kernel/drivers/acpi/scan.c

   1 /*
   2  * scan.c - support for transforming the ACPI namespace into individual objects
   3  */
   4
   5 #include <linux/module.h>
   6 #include <linux/init.h>
   7 #include <linux/slab.h>
   8 #include <linux/kernel.h>
   9 #include <linux/acpi.h>
  10 #include <linux/signal.h>
  11 #include <linux/kthread.h>
  12 #include <linux/dmi.h>
  13 #include <linux/nls.h>
  14
  15 #include <asm/pgtable.h>
  16
  17 #include "internal.h"
  18
  19 #define _COMPONENT              ACPI_BUS_COMPONENT
  20 ACPI_MODULE_NAME("scan");
  21 extern struct acpi_device *acpi_root;
  22
  23 #define ACPI_BUS_CLASS                  "system_bus"
  24 #define ACPI_BUS_HID                    "LNXSYBUS"
  25 #define ACPI_BUS_DEVICE_NAME            "System Bus"
  26
  27 #define ACPI_IS_ROOT_DEVICE(device)    (!(device)->parent)
  28
  29 #define INVALID_ACPI_HANDLE     ((acpi_handle)empty_zero_page)
  30
  31 /*
  32  * If set, devices will be hot-removed even if they cannot be put offline
  33  * gracefully (from the kernel's standpoint).
  34  */
  35 bool acpi_force_hot_remove;
  36
  37 static const char *dummy_hid = "device";
  38
  39 static LIST_HEAD(acpi_dep_list);
  40 static DEFINE_MUTEX(acpi_dep_list_lock);
  41 static LIST_HEAD(acpi_bus_id_list);
  42 static DEFINE_MUTEX(acpi_scan_lock);
  43 static LIST_HEAD(acpi_scan_handlers_list);
  44 DEFINE_MUTEX(acpi_device_lock);
  45 LIST_HEAD(acpi_wakeup_device_list);
  46 static DEFINE_MUTEX(acpi_hp_context_lock);
  47
  48 struct acpi_dep_data {
  49         struct list_head node;
  50         acpi_handle master;
  51         acpi_handle slave;
  52 };
  53
  54 struct acpi_device_bus_id{
  55         char bus_id[15];
  56         unsigned int instance_no;
  57         struct list_head node;
  58 };
  59
  60 void acpi_scan_lock_acquire(void)
  61 {
  62         mutex_lock(&acpi_scan_lock);
  63 }
  64 EXPORT_SYMBOL_GPL(acpi_scan_lock_acquire);
  65
  66 void acpi_scan_lock_release(void)
  67 {
  68         mutex_unlock(&acpi_scan_lock);
  69 }
  70 EXPORT_SYMBOL_GPL(acpi_scan_lock_release);
  71
  72 void acpi_lock_hp_context(void)
  73 {
  74         mutex_lock(&acpi_hp_context_lock);
  75 }
  76
  77 void acpi_unlock_hp_context(void)
  78 {
  79         mutex_unlock(&acpi_hp_context_lock);
  80 }
  81
  82 void acpi_initialize_hp_context(struct acpi_device *adev,
  83                                 struct acpi_hotplug_context *hp,
  84                                 int (*notify)(struct acpi_device *, u32),
  85                                 void (*uevent)(struct acpi_device *, u32))
  86 {
  87         acpi_lock_hp_context();
  88         hp->notify = notify;
  89         hp->uevent = uevent;
  90         acpi_set_hp_context(adev, hp);
  91         acpi_unlock_hp_context();
  92 }
  93 EXPORT_SYMBOL_GPL(acpi_initialize_hp_context);
  94
  95 int acpi_scan_add_handler(struct acpi_scan_handler *handler)
  96 {
  97         if (!handler)
  98                 return -EINVAL;
  99
 100         list_add_tail(&handler->list_node, &acpi_scan_handlers_list);
 101         return 0;
 102 }
 103
 104 int acpi_scan_add_handler_with_hotplug(struct acpi_scan_handler *handler,
 105                                        const char *hotplug_profile_name)
 106 {
 107         int error;
 108
 109         error = acpi_scan_add_handler(handler);
 110         if (error)
 111                 return error;
 112
 113         acpi_sysfs_add_hotplug_profile(&handler->hotplug, hotplug_profile_name);
 114         return 0;
 115 }
 116
 117 /**
 118  * create_pnp_modalias - Create hid/cid(s) string for modalias and uevent
 119  * @acpi_dev: ACPI device object.
 120  * @modalias: Buffer to print into.
 121  * @size: Size of the buffer.
 122  *
 123  * Creates hid/cid(s) string needed for modalias and uevent
 124  * e.g. on a device with hid:IBM0001 and cid:ACPI0001 you get:
 125  * char *modalias: "acpi:IBM0001:ACPI0001"
 126  * Return: 0: no _HID and no _CID
 127  *         -EINVAL: output error
 128  *         -ENOMEM: output is truncated
 129 */
 130 static int create_pnp_modalias(struct acpi_device *acpi_dev, char *modalias,
 131                                int size)
 132 {
 133         int len;
 134         int count;
 135         struct acpi_hardware_id *id;
 136
 137         /*
 138          * Since we skip PRP0001 from the modalias below, 0 should be returned
 139          * if PRP0001 is the only ACPI/PNP ID in the device's list.
 140          */
 141         count = 0;
 142         list_for_each_entry(id, &acpi_dev->pnp.ids, list)
 143                 if (strcmp(id->id, "PRP0001"))
 144                         count++;
 145
 146         if (!count)
 147                 return 0;
 148
 149         len = snprintf(modalias, size, "acpi:");
 150         if (len <= 0)
 151                 return len;
 152
 153         size -= len;
 154
 155         list_for_each_entry(id, &acpi_dev->pnp.ids, list) {
 156                 if (!strcmp(id->id, "PRP0001"))
 157                         continue;
 158
 159                 count = snprintf(&modalias[len], size, "%s:", id->id);
 160                 if (count < 0)
 161                         return -EINVAL;
 162
 163                 if (count >= size)
 164                         return -ENOMEM;
 165
 166                 len += count;
 167                 size -= count;
 168         }
 169         modalias[len] = '\0';
 170         return len;
 171 }
 172
 173 /**
 174  * create_of_modalias - Creates DT compatible string for modalias and uevent
 175  * @acpi_dev: ACPI device object.
 176  * @modalias: Buffer to print into.
 177  * @size: Size of the buffer.
 178  *
 179  * Expose DT compatible modalias as of:NnameTCcompatible.  This function should
 180  * only be called for devices having PRP0001 in their list of ACPI/PNP IDs.
 181  */
 182 static int create_of_modalias(struct acpi_device *acpi_dev, char *modalias,
 183                               int size)
 184 {
 185         struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
 186         const union acpi_object *of_compatible, *obj;
 187         int len, count;
 188         int i, nval;
 189         char *c;
 190
 191         acpi_get_name(acpi_dev->handle, ACPI_SINGLE_NAME, &buf);
 192         /* DT strings are all in lower case */
 193         for (c = buf.pointer; *c != '\0'; c++)
 194                 *c = tolower(*c);
 195
 196         len = snprintf(modalias, size, "of:N%sT", (char *)buf.pointer);
 197         ACPI_FREE(buf.pointer);
 198
 199         if (len <= 0)
 200                 return len;
 201
 202         of_compatible = acpi_dev->data.of_compatible;
 203         if (of_compatible->type == ACPI_TYPE_PACKAGE) {
 204                 nval = of_compatible->package.count;
 205                 obj = of_compatible->package.elements;
 206         } else { /* Must be ACPI_TYPE_STRING. */
 207                 nval = 1;
 208                 obj = of_compatible;
 209         }
 210         for (i = 0; i < nval; i++, obj++) {
 211                 count = snprintf(&modalias[len], size, "C%s",
 212                                  obj->string.pointer);
 213                 if (count < 0)
 214                         return -EINVAL;
 215
 216                 if (count >= size)
 217                         return -ENOMEM;
 218
 219                 len += count;
 220                 size -= count;
 221         }
 222         modalias[len] = '\0';
 223         return len;
 224 }
 225
 226 /*
 227  * acpi_companion_match() - Can we match via ACPI companion device
 228  * @dev: Device in question
 229  *
 230  * Check if the given device has an ACPI companion and if that companion has
 231  * a valid list of PNP IDs, and if the device is the first (primary) physical
 232  * device associated with it.  Return the companion pointer if that's the case
 233  * or NULL otherwise.
 234  *
 235  * If multiple physical devices are attached to a single ACPI companion, we need
 236  * to be careful.  The usage scenario for this kind of relationship is that all
 237  * of the physical devices in question use resources provided by the ACPI
 238  * companion.  A typical case is an MFD device where all the sub-devices share
 239  * the parent's ACPI companion.  In such cases we can only allow the primary
 240  * (first) physical device to be matched with the help of the companion's PNP
 241  * IDs.
 242  *
 243  * Additional physical devices sharing the ACPI companion can still use
 244  * resources available from it but they will be matched normally using functions
 245  * provided by their bus types (and analogously for their modalias).
 246  */
 247 static struct acpi_device *acpi_companion_match(const struct device *dev)
 248 {
 249         struct acpi_device *adev;
 250         struct mutex *physical_node_lock;
 251
 252         adev = ACPI_COMPANION(dev);
 253         if (!adev)
 254                 return NULL;
 255
 256         if (list_empty(&adev->pnp.ids))
 257                 return NULL;
 258
 259         physical_node_lock = &adev->physical_node_lock;
 260         mutex_lock(physical_node_lock);
 261         if (list_empty(&adev->physical_node_list)) {
 262                 adev = NULL;
 263         } else {
 264                 const struct acpi_device_physical_node *node;
 265
 266                 node = list_first_entry(&adev->physical_node_list,
 267                                         struct acpi_device_physical_node, node);
 268                 if (node->dev != dev)
 269                         adev = NULL;
 270         }
 271         mutex_unlock(physical_node_lock);
 272
 273         return adev;
 274 }
 275
 276 static int __acpi_device_uevent_modalias(struct acpi_device *adev,
 277                                          struct kobj_uevent_env *env)
 278 {
 279         int len;
 280
 281         if (!adev)
 282                 return -ENODEV;
 283
 284         if (list_empty(&adev->pnp.ids))
 285                 return 0;
 286
 287         if (add_uevent_var(env, "MODALIAS="))
 288                 return -ENOMEM;
 289
 290         len = create_pnp_modalias(adev, &env->buf[env->buflen - 1],
 291                                   sizeof(env->buf) - env->buflen);
 292         if (len < 0)
 293                 return len;
 294
 295         env->buflen += len;
 296         if (!adev->data.of_compatible)
 297                 return 0;
 298
 299         if (len > 0 && add_uevent_var(env, "MODALIAS="))
 300                 return -ENOMEM;
 301
 302         len = create_of_modalias(adev, &env->buf[env->buflen - 1],
 303                                  sizeof(env->buf) - env->buflen);
 304         if (len < 0)
 305                 return len;
 306
 307         env->buflen += len;
 308
 309         return 0;
 310 }
 311
 312 /*
 313  * Creates uevent modalias field for ACPI enumerated devices.
 314  * Because the other buses does not support ACPI HIDs & CIDs.
 315  * e.g. for a device with hid:IBM0001 and cid:ACPI0001 you get:
 316  * "acpi:IBM0001:ACPI0001"
 317  */
 318 int acpi_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
 319 {
 320         return __acpi_device_uevent_modalias(acpi_companion_match(dev), env);
 321 }
 322 EXPORT_SYMBOL_GPL(acpi_device_uevent_modalias);
 323
 324 static int __acpi_device_modalias(struct acpi_device *adev, char *buf, int size)
 325 {
 326         int len, count;
 327
 328         if (!adev)
 329                 return -ENODEV;
 330
 331         if (list_empty(&adev->pnp.ids))
 332                 return 0;
 333
 334         len = create_pnp_modalias(adev, buf, size - 1);
 335         if (len < 0) {
 336                 return len;
 337         } else if (len > 0) {
 338                 buf[len++] = '\n';
 339                 size -= len;
 340         }
 341         if (!adev->data.of_compatible)
 342                 return len;
 343
 344         count = create_of_modalias(adev, buf + len, size - 1);
 345         if (count < 0) {
 346                 return count;
 347         } else if (count > 0) {
 348                 len += count;
 349                 buf[len++] = '\n';
 350         }
 351
 352         return len;
 353 }
 354
 355 /*
 356  * Creates modalias sysfs attribute for ACPI enumerated devices.
