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 static const char *dummy_hid = "device";
  31
  32 static LIST_HEAD(acpi_device_list);
  33 static LIST_HEAD(acpi_bus_id_list);
  34 static DEFINE_MUTEX(acpi_scan_lock);
  35 static LIST_HEAD(acpi_scan_handlers_list);
  36 DEFINE_MUTEX(acpi_device_lock);
  37 LIST_HEAD(acpi_wakeup_device_list);
  38
  39 struct acpi_device_bus_id{
  40         char bus_id[15];
  41         unsigned int instance_no;
  42         struct list_head node;
  43 };
  44
  45 void acpi_scan_lock_acquire(void)
  46 {
  47         mutex_lock(&acpi_scan_lock);
  48 }
  49 EXPORT_SYMBOL_GPL(acpi_scan_lock_acquire);
  50
  51 void acpi_scan_lock_release(void)
  52 {
  53         mutex_unlock(&acpi_scan_lock);
  54 }
  55 EXPORT_SYMBOL_GPL(acpi_scan_lock_release);
  56
  57 int acpi_scan_add_handler(struct acpi_scan_handler *handler)
  58 {
  59         if (!handler || !handler->attach)
  60                 return -EINVAL;
  61
  62         list_add_tail(&handler->list_node, &acpi_scan_handlers_list);
  63         return 0;
  64 }
  65
  66 int acpi_scan_add_handler_with_hotplug(struct acpi_scan_handler *handler,
  67                                        const char *hotplug_profile_name)
  68 {
  69         int error;
  70
  71         error = acpi_scan_add_handler(handler);
  72         if (error)
  73                 return error;
  74
  75         acpi_sysfs_add_hotplug_profile(&handler->hotplug, hotplug_profile_name);
  76         return 0;
  77 }
  78
  79 /*
  80  * Creates hid/cid(s) string needed for modalias and uevent
  81  * e.g. on a device with hid:IBM0001 and cid:ACPI0001 you get:
  82  * char *modalias: "acpi:IBM0001:ACPI0001"
  83 */
  84 static int create_modalias(struct acpi_device *acpi_dev, char *modalias,
  85                            int size)
  86 {
  87         int len;
  88         int count;
  89         struct acpi_hardware_id *id;
  90
  91         if (list_empty(&acpi_dev->pnp.ids))
  92                 return 0;
  93
  94         len = snprintf(modalias, size, "acpi:");
  95         size -= len;
  96
  97         list_for_each_entry(id, &acpi_dev->pnp.ids, list) {
  98                 count = snprintf(&modalias[len], size, "%s:", id->id);
  99                 if (count < 0 || count >= size)
 100                         return -EINVAL;
 101                 len += count;
 102                 size -= count;
 103         }
 104
 105         modalias[len] = '\0';
 106         return len;
 107 }
 108
 109 static ssize_t
 110 acpi_device_modalias_show(struct device *dev, struct device_attribute *attr, char *buf) {
 111         struct acpi_device *acpi_dev = to_acpi_device(dev);
 112         int len;
 113
 114         /* Device has no HID and no CID or string is >1024 */
 115         len = create_modalias(acpi_dev, buf, 1024);
 116         if (len <= 0)
 117                 return 0;
 118         buf[len++] = '\n';
 119         return len;
 120 }
 121 static DEVICE_ATTR(modalias, 0444, acpi_device_modalias_show, NULL);
 122
 123 static int acpi_scan_hot_remove(struct acpi_device *device)
 124 {
 125         acpi_handle handle = device->handle;
 126         acpi_handle not_used;
 127         struct acpi_object_list arg_list;
 128         union acpi_object arg;
 129         acpi_status status;
 130
 131         /* If there is no handle, the device node has been unregistered. */
 132         if (!handle) {
 133                 dev_dbg(&device->dev, "ACPI handle missing\n");
 134                 put_device(&device->dev);
 135                 return -EINVAL;
 136         }
 137
 138         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 139                 "Hot-removing device %s...\n", dev_name(&device->dev)));
 140
 141         acpi_bus_trim(device);
 142         /* Device node has been unregistered. */
 143         put_device(&device->dev);
 144         device = NULL;
 145
 146         if (ACPI_SUCCESS(acpi_get_handle(handle, "_LCK", &not_used))) {
 147                 arg_list.count = 1;
 148                 arg_list.pointer = &arg;
 149                 arg.type = ACPI_TYPE_INTEGER;
 150                 arg.integer.value = 0;
 151                 acpi_evaluate_object(handle, "_LCK", &arg_list, NULL);
 152         }
 153
 154         arg_list.count = 1;
 155         arg_list.pointer = &arg;
 156         arg.type = ACPI_TYPE_INTEGER;
 157         arg.integer.value = 1;
 158
 159         /*
 160          * TBD: _EJD support.
 161          */
 162         status = acpi_evaluate_object(handle, "_EJ0", &arg_list, NULL);
 163         if (ACPI_FAILURE(status)) {
 164                 if (status == AE_NOT_FOUND) {
 165                         return -ENODEV;
 166                 } else {
 167                         acpi_handle_warn(handle, "Eject failed\n");
 168                         return -EIO;
 169                 }
 170         }
 171         return 0;
 172 }
 173
 174 static void acpi_bus_device_eject(void *context)
 175 {
 176         acpi_handle handle = context;
 177         struct acpi_device *device = NULL;
 178         struct acpi_scan_handler *handler;
 179         u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
 180
 181         mutex_lock(&acpi_scan_lock);
 182
 183         acpi_bus_get_device(handle, &device);
 184         if (!device)
 185                 goto err_out;
 186
 187         handler = device->handler;
 188         if (!handler || !handler->hotplug.enabled) {
 189                 ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
 190                 goto err_out;
 191         }
 192         acpi_evaluate_hotplug_ost(handle, ACPI_NOTIFY_EJECT_REQUEST,
 193                                   ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
 194         if (handler->hotplug.mode == AHM_CONTAINER) {
 195                 device->flags.eject_pending = true;
 196                 kobject_uevent(&device->dev.kobj, KOBJ_OFFLINE);
 197         } else {
 198                 int error;
 199
 200                 get_device(&device->dev);
 201                 error = acpi_scan_hot_remove(device);
 202                 if (error)
 203                         goto err_out;
 204         }
 205
 206  out:
 207         mutex_unlock(&acpi_scan_lock);
 208         return;
 209
 210  err_out:
 211         acpi_evaluate_hotplug_ost(handle, ACPI_NOTIFY_EJECT_REQUEST, ost_code,
 212                                   NULL);
 213         goto out;
 214 }
 215
 216 static void acpi_scan_bus_device_check(acpi_handle handle, u32 ost_source)
 217 {
 218         struct acpi_device *device = NULL;
 219         u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
 220         int error;
 221
 222         mutex_lock(&acpi_scan_lock);
 223
 224         acpi_bus_get_device(handle, &device);
 225         if (device) {
 226                 dev_warn(&device->dev, "Attempt to re-insert\n");
 227                 goto out;
 228         }
 229         acpi_evaluate_hotplug_ost(handle, ost_source,
 230                                   ACPI_OST_SC_INSERT_IN_PROGRESS, NULL);
 231         error = acpi_bus_scan(handle);
 232         if (error) {
 233                 acpi_handle_warn(handle, "Namespace scan failure\n");
 234                 goto out;
 235         }
 236         error = acpi_bus_get_device(handle, &device);
 237         if (error) {
 238                 acpi_handle_warn(handle, "Missing device node object\n");
 239                 goto out;
 240         }
 241         ost_code = ACPI_OST_SC_SUCCESS;
 242         if (device->handler && device->handler->hotplug.mode == AHM_CONTAINER)
 243                 kobject_uevent(&device->dev.kobj, KOBJ_ONLINE);
 244
 245  out:
 246         acpi_evaluate_hotplug_ost(handle, ost_source, ost_code, NULL);
 247         mutex_unlock(&acpi_scan_lock);
 248 }
 249
 250 static void acpi_scan_bus_check(void *context)
 251 {
 252         acpi_scan_bus_device_check((acpi_handle)context,
 253                                    ACPI_NOTIFY_BUS_CHECK);
 254 }
 255
 256 static void acpi_scan_device_check(void *context)
 257 {
 258         acpi_scan_bus_device_check((acpi_handle)context,
 259                                    ACPI_NOTIFY_DEVICE_CHECK);
 260 }
 261
 262 static void acpi_hotplug_notify_cb(acpi_handle handle, u32 type, void *not_used)
 263 {
 264         acpi_osd_exec_callback callback;
 265         acpi_status status;
 266
 267         switch (type) {
 268         case ACPI_NOTIFY_BUS_CHECK:
 269                 acpi_handle_debug(handle, "ACPI_NOTIFY_BUS_CHECK event\n");
 270                 callback = acpi_scan_bus_check;
 271                 break;
 272         case ACPI_NOTIFY_DEVICE_CHECK:
 273                 acpi_handle_debug(handle, "ACPI_NOTIFY_DEVICE_CHECK event\n");
 274                 callback = acpi_scan_device_check;
 275                 break;
 276         case ACPI_NOTIFY_EJECT_REQUEST:
 277                 acpi_handle_debug(handle, "ACPI_NOTIFY_EJECT_REQUEST event\n");
 278                 callback = acpi_bus_device_eject;
 279                 break;
 280         default:
 281                 /* non-hotplug event; possibly handled by other handler */
 282                 return;
 283         }
 284         status = acpi_os_hotplug_execute(callback, handle);
 285         if (ACPI_FAILURE(status))
 286                 acpi_evaluate_hotplug_ost(handle, type,
 287                                           ACPI_OST_SC_NON_SPECIFIC_FAILURE,
 288                                           NULL);
 289 }
 290
 291 /**
 292  * acpi_bus_hot_remove_device: hot-remove a device and its children
 293  * @context: struct acpi_eject_event pointer (freed in this func)
 294  *
 295  * Hot-remove a device and its children. This function frees up the
 296  * memory space passed by arg context, so that the caller may call
 297  * this function asynchronously through acpi_os_hotplug_execute().
