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         "LATT2021", /* Lattice FW Update Client Driver */
 793         NULL
 794 };
 795
 796 /* List of HIDs for which we honor deps of matching ACPI devs, when checking _DEP lists. */
 797 static const char * const acpi_honor_dep_ids[] = {
 798         "INT3472", /* Camera sensor PMIC / clk and regulator info */
 799         NULL
 800 };
 801
 802 static struct acpi_device *acpi_find_parent_acpi_dev(acpi_handle handle)
 803 {
 804         struct acpi_device *adev;
 805
 806         /*
 807          * Fixed hardware devices do not appear in the namespace and do not
 808          * have handles, but we fabricate acpi_devices for them, so we have
 809          * to deal with them specially.
 810          */
 811         if (!handle)
 812                 return acpi_root;
 813
 814         do {
 815                 acpi_status status;
 816
 817                 status = acpi_get_parent(handle, &handle);
 818                 if (ACPI_FAILURE(status)) {
 819                         if (status != AE_NULL_ENTRY)
 820                                 return acpi_root;
 821
 822                         return NULL;
 823                 }
 824                 adev = acpi_fetch_acpi_dev(handle);
 825         } while (!adev);
 826         return adev;
 827 }
 828
 829 acpi_status
 830 acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
 831 {
 832         acpi_status status;
 833         acpi_handle tmp;
 834         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
 835         union acpi_object *obj;
 836
 837         status = acpi_get_handle(handle, "_EJD", &tmp);
 838         if (ACPI_FAILURE(status))
 839                 return status;
 840
 841         status = acpi_evaluate_object(handle, "_EJD", NULL, &buffer);
 842         if (ACPI_SUCCESS(status)) {
 843                 obj = buffer.pointer;
 844                 status = acpi_get_handle(ACPI_ROOT_OBJECT, obj->string.pointer,
 845                                          ejd);
 846                 kfree(buffer.pointer);
 847         }
 848         return status;
 849 }
 850 EXPORT_SYMBOL_GPL(acpi_bus_get_ejd);
 851
 852 static int acpi_bus_extract_wakeup_device_power_package(struct acpi_device *dev)
 853 {
 854         acpi_handle handle = dev->handle;
 855         struct acpi_device_wakeup *wakeup = &dev->wakeup;
 856         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 857         union acpi_object *package = NULL;
 858         union acpi_object *element = NULL;
 859         acpi_status status;
 860         int err = -ENODATA;
 861
 862         INIT_LIST_HEAD(&wakeup->resources);
 863
 864         /* _PRW */
 865         status = acpi_evaluate_object(handle, "_PRW", NULL, &buffer);
 866         if (ACPI_FAILURE(status)) {
 867                 acpi_handle_info(handle, "_PRW evaluation failed: %s\n",
 868                                  acpi_format_exception(status));
 869                 return err;
 870         }
 871
 872         package = (union acpi_object *)buffer.pointer;
 873
 874         if (!package || package->package.count < 2)
 875                 goto out;
 876
 877         element = &(package->package.elements[0]);
 878         if (!element)
 879                 goto out;
 880
 881         if (element->type == ACPI_TYPE_PACKAGE) {
 882                 if ((element->package.count < 2) ||
 883                     (element->package.elements[0].type !=
 884                      ACPI_TYPE_LOCAL_REFERENCE)
 885                     || (element->package.elements[1].type != ACPI_TYPE_INTEGER))
 886                         goto out;
 887
 888                 wakeup->gpe_device =
 889                     element->package.elements[0].reference.handle;
 890                 wakeup->gpe_number =
 891                     (u32) element->package.elements[1].integer.value;
 892         } else if (element->type == ACPI_TYPE_INTEGER) {
 893                 wakeup->gpe_device = NULL;
 894                 wakeup->gpe_number = element->integer.value;
 895         } else {
 896                 goto out;
 897         }
 898
 899         element = &(package->package.elements[1]);
 900         if (element->type != ACPI_TYPE_INTEGER)
 901                 goto out;
 902
 903         wakeup->sleep_state = element->integer.value;
 904
 905         err = acpi_extract_power_resources(package, 2, &wakeup->resources);
 906         if (err)
 907                 goto out;
 908
 909         if (!list_empty(&wakeup->resources)) {
 910                 int sleep_state;
 911
 912                 err = acpi_power_wakeup_list_init(&wakeup->resources,
 913                                                   &sleep_state);
 914                 if (err) {
 915                         acpi_handle_warn(handle, "Retrieving current states "
 916                                          "of wakeup power resources failed\n");
 917                         acpi_power_resources_list_free(&wakeup->resources);
 918                         goto out;
 919                 }
 920                 if (sleep_state < wakeup->sleep_state) {
 921                         acpi_handle_warn(handle, "Overriding _PRW sleep state "
 922                                          "(S%d) by S%d from power resources\n",
 923                                          (int)wakeup->sleep_state, sleep_state);
 924                         wakeup->sleep_state = sleep_state;
 925                 }
 926         }
 927
 928  out:
 929         kfree(buffer.pointer);
 930         return err;
 931 }
 932
 933 static bool acpi_wakeup_gpe_init(struct acpi_device *device)
 934 {
 935         static const struct acpi_device_id button_device_ids[] = {
 936                 {"PNP0C0C", 0},         /* Power button */
 937                 {"PNP0C0D", 0},         /* Lid */
 938                 {"PNP0C0E", 0},         /* Sleep button */
 939                 {"", 0},
 940         };
 941         struct acpi_device_wakeup *wakeup = &device->wakeup;
 942         acpi_status status;
 943
 944         wakeup->flags.notifier_present = 0;
 945
 946         /* Power button, Lid switch always enable wakeup */
 947         if (!acpi_match_device_ids(device, button_device_ids)) {
 948                 if (!acpi_match_device_ids(device, &button_device_ids[1])) {
 949                         /* Do not use Lid/sleep button for S5 wakeup */
 950                         if (wakeup->sleep_state == ACPI_STATE_S5)
 951                                 wakeup->sleep_state = ACPI_STATE_S4;
 952                 }
 953                 acpi_mark_gpe_for_wake(wakeup->gpe_device, wakeup->gpe_number);
 954                 device_set_wakeup_capable(&device->dev, true);
 955                 return true;
 956         }
 957
 958         status = acpi_setup_gpe_for_wake(device->handle, wakeup->gpe_device,
 959                                          wakeup->gpe_number);
 960         return ACPI_SUCCESS(status);
 961 }
 962
 963 static void acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
 964 {
 965         int err;
 966
 967         /* Presence of _PRW indicates wake capable */
 968         if (!acpi_has_method(device->handle, "_PRW"))
 969                 return;
 970
 971         err = acpi_bus_extract_wakeup_device_power_package(device);
 972         if (err) {
 973                 dev_err(&device->dev, "Unable to extract wakeup power resources");
 974                 return;
 975         }
 976
 977         device->wakeup.flags.valid = acpi_wakeup_gpe_init(device);
 978         device->wakeup.prepare_count = 0;
 979         /*
 980          * Call _PSW/_DSW object to disable its ability to wake the sleeping
 981          * system for the ACPI device with the _PRW object.
 982          * The _PSW object is deprecated in ACPI 3.0 and is replaced by _DSW.
 983          * So it is necessary to call _DSW object first. Only when it is not
 984          * present will the _PSW object used.
