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 - 2012, 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 <linux/export.h>
  46 #include <acpi/acpi.h>
  47 #include "accommon.h"
  48 #include "acnamesp.h"
  49 #include "acinterp.h"
  50
  51 #define _COMPONENT          ACPI_NAMESPACE
  52 ACPI_MODULE_NAME("nsxfeval")
  53
  54 /* Local prototypes */
  55 static void acpi_ns_resolve_references(struct acpi_evaluate_info *info);
  56
  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
 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_validate_handle(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  *              pre_order_visit     - Called during tree pre-order visit
 438  *                                    when an object of "Type" is found
 439  *              post_order_visit    - Called during tree post-order visit
 440  *                                    when an object of "Type" is found
 441  *              Context             - Passed to user function(s) above
 442  *              return_value        - Location where return value of
 443  *                                    user_function is put if terminated early
 444  *
 445  * RETURNS      Return value from the user_function if terminated early.
 446  *              Otherwise, returns NULL.
 447  *
 448  * DESCRIPTION: Performs a modified depth-first walk of the namespace tree,
 449  *              starting (and ending) at the object specified by start_handle.
 450  *              The callback function is called whenever an object that matches
 451  *              the type parameter is found. If the callback function returns
 452  *              a non-zero value, the search is terminated immediately and this
 453  *              value is returned to the caller.
 454  *
 455  *              The point of this procedure is to provide a generic namespace
 456  *              walk routine that can be called from multiple places to
 457  *              provide multiple services; the callback function(s) can be
 458  *              tailored to each task, whether it is a print function,
 459  *              a compare function, etc.
 460  *
 461  ******************************************************************************/
 462
 463 acpi_status
 464 acpi_walk_namespace(acpi_object_type type,
 465                     acpi_handle start_object,
 466                     u32 max_depth,
 467                     acpi_walk_callback pre_order_visit,
 468                     acpi_walk_callback post_order_visit,
 469                     void *context, void **return_value)
 470 {
 471         acpi_status status;
 472
 473         ACPI_FUNCTION_TRACE(acpi_walk_namespace);
 474
 475         /* Parameter validation */
 476
 477         if ((type > ACPI_TYPE_LOCAL_MAX) ||
 478             (!max_depth) || (!pre_order_visit && !post_order_visit)) {
 479                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 480         }
 481
 482         /*
 483          * Need to acquire the namespace reader lock to prevent interference
 484          * with any concurrent table unloads (which causes the deletion of
 485          * namespace objects). We cannot allow the deletion of a namespace node
 486          * while the user function is using it. The exception to this are the
 487          * nodes created and deleted during control method execution -- these
 488          * nodes are marked as temporary nodes and are ignored by the namespace
 489          * walk. Thus, control methods can be executed while holding the
 490          * namespace deletion lock (and the user function can execute control
 491          * methods.)
 492          */
 493         status = acpi_ut_acquire_read_lock(&acpi_gbl_namespace_rw_lock);
 494         if (ACPI_FAILURE(status)) {
 495                 return status;
 496         }
 497
 498         /*
 499          * Lock the namespace around the walk. The namespace will be
 500          * unlocked/locked around each call to the user function - since the user
 501          * function must be allowed to make ACPICA calls itself (for example, it
 502          * will typically execute control methods during device enumeration.)
 503          */
 504         status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
 505         if (ACPI_FAILURE(status)) {
 506                 goto unlock_and_exit;
 507         }
 508
 509         status = acpi_ns_walk_namespace(type, start_object, max_depth,
 510                                         ACPI_NS_WALK_UNLOCK, pre_order_visit,
 511                                         post_order_visit, context,
 512                                         return_value);
 513
 514         (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
 515
 516       unlock_and_exit:
 517         (void)acpi_ut_release_read_lock(&acpi_gbl_namespace_rw_lock);
 518         return_ACPI_STATUS(status);
 519 }
 520
 521 ACPI_EXPORT_SYMBOL(acpi_walk_namespace)
 522
 523 /*******************************************************************************
 524  *
 525  * FUNCTION:    acpi_ns_get_device_callback
 526  *
 527  * PARAMETERS:  Callback from acpi_get_device
 528  *
 529  * RETURN:      Status
 530  *
 531  * DESCRIPTION: Takes callbacks from walk_namespace and filters out all non-
 532  *              present devices, or if they specified a HID, it filters based
 533  *              on that.
 534  *
 535  ******************************************************************************/
 536 static acpi_status
 537 acpi_ns_get_device_callback(acpi_handle obj_handle,
 538                             u32 nesting_level,
 539                             void *context, void **return_value)
 540 {
 541         struct acpi_get_devices_info *info = context;
 542         acpi_status status;
 543         struct acpi_namespace_node *node;
 544         u32 flags;
 545         struct acpica_device_id *hid;
 546         struct acpica_device_id_list *cid;
 547         u32 i;
 548         u8 found;
 549         int no_match;
 550
 551         status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
 552         if (ACPI_FAILURE(status)) {
 553                 return (status);
 554         }
 555
 556         node = acpi_ns_validate_handle(obj_handle);
 557         status = acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
 558         if (ACPI_FAILURE(status)) {
 559                 return (status);
 560         }
 561
 562         if (!node) {
 563                 return (AE_BAD_PARAMETER);
 564         }
 565
 566         /*
 567          * First, filter based on the device HID and CID.
