drivers/acpi/acpica/rscalc.c

   1 /*******************************************************************************
   2  *
   3  * Module Name: rscalc - Calculate stream and list lengths
   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 <acpi/acpi.h>
  45 #include "accommon.h"
  46 #include "acresrc.h"
  47 #include "acnamesp.h"
  48
  49 #define _COMPONENT          ACPI_RESOURCES
  50 ACPI_MODULE_NAME("rscalc")
  51
  52 /* Local prototypes */
  53 static u8 acpi_rs_count_set_bits(u16 bit_field);
  54
  55 static acpi_rs_length
  56 acpi_rs_struct_option_length(struct acpi_resource_source *resource_source);
  57
  58 static u32
  59 acpi_rs_stream_option_length(u32 resource_length, u32 minimum_total_length);
  60
  61 /*******************************************************************************
  62  *
  63  * FUNCTION:    acpi_rs_count_set_bits
  64  *
  65  * PARAMETERS:  bit_field       - Field in which to count bits
  66  *
  67  * RETURN:      Number of bits set within the field
  68  *
  69  * DESCRIPTION: Count the number of bits set in a resource field. Used for
  70  *              (Short descriptor) interrupt and DMA lists.
  71  *
  72  ******************************************************************************/
  73
  74 static u8 acpi_rs_count_set_bits(u16 bit_field)
  75 {
  76         u8 bits_set;
  77
  78         ACPI_FUNCTION_ENTRY();
  79
  80         for (bits_set = 0; bit_field; bits_set++) {
  81
  82                 /* Zero the least significant bit that is set */
  83
  84                 bit_field &= (u16) (bit_field - 1);
  85         }
  86
  87         return (bits_set);
  88 }
  89
  90 /*******************************************************************************
  91  *
  92  * FUNCTION:    acpi_rs_struct_option_length
  93  *
  94  * PARAMETERS:  resource_source     - Pointer to optional descriptor field
  95  *
  96  * RETURN:      Status
  97  *
  98  * DESCRIPTION: Common code to handle optional resource_source_index and
  99  *              resource_source fields in some Large descriptors. Used during
 100  *              list-to-stream conversion
 101  *
 102  ******************************************************************************/
 103
 104 static acpi_rs_length
 105 acpi_rs_struct_option_length(struct acpi_resource_source *resource_source)
 106 {
 107         ACPI_FUNCTION_ENTRY();
 108
 109         /*
 110          * If the resource_source string is valid, return the size of the string
 111          * (string_length includes the NULL terminator) plus the size of the
 112          * resource_source_index (1).
 113          */
 114         if (resource_source->string_ptr) {
 115                 return ((acpi_rs_length) (resource_source->string_length + 1));
 116         }
 117
 118         return (0);
 119 }
 120
 121 /*******************************************************************************
 122  *
 123  * FUNCTION:    acpi_rs_stream_option_length
 124  *
 125  * PARAMETERS:  resource_length     - Length from the resource header
 126  *              minimum_total_length - Minimum length of this resource, before
 127  *                                    any optional fields. Includes header size
 128  *
 129  * RETURN:      Length of optional string (0 if no string present)
 130  *
 131  * DESCRIPTION: Common code to handle optional resource_source_index and
 132  *              resource_source fields in some Large descriptors. Used during
 133  *              stream-to-list conversion
 134  *
 135  ******************************************************************************/
 136
 137 static u32
 138 acpi_rs_stream_option_length(u32 resource_length,
 139                              u32 minimum_aml_resource_length)
 140 {
 141         u32 string_length = 0;
 142
 143         ACPI_FUNCTION_ENTRY();
 144
 145         /*
 146          * The resource_source_index and resource_source are optional elements of some
 147          * Large-type resource descriptors.
 148          */
 149
 150         /*
 151          * If the length of the actual resource descriptor is greater than the ACPI
 152          * spec-defined minimum length, it means that a resource_source_index exists
 153          * and is followed by a (required) null terminated string. The string length
 154          * (including the null terminator) is the resource length minus the minimum
 155          * length, minus one byte for the resource_source_index itself.
