drivers/acpi/scan.c

   1 /*
   2  * scan.c - support for transforming the ACPI namespace into individual objects
   3  */
   4
   5 #include <linux/module.h>
   6 #include <linux/init.h>
   7 #include <linux/slab.h>
   8 #include <linux/kernel.h>
   9 #include <linux/acpi.h>
  10 #include <linux/signal.h>
  11 #include <linux/kthread.h>
  12 #include <linux/dmi.h>
  13 #include <linux/nls.h>
  14
  15 #include <acpi/acpi_drivers.h>
  16
  17 #include "internal.h"
  18
  19 #define _COMPONENT              ACPI_BUS_COMPONENT
  20 ACPI_MODULE_NAME("scan");
  21 #define STRUCT_TO_INT(s)        (*((int*)&s))
  22 extern struct acpi_device *acpi_root;
  23
  24 #define ACPI_BUS_CLASS                  "system_bus"
  25 #define ACPI_BUS_HID                    "LNXSYBUS"
  26 #define ACPI_BUS_DEVICE_NAME            "System Bus"
  27
  28 #define ACPI_IS_ROOT_DEVICE(device)    (!(device)->parent)
  29
  30 /*
  31  * If set, devices will be hot-removed even if they cannot be put offline
  32  * gracefully (from the kernel's standpoint).
  33  */
  34 bool acpi_force_hot_remove;
  35
  36 static const char *dummy_hid = "device";
  37
  38 static 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
  44 struct acpi_device_bus_id{
  45         char bus_id[15];
  46         unsigned int instance_no;
  47         struct list_head node;
  48 };
  49
  50 void acpi_scan_lock_acquire(void)
  51 {
  52         mutex_lock(&acpi_scan_lock);
  53 }
  54 EXPORT_SYMBOL_GPL(acpi_scan_lock_acquire);
  55
  56 void acpi_scan_lock_release(void)
  57 {
  58         mutex_unlock(&acpi_scan_lock);
  59 }
  60 EXPORT_SYMBOL_GPL(acpi_scan_lock_release);
  61
  62 int acpi_scan_add_handler(struct acpi_scan_handler *handler)
  63 {
  64         if (!handler || !handler->attach)
  65                 return -EINVAL;
  66
  67         list_add_tail(&handler->list_node, &acpi_scan_handlers_list);
  68         return 0;
  69 }
  70
  71 int acpi_scan_add_handler_with_hotplug(struct acpi_scan_handler *handler,
  72                                        const char *hotplug_profile_name)
  73 {
  74         int error;
  75
  76         error = acpi_scan_add_handler(handler);
  77         if (error)
  78                 return error;
  79
  80         acpi_sysfs_add_hotplug_profile(&handler->hotplug, hotplug_profile_name);
  81         return 0;
  82 }
  83
  84 /*
  85  * Creates hid/cid(s) string needed for modalias and uevent
  86  * e.g. on a device with hid:IBM0001 and cid:ACPI0001 you get:
  87  * char *modalias: "acpi:IBM0001:ACPI0001"
  88 */
  89 static int create_modalias(struct acpi_device *acpi_dev, char *modalias,
  90                            int size)
  91 {
  92         int len;
  93         int count;
  94         struct acpi_hardware_id *id;
  95
  96         if (list_empty(&acpi_dev->pnp.ids))
  97                 return 0;
  98
  99         len = snprintf(modalias, size, "acpi:");
 100         size -= len;
 101
 102         list_for_each_entry(id, &acpi_dev->pnp.ids, list) {
 103                 count = snprintf(&modalias[len], size, "%s:", id->id);
 104                 if (count < 0 || count >= size)
 105                         return -EINVAL;
 106                 len += count;
 107                 size -= count;
 108         }
 109
 110         modalias[len] = '\0';
 111         return len;
 112 }
 113
 114 static ssize_t
 115 acpi_device_modalias_show(struct device *dev, struct device_attribute *attr, char *buf) {
 116         struct acpi_device *acpi_dev = to_acpi_device(dev);
 117         int len;
 118
 119         /* Device has no HID and no CID or string is >1024 */
 120         len = create_modalias(acpi_dev, buf, 1024);
 121         if (len <= 0)
 122                 return 0;
 123         buf[len++] = '\n';
 124         return len;
 125 }
 126 static DEVICE_ATTR(modalias, 0444, acpi_device_modalias_show, NULL);
 127
 128 static acpi_status acpi_bus_offline_companions(acpi_handle handle, u32 lvl,
 129                                                void *data, void **ret_p)
 130 {
 131         struct acpi_device *device = NULL;
 132         struct acpi_device_physical_node *pn;
 133         bool second_pass = (bool)data;
 134         acpi_status status = AE_OK;
 135
 136         if (acpi_bus_get_device(handle, &device))
 137                 return AE_OK;
 138
 139         mutex_lock(&device->physical_node_lock);
 140
 141         list_for_each_entry(pn, &device->physical_node_list, node) {
 142                 int ret;
 143
 144                 if (second_pass) {
 145                         /* Skip devices offlined by the first pass. */
 146                         if (pn->put_online)
 147                                 continue;
 148                 } else {
 149                         pn->put_online = false;
 150                 }
 151                 ret = device_offline(pn->dev);
 152                 if (acpi_force_hot_remove)
 153                         continue;
 154
 155                 if (ret >= 0) {
 156                         pn->put_online = !ret;
 157                 } else {
 158                         *ret_p = pn->dev;
 159                         if (second_pass) {
 160                                 status = AE_ERROR;
 161                                 break;
 162                         }
 163                 }
 164         }
 165
 166         mutex_unlock(&device->physical_node_lock);
 167
 168         return status;
 169 }
 170
 171 static acpi_status acpi_bus_online_companions(acpi_handle handle, u32 lvl,
 172                                               void *data, void **ret_p)
 173 {
 174         struct acpi_device *device = NULL;
 175         struct acpi_device_physical_node *pn;
 176
 177         if (acpi_bus_get_device(handle, &device))
 178                 return AE_OK;
 179
 180         mutex_lock(&device->physical_node_lock);
 181
 182         list_for_each_entry(pn, &device->physical_node_list, node)
 183                 if (pn->put_online) {
 184                         device_online(pn->dev);
 185                         pn->put_online = false;
 186                 }
 187
 188         mutex_unlock(&device->physical_node_lock);
 189
 190         return AE_OK;
 191 }
 192
 193 static int acpi_scan_hot_remove(struct acpi_device *device)
 194 {
 195         acpi_handle handle = device->handle;
 196         struct device *errdev;
 197         acpi_status status;
 198         unsigned long long sta;
 199
 200         /* If there is no handle, the device node has been unregistered. */
 201         if (!handle) {
 202                 dev_dbg(&device->dev, "ACPI handle missing\n");
 203                 put_device(&device->dev);
 204                 return -EINVAL;
 205         }
 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         errdev = NULL;
 217         acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
 218                             NULL, acpi_bus_offline_companions,
 219                             (void *)false, (void **)&errdev);
 220         acpi_bus_offline_companions(handle, 0, (void *)false, (void **)&errdev);
 221         if (errdev) {
 222                 errdev = NULL;
 223                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
 224                                     NULL, acpi_bus_offline_companions,
 225                                     (void *)true , (void **)&errdev);
 226                 if (!errdev || acpi_force_hot_remove)
 227                         acpi_bus_offline_companions(handle, 0, (void *)true,
 228                                                     (void **)&errdev);
 229
 230                 if (errdev && !acpi_force_hot_remove) {
 231                         dev_warn(errdev, "Offline failed.\n");
 232                         acpi_bus_online_companions(handle, 0, NULL, NULL);
 233                         acpi_walk_namespace(ACPI_TYPE_ANY, handle,
 234                                             ACPI_UINT32_MAX,
 235                                             acpi_bus_online_companions, NULL,
 236                                             NULL, NULL);
 237                         put_device(&device->dev);
 238                         return -EBUSY;
 239                 }
 240         }
 241
 242         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 243                 "Hot-removing device %s...\n", dev_name(&device->dev)));
 244
 245         acpi_bus_trim(device);
 246
 247         /* Device node has been unregistered. */
 248         put_device(&device->dev);
 249         device = NULL;
 250
 251         acpi_evaluate_lck(handle, 0);
 252         /*
 253          * TBD: _EJD support.
 254          */
 255         status = acpi_evaluate_ej0(handle);
 256         if (status == AE_NOT_FOUND)
 257                 return -ENODEV;
 258         else if (ACPI_FAILURE(status))
 259                 return -EIO;
 260
 261         /*
 262          * Verify if eject was indeed successful.  If not, log an error
 263          * message.  No need to call _OST since _EJ0 call was made OK.