 298  */
 299 void acpi_bus_hot_remove_device(void *context)
 300 {
 301         struct acpi_eject_event *ej_event = context;
 302         struct acpi_device *device = ej_event->device;
 303         acpi_handle handle = device->handle;
 304         int error;
 305
 306         mutex_lock(&acpi_scan_lock);
 307
 308         error = acpi_scan_hot_remove(device);
 309         if (error && handle)
 310                 acpi_evaluate_hotplug_ost(handle, ej_event->event,
 311                                           ACPI_OST_SC_NON_SPECIFIC_FAILURE,
 312                                           NULL);
 313
 314         mutex_unlock(&acpi_scan_lock);
 315         kfree(context);
 316 }
 317 EXPORT_SYMBOL(acpi_bus_hot_remove_device);
 318
 319 static ssize_t real_power_state_show(struct device *dev,
 320                                      struct device_attribute *attr, char *buf)
 321 {
 322         struct acpi_device *adev = to_acpi_device(dev);
 323         int state;
 324         int ret;
 325
 326         ret = acpi_device_get_power(adev, &state);
 327         if (ret)
 328                 return ret;
 329
 330         return sprintf(buf, "%s\n", acpi_power_state_string(state));
 331 }
 332
 333 static DEVICE_ATTR(real_power_state, 0444, real_power_state_show, NULL);
 334
 335 static ssize_t power_state_show(struct device *dev,
 336                                 struct device_attribute *attr, char *buf)
 337 {
 338         struct acpi_device *adev = to_acpi_device(dev);
 339
 340         return sprintf(buf, "%s\n", acpi_power_state_string(adev->power.state));
 341 }
 342
 343 static DEVICE_ATTR(power_state, 0444, power_state_show, NULL);
 344
 345 static ssize_t
 346 acpi_eject_store(struct device *d, struct device_attribute *attr,
 347                 const char *buf, size_t count)
 348 {
 349         struct acpi_device *acpi_device = to_acpi_device(d);
 350         struct acpi_eject_event *ej_event;
 351         acpi_object_type not_used;
 352         acpi_status status;
 353         u32 ost_source;
 354         int ret;
 355
 356         if (!count || buf[0] != '1')
 357                 return -EINVAL;
 358
 359         if ((!acpi_device->handler || !acpi_device->handler->hotplug.enabled)
 360             && !acpi_device->driver)
 361                 return -ENODEV;
 362
 363         status = acpi_get_type(acpi_device->handle, &not_used);
 364         if (ACPI_FAILURE(status) || !acpi_device->flags.ejectable)
 365                 return -ENODEV;
 366
 367         mutex_lock(&acpi_scan_lock);
 368
 369         if (acpi_device->flags.eject_pending) {
 370                 /* ACPI eject notification event. */
 371                 ost_source = ACPI_NOTIFY_EJECT_REQUEST;
 372                 acpi_device->flags.eject_pending = 0;
 373         } else {
 374                 /* Eject initiated by user space. */
 375                 ost_source = ACPI_OST_EC_OSPM_EJECT;
 376         }
 377         ej_event = kmalloc(sizeof(*ej_event), GFP_KERNEL);
 378         if (!ej_event) {
 379                 ret = -ENOMEM;
 380                 goto err_out;
 381         }
 382         acpi_evaluate_hotplug_ost(acpi_device->handle, ost_source,
 383                                   ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
 384         ej_event->device = acpi_device;
 385         ej_event->event = ost_source;
 386         get_device(&acpi_device->dev);
 387         status = acpi_os_hotplug_execute(acpi_bus_hot_remove_device, ej_event);
 388         if (ACPI_FAILURE(status)) {
 389                 put_device(&acpi_device->dev);
 390                 kfree(ej_event);
 391                 ret = status == AE_NO_MEMORY ? -ENOMEM : -EAGAIN;
 392                 goto err_out;
 393         }
 394         ret = count;
 395
 396  out:
 397         mutex_unlock(&acpi_scan_lock);
 398         return ret;
 399
 400  err_out:
 401         acpi_evaluate_hotplug_ost(acpi_device->handle, ost_source,
 402                                   ACPI_OST_SC_NON_SPECIFIC_FAILURE, NULL);
 403         goto out;
 404 }
 405
 406 static DEVICE_ATTR(eject, 0200, NULL, acpi_eject_store);
 407
 408 static ssize_t
 409 acpi_device_hid_show(struct device *dev, struct device_attribute *attr, char *buf) {
 410         struct acpi_device *acpi_dev = to_acpi_device(dev);
 411
 412         return sprintf(buf, "%s\n", acpi_device_hid(acpi_dev));
 413 }
 414 static DEVICE_ATTR(hid, 0444, acpi_device_hid_show, NULL);
 415
 416 static ssize_t acpi_device_uid_show(struct device *dev,
 417                                     struct device_attribute *attr, char *buf)
 418 {
 419         struct acpi_device *acpi_dev = to_acpi_device(dev);
 420
 421         return sprintf(buf, "%s\n", acpi_dev->pnp.unique_id);
 422 }
 423 static DEVICE_ATTR(uid, 0444, acpi_device_uid_show, NULL);
 424
 425 static ssize_t acpi_device_adr_show(struct device *dev,
 426                                     struct device_attribute *attr, char *buf)
 427 {
 428         struct acpi_device *acpi_dev = to_acpi_device(dev);
 429
 430         return sprintf(buf, "0x%08x\n",
 431                        (unsigned int)(acpi_dev->pnp.bus_address));
 432 }
 433 static DEVICE_ATTR(adr, 0444, acpi_device_adr_show, NULL);
 434
 435 static ssize_t
 436 acpi_device_path_show(struct device *dev, struct device_attribute *attr, char *buf) {
 437         struct acpi_device *acpi_dev = to_acpi_device(dev);
 438         struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
 439         int result;
 440
 441         result = acpi_get_name(acpi_dev->handle, ACPI_FULL_PATHNAME, &path);
 442         if (result)
 443                 goto end;
 444
 445         result = sprintf(buf, "%s\n", (char*)path.pointer);
 446         kfree(path.pointer);
 447 end:
 448         return result;
 449 }
 450 static DEVICE_ATTR(path, 0444, acpi_device_path_show, NULL);
 451
 452 /* sysfs file that shows description text from the ACPI _STR method */
 453 static ssize_t description_show(struct device *dev,
 454                                 struct device_attribute *attr,
 455                                 char *buf) {
 456         struct acpi_device *acpi_dev = to_acpi_device(dev);
 457         int result;
 458
 459         if (acpi_dev->pnp.str_obj == NULL)
 460                 return 0;
 461
 462         /*
 463          * The _STR object contains a Unicode identifier for a device.
 464          * We need to convert to utf-8 so it can be displayed.
 465          */
 466         result = utf16s_to_utf8s(
 467                 (wchar_t *)acpi_dev->pnp.str_obj->buffer.pointer,
 468                 acpi_dev->pnp.str_obj->buffer.length,
 469                 UTF16_LITTLE_ENDIAN, buf,
 470                 PAGE_SIZE);
 471
 472         buf[result++] = '\n';
 473
 474         return result;
 475 }
 476 static DEVICE_ATTR(description, 0444, description_show, NULL);
 477
 478 static ssize_t
 479 acpi_device_sun_show(struct device *dev, struct device_attribute *attr,
 480                      char *buf) {
 481         struct acpi_device *acpi_dev = to_acpi_device(dev);
 482
 483         return sprintf(buf, "%lu\n", acpi_dev->pnp.sun);
 484 }
 485 static DEVICE_ATTR(sun, 0444, acpi_device_sun_show, NULL);
 486
 487 static int acpi_device_setup_files(struct acpi_device *dev)
 488 {
 489         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
 490         acpi_status status;
 491         acpi_handle temp;
 492         unsigned long long sun;
 493         int result = 0;
 494
 495         /*
 496          * Devices gotten from FADT don't have a "path" attribute
 497          */
 498         if (dev->handle) {
 499                 result = device_create_file(&dev->dev, &dev_attr_path);
 500                 if (result)
 501                         goto end;
 502         }
 503
 504         if (!list_empty(&dev->pnp.ids)) {
 505                 result = device_create_file(&dev->dev, &dev_attr_hid);
 506                 if (result)
 507                         goto end;
 508
 509                 result = device_create_file(&dev->dev, &dev_attr_modalias);
 510                 if (result)
 511                         goto end;
 512         }
 513
 514         /*
 515          * If device has _STR, 'description' file is created
 516          */
 517         status = acpi_get_handle(dev->handle, "_STR", &temp);
 518         if (ACPI_SUCCESS(status)) {
 519                 status = acpi_evaluate_object(dev->handle, "_STR",
 520                                         NULL, &buffer);
 521                 if (ACPI_FAILURE(status))
 522                         buffer.pointer = NULL;
 523                 dev->pnp.str_obj = buffer.pointer;
 524                 result = device_create_file(&dev->dev, &dev_attr_description);
 525                 if (result)
 526                         goto end;
 527         }
 528
 529         if (dev->flags.bus_address)
 530                 result = device_create_file(&dev->dev, &dev_attr_adr);
 531         if (dev->pnp.unique_id)
 532                 result = device_create_file(&dev->dev, &dev_attr_uid);
 533
 534         status = acpi_evaluate_integer(dev->handle, "_SUN", NULL, &sun);
 535         if (ACPI_SUCCESS(status)) {
 536                 dev->pnp.sun = (unsigned long)sun;
 537                 result = device_create_file(&dev->dev, &dev_attr_sun);
 538                 if (result)
 539                         goto end;
 540         } else {
 541                 dev->pnp.sun = (unsigned long)-1;
 542         }
 543
 544         /*
 545          * If device has _EJ0, 'eject' file is created that is used to trigger
 546          * hot-removal function from userland.