 156          */
 157         if (resource_length > minimum_aml_resource_length) {
 158
 159                 /* Compute the length of the optional string */
 160
 161                 string_length =
 162                     resource_length - minimum_aml_resource_length - 1;
 163         }
 164
 165         /*
 166          * Round the length up to a multiple of the native word in order to
 167          * guarantee that the entire resource descriptor is native word aligned
 168          */
 169         return ((u32) ACPI_ROUND_UP_TO_NATIVE_WORD(string_length));
 170 }
 171
 172 /*******************************************************************************
 173  *
 174  * FUNCTION:    acpi_rs_get_aml_length
 175  *
 176  * PARAMETERS:  resource            - Pointer to the resource linked list
 177  *              size_needed         - Where the required size is returned
 178  *
 179  * RETURN:      Status
 180  *
 181  * DESCRIPTION: Takes a linked list of internal resource descriptors and
 182  *              calculates the size buffer needed to hold the corresponding
 183  *              external resource byte stream.
 184  *
 185  ******************************************************************************/
 186
 187 acpi_status
 188 acpi_rs_get_aml_length(struct acpi_resource * resource, acpi_size * size_needed)
 189 {
 190         acpi_size aml_size_needed = 0;
 191         acpi_rs_length total_size;
 192
 193         ACPI_FUNCTION_TRACE(rs_get_aml_length);
 194
 195         /* Traverse entire list of internal resource descriptors */
 196
 197         while (resource) {
 198
 199                 /* Validate the descriptor type */
 200
 201                 if (resource->type > ACPI_RESOURCE_TYPE_MAX) {
 202                         return_ACPI_STATUS(AE_AML_INVALID_RESOURCE_TYPE);
 203                 }
 204
 205                 /* Get the base size of the (external stream) resource descriptor */
 206
 207                 total_size = acpi_gbl_aml_resource_sizes[resource->type];
 208
 209                 /*
 210                  * Augment the base size for descriptors with optional and/or
 211                  * variable-length fields
 212                  */
 213                 switch (resource->type) {
 214                 case ACPI_RESOURCE_TYPE_IRQ:
 215
 216                         /* Length can be 3 or 2 */
 217
 218                         if (resource->data.irq.descriptor_length == 2) {
 219                                 total_size--;
 220                         }
 221                         break;
 222
 223                 case ACPI_RESOURCE_TYPE_START_DEPENDENT:
 224
 225                         /* Length can be 1 or 0 */
 226
 227                         if (resource->data.irq.descriptor_length == 0) {
 228                                 total_size--;
 229                         }
 230                         break;
 231
 232                 case ACPI_RESOURCE_TYPE_VENDOR:
 233                         /*
 234                          * Vendor Defined Resource:
 235                          * For a Vendor Specific resource, if the Length is between 1 and 7
 236                          * it will be created as a Small Resource data type, otherwise it
 237                          * is a Large Resource data type.
 238                          */
 239                         if (resource->data.vendor.byte_length > 7) {
 240
 241                                 /* Base size of a Large resource descriptor */
 242
 243                                 total_size =
 244                                     sizeof(struct aml_resource_large_header);
 245                         }
 246
 247                         /* Add the size of the vendor-specific data */
 248
 249                         total_size = (acpi_rs_length)
 250                             (total_size + resource->data.vendor.byte_length);
 251                         break;
 252
 253                 case ACPI_RESOURCE_TYPE_END_TAG:
 254                         /*
 255                          * End Tag:
 256                          * We are done -- return the accumulated total size.
 257                          */
 258                         *size_needed = aml_size_needed + total_size;
 259
 260                         /* Normal exit */
 261
 262                         return_ACPI_STATUS(AE_OK);
 263
 264                 case ACPI_RESOURCE_TYPE_ADDRESS16:
 265                         /*
 266                          * 16-Bit Address Resource:
 267                          * Add the size of the optional resource_source info
 268                          */
 269                         total_size = (acpi_rs_length)
 270                             (total_size +
 271                              acpi_rs_struct_option_length(&resource->data.
