minix3/drivers/power/acpi/executer/exfldio.c

1082 lines
35 KiB
C

/******************************************************************************
*
* Module Name: exfldio - Aml Field I/O
*
*****************************************************************************/
/******************************************************************************
*
* 1. Copyright Notice
*
* Some or all of this work - Copyright (c) 1999 - 2010, 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 __EXFLDIO_C__
#include "acpi.h"
#include "accommon.h"
#include "acinterp.h"
#include "amlcode.h"
#include "acevents.h"
#include "acdispat.h"
#define _COMPONENT ACPI_EXECUTER
ACPI_MODULE_NAME ("exfldio")
/* Local prototypes */
static ACPI_STATUS
AcpiExFieldDatumIo (
ACPI_OPERAND_OBJECT *ObjDesc,
UINT32 FieldDatumByteOffset,
UINT64 *Value,
UINT32 ReadWrite);
static BOOLEAN
AcpiExRegisterOverflow (
ACPI_OPERAND_OBJECT *ObjDesc,
UINT64 Value);
static ACPI_STATUS
AcpiExSetupRegion (
ACPI_OPERAND_OBJECT *ObjDesc,
UINT32 FieldDatumByteOffset);
/*******************************************************************************
*
* FUNCTION: AcpiExSetupRegion
*
* PARAMETERS: ObjDesc - Field to be read or written
* FieldDatumByteOffset - Byte offset of this datum within the
* parent field
*
* RETURN: Status
*
* DESCRIPTION: Common processing for AcpiExExtractFromField and
* AcpiExInsertIntoField. Initialize the Region if necessary and
* validate the request.
*
******************************************************************************/
static ACPI_STATUS
AcpiExSetupRegion (
ACPI_OPERAND_OBJECT *ObjDesc,
UINT32 FieldDatumByteOffset)
{
ACPI_STATUS Status = AE_OK;
ACPI_OPERAND_OBJECT *RgnDesc;
ACPI_FUNCTION_TRACE_U32 (ExSetupRegion, FieldDatumByteOffset);
RgnDesc = ObjDesc->CommonField.RegionObj;
/* We must have a valid region */
if (RgnDesc->Common.Type != ACPI_TYPE_REGION)
{
ACPI_ERROR ((AE_INFO, "Needed Region, found type 0x%X (%s)",
RgnDesc->Common.Type,
AcpiUtGetObjectTypeName (RgnDesc)));
return_ACPI_STATUS (AE_AML_OPERAND_TYPE);
}
/*
* If the Region Address and Length have not been previously evaluated,
* evaluate them now and save the results.
*/
if (!(RgnDesc->Common.Flags & AOPOBJ_DATA_VALID))
{
Status = AcpiDsGetRegionArguments (RgnDesc);
if (ACPI_FAILURE (Status))
{
return_ACPI_STATUS (Status);
}
}
/*
* Exit now for SMBus or IPMI address space, it has a non-linear address space
* and the request cannot be directly validated
*/
if (RgnDesc->Region.SpaceId == ACPI_ADR_SPACE_SMBUS ||
RgnDesc->Region.SpaceId == ACPI_ADR_SPACE_IPMI)
{
/* SMBus or IPMI has a non-linear address space */
return_ACPI_STATUS (AE_OK);
}
#ifdef ACPI_UNDER_DEVELOPMENT
/*
* If the Field access is AnyAcc, we can now compute the optimal
* access (because we know know the length of the parent region)
*/
if (!(ObjDesc->Common.Flags & AOPOBJ_DATA_VALID))
{
if (ACPI_FAILURE (Status))
{
return_ACPI_STATUS (Status);
}
}
#endif
/*
* Validate the request. The entire request from the byte offset for a
* length of one field datum (access width) must fit within the region.
* (Region length is specified in bytes)
*/
if (RgnDesc->Region.Length <
(ObjDesc->CommonField.BaseByteOffset +
FieldDatumByteOffset +
ObjDesc->CommonField.AccessByteWidth))
{
if (AcpiGbl_EnableInterpreterSlack)
{
/*
* Slack mode only: We will go ahead and allow access to this
* field if it is within the region length rounded up to the next
* access width boundary. ACPI_SIZE cast for 64-bit compile.
