drivers/acpi/scan.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * scan.c - support for transforming the ACPI namespace into individual objects
   4  */
   5
   6 #define pr_fmt(fmt) "ACPI: " fmt
   7
   8 #include <linux/module.h>
   9 #include <linux/init.h>
  10 #include <linux/slab.h>
  11 #include <linux/kernel.h>
  12 #include <linux/acpi.h>
  13 #include <linux/acpi_iort.h>
  14 #include <linux/acpi_viot.h>
  15 #include <linux/iommu.h>
  16 #include <linux/signal.h>
  17 #include <linux/kthread.h>
  18 #include <linux/dmi.h>
  19 #include <linux/dma-map-ops.h>
  20 #include <linux/platform_data/x86/apple.h>
  21 #include <linux/pgtable.h>
  22 #include <linux/crc32.h>
  23
  24 #include "internal.h"
  25
  26 extern struct acpi_device *acpi_root;
  27
  28 #define ACPI_BUS_CLASS                  "system_bus"
  29 #define ACPI_BUS_HID                    "LNXSYBUS"
  30 #define ACPI_BUS_DEVICE_NAME            "System Bus"
  31
  32 #define ACPI_IS_ROOT_DEVICE(device)    (!(device)->parent)
  33
  34 #define INVALID_ACPI_HANDLE     ((acpi_handle)empty_zero_page)
  35
  36 static const char *dummy_hid = "device";
  37
  38 static LIST_HEAD(acpi_dep_list);
  39 static DEFINE_MUTEX(acpi_dep_list_lock);
  40 LIST_HEAD(acpi_bus_id_list);
  41 static DEFINE_MUTEX(acpi_scan_lock);
  42 static LIST_HEAD(acpi_scan_handlers_list);
  43 DEFINE_MUTEX(acpi_device_lock);
  44 LIST_HEAD(acpi_wakeup_device_list);
  45 static DEFINE_MUTEX(acpi_hp_context_lock);
  46
  47 /*
  48  * The UART device described by the SPCR table is the only object which needs
  49  * special-casing. Everything else is covered by ACPI namespace paths in STAO
  50  * table.
  51  */
  52 static u64 spcr_uart_addr;
  53
  54 void acpi_scan_lock_acquire(void)
  55 {
  56         mutex_lock(&acpi_scan_lock);
  57 }
  58 EXPORT_SYMBOL_GPL(acpi_scan_lock_acquire);
  59
  60 void acpi_scan_lock_release(void)
  61 {
  62         mutex_unlock(&acpi_scan_lock);
  63 }
  64 EXPORT_SYMBOL_GPL(acpi_scan_lock_release);
  65
  66 void acpi_lock_hp_context(void)
  67 {
  68         mutex_lock(&acpi_hp_context_lock);
  69 }
  70
  71 void acpi_unlock_hp_context(void)
  72 {
  73         mutex_unlock(&acpi_hp_context_lock);
  74 }
  75
  76 void acpi_initialize_hp_context(struct acpi_device *adev,
  77                                 struct acpi_hotplug_context *hp,
  78                                 int (*notify)(struct acpi_device *, u32),
  79                                 void (*uevent)(struct acpi_device *, u32))
  80 {
  81         acpi_lock_hp_context();
  82         hp->notify = notify;
  83         hp->uevent = uevent;
  84         acpi_set_hp_context(adev, hp);
  85         acpi_unlock_hp_context();
  86 }
  87 EXPORT_SYMBOL_GPL(acpi_initialize_hp_context);
  88
  89 int acpi_scan_add_handler(struct acpi_scan_handler *handler)
  90 {
  91         if (!handler)
  92                 return -EINVAL;
  93
  94         list_add_tail(&handler->list_node, &acpi_scan_handlers_list);
  95         return 0;
  96 }
  97
  98 int acpi_scan_add_handler_with_hotplug(struct acpi_scan_handler *handler,
  99                                        const char *hotplug_profile_name)
 100 {
 101         int error;
 102
 103         error = acpi_scan_add_handler(handler);
 104         if (error)
 105                 return error;
 106
 107         acpi_sysfs_add_hotplug_profile(&handler->hotplug, hotplug_profile_name);
 108         return 0;
 109 }
 110
 111 bool acpi_scan_is_offline(struct acpi_device *adev, bool uevent)
 112 {
 113         struct acpi_device_physical_node *pn;
 114         bool offline = true;
 115         char *envp[] = { "EVENT=offline", NULL };
 116
 117         /*
 118          * acpi_container_offline() calls this for all of the container's
 119          * children under the container's physical_node_lock lock.
 120          */
 121         mutex_lock_nested(&adev->physical_node_lock, SINGLE_DEPTH_NESTING);
 122
 123         list_for_each_entry(pn, &adev->physical_node_list, node)
 124                 if (device_supports_offline(pn->dev) && !pn->dev->offline) {
 125                         if (uevent)
 126                                 kobject_uevent_env(&pn->dev->kobj, KOBJ_CHANGE, envp);
 127
 128                         offline = false;
 129                         break;
 130                 }
 131
 132         mutex_unlock(&adev->physical_node_lock);
 133         return offline;
 134 }
 135
 136 static acpi_status acpi_bus_offline(acpi_handle handle, u32 lvl, void *data,
 137                                     void **ret_p)
 138 {
 139         struct acpi_device *device = acpi_fetch_acpi_dev(handle);
 140         struct acpi_device_physical_node *pn;
 141         bool second_pass = (bool)data;
 142         acpi_status status = AE_OK;
 143
 144         if (!device)
 145                 return AE_OK;
 146
 147         if (device->handler && !device->handler->hotplug.enabled) {
 148                 *ret_p = &device->dev;
 149                 return AE_SUPPORT;
 150         }
 151
 152         mutex_lock(&device->physical_node_lock);
 153
 154         list_for_each_entry(pn, &device->physical_node_list, node) {
 155                 int ret;
 156
 157                 if (second_pass) {
 158                         /* Skip devices offlined by the first pass. */
 159                         if (pn->put_online)
 160                                 continue;
 161                 } else {
 162                         pn->put_online = false;
 163                 }
 164                 ret = device_offline(pn->dev);
 165                 if (ret >= 0) {
 166                         pn->put_online = !ret;
 167                 } else {
 168                         *ret_p = pn->dev;
 169                         if (second_pass) {
 170                                 status = AE_ERROR;
 171                                 break;
 172                         }
 173                 }
 174         }
 175
 176         mutex_unlock(&device->physical_node_lock);
 177
 178         return status;
 179 }
 180
 181 static acpi_status acpi_bus_online(acpi_handle handle, u32 lvl, void *data,
 182                                    void **ret_p)
 183 {
 184         struct acpi_device *device = acpi_fetch_acpi_dev(handle);
 185         struct acpi_device_physical_node *pn;
 186
 187         if (!device)
 188                 return AE_OK;
 189
 190         mutex_lock(&device->physical_node_lock);
 191
 192         list_for_each_entry(pn, &device->physical_node_list, node)
 193                 if (pn->put_online) {
 194                         device_online(pn->dev);
 195                         pn->put_online = false;
 196                 }
 197
 198         mutex_unlock(&device->physical_node_lock);
 199
 200         return AE_OK;
 201 }
 202
 203 static int acpi_scan_try_to_offline(struct acpi_device *device)
 204 {
 205         acpi_handle handle = device->handle;
 206         struct device *errdev = NULL;
 207         acpi_status status;
 208
 209         /*
 210          * Carry out two passes here and ignore errors in the first pass,
 211          * because if the devices in question are memory blocks and
 212          * CONFIG_MEMCG is set, one of the blocks may hold data structures
 213          * that the other blocks depend on, but it is not known in advance which
 214          * block holds them.
 215          *
 216          * If the first pass is successful, the second one isn't needed, though.
 217          */
 218         status = acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
 219                                      NULL, acpi_bus_offline, (void *)false,
 220                                      (void **)&errdev);
 221         if (status == AE_SUPPORT) {
 222                 dev_warn(errdev, "Offline disabled.\n");
 223                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
 224                                     acpi_bus_online, NULL, NULL, NULL);
 225                 return -EPERM;
 226         }
 227         acpi_bus_offline(handle, 0, (void *)false, (void **)&errdev);
 228         if (errdev) {
 229                 errdev = NULL;
 230                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
 231                                     NULL, acpi_bus_offline, (void *)true,
 232                                     (void **)&errdev);
 233                 if (!errdev)
 234                         acpi_bus_offline(handle, 0, (void *)true,
 235                                          (void **)&errdev);
 236
 237                 if (errdev) {
 238                         dev_warn(errdev, "Offline failed.\n");
 239                         acpi_bus_online(handle, 0, NULL, NULL);
 240                         acpi_walk_namespace(ACPI_TYPE_ANY, handle,
 241                                             ACPI_UINT32_MAX, acpi_bus_online,
 242                                             NULL, NULL, NULL);
 243                         return -EBUSY;
 244                 }
 245         }
 246         return 0;
 247 }
 248
 249 static int acpi_scan_hot_remove(struct acpi_device *device)
 250 {
 251         acpi_handle handle = device->handle;
 252         unsigned long long sta;
 253         acpi_status status;
 254
 255         if (device->handler && device->handler->hotplug.demand_offline) {
 256                 if (!acpi_scan_is_offline(device, true))
 257                         return -EBUSY;
 258         } else {
 259                 int error = acpi_scan_try_to_offline(device);
 260                 if (error)
 261                         return error;
 262         }
 263
 264         acpi_handle_debug(handle, "Ejecting\n");
 265
 266         acpi_bus_trim(device);
 267
 268         acpi_evaluate_lck(handle, 0);
 269         /*
 270          * TBD: _EJD support.
 271          */
 272         status = acpi_evaluate_ej0(handle);
 273         if (status == AE_NOT_FOUND)
 274                 return -ENODEV;
 275         else if (ACPI_FAILURE(status))
 276                 return -EIO;
 277
 278         /*
 279          * Verify if eject was indeed successful.  If not, log an error
 280          * message.  No need to call _OST since _EJ0 call was made OK.
 281          */
 282         status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
 283         if (ACPI_FAILURE(status)) {
 284                 acpi_handle_warn(handle,
 285                         "Status check after eject failed (0x%x)\n", status);
 286         } else if (sta & ACPI_STA_DEVICE_ENABLED) {
 287                 acpi_handle_warn(handle,
 288                         "Eject incomplete - status 0x%llx\n", sta);
 289         }
 290
 291         return 0;
 292 }
 293
 294 static int acpi_scan_device_not_present(struct acpi_device *adev)
 295 {
 296         if (!acpi_device_enumerated(adev)) {
 297                 dev_warn(&adev->dev, "Still not present\n");
 298                 return -EALREADY;
 299         }
 300         acpi_bus_trim(adev);
 301         return 0;
 302 }
 303
 304 static int acpi_scan_device_check(struct acpi_device *adev)
 305 {
 306         int error;
 307
 308         acpi_bus_get_status(adev);
 309         if (adev->status.present || adev->status.functional) {
 310                 /*
 311                  * This function is only called for device objects for which
 312                  * matching scan handlers exist.  The only situation in which
 313                  * the scan handler is not attached to this device object yet
 314                  * is when the device has just appeared (either it wasn't
 315                  * present at all before or it was removed and then added
 316                  * again).
