freebsd-skq/sys/contrib/dev/acpica/exfldio.c
msmith 4ae46f1754 Patch the reintroduced (~0 << 32) == 1 bug with a cryptic but functional
version.  This should fix the read-before-write problem again.

Obtained from:	"Adam J. Richter" <adam@yggdrasil.com>
2001-02-02 08:31:50 +00:00

862 lines
27 KiB
C

/******************************************************************************
*
* Module Name: amfldio - Aml Field I/O
* $Revision: 37 $
*
*****************************************************************************/
/******************************************************************************
*
* 1. Copyright Notice
*
* Some or all of this work - Copyright (c) 1999, 2000, 2001, 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.
*
*****************************************************************************/
#define __AMFLDIO_C__
#include "acpi.h"
#include "acinterp.h"
#include "amlcode.h"
#include "acnamesp.h"
#include "achware.h"
#include "acevents.h"
#define _COMPONENT INTERPRETER
MODULE_NAME ("amfldio")
/*******************************************************************************
*
* FUNCTION: AcpiAmlReadFieldData
*
* PARAMETERS: *ObjDesc - Field to be read
* *Value - Where to store value
* FieldBitWidth - Field Width in bits (8, 16, or 32)
*
* RETURN: Status
*
* DESCRIPTION: Retrieve the value of the given field
*
******************************************************************************/
ACPI_STATUS
AcpiAmlReadFieldData (
ACPI_OPERAND_OBJECT *ObjDesc,
UINT32 FieldByteOffset,
UINT32 FieldBitWidth,
UINT32 *Value)
{
ACPI_STATUS Status;
ACPI_OPERAND_OBJECT *RgnDesc = NULL;
ACPI_PHYSICAL_ADDRESS Address;
UINT32 LocalValue = 0;
UINT32 FieldByteWidth;
FUNCTION_TRACE ("AmlReadFieldData");
/* ObjDesc is validated by callers */
if (ObjDesc)
{
RgnDesc = ObjDesc->Field.Container;
}
FieldByteWidth = DIV_8 (FieldBitWidth);
Status = AcpiAmlSetupField (ObjDesc, RgnDesc, FieldBitWidth);
if (ACPI_FAILURE (Status))
{
return_ACPI_STATUS (Status);
}
/* SetupField validated RgnDesc and FieldBitWidth */
if (!Value)
{
Value = &LocalValue; /* support reads without saving value */
}
/*
* Set offset to next multiple of field width,
* add region base address and offset within the field
*/
Address = RgnDesc->Region.Address +
(ObjDesc->Field.Offset * FieldByteWidth) +
FieldByteOffset;
DEBUG_PRINT (TRACE_OPREGION,
("AmlReadFieldData: Region %s(%X) at %08lx width %X\n",
AcpiCmGetRegionName (RgnDesc->Region.SpaceId),
RgnDesc->Region.SpaceId, Address,
FieldBitWidth));
/* Invoke the appropriate AddressSpace/OpRegion handler */
Status = AcpiEvAddressSpaceDispatch (RgnDesc, ADDRESS_SPACE_READ,
Address, FieldBitWidth, Value);
if (Status == AE_NOT_IMPLEMENTED)
{
DEBUG_PRINT (ACPI_ERROR,
("AmlReadFieldData: **** Region %s(%X) not implemented\n",
AcpiCmGetRegionName (RgnDesc->Region.SpaceId),
RgnDesc->Region.SpaceId));
}
else if (Status == AE_NOT_EXIST)
{
DEBUG_PRINT (ACPI_ERROR,
("AmlReadFieldData: **** Region %s(%X) has no handler\n",
AcpiCmGetRegionName (RgnDesc->Region.SpaceId),
RgnDesc->Region.SpaceId));
}
DEBUG_PRINT (TRACE_OPREGION,
("AmlReadField: Returned value=%08lx \n", *Value));
return_ACPI_STATUS (Status);
}
/*******************************************************************************
*
* FUNCTION: AcpiAmlReadField
*
* PARAMETERS: *ObjDesc - Field to be read
* *Value - Where to store value
* FieldBitWidth - Field Width in bits (8, 16, or 32)
*
* RETURN: Status
*
* DESCRIPTION: Retrieve the value of the given field
*
******************************************************************************/
ACPI_STATUS
AcpiAmlReadField (
ACPI_OPERAND_OBJECT *ObjDesc,
void *Buffer,
UINT32 BufferLength,
UINT32 ByteLength,
UINT32 DatumLength,
UINT32 BitGranularity,
UINT32 ByteGranularity)
{
ACPI_STATUS Status;
UINT32 ThisFieldByteOffset;
UINT32 ThisFieldDatumOffset;
UINT32 PreviousRawDatum;
UINT32 ThisRawDatum = 0;
UINT32 ValidFieldBits;
UINT32 Mask;
UINT32 MergedDatum = 0;
FUNCTION_TRACE ("AmlReadField");
/*
* Clear the caller's buffer (the whole buffer length as given)
* This is very important, especially in the cases where a byte is read,
* but the buffer is really a UINT32 (4 bytes).
