drivers/acpi/scan.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * scan.c - support for transforming the ACPI namespace into individual objects
   4  */
   5
   6 #define pr_fmt(fmt) "ACPI: " fmt
   7
   8 #include <linux/module.h>
   9 #include <linux/init.h>
  10 #include <linux/slab.h>
  11 #include <linux/kernel.h>
  12 #include <linux/acpi.h>
  13 #include <linux/acpi_iort.h>
  14 #include <linux/acpi_viot.h>
  15 #include <linux/iommu.h>
  16 #include <linux/signal.h>
  17 #include <linux/kthread.h>
  18 #include <linux/dmi.h>
  19 #include <linux/dma-map-ops.h>
  20 #include <linux/platform_data/x86/apple.h>
  21 #include <linux/pgtable.h>
  22 #include <linux/crc32.h>
  23
  24 #include "internal.h"
  25
  26 extern struct acpi_device *acpi_root;
  27
  28 #define ACPI_BUS_CLASS                  "system_bus"
  29 #define ACPI_BUS_HID                    "LNXSYBUS"
  30 #define ACPI_BUS_DEVICE_NAME            "System Bus"
  31
  32 #define ACPI_IS_ROOT_DEVICE(device)    (!(device)->parent)
  33
  34 #define INVALID_ACPI_HANDLE     ((acpi_handle)empty_zero_page)
  35
  36 static const char *dummy_hid = "device";
  37
  38 static LIST_HEAD(acpi_dep_list);
  39 static DEFINE_MUTEX(acpi_dep_list_lock);
  40 LIST_HEAD(acpi_bus_id_list);
  41 static DEFINE_MUTEX(acpi_scan_lock);
  42 static LIST_HEAD(acpi_scan_handlers_list);
  43 DEFINE_MUTEX(acpi_device_lock);
  44 LIST_HEAD(acpi_wakeup_device_list);
  45 static DEFINE_MUTEX(acpi_hp_context_lock);
  46
  47 /*
  48  * The UART device described by the SPCR table is the only object which needs
  49  * special-casing. Everything else is covered by ACPI namespace paths in STAO
  50  * table.
  51  */
  52 static u64 spcr_uart_addr;
  53
  54 void acpi_scan_lock_acquire(void)
  55 {
  56         mutex_lock(&acpi_scan_lock);
  57 }
  58 EXPORT_SYMBOL_GPL(acpi_scan_lock_acquire);
  59
  60 void acpi_scan_lock_release(void)
  61 {
  62         mutex_unlock(&acpi_scan_lock);
  63 }
  64 EXPORT_SYMBOL_GPL(acpi_scan_lock_release);
  65
  66 void acpi_lock_hp_context(void)
  67 {
  68         mutex_lock(&acpi_hp_context_lock);
  69 }
  70
  71 void acpi_unlock_hp_context(void)
  72 {
  73         mutex_unlock(&acpi_hp_context_lock);
  74 }
  75
  76 void acpi_initialize_hp_context(struct acpi_device *adev,
  77                                 struct acpi_hotplug_context *hp,
  78                                 int (*notify)(struct acpi_device *, u32),
  79                                 void (*uevent)(struct acpi_device *, u32))
  80 {
  81         acpi_lock_hp_context();
  82         hp->notify = notify;
  83         hp->uevent = uevent;
  84         acpi_set_hp_context(adev, hp);
  85         acpi_unlock_hp_context();
  86 }
  87 EXPORT_SYMBOL_GPL(acpi_initialize_hp_context);
  88
  89 int acpi_scan_add_handler(struct acpi_scan_handler *handler)
  90 {
  91         if (!handler)
  92                 return -EINVAL;
  93
  94         list_add_tail(&handler->list_node, &acpi_scan_handlers_list);
  95         return 0;
  96 }
  97
  98 int acpi_scan_add_handler_with_hotplug(struct acpi_scan_handler *handler,
  99                                        const char *hotplug_profile_name)
 100 {
 101         int error;
 102
 103         error = acpi_scan_add_handler(handler);
 104         if (error)
 105                 return error;
 106
 107         acpi_sysfs_add_hotplug_profile(&handler->hotplug, hotplug_profile_name);
 108         return 0;
 109 }
 110
 111 bool acpi_scan_is_offline(struct acpi_device *adev, bool uevent)
 112 {
 113         struct acpi_device_physical_node *pn;
 114         bool offline = true;
 115         char *envp[] = { "EVENT=offline", NULL };
 116
 117         /*
 118          * acpi_container_offline() calls this for all of the container's
 119          * children under the container's physical_node_lock lock.
 120          */
 121         mutex_lock_nested(&adev->physical_node_lock, SINGLE_DEPTH_NESTING);
 122
 123         list_for_each_entry(pn, &adev->physical_node_list, node)
 124                 if (device_supports_offline(pn->dev) && !pn->dev->offline) {
 125                         if (uevent)
 126                                 kobject_uevent_env(&pn->dev->kobj, KOBJ_CHANGE, envp);
 127
 128                         offline = false;
 129                         break;
 130                 }
 131
 132         mutex_unlock(&adev->physical_node_lock);
 133         return offline;
 134 }
 135
 136 static acpi_status acpi_bus_offline(acpi_handle handle, u32 lvl, void *data,
 137                                     void **ret_p)
 138 {
 139         struct acpi_device *device = acpi_fetch_acpi_dev(handle);
 140         struct acpi_device_physical_node *pn;
 141         bool second_pass = (bool)data;
 142         acpi_status status = AE_OK;
 143
 144         if (!device)
 145                 return AE_OK;
 146
 147         if (device->handler && !device->handler->hotplug.enabled) {
 148                 *ret_p = &device->dev;
 149                 return AE_SUPPORT;
 150         }
 151
 152         mutex_lock(&device->physical_node_lock);
 153
 154         list_for_each_entry(pn, &device->physical_node_list, node) {
 155                 int ret;
 156
 157                 if (second_pass) {
 158                         /* Skip devices offlined by the first pass. */
 159                         if (pn->put_online)
 160                                 continue;
 161                 } else {
 162                         pn->put_online = false;
 163                 }
 164                 ret = device_offline(pn->dev);
 165                 if (ret >= 0) {
 166                         pn->put_online = !ret;
 167                 } else {
 168                         *ret_p = pn->dev;
 169                         if (second_pass) {
 170                                 status = AE_ERROR;
 171                                 break;
 172                         }
 173                 }
 174         }
 175
 176         mutex_unlock(&device->physical_node_lock);
 177
 178         return status;
 179 }
 180
 181 static acpi_status acpi_bus_online(acpi_handle handle, u32 lvl, void *data,
 182                                    void **ret_p)
 183 {
 184         struct acpi_device *device = acpi_fetch_acpi_dev(handle);
 185         struct acpi_device_physical_node *pn;
 186
 187         if (!device)
 188                 return AE_OK;
 189
 190         mutex_lock(&device->physical_node_lock);
 191
 192         list_for_each_entry(pn, &device->physical_node_list, node)
 193                 if (pn->put_online) {
 194                         device_online(pn->dev);
 195                         pn->put_online = false;
 196                 }
 197
 198         mutex_unlock(&device->physical_node_lock);
 199
 200         return AE_OK;
 201 }
 202
 203 static int acpi_scan_try_to_offline(struct acpi_device *device)
 204 {
 205         acpi_handle handle = device->handle;
 206         struct device *errdev = NULL;
 207         acpi_status status;
 208
 209         /*
 210          * Carry out two passes here and ignore errors in the first pass,
 211          * because if the devices in question are memory blocks and
 212          * CONFIG_MEMCG is set, one of the blocks may hold data structures
 213          * that the other blocks depend on, but it is not known in advance which
 214          * block holds them.
 215          *
 216          * If the first pass is successful, the second one isn't needed, though.
 217          */
 218         status = acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
 219                                      NULL, acpi_bus_offline, (void *)false,
 220                                      (void **)&errdev);
 221         if (status == AE_SUPPORT) {
 222                 dev_warn(errdev, "Offline disabled.\n");
 223                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
 224                                     acpi_bus_online, NULL, NULL, NULL);
 225                 return -EPERM;
 226         }
 227         acpi_bus_offline(handle, 0, (void *)false, (void **)&errdev);
 228         if (errdev) {
 229                 errdev = NULL;
 230                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
 231                                     NULL, acpi_bus_offline, (void *)true,
 232                                     (void **)&errdev);
 233                 if (!errdev)
 234                         acpi_bus_offline(handle, 0, (void *)true,
 235                                          (void **)&errdev);
 236
 237                 if (errdev) {
 238                         dev_warn(errdev, "Offline failed.\n");
 239                         acpi_bus_online(handle, 0, NULL, NULL);
 240                         acpi_walk_namespace(ACPI_TYPE_ANY, handle,
 241                                             ACPI_UINT32_MAX, acpi_bus_online,
 242                                             NULL, NULL, NULL);
 243                         return -EBUSY;
 244                 }
 245         }
 246         return 0;
 247 }
 248
 249 static int acpi_scan_hot_remove(struct acpi_device *device)
 250 {
 251         acpi_handle handle = device->handle;
 252         unsigned long long sta;
 253         acpi_status status;
 254
 255         if (device->handler && device->handler->hotplug.demand_offline) {
 256                 if (!acpi_scan_is_offline(device, true))
 257                         return -EBUSY;
 258         } else {
 259                 int error = acpi_scan_try_to_offline(device);
 260                 if (error)
 261                         return error;
 262         }
 263
 264         acpi_handle_debug(handle, "Ejecting\n");
 265
 266         acpi_bus_trim(device);
 267
 268         acpi_evaluate_lck(handle, 0);
 269         /*
 270          * TBD: _EJD support.
 271          */
 272         status = acpi_evaluate_ej0(handle);
 273         if (status == AE_NOT_FOUND)
 274                 return -ENODEV;
 275         else if (ACPI_FAILURE(status))
 276                 return -EIO;
 277
 278         /*
 279          * Verify if eject was indeed successful.  If not, log an error
 280          * message.  No need to call _OST since _EJ0 call was made OK.
 281          */
 282         status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
 283         if (ACPI_FAILURE(status)) {
 284                 acpi_handle_warn(handle,
 285                         "Status check after eject failed (0x%x)\n", status);
 286         } else if (sta & ACPI_STA_DEVICE_ENABLED) {
 287                 acpi_handle_warn(handle,
 288                         "Eject incomplete - status 0x%llx\n", sta);
 289         }
 290
 291         return 0;
 292 }
 293
 294 static int acpi_scan_device_not_present(struct acpi_device *adev)
 295 {
 296         if (!acpi_device_enumerated(adev)) {
 297                 dev_warn(&adev->dev, "Still not present\n");
 298                 return -EALREADY;
 299         }
 300         acpi_bus_trim(adev);
 301         return 0;
 302 }
 303
 304 static int acpi_scan_device_check(struct acpi_device *adev)
 305 {
 306         int error;
 307
 308         acpi_bus_get_status(adev);
 309         if (adev->status.present || adev->status.functional) {
 310                 /*
 311                  * This function is only called for device objects for which
 312                  * matching scan handlers exist.  The only situation in which
 313                  * the scan handler is not attached to this device object yet
 314                  * is when the device has just appeared (either it wasn't
 315                  * present at all before or it was removed and then added
 316                  * again).
