FreeBSD/Linux Kernel Cross Reference
sys/contrib/dev/acpica/components/tables/tbxfroot.c

     /******************************************************************************
      *
      * Module Name: tbxfroot - Find the root ACPI table (RSDT)
      *
      *****************************************************************************/
     
     /******************************************************************************
      *
      * 1. Copyright Notice
     *
     * Some or all of this work - Copyright (c) 1999 - 2022, Intel Corp.
     * All rights reserved.
     *
     * 2. License
     *
     * 2.1. This is your license from Intel Corp. under its intellectual property
     * rights. You may have additional license terms from the party that provided
     * you this software, covering your right to use that party's intellectual
     * property rights.
     *
     * 2.2. Intel grants, free of charge, to any person ("Licensee") obtaining a
     * copy of the source code appearing in this file ("Covered Code") an
     * irrevocable, perpetual, worldwide license under Intel's copyrights in the
     * base code distributed originally by Intel ("Original Intel Code") to copy,
     * make derivatives, distribute, use and display any portion of the Covered
     * Code in any form, with the right to sublicense such rights; and
     *
     * 2.3. Intel grants Licensee a non-exclusive and non-transferable patent
     * license (with the right to sublicense), under only those claims of Intel
     * patents that are infringed by the Original Intel Code, to make, use, sell,
     * offer to sell, and import the Covered Code and derivative works thereof
     * solely to the minimum extent necessary to exercise the above copyright
     * license, and in no event shall the patent license extend to any additions
     * to or modifications of the Original Intel Code. No other license or right
     * is granted directly or by implication, estoppel or otherwise;
     *
     * The above copyright and patent license is granted only if the following
     * conditions are met:
     *
     * 3. Conditions
     *
     * 3.1. Redistribution of Source with Rights to Further Distribute Source.
     * Redistribution of source code of any substantial portion of the Covered
     * Code or modification with rights to further distribute source must include
     * the above Copyright Notice, the above License, this list of Conditions,
     * and the following Disclaimer and Export Compliance provision. In addition,
     * Licensee must cause all Covered Code to which Licensee contributes to
     * contain a file documenting the changes Licensee made to create that Covered
     * Code and the date of any change. Licensee must include in that file the
     * documentation of any changes made by any predecessor Licensee. Licensee
     * must include a prominent statement that the modification is derived,
     * directly or indirectly, from Original Intel Code.
     *
     * 3.2. Redistribution of Source with no Rights to Further Distribute Source.
     * Redistribution of source code of any substantial portion of the Covered
     * Code or modification without rights to further distribute source must
     * include the following Disclaimer and Export Compliance provision in the
     * documentation and/or other materials provided with distribution. In
     * addition, Licensee may not authorize further sublicense of source of any
     * portion of the Covered Code, and must include terms to the effect that the
     * license from Licensee to its licensee is limited to the intellectual
     * property embodied in the software Licensee provides to its licensee, and
     * not to intellectual property embodied in modifications its licensee may
     * make.
     *
     * 3.3. Redistribution of Executable. Redistribution in executable form of any
     * substantial portion of the Covered Code or modification must reproduce the
     * above Copyright Notice, and the following Disclaimer and Export Compliance
     * provision in the documentation and/or other materials provided with the
     * distribution.
     *
     * 3.4. Intel retains all right, title, and interest in and to the Original
     * Intel Code.
     *
     * 3.5. Neither the name Intel nor any other trademark owned or controlled by
     * Intel shall be used in advertising or otherwise to promote the sale, use or
     * other dealings in products derived from or relating to the Covered Code
     * without prior written authorization from Intel.
     *
     * 4. Disclaimer and Export Compliance
     *
     * 4.1. INTEL MAKES NO WARRANTY OF ANY KIND REGARDING ANY SOFTWARE PROVIDED
     * HERE. ANY SOFTWARE ORIGINATING FROM INTEL OR DERIVED FROM INTEL SOFTWARE
     * IS PROVIDED "AS IS," AND INTEL WILL NOT PROVIDE ANY SUPPORT, ASSISTANCE,
     * INSTALLATION, TRAINING OR OTHER SERVICES. INTEL WILL NOT PROVIDE ANY
     * UPDATES, ENHANCEMENTS OR EXTENSIONS. INTEL SPECIFICALLY DISCLAIMS ANY
     * IMPLIED WARRANTIES OF MERCHANTABILITY, NONINFRINGEMENT AND FITNESS FOR A
     * PARTICULAR PURPOSE.
     *
     * 4.2. IN NO EVENT SHALL INTEL HAVE ANY LIABILITY TO LICENSEE, ITS LICENSEES
     * OR ANY OTHER THIRD PARTY, FOR ANY LOST PROFITS, LOST DATA, LOSS OF USE OR
     * COSTS OF PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, OR FOR ANY INDIRECT,
     * SPECIAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THIS AGREEMENT, UNDER ANY
     * CAUSE OF ACTION OR THEORY OF LIABILITY, AND IRRESPECTIVE OF WHETHER INTEL
     * HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES. THESE LIMITATIONS
     * SHALL APPLY NOTWITHSTANDING THE FAILURE OF THE ESSENTIAL PURPOSE OF ANY
     * LIMITED REMEDY.
     *
     * 4.3. Licensee shall not export, either directly or indirectly, any of this
    * software or system incorporating such software without first obtaining any
    * required license or other approval from the U. S. Department of Commerce or
    * any other agency or department of the United States Government. In the
    * event Licensee exports any such software from the United States or
    * re-exports any such software from a foreign destination, Licensee shall
    * ensure that the distribution and export/re-export of the software is in
    * compliance with all laws, regulations, orders, or other restrictions of the
    * U.S. Export Administration Regulations. Licensee agrees that neither it nor
    * any of its subsidiaries will export/re-export any technical data, process,
    * software, or service, directly or indirectly, to any country for which the
    * United States government or any agency thereof requires an export license,
    * other governmental approval, or letter of assurance, without first obtaining
    * such license, approval or letter.
    *
    *****************************************************************************
    *
    * Alternatively, you may choose to be licensed under the terms of the
    * following license:
    *
    * Redistribution and use in source and binary forms, with or without
    * modification, are permitted provided that the following conditions
    * are met:
    * 1. Redistributions of source code must retain the above copyright
    *    notice, this list of conditions, and the following disclaimer,
    *    without modification.
    * 2. Redistributions in binary form must reproduce at minimum a disclaimer
    *    substantially similar to the "NO WARRANTY" disclaimer below
    *    ("Disclaimer") and any redistribution must be conditioned upon
    *    including a substantially similar Disclaimer requirement for further
    *    binary redistribution.
    * 3. Neither the names of the above-listed copyright holders nor the names
    *    of any contributors may be used to endorse or promote products derived
    *    from this software without specific prior written permission.
    *
    * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
    *
    * Alternatively, you may choose to be licensed under the terms of the
    * GNU General Public License ("GPL") version 2 as published by the Free
    * Software Foundation.
    *
    *****************************************************************************/
   