*/
MEMSET (Buffer, 0, BufferLength);
/* Read the first raw datum to prime the loop */
ThisFieldByteOffset = 0;
ThisFieldDatumOffset= 0;
Status = AcpiAmlReadFieldData (ObjDesc, ThisFieldByteOffset, BitGranularity,
&PreviousRawDatum);
if (ACPI_FAILURE (Status))
{
goto Cleanup;
}
/* We might actually be done if the request fits in one datum */
if ((DatumLength == 1) &&
((ObjDesc->Field.BitOffset + ObjDesc->FieldUnit.Length) <=
(UINT16) BitGranularity))
{
MergedDatum = PreviousRawDatum;
MergedDatum = (MergedDatum >> ObjDesc->Field.BitOffset);
ValidFieldBits = ObjDesc->FieldUnit.Length % BitGranularity;
if (ValidFieldBits)
{
Mask = (((UINT32) 1 << ValidFieldBits) - (UINT32) 1);
MergedDatum &= Mask;
}
/*
* Place the MergedDatum into the proper format and return buffer
* field
*/
switch (ByteGranularity)
{
case 1:
((UINT8 *) Buffer) [ThisFieldDatumOffset] = (UINT8) MergedDatum;
break;
case 2:
MOVE_UNALIGNED16_TO_16 (&(((UINT16 *) Buffer)[ThisFieldDatumOffset]), &MergedDatum);
break;
case 4:
MOVE_UNALIGNED32_TO_32 (&(((UINT32 *) Buffer)[ThisFieldDatumOffset]), &MergedDatum);
break;
}
ThisFieldByteOffset = 1;
ThisFieldDatumOffset = 1;
}
else
{
/* We need to get more raw data to complete one or more field data */
while (ThisFieldDatumOffset < DatumLength)
{
/*
* If the field is aligned on a byte boundary, we don't want
* to perform a final read, since this would potentially read
* past the end of the region.
*
* TBD: [Investigate] It may make more sense to just split the aligned
* and non-aligned cases since the aligned case is so very simple,
*/
if ((ObjDesc->Field.BitOffset != 0) ||
((ObjDesc->Field.BitOffset == 0) &&
(ThisFieldDatumOffset < (DatumLength -1))))
{
/*
* Get the next raw datum, it contains some or all bits
* of the current field datum
*/
Status = AcpiAmlReadFieldData (ObjDesc,
ThisFieldByteOffset + ByteGranularity,
BitGranularity, &ThisRawDatum);
if (ACPI_FAILURE (Status))
{
goto Cleanup;
}
/* Before merging the data, make sure the unused bits are clear */
switch (ByteGranularity)
{
case 1:
ThisRawDatum &= 0x000000FF;
PreviousRawDatum &= 0x000000FF;
break;
case 2:
ThisRawDatum &= 0x0000FFFF;
PreviousRawDatum &= 0x0000FFFF;
break;
}
}
/*
* Put together bits of the two raw data to make a complete
* field datum
*/
if (ObjDesc->Field.BitOffset != 0)
{
MergedDatum =
(PreviousRawDatum >> ObjDesc->Field.BitOffset) |
(ThisRawDatum << (BitGranularity - ObjDesc->Field.BitOffset));
}
else
{
MergedDatum = PreviousRawDatum;
}
/*
* Prepare the merged datum for storing into the caller's
* buffer. It is possible to have a 32-bit buffer
* (ByteGranularity == 4), but a ObjDesc->Field.Length
* of 8 or 16, meaning that the upper bytes of merged data
* are undesired. This section fixes that.
