linux/drivers/acpi/acpica/rscalc.c
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   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
  50ACPI_MODULE_NAME("rscalc")
  51
  52/* Local prototypes */
  53static u8 acpi_rs_count_set_bits(u16 bit_field);
  54
  55static acpi_rs_length
  56acpi_rs_struct_option_length(struct acpi_resource_source *resource_source);
  57
  58static u32
  59acpi_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
  74static 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
 104static acpi_rs_length
 105acpi_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
 137static u32
 138acpi_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
 187acpi_status
 188acpi_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                /* Sanity check the length. It must not be zero, or we loop forever */
 206
 207                if (!resource->length) {
 208                        return_ACPI_STATUS(AE_AML_BAD_RESOURCE_LENGTH);
 209                }
 210
 211                /* Get the base size of the (external stream) resource descriptor */
 212
 213                total_size = acpi_gbl_aml_resource_sizes[resource->type];
 214
 215                /*
 216                 * Augment the base size for descriptors with optional and/or
 217                 * variable-length fields
 218                 */
 219                switch (resource->type) {
 220                case ACPI_RESOURCE_TYPE_IRQ:
 221
 222                        /* Length can be 3 or 2 */
 223
 224                        if (resource->data.irq.descriptor_length == 2) {
 225                                total_size--;
 226                        }
 227                        break;
 228
 229                case ACPI_RESOURCE_TYPE_START_DEPENDENT:
 230
 231                        /* Length can be 1 or 0 */
 232
 233                        if (resource->data.irq.descriptor_length == 0) {
 234                                total_size--;
 235                        }
 236                        break;
 237
 238                case ACPI_RESOURCE_TYPE_VENDOR:
 239                        /*
 240                         * Vendor Defined Resource:
 241                         * For a Vendor Specific resource, if the Length is between 1 and 7
 242                         * it will be created as a Small Resource data type, otherwise it
 243                         * is a Large Resource data type.
 244                         */
 245                        if (resource->data.vendor.byte_length > 7) {
 246
 247                                /* Base size of a Large resource descriptor */
 248
 249                                total_size =
 250                                    sizeof(struct aml_resource_large_header);
 251                        }
 252
 253                        /* Add the size of the vendor-specific data */
 254
 255                        total_size = (acpi_rs_length)
 256                            (total_size + resource->data.vendor.byte_length);
 257                        break;
 258
 259                case ACPI_RESOURCE_TYPE_END_TAG:
 260                        /*
 261                         * End Tag:
 262                         * We are done -- return the accumulated total size.
 263                         */
 264                        *size_needed = aml_size_needed + total_size;
 265
 266                        /* Normal exit */
 267
 268                        return_ACPI_STATUS(AE_OK);
 269
 270                case ACPI_RESOURCE_TYPE_ADDRESS16:
 271                        /*
 272                         * 16-Bit Address Resource:
 273                         * Add the size of the optional resource_source info
 274                         */
 275                        total_size = (acpi_rs_length)
 276                            (total_size +
 277                             acpi_rs_struct_option_length(&resource->data.
 278                                                          address16.
 279                                                          resource_source));
 280                        break;
 281
 282                case ACPI_RESOURCE_TYPE_ADDRESS32:
 283                        /*
 284                         * 32-Bit Address Resource:
 285                         * Add the size of the optional resource_source info
 286                         */
 287                        total_size = (acpi_rs_length)
 288                            (total_size +
 289                             acpi_rs_struct_option_length(&resource->data.
 290                                                          address32.
 291                                                          resource_source));
 292                        break;
 293
 294                case ACPI_RESOURCE_TYPE_ADDRESS64:
 295                        /*
 296                         * 64-Bit Address Resource:
 297                         * Add the size of the optional resource_source info
 298                         */
 299                        total_size = (acpi_rs_length)
 300                            (total_size +
 301                             acpi_rs_struct_option_length(&resource->data.
 302                                                          address64.
 303                                                          resource_source));
 304                        break;
 305
 306                case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
 307                        /*
 308                         * Extended IRQ Resource:
 309                         * Add the size of each additional optional interrupt beyond the
 310                         * required 1 (4 bytes for each u32 interrupt number)
 311                         */
 312                        total_size = (acpi_rs_length)
 313                            (total_size +
 314                             ((resource->data.extended_irq.interrupt_count -
 315                               1) * 4) +
 316                             /* Add the size of the optional resource_source info */
 317                             acpi_rs_struct_option_length(&resource->data.
 318                                                          extended_irq.
 319                                                          resource_source));
 320                        break;
 321
 322                case ACPI_RESOURCE_TYPE_GPIO:
 323
 324                        total_size =
 325                            (acpi_rs_length) (total_size +
 326                                              (resource->data.gpio.
