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