   #include <contrib/dev/acpica/include/acpi.h>
   #include <contrib/dev/acpica/include/accommon.h>
   #include <contrib/dev/acpica/include/actables.h>
   
   
   #define _COMPONENT          ACPI_TABLES
           ACPI_MODULE_NAME    ("tbxfroot")
   
   
   /*******************************************************************************
    *
    * FUNCTION:    AcpiTbGetRsdpLength
    *
    * PARAMETERS:  Rsdp                - Pointer to RSDP
    *
    * RETURN:      Table length
    *
    * DESCRIPTION: Get the length of the RSDP
    *
    ******************************************************************************/
   
   UINT32
   AcpiTbGetRsdpLength (
       ACPI_TABLE_RSDP         *Rsdp)
   {
   
       if (!ACPI_VALIDATE_RSDP_SIG (Rsdp->Signature))
       {
           /* BAD Signature */
   
           return (0);
       }
   
       /* "Length" field is available if table version >= 2 */
   
       if (Rsdp->Revision >= 2)
       {
           return (Rsdp->Length);
       }
       else
       {
           return (ACPI_RSDP_CHECKSUM_LENGTH);
       }
   }
   
   
   /*******************************************************************************
    *
    * FUNCTION:    AcpiTbValidateRsdp
    *
    * PARAMETERS:  Rsdp                - Pointer to unvalidated RSDP
    *
    * RETURN:      Status
    *
    * DESCRIPTION: Validate the RSDP (ptr)
    *
    ******************************************************************************/
   
