Pileus Git - ~andy/linux/blob - 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(acpi_handle handle, u32 lvl, void *data,
 129                                     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         if (device->handler && !device->handler->hotplug.enabled) {
 140                 *ret_p = &device->dev;
 141                 return AE_SUPPORT;
 142         }
 143
 144         mutex_lock(&device->physical_node_lock);
 145
 146         list_for_each_entry(pn, &device->physical_node_list, node) {
 147                 int ret;
 148
 149                 if (second_pass) {
 150                         /* Skip devices offlined by the first pass. */
 151                         if (pn->put_online)
 152                                 continue;
 153                 } else {
 154                         pn->put_online = false;
 155                 }
 156                 ret = device_offline(pn->dev);
 157                 if (acpi_force_hot_remove)
 158                         continue;
 159
 160                 if (ret >= 0) {
 161                         pn->put_online = !ret;
 162                 } else {
 163                         *ret_p = pn->dev;
 164                         if (second_pass) {
 165                                 status = AE_ERROR;
 166                                 break;
 167                         }
 168                 }
 169         }
 170
 171         mutex_unlock(&device->physical_node_lock);
 172
 173         return status;
 174 }
 175
 176 static acpi_status acpi_bus_online(acpi_handle handle, u32 lvl, void *data,
 177                                    void **ret_p)
 178 {
 179         struct acpi_device *device = NULL;
 180         struct acpi_device_physical_node *pn;
 181
 182         if (acpi_bus_get_device(handle, &device))
 183                 return AE_OK;
 184
 185         mutex_lock(&device->physical_node_lock);
 186
 187         list_for_each_entry(pn, &device->physical_node_list, node)
 188                 if (pn->put_online) {
 189                         device_online(pn->dev);
 190                         pn->put_online = false;
 191                 }
 192
 193         mutex_unlock(&device->physical_node_lock);
 194
 195         return AE_OK;
 196 }
 197
 198 static int acpi_scan_hot_remove(struct acpi_device *device)
 199 {
 200         acpi_handle handle = device->handle;
 201         struct device *errdev;
 202         acpi_status status;
 203         unsigned long long sta;
 204
 205         /* If there is no handle, the device node has been unregistered. */
 206         if (!handle) {
 207                 dev_dbg(&device->dev, "ACPI handle missing\n");
 208                 put_device(&device->dev);
 209                 return -EINVAL;
 210         }
 211
 212         /*
 213          * Carry out two passes here and ignore errors in the first pass,
 214          * because if the devices in question are memory blocks and
 215          * CONFIG_MEMCG is set, one of the blocks may hold data structures
 216          * that the other blocks depend on, but it is not known in advance which
 217          * block holds them.
 218          *
 219          * If the first pass is successful, the second one isn't needed, though.
 220          */
 221         errdev = NULL;
 222         status = acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
 223                                      NULL, acpi_bus_offline, (void *)false,
 224                                      (void **)&errdev);
 225         if (status == AE_SUPPORT) {
 226                 dev_warn(errdev, "Offline disabled.\n");
 227                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
 228                                     acpi_bus_online, NULL, NULL, NULL);
 229                 put_device(&device->dev);
 230                 return -EPERM;
 231         }
 232         acpi_bus_offline(handle, 0, (void *)false, (void **)&errdev);
 233         if (errdev) {
 234                 errdev = NULL;
 235                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
 236                                     NULL, acpi_bus_offline, (void *)true,
 237                                     (void **)&errdev);
 238                 if (!errdev || acpi_force_hot_remove)
 239                         acpi_bus_offline(handle, 0, (void *)true,
 240                                          (void **)&errdev);
 241
 242                 if (errdev && !acpi_force_hot_remove) {
 243                         dev_warn(errdev, "Offline failed.\n");
 244                         acpi_bus_online(handle, 0, NULL, NULL);
 245                         acpi_walk_namespace(ACPI_TYPE_ANY, handle,
 246                                             ACPI_UINT32_MAX, acpi_bus_online,
 247                                             NULL, NULL, NULL);
 248                         put_device(&device->dev);
 249                         return -EBUSY;
 250                 }
 251         }
 252
 253         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 254                 "Hot-removing device %s...\n", dev_name(&device->dev)));
 255
 256         acpi_bus_trim(device);
 257
 258         /* Device node has been unregistered. */
 259         put_device(&device->dev);
 260         device = NULL;
 261
 262         acpi_evaluate_lck(handle, 0);
 263         /*
 264          * TBD: _EJD support.
 265          */
 266         status = acpi_evaluate_ej0(handle);
 267         if (status == AE_NOT_FOUND)
 268                 return -ENODEV;
 269         else if (ACPI_FAILURE(status))
 270                 return -EIO;
 271
 272         /*
 273          * Verify if eject was indeed successful.  If not, log an error
 274          * message.  No need to call _OST since _EJ0 call was made OK.
 275          */
 276         status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
 277         if (ACPI_FAILURE(status)) {
 278                 acpi_handle_warn(handle,
 279                         "Status check after eject failed (0x%x)\n", status);
 280         } else if (sta & ACPI_STA_DEVICE_ENABLED) {
 281                 acpi_handle_warn(handle,
 282                         "Eject incomplete - status 0x%llx\n", sta);
 283         }
 284
 285         return 0;
 286 }
 287
 288 void acpi_bus_device_eject(void *data, u32 ost_src)
 289 {
 290         struct acpi_device *device = data;
 291         acpi_handle handle = device->handle;
 292         u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
 293         int error;
 294
 295         lock_device_hotplug();
 296         mutex_lock(&acpi_scan_lock);
 297
 298         if (ost_src == ACPI_NOTIFY_EJECT_REQUEST)
 299                 acpi_evaluate_hotplug_ost(handle, ACPI_NOTIFY_EJECT_REQUEST,
 300                                           ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
 301
 302         if (device->handler && device->handler->hotplug.mode == AHM_CONTAINER)
 303                 kobject_uevent(&device->dev.kobj, KOBJ_OFFLINE);
 304
 305         error = acpi_scan_hot_remove(device);
 306         if (error == -EPERM) {
 307                 goto err_support;
 308         } else if (error) {
 309                 goto err_out;
 310         }
 311
 312  out:
 313         mutex_unlock(&acpi_scan_lock);
 314         unlock_device_hotplug();
 315         return;
 316
 317  err_support:
 318         ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
 319  err_out:
 320         acpi_evaluate_hotplug_ost(handle, ost_src, ost_code, NULL);
 321         goto out;
 322 }
 323
 324 static void acpi_scan_bus_device_check(void *data, u32 ost_source)
 325 {
 326         acpi_handle handle = data;
 327         struct acpi_device *device = NULL;
 328         u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
 329         int error;
 330
 331         lock_device_hotplug();
 332         mutex_lock(&acpi_scan_lock);
 333
 334         if (ost_source != ACPI_NOTIFY_BUS_CHECK) {
 335                 acpi_bus_get_device(handle, &device);
 336                 if (device) {
 337                         dev_warn(&device->dev, "Attempt to re-insert\n");
 338                         goto out;
 339                 }
 340         }
 341         error = acpi_bus_scan(handle);
 342         if (error) {
 343                 acpi_handle_warn(handle, "Namespace scan failure\n");
 344                 goto out;
 345         }
 346         error = acpi_bus_get_device(handle, &device);
 347         if (error) {
 348                 acpi_handle_warn(handle, "Missing device node object\n");
 349                 goto out;
 350         }
 351         ost_code = ACPI_OST_SC_SUCCESS;
 352         if (device->handler && device->handler->hotplug.mode == AHM_CONTAINER)
 353                 kobject_uevent(&device->dev.kobj, KOBJ_ONLINE);
 354
 355  out:
 356         acpi_evaluate_hotplug_ost(handle, ost_source, ost_code, NULL);
 357         mutex_unlock(&acpi_scan_lock);
 358         unlock_device_hotplug();
 359 }
 360
 361 static void acpi_hotplug_unsupported(acpi_handle handle, u32 type)
 362 {
 363         u32 ost_status;
 364
 365         switch (type) {
 366         case ACPI_NOTIFY_BUS_CHECK:
 367                 acpi_handle_debug(handle,
 368                         "ACPI_NOTIFY_BUS_CHECK event: unsupported\n");
 369                 ost_status = ACPI_OST_SC_INSERT_NOT_SUPPORTED;
 370                 break;
 371         case ACPI_NOTIFY_DEVICE_CHECK:
 372                 acpi_handle_debug(handle,
 373                         "ACPI_NOTIFY_DEVICE_CHECK event: unsupported\n");
 374                 ost_status = ACPI_OST_SC_INSERT_NOT_SUPPORTED;
 375                 break;
 376         case ACPI_NOTIFY_EJECT_REQUEST:
 377                 acpi_handle_debug(handle,
 378                         "ACPI_NOTIFY_EJECT_REQUEST event: unsupported\n");
 379                 ost_status = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
