git.oblomov.eu Git - linux-2.6/blob - drivers/acpi/acpica/nsxfeval.c

   1 /*******************************************************************************
   2  *
   3  * Module Name: nsxfeval - Public interfaces to the ACPI subsystem
   4  *                         ACPI Object evaluation interfaces
   5  *
   6  ******************************************************************************/
   7
   8 /*
   9  * Copyright (C) 2000 - 2008, Intel Corp.
  10  * All rights reserved.
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions
  14  * are met:
  15  * 1. Redistributions of source code must retain the above copyright
  16  *    notice, this list of conditions, and the following disclaimer,
  17  *    without modification.
  18  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
  19  *    substantially similar to the "NO WARRANTY" disclaimer below
  20  *    ("Disclaimer") and any redistribution must be conditioned upon
  21  *    including a substantially similar Disclaimer requirement for further
  22  *    binary redistribution.
  23  * 3. Neither the names of the above-listed copyright holders nor the names
  24  *    of any contributors may be used to endorse or promote products derived
  25  *    from this software without specific prior written permission.
  26  *
  27  * Alternatively, this software may be distributed under the terms of the
  28  * GNU General Public License ("GPL") version 2 as published by the Free
  29  * Software Foundation.
  30  *
  31  * NO WARRANTY
  32  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  33  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  34  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
  35  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  36  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  37  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  38  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  39  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  40  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  41  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  42  * POSSIBILITY OF SUCH DAMAGES.
  43  */
  44
  45 #include <acpi/acpi.h>
  46 #include "accommon.h"
  47 #include "acnamesp.h"
  48 #include "acinterp.h"
  49
  50 #define _COMPONENT          ACPI_NAMESPACE
  51 ACPI_MODULE_NAME("nsxfeval")
  52
  53 /* Local prototypes */
  54 static void acpi_ns_resolve_references(struct acpi_evaluate_info *info);
  55
  56 /*******************************************************************************
  57  *
  58  * FUNCTION:    acpi_evaluate_object_typed
  59  *
  60  * PARAMETERS:  Handle              - Object handle (optional)
  61  *              Pathname            - Object pathname (optional)
  62  *              external_params     - List of parameters to pass to method,
  63  *                                    terminated by NULL.  May be NULL
  64  *                                    if no parameters are being passed.
  65  *              return_buffer       - Where to put method's return value (if
  66  *                                    any).  If NULL, no value is returned.
  67  *              return_type         - Expected type of return object
  68  *
  69  * RETURN:      Status
  70  *
  71  * DESCRIPTION: Find and evaluate the given object, passing the given
  72  *              parameters if necessary.  One of "Handle" or "Pathname" must
  73  *              be valid (non-null)
  74  *
  75  ******************************************************************************/
  76
  77 acpi_status
  78 acpi_evaluate_object_typed(acpi_handle handle,
  79                            acpi_string pathname,
  80                            struct acpi_object_list *external_params,
  81                            struct acpi_buffer *return_buffer,
  82                            acpi_object_type return_type)
  83 {
  84         acpi_status status;
  85         u8 must_free = FALSE;
  86
  87         ACPI_FUNCTION_TRACE(acpi_evaluate_object_typed);
  88
  89         /* Return buffer must be valid */
  90
  91         if (!return_buffer) {
  92                 return_ACPI_STATUS(AE_BAD_PARAMETER);
  93         }
  94
  95         if (return_buffer->length == ACPI_ALLOCATE_BUFFER) {
  96                 must_free = TRUE;
  97         }
  98
  99         /* Evaluate the object */
 100
 101         status =
 102             acpi_evaluate_object(handle, pathname, external_params,
 103                                  return_buffer);
 104         if (ACPI_FAILURE(status)) {
 105                 return_ACPI_STATUS(status);
 106         }
 107
 108         /* Type ANY means "don't care" */
 109
 110         if (return_type == ACPI_TYPE_ANY) {
 111                 return_ACPI_STATUS(AE_OK);
 112         }
 113
 114         if (return_buffer->length == 0) {
 115
 116                 /* Error because caller specifically asked for a return value */
 117
 118                 ACPI_ERROR((AE_INFO, "No return value"));
 119                 return_ACPI_STATUS(AE_NULL_OBJECT);
 120         }
 121
 122         /* Examine the object type returned from evaluate_object */
 123
 124         if (((union acpi_object *)return_buffer->pointer)->type == return_type) {