 317                  */
 318                 if (adev->handler) {
 319                         dev_warn(&adev->dev, "Already enumerated\n");
 320                         return -EALREADY;
 321                 }
 322                 error = acpi_bus_scan(adev->handle);
 323                 if (error) {
 324                         dev_warn(&adev->dev, "Namespace scan failure\n");
 325                         return error;
 326                 }
 327                 if (!adev->handler) {
 328                         dev_warn(&adev->dev, "Enumeration failure\n");
 329                         error = -ENODEV;
 330                 }
 331         } else {
 332                 error = acpi_scan_device_not_present(adev);
 333         }
 334         return error;
 335 }
 336
 337 static int acpi_scan_bus_check(struct acpi_device *adev)
 338 {
 339         struct acpi_scan_handler *handler = adev->handler;
 340         struct acpi_device *child;
 341         int error;
 342
 343         acpi_bus_get_status(adev);
 344         if (!(adev->status.present || adev->status.functional)) {
 345                 acpi_scan_device_not_present(adev);
 346                 return 0;
 347         }
 348         if (handler && handler->hotplug.scan_dependent)
 349                 return handler->hotplug.scan_dependent(adev);
 350
 351         error = acpi_bus_scan(adev->handle);
 352         if (error) {
 353                 dev_warn(&adev->dev, "Namespace scan failure\n");
 354                 return error;
 355         }
 356         list_for_each_entry(child, &adev->children, node) {
 357                 error = acpi_scan_bus_check(child);
 358                 if (error)
 359                         return error;
 360         }
 361         return 0;
 362 }
 363
 364 static int acpi_generic_hotplug_event(struct acpi_device *adev, u32 type)
 365 {
 366         switch (type) {
 367         case ACPI_NOTIFY_BUS_CHECK:
 368                 return acpi_scan_bus_check(adev);
 369         case ACPI_NOTIFY_DEVICE_CHECK:
 370                 return acpi_scan_device_check(adev);
 371         case ACPI_NOTIFY_EJECT_REQUEST:
 372         case ACPI_OST_EC_OSPM_EJECT:
 373                 if (adev->handler && !adev->handler->hotplug.enabled) {
 374                         dev_info(&adev->dev, "Eject disabled\n");
 375                         return -EPERM;
 376                 }
 377                 acpi_evaluate_ost(adev->handle, ACPI_NOTIFY_EJECT_REQUEST,
 378                                   ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
 379                 return acpi_scan_hot_remove(adev);
 380         }
 381         return -EINVAL;
 382 }
 383
 384 void acpi_device_hotplug(struct acpi_device *adev, u32 src)
 385 {
 386         u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
 387         int error = -ENODEV;
 388
 389         lock_device_hotplug();
 390         mutex_lock(&acpi_scan_lock);
 391
 392         /*
 393          * The device object's ACPI handle cannot become invalid as long as we
 394          * are holding acpi_scan_lock, but it might have become invalid before
 395          * that lock was acquired.
 396          */
 397         if (adev->handle == INVALID_ACPI_HANDLE)
 398                 goto err_out;
 399
 400         if (adev->flags.is_dock_station) {
 401                 error = dock_notify(adev, src);
 402         } else if (adev->flags.hotplug_notify) {
 403                 error = acpi_generic_hotplug_event(adev, src);
 404         } else {
 405                 int (*notify)(struct acpi_device *, u32);
 406
 407                 acpi_lock_hp_context();
 408                 notify = adev->hp ? adev->hp->notify : NULL;
 409                 acpi_unlock_hp_context();
 410                 /*
 411                  * There may be additional notify handlers for device objects
 412                  * without the .event() callback, so ignore them here.
 413                  */
 414                 if (notify)
 415                         error = notify(adev, src);
 416                 else
 417                         goto out;
 418         }
 419         switch (error) {
 420         case 0:
 421                 ost_code = ACPI_OST_SC_SUCCESS;
 422                 break;
 423         case -EPERM:
 424                 ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
 425                 break;
 426         case -EBUSY:
 427                 ost_code = ACPI_OST_SC_DEVICE_BUSY;
 428                 break;
 429         default:
 430                 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
 431                 break;
 432         }
 433
 434  err_out:
 435         acpi_evaluate_ost(adev->handle, src, ost_code, NULL);
 436
 437  out:
 438         acpi_bus_put_acpi_device(adev);
 439         mutex_unlock(&acpi_scan_lock);
 440         unlock_device_hotplug();
 441 }
 442
 443 static void acpi_free_power_resources_lists(struct acpi_device *device)
 444 {
 445         int i;
 446
 447         if (device->wakeup.flags.valid)
 448                 acpi_power_resources_list_free(&device->wakeup.resources);
 449
 450         if (!device->power.flags.power_resources)
 451                 return;
 452
 453         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
 454                 struct acpi_device_power_state *ps = &device->power.states[i];
 455                 acpi_power_resources_list_free(&ps->resources);
 456         }
 457 }
 458
 459 static void acpi_device_release(struct device *dev)
 460 {
 461         struct acpi_device *acpi_dev = to_acpi_device(dev);
 462
 463         acpi_free_properties(acpi_dev);
 464         acpi_free_pnp_ids(&acpi_dev->pnp);
 465         acpi_free_power_resources_lists(acpi_dev);
 466         kfree(acpi_dev);
 467 }
 468
 469 static void acpi_device_del(struct acpi_device *device)
 470 {
 471         struct acpi_device_bus_id *acpi_device_bus_id;
 472
 473         mutex_lock(&acpi_device_lock);
 474         if (device->parent)
 475                 list_del(&device->node);
 476
 477         list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node)
 478                 if (!strcmp(acpi_device_bus_id->bus_id,
 479                             acpi_device_hid(device))) {
 480                         ida_simple_remove(&acpi_device_bus_id->instance_ida, device->pnp.instance_no);
 481                         if (ida_is_empty(&acpi_device_bus_id->instance_ida)) {
 482                                 list_del(&acpi_device_bus_id->node);
 483                                 kfree_const(acpi_device_bus_id->bus_id);
 484                                 kfree(acpi_device_bus_id);
 485                         }
 486                         break;
 487                 }
 488
 489         list_del(&device->wakeup_list);
 490         mutex_unlock(&acpi_device_lock);
 491
 492         acpi_power_add_remove_device(device, false);
 493         acpi_device_remove_files(device);
 494         if (device->remove)
 495                 device->remove(device);
 496
 497         device_del(&device->dev);
 498 }
 499
 500 static BLOCKING_NOTIFIER_HEAD(acpi_reconfig_chain);
 501
 502 static LIST_HEAD(acpi_device_del_list);
 503 static DEFINE_MUTEX(acpi_device_del_lock);
 504
 505 static void acpi_device_del_work_fn(struct work_struct *work_not_used)
 506 {
 507         for (;;) {
 508                 struct acpi_device *adev;
 509
 510                 mutex_lock(&acpi_device_del_lock);
 511
 512                 if (list_empty(&acpi_device_del_list)) {
 513                         mutex_unlock(&acpi_device_del_lock);
 514                         break;
 515                 }
 516                 adev = list_first_entry(&acpi_device_del_list,
 517                                         struct acpi_device, del_list);
 518                 list_del(&adev->del_list);
 519
 520                 mutex_unlock(&acpi_device_del_lock);
 521
 522                 blocking_notifier_call_chain(&acpi_reconfig_chain,
 523                                              ACPI_RECONFIG_DEVICE_REMOVE, adev);
 524
 525                 acpi_device_del(adev);
 526                 /*
 527                  * Drop references to all power resources that might have been
 528                  * used by the device.
 529                  */
 530                 acpi_power_transition(adev, ACPI_STATE_D3_COLD);
 531                 acpi_dev_put(adev);
 532         }
 533 }
 534
 535 /**
 536  * acpi_scan_drop_device - Drop an ACPI device object.
 537  * @handle: Handle of an ACPI namespace node, not used.
 538  * @context: Address of the ACPI device object to drop.
 539  *
 540  * This is invoked by acpi_ns_delete_node() during the removal of the ACPI
 541  * namespace node the device object pointed to by @context is attached to.
 542  *
 543  * The unregistration is carried out asynchronously to avoid running
 544  * acpi_device_del() under the ACPICA's namespace mutex and the list is used to
 545  * ensure the correct ordering (the device objects must be unregistered in the
 546  * same order in which the corresponding namespace nodes are deleted).
 547  */
 548 static void acpi_scan_drop_device(acpi_handle handle, void *context)
 549 {
 550         static DECLARE_WORK(work, acpi_device_del_work_fn);
 551         struct acpi_device *adev = context;
 552
 553         mutex_lock(&acpi_device_del_lock);
 554
 555         /*
 556          * Use the ACPI hotplug workqueue which is ordered, so this work item
 557          * won't run after any hotplug work items submitted subsequently.  That
 558          * prevents attempts to register device objects identical to those being
 559          * deleted from happening concurrently (such attempts result from
 560          * hotplug events handled via the ACPI hotplug workqueue).  It also will
 561          * run after all of the work items submitted previously, which helps
 562          * those work items to ensure that they are not accessing stale device
 563          * objects.
 564          */
 565         if (list_empty(&acpi_device_del_list))
 566                 acpi_queue_hotplug_work(&work);
 567
 568         list_add_tail(&adev->del_list, &acpi_device_del_list);
 569         /* Make acpi_ns_validate_handle() return NULL for this handle. */
 570         adev->handle = INVALID_ACPI_HANDLE;
 571
 572         mutex_unlock(&acpi_device_del_lock);
 573 }
 574
 575 static struct acpi_device *handle_to_device(acpi_handle handle,
 576                                             void (*callback)(void *))
 577 {
 578         struct acpi_device *adev = NULL;
 579         acpi_status status;
 580
 581         status = acpi_get_data_full(handle, acpi_scan_drop_device,
 582                                     (void **)&adev, callback);
 583         if (ACPI_FAILURE(status) || !adev) {
 584                 acpi_handle_debug(handle, "No context!\n");
 585                 return NULL;
 586         }
 587         return adev;
 588 }
 589
 590 int acpi_bus_get_device(acpi_handle handle, struct acpi_device **device)
 591 {
 592         if (!device)
 593                 return -EINVAL;
 594
 595         *device = handle_to_device(handle, NULL);
 596         if (!*device)
 597                 return -ENODEV;
 598
 599         return 0;
 600 }
 601 EXPORT_SYMBOL(acpi_bus_get_device);
 602
 603 /**
 604  * acpi_fetch_acpi_dev - Retrieve ACPI device object.
 605  * @handle: ACPI handle associated with the requested ACPI device object.
 606  *
 607  * Return a pointer to the ACPI device object associated with @handle, if
 608  * present, or NULL otherwise.
 609  */
 610 struct acpi_device *acpi_fetch_acpi_dev(acpi_handle handle)
 611 {
 612         return handle_to_device(handle, NULL);
 613 }
 614 EXPORT_SYMBOL_GPL(acpi_fetch_acpi_dev);
 615
 616 static void get_acpi_device(void *dev)
 617 {
 618         acpi_dev_get(dev);
 619 }
 620
 621 struct acpi_device *acpi_bus_get_acpi_device(acpi_handle handle)
 622 {
 623         return handle_to_device(handle, get_acpi_device);
 624 }
 625 EXPORT_SYMBOL_GPL(acpi_bus_get_acpi_device);
 626
 627 static struct acpi_device_bus_id *acpi_device_bus_id_match(const char *dev_id)
 628 {
 629         struct acpi_device_bus_id *acpi_device_bus_id;
 630
 631         /* Find suitable bus_id and instance number in acpi_bus_id_list. */
 632         list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
 633                 if (!strcmp(acpi_device_bus_id->bus_id, dev_id))
 634                         return acpi_device_bus_id;
 635         }
 636         return NULL;
 637 }
 638
 639 static int acpi_device_set_name(struct acpi_device *device,
 640                                 struct acpi_device_bus_id *acpi_device_bus_id)
 641 {
 642         struct ida *instance_ida = &acpi_device_bus_id->instance_ida;
 643         int result;
 644
 645         result = ida_simple_get(instance_ida, 0, ACPI_MAX_DEVICE_INSTANCES, GFP_KERNEL);
 646         if (result < 0)
 647                 return result;
 648
 649         device->pnp.instance_no = result;
 650         dev_set_name(&device->dev, "%s:%02x", acpi_device_bus_id->bus_id, result);
 651         return 0;
 652 }
 653
 654 static int acpi_tie_acpi_dev(struct acpi_device *adev)
 655 {
 656         acpi_handle handle = adev->handle;
 657         acpi_status status;
 658
 659         if (!handle)
 660                 return 0;
 661
 662         status = acpi_attach_data(handle, acpi_scan_drop_device, adev);
 663         if (ACPI_FAILURE(status)) {
 664                 acpi_handle_err(handle, "Unable to attach device data\n");
 665                 return -ENODEV;
 666         }
 667
 668         return 0;
 669 }
 670
 671 static void acpi_store_pld_crc(struct acpi_device *adev)
 672 {
 673         struct acpi_pld_info *pld;
 674         acpi_status status;
 675
 676         status = acpi_get_physical_device_location(adev->handle, &pld);
 677         if (ACPI_FAILURE(status))
 678                 return;
 679
 680         adev->pld_crc = crc32(~0, pld, sizeof(*pld));
 681         ACPI_FREE(pld);
 682 }
 683
 684 static int __acpi_device_add(struct acpi_device *device,
 685                              void (*release)(struct device *))
 686 {
 687         struct acpi_device_bus_id *acpi_device_bus_id;
 688         int result;
 689
 690         /*
 691          * Linkage
 692          * -------
 693          * Link this device to its parent and siblings.
