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      1 /******************************************************************************
      2  *
      3  * Module Name: tbutils - ACPI Table utilities
      4  *
      5  *****************************************************************************/
      6 
      7 /******************************************************************************
      8  *
      9  * 1. Copyright Notice
     10  *
     11  * Some or all of this work - Copyright (c) 1999 - 2025, Intel Corp.
     12  * All rights reserved.
     13  *
     14  * 2. License
     15  *
     16  * 2.1. This is your license from Intel Corp. under its intellectual property
     17  * rights. You may have additional license terms from the party that provided
     18  * you this software, covering your right to use that party's intellectual
     19  * property rights.
     20  *
     21  * 2.2. Intel grants, free of charge, to any person ("Licensee") obtaining a
     22  * copy of the source code appearing in this file ("Covered Code") an
     23  * irrevocable, perpetual, worldwide license under Intel's copyrights in the
     24  * base code distributed originally by Intel ("Original Intel Code") to copy,
     25  * make derivatives, distribute, use and display any portion of the Covered
     26  * Code in any form, with the right to sublicense such rights; and
     27  *
     28  * 2.3. Intel grants Licensee a non-exclusive and non-transferable patent
     29  * license (with the right to sublicense), under only those claims of Intel
     30  * patents that are infringed by the Original Intel Code, to make, use, sell,
     31  * offer to sell, and import the Covered Code and derivative works thereof
     32  * solely to the minimum extent necessary to exercise the above copyright
     33  * license, and in no event shall the patent license extend to any additions
     34  * to or modifications of the Original Intel Code. No other license or right
     35  * is granted directly or by implication, estoppel or otherwise;
     36  *
     37  * The above copyright and patent license is granted only if the following
     38  * conditions are met:
     39  *
     40  * 3. Conditions
     41  *
     42  * 3.1. Redistribution of Source with Rights to Further Distribute Source.
     43  * Redistribution of source code of any substantial portion of the Covered
     44  * Code or modification with rights to further distribute source must include
     45  * the above Copyright Notice, the above License, this list of Conditions,
     46  * and the following Disclaimer and Export Compliance provision. In addition,
     47  * Licensee must cause all Covered Code to which Licensee contributes to
     48  * contain a file documenting the changes Licensee made to create that Covered
     49  * Code and the date of any change. Licensee must include in that file the
     50  * documentation of any changes made by any predecessor Licensee. Licensee
     51  * must include a prominent statement that the modification is derived,
     52  * directly or indirectly, from Original Intel Code.
     53  *
     54  * 3.2. Redistribution of Source with no Rights to Further Distribute Source.
     55  * Redistribution of source code of any substantial portion of the Covered
     56  * Code or modification without rights to further distribute source must
     57  * include the following Disclaimer and Export Compliance provision in the
     58  * documentation and/or other materials provided with distribution. In
     59  * addition, Licensee may not authorize further sublicense of source of any
     60  * portion of the Covered Code, and must include terms to the effect that the
     61  * license from Licensee to its licensee is limited to the intellectual
     62  * property embodied in the software Licensee provides to its licensee, and
     63  * not to intellectual property embodied in modifications its licensee may
     64  * make.
     65  *
     66  * 3.3. Redistribution of Executable. Redistribution in executable form of any
     67  * substantial portion of the Covered Code or modification must reproduce the
     68  * above Copyright Notice, and the following Disclaimer and Export Compliance
     69  * provision in the documentation and/or other materials provided with the
     70  * distribution.
     71  *
     72  * 3.4. Intel retains all right, title, and interest in and to the Original
     73  * Intel Code.
     74  *
     75  * 3.5. Neither the name Intel nor any other trademark owned or controlled by
     76  * Intel shall be used in advertising or otherwise to promote the sale, use or
     77  * other dealings in products derived from or relating to the Covered Code
     78  * without prior written authorization from Intel.
     79  *
     80  * 4. Disclaimer and Export Compliance
     81  *
     82  * 4.1. INTEL MAKES NO WARRANTY OF ANY KIND REGARDING ANY SOFTWARE PROVIDED
     83  * HERE. ANY SOFTWARE ORIGINATING FROM INTEL OR DERIVED FROM INTEL SOFTWARE
     84  * IS PROVIDED "AS IS," AND INTEL WILL NOT PROVIDE ANY SUPPORT, ASSISTANCE,
     85  * INSTALLATION, TRAINING OR OTHER SERVICES. INTEL WILL NOT PROVIDE ANY
     86  * UPDATES, ENHANCEMENTS OR EXTENSIONS. INTEL SPECIFICALLY DISCLAIMS ANY
     87  * IMPLIED WARRANTIES OF MERCHANTABILITY, NONINFRINGEMENT AND FITNESS FOR A
     88  * PARTICULAR PURPOSE.