 125                 return_ACPI_STATUS(AE_OK);
 126         }
 127
 128         /* Return object type does not match requested type */
 129
 130         ACPI_ERROR((AE_INFO,
 131                     "Incorrect return type [%s] requested [%s]",
 132                     acpi_ut_get_type_name(((union acpi_object *)return_buffer->
 133                                            pointer)->type),
 134                     acpi_ut_get_type_name(return_type)));
 135
 136         if (must_free) {
 137
 138                 /* Caller used ACPI_ALLOCATE_BUFFER, free the return buffer */
 139
 140                 ACPI_FREE(return_buffer->pointer);
 141                 return_buffer->pointer = NULL;
 142         }
 143
 144         return_buffer->length = 0;
 145         return_ACPI_STATUS(AE_TYPE);
 146 }
 147
 148 ACPI_EXPORT_SYMBOL(acpi_evaluate_object_typed)
 149
 150 /*******************************************************************************
 151  *
 152  * FUNCTION:    acpi_evaluate_object
 153  *
 154  * PARAMETERS:  Handle              - Object handle (optional)
 155  *              Pathname            - Object pathname (optional)
 156  *              external_params     - List of parameters to pass to method,
 157  *                                    terminated by NULL.  May be NULL
 158  *                                    if no parameters are being passed.
 159  *              return_buffer       - Where to put method's return value (if
 160  *                                    any).  If NULL, no value is returned.
 161  *
 162  * RETURN:      Status
 163  *
 164  * DESCRIPTION: Find and evaluate the given object, passing the given
 165  *              parameters if necessary.  One of "Handle" or "Pathname" must
 166  *              be valid (non-null)
 167  *
 168  ******************************************************************************/
 169 acpi_status
 170 acpi_evaluate_object(acpi_handle handle,
 171                      acpi_string pathname,
 172                      struct acpi_object_list *external_params,
 173                      struct acpi_buffer *return_buffer)
 174 {
 175         acpi_status status;
 176         struct acpi_evaluate_info *info;
 177         acpi_size buffer_space_needed;
 178         u32 i;
 179
 180         ACPI_FUNCTION_TRACE(acpi_evaluate_object);
 181
 182         /* Allocate and initialize the evaluation information block */
 183
 184         info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
 185         if (!info) {
 186                 return_ACPI_STATUS(AE_NO_MEMORY);
 187         }
 188
 189         info->pathname = pathname;
 190
 191         /* Convert and validate the device handle */
 192
 193         info->prefix_node = acpi_ns_map_handle_to_node(handle);
 194         if (!info->prefix_node) {
 195                 status = AE_BAD_PARAMETER;
 196                 goto cleanup;
 197         }
 198
 199         /*
 200          * If there are parameters to be passed to a control method, the external
 201          * objects must all be converted to internal objects
 202          */
 203         if (external_params && external_params->count) {
 204                 /*
 205                  * Allocate a new parameter block for the internal objects
 206                  * Add 1 to count to allow for null terminated internal list
 207                  */
 208                 info->parameters = ACPI_ALLOCATE_ZEROED(((acpi_size)
 209                                                          external_params->
 210                                                          count +
 211                                                          1) * sizeof(void *));
 212                 if (!info->parameters) {
 213                         status = AE_NO_MEMORY;
 214                         goto cleanup;
 215                 }
 216
 217                 /* Convert each external object in the list to an internal object */
 218
 219                 for (i = 0; i < external_params->count; i++) {
 220                         status =
 221                             acpi_ut_copy_eobject_to_iobject(&external_params->
 222                                                             pointer[i],
 223                                                             &info->
 224                                                             parameters[i]);
 225                         if (ACPI_FAILURE(status)) {
 226                                 goto cleanup;
 227                         }
 228                 }
 229                 info->parameters[external_params->count] = NULL;
 230         }
 231
 232         /*
 233          * Three major cases:
 234          * 1) Fully qualified pathname
 235          * 2) No handle, not fully qualified pathname (error)
 236          * 3) Valid handle
 237          */
 238         if ((pathname) && (acpi_ns_valid_root_prefix(pathname[0]))) {
 239
 240                 /* The path is fully qualified, just evaluate by name */
 241
 242                 info->prefix_node = NULL;
 243                 status = acpi_ns_evaluate(info);
 244         } else if (!handle) {
 245                 /*
 246                  * A handle is optional iff a fully qualified pathname is specified.
