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 const struct acpi_device_id *__acpi_match_device(
1023         struct acpi_device *device,
1024         const struct acpi_device_id *ids,
1025         const struct of_device_id *of_ids)
1026 {
1027         const struct acpi_device_id *id;
1028         struct acpi_hardware_id *hwid;
1029
1030         /*
1031          * If the device is not present, it is unnecessary to load device
1032          * driver for it.
1033          */
1034         if (!device || !device->status.present)
1035                 return NULL;
1036
1037         list_for_each_entry(hwid, &device->pnp.ids, list) {
1038                 /* First, check the ACPI/PNP IDs provided by the caller. */
1039                 for (id = ids; id->id[0]; id++)
1040                         if (!strcmp((char *) id->id, hwid->id))
1041                                 return id;
1042
1043                 /*
1044                  * Next, check ACPI_DT_NAMESPACE_HID and try to match the
1045                  * "compatible" property if found.
1046                  *
1047                  * The id returned by the below is not valid, but the only
1048                  * caller passing non-NULL of_ids here is only interested in
1049                  * whether or not the return value is NULL.
1050                  */
1051                 if (!strcmp(ACPI_DT_NAMESPACE_HID, hwid->id)
1052                     && acpi_of_match_device(device, of_ids))
1053                         return id;
1054         }
1055         return NULL;
1056 }
1057
1058 /**
1059  * acpi_match_device - Match a struct device against a given list of ACPI IDs
1060  * @ids: Array of struct acpi_device_id object to match against.
1061  * @dev: The device structure to match.
1062  *
1063  * Check if @dev has a valid ACPI handle and if there is a struct acpi_device
1064  * object for that handle and use that object to match against a given list of
1065  * device IDs.
1066  *
1067  * Return a pointer to the first matching ID on success or %NULL on failure.
1068  */
1069 const struct acpi_device_id *acpi_match_device(const struct acpi_device_id *ids,
1070                                                const struct device *dev)
1071 {
1072         return __acpi_match_device(acpi_companion_match(dev), ids, NULL);
1073 }
1074 EXPORT_SYMBOL_GPL(acpi_match_device);
1075
1076 int acpi_match_device_ids(struct acpi_device *device,
1077                           const struct acpi_device_id *ids)
1078 {
1079         return __acpi_match_device(device, ids, NULL) ? 0 : -ENOENT;
1080 }
1081 EXPORT_SYMBOL(acpi_match_device_ids);
1082
1083 bool acpi_driver_match_device(struct device *dev,
1084                               const struct device_driver *drv)
1085 {
1086         if (!drv->acpi_match_table)
1087                 return acpi_of_match_device(ACPI_COMPANION(dev),
1088                                             drv->of_match_table);
1089
1090         return !!__acpi_match_device(acpi_companion_match(dev),
1091                                      drv->acpi_match_table, drv->of_match_table);
1092 }
1093 EXPORT_SYMBOL_GPL(acpi_driver_match_device);
1094
1095 static void acpi_free_power_resources_lists(struct acpi_device *device)
1096 {
1097         int i;
1098
1099         if (device->wakeup.flags.valid)
1100                 acpi_power_resources_list_free(&device->wakeup.resources);
1101
1102         if (!device->power.flags.power_resources)
1103                 return;
1104
1105         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
1106                 struct acpi_device_power_state *ps = &device->power.states[i];
1107                 acpi_power_resources_list_free(&ps->resources);
1108         }
1109 }
1110
1111 static void acpi_device_release(struct device *dev)
1112 {
1113         struct acpi_device *acpi_dev = to_acpi_device(dev);
1114
1115         acpi_free_properties(acpi_dev);
1116         acpi_free_pnp_ids(&acpi_dev->pnp);
1117         acpi_free_power_resources_lists(acpi_dev);
1118         kfree(acpi_dev);
1119 }
1120
1121 static int acpi_bus_match(struct device *dev, struct device_driver *drv)
1122 {
1123         struct acpi_device *acpi_dev = to_acpi_device(dev);
1124         struct acpi_driver *acpi_drv = to_acpi_driver(drv);
1125
1126         return acpi_dev->flags.match_driver
1127                 && !acpi_match_device_ids(acpi_dev, acpi_drv->ids);
1128 }
1129
1130 static int acpi_device_uevent(struct device *dev, struct kobj_uevent_env *env)
1131 {
1132         return __acpi_device_uevent_modalias(to_acpi_device(dev), env);
1133 }
1134
1135 static void acpi_device_notify(acpi_handle handle, u32 event, void *data)
1136 {
1137         struct acpi_device *device = data;
1138
1139         device->driver->ops.notify(device, event);
1140 }
1141
1142 static void acpi_device_notify_fixed(void *data)
1143 {
1144         struct acpi_device *device = data;
1145
1146         /* Fixed hardware devices have no handles */
1147         acpi_device_notify(NULL, ACPI_FIXED_HARDWARE_EVENT, device);
1148 }
1149
1150 static u32 acpi_device_fixed_event(void *data)
1151 {
1152         acpi_os_execute(OSL_NOTIFY_HANDLER, acpi_device_notify_fixed, data);
1153         return ACPI_INTERRUPT_HANDLED;
1154 }
1155
1156 static int acpi_device_install_notify_handler(struct acpi_device *device)
1157 {
1158         acpi_status status;
1159
1160         if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
1161                 status =
1162                     acpi_install_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
1163                                                      acpi_device_fixed_event,
1164                                                      device);
1165         else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
1166                 status =
1167                     acpi_install_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
1168                                                      acpi_device_fixed_event,
1169                                                      device);
1170         else
1171                 status = acpi_install_notify_handler(device->handle,
1172                                                      ACPI_DEVICE_NOTIFY,
1173                                                      acpi_device_notify,
1174                                                      device);
1175
1176         if (ACPI_FAILURE(status))
1177                 return -EINVAL;
1178         return 0;
1179 }
1180
1181 static void acpi_device_remove_notify_handler(struct acpi_device *device)
1182 {
1183         if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
1184                 acpi_remove_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
1185                                                 acpi_device_fixed_event);
1186         else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
1187                 acpi_remove_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
1188                                                 acpi_device_fixed_event);
1189         else
1190                 acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
1191                                            acpi_device_notify);
1192 }
1193
1194 static int acpi_device_probe(struct device *dev)
1195 {
1196         struct acpi_device *acpi_dev = to_acpi_device(dev);
1197         struct acpi_driver *acpi_drv = to_acpi_driver(dev->driver);
1198         int ret;
1199
1200         if (acpi_dev->handler && !acpi_is_pnp_device(acpi_dev))
1201                 return -EINVAL;
1202
1203         if (!acpi_drv->ops.add)
1204                 return -ENOSYS;
1205
1206         ret = acpi_drv->ops.add(acpi_dev);
1207         if (ret)
1208                 return ret;
1209
1210         acpi_dev->driver = acpi_drv;
1211         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1212                           "Driver [%s] successfully bound to device [%s]\n",
1213                           acpi_drv->name, acpi_dev->pnp.bus_id));
1214
1215         if (acpi_drv->ops.notify) {
1216                 ret = acpi_device_install_notify_handler(acpi_dev);
1217                 if (ret) {
1218                         if (acpi_drv->ops.remove)
1219                                 acpi_drv->ops.remove(acpi_dev);
1220
1221                         acpi_dev->driver = NULL;
1222                         acpi_dev->driver_data = NULL;
1223                         return ret;
1224                 }
1225         }
1226
1227         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found driver [%s] for device [%s]\n",
1228                           acpi_drv->name, acpi_dev->pnp.bus_id));
1229         get_device(dev);
1230         return 0;
1231 }
1232
1233 static int acpi_device_remove(struct device * dev)
1234 {
1235         struct acpi_device *acpi_dev = to_acpi_device(dev);
1236         struct acpi_driver *acpi_drv = acpi_dev->driver;
1237
1238         if (acpi_drv) {
1239                 if (acpi_drv->ops.notify)
1240                         acpi_device_remove_notify_handler(acpi_dev);
1241                 if (acpi_drv->ops.remove)
1242                         acpi_drv->ops.remove(acpi_dev);
1243         }
1244         acpi_dev->driver = NULL;
1245         acpi_dev->driver_data = NULL;
1246
1247         put_device(dev);
1248         return 0;
1249 }
1250
1251 struct bus_type acpi_bus_type = {
1252         .name           = "acpi",
1253         .match          = acpi_bus_match,
1254         .probe          = acpi_device_probe,
1255         .remove         = acpi_device_remove,
1256         .uevent         = acpi_device_uevent,
1257 };
1258
1259 static void acpi_device_del(struct acpi_device *device)
1260 {
1261         mutex_lock(&acpi_device_lock);
1262         if (device->parent)
1263                 list_del(&device->node);
1264
1265         list_del(&device->wakeup_list);
1266         mutex_unlock(&acpi_device_lock);
1267
1268         acpi_power_add_remove_device(device, false);
1269         acpi_device_remove_files(device);
1270         if (device->remove)
1271                 device->remove(device);
1272
1273         device_del(&device->dev);
1274 }
1275
1276 static LIST_HEAD(acpi_device_del_list);
1277 static DEFINE_MUTEX(acpi_device_del_lock);
1278
1279 static void acpi_device_del_work_fn(struct work_struct *work_not_used)
1280 {
1281         for (;;) {
1282                 struct acpi_device *adev;
1283
1284                 mutex_lock(&acpi_device_del_lock);
1285
1286                 if (list_empty(&acpi_device_del_list)) {
1287                         mutex_unlock(&acpi_device_del_lock);
1288                         break;
1289                 }
1290                 adev = list_first_entry(&acpi_device_del_list,
1291                                         struct acpi_device, del_list);
1292                 list_del(&adev->del_list);
1293
1294                 mutex_unlock(&acpi_device_del_lock);
1295
1296                 acpi_device_del(adev);
1297                 /*
1298                  * Drop references to all power resources that might have been
1299                  * used by the device.