 264          */
 265         status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
 266         if (ACPI_FAILURE(status)) {
 267                 acpi_handle_warn(handle,
 268                         "Status check after eject failed (0x%x)\n", status);
 269         } else if (sta & ACPI_STA_DEVICE_ENABLED) {
 270                 acpi_handle_warn(handle,
 271                         "Eject incomplete - status 0x%llx\n", sta);
 272         }
 273
 274         return 0;
 275 }
 276
 277 static void acpi_bus_device_eject(void *context)
 278 {
 279         acpi_handle handle = context;
 280         struct acpi_device *device = NULL;
 281         struct acpi_scan_handler *handler;
 282         u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
 283         int error;
 284
 285         lock_device_hotplug();
 286         mutex_lock(&acpi_scan_lock);
 287
 288         acpi_bus_get_device(handle, &device);
 289         if (!device)
 290                 goto err_out;
 291
 292         handler = device->handler;
 293         if (!handler || !handler->hotplug.enabled) {
 294                 ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
 295                 goto err_out;
 296         }
 297         acpi_evaluate_hotplug_ost(handle, ACPI_NOTIFY_EJECT_REQUEST,
 298                                   ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
 299         if (handler->hotplug.mode == AHM_CONTAINER)
 300                 kobject_uevent(&device->dev.kobj, KOBJ_OFFLINE);
 301
 302         get_device(&device->dev);
 303         error = acpi_scan_hot_remove(device);
 304         if (error)
 305                 goto err_out;
 306
 307  out:
 308         mutex_unlock(&acpi_scan_lock);
 309         unlock_device_hotplug();
 310         return;
 311
 312  err_out:
 313         acpi_evaluate_hotplug_ost(handle, ACPI_NOTIFY_EJECT_REQUEST, ost_code,
 314                                   NULL);
 315         goto out;
 316 }
 317
 318 static void acpi_scan_bus_device_check(acpi_handle handle, u32 ost_source)
 319 {
 320         struct acpi_device *device = NULL;
 321         u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
 322         int error;
 323
 324         lock_device_hotplug();
 325         mutex_lock(&acpi_scan_lock);
 326
 327         if (ost_source != ACPI_NOTIFY_BUS_CHECK) {
 328                 acpi_bus_get_device(handle, &device);
 329                 if (device) {
 330                         dev_warn(&device->dev, "Attempt to re-insert\n");
 331                         goto out;
 332                 }
 333         }
 334         acpi_evaluate_hotplug_ost(handle, ost_source,
 335                                   ACPI_OST_SC_INSERT_IN_PROGRESS, NULL);
 336         error = acpi_bus_scan(handle);
 337         if (error) {
 338                 acpi_handle_warn(handle, "Namespace scan failure\n");
 339                 goto out;
 340         }
 341         error = acpi_bus_get_device(handle, &device);
 342         if (error) {
 343                 acpi_handle_warn(handle, "Missing device node object\n");
 344                 goto out;
 345         }
 346         ost_code = ACPI_OST_SC_SUCCESS;
 347         if (device->handler && device->handler->hotplug.mode == AHM_CONTAINER)
 348                 kobject_uevent(&device->dev.kobj, KOBJ_ONLINE);
 349
 350  out:
 351         acpi_evaluate_hotplug_ost(handle, ost_source, ost_code, NULL);
 352         mutex_unlock(&acpi_scan_lock);
 353         unlock_device_hotplug();
 354 }
 355
 356 static void acpi_scan_bus_check(void *context)
 357 {
 358         acpi_scan_bus_device_check((acpi_handle)context,
 359                                    ACPI_NOTIFY_BUS_CHECK);
 360 }
 361
 362 static void acpi_scan_device_check(void *context)
 363 {
 364         acpi_scan_bus_device_check((acpi_handle)context,
 365                                    ACPI_NOTIFY_DEVICE_CHECK);
 366 }
 367
 368 static void acpi_hotplug_unsupported(acpi_handle handle, u32 type)
 369 {
 370         u32 ost_status;
 371
 372         switch (type) {
 373         case ACPI_NOTIFY_BUS_CHECK:
 374                 acpi_handle_debug(handle,
 375                         "ACPI_NOTIFY_BUS_CHECK event: unsupported\n");
 376                 ost_status = ACPI_OST_SC_INSERT_NOT_SUPPORTED;
 377                 break;
 378         case ACPI_NOTIFY_DEVICE_CHECK:
 379                 acpi_handle_debug(handle,
 380                         "ACPI_NOTIFY_DEVICE_CHECK event: unsupported\n");
 381                 ost_status = ACPI_OST_SC_INSERT_NOT_SUPPORTED;
 382                 break;
 383         case ACPI_NOTIFY_EJECT_REQUEST:
 384                 acpi_handle_debug(handle,
 385                         "ACPI_NOTIFY_EJECT_REQUEST event: unsupported\n");
 386                 ost_status = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
 387                 break;
 388         default:
 389                 /* non-hotplug event; possibly handled by other handler */
 390                 return;
 391         }
 392
 393         acpi_evaluate_hotplug_ost(handle, type, ost_status, NULL);
 394 }
 395
 396 static void acpi_hotplug_notify_cb(acpi_handle handle, u32 type, void *data)
 397 {
 398         acpi_osd_exec_callback callback;
 399         struct acpi_scan_handler *handler = data;
 400         acpi_status status;
 401
 402         if (!handler->hotplug.enabled)
 403                 return acpi_hotplug_unsupported(handle, type);
 404
 405         switch (type) {
 406         case ACPI_NOTIFY_BUS_CHECK:
 407                 acpi_handle_debug(handle, "ACPI_NOTIFY_BUS_CHECK event\n");
 408                 callback = acpi_scan_bus_check;
 409                 break;
 410         case ACPI_NOTIFY_DEVICE_CHECK:
 411                 acpi_handle_debug(handle, "ACPI_NOTIFY_DEVICE_CHECK event\n");
 412                 callback = acpi_scan_device_check;
 413                 break;
 414         case ACPI_NOTIFY_EJECT_REQUEST:
 415                 acpi_handle_debug(handle, "ACPI_NOTIFY_EJECT_REQUEST event\n");
 416                 callback = acpi_bus_device_eject;
 417                 break;
 418         default:
 419                 /* non-hotplug event; possibly handled by other handler */
 420                 return;
 421         }
 422         status = acpi_os_hotplug_execute(callback, handle);
 423         if (ACPI_FAILURE(status))
 424                 acpi_evaluate_hotplug_ost(handle, type,
 425                                           ACPI_OST_SC_NON_SPECIFIC_FAILURE,
 426                                           NULL);
 427 }
 428
 429 /**
 430  * acpi_bus_hot_remove_device: hot-remove a device and its children
 431  * @context: struct acpi_eject_event pointer (freed in this func)
 432  *
 433  * Hot-remove a device and its children. This function frees up the
 434  * memory space passed by arg context, so that the caller may call
 435  * this function asynchronously through acpi_os_hotplug_execute().
 436  */
 437 void acpi_bus_hot_remove_device(void *context)
 438 {
 439         struct acpi_eject_event *ej_event = context;
 440         struct acpi_device *device = ej_event->device;
 441         acpi_handle handle = device->handle;
 442         int error;
 443
 444         lock_device_hotplug();
 445         mutex_lock(&acpi_scan_lock);
 446
 447         error = acpi_scan_hot_remove(device);
 448         if (error && handle)
 449                 acpi_evaluate_hotplug_ost(handle, ej_event->event,
 450                                           ACPI_OST_SC_NON_SPECIFIC_FAILURE,
 451                                           NULL);
 452
 453         mutex_unlock(&acpi_scan_lock);
 454         unlock_device_hotplug();
 455         kfree(context);
 456 }
 457 EXPORT_SYMBOL(acpi_bus_hot_remove_device);
 458
 459 static ssize_t real_power_state_show(struct device *dev,
 460                                      struct device_attribute *attr, char *buf)
 461 {
 462         struct acpi_device *adev = to_acpi_device(dev);
 463         int state;
 464         int ret;
 465
 466         ret = acpi_device_get_power(adev, &state);
 467         if (ret)
 468                 return ret;
 469
 470         return sprintf(buf, "%s\n", acpi_power_state_string(state));
 471 }
 472
 473 static DEVICE_ATTR(real_power_state, 0444, real_power_state_show, NULL);
 474
 475 static ssize_t power_state_show(struct device *dev,
 476                                 struct device_attribute *attr, char *buf)
 477 {
 478         struct acpi_device *adev = to_acpi_device(dev);
 479
 480         return sprintf(buf, "%s\n", acpi_power_state_string(adev->power.state));
 481 }
 482
 483 static DEVICE_ATTR(power_state, 0444, power_state_show, NULL);
 484
 485 static ssize_t
 486 acpi_eject_store(struct device *d, struct device_attribute *attr,
 487                 const char *buf, size_t count)
 488 {
 489         struct acpi_device *acpi_device = to_acpi_device(d);
 490         struct acpi_eject_event *ej_event;
 491         acpi_object_type not_used;
 492         acpi_status status;
 493         int ret;
 494
 495         if (!count || buf[0] != '1')
 496                 return -EINVAL;
 497
 498         if ((!acpi_device->handler || !acpi_device->handler->hotplug.enabled)
 499             && !acpi_device->driver)
 500                 return -ENODEV;
 501
 502         status = acpi_get_type(acpi_device->handle, &not_used);
 503         if (ACPI_FAILURE(status) || !acpi_device->flags.ejectable)
 504                 return -ENODEV;
 505
 506         ej_event = kmalloc(sizeof(*ej_event), GFP_KERNEL);
 507         if (!ej_event) {
 508                 ret = -ENOMEM;
 509                 goto err_out;
 510         }
 511         acpi_evaluate_hotplug_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,
 512                                   ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
 513         ej_event->device = acpi_device;
 514         ej_event->event = ACPI_OST_EC_OSPM_EJECT;
 515         get_device(&acpi_device->dev);
 516         status = acpi_os_hotplug_execute(acpi_bus_hot_remove_device, ej_event);
 517         if (ACPI_SUCCESS(status))
 518                 return count;
 519
 520         put_device(&acpi_device->dev);
 521         kfree(ej_event);
 522         ret = status == AE_NO_MEMORY ? -ENOMEM : -EAGAIN;
 523
 524  err_out:
 525         acpi_evaluate_hotplug_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,
 526                                   ACPI_OST_SC_NON_SPECIFIC_FAILURE, NULL);
 527         return ret;
 528 }
 529
 530 static DEVICE_ATTR(eject, 0200, NULL, acpi_eject_store);
 531
 532 static ssize_t
 533 acpi_device_hid_show(struct device *dev, struct device_attribute *attr, char *buf) {
 534         struct acpi_device *acpi_dev = to_acpi_device(dev);
 535
 536         return sprintf(buf, "%s\n", acpi_device_hid(acpi_dev));
 537 }
 538 static DEVICE_ATTR(hid, 0444, acpi_device_hid_show, NULL);
 539
 540 static ssize_t acpi_device_uid_show(struct device *dev,
 541                                     struct device_attribute *attr, char *buf)
 542 {
 543         struct acpi_device *acpi_dev = to_acpi_device(dev);
 544
 545         return sprintf(buf, "%s\n", acpi_dev->pnp.unique_id);
 546 }
 547 static DEVICE_ATTR(uid, 0444, acpi_device_uid_show, NULL);
 548
 549 static ssize_t acpi_device_adr_show(struct device *dev,
 550                                     struct device_attribute *attr, char *buf)
 551 {
 552         struct acpi_device *acpi_dev = to_acpi_device(dev);
 553
 554         return sprintf(buf, "0x%08x\n",
 555                        (unsigned int)(acpi_dev->pnp.bus_address));
 556 }
 557 static DEVICE_ATTR(adr, 0444, acpi_device_adr_show, NULL);
 558
 559 static ssize_t
 560 acpi_device_path_show(struct device *dev, struct device_attribute *attr, char *buf) {
 561         struct acpi_device *acpi_dev = to_acpi_device(dev);
 562         struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
 563         int result;
 564
 565         result = acpi_get_name(acpi_dev->handle, ACPI_FULL_PATHNAME, &path);
 566         if (result)
 567                 goto end;
 568
 569         result = sprintf(buf, "%s\n", (char*)path.pointer);
 570         kfree(path.pointer);
 571 end:
 572         return result;
 573 }
 574 static DEVICE_ATTR(path, 0444, acpi_device_path_show, NULL);
 575
 576 /* sysfs file that shows description text from the ACPI _STR method */
 577 static ssize_t description_show(struct device *dev,
 578                                 struct device_attribute *attr,
 579                                 char *buf) {
 580         struct acpi_device *acpi_dev = to_acpi_device(dev);
 581         int result;
 582
 583         if (acpi_dev->pnp.str_obj == NULL)
 584                 return 0;
 585
 586         /*
 587          * The _STR object contains a Unicode identifier for a device.
