drivers/acpi/scan.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * scan.c - support for transforming the ACPI namespace into individual objects
   4  */
   5
   6 #define pr_fmt(fmt) "ACPI: " fmt
   7
   8 #include <linux/module.h>
   9 #include <linux/init.h>
  10 #include <linux/slab.h>
  11 #include <linux/kernel.h>
  12 #include <linux/acpi.h>
  13 #include <linux/acpi_iort.h>
  14 #include <linux/acpi_viot.h>
  15 #include <linux/iommu.h>
  16 #include <linux/signal.h>
  17 #include <linux/kthread.h>
  18 #include <linux/dmi.h>
  19 #include <linux/dma-map-ops.h>
  20 #include <linux/platform_data/x86/apple.h>
  21 #include <linux/pgtable.h>
  22 #include <linux/crc32.h>
  23 #include <linux/dma-direct.h>
  24
  25 #include "internal.h"
  26 #include "sleep.h"
  27
  28 #define ACPI_BUS_CLASS                  "system_bus"
  29 #define ACPI_BUS_HID                    "LNXSYBUS"
  30 #define ACPI_BUS_DEVICE_NAME            "System Bus"
  31
  32 #define INVALID_ACPI_HANDLE     ((acpi_handle)ZERO_PAGE(0))
  33
  34 static const char *dummy_hid = "device";
  35
  36 static LIST_HEAD(acpi_dep_list);
  37 static DEFINE_MUTEX(acpi_dep_list_lock);
  38 LIST_HEAD(acpi_bus_id_list);
  39 static DEFINE_MUTEX(acpi_scan_lock);
  40 static LIST_HEAD(acpi_scan_handlers_list);
  41 DEFINE_MUTEX(acpi_device_lock);
  42 LIST_HEAD(acpi_wakeup_device_list);
  43 static DEFINE_MUTEX(acpi_hp_context_lock);
  44
  45 /*
  46  * The UART device described by the SPCR table is the only object which needs
  47  * special-casing. Everything else is covered by ACPI namespace paths in STAO
  48  * table.
  49  */
  50 static u64 spcr_uart_addr;
  51
  52 void acpi_scan_lock_acquire(void)
  53 {
  54         mutex_lock(&acpi_scan_lock);
  55 }
  56 EXPORT_SYMBOL_GPL(acpi_scan_lock_acquire);
  57
  58 void acpi_scan_lock_release(void)
  59 {
  60         mutex_unlock(&acpi_scan_lock);
  61 }
  62 EXPORT_SYMBOL_GPL(acpi_scan_lock_release);
  63
  64 void acpi_lock_hp_context(void)
  65 {
  66         mutex_lock(&acpi_hp_context_lock);
  67 }
  68
  69 void acpi_unlock_hp_context(void)
  70 {
  71         mutex_unlock(&acpi_hp_context_lock);
  72 }
  73
  74 void acpi_initialize_hp_context(struct acpi_device *adev,
  75                                 struct acpi_hotplug_context *hp,
  76                                 int (*notify)(struct acpi_device *, u32),
  77                                 void (*uevent)(struct acpi_device *, u32))
  78 {
  79         acpi_lock_hp_context();
  80         hp->notify = notify;
  81         hp->uevent = uevent;
  82         acpi_set_hp_context(adev, hp);
  83         acpi_unlock_hp_context();
  84 }
  85 EXPORT_SYMBOL_GPL(acpi_initialize_hp_context);
  86
  87 int acpi_scan_add_handler(struct acpi_scan_handler *handler)
  88 {
  89         if (!handler)
  90                 return -EINVAL;
  91
  92         list_add_tail(&handler->list_node, &acpi_scan_handlers_list);
  93         return 0;
  94 }
  95
  96 int acpi_scan_add_handler_with_hotplug(struct acpi_scan_handler *handler,
  97                                        const char *hotplug_profile_name)
  98 {
  99         int error;
 100
 101         error = acpi_scan_add_handler(handler);
 102         if (error)
 103                 return error;
 104
 105         acpi_sysfs_add_hotplug_profile(&handler->hotplug, hotplug_profile_name);
 106         return 0;
 107 }
 108
 109 bool acpi_scan_is_offline(struct acpi_device *adev, bool uevent)
 110 {
 111         struct acpi_device_physical_node *pn;
 112         bool offline = true;
 113         char *envp[] = { "EVENT=offline", NULL };
 114
 115         /*
 116          * acpi_container_offline() calls this for all of the container's
 117          * children under the container's physical_node_lock lock.
 118          */
 119         mutex_lock_nested(&adev->physical_node_lock, SINGLE_DEPTH_NESTING);
 120
 121         list_for_each_entry(pn, &adev->physical_node_list, node)
 122                 if (device_supports_offline(pn->dev) && !pn->dev->offline) {
 123                         if (uevent)
 124                                 kobject_uevent_env(&pn->dev->kobj, KOBJ_CHANGE, envp);
 125
 126                         offline = false;
 127                         break;
 128                 }
 129
 130         mutex_unlock(&adev->physical_node_lock);
 131         return offline;
 132 }
 133
 134 static acpi_status acpi_bus_offline(acpi_handle handle, u32 lvl, void *data,
 135                                     void **ret_p)
 136 {
 137         struct acpi_device *device = acpi_fetch_acpi_dev(handle);
 138         struct acpi_device_physical_node *pn;
 139         bool second_pass = (bool)data;
 140         acpi_status status = AE_OK;
 141
 142         if (!device)
 143                 return AE_OK;
 144
 145         if (device->handler && !device->handler->hotplug.enabled) {
 146                 *ret_p = &device->dev;
 147                 return AE_SUPPORT;
 148         }
 149
 150         mutex_lock(&device->physical_node_lock);
 151
 152         list_for_each_entry(pn, &device->physical_node_list, node) {
 153                 int ret;
 154
 155                 if (second_pass) {
 156                         /* Skip devices offlined by the first pass. */
 157                         if (pn->put_online)
 158                                 continue;
 159                 } else {
 160                         pn->put_online = false;
 161                 }
 162                 ret = device_offline(pn->dev);
 163                 if (ret >= 0) {
 164                         pn->put_online = !ret;
 165                 } else {
 166                         *ret_p = pn->dev;
 167                         if (second_pass) {
 168                                 status = AE_ERROR;
 169                                 break;
 170                         }
 171                 }
 172         }
 173
 174         mutex_unlock(&device->physical_node_lock);
 175
 176         return status;
 177 }
 178
 179 static acpi_status acpi_bus_online(acpi_handle handle, u32 lvl, void *data,
 180                                    void **ret_p)
 181 {
 182         struct acpi_device *device = acpi_fetch_acpi_dev(handle);
 183         struct acpi_device_physical_node *pn;
 184
 185         if (!device)
 186                 return AE_OK;
 187
 188         mutex_lock(&device->physical_node_lock);
 189
 190         list_for_each_entry(pn, &device->physical_node_list, node)
 191                 if (pn->put_online) {
 192                         device_online(pn->dev);
 193                         pn->put_online = false;
 194                 }
 195
 196         mutex_unlock(&device->physical_node_lock);
 197
 198         return AE_OK;
 199 }
 200
 201 static int acpi_scan_try_to_offline(struct acpi_device *device)
 202 {
 203         acpi_handle handle = device->handle;
 204         struct device *errdev = NULL;
 205         acpi_status status;
 206
 207         /*
 208          * Carry out two passes here and ignore errors in the first pass,
 209          * because if the devices in question are memory blocks and
 210          * CONFIG_MEMCG is set, one of the blocks may hold data structures
 211          * that the other blocks depend on, but it is not known in advance which
 212          * block holds them.
 213          *
 214          * If the first pass is successful, the second one isn't needed, though.
 215          */
 216         status = acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
 217                                      NULL, acpi_bus_offline, (void *)false,
 218                                      (void **)&errdev);
 219         if (status == AE_SUPPORT) {
 220                 dev_warn(errdev, "Offline disabled.\n");
 221                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
 222                                     acpi_bus_online, NULL, NULL, NULL);
 223                 return -EPERM;
 224         }
 225         acpi_bus_offline(handle, 0, (void *)false, (void **)&errdev);
 226         if (errdev) {
 227                 errdev = NULL;
 228                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
 229                                     NULL, acpi_bus_offline, (void *)true,
 230                                     (void **)&errdev);
 231                 if (!errdev)
 232                         acpi_bus_offline(handle, 0, (void *)true,
 233                                          (void **)&errdev);
 234
 235                 if (errdev) {
 236                         dev_warn(errdev, "Offline failed.\n");
 237                         acpi_bus_online(handle, 0, NULL, NULL);
 238                         acpi_walk_namespace(ACPI_TYPE_ANY, handle,
 239                                             ACPI_UINT32_MAX, acpi_bus_online,
 240                                             NULL, NULL, NULL);
 241                         return -EBUSY;
 242                 }
 243         }
 244         return 0;
 245 }
 246
 247 static int acpi_scan_hot_remove(struct acpi_device *device)
 248 {
 249         acpi_handle handle = device->handle;
 250         unsigned long long sta;
 251         acpi_status status;
 252
 253         if (device->handler && device->handler->hotplug.demand_offline) {
 254                 if (!acpi_scan_is_offline(device, true))
 255                         return -EBUSY;
 256         } else {
 257                 int error = acpi_scan_try_to_offline(device);
 258                 if (error)
 259                         return error;
 260         }
 261
 262         acpi_handle_debug(handle, "Ejecting\n");
 263
 264         acpi_bus_trim(device);
 265
 266         acpi_evaluate_lck(handle, 0);
 267         /*
 268          * TBD: _EJD support.
 269          */
 270         status = acpi_evaluate_ej0(handle);
 271         if (status == AE_NOT_FOUND)
 272                 return -ENODEV;
 273         else if (ACPI_FAILURE(status))
 274                 return -EIO;
 275
 276         /*
 277          * Verify if eject was indeed successful.  If not, log an error
 278          * message.  No need to call _OST since _EJ0 call was made OK.
 279          */
 280         status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
 281         if (ACPI_FAILURE(status)) {
 282                 acpi_handle_warn(handle,
 283                         "Status check after eject failed (0x%x)\n", status);
 284         } else if (sta & ACPI_STA_DEVICE_ENABLED) {
 285                 acpi_handle_warn(handle,
 286                         "Eject incomplete - status 0x%llx\n", sta);
 287         }
 288
 289         return 0;
 290 }
 291
 292 static int acpi_scan_device_not_present(struct acpi_device *adev)
 293 {
 294         if (!acpi_device_enumerated(adev)) {
 295                 dev_warn(&adev->dev, "Still not present\n");
 296                 return -EALREADY;
 297         }
 298         acpi_bus_trim(adev);
 299         return 0;
 300 }
 301
 302 static int acpi_scan_device_check(struct acpi_device *adev)
 303 {
 304         int error;
 305
 306         acpi_bus_get_status(adev);
 307         if (adev->status.present || adev->status.functional) {
 308                 /*
 309                  * This function is only called for device objects for which
 310                  * matching scan handlers exist.  The only situation in which
 311                  * the scan handler is not attached to this device object yet
 312                  * is when the device has just appeared (either it wasn't
 313                  * present at all before or it was removed and then added
 314                  * again).