1300                  */
1301                 acpi_power_transition(adev, ACPI_STATE_D3_COLD);
1302                 put_device(&adev->dev);
1303         }
1304 }
1305
1306 /**
1307  * acpi_scan_drop_device - Drop an ACPI device object.
1308  * @handle: Handle of an ACPI namespace node, not used.
1309  * @context: Address of the ACPI device object to drop.
1310  *
1311  * This is invoked by acpi_ns_delete_node() during the removal of the ACPI
1312  * namespace node the device object pointed to by @context is attached to.
1313  *
1314  * The unregistration is carried out asynchronously to avoid running
1315  * acpi_device_del() under the ACPICA's namespace mutex and the list is used to
1316  * ensure the correct ordering (the device objects must be unregistered in the
1317  * same order in which the corresponding namespace nodes are deleted).
1318  */
1319 static void acpi_scan_drop_device(acpi_handle handle, void *context)
1320 {
1321         static DECLARE_WORK(work, acpi_device_del_work_fn);
1322         struct acpi_device *adev = context;
1323
1324         mutex_lock(&acpi_device_del_lock);
1325
1326         /*
1327          * Use the ACPI hotplug workqueue which is ordered, so this work item
1328          * won't run after any hotplug work items submitted subsequently.  That
1329          * prevents attempts to register device objects identical to those being
1330          * deleted from happening concurrently (such attempts result from
1331          * hotplug events handled via the ACPI hotplug workqueue).  It also will
1332          * run after all of the work items submitted previosuly, which helps
1333          * those work items to ensure that they are not accessing stale device
1334          * objects.
1335          */
1336         if (list_empty(&acpi_device_del_list))
1337                 acpi_queue_hotplug_work(&work);
1338
1339         list_add_tail(&adev->del_list, &acpi_device_del_list);
1340         /* Make acpi_ns_validate_handle() return NULL for this handle. */
1341         adev->handle = INVALID_ACPI_HANDLE;
1342
1343         mutex_unlock(&acpi_device_del_lock);
1344 }
1345
1346 static int acpi_get_device_data(acpi_handle handle, struct acpi_device **device,
1347                                 void (*callback)(void *))
1348 {
1349         acpi_status status;
1350
1351         if (!device)
1352                 return -EINVAL;
1353
1354         status = acpi_get_data_full(handle, acpi_scan_drop_device,
1355                                     (void **)device, callback);
1356         if (ACPI_FAILURE(status) || !*device) {
1357                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No context for object [%p]\n",
1358                                   handle));
1359                 return -ENODEV;
1360         }
1361         return 0;
1362 }
1363
1364 int acpi_bus_get_device(acpi_handle handle, struct acpi_device **device)
1365 {
1366         return acpi_get_device_data(handle, device, NULL);
1367 }
1368 EXPORT_SYMBOL(acpi_bus_get_device);
1369
1370 static void get_acpi_device(void *dev)
1371 {
1372         if (dev)
1373                 get_device(&((struct acpi_device *)dev)->dev);
1374 }
1375
1376 struct acpi_device *acpi_bus_get_acpi_device(acpi_handle handle)
1377 {
1378         struct acpi_device *adev = NULL;
1379
1380         acpi_get_device_data(handle, &adev, get_acpi_device);
1381         return adev;
1382 }
1383
1384 void acpi_bus_put_acpi_device(struct acpi_device *adev)
1385 {
1386         put_device(&adev->dev);
1387 }
1388
1389 int acpi_device_add(struct acpi_device *device,
1390                     void (*release)(struct device *))
1391 {
1392         int result;
1393         struct acpi_device_bus_id *acpi_device_bus_id, *new_bus_id;
1394         int found = 0;
1395
1396         if (device->handle) {
1397                 acpi_status status;
1398
1399                 status = acpi_attach_data(device->handle, acpi_scan_drop_device,
1400                                           device);
1401                 if (ACPI_FAILURE(status)) {
1402                         acpi_handle_err(device->handle,
1403                                         "Unable to attach device data\n");
1404                         return -ENODEV;
1405                 }
1406         }
1407
1408         /*
1409          * Linkage
1410          * -------
1411          * Link this device to its parent and siblings.