 357  * Because the other buses does not support ACPI HIDs & CIDs.
 358  * e.g. for a device with hid:IBM0001 and cid:ACPI0001 you get:
 359  * "acpi:IBM0001:ACPI0001"
 360  */
 361 int acpi_device_modalias(struct device *dev, char *buf, int size)
 362 {
 363         return __acpi_device_modalias(acpi_companion_match(dev), buf, size);
 364 }
 365 EXPORT_SYMBOL_GPL(acpi_device_modalias);
 366
 367 static ssize_t
 368 acpi_device_modalias_show(struct device *dev, struct device_attribute *attr, char *buf) {
 369         return __acpi_device_modalias(to_acpi_device(dev), buf, 1024);
 370 }
 371 static DEVICE_ATTR(modalias, 0444, acpi_device_modalias_show, NULL);
 372
 373 bool acpi_scan_is_offline(struct acpi_device *adev, bool uevent)
 374 {
 375         struct acpi_device_physical_node *pn;
 376         bool offline = true;
 377
 378         /*
 379          * acpi_container_offline() calls this for all of the container's
 380          * children under the container's physical_node_lock lock.
 381          */
 382         mutex_lock_nested(&adev->physical_node_lock, SINGLE_DEPTH_NESTING);
 383
 384         list_for_each_entry(pn, &adev->physical_node_list, node)
 385                 if (device_supports_offline(pn->dev) && !pn->dev->offline) {
 386                         if (uevent)
 387                                 kobject_uevent(&pn->dev->kobj, KOBJ_CHANGE);
 388
 389                         offline = false;
 390                         break;
 391                 }
 392
 393         mutex_unlock(&adev->physical_node_lock);
 394         return offline;
 395 }
 396
 397 static acpi_status acpi_bus_offline(acpi_handle handle, u32 lvl, void *data,
 398                                     void **ret_p)
 399 {
 400         struct acpi_device *device = NULL;
 401         struct acpi_device_physical_node *pn;
 402         bool second_pass = (bool)data;
 403         acpi_status status = AE_OK;
 404
 405         if (acpi_bus_get_device(handle, &device))
 406                 return AE_OK;
 407
 408         if (device->handler && !device->handler->hotplug.enabled) {
 409                 *ret_p = &device->dev;
 410                 return AE_SUPPORT;
 411         }
 412
 413         mutex_lock(&device->physical_node_lock);
 414
 415         list_for_each_entry(pn, &device->physical_node_list, node) {
 416                 int ret;
 417
 418                 if (second_pass) {
 419                         /* Skip devices offlined by the first pass. */
 420                         if (pn->put_online)
 421                                 continue;
 422                 } else {
 423                         pn->put_online = false;
 424                 }
 425                 ret = device_offline(pn->dev);
 426                 if (acpi_force_hot_remove)
 427                         continue;
 428
 429                 if (ret >= 0) {
 430                         pn->put_online = !ret;
 431                 } else {
 432                         *ret_p = pn->dev;
 433                         if (second_pass) {
 434                                 status = AE_ERROR;
 435                                 break;
 436                         }
 437                 }
 438         }
 439
 440         mutex_unlock(&device->physical_node_lock);
 441
 442         return status;
 443 }
 444
 445 static acpi_status acpi_bus_online(acpi_handle handle, u32 lvl, void *data,
 446                                    void **ret_p)
 447 {
 448         struct acpi_device *device = NULL;
 449         struct acpi_device_physical_node *pn;
 450
 451         if (acpi_bus_get_device(handle, &device))
 452                 return AE_OK;
 453
 454         mutex_lock(&device->physical_node_lock);
 455
 456         list_for_each_entry(pn, &device->physical_node_list, node)
 457                 if (pn->put_online) {
 458                         device_online(pn->dev);
 459                         pn->put_online = false;
 460                 }
 461
 462         mutex_unlock(&device->physical_node_lock);
 463
 464         return AE_OK;
 465 }
 466
 467 static int acpi_scan_try_to_offline(struct acpi_device *device)
 468 {
 469         acpi_handle handle = device->handle;
 470         struct device *errdev = NULL;
 471         acpi_status status;
 472
 473         /*
 474          * Carry out two passes here and ignore errors in the first pass,
 475          * because if the devices in question are memory blocks and
 476          * CONFIG_MEMCG is set, one of the blocks may hold data structures
 477          * that the other blocks depend on, but it is not known in advance which
 478          * block holds them.
 479          *
 480          * If the first pass is successful, the second one isn't needed, though.
 481          */
 482         status = acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
 483                                      NULL, acpi_bus_offline, (void *)false,
 484                                      (void **)&errdev);
 485         if (status == AE_SUPPORT) {
 486                 dev_warn(errdev, "Offline disabled.\n");
 487                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
 488                                     acpi_bus_online, NULL, NULL, NULL);
 489                 return -EPERM;
 490         }
 491         acpi_bus_offline(handle, 0, (void *)false, (void **)&errdev);
 492         if (errdev) {
 493                 errdev = NULL;
 494                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
 495                                     NULL, acpi_bus_offline, (void *)true,
 496                                     (void **)&errdev);
 497                 if (!errdev || acpi_force_hot_remove)
 498                         acpi_bus_offline(handle, 0, (void *)true,
 499                                          (void **)&errdev);
 500
 501                 if (errdev && !acpi_force_hot_remove) {
 502                         dev_warn(errdev, "Offline failed.\n");
 503                         acpi_bus_online(handle, 0, NULL, NULL);
 504                         acpi_walk_namespace(ACPI_TYPE_ANY, handle,
 505                                             ACPI_UINT32_MAX, acpi_bus_online,
 506                                             NULL, NULL, NULL);
 507                         return -EBUSY;
 508                 }
 509         }
 510         return 0;
 511 }
 512
 513 static int acpi_scan_hot_remove(struct acpi_device *device)
 514 {
 515         acpi_handle handle = device->handle;
 516         unsigned long long sta;
 517         acpi_status status;
 518
 519         if (device->handler && device->handler->hotplug.demand_offline
 520             && !acpi_force_hot_remove) {
 521                 if (!acpi_scan_is_offline(device, true))
 522                         return -EBUSY;
 523         } else {
 524                 int error = acpi_scan_try_to_offline(device);
 525                 if (error)
 526                         return error;
 527         }
 528
 529         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 530                 "Hot-removing device %s...\n", dev_name(&device->dev)));
 531
 532         acpi_bus_trim(device);
 533
 534         acpi_evaluate_lck(handle, 0);
 535         /*
 536          * TBD: _EJD support.
 537          */
 538         status = acpi_evaluate_ej0(handle);
 539         if (status == AE_NOT_FOUND)
 540                 return -ENODEV;
 541         else if (ACPI_FAILURE(status))
 542                 return -EIO;
 543
 544         /*
 545          * Verify if eject was indeed successful.  If not, log an error
 546          * message.  No need to call _OST since _EJ0 call was made OK.
 547          */
 548         status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
 549         if (ACPI_FAILURE(status)) {
 550                 acpi_handle_warn(handle,
 551                         "Status check after eject failed (0x%x)\n", status);
 552         } else if (sta & ACPI_STA_DEVICE_ENABLED) {
 553                 acpi_handle_warn(handle,
 554                         "Eject incomplete - status 0x%llx\n", sta);
 555         }
 556
 557         return 0;
 558 }
 559
 560 static int acpi_scan_device_not_present(struct acpi_device *adev)
 561 {
 562         if (!acpi_device_enumerated(adev)) {
 563                 dev_warn(&adev->dev, "Still not present\n");
 564                 return -EALREADY;
 565         }
 566         acpi_bus_trim(adev);
 567         return 0;
 568 }
 569
 570 static int acpi_scan_device_check(struct acpi_device *adev)
 571 {
 572         int error;
 573
 574         acpi_bus_get_status(adev);
 575         if (adev->status.present || adev->status.functional) {
 576                 /*
 577                  * This function is only called for device objects for which
 578                  * matching scan handlers exist.  The only situation in which
 579                  * the scan handler is not attached to this device object yet
 580                  * is when the device has just appeared (either it wasn't
 581                  * present at all before or it was removed and then added
 582                  * again).
 583                  */
 584                 if (adev->handler) {
 585                         dev_warn(&adev->dev, "Already enumerated\n");
 586                         return -EALREADY;
 587                 }
 588                 error = acpi_bus_scan(adev->handle);
 589                 if (error) {
 590                         dev_warn(&adev->dev, "Namespace scan failure\n");
 591                         return error;
 592                 }
 593                 if (!adev->handler) {
 594                         dev_warn(&adev->dev, "Enumeration failure\n");
 595                         error = -ENODEV;
 596                 }
 597         } else {
 598                 error = acpi_scan_device_not_present(adev);
 599         }
 600         return error;
 601 }
 602
 603 static int acpi_scan_bus_check(struct acpi_device *adev)
 604 {
 605         struct acpi_scan_handler *handler = adev->handler;
 606         struct acpi_device *child;
 607         int error;
 608
 609         acpi_bus_get_status(adev);
 610         if (!(adev->status.present || adev->status.functional)) {
 611                 acpi_scan_device_not_present(adev);
 612                 return 0;
 613         }
 614         if (handler && handler->hotplug.scan_dependent)
 615                 return handler->hotplug.scan_dependent(adev);
 616
 617         error = acpi_bus_scan(adev->handle);
 618         if (error) {
 619                 dev_warn(&adev->dev, "Namespace scan failure\n");
 620                 return error;
 621         }
 622         list_for_each_entry(child, &adev->children, node) {
 623                 error = acpi_scan_bus_check(child);
 624                 if (error)
 625                         return error;
 626         }
 627         return 0;
 628 }
 629
 630 static int acpi_generic_hotplug_event(struct acpi_device *adev, u32 type)
 631 {
 632         switch (type) {
 633         case ACPI_NOTIFY_BUS_CHECK:
 634                 return acpi_scan_bus_check(adev);
 635         case ACPI_NOTIFY_DEVICE_CHECK:
 636                 return acpi_scan_device_check(adev);
 637         case ACPI_NOTIFY_EJECT_REQUEST:
 638         case ACPI_OST_EC_OSPM_EJECT:
 639                 if (adev->handler && !adev->handler->hotplug.enabled) {
 640                         dev_info(&adev->dev, "Eject disabled\n");
 641                         return -EPERM;
 642                 }
 643                 acpi_evaluate_ost(adev->handle, ACPI_NOTIFY_EJECT_REQUEST,
 644                                   ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
 645                 return acpi_scan_hot_remove(adev);
 646         }
 647         return -EINVAL;
 648 }
 649
 650 void acpi_device_hotplug(struct acpi_device *adev, u32 src)
 651 {
 652         u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
 653         int error = -ENODEV;
 654
 655         lock_device_hotplug();
 656         mutex_lock(&acpi_scan_lock);
 657
 658         /*
 659          * The device object's ACPI handle cannot become invalid as long as we
 660          * are holding acpi_scan_lock, but it might have become invalid before
 661          * that lock was acquired.
 662          */
 663         if (adev->handle == INVALID_ACPI_HANDLE)
 664                 goto err_out;
 665
 666         if (adev->flags.is_dock_station) {
 667                 error = dock_notify(adev, src);
 668         } else if (adev->flags.hotplug_notify) {
 669                 error = acpi_generic_hotplug_event(adev, src);
 670                 if (error == -EPERM) {
 671                         ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
 672                         goto err_out;
 673                 }
 674         } else {
 675                 int (*notify)(struct acpi_device *, u32);
 676
 677                 acpi_lock_hp_context();
 678                 notify = adev->hp ? adev->hp->notify : NULL;
 679                 acpi_unlock_hp_context();
 680                 /*
 681                  * There may be additional notify handlers for device objects
 682                  * without the .event() callback, so ignore them here.