 568          *
 569          * 01/2010: For this case where a specific HID is requested, we don't
 570          * want to run _STA until we have an actual HID match. Thus, we will
 571          * not unnecessarily execute _STA on devices for which the caller
 572          * doesn't care about. Previously, _STA was executed unconditionally
 573          * on all devices found here.
 574          *
 575          * A side-effect of this change is that now we will continue to search
 576          * for a matching HID even under device trees where the parent device
 577          * would have returned a _STA that indicates it is not present or
 578          * not functioning (thus aborting the search on that branch).
 579          */
 580         if (info->hid != NULL) {
 581                 status = acpi_ut_execute_HID(node, &hid);
 582                 if (status == AE_NOT_FOUND) {
 583                         return (AE_OK);
 584                 } else if (ACPI_FAILURE(status)) {
 585                         return (AE_CTRL_DEPTH);
 586                 }
 587
 588                 no_match = ACPI_STRCMP(hid->string, info->hid);
 589                 ACPI_FREE(hid);
 590
 591                 if (no_match) {
 592                         /*
 593                          * HID does not match, attempt match within the
 594                          * list of Compatible IDs (CIDs)
 595                          */
 596                         status = acpi_ut_execute_CID(node, &cid);
 597                         if (status == AE_NOT_FOUND) {
 598                                 return (AE_OK);
 599                         } else if (ACPI_FAILURE(status)) {
 600                                 return (AE_CTRL_DEPTH);
 601                         }
 602
 603                         /* Walk the CID list */
 604
 605                         found = 0;
 606                         for (i = 0; i < cid->count; i++) {
 607                                 if (ACPI_STRCMP(cid->ids[i].string, info->hid)
 608                                     == 0) {
 609                                         found = 1;
 610                                         break;
 611                                 }
 612                         }
 613                         ACPI_FREE(cid);
 614                         if (!found)
 615                                 return (AE_OK);
 616                 }
 617         }
 618
 619         /* Run _STA to determine if device is present */
 620
 621         status = acpi_ut_execute_STA(node, &flags);
 622         if (ACPI_FAILURE(status)) {
 623                 return (AE_CTRL_DEPTH);
 624         }
 625
 626         if (!(flags & ACPI_STA_DEVICE_PRESENT) &&
 627             !(flags & ACPI_STA_DEVICE_FUNCTIONING)) {
 628                 /*
 629                  * Don't examine the children of the device only when the
 630                  * device is neither present nor functional. See ACPI spec,
 631                  * description of _STA for more information.
 632                  */
 633                 return (AE_CTRL_DEPTH);
 634         }
 635
 636         /* We have a valid device, invoke the user function */
 637
 638         status = info->user_function(obj_handle, nesting_level, info->context,
 639                                      return_value);
 640         return (status);
 641 }
 642
 643 /*******************************************************************************
 644  *
 645  * FUNCTION:    acpi_get_devices
 646  *
 647  * PARAMETERS:  HID                 - HID to search for. Can be NULL.
 648  *              user_function       - Called when a matching object is found
 649  *              Context             - Passed to user function
 650  *              return_value        - Location where return value of
 651  *                                    user_function is put if terminated early
 652  *
 653  * RETURNS      Return value from the user_function if terminated early.
 654  *              Otherwise, returns NULL.
 655  *
 656  * DESCRIPTION: Performs a modified depth-first walk of the namespace tree,
 657  *              starting (and ending) at the object specified by start_handle.
 658  *              The user_function is called whenever an object of type
 659  *              Device is found.  If the user function returns
 660  *              a non-zero value, the search is terminated immediately and this
 661  *              value is returned to the caller.
 662  *
 663  *              This is a wrapper for walk_namespace, but the callback performs
 664  *              additional filtering. Please see acpi_ns_get_device_callback.
 665  *
 666  ******************************************************************************/
 667
 668 acpi_status
 669 acpi_get_devices(const char *HID,
 670                  acpi_walk_callback user_function,
 671                  void *context, void **return_value)
 672 {
 673         acpi_status status;
 674         struct acpi_get_devices_info info;
 675
 676         ACPI_FUNCTION_TRACE(acpi_get_devices);
 677
 678         /* Parameter validation */
 679
 680         if (!user_function) {
 681                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 682         }
 683
 684         /*
 685          * We're going to call their callback from OUR callback, so we need
 686          * to know what it is, and their context parameter.
 687          */
 688         info.hid = HID;
 689         info.context = context;
 690         info.user_function = user_function;
 691
 692         /*
 693          * Lock the namespace around the walk.