 985          */
 986         err = acpi_device_sleep_wake(device, 0, 0, 0);
 987         if (err)
 988                 pr_debug("error in _DSW or _PSW evaluation\n");
 989 }
 990
 991 static void acpi_bus_init_power_state(struct acpi_device *device, int state)
 992 {
 993         struct acpi_device_power_state *ps = &device->power.states[state];
 994         char pathname[5] = { '_', 'P', 'R', '0' + state, '\0' };
 995         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 996         acpi_status status;
 997
 998         INIT_LIST_HEAD(&ps->resources);
 999
1000         /* Evaluate "_PRx" to get referenced power resources */
1001         status = acpi_evaluate_object(device->handle, pathname, NULL, &buffer);
1002         if (ACPI_SUCCESS(status)) {
1003                 union acpi_object *package = buffer.pointer;
1004
1005                 if (buffer.length && package
1006                     && package->type == ACPI_TYPE_PACKAGE
1007                     && package->package.count)
1008                         acpi_extract_power_resources(package, 0, &ps->resources);
1009
1010                 ACPI_FREE(buffer.pointer);
1011         }
1012
1013         /* Evaluate "_PSx" to see if we can do explicit sets */
1014         pathname[2] = 'S';
1015         if (acpi_has_method(device->handle, pathname))
1016                 ps->flags.explicit_set = 1;
1017
1018         /* State is valid if there are means to put the device into it. */
1019         if (!list_empty(&ps->resources) || ps->flags.explicit_set)
1020                 ps->flags.valid = 1;
1021
1022         ps->power = -1;         /* Unknown - driver assigned */
1023         ps->latency = -1;       /* Unknown - driver assigned */
1024 }
1025
1026 static void acpi_bus_get_power_flags(struct acpi_device *device)
1027 {
1028         unsigned long long dsc = ACPI_STATE_D0;
1029         u32 i;
1030
1031         /* Presence of _PS0|_PR0 indicates 'power manageable' */
1032         if (!acpi_has_method(device->handle, "_PS0") &&
1033             !acpi_has_method(device->handle, "_PR0"))
1034                 return;
1035
1036         device->flags.power_manageable = 1;
1037
1038         /*
1039          * Power Management Flags
1040          */
1041         if (acpi_has_method(device->handle, "_PSC"))
1042                 device->power.flags.explicit_get = 1;
1043
1044         if (acpi_has_method(device->handle, "_IRC"))
1045                 device->power.flags.inrush_current = 1;
1046
1047         if (acpi_has_method(device->handle, "_DSW"))
1048                 device->power.flags.dsw_present = 1;
1049
1050         acpi_evaluate_integer(device->handle, "_DSC", NULL, &dsc);
1051         device->power.state_for_enumeration = dsc;
1052
1053         /*
1054          * Enumerate supported power management states
1055          */
1056         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++)
1057                 acpi_bus_init_power_state(device, i);
1058
1059         INIT_LIST_HEAD(&device->power.states[ACPI_STATE_D3_COLD].resources);
1060
1061         /* Set the defaults for D0 and D3hot (always supported). */
1062         device->power.states[ACPI_STATE_D0].flags.valid = 1;
1063         device->power.states[ACPI_STATE_D0].power = 100;
1064         device->power.states[ACPI_STATE_D3_HOT].flags.valid = 1;
1065
1066         /*
1067          * Use power resources only if the D0 list of them is populated, because
1068          * some platforms may provide _PR3 only to indicate D3cold support and
1069          * in those cases the power resources list returned by it may be bogus.
1070          */
1071         if (!list_empty(&device->power.states[ACPI_STATE_D0].resources)) {
1072                 device->power.flags.power_resources = 1;
1073                 /*
1074                  * D3cold is supported if the D3hot list of power resources is
1075                  * not empty.
1076                  */
1077                 if (!list_empty(&device->power.states[ACPI_STATE_D3_HOT].resources))
1078                         device->power.states[ACPI_STATE_D3_COLD].flags.valid = 1;
1079         }
1080
1081         if (acpi_bus_init_power(device))
1082                 device->flags.power_manageable = 0;
1083 }
1084
1085 static void acpi_bus_get_flags(struct acpi_device *device)
1086 {
1087         /* Presence of _STA indicates 'dynamic_status' */
1088         if (acpi_has_method(device->handle, "_STA"))
1089                 device->flags.dynamic_status = 1;
1090
1091         /* Presence of _RMV indicates 'removable' */
1092         if (acpi_has_method(device->handle, "_RMV"))
1093                 device->flags.removable = 1;
1094
1095         /* Presence of _EJD|_EJ0 indicates 'ejectable' */
1096         if (acpi_has_method(device->handle, "_EJD") ||
1097             acpi_has_method(device->handle, "_EJ0"))
1098                 device->flags.ejectable = 1;
1099 }
1100
1101 static void acpi_device_get_busid(struct acpi_device *device)
1102 {
1103         char bus_id[5] = { '?', 0 };
1104         struct acpi_buffer buffer = { sizeof(bus_id), bus_id };
1105         int i = 0;
1106
1107         /*
1108          * Bus ID
1109          * ------
1110          * The device's Bus ID is simply the object name.
1111          * TBD: Shouldn't this value be unique (within the ACPI namespace)?
1112          */
1113         if (!acpi_dev_parent(device)) {
1114                 strcpy(device->pnp.bus_id, "ACPI");
1115                 return;
1116         }
1117
1118         switch (device->device_type) {
1119         case ACPI_BUS_TYPE_POWER_BUTTON:
1120                 strcpy(device->pnp.bus_id, "PWRF");
1121                 break;
1122         case ACPI_BUS_TYPE_SLEEP_BUTTON:
1123                 strcpy(device->pnp.bus_id, "SLPF");
1124                 break;
1125         case ACPI_BUS_TYPE_ECDT_EC:
1126                 strcpy(device->pnp.bus_id, "ECDT");
1127                 break;
1128         default:
1129                 acpi_get_name(device->handle, ACPI_SINGLE_NAME, &buffer);
1130                 /* Clean up trailing underscores (if any) */
1131                 for (i = 3; i > 1; i--) {
1132                         if (bus_id[i] == '_')
1133                                 bus_id[i] = '\0';
1134                         else
1135                                 break;
1136                 }
1137                 strcpy(device->pnp.bus_id, bus_id);
1138                 break;
1139         }
1140 }
1141
1142 /*
1143  * acpi_ata_match - see if an acpi object is an ATA device
1144  *
1145  * If an acpi object has one of the ACPI ATA methods defined,
1146  * then we can safely call it an ATA device.
1147  */
1148 bool acpi_ata_match(acpi_handle handle)
1149 {
1150         return acpi_has_method(handle, "_GTF") ||
1151                acpi_has_method(handle, "_GTM") ||
1152                acpi_has_method(handle, "_STM") ||
1153                acpi_has_method(handle, "_SDD");
1154 }
1155
1156 /*
1157  * acpi_bay_match - see if an acpi object is an ejectable driver bay
1158  *
1159  * If an acpi object is ejectable and has one of the ACPI ATA methods defined,
1160  * then we can safely call it an ejectable drive bay
1161  */
1162 bool acpi_bay_match(acpi_handle handle)
1163 {
1164         acpi_handle phandle;
1165
1166         if (!acpi_has_method(handle, "_EJ0"))
1167                 return false;
1168         if (acpi_ata_match(handle))
1169                 return true;
1170         if (ACPI_FAILURE(acpi_get_parent(handle, &phandle)))
1171                 return false;
1172
1173         return acpi_ata_match(phandle);
1174 }
1175
1176 bool acpi_device_is_battery(struct acpi_device *adev)
1177 {
1178         struct acpi_hardware_id *hwid;
1179
1180         list_for_each_entry(hwid, &adev->pnp.ids, list)
1181                 if (!strcmp("PNP0C0A", hwid->id))
1182                         return true;
1183
1184         return false;
1185 }
1186
1187 static bool is_ejectable_bay(struct acpi_device *adev)
1188 {
1189         acpi_handle handle = adev->handle;
1190
1191         if (acpi_has_method(handle, "_EJ0") && acpi_device_is_battery(adev))
1192                 return true;
1193
1194         return acpi_bay_match(handle);
1195 }
1196
1197 /*
1198  * acpi_dock_match - see if an acpi object has a _DCK method
1199  */
1200 bool acpi_dock_match(acpi_handle handle)
1201 {
1202         return acpi_has_method(handle, "_DCK");
1203 }
1204
1205 static acpi_status
1206 acpi_backlight_cap_match(acpi_handle handle, u32 level, void *context,
1207                           void **return_value)
1208 {
1209         long *cap = context;
1210
1211         if (acpi_has_method(handle, "_BCM") &&
1212             acpi_has_method(handle, "_BCL")) {
1213                 acpi_handle_debug(handle, "Found generic backlight support\n");
1214                 *cap |= ACPI_VIDEO_BACKLIGHT;
1215                 /* We have backlight support, no need to scan further */
1216                 return AE_CTRL_TERMINATE;
1217         }
1218         return 0;
1219 }
1220
1221 /* Returns true if the ACPI object is a video device which can be
1222  * handled by video.ko.
