drivers/acpi/acpica/rsxface.c

   1 /*******************************************************************************
   2  *
   3  * Module Name: rsxface - Public interfaces to the resource manager
   4  *
   5  ******************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2017, Intel Corp.
   9  * All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions, and the following disclaimer,
  16  *    without modification.
  17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
  18  *    substantially similar to the "NO WARRANTY" disclaimer below
  19  *    ("Disclaimer") and any redistribution must be conditioned upon
  20  *    including a substantially similar Disclaimer requirement for further
  21  *    binary redistribution.
  22  * 3. Neither the names of the above-listed copyright holders nor the names
  23  *    of any contributors may be used to endorse or promote products derived
  24  *    from this software without specific prior written permission.
  25  *
  26  * Alternatively, this software may be distributed under the terms of the
  27  * GNU General Public License ("GPL") version 2 as published by the Free
  28  * Software Foundation.
  29  *
  30  * NO WARRANTY
  31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
  34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  41  * POSSIBILITY OF SUCH DAMAGES.
  42  */
  43
  44 #define EXPORT_ACPI_INTERFACES
  45
  46 #include <acpi/acpi.h>
  47 #include "accommon.h"
  48 #include "acresrc.h"
  49 #include "acnamesp.h"
  50
  51 #define _COMPONENT          ACPI_RESOURCES
  52 ACPI_MODULE_NAME("rsxface")
  53
  54 /* Local macros for 16,32-bit to 64-bit conversion */
  55 #define ACPI_COPY_FIELD(out, in, field)  ((out)->field = (in)->field)
  56 #define ACPI_COPY_ADDRESS(out, in)                       \
  57         ACPI_COPY_FIELD(out, in, resource_type);             \
  58         ACPI_COPY_FIELD(out, in, producer_consumer);         \
  59         ACPI_COPY_FIELD(out, in, decode);                    \
  60         ACPI_COPY_FIELD(out, in, min_address_fixed);         \
  61         ACPI_COPY_FIELD(out, in, max_address_fixed);         \
  62         ACPI_COPY_FIELD(out, in, info);                      \
  63         ACPI_COPY_FIELD(out, in, address.granularity);       \
  64         ACPI_COPY_FIELD(out, in, address.minimum);           \
  65         ACPI_COPY_FIELD(out, in, address.maximum);           \
  66         ACPI_COPY_FIELD(out, in, address.translation_offset); \
  67         ACPI_COPY_FIELD(out, in, address.address_length);    \
  68         ACPI_COPY_FIELD(out, in, resource_source);
  69 /* Local prototypes */
  70 static acpi_status
  71 acpi_rs_match_vendor_resource(struct acpi_resource *resource, void *context);
  72
  73 static acpi_status
  74 acpi_rs_validate_parameters(acpi_handle device_handle,
  75                             struct acpi_buffer *buffer,
  76                             struct acpi_namespace_node **return_node);
  77
  78 /*******************************************************************************
  79  *
  80  * FUNCTION:    acpi_rs_validate_parameters
  81  *
  82  * PARAMETERS:  device_handle   - Handle to a device
  83  *              buffer          - Pointer to a data buffer
  84  *              return_node     - Pointer to where the device node is returned
  85  *
  86  * RETURN:      Status
  87  *
  88  * DESCRIPTION: Common parameter validation for resource interfaces
  89  *
  90  ******************************************************************************/
  91
  92 static acpi_status
  93 acpi_rs_validate_parameters(acpi_handle device_handle,
  94                             struct acpi_buffer *buffer,
  95                             struct acpi_namespace_node **return_node)
  96 {
  97         acpi_status status;
  98         struct acpi_namespace_node *node;
  99
 100         ACPI_FUNCTION_TRACE(rs_validate_parameters);
 101
 102         /*
 103          * Must have a valid handle to an ACPI device
 104          */
 105         if (!device_handle) {
 106                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 107         }
 108
 109         node = acpi_ns_validate_handle(device_handle);
 110         if (!node) {
 111                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 112         }
 113
 114         if (node->type != ACPI_TYPE_DEVICE) {
 115                 return_ACPI_STATUS(AE_TYPE);
 116         }
 117
 118         /*
 119          * Validate the user buffer object
 120          *
 121          * if there is a non-zero buffer length we also need a valid pointer in
 122          * the buffer. If it's a zero buffer length, we'll be returning the
 123          * needed buffer size (later), so keep going.