 588          * We need to convert to utf-8 so it can be displayed.
 589          */
 590         result = utf16s_to_utf8s(
 591                 (wchar_t *)acpi_dev->pnp.str_obj->buffer.pointer,
 592                 acpi_dev->pnp.str_obj->buffer.length,
 593                 UTF16_LITTLE_ENDIAN, buf,
 594                 PAGE_SIZE);
 595
 596         buf[result++] = '\n';
 597
 598         return result;
 599 }
 600 static DEVICE_ATTR(description, 0444, description_show, NULL);
 601
 602 static ssize_t
 603 acpi_device_sun_show(struct device *dev, struct device_attribute *attr,
 604                      char *buf) {
 605         struct acpi_device *acpi_dev = to_acpi_device(dev);
 606
 607         return sprintf(buf, "%lu\n", acpi_dev->pnp.sun);
 608 }
 609 static DEVICE_ATTR(sun, 0444, acpi_device_sun_show, NULL);
 610
 611 static int acpi_device_setup_files(struct acpi_device *dev)
 612 {
 613         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
 614         acpi_status status;
 615         unsigned long long sun;
 616         int result = 0;
 617
 618         /*
 619          * Devices gotten from FADT don't have a "path" attribute
 620          */
 621         if (dev->handle) {
 622                 result = device_create_file(&dev->dev, &dev_attr_path);
 623                 if (result)
 624                         goto end;
 625         }
 626
 627         if (!list_empty(&dev->pnp.ids)) {
 628                 result = device_create_file(&dev->dev, &dev_attr_hid);
 629                 if (result)
 630                         goto end;
 631
 632                 result = device_create_file(&dev->dev, &dev_attr_modalias);
 633                 if (result)
 634                         goto end;
 635         }
 636
 637         /*
 638          * If device has _STR, 'description' file is created
 639          */
 640         if (acpi_has_method(dev->handle, "_STR")) {
 641                 status = acpi_evaluate_object(dev->handle, "_STR",
 642                                         NULL, &buffer);
 643                 if (ACPI_FAILURE(status))
 644                         buffer.pointer = NULL;
 645                 dev->pnp.str_obj = buffer.pointer;
 646                 result = device_create_file(&dev->dev, &dev_attr_description);
 647                 if (result)
 648                         goto end;
 649         }
 650
 651         if (dev->pnp.type.bus_address)
 652                 result = device_create_file(&dev->dev, &dev_attr_adr);
 653         if (dev->pnp.unique_id)
 654                 result = device_create_file(&dev->dev, &dev_attr_uid);
 655
 656         status = acpi_evaluate_integer(dev->handle, "_SUN", NULL, &sun);
 657         if (ACPI_SUCCESS(status)) {
 658                 dev->pnp.sun = (unsigned long)sun;
 659                 result = device_create_file(&dev->dev, &dev_attr_sun);
 660                 if (result)
 661                         goto end;
 662         } else {
 663                 dev->pnp.sun = (unsigned long)-1;
 664         }
 665
 666         /*
 667          * If device has _EJ0, 'eject' file is created that is used to trigger
 668          * hot-removal function from userland.
 669          */
 670         if (acpi_has_method(dev->handle, "_EJ0")) {
 671                 result = device_create_file(&dev->dev, &dev_attr_eject);
 672                 if (result)
 673                         return result;
 674         }
 675
 676         if (dev->flags.power_manageable) {
 677                 result = device_create_file(&dev->dev, &dev_attr_power_state);
 678                 if (result)
 679                         return result;
 680
 681                 if (dev->power.flags.power_resources)
 682                         result = device_create_file(&dev->dev,
 683                                                     &dev_attr_real_power_state);
 684         }
 685
 686 end:
 687         return result;
 688 }
 689
 690 static void acpi_device_remove_files(struct acpi_device *dev)
 691 {
 692         if (dev->flags.power_manageable) {
 693                 device_remove_file(&dev->dev, &dev_attr_power_state);
 694                 if (dev->power.flags.power_resources)
 695                         device_remove_file(&dev->dev,
 696                                            &dev_attr_real_power_state);
 697         }
 698
 699         /*
 700          * If device has _STR, remove 'description' file
 701          */
 702         if (acpi_has_method(dev->handle, "_STR")) {
 703                 kfree(dev->pnp.str_obj);
 704                 device_remove_file(&dev->dev, &dev_attr_description);
 705         }
 706         /*
 707          * If device has _EJ0, remove 'eject' file.
 708          */
 709         if (acpi_has_method(dev->handle, "_EJ0"))
 710                 device_remove_file(&dev->dev, &dev_attr_eject);
 711
 712         if (acpi_has_method(dev->handle, "_SUN"))
 713                 device_remove_file(&dev->dev, &dev_attr_sun);
 714
 715         if (dev->pnp.unique_id)
 716                 device_remove_file(&dev->dev, &dev_attr_uid);
 717         if (dev->pnp.type.bus_address)
 718                 device_remove_file(&dev->dev, &dev_attr_adr);
 719         device_remove_file(&dev->dev, &dev_attr_modalias);
 720         device_remove_file(&dev->dev, &dev_attr_hid);
 721         if (dev->handle)
 722                 device_remove_file(&dev->dev, &dev_attr_path);
 723 }
 724 /* --------------------------------------------------------------------------
 725                         ACPI Bus operations
 726    -------------------------------------------------------------------------- */
 727
 728 static const struct acpi_device_id *__acpi_match_device(
 729         struct acpi_device *device, const struct acpi_device_id *ids)
 730 {
 731         const struct acpi_device_id *id;
 732         struct acpi_hardware_id *hwid;
 733
 734         /*
 735          * If the device is not present, it is unnecessary to load device
 736          * driver for it.
 737          */
 738         if (!device->status.present)
 739                 return NULL;
 740
 741         for (id = ids; id->id[0]; id++)
 742                 list_for_each_entry(hwid, &device->pnp.ids, list)
 743                         if (!strcmp((char *) id->id, hwid->id))
 744                                 return id;
 745
 746         return NULL;
 747 }
 748
 749 /**
 750  * acpi_match_device - Match a struct device against a given list of ACPI IDs
 751  * @ids: Array of struct acpi_device_id object to match against.
 752  * @dev: The device structure to match.
 753  *
 754  * Check if @dev has a valid ACPI handle and if there is a struct acpi_device
 755  * object for that handle and use that object to match against a given list of
 756  * device IDs.
 757  *
 758  * Return a pointer to the first matching ID on success or %NULL on failure.