1223  * The device will get a Linux specific CID added in scan.c to
1224  * identify the device as an ACPI graphics device
1225  * Be aware that the graphics device may not be physically present
1226  * Use acpi_video_get_capabilities() to detect general ACPI video
1227  * capabilities of present cards
1228  */
1229 long acpi_is_video_device(acpi_handle handle)
1230 {
1231         long video_caps = 0;
1232
1233         /* Is this device able to support video switching ? */
1234         if (acpi_has_method(handle, "_DOD") || acpi_has_method(handle, "_DOS"))
1235                 video_caps |= ACPI_VIDEO_OUTPUT_SWITCHING;
1236
1237         /* Is this device able to retrieve a video ROM ? */
1238         if (acpi_has_method(handle, "_ROM"))
1239                 video_caps |= ACPI_VIDEO_ROM_AVAILABLE;
1240
1241         /* Is this device able to configure which video head to be POSTed ? */
1242         if (acpi_has_method(handle, "_VPO") &&
1243             acpi_has_method(handle, "_GPD") &&
1244             acpi_has_method(handle, "_SPD"))
1245                 video_caps |= ACPI_VIDEO_DEVICE_POSTING;
1246
1247         /* Only check for backlight functionality if one of the above hit. */
1248         if (video_caps)
1249                 acpi_walk_namespace(ACPI_TYPE_DEVICE, handle,
1250                                     ACPI_UINT32_MAX, acpi_backlight_cap_match, NULL,
1251                                     &video_caps, NULL);
1252
1253         return video_caps;
1254 }
1255 EXPORT_SYMBOL(acpi_is_video_device);
1256
1257 const char *acpi_device_hid(struct acpi_device *device)
1258 {
1259         struct acpi_hardware_id *hid;
1260
1261         if (list_empty(&device->pnp.ids))
1262                 return dummy_hid;
1263
1264         hid = list_first_entry(&device->pnp.ids, struct acpi_hardware_id, list);
1265         return hid->id;
1266 }
1267 EXPORT_SYMBOL(acpi_device_hid);
1268
1269 static void acpi_add_id(struct acpi_device_pnp *pnp, const char *dev_id)
1270 {
1271         struct acpi_hardware_id *id;
1272
1273         id = kmalloc(sizeof(*id), GFP_KERNEL);
1274         if (!id)
1275                 return;
1276
1277         id->id = kstrdup_const(dev_id, GFP_KERNEL);
1278         if (!id->id) {
1279                 kfree(id);
1280                 return;
1281         }
1282
1283         list_add_tail(&id->list, &pnp->ids);
1284         pnp->type.hardware_id = 1;
1285 }
1286
1287 /*
1288  * Old IBM workstations have a DSDT bug wherein the SMBus object
1289  * lacks the SMBUS01 HID and the methods do not have the necessary "_"
1290  * prefix.  Work around this.
1291  */
1292 static bool acpi_ibm_smbus_match(acpi_handle handle)
1293 {
1294         char node_name[ACPI_PATH_SEGMENT_LENGTH];
1295         struct acpi_buffer path = { sizeof(node_name), node_name };
1296
1297         if (!dmi_name_in_vendors("IBM"))
1298                 return false;
1299
1300         /* Look for SMBS object */
1301         if (ACPI_FAILURE(acpi_get_name(handle, ACPI_SINGLE_NAME, &path)) ||
1302             strcmp("SMBS", path.pointer))
1303                 return false;
1304
1305         /* Does it have the necessary (but misnamed) methods? */
1306         if (acpi_has_method(handle, "SBI") &&
1307             acpi_has_method(handle, "SBR") &&
1308             acpi_has_method(handle, "SBW"))
1309                 return true;
1310
1311         return false;
1312 }
1313
1314 static bool acpi_object_is_system_bus(acpi_handle handle)
1315 {
1316         acpi_handle tmp;
1317
1318         if (ACPI_SUCCESS(acpi_get_handle(NULL, "\\_SB", &tmp)) &&
1319             tmp == handle)
1320                 return true;
1321         if (ACPI_SUCCESS(acpi_get_handle(NULL, "\\_TZ", &tmp)) &&
1322             tmp == handle)
1323                 return true;
1324
1325         return false;
1326 }
1327
1328 static void acpi_set_pnp_ids(acpi_handle handle, struct acpi_device_pnp *pnp,
1329                              int device_type)
1330 {
1331         struct acpi_device_info *info = NULL;
1332         struct acpi_pnp_device_id_list *cid_list;
1333         int i;
1334
1335         switch (device_type) {
1336         case ACPI_BUS_TYPE_DEVICE:
1337                 if (handle == ACPI_ROOT_OBJECT) {
1338                         acpi_add_id(pnp, ACPI_SYSTEM_HID);
1339                         break;
1340                 }
1341
1342                 acpi_get_object_info(handle, &info);
1343                 if (!info) {
1344                         pr_err("%s: Error reading device info\n", __func__);
1345                         return;
1346                 }
1347
1348                 if (info->valid & ACPI_VALID_HID) {
1349                         acpi_add_id(pnp, info->hardware_id.string);
1350                         pnp->type.platform_id = 1;
1351                 }
1352                 if (info->valid & ACPI_VALID_CID) {
1353                         cid_list = &info->compatible_id_list;
1354                         for (i = 0; i < cid_list->count; i++)
1355                                 acpi_add_id(pnp, cid_list->ids[i].string);
1356                 }
1357                 if (info->valid & ACPI_VALID_ADR) {
1358                         pnp->bus_address = info->address;
1359                         pnp->type.bus_address = 1;
1360                 }
1361                 if (info->valid & ACPI_VALID_UID)
1362                         pnp->unique_id = kstrdup(info->unique_id.string,
1363                                                         GFP_KERNEL);
1364                 if (info->valid & ACPI_VALID_CLS)
1365                         acpi_add_id(pnp, info->class_code.string);
1366
1367                 kfree(info);
1368
1369                 /*
1370                  * Some devices don't reliably have _HIDs & _CIDs, so add
1371                  * synthetic HIDs to make sure drivers can find them.
1372                  */
1373                 if (acpi_is_video_device(handle))
1374                         acpi_add_id(pnp, ACPI_VIDEO_HID);
1375                 else if (acpi_bay_match(handle))
1376                         acpi_add_id(pnp, ACPI_BAY_HID);
1377                 else if (acpi_dock_match(handle))
1378                         acpi_add_id(pnp, ACPI_DOCK_HID);
1379                 else if (acpi_ibm_smbus_match(handle))
1380                         acpi_add_id(pnp, ACPI_SMBUS_IBM_HID);
1381                 else if (list_empty(&pnp->ids) &&
1382                          acpi_object_is_system_bus(handle)) {
1383                         /* \_SB, \_TZ, LNXSYBUS */
1384                         acpi_add_id(pnp, ACPI_BUS_HID);
1385                         strcpy(pnp->device_name, ACPI_BUS_DEVICE_NAME);
1386                         strcpy(pnp->device_class, ACPI_BUS_CLASS);
1387                 }
1388
1389                 break;
1390         case ACPI_BUS_TYPE_POWER:
1391                 acpi_add_id(pnp, ACPI_POWER_HID);
1392                 break;
1393         case ACPI_BUS_TYPE_PROCESSOR:
1394                 acpi_add_id(pnp, ACPI_PROCESSOR_OBJECT_HID);
1395                 break;
1396         case ACPI_BUS_TYPE_THERMAL:
1397                 acpi_add_id(pnp, ACPI_THERMAL_HID);
1398                 break;
1399         case ACPI_BUS_TYPE_POWER_BUTTON:
1400                 acpi_add_id(pnp, ACPI_BUTTON_HID_POWERF);
1401                 break;
1402         case ACPI_BUS_TYPE_SLEEP_BUTTON:
1403                 acpi_add_id(pnp, ACPI_BUTTON_HID_SLEEPF);
1404                 break;
1405         case ACPI_BUS_TYPE_ECDT_EC:
1406                 acpi_add_id(pnp, ACPI_ECDT_HID);
1407                 break;
1408         }
1409 }
1410
1411 void acpi_free_pnp_ids(struct acpi_device_pnp *pnp)
1412 {
1413         struct acpi_hardware_id *id, *tmp;
1414
1415         list_for_each_entry_safe(id, tmp, &pnp->ids, list) {
1416                 kfree_const(id->id);
1417                 kfree(id);
1418         }
1419         kfree(pnp->unique_id);
1420 }
1421
1422 /**
1423  * acpi_dma_supported - Check DMA support for the specified device.
1424  * @adev: The pointer to acpi device
1425  *
1426  * Return false if DMA is not supported. Otherwise, return true
1427  */
1428 bool acpi_dma_supported(const struct acpi_device *adev)
1429 {
1430         if (!adev)
1431                 return false;
1432
1433         if (adev->flags.cca_seen)
1434                 return true;
1435
1436         /*
1437         * Per ACPI 6.0 sec 6.2.17, assume devices can do cache-coherent
1438         * DMA on "Intel platforms".  Presumably that includes all x86 and
1439         * ia64, and other arches will set CONFIG_ACPI_CCA_REQUIRED=y.
1440         */
1441         if (!IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED))
1442                 return true;
1443
1444         return false;
1445 }
1446
1447 /**
1448  * acpi_get_dma_attr - Check the supported DMA attr for the specified device.
1449  * @adev: The pointer to acpi device
1450  *
1451  * Return enum dev_dma_attr.
1452  */
1453 enum dev_dma_attr acpi_get_dma_attr(struct acpi_device *adev)
1454 {
1455         if (!acpi_dma_supported(adev))
1456                 return DEV_DMA_NOT_SUPPORTED;
1457
1458         if (adev->flags.coherent_dma)
1459                 return DEV_DMA_COHERENT;
1460         else
1461                 return DEV_DMA_NON_COHERENT;
1462 }
1463
1464 /**
1465  * acpi_dma_get_range() - Get device DMA parameters.
