 776         if (!cid_list)
 777                 return false;
 778
 779         for (i = 0; i < cid_list->count; i++) {
 780                 index = match_string(ids, -1, cid_list->ids[i].string);
 781                 if (index >= 0)
 782                         return true;
 783         }
 784
 785         return false;
 786 }
 787
 788 /* List of HIDs for which we ignore matching ACPI devices, when checking _DEP lists. */
 789 static const char * const acpi_ignore_dep_ids[] = {
 790         "PNP0D80", /* Windows-compatible System Power Management Controller */
 791         "INT33BD", /* Intel Baytrail Mailbox Device */
 792         NULL
 793 };
 794
 795 /* List of HIDs for which we honor deps of matching ACPI devs, when checking _DEP lists. */
 796 static const char * const acpi_honor_dep_ids[] = {
 797         "INT3472", /* Camera sensor PMIC / clk and regulator info */
 798         NULL
 799 };
 800
 801 static struct acpi_device *acpi_find_parent_acpi_dev(acpi_handle handle)
 802 {
 803         struct acpi_device *adev;
 804
 805         /*
 806          * Fixed hardware devices do not appear in the namespace and do not
 807          * have handles, but we fabricate acpi_devices for them, so we have
 808          * to deal with them specially.
 809          */
 810         if (!handle)
 811                 return acpi_root;
 812
 813         do {
 814                 acpi_status status;
 815
 816                 status = acpi_get_parent(handle, &handle);
 817                 if (ACPI_FAILURE(status)) {
 818                         if (status != AE_NULL_ENTRY)
 819                                 return acpi_root;
 820
 821                         return NULL;
 822                 }
 823                 adev = acpi_fetch_acpi_dev(handle);
 824         } while (!adev);
 825         return adev;
 826 }
 827
 828 acpi_status
 829 acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
 830 {
 831         acpi_status status;
 832         acpi_handle tmp;
 833         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
 834         union acpi_object *obj;
 835
 836         status = acpi_get_handle(handle, "_EJD", &tmp);
 837         if (ACPI_FAILURE(status))
 838                 return status;
 839
 840         status = acpi_evaluate_object(handle, "_EJD", NULL, &buffer);
 841         if (ACPI_SUCCESS(status)) {
 842                 obj = buffer.pointer;
 843                 status = acpi_get_handle(ACPI_ROOT_OBJECT, obj->string.pointer,
 844                                          ejd);
 845                 kfree(buffer.pointer);
 846         }
 847         return status;
 848 }
 849 EXPORT_SYMBOL_GPL(acpi_bus_get_ejd);
 850
 851 static int acpi_bus_extract_wakeup_device_power_package(struct acpi_device *dev)
 852 {
 853         acpi_handle handle = dev->handle;
 854         struct acpi_device_wakeup *wakeup = &dev->wakeup;
 855         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 856         union acpi_object *package = NULL;
 857         union acpi_object *element = NULL;
 858         acpi_status status;
 859         int err = -ENODATA;
 860
 861         INIT_LIST_HEAD(&wakeup->resources);
 862
 863         /* _PRW */
 864         status = acpi_evaluate_object(handle, "_PRW", NULL, &buffer);
 865         if (ACPI_FAILURE(status)) {
 866                 acpi_handle_info(handle, "_PRW evaluation failed: %s\n",
 867                                  acpi_format_exception(status));
 868                 return err;
 869         }
 870
 871         package = (union acpi_object *)buffer.pointer;
 872
 873         if (!package || package->package.count < 2)
 874                 goto out;
 875
 876         element = &(package->package.elements[0]);
 877         if (!element)
 878                 goto out;
 879
 880         if (element->type == ACPI_TYPE_PACKAGE) {
 881                 if ((element->package.count < 2) ||
 882                     (element->package.elements[0].type !=
 883                      ACPI_TYPE_LOCAL_REFERENCE)
 884                     || (element->package.elements[1].type != ACPI_TYPE_INTEGER))
 885                         goto out;
 886
 887                 wakeup->gpe_device =
 888                     element->package.elements[0].reference.handle;
 889                 wakeup->gpe_number =
 890                     (u32) element->package.elements[1].integer.value;
 891         } else if (element->type == ACPI_TYPE_INTEGER) {
 892                 wakeup->gpe_device = NULL;
 893                 wakeup->gpe_number = element->integer.value;
 894         } else {
 895                 goto out;
 896         }
 897
 898         element = &(package->package.elements[1]);
 899         if (element->type != ACPI_TYPE_INTEGER)
 900                 goto out;
 901
 902         wakeup->sleep_state = element->integer.value;
 903
 904         err = acpi_extract_power_resources(package, 2, &wakeup->resources);
 905         if (err)
 906                 goto out;
 907
 908         if (!list_empty(&wakeup->resources)) {
 909                 int sleep_state;
 910
 911                 err = acpi_power_wakeup_list_init(&wakeup->resources,
 912                                                   &sleep_state);
 913                 if (err) {
 914                         acpi_handle_warn(handle, "Retrieving current states "
 915                                          "of wakeup power resources failed\n");
 916                         acpi_power_resources_list_free(&wakeup->resources);
 917                         goto out;
 918                 }
 919                 if (sleep_state < wakeup->sleep_state) {
 920                         acpi_handle_warn(handle, "Overriding _PRW sleep state "
 921                                          "(S%d) by S%d from power resources\n",
 922                                          (int)wakeup->sleep_state, sleep_state);
 923                         wakeup->sleep_state = sleep_state;
 924                 }
 925         }
 926
 927  out:
 928         kfree(buffer.pointer);
 929         return err;
 930 }
 931
 932 static bool acpi_wakeup_gpe_init(struct acpi_device *device)
 933 {
 934         static const struct acpi_device_id button_device_ids[] = {
 935                 {"PNP0C0C", 0},         /* Power button */
 936                 {"PNP0C0D", 0},         /* Lid */
 937                 {"PNP0C0E", 0},         /* Sleep button */
 938                 {"", 0},
 939         };
 940         struct acpi_device_wakeup *wakeup = &device->wakeup;
 941         acpi_status status;
 942
 943         wakeup->flags.notifier_present = 0;
 944
 945         /* Power button, Lid switch always enable wakeup */
 946         if (!acpi_match_device_ids(device, button_device_ids)) {
 947                 if (!acpi_match_device_ids(device, &button_device_ids[1])) {
 948                         /* Do not use Lid/sleep button for S5 wakeup */
 949                         if (wakeup->sleep_state == ACPI_STATE_S5)
 950                                 wakeup->sleep_state = ACPI_STATE_S4;
 951                 }
 952                 acpi_mark_gpe_for_wake(wakeup->gpe_device, wakeup->gpe_number);
 953                 device_set_wakeup_capable(&device->dev, true);
 954                 return true;
 955         }
 956
 957         status = acpi_setup_gpe_for_wake(device->handle, wakeup->gpe_device,
 958                                          wakeup->gpe_number);
 959         return ACPI_SUCCESS(status);
 960 }
 961
 962 static void acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
 963 {
 964         int err;
 965
 966         /* Presence of _PRW indicates wake capable */
 967         if (!acpi_has_method(device->handle, "_PRW"))
 968                 return;
 969
 970         err = acpi_bus_extract_wakeup_device_power_package(device);
 971         if (err) {
 972                 dev_err(&device->dev, "Unable to extract wakeup power resources");
 973                 return;
 974         }
 975
 976         device->wakeup.flags.valid = acpi_wakeup_gpe_init(device);
 977         device->wakeup.prepare_count = 0;
 978         /*
 979          * Call _PSW/_DSW object to disable its ability to wake the sleeping
 980          * system for the ACPI device with the _PRW object.
 981          * The _PSW object is deprecated in ACPI 3.0 and is replaced by _DSW.
 982          * So it is necessary to call _DSW object first. Only when it is not
 983          * present will the _PSW object used.
