drivers/acpi/acpica/rscalc.c

   1 /*******************************************************************************
   2  *
   3  * Module Name: rscalc - Calculate stream and list lengths
   4  *
   5  ******************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2017, 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
 147          * some Large-type resource descriptors.
 148          */
 149
 150         /*
 151          * If the length of the actual resource descriptor is greater than the
 152          * ACPI spec-defined minimum length, it means that a resource_source_index
 153          * exists and is followed by a (required) null terminated string. The
 154          * string length (including the null terminator) is the resource length
 155          * minus the minimum length, minus one byte for the resource_source_index
 156          * itself.
 157          */
 158         if (resource_length > minimum_aml_resource_length) {
 159
 160                 /* Compute the length of the optional string */
 161
 162                 string_length =
 163                     resource_length - minimum_aml_resource_length - 1;
 164         }
 165
 166         /*
 167          * Round the length up to a multiple of the native word in order to
 168          * guarantee that the entire resource descriptor is native word aligned
 169          */
 170         return ((u32) ACPI_ROUND_UP_TO_NATIVE_WORD(string_length));
 171 }
 172
 173 /*******************************************************************************
 174  *
 175  * FUNCTION:    acpi_rs_get_aml_length
 176  *
 177  * PARAMETERS:  resource            - Pointer to the resource linked list
 178  *              resource_list_size  - Size of the resource linked list
 179  *              size_needed         - Where the required size is returned
 180  *
 181  * RETURN:      Status
 182  *
 183  * DESCRIPTION: Takes a linked list of internal resource descriptors and
 184  *              calculates the size buffer needed to hold the corresponding
 185  *              external resource byte stream.
 186  *
 187  ******************************************************************************/
 188
 189 acpi_status
 190 acpi_rs_get_aml_length(struct acpi_resource *resource,
 191                        acpi_size resource_list_size, acpi_size *size_needed)
 192 {
 193         acpi_size aml_size_needed = 0;
 194         struct acpi_resource *resource_end;
 195         acpi_rs_length total_size;
 196
 197         ACPI_FUNCTION_TRACE(rs_get_aml_length);
 198
 199         /* Traverse entire list of internal resource descriptors */
 200
 201         resource_end =
 202             ACPI_ADD_PTR(struct acpi_resource, resource, resource_list_size);
 203         while (resource < resource_end) {
 204
 205                 /* Validate the descriptor type */
 206
 207                 if (resource->type > ACPI_RESOURCE_TYPE_MAX) {
 208                         return_ACPI_STATUS(AE_AML_INVALID_RESOURCE_TYPE);
 209                 }
 210
 211                 /* Sanity check the length. It must not be zero, or we loop forever */
 212
 213                 if (!resource->length) {
 214                         return_ACPI_STATUS(AE_AML_BAD_RESOURCE_LENGTH);
 215                 }
 216
 217                 /* Get the base size of the (external stream) resource descriptor */
 218
 219                 total_size = acpi_gbl_aml_resource_sizes[resource->type];
 220
 221                 /*
 222                  * Augment the base size for descriptors with optional and/or
 223                  * variable-length fields
 224                  */
 225                 switch (resource->type) {
 226                 case ACPI_RESOURCE_TYPE_IRQ:
 227
 228                         /* Length can be 3 or 2 */
 229
 230                         if (resource->data.irq.descriptor_length == 2) {
 231                                 total_size--;
 232                         }
 233                         break;
 234
 235                 case ACPI_RESOURCE_TYPE_START_DEPENDENT:
 236
 237                         /* Length can be 1 or 0 */
 238
 239                         if (resource->data.irq.descriptor_length == 0) {
 240                                 total_size--;
 241                         }
 242                         break;
 243
 244                 case ACPI_RESOURCE_TYPE_VENDOR:
 245                         /*
 246                          * Vendor Defined Resource:
 247                          * For a Vendor Specific resource, if the Length is between 1 and 7
 248                          * it will be created as a Small Resource data type, otherwise it
 249                          * is a Large Resource data type.