     89  *
     90  * 4.2. IN NO EVENT SHALL INTEL HAVE ANY LIABILITY TO LICENSEE, ITS LICENSEES
     91  * OR ANY OTHER THIRD PARTY, FOR ANY LOST PROFITS, LOST DATA, LOSS OF USE OR
     92  * COSTS OF PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, OR FOR ANY INDIRECT,
     93  * SPECIAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THIS AGREEMENT, UNDER ANY
     94  * CAUSE OF ACTION OR THEORY OF LIABILITY, AND IRRESPECTIVE OF WHETHER INTEL
     95  * HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES. THESE LIMITATIONS
     96  * SHALL APPLY NOTWITHSTANDING THE FAILURE OF THE ESSENTIAL PURPOSE OF ANY
     97  * LIMITED REMEDY.
     98  *
     99  * 4.3. Licensee shall not export, either directly or indirectly, any of this
    100  * software or system incorporating such software without first obtaining any
    101  * required license or other approval from the U. S. Department of Commerce or
    102  * any other agency or department of the United States Government. In the
    103  * event Licensee exports any such software from the United States or
    104  * re-exports any such software from a foreign destination, Licensee shall
    105  * ensure that the distribution and export/re-export of the software is in
    106  * compliance with all laws, regulations, orders, or other restrictions of the
    107  * U.S. Export Administration Regulations. Licensee agrees that neither it nor
    108  * any of its subsidiaries will export/re-export any technical data, process,
    109  * software, or service, directly or indirectly, to any country for which the
    110  * United States government or any agency thereof requires an export license,
    111  * other governmental approval, or letter of assurance, without first obtaining
    112  * such license, approval or letter.
    113  *
    114  *****************************************************************************
    115  *
    116  * Alternatively, you may choose to be licensed under the terms of the
    117  * following license:
    118  *
    119  * Redistribution and use in source and binary forms, with or without
    120  * modification, are permitted provided that the following conditions
    121  * are met:
    122  * 1. Redistributions of source code must retain the above copyright
    123  *    notice, this list of conditions, and the following disclaimer,
    124  *    without modification.
    125  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
    126  *    substantially similar to the "NO WARRANTY" disclaimer below
    127  *    ("Disclaimer") and any redistribution must be conditioned upon
    128  *    including a substantially similar Disclaimer requirement for further
    129  *    binary redistribution.
    130  * 3. Neither the names of the above-listed copyright holders nor the names
    131  *    of any contributors may be used to endorse or promote products derived
    132  *    from this software without specific prior written permission.
    133  *
    134  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    135  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    136  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    137  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    138  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    139  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    140  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    141  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    142  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    143  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    144  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
    145  *
    146  * Alternatively, you may choose to be licensed under the terms of the
    147  * GNU General Public License ("GPL") version 2 as published by the Free
    148  * Software Foundation.
