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 - 2013, 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 #include <linux/export.h>
  45 #include <acpi/acpi.h>
  46 #include "accommon.h"
  47 #include "acresrc.h"
  48 #include "acnamesp.h"
  49
  50 #define _COMPONENT          ACPI_RESOURCES
  51 ACPI_MODULE_NAME("rsxface")
  52
  53 /* Local macros for 16,32-bit to 64-bit conversion */
  54 #define ACPI_COPY_FIELD(out, in, field)  ((out)->field = (in)->field)
  55 #define ACPI_COPY_ADDRESS(out, in)                      \
  56         ACPI_COPY_FIELD(out, in, resource_type);             \
  57         ACPI_COPY_FIELD(out, in, producer_consumer);         \
  58         ACPI_COPY_FIELD(out, in, decode);                    \
  59         ACPI_COPY_FIELD(out, in, min_address_fixed);         \
  60         ACPI_COPY_FIELD(out, in, max_address_fixed);         \
  61         ACPI_COPY_FIELD(out, in, info);                      \
  62         ACPI_COPY_FIELD(out, in, granularity);               \
  63         ACPI_COPY_FIELD(out, in, minimum);                   \
  64         ACPI_COPY_FIELD(out, in, maximum);                   \
  65         ACPI_COPY_FIELD(out, in, translation_offset);        \
  66         ACPI_COPY_FIELD(out, in, address_length);            \
  67         ACPI_COPY_FIELD(out, in, resource_source);
  68 /* Local prototypes */
  69 static acpi_status
  70 acpi_rs_match_vendor_resource(struct acpi_resource *resource, void *context);
  71
  72 static acpi_status
  73 acpi_rs_validate_parameters(acpi_handle device_handle,
  74                             struct acpi_buffer *buffer,
  75                             struct acpi_namespace_node **return_node);
  76
  77 /*******************************************************************************
  78  *
  79  * FUNCTION:    acpi_rs_validate_parameters
  80  *
  81  * PARAMETERS:  device_handle   - Handle to a device
  82  *              buffer          - Pointer to a data buffer
  83  *              return_node     - Pointer to where the device node is returned
  84  *
  85  * RETURN:      Status
  86  *
  87  * DESCRIPTION: Common parameter validation for resource interfaces
  88  *
  89  ******************************************************************************/
  90
  91 static acpi_status
  92 acpi_rs_validate_parameters(acpi_handle device_handle,
  93                             struct acpi_buffer *buffer,
  94                             struct acpi_namespace_node **return_node)
  95 {
  96         acpi_status status;
  97         struct acpi_namespace_node *node;
  98
  99         ACPI_FUNCTION_TRACE(rs_validate_parameters);
 100
 101         /*
 102          * Must have a valid handle to an ACPI device
 103          */
 104         if (!device_handle) {
 105                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 106         }
 107
 108         node = acpi_ns_validate_handle(device_handle);
 109         if (!node) {
 110                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 111         }
 112
 113         if (node->type != ACPI_TYPE_DEVICE) {
 114                 return_ACPI_STATUS(AE_TYPE);
 115         }
 116
 117         /*
 118          * Validate the user buffer object
 119          *
 120          * if there is a non-zero buffer length we also need a valid pointer in
 121          * the buffer. If it's a zero buffer length, we'll be returning the
 122          * needed buffer size (later), so keep going.
 123          */
 124         status = acpi_ut_validate_buffer(buffer);
 125         if (ACPI_FAILURE(status)) {
 126                 return_ACPI_STATUS(status);
 127         }
 128
 129         *return_node = node;
 130         return_ACPI_STATUS(AE_OK);
 131 }
 132
 133 /*******************************************************************************
 134  *
 135  * FUNCTION:    acpi_get_irq_routing_table
 136  *
 137  * PARAMETERS:  device_handle   - Handle to the Bus device we are querying
 138  *              ret_buffer      - Pointer to a buffer to receive the
 139  *                                current resources for the device
 140  *
 141  * RETURN:      Status
 142  *
 143  * DESCRIPTION: This function is called to get the IRQ routing table for a
 144  *              specific bus. The caller must first acquire a handle for the
 145  *              desired bus. The routine table is placed in the buffer pointed
 146  *              to by the ret_buffer variable parameter.