 759  */
 760 const struct acpi_device_id *acpi_match_device(const struct acpi_device_id *ids,
 761                                                const struct device *dev)
 762 {
 763         struct acpi_device *adev;
 764         acpi_handle handle = ACPI_HANDLE(dev);
 765
 766         if (!ids || !handle || acpi_bus_get_device(handle, &adev))
 767                 return NULL;
 768
 769         return __acpi_match_device(adev, ids);
 770 }
 771 EXPORT_SYMBOL_GPL(acpi_match_device);
 772
 773 int acpi_match_device_ids(struct acpi_device *device,
 774                           const struct acpi_device_id *ids)
 775 {
 776         return __acpi_match_device(device, ids) ? 0 : -ENOENT;
 777 }
 778 EXPORT_SYMBOL(acpi_match_device_ids);
 779
 780 static void acpi_free_power_resources_lists(struct acpi_device *device)
 781 {
 782         int i;
 783
 784         if (device->wakeup.flags.valid)
 785                 acpi_power_resources_list_free(&device->wakeup.resources);
 786
 787         if (!device->flags.power_manageable)
 788                 return;
 789
 790         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
 791                 struct acpi_device_power_state *ps = &device->power.states[i];
 792                 acpi_power_resources_list_free(&ps->resources);
 793         }
 794 }
 795
 796 static void acpi_device_release(struct device *dev)
 797 {
 798         struct acpi_device *acpi_dev = to_acpi_device(dev);
 799
 800         acpi_free_pnp_ids(&acpi_dev->pnp);
 801         acpi_free_power_resources_lists(acpi_dev);
 802         kfree(acpi_dev);
 803 }
 804
 805 static int acpi_bus_match(struct device *dev, struct device_driver *drv)
 806 {
 807         struct acpi_device *acpi_dev = to_acpi_device(dev);
 808         struct acpi_driver *acpi_drv = to_acpi_driver(drv);
 809
 810         return acpi_dev->flags.match_driver
 811                 && !acpi_match_device_ids(acpi_dev, acpi_drv->ids);
 812 }
 813
 814 static int acpi_device_uevent(struct device *dev, struct kobj_uevent_env *env)
 815 {
 816         struct acpi_device *acpi_dev = to_acpi_device(dev);
 817         int len;
 818
 819         if (list_empty(&acpi_dev->pnp.ids))
 820                 return 0;
 821
 822         if (add_uevent_var(env, "MODALIAS="))
 823                 return -ENOMEM;
 824         len = create_modalias(acpi_dev, &env->buf[env->buflen - 1],
 825                               sizeof(env->buf) - env->buflen);
 826         if (len >= (sizeof(env->buf) - env->buflen))
 827                 return -ENOMEM;
 828         env->buflen += len;
 829         return 0;
 830 }
 831
 832 static void acpi_device_notify(acpi_handle handle, u32 event, void *data)
 833 {
 834         struct acpi_device *device = data;
 835
 836         device->driver->ops.notify(device, event);
 837 }
 838
 839 static acpi_status acpi_device_notify_fixed(void *data)
 840 {
 841         struct acpi_device *device = data;
 842
 843         /* Fixed hardware devices have no handles */
 844         acpi_device_notify(NULL, ACPI_FIXED_HARDWARE_EVENT, device);
 845         return AE_OK;
 846 }
 847
 848 static int acpi_device_install_notify_handler(struct acpi_device *device)
 849 {
 850         acpi_status status;
 851
 852         if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
 853                 status =
 854                     acpi_install_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
 855                                                      acpi_device_notify_fixed,
 856                                                      device);
 857         else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
 858                 status =
 859                     acpi_install_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
 860                                                      acpi_device_notify_fixed,
 861                                                      device);
 862         else
 863                 status = acpi_install_notify_handler(device->handle,
 864                                                      ACPI_DEVICE_NOTIFY,
 865                                                      acpi_device_notify,
 866                                                      device);
 867
 868         if (ACPI_FAILURE(status))
 869                 return -EINVAL;
 870         return 0;
 871 }
 872
 873 static void acpi_device_remove_notify_handler(struct acpi_device *device)
 874 {
 875         if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
 876                 acpi_remove_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
 877                                                 acpi_device_notify_fixed);
 878         else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
 879                 acpi_remove_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
 880                                                 acpi_device_notify_fixed);
 881         else
 882                 acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
 883                                            acpi_device_notify);
 884 }
 885
 886 static int acpi_device_probe(struct device *dev)
 887 {
 888         struct acpi_device *acpi_dev = to_acpi_device(dev);
 889         struct acpi_driver *acpi_drv = to_acpi_driver(dev->driver);
 890         int ret;
 891
 892         if (acpi_dev->handler)
 893                 return -EINVAL;
 894
 895         if (!acpi_drv->ops.add)
 896                 return -ENOSYS;
 897
 898         ret = acpi_drv->ops.add(acpi_dev);
 899         if (ret)
 900                 return ret;
 901
 902         acpi_dev->driver = acpi_drv;
 903         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 904                           "Driver [%s] successfully bound to device [%s]\n",
 905                           acpi_drv->name, acpi_dev->pnp.bus_id));
 906
 907         if (acpi_drv->ops.notify) {
 908                 ret = acpi_device_install_notify_handler(acpi_dev);
 909                 if (ret) {
 910                         if (acpi_drv->ops.remove)
 911                                 acpi_drv->ops.remove(acpi_dev);
 912
 913                         acpi_dev->driver = NULL;
 914                         acpi_dev->driver_data = NULL;
 915                         return ret;
 916                 }
 917         }
 918
 919         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found driver [%s] for device [%s]\n",
 920                           acpi_drv->name, acpi_dev->pnp.bus_id));
 921         get_device(dev);
 922         return 0;
 923 }
 924
 925 static int acpi_device_remove(struct device * dev)
 926 {
 927         struct acpi_device *acpi_dev = to_acpi_device(dev);
 928         struct acpi_driver *acpi_drv = acpi_dev->driver;
 929
 930         if (acpi_drv) {
 931                 if (acpi_drv->ops.notify)
 932                         acpi_device_remove_notify_handler(acpi_dev);
 933                 if (acpi_drv->ops.remove)
 934                         acpi_drv->ops.remove(acpi_dev);
 935         }
 936         acpi_dev->driver = NULL;
 937         acpi_dev->driver_data = NULL;
 938
 939         put_device(dev);
 940         return 0;
 941 }
 942
 943 struct bus_type acpi_bus_type = {
 944         .name           = "acpi",
 945         .match          = acpi_bus_match,
 946         .probe          = acpi_device_probe,
 947         .remove         = acpi_device_remove,
 948         .uevent         = acpi_device_uevent,
 949 };
 950
 951 static void acpi_bus_data_handler(acpi_handle handle, void *context)
 952 {
 953         /* Intentionally empty. */
 954 }
 955
 956 int acpi_bus_get_device(acpi_handle handle, struct acpi_device **device)
 957 {
 958         acpi_status status;
 959
 960         if (!device)
 961                 return -EINVAL;
 962
 963         status = acpi_get_data(handle, acpi_bus_data_handler, (void **)device);
 964         if (ACPI_FAILURE(status) || !*device) {
 965                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No context for object [%p]\n",
 966                                   handle));
 967                 return -ENODEV;
 968         }
 969         return 0;
 970 }
 971 EXPORT_SYMBOL(acpi_bus_get_device);
 972
 973 int acpi_device_add(struct acpi_device *device,
 974                     void (*release)(struct device *))
 975 {
 976         int result;
 977         struct acpi_device_bus_id *acpi_device_bus_id, *new_bus_id;
 978         int found = 0;
 979
 980         if (device->handle) {
 981                 acpi_status status;
 982
 983                 status = acpi_attach_data(device->handle, acpi_bus_data_handler,
 984                                           device);
 985                 if (ACPI_FAILURE(status)) {
 986                         acpi_handle_err(device->handle,
 987                                         "Unable to attach device data\n");
 988                         return -ENODEV;
 989                 }
 990         }
 991
 992         /*
 993          * Linkage
 994          * -------
 995          * Link this device to its parent and siblings.
 996          */
 997         INIT_LIST_HEAD(&device->children);
 998         INIT_LIST_HEAD(&device->node);
 999         INIT_LIST_HEAD(&device->wakeup_list);
1000         INIT_LIST_HEAD(&device->physical_node_list);
1001         mutex_init(&device->physical_node_lock);
1002
1003         new_bus_id = kzalloc(sizeof(struct acpi_device_bus_id), GFP_KERNEL);
1004         if (!new_bus_id) {
1005                 pr_err(PREFIX "Memory allocation error\n");
1006                 result = -ENOMEM;
1007                 goto err_detach;
1008         }
1009
1010         mutex_lock(&acpi_device_lock);
1011         /*
1012          * Find suitable bus_id and instance number in acpi_bus_id_list
1013          * If failed, create one and link it into acpi_bus_id_list
1014          */
1015         list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
1016                 if (!strcmp(acpi_device_bus_id->bus_id,
1017                             acpi_device_hid(device))) {
1018                         acpi_device_bus_id->instance_no++;
1019                         found = 1;
1020                         kfree(new_bus_id);
1021                         break;
1022                 }
1023         }
1024         if (!found) {
1025                 acpi_device_bus_id = new_bus_id;
1026                 strcpy(acpi_device_bus_id->bus_id, acpi_device_hid(device));
1027                 acpi_device_bus_id->instance_no = 0;
1028                 list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
1029         }
1030         dev_set_name(&device->dev, "%s:%02x", acpi_device_bus_id->bus_id, acpi_device_bus_id->instance_no);
1031
1032         if (device->parent)
1033                 list_add_tail(&device->node, &device->parent->children);
1034
1035         if (device->wakeup.flags.valid)
1036                 list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);
1037         mutex_unlock(&acpi_device_lock);
1038
1039         if (device->parent)
1040                 device->dev.parent = &device->parent->dev;
1041         device->dev.bus = &acpi_bus_type;
1042         device->dev.release = release;
1043         result = device_add(&device->dev);
1044         if (result) {
1045                 dev_err(&device->dev, "Error registering device\n");
1046                 goto err;
1047         }
1048
1049         result = acpi_device_setup_files(device);
1050         if (result)
1051                 printk(KERN_ERR PREFIX "Error creating sysfs interface for device %s\n",
1052                        dev_name(&device->dev));
1053
1054         return 0;
1055
1056  err:
1057         mutex_lock(&acpi_device_lock);
1058         if (device->parent)
1059                 list_del(&device->node);
1060         list_del(&device->wakeup_list);
1061         mutex_unlock(&acpi_device_lock);
1062
1063  err_detach:
1064         acpi_detach_data(device->handle, acpi_bus_data_handler);
1065         return result;
1066 }
1067
1068 static void acpi_device_unregister(struct acpi_device *device)
1069 {
1070         mutex_lock(&acpi_device_lock);
1071         if (device->parent)
1072                 list_del(&device->node);
1073
1074         list_del(&device->wakeup_list);
1075         mutex_unlock(&acpi_device_lock);
1076
1077         acpi_detach_data(device->handle, acpi_bus_data_handler);
1078
1079         acpi_power_add_remove_device(device, false);
1080         acpi_device_remove_files(device);
1081         if (device->remove)
1082                 device->remove(device);
1083
1084         device_del(&device->dev);
1085         /*
1086          * Transition the device to D3cold to drop the reference counts of all
1087          * power resources the device depends on and turn off the ones that have
1088          * no more references.
