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 ACPI_DT_NAMESPACE_HID from the modalias below, 0 should
 139          * be returned if ACPI_DT_NAMESPACE_HID is the only ACPI/PNP ID in the
 140          * device's list.
 141          */
 142         count = 0;
 143         list_for_each_entry(id, &acpi_dev->pnp.ids, list)
 144                 if (strcmp(id->id, ACPI_DT_NAMESPACE_HID))
 145                         count++;
 146
 147         if (!count)
 148                 return 0;
 149
 150         len = snprintf(modalias, size, "acpi:");
 151         if (len <= 0)
 152                 return len;
 153
 154         size -= len;
 155
 156         list_for_each_entry(id, &acpi_dev->pnp.ids, list) {
 157                 if (!strcmp(id->id, ACPI_DT_NAMESPACE_HID))
 158                         continue;
 159
 160                 count = snprintf(&modalias[len], size, "%s:", id->id);
 161                 if (count < 0)
 162                         return -EINVAL;
 163
 164                 if (count >= size)
 165                         return -ENOMEM;
 166
 167                 len += count;
 168                 size -= count;
 169         }
 170         modalias[len] = '\0';
 171         return len;
 172 }
 173
 174 /**
 175  * create_of_modalias - Creates DT compatible string for modalias and uevent
 176  * @acpi_dev: ACPI device object.
 177  * @modalias: Buffer to print into.
 178  * @size: Size of the buffer.
 179  *
 180  * Expose DT compatible modalias as of:NnameTCcompatible.  This function should
 181  * only be called for devices having ACPI_DT_NAMESPACE_HID in their list of
 182  * ACPI/PNP IDs.
 183  */
 184 static int create_of_modalias(struct acpi_device *acpi_dev, char *modalias,
 185                               int size)
 186 {
 187         struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
 188         const union acpi_object *of_compatible, *obj;
 189         int len, count;
 190         int i, nval;
 191         char *c;
 192
 193         acpi_get_name(acpi_dev->handle, ACPI_SINGLE_NAME, &buf);
 194         /* DT strings are all in lower case */
 195         for (c = buf.pointer; *c != '\0'; c++)
 196                 *c = tolower(*c);
 197
 198         len = snprintf(modalias, size, "of:N%sT", (char *)buf.pointer);
 199         ACPI_FREE(buf.pointer);
 200
 201         if (len <= 0)
 202                 return len;
 203
 204         of_compatible = acpi_dev->data.of_compatible;
 205         if (of_compatible->type == ACPI_TYPE_PACKAGE) {
 206                 nval = of_compatible->package.count;
 207                 obj = of_compatible->package.elements;
 208         } else { /* Must be ACPI_TYPE_STRING. */
 209                 nval = 1;
 210                 obj = of_compatible;
 211         }
 212         for (i = 0; i < nval; i++, obj++) {
 213                 count = snprintf(&modalias[len], size, "C%s",
 214                                  obj->string.pointer);
 215                 if (count < 0)
 216                         return -EINVAL;
 217
 218                 if (count >= size)
 219                         return -ENOMEM;
 220
 221                 len += count;
 222                 size -= count;
 223         }
 224         modalias[len] = '\0';
 225         return len;
 226 }
 227
 228 /*
 229  * acpi_companion_match() - Can we match via ACPI companion device
 230  * @dev: Device in question
 231  *
 232  * Check if the given device has an ACPI companion and if that companion has
 233  * a valid list of PNP IDs, and if the device is the first (primary) physical
 234  * device associated with it.  Return the companion pointer if that's the case
 235  * or NULL otherwise.
 236  *
 237  * If multiple physical devices are attached to a single ACPI companion, we need
 238  * to be careful.  The usage scenario for this kind of relationship is that all
 239  * of the physical devices in question use resources provided by the ACPI
 240  * companion.  A typical case is an MFD device where all the sub-devices share
 241  * the parent's ACPI companion.  In such cases we can only allow the primary
 242  * (first) physical device to be matched with the help of the companion's PNP
 243  * IDs.
 244  *
 245  * Additional physical devices sharing the ACPI companion can still use
 246  * resources available from it but they will be matched normally using functions
 247  * provided by their bus types (and analogously for their modalias).
 248  */
 249 static struct acpi_device *acpi_companion_match(const struct device *dev)
 250 {
 251         struct acpi_device *adev;
 252         struct mutex *physical_node_lock;
 253
 254         adev = ACPI_COMPANION(dev);
 255         if (!adev)
 256                 return NULL;
 257
 258         if (list_empty(&adev->pnp.ids))
 259                 return NULL;
 260
 261         physical_node_lock = &adev->physical_node_lock;
 262         mutex_lock(physical_node_lock);
 263         if (list_empty(&adev->physical_node_list)) {
 264                 adev = NULL;
 265         } else {
 266                 const struct acpi_device_physical_node *node;
 267
 268                 node = list_first_entry(&adev->physical_node_list,
 269                                         struct acpi_device_physical_node, node);
 270                 if (node->dev != dev)
 271                         adev = NULL;
 272         }
 273         mutex_unlock(physical_node_lock);
 274
 275         return adev;
 276 }
 277
 278 static int __acpi_device_uevent_modalias(struct acpi_device *adev,
 279                                          struct kobj_uevent_env *env)
 280 {
 281         int len;
 282
 283         if (!adev)
 284                 return -ENODEV;
 285
 286         if (list_empty(&adev->pnp.ids))
 287                 return 0;
 288
 289         if (add_uevent_var(env, "MODALIAS="))
 290                 return -ENOMEM;
 291
 292         len = create_pnp_modalias(adev, &env->buf[env->buflen - 1],
 293                                   sizeof(env->buf) - env->buflen);
 294         if (len < 0)
 295                 return len;
 296
 297         env->buflen += len;
 298         if (!adev->data.of_compatible)
 299                 return 0;
 300
 301         if (len > 0 && add_uevent_var(env, "MODALIAS="))
 302                 return -ENOMEM;
 303
 304         len = create_of_modalias(adev, &env->buf[env->buflen - 1],
 305                                  sizeof(env->buf) - env->buflen);
 306         if (len < 0)
 307                 return len;
 308
 309         env->buflen += len;
 310
 311         return 0;
 312 }
 313
 314 /*
 315  * Creates uevent modalias field for ACPI enumerated devices.
 316  * Because the other buses does not support ACPI HIDs & CIDs.
 317  * e.g. for a device with hid:IBM0001 and cid:ACPI0001 you get:
 318  * "acpi:IBM0001:ACPI0001"
 319  */
 320 int acpi_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
 321 {
 322         return __acpi_device_uevent_modalias(acpi_companion_match(dev), env);
 323 }
 324 EXPORT_SYMBOL_GPL(acpi_device_uevent_modalias);
 325
 326 static int __acpi_device_modalias(struct acpi_device *adev, char *buf, int size)
 327 {
 328         int len, count;
 329
 330         if (!adev)
 331                 return -ENODEV;
 332
 333         if (list_empty(&adev->pnp.ids))
 334                 return 0;
 335
 336         len = create_pnp_modalias(adev, buf, size - 1);
 337         if (len < 0) {
 338                 return len;
 339         } else if (len > 0) {
 340                 buf[len++] = '\n';
 341                 size -= len;
 342         }
 343         if (!adev->data.of_compatible)
 344                 return len;
 345
 346         count = create_of_modalias(adev, buf + len, size - 1);
 347         if (count < 0) {
 348                 return count;
 349         } else if (count > 0) {
 350                 len += count;
 351                 buf[len++] = '\n';
 352         }
 353
 354         return len;
 355 }
 356
 357 /*
 358  * Creates modalias sysfs attribute for ACPI enumerated devices.
 359  * Because the other buses does not support ACPI HIDs & CIDs.
 360  * e.g. for a device with hid:IBM0001 and cid:ACPI0001 you get:
 361  * "acpi:IBM0001:ACPI0001"
 362  */
 363 int acpi_device_modalias(struct device *dev, char *buf, int size)
 364 {
 365         return __acpi_device_modalias(acpi_companion_match(dev), buf, size);
 366 }
 367 EXPORT_SYMBOL_GPL(acpi_device_modalias);
 368
 369 static ssize_t
 370 acpi_device_modalias_show(struct device *dev, struct device_attribute *attr, char *buf) {
 371         return __acpi_device_modalias(to_acpi_device(dev), buf, 1024);
 372 }
 373 static DEVICE_ATTR(modalias, 0444, acpi_device_modalias_show, NULL);
 374
 375 bool acpi_scan_is_offline(struct acpi_device *adev, bool uevent)
 376 {
 377         struct acpi_device_physical_node *pn;
 378         bool offline = true;
 379
 380         /*
 381          * acpi_container_offline() calls this for all of the container's
 382          * children under the container's physical_node_lock lock.
 383          */
 384         mutex_lock_nested(&adev->physical_node_lock, SINGLE_DEPTH_NESTING);
 385
 386         list_for_each_entry(pn, &adev->physical_node_list, node)
 387                 if (device_supports_offline(pn->dev) && !pn->dev->offline) {
 388                         if (uevent)
 389                                 kobject_uevent(&pn->dev->kobj, KOBJ_CHANGE);
 390
 391                         offline = false;
 392                         break;
 393                 }
 394
 395         mutex_unlock(&adev->physical_node_lock);
 396         return offline;
 397 }
 398
 399 static acpi_status acpi_bus_offline(acpi_handle handle, u32 lvl, void *data,
 400                                     void **ret_p)
 401 {
 402         struct acpi_device *device = NULL;
 403         struct acpi_device_physical_node *pn;
 404         bool second_pass = (bool)data;
 405         acpi_status status = AE_OK;
 406
 407         if (acpi_bus_get_device(handle, &device))
 408                 return AE_OK;
 409
 410         if (device->handler && !device->handler->hotplug.enabled) {
 411                 *ret_p = &device->dev;
 412                 return AE_SUPPORT;
 413         }
 414
 415         mutex_lock(&device->physical_node_lock);
 416
 417         list_for_each_entry(pn, &device->physical_node_list, node) {
 418                 int ret;
 419
 420                 if (second_pass) {
 421                         /* Skip devices offlined by the first pass. */
 422                         if (pn->put_online)
 423                                 continue;
 424                 } else {
 425                         pn->put_online = false;
 426                 }
 427                 ret = device_offline(pn->dev);
 428                 if (acpi_force_hot_remove)
 429                         continue;
 430
 431                 if (ret >= 0) {
 432                         pn->put_online = !ret;
 433                 } else {
 434                         *ret_p = pn->dev;
 435                         if (second_pass) {
 436                                 status = AE_ERROR;
 437                                 break;
 438                         }
 439                 }
 440         }
 441
 442         mutex_unlock(&device->physical_node_lock);
 443
 444         return status;
 445 }
 446
 447 static acpi_status acpi_bus_online(acpi_handle handle, u32 lvl, void *data,
 448                                    void **ret_p)
 449 {
 450         struct acpi_device *device = NULL;
 451         struct acpi_device_physical_node *pn;
 452
 453         if (acpi_bus_get_device(handle, &device))
 454                 return AE_OK;
 455
 456         mutex_lock(&device->physical_node_lock);
 457
 458         list_for_each_entry(pn, &device->physical_node_list, node)
 459                 if (pn->put_online) {
 460                         device_online(pn->dev);
 461                         pn->put_online = false;
 462                 }
 463
 464         mutex_unlock(&device->physical_node_lock);
 465
 466         return AE_OK;
 467 }
 468
 469 static int acpi_scan_try_to_offline(struct acpi_device *device)
 470 {
 471         acpi_handle handle = device->handle;
 472         struct device *errdev = NULL;
 473         acpi_status status;
 474
 475         /*
 476          * Carry out two passes here and ignore errors in the first pass,
 477          * because if the devices in question are memory blocks and
 478          * CONFIG_MEMCG is set, one of the blocks may hold data structures
 479          * that the other blocks depend on, but it is not known in advance which
 480          * block holds them.
