drivers/acpi/resources/rsutils.c

   1 /*******************************************************************************
   2  *
   3  * Module Name: rsutils - Utilities for the resource manager
   4  *
   5  ******************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2008, 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 <acpi/acpi.h>
  45 #include <acpi/acnamesp.h>
  46 #include <acpi/acresrc.h>
  47
  48 #define _COMPONENT          ACPI_RESOURCES
  49 ACPI_MODULE_NAME("rsutils")
  50
  51 /*******************************************************************************
  52  *
  53  * FUNCTION:    acpi_rs_decode_bitmask
  54  *
  55  * PARAMETERS:  Mask            - Bitmask to decode
  56  *              List            - Where the converted list is returned
  57  *
  58  * RETURN:      Count of bits set (length of list)
  59  *
  60  * DESCRIPTION: Convert a bit mask into a list of values
  61  *
  62  ******************************************************************************/
  63 u8 acpi_rs_decode_bitmask(u16 mask, u8 * list)
  64 {
  65         acpi_native_uint i;
  66         u8 bit_count;
  67
  68         ACPI_FUNCTION_ENTRY();
  69
  70         /* Decode the mask bits */
  71
  72         for (i = 0, bit_count = 0; mask; i++) {
  73                 if (mask & 0x0001) {
  74                         list[bit_count] = (u8) i;
  75                         bit_count++;
  76                 }
  77
  78                 mask >>= 1;
  79         }
  80
  81         return (bit_count);
  82 }
  83
  84 /*******************************************************************************
  85  *
  86  * FUNCTION:    acpi_rs_encode_bitmask
  87  *
  88  * PARAMETERS:  List            - List of values to encode
  89  *              Count           - Length of list
  90  *
  91  * RETURN:      Encoded bitmask
  92  *
  93  * DESCRIPTION: Convert a list of values to an encoded bitmask
  94  *
  95  ******************************************************************************/
  96
  97 u16 acpi_rs_encode_bitmask(u8 * list, u8 count)
  98 {
  99         acpi_native_uint i;
 100         acpi_native_uint mask;
 101
 102         ACPI_FUNCTION_ENTRY();
 103
 104         /* Encode the list into a single bitmask */
 105
 106         for (i = 0, mask = 0; i < count; i++) {
 107                 mask |= (0x1 << list[i]);
 108         }
 109
 110         return ((u16) mask);
 111 }
 112
 113 /*******************************************************************************
 114  *
 115  * FUNCTION:    acpi_rs_move_data
 116  *
 117  * PARAMETERS:  Destination         - Pointer to the destination descriptor
 118  *              Source              - Pointer to the source descriptor
 119  *              item_count          - How many items to move
 120  *              move_type           - Byte width
 121  *
 122  * RETURN:      None
 123  *
 124  * DESCRIPTION: Move multiple data items from one descriptor to another. Handles
 125  *              alignment issues and endian issues if necessary, as configured
 126  *              via the ACPI_MOVE_* macros. (This is why a memcpy is not used)
 127  *
 128  ******************************************************************************/
 129
 130 void
 131 acpi_rs_move_data(void *destination, void *source, u16 item_count, u8 move_type)
 132 {
 133         acpi_native_uint i;
 134
 135         ACPI_FUNCTION_ENTRY();
 136
 137         /* One move per item */
 138
 139         for (i = 0; i < item_count; i++) {
 140                 switch (move_type) {
 141                         /*
 142                          * For the 8-bit case, we can perform the move all at once
 143                          * since there are no alignment or endian issues
 144                          */
 145                 case ACPI_RSC_MOVE8:
 146                         ACPI_MEMCPY(destination, source, item_count);
 147                         return;
 148
 149                         /*
 150                          * 16-, 32-, and 64-bit cases must use the move macros that perform
 151                          * endian conversion and/or accomodate hardware that cannot perform
 152                          * misaligned memory transfers
 153                          */
 154                 case ACPI_RSC_MOVE16:
 155                         ACPI_MOVE_16_TO_16(&ACPI_CAST_PTR(u16, destination)[i],
 156                                            &ACPI_CAST_PTR(u16, source)[i]);
 157                         break;
 158
 159                 case ACPI_RSC_MOVE32:
 160                         ACPI_MOVE_32_TO_32(&ACPI_CAST_PTR(u32, destination)[i],
 161                                            &ACPI_CAST_PTR(u32, source)[i]);
 162                         break;
 163
 164                 case ACPI_RSC_MOVE64:
 165                         ACPI_MOVE_64_TO_64(&ACPI_CAST_PTR(u64, destination)[i],
 166                                            &ACPI_CAST_PTR(u64, source)[i]);
 167                         break;
 168
 169                 default:
 170                         return;
 171                 }
 172         }
 173 }
 174
 175 /*******************************************************************************
 176  *
 177  * FUNCTION:    acpi_rs_set_resource_length
 178  *
 179  * PARAMETERS:  total_length        - Length of the AML descriptor, including
 180  *                                    the header and length fields.
