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                 *map = r;
1513
1514                 list_for_each_entry(rentry, &list, node) {
1515                         if (rentry->res->start >= rentry->res->end) {
1516                                 kfree(*map);
1517                                 *map = NULL;
1518                                 ret = -EINVAL;
1519                                 dev_dbg(dma_dev, "Invalid DMA regions configuration\n");
1520                                 goto out;
1521                         }
1522
1523                         r->cpu_start = rentry->res->start;
1524                         r->dma_start = rentry->res->start - rentry->offset;
1525                         r->size = resource_size(rentry->res);
1526                         r->offset = rentry->offset;
1527                         r++;
1528                 }
1529         }
1530  out:
1531         acpi_dev_free_resource_list(&list);
1532
1533         return ret >= 0 ? 0 : ret;
1534 }
1535
1536 #ifdef CONFIG_IOMMU_API
1537 int acpi_iommu_fwspec_init(struct device *dev, u32 id,
1538                            struct fwnode_handle *fwnode,
1539                            const struct iommu_ops *ops)
1540 {
1541         int ret = iommu_fwspec_init(dev, fwnode, ops);
1542
1543         if (!ret)
1544                 ret = iommu_fwspec_add_ids(dev, &id, 1);
1545
1546         return ret;
1547 }
1548
1549 static inline const struct iommu_ops *acpi_iommu_fwspec_ops(struct device *dev)
1550 {
1551         struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
1552
1553         return fwspec ? fwspec->ops : NULL;
1554 }
1555
1556 static const struct iommu_ops *acpi_iommu_configure_id(struct device *dev,
1557                                                        const u32 *id_in)
1558 {
1559         int err;
1560         const struct iommu_ops *ops;
1561
1562         /*
1563          * If we already translated the fwspec there is nothing left to do,
1564          * return the iommu_ops.
1565          */
1566         ops = acpi_iommu_fwspec_ops(dev);
1567         if (ops)
1568                 return ops;
1569
1570         err = iort_iommu_configure_id(dev, id_in);
1571         if (err && err != -EPROBE_DEFER)
1572                 err = viot_iommu_configure(dev);
1573
1574         /*
1575          * If we have reason to believe the IOMMU driver missed the initial
1576          * iommu_probe_device() call for dev, replay it to get things in order.
1577          */
1578         if (!err && dev->bus && !device_iommu_mapped(dev))
1579                 err = iommu_probe_device(dev);
1580
1581         /* Ignore all other errors apart from EPROBE_DEFER */
1582         if (err == -EPROBE_DEFER) {
1583                 return ERR_PTR(err);
1584         } else if (err) {
1585                 dev_dbg(dev, "Adding to IOMMU failed: %d\n", err);
1586                 return NULL;
1587         }
1588         return acpi_iommu_fwspec_ops(dev);
1589 }
1590
1591 #else /* !CONFIG_IOMMU_API */
1592
1593 int acpi_iommu_fwspec_init(struct device *dev, u32 id,
1594                            struct fwnode_handle *fwnode,
1595                            const struct iommu_ops *ops)
1596 {
1597         return -ENODEV;
1598 }
1599
1600 static const struct iommu_ops *acpi_iommu_configure_id(struct device *dev,
1601                                                        const u32 *id_in)
1602 {
1603         return NULL;
1604 }
1605
1606 #endif /* !CONFIG_IOMMU_API */
1607
1608 /**
1609  * acpi_dma_configure_id - Set-up DMA configuration for the device.
1610  * @dev: The pointer to the device
1611  * @attr: device dma attributes
1612  * @input_id: input device id const value pointer
1613  */
1614 int acpi_dma_configure_id(struct device *dev, enum dev_dma_attr attr,
1615                           const u32 *input_id)
1616 {
1617         const struct iommu_ops *iommu;
1618
1619         if (attr == DEV_DMA_NOT_SUPPORTED) {
1620                 set_dma_ops(dev, &dma_dummy_ops);
1621                 return 0;
1622         }
1623
1624         acpi_arch_dma_setup(dev);
1625
1626         iommu = acpi_iommu_configure_id(dev, input_id);
1627         if (PTR_ERR(iommu) == -EPROBE_DEFER)
1628                 return -EPROBE_DEFER;
1629
1630         arch_setup_dma_ops(dev, 0, U64_MAX,
1631                                 iommu, attr == DEV_DMA_COHERENT);
1632
1633         return 0;
1634 }
1635 EXPORT_SYMBOL_GPL(acpi_dma_configure_id);
1636
1637 static void acpi_init_coherency(struct acpi_device *adev)
1638 {
1639         unsigned long long cca = 0;
1640         acpi_status status;
1641         struct acpi_device *parent = acpi_dev_parent(adev);
1642
1643         if (parent && parent->flags.cca_seen) {
1644                 /*
1645                  * From ACPI spec, OSPM will ignore _CCA if an ancestor
1646                  * already saw one.
1647                  */
1648                 adev->flags.cca_seen = 1;
1649                 cca = parent->flags.coherent_dma;
1650         } else {
1651                 status = acpi_evaluate_integer(adev->handle, "_CCA",
1652                                                NULL, &cca);
1653                 if (ACPI_SUCCESS(status))
1654                         adev->flags.cca_seen = 1;
1655                 else if (!IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED))
1656                         /*
1657                          * If architecture does not specify that _CCA is
1658                          * required for DMA-able devices (e.g. x86),
1659                          * we default to _CCA=1.
