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rscalc.c revision 1.1.1.7
      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.h"
     45 #include "accommon.h"
     46 #include "acresrc.h"
     47 #include "acnamesp.h"
     48 
     49 
     50 #define _COMPONENT          ACPI_RESOURCES
     51         ACPI_MODULE_NAME    ("rscalc")
     52 
     53 
     54 /* Local prototypes */
     55 
     56 static UINT8
     57 AcpiRsCountSetBits (
     58     UINT16                  BitField);
     59 
     60 static ACPI_RS_LENGTH
     61 AcpiRsStructOptionLength (
     62     ACPI_RESOURCE_SOURCE    *ResourceSource);
     63 
     64 static UINT32
     65 AcpiRsStreamOptionLength (
     66     UINT32                  ResourceLength,
     67     UINT32                  MinimumTotalLength);
     68 
     69 
     70 /*******************************************************************************
     71  *
     72  * FUNCTION:    AcpiRsCountSetBits
     73  *
     74  * PARAMETERS:  BitField        - Field in which to count bits
     75  *
     76  * RETURN:      Number of bits set within the field
     77  *
     78  * DESCRIPTION: Count the number of bits set in a resource field. Used for
     79  *              (Short descriptor) interrupt and DMA lists.
     80  *
     81  ******************************************************************************/
     82 
     83 static UINT8
     84 AcpiRsCountSetBits (
     85     UINT16                  BitField)
     86 {
     87     UINT8                   BitsSet;
     88 
     89 
     90     ACPI_FUNCTION_ENTRY ();
     91 
     92 
     93     for (BitsSet = 0; BitField; BitsSet++)
     94     {
     95         /* Zero the least significant bit that is set */
     96 
     97         BitField &= (UINT16) (BitField - 1);
     98     }
     99 
    100     return (BitsSet);
    101 }
    102 
    103 
    104 /*******************************************************************************
    105  *
    106  * FUNCTION:    AcpiRsStructOptionLength
    107  *
    108  * PARAMETERS:  ResourceSource      - Pointer to optional descriptor field
    109  *
    110  * RETURN:      Status
    111  *
    112  * DESCRIPTION: Common code to handle optional ResourceSourceIndex and
    113  *              ResourceSource fields in some Large descriptors. Used during
    114  *              list-to-stream conversion
    115  *
    116  ******************************************************************************/
    117 
    118 static ACPI_RS_LENGTH
    119 AcpiRsStructOptionLength (
    120     ACPI_RESOURCE_SOURCE    *ResourceSource)
    121 {
    122     ACPI_FUNCTION_ENTRY ();
    123 
    124 
    125     /*
    126      * If the ResourceSource string is valid, return the size of the string
    127      * (StringLength includes the NULL terminator) plus the size of the
    128      * ResourceSourceIndex (1).
    129      */
    130     if (ResourceSource->StringPtr)
    131     {
    132         return ((ACPI_RS_LENGTH) (ResourceSource->StringLength + 1));
    133     }
    134 
    135     return (0);
    136 }
    137 
    138 
    139 /*******************************************************************************
    140  *
    141  * FUNCTION:    AcpiRsStreamOptionLength
    142  *
    143  * PARAMETERS:  ResourceLength      - Length from the resource header
    144  *              MinimumTotalLength  - Minimum length of this resource, before
    145  *                                    any optional fields. Includes header size
    146  *
    147  * RETURN:      Length of optional string (0 if no string present)
    148  *
    149  * DESCRIPTION: Common code to handle optional ResourceSourceIndex and
    150  *              ResourceSource fields in some Large descriptors. Used during
    151  *              stream-to-list conversion
    152  *
    153  ******************************************************************************/
    154 
    155 static UINT32
    156 AcpiRsStreamOptionLength (
    157     UINT32                  ResourceLength,
    158     UINT32                  MinimumAmlResourceLength)
    159 {
    160     UINT32                  StringLength = 0;
    161 
    162 
    163     ACPI_FUNCTION_ENTRY ();
    164 
    165 
    166     /*
    167      * The ResourceSourceIndex and ResourceSource are optional elements of
    168      * some Large-type resource descriptors.
    169      */
    170 
    171     /*
    172      * If the length of the actual resource descriptor is greater than the
    173      * ACPI spec-defined minimum length, it means that a ResourceSourceIndex
    174      * exists and is followed by a (required) null terminated string. The
    175      * string length (including the null terminator) is the resource length
    176      * minus the minimum length, minus one byte for the ResourceSourceIndex
    177      * itself.