 181  *              Aml                 - Pointer to the raw AML descriptor
 182  *
 183  * RETURN:      None
 184  *
 185  * DESCRIPTION: Set the resource_length field of an AML
 186  *              resource descriptor, both Large and Small descriptors are
 187  *              supported automatically. Note: Descriptor Type field must
 188  *              be valid.
 189  *
 190  ******************************************************************************/
 191
 192 void
 193 acpi_rs_set_resource_length(acpi_rsdesc_size total_length,
 194                             union aml_resource *aml)
 195 {
 196         acpi_rs_length resource_length;
 197
 198         ACPI_FUNCTION_ENTRY();
 199
 200         /* Length is the total descriptor length minus the header length */
 201
 202         resource_length = (acpi_rs_length)
 203             (total_length - acpi_ut_get_resource_header_length(aml));
 204
 205         /* Length is stored differently for large and small descriptors */
 206
 207         if (aml->small_header.descriptor_type & ACPI_RESOURCE_NAME_LARGE) {
 208
 209                 /* Large descriptor -- bytes 1-2 contain the 16-bit length */
 210
 211                 ACPI_MOVE_16_TO_16(&aml->large_header.resource_length,
 212                                    &resource_length);
 213         } else {
 214                 /* Small descriptor -- bits 2:0 of byte 0 contain the length */
 215
 216                 aml->small_header.descriptor_type = (u8)
 217
 218                     /* Clear any existing length, preserving descriptor type bits */
 219                     ((aml->small_header.
 220                       descriptor_type & ~ACPI_RESOURCE_NAME_SMALL_LENGTH_MASK)
 221
 222                      | resource_length);
 223         }
 224 }
 225
 226 /*******************************************************************************
 227  *
 228  * FUNCTION:    acpi_rs_set_resource_header
 229  *
 230  * PARAMETERS:  descriptor_type     - Byte to be inserted as the type
 231  *              total_length        - Length of the AML descriptor, including
 232  *                                    the header and length fields.
 233  *              Aml                 - Pointer to the raw AML descriptor
 234  *
 235  * RETURN:      None
 236  *
 237  * DESCRIPTION: Set the descriptor_type and resource_length fields of an AML
 238  *              resource descriptor, both Large and Small descriptors are
 239  *              supported automatically
 240  *
 241  ******************************************************************************/
 242
 243 void
 244 acpi_rs_set_resource_header(u8 descriptor_type,
 245                             acpi_rsdesc_size total_length,
 246                             union aml_resource *aml)
 247 {
 248         ACPI_FUNCTION_ENTRY();
 249
 250         /* Set the Resource Type */
 251
 252         aml->small_header.descriptor_type = descriptor_type;
 253
 254         /* Set the Resource Length */
 255
 256         acpi_rs_set_resource_length(total_length, aml);
 257 }
 258
 259 /*******************************************************************************
 260  *
 261  * FUNCTION:    acpi_rs_strcpy
 262  *
 263  * PARAMETERS:  Destination         - Pointer to the destination string
 264  *              Source              - Pointer to the source string
 265  *
 266  * RETURN:      String length, including NULL terminator
 267  *
 268  * DESCRIPTION: Local string copy that returns the string length, saving a
 269  *              strcpy followed by a strlen.