 327                                               pin_table_length * 2) +
 328                                              resource->data.gpio.
 329                                              resource_source.string_length +
 330                                              resource->data.gpio.
 331                                              vendor_length);
 332
 333                        break;
 334
 335                case ACPI_RESOURCE_TYPE_SERIAL_BUS:
 336
 337                        total_size =
 338                            acpi_gbl_aml_resource_serial_bus_sizes[resource->
 339                                                                   data.
 340                                                                   common_serial_bus.
 341                                                                   type];
 342
 343                        total_size = (acpi_rs_length) (total_size +
 344                                                       resource->data.
 345                                                       i2c_serial_bus.
 346                                                       resource_source.
 347                                                       string_length +
 348                                                       resource->data.
 349                                                       i2c_serial_bus.
 350                                                       vendor_length);
 351
 352                        break;
 353
 354                default:
 355
 356                        break;
 357                }
 358
 359                /* Update the total */
 360
 361                aml_size_needed += total_size;
 362
 363                /* Point to the next object */
 364
 365                resource =
 366                    ACPI_ADD_PTR(struct acpi_resource, resource,
 367                                 resource->length);
 368        }
 369
 370        /* Did not find an end_tag resource descriptor */
 371
 372        return_ACPI_STATUS(AE_AML_NO_RESOURCE_END_TAG);
 373}
 374
 375/*******************************************************************************
 376 *
 377 * FUNCTION:    acpi_rs_get_list_length
 378 *
 379 * PARAMETERS:  aml_buffer          - Pointer to the resource byte stream
 380 *              aml_buffer_length   - Size of aml_buffer
 381 *              size_needed         - Where the size needed is returned
 382 *
 383 * RETURN:      Status
 384 *
 385 * DESCRIPTION: Takes an external resource byte stream and calculates the size
 386 *              buffer needed to hold the corresponding internal resource
 387 *              descriptor linked list.
 388 *
 389 ******************************************************************************/
 390
 391acpi_status
 392acpi_rs_get_list_length(u8 * aml_buffer,
 393                        u32 aml_buffer_length, acpi_size * size_needed)
 394{
 395        acpi_status status;
 396        u8 *end_aml;
 397        u8 *buffer;
 398        u32 buffer_size;
 399        u16 temp16;
 400        u16 resource_length;
 401        u32 extra_struct_bytes;
 402        u8 resource_index;
 403        u8 minimum_aml_resource_length;
 404        union aml_resource *aml_resource;
 405
 406        ACPI_FUNCTION_TRACE(rs_get_list_length);
 407
 408        *size_needed = ACPI_RS_SIZE_MIN;        /* Minimum size is one end_tag */
 409        end_aml = aml_buffer + aml_buffer_length;
 410
 411        /* Walk the list of AML resource descriptors */
 412
 413        while (aml_buffer < end_aml) {
 414
 415                /* Validate the Resource Type and Resource Length */
 416
 417                status =
 418                    acpi_ut_validate_resource(NULL, aml_buffer,
 419                                              &resource_index);
 420                if (ACPI_FAILURE(status)) {
 421                        /*
 422                         * Exit on failure. Cannot continue because the descriptor length
 423                         * may be bogus also.
 424                         */
 425                        return_ACPI_STATUS(status);
 426                }
 427
 428                aml_resource = (void *)aml_buffer;
 429
 430                /* Get the resource length and base (minimum) AML size */
 431
 432                resource_length = acpi_ut_get_resource_length(aml_buffer);
 433                minimum_aml_resource_length =
 434                    acpi_gbl_resource_aml_sizes[resource_index];
 435
 436                /*
 437                 * Augment the size for descriptors with optional
 438                 * and/or variable length fields
 439                 */
 440                extra_struct_bytes = 0;
 441                buffer =
 442                    aml_buffer + acpi_ut_get_resource_header_length(aml_buffer);
 443
 444                switch (acpi_ut_get_resource_type(aml_buffer)) {
 445                case ACPI_RESOURCE_NAME_IRQ:
 446                        /*
 447                         * IRQ Resource:
 448                         * Get the number of bits set in the 16-bit IRQ mask
 449                         */
 450                        ACPI_MOVE_16_TO_16(&temp16, buffer);
 451                        extra_struct_bytes = acpi_rs_count_set_bits(temp16);
 452                        break;
 453
 454                case ACPI_RESOURCE_NAME_DMA:
 455                        /*
 456                         * DMA Resource:
 457                         * Get the number of bits set in the 8-bit DMA mask
 458                         */
 459                        extra_struct_bytes = acpi_rs_count_set_bits(*buffer);
 460                        break;
 461
 462                case ACPI_RESOURCE_NAME_VENDOR_SMALL:
 463                case ACPI_RESOURCE_NAME_VENDOR_LARGE:
 464                        /*
 465                         * Vendor Resource:
 466                         * Get the number of vendor data bytes
 467                         */
 468                        extra_struct_bytes = resource_length;
 469
 470                        /*
 471                         * There is already one byte included in the minimum
 472                         * descriptor size. If there are extra struct bytes,
 473                         * subtract one from the count.