 272                                                           address16.
 273                                                           resource_source));
 274                         break;
 275
 276                 case ACPI_RESOURCE_TYPE_ADDRESS32:
 277                         /*
 278                          * 32-Bit Address Resource:
 279                          * Add the size of the optional resource_source info
 280                          */
 281                         total_size = (acpi_rs_length)
 282                             (total_size +
 283                              acpi_rs_struct_option_length(&resource->data.
 284                                                           address32.
 285                                                           resource_source));
 286                         break;
 287
 288                 case ACPI_RESOURCE_TYPE_ADDRESS64:
 289                         /*
 290                          * 64-Bit Address Resource:
 291                          * Add the size of the optional resource_source info
 292                          */
 293                         total_size = (acpi_rs_length)
 294                             (total_size +
 295                              acpi_rs_struct_option_length(&resource->data.
 296                                                           address64.
 297                                                           resource_source));
 298                         break;
 299
 300                 case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
 301                         /*
 302                          * Extended IRQ Resource:
 303                          * Add the size of each additional optional interrupt beyond the
 304                          * required 1 (4 bytes for each u32 interrupt number)
 305                          */
 306                         total_size = (acpi_rs_length)
 307                             (total_size +
 308                              ((resource->data.extended_irq.interrupt_count -
 309                                1) * 4) +
 310                              /* Add the size of the optional resource_source info */
 311                              acpi_rs_struct_option_length(&resource->data.
 312                                                           extended_irq.
 313                                                           resource_source));
 314                         break;
 315
 316                 case ACPI_RESOURCE_TYPE_GPIO:
 317
 318                         total_size =
 319                             (acpi_rs_length) (total_size +
 320                                               (resource->data.gpio.
 321                                                pin_table_length * 2) +
 322                                               resource->data.gpio.
 323                                               resource_source.string_length +
 324                                               resource->data.gpio.
 325                                               vendor_length);
 326
 327                         break;
 328
 329                 case ACPI_RESOURCE_TYPE_SERIAL_BUS:
 330
 331                         total_size =
 332                             acpi_gbl_aml_resource_serial_bus_sizes[resource->
 333                                                                    data.
 334                                                                    common_serial_bus.
 335                                                                    type];
 336
 337                         total_size = (acpi_rs_length) (total_size +
 338                                                        resource->data.
 339                                                        i2c_serial_bus.
 340                                                        resource_source.
 341                                                        string_length +
 342                                                        resource->data.
 343                                                        i2c_serial_bus.
 344                                                        vendor_length);
 345
 346                         break;
 347
 348                 default:
 349                         break;
 350                 }
 351
 352                 /* Update the total */
 353
 354                 aml_size_needed += total_size;
 355
 356                 /* Point to the next object */
 357
 358                 resource =
 359                     ACPI_ADD_PTR(struct acpi_resource, resource,
 360                                  resource->length);
 361         }
 362
 363         /* Did not find an end_tag resource descriptor */
 364
 365         return_ACPI_STATUS(AE_AML_NO_RESOURCE_END_TAG);
 366 }
 367
 368 /*******************************************************************************
 369  *
 370  * FUNCTION:    acpi_rs_get_list_length
 371  *
 372  * PARAMETERS:  aml_buffer          - Pointer to the resource byte stream
 373  *              aml_buffer_length   - Size of aml_buffer
 374  *              size_needed         - Where the size needed is returned
 375  *
 376  * RETURN:      Status
 377  *
 378  * DESCRIPTION: Takes an external resource byte stream and calculates the size
 379  *              buffer needed to hold the corresponding internal resource
 380  *              descriptor linked list.