 317                  */
 318                 if (adev->handler) {
 319                         dev_warn(&adev->dev, "Already enumerated\n");
 320                         return -EALREADY;
 321                 }
 322                 error = acpi_bus_scan(adev->handle);
 323                 if (error) {
 324                         dev_warn(&adev->dev, "Namespace scan failure\n");
 325                         return error;
 326                 }
 327                 if (!adev->handler) {
 328                         dev_warn(&adev->dev, "Enumeration failure\n");
 329                         error = -ENODEV;
 330                 }
 331         } else {
 332                 error = acpi_scan_device_not_present(adev);
 333         }
 334         return error;
 335 }
 336
 337 static int acpi_scan_bus_check(struct acpi_device *adev)
 338 {
 339         struct acpi_scan_handler *handler = adev->handler;
 340         struct acpi_device *child;
 341         int error;
 342
 343         acpi_bus_get_status(adev);
 344         if (!(adev->status.present || adev->status.functional)) {
 345                 acpi_scan_device_not_present(adev);
 346                 return 0;
 347         }
 348         if (handler && handler->hotplug.scan_dependent)
 349                 return handler->hotplug.scan_dependent(adev);
 350
 351         error = acpi_bus_scan(adev->handle);
 352         if (error) {
 353                 dev_warn(&adev->dev, "Namespace scan failure\n");
 354                 return error;
 355         }
 356         list_for_each_entry(child, &adev->children, node) {
 357                 error = acpi_scan_bus_check(child);
 358                 if (error)
 359                         return error;
 360         }
 361         return 0;
 362 }
 363
 364 static int acpi_generic_hotplug_event(struct acpi_device *adev, u32 type)
 365 {
 366         switch (type) {
 367         case ACPI_NOTIFY_BUS_CHECK:
 368                 return acpi_scan_bus_check(adev);
 369         case ACPI_NOTIFY_DEVICE_CHECK:
 370                 return acpi_scan_device_check(adev);
 371         case ACPI_NOTIFY_EJECT_REQUEST:
 372         case ACPI_OST_EC_OSPM_EJECT:
 373                 if (adev->handler && !adev->handler->hotplug.enabled) {
 374                         dev_info(&adev->dev, "Eject disabled\n");
 375                         return -EPERM;
 376                 }
 377                 acpi_evaluate_ost(adev->handle, ACPI_NOTIFY_EJECT_REQUEST,
 378                                   ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
 379                 return acpi_scan_hot_remove(adev);
 380         }
 381         return -EINVAL;
 382 }
 383
 384 void acpi_device_hotplug(struct acpi_device *adev, u32 src)
 385 {
 386         u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
 387         int error = -ENODEV;
 388
 389         lock_device_hotplug();
 390         mutex_lock(&acpi_scan_lock);
 391
 392         /*
 393          * The device object's ACPI handle cannot become invalid as long as we
 394          * are holding acpi_scan_lock, but it might have become invalid before
 395          * that lock was acquired.
 396          */
 397         if (adev->handle == INVALID_ACPI_HANDLE)
 398                 goto err_out;
 399
 400         if (adev->flags.is_dock_station) {
 401                 error = dock_notify(adev, src);
 402         } else if (adev->flags.hotplug_notify) {
 403                 error = acpi_generic_hotplug_event(adev, src);
 404         } else {
 405                 int (*notify)(struct acpi_device *, u32);
 406
 407                 acpi_lock_hp_context();
 408                 notify = adev->hp ? adev->hp->notify : NULL;
 409                 acpi_unlock_hp_context();
 410                 /*
 411                  * There may be additional notify handlers for device objects
 412                  * without the .event() callback, so ignore them here.
 413                  */
 414                 if (notify)
 415                         error = notify(adev, src);
 416                 else
 417                         goto out;
 418         }
 419         switch (error) {
 420         case 0:
 421                 ost_code = ACPI_OST_SC_SUCCESS;
 422                 break;
 423         case -EPERM:
 424                 ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
 425                 break;
 426         case -EBUSY:
 427                 ost_code = ACPI_OST_SC_DEVICE_BUSY;
 428                 break;
 429         default:
 430                 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
 431                 break;
 432         }
 433
 434  err_out:
 435         acpi_evaluate_ost(adev->handle, src, ost_code, NULL);
 436
 437  out:
 438         acpi_bus_put_acpi_device(adev);
 439         mutex_unlock(&acpi_scan_lock);
 440         unlock_device_hotplug();
 441 }
 442
 443 static void acpi_free_power_resources_lists(struct acpi_device *device)
 444 {
 445         int i;
 446
 447         if (device->wakeup.flags.valid)
 448                 acpi_power_resources_list_free(&device->wakeup.resources);
 449
 450         if (!device->power.flags.power_resources)
 451                 return;
 452
 453         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
 454                 struct acpi_device_power_state *ps = &device->power.states[i];
 455                 acpi_power_resources_list_free(&ps->resources);
 456         }
 457 }
 458
 459 static void acpi_device_release(struct device *dev)
 460 {
 461         struct acpi_device *acpi_dev = to_acpi_device(dev);
 462
 463         acpi_free_properties(acpi_dev);
 464         acpi_free_pnp_ids(&acpi_dev->pnp);
 465         acpi_free_power_resources_lists(acpi_dev);
 466         kfree(acpi_dev);
 467 }
 468
 469 static void acpi_device_del(struct acpi_device *device)
 470 {
 471         struct acpi_device_bus_id *acpi_device_bus_id;
 472
 473         mutex_lock(&acpi_device_lock);
 474         if (device->parent)
 475                 list_del(&device->node);
 476
 477         list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node)
 478                 if (!strcmp(acpi_device_bus_id->bus_id,
 479                             acpi_device_hid(device))) {
 480                         ida_free(&acpi_device_bus_id->instance_ida,
 481                                  device->pnp.instance_no);
 482                         if (ida_is_empty(&acpi_device_bus_id->instance_ida)) {
 483                                 list_del(&acpi_device_bus_id->node);
 484                                 kfree_const(acpi_device_bus_id->bus_id);
 485                                 kfree(acpi_device_bus_id);
 486                         }
 487                         break;
 488                 }
 489
 490         list_del(&device->wakeup_list);
 491         mutex_unlock(&acpi_device_lock);
 492
 493         acpi_power_add_remove_device(device, false);
 494         acpi_device_remove_files(device);
 495         if (device->remove)
 496                 device->remove(device);
 497
 498         device_del(&device->dev);
 499 }
 500
 501 static BLOCKING_NOTIFIER_HEAD(acpi_reconfig_chain);
 502
 503 static LIST_HEAD(acpi_device_del_list);
 504 static DEFINE_MUTEX(acpi_device_del_lock);
 505
 506 static void acpi_device_del_work_fn(struct work_struct *work_not_used)
 507 {
 508         for (;;) {
 509                 struct acpi_device *adev;
 510
 511                 mutex_lock(&acpi_device_del_lock);
 512
 513                 if (list_empty(&acpi_device_del_list)) {
 514                         mutex_unlock(&acpi_device_del_lock);
 515                         break;
 516                 }
 517                 adev = list_first_entry(&acpi_device_del_list,
 518                                         struct acpi_device, del_list);
 519                 list_del(&adev->del_list);
 520
 521                 mutex_unlock(&acpi_device_del_lock);
 522
 523                 blocking_notifier_call_chain(&acpi_reconfig_chain,
 524                                              ACPI_RECONFIG_DEVICE_REMOVE, adev);
 525
 526                 acpi_device_del(adev);
 527                 /*
 528                  * Drop references to all power resources that might have been
 529                  * used by the device.
 530                  */
 531                 acpi_power_transition(adev, ACPI_STATE_D3_COLD);
 532                 acpi_dev_put(adev);
 533         }
 534 }
 535
 536 /**
 537  * acpi_scan_drop_device - Drop an ACPI device object.
 538  * @handle: Handle of an ACPI namespace node, not used.
 539  * @context: Address of the ACPI device object to drop.
 540  *
 541  * This is invoked by acpi_ns_delete_node() during the removal of the ACPI
 542  * namespace node the device object pointed to by @context is attached to.
 543  *
 544  * The unregistration is carried out asynchronously to avoid running
 545  * acpi_device_del() under the ACPICA's namespace mutex and the list is used to
 546  * ensure the correct ordering (the device objects must be unregistered in the
 547  * same order in which the corresponding namespace nodes are deleted).
 548  */
 549 static void acpi_scan_drop_device(acpi_handle handle, void *context)
 550 {
 551         static DECLARE_WORK(work, acpi_device_del_work_fn);
 552         struct acpi_device *adev = context;
 553
 554         mutex_lock(&acpi_device_del_lock);
 555
 556         /*
 557          * Use the ACPI hotplug workqueue which is ordered, so this work item
 558          * won't run after any hotplug work items submitted subsequently.  That
 559          * prevents attempts to register device objects identical to those being
 560          * deleted from happening concurrently (such attempts result from
 561          * hotplug events handled via the ACPI hotplug workqueue).  It also will
 562          * run after all of the work items submitted previously, which helps
 563          * those work items to ensure that they are not accessing stale device
 564          * objects.
 565          */
 566         if (list_empty(&acpi_device_del_list))
 567                 acpi_queue_hotplug_work(&work);
 568
 569         list_add_tail(&adev->del_list, &acpi_device_del_list);
 570         /* Make acpi_ns_validate_handle() return NULL for this handle. */
 571         adev->handle = INVALID_ACPI_HANDLE;
 572
 573         mutex_unlock(&acpi_device_del_lock);
 574 }
 575
 576 static struct acpi_device *handle_to_device(acpi_handle handle,
 577                                             void (*callback)(void *))
 578 {
 579         struct acpi_device *adev = NULL;
 580         acpi_status status;
 581
 582         status = acpi_get_data_full(handle, acpi_scan_drop_device,
 583                                     (void **)&adev, callback);
 584         if (ACPI_FAILURE(status) || !adev) {
 585                 acpi_handle_debug(handle, "No context!\n");
 586                 return NULL;
 587         }
 588         return adev;
 589 }
 590
 591 int acpi_bus_get_device(acpi_handle handle, struct acpi_device **device)
 592 {
 593         if (!device)
 594                 return -EINVAL;
 595
 596         *device = handle_to_device(handle, NULL);
 597         if (!*device)
 598                 return -ENODEV;
 599
 600         return 0;
 601 }
 602 EXPORT_SYMBOL(acpi_bus_get_device);
 603
 604 /**
 605  * acpi_fetch_acpi_dev - Retrieve ACPI device object.
 606  * @handle: ACPI handle associated with the requested ACPI device object.
 607  *
 608  * Return a pointer to the ACPI device object associated with @handle, if
 609  * present, or NULL otherwise.
 610  */
 611 struct acpi_device *acpi_fetch_acpi_dev(acpi_handle handle)
 612 {
 613         return handle_to_device(handle, NULL);
 614 }
 615 EXPORT_SYMBOL_GPL(acpi_fetch_acpi_dev);
 616
 617 static void get_acpi_device(void *dev)
 618 {
 619         acpi_dev_get(dev);
 620 }
 621
 622 struct acpi_device *acpi_bus_get_acpi_device(acpi_handle handle)
 623 {
 624         return handle_to_device(handle, get_acpi_device);
 625 }
 626 EXPORT_SYMBOL_GPL(acpi_bus_get_acpi_device);
 627
 628 static struct acpi_device_bus_id *acpi_device_bus_id_match(const char *dev_id)
 629 {
 630         struct acpi_device_bus_id *acpi_device_bus_id;
 631
 632         /* Find suitable bus_id and instance number in acpi_bus_id_list. */
 633         list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
 634                 if (!strcmp(acpi_device_bus_id->bus_id, dev_id))
 635                         return acpi_device_bus_id;
 636         }
 637         return NULL;
 638 }
 639
 640 static int acpi_device_set_name(struct acpi_device *device,
 641                                 struct acpi_device_bus_id *acpi_device_bus_id)
 642 {
 643         struct ida *instance_ida = &acpi_device_bus_id->instance_ida;
 644         int result;
 645
 646         result = ida_alloc(instance_ida, GFP_KERNEL);
 647         if (result < 0)
 648                 return result;
 649
 650         device->pnp.instance_no = result;
 651         dev_set_name(&device->dev, "%s:%02x", acpi_device_bus_id->bus_id, result);
 652         return 0;
 653 }
 654
 655 static int acpi_tie_acpi_dev(struct acpi_device *adev)
 656 {
 657         acpi_handle handle = adev->handle;
 658         acpi_status status;
 659
 660         if (!handle)
 661                 return 0;
 662
 663         status = acpi_attach_data(handle, acpi_scan_drop_device, adev);
 664         if (ACPI_FAILURE(status)) {
 665                 acpi_handle_err(handle, "Unable to attach device data\n");
 666                 return -ENODEV;
 667         }
 668
 669         return 0;
 670 }
 671
 672 static void acpi_store_pld_crc(struct acpi_device *adev)
 673 {
 674         struct acpi_pld_info *pld;
 675         acpi_status status;
 676
 677         status = acpi_get_physical_device_location(adev->handle, &pld);
 678         if (ACPI_FAILURE(status))
 679                 return;
 680
 681         adev->pld_crc = crc32(~0, pld, sizeof(*pld));
 682         ACPI_FREE(pld);
 683 }
 684
 685 static int __acpi_device_add(struct acpi_device *device,
 686                              void (*release)(struct device *))
 687 {
 688         struct acpi_device_bus_id *acpi_device_bus_id;
 689         int result;
 690
 691         /*
 692          * Linkage
 693          * -------
 694          * Link this device to its parent and siblings.