1089          */
1090         acpi_device_set_power(device, ACPI_STATE_D3_COLD);
1091         device->handle = NULL;
1092         put_device(&device->dev);
1093 }
1094
1095 /* --------------------------------------------------------------------------
1096                                  Driver Management
1097    -------------------------------------------------------------------------- */
1098 /**
1099  * acpi_bus_register_driver - register a driver with the ACPI bus
1100  * @driver: driver being registered
1101  *
1102  * Registers a driver with the ACPI bus.  Searches the namespace for all
1103  * devices that match the driver's criteria and binds.  Returns zero for
1104  * success or a negative error status for failure.
1105  */
1106 int acpi_bus_register_driver(struct acpi_driver *driver)
1107 {
1108         int ret;
1109
1110         if (acpi_disabled)
1111                 return -ENODEV;
1112         driver->drv.name = driver->name;
1113         driver->drv.bus = &acpi_bus_type;
1114         driver->drv.owner = driver->owner;
1115
1116         ret = driver_register(&driver->drv);
1117         return ret;
1118 }
1119
1120 EXPORT_SYMBOL(acpi_bus_register_driver);
1121
1122 /**
1123  * acpi_bus_unregister_driver - unregisters a driver with the ACPI bus
1124  * @driver: driver to unregister
1125  *
1126  * Unregisters a driver with the ACPI bus.  Searches the namespace for all
1127  * devices that match the driver's criteria and unbinds.
1128  */
1129 void acpi_bus_unregister_driver(struct acpi_driver *driver)
1130 {
1131         driver_unregister(&driver->drv);
1132 }
1133
1134 EXPORT_SYMBOL(acpi_bus_unregister_driver);
1135
1136 /* --------------------------------------------------------------------------
1137                                  Device Enumeration
1138    -------------------------------------------------------------------------- */
1139 static struct acpi_device *acpi_bus_get_parent(acpi_handle handle)
1140 {
1141         struct acpi_device *device = NULL;
1142         acpi_status status;
1143
1144         /*
1145          * Fixed hardware devices do not appear in the namespace and do not
1146          * have handles, but we fabricate acpi_devices for them, so we have
1147          * to deal with them specially.
1148          */
1149         if (!handle)
1150                 return acpi_root;
1151
1152         do {
1153                 status = acpi_get_parent(handle, &handle);
1154                 if (ACPI_FAILURE(status))
1155                         return status == AE_NULL_ENTRY ? NULL : acpi_root;
1156         } while (acpi_bus_get_device(handle, &device));
1157         return device;
1158 }
1159
1160 acpi_status
1161 acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
1162 {
1163         acpi_status status;
1164         acpi_handle tmp;
1165         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
1166         union acpi_object *obj;
1167
1168         status = acpi_get_handle(handle, "_EJD", &tmp);
1169         if (ACPI_FAILURE(status))
1170                 return status;
1171
1172         status = acpi_evaluate_object(handle, "_EJD", NULL, &buffer);
1173         if (ACPI_SUCCESS(status)) {
1174                 obj = buffer.pointer;
1175                 status = acpi_get_handle(ACPI_ROOT_OBJECT, obj->string.pointer,
1176                                          ejd);
1177                 kfree(buffer.pointer);
1178         }
1179         return status;
1180 }
1181 EXPORT_SYMBOL_GPL(acpi_bus_get_ejd);
1182
1183 static int acpi_bus_extract_wakeup_device_power_package(acpi_handle handle,
1184                                         struct acpi_device_wakeup *wakeup)
1185 {
1186         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1187         union acpi_object *package = NULL;
1188         union acpi_object *element = NULL;
1189         acpi_status status;
1190         int err = -ENODATA;
1191
1192         if (!wakeup)
1193                 return -EINVAL;
1194
1195         INIT_LIST_HEAD(&wakeup->resources);
1196
1197         /* _PRW */
1198         status = acpi_evaluate_object(handle, "_PRW", NULL, &buffer);
1199         if (ACPI_FAILURE(status)) {
1200                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRW"));
1201                 return err;
1202         }
1203
1204         package = (union acpi_object *)buffer.pointer;
1205
1206         if (!package || package->package.count < 2)
1207                 goto out;
1208
1209         element = &(package->package.elements[0]);
1210         if (!element)
1211                 goto out;
1212
1213         if (element->type == ACPI_TYPE_PACKAGE) {
1214                 if ((element->package.count < 2) ||
1215                     (element->package.elements[0].type !=
1216                      ACPI_TYPE_LOCAL_REFERENCE)
1217                     || (element->package.elements[1].type != ACPI_TYPE_INTEGER))
1218                         goto out;
1219
1220                 wakeup->gpe_device =
1221                     element->package.elements[0].reference.handle;
1222                 wakeup->gpe_number =
1223                     (u32) element->package.elements[1].integer.value;
1224         } else if (element->type == ACPI_TYPE_INTEGER) {
1225                 wakeup->gpe_device = NULL;
1226                 wakeup->gpe_number = element->integer.value;
1227         } else {
1228                 goto out;
1229         }
1230
1231         element = &(package->package.elements[1]);
1232         if (element->type != ACPI_TYPE_INTEGER)
1233                 goto out;
1234
1235         wakeup->sleep_state = element->integer.value;
1236
1237         err = acpi_extract_power_resources(package, 2, &wakeup->resources);
1238         if (err)
1239                 goto out;
1240
1241         if (!list_empty(&wakeup->resources)) {
1242                 int sleep_state;
1243
1244                 err = acpi_power_wakeup_list_init(&wakeup->resources,
1245                                                   &sleep_state);
1246                 if (err) {
1247                         acpi_handle_warn(handle, "Retrieving current states "
1248                                          "of wakeup power resources failed\n");
1249                         acpi_power_resources_list_free(&wakeup->resources);
1250                         goto out;
1251                 }
1252                 if (sleep_state < wakeup->sleep_state) {
1253                         acpi_handle_warn(handle, "Overriding _PRW sleep state "
1254                                          "(S%d) by S%d from power resources\n",
1255                                          (int)wakeup->sleep_state, sleep_state);
1256                         wakeup->sleep_state = sleep_state;
1257                 }
1258         }
1259         acpi_setup_gpe_for_wake(handle, wakeup->gpe_device, wakeup->gpe_number);
1260
1261  out:
1262         kfree(buffer.pointer);
1263         return err;
1264 }
1265
1266 static void acpi_bus_set_run_wake_flags(struct acpi_device *device)
1267 {
1268         struct acpi_device_id button_device_ids[] = {
1269                 {"PNP0C0C", 0},
1270                 {"PNP0C0D", 0},
1271                 {"PNP0C0E", 0},
1272                 {"", 0},
1273         };
1274         acpi_status status;
1275         acpi_event_status event_status;
1276
1277         device->wakeup.flags.notifier_present = 0;
1278
1279         /* Power button, Lid switch always enable wakeup */
1280         if (!acpi_match_device_ids(device, button_device_ids)) {
1281                 device->wakeup.flags.run_wake = 1;
1282                 if (!acpi_match_device_ids(device, &button_device_ids[1])) {
1283                         /* Do not use Lid/sleep button for S5 wakeup */
1284                         if (device->wakeup.sleep_state == ACPI_STATE_S5)
1285                                 device->wakeup.sleep_state = ACPI_STATE_S4;
1286                 }
1287                 device_set_wakeup_capable(&device->dev, true);
1288                 return;
1289         }
1290
1291         status = acpi_get_gpe_status(device->wakeup.gpe_device,
1292                                         device->wakeup.gpe_number,
1293                                                 &event_status);
1294         if (status == AE_OK)
1295                 device->wakeup.flags.run_wake =
1296                                 !!(event_status & ACPI_EVENT_FLAG_HANDLE);
1297 }
1298
1299 static void acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
1300 {
1301         int err;
1302
1303         /* Presence of _PRW indicates wake capable */
1304         if (!acpi_has_method(device->handle, "_PRW"))
1305                 return;
1306
1307         err = acpi_bus_extract_wakeup_device_power_package(device->handle,
1308                                                            &device->wakeup);
1309         if (err) {
1310                 dev_err(&device->dev, "_PRW evaluation error: %d\n", err);
1311                 return;
1312         }
1313
1314         device->wakeup.flags.valid = 1;
1315         device->wakeup.prepare_count = 0;
1316         acpi_bus_set_run_wake_flags(device);
1317         /* Call _PSW/_DSW object to disable its ability to wake the sleeping
1318          * system for the ACPI device with the _PRW object.
1319          * The _PSW object is depreciated in ACPI 3.0 and is replaced by _DSW.
1320          * So it is necessary to call _DSW object first. Only when it is not
1321          * present will the _PSW object used.