 984          */
 985         err = acpi_device_sleep_wake(device, 0, 0, 0);
 986         if (err)
 987                 pr_debug("error in _DSW or _PSW evaluation\n");
 988 }
 989
 990 static void acpi_bus_init_power_state(struct acpi_device *device, int state)
 991 {
 992         struct acpi_device_power_state *ps = &device->power.states[state];
 993         char pathname[5] = { '_', 'P', 'R', '0' + state, '\0' };
 994         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 995         acpi_status status;
 996
 997         INIT_LIST_HEAD(&ps->resources);
 998
 999         /* Evaluate "_PRx" to get referenced power resources */
1000         status = acpi_evaluate_object(device->handle, pathname, NULL, &buffer);
1001         if (ACPI_SUCCESS(status)) {
1002                 union acpi_object *package = buffer.pointer;
1003
1004                 if (buffer.length && package
1005                     && package->type == ACPI_TYPE_PACKAGE
1006                     && package->package.count)
1007                         acpi_extract_power_resources(package, 0, &ps->resources);
1008
1009                 ACPI_FREE(buffer.pointer);
1010         }
1011
1012         /* Evaluate "_PSx" to see if we can do explicit sets */
1013         pathname[2] = 'S';
1014         if (acpi_has_method(device->handle, pathname))
1015                 ps->flags.explicit_set = 1;
1016
1017         /* State is valid if there are means to put the device into it. */
1018         if (!list_empty(&ps->resources) || ps->flags.explicit_set)
1019                 ps->flags.valid = 1;
1020
1021         ps->power = -1;         /* Unknown - driver assigned */
1022         ps->latency = -1;       /* Unknown - driver assigned */
1023 }
1024
1025 static void acpi_bus_get_power_flags(struct acpi_device *device)
1026 {
1027         unsigned long long dsc = ACPI_STATE_D0;
1028         u32 i;
1029
1030         /* Presence of _PS0|_PR0 indicates 'power manageable' */
1031         if (!acpi_has_method(device->handle, "_PS0") &&
1032             !acpi_has_method(device->handle, "_PR0"))
1033                 return;
1034
1035         device->flags.power_manageable = 1;
1036
1037         /*
1038          * Power Management Flags
1039          */
1040         if (acpi_has_method(device->handle, "_PSC"))
1041                 device->power.flags.explicit_get = 1;
1042
1043         if (acpi_has_method(device->handle, "_IRC"))
1044                 device->power.flags.inrush_current = 1;
1045
1046         if (acpi_has_method(device->handle, "_DSW"))
1047                 device->power.flags.dsw_present = 1;
1048
1049         acpi_evaluate_integer(device->handle, "_DSC", NULL, &dsc);
1050         device->power.state_for_enumeration = dsc;
1051
1052         /*
1053          * Enumerate supported power management states
1054          */
1055         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++)
1056                 acpi_bus_init_power_state(device, i);
1057
1058         INIT_LIST_HEAD(&device->power.states[ACPI_STATE_D3_COLD].resources);
1059
1060         /* Set the defaults for D0 and D3hot (always supported). */
1061         device->power.states[ACPI_STATE_D0].flags.valid = 1;
1062         device->power.states[ACPI_STATE_D0].power = 100;
1063         device->power.states[ACPI_STATE_D3_HOT].flags.valid = 1;
1064
1065         /*
1066          * Use power resources only if the D0 list of them is populated, because
1067          * some platforms may provide _PR3 only to indicate D3cold support and
1068          * in those cases the power resources list returned by it may be bogus.
1069          */
1070         if (!list_empty(&device->power.states[ACPI_STATE_D0].resources)) {
1071                 device->power.flags.power_resources = 1;
1072                 /*
1073                  * D3cold is supported if the D3hot list of power resources is
1074                  * not empty.
1075                  */
1076                 if (!list_empty(&device->power.states[ACPI_STATE_D3_HOT].resources))
1077                         device->power.states[ACPI_STATE_D3_COLD].flags.valid = 1;
1078         }
1079
1080         if (acpi_bus_init_power(device))
1081                 device->flags.power_manageable = 0;
1082 }
1083
1084 static void acpi_bus_get_flags(struct acpi_device *device)
1085 {
1086         /* Presence of _STA indicates 'dynamic_status' */
1087         if (acpi_has_method(device->handle, "_STA"))
1088                 device->flags.dynamic_status = 1;
1089
1090         /* Presence of _RMV indicates 'removable' */
1091         if (acpi_has_method(device->handle, "_RMV"))
1092                 device->flags.removable = 1;
1093
1094         /* Presence of _EJD|_EJ0 indicates 'ejectable' */
1095         if (acpi_has_method(device->handle, "_EJD") ||
1096             acpi_has_method(device->handle, "_EJ0"))
1097                 device->flags.ejectable = 1;
1098 }
1099
1100 static void acpi_device_get_busid(struct acpi_device *device)
1101 {
1102         char bus_id[5] = { '?', 0 };
1103         struct acpi_buffer buffer = { sizeof(bus_id), bus_id };
1104         int i = 0;
1105
1106         /*
1107          * Bus ID
1108          * ------
1109          * The device's Bus ID is simply the object name.
1110          * TBD: Shouldn't this value be unique (within the ACPI namespace)?
1111          */
1112         if (!acpi_dev_parent(device)) {
1113                 strcpy(device->pnp.bus_id, "ACPI");
1114                 return;
1115         }
1116
1117         switch (device->device_type) {
1118         case ACPI_BUS_TYPE_POWER_BUTTON:
1119                 strcpy(device->pnp.bus_id, "PWRF");
1120                 break;
1121         case ACPI_BUS_TYPE_SLEEP_BUTTON:
1122                 strcpy(device->pnp.bus_id, "SLPF");
1123                 break;
1124         case ACPI_BUS_TYPE_ECDT_EC:
1125                 strcpy(device->pnp.bus_id, "ECDT");
1126                 break;
1127         default:
1128                 acpi_get_name(device->handle, ACPI_SINGLE_NAME, &buffer);
1129                 /* Clean up trailing underscores (if any) */
1130                 for (i = 3; i > 1; i--) {
1131                         if (bus_id[i] == '_')
1132                                 bus_id[i] = '\0';
1133                         else
1134                                 break;
1135                 }
1136                 strcpy(device->pnp.bus_id, bus_id);
1137                 break;
1138         }
1139 }
1140
1141 /*
1142  * acpi_ata_match - see if an acpi object is an ATA device
1143  *
1144  * If an acpi object has one of the ACPI ATA methods defined,
1145  * then we can safely call it an ATA device.
1146  */
1147 bool acpi_ata_match(acpi_handle handle)
1148 {
1149         return acpi_has_method(handle, "_GTF") ||
1150                acpi_has_method(handle, "_GTM") ||
1151                acpi_has_method(handle, "_STM") ||
1152                acpi_has_method(handle, "_SDD");
1153 }
1154
1155 /*
1156  * acpi_bay_match - see if an acpi object is an ejectable driver bay
1157  *
1158  * If an acpi object is ejectable and has one of the ACPI ATA methods defined,
1159  * then we can safely call it an ejectable drive bay
1160  */
1161 bool acpi_bay_match(acpi_handle handle)
1162 {
1163         acpi_handle phandle;
1164
1165         if (!acpi_has_method(handle, "_EJ0"))
1166                 return false;
1167         if (acpi_ata_match(handle))
1168                 return true;
1169         if (ACPI_FAILURE(acpi_get_parent(handle, &phandle)))
1170                 return false;
1171
1172         return acpi_ata_match(phandle);
1173 }
1174
1175 bool acpi_device_is_battery(struct acpi_device *adev)
1176 {
1177         struct acpi_hardware_id *hwid;
1178
1179         list_for_each_entry(hwid, &adev->pnp.ids, list)
1180                 if (!strcmp("PNP0C0A", hwid->id))
1181                         return true;
1182
1183         return false;
1184 }
1185
1186 static bool is_ejectable_bay(struct acpi_device *adev)
1187 {
1188         acpi_handle handle = adev->handle;
1189
1190         if (acpi_has_method(handle, "_EJ0") && acpi_device_is_battery(adev))
1191                 return true;
1192
1193         return acpi_bay_match(handle);
1194 }
1195
1196 /*
1197  * acpi_dock_match - see if an acpi object has a _DCK method
1198  */
1199 bool acpi_dock_match(acpi_handle handle)
1200 {
1201         return acpi_has_method(handle, "_DCK");
1202 }
1203
1204 static acpi_status
1205 acpi_backlight_cap_match(acpi_handle handle, u32 level, void *context,
1206                           void **return_value)
1207 {
1208         long *cap = context;
1209
1210         if (acpi_has_method(handle, "_BCM") &&
1211             acpi_has_method(handle, "_BCL")) {
1212                 acpi_handle_debug(handle, "Found generic backlight support\n");
1213                 *cap |= ACPI_VIDEO_BACKLIGHT;
1214                 /* We have backlight support, no need to scan further */
1215                 return AE_CTRL_TERMINATE;
1216         }
1217         return 0;
1218 }
1219
1220 /* Returns true if the ACPI object is a video device which can be
1221  * handled by video.ko.