 247                  * Since we've already handled fully qualified names above, this is
 248                  * an error
 249                  */
 250                 if (!pathname) {
 251                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 252                                           "Both Handle and Pathname are NULL"));
 253                 } else {
 254                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 255                                           "Null Handle with relative pathname [%s]",
 256                                           pathname));
 257                 }
 258
 259                 status = AE_BAD_PARAMETER;
 260         } else {
 261                 /* We have a namespace a node and a possible relative path */
 262
 263                 status = acpi_ns_evaluate(info);
 264         }
 265
 266         /*
 267          * If we are expecting a return value, and all went well above,
 268          * copy the return value to an external object.
 269          */
 270         if (return_buffer) {
 271                 if (!info->return_object) {
 272                         return_buffer->length = 0;
 273                 } else {
 274                         if (ACPI_GET_DESCRIPTOR_TYPE(info->return_object) ==
 275                             ACPI_DESC_TYPE_NAMED) {
 276                                 /*
 277                                  * If we received a NS Node as a return object, this means that
 278                                  * the object we are evaluating has nothing interesting to
 279                                  * return (such as a mutex, etc.)  We return an error because
 280                                  * these types are essentially unsupported by this interface.
 281                                  * We don't check up front because this makes it easier to add
 282                                  * support for various types at a later date if necessary.
 283                                  */
 284                                 status = AE_TYPE;
 285                                 info->return_object = NULL;     /* No need to delete a NS Node */
 286                                 return_buffer->length = 0;
 287                         }
 288
 289                         if (ACPI_SUCCESS(status)) {
 290
 291                                 /* Dereference Index and ref_of references */
 292
 293                                 acpi_ns_resolve_references(info);
 294
 295                                 /* Get the size of the returned object */
 296
 297                                 status =
 298                                     acpi_ut_get_object_size(info->return_object,
 299                                                             &buffer_space_needed);
 300                                 if (ACPI_SUCCESS(status)) {
 301
 302                                         /* Validate/Allocate/Clear caller buffer */
 303
 304                                         status =
 305                                             acpi_ut_initialize_buffer
 306                                             (return_buffer,
 307                                              buffer_space_needed);
 308                                         if (ACPI_FAILURE(status)) {
 309                                                 /*
 310                                                  * Caller's buffer is too small or a new one can't
 311                                                  * be allocated
 312                                                  */
 313                                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 314                                                                   "Needed buffer size %X, %s\n",
 315                                                                   (u32)
 316                                                                   buffer_space_needed,
 317                                                                   acpi_format_exception
 318                                                                   (status)));
 319                                         } else {
 320                                                 /* We have enough space for the object, build it */
 321
 322                                                 status =
 323                                                     acpi_ut_copy_iobject_to_eobject
 324                                                     (info->return_object,
 325                                                      return_buffer);
 326                                         }
 327                                 }
 328                         }
 329                 }
 330         }
 331
 332         if (info->return_object) {
 333                 /*
 334                  * Delete the internal return object. NOTE: Interpreter must be
 335                  * locked to avoid race condition.