 270  *
 271  ******************************************************************************/
 272
 273 static u16 acpi_rs_strcpy(char *destination, char *source)
 274 {
 275         u16 i;
 276
 277         ACPI_FUNCTION_ENTRY();
 278
 279         for (i = 0; source[i]; i++) {
 280                 destination[i] = source[i];
 281         }
 282
 283         destination[i] = 0;
 284
 285         /* Return string length including the NULL terminator */
 286
 287         return ((u16) (i + 1));
 288 }
 289
 290 /*******************************************************************************
 291  *
 292  * FUNCTION:    acpi_rs_get_resource_source
 293  *
 294  * PARAMETERS:  resource_length     - Length field of the descriptor
 295  *              minimum_length      - Minimum length of the descriptor (minus
 296  *                                    any optional fields)
 297  *              resource_source     - Where the resource_source is returned
 298  *              Aml                 - Pointer to the raw AML descriptor
 299  *              string_ptr          - (optional) where to store the actual
 300  *                                    resource_source string
 301  *
 302  * RETURN:      Length of the string plus NULL terminator, rounded up to native
 303  *              word boundary
 304  *
 305  * DESCRIPTION: Copy the optional resource_source data from a raw AML descriptor
 306  *              to an internal resource descriptor
 307  *
 308  ******************************************************************************/
 309
 310 acpi_rs_length
 311 acpi_rs_get_resource_source(acpi_rs_length resource_length,
 312                             acpi_rs_length minimum_length,
 313                             struct acpi_resource_source * resource_source,
 314                             union aml_resource * aml, char *string_ptr)
 315 {
 316         acpi_rsdesc_size total_length;
 317         u8 *aml_resource_source;
 318
 319         ACPI_FUNCTION_ENTRY();
 320
 321         total_length =
 322             resource_length + sizeof(struct aml_resource_large_header);
 323         aml_resource_source = ACPI_ADD_PTR(u8, aml, minimum_length);
 324
 325         /*
 326          * resource_source is present if the length of the descriptor is longer than
 327          * the minimum length.
 328          *
 329          * Note: Some resource descriptors will have an additional null, so
 330          * we add 1 to the minimum length.
 331          */
 332         if (total_length > (acpi_rsdesc_size) (minimum_length + 1)) {
 333
 334                 /* Get the resource_source_index */
 335
 336                 resource_source->index = aml_resource_source[0];
 337
 338                 resource_source->string_ptr = string_ptr;
 339                 if (!string_ptr) {
 340                         /*
 341                          * String destination pointer is not specified; Set the String
 342                          * pointer to the end of the current resource_source structure.
 343                          */
 344                         resource_source->string_ptr =
 345                             ACPI_ADD_PTR(char, resource_source,
 346                                          sizeof(struct acpi_resource_source));
 347                 }
 348
 349                 /*
 350                  * In order for the Resource length to be a multiple of the native
 351                  * word, calculate the length of the string (+1 for NULL terminator)
 352                  * and expand to the next word multiple.
 353                  *
 354                  * Zero the entire area of the buffer.