 694          */
 695         INIT_LIST_HEAD(&device->children);
 696         INIT_LIST_HEAD(&device->node);
 697         INIT_LIST_HEAD(&device->wakeup_list);
 698         INIT_LIST_HEAD(&device->physical_node_list);
 699         INIT_LIST_HEAD(&device->del_list);
 700         mutex_init(&device->physical_node_lock);
 701
 702         mutex_lock(&acpi_device_lock);
 703
 704         acpi_device_bus_id = acpi_device_bus_id_match(acpi_device_hid(device));
 705         if (acpi_device_bus_id) {
 706                 result = acpi_device_set_name(device, acpi_device_bus_id);
 707                 if (result)
 708                         goto err_unlock;
 709         } else {
 710                 acpi_device_bus_id = kzalloc(sizeof(*acpi_device_bus_id),
 711                                              GFP_KERNEL);
 712                 if (!acpi_device_bus_id) {
 713                         result = -ENOMEM;
 714                         goto err_unlock;
 715                 }
 716                 acpi_device_bus_id->bus_id =
 717                         kstrdup_const(acpi_device_hid(device), GFP_KERNEL);
 718                 if (!acpi_device_bus_id->bus_id) {
 719                         kfree(acpi_device_bus_id);
 720                         result = -ENOMEM;
 721                         goto err_unlock;
 722                 }
 723
 724                 ida_init(&acpi_device_bus_id->instance_ida);
 725
 726                 result = acpi_device_set_name(device, acpi_device_bus_id);
 727                 if (result) {
 728                         kfree_const(acpi_device_bus_id->bus_id);
 729                         kfree(acpi_device_bus_id);
 730                         goto err_unlock;
 731                 }
 732
 733                 list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
 734         }
 735
 736         if (device->parent)
 737                 list_add_tail(&device->node, &device->parent->children);
 738
 739         if (device->wakeup.flags.valid)
 740                 list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);
 741
 742         acpi_store_pld_crc(device);
 743
 744         mutex_unlock(&acpi_device_lock);
 745
 746         if (device->parent)
 747                 device->dev.parent = &device->parent->dev;
 748
 749         device->dev.bus = &acpi_bus_type;
 750         device->dev.release = release;
 751         result = device_add(&device->dev);
 752         if (result) {
 753                 dev_err(&device->dev, "Error registering device\n");
 754                 goto err;
 755         }
 756
 757         result = acpi_device_setup_files(device);
 758         if (result)
 759                 pr_err("Error creating sysfs interface for device %s\n",
 760                        dev_name(&device->dev));
 761
 762         return 0;
 763
 764 err:
 765         mutex_lock(&acpi_device_lock);
 766
 767         if (device->parent)
 768                 list_del(&device->node);
 769
 770         list_del(&device->wakeup_list);
 771
 772 err_unlock:
 773         mutex_unlock(&acpi_device_lock);
 774
 775         acpi_detach_data(device->handle, acpi_scan_drop_device);
 776
 777         return result;
 778 }
 779
 780 int acpi_device_add(struct acpi_device *adev, void (*release)(struct device *))
 781 {
 782         int ret;
 783
 784         ret = acpi_tie_acpi_dev(adev);
 785         if (ret)
 786                 return ret;
 787
 788         return __acpi_device_add(adev, release);
 789 }
 790
 791 /* --------------------------------------------------------------------------
 792                                  Device Enumeration
 793    -------------------------------------------------------------------------- */
 794 static bool acpi_info_matches_ids(struct acpi_device_info *info,
 795                                   const char * const ids[])
 796 {
 797         struct acpi_pnp_device_id_list *cid_list = NULL;
 798         int i, index;
 799
 800         if (!(info->valid & ACPI_VALID_HID))
 801                 return false;
 802
 803         index = match_string(ids, -1, info->hardware_id.string);
 804         if (index >= 0)
 805                 return true;
 806
 807         if (info->valid & ACPI_VALID_CID)
 808                 cid_list = &info->compatible_id_list;
 809
 810         if (!cid_list)
 811                 return false;
 812
 813         for (i = 0; i < cid_list->count; i++) {
 814                 index = match_string(ids, -1, cid_list->ids[i].string);
 815                 if (index >= 0)
 816                         return true;
 817         }
 818
 819         return false;
 820 }
 821
 822 /* List of HIDs for which we ignore matching ACPI devices, when checking _DEP lists. */
 823 static const char * const acpi_ignore_dep_ids[] = {
 824         "PNP0D80", /* Windows-compatible System Power Management Controller */
 825         "INT33BD", /* Intel Baytrail Mailbox Device */
 826         NULL
 827 };
 828
 829 /* List of HIDs for which we honor deps of matching ACPI devs, when checking _DEP lists. */
 830 static const char * const acpi_honor_dep_ids[] = {
 831         "INT3472", /* Camera sensor PMIC / clk and regulator info */
 832         NULL
 833 };
 834
 835 static struct acpi_device *acpi_bus_get_parent(acpi_handle handle)
 836 {
 837         struct acpi_device *device;
 838         acpi_status status;
 839
 840         /*
 841          * Fixed hardware devices do not appear in the namespace and do not
 842          * have handles, but we fabricate acpi_devices for them, so we have
 843          * to deal with them specially.
 844          */
 845         if (!handle)
 846                 return acpi_root;
 847
 848         do {
 849                 status = acpi_get_parent(handle, &handle);
 850                 if (ACPI_FAILURE(status))
 851                         return status == AE_NULL_ENTRY ? NULL : acpi_root;
 852
 853                 device = acpi_fetch_acpi_dev(handle);
 854         } while (!device);
 855         return device;
 856 }
 857
 858 acpi_status
 859 acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
 860 {
 861         acpi_status status;
 862         acpi_handle tmp;
 863         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
 864         union acpi_object *obj;
 865
 866         status = acpi_get_handle(handle, "_EJD", &tmp);
 867         if (ACPI_FAILURE(status))
 868                 return status;
 869
 870         status = acpi_evaluate_object(handle, "_EJD", NULL, &buffer);
 871         if (ACPI_SUCCESS(status)) {
 872                 obj = buffer.pointer;
 873                 status = acpi_get_handle(ACPI_ROOT_OBJECT, obj->string.pointer,
 874                                          ejd);
 875                 kfree(buffer.pointer);
 876         }
 877         return status;
 878 }
 879 EXPORT_SYMBOL_GPL(acpi_bus_get_ejd);
 880
 881 static int acpi_bus_extract_wakeup_device_power_package(struct acpi_device *dev)
 882 {
 883         acpi_handle handle = dev->handle;
 884         struct acpi_device_wakeup *wakeup = &dev->wakeup;
 885         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 886         union acpi_object *package = NULL;
 887         union acpi_object *element = NULL;
 888         acpi_status status;
 889         int err = -ENODATA;
 890
 891         INIT_LIST_HEAD(&wakeup->resources);
 892
 893         /* _PRW */
 894         status = acpi_evaluate_object(handle, "_PRW", NULL, &buffer);
 895         if (ACPI_FAILURE(status)) {
 896                 acpi_handle_info(handle, "_PRW evaluation failed: %s\n",
 897                                  acpi_format_exception(status));
 898                 return err;
 899         }
 900
 901         package = (union acpi_object *)buffer.pointer;
 902
 903         if (!package || package->package.count < 2)
 904                 goto out;
 905
 906         element = &(package->package.elements[0]);
 907         if (!element)
 908                 goto out;
 909
 910         if (element->type == ACPI_TYPE_PACKAGE) {
 911                 if ((element->package.count < 2) ||
 912                     (element->package.elements[0].type !=
 913                      ACPI_TYPE_LOCAL_REFERENCE)
 914                     || (element->package.elements[1].type != ACPI_TYPE_INTEGER))
 915                         goto out;
 916
 917                 wakeup->gpe_device =
 918                     element->package.elements[0].reference.handle;
 919                 wakeup->gpe_number =
 920                     (u32) element->package.elements[1].integer.value;
 921         } else if (element->type == ACPI_TYPE_INTEGER) {
 922                 wakeup->gpe_device = NULL;
 923                 wakeup->gpe_number = element->integer.value;
 924         } else {
 925                 goto out;
 926         }
 927
 928         element = &(package->package.elements[1]);
 929         if (element->type != ACPI_TYPE_INTEGER)
 930                 goto out;
 931
 932         wakeup->sleep_state = element->integer.value;
 933
 934         err = acpi_extract_power_resources(package, 2, &wakeup->resources);
 935         if (err)
 936                 goto out;
 937
 938         if (!list_empty(&wakeup->resources)) {
 939                 int sleep_state;
 940
 941                 err = acpi_power_wakeup_list_init(&wakeup->resources,
 942                                                   &sleep_state);
 943                 if (err) {
 944                         acpi_handle_warn(handle, "Retrieving current states "
 945                                          "of wakeup power resources failed\n");
 946                         acpi_power_resources_list_free(&wakeup->resources);
 947                         goto out;
 948                 }
 949                 if (sleep_state < wakeup->sleep_state) {
 950                         acpi_handle_warn(handle, "Overriding _PRW sleep state "
 951                                          "(S%d) by S%d from power resources\n",
 952                                          (int)wakeup->sleep_state, sleep_state);
 953                         wakeup->sleep_state = sleep_state;
 954                 }
 955         }
 956
 957  out:
 958         kfree(buffer.pointer);
 959         return err;
 960 }
 961
 962 static bool acpi_wakeup_gpe_init(struct acpi_device *device)
 963 {
 964         static const struct acpi_device_id button_device_ids[] = {
 965                 {"PNP0C0C", 0},         /* Power button */
 966                 {"PNP0C0D", 0},         /* Lid */
 967                 {"PNP0C0E", 0},         /* Sleep button */
 968                 {"", 0},
 969         };
 970         struct acpi_device_wakeup *wakeup = &device->wakeup;
 971         acpi_status status;
 972
 973         wakeup->flags.notifier_present = 0;
 974
 975         /* Power button, Lid switch always enable wakeup */
 976         if (!acpi_match_device_ids(device, button_device_ids)) {
 977                 if (!acpi_match_device_ids(device, &button_device_ids[1])) {
 978                         /* Do not use Lid/sleep button for S5 wakeup */
 979                         if (wakeup->sleep_state == ACPI_STATE_S5)
 980                                 wakeup->sleep_state = ACPI_STATE_S4;
 981                 }
 982                 acpi_mark_gpe_for_wake(wakeup->gpe_device, wakeup->gpe_number);
 983                 device_set_wakeup_capable(&device->dev, true);
 984                 return true;
 985         }
 986
 987         status = acpi_setup_gpe_for_wake(device->handle, wakeup->gpe_device,
 988                                          wakeup->gpe_number);
 989         return ACPI_SUCCESS(status);
 990 }
 991
 992 static void acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
 993 {
 994         int err;
 995
 996         /* Presence of _PRW indicates wake capable */
 997         if (!acpi_has_method(device->handle, "_PRW"))
 998                 return;
 999
1000         err = acpi_bus_extract_wakeup_device_power_package(device);
1001         if (err) {
1002                 dev_err(&device->dev, "Unable to extract wakeup power resources");
1003                 return;
1004         }
1005
1006         device->wakeup.flags.valid = acpi_wakeup_gpe_init(device);
1007         device->wakeup.prepare_count = 0;
1008         /*
1009          * Call _PSW/_DSW object to disable its ability to wake the sleeping
1010          * system for the ACPI device with the _PRW object.
1011          * The _PSW object is deprecated in ACPI 3.0 and is replaced by _DSW.
1012          * So it is necessary to call _DSW object first. Only when it is not
1013          * present will the _PSW object used.