    178      */
    179     if (ResourceLength > MinimumAmlResourceLength)
    180     {
    181         /* Compute the length of the optional string */
    182 
    183         StringLength = ResourceLength - MinimumAmlResourceLength - 1;
    184     }
    185 
    186     /*
    187      * Round the length up to a multiple of the native word in order to
    188      * guarantee that the entire resource descriptor is native word aligned
    189      */
    190     return ((UINT32) ACPI_ROUND_UP_TO_NATIVE_WORD (StringLength));
    191 }
    192 
    193 
    194 /*******************************************************************************
    195  *
    196  * FUNCTION:    AcpiRsGetAmlLength
    197  *
    198  * PARAMETERS:  Resource            - Pointer to the resource linked list
    199  *              ResourceListSize    - Size of the resource linked list
    200  *              SizeNeeded          - Where the required size is returned
    201  *
    202  * RETURN:      Status
    203  *
    204  * DESCRIPTION: Takes a linked list of internal resource descriptors and
    205  *              calculates the size buffer needed to hold the corresponding
    206  *              external resource byte stream.
    207  *
    208  ******************************************************************************/
    209 
    210 ACPI_STATUS
    211 AcpiRsGetAmlLength (
    212     ACPI_RESOURCE           *Resource,
    213     ACPI_SIZE               ResourceListSize,
    214     ACPI_SIZE               *SizeNeeded)
    215 {
    216     ACPI_SIZE               AmlSizeNeeded = 0;
    217     ACPI_RESOURCE           *ResourceEnd;
    218     ACPI_RS_LENGTH          TotalSize;
    219 
    220 
    221     ACPI_FUNCTION_TRACE (RsGetAmlLength);
    222 
    223 
    224     /* Traverse entire list of internal resource descriptors */
    225 
    226     ResourceEnd = ACPI_ADD_PTR (ACPI_RESOURCE, Resource, ResourceListSize);
    227     while (Resource < ResourceEnd)
    228     {
    229         /* Validate the descriptor type */
    230 
    231         if (Resource->Type > ACPI_RESOURCE_TYPE_MAX)
    232         {
    233             return_ACPI_STATUS (AE_AML_INVALID_RESOURCE_TYPE);
    234         }
    235 
    236         /* Sanity check the length. It must not be zero, or we loop forever */
    237 
    238         if (!Resource->Length)
    239         {
    240             return_ACPI_STATUS (AE_AML_BAD_RESOURCE_LENGTH);
    241         }
    242 
    243         /* Get the base size of the (external stream) resource descriptor */
    244 
    245         TotalSize = AcpiGbl_AmlResourceSizes [Resource->Type];
    246 
    247         /*
    248          * Augment the base size for descriptors with optional and/or
    249          * variable-length fields
    250          */
    251         switch (Resource->Type)
    252         {
    253         case ACPI_RESOURCE_TYPE_IRQ:
    254 
    255             /* Length can be 3 or 2 */
    256 
    257             if (Resource->Data.Irq.DescriptorLength == 2)
    258             {
    259                 TotalSize--;
    260             }
    261             break;
    262 
    263 
    264         case ACPI_RESOURCE_TYPE_START_DEPENDENT:
    265 
    266             /* Length can be 1 or 0 */
    267 
    268             if (Resource->Data.Irq.DescriptorLength == 0)
    269             {
    270                 TotalSize--;
    271             }
    272             break;
    273 
    274 
    275         case ACPI_RESOURCE_TYPE_VENDOR:
    276             /*
    277              * Vendor Defined Resource:
    278              * For a Vendor Specific resource, if the Length is between 1 and 7
    279              * it will be created as a Small Resource data type, otherwise it
    280              * is a Large Resource data type.
    281              */
    282             if (Resource->Data.Vendor.ByteLength > 7)
    283             {
    284                 /* Base size of a Large resource descriptor */
    285 
    286                 TotalSize = sizeof (AML_RESOURCE_LARGE_HEADER);
    287             }
    288 
    289             /* Add the size of the vendor-specific data */
    290 
    291             TotalSize = (ACPI_RS_LENGTH)
    292                 (TotalSize + Resource->Data.Vendor.ByteLength);
    293             break;
    294 
    295 
    296         case ACPI_RESOURCE_TYPE_END_TAG:
    297             /*
    298              * End Tag:
    299              * We are done -- return the accumulated total size.