 695          */
 696         INIT_LIST_HEAD(&device->children);
 697         INIT_LIST_HEAD(&device->node);
 698         INIT_LIST_HEAD(&device->wakeup_list);
 699         INIT_LIST_HEAD(&device->physical_node_list);
 700         INIT_LIST_HEAD(&device->del_list);
 701         mutex_init(&device->physical_node_lock);
 702
 703         mutex_lock(&acpi_device_lock);
 704
 705         acpi_device_bus_id = acpi_device_bus_id_match(acpi_device_hid(device));
 706         if (acpi_device_bus_id) {
 707                 result = acpi_device_set_name(device, acpi_device_bus_id);
 708                 if (result)
 709                         goto err_unlock;
 710         } else {
 711                 acpi_device_bus_id = kzalloc(sizeof(*acpi_device_bus_id),
 712                                              GFP_KERNEL);
 713                 if (!acpi_device_bus_id) {
 714                         result = -ENOMEM;
 715                         goto err_unlock;
 716                 }
 717                 acpi_device_bus_id->bus_id =
 718                         kstrdup_const(acpi_device_hid(device), GFP_KERNEL);
 719                 if (!acpi_device_bus_id->bus_id) {
 720                         kfree(acpi_device_bus_id);
 721                         result = -ENOMEM;
 722                         goto err_unlock;
 723                 }
 724
 725                 ida_init(&acpi_device_bus_id->instance_ida);
 726
 727                 result = acpi_device_set_name(device, acpi_device_bus_id);
 728                 if (result) {
 729                         kfree_const(acpi_device_bus_id->bus_id);
 730                         kfree(acpi_device_bus_id);
 731                         goto err_unlock;
 732                 }
 733
 734                 list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
 735         }
 736
 737         if (device->parent)
 738                 list_add_tail(&device->node, &device->parent->children);
 739
 740         if (device->wakeup.flags.valid)
 741                 list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);
 742
 743         acpi_store_pld_crc(device);
 744
 745         mutex_unlock(&acpi_device_lock);
 746
 747         if (device->parent)
 748                 device->dev.parent = &device->parent->dev;
 749
 750         device->dev.bus = &acpi_bus_type;
 751         device->dev.release = release;
 752         result = device_add(&device->dev);
 753         if (result) {
 754                 dev_err(&device->dev, "Error registering device\n");
 755                 goto err;
 756         }
 757
 758         result = acpi_device_setup_files(device);
 759         if (result)
 760                 pr_err("Error creating sysfs interface for device %s\n",
 761                        dev_name(&device->dev));
 762
 763         return 0;
 764
 765 err:
 766         mutex_lock(&acpi_device_lock);
 767
 768         if (device->parent)
 769                 list_del(&device->node);
 770
 771         list_del(&device->wakeup_list);
 772
 773 err_unlock:
 774         mutex_unlock(&acpi_device_lock);
 775
 776         acpi_detach_data(device->handle, acpi_scan_drop_device);
 777
 778         return result;
 779 }
 780
 781 int acpi_device_add(struct acpi_device *adev, void (*release)(struct device *))
 782 {
 783         int ret;
 784
 785         ret = acpi_tie_acpi_dev(adev);
 786         if (ret)
 787                 return ret;
 788
 789         return __acpi_device_add(adev, release);
 790 }
 791
 792 /* --------------------------------------------------------------------------
 793                                  Device Enumeration
 794    -------------------------------------------------------------------------- */
 795 static bool acpi_info_matches_ids(struct acpi_device_info *info,
 796                                   const char * const ids[])
 797 {
 798         struct acpi_pnp_device_id_list *cid_list = NULL;
 799         int i, index;
 800
 801         if (!(info->valid & ACPI_VALID_HID))
 802                 return false;
 803
 804         index = match_string(ids, -1, info->hardware_id.string);
 805         if (index >= 0)
 806                 return true;
 807
 808         if (info->valid & ACPI_VALID_CID)
 809                 cid_list = &info->compatible_id_list;
 810
 811         if (!cid_list)
 812                 return false;
 813
 814         for (i = 0; i < cid_list->count; i++) {
 815                 index = match_string(ids, -1, cid_list->ids[i].string);
 816                 if (index >= 0)
 817                         return true;
 818         }
 819
 820         return false;
 821 }
 822
 823 /* List of HIDs for which we ignore matching ACPI devices, when checking _DEP lists. */
 824 static const char * const acpi_ignore_dep_ids[] = {
 825         "PNP0D80", /* Windows-compatible System Power Management Controller */
 826         "INT33BD", /* Intel Baytrail Mailbox Device */
 827         NULL
 828 };
 829
 830 /* List of HIDs for which we honor deps of matching ACPI devs, when checking _DEP lists. */
 831 static const char * const acpi_honor_dep_ids[] = {
 832         "INT3472", /* Camera sensor PMIC / clk and regulator info */
 833         NULL
 834 };
 835
 836 static struct acpi_device *acpi_bus_get_parent(acpi_handle handle)
 837 {
 838         struct acpi_device *device;
 839         acpi_status status;
 840
 841         /*
 842          * Fixed hardware devices do not appear in the namespace and do not
 843          * have handles, but we fabricate acpi_devices for them, so we have
 844          * to deal with them specially.
 845          */
 846         if (!handle)
 847                 return acpi_root;
 848
 849         do {
 850                 status = acpi_get_parent(handle, &handle);
 851                 if (ACPI_FAILURE(status))
 852                         return status == AE_NULL_ENTRY ? NULL : acpi_root;
 853
 854                 device = acpi_fetch_acpi_dev(handle);
 855         } while (!device);
 856         return device;
 857 }
 858
 859 acpi_status
 860 acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
 861 {
 862         acpi_status status;
 863         acpi_handle tmp;
 864         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
 865         union acpi_object *obj;
 866
 867         status = acpi_get_handle(handle, "_EJD", &tmp);
 868         if (ACPI_FAILURE(status))
 869                 return status;
 870
 871         status = acpi_evaluate_object(handle, "_EJD", NULL, &buffer);
 872         if (ACPI_SUCCESS(status)) {
 873                 obj = buffer.pointer;
 874                 status = acpi_get_handle(ACPI_ROOT_OBJECT, obj->string.pointer,
 875                                          ejd);
 876                 kfree(buffer.pointer);
 877         }
 878         return status;
 879 }
 880 EXPORT_SYMBOL_GPL(acpi_bus_get_ejd);
 881
 882 static int acpi_bus_extract_wakeup_device_power_package(struct acpi_device *dev)
 883 {
 884         acpi_handle handle = dev->handle;
 885         struct acpi_device_wakeup *wakeup = &dev->wakeup;
 886         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 887         union acpi_object *package = NULL;
 888         union acpi_object *element = NULL;
 889         acpi_status status;
 890         int err = -ENODATA;
 891
 892         INIT_LIST_HEAD(&wakeup->resources);
 893
 894         /* _PRW */
 895         status = acpi_evaluate_object(handle, "_PRW", NULL, &buffer);
 896         if (ACPI_FAILURE(status)) {
 897                 acpi_handle_info(handle, "_PRW evaluation failed: %s\n",
 898                                  acpi_format_exception(status));
 899                 return err;
 900         }
 901
 902         package = (union acpi_object *)buffer.pointer;
 903
 904         if (!package || package->package.count < 2)
 905                 goto out;
 906
 907         element = &(package->package.elements[0]);
 908         if (!element)
 909                 goto out;
 910
 911         if (element->type == ACPI_TYPE_PACKAGE) {
 912                 if ((element->package.count < 2) ||
 913                     (element->package.elements[0].type !=
 914                      ACPI_TYPE_LOCAL_REFERENCE)
 915                     || (element->package.elements[1].type != ACPI_TYPE_INTEGER))
 916                         goto out;
 917
 918                 wakeup->gpe_device =
 919                     element->package.elements[0].reference.handle;
 920                 wakeup->gpe_number =
 921                     (u32) element->package.elements[1].integer.value;
 922         } else if (element->type == ACPI_TYPE_INTEGER) {
 923                 wakeup->gpe_device = NULL;
 924                 wakeup->gpe_number = element->integer.value;
 925         } else {
 926                 goto out;
 927         }
 928
 929         element = &(package->package.elements[1]);
 930         if (element->type != ACPI_TYPE_INTEGER)
 931                 goto out;
 932
 933         wakeup->sleep_state = element->integer.value;
 934
 935         err = acpi_extract_power_resources(package, 2, &wakeup->resources);
 936         if (err)
 937                 goto out;
 938
 939         if (!list_empty(&wakeup->resources)) {
 940                 int sleep_state;
 941
 942                 err = acpi_power_wakeup_list_init(&wakeup->resources,
 943                                                   &sleep_state);
 944                 if (err) {
 945                         acpi_handle_warn(handle, "Retrieving current states "
 946                                          "of wakeup power resources failed\n");
 947                         acpi_power_resources_list_free(&wakeup->resources);
 948                         goto out;
 949                 }
 950                 if (sleep_state < wakeup->sleep_state) {
 951                         acpi_handle_warn(handle, "Overriding _PRW sleep state "
 952                                          "(S%d) by S%d from power resources\n",
 953                                          (int)wakeup->sleep_state, sleep_state);
 954                         wakeup->sleep_state = sleep_state;
 955                 }
 956         }
 957
 958  out:
 959         kfree(buffer.pointer);
 960         return err;
 961 }
 962
 963 static bool acpi_wakeup_gpe_init(struct acpi_device *device)
 964 {
 965         static const struct acpi_device_id button_device_ids[] = {
 966                 {"PNP0C0C", 0},         /* Power button */
 967                 {"PNP0C0D", 0},         /* Lid */
 968                 {"PNP0C0E", 0},         /* Sleep button */
 969                 {"", 0},
 970         };
 971         struct acpi_device_wakeup *wakeup = &device->wakeup;
 972         acpi_status status;
 973
 974         wakeup->flags.notifier_present = 0;
 975
 976         /* Power button, Lid switch always enable wakeup */
 977         if (!acpi_match_device_ids(device, button_device_ids)) {
 978                 if (!acpi_match_device_ids(device, &button_device_ids[1])) {
 979                         /* Do not use Lid/sleep button for S5 wakeup */
 980                         if (wakeup->sleep_state == ACPI_STATE_S5)
 981                                 wakeup->sleep_state = ACPI_STATE_S4;
 982                 }
 983                 acpi_mark_gpe_for_wake(wakeup->gpe_device, wakeup->gpe_number);
 984                 device_set_wakeup_capable(&device->dev, true);
 985                 return true;
 986         }
 987
 988         status = acpi_setup_gpe_for_wake(device->handle, wakeup->gpe_device,
 989                                          wakeup->gpe_number);
 990         return ACPI_SUCCESS(status);
 991 }
 992
 993 static void acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
 994 {
 995         int err;
 996
 997         /* Presence of _PRW indicates wake capable */
 998         if (!acpi_has_method(device->handle, "_PRW"))
 999                 return;
1000
1001         err = acpi_bus_extract_wakeup_device_power_package(device);
1002         if (err) {
1003                 dev_err(&device->dev, "Unable to extract wakeup power resources");
1004                 return;
1005         }
1006
1007         device->wakeup.flags.valid = acpi_wakeup_gpe_init(device);
1008         device->wakeup.prepare_count = 0;
1009         /*
1010          * Call _PSW/_DSW object to disable its ability to wake the sleeping
1011          * system for the ACPI device with the _PRW object.
1012          * The _PSW object is deprecated in ACPI 3.0 and is replaced by _DSW.
1013          * So it is necessary to call _DSW object first. Only when it is not
1014          * present will the _PSW object used.
