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 #include <linux/dma-mapping.h>
  15
  16 #include <asm/pgtable.h>
  17
  18 #include "internal.h"
  19
  20 #define _COMPONENT              ACPI_BUS_COMPONENT
  21 ACPI_MODULE_NAME("scan");
  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 #define INVALID_ACPI_HANDLE     ((acpi_handle)empty_zero_page)
  31
  32 /*
  33  * If set, devices will be hot-removed even if they cannot be put offline
  34  * gracefully (from the kernel's standpoint).
  35  */
  36 bool acpi_force_hot_remove;
  37
  38 static const char *dummy_hid = "device";
  39
  40 static LIST_HEAD(acpi_dep_list);
  41 static DEFINE_MUTEX(acpi_dep_list_lock);
  42 static LIST_HEAD(acpi_bus_id_list);
  43 static DEFINE_MUTEX(acpi_scan_lock);
  44 static LIST_HEAD(acpi_scan_handlers_list);
  45 DEFINE_MUTEX(acpi_device_lock);
  46 LIST_HEAD(acpi_wakeup_device_list);
  47 static DEFINE_MUTEX(acpi_hp_context_lock);
  48
  49 struct acpi_dep_data {
  50         struct list_head node;
  51         acpi_handle master;
  52         acpi_handle slave;
  53 };
  54
  55 struct acpi_device_bus_id{
  56         char bus_id[15];
  57         unsigned int instance_no;
  58         struct list_head node;
  59 };
  60
  61 void acpi_scan_lock_acquire(void)
  62 {
  63         mutex_lock(&acpi_scan_lock);
  64 }
  65 EXPORT_SYMBOL_GPL(acpi_scan_lock_acquire);
  66
  67 void acpi_scan_lock_release(void)
  68 {
  69         mutex_unlock(&acpi_scan_lock);
  70 }
  71 EXPORT_SYMBOL_GPL(acpi_scan_lock_release);
  72
  73 void acpi_lock_hp_context(void)
  74 {
  75         mutex_lock(&acpi_hp_context_lock);
  76 }
  77
  78 void acpi_unlock_hp_context(void)
  79 {
  80         mutex_unlock(&acpi_hp_context_lock);
  81 }
  82
  83 void acpi_initialize_hp_context(struct acpi_device *adev,
  84                                 struct acpi_hotplug_context *hp,
  85                                 int (*notify)(struct acpi_device *, u32),
  86                                 void (*uevent)(struct acpi_device *, u32))
  87 {
  88         acpi_lock_hp_context();
  89         hp->notify = notify;
  90         hp->uevent = uevent;
  91         acpi_set_hp_context(adev, hp);
  92         acpi_unlock_hp_context();
  93 }
  94 EXPORT_SYMBOL_GPL(acpi_initialize_hp_context);
  95
  96 int acpi_scan_add_handler(struct acpi_scan_handler *handler)
  97 {
  98         if (!handler)
  99                 return -EINVAL;
 100
 101         list_add_tail(&handler->list_node, &acpi_scan_handlers_list);
 102         return 0;
 103 }
 104
 105 int acpi_scan_add_handler_with_hotplug(struct acpi_scan_handler *handler,
 106                                        const char *hotplug_profile_name)
 107 {
 108         int error;
 109
 110         error = acpi_scan_add_handler(handler);
 111         if (error)
 112                 return error;
 113
 114         acpi_sysfs_add_hotplug_profile(&handler->hotplug, hotplug_profile_name);
 115         return 0;
 116 }
 117
 118 /**
 119  * create_pnp_modalias - Create hid/cid(s) string for modalias and uevent
 120  * @acpi_dev: ACPI device object.
 121  * @modalias: Buffer to print into.
 122  * @size: Size of the buffer.
 123  *
 124  * Creates hid/cid(s) string needed for modalias and uevent
 125  * e.g. on a device with hid:IBM0001 and cid:ACPI0001 you get:
 126  * char *modalias: "acpi:IBM0001:ACPI0001"
 127  * Return: 0: no _HID and no _CID
 128  *         -EINVAL: output error
 129  *         -ENOMEM: output is truncated
 130 */
 131 static int create_pnp_modalias(struct acpi_device *acpi_dev, char *modalias,
 132                                int size)
 133 {
 134         int len;
 135         int count;
 136         struct acpi_hardware_id *id;
 137
 138         /*
 139          * Since we skip ACPI_DT_NAMESPACE_HID from the modalias below, 0 should
 140          * be returned if ACPI_DT_NAMESPACE_HID is the only ACPI/PNP ID in the
 141          * device's list.
 142          */
 143         count = 0;
 144         list_for_each_entry(id, &acpi_dev->pnp.ids, list)
 145                 if (strcmp(id->id, ACPI_DT_NAMESPACE_HID))
 146                         count++;
 147
 148         if (!count)
 149                 return 0;
 150
 151         len = snprintf(modalias, size, "acpi:");
 152         if (len <= 0)
 153                 return len;
 154
 155         size -= len;
 156
 157         list_for_each_entry(id, &acpi_dev->pnp.ids, list) {
 158                 if (!strcmp(id->id, ACPI_DT_NAMESPACE_HID))
 159                         continue;
 160
 161                 count = snprintf(&modalias[len], size, "%s:", id->id);
 162                 if (count < 0)
 163                         return -EINVAL;
 164
 165                 if (count >= size)
 166                         return -ENOMEM;
 167
 168                 len += count;
 169                 size -= count;
 170         }
 171         modalias[len] = '\0';
 172         return len;
 173 }
 174
 175 /**
 176  * create_of_modalias - Creates DT compatible string for modalias and uevent
 177  * @acpi_dev: ACPI device object.
 178  * @modalias: Buffer to print into.
 179  * @size: Size of the buffer.
 180  *
 181  * Expose DT compatible modalias as of:NnameTCcompatible.  This function should
 182  * only be called for devices having ACPI_DT_NAMESPACE_HID in their list of
 183  * ACPI/PNP IDs.
 184  */
 185 static int create_of_modalias(struct acpi_device *acpi_dev, char *modalias,
 186                               int size)
 187 {
 188         struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
 189         const union acpi_object *of_compatible, *obj;
 190         int len, count;
 191         int i, nval;
 192         char *c;
 193
 194         acpi_get_name(acpi_dev->handle, ACPI_SINGLE_NAME, &buf);
 195         /* DT strings are all in lower case */
 196         for (c = buf.pointer; *c != '\0'; c++)
 197                 *c = tolower(*c);
 198
 199         len = snprintf(modalias, size, "of:N%sT", (char *)buf.pointer);
 200         ACPI_FREE(buf.pointer);
 201
 202         if (len <= 0)
 203                 return len;
 204
 205         of_compatible = acpi_dev->data.of_compatible;
 206         if (of_compatible->type == ACPI_TYPE_PACKAGE) {
 207                 nval = of_compatible->package.count;
 208                 obj = of_compatible->package.elements;
 209         } else { /* Must be ACPI_TYPE_STRING. */
 210                 nval = 1;
 211                 obj = of_compatible;
 212         }
 213         for (i = 0; i < nval; i++, obj++) {
 214                 count = snprintf(&modalias[len], size, "C%s",
 215                                  obj->string.pointer);
 216                 if (count < 0)
 217                         return -EINVAL;
 218
 219                 if (count >= size)
 220                         return -ENOMEM;
 221
 222                 len += count;
 223                 size -= count;
 224         }
 225         modalias[len] = '\0';
 226         return len;
 227 }
 228
 229 /*
 230  * acpi_companion_match() - Can we match via ACPI companion device
 231  * @dev: Device in question
 232  *
 233  * Check if the given device has an ACPI companion and if that companion has
 234  * a valid list of PNP IDs, and if the device is the first (primary) physical
 235  * device associated with it.  Return the companion pointer if that's the case
 236  * or NULL otherwise.
 237  *
 238  * If multiple physical devices are attached to a single ACPI companion, we need
 239  * to be careful.  The usage scenario for this kind of relationship is that all
 240  * of the physical devices in question use resources provided by the ACPI
 241  * companion.  A typical case is an MFD device where all the sub-devices share
 242  * the parent's ACPI companion.  In such cases we can only allow the primary
 243  * (first) physical device to be matched with the help of the companion's PNP
 244  * IDs.
 245  *
 246  * Additional physical devices sharing the ACPI companion can still use
 247  * resources available from it but they will be matched normally using functions
 248  * provided by their bus types (and analogously for their modalias).
 249  */
 250 static struct acpi_device *acpi_companion_match(const struct device *dev)
 251 {
 252         struct acpi_device *adev;
 253         struct mutex *physical_node_lock;
 254
 255         adev = ACPI_COMPANION(dev);
 256         if (!adev)
 257                 return NULL;
 258
 259         if (list_empty(&adev->pnp.ids))
 260                 return NULL;
 261
 262         physical_node_lock = &adev->physical_node_lock;
 263         mutex_lock(physical_node_lock);
 264         if (list_empty(&adev->physical_node_list)) {
 265                 adev = NULL;
 266         } else {
 267                 const struct acpi_device_physical_node *node;
 268
 269                 node = list_first_entry(&adev->physical_node_list,
 270                                         struct acpi_device_physical_node, node);
 271                 if (node->dev != dev)
 272                         adev = NULL;
 273         }
 274         mutex_unlock(physical_node_lock);
 275
 276         return adev;
 277 }
 278
 279 static int __acpi_device_uevent_modalias(struct acpi_device *adev,
 280                                          struct kobj_uevent_env *env)
 281 {
 282         int len;
 283
 284         if (!adev)
 285                 return -ENODEV;
 286
 287         if (list_empty(&adev->pnp.ids))
 288                 return 0;
 289
 290         if (add_uevent_var(env, "MODALIAS="))
 291                 return -ENOMEM;
 292
 293         len = create_pnp_modalias(adev, &env->buf[env->buflen - 1],
 294                                   sizeof(env->buf) - env->buflen);
 295         if (len < 0)
 296                 return len;
 297
 298         env->buflen += len;
 299         if (!adev->data.of_compatible)
 300                 return 0;
 301
 302         if (len > 0 && add_uevent_var(env, "MODALIAS="))
 303                 return -ENOMEM;
 304
 305         len = create_of_modalias(adev, &env->buf[env->buflen - 1],
 306                                  sizeof(env->buf) - env->buflen);
 307         if (len < 0)
 308                 return len;
 309
 310         env->buflen += len;
 311
 312         return 0;
 313 }
 314
 315 /*
 316  * Creates uevent modalias field for ACPI enumerated devices.
 317  * Because the other buses does not support ACPI HIDs & CIDs.
 318  * e.g. for a device with hid:IBM0001 and cid:ACPI0001 you get:
 319  * "acpi:IBM0001:ACPI0001"
 320  */
 321 int acpi_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
 322 {
 323         return __acpi_device_uevent_modalias(acpi_companion_match(dev), env);
 324 }
 325 EXPORT_SYMBOL_GPL(acpi_device_uevent_modalias);
 326
 327 static int __acpi_device_modalias(struct acpi_device *adev, char *buf, int size)
 328 {
 329         int len, count;
 330
 331         if (!adev)
 332                 return -ENODEV;
 333
 334         if (list_empty(&adev->pnp.ids))
 335                 return 0;
 336
 337         len = create_pnp_modalias(adev, buf, size - 1);
 338         if (len < 0) {
 339                 return len;
 340         } else if (len > 0) {
 341                 buf[len++] = '\n';
 342                 size -= len;
 343         }
 344         if (!adev->data.of_compatible)
 345                 return len;
 346
 347         count = create_of_modalias(adev, buf + len, size - 1);
 348         if (count < 0) {
 349                 return count;
 350         } else if (count > 0) {
 351                 len += count;
 352                 buf[len++] = '\n';
 353         }
 354
 355         return len;
 356 }
 357
 358 /*
 359  * Creates modalias sysfs attribute for ACPI enumerated devices.
 360  * Because the other buses does not support ACPI HIDs & CIDs.
 361  * e.g. for a device with hid:IBM0001 and cid:ACPI0001 you get:
 362  * "acpi:IBM0001:ACPI0001"
 363  */
 364 int acpi_device_modalias(struct device *dev, char *buf, int size)
 365 {
 366         return __acpi_device_modalias(acpi_companion_match(dev), buf, size);
 367 }
 368 EXPORT_SYMBOL_GPL(acpi_device_modalias);
 369
 370 static ssize_t
 371 acpi_device_modalias_show(struct device *dev, struct device_attribute *attr, char *buf) {
 372         return __acpi_device_modalias(to_acpi_device(dev), buf, 1024);
 373 }
 374 static DEVICE_ATTR(modalias, 0444, acpi_device_modalias_show, NULL);
 375
 376 bool acpi_scan_is_offline(struct acpi_device *adev, bool uevent)
 377 {
 378         struct acpi_device_physical_node *pn;
 379         bool offline = true;
 380
 381         /*
 382          * acpi_container_offline() calls this for all of the container's
 383          * children under the container's physical_node_lock lock.
