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 - 2011, 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_validate_handle(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  *              pre_order_visit     - Called during tree pre-order visit
 437  *                                    when an object of "Type" is found
 438  *              post_order_visit    - Called during tree post-order visit
 439  *                                    when an object of "Type" is found
 440  *              Context             - Passed to user function(s) above
 441  *              return_value        - Location where return value of
 442  *                                    user_function is put if terminated early
 443  *
 444  * RETURNS      Return value from the user_function if terminated early.
 445  *              Otherwise, returns NULL.
 446  *
 447  * DESCRIPTION: Performs a modified depth-first walk of the namespace tree,
 448  *              starting (and ending) at the object specified by start_handle.
 449  *              The callback function is called whenever an object that matches
 450  *              the type parameter is found. If the callback function returns
 451  *              a non-zero value, the search is terminated immediately and this
 452  *              value is returned to the caller.
 453  *
 454  *              The point of this procedure is to provide a generic namespace
 455  *              walk routine that can be called from multiple places to
 456  *              provide multiple services; the callback function(s) can be
 457  *              tailored to each task, whether it is a print function,
 458  *              a compare function, etc.
 459  *
 460  ******************************************************************************/
 461
 462 acpi_status
 463 acpi_walk_namespace(acpi_object_type type,
 464                     acpi_handle start_object,
 465                     u32 max_depth,
 466                     acpi_walk_callback pre_order_visit,
 467                     acpi_walk_callback post_order_visit,
 468                     void *context, void **return_value)
 469 {
 470         acpi_status status;
 471
 472         ACPI_FUNCTION_TRACE(acpi_walk_namespace);
 473
 474         /* Parameter validation */
 475
 476         if ((type > ACPI_TYPE_LOCAL_MAX) ||
 477             (!max_depth) || (!pre_order_visit && !post_order_visit)) {
 478                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 479         }
 480
 481         /*
 482          * Need to acquire the namespace reader lock to prevent interference
 483          * with any concurrent table unloads (which causes the deletion of
 484          * namespace objects). We cannot allow the deletion of a namespace node
 485          * while the user function is using it. The exception to this are the
 486          * nodes created and deleted during control method execution -- these
 487          * nodes are marked as temporary nodes and are ignored by the namespace
 488          * walk. Thus, control methods can be executed while holding the
 489          * namespace deletion lock (and the user function can execute control
 490          * methods.)
 491          */
 492         status = acpi_ut_acquire_read_lock(&acpi_gbl_namespace_rw_lock);
 493         if (ACPI_FAILURE(status)) {
 494                 return status;
 495         }
 496
 497         /*
 498          * Lock the namespace around the walk. The namespace will be
 499          * unlocked/locked around each call to the user function - since the user
 500          * function must be allowed to make ACPICA calls itself (for example, it
 501          * will typically execute control methods during device enumeration.)
 502          */
 503         status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
 504         if (ACPI_FAILURE(status)) {
 505                 goto unlock_and_exit;
 506         }
 507
 508         status = acpi_ns_walk_namespace(type, start_object, max_depth,
 509                                         ACPI_NS_WALK_UNLOCK, pre_order_visit,
 510                                         post_order_visit, context,
 511                                         return_value);
 512
 513         (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
 514
 515       unlock_and_exit:
 516         (void)acpi_ut_release_read_lock(&acpi_gbl_namespace_rw_lock);
 517         return_ACPI_STATUS(status);
 518 }
 519
 520 ACPI_EXPORT_SYMBOL(acpi_walk_namespace)
 521
 522 /*******************************************************************************
 523  *
 524  * FUNCTION:    acpi_ns_get_device_callback
 525  *
 526  * PARAMETERS:  Callback from acpi_get_device
 527  *
 528  * RETURN:      Status
 529  *
 530  * DESCRIPTION: Takes callbacks from walk_namespace and filters out all non-
 531  *              present devices, or if they specified a HID, it filters based
 532  *              on that.
 533  *
 534  ******************************************************************************/
 535 static acpi_status
 536 acpi_ns_get_device_callback(acpi_handle obj_handle,
 537                             u32 nesting_level,
 538                             void *context, void **return_value)
 539 {
 540         struct acpi_get_devices_info *info = context;
 541         acpi_status status;
 542         struct acpi_namespace_node *node;
 543         u32 flags;
 544         struct acpica_device_id *hid;
 545         struct acpica_device_id_list *cid;
 546         u32 i;
 547         u8 found;
 548         int no_match;
 549
 550         status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
 551         if (ACPI_FAILURE(status)) {
 552                 return (status);
 553         }
 554
 555         node = acpi_ns_validate_handle(obj_handle);
 556         status = acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
 557         if (ACPI_FAILURE(status)) {
 558                 return (status);
 559         }
 560
 561         if (!node) {
 562                 return (AE_BAD_PARAMETER);
 563         }
 564
 565         /*
 566          * First, filter based on the device HID and CID.
