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 <asm/pgtable.h>
  18
  19 #include "internal.h"
  20
  21 #define _COMPONENT              ACPI_BUS_COMPONENT
  22 ACPI_MODULE_NAME("scan");
  23 extern struct acpi_device *acpi_root;
  24
  25 #define ACPI_BUS_CLASS                  "system_bus"
  26 #define ACPI_BUS_HID                    "LNXSYBUS"
  27 #define ACPI_BUS_DEVICE_NAME            "System Bus"
  28
  29 #define ACPI_IS_ROOT_DEVICE(device)    (!(device)->parent)
  30
  31 #define INVALID_ACPI_HANDLE     ((acpi_handle)empty_zero_page)
  32
  33 /*
  34  * If set, devices will be hot-removed even if they cannot be put offline
  35  * gracefully (from the kernel's standpoint).
  36  */
  37 bool acpi_force_hot_remove;
  38
  39 static const char *dummy_hid = "device";
  40
  41 static LIST_HEAD(acpi_bus_id_list);
  42 static DEFINE_MUTEX(acpi_scan_lock);
  43 static LIST_HEAD(acpi_scan_handlers_list);
  44 DEFINE_MUTEX(acpi_device_lock);
  45 LIST_HEAD(acpi_wakeup_device_list);
  46
  47 struct acpi_device_bus_id{
  48         char bus_id[15];
  49         unsigned int instance_no;
  50         struct list_head node;
  51 };
  52
  53 void acpi_scan_lock_acquire(void)
  54 {
  55         mutex_lock(&acpi_scan_lock);
  56 }
  57 EXPORT_SYMBOL_GPL(acpi_scan_lock_acquire);
  58
  59 void acpi_scan_lock_release(void)
  60 {
  61         mutex_unlock(&acpi_scan_lock);
  62 }
  63 EXPORT_SYMBOL_GPL(acpi_scan_lock_release);
  64
  65 int acpi_scan_add_handler(struct acpi_scan_handler *handler)
  66 {
  67         if (!handler || !handler->attach)
  68                 return -EINVAL;
  69
  70         list_add_tail(&handler->list_node, &acpi_scan_handlers_list);
  71         return 0;
  72 }
  73
  74 int acpi_scan_add_handler_with_hotplug(struct acpi_scan_handler *handler,
  75                                        const char *hotplug_profile_name)
  76 {
  77         int error;
  78
  79         error = acpi_scan_add_handler(handler);
  80         if (error)
  81                 return error;
  82
  83         acpi_sysfs_add_hotplug_profile(&handler->hotplug, hotplug_profile_name);
  84         return 0;
  85 }
  86
  87 /*
  88  * Creates hid/cid(s) string needed for modalias and uevent
  89  * e.g. on a device with hid:IBM0001 and cid:ACPI0001 you get:
  90  * char *modalias: "acpi:IBM0001:ACPI0001"
  91 */
  92 static int create_modalias(struct acpi_device *acpi_dev, char *modalias,
  93                            int size)
  94 {
  95         int len;
  96         int count;
  97         struct acpi_hardware_id *id;
  98
  99         if (list_empty(&acpi_dev->pnp.ids))
 100                 return 0;
 101
 102         len = snprintf(modalias, size, "acpi:");
 103         size -= len;
 104
 105         list_for_each_entry(id, &acpi_dev->pnp.ids, list) {
 106                 count = snprintf(&modalias[len], size, "%s:", id->id);
 107                 if (count < 0 || count >= size)
 108                         return -EINVAL;
 109                 len += count;
 110                 size -= count;
 111         }
 112
 113         modalias[len] = '\0';
 114         return len;
 115 }
 116
 117 static ssize_t
 118 acpi_device_modalias_show(struct device *dev, struct device_attribute *attr, char *buf) {
 119         struct acpi_device *acpi_dev = to_acpi_device(dev);
 120         int len;
 121
 122         /* Device has no HID and no CID or string is >1024 */
 123         len = create_modalias(acpi_dev, buf, 1024);
 124         if (len <= 0)
 125                 return 0;
 126         buf[len++] = '\n';
 127         return len;
 128 }
 129 static DEVICE_ATTR(modalias, 0444, acpi_device_modalias_show, NULL);
 130
 131 static acpi_status acpi_bus_offline(acpi_handle handle, u32 lvl, void *data,
 132                                     void **ret_p)
 133 {
 134         struct acpi_device *device = NULL;
 135         struct acpi_device_physical_node *pn;
 136         bool second_pass = (bool)data;
 137         acpi_status status = AE_OK;
 138
 139         if (acpi_bus_get_device(handle, &device))
 140                 return AE_OK;
 141
 142         if (device->handler && !device->handler->hotplug.enabled) {
 143                 *ret_p = &device->dev;
 144                 return AE_SUPPORT;
 145         }
 146
 147         mutex_lock(&device->physical_node_lock);
 148
 149         list_for_each_entry(pn, &device->physical_node_list, node) {
 150                 int ret;
 151
 152                 if (second_pass) {
 153                         /* Skip devices offlined by the first pass. */
 154                         if (pn->put_online)
 155                                 continue;
 156                 } else {
 157                         pn->put_online = false;
 158                 }
 159                 ret = device_offline(pn->dev);
 160                 if (acpi_force_hot_remove)
 161                         continue;
 162
 163                 if (ret >= 0) {
 164                         pn->put_online = !ret;
 165                 } else {
 166                         *ret_p = pn->dev;
 167                         if (second_pass) {
 168                                 status = AE_ERROR;
 169                                 break;
 170                         }
 171                 }
 172         }
 173
 174         mutex_unlock(&device->physical_node_lock);
 175
 176         return status;
 177 }
 178
 179 static acpi_status acpi_bus_online(acpi_handle handle, u32 lvl, void *data,
 180                                    void **ret_p)
 181 {
 182         struct acpi_device *device = NULL;
 183         struct acpi_device_physical_node *pn;
 184
 185         if (acpi_bus_get_device(handle, &device))
 186                 return AE_OK;
 187
 188         mutex_lock(&device->physical_node_lock);
 189
 190         list_for_each_entry(pn, &device->physical_node_list, node)
 191                 if (pn->put_online) {
 192                         device_online(pn->dev);
 193                         pn->put_online = false;
 194                 }
 195
 196         mutex_unlock(&device->physical_node_lock);
 197
 198         return AE_OK;
 199 }
 200
 201 static int acpi_scan_hot_remove(struct acpi_device *device)
 202 {
 203         acpi_handle handle = device->handle;
 204         struct device *errdev;
 205         acpi_status status;
 206         unsigned long long sta;
 207
 208         /*
 209          * Carry out two passes here and ignore errors in the first pass,
 210          * because if the devices in question are memory blocks and
 211          * CONFIG_MEMCG is set, one of the blocks may hold data structures
 212          * that the other blocks depend on, but it is not known in advance which
 213          * block holds them.
 214          *
 215          * If the first pass is successful, the second one isn't needed, though.
 216          */
 217         errdev = NULL;
 218         status = acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
 219                                      NULL, acpi_bus_offline, (void *)false,
 220                                      (void **)&errdev);
 221         if (status == AE_SUPPORT) {
 222                 dev_warn(errdev, "Offline disabled.\n");
 223                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
 224                                     acpi_bus_online, NULL, NULL, NULL);
 225                 return -EPERM;
 226         }
 227         acpi_bus_offline(handle, 0, (void *)false, (void **)&errdev);
 228         if (errdev) {
 229                 errdev = NULL;
 230                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
 231                                     NULL, acpi_bus_offline, (void *)true,
 232                                     (void **)&errdev);
 233                 if (!errdev || acpi_force_hot_remove)
 234                         acpi_bus_offline(handle, 0, (void *)true,
 235                                          (void **)&errdev);
 236
 237                 if (errdev && !acpi_force_hot_remove) {
 238                         dev_warn(errdev, "Offline failed.\n");
 239                         acpi_bus_online(handle, 0, NULL, NULL);
 240                         acpi_walk_namespace(ACPI_TYPE_ANY, handle,
 241                                             ACPI_UINT32_MAX, acpi_bus_online,
 242                                             NULL, NULL, NULL);
 243                         return -EBUSY;
 244                 }
 245         }
 246
 247         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 248                 "Hot-removing device %s...\n", dev_name(&device->dev)));
 249
 250         acpi_bus_trim(device);
 251
 252         acpi_evaluate_lck(handle, 0);
 253         /*
 254          * TBD: _EJD support.
 255          */
 256         status = acpi_evaluate_ej0(handle);
 257         if (status == AE_NOT_FOUND)
 258                 return -ENODEV;
 259         else if (ACPI_FAILURE(status))
 260                 return -EIO;
 261
 262         /*
 263          * Verify if eject was indeed successful.  If not, log an error
 264          * message.  No need to call _OST since _EJ0 call was made OK.
 265          */
 266         status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
 267         if (ACPI_FAILURE(status)) {
 268                 acpi_handle_warn(handle,
 269                         "Status check after eject failed (0x%x)\n", status);
 270         } else if (sta & ACPI_STA_DEVICE_ENABLED) {
 271                 acpi_handle_warn(handle,
 272                         "Eject incomplete - status 0x%llx\n", sta);
 273         }
 274
 275         return 0;
 276 }
 277
 278 static int acpi_scan_device_not_present(struct acpi_device *adev)
 279 {
 280         if (!acpi_device_enumerated(adev)) {
 281                 dev_warn(&adev->dev, "Still not present\n");
 282                 return -EALREADY;
 283         }
 284         acpi_bus_trim(adev);
 285         return 0;
 286 }
 287
 288 static int acpi_scan_device_check(struct acpi_device *adev)
 289 {
 290         int error;
 291
 292         acpi_bus_get_status(adev);
 293         if (adev->status.present || adev->status.functional) {
 294                 /*
 295                  * This function is only called for device objects for which
 296                  * matching scan handlers exist.  The only situation in which
 297                  * the scan handler is not attached to this device object yet
 298                  * is when the device has just appeared (either it wasn't
 299                  * present at all before or it was removed and then added
 300                  * again).
