exfldio.c

acpi tools for linux include acpiexec and acpixtract

        AcpiUtGetRegionName (RgnDesc->Region.SpaceId),
        RgnDesc->Region.SpaceId,
        ObjDesc->CommonField.AccessByteWidth,
        ObjDesc->CommonField.BaseByteOffset,
        FieldDatumByteOffset,
        ACPI_CAST_PTR (void, Address)));

    /* Invoke the appropriate AddressSpace/OpRegion handler */

    Status = AcpiEvAddressSpaceDispatch (RgnDesc, Function,
                Address,
                ACPI_MUL_8 (ObjDesc->CommonField.AccessByteWidth), Value);

    if (ACPI_FAILURE (Status))
    {
        if (Status == AE_NOT_IMPLEMENTED)
        {
            ACPI_ERROR ((AE_INFO,
                "Region %s(%X) not implemented",
                AcpiUtGetRegionName (RgnDesc->Region.SpaceId),
                RgnDesc->Region.SpaceId));
        }
        else if (Status == AE_NOT_EXIST)
        {
            ACPI_ERROR ((AE_INFO,
                "Region %s(%X) has no handler",
                AcpiUtGetRegionName (RgnDesc->Region.SpaceId),
                RgnDesc->Region.SpaceId));
        }
    }

    return_ACPI_STATUS (Status);
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiExRegisterOverflow
 *
 * PARAMETERS:  ObjDesc                 - Register(Field) to be written
 *              Value                   - Value to be stored
 *
 * RETURN:      TRUE if value overflows the field, FALSE otherwise
 *
 * DESCRIPTION: Check if a value is out of range of the field being written.
 *              Used to check if the values written to Index and Bank registers
 *              are out of range.  Normally, the value is simply truncated
 *              to fit the field, but this case is most likely a serious
 *              coding error in the ASL.
 *
 ******************************************************************************/

static BOOLEAN
AcpiExRegisterOverflow (
    ACPI_OPERAND_OBJECT     *ObjDesc,
    ACPI_INTEGER            Value)
{

    if (ObjDesc->CommonField.BitLength >= ACPI_INTEGER_BIT_SIZE)
    {
        /*
         * The field is large enough to hold the maximum integer, so we can
         * never overflow it.
         */
        return (FALSE);
    }

    if (Value >= ((ACPI_INTEGER) 1 << ObjDesc->CommonField.BitLength))
    {
        /*
         * The Value is larger than the maximum value that can fit into
         * the register.
         */
        return (TRUE);
    }

    /* The Value will fit into the field with no truncation */

    return (FALSE);
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiExFieldDatumIo
 *
 * PARAMETERS:  ObjDesc                 - Field to be read
 *              FieldDatumByteOffset    - Byte offset of this datum within the
 *                                        parent field
 *              Value                   - Where to store value (must be 64 bits)
 *              ReadWrite               - Read or Write flag
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Read or Write a single datum of a field.  The FieldType is
 *              demultiplexed here to handle the different types of fields
 *              (BufferField, RegionField, IndexField, BankField)
 *
 ******************************************************************************/

static ACPI_STATUS
AcpiExFieldDatumIo (
    ACPI_OPERAND_OBJECT     *ObjDesc,
    UINT32                  FieldDatumByteOffset,
    ACPI_INTEGER            *Value,
    UINT32                  ReadWrite)
{
    ACPI_STATUS             Status;
    ACPI_INTEGER            LocalValue;


    ACPI_FUNCTION_TRACE_U32 (ExFieldDatumIo, FieldDatumByteOffset);


    if (ReadWrite == ACPI_READ)
    {
        if (!Value)
        {
            LocalValue = 0;

            /* To support reads without saving return value */
            Value = &LocalValue;
        }

        /* Clear the entire return buffer first, [Very Important!] */

        *Value = 0;
    }

    /*
     * The four types of fields are:
     *
     * BufferField - Read/write from/to a Buffer
     * RegionField - Read/write from/to a Operation Region.
     * BankField   - Write to a Bank Register, then read/write from/to an
     *               OperationRegion
     * IndexField  - Write to an Index Register, then read/write from/to a
     *               Data Register
     */
    switch (ACPI_GET_OBJECT_TYPE (ObjDesc))
    {
    case ACPI_TYPE_BUFFER_FIELD:
        /*
         * If the BufferField arguments have not been previously evaluated,
         * evaluate them now and save the results.
         */
        if (!(ObjDesc->Common.Flags & AOPOBJ_DATA_VALID))
        {
            Status = AcpiDsGetBufferFieldArguments (ObjDesc);
            if (ACPI_FAILURE (Status))
            {
                return_ACPI_STATUS (Status);
            }
        }

        if (ReadWrite == ACPI_READ)
        {
            /*
             * Copy the data from the source buffer.
             * Length is the field width in bytes.
             */
            ACPI_MEMCPY (Value,
                (ObjDesc->BufferField.BufferObj)->Buffer.Pointer +
                    ObjDesc->BufferField.BaseByteOffset +
                    FieldDatumByteOffset,
                ObjDesc->CommonField.AccessByteWidth);
        }
        else
        {
            /*
             * Copy the data to the target buffer.
             * Length is the field width in bytes.
             */
            ACPI_MEMCPY ((ObjDesc->BufferField.BufferObj)->Buffer.Pointer +
                ObjDesc->BufferField.BaseByteOffset +
                FieldDatumByteOffset,
                Value, ObjDesc->CommonField.AccessByteWidth);
        }