 315                  */
 316                 if (adev->handler) {
 317                         dev_warn(&adev->dev, "Already enumerated\n");
 318                         return -EALREADY;
 319                 }
 320                 error = acpi_bus_scan(adev->handle);
 321                 if (error) {
 322                         dev_warn(&adev->dev, "Namespace scan failure\n");
 323                         return error;
 324                 }
 325                 if (!adev->handler) {
 326                         dev_warn(&adev->dev, "Enumeration failure\n");
 327                         error = -ENODEV;
 328                 }
 329         } else {
 330                 error = acpi_scan_device_not_present(adev);
 331         }
 332         return error;
 333 }
 334
 335 static int acpi_scan_bus_check(struct acpi_device *adev, void *not_used)
 336 {
 337         struct acpi_scan_handler *handler = adev->handler;
 338         int error;
 339
 340         acpi_bus_get_status(adev);
 341         if (!(adev->status.present || adev->status.functional)) {
 342                 acpi_scan_device_not_present(adev);
 343                 return 0;
 344         }
 345         if (handler && handler->hotplug.scan_dependent)
 346                 return handler->hotplug.scan_dependent(adev);
 347
 348         error = acpi_bus_scan(adev->handle);
 349         if (error) {
 350                 dev_warn(&adev->dev, "Namespace scan failure\n");
 351                 return error;
 352         }
 353         return acpi_dev_for_each_child(adev, acpi_scan_bus_check, NULL);
 354 }
 355
 356 static int acpi_generic_hotplug_event(struct acpi_device *adev, u32 type)
 357 {
 358         switch (type) {
 359         case ACPI_NOTIFY_BUS_CHECK:
 360                 return acpi_scan_bus_check(adev, NULL);
 361         case ACPI_NOTIFY_DEVICE_CHECK:
 362                 return acpi_scan_device_check(adev);
 363         case ACPI_NOTIFY_EJECT_REQUEST:
 364         case ACPI_OST_EC_OSPM_EJECT:
 365                 if (adev->handler && !adev->handler->hotplug.enabled) {
 366                         dev_info(&adev->dev, "Eject disabled\n");
 367                         return -EPERM;
 368                 }
 369                 acpi_evaluate_ost(adev->handle, ACPI_NOTIFY_EJECT_REQUEST,
 370                                   ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
 371                 return acpi_scan_hot_remove(adev);
 372         }
 373         return -EINVAL;
 374 }
 375
 376 void acpi_device_hotplug(struct acpi_device *adev, u32 src)
 377 {
 378         u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
 379         int error = -ENODEV;
 380
 381         lock_device_hotplug();
 382         mutex_lock(&acpi_scan_lock);
 383
 384         /*
 385          * The device object's ACPI handle cannot become invalid as long as we
 386          * are holding acpi_scan_lock, but it might have become invalid before
 387          * that lock was acquired.
 388          */
 389         if (adev->handle == INVALID_ACPI_HANDLE)
 390                 goto err_out;
 391
 392         if (adev->flags.is_dock_station) {
 393                 error = dock_notify(adev, src);
 394         } else if (adev->flags.hotplug_notify) {
 395                 error = acpi_generic_hotplug_event(adev, src);
 396         } else {
 397                 int (*notify)(struct acpi_device *, u32);
 398
 399                 acpi_lock_hp_context();
 400                 notify = adev->hp ? adev->hp->notify : NULL;
 401                 acpi_unlock_hp_context();
 402                 /*
 403                  * There may be additional notify handlers for device objects
 404                  * without the .event() callback, so ignore them here.
 405                  */
 406                 if (notify)
 407                         error = notify(adev, src);
 408                 else
 409                         goto out;
 410         }
 411         switch (error) {
 412         case 0:
 413                 ost_code = ACPI_OST_SC_SUCCESS;
 414                 break;
 415         case -EPERM:
 416                 ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
 417                 break;
 418         case -EBUSY:
 419                 ost_code = ACPI_OST_SC_DEVICE_BUSY;
 420                 break;
 421         default:
 422                 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
 423                 break;
 424         }
 425
 426  err_out:
 427         acpi_evaluate_ost(adev->handle, src, ost_code, NULL);
 428
 429  out:
 430         acpi_put_acpi_dev(adev);
 431         mutex_unlock(&acpi_scan_lock);
 432         unlock_device_hotplug();
 433 }
 434
 435 static void acpi_free_power_resources_lists(struct acpi_device *device)
 436 {
 437         int i;
 438
 439         if (device->wakeup.flags.valid)
 440                 acpi_power_resources_list_free(&device->wakeup.resources);
 441
 442         if (!device->power.flags.power_resources)
 443                 return;
 444
 445         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
 446                 struct acpi_device_power_state *ps = &device->power.states[i];
 447                 acpi_power_resources_list_free(&ps->resources);
 448         }
 449 }
 450
 451 static void acpi_device_release(struct device *dev)
 452 {
 453         struct acpi_device *acpi_dev = to_acpi_device(dev);
 454
 455         acpi_free_properties(acpi_dev);
 456         acpi_free_pnp_ids(&acpi_dev->pnp);
 457         acpi_free_power_resources_lists(acpi_dev);
 458         kfree(acpi_dev);
 459 }
 460
 461 static void acpi_device_del(struct acpi_device *device)
 462 {
 463         struct acpi_device_bus_id *acpi_device_bus_id;
 464
 465         mutex_lock(&acpi_device_lock);
 466
 467         list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node)
 468                 if (!strcmp(acpi_device_bus_id->bus_id,
 469                             acpi_device_hid(device))) {
 470                         ida_free(&acpi_device_bus_id->instance_ida,
 471                                  device->pnp.instance_no);
 472                         if (ida_is_empty(&acpi_device_bus_id->instance_ida)) {
 473                                 list_del(&acpi_device_bus_id->node);
 474                                 kfree_const(acpi_device_bus_id->bus_id);
 475                                 kfree(acpi_device_bus_id);
 476                         }
 477                         break;
 478                 }
 479
 480         list_del(&device->wakeup_list);
 481
 482         mutex_unlock(&acpi_device_lock);
 483
 484         acpi_power_add_remove_device(device, false);
 485         acpi_device_remove_files(device);
 486         if (device->remove)
 487                 device->remove(device);
 488
 489         device_del(&device->dev);
 490 }
 491
 492 static BLOCKING_NOTIFIER_HEAD(acpi_reconfig_chain);
 493
 494 static LIST_HEAD(acpi_device_del_list);
 495 static DEFINE_MUTEX(acpi_device_del_lock);
 496
 497 static void acpi_device_del_work_fn(struct work_struct *work_not_used)
 498 {
 499         for (;;) {
 500                 struct acpi_device *adev;
 501
 502                 mutex_lock(&acpi_device_del_lock);
 503
 504                 if (list_empty(&acpi_device_del_list)) {
 505                         mutex_unlock(&acpi_device_del_lock);
 506                         break;
 507                 }
 508                 adev = list_first_entry(&acpi_device_del_list,
 509                                         struct acpi_device, del_list);
 510                 list_del(&adev->del_list);
 511
 512                 mutex_unlock(&acpi_device_del_lock);
 513
 514                 blocking_notifier_call_chain(&acpi_reconfig_chain,
 515                                              ACPI_RECONFIG_DEVICE_REMOVE, adev);
 516
 517                 acpi_device_del(adev);
 518                 /*
 519                  * Drop references to all power resources that might have been
 520                  * used by the device.
 521                  */
 522                 acpi_power_transition(adev, ACPI_STATE_D3_COLD);
 523                 acpi_dev_put(adev);
 524         }
 525 }
 526
 527 /**
 528  * acpi_scan_drop_device - Drop an ACPI device object.
 529  * @handle: Handle of an ACPI namespace node, not used.
 530  * @context: Address of the ACPI device object to drop.
 531  *
 532  * This is invoked by acpi_ns_delete_node() during the removal of the ACPI
 533  * namespace node the device object pointed to by @context is attached to.
 534  *
 535  * The unregistration is carried out asynchronously to avoid running
 536  * acpi_device_del() under the ACPICA's namespace mutex and the list is used to
 537  * ensure the correct ordering (the device objects must be unregistered in the
 538  * same order in which the corresponding namespace nodes are deleted).
 539  */
 540 static void acpi_scan_drop_device(acpi_handle handle, void *context)
 541 {
 542         static DECLARE_WORK(work, acpi_device_del_work_fn);
 543         struct acpi_device *adev = context;
 544
 545         mutex_lock(&acpi_device_del_lock);
 546
 547         /*
 548          * Use the ACPI hotplug workqueue which is ordered, so this work item
 549          * won't run after any hotplug work items submitted subsequently.  That
 550          * prevents attempts to register device objects identical to those being
 551          * deleted from happening concurrently (such attempts result from
 552          * hotplug events handled via the ACPI hotplug workqueue).  It also will
 553          * run after all of the work items submitted previously, which helps
 554          * those work items to ensure that they are not accessing stale device
 555          * objects.
 556          */
 557         if (list_empty(&acpi_device_del_list))
 558                 acpi_queue_hotplug_work(&work);
 559
 560         list_add_tail(&adev->del_list, &acpi_device_del_list);
 561         /* Make acpi_ns_validate_handle() return NULL for this handle. */
 562         adev->handle = INVALID_ACPI_HANDLE;
 563
 564         mutex_unlock(&acpi_device_del_lock);
 565 }
 566
 567 static struct acpi_device *handle_to_device(acpi_handle handle,
 568                                             void (*callback)(void *))
 569 {
 570         struct acpi_device *adev = NULL;
 571         acpi_status status;
 572
 573         status = acpi_get_data_full(handle, acpi_scan_drop_device,
 574                                     (void **)&adev, callback);
 575         if (ACPI_FAILURE(status) || !adev) {
 576                 acpi_handle_debug(handle, "No context!\n");
 577                 return NULL;
 578         }
 579         return adev;
 580 }
 581
 582 /**
 583  * acpi_fetch_acpi_dev - Retrieve ACPI device object.
 584  * @handle: ACPI handle associated with the requested ACPI device object.
 585  *
 586  * Return a pointer to the ACPI device object associated with @handle, if
 587  * present, or NULL otherwise.
 588  */
 589 struct acpi_device *acpi_fetch_acpi_dev(acpi_handle handle)
 590 {
 591         return handle_to_device(handle, NULL);
 592 }
 593 EXPORT_SYMBOL_GPL(acpi_fetch_acpi_dev);
 594
 595 static void get_acpi_device(void *dev)
 596 {
 597         acpi_dev_get(dev);
 598 }
 599
 600 /**
 601  * acpi_get_acpi_dev - Retrieve ACPI device object and reference count it.
 602  * @handle: ACPI handle associated with the requested ACPI device object.
 603  *
 604  * Return a pointer to the ACPI device object associated with @handle and bump
 605  * up that object's reference counter (under the ACPI Namespace lock), if
 606  * present, or return NULL otherwise.
 607  *
 608  * The ACPI device object reference acquired by this function needs to be
 609  * dropped via acpi_dev_put().
 610  */
 611 struct acpi_device *acpi_get_acpi_dev(acpi_handle handle)
 612 {
 613         return handle_to_device(handle, get_acpi_device);
 614 }
 615 EXPORT_SYMBOL_GPL(acpi_get_acpi_dev);
 616
 617 static struct acpi_device_bus_id *acpi_device_bus_id_match(const char *dev_id)
 618 {
 619         struct acpi_device_bus_id *acpi_device_bus_id;
 620
 621         /* Find suitable bus_id and instance number in acpi_bus_id_list. */
 622         list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
 623                 if (!strcmp(acpi_device_bus_id->bus_id, dev_id))
 624                         return acpi_device_bus_id;
 625         }
 626         return NULL;
 627 }
 628
 629 static int acpi_device_set_name(struct acpi_device *device,
 630                                 struct acpi_device_bus_id *acpi_device_bus_id)
 631 {
 632         struct ida *instance_ida = &acpi_device_bus_id->instance_ida;
 633         int result;
 634
 635         result = ida_alloc(instance_ida, GFP_KERNEL);
 636         if (result < 0)
 637                 return result;
 638
 639         device->pnp.instance_no = result;
 640         dev_set_name(&device->dev, "%s:%02x", acpi_device_bus_id->bus_id, result);
 641         return 0;
 642 }
 643
 644 int acpi_tie_acpi_dev(struct acpi_device *adev)
 645 {
 646         acpi_handle handle = adev->handle;
 647         acpi_status status;
 648
 649         if (!handle)
 650                 return 0;
 651
 652         status = acpi_attach_data(handle, acpi_scan_drop_device, adev);
 653         if (ACPI_FAILURE(status)) {
 654                 acpi_handle_err(handle, "Unable to attach device data\n");
 655                 return -ENODEV;
 656         }
 657
 658         return 0;
 659 }
 660
 661 static void acpi_store_pld_crc(struct acpi_device *adev)
 662 {
 663         struct acpi_pld_info *pld;
 664         acpi_status status;
 665
 666         status = acpi_get_physical_device_location(adev->handle, &pld);
 667         if (ACPI_FAILURE(status))
 668                 return;
 669
 670         adev->pld_crc = crc32(~0, pld, sizeof(*pld));
 671         ACPI_FREE(pld);
 672 }
 673
 674 int acpi_device_add(struct acpi_device *device)
 675 {
 676         struct acpi_device_bus_id *acpi_device_bus_id;
 677         int result;
 678
 679         /*
 680          * Linkage
 681          * -------
 682          * Link this device to its parent and siblings.