    300              */
    301             *SizeNeeded = AmlSizeNeeded + TotalSize;
    302 
    303             /* Normal exit */
    304 
    305             return_ACPI_STATUS (AE_OK);
    306 
    307 
    308         case ACPI_RESOURCE_TYPE_ADDRESS16:
    309             /*
    310              * 16-Bit Address Resource:
    311              * Add the size of the optional ResourceSource info
    312              */
    313             TotalSize = (ACPI_RS_LENGTH) (TotalSize +
    314                 AcpiRsStructOptionLength (
    315                     &Resource->Data.Address16.ResourceSource));
    316             break;
    317 
    318 
    319         case ACPI_RESOURCE_TYPE_ADDRESS32:
    320             /*
    321              * 32-Bit Address Resource:
    322              * Add the size of the optional ResourceSource info
    323              */
    324             TotalSize = (ACPI_RS_LENGTH) (TotalSize +
    325                 AcpiRsStructOptionLength (
    326                     &Resource->Data.Address32.ResourceSource));
    327             break;
    328 
    329 
    330         case ACPI_RESOURCE_TYPE_ADDRESS64:
    331             /*
    332              * 64-Bit Address Resource:
    333              * Add the size of the optional ResourceSource info
    334              */
    335             TotalSize = (ACPI_RS_LENGTH) (TotalSize +
    336                 AcpiRsStructOptionLength (
    337                     &Resource->Data.Address64.ResourceSource));
    338             break;
    339 
    340 
    341         case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
    342             /*
    343              * Extended IRQ Resource:
    344              * Add the size of each additional optional interrupt beyond the
    345              * required 1 (4 bytes for each UINT32 interrupt number)
    346              */
    347             TotalSize = (ACPI_RS_LENGTH) (TotalSize +
    348                 ((Resource->Data.ExtendedIrq.InterruptCount - 1) * 4) +
    349 
    350                 /* Add the size of the optional ResourceSource info */
    351 
    352                 AcpiRsStructOptionLength (
    353                     &Resource->Data.ExtendedIrq.ResourceSource));
    354             break;
    355 
    356 
    357         case ACPI_RESOURCE_TYPE_GPIO:
    358 
    359             TotalSize = (ACPI_RS_LENGTH) (TotalSize +
    360                 (Resource->Data.Gpio.PinTableLength * 2) +
    361                 Resource->Data.Gpio.ResourceSource.StringLength +
    362                 Resource->Data.Gpio.VendorLength);
    363 
    364             break;
    365 
    366 
    367         case ACPI_RESOURCE_TYPE_SERIAL_BUS:
    368 
    369             TotalSize = AcpiGbl_AmlResourceSerialBusSizes [
    370                 Resource->Data.CommonSerialBus.Type];
    371 
    372             TotalSize = (ACPI_RS_LENGTH) (TotalSize +
    373                 Resource->Data.I2cSerialBus.ResourceSource.StringLength +
    374                 Resource->Data.I2cSerialBus.VendorLength);
    375 
    376             break;
    377 
    378         default:
    379 
    380             break;
    381         }
    382 
    383         /* Update the total */
    384 
    385         AmlSizeNeeded += TotalSize;
    386 
    387         /* Point to the next object */
    388 
    389         Resource = ACPI_ADD_PTR (ACPI_RESOURCE, Resource, Resource->Length);
    390     }
    391 
    392     /* Did not find an EndTag resource descriptor */
    393 
    394     return_ACPI_STATUS (AE_AML_NO_RESOURCE_END_TAG);
    395 }
    396 
    397 
    398 /*******************************************************************************
    399  *
    400  * FUNCTION:    AcpiRsGetListLength
    401  *
    402  * PARAMETERS:  AmlBuffer           - Pointer to the resource byte stream
    403  *              AmlBufferLength     - Size of AmlBuffer
    404  *              SizeNeeded          - Where the size needed is returned
    405  *
    406  * RETURN:      Status
    407  *
    408  * DESCRIPTION: Takes an external resource byte stream and calculates the size
    409  *              buffer needed to hold the corresponding internal resource
    410  *              descriptor linked list.
