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