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 INVALID_ACPI_HANDLE     ((acpi_handle)empty_zero_page)
  33
  34 static const char *dummy_hid = "device";
  35
  36 static LIST_HEAD(acpi_dep_list);
  37 static DEFINE_MUTEX(acpi_dep_list_lock);
  38 LIST_HEAD(acpi_bus_id_list);
  39 static DEFINE_MUTEX(acpi_scan_lock);
  40 static LIST_HEAD(acpi_scan_handlers_list);
  41 DEFINE_MUTEX(acpi_device_lock);
  42 LIST_HEAD(acpi_wakeup_device_list);
  43 static DEFINE_MUTEX(acpi_hp_context_lock);
  44
  45 /*
  46  * The UART device described by the SPCR table is the only object which needs
  47  * special-casing. Everything else is covered by ACPI namespace paths in STAO
  48  * table.
  49  */
  50 static u64 spcr_uart_addr;
  51
  52 void acpi_scan_lock_acquire(void)
  53 {
  54         mutex_lock(&acpi_scan_lock);
  55 }
  56 EXPORT_SYMBOL_GPL(acpi_scan_lock_acquire);
  57
  58 void acpi_scan_lock_release(void)
  59 {
  60         mutex_unlock(&acpi_scan_lock);
  61 }
  62 EXPORT_SYMBOL_GPL(acpi_scan_lock_release);
  63
  64 void acpi_lock_hp_context(void)
  65 {
  66         mutex_lock(&acpi_hp_context_lock);
  67 }
  68
  69 void acpi_unlock_hp_context(void)
  70 {
  71         mutex_unlock(&acpi_hp_context_lock);
  72 }
  73
  74 void acpi_initialize_hp_context(struct acpi_device *adev,
  75                                 struct acpi_hotplug_context *hp,
  76                                 int (*notify)(struct acpi_device *, u32),
  77                                 void (*uevent)(struct acpi_device *, u32))
  78 {
  79         acpi_lock_hp_context();
  80         hp->notify = notify;
  81         hp->uevent = uevent;
  82         acpi_set_hp_context(adev, hp);
  83         acpi_unlock_hp_context();
  84 }
  85 EXPORT_SYMBOL_GPL(acpi_initialize_hp_context);
  86
  87 int acpi_scan_add_handler(struct acpi_scan_handler *handler)
  88 {
  89         if (!handler)
  90                 return -EINVAL;
  91
  92         list_add_tail(&handler->list_node, &acpi_scan_handlers_list);
  93         return 0;
  94 }
  95
  96 int acpi_scan_add_handler_with_hotplug(struct acpi_scan_handler *handler,
  97                                        const char *hotplug_profile_name)
  98 {
  99         int error;
 100
 101         error = acpi_scan_add_handler(handler);
 102         if (error)
 103                 return error;
 104
 105         acpi_sysfs_add_hotplug_profile(&handler->hotplug, hotplug_profile_name);
 106         return 0;
 107 }
 108
 109 bool acpi_scan_is_offline(struct acpi_device *adev, bool uevent)
 110 {
 111         struct acpi_device_physical_node *pn;
 112         bool offline = true;
 113         char *envp[] = { "EVENT=offline", NULL };
 114
 115         /*
 116          * acpi_container_offline() calls this for all of the container's
 117          * children under the container's physical_node_lock lock.
 118          */
 119         mutex_lock_nested(&adev->physical_node_lock, SINGLE_DEPTH_NESTING);
 120
 121         list_for_each_entry(pn, &adev->physical_node_list, node)
 122                 if (device_supports_offline(pn->dev) && !pn->dev->offline) {
 123                         if (uevent)
 124                                 kobject_uevent_env(&pn->dev->kobj, KOBJ_CHANGE, envp);
 125
 126                         offline = false;
 127                         break;
 128                 }
 129
 130         mutex_unlock(&adev->physical_node_lock);
 131         return offline;
 132 }
 133
 134 static acpi_status acpi_bus_offline(acpi_handle handle, u32 lvl, void *data,
 135                                     void **ret_p)
 136 {
 137         struct acpi_device *device = acpi_fetch_acpi_dev(handle);
 138         struct acpi_device_physical_node *pn;
 139         bool second_pass = (bool)data;
 140         acpi_status status = AE_OK;
 141
 142         if (!device)
 143                 return AE_OK;
 144
 145         if (device->handler && !device->handler->hotplug.enabled) {
 146                 *ret_p = &device->dev;
 147                 return AE_SUPPORT;
 148         }
 149
 150         mutex_lock(&device->physical_node_lock);
 151
 152         list_for_each_entry(pn, &device->physical_node_list, node) {
 153                 int ret;
 154
 155                 if (second_pass) {
 156                         /* Skip devices offlined by the first pass. */
 157                         if (pn->put_online)
 158                                 continue;
 159                 } else {
 160                         pn->put_online = false;
 161                 }
 162                 ret = device_offline(pn->dev);
 163                 if (ret >= 0) {
 164                         pn->put_online = !ret;
 165                 } else {
 166                         *ret_p = pn->dev;
 167                         if (second_pass) {
 168                                 status = AE_ERROR;
 169                                 break;
 170                         }
 171                 }
 172         }
 173
 174         mutex_unlock(&device->physical_node_lock);
 175
 176         return status;
 177 }
 178
 179 static acpi_status acpi_bus_online(acpi_handle handle, u32 lvl, void *data,
 180                                    void **ret_p)
 181 {
 182         struct acpi_device *device = acpi_fetch_acpi_dev(handle);
 183         struct acpi_device_physical_node *pn;
 184
 185         if (!device)
 186                 return AE_OK;
 187
 188         mutex_lock(&device->physical_node_lock);
 189
 190         list_for_each_entry(pn, &device->physical_node_list, node)
 191                 if (pn->put_online) {
 192                         device_online(pn->dev);
 193                         pn->put_online = false;
 194                 }
 195
 196         mutex_unlock(&device->physical_node_lock);
 197
 198         return AE_OK;
 199 }
 200
 201 static int acpi_scan_try_to_offline(struct acpi_device *device)
 202 {
 203         acpi_handle handle = device->handle;
 204         struct device *errdev = NULL;
 205         acpi_status status;
 206
 207         /*
 208          * Carry out two passes here and ignore errors in the first pass,
 209          * because if the devices in question are memory blocks and
 210          * CONFIG_MEMCG is set, one of the blocks may hold data structures
 211          * that the other blocks depend on, but it is not known in advance which
 212          * block holds them.
 213          *
 214          * If the first pass is successful, the second one isn't needed, though.
 215          */
 216         status = acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
 217                                      NULL, acpi_bus_offline, (void *)false,
 218                                      (void **)&errdev);
 219         if (status == AE_SUPPORT) {
 220                 dev_warn(errdev, "Offline disabled.\n");
 221                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
 222                                     acpi_bus_online, NULL, NULL, NULL);
 223                 return -EPERM;
 224         }
 225         acpi_bus_offline(handle, 0, (void *)false, (void **)&errdev);
 226         if (errdev) {
 227                 errdev = NULL;
 228                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
 229                                     NULL, acpi_bus_offline, (void *)true,
 230                                     (void **)&errdev);
 231                 if (!errdev)
 232                         acpi_bus_offline(handle, 0, (void *)true,
 233                                          (void **)&errdev);
 234
 235                 if (errdev) {
 236                         dev_warn(errdev, "Offline failed.\n");
 237                         acpi_bus_online(handle, 0, NULL, NULL);
 238                         acpi_walk_namespace(ACPI_TYPE_ANY, handle,
 239                                             ACPI_UINT32_MAX, acpi_bus_online,
 240                                             NULL, NULL, NULL);
 241                         return -EBUSY;
 242                 }
 243         }
 244         return 0;
 245 }
 246
 247 static int acpi_scan_hot_remove(struct acpi_device *device)
 248 {
 249         acpi_handle handle = device->handle;
 250         unsigned long long sta;
 251         acpi_status status;
 252
 253         if (device->handler && device->handler->hotplug.demand_offline) {
 254                 if (!acpi_scan_is_offline(device, true))
 255                         return -EBUSY;
 256         } else {
 257                 int error = acpi_scan_try_to_offline(device);
 258                 if (error)
 259                         return error;
 260         }
 261
 262         acpi_handle_debug(handle, "Ejecting\n");
 263
 264         acpi_bus_trim(device);
 265
 266         acpi_evaluate_lck(handle, 0);
 267         /*
 268          * TBD: _EJD support.
 269          */
 270         status = acpi_evaluate_ej0(handle);
 271         if (status == AE_NOT_FOUND)
 272                 return -ENODEV;
 273         else if (ACPI_FAILURE(status))
 274                 return -EIO;
 275
 276         /*
 277          * Verify if eject was indeed successful.  If not, log an error
 278          * message.  No need to call _OST since _EJ0 call was made OK.
 279          */
 280         status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
 281         if (ACPI_FAILURE(status)) {
 282                 acpi_handle_warn(handle,
 283                         "Status check after eject failed (0x%x)\n", status);
 284         } else if (sta & ACPI_STA_DEVICE_ENABLED) {
 285                 acpi_handle_warn(handle,
 286                         "Eject incomplete - status 0x%llx\n", sta);
 287         }
 288
 289         return 0;
 290 }
 291
 292 static int acpi_scan_device_not_present(struct acpi_device *adev)
 293 {
 294         if (!acpi_device_enumerated(adev)) {
 295                 dev_warn(&adev->dev, "Still not present\n");
 296                 return -EALREADY;
 297         }
 298         acpi_bus_trim(adev);
 299         return 0;
 300 }
 301
 302 static int acpi_scan_device_check(struct acpi_device *adev)
 303 {
 304         int error;
 305
 306         acpi_bus_get_status(adev);
 307         if (adev->status.present || adev->status.functional) {
 308                 /*
 309                  * This function is only called for device objects for which
 310                  * matching scan handlers exist.  The only situation in which
 311                  * the scan handler is not attached to this device object yet
 312                  * is when the device has just appeared (either it wasn't
 313                  * present at all before or it was removed and then added
 314                  * again).
 315                  */
 316                 if (adev->handler) {
 317                         dev_warn(&adev->dev, "Already enumerated\n");
 318                         return -EALREADY;
 319                 }
 320                 error = acpi_bus_scan(adev->handle);
 321                 if (error) {
 322                         dev_warn(&adev->dev, "Namespace scan failure\n");
 323                         return error;
 324                 }
 325                 if (!adev->handler) {
 326                         dev_warn(&adev->dev, "Enumeration failure\n");
 327                         error = -ENODEV;
 328                 }
 329         } else {
 330                 error = acpi_scan_device_not_present(adev);
 331         }
 332         return error;
 333 }
 334
 335 static int acpi_scan_bus_check(struct acpi_device *adev, void *not_used)
 336 {
 337         struct acpi_scan_handler *handler = adev->handler;
 338         int error;
 339
 340         acpi_bus_get_status(adev);
 341         if (!(adev->status.present || adev->status.functional)) {
 342                 acpi_scan_device_not_present(adev);
 343                 return 0;
 344         }
 345         if (handler && handler->hotplug.scan_dependent)
 346                 return handler->hotplug.scan_dependent(adev);
 347
 348         error = acpi_bus_scan(adev->handle);
 349         if (error) {
 350                 dev_warn(&adev->dev, "Namespace scan failure\n");
 351                 return error;
 352         }
 353         return acpi_dev_for_each_child(adev, acpi_scan_bus_check, NULL);
 354 }
 355
 356 static int acpi_generic_hotplug_event(struct acpi_device *adev, u32 type)
 357 {
 358         switch (type) {
 359         case ACPI_NOTIFY_BUS_CHECK:
 360                 return acpi_scan_bus_check(adev, NULL);
 361         case ACPI_NOTIFY_DEVICE_CHECK:
 362                 return acpi_scan_device_check(adev);
 363         case ACPI_NOTIFY_EJECT_REQUEST:
 364         case ACPI_OST_EC_OSPM_EJECT:
 365                 if (adev->handler && !adev->handler->hotplug.enabled) {
 366                         dev_info(&adev->dev, "Eject disabled\n");
 367                         return -EPERM;
 368                 }
 369                 acpi_evaluate_ost(adev->handle, ACPI_NOTIFY_EJECT_REQUEST,
 370                                   ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
 371                 return acpi_scan_hot_remove(adev);
 372         }
 373         return -EINVAL;
 374 }
 375
 376 void acpi_device_hotplug(struct acpi_device *adev, u32 src)
 377 {
 378         u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
 379         int error = -ENODEV;
 380
 381         lock_device_hotplug();
 382         mutex_lock(&acpi_scan_lock);
 383
 384         /*
 385          * The device object's ACPI handle cannot become invalid as long as we
 386          * are holding acpi_scan_lock, but it might have become invalid before
 387          * that lock was acquired.