 380                 break;
 381         default:
 382                 /* non-hotplug event; possibly handled by other handler */
 383                 return;
 384         }
 385
 386         acpi_evaluate_hotplug_ost(handle, type, ost_status, NULL);
 387 }
 388
 389 static void acpi_hotplug_notify_cb(acpi_handle handle, u32 type, void *data)
 390 {
 391         struct acpi_scan_handler *handler = data;
 392         struct acpi_device *adev;
 393         acpi_status status;
 394
 395         if (!handler->hotplug.enabled)
 396                 return acpi_hotplug_unsupported(handle, type);
 397
 398         switch (type) {
 399         case ACPI_NOTIFY_BUS_CHECK:
 400                 acpi_handle_debug(handle, "ACPI_NOTIFY_BUS_CHECK event\n");
 401                 break;
 402         case ACPI_NOTIFY_DEVICE_CHECK:
 403                 acpi_handle_debug(handle, "ACPI_NOTIFY_DEVICE_CHECK event\n");
 404                 break;
 405         case ACPI_NOTIFY_EJECT_REQUEST:
 406                 acpi_handle_debug(handle, "ACPI_NOTIFY_EJECT_REQUEST event\n");
 407                 if (acpi_bus_get_device(handle, &adev))
 408                         goto err_out;
 409
 410                 get_device(&adev->dev);
 411                 status = acpi_hotplug_execute(acpi_bus_device_eject, adev, type);
 412                 if (ACPI_SUCCESS(status))
 413                         return;
 414
 415                 put_device(&adev->dev);
 416                 goto err_out;
 417         default:
 418                 /* non-hotplug event; possibly handled by other handler */
 419                 return;
 420         }
 421         status = acpi_hotplug_execute(acpi_scan_bus_device_check, handle, type);
 422         if (ACPI_SUCCESS(status))
 423                 return;
 424
 425  err_out:
 426         acpi_evaluate_hotplug_ost(handle, type,
 427                                   ACPI_OST_SC_NON_SPECIFIC_FAILURE, NULL);
 428 }
 429
 430 static ssize_t real_power_state_show(struct device *dev,
 431                                      struct device_attribute *attr, char *buf)
 432 {
 433         struct acpi_device *adev = to_acpi_device(dev);
 434         int state;
 435         int ret;
 436
 437         ret = acpi_device_get_power(adev, &state);
 438         if (ret)
 439                 return ret;
 440
 441         return sprintf(buf, "%s\n", acpi_power_state_string(state));
 442 }
 443
 444 static DEVICE_ATTR(real_power_state, 0444, real_power_state_show, NULL);
 445
 446 static ssize_t power_state_show(struct device *dev,
 447                                 struct device_attribute *attr, char *buf)
 448 {
 449         struct acpi_device *adev = to_acpi_device(dev);
 450
 451         return sprintf(buf, "%s\n", acpi_power_state_string(adev->power.state));
 452 }
 453
 454 static DEVICE_ATTR(power_state, 0444, power_state_show, NULL);
 455
 456 static ssize_t
 457 acpi_eject_store(struct device *d, struct device_attribute *attr,
 458                 const char *buf, size_t count)
 459 {
 460         struct acpi_device *acpi_device = to_acpi_device(d);
 461         acpi_object_type not_used;
 462         acpi_status status;
 463
 464         if (!count || buf[0] != '1')
 465                 return -EINVAL;
 466
 467         if ((!acpi_device->handler || !acpi_device->handler->hotplug.enabled)
 468             && !acpi_device->driver)
 469                 return -ENODEV;
 470
 471         status = acpi_get_type(acpi_device->handle, &not_used);
 472         if (ACPI_FAILURE(status) || !acpi_device->flags.ejectable)
 473                 return -ENODEV;
 474
 475         acpi_evaluate_hotplug_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,
 476                                   ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
 477         get_device(&acpi_device->dev);
 478         status = acpi_hotplug_execute(acpi_bus_device_eject, acpi_device,
 479                                       ACPI_OST_EC_OSPM_EJECT);
 480         if (ACPI_SUCCESS(status))
 481                 return count;
 482
 483         put_device(&acpi_device->dev);
 484         acpi_evaluate_hotplug_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,
 485                                   ACPI_OST_SC_NON_SPECIFIC_FAILURE, NULL);
 486         return status == AE_NO_MEMORY ? -ENOMEM : -EAGAIN;
 487 }
 488
 489 static DEVICE_ATTR(eject, 0200, NULL, acpi_eject_store);
 490
 491 static ssize_t
 492 acpi_device_hid_show(struct device *dev, struct device_attribute *attr, char *buf) {
 493         struct acpi_device *acpi_dev = to_acpi_device(dev);
 494
 495         return sprintf(buf, "%s\n", acpi_device_hid(acpi_dev));
 496 }
 497 static DEVICE_ATTR(hid, 0444, acpi_device_hid_show, NULL);
 498
 499 static ssize_t acpi_device_uid_show(struct device *dev,
 500                                     struct device_attribute *attr, char *buf)
 501 {
 502         struct acpi_device *acpi_dev = to_acpi_device(dev);
 503
 504         return sprintf(buf, "%s\n", acpi_dev->pnp.unique_id);
 505 }
 506 static DEVICE_ATTR(uid, 0444, acpi_device_uid_show, NULL);
 507
 508 static ssize_t acpi_device_adr_show(struct device *dev,
 509                                     struct device_attribute *attr, char *buf)
 510 {
 511         struct acpi_device *acpi_dev = to_acpi_device(dev);
 512
 513         return sprintf(buf, "0x%08x\n",
 514                        (unsigned int)(acpi_dev->pnp.bus_address));
 515 }
 516 static DEVICE_ATTR(adr, 0444, acpi_device_adr_show, NULL);
 517
 518 static ssize_t
 519 acpi_device_path_show(struct device *dev, struct device_attribute *attr, char *buf) {
 520         struct acpi_device *acpi_dev = to_acpi_device(dev);
 521         struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
 522         int result;
 523
 524         result = acpi_get_name(acpi_dev->handle, ACPI_FULL_PATHNAME, &path);
 525         if (result)
 526                 goto end;
 527
 528         result = sprintf(buf, "%s\n", (char*)path.pointer);
 529         kfree(path.pointer);
 530 end:
 531         return result;
 532 }
 533 static DEVICE_ATTR(path, 0444, acpi_device_path_show, NULL);
 534
 535 /* sysfs file that shows description text from the ACPI _STR method */
 536 static ssize_t description_show(struct device *dev,
 537                                 struct device_attribute *attr,
 538                                 char *buf) {
 539         struct acpi_device *acpi_dev = to_acpi_device(dev);
 540         int result;
 541
 542         if (acpi_dev->pnp.str_obj == NULL)
 543                 return 0;
 544
 545         /*
 546          * The _STR object contains a Unicode identifier for a device.
 547          * We need to convert to utf-8 so it can be displayed.
 548          */
 549         result = utf16s_to_utf8s(
 550                 (wchar_t *)acpi_dev->pnp.str_obj->buffer.pointer,
 551                 acpi_dev->pnp.str_obj->buffer.length,
 552                 UTF16_LITTLE_ENDIAN, buf,
 553                 PAGE_SIZE);
 554
 555         buf[result++] = '\n';
 556
 557         return result;
 558 }
 559 static DEVICE_ATTR(description, 0444, description_show, NULL);
 560
 561 static ssize_t
 562 acpi_device_sun_show(struct device *dev, struct device_attribute *attr,
 563                      char *buf) {
 564         struct acpi_device *acpi_dev = to_acpi_device(dev);
 565
 566         return sprintf(buf, "%lu\n", acpi_dev->pnp.sun);
 567 }
 568 static DEVICE_ATTR(sun, 0444, acpi_device_sun_show, NULL);
 569
 570 static int acpi_device_setup_files(struct acpi_device *dev)
 571 {
 572         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
 573         acpi_status status;
 574         unsigned long long sun;
 575         int result = 0;
 576
 577         /*
 578          * Devices gotten from FADT don't have a "path" attribute
 579          */
 580         if (dev->handle) {
 581                 result = device_create_file(&dev->dev, &dev_attr_path);
 582                 if (result)
 583                         goto end;
 584         }
 585
 586         if (!list_empty(&dev->pnp.ids)) {
 587                 result = device_create_file(&dev->dev, &dev_attr_hid);
 588                 if (result)
 589                         goto end;
 590
 591                 result = device_create_file(&dev->dev, &dev_attr_modalias);
 592                 if (result)
 593                         goto end;
 594         }
 595
 596         /*
 597          * If device has _STR, 'description' file is created
 598          */
 599         if (acpi_has_method(dev->handle, "_STR")) {
 600                 status = acpi_evaluate_object(dev->handle, "_STR",
 601                                         NULL, &buffer);
 602                 if (ACPI_FAILURE(status))
 603                         buffer.pointer = NULL;
 604                 dev->pnp.str_obj = buffer.pointer;
 605                 result = device_create_file(&dev->dev, &dev_attr_description);
 606                 if (result)
 607                         goto end;
 608         }
 609
 610         if (dev->pnp.type.bus_address)
 611                 result = device_create_file(&dev->dev, &dev_attr_adr);
 612         if (dev->pnp.unique_id)
 613                 result = device_create_file(&dev->dev, &dev_attr_uid);
 614
 615         status = acpi_evaluate_integer(dev->handle, "_SUN", NULL, &sun);
 616         if (ACPI_SUCCESS(status)) {
 617                 dev->pnp.sun = (unsigned long)sun;
 618                 result = device_create_file(&dev->dev, &dev_attr_sun);
 619                 if (result)
 620                         goto end;
 621         } else {
 622                 dev->pnp.sun = (unsigned long)-1;
 623         }
 624
 625         /*
 626          * If device has _EJ0, 'eject' file is created that is used to trigger
 627          * hot-removal function from userland.