 481          *
 482          * If the first pass is successful, the second one isn't needed, though.
 483          */
 484         status = acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
 485                                      NULL, acpi_bus_offline, (void *)false,
 486                                      (void **)&errdev);
 487         if (status == AE_SUPPORT) {
 488                 dev_warn(errdev, "Offline disabled.\n");
 489                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
 490                                     acpi_bus_online, NULL, NULL, NULL);
 491                 return -EPERM;
 492         }
 493         acpi_bus_offline(handle, 0, (void *)false, (void **)&errdev);
 494         if (errdev) {
 495                 errdev = NULL;
 496                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
 497                                     NULL, acpi_bus_offline, (void *)true,
 498                                     (void **)&errdev);
 499                 if (!errdev || acpi_force_hot_remove)
 500                         acpi_bus_offline(handle, 0, (void *)true,
 501                                          (void **)&errdev);
 502
 503                 if (errdev && !acpi_force_hot_remove) {
 504                         dev_warn(errdev, "Offline failed.\n");
 505                         acpi_bus_online(handle, 0, NULL, NULL);
 506                         acpi_walk_namespace(ACPI_TYPE_ANY, handle,
 507                                             ACPI_UINT32_MAX, acpi_bus_online,
 508                                             NULL, NULL, NULL);
 509                         return -EBUSY;
 510                 }
 511         }
 512         return 0;
 513 }
 514
 515 static int acpi_scan_hot_remove(struct acpi_device *device)
 516 {
 517         acpi_handle handle = device->handle;
 518         unsigned long long sta;
 519         acpi_status status;
 520
 521         if (device->handler && device->handler->hotplug.demand_offline
 522             && !acpi_force_hot_remove) {
 523                 if (!acpi_scan_is_offline(device, true))
 524                         return -EBUSY;
 525         } else {
 526                 int error = acpi_scan_try_to_offline(device);
 527                 if (error)
 528                         return error;
 529         }
 530
 531         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 532                 "Hot-removing device %s...\n", dev_name(&device->dev)));
 533
 534         acpi_bus_trim(device);
 535
 536         acpi_evaluate_lck(handle, 0);
 537         /*
 538          * TBD: _EJD support.
 539          */
 540         status = acpi_evaluate_ej0(handle);
 541         if (status == AE_NOT_FOUND)
 542                 return -ENODEV;
 543         else if (ACPI_FAILURE(status))
 544                 return -EIO;
 545
 546         /*
 547          * Verify if eject was indeed successful.  If not, log an error
 548          * message.  No need to call _OST since _EJ0 call was made OK.
 549          */
 550         status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
 551         if (ACPI_FAILURE(status)) {
 552                 acpi_handle_warn(handle,
 553                         "Status check after eject failed (0x%x)\n", status);
 554         } else if (sta & ACPI_STA_DEVICE_ENABLED) {
 555                 acpi_handle_warn(handle,
 556                         "Eject incomplete - status 0x%llx\n", sta);
 557         }
 558
 559         return 0;
 560 }
 561
 562 static int acpi_scan_device_not_present(struct acpi_device *adev)
 563 {
 564         if (!acpi_device_enumerated(adev)) {
 565                 dev_warn(&adev->dev, "Still not present\n");
 566                 return -EALREADY;
 567         }
 568         acpi_bus_trim(adev);
 569         return 0;
 570 }
 571
 572 static int acpi_scan_device_check(struct acpi_device *adev)
 573 {
 574         int error;
 575
 576         acpi_bus_get_status(adev);
 577         if (adev->status.present || adev->status.functional) {
 578                 /*
 579                  * This function is only called for device objects for which
 580                  * matching scan handlers exist.  The only situation in which
 581                  * the scan handler is not attached to this device object yet
 582                  * is when the device has just appeared (either it wasn't
 583                  * present at all before or it was removed and then added
 584                  * again).
 585                  */
 586                 if (adev->handler) {
 587                         dev_warn(&adev->dev, "Already enumerated\n");
 588                         return -EALREADY;
 589                 }
 590                 error = acpi_bus_scan(adev->handle);
 591                 if (error) {
 592                         dev_warn(&adev->dev, "Namespace scan failure\n");
 593                         return error;
 594                 }
 595                 if (!adev->handler) {
 596                         dev_warn(&adev->dev, "Enumeration failure\n");
 597                         error = -ENODEV;
 598                 }
 599         } else {
 600                 error = acpi_scan_device_not_present(adev);
 601         }
 602         return error;
 603 }
 604
 605 static int acpi_scan_bus_check(struct acpi_device *adev)
 606 {
 607         struct acpi_scan_handler *handler = adev->handler;
 608         struct acpi_device *child;
 609         int error;
 610
 611         acpi_bus_get_status(adev);
 612         if (!(adev->status.present || adev->status.functional)) {
 613                 acpi_scan_device_not_present(adev);
 614                 return 0;
 615         }
 616         if (handler && handler->hotplug.scan_dependent)
 617                 return handler->hotplug.scan_dependent(adev);
 618
 619         error = acpi_bus_scan(adev->handle);
 620         if (error) {
 621                 dev_warn(&adev->dev, "Namespace scan failure\n");
 622                 return error;
 623         }
 624         list_for_each_entry(child, &adev->children, node) {
 625                 error = acpi_scan_bus_check(child);
 626                 if (error)
 627                         return error;
 628         }
 629         return 0;
 630 }
 631
 632 static int acpi_generic_hotplug_event(struct acpi_device *adev, u32 type)
 633 {
 634         switch (type) {
 635         case ACPI_NOTIFY_BUS_CHECK:
 636                 return acpi_scan_bus_check(adev);
 637         case ACPI_NOTIFY_DEVICE_CHECK:
 638                 return acpi_scan_device_check(adev);
 639         case ACPI_NOTIFY_EJECT_REQUEST:
 640         case ACPI_OST_EC_OSPM_EJECT:
 641                 if (adev->handler && !adev->handler->hotplug.enabled) {
 642                         dev_info(&adev->dev, "Eject disabled\n");
 643                         return -EPERM;
 644                 }
 645                 acpi_evaluate_ost(adev->handle, ACPI_NOTIFY_EJECT_REQUEST,
 646                                   ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
 647                 return acpi_scan_hot_remove(adev);
 648         }
 649         return -EINVAL;
 650 }
 651
 652 void acpi_device_hotplug(struct acpi_device *adev, u32 src)
 653 {
 654         u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
 655         int error = -ENODEV;
 656
 657         lock_device_hotplug();
 658         mutex_lock(&acpi_scan_lock);
 659
 660         /*
 661          * The device object's ACPI handle cannot become invalid as long as we
 662          * are holding acpi_scan_lock, but it might have become invalid before
 663          * that lock was acquired.
 664          */
 665         if (adev->handle == INVALID_ACPI_HANDLE)
 666                 goto err_out;
 667
 668         if (adev->flags.is_dock_station) {
 669                 error = dock_notify(adev, src);
 670         } else if (adev->flags.hotplug_notify) {
 671                 error = acpi_generic_hotplug_event(adev, src);
 672                 if (error == -EPERM) {
 673                         ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
 674                         goto err_out;
 675                 }
 676         } else {
 677                 int (*notify)(struct acpi_device *, u32);
 678
 679                 acpi_lock_hp_context();
 680                 notify = adev->hp ? adev->hp->notify : NULL;
 681                 acpi_unlock_hp_context();
 682                 /*
 683                  * There may be additional notify handlers for device objects
 684                  * without the .event() callback, so ignore them here.
 685                  */
 686                 if (notify)
 687                         error = notify(adev, src);
 688                 else
 689                         goto out;
 690         }
 691         if (!error)
 692                 ost_code = ACPI_OST_SC_SUCCESS;
 693
 694  err_out:
 695         acpi_evaluate_ost(adev->handle, src, ost_code, NULL);
 696
 697  out:
 698         acpi_bus_put_acpi_device(adev);
 699         mutex_unlock(&acpi_scan_lock);
 700         unlock_device_hotplug();
 701 }
 702
 703 static ssize_t real_power_state_show(struct device *dev,
 704                                      struct device_attribute *attr, char *buf)
 705 {
 706         struct acpi_device *adev = to_acpi_device(dev);
 707         int state;
 708         int ret;
 709
 710         ret = acpi_device_get_power(adev, &state);
 711         if (ret)
 712                 return ret;
 713
 714         return sprintf(buf, "%s\n", acpi_power_state_string(state));
 715 }
 716
 717 static DEVICE_ATTR(real_power_state, 0444, real_power_state_show, NULL);
 718
 719 static ssize_t power_state_show(struct device *dev,
 720                                 struct device_attribute *attr, char *buf)
 721 {
 722         struct acpi_device *adev = to_acpi_device(dev);
 723
 724         return sprintf(buf, "%s\n", acpi_power_state_string(adev->power.state));
 725 }
 726
 727 static DEVICE_ATTR(power_state, 0444, power_state_show, NULL);
 728
 729 static ssize_t
 730 acpi_eject_store(struct device *d, struct device_attribute *attr,
 731                 const char *buf, size_t count)
 732 {
 733         struct acpi_device *acpi_device = to_acpi_device(d);
 734         acpi_object_type not_used;
 735         acpi_status status;
 736
 737         if (!count || buf[0] != '1')
 738                 return -EINVAL;
 739
 740         if ((!acpi_device->handler || !acpi_device->handler->hotplug.enabled)
 741             && !acpi_device->driver)
 742                 return -ENODEV;
 743
 744         status = acpi_get_type(acpi_device->handle, &not_used);
 745         if (ACPI_FAILURE(status) || !acpi_device->flags.ejectable)
 746                 return -ENODEV;
 747
 748         get_device(&acpi_device->dev);
 749         status = acpi_hotplug_schedule(acpi_device, ACPI_OST_EC_OSPM_EJECT);
 750         if (ACPI_SUCCESS(status))
 751                 return count;
 752
 753         put_device(&acpi_device->dev);
 754         acpi_evaluate_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,
 755                           ACPI_OST_SC_NON_SPECIFIC_FAILURE, NULL);
 756         return status == AE_NO_MEMORY ? -ENOMEM : -EAGAIN;
 757 }
 758
 759 static DEVICE_ATTR(eject, 0200, NULL, acpi_eject_store);
 760
 761 static ssize_t
 762 acpi_device_hid_show(struct device *dev, struct device_attribute *attr, char *buf) {
 763         struct acpi_device *acpi_dev = to_acpi_device(dev);
 764
 765         return sprintf(buf, "%s\n", acpi_device_hid(acpi_dev));
 766 }
 767 static DEVICE_ATTR(hid, 0444, acpi_device_hid_show, NULL);
 768
 769 static ssize_t acpi_device_uid_show(struct device *dev,
 770                                     struct device_attribute *attr, char *buf)
 771 {
 772         struct acpi_device *acpi_dev = to_acpi_device(dev);
 773
 774         return sprintf(buf, "%s\n", acpi_dev->pnp.unique_id);
 775 }
 776 static DEVICE_ATTR(uid, 0444, acpi_device_uid_show, NULL);
 777
 778 static ssize_t acpi_device_adr_show(struct device *dev,
 779                                     struct device_attribute *attr, char *buf)
 780 {
 781         struct acpi_device *acpi_dev = to_acpi_device(dev);
 782
 783         return sprintf(buf, "0x%08x\n",
 784                        (unsigned int)(acpi_dev->pnp.bus_address));
 785 }
 786 static DEVICE_ATTR(adr, 0444, acpi_device_adr_show, NULL);
 787
 788 static ssize_t
 789 acpi_device_path_show(struct device *dev, struct device_attribute *attr, char *buf) {
 790         struct acpi_device *acpi_dev = to_acpi_device(dev);
 791         struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
 792         int result;
 793
 794         result = acpi_get_name(acpi_dev->handle, ACPI_FULL_PATHNAME, &path);
 795         if (result)
 796                 goto end;
 797
 798         result = sprintf(buf, "%s\n", (char*)path.pointer);
 799         kfree(path.pointer);
 800 end:
 801         return result;
 802 }
 803 static DEVICE_ATTR(path, 0444, acpi_device_path_show, NULL);
 804
 805 /* sysfs file that shows description text from the ACPI _STR method */
 806 static ssize_t description_show(struct device *dev,
 807                                 struct device_attribute *attr,
 808                                 char *buf) {
 809         struct acpi_device *acpi_dev = to_acpi_device(dev);
 810         int result;
 811
 812         if (acpi_dev->pnp.str_obj == NULL)
 813                 return 0;
 814
 815         /*
 816          * The _STR object contains a Unicode identifier for a device.