    149  *
    150  *****************************************************************************/
    151 
    152 #include "acpi.h"
    153 #include "accommon.h"
    154 #include "actables.h"
    155 
    156 #define _COMPONENT          ACPI_TABLES
    157         ACPI_MODULE_NAME    ("tbutils")
    158 
    159 
    160 /* Local prototypes */
    161 
    162 static ACPI_PHYSICAL_ADDRESS
    163 AcpiTbGetRootTableEntry (
    164     UINT8                   *TableEntry,
    165     UINT32                  TableEntrySize);
    166 
    167 
    168 #if (!ACPI_REDUCED_HARDWARE)
    169 /*******************************************************************************
    170  *
    171  * FUNCTION:    AcpiTbInitializeFacs
    172  *
    173  * PARAMETERS:  None
    174  *
    175  * RETURN:      Status
    176  *
    177  * DESCRIPTION: Create a permanent mapping for the FADT and save it in a global
    178  *              for accessing the Global Lock and Firmware Waking Vector
    179  *
    180  ******************************************************************************/
    181 
    182 ACPI_STATUS
    183 AcpiTbInitializeFacs (
    184     void)
    185 {
    186     ACPI_TABLE_FACS         *Facs;
    187 
    188 
    189     /* If Hardware Reduced flag is set, there is no FACS */
    190 
    191     if (AcpiGbl_ReducedHardware)
    192     {
    193         AcpiGbl_FACS = NULL;
    194         return (AE_OK);
    195     }
    196     else if (AcpiGbl_FADT.XFacs &&
    197          (!AcpiGbl_FADT.Facs || !AcpiGbl_Use32BitFacsAddresses))
    198     {
    199         (void) AcpiGetTableByIndex (AcpiGbl_XFacsIndex,
    200             ACPI_CAST_INDIRECT_PTR (ACPI_TABLE_HEADER, &Facs));
    201         AcpiGbl_FACS = Facs;
    202     }
    203     else if (AcpiGbl_FADT.Facs)
    204     {
    205         (void) AcpiGetTableByIndex (AcpiGbl_FacsIndex,
    206             ACPI_CAST_INDIRECT_PTR (ACPI_TABLE_HEADER, &Facs));
    207         AcpiGbl_FACS = Facs;
    208     }
    209 
    210     /* If there is no FACS, just continue. There was already an error msg */
    211 
    212     return (AE_OK);
    213 }
    214 #endif /* !ACPI_REDUCED_HARDWARE */
    215 
    216 
    217 /*******************************************************************************
    218  *
    219  * FUNCTION:    AcpiTbCheckDsdtHeader
    220  *
    221  * PARAMETERS:  None
    222  *
    223  * RETURN:      None
    224  *
    225  * DESCRIPTION: Quick compare to check validity of the DSDT. This will detect
    226  *              if the DSDT has been replaced from outside the OS and/or if
    227  *              the DSDT header has been corrupted.
    228  *
    229  ******************************************************************************/
    230 
    231 void
    232 AcpiTbCheckDsdtHeader (
    233     void)
    234 {
    235 
    236     /* Compare original length and checksum to current values */
    237 
    238     if (AcpiGbl_OriginalDsdtHeader.Length != AcpiGbl_DSDT->Length ||
    239         AcpiGbl_OriginalDsdtHeader.Checksum != AcpiGbl_DSDT->Checksum)
    240     {
    241         ACPI_BIOS_ERROR ((AE_INFO,
    242             "The DSDT has been corrupted or replaced - "
    243             "old, new headers below"));
    244 
    245         AcpiTbPrintTableHeader (0, &AcpiGbl_OriginalDsdtHeader);
    246         AcpiTbPrintTableHeader (0, AcpiGbl_DSDT);
    247 
    248         /* Disable further error messages */
    249 
    250         AcpiGbl_OriginalDsdtHeader.Length = AcpiGbl_DSDT->Length;
    251         AcpiGbl_OriginalDsdtHeader.Checksum = AcpiGbl_DSDT->Checksum;
    252     }
    253 }
    254 
    255 
    256 /*******************************************************************************
    257  *
    258  * FUNCTION:    AcpiTbCopyDsdt
    259  *
    260  * PARAMETERS:  TableIndex          - Index of installed table to copy
    261  *
    262  * RETURN:      The copied DSDT
    263  *
    264  * DESCRIPTION: Implements a subsystem option to copy the DSDT to local memory.
    265  *              Some very bad BIOSs are known to either corrupt the DSDT or
    266  *              install a new, bad DSDT. This copy works around the problem.