1412          */
1413         INIT_LIST_HEAD(&device->children);
1414         INIT_LIST_HEAD(&device->node);
1415         INIT_LIST_HEAD(&device->wakeup_list);
1416         INIT_LIST_HEAD(&device->physical_node_list);
1417         INIT_LIST_HEAD(&device->del_list);
1418         mutex_init(&device->physical_node_lock);
1419
1420         new_bus_id = kzalloc(sizeof(struct acpi_device_bus_id), GFP_KERNEL);
1421         if (!new_bus_id) {
1422                 pr_err(PREFIX "Memory allocation error\n");
1423                 result = -ENOMEM;
1424                 goto err_detach;
1425         }
1426
1427         mutex_lock(&acpi_device_lock);
1428         /*
1429          * Find suitable bus_id and instance number in acpi_bus_id_list
1430          * If failed, create one and link it into acpi_bus_id_list
1431          */
1432         list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
1433                 if (!strcmp(acpi_device_bus_id->bus_id,
1434                             acpi_device_hid(device))) {
1435                         acpi_device_bus_id->instance_no++;
1436                         found = 1;
1437                         kfree(new_bus_id);
1438                         break;
1439                 }
1440         }
1441         if (!found) {
1442                 acpi_device_bus_id = new_bus_id;
1443                 strcpy(acpi_device_bus_id->bus_id, acpi_device_hid(device));
1444                 acpi_device_bus_id->instance_no = 0;
1445                 list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
1446         }
1447         dev_set_name(&device->dev, "%s:%02x", acpi_device_bus_id->bus_id, acpi_device_bus_id->instance_no);
1448
1449         if (device->parent)
1450                 list_add_tail(&device->node, &device->parent->children);
1451
1452         if (device->wakeup.flags.valid)
1453                 list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);
1454         mutex_unlock(&acpi_device_lock);
1455
1456         if (device->parent)
1457                 device->dev.parent = &device->parent->dev;
1458         device->dev.bus = &acpi_bus_type;
1459         device->dev.release = release;
1460         result = device_add(&device->dev);
1461         if (result) {
1462                 dev_err(&device->dev, "Error registering device\n");
1463                 goto err;
1464         }
1465
1466         result = acpi_device_setup_files(device);
1467         if (result)
1468                 printk(KERN_ERR PREFIX "Error creating sysfs interface for device %s\n",
1469                        dev_name(&device->dev));
1470
1471         return 0;
1472
1473  err:
1474         mutex_lock(&acpi_device_lock);
1475         if (device->parent)
1476                 list_del(&device->node);
1477         list_del(&device->wakeup_list);
1478         mutex_unlock(&acpi_device_lock);
1479
1480  err_detach:
1481         acpi_detach_data(device->handle, acpi_scan_drop_device);
1482         return result;
1483 }
1484
1485 struct acpi_device *acpi_get_next_child(struct device *dev,
1486                                         struct acpi_device *child)
1487 {
1488         struct acpi_device *adev = ACPI_COMPANION(dev);
1489         struct list_head *head, *next;
1490
1491         if (!adev)
1492                 return NULL;
1493
1494         head = &adev->children;
1495         if (list_empty(head))
1496                 return NULL;
1497
1498         if (!child)
1499                 return list_first_entry(head, struct acpi_device, node);
1500
1501         next = child->node.next;
1502         return next == head ? NULL : list_entry(next, struct acpi_device, node);
1503 }
1504
1505 /* --------------------------------------------------------------------------
1506                                  Driver Management
1507    -------------------------------------------------------------------------- */
1508 /**
1509  * acpi_bus_register_driver - register a driver with the ACPI bus
1510  * @driver: driver being registered
1511  *
1512  * Registers a driver with the ACPI bus.  Searches the namespace for all
1513  * devices that match the driver's criteria and binds.  Returns zero for
1514  * success or a negative error status for failure.
1515  */
1516 int acpi_bus_register_driver(struct acpi_driver *driver)
1517 {
1518         int ret;
1519
1520         if (acpi_disabled)
1521                 return -ENODEV;
1522         driver->drv.name = driver->name;
1523         driver->drv.bus = &acpi_bus_type;
1524         driver->drv.owner = driver->owner;
1525
1526         ret = driver_register(&driver->drv);
1527         return ret;
1528 }
1529
1530 EXPORT_SYMBOL(acpi_bus_register_driver);
1531
1532 /**
1533  * acpi_bus_unregister_driver - unregisters a driver with the ACPI bus
1534  * @driver: driver to unregister
1535  *
1536  * Unregisters a driver with the ACPI bus.  Searches the namespace for all
1537  * devices that match the driver's criteria and unbinds.
1538  */
1539 void acpi_bus_unregister_driver(struct acpi_driver *driver)
1540 {
1541         driver_unregister(&driver->drv);
1542 }
1543
1544 EXPORT_SYMBOL(acpi_bus_unregister_driver);
1545
1546 /* --------------------------------------------------------------------------
1547                                  Device Enumeration
1548    -------------------------------------------------------------------------- */
1549 static struct acpi_device *acpi_bus_get_parent(acpi_handle handle)
1550 {
1551         struct acpi_device *device = NULL;
1552         acpi_status status;
1553
1554         /*
1555          * Fixed hardware devices do not appear in the namespace and do not
1556          * have handles, but we fabricate acpi_devices for them, so we have
1557          * to deal with them specially.
1558          */
1559         if (!handle)
1560                 return acpi_root;
1561
1562         do {
1563                 status = acpi_get_parent(handle, &handle);
1564                 if (ACPI_FAILURE(status))
1565                         return status == AE_NULL_ENTRY ? NULL : acpi_root;
1566         } while (acpi_bus_get_device(handle, &device));
1567         return device;
1568 }
1569
1570 acpi_status
1571 acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
1572 {
1573         acpi_status status;
1574         acpi_handle tmp;
1575         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
1576         union acpi_object *obj;
1577
1578         status = acpi_get_handle(handle, "_EJD", &tmp);
1579         if (ACPI_FAILURE(status))
1580                 return status;
1581
1582         status = acpi_evaluate_object(handle, "_EJD", NULL, &buffer);
1583         if (ACPI_SUCCESS(status)) {
1584                 obj = buffer.pointer;
1585                 status = acpi_get_handle(ACPI_ROOT_OBJECT, obj->string.pointer,
1586                                          ejd);
1587                 kfree(buffer.pointer);
1588         }
1589         return status;
1590 }
1591 EXPORT_SYMBOL_GPL(acpi_bus_get_ejd);
1592
1593 static int acpi_bus_extract_wakeup_device_power_package(acpi_handle handle,
1594                                         struct acpi_device_wakeup *wakeup)
1595 {
1596         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1597         union acpi_object *package = NULL;
1598         union acpi_object *element = NULL;
1599         acpi_status status;
1600         int err = -ENODATA;
1601
1602         if (!wakeup)
1603                 return -EINVAL;
1604
1605         INIT_LIST_HEAD(&wakeup->resources);
1606
1607         /* _PRW */
1608         status = acpi_evaluate_object(handle, "_PRW", NULL, &buffer);
1609         if (ACPI_FAILURE(status)) {
1610                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRW"));
1611                 return err;
1612         }
1613
1614         package = (union acpi_object *)buffer.pointer;
1615
1616         if (!package || package->package.count < 2)
1617                 goto out;
1618
1619         element = &(package->package.elements[0]);
1620         if (!element)
1621                 goto out;
1622
1623         if (element->type == ACPI_TYPE_PACKAGE) {
1624                 if ((element->package.count < 2) ||
1625                     (element->package.elements[0].type !=
1626                      ACPI_TYPE_LOCAL_REFERENCE)
1627                     || (element->package.elements[1].type != ACPI_TYPE_INTEGER))
1628                         goto out;
1629
1630                 wakeup->gpe_device =
1631                     element->package.elements[0].reference.handle;
1632                 wakeup->gpe_number =
1633                     (u32) element->package.elements[1].integer.value;
1634         } else if (element->type == ACPI_TYPE_INTEGER) {
1635                 wakeup->gpe_device = NULL;
1636                 wakeup->gpe_number = element->integer.value;
1637         } else {
1638                 goto out;
1639         }
1640
1641         element = &(package->package.elements[1]);
1642         if (element->type != ACPI_TYPE_INTEGER)
1643                 goto out;
1644
1645         wakeup->sleep_state = element->integer.value;
1646
1647         err = acpi_extract_power_resources(package, 2, &wakeup->resources);
1648         if (err)
1649                 goto out;
1650
1651         if (!list_empty(&wakeup->resources)) {
1652                 int sleep_state;
1653
1654                 err = acpi_power_wakeup_list_init(&wakeup->resources,
1655                                                   &sleep_state);
1656                 if (err) {
1657                         acpi_handle_warn(handle, "Retrieving current states "
1658                                          "of wakeup power resources failed\n");
1659                         acpi_power_resources_list_free(&wakeup->resources);
1660                         goto out;
1661                 }
1662                 if (sleep_state < wakeup->sleep_state) {
1663                         acpi_handle_warn(handle, "Overriding _PRW sleep state "
1664                                          "(S%d) by S%d from power resources\n",
1665                                          (int)wakeup->sleep_state, sleep_state);
1666                         wakeup->sleep_state = sleep_state;
1667                 }
1668         }
1669
1670  out:
1671         kfree(buffer.pointer);
1672         return err;
1673 }
1674
1675 static void acpi_wakeup_gpe_init(struct acpi_device *device)
1676 {
1677         static const struct acpi_device_id button_device_ids[] = {
1678                 {"PNP0C0C", 0},
1679                 {"PNP0C0D", 0},
1680                 {"PNP0C0E", 0},
1681                 {"", 0},
1682         };
1683         struct acpi_device_wakeup *wakeup = &device->wakeup;
1684         acpi_status status;
1685         acpi_event_status event_status;
1686
1687         wakeup->flags.notifier_present = 0;
1688
1689         /* Power button, Lid switch always enable wakeup */
1690         if (!acpi_match_device_ids(device, button_device_ids)) {
1691                 wakeup->flags.run_wake = 1;
1692                 if (!acpi_match_device_ids(device, &button_device_ids[1])) {
1693                         /* Do not use Lid/sleep button for S5 wakeup */
1694                         if (wakeup->sleep_state == ACPI_STATE_S5)
1695                                 wakeup->sleep_state = ACPI_STATE_S4;
1696                 }
1697                 acpi_mark_gpe_for_wake(wakeup->gpe_device, wakeup->gpe_number);
1698                 device_set_wakeup_capable(&device->dev, true);
1699                 return;
1700         }
1701
1702         acpi_setup_gpe_for_wake(device->handle, wakeup->gpe_device,
1703                                 wakeup->gpe_number);
1704         status = acpi_get_gpe_status(wakeup->gpe_device, wakeup->gpe_number,
1705                                      &event_status);
1706         if (ACPI_FAILURE(status))
1707                 return;
1708
1709         wakeup->flags.run_wake = !!(event_status & ACPI_EVENT_FLAG_HAS_HANDLER);
1710 }
1711
1712 static void acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
1713 {
1714         int err;
1715
1716         /* Presence of _PRW indicates wake capable */
1717         if (!acpi_has_method(device->handle, "_PRW"))
1718                 return;
1719
1720         err = acpi_bus_extract_wakeup_device_power_package(device->handle,
1721                                                            &device->wakeup);
1722         if (err) {
1723                 dev_err(&device->dev, "_PRW evaluation error: %d\n", err);
1724                 return;
1725         }
1726
1727         device->wakeup.flags.valid = 1;
1728         device->wakeup.prepare_count = 0;
1729         acpi_wakeup_gpe_init(device);
1730         /* Call _PSW/_DSW object to disable its ability to wake the sleeping
1731          * system for the ACPI device with the _PRW object.