 567          *
 568          * 01/2010: For this case where a specific HID is requested, we don't
 569          * want to run _STA until we have an actual HID match. Thus, we will
 570          * not unnecessarily execute _STA on devices for which the caller
 571          * doesn't care about. Previously, _STA was executed unconditionally
 572          * on all devices found here.
 573          *
 574          * A side-effect of this change is that now we will continue to search
 575          * for a matching HID even under device trees where the parent device
 576          * would have returned a _STA that indicates it is not present or
 577          * not functioning (thus aborting the search on that branch).
 578          */
 579         if (info->hid != NULL) {
 580                 status = acpi_ut_execute_HID(node, &hid);
 581                 if (status == AE_NOT_FOUND) {
 582                         return (AE_OK);
 583                 } else if (ACPI_FAILURE(status)) {
 584                         return (AE_CTRL_DEPTH);
 585                 }
 586
 587                 no_match = ACPI_STRCMP(hid->string, info->hid);
 588                 ACPI_FREE(hid);
 589
 590                 if (no_match) {
 591                         /*
 592                          * HID does not match, attempt match within the
 593                          * list of Compatible IDs (CIDs)
 594                          */
 595                         status = acpi_ut_execute_CID(node, &cid);
 596                         if (status == AE_NOT_FOUND) {
 597                                 return (AE_OK);
 598                         } else if (ACPI_FAILURE(status)) {
 599                                 return (AE_CTRL_DEPTH);
 600                         }
 601
 602                         /* Walk the CID list */
 603
 604                         found = 0;
 605                         for (i = 0; i < cid->count; i++) {
 606                                 if (ACPI_STRCMP(cid->ids[i].string, info->hid)
 607                                     == 0) {
 608                                         found = 1;
 609                                         break;
 610                                 }
 611                         }
 612                         ACPI_FREE(cid);
 613                         if (!found)
 614                                 return (AE_OK);
 615                 }
 616         }
 617
 618         /* Run _STA to determine if device is present */
 619
 620         status = acpi_ut_execute_STA(node, &flags);
 621         if (ACPI_FAILURE(status)) {
 622                 return (AE_CTRL_DEPTH);
 623         }
 624
 625         if (!(flags & ACPI_STA_DEVICE_PRESENT) &&
 626             !(flags & ACPI_STA_DEVICE_FUNCTIONING)) {
 627                 /*
 628                  * Don't examine the children of the device only when the
 629                  * device is neither present nor functional. See ACPI spec,
 630                  * description of _STA for more information.
 631                  */
 632                 return (AE_CTRL_DEPTH);
 633         }
 634
 635         /* We have a valid device, invoke the user function */
 636
 637         status = info->user_function(obj_handle, nesting_level, info->context,
 638                                      return_value);
 639         return (status);
 640 }
 641
 642 /*******************************************************************************
 643  *
 644  * FUNCTION:    acpi_get_devices
 645  *
 646  * PARAMETERS:  HID                 - HID to search for. Can be NULL.
 647  *              user_function       - Called when a matching object is found
 648  *              Context             - Passed to user function
 649  *              return_value        - Location where return value of
 650  *                                    user_function is put if terminated early
 651  *
 652  * RETURNS      Return value from the user_function if terminated early.
 653  *              Otherwise, returns NULL.
 654  *
 655  * DESCRIPTION: Performs a modified depth-first walk of the namespace tree,
 656  *              starting (and ending) at the object specified by start_handle.
 657  *              The user_function is called whenever an object of type
 658  *              Device is found.  If the user function returns
 659  *              a non-zero value, the search is terminated immediately and this
 660  *              value is returned to the caller.
 661  *
 662  *              This is a wrapper for walk_namespace, but the callback performs
 663  *              additional filtering. Please see acpi_ns_get_device_callback.
 664  *
 665  ******************************************************************************/
 666
 667 acpi_status
 668 acpi_get_devices(const char *HID,
 669                  acpi_walk_callback user_function,
 670                  void *context, void **return_value)
 671 {
 672         acpi_status status;
 673         struct acpi_get_devices_info info;
 674
 675         ACPI_FUNCTION_TRACE(acpi_get_devices);
 676
 677         /* Parameter validation */
 678
 679         if (!user_function) {
 680                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 681         }
 682
 683         /*
 684          * We're going to call their callback from OUR callback, so we need
 685          * to know what it is, and their context parameter.
 686          */
 687         info.hid = HID;
 688         info.context = context;
 689         info.user_function = user_function;
 690
 691         /*
 692          * Lock the namespace around the walk.
 693          * The namespace will be unlocked/locked around each call
 694          * to the user function - since this function
 695          * must be allowed to make Acpi calls itself.