 301                  */
 302                 if (adev->handler) {
 303                         dev_warn(&adev->dev, "Already enumerated\n");
 304                         return -EALREADY;
 305                 }
 306                 error = acpi_bus_scan(adev->handle);
 307                 if (error) {
 308                         dev_warn(&adev->dev, "Namespace scan failure\n");
 309                         return error;
 310                 }
 311                 if (!adev->handler) {
 312                         dev_warn(&adev->dev, "Enumeration failure\n");
 313                         error = -ENODEV;
 314                 }
 315         } else {
 316                 error = acpi_scan_device_not_present(adev);
 317         }
 318         return error;
 319 }
 320
 321 static int acpi_scan_bus_check(struct acpi_device *adev)
 322 {
 323         struct acpi_scan_handler *handler = adev->handler;
 324         struct acpi_device *child;
 325         int error;
 326
 327         acpi_bus_get_status(adev);
 328         if (!(adev->status.present || adev->status.functional)) {
 329                 acpi_scan_device_not_present(adev);
 330                 return 0;
 331         }
 332         if (handler && handler->hotplug.scan_dependent)
 333                 return handler->hotplug.scan_dependent(adev);
 334
 335         error = acpi_bus_scan(adev->handle);
 336         if (error) {
 337                 dev_warn(&adev->dev, "Namespace scan failure\n");
 338                 return error;
 339         }
 340         list_for_each_entry(child, &adev->children, node) {
 341                 error = acpi_scan_bus_check(child);
 342                 if (error)
 343                         return error;
 344         }
 345         return 0;
 346 }
 347
 348 static void acpi_device_hotplug(void *data, u32 src)
 349 {
 350         u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
 351         struct acpi_device *adev = data;
 352         int error;
 353
 354         lock_device_hotplug();
 355         mutex_lock(&acpi_scan_lock);
 356
 357         /*
 358          * The device object's ACPI handle cannot become invalid as long as we
 359          * are holding acpi_scan_lock, but it may have become invalid before
 360          * that lock was acquired.
 361          */
 362         if (adev->handle == INVALID_ACPI_HANDLE)
 363                 goto out;
 364
 365         switch (src) {
 366         case ACPI_NOTIFY_BUS_CHECK:
 367                 error = acpi_scan_bus_check(adev);
 368                 break;
 369         case ACPI_NOTIFY_DEVICE_CHECK:
 370                 error = acpi_scan_device_check(adev);
 371                 break;
 372         case ACPI_NOTIFY_EJECT_REQUEST:
 373         case ACPI_OST_EC_OSPM_EJECT:
 374                 error = acpi_scan_hot_remove(adev);
 375                 break;
 376         default:
 377                 error = -EINVAL;
 378                 break;
 379         }
 380         if (!error)
 381                 ost_code = ACPI_OST_SC_SUCCESS;
 382
 383  out:
 384         acpi_evaluate_hotplug_ost(adev->handle, src, ost_code, NULL);
 385         put_device(&adev->dev);
 386         mutex_unlock(&acpi_scan_lock);
 387         unlock_device_hotplug();
 388 }
 389
 390 static void acpi_hotplug_notify_cb(acpi_handle handle, u32 type, void *data)
 391 {
 392         u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
 393         struct acpi_scan_handler *handler = data;
 394         struct acpi_device *adev;
 395         acpi_status status;
 396
 397         if (acpi_bus_get_device(handle, &adev))
 398                 goto err_out;
 399
 400         switch (type) {
 401         case ACPI_NOTIFY_BUS_CHECK:
 402                 acpi_handle_debug(handle, "ACPI_NOTIFY_BUS_CHECK event\n");
 403                 break;
 404         case ACPI_NOTIFY_DEVICE_CHECK:
 405                 acpi_handle_debug(handle, "ACPI_NOTIFY_DEVICE_CHECK event\n");
 406                 break;
 407         case ACPI_NOTIFY_EJECT_REQUEST:
 408                 acpi_handle_debug(handle, "ACPI_NOTIFY_EJECT_REQUEST event\n");
 409                 if (!handler->hotplug.enabled) {
 410                         acpi_handle_err(handle, "Eject disabled\n");
 411                         ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
 412                         goto err_out;
 413                 }
 414                 acpi_evaluate_hotplug_ost(handle, ACPI_NOTIFY_EJECT_REQUEST,
 415                                           ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
 416                 break;
 417         default:
 418                 /* non-hotplug event; possibly handled by other handler */
 419                 return;
 420         }
 421         get_device(&adev->dev);
 422         status = acpi_hotplug_execute(acpi_device_hotplug, adev, type);
 423         if (ACPI_SUCCESS(status))
 424                 return;
 425
 426         put_device(&adev->dev);
 427
 428  err_out:
 429         acpi_evaluate_hotplug_ost(handle, type, ost_code, NULL);
 430 }
 431
 432 static ssize_t real_power_state_show(struct device *dev,
 433                                      struct device_attribute *attr, char *buf)
 434 {
 435         struct acpi_device *adev = to_acpi_device(dev);
 436         int state;
 437         int ret;
 438
 439         ret = acpi_device_get_power(adev, &state);
 440         if (ret)
 441                 return ret;
 442
 443         return sprintf(buf, "%s\n", acpi_power_state_string(state));
 444 }
 445
 446 static DEVICE_ATTR(real_power_state, 0444, real_power_state_show, NULL);
 447
 448 static ssize_t power_state_show(struct device *dev,
 449                                 struct device_attribute *attr, char *buf)
 450 {
 451         struct acpi_device *adev = to_acpi_device(dev);
 452
 453         return sprintf(buf, "%s\n", acpi_power_state_string(adev->power.state));
 454 }
 455
 456 static DEVICE_ATTR(power_state, 0444, power_state_show, NULL);
 457
 458 static ssize_t
 459 acpi_eject_store(struct device *d, struct device_attribute *attr,
 460                 const char *buf, size_t count)
 461 {
 462         struct acpi_device *acpi_device = to_acpi_device(d);
 463         acpi_object_type not_used;
 464         acpi_status status;
 465
 466         if (!count || buf[0] != '1')
 467                 return -EINVAL;
 468
 469         if ((!acpi_device->handler || !acpi_device->handler->hotplug.enabled)
 470             && !acpi_device->driver)
 471                 return -ENODEV;
 472
 473         status = acpi_get_type(acpi_device->handle, &not_used);
 474         if (ACPI_FAILURE(status) || !acpi_device->flags.ejectable)
 475                 return -ENODEV;
 476
 477         acpi_evaluate_hotplug_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,
 478                                   ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
 479         get_device(&acpi_device->dev);
 480         status = acpi_hotplug_execute(acpi_device_hotplug, acpi_device,
 481                                       ACPI_OST_EC_OSPM_EJECT);
 482         if (ACPI_SUCCESS(status))
 483                 return count;
 484
 485         put_device(&acpi_device->dev);
 486         acpi_evaluate_hotplug_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,
 487                                   ACPI_OST_SC_NON_SPECIFIC_FAILURE, NULL);
 488         return status == AE_NO_MEMORY ? -ENOMEM : -EAGAIN;
 489 }
 490
 491 static DEVICE_ATTR(eject, 0200, NULL, acpi_eject_store);
 492
 493 static ssize_t
 494 acpi_device_hid_show(struct device *dev, struct device_attribute *attr, char *buf) {
 495         struct acpi_device *acpi_dev = to_acpi_device(dev);
 496
 497         return sprintf(buf, "%s\n", acpi_device_hid(acpi_dev));
 498 }
 499 static DEVICE_ATTR(hid, 0444, acpi_device_hid_show, NULL);
 500
 501 static ssize_t acpi_device_uid_show(struct device *dev,
 502                                     struct device_attribute *attr, char *buf)
 503 {
 504         struct acpi_device *acpi_dev = to_acpi_device(dev);
 505
 506         return sprintf(buf, "%s\n", acpi_dev->pnp.unique_id);
 507 }
 508 static DEVICE_ATTR(uid, 0444, acpi_device_uid_show, NULL);
 509
 510 static ssize_t acpi_device_adr_show(struct device *dev,
 511                                     struct device_attribute *attr, char *buf)
 512 {
 513         struct acpi_device *acpi_dev = to_acpi_device(dev);
 514
 515         return sprintf(buf, "0x%08x\n",
 516                        (unsigned int)(acpi_dev->pnp.bus_address));
 517 }
 518 static DEVICE_ATTR(adr, 0444, acpi_device_adr_show, NULL);
 519
 520 static ssize_t
 521 acpi_device_path_show(struct device *dev, struct device_attribute *attr, char *buf) {
 522         struct acpi_device *acpi_dev = to_acpi_device(dev);
 523         struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
 524         int result;
 525
 526         result = acpi_get_name(acpi_dev->handle, ACPI_FULL_PATHNAME, &path);
 527         if (result)
 528                 goto end;
 529
 530         result = sprintf(buf, "%s\n", (char*)path.pointer);
 531         kfree(path.pointer);
 532 end:
 533         return result;
 534 }
 535 static DEVICE_ATTR(path, 0444, acpi_device_path_show, NULL);
 536
 537 /* sysfs file that shows description text from the ACPI _STR method */
 538 static ssize_t description_show(struct device *dev,
 539                                 struct device_attribute *attr,
 540                                 char *buf) {
 541         struct acpi_device *acpi_dev = to_acpi_device(dev);
 542         int result;
 543
 544         if (acpi_dev->pnp.str_obj == NULL)
 545                 return 0;
 546
 547         /*
 548          * The _STR object contains a Unicode identifier for a device.
