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dtutils.c revision 1.1.1.20
      1 /******************************************************************************
      2  *
      3  * Module Name: dtutils.c - Utility routines for the data table compiler
      4  *
      5  *****************************************************************************/
      6 
      7 /*
      8  * Copyright (C) 2000 - 2021, 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 MERCHANTABILITY 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 "aslcompiler.h"
     45 #include "actables.h"
     46 
     47 #define _COMPONENT          DT_COMPILER
     48         ACPI_MODULE_NAME    ("dtutils")
     49 
     50 /* Local prototypes */
     51 
     52 static void
     53 DtSum (
     54     DT_SUBTABLE             *Subtable,
     55     void                    *Context,
     56     void                    *ReturnValue);
     57 
     58 
     59 /******************************************************************************
     60  *
     61  * FUNCTION:    DtError
     62  *
     63  * PARAMETERS:  Level               - Seriousness (Warning/error, etc.)
     64  *              MessageId           - Index into global message buffer
     65  *              Op                  - Parse node where error happened
     66  *              ExtraMessage        - additional error message
     67  *
     68  * RETURN:      None
     69  *
     70  * DESCRIPTION: Common error interface for data table compiler
     71  *
     72  *****************************************************************************/
     73 
     74 void
     75 DtError (
     76     UINT8                   Level,
     77     UINT16                  MessageId,
     78     DT_FIELD                *FieldObject,
     79     char                    *ExtraMessage)
     80 {
     81     UINT32                  Line = 0;
     82 
     83 
     84     /* Field object could be NULL */
     85 
     86     if (FieldObject)
     87     {
     88         Line = FieldObject->Line;
     89     }
     90 
     91     /* Check if user wants to ignore this exception */
     92 
     93     if (AslIsExceptionIgnored (AslGbl_Files[ASL_FILE_INPUT].Filename,
     94         Line, Level, MessageId))
     95     {
     96         return;
     97     }
     98 
     99     if (FieldObject)
    100     {
    101         AslCommonError (Level, MessageId,
    102             FieldObject->Line,
    103             FieldObject->Line,
    104             FieldObject->ByteOffset,
    105             FieldObject->Column,
    106             AslGbl_Files[ASL_FILE_INPUT].Filename, ExtraMessage);
    107     }
    108     else
    109     {
    110         AslCommonError (Level, MessageId, 0,
    111             0, 0, 0, 0, ExtraMessage);
    112     }
    113 }
    114 
    115 
    116 /******************************************************************************
    117  *
    118  * FUNCTION:    DtNameError
    119  *
    120  * PARAMETERS:  Level               - Seriousness (Warning/error, etc.)
    121  *              MessageId           - Index into global message buffer
    122  *              Op                  - Parse node where error happened
    123  *              ExtraMessage        - additional error message
    124  *
    125  * RETURN:      None
    126  *
    127  * DESCRIPTION: Error interface for named objects
    128  *
    129  *****************************************************************************/
    130 
    131 void
    132 DtNameError (
    133     UINT8                   Level,
    134     UINT16                  MessageId,
    135     DT_FIELD                *FieldObject,
    136     char                    *ExtraMessage)
    137 {
    138 
    139     switch (Level)
    140     {
    141     case ASL_WARNING2:
    142     case ASL_WARNING3:
    143 
    144         if (AslGbl_WarningLevel < Level)
    145         {
    146             return;
    147         }
    148         break;
    149 
    150     default:
    151 
    152         break;
    153     }
    154 
    155     if (FieldObject)
    156     {
    157         AslCommonError (Level, MessageId,
    158             FieldObject->Line,
    159             FieldObject->Line,
    160             FieldObject->ByteOffset,
    161             FieldObject->NameColumn,
    162             AslGbl_Files[ASL_FILE_INPUT].Filename, ExtraMessage);
    163     }
    164     else
    165     {
    166         AslCommonError (Level, MessageId, 0,
    167             0, 0, 0, 0, ExtraMessage);
    168     }
    169 }
    170 
    171 
    172 /*******************************************************************************
    173  *
    174  * FUNCTION:    DtFatal
    175  *
    176  * PARAMETERS:  None
    177  *
    178  * RETURN:      None
    179  *
    180  * DESCRIPTION: Dump the error log and abort the compiler. Used for serious
    181  *              compile or I/O errors
    182  *
    183  ******************************************************************************/
    184 
    185 void
    186 DtFatal (
    187     UINT16                  MessageId,
    188     DT_FIELD                *FieldObject,
    189     char                    *ExtraMessage)
    190 {
    191 
    192     DtError (ASL_ERROR, MessageId, FieldObject, ExtraMessage);
    193 
    194 /*
    195  * TBD: remove this entire function, DtFatal
    196  *
    197  * We cannot abort the compiler on error, because we may be compiling a
    198  * list of files. We must move on to the next file.