 817          * We need to convert to utf-8 so it can be displayed.
 818          */
 819         result = utf16s_to_utf8s(
 820                 (wchar_t *)acpi_dev->pnp.str_obj->buffer.pointer,
 821                 acpi_dev->pnp.str_obj->buffer.length,
 822                 UTF16_LITTLE_ENDIAN, buf,
 823                 PAGE_SIZE);
 824
 825         buf[result++] = '\n';
 826
 827         return result;
 828 }
 829 static DEVICE_ATTR(description, 0444, description_show, NULL);
 830
 831 static ssize_t
 832 acpi_device_sun_show(struct device *dev, struct device_attribute *attr,
 833                      char *buf) {
 834         struct acpi_device *acpi_dev = to_acpi_device(dev);
 835         acpi_status status;
 836         unsigned long long sun;
 837
 838         status = acpi_evaluate_integer(acpi_dev->handle, "_SUN", NULL, &sun);
 839         if (ACPI_FAILURE(status))
 840                 return -ENODEV;
 841
 842         return sprintf(buf, "%llu\n", sun);
 843 }
 844 static DEVICE_ATTR(sun, 0444, acpi_device_sun_show, NULL);
 845
 846 static ssize_t status_show(struct device *dev, struct device_attribute *attr,
 847                                 char *buf) {
 848         struct acpi_device *acpi_dev = to_acpi_device(dev);
 849         acpi_status status;
 850         unsigned long long sta;
 851
 852         status = acpi_evaluate_integer(acpi_dev->handle, "_STA", NULL, &sta);
 853         if (ACPI_FAILURE(status))
 854                 return -ENODEV;
 855
 856         return sprintf(buf, "%llu\n", sta);
 857 }
 858 static DEVICE_ATTR_RO(status);
 859
 860 static int acpi_device_setup_files(struct acpi_device *dev)
 861 {
 862         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
 863         acpi_status status;
 864         int result = 0;
 865
 866         /*
 867          * Devices gotten from FADT don't have a "path" attribute
 868          */
 869         if (dev->handle) {
 870                 result = device_create_file(&dev->dev, &dev_attr_path);
 871                 if (result)
 872                         goto end;
 873         }
 874
 875         if (!list_empty(&dev->pnp.ids)) {
 876                 result = device_create_file(&dev->dev, &dev_attr_hid);
 877                 if (result)
 878                         goto end;
 879
 880                 result = device_create_file(&dev->dev, &dev_attr_modalias);
 881                 if (result)
 882                         goto end;
 883         }
 884
 885         /*
 886          * If device has _STR, 'description' file is created
 887          */
 888         if (acpi_has_method(dev->handle, "_STR")) {
 889                 status = acpi_evaluate_object(dev->handle, "_STR",
 890                                         NULL, &buffer);
 891                 if (ACPI_FAILURE(status))
 892                         buffer.pointer = NULL;
 893                 dev->pnp.str_obj = buffer.pointer;
 894                 result = device_create_file(&dev->dev, &dev_attr_description);
 895                 if (result)
 896                         goto end;
 897         }
 898
 899         if (dev->pnp.type.bus_address)
 900                 result = device_create_file(&dev->dev, &dev_attr_adr);
 901         if (dev->pnp.unique_id)
 902                 result = device_create_file(&dev->dev, &dev_attr_uid);
 903
 904         if (acpi_has_method(dev->handle, "_SUN")) {
 905                 result = device_create_file(&dev->dev, &dev_attr_sun);
 906                 if (result)
 907                         goto end;
 908         }
 909
 910         if (acpi_has_method(dev->handle, "_STA")) {
 911                 result = device_create_file(&dev->dev, &dev_attr_status);
 912                 if (result)
 913                         goto end;
 914         }
 915
 916         /*
 917          * If device has _EJ0, 'eject' file is created that is used to trigger
 918          * hot-removal function from userland.
 919          */
 920         if (acpi_has_method(dev->handle, "_EJ0")) {
 921                 result = device_create_file(&dev->dev, &dev_attr_eject);
 922                 if (result)
 923                         return result;
 924         }
 925
 926         if (dev->flags.power_manageable) {
 927                 result = device_create_file(&dev->dev, &dev_attr_power_state);
 928                 if (result)
 929                         return result;
 930
 931                 if (dev->power.flags.power_resources)
 932                         result = device_create_file(&dev->dev,
 933                                                     &dev_attr_real_power_state);
 934         }
 935
 936 end:
 937         return result;
 938 }
 939
 940 static void acpi_device_remove_files(struct acpi_device *dev)
 941 {
 942         if (dev->flags.power_manageable) {
 943                 device_remove_file(&dev->dev, &dev_attr_power_state);
 944                 if (dev->power.flags.power_resources)
 945                         device_remove_file(&dev->dev,
 946                                            &dev_attr_real_power_state);
 947         }
 948
 949         /*
 950          * If device has _STR, remove 'description' file
 951          */
 952         if (acpi_has_method(dev->handle, "_STR")) {
 953                 kfree(dev->pnp.str_obj);
 954                 device_remove_file(&dev->dev, &dev_attr_description);
 955         }
 956         /*
 957          * If device has _EJ0, remove 'eject' file.
 958          */
 959         if (acpi_has_method(dev->handle, "_EJ0"))
 960                 device_remove_file(&dev->dev, &dev_attr_eject);
 961
 962         if (acpi_has_method(dev->handle, "_SUN"))
 963                 device_remove_file(&dev->dev, &dev_attr_sun);
 964
 965         if (dev->pnp.unique_id)
 966                 device_remove_file(&dev->dev, &dev_attr_uid);
 967         if (dev->pnp.type.bus_address)
 968                 device_remove_file(&dev->dev, &dev_attr_adr);
 969         device_remove_file(&dev->dev, &dev_attr_modalias);
 970         device_remove_file(&dev->dev, &dev_attr_hid);
 971         if (acpi_has_method(dev->handle, "_STA"))
 972                 device_remove_file(&dev->dev, &dev_attr_status);
 973         if (dev->handle)
 974                 device_remove_file(&dev->dev, &dev_attr_path);
 975 }
 976 /* --------------------------------------------------------------------------
 977                         ACPI Bus operations
 978    -------------------------------------------------------------------------- */
 979
 980 /**
 981  * acpi_of_match_device - Match device object using the "compatible" property.
 982  * @adev: ACPI device object to match.
 983  * @of_match_table: List of device IDs to match against.
 984  *
 985  * If @dev has an ACPI companion which has ACPI_DT_NAMESPACE_HID in its list of
 986  * identifiers and a _DSD object with the "compatible" property, use that
 987  * property to match against the given list of identifiers.
 988  */
 989 static bool acpi_of_match_device(struct acpi_device *adev,
 990                                  const struct of_device_id *of_match_table)
 991 {
 992         const union acpi_object *of_compatible, *obj;
 993         int i, nval;
 994
 995         if (!adev)
 996                 return false;
 997
 998         of_compatible = adev->data.of_compatible;
 999         if (!of_match_table || !of_compatible)
1000                 return false;
1001
1002         if (of_compatible->type == ACPI_TYPE_PACKAGE) {
1003                 nval = of_compatible->package.count;
1004                 obj = of_compatible->package.elements;
1005         } else { /* Must be ACPI_TYPE_STRING. */
1006                 nval = 1;
1007                 obj = of_compatible;
1008         }
1009         /* Now we can look for the driver DT compatible strings */
1010         for (i = 0; i < nval; i++, obj++) {
1011                 const struct of_device_id *id;
1012
1013                 for (id = of_match_table; id->compatible[0]; id++)
1014                         if (!strcasecmp(obj->string.pointer, id->compatible))
1015                                 return true;
1016         }
1017
1018         return false;
1019 }
1020
1021 static const struct acpi_device_id *__acpi_match_device(
1022         struct acpi_device *device,
1023         const struct acpi_device_id *ids,
1024         const struct of_device_id *of_ids)
1025 {
1026         const struct acpi_device_id *id;
1027         struct acpi_hardware_id *hwid;
1028
1029         /*
1030          * If the device is not present, it is unnecessary to load device
1031          * driver for it.
1032          */
1033         if (!device || !device->status.present)
1034                 return NULL;
1035
1036         list_for_each_entry(hwid, &device->pnp.ids, list) {
1037                 /* First, check the ACPI/PNP IDs provided by the caller. */
1038                 for (id = ids; id->id[0]; id++)
1039                         if (!strcmp((char *) id->id, hwid->id))
1040                                 return id;
1041
1042                 /*
1043                  * Next, check ACPI_DT_NAMESPACE_HID and try to match the
1044                  * "compatible" property if found.
1045                  *
1046                  * The id returned by the below is not valid, but the only
1047                  * caller passing non-NULL of_ids here is only interested in
1048                  * whether or not the return value is NULL.
1049                  */
1050                 if (!strcmp(ACPI_DT_NAMESPACE_HID, hwid->id)
1051                     && acpi_of_match_device(device, of_ids))
1052                         return id;
1053         }
1054         return NULL;
1055 }
1056
1057 /**
1058  * acpi_match_device - Match a struct device against a given list of ACPI IDs
1059  * @ids: Array of struct acpi_device_id object to match against.
1060  * @dev: The device structure to match.
1061  *
1062  * Check if @dev has a valid ACPI handle and if there is a struct acpi_device
1063  * object for that handle and use that object to match against a given list of
1064  * device IDs.
1065  *
1066  * Return a pointer to the first matching ID on success or %NULL on failure.