    411  *
    412  ******************************************************************************/
    413 
    414 ACPI_STATUS
    415 AcpiRsGetListLength (
    416     UINT8                   *AmlBuffer,
    417     UINT32                  AmlBufferLength,
    418     ACPI_SIZE               *SizeNeeded)
    419 {
    420     ACPI_STATUS             Status;
    421     UINT8                   *EndAml;
    422     UINT8                   *Buffer;
    423     UINT32                  BufferSize;
    424     UINT16                  Temp16;
    425     UINT16                  ResourceLength;
    426     UINT32                  ExtraStructBytes;
    427     UINT8                   ResourceIndex;
    428     UINT8                   MinimumAmlResourceLength;
    429     AML_RESOURCE            *AmlResource;
    430 
    431 
    432     ACPI_FUNCTION_TRACE (RsGetListLength);
    433 
    434 
    435     *SizeNeeded = ACPI_RS_SIZE_MIN;         /* Minimum size is one EndTag */
    436     EndAml = AmlBuffer + AmlBufferLength;
    437 
    438     /* Walk the list of AML resource descriptors */
    439 
    440     while (AmlBuffer < EndAml)
    441     {
    442         /* Validate the Resource Type and Resource Length */
    443 
    444         Status = AcpiUtValidateResource (NULL, AmlBuffer, &ResourceIndex);
    445         if (ACPI_FAILURE (Status))
    446         {
    447             /*
    448              * Exit on failure. Cannot continue because the descriptor length
    449              * may be bogus also.
    450              */
    451             return_ACPI_STATUS (Status);
    452         }
    453 
    454         AmlResource = (void *) AmlBuffer;
    455 
    456         /* Get the resource length and base (minimum) AML size */
    457 
    458         ResourceLength = AcpiUtGetResourceLength (AmlBuffer);
    459         MinimumAmlResourceLength = AcpiGbl_ResourceAmlSizes[ResourceIndex];
    460 
    461         /*
    462          * Augment the size for descriptors with optional
    463          * and/or variable length fields
    464          */
    465         ExtraStructBytes = 0;
    466         Buffer = AmlBuffer + AcpiUtGetResourceHeaderLength (AmlBuffer);
    467 
    468         switch (AcpiUtGetResourceType (AmlBuffer))
    469         {
    470         case ACPI_RESOURCE_NAME_IRQ:
    471             /*
    472              * IRQ Resource:
    473              * Get the number of bits set in the 16-bit IRQ mask
    474              */
    475             ACPI_MOVE_16_TO_16 (&Temp16, Buffer);
    476             ExtraStructBytes = AcpiRsCountSetBits (Temp16);
    477             break;
    478 
    479 
    480         case ACPI_RESOURCE_NAME_DMA:
    481             /*
    482              * DMA Resource:
    483              * Get the number of bits set in the 8-bit DMA mask
    484              */
    485             ExtraStructBytes = AcpiRsCountSetBits (*Buffer);
    486             break;
    487 
    488 
    489         case ACPI_RESOURCE_NAME_VENDOR_SMALL:
    490         case ACPI_RESOURCE_NAME_VENDOR_LARGE:
    491             /*
    492              * Vendor Resource:
    493              * Get the number of vendor data bytes
    494              */
    495             ExtraStructBytes = ResourceLength;
    496 
    497             /*
    498              * There is already one byte included in the minimum
    499              * descriptor size. If there are extra struct bytes,
    500              * subtract one from the count.