 549          * We need to convert to utf-8 so it can be displayed.
 550          */
 551         result = utf16s_to_utf8s(
 552                 (wchar_t *)acpi_dev->pnp.str_obj->buffer.pointer,
 553                 acpi_dev->pnp.str_obj->buffer.length,
 554                 UTF16_LITTLE_ENDIAN, buf,
 555                 PAGE_SIZE);
 556
 557         buf[result++] = '\n';
 558
 559         return result;
 560 }
 561 static DEVICE_ATTR(description, 0444, description_show, NULL);
 562
 563 static ssize_t
 564 acpi_device_sun_show(struct device *dev, struct device_attribute *attr,
 565                      char *buf) {
 566         struct acpi_device *acpi_dev = to_acpi_device(dev);
 567
 568         return sprintf(buf, "%lu\n", acpi_dev->pnp.sun);
 569 }
 570 static DEVICE_ATTR(sun, 0444, acpi_device_sun_show, NULL);
 571
 572 static int acpi_device_setup_files(struct acpi_device *dev)
 573 {
 574         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
 575         acpi_status status;
 576         unsigned long long sun;
 577         int result = 0;
 578
 579         /*
 580          * Devices gotten from FADT don't have a "path" attribute
 581          */
 582         if (dev->handle) {
 583                 result = device_create_file(&dev->dev, &dev_attr_path);
 584                 if (result)
 585                         goto end;
 586         }
 587
 588         if (!list_empty(&dev->pnp.ids)) {
 589                 result = device_create_file(&dev->dev, &dev_attr_hid);
 590                 if (result)
 591                         goto end;
 592
 593                 result = device_create_file(&dev->dev, &dev_attr_modalias);
 594                 if (result)
 595                         goto end;
 596         }
 597
 598         /*
 599          * If device has _STR, 'description' file is created
 600          */
 601         if (acpi_has_method(dev->handle, "_STR")) {
 602                 status = acpi_evaluate_object(dev->handle, "_STR",
 603                                         NULL, &buffer);
 604                 if (ACPI_FAILURE(status))
 605                         buffer.pointer = NULL;
 606                 dev->pnp.str_obj = buffer.pointer;
 607                 result = device_create_file(&dev->dev, &dev_attr_description);
 608                 if (result)
 609                         goto end;
 610         }
 611
 612         if (dev->pnp.type.bus_address)
 613                 result = device_create_file(&dev->dev, &dev_attr_adr);
 614         if (dev->pnp.unique_id)
 615                 result = device_create_file(&dev->dev, &dev_attr_uid);
 616
 617         status = acpi_evaluate_integer(dev->handle, "_SUN", NULL, &sun);
 618         if (ACPI_SUCCESS(status)) {
 619                 dev->pnp.sun = (unsigned long)sun;
 620                 result = device_create_file(&dev->dev, &dev_attr_sun);
 621                 if (result)
 622                         goto end;
 623         } else {
 624                 dev->pnp.sun = (unsigned long)-1;
 625         }
 626
 627         /*
 628          * If device has _EJ0, 'eject' file is created that is used to trigger
 629          * hot-removal function from userland.
 630          */
 631         if (acpi_has_method(dev->handle, "_EJ0")) {
 632                 result = device_create_file(&dev->dev, &dev_attr_eject);
 633                 if (result)
 634                         return result;
 635         }
 636
 637         if (dev->flags.power_manageable) {
 638                 result = device_create_file(&dev->dev, &dev_attr_power_state);
 639                 if (result)
 640                         return result;
 641
 642                 if (dev->power.flags.power_resources)
 643                         result = device_create_file(&dev->dev,
 644                                                     &dev_attr_real_power_state);
 645         }
 646
 647 end:
 648         return result;
 649 }
 650
 651 static void acpi_device_remove_files(struct acpi_device *dev)
 652 {
 653         if (dev->flags.power_manageable) {
 654                 device_remove_file(&dev->dev, &dev_attr_power_state);
 655                 if (dev->power.flags.power_resources)
 656                         device_remove_file(&dev->dev,
 657                                            &dev_attr_real_power_state);
 658         }
 659
 660         /*
 661          * If device has _STR, remove 'description' file
 662          */
 663         if (acpi_has_method(dev->handle, "_STR")) {
 664                 kfree(dev->pnp.str_obj);
 665                 device_remove_file(&dev->dev, &dev_attr_description);
 666         }
 667         /*
 668          * If device has _EJ0, remove 'eject' file.
 669          */
 670         if (acpi_has_method(dev->handle, "_EJ0"))
 671                 device_remove_file(&dev->dev, &dev_attr_eject);
 672
 673         if (acpi_has_method(dev->handle, "_SUN"))
 674                 device_remove_file(&dev->dev, &dev_attr_sun);
 675
 676         if (dev->pnp.unique_id)
 677                 device_remove_file(&dev->dev, &dev_attr_uid);
 678         if (dev->pnp.type.bus_address)
 679                 device_remove_file(&dev->dev, &dev_attr_adr);
 680         device_remove_file(&dev->dev, &dev_attr_modalias);
 681         device_remove_file(&dev->dev, &dev_attr_hid);
 682         if (dev->handle)
 683                 device_remove_file(&dev->dev, &dev_attr_path);
 684 }
 685 /* --------------------------------------------------------------------------
 686                         ACPI Bus operations
 687    -------------------------------------------------------------------------- */
 688
 689 static const struct acpi_device_id *__acpi_match_device(
 690         struct acpi_device *device, const struct acpi_device_id *ids)
 691 {
 692         const struct acpi_device_id *id;
 693         struct acpi_hardware_id *hwid;
 694
 695         /*
 696          * If the device is not present, it is unnecessary to load device
 697          * driver for it.
 698          */
 699         if (!device->status.present)
 700                 return NULL;
 701
 702         for (id = ids; id->id[0]; id++)
 703                 list_for_each_entry(hwid, &device->pnp.ids, list)
 704                         if (!strcmp((char *) id->id, hwid->id))
 705                                 return id;
 706
 707         return NULL;
 708 }
 709
 710 /**
 711  * acpi_match_device - Match a struct device against a given list of ACPI IDs
 712  * @ids: Array of struct acpi_device_id object to match against.
 713  * @dev: The device structure to match.
 714  *
 715  * Check if @dev has a valid ACPI handle and if there is a struct acpi_device
 716  * object for that handle and use that object to match against a given list of
 717  * device IDs.
 718  *
 719  * Return a pointer to the first matching ID on success or %NULL on failure.