1015          */
1016         err = acpi_device_sleep_wake(device, 0, 0, 0);
1017         if (err)
1018                 pr_debug("error in _DSW or _PSW evaluation\n");
1019 }
1020
1021 static void acpi_bus_init_power_state(struct acpi_device *device, int state)
1022 {
1023         struct acpi_device_power_state *ps = &device->power.states[state];
1024         char pathname[5] = { '_', 'P', 'R', '0' + state, '\0' };
1025         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1026         acpi_status status;
1027
1028         INIT_LIST_HEAD(&ps->resources);
1029
1030         /* Evaluate "_PRx" to get referenced power resources */
1031         status = acpi_evaluate_object(device->handle, pathname, NULL, &buffer);
1032         if (ACPI_SUCCESS(status)) {
1033                 union acpi_object *package = buffer.pointer;
1034
1035                 if (buffer.length && package
1036                     && package->type == ACPI_TYPE_PACKAGE
1037                     && package->package.count)
1038                         acpi_extract_power_resources(package, 0, &ps->resources);
1039
1040                 ACPI_FREE(buffer.pointer);
1041         }
1042
1043         /* Evaluate "_PSx" to see if we can do explicit sets */
1044         pathname[2] = 'S';
1045         if (acpi_has_method(device->handle, pathname))
1046                 ps->flags.explicit_set = 1;
1047
1048         /* State is valid if there are means to put the device into it. */
1049         if (!list_empty(&ps->resources) || ps->flags.explicit_set)
1050                 ps->flags.valid = 1;
1051
1052         ps->power = -1;         /* Unknown - driver assigned */
1053         ps->latency = -1;       /* Unknown - driver assigned */
1054 }
1055
1056 static void acpi_bus_get_power_flags(struct acpi_device *device)
1057 {
1058         unsigned long long dsc = ACPI_STATE_D0;
1059         u32 i;
1060
1061         /* Presence of _PS0|_PR0 indicates 'power manageable' */
1062         if (!acpi_has_method(device->handle, "_PS0") &&
1063             !acpi_has_method(device->handle, "_PR0"))
1064                 return;
1065
1066         device->flags.power_manageable = 1;
1067
1068         /*
1069          * Power Management Flags
1070          */
1071         if (acpi_has_method(device->handle, "_PSC"))
1072                 device->power.flags.explicit_get = 1;
1073
1074         if (acpi_has_method(device->handle, "_IRC"))
1075                 device->power.flags.inrush_current = 1;
1076
1077         if (acpi_has_method(device->handle, "_DSW"))
1078                 device->power.flags.dsw_present = 1;
1079
1080         acpi_evaluate_integer(device->handle, "_DSC", NULL, &dsc);
1081         device->power.state_for_enumeration = dsc;
1082
1083         /*
1084          * Enumerate supported power management states
1085          */
1086         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++)
1087                 acpi_bus_init_power_state(device, i);
1088
1089         INIT_LIST_HEAD(&device->power.states[ACPI_STATE_D3_COLD].resources);
1090
1091         /* Set the defaults for D0 and D3hot (always supported). */
1092         device->power.states[ACPI_STATE_D0].flags.valid = 1;
1093         device->power.states[ACPI_STATE_D0].power = 100;
1094         device->power.states[ACPI_STATE_D3_HOT].flags.valid = 1;
1095
1096         /*
1097          * Use power resources only if the D0 list of them is populated, because
1098          * some platforms may provide _PR3 only to indicate D3cold support and
1099          * in those cases the power resources list returned by it may be bogus.
1100          */
1101         if (!list_empty(&device->power.states[ACPI_STATE_D0].resources)) {
1102                 device->power.flags.power_resources = 1;
1103                 /*
1104                  * D3cold is supported if the D3hot list of power resources is
1105                  * not empty.
1106                  */
1107                 if (!list_empty(&device->power.states[ACPI_STATE_D3_HOT].resources))
1108                         device->power.states[ACPI_STATE_D3_COLD].flags.valid = 1;
1109         }
1110
1111         if (acpi_bus_init_power(device))
1112                 device->flags.power_manageable = 0;
1113 }
1114
1115 static void acpi_bus_get_flags(struct acpi_device *device)
1116 {
1117         /* Presence of _STA indicates 'dynamic_status' */
1118         if (acpi_has_method(device->handle, "_STA"))
1119                 device->flags.dynamic_status = 1;
1120
1121         /* Presence of _RMV indicates 'removable' */
1122         if (acpi_has_method(device->handle, "_RMV"))
1123                 device->flags.removable = 1;
1124
1125         /* Presence of _EJD|_EJ0 indicates 'ejectable' */
1126         if (acpi_has_method(device->handle, "_EJD") ||
1127             acpi_has_method(device->handle, "_EJ0"))
1128                 device->flags.ejectable = 1;
1129 }
1130
1131 static void acpi_device_get_busid(struct acpi_device *device)
1132 {
1133         char bus_id[5] = { '?', 0 };
1134         struct acpi_buffer buffer = { sizeof(bus_id), bus_id };
1135         int i = 0;
1136
1137         /*
1138          * Bus ID
1139          * ------
1140          * The device's Bus ID is simply the object name.
1141          * TBD: Shouldn't this value be unique (within the ACPI namespace)?
1142          */
1143         if (ACPI_IS_ROOT_DEVICE(device)) {
1144                 strcpy(device->pnp.bus_id, "ACPI");
1145                 return;
1146         }
1147
1148         switch (device->device_type) {
1149         case ACPI_BUS_TYPE_POWER_BUTTON:
1150                 strcpy(device->pnp.bus_id, "PWRF");
1151                 break;
1152         case ACPI_BUS_TYPE_SLEEP_BUTTON:
1153                 strcpy(device->pnp.bus_id, "SLPF");
1154                 break;
1155         case ACPI_BUS_TYPE_ECDT_EC:
1156                 strcpy(device->pnp.bus_id, "ECDT");
1157                 break;
1158         default:
1159                 acpi_get_name(device->handle, ACPI_SINGLE_NAME, &buffer);
1160                 /* Clean up trailing underscores (if any) */
1161                 for (i = 3; i > 1; i--) {
1162                         if (bus_id[i] == '_')
1163                                 bus_id[i] = '\0';
1164                         else
1165                                 break;
1166                 }
1167                 strcpy(device->pnp.bus_id, bus_id);
1168                 break;
1169         }
1170 }
1171
1172 /*
1173  * acpi_ata_match - see if an acpi object is an ATA device
1174  *
1175  * If an acpi object has one of the ACPI ATA methods defined,
1176  * then we can safely call it an ATA device.
1177  */
1178 bool acpi_ata_match(acpi_handle handle)
1179 {
1180         return acpi_has_method(handle, "_GTF") ||
1181                acpi_has_method(handle, "_GTM") ||
1182                acpi_has_method(handle, "_STM") ||
1183                acpi_has_method(handle, "_SDD");
1184 }
1185
1186 /*
1187  * acpi_bay_match - see if an acpi object is an ejectable driver bay
1188  *
1189  * If an acpi object is ejectable and has one of the ACPI ATA methods defined,
1190  * then we can safely call it an ejectable drive bay
1191  */
1192 bool acpi_bay_match(acpi_handle handle)
1193 {
1194         acpi_handle phandle;
1195
1196         if (!acpi_has_method(handle, "_EJ0"))
1197                 return false;
1198         if (acpi_ata_match(handle))
1199                 return true;
1200         if (ACPI_FAILURE(acpi_get_parent(handle, &phandle)))
1201                 return false;
1202
1203         return acpi_ata_match(phandle);
1204 }
1205
1206 bool acpi_device_is_battery(struct acpi_device *adev)
1207 {
1208         struct acpi_hardware_id *hwid;
1209
1210         list_for_each_entry(hwid, &adev->pnp.ids, list)
1211                 if (!strcmp("PNP0C0A", hwid->id))
1212                         return true;
1213
1214         return false;
1215 }
1216
1217 static bool is_ejectable_bay(struct acpi_device *adev)
1218 {
1219         acpi_handle handle = adev->handle;
1220
1221         if (acpi_has_method(handle, "_EJ0") && acpi_device_is_battery(adev))
1222                 return true;
1223
1224         return acpi_bay_match(handle);
1225 }
1226
1227 /*
1228  * acpi_dock_match - see if an acpi object has a _DCK method
1229  */
1230 bool acpi_dock_match(acpi_handle handle)
1231 {
1232         return acpi_has_method(handle, "_DCK");
1233 }
1234
1235 static acpi_status
1236 acpi_backlight_cap_match(acpi_handle handle, u32 level, void *context,
1237                           void **return_value)
1238 {
1239         long *cap = context;
1240
1241         if (acpi_has_method(handle, "_BCM") &&
1242             acpi_has_method(handle, "_BCL")) {
1243                 acpi_handle_debug(handle, "Found generic backlight support\n");
1244                 *cap |= ACPI_VIDEO_BACKLIGHT;
1245                 /* We have backlight support, no need to scan further */
1246                 return AE_CTRL_TERMINATE;
1247         }
1248         return 0;
1249 }
1250
1251 /* Returns true if the ACPI object is a video device which can be
1252  * handled by video.ko.
1253  * The device will get a Linux specific CID added in scan.c to
1254  * identify the device as an ACPI graphics device
1255  * Be aware that the graphics device may not be physically present
1256  * Use acpi_video_get_capabilities() to detect general ACPI video
1257  * capabilities of present cards
1258  */
1259 long acpi_is_video_device(acpi_handle handle)
1260 {
1261         long video_caps = 0;
1262
1263         /* Is this device able to support video switching ? */
1264         if (acpi_has_method(handle, "_DOD") || acpi_has_method(handle, "_DOS"))
1265                 video_caps |= ACPI_VIDEO_OUTPUT_SWITCHING;
1266
1267         /* Is this device able to retrieve a video ROM ? */
1268         if (acpi_has_method(handle, "_ROM"))
1269                 video_caps |= ACPI_VIDEO_ROM_AVAILABLE;
1270
1271         /* Is this device able to configure which video head to be POSTed ? */
1272         if (acpi_has_method(handle, "_VPO") &&
1273             acpi_has_method(handle, "_GPD") &&
1274             acpi_has_method(handle, "_SPD"))
1275                 video_caps |= ACPI_VIDEO_DEVICE_POSTING;
1276
1277         /* Only check for backlight functionality if one of the above hit. */
1278         if (video_caps)
1279                 acpi_walk_namespace(ACPI_TYPE_DEVICE, handle,
1280                                     ACPI_UINT32_MAX, acpi_backlight_cap_match, NULL,
1281                                     &video_caps, NULL);
1282
1283         return video_caps;
1284 }
1285 EXPORT_SYMBOL(acpi_is_video_device);
1286
1287 const char *acpi_device_hid(struct acpi_device *device)
1288 {
1289         struct acpi_hardware_id *hid;
1290
1291         if (list_empty(&device->pnp.ids))
1292                 return dummy_hid;
1293
1294         hid = list_first_entry(&device->pnp.ids, struct acpi_hardware_id, list);
1295         return hid->id;
1296 }
1297 EXPORT_SYMBOL(acpi_device_hid);
1298
1299 static void acpi_add_id(struct acpi_device_pnp *pnp, const char *dev_id)
1300 {
1301         struct acpi_hardware_id *id;
1302
1303         id = kmalloc(sizeof(*id), GFP_KERNEL);
1304         if (!id)
1305                 return;
1306
1307         id->id = kstrdup_const(dev_id, GFP_KERNEL);
1308         if (!id->id) {
1309                 kfree(id);
1310                 return;
1311         }
1312
1313         list_add_tail(&id->list, &pnp->ids);
1314         pnp->type.hardware_id = 1;
1315 }
1316
1317 /*
1318  * Old IBM workstations have a DSDT bug wherein the SMBus object
1319  * lacks the SMBUS01 HID and the methods do not have the necessary "_"
1320  * prefix.  Work around this.