1660                          */
1661                         cca = 1;
1662                 else
1663                         acpi_handle_debug(adev->handle,
1664                                           "ACPI device is missing _CCA.\n");
1665         }
1666
1667         adev->flags.coherent_dma = cca;
1668 }
1669
1670 static int acpi_check_serial_bus_slave(struct acpi_resource *ares, void *data)
1671 {
1672         bool *is_serial_bus_slave_p = data;
1673
1674         if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
1675                 return 1;
1676
1677         *is_serial_bus_slave_p = true;
1678
1679          /* no need to do more checking */
1680         return -1;
1681 }
1682
1683 static bool acpi_is_indirect_io_slave(struct acpi_device *device)
1684 {
1685         struct acpi_device *parent = acpi_dev_parent(device);
1686         static const struct acpi_device_id indirect_io_hosts[] = {
1687                 {"HISI0191", 0},
1688                 {}
1689         };
1690
1691         return parent && !acpi_match_device_ids(parent, indirect_io_hosts);
1692 }
1693
1694 static bool acpi_device_enumeration_by_parent(struct acpi_device *device)
1695 {
1696         struct list_head resource_list;
1697         bool is_serial_bus_slave = false;
1698         static const struct acpi_device_id ignore_serial_bus_ids[] = {
1699         /*
1700          * These devices have multiple SerialBus resources and a client
1701          * device must be instantiated for each of them, each with
1702          * its own device id.
1703          * Normally we only instantiate one client device for the first
1704          * resource, using the ACPI HID as id. These special cases are handled
1705          * by the drivers/platform/x86/serial-multi-instantiate.c driver, which
1706          * knows which client device id to use for each resource.
1707          */
1708                 {"BSG1160", },
1709                 {"BSG2150", },
1710                 {"CSC3551", },
1711                 {"INT33FE", },
1712                 {"INT3515", },
1713                 /* Non-conforming _HID for Cirrus Logic already released */
1714                 {"CLSA0100", },
1715                 {"CLSA0101", },
1716         /*
1717          * Some ACPI devs contain SerialBus resources even though they are not
1718          * attached to a serial bus at all.
1719          */
1720                 {"MSHW0028", },
1721         /*
1722          * HIDs of device with an UartSerialBusV2 resource for which userspace
1723          * expects a regular tty cdev to be created (instead of the in kernel
1724          * serdev) and which have a kernel driver which expects a platform_dev
1725          * such as the rfkill-gpio driver.
1726          */
1727                 {"BCM4752", },
1728                 {"LNV4752", },
1729                 {}
1730         };
1731
1732         if (acpi_is_indirect_io_slave(device))
1733                 return true;
1734
1735         /* Macs use device properties in lieu of _CRS resources */
1736         if (x86_apple_machine &&
1737             (fwnode_property_present(&device->fwnode, "spiSclkPeriod") ||
1738              fwnode_property_present(&device->fwnode, "i2cAddress") ||
1739              fwnode_property_present(&device->fwnode, "baud")))
1740                 return true;
1741
1742         if (!acpi_match_device_ids(device, ignore_serial_bus_ids))
1743                 return false;
1744
1745         INIT_LIST_HEAD(&resource_list);
1746         acpi_dev_get_resources(device, &resource_list,
1747                                acpi_check_serial_bus_slave,
1748                                &is_serial_bus_slave);
1749         acpi_dev_free_resource_list(&resource_list);
1750
1751         return is_serial_bus_slave;
1752 }
1753
1754 void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,
1755                              int type, void (*release)(struct device *))
1756 {
1757         struct acpi_device *parent = acpi_find_parent_acpi_dev(handle);
1758
1759         INIT_LIST_HEAD(&device->pnp.ids);
1760         device->device_type = type;
1761         device->handle = handle;
1762         device->dev.parent = parent ? &parent->dev : NULL;
1763         device->dev.release = release;
1764         device->dev.bus = &acpi_bus_type;
1765         fwnode_init(&device->fwnode, &acpi_device_fwnode_ops);
1766         acpi_set_device_status(device, ACPI_STA_DEFAULT);
1767         acpi_device_get_busid(device);
1768         acpi_set_pnp_ids(handle, &device->pnp, type);
1769         acpi_init_properties(device);
1770         acpi_bus_get_flags(device);
1771         device->flags.match_driver = false;
1772         device->flags.initialized = true;
1773         device->flags.enumeration_by_parent =
1774                 acpi_device_enumeration_by_parent(device);
1775         acpi_device_clear_enumerated(device);
1776         device_initialize(&device->dev);
1777         dev_set_uevent_suppress(&device->dev, true);
1778         acpi_init_coherency(device);
1779 }
1780
1781 static void acpi_scan_dep_init(struct acpi_device *adev)
1782 {
1783         struct acpi_dep_data *dep;
1784
1785         list_for_each_entry(dep, &acpi_dep_list, node) {
1786                 if (dep->consumer == adev->handle) {
1787                         if (dep->honor_dep)
1788                                 adev->flags.honor_deps = 1;
1789
1790                         adev->dep_unmet++;
1791                 }
1792         }
1793 }
1794
1795 void acpi_device_add_finalize(struct acpi_device *device)
1796 {
1797         dev_set_uevent_suppress(&device->dev, false);
1798         kobject_uevent(&device->dev.kobj, KOBJ_ADD);
1799 }
1800
1801 static void acpi_scan_init_status(struct acpi_device *adev)
1802 {
1803         if (acpi_bus_get_status(adev))
1804                 acpi_set_device_status(adev, 0);
1805 }
1806
1807 static int acpi_add_single_object(struct acpi_device **child,
1808                                   acpi_handle handle, int type, bool dep_init)
1809 {
1810         struct acpi_device *device;
1811         bool release_dep_lock = false;
1812         int result;
1813
1814         device = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
1815         if (!device)
1816                 return -ENOMEM;
1817
1818         acpi_init_device_object(device, handle, type, acpi_device_release);
1819         /*
1820          * Getting the status is delayed till here so that we can call
1821          * acpi_bus_get_status() and use its quirk handling.  Note that
1822          * this must be done before the get power-/wakeup_dev-flags calls.