 384          */
 385         mutex_lock_nested(&adev->physical_node_lock, SINGLE_DEPTH_NESTING);
 386
 387         list_for_each_entry(pn, &adev->physical_node_list, node)
 388                 if (device_supports_offline(pn->dev) && !pn->dev->offline) {
 389                         if (uevent)
 390                                 kobject_uevent(&pn->dev->kobj, KOBJ_CHANGE);
 391
 392                         offline = false;
 393                         break;
 394                 }
 395
 396         mutex_unlock(&adev->physical_node_lock);
 397         return offline;
 398 }
 399
 400 static acpi_status acpi_bus_offline(acpi_handle handle, u32 lvl, void *data,
 401                                     void **ret_p)
 402 {
 403         struct acpi_device *device = NULL;
 404         struct acpi_device_physical_node *pn;
 405         bool second_pass = (bool)data;
 406         acpi_status status = AE_OK;
 407
 408         if (acpi_bus_get_device(handle, &device))
 409                 return AE_OK;
 410
 411         if (device->handler && !device->handler->hotplug.enabled) {
 412                 *ret_p = &device->dev;
 413                 return AE_SUPPORT;
 414         }
 415
 416         mutex_lock(&device->physical_node_lock);
 417
 418         list_for_each_entry(pn, &device->physical_node_list, node) {
 419                 int ret;
 420
 421                 if (second_pass) {
 422                         /* Skip devices offlined by the first pass. */
 423                         if (pn->put_online)
 424                                 continue;
 425                 } else {
 426                         pn->put_online = false;
 427                 }
 428                 ret = device_offline(pn->dev);
 429                 if (acpi_force_hot_remove)
 430                         continue;
 431
 432                 if (ret >= 0) {
 433                         pn->put_online = !ret;
 434                 } else {
 435                         *ret_p = pn->dev;
 436                         if (second_pass) {
 437                                 status = AE_ERROR;
 438                                 break;
 439                         }
 440                 }
 441         }
 442
 443         mutex_unlock(&device->physical_node_lock);
 444
 445         return status;
 446 }
 447
 448 static acpi_status acpi_bus_online(acpi_handle handle, u32 lvl, void *data,
 449                                    void **ret_p)
 450 {
 451         struct acpi_device *device = NULL;
 452         struct acpi_device_physical_node *pn;
 453
 454         if (acpi_bus_get_device(handle, &device))
 455                 return AE_OK;
 456
 457         mutex_lock(&device->physical_node_lock);
 458
 459         list_for_each_entry(pn, &device->physical_node_list, node)
 460                 if (pn->put_online) {
 461                         device_online(pn->dev);
 462                         pn->put_online = false;
 463                 }
 464
 465         mutex_unlock(&device->physical_node_lock);
 466
 467         return AE_OK;
 468 }
 469
 470 static int acpi_scan_try_to_offline(struct acpi_device *device)
 471 {
 472         acpi_handle handle = device->handle;
 473         struct device *errdev = NULL;
 474         acpi_status status;
 475
 476         /*
 477          * Carry out two passes here and ignore errors in the first pass,
 478          * because if the devices in question are memory blocks and
 479          * CONFIG_MEMCG is set, one of the blocks may hold data structures
 480          * that the other blocks depend on, but it is not known in advance which
 481          * block holds them.
 482          *
 483          * If the first pass is successful, the second one isn't needed, though.
 484          */
 485         status = acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
 486                                      NULL, acpi_bus_offline, (void *)false,
 487                                      (void **)&errdev);
 488         if (status == AE_SUPPORT) {
 489                 dev_warn(errdev, "Offline disabled.\n");
 490                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
 491                                     acpi_bus_online, NULL, NULL, NULL);
 492                 return -EPERM;
 493         }
 494         acpi_bus_offline(handle, 0, (void *)false, (void **)&errdev);
 495         if (errdev) {
 496                 errdev = NULL;
 497                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
 498                                     NULL, acpi_bus_offline, (void *)true,
 499                                     (void **)&errdev);
 500                 if (!errdev || acpi_force_hot_remove)
 501                         acpi_bus_offline(handle, 0, (void *)true,
 502                                          (void **)&errdev);
 503
 504                 if (errdev && !acpi_force_hot_remove) {
 505                         dev_warn(errdev, "Offline failed.\n");
 506                         acpi_bus_online(handle, 0, NULL, NULL);
 507                         acpi_walk_namespace(ACPI_TYPE_ANY, handle,
 508                                             ACPI_UINT32_MAX, acpi_bus_online,
 509                                             NULL, NULL, NULL);
 510                         return -EBUSY;
 511                 }
 512         }
 513         return 0;
 514 }
 515
 516 static int acpi_scan_hot_remove(struct acpi_device *device)
 517 {
 518         acpi_handle handle = device->handle;
 519         unsigned long long sta;
 520         acpi_status status;
 521
 522         if (device->handler && device->handler->hotplug.demand_offline
 523             && !acpi_force_hot_remove) {
 524                 if (!acpi_scan_is_offline(device, true))
 525                         return -EBUSY;
 526         } else {
 527                 int error = acpi_scan_try_to_offline(device);
 528                 if (error)
 529                         return error;
 530         }
 531
 532         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 533                 "Hot-removing device %s...\n", dev_name(&device->dev)));
 534
 535         acpi_bus_trim(device);
 536
 537         acpi_evaluate_lck(handle, 0);
 538         /*
 539          * TBD: _EJD support.
 540          */
 541         status = acpi_evaluate_ej0(handle);
 542         if (status == AE_NOT_FOUND)
 543                 return -ENODEV;
 544         else if (ACPI_FAILURE(status))
 545                 return -EIO;
 546
 547         /*
 548          * Verify if eject was indeed successful.  If not, log an error
 549          * message.  No need to call _OST since _EJ0 call was made OK.
 550          */
 551         status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
 552         if (ACPI_FAILURE(status)) {
 553                 acpi_handle_warn(handle,
 554                         "Status check after eject failed (0x%x)\n", status);
 555         } else if (sta & ACPI_STA_DEVICE_ENABLED) {
 556                 acpi_handle_warn(handle,
 557                         "Eject incomplete - status 0x%llx\n", sta);
 558         }
 559
 560         return 0;
 561 }
 562
 563 static int acpi_scan_device_not_present(struct acpi_device *adev)
 564 {
 565         if (!acpi_device_enumerated(adev)) {
 566                 dev_warn(&adev->dev, "Still not present\n");
 567                 return -EALREADY;
 568         }
 569         acpi_bus_trim(adev);
 570         return 0;
 571 }
 572
 573 static int acpi_scan_device_check(struct acpi_device *adev)
 574 {
 575         int error;
 576
 577         acpi_bus_get_status(adev);
 578         if (adev->status.present || adev->status.functional) {
 579                 /*
 580                  * This function is only called for device objects for which
 581                  * matching scan handlers exist.  The only situation in which
 582                  * the scan handler is not attached to this device object yet
 583                  * is when the device has just appeared (either it wasn't
 584                  * present at all before or it was removed and then added
 585                  * again).
 586                  */
 587                 if (adev->handler) {
 588                         dev_warn(&adev->dev, "Already enumerated\n");
 589                         return -EALREADY;
 590                 }
 591                 error = acpi_bus_scan(adev->handle);
 592                 if (error) {
 593                         dev_warn(&adev->dev, "Namespace scan failure\n");
 594                         return error;
 595                 }
 596                 if (!adev->handler) {
 597                         dev_warn(&adev->dev, "Enumeration failure\n");
 598                         error = -ENODEV;
 599                 }
 600         } else {
 601                 error = acpi_scan_device_not_present(adev);
 602         }
 603         return error;
 604 }
 605
 606 static int acpi_scan_bus_check(struct acpi_device *adev)
 607 {
 608         struct acpi_scan_handler *handler = adev->handler;
 609         struct acpi_device *child;
 610         int error;
 611
 612         acpi_bus_get_status(adev);
 613         if (!(adev->status.present || adev->status.functional)) {
 614                 acpi_scan_device_not_present(adev);
 615                 return 0;
 616         }
 617         if (handler && handler->hotplug.scan_dependent)
 618                 return handler->hotplug.scan_dependent(adev);
 619
 620         error = acpi_bus_scan(adev->handle);
 621         if (error) {
 622                 dev_warn(&adev->dev, "Namespace scan failure\n");
 623                 return error;
 624         }
 625         list_for_each_entry(child, &adev->children, node) {
 626                 error = acpi_scan_bus_check(child);
 627                 if (error)
 628                         return error;
 629         }
 630         return 0;
 631 }
 632
 633 static int acpi_generic_hotplug_event(struct acpi_device *adev, u32 type)
 634 {
 635         switch (type) {
 636         case ACPI_NOTIFY_BUS_CHECK:
 637                 return acpi_scan_bus_check(adev);
 638         case ACPI_NOTIFY_DEVICE_CHECK:
 639                 return acpi_scan_device_check(adev);
 640         case ACPI_NOTIFY_EJECT_REQUEST:
 641         case ACPI_OST_EC_OSPM_EJECT:
 642                 if (adev->handler && !adev->handler->hotplug.enabled) {
 643                         dev_info(&adev->dev, "Eject disabled\n");
 644                         return -EPERM;
 645                 }
 646                 acpi_evaluate_ost(adev->handle, ACPI_NOTIFY_EJECT_REQUEST,
 647                                   ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
 648                 return acpi_scan_hot_remove(adev);
 649         }
 650         return -EINVAL;
 651 }
 652
 653 void acpi_device_hotplug(struct acpi_device *adev, u32 src)
 654 {
 655         u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
 656         int error = -ENODEV;
 657
 658         lock_device_hotplug();
 659         mutex_lock(&acpi_scan_lock);
 660
 661         /*
 662          * The device object's ACPI handle cannot become invalid as long as we
 663          * are holding acpi_scan_lock, but it might have become invalid before
 664          * that lock was acquired.
 665          */
 666         if (adev->handle == INVALID_ACPI_HANDLE)
 667                 goto err_out;
 668
 669         if (adev->flags.is_dock_station) {
 670                 error = dock_notify(adev, src);
 671         } else if (adev->flags.hotplug_notify) {
 672                 error = acpi_generic_hotplug_event(adev, src);
 673                 if (error == -EPERM) {
 674                         ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
 675                         goto err_out;
 676                 }
 677         } else {
 678                 int (*notify)(struct acpi_device *, u32);
 679
 680                 acpi_lock_hp_context();
 681                 notify = adev->hp ? adev->hp->notify : NULL;
 682                 acpi_unlock_hp_context();
 683                 /*
 684                  * There may be additional notify handlers for device objects
 685                  * without the .event() callback, so ignore them here.