1321  */
1322 static bool acpi_ibm_smbus_match(acpi_handle handle)
1323 {
1324         char node_name[ACPI_PATH_SEGMENT_LENGTH];
1325         struct acpi_buffer path = { sizeof(node_name), node_name };
1326
1327         if (!dmi_name_in_vendors("IBM"))
1328                 return false;
1329
1330         /* Look for SMBS object */
1331         if (ACPI_FAILURE(acpi_get_name(handle, ACPI_SINGLE_NAME, &path)) ||
1332             strcmp("SMBS", path.pointer))
1333                 return false;
1334
1335         /* Does it have the necessary (but misnamed) methods? */
1336         if (acpi_has_method(handle, "SBI") &&
1337             acpi_has_method(handle, "SBR") &&
1338             acpi_has_method(handle, "SBW"))
1339                 return true;
1340
1341         return false;
1342 }
1343
1344 static bool acpi_object_is_system_bus(acpi_handle handle)
1345 {
1346         acpi_handle tmp;
1347
1348         if (ACPI_SUCCESS(acpi_get_handle(NULL, "\\_SB", &tmp)) &&
1349             tmp == handle)
1350                 return true;
1351         if (ACPI_SUCCESS(acpi_get_handle(NULL, "\\_TZ", &tmp)) &&
1352             tmp == handle)
1353                 return true;
1354
1355         return false;
1356 }
1357
1358 static void acpi_set_pnp_ids(acpi_handle handle, struct acpi_device_pnp *pnp,
1359                              int device_type)
1360 {
1361         struct acpi_device_info *info = NULL;
1362         struct acpi_pnp_device_id_list *cid_list;
1363         int i;
1364
1365         switch (device_type) {
1366         case ACPI_BUS_TYPE_DEVICE:
1367                 if (handle == ACPI_ROOT_OBJECT) {
1368                         acpi_add_id(pnp, ACPI_SYSTEM_HID);
1369                         break;
1370                 }
1371
1372                 acpi_get_object_info(handle, &info);
1373                 if (!info) {
1374                         pr_err("%s: Error reading device info\n", __func__);
1375                         return;
1376                 }
1377
1378                 if (info->valid & ACPI_VALID_HID) {
1379                         acpi_add_id(pnp, info->hardware_id.string);
1380                         pnp->type.platform_id = 1;
1381                 }
1382                 if (info->valid & ACPI_VALID_CID) {
1383                         cid_list = &info->compatible_id_list;
1384                         for (i = 0; i < cid_list->count; i++)
1385                                 acpi_add_id(pnp, cid_list->ids[i].string);
1386                 }
1387                 if (info->valid & ACPI_VALID_ADR) {
1388                         pnp->bus_address = info->address;
1389                         pnp->type.bus_address = 1;
1390                 }
1391                 if (info->valid & ACPI_VALID_UID)
1392                         pnp->unique_id = kstrdup(info->unique_id.string,
1393                                                         GFP_KERNEL);
1394                 if (info->valid & ACPI_VALID_CLS)
1395                         acpi_add_id(pnp, info->class_code.string);
1396
1397                 kfree(info);
1398
1399                 /*
1400                  * Some devices don't reliably have _HIDs & _CIDs, so add
1401                  * synthetic HIDs to make sure drivers can find them.
1402                  */
1403                 if (acpi_is_video_device(handle))
1404                         acpi_add_id(pnp, ACPI_VIDEO_HID);
1405                 else if (acpi_bay_match(handle))
1406                         acpi_add_id(pnp, ACPI_BAY_HID);
1407                 else if (acpi_dock_match(handle))
1408                         acpi_add_id(pnp, ACPI_DOCK_HID);
1409                 else if (acpi_ibm_smbus_match(handle))
1410                         acpi_add_id(pnp, ACPI_SMBUS_IBM_HID);
1411                 else if (list_empty(&pnp->ids) &&
1412                          acpi_object_is_system_bus(handle)) {
1413                         /* \_SB, \_TZ, LNXSYBUS */
1414                         acpi_add_id(pnp, ACPI_BUS_HID);
1415                         strcpy(pnp->device_name, ACPI_BUS_DEVICE_NAME);
1416                         strcpy(pnp->device_class, ACPI_BUS_CLASS);
1417                 }
1418
1419                 break;
1420         case ACPI_BUS_TYPE_POWER:
1421                 acpi_add_id(pnp, ACPI_POWER_HID);
1422                 break;
1423         case ACPI_BUS_TYPE_PROCESSOR:
1424                 acpi_add_id(pnp, ACPI_PROCESSOR_OBJECT_HID);
1425                 break;
1426         case ACPI_BUS_TYPE_THERMAL:
1427                 acpi_add_id(pnp, ACPI_THERMAL_HID);
1428                 break;
1429         case ACPI_BUS_TYPE_POWER_BUTTON:
1430                 acpi_add_id(pnp, ACPI_BUTTON_HID_POWERF);
1431                 break;
1432         case ACPI_BUS_TYPE_SLEEP_BUTTON:
1433                 acpi_add_id(pnp, ACPI_BUTTON_HID_SLEEPF);
1434                 break;
1435         case ACPI_BUS_TYPE_ECDT_EC:
1436                 acpi_add_id(pnp, ACPI_ECDT_HID);
1437                 break;
1438         }
1439 }
1440
1441 void acpi_free_pnp_ids(struct acpi_device_pnp *pnp)
1442 {
1443         struct acpi_hardware_id *id, *tmp;
1444
1445         list_for_each_entry_safe(id, tmp, &pnp->ids, list) {
1446                 kfree_const(id->id);
1447                 kfree(id);
1448         }
1449         kfree(pnp->unique_id);
1450 }
1451
1452 /**
1453  * acpi_dma_supported - Check DMA support for the specified device.
1454  * @adev: The pointer to acpi device
1455  *
1456  * Return false if DMA is not supported. Otherwise, return true
1457  */
1458 bool acpi_dma_supported(const struct acpi_device *adev)
1459 {
1460         if (!adev)
1461                 return false;
1462
1463         if (adev->flags.cca_seen)
1464                 return true;
1465
1466         /*
1467         * Per ACPI 6.0 sec 6.2.17, assume devices can do cache-coherent
1468         * DMA on "Intel platforms".  Presumably that includes all x86 and
1469         * ia64, and other arches will set CONFIG_ACPI_CCA_REQUIRED=y.
1470         */
1471         if (!IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED))
1472                 return true;
1473
1474         return false;
1475 }
1476
1477 /**
1478  * acpi_get_dma_attr - Check the supported DMA attr for the specified device.
1479  * @adev: The pointer to acpi device
1480  *
1481  * Return enum dev_dma_attr.
1482  */
1483 enum dev_dma_attr acpi_get_dma_attr(struct acpi_device *adev)
1484 {
1485         if (!acpi_dma_supported(adev))
1486                 return DEV_DMA_NOT_SUPPORTED;
1487
1488         if (adev->flags.coherent_dma)
1489                 return DEV_DMA_COHERENT;
1490         else
1491                 return DEV_DMA_NON_COHERENT;
1492 }
1493
1494 /**
1495  * acpi_dma_get_range() - Get device DMA parameters.
1496  *
1497  * @dev: device to configure
1498  * @dma_addr: pointer device DMA address result
1499  * @offset: pointer to the DMA offset result
1500  * @size: pointer to DMA range size result
1501  *
1502  * Evaluate DMA regions and return respectively DMA region start, offset
1503  * and size in dma_addr, offset and size on parsing success; it does not
1504  * update the passed in values on failure.
1505  *
1506  * Return 0 on success, < 0 on failure.
1507  */
1508 int acpi_dma_get_range(struct device *dev, u64 *dma_addr, u64 *offset,
1509                        u64 *size)
1510 {
1511         struct acpi_device *adev;
1512         LIST_HEAD(list);
1513         struct resource_entry *rentry;
1514         int ret;
1515         struct device *dma_dev = dev;
1516         u64 len, dma_start = U64_MAX, dma_end = 0, dma_offset = 0;
1517
1518         /*
1519          * Walk the device tree chasing an ACPI companion with a _DMA
1520          * object while we go. Stop if we find a device with an ACPI
1521          * companion containing a _DMA method.
1522          */
1523         do {
1524                 adev = ACPI_COMPANION(dma_dev);
1525                 if (adev && acpi_has_method(adev->handle, METHOD_NAME__DMA))
1526                         break;
1527
1528                 dma_dev = dma_dev->parent;
1529         } while (dma_dev);
1530
1531         if (!dma_dev)
1532                 return -ENODEV;
1533
1534         if (!acpi_has_method(adev->handle, METHOD_NAME__CRS)) {
1535                 acpi_handle_warn(adev->handle, "_DMA is valid only if _CRS is present\n");
1536                 return -EINVAL;
1537         }
1538
1539         ret = acpi_dev_get_dma_resources(adev, &list);
1540         if (ret > 0) {
1541                 list_for_each_entry(rentry, &list, node) {
1542                         if (dma_offset && rentry->offset != dma_offset) {
1543                                 ret = -EINVAL;
1544                                 dev_warn(dma_dev, "Can't handle multiple windows with different offsets\n");
1545                                 goto out;
1546                         }
1547                         dma_offset = rentry->offset;
1548
1549                         /* Take lower and upper limits */
1550                         if (rentry->res->start < dma_start)
1551                                 dma_start = rentry->res->start;
1552                         if (rentry->res->end > dma_end)
1553                                 dma_end = rentry->res->end;
1554                 }
1555
1556                 if (dma_start >= dma_end) {
1557                         ret = -EINVAL;
1558                         dev_dbg(dma_dev, "Invalid DMA regions configuration\n");
1559                         goto out;
1560                 }
1561
1562                 *dma_addr = dma_start - dma_offset;
1563                 len = dma_end - dma_start;
1564                 *size = max(len, len + 1);
1565                 *offset = dma_offset;
1566         }
1567  out:
1568         acpi_dev_free_resource_list(&list);
1569
1570         return ret >= 0 ? 0 : ret;
1571 }
1572
1573 #ifdef CONFIG_IOMMU_API
1574 int acpi_iommu_fwspec_init(struct device *dev, u32 id,
1575                            struct fwnode_handle *fwnode,
1576                            const struct iommu_ops *ops)
1577 {
1578         int ret = iommu_fwspec_init(dev, fwnode, ops);
1579
1580         if (!ret)
1581                 ret = iommu_fwspec_add_ids(dev, &id, 1);
1582
1583         return ret;
1584 }
1585
1586 static inline const struct iommu_ops *acpi_iommu_fwspec_ops(struct device *dev)
1587 {
1588         struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
1589
1590         return fwspec ? fwspec->ops : NULL;
1591 }
1592
1593 static const struct iommu_ops *acpi_iommu_configure_id(struct device *dev,
1594                                                        const u32 *id_in)
1595 {
1596         int err;
1597         const struct iommu_ops *ops;
1598
1599         /*
1600          * If we already translated the fwspec there is nothing left to do,
1601          * return the iommu_ops.
1602          */
1603         ops = acpi_iommu_fwspec_ops(dev);
1604         if (ops)
1605                 return ops;
1606
1607         err = iort_iommu_configure_id(dev, id_in);
1608         if (err && err != -EPROBE_DEFER)
1609                 err = viot_iommu_configure(dev);
1610
1611         /*
1612          * If we have reason to believe the IOMMU driver missed the initial
1613          * iommu_probe_device() call for dev, replay it to get things in order.
1614          */
1615         if (!err && dev->bus && !device_iommu_mapped(dev))
1616                 err = iommu_probe_device(dev);
1617
1618         /* Ignore all other errors apart from EPROBE_DEFER */
1619         if (err == -EPROBE_DEFER) {
1620                 return ERR_PTR(err);
1621         } else if (err) {
1622                 dev_dbg(dev, "Adding to IOMMU failed: %d\n", err);
1623                 return NULL;
1624         }
1625         return acpi_iommu_fwspec_ops(dev);
1626 }
1627
1628 #else /* !CONFIG_IOMMU_API */
1629
1630 int acpi_iommu_fwspec_init(struct device *dev, u32 id,
1631                            struct fwnode_handle *fwnode,
1632                            const struct iommu_ops *ops)
1633 {
1634         return -ENODEV;
1635 }
1636
1637 static const struct iommu_ops *acpi_iommu_configure_id(struct device *dev,
1638                                                        const u32 *id_in)
1639 {
1640         return NULL;
1641 }
1642
1643 #endif /* !CONFIG_IOMMU_API */
1644
1645 /**
1646  * acpi_dma_configure_id - Set-up DMA configuration for the device.
1647  * @dev: The pointer to the device
1648  * @attr: device dma attributes
1649  * @input_id: input device id const value pointer
1650  */
1651 int acpi_dma_configure_id(struct device *dev, enum dev_dma_attr attr,
1652                           const u32 *input_id)
1653 {
1654         const struct iommu_ops *iommu;
1655         u64 dma_addr = 0, size = 0;
1656
1657         if (attr == DEV_DMA_NOT_SUPPORTED) {
1658                 set_dma_ops(dev, &dma_dummy_ops);
1659                 return 0;
1660         }
1661
1662         acpi_arch_dma_setup(dev, &dma_addr, &size);
1663
1664         iommu = acpi_iommu_configure_id(dev, input_id);
1665         if (PTR_ERR(iommu) == -EPROBE_DEFER)
1666                 return -EPROBE_DEFER;
1667
1668         arch_setup_dma_ops(dev, dma_addr, size,
1669                                 iommu, attr == DEV_DMA_COHERENT);
1670
1671         return 0;
1672 }
1673 EXPORT_SYMBOL_GPL(acpi_dma_configure_id);
1674
1675 static void acpi_init_coherency(struct acpi_device *adev)
1676 {
1677         unsigned long long cca = 0;
1678         acpi_status status;
1679         struct acpi_device *parent = adev->parent;
1680
1681         if (parent && parent->flags.cca_seen) {
1682                 /*
1683                  * From ACPI spec, OSPM will ignore _CCA if an ancestor
1684                  * already saw one.