        Status = AE_OK;
        break;


    case ACPI_TYPE_LOCAL_BANK_FIELD:

        /*
         * Ensure that the BankValue is not beyond the capacity of
         * the register
         */
        if (AcpiExRegisterOverflow (ObjDesc->BankField.BankObj,
                (ACPI_INTEGER) ObjDesc->BankField.Value))
        {
            return_ACPI_STATUS (AE_AML_REGISTER_LIMIT);
        }

        /*
         * For BankFields, we must write the BankValue to the BankRegister
         * (itself a RegionField) before we can access the data.
         */
        Status = AcpiExInsertIntoField (ObjDesc->BankField.BankObj,
                    &ObjDesc->BankField.Value,
                    sizeof (ObjDesc->BankField.Value));
        if (ACPI_FAILURE (Status))
        {
            return_ACPI_STATUS (Status);
        }

        /*
         * Now that the Bank has been selected, fall through to the
         * RegionField case and write the datum to the Operation Region
         */

        /*lint -fallthrough */


    case ACPI_TYPE_LOCAL_REGION_FIELD:
        /*
         * For simple RegionFields, we just directly access the owning
         * Operation Region.
         */
        Status = AcpiExAccessRegion (ObjDesc, FieldDatumByteOffset, Value,
                    ReadWrite);
        break;


    case ACPI_TYPE_LOCAL_INDEX_FIELD:


        /*
         * Ensure that the IndexValue is not beyond the capacity of
         * the register
         */
        if (AcpiExRegisterOverflow (ObjDesc->IndexField.IndexObj,
                (ACPI_INTEGER) ObjDesc->IndexField.Value))
        {
            return_ACPI_STATUS (AE_AML_REGISTER_LIMIT);
        }

        /* Write the index value to the IndexRegister (itself a RegionField) */

        FieldDatumByteOffset += ObjDesc->IndexField.Value;

        ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
            "Write to Index Register: Value %8.8X\n",
            FieldDatumByteOffset));

        Status = AcpiExInsertIntoField (ObjDesc->IndexField.IndexObj,
                    &FieldDatumByteOffset,
                    sizeof (FieldDatumByteOffset));
        if (ACPI_FAILURE (Status))
        {
            return_ACPI_STATUS (Status);
        }

        ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
            "I/O to Data Register: ValuePtr %p\n", Value));

        if (ReadWrite == ACPI_READ)
        {
            /* Read the datum from the DataRegister */

            Status = AcpiExExtractFromField (ObjDesc->IndexField.DataObj,
                        Value, sizeof (ACPI_INTEGER));
        }
        else
        {
            /* Write the datum to the DataRegister */

            Status = AcpiExInsertIntoField (ObjDesc->IndexField.DataObj,
                        Value, sizeof (ACPI_INTEGER));
        }
        break;


    default:

        ACPI_ERROR ((AE_INFO, "Wrong object type in field I/O %X",
            ACPI_GET_OBJECT_TYPE (ObjDesc)));
        Status = AE_AML_INTERNAL;
        break;
    }

    if (ACPI_SUCCESS (Status))
    {
        if (ReadWrite == ACPI_READ)
        {
            ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
                "Value Read %8.8X%8.8X, Width %d\n",
                ACPI_FORMAT_UINT64 (*Value),
                ObjDesc->CommonField.AccessByteWidth));
        }
        else
        {
            ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
                "Value Written %8.8X%8.8X, Width %d\n",
                ACPI_FORMAT_UINT64 (*Value),
                ObjDesc->CommonField.AccessByteWidth));
        }
    }

    return_ACPI_STATUS (Status);
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiExWriteWithUpdateRule
 *
 * PARAMETERS:  ObjDesc                 - Field to be written
 *              Mask                    - bitmask within field datum
 *              FieldValue              - Value to write
 *              FieldDatumByteOffset    - Offset of datum within field
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Apply the field update rule to a field write
 *
 ******************************************************************************/

ACPI_STATUS
AcpiExWriteWithUpdateRule (
    ACPI_OPERAND_OBJECT     *ObjDesc,
    ACPI_INTEGER            Mask,
    ACPI_INTEGER            FieldValue,
    UINT32                  FieldDatumByteOffset)
{
    ACPI_STATUS             Status = AE_OK;
    ACPI_INTEGER            MergedValue;
    ACPI_INTEGER            CurrentValue;


    ACPI_FUNCTION_TRACE_U32 (ExWriteWithUpdateRule, Mask);


    /* Start with the new bits  */

    MergedValue = FieldValue;

    /* If the mask is all ones, we don't need to worry about the update rule */

    if (Mask != ACPI_INTEGER_MAX)
    {
        /* Decode the update rule */

        switch (ObjDesc->CommonField.FieldFlags & AML_FIELD_UPDATE_RULE_MASK)
        {
        case AML_FIELD_UPDATE_PRESERVE:
            /*
             * Check if update rule needs to be applied (not if mask is all
             * ones)  The left shift drops the bits we want to ignore.
             */
            if ((~Mask << (ACPI_MUL_8 (sizeof (Mask)) -
                           ACPI_MUL_8 (ObjDesc->CommonField.AccessByteWidth))) != 0)
            {
                /*
                 * Read the current contents of the byte/word/dword containing
                 * the field, and merge with the new field value.
                 */
                Status = AcpiExFieldDatumIo (ObjDesc, FieldDatumByteOffset,
                            &CurrentValue, ACPI_READ);
                if (ACPI_FAILURE (Status))
                {