1014          */
1015         err = acpi_device_sleep_wake(device, 0, 0, 0);
1016         if (err)
1017                 pr_debug("error in _DSW or _PSW evaluation\n");
1018 }
1019
1020 static void acpi_bus_init_power_state(struct acpi_device *device, int state)
1021 {
1022         struct acpi_device_power_state *ps = &device->power.states[state];
1023         char pathname[5] = { '_', 'P', 'R', '0' + state, '\0' };
1024         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1025         acpi_status status;
1026
1027         INIT_LIST_HEAD(&ps->resources);
1028
1029         /* Evaluate "_PRx" to get referenced power resources */
1030         status = acpi_evaluate_object(device->handle, pathname, NULL, &buffer);
1031         if (ACPI_SUCCESS(status)) {
1032                 union acpi_object *package = buffer.pointer;
1033
1034                 if (buffer.length && package
1035                     && package->type == ACPI_TYPE_PACKAGE
1036                     && package->package.count)
1037                         acpi_extract_power_resources(package, 0, &ps->resources);
1038
1039                 ACPI_FREE(buffer.pointer);
1040         }
1041
1042         /* Evaluate "_PSx" to see if we can do explicit sets */
1043         pathname[2] = 'S';
1044         if (acpi_has_method(device->handle, pathname))
1045                 ps->flags.explicit_set = 1;
1046
1047         /* State is valid if there are means to put the device into it. */
1048         if (!list_empty(&ps->resources) || ps->flags.explicit_set)
1049                 ps->flags.valid = 1;
1050
1051         ps->power = -1;         /* Unknown - driver assigned */
1052         ps->latency = -1;       /* Unknown - driver assigned */
1053 }
1054
1055 static void acpi_bus_get_power_flags(struct acpi_device *device)
1056 {
1057         unsigned long long dsc = ACPI_STATE_D0;
1058         u32 i;
1059
1060         /* Presence of _PS0|_PR0 indicates 'power manageable' */
1061         if (!acpi_has_method(device->handle, "_PS0") &&
1062             !acpi_has_method(device->handle, "_PR0"))
1063                 return;
1064
1065         device->flags.power_manageable = 1;
1066
1067         /*
1068          * Power Management Flags
1069          */
1070         if (acpi_has_method(device->handle, "_PSC"))
1071                 device->power.flags.explicit_get = 1;
1072
1073         if (acpi_has_method(device->handle, "_IRC"))
1074                 device->power.flags.inrush_current = 1;
1075
1076         if (acpi_has_method(device->handle, "_DSW"))
1077                 device->power.flags.dsw_present = 1;
1078
1079         acpi_evaluate_integer(device->handle, "_DSC", NULL, &dsc);
1080         device->power.state_for_enumeration = dsc;
1081
1082         /*
1083          * Enumerate supported power management states
1084          */
1085         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++)
1086                 acpi_bus_init_power_state(device, i);
1087
1088         INIT_LIST_HEAD(&device->power.states[ACPI_STATE_D3_COLD].resources);
1089
1090         /* Set the defaults for D0 and D3hot (always supported). */
1091         device->power.states[ACPI_STATE_D0].flags.valid = 1;
1092         device->power.states[ACPI_STATE_D0].power = 100;
1093         device->power.states[ACPI_STATE_D3_HOT].flags.valid = 1;
1094
1095         /*
1096          * Use power resources only if the D0 list of them is populated, because
1097          * some platforms may provide _PR3 only to indicate D3cold support and
1098          * in those cases the power resources list returned by it may be bogus.
1099          */
1100         if (!list_empty(&device->power.states[ACPI_STATE_D0].resources)) {
1101                 device->power.flags.power_resources = 1;
1102                 /*
1103                  * D3cold is supported if the D3hot list of power resources is
1104                  * not empty.
1105                  */
1106                 if (!list_empty(&device->power.states[ACPI_STATE_D3_HOT].resources))
1107                         device->power.states[ACPI_STATE_D3_COLD].flags.valid = 1;
1108         }
1109
1110         if (acpi_bus_init_power(device))
1111                 device->flags.power_manageable = 0;
1112 }
1113
1114 static void acpi_bus_get_flags(struct acpi_device *device)
1115 {
1116         /* Presence of _STA indicates 'dynamic_status' */
1117         if (acpi_has_method(device->handle, "_STA"))
1118                 device->flags.dynamic_status = 1;
1119
1120         /* Presence of _RMV indicates 'removable' */
1121         if (acpi_has_method(device->handle, "_RMV"))
1122                 device->flags.removable = 1;
1123
1124         /* Presence of _EJD|_EJ0 indicates 'ejectable' */
1125         if (acpi_has_method(device->handle, "_EJD") ||
1126             acpi_has_method(device->handle, "_EJ0"))
1127                 device->flags.ejectable = 1;
1128 }
1129
1130 static void acpi_device_get_busid(struct acpi_device *device)
1131 {
1132         char bus_id[5] = { '?', 0 };
1133         struct acpi_buffer buffer = { sizeof(bus_id), bus_id };
1134         int i = 0;
1135
1136         /*
1137          * Bus ID
1138          * ------
1139          * The device's Bus ID is simply the object name.
1140          * TBD: Shouldn't this value be unique (within the ACPI namespace)?
1141          */
1142         if (ACPI_IS_ROOT_DEVICE(device)) {
1143                 strcpy(device->pnp.bus_id, "ACPI");
1144                 return;
1145         }
1146
1147         switch (device->device_type) {
1148         case ACPI_BUS_TYPE_POWER_BUTTON:
1149                 strcpy(device->pnp.bus_id, "PWRF");
1150                 break;
1151         case ACPI_BUS_TYPE_SLEEP_BUTTON:
1152                 strcpy(device->pnp.bus_id, "SLPF");
1153                 break;
1154         case ACPI_BUS_TYPE_ECDT_EC:
1155                 strcpy(device->pnp.bus_id, "ECDT");
1156                 break;
1157         default:
1158                 acpi_get_name(device->handle, ACPI_SINGLE_NAME, &buffer);
1159                 /* Clean up trailing underscores (if any) */
1160                 for (i = 3; i > 1; i--) {
1161                         if (bus_id[i] == '_')
1162                                 bus_id[i] = '\0';
1163                         else
1164                                 break;
1165                 }
1166                 strcpy(device->pnp.bus_id, bus_id);
1167                 break;
1168         }
1169 }
1170
1171 /*
1172  * acpi_ata_match - see if an acpi object is an ATA device
1173  *
1174  * If an acpi object has one of the ACPI ATA methods defined,
1175  * then we can safely call it an ATA device.
1176  */
1177 bool acpi_ata_match(acpi_handle handle)
1178 {
1179         return acpi_has_method(handle, "_GTF") ||
1180                acpi_has_method(handle, "_GTM") ||
1181                acpi_has_method(handle, "_STM") ||
1182                acpi_has_method(handle, "_SDD");
1183 }
1184
1185 /*
1186  * acpi_bay_match - see if an acpi object is an ejectable driver bay
1187  *
1188  * If an acpi object is ejectable and has one of the ACPI ATA methods defined,
1189  * then we can safely call it an ejectable drive bay
1190  */
1191 bool acpi_bay_match(acpi_handle handle)
1192 {
1193         acpi_handle phandle;
1194
1195         if (!acpi_has_method(handle, "_EJ0"))
1196                 return false;
1197         if (acpi_ata_match(handle))
1198                 return true;
1199         if (ACPI_FAILURE(acpi_get_parent(handle, &phandle)))
1200                 return false;
1201
1202         return acpi_ata_match(phandle);
1203 }
1204
1205 bool acpi_device_is_battery(struct acpi_device *adev)
1206 {
1207         struct acpi_hardware_id *hwid;
1208
1209         list_for_each_entry(hwid, &adev->pnp.ids, list)
1210                 if (!strcmp("PNP0C0A", hwid->id))
1211                         return true;
1212
1213         return false;
1214 }
1215
1216 static bool is_ejectable_bay(struct acpi_device *adev)
1217 {
1218         acpi_handle handle = adev->handle;
1219
1220         if (acpi_has_method(handle, "_EJ0") && acpi_device_is_battery(adev))
1221                 return true;
1222
1223         return acpi_bay_match(handle);
1224 }
1225
1226 /*
1227  * acpi_dock_match - see if an acpi object has a _DCK method
1228  */
1229 bool acpi_dock_match(acpi_handle handle)
1230 {
1231         return acpi_has_method(handle, "_DCK");
1232 }
1233
1234 static acpi_status
1235 acpi_backlight_cap_match(acpi_handle handle, u32 level, void *context,
1236                           void **return_value)
1237 {
1238         long *cap = context;
1239
1240         if (acpi_has_method(handle, "_BCM") &&
1241             acpi_has_method(handle, "_BCL")) {
1242                 acpi_handle_debug(handle, "Found generic backlight support\n");
1243                 *cap |= ACPI_VIDEO_BACKLIGHT;
1244                 /* We have backlight support, no need to scan further */
1245                 return AE_CTRL_TERMINATE;
1246         }
1247         return 0;
1248 }
1249
1250 /* Returns true if the ACPI object is a video device which can be
1251  * handled by video.ko.
1252  * The device will get a Linux specific CID added in scan.c to
1253  * identify the device as an ACPI graphics device
1254  * Be aware that the graphics device may not be physically present
1255  * Use acpi_video_get_capabilities() to detect general ACPI video
1256  * capabilities of present cards
1257  */
1258 long acpi_is_video_device(acpi_handle handle)
1259 {
1260         long video_caps = 0;
1261
1262         /* Is this device able to support video switching ? */
1263         if (acpi_has_method(handle, "_DOD") || acpi_has_method(handle, "_DOS"))
1264                 video_caps |= ACPI_VIDEO_OUTPUT_SWITCHING;
1265
1266         /* Is this device able to retrieve a video ROM ? */
1267         if (acpi_has_method(handle, "_ROM"))
1268                 video_caps |= ACPI_VIDEO_ROM_AVAILABLE;
1269
1270         /* Is this device able to configure which video head to be POSTed ? */
1271         if (acpi_has_method(handle, "_VPO") &&
1272             acpi_has_method(handle, "_GPD") &&
1273             acpi_has_method(handle, "_SPD"))
1274                 video_caps |= ACPI_VIDEO_DEVICE_POSTING;
1275
1276         /* Only check for backlight functionality if one of the above hit. */
1277         if (video_caps)
1278                 acpi_walk_namespace(ACPI_TYPE_DEVICE, handle,
1279                                     ACPI_UINT32_MAX, acpi_backlight_cap_match, NULL,
1280                                     &video_caps, NULL);
1281
1282         return video_caps;
1283 }
1284 EXPORT_SYMBOL(acpi_is_video_device);
1285
1286 const char *acpi_device_hid(struct acpi_device *device)
1287 {
1288         struct acpi_hardware_id *hid;
1289
1290         if (list_empty(&device->pnp.ids))
1291                 return dummy_hid;
1292
1293         hid = list_first_entry(&device->pnp.ids, struct acpi_hardware_id, list);
1294         return hid->id;
1295 }
1296 EXPORT_SYMBOL(acpi_device_hid);
1297
1298 static void acpi_add_id(struct acpi_device_pnp *pnp, const char *dev_id)
1299 {
1300         struct acpi_hardware_id *id;
1301
1302         id = kmalloc(sizeof(*id), GFP_KERNEL);
1303         if (!id)
1304                 return;
1305
1306         id->id = kstrdup_const(dev_id, GFP_KERNEL);
1307         if (!id->id) {
1308                 kfree(id);
1309                 return;
1310         }
1311
1312         list_add_tail(&id->list, &pnp->ids);
1313         pnp->type.hardware_id = 1;
1314 }
1315
1316 /*
1317  * Old IBM workstations have a DSDT bug wherein the SMBus object
1318  * lacks the SMBUS01 HID and the methods do not have the necessary "_"
1319  * prefix.  Work around this.