    199  */
    200 #ifdef __OBSOLETE
    201     CmCleanupAndExit ();
    202     exit (1);
    203 #endif
    204 }
    205 
    206 
    207 /*******************************************************************************
    208  *
    209  * FUNCTION:    DtDoConstant
    210  *
    211  * PARAMETERS:  String              - Only hex constants are supported,
    212  *                                    regardless of whether the 0x prefix
    213  *                                    is used
    214  *
    215  * RETURN:      Converted Integer
    216  *
    217  * DESCRIPTION: Convert a string to an integer, with overflow/error checking.
    218  *
    219  ******************************************************************************/
    220 
    221 UINT64
    222 DtDoConstant (
    223     char                    *String)
    224 {
    225     UINT64                  ConvertedInteger;
    226 
    227 
    228     /*
    229      * TBD: The ImplicitStrtoul64 function does not report overflow
    230      * conditions. The input string is simply truncated. If it is
    231      * desired to report overflow to the table compiler, this should
    232      * somehow be added here. Note: integers that are prefixed with 0x
    233      * or not are both hex integers.
    234      */
    235     ConvertedInteger = AcpiUtImplicitStrtoul64 (String);
    236     return (ConvertedInteger);
    237 }
    238 
    239 /******************************************************************************
    240  *
    241  * FUNCTION:    DtGetFieldValue
    242  *
    243  * PARAMETERS:  Field               - Current field list pointer
    244  *
    245  * RETURN:      Field value
    246  *
    247  * DESCRIPTION: Get field value
    248  *
    249  *****************************************************************************/
    250 
    251 char *
    252 DtGetFieldValue (
    253     DT_FIELD                *Field)
    254 {
    255     if (!Field)
    256     {
    257         return (NULL);
    258     }
    259 
    260     return (Field->Value);
    261 }
    262 
    263 
    264 /******************************************************************************
    265  *
    266  * FUNCTION:    DtGetFieldType
    267  *
    268  * PARAMETERS:  Info                - Data table info
    269  *
    270  * RETURN:      Field type
    271  *
    272  * DESCRIPTION: Get field type
    273  *
    274  *****************************************************************************/
    275 
    276 UINT8
    277 DtGetFieldType (
    278     ACPI_DMTABLE_INFO       *Info)
    279 {
    280     UINT8                   Type;
    281 
    282 
    283     /* DT_FLAG means that this is the start of a block of flag bits */
    284     /* TBD - we can make these a separate opcode later */
    285 
    286     if (Info->Flags & DT_FLAG)
    287     {
    288         return (DT_FIELD_TYPE_FLAGS_INTEGER);
    289     }
    290 
    291     /* Type is based upon the opcode for this field in the info table */
    292 
    293     switch (Info->Opcode)
    294     {
    295     case ACPI_DMT_FLAG0:
    296     case ACPI_DMT_FLAG1:
    297     case ACPI_DMT_FLAG2:
    298     case ACPI_DMT_FLAG3:
    299     case ACPI_DMT_FLAG4:
    300     case ACPI_DMT_FLAG5:
    301     case ACPI_DMT_FLAG6:
    302     case ACPI_DMT_FLAG7:
    303     case ACPI_DMT_FLAGS0:
    304     case ACPI_DMT_FLAGS1:
    305     case ACPI_DMT_FLAGS2:
    306     case ACPI_DMT_FLAGS4:
    307     case ACPI_DMT_FLAGS4_0:
    308     case ACPI_DMT_FLAGS4_4:
    309     case ACPI_DMT_FLAGS4_8:
    310     case ACPI_DMT_FLAGS4_12:
    311     case ACPI_DMT_FLAGS16_16:
    312 
    313         Type = DT_FIELD_TYPE_FLAG;
    314         break;
    315 
    316     case ACPI_DMT_NAME4:
    317     case ACPI_DMT_SIG:
    318     case ACPI_DMT_NAME6:
    319     case ACPI_DMT_NAME8:
    320     case ACPI_DMT_STRING:
    321     case ACPI_DMT_IVRS_UNTERMINATED_STRING:
    322 
    323         Type = DT_FIELD_TYPE_STRING;
    324         break;
    325 
    326     case ACPI_DMT_BUFFER:
    327     case ACPI_DMT_RAW_BUFFER:
    328     case ACPI_DMT_BUF7:
    329     case ACPI_DMT_BUF10:
    330     case ACPI_DMT_BUF12:
    331     case ACPI_DMT_BUF16:
    332     case ACPI_DMT_BUF128:
    333     case ACPI_DMT_PCI_PATH:
    334     case ACPI_DMT_PMTT_VENDOR:
    335 
    336         Type = DT_FIELD_TYPE_BUFFER;
    337         break;
    338 
    339     case ACPI_DMT_GAS:
    340     case ACPI_DMT_HESTNTFY:
    341     case ACPI_DMT_IORTMEM:
    342 
    343         Type = DT_FIELD_TYPE_INLINE_SUBTABLE;
    344         break;
    345 
    346     case ACPI_DMT_UNICODE:
    347     case ACPI_DMT_WPBT_UNICODE:
    348 
    349         Type = DT_FIELD_TYPE_UNICODE;
    350         break;
    351 
    352     case ACPI_DMT_UUID:
    353 
    354         Type = DT_FIELD_TYPE_UUID;
    355         break;
    356 
    357     case ACPI_DMT_DEVICE_PATH:
    358 
    359         Type = DT_FIELD_TYPE_DEVICE_PATH;
    360         break;
    361 
    362     case ACPI_DMT_LABEL:
    363 
    364         Type = DT_FIELD_TYPE_LABEL;
    365         break;
    366 
    367     default:
    368 
    369         Type = DT_FIELD_TYPE_INTEGER;
    370         break;
    371     }
    372 
    373     return (Type);
    374 }
    375 
    376 
    377 /******************************************************************************
    378  *
    379  * FUNCTION:    DtGetBufferLength
    380  *
    381  * PARAMETERS:  Buffer              - List of integers,
    382  *                                    for example "10 3A 4F 2E"
    383  *
    384  * RETURN:      Count of integer
    385  *
    386  * DESCRIPTION: Get length of bytes needed to store the integers
    387  *
    388  *****************************************************************************/
    389 
    390 UINT32
    391 DtGetBufferLength (
    392     char                    *Buffer)
    393 {
    394     UINT32                  ByteLength = 0;
    395 
    396 
    397     while (*Buffer)
    398     {
    399         if (*Buffer == ' ')
    400         {
    401             ByteLength++;
    402 
    403             while (*Buffer == ' ')
    404             {
    405                 Buffer++;
    406             }
    407         }
    408 
    409         Buffer++;
    410     }
    411 
    412     return (++ByteLength);
    413 }
    414 
    415 
    416 /******************************************************************************
    417  *
    418  * FUNCTION:    DtGetFieldLength
    419  *
    420  * PARAMETERS:  Field               - Current field
    421  *              Info                - Data table info
    422  *
    423  * RETURN:      Field length
    424  *
    425  * DESCRIPTION: Get length of bytes needed to compile the field
    426  *
    427  * Note: This function must remain in sync with AcpiDmDumpTable.