1823          */
1824         if (type == ACPI_BUS_TYPE_DEVICE || type == ACPI_BUS_TYPE_PROCESSOR) {
1825                 if (dep_init) {
1826                         mutex_lock(&acpi_dep_list_lock);
1827                         /*
1828                          * Hold the lock until the acpi_tie_acpi_dev() call
1829                          * below to prevent concurrent acpi_scan_clear_dep()
1830                          * from deleting a dependency list entry without
1831                          * updating dep_unmet for the device.
1832                          */
1833                         release_dep_lock = true;
1834                         acpi_scan_dep_init(device);
1835                 }
1836                 acpi_scan_init_status(device);
1837         }
1838
1839         acpi_bus_get_power_flags(device);
1840         acpi_bus_get_wakeup_device_flags(device);
1841
1842         result = acpi_tie_acpi_dev(device);
1843
1844         if (release_dep_lock)
1845                 mutex_unlock(&acpi_dep_list_lock);
1846
1847         if (!result)
1848                 result = acpi_device_add(device);
1849
1850         if (result) {
1851                 acpi_device_release(&device->dev);
1852                 return result;
1853         }
1854
1855         acpi_power_add_remove_device(device, true);
1856         acpi_device_add_finalize(device);
1857
1858         acpi_handle_debug(handle, "Added as %s, parent %s\n",
1859                           dev_name(&device->dev), device->dev.parent ?
1860                                 dev_name(device->dev.parent) : "(null)");
1861
1862         *child = device;
1863         return 0;
1864 }
1865
1866 static acpi_status acpi_get_resource_memory(struct acpi_resource *ares,
1867                                             void *context)
1868 {
1869         struct resource *res = context;
1870
1871         if (acpi_dev_resource_memory(ares, res))
1872                 return AE_CTRL_TERMINATE;
1873
1874         return AE_OK;
1875 }
1876
1877 static bool acpi_device_should_be_hidden(acpi_handle handle)
1878 {
1879         acpi_status status;
1880         struct resource res;
1881
1882         /* Check if it should ignore the UART device */
1883         if (!(spcr_uart_addr && acpi_has_method(handle, METHOD_NAME__CRS)))
1884                 return false;
1885
1886         /*
1887          * The UART device described in SPCR table is assumed to have only one
1888          * memory resource present. So we only look for the first one here.
1889          */
1890         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1891                                      acpi_get_resource_memory, &res);
1892         if (ACPI_FAILURE(status) || res.start != spcr_uart_addr)
1893                 return false;
1894
1895         acpi_handle_info(handle, "The UART device @%pa in SPCR table will be hidden\n",
1896                          &res.start);
1897
1898         return true;
1899 }
1900
1901 bool acpi_device_is_present(const struct acpi_device *adev)
1902 {
1903         return adev->status.present || adev->status.functional;
1904 }
1905
1906 static bool acpi_scan_handler_matching(struct acpi_scan_handler *handler,
1907                                        const char *idstr,
1908                                        const struct acpi_device_id **matchid)
1909 {
1910         const struct acpi_device_id *devid;
1911
1912         if (handler->match)
1913                 return handler->match(idstr, matchid);
1914
1915         for (devid = handler->ids; devid->id[0]; devid++)
1916                 if (!strcmp((char *)devid->id, idstr)) {
1917                         if (matchid)
1918                                 *matchid = devid;
1919
1920                         return true;
1921                 }
1922
1923         return false;
1924 }
1925
1926 static struct acpi_scan_handler *acpi_scan_match_handler(const char *idstr,
1927                                         const struct acpi_device_id **matchid)
1928 {
1929         struct acpi_scan_handler *handler;
1930
1931         list_for_each_entry(handler, &acpi_scan_handlers_list, list_node)
1932                 if (acpi_scan_handler_matching(handler, idstr, matchid))
1933                         return handler;
1934
1935         return NULL;
1936 }
1937
1938 void acpi_scan_hotplug_enabled(struct acpi_hotplug_profile *hotplug, bool val)
1939 {
1940         if (!!hotplug->enabled == !!val)
1941                 return;
1942
1943         mutex_lock(&acpi_scan_lock);
1944
1945         hotplug->enabled = val;
1946
1947         mutex_unlock(&acpi_scan_lock);
1948 }
1949
1950 static void acpi_scan_init_hotplug(struct acpi_device *adev)
1951 {
1952         struct acpi_hardware_id *hwid;
1953
1954         if (acpi_dock_match(adev->handle) || is_ejectable_bay(adev)) {
1955                 acpi_dock_add(adev);
1956                 return;
1957         }
1958         list_for_each_entry(hwid, &adev->pnp.ids, list) {
1959                 struct acpi_scan_handler *handler;
1960
1961                 handler = acpi_scan_match_handler(hwid->id, NULL);
1962                 if (handler) {
1963                         adev->flags.hotplug_notify = true;
1964                         break;
1965                 }
1966         }
1967 }
1968
1969 static u32 acpi_scan_check_dep(acpi_handle handle, bool check_dep)
1970 {
1971         struct acpi_handle_list dep_devices;
1972         acpi_status status;
1973         u32 count;
1974         int i;
1975
1976         /*
1977          * Check for _HID here to avoid deferring the enumeration of:
1978          * 1. PCI devices.