*/
if (ACPI_ROUND_UP (RgnDesc->Region.Length,
ObjDesc->CommonField.AccessByteWidth) >=
((ACPI_SIZE) ObjDesc->CommonField.BaseByteOffset +
ObjDesc->CommonField.AccessByteWidth +
FieldDatumByteOffset))
{
return_ACPI_STATUS (AE_OK);
}
}
if (RgnDesc->Region.Length < ObjDesc->CommonField.AccessByteWidth)
{
/*
* This is the case where the AccessType (AccWord, etc.) is wider
* than the region itself. For example, a region of length one
* byte, and a field with Dword access specified.
*/
ACPI_ERROR ((AE_INFO,
"Field [%4.4s] access width (%u bytes) too large for region [%4.4s] (length %u)",
AcpiUtGetNodeName (ObjDesc->CommonField.Node),
ObjDesc->CommonField.AccessByteWidth,
AcpiUtGetNodeName (RgnDesc->Region.Node),
RgnDesc->Region.Length));
}
/*
* Offset rounded up to next multiple of field width
* exceeds region length, indicate an error
*/
ACPI_ERROR ((AE_INFO,
"Field [%4.4s] Base+Offset+Width %u+%u+%u is beyond end of region [%4.4s] (length %u)",
AcpiUtGetNodeName (ObjDesc->CommonField.Node),
ObjDesc->CommonField.BaseByteOffset,
FieldDatumByteOffset, ObjDesc->CommonField.AccessByteWidth,
AcpiUtGetNodeName (RgnDesc->Region.Node),
RgnDesc->Region.Length));
return_ACPI_STATUS (AE_AML_REGION_LIMIT);
}
return_ACPI_STATUS (AE_OK);
}
/*******************************************************************************
*
* FUNCTION: AcpiExAccessRegion
*
* PARAMETERS: ObjDesc - Field to be read
* FieldDatumByteOffset - Byte offset of this datum within the
* parent field
* Value - Where to store value (must at least
* 64 bits)
* Function - Read or Write flag plus other region-
* dependent flags
*
* RETURN: Status
*
* DESCRIPTION: Read or Write a single field datum to an Operation Region.
*
******************************************************************************/
ACPI_STATUS
AcpiExAccessRegion (
ACPI_OPERAND_OBJECT *ObjDesc,
UINT32 FieldDatumByteOffset,
UINT64 *Value,
UINT32 Function)
{
ACPI_STATUS Status;
ACPI_OPERAND_OBJECT *RgnDesc;
UINT32 RegionOffset;
ACPI_FUNCTION_TRACE (ExAccessRegion);
/*
* Ensure that the region operands are fully evaluated and verify
* the validity of the request
*/
Status = AcpiExSetupRegion (ObjDesc, FieldDatumByteOffset);
if (ACPI_FAILURE (Status))
{
return_ACPI_STATUS (Status);
}
/*
* The physical address of this field datum is:
*
* 1) The base of the region, plus
* 2) The base offset of the field, plus
* 3) The current offset into the field
*/
RgnDesc = ObjDesc->CommonField.RegionObj;
RegionOffset =
ObjDesc->CommonField.BaseByteOffset +
FieldDatumByteOffset;
if ((Function & ACPI_IO_MASK) == ACPI_READ)
{
ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD, "[READ]"));
}
else
{
ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD, "[WRITE]"));
}
ACPI_DEBUG_PRINT_RAW ((ACPI_DB_BFIELD,
" Region [%s:%X], Width %X, ByteBase %X, Offset %X at %p\n",
AcpiUtGetRegionName (RgnDesc->Region.SpaceId),
RgnDesc->Region.SpaceId,
ObjDesc->CommonField.AccessByteWidth,
ObjDesc->CommonField.BaseByteOffset,
FieldDatumByteOffset,
ACPI_CAST_PTR (void, (RgnDesc->Region.Address + RegionOffset))));
/* Invoke the appropriate AddressSpace/OpRegion handler */
Status = AcpiEvAddressSpaceDispatch (RgnDesc, Function, RegionOffset,
ACPI_MUL_8 (ObjDesc->CommonField.AccessByteWidth), Value);
if (ACPI_FAILURE (Status))
{
if (Status == AE_NOT_IMPLEMENTED)
{
ACPI_ERROR ((AE_INFO,
"Region %s(0x%X) not implemented",
AcpiUtGetRegionName (RgnDesc->Region.SpaceId),
RgnDesc->Region.SpaceId));
}
else if (Status == AE_NOT_EXIST)
{