 683                  */
 684                 if (notify)
 685                         error = notify(adev, src);
 686                 else
 687                         goto out;
 688         }
 689         if (!error)
 690                 ost_code = ACPI_OST_SC_SUCCESS;
 691
 692  err_out:
 693         acpi_evaluate_ost(adev->handle, src, ost_code, NULL);
 694
 695  out:
 696         acpi_bus_put_acpi_device(adev);
 697         mutex_unlock(&acpi_scan_lock);
 698         unlock_device_hotplug();
 699 }
 700
 701 static ssize_t real_power_state_show(struct device *dev,
 702                                      struct device_attribute *attr, char *buf)
 703 {
 704         struct acpi_device *adev = to_acpi_device(dev);
 705         int state;
 706         int ret;
 707
 708         ret = acpi_device_get_power(adev, &state);
 709         if (ret)
 710                 return ret;
 711
 712         return sprintf(buf, "%s\n", acpi_power_state_string(state));
 713 }
 714
 715 static DEVICE_ATTR(real_power_state, 0444, real_power_state_show, NULL);
 716
 717 static ssize_t power_state_show(struct device *dev,
 718                                 struct device_attribute *attr, char *buf)
 719 {
 720         struct acpi_device *adev = to_acpi_device(dev);
 721
 722         return sprintf(buf, "%s\n", acpi_power_state_string(adev->power.state));
 723 }
 724
 725 static DEVICE_ATTR(power_state, 0444, power_state_show, NULL);
 726
 727 static ssize_t
 728 acpi_eject_store(struct device *d, struct device_attribute *attr,
 729                 const char *buf, size_t count)
 730 {
 731         struct acpi_device *acpi_device = to_acpi_device(d);
 732         acpi_object_type not_used;
 733         acpi_status status;
 734
 735         if (!count || buf[0] != '1')
 736                 return -EINVAL;
 737
 738         if ((!acpi_device->handler || !acpi_device->handler->hotplug.enabled)
 739             && !acpi_device->driver)
 740                 return -ENODEV;
 741
 742         status = acpi_get_type(acpi_device->handle, &not_used);
 743         if (ACPI_FAILURE(status) || !acpi_device->flags.ejectable)
 744                 return -ENODEV;
 745
 746         get_device(&acpi_device->dev);
 747         status = acpi_hotplug_schedule(acpi_device, ACPI_OST_EC_OSPM_EJECT);
 748         if (ACPI_SUCCESS(status))
 749                 return count;
 750
 751         put_device(&acpi_device->dev);
 752         acpi_evaluate_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,
 753                           ACPI_OST_SC_NON_SPECIFIC_FAILURE, NULL);
 754         return status == AE_NO_MEMORY ? -ENOMEM : -EAGAIN;
 755 }
 756
 757 static DEVICE_ATTR(eject, 0200, NULL, acpi_eject_store);
 758
 759 static ssize_t
 760 acpi_device_hid_show(struct device *dev, struct device_attribute *attr, char *buf) {
 761         struct acpi_device *acpi_dev = to_acpi_device(dev);
 762
 763         return sprintf(buf, "%s\n", acpi_device_hid(acpi_dev));
 764 }
 765 static DEVICE_ATTR(hid, 0444, acpi_device_hid_show, NULL);
 766
 767 static ssize_t acpi_device_uid_show(struct device *dev,
 768                                     struct device_attribute *attr, char *buf)
 769 {
 770         struct acpi_device *acpi_dev = to_acpi_device(dev);
 771
 772         return sprintf(buf, "%s\n", acpi_dev->pnp.unique_id);
 773 }
 774 static DEVICE_ATTR(uid, 0444, acpi_device_uid_show, NULL);
 775
 776 static ssize_t acpi_device_adr_show(struct device *dev,
 777                                     struct device_attribute *attr, char *buf)
 778 {
 779         struct acpi_device *acpi_dev = to_acpi_device(dev);
 780
 781         return sprintf(buf, "0x%08x\n",
 782                        (unsigned int)(acpi_dev->pnp.bus_address));
 783 }
 784 static DEVICE_ATTR(adr, 0444, acpi_device_adr_show, NULL);
 785
 786 static ssize_t
 787 acpi_device_path_show(struct device *dev, struct device_attribute *attr, char *buf) {
 788         struct acpi_device *acpi_dev = to_acpi_device(dev);
 789         struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
 790         int result;
 791
 792         result = acpi_get_name(acpi_dev->handle, ACPI_FULL_PATHNAME, &path);
 793         if (result)
 794                 goto end;
 795
 796         result = sprintf(buf, "%s\n", (char*)path.pointer);
 797         kfree(path.pointer);
 798 end:
 799         return result;
 800 }
 801 static DEVICE_ATTR(path, 0444, acpi_device_path_show, NULL);
 802
 803 /* sysfs file that shows description text from the ACPI _STR method */
 804 static ssize_t description_show(struct device *dev,
 805                                 struct device_attribute *attr,
 806                                 char *buf) {
 807         struct acpi_device *acpi_dev = to_acpi_device(dev);
 808         int result;
 809
 810         if (acpi_dev->pnp.str_obj == NULL)
 811                 return 0;
 812
 813         /*
 814          * The _STR object contains a Unicode identifier for a device.
 815          * We need to convert to utf-8 so it can be displayed.
 816          */
 817         result = utf16s_to_utf8s(
 818                 (wchar_t *)acpi_dev->pnp.str_obj->buffer.pointer,
 819                 acpi_dev->pnp.str_obj->buffer.length,
 820                 UTF16_LITTLE_ENDIAN, buf,
 821                 PAGE_SIZE);
 822
 823         buf[result++] = '\n';
 824
 825         return result;
 826 }
 827 static DEVICE_ATTR(description, 0444, description_show, NULL);
 828
 829 static ssize_t
 830 acpi_device_sun_show(struct device *dev, struct device_attribute *attr,
 831                      char *buf) {
 832         struct acpi_device *acpi_dev = to_acpi_device(dev);
 833         acpi_status status;
 834         unsigned long long sun;
 835
 836         status = acpi_evaluate_integer(acpi_dev->handle, "_SUN", NULL, &sun);
 837         if (ACPI_FAILURE(status))
 838                 return -ENODEV;
 839
 840         return sprintf(buf, "%llu\n", sun);
 841 }
 842 static DEVICE_ATTR(sun, 0444, acpi_device_sun_show, NULL);
 843
 844 static ssize_t status_show(struct device *dev, struct device_attribute *attr,
 845                                 char *buf) {
 846         struct acpi_device *acpi_dev = to_acpi_device(dev);
 847         acpi_status status;
 848         unsigned long long sta;
 849
 850         status = acpi_evaluate_integer(acpi_dev->handle, "_STA", NULL, &sta);
 851         if (ACPI_FAILURE(status))
 852                 return -ENODEV;
 853
 854         return sprintf(buf, "%llu\n", sta);
 855 }
 856 static DEVICE_ATTR_RO(status);
 857
 858 static int acpi_device_setup_files(struct acpi_device *dev)
 859 {
 860         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
 861         acpi_status status;
 862         int result = 0;
 863
 864         /*
 865          * Devices gotten from FADT don't have a "path" attribute
 866          */
 867         if (dev->handle) {
 868                 result = device_create_file(&dev->dev, &dev_attr_path);
 869                 if (result)
 870                         goto end;
 871         }
 872
 873         if (!list_empty(&dev->pnp.ids)) {
 874                 result = device_create_file(&dev->dev, &dev_attr_hid);
 875                 if (result)
 876                         goto end;
 877
 878                 result = device_create_file(&dev->dev, &dev_attr_modalias);
 879                 if (result)
 880                         goto end;
 881         }
 882
 883         /*
 884          * If device has _STR, 'description' file is created
 885          */
 886         if (acpi_has_method(dev->handle, "_STR")) {
 887                 status = acpi_evaluate_object(dev->handle, "_STR",
 888                                         NULL, &buffer);
 889                 if (ACPI_FAILURE(status))
 890                         buffer.pointer = NULL;
 891                 dev->pnp.str_obj = buffer.pointer;
 892                 result = device_create_file(&dev->dev, &dev_attr_description);
 893                 if (result)
 894                         goto end;
 895         }
 896
 897         if (dev->pnp.type.bus_address)
 898                 result = device_create_file(&dev->dev, &dev_attr_adr);
 899         if (dev->pnp.unique_id)
 900                 result = device_create_file(&dev->dev, &dev_attr_uid);
 901
 902         if (acpi_has_method(dev->handle, "_SUN")) {
 903                 result = device_create_file(&dev->dev, &dev_attr_sun);
 904                 if (result)
 905                         goto end;
 906         }
 907
 908         if (acpi_has_method(dev->handle, "_STA")) {
 909                 result = device_create_file(&dev->dev, &dev_attr_status);
 910                 if (result)
 911                         goto end;
 912         }
 913
 914         /*
 915          * If device has _EJ0, 'eject' file is created that is used to trigger
 916          * hot-removal function from userland.
 917          */
 918         if (acpi_has_method(dev->handle, "_EJ0")) {
 919                 result = device_create_file(&dev->dev, &dev_attr_eject);
 920                 if (result)
 921                         return result;
 922         }
 923
 924         if (dev->flags.power_manageable) {
 925                 result = device_create_file(&dev->dev, &dev_attr_power_state);
 926                 if (result)
 927                         return result;
 928
 929                 if (dev->power.flags.power_resources)
 930                         result = device_create_file(&dev->dev,
 931                                                     &dev_attr_real_power_state);
 932         }
 933
 934 end:
 935         return result;
 936 }
 937
 938 static void acpi_device_remove_files(struct acpi_device *dev)
 939 {
 940         if (dev->flags.power_manageable) {
 941                 device_remove_file(&dev->dev, &dev_attr_power_state);
 942                 if (dev->power.flags.power_resources)
 943                         device_remove_file(&dev->dev,
 944                                            &dev_attr_real_power_state);
 945         }
 946
 947         /*
 948          * If device has _STR, remove 'description' file
 949          */
 950         if (acpi_has_method(dev->handle, "_STR")) {
 951                 kfree(dev->pnp.str_obj);
 952                 device_remove_file(&dev->dev, &dev_attr_description);
 953         }
 954         /*
 955          * If device has _EJ0, remove 'eject' file.
 956          */
 957         if (acpi_has_method(dev->handle, "_EJ0"))
 958                 device_remove_file(&dev->dev, &dev_attr_eject);
 959
 960         if (acpi_has_method(dev->handle, "_SUN"))
 961                 device_remove_file(&dev->dev, &dev_attr_sun);
 962
 963         if (dev->pnp.unique_id)
 964                 device_remove_file(&dev->dev, &dev_attr_uid);
 965         if (dev->pnp.type.bus_address)
 966                 device_remove_file(&dev->dev, &dev_attr_adr);
 967         device_remove_file(&dev->dev, &dev_attr_modalias);
 968         device_remove_file(&dev->dev, &dev_attr_hid);
 969         if (acpi_has_method(dev->handle, "_STA"))
 970                 device_remove_file(&dev->dev, &dev_attr_status);
 971         if (dev->handle)
 972                 device_remove_file(&dev->dev, &dev_attr_path);
 973 }
 974 /* --------------------------------------------------------------------------
 975                         ACPI Bus operations
 976    -------------------------------------------------------------------------- */
 977
 978 /**
 979  * acpi_of_match_device - Match device object using the "compatible" property.
 980  * @adev: ACPI device object to match.
 981  * @of_match_table: List of device IDs to match against.
 982  *
 983  * If @dev has an ACPI companion which has the special PRP0001 device ID in its
 984  * list of identifiers and a _DSD object with the "compatible" property, use
 985  * that property to match against the given list of identifiers.