 694          * The namespace will be unlocked/locked around each call
 695          * to the user function - since this function
 696          * must be allowed to make Acpi calls itself.
 697          */
 698         status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
 699         if (ACPI_FAILURE(status)) {
 700                 return_ACPI_STATUS(status);
 701         }
 702
 703         status = acpi_ns_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 704                                         ACPI_UINT32_MAX, ACPI_NS_WALK_UNLOCK,
 705                                         acpi_ns_get_device_callback, NULL,
 706                                         &info, return_value);
 707
 708         (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
 709         return_ACPI_STATUS(status);
 710 }
 711
 712 ACPI_EXPORT_SYMBOL(acpi_get_devices)
 713
 714 /*******************************************************************************
 715  *
 716  * FUNCTION:    acpi_attach_data
 717  *
 718  * PARAMETERS:  obj_handle          - Namespace node
 719  *              Handler             - Handler for this attachment
 720  *              Data                - Pointer to data to be attached
 721  *
 722  * RETURN:      Status
 723  *
 724  * DESCRIPTION: Attach arbitrary data and handler to a namespace node.
 725  *
 726  ******************************************************************************/
 727 acpi_status
 728 acpi_attach_data(acpi_handle obj_handle,
 729                  acpi_object_handler handler, void *data)
 730 {
 731         struct acpi_namespace_node *node;
 732         acpi_status status;
 733
 734         /* Parameter validation */
 735
 736         if (!obj_handle || !handler || !data) {
 737                 return (AE_BAD_PARAMETER);
 738         }
 739
 740         status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
 741         if (ACPI_FAILURE(status)) {
 742                 return (status);
 743         }
 744
 745         /* Convert and validate the handle */
 746
 747         node = acpi_ns_validate_handle(obj_handle);
 748         if (!node) {
 749                 status = AE_BAD_PARAMETER;
 750                 goto unlock_and_exit;
 751         }
 752
 753         status = acpi_ns_attach_data(node, handler, data);
 754
 755       unlock_and_exit:
 756         (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
 757         return (status);
 758 }
 759
 760 ACPI_EXPORT_SYMBOL(acpi_attach_data)
 761
 762 /*******************************************************************************
 763  *
 764  * FUNCTION:    acpi_detach_data
 765  *
 766  * PARAMETERS:  obj_handle          - Namespace node handle
 767  *              Handler             - Handler used in call to acpi_attach_data
 768  *
 769  * RETURN:      Status
 770  *
 771  * DESCRIPTION: Remove data that was previously attached to a node.
 772  *
 773  ******************************************************************************/
 774 acpi_status
 775 acpi_detach_data(acpi_handle obj_handle, acpi_object_handler handler)
 776 {
 777         struct acpi_namespace_node *node;
 778         acpi_status status;
 779
 780         /* Parameter validation */
 781
 782         if (!obj_handle || !handler) {
 783                 return (AE_BAD_PARAMETER);
 784         }
 785
 786         status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
 787         if (ACPI_FAILURE(status)) {
 788                 return (status);
 789         }
 790
 791         /* Convert and validate the handle */
 792
 793         node = acpi_ns_validate_handle(obj_handle);
 794         if (!node) {
 795                 status = AE_BAD_PARAMETER;
 796                 goto unlock_and_exit;
 797         }
 798
 799         status = acpi_ns_detach_data(node, handler);
 800
 801       unlock_and_exit:
 802         (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
 803         return (status);
 804 }
 805
 806 ACPI_EXPORT_SYMBOL(acpi_detach_data)
 807
 808 /*******************************************************************************
 809  *
 810  * FUNCTION:    acpi_get_data
 811  *
 812  * PARAMETERS:  obj_handle          - Namespace node
 813  *              Handler             - Handler used in call to attach_data
 814  *              Data                - Where the data is returned
 815  *
 816  * RETURN:      Status
 817  *
 818  * DESCRIPTION: Retrieve data that was previously attached to a namespace node.
 819  *
 820  ******************************************************************************/
 821 acpi_status
 822 acpi_get_data(acpi_handle obj_handle, acpi_object_handler handler, void **data)
 823 {
 824         struct acpi_namespace_node *node;
 825         acpi_status status;
 826
 827         /* Parameter validation */
 828
 829         if (!obj_handle || !handler || !data) {
 830                 return (AE_BAD_PARAMETER);
 831         }
 832
 833         status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
 834         if (ACPI_FAILURE(status)) {
 835                 return (status);
 836         }
 837
 838         /* Convert and validate the handle */
 839
 840         node = acpi_ns_validate_handle(obj_handle);
 841         if (!node) {
 842                 status = AE_BAD_PARAMETER;
 843                 goto unlock_and_exit;
 844         }
 845
 846         status = acpi_ns_get_attached_data(node, handler, data);
 847
 848       unlock_and_exit:
 849         (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
 850         return (status);
 851 }
 852
 853 ACPI_EXPORT_SYMBOL(acpi_get_data)