 124          */
 125         status = acpi_ut_validate_buffer(buffer);
 126         if (ACPI_FAILURE(status)) {
 127                 return_ACPI_STATUS(status);
 128         }
 129
 130         *return_node = node;
 131         return_ACPI_STATUS(AE_OK);
 132 }
 133
 134 /*******************************************************************************
 135  *
 136  * FUNCTION:    acpi_get_irq_routing_table
 137  *
 138  * PARAMETERS:  device_handle   - Handle to the Bus device we are querying
 139  *              ret_buffer      - Pointer to a buffer to receive the
 140  *                                current resources for the device
 141  *
 142  * RETURN:      Status
 143  *
 144  * DESCRIPTION: This function is called to get the IRQ routing table for a
 145  *              specific bus. The caller must first acquire a handle for the
 146  *              desired bus. The routine table is placed in the buffer pointed
 147  *              to by the ret_buffer variable parameter.
 148  *
 149  *              If the function fails an appropriate status will be returned
 150  *              and the value of ret_buffer is undefined.
 151  *
 152  *              This function attempts to execute the _PRT method contained in
 153  *              the object indicated by the passed device_handle.
 154  *
 155  ******************************************************************************/
 156
 157 acpi_status
 158 acpi_get_irq_routing_table(acpi_handle device_handle,
 159                            struct acpi_buffer *ret_buffer)
 160 {
 161         acpi_status status;
 162         struct acpi_namespace_node *node;
 163
 164         ACPI_FUNCTION_TRACE(acpi_get_irq_routing_table);
 165
 166         /* Validate parameters then dispatch to internal routine */
 167
 168         status = acpi_rs_validate_parameters(device_handle, ret_buffer, &node);
 169         if (ACPI_FAILURE(status)) {
 170                 return_ACPI_STATUS(status);
 171         }
 172
 173         status = acpi_rs_get_prt_method_data(node, ret_buffer);
 174         return_ACPI_STATUS(status);
 175 }
 176
 177 ACPI_EXPORT_SYMBOL(acpi_get_irq_routing_table)
 178
 179 /*******************************************************************************
 180  *
 181  * FUNCTION:    acpi_get_current_resources
 182  *
 183  * PARAMETERS:  device_handle   - Handle to the device object for the
 184  *                                device we are querying
 185  *              ret_buffer      - Pointer to a buffer to receive the
 186  *                                current resources for the device
 187  *
 188  * RETURN:      Status
 189  *
 190  * DESCRIPTION: This function is called to get the current resources for a
 191  *              specific device. The caller must first acquire a handle for
 192  *              the desired device. The resource data is placed in the buffer
 193  *              pointed to by the ret_buffer variable parameter.
 194  *
 195  *              If the function fails an appropriate status will be returned
 196  *              and the value of ret_buffer is undefined.
 197  *
 198  *              This function attempts to execute the _CRS method contained in
 199  *              the object indicated by the passed device_handle.
 200  *
 201  ******************************************************************************/
 202 acpi_status
 203 acpi_get_current_resources(acpi_handle device_handle,
 204                            struct acpi_buffer *ret_buffer)
 205 {
 206         acpi_status status;
 207         struct acpi_namespace_node *node;
 208
 209         ACPI_FUNCTION_TRACE(acpi_get_current_resources);
 210
 211         /* Validate parameters then dispatch to internal routine */
 212
 213         status = acpi_rs_validate_parameters(device_handle, ret_buffer, &node);
 214         if (ACPI_FAILURE(status)) {
 215                 return_ACPI_STATUS(status);
 216         }
 217
 218         status = acpi_rs_get_crs_method_data(node, ret_buffer);
 219         return_ACPI_STATUS(status);
 220 }
 221
 222 ACPI_EXPORT_SYMBOL(acpi_get_current_resources)
 223
 224 /*******************************************************************************
 225  *
 226  * FUNCTION:    acpi_get_possible_resources
 227  *
 228  * PARAMETERS:  device_handle   - Handle to the device object for the
 229  *                                device we are querying
 230  *              ret_buffer      - Pointer to a buffer to receive the
 231  *                                resources for the device
 232  *
 233  * RETURN:      Status
 234  *
 235  * DESCRIPTION: This function is called to get a list of the possible resources
 236  *              for a specific device. The caller must first acquire a handle
 237  *              for the desired device. The resource data is placed in the
 238  *              buffer pointed to by the ret_buffer variable.