ACPI_ERROR ((AE_INFO,
"Region %s(0x%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,
UINT64 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 >= ((UINT64) 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,
UINT64 *Value,
UINT32 ReadWrite)
{
ACPI_STATUS Status;
UINT64 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 (ObjDesc->Common.Type)
{
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,
(UINT64) 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,
(UINT64) 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);
}
if (ReadWrite == ACPI_READ)
{
/* Read the datum from the DataRegister */
ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
"Read from Data Register\n"));
Status = AcpiExExtractFromField (ObjDesc->IndexField.DataObj,
Value, sizeof (UINT64));
}
else
{
/* Write the datum to the DataRegister */
ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
"Write to Data Register: Value %8.8X%8.8X\n",
ACPI_FORMAT_UINT64 (*Value)));
Status = AcpiExInsertIntoField (ObjDesc->IndexField.DataObj,
Value, sizeof (UINT64));
}
break;
default:
ACPI_ERROR ((AE_INFO, "Wrong object type in field I/O %u",
ObjDesc->Common.Type));
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 %u\n",
ACPI_FORMAT_UINT64 (*Value),
ObjDesc->CommonField.AccessByteWidth));
}
else
{
ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
"Value Written %8.8X%8.8X, Width %u\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,
UINT64 Mask,
UINT64 FieldValue,
UINT32 FieldDatumByteOffset)
{
ACPI_STATUS Status = AE_OK;
UINT64 MergedValue;
UINT64 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_UINT64_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))
{
return_ACPI_STATUS (Status);
}
MergedValue |= (CurrentValue & ~Mask);
}
break;
case AML_FIELD_UPDATE_WRITE_AS_ONES:
/* Set positions outside the field to all ones */
MergedValue |= ~Mask;
break;
case AML_FIELD_UPDATE_WRITE_AS_ZEROS:
/* Set positions outside the field to all zeros */
MergedValue &= Mask;
break;
default:
ACPI_ERROR ((AE_INFO,
"Unknown UpdateRule value: 0x%X",
(ObjDesc->CommonField.FieldFlags & AML_FIELD_UPDATE_RULE_MASK)));
return_ACPI_STATUS (AE_AML_OPERAND_VALUE);
}
}
ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
"Mask %8.8X%8.8X, DatumOffset %X, Width %X, Value %8.8X%8.8X, MergedValue %8.8X%8.8X\n",
ACPI_FORMAT_UINT64 (Mask),
FieldDatumByteOffset,
ObjDesc->CommonField.AccessByteWidth,
ACPI_FORMAT_UINT64 (FieldValue),
ACPI_FORMAT_UINT64 (MergedValue)));
/* Write the merged value */
Status = AcpiExFieldDatumIo (ObjDesc, FieldDatumByteOffset,
&MergedValue, ACPI_WRITE);
return_ACPI_STATUS (Status);
}
/*******************************************************************************
*
* FUNCTION: AcpiExExtractFromField
*
* PARAMETERS: ObjDesc - Field to be read
* Buffer - Where to store the field data
* BufferLength - Length of Buffer
*
* RETURN: Status
*
* DESCRIPTION: Retrieve the current value of the given field
*
******************************************************************************/
ACPI_STATUS
AcpiExExtractFromField (
ACPI_OPERAND_OBJECT *ObjDesc,
void *Buffer,
UINT32 BufferLength)
{
ACPI_STATUS Status;
UINT64 RawDatum;
UINT64 MergedDatum;
UINT32 FieldOffset = 0;
UINT32 BufferOffset = 0;
UINT32 BufferTailBits;
UINT32 DatumCount;
UINT32 FieldDatumCount;
UINT32 i;
ACPI_FUNCTION_TRACE (ExExtractFromField);
/* Validate target buffer and clear it */
if (BufferLength <
ACPI_ROUND_BITS_UP_TO_BYTES (ObjDesc->CommonField.BitLength))
{
ACPI_ERROR ((AE_INFO,