1732          * The _PSW object is depreciated in ACPI 3.0 and is replaced by _DSW.
1733          * So it is necessary to call _DSW object first. Only when it is not
1734          * present will the _PSW object used.
1735          */
1736         err = acpi_device_sleep_wake(device, 0, 0, 0);
1737         if (err)
1738                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1739                                 "error in _DSW or _PSW evaluation\n"));
1740 }
1741
1742 static void acpi_bus_init_power_state(struct acpi_device *device, int state)
1743 {
1744         struct acpi_device_power_state *ps = &device->power.states[state];
1745         char pathname[5] = { '_', 'P', 'R', '0' + state, '\0' };
1746         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1747         acpi_status status;
1748
1749         INIT_LIST_HEAD(&ps->resources);
1750
1751         /* Evaluate "_PRx" to get referenced power resources */
1752         status = acpi_evaluate_object(device->handle, pathname, NULL, &buffer);
1753         if (ACPI_SUCCESS(status)) {
1754                 union acpi_object *package = buffer.pointer;
1755
1756                 if (buffer.length && package
1757                     && package->type == ACPI_TYPE_PACKAGE
1758                     && package->package.count) {
1759                         int err = acpi_extract_power_resources(package, 0,
1760                                                                &ps->resources);
1761                         if (!err)
1762                                 device->power.flags.power_resources = 1;
1763                 }
1764                 ACPI_FREE(buffer.pointer);
1765         }
1766
1767         /* Evaluate "_PSx" to see if we can do explicit sets */
1768         pathname[2] = 'S';
1769         if (acpi_has_method(device->handle, pathname))
1770                 ps->flags.explicit_set = 1;
1771
1772         /* State is valid if there are means to put the device into it. */
1773         if (!list_empty(&ps->resources) || ps->flags.explicit_set)
1774                 ps->flags.valid = 1;
1775
1776         ps->power = -1;         /* Unknown - driver assigned */
1777         ps->latency = -1;       /* Unknown - driver assigned */
1778 }
1779
1780 static void acpi_bus_get_power_flags(struct acpi_device *device)
1781 {
1782         u32 i;
1783
1784         /* Presence of _PS0|_PR0 indicates 'power manageable' */
1785         if (!acpi_has_method(device->handle, "_PS0") &&
1786             !acpi_has_method(device->handle, "_PR0"))
1787                 return;
1788
1789         device->flags.power_manageable = 1;
1790
1791         /*
1792          * Power Management Flags
1793          */
1794         if (acpi_has_method(device->handle, "_PSC"))
1795                 device->power.flags.explicit_get = 1;
1796
1797         if (acpi_has_method(device->handle, "_IRC"))
1798                 device->power.flags.inrush_current = 1;
1799
1800         if (acpi_has_method(device->handle, "_DSW"))
1801                 device->power.flags.dsw_present = 1;
1802
1803         /*
1804          * Enumerate supported power management states
1805          */
1806         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++)
1807                 acpi_bus_init_power_state(device, i);
1808
1809         INIT_LIST_HEAD(&device->power.states[ACPI_STATE_D3_COLD].resources);
1810         if (!list_empty(&device->power.states[ACPI_STATE_D3_HOT].resources))
1811                 device->power.states[ACPI_STATE_D3_COLD].flags.valid = 1;
1812
1813         /* Set defaults for D0 and D3hot states (always valid) */
1814         device->power.states[ACPI_STATE_D0].flags.valid = 1;
1815         device->power.states[ACPI_STATE_D0].power = 100;
1816         device->power.states[ACPI_STATE_D3_HOT].flags.valid = 1;
1817
1818         if (acpi_bus_init_power(device))
1819                 device->flags.power_manageable = 0;
1820 }
1821
1822 static void acpi_bus_get_flags(struct acpi_device *device)
1823 {
1824         /* Presence of _STA indicates 'dynamic_status' */
1825         if (acpi_has_method(device->handle, "_STA"))
1826                 device->flags.dynamic_status = 1;
1827
1828         /* Presence of _RMV indicates 'removable' */
1829         if (acpi_has_method(device->handle, "_RMV"))
1830                 device->flags.removable = 1;
1831
1832         /* Presence of _EJD|_EJ0 indicates 'ejectable' */
1833         if (acpi_has_method(device->handle, "_EJD") ||
1834             acpi_has_method(device->handle, "_EJ0"))
1835                 device->flags.ejectable = 1;
1836 }
1837
1838 static void acpi_device_get_busid(struct acpi_device *device)
1839 {
1840         char bus_id[5] = { '?', 0 };
1841         struct acpi_buffer buffer = { sizeof(bus_id), bus_id };
1842         int i = 0;
1843
1844         /*
1845          * Bus ID
1846          * ------
1847          * The device's Bus ID is simply the object name.
1848          * TBD: Shouldn't this value be unique (within the ACPI namespace)?
1849          */
1850         if (ACPI_IS_ROOT_DEVICE(device)) {
1851                 strcpy(device->pnp.bus_id, "ACPI");
1852                 return;
1853         }
1854
1855         switch (device->device_type) {
1856         case ACPI_BUS_TYPE_POWER_BUTTON:
1857                 strcpy(device->pnp.bus_id, "PWRF");
1858                 break;
1859         case ACPI_BUS_TYPE_SLEEP_BUTTON:
1860                 strcpy(device->pnp.bus_id, "SLPF");
1861                 break;
1862         default:
1863                 acpi_get_name(device->handle, ACPI_SINGLE_NAME, &buffer);
1864                 /* Clean up trailing underscores (if any) */
1865                 for (i = 3; i > 1; i--) {
1866                         if (bus_id[i] == '_')
1867                                 bus_id[i] = '\0';
1868                         else
1869                                 break;
1870                 }
1871                 strcpy(device->pnp.bus_id, bus_id);
1872                 break;
1873         }
1874 }
1875
1876 /*
1877  * acpi_ata_match - see if an acpi object is an ATA device
1878  *
1879  * If an acpi object has one of the ACPI ATA methods defined,
1880  * then we can safely call it an ATA device.