 683          */
 684         INIT_LIST_HEAD(&device->wakeup_list);
 685         INIT_LIST_HEAD(&device->physical_node_list);
 686         INIT_LIST_HEAD(&device->del_list);
 687         mutex_init(&device->physical_node_lock);
 688
 689         mutex_lock(&acpi_device_lock);
 690
 691         acpi_device_bus_id = acpi_device_bus_id_match(acpi_device_hid(device));
 692         if (acpi_device_bus_id) {
 693                 result = acpi_device_set_name(device, acpi_device_bus_id);
 694                 if (result)
 695                         goto err_unlock;
 696         } else {
 697                 acpi_device_bus_id = kzalloc(sizeof(*acpi_device_bus_id),
 698                                              GFP_KERNEL);
 699                 if (!acpi_device_bus_id) {
 700                         result = -ENOMEM;
 701                         goto err_unlock;
 702                 }
 703                 acpi_device_bus_id->bus_id =
 704                         kstrdup_const(acpi_device_hid(device), GFP_KERNEL);
 705                 if (!acpi_device_bus_id->bus_id) {
 706                         kfree(acpi_device_bus_id);
 707                         result = -ENOMEM;
 708                         goto err_unlock;
 709                 }
 710
 711                 ida_init(&acpi_device_bus_id->instance_ida);
 712
 713                 result = acpi_device_set_name(device, acpi_device_bus_id);
 714                 if (result) {
 715                         kfree_const(acpi_device_bus_id->bus_id);
 716                         kfree(acpi_device_bus_id);
 717                         goto err_unlock;
 718                 }
 719
 720                 list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
 721         }
 722
 723         if (device->wakeup.flags.valid)
 724                 list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);
 725
 726         acpi_store_pld_crc(device);
 727
 728         mutex_unlock(&acpi_device_lock);
 729
 730         result = device_add(&device->dev);
 731         if (result) {
 732                 dev_err(&device->dev, "Error registering device\n");
 733                 goto err;
 734         }
 735
 736         result = acpi_device_setup_files(device);
 737         if (result)
 738                 pr_err("Error creating sysfs interface for device %s\n",
 739                        dev_name(&device->dev));
 740
 741         return 0;
 742
 743 err:
 744         mutex_lock(&acpi_device_lock);
 745
 746         list_del(&device->wakeup_list);
 747
 748 err_unlock:
 749         mutex_unlock(&acpi_device_lock);
 750
 751         acpi_detach_data(device->handle, acpi_scan_drop_device);
 752
 753         return result;
 754 }
 755
 756 /* --------------------------------------------------------------------------
 757                                  Device Enumeration
 758    -------------------------------------------------------------------------- */
 759 static bool acpi_info_matches_ids(struct acpi_device_info *info,
 760                                   const char * const ids[])
 761 {
 762         struct acpi_pnp_device_id_list *cid_list = NULL;
 763         int i, index;
 764
 765         if (!(info->valid & ACPI_VALID_HID))
 766                 return false;
 767
 768         index = match_string(ids, -1, info->hardware_id.string);
 769         if (index >= 0)
 770                 return true;
 771
 772         if (info->valid & ACPI_VALID_CID)
 773                 cid_list = &info->compatible_id_list;
 774
 775         if (!cid_list)
 776                 return false;
 777
 778         for (i = 0; i < cid_list->count; i++) {
 779                 index = match_string(ids, -1, cid_list->ids[i].string);
 780                 if (index >= 0)
 781                         return true;
 782         }
 783
 784         return false;
 785 }
 786
 787 /* List of HIDs for which we ignore matching ACPI devices, when checking _DEP lists. */
 788 static const char * const acpi_ignore_dep_ids[] = {
 789         "PNP0D80", /* Windows-compatible System Power Management Controller */
 790         "INT33BD", /* Intel Baytrail Mailbox Device */
 791         "LATT2021", /* Lattice FW Update Client Driver */
 792         NULL
 793 };
 794
 795 /* List of HIDs for which we honor deps of matching ACPI devs, when checking _DEP lists. */
 796 static const char * const acpi_honor_dep_ids[] = {
 797         "INT3472", /* Camera sensor PMIC / clk and regulator info */
 798         NULL
 799 };
 800
 801 static struct acpi_device *acpi_find_parent_acpi_dev(acpi_handle handle)
 802 {
 803         struct acpi_device *adev;
 804
 805         /*
 806          * Fixed hardware devices do not appear in the namespace and do not
 807          * have handles, but we fabricate acpi_devices for them, so we have
 808          * to deal with them specially.
 809          */
 810         if (!handle)
 811                 return acpi_root;
 812
 813         do {
 814                 acpi_status status;
 815
 816                 status = acpi_get_parent(handle, &handle);
 817                 if (ACPI_FAILURE(status)) {
 818                         if (status != AE_NULL_ENTRY)
 819                                 return acpi_root;
 820
 821                         return NULL;
 822                 }
 823                 adev = acpi_fetch_acpi_dev(handle);
 824         } while (!adev);
 825         return adev;
 826 }
 827
 828 acpi_status
 829 acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
 830 {
 831         acpi_status status;
 832         acpi_handle tmp;
 833         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
 834         union acpi_object *obj;
 835
 836         status = acpi_get_handle(handle, "_EJD", &tmp);
 837         if (ACPI_FAILURE(status))
 838                 return status;
 839
 840         status = acpi_evaluate_object(handle, "_EJD", NULL, &buffer);
 841         if (ACPI_SUCCESS(status)) {
 842                 obj = buffer.pointer;
 843                 status = acpi_get_handle(ACPI_ROOT_OBJECT, obj->string.pointer,
 844                                          ejd);
 845                 kfree(buffer.pointer);
 846         }
 847         return status;
 848 }
 849 EXPORT_SYMBOL_GPL(acpi_bus_get_ejd);
 850
 851 static int acpi_bus_extract_wakeup_device_power_package(struct acpi_device *dev)
 852 {
 853         acpi_handle handle = dev->handle;
 854         struct acpi_device_wakeup *wakeup = &dev->wakeup;
 855         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 856         union acpi_object *package = NULL;
 857         union acpi_object *element = NULL;
 858         acpi_status status;
 859         int err = -ENODATA;
 860
 861         INIT_LIST_HEAD(&wakeup->resources);
 862
 863         /* _PRW */
 864         status = acpi_evaluate_object(handle, "_PRW", NULL, &buffer);
 865         if (ACPI_FAILURE(status)) {
 866                 acpi_handle_info(handle, "_PRW evaluation failed: %s\n",
 867                                  acpi_format_exception(status));
 868                 return err;
 869         }
 870
 871         package = (union acpi_object *)buffer.pointer;
 872
 873         if (!package || package->package.count < 2)
 874                 goto out;
 875
 876         element = &(package->package.elements[0]);
 877         if (!element)
 878                 goto out;
 879
 880         if (element->type == ACPI_TYPE_PACKAGE) {
 881                 if ((element->package.count < 2) ||
 882                     (element->package.elements[0].type !=
 883                      ACPI_TYPE_LOCAL_REFERENCE)
 884                     || (element->package.elements[1].type != ACPI_TYPE_INTEGER))
 885                         goto out;
 886
 887                 wakeup->gpe_device =
 888                     element->package.elements[0].reference.handle;
 889                 wakeup->gpe_number =
 890                     (u32) element->package.elements[1].integer.value;
 891         } else if (element->type == ACPI_TYPE_INTEGER) {
 892                 wakeup->gpe_device = NULL;
 893                 wakeup->gpe_number = element->integer.value;
 894         } else {
 895                 goto out;
 896         }
 897
 898         element = &(package->package.elements[1]);
 899         if (element->type != ACPI_TYPE_INTEGER)
 900                 goto out;
 901
 902         wakeup->sleep_state = element->integer.value;
 903
 904         err = acpi_extract_power_resources(package, 2, &wakeup->resources);
 905         if (err)
 906                 goto out;
 907
 908         if (!list_empty(&wakeup->resources)) {
 909                 int sleep_state;
 910
 911                 err = acpi_power_wakeup_list_init(&wakeup->resources,
 912                                                   &sleep_state);
 913                 if (err) {
 914                         acpi_handle_warn(handle, "Retrieving current states "
 915                                          "of wakeup power resources failed\n");
 916                         acpi_power_resources_list_free(&wakeup->resources);
 917                         goto out;
 918                 }
 919                 if (sleep_state < wakeup->sleep_state) {
 920                         acpi_handle_warn(handle, "Overriding _PRW sleep state "
 921                                          "(S%d) by S%d from power resources\n",
 922                                          (int)wakeup->sleep_state, sleep_state);
 923                         wakeup->sleep_state = sleep_state;
 924                 }
 925         }
 926
 927  out:
 928         kfree(buffer.pointer);
 929         return err;
 930 }
 931
 932 /* Do not use a button for S5 wakeup */
 933 #define ACPI_AVOID_WAKE_FROM_S5         BIT(0)
 934
 935 static bool acpi_wakeup_gpe_init(struct acpi_device *device)
 936 {
 937         static const struct acpi_device_id button_device_ids[] = {
 938                 {"PNP0C0C", 0},                         /* Power button */
 939                 {"PNP0C0D", ACPI_AVOID_WAKE_FROM_S5},   /* Lid */
 940                 {"PNP0C0E", ACPI_AVOID_WAKE_FROM_S5},   /* Sleep button */
 941                 {"", 0},
 942         };
 943         struct acpi_device_wakeup *wakeup = &device->wakeup;
 944         const struct acpi_device_id *match;
 945         acpi_status status;
 946
 947         wakeup->flags.notifier_present = 0;
 948
 949         /* Power button, Lid switch always enable wakeup */
 950         match = acpi_match_acpi_device(button_device_ids, device);
 951         if (match) {
 952                 if ((match->driver_data & ACPI_AVOID_WAKE_FROM_S5) &&
 953                     wakeup->sleep_state == ACPI_STATE_S5)
 954                         wakeup->sleep_state = ACPI_STATE_S4;
 955                 acpi_mark_gpe_for_wake(wakeup->gpe_device, wakeup->gpe_number);
 956                 device_set_wakeup_capable(&device->dev, true);
 957                 return true;
 958         }
 959
 960         status = acpi_setup_gpe_for_wake(device->handle, wakeup->gpe_device,
 961                                          wakeup->gpe_number);
 962         return ACPI_SUCCESS(status);
 963 }
 964
 965 static void acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
 966 {
 967         int err;
 968
 969         /* Presence of _PRW indicates wake capable */
 970         if (!acpi_has_method(device->handle, "_PRW"))
 971                 return;
 972
 973         err = acpi_bus_extract_wakeup_device_power_package(device);
 974         if (err) {
 975                 dev_err(&device->dev, "Unable to extract wakeup power resources");
 976                 return;
 977         }
 978
 979         device->wakeup.flags.valid = acpi_wakeup_gpe_init(device);
 980         device->wakeup.prepare_count = 0;
 981         /*
 982          * Call _PSW/_DSW object to disable its ability to wake the sleeping
 983          * system for the ACPI device with the _PRW object.
 984          * The _PSW object is deprecated in ACPI 3.0 and is replaced by _DSW.
 985          * So it is necessary to call _DSW object first. Only when it is not
 986          * present will the _PSW object used.