 628          */
 629         if (acpi_has_method(dev->handle, "_EJ0")) {
 630                 result = device_create_file(&dev->dev, &dev_attr_eject);
 631                 if (result)
 632                         return result;
 633         }
 634
 635         if (dev->flags.power_manageable) {
 636                 result = device_create_file(&dev->dev, &dev_attr_power_state);
 637                 if (result)
 638                         return result;
 639
 640                 if (dev->power.flags.power_resources)
 641                         result = device_create_file(&dev->dev,
 642                                                     &dev_attr_real_power_state);
 643         }
 644
 645 end:
 646         return result;
 647 }
 648
 649 static void acpi_device_remove_files(struct acpi_device *dev)
 650 {
 651         if (dev->flags.power_manageable) {
 652                 device_remove_file(&dev->dev, &dev_attr_power_state);
 653                 if (dev->power.flags.power_resources)
 654                         device_remove_file(&dev->dev,
 655                                            &dev_attr_real_power_state);
 656         }
 657
 658         /*
 659          * If device has _STR, remove 'description' file
 660          */
 661         if (acpi_has_method(dev->handle, "_STR")) {
 662                 kfree(dev->pnp.str_obj);
 663                 device_remove_file(&dev->dev, &dev_attr_description);
 664         }
 665         /*
 666          * If device has _EJ0, remove 'eject' file.
 667          */
 668         if (acpi_has_method(dev->handle, "_EJ0"))
 669                 device_remove_file(&dev->dev, &dev_attr_eject);
 670
 671         if (acpi_has_method(dev->handle, "_SUN"))
 672                 device_remove_file(&dev->dev, &dev_attr_sun);
 673
 674         if (dev->pnp.unique_id)
 675                 device_remove_file(&dev->dev, &dev_attr_uid);
 676         if (dev->pnp.type.bus_address)
 677                 device_remove_file(&dev->dev, &dev_attr_adr);
 678         device_remove_file(&dev->dev, &dev_attr_modalias);
 679         device_remove_file(&dev->dev, &dev_attr_hid);
 680         if (dev->handle)
 681                 device_remove_file(&dev->dev, &dev_attr_path);
 682 }
 683 /* --------------------------------------------------------------------------
 684                         ACPI Bus operations
 685    -------------------------------------------------------------------------- */
 686
 687 static const struct acpi_device_id *__acpi_match_device(
 688         struct acpi_device *device, const struct acpi_device_id *ids)
 689 {
 690         const struct acpi_device_id *id;
 691         struct acpi_hardware_id *hwid;
 692
 693         /*
 694          * If the device is not present, it is unnecessary to load device
 695          * driver for it.
 696          */
 697         if (!device->status.present)
 698                 return NULL;
 699
 700         for (id = ids; id->id[0]; id++)
 701                 list_for_each_entry(hwid, &device->pnp.ids, list)
 702                         if (!strcmp((char *) id->id, hwid->id))
 703                                 return id;
 704
 705         return NULL;
 706 }
 707
 708 /**
 709  * acpi_match_device - Match a struct device against a given list of ACPI IDs
 710  * @ids: Array of struct acpi_device_id object to match against.
 711  * @dev: The device structure to match.
 712  *
 713  * Check if @dev has a valid ACPI handle and if there is a struct acpi_device
 714  * object for that handle and use that object to match against a given list of
 715  * device IDs.
 716  *
 717  * Return a pointer to the first matching ID on success or %NULL on failure.
 718  */
 719 const struct acpi_device_id *acpi_match_device(const struct acpi_device_id *ids,
 720                                                const struct device *dev)
 721 {
 722         struct acpi_device *adev;
 723         acpi_handle handle = ACPI_HANDLE(dev);
 724
 725         if (!ids || !handle || acpi_bus_get_device(handle, &adev))
 726                 return NULL;
 727
 728         return __acpi_match_device(adev, ids);
 729 }
 730 EXPORT_SYMBOL_GPL(acpi_match_device);
 731
 732 int acpi_match_device_ids(struct acpi_device *device,
 733                           const struct acpi_device_id *ids)
 734 {
 735         return __acpi_match_device(device, ids) ? 0 : -ENOENT;
 736 }
 737 EXPORT_SYMBOL(acpi_match_device_ids);
 738
 739 static void acpi_free_power_resources_lists(struct acpi_device *device)
 740 {
 741         int i;
 742
 743         if (device->wakeup.flags.valid)
 744                 acpi_power_resources_list_free(&device->wakeup.resources);
 745
 746         if (!device->flags.power_manageable)
 747                 return;
 748
 749         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
 750                 struct acpi_device_power_state *ps = &device->power.states[i];
 751                 acpi_power_resources_list_free(&ps->resources);
 752         }
 753 }
 754
 755 static void acpi_device_release(struct device *dev)
 756 {
 757         struct acpi_device *acpi_dev = to_acpi_device(dev);
 758
 759         acpi_free_pnp_ids(&acpi_dev->pnp);
 760         acpi_free_power_resources_lists(acpi_dev);
 761         kfree(acpi_dev);
 762 }
 763
 764 static int acpi_bus_match(struct device *dev, struct device_driver *drv)
 765 {
 766         struct acpi_device *acpi_dev = to_acpi_device(dev);
 767         struct acpi_driver *acpi_drv = to_acpi_driver(drv);
 768
 769         return acpi_dev->flags.match_driver
 770                 && !acpi_match_device_ids(acpi_dev, acpi_drv->ids);
 771 }
 772
 773 static int acpi_device_uevent(struct device *dev, struct kobj_uevent_env *env)
 774 {
 775         struct acpi_device *acpi_dev = to_acpi_device(dev);
 776         int len;
 777
 778         if (list_empty(&acpi_dev->pnp.ids))
 779                 return 0;
 780
 781         if (add_uevent_var(env, "MODALIAS="))
 782                 return -ENOMEM;
 783         len = create_modalias(acpi_dev, &env->buf[env->buflen - 1],
 784                               sizeof(env->buf) - env->buflen);
 785         if (len >= (sizeof(env->buf) - env->buflen))
 786                 return -ENOMEM;
 787         env->buflen += len;
 788         return 0;
 789 }
 790
 791 static void acpi_device_notify(acpi_handle handle, u32 event, void *data)
 792 {
 793         struct acpi_device *device = data;
 794
 795         device->driver->ops.notify(device, event);
 796 }
 797
 798 static acpi_status acpi_device_notify_fixed(void *data)
 799 {
 800         struct acpi_device *device = data;
 801
 802         /* Fixed hardware devices have no handles */
 803         acpi_device_notify(NULL, ACPI_FIXED_HARDWARE_EVENT, device);
 804         return AE_OK;
 805 }
 806
 807 static int acpi_device_install_notify_handler(struct acpi_device *device)
 808 {
 809         acpi_status status;
 810
 811         if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
 812                 status =
 813                     acpi_install_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
 814                                                      acpi_device_notify_fixed,
 815                                                      device);
 816         else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
 817                 status =
 818                     acpi_install_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
 819                                                      acpi_device_notify_fixed,
 820                                                      device);
 821         else
 822                 status = acpi_install_notify_handler(device->handle,
 823                                                      ACPI_DEVICE_NOTIFY,
 824                                                      acpi_device_notify,
 825                                                      device);
 826
 827         if (ACPI_FAILURE(status))
 828                 return -EINVAL;
 829         return 0;
 830 }
 831
 832 static void acpi_device_remove_notify_handler(struct acpi_device *device)
 833 {
 834         if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
 835                 acpi_remove_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
 836                                                 acpi_device_notify_fixed);
 837         else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
 838                 acpi_remove_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
 839                                                 acpi_device_notify_fixed);
 840         else
 841                 acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
 842                                            acpi_device_notify);
 843 }
 844
 845 static int acpi_device_probe(struct device *dev)
 846 {
 847         struct acpi_device *acpi_dev = to_acpi_device(dev);
 848         struct acpi_driver *acpi_drv = to_acpi_driver(dev->driver);
 849         int ret;
 850
 851         if (acpi_dev->handler)
 852                 return -EINVAL;
 853
 854         if (!acpi_drv->ops.add)
 855                 return -ENOSYS;
 856
 857         ret = acpi_drv->ops.add(acpi_dev);
 858         if (ret)
 859                 return ret;
 860
 861         acpi_dev->driver = acpi_drv;
 862         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 863                           "Driver [%s] successfully bound to device [%s]\n",