1881  */
1882 bool acpi_ata_match(acpi_handle handle)
1883 {
1884         return acpi_has_method(handle, "_GTF") ||
1885                acpi_has_method(handle, "_GTM") ||
1886                acpi_has_method(handle, "_STM") ||
1887                acpi_has_method(handle, "_SDD");
1888 }
1889
1890 /*
1891  * acpi_bay_match - see if an acpi object is an ejectable driver bay
1892  *
1893  * If an acpi object is ejectable and has one of the ACPI ATA methods defined,
1894  * then we can safely call it an ejectable drive bay
1895  */
1896 bool acpi_bay_match(acpi_handle handle)
1897 {
1898         acpi_handle phandle;
1899
1900         if (!acpi_has_method(handle, "_EJ0"))
1901                 return false;
1902         if (acpi_ata_match(handle))
1903                 return true;
1904         if (ACPI_FAILURE(acpi_get_parent(handle, &phandle)))
1905                 return false;
1906
1907         return acpi_ata_match(phandle);
1908 }
1909
1910 bool acpi_device_is_battery(struct acpi_device *adev)
1911 {
1912         struct acpi_hardware_id *hwid;
1913
1914         list_for_each_entry(hwid, &adev->pnp.ids, list)
1915                 if (!strcmp("PNP0C0A", hwid->id))
1916                         return true;
1917
1918         return false;
1919 }
1920
1921 static bool is_ejectable_bay(struct acpi_device *adev)
1922 {
1923         acpi_handle handle = adev->handle;
1924
1925         if (acpi_has_method(handle, "_EJ0") && acpi_device_is_battery(adev))
1926                 return true;
1927
1928         return acpi_bay_match(handle);
1929 }
1930
1931 /*
1932  * acpi_dock_match - see if an acpi object has a _DCK method
1933  */
1934 bool acpi_dock_match(acpi_handle handle)
1935 {
1936         return acpi_has_method(handle, "_DCK");
1937 }
1938
1939 static acpi_status
1940 acpi_backlight_cap_match(acpi_handle handle, u32 level, void *context,
1941                           void **return_value)
1942 {
1943         long *cap = context;
1944
1945         if (acpi_has_method(handle, "_BCM") &&
1946             acpi_has_method(handle, "_BCL")) {
1947                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found generic backlight "
1948                                   "support\n"));
1949                 *cap |= ACPI_VIDEO_BACKLIGHT;
1950                 if (!acpi_has_method(handle, "_BQC"))
1951                         printk(KERN_WARNING FW_BUG PREFIX "No _BQC method, "
1952                                 "cannot determine initial brightness\n");
1953                 /* We have backlight support, no need to scan further */
1954                 return AE_CTRL_TERMINATE;
1955         }
1956         return 0;
1957 }
1958
1959 /* Returns true if the ACPI object is a video device which can be
1960  * handled by video.ko.
1961  * The device will get a Linux specific CID added in scan.c to
1962  * identify the device as an ACPI graphics device
1963  * Be aware that the graphics device may not be physically present
1964  * Use acpi_video_get_capabilities() to detect general ACPI video
1965  * capabilities of present cards
1966  */
1967 long acpi_is_video_device(acpi_handle handle)
1968 {
1969         long video_caps = 0;
1970
1971         /* Is this device able to support video switching ? */
1972         if (acpi_has_method(handle, "_DOD") || acpi_has_method(handle, "_DOS"))
1973                 video_caps |= ACPI_VIDEO_OUTPUT_SWITCHING;
1974
1975         /* Is this device able to retrieve a video ROM ? */
1976         if (acpi_has_method(handle, "_ROM"))
1977                 video_caps |= ACPI_VIDEO_ROM_AVAILABLE;
1978
1979         /* Is this device able to configure which video head to be POSTed ? */
1980         if (acpi_has_method(handle, "_VPO") &&
1981             acpi_has_method(handle, "_GPD") &&
1982             acpi_has_method(handle, "_SPD"))
1983                 video_caps |= ACPI_VIDEO_DEVICE_POSTING;
1984
1985         /* Only check for backlight functionality if one of the above hit. */
1986         if (video_caps)
1987                 acpi_walk_namespace(ACPI_TYPE_DEVICE, handle,
1988                                     ACPI_UINT32_MAX, acpi_backlight_cap_match, NULL,
1989                                     &video_caps, NULL);
1990
1991         return video_caps;
1992 }
1993 EXPORT_SYMBOL(acpi_is_video_device);
1994
1995 const char *acpi_device_hid(struct acpi_device *device)
1996 {
1997         struct acpi_hardware_id *hid;
1998
1999         if (list_empty(&device->pnp.ids))
2000                 return dummy_hid;
2001
2002         hid = list_first_entry(&device->pnp.ids, struct acpi_hardware_id, list);
2003         return hid->id;
2004 }
2005 EXPORT_SYMBOL(acpi_device_hid);
2006
2007 static void acpi_add_id(struct acpi_device_pnp *pnp, const char *dev_id)
2008 {
2009         struct acpi_hardware_id *id;
2010
2011         id = kmalloc(sizeof(*id), GFP_KERNEL);
2012         if (!id)
2013                 return;
2014
2015         id->id = kstrdup(dev_id, GFP_KERNEL);
2016         if (!id->id) {
2017                 kfree(id);
2018                 return;
2019         }
2020
2021         list_add_tail(&id->list, &pnp->ids);
2022         pnp->type.hardware_id = 1;
2023 }
2024
2025 /*
2026  * Old IBM workstations have a DSDT bug wherein the SMBus object
2027  * lacks the SMBUS01 HID and the methods do not have the necessary "_"
2028  * prefix.  Work around this.
2029  */
2030 static bool acpi_ibm_smbus_match(acpi_handle handle)
2031 {
2032         char node_name[ACPI_PATH_SEGMENT_LENGTH];
2033         struct acpi_buffer path = { sizeof(node_name), node_name };
2034
2035         if (!dmi_name_in_vendors("IBM"))
2036                 return false;
2037
2038         /* Look for SMBS object */
2039         if (ACPI_FAILURE(acpi_get_name(handle, ACPI_SINGLE_NAME, &path)) ||
2040             strcmp("SMBS", path.pointer))
2041                 return false;
2042
2043         /* Does it have the necessary (but misnamed) methods? */
2044         if (acpi_has_method(handle, "SBI") &&
2045             acpi_has_method(handle, "SBR") &&
2046             acpi_has_method(handle, "SBW"))
2047                 return true;
2048
2049         return false;
2050 }
2051
2052 static bool acpi_object_is_system_bus(acpi_handle handle)
2053 {
2054         acpi_handle tmp;
2055
2056         if (ACPI_SUCCESS(acpi_get_handle(NULL, "\\_SB", &tmp)) &&
2057             tmp == handle)
2058                 return true;
2059         if (ACPI_SUCCESS(acpi_get_handle(NULL, "\\_TZ", &tmp)) &&
2060             tmp == handle)
2061                 return true;
2062
2063         return false;
2064 }
2065
2066 static void acpi_set_pnp_ids(acpi_handle handle, struct acpi_device_pnp *pnp,
2067                                 int device_type)
2068 {
2069         acpi_status status;
2070         struct acpi_device_info *info;
2071         struct acpi_pnp_device_id_list *cid_list;
2072         int i;
2073
2074         switch (device_type) {
2075         case ACPI_BUS_TYPE_DEVICE:
2076                 if (handle == ACPI_ROOT_OBJECT) {
2077                         acpi_add_id(pnp, ACPI_SYSTEM_HID);
2078                         break;
2079                 }
2080
2081                 status = acpi_get_object_info(handle, &info);
2082                 if (ACPI_FAILURE(status)) {
2083                         pr_err(PREFIX "%s: Error reading device info\n",
2084                                         __func__);
2085                         return;
2086                 }
2087
2088                 if (info->valid & ACPI_VALID_HID) {
2089                         acpi_add_id(pnp, info->hardware_id.string);
2090                         pnp->type.platform_id = 1;
2091                 }
2092                 if (info->valid & ACPI_VALID_CID) {
2093                         cid_list = &info->compatible_id_list;
2094                         for (i = 0; i < cid_list->count; i++)
2095                                 acpi_add_id(pnp, cid_list->ids[i].string);
2096                 }
2097                 if (info->valid & ACPI_VALID_ADR) {
2098                         pnp->bus_address = info->address;
2099                         pnp->type.bus_address = 1;
2100                 }
2101                 if (info->valid & ACPI_VALID_UID)
2102                         pnp->unique_id = kstrdup(info->unique_id.string,
2103                                                         GFP_KERNEL);
2104
2105                 kfree(info);
2106
2107                 /*
2108                  * Some devices don't reliably have _HIDs & _CIDs, so add
2109                  * synthetic HIDs to make sure drivers can find them.