 250                          */
 251                         if (resource->data.vendor.byte_length > 7) {
 252
 253                                 /* Base size of a Large resource descriptor */
 254
 255                                 total_size =
 256                                     sizeof(struct aml_resource_large_header);
 257                         }
 258
 259                         /* Add the size of the vendor-specific data */
 260
 261                         total_size = (acpi_rs_length)
 262                             (total_size + resource->data.vendor.byte_length);
 263                         break;
 264
 265                 case ACPI_RESOURCE_TYPE_END_TAG:
 266                         /*
 267                          * End Tag:
 268                          * We are done -- return the accumulated total size.
 269                          */
 270                         *size_needed = aml_size_needed + total_size;
 271
 272                         /* Normal exit */
 273
 274                         return_ACPI_STATUS(AE_OK);
 275
 276                 case ACPI_RESOURCE_TYPE_ADDRESS16:
 277                         /*
 278                          * 16-Bit Address Resource:
 279                          * Add the size of the optional resource_source info
 280                          */
 281                         total_size = (acpi_rs_length)(total_size +
 282                                                       acpi_rs_struct_option_length
 283                                                       (&resource->data.
 284                                                        address16.
 285                                                        resource_source));
 286                         break;
 287
 288                 case ACPI_RESOURCE_TYPE_ADDRESS32:
 289                         /*
 290                          * 32-Bit Address Resource:
 291                          * Add the size of the optional resource_source info
 292                          */
 293                         total_size = (acpi_rs_length)(total_size +
 294                                                       acpi_rs_struct_option_length
 295                                                       (&resource->data.
 296                                                        address32.
 297                                                        resource_source));
 298                         break;
 299
 300                 case ACPI_RESOURCE_TYPE_ADDRESS64:
 301                         /*
 302                          * 64-Bit Address Resource:
 303                          * Add the size of the optional resource_source info
 304                          */
 305                         total_size = (acpi_rs_length)(total_size +
 306                                                       acpi_rs_struct_option_length
 307                                                       (&resource->data.
 308                                                        address64.
 309                                                        resource_source));
 310                         break;
 311
 312                 case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
 313                         /*
 314                          * Extended IRQ Resource:
 315                          * Add the size of each additional optional interrupt beyond the
 316                          * required 1 (4 bytes for each u32 interrupt number)
 317                          */
 318                         total_size = (acpi_rs_length)(total_size +
 319                                                       ((resource->data.
 320                                                         extended_irq.
 321                                                         interrupt_count -
 322                                                         1) * 4) +
 323                                                       /* Add the size of the optional resource_source info */
 324                                                       acpi_rs_struct_option_length
 325                                                       (&resource->data.
 326                                                        extended_irq.
 327                                                        resource_source));
 328                         break;
 329
 330                 case ACPI_RESOURCE_TYPE_GPIO:
 331
 332                         total_size = (acpi_rs_length)(total_size +
 333                                                       (resource->data.gpio.
 334                                                        pin_table_length * 2) +
 335                                                       resource->data.gpio.
 336                                                       resource_source.
 337                                                       string_length +
 338                                                       resource->data.gpio.
 339                                                       vendor_length);
 340
 341                         break;
 342
 343                 case ACPI_RESOURCE_TYPE_PIN_FUNCTION:
 344
 345                         total_size = (acpi_rs_length)(total_size +
 346                                                       (resource->data.
 347                                                        pin_function.
 348                                                        pin_table_length * 2) +
 349                                                       resource->data.
 350                                                       pin_function.
 351                                                       resource_source.
 352                                                       string_length +
 353                                                       resource->data.
 354                                                       pin_function.
 355                                                       vendor_length);
 356
 357                         break;
 358
 359                 case ACPI_RESOURCE_TYPE_SERIAL_BUS:
 360
 361                         total_size =
 362                             acpi_gbl_aml_resource_serial_bus_sizes[resource->
 363                                                                    data.