 986  */
 987 static bool acpi_of_match_device(struct acpi_device *adev,
 988                                  const struct of_device_id *of_match_table)
 989 {
 990         const union acpi_object *of_compatible, *obj;
 991         int i, nval;
 992
 993         if (!adev)
 994                 return false;
 995
 996         of_compatible = adev->data.of_compatible;
 997         if (!of_match_table || !of_compatible)
 998                 return false;
 999
1000         if (of_compatible->type == ACPI_TYPE_PACKAGE) {
1001                 nval = of_compatible->package.count;
1002                 obj = of_compatible->package.elements;
1003         } else { /* Must be ACPI_TYPE_STRING. */
1004                 nval = 1;
1005                 obj = of_compatible;
1006         }
1007         /* Now we can look for the driver DT compatible strings */
1008         for (i = 0; i < nval; i++, obj++) {
1009                 const struct of_device_id *id;
1010
1011                 for (id = of_match_table; id->compatible[0]; id++)
1012                         if (!strcasecmp(obj->string.pointer, id->compatible))
1013                                 return true;
1014         }
1015
1016         return false;
1017 }
1018
1019 static const struct acpi_device_id *__acpi_match_device(
1020         struct acpi_device *device,
1021         const struct acpi_device_id *ids,
1022         const struct of_device_id *of_ids)
1023 {
1024         const struct acpi_device_id *id;
1025         struct acpi_hardware_id *hwid;
1026
1027         /*
1028          * If the device is not present, it is unnecessary to load device
1029          * driver for it.
1030          */
1031         if (!device || !device->status.present)
1032                 return NULL;
1033
1034         list_for_each_entry(hwid, &device->pnp.ids, list) {
1035                 /* First, check the ACPI/PNP IDs provided by the caller. */
1036                 for (id = ids; id->id[0]; id++)
1037                         if (!strcmp((char *) id->id, hwid->id))
1038                                 return id;
1039
1040                 /*
1041                  * Next, check the special "PRP0001" ID and try to match the
1042                  * "compatible" property if found.
1043                  *
1044                  * The id returned by the below is not valid, but the only
1045                  * caller passing non-NULL of_ids here is only interested in
1046                  * whether or not the return value is NULL.
1047                  */
1048                 if (!strcmp("PRP0001", hwid->id)
1049                     && acpi_of_match_device(device, of_ids))
1050                         return id;
1051         }
1052         return NULL;
1053 }
1054
1055 /**
1056  * acpi_match_device - Match a struct device against a given list of ACPI IDs
1057  * @ids: Array of struct acpi_device_id object to match against.
1058  * @dev: The device structure to match.
1059  *
1060  * Check if @dev has a valid ACPI handle and if there is a struct acpi_device
1061  * object for that handle and use that object to match against a given list of
1062  * device IDs.
1063  *
1064  * Return a pointer to the first matching ID on success or %NULL on failure.
1065  */
1066 const struct acpi_device_id *acpi_match_device(const struct acpi_device_id *ids,
1067                                                const struct device *dev)
1068 {
1069         return __acpi_match_device(acpi_companion_match(dev), ids, NULL);
1070 }
1071 EXPORT_SYMBOL_GPL(acpi_match_device);
1072
1073 int acpi_match_device_ids(struct acpi_device *device,
1074                           const struct acpi_device_id *ids)
1075 {
1076         return __acpi_match_device(device, ids, NULL) ? 0 : -ENOENT;
1077 }
1078 EXPORT_SYMBOL(acpi_match_device_ids);
1079
1080 bool acpi_driver_match_device(struct device *dev,
1081                               const struct device_driver *drv)
1082 {
1083         if (!drv->acpi_match_table)
1084                 return acpi_of_match_device(ACPI_COMPANION(dev),
1085                                             drv->of_match_table);
1086
1087         return !!__acpi_match_device(acpi_companion_match(dev),
1088                                      drv->acpi_match_table, drv->of_match_table);
1089 }
1090 EXPORT_SYMBOL_GPL(acpi_driver_match_device);
1091
1092 static void acpi_free_power_resources_lists(struct acpi_device *device)
1093 {
1094         int i;
1095
1096         if (device->wakeup.flags.valid)
1097                 acpi_power_resources_list_free(&device->wakeup.resources);
1098
1099         if (!device->power.flags.power_resources)
1100                 return;
1101
1102         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
1103                 struct acpi_device_power_state *ps = &device->power.states[i];
1104                 acpi_power_resources_list_free(&ps->resources);
1105         }
1106 }
1107
1108 static void acpi_device_release(struct device *dev)
1109 {
1110         struct acpi_device *acpi_dev = to_acpi_device(dev);
1111
1112         acpi_free_properties(acpi_dev);
1113         acpi_free_pnp_ids(&acpi_dev->pnp);
1114         acpi_free_power_resources_lists(acpi_dev);
1115         kfree(acpi_dev);
1116 }
1117
1118 static int acpi_bus_match(struct device *dev, struct device_driver *drv)
1119 {
1120         struct acpi_device *acpi_dev = to_acpi_device(dev);
1121         struct acpi_driver *acpi_drv = to_acpi_driver(drv);
1122
1123         return acpi_dev->flags.match_driver
1124                 && !acpi_match_device_ids(acpi_dev, acpi_drv->ids);
1125 }
1126
1127 static int acpi_device_uevent(struct device *dev, struct kobj_uevent_env *env)
1128 {
1129         return __acpi_device_uevent_modalias(to_acpi_device(dev), env);
1130 }
1131
1132 static void acpi_device_notify(acpi_handle handle, u32 event, void *data)
1133 {
1134         struct acpi_device *device = data;
1135
1136         device->driver->ops.notify(device, event);
1137 }
1138
1139 static void acpi_device_notify_fixed(void *data)
1140 {
1141         struct acpi_device *device = data;
1142
1143         /* Fixed hardware devices have no handles */
1144         acpi_device_notify(NULL, ACPI_FIXED_HARDWARE_EVENT, device);
1145 }
1146
1147 static u32 acpi_device_fixed_event(void *data)
1148 {
1149         acpi_os_execute(OSL_NOTIFY_HANDLER, acpi_device_notify_fixed, data);
1150         return ACPI_INTERRUPT_HANDLED;
1151 }
1152
1153 static int acpi_device_install_notify_handler(struct acpi_device *device)
1154 {
1155         acpi_status status;
1156
1157         if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
1158                 status =
1159                     acpi_install_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
1160                                                      acpi_device_fixed_event,
1161                                                      device);
1162         else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
1163                 status =
1164                     acpi_install_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
1165                                                      acpi_device_fixed_event,
1166                                                      device);
1167         else
1168                 status = acpi_install_notify_handler(device->handle,
1169                                                      ACPI_DEVICE_NOTIFY,
1170                                                      acpi_device_notify,
1171                                                      device);
1172
1173         if (ACPI_FAILURE(status))
1174                 return -EINVAL;
1175         return 0;
1176 }
1177
1178 static void acpi_device_remove_notify_handler(struct acpi_device *device)
1179 {
1180         if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
1181                 acpi_remove_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
1182                                                 acpi_device_fixed_event);
1183         else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
1184                 acpi_remove_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
1185                                                 acpi_device_fixed_event);
1186         else
1187                 acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
1188                                            acpi_device_notify);
1189 }
1190
1191 static int acpi_device_probe(struct device *dev)
1192 {
1193         struct acpi_device *acpi_dev = to_acpi_device(dev);
1194         struct acpi_driver *acpi_drv = to_acpi_driver(dev->driver);
1195         int ret;
1196
1197         if (acpi_dev->handler && !acpi_is_pnp_device(acpi_dev))
1198                 return -EINVAL;
1199
1200         if (!acpi_drv->ops.add)
1201                 return -ENOSYS;
1202
1203         ret = acpi_drv->ops.add(acpi_dev);
1204         if (ret)
1205                 return ret;
1206
1207         acpi_dev->driver = acpi_drv;
1208         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1209                           "Driver [%s] successfully bound to device [%s]\n",
1210                           acpi_drv->name, acpi_dev->pnp.bus_id));
1211
1212         if (acpi_drv->ops.notify) {
1213                 ret = acpi_device_install_notify_handler(acpi_dev);
1214                 if (ret) {
1215                         if (acpi_drv->ops.remove)
1216                                 acpi_drv->ops.remove(acpi_dev);
1217
1218                         acpi_dev->driver = NULL;
1219                         acpi_dev->driver_data = NULL;
1220                         return ret;
1221                 }
1222         }
1223
1224         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found driver [%s] for device [%s]\n",
1225                           acpi_drv->name, acpi_dev->pnp.bus_id));
1226         get_device(dev);
1227         return 0;
1228 }
1229
1230 static int acpi_device_remove(struct device * dev)
1231 {
1232         struct acpi_device *acpi_dev = to_acpi_device(dev);
1233         struct acpi_driver *acpi_drv = acpi_dev->driver;
1234
1235         if (acpi_drv) {
1236                 if (acpi_drv->ops.notify)
1237                         acpi_device_remove_notify_handler(acpi_dev);
1238                 if (acpi_drv->ops.remove)
1239                         acpi_drv->ops.remove(acpi_dev);
1240         }
1241         acpi_dev->driver = NULL;
1242         acpi_dev->driver_data = NULL;
1243
1244         put_device(dev);
1245         return 0;
1246 }
1247
1248 struct bus_type acpi_bus_type = {
1249         .name           = "acpi",
1250         .match          = acpi_bus_match,
1251         .probe          = acpi_device_probe,
1252         .remove         = acpi_device_remove,
1253         .uevent         = acpi_device_uevent,
1254 };
1255
1256 static void acpi_device_del(struct acpi_device *device)
1257 {
1258         mutex_lock(&acpi_device_lock);
1259         if (device->parent)
1260                 list_del(&device->node);
1261
1262         list_del(&device->wakeup_list);
1263         mutex_unlock(&acpi_device_lock);
1264
1265         acpi_power_add_remove_device(device, false);
1266         acpi_device_remove_files(device);
1267         if (device->remove)
1268                 device->remove(device);
1269
1270         device_del(&device->dev);
1271 }
1272
1273 static LIST_HEAD(acpi_device_del_list);
1274 static DEFINE_MUTEX(acpi_device_del_lock);
1275
1276 static void acpi_device_del_work_fn(struct work_struct *work_not_used)
1277 {
1278         for (;;) {
1279                 struct acpi_device *adev;
1280
1281                 mutex_lock(&acpi_device_del_lock);
1282
1283                 if (list_empty(&acpi_device_del_list)) {
1284                         mutex_unlock(&acpi_device_del_lock);
1285                         break;
1286                 }
1287                 adev = list_first_entry(&acpi_device_del_list,
1288                                         struct acpi_device, del_list);
1289                 list_del(&adev->del_list);
1290
1291                 mutex_unlock(&acpi_device_del_lock);
1292
1293                 acpi_device_del(adev);
1294                 /*
1295                  * Drop references to all power resources that might have been
1296                  * used by the device.
1297                  */
1298                 acpi_power_transition(adev, ACPI_STATE_D3_COLD);
1299                 put_device(&adev->dev);
1300         }
1301 }
1302
1303 /**
1304  * acpi_scan_drop_device - Drop an ACPI device object.
1305  * @handle: Handle of an ACPI namespace node, not used.
1306  * @context: Address of the ACPI device object to drop.
1307  *
1308  * This is invoked by acpi_ns_delete_node() during the removal of the ACPI
1309  * namespace node the device object pointed to by @context is attached to.
1310  *
1311  * The unregistration is carried out asynchronously to avoid running
1312  * acpi_device_del() under the ACPICA's namespace mutex and the list is used to
1313  * ensure the correct ordering (the device objects must be unregistered in the
1314  * same order in which the corresponding namespace nodes are deleted).
1315  */
1316 static void acpi_scan_drop_device(acpi_handle handle, void *context)
1317 {
1318         static DECLARE_WORK(work, acpi_device_del_work_fn);
1319         struct acpi_device *adev = context;
1320
1321         mutex_lock(&acpi_device_del_lock);
1322
1323         /*
1324          * Use the ACPI hotplug workqueue which is ordered, so this work item
1325          * won't run after any hotplug work items submitted subsequently.  That
1326          * prevents attempts to register device objects identical to those being
1327          * deleted from happening concurrently (such attempts result from
1328          * hotplug events handled via the ACPI hotplug workqueue).  It also will
1329          * run after all of the work items submitted previosuly, which helps
1330          * those work items to ensure that they are not accessing stale device
1331          * objects.