 147  *
 148  *              If the function fails an appropriate status will be returned
 149  *              and the value of ret_buffer is undefined.
 150  *
 151  *              This function attempts to execute the _PRT method contained in
 152  *              the object indicated by the passed device_handle.
 153  *
 154  ******************************************************************************/
 155
 156 acpi_status
 157 acpi_get_irq_routing_table(acpi_handle device_handle,
 158                            struct acpi_buffer *ret_buffer)
 159 {
 160         acpi_status status;
 161         struct acpi_namespace_node *node;
 162
 163         ACPI_FUNCTION_TRACE(acpi_get_irq_routing_table);
 164
 165         /* Validate parameters then dispatch to internal routine */
 166
 167         status = acpi_rs_validate_parameters(device_handle, ret_buffer, &node);
 168         if (ACPI_FAILURE(status)) {
 169                 return_ACPI_STATUS(status);
 170         }
 171
 172         status = acpi_rs_get_prt_method_data(node, ret_buffer);
 173         return_ACPI_STATUS(status);
 174 }
 175
 176 ACPI_EXPORT_SYMBOL(acpi_get_irq_routing_table)
 177
 178 /*******************************************************************************
 179  *
 180  * FUNCTION:    acpi_get_current_resources
 181  *
 182  * PARAMETERS:  device_handle   - Handle to the device object for the
 183  *                                device we are querying
 184  *              ret_buffer      - Pointer to a buffer to receive the
 185  *                                current resources for the device
 186  *
 187  * RETURN:      Status
 188  *
 189  * DESCRIPTION: This function is called to get the current resources for a
 190  *              specific device. The caller must first acquire a handle for
 191  *              the desired device. The resource data is placed in the buffer
 192  *              pointed to by the ret_buffer variable parameter.
 193  *
 194  *              If the function fails an appropriate status will be returned
 195  *              and the value of ret_buffer is undefined.
 196  *
 197  *              This function attempts to execute the _CRS method contained in
 198  *              the object indicated by the passed device_handle.
 199  *
 200  ******************************************************************************/
 201 acpi_status
 202 acpi_get_current_resources(acpi_handle device_handle,
 203                            struct acpi_buffer *ret_buffer)
 204 {
 205         acpi_status status;
 206         struct acpi_namespace_node *node;
 207
 208         ACPI_FUNCTION_TRACE(acpi_get_current_resources);
 209
 210         /* Validate parameters then dispatch to internal routine */
 211
 212         status = acpi_rs_validate_parameters(device_handle, ret_buffer, &node);
 213         if (ACPI_FAILURE(status)) {
 214                 return_ACPI_STATUS(status);
 215         }
 216
 217         status = acpi_rs_get_crs_method_data(node, ret_buffer);
 218         return_ACPI_STATUS(status);
 219 }
 220
 221 ACPI_EXPORT_SYMBOL(acpi_get_current_resources)
 222 #ifdef ACPI_FUTURE_USAGE
 223 /*******************************************************************************
 224  *
 225  * FUNCTION:    acpi_get_possible_resources
 226  *
 227  * PARAMETERS:  device_handle   - Handle to the device object for the
 228  *                                device we are querying
 229  *              ret_buffer      - Pointer to a buffer to receive the
 230  *                                resources for the device
 231  *
 232  * RETURN:      Status
 233  *
 234  * DESCRIPTION: This function is called to get a list of the possible resources
 235  *              for a specific device. The caller must first acquire a handle
 236  *              for the desired device. The resource data is placed in the
 237  *              buffer pointed to by the ret_buffer variable.