 336                  */
 337                 acpi_ex_enter_interpreter();
 338
 339                 /* Remove one reference on the return object (should delete it) */
 340
 341                 acpi_ut_remove_reference(info->return_object);
 342                 acpi_ex_exit_interpreter();
 343         }
 344
 345       cleanup:
 346
 347         /* Free the input parameter list (if we created one) */
 348
 349         if (info->parameters) {
 350
 351                 /* Free the allocated parameter block */
 352
 353                 acpi_ut_delete_internal_object_list(info->parameters);
 354         }
 355
 356         ACPI_FREE(info);
 357         return_ACPI_STATUS(status);
 358 }
 359
 360 ACPI_EXPORT_SYMBOL(acpi_evaluate_object)
 361
 362 /*******************************************************************************
 363  *
 364  * FUNCTION:    acpi_ns_resolve_references
 365  *
 366  * PARAMETERS:  Info                    - Evaluation info block
 367  *
 368  * RETURN:      Info->return_object is replaced with the dereferenced object
 369  *
 370  * DESCRIPTION: Dereference certain reference objects. Called before an
 371  *              internal return object is converted to an external union acpi_object.
 372  *
 373  * Performs an automatic dereference of Index and ref_of reference objects.
 374  * These reference objects are not supported by the union acpi_object, so this is a
 375  * last resort effort to return something useful. Also, provides compatibility
 376  * with other ACPI implementations.
 377  *
 378  * NOTE: does not handle references within returned package objects or nested
 379  * references, but this support could be added later if found to be necessary.
 380  *
 381  ******************************************************************************/
 382 static void acpi_ns_resolve_references(struct acpi_evaluate_info *info)
 383 {
 384         union acpi_operand_object *obj_desc = NULL;
 385         struct acpi_namespace_node *node;
 386
 387         /* We are interested in reference objects only */
 388
 389         if ((info->return_object)->common.type != ACPI_TYPE_LOCAL_REFERENCE) {
 390                 return;
 391         }
 392
 393         /*
 394          * Two types of references are supported - those created by Index and
 395          * ref_of operators. A name reference (AML_NAMEPATH_OP) can be converted
 396          * to an union acpi_object, so it is not dereferenced here. A ddb_handle
 397          * (AML_LOAD_OP) cannot be dereferenced, nor can it be converted to
 398          * an union acpi_object.
 399          */
 400         switch (info->return_object->reference.class) {
 401         case ACPI_REFCLASS_INDEX:
 402
 403                 obj_desc = *(info->return_object->reference.where);
 404                 break;
 405
 406         case ACPI_REFCLASS_REFOF:
 407
 408                 node = info->return_object->reference.object;
 409                 if (node) {
 410                         obj_desc = node->object;
 411                 }
 412                 break;
 413
 414         default:
 415                 return;
 416         }
 417
 418         /* Replace the existing reference object */
 419
 420         if (obj_desc) {
 421                 acpi_ut_add_reference(obj_desc);
 422                 acpi_ut_remove_reference(info->return_object);
 423                 info->return_object = obj_desc;
 424         }
 425
 426         return;
 427 }
 428
 429 /*******************************************************************************
 430  *
 431  * FUNCTION:    acpi_walk_namespace
 432  *
 433  * PARAMETERS:  Type                - acpi_object_type to search for
 434  *              start_object        - Handle in namespace where search begins
 435  *              max_depth           - Depth to which search is to reach
 436  *              user_function       - Called when an object of "Type" is found
 437  *              Context             - Passed to user function
 438  *              return_value        - Location where return value of
 439  *                                    user_function is put if terminated early
 440  *
 441  * RETURNS      Return value from the user_function if terminated early.
 442  *              Otherwise, returns NULL.
 443  *
 444  * DESCRIPTION: Performs a modified depth-first walk of the namespace tree,
 445  *              starting (and ending) at the object specified by start_handle.
 446  *              The user_function is called whenever an object that matches
 447  *              the type parameter is found.  If the user function returns
 448  *              a non-zero value, the search is terminated immediately and this
 449  *              value is returned to the caller.
 450  *
 451  *              The point of this procedure is to provide a generic namespace
 452  *              walk routine that can be called from multiple places to
 453  *              provide multiple services;  the User Function can be tailored
 454  *              to each task, whether it is a print function, a compare
 455  *              function, etc.