1332          */
1333         if (list_empty(&acpi_device_del_list))
1334                 acpi_queue_hotplug_work(&work);
1335
1336         list_add_tail(&adev->del_list, &acpi_device_del_list);
1337         /* Make acpi_ns_validate_handle() return NULL for this handle. */
1338         adev->handle = INVALID_ACPI_HANDLE;
1339
1340         mutex_unlock(&acpi_device_del_lock);
1341 }
1342
1343 static int acpi_get_device_data(acpi_handle handle, struct acpi_device **device,
1344                                 void (*callback)(void *))
1345 {
1346         acpi_status status;
1347
1348         if (!device)
1349                 return -EINVAL;
1350
1351         status = acpi_get_data_full(handle, acpi_scan_drop_device,
1352                                     (void **)device, callback);
1353         if (ACPI_FAILURE(status) || !*device) {
1354                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No context for object [%p]\n",
1355                                   handle));
1356                 return -ENODEV;
1357         }
1358         return 0;
1359 }
1360
1361 int acpi_bus_get_device(acpi_handle handle, struct acpi_device **device)
1362 {
1363         return acpi_get_device_data(handle, device, NULL);
1364 }
1365 EXPORT_SYMBOL(acpi_bus_get_device);
1366
1367 static void get_acpi_device(void *dev)
1368 {
1369         if (dev)
1370                 get_device(&((struct acpi_device *)dev)->dev);
1371 }
1372
1373 struct acpi_device *acpi_bus_get_acpi_device(acpi_handle handle)
1374 {
1375         struct acpi_device *adev = NULL;
1376
1377         acpi_get_device_data(handle, &adev, get_acpi_device);
1378         return adev;
1379 }
1380
1381 void acpi_bus_put_acpi_device(struct acpi_device *adev)
1382 {
1383         put_device(&adev->dev);
1384 }
1385
1386 int acpi_device_add(struct acpi_device *device,
1387                     void (*release)(struct device *))
1388 {
1389         int result;
1390         struct acpi_device_bus_id *acpi_device_bus_id, *new_bus_id;
1391         int found = 0;
1392
1393         if (device->handle) {
1394                 acpi_status status;
1395
1396                 status = acpi_attach_data(device->handle, acpi_scan_drop_device,
1397                                           device);
1398                 if (ACPI_FAILURE(status)) {
1399                         acpi_handle_err(device->handle,
1400                                         "Unable to attach device data\n");
1401                         return -ENODEV;
1402                 }
1403         }
1404
1405         /*
1406          * Linkage
1407          * -------
1408          * Link this device to its parent and siblings.
1409          */
1410         INIT_LIST_HEAD(&device->children);
1411         INIT_LIST_HEAD(&device->node);
1412         INIT_LIST_HEAD(&device->wakeup_list);
1413         INIT_LIST_HEAD(&device->physical_node_list);
1414         INIT_LIST_HEAD(&device->del_list);
1415         mutex_init(&device->physical_node_lock);
1416
1417         new_bus_id = kzalloc(sizeof(struct acpi_device_bus_id), GFP_KERNEL);
1418         if (!new_bus_id) {
1419                 pr_err(PREFIX "Memory allocation error\n");
1420                 result = -ENOMEM;
1421                 goto err_detach;
1422         }
1423
1424         mutex_lock(&acpi_device_lock);
1425         /*
1426          * Find suitable bus_id and instance number in acpi_bus_id_list
1427          * If failed, create one and link it into acpi_bus_id_list
1428          */
1429         list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
1430                 if (!strcmp(acpi_device_bus_id->bus_id,
1431                             acpi_device_hid(device))) {
1432                         acpi_device_bus_id->instance_no++;
1433                         found = 1;
1434                         kfree(new_bus_id);
1435                         break;
1436                 }
1437         }
1438         if (!found) {
1439                 acpi_device_bus_id = new_bus_id;
1440                 strcpy(acpi_device_bus_id->bus_id, acpi_device_hid(device));
1441                 acpi_device_bus_id->instance_no = 0;
1442                 list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
1443         }
1444         dev_set_name(&device->dev, "%s:%02x", acpi_device_bus_id->bus_id, acpi_device_bus_id->instance_no);
1445
1446         if (device->parent)
1447                 list_add_tail(&device->node, &device->parent->children);
1448
1449         if (device->wakeup.flags.valid)
1450                 list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);
1451         mutex_unlock(&acpi_device_lock);
1452
1453         if (device->parent)
1454                 device->dev.parent = &device->parent->dev;
1455         device->dev.bus = &acpi_bus_type;
1456         device->dev.release = release;
1457         result = device_add(&device->dev);
1458         if (result) {
1459                 dev_err(&device->dev, "Error registering device\n");
1460                 goto err;
1461         }
1462
1463         result = acpi_device_setup_files(device);
1464         if (result)
1465                 printk(KERN_ERR PREFIX "Error creating sysfs interface for device %s\n",
1466                        dev_name(&device->dev));
1467
1468         return 0;
1469
1470  err:
1471         mutex_lock(&acpi_device_lock);
1472         if (device->parent)
1473                 list_del(&device->node);
1474         list_del(&device->wakeup_list);
1475         mutex_unlock(&acpi_device_lock);
1476
1477  err_detach:
1478         acpi_detach_data(device->handle, acpi_scan_drop_device);
1479         return result;
1480 }
1481
1482 struct acpi_device *acpi_get_next_child(struct device *dev,
1483                                         struct acpi_device *child)
1484 {
1485         struct acpi_device *adev = ACPI_COMPANION(dev);
1486         struct list_head *head, *next;
1487
1488         if (!adev)
1489                 return NULL;
1490
1491         head = &adev->children;
1492         if (list_empty(head))
1493                 return NULL;
1494
1495         if (!child)
1496                 return list_first_entry(head, struct acpi_device, node);
1497
1498         next = child->node.next;
1499         return next == head ? NULL : list_entry(next, struct acpi_device, node);
1500 }
1501
1502 /* --------------------------------------------------------------------------
1503                                  Driver Management
1504    -------------------------------------------------------------------------- */
1505 /**
1506  * acpi_bus_register_driver - register a driver with the ACPI bus
1507  * @driver: driver being registered
1508  *
1509  * Registers a driver with the ACPI bus.  Searches the namespace for all
1510  * devices that match the driver's criteria and binds.  Returns zero for
1511  * success or a negative error status for failure.
1512  */
1513 int acpi_bus_register_driver(struct acpi_driver *driver)
1514 {
1515         int ret;
1516
1517         if (acpi_disabled)
1518                 return -ENODEV;
1519         driver->drv.name = driver->name;
1520         driver->drv.bus = &acpi_bus_type;
1521         driver->drv.owner = driver->owner;
1522
1523         ret = driver_register(&driver->drv);
1524         return ret;
1525 }
1526
1527 EXPORT_SYMBOL(acpi_bus_register_driver);
1528
1529 /**
1530  * acpi_bus_unregister_driver - unregisters a driver with the ACPI bus
1531  * @driver: driver to unregister
1532  *
1533  * Unregisters a driver with the ACPI bus.  Searches the namespace for all
1534  * devices that match the driver's criteria and unbinds.
1535  */
1536 void acpi_bus_unregister_driver(struct acpi_driver *driver)
1537 {
1538         driver_unregister(&driver->drv);
1539 }
1540
1541 EXPORT_SYMBOL(acpi_bus_unregister_driver);
1542
1543 /* --------------------------------------------------------------------------
1544                                  Device Enumeration
1545    -------------------------------------------------------------------------- */
1546 static struct acpi_device *acpi_bus_get_parent(acpi_handle handle)
1547 {
1548         struct acpi_device *device = NULL;
1549         acpi_status status;
1550
1551         /*
1552          * Fixed hardware devices do not appear in the namespace and do not
1553          * have handles, but we fabricate acpi_devices for them, so we have
1554          * to deal with them specially.
1555          */
1556         if (!handle)
1557                 return acpi_root;
1558
1559         do {
1560                 status = acpi_get_parent(handle, &handle);
1561                 if (ACPI_FAILURE(status))
1562                         return status == AE_NULL_ENTRY ? NULL : acpi_root;
1563         } while (acpi_bus_get_device(handle, &device));
1564         return device;
1565 }
1566
1567 acpi_status
1568 acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
1569 {
1570         acpi_status status;
1571         acpi_handle tmp;
1572         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
1573         union acpi_object *obj;
1574
1575         status = acpi_get_handle(handle, "_EJD", &tmp);
1576         if (ACPI_FAILURE(status))
1577                 return status;
1578
1579         status = acpi_evaluate_object(handle, "_EJD", NULL, &buffer);
1580         if (ACPI_SUCCESS(status)) {
1581                 obj = buffer.pointer;
1582                 status = acpi_get_handle(ACPI_ROOT_OBJECT, obj->string.pointer,
1583                                          ejd);
1584                 kfree(buffer.pointer);
1585         }
1586         return status;
1587 }
1588 EXPORT_SYMBOL_GPL(acpi_bus_get_ejd);
1589
1590 static int acpi_bus_extract_wakeup_device_power_package(acpi_handle handle,
1591                                         struct acpi_device_wakeup *wakeup)
1592 {
1593         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1594         union acpi_object *package = NULL;
1595         union acpi_object *element = NULL;
1596         acpi_status status;
1597         int err = -ENODATA;
1598
1599         if (!wakeup)
1600                 return -EINVAL;
1601
1602         INIT_LIST_HEAD(&wakeup->resources);
1603
1604         /* _PRW */
1605         status = acpi_evaluate_object(handle, "_PRW", NULL, &buffer);
1606         if (ACPI_FAILURE(status)) {
1607                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRW"));
1608                 return err;
1609         }
1610
1611         package = (union acpi_object *)buffer.pointer;
1612
1613         if (!package || package->package.count < 2)
1614                 goto out;
1615
1616         element = &(package->package.elements[0]);
1617         if (!element)
1618                 goto out;
1619
1620         if (element->type == ACPI_TYPE_PACKAGE) {
1621                 if ((element->package.count < 2) ||
1622                     (element->package.elements[0].type !=
1623                      ACPI_TYPE_LOCAL_REFERENCE)
1624                     || (element->package.elements[1].type != ACPI_TYPE_INTEGER))
1625                         goto out;
1626
1627                 wakeup->gpe_device =
1628                     element->package.elements[0].reference.handle;
1629                 wakeup->gpe_number =
1630                     (u32) element->package.elements[1].integer.value;
1631         } else if (element->type == ACPI_TYPE_INTEGER) {
1632                 wakeup->gpe_device = NULL;
1633                 wakeup->gpe_number = element->integer.value;
1634         } else {
1635                 goto out;
1636         }
1637
1638         element = &(package->package.elements[1]);
1639         if (element->type != ACPI_TYPE_INTEGER)
1640                 goto out;
1641
1642         wakeup->sleep_state = element->integer.value;
1643
1644         err = acpi_extract_power_resources(package, 2, &wakeup->resources);
1645         if (err)
1646                 goto out;
1647
1648         if (!list_empty(&wakeup->resources)) {
1649                 int sleep_state;
1650
1651                 err = acpi_power_wakeup_list_init(&wakeup->resources,
1652                                                   &sleep_state);
1653                 if (err) {
1654                         acpi_handle_warn(handle, "Retrieving current states "
1655                                          "of wakeup power resources failed\n");
1656                         acpi_power_resources_list_free(&wakeup->resources);
1657                         goto out;
1658                 }
1659                 if (sleep_state < wakeup->sleep_state) {
1660                         acpi_handle_warn(handle, "Overriding _PRW sleep state "
1661                                          "(S%d) by S%d from power resources\n",
1662                                          (int)wakeup->sleep_state, sleep_state);
1663                         wakeup->sleep_state = sleep_state;
1664                 }
1665         }
1666
1667  out:
1668         kfree(buffer.pointer);
1669         return err;
1670 }
1671
1672 static void acpi_wakeup_gpe_init(struct acpi_device *device)
1673 {
1674         struct acpi_device_id button_device_ids[] = {
1675                 {"PNP0C0C", 0},
1676                 {"PNP0C0D", 0},
1677                 {"PNP0C0E", 0},
1678                 {"", 0},
1679         };
1680         struct acpi_device_wakeup *wakeup = &device->wakeup;
1681         acpi_status status;
1682         acpi_event_status event_status;
1683
1684         wakeup->flags.notifier_present = 0;
1685
1686         /* Power button, Lid switch always enable wakeup */
1687         if (!acpi_match_device_ids(device, button_device_ids)) {
1688                 wakeup->flags.run_wake = 1;
1689                 if (!acpi_match_device_ids(device, &button_device_ids[1])) {
1690                         /* Do not use Lid/sleep button for S5 wakeup */
1691                         if (wakeup->sleep_state == ACPI_STATE_S5)
1692                                 wakeup->sleep_state = ACPI_STATE_S4;
1693                 }
1694                 acpi_mark_gpe_for_wake(wakeup->gpe_device, wakeup->gpe_number);
1695                 device_set_wakeup_capable(&device->dev, true);
1696                 return;
1697         }
1698
1699         acpi_setup_gpe_for_wake(device->handle, wakeup->gpe_device,
1700                                 wakeup->gpe_number);
1701         status = acpi_get_gpe_status(wakeup->gpe_device, wakeup->gpe_number,
1702                                      &event_status);
1703         if (ACPI_FAILURE(status))
1704                 return;
1705
1706         wakeup->flags.run_wake = !!(event_status & ACPI_EVENT_FLAG_HAS_HANDLER);
1707 }
1708
1709 static void acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
1710 {
1711         int err;
1712
1713         /* Presence of _PRW indicates wake capable */
1714         if (!acpi_has_method(device->handle, "_PRW"))
1715                 return;
1716
1717         err = acpi_bus_extract_wakeup_device_power_package(device->handle,
1718                                                            &device->wakeup);
1719         if (err) {
1720                 dev_err(&device->dev, "_PRW evaluation error: %d\n", err);
1721                 return;
1722         }
1723
1724         device->wakeup.flags.valid = 1;
1725         device->wakeup.prepare_count = 0;
1726         acpi_wakeup_gpe_init(device);
1727         /* Call _PSW/_DSW object to disable its ability to wake the sleeping
1728          * system for the ACPI device with the _PRW object.