 547          */
 548         status = acpi_get_handle(dev->handle, "_EJ0", &temp);
 549         if (ACPI_SUCCESS(status)) {
 550                 result = device_create_file(&dev->dev, &dev_attr_eject);
 551                 if (result)
 552                         return result;
 553         }
 554
 555         if (dev->flags.power_manageable) {
 556                 result = device_create_file(&dev->dev, &dev_attr_power_state);
 557                 if (result)
 558                         return result;
 559
 560                 if (dev->power.flags.power_resources)
 561                         result = device_create_file(&dev->dev,
 562                                                     &dev_attr_real_power_state);
 563         }
 564
 565 end:
 566         return result;
 567 }
 568
 569 static void acpi_device_remove_files(struct acpi_device *dev)
 570 {
 571         acpi_status status;
 572         acpi_handle temp;
 573
 574         if (dev->flags.power_manageable) {
 575                 device_remove_file(&dev->dev, &dev_attr_power_state);
 576                 if (dev->power.flags.power_resources)
 577                         device_remove_file(&dev->dev,
 578                                            &dev_attr_real_power_state);
 579         }
 580
 581         /*
 582          * If device has _STR, remove 'description' file
 583          */
 584         status = acpi_get_handle(dev->handle, "_STR", &temp);
 585         if (ACPI_SUCCESS(status)) {
 586                 kfree(dev->pnp.str_obj);
 587                 device_remove_file(&dev->dev, &dev_attr_description);
 588         }
 589         /*
 590          * If device has _EJ0, remove 'eject' file.
 591          */
 592         status = acpi_get_handle(dev->handle, "_EJ0", &temp);
 593         if (ACPI_SUCCESS(status))
 594                 device_remove_file(&dev->dev, &dev_attr_eject);
 595
 596         status = acpi_get_handle(dev->handle, "_SUN", &temp);
 597         if (ACPI_SUCCESS(status))
 598                 device_remove_file(&dev->dev, &dev_attr_sun);
 599
 600         if (dev->pnp.unique_id)
 601                 device_remove_file(&dev->dev, &dev_attr_uid);
 602         if (dev->flags.bus_address)
 603                 device_remove_file(&dev->dev, &dev_attr_adr);
 604         device_remove_file(&dev->dev, &dev_attr_modalias);
 605         device_remove_file(&dev->dev, &dev_attr_hid);
 606         if (dev->handle)
 607                 device_remove_file(&dev->dev, &dev_attr_path);
 608 }
 609 /* --------------------------------------------------------------------------
 610                         ACPI Bus operations
 611    -------------------------------------------------------------------------- */
 612
 613 static const struct acpi_device_id *__acpi_match_device(
 614         struct acpi_device *device, const struct acpi_device_id *ids)
 615 {
 616         const struct acpi_device_id *id;
 617         struct acpi_hardware_id *hwid;
 618
 619         /*
 620          * If the device is not present, it is unnecessary to load device
 621          * driver for it.
 622          */
 623         if (!device->status.present)
 624                 return NULL;
 625
 626         for (id = ids; id->id[0]; id++)
 627                 list_for_each_entry(hwid, &device->pnp.ids, list)
 628                         if (!strcmp((char *) id->id, hwid->id))
 629                                 return id;
 630
 631         return NULL;
 632 }
 633
 634 /**
 635  * acpi_match_device - Match a struct device against a given list of ACPI IDs
 636  * @ids: Array of struct acpi_device_id object to match against.
 637  * @dev: The device structure to match.
 638  *
 639  * Check if @dev has a valid ACPI handle and if there is a struct acpi_device
 640  * object for that handle and use that object to match against a given list of
 641  * device IDs.
 642  *
 643  * Return a pointer to the first matching ID on success or %NULL on failure.
 644  */
 645 const struct acpi_device_id *acpi_match_device(const struct acpi_device_id *ids,
 646                                                const struct device *dev)
 647 {
 648         struct acpi_device *adev;
 649         acpi_handle handle = ACPI_HANDLE(dev);
 650
 651         if (!ids || !handle || acpi_bus_get_device(handle, &adev))
 652                 return NULL;
 653
 654         return __acpi_match_device(adev, ids);
 655 }
 656 EXPORT_SYMBOL_GPL(acpi_match_device);
 657
 658 int acpi_match_device_ids(struct acpi_device *device,
 659                           const struct acpi_device_id *ids)
 660 {
 661         return __acpi_match_device(device, ids) ? 0 : -ENOENT;
 662 }
 663 EXPORT_SYMBOL(acpi_match_device_ids);
 664
 665 void acpi_free_ids(struct acpi_device *device)
 666 {
 667         struct acpi_hardware_id *id, *tmp;
 668
 669         list_for_each_entry_safe(id, tmp, &device->pnp.ids, list) {
 670                 kfree(id->id);
 671                 kfree(id);
 672         }
 673         kfree(device->pnp.unique_id);
 674 }
 675
 676 static void acpi_free_power_resources_lists(struct acpi_device *device)
 677 {
 678         int i;
 679
 680         if (device->wakeup.flags.valid)
 681                 acpi_power_resources_list_free(&device->wakeup.resources);
 682
 683         if (!device->flags.power_manageable)
 684                 return;
 685
 686         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
 687                 struct acpi_device_power_state *ps = &device->power.states[i];
 688                 acpi_power_resources_list_free(&ps->resources);
 689         }
 690 }
 691
 692 static void acpi_device_release(struct device *dev)
 693 {
 694         struct acpi_device *acpi_dev = to_acpi_device(dev);
 695
 696         acpi_free_ids(acpi_dev);
 697         acpi_free_power_resources_lists(acpi_dev);
 698         kfree(acpi_dev);
 699 }
 700
 701 static int acpi_bus_match(struct device *dev, struct device_driver *drv)
 702 {
 703         struct acpi_device *acpi_dev = to_acpi_device(dev);
 704         struct acpi_driver *acpi_drv = to_acpi_driver(drv);
 705
 706         return acpi_dev->flags.match_driver
 707                 && !acpi_match_device_ids(acpi_dev, acpi_drv->ids);
 708 }
 709
 710 static int acpi_device_uevent(struct device *dev, struct kobj_uevent_env *env)
 711 {
 712         struct acpi_device *acpi_dev = to_acpi_device(dev);
 713         int len;
 714
 715         if (list_empty(&acpi_dev->pnp.ids))
 716                 return 0;
 717
 718         if (add_uevent_var(env, "MODALIAS="))
 719                 return -ENOMEM;
 720         len = create_modalias(acpi_dev, &env->buf[env->buflen - 1],
 721                               sizeof(env->buf) - env->buflen);
 722         if (len >= (sizeof(env->buf) - env->buflen))
 723                 return -ENOMEM;
 724         env->buflen += len;
 725         return 0;
 726 }
 727
 728 static void acpi_device_notify(acpi_handle handle, u32 event, void *data)
 729 {
 730         struct acpi_device *device = data;
 731
 732         device->driver->ops.notify(device, event);
 733 }
 734
 735 static acpi_status acpi_device_notify_fixed(void *data)
 736 {
 737         struct acpi_device *device = data;
 738
 739         /* Fixed hardware devices have no handles */
 740         acpi_device_notify(NULL, ACPI_FIXED_HARDWARE_EVENT, device);
 741         return AE_OK;
 742 }
 743
 744 static int acpi_device_install_notify_handler(struct acpi_device *device)
 745 {
 746         acpi_status status;
 747
 748         if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
 749                 status =
 750                     acpi_install_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
 751                                                      acpi_device_notify_fixed,
 752                                                      device);
 753         else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
 754                 status =
 755                     acpi_install_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
 756                                                      acpi_device_notify_fixed,
 757                                                      device);
 758         else
 759                 status = acpi_install_notify_handler(device->handle,
 760                                                      ACPI_DEVICE_NOTIFY,
 761                                                      acpi_device_notify,
 762                                                      device);
 763
 764         if (ACPI_FAILURE(status))
 765                 return -EINVAL;
 766         return 0;
 767 }
 768
 769 static void acpi_device_remove_notify_handler(struct acpi_device *device)
 770 {
 771         if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
 772                 acpi_remove_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
 773                                                 acpi_device_notify_fixed);
 774         else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
 775                 acpi_remove_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
 776                                                 acpi_device_notify_fixed);
 777         else
 778                 acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
 779                                            acpi_device_notify);
 780 }
 781
 782 static int acpi_bus_driver_init(struct acpi_device *, struct acpi_driver *);
 783 static int acpi_device_probe(struct device * dev)
 784 {
 785         struct acpi_device *acpi_dev = to_acpi_device(dev);
 786         struct acpi_driver *acpi_drv = to_acpi_driver(dev->driver);
 787         int ret;
 788
 789         ret = acpi_bus_driver_init(acpi_dev, acpi_drv);
 790         if (!ret) {
 791                 if (acpi_drv->ops.notify) {
 792                         ret = acpi_device_install_notify_handler(acpi_dev);
 793                         if (ret) {
 794                                 if (acpi_drv->ops.remove)
 795                                         acpi_drv->ops.remove(acpi_dev);
 796                                 acpi_dev->driver = NULL;
 797                                 acpi_dev->driver_data = NULL;
 798                                 return ret;
 799                         }
 800                 }
 801
 802                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 803                         "Found driver [%s] for device [%s]\n",
 804                         acpi_drv->name, acpi_dev->pnp.bus_id));
 805                 get_device(dev);
 806         }
 807         return ret;
 808 }
 809
 810 static int acpi_device_remove(struct device * dev)
 811 {
 812         struct acpi_device *acpi_dev = to_acpi_device(dev);
 813         struct acpi_driver *acpi_drv = acpi_dev->driver;
 814
 815         if (acpi_drv) {
 816                 if (acpi_drv->ops.notify)
 817                         acpi_device_remove_notify_handler(acpi_dev);
 818                 if (acpi_drv->ops.remove)
 819                         acpi_drv->ops.remove(acpi_dev);
 820         }
 821         acpi_dev->driver = NULL;
 822         acpi_dev->driver_data = NULL;
 823
 824         put_device(dev);
 825         return 0;
 826 }
 827
 828 struct bus_type acpi_bus_type = {
 829         .name           = "acpi",
 830         .match          = acpi_bus_match,
 831         .probe          = acpi_device_probe,
 832         .remove         = acpi_device_remove,
 833         .uevent         = acpi_device_uevent,
 834 };
 835
 836 int acpi_device_add(struct acpi_device *device,
 837                     void (*release)(struct device *))
 838 {
 839         int result;
 840         struct acpi_device_bus_id *acpi_device_bus_id, *new_bus_id;
 841         int found = 0;
 842
 843         if (device->handle) {
 844                 acpi_status status;
 845
 846                 status = acpi_attach_data(device->handle, acpi_bus_data_handler,
 847                                           device);
 848                 if (ACPI_FAILURE(status)) {
 849                         acpi_handle_err(device->handle,
 850                                         "Unable to attach device data\n");
 851                         return -ENODEV;
 852                 }
 853         }
 854
 855         /*
 856          * Linkage
 857          * -------
 858          * Link this device to its parent and siblings.