 388          */
 389         if (adev->handle == INVALID_ACPI_HANDLE)
 390                 goto err_out;
 391
 392         if (adev->flags.is_dock_station) {
 393                 error = dock_notify(adev, src);
 394         } else if (adev->flags.hotplug_notify) {
 395                 error = acpi_generic_hotplug_event(adev, src);
 396         } else {
 397                 int (*notify)(struct acpi_device *, u32);
 398
 399                 acpi_lock_hp_context();
 400                 notify = adev->hp ? adev->hp->notify : NULL;
 401                 acpi_unlock_hp_context();
 402                 /*
 403                  * There may be additional notify handlers for device objects
 404                  * without the .event() callback, so ignore them here.
 405                  */
 406                 if (notify)
 407                         error = notify(adev, src);
 408                 else
 409                         goto out;
 410         }
 411         switch (error) {
 412         case 0:
 413                 ost_code = ACPI_OST_SC_SUCCESS;
 414                 break;
 415         case -EPERM:
 416                 ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
 417                 break;
 418         case -EBUSY:
 419                 ost_code = ACPI_OST_SC_DEVICE_BUSY;
 420                 break;
 421         default:
 422                 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
 423                 break;
 424         }
 425
 426  err_out:
 427         acpi_evaluate_ost(adev->handle, src, ost_code, NULL);
 428
 429  out:
 430         acpi_put_acpi_dev(adev);
 431         mutex_unlock(&acpi_scan_lock);
 432         unlock_device_hotplug();
 433 }
 434
 435 static void acpi_free_power_resources_lists(struct acpi_device *device)
 436 {
 437         int i;
 438
 439         if (device->wakeup.flags.valid)
 440                 acpi_power_resources_list_free(&device->wakeup.resources);
 441
 442         if (!device->power.flags.power_resources)
 443                 return;
 444
 445         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
 446                 struct acpi_device_power_state *ps = &device->power.states[i];
 447                 acpi_power_resources_list_free(&ps->resources);
 448         }
 449 }
 450
 451 static void acpi_device_release(struct device *dev)
 452 {
 453         struct acpi_device *acpi_dev = to_acpi_device(dev);
 454
 455         acpi_free_properties(acpi_dev);
 456         acpi_free_pnp_ids(&acpi_dev->pnp);
 457         acpi_free_power_resources_lists(acpi_dev);
 458         kfree(acpi_dev);
 459 }
 460
 461 static void acpi_device_del(struct acpi_device *device)
 462 {
 463         struct acpi_device_bus_id *acpi_device_bus_id;
 464
 465         mutex_lock(&acpi_device_lock);
 466
 467         list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node)
 468                 if (!strcmp(acpi_device_bus_id->bus_id,
 469                             acpi_device_hid(device))) {
 470                         ida_free(&acpi_device_bus_id->instance_ida,
 471                                  device->pnp.instance_no);
 472                         if (ida_is_empty(&acpi_device_bus_id->instance_ida)) {
 473                                 list_del(&acpi_device_bus_id->node);
 474                                 kfree_const(acpi_device_bus_id->bus_id);
 475                                 kfree(acpi_device_bus_id);
 476                         }
 477                         break;
 478                 }
 479
 480         list_del(&device->wakeup_list);
 481
 482         mutex_unlock(&acpi_device_lock);
 483
 484         acpi_power_add_remove_device(device, false);
 485         acpi_device_remove_files(device);
 486         if (device->remove)
 487                 device->remove(device);
 488
 489         device_del(&device->dev);
 490 }
 491
 492 static BLOCKING_NOTIFIER_HEAD(acpi_reconfig_chain);
 493
 494 static LIST_HEAD(acpi_device_del_list);
 495 static DEFINE_MUTEX(acpi_device_del_lock);
 496
 497 static void acpi_device_del_work_fn(struct work_struct *work_not_used)
 498 {
 499         for (;;) {
 500                 struct acpi_device *adev;
 501
 502                 mutex_lock(&acpi_device_del_lock);
 503
 504                 if (list_empty(&acpi_device_del_list)) {
 505                         mutex_unlock(&acpi_device_del_lock);
 506                         break;
 507                 }
 508                 adev = list_first_entry(&acpi_device_del_list,
 509                                         struct acpi_device, del_list);
 510                 list_del(&adev->del_list);
 511
 512                 mutex_unlock(&acpi_device_del_lock);
 513
 514                 blocking_notifier_call_chain(&acpi_reconfig_chain,
 515                                              ACPI_RECONFIG_DEVICE_REMOVE, adev);
 516
 517                 acpi_device_del(adev);
 518                 /*
 519                  * Drop references to all power resources that might have been
 520                  * used by the device.
 521                  */
 522                 acpi_power_transition(adev, ACPI_STATE_D3_COLD);
 523                 acpi_dev_put(adev);
 524         }
 525 }
 526
 527 /**
 528  * acpi_scan_drop_device - Drop an ACPI device object.
 529  * @handle: Handle of an ACPI namespace node, not used.
 530  * @context: Address of the ACPI device object to drop.
 531  *
 532  * This is invoked by acpi_ns_delete_node() during the removal of the ACPI
 533  * namespace node the device object pointed to by @context is attached to.
 534  *
 535  * The unregistration is carried out asynchronously to avoid running
 536  * acpi_device_del() under the ACPICA's namespace mutex and the list is used to
 537  * ensure the correct ordering (the device objects must be unregistered in the
 538  * same order in which the corresponding namespace nodes are deleted).
 539  */
 540 static void acpi_scan_drop_device(acpi_handle handle, void *context)
 541 {
 542         static DECLARE_WORK(work, acpi_device_del_work_fn);
 543         struct acpi_device *adev = context;
 544
 545         mutex_lock(&acpi_device_del_lock);
 546
 547         /*
 548          * Use the ACPI hotplug workqueue which is ordered, so this work item
 549          * won't run after any hotplug work items submitted subsequently.  That
 550          * prevents attempts to register device objects identical to those being
 551          * deleted from happening concurrently (such attempts result from
 552          * hotplug events handled via the ACPI hotplug workqueue).  It also will
 553          * run after all of the work items submitted previously, which helps
 554          * those work items to ensure that they are not accessing stale device
 555          * objects.
 556          */
 557         if (list_empty(&acpi_device_del_list))
 558                 acpi_queue_hotplug_work(&work);
 559
 560         list_add_tail(&adev->del_list, &acpi_device_del_list);
 561         /* Make acpi_ns_validate_handle() return NULL for this handle. */
 562         adev->handle = INVALID_ACPI_HANDLE;
 563
 564         mutex_unlock(&acpi_device_del_lock);
 565 }
 566
 567 static struct acpi_device *handle_to_device(acpi_handle handle,
 568                                             void (*callback)(void *))
 569 {
 570         struct acpi_device *adev = NULL;
 571         acpi_status status;
 572
 573         status = acpi_get_data_full(handle, acpi_scan_drop_device,
 574                                     (void **)&adev, callback);
 575         if (ACPI_FAILURE(status) || !adev) {
 576                 acpi_handle_debug(handle, "No context!\n");
 577                 return NULL;
 578         }
 579         return adev;
 580 }
 581
 582 /**
 583  * acpi_fetch_acpi_dev - Retrieve ACPI device object.
 584  * @handle: ACPI handle associated with the requested ACPI device object.
 585  *
 586  * Return a pointer to the ACPI device object associated with @handle, if
 587  * present, or NULL otherwise.
 588  */
 589 struct acpi_device *acpi_fetch_acpi_dev(acpi_handle handle)
 590 {
 591         return handle_to_device(handle, NULL);
 592 }
 593 EXPORT_SYMBOL_GPL(acpi_fetch_acpi_dev);
 594
 595 static void get_acpi_device(void *dev)
 596 {
 597         acpi_dev_get(dev);
 598 }
 599
 600 /**
 601  * acpi_get_acpi_dev - Retrieve ACPI device object and reference count it.
 602  * @handle: ACPI handle associated with the requested ACPI device object.
 603  *
 604  * Return a pointer to the ACPI device object associated with @handle and bump
 605  * up that object's reference counter (under the ACPI Namespace lock), if
 606  * present, or return NULL otherwise.
 607  *
 608  * The ACPI device object reference acquired by this function needs to be
 609  * dropped via acpi_dev_put().
 610  */
 611 struct acpi_device *acpi_get_acpi_dev(acpi_handle handle)
 612 {
 613         return handle_to_device(handle, get_acpi_device);
 614 }
 615 EXPORT_SYMBOL_GPL(acpi_get_acpi_dev);
 616
 617 static struct acpi_device_bus_id *acpi_device_bus_id_match(const char *dev_id)
 618 {
 619         struct acpi_device_bus_id *acpi_device_bus_id;
 620
 621         /* Find suitable bus_id and instance number in acpi_bus_id_list. */
 622         list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
 623                 if (!strcmp(acpi_device_bus_id->bus_id, dev_id))
 624                         return acpi_device_bus_id;
 625         }
 626         return NULL;
 627 }
 628
 629 static int acpi_device_set_name(struct acpi_device *device,
 630                                 struct acpi_device_bus_id *acpi_device_bus_id)
 631 {
 632         struct ida *instance_ida = &acpi_device_bus_id->instance_ida;
 633         int result;
 634
 635         result = ida_alloc(instance_ida, GFP_KERNEL);
 636         if (result < 0)
 637                 return result;
 638
 639         device->pnp.instance_no = result;
 640         dev_set_name(&device->dev, "%s:%02x", acpi_device_bus_id->bus_id, result);
 641         return 0;
 642 }
 643
 644 int acpi_tie_acpi_dev(struct acpi_device *adev)
 645 {
 646         acpi_handle handle = adev->handle;
 647         acpi_status status;
 648
 649         if (!handle)
 650                 return 0;
 651
 652         status = acpi_attach_data(handle, acpi_scan_drop_device, adev);
 653         if (ACPI_FAILURE(status)) {
 654                 acpi_handle_err(handle, "Unable to attach device data\n");
 655                 return -ENODEV;
 656         }
 657
 658         return 0;
 659 }
 660
 661 static void acpi_store_pld_crc(struct acpi_device *adev)
 662 {
 663         struct acpi_pld_info *pld;
 664         acpi_status status;
 665
 666         status = acpi_get_physical_device_location(adev->handle, &pld);
 667         if (ACPI_FAILURE(status))
 668                 return;
 669
 670         adev->pld_crc = crc32(~0, pld, sizeof(*pld));
 671         ACPI_FREE(pld);
 672 }
 673
 674 int acpi_device_add(struct acpi_device *device)
 675 {
 676         struct acpi_device_bus_id *acpi_device_bus_id;
 677         int result;
 678
 679         /*
 680          * Linkage
 681          * -------
 682          * Link this device to its parent and siblings.