 720  */
 721 const struct acpi_device_id *acpi_match_device(const struct acpi_device_id *ids,
 722                                                const struct device *dev)
 723 {
 724         struct acpi_device *adev;
 725         acpi_handle handle = ACPI_HANDLE(dev);
 726
 727         if (!ids || !handle || acpi_bus_get_device(handle, &adev))
 728                 return NULL;
 729
 730         return __acpi_match_device(adev, ids);
 731 }
 732 EXPORT_SYMBOL_GPL(acpi_match_device);
 733
 734 int acpi_match_device_ids(struct acpi_device *device,
 735                           const struct acpi_device_id *ids)
 736 {
 737         return __acpi_match_device(device, ids) ? 0 : -ENOENT;
 738 }
 739 EXPORT_SYMBOL(acpi_match_device_ids);
 740
 741 static void acpi_free_power_resources_lists(struct acpi_device *device)
 742 {
 743         int i;
 744
 745         if (device->wakeup.flags.valid)
 746                 acpi_power_resources_list_free(&device->wakeup.resources);
 747
 748         if (!device->flags.power_manageable)
 749                 return;
 750
 751         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
 752                 struct acpi_device_power_state *ps = &device->power.states[i];
 753                 acpi_power_resources_list_free(&ps->resources);
 754         }
 755 }
 756
 757 static void acpi_device_release(struct device *dev)
 758 {
 759         struct acpi_device *acpi_dev = to_acpi_device(dev);
 760
 761         acpi_free_pnp_ids(&acpi_dev->pnp);
 762         acpi_free_power_resources_lists(acpi_dev);
 763         kfree(acpi_dev);
 764 }
 765
 766 static int acpi_bus_match(struct device *dev, struct device_driver *drv)
 767 {
 768         struct acpi_device *acpi_dev = to_acpi_device(dev);
 769         struct acpi_driver *acpi_drv = to_acpi_driver(drv);
 770
 771         return acpi_dev->flags.match_driver
 772                 && !acpi_match_device_ids(acpi_dev, acpi_drv->ids);
 773 }
 774
 775 static int acpi_device_uevent(struct device *dev, struct kobj_uevent_env *env)
 776 {
 777         struct acpi_device *acpi_dev = to_acpi_device(dev);
 778         int len;
 779
 780         if (list_empty(&acpi_dev->pnp.ids))
 781                 return 0;
 782
 783         if (add_uevent_var(env, "MODALIAS="))
 784                 return -ENOMEM;
 785         len = create_modalias(acpi_dev, &env->buf[env->buflen - 1],
 786                               sizeof(env->buf) - env->buflen);
 787         if (len >= (sizeof(env->buf) - env->buflen))
 788                 return -ENOMEM;
 789         env->buflen += len;
 790         return 0;
 791 }
 792
 793 static void acpi_device_notify(acpi_handle handle, u32 event, void *data)
 794 {
 795         struct acpi_device *device = data;
 796
 797         device->driver->ops.notify(device, event);
 798 }
 799
 800 static acpi_status acpi_device_notify_fixed(void *data)
 801 {
 802         struct acpi_device *device = data;
 803
 804         /* Fixed hardware devices have no handles */
 805         acpi_device_notify(NULL, ACPI_FIXED_HARDWARE_EVENT, device);
 806         return AE_OK;
 807 }
 808
 809 static int acpi_device_install_notify_handler(struct acpi_device *device)
 810 {
 811         acpi_status status;
 812
 813         if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
 814                 status =
 815                     acpi_install_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
 816                                                      acpi_device_notify_fixed,
 817                                                      device);
 818         else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
 819                 status =
 820                     acpi_install_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
 821                                                      acpi_device_notify_fixed,
 822                                                      device);
 823         else
 824                 status = acpi_install_notify_handler(device->handle,
 825                                                      ACPI_DEVICE_NOTIFY,
 826                                                      acpi_device_notify,
 827                                                      device);
 828
 829         if (ACPI_FAILURE(status))
 830                 return -EINVAL;
 831         return 0;
 832 }
 833
 834 static void acpi_device_remove_notify_handler(struct acpi_device *device)
 835 {
 836         if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
 837                 acpi_remove_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
 838                                                 acpi_device_notify_fixed);
 839         else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
 840                 acpi_remove_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
 841                                                 acpi_device_notify_fixed);
 842         else
 843                 acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
 844                                            acpi_device_notify);
 845 }
 846
 847 static int acpi_device_probe(struct device *dev)
 848 {
 849         struct acpi_device *acpi_dev = to_acpi_device(dev);
 850         struct acpi_driver *acpi_drv = to_acpi_driver(dev->driver);
 851         int ret;
 852
 853         if (acpi_dev->handler)
 854                 return -EINVAL;
 855
 856         if (!acpi_drv->ops.add)
 857                 return -ENOSYS;
 858
 859         ret = acpi_drv->ops.add(acpi_dev);
 860         if (ret)
 861                 return ret;
 862
 863         acpi_dev->driver = acpi_drv;
 864         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 865                           "Driver [%s] successfully bound to device [%s]\n",
 866                           acpi_drv->name, acpi_dev->pnp.bus_id));
 867
 868         if (acpi_drv->ops.notify) {
 869                 ret = acpi_device_install_notify_handler(acpi_dev);
 870                 if (ret) {
 871                         if (acpi_drv->ops.remove)
 872                                 acpi_drv->ops.remove(acpi_dev);
 873
 874                         acpi_dev->driver = NULL;
 875                         acpi_dev->driver_data = NULL;
 876                         return ret;
 877                 }
 878         }
 879
 880         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found driver [%s] for device [%s]\n",
 881                           acpi_drv->name, acpi_dev->pnp.bus_id));
 882         get_device(dev);
 883         return 0;
 884 }
 885
 886 static int acpi_device_remove(struct device * dev)
 887 {
 888         struct acpi_device *acpi_dev = to_acpi_device(dev);
 889         struct acpi_driver *acpi_drv = acpi_dev->driver;
 890
 891         if (acpi_drv) {
 892                 if (acpi_drv->ops.notify)
 893                         acpi_device_remove_notify_handler(acpi_dev);
 894                 if (acpi_drv->ops.remove)
 895                         acpi_drv->ops.remove(acpi_dev);
 896         }
 897         acpi_dev->driver = NULL;
 898         acpi_dev->driver_data = NULL;
 899
 900         put_device(dev);
 901         return 0;
 902 }
 903
 904 struct bus_type acpi_bus_type = {
 905         .name           = "acpi",
 906         .match          = acpi_bus_match,
 907         .probe          = acpi_device_probe,
 908         .remove         = acpi_device_remove,
 909         .uevent         = acpi_device_uevent,
 910 };
 911
 912 static void acpi_device_del(struct acpi_device *device)
 913 {
 914         mutex_lock(&acpi_device_lock);
 915         if (device->parent)
 916                 list_del(&device->node);
 917
 918         list_del(&device->wakeup_list);
 919         mutex_unlock(&acpi_device_lock);
 920
 921         acpi_power_add_remove_device(device, false);
 922         acpi_device_remove_files(device);
 923         if (device->remove)
 924                 device->remove(device);
 925
 926         device_del(&device->dev);
 927 }
 928
 929 static LIST_HEAD(acpi_device_del_list);
 930 static DEFINE_MUTEX(acpi_device_del_lock);
 931
 932 static void acpi_device_del_work_fn(struct work_struct *work_not_used)
 933 {
 934         for (;;) {
 935                 struct acpi_device *adev;
 936
 937                 mutex_lock(&acpi_device_del_lock);
 938
 939                 if (list_empty(&acpi_device_del_list)) {
 940                         mutex_unlock(&acpi_device_del_lock);
 941                         break;
 942                 }
 943                 adev = list_first_entry(&acpi_device_del_list,
 944                                         struct acpi_device, del_list);
 945                 list_del(&adev->del_list);
 946
 947                 mutex_unlock(&acpi_device_del_lock);
 948
 949                 acpi_device_del(adev);
 950                 /*
 951                  * Drop references to all power resources that might have been
 952                  * used by the device.
 953                  */
 954                 acpi_power_transition(adev, ACPI_STATE_D3_COLD);
 955                 put_device(&adev->dev);
 956         }
 957 }
 958
 959 /**
 960  * acpi_scan_drop_device - Drop an ACPI device object.
 961  * @handle: Handle of an ACPI namespace node, not used.
 962  * @context: Address of the ACPI device object to drop.
 963  *
 964  * This is invoked by acpi_ns_delete_node() during the removal of the ACPI
 965  * namespace node the device object pointed to by @context is attached to.
 966  *
 967  * The unregistration is carried out asynchronously to avoid running
 968  * acpi_device_del() under the ACPICA's namespace mutex and the list is used to
 969  * ensure the correct ordering (the device objects must be unregistered in the
 970  * same order in which the corresponding namespace nodes are deleted).
 971  */
 972 static void acpi_scan_drop_device(acpi_handle handle, void *context)
 973 {
 974         static DECLARE_WORK(work, acpi_device_del_work_fn);
 975         struct acpi_device *adev = context;
 976
 977         mutex_lock(&acpi_device_del_lock);
 978
 979         /*
 980          * Use the ACPI hotplug workqueue which is ordered, so this work item
 981          * won't run after any hotplug work items submitted subsequently.  That
 982          * prevents attempts to register device objects identical to those being
 983          * deleted from happening concurrently (such attempts result from
 984          * hotplug events handled via the ACPI hotplug workqueue).  It also will
 985          * run after all of the work items submitted previosuly, which helps
 986          * those work items to ensure that they are not accessing stale device
 987          * objects.
 988          */
 989         if (list_empty(&acpi_device_del_list))
 990                 acpi_queue_hotplug_work(&work);
 991
 992         list_add_tail(&adev->del_list, &acpi_device_del_list);
 993         /* Make acpi_ns_validate_handle() return NULL for this handle. */
 994         adev->handle = INVALID_ACPI_HANDLE;
 995
 996         mutex_unlock(&acpi_device_del_lock);
 997 }
 998
 999 int acpi_bus_get_device(acpi_handle handle, struct acpi_device **device)
1000 {
1001         acpi_status status;
1002
1003         if (!device)
1004                 return -EINVAL;
1005
1006         status = acpi_get_data(handle, acpi_scan_drop_device, (void **)device);
1007         if (ACPI_FAILURE(status) || !*device) {
1008                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No context for object [%p]\n",
1009                                   handle));
1010                 return -ENODEV;
1011         }
1012         return 0;
1013 }
1014 EXPORT_SYMBOL(acpi_bus_get_device);
1015
1016 int acpi_device_add(struct acpi_device *device,
1017                     void (*release)(struct device *))
1018 {
1019         int result;
1020         struct acpi_device_bus_id *acpi_device_bus_id, *new_bus_id;
1021         int found = 0;
1022
1023         if (device->handle) {
1024                 acpi_status status;
1025
1026                 status = acpi_attach_data(device->handle, acpi_scan_drop_device,
1027                                           device);
1028                 if (ACPI_FAILURE(status)) {
1029                         acpi_handle_err(device->handle,
1030                                         "Unable to attach device data\n");
1031                         return -ENODEV;
1032                 }
1033         }
1034
1035         /*
1036          * Linkage
1037          * -------
1038          * Link this device to its parent and siblings.