 355                  */
 356                 total_length = (u32)
 357                 ACPI_STRLEN(ACPI_CAST_PTR(char, &aml_resource_source[1])) + 1;
 358                 total_length = (u32) ACPI_ROUND_UP_TO_NATIVE_WORD(total_length);
 359
 360                 ACPI_MEMSET(resource_source->string_ptr, 0, total_length);
 361
 362                 /* Copy the resource_source string to the destination */
 363
 364                 resource_source->string_length =
 365                     acpi_rs_strcpy(resource_source->string_ptr,
 366                                    ACPI_CAST_PTR(char,
 367                                                  &aml_resource_source[1]));
 368
 369                 return ((acpi_rs_length) total_length);
 370         }
 371
 372         /* resource_source is not present */
 373
 374         resource_source->index = 0;
 375         resource_source->string_length = 0;
 376         resource_source->string_ptr = NULL;
 377         return (0);
 378 }
 379
 380 /*******************************************************************************
 381  *
 382  * FUNCTION:    acpi_rs_set_resource_source
 383  *
 384  * PARAMETERS:  Aml                 - Pointer to the raw AML descriptor
 385  *              minimum_length      - Minimum length of the descriptor (minus
 386  *                                    any optional fields)
 387  *              resource_source     - Internal resource_source
 388
 389  *
 390  * RETURN:      Total length of the AML descriptor
 391  *
 392  * DESCRIPTION: Convert an optional resource_source from internal format to a
 393  *              raw AML resource descriptor
 394  *
 395  ******************************************************************************/
 396
 397 acpi_rsdesc_size
 398 acpi_rs_set_resource_source(union aml_resource * aml,
 399                             acpi_rs_length minimum_length,
 400                             struct acpi_resource_source * resource_source)
 401 {
 402         u8 *aml_resource_source;
 403         acpi_rsdesc_size descriptor_length;
 404
 405         ACPI_FUNCTION_ENTRY();
 406
 407         descriptor_length = minimum_length;
 408
 409         /* Non-zero string length indicates presence of a resource_source */
 410
 411         if (resource_source->string_length) {
 412
 413                 /* Point to the end of the AML descriptor */
 414
 415                 aml_resource_source = ACPI_ADD_PTR(u8, aml, minimum_length);
 416
 417                 /* Copy the resource_source_index */
 418
 419                 aml_resource_source[0] = (u8) resource_source->index;
 420
 421                 /* Copy the resource_source string */
 422
 423                 ACPI_STRCPY(ACPI_CAST_PTR(char, &aml_resource_source[1]),
 424                             resource_source->string_ptr);
 425
 426                 /*
 427                  * Add the length of the string (+ 1 for null terminator) to the
 428                  * final descriptor length
 429                  */
 430                 descriptor_length +=
 431                     ((acpi_rsdesc_size) resource_source->string_length + 1);
 432         }
 433
 434         /* Return the new total length of the AML descriptor */
 435
 436         return (descriptor_length);
 437 }
 438
 439 /*******************************************************************************
 440  *
 441  * FUNCTION:    acpi_rs_get_prt_method_data
 442  *
 443  * PARAMETERS:  Node            - Device node
 444  *              ret_buffer      - Pointer to a buffer structure for the
 445  *                                results
 446  *
 447  * RETURN:      Status
 448  *
 449  * DESCRIPTION: This function is called to get the _PRT value of an object
 450  *              contained in an object specified by the handle passed in
 451  *
 452  *              If the function fails an appropriate status will be returned
 453  *              and the contents of the callers buffer is undefined.
 454  *
 455  ******************************************************************************/
 456
 457 acpi_status
 458 acpi_rs_get_prt_method_data(struct acpi_namespace_node * node,
 459                             struct acpi_buffer * ret_buffer)
 460 {
 461         union acpi_operand_object *obj_desc;
 462         acpi_status status;
 463
 464         ACPI_FUNCTION_TRACE(rs_get_prt_method_data);
 465
 466         /* Parameters guaranteed valid by caller */
 467
 468         /* Execute the method, no parameters */
 469
 470         status = acpi_ut_evaluate_object(node, METHOD_NAME__PRT,
 471                                          ACPI_BTYPE_PACKAGE, &obj_desc);
 472         if (ACPI_FAILURE(status)) {
 473                 return_ACPI_STATUS(status);
 474         }
 475
 476         /*
 477          * Create a resource linked list from the byte stream buffer that comes
 478          * back from the _CRS method execution.
 479          */
 480         status = acpi_rs_create_pci_routing_table(obj_desc, ret_buffer);
 481
 482         /* On exit, we must delete the object returned by evaluate_object */
 483
 484         acpi_ut_remove_reference(obj_desc);
 485         return_ACPI_STATUS(status);
 486 }
 487
 488 /*******************************************************************************
 489  *
 490  * FUNCTION:    acpi_rs_get_crs_method_data
 491  *
 492  * PARAMETERS:  Node            - Device node
 493  *              ret_buffer      - Pointer to a buffer structure for the
 494  *                                results
 495  *
 496  * RETURN:      Status
 497  *
 498  * DESCRIPTION: This function is called to get the _CRS value of an object
 499  *              contained in an object specified by the handle passed in
 500  *
 501  *              If the function fails an appropriate status will be returned
 502  *              and the contents of the callers buffer is undefined.