1466  *
1467  * @dev: device to configure
1468  * @map: pointer to DMA ranges result
1469  *
1470  * Evaluate DMA regions and return pointer to DMA regions on
1471  * parsing success; it does not update the passed in values on failure.
1472  *
1473  * Return 0 on success, < 0 on failure.
1474  */
1475 int acpi_dma_get_range(struct device *dev, const struct bus_dma_region **map)
1476 {
1477         struct acpi_device *adev;
1478         LIST_HEAD(list);
1479         struct resource_entry *rentry;
1480         int ret;
1481         struct device *dma_dev = dev;
1482         struct bus_dma_region *r;
1483
1484         /*
1485          * Walk the device tree chasing an ACPI companion with a _DMA
1486          * object while we go. Stop if we find a device with an ACPI
1487          * companion containing a _DMA method.
1488          */
1489         do {
1490                 adev = ACPI_COMPANION(dma_dev);
1491                 if (adev && acpi_has_method(adev->handle, METHOD_NAME__DMA))
1492                         break;
1493
1494                 dma_dev = dma_dev->parent;
1495         } while (dma_dev);
1496
1497         if (!dma_dev)
1498                 return -ENODEV;
1499
1500         if (!acpi_has_method(adev->handle, METHOD_NAME__CRS)) {
1501                 acpi_handle_warn(adev->handle, "_DMA is valid only if _CRS is present\n");
1502                 return -EINVAL;
1503         }
1504
1505         ret = acpi_dev_get_dma_resources(adev, &list);
1506         if (ret > 0) {
1507                 r = kcalloc(ret + 1, sizeof(*r), GFP_KERNEL);
1508                 if (!r) {
1509                         ret = -ENOMEM;
1510                         goto out;
1511                 }
1512
1513                 *map = r;
1514
1515                 list_for_each_entry(rentry, &list, node) {
1516                         if (rentry->res->start >= rentry->res->end) {
1517                                 kfree(*map);
1518                                 *map = NULL;
1519                                 ret = -EINVAL;
1520                                 dev_dbg(dma_dev, "Invalid DMA regions configuration\n");
1521                                 goto out;
1522                         }
1523
1524                         r->cpu_start = rentry->res->start;
1525                         r->dma_start = rentry->res->start - rentry->offset;
1526                         r->size = resource_size(rentry->res);
1527                         r->offset = rentry->offset;
1528                         r++;
1529                 }
1530         }
1531  out:
1532         acpi_dev_free_resource_list(&list);
1533
1534         return ret >= 0 ? 0 : ret;
1535 }
1536
1537 #ifdef CONFIG_IOMMU_API
1538 int acpi_iommu_fwspec_init(struct device *dev, u32 id,
1539                            struct fwnode_handle *fwnode,
1540                            const struct iommu_ops *ops)
1541 {
1542         int ret = iommu_fwspec_init(dev, fwnode, ops);
1543
1544         if (!ret)
1545                 ret = iommu_fwspec_add_ids(dev, &id, 1);
1546
1547         return ret;
1548 }
1549
1550 static inline const struct iommu_ops *acpi_iommu_fwspec_ops(struct device *dev)
1551 {
1552         struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
1553
1554         return fwspec ? fwspec->ops : NULL;
1555 }
1556
1557 static const struct iommu_ops *acpi_iommu_configure_id(struct device *dev,
1558                                                        const u32 *id_in)
1559 {
1560         int err;
1561         const struct iommu_ops *ops;
1562
1563         /*
1564          * If we already translated the fwspec there is nothing left to do,
1565          * return the iommu_ops.
1566          */
1567         ops = acpi_iommu_fwspec_ops(dev);
1568         if (ops)
1569                 return ops;
1570
1571         err = iort_iommu_configure_id(dev, id_in);
1572         if (err && err != -EPROBE_DEFER)
1573                 err = viot_iommu_configure(dev);
1574
1575         /*
1576          * If we have reason to believe the IOMMU driver missed the initial
1577          * iommu_probe_device() call for dev, replay it to get things in order.
1578          */
1579         if (!err && dev->bus && !device_iommu_mapped(dev))
1580                 err = iommu_probe_device(dev);
1581
1582         /* Ignore all other errors apart from EPROBE_DEFER */
1583         if (err == -EPROBE_DEFER) {
1584                 return ERR_PTR(err);
1585         } else if (err) {
1586                 dev_dbg(dev, "Adding to IOMMU failed: %d\n", err);
1587                 return NULL;
1588         }
1589         return acpi_iommu_fwspec_ops(dev);
1590 }
1591
1592 #else /* !CONFIG_IOMMU_API */
1593
1594 int acpi_iommu_fwspec_init(struct device *dev, u32 id,
1595                            struct fwnode_handle *fwnode,
1596                            const struct iommu_ops *ops)
1597 {
1598         return -ENODEV;
1599 }
1600
1601 static const struct iommu_ops *acpi_iommu_configure_id(struct device *dev,
1602                                                        const u32 *id_in)
1603 {
1604         return NULL;
1605 }
1606
1607 #endif /* !CONFIG_IOMMU_API */
1608
1609 /**
1610  * acpi_dma_configure_id - Set-up DMA configuration for the device.
1611  * @dev: The pointer to the device
1612  * @attr: device dma attributes
1613  * @input_id: input device id const value pointer
1614  */
1615 int acpi_dma_configure_id(struct device *dev, enum dev_dma_attr attr,
1616                           const u32 *input_id)
1617 {
1618         const struct iommu_ops *iommu;
1619
1620         if (attr == DEV_DMA_NOT_SUPPORTED) {
1621                 set_dma_ops(dev, &dma_dummy_ops);
1622                 return 0;
1623         }
1624
1625         acpi_arch_dma_setup(dev);
1626
1627         iommu = acpi_iommu_configure_id(dev, input_id);
1628         if (PTR_ERR(iommu) == -EPROBE_DEFER)
1629                 return -EPROBE_DEFER;
1630
1631         arch_setup_dma_ops(dev, 0, U64_MAX,
1632                                 iommu, attr == DEV_DMA_COHERENT);
1633
1634         return 0;
1635 }
1636 EXPORT_SYMBOL_GPL(acpi_dma_configure_id);
1637
1638 static void acpi_init_coherency(struct acpi_device *adev)
1639 {
1640         unsigned long long cca = 0;
1641         acpi_status status;
1642         struct acpi_device *parent = acpi_dev_parent(adev);
1643
1644         if (parent && parent->flags.cca_seen) {
1645                 /*
1646                  * From ACPI spec, OSPM will ignore _CCA if an ancestor
1647                  * already saw one.
1648                  */
1649                 adev->flags.cca_seen = 1;
1650                 cca = parent->flags.coherent_dma;
1651         } else {
1652                 status = acpi_evaluate_integer(adev->handle, "_CCA",
1653                                                NULL, &cca);
1654                 if (ACPI_SUCCESS(status))
1655                         adev->flags.cca_seen = 1;
1656                 else if (!IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED))
1657                         /*
1658                          * If architecture does not specify that _CCA is
1659                          * required for DMA-able devices (e.g. x86),
1660                          * we default to _CCA=1.
1661                          */
1662                         cca = 1;
1663                 else
1664                         acpi_handle_debug(adev->handle,
1665                                           "ACPI device is missing _CCA.\n");
1666         }
1667
1668         adev->flags.coherent_dma = cca;
1669 }
1670
1671 static int acpi_check_serial_bus_slave(struct acpi_resource *ares, void *data)
1672 {
1673         bool *is_serial_bus_slave_p = data;
1674
1675         if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
1676                 return 1;
1677
1678         *is_serial_bus_slave_p = true;
1679
1680          /* no need to do more checking */
1681         return -1;
1682 }
1683
1684 static bool acpi_is_indirect_io_slave(struct acpi_device *device)
1685 {
1686         struct acpi_device *parent = acpi_dev_parent(device);
1687         static const struct acpi_device_id indirect_io_hosts[] = {
1688                 {"HISI0191", 0},
1689                 {}
1690         };
1691
1692         return parent && !acpi_match_device_ids(parent, indirect_io_hosts);
1693 }
1694
1695 static bool acpi_device_enumeration_by_parent(struct acpi_device *device)
1696 {
1697         struct list_head resource_list;
1698         bool is_serial_bus_slave = false;
1699         static const struct acpi_device_id ignore_serial_bus_ids[] = {
1700         /*
1701          * These devices have multiple SerialBus resources and a client
1702          * device must be instantiated for each of them, each with
1703          * its own device id.
1704          * Normally we only instantiate one client device for the first
1705          * resource, using the ACPI HID as id. These special cases are handled
1706          * by the drivers/platform/x86/serial-multi-instantiate.c driver, which
1707          * knows which client device id to use for each resource.