1067  */
1068 const struct acpi_device_id *acpi_match_device(const struct acpi_device_id *ids,
1069                                                const struct device *dev)
1070 {
1071         return __acpi_match_device(acpi_companion_match(dev), ids, NULL);
1072 }
1073 EXPORT_SYMBOL_GPL(acpi_match_device);
1074
1075 int acpi_match_device_ids(struct acpi_device *device,
1076                           const struct acpi_device_id *ids)
1077 {
1078         return __acpi_match_device(device, ids, NULL) ? 0 : -ENOENT;
1079 }
1080 EXPORT_SYMBOL(acpi_match_device_ids);
1081
1082 bool acpi_driver_match_device(struct device *dev,
1083                               const struct device_driver *drv)
1084 {
1085         if (!drv->acpi_match_table)
1086                 return acpi_of_match_device(ACPI_COMPANION(dev),
1087                                             drv->of_match_table);
1088
1089         return !!__acpi_match_device(acpi_companion_match(dev),
1090                                      drv->acpi_match_table, drv->of_match_table);
1091 }
1092 EXPORT_SYMBOL_GPL(acpi_driver_match_device);
1093
1094 static void acpi_free_power_resources_lists(struct acpi_device *device)
1095 {
1096         int i;
1097
1098         if (device->wakeup.flags.valid)
1099                 acpi_power_resources_list_free(&device->wakeup.resources);
1100
1101         if (!device->power.flags.power_resources)
1102                 return;
1103
1104         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
1105                 struct acpi_device_power_state *ps = &device->power.states[i];
1106                 acpi_power_resources_list_free(&ps->resources);
1107         }
1108 }
1109
1110 static void acpi_device_release(struct device *dev)
1111 {
1112         struct acpi_device *acpi_dev = to_acpi_device(dev);
1113
1114         acpi_free_properties(acpi_dev);
1115         acpi_free_pnp_ids(&acpi_dev->pnp);
1116         acpi_free_power_resources_lists(acpi_dev);
1117         kfree(acpi_dev);
1118 }
1119
1120 static int acpi_bus_match(struct device *dev, struct device_driver *drv)
1121 {
1122         struct acpi_device *acpi_dev = to_acpi_device(dev);
1123         struct acpi_driver *acpi_drv = to_acpi_driver(drv);
1124
1125         return acpi_dev->flags.match_driver
1126                 && !acpi_match_device_ids(acpi_dev, acpi_drv->ids);
1127 }
1128
1129 static int acpi_device_uevent(struct device *dev, struct kobj_uevent_env *env)
1130 {
1131         return __acpi_device_uevent_modalias(to_acpi_device(dev), env);
1132 }
1133
1134 static void acpi_device_notify(acpi_handle handle, u32 event, void *data)
1135 {
1136         struct acpi_device *device = data;
1137
1138         device->driver->ops.notify(device, event);
1139 }
1140
1141 static void acpi_device_notify_fixed(void *data)
1142 {
1143         struct acpi_device *device = data;
1144
1145         /* Fixed hardware devices have no handles */
1146         acpi_device_notify(NULL, ACPI_FIXED_HARDWARE_EVENT, device);
1147 }
1148
1149 static u32 acpi_device_fixed_event(void *data)
1150 {
1151         acpi_os_execute(OSL_NOTIFY_HANDLER, acpi_device_notify_fixed, data);
1152         return ACPI_INTERRUPT_HANDLED;
1153 }
1154
1155 static int acpi_device_install_notify_handler(struct acpi_device *device)
1156 {
1157         acpi_status status;
1158
1159         if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
1160                 status =
1161                     acpi_install_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
1162                                                      acpi_device_fixed_event,
1163                                                      device);
1164         else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
1165                 status =
1166                     acpi_install_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
1167                                                      acpi_device_fixed_event,
1168                                                      device);
1169         else
1170                 status = acpi_install_notify_handler(device->handle,
1171                                                      ACPI_DEVICE_NOTIFY,
1172                                                      acpi_device_notify,
1173                                                      device);
1174
1175         if (ACPI_FAILURE(status))
1176                 return -EINVAL;
1177         return 0;
1178 }
1179
1180 static void acpi_device_remove_notify_handler(struct acpi_device *device)
1181 {
1182         if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
1183                 acpi_remove_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
1184                                                 acpi_device_fixed_event);
1185         else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
1186                 acpi_remove_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
1187                                                 acpi_device_fixed_event);
1188         else
1189                 acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
1190                                            acpi_device_notify);
1191 }
1192
1193 static int acpi_device_probe(struct device *dev)
1194 {
1195         struct acpi_device *acpi_dev = to_acpi_device(dev);
1196         struct acpi_driver *acpi_drv = to_acpi_driver(dev->driver);
1197         int ret;
1198
1199         if (acpi_dev->handler && !acpi_is_pnp_device(acpi_dev))
1200                 return -EINVAL;
1201
1202         if (!acpi_drv->ops.add)
1203                 return -ENOSYS;
1204
1205         ret = acpi_drv->ops.add(acpi_dev);
1206         if (ret)
1207                 return ret;
1208
1209         acpi_dev->driver = acpi_drv;
1210         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1211                           "Driver [%s] successfully bound to device [%s]\n",
1212                           acpi_drv->name, acpi_dev->pnp.bus_id));
1213
1214         if (acpi_drv->ops.notify) {
1215                 ret = acpi_device_install_notify_handler(acpi_dev);
1216                 if (ret) {
1217                         if (acpi_drv->ops.remove)
1218                                 acpi_drv->ops.remove(acpi_dev);
1219
1220                         acpi_dev->driver = NULL;
1221                         acpi_dev->driver_data = NULL;
1222                         return ret;
1223                 }
1224         }
1225
1226         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found driver [%s] for device [%s]\n",
1227                           acpi_drv->name, acpi_dev->pnp.bus_id));
1228         get_device(dev);
1229         return 0;
1230 }
1231
1232 static int acpi_device_remove(struct device * dev)
1233 {
1234         struct acpi_device *acpi_dev = to_acpi_device(dev);
1235         struct acpi_driver *acpi_drv = acpi_dev->driver;
1236
1237         if (acpi_drv) {
1238                 if (acpi_drv->ops.notify)
1239                         acpi_device_remove_notify_handler(acpi_dev);
1240                 if (acpi_drv->ops.remove)
1241                         acpi_drv->ops.remove(acpi_dev);
1242         }
1243         acpi_dev->driver = NULL;
1244         acpi_dev->driver_data = NULL;
1245
1246         put_device(dev);
1247         return 0;
1248 }
1249
1250 struct bus_type acpi_bus_type = {
1251         .name           = "acpi",
1252         .match          = acpi_bus_match,
1253         .probe          = acpi_device_probe,
1254         .remove         = acpi_device_remove,
1255         .uevent         = acpi_device_uevent,
1256 };
1257
1258 static void acpi_device_del(struct acpi_device *device)
1259 {
1260         mutex_lock(&acpi_device_lock);
1261         if (device->parent)
1262                 list_del(&device->node);
1263
1264         list_del(&device->wakeup_list);
1265         mutex_unlock(&acpi_device_lock);
1266
1267         acpi_power_add_remove_device(device, false);
1268         acpi_device_remove_files(device);
1269         if (device->remove)
1270                 device->remove(device);
1271
1272         device_del(&device->dev);
1273 }
1274
1275 static LIST_HEAD(acpi_device_del_list);
1276 static DEFINE_MUTEX(acpi_device_del_lock);
1277
1278 static void acpi_device_del_work_fn(struct work_struct *work_not_used)
1279 {
1280         for (;;) {
1281                 struct acpi_device *adev;
1282
1283                 mutex_lock(&acpi_device_del_lock);
1284
1285                 if (list_empty(&acpi_device_del_list)) {
1286                         mutex_unlock(&acpi_device_del_lock);
1287                         break;
1288                 }
1289                 adev = list_first_entry(&acpi_device_del_list,
1290                                         struct acpi_device, del_list);
1291                 list_del(&adev->del_list);
1292
1293                 mutex_unlock(&acpi_device_del_lock);
1294
1295                 acpi_device_del(adev);
1296                 /*
1297                  * Drop references to all power resources that might have been
1298                  * used by the device.
1299                  */
1300                 acpi_power_transition(adev, ACPI_STATE_D3_COLD);
1301                 put_device(&adev->dev);
1302         }
1303 }
1304
1305 /**
1306  * acpi_scan_drop_device - Drop an ACPI device object.
1307  * @handle: Handle of an ACPI namespace node, not used.
1308  * @context: Address of the ACPI device object to drop.
1309  *
1310  * This is invoked by acpi_ns_delete_node() during the removal of the ACPI
1311  * namespace node the device object pointed to by @context is attached to.
1312  *
1313  * The unregistration is carried out asynchronously to avoid running
1314  * acpi_device_del() under the ACPICA's namespace mutex and the list is used to
1315  * ensure the correct ordering (the device objects must be unregistered in the
1316  * same order in which the corresponding namespace nodes are deleted).
1317  */
1318 static void acpi_scan_drop_device(acpi_handle handle, void *context)
1319 {
1320         static DECLARE_WORK(work, acpi_device_del_work_fn);
1321         struct acpi_device *adev = context;
1322
1323         mutex_lock(&acpi_device_del_lock);
1324
1325         /*
1326          * Use the ACPI hotplug workqueue which is ordered, so this work item
1327          * won't run after any hotplug work items submitted subsequently.  That
1328          * prevents attempts to register device objects identical to those being
1329          * deleted from happening concurrently (such attempts result from
1330          * hotplug events handled via the ACPI hotplug workqueue).  It also will
1331          * run after all of the work items submitted previosuly, which helps
1332          * those work items to ensure that they are not accessing stale device
1333          * objects.
1334          */
1335         if (list_empty(&acpi_device_del_list))
1336                 acpi_queue_hotplug_work(&work);
1337
1338         list_add_tail(&adev->del_list, &acpi_device_del_list);
1339         /* Make acpi_ns_validate_handle() return NULL for this handle. */
1340         adev->handle = INVALID_ACPI_HANDLE;
1341
1342         mutex_unlock(&acpi_device_del_lock);
1343 }
1344
1345 static int acpi_get_device_data(acpi_handle handle, struct acpi_device **device,
1346                                 void (*callback)(void *))
1347 {
1348         acpi_status status;
1349
1350         if (!device)
1351                 return -EINVAL;
1352
1353         status = acpi_get_data_full(handle, acpi_scan_drop_device,
1354                                     (void **)device, callback);
1355         if (ACPI_FAILURE(status) || !*device) {
1356                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No context for object [%p]\n",
1357                                   handle));
1358                 return -ENODEV;
1359         }
1360         return 0;
1361 }
1362
1363 int acpi_bus_get_device(acpi_handle handle, struct acpi_device **device)
1364 {
1365         return acpi_get_device_data(handle, device, NULL);
1366 }
1367 EXPORT_SYMBOL(acpi_bus_get_device);
1368
1369 static void get_acpi_device(void *dev)
1370 {
1371         if (dev)
1372                 get_device(&((struct acpi_device *)dev)->dev);
1373 }
1374
1375 struct acpi_device *acpi_bus_get_acpi_device(acpi_handle handle)
1376 {
1377         struct acpi_device *adev = NULL;
1378
1379         acpi_get_device_data(handle, &adev, get_acpi_device);
1380         return adev;
1381 }
1382
1383 void acpi_bus_put_acpi_device(struct acpi_device *adev)
1384 {
1385         put_device(&adev->dev);
1386 }
1387
1388 int acpi_device_add(struct acpi_device *device,
1389                     void (*release)(struct device *))
1390 {
1391         int result;
1392         struct acpi_device_bus_id *acpi_device_bus_id, *new_bus_id;
1393         int found = 0;
1394
1395         if (device->handle) {
1396                 acpi_status status;
1397
1398                 status = acpi_attach_data(device->handle, acpi_scan_drop_device,
1399                                           device);
1400                 if (ACPI_FAILURE(status)) {
1401                         acpi_handle_err(device->handle,
1402                                         "Unable to attach device data\n");
1403                         return -ENODEV;
1404                 }
1405         }
1406
1407         /*
1408          * Linkage
1409          * -------
1410          * Link this device to its parent and siblings.