1322          */
1323         err = acpi_device_sleep_wake(device, 0, 0, 0);
1324         if (err)
1325                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1326                                 "error in _DSW or _PSW evaluation\n"));
1327 }
1328
1329 static void acpi_bus_init_power_state(struct acpi_device *device, int state)
1330 {
1331         struct acpi_device_power_state *ps = &device->power.states[state];
1332         char pathname[5] = { '_', 'P', 'R', '0' + state, '\0' };
1333         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1334         acpi_status status;
1335
1336         INIT_LIST_HEAD(&ps->resources);
1337
1338         /* Evaluate "_PRx" to get referenced power resources */
1339         status = acpi_evaluate_object(device->handle, pathname, NULL, &buffer);
1340         if (ACPI_SUCCESS(status)) {
1341                 union acpi_object *package = buffer.pointer;
1342
1343                 if (buffer.length && package
1344                     && package->type == ACPI_TYPE_PACKAGE
1345                     && package->package.count) {
1346                         int err = acpi_extract_power_resources(package, 0,
1347                                                                &ps->resources);
1348                         if (!err)
1349                                 device->power.flags.power_resources = 1;
1350                 }
1351                 ACPI_FREE(buffer.pointer);
1352         }
1353
1354         /* Evaluate "_PSx" to see if we can do explicit sets */
1355         pathname[2] = 'S';
1356         if (acpi_has_method(device->handle, pathname))
1357                 ps->flags.explicit_set = 1;
1358
1359         /*
1360          * State is valid if there are means to put the device into it.
1361          * D3hot is only valid if _PR3 present.
1362          */
1363         if (!list_empty(&ps->resources)
1364             || (ps->flags.explicit_set && state < ACPI_STATE_D3_HOT)) {
1365                 ps->flags.valid = 1;
1366                 ps->flags.os_accessible = 1;
1367         }
1368
1369         ps->power = -1;         /* Unknown - driver assigned */
1370         ps->latency = -1;       /* Unknown - driver assigned */
1371 }
1372
1373 static void acpi_bus_get_power_flags(struct acpi_device *device)
1374 {
1375         u32 i;
1376
1377         /* Presence of _PS0|_PR0 indicates 'power manageable' */
1378         if (!acpi_has_method(device->handle, "_PS0") &&
1379             !acpi_has_method(device->handle, "_PR0"))
1380                 return;
1381
1382         device->flags.power_manageable = 1;
1383
1384         /*
1385          * Power Management Flags
1386          */
1387         if (acpi_has_method(device->handle, "_PSC"))
1388                 device->power.flags.explicit_get = 1;
1389         if (acpi_has_method(device->handle, "_IRC"))
1390                 device->power.flags.inrush_current = 1;
1391
1392         /*
1393          * Enumerate supported power management states
1394          */
1395         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++)
1396                 acpi_bus_init_power_state(device, i);
1397
1398         INIT_LIST_HEAD(&device->power.states[ACPI_STATE_D3_COLD].resources);
1399
1400         /* Set defaults for D0 and D3 states (always valid) */
1401         device->power.states[ACPI_STATE_D0].flags.valid = 1;
1402         device->power.states[ACPI_STATE_D0].power = 100;
1403         device->power.states[ACPI_STATE_D3_COLD].flags.valid = 1;
1404         device->power.states[ACPI_STATE_D3_COLD].power = 0;
1405
1406         /* Set D3cold's explicit_set flag if _PS3 exists. */
1407         if (device->power.states[ACPI_STATE_D3_HOT].flags.explicit_set)
1408                 device->power.states[ACPI_STATE_D3_COLD].flags.explicit_set = 1;
1409
1410         /* Presence of _PS3 or _PRx means we can put the device into D3 cold */
1411         if (device->power.states[ACPI_STATE_D3_HOT].flags.explicit_set ||
1412                         device->power.flags.power_resources)
1413                 device->power.states[ACPI_STATE_D3_COLD].flags.os_accessible = 1;
1414
1415         if (acpi_bus_init_power(device)) {
1416                 acpi_free_power_resources_lists(device);
1417                 device->flags.power_manageable = 0;
1418         }
1419 }
1420
1421 static void acpi_bus_get_flags(struct acpi_device *device)
1422 {
1423         /* Presence of _STA indicates 'dynamic_status' */
1424         if (acpi_has_method(device->handle, "_STA"))
1425                 device->flags.dynamic_status = 1;
1426
1427         /* Presence of _RMV indicates 'removable' */
1428         if (acpi_has_method(device->handle, "_RMV"))
1429                 device->flags.removable = 1;
1430
1431         /* Presence of _EJD|_EJ0 indicates 'ejectable' */
1432         if (acpi_has_method(device->handle, "_EJD") ||
1433             acpi_has_method(device->handle, "_EJ0"))
1434                 device->flags.ejectable = 1;
1435 }
1436
1437 static void acpi_device_get_busid(struct acpi_device *device)
1438 {
1439         char bus_id[5] = { '?', 0 };
1440         struct acpi_buffer buffer = { sizeof(bus_id), bus_id };
1441         int i = 0;
1442
1443         /*
1444          * Bus ID
1445          * ------
1446          * The device's Bus ID is simply the object name.
1447          * TBD: Shouldn't this value be unique (within the ACPI namespace)?
1448          */
1449         if (ACPI_IS_ROOT_DEVICE(device)) {
1450                 strcpy(device->pnp.bus_id, "ACPI");
1451                 return;
1452         }
1453
1454         switch (device->device_type) {
1455         case ACPI_BUS_TYPE_POWER_BUTTON:
1456                 strcpy(device->pnp.bus_id, "PWRF");
1457                 break;
1458         case ACPI_BUS_TYPE_SLEEP_BUTTON:
1459                 strcpy(device->pnp.bus_id, "SLPF");
1460                 break;
1461         default:
1462                 acpi_get_name(device->handle, ACPI_SINGLE_NAME, &buffer);
1463                 /* Clean up trailing underscores (if any) */
1464                 for (i = 3; i > 1; i--) {
1465                         if (bus_id[i] == '_')
1466                                 bus_id[i] = '\0';
1467                         else
1468                                 break;
1469                 }
1470                 strcpy(device->pnp.bus_id, bus_id);
1471                 break;
1472         }
1473 }
1474
1475 /*
1476  * acpi_ata_match - see if an acpi object is an ATA device
1477  *
1478  * If an acpi object has one of the ACPI ATA methods defined,
1479  * then we can safely call it an ATA device.
1480  */
1481 bool acpi_ata_match(acpi_handle handle)
1482 {
1483         return acpi_has_method(handle, "_GTF") ||
1484                acpi_has_method(handle, "_GTM") ||
1485                acpi_has_method(handle, "_STM") ||
1486                acpi_has_method(handle, "_SDD");
1487 }
1488
1489 /*
1490  * acpi_bay_match - see if an acpi object is an ejectable driver bay
1491  *
1492  * If an acpi object is ejectable and has one of the ACPI ATA methods defined,
1493  * then we can safely call it an ejectable drive bay
1494  */
1495 bool acpi_bay_match(acpi_handle handle)
1496 {
1497         acpi_handle phandle;
1498
1499         if (!acpi_has_method(handle, "_EJ0"))
1500                 return false;
1501         if (acpi_ata_match(handle))
1502                 return true;
1503         if (ACPI_FAILURE(acpi_get_parent(handle, &phandle)))
1504                 return false;
1505
1506         return acpi_ata_match(phandle);
1507 }
1508
1509 /*
1510  * acpi_dock_match - see if an acpi object has a _DCK method
1511  */
1512 bool acpi_dock_match(acpi_handle handle)
1513 {
1514         return acpi_has_method(handle, "_DCK");
1515 }
1516
1517 const char *acpi_device_hid(struct acpi_device *device)
1518 {
1519         struct acpi_hardware_id *hid;
1520
1521         if (list_empty(&device->pnp.ids))
1522                 return dummy_hid;
1523
1524         hid = list_first_entry(&device->pnp.ids, struct acpi_hardware_id, list);
1525         return hid->id;
1526 }
1527 EXPORT_SYMBOL(acpi_device_hid);
1528
1529 static void acpi_add_id(struct acpi_device_pnp *pnp, const char *dev_id)
1530 {
1531         struct acpi_hardware_id *id;
1532
1533         id = kmalloc(sizeof(*id), GFP_KERNEL);
1534         if (!id)
1535                 return;
1536
1537         id->id = kstrdup(dev_id, GFP_KERNEL);
1538         if (!id->id) {
1539                 kfree(id);
1540                 return;
1541         }
1542
1543         list_add_tail(&id->list, &pnp->ids);
1544         pnp->type.hardware_id = 1;
1545 }
1546
1547 /*
1548  * Old IBM workstations have a DSDT bug wherein the SMBus object
1549  * lacks the SMBUS01 HID and the methods do not have the necessary "_"
1550  * prefix.  Work around this.