 683          */
 684         INIT_LIST_HEAD(&device->wakeup_list);
 685         INIT_LIST_HEAD(&device->physical_node_list);
 686         INIT_LIST_HEAD(&device->del_list);
 687         mutex_init(&device->physical_node_lock);
 688
 689         mutex_lock(&acpi_device_lock);
 690
 691         acpi_device_bus_id = acpi_device_bus_id_match(acpi_device_hid(device));
 692         if (acpi_device_bus_id) {
 693                 result = acpi_device_set_name(device, acpi_device_bus_id);
 694                 if (result)
 695                         goto err_unlock;
 696         } else {
 697                 acpi_device_bus_id = kzalloc(sizeof(*acpi_device_bus_id),
 698                                              GFP_KERNEL);
 699                 if (!acpi_device_bus_id) {
 700                         result = -ENOMEM;
 701                         goto err_unlock;
 702                 }
 703                 acpi_device_bus_id->bus_id =
 704                         kstrdup_const(acpi_device_hid(device), GFP_KERNEL);
 705                 if (!acpi_device_bus_id->bus_id) {
 706                         kfree(acpi_device_bus_id);
 707                         result = -ENOMEM;
 708                         goto err_unlock;
 709                 }
 710
 711                 ida_init(&acpi_device_bus_id->instance_ida);
 712
 713                 result = acpi_device_set_name(device, acpi_device_bus_id);
 714                 if (result) {
 715                         kfree_const(acpi_device_bus_id->bus_id);
 716                         kfree(acpi_device_bus_id);
 717                         goto err_unlock;
 718                 }
 719
 720                 list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
 721         }
 722
 723         if (device->wakeup.flags.valid)
 724                 list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);
 725
 726         acpi_store_pld_crc(device);
 727
 728         mutex_unlock(&acpi_device_lock);
 729
 730         result = device_add(&device->dev);
 731         if (result) {
 732                 dev_err(&device->dev, "Error registering device\n");
 733                 goto err;
 734         }
 735
 736         result = acpi_device_setup_files(device);
 737         if (result)
 738                 pr_err("Error creating sysfs interface for device %s\n",
 739                        dev_name(&device->dev));
 740
 741         return 0;
 742
 743 err:
 744         mutex_lock(&acpi_device_lock);
 745
 746         list_del(&device->wakeup_list);
 747
 748 err_unlock:
 749         mutex_unlock(&acpi_device_lock);
 750
 751         acpi_detach_data(device->handle, acpi_scan_drop_device);
 752
 753         return result;
 754 }
 755
 756 /* --------------------------------------------------------------------------
 757                                  Device Enumeration
 758    -------------------------------------------------------------------------- */
 759 static bool acpi_info_matches_ids(struct acpi_device_info *info,
 760                                   const char * const ids[])
 761 {
 762         struct acpi_pnp_device_id_list *cid_list = NULL;
 763         int i, index;
 764
 765         if (!(info->valid & ACPI_VALID_HID))
 766                 return false;
 767
 768         index = match_string(ids, -1, info->hardware_id.string);
 769         if (index >= 0)
 770                 return true;
 771
 772         if (info->valid & ACPI_VALID_CID)
 773                 cid_list = &info->compatible_id_list;
 774
 775         if (!cid_list)
 776                 return false;
 777
 778         for (i = 0; i < cid_list->count; i++) {
 779                 index = match_string(ids, -1, cid_list->ids[i].string);
 780                 if (index >= 0)
 781                         return true;
 782         }
 783
 784         return false;
 785 }
 786
 787 /* List of HIDs for which we ignore matching ACPI devices, when checking _DEP lists. */
 788 static const char * const acpi_ignore_dep_ids[] = {
 789         "PNP0D80", /* Windows-compatible System Power Management Controller */
 790         "INT33BD", /* Intel Baytrail Mailbox Device */
 791         NULL
 792 };
 793
 794 /* List of HIDs for which we honor deps of matching ACPI devs, when checking _DEP lists. */
 795 static const char * const acpi_honor_dep_ids[] = {
 796         "INT3472", /* Camera sensor PMIC / clk and regulator info */
 797         NULL
 798 };
 799
 800 static struct acpi_device *acpi_find_parent_acpi_dev(acpi_handle handle)
 801 {
 802         struct acpi_device *adev;
 803
 804         /*
 805          * Fixed hardware devices do not appear in the namespace and do not
 806          * have handles, but we fabricate acpi_devices for them, so we have
 807          * to deal with them specially.
 808          */
 809         if (!handle)
 810                 return acpi_root;
 811
 812         do {
 813                 acpi_status status;
 814
 815                 status = acpi_get_parent(handle, &handle);
 816                 if (ACPI_FAILURE(status)) {
 817                         if (status != AE_NULL_ENTRY)
 818                                 return acpi_root;
 819
 820                         return NULL;
 821                 }
 822                 adev = acpi_fetch_acpi_dev(handle);
 823         } while (!adev);
 824         return adev;
 825 }
 826
 827 acpi_status
 828 acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
 829 {
 830         acpi_status status;
 831         acpi_handle tmp;
 832         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
 833         union acpi_object *obj;
 834
 835         status = acpi_get_handle(handle, "_EJD", &tmp);
 836         if (ACPI_FAILURE(status))
 837                 return status;
 838
 839         status = acpi_evaluate_object(handle, "_EJD", NULL, &buffer);
 840         if (ACPI_SUCCESS(status)) {
 841                 obj = buffer.pointer;
 842                 status = acpi_get_handle(ACPI_ROOT_OBJECT, obj->string.pointer,
 843                                          ejd);
 844                 kfree(buffer.pointer);
 845         }
 846         return status;
 847 }
 848 EXPORT_SYMBOL_GPL(acpi_bus_get_ejd);
 849
 850 static int acpi_bus_extract_wakeup_device_power_package(struct acpi_device *dev)
 851 {
 852         acpi_handle handle = dev->handle;
 853         struct acpi_device_wakeup *wakeup = &dev->wakeup;
 854         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 855         union acpi_object *package = NULL;
 856         union acpi_object *element = NULL;
 857         acpi_status status;
 858         int err = -ENODATA;
 859
 860         INIT_LIST_HEAD(&wakeup->resources);
 861
 862         /* _PRW */
 863         status = acpi_evaluate_object(handle, "_PRW", NULL, &buffer);
 864         if (ACPI_FAILURE(status)) {
 865                 acpi_handle_info(handle, "_PRW evaluation failed: %s\n",
 866                                  acpi_format_exception(status));
 867                 return err;
 868         }
 869
 870         package = (union acpi_object *)buffer.pointer;
 871
 872         if (!package || package->package.count < 2)
 873                 goto out;
 874
 875         element = &(package->package.elements[0]);
 876         if (!element)
 877                 goto out;
 878
 879         if (element->type == ACPI_TYPE_PACKAGE) {
 880                 if ((element->package.count < 2) ||
 881                     (element->package.elements[0].type !=
 882                      ACPI_TYPE_LOCAL_REFERENCE)
 883                     || (element->package.elements[1].type != ACPI_TYPE_INTEGER))
 884                         goto out;
 885
 886                 wakeup->gpe_device =
 887                     element->package.elements[0].reference.handle;
 888                 wakeup->gpe_number =
 889                     (u32) element->package.elements[1].integer.value;
 890         } else if (element->type == ACPI_TYPE_INTEGER) {
 891                 wakeup->gpe_device = NULL;
 892                 wakeup->gpe_number = element->integer.value;
 893         } else {
 894                 goto out;
 895         }
 896
 897         element = &(package->package.elements[1]);
 898         if (element->type != ACPI_TYPE_INTEGER)
 899                 goto out;
 900
 901         wakeup->sleep_state = element->integer.value;
 902
 903         err = acpi_extract_power_resources(package, 2, &wakeup->resources);
 904         if (err)
 905                 goto out;
 906
 907         if (!list_empty(&wakeup->resources)) {
 908                 int sleep_state;
 909
 910                 err = acpi_power_wakeup_list_init(&wakeup->resources,
 911                                                   &sleep_state);
 912                 if (err) {
 913                         acpi_handle_warn(handle, "Retrieving current states "
 914                                          "of wakeup power resources failed\n");
 915                         acpi_power_resources_list_free(&wakeup->resources);
 916                         goto out;
 917                 }
 918                 if (sleep_state < wakeup->sleep_state) {
 919                         acpi_handle_warn(handle, "Overriding _PRW sleep state "
 920                                          "(S%d) by S%d from power resources\n",
 921                                          (int)wakeup->sleep_state, sleep_state);
 922                         wakeup->sleep_state = sleep_state;
 923                 }
 924         }
 925
 926  out:
 927         kfree(buffer.pointer);
 928         return err;
 929 }
 930
 931 static bool acpi_wakeup_gpe_init(struct acpi_device *device)
 932 {
 933         static const struct acpi_device_id button_device_ids[] = {
 934                 {"PNP0C0C", 0},         /* Power button */
 935                 {"PNP0C0D", 0},         /* Lid */
 936                 {"PNP0C0E", 0},         /* Sleep button */
 937                 {"", 0},
 938         };
 939         struct acpi_device_wakeup *wakeup = &device->wakeup;
 940         acpi_status status;
 941
 942         wakeup->flags.notifier_present = 0;
 943
 944         /* Power button, Lid switch always enable wakeup */
 945         if (!acpi_match_device_ids(device, button_device_ids)) {
 946                 if (!acpi_match_device_ids(device, &button_device_ids[1])) {
 947                         /* Do not use Lid/sleep button for S5 wakeup */
 948                         if (wakeup->sleep_state == ACPI_STATE_S5)
 949                                 wakeup->sleep_state = ACPI_STATE_S4;
 950                 }
 951                 acpi_mark_gpe_for_wake(wakeup->gpe_device, wakeup->gpe_number);
 952                 device_set_wakeup_capable(&device->dev, true);
 953                 return true;
 954         }
 955
 956         status = acpi_setup_gpe_for_wake(device->handle, wakeup->gpe_device,
 957                                          wakeup->gpe_number);
 958         return ACPI_SUCCESS(status);
 959 }
 960
 961 static void acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
 962 {
 963         int err;
 964
 965         /* Presence of _PRW indicates wake capable */
 966         if (!acpi_has_method(device->handle, "_PRW"))
 967                 return;
 968
 969         err = acpi_bus_extract_wakeup_device_power_package(device);
 970         if (err) {
 971                 dev_err(&device->dev, "Unable to extract wakeup power resources");
 972                 return;
 973         }
 974
 975         device->wakeup.flags.valid = acpi_wakeup_gpe_init(device);
 976         device->wakeup.prepare_count = 0;
 977         /*
 978          * Call _PSW/_DSW object to disable its ability to wake the sleeping
 979          * system for the ACPI device with the _PRW object.
 980          * The _PSW object is deprecated in ACPI 3.0 and is replaced by _DSW.
 981          * So it is necessary to call _DSW object first. Only when it is not
 982          * present will the _PSW object used.
 983          */
 984         err = acpi_device_sleep_wake(device, 0, 0, 0);
 985         if (err)
 986                 pr_debug("error in _DSW or _PSW evaluation\n");
 987 }
 988
 989 static void acpi_bus_init_power_state(struct acpi_device *device, int state)
 990 {
 991         struct acpi_device_power_state *ps = &device->power.states[state];
 992         char pathname[5] = { '_', 'P', 'R', '0' + state, '\0' };
 993         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 994         acpi_status status;
 995
 996         INIT_LIST_HEAD(&ps->resources);
 997
 998         /* Evaluate "_PRx" to get referenced power resources */
 999         status = acpi_evaluate_object(device->handle, pathname, NULL, &buffer);
1000         if (ACPI_SUCCESS(status)) {
1001                 union acpi_object *package = buffer.pointer;
1002
1003                 if (buffer.length && package
1004                     && package->type == ACPI_TYPE_PACKAGE
1005                     && package->package.count)
1006                         acpi_extract_power_resources(package, 0, &ps->resources);
1007
1008                 ACPI_FREE(buffer.pointer);
1009         }
1010
1011         /* Evaluate "_PSx" to see if we can do explicit sets */
1012         pathname[2] = 'S';
1013         if (acpi_has_method(device->handle, pathname))
1014                 ps->flags.explicit_set = 1;
1015
1016         /* State is valid if there are means to put the device into it. */
1017         if (!list_empty(&ps->resources) || ps->flags.explicit_set)
1018                 ps->flags.valid = 1;
1019
1020         ps->power = -1;         /* Unknown - driver assigned */
1021         ps->latency = -1;       /* Unknown - driver assigned */
1022 }
1023
1024 static void acpi_bus_get_power_flags(struct acpi_device *device)
1025 {
1026         unsigned long long dsc = ACPI_STATE_D0;
1027         u32 i;
1028
1029         /* Presence of _PS0|_PR0 indicates 'power manageable' */
1030         if (!acpi_has_method(device->handle, "_PS0") &&
1031             !acpi_has_method(device->handle, "_PR0"))
1032                 return;
1033
1034         device->flags.power_manageable = 1;
1035
1036         /*
1037          * Power Management Flags
1038          */
1039         if (acpi_has_method(device->handle, "_PSC"))
1040                 device->power.flags.explicit_get = 1;
1041
1042         if (acpi_has_method(device->handle, "_IRC"))
1043                 device->power.flags.inrush_current = 1;
1044
1045         if (acpi_has_method(device->handle, "_DSW"))
1046                 device->power.flags.dsw_present = 1;
1047
1048         acpi_evaluate_integer(device->handle, "_DSC", NULL, &dsc);
1049         device->power.state_for_enumeration = dsc;
1050
1051         /*
1052          * Enumerate supported power management states
1053          */
1054         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++)
1055                 acpi_bus_init_power_state(device, i);
1056
1057         INIT_LIST_HEAD(&device->power.states[ACPI_STATE_D3_COLD].resources);
1058
1059         /* Set the defaults for D0 and D3hot (always supported). */
1060         device->power.states[ACPI_STATE_D0].flags.valid = 1;
1061         device->power.states[ACPI_STATE_D0].power = 100;
1062         device->power.states[ACPI_STATE_D3_HOT].flags.valid = 1;
1063
1064         /*
1065          * Use power resources only if the D0 list of them is populated, because
1066          * some platforms may provide _PR3 only to indicate D3cold support and
1067          * in those cases the power resources list returned by it may be bogus.