"Field size %u (bits) is too large for buffer (%u)",
ObjDesc->CommonField.BitLength, BufferLength));
return_ACPI_STATUS (AE_BUFFER_OVERFLOW);
}
ACPI_MEMSET (Buffer, 0, BufferLength);
/* Compute the number of datums (access width data items) */
DatumCount = ACPI_ROUND_UP_TO (
ObjDesc->CommonField.BitLength,
ObjDesc->CommonField.AccessBitWidth);
FieldDatumCount = ACPI_ROUND_UP_TO (
ObjDesc->CommonField.BitLength +
ObjDesc->CommonField.StartFieldBitOffset,
ObjDesc->CommonField.AccessBitWidth);
/* Priming read from the field */
Status = AcpiExFieldDatumIo (ObjDesc, FieldOffset, &RawDatum, ACPI_READ);
if (ACPI_FAILURE (Status))
{
return_ACPI_STATUS (Status);
}
MergedDatum = RawDatum >> ObjDesc->CommonField.StartFieldBitOffset;
/* Read the rest of the field */
for (i = 1; i < FieldDatumCount; i++)
{
/* Get next input datum from the field */
FieldOffset += ObjDesc->CommonField.AccessByteWidth;
Status = AcpiExFieldDatumIo (ObjDesc, FieldOffset,
&RawDatum, ACPI_READ);
if (ACPI_FAILURE (Status))
{
return_ACPI_STATUS (Status);
}
/*
* Merge with previous datum if necessary.
*
* Note: Before the shift, check if the shift value will be larger than
* the integer size. If so, there is no need to perform the operation.
* This avoids the differences in behavior between different compilers
* concerning shift values larger than the target data width.
*/
if ((ObjDesc->CommonField.AccessBitWidth -
ObjDesc->CommonField.StartFieldBitOffset) < ACPI_INTEGER_BIT_SIZE)
{
MergedDatum |= RawDatum <<
(ObjDesc->CommonField.AccessBitWidth -
ObjDesc->CommonField.StartFieldBitOffset);
}
if (i == DatumCount)
{
break;
}
/* Write merged datum to target buffer */
ACPI_MEMCPY (((char *) Buffer) + BufferOffset, &MergedDatum,
ACPI_MIN(ObjDesc->CommonField.AccessByteWidth,
BufferLength - BufferOffset));
BufferOffset += ObjDesc->CommonField.AccessByteWidth;
MergedDatum = RawDatum >> ObjDesc->CommonField.StartFieldBitOffset;
}
/* Mask off any extra bits in the last datum */
BufferTailBits = ObjDesc->CommonField.BitLength %
ObjDesc->CommonField.AccessBitWidth;
if (BufferTailBits)
{
MergedDatum &= ACPI_MASK_BITS_ABOVE (BufferTailBits);
}
/* Write the last datum to the buffer */
ACPI_MEMCPY (((char *) Buffer) + BufferOffset, &MergedDatum,
ACPI_MIN(ObjDesc->CommonField.AccessByteWidth,
BufferLength - BufferOffset));
return_ACPI_STATUS (AE_OK);
}
/*******************************************************************************
*
* FUNCTION: AcpiExInsertIntoField
*
* PARAMETERS: ObjDesc - Field to be written
* Buffer - Data to be written
* BufferLength - Length of Buffer
*
* RETURN: Status
*
* DESCRIPTION: Store the Buffer contents into the given field
*
******************************************************************************/
ACPI_STATUS
AcpiExInsertIntoField (
ACPI_OPERAND_OBJECT *ObjDesc,
void *Buffer,
UINT32 BufferLength)
{
ACPI_STATUS Status;
UINT64 Mask;
UINT64 WidthMask;
UINT64 MergedDatum;
UINT64 RawDatum = 0;
UINT32 FieldOffset = 0;
UINT32 BufferOffset = 0;
UINT32 BufferTailBits;
UINT32 DatumCount;
UINT32 FieldDatumCount;
UINT32 i;
UINT32 RequiredLength;
void *NewBuffer;
ACPI_FUNCTION_TRACE (ExInsertIntoField);
/* Validate input buffer */
NewBuffer = NULL;
RequiredLength = ACPI_ROUND_BITS_UP_TO_BYTES (
ObjDesc->CommonField.BitLength);
/*
* We must have a buffer that is at least as long as the field
* we are writing to. This is because individual fields are
* indivisible and partial writes are not supported -- as per
* the ACPI specification.