    428  *
    429  *****************************************************************************/
    430 
    431 UINT32
    432 DtGetFieldLength (
    433     DT_FIELD                *Field,
    434     ACPI_DMTABLE_INFO       *Info)
    435 {
    436     UINT32                  ByteLength = 0;
    437     char                    *Value;
    438 
    439 
    440     /* Length is based upon the opcode for this field in the info table */
    441 
    442     switch (Info->Opcode)
    443     {
    444     case ACPI_DMT_FLAG0:
    445     case ACPI_DMT_FLAG1:
    446     case ACPI_DMT_FLAG2:
    447     case ACPI_DMT_FLAG3:
    448     case ACPI_DMT_FLAG4:
    449     case ACPI_DMT_FLAG5:
    450     case ACPI_DMT_FLAG6:
    451     case ACPI_DMT_FLAG7:
    452     case ACPI_DMT_FLAGS0:
    453     case ACPI_DMT_FLAGS1:
    454     case ACPI_DMT_FLAGS2:
    455     case ACPI_DMT_FLAGS4:
    456     case ACPI_DMT_FLAGS4_0:
    457     case ACPI_DMT_FLAGS4_4:
    458     case ACPI_DMT_FLAGS4_8:
    459     case ACPI_DMT_FLAGS4_12:
    460     case ACPI_DMT_FLAGS16_16:
    461     case ACPI_DMT_LABEL:
    462     case ACPI_DMT_EXTRA_TEXT:
    463 
    464         ByteLength = 0;
    465         break;
    466 
    467     case ACPI_DMT_UINT8:
    468     case ACPI_DMT_CHKSUM:
    469     case ACPI_DMT_SPACEID:
    470     case ACPI_DMT_ACCWIDTH:
    471     case ACPI_DMT_CEDT:
    472     case ACPI_DMT_IVRS:
    473     case ACPI_DMT_IVRS_DE:
    474     case ACPI_DMT_GTDT:
    475     case ACPI_DMT_MADT:
    476     case ACPI_DMT_NHLT1:
    477     case ACPI_DMT_NHLT1a:
    478     case ACPI_DMT_PCCT:
    479     case ACPI_DMT_PMTT:
    480     case ACPI_DMT_PPTT:
    481     case ACPI_DMT_RGRT:
    482     case ACPI_DMT_SDEV:
    483     case ACPI_DMT_SRAT:
    484     case ACPI_DMT_AEST:
    485     case ACPI_DMT_AEST_RES:
    486     case ACPI_DMT_AEST_XFACE:
    487     case ACPI_DMT_AEST_XRUPT:
    488     case ACPI_DMT_ASF:
    489     case ACPI_DMT_HESTNTYP:
    490     case ACPI_DMT_FADTPM:
    491     case ACPI_DMT_EINJACT:
    492     case ACPI_DMT_EINJINST:
    493     case ACPI_DMT_ERSTACT:
    494     case ACPI_DMT_ERSTINST:
    495     case ACPI_DMT_DMAR_SCOPE:
    496     case ACPI_DMT_VIOT:
    497 
    498         ByteLength = 1;
    499         break;
    500 
    501     case ACPI_DMT_UINT16:
    502     case ACPI_DMT_DMAR:
    503     case ACPI_DMT_HEST:
    504     case ACPI_DMT_HMAT:
    505     case ACPI_DMT_NFIT:
    506     case ACPI_DMT_PCI_PATH:
    507     case ACPI_DMT_PHAT:
    508 
    509         ByteLength = 2;
    510         break;
    511 
    512     case ACPI_DMT_UINT24:
    513 
    514         ByteLength = 3;
    515         break;
    516 
    517     case ACPI_DMT_UINT32:
    518     case ACPI_DMT_AEST_CACHE:
    519     case ACPI_DMT_AEST_GIC:
    520     case ACPI_DMT_NAME4:
    521     case ACPI_DMT_SIG:
    522     case ACPI_DMT_LPIT:
    523     case ACPI_DMT_TPM2:
    524 
    525         ByteLength = 4;
    526         break;
    527 
    528     case ACPI_DMT_UINT40:
    529 
    530         ByteLength = 5;
    531         break;
    532 
    533     case ACPI_DMT_UINT48:
    534     case ACPI_DMT_NAME6:
    535 
    536         ByteLength = 6;
    537         break;
    538 
    539     case ACPI_DMT_UINT56:
    540     case ACPI_DMT_BUF7:
    541 
    542         ByteLength = 7;
    543         break;
    544 
    545     case ACPI_DMT_UINT64:
    546     case ACPI_DMT_NAME8:
    547 
    548         ByteLength = 8;
    549         break;
    550 
    551     case ACPI_DMT_STRING:
    552 
    553         Value = DtGetFieldValue (Field);
    554         if (Value)
    555         {
    556             ByteLength = strlen (Value) + 1;
    557         }
    558         else
    559         {   /* At this point, this is a fatal error */
    560 
    561             sprintf (AslGbl_MsgBuffer, "Expected \"%s\"", Info->Name);
    562             DtFatal (ASL_MSG_COMPILER_INTERNAL, NULL, AslGbl_MsgBuffer);
    563             return (0);
    564         }
    565         break;
    566 
    567     case ACPI_DMT_IVRS_UNTERMINATED_STRING:
    568 
    569         Value = DtGetFieldValue (Field);
    570         if (Value)
    571         {
    572             ByteLength = strlen (Value);
    573         }
    574         else
    575         {   /* At this point, this is a fatal error */