 859          */
 860         INIT_LIST_HEAD(&device->children);
 861         INIT_LIST_HEAD(&device->node);
 862         INIT_LIST_HEAD(&device->wakeup_list);
 863         INIT_LIST_HEAD(&device->physical_node_list);
 864         mutex_init(&device->physical_node_lock);
 865         INIT_LIST_HEAD(&device->power_dependent);
 866
 867         new_bus_id = kzalloc(sizeof(struct acpi_device_bus_id), GFP_KERNEL);
 868         if (!new_bus_id) {
 869                 pr_err(PREFIX "Memory allocation error\n");
 870                 result = -ENOMEM;
 871                 goto err_detach;
 872         }
 873
 874         mutex_lock(&acpi_device_lock);
 875         /*
 876          * Find suitable bus_id and instance number in acpi_bus_id_list
 877          * If failed, create one and link it into acpi_bus_id_list
 878          */
 879         list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
 880                 if (!strcmp(acpi_device_bus_id->bus_id,
 881                             acpi_device_hid(device))) {
 882                         acpi_device_bus_id->instance_no++;
 883                         found = 1;
 884                         kfree(new_bus_id);
 885                         break;
 886                 }
 887         }
 888         if (!found) {
 889                 acpi_device_bus_id = new_bus_id;
 890                 strcpy(acpi_device_bus_id->bus_id, acpi_device_hid(device));
 891                 acpi_device_bus_id->instance_no = 0;
 892                 list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
 893         }
 894         dev_set_name(&device->dev, "%s:%02x", acpi_device_bus_id->bus_id, acpi_device_bus_id->instance_no);
 895
 896         if (device->parent)
 897                 list_add_tail(&device->node, &device->parent->children);
 898
 899         if (device->wakeup.flags.valid)
 900                 list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);
 901         mutex_unlock(&acpi_device_lock);
 902
 903         if (device->parent)
 904                 device->dev.parent = &device->parent->dev;
 905         device->dev.bus = &acpi_bus_type;
 906         device->dev.release = release;
 907         result = device_add(&device->dev);
 908         if (result) {
 909                 dev_err(&device->dev, "Error registering device\n");
 910                 goto err;
 911         }
 912
 913         result = acpi_device_setup_files(device);
 914         if (result)
 915                 printk(KERN_ERR PREFIX "Error creating sysfs interface for device %s\n",
 916                        dev_name(&device->dev));
 917
 918         device->removal_type = ACPI_BUS_REMOVAL_NORMAL;
 919         return 0;
 920
 921  err:
 922         mutex_lock(&acpi_device_lock);
 923         if (device->parent)
 924                 list_del(&device->node);
 925         list_del(&device->wakeup_list);
 926         mutex_unlock(&acpi_device_lock);
 927
 928  err_detach:
 929         acpi_detach_data(device->handle, acpi_bus_data_handler);
 930         return result;
 931 }
 932
 933 static void acpi_device_unregister(struct acpi_device *device)
 934 {
 935         mutex_lock(&acpi_device_lock);
 936         if (device->parent)
 937                 list_del(&device->node);
 938
 939         list_del(&device->wakeup_list);
 940         mutex_unlock(&acpi_device_lock);
 941
 942         acpi_detach_data(device->handle, acpi_bus_data_handler);
 943
 944         acpi_power_add_remove_device(device, false);
 945         acpi_device_remove_files(device);
 946         if (device->remove)
 947                 device->remove(device);
 948
 949         device_del(&device->dev);
 950         /*
 951          * Transition the device to D3cold to drop the reference counts of all
 952          * power resources the device depends on and turn off the ones that have
 953          * no more references.
 954          */
 955         acpi_device_set_power(device, ACPI_STATE_D3_COLD);
 956         device->handle = NULL;
 957         put_device(&device->dev);
 958 }
 959
 960 /* --------------------------------------------------------------------------
 961                                  Driver Management
 962    -------------------------------------------------------------------------- */
 963 /**
 964  * acpi_bus_driver_init - add a device to a driver
 965  * @device: the device to add and initialize
 966  * @driver: driver for the device
 967  *
 968  * Used to initialize a device via its device driver.  Called whenever a
 969  * driver is bound to a device.  Invokes the driver's add() ops.
 970  */
 971 static int
 972 acpi_bus_driver_init(struct acpi_device *device, struct acpi_driver *driver)
 973 {
 974         int result = 0;
 975
 976         if (!device || !driver)
 977                 return -EINVAL;
 978
 979         if (!driver->ops.add)
 980                 return -ENOSYS;
 981
 982         result = driver->ops.add(device);
 983         if (result) {
 984                 device->driver = NULL;
 985                 device->driver_data = NULL;
 986                 return result;
 987         }
 988
 989         device->driver = driver;
 990
 991         /*
 992          * TBD - Configuration Management: Assign resources to device based
 993          * upon possible configuration and currently allocated resources.
 994          */
 995
 996         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 997                           "Driver successfully bound to device\n"));
 998         return 0;
 999 }
1000
1001 /**
1002  * acpi_bus_register_driver - register a driver with the ACPI bus
1003  * @driver: driver being registered
1004  *
1005  * Registers a driver with the ACPI bus.  Searches the namespace for all
1006  * devices that match the driver's criteria and binds.  Returns zero for
1007  * success or a negative error status for failure.
1008  */
1009 int acpi_bus_register_driver(struct acpi_driver *driver)
1010 {
1011         int ret;
1012
1013         if (acpi_disabled)
1014                 return -ENODEV;
1015         driver->drv.name = driver->name;
1016         driver->drv.bus = &acpi_bus_type;
1017         driver->drv.owner = driver->owner;
1018
1019         ret = driver_register(&driver->drv);
1020         return ret;
1021 }
1022
1023 EXPORT_SYMBOL(acpi_bus_register_driver);
1024
1025 /**
1026  * acpi_bus_unregister_driver - unregisters a driver with the APIC bus
1027  * @driver: driver to unregister
1028  *
1029  * Unregisters a driver with the ACPI bus.  Searches the namespace for all
1030  * devices that match the driver's criteria and unbinds.
1031  */
1032 void acpi_bus_unregister_driver(struct acpi_driver *driver)
1033 {
1034         driver_unregister(&driver->drv);
1035 }
1036
1037 EXPORT_SYMBOL(acpi_bus_unregister_driver);
1038
1039 /* --------------------------------------------------------------------------
1040                                  Device Enumeration
1041    -------------------------------------------------------------------------- */
1042 static struct acpi_device *acpi_bus_get_parent(acpi_handle handle)
1043 {
1044         struct acpi_device *device = NULL;
1045         acpi_status status;
1046
1047         /*
1048          * Fixed hardware devices do not appear in the namespace and do not
1049          * have handles, but we fabricate acpi_devices for them, so we have
1050          * to deal with them specially.