1551  */
1552 static bool acpi_ibm_smbus_match(acpi_handle handle)
1553 {
1554         char node_name[ACPI_PATH_SEGMENT_LENGTH];
1555         struct acpi_buffer path = { sizeof(node_name), node_name };
1556
1557         if (!dmi_name_in_vendors("IBM"))
1558                 return false;
1559
1560         /* Look for SMBS object */
1561         if (ACPI_FAILURE(acpi_get_name(handle, ACPI_SINGLE_NAME, &path)) ||
1562             strcmp("SMBS", path.pointer))
1563                 return false;
1564
1565         /* Does it have the necessary (but misnamed) methods? */
1566         if (acpi_has_method(handle, "SBI") &&
1567             acpi_has_method(handle, "SBR") &&
1568             acpi_has_method(handle, "SBW"))
1569                 return true;
1570
1571         return false;
1572 }
1573
1574 static void acpi_set_pnp_ids(acpi_handle handle, struct acpi_device_pnp *pnp,
1575                                 int device_type)
1576 {
1577         acpi_status status;
1578         struct acpi_device_info *info;
1579         struct acpi_pnp_device_id_list *cid_list;
1580         int i;
1581
1582         switch (device_type) {
1583         case ACPI_BUS_TYPE_DEVICE:
1584                 if (handle == ACPI_ROOT_OBJECT) {
1585                         acpi_add_id(pnp, ACPI_SYSTEM_HID);
1586                         break;
1587                 }
1588
1589                 status = acpi_get_object_info(handle, &info);
1590                 if (ACPI_FAILURE(status)) {
1591                         pr_err(PREFIX "%s: Error reading device info\n",
1592                                         __func__);
1593                         return;
1594                 }
1595
1596                 if (info->valid & ACPI_VALID_HID)
1597                         acpi_add_id(pnp, info->hardware_id.string);
1598                 if (info->valid & ACPI_VALID_CID) {
1599                         cid_list = &info->compatible_id_list;
1600                         for (i = 0; i < cid_list->count; i++)
1601                                 acpi_add_id(pnp, cid_list->ids[i].string);
1602                 }
1603                 if (info->valid & ACPI_VALID_ADR) {
1604                         pnp->bus_address = info->address;
1605                         pnp->type.bus_address = 1;
1606                 }
1607                 if (info->valid & ACPI_VALID_UID)
1608                         pnp->unique_id = kstrdup(info->unique_id.string,
1609                                                         GFP_KERNEL);
1610
1611                 kfree(info);
1612
1613                 /*
1614                  * Some devices don't reliably have _HIDs & _CIDs, so add
1615                  * synthetic HIDs to make sure drivers can find them.
1616                  */
1617                 if (acpi_is_video_device(handle))
1618                         acpi_add_id(pnp, ACPI_VIDEO_HID);
1619                 else if (acpi_bay_match(handle))
1620                         acpi_add_id(pnp, ACPI_BAY_HID);
1621                 else if (acpi_dock_match(handle))
1622                         acpi_add_id(pnp, ACPI_DOCK_HID);
1623                 else if (acpi_ibm_smbus_match(handle))
1624                         acpi_add_id(pnp, ACPI_SMBUS_IBM_HID);
1625                 else if (list_empty(&pnp->ids) && handle == ACPI_ROOT_OBJECT) {
1626                         acpi_add_id(pnp, ACPI_BUS_HID); /* \_SB, LNXSYBUS */
1627                         strcpy(pnp->device_name, ACPI_BUS_DEVICE_NAME);
1628                         strcpy(pnp->device_class, ACPI_BUS_CLASS);
1629                 }
1630
1631                 break;
1632         case ACPI_BUS_TYPE_POWER:
1633                 acpi_add_id(pnp, ACPI_POWER_HID);
1634                 break;
1635         case ACPI_BUS_TYPE_PROCESSOR:
1636                 acpi_add_id(pnp, ACPI_PROCESSOR_OBJECT_HID);
1637                 break;
1638         case ACPI_BUS_TYPE_THERMAL:
1639                 acpi_add_id(pnp, ACPI_THERMAL_HID);
1640                 break;
1641         case ACPI_BUS_TYPE_POWER_BUTTON:
1642                 acpi_add_id(pnp, ACPI_BUTTON_HID_POWERF);
1643                 break;
1644         case ACPI_BUS_TYPE_SLEEP_BUTTON:
1645                 acpi_add_id(pnp, ACPI_BUTTON_HID_SLEEPF);
1646                 break;
1647         }
1648 }
1649
1650 void acpi_free_pnp_ids(struct acpi_device_pnp *pnp)
1651 {
1652         struct acpi_hardware_id *id, *tmp;
1653
1654         list_for_each_entry_safe(id, tmp, &pnp->ids, list) {
1655                 kfree(id->id);
1656                 kfree(id);
1657         }
1658         kfree(pnp->unique_id);
1659 }
1660
1661 void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,
1662                              int type, unsigned long long sta)
1663 {
1664         INIT_LIST_HEAD(&device->pnp.ids);
1665         device->device_type = type;
1666         device->handle = handle;
1667         device->parent = acpi_bus_get_parent(handle);
1668         STRUCT_TO_INT(device->status) = sta;
1669         acpi_device_get_busid(device);
1670         acpi_set_pnp_ids(handle, &device->pnp, type);
1671         acpi_bus_get_flags(device);
1672         device->flags.match_driver = false;
1673         device_initialize(&device->dev);
1674         dev_set_uevent_suppress(&device->dev, true);
1675 }
1676
1677 void acpi_device_add_finalize(struct acpi_device *device)
1678 {
1679         device->flags.match_driver = true;
1680         dev_set_uevent_suppress(&device->dev, false);
1681         kobject_uevent(&device->dev.kobj, KOBJ_ADD);
1682 }
1683
1684 static int acpi_add_single_object(struct acpi_device **child,
1685                                   acpi_handle handle, int type,
1686                                   unsigned long long sta)
1687 {
1688         int result;
1689         struct acpi_device *device;
1690         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1691
1692         device = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
1693         if (!device) {
1694                 printk(KERN_ERR PREFIX "Memory allocation error\n");
1695                 return -ENOMEM;
1696         }
1697
1698         acpi_init_device_object(device, handle, type, sta);
1699         acpi_bus_get_power_flags(device);
1700         acpi_bus_get_wakeup_device_flags(device);
1701
1702         result = acpi_device_add(device, acpi_device_release);
1703         if (result) {
1704                 acpi_device_release(&device->dev);
1705                 return result;
1706         }
1707
1708         acpi_power_add_remove_device(device, true);
1709         acpi_device_add_finalize(device);
1710         acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
1711         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Added %s [%s] parent %s\n",
1712                 dev_name(&device->dev), (char *) buffer.pointer,
1713                 device->parent ? dev_name(&device->parent->dev) : "(null)"));
1714         kfree(buffer.pointer);
1715         *child = device;
1716         return 0;
1717 }
1718
1719 static int acpi_bus_type_and_status(acpi_handle handle, int *type,
1720                                     unsigned long long *sta)
1721 {
1722         acpi_status status;
1723         acpi_object_type acpi_type;
1724
1725         status = acpi_get_type(handle, &acpi_type);
1726         if (ACPI_FAILURE(status))
1727                 return -ENODEV;
1728
1729         switch (acpi_type) {
1730         case ACPI_TYPE_ANY:             /* for ACPI_ROOT_OBJECT */
1731         case ACPI_TYPE_DEVICE:
1732                 *type = ACPI_BUS_TYPE_DEVICE;
1733                 status = acpi_bus_get_status_handle(handle, sta);
1734                 if (ACPI_FAILURE(status))
1735                         return -ENODEV;
1736                 break;
1737         case ACPI_TYPE_PROCESSOR:
1738                 *type = ACPI_BUS_TYPE_PROCESSOR;
1739                 status = acpi_bus_get_status_handle(handle, sta);
1740                 if (ACPI_FAILURE(status))
1741                         return -ENODEV;
1742                 break;
1743         case ACPI_TYPE_THERMAL:
1744                 *type = ACPI_BUS_TYPE_THERMAL;
1745                 *sta = ACPI_STA_DEFAULT;
1746                 break;
1747         case ACPI_TYPE_POWER:
1748                 *type = ACPI_BUS_TYPE_POWER;
1749                 *sta = ACPI_STA_DEFAULT;
1750                 break;
1751         default:
1752                 return -ENODEV;
1753         }
1754
1755         return 0;
1756 }
1757
1758 static bool acpi_scan_handler_matching(struct acpi_scan_handler *handler,
1759                                        char *idstr,
1760                                        const struct acpi_device_id **matchid)
1761 {
1762         const struct acpi_device_id *devid;
1763
1764         for (devid = handler->ids; devid->id[0]; devid++)
1765                 if (!strcmp((char *)devid->id, idstr)) {
1766                         if (matchid)
1767                                 *matchid = devid;
1768
1769                         return true;
1770                 }
1771
1772         return false;
1773 }
1774
1775 static struct acpi_scan_handler *acpi_scan_match_handler(char *idstr,
1776                                         const struct acpi_device_id **matchid)
1777 {
1778         struct acpi_scan_handler *handler;
1779
1780         list_for_each_entry(handler, &acpi_scan_handlers_list, list_node)
1781                 if (acpi_scan_handler_matching(handler, idstr, matchid))
1782                         return handler;
1783
1784         return NULL;
1785 }
1786
1787 void acpi_scan_hotplug_enabled(struct acpi_hotplug_profile *hotplug, bool val)
1788 {
1789         if (!!hotplug->enabled == !!val)
1790                 return;
1791
1792         mutex_lock(&acpi_scan_lock);
1793
1794         hotplug->enabled = val;
1795
1796         mutex_unlock(&acpi_scan_lock);
1797 }
1798
1799 static void acpi_scan_init_hotplug(acpi_handle handle, int type)
1800 {
1801         struct acpi_device_pnp pnp = {};
1802         struct acpi_hardware_id *hwid;
1803         struct acpi_scan_handler *handler;
1804
1805         INIT_LIST_HEAD(&pnp.ids);
1806         acpi_set_pnp_ids(handle, &pnp, type);
1807
1808         if (!pnp.type.hardware_id)
1809                 goto out;
1810
1811         /*
1812          * This relies on the fact that acpi_install_notify_handler() will not
1813          * install the same notify handler routine twice for the same handle.