    576 
    577             sprintf (AslGbl_MsgBuffer, "Expected \"%s\"", Info->Name);
    578             DtFatal (ASL_MSG_COMPILER_INTERNAL, NULL, AslGbl_MsgBuffer);
    579             return (0);
    580         }
    581         break;
    582 
    583     case ACPI_DMT_GAS:
    584 
    585         ByteLength = sizeof (ACPI_GENERIC_ADDRESS);
    586         break;
    587 
    588     case ACPI_DMT_HESTNTFY:
    589 
    590         ByteLength = sizeof (ACPI_HEST_NOTIFY);
    591         break;
    592 
    593     case ACPI_DMT_IORTMEM:
    594 
    595         ByteLength = sizeof (ACPI_IORT_MEMORY_ACCESS);
    596         break;
    597 
    598     case ACPI_DMT_BUFFER:
    599     case ACPI_DMT_RAW_BUFFER:
    600     case ACPI_DMT_PMTT_VENDOR:
    601 
    602         Value = DtGetFieldValue (Field);
    603         if (Value)
    604         {
    605             ByteLength = DtGetBufferLength (Value);
    606         }
    607         else
    608         {   /* At this point, this is a fatal error */
    609 
    610             sprintf (AslGbl_MsgBuffer, "Expected \"%s\"", Info->Name);
    611             DtFatal (ASL_MSG_COMPILER_INTERNAL, NULL, AslGbl_MsgBuffer);
    612             return (0);
    613         }
    614         break;
    615 
    616     case ACPI_DMT_BUF10:
    617 
    618         ByteLength = 10;
    619         break;
    620 
    621     case ACPI_DMT_BUF12:
    622 
    623         ByteLength = 12;
    624         break;
    625 
    626     case ACPI_DMT_BUF16:
    627     case ACPI_DMT_UUID:
    628 
    629         ByteLength = 16;
    630         break;
    631 
    632     case ACPI_DMT_BUF128:
    633 
    634         ByteLength = 128;
    635         break;
    636 
    637     case ACPI_DMT_UNICODE:
    638     case ACPI_DMT_WPBT_UNICODE:
    639 
    640         Value = DtGetFieldValue (Field);
    641 
    642         /* TBD: error if Value is NULL? (as below?) */
    643 
    644         ByteLength = (strlen (Value) + 1) * sizeof (UINT16);
    645         break;
    646 
    647     default:
    648 
    649         DtFatal (ASL_MSG_COMPILER_INTERNAL, Field, "Invalid table opcode");
    650         return (0);
    651     }
    652 
    653     return (ByteLength);
    654 }
    655 
    656 
    657 /******************************************************************************
    658  *
    659  * FUNCTION:    DtSum
    660  *
    661  * PARAMETERS:  DT_WALK_CALLBACK:
    662  *              Subtable            - Subtable
    663  *              Context             - Unused
    664  *              ReturnValue         - Store the checksum of subtable
    665  *
    666  * RETURN:      Status
    667  *
    668  * DESCRIPTION: Get the checksum of subtable
    669  *
    670  *****************************************************************************/
    671 
    672 static void
    673 DtSum (
    674     DT_SUBTABLE             *Subtable,
    675     void                    *Context,
    676     void                    *ReturnValue)
    677 {
    678     UINT8                   Checksum;
    679     UINT8                   *Sum = ReturnValue;
    680 
    681 
    682     Checksum = AcpiTbChecksum (Subtable->Buffer, Subtable->Length);
    683     *Sum = (UINT8) (*Sum + Checksum);
    684 }
    685 
    686 
    687 /******************************************************************************
    688  *
    689  * FUNCTION:    DtSetTableChecksum
    690  *
    691  * PARAMETERS:  ChecksumPointer     - Where to return the checksum
    692  *
    693  * RETURN:      None
    694  *
    695  * DESCRIPTION: Set checksum of the whole data table into the checksum field
    696  *
    697  *****************************************************************************/
    698 
    699 void
    700 DtSetTableChecksum (
    701     UINT8                   *ChecksumPointer)
    702 {
    703     UINT8                   Checksum = 0;
    704     UINT8                   OldSum;
    705 
    706 
    707     DtWalkTableTree (AslGbl_RootTable, DtSum, NULL, &Checksum);
    708 
    709     OldSum = *ChecksumPointer;
    710     Checksum = (UINT8) (Checksum - OldSum);
    711 
    712     /* Compute the final checksum */
    713 
    714     Checksum = (UINT8) (0 - Checksum);
    715     *ChecksumPointer = Checksum;
    716 }
    717 
    718 
    719 /******************************************************************************