1068          */
1069         if (!list_empty(&device->power.states[ACPI_STATE_D0].resources)) {
1070                 device->power.flags.power_resources = 1;
1071                 /*
1072                  * D3cold is supported if the D3hot list of power resources is
1073                  * not empty.
1074                  */
1075                 if (!list_empty(&device->power.states[ACPI_STATE_D3_HOT].resources))
1076                         device->power.states[ACPI_STATE_D3_COLD].flags.valid = 1;
1077         }
1078
1079         if (acpi_bus_init_power(device))
1080                 device->flags.power_manageable = 0;
1081 }
1082
1083 static void acpi_bus_get_flags(struct acpi_device *device)
1084 {
1085         /* Presence of _STA indicates 'dynamic_status' */
1086         if (acpi_has_method(device->handle, "_STA"))
1087                 device->flags.dynamic_status = 1;
1088
1089         /* Presence of _RMV indicates 'removable' */
1090         if (acpi_has_method(device->handle, "_RMV"))
1091                 device->flags.removable = 1;
1092
1093         /* Presence of _EJD|_EJ0 indicates 'ejectable' */
1094         if (acpi_has_method(device->handle, "_EJD") ||
1095             acpi_has_method(device->handle, "_EJ0"))
1096                 device->flags.ejectable = 1;
1097 }
1098
1099 static void acpi_device_get_busid(struct acpi_device *device)
1100 {
1101         char bus_id[5] = { '?', 0 };
1102         struct acpi_buffer buffer = { sizeof(bus_id), bus_id };
1103         int i = 0;
1104
1105         /*
1106          * Bus ID
1107          * ------
1108          * The device's Bus ID is simply the object name.
1109          * TBD: Shouldn't this value be unique (within the ACPI namespace)?
1110          */
1111         if (!acpi_dev_parent(device)) {
1112                 strcpy(device->pnp.bus_id, "ACPI");
1113                 return;
1114         }
1115
1116         switch (device->device_type) {
1117         case ACPI_BUS_TYPE_POWER_BUTTON:
1118                 strcpy(device->pnp.bus_id, "PWRF");
1119                 break;
1120         case ACPI_BUS_TYPE_SLEEP_BUTTON:
1121                 strcpy(device->pnp.bus_id, "SLPF");
1122                 break;
1123         case ACPI_BUS_TYPE_ECDT_EC:
1124                 strcpy(device->pnp.bus_id, "ECDT");
1125                 break;
1126         default:
1127                 acpi_get_name(device->handle, ACPI_SINGLE_NAME, &buffer);
1128                 /* Clean up trailing underscores (if any) */
1129                 for (i = 3; i > 1; i--) {
1130                         if (bus_id[i] == '_')
1131                                 bus_id[i] = '\0';
1132                         else
1133                                 break;
1134                 }
1135                 strcpy(device->pnp.bus_id, bus_id);
1136                 break;
1137         }
1138 }
1139
1140 /*
1141  * acpi_ata_match - see if an acpi object is an ATA device
1142  *
1143  * If an acpi object has one of the ACPI ATA methods defined,
1144  * then we can safely call it an ATA device.
1145  */
1146 bool acpi_ata_match(acpi_handle handle)
1147 {
1148         return acpi_has_method(handle, "_GTF") ||
1149                acpi_has_method(handle, "_GTM") ||
1150                acpi_has_method(handle, "_STM") ||
1151                acpi_has_method(handle, "_SDD");
1152 }
1153
1154 /*
1155  * acpi_bay_match - see if an acpi object is an ejectable driver bay
1156  *
1157  * If an acpi object is ejectable and has one of the ACPI ATA methods defined,
1158  * then we can safely call it an ejectable drive bay
1159  */
1160 bool acpi_bay_match(acpi_handle handle)
1161 {
1162         acpi_handle phandle;
1163
1164         if (!acpi_has_method(handle, "_EJ0"))
1165                 return false;
1166         if (acpi_ata_match(handle))
1167                 return true;
1168         if (ACPI_FAILURE(acpi_get_parent(handle, &phandle)))
1169                 return false;
1170
1171         return acpi_ata_match(phandle);
1172 }
1173
1174 bool acpi_device_is_battery(struct acpi_device *adev)
1175 {
1176         struct acpi_hardware_id *hwid;
1177
1178         list_for_each_entry(hwid, &adev->pnp.ids, list)
1179                 if (!strcmp("PNP0C0A", hwid->id))
1180                         return true;
1181
1182         return false;
1183 }
1184
1185 static bool is_ejectable_bay(struct acpi_device *adev)
1186 {
1187         acpi_handle handle = adev->handle;
1188
1189         if (acpi_has_method(handle, "_EJ0") && acpi_device_is_battery(adev))
1190                 return true;
1191
1192         return acpi_bay_match(handle);
1193 }
1194
1195 /*
1196  * acpi_dock_match - see if an acpi object has a _DCK method
1197  */
1198 bool acpi_dock_match(acpi_handle handle)
1199 {
1200         return acpi_has_method(handle, "_DCK");
1201 }
1202
1203 static acpi_status
1204 acpi_backlight_cap_match(acpi_handle handle, u32 level, void *context,
1205                           void **return_value)
1206 {
1207         long *cap = context;
1208
1209         if (acpi_has_method(handle, "_BCM") &&
1210             acpi_has_method(handle, "_BCL")) {
1211                 acpi_handle_debug(handle, "Found generic backlight support\n");
1212                 *cap |= ACPI_VIDEO_BACKLIGHT;
1213                 /* We have backlight support, no need to scan further */
1214                 return AE_CTRL_TERMINATE;
1215         }
1216         return 0;
1217 }
1218
1219 /* Returns true if the ACPI object is a video device which can be
1220  * handled by video.ko.
1221  * The device will get a Linux specific CID added in scan.c to
1222  * identify the device as an ACPI graphics device
1223  * Be aware that the graphics device may not be physically present
1224  * Use acpi_video_get_capabilities() to detect general ACPI video
1225  * capabilities of present cards
1226  */
1227 long acpi_is_video_device(acpi_handle handle)
1228 {
1229         long video_caps = 0;
1230
1231         /* Is this device able to support video switching ? */
1232         if (acpi_has_method(handle, "_DOD") || acpi_has_method(handle, "_DOS"))
1233                 video_caps |= ACPI_VIDEO_OUTPUT_SWITCHING;
1234
1235         /* Is this device able to retrieve a video ROM ? */
1236         if (acpi_has_method(handle, "_ROM"))
1237                 video_caps |= ACPI_VIDEO_ROM_AVAILABLE;
1238
1239         /* Is this device able to configure which video head to be POSTed ? */
1240         if (acpi_has_method(handle, "_VPO") &&
1241             acpi_has_method(handle, "_GPD") &&
1242             acpi_has_method(handle, "_SPD"))
1243                 video_caps |= ACPI_VIDEO_DEVICE_POSTING;
1244
1245         /* Only check for backlight functionality if one of the above hit. */
1246         if (video_caps)
1247                 acpi_walk_namespace(ACPI_TYPE_DEVICE, handle,
1248                                     ACPI_UINT32_MAX, acpi_backlight_cap_match, NULL,
1249                                     &video_caps, NULL);
1250
1251         return video_caps;
1252 }
1253 EXPORT_SYMBOL(acpi_is_video_device);
1254
1255 const char *acpi_device_hid(struct acpi_device *device)
1256 {
1257         struct acpi_hardware_id *hid;
1258
1259         if (list_empty(&device->pnp.ids))
1260                 return dummy_hid;
1261
1262         hid = list_first_entry(&device->pnp.ids, struct acpi_hardware_id, list);
1263         return hid->id;
1264 }
1265 EXPORT_SYMBOL(acpi_device_hid);
1266
1267 static void acpi_add_id(struct acpi_device_pnp *pnp, const char *dev_id)
1268 {
1269         struct acpi_hardware_id *id;
1270
1271         id = kmalloc(sizeof(*id), GFP_KERNEL);
1272         if (!id)
1273                 return;
1274
1275         id->id = kstrdup_const(dev_id, GFP_KERNEL);
1276         if (!id->id) {
1277                 kfree(id);
1278                 return;
1279         }
1280
1281         list_add_tail(&id->list, &pnp->ids);
1282         pnp->type.hardware_id = 1;
1283 }
1284
1285 /*
1286  * Old IBM workstations have a DSDT bug wherein the SMBus object
1287  * lacks the SMBUS01 HID and the methods do not have the necessary "_"
1288  * prefix.  Work around this.
1289  */
1290 static bool acpi_ibm_smbus_match(acpi_handle handle)
1291 {
1292         char node_name[ACPI_PATH_SEGMENT_LENGTH];
1293         struct acpi_buffer path = { sizeof(node_name), node_name };
1294
1295         if (!dmi_name_in_vendors("IBM"))
1296                 return false;
1297
1298         /* Look for SMBS object */
1299         if (ACPI_FAILURE(acpi_get_name(handle, ACPI_SINGLE_NAME, &path)) ||
1300             strcmp("SMBS", path.pointer))
1301                 return false;
1302
1303         /* Does it have the necessary (but misnamed) methods? */
1304         if (acpi_has_method(handle, "SBI") &&
1305             acpi_has_method(handle, "SBR") &&
1306             acpi_has_method(handle, "SBW"))
1307                 return true;
1308
1309         return false;
1310 }
1311
1312 static bool acpi_object_is_system_bus(acpi_handle handle)
1313 {
1314         acpi_handle tmp;
1315
1316         if (ACPI_SUCCESS(acpi_get_handle(NULL, "\\_SB", &tmp)) &&
1317             tmp == handle)
1318                 return true;
1319         if (ACPI_SUCCESS(acpi_get_handle(NULL, "\\_TZ", &tmp)) &&
1320             tmp == handle)
1321                 return true;
1322
1323         return false;
1324 }
1325
1326 static void acpi_set_pnp_ids(acpi_handle handle, struct acpi_device_pnp *pnp,
1327                              int device_type)
1328 {
1329         struct acpi_device_info *info = NULL;
1330         struct acpi_pnp_device_id_list *cid_list;
1331         int i;
1332
1333         switch (device_type) {
1334         case ACPI_BUS_TYPE_DEVICE:
1335                 if (handle == ACPI_ROOT_OBJECT) {
1336                         acpi_add_id(pnp, ACPI_SYSTEM_HID);
1337                         break;
1338                 }
1339
1340                 acpi_get_object_info(handle, &info);
1341                 if (!info) {
1342                         pr_err("%s: Error reading device info\n", __func__);
1343                         return;
1344                 }
1345
1346                 if (info->valid & ACPI_VALID_HID) {
1347                         acpi_add_id(pnp, info->hardware_id.string);
1348                         pnp->type.platform_id = 1;
1349                 }
1350                 if (info->valid & ACPI_VALID_CID) {
1351                         cid_list = &info->compatible_id_list;
1352                         for (i = 0; i < cid_list->count; i++)
1353                                 acpi_add_id(pnp, cid_list->ids[i].string);
1354                 }
1355                 if (info->valid & ACPI_VALID_ADR) {
1356                         pnp->bus_address = info->address;
1357                         pnp->type.bus_address = 1;
1358                 }
1359                 if (info->valid & ACPI_VALID_UID)
1360                         pnp->unique_id = kstrdup(info->unique_id.string,
1361                                                         GFP_KERNEL);
1362                 if (info->valid & ACPI_VALID_CLS)
1363                         acpi_add_id(pnp, info->class_code.string);
1364
1365                 kfree(info);
1366
1367                 /*
1368                  * Some devices don't reliably have _HIDs & _CIDs, so add
1369                  * synthetic HIDs to make sure drivers can find them.