 686                  */
 687                 if (notify)
 688                         error = notify(adev, src);
 689                 else
 690                         goto out;
 691         }
 692         if (!error)
 693                 ost_code = ACPI_OST_SC_SUCCESS;
 694
 695  err_out:
 696         acpi_evaluate_ost(adev->handle, src, ost_code, NULL);
 697
 698  out:
 699         acpi_bus_put_acpi_device(adev);
 700         mutex_unlock(&acpi_scan_lock);
 701         unlock_device_hotplug();
 702 }
 703
 704 static ssize_t real_power_state_show(struct device *dev,
 705                                      struct device_attribute *attr, char *buf)
 706 {
 707         struct acpi_device *adev = to_acpi_device(dev);
 708         int state;
 709         int ret;
 710
 711         ret = acpi_device_get_power(adev, &state);
 712         if (ret)
 713                 return ret;
 714
 715         return sprintf(buf, "%s\n", acpi_power_state_string(state));
 716 }
 717
 718 static DEVICE_ATTR(real_power_state, 0444, real_power_state_show, NULL);
 719
 720 static ssize_t power_state_show(struct device *dev,
 721                                 struct device_attribute *attr, char *buf)
 722 {
 723         struct acpi_device *adev = to_acpi_device(dev);
 724
 725         return sprintf(buf, "%s\n", acpi_power_state_string(adev->power.state));
 726 }
 727
 728 static DEVICE_ATTR(power_state, 0444, power_state_show, NULL);
 729
 730 static ssize_t
 731 acpi_eject_store(struct device *d, struct device_attribute *attr,
 732                 const char *buf, size_t count)
 733 {
 734         struct acpi_device *acpi_device = to_acpi_device(d);
 735         acpi_object_type not_used;
 736         acpi_status status;
 737
 738         if (!count || buf[0] != '1')
 739                 return -EINVAL;
 740
 741         if ((!acpi_device->handler || !acpi_device->handler->hotplug.enabled)
 742             && !acpi_device->driver)
 743                 return -ENODEV;
 744
 745         status = acpi_get_type(acpi_device->handle, &not_used);
 746         if (ACPI_FAILURE(status) || !acpi_device->flags.ejectable)
 747                 return -ENODEV;
 748
 749         get_device(&acpi_device->dev);
 750         status = acpi_hotplug_schedule(acpi_device, ACPI_OST_EC_OSPM_EJECT);
 751         if (ACPI_SUCCESS(status))
 752                 return count;
 753
 754         put_device(&acpi_device->dev);
 755         acpi_evaluate_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,
 756                           ACPI_OST_SC_NON_SPECIFIC_FAILURE, NULL);
 757         return status == AE_NO_MEMORY ? -ENOMEM : -EAGAIN;
 758 }
 759
 760 static DEVICE_ATTR(eject, 0200, NULL, acpi_eject_store);
 761
 762 static ssize_t
 763 acpi_device_hid_show(struct device *dev, struct device_attribute *attr, char *buf) {
 764         struct acpi_device *acpi_dev = to_acpi_device(dev);
 765
 766         return sprintf(buf, "%s\n", acpi_device_hid(acpi_dev));
 767 }
 768 static DEVICE_ATTR(hid, 0444, acpi_device_hid_show, NULL);
 769
 770 static ssize_t acpi_device_uid_show(struct device *dev,
 771                                     struct device_attribute *attr, char *buf)
 772 {
 773         struct acpi_device *acpi_dev = to_acpi_device(dev);
 774
 775         return sprintf(buf, "%s\n", acpi_dev->pnp.unique_id);
 776 }
 777 static DEVICE_ATTR(uid, 0444, acpi_device_uid_show, NULL);
 778
 779 static ssize_t acpi_device_adr_show(struct device *dev,
 780                                     struct device_attribute *attr, char *buf)
 781 {
 782         struct acpi_device *acpi_dev = to_acpi_device(dev);
 783
 784         return sprintf(buf, "0x%08x\n",
 785                        (unsigned int)(acpi_dev->pnp.bus_address));
 786 }
 787 static DEVICE_ATTR(adr, 0444, acpi_device_adr_show, NULL);
 788
 789 static ssize_t
 790 acpi_device_path_show(struct device *dev, struct device_attribute *attr, char *buf) {
 791         struct acpi_device *acpi_dev = to_acpi_device(dev);
 792         struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
 793         int result;
 794
 795         result = acpi_get_name(acpi_dev->handle, ACPI_FULL_PATHNAME, &path);
 796         if (result)
 797                 goto end;
 798
 799         result = sprintf(buf, "%s\n", (char*)path.pointer);
 800         kfree(path.pointer);
 801 end:
 802         return result;
 803 }
 804 static DEVICE_ATTR(path, 0444, acpi_device_path_show, NULL);
 805
 806 /* sysfs file that shows description text from the ACPI _STR method */
 807 static ssize_t description_show(struct device *dev,
 808                                 struct device_attribute *attr,
 809                                 char *buf) {
 810         struct acpi_device *acpi_dev = to_acpi_device(dev);
 811         int result;
 812
 813         if (acpi_dev->pnp.str_obj == NULL)
 814                 return 0;
 815
 816         /*
 817          * The _STR object contains a Unicode identifier for a device.
 818          * We need to convert to utf-8 so it can be displayed.
 819          */
 820         result = utf16s_to_utf8s(
 821                 (wchar_t *)acpi_dev->pnp.str_obj->buffer.pointer,
 822                 acpi_dev->pnp.str_obj->buffer.length,
 823                 UTF16_LITTLE_ENDIAN, buf,
 824                 PAGE_SIZE);
 825
 826         buf[result++] = '\n';
 827
 828         return result;
 829 }
 830 static DEVICE_ATTR(description, 0444, description_show, NULL);
 831
 832 static ssize_t
 833 acpi_device_sun_show(struct device *dev, struct device_attribute *attr,
 834                      char *buf) {
 835         struct acpi_device *acpi_dev = to_acpi_device(dev);
 836         acpi_status status;
 837         unsigned long long sun;
 838
 839         status = acpi_evaluate_integer(acpi_dev->handle, "_SUN", NULL, &sun);
 840         if (ACPI_FAILURE(status))
 841                 return -ENODEV;
 842
 843         return sprintf(buf, "%llu\n", sun);
 844 }
 845 static DEVICE_ATTR(sun, 0444, acpi_device_sun_show, NULL);
 846
 847 static ssize_t status_show(struct device *dev, struct device_attribute *attr,
 848                                 char *buf) {
 849         struct acpi_device *acpi_dev = to_acpi_device(dev);
 850         acpi_status status;
 851         unsigned long long sta;
 852
 853         status = acpi_evaluate_integer(acpi_dev->handle, "_STA", NULL, &sta);
 854         if (ACPI_FAILURE(status))
 855                 return -ENODEV;
 856
 857         return sprintf(buf, "%llu\n", sta);
 858 }
 859 static DEVICE_ATTR_RO(status);
 860
 861 static int acpi_device_setup_files(struct acpi_device *dev)
 862 {
 863         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
 864         acpi_status status;
 865         int result = 0;
 866
 867         /*
 868          * Devices gotten from FADT don't have a "path" attribute
 869          */
 870         if (dev->handle) {
 871                 result = device_create_file(&dev->dev, &dev_attr_path);
 872                 if (result)
 873                         goto end;
 874         }
 875
 876         if (!list_empty(&dev->pnp.ids)) {
 877                 result = device_create_file(&dev->dev, &dev_attr_hid);
 878                 if (result)
 879                         goto end;
 880
 881                 result = device_create_file(&dev->dev, &dev_attr_modalias);
 882                 if (result)
 883                         goto end;
 884         }
 885
 886         /*
 887          * If device has _STR, 'description' file is created
 888          */
 889         if (acpi_has_method(dev->handle, "_STR")) {
 890                 status = acpi_evaluate_object(dev->handle, "_STR",
 891                                         NULL, &buffer);
 892                 if (ACPI_FAILURE(status))
 893                         buffer.pointer = NULL;
 894                 dev->pnp.str_obj = buffer.pointer;
 895                 result = device_create_file(&dev->dev, &dev_attr_description);
 896                 if (result)
 897                         goto end;
 898         }
 899
 900         if (dev->pnp.type.bus_address)
 901                 result = device_create_file(&dev->dev, &dev_attr_adr);
 902         if (dev->pnp.unique_id)
 903                 result = device_create_file(&dev->dev, &dev_attr_uid);
 904
 905         if (acpi_has_method(dev->handle, "_SUN")) {
 906                 result = device_create_file(&dev->dev, &dev_attr_sun);
 907                 if (result)
 908                         goto end;
 909         }
 910
 911         if (acpi_has_method(dev->handle, "_STA")) {
 912                 result = device_create_file(&dev->dev, &dev_attr_status);
 913                 if (result)
 914                         goto end;
 915         }
 916
 917         /*
 918          * If device has _EJ0, 'eject' file is created that is used to trigger
 919          * hot-removal function from userland.
 920          */
 921         if (acpi_has_method(dev->handle, "_EJ0")) {
 922                 result = device_create_file(&dev->dev, &dev_attr_eject);
 923                 if (result)
 924                         return result;
 925         }
 926
 927         if (dev->flags.power_manageable) {
 928                 result = device_create_file(&dev->dev, &dev_attr_power_state);
 929                 if (result)
 930                         return result;
 931
 932                 if (dev->power.flags.power_resources)
 933                         result = device_create_file(&dev->dev,
 934                                                     &dev_attr_real_power_state);
 935         }
 936
 937 end:
 938         return result;
 939 }
 940
 941 static void acpi_device_remove_files(struct acpi_device *dev)
 942 {
 943         if (dev->flags.power_manageable) {
 944                 device_remove_file(&dev->dev, &dev_attr_power_state);
 945                 if (dev->power.flags.power_resources)
 946                         device_remove_file(&dev->dev,
 947                                            &dev_attr_real_power_state);
 948         }
 949
 950         /*
 951          * If device has _STR, remove 'description' file
 952          */
 953         if (acpi_has_method(dev->handle, "_STR")) {
 954                 kfree(dev->pnp.str_obj);
 955                 device_remove_file(&dev->dev, &dev_attr_description);
 956         }
 957         /*
 958          * If device has _EJ0, remove 'eject' file.
 959          */
 960         if (acpi_has_method(dev->handle, "_EJ0"))
 961                 device_remove_file(&dev->dev, &dev_attr_eject);
 962
 963         if (acpi_has_method(dev->handle, "_SUN"))
 964                 device_remove_file(&dev->dev, &dev_attr_sun);
 965
 966         if (dev->pnp.unique_id)
 967                 device_remove_file(&dev->dev, &dev_attr_uid);
 968         if (dev->pnp.type.bus_address)
 969                 device_remove_file(&dev->dev, &dev_attr_adr);
 970         device_remove_file(&dev->dev, &dev_attr_modalias);
 971         device_remove_file(&dev->dev, &dev_attr_hid);
 972         if (acpi_has_method(dev->handle, "_STA"))
 973                 device_remove_file(&dev->dev, &dev_attr_status);
 974         if (dev->handle)
 975                 device_remove_file(&dev->dev, &dev_attr_path);
 976 }
 977 /* --------------------------------------------------------------------------
 978                         ACPI Bus operations
 979    -------------------------------------------------------------------------- */
 980
 981 /**
 982  * acpi_of_match_device - Match device object using the "compatible" property.
 983  * @adev: ACPI device object to match.
 984  * @of_match_table: List of device IDs to match against.
 985  *
 986  * If @dev has an ACPI companion which has ACPI_DT_NAMESPACE_HID in its list of
 987  * identifiers and a _DSD object with the "compatible" property, use that
 988  * property to match against the given list of identifiers.
 989  */
 990 static bool acpi_of_match_device(struct acpi_device *adev,
 991                                  const struct of_device_id *of_match_table)
 992 {
 993         const union acpi_object *of_compatible, *obj;
 994         int i, nval;
 995
 996         if (!adev)
 997                 return false;
 998
 999         of_compatible = adev->data.of_compatible;
1000         if (!of_match_table || !of_compatible)
1001                 return false;
1002
1003         if (of_compatible->type == ACPI_TYPE_PACKAGE) {
1004                 nval = of_compatible->package.count;
1005                 obj = of_compatible->package.elements;
1006         } else { /* Must be ACPI_TYPE_STRING. */
1007                 nval = 1;
1008                 obj = of_compatible;
1009         }
1010         /* Now we can look for the driver DT compatible strings */
1011         for (i = 0; i < nval; i++, obj++) {
1012                 const struct of_device_id *id;
1013
1014                 for (id = of_match_table; id->compatible[0]; id++)
1015                         if (!strcasecmp(obj->string.pointer, id->compatible))
1016                                 return true;
1017         }
1018
1019         return false;
1020 }
1021
1022 static bool __acpi_match_device_cls(const struct acpi_device_id *id,
1023                                     struct acpi_hardware_id *hwid)
1024 {
1025         int i, msk, byte_shift;
1026         char buf[3];
1027
1028         if (!id->cls)
1029                 return false;
1030
1031         /* Apply class-code bitmask, before checking each class-code byte */
1032         for (i = 1; i <= 3; i++) {
1033                 byte_shift = 8 * (3 - i);
1034                 msk = (id->cls_msk >> byte_shift) & 0xFF;
1035                 if (!msk)
1036                         continue;
1037
1038                 sprintf(buf, "%02x", (id->cls >> byte_shift) & msk);
1039                 if (strncmp(buf, &hwid->id[(i - 1) * 2], 2))
1040                         return false;
1041         }
1042         return true;
1043 }
1044
1045 static const struct acpi_device_id *__acpi_match_device(
1046         struct acpi_device *device,
1047         const struct acpi_device_id *ids,
1048         const struct of_device_id *of_ids)
1049 {
1050         const struct acpi_device_id *id;
1051         struct acpi_hardware_id *hwid;
1052
1053         /*
1054          * If the device is not present, it is unnecessary to load device
1055          * driver for it.