1979          * 2. ACPI nodes describing USB ports.
1980          * Still, checking for _HID catches more then just these cases ...
1981          */
1982         if (!check_dep || !acpi_has_method(handle, "_DEP") ||
1983             !acpi_has_method(handle, "_HID"))
1984                 return 0;
1985
1986         status = acpi_evaluate_reference(handle, "_DEP", NULL, &dep_devices);
1987         if (ACPI_FAILURE(status)) {
1988                 acpi_handle_debug(handle, "Failed to evaluate _DEP.\n");
1989                 return 0;
1990         }
1991
1992         for (count = 0, i = 0; i < dep_devices.count; i++) {
1993                 struct acpi_device_info *info;
1994                 struct acpi_dep_data *dep;
1995                 bool skip, honor_dep;
1996
1997                 status = acpi_get_object_info(dep_devices.handles[i], &info);
1998                 if (ACPI_FAILURE(status)) {
1999                         acpi_handle_debug(handle, "Error reading _DEP device info\n");
2000                         continue;
2001                 }
2002
2003                 skip = acpi_info_matches_ids(info, acpi_ignore_dep_ids);
2004                 honor_dep = acpi_info_matches_ids(info, acpi_honor_dep_ids);
2005                 kfree(info);
2006
2007                 if (skip)
2008                         continue;
2009
2010                 dep = kzalloc(sizeof(*dep), GFP_KERNEL);
2011                 if (!dep)
2012                         continue;
2013
2014                 count++;
2015
2016                 dep->supplier = dep_devices.handles[i];
2017                 dep->consumer = handle;
2018                 dep->honor_dep = honor_dep;
2019
2020                 mutex_lock(&acpi_dep_list_lock);
2021                 list_add_tail(&dep->node , &acpi_dep_list);
2022                 mutex_unlock(&acpi_dep_list_lock);
2023         }
2024
2025         return count;
2026 }
2027
2028 static bool acpi_bus_scan_second_pass;
2029
2030 static acpi_status acpi_bus_check_add(acpi_handle handle, bool check_dep,
2031                                       struct acpi_device **adev_p)
2032 {
2033         struct acpi_device *device = acpi_fetch_acpi_dev(handle);
2034         acpi_object_type acpi_type;
2035         int type;
2036
2037         if (device)
2038                 goto out;
2039
2040         if (ACPI_FAILURE(acpi_get_type(handle, &acpi_type)))
2041                 return AE_OK;
2042
2043         switch (acpi_type) {
2044         case ACPI_TYPE_DEVICE:
2045                 if (acpi_device_should_be_hidden(handle))
2046                         return AE_OK;
2047
2048                 /* Bail out if there are dependencies. */
2049                 if (acpi_scan_check_dep(handle, check_dep) > 0) {
2050                         acpi_bus_scan_second_pass = true;
2051                         return AE_CTRL_DEPTH;
2052                 }
2053
2054                 fallthrough;
2055         case ACPI_TYPE_ANY:     /* for ACPI_ROOT_OBJECT */
2056                 type = ACPI_BUS_TYPE_DEVICE;
2057                 break;
2058
2059         case ACPI_TYPE_PROCESSOR:
2060                 type = ACPI_BUS_TYPE_PROCESSOR;
2061                 break;
2062
2063         case ACPI_TYPE_THERMAL:
2064                 type = ACPI_BUS_TYPE_THERMAL;
2065                 break;
2066
2067         case ACPI_TYPE_POWER:
2068                 acpi_add_power_resource(handle);
2069                 fallthrough;
2070         default:
2071                 return AE_OK;
2072         }
2073
2074         /*
2075          * If check_dep is true at this point, the device has no dependencies,
2076          * or the creation of the device object would have been postponed above.
2077          */
2078         acpi_add_single_object(&device, handle, type, !check_dep);
2079         if (!device)
2080                 return AE_CTRL_DEPTH;
2081
2082         acpi_scan_init_hotplug(device);
2083
2084 out:
2085         if (!*adev_p)
2086                 *adev_p = device;
2087
2088         return AE_OK;
2089 }
2090
2091 static acpi_status acpi_bus_check_add_1(acpi_handle handle, u32 lvl_not_used,
2092                                         void *not_used, void **ret_p)
2093 {
2094         return acpi_bus_check_add(handle, true, (struct acpi_device **)ret_p);
2095 }
2096
2097 static acpi_status acpi_bus_check_add_2(acpi_handle handle, u32 lvl_not_used,
2098                                         void *not_used, void **ret_p)
2099 {
2100         return acpi_bus_check_add(handle, false, (struct acpi_device **)ret_p);
2101 }
2102
2103 static void acpi_default_enumeration(struct acpi_device *device)
2104 {
2105         /*
2106          * Do not enumerate devices with enumeration_by_parent flag set as
2107          * they will be enumerated by their respective parents.