*/
if (BufferLength < RequiredLength)
{
/* We need to create a new buffer */
NewBuffer = ACPI_ALLOCATE_ZEROED (RequiredLength);
if (!NewBuffer)
{
return_ACPI_STATUS (AE_NO_MEMORY);
}
/*
* Copy the original data to the new buffer, starting
* at Byte zero. All unused (upper) bytes of the
* buffer will be 0.
*/
ACPI_MEMCPY ((char *) NewBuffer, (char *) Buffer, BufferLength);
Buffer = NewBuffer;
BufferLength = RequiredLength;
}
/*
* Create the bitmasks used for bit insertion.
* Note: This if/else is used to bypass compiler differences with the
* shift operator
*/
if (ObjDesc->CommonField.AccessBitWidth == ACPI_INTEGER_BIT_SIZE)
{
WidthMask = ACPI_UINT64_MAX;
}
else
{
WidthMask = ACPI_MASK_BITS_ABOVE (ObjDesc->CommonField.AccessBitWidth);
}
Mask = WidthMask &
ACPI_MASK_BITS_BELOW (ObjDesc->CommonField.StartFieldBitOffset);
/* Compute the number of datums (access width data items) */
DatumCount = ACPI_ROUND_UP_TO (ObjDesc->CommonField.BitLength,
ObjDesc->CommonField.AccessBitWidth);
FieldDatumCount = ACPI_ROUND_UP_TO (ObjDesc->CommonField.BitLength +
ObjDesc->CommonField.StartFieldBitOffset,
ObjDesc->CommonField.AccessBitWidth);
/* Get initial Datum from the input buffer */
ACPI_MEMCPY (&RawDatum, Buffer,
ACPI_MIN(ObjDesc->CommonField.AccessByteWidth,
BufferLength - BufferOffset));
MergedDatum = RawDatum << ObjDesc->CommonField.StartFieldBitOffset;
/* Write the entire field */
for (i = 1; i < FieldDatumCount; i++)
{
/* Write merged datum to the target field */
MergedDatum &= Mask;
Status = AcpiExWriteWithUpdateRule (ObjDesc, Mask,
MergedDatum, FieldOffset);
if (ACPI_FAILURE (Status))
{
goto Exit;
}
FieldOffset += ObjDesc->CommonField.AccessByteWidth;
/*
* Start new output datum by merging with previous input datum
* if necessary.
*
* Note: Before the shift, check if the shift value will be larger than
* the integer size. If so, there is no need to perform the operation.
* This avoids the differences in behavior between different compilers
* concerning shift values larger than the target data width.
*/
if ((ObjDesc->CommonField.AccessBitWidth -
ObjDesc->CommonField.StartFieldBitOffset) < ACPI_INTEGER_BIT_SIZE)
{
MergedDatum = RawDatum >>
(ObjDesc->CommonField.AccessBitWidth -
ObjDesc->CommonField.StartFieldBitOffset);
}
else
{
MergedDatum = 0;
}
Mask = WidthMask;
if (i == DatumCount)
{
break;
}
/* Get the next input datum from the buffer */
BufferOffset += ObjDesc->CommonField.AccessByteWidth;
ACPI_MEMCPY (&RawDatum, ((char *) Buffer) + BufferOffset,
ACPI_MIN(ObjDesc->CommonField.AccessByteWidth,
BufferLength - BufferOffset));
MergedDatum |= RawDatum << ObjDesc->CommonField.StartFieldBitOffset;
}
/* Mask off any extra bits in the last datum */
BufferTailBits = (ObjDesc->CommonField.BitLength +
ObjDesc->CommonField.StartFieldBitOffset) %
ObjDesc->CommonField.AccessBitWidth;
if (BufferTailBits)
{
Mask &= ACPI_MASK_BITS_ABOVE (BufferTailBits);
}
/* Write the last datum to the field */
MergedDatum &= Mask;
Status = AcpiExWriteWithUpdateRule (ObjDesc,
Mask, MergedDatum, FieldOffset);
Exit:
/* Free temporary buffer if we used one */
if (NewBuffer)
{
ACPI_FREE (NewBuffer);
}
return_ACPI_STATUS (Status);
}