 987          */
 988         err = acpi_device_sleep_wake(device, 0, 0, 0);
 989         if (err)
 990                 pr_debug("error in _DSW or _PSW evaluation\n");
 991 }
 992
 993 static void acpi_bus_init_power_state(struct acpi_device *device, int state)
 994 {
 995         struct acpi_device_power_state *ps = &device->power.states[state];
 996         char pathname[5] = { '_', 'P', 'R', '0' + state, '\0' };
 997         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 998         acpi_status status;
 999
1000         INIT_LIST_HEAD(&ps->resources);
1001
1002         /* Evaluate "_PRx" to get referenced power resources */
1003         status = acpi_evaluate_object(device->handle, pathname, NULL, &buffer);
1004         if (ACPI_SUCCESS(status)) {
1005                 union acpi_object *package = buffer.pointer;
1006
1007                 if (buffer.length && package
1008                     && package->type == ACPI_TYPE_PACKAGE
1009                     && package->package.count)
1010                         acpi_extract_power_resources(package, 0, &ps->resources);
1011
1012                 ACPI_FREE(buffer.pointer);
1013         }
1014
1015         /* Evaluate "_PSx" to see if we can do explicit sets */
1016         pathname[2] = 'S';
1017         if (acpi_has_method(device->handle, pathname))
1018                 ps->flags.explicit_set = 1;
1019
1020         /* State is valid if there are means to put the device into it. */
1021         if (!list_empty(&ps->resources) || ps->flags.explicit_set)
1022                 ps->flags.valid = 1;
1023
1024         ps->power = -1;         /* Unknown - driver assigned */
1025         ps->latency = -1;       /* Unknown - driver assigned */
1026 }
1027
1028 static void acpi_bus_get_power_flags(struct acpi_device *device)
1029 {
1030         unsigned long long dsc = ACPI_STATE_D0;
1031         u32 i;
1032
1033         /* Presence of _PS0|_PR0 indicates 'power manageable' */
1034         if (!acpi_has_method(device->handle, "_PS0") &&
1035             !acpi_has_method(device->handle, "_PR0"))
1036                 return;
1037
1038         device->flags.power_manageable = 1;
1039
1040         /*
1041          * Power Management Flags
1042          */
1043         if (acpi_has_method(device->handle, "_PSC"))
1044                 device->power.flags.explicit_get = 1;
1045
1046         if (acpi_has_method(device->handle, "_IRC"))
1047                 device->power.flags.inrush_current = 1;
1048
1049         if (acpi_has_method(device->handle, "_DSW"))
1050                 device->power.flags.dsw_present = 1;
1051
1052         acpi_evaluate_integer(device->handle, "_DSC", NULL, &dsc);
1053         device->power.state_for_enumeration = dsc;
1054
1055         /*
1056          * Enumerate supported power management states
1057          */
1058         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++)
1059                 acpi_bus_init_power_state(device, i);
1060
1061         INIT_LIST_HEAD(&device->power.states[ACPI_STATE_D3_COLD].resources);
1062
1063         /* Set the defaults for D0 and D3hot (always supported). */
1064         device->power.states[ACPI_STATE_D0].flags.valid = 1;
1065         device->power.states[ACPI_STATE_D0].power = 100;
1066         device->power.states[ACPI_STATE_D3_HOT].flags.valid = 1;
1067
1068         /*
1069          * Use power resources only if the D0 list of them is populated, because
1070          * some platforms may provide _PR3 only to indicate D3cold support and
1071          * in those cases the power resources list returned by it may be bogus.
1072          */
1073         if (!list_empty(&device->power.states[ACPI_STATE_D0].resources)) {
1074                 device->power.flags.power_resources = 1;
1075                 /*
1076                  * D3cold is supported if the D3hot list of power resources is
1077                  * not empty.
1078                  */
1079                 if (!list_empty(&device->power.states[ACPI_STATE_D3_HOT].resources))
1080                         device->power.states[ACPI_STATE_D3_COLD].flags.valid = 1;
1081         }
1082
1083         if (acpi_bus_init_power(device))
1084                 device->flags.power_manageable = 0;
1085 }
1086
1087 static void acpi_bus_get_flags(struct acpi_device *device)
1088 {
1089         /* Presence of _STA indicates 'dynamic_status' */
1090         if (acpi_has_method(device->handle, "_STA"))
1091                 device->flags.dynamic_status = 1;
1092
1093         /* Presence of _RMV indicates 'removable' */
1094         if (acpi_has_method(device->handle, "_RMV"))
1095                 device->flags.removable = 1;
1096
1097         /* Presence of _EJD|_EJ0 indicates 'ejectable' */
1098         if (acpi_has_method(device->handle, "_EJD") ||
1099             acpi_has_method(device->handle, "_EJ0"))
1100                 device->flags.ejectable = 1;
1101 }
1102
1103 static void acpi_device_get_busid(struct acpi_device *device)
1104 {
1105         char bus_id[5] = { '?', 0 };
1106         struct acpi_buffer buffer = { sizeof(bus_id), bus_id };
1107         int i = 0;
1108
1109         /*
1110          * Bus ID
1111          * ------
1112          * The device's Bus ID is simply the object name.
1113          * TBD: Shouldn't this value be unique (within the ACPI namespace)?
1114          */
1115         if (!acpi_dev_parent(device)) {
1116                 strcpy(device->pnp.bus_id, "ACPI");
1117                 return;
1118         }
1119
1120         switch (device->device_type) {
1121         case ACPI_BUS_TYPE_POWER_BUTTON:
1122                 strcpy(device->pnp.bus_id, "PWRF");
1123                 break;
1124         case ACPI_BUS_TYPE_SLEEP_BUTTON:
1125                 strcpy(device->pnp.bus_id, "SLPF");
1126                 break;
1127         case ACPI_BUS_TYPE_ECDT_EC:
1128                 strcpy(device->pnp.bus_id, "ECDT");
1129                 break;
1130         default:
1131                 acpi_get_name(device->handle, ACPI_SINGLE_NAME, &buffer);
1132                 /* Clean up trailing underscores (if any) */
1133                 for (i = 3; i > 1; i--) {
1134                         if (bus_id[i] == '_')
1135                                 bus_id[i] = '\0';
1136                         else
1137                                 break;
1138                 }
1139                 strcpy(device->pnp.bus_id, bus_id);
1140                 break;
1141         }
1142 }
1143
1144 /*
1145  * acpi_ata_match - see if an acpi object is an ATA device
1146  *
1147  * If an acpi object has one of the ACPI ATA methods defined,
1148  * then we can safely call it an ATA device.
1149  */
1150 bool acpi_ata_match(acpi_handle handle)
1151 {
1152         return acpi_has_method(handle, "_GTF") ||
1153                acpi_has_method(handle, "_GTM") ||
1154                acpi_has_method(handle, "_STM") ||
1155                acpi_has_method(handle, "_SDD");
1156 }
1157
1158 /*
1159  * acpi_bay_match - see if an acpi object is an ejectable driver bay
1160  *
1161  * If an acpi object is ejectable and has one of the ACPI ATA methods defined,
1162  * then we can safely call it an ejectable drive bay
1163  */
1164 bool acpi_bay_match(acpi_handle handle)
1165 {
1166         acpi_handle phandle;
1167
1168         if (!acpi_has_method(handle, "_EJ0"))
1169                 return false;
1170         if (acpi_ata_match(handle))
1171                 return true;
1172         if (ACPI_FAILURE(acpi_get_parent(handle, &phandle)))
1173                 return false;
1174
1175         return acpi_ata_match(phandle);
1176 }
1177
1178 bool acpi_device_is_battery(struct acpi_device *adev)
1179 {
1180         struct acpi_hardware_id *hwid;
1181
1182         list_for_each_entry(hwid, &adev->pnp.ids, list)
1183                 if (!strcmp("PNP0C0A", hwid->id))
1184                         return true;
1185
1186         return false;
1187 }
1188
1189 static bool is_ejectable_bay(struct acpi_device *adev)
1190 {
1191         acpi_handle handle = adev->handle;
1192
1193         if (acpi_has_method(handle, "_EJ0") && acpi_device_is_battery(adev))
1194                 return true;
1195
1196         return acpi_bay_match(handle);
1197 }
1198
1199 /*
1200  * acpi_dock_match - see if an acpi object has a _DCK method
1201  */
1202 bool acpi_dock_match(acpi_handle handle)
1203 {
1204         return acpi_has_method(handle, "_DCK");
1205 }
1206
1207 static acpi_status
1208 acpi_backlight_cap_match(acpi_handle handle, u32 level, void *context,
1209                           void **return_value)
1210 {
1211         long *cap = context;
1212
1213         if (acpi_has_method(handle, "_BCM") &&
1214             acpi_has_method(handle, "_BCL")) {
1215                 acpi_handle_debug(handle, "Found generic backlight support\n");
1216                 *cap |= ACPI_VIDEO_BACKLIGHT;
1217                 /* We have backlight support, no need to scan further */
1218                 return AE_CTRL_TERMINATE;
1219         }
1220         return 0;
1221 }
1222
1223 /* Returns true if the ACPI object is a video device which can be
1224  * handled by video.ko.
1225  * The device will get a Linux specific CID added in scan.c to
1226  * identify the device as an ACPI graphics device
1227  * Be aware that the graphics device may not be physically present
1228  * Use acpi_video_get_capabilities() to detect general ACPI video
1229  * capabilities of present cards
1230  */
1231 long acpi_is_video_device(acpi_handle handle)
1232 {
1233         long video_caps = 0;
1234
1235         /* Is this device able to support video switching ? */
1236         if (acpi_has_method(handle, "_DOD") || acpi_has_method(handle, "_DOS"))
1237                 video_caps |= ACPI_VIDEO_OUTPUT_SWITCHING;
1238
1239         /* Is this device able to retrieve a video ROM ? */
1240         if (acpi_has_method(handle, "_ROM"))
1241                 video_caps |= ACPI_VIDEO_ROM_AVAILABLE;
1242
1243         /* Is this device able to configure which video head to be POSTed ? */
1244         if (acpi_has_method(handle, "_VPO") &&
1245             acpi_has_method(handle, "_GPD") &&
1246             acpi_has_method(handle, "_SPD"))
1247                 video_caps |= ACPI_VIDEO_DEVICE_POSTING;
1248
1249         /* Only check for backlight functionality if one of the above hit. */
1250         if (video_caps)
1251                 acpi_walk_namespace(ACPI_TYPE_DEVICE, handle,
1252                                     ACPI_UINT32_MAX, acpi_backlight_cap_match, NULL,
1253                                     &video_caps, NULL);
1254
1255         return video_caps;
1256 }
1257 EXPORT_SYMBOL(acpi_is_video_device);
1258
1259 const char *acpi_device_hid(struct acpi_device *device)
1260 {
1261         struct acpi_hardware_id *hid;
1262
1263         if (list_empty(&device->pnp.ids))
1264                 return dummy_hid;
1265
1266         hid = list_first_entry(&device->pnp.ids, struct acpi_hardware_id, list);
1267         return hid->id;
1268 }
1269 EXPORT_SYMBOL(acpi_device_hid);
1270
1271 static void acpi_add_id(struct acpi_device_pnp *pnp, const char *dev_id)
1272 {
1273         struct acpi_hardware_id *id;
1274
1275         id = kmalloc(sizeof(*id), GFP_KERNEL);
1276         if (!id)
1277                 return;
1278
1279         id->id = kstrdup_const(dev_id, GFP_KERNEL);
1280         if (!id->id) {
1281                 kfree(id);
1282                 return;
1283         }
1284
1285         list_add_tail(&id->list, &pnp->ids);
1286         pnp->type.hardware_id = 1;
1287 }
1288
1289 /*
1290  * Old IBM workstations have a DSDT bug wherein the SMBus object
1291  * lacks the SMBUS01 HID and the methods do not have the necessary "_"
1292  * prefix.  Work around this.
1293  */
1294 static bool acpi_ibm_smbus_match(acpi_handle handle)
1295 {
1296         char node_name[ACPI_PATH_SEGMENT_LENGTH];
1297         struct acpi_buffer path = { sizeof(node_name), node_name };
1298
1299         if (!dmi_name_in_vendors("IBM"))
1300                 return false;
1301
1302         /* Look for SMBS object */
1303         if (ACPI_FAILURE(acpi_get_name(handle, ACPI_SINGLE_NAME, &path)) ||
1304             strcmp("SMBS", path.pointer))
1305                 return false;
1306
1307         /* Does it have the necessary (but misnamed) methods? */
1308         if (acpi_has_method(handle, "SBI") &&
1309             acpi_has_method(handle, "SBR") &&
1310             acpi_has_method(handle, "SBW"))
1311                 return true;
1312
1313         return false;
1314 }
1315
1316 static bool acpi_object_is_system_bus(acpi_handle handle)
1317 {
1318         acpi_handle tmp;
1319
1320         if (ACPI_SUCCESS(acpi_get_handle(NULL, "\\_SB", &tmp)) &&
1321             tmp == handle)
1322                 return true;
1323         if (ACPI_SUCCESS(acpi_get_handle(NULL, "\\_TZ", &tmp)) &&
1324             tmp == handle)
1325                 return true;
1326
1327         return false;
1328 }
1329
1330 static void acpi_set_pnp_ids(acpi_handle handle, struct acpi_device_pnp *pnp,
1331                              int device_type)
1332 {
1333         struct acpi_device_info *info = NULL;
1334         struct acpi_pnp_device_id_list *cid_list;
1335         int i;
1336
1337         switch (device_type) {
1338         case ACPI_BUS_TYPE_DEVICE:
1339                 if (handle == ACPI_ROOT_OBJECT) {
1340                         acpi_add_id(pnp, ACPI_SYSTEM_HID);
1341                         break;
1342                 }
1343
1344                 acpi_get_object_info(handle, &info);
1345                 if (!info) {
1346                         pr_err("%s: Error reading device info\n", __func__);
1347                         return;
1348                 }
1349
1350                 if (info->valid & ACPI_VALID_HID) {
1351                         acpi_add_id(pnp, info->hardware_id.string);
1352                         pnp->type.platform_id = 1;
1353                 }
1354                 if (info->valid & ACPI_VALID_CID) {
1355                         cid_list = &info->compatible_id_list;
1356                         for (i = 0; i < cid_list->count; i++)
1357                                 acpi_add_id(pnp, cid_list->ids[i].string);
1358                 }
1359                 if (info->valid & ACPI_VALID_ADR) {
1360                         pnp->bus_address = info->address;
1361                         pnp->type.bus_address = 1;
1362                 }
1363                 if (info->valid & ACPI_VALID_UID)
1364                         pnp->unique_id = kstrdup(info->unique_id.string,
1365                                                         GFP_KERNEL);
1366                 if (info->valid & ACPI_VALID_CLS)
1367                         acpi_add_id(pnp, info->class_code.string);
1368
1369                 kfree(info);
1370
1371                 /*
1372                  * Some devices don't reliably have _HIDs & _CIDs, so add
1373                  * synthetic HIDs to make sure drivers can find them.