1056          */
1057         if (!device || !device->status.present)
1058                 return NULL;
1059
1060         list_for_each_entry(hwid, &device->pnp.ids, list) {
1061                 /* First, check the ACPI/PNP IDs provided by the caller. */
1062                 for (id = ids; id->id[0] || id->cls; id++) {
1063                         if (id->id[0] && !strcmp((char *) id->id, hwid->id))
1064                                 return id;
1065                         else if (id->cls && __acpi_match_device_cls(id, hwid))
1066                                 return id;
1067                 }
1068
1069                 /*
1070                  * Next, check ACPI_DT_NAMESPACE_HID and try to match the
1071                  * "compatible" property if found.
1072                  *
1073                  * The id returned by the below is not valid, but the only
1074                  * caller passing non-NULL of_ids here is only interested in
1075                  * whether or not the return value is NULL.
1076                  */
1077                 if (!strcmp(ACPI_DT_NAMESPACE_HID, hwid->id)
1078                     && acpi_of_match_device(device, of_ids))
1079                         return id;
1080         }
1081         return NULL;
1082 }
1083
1084 /**
1085  * acpi_match_device - Match a struct device against a given list of ACPI IDs
1086  * @ids: Array of struct acpi_device_id object to match against.
1087  * @dev: The device structure to match.
1088  *
1089  * Check if @dev has a valid ACPI handle and if there is a struct acpi_device
1090  * object for that handle and use that object to match against a given list of
1091  * device IDs.
1092  *
1093  * Return a pointer to the first matching ID on success or %NULL on failure.
1094  */
1095 const struct acpi_device_id *acpi_match_device(const struct acpi_device_id *ids,
1096                                                const struct device *dev)
1097 {
1098         return __acpi_match_device(acpi_companion_match(dev), ids, NULL);
1099 }
1100 EXPORT_SYMBOL_GPL(acpi_match_device);
1101
1102 int acpi_match_device_ids(struct acpi_device *device,
1103                           const struct acpi_device_id *ids)
1104 {
1105         return __acpi_match_device(device, ids, NULL) ? 0 : -ENOENT;
1106 }
1107 EXPORT_SYMBOL(acpi_match_device_ids);
1108
1109 bool acpi_driver_match_device(struct device *dev,
1110                               const struct device_driver *drv)
1111 {
1112         if (!drv->acpi_match_table)
1113                 return acpi_of_match_device(ACPI_COMPANION(dev),
1114                                             drv->of_match_table);
1115
1116         return !!__acpi_match_device(acpi_companion_match(dev),
1117                                      drv->acpi_match_table, drv->of_match_table);
1118 }
1119 EXPORT_SYMBOL_GPL(acpi_driver_match_device);
1120
1121 static void acpi_free_power_resources_lists(struct acpi_device *device)
1122 {
1123         int i;
1124
1125         if (device->wakeup.flags.valid)
1126                 acpi_power_resources_list_free(&device->wakeup.resources);
1127
1128         if (!device->power.flags.power_resources)
1129                 return;
1130
1131         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
1132                 struct acpi_device_power_state *ps = &device->power.states[i];
1133                 acpi_power_resources_list_free(&ps->resources);
1134         }
1135 }
1136
1137 static void acpi_device_release(struct device *dev)
1138 {
1139         struct acpi_device *acpi_dev = to_acpi_device(dev);
1140
1141         acpi_free_properties(acpi_dev);
1142         acpi_free_pnp_ids(&acpi_dev->pnp);
1143         acpi_free_power_resources_lists(acpi_dev);
1144         kfree(acpi_dev);
1145 }
1146
1147 static int acpi_bus_match(struct device *dev, struct device_driver *drv)
1148 {
1149         struct acpi_device *acpi_dev = to_acpi_device(dev);
1150         struct acpi_driver *acpi_drv = to_acpi_driver(drv);
1151
1152         return acpi_dev->flags.match_driver
1153                 && !acpi_match_device_ids(acpi_dev, acpi_drv->ids);
1154 }
1155
1156 static int acpi_device_uevent(struct device *dev, struct kobj_uevent_env *env)
1157 {
1158         return __acpi_device_uevent_modalias(to_acpi_device(dev), env);
1159 }
1160
1161 static void acpi_device_notify(acpi_handle handle, u32 event, void *data)
1162 {
1163         struct acpi_device *device = data;
1164
1165         device->driver->ops.notify(device, event);
1166 }
1167
1168 static void acpi_device_notify_fixed(void *data)
1169 {
1170         struct acpi_device *device = data;
1171
1172         /* Fixed hardware devices have no handles */
1173         acpi_device_notify(NULL, ACPI_FIXED_HARDWARE_EVENT, device);
1174 }
1175
1176 static u32 acpi_device_fixed_event(void *data)
1177 {
1178         acpi_os_execute(OSL_NOTIFY_HANDLER, acpi_device_notify_fixed, data);
1179         return ACPI_INTERRUPT_HANDLED;
1180 }
1181
1182 static int acpi_device_install_notify_handler(struct acpi_device *device)
1183 {
1184         acpi_status status;
1185
1186         if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
1187                 status =
1188                     acpi_install_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
1189                                                      acpi_device_fixed_event,
1190                                                      device);
1191         else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
1192                 status =
1193                     acpi_install_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
1194                                                      acpi_device_fixed_event,
1195                                                      device);
1196         else
1197                 status = acpi_install_notify_handler(device->handle,
1198                                                      ACPI_DEVICE_NOTIFY,
1199                                                      acpi_device_notify,
1200                                                      device);
1201
1202         if (ACPI_FAILURE(status))
1203                 return -EINVAL;
1204         return 0;
1205 }
1206
1207 static void acpi_device_remove_notify_handler(struct acpi_device *device)
1208 {
1209         if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
1210                 acpi_remove_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
1211                                                 acpi_device_fixed_event);
1212         else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
1213                 acpi_remove_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
1214                                                 acpi_device_fixed_event);
1215         else
1216                 acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
1217                                            acpi_device_notify);
1218 }
1219
1220 static int acpi_device_probe(struct device *dev)
1221 {
1222         struct acpi_device *acpi_dev = to_acpi_device(dev);
1223         struct acpi_driver *acpi_drv = to_acpi_driver(dev->driver);
1224         int ret;
1225
1226         if (acpi_dev->handler && !acpi_is_pnp_device(acpi_dev))
1227                 return -EINVAL;
1228
1229         if (!acpi_drv->ops.add)
1230                 return -ENOSYS;
1231
1232         ret = acpi_drv->ops.add(acpi_dev);
1233         if (ret)
1234                 return ret;
1235
1236         acpi_dev->driver = acpi_drv;
1237         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1238                           "Driver [%s] successfully bound to device [%s]\n",
1239                           acpi_drv->name, acpi_dev->pnp.bus_id));
1240
1241         if (acpi_drv->ops.notify) {
1242                 ret = acpi_device_install_notify_handler(acpi_dev);
1243                 if (ret) {
1244                         if (acpi_drv->ops.remove)
1245                                 acpi_drv->ops.remove(acpi_dev);
1246
1247                         acpi_dev->driver = NULL;
1248                         acpi_dev->driver_data = NULL;
1249                         return ret;
1250                 }
1251         }
1252
1253         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found driver [%s] for device [%s]\n",
1254                           acpi_drv->name, acpi_dev->pnp.bus_id));
1255         get_device(dev);
1256         return 0;
1257 }
1258
1259 static int acpi_device_remove(struct device * dev)
1260 {
1261         struct acpi_device *acpi_dev = to_acpi_device(dev);
1262         struct acpi_driver *acpi_drv = acpi_dev->driver;
1263
1264         if (acpi_drv) {
1265                 if (acpi_drv->ops.notify)
1266                         acpi_device_remove_notify_handler(acpi_dev);
1267                 if (acpi_drv->ops.remove)
1268                         acpi_drv->ops.remove(acpi_dev);
1269         }
1270         acpi_dev->driver = NULL;
1271         acpi_dev->driver_data = NULL;
1272
1273         put_device(dev);
1274         return 0;
1275 }
1276
1277 struct bus_type acpi_bus_type = {
1278         .name           = "acpi",
1279         .match          = acpi_bus_match,
1280         .probe          = acpi_device_probe,
1281         .remove         = acpi_device_remove,
1282         .uevent         = acpi_device_uevent,
1283 };
1284
1285 static void acpi_device_del(struct acpi_device *device)
1286 {
1287         mutex_lock(&acpi_device_lock);
1288         if (device->parent)
1289                 list_del(&device->node);
1290
1291         list_del(&device->wakeup_list);
1292         mutex_unlock(&acpi_device_lock);
1293
1294         acpi_power_add_remove_device(device, false);
1295         acpi_device_remove_files(device);
1296         if (device->remove)
1297                 device->remove(device);
1298
1299         device_del(&device->dev);
1300 }
1301
1302 static LIST_HEAD(acpi_device_del_list);
1303 static DEFINE_MUTEX(acpi_device_del_lock);
1304
1305 static void acpi_device_del_work_fn(struct work_struct *work_not_used)
1306 {
1307         for (;;) {
1308                 struct acpi_device *adev;
1309
1310                 mutex_lock(&acpi_device_del_lock);
1311
1312                 if (list_empty(&acpi_device_del_list)) {
1313                         mutex_unlock(&acpi_device_del_lock);
1314                         break;
1315                 }
1316                 adev = list_first_entry(&acpi_device_del_list,
1317                                         struct acpi_device, del_list);
1318                 list_del(&adev->del_list);
1319
1320                 mutex_unlock(&acpi_device_del_lock);
1321
1322                 acpi_device_del(adev);
1323                 /*
1324                  * Drop references to all power resources that might have been
1325                  * used by the device.
1326                  */
1327                 acpi_power_transition(adev, ACPI_STATE_D3_COLD);
1328                 put_device(&adev->dev);
1329         }
1330 }
1331
1332 /**
1333  * acpi_scan_drop_device - Drop an ACPI device object.
1334  * @handle: Handle of an ACPI namespace node, not used.
1335  * @context: Address of the ACPI device object to drop.
1336  *
1337  * This is invoked by acpi_ns_delete_node() during the removal of the ACPI
1338  * namespace node the device object pointed to by @context is attached to.
1339  *
1340  * The unregistration is carried out asynchronously to avoid running
1341  * acpi_device_del() under the ACPICA's namespace mutex and the list is used to
1342  * ensure the correct ordering (the device objects must be unregistered in the
1343  * same order in which the corresponding namespace nodes are deleted).
1344  */
1345 static void acpi_scan_drop_device(acpi_handle handle, void *context)
1346 {
1347         static DECLARE_WORK(work, acpi_device_del_work_fn);
1348         struct acpi_device *adev = context;
1349
1350         mutex_lock(&acpi_device_del_lock);
1351
1352         /*
1353          * Use the ACPI hotplug workqueue which is ordered, so this work item
1354          * won't run after any hotplug work items submitted subsequently.  That
1355          * prevents attempts to register device objects identical to those being
1356          * deleted from happening concurrently (such attempts result from
1357          * hotplug events handled via the ACPI hotplug workqueue).  It also will
1358          * run after all of the work items submitted previosuly, which helps
1359          * those work items to ensure that they are not accessing stale device
1360          * objects.
1361          */
1362         if (list_empty(&acpi_device_del_list))
1363                 acpi_queue_hotplug_work(&work);
1364
1365         list_add_tail(&adev->del_list, &acpi_device_del_list);
1366         /* Make acpi_ns_validate_handle() return NULL for this handle. */
1367         adev->handle = INVALID_ACPI_HANDLE;
1368
1369         mutex_unlock(&acpi_device_del_lock);
1370 }
1371
1372 static int acpi_get_device_data(acpi_handle handle, struct acpi_device **device,
1373                                 void (*callback)(void *))
1374 {
1375         acpi_status status;
1376
1377         if (!device)
1378                 return -EINVAL;
1379
1380         status = acpi_get_data_full(handle, acpi_scan_drop_device,
1381                                     (void **)device, callback);
1382         if (ACPI_FAILURE(status) || !*device) {
1383                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No context for object [%p]\n",
1384                                   handle));
1385                 return -ENODEV;
1386         }
1387         return 0;
1388 }
1389
1390 int acpi_bus_get_device(acpi_handle handle, struct acpi_device **device)
1391 {
1392         return acpi_get_device_data(handle, device, NULL);
1393 }
1394 EXPORT_SYMBOL(acpi_bus_get_device);
1395
1396 static void get_acpi_device(void *dev)
1397 {
1398         if (dev)
1399                 get_device(&((struct acpi_device *)dev)->dev);
1400 }
1401
1402 struct acpi_device *acpi_bus_get_acpi_device(acpi_handle handle)
1403 {
1404         struct acpi_device *adev = NULL;
1405
1406         acpi_get_device_data(handle, &adev, get_acpi_device);
1407         return adev;
1408 }
1409
1410 void acpi_bus_put_acpi_device(struct acpi_device *adev)
1411 {
1412         put_device(&adev->dev);
1413 }
1414
1415 int acpi_device_add(struct acpi_device *device,
1416                     void (*release)(struct device *))
1417 {
1418         int result;
1419         struct acpi_device_bus_id *acpi_device_bus_id, *new_bus_id;
1420         int found = 0;
1421
1422         if (device->handle) {
1423                 acpi_status status;
1424
1425                 status = acpi_attach_data(device->handle, acpi_scan_drop_device,
1426                                           device);
1427                 if (ACPI_FAILURE(status)) {
1428                         acpi_handle_err(device->handle,
1429                                         "Unable to attach device data\n");
1430                         return -ENODEV;
1431                 }
1432         }
1433
1434         /*
1435          * Linkage
1436          * -------
1437          * Link this device to its parent and siblings.