 864                           acpi_drv->name, acpi_dev->pnp.bus_id));
 865
 866         if (acpi_drv->ops.notify) {
 867                 ret = acpi_device_install_notify_handler(acpi_dev);
 868                 if (ret) {
 869                         if (acpi_drv->ops.remove)
 870                                 acpi_drv->ops.remove(acpi_dev);
 871
 872                         acpi_dev->driver = NULL;
 873                         acpi_dev->driver_data = NULL;
 874                         return ret;
 875                 }
 876         }
 877
 878         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found driver [%s] for device [%s]\n",
 879                           acpi_drv->name, acpi_dev->pnp.bus_id));
 880         get_device(dev);
 881         return 0;
 882 }
 883
 884 static int acpi_device_remove(struct device * dev)
 885 {
 886         struct acpi_device *acpi_dev = to_acpi_device(dev);
 887         struct acpi_driver *acpi_drv = acpi_dev->driver;
 888
 889         if (acpi_drv) {
 890                 if (acpi_drv->ops.notify)
 891                         acpi_device_remove_notify_handler(acpi_dev);
 892                 if (acpi_drv->ops.remove)
 893                         acpi_drv->ops.remove(acpi_dev);
 894         }
 895         acpi_dev->driver = NULL;
 896         acpi_dev->driver_data = NULL;
 897
 898         put_device(dev);
 899         return 0;
 900 }
 901
 902 struct bus_type acpi_bus_type = {
 903         .name           = "acpi",
 904         .match          = acpi_bus_match,
 905         .probe          = acpi_device_probe,
 906         .remove         = acpi_device_remove,
 907         .uevent         = acpi_device_uevent,
 908 };
 909
 910 static void acpi_bus_data_handler(acpi_handle handle, void *context)
 911 {
 912         /* Intentionally empty. */
 913 }
 914
 915 int acpi_bus_get_device(acpi_handle handle, struct acpi_device **device)
 916 {
 917         acpi_status status;
 918
 919         if (!device)
 920                 return -EINVAL;
 921
 922         status = acpi_get_data(handle, acpi_bus_data_handler, (void **)device);
 923         if (ACPI_FAILURE(status) || !*device) {
 924                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No context for object [%p]\n",
 925                                   handle));
 926                 return -ENODEV;
 927         }
 928         return 0;
 929 }
 930 EXPORT_SYMBOL_GPL(acpi_bus_get_device);
 931
 932 int acpi_device_add(struct acpi_device *device,
 933                     void (*release)(struct device *))
 934 {
 935         int result;
 936         struct acpi_device_bus_id *acpi_device_bus_id, *new_bus_id;
 937         int found = 0;
 938
 939         if (device->handle) {
 940                 acpi_status status;
 941
 942                 status = acpi_attach_data(device->handle, acpi_bus_data_handler,
 943                                           device);
 944                 if (ACPI_FAILURE(status)) {
 945                         acpi_handle_err(device->handle,
 946                                         "Unable to attach device data\n");
 947                         return -ENODEV;
 948                 }
 949         }
 950
 951         /*
 952          * Linkage
 953          * -------
 954          * Link this device to its parent and siblings.
 955          */
 956         INIT_LIST_HEAD(&device->children);
 957         INIT_LIST_HEAD(&device->node);
 958         INIT_LIST_HEAD(&device->wakeup_list);
 959         INIT_LIST_HEAD(&device->physical_node_list);
 960         mutex_init(&device->physical_node_lock);
 961         INIT_LIST_HEAD(&device->power_dependent);
 962
 963         new_bus_id = kzalloc(sizeof(struct acpi_device_bus_id), GFP_KERNEL);
 964         if (!new_bus_id) {
 965                 pr_err(PREFIX "Memory allocation error\n");
 966                 result = -ENOMEM;
 967                 goto err_detach;
 968         }
 969
 970         mutex_lock(&acpi_device_lock);
 971         /*
 972          * Find suitable bus_id and instance number in acpi_bus_id_list
 973          * If failed, create one and link it into acpi_bus_id_list
 974          */
 975         list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
 976                 if (!strcmp(acpi_device_bus_id->bus_id,
 977                             acpi_device_hid(device))) {
 978                         acpi_device_bus_id->instance_no++;
 979                         found = 1;
 980                         kfree(new_bus_id);
 981                         break;
 982                 }
 983         }
 984         if (!found) {
 985                 acpi_device_bus_id = new_bus_id;
 986                 strcpy(acpi_device_bus_id->bus_id, acpi_device_hid(device));
 987                 acpi_device_bus_id->instance_no = 0;
 988                 list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
 989         }
 990         dev_set_name(&device->dev, "%s:%02x", acpi_device_bus_id->bus_id, acpi_device_bus_id->instance_no);
 991
 992         if (device->parent)
 993                 list_add_tail(&device->node, &device->parent->children);
 994
 995         if (device->wakeup.flags.valid)
 996                 list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);
 997         mutex_unlock(&acpi_device_lock);
 998
 999         if (device->parent)
1000                 device->dev.parent = &device->parent->dev;
1001         device->dev.bus = &acpi_bus_type;
1002         device->dev.release = release;
1003         result = device_add(&device->dev);
1004         if (result) {
1005                 dev_err(&device->dev, "Error registering device\n");
1006                 goto err;
1007         }
1008
1009         result = acpi_device_setup_files(device);
1010         if (result)
1011                 printk(KERN_ERR PREFIX "Error creating sysfs interface for device %s\n",
1012                        dev_name(&device->dev));
1013
1014         return 0;
1015
1016  err:
1017         mutex_lock(&acpi_device_lock);
1018         if (device->parent)
1019                 list_del(&device->node);
1020         list_del(&device->wakeup_list);
1021         mutex_unlock(&acpi_device_lock);
1022
1023  err_detach:
1024         acpi_detach_data(device->handle, acpi_bus_data_handler);
1025         return result;
1026 }
1027
1028 static void acpi_device_unregister(struct acpi_device *device)
1029 {
1030         mutex_lock(&acpi_device_lock);
1031         if (device->parent)
1032                 list_del(&device->node);
1033
1034         list_del(&device->wakeup_list);
1035         mutex_unlock(&acpi_device_lock);
1036
1037         acpi_detach_data(device->handle, acpi_bus_data_handler);
1038
1039         acpi_power_add_remove_device(device, false);
1040         acpi_device_remove_files(device);
1041         if (device->remove)
1042                 device->remove(device);
1043
1044         device_del(&device->dev);
1045         /*
1046          * Transition the device to D3cold to drop the reference counts of all
1047          * power resources the device depends on and turn off the ones that have
1048          * no more references.
1049          */
1050         acpi_device_set_power(device, ACPI_STATE_D3_COLD);
1051         device->handle = NULL;
1052         put_device(&device->dev);
1053 }
1054
1055 /* --------------------------------------------------------------------------
1056                                  Driver Management
1057    -------------------------------------------------------------------------- */
1058 /**
1059  * acpi_bus_register_driver - register a driver with the ACPI bus
1060  * @driver: driver being registered
1061  *
1062  * Registers a driver with the ACPI bus.  Searches the namespace for all
1063  * devices that match the driver's criteria and binds.  Returns zero for
1064  * success or a negative error status for failure.
1065  */
1066 int acpi_bus_register_driver(struct acpi_driver *driver)
1067 {
1068         int ret;
1069
1070         if (acpi_disabled)
1071                 return -ENODEV;
1072         driver->drv.name = driver->name;
1073         driver->drv.bus = &acpi_bus_type;
1074         driver->drv.owner = driver->owner;
1075
1076         ret = driver_register(&driver->drv);
1077         return ret;
1078 }
1079
1080 EXPORT_SYMBOL(acpi_bus_register_driver);
1081
1082 /**
1083  * acpi_bus_unregister_driver - unregisters a driver with the APIC bus
1084  * @driver: driver to unregister
1085  *
1086  * Unregisters a driver with the ACPI bus.  Searches the namespace for all
1087  * devices that match the driver's criteria and unbinds.
1088  */
1089 void acpi_bus_unregister_driver(struct acpi_driver *driver)
1090 {
1091         driver_unregister(&driver->drv);
1092 }
1093
1094 EXPORT_SYMBOL(acpi_bus_unregister_driver);
1095
1096 /* --------------------------------------------------------------------------
1097                                  Device Enumeration
1098    -------------------------------------------------------------------------- */
1099 static struct acpi_device *acpi_bus_get_parent(acpi_handle handle)
1100 {
1101         struct acpi_device *device = NULL;
1102         acpi_status status;
1103
1104         /*
1105          * Fixed hardware devices do not appear in the namespace and do not
1106          * have handles, but we fabricate acpi_devices for them, so we have
1107          * to deal with them specially.