1222  * The device will get a Linux specific CID added in scan.c to
1223  * identify the device as an ACPI graphics device
1224  * Be aware that the graphics device may not be physically present
1225  * Use acpi_video_get_capabilities() to detect general ACPI video
1226  * capabilities of present cards
1227  */
1228 long acpi_is_video_device(acpi_handle handle)
1229 {
1230         long video_caps = 0;
1231
1232         /* Is this device able to support video switching ? */
1233         if (acpi_has_method(handle, "_DOD") || acpi_has_method(handle, "_DOS"))
1234                 video_caps |= ACPI_VIDEO_OUTPUT_SWITCHING;
1235
1236         /* Is this device able to retrieve a video ROM ? */
1237         if (acpi_has_method(handle, "_ROM"))
1238                 video_caps |= ACPI_VIDEO_ROM_AVAILABLE;
1239
1240         /* Is this device able to configure which video head to be POSTed ? */
1241         if (acpi_has_method(handle, "_VPO") &&
1242             acpi_has_method(handle, "_GPD") &&
1243             acpi_has_method(handle, "_SPD"))
1244                 video_caps |= ACPI_VIDEO_DEVICE_POSTING;
1245
1246         /* Only check for backlight functionality if one of the above hit. */
1247         if (video_caps)
1248                 acpi_walk_namespace(ACPI_TYPE_DEVICE, handle,
1249                                     ACPI_UINT32_MAX, acpi_backlight_cap_match, NULL,
1250                                     &video_caps, NULL);
1251
1252         return video_caps;
1253 }
1254 EXPORT_SYMBOL(acpi_is_video_device);
1255
1256 const char *acpi_device_hid(struct acpi_device *device)
1257 {
1258         struct acpi_hardware_id *hid;
1259
1260         if (list_empty(&device->pnp.ids))
1261                 return dummy_hid;
1262
1263         hid = list_first_entry(&device->pnp.ids, struct acpi_hardware_id, list);
1264         return hid->id;
1265 }
1266 EXPORT_SYMBOL(acpi_device_hid);
1267
1268 static void acpi_add_id(struct acpi_device_pnp *pnp, const char *dev_id)
1269 {
1270         struct acpi_hardware_id *id;
1271
1272         id = kmalloc(sizeof(*id), GFP_KERNEL);
1273         if (!id)
1274                 return;
1275
1276         id->id = kstrdup_const(dev_id, GFP_KERNEL);
1277         if (!id->id) {
1278                 kfree(id);
1279                 return;
1280         }
1281
1282         list_add_tail(&id->list, &pnp->ids);
1283         pnp->type.hardware_id = 1;
1284 }
1285
1286 /*
1287  * Old IBM workstations have a DSDT bug wherein the SMBus object
1288  * lacks the SMBUS01 HID and the methods do not have the necessary "_"
1289  * prefix.  Work around this.
1290  */
1291 static bool acpi_ibm_smbus_match(acpi_handle handle)
1292 {
1293         char node_name[ACPI_PATH_SEGMENT_LENGTH];
1294         struct acpi_buffer path = { sizeof(node_name), node_name };
1295
1296         if (!dmi_name_in_vendors("IBM"))
1297                 return false;
1298
1299         /* Look for SMBS object */
1300         if (ACPI_FAILURE(acpi_get_name(handle, ACPI_SINGLE_NAME, &path)) ||
1301             strcmp("SMBS", path.pointer))
1302                 return false;
1303
1304         /* Does it have the necessary (but misnamed) methods? */
1305         if (acpi_has_method(handle, "SBI") &&
1306             acpi_has_method(handle, "SBR") &&
1307             acpi_has_method(handle, "SBW"))
1308                 return true;
1309
1310         return false;
1311 }
1312
1313 static bool acpi_object_is_system_bus(acpi_handle handle)
1314 {
1315         acpi_handle tmp;
1316
1317         if (ACPI_SUCCESS(acpi_get_handle(NULL, "\\_SB", &tmp)) &&
1318             tmp == handle)
1319                 return true;
1320         if (ACPI_SUCCESS(acpi_get_handle(NULL, "\\_TZ", &tmp)) &&
1321             tmp == handle)
1322                 return true;
1323
1324         return false;
1325 }
1326
1327 static void acpi_set_pnp_ids(acpi_handle handle, struct acpi_device_pnp *pnp,
1328                              int device_type)
1329 {
1330         struct acpi_device_info *info = NULL;
1331         struct acpi_pnp_device_id_list *cid_list;
1332         int i;
1333
1334         switch (device_type) {
1335         case ACPI_BUS_TYPE_DEVICE:
1336                 if (handle == ACPI_ROOT_OBJECT) {
1337                         acpi_add_id(pnp, ACPI_SYSTEM_HID);
1338                         break;
1339                 }
1340
1341                 acpi_get_object_info(handle, &info);
1342                 if (!info) {
1343                         pr_err("%s: Error reading device info\n", __func__);
1344                         return;
1345                 }
1346
1347                 if (info->valid & ACPI_VALID_HID) {
1348                         acpi_add_id(pnp, info->hardware_id.string);
1349                         pnp->type.platform_id = 1;
1350                 }
1351                 if (info->valid & ACPI_VALID_CID) {
1352                         cid_list = &info->compatible_id_list;
1353                         for (i = 0; i < cid_list->count; i++)
1354                                 acpi_add_id(pnp, cid_list->ids[i].string);
1355                 }
1356                 if (info->valid & ACPI_VALID_ADR) {
1357                         pnp->bus_address = info->address;
1358                         pnp->type.bus_address = 1;
1359                 }
1360                 if (info->valid & ACPI_VALID_UID)
1361                         pnp->unique_id = kstrdup(info->unique_id.string,
1362                                                         GFP_KERNEL);
1363                 if (info->valid & ACPI_VALID_CLS)
1364                         acpi_add_id(pnp, info->class_code.string);
1365
1366                 kfree(info);
1367
1368                 /*
1369                  * Some devices don't reliably have _HIDs & _CIDs, so add
1370                  * synthetic HIDs to make sure drivers can find them.
1371                  */
1372                 if (acpi_is_video_device(handle))
1373                         acpi_add_id(pnp, ACPI_VIDEO_HID);
1374                 else if (acpi_bay_match(handle))
1375                         acpi_add_id(pnp, ACPI_BAY_HID);
1376                 else if (acpi_dock_match(handle))
1377                         acpi_add_id(pnp, ACPI_DOCK_HID);
1378                 else if (acpi_ibm_smbus_match(handle))
1379                         acpi_add_id(pnp, ACPI_SMBUS_IBM_HID);
1380                 else if (list_empty(&pnp->ids) &&
1381                          acpi_object_is_system_bus(handle)) {
1382                         /* \_SB, \_TZ, LNXSYBUS */
1383                         acpi_add_id(pnp, ACPI_BUS_HID);
1384                         strcpy(pnp->device_name, ACPI_BUS_DEVICE_NAME);
1385                         strcpy(pnp->device_class, ACPI_BUS_CLASS);
1386                 }
1387
1388                 break;
1389         case ACPI_BUS_TYPE_POWER:
1390                 acpi_add_id(pnp, ACPI_POWER_HID);
1391                 break;
1392         case ACPI_BUS_TYPE_PROCESSOR:
1393                 acpi_add_id(pnp, ACPI_PROCESSOR_OBJECT_HID);
1394                 break;
1395         case ACPI_BUS_TYPE_THERMAL:
1396                 acpi_add_id(pnp, ACPI_THERMAL_HID);
1397                 break;
1398         case ACPI_BUS_TYPE_POWER_BUTTON:
1399                 acpi_add_id(pnp, ACPI_BUTTON_HID_POWERF);
1400                 break;
1401         case ACPI_BUS_TYPE_SLEEP_BUTTON:
1402                 acpi_add_id(pnp, ACPI_BUTTON_HID_SLEEPF);
1403                 break;
1404         case ACPI_BUS_TYPE_ECDT_EC:
1405                 acpi_add_id(pnp, ACPI_ECDT_HID);
1406                 break;
1407         }
1408 }
1409
1410 void acpi_free_pnp_ids(struct acpi_device_pnp *pnp)
1411 {
1412         struct acpi_hardware_id *id, *tmp;
1413
1414         list_for_each_entry_safe(id, tmp, &pnp->ids, list) {
1415                 kfree_const(id->id);
1416                 kfree(id);
1417         }
1418         kfree(pnp->unique_id);
1419 }
1420
1421 /**
1422  * acpi_dma_supported - Check DMA support for the specified device.
1423  * @adev: The pointer to acpi device
1424  *
1425  * Return false if DMA is not supported. Otherwise, return true
1426  */
1427 bool acpi_dma_supported(const struct acpi_device *adev)
1428 {
1429         if (!adev)
1430                 return false;
1431
1432         if (adev->flags.cca_seen)
1433                 return true;
1434
1435         /*
1436         * Per ACPI 6.0 sec 6.2.17, assume devices can do cache-coherent
1437         * DMA on "Intel platforms".  Presumably that includes all x86 and
1438         * ia64, and other arches will set CONFIG_ACPI_CCA_REQUIRED=y.
1439         */
1440         if (!IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED))
1441                 return true;
1442
1443         return false;
1444 }
1445
1446 /**
1447  * acpi_get_dma_attr - Check the supported DMA attr for the specified device.
1448  * @adev: The pointer to acpi device
1449  *
1450  * Return enum dev_dma_attr.