 239  *
 240  *              If the function fails an appropriate status will be returned
 241  *              and the value of ret_buffer is undefined.
 242  *
 243  ******************************************************************************/
 244 acpi_status
 245 acpi_get_possible_resources(acpi_handle device_handle,
 246                             struct acpi_buffer *ret_buffer)
 247 {
 248         acpi_status status;
 249         struct acpi_namespace_node *node;
 250
 251         ACPI_FUNCTION_TRACE(acpi_get_possible_resources);
 252
 253         /* Validate parameters then dispatch to internal routine */
 254
 255         status = acpi_rs_validate_parameters(device_handle, ret_buffer, &node);
 256         if (ACPI_FAILURE(status)) {
 257                 return_ACPI_STATUS(status);
 258         }
 259
 260         status = acpi_rs_get_prs_method_data(node, ret_buffer);
 261         return_ACPI_STATUS(status);
 262 }
 263
 264 ACPI_EXPORT_SYMBOL(acpi_get_possible_resources)
 265
 266 /*******************************************************************************
 267  *
 268  * FUNCTION:    acpi_set_current_resources
 269  *
 270  * PARAMETERS:  device_handle   - Handle to the device object for the
 271  *                                device we are setting resources
 272  *              in_buffer       - Pointer to a buffer containing the
 273  *                                resources to be set for the device
 274  *
 275  * RETURN:      Status
 276  *
 277  * DESCRIPTION: This function is called to set the current resources for a
 278  *              specific device. The caller must first acquire a handle for
 279  *              the desired device. The resource data is passed to the routine
 280  *              the buffer pointed to by the in_buffer variable.
 281  *
 282  ******************************************************************************/
 283 acpi_status
 284 acpi_set_current_resources(acpi_handle device_handle,
 285                            struct acpi_buffer *in_buffer)
 286 {
 287         acpi_status status;
 288         struct acpi_namespace_node *node;
 289
 290         ACPI_FUNCTION_TRACE(acpi_set_current_resources);
 291
 292         /* Validate the buffer, don't allow zero length */
 293
 294         if ((!in_buffer) || (!in_buffer->pointer) || (!in_buffer->length)) {
 295                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 296         }
 297
 298         /* Validate parameters then dispatch to internal routine */
 299
 300         status = acpi_rs_validate_parameters(device_handle, in_buffer, &node);
 301         if (ACPI_FAILURE(status)) {
 302                 return_ACPI_STATUS(status);
 303         }
 304
 305         status = acpi_rs_set_srs_method_data(node, in_buffer);
 306         return_ACPI_STATUS(status);
 307 }
 308
 309 ACPI_EXPORT_SYMBOL(acpi_set_current_resources)
 310
 311 /*******************************************************************************
 312  *
 313  * FUNCTION:    acpi_get_event_resources
 314  *
 315  * PARAMETERS:  device_handle   - Handle to the device object for the
 316  *                                device we are getting resources
 317  *              in_buffer       - Pointer to a buffer containing the
 318  *                                resources to be set for the device
 319  *
 320  * RETURN:      Status
 321  *
 322  * DESCRIPTION: This function is called to get the event resources for a
 323  *              specific device. The caller must first acquire a handle for
 324  *              the desired device. The resource data is passed to the routine
 325  *              the buffer pointed to by the in_buffer variable. Uses the
 326  *              _AEI method.