1438          */
1439         INIT_LIST_HEAD(&device->children);
1440         INIT_LIST_HEAD(&device->node);
1441         INIT_LIST_HEAD(&device->wakeup_list);
1442         INIT_LIST_HEAD(&device->physical_node_list);
1443         INIT_LIST_HEAD(&device->del_list);
1444         mutex_init(&device->physical_node_lock);
1445
1446         new_bus_id = kzalloc(sizeof(struct acpi_device_bus_id), GFP_KERNEL);
1447         if (!new_bus_id) {
1448                 pr_err(PREFIX "Memory allocation error\n");
1449                 result = -ENOMEM;
1450                 goto err_detach;
1451         }
1452
1453         mutex_lock(&acpi_device_lock);
1454         /*
1455          * Find suitable bus_id and instance number in acpi_bus_id_list
1456          * If failed, create one and link it into acpi_bus_id_list
1457          */
1458         list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
1459                 if (!strcmp(acpi_device_bus_id->bus_id,
1460                             acpi_device_hid(device))) {
1461                         acpi_device_bus_id->instance_no++;
1462                         found = 1;
1463                         kfree(new_bus_id);
1464                         break;
1465                 }
1466         }
1467         if (!found) {
1468                 acpi_device_bus_id = new_bus_id;
1469                 strcpy(acpi_device_bus_id->bus_id, acpi_device_hid(device));
1470                 acpi_device_bus_id->instance_no = 0;
1471                 list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
1472         }
1473         dev_set_name(&device->dev, "%s:%02x", acpi_device_bus_id->bus_id, acpi_device_bus_id->instance_no);
1474
1475         if (device->parent)
1476                 list_add_tail(&device->node, &device->parent->children);
1477
1478         if (device->wakeup.flags.valid)
1479                 list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);
1480         mutex_unlock(&acpi_device_lock);
1481
1482         if (device->parent)
1483                 device->dev.parent = &device->parent->dev;
1484         device->dev.bus = &acpi_bus_type;
1485         device->dev.release = release;
1486         result = device_add(&device->dev);
1487         if (result) {
1488                 dev_err(&device->dev, "Error registering device\n");
1489                 goto err;
1490         }
1491
1492         result = acpi_device_setup_files(device);
1493         if (result)
1494                 printk(KERN_ERR PREFIX "Error creating sysfs interface for device %s\n",
1495                        dev_name(&device->dev));
1496
1497         return 0;
1498
1499  err:
1500         mutex_lock(&acpi_device_lock);
1501         if (device->parent)
1502                 list_del(&device->node);
1503         list_del(&device->wakeup_list);
1504         mutex_unlock(&acpi_device_lock);
1505
1506  err_detach:
1507         acpi_detach_data(device->handle, acpi_scan_drop_device);
1508         return result;
1509 }
1510
1511 struct acpi_device *acpi_get_next_child(struct device *dev,
1512                                         struct acpi_device *child)
1513 {
1514         struct acpi_device *adev = ACPI_COMPANION(dev);
1515         struct list_head *head, *next;
1516
1517         if (!adev)
1518                 return NULL;
1519
1520         head = &adev->children;
1521         if (list_empty(head))
1522                 return NULL;
1523
1524         if (!child)
1525                 return list_first_entry(head, struct acpi_device, node);
1526
1527         next = child->node.next;
1528         return next == head ? NULL : list_entry(next, struct acpi_device, node);
1529 }
1530
1531 /* --------------------------------------------------------------------------
1532                                  Driver Management
1533    -------------------------------------------------------------------------- */
1534 /**
1535  * acpi_bus_register_driver - register a driver with the ACPI bus
1536  * @driver: driver being registered
1537  *
1538  * Registers a driver with the ACPI bus.  Searches the namespace for all
1539  * devices that match the driver's criteria and binds.  Returns zero for
1540  * success or a negative error status for failure.
1541  */
1542 int acpi_bus_register_driver(struct acpi_driver *driver)
1543 {
1544         int ret;
1545
1546         if (acpi_disabled)
1547                 return -ENODEV;
1548         driver->drv.name = driver->name;
1549         driver->drv.bus = &acpi_bus_type;
1550         driver->drv.owner = driver->owner;
1551
1552         ret = driver_register(&driver->drv);
1553         return ret;
1554 }
1555
1556 EXPORT_SYMBOL(acpi_bus_register_driver);
1557
1558 /**
1559  * acpi_bus_unregister_driver - unregisters a driver with the ACPI bus
1560  * @driver: driver to unregister
1561  *
1562  * Unregisters a driver with the ACPI bus.  Searches the namespace for all
1563  * devices that match the driver's criteria and unbinds.
1564  */
1565 void acpi_bus_unregister_driver(struct acpi_driver *driver)
1566 {
1567         driver_unregister(&driver->drv);
1568 }
1569
1570 EXPORT_SYMBOL(acpi_bus_unregister_driver);
1571
1572 /* --------------------------------------------------------------------------
1573                                  Device Enumeration
1574    -------------------------------------------------------------------------- */
1575 static struct acpi_device *acpi_bus_get_parent(acpi_handle handle)
1576 {
1577         struct acpi_device *device = NULL;
1578         acpi_status status;
1579
1580         /*
1581          * Fixed hardware devices do not appear in the namespace and do not
1582          * have handles, but we fabricate acpi_devices for them, so we have
1583          * to deal with them specially.
1584          */
1585         if (!handle)
1586                 return acpi_root;
1587
1588         do {
1589                 status = acpi_get_parent(handle, &handle);
1590                 if (ACPI_FAILURE(status))
1591                         return status == AE_NULL_ENTRY ? NULL : acpi_root;
1592         } while (acpi_bus_get_device(handle, &device));
1593         return device;
1594 }
1595
1596 acpi_status
1597 acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
1598 {
1599         acpi_status status;
1600         acpi_handle tmp;
1601         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
1602         union acpi_object *obj;
1603
1604         status = acpi_get_handle(handle, "_EJD", &tmp);
1605         if (ACPI_FAILURE(status))
1606                 return status;
1607
1608         status = acpi_evaluate_object(handle, "_EJD", NULL, &buffer);
1609         if (ACPI_SUCCESS(status)) {
1610                 obj = buffer.pointer;
1611                 status = acpi_get_handle(ACPI_ROOT_OBJECT, obj->string.pointer,
1612                                          ejd);
1613                 kfree(buffer.pointer);
1614         }
1615         return status;
1616 }
1617 EXPORT_SYMBOL_GPL(acpi_bus_get_ejd);
1618
1619 static int acpi_bus_extract_wakeup_device_power_package(acpi_handle handle,
1620                                         struct acpi_device_wakeup *wakeup)
1621 {
1622         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1623         union acpi_object *package = NULL;
1624         union acpi_object *element = NULL;
1625         acpi_status status;
1626         int err = -ENODATA;
1627
1628         if (!wakeup)
1629                 return -EINVAL;
1630
1631         INIT_LIST_HEAD(&wakeup->resources);
1632
1633         /* _PRW */
1634         status = acpi_evaluate_object(handle, "_PRW", NULL, &buffer);
1635         if (ACPI_FAILURE(status)) {
1636                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRW"));
1637                 return err;
1638         }
1639
1640         package = (union acpi_object *)buffer.pointer;
1641
1642         if (!package || package->package.count < 2)
1643                 goto out;
1644
1645         element = &(package->package.elements[0]);
1646         if (!element)
1647                 goto out;
1648
1649         if (element->type == ACPI_TYPE_PACKAGE) {
1650                 if ((element->package.count < 2) ||
1651                     (element->package.elements[0].type !=
1652                      ACPI_TYPE_LOCAL_REFERENCE)
1653                     || (element->package.elements[1].type != ACPI_TYPE_INTEGER))
1654                         goto out;
1655
1656                 wakeup->gpe_device =
1657                     element->package.elements[0].reference.handle;
1658                 wakeup->gpe_number =
1659                     (u32) element->package.elements[1].integer.value;
1660         } else if (element->type == ACPI_TYPE_INTEGER) {
1661                 wakeup->gpe_device = NULL;
1662                 wakeup->gpe_number = element->integer.value;
1663         } else {
1664                 goto out;
1665         }
1666
1667         element = &(package->package.elements[1]);
1668         if (element->type != ACPI_TYPE_INTEGER)
1669                 goto out;
1670
1671         wakeup->sleep_state = element->integer.value;
1672
1673         err = acpi_extract_power_resources(package, 2, &wakeup->resources);
1674         if (err)
1675                 goto out;
1676
1677         if (!list_empty(&wakeup->resources)) {
1678                 int sleep_state;
1679
1680                 err = acpi_power_wakeup_list_init(&wakeup->resources,
1681                                                   &sleep_state);
1682                 if (err) {
1683                         acpi_handle_warn(handle, "Retrieving current states "
1684                                          "of wakeup power resources failed\n");
1685                         acpi_power_resources_list_free(&wakeup->resources);
1686                         goto out;
1687                 }
1688                 if (sleep_state < wakeup->sleep_state) {
1689                         acpi_handle_warn(handle, "Overriding _PRW sleep state "
1690                                          "(S%d) by S%d from power resources\n",
1691                                          (int)wakeup->sleep_state, sleep_state);
1692                         wakeup->sleep_state = sleep_state;
1693                 }
1694         }
1695
1696  out:
1697         kfree(buffer.pointer);
1698         return err;
1699 }
1700
1701 static void acpi_wakeup_gpe_init(struct acpi_device *device)
1702 {
1703         static const struct acpi_device_id button_device_ids[] = {
1704                 {"PNP0C0C", 0},
1705                 {"PNP0C0D", 0},
1706                 {"PNP0C0E", 0},
1707                 {"", 0},
1708         };
1709         struct acpi_device_wakeup *wakeup = &device->wakeup;
1710         acpi_status status;
1711         acpi_event_status event_status;
1712
1713         wakeup->flags.notifier_present = 0;
1714
1715         /* Power button, Lid switch always enable wakeup */
1716         if (!acpi_match_device_ids(device, button_device_ids)) {
1717                 wakeup->flags.run_wake = 1;
1718                 if (!acpi_match_device_ids(device, &button_device_ids[1])) {
1719                         /* Do not use Lid/sleep button for S5 wakeup */
1720                         if (wakeup->sleep_state == ACPI_STATE_S5)
1721                                 wakeup->sleep_state = ACPI_STATE_S4;
1722                 }
1723                 acpi_mark_gpe_for_wake(wakeup->gpe_device, wakeup->gpe_number);
1724                 device_set_wakeup_capable(&device->dev, true);
1725                 return;
1726         }
1727
1728         acpi_setup_gpe_for_wake(device->handle, wakeup->gpe_device,
1729                                 wakeup->gpe_number);
1730         status = acpi_get_gpe_status(wakeup->gpe_device, wakeup->gpe_number,
1731                                      &event_status);
1732         if (ACPI_FAILURE(status))
1733                 return;
1734
1735         wakeup->flags.run_wake = !!(event_status & ACPI_EVENT_FLAG_HAS_HANDLER);
1736 }
1737
1738 static void acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
1739 {
1740         int err;
1741
1742         /* Presence of _PRW indicates wake capable */
1743         if (!acpi_has_method(device->handle, "_PRW"))
1744                 return;
1745
1746         err = acpi_bus_extract_wakeup_device_power_package(device->handle,
1747                                                            &device->wakeup);
1748         if (err) {
1749                 dev_err(&device->dev, "_PRW evaluation error: %d\n", err);
1750                 return;
1751         }
1752
1753         device->wakeup.flags.valid = 1;
1754         device->wakeup.prepare_count = 0;
1755         acpi_wakeup_gpe_init(device);
1756         /* Call _PSW/_DSW object to disable its ability to wake the sleeping
1757          * system for the ACPI device with the _PRW object.