 364                                                                    common_serial_bus.
 365                                                                    type];
 366
 367                         total_size = (acpi_rs_length)(total_size +
 368                                                       resource->data.
 369                                                       i2c_serial_bus.
 370                                                       resource_source.
 371                                                       string_length +
 372                                                       resource->data.
 373                                                       i2c_serial_bus.
 374                                                       vendor_length);
 375
 376                         break;
 377
 378                 case ACPI_RESOURCE_TYPE_PIN_CONFIG:
 379
 380                         total_size = (acpi_rs_length)(total_size +
 381                                                       (resource->data.
 382                                                        pin_config.
 383                                                        pin_table_length * 2) +
 384                                                       resource->data.pin_config.
 385                                                       resource_source.
 386                                                       string_length +
 387                                                       resource->data.pin_config.
 388                                                       vendor_length);
 389
 390                         break;
 391
 392                 default:
 393
 394                         break;
 395                 }
 396
 397                 /* Update the total */
 398
 399                 aml_size_needed += total_size;
 400
 401                 /* Point to the next object */
 402
 403                 resource =
 404                     ACPI_ADD_PTR(struct acpi_resource, resource,
 405                                  resource->length);
 406         }
 407
 408         /* Did not find an end_tag resource descriptor */
 409
 410         return_ACPI_STATUS(AE_AML_NO_RESOURCE_END_TAG);
 411 }
 412
 413 /*******************************************************************************
 414  *
 415  * FUNCTION:    acpi_rs_get_list_length
 416  *
 417  * PARAMETERS:  aml_buffer          - Pointer to the resource byte stream
 418  *              aml_buffer_length   - Size of aml_buffer
 419  *              size_needed         - Where the size needed is returned
 420  *
 421  * RETURN:      Status
 422  *
 423  * DESCRIPTION: Takes an external resource byte stream and calculates the size
 424  *              buffer needed to hold the corresponding internal resource
 425  *              descriptor linked list.
 426  *
 427  ******************************************************************************/
 428
 429 acpi_status
 430 acpi_rs_get_list_length(u8 *aml_buffer,
 431                         u32 aml_buffer_length, acpi_size *size_needed)
 432 {
 433         acpi_status status;
 434         u8 *end_aml;
 435         u8 *buffer;
 436         u32 buffer_size;
 437         u16 temp16;
 438         u16 resource_length;
 439         u32 extra_struct_bytes;
 440         u8 resource_index;
 441         u8 minimum_aml_resource_length;
 442         union aml_resource *aml_resource;
 443
 444         ACPI_FUNCTION_TRACE(rs_get_list_length);
 445
 446         *size_needed = ACPI_RS_SIZE_MIN;        /* Minimum size is one end_tag */
 447         end_aml = aml_buffer + aml_buffer_length;
 448
 449         /* Walk the list of AML resource descriptors */
 450
 451         while (aml_buffer < end_aml) {
 452
 453                 /* Validate the Resource Type and Resource Length */
 454
 455                 status =
 456                     acpi_ut_validate_resource(NULL, aml_buffer,
 457                                               &resource_index);
 458                 if (ACPI_FAILURE(status)) {
 459                         /*
 460                          * Exit on failure. Cannot continue because the descriptor length
 461                          * may be bogus also.