 327  *
 328  ******************************************************************************/
 329 acpi_status
 330 acpi_get_event_resources(acpi_handle device_handle,
 331                          struct acpi_buffer *ret_buffer)
 332 {
 333         acpi_status status;
 334         struct acpi_namespace_node *node;
 335
 336         ACPI_FUNCTION_TRACE(acpi_get_event_resources);
 337
 338         /* Validate parameters then dispatch to internal routine */
 339
 340         status = acpi_rs_validate_parameters(device_handle, ret_buffer, &node);
 341         if (ACPI_FAILURE(status)) {
 342                 return_ACPI_STATUS(status);
 343         }
 344
 345         status = acpi_rs_get_aei_method_data(node, ret_buffer);
 346         return_ACPI_STATUS(status);
 347 }
 348
 349 ACPI_EXPORT_SYMBOL(acpi_get_event_resources)
 350
 351 /******************************************************************************
 352  *
 353  * FUNCTION:    acpi_resource_to_address64
 354  *
 355  * PARAMETERS:  resource        - Pointer to a resource
 356  *              out             - Pointer to the users's return buffer
 357  *                                (a struct acpi_resource_address64)
 358  *
 359  * RETURN:      Status
 360  *
 361  * DESCRIPTION: If the resource is an address16, address32, or address64,
 362  *              copy it to the address64 return buffer. This saves the
 363  *              caller from having to duplicate code for different-sized
 364  *              addresses.
 365  *
 366  ******************************************************************************/
 367 acpi_status
 368 acpi_resource_to_address64(struct acpi_resource *resource,
 369                            struct acpi_resource_address64 *out)
 370 {
 371         struct acpi_resource_address16 *address16;
 372         struct acpi_resource_address32 *address32;
 373
 374         if (!resource || !out) {
 375                 return (AE_BAD_PARAMETER);
 376         }
 377
 378         /* Convert 16 or 32 address descriptor to 64 */
 379
 380         switch (resource->type) {
 381         case ACPI_RESOURCE_TYPE_ADDRESS16:
 382
 383                 address16 =
 384                     ACPI_CAST_PTR(struct acpi_resource_address16,
 385                                   &resource->data);
 386                 ACPI_COPY_ADDRESS(out, address16);
 387                 break;
 388
 389         case ACPI_RESOURCE_TYPE_ADDRESS32:
 390
 391                 address32 =
 392                     ACPI_CAST_PTR(struct acpi_resource_address32,
 393                                   &resource->data);
 394                 ACPI_COPY_ADDRESS(out, address32);
 395                 break;
 396
 397         case ACPI_RESOURCE_TYPE_ADDRESS64:
 398
 399                 /* Simple copy for 64 bit source */
 400
 401                 memcpy(out, &resource->data,
 402                        sizeof(struct acpi_resource_address64));
 403                 break;
 404
 405         default:
 406
 407                 return (AE_BAD_PARAMETER);
 408         }
 409
 410         return (AE_OK);
 411 }
 412
 413 ACPI_EXPORT_SYMBOL(acpi_resource_to_address64)
 414
 415 /*******************************************************************************
 416  *
 417  * FUNCTION:    acpi_get_vendor_resource
 418  *
 419  * PARAMETERS:  device_handle   - Handle for the parent device object
 420  *              name            - Method name for the parent resource
 421  *                                (METHOD_NAME__CRS or METHOD_NAME__PRS)
 422  *              uuid            - Pointer to the UUID to be matched.
 423  *                                includes both subtype and 16-byte UUID
 424  *              ret_buffer      - Where the vendor resource is returned
 425  *
 426  * RETURN:      Status
 427  *
 428  * DESCRIPTION: Walk a resource template for the specified device to find a
 429  *              vendor-defined resource that matches the supplied UUID and
 430  *              UUID subtype. Returns a struct acpi_resource of type Vendor.