1758          * The _PSW object is depreciated in ACPI 3.0 and is replaced by _DSW.
1759          * So it is necessary to call _DSW object first. Only when it is not
1760          * present will the _PSW object used.
1761          */
1762         err = acpi_device_sleep_wake(device, 0, 0, 0);
1763         if (err)
1764                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1765                                 "error in _DSW or _PSW evaluation\n"));
1766 }
1767
1768 static void acpi_bus_init_power_state(struct acpi_device *device, int state)
1769 {
1770         struct acpi_device_power_state *ps = &device->power.states[state];
1771         char pathname[5] = { '_', 'P', 'R', '0' + state, '\0' };
1772         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1773         acpi_status status;
1774
1775         INIT_LIST_HEAD(&ps->resources);
1776
1777         /* Evaluate "_PRx" to get referenced power resources */
1778         status = acpi_evaluate_object(device->handle, pathname, NULL, &buffer);
1779         if (ACPI_SUCCESS(status)) {
1780                 union acpi_object *package = buffer.pointer;
1781
1782                 if (buffer.length && package
1783                     && package->type == ACPI_TYPE_PACKAGE
1784                     && package->package.count) {
1785                         int err = acpi_extract_power_resources(package, 0,
1786                                                                &ps->resources);
1787                         if (!err)
1788                                 device->power.flags.power_resources = 1;
1789                 }
1790                 ACPI_FREE(buffer.pointer);
1791         }
1792
1793         /* Evaluate "_PSx" to see if we can do explicit sets */
1794         pathname[2] = 'S';
1795         if (acpi_has_method(device->handle, pathname))
1796                 ps->flags.explicit_set = 1;
1797
1798         /* State is valid if there are means to put the device into it. */
1799         if (!list_empty(&ps->resources) || ps->flags.explicit_set)
1800                 ps->flags.valid = 1;
1801
1802         ps->power = -1;         /* Unknown - driver assigned */
1803         ps->latency = -1;       /* Unknown - driver assigned */
1804 }
1805
1806 static void acpi_bus_get_power_flags(struct acpi_device *device)
1807 {
1808         u32 i;
1809
1810         /* Presence of _PS0|_PR0 indicates 'power manageable' */
1811         if (!acpi_has_method(device->handle, "_PS0") &&
1812             !acpi_has_method(device->handle, "_PR0"))
1813                 return;
1814
1815         device->flags.power_manageable = 1;
1816
1817         /*
1818          * Power Management Flags
1819          */
1820         if (acpi_has_method(device->handle, "_PSC"))
1821                 device->power.flags.explicit_get = 1;
1822
1823         if (acpi_has_method(device->handle, "_IRC"))
1824                 device->power.flags.inrush_current = 1;
1825
1826         if (acpi_has_method(device->handle, "_DSW"))
1827                 device->power.flags.dsw_present = 1;
1828
1829         /*
1830          * Enumerate supported power management states
1831          */
1832         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++)
1833                 acpi_bus_init_power_state(device, i);
1834
1835         INIT_LIST_HEAD(&device->power.states[ACPI_STATE_D3_COLD].resources);
1836         if (!list_empty(&device->power.states[ACPI_STATE_D3_HOT].resources))
1837                 device->power.states[ACPI_STATE_D3_COLD].flags.valid = 1;
1838
1839         /* Set defaults for D0 and D3hot states (always valid) */
1840         device->power.states[ACPI_STATE_D0].flags.valid = 1;
1841         device->power.states[ACPI_STATE_D0].power = 100;
1842         device->power.states[ACPI_STATE_D3_HOT].flags.valid = 1;
1843
1844         if (acpi_bus_init_power(device))
1845                 device->flags.power_manageable = 0;
1846 }
1847
1848 static void acpi_bus_get_flags(struct acpi_device *device)
1849 {
1850         /* Presence of _STA indicates 'dynamic_status' */
1851         if (acpi_has_method(device->handle, "_STA"))
1852                 device->flags.dynamic_status = 1;
1853
1854         /* Presence of _RMV indicates 'removable' */
1855         if (acpi_has_method(device->handle, "_RMV"))
1856                 device->flags.removable = 1;
1857
1858         /* Presence of _EJD|_EJ0 indicates 'ejectable' */
1859         if (acpi_has_method(device->handle, "_EJD") ||
1860             acpi_has_method(device->handle, "_EJ0"))
1861                 device->flags.ejectable = 1;
1862 }
1863
1864 static void acpi_device_get_busid(struct acpi_device *device)
1865 {
1866         char bus_id[5] = { '?', 0 };
1867         struct acpi_buffer buffer = { sizeof(bus_id), bus_id };
1868         int i = 0;
1869
1870         /*
1871          * Bus ID
1872          * ------
1873          * The device's Bus ID is simply the object name.
1874          * TBD: Shouldn't this value be unique (within the ACPI namespace)?
1875          */
1876         if (ACPI_IS_ROOT_DEVICE(device)) {
1877                 strcpy(device->pnp.bus_id, "ACPI");
1878                 return;
1879         }
1880
1881         switch (device->device_type) {
1882         case ACPI_BUS_TYPE_POWER_BUTTON:
1883                 strcpy(device->pnp.bus_id, "PWRF");
1884                 break;
1885         case ACPI_BUS_TYPE_SLEEP_BUTTON:
1886                 strcpy(device->pnp.bus_id, "SLPF");
1887                 break;
1888         default:
1889                 acpi_get_name(device->handle, ACPI_SINGLE_NAME, &buffer);
1890                 /* Clean up trailing underscores (if any) */
1891                 for (i = 3; i > 1; i--) {
1892                         if (bus_id[i] == '_')
1893                                 bus_id[i] = '\0';
1894                         else
1895                                 break;
1896                 }
1897                 strcpy(device->pnp.bus_id, bus_id);
1898                 break;
1899         }
1900 }
1901
1902 /*
1903  * acpi_ata_match - see if an acpi object is an ATA device
1904  *
1905  * If an acpi object has one of the ACPI ATA methods defined,
1906  * then we can safely call it an ATA device.
1907  */
1908 bool acpi_ata_match(acpi_handle handle)
1909 {
1910         return acpi_has_method(handle, "_GTF") ||
1911                acpi_has_method(handle, "_GTM") ||
1912                acpi_has_method(handle, "_STM") ||
1913                acpi_has_method(handle, "_SDD");
1914 }
1915
1916 /*
1917  * acpi_bay_match - see if an acpi object is an ejectable driver bay
1918  *
1919  * If an acpi object is ejectable and has one of the ACPI ATA methods defined,
1920  * then we can safely call it an ejectable drive bay
1921  */
1922 bool acpi_bay_match(acpi_handle handle)
1923 {
1924         acpi_handle phandle;
1925
1926         if (!acpi_has_method(handle, "_EJ0"))
1927                 return false;
1928         if (acpi_ata_match(handle))
1929                 return true;
1930         if (ACPI_FAILURE(acpi_get_parent(handle, &phandle)))
1931                 return false;
1932
1933         return acpi_ata_match(phandle);
1934 }
1935
1936 bool acpi_device_is_battery(struct acpi_device *adev)
1937 {
1938         struct acpi_hardware_id *hwid;
1939
1940         list_for_each_entry(hwid, &adev->pnp.ids, list)
1941                 if (!strcmp("PNP0C0A", hwid->id))
1942                         return true;
1943
1944         return false;
1945 }
1946
1947 static bool is_ejectable_bay(struct acpi_device *adev)
1948 {
1949         acpi_handle handle = adev->handle;
1950
1951         if (acpi_has_method(handle, "_EJ0") && acpi_device_is_battery(adev))
1952                 return true;
1953
1954         return acpi_bay_match(handle);
1955 }
1956
1957 /*
1958  * acpi_dock_match - see if an acpi object has a _DCK method
1959  */
1960 bool acpi_dock_match(acpi_handle handle)
1961 {
1962         return acpi_has_method(handle, "_DCK");
1963 }
1964
1965 static acpi_status
1966 acpi_backlight_cap_match(acpi_handle handle, u32 level, void *context,
1967                           void **return_value)
1968 {
1969         long *cap = context;
1970
1971         if (acpi_has_method(handle, "_BCM") &&
1972             acpi_has_method(handle, "_BCL")) {
1973                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found generic backlight "
1974                                   "support\n"));
1975                 *cap |= ACPI_VIDEO_BACKLIGHT;
1976                 if (!acpi_has_method(handle, "_BQC"))
1977                         printk(KERN_WARNING FW_BUG PREFIX "No _BQC method, "
1978                                 "cannot determine initial brightness\n");
1979                 /* We have backlight support, no need to scan further */
1980                 return AE_CTRL_TERMINATE;
1981         }
1982         return 0;
1983 }
1984
1985 /* Returns true if the ACPI object is a video device which can be
1986  * handled by video.ko.
1987  * The device will get a Linux specific CID added in scan.c to
1988  * identify the device as an ACPI graphics device
1989  * Be aware that the graphics device may not be physically present
1990  * Use acpi_video_get_capabilities() to detect general ACPI video
1991  * capabilities of present cards
1992  */
1993 long acpi_is_video_device(acpi_handle handle)
1994 {
1995         long video_caps = 0;
1996
1997         /* Is this device able to support video switching ? */
1998         if (acpi_has_method(handle, "_DOD") || acpi_has_method(handle, "_DOS"))
1999                 video_caps |= ACPI_VIDEO_OUTPUT_SWITCHING;
2000
2001         /* Is this device able to retrieve a video ROM ? */
2002         if (acpi_has_method(handle, "_ROM"))
2003                 video_caps |= ACPI_VIDEO_ROM_AVAILABLE;
2004
2005         /* Is this device able to configure which video head to be POSTed ? */
2006         if (acpi_has_method(handle, "_VPO") &&
2007             acpi_has_method(handle, "_GPD") &&
2008             acpi_has_method(handle, "_SPD"))
2009                 video_caps |= ACPI_VIDEO_DEVICE_POSTING;
2010
2011         /* Only check for backlight functionality if one of the above hit. */
2012         if (video_caps)
2013                 acpi_walk_namespace(ACPI_TYPE_DEVICE, handle,
2014                                     ACPI_UINT32_MAX, acpi_backlight_cap_match, NULL,
2015                                     &video_caps, NULL);
2016
2017         return video_caps;
2018 }
2019 EXPORT_SYMBOL(acpi_is_video_device);
2020
2021 const char *acpi_device_hid(struct acpi_device *device)
2022 {
2023         struct acpi_hardware_id *hid;
2024
2025         if (list_empty(&device->pnp.ids))
2026                 return dummy_hid;
2027
2028         hid = list_first_entry(&device->pnp.ids, struct acpi_hardware_id, list);
2029         return hid->id;
2030 }
2031 EXPORT_SYMBOL(acpi_device_hid);
2032
2033 static void acpi_add_id(struct acpi_device_pnp *pnp, const char *dev_id)
2034 {
2035         struct acpi_hardware_id *id;
2036
2037         id = kmalloc(sizeof(*id), GFP_KERNEL);
2038         if (!id)
2039                 return;
2040
2041         id->id = kstrdup(dev_id, GFP_KERNEL);
2042         if (!id->id) {
2043                 kfree(id);
2044                 return;
2045         }
2046
2047         list_add_tail(&id->list, &pnp->ids);
2048         pnp->type.hardware_id = 1;
2049 }
2050
2051 /*
2052  * Old IBM workstations have a DSDT bug wherein the SMBus object
2053  * lacks the SMBUS01 HID and the methods do not have the necessary "_"
2054  * prefix.  Work around this.