 381  *
 382  ******************************************************************************/
 383
 384 acpi_status
 385 acpi_rs_get_list_length(u8 * aml_buffer,
 386                         u32 aml_buffer_length, acpi_size * size_needed)
 387 {
 388         acpi_status status;
 389         u8 *end_aml;
 390         u8 *buffer;
 391         u32 buffer_size;
 392         u16 temp16;
 393         u16 resource_length;
 394         u32 extra_struct_bytes;
 395         u8 resource_index;
 396         u8 minimum_aml_resource_length;
 397         union aml_resource *aml_resource;
 398
 399         ACPI_FUNCTION_TRACE(rs_get_list_length);
 400
 401         *size_needed = ACPI_RS_SIZE_MIN;        /* Minimum size is one end_tag */
 402         end_aml = aml_buffer + aml_buffer_length;
 403
 404         /* Walk the list of AML resource descriptors */
 405
 406         while (aml_buffer < end_aml) {
 407
 408                 /* Validate the Resource Type and Resource Length */
 409
 410                 status =
 411                     acpi_ut_validate_resource(NULL, aml_buffer,
 412                                               &resource_index);
 413                 if (ACPI_FAILURE(status)) {
 414                         /*
 415                          * Exit on failure. Cannot continue because the descriptor length
 416                          * may be bogus also.
 417                          */
 418                         return_ACPI_STATUS(status);
 419                 }
 420
 421                 aml_resource = (void *)aml_buffer;
 422
 423                 /* Get the resource length and base (minimum) AML size */
 424
 425                 resource_length = acpi_ut_get_resource_length(aml_buffer);
 426                 minimum_aml_resource_length =
 427                     acpi_gbl_resource_aml_sizes[resource_index];
 428
 429                 /*
 430                  * Augment the size for descriptors with optional
 431                  * and/or variable length fields
 432                  */
 433                 extra_struct_bytes = 0;
 434                 buffer =
 435                     aml_buffer + acpi_ut_get_resource_header_length(aml_buffer);
 436
 437                 switch (acpi_ut_get_resource_type(aml_buffer)) {
 438                 case ACPI_RESOURCE_NAME_IRQ:
 439                         /*
 440                          * IRQ Resource:
 441                          * Get the number of bits set in the 16-bit IRQ mask
 442                          */
 443                         ACPI_MOVE_16_TO_16(&temp16, buffer);
 444                         extra_struct_bytes = acpi_rs_count_set_bits(temp16);
 445                         break;
 446
 447                 case ACPI_RESOURCE_NAME_DMA:
 448                         /*
 449                          * DMA Resource:
 450                          * Get the number of bits set in the 8-bit DMA mask
 451                          */
 452                         extra_struct_bytes = acpi_rs_count_set_bits(*buffer);
 453                         break;
 454
 455                 case ACPI_RESOURCE_NAME_VENDOR_SMALL:
 456                 case ACPI_RESOURCE_NAME_VENDOR_LARGE:
 457                         /*
 458                          * Vendor Resource:
 459                          * Get the number of vendor data bytes
 460                          */
 461                         extra_struct_bytes = resource_length;
 462
 463                         /*
 464                          * There is already one byte included in the minimum
 465                          * descriptor size. If there are extra struct bytes,
 466                          * subtract one from the count.