*/
switch (ObjDesc->Field.Length)
{
case 8:
MergedDatum &= 0x000000FF;
break;
case 16:
MergedDatum &= 0x0000FFFF;
break;
}
/*
* Now store the datum in the caller's buffer, according to
* the data type
*/
switch (ByteGranularity)
{
case 1:
((UINT8 *) Buffer) [ThisFieldDatumOffset] = (UINT8) MergedDatum;
break;
case 2:
MOVE_UNALIGNED16_TO_16 (&(((UINT16 *) Buffer) [ThisFieldDatumOffset]), &MergedDatum);
break;
case 4:
MOVE_UNALIGNED32_TO_32 (&(((UINT32 *) Buffer) [ThisFieldDatumOffset]), &MergedDatum);
break;
}
/*
* Save the most recent datum since it contains bits of
* the *next* field datum
*/
PreviousRawDatum = ThisRawDatum;
ThisFieldByteOffset += ByteGranularity;
ThisFieldDatumOffset++;
} /* while */
}
Cleanup:
return_ACPI_STATUS (Status);
}
/*******************************************************************************
*
* FUNCTION: AcpiAmlWriteFieldData
*
* PARAMETERS: *ObjDesc - Field to be set
* Value - Value to store
* FieldBitWidth - Field Width in bits (8, 16, or 32)
*
* RETURN: Status
*
* DESCRIPTION: Store the value into the given field
*
******************************************************************************/
static ACPI_STATUS
AcpiAmlWriteFieldData (
ACPI_OPERAND_OBJECT *ObjDesc,
UINT32 FieldByteOffset,
UINT32 FieldBitWidth,
UINT32 Value)
{
ACPI_STATUS Status = AE_OK;
ACPI_OPERAND_OBJECT *RgnDesc = NULL;
ACPI_PHYSICAL_ADDRESS Address;
UINT32 FieldByteWidth;
FUNCTION_TRACE ("AmlWriteFieldData");
/* ObjDesc is validated by callers */
if (ObjDesc)
{
RgnDesc = ObjDesc->Field.Container;
}
FieldByteWidth = DIV_8 (FieldBitWidth);
Status = AcpiAmlSetupField (ObjDesc, RgnDesc, FieldBitWidth);
if (ACPI_FAILURE (Status))
{
return_ACPI_STATUS (Status);
}
/*
* Set offset to next multiple of field width,
* add region base address and offset within the field
*/
Address = RgnDesc->Region.Address +
(ObjDesc->Field.Offset * FieldByteWidth) +
FieldByteOffset;
DEBUG_PRINT (TRACE_OPREGION,
("AmlWriteField: Store %lx in Region %s(%X) at %p width %X\n",
Value, AcpiCmGetRegionName (RgnDesc->Region.SpaceId),
RgnDesc->Region.SpaceId, Address,
FieldBitWidth));
/* Invoke the appropriate AddressSpace/OpRegion handler */
Status = AcpiEvAddressSpaceDispatch (RgnDesc, ADDRESS_SPACE_WRITE,
Address, FieldBitWidth, &Value);
if (Status == AE_NOT_IMPLEMENTED)
{
DEBUG_PRINT (ACPI_ERROR,
("AmlWriteField: **** Region type %s(%X) not implemented\n",
AcpiCmGetRegionName (RgnDesc->Region.SpaceId),
RgnDesc->Region.SpaceId));
}
else if (Status == AE_NOT_EXIST)
{
DEBUG_PRINT (ACPI_ERROR,
("AmlWriteField: **** Region type %s(%X) does not have a handler\n",
AcpiCmGetRegionName (RgnDesc->Region.SpaceId),
RgnDesc->Region.SpaceId));
}
return_ACPI_STATUS (Status);
}
/*****************************************************************************
*
* FUNCTION: AcpiAmlWriteFieldDataWithUpdateRule
*
* PARAMETERS: *ObjDesc - Field to be set
* Value - Value to store
* FieldBitWidth - Field Width in bits (8, 16, or 32)
*
* RETURN: Status
*
* DESCRIPTION: Apply the field update rule to a field write
*
****************************************************************************/
static ACPI_STATUS
AcpiAmlWriteFieldDataWithUpdateRule (
ACPI_OPERAND_OBJECT *ObjDesc,
UINT32 Mask,
UINT32 FieldValue,
UINT32 ThisFieldByteOffset,
UINT32 BitGranularity)
{
ACPI_STATUS Status = AE_OK;
UINT32 MergedValue;
UINT32 CurrentValue;
/* Start with the new bits */
MergedValue = FieldValue;
/* Decode the update rule */
switch (ObjDesc->Field.UpdateRule)
{
case 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 << (sizeof(Mask) * 8 - BitGranularity)) != 0)
{
/*
* Read the current contents of the byte/word/dword containing
* the field, and merge with the new field value.