1039          */
1040         INIT_LIST_HEAD(&device->children);
1041         INIT_LIST_HEAD(&device->node);
1042         INIT_LIST_HEAD(&device->wakeup_list);
1043         INIT_LIST_HEAD(&device->physical_node_list);
1044         INIT_LIST_HEAD(&device->del_list);
1045         mutex_init(&device->physical_node_lock);
1046
1047         new_bus_id = kzalloc(sizeof(struct acpi_device_bus_id), GFP_KERNEL);
1048         if (!new_bus_id) {
1049                 pr_err(PREFIX "Memory allocation error\n");
1050                 result = -ENOMEM;
1051                 goto err_detach;
1052         }
1053
1054         mutex_lock(&acpi_device_lock);
1055         /*
1056          * Find suitable bus_id and instance number in acpi_bus_id_list
1057          * If failed, create one and link it into acpi_bus_id_list
1058          */
1059         list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
1060                 if (!strcmp(acpi_device_bus_id->bus_id,
1061                             acpi_device_hid(device))) {
1062                         acpi_device_bus_id->instance_no++;
1063                         found = 1;
1064                         kfree(new_bus_id);
1065                         break;
1066                 }
1067         }
1068         if (!found) {
1069                 acpi_device_bus_id = new_bus_id;
1070                 strcpy(acpi_device_bus_id->bus_id, acpi_device_hid(device));
1071                 acpi_device_bus_id->instance_no = 0;
1072                 list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
1073         }
1074         dev_set_name(&device->dev, "%s:%02x", acpi_device_bus_id->bus_id, acpi_device_bus_id->instance_no);
1075
1076         if (device->parent)
1077                 list_add_tail(&device->node, &device->parent->children);
1078
1079         if (device->wakeup.flags.valid)
1080                 list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);
1081         mutex_unlock(&acpi_device_lock);
1082
1083         if (device->parent)
1084                 device->dev.parent = &device->parent->dev;
1085         device->dev.bus = &acpi_bus_type;
1086         device->dev.release = release;
1087         result = device_add(&device->dev);
1088         if (result) {
1089                 dev_err(&device->dev, "Error registering device\n");
1090                 goto err;
1091         }
1092
1093         result = acpi_device_setup_files(device);
1094         if (result)
1095                 printk(KERN_ERR PREFIX "Error creating sysfs interface for device %s\n",
1096                        dev_name(&device->dev));
1097
1098         return 0;
1099
1100  err:
1101         mutex_lock(&acpi_device_lock);
1102         if (device->parent)
1103                 list_del(&device->node);
1104         list_del(&device->wakeup_list);
1105         mutex_unlock(&acpi_device_lock);
1106
1107  err_detach:
1108         acpi_detach_data(device->handle, acpi_scan_drop_device);
1109         return result;
1110 }
1111
1112 /* --------------------------------------------------------------------------
1113                                  Driver Management
1114    -------------------------------------------------------------------------- */
1115 /**
1116  * acpi_bus_register_driver - register a driver with the ACPI bus
1117  * @driver: driver being registered
1118  *
1119  * Registers a driver with the ACPI bus.  Searches the namespace for all
1120  * devices that match the driver's criteria and binds.  Returns zero for
1121  * success or a negative error status for failure.
1122  */
1123 int acpi_bus_register_driver(struct acpi_driver *driver)
1124 {
1125         int ret;
1126
1127         if (acpi_disabled)
1128                 return -ENODEV;
1129         driver->drv.name = driver->name;
1130         driver->drv.bus = &acpi_bus_type;
1131         driver->drv.owner = driver->owner;
1132
1133         ret = driver_register(&driver->drv);
1134         return ret;
1135 }
1136
1137 EXPORT_SYMBOL(acpi_bus_register_driver);
1138
1139 /**
1140  * acpi_bus_unregister_driver - unregisters a driver with the ACPI bus
1141  * @driver: driver to unregister
1142  *
1143  * Unregisters a driver with the ACPI bus.  Searches the namespace for all
1144  * devices that match the driver's criteria and unbinds.
1145  */
1146 void acpi_bus_unregister_driver(struct acpi_driver *driver)
1147 {
1148         driver_unregister(&driver->drv);
1149 }
1150
1151 EXPORT_SYMBOL(acpi_bus_unregister_driver);
1152
1153 /* --------------------------------------------------------------------------
1154                                  Device Enumeration
1155    -------------------------------------------------------------------------- */
1156 static struct acpi_device *acpi_bus_get_parent(acpi_handle handle)
1157 {
1158         struct acpi_device *device = NULL;
1159         acpi_status status;
1160
1161         /*
1162          * Fixed hardware devices do not appear in the namespace and do not
1163          * have handles, but we fabricate acpi_devices for them, so we have
1164          * to deal with them specially.
1165          */
1166         if (!handle)
1167                 return acpi_root;
1168
1169         do {
1170                 status = acpi_get_parent(handle, &handle);
1171                 if (ACPI_FAILURE(status))
1172                         return status == AE_NULL_ENTRY ? NULL : acpi_root;
1173         } while (acpi_bus_get_device(handle, &device));
1174         return device;
1175 }
1176
1177 acpi_status
1178 acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
1179 {
1180         acpi_status status;
1181         acpi_handle tmp;
1182         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
1183         union acpi_object *obj;
1184
1185         status = acpi_get_handle(handle, "_EJD", &tmp);
1186         if (ACPI_FAILURE(status))
1187                 return status;
1188
1189         status = acpi_evaluate_object(handle, "_EJD", NULL, &buffer);
1190         if (ACPI_SUCCESS(status)) {
1191                 obj = buffer.pointer;
1192                 status = acpi_get_handle(ACPI_ROOT_OBJECT, obj->string.pointer,
1193                                          ejd);
1194                 kfree(buffer.pointer);
1195         }
1196         return status;
1197 }
1198 EXPORT_SYMBOL_GPL(acpi_bus_get_ejd);
1199
1200 static int acpi_bus_extract_wakeup_device_power_package(acpi_handle handle,
1201                                         struct acpi_device_wakeup *wakeup)
1202 {
1203         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1204         union acpi_object *package = NULL;
1205         union acpi_object *element = NULL;
1206         acpi_status status;
1207         int err = -ENODATA;
1208
1209         if (!wakeup)
1210                 return -EINVAL;
1211
1212         INIT_LIST_HEAD(&wakeup->resources);
1213
1214         /* _PRW */
1215         status = acpi_evaluate_object(handle, "_PRW", NULL, &buffer);
1216         if (ACPI_FAILURE(status)) {
1217                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRW"));
1218                 return err;
1219         }
1220
1221         package = (union acpi_object *)buffer.pointer;
1222
1223         if (!package || package->package.count < 2)
1224                 goto out;
1225
1226         element = &(package->package.elements[0]);
1227         if (!element)
1228                 goto out;
1229
1230         if (element->type == ACPI_TYPE_PACKAGE) {
1231                 if ((element->package.count < 2) ||
1232                     (element->package.elements[0].type !=
1233                      ACPI_TYPE_LOCAL_REFERENCE)
1234                     || (element->package.elements[1].type != ACPI_TYPE_INTEGER))
1235                         goto out;
1236
1237                 wakeup->gpe_device =
1238                     element->package.elements[0].reference.handle;
1239                 wakeup->gpe_number =
1240                     (u32) element->package.elements[1].integer.value;
1241         } else if (element->type == ACPI_TYPE_INTEGER) {
1242                 wakeup->gpe_device = NULL;
1243                 wakeup->gpe_number = element->integer.value;
1244         } else {
1245                 goto out;
1246         }
1247
1248         element = &(package->package.elements[1]);
1249         if (element->type != ACPI_TYPE_INTEGER)
1250                 goto out;
1251
1252         wakeup->sleep_state = element->integer.value;
1253
1254         err = acpi_extract_power_resources(package, 2, &wakeup->resources);
1255         if (err)
1256                 goto out;
1257
1258         if (!list_empty(&wakeup->resources)) {
1259                 int sleep_state;
1260
1261                 err = acpi_power_wakeup_list_init(&wakeup->resources,
1262                                                   &sleep_state);
1263                 if (err) {
1264                         acpi_handle_warn(handle, "Retrieving current states "
1265                                          "of wakeup power resources failed\n");
1266                         acpi_power_resources_list_free(&wakeup->resources);
1267                         goto out;
1268                 }
1269                 if (sleep_state < wakeup->sleep_state) {
1270                         acpi_handle_warn(handle, "Overriding _PRW sleep state "
1271                                          "(S%d) by S%d from power resources\n",
1272                                          (int)wakeup->sleep_state, sleep_state);
1273                         wakeup->sleep_state = sleep_state;
1274                 }
1275         }
1276         acpi_setup_gpe_for_wake(handle, wakeup->gpe_device, wakeup->gpe_number);
1277
1278  out:
1279         kfree(buffer.pointer);
1280         return err;
1281 }
1282
1283 static void acpi_bus_set_run_wake_flags(struct acpi_device *device)
1284 {
1285         struct acpi_device_id button_device_ids[] = {
1286                 {"PNP0C0C", 0},
1287                 {"PNP0C0D", 0},
1288                 {"PNP0C0E", 0},
1289                 {"", 0},
1290         };
1291         acpi_status status;
1292         acpi_event_status event_status;
1293
1294         device->wakeup.flags.notifier_present = 0;
1295
1296         /* Power button, Lid switch always enable wakeup */
1297         if (!acpi_match_device_ids(device, button_device_ids)) {
1298                 device->wakeup.flags.run_wake = 1;
1299                 if (!acpi_match_device_ids(device, &button_device_ids[1])) {
1300                         /* Do not use Lid/sleep button for S5 wakeup */
1301                         if (device->wakeup.sleep_state == ACPI_STATE_S5)
1302                                 device->wakeup.sleep_state = ACPI_STATE_S4;
1303                 }
1304                 device_set_wakeup_capable(&device->dev, true);
1305                 return;
1306         }
1307
1308         status = acpi_get_gpe_status(device->wakeup.gpe_device,
1309                                         device->wakeup.gpe_number,
1310                                                 &event_status);
1311         if (status == AE_OK)
1312                 device->wakeup.flags.run_wake =
1313                                 !!(event_status & ACPI_EVENT_FLAG_HANDLE);
1314 }
1315
1316 static void acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
1317 {
1318         int err;
1319
1320         /* Presence of _PRW indicates wake capable */
1321         if (!acpi_has_method(device->handle, "_PRW"))
1322                 return;
1323
1324         err = acpi_bus_extract_wakeup_device_power_package(device->handle,
1325                                                            &device->wakeup);
1326         if (err) {
1327                 dev_err(&device->dev, "_PRW evaluation error: %d\n", err);
1328                 return;
1329         }
1330
1331         device->wakeup.flags.valid = 1;
1332         device->wakeup.prepare_count = 0;
1333         acpi_bus_set_run_wake_flags(device);
1334         /* Call _PSW/_DSW object to disable its ability to wake the sleeping
1335          * system for the ACPI device with the _PRW object.