 462                          */
 463                         return_ACPI_STATUS(status);
 464                 }
 465
 466                 aml_resource = (void *)aml_buffer;
 467
 468                 /* Get the resource length and base (minimum) AML size */
 469
 470                 resource_length = acpi_ut_get_resource_length(aml_buffer);
 471                 minimum_aml_resource_length =
 472                     acpi_gbl_resource_aml_sizes[resource_index];
 473
 474                 /*
 475                  * Augment the size for descriptors with optional
 476                  * and/or variable length fields
 477                  */
 478                 extra_struct_bytes = 0;
 479                 buffer =
 480                     aml_buffer + acpi_ut_get_resource_header_length(aml_buffer);
 481
 482                 switch (acpi_ut_get_resource_type(aml_buffer)) {
 483                 case ACPI_RESOURCE_NAME_IRQ:
 484                         /*
 485                          * IRQ Resource:
 486                          * Get the number of bits set in the 16-bit IRQ mask
 487                          */
 488                         ACPI_MOVE_16_TO_16(&temp16, buffer);
 489                         extra_struct_bytes = acpi_rs_count_set_bits(temp16);
 490                         break;
 491
 492                 case ACPI_RESOURCE_NAME_DMA:
 493                         /*
 494                          * DMA Resource:
 495                          * Get the number of bits set in the 8-bit DMA mask
 496                          */
 497                         extra_struct_bytes = acpi_rs_count_set_bits(*buffer);
 498                         break;
 499
 500                 case ACPI_RESOURCE_NAME_VENDOR_SMALL:
 501                 case ACPI_RESOURCE_NAME_VENDOR_LARGE:
 502                         /*
 503                          * Vendor Resource:
 504                          * Get the number of vendor data bytes
 505                          */
 506                         extra_struct_bytes = resource_length;
 507
 508                         /*
 509                          * There is already one byte included in the minimum
 510                          * descriptor size. If there are extra struct bytes,
 511                          * subtract one from the count.
 512                          */
 513                         if (extra_struct_bytes) {
 514                                 extra_struct_bytes--;
 515                         }
 516                         break;
 517
 518                 case ACPI_RESOURCE_NAME_END_TAG:
 519                         /*
 520                          * End Tag: This is the normal exit
 521                          */
 522                         return_ACPI_STATUS(AE_OK);
 523
 524                 case ACPI_RESOURCE_NAME_ADDRESS32:
 525                 case ACPI_RESOURCE_NAME_ADDRESS16:
 526                 case ACPI_RESOURCE_NAME_ADDRESS64:
 527                         /*
 528                          * Address Resource:
 529                          * Add the size of the optional resource_source
 530                          */
 531                         extra_struct_bytes =
 532                             acpi_rs_stream_option_length(resource_length,
 533                                                          minimum_aml_resource_length);
 534                         break;
 535
 536                 case ACPI_RESOURCE_NAME_EXTENDED_IRQ:
 537                         /*
 538                          * Extended IRQ Resource:
 539                          * Using the interrupt_table_length, add 4 bytes for each additional
 540                          * interrupt. Note: at least one interrupt is required and is
 541                          * included in the minimum descriptor size (reason for the -1)
 542                          */
 543                         extra_struct_bytes = (buffer[1] - 1) * sizeof(u32);
 544
 545                         /* Add the size of the optional resource_source */
 546
 547                         extra_struct_bytes +=
 548                             acpi_rs_stream_option_length(resource_length -
 549                                                          extra_struct_bytes,
 550                                                          minimum_aml_resource_length);
 551                         break;
 552
 553                 case ACPI_RESOURCE_NAME_GPIO:
 554
 555                         /* Vendor data is optional */
 556
 557                         if (aml_resource->gpio.vendor_length) {
 558                                 extra_struct_bytes +=
 559                                     aml_resource->gpio.vendor_offset -
 560                                     aml_resource->gpio.pin_table_offset +
 561                                     aml_resource->gpio.vendor_length;
 562                         } else {
 563                                 extra_struct_bytes +=
 564                                     aml_resource->large_header.resource_length +
 565                                     sizeof(struct aml_resource_large_header) -
 566                                     aml_resource->gpio.pin_table_offset;
 567                         }
 568                         break;
 569
 570                 case ACPI_RESOURCE_NAME_PIN_FUNCTION:
 571
 572                         /* Vendor data is optional */
 573
 574                         if (aml_resource->pin_function.vendor_length) {
 575                                 extra_struct_bytes +=
 576                                     aml_resource->pin_function.vendor_offset -
 577                                     aml_resource->pin_function.