2110                  */
2111                 if (acpi_is_video_device(handle))
2112                         acpi_add_id(pnp, ACPI_VIDEO_HID);
2113                 else if (acpi_bay_match(handle))
2114                         acpi_add_id(pnp, ACPI_BAY_HID);
2115                 else if (acpi_dock_match(handle))
2116                         acpi_add_id(pnp, ACPI_DOCK_HID);
2117                 else if (acpi_ibm_smbus_match(handle))
2118                         acpi_add_id(pnp, ACPI_SMBUS_IBM_HID);
2119                 else if (list_empty(&pnp->ids) &&
2120                          acpi_object_is_system_bus(handle)) {
2121                         /* \_SB, \_TZ, LNXSYBUS */
2122                         acpi_add_id(pnp, ACPI_BUS_HID);
2123                         strcpy(pnp->device_name, ACPI_BUS_DEVICE_NAME);
2124                         strcpy(pnp->device_class, ACPI_BUS_CLASS);
2125                 }
2126
2127                 break;
2128         case ACPI_BUS_TYPE_POWER:
2129                 acpi_add_id(pnp, ACPI_POWER_HID);
2130                 break;
2131         case ACPI_BUS_TYPE_PROCESSOR:
2132                 acpi_add_id(pnp, ACPI_PROCESSOR_OBJECT_HID);
2133                 break;
2134         case ACPI_BUS_TYPE_THERMAL:
2135                 acpi_add_id(pnp, ACPI_THERMAL_HID);
2136                 break;
2137         case ACPI_BUS_TYPE_POWER_BUTTON:
2138                 acpi_add_id(pnp, ACPI_BUTTON_HID_POWERF);
2139                 break;
2140         case ACPI_BUS_TYPE_SLEEP_BUTTON:
2141                 acpi_add_id(pnp, ACPI_BUTTON_HID_SLEEPF);
2142                 break;
2143         }
2144 }
2145
2146 void acpi_free_pnp_ids(struct acpi_device_pnp *pnp)
2147 {
2148         struct acpi_hardware_id *id, *tmp;
2149
2150         list_for_each_entry_safe(id, tmp, &pnp->ids, list) {
2151                 kfree(id->id);
2152                 kfree(id);
2153         }
2154         kfree(pnp->unique_id);
2155 }
2156
2157 static void acpi_init_coherency(struct acpi_device *adev)
2158 {
2159         unsigned long long cca = 0;
2160         acpi_status status;
2161         struct acpi_device *parent = adev->parent;
2162
2163         if (parent && parent->flags.cca_seen) {
2164                 /*
2165                  * From ACPI spec, OSPM will ignore _CCA if an ancestor
2166                  * already saw one.
2167                  */
2168                 adev->flags.cca_seen = 1;
2169                 cca = parent->flags.coherent_dma;
2170         } else {
2171                 status = acpi_evaluate_integer(adev->handle, "_CCA",
2172                                                NULL, &cca);
2173                 if (ACPI_SUCCESS(status))
2174                         adev->flags.cca_seen = 1;
2175                 else if (!IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED))
2176                         /*
2177                          * If architecture does not specify that _CCA is
2178                          * required for DMA-able devices (e.g. x86),
2179                          * we default to _CCA=1.
2180                          */
2181                         cca = 1;
2182                 else
2183                         acpi_handle_debug(adev->handle,
2184                                           "ACPI device is missing _CCA.\n");
2185         }
2186
2187         adev->flags.coherent_dma = cca;
2188 }
2189
2190 void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,
2191                              int type, unsigned long long sta)
2192 {
2193         INIT_LIST_HEAD(&device->pnp.ids);
2194         device->device_type = type;
2195         device->handle = handle;
2196         device->parent = acpi_bus_get_parent(handle);
2197         device->fwnode.type = FWNODE_ACPI;
2198         acpi_set_device_status(device, sta);
2199         acpi_device_get_busid(device);
2200         acpi_set_pnp_ids(handle, &device->pnp, type);
2201         acpi_init_properties(device);
2202         acpi_bus_get_flags(device);
2203         device->flags.match_driver = false;
2204         device->flags.initialized = true;
2205         device->flags.visited = false;
2206         device_initialize(&device->dev);
2207         dev_set_uevent_suppress(&device->dev, true);
2208         acpi_init_coherency(device);
2209 }
2210
2211 void acpi_device_add_finalize(struct acpi_device *device)
2212 {
2213         dev_set_uevent_suppress(&device->dev, false);
2214         kobject_uevent(&device->dev.kobj, KOBJ_ADD);
2215 }
2216
2217 static int acpi_add_single_object(struct acpi_device **child,
2218                                   acpi_handle handle, int type,
2219                                   unsigned long long sta)
2220 {
2221         int result;
2222         struct acpi_device *device;
2223         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
2224
2225         device = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
2226         if (!device) {
2227                 printk(KERN_ERR PREFIX "Memory allocation error\n");
2228                 return -ENOMEM;
2229         }
2230
2231         acpi_init_device_object(device, handle, type, sta);
2232         acpi_bus_get_power_flags(device);
2233         acpi_bus_get_wakeup_device_flags(device);
2234
2235         result = acpi_device_add(device, acpi_device_release);
2236         if (result) {
2237                 acpi_device_release(&device->dev);
2238                 return result;
2239         }
2240
2241         acpi_power_add_remove_device(device, true);
2242         acpi_device_add_finalize(device);
2243         acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
2244         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Added %s [%s] parent %s\n",
2245                 dev_name(&device->dev), (char *) buffer.pointer,
2246                 device->parent ? dev_name(&device->parent->dev) : "(null)"));
2247         kfree(buffer.pointer);
2248         *child = device;
2249         return 0;
2250 }
2251
2252 static int acpi_bus_type_and_status(acpi_handle handle, int *type,
2253                                     unsigned long long *sta)
2254 {
2255         acpi_status status;
2256         acpi_object_type acpi_type;
2257
2258         status = acpi_get_type(handle, &acpi_type);
2259         if (ACPI_FAILURE(status))
2260                 return -ENODEV;
2261
2262         switch (acpi_type) {
2263         case ACPI_TYPE_ANY:             /* for ACPI_ROOT_OBJECT */
2264         case ACPI_TYPE_DEVICE:
2265                 *type = ACPI_BUS_TYPE_DEVICE;
2266                 status = acpi_bus_get_status_handle(handle, sta);
2267                 if (ACPI_FAILURE(status))
2268                         return -ENODEV;
2269                 break;
2270         case ACPI_TYPE_PROCESSOR:
2271                 *type = ACPI_BUS_TYPE_PROCESSOR;
2272                 status = acpi_bus_get_status_handle(handle, sta);
2273                 if (ACPI_FAILURE(status))
2274                         return -ENODEV;
2275                 break;
2276         case ACPI_TYPE_THERMAL:
2277                 *type = ACPI_BUS_TYPE_THERMAL;
2278                 *sta = ACPI_STA_DEFAULT;
2279                 break;
2280         case ACPI_TYPE_POWER:
2281                 *type = ACPI_BUS_TYPE_POWER;
2282                 *sta = ACPI_STA_DEFAULT;
2283                 break;