1374                  */
1375                 if (acpi_is_video_device(handle)) {
1376                         acpi_add_id(pnp, ACPI_VIDEO_HID);
1377                         pnp->type.backlight = 1;
1378                         break;
1379                 }
1380                 if (acpi_bay_match(handle))
1381                         acpi_add_id(pnp, ACPI_BAY_HID);
1382                 else if (acpi_dock_match(handle))
1383                         acpi_add_id(pnp, ACPI_DOCK_HID);
1384                 else if (acpi_ibm_smbus_match(handle))
1385                         acpi_add_id(pnp, ACPI_SMBUS_IBM_HID);
1386                 else if (list_empty(&pnp->ids) &&
1387                          acpi_object_is_system_bus(handle)) {
1388                         /* \_SB, \_TZ, LNXSYBUS */
1389                         acpi_add_id(pnp, ACPI_BUS_HID);
1390                         strcpy(pnp->device_name, ACPI_BUS_DEVICE_NAME);
1391                         strcpy(pnp->device_class, ACPI_BUS_CLASS);
1392                 }
1393
1394                 break;
1395         case ACPI_BUS_TYPE_POWER:
1396                 acpi_add_id(pnp, ACPI_POWER_HID);
1397                 break;
1398         case ACPI_BUS_TYPE_PROCESSOR:
1399                 acpi_add_id(pnp, ACPI_PROCESSOR_OBJECT_HID);
1400                 break;
1401         case ACPI_BUS_TYPE_THERMAL:
1402                 acpi_add_id(pnp, ACPI_THERMAL_HID);
1403                 break;
1404         case ACPI_BUS_TYPE_POWER_BUTTON:
1405                 acpi_add_id(pnp, ACPI_BUTTON_HID_POWERF);
1406                 break;
1407         case ACPI_BUS_TYPE_SLEEP_BUTTON:
1408                 acpi_add_id(pnp, ACPI_BUTTON_HID_SLEEPF);
1409                 break;
1410         case ACPI_BUS_TYPE_ECDT_EC:
1411                 acpi_add_id(pnp, ACPI_ECDT_HID);
1412                 break;
1413         }
1414 }
1415
1416 void acpi_free_pnp_ids(struct acpi_device_pnp *pnp)
1417 {
1418         struct acpi_hardware_id *id, *tmp;
1419
1420         list_for_each_entry_safe(id, tmp, &pnp->ids, list) {
1421                 kfree_const(id->id);
1422                 kfree(id);
1423         }
1424         kfree(pnp->unique_id);
1425 }
1426
1427 /**
1428  * acpi_dma_supported - Check DMA support for the specified device.
1429  * @adev: The pointer to acpi device
1430  *
1431  * Return false if DMA is not supported. Otherwise, return true
1432  */
1433 bool acpi_dma_supported(const struct acpi_device *adev)
1434 {
1435         if (!adev)
1436                 return false;
1437
1438         if (adev->flags.cca_seen)
1439                 return true;
1440
1441         /*
1442         * Per ACPI 6.0 sec 6.2.17, assume devices can do cache-coherent
1443         * DMA on "Intel platforms".  Presumably that includes all x86 and
1444         * ia64, and other arches will set CONFIG_ACPI_CCA_REQUIRED=y.
1445         */
1446         if (!IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED))
1447                 return true;
1448
1449         return false;
1450 }
1451
1452 /**
1453  * acpi_get_dma_attr - Check the supported DMA attr for the specified device.
1454  * @adev: The pointer to acpi device
1455  *
1456  * Return enum dev_dma_attr.
1457  */
1458 enum dev_dma_attr acpi_get_dma_attr(struct acpi_device *adev)
1459 {
1460         if (!acpi_dma_supported(adev))
1461                 return DEV_DMA_NOT_SUPPORTED;
1462
1463         if (adev->flags.coherent_dma)
1464                 return DEV_DMA_COHERENT;
1465         else
1466                 return DEV_DMA_NON_COHERENT;
1467 }
1468
1469 /**
1470  * acpi_dma_get_range() - Get device DMA parameters.
1471  *
1472  * @dev: device to configure
1473  * @map: pointer to DMA ranges result
1474  *
1475  * Evaluate DMA regions and return pointer to DMA regions on
1476  * parsing success; it does not update the passed in values on failure.
1477  *
1478  * Return 0 on success, < 0 on failure.
1479  */
1480 int acpi_dma_get_range(struct device *dev, const struct bus_dma_region **map)
1481 {
1482         struct acpi_device *adev;
1483         LIST_HEAD(list);
1484         struct resource_entry *rentry;
1485         int ret;
1486         struct device *dma_dev = dev;
1487         struct bus_dma_region *r;
1488
1489         /*
1490          * Walk the device tree chasing an ACPI companion with a _DMA
1491          * object while we go. Stop if we find a device with an ACPI
1492          * companion containing a _DMA method.
1493          */
1494         do {
1495                 adev = ACPI_COMPANION(dma_dev);
1496                 if (adev && acpi_has_method(adev->handle, METHOD_NAME__DMA))
1497                         break;
1498
1499                 dma_dev = dma_dev->parent;
1500         } while (dma_dev);
1501
1502         if (!dma_dev)
1503                 return -ENODEV;
1504
1505         if (!acpi_has_method(adev->handle, METHOD_NAME__CRS)) {
1506                 acpi_handle_warn(adev->handle, "_DMA is valid only if _CRS is present\n");
1507                 return -EINVAL;
1508         }
1509
1510         ret = acpi_dev_get_dma_resources(adev, &list);
1511         if (ret > 0) {
1512                 r = kcalloc(ret + 1, sizeof(*r), GFP_KERNEL);
1513                 if (!r) {
1514                         ret = -ENOMEM;
1515                         goto out;
1516                 }
1517
1518                 *map = r;
1519
1520                 list_for_each_entry(rentry, &list, node) {
1521                         if (rentry->res->start >= rentry->res->end) {
1522                                 kfree(*map);
1523                                 *map = NULL;
1524                                 ret = -EINVAL;
1525                                 dev_dbg(dma_dev, "Invalid DMA regions configuration\n");
1526                                 goto out;
1527                         }
1528
1529                         r->cpu_start = rentry->res->start;
1530                         r->dma_start = rentry->res->start - rentry->offset;
1531                         r->size = resource_size(rentry->res);
1532                         r->offset = rentry->offset;
1533                         r++;
1534                 }
1535         }
1536  out:
1537         acpi_dev_free_resource_list(&list);
1538
1539         return ret >= 0 ? 0 : ret;
1540 }
1541
1542 #ifdef CONFIG_IOMMU_API
1543 int acpi_iommu_fwspec_init(struct device *dev, u32 id,
1544                            struct fwnode_handle *fwnode,
1545                            const struct iommu_ops *ops)
1546 {
1547         int ret = iommu_fwspec_init(dev, fwnode, ops);
1548
1549         if (!ret)
1550                 ret = iommu_fwspec_add_ids(dev, &id, 1);
1551
1552         return ret;
1553 }
1554
1555 static inline const struct iommu_ops *acpi_iommu_fwspec_ops(struct device *dev)
1556 {
1557         struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
1558
1559         return fwspec ? fwspec->ops : NULL;
1560 }
1561
1562 static const struct iommu_ops *acpi_iommu_configure_id(struct device *dev,
1563                                                        const u32 *id_in)
1564 {
1565         int err;
1566         const struct iommu_ops *ops;
1567
1568         /*
1569          * If we already translated the fwspec there is nothing left to do,
1570          * return the iommu_ops.
1571          */
1572         ops = acpi_iommu_fwspec_ops(dev);
1573         if (ops)
1574                 return ops;
1575
1576         err = iort_iommu_configure_id(dev, id_in);
1577         if (err && err != -EPROBE_DEFER)
1578                 err = viot_iommu_configure(dev);
1579
1580         /*
1581          * If we have reason to believe the IOMMU driver missed the initial
1582          * iommu_probe_device() call for dev, replay it to get things in order.
1583          */
1584         if (!err && dev->bus && !device_iommu_mapped(dev))
1585                 err = iommu_probe_device(dev);
1586
1587         /* Ignore all other errors apart from EPROBE_DEFER */
1588         if (err == -EPROBE_DEFER) {
1589                 return ERR_PTR(err);
1590         } else if (err) {
1591                 dev_dbg(dev, "Adding to IOMMU failed: %d\n", err);
1592                 return NULL;
1593         }
1594         return acpi_iommu_fwspec_ops(dev);
1595 }
1596
1597 #else /* !CONFIG_IOMMU_API */
1598
1599 int acpi_iommu_fwspec_init(struct device *dev, u32 id,
1600                            struct fwnode_handle *fwnode,
1601                            const struct iommu_ops *ops)
1602 {
1603         return -ENODEV;
1604 }
1605
1606 static const struct iommu_ops *acpi_iommu_configure_id(struct device *dev,
1607                                                        const u32 *id_in)
1608 {
1609         return NULL;
1610 }
1611
1612 #endif /* !CONFIG_IOMMU_API */
1613
1614 /**
1615  * acpi_dma_configure_id - Set-up DMA configuration for the device.
1616  * @dev: The pointer to the device
1617  * @attr: device dma attributes
1618  * @input_id: input device id const value pointer
1619  */
1620 int acpi_dma_configure_id(struct device *dev, enum dev_dma_attr attr,
1621                           const u32 *input_id)
1622 {
1623         const struct iommu_ops *iommu;
1624
1625         if (attr == DEV_DMA_NOT_SUPPORTED) {
1626                 set_dma_ops(dev, &dma_dummy_ops);
1627                 return 0;
1628         }
1629
1630         acpi_arch_dma_setup(dev);
1631
1632         iommu = acpi_iommu_configure_id(dev, input_id);
1633         if (PTR_ERR(iommu) == -EPROBE_DEFER)
1634                 return -EPROBE_DEFER;
1635
1636         arch_setup_dma_ops(dev, 0, U64_MAX,
1637                                 iommu, attr == DEV_DMA_COHERENT);
1638
1639         return 0;
1640 }
1641 EXPORT_SYMBOL_GPL(acpi_dma_configure_id);
1642
1643 static void acpi_init_coherency(struct acpi_device *adev)
1644 {
1645         unsigned long long cca = 0;
1646         acpi_status status;
1647         struct acpi_device *parent = acpi_dev_parent(adev);
1648
1649         if (parent && parent->flags.cca_seen) {
1650                 /*
1651                  * From ACPI spec, OSPM will ignore _CCA if an ancestor
1652                  * already saw one.
1653                  */
1654                 adev->flags.cca_seen = 1;
1655                 cca = parent->flags.coherent_dma;
1656         } else {
1657                 status = acpi_evaluate_integer(adev->handle, "_CCA",
1658                                                NULL, &cca);
1659                 if (ACPI_SUCCESS(status))
1660                         adev->flags.cca_seen = 1;
1661                 else if (!IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED))
1662                         /*
1663                          * If architecture does not specify that _CCA is
1664                          * required for DMA-able devices (e.g. x86),
1665                          * we default to _CCA=1.