 503  *
 504  ******************************************************************************/
 505
 506 acpi_status
 507 acpi_rs_get_crs_method_data(struct acpi_namespace_node *node,
 508                             struct acpi_buffer *ret_buffer)
 509 {
 510         union acpi_operand_object *obj_desc;
 511         acpi_status status;
 512
 513         ACPI_FUNCTION_TRACE(rs_get_crs_method_data);
 514
 515         /* Parameters guaranteed valid by caller */
 516
 517         /* Execute the method, no parameters */
 518
 519         status = acpi_ut_evaluate_object(node, METHOD_NAME__CRS,
 520                                          ACPI_BTYPE_BUFFER, &obj_desc);
 521         if (ACPI_FAILURE(status)) {
 522                 return_ACPI_STATUS(status);
 523         }
 524
 525         /*
 526          * Make the call to create a resource linked list from the
 527          * byte stream buffer that comes back from the _CRS method
 528          * execution.
 529          */
 530         status = acpi_rs_create_resource_list(obj_desc, ret_buffer);
 531
 532         /* On exit, we must delete the object returned by evaluate_object */
 533
 534         acpi_ut_remove_reference(obj_desc);
 535         return_ACPI_STATUS(status);
 536 }
 537
 538 /*******************************************************************************
 539  *
 540  * FUNCTION:    acpi_rs_get_prs_method_data
 541  *
 542  * PARAMETERS:  Node            - Device node
 543  *              ret_buffer      - Pointer to a buffer structure for the
 544  *                                results
 545  *
 546  * RETURN:      Status
 547  *
 548  * DESCRIPTION: This function is called to get the _PRS value of an object
 549  *              contained in an object specified by the handle passed in
 550  *
 551  *              If the function fails an appropriate status will be returned
 552  *              and the contents of the callers buffer is undefined.
 553  *
 554  ******************************************************************************/
 555
 556 #ifdef ACPI_FUTURE_USAGE
 557 acpi_status
 558 acpi_rs_get_prs_method_data(struct acpi_namespace_node *node,
 559                             struct acpi_buffer *ret_buffer)
 560 {
 561         union acpi_operand_object *obj_desc;
 562         acpi_status status;
 563
 564         ACPI_FUNCTION_TRACE(rs_get_prs_method_data);
 565
 566         /* Parameters guaranteed valid by caller */
 567
 568         /* Execute the method, no parameters */
 569
 570         status = acpi_ut_evaluate_object(node, METHOD_NAME__PRS,
 571                                          ACPI_BTYPE_BUFFER, &obj_desc);
 572         if (ACPI_FAILURE(status)) {
 573                 return_ACPI_STATUS(status);
 574         }
 575
 576         /*
 577          * Make the call to create a resource linked list from the
 578          * byte stream buffer that comes back from the _CRS method
 579          * execution.
 580          */
 581         status = acpi_rs_create_resource_list(obj_desc, ret_buffer);
 582
 583         /* On exit, we must delete the object returned by evaluate_object */
 584
 585         acpi_ut_remove_reference(obj_desc);
 586         return_ACPI_STATUS(status);
 587 }
 588 #endif                          /*  ACPI_FUTURE_USAGE  */
 589
 590 /*******************************************************************************
 591  *
 592  * FUNCTION:    acpi_rs_get_method_data
 593  *
 594  * PARAMETERS:  Handle          - Handle to the containing object
 595  *              Path            - Path to method, relative to Handle
 596  *              ret_buffer      - Pointer to a buffer structure for the
 597  *                                results
 598  *
 599  * RETURN:      Status
 600  *
 601  * DESCRIPTION: This function is called to get the _CRS or _PRS value of an
 602  *              object contained in an object specified by the handle passed in
 603  *
 604  *              If the function fails an appropriate status will be returned
 605  *              and the contents of the callers buffer is undefined.