2108          */
2109         if (!device->flags.enumeration_by_parent) {
2110                 acpi_create_platform_device(device, NULL);
2111                 acpi_device_set_enumerated(device);
2112         } else {
2113                 blocking_notifier_call_chain(&acpi_reconfig_chain,
2114                                              ACPI_RECONFIG_DEVICE_ADD, device);
2115         }
2116 }
2117
2118 static const struct acpi_device_id generic_device_ids[] = {
2119         {ACPI_DT_NAMESPACE_HID, },
2120         {"", },
2121 };
2122
2123 static int acpi_generic_device_attach(struct acpi_device *adev,
2124                                       const struct acpi_device_id *not_used)
2125 {
2126         /*
2127          * Since ACPI_DT_NAMESPACE_HID is the only ID handled here, the test
2128          * below can be unconditional.
2129          */
2130         if (adev->data.of_compatible)
2131                 acpi_default_enumeration(adev);
2132
2133         return 1;
2134 }
2135
2136 static struct acpi_scan_handler generic_device_handler = {
2137         .ids = generic_device_ids,
2138         .attach = acpi_generic_device_attach,
2139 };
2140
2141 static int acpi_scan_attach_handler(struct acpi_device *device)
2142 {
2143         struct acpi_hardware_id *hwid;
2144         int ret = 0;
2145
2146         list_for_each_entry(hwid, &device->pnp.ids, list) {
2147                 const struct acpi_device_id *devid;
2148                 struct acpi_scan_handler *handler;
2149
2150                 handler = acpi_scan_match_handler(hwid->id, &devid);
2151                 if (handler) {
2152                         if (!handler->attach) {
2153                                 device->pnp.type.platform_id = 0;
2154                                 continue;
2155                         }
2156                         device->handler = handler;
2157                         ret = handler->attach(device, devid);
2158                         if (ret > 0)
2159                                 break;
2160
2161                         device->handler = NULL;
2162                         if (ret < 0)
2163                                 break;
2164                 }
2165         }
2166
2167         return ret;
2168 }
2169
2170 static int acpi_bus_attach(struct acpi_device *device, void *first_pass)
2171 {
2172         bool skip = !first_pass && device->flags.visited;
2173         acpi_handle ejd;
2174         int ret;
2175
2176         if (skip)
2177                 goto ok;
2178
2179         if (ACPI_SUCCESS(acpi_bus_get_ejd(device->handle, &ejd)))
2180                 register_dock_dependent_device(device, ejd);
2181
2182         acpi_bus_get_status(device);
2183         /* Skip devices that are not ready for enumeration (e.g. not present) */
2184         if (!acpi_dev_ready_for_enumeration(device)) {
2185                 device->flags.initialized = false;
2186                 acpi_device_clear_enumerated(device);
2187                 device->flags.power_manageable = 0;
2188                 return 0;
2189         }
2190         if (device->handler)
2191                 goto ok;
2192
2193         if (!device->flags.initialized) {
2194                 device->flags.power_manageable =
2195                         device->power.states[ACPI_STATE_D0].flags.valid;
2196                 if (acpi_bus_init_power(device))
2197                         device->flags.power_manageable = 0;
2198
2199                 device->flags.initialized = true;
2200         } else if (device->flags.visited) {
2201                 goto ok;
2202         }
2203
2204         ret = acpi_scan_attach_handler(device);
2205         if (ret < 0)
2206                 return 0;
2207
2208         device->flags.match_driver = true;
2209         if (ret > 0 && !device->flags.enumeration_by_parent) {
2210                 acpi_device_set_enumerated(device);
2211                 goto ok;
2212         }
2213
2214         ret = device_attach(&device->dev);
2215         if (ret < 0)
2216                 return 0;
2217
2218         if (device->pnp.type.platform_id || device->flags.enumeration_by_parent)
2219                 acpi_default_enumeration(device);
2220         else
2221                 acpi_device_set_enumerated(device);
2222
2223 ok:
2224         acpi_dev_for_each_child(device, acpi_bus_attach, first_pass);
2225
2226         if (!skip && device->handler && device->handler->hotplug.notify_online)
2227                 device->handler->hotplug.notify_online(device);
2228
2229         return 0;
2230 }
2231
2232 static int acpi_dev_get_next_consumer_dev_cb(struct acpi_dep_data *dep, void *data)
2233 {
2234         struct acpi_device **adev_p = data;
2235         struct acpi_device *adev = *adev_p;
2236
2237         /*
2238          * If we're passed a 'previous' consumer device then we need to skip
2239          * any consumers until we meet the previous one, and then NULL @data
2240          * so the next one can be returned.