1451  */
1452 enum dev_dma_attr acpi_get_dma_attr(struct acpi_device *adev)
1453 {
1454         if (!acpi_dma_supported(adev))
1455                 return DEV_DMA_NOT_SUPPORTED;
1456
1457         if (adev->flags.coherent_dma)
1458                 return DEV_DMA_COHERENT;
1459         else
1460                 return DEV_DMA_NON_COHERENT;
1461 }
1462
1463 /**
1464  * acpi_dma_get_range() - Get device DMA parameters.
1465  *
1466  * @dev: device to configure
1467  * @map: pointer to DMA ranges result
1468  *
1469  * Evaluate DMA regions and return pointer to DMA regions on
1470  * parsing success; it does not update the passed in values on failure.
1471  *
1472  * Return 0 on success, < 0 on failure.
1473  */
1474 int acpi_dma_get_range(struct device *dev, const struct bus_dma_region **map)
1475 {
1476         struct acpi_device *adev;
1477         LIST_HEAD(list);
1478         struct resource_entry *rentry;
1479         int ret;
1480         struct device *dma_dev = dev;
1481         struct bus_dma_region *r;
1482
1483         /*
1484          * Walk the device tree chasing an ACPI companion with a _DMA
1485          * object while we go. Stop if we find a device with an ACPI
1486          * companion containing a _DMA method.
1487          */
1488         do {
1489                 adev = ACPI_COMPANION(dma_dev);
1490                 if (adev && acpi_has_method(adev->handle, METHOD_NAME__DMA))
1491                         break;
1492
1493                 dma_dev = dma_dev->parent;
1494         } while (dma_dev);
1495
1496         if (!dma_dev)
1497                 return -ENODEV;
1498
1499         if (!acpi_has_method(adev->handle, METHOD_NAME__CRS)) {
1500                 acpi_handle_warn(adev->handle, "_DMA is valid only if _CRS is present\n");
1501                 return -EINVAL;
1502         }
1503
1504         ret = acpi_dev_get_dma_resources(adev, &list);
1505         if (ret > 0) {
1506                 r = kcalloc(ret + 1, sizeof(*r), GFP_KERNEL);
1507                 if (!r) {
1508                         ret = -ENOMEM;
1509                         goto out;
1510                 }
1511
1512                 list_for_each_entry(rentry, &list, node) {
1513                         if (rentry->res->start >= rentry->res->end) {
1514                                 kfree(r);
1515                                 ret = -EINVAL;
1516                                 dev_dbg(dma_dev, "Invalid DMA regions configuration\n");
1517                                 goto out;
1518                         }
1519
1520                         r->cpu_start = rentry->res->start;
1521                         r->dma_start = rentry->res->start - rentry->offset;
1522                         r->size = resource_size(rentry->res);
1523                         r->offset = rentry->offset;
1524                         r++;
1525                 }
1526
1527                 *map = r;
1528         }
1529  out:
1530         acpi_dev_free_resource_list(&list);
1531
1532         return ret >= 0 ? 0 : ret;
1533 }
1534
1535 #ifdef CONFIG_IOMMU_API
1536 int acpi_iommu_fwspec_init(struct device *dev, u32 id,
1537                            struct fwnode_handle *fwnode,
1538                            const struct iommu_ops *ops)
1539 {
1540         int ret = iommu_fwspec_init(dev, fwnode, ops);
1541
1542         if (!ret)
1543                 ret = iommu_fwspec_add_ids(dev, &id, 1);
1544
1545         return ret;
1546 }
1547
1548 static inline const struct iommu_ops *acpi_iommu_fwspec_ops(struct device *dev)
1549 {
1550         struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
1551
1552         return fwspec ? fwspec->ops : NULL;
1553 }
1554
1555 static const struct iommu_ops *acpi_iommu_configure_id(struct device *dev,
1556                                                        const u32 *id_in)
1557 {
1558         int err;
1559         const struct iommu_ops *ops;
1560
1561         /*
1562          * If we already translated the fwspec there is nothing left to do,
1563          * return the iommu_ops.
1564          */
1565         ops = acpi_iommu_fwspec_ops(dev);
1566         if (ops)
1567                 return ops;
1568
1569         err = iort_iommu_configure_id(dev, id_in);
1570         if (err && err != -EPROBE_DEFER)
1571                 err = viot_iommu_configure(dev);
1572
1573         /*
1574          * If we have reason to believe the IOMMU driver missed the initial
1575          * iommu_probe_device() call for dev, replay it to get things in order.
1576          */
1577         if (!err && dev->bus && !device_iommu_mapped(dev))
1578                 err = iommu_probe_device(dev);
1579
1580         /* Ignore all other errors apart from EPROBE_DEFER */
1581         if (err == -EPROBE_DEFER) {
1582                 return ERR_PTR(err);
1583         } else if (err) {
1584                 dev_dbg(dev, "Adding to IOMMU failed: %d\n", err);
1585                 return NULL;
1586         }
1587         return acpi_iommu_fwspec_ops(dev);
1588 }
1589
1590 #else /* !CONFIG_IOMMU_API */
1591
1592 int acpi_iommu_fwspec_init(struct device *dev, u32 id,
1593                            struct fwnode_handle *fwnode,
1594                            const struct iommu_ops *ops)
1595 {
1596         return -ENODEV;
1597 }
1598
1599 static const struct iommu_ops *acpi_iommu_configure_id(struct device *dev,
1600                                                        const u32 *id_in)
1601 {
1602         return NULL;
1603 }
1604
1605 #endif /* !CONFIG_IOMMU_API */
1606
1607 /**
1608  * acpi_dma_configure_id - Set-up DMA configuration for the device.
1609  * @dev: The pointer to the device
1610  * @attr: device dma attributes
1611  * @input_id: input device id const value pointer
1612  */
1613 int acpi_dma_configure_id(struct device *dev, enum dev_dma_attr attr,
1614                           const u32 *input_id)
1615 {
1616         const struct iommu_ops *iommu;
1617
1618         if (attr == DEV_DMA_NOT_SUPPORTED) {
1619                 set_dma_ops(dev, &dma_dummy_ops);
1620                 return 0;
1621         }
1622
1623         acpi_arch_dma_setup(dev);
1624
1625         iommu = acpi_iommu_configure_id(dev, input_id);
1626         if (PTR_ERR(iommu) == -EPROBE_DEFER)
1627                 return -EPROBE_DEFER;
1628
1629         arch_setup_dma_ops(dev, 0, U64_MAX,
1630                                 iommu, attr == DEV_DMA_COHERENT);
1631
1632         return 0;
1633 }
1634 EXPORT_SYMBOL_GPL(acpi_dma_configure_id);
1635
1636 static void acpi_init_coherency(struct acpi_device *adev)
1637 {
1638         unsigned long long cca = 0;
1639         acpi_status status;
1640         struct acpi_device *parent = acpi_dev_parent(adev);
1641
1642         if (parent && parent->flags.cca_seen) {
1643                 /*
1644                  * From ACPI spec, OSPM will ignore _CCA if an ancestor
1645                  * already saw one.
1646                  */
1647                 adev->flags.cca_seen = 1;
1648                 cca = parent->flags.coherent_dma;
1649         } else {
1650                 status = acpi_evaluate_integer(adev->handle, "_CCA",
1651                                                NULL, &cca);
1652                 if (ACPI_SUCCESS(status))
1653                         adev->flags.cca_seen = 1;
1654                 else if (!IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED))
1655                         /*
1656                          * If architecture does not specify that _CCA is
1657                          * required for DMA-able devices (e.g. x86),
1658                          * we default to _CCA=1.
1659                          */
1660                         cca = 1;
1661                 else
1662                         acpi_handle_debug(adev->handle,
1663                                           "ACPI device is missing _CCA.\n");
1664         }
1665
1666         adev->flags.coherent_dma = cca;
1667 }
1668
1669 static int acpi_check_serial_bus_slave(struct acpi_resource *ares, void *data)
1670 {
1671         bool *is_serial_bus_slave_p = data;
1672
1673         if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
1674                 return 1;
1675
1676         *is_serial_bus_slave_p = true;
1677
1678          /* no need to do more checking */
1679         return -1;
1680 }
1681
1682 static bool acpi_is_indirect_io_slave(struct acpi_device *device)
1683 {
1684         struct acpi_device *parent = acpi_dev_parent(device);
1685         static const struct acpi_device_id indirect_io_hosts[] = {
1686                 {"HISI0191", 0},
1687                 {}
1688         };
1689
1690         return parent && !acpi_match_device_ids(parent, indirect_io_hosts);
1691 }
1692
1693 static bool acpi_device_enumeration_by_parent(struct acpi_device *device)
1694 {
1695         struct list_head resource_list;
1696         bool is_serial_bus_slave = false;
1697         static const struct acpi_device_id ignore_serial_bus_ids[] = {
1698         /*
1699          * These devices have multiple SerialBus resources and a client
1700          * device must be instantiated for each of them, each with
1701          * its own device id.
1702          * Normally we only instantiate one client device for the first
1703          * resource, using the ACPI HID as id. These special cases are handled
1704          * by the drivers/platform/x86/serial-multi-instantiate.c driver, which
1705          * knows which client device id to use for each resource.