    720  *
    721  * FUNCTION:    DtSetTableLength
    722  *
    723  * PARAMETERS:  None
    724  *
    725  * RETURN:      None
    726  *
    727  * DESCRIPTION: Walk the subtables and set all the length fields
    728  *
    729  *****************************************************************************/
    730 
    731 void
    732 DtSetTableLength (
    733     void)
    734 {
    735     DT_SUBTABLE             *ParentTable;
    736     DT_SUBTABLE             *ChildTable;
    737 
    738 
    739     ParentTable = AslGbl_RootTable;
    740     ChildTable = NULL;
    741 
    742     if (!ParentTable)
    743     {
    744         return;
    745     }
    746 
    747     DtSetSubtableLength (ParentTable);
    748 
    749     while (1)
    750     {
    751         ChildTable = DtGetNextSubtable (ParentTable, ChildTable);
    752         if (ChildTable)
    753         {
    754             if (ChildTable->LengthField)
    755             {
    756                 DtSetSubtableLength (ChildTable);
    757             }
    758 
    759             if (ChildTable->Child)
    760             {
    761                 ParentTable = ChildTable;
    762                 ChildTable = NULL;
    763             }
    764             else
    765             {
    766                 ParentTable->TotalLength += ChildTable->TotalLength;
    767                 if (ParentTable->LengthField)
    768                 {
    769                     DtSetSubtableLength (ParentTable);
    770                 }
    771             }
    772         }
    773         else
    774         {
    775             ChildTable = ParentTable;
    776 
    777             if (ChildTable == AslGbl_RootTable)
    778             {
    779                 break;
    780             }
    781 
    782             ParentTable = DtGetParentSubtable (ParentTable);
    783 
    784             ParentTable->TotalLength += ChildTable->TotalLength;
    785             if (ParentTable->LengthField)
    786             {
    787                 DtSetSubtableLength (ParentTable);
    788             }
    789         }
    790     }
    791 }
    792 
    793 
    794 /******************************************************************************
    795  *
    796  * FUNCTION:    DtWalkTableTree
    797  *
    798  * PARAMETERS:  StartTable          - Subtable in the tree where walking begins
    799  *              UserFunction        - Called during the walk
    800  *              Context             - Passed to user function
    801  *              ReturnValue         - The return value of UserFunction
    802  *
    803  * RETURN:      None
    804  *
    805  * DESCRIPTION: Performs a depth-first walk of the subtable tree
    806  *
    807  *****************************************************************************/
    808 
    809 void
    810 DtWalkTableTree (
    811     DT_SUBTABLE             *StartTable,
    812     DT_WALK_CALLBACK        UserFunction,
    813     void                    *Context,
    814     void                    *ReturnValue)
    815 {
    816     DT_SUBTABLE             *ParentTable;
    817     DT_SUBTABLE             *ChildTable;
    818 
    819 
    820     ParentTable = StartTable;
    821     ChildTable = NULL;
    822 
    823     if (!ParentTable)
    824     {
    825         return;
    826     }
    827 
    828     UserFunction (ParentTable, Context, ReturnValue);
    829 
    830     while (1)
    831     {
    832         ChildTable = DtGetNextSubtable (ParentTable, ChildTable);
    833         if (ChildTable)
    834         {
    835             UserFunction (ChildTable, Context, ReturnValue);
    836 
    837             if (ChildTable->Child)
    838             {
    839                 ParentTable = ChildTable;
    840                 ChildTable = NULL;
    841             }
    842         }
    843         else
    844         {
    845             ChildTable = ParentTable;
    846             if (ChildTable == AslGbl_RootTable)
    847             {
    848                 break;
    849             }
    850 
    851             ParentTable = DtGetParentSubtable (ParentTable);
    852 
    853             if (ChildTable->Peer == StartTable)
    854             {
    855                 break;
    856             }
    857         }
    858     }
    859 }
    860