2284         default:
2285                 return -ENODEV;
2286         }
2287
2288         return 0;
2289 }
2290
2291 bool acpi_device_is_present(struct acpi_device *adev)
2292 {
2293         if (adev->status.present || adev->status.functional)
2294                 return true;
2295
2296         adev->flags.initialized = false;
2297         return false;
2298 }
2299
2300 static bool acpi_scan_handler_matching(struct acpi_scan_handler *handler,
2301                                        char *idstr,
2302                                        const struct acpi_device_id **matchid)
2303 {
2304         const struct acpi_device_id *devid;
2305
2306         if (handler->match)
2307                 return handler->match(idstr, matchid);
2308
2309         for (devid = handler->ids; devid->id[0]; devid++)
2310                 if (!strcmp((char *)devid->id, idstr)) {
2311                         if (matchid)
2312                                 *matchid = devid;
2313
2314                         return true;
2315                 }
2316
2317         return false;
2318 }
2319
2320 static struct acpi_scan_handler *acpi_scan_match_handler(char *idstr,
2321                                         const struct acpi_device_id **matchid)
2322 {
2323         struct acpi_scan_handler *handler;
2324
2325         list_for_each_entry(handler, &acpi_scan_handlers_list, list_node)
2326                 if (acpi_scan_handler_matching(handler, idstr, matchid))
2327                         return handler;
2328
2329         return NULL;
2330 }
2331
2332 void acpi_scan_hotplug_enabled(struct acpi_hotplug_profile *hotplug, bool val)
2333 {
2334         if (!!hotplug->enabled == !!val)
2335                 return;
2336
2337         mutex_lock(&acpi_scan_lock);
2338
2339         hotplug->enabled = val;
2340
2341         mutex_unlock(&acpi_scan_lock);
2342 }
2343
2344 static void acpi_scan_init_hotplug(struct acpi_device *adev)
2345 {
2346         struct acpi_hardware_id *hwid;
2347
2348         if (acpi_dock_match(adev->handle) || is_ejectable_bay(adev)) {
2349                 acpi_dock_add(adev);
2350                 return;
2351         }
2352         list_for_each_entry(hwid, &adev->pnp.ids, list) {
2353                 struct acpi_scan_handler *handler;
2354
2355                 handler = acpi_scan_match_handler(hwid->id, NULL);
2356                 if (handler) {
2357                         adev->flags.hotplug_notify = true;
2358                         break;
2359                 }
2360         }
2361 }
2362
2363 static void acpi_device_dep_initialize(struct acpi_device *adev)
2364 {
2365         struct acpi_dep_data *dep;
2366         struct acpi_handle_list dep_devices;
2367         acpi_status status;
2368         int i;
2369
2370         if (!acpi_has_method(adev->handle, "_DEP"))
2371                 return;
2372
2373         status = acpi_evaluate_reference(adev->handle, "_DEP", NULL,
2374                                         &dep_devices);
2375         if (ACPI_FAILURE(status)) {
2376                 dev_dbg(&adev->dev, "Failed to evaluate _DEP.\n");
2377                 return;
2378         }
2379
2380         for (i = 0; i < dep_devices.count; i++) {
2381                 struct acpi_device_info *info;
2382                 int skip;
2383
2384                 status = acpi_get_object_info(dep_devices.handles[i], &info);
2385                 if (ACPI_FAILURE(status)) {
2386                         dev_dbg(&adev->dev, "Error reading _DEP device info\n");
2387                         continue;
2388                 }
2389
2390                 /*
2391                  * Skip the dependency of Windows System Power
2392                  * Management Controller
2393                  */
2394                 skip = info->valid & ACPI_VALID_HID &&
2395                         !strcmp(info->hardware_id.string, "INT3396");
2396
2397                 kfree(info);
2398
2399                 if (skip)
2400                         continue;
2401
2402                 dep = kzalloc(sizeof(struct acpi_dep_data), GFP_KERNEL);
2403                 if (!dep)
2404                         return;
2405
2406                 dep->master = dep_devices.handles[i];
2407                 dep->slave  = adev->handle;
2408                 adev->dep_unmet++;
2409
2410                 mutex_lock(&acpi_dep_list_lock);
2411                 list_add_tail(&dep->node , &acpi_dep_list);
2412                 mutex_unlock(&acpi_dep_list_lock);
2413         }
2414 }
2415
2416 static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl_not_used,
2417                                       void *not_used, void **return_value)
2418 {
2419         struct acpi_device *device = NULL;
2420         int type;
2421         unsigned long long sta;
2422         int result;
2423
2424         acpi_bus_get_device(handle, &device);
2425         if (device)
2426                 goto out;
2427
2428         result = acpi_bus_type_and_status(handle, &type, &sta);
2429         if (result)
2430                 return AE_OK;
2431
2432         if (type == ACPI_BUS_TYPE_POWER) {
2433                 acpi_add_power_resource(handle);
2434                 return AE_OK;
2435         }
2436
2437         acpi_add_single_object(&device, handle, type, sta);
2438         if (!device)
2439                 return AE_CTRL_DEPTH;
2440
2441         acpi_scan_init_hotplug(device);
2442         acpi_device_dep_initialize(device);
2443
2444  out:
2445         if (!*return_value)
2446                 *return_value = device;
2447
2448         return AE_OK;
2449 }
2450
2451 static int acpi_check_spi_i2c_slave(struct acpi_resource *ares, void *data)
2452 {
2453         bool *is_spi_i2c_slave_p = data;
2454
2455         if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
2456                 return 1;
2457
2458         /*
2459          * devices that are connected to UART still need to be enumerated to
2460          * platform bus
2461          */
2462         if (ares->data.common_serial_bus.type != ACPI_RESOURCE_SERIAL_TYPE_UART)
2463                 *is_spi_i2c_slave_p = true;
2464
2465          /* no need to do more checking */
2466         return -1;
2467 }
2468
2469 static void acpi_default_enumeration(struct acpi_device *device)
2470 {
2471         struct list_head resource_list;
2472         bool is_spi_i2c_slave = false;
2473
2474         /*
2475          * Do not enemerate SPI/I2C slaves as they will be enuerated by their
2476          * respective parents.
2477          */
2478         INIT_LIST_HEAD(&resource_list);
2479         acpi_dev_get_resources(device, &resource_list, acpi_check_spi_i2c_slave,
2480                                &is_spi_i2c_slave);
2481         acpi_dev_free_resource_list(&resource_list);
2482         if (!is_spi_i2c_slave)
2483                 acpi_create_platform_device(device);
2484 }
2485
2486 static const struct acpi_device_id generic_device_ids[] = {
2487         {ACPI_DT_NAMESPACE_HID, },
2488         {"", },
2489 };
2490
2491 static int acpi_generic_device_attach(struct acpi_device *adev,
2492                                       const struct acpi_device_id *not_used)
2493 {
2494         /*
2495          * Since ACPI_DT_NAMESPACE_HID is the only ID handled here, the test
2496          * below can be unconditional.