1666                          */
1667                         cca = 1;
1668                 else
1669                         acpi_handle_debug(adev->handle,
1670                                           "ACPI device is missing _CCA.\n");
1671         }
1672
1673         adev->flags.coherent_dma = cca;
1674 }
1675
1676 static int acpi_check_serial_bus_slave(struct acpi_resource *ares, void *data)
1677 {
1678         bool *is_serial_bus_slave_p = data;
1679
1680         if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
1681                 return 1;
1682
1683         *is_serial_bus_slave_p = true;
1684
1685          /* no need to do more checking */
1686         return -1;
1687 }
1688
1689 static bool acpi_is_indirect_io_slave(struct acpi_device *device)
1690 {
1691         struct acpi_device *parent = acpi_dev_parent(device);
1692         static const struct acpi_device_id indirect_io_hosts[] = {
1693                 {"HISI0191", 0},
1694                 {}
1695         };
1696
1697         return parent && !acpi_match_device_ids(parent, indirect_io_hosts);
1698 }
1699
1700 static bool acpi_device_enumeration_by_parent(struct acpi_device *device)
1701 {
1702         struct list_head resource_list;
1703         bool is_serial_bus_slave = false;
1704         static const struct acpi_device_id ignore_serial_bus_ids[] = {
1705         /*
1706          * These devices have multiple SerialBus resources and a client
1707          * device must be instantiated for each of them, each with
1708          * its own device id.
1709          * Normally we only instantiate one client device for the first
1710          * resource, using the ACPI HID as id. These special cases are handled
1711          * by the drivers/platform/x86/serial-multi-instantiate.c driver, which
1712          * knows which client device id to use for each resource.
1713          */
1714                 {"BSG1160", },
1715                 {"BSG2150", },
1716                 {"CSC3551", },
1717                 {"INT33FE", },
1718                 {"INT3515", },
1719                 /* Non-conforming _HID for Cirrus Logic already released */
1720                 {"CLSA0100", },
1721                 {"CLSA0101", },
1722         /*
1723          * Some ACPI devs contain SerialBus resources even though they are not
1724          * attached to a serial bus at all.
1725          */
1726                 {"MSHW0028", },
1727         /*
1728          * HIDs of device with an UartSerialBusV2 resource for which userspace
1729          * expects a regular tty cdev to be created (instead of the in kernel
1730          * serdev) and which have a kernel driver which expects a platform_dev
1731          * such as the rfkill-gpio driver.
1732          */
1733                 {"BCM4752", },
1734                 {"LNV4752", },
1735                 {}
1736         };
1737
1738         if (acpi_is_indirect_io_slave(device))
1739                 return true;
1740
1741         /* Macs use device properties in lieu of _CRS resources */
1742         if (x86_apple_machine &&
1743             (fwnode_property_present(&device->fwnode, "spiSclkPeriod") ||
1744              fwnode_property_present(&device->fwnode, "i2cAddress") ||
1745              fwnode_property_present(&device->fwnode, "baud")))
1746                 return true;
1747
1748         if (!acpi_match_device_ids(device, ignore_serial_bus_ids))
1749                 return false;
1750
1751         INIT_LIST_HEAD(&resource_list);
1752         acpi_dev_get_resources(device, &resource_list,
1753                                acpi_check_serial_bus_slave,
1754                                &is_serial_bus_slave);
1755         acpi_dev_free_resource_list(&resource_list);
1756
1757         return is_serial_bus_slave;
1758 }
1759
1760 void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,
1761                              int type, void (*release)(struct device *))
1762 {
1763         struct acpi_device *parent = acpi_find_parent_acpi_dev(handle);
1764
1765         INIT_LIST_HEAD(&device->pnp.ids);
1766         device->device_type = type;
1767         device->handle = handle;
1768         device->dev.parent = parent ? &parent->dev : NULL;
1769         device->dev.release = release;
1770         device->dev.bus = &acpi_bus_type;
1771         fwnode_init(&device->fwnode, &acpi_device_fwnode_ops);
1772         acpi_set_device_status(device, ACPI_STA_DEFAULT);
1773         acpi_device_get_busid(device);
1774         acpi_set_pnp_ids(handle, &device->pnp, type);
1775         acpi_init_properties(device);
1776         acpi_bus_get_flags(device);
1777         device->flags.match_driver = false;
1778         device->flags.initialized = true;
1779         device->flags.enumeration_by_parent =
1780                 acpi_device_enumeration_by_parent(device);
1781         acpi_device_clear_enumerated(device);
1782         device_initialize(&device->dev);
1783         dev_set_uevent_suppress(&device->dev, true);
1784         acpi_init_coherency(device);
1785 }
1786
1787 static void acpi_scan_dep_init(struct acpi_device *adev)
1788 {
1789         struct acpi_dep_data *dep;
1790
1791         list_for_each_entry(dep, &acpi_dep_list, node) {
1792                 if (dep->consumer == adev->handle) {
1793                         if (dep->honor_dep)
1794                                 adev->flags.honor_deps = 1;
1795
1796                         adev->dep_unmet++;
1797                 }
1798         }
1799 }
1800
1801 void acpi_device_add_finalize(struct acpi_device *device)
1802 {
1803         dev_set_uevent_suppress(&device->dev, false);
1804         kobject_uevent(&device->dev.kobj, KOBJ_ADD);
1805 }
1806
1807 static void acpi_scan_init_status(struct acpi_device *adev)
1808 {
1809         if (acpi_bus_get_status(adev))
1810                 acpi_set_device_status(adev, 0);
1811 }
1812
1813 static int acpi_add_single_object(struct acpi_device **child,
1814                                   acpi_handle handle, int type, bool dep_init)
1815 {
1816         struct acpi_device *device;
1817         bool release_dep_lock = false;
1818         int result;
1819
1820         device = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
1821         if (!device)
1822                 return -ENOMEM;
1823
1824         acpi_init_device_object(device, handle, type, acpi_device_release);
1825         /*
1826          * Getting the status is delayed till here so that we can call
1827          * acpi_bus_get_status() and use its quirk handling.  Note that
1828          * this must be done before the get power-/wakeup_dev-flags calls.
1829          */
1830         if (type == ACPI_BUS_TYPE_DEVICE || type == ACPI_BUS_TYPE_PROCESSOR) {
1831                 if (dep_init) {
1832                         mutex_lock(&acpi_dep_list_lock);
1833                         /*
1834                          * Hold the lock until the acpi_tie_acpi_dev() call
1835                          * below to prevent concurrent acpi_scan_clear_dep()
1836                          * from deleting a dependency list entry without
1837                          * updating dep_unmet for the device.
1838                          */
1839                         release_dep_lock = true;
1840                         acpi_scan_dep_init(device);
1841                 }
1842                 acpi_scan_init_status(device);
1843         }
1844
1845         acpi_bus_get_power_flags(device);
1846         acpi_bus_get_wakeup_device_flags(device);
1847
1848         result = acpi_tie_acpi_dev(device);
1849
1850         if (release_dep_lock)
1851                 mutex_unlock(&acpi_dep_list_lock);
1852
1853         if (!result)
1854                 result = acpi_device_add(device);
1855
1856         if (result) {
1857                 acpi_device_release(&device->dev);
1858                 return result;
1859         }
1860
1861         acpi_power_add_remove_device(device, true);
1862         acpi_device_add_finalize(device);
1863
1864         acpi_handle_debug(handle, "Added as %s, parent %s\n",
1865                           dev_name(&device->dev), device->dev.parent ?
1866                                 dev_name(device->dev.parent) : "(null)");
1867
1868         *child = device;
1869         return 0;
1870 }
1871
1872 static acpi_status acpi_get_resource_memory(struct acpi_resource *ares,
1873                                             void *context)
1874 {
1875         struct resource *res = context;
1876
1877         if (acpi_dev_resource_memory(ares, res))
1878                 return AE_CTRL_TERMINATE;
1879
1880         return AE_OK;
1881 }
1882
1883 static bool acpi_device_should_be_hidden(acpi_handle handle)
1884 {
1885         acpi_status status;
1886         struct resource res;
1887
1888         /* Check if it should ignore the UART device */
1889         if (!(spcr_uart_addr && acpi_has_method(handle, METHOD_NAME__CRS)))
1890                 return false;
1891
1892         /*
1893          * The UART device described in SPCR table is assumed to have only one
1894          * memory resource present. So we only look for the first one here.
1895          */
1896         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1897                                      acpi_get_resource_memory, &res);
1898         if (ACPI_FAILURE(status) || res.start != spcr_uart_addr)
1899                 return false;
1900
1901         acpi_handle_info(handle, "The UART device @%pa in SPCR table will be hidden\n",
1902                          &res.start);
1903
1904         return true;
1905 }
1906
1907 bool acpi_device_is_present(const struct acpi_device *adev)
1908 {
1909         return adev->status.present || adev->status.functional;
1910 }
1911
1912 static bool acpi_scan_handler_matching(struct acpi_scan_handler *handler,
1913                                        const char *idstr,
1914                                        const struct acpi_device_id **matchid)
1915 {
1916         const struct acpi_device_id *devid;
1917
1918         if (handler->match)
1919                 return handler->match(idstr, matchid);
1920
1921         for (devid = handler->ids; devid->id[0]; devid++)
1922                 if (!strcmp((char *)devid->id, idstr)) {
1923                         if (matchid)
1924                                 *matchid = devid;
1925
1926                         return true;
1927                 }
1928
1929         return false;
1930 }
1931
1932 static struct acpi_scan_handler *acpi_scan_match_handler(const char *idstr,
1933                                         const struct acpi_device_id **matchid)
1934 {
1935         struct acpi_scan_handler *handler;
1936
1937         list_for_each_entry(handler, &acpi_scan_handlers_list, list_node)
1938                 if (acpi_scan_handler_matching(handler, idstr, matchid))
1939                         return handler;
1940
1941         return NULL;
1942 }
1943
1944 void acpi_scan_hotplug_enabled(struct acpi_hotplug_profile *hotplug, bool val)
1945 {
1946         if (!!hotplug->enabled == !!val)
1947                 return;
1948
1949         mutex_lock(&acpi_scan_lock);
1950
1951         hotplug->enabled = val;
1952
1953         mutex_unlock(&acpi_scan_lock);
1954 }
1955
1956 static void acpi_scan_init_hotplug(struct acpi_device *adev)
1957 {
1958         struct acpi_hardware_id *hwid;
1959
1960         if (acpi_dock_match(adev->handle) || is_ejectable_bay(adev)) {
1961                 acpi_dock_add(adev);
1962                 return;
1963         }
1964         list_for_each_entry(hwid, &adev->pnp.ids, list) {
1965                 struct acpi_scan_handler *handler;
1966
1967                 handler = acpi_scan_match_handler(hwid->id, NULL);
1968                 if (handler) {
1969                         adev->flags.hotplug_notify = true;
1970                         break;
1971                 }
1972         }
1973 }
1974
1975 static u32 acpi_scan_check_dep(acpi_handle handle, bool check_dep)
1976 {
1977         struct acpi_handle_list dep_devices;
1978         acpi_status status;
1979         u32 count;
1980         int i;
1981
1982         /*
1983          * Check for _HID here to avoid deferring the enumeration of:
1984          * 1. PCI devices.
1985          * 2. ACPI nodes describing USB ports.
1986          * Still, checking for _HID catches more then just these cases ...
1987          */
1988         if (!check_dep || !acpi_has_method(handle, "_DEP") ||
1989             !acpi_has_method(handle, "_HID"))
1990                 return 0;
1991
1992         status = acpi_evaluate_reference(handle, "_DEP", NULL, &dep_devices);
1993         if (ACPI_FAILURE(status)) {
1994                 acpi_handle_debug(handle, "Failed to evaluate _DEP.\n");
1995                 return 0;
1996         }
1997
1998         for (count = 0, i = 0; i < dep_devices.count; i++) {
1999                 struct acpi_device_info *info;
2000                 struct acpi_dep_data *dep;
2001                 bool skip, honor_dep;
2002
2003                 status = acpi_get_object_info(dep_devices.handles[i], &info);
2004                 if (ACPI_FAILURE(status)) {
2005                         acpi_handle_debug(handle, "Error reading _DEP device info\n");
2006                         continue;
2007                 }
2008
2009                 skip = acpi_info_matches_ids(info, acpi_ignore_dep_ids);
2010                 honor_dep = acpi_info_matches_ids(info, acpi_honor_dep_ids);
2011                 kfree(info);
2012
2013                 if (skip)
2014                         continue;
2015
2016                 dep = kzalloc(sizeof(*dep), GFP_KERNEL);
2017                 if (!dep)
2018                         continue;
2019
2020                 count++;
2021
2022                 dep->supplier = dep_devices.handles[i];
2023                 dep->consumer = handle;
2024                 dep->honor_dep = honor_dep;
2025
2026                 mutex_lock(&acpi_dep_list_lock);
2027                 list_add_tail(&dep->node , &acpi_dep_list);
2028                 mutex_unlock(&acpi_dep_list_lock);
2029         }
2030
2031         return count;
2032 }
2033
2034 static acpi_status acpi_bus_check_add(acpi_handle handle, bool check_dep,
2035                                       struct acpi_device **adev_p)
2036 {
2037         struct acpi_device *device = acpi_fetch_acpi_dev(handle);
2038         acpi_object_type acpi_type;
2039         int type;
2040
2041         if (device)
2042                 goto out;
2043
2044         if (ACPI_FAILURE(acpi_get_type(handle, &acpi_type)))
2045                 return AE_OK;
2046
2047         switch (acpi_type) {
2048         case ACPI_TYPE_DEVICE:
2049                 if (acpi_device_should_be_hidden(handle))
2050                         return AE_OK;
2051
2052                 /* Bail out if there are dependencies. */
2053                 if (acpi_scan_check_dep(handle, check_dep) > 0)
2054                         return AE_CTRL_DEPTH;
2055
2056                 fallthrough;
2057         case ACPI_TYPE_ANY:     /* for ACPI_ROOT_OBJECT */
2058                 type = ACPI_BUS_TYPE_DEVICE;
2059                 break;
2060
2061         case ACPI_TYPE_PROCESSOR:
2062                 type = ACPI_BUS_TYPE_PROCESSOR;
2063                 break;
2064
2065         case ACPI_TYPE_THERMAL:
2066                 type = ACPI_BUS_TYPE_THERMAL;
2067                 break;
2068
2069         case ACPI_TYPE_POWER:
2070                 acpi_add_power_resource(handle);
2071                 fallthrough;
2072         default:
2073                 return AE_OK;
2074         }
2075
2076         /*
2077          * If check_dep is true at this point, the device has no dependencies,
2078          * or the creation of the device object would have been postponed above.
