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                 /* 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
 391 acpi_status
 392 acpi_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
 603 acpi_status
 604 acpi_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 }