1706          */
1707                 {"BSG1160", },
1708                 {"BSG2150", },
1709                 {"CSC3551", },
1710                 {"INT33FE", },
1711                 {"INT3515", },
1712                 /* Non-conforming _HID for Cirrus Logic already released */
1713                 {"CLSA0100", },
1714                 {"CLSA0101", },
1715         /*
1716          * Some ACPI devs contain SerialBus resources even though they are not
1717          * attached to a serial bus at all.
1718          */
1719                 {"MSHW0028", },
1720         /*
1721          * HIDs of device with an UartSerialBusV2 resource for which userspace
1722          * expects a regular tty cdev to be created (instead of the in kernel
1723          * serdev) and which have a kernel driver which expects a platform_dev
1724          * such as the rfkill-gpio driver.
1725          */
1726                 {"BCM4752", },
1727                 {"LNV4752", },
1728                 {}
1729         };
1730
1731         if (acpi_is_indirect_io_slave(device))
1732                 return true;
1733
1734         /* Macs use device properties in lieu of _CRS resources */
1735         if (x86_apple_machine &&
1736             (fwnode_property_present(&device->fwnode, "spiSclkPeriod") ||
1737              fwnode_property_present(&device->fwnode, "i2cAddress") ||
1738              fwnode_property_present(&device->fwnode, "baud")))
1739                 return true;
1740
1741         if (!acpi_match_device_ids(device, ignore_serial_bus_ids))
1742                 return false;
1743
1744         INIT_LIST_HEAD(&resource_list);
1745         acpi_dev_get_resources(device, &resource_list,
1746                                acpi_check_serial_bus_slave,
1747                                &is_serial_bus_slave);
1748         acpi_dev_free_resource_list(&resource_list);
1749
1750         return is_serial_bus_slave;
1751 }
1752
1753 void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,
1754                              int type, void (*release)(struct device *))
1755 {
1756         struct acpi_device *parent = acpi_find_parent_acpi_dev(handle);
1757
1758         INIT_LIST_HEAD(&device->pnp.ids);
1759         device->device_type = type;
1760         device->handle = handle;
1761         device->dev.parent = parent ? &parent->dev : NULL;
1762         device->dev.release = release;
1763         device->dev.bus = &acpi_bus_type;
1764         fwnode_init(&device->fwnode, &acpi_device_fwnode_ops);
1765         acpi_set_device_status(device, ACPI_STA_DEFAULT);
1766         acpi_device_get_busid(device);
1767         acpi_set_pnp_ids(handle, &device->pnp, type);
1768         acpi_init_properties(device);
1769         acpi_bus_get_flags(device);
1770         device->flags.match_driver = false;
1771         device->flags.initialized = true;
1772         device->flags.enumeration_by_parent =
1773                 acpi_device_enumeration_by_parent(device);
1774         acpi_device_clear_enumerated(device);
1775         device_initialize(&device->dev);
1776         dev_set_uevent_suppress(&device->dev, true);
1777         acpi_init_coherency(device);
1778 }
1779
1780 static void acpi_scan_dep_init(struct acpi_device *adev)
1781 {
1782         struct acpi_dep_data *dep;
1783
1784         list_for_each_entry(dep, &acpi_dep_list, node) {
1785                 if (dep->consumer == adev->handle) {
1786                         if (dep->honor_dep)
1787                                 adev->flags.honor_deps = 1;
1788
1789                         adev->dep_unmet++;
1790                 }
1791         }
1792 }
1793
1794 void acpi_device_add_finalize(struct acpi_device *device)
1795 {
1796         dev_set_uevent_suppress(&device->dev, false);
1797         kobject_uevent(&device->dev.kobj, KOBJ_ADD);
1798 }
1799
1800 static void acpi_scan_init_status(struct acpi_device *adev)
1801 {
1802         if (acpi_bus_get_status(adev))
1803                 acpi_set_device_status(adev, 0);
1804 }
1805
1806 static int acpi_add_single_object(struct acpi_device **child,
1807                                   acpi_handle handle, int type, bool dep_init)
1808 {
1809         struct acpi_device *device;
1810         bool release_dep_lock = false;
1811         int result;
1812
1813         device = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
1814         if (!device)
1815                 return -ENOMEM;
1816
1817         acpi_init_device_object(device, handle, type, acpi_device_release);
1818         /*
1819          * Getting the status is delayed till here so that we can call
1820          * acpi_bus_get_status() and use its quirk handling.  Note that
1821          * this must be done before the get power-/wakeup_dev-flags calls.
1822          */
1823         if (type == ACPI_BUS_TYPE_DEVICE || type == ACPI_BUS_TYPE_PROCESSOR) {
1824                 if (dep_init) {
1825                         mutex_lock(&acpi_dep_list_lock);
1826                         /*
1827                          * Hold the lock until the acpi_tie_acpi_dev() call
1828                          * below to prevent concurrent acpi_scan_clear_dep()
1829                          * from deleting a dependency list entry without
1830                          * updating dep_unmet for the device.
1831                          */
1832                         release_dep_lock = true;
1833                         acpi_scan_dep_init(device);
1834                 }
1835                 acpi_scan_init_status(device);
1836         }
1837
1838         acpi_bus_get_power_flags(device);
1839         acpi_bus_get_wakeup_device_flags(device);
1840
1841         result = acpi_tie_acpi_dev(device);
1842
1843         if (release_dep_lock)
1844                 mutex_unlock(&acpi_dep_list_lock);
1845
1846         if (!result)
1847                 result = acpi_device_add(device);
1848
1849         if (result) {
1850                 acpi_device_release(&device->dev);
1851                 return result;
1852         }
1853
1854         acpi_power_add_remove_device(device, true);
1855         acpi_device_add_finalize(device);
1856
1857         acpi_handle_debug(handle, "Added as %s, parent %s\n",
1858                           dev_name(&device->dev), device->dev.parent ?
1859                                 dev_name(device->dev.parent) : "(null)");
1860
1861         *child = device;
1862         return 0;
1863 }
1864
1865 static acpi_status acpi_get_resource_memory(struct acpi_resource *ares,
1866                                             void *context)
1867 {
1868         struct resource *res = context;
1869
1870         if (acpi_dev_resource_memory(ares, res))
1871                 return AE_CTRL_TERMINATE;
1872
1873         return AE_OK;
1874 }
1875
1876 static bool acpi_device_should_be_hidden(acpi_handle handle)
1877 {
1878         acpi_status status;
1879         struct resource res;
1880
1881         /* Check if it should ignore the UART device */
1882         if (!(spcr_uart_addr && acpi_has_method(handle, METHOD_NAME__CRS)))
1883                 return false;
1884
1885         /*
1886          * The UART device described in SPCR table is assumed to have only one
1887          * memory resource present. So we only look for the first one here.
1888          */
1889         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1890                                      acpi_get_resource_memory, &res);
1891         if (ACPI_FAILURE(status) || res.start != spcr_uart_addr)
1892                 return false;
1893
1894         acpi_handle_info(handle, "The UART device @%pa in SPCR table will be hidden\n",
1895                          &res.start);
1896
1897         return true;
1898 }
1899
1900 bool acpi_device_is_present(const struct acpi_device *adev)
1901 {
1902         return adev->status.present || adev->status.functional;
1903 }
1904
1905 static bool acpi_scan_handler_matching(struct acpi_scan_handler *handler,
1906                                        const char *idstr,
1907                                        const struct acpi_device_id **matchid)
1908 {
1909         const struct acpi_device_id *devid;
1910
1911         if (handler->match)
1912                 return handler->match(idstr, matchid);
1913
1914         for (devid = handler->ids; devid->id[0]; devid++)
1915                 if (!strcmp((char *)devid->id, idstr)) {
1916                         if (matchid)
1917                                 *matchid = devid;
1918
1919                         return true;
1920                 }
1921
1922         return false;
1923 }
1924
1925 static struct acpi_scan_handler *acpi_scan_match_handler(const char *idstr,
1926                                         const struct acpi_device_id **matchid)
1927 {
1928         struct acpi_scan_handler *handler;
1929
1930         list_for_each_entry(handler, &acpi_scan_handlers_list, list_node)
1931                 if (acpi_scan_handler_matching(handler, idstr, matchid))
1932                         return handler;
1933
1934         return NULL;
1935 }
1936
1937 void acpi_scan_hotplug_enabled(struct acpi_hotplug_profile *hotplug, bool val)
1938 {
1939         if (!!hotplug->enabled == !!val)
1940                 return;
1941
1942         mutex_lock(&acpi_scan_lock);
1943
1944         hotplug->enabled = val;
1945
1946         mutex_unlock(&acpi_scan_lock);
1947 }
1948
1949 static void acpi_scan_init_hotplug(struct acpi_device *adev)
1950 {
1951         struct acpi_hardware_id *hwid;
1952
1953         if (acpi_dock_match(adev->handle) || is_ejectable_bay(adev)) {
1954                 acpi_dock_add(adev);
1955                 return;
1956         }
1957         list_for_each_entry(hwid, &adev->pnp.ids, list) {
1958                 struct acpi_scan_handler *handler;
1959
1960                 handler = acpi_scan_match_handler(hwid->id, NULL);
1961                 if (handler) {
1962                         adev->flags.hotplug_notify = true;
1963                         break;
1964                 }
1965         }
1966 }
1967
1968 static u32 acpi_scan_check_dep(acpi_handle handle, bool check_dep)
1969 {
1970         struct acpi_handle_list dep_devices;
1971         acpi_status status;
1972         u32 count;
1973         int i;
1974
1975         /*
1976          * Check for _HID here to avoid deferring the enumeration of:
1977          * 1. PCI devices.