1370                  */
1371                 if (acpi_is_video_device(handle))
1372                         acpi_add_id(pnp, ACPI_VIDEO_HID);
1373                 else if (acpi_bay_match(handle))
1374                         acpi_add_id(pnp, ACPI_BAY_HID);
1375                 else if (acpi_dock_match(handle))
1376                         acpi_add_id(pnp, ACPI_DOCK_HID);
1377                 else if (acpi_ibm_smbus_match(handle))
1378                         acpi_add_id(pnp, ACPI_SMBUS_IBM_HID);
1379                 else if (list_empty(&pnp->ids) &&
1380                          acpi_object_is_system_bus(handle)) {
1381                         /* \_SB, \_TZ, LNXSYBUS */
1382                         acpi_add_id(pnp, ACPI_BUS_HID);
1383                         strcpy(pnp->device_name, ACPI_BUS_DEVICE_NAME);
1384                         strcpy(pnp->device_class, ACPI_BUS_CLASS);
1385                 }
1386
1387                 break;
1388         case ACPI_BUS_TYPE_POWER:
1389                 acpi_add_id(pnp, ACPI_POWER_HID);
1390                 break;
1391         case ACPI_BUS_TYPE_PROCESSOR:
1392                 acpi_add_id(pnp, ACPI_PROCESSOR_OBJECT_HID);
1393                 break;
1394         case ACPI_BUS_TYPE_THERMAL:
1395                 acpi_add_id(pnp, ACPI_THERMAL_HID);
1396                 break;
1397         case ACPI_BUS_TYPE_POWER_BUTTON:
1398                 acpi_add_id(pnp, ACPI_BUTTON_HID_POWERF);
1399                 break;
1400         case ACPI_BUS_TYPE_SLEEP_BUTTON:
1401                 acpi_add_id(pnp, ACPI_BUTTON_HID_SLEEPF);
1402                 break;
1403         case ACPI_BUS_TYPE_ECDT_EC:
1404                 acpi_add_id(pnp, ACPI_ECDT_HID);
1405                 break;
1406         }
1407 }
1408
1409 void acpi_free_pnp_ids(struct acpi_device_pnp *pnp)
1410 {
1411         struct acpi_hardware_id *id, *tmp;
1412
1413         list_for_each_entry_safe(id, tmp, &pnp->ids, list) {
1414                 kfree_const(id->id);
1415                 kfree(id);
1416         }
1417         kfree(pnp->unique_id);
1418 }
1419
1420 /**
1421  * acpi_dma_supported - Check DMA support for the specified device.
1422  * @adev: The pointer to acpi device
1423  *
1424  * Return false if DMA is not supported. Otherwise, return true
1425  */
1426 bool acpi_dma_supported(const struct acpi_device *adev)
1427 {
1428         if (!adev)
1429                 return false;
1430
1431         if (adev->flags.cca_seen)
1432                 return true;
1433
1434         /*
1435         * Per ACPI 6.0 sec 6.2.17, assume devices can do cache-coherent
1436         * DMA on "Intel platforms".  Presumably that includes all x86 and
1437         * ia64, and other arches will set CONFIG_ACPI_CCA_REQUIRED=y.
1438         */
1439         if (!IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED))
1440                 return true;
1441
1442         return false;
1443 }
1444
1445 /**
1446  * acpi_get_dma_attr - Check the supported DMA attr for the specified device.
1447  * @adev: The pointer to acpi device
1448  *
1449  * Return enum dev_dma_attr.
1450  */
1451 enum dev_dma_attr acpi_get_dma_attr(struct acpi_device *adev)
1452 {
1453         if (!acpi_dma_supported(adev))
1454                 return DEV_DMA_NOT_SUPPORTED;
1455
1456         if (adev->flags.coherent_dma)
1457                 return DEV_DMA_COHERENT;
1458         else
1459                 return DEV_DMA_NON_COHERENT;
1460 }
1461
1462 /**
1463  * acpi_dma_get_range() - Get device DMA parameters.
1464  *
1465  * @dev: device to configure
1466  * @dma_addr: pointer device DMA address result
1467  * @offset: pointer to the DMA offset result
1468  * @size: pointer to DMA range size result
1469  *
1470  * Evaluate DMA regions and return respectively DMA region start, offset
1471  * and size in dma_addr, offset and size on parsing success; it does not
1472  * update the passed in values on failure.
1473  *
1474  * Return 0 on success, < 0 on failure.
1475  */
1476 int acpi_dma_get_range(struct device *dev, u64 *dma_addr, u64 *offset,
1477                        u64 *size)
1478 {
1479         struct acpi_device *adev;
1480         LIST_HEAD(list);
1481         struct resource_entry *rentry;
1482         int ret;
1483         struct device *dma_dev = dev;
1484         u64 len, dma_start = U64_MAX, dma_end = 0, dma_offset = 0;
1485
1486         /*
1487          * Walk the device tree chasing an ACPI companion with a _DMA
1488          * object while we go. Stop if we find a device with an ACPI
1489          * companion containing a _DMA method.
1490          */
1491         do {
1492                 adev = ACPI_COMPANION(dma_dev);
1493                 if (adev && acpi_has_method(adev->handle, METHOD_NAME__DMA))
1494                         break;
1495
1496                 dma_dev = dma_dev->parent;
1497         } while (dma_dev);
1498
1499         if (!dma_dev)
1500                 return -ENODEV;
1501
1502         if (!acpi_has_method(adev->handle, METHOD_NAME__CRS)) {
1503                 acpi_handle_warn(adev->handle, "_DMA is valid only if _CRS is present\n");
1504                 return -EINVAL;
1505         }
1506
1507         ret = acpi_dev_get_dma_resources(adev, &list);
1508         if (ret > 0) {
1509                 list_for_each_entry(rentry, &list, node) {
1510                         if (dma_offset && rentry->offset != dma_offset) {
1511                                 ret = -EINVAL;
1512                                 dev_warn(dma_dev, "Can't handle multiple windows with different offsets\n");
1513                                 goto out;
1514                         }
1515                         dma_offset = rentry->offset;
1516
1517                         /* Take lower and upper limits */
1518                         if (rentry->res->start < dma_start)
1519                                 dma_start = rentry->res->start;
1520                         if (rentry->res->end > dma_end)
1521                                 dma_end = rentry->res->end;
1522                 }
1523
1524                 if (dma_start >= dma_end) {
1525                         ret = -EINVAL;
1526                         dev_dbg(dma_dev, "Invalid DMA regions configuration\n");
1527                         goto out;
1528                 }
1529
1530                 *dma_addr = dma_start - dma_offset;
1531                 len = dma_end - dma_start;
1532                 *size = max(len, len + 1);
1533                 *offset = dma_offset;
1534         }
1535  out:
1536         acpi_dev_free_resource_list(&list);
1537
1538         return ret >= 0 ? 0 : ret;
1539 }
1540
1541 #ifdef CONFIG_IOMMU_API
1542 int acpi_iommu_fwspec_init(struct device *dev, u32 id,
1543                            struct fwnode_handle *fwnode,
1544                            const struct iommu_ops *ops)
1545 {
1546         int ret = iommu_fwspec_init(dev, fwnode, ops);
1547
1548         if (!ret)
1549                 ret = iommu_fwspec_add_ids(dev, &id, 1);
1550
1551         return ret;
1552 }
1553
1554 static inline const struct iommu_ops *acpi_iommu_fwspec_ops(struct device *dev)
1555 {
1556         struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
1557
1558         return fwspec ? fwspec->ops : NULL;
1559 }
1560
1561 static const struct iommu_ops *acpi_iommu_configure_id(struct device *dev,
1562                                                        const u32 *id_in)
1563 {
1564         int err;
1565         const struct iommu_ops *ops;
1566
1567         /*
1568          * If we already translated the fwspec there is nothing left to do,
1569          * return the iommu_ops.
1570          */
1571         ops = acpi_iommu_fwspec_ops(dev);
1572         if (ops)
1573                 return ops;
1574
1575         err = iort_iommu_configure_id(dev, id_in);
1576         if (err && err != -EPROBE_DEFER)
1577                 err = viot_iommu_configure(dev);
1578
1579         /*
1580          * If we have reason to believe the IOMMU driver missed the initial
1581          * iommu_probe_device() call for dev, replay it to get things in order.
1582          */
1583         if (!err && dev->bus && !device_iommu_mapped(dev))
1584                 err = iommu_probe_device(dev);
1585
1586         /* Ignore all other errors apart from EPROBE_DEFER */
1587         if (err == -EPROBE_DEFER) {
1588                 return ERR_PTR(err);
1589         } else if (err) {
1590                 dev_dbg(dev, "Adding to IOMMU failed: %d\n", err);
1591                 return NULL;
1592         }
1593         return acpi_iommu_fwspec_ops(dev);
1594 }
1595
1596 #else /* !CONFIG_IOMMU_API */
1597
1598 int acpi_iommu_fwspec_init(struct device *dev, u32 id,
1599                            struct fwnode_handle *fwnode,
1600                            const struct iommu_ops *ops)
1601 {
1602         return -ENODEV;
1603 }
1604
1605 static const struct iommu_ops *acpi_iommu_configure_id(struct device *dev,
1606                                                        const u32 *id_in)
1607 {
1608         return NULL;
1609 }
1610
1611 #endif /* !CONFIG_IOMMU_API */
1612
1613 /**
1614  * acpi_dma_configure_id - Set-up DMA configuration for the device.
1615  * @dev: The pointer to the device
1616  * @attr: device dma attributes
1617  * @input_id: input device id const value pointer
1618  */
1619 int acpi_dma_configure_id(struct device *dev, enum dev_dma_attr attr,
1620                           const u32 *input_id)
1621 {
1622         const struct iommu_ops *iommu;
1623         u64 dma_addr = 0, size = 0;
1624
1625         if (attr == DEV_DMA_NOT_SUPPORTED) {
1626                 set_dma_ops(dev, &dma_dummy_ops);
1627                 return 0;
1628         }
1629
1630         acpi_arch_dma_setup(dev, &dma_addr, &size);
1631
1632         iommu = acpi_iommu_configure_id(dev, input_id);
1633         if (PTR_ERR(iommu) == -EPROBE_DEFER)
1634                 return -EPROBE_DEFER;
1635
1636         arch_setup_dma_ops(dev, dma_addr, size,
1637                                 iommu, attr == DEV_DMA_COHERENT);
1638
1639         return 0;
1640 }
1641 EXPORT_SYMBOL_GPL(acpi_dma_configure_id);
1642
1643 static void acpi_init_coherency(struct acpi_device *adev)
1644 {
1645         unsigned long long cca = 0;
1646         acpi_status status;
1647         struct acpi_device *parent = acpi_dev_parent(adev);
1648
1649         if (parent && parent->flags.cca_seen) {
1650                 /*
1651                  * From ACPI spec, OSPM will ignore _CCA if an ancestor
1652                  * already saw one.
1653                  */
1654                 adev->flags.cca_seen = 1;
1655                 cca = parent->flags.coherent_dma;
1656         } else {
1657                 status = acpi_evaluate_integer(adev->handle, "_CCA",
1658                                                NULL, &cca);
1659                 if (ACPI_SUCCESS(status))
1660                         adev->flags.cca_seen = 1;
1661                 else if (!IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED))
1662                         /*
1663                          * If architecture does not specify that _CCA is
1664                          * required for DMA-able devices (e.g. x86),
1665                          * we default to _CCA=1.