    501              */
    502             if (ExtraStructBytes)
    503             {
    504                 ExtraStructBytes--;
    505             }
    506             break;
    507 
    508 
    509         case ACPI_RESOURCE_NAME_END_TAG:
    510             /*
    511              * End Tag: This is the normal exit
    512              */
    513             return_ACPI_STATUS (AE_OK);
    514 
    515 
    516         case ACPI_RESOURCE_NAME_ADDRESS32:
    517         case ACPI_RESOURCE_NAME_ADDRESS16:
    518         case ACPI_RESOURCE_NAME_ADDRESS64:
    519             /*
    520              * Address Resource:
    521              * Add the size of the optional ResourceSource
    522              */
    523             ExtraStructBytes = AcpiRsStreamOptionLength (
    524                 ResourceLength, MinimumAmlResourceLength);
    525             break;
    526 
    527 
    528         case ACPI_RESOURCE_NAME_EXTENDED_IRQ:
    529             /*
    530              * Extended IRQ Resource:
    531              * Using the InterruptTableLength, add 4 bytes for each additional
    532              * interrupt. Note: at least one interrupt is required and is
    533              * included in the minimum descriptor size (reason for the -1)
    534              */
    535             ExtraStructBytes = (Buffer[1] - 1) * sizeof (UINT32);
    536 
    537             /* Add the size of the optional ResourceSource */
    538 
    539             ExtraStructBytes += AcpiRsStreamOptionLength (
    540                 ResourceLength - ExtraStructBytes, MinimumAmlResourceLength);
    541             break;
    542 
    543         case ACPI_RESOURCE_NAME_GPIO:
    544 
    545             /* Vendor data is optional */
    546 
    547             if (AmlResource->Gpio.VendorLength)
    548             {
    549                 ExtraStructBytes +=
    550                     AmlResource->Gpio.VendorOffset -
    551                     AmlResource->Gpio.PinTableOffset +
    552                     AmlResource->Gpio.VendorLength;
    553             }
    554             else
    555             {
    556                 ExtraStructBytes +=
    557                     AmlResource->LargeHeader.ResourceLength +
    558                     sizeof (AML_RESOURCE_LARGE_HEADER) -
    559                     AmlResource->Gpio.PinTableOffset;
    560             }
    561             break;
    562 
    563         case ACPI_RESOURCE_NAME_SERIAL_BUS:
    564 
    565             MinimumAmlResourceLength = AcpiGbl_ResourceAmlSerialBusSizes[
    566                 AmlResource->CommonSerialBus.Type];
    567             ExtraStructBytes +=
    568                 AmlResource->CommonSerialBus.ResourceLength -
    569                 MinimumAmlResourceLength;
    570             break;
    571 
    572         default:
    573 
    574             break;
    575         }
    576 
    577         /*
    578          * Update the required buffer size for the internal descriptor structs
    579          *
    580          * Important: Round the size up for the appropriate alignment. This
    581          * is a requirement on IA64.
    582          */
    583         if (AcpiUtGetResourceType (AmlBuffer) ==
    584             ACPI_RESOURCE_NAME_SERIAL_BUS)
    585         {
    586             BufferSize = AcpiGbl_ResourceStructSerialBusSizes[
    587                 AmlResource->CommonSerialBus.Type] + ExtraStructBytes;
    588         }
    589         else
    590         {
    591             BufferSize = AcpiGbl_ResourceStructSizes[ResourceIndex] +
    592                 ExtraStructBytes;
    593         }
    594 
    595         BufferSize = (UINT32) ACPI_ROUND_UP_TO_NATIVE_WORD (BufferSize);
    596         *SizeNeeded += BufferSize;
    597 
    598         ACPI_DEBUG_PRINT ((ACPI_DB_RESOURCES,
    599             "Type %.2X, AmlLength %.2X InternalLength %.2X\n",
    600             AcpiUtGetResourceType (AmlBuffer),
    601             AcpiUtGetDescriptorLength (AmlBuffer), BufferSize));
    602 
    603         /*
    604          * Point to the next resource within the AML stream using the length
    605          * contained in the resource descriptor header
    606          */
    607         AmlBuffer += AcpiUtGetDescriptorLength (AmlBuffer);
    608     }
    609 
    610     /* Did not find an EndTag resource descriptor */
    611 
    612     return_ACPI_STATUS (AE_AML_NO_RESOURCE_END_TAG);
    613 }
    614 
    615 
    616 /*******************************************************************************
    617  *
    618  * FUNCTION:    AcpiRsGetPciRoutingTableLength
    619  *
    620  * PARAMETERS:  PackageObject           - Pointer to the package object
    621  *              BufferSizeNeeded        - UINT32 pointer of the size buffer
    622  *                                        needed to properly return the
    623  *                                        parsed data
    624  *
    625  * RETURN:      Status
    626  *
    627  * DESCRIPTION: Given a package representing a PCI routing table, this
    628  *              calculates the size of the corresponding linked list of
    629  *              descriptions.