1708          */
1709                 {"BSG1160", },
1710                 {"BSG2150", },
1711                 {"CSC3551", },
1712                 {"INT33FE", },
1713                 {"INT3515", },
1714                 /* Non-conforming _HID for Cirrus Logic already released */
1715                 {"CLSA0100", },
1716                 {"CLSA0101", },
1717         /*
1718          * Some ACPI devs contain SerialBus resources even though they are not
1719          * attached to a serial bus at all.
1720          */
1721                 {"MSHW0028", },
1722         /*
1723          * HIDs of device with an UartSerialBusV2 resource for which userspace
1724          * expects a regular tty cdev to be created (instead of the in kernel
1725          * serdev) and which have a kernel driver which expects a platform_dev
1726          * such as the rfkill-gpio driver.
1727          */
1728                 {"BCM4752", },
1729                 {"LNV4752", },
1730                 {}
1731         };
1732
1733         if (acpi_is_indirect_io_slave(device))
1734                 return true;
1735
1736         /* Macs use device properties in lieu of _CRS resources */
1737         if (x86_apple_machine &&
1738             (fwnode_property_present(&device->fwnode, "spiSclkPeriod") ||
1739              fwnode_property_present(&device->fwnode, "i2cAddress") ||
1740              fwnode_property_present(&device->fwnode, "baud")))
1741                 return true;
1742
1743         if (!acpi_match_device_ids(device, ignore_serial_bus_ids))
1744                 return false;
1745
1746         INIT_LIST_HEAD(&resource_list);
1747         acpi_dev_get_resources(device, &resource_list,
1748                                acpi_check_serial_bus_slave,
1749                                &is_serial_bus_slave);
1750         acpi_dev_free_resource_list(&resource_list);
1751
1752         return is_serial_bus_slave;
1753 }
1754
1755 void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,
1756                              int type, void (*release)(struct device *))
1757 {
1758         struct acpi_device *parent = acpi_find_parent_acpi_dev(handle);
1759
1760         INIT_LIST_HEAD(&device->pnp.ids);
1761         device->device_type = type;
1762         device->handle = handle;
1763         device->dev.parent = parent ? &parent->dev : NULL;
1764         device->dev.release = release;
1765         device->dev.bus = &acpi_bus_type;
1766         fwnode_init(&device->fwnode, &acpi_device_fwnode_ops);
1767         acpi_set_device_status(device, ACPI_STA_DEFAULT);
1768         acpi_device_get_busid(device);
1769         acpi_set_pnp_ids(handle, &device->pnp, type);
1770         acpi_init_properties(device);
1771         acpi_bus_get_flags(device);
1772         device->flags.match_driver = false;
1773         device->flags.initialized = true;
1774         device->flags.enumeration_by_parent =
1775                 acpi_device_enumeration_by_parent(device);
1776         acpi_device_clear_enumerated(device);
1777         device_initialize(&device->dev);
1778         dev_set_uevent_suppress(&device->dev, true);
1779         acpi_init_coherency(device);
1780 }
1781
1782 static void acpi_scan_dep_init(struct acpi_device *adev)
1783 {
1784         struct acpi_dep_data *dep;
1785
1786         list_for_each_entry(dep, &acpi_dep_list, node) {
1787                 if (dep->consumer == adev->handle) {
1788                         if (dep->honor_dep)
1789                                 adev->flags.honor_deps = 1;
1790
1791                         adev->dep_unmet++;
1792                 }
1793         }
1794 }
1795
1796 void acpi_device_add_finalize(struct acpi_device *device)
1797 {
1798         dev_set_uevent_suppress(&device->dev, false);
1799         kobject_uevent(&device->dev.kobj, KOBJ_ADD);
1800 }
1801
1802 static void acpi_scan_init_status(struct acpi_device *adev)
1803 {
1804         if (acpi_bus_get_status(adev))
1805                 acpi_set_device_status(adev, 0);
1806 }
1807
1808 static int acpi_add_single_object(struct acpi_device **child,
1809                                   acpi_handle handle, int type, bool dep_init)
1810 {
1811         struct acpi_device *device;
1812         bool release_dep_lock = false;
1813         int result;
1814
1815         device = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
1816         if (!device)
1817                 return -ENOMEM;
1818
1819         acpi_init_device_object(device, handle, type, acpi_device_release);
1820         /*
1821          * Getting the status is delayed till here so that we can call
1822          * acpi_bus_get_status() and use its quirk handling.  Note that
1823          * this must be done before the get power-/wakeup_dev-flags calls.
1824          */
1825         if (type == ACPI_BUS_TYPE_DEVICE || type == ACPI_BUS_TYPE_PROCESSOR) {
1826                 if (dep_init) {
1827                         mutex_lock(&acpi_dep_list_lock);
1828                         /*
1829                          * Hold the lock until the acpi_tie_acpi_dev() call
1830                          * below to prevent concurrent acpi_scan_clear_dep()
1831                          * from deleting a dependency list entry without
1832                          * updating dep_unmet for the device.
1833                          */
1834                         release_dep_lock = true;
1835                         acpi_scan_dep_init(device);
1836                 }
1837                 acpi_scan_init_status(device);
1838         }
1839
1840         acpi_bus_get_power_flags(device);
1841         acpi_bus_get_wakeup_device_flags(device);
1842
1843         result = acpi_tie_acpi_dev(device);
1844
1845         if (release_dep_lock)
1846                 mutex_unlock(&acpi_dep_list_lock);
1847
1848         if (!result)
1849                 result = acpi_device_add(device);
1850
1851         if (result) {
1852                 acpi_device_release(&device->dev);
1853                 return result;
1854         }
1855
1856         acpi_power_add_remove_device(device, true);
1857         acpi_device_add_finalize(device);
1858
1859         acpi_handle_debug(handle, "Added as %s, parent %s\n",
1860                           dev_name(&device->dev), device->dev.parent ?
1861                                 dev_name(device->dev.parent) : "(null)");
1862
1863         *child = device;
1864         return 0;
1865 }
1866
1867 static acpi_status acpi_get_resource_memory(struct acpi_resource *ares,
1868                                             void *context)
1869 {
1870         struct resource *res = context;
1871
1872         if (acpi_dev_resource_memory(ares, res))
1873                 return AE_CTRL_TERMINATE;
1874
1875         return AE_OK;
1876 }
1877
1878 static bool acpi_device_should_be_hidden(acpi_handle handle)
1879 {
1880         acpi_status status;
1881         struct resource res;
1882
1883         /* Check if it should ignore the UART device */
1884         if (!(spcr_uart_addr && acpi_has_method(handle, METHOD_NAME__CRS)))
1885                 return false;
1886
1887         /*
1888          * The UART device described in SPCR table is assumed to have only one
1889          * memory resource present. So we only look for the first one here.
1890          */
1891         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1892                                      acpi_get_resource_memory, &res);
1893         if (ACPI_FAILURE(status) || res.start != spcr_uart_addr)
1894                 return false;
1895
1896         acpi_handle_info(handle, "The UART device @%pa in SPCR table will be hidden\n",
1897                          &res.start);
1898
1899         return true;
1900 }
1901
1902 bool acpi_device_is_present(const struct acpi_device *adev)
1903 {
1904         return adev->status.present || adev->status.functional;
1905 }
1906
1907 static bool acpi_scan_handler_matching(struct acpi_scan_handler *handler,
1908                                        const char *idstr,
1909                                        const struct acpi_device_id **matchid)
1910 {
1911         const struct acpi_device_id *devid;
1912
1913         if (handler->match)
1914                 return handler->match(idstr, matchid);
1915
1916         for (devid = handler->ids; devid->id[0]; devid++)
1917                 if (!strcmp((char *)devid->id, idstr)) {
1918                         if (matchid)
1919                                 *matchid = devid;
1920
1921                         return true;
1922                 }
1923
1924         return false;
1925 }
1926
1927 static struct acpi_scan_handler *acpi_scan_match_handler(const char *idstr,
1928                                         const struct acpi_device_id **matchid)
1929 {
1930         struct acpi_scan_handler *handler;
1931
1932         list_for_each_entry(handler, &acpi_scan_handlers_list, list_node)
1933                 if (acpi_scan_handler_matching(handler, idstr, matchid))
1934                         return handler;
1935
1936         return NULL;
1937 }
1938
1939 void acpi_scan_hotplug_enabled(struct acpi_hotplug_profile *hotplug, bool val)
1940 {
1941         if (!!hotplug->enabled == !!val)
1942                 return;
1943
1944         mutex_lock(&acpi_scan_lock);
1945
1946         hotplug->enabled = val;
1947
1948         mutex_unlock(&acpi_scan_lock);
1949 }
1950
1951 static void acpi_scan_init_hotplug(struct acpi_device *adev)
1952 {
1953         struct acpi_hardware_id *hwid;
1954
1955         if (acpi_dock_match(adev->handle) || is_ejectable_bay(adev)) {
1956                 acpi_dock_add(adev);
1957                 return;
1958         }
1959         list_for_each_entry(hwid, &adev->pnp.ids, list) {
1960                 struct acpi_scan_handler *handler;
1961
1962                 handler = acpi_scan_match_handler(hwid->id, NULL);
1963                 if (handler) {
1964                         adev->flags.hotplug_notify = true;
1965                         break;
1966                 }
1967         }
1968 }
1969
1970 static u32 acpi_scan_check_dep(acpi_handle handle, bool check_dep)
1971 {
1972         struct acpi_handle_list dep_devices;
1973         acpi_status status;
1974         u32 count;
1975         int i;
1976
1977         /*
1978          * Check for _HID here to avoid deferring the enumeration of:
1979          * 1. PCI devices.