 606  *
 607  ******************************************************************************/
 608
 609 acpi_status
 610 acpi_rs_get_method_data(acpi_handle handle,
 611                         char *path, struct acpi_buffer *ret_buffer)
 612 {
 613         union acpi_operand_object *obj_desc;
 614         acpi_status status;
 615
 616         ACPI_FUNCTION_TRACE(rs_get_method_data);
 617
 618         /* Parameters guaranteed valid by caller */
 619
 620         /* Execute the method, no parameters */
 621
 622         status =
 623             acpi_ut_evaluate_object(handle, path, ACPI_BTYPE_BUFFER, &obj_desc);
 624         if (ACPI_FAILURE(status)) {
 625                 return_ACPI_STATUS(status);
 626         }
 627
 628         /*
 629          * Make the call to create a resource linked list from the
 630          * byte stream buffer that comes back from the method
 631          * execution.
 632          */
 633         status = acpi_rs_create_resource_list(obj_desc, ret_buffer);
 634
 635         /* On exit, we must delete the object returned by evaluate_object */
 636
 637         acpi_ut_remove_reference(obj_desc);
 638         return_ACPI_STATUS(status);
 639 }
 640
 641 /*******************************************************************************
 642  *
 643  * FUNCTION:    acpi_rs_set_srs_method_data
 644  *
 645  * PARAMETERS:  Node            - Device node
 646  *              in_buffer       - Pointer to a buffer structure of the
 647  *                                parameter
 648  *
 649  * RETURN:      Status
 650  *
 651  * DESCRIPTION: This function is called to set the _SRS of an object contained
 652  *              in an object specified by the handle passed in
 653  *
 654  *              If the function fails an appropriate status will be returned
 655  *              and the contents of the callers buffer is undefined.
 656  *
 657  * Note: Parameters guaranteed valid by caller
 658  *
 659  ******************************************************************************/
 660
 661 acpi_status
 662 acpi_rs_set_srs_method_data(struct acpi_namespace_node *node,
 663                             struct acpi_buffer *in_buffer)
 664 {
 665         struct acpi_evaluate_info *info;
 666         union acpi_operand_object *args[2];
 667         acpi_status status;
 668         struct acpi_buffer buffer;
 669
 670         ACPI_FUNCTION_TRACE(rs_set_srs_method_data);
 671
 672         /* Allocate and initialize the evaluation information block */
 673
 674         info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
 675         if (!info) {
 676                 return_ACPI_STATUS(AE_NO_MEMORY);
 677         }
 678
 679         info->prefix_node = node;
 680         info->pathname = METHOD_NAME__SRS;
 681         info->parameters = args;
 682         info->parameter_type = ACPI_PARAM_ARGS;
 683         info->flags = ACPI_IGNORE_RETURN_VALUE;
 684
 685         /*
 686          * The in_buffer parameter will point to a linked list of
 687          * resource parameters. It needs to be formatted into a
 688          * byte stream to be sent in as an input parameter to _SRS
 689          *
 690          * Convert the linked list into a byte stream
 691          */
 692         buffer.length = ACPI_ALLOCATE_LOCAL_BUFFER;
 693         status = acpi_rs_create_aml_resources(in_buffer->pointer, &buffer);
 694         if (ACPI_FAILURE(status)) {
 695                 goto cleanup;
 696         }
 697
 698         /* Create and initialize the method parameter object */
 699
 700         args[0] = acpi_ut_create_internal_object(ACPI_TYPE_BUFFER);
 701         if (!args[0]) {
 702                 /*
 703                  * Must free the buffer allocated above (otherwise it is freed
 704                  * later)
 705                  */
 706                 ACPI_FREE(buffer.pointer);
 707                 status = AE_NO_MEMORY;
 708                 goto cleanup;
 709         }
 710
 711         args[0]->buffer.length = (u32) buffer.length;
 712         args[0]->buffer.pointer = buffer.pointer;
 713         args[0]->common.flags = AOPOBJ_DATA_VALID;
 714         args[1] = NULL;
 715
 716         /* Execute the method, no return value is expected */
 717
 718         status = acpi_ns_evaluate(info);
 719
 720         /* Clean up and return the status from acpi_ns_evaluate */
 721
 722         acpi_ut_remove_reference(args[0]);
 723
 724       cleanup:
 725         ACPI_FREE(info);
 726         return_ACPI_STATUS(status);
 727 }