 474                         */
 475                        if (extra_struct_bytes) {
 476                                extra_struct_bytes--;
 477                        }
 478                        break;
 479
 480                case ACPI_RESOURCE_NAME_END_TAG:
 481                        /*
 482                         * End Tag: This is the normal exit
 483                         */
 484                        return_ACPI_STATUS(AE_OK);
 485
 486                case ACPI_RESOURCE_NAME_ADDRESS32:
 487                case ACPI_RESOURCE_NAME_ADDRESS16:
 488                case ACPI_RESOURCE_NAME_ADDRESS64:
 489                        /*
 490                         * Address Resource:
 491                         * Add the size of the optional resource_source
 492                         */
 493                        extra_struct_bytes =
 494                            acpi_rs_stream_option_length(resource_length,
 495                                                         minimum_aml_resource_length);
 496                        break;
 497
 498                case ACPI_RESOURCE_NAME_EXTENDED_IRQ:
 499                        /*
 500                         * Extended IRQ Resource:
 501                         * Using the interrupt_table_length, add 4 bytes for each additional
 502                         * interrupt. Note: at least one interrupt is required and is
 503                         * included in the minimum descriptor size (reason for the -1)
 504                         */
 505                        extra_struct_bytes = (buffer[1] - 1) * sizeof(u32);
 506
 507                        /* Add the size of the optional resource_source */
 508
 509                        extra_struct_bytes +=
 510                            acpi_rs_stream_option_length(resource_length -
 511                                                         extra_struct_bytes,
 512                                                         minimum_aml_resource_length);
 513                        break;
 514
 515                case ACPI_RESOURCE_NAME_GPIO:
 516
 517                        /* Vendor data is optional */
 518
 519                        if (aml_resource->gpio.vendor_length) {
 520                                extra_struct_bytes +=
 521                                    aml_resource->gpio.vendor_offset -
 522                                    aml_resource->gpio.pin_table_offset +
 523                                    aml_resource->gpio.vendor_length;
 524                        } else {
 525                                extra_struct_bytes +=
 526                                    aml_resource->large_header.resource_length +
 527                                    sizeof(struct aml_resource_large_header) -
 528                                    aml_resource->gpio.pin_table_offset;
 529                        }
 530                        break;
 531
 532                case ACPI_RESOURCE_NAME_SERIAL_BUS:
 533
 534                        minimum_aml_resource_length =
 535                            acpi_gbl_resource_aml_serial_bus_sizes
 536                            [aml_resource->common_serial_bus.type];
 537                        extra_struct_bytes +=
 538                            aml_resource->common_serial_bus.resource_length -
 539                            minimum_aml_resource_length;
 540                        break;
 541
 542                default:
 543
 544                        break;
 545                }
 546
 547                /*
 548                 * Update the required buffer size for the internal descriptor structs
 549                 *
 550                 * Important: Round the size up for the appropriate alignment. This
 551                 * is a requirement on IA64.
 552                 */
 553                if (acpi_ut_get_resource_type(aml_buffer) ==
 554                    ACPI_RESOURCE_NAME_SERIAL_BUS) {
 555                        buffer_size =
 556                            acpi_gbl_resource_struct_serial_bus_sizes
 557                            [aml_resource->common_serial_bus.type] +
 558                            extra_struct_bytes;
 559                } else {
 560                        buffer_size =
 561                            acpi_gbl_resource_struct_sizes[resource_index] +
 562                            extra_struct_bytes;
 563                }
 564                buffer_size = (u32)ACPI_ROUND_UP_TO_NATIVE_WORD(buffer_size);
 565
 566                *size_needed += buffer_size;
 567
 568                ACPI_DEBUG_PRINT((ACPI_DB_RESOURCES,
 569                                  "Type %.2X, AmlLength %.2X InternalLength %.2X\n",
 570                                  acpi_ut_get_resource_type(aml_buffer),
 571                                  acpi_ut_get_descriptor_length(aml_buffer),
 572                                  buffer_size));
 573
 574                /*
 575                 * Point to the next resource within the AML stream using the length
 576                 * contained in the resource descriptor header
 577                 */
 578                aml_buffer += acpi_ut_get_descriptor_length(aml_buffer);
 579        }
 580
 581        /* Did not find an end_tag resource descriptor */
 582
 583        return_ACPI_STATUS(AE_AML_NO_RESOURCE_END_TAG);
 584}
 585
 586/*******************************************************************************
 587 *
 588 * FUNCTION:    acpi_rs_get_pci_routing_table_length
 589 *
 590 * PARAMETERS:  package_object          - Pointer to the package object
 591 *              buffer_size_needed      - u32 pointer of the size buffer
 592 *                                        needed to properly return the
 593 *                                        parsed data
 594 *
 595 * RETURN:      Status
 596 *
 597 * DESCRIPTION: Given a package representing a PCI routing table, this
 598 *              calculates the size of the corresponding linked list of
 599 *              descriptions.