1320  */
1321 static bool acpi_ibm_smbus_match(acpi_handle handle)
1322 {
1323         char node_name[ACPI_PATH_SEGMENT_LENGTH];
1324         struct acpi_buffer path = { sizeof(node_name), node_name };
1325
1326         if (!dmi_name_in_vendors("IBM"))
1327                 return false;
1328
1329         /* Look for SMBS object */
1330         if (ACPI_FAILURE(acpi_get_name(handle, ACPI_SINGLE_NAME, &path)) ||
1331             strcmp("SMBS", path.pointer))
1332                 return false;
1333
1334         /* Does it have the necessary (but misnamed) methods? */
1335         if (acpi_has_method(handle, "SBI") &&
1336             acpi_has_method(handle, "SBR") &&
1337             acpi_has_method(handle, "SBW"))
1338                 return true;
1339
1340         return false;
1341 }
1342
1343 static bool acpi_object_is_system_bus(acpi_handle handle)
1344 {
1345         acpi_handle tmp;
1346
1347         if (ACPI_SUCCESS(acpi_get_handle(NULL, "\\_SB", &tmp)) &&
1348             tmp == handle)
1349                 return true;
1350         if (ACPI_SUCCESS(acpi_get_handle(NULL, "\\_TZ", &tmp)) &&
1351             tmp == handle)
1352                 return true;
1353
1354         return false;
1355 }
1356
1357 static void acpi_set_pnp_ids(acpi_handle handle, struct acpi_device_pnp *pnp,
1358                              int device_type)
1359 {
1360         struct acpi_device_info *info = NULL;
1361         struct acpi_pnp_device_id_list *cid_list;
1362         int i;
1363
1364         switch (device_type) {
1365         case ACPI_BUS_TYPE_DEVICE:
1366                 if (handle == ACPI_ROOT_OBJECT) {
1367                         acpi_add_id(pnp, ACPI_SYSTEM_HID);
1368                         break;
1369                 }
1370
1371                 acpi_get_object_info(handle, &info);
1372                 if (!info) {
1373                         pr_err("%s: Error reading device info\n", __func__);
1374                         return;
1375                 }
1376
1377                 if (info->valid & ACPI_VALID_HID) {
1378                         acpi_add_id(pnp, info->hardware_id.string);
1379                         pnp->type.platform_id = 1;
1380                 }
1381                 if (info->valid & ACPI_VALID_CID) {
1382                         cid_list = &info->compatible_id_list;
1383                         for (i = 0; i < cid_list->count; i++)
1384                                 acpi_add_id(pnp, cid_list->ids[i].string);
1385                 }
1386                 if (info->valid & ACPI_VALID_ADR) {
1387                         pnp->bus_address = info->address;
1388                         pnp->type.bus_address = 1;
1389                 }
1390                 if (info->valid & ACPI_VALID_UID)
1391                         pnp->unique_id = kstrdup(info->unique_id.string,
1392                                                         GFP_KERNEL);
1393                 if (info->valid & ACPI_VALID_CLS)
1394                         acpi_add_id(pnp, info->class_code.string);
1395
1396                 kfree(info);
1397
1398                 /*
1399                  * Some devices don't reliably have _HIDs & _CIDs, so add
1400                  * synthetic HIDs to make sure drivers can find them.
1401                  */
1402                 if (acpi_is_video_device(handle))
1403                         acpi_add_id(pnp, ACPI_VIDEO_HID);
1404                 else if (acpi_bay_match(handle))
1405                         acpi_add_id(pnp, ACPI_BAY_HID);
1406                 else if (acpi_dock_match(handle))
1407                         acpi_add_id(pnp, ACPI_DOCK_HID);
1408                 else if (acpi_ibm_smbus_match(handle))
1409                         acpi_add_id(pnp, ACPI_SMBUS_IBM_HID);
1410                 else if (list_empty(&pnp->ids) &&
1411                          acpi_object_is_system_bus(handle)) {
1412                         /* \_SB, \_TZ, LNXSYBUS */
1413                         acpi_add_id(pnp, ACPI_BUS_HID);
1414                         strcpy(pnp->device_name, ACPI_BUS_DEVICE_NAME);
1415                         strcpy(pnp->device_class, ACPI_BUS_CLASS);
1416                 }
1417
1418                 break;
1419         case ACPI_BUS_TYPE_POWER:
1420                 acpi_add_id(pnp, ACPI_POWER_HID);
1421                 break;
1422         case ACPI_BUS_TYPE_PROCESSOR:
1423                 acpi_add_id(pnp, ACPI_PROCESSOR_OBJECT_HID);
1424                 break;
1425         case ACPI_BUS_TYPE_THERMAL:
1426                 acpi_add_id(pnp, ACPI_THERMAL_HID);
1427                 break;
1428         case ACPI_BUS_TYPE_POWER_BUTTON:
1429                 acpi_add_id(pnp, ACPI_BUTTON_HID_POWERF);
1430                 break;
1431         case ACPI_BUS_TYPE_SLEEP_BUTTON:
1432                 acpi_add_id(pnp, ACPI_BUTTON_HID_SLEEPF);
1433                 break;
1434         case ACPI_BUS_TYPE_ECDT_EC:
1435                 acpi_add_id(pnp, ACPI_ECDT_HID);
1436                 break;
1437         }
1438 }
1439
1440 void acpi_free_pnp_ids(struct acpi_device_pnp *pnp)
1441 {
1442         struct acpi_hardware_id *id, *tmp;
1443
1444         list_for_each_entry_safe(id, tmp, &pnp->ids, list) {
1445                 kfree_const(id->id);
1446                 kfree(id);
1447         }
1448         kfree(pnp->unique_id);
1449 }
1450
1451 /**
1452  * acpi_dma_supported - Check DMA support for the specified device.
1453  * @adev: The pointer to acpi device
1454  *
1455  * Return false if DMA is not supported. Otherwise, return true
1456  */
1457 bool acpi_dma_supported(const struct acpi_device *adev)
1458 {
1459         if (!adev)
1460                 return false;
1461
1462         if (adev->flags.cca_seen)
1463                 return true;
1464
1465         /*
1466         * Per ACPI 6.0 sec 6.2.17, assume devices can do cache-coherent
1467         * DMA on "Intel platforms".  Presumably that includes all x86 and
1468         * ia64, and other arches will set CONFIG_ACPI_CCA_REQUIRED=y.
1469         */
1470         if (!IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED))
1471                 return true;
1472
1473         return false;
1474 }
1475
1476 /**
1477  * acpi_get_dma_attr - Check the supported DMA attr for the specified device.
1478  * @adev: The pointer to acpi device
1479  *
1480  * Return enum dev_dma_attr.
1481  */
1482 enum dev_dma_attr acpi_get_dma_attr(struct acpi_device *adev)
1483 {
1484         if (!acpi_dma_supported(adev))
1485                 return DEV_DMA_NOT_SUPPORTED;
1486
1487         if (adev->flags.coherent_dma)
1488                 return DEV_DMA_COHERENT;
1489         else
1490                 return DEV_DMA_NON_COHERENT;
1491 }
1492
1493 /**
1494  * acpi_dma_get_range() - Get device DMA parameters.
1495  *
1496  * @dev: device to configure
1497  * @dma_addr: pointer device DMA address result
1498  * @offset: pointer to the DMA offset result
1499  * @size: pointer to DMA range size result
1500  *
1501  * Evaluate DMA regions and return respectively DMA region start, offset
1502  * and size in dma_addr, offset and size on parsing success; it does not
1503  * update the passed in values on failure.
1504  *
1505  * Return 0 on success, < 0 on failure.
1506  */
1507 int acpi_dma_get_range(struct device *dev, u64 *dma_addr, u64 *offset,
1508                        u64 *size)
1509 {
1510         struct acpi_device *adev;
1511         LIST_HEAD(list);
1512         struct resource_entry *rentry;
1513         int ret;
1514         struct device *dma_dev = dev;
1515         u64 len, dma_start = U64_MAX, dma_end = 0, dma_offset = 0;
1516
1517         /*
1518          * Walk the device tree chasing an ACPI companion with a _DMA
1519          * object while we go. Stop if we find a device with an ACPI
1520          * companion containing a _DMA method.
1521          */
1522         do {
1523                 adev = ACPI_COMPANION(dma_dev);
1524                 if (adev && acpi_has_method(adev->handle, METHOD_NAME__DMA))
1525                         break;
1526
1527                 dma_dev = dma_dev->parent;
1528         } while (dma_dev);
1529
1530         if (!dma_dev)
1531                 return -ENODEV;
1532
1533         if (!acpi_has_method(adev->handle, METHOD_NAME__CRS)) {
1534                 acpi_handle_warn(adev->handle, "_DMA is valid only if _CRS is present\n");
1535                 return -EINVAL;
1536         }
1537
1538         ret = acpi_dev_get_dma_resources(adev, &list);
1539         if (ret > 0) {
1540                 list_for_each_entry(rentry, &list, node) {
1541                         if (dma_offset && rentry->offset != dma_offset) {
1542                                 ret = -EINVAL;
1543                                 dev_warn(dma_dev, "Can't handle multiple windows with different offsets\n");
1544                                 goto out;
1545                         }
1546                         dma_offset = rentry->offset;
1547
1548                         /* Take lower and upper limits */
1549                         if (rentry->res->start < dma_start)
1550                                 dma_start = rentry->res->start;
1551                         if (rentry->res->end > dma_end)
1552                                 dma_end = rentry->res->end;
1553                 }
1554
1555                 if (dma_start >= dma_end) {
1556                         ret = -EINVAL;
1557                         dev_dbg(dma_dev, "Invalid DMA regions configuration\n");
1558                         goto out;
1559                 }
1560
1561                 *dma_addr = dma_start - dma_offset;
1562                 len = dma_end - dma_start;
1563                 *size = max(len, len + 1);
1564                 *offset = dma_offset;
1565         }
1566  out:
1567         acpi_dev_free_resource_list(&list);
1568
1569         return ret >= 0 ? 0 : ret;
1570 }
1571
1572 #ifdef CONFIG_IOMMU_API
1573 int acpi_iommu_fwspec_init(struct device *dev, u32 id,
1574                            struct fwnode_handle *fwnode,
1575                            const struct iommu_ops *ops)
1576 {
1577         int ret = iommu_fwspec_init(dev, fwnode, ops);
1578
1579         if (!ret)
1580                 ret = iommu_fwspec_add_ids(dev, &id, 1);
1581
1582         return ret;
1583 }
1584
1585 static inline const struct iommu_ops *acpi_iommu_fwspec_ops(struct device *dev)
1586 {
1587         struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
1588
1589         return fwspec ? fwspec->ops : NULL;
1590 }
1591
1592 static const struct iommu_ops *acpi_iommu_configure_id(struct device *dev,
1593                                                        const u32 *id_in)
1594 {
1595         int err;
1596         const struct iommu_ops *ops;
1597
1598         /*
1599          * If we already translated the fwspec there is nothing left to do,
1600          * return the iommu_ops.
1601          */
1602         ops = acpi_iommu_fwspec_ops(dev);
1603         if (ops)
1604                 return ops;
1605
1606         err = iort_iommu_configure_id(dev, id_in);
1607         if (err && err != -EPROBE_DEFER)
1608                 err = viot_iommu_configure(dev);
1609
1610         /*
1611          * If we have reason to believe the IOMMU driver missed the initial
1612          * iommu_probe_device() call for dev, replay it to get things in order.
1613          */
1614         if (!err && dev->bus && !device_iommu_mapped(dev))
1615                 err = iommu_probe_device(dev);
1616
1617         /* Ignore all other errors apart from EPROBE_DEFER */
1618         if (err == -EPROBE_DEFER) {
1619                 return ERR_PTR(err);
1620         } else if (err) {
1621                 dev_dbg(dev, "Adding to IOMMU failed: %d\n", err);
1622                 return NULL;
1623         }
1624         return acpi_iommu_fwspec_ops(dev);
1625 }
1626
1627 #else /* !CONFIG_IOMMU_API */
1628
1629 int acpi_iommu_fwspec_init(struct device *dev, u32 id,
1630                            struct fwnode_handle *fwnode,
1631                            const struct iommu_ops *ops)
1632 {
1633         return -ENODEV;
1634 }
1635
1636 static const struct iommu_ops *acpi_iommu_configure_id(struct device *dev,
1637                                                        const u32 *id_in)
1638 {
1639         return NULL;
1640 }
1641
1642 #endif /* !CONFIG_IOMMU_API */
1643
1644 /**
1645  * acpi_dma_configure_id - Set-up DMA configuration for the device.