2055  */
2056 static bool acpi_ibm_smbus_match(acpi_handle handle)
2057 {
2058         char node_name[ACPI_PATH_SEGMENT_LENGTH];
2059         struct acpi_buffer path = { sizeof(node_name), node_name };
2060
2061         if (!dmi_name_in_vendors("IBM"))
2062                 return false;
2063
2064         /* Look for SMBS object */
2065         if (ACPI_FAILURE(acpi_get_name(handle, ACPI_SINGLE_NAME, &path)) ||
2066             strcmp("SMBS", path.pointer))
2067                 return false;
2068
2069         /* Does it have the necessary (but misnamed) methods? */
2070         if (acpi_has_method(handle, "SBI") &&
2071             acpi_has_method(handle, "SBR") &&
2072             acpi_has_method(handle, "SBW"))
2073                 return true;
2074
2075         return false;
2076 }
2077
2078 static bool acpi_object_is_system_bus(acpi_handle handle)
2079 {
2080         acpi_handle tmp;
2081
2082         if (ACPI_SUCCESS(acpi_get_handle(NULL, "\\_SB", &tmp)) &&
2083             tmp == handle)
2084                 return true;
2085         if (ACPI_SUCCESS(acpi_get_handle(NULL, "\\_TZ", &tmp)) &&
2086             tmp == handle)
2087                 return true;
2088
2089         return false;
2090 }
2091
2092 static void acpi_set_pnp_ids(acpi_handle handle, struct acpi_device_pnp *pnp,
2093                                 int device_type)
2094 {
2095         acpi_status status;
2096         struct acpi_device_info *info;
2097         struct acpi_pnp_device_id_list *cid_list;
2098         int i;
2099
2100         switch (device_type) {
2101         case ACPI_BUS_TYPE_DEVICE:
2102                 if (handle == ACPI_ROOT_OBJECT) {
2103                         acpi_add_id(pnp, ACPI_SYSTEM_HID);
2104                         break;
2105                 }
2106
2107                 status = acpi_get_object_info(handle, &info);
2108                 if (ACPI_FAILURE(status)) {
2109                         pr_err(PREFIX "%s: Error reading device info\n",
2110                                         __func__);
2111                         return;
2112                 }
2113
2114                 if (info->valid & ACPI_VALID_HID) {
2115                         acpi_add_id(pnp, info->hardware_id.string);
2116                         pnp->type.platform_id = 1;
2117                 }
2118                 if (info->valid & ACPI_VALID_CID) {
2119                         cid_list = &info->compatible_id_list;
2120                         for (i = 0; i < cid_list->count; i++)
2121                                 acpi_add_id(pnp, cid_list->ids[i].string);
2122                 }
2123                 if (info->valid & ACPI_VALID_ADR) {
2124                         pnp->bus_address = info->address;
2125                         pnp->type.bus_address = 1;
2126                 }
2127                 if (info->valid & ACPI_VALID_UID)
2128                         pnp->unique_id = kstrdup(info->unique_id.string,
2129                                                         GFP_KERNEL);
2130                 if (info->valid & ACPI_VALID_CLS)
2131                         acpi_add_id(pnp, info->class_code.string);
2132
2133                 kfree(info);
2134
2135                 /*
2136                  * Some devices don't reliably have _HIDs & _CIDs, so add
2137                  * synthetic HIDs to make sure drivers can find them.
2138                  */
2139                 if (acpi_is_video_device(handle))
2140                         acpi_add_id(pnp, ACPI_VIDEO_HID);
2141                 else if (acpi_bay_match(handle))
2142                         acpi_add_id(pnp, ACPI_BAY_HID);
2143                 else if (acpi_dock_match(handle))
2144                         acpi_add_id(pnp, ACPI_DOCK_HID);
2145                 else if (acpi_ibm_smbus_match(handle))
2146                         acpi_add_id(pnp, ACPI_SMBUS_IBM_HID);
2147                 else if (list_empty(&pnp->ids) &&
2148                          acpi_object_is_system_bus(handle)) {
2149                         /* \_SB, \_TZ, LNXSYBUS */
2150                         acpi_add_id(pnp, ACPI_BUS_HID);
2151                         strcpy(pnp->device_name, ACPI_BUS_DEVICE_NAME);
2152                         strcpy(pnp->device_class, ACPI_BUS_CLASS);
2153                 }
2154
2155                 break;
2156         case ACPI_BUS_TYPE_POWER:
2157                 acpi_add_id(pnp, ACPI_POWER_HID);
2158                 break;
2159         case ACPI_BUS_TYPE_PROCESSOR:
2160                 acpi_add_id(pnp, ACPI_PROCESSOR_OBJECT_HID);
2161                 break;
2162         case ACPI_BUS_TYPE_THERMAL:
2163                 acpi_add_id(pnp, ACPI_THERMAL_HID);
2164                 break;
2165         case ACPI_BUS_TYPE_POWER_BUTTON:
2166                 acpi_add_id(pnp, ACPI_BUTTON_HID_POWERF);
2167                 break;
2168         case ACPI_BUS_TYPE_SLEEP_BUTTON:
2169                 acpi_add_id(pnp, ACPI_BUTTON_HID_SLEEPF);
2170                 break;
2171         }
2172 }
2173
2174 void acpi_free_pnp_ids(struct acpi_device_pnp *pnp)
2175 {
2176         struct acpi_hardware_id *id, *tmp;
2177
2178         list_for_each_entry_safe(id, tmp, &pnp->ids, list) {
2179                 kfree(id->id);
2180                 kfree(id);
2181         }
2182         kfree(pnp->unique_id);
2183 }
2184
2185 static void acpi_init_coherency(struct acpi_device *adev)
2186 {
2187         unsigned long long cca = 0;
2188         acpi_status status;
2189         struct acpi_device *parent = adev->parent;
2190
2191         if (parent && parent->flags.cca_seen) {
2192                 /*
2193                  * From ACPI spec, OSPM will ignore _CCA if an ancestor
2194                  * already saw one.
2195                  */
2196                 adev->flags.cca_seen = 1;
2197                 cca = parent->flags.coherent_dma;
2198         } else {
2199                 status = acpi_evaluate_integer(adev->handle, "_CCA",
2200                                                NULL, &cca);
2201                 if (ACPI_SUCCESS(status))
2202                         adev->flags.cca_seen = 1;
2203                 else if (!IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED))
2204                         /*
2205                          * If architecture does not specify that _CCA is
2206                          * required for DMA-able devices (e.g. x86),
2207                          * we default to _CCA=1.
2208                          */
2209                         cca = 1;
2210                 else
2211                         acpi_handle_debug(adev->handle,
2212                                           "ACPI device is missing _CCA.\n");
2213         }
2214
2215         adev->flags.coherent_dma = cca;
2216 }
2217
2218 void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,
2219                              int type, unsigned long long sta)
2220 {
2221         INIT_LIST_HEAD(&device->pnp.ids);
2222         device->device_type = type;
2223         device->handle = handle;
2224         device->parent = acpi_bus_get_parent(handle);
2225         device->fwnode.type = FWNODE_ACPI;
2226         acpi_set_device_status(device, sta);
2227         acpi_device_get_busid(device);
2228         acpi_set_pnp_ids(handle, &device->pnp, type);
2229         acpi_init_properties(device);
2230         acpi_bus_get_flags(device);
2231         device->flags.match_driver = false;
2232         device->flags.initialized = true;
2233         device->flags.visited = false;
2234         device_initialize(&device->dev);
2235         dev_set_uevent_suppress(&device->dev, true);
2236         acpi_init_coherency(device);
2237 }
2238
2239 void acpi_device_add_finalize(struct acpi_device *device)
2240 {
2241         dev_set_uevent_suppress(&device->dev, false);
2242         kobject_uevent(&device->dev.kobj, KOBJ_ADD);
2243 }
2244
2245 static int acpi_add_single_object(struct acpi_device **child,
2246                                   acpi_handle handle, int type,
2247                                   unsigned long long sta)
2248 {
2249         int result;
2250         struct acpi_device *device;
2251         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
2252
2253         device = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
2254         if (!device) {
2255                 printk(KERN_ERR PREFIX "Memory allocation error\n");
2256                 return -ENOMEM;
2257         }
2258
2259         acpi_init_device_object(device, handle, type, sta);
2260         acpi_bus_get_power_flags(device);
2261         acpi_bus_get_wakeup_device_flags(device);
2262
2263         result = acpi_device_add(device, acpi_device_release);
2264         if (result) {
2265                 acpi_device_release(&device->dev);
2266                 return result;
2267         }
2268
2269         acpi_power_add_remove_device(device, true);
2270         acpi_device_add_finalize(device);
2271         acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
2272         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Added %s [%s] parent %s\n",
2273                 dev_name(&device->dev), (char *) buffer.pointer,
2274                 device->parent ? dev_name(&device->parent->dev) : "(null)"));
2275         kfree(buffer.pointer);
2276         *child = device;
2277         return 0;
2278 }
2279
2280 static int acpi_bus_type_and_status(acpi_handle handle, int *type,
2281                                     unsigned long long *sta)
2282 {
2283         acpi_status status;
2284         acpi_object_type acpi_type;
2285
2286         status = acpi_get_type(handle, &acpi_type);
2287         if (ACPI_FAILURE(status))
2288                 return -ENODEV;
2289
2290         switch (acpi_type) {
2291         case ACPI_TYPE_ANY:             /* for ACPI_ROOT_OBJECT */
2292         case ACPI_TYPE_DEVICE:
2293                 *type = ACPI_BUS_TYPE_DEVICE;
2294                 status = acpi_bus_get_status_handle(handle, sta);
2295                 if (ACPI_FAILURE(status))
2296                         return -ENODEV;
2297                 break;
2298         case ACPI_TYPE_PROCESSOR:
2299                 *type = ACPI_BUS_TYPE_PROCESSOR;
2300                 status = acpi_bus_get_status_handle(handle, sta);
2301                 if (ACPI_FAILURE(status))
2302                         return -ENODEV;
2303                 break;
2304         case ACPI_TYPE_THERMAL:
2305                 *type = ACPI_BUS_TYPE_THERMAL;
2306                 *sta = ACPI_STA_DEFAULT;
2307                 break;
2308         case ACPI_TYPE_POWER:
2309                 *type = ACPI_BUS_TYPE_POWER;
2310                 *sta = ACPI_STA_DEFAULT;
2311                 break;
2312         default:
2313                 return -ENODEV;
2314         }
2315
2316         return 0;
2317 }
2318
2319 bool acpi_device_is_present(struct acpi_device *adev)
2320 {
2321         if (adev->status.present || adev->status.functional)
2322                 return true;
2323
2324         adev->flags.initialized = false;
2325         return false;
2326 }
2327
2328 static bool acpi_scan_handler_matching(struct acpi_scan_handler *handler,
2329                                        char *idstr,
2330                                        const struct acpi_device_id **matchid)
2331 {
2332         const struct acpi_device_id *devid;
2333
2334         if (handler->match)
2335                 return handler->match(idstr, matchid);
2336
2337         for (devid = handler->ids; devid->id[0]; devid++)
2338                 if (!strcmp((char *)devid->id, idstr)) {
2339                         if (matchid)
2340                                 *matchid = devid;
2341
2342                         return true;
2343                 }
2344
2345         return false;
2346 }
2347
2348 static struct acpi_scan_handler *acpi_scan_match_handler(char *idstr,
2349                                         const struct acpi_device_id **matchid)
2350 {
2351         struct acpi_scan_handler *handler;
2352
2353         list_for_each_entry(handler, &acpi_scan_handlers_list, list_node)
2354                 if (acpi_scan_handler_matching(handler, idstr, matchid))
2355                         return handler;
2356
2357         return NULL;
2358 }
2359
2360 void acpi_scan_hotplug_enabled(struct acpi_hotplug_profile *hotplug, bool val)
2361 {
2362         if (!!hotplug->enabled == !!val)
2363                 return;
2364
2365         mutex_lock(&acpi_scan_lock);
2366
2367         hotplug->enabled = val;
2368
2369         mutex_unlock(&acpi_scan_lock);
2370 }
2371
2372 static void acpi_scan_init_hotplug(struct acpi_device *adev)
2373 {
2374         struct acpi_hardware_id *hwid;
2375
2376         if (acpi_dock_match(adev->handle) || is_ejectable_bay(adev)) {
2377                 acpi_dock_add(adev);
2378                 return;
2379         }
2380         list_for_each_entry(hwid, &adev->pnp.ids, list) {
2381                 struct acpi_scan_handler *handler;
2382
2383                 handler = acpi_scan_match_handler(hwid->id, NULL);
2384                 if (handler) {
2385                         adev->flags.hotplug_notify = true;
2386                         break;
2387                 }
2388         }
2389 }
2390
2391 static void acpi_device_dep_initialize(struct acpi_device *adev)
2392 {
2393         struct acpi_dep_data *dep;
2394         struct acpi_handle_list dep_devices;
2395         acpi_status status;
2396         int i;
2397
2398         if (!acpi_has_method(adev->handle, "_DEP"))
2399                 return;
2400
2401         status = acpi_evaluate_reference(adev->handle, "_DEP", NULL,
2402                                         &dep_devices);
2403         if (ACPI_FAILURE(status)) {
2404                 dev_dbg(&adev->dev, "Failed to evaluate _DEP.\n");
2405                 return;
2406         }
2407
2408         for (i = 0; i < dep_devices.count; i++) {
2409                 struct acpi_device_info *info;
2410                 int skip;
2411
2412                 status = acpi_get_object_info(dep_devices.handles[i], &info);
2413                 if (ACPI_FAILURE(status)) {
2414                         dev_dbg(&adev->dev, "Error reading _DEP device info\n");
2415                         continue;
2416                 }
2417
2418                 /*
2419                  * Skip the dependency of Windows System Power
2420                  * Management Controller
2421                  */
2422                 skip = info->valid & ACPI_VALID_HID &&
2423                         !strcmp(info->hardware_id.string, "INT3396");
2424
2425                 kfree(info);
2426
2427                 if (skip)
2428                         continue;
2429
2430                 dep = kzalloc(sizeof(struct acpi_dep_data), GFP_KERNEL);
2431                 if (!dep)
2432                         return;
2433
2434                 dep->master = dep_devices.handles[i];
2435                 dep->slave  = adev->handle;
2436                 adev->dep_unmet++;
2437
2438                 mutex_lock(&acpi_dep_list_lock);
2439                 list_add_tail(&dep->node , &acpi_dep_list);
2440                 mutex_unlock(&acpi_dep_list_lock);
2441         }
2442 }
2443
2444 static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl_not_used,
2445                                       void *not_used, void **return_value)
2446 {
2447         struct acpi_device *device = NULL;
2448         int type;
2449         unsigned long long sta;
2450         int result;
2451
2452         acpi_bus_get_device(handle, &device);
2453         if (device)
2454                 goto out;
2455
2456         result = acpi_bus_type_and_status(handle, &type, &sta);
2457         if (result)
2458                 return AE_OK;
2459
2460         if (type == ACPI_BUS_TYPE_POWER) {
2461                 acpi_add_power_resource(handle);
2462                 return AE_OK;
2463         }
2464
2465         acpi_add_single_object(&device, handle, type, sta);
2466         if (!device)
2467                 return AE_CTRL_DEPTH;
2468
2469         acpi_scan_init_hotplug(device);
2470         acpi_device_dep_initialize(device);
2471
2472  out:
2473         if (!*return_value)
2474                 *return_value = device;
2475
2476         return AE_OK;
2477 }
2478
2479 static int acpi_check_spi_i2c_slave(struct acpi_resource *ares, void *data)
2480 {
2481         bool *is_spi_i2c_slave_p = data;
2482
2483         if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
2484                 return 1;
2485
2486         /*
2487          * devices that are connected to UART still need to be enumerated to
2488          * platform bus
2489          */
2490         if (ares->data.common_serial_bus.type != ACPI_RESOURCE_SERIAL_TYPE_UART)
2491                 *is_spi_i2c_slave_p = true;
2492
2493          /* no need to do more checking */
2494         return -1;
2495 }
2496
2497 static void acpi_default_enumeration(struct acpi_device *device)
2498 {
2499         struct list_head resource_list;
2500         bool is_spi_i2c_slave = false;
2501
2502         /*
2503          * Do not enemerate SPI/I2C slaves as they will be enuerated by their
2504          * respective parents.