1051          */
1052         if (!handle)
1053                 return acpi_root;
1054
1055         do {
1056                 status = acpi_get_parent(handle, &handle);
1057                 if (ACPI_FAILURE(status))
1058                         return status == AE_NULL_ENTRY ? NULL : acpi_root;
1059         } while (acpi_bus_get_device(handle, &device));
1060         return device;
1061 }
1062
1063 acpi_status
1064 acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
1065 {
1066         acpi_status status;
1067         acpi_handle tmp;
1068         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
1069         union acpi_object *obj;
1070
1071         status = acpi_get_handle(handle, "_EJD", &tmp);
1072         if (ACPI_FAILURE(status))
1073                 return status;
1074
1075         status = acpi_evaluate_object(handle, "_EJD", NULL, &buffer);
1076         if (ACPI_SUCCESS(status)) {
1077                 obj = buffer.pointer;
1078                 status = acpi_get_handle(ACPI_ROOT_OBJECT, obj->string.pointer,
1079                                          ejd);
1080                 kfree(buffer.pointer);
1081         }
1082         return status;
1083 }
1084 EXPORT_SYMBOL_GPL(acpi_bus_get_ejd);
1085
1086 void acpi_bus_data_handler(acpi_handle handle, void *context)
1087 {
1088
1089         /* TBD */
1090
1091         return;
1092 }
1093
1094 static int acpi_bus_extract_wakeup_device_power_package(acpi_handle handle,
1095                                         struct acpi_device_wakeup *wakeup)
1096 {
1097         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1098         union acpi_object *package = NULL;
1099         union acpi_object *element = NULL;
1100         acpi_status status;
1101         int err = -ENODATA;
1102
1103         if (!wakeup)
1104                 return -EINVAL;
1105
1106         INIT_LIST_HEAD(&wakeup->resources);
1107
1108         /* _PRW */
1109         status = acpi_evaluate_object(handle, "_PRW", NULL, &buffer);
1110         if (ACPI_FAILURE(status)) {
1111                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRW"));
1112                 return err;
1113         }
1114
1115         package = (union acpi_object *)buffer.pointer;
1116
1117         if (!package || package->package.count < 2)
1118                 goto out;
1119
1120         element = &(package->package.elements[0]);
1121         if (!element)
1122                 goto out;
1123
1124         if (element->type == ACPI_TYPE_PACKAGE) {
1125                 if ((element->package.count < 2) ||
1126                     (element->package.elements[0].type !=
1127                      ACPI_TYPE_LOCAL_REFERENCE)
1128                     || (element->package.elements[1].type != ACPI_TYPE_INTEGER))
1129                         goto out;
1130
1131                 wakeup->gpe_device =
1132                     element->package.elements[0].reference.handle;
1133                 wakeup->gpe_number =
1134                     (u32) element->package.elements[1].integer.value;
1135         } else if (element->type == ACPI_TYPE_INTEGER) {
1136                 wakeup->gpe_device = NULL;
1137                 wakeup->gpe_number = element->integer.value;
1138         } else {
1139                 goto out;
1140         }
1141
1142         element = &(package->package.elements[1]);
1143         if (element->type != ACPI_TYPE_INTEGER)
1144                 goto out;
1145
1146         wakeup->sleep_state = element->integer.value;
1147
1148         err = acpi_extract_power_resources(package, 2, &wakeup->resources);
1149         if (err)
1150                 goto out;
1151
1152         if (!list_empty(&wakeup->resources)) {
1153                 int sleep_state;
1154
1155                 err = acpi_power_wakeup_list_init(&wakeup->resources,
1156                                                   &sleep_state);
1157                 if (err) {
1158                         acpi_handle_warn(handle, "Retrieving current states "
1159                                          "of wakeup power resources failed\n");
1160                         acpi_power_resources_list_free(&wakeup->resources);
1161                         goto out;
1162                 }
1163                 if (sleep_state < wakeup->sleep_state) {
1164                         acpi_handle_warn(handle, "Overriding _PRW sleep state "
1165                                          "(S%d) by S%d from power resources\n",
1166                                          (int)wakeup->sleep_state, sleep_state);
1167                         wakeup->sleep_state = sleep_state;
1168                 }
1169         }
1170         acpi_setup_gpe_for_wake(handle, wakeup->gpe_device, wakeup->gpe_number);
1171
1172  out:
1173         kfree(buffer.pointer);
1174         return err;
1175 }
1176
1177 static void acpi_bus_set_run_wake_flags(struct acpi_device *device)
1178 {
1179         struct acpi_device_id button_device_ids[] = {
1180                 {"PNP0C0C", 0},
1181                 {"PNP0C0D", 0},
1182                 {"PNP0C0E", 0},
1183                 {"", 0},
1184         };
1185         acpi_status status;
1186         acpi_event_status event_status;
1187
1188         device->wakeup.flags.notifier_present = 0;
1189
1190         /* Power button, Lid switch always enable wakeup */
1191         if (!acpi_match_device_ids(device, button_device_ids)) {
1192                 device->wakeup.flags.run_wake = 1;
1193                 if (!acpi_match_device_ids(device, &button_device_ids[1])) {
1194                         /* Do not use Lid/sleep button for S5 wakeup */
1195                         if (device->wakeup.sleep_state == ACPI_STATE_S5)
1196                                 device->wakeup.sleep_state = ACPI_STATE_S4;
1197                 }
1198                 device_set_wakeup_capable(&device->dev, true);
1199                 return;
1200         }
1201
1202         status = acpi_get_gpe_status(device->wakeup.gpe_device,
1203                                         device->wakeup.gpe_number,
1204                                                 &event_status);
1205         if (status == AE_OK)
1206                 device->wakeup.flags.run_wake =
1207                                 !!(event_status & ACPI_EVENT_FLAG_HANDLE);
1208 }
1209
1210 static void acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
1211 {
1212         acpi_handle temp;
1213         acpi_status status = 0;
1214         int err;
1215
1216         /* Presence of _PRW indicates wake capable */
1217         status = acpi_get_handle(device->handle, "_PRW", &temp);
1218         if (ACPI_FAILURE(status))
1219                 return;
1220
1221         err = acpi_bus_extract_wakeup_device_power_package(device->handle,
1222                                                            &device->wakeup);
1223         if (err) {
1224                 dev_err(&device->dev, "_PRW evaluation error: %d\n", err);
1225                 return;
1226         }
1227
1228         device->wakeup.flags.valid = 1;
1229         device->wakeup.prepare_count = 0;
1230         acpi_bus_set_run_wake_flags(device);
1231         /* Call _PSW/_DSW object to disable its ability to wake the sleeping
1232          * system for the ACPI device with the _PRW object.
1233          * The _PSW object is depreciated in ACPI 3.0 and is replaced by _DSW.
1234          * So it is necessary to call _DSW object first. Only when it is not
1235          * present will the _PSW object used.
1236          */
1237         err = acpi_device_sleep_wake(device, 0, 0, 0);
1238         if (err)
1239                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1240                                 "error in _DSW or _PSW evaluation\n"));
1241 }
1242
1243 static void acpi_bus_init_power_state(struct acpi_device *device, int state)
1244 {
1245         struct acpi_device_power_state *ps = &device->power.states[state];
1246         char pathname[5] = { '_', 'P', 'R', '0' + state, '\0' };
1247         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1248         acpi_handle handle;
1249         acpi_status status;
1250
1251         INIT_LIST_HEAD(&ps->resources);
1252
1253         /* Evaluate "_PRx" to get referenced power resources */
1254         status = acpi_evaluate_object(device->handle, pathname, NULL, &buffer);
1255         if (ACPI_SUCCESS(status)) {
1256                 union acpi_object *package = buffer.pointer;
1257
1258                 if (buffer.length && package
1259                     && package->type == ACPI_TYPE_PACKAGE
1260                     && package->package.count) {
1261                         int err = acpi_extract_power_resources(package, 0,
1262                                                                &ps->resources);
1263                         if (!err)
1264                                 device->power.flags.power_resources = 1;
1265                 }
1266                 ACPI_FREE(buffer.pointer);
1267         }
1268
1269         /* Evaluate "_PSx" to see if we can do explicit sets */
1270         pathname[2] = 'S';
1271         status = acpi_get_handle(device->handle, pathname, &handle);
1272         if (ACPI_SUCCESS(status))
1273                 ps->flags.explicit_set = 1;
1274
1275         /*
1276          * State is valid if there are means to put the device into it.
1277          * D3hot is only valid if _PR3 present.