2079          */
2080         acpi_add_single_object(&device, handle, type, !check_dep);
2081         if (!device)
2082                 return AE_CTRL_DEPTH;
2083
2084         acpi_scan_init_hotplug(device);
2085
2086 out:
2087         if (!*adev_p)
2088                 *adev_p = device;
2089
2090         return AE_OK;
2091 }
2092
2093 static acpi_status acpi_bus_check_add_1(acpi_handle handle, u32 lvl_not_used,
2094                                         void *not_used, void **ret_p)
2095 {
2096         return acpi_bus_check_add(handle, true, (struct acpi_device **)ret_p);
2097 }
2098
2099 static acpi_status acpi_bus_check_add_2(acpi_handle handle, u32 lvl_not_used,
2100                                         void *not_used, void **ret_p)
2101 {
2102         return acpi_bus_check_add(handle, false, (struct acpi_device **)ret_p);
2103 }
2104
2105 static void acpi_default_enumeration(struct acpi_device *device)
2106 {
2107         /*
2108          * Do not enumerate devices with enumeration_by_parent flag set as
2109          * they will be enumerated by their respective parents.
2110          */
2111         if (!device->flags.enumeration_by_parent) {
2112                 acpi_create_platform_device(device, NULL);
2113                 acpi_device_set_enumerated(device);
2114         } else {
2115                 blocking_notifier_call_chain(&acpi_reconfig_chain,
2116                                              ACPI_RECONFIG_DEVICE_ADD, device);
2117         }
2118 }
2119
2120 static const struct acpi_device_id generic_device_ids[] = {
2121         {ACPI_DT_NAMESPACE_HID, },
2122         {"", },
2123 };
2124
2125 static int acpi_generic_device_attach(struct acpi_device *adev,
2126                                       const struct acpi_device_id *not_used)
2127 {
2128         /*
2129          * Since ACPI_DT_NAMESPACE_HID is the only ID handled here, the test
2130          * below can be unconditional.
2131          */
2132         if (adev->data.of_compatible)
2133                 acpi_default_enumeration(adev);
2134
2135         return 1;
2136 }
2137
2138 static struct acpi_scan_handler generic_device_handler = {
2139         .ids = generic_device_ids,
2140         .attach = acpi_generic_device_attach,
2141 };
2142
2143 static int acpi_scan_attach_handler(struct acpi_device *device)
2144 {
2145         struct acpi_hardware_id *hwid;
2146         int ret = 0;
2147
2148         list_for_each_entry(hwid, &device->pnp.ids, list) {
2149                 const struct acpi_device_id *devid;
2150                 struct acpi_scan_handler *handler;
2151
2152                 handler = acpi_scan_match_handler(hwid->id, &devid);
2153                 if (handler) {
2154                         if (!handler->attach) {
2155                                 device->pnp.type.platform_id = 0;
2156                                 continue;
2157                         }
2158                         device->handler = handler;
2159                         ret = handler->attach(device, devid);
2160                         if (ret > 0)
2161                                 break;
2162
2163                         device->handler = NULL;
2164                         if (ret < 0)
2165                                 break;
2166                 }
2167         }
2168
2169         return ret;
2170 }
2171
2172 static int acpi_bus_attach(struct acpi_device *device, void *first_pass)
2173 {
2174         bool skip = !first_pass && device->flags.visited;
2175         acpi_handle ejd;
2176         int ret;
2177
2178         if (skip)
2179                 goto ok;
2180
2181         if (ACPI_SUCCESS(acpi_bus_get_ejd(device->handle, &ejd)))
2182                 register_dock_dependent_device(device, ejd);
2183
2184         acpi_bus_get_status(device);
2185         /* Skip devices that are not ready for enumeration (e.g. not present) */
2186         if (!acpi_dev_ready_for_enumeration(device)) {
2187                 device->flags.initialized = false;
2188                 acpi_device_clear_enumerated(device);
2189                 device->flags.power_manageable = 0;
2190                 return 0;
2191         }
2192         if (device->handler)
2193                 goto ok;
2194
2195         if (!device->flags.initialized) {
2196                 device->flags.power_manageable =
2197                         device->power.states[ACPI_STATE_D0].flags.valid;
2198                 if (acpi_bus_init_power(device))
2199                         device->flags.power_manageable = 0;
2200
2201                 device->flags.initialized = true;
2202         } else if (device->flags.visited) {
2203                 goto ok;
2204         }
2205
2206         ret = acpi_scan_attach_handler(device);
2207         if (ret < 0)
2208                 return 0;
2209
2210         device->flags.match_driver = true;
2211         if (ret > 0 && !device->flags.enumeration_by_parent) {
2212                 acpi_device_set_enumerated(device);
2213                 goto ok;
2214         }
2215
2216         ret = device_attach(&device->dev);
2217         if (ret < 0)
2218                 return 0;
2219
2220         if (device->pnp.type.platform_id || device->flags.enumeration_by_parent)
2221                 acpi_default_enumeration(device);
2222         else
2223                 acpi_device_set_enumerated(device);
2224
2225 ok:
2226         acpi_dev_for_each_child(device, acpi_bus_attach, first_pass);
2227
2228         if (!skip && device->handler && device->handler->hotplug.notify_online)
2229                 device->handler->hotplug.notify_online(device);
2230
2231         return 0;
2232 }
2233
2234 static int acpi_dev_get_next_consumer_dev_cb(struct acpi_dep_data *dep, void *data)
2235 {
2236         struct acpi_device **adev_p = data;
2237         struct acpi_device *adev = *adev_p;
2238
2239         /*
2240          * If we're passed a 'previous' consumer device then we need to skip
2241          * any consumers until we meet the previous one, and then NULL @data
2242          * so the next one can be returned.
2243          */
2244         if (adev) {
2245                 if (dep->consumer == adev->handle)
2246                         *adev_p = NULL;
2247
2248                 return 0;
2249         }
2250
2251         adev = acpi_get_acpi_dev(dep->consumer);
2252         if (adev) {
2253                 *(struct acpi_device **)data = adev;
2254                 return 1;
2255         }
2256         /* Continue parsing if the device object is not present. */
2257         return 0;
2258 }
2259
2260 struct acpi_scan_clear_dep_work {
2261         struct work_struct work;
2262         struct acpi_device *adev;
2263 };
2264
2265 static void acpi_scan_clear_dep_fn(struct work_struct *work)
2266 {
2267         struct acpi_scan_clear_dep_work *cdw;
2268
2269         cdw = container_of(work, struct acpi_scan_clear_dep_work, work);
2270
2271         acpi_scan_lock_acquire();
2272         acpi_bus_attach(cdw->adev, (void *)true);
2273         acpi_scan_lock_release();
2274
2275         acpi_dev_put(cdw->adev);
2276         kfree(cdw);
2277 }
2278
2279 static bool acpi_scan_clear_dep_queue(struct acpi_device *adev)
2280 {
2281         struct acpi_scan_clear_dep_work *cdw;
2282
2283         if (adev->dep_unmet)
2284                 return false;
2285
2286         cdw = kmalloc(sizeof(*cdw), GFP_KERNEL);
2287         if (!cdw)
2288                 return false;
2289
2290         cdw->adev = adev;
2291         INIT_WORK(&cdw->work, acpi_scan_clear_dep_fn);
2292         /*
2293          * Since the work function may block on the lock until the entire
2294          * initial enumeration of devices is complete, put it into the unbound
2295          * workqueue.
2296          */
2297         queue_work(system_unbound_wq, &cdw->work);
2298
2299         return true;
2300 }
2301
2302 static void acpi_scan_delete_dep_data(struct acpi_dep_data *dep)
2303 {
2304         list_del(&dep->node);
2305         kfree(dep);
2306 }
2307
2308 static int acpi_scan_clear_dep(struct acpi_dep_data *dep, void *data)
2309 {
2310         struct acpi_device *adev = acpi_get_acpi_dev(dep->consumer);
2311
2312         if (adev) {
2313                 adev->dep_unmet--;
2314                 if (!acpi_scan_clear_dep_queue(adev))
2315                         acpi_dev_put(adev);
2316         }
2317
2318         if (dep->free_when_met)
2319                 acpi_scan_delete_dep_data(dep);
2320         else
2321                 dep->met = true;
2322
2323         return 0;
2324 }
2325
2326 /**
2327  * acpi_walk_dep_device_list - Apply a callback to every entry in acpi_dep_list
2328  * @handle:     The ACPI handle of the supplier device
2329  * @callback:   Pointer to the callback function to apply
2330  * @data:       Pointer to some data to pass to the callback
2331  *
2332  * The return value of the callback determines this function's behaviour. If 0
2333  * is returned we continue to iterate over acpi_dep_list. If a positive value
2334  * is returned then the loop is broken but this function returns 0. If a
2335  * negative value is returned by the callback then the loop is broken and that
2336  * value is returned as the final error.
2337  */
2338 static int acpi_walk_dep_device_list(acpi_handle handle,
2339                                 int (*callback)(struct acpi_dep_data *, void *),
2340                                 void *data)
2341 {
2342         struct acpi_dep_data *dep, *tmp;
2343         int ret = 0;
2344
2345         mutex_lock(&acpi_dep_list_lock);
2346         list_for_each_entry_safe(dep, tmp, &acpi_dep_list, node) {
2347                 if (dep->supplier == handle) {
2348                         ret = callback(dep, data);
2349                         if (ret)
2350                                 break;
2351                 }
2352         }
2353         mutex_unlock(&acpi_dep_list_lock);
2354
2355         return ret > 0 ? 0 : ret;
2356 }
2357
2358 /**
2359  * acpi_dev_clear_dependencies - Inform consumers that the device is now active
2360  * @supplier: Pointer to the supplier &struct acpi_device
2361  *
2362  * Clear dependencies on the given device.
2363  */
2364 void acpi_dev_clear_dependencies(struct acpi_device *supplier)
2365 {
2366         acpi_walk_dep_device_list(supplier->handle, acpi_scan_clear_dep, NULL);
2367 }
2368 EXPORT_SYMBOL_GPL(acpi_dev_clear_dependencies);
2369
2370 /**
2371  * acpi_dev_ready_for_enumeration - Check if the ACPI device is ready for enumeration
2372  * @device: Pointer to the &struct acpi_device to check
2373  *
2374  * Check if the device is present and has no unmet dependencies.
2375  *
2376  * Return true if the device is ready for enumeratino. Otherwise, return false.
2377  */
2378 bool acpi_dev_ready_for_enumeration(const struct acpi_device *device)
2379 {
2380         if (device->flags.honor_deps && device->dep_unmet)
2381                 return false;
2382
2383         return acpi_device_is_present(device);
2384 }
2385 EXPORT_SYMBOL_GPL(acpi_dev_ready_for_enumeration);
2386
2387 /**
2388  * acpi_dev_get_next_consumer_dev - Return the next adev dependent on @supplier
2389  * @supplier: Pointer to the dependee device
2390  * @start: Pointer to the current dependent device
2391  *
2392  * Returns the next &struct acpi_device which declares itself dependent on
2393  * @supplier via the _DEP buffer, parsed from the acpi_dep_list.