1108          */
1109         if (!handle)
1110                 return acpi_root;
1111
1112         do {
1113                 status = acpi_get_parent(handle, &handle);
1114                 if (ACPI_FAILURE(status))
1115                         return status == AE_NULL_ENTRY ? NULL : acpi_root;
1116         } while (acpi_bus_get_device(handle, &device));
1117         return device;
1118 }
1119
1120 acpi_status
1121 acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
1122 {
1123         acpi_status status;
1124         acpi_handle tmp;
1125         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
1126         union acpi_object *obj;
1127
1128         status = acpi_get_handle(handle, "_EJD", &tmp);
1129         if (ACPI_FAILURE(status))
1130                 return status;
1131
1132         status = acpi_evaluate_object(handle, "_EJD", NULL, &buffer);
1133         if (ACPI_SUCCESS(status)) {
1134                 obj = buffer.pointer;
1135                 status = acpi_get_handle(ACPI_ROOT_OBJECT, obj->string.pointer,
1136                                          ejd);
1137                 kfree(buffer.pointer);
1138         }
1139         return status;
1140 }
1141 EXPORT_SYMBOL_GPL(acpi_bus_get_ejd);
1142
1143 static int acpi_bus_extract_wakeup_device_power_package(acpi_handle handle,
1144                                         struct acpi_device_wakeup *wakeup)
1145 {
1146         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1147         union acpi_object *package = NULL;
1148         union acpi_object *element = NULL;
1149         acpi_status status;
1150         int err = -ENODATA;
1151
1152         if (!wakeup)
1153                 return -EINVAL;
1154
1155         INIT_LIST_HEAD(&wakeup->resources);
1156
1157         /* _PRW */
1158         status = acpi_evaluate_object(handle, "_PRW", NULL, &buffer);
1159         if (ACPI_FAILURE(status)) {
1160                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRW"));
1161                 return err;
1162         }
1163
1164         package = (union acpi_object *)buffer.pointer;
1165
1166         if (!package || package->package.count < 2)
1167                 goto out;
1168
1169         element = &(package->package.elements[0]);
1170         if (!element)
1171                 goto out;
1172
1173         if (element->type == ACPI_TYPE_PACKAGE) {
1174                 if ((element->package.count < 2) ||
1175                     (element->package.elements[0].type !=
1176                      ACPI_TYPE_LOCAL_REFERENCE)
1177                     || (element->package.elements[1].type != ACPI_TYPE_INTEGER))
1178                         goto out;
1179
1180                 wakeup->gpe_device =
1181                     element->package.elements[0].reference.handle;
1182                 wakeup->gpe_number =
1183                     (u32) element->package.elements[1].integer.value;
1184         } else if (element->type == ACPI_TYPE_INTEGER) {
1185                 wakeup->gpe_device = NULL;
1186                 wakeup->gpe_number = element->integer.value;
1187         } else {
1188                 goto out;
1189         }
1190
1191         element = &(package->package.elements[1]);
1192         if (element->type != ACPI_TYPE_INTEGER)
1193                 goto out;
1194
1195         wakeup->sleep_state = element->integer.value;
1196
1197         err = acpi_extract_power_resources(package, 2, &wakeup->resources);
1198         if (err)
1199                 goto out;
1200
1201         if (!list_empty(&wakeup->resources)) {
1202                 int sleep_state;
1203
1204                 err = acpi_power_wakeup_list_init(&wakeup->resources,
1205                                                   &sleep_state);
1206                 if (err) {
1207                         acpi_handle_warn(handle, "Retrieving current states "
1208                                          "of wakeup power resources failed\n");
1209                         acpi_power_resources_list_free(&wakeup->resources);
1210                         goto out;
1211                 }
1212                 if (sleep_state < wakeup->sleep_state) {
1213                         acpi_handle_warn(handle, "Overriding _PRW sleep state "
1214                                          "(S%d) by S%d from power resources\n",
1215                                          (int)wakeup->sleep_state, sleep_state);
1216                         wakeup->sleep_state = sleep_state;
1217                 }
1218         }
1219         acpi_setup_gpe_for_wake(handle, wakeup->gpe_device, wakeup->gpe_number);
1220
1221  out:
1222         kfree(buffer.pointer);
1223         return err;
1224 }
1225
1226 static void acpi_bus_set_run_wake_flags(struct acpi_device *device)
1227 {
1228         struct acpi_device_id button_device_ids[] = {
1229                 {"PNP0C0C", 0},
1230                 {"PNP0C0D", 0},
1231                 {"PNP0C0E", 0},
1232                 {"", 0},
1233         };
1234         acpi_status status;
1235         acpi_event_status event_status;
1236
1237         device->wakeup.flags.notifier_present = 0;
1238
1239         /* Power button, Lid switch always enable wakeup */
1240         if (!acpi_match_device_ids(device, button_device_ids)) {
1241                 device->wakeup.flags.run_wake = 1;
1242                 if (!acpi_match_device_ids(device, &button_device_ids[1])) {
1243                         /* Do not use Lid/sleep button for S5 wakeup */
1244                         if (device->wakeup.sleep_state == ACPI_STATE_S5)
1245                                 device->wakeup.sleep_state = ACPI_STATE_S4;
1246                 }
1247                 device_set_wakeup_capable(&device->dev, true);
1248                 return;
1249         }
1250
1251         status = acpi_get_gpe_status(device->wakeup.gpe_device,
1252                                         device->wakeup.gpe_number,
1253                                                 &event_status);
1254         if (status == AE_OK)
1255                 device->wakeup.flags.run_wake =
1256                                 !!(event_status & ACPI_EVENT_FLAG_HANDLE);
1257 }
1258
1259 static void acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
1260 {
1261         int err;
1262
1263         /* Presence of _PRW indicates wake capable */
1264         if (!acpi_has_method(device->handle, "_PRW"))
1265                 return;
1266
1267         err = acpi_bus_extract_wakeup_device_power_package(device->handle,
1268                                                            &device->wakeup);
1269         if (err) {
1270                 dev_err(&device->dev, "_PRW evaluation error: %d\n", err);
1271                 return;
1272         }
1273
1274         device->wakeup.flags.valid = 1;
1275         device->wakeup.prepare_count = 0;
1276         acpi_bus_set_run_wake_flags(device);
1277         /* Call _PSW/_DSW object to disable its ability to wake the sleeping
1278          * system for the ACPI device with the _PRW object.
1279          * The _PSW object is depreciated in ACPI 3.0 and is replaced by _DSW.
1280          * So it is necessary to call _DSW object first. Only when it is not
1281          * present will the _PSW object used.
1282          */
1283         err = acpi_device_sleep_wake(device, 0, 0, 0);
1284         if (err)
1285                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1286                                 "error in _DSW or _PSW evaluation\n"));
1287 }
1288
1289 static void acpi_bus_init_power_state(struct acpi_device *device, int state)
1290 {
1291         struct acpi_device_power_state *ps = &device->power.states[state];
1292         char pathname[5] = { '_', 'P', 'R', '0' + state, '\0' };
1293         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1294         acpi_status status;
1295
1296         INIT_LIST_HEAD(&ps->resources);
1297
1298         /* Evaluate "_PRx" to get referenced power resources */
1299         status = acpi_evaluate_object(device->handle, pathname, NULL, &buffer);
1300         if (ACPI_SUCCESS(status)) {
1301                 union acpi_object *package = buffer.pointer;
1302
1303                 if (buffer.length && package
1304                     && package->type == ACPI_TYPE_PACKAGE
1305                     && package->package.count) {
1306                         int err = acpi_extract_power_resources(package, 0,
1307                                                                &ps->resources);
1308                         if (!err)
1309                                 device->power.flags.power_resources = 1;
1310                 }
1311                 ACPI_FREE(buffer.pointer);
1312         }
1313
1314         /* Evaluate "_PSx" to see if we can do explicit sets */
1315         pathname[2] = 'S';
1316         if (acpi_has_method(device->handle, pathname))
1317                 ps->flags.explicit_set = 1;
1318
1319         /*
1320          * State is valid if there are means to put the device into it.
1321          * D3hot is only valid if _PR3 present.