1411          */
1412         INIT_LIST_HEAD(&device->children);
1413         INIT_LIST_HEAD(&device->node);
1414         INIT_LIST_HEAD(&device->wakeup_list);
1415         INIT_LIST_HEAD(&device->physical_node_list);
1416         INIT_LIST_HEAD(&device->del_list);
1417         mutex_init(&device->physical_node_lock);
1418
1419         new_bus_id = kzalloc(sizeof(struct acpi_device_bus_id), GFP_KERNEL);
1420         if (!new_bus_id) {
1421                 pr_err(PREFIX "Memory allocation error\n");
1422                 result = -ENOMEM;
1423                 goto err_detach;
1424         }
1425
1426         mutex_lock(&acpi_device_lock);
1427         /*
1428          * Find suitable bus_id and instance number in acpi_bus_id_list
1429          * If failed, create one and link it into acpi_bus_id_list
1430          */
1431         list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
1432                 if (!strcmp(acpi_device_bus_id->bus_id,
1433                             acpi_device_hid(device))) {
1434                         acpi_device_bus_id->instance_no++;
1435                         found = 1;
1436                         kfree(new_bus_id);
1437                         break;
1438                 }
1439         }
1440         if (!found) {
1441                 acpi_device_bus_id = new_bus_id;
1442                 strcpy(acpi_device_bus_id->bus_id, acpi_device_hid(device));
1443                 acpi_device_bus_id->instance_no = 0;
1444                 list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
1445         }
1446         dev_set_name(&device->dev, "%s:%02x", acpi_device_bus_id->bus_id, acpi_device_bus_id->instance_no);
1447
1448         if (device->parent)
1449                 list_add_tail(&device->node, &device->parent->children);
1450
1451         if (device->wakeup.flags.valid)
1452                 list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);
1453         mutex_unlock(&acpi_device_lock);
1454
1455         if (device->parent)
1456                 device->dev.parent = &device->parent->dev;
1457         device->dev.bus = &acpi_bus_type;
1458         device->dev.release = release;
1459         result = device_add(&device->dev);
1460         if (result) {
1461                 dev_err(&device->dev, "Error registering device\n");
1462                 goto err;
1463         }
1464
1465         result = acpi_device_setup_files(device);
1466         if (result)
1467                 printk(KERN_ERR PREFIX "Error creating sysfs interface for device %s\n",
1468                        dev_name(&device->dev));
1469
1470         return 0;
1471
1472  err:
1473         mutex_lock(&acpi_device_lock);
1474         if (device->parent)
1475                 list_del(&device->node);
1476         list_del(&device->wakeup_list);
1477         mutex_unlock(&acpi_device_lock);
1478
1479  err_detach:
1480         acpi_detach_data(device->handle, acpi_scan_drop_device);
1481         return result;
1482 }
1483
1484 struct acpi_device *acpi_get_next_child(struct device *dev,
1485                                         struct acpi_device *child)
1486 {
1487         struct acpi_device *adev = ACPI_COMPANION(dev);
1488         struct list_head *head, *next;
1489
1490         if (!adev)
1491                 return NULL;
1492
1493         head = &adev->children;
1494         if (list_empty(head))
1495                 return NULL;
1496
1497         if (!child)
1498                 return list_first_entry(head, struct acpi_device, node);
1499
1500         next = child->node.next;
1501         return next == head ? NULL : list_entry(next, struct acpi_device, node);
1502 }
1503
1504 /* --------------------------------------------------------------------------
1505                                  Driver Management
1506    -------------------------------------------------------------------------- */
1507 /**
1508  * acpi_bus_register_driver - register a driver with the ACPI bus
1509  * @driver: driver being registered
1510  *
1511  * Registers a driver with the ACPI bus.  Searches the namespace for all
1512  * devices that match the driver's criteria and binds.  Returns zero for
1513  * success or a negative error status for failure.
1514  */
1515 int acpi_bus_register_driver(struct acpi_driver *driver)
1516 {
1517         int ret;
1518
1519         if (acpi_disabled)
1520                 return -ENODEV;
1521         driver->drv.name = driver->name;
1522         driver->drv.bus = &acpi_bus_type;
1523         driver->drv.owner = driver->owner;
1524
1525         ret = driver_register(&driver->drv);
1526         return ret;
1527 }
1528
1529 EXPORT_SYMBOL(acpi_bus_register_driver);
1530
1531 /**
1532  * acpi_bus_unregister_driver - unregisters a driver with the ACPI bus
1533  * @driver: driver to unregister
1534  *
1535  * Unregisters a driver with the ACPI bus.  Searches the namespace for all
1536  * devices that match the driver's criteria and unbinds.
1537  */
1538 void acpi_bus_unregister_driver(struct acpi_driver *driver)
1539 {
1540         driver_unregister(&driver->drv);
1541 }
1542
1543 EXPORT_SYMBOL(acpi_bus_unregister_driver);
1544
1545 /* --------------------------------------------------------------------------
1546                                  Device Enumeration
1547    -------------------------------------------------------------------------- */
1548 static struct acpi_device *acpi_bus_get_parent(acpi_handle handle)
1549 {
1550         struct acpi_device *device = NULL;
1551         acpi_status status;
1552
1553         /*
1554          * Fixed hardware devices do not appear in the namespace and do not
1555          * have handles, but we fabricate acpi_devices for them, so we have
1556          * to deal with them specially.
1557          */
1558         if (!handle)
1559                 return acpi_root;
1560
1561         do {
1562                 status = acpi_get_parent(handle, &handle);
1563                 if (ACPI_FAILURE(status))
1564                         return status == AE_NULL_ENTRY ? NULL : acpi_root;
1565         } while (acpi_bus_get_device(handle, &device));
1566         return device;
1567 }
1568
1569 acpi_status
1570 acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
1571 {
1572         acpi_status status;
1573         acpi_handle tmp;
1574         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
1575         union acpi_object *obj;
1576
1577         status = acpi_get_handle(handle, "_EJD", &tmp);
1578         if (ACPI_FAILURE(status))
1579                 return status;
1580
1581         status = acpi_evaluate_object(handle, "_EJD", NULL, &buffer);
1582         if (ACPI_SUCCESS(status)) {
1583                 obj = buffer.pointer;
1584                 status = acpi_get_handle(ACPI_ROOT_OBJECT, obj->string.pointer,
1585                                          ejd);
1586                 kfree(buffer.pointer);
1587         }
1588         return status;
1589 }
1590 EXPORT_SYMBOL_GPL(acpi_bus_get_ejd);
1591
1592 static int acpi_bus_extract_wakeup_device_power_package(acpi_handle handle,
1593                                         struct acpi_device_wakeup *wakeup)
1594 {
1595         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1596         union acpi_object *package = NULL;
1597         union acpi_object *element = NULL;
1598         acpi_status status;
1599         int err = -ENODATA;
1600
1601         if (!wakeup)
1602                 return -EINVAL;
1603
1604         INIT_LIST_HEAD(&wakeup->resources);
1605
1606         /* _PRW */
1607         status = acpi_evaluate_object(handle, "_PRW", NULL, &buffer);
1608         if (ACPI_FAILURE(status)) {
1609                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRW"));
1610                 return err;
1611         }
1612
1613         package = (union acpi_object *)buffer.pointer;
1614
1615         if (!package || package->package.count < 2)
1616                 goto out;
1617
1618         element = &(package->package.elements[0]);
1619         if (!element)
1620                 goto out;
1621
1622         if (element->type == ACPI_TYPE_PACKAGE) {
1623                 if ((element->package.count < 2) ||
1624                     (element->package.elements[0].type !=
1625                      ACPI_TYPE_LOCAL_REFERENCE)
1626                     || (element->package.elements[1].type != ACPI_TYPE_INTEGER))
1627                         goto out;
1628
1629                 wakeup->gpe_device =
1630                     element->package.elements[0].reference.handle;
1631                 wakeup->gpe_number =
1632                     (u32) element->package.elements[1].integer.value;
1633         } else if (element->type == ACPI_TYPE_INTEGER) {
1634                 wakeup->gpe_device = NULL;
1635                 wakeup->gpe_number = element->integer.value;
1636         } else {
1637                 goto out;
1638         }
1639
1640         element = &(package->package.elements[1]);
1641         if (element->type != ACPI_TYPE_INTEGER)
1642                 goto out;
1643
1644         wakeup->sleep_state = element->integer.value;
1645
1646         err = acpi_extract_power_resources(package, 2, &wakeup->resources);
1647         if (err)
1648                 goto out;
1649
1650         if (!list_empty(&wakeup->resources)) {
1651                 int sleep_state;
1652
1653                 err = acpi_power_wakeup_list_init(&wakeup->resources,
1654                                                   &sleep_state);
1655                 if (err) {
1656                         acpi_handle_warn(handle, "Retrieving current states "
1657                                          "of wakeup power resources failed\n");
1658                         acpi_power_resources_list_free(&wakeup->resources);
1659                         goto out;
1660                 }
1661                 if (sleep_state < wakeup->sleep_state) {
1662                         acpi_handle_warn(handle, "Overriding _PRW sleep state "
1663                                          "(S%d) by S%d from power resources\n",
1664                                          (int)wakeup->sleep_state, sleep_state);
1665                         wakeup->sleep_state = sleep_state;
1666                 }
1667         }
1668
1669  out:
1670         kfree(buffer.pointer);
1671         return err;
1672 }
1673
1674 static void acpi_wakeup_gpe_init(struct acpi_device *device)
1675 {
1676         static const struct acpi_device_id button_device_ids[] = {
1677                 {"PNP0C0C", 0},
1678                 {"PNP0C0D", 0},
1679                 {"PNP0C0E", 0},
1680                 {"", 0},
1681         };
1682         struct acpi_device_wakeup *wakeup = &device->wakeup;
1683         acpi_status status;
1684         acpi_event_status event_status;
1685
1686         wakeup->flags.notifier_present = 0;
1687
1688         /* Power button, Lid switch always enable wakeup */
1689         if (!acpi_match_device_ids(device, button_device_ids)) {
1690                 wakeup->flags.run_wake = 1;
1691                 if (!acpi_match_device_ids(device, &button_device_ids[1])) {
1692                         /* Do not use Lid/sleep button for S5 wakeup */
1693                         if (wakeup->sleep_state == ACPI_STATE_S5)
1694                                 wakeup->sleep_state = ACPI_STATE_S4;
1695                 }
1696                 acpi_mark_gpe_for_wake(wakeup->gpe_device, wakeup->gpe_number);
1697                 device_set_wakeup_capable(&device->dev, true);
1698                 return;
1699         }
1700
1701         acpi_setup_gpe_for_wake(device->handle, wakeup->gpe_device,
1702                                 wakeup->gpe_number);
1703         status = acpi_get_gpe_status(wakeup->gpe_device, wakeup->gpe_number,
1704                                      &event_status);
1705         if (ACPI_FAILURE(status))
1706                 return;
1707
1708         wakeup->flags.run_wake = !!(event_status & ACPI_EVENT_FLAG_HAS_HANDLER);
1709 }
1710
1711 static void acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
1712 {
1713         int err;
1714
1715         /* Presence of _PRW indicates wake capable */
1716         if (!acpi_has_method(device->handle, "_PRW"))
1717                 return;
1718
1719         err = acpi_bus_extract_wakeup_device_power_package(device->handle,
1720                                                            &device->wakeup);
1721         if (err) {
1722                 dev_err(&device->dev, "_PRW evaluation error: %d\n", err);
1723                 return;
1724         }
1725
1726         device->wakeup.flags.valid = 1;
1727         device->wakeup.prepare_count = 0;
1728         acpi_wakeup_gpe_init(device);
1729         /* Call _PSW/_DSW object to disable its ability to wake the sleeping
1730          * system for the ACPI device with the _PRW object.