1278          */
1279         if (!list_empty(&ps->resources)
1280             || (ps->flags.explicit_set && state < ACPI_STATE_D3_HOT)) {
1281                 ps->flags.valid = 1;
1282                 ps->flags.os_accessible = 1;
1283         }
1284
1285         ps->power = -1;         /* Unknown - driver assigned */
1286         ps->latency = -1;       /* Unknown - driver assigned */
1287 }
1288
1289 static void acpi_bus_get_power_flags(struct acpi_device *device)
1290 {
1291         acpi_status status;
1292         acpi_handle handle;
1293         u32 i;
1294
1295         /* Presence of _PS0|_PR0 indicates 'power manageable' */
1296         status = acpi_get_handle(device->handle, "_PS0", &handle);
1297         if (ACPI_FAILURE(status)) {
1298                 status = acpi_get_handle(device->handle, "_PR0", &handle);
1299                 if (ACPI_FAILURE(status))
1300                         return;
1301         }
1302
1303         device->flags.power_manageable = 1;
1304
1305         /*
1306          * Power Management Flags
1307          */
1308         status = acpi_get_handle(device->handle, "_PSC", &handle);
1309         if (ACPI_SUCCESS(status))
1310                 device->power.flags.explicit_get = 1;
1311         status = acpi_get_handle(device->handle, "_IRC", &handle);
1312         if (ACPI_SUCCESS(status))
1313                 device->power.flags.inrush_current = 1;
1314
1315         /*
1316          * Enumerate supported power management states
1317          */
1318         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++)
1319                 acpi_bus_init_power_state(device, i);
1320
1321         INIT_LIST_HEAD(&device->power.states[ACPI_STATE_D3_COLD].resources);
1322
1323         /* Set defaults for D0 and D3 states (always valid) */
1324         device->power.states[ACPI_STATE_D0].flags.valid = 1;
1325         device->power.states[ACPI_STATE_D0].power = 100;
1326         device->power.states[ACPI_STATE_D3].flags.valid = 1;
1327         device->power.states[ACPI_STATE_D3].power = 0;
1328
1329         /* Set D3cold's explicit_set flag if _PS3 exists. */
1330         if (device->power.states[ACPI_STATE_D3_HOT].flags.explicit_set)
1331                 device->power.states[ACPI_STATE_D3_COLD].flags.explicit_set = 1;
1332
1333         /* Presence of _PS3 or _PRx means we can put the device into D3 cold */
1334         if (device->power.states[ACPI_STATE_D3_HOT].flags.explicit_set ||
1335                         device->power.flags.power_resources)
1336                 device->power.states[ACPI_STATE_D3_COLD].flags.os_accessible = 1;
1337
1338         if (acpi_bus_init_power(device)) {
1339                 acpi_free_power_resources_lists(device);
1340                 device->flags.power_manageable = 0;
1341         }
1342 }
1343
1344 static void acpi_bus_get_flags(struct acpi_device *device)
1345 {
1346         acpi_status status = AE_OK;
1347         acpi_handle temp = NULL;
1348
1349         /* Presence of _STA indicates 'dynamic_status' */
1350         status = acpi_get_handle(device->handle, "_STA", &temp);
1351         if (ACPI_SUCCESS(status))
1352                 device->flags.dynamic_status = 1;
1353
1354         /* Presence of _RMV indicates 'removable' */
1355         status = acpi_get_handle(device->handle, "_RMV", &temp);
1356         if (ACPI_SUCCESS(status))
1357                 device->flags.removable = 1;
1358
1359         /* Presence of _EJD|_EJ0 indicates 'ejectable' */
1360         status = acpi_get_handle(device->handle, "_EJD", &temp);
1361         if (ACPI_SUCCESS(status))
1362                 device->flags.ejectable = 1;
1363         else {
1364                 status = acpi_get_handle(device->handle, "_EJ0", &temp);
1365                 if (ACPI_SUCCESS(status))
1366                         device->flags.ejectable = 1;
1367         }
1368 }
1369
1370 static void acpi_device_get_busid(struct acpi_device *device)
1371 {
1372         char bus_id[5] = { '?', 0 };
1373         struct acpi_buffer buffer = { sizeof(bus_id), bus_id };
1374         int i = 0;
1375
1376         /*
1377          * Bus ID
1378          * ------
1379          * The device's Bus ID is simply the object name.
1380          * TBD: Shouldn't this value be unique (within the ACPI namespace)?
1381          */
1382         if (ACPI_IS_ROOT_DEVICE(device)) {
1383                 strcpy(device->pnp.bus_id, "ACPI");
1384                 return;
1385         }
1386
1387         switch (device->device_type) {
1388         case ACPI_BUS_TYPE_POWER_BUTTON:
1389                 strcpy(device->pnp.bus_id, "PWRF");
1390                 break;
1391         case ACPI_BUS_TYPE_SLEEP_BUTTON:
1392                 strcpy(device->pnp.bus_id, "SLPF");
1393                 break;
1394         default:
1395                 acpi_get_name(device->handle, ACPI_SINGLE_NAME, &buffer);
1396                 /* Clean up trailing underscores (if any) */
1397                 for (i = 3; i > 1; i--) {
1398                         if (bus_id[i] == '_')
1399                                 bus_id[i] = '\0';
1400                         else
1401                                 break;
1402                 }
1403                 strcpy(device->pnp.bus_id, bus_id);
1404                 break;
1405         }
1406 }
1407
1408 /*
1409  * acpi_bay_match - see if a device is an ejectable driver bay
1410  *
1411  * If an acpi object is ejectable and has one of the ACPI ATA methods defined,
1412  * then we can safely call it an ejectable drive bay
1413  */
1414 static int acpi_bay_match(struct acpi_device *device){
1415         acpi_status status;
1416         acpi_handle handle;
1417         acpi_handle tmp;
1418         acpi_handle phandle;
1419
1420         handle = device->handle;
1421
1422         status = acpi_get_handle(handle, "_EJ0", &tmp);
1423         if (ACPI_FAILURE(status))
1424                 return -ENODEV;
1425
1426         if ((ACPI_SUCCESS(acpi_get_handle(handle, "_GTF", &tmp))) ||
1427                 (ACPI_SUCCESS(acpi_get_handle(handle, "_GTM", &tmp))) ||
1428                 (ACPI_SUCCESS(acpi_get_handle(handle, "_STM", &tmp))) ||
1429                 (ACPI_SUCCESS(acpi_get_handle(handle, "_SDD", &tmp))))
1430                 return 0;
1431
1432         if (acpi_get_parent(handle, &phandle))
1433                 return -ENODEV;
1434
1435         if ((ACPI_SUCCESS(acpi_get_handle(phandle, "_GTF", &tmp))) ||
1436                 (ACPI_SUCCESS(acpi_get_handle(phandle, "_GTM", &tmp))) ||
1437                 (ACPI_SUCCESS(acpi_get_handle(phandle, "_STM", &tmp))) ||
1438                 (ACPI_SUCCESS(acpi_get_handle(phandle, "_SDD", &tmp))))
1439                 return 0;
1440
1441         return -ENODEV;
1442 }
1443
1444 /*
1445  * acpi_dock_match - see if a device has a _DCK method
1446  */
1447 static int acpi_dock_match(struct acpi_device *device)
1448 {
1449         acpi_handle tmp;
1450         return acpi_get_handle(device->handle, "_DCK", &tmp);
1451 }
1452
1453 const char *acpi_device_hid(struct acpi_device *device)
1454 {
1455         struct acpi_hardware_id *hid;
1456
1457         if (list_empty(&device->pnp.ids))
1458                 return dummy_hid;
1459
1460         hid = list_first_entry(&device->pnp.ids, struct acpi_hardware_id, list);
1461         return hid->id;
1462 }
1463 EXPORT_SYMBOL(acpi_device_hid);
1464
1465 static void acpi_add_id(struct acpi_device *device, const char *dev_id)
1466 {
1467         struct acpi_hardware_id *id;
1468
1469         id = kmalloc(sizeof(*id), GFP_KERNEL);
1470         if (!id)
1471                 return;
1472
1473         id->id = kstrdup(dev_id, GFP_KERNEL);
1474         if (!id->id) {
1475                 kfree(id);
1476                 return;
1477         }
1478
1479         list_add_tail(&id->list, &device->pnp.ids);
1480 }
1481
1482 /*
1483  * Old IBM workstations have a DSDT bug wherein the SMBus object
1484  * lacks the SMBUS01 HID and the methods do not have the necessary "_"
1485  * prefix.  Work around this.
1486  */
1487 static int acpi_ibm_smbus_match(struct acpi_device *device)
1488 {
1489         acpi_handle h_dummy;
1490         struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
1491         int result;
1492
1493         if (!dmi_name_in_vendors("IBM"))
1494                 return -ENODEV;
1495
1496         /* Look for SMBS object */
1497         result = acpi_get_name(device->handle, ACPI_SINGLE_NAME, &path);
1498         if (result)
1499                 return result;
1500
1501         if (strcmp("SMBS", path.pointer)) {
1502                 result = -ENODEV;
1503                 goto out;
1504         }
1505
1506         /* Does it have the necessary (but misnamed) methods? */
1507         result = -ENODEV;
1508         if (ACPI_SUCCESS(acpi_get_handle(device->handle, "SBI", &h_dummy)) &&
1509             ACPI_SUCCESS(acpi_get_handle(device->handle, "SBR", &h_dummy)) &&
1510             ACPI_SUCCESS(acpi_get_handle(device->handle, "SBW", &h_dummy)))
1511                 result = 0;
1512 out:
1513         kfree(path.pointer);
1514         return result;
1515 }
1516
1517 static void acpi_device_set_id(struct acpi_device *device)
1518 {
1519         acpi_status status;
1520         struct acpi_device_info *info;
1521         struct acpi_pnp_device_id_list *cid_list;
1522         int i;
1523
1524         switch (device->device_type) {
1525         case ACPI_BUS_TYPE_DEVICE:
1526                 if (ACPI_IS_ROOT_DEVICE(device)) {
1527                         acpi_add_id(device, ACPI_SYSTEM_HID);
1528                         break;
1529                 }
1530
1531                 status = acpi_get_object_info(device->handle, &info);
1532                 if (ACPI_FAILURE(status)) {
1533                         printk(KERN_ERR PREFIX "%s: Error reading device info\n", __func__);
1534                         return;
1535                 }
1536
1537                 if (info->valid & ACPI_VALID_HID)
1538                         acpi_add_id(device, info->hardware_id.string);
1539                 if (info->valid & ACPI_VALID_CID) {
1540                         cid_list = &info->compatible_id_list;
1541                         for (i = 0; i < cid_list->count; i++)
1542                                 acpi_add_id(device, cid_list->ids[i].string);
1543                 }
1544                 if (info->valid & ACPI_VALID_ADR) {
1545                         device->pnp.bus_address = info->address;
1546                         device->flags.bus_address = 1;
1547                 }
1548                 if (info->valid & ACPI_VALID_UID)
1549                         device->pnp.unique_id = kstrdup(info->unique_id.string,
1550                                                         GFP_KERNEL);
1551
1552                 kfree(info);
1553
1554                 /*
1555                  * Some devices don't reliably have _HIDs & _CIDs, so add
1556                  * synthetic HIDs to make sure drivers can find them.