1814          */
1815         list_for_each_entry(hwid, &pnp.ids, list) {
1816                 handler = acpi_scan_match_handler(hwid->id, NULL);
1817                 if (handler) {
1818                         acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
1819                                         acpi_hotplug_notify_cb, handler);
1820                         break;
1821                 }
1822         }
1823
1824 out:
1825         acpi_free_pnp_ids(&pnp);
1826 }
1827
1828 static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl_not_used,
1829                                       void *not_used, void **return_value)
1830 {
1831         struct acpi_device *device = NULL;
1832         int type;
1833         unsigned long long sta;
1834         int result;
1835
1836         acpi_bus_get_device(handle, &device);
1837         if (device)
1838                 goto out;
1839
1840         result = acpi_bus_type_and_status(handle, &type, &sta);
1841         if (result)
1842                 return AE_OK;
1843
1844         if (type == ACPI_BUS_TYPE_POWER) {
1845                 acpi_add_power_resource(handle);
1846                 return AE_OK;
1847         }
1848
1849         acpi_scan_init_hotplug(handle, type);
1850
1851         if (!(sta & ACPI_STA_DEVICE_PRESENT) &&
1852             !(sta & ACPI_STA_DEVICE_FUNCTIONING)) {
1853                 struct acpi_device_wakeup wakeup;
1854
1855                 if (acpi_has_method(handle, "_PRW")) {
1856                         acpi_bus_extract_wakeup_device_power_package(handle,
1857                                                                      &wakeup);
1858                         acpi_power_resources_list_free(&wakeup.resources);
1859                 }
1860                 return AE_CTRL_DEPTH;
1861         }
1862
1863         acpi_add_single_object(&device, handle, type, sta);
1864         if (!device)
1865                 return AE_CTRL_DEPTH;
1866
1867  out:
1868         if (!*return_value)
1869                 *return_value = device;
1870
1871         return AE_OK;
1872 }
1873
1874 static int acpi_scan_attach_handler(struct acpi_device *device)
1875 {
1876         struct acpi_hardware_id *hwid;
1877         int ret = 0;
1878
1879         list_for_each_entry(hwid, &device->pnp.ids, list) {
1880                 const struct acpi_device_id *devid;
1881                 struct acpi_scan_handler *handler;
1882
1883                 handler = acpi_scan_match_handler(hwid->id, &devid);
1884                 if (handler) {
1885                         ret = handler->attach(device, devid);
1886                         if (ret > 0) {
1887                                 device->handler = handler;
1888                                 break;
1889                         } else if (ret < 0) {
1890                                 break;
1891                         }
1892                 }
1893         }
1894         return ret;
1895 }
1896
1897 static acpi_status acpi_bus_device_attach(acpi_handle handle, u32 lvl_not_used,
1898                                           void *not_used, void **ret_not_used)
1899 {
1900         struct acpi_device *device;
1901         unsigned long long sta_not_used;
1902         int ret;
1903
1904         /*
1905          * Ignore errors ignored by acpi_bus_check_add() to avoid terminating
1906          * namespace walks prematurely.
1907          */
1908         if (acpi_bus_type_and_status(handle, &ret, &sta_not_used))
1909                 return AE_OK;
1910
1911         if (acpi_bus_get_device(handle, &device))
1912                 return AE_CTRL_DEPTH;
1913
1914         if (device->handler)
1915                 return AE_OK;
1916
1917         ret = acpi_scan_attach_handler(device);
1918         if (ret)
1919                 return ret > 0 ? AE_OK : AE_CTRL_DEPTH;
1920
1921         ret = device_attach(&device->dev);
1922         return ret >= 0 ? AE_OK : AE_CTRL_DEPTH;
1923 }
1924
1925 /**
1926  * acpi_bus_scan - Add ACPI device node objects in a given namespace scope.
1927  * @handle: Root of the namespace scope to scan.
1928  *
1929  * Scan a given ACPI tree (probably recently hot-plugged) and create and add
1930  * found devices.
1931  *
1932  * If no devices were found, -ENODEV is returned, but it does not mean that
1933  * there has been a real error.  There just have been no suitable ACPI objects
1934  * in the table trunk from which the kernel could create a device and add an
1935  * appropriate driver.
1936  *
1937  * Must be called under acpi_scan_lock.
1938  */
1939 int acpi_bus_scan(acpi_handle handle)
1940 {
1941         void *device = NULL;
1942         int error = 0;
1943
1944         if (ACPI_SUCCESS(acpi_bus_check_add(handle, 0, NULL, &device)))
1945                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
1946                                     acpi_bus_check_add, NULL, NULL, &device);
1947
1948         if (!device)
1949                 error = -ENODEV;
1950         else if (ACPI_SUCCESS(acpi_bus_device_attach(handle, 0, NULL, NULL)))
1951                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
1952                                     acpi_bus_device_attach, NULL, NULL, NULL);
1953
1954         return error;
1955 }
1956 EXPORT_SYMBOL(acpi_bus_scan);
1957
1958 static acpi_status acpi_bus_device_detach(acpi_handle handle, u32 lvl_not_used,
1959                                           void *not_used, void **ret_not_used)
1960 {
1961         struct acpi_device *device = NULL;
1962
1963         if (!acpi_bus_get_device(handle, &device)) {
1964                 struct acpi_scan_handler *dev_handler = device->handler;
1965
1966                 if (dev_handler) {
1967                         if (dev_handler->detach)
1968                                 dev_handler->detach(device);
1969
1970                         device->handler = NULL;
1971                 } else {
1972                         device_release_driver(&device->dev);
1973                 }
1974         }
1975         return AE_OK;
1976 }
1977
1978 static acpi_status acpi_bus_remove(acpi_handle handle, u32 lvl_not_used,
1979                                    void *not_used, void **ret_not_used)
1980 {
1981         struct acpi_device *device = NULL;
1982
1983         if (!acpi_bus_get_device(handle, &device))
1984                 acpi_device_unregister(device);
1985
1986         return AE_OK;
1987 }
1988
1989 /**
1990  * acpi_bus_trim - Remove ACPI device node and all of its descendants
1991  * @start: Root of the ACPI device nodes subtree to remove.
1992  *
1993  * Must be called under acpi_scan_lock.
1994  */
1995 void acpi_bus_trim(struct acpi_device *start)
1996 {
1997         /*
1998          * Execute acpi_bus_device_detach() as a post-order callback to detach
1999          * all ACPI drivers from the device nodes being removed.
2000          */
2001         acpi_walk_namespace(ACPI_TYPE_ANY, start->handle, ACPI_UINT32_MAX, NULL,
2002                             acpi_bus_device_detach, NULL, NULL);
2003         acpi_bus_device_detach(start->handle, 0, NULL, NULL);
2004         /*
2005          * Execute acpi_bus_remove() as a post-order callback to remove device
2006          * nodes in the given namespace scope.
2007          */
2008         acpi_walk_namespace(ACPI_TYPE_ANY, start->handle, ACPI_UINT32_MAX, NULL,
2009                             acpi_bus_remove, NULL, NULL);
2010         acpi_bus_remove(start->handle, 0, NULL, NULL);
2011 }
2012 EXPORT_SYMBOL_GPL(acpi_bus_trim);
2013
2014 static int acpi_bus_scan_fixed(void)
2015 {
2016         int result = 0;
2017
2018         /*
2019          * Enumerate all fixed-feature devices.
2020          */
2021         if (!(acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON)) {
2022                 struct acpi_device *device = NULL;
2023
2024                 result = acpi_add_single_object(&device, NULL,
2025                                                 ACPI_BUS_TYPE_POWER_BUTTON,
2026                                                 ACPI_STA_DEFAULT);
2027                 if (result)
2028                         return result;
2029
2030                 result = device_attach(&device->dev);
2031                 if (result < 0)
2032                         return result;
2033
2034                 device_init_wakeup(&device->dev, true);
2035         }
2036
2037         if (!(acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON)) {
2038                 struct acpi_device *device = NULL;
2039
2040                 result = acpi_add_single_object(&device, NULL,
2041                                                 ACPI_BUS_TYPE_SLEEP_BUTTON,
2042                                                 ACPI_STA_DEFAULT);
2043                 if (result)
2044                         return result;
2045
2046                 result = device_attach(&device->dev);
2047         }
2048
2049         return result < 0 ? result : 0;
2050 }
2051
2052 int __init acpi_scan_init(void)
2053 {
2054         int result;
2055
2056         result = bus_register(&acpi_bus_type);
2057         if (result) {
2058                 /* We don't want to quit even if we failed to add suspend/resume */
2059                 printk(KERN_ERR PREFIX "Could not register bus type\n");
2060         }
2061
2062         acpi_pci_root_init();
2063         acpi_pci_link_init();
2064         acpi_processor_init();
2065         acpi_platform_init();
2066         acpi_lpss_init();
2067         acpi_cmos_rtc_init();
2068         acpi_container_init();
2069         acpi_memory_hotplug_init();
2070         acpi_dock_init();
2071
2072         mutex_lock(&acpi_scan_lock);
2073         /*
2074          * Enumerate devices in the ACPI namespace.
2075          */
2076         result = acpi_bus_scan(ACPI_ROOT_OBJECT);
2077         if (result)
2078                 goto out;
2079
2080         result = acpi_bus_get_device(ACPI_ROOT_OBJECT, &acpi_root);
2081         if (result)
2082                 goto out;
2083
2084         result = acpi_bus_scan_fixed();
2085         if (result) {
2086                 acpi_device_unregister(acpi_root);
2087                 goto out;
2088         }
2089
2090         acpi_update_all_gpes();
2091
2092         acpi_pci_root_hp_init();
2093
2094  out:
2095         mutex_unlock(&acpi_scan_lock);
2096         return result;
2097 }