 238  *
 239  *              If the function fails an appropriate status will be returned
 240  *              and the value of ret_buffer is undefined.
 241  *
 242  ******************************************************************************/
 243 acpi_status
 244 acpi_get_possible_resources(acpi_handle device_handle,
 245                             struct acpi_buffer *ret_buffer)
 246 {
 247         acpi_status status;
 248         struct acpi_namespace_node *node;
 249
 250         ACPI_FUNCTION_TRACE(acpi_get_possible_resources);
 251
 252         /* Validate parameters then dispatch to internal routine */
 253
 254         status = acpi_rs_validate_parameters(device_handle, ret_buffer, &node);
 255         if (ACPI_FAILURE(status)) {
 256                 return_ACPI_STATUS(status);
 257         }
 258
 259         status = acpi_rs_get_prs_method_data(node, ret_buffer);
 260         return_ACPI_STATUS(status);
 261 }
 262
 263 ACPI_EXPORT_SYMBOL(acpi_get_possible_resources)
 264 #endif                          /*  ACPI_FUTURE_USAGE  */
 265 /*******************************************************************************
 266  *
 267  * FUNCTION:    acpi_set_current_resources
 268  *
 269  * PARAMETERS:  device_handle   - Handle to the device object for the
 270  *                                device we are setting resources
 271  *              in_buffer       - Pointer to a buffer containing the
 272  *                                resources to be set for the device
 273  *
 274  * RETURN:      Status
 275  *
 276  * DESCRIPTION: This function is called to set the current resources for a
 277  *              specific device. The caller must first acquire a handle for
 278  *              the desired device. The resource data is passed to the routine
 279  *              the buffer pointed to by the in_buffer variable.
 280  *
 281  ******************************************************************************/
 282 acpi_status
 283 acpi_set_current_resources(acpi_handle device_handle,
 284                            struct acpi_buffer *in_buffer)
 285 {
 286         acpi_status status;
 287         struct acpi_namespace_node *node;
 288
 289         ACPI_FUNCTION_TRACE(acpi_set_current_resources);
 290
 291         /* Validate the buffer, don't allow zero length */
 292
 293         if ((!in_buffer) || (!in_buffer->pointer) || (!in_buffer->length)) {
 294                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 295         }
 296
 297         /* Validate parameters then dispatch to internal routine */
 298
 299         status = acpi_rs_validate_parameters(device_handle, in_buffer, &node);
 300         if (ACPI_FAILURE(status)) {
 301                 return_ACPI_STATUS(status);
 302         }
 303
 304         status = acpi_rs_set_srs_method_data(node, in_buffer);
 305         return_ACPI_STATUS(status);
 306 }
 307
 308 ACPI_EXPORT_SYMBOL(acpi_set_current_resources)
 309
 310 /*******************************************************************************
 311  *
 312  * FUNCTION:    acpi_get_event_resources
 313  *
 314  * PARAMETERS:  device_handle   - Handle to the device object for the
 315  *                                device we are getting resources
 316  *              in_buffer       - Pointer to a buffer containing the
 317  *                                resources to be set for the device
 318  *
 319  * RETURN:      Status
 320  *
 321  * DESCRIPTION: This function is called to get the event resources for a
 322  *              specific device. The caller must first acquire a handle for
 323  *              the desired device. The resource data is passed to the routine
 324  *              the buffer pointed to by the in_buffer variable. Uses the
 325  *              _AEI method.