1729          * The _PSW object is depreciated in ACPI 3.0 and is replaced by _DSW.
1730          * So it is necessary to call _DSW object first. Only when it is not
1731          * present will the _PSW object used.
1732          */
1733         err = acpi_device_sleep_wake(device, 0, 0, 0);
1734         if (err)
1735                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1736                                 "error in _DSW or _PSW evaluation\n"));
1737 }
1738
1739 static void acpi_bus_init_power_state(struct acpi_device *device, int state)
1740 {
1741         struct acpi_device_power_state *ps = &device->power.states[state];
1742         char pathname[5] = { '_', 'P', 'R', '0' + state, '\0' };
1743         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1744         acpi_status status;
1745
1746         INIT_LIST_HEAD(&ps->resources);
1747
1748         /* Evaluate "_PRx" to get referenced power resources */
1749         status = acpi_evaluate_object(device->handle, pathname, NULL, &buffer);
1750         if (ACPI_SUCCESS(status)) {
1751                 union acpi_object *package = buffer.pointer;
1752
1753                 if (buffer.length && package
1754                     && package->type == ACPI_TYPE_PACKAGE
1755                     && package->package.count) {
1756                         int err = acpi_extract_power_resources(package, 0,
1757                                                                &ps->resources);
1758                         if (!err)
1759                                 device->power.flags.power_resources = 1;
1760                 }
1761                 ACPI_FREE(buffer.pointer);
1762         }
1763
1764         /* Evaluate "_PSx" to see if we can do explicit sets */
1765         pathname[2] = 'S';
1766         if (acpi_has_method(device->handle, pathname))
1767                 ps->flags.explicit_set = 1;
1768
1769         /*
1770          * State is valid if there are means to put the device into it.
1771          * D3hot is only valid if _PR3 present.
1772          */
1773         if (!list_empty(&ps->resources)
1774             || (ps->flags.explicit_set && state < ACPI_STATE_D3_HOT)) {
1775                 ps->flags.valid = 1;
1776                 ps->flags.os_accessible = 1;
1777         }
1778
1779         ps->power = -1;         /* Unknown - driver assigned */
1780         ps->latency = -1;       /* Unknown - driver assigned */
1781 }
1782
1783 static void acpi_bus_get_power_flags(struct acpi_device *device)
1784 {
1785         u32 i;
1786
1787         /* Presence of _PS0|_PR0 indicates 'power manageable' */
1788         if (!acpi_has_method(device->handle, "_PS0") &&
1789             !acpi_has_method(device->handle, "_PR0"))
1790                 return;
1791
1792         device->flags.power_manageable = 1;
1793
1794         /*
1795          * Power Management Flags
1796          */
1797         if (acpi_has_method(device->handle, "_PSC"))
1798                 device->power.flags.explicit_get = 1;
1799
1800         if (acpi_has_method(device->handle, "_IRC"))
1801                 device->power.flags.inrush_current = 1;
1802
1803         if (acpi_has_method(device->handle, "_DSW"))
1804                 device->power.flags.dsw_present = 1;
1805
1806         /*
1807          * Enumerate supported power management states
1808          */
1809         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++)
1810                 acpi_bus_init_power_state(device, i);
1811
1812         INIT_LIST_HEAD(&device->power.states[ACPI_STATE_D3_COLD].resources);
1813
1814         /* Set defaults for D0 and D3 states (always valid) */
1815         device->power.states[ACPI_STATE_D0].flags.valid = 1;
1816         device->power.states[ACPI_STATE_D0].power = 100;
1817         device->power.states[ACPI_STATE_D3_COLD].flags.valid = 1;
1818         device->power.states[ACPI_STATE_D3_COLD].power = 0;
1819
1820         /* Set D3cold's explicit_set flag if _PS3 exists. */
1821         if (device->power.states[ACPI_STATE_D3_HOT].flags.explicit_set)
1822                 device->power.states[ACPI_STATE_D3_COLD].flags.explicit_set = 1;
1823
1824         /* Presence of _PS3 or _PRx means we can put the device into D3 cold */
1825         if (device->power.states[ACPI_STATE_D3_HOT].flags.explicit_set ||
1826                         device->power.flags.power_resources)
1827                 device->power.states[ACPI_STATE_D3_COLD].flags.os_accessible = 1;
1828
1829         if (acpi_bus_init_power(device))
1830                 device->flags.power_manageable = 0;
1831 }
1832
1833 static void acpi_bus_get_flags(struct acpi_device *device)
1834 {
1835         /* Presence of _STA indicates 'dynamic_status' */
1836         if (acpi_has_method(device->handle, "_STA"))
1837                 device->flags.dynamic_status = 1;
1838
1839         /* Presence of _RMV indicates 'removable' */
1840         if (acpi_has_method(device->handle, "_RMV"))
1841                 device->flags.removable = 1;
1842
1843         /* Presence of _EJD|_EJ0 indicates 'ejectable' */
1844         if (acpi_has_method(device->handle, "_EJD") ||
1845             acpi_has_method(device->handle, "_EJ0"))
1846                 device->flags.ejectable = 1;
1847 }
1848
1849 static void acpi_device_get_busid(struct acpi_device *device)
1850 {
1851         char bus_id[5] = { '?', 0 };
1852         struct acpi_buffer buffer = { sizeof(bus_id), bus_id };
1853         int i = 0;
1854
1855         /*
1856          * Bus ID
1857          * ------
1858          * The device's Bus ID is simply the object name.
1859          * TBD: Shouldn't this value be unique (within the ACPI namespace)?
1860          */
1861         if (ACPI_IS_ROOT_DEVICE(device)) {
1862                 strcpy(device->pnp.bus_id, "ACPI");
1863                 return;
1864         }
1865
1866         switch (device->device_type) {
1867         case ACPI_BUS_TYPE_POWER_BUTTON:
1868                 strcpy(device->pnp.bus_id, "PWRF");
1869                 break;
1870         case ACPI_BUS_TYPE_SLEEP_BUTTON:
1871                 strcpy(device->pnp.bus_id, "SLPF");
1872                 break;
1873         default:
1874                 acpi_get_name(device->handle, ACPI_SINGLE_NAME, &buffer);
1875                 /* Clean up trailing underscores (if any) */
1876                 for (i = 3; i > 1; i--) {
1877                         if (bus_id[i] == '_')
1878                                 bus_id[i] = '\0';
1879                         else
1880                                 break;
1881                 }
1882                 strcpy(device->pnp.bus_id, bus_id);
1883                 break;
1884         }
1885 }
1886
1887 /*
1888  * acpi_ata_match - see if an acpi object is an ATA device
1889  *
1890  * If an acpi object has one of the ACPI ATA methods defined,
1891  * then we can safely call it an ATA device.
1892  */
1893 bool acpi_ata_match(acpi_handle handle)
1894 {
1895         return acpi_has_method(handle, "_GTF") ||
1896                acpi_has_method(handle, "_GTM") ||
1897                acpi_has_method(handle, "_STM") ||
1898                acpi_has_method(handle, "_SDD");
1899 }
1900
1901 /*
1902  * acpi_bay_match - see if an acpi object is an ejectable driver bay
1903  *
1904  * If an acpi object is ejectable and has one of the ACPI ATA methods defined,
1905  * then we can safely call it an ejectable drive bay
1906  */
1907 bool acpi_bay_match(acpi_handle handle)
1908 {
1909         acpi_handle phandle;
1910
1911         if (!acpi_has_method(handle, "_EJ0"))
1912                 return false;
1913         if (acpi_ata_match(handle))
1914                 return true;
1915         if (ACPI_FAILURE(acpi_get_parent(handle, &phandle)))
1916                 return false;
1917
1918         return acpi_ata_match(phandle);
1919 }
1920
1921 bool acpi_device_is_battery(struct acpi_device *adev)
1922 {
1923         struct acpi_hardware_id *hwid;
1924
1925         list_for_each_entry(hwid, &adev->pnp.ids, list)
1926                 if (!strcmp("PNP0C0A", hwid->id))
1927                         return true;
1928
1929         return false;
1930 }
1931
1932 static bool is_ejectable_bay(struct acpi_device *adev)
1933 {
1934         acpi_handle handle = adev->handle;
1935
1936         if (acpi_has_method(handle, "_EJ0") && acpi_device_is_battery(adev))
1937                 return true;
1938
1939         return acpi_bay_match(handle);
1940 }
1941
1942 /*
1943  * acpi_dock_match - see if an acpi object has a _DCK method
1944  */
1945 bool acpi_dock_match(acpi_handle handle)
1946 {
1947         return acpi_has_method(handle, "_DCK");
1948 }
1949
1950 const char *acpi_device_hid(struct acpi_device *device)
1951 {
1952         struct acpi_hardware_id *hid;
1953
1954         if (list_empty(&device->pnp.ids))
1955                 return dummy_hid;
1956
1957         hid = list_first_entry(&device->pnp.ids, struct acpi_hardware_id, list);
1958         return hid->id;
1959 }
1960 EXPORT_SYMBOL(acpi_device_hid);
1961
1962 static void acpi_add_id(struct acpi_device_pnp *pnp, const char *dev_id)
1963 {
1964         struct acpi_hardware_id *id;
1965
1966         id = kmalloc(sizeof(*id), GFP_KERNEL);
1967         if (!id)
1968                 return;
1969
1970         id->id = kstrdup(dev_id, GFP_KERNEL);
1971         if (!id->id) {
1972                 kfree(id);
1973                 return;
1974         }
1975
1976         list_add_tail(&id->list, &pnp->ids);
1977         pnp->type.hardware_id = 1;
1978 }
1979
1980 /*
1981  * Old IBM workstations have a DSDT bug wherein the SMBus object
1982  * lacks the SMBUS01 HID and the methods do not have the necessary "_"
1983  * prefix.  Work around this.