1685                  */
1686                 adev->flags.cca_seen = 1;
1687                 cca = parent->flags.coherent_dma;
1688         } else {
1689                 status = acpi_evaluate_integer(adev->handle, "_CCA",
1690                                                NULL, &cca);
1691                 if (ACPI_SUCCESS(status))
1692                         adev->flags.cca_seen = 1;
1693                 else if (!IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED))
1694                         /*
1695                          * If architecture does not specify that _CCA is
1696                          * required for DMA-able devices (e.g. x86),
1697                          * we default to _CCA=1.
1698                          */
1699                         cca = 1;
1700                 else
1701                         acpi_handle_debug(adev->handle,
1702                                           "ACPI device is missing _CCA.\n");
1703         }
1704
1705         adev->flags.coherent_dma = cca;
1706 }
1707
1708 static int acpi_check_serial_bus_slave(struct acpi_resource *ares, void *data)
1709 {
1710         bool *is_serial_bus_slave_p = data;
1711
1712         if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
1713                 return 1;
1714
1715         *is_serial_bus_slave_p = true;
1716
1717          /* no need to do more checking */
1718         return -1;
1719 }
1720
1721 static bool acpi_is_indirect_io_slave(struct acpi_device *device)
1722 {
1723         struct acpi_device *parent = device->parent;
1724         static const struct acpi_device_id indirect_io_hosts[] = {
1725                 {"HISI0191", 0},
1726                 {}
1727         };
1728
1729         return parent && !acpi_match_device_ids(parent, indirect_io_hosts);
1730 }
1731
1732 static bool acpi_device_enumeration_by_parent(struct acpi_device *device)
1733 {
1734         struct list_head resource_list;
1735         bool is_serial_bus_slave = false;
1736         static const struct acpi_device_id ignore_serial_bus_ids[] = {
1737         /*
1738          * These devices have multiple SerialBus resources and a client
1739          * device must be instantiated for each of them, each with
1740          * its own device id.
1741          * Normally we only instantiate one client device for the first
1742          * resource, using the ACPI HID as id. These special cases are handled
1743          * by the drivers/platform/x86/serial-multi-instantiate.c driver, which
1744          * knows which client device id to use for each resource.
1745          */
1746                 {"BSG1160", },
1747                 {"BSG2150", },
1748                 {"CSC3551", },
1749                 {"INT33FE", },
1750                 {"INT3515", },
1751                 /* Non-conforming _HID for Cirrus Logic already released */
1752                 {"CLSA0100", },
1753         /*
1754          * Some ACPI devs contain SerialBus resources even though they are not
1755          * attached to a serial bus at all.
1756          */
1757                 {"MSHW0028", },
1758         /*
1759          * HIDs of device with an UartSerialBusV2 resource for which userspace
1760          * expects a regular tty cdev to be created (instead of the in kernel
1761          * serdev) and which have a kernel driver which expects a platform_dev
1762          * such as the rfkill-gpio driver.
1763          */
1764                 {"BCM4752", },
1765                 {"LNV4752", },
1766                 {}
1767         };
1768
1769         if (acpi_is_indirect_io_slave(device))
1770                 return true;
1771
1772         /* Macs use device properties in lieu of _CRS resources */
1773         if (x86_apple_machine &&
1774             (fwnode_property_present(&device->fwnode, "spiSclkPeriod") ||
1775              fwnode_property_present(&device->fwnode, "i2cAddress") ||
1776              fwnode_property_present(&device->fwnode, "baud")))
1777                 return true;
1778
1779         if (!acpi_match_device_ids(device, ignore_serial_bus_ids))
1780                 return false;
1781
1782         INIT_LIST_HEAD(&resource_list);
1783         acpi_dev_get_resources(device, &resource_list,
1784                                acpi_check_serial_bus_slave,
1785                                &is_serial_bus_slave);
1786         acpi_dev_free_resource_list(&resource_list);
1787
1788         return is_serial_bus_slave;
1789 }
1790
1791 void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,
1792                              int type)
1793 {
1794         INIT_LIST_HEAD(&device->pnp.ids);
1795         device->device_type = type;
1796         device->handle = handle;
1797         device->parent = acpi_bus_get_parent(handle);
1798         fwnode_init(&device->fwnode, &acpi_device_fwnode_ops);
1799         acpi_set_device_status(device, ACPI_STA_DEFAULT);
1800         acpi_device_get_busid(device);
1801         acpi_set_pnp_ids(handle, &device->pnp, type);
1802         acpi_init_properties(device);
1803         acpi_bus_get_flags(device);
1804         device->flags.match_driver = false;
1805         device->flags.initialized = true;
1806         device->flags.enumeration_by_parent =
1807                 acpi_device_enumeration_by_parent(device);
1808         acpi_device_clear_enumerated(device);
1809         device_initialize(&device->dev);
1810         dev_set_uevent_suppress(&device->dev, true);
1811         acpi_init_coherency(device);
1812 }
1813
1814 static void acpi_scan_dep_init(struct acpi_device *adev)
1815 {
1816         struct acpi_dep_data *dep;
1817
1818         list_for_each_entry(dep, &acpi_dep_list, node) {
1819                 if (dep->consumer == adev->handle) {
1820                         if (dep->honor_dep)
1821                                 adev->flags.honor_deps = 1;
1822
1823                         adev->dep_unmet++;
1824                 }
1825         }
1826 }
1827
1828 void acpi_device_add_finalize(struct acpi_device *device)
1829 {
1830         dev_set_uevent_suppress(&device->dev, false);
1831         kobject_uevent(&device->dev.kobj, KOBJ_ADD);
1832 }
1833
1834 static void acpi_scan_init_status(struct acpi_device *adev)
1835 {
1836         if (acpi_bus_get_status(adev))
1837                 acpi_set_device_status(adev, 0);
1838 }
1839
1840 static int acpi_add_single_object(struct acpi_device **child,
1841                                   acpi_handle handle, int type, bool dep_init)
1842 {
1843         struct acpi_device *device;
1844         bool release_dep_lock = false;
1845         int result;
1846
1847         device = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
1848         if (!device)
1849                 return -ENOMEM;
1850
1851         acpi_init_device_object(device, handle, type);
1852         /*
1853          * Getting the status is delayed till here so that we can call
1854          * acpi_bus_get_status() and use its quirk handling.  Note that
1855          * this must be done before the get power-/wakeup_dev-flags calls.
1856          */
1857         if (type == ACPI_BUS_TYPE_DEVICE || type == ACPI_BUS_TYPE_PROCESSOR) {
1858                 if (dep_init) {
1859                         mutex_lock(&acpi_dep_list_lock);
1860                         /*
1861                          * Hold the lock until the acpi_tie_acpi_dev() call
1862                          * below to prevent concurrent acpi_scan_clear_dep()
1863                          * from deleting a dependency list entry without
1864                          * updating dep_unmet for the device.
1865                          */
1866                         release_dep_lock = true;
1867                         acpi_scan_dep_init(device);
1868                 }
1869                 acpi_scan_init_status(device);
1870         }
1871
1872         acpi_bus_get_power_flags(device);
1873         acpi_bus_get_wakeup_device_flags(device);
1874
1875         result = acpi_tie_acpi_dev(device);
1876
1877         if (release_dep_lock)
1878                 mutex_unlock(&acpi_dep_list_lock);
1879
1880         if (!result)
1881                 result = __acpi_device_add(device, acpi_device_release);
1882
1883         if (result) {
1884                 acpi_device_release(&device->dev);
1885                 return result;
1886         }
1887
1888         acpi_power_add_remove_device(device, true);
1889         acpi_device_add_finalize(device);
1890
1891         acpi_handle_debug(handle, "Added as %s, parent %s\n",
1892                           dev_name(&device->dev), device->parent ?
1893                                 dev_name(&device->parent->dev) : "(null)");
1894
1895         *child = device;
1896         return 0;
1897 }
1898
1899 static acpi_status acpi_get_resource_memory(struct acpi_resource *ares,
1900                                             void *context)
1901 {
1902         struct resource *res = context;
1903
1904         if (acpi_dev_resource_memory(ares, res))
1905                 return AE_CTRL_TERMINATE;
1906
1907         return AE_OK;
1908 }
1909
1910 static bool acpi_device_should_be_hidden(acpi_handle handle)
1911 {
1912         acpi_status status;
1913         struct resource res;
1914
1915         /* Check if it should ignore the UART device */
1916         if (!(spcr_uart_addr && acpi_has_method(handle, METHOD_NAME__CRS)))
1917                 return false;
1918
1919         /*
1920          * The UART device described in SPCR table is assumed to have only one
1921          * memory resource present. So we only look for the first one here.
1922          */
1923         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1924                                      acpi_get_resource_memory, &res);
1925         if (ACPI_FAILURE(status) || res.start != spcr_uart_addr)
1926                 return false;
1927
1928         acpi_handle_info(handle, "The UART device @%pa in SPCR table will be hidden\n",
1929                          &res.start);
1930
1931         return true;
1932 }
1933
1934 bool acpi_device_is_present(const struct acpi_device *adev)
1935 {
1936         return adev->status.present || adev->status.functional;
1937 }
1938
1939 static bool acpi_scan_handler_matching(struct acpi_scan_handler *handler,
1940                                        const char *idstr,
1941                                        const struct acpi_device_id **matchid)
1942 {
1943         const struct acpi_device_id *devid;
1944
1945         if (handler->match)
1946                 return handler->match(idstr, matchid);
1947
1948         for (devid = handler->ids; devid->id[0]; devid++)
1949                 if (!strcmp((char *)devid->id, idstr)) {
1950                         if (matchid)
1951                                 *matchid = devid;
1952
1953                         return true;
1954                 }
1955
1956         return false;
1957 }
1958
1959 static struct acpi_scan_handler *acpi_scan_match_handler(const char *idstr,
1960                                         const struct acpi_device_id **matchid)
1961 {
1962         struct acpi_scan_handler *handler;
1963
1964         list_for_each_entry(handler, &acpi_scan_handlers_list, list_node)
1965                 if (acpi_scan_handler_matching(handler, idstr, matchid))
1966                         return handler;
1967
1968         return NULL;
1969 }
1970
1971 void acpi_scan_hotplug_enabled(struct acpi_hotplug_profile *hotplug, bool val)
1972 {
1973         if (!!hotplug->enabled == !!val)
1974                 return;
1975
1976         mutex_lock(&acpi_scan_lock);
1977
1978         hotplug->enabled = val;
1979
1980         mutex_unlock(&acpi_scan_lock);
1981 }
1982
1983 static void acpi_scan_init_hotplug(struct acpi_device *adev)
1984 {
1985         struct acpi_hardware_id *hwid;
1986
1987         if (acpi_dock_match(adev->handle) || is_ejectable_bay(adev)) {
1988                 acpi_dock_add(adev);
1989                 return;
1990         }
1991         list_for_each_entry(hwid, &adev->pnp.ids, list) {
1992                 struct acpi_scan_handler *handler;
1993
1994                 handler = acpi_scan_match_handler(hwid->id, NULL);
1995                 if (handler) {
1996                         adev->flags.hotplug_notify = true;
1997                         break;
1998                 }
1999         }
2000 }
2001
2002 static u32 acpi_scan_check_dep(acpi_handle handle, bool check_dep)
2003 {
2004         struct acpi_handle_list dep_devices;
2005         acpi_status status;
2006         u32 count;
2007         int i;
2008
2009         /*
2010          * Check for _HID here to avoid deferring the enumeration of:
2011          * 1. PCI devices.
2012          * 2. ACPI nodes describing USB ports.
2013          * Still, checking for _HID catches more then just these cases ...