 456  *
 457  ******************************************************************************/
 458
 459 acpi_status
 460 acpi_walk_namespace(acpi_object_type type,
 461                     acpi_handle start_object,
 462                     u32 max_depth,
 463                     acpi_walk_callback user_function,
 464                     void *context, void **return_value)
 465 {
 466         acpi_status status;
 467
 468         ACPI_FUNCTION_TRACE(acpi_walk_namespace);
 469
 470         /* Parameter validation */
 471
 472         if ((type > ACPI_TYPE_LOCAL_MAX) || (!max_depth) || (!user_function)) {
 473                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 474         }
 475
 476         /*
 477          * Need to acquire the namespace reader lock to prevent interference
 478          * with any concurrent table unloads (which causes the deletion of
 479          * namespace objects). We cannot allow the deletion of a namespace node
 480          * while the user function is using it. The exception to this are the
 481          * nodes created and deleted during control method execution -- these
 482          * nodes are marked as temporary nodes and are ignored by the namespace
 483          * walk. Thus, control methods can be executed while holding the
 484          * namespace deletion lock (and the user function can execute control
 485          * methods.)
 486          */
 487         status = acpi_ut_acquire_read_lock(&acpi_gbl_namespace_rw_lock);
 488         if (ACPI_FAILURE(status)) {
 489                 return status;
 490         }
 491
 492         /*
 493          * Lock the namespace around the walk. The namespace will be
 494          * unlocked/locked around each call to the user function - since the user
 495          * function must be allowed to make ACPICA calls itself (for example, it
 496          * will typically execute control methods during device enumeration.)
 497          */
 498         status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
 499         if (ACPI_FAILURE(status)) {
 500                 goto unlock_and_exit;
 501         }
 502
 503         status = acpi_ns_walk_namespace(type, start_object, max_depth,
 504                                         ACPI_NS_WALK_UNLOCK, user_function,
 505                                         context, return_value);
 506
 507         (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
 508
 509       unlock_and_exit:
 510         (void)acpi_ut_release_read_lock(&acpi_gbl_namespace_rw_lock);
 511         return_ACPI_STATUS(status);
 512 }
 513
 514 ACPI_EXPORT_SYMBOL(acpi_walk_namespace)
 515
 516 /*******************************************************************************
 517  *
 518  * FUNCTION:    acpi_ns_get_device_callback
 519  *
 520  * PARAMETERS:  Callback from acpi_get_device
 521  *
 522  * RETURN:      Status
 523  *
 524  * DESCRIPTION: Takes callbacks from walk_namespace and filters out all non-
 525  *              present devices, or if they specified a HID, it filters based
 526  *              on that.
 527  *
 528  ******************************************************************************/
 529 static acpi_status
 530 acpi_ns_get_device_callback(acpi_handle obj_handle,
 531                             u32 nesting_level,
 532                             void *context, void **return_value)
 533 {
 534         struct acpi_get_devices_info *info = context;
 535         acpi_status status;
 536         struct acpi_namespace_node *node;
 537         u32 flags;
 538         struct acpica_device_id hid;
 539         struct acpi_compatible_id_list *cid;
 540         u32 i;
 541         int found;
 542
 543         status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
 544         if (ACPI_FAILURE(status)) {
 545                 return (status);
 546         }
 547
 548         node = acpi_ns_map_handle_to_node(obj_handle);
 549         status = acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
 550         if (ACPI_FAILURE(status)) {
 551                 return (status);
 552         }
 553
 554         if (!node) {
 555                 return (AE_BAD_PARAMETER);
 556         }
 557
 558         /* Run _STA to determine if device is present */
 559
 560         status = acpi_ut_execute_STA(node, &flags);
 561         if (ACPI_FAILURE(status)) {
 562                 return (AE_CTRL_DEPTH);
 563         }
 564
 565         if (!(flags & ACPI_STA_DEVICE_PRESENT) &&
 566             !(flags & ACPI_STA_DEVICE_FUNCTIONING)) {
 567                 /*
 568                  * Don't examine the children of the device only when the
 569                  * device is neither present nor functional. See ACPI spec,
 570                  * description of _STA for more information.