1646  * @dev: The pointer to the device
1647  * @attr: device dma attributes
1648  * @input_id: input device id const value pointer
1649  */
1650 int acpi_dma_configure_id(struct device *dev, enum dev_dma_attr attr,
1651                           const u32 *input_id)
1652 {
1653         const struct iommu_ops *iommu;
1654         u64 dma_addr = 0, size = 0;
1655
1656         if (attr == DEV_DMA_NOT_SUPPORTED) {
1657                 set_dma_ops(dev, &dma_dummy_ops);
1658                 return 0;
1659         }
1660
1661         acpi_arch_dma_setup(dev, &dma_addr, &size);
1662
1663         iommu = acpi_iommu_configure_id(dev, input_id);
1664         if (PTR_ERR(iommu) == -EPROBE_DEFER)
1665                 return -EPROBE_DEFER;
1666
1667         arch_setup_dma_ops(dev, dma_addr, size,
1668                                 iommu, attr == DEV_DMA_COHERENT);
1669
1670         return 0;
1671 }
1672 EXPORT_SYMBOL_GPL(acpi_dma_configure_id);
1673
1674 static void acpi_init_coherency(struct acpi_device *adev)
1675 {
1676         unsigned long long cca = 0;
1677         acpi_status status;
1678         struct acpi_device *parent = adev->parent;
1679
1680         if (parent && parent->flags.cca_seen) {
1681                 /*
1682                  * From ACPI spec, OSPM will ignore _CCA if an ancestor
1683                  * already saw one.
1684                  */
1685                 adev->flags.cca_seen = 1;
1686                 cca = parent->flags.coherent_dma;
1687         } else {
1688                 status = acpi_evaluate_integer(adev->handle, "_CCA",
1689                                                NULL, &cca);
1690                 if (ACPI_SUCCESS(status))
1691                         adev->flags.cca_seen = 1;
1692                 else if (!IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED))
1693                         /*
1694                          * If architecture does not specify that _CCA is
1695                          * required for DMA-able devices (e.g. x86),
1696                          * we default to _CCA=1.
1697                          */
1698                         cca = 1;
1699                 else
1700                         acpi_handle_debug(adev->handle,
1701                                           "ACPI device is missing _CCA.\n");
1702         }
1703
1704         adev->flags.coherent_dma = cca;
1705 }
1706
1707 static int acpi_check_serial_bus_slave(struct acpi_resource *ares, void *data)
1708 {
1709         bool *is_serial_bus_slave_p = data;
1710
1711         if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
1712                 return 1;
1713
1714         *is_serial_bus_slave_p = true;
1715
1716          /* no need to do more checking */
1717         return -1;
1718 }
1719
1720 static bool acpi_is_indirect_io_slave(struct acpi_device *device)
1721 {
1722         struct acpi_device *parent = device->parent;
1723         static const struct acpi_device_id indirect_io_hosts[] = {
1724                 {"HISI0191", 0},
1725                 {}
1726         };
1727
1728         return parent && !acpi_match_device_ids(parent, indirect_io_hosts);
1729 }
1730
1731 static bool acpi_device_enumeration_by_parent(struct acpi_device *device)
1732 {
1733         struct list_head resource_list;
1734         bool is_serial_bus_slave = false;
1735         static const struct acpi_device_id ignore_serial_bus_ids[] = {
1736         /*
1737          * These devices have multiple I2cSerialBus resources and an i2c-client
1738          * must be instantiated for each, each with its own i2c_device_id.
1739          * Normally we only instantiate an i2c-client for the first resource,
1740          * using the ACPI HID as id. These special cases are handled by the
1741          * drivers/platform/x86/i2c-multi-instantiate.c driver, which knows
1742          * which i2c_device_id to use for each resource.
1743          */
1744                 {"BSG1160", },
1745                 {"BSG2150", },
1746                 {"INT33FE", },
1747                 {"INT3515", },
1748         /*
1749          * HIDs of device with an UartSerialBusV2 resource for which userspace
1750          * expects a regular tty cdev to be created (instead of the in kernel
1751          * serdev) and which have a kernel driver which expects a platform_dev
1752          * such as the rfkill-gpio driver.
1753          */
1754                 {"BCM4752", },
1755                 {"LNV4752", },
1756                 {}
1757         };
1758
1759         if (acpi_is_indirect_io_slave(device))
1760                 return true;
1761
1762         /* Macs use device properties in lieu of _CRS resources */
1763         if (x86_apple_machine &&
1764             (fwnode_property_present(&device->fwnode, "spiSclkPeriod") ||
1765              fwnode_property_present(&device->fwnode, "i2cAddress") ||
1766              fwnode_property_present(&device->fwnode, "baud")))
1767                 return true;
1768
1769         if (!acpi_match_device_ids(device, ignore_serial_bus_ids))
1770                 return false;
1771
1772         INIT_LIST_HEAD(&resource_list);
1773         acpi_dev_get_resources(device, &resource_list,
1774                                acpi_check_serial_bus_slave,
1775                                &is_serial_bus_slave);
1776         acpi_dev_free_resource_list(&resource_list);
1777
1778         return is_serial_bus_slave;
1779 }
1780
1781 void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,
1782                              int type)
1783 {
1784         INIT_LIST_HEAD(&device->pnp.ids);
1785         device->device_type = type;
1786         device->handle = handle;
1787         device->parent = acpi_bus_get_parent(handle);
1788         fwnode_init(&device->fwnode, &acpi_device_fwnode_ops);
1789         acpi_set_device_status(device, ACPI_STA_DEFAULT);
1790         acpi_device_get_busid(device);
1791         acpi_set_pnp_ids(handle, &device->pnp, type);
1792         acpi_init_properties(device);
1793         acpi_bus_get_flags(device);
1794         device->flags.match_driver = false;
1795         device->flags.initialized = true;
1796         device->flags.enumeration_by_parent =
1797                 acpi_device_enumeration_by_parent(device);
1798         acpi_device_clear_enumerated(device);
1799         device_initialize(&device->dev);
1800         dev_set_uevent_suppress(&device->dev, true);
1801         acpi_init_coherency(device);
1802 }
1803
1804 static void acpi_scan_dep_init(struct acpi_device *adev)
1805 {
1806         struct acpi_dep_data *dep;
1807
1808         list_for_each_entry(dep, &acpi_dep_list, node) {
1809                 if (dep->consumer == adev->handle) {
1810                         if (dep->honor_dep)
1811                                 adev->flags.honor_deps = 1;
1812
1813                         adev->dep_unmet++;
1814                 }
1815         }
1816 }
1817
1818 void acpi_device_add_finalize(struct acpi_device *device)
1819 {
1820         dev_set_uevent_suppress(&device->dev, false);
1821         kobject_uevent(&device->dev.kobj, KOBJ_ADD);
1822 }
1823
1824 static void acpi_scan_init_status(struct acpi_device *adev)
1825 {
1826         if (acpi_bus_get_status(adev))
1827                 acpi_set_device_status(adev, 0);
1828 }
1829
1830 static int acpi_add_single_object(struct acpi_device **child,
1831                                   acpi_handle handle, int type, bool dep_init)
1832 {
1833         struct acpi_device *device;
1834         bool release_dep_lock = false;
1835         int result;
1836
1837         device = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
1838         if (!device)
1839                 return -ENOMEM;
1840
1841         acpi_init_device_object(device, handle, type);
1842         /*
1843          * Getting the status is delayed till here so that we can call
1844          * acpi_bus_get_status() and use its quirk handling.  Note that
1845          * this must be done before the get power-/wakeup_dev-flags calls.
1846          */
1847         if (type == ACPI_BUS_TYPE_DEVICE || type == ACPI_BUS_TYPE_PROCESSOR) {
1848                 if (dep_init) {
1849                         mutex_lock(&acpi_dep_list_lock);
1850                         /*
1851                          * Hold the lock until the acpi_tie_acpi_dev() call
1852                          * below to prevent concurrent acpi_scan_clear_dep()
1853                          * from deleting a dependency list entry without
1854                          * updating dep_unmet for the device.
1855                          */
1856                         release_dep_lock = true;
1857                         acpi_scan_dep_init(device);
1858                 }
1859                 acpi_scan_init_status(device);
1860         }
1861
1862         acpi_bus_get_power_flags(device);
1863         acpi_bus_get_wakeup_device_flags(device);
1864
1865         result = acpi_tie_acpi_dev(device);
1866
1867         if (release_dep_lock)
1868                 mutex_unlock(&acpi_dep_list_lock);
1869
1870         if (!result)
1871                 result = __acpi_device_add(device, acpi_device_release);
1872
1873         if (result) {
1874                 acpi_device_release(&device->dev);
1875                 return result;
1876         }
1877
1878         acpi_power_add_remove_device(device, true);
1879         acpi_device_add_finalize(device);
1880
1881         acpi_handle_debug(handle, "Added as %s, parent %s\n",
1882                           dev_name(&device->dev), device->parent ?
1883                                 dev_name(&device->parent->dev) : "(null)");
1884
1885         *child = device;
1886         return 0;
1887 }
1888
1889 static acpi_status acpi_get_resource_memory(struct acpi_resource *ares,
1890                                             void *context)
1891 {
1892         struct resource *res = context;
1893
1894         if (acpi_dev_resource_memory(ares, res))
1895                 return AE_CTRL_TERMINATE;
1896
1897         return AE_OK;
1898 }
1899
1900 static bool acpi_device_should_be_hidden(acpi_handle handle)
1901 {
1902         acpi_status status;
1903         struct resource res;
1904
1905         /* Check if it should ignore the UART device */
1906         if (!(spcr_uart_addr && acpi_has_method(handle, METHOD_NAME__CRS)))
1907                 return false;
1908
1909         /*
1910          * The UART device described in SPCR table is assumed to have only one
1911          * memory resource present. So we only look for the first one here.
1912          */
1913         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1914                                      acpi_get_resource_memory, &res);
1915         if (ACPI_FAILURE(status) || res.start != spcr_uart_addr)
1916                 return false;
1917
1918         acpi_handle_info(handle, "The UART device @%pa in SPCR table will be hidden\n",
1919                          &res.start);
1920
1921         return true;
1922 }
1923
1924 bool acpi_device_is_present(const struct acpi_device *adev)
1925 {
1926         return adev->status.present || adev->status.functional;
1927 }
1928
1929 static bool acpi_scan_handler_matching(struct acpi_scan_handler *handler,
1930                                        const char *idstr,
1931                                        const struct acpi_device_id **matchid)
1932 {
1933         const struct acpi_device_id *devid;
1934
1935         if (handler->match)
1936                 return handler->match(idstr, matchid);
1937
1938         for (devid = handler->ids; devid->id[0]; devid++)
1939                 if (!strcmp((char *)devid->id, idstr)) {
1940                         if (matchid)
1941                                 *matchid = devid;
1942
1943                         return true;
1944                 }
1945
1946         return false;
1947 }
1948
1949 static struct acpi_scan_handler *acpi_scan_match_handler(const char *idstr,
1950                                         const struct acpi_device_id **matchid)
1951 {
1952         struct acpi_scan_handler *handler;
1953
1954         list_for_each_entry(handler, &acpi_scan_handlers_list, list_node)
1955                 if (acpi_scan_handler_matching(handler, idstr, matchid))
1956                         return handler;
1957
1958         return NULL;
1959 }
1960
1961 void acpi_scan_hotplug_enabled(struct acpi_hotplug_profile *hotplug, bool val)
1962 {
1963         if (!!hotplug->enabled == !!val)
1964                 return;
1965
1966         mutex_lock(&acpi_scan_lock);
1967
1968         hotplug->enabled = val;
1969
1970         mutex_unlock(&acpi_scan_lock);
1971 }
1972
1973 static void acpi_scan_init_hotplug(struct acpi_device *adev)
1974 {
1975         struct acpi_hardware_id *hwid;
1976
1977         if (acpi_dock_match(adev->handle) || is_ejectable_bay(adev)) {
1978                 acpi_dock_add(adev);
1979                 return;
1980         }
1981         list_for_each_entry(hwid, &adev->pnp.ids, list) {
1982                 struct acpi_scan_handler *handler;
1983
1984                 handler = acpi_scan_match_handler(hwid->id, NULL);
1985                 if (handler) {
1986                         adev->flags.hotplug_notify = true;
1987                         break;
1988                 }
1989         }
1990 }
1991
1992 static u32 acpi_scan_check_dep(acpi_handle handle, bool check_dep)
1993 {
1994         struct acpi_handle_list dep_devices;
1995         acpi_status status;
1996         u32 count;
1997         int i;
1998
1999         /*
2000          * Check for _HID here to avoid deferring the enumeration of:
2001          * 1. PCI devices.
2002          * 2. ACPI nodes describing USB ports.
2003          * Still, checking for _HID catches more then just these cases ...