 326  *
 327  ******************************************************************************/
 328 acpi_status
 329 acpi_get_event_resources(acpi_handle device_handle,
 330                          struct acpi_buffer *ret_buffer)
 331 {
 332         acpi_status status;
 333         struct acpi_namespace_node *node;
 334
 335         ACPI_FUNCTION_TRACE(acpi_get_event_resources);
 336
 337         /* Validate parameters then dispatch to internal routine */
 338
 339         status = acpi_rs_validate_parameters(device_handle, ret_buffer, &node);
 340         if (ACPI_FAILURE(status)) {
 341                 return_ACPI_STATUS(status);
 342         }
 343
 344         status = acpi_rs_get_aei_method_data(node, ret_buffer);
 345         return_ACPI_STATUS(status);
 346 }
 347
 348 ACPI_EXPORT_SYMBOL(acpi_get_event_resources)
 349
 350 /******************************************************************************
 351  *
 352  * FUNCTION:    acpi_resource_to_address64
 353  *
 354  * PARAMETERS:  resource        - Pointer to a resource
 355  *              out             - Pointer to the users's return buffer
 356  *                                (a struct acpi_resource_address64)
 357  *
 358  * RETURN:      Status
 359  *
 360  * DESCRIPTION: If the resource is an address16, address32, or address64,
 361  *              copy it to the address64 return buffer. This saves the
 362  *              caller from having to duplicate code for different-sized
 363  *              addresses.
 364  *
 365  ******************************************************************************/
 366 acpi_status
 367 acpi_resource_to_address64(struct acpi_resource *resource,
 368                            struct acpi_resource_address64 *out)
 369 {
 370         struct acpi_resource_address16 *address16;
 371         struct acpi_resource_address32 *address32;
 372
 373         if (!resource || !out) {
 374                 return (AE_BAD_PARAMETER);
 375         }
 376
 377         /* Convert 16 or 32 address descriptor to 64 */
 378
 379         switch (resource->type) {
 380         case ACPI_RESOURCE_TYPE_ADDRESS16:
 381
 382                 address16 =
 383                     ACPI_CAST_PTR(struct acpi_resource_address16,
 384                                   &resource->data);
 385                 ACPI_COPY_ADDRESS(out, address16);
 386                 break;
 387
 388         case ACPI_RESOURCE_TYPE_ADDRESS32:
 389
 390                 address32 =
 391                     ACPI_CAST_PTR(struct acpi_resource_address32,
 392                                   &resource->data);
 393                 ACPI_COPY_ADDRESS(out, address32);
 394                 break;
 395
 396         case ACPI_RESOURCE_TYPE_ADDRESS64:
 397
 398                 /* Simple copy for 64 bit source */
 399
 400                 ACPI_MEMCPY(out, &resource->data,
 401                             sizeof(struct acpi_resource_address64));
 402                 break;
 403
 404         default:
 405                 return (AE_BAD_PARAMETER);
 406         }
 407
 408         return (AE_OK);
 409 }
 410
 411 ACPI_EXPORT_SYMBOL(acpi_resource_to_address64)
 412
 413 /*******************************************************************************
 414  *
 415  * FUNCTION:    acpi_get_vendor_resource
 416  *
 417  * PARAMETERS:  device_handle   - Handle for the parent device object
 418  *              name            - Method name for the parent resource
 419  *                                (METHOD_NAME__CRS or METHOD_NAME__PRS)
 420  *              uuid            - Pointer to the UUID to be matched.
 421  *                                includes both subtype and 16-byte UUID
 422  *              ret_buffer      - Where the vendor resource is returned
 423  *
 424  * RETURN:      Status
 425  *
 426  * DESCRIPTION: Walk a resource template for the specified device to find a
 427  *              vendor-defined resource that matches the supplied UUID and
 428  *              UUID subtype. Returns a struct acpi_resource of type Vendor.