 696          */
 697         status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
 698         if (ACPI_FAILURE(status)) {
 699                 return_ACPI_STATUS(status);
 700         }
 701
 702         status = acpi_ns_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 703                                         ACPI_UINT32_MAX, ACPI_NS_WALK_UNLOCK,
 704                                         acpi_ns_get_device_callback, NULL,
 705                                         &info, return_value);
 706
 707         (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
 708         return_ACPI_STATUS(status);
 709 }
 710
 711 ACPI_EXPORT_SYMBOL(acpi_get_devices)
 712
 713 /*******************************************************************************
 714  *
 715  * FUNCTION:    acpi_attach_data
 716  *
 717  * PARAMETERS:  obj_handle          - Namespace node
 718  *              Handler             - Handler for this attachment
 719  *              Data                - Pointer to data to be attached
 720  *
 721  * RETURN:      Status
 722  *
 723  * DESCRIPTION: Attach arbitrary data and handler to a namespace node.
 724  *
 725  ******************************************************************************/
 726 acpi_status
 727 acpi_attach_data(acpi_handle obj_handle,
 728                  acpi_object_handler handler, void *data)
 729 {
 730         struct acpi_namespace_node *node;
 731         acpi_status status;
 732
 733         /* Parameter validation */
 734
 735         if (!obj_handle || !handler || !data) {
 736                 return (AE_BAD_PARAMETER);
 737         }
 738
 739         status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
 740         if (ACPI_FAILURE(status)) {
 741                 return (status);
 742         }
 743
 744         /* Convert and validate the handle */
 745
 746         node = acpi_ns_validate_handle(obj_handle);
 747         if (!node) {
 748                 status = AE_BAD_PARAMETER;
 749                 goto unlock_and_exit;
 750         }
 751
 752         status = acpi_ns_attach_data(node, handler, data);
 753
 754       unlock_and_exit:
 755         (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
 756         return (status);
 757 }
 758
 759 ACPI_EXPORT_SYMBOL(acpi_attach_data)
 760
 761 /*******************************************************************************
 762  *
 763  * FUNCTION:    acpi_detach_data
 764  *
 765  * PARAMETERS:  obj_handle          - Namespace node handle
 766  *              Handler             - Handler used in call to acpi_attach_data
 767  *
 768  * RETURN:      Status
 769  *
 770  * DESCRIPTION: Remove data that was previously attached to a node.
 771  *
 772  ******************************************************************************/
 773 acpi_status
 774 acpi_detach_data(acpi_handle obj_handle, acpi_object_handler handler)
 775 {
 776         struct acpi_namespace_node *node;
 777         acpi_status status;
 778
 779         /* Parameter validation */
 780
 781         if (!obj_handle || !handler) {
 782                 return (AE_BAD_PARAMETER);
 783         }
 784
 785         status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
 786         if (ACPI_FAILURE(status)) {
 787                 return (status);
 788         }
 789
 790         /* Convert and validate the handle */
 791
 792         node = acpi_ns_validate_handle(obj_handle);
 793         if (!node) {
 794                 status = AE_BAD_PARAMETER;
 795                 goto unlock_and_exit;
 796         }
 797
 798         status = acpi_ns_detach_data(node, handler);
 799
 800       unlock_and_exit:
 801         (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
 802         return (status);
 803 }
 804
 805 ACPI_EXPORT_SYMBOL(acpi_detach_data)
 806
 807 /*******************************************************************************
 808  *
 809  * FUNCTION:    acpi_get_data
 810  *
 811  * PARAMETERS:  obj_handle          - Namespace node
 812  *              Handler             - Handler used in call to attach_data
 813  *              Data                - Where the data is returned
 814  *
 815  * RETURN:      Status
 816  *
 817  * DESCRIPTION: Retrieve data that was previously attached to a namespace node.
 818  *
 819  ******************************************************************************/
 820 acpi_status
 821 acpi_get_data(acpi_handle obj_handle, acpi_object_handler handler, void **data)
 822 {
 823         struct acpi_namespace_node *node;
 824         acpi_status status;
 825
 826         /* Parameter validation */
 827
 828         if (!obj_handle || !handler || !data) {
 829                 return (AE_BAD_PARAMETER);
 830         }
 831
 832         status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
 833         if (ACPI_FAILURE(status)) {
 834                 return (status);
 835         }
 836
 837         /* Convert and validate the handle */
 838
 839         node = acpi_ns_validate_handle(obj_handle);
 840         if (!node) {
 841                 status = AE_BAD_PARAMETER;
 842                 goto unlock_and_exit;
 843         }
 844
 845         status = acpi_ns_get_attached_data(node, handler, data);
 846
 847       unlock_and_exit:
 848         (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
 849         return (status);
 850 }
 851
 852 ACPI_EXPORT_SYMBOL(acpi_get_data)