 431  *
 432  ******************************************************************************/
 433 acpi_status
 434 acpi_get_vendor_resource(acpi_handle device_handle,
 435                          char *name,
 436                          struct acpi_vendor_uuid *uuid,
 437                          struct acpi_buffer *ret_buffer)
 438 {
 439         struct acpi_vendor_walk_info info;
 440         acpi_status status;
 441
 442         /* Other parameters are validated by acpi_walk_resources */
 443
 444         if (!uuid || !ret_buffer) {
 445                 return (AE_BAD_PARAMETER);
 446         }
 447
 448         info.uuid = uuid;
 449         info.buffer = ret_buffer;
 450         info.status = AE_NOT_EXIST;
 451
 452         /* Walk the _CRS or _PRS resource list for this device */
 453
 454         status =
 455             acpi_walk_resources(device_handle, name,
 456                                 acpi_rs_match_vendor_resource, &info);
 457         if (ACPI_FAILURE(status)) {
 458                 return (status);
 459         }
 460
 461         return (info.status);
 462 }
 463
 464 ACPI_EXPORT_SYMBOL(acpi_get_vendor_resource)
 465
 466 /*******************************************************************************
 467  *
 468  * FUNCTION:    acpi_rs_match_vendor_resource
 469  *
 470  * PARAMETERS:  acpi_walk_resource_callback
 471  *
 472  * RETURN:      Status
 473  *
 474  * DESCRIPTION: Match a vendor resource via the ACPI 3.0 UUID
 475  *
 476  ******************************************************************************/
 477 static acpi_status
 478 acpi_rs_match_vendor_resource(struct acpi_resource *resource, void *context)
 479 {
 480         struct acpi_vendor_walk_info *info = context;
 481         struct acpi_resource_vendor_typed *vendor;
 482         struct acpi_buffer *buffer;
 483         acpi_status status;
 484
 485         /* Ignore all descriptors except Vendor */
 486
 487         if (resource->type != ACPI_RESOURCE_TYPE_VENDOR) {
 488                 return (AE_OK);
 489         }
 490
 491         vendor = &resource->data.vendor_typed;
 492
 493         /*
 494          * For a valid match, these conditions must hold:
 495          *
 496          * 1) Length of descriptor data must be at least as long as a UUID struct
 497          * 2) The UUID subtypes must match
 498          * 3) The UUID data must match
 499          */
 500         if ((vendor->byte_length < (ACPI_UUID_LENGTH + 1)) ||
 501             (vendor->uuid_subtype != info->uuid->subtype) ||
 502             (memcmp(vendor->uuid, info->uuid->data, ACPI_UUID_LENGTH))) {
 503                 return (AE_OK);
 504         }
 505
 506         /* Validate/Allocate/Clear caller buffer */
 507
 508         buffer = info->buffer;
 509         status = acpi_ut_initialize_buffer(buffer, resource->length);
 510         if (ACPI_FAILURE(status)) {
 511                 return (status);
 512         }
 513
 514         /* Found the correct resource, copy and return it */
 515
 516         memcpy(buffer->pointer, resource, resource->length);
 517         buffer->length = resource->length;
 518
 519         /* Found the desired descriptor, terminate resource walk */
 520
 521         info->status = AE_OK;
 522         return (AE_CTRL_TERMINATE);
 523 }
 524
 525 /*******************************************************************************
 526  *
 527  * FUNCTION:    acpi_walk_resource_buffer
 528  *
 529  * PARAMETERS:  buffer          - Formatted buffer returned by one of the
 530  *                                various Get*Resource functions
 531  *              user_function   - Called for each resource
 532  *              context         - Passed to user_function
 533  *
 534  * RETURN:      Status
 535  *
 536  * DESCRIPTION: Walks the input resource template. The user_function is called
 537  *              once for each resource in the list.