1336          * The _PSW object is depreciated in ACPI 3.0 and is replaced by _DSW.
1337          * So it is necessary to call _DSW object first. Only when it is not
1338          * present will the _PSW object used.
1339          */
1340         err = acpi_device_sleep_wake(device, 0, 0, 0);
1341         if (err)
1342                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1343                                 "error in _DSW or _PSW evaluation\n"));
1344 }
1345
1346 static void acpi_bus_init_power_state(struct acpi_device *device, int state)
1347 {
1348         struct acpi_device_power_state *ps = &device->power.states[state];
1349         char pathname[5] = { '_', 'P', 'R', '0' + state, '\0' };
1350         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1351         acpi_status status;
1352
1353         INIT_LIST_HEAD(&ps->resources);
1354
1355         /* Evaluate "_PRx" to get referenced power resources */
1356         status = acpi_evaluate_object(device->handle, pathname, NULL, &buffer);
1357         if (ACPI_SUCCESS(status)) {
1358                 union acpi_object *package = buffer.pointer;
1359
1360                 if (buffer.length && package
1361                     && package->type == ACPI_TYPE_PACKAGE
1362                     && package->package.count) {
1363                         int err = acpi_extract_power_resources(package, 0,
1364                                                                &ps->resources);
1365                         if (!err)
1366                                 device->power.flags.power_resources = 1;
1367                 }
1368                 ACPI_FREE(buffer.pointer);
1369         }
1370
1371         /* Evaluate "_PSx" to see if we can do explicit sets */
1372         pathname[2] = 'S';
1373         if (acpi_has_method(device->handle, pathname))
1374                 ps->flags.explicit_set = 1;
1375
1376         /*
1377          * State is valid if there are means to put the device into it.
1378          * D3hot is only valid if _PR3 present.
1379          */
1380         if (!list_empty(&ps->resources)
1381             || (ps->flags.explicit_set && state < ACPI_STATE_D3_HOT)) {
1382                 ps->flags.valid = 1;
1383                 ps->flags.os_accessible = 1;
1384         }
1385
1386         ps->power = -1;         /* Unknown - driver assigned */
1387         ps->latency = -1;       /* Unknown - driver assigned */
1388 }
1389
1390 static void acpi_bus_get_power_flags(struct acpi_device *device)
1391 {
1392         u32 i;
1393
1394         /* Presence of _PS0|_PR0 indicates 'power manageable' */
1395         if (!acpi_has_method(device->handle, "_PS0") &&
1396             !acpi_has_method(device->handle, "_PR0"))
1397                 return;
1398
1399         device->flags.power_manageable = 1;
1400
1401         /*
1402          * Power Management Flags
1403          */
1404         if (acpi_has_method(device->handle, "_PSC"))
1405                 device->power.flags.explicit_get = 1;
1406         if (acpi_has_method(device->handle, "_IRC"))
1407                 device->power.flags.inrush_current = 1;
1408
1409         /*
1410          * Enumerate supported power management states
1411          */
1412         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++)
1413                 acpi_bus_init_power_state(device, i);
1414
1415         INIT_LIST_HEAD(&device->power.states[ACPI_STATE_D3_COLD].resources);
1416
1417         /* Set defaults for D0 and D3 states (always valid) */
1418         device->power.states[ACPI_STATE_D0].flags.valid = 1;
1419         device->power.states[ACPI_STATE_D0].power = 100;
1420         device->power.states[ACPI_STATE_D3_COLD].flags.valid = 1;
1421         device->power.states[ACPI_STATE_D3_COLD].power = 0;
1422
1423         /* Set D3cold's explicit_set flag if _PS3 exists. */
1424         if (device->power.states[ACPI_STATE_D3_HOT].flags.explicit_set)
1425                 device->power.states[ACPI_STATE_D3_COLD].flags.explicit_set = 1;
1426
1427         /* Presence of _PS3 or _PRx means we can put the device into D3 cold */
1428         if (device->power.states[ACPI_STATE_D3_HOT].flags.explicit_set ||
1429                         device->power.flags.power_resources)
1430                 device->power.states[ACPI_STATE_D3_COLD].flags.os_accessible = 1;
1431
1432         if (acpi_bus_init_power(device)) {
1433                 acpi_free_power_resources_lists(device);
1434                 device->flags.power_manageable = 0;
1435         }
1436 }
1437
1438 static void acpi_bus_get_flags(struct acpi_device *device)
1439 {
1440         /* Presence of _STA indicates 'dynamic_status' */
1441         if (acpi_has_method(device->handle, "_STA"))
1442                 device->flags.dynamic_status = 1;
1443
1444         /* Presence of _RMV indicates 'removable' */
1445         if (acpi_has_method(device->handle, "_RMV"))
1446                 device->flags.removable = 1;
1447
1448         /* Presence of _EJD|_EJ0 indicates 'ejectable' */
1449         if (acpi_has_method(device->handle, "_EJD") ||
1450             acpi_has_method(device->handle, "_EJ0"))
1451                 device->flags.ejectable = 1;
1452 }
1453
1454 static void acpi_device_get_busid(struct acpi_device *device)
1455 {
1456         char bus_id[5] = { '?', 0 };
1457         struct acpi_buffer buffer = { sizeof(bus_id), bus_id };
1458         int i = 0;
1459
1460         /*
1461          * Bus ID
1462          * ------
1463          * The device's Bus ID is simply the object name.
1464          * TBD: Shouldn't this value be unique (within the ACPI namespace)?
1465          */
1466         if (ACPI_IS_ROOT_DEVICE(device)) {
1467                 strcpy(device->pnp.bus_id, "ACPI");
1468                 return;
1469         }
1470
1471         switch (device->device_type) {
1472         case ACPI_BUS_TYPE_POWER_BUTTON:
1473                 strcpy(device->pnp.bus_id, "PWRF");
1474                 break;
1475         case ACPI_BUS_TYPE_SLEEP_BUTTON:
1476                 strcpy(device->pnp.bus_id, "SLPF");
1477                 break;
1478         default:
1479                 acpi_get_name(device->handle, ACPI_SINGLE_NAME, &buffer);
1480                 /* Clean up trailing underscores (if any) */
1481                 for (i = 3; i > 1; i--) {
1482                         if (bus_id[i] == '_')
1483                                 bus_id[i] = '\0';
1484                         else
1485                                 break;
1486                 }
1487                 strcpy(device->pnp.bus_id, bus_id);
1488                 break;
1489         }
1490 }
1491
1492 /*
1493  * acpi_ata_match - see if an acpi object is an ATA device
1494  *
1495  * If an acpi object has one of the ACPI ATA methods defined,
1496  * then we can safely call it an ATA device.
1497  */
1498 bool acpi_ata_match(acpi_handle handle)
1499 {
1500         return acpi_has_method(handle, "_GTF") ||
1501                acpi_has_method(handle, "_GTM") ||
1502                acpi_has_method(handle, "_STM") ||
1503                acpi_has_method(handle, "_SDD");
1504 }
1505
1506 /*
1507  * acpi_bay_match - see if an acpi object is an ejectable driver bay
1508  *
1509  * If an acpi object is ejectable and has one of the ACPI ATA methods defined,
1510  * then we can safely call it an ejectable drive bay
1511  */
1512 bool acpi_bay_match(acpi_handle handle)
1513 {
1514         acpi_handle phandle;
1515
1516         if (!acpi_has_method(handle, "_EJ0"))
1517                 return false;
1518         if (acpi_ata_match(handle))
1519                 return true;
1520         if (ACPI_FAILURE(acpi_get_parent(handle, &phandle)))
1521                 return false;
1522
1523         return acpi_ata_match(phandle);
1524 }
1525
1526 /*
1527  * acpi_dock_match - see if an acpi object has a _DCK method
1528  */
1529 bool acpi_dock_match(acpi_handle handle)
1530 {
1531         return acpi_has_method(handle, "_DCK");
1532 }
1533
1534 const char *acpi_device_hid(struct acpi_device *device)
1535 {
1536         struct acpi_hardware_id *hid;
1537
1538         if (list_empty(&device->pnp.ids))
1539                 return dummy_hid;
1540
1541         hid = list_first_entry(&device->pnp.ids, struct acpi_hardware_id, list);
1542         return hid->id;
1543 }
1544 EXPORT_SYMBOL(acpi_device_hid);
1545
1546 static void acpi_add_id(struct acpi_device_pnp *pnp, const char *dev_id)
1547 {
1548         struct acpi_hardware_id *id;
1549
1550         id = kmalloc(sizeof(*id), GFP_KERNEL);
1551         if (!id)
1552                 return;
1553
1554         id->id = kstrdup(dev_id, GFP_KERNEL);
1555         if (!id->id) {
1556                 kfree(id);
1557                 return;
1558         }
1559
1560         list_add_tail(&id->list, &pnp->ids);
1561         pnp->type.hardware_id = 1;
1562 }
1563
1564 /*
1565  * Old IBM workstations have a DSDT bug wherein the SMBus object
1566  * lacks the SMBUS01 HID and the methods do not have the necessary "_"
1567  * prefix.  Work around this.