*/
Status = AcpiAmlReadFieldData (ObjDesc, ThisFieldByteOffset,
BitGranularity, &CurrentValue);
MergedValue |= (CurrentValue & ~Mask);
}
break;
case UPDATE_WRITE_AS_ONES:
/* Set positions outside the field to all ones */
MergedValue |= ~Mask;
break;
case UPDATE_WRITE_AS_ZEROS:
/* Set positions outside the field to all zeros */
MergedValue &= Mask;
break;
default:
DEBUG_PRINT (ACPI_ERROR,
("WriteFieldDataWithUpdateRule: Unknown UpdateRule setting: %x\n",
ObjDesc->Field.UpdateRule));
Status = AE_AML_OPERAND_VALUE;
}
/* Write the merged value */
if (ACPI_SUCCESS (Status))
{
Status = AcpiAmlWriteFieldData (ObjDesc, ThisFieldByteOffset,
BitGranularity, MergedValue);
}
return (Status);
}
/*****************************************************************************
*
* FUNCTION: AcpiAmlWriteField
*
* PARAMETERS: *ObjDesc - Field to be set
* Value - Value to store
* FieldBitWidth - Field Width in bits (8, 16, or 32)
*
* RETURN: Status
*
* DESCRIPTION: Store the value into the given field
*
****************************************************************************/
ACPI_STATUS
AcpiAmlWriteField (
ACPI_OPERAND_OBJECT *ObjDesc,
void *Buffer,
UINT32 BufferLength,
UINT32 ByteLength,
UINT32 DatumLength,
UINT32 BitGranularity,
UINT32 ByteGranularity)
{
ACPI_STATUS Status;
UINT32 ThisFieldByteOffset;
UINT32 ThisFieldDatumOffset;
UINT32 Mask;
UINT32 MergedDatum;
UINT32 PreviousRawDatum;
UINT32 ThisRawDatum;
UINT32 FieldValue;
UINT32 ValidFieldBits;
FUNCTION_TRACE ("AmlWriteField");
/*
* Break the request into up to three parts:
* non-aligned part at start, aligned part in middle, non-aligned part
* at end --- Just like an I/O request ---
*/
ThisFieldByteOffset = 0;
ThisFieldDatumOffset= 0;
/* Get a datum */
switch (ByteGranularity)
{
case 1:
PreviousRawDatum = ((UINT8 *) Buffer) [ThisFieldDatumOffset];
break;
case 2:
MOVE_UNALIGNED16_TO_32 (&PreviousRawDatum, &(((UINT16 *) Buffer) [ThisFieldDatumOffset]));
break;
case 4:
MOVE_UNALIGNED32_TO_32 (&PreviousRawDatum, &(((UINT32 *) Buffer) [ThisFieldDatumOffset]));
break;
default:
DEBUG_PRINT (ACPI_ERROR, ("AmlWriteField: Invalid granularity: %x\n",
ByteGranularity));
Status = AE_AML_OPERAND_VALUE;
goto Cleanup;
}
/*
* Write a partial field datum if field does not begin on a datum boundary
*
* Construct Mask with 1 bits where the field is, 0 bits elsewhere
*
* 1) Bits above the field
*/
Mask = (((UINT32)(-1)) << (UINT32)ObjDesc->Field.BitOffset);
/* 2) Only the bottom 5 bits are valid for a shift operation. */
if ((ObjDesc->Field.BitOffset + ObjDesc->FieldUnit.Length) < 32)
{
/* Bits above the field */
Mask &= (~(((UINT32)(-1)) << ((UINT32)ObjDesc->Field.BitOffset +
(UINT32)ObjDesc->FieldUnit.Length)));
}
/* 3) Shift and mask the value into the field position */
FieldValue = (PreviousRawDatum << ObjDesc->Field.BitOffset) & Mask;
Status = AcpiAmlWriteFieldDataWithUpdateRule (ObjDesc, Mask, FieldValue,
ThisFieldByteOffset,
BitGranularity);
if (ACPI_FAILURE (Status))
{
goto Cleanup;
}
/* If the field fits within one datum, we are done. */
if ((DatumLength == 1) &&
((ObjDesc->Field.BitOffset + ObjDesc->FieldUnit.Length) <=
(UINT16) BitGranularity))
{
goto Cleanup;
}
/*
* We don't need to worry about the update rule for these data, because
* all of the bits are part of the field.