1984  */
1985 static bool acpi_ibm_smbus_match(acpi_handle handle)
1986 {
1987         char node_name[ACPI_PATH_SEGMENT_LENGTH];
1988         struct acpi_buffer path = { sizeof(node_name), node_name };
1989
1990         if (!dmi_name_in_vendors("IBM"))
1991                 return false;
1992
1993         /* Look for SMBS object */
1994         if (ACPI_FAILURE(acpi_get_name(handle, ACPI_SINGLE_NAME, &path)) ||
1995             strcmp("SMBS", path.pointer))
1996                 return false;
1997
1998         /* Does it have the necessary (but misnamed) methods? */
1999         if (acpi_has_method(handle, "SBI") &&
2000             acpi_has_method(handle, "SBR") &&
2001             acpi_has_method(handle, "SBW"))
2002                 return true;
2003
2004         return false;
2005 }
2006
2007 static bool acpi_object_is_system_bus(acpi_handle handle)
2008 {
2009         acpi_handle tmp;
2010
2011         if (ACPI_SUCCESS(acpi_get_handle(NULL, "\\_SB", &tmp)) &&
2012             tmp == handle)
2013                 return true;
2014         if (ACPI_SUCCESS(acpi_get_handle(NULL, "\\_TZ", &tmp)) &&
2015             tmp == handle)
2016                 return true;
2017
2018         return false;
2019 }
2020
2021 static void acpi_set_pnp_ids(acpi_handle handle, struct acpi_device_pnp *pnp,
2022                                 int device_type)
2023 {
2024         acpi_status status;
2025         struct acpi_device_info *info;
2026         struct acpi_pnp_device_id_list *cid_list;
2027         int i;
2028
2029         switch (device_type) {
2030         case ACPI_BUS_TYPE_DEVICE:
2031                 if (handle == ACPI_ROOT_OBJECT) {
2032                         acpi_add_id(pnp, ACPI_SYSTEM_HID);
2033                         break;
2034                 }
2035
2036                 status = acpi_get_object_info(handle, &info);
2037                 if (ACPI_FAILURE(status)) {
2038                         pr_err(PREFIX "%s: Error reading device info\n",
2039                                         __func__);
2040                         return;
2041                 }
2042
2043                 if (info->valid & ACPI_VALID_HID) {
2044                         acpi_add_id(pnp, info->hardware_id.string);
2045                         pnp->type.platform_id = 1;
2046                 }
2047                 if (info->valid & ACPI_VALID_CID) {
2048                         cid_list = &info->compatible_id_list;
2049                         for (i = 0; i < cid_list->count; i++)
2050                                 acpi_add_id(pnp, cid_list->ids[i].string);
2051                 }
2052                 if (info->valid & ACPI_VALID_ADR) {
2053                         pnp->bus_address = info->address;
2054                         pnp->type.bus_address = 1;
2055                 }
2056                 if (info->valid & ACPI_VALID_UID)
2057                         pnp->unique_id = kstrdup(info->unique_id.string,
2058                                                         GFP_KERNEL);
2059
2060                 kfree(info);
2061
2062                 /*
2063                  * Some devices don't reliably have _HIDs & _CIDs, so add
2064                  * synthetic HIDs to make sure drivers can find them.
2065                  */
2066                 if (acpi_is_video_device(handle))
2067                         acpi_add_id(pnp, ACPI_VIDEO_HID);
2068                 else if (acpi_bay_match(handle))
2069                         acpi_add_id(pnp, ACPI_BAY_HID);
2070                 else if (acpi_dock_match(handle))
2071                         acpi_add_id(pnp, ACPI_DOCK_HID);
2072                 else if (acpi_ibm_smbus_match(handle))
2073                         acpi_add_id(pnp, ACPI_SMBUS_IBM_HID);
2074                 else if (list_empty(&pnp->ids) &&
2075                          acpi_object_is_system_bus(handle)) {
2076                         /* \_SB, \_TZ, LNXSYBUS */
2077                         acpi_add_id(pnp, ACPI_BUS_HID);
2078                         strcpy(pnp->device_name, ACPI_BUS_DEVICE_NAME);
2079                         strcpy(pnp->device_class, ACPI_BUS_CLASS);
2080                 }
2081
2082                 break;
2083         case ACPI_BUS_TYPE_POWER:
2084                 acpi_add_id(pnp, ACPI_POWER_HID);
2085                 break;
2086         case ACPI_BUS_TYPE_PROCESSOR:
2087                 acpi_add_id(pnp, ACPI_PROCESSOR_OBJECT_HID);
2088                 break;
2089         case ACPI_BUS_TYPE_THERMAL:
2090                 acpi_add_id(pnp, ACPI_THERMAL_HID);
2091                 break;
2092         case ACPI_BUS_TYPE_POWER_BUTTON:
2093                 acpi_add_id(pnp, ACPI_BUTTON_HID_POWERF);
2094                 break;
2095         case ACPI_BUS_TYPE_SLEEP_BUTTON:
2096                 acpi_add_id(pnp, ACPI_BUTTON_HID_SLEEPF);
2097                 break;
2098         }
2099 }
2100
2101 void acpi_free_pnp_ids(struct acpi_device_pnp *pnp)
2102 {
2103         struct acpi_hardware_id *id, *tmp;
2104
2105         list_for_each_entry_safe(id, tmp, &pnp->ids, list) {
2106                 kfree(id->id);
2107                 kfree(id);
2108         }
2109         kfree(pnp->unique_id);
2110 }
2111
2112 void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,
2113                              int type, unsigned long long sta)
2114 {
2115         INIT_LIST_HEAD(&device->pnp.ids);
2116         device->device_type = type;
2117         device->handle = handle;
2118         device->parent = acpi_bus_get_parent(handle);
2119         device->fwnode.type = FWNODE_ACPI;
2120         acpi_set_device_status(device, sta);
2121         acpi_device_get_busid(device);
2122         acpi_set_pnp_ids(handle, &device->pnp, type);
2123         acpi_init_properties(device);
2124         acpi_bus_get_flags(device);
2125         device->flags.match_driver = false;
2126         device->flags.initialized = true;
2127         device->flags.visited = false;
2128         device_initialize(&device->dev);
2129         dev_set_uevent_suppress(&device->dev, true);
2130 }
2131
2132 void acpi_device_add_finalize(struct acpi_device *device)
2133 {
2134         dev_set_uevent_suppress(&device->dev, false);
2135         kobject_uevent(&device->dev.kobj, KOBJ_ADD);
2136 }
2137
2138 static int acpi_add_single_object(struct acpi_device **child,
2139                                   acpi_handle handle, int type,
2140                                   unsigned long long sta)
2141 {
2142         int result;
2143         struct acpi_device *device;
2144         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
2145
2146         device = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
2147         if (!device) {
2148                 printk(KERN_ERR PREFIX "Memory allocation error\n");
2149                 return -ENOMEM;
2150         }
2151
2152         acpi_init_device_object(device, handle, type, sta);
2153         acpi_bus_get_power_flags(device);
2154         acpi_bus_get_wakeup_device_flags(device);
2155
2156         result = acpi_device_add(device, acpi_device_release);
2157         if (result) {
2158                 acpi_device_release(&device->dev);
2159                 return result;
2160         }
2161
2162         acpi_power_add_remove_device(device, true);
2163         acpi_device_add_finalize(device);
2164         acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
2165         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Added %s [%s] parent %s\n",
2166                 dev_name(&device->dev), (char *) buffer.pointer,
2167                 device->parent ? dev_name(&device->parent->dev) : "(null)"));
2168         kfree(buffer.pointer);
2169         *child = device;
2170         return 0;
2171 }
2172
2173 static int acpi_bus_type_and_status(acpi_handle handle, int *type,
2174                                     unsigned long long *sta)
2175 {
2176         acpi_status status;
2177         acpi_object_type acpi_type;
2178
2179         status = acpi_get_type(handle, &acpi_type);
2180         if (ACPI_FAILURE(status))
2181                 return -ENODEV;
2182
2183         switch (acpi_type) {
2184         case ACPI_TYPE_ANY:             /* for ACPI_ROOT_OBJECT */
2185         case ACPI_TYPE_DEVICE:
2186                 *type = ACPI_BUS_TYPE_DEVICE;
2187                 status = acpi_bus_get_status_handle(handle, sta);
2188                 if (ACPI_FAILURE(status))
2189                         return -ENODEV;
2190                 break;
2191         case ACPI_TYPE_PROCESSOR:
2192                 *type = ACPI_BUS_TYPE_PROCESSOR;
2193                 status = acpi_bus_get_status_handle(handle, sta);
2194                 if (ACPI_FAILURE(status))
2195                         return -ENODEV;
2196                 break;
2197         case ACPI_TYPE_THERMAL:
2198                 *type = ACPI_BUS_TYPE_THERMAL;
2199                 *sta = ACPI_STA_DEFAULT;
2200                 break;
2201         case ACPI_TYPE_POWER:
2202                 *type = ACPI_BUS_TYPE_POWER;
2203                 *sta = ACPI_STA_DEFAULT;
2204                 break;
2205         default:
2206                 return -ENODEV;
2207         }
2208
2209         return 0;
2210 }
2211
2212 bool acpi_device_is_present(struct acpi_device *adev)
2213 {
2214         if (adev->status.present || adev->status.functional)
2215                 return true;
2216
2217         adev->flags.initialized = false;
2218         return false;
2219 }
2220
2221 static bool acpi_scan_handler_matching(struct acpi_scan_handler *handler,
2222                                        char *idstr,
2223                                        const struct acpi_device_id **matchid)
2224 {
2225         const struct acpi_device_id *devid;
2226
2227         if (handler->match)
2228                 return handler->match(idstr, matchid);
2229
2230         for (devid = handler->ids; devid->id[0]; devid++)
2231                 if (!strcmp((char *)devid->id, idstr)) {
2232                         if (matchid)
2233                                 *matchid = devid;
2234
2235                         return true;
2236                 }
2237
2238         return false;
2239 }
2240
2241 static struct acpi_scan_handler *acpi_scan_match_handler(char *idstr,
2242                                         const struct acpi_device_id **matchid)
2243 {
2244         struct acpi_scan_handler *handler;
2245
2246         list_for_each_entry(handler, &acpi_scan_handlers_list, list_node)
2247                 if (acpi_scan_handler_matching(handler, idstr, matchid))
2248                         return handler;
2249
2250         return NULL;
2251 }
2252
2253 void acpi_scan_hotplug_enabled(struct acpi_hotplug_profile *hotplug, bool val)
2254 {
2255         if (!!hotplug->enabled == !!val)
2256                 return;
2257
2258         mutex_lock(&acpi_scan_lock);
2259
2260         hotplug->enabled = val;
2261
2262         mutex_unlock(&acpi_scan_lock);
2263 }
2264
2265 static void acpi_scan_init_hotplug(struct acpi_device *adev)
2266 {
2267         struct acpi_hardware_id *hwid;
2268
2269         if (acpi_dock_match(adev->handle) || is_ejectable_bay(adev)) {
2270                 acpi_dock_add(adev);
2271                 return;
2272         }
2273         list_for_each_entry(hwid, &adev->pnp.ids, list) {
2274                 struct acpi_scan_handler *handler;
2275
2276                 handler = acpi_scan_match_handler(hwid->id, NULL);
2277                 if (handler) {
2278                         adev->flags.hotplug_notify = true;
2279                         break;
2280                 }
2281         }
2282 }
2283
2284 static void acpi_device_dep_initialize(struct acpi_device *adev)
2285 {
2286         struct acpi_dep_data *dep;
2287         struct acpi_handle_list dep_devices;
2288         acpi_status status;
2289         int i;
2290
2291         if (!acpi_has_method(adev->handle, "_DEP"))
2292                 return;
2293
2294         status = acpi_evaluate_reference(adev->handle, "_DEP", NULL,
2295                                         &dep_devices);
2296         if (ACPI_FAILURE(status)) {
2297                 dev_dbg(&adev->dev, "Failed to evaluate _DEP.\n");
2298                 return;
2299         }
2300
2301         for (i = 0; i < dep_devices.count; i++) {
2302                 struct acpi_device_info *info;
2303                 int skip;
2304
2305                 status = acpi_get_object_info(dep_devices.handles[i], &info);
2306                 if (ACPI_FAILURE(status)) {
2307                         dev_dbg(&adev->dev, "Error reading _DEP device info\n");
2308                         continue;
2309                 }
2310
2311                 /*
2312                  * Skip the dependency of Windows System Power
2313                  * Management Controller
2314                  */
2315                 skip = info->valid & ACPI_VALID_HID &&
2316                         !strcmp(info->hardware_id.string, "INT3396");
2317
2318                 kfree(info);
2319
2320                 if (skip)
2321                         continue;
2322
2323                 dep = kzalloc(sizeof(struct acpi_dep_data), GFP_KERNEL);
2324                 if (!dep)
2325                         return;
2326
2327                 dep->master = dep_devices.handles[i];
2328                 dep->slave  = adev->handle;
2329                 adev->dep_unmet++;
2330
2331                 mutex_lock(&acpi_dep_list_lock);
2332                 list_add_tail(&dep->node , &acpi_dep_list);
2333                 mutex_unlock(&acpi_dep_list_lock);
2334         }
2335 }
2336
2337 static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl_not_used,
2338                                       void *not_used, void **return_value)
2339 {
2340         struct acpi_device *device = NULL;
2341         int type;
2342         unsigned long long sta;
2343         int result;
2344
2345         acpi_bus_get_device(handle, &device);
2346         if (device)
2347                 goto out;
2348
2349         result = acpi_bus_type_and_status(handle, &type, &sta);
2350         if (result)
2351                 return AE_OK;
2352
2353         if (type == ACPI_BUS_TYPE_POWER) {
2354                 acpi_add_power_resource(handle);
2355                 return AE_OK;
2356         }
2357
2358         acpi_add_single_object(&device, handle, type, sta);
2359         if (!device)
2360                 return AE_CTRL_DEPTH;
2361
2362         acpi_scan_init_hotplug(device);
2363         acpi_device_dep_initialize(device);
2364
2365  out:
2366         if (!*return_value)
2367                 *return_value = device;
2368
2369         return AE_OK;
2370 }
2371
2372 static int acpi_check_spi_i2c_slave(struct acpi_resource *ares, void *data)
2373 {
2374         bool *is_spi_i2c_slave_p = data;
2375
2376         if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
2377                 return 1;
2378
2379         /*
2380          * devices that are connected to UART still need to be enumerated to
2381          * platform bus
2382          */
2383         if (ares->data.common_serial_bus.type != ACPI_RESOURCE_SERIAL_TYPE_UART)
2384                 *is_spi_i2c_slave_p = true;
2385
2386          /* no need to do more checking */
2387         return -1;
2388 }
2389
2390 static void acpi_default_enumeration(struct acpi_device *device)
2391 {
2392         struct list_head resource_list;
2393         bool is_spi_i2c_slave = false;
2394
2395         /*
2396          * Do not enemerate SPI/I2C slaves as they will be enuerated by their
2397          * respective parents.