1666                          */
1667                         cca = 1;
1668                 else
1669                         acpi_handle_debug(adev->handle,
1670                                           "ACPI device is missing _CCA.\n");
1671         }
1672
1673         adev->flags.coherent_dma = cca;
1674 }
1675
1676 static int acpi_check_serial_bus_slave(struct acpi_resource *ares, void *data)
1677 {
1678         bool *is_serial_bus_slave_p = data;
1679
1680         if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
1681                 return 1;
1682
1683         *is_serial_bus_slave_p = true;
1684
1685          /* no need to do more checking */
1686         return -1;
1687 }
1688
1689 static bool acpi_is_indirect_io_slave(struct acpi_device *device)
1690 {
1691         struct acpi_device *parent = acpi_dev_parent(device);
1692         static const struct acpi_device_id indirect_io_hosts[] = {
1693                 {"HISI0191", 0},
1694                 {}
1695         };
1696
1697         return parent && !acpi_match_device_ids(parent, indirect_io_hosts);
1698 }
1699
1700 static bool acpi_device_enumeration_by_parent(struct acpi_device *device)
1701 {
1702         struct list_head resource_list;
1703         bool is_serial_bus_slave = false;
1704         static const struct acpi_device_id ignore_serial_bus_ids[] = {
1705         /*
1706          * These devices have multiple SerialBus resources and a client
1707          * device must be instantiated for each of them, each with
1708          * its own device id.
1709          * Normally we only instantiate one client device for the first
1710          * resource, using the ACPI HID as id. These special cases are handled
1711          * by the drivers/platform/x86/serial-multi-instantiate.c driver, which
1712          * knows which client device id to use for each resource.
1713          */
1714                 {"BSG1160", },
1715                 {"BSG2150", },
1716                 {"CSC3551", },
1717                 {"INT33FE", },
1718                 {"INT3515", },
1719                 /* Non-conforming _HID for Cirrus Logic already released */
1720                 {"CLSA0100", },
1721                 {"CLSA0101", },
1722         /*
1723          * Some ACPI devs contain SerialBus resources even though they are not
1724          * attached to a serial bus at all.
1725          */
1726                 {"MSHW0028", },
1727         /*
1728          * HIDs of device with an UartSerialBusV2 resource for which userspace
1729          * expects a regular tty cdev to be created (instead of the in kernel
1730          * serdev) and which have a kernel driver which expects a platform_dev
1731          * such as the rfkill-gpio driver.
1732          */
1733                 {"BCM4752", },
1734                 {"LNV4752", },
1735                 {}
1736         };
1737
1738         if (acpi_is_indirect_io_slave(device))
1739                 return true;
1740
1741         /* Macs use device properties in lieu of _CRS resources */
1742         if (x86_apple_machine &&
1743             (fwnode_property_present(&device->fwnode, "spiSclkPeriod") ||
1744              fwnode_property_present(&device->fwnode, "i2cAddress") ||
1745              fwnode_property_present(&device->fwnode, "baud")))
1746                 return true;
1747
1748         if (!acpi_match_device_ids(device, ignore_serial_bus_ids))
1749                 return false;
1750
1751         INIT_LIST_HEAD(&resource_list);
1752         acpi_dev_get_resources(device, &resource_list,
1753                                acpi_check_serial_bus_slave,
1754                                &is_serial_bus_slave);
1755         acpi_dev_free_resource_list(&resource_list);
1756
1757         return is_serial_bus_slave;
1758 }
1759
1760 void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,
1761                              int type, void (*release)(struct device *))
1762 {
1763         struct acpi_device *parent = acpi_find_parent_acpi_dev(handle);
1764
1765         INIT_LIST_HEAD(&device->pnp.ids);
1766         device->device_type = type;
1767         device->handle = handle;
1768         device->dev.parent = parent ? &parent->dev : NULL;
1769         device->dev.release = release;
1770         device->dev.bus = &acpi_bus_type;
1771         fwnode_init(&device->fwnode, &acpi_device_fwnode_ops);
1772         acpi_set_device_status(device, ACPI_STA_DEFAULT);
1773         acpi_device_get_busid(device);
1774         acpi_set_pnp_ids(handle, &device->pnp, type);
1775         acpi_init_properties(device);
1776         acpi_bus_get_flags(device);
1777         device->flags.match_driver = false;
1778         device->flags.initialized = true;
1779         device->flags.enumeration_by_parent =
1780                 acpi_device_enumeration_by_parent(device);
1781         acpi_device_clear_enumerated(device);
1782         device_initialize(&device->dev);
1783         dev_set_uevent_suppress(&device->dev, true);
1784         acpi_init_coherency(device);
1785 }
1786
1787 static void acpi_scan_dep_init(struct acpi_device *adev)
1788 {
1789         struct acpi_dep_data *dep;
1790
1791         list_for_each_entry(dep, &acpi_dep_list, node) {
1792                 if (dep->consumer == adev->handle) {
1793                         if (dep->honor_dep)
1794                                 adev->flags.honor_deps = 1;
1795
1796                         adev->dep_unmet++;
1797                 }
1798         }
1799 }
1800
1801 void acpi_device_add_finalize(struct acpi_device *device)
1802 {
1803         dev_set_uevent_suppress(&device->dev, false);
1804         kobject_uevent(&device->dev.kobj, KOBJ_ADD);
1805 }
1806
1807 static void acpi_scan_init_status(struct acpi_device *adev)
1808 {
1809         if (acpi_bus_get_status(adev))
1810                 acpi_set_device_status(adev, 0);
1811 }
1812
1813 static int acpi_add_single_object(struct acpi_device **child,
1814                                   acpi_handle handle, int type, bool dep_init)
1815 {
1816         struct acpi_device *device;
1817         bool release_dep_lock = false;
1818         int result;
1819
1820         device = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
1821         if (!device)
1822                 return -ENOMEM;
1823
1824         acpi_init_device_object(device, handle, type, acpi_device_release);
1825         /*
1826          * Getting the status is delayed till here so that we can call
1827          * acpi_bus_get_status() and use its quirk handling.  Note that
1828          * this must be done before the get power-/wakeup_dev-flags calls.
1829          */
1830         if (type == ACPI_BUS_TYPE_DEVICE || type == ACPI_BUS_TYPE_PROCESSOR) {
1831                 if (dep_init) {
1832                         mutex_lock(&acpi_dep_list_lock);
1833                         /*
1834                          * Hold the lock until the acpi_tie_acpi_dev() call
1835                          * below to prevent concurrent acpi_scan_clear_dep()
1836                          * from deleting a dependency list entry without
1837                          * updating dep_unmet for the device.
1838                          */
1839                         release_dep_lock = true;
1840                         acpi_scan_dep_init(device);
1841                 }
1842                 acpi_scan_init_status(device);
1843         }
1844
1845         acpi_bus_get_power_flags(device);
1846         acpi_bus_get_wakeup_device_flags(device);
1847
1848         result = acpi_tie_acpi_dev(device);
1849
1850         if (release_dep_lock)
1851                 mutex_unlock(&acpi_dep_list_lock);
1852
1853         if (!result)
1854                 result = acpi_device_add(device);
1855
1856         if (result) {
1857                 acpi_device_release(&device->dev);
1858                 return result;
1859         }
1860
1861         acpi_power_add_remove_device(device, true);
1862         acpi_device_add_finalize(device);
1863
1864         acpi_handle_debug(handle, "Added as %s, parent %s\n",
1865                           dev_name(&device->dev), device->dev.parent ?
1866                                 dev_name(device->dev.parent) : "(null)");
1867
1868         *child = device;
1869         return 0;
1870 }
1871
1872 static acpi_status acpi_get_resource_memory(struct acpi_resource *ares,
1873                                             void *context)
1874 {
1875         struct resource *res = context;
1876
1877         if (acpi_dev_resource_memory(ares, res))
1878                 return AE_CTRL_TERMINATE;
1879
1880         return AE_OK;
1881 }
1882
1883 static bool acpi_device_should_be_hidden(acpi_handle handle)
1884 {
1885         acpi_status status;
1886         struct resource res;
1887
1888         /* Check if it should ignore the UART device */
1889         if (!(spcr_uart_addr && acpi_has_method(handle, METHOD_NAME__CRS)))
1890                 return false;
1891
1892         /*
1893          * The UART device described in SPCR table is assumed to have only one
1894          * memory resource present. So we only look for the first one here.
1895          */
1896         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1897                                      acpi_get_resource_memory, &res);
1898         if (ACPI_FAILURE(status) || res.start != spcr_uart_addr)
1899                 return false;
1900
1901         acpi_handle_info(handle, "The UART device @%pa in SPCR table will be hidden\n",
1902                          &res.start);
1903
1904         return true;
1905 }
1906
1907 bool acpi_device_is_present(const struct acpi_device *adev)
1908 {
1909         return adev->status.present || adev->status.functional;
1910 }
1911
1912 static bool acpi_scan_handler_matching(struct acpi_scan_handler *handler,
1913                                        const char *idstr,
1914                                        const struct acpi_device_id **matchid)
1915 {
1916         const struct acpi_device_id *devid;
1917
1918         if (handler->match)
1919                 return handler->match(idstr, matchid);
1920
1921         for (devid = handler->ids; devid->id[0]; devid++)
1922                 if (!strcmp((char *)devid->id, idstr)) {
1923                         if (matchid)
1924                                 *matchid = devid;
1925
1926                         return true;
1927                 }
1928
1929         return false;
1930 }
1931
1932 static struct acpi_scan_handler *acpi_scan_match_handler(const char *idstr,
1933                                         const struct acpi_device_id **matchid)
1934 {
1935         struct acpi_scan_handler *handler;
1936
1937         list_for_each_entry(handler, &acpi_scan_handlers_list, list_node)
1938                 if (acpi_scan_handler_matching(handler, idstr, matchid))
1939                         return handler;
1940
1941         return NULL;
1942 }
1943
1944 void acpi_scan_hotplug_enabled(struct acpi_hotplug_profile *hotplug, bool val)
1945 {
1946         if (!!hotplug->enabled == !!val)
1947                 return;
1948
1949         mutex_lock(&acpi_scan_lock);
1950
1951         hotplug->enabled = val;
1952
1953         mutex_unlock(&acpi_scan_lock);
1954 }
1955
1956 static void acpi_scan_init_hotplug(struct acpi_device *adev)
1957 {
1958         struct acpi_hardware_id *hwid;
1959
1960         if (acpi_dock_match(adev->handle) || is_ejectable_bay(adev)) {
1961                 acpi_dock_add(adev);
1962                 return;
1963         }
1964         list_for_each_entry(hwid, &adev->pnp.ids, list) {
1965                 struct acpi_scan_handler *handler;
1966
1967                 handler = acpi_scan_match_handler(hwid->id, NULL);
1968                 if (handler) {
1969                         adev->flags.hotplug_notify = true;
1970                         break;
1971                 }
1972         }
1973 }
1974
1975 static u32 acpi_scan_check_dep(acpi_handle handle, bool check_dep)
1976 {
1977         struct acpi_handle_list dep_devices;
1978         acpi_status status;
1979         u32 count;
1980         int i;
1981
1982         /*
1983          * Check for _HID here to avoid deferring the enumeration of:
1984          * 1. PCI devices.
1985          * 2. ACPI nodes describing USB ports.
1986          * Still, checking for _HID catches more then just these cases ...