 578                                     pin_table_offset +
 579                                     aml_resource->pin_function.vendor_length;
 580                         } else {
 581                                 extra_struct_bytes +=
 582                                     aml_resource->large_header.resource_length +
 583                                     sizeof(struct aml_resource_large_header) -
 584                                     aml_resource->pin_function.pin_table_offset;
 585                         }
 586                         break;
 587
 588                 case ACPI_RESOURCE_NAME_SERIAL_BUS:
 589
 590                         minimum_aml_resource_length =
 591                             acpi_gbl_resource_aml_serial_bus_sizes
 592                             [aml_resource->common_serial_bus.type];
 593                         extra_struct_bytes +=
 594                             aml_resource->common_serial_bus.resource_length -
 595                             minimum_aml_resource_length;
 596                         break;
 597
 598                 case ACPI_RESOURCE_NAME_PIN_CONFIG:
 599
 600                         /* Vendor data is optional */
 601
 602                         if (aml_resource->pin_config.vendor_length) {
 603                                 extra_struct_bytes +=
 604                                     aml_resource->pin_config.vendor_offset -
 605                                     aml_resource->pin_config.pin_table_offset +
 606                                     aml_resource->pin_config.vendor_length;
 607                         } else {
 608                                 extra_struct_bytes +=
 609                                     aml_resource->large_header.resource_length +
 610                                     sizeof(struct aml_resource_large_header) -
 611                                     aml_resource->pin_config.pin_table_offset;
 612                         }
 613                         break;
 614
 615                 default:
 616
 617                         break;
 618                 }
 619
 620                 /*
 621                  * Update the required buffer size for the internal descriptor structs
 622                  *
 623                  * Important: Round the size up for the appropriate alignment. This
 624                  * is a requirement on IA64.
 625                  */
 626                 if (acpi_ut_get_resource_type(aml_buffer) ==
 627                     ACPI_RESOURCE_NAME_SERIAL_BUS) {
 628                         buffer_size =
 629                             acpi_gbl_resource_struct_serial_bus_sizes
 630                             [aml_resource->common_serial_bus.type] +
 631                             extra_struct_bytes;
 632                 } else {
 633                         buffer_size =
 634                             acpi_gbl_resource_struct_sizes[resource_index] +
 635                             extra_struct_bytes;
 636                 }
 637
 638                 buffer_size = (u32)ACPI_ROUND_UP_TO_NATIVE_WORD(buffer_size);
 639                 *size_needed += buffer_size;
 640
 641                 ACPI_DEBUG_PRINT((ACPI_DB_RESOURCES,
 642                                   "Type %.2X, AmlLength %.2X InternalLength %.2X\n",
 643                                   acpi_ut_get_resource_type(aml_buffer),
 644                                   acpi_ut_get_descriptor_length(aml_buffer),
 645                                   buffer_size));
 646
 647                 /*
 648                  * Point to the next resource within the AML stream using the length
 649                  * contained in the resource descriptor header
 650                  */
 651                 aml_buffer += acpi_ut_get_descriptor_length(aml_buffer);
 652         }
 653
 654         /* Did not find an end_tag resource descriptor */
 655
 656         return_ACPI_STATUS(AE_AML_NO_RESOURCE_END_TAG);
 657 }
 658
 659 /*******************************************************************************
 660  *
 661  * FUNCTION:    acpi_rs_get_pci_routing_table_length
 662  *
 663  * PARAMETERS:  package_object          - Pointer to the package object
 664  *              buffer_size_needed      - u32 pointer of the size buffer
 665  *                                        needed to properly return the
 666  *                                        parsed data
 667  *
 668  * RETURN:      Status
 669  *
 670  * DESCRIPTION: Given a package representing a PCI routing table, this
 671  *              calculates the size of the corresponding linked list of
 672  *              descriptions.