1980          * 2. ACPI nodes describing USB ports.
1981          * Still, checking for _HID catches more then just these cases ...
1982          */
1983         if (!check_dep || !acpi_has_method(handle, "_DEP") ||
1984             !acpi_has_method(handle, "_HID"))
1985                 return 0;
1986
1987         status = acpi_evaluate_reference(handle, "_DEP", NULL, &dep_devices);
1988         if (ACPI_FAILURE(status)) {
1989                 acpi_handle_debug(handle, "Failed to evaluate _DEP.\n");
1990                 return 0;
1991         }
1992
1993         for (count = 0, i = 0; i < dep_devices.count; i++) {
1994                 struct acpi_device_info *info;
1995                 struct acpi_dep_data *dep;
1996                 bool skip, honor_dep;
1997
1998                 status = acpi_get_object_info(dep_devices.handles[i], &info);
1999                 if (ACPI_FAILURE(status)) {
2000                         acpi_handle_debug(handle, "Error reading _DEP device info\n");
2001                         continue;
2002                 }
2003
2004                 skip = acpi_info_matches_ids(info, acpi_ignore_dep_ids);
2005                 honor_dep = acpi_info_matches_ids(info, acpi_honor_dep_ids);
2006                 kfree(info);
2007
2008                 if (skip)
2009                         continue;
2010
2011                 dep = kzalloc(sizeof(*dep), GFP_KERNEL);
2012                 if (!dep)
2013                         continue;
2014
2015                 count++;
2016
2017                 dep->supplier = dep_devices.handles[i];
2018                 dep->consumer = handle;
2019                 dep->honor_dep = honor_dep;
2020
2021                 mutex_lock(&acpi_dep_list_lock);
2022                 list_add_tail(&dep->node , &acpi_dep_list);
2023                 mutex_unlock(&acpi_dep_list_lock);
2024         }
2025
2026         return count;
2027 }
2028
2029 static bool acpi_bus_scan_second_pass;
2030
2031 static acpi_status acpi_bus_check_add(acpi_handle handle, bool check_dep,
2032                                       struct acpi_device **adev_p)
2033 {
2034         struct acpi_device *device = acpi_fetch_acpi_dev(handle);
2035         acpi_object_type acpi_type;
2036         int type;
2037
2038         if (device)
2039                 goto out;
2040
2041         if (ACPI_FAILURE(acpi_get_type(handle, &acpi_type)))
2042                 return AE_OK;
2043
2044         switch (acpi_type) {
2045         case ACPI_TYPE_DEVICE:
2046                 if (acpi_device_should_be_hidden(handle))
2047                         return AE_OK;
2048
2049                 /* Bail out if there are dependencies. */
2050                 if (acpi_scan_check_dep(handle, check_dep) > 0) {
2051                         acpi_bus_scan_second_pass = true;
2052                         return AE_CTRL_DEPTH;
2053                 }
2054
2055                 fallthrough;
2056         case ACPI_TYPE_ANY:     /* for ACPI_ROOT_OBJECT */
2057                 type = ACPI_BUS_TYPE_DEVICE;
2058                 break;
2059
2060         case ACPI_TYPE_PROCESSOR:
2061                 type = ACPI_BUS_TYPE_PROCESSOR;
2062                 break;
2063
2064         case ACPI_TYPE_THERMAL:
2065                 type = ACPI_BUS_TYPE_THERMAL;
2066                 break;
2067
2068         case ACPI_TYPE_POWER:
2069                 acpi_add_power_resource(handle);
2070                 fallthrough;
2071         default:
2072                 return AE_OK;
2073         }
2074
2075         /*
2076          * If check_dep is true at this point, the device has no dependencies,
2077          * or the creation of the device object would have been postponed above.
2078          */
2079         acpi_add_single_object(&device, handle, type, !check_dep);
2080         if (!device)
2081                 return AE_CTRL_DEPTH;
2082
2083         acpi_scan_init_hotplug(device);
2084
2085 out:
2086         if (!*adev_p)
2087                 *adev_p = device;
2088
2089         return AE_OK;
2090 }
2091
2092 static acpi_status acpi_bus_check_add_1(acpi_handle handle, u32 lvl_not_used,
2093                                         void *not_used, void **ret_p)
2094 {
2095         return acpi_bus_check_add(handle, true, (struct acpi_device **)ret_p);
2096 }
2097
2098 static acpi_status acpi_bus_check_add_2(acpi_handle handle, u32 lvl_not_used,
2099                                         void *not_used, void **ret_p)
2100 {
2101         return acpi_bus_check_add(handle, false, (struct acpi_device **)ret_p);
2102 }
2103
2104 static void acpi_default_enumeration(struct acpi_device *device)
2105 {
2106         /*
2107          * Do not enumerate devices with enumeration_by_parent flag set as
2108          * they will be enumerated by their respective parents.
2109          */
2110         if (!device->flags.enumeration_by_parent) {
2111                 acpi_create_platform_device(device, NULL);
2112                 acpi_device_set_enumerated(device);
2113         } else {
2114                 blocking_notifier_call_chain(&acpi_reconfig_chain,
2115                                              ACPI_RECONFIG_DEVICE_ADD, device);
2116         }
2117 }
2118
2119 static const struct acpi_device_id generic_device_ids[] = {
2120         {ACPI_DT_NAMESPACE_HID, },
2121         {"", },
2122 };
2123
2124 static int acpi_generic_device_attach(struct acpi_device *adev,
2125                                       const struct acpi_device_id *not_used)
2126 {
2127         /*
2128          * Since ACPI_DT_NAMESPACE_HID is the only ID handled here, the test
2129          * below can be unconditional.
2130          */
2131         if (adev->data.of_compatible)
2132                 acpi_default_enumeration(adev);
2133
2134         return 1;
2135 }
2136
2137 static struct acpi_scan_handler generic_device_handler = {
2138         .ids = generic_device_ids,
2139         .attach = acpi_generic_device_attach,
2140 };
2141
2142 static int acpi_scan_attach_handler(struct acpi_device *device)
2143 {
2144         struct acpi_hardware_id *hwid;
2145         int ret = 0;
2146
2147         list_for_each_entry(hwid, &device->pnp.ids, list) {
2148                 const struct acpi_device_id *devid;
2149                 struct acpi_scan_handler *handler;
2150
2151                 handler = acpi_scan_match_handler(hwid->id, &devid);
2152                 if (handler) {
2153                         if (!handler->attach) {
2154                                 device->pnp.type.platform_id = 0;
2155                                 continue;
2156                         }
2157                         device->handler = handler;
2158                         ret = handler->attach(device, devid);
2159                         if (ret > 0)
2160                                 break;
2161
2162                         device->handler = NULL;
2163                         if (ret < 0)
2164                                 break;
2165                 }
2166         }
2167
2168         return ret;
2169 }
2170
2171 static int acpi_bus_attach(struct acpi_device *device, void *first_pass)
2172 {
2173         bool skip = !first_pass && device->flags.visited;
2174         acpi_handle ejd;
2175         int ret;
2176
2177         if (skip)
2178                 goto ok;
2179
2180         if (ACPI_SUCCESS(acpi_bus_get_ejd(device->handle, &ejd)))
2181                 register_dock_dependent_device(device, ejd);
2182
2183         acpi_bus_get_status(device);
2184         /* Skip devices that are not ready for enumeration (e.g. not present) */
2185         if (!acpi_dev_ready_for_enumeration(device)) {
2186                 device->flags.initialized = false;
2187                 acpi_device_clear_enumerated(device);
2188                 device->flags.power_manageable = 0;
2189                 return 0;
2190         }
2191         if (device->handler)
2192                 goto ok;
2193
2194         if (!device->flags.initialized) {
2195                 device->flags.power_manageable =
2196                         device->power.states[ACPI_STATE_D0].flags.valid;
2197                 if (acpi_bus_init_power(device))
2198                         device->flags.power_manageable = 0;
2199
2200                 device->flags.initialized = true;
2201         } else if (device->flags.visited) {
2202                 goto ok;
2203         }
2204
2205         ret = acpi_scan_attach_handler(device);
2206         if (ret < 0)
2207                 return 0;
2208
2209         device->flags.match_driver = true;
2210         if (ret > 0 && !device->flags.enumeration_by_parent) {
2211                 acpi_device_set_enumerated(device);
2212                 goto ok;
2213         }
2214
2215         ret = device_attach(&device->dev);
2216         if (ret < 0)
2217                 return 0;
2218
2219         if (device->pnp.type.platform_id || device->flags.enumeration_by_parent)
2220                 acpi_default_enumeration(device);
2221         else
2222                 acpi_device_set_enumerated(device);
2223
2224 ok:
2225         acpi_dev_for_each_child(device, acpi_bus_attach, first_pass);
2226
2227         if (!skip && device->handler && device->handler->hotplug.notify_online)
2228                 device->handler->hotplug.notify_online(device);
2229
2230         return 0;
2231 }
2232
2233 static int acpi_dev_get_next_consumer_dev_cb(struct acpi_dep_data *dep, void *data)
2234 {
2235         struct acpi_device **adev_p = data;
2236         struct acpi_device *adev = *adev_p;
2237
2238         /*
2239          * If we're passed a 'previous' consumer device then we need to skip
2240          * any consumers until we meet the previous one, and then NULL @data
2241          * so the next one can be returned.