    630  *
    631  ******************************************************************************/
    632 
    633 ACPI_STATUS
    634 AcpiRsGetPciRoutingTableLength (
    635     ACPI_OPERAND_OBJECT     *PackageObject,
    636     ACPI_SIZE               *BufferSizeNeeded)
    637 {
    638     UINT32                  NumberOfElements;
    639     ACPI_SIZE               TempSizeNeeded = 0;
    640     ACPI_OPERAND_OBJECT     **TopObjectList;
    641     UINT32                  Index;
    642     ACPI_OPERAND_OBJECT     *PackageElement;
    643     ACPI_OPERAND_OBJECT     **SubObjectList;
    644     BOOLEAN                 NameFound;
    645     UINT32                  TableIndex;
    646 
    647 
    648     ACPI_FUNCTION_TRACE (RsGetPciRoutingTableLength);
    649 
    650 
    651     NumberOfElements = PackageObject->Package.Count;
    652 
    653     /*
    654      * Calculate the size of the return buffer.
    655      * The base size is the number of elements * the sizes of the
    656      * structures. Additional space for the strings is added below.
    657      * The minus one is to subtract the size of the UINT8 Source[1]
    658      * member because it is added below.
    659      *
    660      * But each PRT_ENTRY structure has a pointer to a string and
    661      * the size of that string must be found.
    662      */
    663     TopObjectList = PackageObject->Package.Elements;
    664 
    665     for (Index = 0; Index < NumberOfElements; Index++)
    666     {
    667         /* Dereference the subpackage */
    668 
    669         PackageElement = *TopObjectList;
    670 
    671         /* We must have a valid Package object */
    672 
    673         if (!PackageElement ||
    674             (PackageElement->Common.Type != ACPI_TYPE_PACKAGE))
    675         {
    676             return_ACPI_STATUS (AE_AML_OPERAND_TYPE);
    677         }
    678 
    679         /*
    680          * The SubObjectList will now point to an array of the
    681          * four IRQ elements: Address, Pin, Source and SourceIndex
    682          */
    683         SubObjectList = PackageElement->Package.Elements;
    684 
    685         /* Scan the IrqTableElements for the Source Name String */
    686 
    687         NameFound = FALSE;
    688 
    689         for (TableIndex = 0;
    690              TableIndex < PackageElement->Package.Count && !NameFound;
    691              TableIndex++)
    692         {
    693             if (*SubObjectList && /* Null object allowed */
    694 
    695                 ((ACPI_TYPE_STRING ==
    696                     (*SubObjectList)->Common.Type) ||
    697 
    698                 ((ACPI_TYPE_LOCAL_REFERENCE ==
    699                     (*SubObjectList)->Common.Type) &&
    700 
    701                     ((*SubObjectList)->Reference.Class ==
    702                         ACPI_REFCLASS_NAME))))
    703             {
    704                 NameFound = TRUE;
    705             }
    706             else
    707             {
    708                 /* Look at the next element */
    709 
    710                 SubObjectList++;
    711             }
    712         }
    713 
    714         TempSizeNeeded += (sizeof (ACPI_PCI_ROUTING_TABLE) - 4);
    715 
    716         /* Was a String type found? */
    717 
    718         if (NameFound)
    719         {
    720             if ((*SubObjectList)->Common.Type == ACPI_TYPE_STRING)
    721             {
    722                 /*
    723                  * The length String.Length field does not include the
    724                  * terminating NULL, add 1
    725                  */
    726                 TempSizeNeeded += ((ACPI_SIZE)
    727                     (*SubObjectList)->String.Length + 1);
    728             }
    729             else
    730             {
    731                 TempSizeNeeded += AcpiNsGetPathnameLength (
    732                     (*SubObjectList)->Reference.Node);
    733             }
    734         }
    735         else
    736         {
    737             /*
    738              * If no name was found, then this is a NULL, which is
    739              * translated as a UINT32 zero.
    740              */
    741             TempSizeNeeded += sizeof (UINT32);
    742         }
    743 
    744         /* Round up the size since each element must be aligned */
    745 
    746         TempSizeNeeded = ACPI_ROUND_UP_TO_64BIT (TempSizeNeeded);
    747 
    748         /* Point to the next ACPI_OPERAND_OBJECT */
    749 
    750         TopObjectList++;
    751     }
    752 
    753     /*
    754      * Add an extra element to the end of the list, essentially a
    755      * NULL terminator
    756      */
    757     *BufferSizeNeeded = TempSizeNeeded + sizeof (ACPI_PCI_ROUTING_TABLE);
    758     return_ACPI_STATUS (AE_OK);
    759 }
    760