1557                  */
1558                 if (acpi_is_video_device(device))
1559                         acpi_add_id(device, ACPI_VIDEO_HID);
1560                 else if (ACPI_SUCCESS(acpi_bay_match(device)))
1561                         acpi_add_id(device, ACPI_BAY_HID);
1562                 else if (ACPI_SUCCESS(acpi_dock_match(device)))
1563                         acpi_add_id(device, ACPI_DOCK_HID);
1564                 else if (!acpi_ibm_smbus_match(device))
1565                         acpi_add_id(device, ACPI_SMBUS_IBM_HID);
1566                 else if (list_empty(&device->pnp.ids) &&
1567                          ACPI_IS_ROOT_DEVICE(device->parent)) {
1568                         acpi_add_id(device, ACPI_BUS_HID); /* \_SB, LNXSYBUS */
1569                         strcpy(device->pnp.device_name, ACPI_BUS_DEVICE_NAME);
1570                         strcpy(device->pnp.device_class, ACPI_BUS_CLASS);
1571                 }
1572
1573                 break;
1574         case ACPI_BUS_TYPE_POWER:
1575                 acpi_add_id(device, ACPI_POWER_HID);
1576                 break;
1577         case ACPI_BUS_TYPE_PROCESSOR:
1578                 acpi_add_id(device, ACPI_PROCESSOR_OBJECT_HID);
1579                 break;
1580         case ACPI_BUS_TYPE_THERMAL:
1581                 acpi_add_id(device, ACPI_THERMAL_HID);
1582                 break;
1583         case ACPI_BUS_TYPE_POWER_BUTTON:
1584                 acpi_add_id(device, ACPI_BUTTON_HID_POWERF);
1585                 break;
1586         case ACPI_BUS_TYPE_SLEEP_BUTTON:
1587                 acpi_add_id(device, ACPI_BUTTON_HID_SLEEPF);
1588                 break;
1589         }
1590 }
1591
1592 void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,
1593                              int type, unsigned long long sta)
1594 {
1595         INIT_LIST_HEAD(&device->pnp.ids);
1596         device->device_type = type;
1597         device->handle = handle;
1598         device->parent = acpi_bus_get_parent(handle);
1599         STRUCT_TO_INT(device->status) = sta;
1600         acpi_device_get_busid(device);
1601         acpi_device_set_id(device);
1602         acpi_bus_get_flags(device);
1603         device->flags.match_driver = false;
1604         device_initialize(&device->dev);
1605         dev_set_uevent_suppress(&device->dev, true);
1606 }
1607
1608 void acpi_device_add_finalize(struct acpi_device *device)
1609 {
1610         device->flags.match_driver = true;
1611         dev_set_uevent_suppress(&device->dev, false);
1612         kobject_uevent(&device->dev.kobj, KOBJ_ADD);
1613 }
1614
1615 static int acpi_add_single_object(struct acpi_device **child,
1616                                   acpi_handle handle, int type,
1617                                   unsigned long long sta)
1618 {
1619         int result;
1620         struct acpi_device *device;
1621         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1622
1623         device = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
1624         if (!device) {
1625                 printk(KERN_ERR PREFIX "Memory allocation error\n");
1626                 return -ENOMEM;
1627         }
1628
1629         acpi_init_device_object(device, handle, type, sta);
1630         acpi_bus_get_power_flags(device);
1631         acpi_bus_get_wakeup_device_flags(device);
1632
1633         result = acpi_device_add(device, acpi_device_release);
1634         if (result) {
1635                 acpi_device_release(&device->dev);
1636                 return result;
1637         }
1638
1639         acpi_power_add_remove_device(device, true);
1640         acpi_device_add_finalize(device);
1641         acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
1642         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Added %s [%s] parent %s\n",
1643                 dev_name(&device->dev), (char *) buffer.pointer,
1644                 device->parent ? dev_name(&device->parent->dev) : "(null)"));
1645         kfree(buffer.pointer);
1646         *child = device;
1647         return 0;
1648 }
1649
1650 static int acpi_bus_type_and_status(acpi_handle handle, int *type,
1651                                     unsigned long long *sta)
1652 {
1653         acpi_status status;
1654         acpi_object_type acpi_type;
1655
1656         status = acpi_get_type(handle, &acpi_type);
1657         if (ACPI_FAILURE(status))
1658                 return -ENODEV;
1659
1660         switch (acpi_type) {
1661         case ACPI_TYPE_ANY:             /* for ACPI_ROOT_OBJECT */
1662         case ACPI_TYPE_DEVICE:
1663                 *type = ACPI_BUS_TYPE_DEVICE;
1664                 status = acpi_bus_get_status_handle(handle, sta);
1665                 if (ACPI_FAILURE(status))
1666                         return -ENODEV;
1667                 break;
1668         case ACPI_TYPE_PROCESSOR:
1669                 *type = ACPI_BUS_TYPE_PROCESSOR;
1670                 status = acpi_bus_get_status_handle(handle, sta);
1671                 if (ACPI_FAILURE(status))
1672                         return -ENODEV;
1673                 break;
1674         case ACPI_TYPE_THERMAL:
1675                 *type = ACPI_BUS_TYPE_THERMAL;
1676                 *sta = ACPI_STA_DEFAULT;
1677                 break;
1678         case ACPI_TYPE_POWER:
1679                 *type = ACPI_BUS_TYPE_POWER;
1680                 *sta = ACPI_STA_DEFAULT;
1681                 break;
1682         default:
1683                 return -ENODEV;
1684         }
1685
1686         return 0;
1687 }
1688
1689 static bool acpi_scan_handler_matching(struct acpi_scan_handler *handler,
1690                                        char *idstr,
1691                                        const struct acpi_device_id **matchid)
1692 {
1693         const struct acpi_device_id *devid;
1694
1695         for (devid = handler->ids; devid->id[0]; devid++)
1696                 if (!strcmp((char *)devid->id, idstr)) {
1697                         if (matchid)
1698                                 *matchid = devid;
1699
1700                         return true;
1701                 }
1702
1703         return false;
1704 }
1705
1706 static acpi_status acpi_scan_hotplug_modify(acpi_handle handle,
1707                                             u32 lvl_not_used, void *data,
1708                                             void **ret_not_used)
1709 {
1710         struct acpi_scan_handler *handler = data;
1711         struct acpi_device_info *info;
1712         bool match = false;
1713
1714         if (ACPI_FAILURE(acpi_get_object_info(handle, &info)))
1715                 return AE_OK;
1716
1717         if (info->valid & ACPI_VALID_HID) {
1718                 char *idstr = info->hardware_id.string;
1719                 match = acpi_scan_handler_matching(handler, idstr, NULL);
1720         }
1721         kfree(info);
1722         if (!match)
1723                 return AE_OK;
1724
1725         if (handler->hotplug.enabled)
1726                 acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
1727                                             acpi_hotplug_notify_cb, NULL);
1728         else
1729                 acpi_remove_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
1730                                            acpi_hotplug_notify_cb);
1731
1732         return AE_OK;
1733 }
1734
1735 void acpi_scan_hotplug_enabled(struct acpi_hotplug_profile *hotplug, bool val)
1736 {
1737         struct acpi_scan_handler *handler;
1738
1739         if (!!hotplug->enabled == !!val)
1740                 return;
1741
1742         mutex_lock(&acpi_scan_lock);
1743
1744         hotplug->enabled = val;
1745         handler = container_of(hotplug, struct acpi_scan_handler, hotplug);
1746         acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, ACPI_UINT32_MAX,
1747                             acpi_scan_hotplug_modify, NULL, handler, NULL);
1748
1749         mutex_unlock(&acpi_scan_lock);
1750 }
1751
1752 static struct acpi_scan_handler *acpi_scan_match_handler(char *idstr,
1753                                         const struct acpi_device_id **matchid)
1754 {
1755         struct acpi_scan_handler *handler;
1756
1757         list_for_each_entry(handler, &acpi_scan_handlers_list, list_node)
1758                 if (acpi_scan_handler_matching(handler, idstr, matchid))
1759                         return handler;
1760
1761         return NULL;
1762 }
1763
1764 static void acpi_scan_init_hotplug(acpi_handle handle)
1765 {
1766         struct acpi_device_info *info;
1767         struct acpi_scan_handler *handler;
1768
1769         if (ACPI_FAILURE(acpi_get_object_info(handle, &info)))
1770                 return;
1771
1772         if (!(info->valid & ACPI_VALID_HID)) {
1773                 kfree(info);
1774                 return;
1775         }
1776
1777         /*
1778          * This relies on the fact that acpi_install_notify_handler() will not
1779          * install the same notify handler routine twice for the same handle.