1568  */
1569 static bool acpi_ibm_smbus_match(acpi_handle handle)
1570 {
1571         char node_name[ACPI_PATH_SEGMENT_LENGTH];
1572         struct acpi_buffer path = { sizeof(node_name), node_name };
1573
1574         if (!dmi_name_in_vendors("IBM"))
1575                 return false;
1576
1577         /* Look for SMBS object */
1578         if (ACPI_FAILURE(acpi_get_name(handle, ACPI_SINGLE_NAME, &path)) ||
1579             strcmp("SMBS", path.pointer))
1580                 return false;
1581
1582         /* Does it have the necessary (but misnamed) methods? */
1583         if (acpi_has_method(handle, "SBI") &&
1584             acpi_has_method(handle, "SBR") &&
1585             acpi_has_method(handle, "SBW"))
1586                 return true;
1587
1588         return false;
1589 }
1590
1591 static void acpi_set_pnp_ids(acpi_handle handle, struct acpi_device_pnp *pnp,
1592                                 int device_type)
1593 {
1594         acpi_status status;
1595         struct acpi_device_info *info;
1596         struct acpi_pnp_device_id_list *cid_list;
1597         int i;
1598
1599         switch (device_type) {
1600         case ACPI_BUS_TYPE_DEVICE:
1601                 if (handle == ACPI_ROOT_OBJECT) {
1602                         acpi_add_id(pnp, ACPI_SYSTEM_HID);
1603                         break;
1604                 }
1605
1606                 status = acpi_get_object_info(handle, &info);
1607                 if (ACPI_FAILURE(status)) {
1608                         pr_err(PREFIX "%s: Error reading device info\n",
1609                                         __func__);
1610                         return;
1611                 }
1612
1613                 if (info->valid & ACPI_VALID_HID)
1614                         acpi_add_id(pnp, info->hardware_id.string);
1615                 if (info->valid & ACPI_VALID_CID) {
1616                         cid_list = &info->compatible_id_list;
1617                         for (i = 0; i < cid_list->count; i++)
1618                                 acpi_add_id(pnp, cid_list->ids[i].string);
1619                 }
1620                 if (info->valid & ACPI_VALID_ADR) {
1621                         pnp->bus_address = info->address;
1622                         pnp->type.bus_address = 1;
1623                 }
1624                 if (info->valid & ACPI_VALID_UID)
1625                         pnp->unique_id = kstrdup(info->unique_id.string,
1626                                                         GFP_KERNEL);
1627
1628                 kfree(info);
1629
1630                 /*
1631                  * Some devices don't reliably have _HIDs & _CIDs, so add
1632                  * synthetic HIDs to make sure drivers can find them.
1633                  */
1634                 if (acpi_is_video_device(handle))
1635                         acpi_add_id(pnp, ACPI_VIDEO_HID);
1636                 else if (acpi_bay_match(handle))
1637                         acpi_add_id(pnp, ACPI_BAY_HID);
1638                 else if (acpi_dock_match(handle))
1639                         acpi_add_id(pnp, ACPI_DOCK_HID);
1640                 else if (acpi_ibm_smbus_match(handle))
1641                         acpi_add_id(pnp, ACPI_SMBUS_IBM_HID);
1642                 else if (list_empty(&pnp->ids) && handle == ACPI_ROOT_OBJECT) {
1643                         acpi_add_id(pnp, ACPI_BUS_HID); /* \_SB, LNXSYBUS */
1644                         strcpy(pnp->device_name, ACPI_BUS_DEVICE_NAME);
1645                         strcpy(pnp->device_class, ACPI_BUS_CLASS);
1646                 }
1647
1648                 break;
1649         case ACPI_BUS_TYPE_POWER:
1650                 acpi_add_id(pnp, ACPI_POWER_HID);
1651                 break;
1652         case ACPI_BUS_TYPE_PROCESSOR:
1653                 acpi_add_id(pnp, ACPI_PROCESSOR_OBJECT_HID);
1654                 break;
1655         case ACPI_BUS_TYPE_THERMAL:
1656                 acpi_add_id(pnp, ACPI_THERMAL_HID);
1657                 break;
1658         case ACPI_BUS_TYPE_POWER_BUTTON:
1659                 acpi_add_id(pnp, ACPI_BUTTON_HID_POWERF);
1660                 break;
1661         case ACPI_BUS_TYPE_SLEEP_BUTTON:
1662                 acpi_add_id(pnp, ACPI_BUTTON_HID_SLEEPF);
1663                 break;
1664         }
1665 }
1666
1667 void acpi_free_pnp_ids(struct acpi_device_pnp *pnp)
1668 {
1669         struct acpi_hardware_id *id, *tmp;
1670
1671         list_for_each_entry_safe(id, tmp, &pnp->ids, list) {
1672                 kfree(id->id);
1673                 kfree(id);
1674         }
1675         kfree(pnp->unique_id);
1676 }
1677
1678 void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,
1679                              int type, unsigned long long sta)
1680 {
1681         INIT_LIST_HEAD(&device->pnp.ids);
1682         device->device_type = type;
1683         device->handle = handle;
1684         device->parent = acpi_bus_get_parent(handle);
1685         acpi_set_device_status(device, sta);
1686         acpi_device_get_busid(device);
1687         acpi_set_pnp_ids(handle, &device->pnp, type);
1688         acpi_bus_get_flags(device);
1689         device->flags.match_driver = false;
1690         device->flags.initialized = true;
1691         device->flags.visited = false;
1692         device_initialize(&device->dev);
1693         dev_set_uevent_suppress(&device->dev, true);
1694 }
1695
1696 void acpi_device_add_finalize(struct acpi_device *device)
1697 {
1698         dev_set_uevent_suppress(&device->dev, false);
1699         kobject_uevent(&device->dev.kobj, KOBJ_ADD);
1700 }
1701
1702 static int acpi_add_single_object(struct acpi_device **child,
1703                                   acpi_handle handle, int type,
1704                                   unsigned long long sta)
1705 {
1706         int result;
1707         struct acpi_device *device;
1708         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1709
1710         device = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
1711         if (!device) {
1712                 printk(KERN_ERR PREFIX "Memory allocation error\n");
1713                 return -ENOMEM;
1714         }
1715
1716         acpi_init_device_object(device, handle, type, sta);
1717         acpi_bus_get_power_flags(device);
1718         acpi_bus_get_wakeup_device_flags(device);
1719
1720         result = acpi_device_add(device, acpi_device_release);
1721         if (result) {
1722                 acpi_device_release(&device->dev);
1723                 return result;
1724         }
1725
1726         acpi_power_add_remove_device(device, true);
1727         acpi_device_add_finalize(device);
1728         acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
1729         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Added %s [%s] parent %s\n",
1730                 dev_name(&device->dev), (char *) buffer.pointer,
1731                 device->parent ? dev_name(&device->parent->dev) : "(null)"));
1732         kfree(buffer.pointer);
1733         *child = device;
1734         return 0;
1735 }
1736
1737 static int acpi_bus_type_and_status(acpi_handle handle, int *type,
1738                                     unsigned long long *sta)
1739 {
1740         acpi_status status;
1741         acpi_object_type acpi_type;
1742
1743         status = acpi_get_type(handle, &acpi_type);
1744         if (ACPI_FAILURE(status))
1745                 return -ENODEV;
1746
1747         switch (acpi_type) {
1748         case ACPI_TYPE_ANY:             /* for ACPI_ROOT_OBJECT */
1749         case ACPI_TYPE_DEVICE:
1750                 *type = ACPI_BUS_TYPE_DEVICE;
1751                 status = acpi_bus_get_status_handle(handle, sta);
1752                 if (ACPI_FAILURE(status))
1753                         return -ENODEV;
1754                 break;
1755         case ACPI_TYPE_PROCESSOR:
1756                 *type = ACPI_BUS_TYPE_PROCESSOR;
1757                 status = acpi_bus_get_status_handle(handle, sta);
1758                 if (ACPI_FAILURE(status))
1759                         return -ENODEV;
1760                 break;
1761         case ACPI_TYPE_THERMAL:
1762                 *type = ACPI_BUS_TYPE_THERMAL;
1763                 *sta = ACPI_STA_DEFAULT;
1764                 break;
1765         case ACPI_TYPE_POWER:
1766                 *type = ACPI_BUS_TYPE_POWER;
1767                 *sta = ACPI_STA_DEFAULT;
1768                 break;
1769         default:
1770                 return -ENODEV;
1771         }
1772
1773         return 0;
1774 }
1775
1776 bool acpi_device_is_present(struct acpi_device *adev)
1777 {
1778         if (adev->status.present || adev->status.functional)
1779                 return true;
1780
1781         adev->flags.initialized = false;
1782         return false;
1783 }
1784
1785 static bool acpi_scan_handler_matching(struct acpi_scan_handler *handler,
1786                                        char *idstr,
1787                                        const struct acpi_device_id **matchid)
1788 {
1789         const struct acpi_device_id *devid;
1790
1791         for (devid = handler->ids; devid->id[0]; devid++)
1792                 if (!strcmp((char *)devid->id, idstr)) {
1793                         if (matchid)
1794                                 *matchid = devid;
1795
1796                         return true;
1797                 }
1798
1799         return false;
1800 }
1801
1802 static struct acpi_scan_handler *acpi_scan_match_handler(char *idstr,
1803                                         const struct acpi_device_id **matchid)
1804 {
1805         struct acpi_scan_handler *handler;
1806
1807         list_for_each_entry(handler, &acpi_scan_handlers_list, list_node)
1808                 if (acpi_scan_handler_matching(handler, idstr, matchid))
1809                         return handler;
1810
1811         return NULL;
1812 }
1813
1814 void acpi_scan_hotplug_enabled(struct acpi_hotplug_profile *hotplug, bool val)
1815 {
1816         if (!!hotplug->enabled == !!val)
1817                 return;
1818
1819         mutex_lock(&acpi_scan_lock);
1820
1821         hotplug->enabled = val;
1822
1823         mutex_unlock(&acpi_scan_lock);
1824 }
1825
1826 static void acpi_scan_init_hotplug(acpi_handle handle, int type)
1827 {
1828         struct acpi_device_pnp pnp = {};
1829         struct acpi_hardware_id *hwid;
1830         struct acpi_scan_handler *handler;
1831
1832         INIT_LIST_HEAD(&pnp.ids);
1833         acpi_set_pnp_ids(handle, &pnp, type);
1834
1835         if (!pnp.type.hardware_id)
1836                 goto out;
1837
1838         /*
1839          * This relies on the fact that acpi_install_notify_handler() will not
1840          * install the same notify handler routine twice for the same handle.