1987          */
1988         if (!check_dep || !acpi_has_method(handle, "_DEP") ||
1989             !acpi_has_method(handle, "_HID"))
1990                 return 0;
1991
1992         status = acpi_evaluate_reference(handle, "_DEP", NULL, &dep_devices);
1993         if (ACPI_FAILURE(status)) {
1994                 acpi_handle_debug(handle, "Failed to evaluate _DEP.\n");
1995                 return 0;
1996         }
1997
1998         for (count = 0, i = 0; i < dep_devices.count; i++) {
1999                 struct acpi_device_info *info;
2000                 struct acpi_dep_data *dep;
2001                 bool skip, honor_dep;
2002
2003                 status = acpi_get_object_info(dep_devices.handles[i], &info);
2004                 if (ACPI_FAILURE(status)) {
2005                         acpi_handle_debug(handle, "Error reading _DEP device info\n");
2006                         continue;
2007                 }
2008
2009                 skip = acpi_info_matches_ids(info, acpi_ignore_dep_ids);
2010                 honor_dep = acpi_info_matches_ids(info, acpi_honor_dep_ids);
2011                 kfree(info);
2012
2013                 if (skip)
2014                         continue;
2015
2016                 dep = kzalloc(sizeof(*dep), GFP_KERNEL);
2017                 if (!dep)
2018                         continue;
2019
2020                 count++;
2021
2022                 dep->supplier = dep_devices.handles[i];
2023                 dep->consumer = handle;
2024                 dep->honor_dep = honor_dep;
2025
2026                 mutex_lock(&acpi_dep_list_lock);
2027                 list_add_tail(&dep->node , &acpi_dep_list);
2028                 mutex_unlock(&acpi_dep_list_lock);
2029         }
2030
2031         return count;
2032 }
2033
2034 static bool acpi_bus_scan_second_pass;
2035
2036 static acpi_status acpi_bus_check_add(acpi_handle handle, bool check_dep,
2037                                       struct acpi_device **adev_p)
2038 {
2039         struct acpi_device *device = acpi_fetch_acpi_dev(handle);
2040         acpi_object_type acpi_type;
2041         int type;
2042
2043         if (device)
2044                 goto out;
2045
2046         if (ACPI_FAILURE(acpi_get_type(handle, &acpi_type)))
2047                 return AE_OK;
2048
2049         switch (acpi_type) {
2050         case ACPI_TYPE_DEVICE:
2051                 if (acpi_device_should_be_hidden(handle))
2052                         return AE_OK;
2053
2054                 /* Bail out if there are dependencies. */
2055                 if (acpi_scan_check_dep(handle, check_dep) > 0) {
2056                         acpi_bus_scan_second_pass = true;
2057                         return AE_CTRL_DEPTH;
2058                 }
2059
2060                 fallthrough;
2061         case ACPI_TYPE_ANY:     /* for ACPI_ROOT_OBJECT */
2062                 type = ACPI_BUS_TYPE_DEVICE;
2063                 break;
2064
2065         case ACPI_TYPE_PROCESSOR:
2066                 type = ACPI_BUS_TYPE_PROCESSOR;
2067                 break;
2068
2069         case ACPI_TYPE_THERMAL:
2070                 type = ACPI_BUS_TYPE_THERMAL;
2071                 break;
2072
2073         case ACPI_TYPE_POWER:
2074                 acpi_add_power_resource(handle);
2075                 fallthrough;
2076         default:
2077                 return AE_OK;
2078         }
2079
2080         /*
2081          * If check_dep is true at this point, the device has no dependencies,
2082          * or the creation of the device object would have been postponed above.
2083          */
2084         acpi_add_single_object(&device, handle, type, !check_dep);
2085         if (!device)
2086                 return AE_CTRL_DEPTH;
2087
2088         acpi_scan_init_hotplug(device);
2089
2090 out:
2091         if (!*adev_p)
2092                 *adev_p = device;
2093
2094         return AE_OK;
2095 }
2096
2097 static acpi_status acpi_bus_check_add_1(acpi_handle handle, u32 lvl_not_used,
2098                                         void *not_used, void **ret_p)
2099 {
2100         return acpi_bus_check_add(handle, true, (struct acpi_device **)ret_p);
2101 }
2102
2103 static acpi_status acpi_bus_check_add_2(acpi_handle handle, u32 lvl_not_used,
2104                                         void *not_used, void **ret_p)
2105 {
2106         return acpi_bus_check_add(handle, false, (struct acpi_device **)ret_p);
2107 }
2108
2109 static void acpi_default_enumeration(struct acpi_device *device)
2110 {
2111         /*
2112          * Do not enumerate devices with enumeration_by_parent flag set as
2113          * they will be enumerated by their respective parents.
2114          */
2115         if (!device->flags.enumeration_by_parent) {
2116                 acpi_create_platform_device(device, NULL);
2117                 acpi_device_set_enumerated(device);
2118         } else {
2119                 blocking_notifier_call_chain(&acpi_reconfig_chain,
2120                                              ACPI_RECONFIG_DEVICE_ADD, device);
2121         }
2122 }
2123
2124 static const struct acpi_device_id generic_device_ids[] = {
2125         {ACPI_DT_NAMESPACE_HID, },
2126         {"", },
2127 };
2128
2129 static int acpi_generic_device_attach(struct acpi_device *adev,
2130                                       const struct acpi_device_id *not_used)
2131 {
2132         /*
2133          * Since ACPI_DT_NAMESPACE_HID is the only ID handled here, the test
2134          * below can be unconditional.
2135          */
2136         if (adev->data.of_compatible)
2137                 acpi_default_enumeration(adev);
2138
2139         return 1;
2140 }
2141
2142 static struct acpi_scan_handler generic_device_handler = {
2143         .ids = generic_device_ids,
2144         .attach = acpi_generic_device_attach,
2145 };
2146
2147 static int acpi_scan_attach_handler(struct acpi_device *device)
2148 {
2149         struct acpi_hardware_id *hwid;
2150         int ret = 0;
2151
2152         list_for_each_entry(hwid, &device->pnp.ids, list) {
2153                 const struct acpi_device_id *devid;
2154                 struct acpi_scan_handler *handler;
2155
2156                 handler = acpi_scan_match_handler(hwid->id, &devid);
2157                 if (handler) {
2158                         if (!handler->attach) {
2159                                 device->pnp.type.platform_id = 0;
2160                                 continue;
2161                         }
2162                         device->handler = handler;
2163                         ret = handler->attach(device, devid);
2164                         if (ret > 0)
2165                                 break;
2166
2167                         device->handler = NULL;
2168                         if (ret < 0)
2169                                 break;
2170                 }
2171         }
2172
2173         return ret;
2174 }
2175
2176 static int acpi_bus_attach(struct acpi_device *device, void *first_pass)
2177 {
2178         bool skip = !first_pass && device->flags.visited;
2179         acpi_handle ejd;
2180         int ret;
2181
2182         if (skip)
2183                 goto ok;
2184
2185         if (ACPI_SUCCESS(acpi_bus_get_ejd(device->handle, &ejd)))
2186                 register_dock_dependent_device(device, ejd);
2187
2188         acpi_bus_get_status(device);
2189         /* Skip devices that are not ready for enumeration (e.g. not present) */
2190         if (!acpi_dev_ready_for_enumeration(device)) {
2191                 device->flags.initialized = false;
2192                 acpi_device_clear_enumerated(device);
2193                 device->flags.power_manageable = 0;
2194                 return 0;
2195         }
2196         if (device->handler)
2197                 goto ok;
2198
2199         if (!device->flags.initialized) {
2200                 device->flags.power_manageable =
2201                         device->power.states[ACPI_STATE_D0].flags.valid;
2202                 if (acpi_bus_init_power(device))
2203                         device->flags.power_manageable = 0;
2204
2205                 device->flags.initialized = true;
2206         } else if (device->flags.visited) {
2207                 goto ok;
2208         }
2209
2210         ret = acpi_scan_attach_handler(device);
2211         if (ret < 0)
2212                 return 0;
2213
2214         device->flags.match_driver = true;
2215         if (ret > 0 && !device->flags.enumeration_by_parent) {
2216                 acpi_device_set_enumerated(device);
2217                 goto ok;
2218         }
2219
2220         ret = device_attach(&device->dev);
2221         if (ret < 0)
2222                 return 0;
2223
2224         if (device->pnp.type.platform_id || device->flags.enumeration_by_parent)
2225                 acpi_default_enumeration(device);
2226         else
2227                 acpi_device_set_enumerated(device);
2228
2229 ok:
2230         acpi_dev_for_each_child(device, acpi_bus_attach, first_pass);
2231
2232         if (!skip && device->handler && device->handler->hotplug.notify_online)
2233                 device->handler->hotplug.notify_online(device);
2234
2235         return 0;
2236 }
2237
2238 static int acpi_dev_get_next_consumer_dev_cb(struct acpi_dep_data *dep, void *data)
2239 {
2240         struct acpi_device **adev_p = data;
2241         struct acpi_device *adev = *adev_p;
2242
2243         /*
2244          * If we're passed a 'previous' consumer device then we need to skip
2245          * any consumers until we meet the previous one, and then NULL @data
2246          * so the next one can be returned.
2247          */
2248         if (adev) {
2249                 if (dep->consumer == adev->handle)
2250                         *adev_p = NULL;
2251
2252                 return 0;
2253         }
2254
2255         adev = acpi_get_acpi_dev(dep->consumer);
2256         if (adev) {
2257                 *(struct acpi_device **)data = adev;
2258                 return 1;
2259         }
2260         /* Continue parsing if the device object is not present. */
2261         return 0;
2262 }
2263
2264 struct acpi_scan_clear_dep_work {
2265         struct work_struct work;
2266         struct acpi_device *adev;
2267 };
2268
2269 static void acpi_scan_clear_dep_fn(struct work_struct *work)
2270 {
2271         struct acpi_scan_clear_dep_work *cdw;
2272
2273         cdw = container_of(work, struct acpi_scan_clear_dep_work, work);
2274
2275         acpi_scan_lock_acquire();
2276         acpi_bus_attach(cdw->adev, (void *)true);
2277         acpi_scan_lock_release();
2278
2279         acpi_dev_put(cdw->adev);
2280         kfree(cdw);
2281 }
2282
2283 static bool acpi_scan_clear_dep_queue(struct acpi_device *adev)
2284 {
2285         struct acpi_scan_clear_dep_work *cdw;
2286
2287         if (adev->dep_unmet)
2288                 return false;
2289
2290         cdw = kmalloc(sizeof(*cdw), GFP_KERNEL);
2291         if (!cdw)
2292                 return false;
2293
2294         cdw->adev = adev;
2295         INIT_WORK(&cdw->work, acpi_scan_clear_dep_fn);
2296         /*
2297          * Since the work function may block on the lock until the entire
2298          * initial enumeration of devices is complete, put it into the unbound
2299          * workqueue.
2300          */
2301         queue_work(system_unbound_wq, &cdw->work);
2302
2303         return true;
2304 }
2305
2306 static int acpi_scan_clear_dep(struct acpi_dep_data *dep, void *data)
2307 {
2308         struct acpi_device *adev = acpi_get_acpi_dev(dep->consumer);
2309
2310         if (adev) {
2311                 adev->dep_unmet--;
2312                 if (!acpi_scan_clear_dep_queue(adev))
2313                         acpi_dev_put(adev);
2314         }
2315
2316         list_del(&dep->node);
2317         kfree(dep);
2318
2319         return 0;
2320 }
2321
2322 /**
2323  * acpi_walk_dep_device_list - Apply a callback to every entry in acpi_dep_list
2324  * @handle:     The ACPI handle of the supplier device
2325  * @callback:   Pointer to the callback function to apply
2326  * @data:       Pointer to some data to pass to the callback
2327  *
2328  * The return value of the callback determines this function's behaviour. If 0
2329  * is returned we continue to iterate over acpi_dep_list. If a positive value
2330  * is returned then the loop is broken but this function returns 0. If a
2331  * negative value is returned by the callback then the loop is broken and that
2332  * value is returned as the final error.
2333  */
2334 static int acpi_walk_dep_device_list(acpi_handle handle,
2335                                 int (*callback)(struct acpi_dep_data *, void *),
2336                                 void *data)
2337 {
2338         struct acpi_dep_data *dep, *tmp;
2339         int ret = 0;
2340
2341         mutex_lock(&acpi_dep_list_lock);
2342         list_for_each_entry_safe(dep, tmp, &acpi_dep_list, node) {
2343                 if (dep->supplier == handle) {
2344                         ret = callback(dep, data);
2345                         if (ret)
2346                                 break;
2347                 }
2348         }
2349         mutex_unlock(&acpi_dep_list_lock);
2350
2351         return ret > 0 ? 0 : ret;
2352 }
2353
2354 /**
2355  * acpi_dev_clear_dependencies - Inform consumers that the device is now active
2356  * @supplier: Pointer to the supplier &struct acpi_device
2357  *
2358  * Clear dependencies on the given device.
2359  */
2360 void acpi_dev_clear_dependencies(struct acpi_device *supplier)
2361 {
2362         acpi_walk_dep_device_list(supplier->handle, acpi_scan_clear_dep, NULL);
2363 }
2364 EXPORT_SYMBOL_GPL(acpi_dev_clear_dependencies);
2365
2366 /**
2367  * acpi_dev_ready_for_enumeration - Check if the ACPI device is ready for enumeration
2368  * @device: Pointer to the &struct acpi_device to check
2369  *
2370  * Check if the device is present and has no unmet dependencies.