2398          */
2399         INIT_LIST_HEAD(&resource_list);
2400         acpi_dev_get_resources(device, &resource_list, acpi_check_spi_i2c_slave,
2401                                &is_spi_i2c_slave);
2402         acpi_dev_free_resource_list(&resource_list);
2403         if (!is_spi_i2c_slave)
2404                 acpi_create_platform_device(device);
2405 }
2406
2407 static const struct acpi_device_id generic_device_ids[] = {
2408         {"PRP0001", },
2409         {"", },
2410 };
2411
2412 static int acpi_generic_device_attach(struct acpi_device *adev,
2413                                       const struct acpi_device_id *not_used)
2414 {
2415         /*
2416          * Since PRP0001 is the only ID handled here, the test below can be
2417          * unconditional.
2418          */
2419         if (adev->data.of_compatible)
2420                 acpi_default_enumeration(adev);
2421
2422         return 1;
2423 }
2424
2425 static struct acpi_scan_handler generic_device_handler = {
2426         .ids = generic_device_ids,
2427         .attach = acpi_generic_device_attach,
2428 };
2429
2430 static int acpi_scan_attach_handler(struct acpi_device *device)
2431 {
2432         struct acpi_hardware_id *hwid;
2433         int ret = 0;
2434
2435         list_for_each_entry(hwid, &device->pnp.ids, list) {
2436                 const struct acpi_device_id *devid;
2437                 struct acpi_scan_handler *handler;
2438
2439                 handler = acpi_scan_match_handler(hwid->id, &devid);
2440                 if (handler) {
2441                         if (!handler->attach) {
2442                                 device->pnp.type.platform_id = 0;
2443                                 continue;
2444                         }
2445                         device->handler = handler;
2446                         ret = handler->attach(device, devid);
2447                         if (ret > 0)
2448                                 break;
2449
2450                         device->handler = NULL;
2451                         if (ret < 0)
2452                                 break;
2453                 }
2454         }
2455
2456         return ret;
2457 }
2458
2459 static void acpi_bus_attach(struct acpi_device *device)
2460 {
2461         struct acpi_device *child;
2462         acpi_handle ejd;
2463         int ret;
2464
2465         if (ACPI_SUCCESS(acpi_bus_get_ejd(device->handle, &ejd)))
2466                 register_dock_dependent_device(device, ejd);
2467
2468         acpi_bus_get_status(device);
2469         /* Skip devices that are not present. */
2470         if (!acpi_device_is_present(device)) {
2471                 device->flags.visited = false;
2472                 device->flags.power_manageable = 0;
2473                 return;
2474         }
2475         if (device->handler)
2476                 goto ok;
2477
2478         if (!device->flags.initialized) {
2479                 device->flags.power_manageable =
2480                         device->power.states[ACPI_STATE_D0].flags.valid;
2481                 if (acpi_bus_init_power(device))
2482                         device->flags.power_manageable = 0;
2483
2484                 device->flags.initialized = true;
2485         }
2486         device->flags.visited = false;
2487         ret = acpi_scan_attach_handler(device);
2488         if (ret < 0)
2489                 return;
2490
2491         device->flags.match_driver = true;
2492         if (!ret) {
2493                 ret = device_attach(&device->dev);
2494                 if (ret < 0)
2495                         return;
2496
2497                 if (!ret && device->pnp.type.platform_id)
2498                         acpi_default_enumeration(device);
2499         }
2500         device->flags.visited = true;
2501
2502  ok:
2503         list_for_each_entry(child, &device->children, node)
2504                 acpi_bus_attach(child);
2505
2506         if (device->handler && device->handler->hotplug.notify_online)
2507                 device->handler->hotplug.notify_online(device);
2508 }
2509
2510 void acpi_walk_dep_device_list(acpi_handle handle)
2511 {
2512         struct acpi_dep_data *dep, *tmp;
2513         struct acpi_device *adev;
2514
2515         mutex_lock(&acpi_dep_list_lock);
2516         list_for_each_entry_safe(dep, tmp, &acpi_dep_list, node) {
2517                 if (dep->master == handle) {
2518                         acpi_bus_get_device(dep->slave, &adev);
2519                         if (!adev)
2520                                 continue;
2521
2522                         adev->dep_unmet--;
2523                         if (!adev->dep_unmet)
2524                                 acpi_bus_attach(adev);
2525                         list_del(&dep->node);
2526                         kfree(dep);
2527                 }
2528         }
2529         mutex_unlock(&acpi_dep_list_lock);
2530 }
2531 EXPORT_SYMBOL_GPL(acpi_walk_dep_device_list);
2532
2533 /**
2534  * acpi_bus_scan - Add ACPI device node objects in a given namespace scope.
2535  * @handle: Root of the namespace scope to scan.
2536  *
2537  * Scan a given ACPI tree (probably recently hot-plugged) and create and add
2538  * found devices.
2539  *
2540  * If no devices were found, -ENODEV is returned, but it does not mean that
2541  * there has been a real error.  There just have been no suitable ACPI objects
2542  * in the table trunk from which the kernel could create a device and add an
2543  * appropriate driver.
2544  *
2545  * Must be called under acpi_scan_lock.
2546  */
2547 int acpi_bus_scan(acpi_handle handle)
2548 {
2549         void *device = NULL;
2550
2551         if (ACPI_SUCCESS(acpi_bus_check_add(handle, 0, NULL, &device)))
2552                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
2553                                     acpi_bus_check_add, NULL, NULL, &device);
2554
2555         if (device) {
2556                 acpi_bus_attach(device);
2557                 return 0;
2558         }
2559         return -ENODEV;
2560 }
2561 EXPORT_SYMBOL(acpi_bus_scan);
2562
2563 /**
2564  * acpi_bus_trim - Detach scan handlers and drivers from ACPI device objects.
2565  * @adev: Root of the ACPI namespace scope to walk.
2566  *
2567  * Must be called under acpi_scan_lock.
2568  */
2569 void acpi_bus_trim(struct acpi_device *adev)
2570 {
2571         struct acpi_scan_handler *handler = adev->handler;
2572         struct acpi_device *child;
2573
2574         list_for_each_entry_reverse(child, &adev->children, node)
2575                 acpi_bus_trim(child);
2576
2577         adev->flags.match_driver = false;
2578         if (handler) {
2579                 if (handler->detach)
2580                         handler->detach(adev);
2581
2582                 adev->handler = NULL;
2583         } else {
2584                 device_release_driver(&adev->dev);
2585         }
2586         /*
2587          * Most likely, the device is going away, so put it into D3cold before
2588          * that.
2589          */
2590         acpi_device_set_power(adev, ACPI_STATE_D3_COLD);
2591         adev->flags.initialized = false;
2592         adev->flags.visited = false;
2593 }
2594 EXPORT_SYMBOL_GPL(acpi_bus_trim);
2595
2596 static int acpi_bus_scan_fixed(void)
2597 {
2598         int result = 0;
2599
2600         /*
2601          * Enumerate all fixed-feature devices.
2602          */
2603         if (!(acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON)) {
2604                 struct acpi_device *device = NULL;
2605
2606                 result = acpi_add_single_object(&device, NULL,
2607                                                 ACPI_BUS_TYPE_POWER_BUTTON,
2608                                                 ACPI_STA_DEFAULT);
2609                 if (result)
2610                         return result;
2611
2612                 device->flags.match_driver = true;
2613                 result = device_attach(&device->dev);
2614                 if (result < 0)
2615                         return result;
2616
2617                 device_init_wakeup(&device->dev, true);
2618         }
2619
2620         if (!(acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON)) {
2621                 struct acpi_device *device = NULL;
2622
2623                 result = acpi_add_single_object(&device, NULL,
2624                                                 ACPI_BUS_TYPE_SLEEP_BUTTON,
2625                                                 ACPI_STA_DEFAULT);
2626                 if (result)
2627                         return result;
2628
2629                 device->flags.match_driver = true;
2630                 result = device_attach(&device->dev);
2631         }
2632
2633         return result < 0 ? result : 0;
2634 }
2635
2636 int __init acpi_scan_init(void)
2637 {
2638         int result;
2639
2640         result = bus_register(&acpi_bus_type);
2641         if (result) {
2642                 /* We don't want to quit even if we failed to add suspend/resume */
2643                 printk(KERN_ERR PREFIX "Could not register bus type\n");
2644         }
2645
2646         acpi_pci_root_init();
2647         acpi_pci_link_init();
2648         acpi_processor_init();
2649         acpi_lpss_init();
2650         acpi_apd_init();
2651         acpi_cmos_rtc_init();
2652         acpi_container_init();
2653         acpi_memory_hotplug_init();
2654         acpi_pnp_init();
2655         acpi_int340x_thermal_init();
2656
2657         acpi_scan_add_handler(&generic_device_handler);
2658
2659         mutex_lock(&acpi_scan_lock);
2660         /*
2661          * Enumerate devices in the ACPI namespace.
2662          */
2663         result = acpi_bus_scan(ACPI_ROOT_OBJECT);
2664         if (result)
2665                 goto out;
2666
2667         result = acpi_bus_get_device(ACPI_ROOT_OBJECT, &acpi_root);
2668         if (result)
2669                 goto out;
2670
2671         /* Fixed feature devices do not exist on HW-reduced platform */
2672         if (!acpi_gbl_reduced_hardware) {
2673                 result = acpi_bus_scan_fixed();
2674                 if (result) {
2675                         acpi_detach_data(acpi_root->handle,
2676                                          acpi_scan_drop_device);
2677                         acpi_device_del(acpi_root);
2678                         put_device(&acpi_root->dev);
2679                         goto out;
2680                 }
2681         }
2682
2683         acpi_update_all_gpes();
2684
2685  out:
2686         mutex_unlock(&acpi_scan_lock);
2687         return result;
2688 }