    267  *
    268  ******************************************************************************/
    269 
    270 ACPI_TABLE_HEADER *
    271 AcpiTbCopyDsdt (
    272     UINT32                  TableIndex)
    273 {
    274     ACPI_TABLE_HEADER       *NewTable;
    275     ACPI_TABLE_DESC         *TableDesc;
    276 
    277 
    278     TableDesc = &AcpiGbl_RootTableList.Tables[TableIndex];
    279 
    280     NewTable = ACPI_ALLOCATE (TableDesc->Length);
    281     if (!NewTable)
    282     {
    283         ACPI_ERROR ((AE_INFO, "Could not copy DSDT of length 0x%X",
    284             TableDesc->Length));
    285         return (NULL);
    286     }
    287 
    288     memcpy (NewTable, TableDesc->Pointer, TableDesc->Length);
    289     AcpiTbUninstallTable (TableDesc);
    290 
    291     AcpiTbInitTableDescriptor (
    292         &AcpiGbl_RootTableList.Tables[AcpiGbl_DsdtIndex],
    293         ACPI_PTR_TO_PHYSADDR (NewTable),
    294         ACPI_TABLE_ORIGIN_INTERNAL_VIRTUAL, NewTable);
    295 
    296     ACPI_INFO ((
    297         "Forced DSDT copy: length 0x%05X copied locally, original unmapped",
    298         NewTable->Length));
    299 
    300     return (NewTable);
    301 }
    302 
    303 
    304 /*******************************************************************************
    305  *
    306  * FUNCTION:    AcpiTbGetRootTableEntry
    307  *
    308  * PARAMETERS:  TableEntry          - Pointer to the RSDT/XSDT table entry
    309  *              TableEntrySize      - sizeof 32 or 64 (RSDT or XSDT)
    310  *
    311  * RETURN:      Physical address extracted from the root table
    312  *
    313  * DESCRIPTION: Get one root table entry. Handles 32-bit and 64-bit cases on
    314  *              both 32-bit and 64-bit platforms
    315  *
    316  * NOTE:        ACPI_PHYSICAL_ADDRESS is 32-bit on 32-bit platforms, 64-bit on
    317  *              64-bit platforms.
    318  *
    319  ******************************************************************************/
    320 
    321 static ACPI_PHYSICAL_ADDRESS
    322 AcpiTbGetRootTableEntry (
    323     UINT8                   *TableEntry,
    324     UINT32                  TableEntrySize)
    325 {
    326     UINT32                  Address32;
    327     UINT64                  Address64;
    328 
    329 
    330     /*
    331      * Get the table physical address (32-bit for RSDT, 64-bit for XSDT):
    332      * Note: Addresses are 32-bit aligned (not 64) in both RSDT and XSDT
    333      */
    334     if (TableEntrySize == ACPI_RSDT_ENTRY_SIZE)
    335     {
    336         /*
    337          * 32-bit platform, RSDT: Return 32-bit table entry
    338          * 64-bit platform, RSDT: Expand 32-bit to 64-bit and return
    339          */
    340         ACPI_MOVE_32_TO_32(&Address32, TableEntry);
    341         return Address32;
    342     }
    343     else
    344     {
    345         /*
    346          * 32-bit platform, XSDT: Truncate 64-bit to 32-bit and return
    347          * 64-bit platform, XSDT: Move (unaligned) 64-bit to local,
    348          *  return 64-bit
    349          */
    350         ACPI_MOVE_64_TO_64 (&Address64, TableEntry);
    351 
    352 #if ACPI_MACHINE_WIDTH == 32
    353         if (Address64 > ACPI_UINT32_MAX)
    354         {
    355             /* Will truncate 64-bit address to 32 bits, issue warning */
    356 
    357             ACPI_BIOS_WARNING ((AE_INFO,
    358                 "64-bit Physical Address in XSDT is too large (0x%8.8X%8.8X),"
    359                 " truncating",
    360                 ACPI_FORMAT_UINT64 (Address64)));
    361         }
    362 #endif
    363         return ((ACPI_PHYSICAL_ADDRESS) (Address64));
    364     }
    365 }
    366 
    367 
    368 /*******************************************************************************
    369  *
    370  * FUNCTION:    AcpiTbParseRootTable
    371  *
    372  * PARAMETERS:  RsdpAddress         - Pointer to the RSDP
    373  *
    374  * RETURN:      Status
    375  *
    376  * DESCRIPTION: This function is called to parse the Root System Description
    377  *              Table (RSDT or XSDT)
    378  *
    379  * NOTE:        Tables are mapped (not copied) for efficiency. The FACS must
    380  *              be mapped and cannot be copied because it contains the actual
    381  *              memory location of the ACPI Global Lock.