2505          */
2506         INIT_LIST_HEAD(&resource_list);
2507         acpi_dev_get_resources(device, &resource_list, acpi_check_spi_i2c_slave,
2508                                &is_spi_i2c_slave);
2509         acpi_dev_free_resource_list(&resource_list);
2510         if (!is_spi_i2c_slave)
2511                 acpi_create_platform_device(device);
2512 }
2513
2514 static const struct acpi_device_id generic_device_ids[] = {
2515         {ACPI_DT_NAMESPACE_HID, },
2516         {"", },
2517 };
2518
2519 static int acpi_generic_device_attach(struct acpi_device *adev,
2520                                       const struct acpi_device_id *not_used)
2521 {
2522         /*
2523          * Since ACPI_DT_NAMESPACE_HID is the only ID handled here, the test
2524          * below can be unconditional.
2525          */
2526         if (adev->data.of_compatible)
2527                 acpi_default_enumeration(adev);
2528
2529         return 1;
2530 }
2531
2532 static struct acpi_scan_handler generic_device_handler = {
2533         .ids = generic_device_ids,
2534         .attach = acpi_generic_device_attach,
2535 };
2536
2537 static int acpi_scan_attach_handler(struct acpi_device *device)
2538 {
2539         struct acpi_hardware_id *hwid;
2540         int ret = 0;
2541
2542         list_for_each_entry(hwid, &device->pnp.ids, list) {
2543                 const struct acpi_device_id *devid;
2544                 struct acpi_scan_handler *handler;
2545
2546                 handler = acpi_scan_match_handler(hwid->id, &devid);
2547                 if (handler) {
2548                         if (!handler->attach) {
2549                                 device->pnp.type.platform_id = 0;
2550                                 continue;
2551                         }
2552                         device->handler = handler;
2553                         ret = handler->attach(device, devid);
2554                         if (ret > 0)
2555                                 break;
2556
2557                         device->handler = NULL;
2558                         if (ret < 0)
2559                                 break;
2560                 }
2561         }
2562
2563         return ret;
2564 }
2565
2566 static void acpi_bus_attach(struct acpi_device *device)
2567 {
2568         struct acpi_device *child;
2569         acpi_handle ejd;
2570         int ret;
2571
2572         if (ACPI_SUCCESS(acpi_bus_get_ejd(device->handle, &ejd)))
2573                 register_dock_dependent_device(device, ejd);
2574
2575         acpi_bus_get_status(device);
2576         /* Skip devices that are not present. */
2577         if (!acpi_device_is_present(device)) {
2578                 device->flags.visited = false;
2579                 device->flags.power_manageable = 0;
2580                 return;
2581         }
2582         if (device->handler)
2583                 goto ok;
2584
2585         if (!device->flags.initialized) {
2586                 device->flags.power_manageable =
2587                         device->power.states[ACPI_STATE_D0].flags.valid;
2588                 if (acpi_bus_init_power(device))
2589                         device->flags.power_manageable = 0;
2590
2591                 device->flags.initialized = true;
2592         }
2593         device->flags.visited = false;
2594         ret = acpi_scan_attach_handler(device);
2595         if (ret < 0)
2596                 return;
2597
2598         device->flags.match_driver = true;
2599         if (!ret) {
2600                 ret = device_attach(&device->dev);
2601                 if (ret < 0)
2602                         return;
2603
2604                 if (!ret && device->pnp.type.platform_id)
2605                         acpi_default_enumeration(device);
2606         }
2607         device->flags.visited = true;
2608
2609  ok:
2610         list_for_each_entry(child, &device->children, node)
2611                 acpi_bus_attach(child);
2612
2613         if (device->handler && device->handler->hotplug.notify_online)
2614                 device->handler->hotplug.notify_online(device);
2615 }
2616
2617 void acpi_walk_dep_device_list(acpi_handle handle)
2618 {
2619         struct acpi_dep_data *dep, *tmp;
2620         struct acpi_device *adev;
2621
2622         mutex_lock(&acpi_dep_list_lock);
2623         list_for_each_entry_safe(dep, tmp, &acpi_dep_list, node) {
2624                 if (dep->master == handle) {
2625                         acpi_bus_get_device(dep->slave, &adev);
2626                         if (!adev)
2627                                 continue;
2628
2629                         adev->dep_unmet--;
2630                         if (!adev->dep_unmet)
2631                                 acpi_bus_attach(adev);
2632                         list_del(&dep->node);
2633                         kfree(dep);
2634                 }
2635         }
2636         mutex_unlock(&acpi_dep_list_lock);
2637 }
2638 EXPORT_SYMBOL_GPL(acpi_walk_dep_device_list);
2639
2640 /**
2641  * acpi_bus_scan - Add ACPI device node objects in a given namespace scope.
2642  * @handle: Root of the namespace scope to scan.
2643  *
2644  * Scan a given ACPI tree (probably recently hot-plugged) and create and add
2645  * found devices.
2646  *
2647  * If no devices were found, -ENODEV is returned, but it does not mean that
2648  * there has been a real error.  There just have been no suitable ACPI objects
2649  * in the table trunk from which the kernel could create a device and add an
2650  * appropriate driver.
2651  *
2652  * Must be called under acpi_scan_lock.
2653  */
2654 int acpi_bus_scan(acpi_handle handle)
2655 {
2656         void *device = NULL;
2657
2658         if (ACPI_SUCCESS(acpi_bus_check_add(handle, 0, NULL, &device)))
2659                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
2660                                     acpi_bus_check_add, NULL, NULL, &device);
2661
2662         if (device) {
2663                 acpi_bus_attach(device);
2664                 return 0;
2665         }
2666         return -ENODEV;
2667 }
2668 EXPORT_SYMBOL(acpi_bus_scan);
2669
2670 /**
2671  * acpi_bus_trim - Detach scan handlers and drivers from ACPI device objects.
2672  * @adev: Root of the ACPI namespace scope to walk.
2673  *
2674  * Must be called under acpi_scan_lock.
2675  */
2676 void acpi_bus_trim(struct acpi_device *adev)
2677 {
2678         struct acpi_scan_handler *handler = adev->handler;
2679         struct acpi_device *child;
2680
2681         list_for_each_entry_reverse(child, &adev->children, node)
2682                 acpi_bus_trim(child);
2683
2684         adev->flags.match_driver = false;
2685         if (handler) {
2686                 if (handler->detach)
2687                         handler->detach(adev);
2688
2689                 adev->handler = NULL;
2690         } else {
2691                 device_release_driver(&adev->dev);
2692         }
2693         /*
2694          * Most likely, the device is going away, so put it into D3cold before
2695          * that.
2696          */
2697         acpi_device_set_power(adev, ACPI_STATE_D3_COLD);
2698         adev->flags.initialized = false;
2699         adev->flags.visited = false;
2700 }
2701 EXPORT_SYMBOL_GPL(acpi_bus_trim);
2702
2703 static int acpi_bus_scan_fixed(void)
2704 {
2705         int result = 0;
2706
2707         /*
2708          * Enumerate all fixed-feature devices.
2709          */
2710         if (!(acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON)) {
2711                 struct acpi_device *device = NULL;
2712
2713                 result = acpi_add_single_object(&device, NULL,
2714                                                 ACPI_BUS_TYPE_POWER_BUTTON,
2715                                                 ACPI_STA_DEFAULT);
2716                 if (result)
2717                         return result;
2718
2719                 device->flags.match_driver = true;
2720                 result = device_attach(&device->dev);
2721                 if (result < 0)
2722                         return result;
2723
2724                 device_init_wakeup(&device->dev, true);
2725         }
2726
2727         if (!(acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON)) {
2728                 struct acpi_device *device = NULL;
2729
2730                 result = acpi_add_single_object(&device, NULL,
2731                                                 ACPI_BUS_TYPE_SLEEP_BUTTON,
2732                                                 ACPI_STA_DEFAULT);
2733                 if (result)
2734                         return result;
2735
2736                 device->flags.match_driver = true;
2737                 result = device_attach(&device->dev);
2738         }
2739
2740         return result < 0 ? result : 0;
2741 }
2742
2743 int __init acpi_scan_init(void)
2744 {
2745         int result;
2746
2747         result = bus_register(&acpi_bus_type);
2748         if (result) {
2749                 /* We don't want to quit even if we failed to add suspend/resume */
2750                 printk(KERN_ERR PREFIX "Could not register bus type\n");
2751         }
2752
2753         acpi_pci_root_init();
2754         acpi_pci_link_init();
2755         acpi_processor_init();
2756         acpi_lpss_init();
2757         acpi_apd_init();
2758         acpi_cmos_rtc_init();
2759         acpi_container_init();
2760         acpi_memory_hotplug_init();
2761         acpi_pnp_init();
2762         acpi_int340x_thermal_init();
2763
2764         acpi_scan_add_handler(&generic_device_handler);
2765
2766         mutex_lock(&acpi_scan_lock);
2767         /*
2768          * Enumerate devices in the ACPI namespace.
2769          */
2770         result = acpi_bus_scan(ACPI_ROOT_OBJECT);
2771         if (result)
2772                 goto out;
2773
2774         result = acpi_bus_get_device(ACPI_ROOT_OBJECT, &acpi_root);
2775         if (result)
2776                 goto out;
2777
2778         /* Fixed feature devices do not exist on HW-reduced platform */
2779         if (!acpi_gbl_reduced_hardware) {
2780                 result = acpi_bus_scan_fixed();
2781                 if (result) {
2782                         acpi_detach_data(acpi_root->handle,
2783                                          acpi_scan_drop_device);
2784                         acpi_device_del(acpi_root);
2785                         put_device(&acpi_root->dev);
2786                         goto out;
2787                 }
2788         }
2789
2790         acpi_update_all_gpes();
2791
2792  out:
2793         mutex_unlock(&acpi_scan_lock);
2794         return result;
2795 }