 429  *
 430  ******************************************************************************/
 431 acpi_status
 432 acpi_get_vendor_resource(acpi_handle device_handle,
 433                          char *name,
 434                          struct acpi_vendor_uuid * uuid,
 435                          struct acpi_buffer * ret_buffer)
 436 {
 437         struct acpi_vendor_walk_info info;
 438         acpi_status status;
 439
 440         /* Other parameters are validated by acpi_walk_resources */
 441
 442         if (!uuid || !ret_buffer) {
 443                 return (AE_BAD_PARAMETER);
 444         }
 445
 446         info.uuid = uuid;
 447         info.buffer = ret_buffer;
 448         info.status = AE_NOT_EXIST;
 449
 450         /* Walk the _CRS or _PRS resource list for this device */
 451
 452         status =
 453             acpi_walk_resources(device_handle, name,
 454                                 acpi_rs_match_vendor_resource, &info);
 455         if (ACPI_FAILURE(status)) {
 456                 return (status);
 457         }
 458
 459         return (info.status);
 460 }
 461
 462 ACPI_EXPORT_SYMBOL(acpi_get_vendor_resource)
 463
 464 /*******************************************************************************
 465  *
 466  * FUNCTION:    acpi_rs_match_vendor_resource
 467  *
 468  * PARAMETERS:  acpi_walk_resource_callback
 469  *
 470  * RETURN:      Status
 471  *
 472  * DESCRIPTION: Match a vendor resource via the ACPI 3.0 UUID
 473  *
 474  ******************************************************************************/
 475 static acpi_status
 476 acpi_rs_match_vendor_resource(struct acpi_resource *resource, void *context)
 477 {
 478         struct acpi_vendor_walk_info *info = context;
 479         struct acpi_resource_vendor_typed *vendor;
 480         struct acpi_buffer *buffer;
 481         acpi_status status;
 482
 483         /* Ignore all descriptors except Vendor */
 484
 485         if (resource->type != ACPI_RESOURCE_TYPE_VENDOR) {
 486                 return (AE_OK);
 487         }
 488
 489         vendor = &resource->data.vendor_typed;
 490
 491         /*
 492          * For a valid match, these conditions must hold:
 493          *
 494          * 1) Length of descriptor data must be at least as long as a UUID struct
 495          * 2) The UUID subtypes must match
 496          * 3) The UUID data must match
 497          */
 498         if ((vendor->byte_length < (ACPI_UUID_LENGTH + 1)) ||
 499             (vendor->uuid_subtype != info->uuid->subtype) ||
 500             (ACPI_MEMCMP(vendor->uuid, info->uuid->data, ACPI_UUID_LENGTH))) {
 501                 return (AE_OK);
 502         }
 503
 504         /* Validate/Allocate/Clear caller buffer */
 505
 506         buffer = info->buffer;
 507         status = acpi_ut_initialize_buffer(buffer, resource->length);
 508         if (ACPI_FAILURE(status)) {
 509                 return (status);
 510         }
 511
 512         /* Found the correct resource, copy and return it */
 513
 514         ACPI_MEMCPY(buffer->pointer, resource, resource->length);
 515         buffer->length = resource->length;
 516
 517         /* Found the desired descriptor, terminate resource walk */
 518
 519         info->status = AE_OK;
 520         return (AE_CTRL_TERMINATE);
 521 }
 522
 523 /*******************************************************************************
 524  *
 525  * FUNCTION:    acpi_walk_resource_buffer
 526  *
 527  * PARAMETERS:  buffer          - Formatted buffer returned by one of the
 528  *                                various Get*Resource functions
 529  *              user_function   - Called for each resource
 530  *              context         - Passed to user_function
 531  *
 532  * RETURN:      Status
 533  *
 534  * DESCRIPTION: Walks the input resource template. The user_function is called
 535  *              once for each resource in the list.