1322          */
1323         if (!list_empty(&ps->resources)
1324             || (ps->flags.explicit_set && state < ACPI_STATE_D3_HOT)) {
1325                 ps->flags.valid = 1;
1326                 ps->flags.os_accessible = 1;
1327         }
1328
1329         ps->power = -1;         /* Unknown - driver assigned */
1330         ps->latency = -1;       /* Unknown - driver assigned */
1331 }
1332
1333 static void acpi_bus_get_power_flags(struct acpi_device *device)
1334 {
1335         u32 i;
1336
1337         /* Presence of _PS0|_PR0 indicates 'power manageable' */
1338         if (!acpi_has_method(device->handle, "_PS0") &&
1339             !acpi_has_method(device->handle, "_PR0"))
1340                 return;
1341
1342         device->flags.power_manageable = 1;
1343
1344         /*
1345          * Power Management Flags
1346          */
1347         if (acpi_has_method(device->handle, "_PSC"))
1348                 device->power.flags.explicit_get = 1;
1349         if (acpi_has_method(device->handle, "_IRC"))
1350                 device->power.flags.inrush_current = 1;
1351
1352         /*
1353          * Enumerate supported power management states
1354          */
1355         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++)
1356                 acpi_bus_init_power_state(device, i);
1357
1358         INIT_LIST_HEAD(&device->power.states[ACPI_STATE_D3_COLD].resources);
1359
1360         /* Set defaults for D0 and D3 states (always valid) */
1361         device->power.states[ACPI_STATE_D0].flags.valid = 1;
1362         device->power.states[ACPI_STATE_D0].power = 100;
1363         device->power.states[ACPI_STATE_D3_COLD].flags.valid = 1;
1364         device->power.states[ACPI_STATE_D3_COLD].power = 0;
1365
1366         /* Set D3cold's explicit_set flag if _PS3 exists. */
1367         if (device->power.states[ACPI_STATE_D3_HOT].flags.explicit_set)
1368                 device->power.states[ACPI_STATE_D3_COLD].flags.explicit_set = 1;
1369
1370         /* Presence of _PS3 or _PRx means we can put the device into D3 cold */
1371         if (device->power.states[ACPI_STATE_D3_HOT].flags.explicit_set ||
1372                         device->power.flags.power_resources)
1373                 device->power.states[ACPI_STATE_D3_COLD].flags.os_accessible = 1;
1374
1375         if (acpi_bus_init_power(device)) {
1376                 acpi_free_power_resources_lists(device);
1377                 device->flags.power_manageable = 0;
1378         }
1379 }
1380
1381 static void acpi_bus_get_flags(struct acpi_device *device)
1382 {
1383         /* Presence of _STA indicates 'dynamic_status' */
1384         if (acpi_has_method(device->handle, "_STA"))
1385                 device->flags.dynamic_status = 1;
1386
1387         /* Presence of _RMV indicates 'removable' */
1388         if (acpi_has_method(device->handle, "_RMV"))
1389                 device->flags.removable = 1;
1390
1391         /* Presence of _EJD|_EJ0 indicates 'ejectable' */
1392         if (acpi_has_method(device->handle, "_EJD") ||
1393             acpi_has_method(device->handle, "_EJ0"))
1394                 device->flags.ejectable = 1;
1395 }
1396
1397 static void acpi_device_get_busid(struct acpi_device *device)
1398 {
1399         char bus_id[5] = { '?', 0 };
1400         struct acpi_buffer buffer = { sizeof(bus_id), bus_id };
1401         int i = 0;
1402
1403         /*
1404          * Bus ID
1405          * ------
1406          * The device's Bus ID is simply the object name.
1407          * TBD: Shouldn't this value be unique (within the ACPI namespace)?
1408          */
1409         if (ACPI_IS_ROOT_DEVICE(device)) {
1410                 strcpy(device->pnp.bus_id, "ACPI");
1411                 return;
1412         }
1413
1414         switch (device->device_type) {
1415         case ACPI_BUS_TYPE_POWER_BUTTON:
1416                 strcpy(device->pnp.bus_id, "PWRF");
1417                 break;
1418         case ACPI_BUS_TYPE_SLEEP_BUTTON:
1419                 strcpy(device->pnp.bus_id, "SLPF");
1420                 break;
1421         default:
1422                 acpi_get_name(device->handle, ACPI_SINGLE_NAME, &buffer);
1423                 /* Clean up trailing underscores (if any) */
1424                 for (i = 3; i > 1; i--) {
1425                         if (bus_id[i] == '_')
1426                                 bus_id[i] = '\0';
1427                         else
1428                                 break;
1429                 }
1430                 strcpy(device->pnp.bus_id, bus_id);
1431                 break;
1432         }
1433 }
1434
1435 /*
1436  * acpi_ata_match - see if an acpi object is an ATA device
1437  *
1438  * If an acpi object has one of the ACPI ATA methods defined,
1439  * then we can safely call it an ATA device.
1440  */
1441 bool acpi_ata_match(acpi_handle handle)
1442 {
1443         return acpi_has_method(handle, "_GTF") ||
1444                acpi_has_method(handle, "_GTM") ||
1445                acpi_has_method(handle, "_STM") ||
1446                acpi_has_method(handle, "_SDD");
1447 }
1448
1449 /*
1450  * acpi_bay_match - see if an acpi object is an ejectable driver bay
1451  *
1452  * If an acpi object is ejectable and has one of the ACPI ATA methods defined,
1453  * then we can safely call it an ejectable drive bay
1454  */
1455 bool acpi_bay_match(acpi_handle handle)
1456 {
1457         acpi_handle phandle;
1458
1459         if (!acpi_has_method(handle, "_EJ0"))
1460                 return false;
1461         if (acpi_ata_match(handle))
1462                 return true;
1463         if (ACPI_FAILURE(acpi_get_parent(handle, &phandle)))
1464                 return false;
1465
1466         return acpi_ata_match(phandle);
1467 }
1468
1469 /*
1470  * acpi_dock_match - see if an acpi object has a _DCK method
1471  */
1472 bool acpi_dock_match(acpi_handle handle)
1473 {
1474         return acpi_has_method(handle, "_DCK");
1475 }
1476
1477 const char *acpi_device_hid(struct acpi_device *device)
1478 {
1479         struct acpi_hardware_id *hid;
1480
1481         if (list_empty(&device->pnp.ids))
1482                 return dummy_hid;
1483
1484         hid = list_first_entry(&device->pnp.ids, struct acpi_hardware_id, list);
1485         return hid->id;
1486 }
1487 EXPORT_SYMBOL(acpi_device_hid);
1488
1489 static void acpi_add_id(struct acpi_device_pnp *pnp, const char *dev_id)
1490 {
1491         struct acpi_hardware_id *id;
1492
1493         id = kmalloc(sizeof(*id), GFP_KERNEL);
1494         if (!id)
1495                 return;
1496
1497         id->id = kstrdup(dev_id, GFP_KERNEL);
1498         if (!id->id) {
1499                 kfree(id);
1500                 return;
1501         }
1502
1503         list_add_tail(&id->list, &pnp->ids);
1504         pnp->type.hardware_id = 1;
1505 }
1506
1507 /*
1508  * Old IBM workstations have a DSDT bug wherein the SMBus object
1509  * lacks the SMBUS01 HID and the methods do not have the necessary "_"
1510  * prefix.  Work around this.
1511  */
1512 static bool acpi_ibm_smbus_match(acpi_handle handle)
1513 {
1514         char node_name[ACPI_PATH_SEGMENT_LENGTH];
1515         struct acpi_buffer path = { sizeof(node_name), node_name };
1516
1517         if (!dmi_name_in_vendors("IBM"))
1518                 return false;
1519
1520         /* Look for SMBS object */
1521         if (ACPI_FAILURE(acpi_get_name(handle, ACPI_SINGLE_NAME, &path)) ||
1522             strcmp("SMBS", path.pointer))
1523                 return false;
1524
1525         /* Does it have the necessary (but misnamed) methods? */
1526         if (acpi_has_method(handle, "SBI") &&
1527             acpi_has_method(handle, "SBR") &&
1528             acpi_has_method(handle, "SBW"))
1529                 return true;
1530
1531         return false;
1532 }
1533
1534 static void acpi_set_pnp_ids(acpi_handle handle, struct acpi_device_pnp *pnp,
1535                                 int device_type)
1536 {
1537         acpi_status status;
1538         struct acpi_device_info *info;
1539         struct acpi_pnp_device_id_list *cid_list;
1540         int i;
1541
1542         switch (device_type) {
1543         case ACPI_BUS_TYPE_DEVICE:
1544                 if (handle == ACPI_ROOT_OBJECT) {
1545                         acpi_add_id(pnp, ACPI_SYSTEM_HID);
1546                         break;
1547                 }
1548
1549                 status = acpi_get_object_info(handle, &info);
1550                 if (ACPI_FAILURE(status)) {
1551                         pr_err(PREFIX "%s: Error reading device info\n",
1552                                         __func__);
1553                         return;
1554                 }
1555
1556                 if (info->valid & ACPI_VALID_HID)
1557                         acpi_add_id(pnp, info->hardware_id.string);
1558                 if (info->valid & ACPI_VALID_CID) {
1559                         cid_list = &info->compatible_id_list;
1560                         for (i = 0; i < cid_list->count; i++)
1561                                 acpi_add_id(pnp, cid_list->ids[i].string);
1562                 }
1563                 if (info->valid & ACPI_VALID_ADR) {
1564                         pnp->bus_address = info->address;
1565                         pnp->type.bus_address = 1;
1566                 }
1567                 if (info->valid & ACPI_VALID_UID)
1568                         pnp->unique_id = kstrdup(info->unique_id.string,
1569                                                         GFP_KERNEL);
1570
1571                 kfree(info);
1572
1573                 /*
1574                  * Some devices don't reliably have _HIDs & _CIDs, so add
1575                  * synthetic HIDs to make sure drivers can find them.