    382  *
    383  ******************************************************************************/
    384 
    385 ACPI_STATUS ACPI_INIT_FUNCTION
    386 AcpiTbParseRootTable (
    387     ACPI_PHYSICAL_ADDRESS   RsdpAddress)
    388 {
    389     ACPI_TABLE_RSDP         *Rsdp;
    390     UINT32                  TableEntrySize;
    391     UINT32                  i;
    392     UINT32                  TableCount;
    393     ACPI_TABLE_HEADER       *Table;
    394     ACPI_PHYSICAL_ADDRESS   Address;
    395     UINT32                  Length;
    396     UINT8                   *TableEntry;
    397     ACPI_STATUS             Status;
    398     UINT32                  TableIndex;
    399 
    400 
    401     ACPI_FUNCTION_TRACE (TbParseRootTable);
    402 
    403 
    404     /* Map the entire RSDP and extract the address of the RSDT or XSDT */
    405 
    406     Rsdp = AcpiOsMapMemory (RsdpAddress, sizeof (ACPI_TABLE_RSDP));
    407     if (!Rsdp)
    408     {
    409         return_ACPI_STATUS (AE_NO_MEMORY);
    410     }
    411 
    412     AcpiTbPrintTableHeader (RsdpAddress,
    413         ACPI_CAST_PTR (ACPI_TABLE_HEADER, Rsdp));
    414 
    415     /* Use XSDT if present and not overridden. Otherwise, use RSDT */
    416 
    417     if ((Rsdp->Revision > 1) &&
    418         Rsdp->XsdtPhysicalAddress &&
    419         !AcpiGbl_DoNotUseXsdt)
    420     {
    421         /*
    422          * RSDP contains an XSDT (64-bit physical addresses). We must use
    423          * the XSDT if the revision is > 1 and the XSDT pointer is present,
    424          * as per the ACPI specification.
    425          */
    426         Address = (ACPI_PHYSICAL_ADDRESS) Rsdp->XsdtPhysicalAddress;
    427         TableEntrySize = ACPI_XSDT_ENTRY_SIZE;
    428     }
    429     else
    430     {
    431         /* Root table is an RSDT (32-bit physical addresses) */
    432 
    433         Address = (ACPI_PHYSICAL_ADDRESS) Rsdp->RsdtPhysicalAddress;
    434         TableEntrySize = ACPI_RSDT_ENTRY_SIZE;
    435     }
    436 
    437     /*
    438      * It is not possible to map more than one entry in some environments,
    439      * so unmap the RSDP here before mapping other tables
    440      */
    441     AcpiOsUnmapMemory (Rsdp, sizeof (ACPI_TABLE_RSDP));
    442 
    443     /* Map the RSDT/XSDT table header to get the full table length */
    444 
    445     Table = AcpiOsMapMemory (Address, sizeof (ACPI_TABLE_HEADER));
    446     if (!Table)
    447     {
    448         return_ACPI_STATUS (AE_NO_MEMORY);
    449     }
    450 
    451     AcpiTbPrintTableHeader (Address, Table);
    452 
    453     /*
    454      * Validate length of the table, and map entire table.
    455      * Minimum length table must contain at least one entry.
    456      */
    457     Length = Table->Length;
    458     AcpiOsUnmapMemory (Table, sizeof (ACPI_TABLE_HEADER));
    459 
    460     if (Length < (sizeof (ACPI_TABLE_HEADER) + TableEntrySize))
    461     {
    462         ACPI_BIOS_ERROR ((AE_INFO,
    463             "Invalid table length 0x%X in RSDT/XSDT", Length));
    464         return_ACPI_STATUS (AE_INVALID_TABLE_LENGTH);
    465     }
    466 
    467     Table = AcpiOsMapMemory (Address, Length);
    468     if (!Table)
    469     {
    470         return_ACPI_STATUS (AE_NO_MEMORY);
    471     }
    472 
    473     /* Validate the root table checksum */
    474 
    475     Status = AcpiUtVerifyChecksum (Table, Length);
    476     if (ACPI_FAILURE (Status))
    477     {
    478         AcpiOsUnmapMemory (Table, Length);
    479         return_ACPI_STATUS (Status);
    480     }
    481 
    482     /* Get the number of entries and pointer to first entry */
    483 
    484     TableCount = (UINT32) ((Table->Length - sizeof (ACPI_TABLE_HEADER)) /
    485         TableEntrySize);
    486     TableEntry = ACPI_ADD_PTR (UINT8, Table, sizeof (ACPI_TABLE_HEADER));
    487 
    488     /* Initialize the root table array from the RSDT/XSDT */
    489 
    490     for (i = 0; i < TableCount; i++)
    491     {
    492         /* Get the table physical address (32-bit for RSDT, 64-bit for XSDT) */
    493 
    494         Address = AcpiTbGetRootTableEntry (TableEntry, TableEntrySize);
    495 
    496         /* Skip NULL entries in RSDT/XSDT */
    497 
    498         if (!Address)
    499         {
    500             goto NextTable;
    501         }
    502 
    503         Status = AcpiTbInstallStandardTable (Address,
    504             ACPI_TABLE_ORIGIN_INTERNAL_PHYSICAL, NULL, FALSE, TRUE,
    505             &TableIndex);
    506 
    507         if (ACPI_SUCCESS (Status) &&
    508             ACPI_COMPARE_NAMESEG (
    509                 &AcpiGbl_RootTableList.Tables[TableIndex].Signature,
    510                 ACPI_SIG_FADT))
    511         {
    512             AcpiGbl_FadtIndex = TableIndex;
    513             AcpiTbParseFadt ();
    514         }
    515 
    516 NextTable:
    517 
    518         TableEntry += TableEntrySize;
    519     }
    520 
    521     AcpiOsUnmapMemory (Table, Length);
    522     return_ACPI_STATUS (AE_OK);
    523 }
    524 
    525 
    526 /*******************************************************************************
    527  *
    528  * FUNCTION:    AcpiTbGetTable
    529  *
    530  * PARAMETERS:  TableDesc           - Table descriptor
    531  *              OutTable            - Where the pointer to the table is returned
    532  *
    533  * RETURN:      Status and pointer to the requested table
    534  *
    535  * DESCRIPTION: Increase a reference to a table descriptor and return the
    536  *              validated table pointer.