2014          */
2015         if (!check_dep || !acpi_has_method(handle, "_DEP") ||
2016             !acpi_has_method(handle, "_HID"))
2017                 return 0;
2018
2019         status = acpi_evaluate_reference(handle, "_DEP", NULL, &dep_devices);
2020         if (ACPI_FAILURE(status)) {
2021                 acpi_handle_debug(handle, "Failed to evaluate _DEP.\n");
2022                 return 0;
2023         }
2024
2025         for (count = 0, i = 0; i < dep_devices.count; i++) {
2026                 struct acpi_device_info *info;
2027                 struct acpi_dep_data *dep;
2028                 bool skip, honor_dep;
2029
2030                 status = acpi_get_object_info(dep_devices.handles[i], &info);
2031                 if (ACPI_FAILURE(status)) {
2032                         acpi_handle_debug(handle, "Error reading _DEP device info\n");
2033                         continue;
2034                 }
2035
2036                 skip = acpi_info_matches_ids(info, acpi_ignore_dep_ids);
2037                 honor_dep = acpi_info_matches_ids(info, acpi_honor_dep_ids);
2038                 kfree(info);
2039
2040                 if (skip)
2041                         continue;
2042
2043                 dep = kzalloc(sizeof(*dep), GFP_KERNEL);
2044                 if (!dep)
2045                         continue;
2046
2047                 count++;
2048
2049                 dep->supplier = dep_devices.handles[i];
2050                 dep->consumer = handle;
2051                 dep->honor_dep = honor_dep;
2052
2053                 mutex_lock(&acpi_dep_list_lock);
2054                 list_add_tail(&dep->node , &acpi_dep_list);
2055                 mutex_unlock(&acpi_dep_list_lock);
2056         }
2057
2058         return count;
2059 }
2060
2061 static bool acpi_bus_scan_second_pass;
2062
2063 static acpi_status acpi_bus_check_add(acpi_handle handle, bool check_dep,
2064                                       struct acpi_device **adev_p)
2065 {
2066         struct acpi_device *device = acpi_fetch_acpi_dev(handle);
2067         acpi_object_type acpi_type;
2068         int type;
2069
2070         if (device)
2071                 goto out;
2072
2073         if (ACPI_FAILURE(acpi_get_type(handle, &acpi_type)))
2074                 return AE_OK;
2075
2076         switch (acpi_type) {
2077         case ACPI_TYPE_DEVICE:
2078                 if (acpi_device_should_be_hidden(handle))
2079                         return AE_OK;
2080
2081                 /* Bail out if there are dependencies. */
2082                 if (acpi_scan_check_dep(handle, check_dep) > 0) {
2083                         acpi_bus_scan_second_pass = true;
2084                         return AE_CTRL_DEPTH;
2085                 }
2086
2087                 fallthrough;
2088         case ACPI_TYPE_ANY:     /* for ACPI_ROOT_OBJECT */
2089                 type = ACPI_BUS_TYPE_DEVICE;
2090                 break;
2091
2092         case ACPI_TYPE_PROCESSOR:
2093                 type = ACPI_BUS_TYPE_PROCESSOR;
2094                 break;
2095
2096         case ACPI_TYPE_THERMAL:
2097                 type = ACPI_BUS_TYPE_THERMAL;
2098                 break;
2099
2100         case ACPI_TYPE_POWER:
2101                 acpi_add_power_resource(handle);
2102                 fallthrough;
2103         default:
2104                 return AE_OK;
2105         }
2106
2107         /*
2108          * If check_dep is true at this point, the device has no dependencies,
2109          * or the creation of the device object would have been postponed above.
2110          */
2111         acpi_add_single_object(&device, handle, type, !check_dep);
2112         if (!device)
2113                 return AE_CTRL_DEPTH;
2114
2115         acpi_scan_init_hotplug(device);
2116
2117 out:
2118         if (!*adev_p)
2119                 *adev_p = device;
2120
2121         return AE_OK;
2122 }
2123
2124 static acpi_status acpi_bus_check_add_1(acpi_handle handle, u32 lvl_not_used,
2125                                         void *not_used, void **ret_p)
2126 {
2127         return acpi_bus_check_add(handle, true, (struct acpi_device **)ret_p);
2128 }
2129
2130 static acpi_status acpi_bus_check_add_2(acpi_handle handle, u32 lvl_not_used,
2131                                         void *not_used, void **ret_p)
2132 {
2133         return acpi_bus_check_add(handle, false, (struct acpi_device **)ret_p);
2134 }
2135
2136 static void acpi_default_enumeration(struct acpi_device *device)
2137 {
2138         /*
2139          * Do not enumerate devices with enumeration_by_parent flag set as
2140          * they will be enumerated by their respective parents.
2141          */
2142         if (!device->flags.enumeration_by_parent) {
2143                 acpi_create_platform_device(device, NULL);
2144                 acpi_device_set_enumerated(device);
2145         } else {
2146                 blocking_notifier_call_chain(&acpi_reconfig_chain,
2147                                              ACPI_RECONFIG_DEVICE_ADD, device);
2148         }
2149 }
2150
2151 static const struct acpi_device_id generic_device_ids[] = {
2152         {ACPI_DT_NAMESPACE_HID, },
2153         {"", },
2154 };
2155
2156 static int acpi_generic_device_attach(struct acpi_device *adev,
2157                                       const struct acpi_device_id *not_used)
2158 {
2159         /*
2160          * Since ACPI_DT_NAMESPACE_HID is the only ID handled here, the test
2161          * below can be unconditional.
2162          */
2163         if (adev->data.of_compatible)
2164                 acpi_default_enumeration(adev);
2165
2166         return 1;
2167 }
2168
2169 static struct acpi_scan_handler generic_device_handler = {
2170         .ids = generic_device_ids,
2171         .attach = acpi_generic_device_attach,
2172 };
2173
2174 static int acpi_scan_attach_handler(struct acpi_device *device)
2175 {
2176         struct acpi_hardware_id *hwid;
2177         int ret = 0;
2178
2179         list_for_each_entry(hwid, &device->pnp.ids, list) {
2180                 const struct acpi_device_id *devid;
2181                 struct acpi_scan_handler *handler;
2182
2183                 handler = acpi_scan_match_handler(hwid->id, &devid);
2184                 if (handler) {
2185                         if (!handler->attach) {
2186                                 device->pnp.type.platform_id = 0;
2187                                 continue;
2188                         }
2189                         device->handler = handler;
2190                         ret = handler->attach(device, devid);
2191                         if (ret > 0)
2192                                 break;
2193
2194                         device->handler = NULL;
2195                         if (ret < 0)
2196                                 break;
2197                 }
2198         }
2199
2200         return ret;
2201 }
2202
2203 static void acpi_bus_attach(struct acpi_device *device, bool first_pass)
2204 {
2205         struct acpi_device *child;
2206         bool skip = !first_pass && device->flags.visited;
2207         acpi_handle ejd;
2208         int ret;
2209
2210         if (skip)
2211                 goto ok;
2212
2213         if (ACPI_SUCCESS(acpi_bus_get_ejd(device->handle, &ejd)))
2214                 register_dock_dependent_device(device, ejd);
2215
2216         acpi_bus_get_status(device);
2217         /* Skip devices that are not ready for enumeration (e.g. not present) */
2218         if (!acpi_dev_ready_for_enumeration(device)) {
2219                 device->flags.initialized = false;
2220                 acpi_device_clear_enumerated(device);
2221                 device->flags.power_manageable = 0;
2222                 return;
2223         }
2224         if (device->handler)
2225                 goto ok;
2226
2227         if (!device->flags.initialized) {
2228                 device->flags.power_manageable =
2229                         device->power.states[ACPI_STATE_D0].flags.valid;
2230                 if (acpi_bus_init_power(device))
2231                         device->flags.power_manageable = 0;
2232
2233                 device->flags.initialized = true;
2234         } else if (device->flags.visited) {
2235                 goto ok;
2236         }
2237
2238         ret = acpi_scan_attach_handler(device);
2239         if (ret < 0)
2240                 return;
2241
2242         device->flags.match_driver = true;
2243         if (ret > 0 && !device->flags.enumeration_by_parent) {
2244                 acpi_device_set_enumerated(device);
2245                 goto ok;
2246         }
2247
2248         ret = device_attach(&device->dev);
2249         if (ret < 0)
2250                 return;
2251
2252         if (device->pnp.type.platform_id || device->flags.enumeration_by_parent)
2253                 acpi_default_enumeration(device);
2254         else
2255                 acpi_device_set_enumerated(device);
2256
2257  ok:
2258         list_for_each_entry(child, &device->children, node)
2259                 acpi_bus_attach(child, first_pass);
2260
2261         if (!skip && device->handler && device->handler->hotplug.notify_online)
2262                 device->handler->hotplug.notify_online(device);
2263 }
2264
2265 static int acpi_dev_get_first_consumer_dev_cb(struct acpi_dep_data *dep, void *data)
2266 {
2267         struct acpi_device *adev;
2268
2269         adev = acpi_bus_get_acpi_device(dep->consumer);
2270         if (adev) {
2271                 *(struct acpi_device **)data = adev;
2272                 return 1;
2273         }
2274         /* Continue parsing if the device object is not present. */
2275         return 0;
2276 }
2277
2278 struct acpi_scan_clear_dep_work {
2279         struct work_struct work;
2280         struct acpi_device *adev;
2281 };
2282
2283 static void acpi_scan_clear_dep_fn(struct work_struct *work)
2284 {
2285         struct acpi_scan_clear_dep_work *cdw;
2286
2287         cdw = container_of(work, struct acpi_scan_clear_dep_work, work);
2288
2289         acpi_scan_lock_acquire();
2290         acpi_bus_attach(cdw->adev, true);
2291         acpi_scan_lock_release();
2292
2293         acpi_dev_put(cdw->adev);
2294         kfree(cdw);
2295 }
2296
2297 static bool acpi_scan_clear_dep_queue(struct acpi_device *adev)
2298 {
2299         struct acpi_scan_clear_dep_work *cdw;
2300
2301         if (adev->dep_unmet)
2302                 return false;
2303
2304         cdw = kmalloc(sizeof(*cdw), GFP_KERNEL);
2305         if (!cdw)
2306                 return false;
2307
2308         cdw->adev = adev;
2309         INIT_WORK(&cdw->work, acpi_scan_clear_dep_fn);
2310         /*
2311          * Since the work function may block on the lock until the entire
2312          * initial enumeration of devices is complete, put it into the unbound
2313          * workqueue.
2314          */
2315         queue_work(system_unbound_wq, &cdw->work);
2316
2317         return true;
2318 }
2319
2320 static int acpi_scan_clear_dep(struct acpi_dep_data *dep, void *data)
2321 {
2322         struct acpi_device *adev = acpi_bus_get_acpi_device(dep->consumer);
2323
2324         if (adev) {
2325                 adev->dep_unmet--;
2326                 if (!acpi_scan_clear_dep_queue(adev))
2327                         acpi_dev_put(adev);
2328         }
2329
2330         list_del(&dep->node);
2331         kfree(dep);
2332
2333         return 0;
2334 }
2335
2336 /**
2337  * acpi_walk_dep_device_list - Apply a callback to every entry in acpi_dep_list
2338  * @handle:     The ACPI handle of the supplier device
2339  * @callback:   Pointer to the callback function to apply
2340  * @data:       Pointer to some data to pass to the callback
2341  *
2342  * The return value of the callback determines this function's behaviour. If 0
2343  * is returned we continue to iterate over acpi_dep_list. If a positive value
2344  * is returned then the loop is broken but this function returns 0. If a
2345  * negative value is returned by the callback then the loop is broken and that
2346  * value is returned as the final error.
2347  */
2348 static int acpi_walk_dep_device_list(acpi_handle handle,
2349                                 int (*callback)(struct acpi_dep_data *, void *),
2350                                 void *data)
2351 {
2352         struct acpi_dep_data *dep, *tmp;
2353         int ret = 0;
2354
2355         mutex_lock(&acpi_dep_list_lock);
2356         list_for_each_entry_safe(dep, tmp, &acpi_dep_list, node) {
2357                 if (dep->supplier == handle) {
2358                         ret = callback(dep, data);
2359                         if (ret)
2360                                 break;
2361                 }
2362         }
2363         mutex_unlock(&acpi_dep_list_lock);
2364
2365         return ret > 0 ? 0 : ret;
2366 }
2367
2368 /**
2369  * acpi_dev_clear_dependencies - Inform consumers that the device is now active
2370  * @supplier: Pointer to the supplier &struct acpi_device
2371  *
2372  * Clear dependencies on the given device.