 467                          */
 468                         if (extra_struct_bytes) {
 469                                 extra_struct_bytes--;
 470                         }
 471                         break;
 472
 473                 case ACPI_RESOURCE_NAME_END_TAG:
 474                         /*
 475                          * End Tag: This is the normal exit
 476                          */
 477                         return_ACPI_STATUS(AE_OK);
 478
 479                 case ACPI_RESOURCE_NAME_ADDRESS32:
 480                 case ACPI_RESOURCE_NAME_ADDRESS16:
 481                 case ACPI_RESOURCE_NAME_ADDRESS64:
 482                         /*
 483                          * Address Resource:
 484                          * Add the size of the optional resource_source
 485                          */
 486                         extra_struct_bytes =
 487                             acpi_rs_stream_option_length(resource_length,
 488                                                          minimum_aml_resource_length);
 489                         break;
 490
 491                 case ACPI_RESOURCE_NAME_EXTENDED_IRQ:
 492                         /*
 493                          * Extended IRQ Resource:
 494                          * Using the interrupt_table_length, add 4 bytes for each additional
 495                          * interrupt. Note: at least one interrupt is required and is
 496                          * included in the minimum descriptor size (reason for the -1)
 497                          */
 498                         extra_struct_bytes = (buffer[1] - 1) * sizeof(u32);
 499
 500                         /* Add the size of the optional resource_source */
 501
 502                         extra_struct_bytes +=
 503                             acpi_rs_stream_option_length(resource_length -
 504                                                          extra_struct_bytes,
 505                                                          minimum_aml_resource_length);
 506                         break;
 507
 508                 case ACPI_RESOURCE_NAME_GPIO:
 509
 510                         /* Vendor data is optional */
 511
 512                         if (aml_resource->gpio.vendor_length) {
 513                                 extra_struct_bytes +=
 514                                     aml_resource->gpio.vendor_offset -
 515                                     aml_resource->gpio.pin_table_offset +
 516                                     aml_resource->gpio.vendor_length;
 517                         } else {
 518                                 extra_struct_bytes +=
 519                                     aml_resource->large_header.resource_length +
 520                                     sizeof(struct aml_resource_large_header) -
 521                                     aml_resource->gpio.pin_table_offset;
 522                         }
 523                         break;
 524
 525                 case ACPI_RESOURCE_NAME_SERIAL_BUS:
 526
 527                         minimum_aml_resource_length =
 528                             acpi_gbl_resource_aml_serial_bus_sizes
 529                             [aml_resource->common_serial_bus.type];
 530                         extra_struct_bytes +=
 531                             aml_resource->common_serial_bus.resource_length -
 532                             minimum_aml_resource_length;
 533                         break;
 534
 535                 default:
 536                         break;
 537                 }
 538
 539                 /*
 540                  * Update the required buffer size for the internal descriptor structs
 541                  *
 542                  * Important: Round the size up for the appropriate alignment. This
 543                  * is a requirement on IA64.
 544                  */
 545                 if (acpi_ut_get_resource_type(aml_buffer) ==
 546                     ACPI_RESOURCE_NAME_SERIAL_BUS) {
 547                         buffer_size =
 548                             acpi_gbl_resource_struct_serial_bus_sizes
 549                             [aml_resource->common_serial_bus.type] +
 550                             extra_struct_bytes;
 551                 } else {
 552                         buffer_size =
 553                             acpi_gbl_resource_struct_sizes[resource_index] +
 554                             extra_struct_bytes;
 555                 }
 556                 buffer_size = (u32)ACPI_ROUND_UP_TO_NATIVE_WORD(buffer_size);
 557
 558                 *size_needed += buffer_size;
 559
 560                 ACPI_DEBUG_PRINT((ACPI_DB_RESOURCES,
 561                                   "Type %.2X, AmlLength %.2X InternalLength %.2X\n",
 562                                   acpi_ut_get_resource_type(aml_buffer),
 563                                   acpi_ut_get_descriptor_length(aml_buffer),
 564                                   buffer_size));
 565
 566                 /*
 567                  * Point to the next resource within the AML stream using the length
 568                  * contained in the resource descriptor header
 569                  */
 570                 aml_buffer += acpi_ut_get_descriptor_length(aml_buffer);
 571         }
 572
 573         /* Did not find an end_tag resource descriptor */
 574
 575         return_ACPI_STATUS(AE_AML_NO_RESOURCE_END_TAG);
 576 }
 577
 578 /*******************************************************************************
 579  *
 580  * FUNCTION:    acpi_rs_get_pci_routing_table_length
 581  *
 582  * PARAMETERS:  package_object          - Pointer to the package object
 583  *              buffer_size_needed      - u32 pointer of the size buffer
 584  *                                        needed to properly return the
 585  *                                        parsed data
 586  *
 587  * RETURN:      Status
 588  *
 589  * DESCRIPTION: Given a package representing a PCI routing table, this
 590  *              calculates the size of the corresponding linked list of
 591  *              descriptions.