 571                  */
 572                 return (AE_CTRL_DEPTH);
 573         }
 574
 575         /* Filter based on device HID & CID */
 576
 577         if (info->hid != NULL) {
 578                 status = acpi_ut_execute_HID(node, &hid);
 579                 if (status == AE_NOT_FOUND) {
 580                         return (AE_OK);
 581                 } else if (ACPI_FAILURE(status)) {
 582                         return (AE_CTRL_DEPTH);
 583                 }
 584
 585                 if (ACPI_STRNCMP(hid.value, info->hid, sizeof(hid.value)) != 0) {
 586
 587                         /* Get the list of Compatible IDs */
 588
 589                         status = acpi_ut_execute_CID(node, &cid);
 590                         if (status == AE_NOT_FOUND) {
 591                                 return (AE_OK);
 592                         } else if (ACPI_FAILURE(status)) {
 593                                 return (AE_CTRL_DEPTH);
 594                         }
 595
 596                         /* Walk the CID list */
 597
 598                         found = 0;
 599                         for (i = 0; i < cid->count; i++) {
 600                                 if (ACPI_STRNCMP(cid->id[i].value, info->hid,
 601                                                  sizeof(struct
 602                                                         acpi_compatible_id)) ==
 603                                     0) {
 604                                         found = 1;
 605                                         break;
 606                                 }
 607                         }
 608                         ACPI_FREE(cid);
 609                         if (!found)
 610                                 return (AE_OK);
 611                 }
 612         }
 613
 614         status = info->user_function(obj_handle, nesting_level, info->context,
 615                                      return_value);
 616         return (status);
 617 }
 618
 619 /*******************************************************************************
 620  *
 621  * FUNCTION:    acpi_get_devices
 622  *
 623  * PARAMETERS:  HID                 - HID to search for. Can be NULL.
 624  *              user_function       - Called when a matching object is found
 625  *              Context             - Passed to user function
 626  *              return_value        - Location where return value of
 627  *                                    user_function is put if terminated early
 628  *
 629  * RETURNS      Return value from the user_function if terminated early.
 630  *              Otherwise, returns NULL.
 631  *
 632  * DESCRIPTION: Performs a modified depth-first walk of the namespace tree,
 633  *              starting (and ending) at the object specified by start_handle.
 634  *              The user_function is called whenever an object of type
 635  *              Device is found.  If the user function returns
 636  *              a non-zero value, the search is terminated immediately and this
 637  *              value is returned to the caller.
 638  *
 639  *              This is a wrapper for walk_namespace, but the callback performs
 640  *              additional filtering. Please see acpi_ns_get_device_callback.
 641  *
 642  ******************************************************************************/
 643
 644 acpi_status
 645 acpi_get_devices(const char *HID,
 646                  acpi_walk_callback user_function,
 647                  void *context, void **return_value)
 648 {
 649         acpi_status status;
 650         struct acpi_get_devices_info info;
 651
 652         ACPI_FUNCTION_TRACE(acpi_get_devices);
 653
 654         /* Parameter validation */
 655
 656         if (!user_function) {
 657                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 658         }
 659
 660         /*
 661          * We're going to call their callback from OUR callback, so we need
 662          * to know what it is, and their context parameter.
 663          */
 664         info.hid = HID;
 665         info.context = context;
 666         info.user_function = user_function;
 667
 668         /*
 669          * Lock the namespace around the walk.
 670          * The namespace will be unlocked/locked around each call
 671          * to the user function - since this function
 672          * must be allowed to make Acpi calls itself.
 673          */
 674         status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
 675         if (ACPI_FAILURE(status)) {
 676                 return_ACPI_STATUS(status);
 677         }
 678
 679         status = acpi_ns_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 680                                         ACPI_UINT32_MAX, ACPI_NS_WALK_UNLOCK,
 681                                         acpi_ns_get_device_callback, &info,
 682                                         return_value);
 683
 684         (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
 685         return_ACPI_STATUS(status);
 686 }
 687
 688 ACPI_EXPORT_SYMBOL(acpi_get_devices)
 689
 690 /*******************************************************************************
 691  *
 692  * FUNCTION:    acpi_attach_data
 693  *
 694  * PARAMETERS:  obj_handle          - Namespace node
 695  *              Handler             - Handler for this attachment
 696  *              Data                - Pointer to data to be attached
 697  *
 698  * RETURN:      Status
 699  *
 700  * DESCRIPTION: Attach arbitrary data and handler to a namespace node.