2241          */
2242         if (adev) {
2243                 if (dep->consumer == adev->handle)
2244                         *adev_p = NULL;
2245
2246                 return 0;
2247         }
2248
2249         adev = acpi_get_acpi_dev(dep->consumer);
2250         if (adev) {
2251                 *(struct acpi_device **)data = adev;
2252                 return 1;
2253         }
2254         /* Continue parsing if the device object is not present. */
2255         return 0;
2256 }
2257
2258 struct acpi_scan_clear_dep_work {
2259         struct work_struct work;
2260         struct acpi_device *adev;
2261 };
2262
2263 static void acpi_scan_clear_dep_fn(struct work_struct *work)
2264 {
2265         struct acpi_scan_clear_dep_work *cdw;
2266
2267         cdw = container_of(work, struct acpi_scan_clear_dep_work, work);
2268
2269         acpi_scan_lock_acquire();
2270         acpi_bus_attach(cdw->adev, (void *)true);
2271         acpi_scan_lock_release();
2272
2273         acpi_dev_put(cdw->adev);
2274         kfree(cdw);
2275 }
2276
2277 static bool acpi_scan_clear_dep_queue(struct acpi_device *adev)
2278 {
2279         struct acpi_scan_clear_dep_work *cdw;
2280
2281         if (adev->dep_unmet)
2282                 return false;
2283
2284         cdw = kmalloc(sizeof(*cdw), GFP_KERNEL);
2285         if (!cdw)
2286                 return false;
2287
2288         cdw->adev = adev;
2289         INIT_WORK(&cdw->work, acpi_scan_clear_dep_fn);
2290         /*
2291          * Since the work function may block on the lock until the entire
2292          * initial enumeration of devices is complete, put it into the unbound
2293          * workqueue.
2294          */
2295         queue_work(system_unbound_wq, &cdw->work);
2296
2297         return true;
2298 }
2299
2300 static int acpi_scan_clear_dep(struct acpi_dep_data *dep, void *data)
2301 {
2302         struct acpi_device *adev = acpi_get_acpi_dev(dep->consumer);
2303
2304         if (adev) {
2305                 adev->dep_unmet--;
2306                 if (!acpi_scan_clear_dep_queue(adev))
2307                         acpi_dev_put(adev);
2308         }
2309
2310         list_del(&dep->node);
2311         kfree(dep);
2312
2313         return 0;
2314 }
2315
2316 /**
2317  * acpi_walk_dep_device_list - Apply a callback to every entry in acpi_dep_list
2318  * @handle:     The ACPI handle of the supplier device
2319  * @callback:   Pointer to the callback function to apply
2320  * @data:       Pointer to some data to pass to the callback
2321  *
2322  * The return value of the callback determines this function's behaviour. If 0
2323  * is returned we continue to iterate over acpi_dep_list. If a positive value
2324  * is returned then the loop is broken but this function returns 0. If a
2325  * negative value is returned by the callback then the loop is broken and that
2326  * value is returned as the final error.
2327  */
2328 static int acpi_walk_dep_device_list(acpi_handle handle,
2329                                 int (*callback)(struct acpi_dep_data *, void *),
2330                                 void *data)
2331 {
2332         struct acpi_dep_data *dep, *tmp;
2333         int ret = 0;
2334
2335         mutex_lock(&acpi_dep_list_lock);
2336         list_for_each_entry_safe(dep, tmp, &acpi_dep_list, node) {
2337                 if (dep->supplier == handle) {
2338                         ret = callback(dep, data);
2339                         if (ret)
2340                                 break;
2341                 }
2342         }
2343         mutex_unlock(&acpi_dep_list_lock);
2344
2345         return ret > 0 ? 0 : ret;
2346 }
2347
2348 /**
2349  * acpi_dev_clear_dependencies - Inform consumers that the device is now active
2350  * @supplier: Pointer to the supplier &struct acpi_device
2351  *
2352  * Clear dependencies on the given device.
2353  */
2354 void acpi_dev_clear_dependencies(struct acpi_device *supplier)
2355 {
2356         acpi_walk_dep_device_list(supplier->handle, acpi_scan_clear_dep, NULL);
2357 }
2358 EXPORT_SYMBOL_GPL(acpi_dev_clear_dependencies);
2359
2360 /**
2361  * acpi_dev_ready_for_enumeration - Check if the ACPI device is ready for enumeration
2362  * @device: Pointer to the &struct acpi_device to check
2363  *
2364  * Check if the device is present and has no unmet dependencies.
2365  *
2366  * Return true if the device is ready for enumeratino. Otherwise, return false.
2367  */
2368 bool acpi_dev_ready_for_enumeration(const struct acpi_device *device)
2369 {
2370         if (device->flags.honor_deps && device->dep_unmet)
2371                 return false;
2372
2373         return acpi_device_is_present(device);
2374 }
2375 EXPORT_SYMBOL_GPL(acpi_dev_ready_for_enumeration);
2376
2377 /**
2378  * acpi_dev_get_next_consumer_dev - Return the next adev dependent on @supplier
2379  * @supplier: Pointer to the dependee device
2380  * @start: Pointer to the current dependent device
2381  *
2382  * Returns the next &struct acpi_device which declares itself dependent on
2383  * @supplier via the _DEP buffer, parsed from the acpi_dep_list.
2384  *
2385  * If the returned adev is not passed as @start to this function, the caller is
2386  * responsible for putting the reference to adev when it is no longer needed.
2387  */
2388 struct acpi_device *acpi_dev_get_next_consumer_dev(struct acpi_device *supplier,
2389                                                    struct acpi_device *start)
2390 {
2391         struct acpi_device *adev = start;
2392
2393         acpi_walk_dep_device_list(supplier->handle,
2394                                   acpi_dev_get_next_consumer_dev_cb, &adev);
2395
2396         acpi_dev_put(start);
2397
2398         if (adev == start)
2399                 return NULL;
2400
2401         return adev;
2402 }
2403 EXPORT_SYMBOL_GPL(acpi_dev_get_next_consumer_dev);
2404
2405 /**
2406  * acpi_bus_scan - Add ACPI device node objects in a given namespace scope.