2497          */
2498         if (adev->data.of_compatible)
2499                 acpi_default_enumeration(adev);
2500
2501         return 1;
2502 }
2503
2504 static struct acpi_scan_handler generic_device_handler = {
2505         .ids = generic_device_ids,
2506         .attach = acpi_generic_device_attach,
2507 };
2508
2509 static int acpi_scan_attach_handler(struct acpi_device *device)
2510 {
2511         struct acpi_hardware_id *hwid;
2512         int ret = 0;
2513
2514         list_for_each_entry(hwid, &device->pnp.ids, list) {
2515                 const struct acpi_device_id *devid;
2516                 struct acpi_scan_handler *handler;
2517
2518                 handler = acpi_scan_match_handler(hwid->id, &devid);
2519                 if (handler) {
2520                         if (!handler->attach) {
2521                                 device->pnp.type.platform_id = 0;
2522                                 continue;
2523                         }
2524                         device->handler = handler;
2525                         ret = handler->attach(device, devid);
2526                         if (ret > 0)
2527                                 break;
2528
2529                         device->handler = NULL;
2530                         if (ret < 0)
2531                                 break;
2532                 }
2533         }
2534
2535         return ret;
2536 }
2537
2538 static void acpi_bus_attach(struct acpi_device *device)
2539 {
2540         struct acpi_device *child;
2541         acpi_handle ejd;
2542         int ret;
2543
2544         if (ACPI_SUCCESS(acpi_bus_get_ejd(device->handle, &ejd)))
2545                 register_dock_dependent_device(device, ejd);
2546
2547         acpi_bus_get_status(device);
2548         /* Skip devices that are not present. */
2549         if (!acpi_device_is_present(device)) {
2550                 device->flags.visited = false;
2551                 device->flags.power_manageable = 0;
2552                 return;
2553         }
2554         if (device->handler)
2555                 goto ok;
2556
2557         if (!device->flags.initialized) {
2558                 device->flags.power_manageable =
2559                         device->power.states[ACPI_STATE_D0].flags.valid;
2560                 if (acpi_bus_init_power(device))
2561                         device->flags.power_manageable = 0;
2562
2563                 device->flags.initialized = true;
2564         }
2565         device->flags.visited = false;
2566         ret = acpi_scan_attach_handler(device);
2567         if (ret < 0)
2568                 return;
2569
2570         device->flags.match_driver = true;
2571         if (!ret) {
2572                 ret = device_attach(&device->dev);
2573                 if (ret < 0)
2574                         return;
2575
2576                 if (!ret && device->pnp.type.platform_id)
2577                         acpi_default_enumeration(device);
2578         }
2579         device->flags.visited = true;
2580
2581  ok:
2582         list_for_each_entry(child, &device->children, node)
2583                 acpi_bus_attach(child);
2584
2585         if (device->handler && device->handler->hotplug.notify_online)
2586                 device->handler->hotplug.notify_online(device);
2587 }
2588
2589 void acpi_walk_dep_device_list(acpi_handle handle)
2590 {
2591         struct acpi_dep_data *dep, *tmp;
2592         struct acpi_device *adev;
2593
2594         mutex_lock(&acpi_dep_list_lock);
2595         list_for_each_entry_safe(dep, tmp, &acpi_dep_list, node) {
2596                 if (dep->master == handle) {
2597                         acpi_bus_get_device(dep->slave, &adev);
2598                         if (!adev)
2599                                 continue;
2600
2601                         adev->dep_unmet--;
2602                         if (!adev->dep_unmet)
2603                                 acpi_bus_attach(adev);
2604                         list_del(&dep->node);
2605                         kfree(dep);
2606                 }
2607         }
2608         mutex_unlock(&acpi_dep_list_lock);
2609 }
2610 EXPORT_SYMBOL_GPL(acpi_walk_dep_device_list);
2611
2612 /**
2613  * acpi_bus_scan - Add ACPI device node objects in a given namespace scope.
2614  * @handle: Root of the namespace scope to scan.
2615  *
2616  * Scan a given ACPI tree (probably recently hot-plugged) and create and add
2617  * found devices.
2618  *
2619  * If no devices were found, -ENODEV is returned, but it does not mean that
2620  * there has been a real error.  There just have been no suitable ACPI objects
2621  * in the table trunk from which the kernel could create a device and add an
2622  * appropriate driver.
2623  *
2624  * Must be called under acpi_scan_lock.
2625  */
2626 int acpi_bus_scan(acpi_handle handle)
2627 {
2628         void *device = NULL;
2629
2630         if (ACPI_SUCCESS(acpi_bus_check_add(handle, 0, NULL, &device)))
2631                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
2632                                     acpi_bus_check_add, NULL, NULL, &device);
2633
2634         if (device) {
2635                 acpi_bus_attach(device);
2636                 return 0;
2637         }
2638         return -ENODEV;
2639 }
2640 EXPORT_SYMBOL(acpi_bus_scan);
2641
2642 /**
2643  * acpi_bus_trim - Detach scan handlers and drivers from ACPI device objects.
2644  * @adev: Root of the ACPI namespace scope to walk.
2645  *
2646  * Must be called under acpi_scan_lock.
2647  */
2648 void acpi_bus_trim(struct acpi_device *adev)
2649 {
2650         struct acpi_scan_handler *handler = adev->handler;
2651         struct acpi_device *child;
2652
2653         list_for_each_entry_reverse(child, &adev->children, node)
2654                 acpi_bus_trim(child);
2655
2656         adev->flags.match_driver = false;
2657         if (handler) {
2658                 if (handler->detach)
2659                         handler->detach(adev);
2660
2661                 adev->handler = NULL;
2662         } else {
2663                 device_release_driver(&adev->dev);
2664         }
2665         /*
2666          * Most likely, the device is going away, so put it into D3cold before
2667          * that.
2668          */
2669         acpi_device_set_power(adev, ACPI_STATE_D3_COLD);
2670         adev->flags.initialized = false;
2671         adev->flags.visited = false;
2672 }
2673 EXPORT_SYMBOL_GPL(acpi_bus_trim);
2674
2675 static int acpi_bus_scan_fixed(void)
2676 {
2677         int result = 0;
2678
2679         /*
2680          * Enumerate all fixed-feature devices.
2681          */
2682         if (!(acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON)) {
2683                 struct acpi_device *device = NULL;
2684
2685                 result = acpi_add_single_object(&device, NULL,
2686                                                 ACPI_BUS_TYPE_POWER_BUTTON,
2687                                                 ACPI_STA_DEFAULT);
2688                 if (result)
2689                         return result;
2690
2691                 device->flags.match_driver = true;
2692                 result = device_attach(&device->dev);
2693                 if (result < 0)
2694                         return result;
2695
2696                 device_init_wakeup(&device->dev, true);
2697         }
2698
2699         if (!(acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON)) {
2700                 struct acpi_device *device = NULL;
2701
2702                 result = acpi_add_single_object(&device, NULL,
2703                                                 ACPI_BUS_TYPE_SLEEP_BUTTON,
2704                                                 ACPI_STA_DEFAULT);
2705                 if (result)
2706                         return result;
2707
2708                 device->flags.match_driver = true;
2709                 result = device_attach(&device->dev);
2710         }
2711
2712         return result < 0 ? result : 0;
2713 }
2714
2715 int __init acpi_scan_init(void)
2716 {
2717         int result;
2718
2719         result = bus_register(&acpi_bus_type);
2720         if (result) {
2721                 /* We don't want to quit even if we failed to add suspend/resume */
2722                 printk(KERN_ERR PREFIX "Could not register bus type\n");
2723         }
2724
2725         acpi_pci_root_init();
2726         acpi_pci_link_init();
2727         acpi_processor_init();
2728         acpi_lpss_init();
2729         acpi_apd_init();
2730         acpi_cmos_rtc_init();
2731         acpi_container_init();
2732         acpi_memory_hotplug_init();
2733         acpi_pnp_init();
2734         acpi_int340x_thermal_init();
2735
2736         acpi_scan_add_handler(&generic_device_handler);
2737
2738         mutex_lock(&acpi_scan_lock);
2739         /*
2740          * Enumerate devices in the ACPI namespace.
2741          */
2742         result = acpi_bus_scan(ACPI_ROOT_OBJECT);
2743         if (result)
2744                 goto out;
2745
2746         result = acpi_bus_get_device(ACPI_ROOT_OBJECT, &acpi_root);
2747         if (result)
2748                 goto out;
2749
2750         /* Fixed feature devices do not exist on HW-reduced platform */
2751         if (!acpi_gbl_reduced_hardware) {
2752                 result = acpi_bus_scan_fixed();
2753                 if (result) {
2754                         acpi_detach_data(acpi_root->handle,
2755                                          acpi_scan_drop_device);
2756                         acpi_device_del(acpi_root);
2757                         put_device(&acpi_root->dev);
2758                         goto out;
2759                 }
2760         }
2761
2762         acpi_update_all_gpes();
2763
2764  out:
2765         mutex_unlock(&acpi_scan_lock);
2766         return result;
2767 }