 673  *
 674  ******************************************************************************/
 675
 676 acpi_status
 677 acpi_rs_get_pci_routing_table_length(union acpi_operand_object *package_object,
 678                                      acpi_size *buffer_size_needed)
 679 {
 680         u32 number_of_elements;
 681         acpi_size temp_size_needed = 0;
 682         union acpi_operand_object **top_object_list;
 683         u32 index;
 684         union acpi_operand_object *package_element;
 685         union acpi_operand_object **sub_object_list;
 686         u8 name_found;
 687         u32 table_index;
 688
 689         ACPI_FUNCTION_TRACE(rs_get_pci_routing_table_length);
 690
 691         number_of_elements = package_object->package.count;
 692
 693         /*
 694          * Calculate the size of the return buffer.
 695          * The base size is the number of elements * the sizes of the
 696          * structures. Additional space for the strings is added below.
 697          * The minus one is to subtract the size of the u8 Source[1]
 698          * member because it is added below.
 699          *
 700          * But each PRT_ENTRY structure has a pointer to a string and
 701          * the size of that string must be found.
 702          */
 703         top_object_list = package_object->package.elements;
 704
 705         for (index = 0; index < number_of_elements; index++) {
 706
 707                 /* Dereference the subpackage */
 708
 709                 package_element = *top_object_list;
 710
 711                 /* We must have a valid Package object */
 712
 713                 if (!package_element ||
 714                     (package_element->common.type != ACPI_TYPE_PACKAGE)) {
 715                         return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
 716                 }
 717
 718                 /*
 719                  * The sub_object_list will now point to an array of the
 720                  * four IRQ elements: Address, Pin, Source and source_index
 721                  */
 722                 sub_object_list = package_element->package.elements;
 723
 724                 /* Scan the irq_table_elements for the Source Name String */
 725
 726                 name_found = FALSE;
 727
 728                 for (table_index = 0;
 729                      table_index < package_element->package.count
 730                      && !name_found; table_index++) {
 731                         if (*sub_object_list && /* Null object allowed */
 732                             ((ACPI_TYPE_STRING ==
 733                               (*sub_object_list)->common.type) ||
 734                              ((ACPI_TYPE_LOCAL_REFERENCE ==
 735                                (*sub_object_list)->common.type) &&
 736                               ((*sub_object_list)->reference.class ==
 737                                ACPI_REFCLASS_NAME)))) {
 738                                 name_found = TRUE;
 739                         } else {
 740                                 /* Look at the next element */
 741
 742                                 sub_object_list++;
 743                         }
 744                 }
 745
 746                 temp_size_needed += (sizeof(struct acpi_pci_routing_table) - 4);
 747
 748                 /* Was a String type found? */
 749
 750                 if (name_found) {
 751                         if ((*sub_object_list)->common.type == ACPI_TYPE_STRING) {
 752                                 /*
 753                                  * The length String.Length field does not include the
 754                                  * terminating NULL, add 1
 755                                  */
 756                                 temp_size_needed += ((acpi_size)
 757                                                      (*sub_object_list)->string.
 758                                                      length + 1);
 759                         } else {
 760                                 temp_size_needed += acpi_ns_get_pathname_length((*sub_object_list)->reference.node);
 761                         }
 762                 } else {
 763                         /*
 764                          * If no name was found, then this is a NULL, which is
 765                          * translated as a u32 zero.
 766                          */
 767                         temp_size_needed += sizeof(u32);
 768                 }
 769
 770                 /* Round up the size since each element must be aligned */
 771
 772                 temp_size_needed = ACPI_ROUND_UP_TO_64BIT(temp_size_needed);
 773
 774                 /* Point to the next union acpi_operand_object */
 775
 776                 top_object_list++;
 777         }
 778
 779         /*
 780          * Add an extra element to the end of the list, essentially a
 781          * NULL terminator
 782          */
 783         *buffer_size_needed =
 784             temp_size_needed + sizeof(struct acpi_pci_routing_table);
 785         return_ACPI_STATUS(AE_OK);
 786 }