1576                  */
1577                 if (acpi_is_video_device(handle))
1578                         acpi_add_id(pnp, ACPI_VIDEO_HID);
1579                 else if (acpi_bay_match(handle))
1580                         acpi_add_id(pnp, ACPI_BAY_HID);
1581                 else if (acpi_dock_match(handle))
1582                         acpi_add_id(pnp, ACPI_DOCK_HID);
1583                 else if (acpi_ibm_smbus_match(handle))
1584                         acpi_add_id(pnp, ACPI_SMBUS_IBM_HID);
1585                 else if (list_empty(&pnp->ids) && handle == ACPI_ROOT_OBJECT) {
1586                         acpi_add_id(pnp, ACPI_BUS_HID); /* \_SB, LNXSYBUS */
1587                         strcpy(pnp->device_name, ACPI_BUS_DEVICE_NAME);
1588                         strcpy(pnp->device_class, ACPI_BUS_CLASS);
1589                 }
1590
1591                 break;
1592         case ACPI_BUS_TYPE_POWER:
1593                 acpi_add_id(pnp, ACPI_POWER_HID);
1594                 break;
1595         case ACPI_BUS_TYPE_PROCESSOR:
1596                 acpi_add_id(pnp, ACPI_PROCESSOR_OBJECT_HID);
1597                 break;
1598         case ACPI_BUS_TYPE_THERMAL:
1599                 acpi_add_id(pnp, ACPI_THERMAL_HID);
1600                 break;
1601         case ACPI_BUS_TYPE_POWER_BUTTON:
1602                 acpi_add_id(pnp, ACPI_BUTTON_HID_POWERF);
1603                 break;
1604         case ACPI_BUS_TYPE_SLEEP_BUTTON:
1605                 acpi_add_id(pnp, ACPI_BUTTON_HID_SLEEPF);
1606                 break;
1607         }
1608 }
1609
1610 void acpi_free_pnp_ids(struct acpi_device_pnp *pnp)
1611 {
1612         struct acpi_hardware_id *id, *tmp;
1613
1614         list_for_each_entry_safe(id, tmp, &pnp->ids, list) {
1615                 kfree(id->id);
1616                 kfree(id);
1617         }
1618         kfree(pnp->unique_id);
1619 }
1620
1621 void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,
1622                              int type, unsigned long long sta)
1623 {
1624         INIT_LIST_HEAD(&device->pnp.ids);
1625         device->device_type = type;
1626         device->handle = handle;
1627         device->parent = acpi_bus_get_parent(handle);
1628         STRUCT_TO_INT(device->status) = sta;
1629         acpi_device_get_busid(device);
1630         acpi_set_pnp_ids(handle, &device->pnp, type);
1631         acpi_bus_get_flags(device);
1632         device->flags.match_driver = false;
1633         device_initialize(&device->dev);
1634         dev_set_uevent_suppress(&device->dev, true);
1635 }
1636
1637 void acpi_device_add_finalize(struct acpi_device *device)
1638 {
1639         dev_set_uevent_suppress(&device->dev, false);
1640         kobject_uevent(&device->dev.kobj, KOBJ_ADD);
1641 }
1642
1643 static int acpi_add_single_object(struct acpi_device **child,
1644                                   acpi_handle handle, int type,
1645                                   unsigned long long sta)
1646 {
1647         int result;
1648         struct acpi_device *device;
1649         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1650
1651         device = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
1652         if (!device) {
1653                 printk(KERN_ERR PREFIX "Memory allocation error\n");
1654                 return -ENOMEM;
1655         }
1656
1657         acpi_init_device_object(device, handle, type, sta);
1658         acpi_bus_get_power_flags(device);
1659         acpi_bus_get_wakeup_device_flags(device);
1660
1661         result = acpi_device_add(device, acpi_device_release);
1662         if (result) {
1663                 acpi_device_release(&device->dev);
1664                 return result;
1665         }
1666
1667         acpi_power_add_remove_device(device, true);
1668         acpi_device_add_finalize(device);
1669         acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
1670         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Added %s [%s] parent %s\n",
1671                 dev_name(&device->dev), (char *) buffer.pointer,
1672                 device->parent ? dev_name(&device->parent->dev) : "(null)"));
1673         kfree(buffer.pointer);
1674         *child = device;
1675         return 0;
1676 }
1677
1678 static int acpi_bus_type_and_status(acpi_handle handle, int *type,
1679                                     unsigned long long *sta)
1680 {
1681         acpi_status status;
1682         acpi_object_type acpi_type;
1683
1684         status = acpi_get_type(handle, &acpi_type);
1685         if (ACPI_FAILURE(status))
1686                 return -ENODEV;
1687
1688         switch (acpi_type) {
1689         case ACPI_TYPE_ANY:             /* for ACPI_ROOT_OBJECT */
1690         case ACPI_TYPE_DEVICE:
1691                 *type = ACPI_BUS_TYPE_DEVICE;
1692                 status = acpi_bus_get_status_handle(handle, sta);
1693                 if (ACPI_FAILURE(status))
1694                         return -ENODEV;
1695                 break;
1696         case ACPI_TYPE_PROCESSOR:
1697                 *type = ACPI_BUS_TYPE_PROCESSOR;
1698                 status = acpi_bus_get_status_handle(handle, sta);
1699                 if (ACPI_FAILURE(status))
1700                         return -ENODEV;
1701                 break;
1702         case ACPI_TYPE_THERMAL:
1703                 *type = ACPI_BUS_TYPE_THERMAL;
1704                 *sta = ACPI_STA_DEFAULT;
1705                 break;
1706         case ACPI_TYPE_POWER:
1707                 *type = ACPI_BUS_TYPE_POWER;
1708                 *sta = ACPI_STA_DEFAULT;
1709                 break;
1710         default:
1711                 return -ENODEV;
1712         }
1713
1714         return 0;
1715 }
1716
1717 static bool acpi_scan_handler_matching(struct acpi_scan_handler *handler,
1718                                        char *idstr,
1719                                        const struct acpi_device_id **matchid)
1720 {
1721         const struct acpi_device_id *devid;
1722
1723         for (devid = handler->ids; devid->id[0]; devid++)
1724                 if (!strcmp((char *)devid->id, idstr)) {
1725                         if (matchid)
1726                                 *matchid = devid;
1727
1728                         return true;
1729                 }
1730
1731         return false;
1732 }
1733
1734 static struct acpi_scan_handler *acpi_scan_match_handler(char *idstr,
1735                                         const struct acpi_device_id **matchid)
1736 {
1737         struct acpi_scan_handler *handler;
1738
1739         list_for_each_entry(handler, &acpi_scan_handlers_list, list_node)
1740                 if (acpi_scan_handler_matching(handler, idstr, matchid))
1741                         return handler;
1742
1743         return NULL;
1744 }
1745
1746 void acpi_scan_hotplug_enabled(struct acpi_hotplug_profile *hotplug, bool val)
1747 {
1748         if (!!hotplug->enabled == !!val)
1749                 return;
1750
1751         mutex_lock(&acpi_scan_lock);
1752
1753         hotplug->enabled = val;
1754
1755         mutex_unlock(&acpi_scan_lock);
1756 }
1757
1758 static void acpi_scan_init_hotplug(acpi_handle handle, int type)
1759 {
1760         struct acpi_device_pnp pnp = {};
1761         struct acpi_hardware_id *hwid;
1762         struct acpi_scan_handler *handler;
1763
1764         INIT_LIST_HEAD(&pnp.ids);
1765         acpi_set_pnp_ids(handle, &pnp, type);
1766
1767         if (!pnp.type.hardware_id)
1768                 goto out;
1769
1770         /*
1771          * This relies on the fact that acpi_install_notify_handler() will not
1772          * install the same notify handler routine twice for the same handle.