1731          * The _PSW object is depreciated in ACPI 3.0 and is replaced by _DSW.
1732          * So it is necessary to call _DSW object first. Only when it is not
1733          * present will the _PSW object used.
1734          */
1735         err = acpi_device_sleep_wake(device, 0, 0, 0);
1736         if (err)
1737                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1738                                 "error in _DSW or _PSW evaluation\n"));
1739 }
1740
1741 static void acpi_bus_init_power_state(struct acpi_device *device, int state)
1742 {
1743         struct acpi_device_power_state *ps = &device->power.states[state];
1744         char pathname[5] = { '_', 'P', 'R', '0' + state, '\0' };
1745         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1746         acpi_status status;
1747
1748         INIT_LIST_HEAD(&ps->resources);
1749
1750         /* Evaluate "_PRx" to get referenced power resources */
1751         status = acpi_evaluate_object(device->handle, pathname, NULL, &buffer);
1752         if (ACPI_SUCCESS(status)) {
1753                 union acpi_object *package = buffer.pointer;
1754
1755                 if (buffer.length && package
1756                     && package->type == ACPI_TYPE_PACKAGE
1757                     && package->package.count) {
1758                         int err = acpi_extract_power_resources(package, 0,
1759                                                                &ps->resources);
1760                         if (!err)
1761                                 device->power.flags.power_resources = 1;
1762                 }
1763                 ACPI_FREE(buffer.pointer);
1764         }
1765
1766         /* Evaluate "_PSx" to see if we can do explicit sets */
1767         pathname[2] = 'S';
1768         if (acpi_has_method(device->handle, pathname))
1769                 ps->flags.explicit_set = 1;
1770
1771         /*
1772          * State is valid if there are means to put the device into it.
1773          * D3hot is only valid if _PR3 present.
1774          */
1775         if (!list_empty(&ps->resources)
1776             || (ps->flags.explicit_set && state < ACPI_STATE_D3_HOT)) {
1777                 ps->flags.valid = 1;
1778                 ps->flags.os_accessible = 1;
1779         }
1780
1781         ps->power = -1;         /* Unknown - driver assigned */
1782         ps->latency = -1;       /* Unknown - driver assigned */
1783 }
1784
1785 static void acpi_bus_get_power_flags(struct acpi_device *device)
1786 {
1787         u32 i;
1788
1789         /* Presence of _PS0|_PR0 indicates 'power manageable' */
1790         if (!acpi_has_method(device->handle, "_PS0") &&
1791             !acpi_has_method(device->handle, "_PR0"))
1792                 return;
1793
1794         device->flags.power_manageable = 1;
1795
1796         /*
1797          * Power Management Flags
1798          */
1799         if (acpi_has_method(device->handle, "_PSC"))
1800                 device->power.flags.explicit_get = 1;
1801
1802         if (acpi_has_method(device->handle, "_IRC"))
1803                 device->power.flags.inrush_current = 1;
1804
1805         if (acpi_has_method(device->handle, "_DSW"))
1806                 device->power.flags.dsw_present = 1;
1807
1808         /*
1809          * Enumerate supported power management states
1810          */
1811         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++)
1812                 acpi_bus_init_power_state(device, i);
1813
1814         INIT_LIST_HEAD(&device->power.states[ACPI_STATE_D3_COLD].resources);
1815
1816         /* Set defaults for D0 and D3 states (always valid) */
1817         device->power.states[ACPI_STATE_D0].flags.valid = 1;
1818         device->power.states[ACPI_STATE_D0].power = 100;
1819         device->power.states[ACPI_STATE_D3_COLD].flags.valid = 1;
1820         device->power.states[ACPI_STATE_D3_COLD].power = 0;
1821
1822         /* Set D3cold's explicit_set flag if _PS3 exists. */
1823         if (device->power.states[ACPI_STATE_D3_HOT].flags.explicit_set)
1824                 device->power.states[ACPI_STATE_D3_COLD].flags.explicit_set = 1;
1825
1826         /* Presence of _PS3 or _PRx means we can put the device into D3 cold */
1827         if (device->power.states[ACPI_STATE_D3_HOT].flags.explicit_set ||
1828                         device->power.flags.power_resources)
1829                 device->power.states[ACPI_STATE_D3_COLD].flags.os_accessible = 1;
1830
1831         if (acpi_bus_init_power(device))
1832                 device->flags.power_manageable = 0;
1833 }
1834
1835 static void acpi_bus_get_flags(struct acpi_device *device)
1836 {
1837         /* Presence of _STA indicates 'dynamic_status' */
1838         if (acpi_has_method(device->handle, "_STA"))
1839                 device->flags.dynamic_status = 1;
1840
1841         /* Presence of _RMV indicates 'removable' */
1842         if (acpi_has_method(device->handle, "_RMV"))
1843                 device->flags.removable = 1;
1844
1845         /* Presence of _EJD|_EJ0 indicates 'ejectable' */
1846         if (acpi_has_method(device->handle, "_EJD") ||
1847             acpi_has_method(device->handle, "_EJ0"))
1848                 device->flags.ejectable = 1;
1849 }
1850
1851 static void acpi_device_get_busid(struct acpi_device *device)
1852 {
1853         char bus_id[5] = { '?', 0 };
1854         struct acpi_buffer buffer = { sizeof(bus_id), bus_id };
1855         int i = 0;
1856
1857         /*
1858          * Bus ID
1859          * ------
1860          * The device's Bus ID is simply the object name.
1861          * TBD: Shouldn't this value be unique (within the ACPI namespace)?
1862          */
1863         if (ACPI_IS_ROOT_DEVICE(device)) {
1864                 strcpy(device->pnp.bus_id, "ACPI");
1865                 return;
1866         }
1867
1868         switch (device->device_type) {
1869         case ACPI_BUS_TYPE_POWER_BUTTON:
1870                 strcpy(device->pnp.bus_id, "PWRF");
1871                 break;
1872         case ACPI_BUS_TYPE_SLEEP_BUTTON:
1873                 strcpy(device->pnp.bus_id, "SLPF");
1874                 break;
1875         default:
1876                 acpi_get_name(device->handle, ACPI_SINGLE_NAME, &buffer);
1877                 /* Clean up trailing underscores (if any) */
1878                 for (i = 3; i > 1; i--) {
1879                         if (bus_id[i] == '_')
1880                                 bus_id[i] = '\0';
1881                         else
1882                                 break;
1883                 }
1884                 strcpy(device->pnp.bus_id, bus_id);
1885                 break;
1886         }
1887 }
1888
1889 /*
1890  * acpi_ata_match - see if an acpi object is an ATA device
1891  *
1892  * If an acpi object has one of the ACPI ATA methods defined,
1893  * then we can safely call it an ATA device.
1894  */
1895 bool acpi_ata_match(acpi_handle handle)
1896 {
1897         return acpi_has_method(handle, "_GTF") ||
1898                acpi_has_method(handle, "_GTM") ||
1899                acpi_has_method(handle, "_STM") ||
1900                acpi_has_method(handle, "_SDD");
1901 }
1902
1903 /*
1904  * acpi_bay_match - see if an acpi object is an ejectable driver bay
1905  *
1906  * If an acpi object is ejectable and has one of the ACPI ATA methods defined,
1907  * then we can safely call it an ejectable drive bay
1908  */
1909 bool acpi_bay_match(acpi_handle handle)
1910 {
1911         acpi_handle phandle;
1912
1913         if (!acpi_has_method(handle, "_EJ0"))
1914                 return false;
1915         if (acpi_ata_match(handle))
1916                 return true;
1917         if (ACPI_FAILURE(acpi_get_parent(handle, &phandle)))
1918                 return false;
1919
1920         return acpi_ata_match(phandle);
1921 }
1922
1923 bool acpi_device_is_battery(struct acpi_device *adev)
1924 {
1925         struct acpi_hardware_id *hwid;
1926
1927         list_for_each_entry(hwid, &adev->pnp.ids, list)
1928                 if (!strcmp("PNP0C0A", hwid->id))
1929                         return true;
1930
1931         return false;
1932 }
1933
1934 static bool is_ejectable_bay(struct acpi_device *adev)
1935 {
1936         acpi_handle handle = adev->handle;
1937
1938         if (acpi_has_method(handle, "_EJ0") && acpi_device_is_battery(adev))
1939                 return true;
1940
1941         return acpi_bay_match(handle);
1942 }
1943
1944 /*
1945  * acpi_dock_match - see if an acpi object has a _DCK method
1946  */
1947 bool acpi_dock_match(acpi_handle handle)
1948 {
1949         return acpi_has_method(handle, "_DCK");
1950 }
1951
1952 const char *acpi_device_hid(struct acpi_device *device)
1953 {
1954         struct acpi_hardware_id *hid;
1955
1956         if (list_empty(&device->pnp.ids))
1957                 return dummy_hid;
1958
1959         hid = list_first_entry(&device->pnp.ids, struct acpi_hardware_id, list);
1960         return hid->id;
1961 }
1962 EXPORT_SYMBOL(acpi_device_hid);
1963
1964 static void acpi_add_id(struct acpi_device_pnp *pnp, const char *dev_id)
1965 {
1966         struct acpi_hardware_id *id;
1967
1968         id = kmalloc(sizeof(*id), GFP_KERNEL);
1969         if (!id)
1970                 return;
1971
1972         id->id = kstrdup(dev_id, GFP_KERNEL);
1973         if (!id->id) {
1974                 kfree(id);
1975                 return;
1976         }
1977
1978         list_add_tail(&id->list, &pnp->ids);
1979         pnp->type.hardware_id = 1;
1980 }
1981
1982 /*
1983  * Old IBM workstations have a DSDT bug wherein the SMBus object
1984  * lacks the SMBUS01 HID and the methods do not have the necessary "_"
1985  * prefix.  Work around this.
1986  */
1987 static bool acpi_ibm_smbus_match(acpi_handle handle)
1988 {
1989         char node_name[ACPI_PATH_SEGMENT_LENGTH];
1990         struct acpi_buffer path = { sizeof(node_name), node_name };
1991
1992         if (!dmi_name_in_vendors("IBM"))
1993                 return false;
1994
1995         /* Look for SMBS object */
1996         if (ACPI_FAILURE(acpi_get_name(handle, ACPI_SINGLE_NAME, &path)) ||
1997             strcmp("SMBS", path.pointer))
1998                 return false;
1999
2000         /* Does it have the necessary (but misnamed) methods? */
2001         if (acpi_has_method(handle, "SBI") &&
2002             acpi_has_method(handle, "SBR") &&
2003             acpi_has_method(handle, "SBW"))
2004                 return true;
2005
2006         return false;
2007 }
2008
2009 static bool acpi_object_is_system_bus(acpi_handle handle)
2010 {
2011         acpi_handle tmp;
2012
2013         if (ACPI_SUCCESS(acpi_get_handle(NULL, "\\_SB", &tmp)) &&
2014             tmp == handle)
2015                 return true;
2016         if (ACPI_SUCCESS(acpi_get_handle(NULL, "\\_TZ", &tmp)) &&
2017             tmp == handle)
2018                 return true;
2019
2020         return false;
2021 }
2022
2023 static void acpi_set_pnp_ids(acpi_handle handle, struct acpi_device_pnp *pnp,
2024                                 int device_type)
2025 {
2026         acpi_status status;
2027         struct acpi_device_info *info;
2028         struct acpi_pnp_device_id_list *cid_list;
2029         int i;
2030
2031         switch (device_type) {
2032         case ACPI_BUS_TYPE_DEVICE:
2033                 if (handle == ACPI_ROOT_OBJECT) {
2034                         acpi_add_id(pnp, ACPI_SYSTEM_HID);
2035                         break;
2036                 }
2037
2038                 status = acpi_get_object_info(handle, &info);
2039                 if (ACPI_FAILURE(status)) {
2040                         pr_err(PREFIX "%s: Error reading device info\n",
2041                                         __func__);
2042                         return;
2043                 }
2044
2045                 if (info->valid & ACPI_VALID_HID) {
2046                         acpi_add_id(pnp, info->hardware_id.string);
2047                         pnp->type.platform_id = 1;
2048                 }
2049                 if (info->valid & ACPI_VALID_CID) {
2050                         cid_list = &info->compatible_id_list;
2051                         for (i = 0; i < cid_list->count; i++)
2052                                 acpi_add_id(pnp, cid_list->ids[i].string);
2053                 }
2054                 if (info->valid & ACPI_VALID_ADR) {
2055                         pnp->bus_address = info->address;
2056                         pnp->type.bus_address = 1;
2057                 }
2058                 if (info->valid & ACPI_VALID_UID)
2059                         pnp->unique_id = kstrdup(info->unique_id.string,
2060                                                         GFP_KERNEL);
2061
2062                 kfree(info);
2063
2064                 /*
2065                  * Some devices don't reliably have _HIDs & _CIDs, so add
2066                  * synthetic HIDs to make sure drivers can find them.