2373  */
2374 void acpi_dev_clear_dependencies(struct acpi_device *supplier)
2375 {
2376         acpi_walk_dep_device_list(supplier->handle, acpi_scan_clear_dep, NULL);
2377 }
2378 EXPORT_SYMBOL_GPL(acpi_dev_clear_dependencies);
2379
2380 /**
2381  * acpi_dev_ready_for_enumeration - Check if the ACPI device is ready for enumeration
2382  * @device: Pointer to the &struct acpi_device to check
2383  *
2384  * Check if the device is present and has no unmet dependencies.
2385  *
2386  * Return true if the device is ready for enumeratino. Otherwise, return false.
2387  */
2388 bool acpi_dev_ready_for_enumeration(const struct acpi_device *device)
2389 {
2390         if (device->flags.honor_deps && device->dep_unmet)
2391                 return false;
2392
2393         return acpi_device_is_present(device);
2394 }
2395 EXPORT_SYMBOL_GPL(acpi_dev_ready_for_enumeration);
2396
2397 /**
2398  * acpi_dev_get_first_consumer_dev - Return ACPI device dependent on @supplier
2399  * @supplier: Pointer to the dependee device
2400  *
2401  * Returns the first &struct acpi_device which declares itself dependent on
2402  * @supplier via the _DEP buffer, parsed from the acpi_dep_list.
2403  *
2404  * The caller is responsible for putting the reference to adev when it is no
2405  * longer needed.
2406  */
2407 struct acpi_device *acpi_dev_get_first_consumer_dev(struct acpi_device *supplier)
2408 {
2409         struct acpi_device *adev = NULL;
2410
2411         acpi_walk_dep_device_list(supplier->handle,
2412                                   acpi_dev_get_first_consumer_dev_cb, &adev);
2413
2414         return adev;
2415 }
2416 EXPORT_SYMBOL_GPL(acpi_dev_get_first_consumer_dev);
2417
2418 /**
2419  * acpi_bus_scan - Add ACPI device node objects in a given namespace scope.
2420  * @handle: Root of the namespace scope to scan.
2421  *
2422  * Scan a given ACPI tree (probably recently hot-plugged) and create and add
2423  * found devices.
2424  *
2425  * If no devices were found, -ENODEV is returned, but it does not mean that
2426  * there has been a real error.  There just have been no suitable ACPI objects
2427  * in the table trunk from which the kernel could create a device and add an
2428  * appropriate driver.
2429  *
2430  * Must be called under acpi_scan_lock.
2431  */
2432 int acpi_bus_scan(acpi_handle handle)
2433 {
2434         struct acpi_device *device = NULL;
2435
2436         acpi_bus_scan_second_pass = false;
2437
2438         /* Pass 1: Avoid enumerating devices with missing dependencies. */
2439
2440         if (ACPI_SUCCESS(acpi_bus_check_add(handle, true, &device)))
2441                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
2442                                     acpi_bus_check_add_1, NULL, NULL,
2443                                     (void **)&device);
2444
2445         if (!device)
2446                 return -ENODEV;
2447
2448         acpi_bus_attach(device, true);
2449
2450         if (!acpi_bus_scan_second_pass)
2451                 return 0;
2452
2453         /* Pass 2: Enumerate all of the remaining devices. */
2454
2455         device = NULL;
2456
2457         if (ACPI_SUCCESS(acpi_bus_check_add(handle, false, &device)))
2458                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
2459                                     acpi_bus_check_add_2, NULL, NULL,
2460                                     (void **)&device);
2461
2462         acpi_bus_attach(device, false);
2463
2464         return 0;
2465 }
2466 EXPORT_SYMBOL(acpi_bus_scan);
2467
2468 /**
2469  * acpi_bus_trim - Detach scan handlers and drivers from ACPI device objects.
2470  * @adev: Root of the ACPI namespace scope to walk.
2471  *
2472  * Must be called under acpi_scan_lock.
2473  */
2474 void acpi_bus_trim(struct acpi_device *adev)
2475 {
2476         struct acpi_scan_handler *handler = adev->handler;
2477         struct acpi_device *child;
2478
2479         list_for_each_entry_reverse(child, &adev->children, node)
2480                 acpi_bus_trim(child);
2481
2482         adev->flags.match_driver = false;
2483         if (handler) {
2484                 if (handler->detach)
2485                         handler->detach(adev);
2486
2487                 adev->handler = NULL;
2488         } else {
2489                 device_release_driver(&adev->dev);
2490         }
2491         /*
2492          * Most likely, the device is going away, so put it into D3cold before
2493          * that.
2494          */
2495         acpi_device_set_power(adev, ACPI_STATE_D3_COLD);
2496         adev->flags.initialized = false;
2497         acpi_device_clear_enumerated(adev);
2498 }
2499 EXPORT_SYMBOL_GPL(acpi_bus_trim);
2500
2501 int acpi_bus_register_early_device(int type)
2502 {
2503         struct acpi_device *device = NULL;
2504         int result;
2505
2506         result = acpi_add_single_object(&device, NULL, type, false);
2507         if (result)
2508                 return result;
2509
2510         device->flags.match_driver = true;
2511         return device_attach(&device->dev);
2512 }
2513 EXPORT_SYMBOL_GPL(acpi_bus_register_early_device);
2514
2515 static void acpi_bus_scan_fixed(void)
2516 {
2517         if (!(acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON)) {
2518                 struct acpi_device *adev = NULL;
2519
2520                 acpi_add_single_object(&adev, NULL, ACPI_BUS_TYPE_POWER_BUTTON,
2521                                        false);
2522                 if (adev) {
2523                         adev->flags.match_driver = true;
2524                         if (device_attach(&adev->dev) >= 0)
2525                                 device_init_wakeup(&adev->dev, true);
2526                         else
2527                                 dev_dbg(&adev->dev, "No driver\n");
2528                 }
2529         }
2530
2531         if (!(acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON)) {
2532                 struct acpi_device *adev = NULL;
2533
2534                 acpi_add_single_object(&adev, NULL, ACPI_BUS_TYPE_SLEEP_BUTTON,
2535                                        false);
2536                 if (adev) {
2537                         adev->flags.match_driver = true;
2538                         if (device_attach(&adev->dev) < 0)
2539                                 dev_dbg(&adev->dev, "No driver\n");
2540                 }
2541         }
2542 }
2543
2544 static void __init acpi_get_spcr_uart_addr(void)
2545 {
2546         acpi_status status;
2547         struct acpi_table_spcr *spcr_ptr;
2548
2549         status = acpi_get_table(ACPI_SIG_SPCR, 0,
2550                                 (struct acpi_table_header **)&spcr_ptr);
2551         if (ACPI_FAILURE(status)) {
2552                 pr_warn("STAO table present, but SPCR is missing\n");
2553                 return;
2554         }
2555
2556         spcr_uart_addr = spcr_ptr->serial_port.address;
2557         acpi_put_table((struct acpi_table_header *)spcr_ptr);
2558 }
2559
2560 static bool acpi_scan_initialized;
2561
2562 void __init acpi_scan_init(void)
2563 {
2564         acpi_status status;
2565         struct acpi_table_stao *stao_ptr;
2566
2567         acpi_pci_root_init();
2568         acpi_pci_link_init();
2569         acpi_processor_init();
2570         acpi_platform_init();
2571         acpi_lpss_init();
2572         acpi_apd_init();
2573         acpi_cmos_rtc_init();
2574         acpi_container_init();
2575         acpi_memory_hotplug_init();
2576         acpi_watchdog_init();
2577         acpi_pnp_init();
2578         acpi_int340x_thermal_init();
2579         acpi_amba_init();
2580         acpi_init_lpit();
2581
2582         acpi_scan_add_handler(&generic_device_handler);
2583
2584         /*
2585          * If there is STAO table, check whether it needs to ignore the UART
2586          * device in SPCR table.
2587          */
2588         status = acpi_get_table(ACPI_SIG_STAO, 0,
2589                                 (struct acpi_table_header **)&stao_ptr);
2590         if (ACPI_SUCCESS(status)) {
2591                 if (stao_ptr->header.length > sizeof(struct acpi_table_stao))
2592                         pr_info("STAO Name List not yet supported.\n");
2593
2594                 if (stao_ptr->ignore_uart)
2595                         acpi_get_spcr_uart_addr();
2596
2597                 acpi_put_table((struct acpi_table_header *)stao_ptr);
2598         }
2599
2600         acpi_gpe_apply_masked_gpes();
2601         acpi_update_all_gpes();
2602
2603         /*
2604          * Although we call __add_memory() that is documented to require the
2605          * device_hotplug_lock, it is not necessary here because this is an
2606          * early code when userspace or any other code path cannot trigger
2607          * hotplug/hotunplug operations.
2608          */
2609         mutex_lock(&acpi_scan_lock);
2610         /*
2611          * Enumerate devices in the ACPI namespace.
2612          */
2613         if (acpi_bus_scan(ACPI_ROOT_OBJECT))
2614                 goto unlock;
2615
2616         acpi_root = acpi_fetch_acpi_dev(ACPI_ROOT_OBJECT);
2617         if (!acpi_root)
2618                 goto unlock;
2619
2620         /* Fixed feature devices do not exist on HW-reduced platform */
2621         if (!acpi_gbl_reduced_hardware)
2622                 acpi_bus_scan_fixed();
2623
2624         acpi_turn_off_unused_power_resources();
2625
2626         acpi_scan_initialized = true;
2627
2628 unlock:
2629         mutex_unlock(&acpi_scan_lock);
2630 }
2631
2632 static struct acpi_probe_entry *ape;
2633 static int acpi_probe_count;
2634 static DEFINE_MUTEX(acpi_probe_mutex);
2635
2636 static int __init acpi_match_madt(union acpi_subtable_headers *header,
2637                                   const unsigned long end)
2638 {
2639         if (!ape->subtable_valid || ape->subtable_valid(&header->common, ape))
2640                 if (!ape->probe_subtbl(header, end))
2641                         acpi_probe_count++;
2642
2643         return 0;
2644 }
2645
2646 int __init __acpi_probe_device_table(struct acpi_probe_entry *ap_head, int nr)
2647 {
2648         int count = 0;
2649
2650         if (acpi_disabled)
2651                 return 0;
2652
2653         mutex_lock(&acpi_probe_mutex);
2654         for (ape = ap_head; nr; ape++, nr--) {
2655                 if (ACPI_COMPARE_NAMESEG(ACPI_SIG_MADT, ape->id)) {
2656                         acpi_probe_count = 0;
2657                         acpi_table_parse_madt(ape->type, acpi_match_madt, 0);
2658                         count += acpi_probe_count;
2659                 } else {
2660                         int res;
2661                         res = acpi_table_parse(ape->id, ape->probe_table);
2662                         if (!res)
2663                                 count++;
2664                 }
2665         }
2666         mutex_unlock(&acpi_probe_mutex);
2667
2668         return count;
2669 }
2670
2671 static void acpi_table_events_fn(struct work_struct *work)
2672 {
2673         acpi_scan_lock_acquire();
2674         acpi_bus_scan(ACPI_ROOT_OBJECT);
2675         acpi_scan_lock_release();
2676
2677         kfree(work);
2678 }
2679
2680 void acpi_scan_table_notify(void)
2681 {
2682         struct work_struct *work;
2683
2684         if (!acpi_scan_initialized)
2685                 return;
2686
2687         work = kmalloc(sizeof(*work), GFP_KERNEL);
2688         if (!work)
2689                 return;
2690
2691         INIT_WORK(work, acpi_table_events_fn);
2692         schedule_work(work);
2693 }
2694
2695 int acpi_reconfig_notifier_register(struct notifier_block *nb)
2696 {
2697         return blocking_notifier_chain_register(&acpi_reconfig_chain, nb);
2698 }
2699 EXPORT_SYMBOL(acpi_reconfig_notifier_register);
2700
2701 int acpi_reconfig_notifier_unregister(struct notifier_block *nb)
2702 {
2703         return blocking_notifier_chain_unregister(&acpi_reconfig_chain, nb);
2704 }
2705 EXPORT_SYMBOL(acpi_reconfig_notifier_unregister);