2394  *
2395  * If the returned adev is not passed as @start to this function, the caller is
2396  * responsible for putting the reference to adev when it is no longer needed.
2397  */
2398 struct acpi_device *acpi_dev_get_next_consumer_dev(struct acpi_device *supplier,
2399                                                    struct acpi_device *start)
2400 {
2401         struct acpi_device *adev = start;
2402
2403         acpi_walk_dep_device_list(supplier->handle,
2404                                   acpi_dev_get_next_consumer_dev_cb, &adev);
2405
2406         acpi_dev_put(start);
2407
2408         if (adev == start)
2409                 return NULL;
2410
2411         return adev;
2412 }
2413 EXPORT_SYMBOL_GPL(acpi_dev_get_next_consumer_dev);
2414
2415 static void acpi_scan_postponed_branch(acpi_handle handle)
2416 {
2417         struct acpi_device *adev = NULL;
2418
2419         if (ACPI_FAILURE(acpi_bus_check_add(handle, false, &adev)))
2420                 return;
2421
2422         acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
2423                             acpi_bus_check_add_2, NULL, NULL, (void **)&adev);
2424         acpi_bus_attach(adev, NULL);
2425 }
2426
2427 static void acpi_scan_postponed(void)
2428 {
2429         struct acpi_dep_data *dep, *tmp;
2430
2431         mutex_lock(&acpi_dep_list_lock);
2432
2433         list_for_each_entry_safe(dep, tmp, &acpi_dep_list, node) {
2434                 acpi_handle handle = dep->consumer;
2435
2436                 /*
2437                  * In case there are multiple acpi_dep_list entries with the
2438                  * same consumer, skip the current entry if the consumer device
2439                  * object corresponding to it is present already.
2440                  */
2441                 if (!acpi_fetch_acpi_dev(handle)) {
2442                         /*
2443                          * Even though the lock is released here, tmp is
2444                          * guaranteed to be valid, because none of the list
2445                          * entries following dep is marked as "free when met"
2446                          * and so they cannot be deleted.
2447                          */
2448                         mutex_unlock(&acpi_dep_list_lock);
2449
2450                         acpi_scan_postponed_branch(handle);
2451
2452                         mutex_lock(&acpi_dep_list_lock);
2453                 }
2454
2455                 if (dep->met)
2456                         acpi_scan_delete_dep_data(dep);
2457                 else
2458                         dep->free_when_met = true;
2459         }
2460
2461         mutex_unlock(&acpi_dep_list_lock);
2462 }
2463
2464 /**
2465  * acpi_bus_scan - Add ACPI device node objects in a given namespace scope.
2466  * @handle: Root of the namespace scope to scan.
2467  *
2468  * Scan a given ACPI tree (probably recently hot-plugged) and create and add
2469  * found devices.
2470  *
2471  * If no devices were found, -ENODEV is returned, but it does not mean that
2472  * there has been a real error.  There just have been no suitable ACPI objects
2473  * in the table trunk from which the kernel could create a device and add an
2474  * appropriate driver.
2475  *
2476  * Must be called under acpi_scan_lock.
2477  */
2478 int acpi_bus_scan(acpi_handle handle)
2479 {
2480         struct acpi_device *device = NULL;
2481
2482         /* Pass 1: Avoid enumerating devices with missing dependencies. */
2483
2484         if (ACPI_SUCCESS(acpi_bus_check_add(handle, true, &device)))
2485                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
2486                                     acpi_bus_check_add_1, NULL, NULL,
2487                                     (void **)&device);
2488
2489         if (!device)
2490                 return -ENODEV;
2491
2492         acpi_bus_attach(device, (void *)true);
2493
2494         /* Pass 2: Enumerate all of the remaining devices. */
2495
2496         acpi_scan_postponed();
2497
2498         return 0;
2499 }
2500 EXPORT_SYMBOL(acpi_bus_scan);
2501
2502 static int acpi_bus_trim_one(struct acpi_device *adev, void *not_used)
2503 {
2504         struct acpi_scan_handler *handler = adev->handler;
2505
2506         acpi_dev_for_each_child_reverse(adev, acpi_bus_trim_one, NULL);
2507
2508         adev->flags.match_driver = false;
2509         if (handler) {
2510                 if (handler->detach)
2511                         handler->detach(adev);
2512
2513                 adev->handler = NULL;
2514         } else {
2515                 device_release_driver(&adev->dev);
2516         }
2517         /*
2518          * Most likely, the device is going away, so put it into D3cold before
2519          * that.
2520          */
2521         acpi_device_set_power(adev, ACPI_STATE_D3_COLD);
2522         adev->flags.initialized = false;
2523         acpi_device_clear_enumerated(adev);
2524
2525         return 0;
2526 }
2527
2528 /**
2529  * acpi_bus_trim - Detach scan handlers and drivers from ACPI device objects.
2530  * @adev: Root of the ACPI namespace scope to walk.
2531  *
2532  * Must be called under acpi_scan_lock.
2533  */
2534 void acpi_bus_trim(struct acpi_device *adev)
2535 {
2536         acpi_bus_trim_one(adev, NULL);
2537 }
2538 EXPORT_SYMBOL_GPL(acpi_bus_trim);
2539
2540 int acpi_bus_register_early_device(int type)
2541 {
2542         struct acpi_device *device = NULL;
2543         int result;
2544
2545         result = acpi_add_single_object(&device, NULL, type, false);
2546         if (result)
2547                 return result;
2548
2549         device->flags.match_driver = true;
2550         return device_attach(&device->dev);
2551 }
2552 EXPORT_SYMBOL_GPL(acpi_bus_register_early_device);
2553
2554 static void acpi_bus_scan_fixed(void)
2555 {
2556         if (!(acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON)) {
2557                 struct acpi_device *adev = NULL;
2558
2559                 acpi_add_single_object(&adev, NULL, ACPI_BUS_TYPE_POWER_BUTTON,
2560                                        false);
2561                 if (adev) {
2562                         adev->flags.match_driver = true;
2563                         if (device_attach(&adev->dev) >= 0)
2564                                 device_init_wakeup(&adev->dev, true);
2565                         else
2566                                 dev_dbg(&adev->dev, "No driver\n");
2567                 }
2568         }
2569
2570         if (!(acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON)) {
2571                 struct acpi_device *adev = NULL;
2572
2573                 acpi_add_single_object(&adev, NULL, ACPI_BUS_TYPE_SLEEP_BUTTON,
2574                                        false);
2575                 if (adev) {
2576                         adev->flags.match_driver = true;
2577                         if (device_attach(&adev->dev) < 0)
2578                                 dev_dbg(&adev->dev, "No driver\n");
2579                 }
2580         }
2581 }
2582
2583 static void __init acpi_get_spcr_uart_addr(void)
2584 {
2585         acpi_status status;
2586         struct acpi_table_spcr *spcr_ptr;
2587
2588         status = acpi_get_table(ACPI_SIG_SPCR, 0,
2589                                 (struct acpi_table_header **)&spcr_ptr);
2590         if (ACPI_FAILURE(status)) {
2591                 pr_warn("STAO table present, but SPCR is missing\n");
2592                 return;
2593         }
2594
2595         spcr_uart_addr = spcr_ptr->serial_port.address;
2596         acpi_put_table((struct acpi_table_header *)spcr_ptr);
2597 }
2598
2599 static bool acpi_scan_initialized;
2600
2601 void __init acpi_scan_init(void)
2602 {
2603         acpi_status status;
2604         struct acpi_table_stao *stao_ptr;
2605
2606         acpi_pci_root_init();
2607         acpi_pci_link_init();
2608         acpi_processor_init();
2609         acpi_platform_init();
2610         acpi_lpss_init();
2611         acpi_apd_init();
2612         acpi_cmos_rtc_init();
2613         acpi_container_init();
2614         acpi_memory_hotplug_init();
2615         acpi_watchdog_init();
2616         acpi_pnp_init();
2617         acpi_int340x_thermal_init();
2618         acpi_amba_init();
2619         acpi_init_lpit();
2620
2621         acpi_scan_add_handler(&generic_device_handler);
2622
2623         /*
2624          * If there is STAO table, check whether it needs to ignore the UART
2625          * device in SPCR table.
2626          */
2627         status = acpi_get_table(ACPI_SIG_STAO, 0,
2628                                 (struct acpi_table_header **)&stao_ptr);
2629         if (ACPI_SUCCESS(status)) {
2630                 if (stao_ptr->header.length > sizeof(struct acpi_table_stao))
2631                         pr_info("STAO Name List not yet supported.\n");
2632
2633                 if (stao_ptr->ignore_uart)
2634                         acpi_get_spcr_uart_addr();
2635
2636                 acpi_put_table((struct acpi_table_header *)stao_ptr);
2637         }
2638
2639         acpi_gpe_apply_masked_gpes();
2640         acpi_update_all_gpes();
2641
2642         /*
2643          * Although we call __add_memory() that is documented to require the
2644          * device_hotplug_lock, it is not necessary here because this is an
2645          * early code when userspace or any other code path cannot trigger
2646          * hotplug/hotunplug operations.
2647          */
2648         mutex_lock(&acpi_scan_lock);
2649         /*
2650          * Enumerate devices in the ACPI namespace.
2651          */
2652         if (acpi_bus_scan(ACPI_ROOT_OBJECT))
2653                 goto unlock;
2654
2655         acpi_root = acpi_fetch_acpi_dev(ACPI_ROOT_OBJECT);
2656         if (!acpi_root)
2657                 goto unlock;
2658
2659         /* Fixed feature devices do not exist on HW-reduced platform */
2660         if (!acpi_gbl_reduced_hardware)
2661                 acpi_bus_scan_fixed();
2662
2663         acpi_turn_off_unused_power_resources();
2664
2665         acpi_scan_initialized = true;
2666
2667 unlock:
2668         mutex_unlock(&acpi_scan_lock);
2669 }
2670
2671 static struct acpi_probe_entry *ape;
2672 static int acpi_probe_count;
2673 static DEFINE_MUTEX(acpi_probe_mutex);
2674
2675 static int __init acpi_match_madt(union acpi_subtable_headers *header,
2676                                   const unsigned long end)
2677 {
2678         if (!ape->subtable_valid || ape->subtable_valid(&header->common, ape))
2679                 if (!ape->probe_subtbl(header, end))
2680                         acpi_probe_count++;
2681
2682         return 0;
2683 }
2684
2685 int __init __acpi_probe_device_table(struct acpi_probe_entry *ap_head, int nr)
2686 {
2687         int count = 0;
2688
2689         if (acpi_disabled)
2690                 return 0;
2691
2692         mutex_lock(&acpi_probe_mutex);
2693         for (ape = ap_head; nr; ape++, nr--) {
2694                 if (ACPI_COMPARE_NAMESEG(ACPI_SIG_MADT, ape->id)) {
2695                         acpi_probe_count = 0;
2696                         acpi_table_parse_madt(ape->type, acpi_match_madt, 0);
2697                         count += acpi_probe_count;
2698                 } else {
2699                         int res;
2700                         res = acpi_table_parse(ape->id, ape->probe_table);
2701                         if (!res)
2702                                 count++;
2703                 }
2704         }
2705         mutex_unlock(&acpi_probe_mutex);
2706
2707         return count;
2708 }
2709
2710 static void acpi_table_events_fn(struct work_struct *work)
2711 {
2712         acpi_scan_lock_acquire();
2713         acpi_bus_scan(ACPI_ROOT_OBJECT);
2714         acpi_scan_lock_release();
2715
2716         kfree(work);
2717 }
2718
2719 void acpi_scan_table_notify(void)
2720 {
2721         struct work_struct *work;
2722
2723         if (!acpi_scan_initialized)
2724                 return;
2725
2726         work = kmalloc(sizeof(*work), GFP_KERNEL);
2727         if (!work)
2728                 return;
2729
2730         INIT_WORK(work, acpi_table_events_fn);
2731         schedule_work(work);
2732 }
2733
2734 int acpi_reconfig_notifier_register(struct notifier_block *nb)
2735 {
2736         return blocking_notifier_chain_register(&acpi_reconfig_chain, nb);
2737 }
2738 EXPORT_SYMBOL(acpi_reconfig_notifier_register);
2739
2740 int acpi_reconfig_notifier_unregister(struct notifier_block *nb)
2741 {
2742         return blocking_notifier_chain_unregister(&acpi_reconfig_chain, nb);
2743 }
2744 EXPORT_SYMBOL(acpi_reconfig_notifier_unregister);