2371  *
2372  * Return true if the device is ready for enumeratino. Otherwise, return false.
2373  */
2374 bool acpi_dev_ready_for_enumeration(const struct acpi_device *device)
2375 {
2376         if (device->flags.honor_deps && device->dep_unmet)
2377                 return false;
2378
2379         return acpi_device_is_present(device);
2380 }
2381 EXPORT_SYMBOL_GPL(acpi_dev_ready_for_enumeration);
2382
2383 /**
2384  * acpi_dev_get_next_consumer_dev - Return the next adev dependent on @supplier
2385  * @supplier: Pointer to the dependee device
2386  * @start: Pointer to the current dependent device
2387  *
2388  * Returns the next &struct acpi_device which declares itself dependent on
2389  * @supplier via the _DEP buffer, parsed from the acpi_dep_list.
2390  *
2391  * If the returned adev is not passed as @start to this function, the caller is
2392  * responsible for putting the reference to adev when it is no longer needed.
2393  */
2394 struct acpi_device *acpi_dev_get_next_consumer_dev(struct acpi_device *supplier,
2395                                                    struct acpi_device *start)
2396 {
2397         struct acpi_device *adev = start;
2398
2399         acpi_walk_dep_device_list(supplier->handle,
2400                                   acpi_dev_get_next_consumer_dev_cb, &adev);
2401
2402         acpi_dev_put(start);
2403
2404         if (adev == start)
2405                 return NULL;
2406
2407         return adev;
2408 }
2409 EXPORT_SYMBOL_GPL(acpi_dev_get_next_consumer_dev);
2410
2411 /**
2412  * acpi_bus_scan - Add ACPI device node objects in a given namespace scope.
2413  * @handle: Root of the namespace scope to scan.
2414  *
2415  * Scan a given ACPI tree (probably recently hot-plugged) and create and add
2416  * found devices.
2417  *
2418  * If no devices were found, -ENODEV is returned, but it does not mean that
2419  * there has been a real error.  There just have been no suitable ACPI objects
2420  * in the table trunk from which the kernel could create a device and add an
2421  * appropriate driver.
2422  *
2423  * Must be called under acpi_scan_lock.
2424  */
2425 int acpi_bus_scan(acpi_handle handle)
2426 {
2427         struct acpi_device *device = NULL;
2428
2429         acpi_bus_scan_second_pass = false;
2430
2431         /* Pass 1: Avoid enumerating devices with missing dependencies. */
2432
2433         if (ACPI_SUCCESS(acpi_bus_check_add(handle, true, &device)))
2434                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
2435                                     acpi_bus_check_add_1, NULL, NULL,
2436                                     (void **)&device);
2437
2438         if (!device)
2439                 return -ENODEV;
2440
2441         acpi_bus_attach(device, (void *)true);
2442
2443         if (!acpi_bus_scan_second_pass)
2444                 return 0;
2445
2446         /* Pass 2: Enumerate all of the remaining devices. */
2447
2448         device = NULL;
2449
2450         if (ACPI_SUCCESS(acpi_bus_check_add(handle, false, &device)))
2451                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
2452                                     acpi_bus_check_add_2, NULL, NULL,
2453                                     (void **)&device);
2454
2455         acpi_bus_attach(device, NULL);
2456
2457         return 0;
2458 }
2459 EXPORT_SYMBOL(acpi_bus_scan);
2460
2461 static int acpi_bus_trim_one(struct acpi_device *adev, void *not_used)
2462 {
2463         struct acpi_scan_handler *handler = adev->handler;
2464
2465         acpi_dev_for_each_child_reverse(adev, acpi_bus_trim_one, NULL);
2466
2467         adev->flags.match_driver = false;
2468         if (handler) {
2469                 if (handler->detach)
2470                         handler->detach(adev);
2471
2472                 adev->handler = NULL;
2473         } else {
2474                 device_release_driver(&adev->dev);
2475         }
2476         /*
2477          * Most likely, the device is going away, so put it into D3cold before
2478          * that.
2479          */
2480         acpi_device_set_power(adev, ACPI_STATE_D3_COLD);
2481         adev->flags.initialized = false;
2482         acpi_device_clear_enumerated(adev);
2483
2484         return 0;
2485 }
2486
2487 /**
2488  * acpi_bus_trim - Detach scan handlers and drivers from ACPI device objects.
2489  * @adev: Root of the ACPI namespace scope to walk.
2490  *
2491  * Must be called under acpi_scan_lock.
2492  */
2493 void acpi_bus_trim(struct acpi_device *adev)
2494 {
2495         acpi_bus_trim_one(adev, NULL);
2496 }
2497 EXPORT_SYMBOL_GPL(acpi_bus_trim);
2498
2499 int acpi_bus_register_early_device(int type)
2500 {
2501         struct acpi_device *device = NULL;
2502         int result;
2503
2504         result = acpi_add_single_object(&device, NULL, type, false);
2505         if (result)
2506                 return result;
2507
2508         device->flags.match_driver = true;
2509         return device_attach(&device->dev);
2510 }
2511 EXPORT_SYMBOL_GPL(acpi_bus_register_early_device);
2512
2513 static void acpi_bus_scan_fixed(void)
2514 {
2515         if (!(acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON)) {
2516                 struct acpi_device *adev = NULL;
2517
2518                 acpi_add_single_object(&adev, NULL, ACPI_BUS_TYPE_POWER_BUTTON,
2519                                        false);
2520                 if (adev) {
2521                         adev->flags.match_driver = true;
2522                         if (device_attach(&adev->dev) >= 0)
2523                                 device_init_wakeup(&adev->dev, true);
2524                         else
2525                                 dev_dbg(&adev->dev, "No driver\n");
2526                 }
2527         }
2528
2529         if (!(acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON)) {
2530                 struct acpi_device *adev = NULL;
2531
2532                 acpi_add_single_object(&adev, NULL, ACPI_BUS_TYPE_SLEEP_BUTTON,
2533                                        false);
2534                 if (adev) {
2535                         adev->flags.match_driver = true;
2536                         if (device_attach(&adev->dev) < 0)
2537                                 dev_dbg(&adev->dev, "No driver\n");
2538                 }
2539         }
2540 }
2541
2542 static void __init acpi_get_spcr_uart_addr(void)
2543 {
2544         acpi_status status;
2545         struct acpi_table_spcr *spcr_ptr;
2546
2547         status = acpi_get_table(ACPI_SIG_SPCR, 0,
2548                                 (struct acpi_table_header **)&spcr_ptr);
2549         if (ACPI_FAILURE(status)) {
2550                 pr_warn("STAO table present, but SPCR is missing\n");
2551                 return;
2552         }
2553
2554         spcr_uart_addr = spcr_ptr->serial_port.address;
2555         acpi_put_table((struct acpi_table_header *)spcr_ptr);
2556 }
2557
2558 static bool acpi_scan_initialized;
2559
2560 void __init acpi_scan_init(void)
2561 {
2562         acpi_status status;
2563         struct acpi_table_stao *stao_ptr;
2564
2565         acpi_pci_root_init();
2566         acpi_pci_link_init();
2567         acpi_processor_init();
2568         acpi_platform_init();
2569         acpi_lpss_init();
2570         acpi_apd_init();
2571         acpi_cmos_rtc_init();
2572         acpi_container_init();
2573         acpi_memory_hotplug_init();
2574         acpi_watchdog_init();
2575         acpi_pnp_init();
2576         acpi_int340x_thermal_init();
2577         acpi_amba_init();
2578         acpi_init_lpit();
2579
2580         acpi_scan_add_handler(&generic_device_handler);
2581
2582         /*
2583          * If there is STAO table, check whether it needs to ignore the UART
2584          * device in SPCR table.
2585          */
2586         status = acpi_get_table(ACPI_SIG_STAO, 0,
2587                                 (struct acpi_table_header **)&stao_ptr);
2588         if (ACPI_SUCCESS(status)) {
2589                 if (stao_ptr->header.length > sizeof(struct acpi_table_stao))
2590                         pr_info("STAO Name List not yet supported.\n");
2591
2592                 if (stao_ptr->ignore_uart)
2593                         acpi_get_spcr_uart_addr();
2594
2595                 acpi_put_table((struct acpi_table_header *)stao_ptr);
2596         }
2597
2598         acpi_gpe_apply_masked_gpes();
2599         acpi_update_all_gpes();
2600
2601         /*
2602          * Although we call __add_memory() that is documented to require the
2603          * device_hotplug_lock, it is not necessary here because this is an
2604          * early code when userspace or any other code path cannot trigger
2605          * hotplug/hotunplug operations.
2606          */
2607         mutex_lock(&acpi_scan_lock);
2608         /*
2609          * Enumerate devices in the ACPI namespace.
2610          */
2611         if (acpi_bus_scan(ACPI_ROOT_OBJECT))
2612                 goto unlock;
2613
2614         acpi_root = acpi_fetch_acpi_dev(ACPI_ROOT_OBJECT);
2615         if (!acpi_root)
2616                 goto unlock;
2617
2618         /* Fixed feature devices do not exist on HW-reduced platform */
2619         if (!acpi_gbl_reduced_hardware)
2620                 acpi_bus_scan_fixed();
2621
2622         acpi_turn_off_unused_power_resources();
2623
2624         acpi_scan_initialized = true;
2625
2626 unlock:
2627         mutex_unlock(&acpi_scan_lock);
2628 }
2629
2630 static struct acpi_probe_entry *ape;
2631 static int acpi_probe_count;
2632 static DEFINE_MUTEX(acpi_probe_mutex);
2633
2634 static int __init acpi_match_madt(union acpi_subtable_headers *header,
2635                                   const unsigned long end)
2636 {
2637         if (!ape->subtable_valid || ape->subtable_valid(&header->common, ape))
2638                 if (!ape->probe_subtbl(header, end))
2639                         acpi_probe_count++;
2640
2641         return 0;
2642 }
2643
2644 int __init __acpi_probe_device_table(struct acpi_probe_entry *ap_head, int nr)
2645 {
2646         int count = 0;
2647
2648         if (acpi_disabled)
2649                 return 0;
2650
2651         mutex_lock(&acpi_probe_mutex);
2652         for (ape = ap_head; nr; ape++, nr--) {
2653                 if (ACPI_COMPARE_NAMESEG(ACPI_SIG_MADT, ape->id)) {
2654                         acpi_probe_count = 0;
2655                         acpi_table_parse_madt(ape->type, acpi_match_madt, 0);
2656                         count += acpi_probe_count;
2657                 } else {
2658                         int res;
2659                         res = acpi_table_parse(ape->id, ape->probe_table);
2660                         if (!res)
2661                                 count++;
2662                 }
2663         }
2664         mutex_unlock(&acpi_probe_mutex);
2665
2666         return count;
2667 }
2668
2669 static void acpi_table_events_fn(struct work_struct *work)
2670 {
2671         acpi_scan_lock_acquire();
2672         acpi_bus_scan(ACPI_ROOT_OBJECT);
2673         acpi_scan_lock_release();
2674
2675         kfree(work);
2676 }
2677
2678 void acpi_scan_table_notify(void)
2679 {
2680         struct work_struct *work;
2681
2682         if (!acpi_scan_initialized)
2683                 return;
2684
2685         work = kmalloc(sizeof(*work), GFP_KERNEL);
2686         if (!work)
2687                 return;
2688
2689         INIT_WORK(work, acpi_table_events_fn);
2690         schedule_work(work);
2691 }
2692
2693 int acpi_reconfig_notifier_register(struct notifier_block *nb)
2694 {
2695         return blocking_notifier_chain_register(&acpi_reconfig_chain, nb);
2696 }
2697 EXPORT_SYMBOL(acpi_reconfig_notifier_register);
2698
2699 int acpi_reconfig_notifier_unregister(struct notifier_block *nb)
2700 {
2701         return blocking_notifier_chain_unregister(&acpi_reconfig_chain, nb);
2702 }
2703 EXPORT_SYMBOL(acpi_reconfig_notifier_unregister);