 536  *
 537  ******************************************************************************/
 538
 539 acpi_status
 540 acpi_walk_resource_buffer(struct acpi_buffer * buffer,
 541                           acpi_walk_resource_callback user_function,
 542                           void *context)
 543 {
 544         acpi_status status = AE_OK;
 545         struct acpi_resource *resource;
 546         struct acpi_resource *resource_end;
 547
 548         ACPI_FUNCTION_TRACE(acpi_walk_resource_buffer);
 549
 550         /* Parameter validation */
 551
 552         if (!buffer || !buffer->pointer || !user_function) {
 553                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 554         }
 555
 556         /* Buffer contains the resource list and length */
 557
 558         resource = ACPI_CAST_PTR(struct acpi_resource, buffer->pointer);
 559         resource_end =
 560             ACPI_ADD_PTR(struct acpi_resource, buffer->pointer, buffer->length);
 561
 562         /* Walk the resource list until the end_tag is found (or buffer end) */
 563
 564         while (resource < resource_end) {
 565
 566                 /* Sanity check the resource */
 567
 568                 if (resource->type > ACPI_RESOURCE_TYPE_MAX) {
 569                         status = AE_AML_INVALID_RESOURCE_TYPE;
 570                         break;
 571                 }
 572
 573                 /* Invoke the user function, abort on any error returned */
 574
 575                 status = user_function(resource, context);
 576                 if (ACPI_FAILURE(status)) {
 577                         if (status == AE_CTRL_TERMINATE) {
 578
 579                                 /* This is an OK termination by the user function */
 580
 581                                 status = AE_OK;
 582                         }
 583                         break;
 584                 }
 585
 586                 /* end_tag indicates end-of-list */
 587
 588                 if (resource->type == ACPI_RESOURCE_TYPE_END_TAG) {
 589                         break;
 590                 }
 591
 592                 /* Get the next resource descriptor */
 593
 594                 resource = ACPI_NEXT_RESOURCE(resource);
 595         }
 596
 597         return_ACPI_STATUS(status);
 598 }
 599
 600 ACPI_EXPORT_SYMBOL(acpi_walk_resource_buffer)
 601
 602 /*******************************************************************************
 603  *
 604  * FUNCTION:    acpi_walk_resources
 605  *
 606  * PARAMETERS:  device_handle   - Handle to the device object for the
 607  *                                device we are querying
 608  *              name            - Method name of the resources we want.
 609  *                                (METHOD_NAME__CRS, METHOD_NAME__PRS, or
 610  *                                METHOD_NAME__AEI)
 611  *              user_function   - Called for each resource
 612  *              context         - Passed to user_function
 613  *
 614  * RETURN:      Status
 615  *
 616  * DESCRIPTION: Retrieves the current or possible resource list for the
 617  *              specified device. The user_function is called once for
 618  *              each resource in the list.
 619  *
 620  ******************************************************************************/
 621 acpi_status
 622 acpi_walk_resources(acpi_handle device_handle,
 623                     char *name,
 624                     acpi_walk_resource_callback user_function, void *context)
 625 {
 626         acpi_status status;
 627         struct acpi_buffer buffer;
 628
 629         ACPI_FUNCTION_TRACE(acpi_walk_resources);
 630
 631         /* Parameter validation */
 632
 633         if (!device_handle || !user_function || !name ||
 634             (!ACPI_COMPARE_NAME(name, METHOD_NAME__CRS) &&
 635              !ACPI_COMPARE_NAME(name, METHOD_NAME__PRS) &&
 636              !ACPI_COMPARE_NAME(name, METHOD_NAME__AEI))) {
 637                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 638         }
 639
 640         /* Get the _CRS/_PRS/_AEI resource list */
 641
 642         buffer.length = ACPI_ALLOCATE_LOCAL_BUFFER;
 643         status = acpi_rs_get_method_data(device_handle, name, &buffer);
 644         if (ACPI_FAILURE(status)) {
 645                 return_ACPI_STATUS(status);
 646         }
 647
 648         /* Walk the resource list and cleanup */
 649
 650         status = acpi_walk_resource_buffer(&buffer, user_function, context);
 651         ACPI_FREE(buffer.pointer);
 652         return_ACPI_STATUS(status);
 653 }
 654
 655 ACPI_EXPORT_SYMBOL(acpi_walk_resources)