2067                  */
2068                 if (acpi_is_video_device(handle))
2069                         acpi_add_id(pnp, ACPI_VIDEO_HID);
2070                 else if (acpi_bay_match(handle))
2071                         acpi_add_id(pnp, ACPI_BAY_HID);
2072                 else if (acpi_dock_match(handle))
2073                         acpi_add_id(pnp, ACPI_DOCK_HID);
2074                 else if (acpi_ibm_smbus_match(handle))
2075                         acpi_add_id(pnp, ACPI_SMBUS_IBM_HID);
2076                 else if (list_empty(&pnp->ids) &&
2077                          acpi_object_is_system_bus(handle)) {
2078                         /* \_SB, \_TZ, LNXSYBUS */
2079                         acpi_add_id(pnp, ACPI_BUS_HID);
2080                         strcpy(pnp->device_name, ACPI_BUS_DEVICE_NAME);
2081                         strcpy(pnp->device_class, ACPI_BUS_CLASS);
2082                 }
2083
2084                 break;
2085         case ACPI_BUS_TYPE_POWER:
2086                 acpi_add_id(pnp, ACPI_POWER_HID);
2087                 break;
2088         case ACPI_BUS_TYPE_PROCESSOR:
2089                 acpi_add_id(pnp, ACPI_PROCESSOR_OBJECT_HID);
2090                 break;
2091         case ACPI_BUS_TYPE_THERMAL:
2092                 acpi_add_id(pnp, ACPI_THERMAL_HID);
2093                 break;
2094         case ACPI_BUS_TYPE_POWER_BUTTON:
2095                 acpi_add_id(pnp, ACPI_BUTTON_HID_POWERF);
2096                 break;
2097         case ACPI_BUS_TYPE_SLEEP_BUTTON:
2098                 acpi_add_id(pnp, ACPI_BUTTON_HID_SLEEPF);
2099                 break;
2100         }
2101 }
2102
2103 void acpi_free_pnp_ids(struct acpi_device_pnp *pnp)
2104 {
2105         struct acpi_hardware_id *id, *tmp;
2106
2107         list_for_each_entry_safe(id, tmp, &pnp->ids, list) {
2108                 kfree(id->id);
2109                 kfree(id);
2110         }
2111         kfree(pnp->unique_id);
2112 }
2113
2114 void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,
2115                              int type, unsigned long long sta)
2116 {
2117         INIT_LIST_HEAD(&device->pnp.ids);
2118         device->device_type = type;
2119         device->handle = handle;
2120         device->parent = acpi_bus_get_parent(handle);
2121         device->fwnode.type = FWNODE_ACPI;
2122         acpi_set_device_status(device, sta);
2123         acpi_device_get_busid(device);
2124         acpi_set_pnp_ids(handle, &device->pnp, type);
2125         acpi_init_properties(device);
2126         acpi_bus_get_flags(device);
2127         device->flags.match_driver = false;
2128         device->flags.initialized = true;
2129         device->flags.visited = false;
2130         device_initialize(&device->dev);
2131         dev_set_uevent_suppress(&device->dev, true);
2132 }
2133
2134 void acpi_device_add_finalize(struct acpi_device *device)
2135 {
2136         dev_set_uevent_suppress(&device->dev, false);
2137         kobject_uevent(&device->dev.kobj, KOBJ_ADD);
2138 }
2139
2140 static int acpi_add_single_object(struct acpi_device **child,
2141                                   acpi_handle handle, int type,
2142                                   unsigned long long sta)
2143 {
2144         int result;
2145         struct acpi_device *device;
2146         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
2147
2148         device = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
2149         if (!device) {
2150                 printk(KERN_ERR PREFIX "Memory allocation error\n");
2151                 return -ENOMEM;
2152         }
2153
2154         acpi_init_device_object(device, handle, type, sta);
2155         acpi_bus_get_power_flags(device);
2156         acpi_bus_get_wakeup_device_flags(device);
2157
2158         result = acpi_device_add(device, acpi_device_release);
2159         if (result) {
2160                 acpi_device_release(&device->dev);
2161                 return result;
2162         }
2163
2164         acpi_power_add_remove_device(device, true);
2165         acpi_device_add_finalize(device);
2166         acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
2167         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Added %s [%s] parent %s\n",
2168                 dev_name(&device->dev), (char *) buffer.pointer,
2169                 device->parent ? dev_name(&device->parent->dev) : "(null)"));
2170         kfree(buffer.pointer);
2171         *child = device;
2172         return 0;
2173 }
2174
2175 static int acpi_bus_type_and_status(acpi_handle handle, int *type,
2176                                     unsigned long long *sta)
2177 {
2178         acpi_status status;
2179         acpi_object_type acpi_type;
2180
2181         status = acpi_get_type(handle, &acpi_type);
2182         if (ACPI_FAILURE(status))
2183                 return -ENODEV;
2184
2185         switch (acpi_type) {
2186         case ACPI_TYPE_ANY:             /* for ACPI_ROOT_OBJECT */
2187         case ACPI_TYPE_DEVICE:
2188                 *type = ACPI_BUS_TYPE_DEVICE;
2189                 status = acpi_bus_get_status_handle(handle, sta);
2190                 if (ACPI_FAILURE(status))
2191                         return -ENODEV;
2192                 break;
2193         case ACPI_TYPE_PROCESSOR:
2194                 *type = ACPI_BUS_TYPE_PROCESSOR;
2195                 status = acpi_bus_get_status_handle(handle, sta);
2196                 if (ACPI_FAILURE(status))
2197                         return -ENODEV;
2198                 break;
2199         case ACPI_TYPE_THERMAL:
2200                 *type = ACPI_BUS_TYPE_THERMAL;
2201                 *sta = ACPI_STA_DEFAULT;
2202                 break;
2203         case ACPI_TYPE_POWER:
2204                 *type = ACPI_BUS_TYPE_POWER;
2205                 *sta = ACPI_STA_DEFAULT;
2206                 break;
2207         default:
2208                 return -ENODEV;
2209         }
2210
2211         return 0;
2212 }
2213
2214 bool acpi_device_is_present(struct acpi_device *adev)
2215 {
2216         if (adev->status.present || adev->status.functional)
2217                 return true;
2218
2219         adev->flags.initialized = false;
2220         return false;
2221 }
2222
2223 static bool acpi_scan_handler_matching(struct acpi_scan_handler *handler,
2224                                        char *idstr,
2225                                        const struct acpi_device_id **matchid)
2226 {
2227         const struct acpi_device_id *devid;
2228
2229         if (handler->match)
2230                 return handler->match(idstr, matchid);
2231
2232         for (devid = handler->ids; devid->id[0]; devid++)
2233                 if (!strcmp((char *)devid->id, idstr)) {
2234                         if (matchid)
2235                                 *matchid = devid;
2236
2237                         return true;
2238                 }
2239
2240         return false;
2241 }
2242
2243 static struct acpi_scan_handler *acpi_scan_match_handler(char *idstr,
2244                                         const struct acpi_device_id **matchid)
2245 {
2246         struct acpi_scan_handler *handler;
2247
2248         list_for_each_entry(handler, &acpi_scan_handlers_list, list_node)
2249                 if (acpi_scan_handler_matching(handler, idstr, matchid))
2250                         return handler;
2251
2252         return NULL;
2253 }
2254
2255 void acpi_scan_hotplug_enabled(struct acpi_hotplug_profile *hotplug, bool val)
2256 {
2257         if (!!hotplug->enabled == !!val)
2258                 return;
2259
2260         mutex_lock(&acpi_scan_lock);
2261
2262         hotplug->enabled = val;
2263
2264         mutex_unlock(&acpi_scan_lock);
2265 }
2266
2267 static void acpi_scan_init_hotplug(struct acpi_device *adev)
2268 {
2269         struct acpi_hardware_id *hwid;
2270
2271         if (acpi_dock_match(adev->handle) || is_ejectable_bay(adev)) {
2272                 acpi_dock_add(adev);
2273                 return;
2274         }
2275         list_for_each_entry(hwid, &adev->pnp.ids, list) {
2276                 struct acpi_scan_handler *handler;
2277
2278                 handler = acpi_scan_match_handler(hwid->id, NULL);
2279                 if (handler) {
2280                         adev->flags.hotplug_notify = true;
2281                         break;
2282                 }
2283         }
2284 }
2285
2286 static void acpi_device_dep_initialize(struct acpi_device *adev)
2287 {
2288         struct acpi_dep_data *dep;
2289         struct acpi_handle_list dep_devices;
2290         acpi_status status;
2291         int i;
2292
2293         if (!acpi_has_method(adev->handle, "_DEP"))
2294                 return;
2295
2296         status = acpi_evaluate_reference(adev->handle, "_DEP", NULL,
2297                                         &dep_devices);
2298         if (ACPI_FAILURE(status)) {
2299                 dev_dbg(&adev->dev, "Failed to evaluate _DEP.\n");
2300                 return;
2301         }
2302
2303         for (i = 0; i < dep_devices.count; i++) {
2304                 struct acpi_device_info *info;
2305                 int skip;
2306
2307                 status = acpi_get_object_info(dep_devices.handles[i], &info);
2308                 if (ACPI_FAILURE(status)) {
2309                         dev_dbg(&adev->dev, "Error reading _DEP device info\n");
2310                         continue;
2311                 }
2312
2313                 /*
2314                  * Skip the dependency of Windows System Power
2315                  * Management Controller
2316                  */
2317                 skip = info->valid & ACPI_VALID_HID &&
2318                         !strcmp(info->hardware_id.string, "INT3396");
2319
2320                 kfree(info);
2321
2322                 if (skip)
2323                         continue;
2324
2325                 dep = kzalloc(sizeof(struct acpi_dep_data), GFP_KERNEL);
2326                 if (!dep)
2327                         return;
2328
2329                 dep->master = dep_devices.handles[i];
2330                 dep->slave  = adev->handle;
2331                 adev->dep_unmet++;
2332
2333                 mutex_lock(&acpi_dep_list_lock);
2334                 list_add_tail(&dep->node , &acpi_dep_list);
2335                 mutex_unlock(&acpi_dep_list_lock);
2336         }
2337 }
2338
2339 static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl_not_used,
2340                                       void *not_used, void **return_value)
2341 {
2342         struct acpi_device *device = NULL;
2343         int type;
2344         unsigned long long sta;
2345         int result;
2346
2347         acpi_bus_get_device(handle, &device);
2348         if (device)
2349                 goto out;
2350
2351         result = acpi_bus_type_and_status(handle, &type, &sta);
2352         if (result)
2353                 return AE_OK;
2354
2355         if (type == ACPI_BUS_TYPE_POWER) {
2356                 acpi_add_power_resource(handle);
2357                 return AE_OK;
2358         }
2359
2360         acpi_add_single_object(&device, handle, type, sta);
2361         if (!device)
2362                 return AE_CTRL_DEPTH;
2363
2364         acpi_scan_init_hotplug(device);
2365         acpi_device_dep_initialize(device);
2366
2367  out:
2368         if (!*return_value)
2369                 *return_value = device;
2370
2371         return AE_OK;
2372 }
2373
2374 static int acpi_check_spi_i2c_slave(struct acpi_resource *ares, void *data)
2375 {
2376         bool *is_spi_i2c_slave_p = data;
2377
2378         if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
2379                 return 1;
2380
2381         /*
2382          * devices that are connected to UART still need to be enumerated to
2383          * platform bus
2384          */
2385         if (ares->data.common_serial_bus.type != ACPI_RESOURCE_SERIAL_TYPE_UART)
2386                 *is_spi_i2c_slave_p = true;
2387
2388          /* no need to do more checking */
2389         return -1;
2390 }
2391
2392 static void acpi_default_enumeration(struct acpi_device *device)
2393 {
2394         struct list_head resource_list;
2395         bool is_spi_i2c_slave = false;
2396
2397         /*
2398          * Do not enemerate SPI/I2C slaves as they will be enuerated by their
2399          * respective parents.