2242          */
2243         if (adev) {
2244                 if (dep->consumer == adev->handle)
2245                         *adev_p = NULL;
2246
2247                 return 0;
2248         }
2249
2250         adev = acpi_get_acpi_dev(dep->consumer);
2251         if (adev) {
2252                 *(struct acpi_device **)data = adev;
2253                 return 1;
2254         }
2255         /* Continue parsing if the device object is not present. */
2256         return 0;
2257 }
2258
2259 struct acpi_scan_clear_dep_work {
2260         struct work_struct work;
2261         struct acpi_device *adev;
2262 };
2263
2264 static void acpi_scan_clear_dep_fn(struct work_struct *work)
2265 {
2266         struct acpi_scan_clear_dep_work *cdw;
2267
2268         cdw = container_of(work, struct acpi_scan_clear_dep_work, work);
2269
2270         acpi_scan_lock_acquire();
2271         acpi_bus_attach(cdw->adev, (void *)true);
2272         acpi_scan_lock_release();
2273
2274         acpi_dev_put(cdw->adev);
2275         kfree(cdw);
2276 }
2277
2278 static bool acpi_scan_clear_dep_queue(struct acpi_device *adev)
2279 {
2280         struct acpi_scan_clear_dep_work *cdw;
2281
2282         if (adev->dep_unmet)
2283                 return false;
2284
2285         cdw = kmalloc(sizeof(*cdw), GFP_KERNEL);
2286         if (!cdw)
2287                 return false;
2288
2289         cdw->adev = adev;
2290         INIT_WORK(&cdw->work, acpi_scan_clear_dep_fn);
2291         /*
2292          * Since the work function may block on the lock until the entire
2293          * initial enumeration of devices is complete, put it into the unbound
2294          * workqueue.
2295          */
2296         queue_work(system_unbound_wq, &cdw->work);
2297
2298         return true;
2299 }
2300
2301 static int acpi_scan_clear_dep(struct acpi_dep_data *dep, void *data)
2302 {
2303         struct acpi_device *adev = acpi_get_acpi_dev(dep->consumer);
2304
2305         if (adev) {
2306                 adev->dep_unmet--;
2307                 if (!acpi_scan_clear_dep_queue(adev))
2308                         acpi_dev_put(adev);
2309         }
2310
2311         list_del(&dep->node);
2312         kfree(dep);
2313
2314         return 0;
2315 }
2316
2317 /**
2318  * acpi_walk_dep_device_list - Apply a callback to every entry in acpi_dep_list
2319  * @handle:     The ACPI handle of the supplier device
2320  * @callback:   Pointer to the callback function to apply
2321  * @data:       Pointer to some data to pass to the callback
2322  *
2323  * The return value of the callback determines this function's behaviour. If 0
2324  * is returned we continue to iterate over acpi_dep_list. If a positive value
2325  * is returned then the loop is broken but this function returns 0. If a
2326  * negative value is returned by the callback then the loop is broken and that
2327  * value is returned as the final error.
2328  */
2329 static int acpi_walk_dep_device_list(acpi_handle handle,
2330                                 int (*callback)(struct acpi_dep_data *, void *),
2331                                 void *data)
2332 {
2333         struct acpi_dep_data *dep, *tmp;
2334         int ret = 0;
2335
2336         mutex_lock(&acpi_dep_list_lock);
2337         list_for_each_entry_safe(dep, tmp, &acpi_dep_list, node) {
2338                 if (dep->supplier == handle) {
2339                         ret = callback(dep, data);
2340                         if (ret)
2341                                 break;
2342                 }
2343         }
2344         mutex_unlock(&acpi_dep_list_lock);
2345
2346         return ret > 0 ? 0 : ret;
2347 }
2348
2349 /**
2350  * acpi_dev_clear_dependencies - Inform consumers that the device is now active
2351  * @supplier: Pointer to the supplier &struct acpi_device
2352  *
2353  * Clear dependencies on the given device.
2354  */
2355 void acpi_dev_clear_dependencies(struct acpi_device *supplier)
2356 {
2357         acpi_walk_dep_device_list(supplier->handle, acpi_scan_clear_dep, NULL);
2358 }
2359 EXPORT_SYMBOL_GPL(acpi_dev_clear_dependencies);
2360
2361 /**
2362  * acpi_dev_ready_for_enumeration - Check if the ACPI device is ready for enumeration
2363  * @device: Pointer to the &struct acpi_device to check
2364  *
2365  * Check if the device is present and has no unmet dependencies.
2366  *
2367  * Return true if the device is ready for enumeratino. Otherwise, return false.
2368  */
2369 bool acpi_dev_ready_for_enumeration(const struct acpi_device *device)
2370 {
2371         if (device->flags.honor_deps && device->dep_unmet)
2372                 return false;
2373
2374         return acpi_device_is_present(device);
2375 }
2376 EXPORT_SYMBOL_GPL(acpi_dev_ready_for_enumeration);
2377
2378 /**
2379  * acpi_dev_get_next_consumer_dev - Return the next adev dependent on @supplier
2380  * @supplier: Pointer to the dependee device
2381  * @start: Pointer to the current dependent device
2382  *
2383  * Returns the next &struct acpi_device which declares itself dependent on
2384  * @supplier via the _DEP buffer, parsed from the acpi_dep_list.
2385  *
2386  * If the returned adev is not passed as @start to this function, the caller is
2387  * responsible for putting the reference to adev when it is no longer needed.
2388  */
2389 struct acpi_device *acpi_dev_get_next_consumer_dev(struct acpi_device *supplier,
2390                                                    struct acpi_device *start)
2391 {
2392         struct acpi_device *adev = start;
2393
2394         acpi_walk_dep_device_list(supplier->handle,
2395                                   acpi_dev_get_next_consumer_dev_cb, &adev);
2396
2397         acpi_dev_put(start);
2398
2399         if (adev == start)
2400                 return NULL;
2401
2402         return adev;
2403 }
2404 EXPORT_SYMBOL_GPL(acpi_dev_get_next_consumer_dev);
2405
2406 /**
2407  * acpi_bus_scan - Add ACPI device node objects in a given namespace scope.
2408  * @handle: Root of the namespace scope to scan.
2409  *
2410  * Scan a given ACPI tree (probably recently hot-plugged) and create and add
2411  * found devices.
2412  *
2413  * If no devices were found, -ENODEV is returned, but it does not mean that
2414  * there has been a real error.  There just have been no suitable ACPI objects
2415  * in the table trunk from which the kernel could create a device and add an
2416  * appropriate driver.
2417  *
2418  * Must be called under acpi_scan_lock.
2419  */
2420 int acpi_bus_scan(acpi_handle handle)
2421 {
2422         struct acpi_device *device = NULL;
2423
2424         acpi_bus_scan_second_pass = false;
2425
2426         /* Pass 1: Avoid enumerating devices with missing dependencies. */
2427
2428         if (ACPI_SUCCESS(acpi_bus_check_add(handle, true, &device)))
2429                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
2430                                     acpi_bus_check_add_1, NULL, NULL,
2431                                     (void **)&device);
2432
2433         if (!device)
2434                 return -ENODEV;
2435
2436         acpi_bus_attach(device, (void *)true);
2437
2438         if (!acpi_bus_scan_second_pass)
2439                 return 0;
2440
2441         /* Pass 2: Enumerate all of the remaining devices. */
2442
2443         device = NULL;
2444
2445         if (ACPI_SUCCESS(acpi_bus_check_add(handle, false, &device)))
2446                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
2447                                     acpi_bus_check_add_2, NULL, NULL,
2448                                     (void **)&device);
2449
2450         acpi_bus_attach(device, NULL);
2451
2452         return 0;
2453 }
2454 EXPORT_SYMBOL(acpi_bus_scan);
2455
2456 static int acpi_bus_trim_one(struct acpi_device *adev, void *not_used)
2457 {
2458         struct acpi_scan_handler *handler = adev->handler;
2459
2460         acpi_dev_for_each_child_reverse(adev, acpi_bus_trim_one, NULL);
2461
2462         adev->flags.match_driver = false;
2463         if (handler) {
2464                 if (handler->detach)
2465                         handler->detach(adev);
2466
2467                 adev->handler = NULL;
2468         } else {
2469                 device_release_driver(&adev->dev);
2470         }
2471         /*
2472          * Most likely, the device is going away, so put it into D3cold before
2473          * that.
