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