2400          */
2401         INIT_LIST_HEAD(&resource_list);
2402         acpi_dev_get_resources(device, &resource_list, acpi_check_spi_i2c_slave,
2403                                &is_spi_i2c_slave);
2404         acpi_dev_free_resource_list(&resource_list);
2405         if (!is_spi_i2c_slave)
2406                 acpi_create_platform_device(device);
2407 }
2408
2409 static const struct acpi_device_id generic_device_ids[] = {
2410         {ACPI_DT_NAMESPACE_HID, },
2411         {"", },
2412 };
2413
2414 static int acpi_generic_device_attach(struct acpi_device *adev,
2415                                       const struct acpi_device_id *not_used)
2416 {
2417         /*
2418          * Since ACPI_DT_NAMESPACE_HID is the only ID handled here, the test
2419          * below can be unconditional.
2420          */
2421         if (adev->data.of_compatible)
2422                 acpi_default_enumeration(adev);
2423
2424         return 1;
2425 }
2426
2427 static struct acpi_scan_handler generic_device_handler = {
2428         .ids = generic_device_ids,
2429         .attach = acpi_generic_device_attach,
2430 };
2431
2432 static int acpi_scan_attach_handler(struct acpi_device *device)
2433 {
2434         struct acpi_hardware_id *hwid;
2435         int ret = 0;
2436
2437         list_for_each_entry(hwid, &device->pnp.ids, list) {
2438                 const struct acpi_device_id *devid;
2439                 struct acpi_scan_handler *handler;
2440
2441                 handler = acpi_scan_match_handler(hwid->id, &devid);
2442                 if (handler) {
2443                         if (!handler->attach) {
2444                                 device->pnp.type.platform_id = 0;
2445                                 continue;
2446                         }
2447                         device->handler = handler;
2448                         ret = handler->attach(device, devid);
2449                         if (ret > 0)
2450                                 break;
2451
2452                         device->handler = NULL;
2453                         if (ret < 0)
2454                                 break;
2455                 }
2456         }
2457
2458         return ret;
2459 }
2460
2461 static void acpi_bus_attach(struct acpi_device *device)
2462 {
2463         struct acpi_device *child;
2464         acpi_handle ejd;
2465         int ret;
2466
2467         if (ACPI_SUCCESS(acpi_bus_get_ejd(device->handle, &ejd)))
2468                 register_dock_dependent_device(device, ejd);
2469
2470         acpi_bus_get_status(device);
2471         /* Skip devices that are not present. */
2472         if (!acpi_device_is_present(device)) {
2473                 device->flags.visited = false;
2474                 device->flags.power_manageable = 0;
2475                 return;
2476         }
2477         if (device->handler)
2478                 goto ok;
2479
2480         if (!device->flags.initialized) {
2481                 device->flags.power_manageable =
2482                         device->power.states[ACPI_STATE_D0].flags.valid;
2483                 if (acpi_bus_init_power(device))
2484                         device->flags.power_manageable = 0;
2485
2486                 device->flags.initialized = true;
2487         }
2488         device->flags.visited = false;
2489         ret = acpi_scan_attach_handler(device);
2490         if (ret < 0)
2491                 return;
2492
2493         device->flags.match_driver = true;
2494         if (!ret) {
2495                 ret = device_attach(&device->dev);
2496                 if (ret < 0)
2497                         return;
2498
2499                 if (!ret && device->pnp.type.platform_id)
2500                         acpi_default_enumeration(device);
2501         }
2502         device->flags.visited = true;
2503
2504  ok:
2505         list_for_each_entry(child, &device->children, node)
2506                 acpi_bus_attach(child);
2507
2508         if (device->handler && device->handler->hotplug.notify_online)
2509                 device->handler->hotplug.notify_online(device);
2510 }
2511
2512 void acpi_walk_dep_device_list(acpi_handle handle)
2513 {
2514         struct acpi_dep_data *dep, *tmp;
2515         struct acpi_device *adev;
2516
2517         mutex_lock(&acpi_dep_list_lock);
2518         list_for_each_entry_safe(dep, tmp, &acpi_dep_list, node) {
2519                 if (dep->master == handle) {
2520                         acpi_bus_get_device(dep->slave, &adev);
2521                         if (!adev)
2522                                 continue;
2523
2524                         adev->dep_unmet--;
2525                         if (!adev->dep_unmet)
2526                                 acpi_bus_attach(adev);
2527                         list_del(&dep->node);
2528                         kfree(dep);
2529                 }
2530         }
2531         mutex_unlock(&acpi_dep_list_lock);
2532 }
2533 EXPORT_SYMBOL_GPL(acpi_walk_dep_device_list);
2534
2535 /**
2536  * acpi_bus_scan - Add ACPI device node objects in a given namespace scope.
2537  * @handle: Root of the namespace scope to scan.
2538  *
2539  * Scan a given ACPI tree (probably recently hot-plugged) and create and add
2540  * found devices.
2541  *
2542  * If no devices were found, -ENODEV is returned, but it does not mean that
2543  * there has been a real error.  There just have been no suitable ACPI objects
2544  * in the table trunk from which the kernel could create a device and add an
2545  * appropriate driver.
2546  *
2547  * Must be called under acpi_scan_lock.
2548  */
2549 int acpi_bus_scan(acpi_handle handle)
2550 {
2551         void *device = NULL;
2552
2553         if (ACPI_SUCCESS(acpi_bus_check_add(handle, 0, NULL, &device)))
2554                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
2555                                     acpi_bus_check_add, NULL, NULL, &device);
2556
2557         if (device) {
2558                 acpi_bus_attach(device);
2559                 return 0;
2560         }
2561         return -ENODEV;
2562 }
2563 EXPORT_SYMBOL(acpi_bus_scan);
2564
2565 /**
2566  * acpi_bus_trim - Detach scan handlers and drivers from ACPI device objects.
2567  * @adev: Root of the ACPI namespace scope to walk.
2568  *
2569  * Must be called under acpi_scan_lock.
2570  */
2571 void acpi_bus_trim(struct acpi_device *adev)
2572 {
2573         struct acpi_scan_handler *handler = adev->handler;
2574         struct acpi_device *child;
2575
2576         list_for_each_entry_reverse(child, &adev->children, node)
2577                 acpi_bus_trim(child);
2578
2579         adev->flags.match_driver = false;
2580         if (handler) {
2581                 if (handler->detach)
2582                         handler->detach(adev);
2583
2584                 adev->handler = NULL;
2585         } else {
2586                 device_release_driver(&adev->dev);
2587         }
2588         /*
2589          * Most likely, the device is going away, so put it into D3cold before
2590          * that.
2591          */
2592         acpi_device_set_power(adev, ACPI_STATE_D3_COLD);
2593         adev->flags.initialized = false;
2594         adev->flags.visited = false;
2595 }
2596 EXPORT_SYMBOL_GPL(acpi_bus_trim);
2597
2598 static int acpi_bus_scan_fixed(void)
2599 {
2600         int result = 0;
2601
2602         /*
2603          * Enumerate all fixed-feature devices.
2604          */
2605         if (!(acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON)) {
2606                 struct acpi_device *device = NULL;
2607
2608                 result = acpi_add_single_object(&device, NULL,
2609                                                 ACPI_BUS_TYPE_POWER_BUTTON,
2610                                                 ACPI_STA_DEFAULT);
2611                 if (result)
2612                         return result;
2613
2614                 device->flags.match_driver = true;
2615                 result = device_attach(&device->dev);
2616                 if (result < 0)
2617                         return result;
2618
2619                 device_init_wakeup(&device->dev, true);
2620         }
2621
2622         if (!(acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON)) {
2623                 struct acpi_device *device = NULL;
2624
2625                 result = acpi_add_single_object(&device, NULL,
2626                                                 ACPI_BUS_TYPE_SLEEP_BUTTON,
2627                                                 ACPI_STA_DEFAULT);
2628                 if (result)
2629                         return result;
2630
2631                 device->flags.match_driver = true;
2632                 result = device_attach(&device->dev);
2633         }
2634
2635         return result < 0 ? result : 0;
2636 }
2637
2638 int __init acpi_scan_init(void)
2639 {
2640         int result;
2641
2642         result = bus_register(&acpi_bus_type);
2643         if (result) {
2644                 /* We don't want to quit even if we failed to add suspend/resume */
2645                 printk(KERN_ERR PREFIX "Could not register bus type\n");
2646         }
2647
2648         acpi_pci_root_init();
2649         acpi_pci_link_init();
2650         acpi_processor_init();
2651         acpi_lpss_init();
2652         acpi_apd_init();
2653         acpi_cmos_rtc_init();
2654         acpi_container_init();
2655         acpi_memory_hotplug_init();
2656         acpi_pnp_init();
2657         acpi_int340x_thermal_init();
2658
2659         acpi_scan_add_handler(&generic_device_handler);
2660
2661         mutex_lock(&acpi_scan_lock);
2662         /*
2663          * Enumerate devices in the ACPI namespace.
2664          */
2665         result = acpi_bus_scan(ACPI_ROOT_OBJECT);
2666         if (result)
2667                 goto out;
2668
2669         result = acpi_bus_get_device(ACPI_ROOT_OBJECT, &acpi_root);
2670         if (result)
2671                 goto out;
2672
2673         /* Fixed feature devices do not exist on HW-reduced platform */
2674         if (!acpi_gbl_reduced_hardware) {
2675                 result = acpi_bus_scan_fixed();
2676                 if (result) {
2677                         acpi_detach_data(acpi_root->handle,
2678                                          acpi_scan_drop_device);
2679                         acpi_device_del(acpi_root);
2680                         put_device(&acpi_root->dev);
2681                         goto out;
2682                 }
2683         }
2684
2685         acpi_update_all_gpes();
2686
2687  out:
2688         mutex_unlock(&acpi_scan_lock);
2689         return result;
2690 }