 592  *
 593  ******************************************************************************/
 594
 595 acpi_status
 596 acpi_rs_get_pci_routing_table_length(union acpi_operand_object *package_object,
 597                                      acpi_size * buffer_size_needed)
 598 {
 599         u32 number_of_elements;
 600         acpi_size temp_size_needed = 0;
 601         union acpi_operand_object **top_object_list;
 602         u32 index;
 603         union acpi_operand_object *package_element;
 604         union acpi_operand_object **sub_object_list;
 605         u8 name_found;
 606         u32 table_index;
 607
 608         ACPI_FUNCTION_TRACE(rs_get_pci_routing_table_length);
 609
 610         number_of_elements = package_object->package.count;
 611
 612         /*
 613          * Calculate the size of the return buffer.
 614          * The base size is the number of elements * the sizes of the
 615          * structures. Additional space for the strings is added below.
 616          * The minus one is to subtract the size of the u8 Source[1]
 617          * member because it is added below.
 618          *
 619          * But each PRT_ENTRY structure has a pointer to a string and
 620          * the size of that string must be found.
 621          */
 622         top_object_list = package_object->package.elements;
 623
 624         for (index = 0; index < number_of_elements; index++) {
 625
 626                 /* Dereference the sub-package */
 627
 628                 package_element = *top_object_list;
 629
 630                 /* We must have a valid Package object */
 631
 632                 if (!package_element ||
 633                     (package_element->common.type != ACPI_TYPE_PACKAGE)) {
 634                         return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
 635                 }
 636
 637                 /*
 638                  * The sub_object_list will now point to an array of the
 639                  * four IRQ elements: Address, Pin, Source and source_index
 640                  */
 641                 sub_object_list = package_element->package.elements;
 642
 643                 /* Scan the irq_table_elements for the Source Name String */
 644
 645                 name_found = FALSE;
 646
 647                 for (table_index = 0; table_index < 4 && !name_found;
 648                      table_index++) {
 649                         if (*sub_object_list && /* Null object allowed */
 650                             ((ACPI_TYPE_STRING ==
 651                               (*sub_object_list)->common.type) ||
 652                              ((ACPI_TYPE_LOCAL_REFERENCE ==
 653                                (*sub_object_list)->common.type) &&
 654                               ((*sub_object_list)->reference.class ==
 655                                ACPI_REFCLASS_NAME)))) {
 656                                 name_found = TRUE;
 657                         } else {
 658                                 /* Look at the next element */
 659
 660                                 sub_object_list++;
 661                         }
 662                 }
 663
 664                 temp_size_needed += (sizeof(struct acpi_pci_routing_table) - 4);
 665
 666                 /* Was a String type found? */
 667
 668                 if (name_found) {
 669                         if ((*sub_object_list)->common.type == ACPI_TYPE_STRING) {
 670                                 /*
 671                                  * The length String.Length field does not include the
 672                                  * terminating NULL, add 1
 673                                  */
 674                                 temp_size_needed += ((acpi_size)
 675                                                      (*sub_object_list)->string.
 676                                                      length + 1);
 677                         } else {
 678                                 temp_size_needed += acpi_ns_get_pathname_length((*sub_object_list)->reference.node);
 679                         }
 680                 } else {
 681                         /*
 682                          * If no name was found, then this is a NULL, which is
 683                          * translated as a u32 zero.
 684                          */
 685                         temp_size_needed += sizeof(u32);
 686                 }
 687
 688                 /* Round up the size since each element must be aligned */
 689
 690                 temp_size_needed = ACPI_ROUND_UP_TO_64BIT(temp_size_needed);
 691
 692                 /* Point to the next union acpi_operand_object */
 693
 694                 top_object_list++;
 695         }
 696
 697         /*
 698          * Add an extra element to the end of the list, essentially a
 699          * NULL terminator
 700          */
 701         *buffer_size_needed =
 702             temp_size_needed + sizeof(struct acpi_pci_routing_table);
 703         return_ACPI_STATUS(AE_OK);
 704 }