1978          * 2. ACPI nodes describing USB ports.
1979          * Still, checking for _HID catches more then just these cases ...
1980          */
1981         if (!check_dep || !acpi_has_method(handle, "_DEP") ||
1982             !acpi_has_method(handle, "_HID"))
1983                 return 0;
1984
1985         status = acpi_evaluate_reference(handle, "_DEP", NULL, &dep_devices);
1986         if (ACPI_FAILURE(status)) {
1987                 acpi_handle_debug(handle, "Failed to evaluate _DEP.\n");
1988                 return 0;
1989         }
1990
1991         for (count = 0, i = 0; i < dep_devices.count; i++) {
1992                 struct acpi_device_info *info;
1993                 struct acpi_dep_data *dep;
1994                 bool skip, honor_dep;
1995
1996                 status = acpi_get_object_info(dep_devices.handles[i], &info);
1997                 if (ACPI_FAILURE(status)) {
1998                         acpi_handle_debug(handle, "Error reading _DEP device info\n");
1999                         continue;
2000                 }
2001
2002                 skip = acpi_info_matches_ids(info, acpi_ignore_dep_ids);
2003                 honor_dep = acpi_info_matches_ids(info, acpi_honor_dep_ids);
2004                 kfree(info);
2005
2006                 if (skip)
2007                         continue;
2008
2009                 dep = kzalloc(sizeof(*dep), GFP_KERNEL);
2010                 if (!dep)
2011                         continue;
2012
2013                 count++;
2014
2015                 dep->supplier = dep_devices.handles[i];
2016                 dep->consumer = handle;
2017                 dep->honor_dep = honor_dep;
2018
2019                 mutex_lock(&acpi_dep_list_lock);
2020                 list_add_tail(&dep->node , &acpi_dep_list);
2021                 mutex_unlock(&acpi_dep_list_lock);
2022         }
2023
2024         return count;
2025 }
2026
2027 static bool acpi_bus_scan_second_pass;
2028
2029 static acpi_status acpi_bus_check_add(acpi_handle handle, bool check_dep,
2030                                       struct acpi_device **adev_p)
2031 {
2032         struct acpi_device *device = acpi_fetch_acpi_dev(handle);
2033         acpi_object_type acpi_type;
2034         int type;
2035
2036         if (device)
2037                 goto out;
2038
2039         if (ACPI_FAILURE(acpi_get_type(handle, &acpi_type)))
2040                 return AE_OK;
2041
2042         switch (acpi_type) {
2043         case ACPI_TYPE_DEVICE:
2044                 if (acpi_device_should_be_hidden(handle))
2045                         return AE_OK;
2046
2047                 /* Bail out if there are dependencies. */
2048                 if (acpi_scan_check_dep(handle, check_dep) > 0) {
2049                         acpi_bus_scan_second_pass = true;
2050                         return AE_CTRL_DEPTH;
2051                 }
2052
2053                 fallthrough;
2054         case ACPI_TYPE_ANY:     /* for ACPI_ROOT_OBJECT */
2055                 type = ACPI_BUS_TYPE_DEVICE;
2056                 break;
2057
2058         case ACPI_TYPE_PROCESSOR:
2059                 type = ACPI_BUS_TYPE_PROCESSOR;
2060                 break;
2061
2062         case ACPI_TYPE_THERMAL:
2063                 type = ACPI_BUS_TYPE_THERMAL;
2064                 break;
2065
2066         case ACPI_TYPE_POWER:
2067                 acpi_add_power_resource(handle);
2068                 fallthrough;
2069         default:
2070                 return AE_OK;
2071         }
2072
2073         /*
2074          * If check_dep is true at this point, the device has no dependencies,
2075          * or the creation of the device object would have been postponed above.
2076          */
2077         acpi_add_single_object(&device, handle, type, !check_dep);
2078         if (!device)
2079                 return AE_CTRL_DEPTH;
2080
2081         acpi_scan_init_hotplug(device);
2082
2083 out:
2084         if (!*adev_p)
2085                 *adev_p = device;
2086
2087         return AE_OK;
2088 }
2089
2090 static acpi_status acpi_bus_check_add_1(acpi_handle handle, u32 lvl_not_used,
2091                                         void *not_used, void **ret_p)
2092 {
2093         return acpi_bus_check_add(handle, true, (struct acpi_device **)ret_p);
2094 }
2095
2096 static acpi_status acpi_bus_check_add_2(acpi_handle handle, u32 lvl_not_used,
2097                                         void *not_used, void **ret_p)
2098 {
2099         return acpi_bus_check_add(handle, false, (struct acpi_device **)ret_p);
2100 }
2101
2102 static void acpi_default_enumeration(struct acpi_device *device)
2103 {
2104         /*
2105          * Do not enumerate devices with enumeration_by_parent flag set as
2106          * they will be enumerated by their respective parents.
2107          */
2108         if (!device->flags.enumeration_by_parent) {
2109                 acpi_create_platform_device(device, NULL);
2110                 acpi_device_set_enumerated(device);
2111         } else {
2112                 blocking_notifier_call_chain(&acpi_reconfig_chain,
2113                                              ACPI_RECONFIG_DEVICE_ADD, device);
2114         }
2115 }
2116
2117 static const struct acpi_device_id generic_device_ids[] = {
2118         {ACPI_DT_NAMESPACE_HID, },
2119         {"", },
2120 };
2121
2122 static int acpi_generic_device_attach(struct acpi_device *adev,
2123                                       const struct acpi_device_id *not_used)
2124 {
2125         /*
2126          * Since ACPI_DT_NAMESPACE_HID is the only ID handled here, the test
2127          * below can be unconditional.
2128          */
2129         if (adev->data.of_compatible)
2130                 acpi_default_enumeration(adev);
2131
2132         return 1;
2133 }
2134
2135 static struct acpi_scan_handler generic_device_handler = {
2136         .ids = generic_device_ids,
2137         .attach = acpi_generic_device_attach,
2138 };
2139
2140 static int acpi_scan_attach_handler(struct acpi_device *device)
2141 {
2142         struct acpi_hardware_id *hwid;
2143         int ret = 0;
2144
2145         list_for_each_entry(hwid, &device->pnp.ids, list) {
2146                 const struct acpi_device_id *devid;
2147                 struct acpi_scan_handler *handler;
2148
2149                 handler = acpi_scan_match_handler(hwid->id, &devid);
2150                 if (handler) {
2151                         if (!handler->attach) {
2152                                 device->pnp.type.platform_id = 0;
2153                                 continue;
2154                         }
2155                         device->handler = handler;
2156                         ret = handler->attach(device, devid);
2157                         if (ret > 0)
2158                                 break;
2159
2160                         device->handler = NULL;
2161                         if (ret < 0)
2162                                 break;
2163                 }
2164         }
2165
2166         return ret;
2167 }
2168
2169 static int acpi_bus_attach(struct acpi_device *device, void *first_pass)
2170 {
2171         bool skip = !first_pass && device->flags.visited;
2172         acpi_handle ejd;
2173         int ret;
2174
2175         if (skip)
2176                 goto ok;
2177
2178         if (ACPI_SUCCESS(acpi_bus_get_ejd(device->handle, &ejd)))
2179                 register_dock_dependent_device(device, ejd);
2180
2181         acpi_bus_get_status(device);
2182         /* Skip devices that are not ready for enumeration (e.g. not present) */
2183         if (!acpi_dev_ready_for_enumeration(device)) {
2184                 device->flags.initialized = false;
2185                 acpi_device_clear_enumerated(device);
2186                 device->flags.power_manageable = 0;
2187                 return 0;
2188         }
2189         if (device->handler)
2190                 goto ok;
2191
2192         if (!device->flags.initialized) {
2193                 device->flags.power_manageable =
2194                         device->power.states[ACPI_STATE_D0].flags.valid;
2195                 if (acpi_bus_init_power(device))
2196                         device->flags.power_manageable = 0;
2197
2198                 device->flags.initialized = true;
2199         } else if (device->flags.visited) {
2200                 goto ok;
2201         }
2202
2203         ret = acpi_scan_attach_handler(device);
2204         if (ret < 0)
2205                 return 0;
2206
2207         device->flags.match_driver = true;
2208         if (ret > 0 && !device->flags.enumeration_by_parent) {
2209                 acpi_device_set_enumerated(device);
2210                 goto ok;
2211         }
2212
2213         ret = device_attach(&device->dev);
2214         if (ret < 0)
2215                 return 0;
2216
2217         if (device->pnp.type.platform_id || device->flags.enumeration_by_parent)
2218                 acpi_default_enumeration(device);
2219         else
2220                 acpi_device_set_enumerated(device);
2221
2222 ok:
2223         acpi_dev_for_each_child(device, acpi_bus_attach, first_pass);
2224
2225         if (!skip && device->handler && device->handler->hotplug.notify_online)
2226                 device->handler->hotplug.notify_online(device);
2227
2228         return 0;
2229 }
2230
2231 static int acpi_dev_get_next_consumer_dev_cb(struct acpi_dep_data *dep, void *data)
2232 {
2233         struct acpi_device **adev_p = data;
2234         struct acpi_device *adev = *adev_p;
2235
2236         /*
2237          * If we're passed a 'previous' consumer device then we need to skip
2238          * any consumers until we meet the previous one, and then NULL @data
2239          * so the next one can be returned.