 538  *
 539  ******************************************************************************/
 540
 541 acpi_status
 542 acpi_walk_resource_buffer(struct acpi_buffer *buffer,
 543                           acpi_walk_resource_callback user_function,
 544                           void *context)
 545 {
 546         acpi_status status = AE_OK;
 547         struct acpi_resource *resource;
 548         struct acpi_resource *resource_end;
 549
 550         ACPI_FUNCTION_TRACE(acpi_walk_resource_buffer);
 551
 552         /* Parameter validation */
 553
 554         if (!buffer || !buffer->pointer || !user_function) {
 555                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 556         }
 557
 558         /* Buffer contains the resource list and length */
 559
 560         resource = ACPI_CAST_PTR(struct acpi_resource, buffer->pointer);
 561         resource_end =
 562             ACPI_ADD_PTR(struct acpi_resource, buffer->pointer, buffer->length);
 563
 564         /* Walk the resource list until the end_tag is found (or buffer end) */
 565
 566         while (resource < resource_end) {
 567
 568                 /* Sanity check the resource type */
 569
 570                 if (resource->type > ACPI_RESOURCE_TYPE_MAX) {
 571                         status = AE_AML_INVALID_RESOURCE_TYPE;
 572                         break;
 573                 }
 574
 575                 /* Sanity check the length. It must not be zero, or we loop forever */
 576
 577                 if (!resource->length) {
 578                         return_ACPI_STATUS(AE_AML_BAD_RESOURCE_LENGTH);
 579                 }
 580
 581                 /* Invoke the user function, abort on any error returned */
 582
 583                 status = user_function(resource, context);
 584                 if (ACPI_FAILURE(status)) {
 585                         if (status == AE_CTRL_TERMINATE) {
 586
 587                                 /* This is an OK termination by the user function */
 588
 589                                 status = AE_OK;
 590                         }
 591                         break;
 592                 }
 593
 594                 /* end_tag indicates end-of-list */
 595
 596                 if (resource->type == ACPI_RESOURCE_TYPE_END_TAG) {
 597                         break;
 598                 }
 599
 600                 /* Get the next resource descriptor */
 601
 602                 resource = ACPI_NEXT_RESOURCE(resource);
 603         }
 604
 605         return_ACPI_STATUS(status);
 606 }
 607
 608 ACPI_EXPORT_SYMBOL(acpi_walk_resource_buffer)
 609
 610 /*******************************************************************************
 611  *
 612  * FUNCTION:    acpi_walk_resources
 613  *
 614  * PARAMETERS:  device_handle   - Handle to the device object for the
 615  *                                device we are querying
 616  *              name            - Method name of the resources we want.
 617  *                                (METHOD_NAME__CRS, METHOD_NAME__PRS, or
 618  *                                METHOD_NAME__AEI or METHOD_NAME__DMA)
 619  *              user_function   - Called for each resource
 620  *              context         - Passed to user_function
 621  *
 622  * RETURN:      Status
 623  *
 624  * DESCRIPTION: Retrieves the current or possible resource list for the
 625  *              specified device. The user_function is called once for
 626  *              each resource in the list.
 627  *
 628  ******************************************************************************/
 629 acpi_status
 630 acpi_walk_resources(acpi_handle device_handle,
 631                     char *name,
 632                     acpi_walk_resource_callback user_function, void *context)
 633 {
 634         acpi_status status;
 635         struct acpi_buffer buffer;
 636
 637         ACPI_FUNCTION_TRACE(acpi_walk_resources);
 638
 639         /* Parameter validation */
 640
 641         if (!device_handle || !user_function || !name ||
 642             (!ACPI_COMPARE_NAME(name, METHOD_NAME__CRS) &&
 643              !ACPI_COMPARE_NAME(name, METHOD_NAME__PRS) &&
 644              !ACPI_COMPARE_NAME(name, METHOD_NAME__AEI) &&
 645              !ACPI_COMPARE_NAME(name, METHOD_NAME__DMA))) {
 646                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 647         }
 648
 649         /* Get the _CRS/_PRS/_AEI/_DMA resource list */
 650
 651         buffer.length = ACPI_ALLOCATE_LOCAL_BUFFER;
 652         status = acpi_rs_get_method_data(device_handle, name, &buffer);
 653         if (ACPI_FAILURE(status)) {
 654                 return_ACPI_STATUS(status);
 655         }
 656
 657         /* Walk the resource list and cleanup */
 658
 659         status = acpi_walk_resource_buffer(&buffer, user_function, context);
 660         ACPI_FREE(buffer.pointer);
 661         return_ACPI_STATUS(status);
 662 }
 663
 664 ACPI_EXPORT_SYMBOL(acpi_walk_resources)