2004          */
2005         if (!check_dep || !acpi_has_method(handle, "_DEP") ||
2006             !acpi_has_method(handle, "_HID"))
2007                 return 0;
2008
2009         status = acpi_evaluate_reference(handle, "_DEP", NULL, &dep_devices);
2010         if (ACPI_FAILURE(status)) {
2011                 acpi_handle_debug(handle, "Failed to evaluate _DEP.\n");
2012                 return 0;
2013         }
2014
2015         for (count = 0, i = 0; i < dep_devices.count; i++) {
2016                 struct acpi_device_info *info;
2017                 struct acpi_dep_data *dep;
2018                 bool skip, honor_dep;
2019
2020                 status = acpi_get_object_info(dep_devices.handles[i], &info);
2021                 if (ACPI_FAILURE(status)) {
2022                         acpi_handle_debug(handle, "Error reading _DEP device info\n");
2023                         continue;
2024                 }
2025
2026                 skip = acpi_info_matches_ids(info, acpi_ignore_dep_ids);
2027                 honor_dep = acpi_info_matches_ids(info, acpi_honor_dep_ids);
2028                 kfree(info);
2029
2030                 if (skip)
2031                         continue;
2032
2033                 dep = kzalloc(sizeof(*dep), GFP_KERNEL);
2034                 if (!dep)
2035                         continue;
2036
2037                 count++;
2038
2039                 dep->supplier = dep_devices.handles[i];
2040                 dep->consumer = handle;
2041                 dep->honor_dep = honor_dep;
2042
2043                 mutex_lock(&acpi_dep_list_lock);
2044                 list_add_tail(&dep->node , &acpi_dep_list);
2045                 mutex_unlock(&acpi_dep_list_lock);
2046         }
2047
2048         return count;
2049 }
2050
2051 static bool acpi_bus_scan_second_pass;
2052
2053 static acpi_status acpi_bus_check_add(acpi_handle handle, bool check_dep,
2054                                       struct acpi_device **adev_p)
2055 {
2056         struct acpi_device *device = acpi_fetch_acpi_dev(handle);
2057         acpi_object_type acpi_type;
2058         int type;
2059
2060         if (device)
2061                 goto out;
2062
2063         if (ACPI_FAILURE(acpi_get_type(handle, &acpi_type)))
2064                 return AE_OK;
2065
2066         switch (acpi_type) {
2067         case ACPI_TYPE_DEVICE:
2068                 if (acpi_device_should_be_hidden(handle))
2069                         return AE_OK;
2070
2071                 /* Bail out if there are dependencies. */
2072                 if (acpi_scan_check_dep(handle, check_dep) > 0) {
2073                         acpi_bus_scan_second_pass = true;
2074                         return AE_CTRL_DEPTH;
2075                 }
2076
2077                 fallthrough;
2078         case ACPI_TYPE_ANY:     /* for ACPI_ROOT_OBJECT */
2079                 type = ACPI_BUS_TYPE_DEVICE;
2080                 break;
2081
2082         case ACPI_TYPE_PROCESSOR:
2083                 type = ACPI_BUS_TYPE_PROCESSOR;
2084                 break;
2085
2086         case ACPI_TYPE_THERMAL:
2087                 type = ACPI_BUS_TYPE_THERMAL;
2088                 break;
2089
2090         case ACPI_TYPE_POWER:
2091                 acpi_add_power_resource(handle);
2092                 fallthrough;
2093         default:
2094                 return AE_OK;
2095         }
2096
2097         /*
2098          * If check_dep is true at this point, the device has no dependencies,
2099          * or the creation of the device object would have been postponed above.
2100          */
2101         acpi_add_single_object(&device, handle, type, !check_dep);
2102         if (!device)
2103                 return AE_CTRL_DEPTH;
2104
2105         acpi_scan_init_hotplug(device);
2106
2107 out:
2108         if (!*adev_p)
2109                 *adev_p = device;
2110
2111         return AE_OK;
2112 }
2113
2114 static acpi_status acpi_bus_check_add_1(acpi_handle handle, u32 lvl_not_used,
2115                                         void *not_used, void **ret_p)
2116 {
2117         return acpi_bus_check_add(handle, true, (struct acpi_device **)ret_p);
2118 }
2119
2120 static acpi_status acpi_bus_check_add_2(acpi_handle handle, u32 lvl_not_used,
2121                                         void *not_used, void **ret_p)
2122 {
2123         return acpi_bus_check_add(handle, false, (struct acpi_device **)ret_p);
2124 }
2125
2126 static void acpi_default_enumeration(struct acpi_device *device)
2127 {
2128         /*
2129          * Do not enumerate devices with enumeration_by_parent flag set as
2130          * they will be enumerated by their respective parents.
2131          */
2132         if (!device->flags.enumeration_by_parent) {
2133                 acpi_create_platform_device(device, NULL);
2134                 acpi_device_set_enumerated(device);
2135         } else {
2136                 blocking_notifier_call_chain(&acpi_reconfig_chain,
2137                                              ACPI_RECONFIG_DEVICE_ADD, device);
2138         }
2139 }
2140
2141 static const struct acpi_device_id generic_device_ids[] = {
2142         {ACPI_DT_NAMESPACE_HID, },
2143         {"", },
2144 };
2145
2146 static int acpi_generic_device_attach(struct acpi_device *adev,
2147                                       const struct acpi_device_id *not_used)
2148 {
2149         /*
2150          * Since ACPI_DT_NAMESPACE_HID is the only ID handled here, the test
2151          * below can be unconditional.
2152          */
2153         if (adev->data.of_compatible)
2154                 acpi_default_enumeration(adev);
2155
2156         return 1;
2157 }
2158
2159 static struct acpi_scan_handler generic_device_handler = {
2160         .ids = generic_device_ids,
2161         .attach = acpi_generic_device_attach,
2162 };
2163
2164 static int acpi_scan_attach_handler(struct acpi_device *device)
2165 {
2166         struct acpi_hardware_id *hwid;
2167         int ret = 0;
2168
2169         list_for_each_entry(hwid, &device->pnp.ids, list) {
2170                 const struct acpi_device_id *devid;
2171                 struct acpi_scan_handler *handler;
2172
2173                 handler = acpi_scan_match_handler(hwid->id, &devid);
2174                 if (handler) {
2175                         if (!handler->attach) {
2176                                 device->pnp.type.platform_id = 0;
2177                                 continue;
2178                         }
2179                         device->handler = handler;
2180                         ret = handler->attach(device, devid);
2181                         if (ret > 0)
2182                                 break;
2183
2184                         device->handler = NULL;
2185                         if (ret < 0)
2186                                 break;
2187                 }
2188         }
2189
2190         return ret;
2191 }
2192
2193 static void acpi_bus_attach(struct acpi_device *device, bool first_pass)
2194 {
2195         struct acpi_device *child;
2196         bool skip = !first_pass && device->flags.visited;
2197         acpi_handle ejd;
2198         int ret;
2199
2200         if (skip)
2201                 goto ok;
2202
2203         if (ACPI_SUCCESS(acpi_bus_get_ejd(device->handle, &ejd)))
2204                 register_dock_dependent_device(device, ejd);
2205
2206         acpi_bus_get_status(device);
2207         /* Skip devices that are not ready for enumeration (e.g. not present) */
2208         if (!acpi_dev_ready_for_enumeration(device)) {
2209                 device->flags.initialized = false;
2210                 acpi_device_clear_enumerated(device);
2211                 device->flags.power_manageable = 0;
2212                 return;
2213         }
2214         if (device->handler)
2215                 goto ok;
2216
2217         if (!device->flags.initialized) {
2218                 device->flags.power_manageable =
2219                         device->power.states[ACPI_STATE_D0].flags.valid;
2220                 if (acpi_bus_init_power(device))
2221                         device->flags.power_manageable = 0;
2222
2223                 device->flags.initialized = true;
2224         } else if (device->flags.visited) {
2225                 goto ok;
2226         }
2227
2228         ret = acpi_scan_attach_handler(device);
2229         if (ret < 0)
2230                 return;
2231
2232         device->flags.match_driver = true;
2233         if (ret > 0 && !device->flags.enumeration_by_parent) {
2234                 acpi_device_set_enumerated(device);
2235                 goto ok;
2236         }
2237
2238         ret = device_attach(&device->dev);
2239         if (ret < 0)
2240                 return;
2241
2242         if (device->pnp.type.platform_id || device->flags.enumeration_by_parent)
2243                 acpi_default_enumeration(device);
2244         else
2245                 acpi_device_set_enumerated(device);
2246
2247  ok:
2248         list_for_each_entry(child, &device->children, node)
2249                 acpi_bus_attach(child, first_pass);
2250
2251         if (!skip && device->handler && device->handler->hotplug.notify_online)
2252                 device->handler->hotplug.notify_online(device);
2253 }
2254
2255 static int acpi_dev_get_first_consumer_dev_cb(struct acpi_dep_data *dep, void *data)
2256 {
2257         struct acpi_device *adev;
2258
2259         adev = acpi_bus_get_acpi_device(dep->consumer);
2260         if (adev) {
2261                 *(struct acpi_device **)data = adev;
2262                 return 1;
2263         }
2264         /* Continue parsing if the device object is not present. */
2265         return 0;
2266 }
2267
2268 struct acpi_scan_clear_dep_work {
2269         struct work_struct work;
2270         struct acpi_device *adev;
2271 };
2272
2273 static void acpi_scan_clear_dep_fn(struct work_struct *work)
2274 {
2275         struct acpi_scan_clear_dep_work *cdw;
2276
2277         cdw = container_of(work, struct acpi_scan_clear_dep_work, work);
2278
2279         acpi_scan_lock_acquire();
2280         acpi_bus_attach(cdw->adev, true);
2281         acpi_scan_lock_release();
2282
2283         acpi_dev_put(cdw->adev);
2284         kfree(cdw);
2285 }
2286
2287 static bool acpi_scan_clear_dep_queue(struct acpi_device *adev)
2288 {
2289         struct acpi_scan_clear_dep_work *cdw;
2290
2291         if (adev->dep_unmet)
2292                 return false;
2293
2294         cdw = kmalloc(sizeof(*cdw), GFP_KERNEL);
2295         if (!cdw)
2296                 return false;
2297
2298         cdw->adev = adev;
2299         INIT_WORK(&cdw->work, acpi_scan_clear_dep_fn);
2300         /*
2301          * Since the work function may block on the lock until the entire
2302          * initial enumeration of devices is complete, put it into the unbound
2303          * workqueue.
2304          */
2305         queue_work(system_unbound_wq, &cdw->work);
2306
2307         return true;
2308 }
2309
2310 static int acpi_scan_clear_dep(struct acpi_dep_data *dep, void *data)
2311 {
2312         struct acpi_device *adev = acpi_bus_get_acpi_device(dep->consumer);
2313
2314         if (adev) {
2315                 adev->dep_unmet--;
2316                 if (!acpi_scan_clear_dep_queue(adev))
2317                         acpi_dev_put(adev);
2318         }
2319
2320         list_del(&dep->node);
2321         kfree(dep);
2322
2323         return 0;
2324 }
2325
2326 /**
2327  * acpi_walk_dep_device_list - Apply a callback to every entry in acpi_dep_list
2328  * @handle:     The ACPI handle of the supplier device
2329  * @callback:   Pointer to the callback function to apply
2330  * @data:       Pointer to some data to pass to the callback
2331  *
2332  * The return value of the callback determines this function's behaviour. If 0
2333  * is returned we continue to iterate over acpi_dep_list. If a positive value
2334  * is returned then the loop is broken but this function returns 0. If a
2335  * negative value is returned by the callback then the loop is broken and that
2336  * value is returned as the final error.
2337  */
2338 static int acpi_walk_dep_device_list(acpi_handle handle,
2339                                 int (*callback)(struct acpi_dep_data *, void *),
2340                                 void *data)
2341 {
2342         struct acpi_dep_data *dep, *tmp;
2343         int ret = 0;
2344
2345         mutex_lock(&acpi_dep_list_lock);
2346         list_for_each_entry_safe(dep, tmp, &acpi_dep_list, node) {
2347                 if (dep->supplier == handle) {
2348                         ret = callback(dep, data);
2349                         if (ret)
2350                                 break;
2351                 }
2352         }
2353         mutex_unlock(&acpi_dep_list_lock);
2354
2355         return ret > 0 ? 0 : ret;
2356 }
2357
2358 /**
2359  * acpi_dev_clear_dependencies - Inform consumers that the device is now active
2360  * @supplier: Pointer to the supplier &struct acpi_device
2361  *
2362  * Clear dependencies on the given device.