2474          */
2475         acpi_device_set_power(adev, ACPI_STATE_D3_COLD);
2476         adev->flags.initialized = false;
2477         acpi_device_clear_enumerated(adev);
2478
2479         return 0;
2480 }
2481
2482 /**
2483  * acpi_bus_trim - Detach scan handlers and drivers from ACPI device objects.
2484  * @adev: Root of the ACPI namespace scope to walk.
2485  *
2486  * Must be called under acpi_scan_lock.
2487  */
2488 void acpi_bus_trim(struct acpi_device *adev)
2489 {
2490         acpi_bus_trim_one(adev, NULL);
2491 }
2492 EXPORT_SYMBOL_GPL(acpi_bus_trim);
2493
2494 int acpi_bus_register_early_device(int type)
2495 {
2496         struct acpi_device *device = NULL;
2497         int result;
2498
2499         result = acpi_add_single_object(&device, NULL, type, false);
2500         if (result)
2501                 return result;
2502
2503         device->flags.match_driver = true;
2504         return device_attach(&device->dev);
2505 }
2506 EXPORT_SYMBOL_GPL(acpi_bus_register_early_device);
2507
2508 static void acpi_bus_scan_fixed(void)
2509 {
2510         if (!(acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON)) {
2511                 struct acpi_device *adev = NULL;
2512
2513                 acpi_add_single_object(&adev, NULL, ACPI_BUS_TYPE_POWER_BUTTON,
2514                                        false);
2515                 if (adev) {
2516                         adev->flags.match_driver = true;
2517                         if (device_attach(&adev->dev) >= 0)
2518                                 device_init_wakeup(&adev->dev, true);
2519                         else
2520                                 dev_dbg(&adev->dev, "No driver\n");
2521                 }
2522         }
2523
2524         if (!(acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON)) {
2525                 struct acpi_device *adev = NULL;
2526
2527                 acpi_add_single_object(&adev, NULL, ACPI_BUS_TYPE_SLEEP_BUTTON,
2528                                        false);
2529                 if (adev) {
2530                         adev->flags.match_driver = true;
2531                         if (device_attach(&adev->dev) < 0)
2532                                 dev_dbg(&adev->dev, "No driver\n");
2533                 }
2534         }
2535 }
2536
2537 static void __init acpi_get_spcr_uart_addr(void)
2538 {
2539         acpi_status status;
2540         struct acpi_table_spcr *spcr_ptr;
2541
2542         status = acpi_get_table(ACPI_SIG_SPCR, 0,
2543                                 (struct acpi_table_header **)&spcr_ptr);
2544         if (ACPI_FAILURE(status)) {
2545                 pr_warn("STAO table present, but SPCR is missing\n");
2546                 return;
2547         }
2548
2549         spcr_uart_addr = spcr_ptr->serial_port.address;
2550         acpi_put_table((struct acpi_table_header *)spcr_ptr);
2551 }
2552
2553 static bool acpi_scan_initialized;
2554
2555 void __init acpi_scan_init(void)
2556 {
2557         acpi_status status;
2558         struct acpi_table_stao *stao_ptr;
2559
2560         acpi_pci_root_init();
2561         acpi_pci_link_init();
2562         acpi_processor_init();
2563         acpi_platform_init();
2564         acpi_lpss_init();
2565         acpi_apd_init();
2566         acpi_cmos_rtc_init();
2567         acpi_container_init();
2568         acpi_memory_hotplug_init();
2569         acpi_watchdog_init();
2570         acpi_pnp_init();
2571         acpi_int340x_thermal_init();
2572         acpi_amba_init();
2573         acpi_init_lpit();
2574
2575         acpi_scan_add_handler(&generic_device_handler);
2576
2577         /*
2578          * If there is STAO table, check whether it needs to ignore the UART
2579          * device in SPCR table.
2580          */
2581         status = acpi_get_table(ACPI_SIG_STAO, 0,
2582                                 (struct acpi_table_header **)&stao_ptr);
2583         if (ACPI_SUCCESS(status)) {
2584                 if (stao_ptr->header.length > sizeof(struct acpi_table_stao))
2585                         pr_info("STAO Name List not yet supported.\n");
2586
2587                 if (stao_ptr->ignore_uart)
2588                         acpi_get_spcr_uart_addr();
2589
2590                 acpi_put_table((struct acpi_table_header *)stao_ptr);
2591         }
2592
2593         acpi_gpe_apply_masked_gpes();
2594         acpi_update_all_gpes();
2595
2596         /*
2597          * Although we call __add_memory() that is documented to require the
2598          * device_hotplug_lock, it is not necessary here because this is an
2599          * early code when userspace or any other code path cannot trigger
2600          * hotplug/hotunplug operations.
2601          */
2602         mutex_lock(&acpi_scan_lock);
2603         /*
2604          * Enumerate devices in the ACPI namespace.
2605          */
2606         if (acpi_bus_scan(ACPI_ROOT_OBJECT))
2607                 goto unlock;
2608
2609         acpi_root = acpi_fetch_acpi_dev(ACPI_ROOT_OBJECT);
2610         if (!acpi_root)
2611                 goto unlock;
2612
2613         /* Fixed feature devices do not exist on HW-reduced platform */
2614         if (!acpi_gbl_reduced_hardware)
2615                 acpi_bus_scan_fixed();
2616
2617         acpi_turn_off_unused_power_resources();
2618
2619         acpi_scan_initialized = true;
2620
2621 unlock:
2622         mutex_unlock(&acpi_scan_lock);
2623 }
2624
2625 static struct acpi_probe_entry *ape;
2626 static int acpi_probe_count;
2627 static DEFINE_MUTEX(acpi_probe_mutex);
2628
2629 static int __init acpi_match_madt(union acpi_subtable_headers *header,
2630                                   const unsigned long end)
2631 {
2632         if (!ape->subtable_valid || ape->subtable_valid(&header->common, ape))
2633                 if (!ape->probe_subtbl(header, end))
2634                         acpi_probe_count++;
2635
2636         return 0;
2637 }
2638
2639 int __init __acpi_probe_device_table(struct acpi_probe_entry *ap_head, int nr)
2640 {
2641         int count = 0;
2642
2643         if (acpi_disabled)
2644                 return 0;
2645
2646         mutex_lock(&acpi_probe_mutex);
2647         for (ape = ap_head; nr; ape++, nr--) {
2648                 if (ACPI_COMPARE_NAMESEG(ACPI_SIG_MADT, ape->id)) {
2649                         acpi_probe_count = 0;
2650                         acpi_table_parse_madt(ape->type, acpi_match_madt, 0);
2651                         count += acpi_probe_count;
2652                 } else {
2653                         int res;
2654                         res = acpi_table_parse(ape->id, ape->probe_table);
2655                         if (!res)
2656                                 count++;
2657                 }
2658         }
2659         mutex_unlock(&acpi_probe_mutex);
2660
2661         return count;
2662 }
2663
2664 static void acpi_table_events_fn(struct work_struct *work)
2665 {
2666         acpi_scan_lock_acquire();
2667         acpi_bus_scan(ACPI_ROOT_OBJECT);
2668         acpi_scan_lock_release();
2669
2670         kfree(work);
2671 }
2672
2673 void acpi_scan_table_notify(void)
2674 {
2675         struct work_struct *work;
2676
2677         if (!acpi_scan_initialized)
2678                 return;
2679
2680         work = kmalloc(sizeof(*work), GFP_KERNEL);
2681         if (!work)
2682                 return;
2683
2684         INIT_WORK(work, acpi_table_events_fn);
2685         schedule_work(work);
2686 }
2687
2688 int acpi_reconfig_notifier_register(struct notifier_block *nb)
2689 {
2690         return blocking_notifier_chain_register(&acpi_reconfig_chain, nb);
2691 }
2692 EXPORT_SYMBOL(acpi_reconfig_notifier_register);
2693
2694 int acpi_reconfig_notifier_unregister(struct notifier_block *nb)
2695 {
2696         return blocking_notifier_chain_unregister(&acpi_reconfig_chain, nb);
2697 }
2698 EXPORT_SYMBOL(acpi_reconfig_notifier_unregister);