 600 *
 601 ******************************************************************************/
 602
 603acpi_status
 604acpi_rs_get_pci_routing_table_length(union acpi_operand_object *package_object,
 605                                     acpi_size * buffer_size_needed)
 606{
 607        u32 number_of_elements;
 608        acpi_size temp_size_needed = 0;
 609        union acpi_operand_object **top_object_list;
 610        u32 index;
 611        union acpi_operand_object *package_element;
 612        union acpi_operand_object **sub_object_list;
 613        u8 name_found;
 614        u32 table_index;
 615
 616        ACPI_FUNCTION_TRACE(rs_get_pci_routing_table_length);
 617
 618        number_of_elements = package_object->package.count;
 619
 620        /*
 621         * Calculate the size of the return buffer.
 622         * The base size is the number of elements * the sizes of the
 623         * structures. Additional space for the strings is added below.
 624         * The minus one is to subtract the size of the u8 Source[1]
 625         * member because it is added below.
 626         *
 627         * But each PRT_ENTRY structure has a pointer to a string and
 628         * the size of that string must be found.
 629         */
 630        top_object_list = package_object->package.elements;
 631
 632        for (index = 0; index < number_of_elements; index++) {
 633
 634                /* Dereference the sub-package */
 635
 636                package_element = *top_object_list;
 637
 638                /* We must have a valid Package object */
 639
 640                if (!package_element ||
 641                    (package_element->common.type != ACPI_TYPE_PACKAGE)) {
 642                        return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
 643                }
 644
 645                /*
 646                 * The sub_object_list will now point to an array of the
 647                 * four IRQ elements: Address, Pin, Source and source_index
 648                 */
 649                sub_object_list = package_element->package.elements;
 650
 651                /* Scan the irq_table_elements for the Source Name String */
 652
 653                name_found = FALSE;
 654
 655                for (table_index = 0;
 656                     table_index < package_element->package.count
 657                     && !name_found; table_index++) {
 658                        if (*sub_object_list && /* Null object allowed */
 659                            ((ACPI_TYPE_STRING ==
 660                              (*sub_object_list)->common.type) ||
 661                             ((ACPI_TYPE_LOCAL_REFERENCE ==
 662                               (*sub_object_list)->common.type) &&
 663                              ((*sub_object_list)->reference.class ==
 664                               ACPI_REFCLASS_NAME)))) {
 665                                name_found = TRUE;
 666                        } else {
 667                                /* Look at the next element */
 668
 669                                sub_object_list++;
 670                        }
 671                }
 672
 673                temp_size_needed += (sizeof(struct acpi_pci_routing_table) - 4);
 674
 675                /* Was a String type found? */
 676
 677                if (name_found) {
 678                        if ((*sub_object_list)->common.type == ACPI_TYPE_STRING) {
 679                                /*
 680                                 * The length String.Length field does not include the
 681                                 * terminating NULL, add 1
 682                                 */
 683                                temp_size_needed += ((acpi_size)
 684                                                     (*sub_object_list)->string.
 685                                                     length + 1);
 686                        } else {
 687                                temp_size_needed += acpi_ns_get_pathname_length((*sub_object_list)->reference.node);
 688                        }
 689                } else {
 690                        /*
 691                         * If no name was found, then this is a NULL, which is
 692                         * translated as a u32 zero.
 693                         */
 694                        temp_size_needed += sizeof(u32);
 695                }
 696
 697                /* Round up the size since each element must be aligned */
 698
 699                temp_size_needed = ACPI_ROUND_UP_TO_64BIT(temp_size_needed);
 700
 701                /* Point to the next union acpi_operand_object */
 702
 703                top_object_list++;
 704        }
 705
 706        /*
 707         * Add an extra element to the end of the list, essentially a
 708         * NULL terminator
 709         */
 710        *buffer_size_needed =
 711            temp_size_needed + sizeof(struct acpi_pci_routing_table);
 712        return_ACPI_STATUS(AE_OK);
 713}
 714