2240          */
2241         if (adev) {
2242                 if (dep->consumer == adev->handle)
2243                         *adev_p = NULL;
2244
2245                 return 0;
2246         }
2247
2248         adev = acpi_get_acpi_dev(dep->consumer);
2249         if (adev) {
2250                 *(struct acpi_device **)data = adev;
2251                 return 1;
2252         }
2253         /* Continue parsing if the device object is not present. */
2254         return 0;
2255 }
2256
2257 struct acpi_scan_clear_dep_work {
2258         struct work_struct work;
2259         struct acpi_device *adev;
2260 };
2261
2262 static void acpi_scan_clear_dep_fn(struct work_struct *work)
2263 {
2264         struct acpi_scan_clear_dep_work *cdw;
2265
2266         cdw = container_of(work, struct acpi_scan_clear_dep_work, work);
2267
2268         acpi_scan_lock_acquire();
2269         acpi_bus_attach(cdw->adev, (void *)true);
2270         acpi_scan_lock_release();
2271
2272         acpi_dev_put(cdw->adev);
2273         kfree(cdw);
2274 }
2275
2276 static bool acpi_scan_clear_dep_queue(struct acpi_device *adev)
2277 {
2278         struct acpi_scan_clear_dep_work *cdw;
2279
2280         if (adev->dep_unmet)
2281                 return false;
2282
2283         cdw = kmalloc(sizeof(*cdw), GFP_KERNEL);
2284         if (!cdw)
2285                 return false;
2286
2287         cdw->adev = adev;
2288         INIT_WORK(&cdw->work, acpi_scan_clear_dep_fn);
2289         /*
2290          * Since the work function may block on the lock until the entire
2291          * initial enumeration of devices is complete, put it into the unbound
2292          * workqueue.
2293          */
2294         queue_work(system_unbound_wq, &cdw->work);
2295
2296         return true;
2297 }
2298
2299 static int acpi_scan_clear_dep(struct acpi_dep_data *dep, void *data)
2300 {
2301         struct acpi_device *adev = acpi_get_acpi_dev(dep->consumer);
2302
2303         if (adev) {
2304                 adev->dep_unmet--;
2305                 if (!acpi_scan_clear_dep_queue(adev))
2306                         acpi_dev_put(adev);
2307         }
2308
2309         list_del(&dep->node);
2310         kfree(dep);
2311
2312         return 0;
2313 }
2314
2315 /**
2316  * acpi_walk_dep_device_list - Apply a callback to every entry in acpi_dep_list
2317  * @handle:     The ACPI handle of the supplier device
2318  * @callback:   Pointer to the callback function to apply
2319  * @data:       Pointer to some data to pass to the callback
2320  *
2321  * The return value of the callback determines this function's behaviour. If 0
2322  * is returned we continue to iterate over acpi_dep_list. If a positive value
2323  * is returned then the loop is broken but this function returns 0. If a
2324  * negative value is returned by the callback then the loop is broken and that
2325  * value is returned as the final error.
2326  */
2327 static int acpi_walk_dep_device_list(acpi_handle handle,
2328                                 int (*callback)(struct acpi_dep_data *, void *),
2329                                 void *data)
2330 {
2331         struct acpi_dep_data *dep, *tmp;
2332         int ret = 0;
2333
2334         mutex_lock(&acpi_dep_list_lock);
2335         list_for_each_entry_safe(dep, tmp, &acpi_dep_list, node) {
2336                 if (dep->supplier == handle) {
2337                         ret = callback(dep, data);
2338                         if (ret)
2339                                 break;
2340                 }
2341         }
2342         mutex_unlock(&acpi_dep_list_lock);
2343
2344         return ret > 0 ? 0 : ret;
2345 }
2346
2347 /**
2348  * acpi_dev_clear_dependencies - Inform consumers that the device is now active
2349  * @supplier: Pointer to the supplier &struct acpi_device
2350  *
2351  * Clear dependencies on the given device.
2352  */
2353 void acpi_dev_clear_dependencies(struct acpi_device *supplier)
2354 {
2355         acpi_walk_dep_device_list(supplier->handle, acpi_scan_clear_dep, NULL);
2356 }
2357 EXPORT_SYMBOL_GPL(acpi_dev_clear_dependencies);
2358
2359 /**
2360  * acpi_dev_ready_for_enumeration - Check if the ACPI device is ready for enumeration
2361  * @device: Pointer to the &struct acpi_device to check
2362  *
2363  * Check if the device is present and has no unmet dependencies.
2364  *
2365  * Return true if the device is ready for enumeratino. Otherwise, return false.
2366  */
2367 bool acpi_dev_ready_for_enumeration(const struct acpi_device *device)
2368 {
2369         if (device->flags.honor_deps && device->dep_unmet)
2370                 return false;
2371
2372         return acpi_device_is_present(device);
2373 }
2374 EXPORT_SYMBOL_GPL(acpi_dev_ready_for_enumeration);
2375
2376 /**
2377  * acpi_dev_get_next_consumer_dev - Return the next adev dependent on @supplier
2378  * @supplier: Pointer to the dependee device
2379  * @start: Pointer to the current dependent device
2380  *
2381  * Returns the next &struct acpi_device which declares itself dependent on
2382  * @supplier via the _DEP buffer, parsed from the acpi_dep_list.
2383  *
2384  * If the returned adev is not passed as @start to this function, the caller is
2385  * responsible for putting the reference to adev when it is no longer needed.
2386  */
2387 struct acpi_device *acpi_dev_get_next_consumer_dev(struct acpi_device *supplier,
2388                                                    struct acpi_device *start)
2389 {
2390         struct acpi_device *adev = start;
2391
2392         acpi_walk_dep_device_list(supplier->handle,
2393                                   acpi_dev_get_next_consumer_dev_cb, &adev);
2394
2395         acpi_dev_put(start);
2396
2397         if (adev == start)
2398                 return NULL;
2399
2400         return adev;
2401 }
2402 EXPORT_SYMBOL_GPL(acpi_dev_get_next_consumer_dev);
2403
2404 /**
2405  * acpi_bus_scan - Add ACPI device node objects in a given namespace scope.
2406  * @handle: Root of the namespace scope to scan.
2407  *
2408  * Scan a given ACPI tree (probably recently hot-plugged) and create and add
2409  * found devices.
2410  *
2411  * If no devices were found, -ENODEV is returned, but it does not mean that
2412  * there has been a real error.  There just have been no suitable ACPI objects
2413  * in the table trunk from which the kernel could create a device and add an
2414  * appropriate driver.
2415  *
2416  * Must be called under acpi_scan_lock.
2417  */
2418 int acpi_bus_scan(acpi_handle handle)
2419 {
2420         struct acpi_device *device = NULL;
2421
2422         acpi_bus_scan_second_pass = false;
2423
2424         /* Pass 1: Avoid enumerating devices with missing dependencies. */
2425
2426         if (ACPI_SUCCESS(acpi_bus_check_add(handle, true, &device)))
2427                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
2428                                     acpi_bus_check_add_1, NULL, NULL,
2429                                     (void **)&device);
2430
2431         if (!device)
2432                 return -ENODEV;
2433
2434         acpi_bus_attach(device, (void *)true);
2435
2436         if (!acpi_bus_scan_second_pass)
2437                 return 0;
2438
2439         /* Pass 2: Enumerate all of the remaining devices. */
2440
2441         device = NULL;
2442
2443         if (ACPI_SUCCESS(acpi_bus_check_add(handle, false, &device)))
2444                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
2445                                     acpi_bus_check_add_2, NULL, NULL,
2446                                     (void **)&device);
2447
2448         acpi_bus_attach(device, NULL);
2449
2450         return 0;
2451 }
2452 EXPORT_SYMBOL(acpi_bus_scan);
2453
2454 static int acpi_bus_trim_one(struct acpi_device *adev, void *not_used)
2455 {
2456         struct acpi_scan_handler *handler = adev->handler;
2457
2458         acpi_dev_for_each_child_reverse(adev, acpi_bus_trim_one, NULL);
2459
2460         adev->flags.match_driver = false;
2461         if (handler) {
2462                 if (handler->detach)
2463                         handler->detach(adev);
2464
2465                 adev->handler = NULL;
2466         } else {
2467                 device_release_driver(&adev->dev);
2468         }
2469         /*
2470          * Most likely, the device is going away, so put it into D3cold before
2471          * that.