1780          */
1781         handler = acpi_scan_match_handler(info->hardware_id.string, NULL);
1782         kfree(info);
1783         if (handler && handler->hotplug.enabled)
1784                 acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
1785                                             acpi_hotplug_notify_cb, NULL);
1786 }
1787
1788 static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl_not_used,
1789                                       void *not_used, void **return_value)
1790 {
1791         struct acpi_device *device = NULL;
1792         int type;
1793         unsigned long long sta;
1794         acpi_status status;
1795         int result;
1796
1797         acpi_bus_get_device(handle, &device);
1798         if (device)
1799                 goto out;
1800
1801         result = acpi_bus_type_and_status(handle, &type, &sta);
1802         if (result)
1803                 return AE_OK;
1804
1805         if (type == ACPI_BUS_TYPE_POWER) {
1806                 acpi_add_power_resource(handle);
1807                 return AE_OK;
1808         }
1809
1810         acpi_scan_init_hotplug(handle);
1811
1812         if (!(sta & ACPI_STA_DEVICE_PRESENT) &&
1813             !(sta & ACPI_STA_DEVICE_FUNCTIONING)) {
1814                 struct acpi_device_wakeup wakeup;
1815                 acpi_handle temp;
1816
1817                 status = acpi_get_handle(handle, "_PRW", &temp);
1818                 if (ACPI_SUCCESS(status)) {
1819                         acpi_bus_extract_wakeup_device_power_package(handle,
1820                                                                      &wakeup);
1821                         acpi_power_resources_list_free(&wakeup.resources);
1822                 }
1823                 return AE_CTRL_DEPTH;
1824         }
1825
1826         acpi_add_single_object(&device, handle, type, sta);
1827         if (!device)
1828                 return AE_CTRL_DEPTH;
1829
1830  out:
1831         if (!*return_value)
1832                 *return_value = device;
1833
1834         return AE_OK;
1835 }
1836
1837 static int acpi_scan_attach_handler(struct acpi_device *device)
1838 {
1839         struct acpi_hardware_id *hwid;
1840         int ret = 0;
1841
1842         list_for_each_entry(hwid, &device->pnp.ids, list) {
1843                 const struct acpi_device_id *devid;
1844                 struct acpi_scan_handler *handler;
1845
1846                 handler = acpi_scan_match_handler(hwid->id, &devid);
1847                 if (handler) {
1848                         ret = handler->attach(device, devid);
1849                         if (ret > 0) {
1850                                 device->handler = handler;
1851                                 break;
1852                         } else if (ret < 0) {
1853                                 break;
1854                         }
1855                 }
1856         }
1857         return ret;
1858 }
1859
1860 static acpi_status acpi_bus_device_attach(acpi_handle handle, u32 lvl_not_used,
1861                                           void *not_used, void **ret_not_used)
1862 {
1863         struct acpi_device *device;
1864         unsigned long long sta_not_used;
1865         int ret;
1866
1867         /*
1868          * Ignore errors ignored by acpi_bus_check_add() to avoid terminating
1869          * namespace walks prematurely.
1870          */
1871         if (acpi_bus_type_and_status(handle, &ret, &sta_not_used))
1872                 return AE_OK;
1873
1874         if (acpi_bus_get_device(handle, &device))
1875                 return AE_CTRL_DEPTH;
1876
1877         ret = acpi_scan_attach_handler(device);
1878         if (ret)
1879                 return ret > 0 ? AE_OK : AE_CTRL_DEPTH;
1880
1881         ret = device_attach(&device->dev);
1882         return ret >= 0 ? AE_OK : AE_CTRL_DEPTH;
1883 }
1884
1885 /**
1886  * acpi_bus_scan - Add ACPI device node objects in a given namespace scope.
1887  * @handle: Root of the namespace scope to scan.
1888  *
1889  * Scan a given ACPI tree (probably recently hot-plugged) and create and add
1890  * found devices.
1891  *
1892  * If no devices were found, -ENODEV is returned, but it does not mean that
1893  * there has been a real error.  There just have been no suitable ACPI objects
1894  * in the table trunk from which the kernel could create a device and add an
1895  * appropriate driver.
1896  *
1897  * Must be called under acpi_scan_lock.
1898  */
1899 int acpi_bus_scan(acpi_handle handle)
1900 {
1901         void *device = NULL;
1902         int error = 0;
1903
1904         if (ACPI_SUCCESS(acpi_bus_check_add(handle, 0, NULL, &device)))
1905                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
1906                                     acpi_bus_check_add, NULL, NULL, &device);
1907
1908         if (!device)
1909                 error = -ENODEV;
1910         else if (ACPI_SUCCESS(acpi_bus_device_attach(handle, 0, NULL, NULL)))
1911                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
1912                                     acpi_bus_device_attach, NULL, NULL, NULL);
1913
1914         return error;
1915 }
1916 EXPORT_SYMBOL(acpi_bus_scan);
1917
1918 static acpi_status acpi_bus_device_detach(acpi_handle handle, u32 lvl_not_used,
1919                                           void *not_used, void **ret_not_used)
1920 {
1921         struct acpi_device *device = NULL;
1922
1923         if (!acpi_bus_get_device(handle, &device)) {
1924                 struct acpi_scan_handler *dev_handler = device->handler;
1925
1926                 device->removal_type = ACPI_BUS_REMOVAL_EJECT;
1927                 if (dev_handler) {
1928                         if (dev_handler->detach)
1929                                 dev_handler->detach(device);
1930
1931                         device->handler = NULL;
1932                 } else {
1933                         device_release_driver(&device->dev);
1934                 }
1935         }
1936         return AE_OK;
1937 }
1938
1939 static acpi_status acpi_bus_remove(acpi_handle handle, u32 lvl_not_used,
1940                                    void *not_used, void **ret_not_used)
1941 {
1942         struct acpi_device *device = NULL;
1943
1944         if (!acpi_bus_get_device(handle, &device))
1945                 acpi_device_unregister(device);
1946
1947         return AE_OK;
1948 }
1949
1950 /**
1951  * acpi_bus_trim - Remove ACPI device node and all of its descendants
1952  * @start: Root of the ACPI device nodes subtree to remove.
1953  *
1954  * Must be called under acpi_scan_lock.
1955  */
1956 void acpi_bus_trim(struct acpi_device *start)
1957 {
1958         /*
1959          * Execute acpi_bus_device_detach() as a post-order callback to detach
1960          * all ACPI drivers from the device nodes being removed.
1961          */
1962         acpi_walk_namespace(ACPI_TYPE_ANY, start->handle, ACPI_UINT32_MAX, NULL,
1963                             acpi_bus_device_detach, NULL, NULL);
1964         acpi_bus_device_detach(start->handle, 0, NULL, NULL);
1965         /*
1966          * Execute acpi_bus_remove() as a post-order callback to remove device
1967          * nodes in the given namespace scope.
1968          */
1969         acpi_walk_namespace(ACPI_TYPE_ANY, start->handle, ACPI_UINT32_MAX, NULL,
1970                             acpi_bus_remove, NULL, NULL);
1971         acpi_bus_remove(start->handle, 0, NULL, NULL);
1972 }
1973 EXPORT_SYMBOL_GPL(acpi_bus_trim);
1974
1975 static int acpi_bus_scan_fixed(void)
1976 {
1977         int result = 0;
1978
1979         /*
1980          * Enumerate all fixed-feature devices.
1981          */
1982         if (!(acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON)) {
1983                 struct acpi_device *device = NULL;
1984
1985                 result = acpi_add_single_object(&device, NULL,
1986                                                 ACPI_BUS_TYPE_POWER_BUTTON,
1987                                                 ACPI_STA_DEFAULT);
1988                 if (result)
1989                         return result;
1990
1991                 result = device_attach(&device->dev);
1992                 if (result < 0)
1993                         return result;
1994
1995                 device_init_wakeup(&device->dev, true);
1996         }
1997
1998         if (!(acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON)) {
1999                 struct acpi_device *device = NULL;
2000
2001                 result = acpi_add_single_object(&device, NULL,
2002                                                 ACPI_BUS_TYPE_SLEEP_BUTTON,
2003                                                 ACPI_STA_DEFAULT);
2004                 if (result)
2005                         return result;
2006
2007                 result = device_attach(&device->dev);
2008         }
2009
2010         return result < 0 ? result : 0;
2011 }
2012
2013 int __init acpi_scan_init(void)
2014 {
2015         int result;
2016
2017         result = bus_register(&acpi_bus_type);
2018         if (result) {
2019                 /* We don't want to quit even if we failed to add suspend/resume */
2020                 printk(KERN_ERR PREFIX "Could not register bus type\n");
2021         }
2022
2023         acpi_pci_root_init();
2024         acpi_pci_link_init();
2025         acpi_platform_init();
2026         acpi_csrt_init();
2027         acpi_container_init();
2028         acpi_pci_slot_init();
2029         acpi_memory_hotplug_init();
2030
2031         mutex_lock(&acpi_scan_lock);
2032         /*
2033          * Enumerate devices in the ACPI namespace.
2034          */
2035         result = acpi_bus_scan(ACPI_ROOT_OBJECT);
2036         if (result)
2037                 goto out;
2038
2039         result = acpi_bus_get_device(ACPI_ROOT_OBJECT, &acpi_root);
2040         if (result)
2041                 goto out;
2042
2043         result = acpi_bus_scan_fixed();
2044         if (result) {
2045                 acpi_device_unregister(acpi_root);
2046                 goto out;
2047         }
2048
2049         acpi_update_all_gpes();
2050
2051         acpi_pci_root_hp_init();
2052
2053  out:
2054         mutex_unlock(&acpi_scan_lock);
2055         return result;
2056 }