   ACPI_STATUS
   AcpiTbValidateRsdp (
       ACPI_TABLE_RSDP         *Rsdp)
   {
   
       /*
        * The signature and checksum must both be correct
        *
        * Note: Sometimes there exists more than one RSDP in memory; the valid
        * RSDP has a valid checksum, all others have an invalid checksum.
        */
       if (!ACPI_VALIDATE_RSDP_SIG (Rsdp->Signature))
       {
           /* Nope, BAD Signature */
   
           return (AE_BAD_SIGNATURE);
       }
   
       /* Check the standard checksum */
   
       if (AcpiUtChecksum ((UINT8 *) Rsdp, ACPI_RSDP_CHECKSUM_LENGTH) != 0)
       {
           return (AE_BAD_CHECKSUM);
       }
   
       /* Check extended checksum if table version >= 2 */
   
       if ((Rsdp->Revision >= 2) &&
           (AcpiUtChecksum ((UINT8 *) Rsdp, ACPI_RSDP_XCHECKSUM_LENGTH) != 0))
       {
           return (AE_BAD_CHECKSUM);
       }
   
       return (AE_OK);
   }
   
   
   /*******************************************************************************
    *
    * FUNCTION:    AcpiFindRootPointer
    *
    * PARAMETERS:  TableAddress            - Where the table pointer is returned
    *
    * RETURN:      Status, RSDP physical address
    *
    * DESCRIPTION: Search lower 1Mbyte of memory for the root system descriptor
    *              pointer structure. If it is found, set *RSDP to point to it.
    *
    * NOTE1:       The RSDP must be either in the first 1K of the Extended
    *              BIOS Data Area or between E0000 and FFFFF (From ACPI Spec.)
    *              Only a 32-bit physical address is necessary.
    *
    * NOTE2:       This function is always available, regardless of the
    *              initialization state of the rest of ACPI.
    *
    ******************************************************************************/
   
   ACPI_STATUS ACPI_INIT_FUNCTION
   AcpiFindRootPointer (
       ACPI_PHYSICAL_ADDRESS   *TableAddress)
   {
       UINT8                   *TablePtr;
       UINT8                   *MemRover;
       UINT32                  PhysicalAddress;
       UINT32                  EbdaWindowSize;
   
   
       ACPI_FUNCTION_TRACE (AcpiFindRootPointer);
   
   
       /* 1a) Get the location of the Extended BIOS Data Area (EBDA) */
   
       TablePtr = AcpiOsMapMemory (
           (ACPI_PHYSICAL_ADDRESS) ACPI_EBDA_PTR_LOCATION,
           ACPI_EBDA_PTR_LENGTH);
       if (!TablePtr)
       {
           ACPI_ERROR ((AE_INFO,
               "Could not map memory at 0x%8.8X for length %u",
               ACPI_EBDA_PTR_LOCATION, ACPI_EBDA_PTR_LENGTH));
   
           return_ACPI_STATUS (AE_NO_MEMORY);
       }
   
       ACPI_MOVE_16_TO_32 (&PhysicalAddress, TablePtr);
   
       /* Convert segment part to physical address */
   
       PhysicalAddress <<= 4;
       AcpiOsUnmapMemory (TablePtr, ACPI_EBDA_PTR_LENGTH);
   
       /* EBDA present? */
   
       /*
        * Check that the EBDA pointer from memory is sane and does not point
        * above valid low memory
        */
       if (PhysicalAddress > 0x400 &&
           PhysicalAddress < 0xA0000)
       {
           /*
            * Calculate the scan window size
            * The EBDA is not guaranteed to be larger than a KiB and in case
            * that it is smaller, the scanning function would leave the low
            * memory and continue to the VGA range.
            */
           EbdaWindowSize = ACPI_MIN(ACPI_EBDA_WINDOW_SIZE,
               0xA0000 - PhysicalAddress);
   