2472          */
2473         acpi_device_set_power(adev, ACPI_STATE_D3_COLD);
2474         adev->flags.initialized = false;
2475         acpi_device_clear_enumerated(adev);
2476
2477         return 0;
2478 }
2479
2480 /**
2481  * acpi_bus_trim - Detach scan handlers and drivers from ACPI device objects.
2482  * @adev: Root of the ACPI namespace scope to walk.
2483  *
2484  * Must be called under acpi_scan_lock.
2485  */
2486 void acpi_bus_trim(struct acpi_device *adev)
2487 {
2488         acpi_bus_trim_one(adev, NULL);
2489 }
2490 EXPORT_SYMBOL_GPL(acpi_bus_trim);
2491
2492 int acpi_bus_register_early_device(int type)
2493 {
2494         struct acpi_device *device = NULL;
2495         int result;
2496
2497         result = acpi_add_single_object(&device, NULL, type, false);
2498         if (result)
2499                 return result;
2500
2501         device->flags.match_driver = true;
2502         return device_attach(&device->dev);
2503 }
2504 EXPORT_SYMBOL_GPL(acpi_bus_register_early_device);
2505
2506 static void acpi_bus_scan_fixed(void)
2507 {
2508         if (!(acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON)) {
2509                 struct acpi_device *adev = NULL;
2510
2511                 acpi_add_single_object(&adev, NULL, ACPI_BUS_TYPE_POWER_BUTTON,
2512                                        false);
2513                 if (adev) {
2514                         adev->flags.match_driver = true;
2515                         if (device_attach(&adev->dev) >= 0)
2516                                 device_init_wakeup(&adev->dev, true);
2517                         else
2518                                 dev_dbg(&adev->dev, "No driver\n");
2519                 }
2520         }
2521
2522         if (!(acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON)) {
2523                 struct acpi_device *adev = NULL;
2524
2525                 acpi_add_single_object(&adev, NULL, ACPI_BUS_TYPE_SLEEP_BUTTON,
2526                                        false);
2527                 if (adev) {
2528                         adev->flags.match_driver = true;
2529                         if (device_attach(&adev->dev) < 0)
2530                                 dev_dbg(&adev->dev, "No driver\n");
2531                 }
2532         }
2533 }
2534
2535 static void __init acpi_get_spcr_uart_addr(void)
2536 {
2537         acpi_status status;
2538         struct acpi_table_spcr *spcr_ptr;
2539
2540         status = acpi_get_table(ACPI_SIG_SPCR, 0,
2541                                 (struct acpi_table_header **)&spcr_ptr);
2542         if (ACPI_FAILURE(status)) {
2543                 pr_warn("STAO table present, but SPCR is missing\n");
2544                 return;
2545         }
2546
2547         spcr_uart_addr = spcr_ptr->serial_port.address;
2548         acpi_put_table((struct acpi_table_header *)spcr_ptr);
2549 }
2550
2551 static bool acpi_scan_initialized;
2552
2553 void __init acpi_scan_init(void)
2554 {
2555         acpi_status status;
2556         struct acpi_table_stao *stao_ptr;
2557
2558         acpi_pci_root_init();
2559         acpi_pci_link_init();
2560         acpi_processor_init();
2561         acpi_platform_init();
2562         acpi_lpss_init();
2563         acpi_apd_init();
2564         acpi_cmos_rtc_init();
2565         acpi_container_init();
2566         acpi_memory_hotplug_init();
2567         acpi_watchdog_init();
2568         acpi_pnp_init();
2569         acpi_int340x_thermal_init();
2570         acpi_amba_init();
2571         acpi_init_lpit();
2572
2573         acpi_scan_add_handler(&generic_device_handler);
2574
2575         /*
2576          * If there is STAO table, check whether it needs to ignore the UART
2577          * device in SPCR table.
2578          */
2579         status = acpi_get_table(ACPI_SIG_STAO, 0,
2580                                 (struct acpi_table_header **)&stao_ptr);
2581         if (ACPI_SUCCESS(status)) {
2582                 if (stao_ptr->header.length > sizeof(struct acpi_table_stao))
2583                         pr_info("STAO Name List not yet supported.\n");
2584
2585                 if (stao_ptr->ignore_uart)
2586                         acpi_get_spcr_uart_addr();
2587
2588                 acpi_put_table((struct acpi_table_header *)stao_ptr);
2589         }
2590
2591         acpi_gpe_apply_masked_gpes();
2592         acpi_update_all_gpes();
2593
2594         /*
2595          * Although we call __add_memory() that is documented to require the
2596          * device_hotplug_lock, it is not necessary here because this is an
2597          * early code when userspace or any other code path cannot trigger
2598          * hotplug/hotunplug operations.
2599          */
2600         mutex_lock(&acpi_scan_lock);
2601         /*
2602          * Enumerate devices in the ACPI namespace.
2603          */
2604         if (acpi_bus_scan(ACPI_ROOT_OBJECT))
2605                 goto unlock;
2606
2607         acpi_root = acpi_fetch_acpi_dev(ACPI_ROOT_OBJECT);
2608         if (!acpi_root)
2609                 goto unlock;
2610
2611         /* Fixed feature devices do not exist on HW-reduced platform */
2612         if (!acpi_gbl_reduced_hardware)
2613                 acpi_bus_scan_fixed();
2614
2615         acpi_turn_off_unused_power_resources();
2616
2617         acpi_scan_initialized = true;
2618
2619 unlock:
2620         mutex_unlock(&acpi_scan_lock);
2621 }
2622
2623 static struct acpi_probe_entry *ape;
2624 static int acpi_probe_count;
2625 static DEFINE_MUTEX(acpi_probe_mutex);
2626
2627 static int __init acpi_match_madt(union acpi_subtable_headers *header,
2628                                   const unsigned long end)
2629 {
2630         if (!ape->subtable_valid || ape->subtable_valid(&header->common, ape))
2631                 if (!ape->probe_subtbl(header, end))
2632                         acpi_probe_count++;
2633
2634         return 0;
2635 }
2636
2637 int __init __acpi_probe_device_table(struct acpi_probe_entry *ap_head, int nr)
2638 {
2639         int count = 0;
2640
2641         if (acpi_disabled)
2642                 return 0;
2643
2644         mutex_lock(&acpi_probe_mutex);
2645         for (ape = ap_head; nr; ape++, nr--) {
2646                 if (ACPI_COMPARE_NAMESEG(ACPI_SIG_MADT, ape->id)) {
2647                         acpi_probe_count = 0;
2648                         acpi_table_parse_madt(ape->type, acpi_match_madt, 0);
2649                         count += acpi_probe_count;
2650                 } else {
2651                         int res;
2652                         res = acpi_table_parse(ape->id, ape->probe_table);
2653                         if (!res)
2654                                 count++;
2655                 }
2656         }
2657         mutex_unlock(&acpi_probe_mutex);
2658
2659         return count;
2660 }
2661
2662 static void acpi_table_events_fn(struct work_struct *work)
2663 {
2664         acpi_scan_lock_acquire();
2665         acpi_bus_scan(ACPI_ROOT_OBJECT);
2666         acpi_scan_lock_release();
2667
2668         kfree(work);
2669 }
2670
2671 void acpi_scan_table_notify(void)
2672 {
2673         struct work_struct *work;
2674
2675         if (!acpi_scan_initialized)
2676                 return;
2677
2678         work = kmalloc(sizeof(*work), GFP_KERNEL);
2679         if (!work)
2680                 return;
2681
2682         INIT_WORK(work, acpi_table_events_fn);
2683         schedule_work(work);
2684 }
2685
2686 int acpi_reconfig_notifier_register(struct notifier_block *nb)
2687 {
2688         return blocking_notifier_chain_register(&acpi_reconfig_chain, nb);
2689 }
2690 EXPORT_SYMBOL(acpi_reconfig_notifier_register);
2691
2692 int acpi_reconfig_notifier_unregister(struct notifier_block *nb)
2693 {
2694         return blocking_notifier_chain_unregister(&acpi_reconfig_chain, nb);
2695 }
2696 EXPORT_SYMBOL(acpi_reconfig_notifier_unregister);