1841          */
1842         list_for_each_entry(hwid, &pnp.ids, list) {
1843                 handler = acpi_scan_match_handler(hwid->id, NULL);
1844                 if (handler) {
1845                         acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
1846                                         acpi_hotplug_notify_cb, handler);
1847                         break;
1848                 }
1849         }
1850
1851 out:
1852         acpi_free_pnp_ids(&pnp);
1853 }
1854
1855 static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl_not_used,
1856                                       void *not_used, void **return_value)
1857 {
1858         struct acpi_device *device = NULL;
1859         int type;
1860         unsigned long long sta;
1861         int result;
1862
1863         acpi_bus_get_device(handle, &device);
1864         if (device)
1865                 goto out;
1866
1867         result = acpi_bus_type_and_status(handle, &type, &sta);
1868         if (result)
1869                 return AE_OK;
1870
1871         if (type == ACPI_BUS_TYPE_POWER) {
1872                 acpi_add_power_resource(handle);
1873                 return AE_OK;
1874         }
1875
1876         acpi_scan_init_hotplug(handle, type);
1877
1878         acpi_add_single_object(&device, handle, type, sta);
1879         if (!device)
1880                 return AE_CTRL_DEPTH;
1881
1882  out:
1883         if (!*return_value)
1884                 *return_value = device;
1885
1886         return AE_OK;
1887 }
1888
1889 static int acpi_scan_attach_handler(struct acpi_device *device)
1890 {
1891         struct acpi_hardware_id *hwid;
1892         int ret = 0;
1893
1894         list_for_each_entry(hwid, &device->pnp.ids, list) {
1895                 const struct acpi_device_id *devid;
1896                 struct acpi_scan_handler *handler;
1897
1898                 handler = acpi_scan_match_handler(hwid->id, &devid);
1899                 if (handler) {
1900                         ret = handler->attach(device, devid);
1901                         if (ret > 0) {
1902                                 device->handler = handler;
1903                                 break;
1904                         } else if (ret < 0) {
1905                                 break;
1906                         }
1907                 }
1908         }
1909         return ret;
1910 }
1911
1912 static void acpi_bus_attach(struct acpi_device *device)
1913 {
1914         struct acpi_device *child;
1915         int ret;
1916
1917         acpi_bus_get_status(device);
1918         /* Skip devices that are not present. */
1919         if (!acpi_device_is_present(device)) {
1920                 device->flags.visited = false;
1921                 return;
1922         }
1923         if (device->handler)
1924                 goto ok;
1925
1926         if (!device->flags.initialized) {
1927                 acpi_bus_update_power(device, NULL);
1928                 device->flags.initialized = true;
1929         }
1930         device->flags.visited = false;
1931         ret = acpi_scan_attach_handler(device);
1932         if (ret < 0)
1933                 return;
1934
1935         device->flags.match_driver = true;
1936         if (!ret) {
1937                 ret = device_attach(&device->dev);
1938                 if (ret < 0)
1939                         return;
1940         }
1941         device->flags.visited = true;
1942
1943  ok:
1944         list_for_each_entry(child, &device->children, node)
1945                 acpi_bus_attach(child);
1946 }
1947
1948 /**
1949  * acpi_bus_scan - Add ACPI device node objects in a given namespace scope.
1950  * @handle: Root of the namespace scope to scan.
1951  *
1952  * Scan a given ACPI tree (probably recently hot-plugged) and create and add
1953  * found devices.
1954  *
1955  * If no devices were found, -ENODEV is returned, but it does not mean that
1956  * there has been a real error.  There just have been no suitable ACPI objects
1957  * in the table trunk from which the kernel could create a device and add an
1958  * appropriate driver.
1959  *
1960  * Must be called under acpi_scan_lock.
1961  */
1962 int acpi_bus_scan(acpi_handle handle)
1963 {
1964         void *device = NULL;
1965
1966         if (ACPI_SUCCESS(acpi_bus_check_add(handle, 0, NULL, &device)))
1967                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
1968                                     acpi_bus_check_add, NULL, NULL, &device);
1969
1970         if (device) {
1971                 acpi_bus_attach(device);
1972                 return 0;
1973         }
1974         return -ENODEV;
1975 }
1976 EXPORT_SYMBOL(acpi_bus_scan);
1977
1978 /**
1979  * acpi_bus_trim - Detach scan handlers and drivers from ACPI device objects.
1980  * @adev: Root of the ACPI namespace scope to walk.
1981  *
1982  * Must be called under acpi_scan_lock.
1983  */
1984 void acpi_bus_trim(struct acpi_device *adev)
1985 {
1986         struct acpi_scan_handler *handler = adev->handler;
1987         struct acpi_device *child;
1988
1989         list_for_each_entry_reverse(child, &adev->children, node)
1990                 acpi_bus_trim(child);
1991
1992         if (handler) {
1993                 if (handler->detach)
1994                         handler->detach(adev);
1995
1996                 adev->handler = NULL;
1997         } else {
1998                 device_release_driver(&adev->dev);
1999         }
2000         /*
2001          * Most likely, the device is going away, so put it into D3cold before
2002          * that.
2003          */
2004         acpi_device_set_power(adev, ACPI_STATE_D3_COLD);
2005         adev->flags.initialized = false;
2006         adev->flags.visited = false;
2007 }
2008 EXPORT_SYMBOL_GPL(acpi_bus_trim);
2009
2010 static int acpi_bus_scan_fixed(void)
2011 {
2012         int result = 0;
2013
2014         /*
2015          * Enumerate all fixed-feature devices.
2016          */
2017         if (!(acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON)) {
2018                 struct acpi_device *device = NULL;
2019
2020                 result = acpi_add_single_object(&device, NULL,
2021                                                 ACPI_BUS_TYPE_POWER_BUTTON,
2022                                                 ACPI_STA_DEFAULT);
2023                 if (result)
2024                         return result;
2025
2026                 device->flags.match_driver = true;
2027                 result = device_attach(&device->dev);
2028                 if (result < 0)
2029                         return result;
2030
2031                 device_init_wakeup(&device->dev, true);
2032         }
2033
2034         if (!(acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON)) {
2035                 struct acpi_device *device = NULL;
2036
2037                 result = acpi_add_single_object(&device, NULL,
2038                                                 ACPI_BUS_TYPE_SLEEP_BUTTON,
2039                                                 ACPI_STA_DEFAULT);
2040                 if (result)
2041                         return result;
2042
2043                 device->flags.match_driver = true;
2044                 result = device_attach(&device->dev);
2045         }
2046
2047         return result < 0 ? result : 0;
2048 }
2049
2050 int __init acpi_scan_init(void)
2051 {
2052         int result;
2053
2054         result = bus_register(&acpi_bus_type);
2055         if (result) {
2056                 /* We don't want to quit even if we failed to add suspend/resume */
2057                 printk(KERN_ERR PREFIX "Could not register bus type\n");
2058         }
2059
2060         acpi_pci_root_init();
2061         acpi_pci_link_init();
2062         acpi_processor_init();
2063         acpi_platform_init();
2064         acpi_lpss_init();
2065         acpi_cmos_rtc_init();
2066         acpi_container_init();
2067         acpi_memory_hotplug_init();
2068         acpi_dock_init();
2069
2070         mutex_lock(&acpi_scan_lock);
2071         /*
2072          * Enumerate devices in the ACPI namespace.
2073          */
2074         result = acpi_bus_scan(ACPI_ROOT_OBJECT);
2075         if (result)
2076                 goto out;
2077
2078         result = acpi_bus_get_device(ACPI_ROOT_OBJECT, &acpi_root);
2079         if (result)
2080                 goto out;
2081
2082         result = acpi_bus_scan_fixed();
2083         if (result) {
2084                 acpi_detach_data(acpi_root->handle, acpi_scan_drop_device);
2085                 acpi_device_del(acpi_root);
2086                 put_device(&acpi_root->dev);
2087                 goto out;
2088         }
2089
2090         acpi_update_all_gpes();
2091
2092  out:
2093         mutex_unlock(&acpi_scan_lock);
2094         return result;
2095 }