2407  * @handle: Root of the namespace scope to scan.
2408  *
2409  * Scan a given ACPI tree (probably recently hot-plugged) and create and add
2410  * found devices.
2411  *
2412  * If no devices were found, -ENODEV is returned, but it does not mean that
2413  * there has been a real error.  There just have been no suitable ACPI objects
2414  * in the table trunk from which the kernel could create a device and add an
2415  * appropriate driver.
2416  *
2417  * Must be called under acpi_scan_lock.
2418  */
2419 int acpi_bus_scan(acpi_handle handle)
2420 {
2421         struct acpi_device *device = NULL;
2422
2423         acpi_bus_scan_second_pass = false;
2424
2425         /* Pass 1: Avoid enumerating devices with missing dependencies. */
2426
2427         if (ACPI_SUCCESS(acpi_bus_check_add(handle, true, &device)))
2428                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
2429                                     acpi_bus_check_add_1, NULL, NULL,
2430                                     (void **)&device);
2431
2432         if (!device)
2433                 return -ENODEV;
2434
2435         acpi_bus_attach(device, (void *)true);
2436
2437         if (!acpi_bus_scan_second_pass)
2438                 return 0;
2439
2440         /* Pass 2: Enumerate all of the remaining devices. */
2441
2442         device = NULL;
2443
2444         if (ACPI_SUCCESS(acpi_bus_check_add(handle, false, &device)))
2445                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
2446                                     acpi_bus_check_add_2, NULL, NULL,
2447                                     (void **)&device);
2448
2449         acpi_bus_attach(device, NULL);
2450
2451         return 0;
2452 }
2453 EXPORT_SYMBOL(acpi_bus_scan);
2454
2455 static int acpi_bus_trim_one(struct acpi_device *adev, void *not_used)
2456 {
2457         struct acpi_scan_handler *handler = adev->handler;
2458
2459         acpi_dev_for_each_child_reverse(adev, acpi_bus_trim_one, NULL);
2460
2461         adev->flags.match_driver = false;
2462         if (handler) {
2463                 if (handler->detach)
2464                         handler->detach(adev);
2465
2466                 adev->handler = NULL;
2467         } else {
2468                 device_release_driver(&adev->dev);
2469         }
2470         /*
2471          * Most likely, the device is going away, so put it into D3cold before
2472          * that.
2473          */
2474         acpi_device_set_power(adev, ACPI_STATE_D3_COLD);
2475         adev->flags.initialized = false;
2476         acpi_device_clear_enumerated(adev);
2477
2478         return 0;
2479 }
2480
2481 /**
2482  * acpi_bus_trim - Detach scan handlers and drivers from ACPI device objects.
2483  * @adev: Root of the ACPI namespace scope to walk.
2484  *
2485  * Must be called under acpi_scan_lock.
2486  */
2487 void acpi_bus_trim(struct acpi_device *adev)
2488 {
2489         acpi_bus_trim_one(adev, NULL);
2490 }
2491 EXPORT_SYMBOL_GPL(acpi_bus_trim);
2492
2493 int acpi_bus_register_early_device(int type)
2494 {
2495         struct acpi_device *device = NULL;
2496         int result;
2497
2498         result = acpi_add_single_object(&device, NULL, type, false);
2499         if (result)
2500                 return result;
2501
2502         device->flags.match_driver = true;
2503         return device_attach(&device->dev);
2504 }
2505 EXPORT_SYMBOL_GPL(acpi_bus_register_early_device);
2506
2507 static void acpi_bus_scan_fixed(void)
2508 {
2509         if (!(acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON)) {
2510                 struct acpi_device *adev = NULL;
2511
2512                 acpi_add_single_object(&adev, NULL, ACPI_BUS_TYPE_POWER_BUTTON,
2513                                        false);
2514                 if (adev) {
2515                         adev->flags.match_driver = true;
2516                         if (device_attach(&adev->dev) >= 0)
2517                                 device_init_wakeup(&adev->dev, true);
2518                         else
2519                                 dev_dbg(&adev->dev, "No driver\n");
2520                 }
2521         }
2522
2523         if (!(acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON)) {
2524                 struct acpi_device *adev = NULL;
2525
2526                 acpi_add_single_object(&adev, NULL, ACPI_BUS_TYPE_SLEEP_BUTTON,
2527                                        false);
2528                 if (adev) {
2529                         adev->flags.match_driver = true;
2530                         if (device_attach(&adev->dev) < 0)
2531                                 dev_dbg(&adev->dev, "No driver\n");
2532                 }
2533         }
2534 }
2535
2536 static void __init acpi_get_spcr_uart_addr(void)
2537 {
2538         acpi_status status;
2539         struct acpi_table_spcr *spcr_ptr;
2540
2541         status = acpi_get_table(ACPI_SIG_SPCR, 0,
2542                                 (struct acpi_table_header **)&spcr_ptr);
2543         if (ACPI_FAILURE(status)) {
2544                 pr_warn("STAO table present, but SPCR is missing\n");
2545                 return;
2546         }
2547
2548         spcr_uart_addr = spcr_ptr->serial_port.address;
2549         acpi_put_table((struct acpi_table_header *)spcr_ptr);
2550 }
2551
2552 static bool acpi_scan_initialized;
2553
2554 void __init acpi_scan_init(void)
2555 {
2556         acpi_status status;
2557         struct acpi_table_stao *stao_ptr;
2558
2559         acpi_pci_root_init();
2560         acpi_pci_link_init();
2561         acpi_processor_init();
2562         acpi_platform_init();
2563         acpi_lpss_init();
2564         acpi_apd_init();
2565         acpi_cmos_rtc_init();
2566         acpi_container_init();
2567         acpi_memory_hotplug_init();
2568         acpi_watchdog_init();
2569         acpi_pnp_init();
2570         acpi_int340x_thermal_init();
2571         acpi_amba_init();
2572         acpi_init_lpit();
2573
2574         acpi_scan_add_handler(&generic_device_handler);
2575
2576         /*
2577          * If there is STAO table, check whether it needs to ignore the UART
2578          * device in SPCR table.