*
* Can't write the last datum, however, because it might contain bits that
* are not part of the field -- the update rule must be applied.
*/
while (ThisFieldDatumOffset < (DatumLength - 1))
{
ThisFieldDatumOffset++;
/* Get the next raw datum, it contains bits of the current field datum... */
switch (ByteGranularity)
{
case 1:
ThisRawDatum = ((UINT8 *) Buffer) [ThisFieldDatumOffset];
break;
case 2:
MOVE_UNALIGNED16_TO_32 (&ThisRawDatum, &(((UINT16 *) Buffer) [ThisFieldDatumOffset]));
break;
case 4:
MOVE_UNALIGNED32_TO_32 (&ThisRawDatum, &(((UINT32 *) Buffer) [ThisFieldDatumOffset]));
break;
default:
DEBUG_PRINT (ACPI_ERROR, ("AmlWriteField: Invalid Byte Granularity: %x\n",
ByteGranularity));
Status = AE_AML_OPERAND_VALUE;
goto Cleanup;
}
/*
* Put together bits of the two raw data to make a complete field
* datum
*/
if (ObjDesc->Field.BitOffset != 0)
{
MergedDatum =
(PreviousRawDatum >> (BitGranularity - ObjDesc->Field.BitOffset)) |
(ThisRawDatum << ObjDesc->Field.BitOffset);
}
else
{
MergedDatum = ThisRawDatum;
}
/* Now write the completed datum */
Status = AcpiAmlWriteFieldData (ObjDesc,
ThisFieldByteOffset + ByteGranularity,
BitGranularity, MergedDatum);
if (ACPI_FAILURE (Status))
{
goto Cleanup;
}
/*
* Save the most recent datum since it contains bits of
* the *next* field datum
*/
PreviousRawDatum = ThisRawDatum;
ThisFieldByteOffset += ByteGranularity;
} /* while */
/* Write a partial field datum if field does not end on a datum boundary */
if ((ObjDesc->FieldUnit.Length + ObjDesc->FieldUnit.BitOffset) %
BitGranularity)
{
switch (ByteGranularity)
{
case 1:
ThisRawDatum = ((UINT8 *) Buffer) [ThisFieldDatumOffset];
break;
case 2:
MOVE_UNALIGNED16_TO_32 (&ThisRawDatum, &(((UINT16 *) Buffer) [ThisFieldDatumOffset]));
break;
case 4:
MOVE_UNALIGNED32_TO_32 (&ThisRawDatum, &(((UINT32 *) Buffer) [ThisFieldDatumOffset]));
break;
}
/* Construct Mask with 1 bits where the field is, 0 bits elsewhere */
ValidFieldBits = ((ObjDesc->FieldUnit.Length % BitGranularity) +
ObjDesc->Field.BitOffset);
Mask = (((UINT32) 1 << ValidFieldBits) - (UINT32) 1);
/* Shift and mask the value into the field position */
FieldValue = (PreviousRawDatum >>
(BitGranularity - ObjDesc->Field.BitOffset)) & Mask;
Status = AcpiAmlWriteFieldDataWithUpdateRule (ObjDesc, Mask, FieldValue,
ThisFieldByteOffset + ByteGranularity,
BitGranularity);
if (ACPI_FAILURE (Status))
{
goto Cleanup;
}
}
Cleanup:
return_ACPI_STATUS (Status);
}