2363  */
2364 void acpi_dev_clear_dependencies(struct acpi_device *supplier)
2365 {
2366         acpi_walk_dep_device_list(supplier->handle, acpi_scan_clear_dep, NULL);
2367 }
2368 EXPORT_SYMBOL_GPL(acpi_dev_clear_dependencies);
2369
2370 /**
2371  * acpi_dev_ready_for_enumeration - Check if the ACPI device is ready for enumeration
2372  * @device: Pointer to the &struct acpi_device to check
2373  *
2374  * Check if the device is present and has no unmet dependencies.
2375  *
2376  * Return true if the device is ready for enumeratino. Otherwise, return false.
2377  */
2378 bool acpi_dev_ready_for_enumeration(const struct acpi_device *device)
2379 {
2380         if (device->flags.honor_deps && device->dep_unmet)
2381                 return false;
2382
2383         return acpi_device_is_present(device);
2384 }
2385 EXPORT_SYMBOL_GPL(acpi_dev_ready_for_enumeration);
2386
2387 /**
2388  * acpi_dev_get_first_consumer_dev - Return ACPI device dependent on @supplier
2389  * @supplier: Pointer to the dependee device
2390  *
2391  * Returns the first &struct acpi_device which declares itself dependent on
2392  * @supplier via the _DEP buffer, parsed from the acpi_dep_list.
2393  *
2394  * The caller is responsible for putting the reference to adev when it is no
2395  * longer needed.
2396  */
2397 struct acpi_device *acpi_dev_get_first_consumer_dev(struct acpi_device *supplier)
2398 {
2399         struct acpi_device *adev = NULL;
2400
2401         acpi_walk_dep_device_list(supplier->handle,
2402                                   acpi_dev_get_first_consumer_dev_cb, &adev);
2403
2404         return adev;
2405 }
2406 EXPORT_SYMBOL_GPL(acpi_dev_get_first_consumer_dev);
2407
2408 /**
2409  * acpi_bus_scan - Add ACPI device node objects in a given namespace scope.
2410  * @handle: Root of the namespace scope to scan.
2411  *
2412  * Scan a given ACPI tree (probably recently hot-plugged) and create and add
2413  * found devices.
2414  *
2415  * If no devices were found, -ENODEV is returned, but it does not mean that
2416  * there has been a real error.  There just have been no suitable ACPI objects
2417  * in the table trunk from which the kernel could create a device and add an
2418  * appropriate driver.
2419  *
2420  * Must be called under acpi_scan_lock.
2421  */
2422 int acpi_bus_scan(acpi_handle handle)
2423 {
2424         struct acpi_device *device = NULL;
2425
2426         acpi_bus_scan_second_pass = false;
2427
2428         /* Pass 1: Avoid enumerating devices with missing dependencies. */
2429
2430         if (ACPI_SUCCESS(acpi_bus_check_add(handle, true, &device)))
2431                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
2432                                     acpi_bus_check_add_1, NULL, NULL,
2433                                     (void **)&device);
2434
2435         if (!device)
2436                 return -ENODEV;
2437
2438         acpi_bus_attach(device, true);
2439
2440         if (!acpi_bus_scan_second_pass)
2441                 return 0;
2442
2443         /* Pass 2: Enumerate all of the remaining devices. */
2444
2445         device = NULL;
2446
2447         if (ACPI_SUCCESS(acpi_bus_check_add(handle, false, &device)))
2448                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
2449                                     acpi_bus_check_add_2, NULL, NULL,
2450                                     (void **)&device);
2451
2452         acpi_bus_attach(device, false);
2453
2454         return 0;
2455 }
2456 EXPORT_SYMBOL(acpi_bus_scan);
2457
2458 /**
2459  * acpi_bus_trim - Detach scan handlers and drivers from ACPI device objects.
2460  * @adev: Root of the ACPI namespace scope to walk.
2461  *
2462  * Must be called under acpi_scan_lock.
2463  */
2464 void acpi_bus_trim(struct acpi_device *adev)
2465 {
2466         struct acpi_scan_handler *handler = adev->handler;
2467         struct acpi_device *child;
2468
2469         list_for_each_entry_reverse(child, &adev->children, node)
2470                 acpi_bus_trim(child);
2471
2472         adev->flags.match_driver = false;
2473         if (handler) {
2474                 if (handler->detach)
2475                         handler->detach(adev);
2476
2477                 adev->handler = NULL;
2478         } else {
2479                 device_release_driver(&adev->dev);
2480         }
2481         /*
2482          * Most likely, the device is going away, so put it into D3cold before
2483          * that.
2484          */
2485         acpi_device_set_power(adev, ACPI_STATE_D3_COLD);
2486         adev->flags.initialized = false;
2487         acpi_device_clear_enumerated(adev);
2488 }
2489 EXPORT_SYMBOL_GPL(acpi_bus_trim);
2490
2491 int acpi_bus_register_early_device(int type)
2492 {
2493         struct acpi_device *device = NULL;
2494         int result;
2495
2496         result = acpi_add_single_object(&device, NULL, type, false);
2497         if (result)
2498                 return result;
2499
2500         device->flags.match_driver = true;
2501         return device_attach(&device->dev);
2502 }
2503 EXPORT_SYMBOL_GPL(acpi_bus_register_early_device);
2504
2505 static void acpi_bus_scan_fixed(void)
2506 {
2507         if (!(acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON)) {
2508                 struct acpi_device *adev = NULL;
2509
2510                 acpi_add_single_object(&adev, NULL, ACPI_BUS_TYPE_POWER_BUTTON,
2511                                        false);
2512                 if (adev) {
2513                         adev->flags.match_driver = true;
2514                         if (device_attach(&adev->dev) >= 0)
2515                                 device_init_wakeup(&adev->dev, true);
2516                         else
2517                                 dev_dbg(&adev->dev, "No driver\n");
2518                 }
2519         }
2520
2521         if (!(acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON)) {
2522                 struct acpi_device *adev = NULL;
2523
2524                 acpi_add_single_object(&adev, NULL, ACPI_BUS_TYPE_SLEEP_BUTTON,
2525                                        false);
2526                 if (adev) {
2527                         adev->flags.match_driver = true;
2528                         if (device_attach(&adev->dev) < 0)
2529                                 dev_dbg(&adev->dev, "No driver\n");
2530                 }
2531         }
2532 }
2533
2534 static void __init acpi_get_spcr_uart_addr(void)
2535 {
2536         acpi_status status;
2537         struct acpi_table_spcr *spcr_ptr;
2538
2539         status = acpi_get_table(ACPI_SIG_SPCR, 0,
2540                                 (struct acpi_table_header **)&spcr_ptr);
2541         if (ACPI_FAILURE(status)) {
2542                 pr_warn("STAO table present, but SPCR is missing\n");
2543                 return;
2544         }
2545
2546         spcr_uart_addr = spcr_ptr->serial_port.address;
2547         acpi_put_table((struct acpi_table_header *)spcr_ptr);
2548 }
2549
2550 static bool acpi_scan_initialized;
2551
2552 void __init acpi_scan_init(void)
2553 {
2554         acpi_status status;
2555         struct acpi_table_stao *stao_ptr;
2556
2557         acpi_pci_root_init();
2558         acpi_pci_link_init();
2559         acpi_processor_init();
2560         acpi_platform_init();
2561         acpi_lpss_init();
2562         acpi_apd_init();
2563         acpi_cmos_rtc_init();
2564         acpi_container_init();
2565         acpi_memory_hotplug_init();
2566         acpi_watchdog_init();
2567         acpi_pnp_init();
2568         acpi_int340x_thermal_init();
2569         acpi_amba_init();
2570         acpi_init_lpit();
2571
2572         acpi_scan_add_handler(&generic_device_handler);
2573
2574         /*
2575          * If there is STAO table, check whether it needs to ignore the UART
2576          * device in SPCR table.
2577          */
2578         status = acpi_get_table(ACPI_SIG_STAO, 0,
2579                                 (struct acpi_table_header **)&stao_ptr);
2580         if (ACPI_SUCCESS(status)) {
2581                 if (stao_ptr->header.length > sizeof(struct acpi_table_stao))
2582                         pr_info("STAO Name List not yet supported.\n");
2583
2584                 if (stao_ptr->ignore_uart)
2585                         acpi_get_spcr_uart_addr();
2586
2587                 acpi_put_table((struct acpi_table_header *)stao_ptr);
2588         }
2589
2590         acpi_gpe_apply_masked_gpes();
2591         acpi_update_all_gpes();
2592
2593         /*
2594          * Although we call __add_memory() that is documented to require the
2595          * device_hotplug_lock, it is not necessary here because this is an
2596          * early code when userspace or any other code path cannot trigger
2597          * hotplug/hotunplug operations.
2598          */
2599         mutex_lock(&acpi_scan_lock);
2600         /*
2601          * Enumerate devices in the ACPI namespace.
2602          */
2603         if (acpi_bus_scan(ACPI_ROOT_OBJECT))
2604                 goto unlock;
2605
2606         acpi_root = acpi_fetch_acpi_dev(ACPI_ROOT_OBJECT);
2607         if (!acpi_root)
2608                 goto unlock;
2609
2610         /* Fixed feature devices do not exist on HW-reduced platform */
2611         if (!acpi_gbl_reduced_hardware)
2612                 acpi_bus_scan_fixed();
2613
2614         acpi_turn_off_unused_power_resources();
2615
2616         acpi_scan_initialized = true;
2617
2618 unlock:
2619         mutex_unlock(&acpi_scan_lock);
2620 }
2621
2622 static struct acpi_probe_entry *ape;
2623 static int acpi_probe_count;
2624 static DEFINE_MUTEX(acpi_probe_mutex);
2625
2626 static int __init acpi_match_madt(union acpi_subtable_headers *header,
2627                                   const unsigned long end)
2628 {
2629         if (!ape->subtable_valid || ape->subtable_valid(&header->common, ape))
2630                 if (!ape->probe_subtbl(header, end))
2631                         acpi_probe_count++;
2632
2633         return 0;
2634 }
2635
2636 int __init __acpi_probe_device_table(struct acpi_probe_entry *ap_head, int nr)
2637 {
2638         int count = 0;
2639
2640         if (acpi_disabled)
2641                 return 0;
2642
2643         mutex_lock(&acpi_probe_mutex);
2644         for (ape = ap_head; nr; ape++, nr--) {
2645                 if (ACPI_COMPARE_NAMESEG(ACPI_SIG_MADT, ape->id)) {
2646                         acpi_probe_count = 0;
2647                         acpi_table_parse_madt(ape->type, acpi_match_madt, 0);
2648                         count += acpi_probe_count;
2649                 } else {
2650                         int res;
2651                         res = acpi_table_parse(ape->id, ape->probe_table);
2652                         if (!res)
2653                                 count++;
2654                 }
2655         }
2656         mutex_unlock(&acpi_probe_mutex);
2657
2658         return count;
2659 }
2660
2661 static void acpi_table_events_fn(struct work_struct *work)
2662 {
2663         acpi_scan_lock_acquire();
2664         acpi_bus_scan(ACPI_ROOT_OBJECT);
2665         acpi_scan_lock_release();
2666
2667         kfree(work);
2668 }
2669
2670 void acpi_scan_table_notify(void)
2671 {
2672         struct work_struct *work;
2673
2674         if (!acpi_scan_initialized)
2675                 return;
2676
2677         work = kmalloc(sizeof(*work), GFP_KERNEL);
2678         if (!work)
2679                 return;
2680
2681         INIT_WORK(work, acpi_table_events_fn);
2682         schedule_work(work);
2683 }
2684
2685 int acpi_reconfig_notifier_register(struct notifier_block *nb)
2686 {
2687         return blocking_notifier_chain_register(&acpi_reconfig_chain, nb);
2688 }
2689 EXPORT_SYMBOL(acpi_reconfig_notifier_register);
2690
2691 int acpi_reconfig_notifier_unregister(struct notifier_block *nb)
2692 {
2693         return blocking_notifier_chain_unregister(&acpi_reconfig_chain, nb);
2694 }
2695 EXPORT_SYMBOL(acpi_reconfig_notifier_unregister);