 701  *
 702  ******************************************************************************/
 703 acpi_status
 704 acpi_attach_data(acpi_handle obj_handle,
 705                  acpi_object_handler handler, void *data)
 706 {
 707         struct acpi_namespace_node *node;
 708         acpi_status status;
 709
 710         /* Parameter validation */
 711
 712         if (!obj_handle || !handler || !data) {
 713                 return (AE_BAD_PARAMETER);
 714         }
 715
 716         status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
 717         if (ACPI_FAILURE(status)) {
 718                 return (status);
 719         }
 720
 721         /* Convert and validate the handle */
 722
 723         node = acpi_ns_map_handle_to_node(obj_handle);
 724         if (!node) {
 725                 status = AE_BAD_PARAMETER;
 726                 goto unlock_and_exit;
 727         }
 728
 729         status = acpi_ns_attach_data(node, handler, data);
 730
 731       unlock_and_exit:
 732         (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
 733         return (status);
 734 }
 735
 736 ACPI_EXPORT_SYMBOL(acpi_attach_data)
 737
 738 /*******************************************************************************
 739  *
 740  * FUNCTION:    acpi_detach_data
 741  *
 742  * PARAMETERS:  obj_handle          - Namespace node handle
 743  *              Handler             - Handler used in call to acpi_attach_data
 744  *
 745  * RETURN:      Status
 746  *
 747  * DESCRIPTION: Remove data that was previously attached to a node.
 748  *
 749  ******************************************************************************/
 750 acpi_status
 751 acpi_detach_data(acpi_handle obj_handle, acpi_object_handler handler)
 752 {
 753         struct acpi_namespace_node *node;
 754         acpi_status status;
 755
 756         /* Parameter validation */
 757
 758         if (!obj_handle || !handler) {
 759                 return (AE_BAD_PARAMETER);
 760         }
 761
 762         status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
 763         if (ACPI_FAILURE(status)) {
 764                 return (status);
 765         }
 766
 767         /* Convert and validate the handle */
 768
 769         node = acpi_ns_map_handle_to_node(obj_handle);
 770         if (!node) {
 771                 status = AE_BAD_PARAMETER;
 772                 goto unlock_and_exit;
 773         }
 774
 775         status = acpi_ns_detach_data(node, handler);
 776
 777       unlock_and_exit:
 778         (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
 779         return (status);
 780 }
 781
 782 ACPI_EXPORT_SYMBOL(acpi_detach_data)
 783
 784 /*******************************************************************************
 785  *
 786  * FUNCTION:    acpi_get_data
 787  *
 788  * PARAMETERS:  obj_handle          - Namespace node
 789  *              Handler             - Handler used in call to attach_data
 790  *              Data                - Where the data is returned
 791  *
 792  * RETURN:      Status
 793  *
 794  * DESCRIPTION: Retrieve data that was previously attached to a namespace node.
 795  *
 796  ******************************************************************************/
 797 acpi_status
 798 acpi_get_data(acpi_handle obj_handle, acpi_object_handler handler, void **data)
 799 {
 800         struct acpi_namespace_node *node;
 801         acpi_status status;
 802
 803         /* Parameter validation */
 804
 805         if (!obj_handle || !handler || !data) {
 806                 return (AE_BAD_PARAMETER);
 807         }
 808
 809         status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
 810         if (ACPI_FAILURE(status)) {
 811                 return (status);
 812         }
 813
 814         /* Convert and validate the handle */
 815
 816         node = acpi_ns_map_handle_to_node(obj_handle);
 817         if (!node) {
 818                 status = AE_BAD_PARAMETER;
 819                 goto unlock_and_exit;
 820         }
 821
 822         status = acpi_ns_get_attached_data(node, handler, data);
 823
 824       unlock_and_exit:
 825         (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
 826         return (status);
 827 }
 828
 829 ACPI_EXPORT_SYMBOL(acpi_get_data)