2579          */
2580         status = acpi_get_table(ACPI_SIG_STAO, 0,
2581                                 (struct acpi_table_header **)&stao_ptr);
2582         if (ACPI_SUCCESS(status)) {
2583                 if (stao_ptr->header.length > sizeof(struct acpi_table_stao))
2584                         pr_info("STAO Name List not yet supported.\n");
2585
2586                 if (stao_ptr->ignore_uart)
2587                         acpi_get_spcr_uart_addr();
2588
2589                 acpi_put_table((struct acpi_table_header *)stao_ptr);
2590         }
2591
2592         acpi_gpe_apply_masked_gpes();
2593         acpi_update_all_gpes();
2594
2595         /*
2596          * Although we call __add_memory() that is documented to require the
2597          * device_hotplug_lock, it is not necessary here because this is an
2598          * early code when userspace or any other code path cannot trigger
2599          * hotplug/hotunplug operations.
2600          */
2601         mutex_lock(&acpi_scan_lock);
2602         /*
2603          * Enumerate devices in the ACPI namespace.
2604          */
2605         if (acpi_bus_scan(ACPI_ROOT_OBJECT))
2606                 goto unlock;
2607
2608         acpi_root = acpi_fetch_acpi_dev(ACPI_ROOT_OBJECT);
2609         if (!acpi_root)
2610                 goto unlock;
2611
2612         /* Fixed feature devices do not exist on HW-reduced platform */
2613         if (!acpi_gbl_reduced_hardware)
2614                 acpi_bus_scan_fixed();
2615
2616         acpi_turn_off_unused_power_resources();
2617
2618         acpi_scan_initialized = true;
2619
2620 unlock:
2621         mutex_unlock(&acpi_scan_lock);
2622 }
2623
2624 static struct acpi_probe_entry *ape;
2625 static int acpi_probe_count;
2626 static DEFINE_MUTEX(acpi_probe_mutex);
2627
2628 static int __init acpi_match_madt(union acpi_subtable_headers *header,
2629                                   const unsigned long end)
2630 {
2631         if (!ape->subtable_valid || ape->subtable_valid(&header->common, ape))
2632                 if (!ape->probe_subtbl(header, end))
2633                         acpi_probe_count++;
2634
2635         return 0;
2636 }
2637
2638 int __init __acpi_probe_device_table(struct acpi_probe_entry *ap_head, int nr)
2639 {
2640         int count = 0;
2641
2642         if (acpi_disabled)
2643                 return 0;
2644
2645         mutex_lock(&acpi_probe_mutex);
2646         for (ape = ap_head; nr; ape++, nr--) {
2647                 if (ACPI_COMPARE_NAMESEG(ACPI_SIG_MADT, ape->id)) {
2648                         acpi_probe_count = 0;
2649                         acpi_table_parse_madt(ape->type, acpi_match_madt, 0);
2650                         count += acpi_probe_count;
2651                 } else {
2652                         int res;
2653                         res = acpi_table_parse(ape->id, ape->probe_table);
2654                         if (!res)
2655                                 count++;
2656                 }
2657         }
2658         mutex_unlock(&acpi_probe_mutex);
2659
2660         return count;
2661 }
2662
2663 static void acpi_table_events_fn(struct work_struct *work)
2664 {
2665         acpi_scan_lock_acquire();
2666         acpi_bus_scan(ACPI_ROOT_OBJECT);
2667         acpi_scan_lock_release();
2668
2669         kfree(work);
2670 }
2671
2672 void acpi_scan_table_notify(void)
2673 {
2674         struct work_struct *work;
2675
2676         if (!acpi_scan_initialized)
2677                 return;
2678
2679         work = kmalloc(sizeof(*work), GFP_KERNEL);
2680         if (!work)
2681                 return;
2682
2683         INIT_WORK(work, acpi_table_events_fn);
2684         schedule_work(work);
2685 }
2686
2687 int acpi_reconfig_notifier_register(struct notifier_block *nb)
2688 {
2689         return blocking_notifier_chain_register(&acpi_reconfig_chain, nb);
2690 }
2691 EXPORT_SYMBOL(acpi_reconfig_notifier_register);
2692
2693 int acpi_reconfig_notifier_unregister(struct notifier_block *nb)
2694 {
2695         return blocking_notifier_chain_unregister(&acpi_reconfig_chain, nb);
2696 }
2697 EXPORT_SYMBOL(acpi_reconfig_notifier_unregister);