1773          */
1774         list_for_each_entry(hwid, &pnp.ids, list) {
1775                 handler = acpi_scan_match_handler(hwid->id, NULL);
1776                 if (handler && !handler->hotplug.ignore) {
1777                         acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
1778                                         acpi_hotplug_notify_cb, handler);
1779                         break;
1780                 }
1781         }
1782
1783 out:
1784         acpi_free_pnp_ids(&pnp);
1785 }
1786
1787 static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl_not_used,
1788                                       void *not_used, void **return_value)
1789 {
1790         struct acpi_device *device = NULL;
1791         int type;
1792         unsigned long long sta;
1793         int result;
1794
1795         acpi_bus_get_device(handle, &device);
1796         if (device)
1797                 goto out;
1798
1799         result = acpi_bus_type_and_status(handle, &type, &sta);
1800         if (result)
1801                 return AE_OK;
1802
1803         if (type == ACPI_BUS_TYPE_POWER) {
1804                 acpi_add_power_resource(handle);
1805                 return AE_OK;
1806         }
1807
1808         acpi_scan_init_hotplug(handle, type);
1809
1810         if (!(sta & ACPI_STA_DEVICE_PRESENT) &&
1811             !(sta & ACPI_STA_DEVICE_FUNCTIONING)) {
1812                 struct acpi_device_wakeup wakeup;
1813
1814                 if (acpi_has_method(handle, "_PRW")) {
1815                         acpi_bus_extract_wakeup_device_power_package(handle,
1816                                                                      &wakeup);
1817                         acpi_power_resources_list_free(&wakeup.resources);
1818                 }
1819                 return AE_CTRL_DEPTH;
1820         }
1821
1822         acpi_add_single_object(&device, handle, type, sta);
1823         if (!device)
1824                 return AE_CTRL_DEPTH;
1825
1826  out:
1827         if (!*return_value)
1828                 *return_value = device;
1829
1830         return AE_OK;
1831 }
1832
1833 static int acpi_scan_attach_handler(struct acpi_device *device)
1834 {
1835         struct acpi_hardware_id *hwid;
1836         int ret = 0;
1837
1838         list_for_each_entry(hwid, &device->pnp.ids, list) {
1839                 const struct acpi_device_id *devid;
1840                 struct acpi_scan_handler *handler;
1841
1842                 handler = acpi_scan_match_handler(hwid->id, &devid);
1843                 if (handler) {
1844                         ret = handler->attach(device, devid);
1845                         if (ret > 0) {
1846                                 device->handler = handler;
1847                                 break;
1848                         } else if (ret < 0) {
1849                                 break;
1850                         }
1851                 }
1852         }
1853         return ret;
1854 }
1855
1856 static acpi_status acpi_bus_device_attach(acpi_handle handle, u32 lvl_not_used,
1857                                           void *not_used, void **ret_not_used)
1858 {
1859         struct acpi_device *device;
1860         unsigned long long sta_not_used;
1861         int ret;
1862
1863         /*
1864          * Ignore errors ignored by acpi_bus_check_add() to avoid terminating
1865          * namespace walks prematurely.
1866          */
1867         if (acpi_bus_type_and_status(handle, &ret, &sta_not_used))
1868                 return AE_OK;
1869
1870         if (acpi_bus_get_device(handle, &device))
1871                 return AE_CTRL_DEPTH;
1872
1873         if (device->handler)
1874                 return AE_OK;
1875
1876         ret = acpi_scan_attach_handler(device);
1877         if (ret < 0)
1878                 return AE_CTRL_DEPTH;
1879
1880         device->flags.match_driver = true;
1881         if (ret > 0)
1882                 return AE_OK;
1883
1884         ret = device_attach(&device->dev);
1885         return ret >= 0 ? AE_OK : AE_CTRL_DEPTH;
1886 }
1887
1888 /**
1889  * acpi_bus_scan - Add ACPI device node objects in a given namespace scope.
1890  * @handle: Root of the namespace scope to scan.
1891  *
1892  * Scan a given ACPI tree (probably recently hot-plugged) and create and add
1893  * found devices.
1894  *
1895  * If no devices were found, -ENODEV is returned, but it does not mean that
1896  * there has been a real error.  There just have been no suitable ACPI objects
1897  * in the table trunk from which the kernel could create a device and add an
1898  * appropriate driver.
1899  *
1900  * Must be called under acpi_scan_lock.
1901  */
1902 int acpi_bus_scan(acpi_handle handle)
1903 {
1904         void *device = NULL;
1905         int error = 0;
1906
1907         if (ACPI_SUCCESS(acpi_bus_check_add(handle, 0, NULL, &device)))
1908                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
1909                                     acpi_bus_check_add, NULL, NULL, &device);
1910
1911         if (!device)
1912                 error = -ENODEV;
1913         else if (ACPI_SUCCESS(acpi_bus_device_attach(handle, 0, NULL, NULL)))
1914                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
1915                                     acpi_bus_device_attach, NULL, NULL, NULL);
1916
1917         return error;
1918 }
1919 EXPORT_SYMBOL(acpi_bus_scan);
1920
1921 static acpi_status acpi_bus_device_detach(acpi_handle handle, u32 lvl_not_used,
1922                                           void *not_used, void **ret_not_used)
1923 {
1924         struct acpi_device *device = NULL;
1925
1926         if (!acpi_bus_get_device(handle, &device)) {
1927                 struct acpi_scan_handler *dev_handler = device->handler;
1928
1929                 if (dev_handler) {
1930                         if (dev_handler->detach)
1931                                 dev_handler->detach(device);
1932
1933                         device->handler = NULL;
1934                 } else {
1935                         device_release_driver(&device->dev);
1936                 }
1937         }
1938         return AE_OK;
1939 }
1940
1941 static acpi_status acpi_bus_remove(acpi_handle handle, u32 lvl_not_used,
1942                                    void *not_used, void **ret_not_used)
1943 {
1944         struct acpi_device *device = NULL;
1945
1946         if (!acpi_bus_get_device(handle, &device))
1947                 acpi_device_unregister(device);
1948
1949         return AE_OK;
1950 }
1951
1952 /**
1953  * acpi_bus_trim - Remove ACPI device node and all of its descendants
1954  * @start: Root of the ACPI device nodes subtree to remove.
1955  *
1956  * Must be called under acpi_scan_lock.
1957  */
1958 void acpi_bus_trim(struct acpi_device *start)
1959 {
1960         /*
1961          * Execute acpi_bus_device_detach() as a post-order callback to detach
1962          * all ACPI drivers from the device nodes being removed.
1963          */
1964         acpi_walk_namespace(ACPI_TYPE_ANY, start->handle, ACPI_UINT32_MAX, NULL,
1965                             acpi_bus_device_detach, NULL, NULL);
1966         acpi_bus_device_detach(start->handle, 0, NULL, NULL);
1967         /*
1968          * Execute acpi_bus_remove() as a post-order callback to remove device
1969          * nodes in the given namespace scope.
1970          */
1971         acpi_walk_namespace(ACPI_TYPE_ANY, start->handle, ACPI_UINT32_MAX, NULL,
1972                             acpi_bus_remove, NULL, NULL);
1973         acpi_bus_remove(start->handle, 0, NULL, NULL);
1974 }
1975 EXPORT_SYMBOL_GPL(acpi_bus_trim);
1976
1977 static int acpi_bus_scan_fixed(void)
1978 {
1979         int result = 0;
1980
1981         /*
1982          * Enumerate all fixed-feature devices.
1983          */
1984         if (!(acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON)) {
1985                 struct acpi_device *device = NULL;
1986
1987                 result = acpi_add_single_object(&device, NULL,
1988                                                 ACPI_BUS_TYPE_POWER_BUTTON,
1989                                                 ACPI_STA_DEFAULT);
1990                 if (result)
1991                         return result;
1992
1993                 device->flags.match_driver = true;
1994                 result = device_attach(&device->dev);
1995                 if (result < 0)
1996                         return result;
1997
1998                 device_init_wakeup(&device->dev, true);
1999         }
2000
2001         if (!(acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON)) {
2002                 struct acpi_device *device = NULL;
2003
2004                 result = acpi_add_single_object(&device, NULL,
2005                                                 ACPI_BUS_TYPE_SLEEP_BUTTON,
2006                                                 ACPI_STA_DEFAULT);
2007                 if (result)
2008                         return result;
2009
2010                 device->flags.match_driver = true;
2011                 result = device_attach(&device->dev);
2012         }
2013
2014         return result < 0 ? result : 0;
2015 }
2016
2017 int __init acpi_scan_init(void)
2018 {
2019         int result;
2020
2021         result = bus_register(&acpi_bus_type);
2022         if (result) {
2023                 /* We don't want to quit even if we failed to add suspend/resume */
2024                 printk(KERN_ERR PREFIX "Could not register bus type\n");
2025         }
2026
2027         acpi_pci_root_init();
2028         acpi_pci_link_init();
2029         acpi_processor_init();
2030         acpi_platform_init();
2031         acpi_lpss_init();
2032         acpi_cmos_rtc_init();
2033         acpi_container_init();
2034         acpi_memory_hotplug_init();
2035         acpi_dock_init();
2036
2037         mutex_lock(&acpi_scan_lock);
2038         /*
2039          * Enumerate devices in the ACPI namespace.
2040          */
2041         result = acpi_bus_scan(ACPI_ROOT_OBJECT);
2042         if (result)
2043                 goto out;
2044
2045         result = acpi_bus_get_device(ACPI_ROOT_OBJECT, &acpi_root);
2046         if (result)
2047                 goto out;
2048
2049         result = acpi_bus_scan_fixed();
2050         if (result) {
2051                 acpi_device_unregister(acpi_root);
2052                 goto out;
2053         }
2054
2055         acpi_update_all_gpes();
2056
2057         acpi_pci_root_hp_init();
2058
2059  out:
2060         mutex_unlock(&acpi_scan_lock);
2061         return result;
2062 }