           /*
            * 1b) Search EBDA paragraphs
            */
           TablePtr = AcpiOsMapMemory (
               (ACPI_PHYSICAL_ADDRESS) PhysicalAddress,
               EbdaWindowSize);
           if (!TablePtr)
           {
               ACPI_ERROR ((AE_INFO,
                   "Could not map memory at 0x%8.8X for length %u",
                   PhysicalAddress, EbdaWindowSize));
   
               return_ACPI_STATUS (AE_NO_MEMORY);
           }
   
           MemRover = AcpiTbScanMemoryForRsdp (
               TablePtr, EbdaWindowSize);
           AcpiOsUnmapMemory (TablePtr, EbdaWindowSize);
   
           if (MemRover)
           {
               /* Return the physical address */
   
               PhysicalAddress +=
                   (UINT32) ACPI_PTR_DIFF (MemRover, TablePtr);
   
               *TableAddress = (ACPI_PHYSICAL_ADDRESS) PhysicalAddress;
               return_ACPI_STATUS (AE_OK);
           }
       }
   
       /*
        * 2) Search upper memory: 16-byte boundaries in E0000h-FFFFFh
        */
       TablePtr = AcpiOsMapMemory (
           (ACPI_PHYSICAL_ADDRESS) ACPI_HI_RSDP_WINDOW_BASE,
           ACPI_HI_RSDP_WINDOW_SIZE);
   
       if (!TablePtr)
       {
           ACPI_ERROR ((AE_INFO,
               "Could not map memory at 0x%8.8X for length %u",
               ACPI_HI_RSDP_WINDOW_BASE, ACPI_HI_RSDP_WINDOW_SIZE));
   
           return_ACPI_STATUS (AE_NO_MEMORY);
       }
   
       MemRover = AcpiTbScanMemoryForRsdp (
           TablePtr, ACPI_HI_RSDP_WINDOW_SIZE);
       AcpiOsUnmapMemory (TablePtr, ACPI_HI_RSDP_WINDOW_SIZE);
   
       if (MemRover)
       {
           /* Return the physical address */
   
           PhysicalAddress = (UINT32)
               (ACPI_HI_RSDP_WINDOW_BASE + ACPI_PTR_DIFF (MemRover, TablePtr));
   
           *TableAddress = (ACPI_PHYSICAL_ADDRESS) PhysicalAddress;
           return_ACPI_STATUS (AE_OK);
       }
   
       /* A valid RSDP was not found */
   
       ACPI_BIOS_ERROR ((AE_INFO, "A valid RSDP was not found"));
       return_ACPI_STATUS (AE_NOT_FOUND);
   }
   
   ACPI_EXPORT_SYMBOL_INIT (AcpiFindRootPointer)
   
   
   /*******************************************************************************
    *
    * FUNCTION:    AcpiTbScanMemoryForRsdp
    *
    * PARAMETERS:  StartAddress        - Starting pointer for search
    *              Length              - Maximum length to search
    *
    * RETURN:      Pointer to the RSDP if found, otherwise NULL.
    *
    * DESCRIPTION: Search a block of memory for the RSDP signature
    *
    ******************************************************************************/
   
   UINT8 *
   AcpiTbScanMemoryForRsdp (
       UINT8                   *StartAddress,
       UINT32                  Length)
   {
       ACPI_STATUS             Status;
       UINT8                   *MemRover;
       UINT8                   *EndAddress;
   
   
       ACPI_FUNCTION_TRACE (TbScanMemoryForRsdp);
   
   
       EndAddress = StartAddress + Length;
   
       /* Search from given start address for the requested length */
   
       for (MemRover = StartAddress; MemRover < EndAddress;
            MemRover += ACPI_RSDP_SCAN_STEP)
       {
           /* The RSDP signature and checksum must both be correct */
   
           Status = AcpiTbValidateRsdp (
               ACPI_CAST_PTR (ACPI_TABLE_RSDP, MemRover));
           if (ACPI_SUCCESS (Status))
           {
               /* Sig and checksum valid, we have found a real RSDP */
   
               ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
                   "RSDP located at physical address %p\n", MemRover));
               return_PTR (MemRover);
           }
   
           /* No sig match or bad checksum, keep searching */
       }
   
       /* Searched entire block, no RSDP was found */
   
       ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
           "Searched entire block from %p, valid RSDP was not found\n",
           StartAddress));
       return_PTR (NULL);
   }

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