    537  *              If the table descriptor is an entry of the root table list,
    538  *              this API must be invoked with ACPI_MTX_TABLES acquired.
    539  *
    540  ******************************************************************************/
    541 
    542 ACPI_STATUS
    543 AcpiTbGetTable (
    544     ACPI_TABLE_DESC        *TableDesc,
    545     ACPI_TABLE_HEADER      **OutTable)
    546 {
    547     ACPI_STATUS            Status;
    548 
    549 
    550     ACPI_FUNCTION_TRACE (AcpiTbGetTable);
    551 
    552 
    553     if (TableDesc->ValidationCount == 0)
    554     {
    555         /* Table need to be "VALIDATED" */
    556 
    557         Status = AcpiTbValidateTable (TableDesc);
    558         if (ACPI_FAILURE (Status))
    559         {
    560             return_ACPI_STATUS (Status);
    561         }
    562     }
    563 
    564     if (TableDesc->ValidationCount < ACPI_MAX_TABLE_VALIDATIONS)
    565     {
    566         TableDesc->ValidationCount++;
    567 
    568         /*
    569          * Detect ValidationCount overflows to ensure that the warning
    570          * message will only be printed once.
    571          */
    572         if (TableDesc->ValidationCount >= ACPI_MAX_TABLE_VALIDATIONS)
    573         {
    574             ACPI_WARNING((AE_INFO,
    575                 "Table %p, Validation count overflows\n", TableDesc));
    576         }
    577     }
    578 
    579     *OutTable = TableDesc->Pointer;
    580     return_ACPI_STATUS (AE_OK);
    581 }
    582 
    583 
    584 /*******************************************************************************
    585  *
    586  * FUNCTION:    AcpiTbPutTable
    587  *
    588  * PARAMETERS:  TableDesc           - Table descriptor
    589  *
    590  * RETURN:      None
    591  *
    592  * DESCRIPTION: Decrease a reference to a table descriptor and release the
    593  *              validated table pointer if no references.
    594  *              If the table descriptor is an entry of the root table list,
    595  *              this API must be invoked with ACPI_MTX_TABLES acquired.
    596  *
    597  ******************************************************************************/
    598 
    599 void
    600 AcpiTbPutTable (
    601     ACPI_TABLE_DESC        *TableDesc)
    602 {
    603 
    604     ACPI_FUNCTION_TRACE (AcpiTbPutTable);
    605 
    606 
    607     if (TableDesc->ValidationCount < ACPI_MAX_TABLE_VALIDATIONS)
    608     {
    609         TableDesc->ValidationCount--;
    610 
    611         /*
    612          * Detect ValidationCount underflows to ensure that the warning
    613          * message will only be printed once.
    614          */
    615         if (TableDesc->ValidationCount >= ACPI_MAX_TABLE_VALIDATIONS)
    616         {
    617             ACPI_WARNING ((AE_INFO,
    618                 "Table %p, Validation count underflows\n", TableDesc));
    619             return_VOID;
    620         }
    621     }
    622 
    623     if (TableDesc->ValidationCount == 0)
    624     {
    625         /* Table need to be "INVALIDATED" */
    626 
    627         AcpiTbInvalidateTable (TableDesc);
    628     }
    629 
    630     return_VOID;
    631 }
    632