1 /******************************************************************************
3 * Module Name: exprep - ACPI AML field prep utilities
5 *****************************************************************************/
7 /******************************************************************************
11 * Some or all of this work - Copyright (c) 1999 - 2020, Intel Corp.
12 * All rights reserved.
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
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
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;
37 * The above copyright and patent license is granted only if the following
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.
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
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
72 * 3.4. Intel retains all right, title, and interest in and to the Original
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.
80 * 4. Disclaimer and Export Compliance
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
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
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.
114 *****************************************************************************
116 * Alternatively, you may choose to be licensed under the terms of the
119 * Redistribution and use in source and binary forms, with or without
120 * modification, are permitted provided that the following conditions
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.
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.
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.
150 *****************************************************************************/
153 #include "accommon.h"
154 #include "acinterp.h"
156 #include "acnamesp.h"
157 #include "acdispat.h"
160 #define _COMPONENT ACPI_EXECUTER
161 ACPI_MODULE_NAME ("exprep")
163 /* Local prototypes */
166 AcpiExDecodeFieldAccess (
167 ACPI_OPERAND_OBJECT *ObjDesc,
169 UINT32 *ReturnByteAlignment);
172 #ifdef ACPI_UNDER_DEVELOPMENT
175 AcpiExGenerateAccess (
176 UINT32 FieldBitOffset,
177 UINT32 FieldBitLength,
178 UINT32 RegionLength);
181 /*******************************************************************************
183 * FUNCTION: AcpiExGenerateAccess
185 * PARAMETERS: FieldBitOffset - Start of field within parent region/buffer
186 * FieldBitLength - Length of field in bits
187 * RegionLength - Length of parent in bytes
189 * RETURN: Field granularity (8, 16, 32 or 64) and
190 * ByteAlignment (1, 2, 3, or 4)
192 * DESCRIPTION: Generate an optimal access width for fields defined with the
195 * NOTE: Need to have the RegionLength in order to check for boundary
196 * conditions (end-of-region). However, the RegionLength is a deferred
197 * operation. Therefore, to complete this implementation, the generation
198 * of this access width must be deferred until the region length has
201 ******************************************************************************/
204 AcpiExGenerateAccess (
205 UINT32 FieldBitOffset,
206 UINT32 FieldBitLength,
209 UINT32 FieldByteLength;
210 UINT32 FieldByteOffset;
211 UINT32 FieldByteEndOffset;
212 UINT32 AccessByteWidth;
213 UINT32 FieldStartOffset;
214 UINT32 FieldEndOffset;
215 UINT32 MinimumAccessWidth = 0xFFFFFFFF;
216 UINT32 MinimumAccesses = 0xFFFFFFFF;
220 ACPI_FUNCTION_TRACE (ExGenerateAccess);
223 /* Round Field start offset and length to "minimal" byte boundaries */
225 FieldByteOffset = ACPI_DIV_8 (
226 ACPI_ROUND_DOWN (FieldBitOffset, 8));
228 FieldByteEndOffset = ACPI_DIV_8 (
229 ACPI_ROUND_UP (FieldBitLength + FieldBitOffset, 8));
231 FieldByteLength = FieldByteEndOffset - FieldByteOffset;
233 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
234 "Bit length %u, Bit offset %u\n",
235 FieldBitLength, FieldBitOffset));
237 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
238 "Byte Length %u, Byte Offset %u, End Offset %u\n",
239 FieldByteLength, FieldByteOffset, FieldByteEndOffset));
242 * Iterative search for the maximum access width that is both aligned
243 * and does not go beyond the end of the region
245 * Start at ByteAcc and work upwards to QwordAcc max. (1,2,4,8 bytes)
247 for (AccessByteWidth = 1; AccessByteWidth <= 8; AccessByteWidth <<= 1)
250 * 1) Round end offset up to next access boundary and make sure that
251 * this does not go beyond the end of the parent region.
252 * 2) When the Access width is greater than the FieldByteLength, we
253 * are done. (This does not optimize for the perfectly aligned
256 if (ACPI_ROUND_UP (FieldByteEndOffset, AccessByteWidth) <=
260 ACPI_ROUND_DOWN (FieldByteOffset, AccessByteWidth) /
264 ACPI_ROUND_UP ((FieldByteLength + FieldByteOffset),
265 AccessByteWidth) / AccessByteWidth;
267 Accesses = FieldEndOffset - FieldStartOffset;
269 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
270 "AccessWidth %u end is within region\n", AccessByteWidth));
272 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
273 "Field Start %u, Field End %u -- requires %u accesses\n",
274 FieldStartOffset, FieldEndOffset, Accesses));
276 /* Single access is optimal */
280 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
281 "Entire field can be accessed "
282 "with one operation of size %u\n",
284 return_VALUE (AccessByteWidth);
288 * Fits in the region, but requires more than one read/write.
289 * try the next wider access on next iteration
291 if (Accesses < MinimumAccesses)
293 MinimumAccesses = Accesses;
294 MinimumAccessWidth = AccessByteWidth;
299 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
300 "AccessWidth %u end is NOT within region\n",
302 if (AccessByteWidth == 1)
304 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
305 "Field goes beyond end-of-region!\n"));
307 /* Field does not fit in the region at all */
313 * This width goes beyond the end-of-region, back off to
316 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
317 "Backing off to previous optimal access width of %u\n",
318 MinimumAccessWidth));
319 return_VALUE (MinimumAccessWidth);
324 * Could not read/write field with one operation,
325 * just use max access width
327 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
328 "Cannot access field in one operation, using width 8\n"));
332 #endif /* ACPI_UNDER_DEVELOPMENT */
335 /*******************************************************************************
337 * FUNCTION: AcpiExDecodeFieldAccess
339 * PARAMETERS: ObjDesc - Field object
340 * FieldFlags - Encoded fieldflags (contains access bits)
341 * ReturnByteAlignment - Where the byte alignment is returned
343 * RETURN: Field granularity (8, 16, 32 or 64) and
344 * ByteAlignment (1, 2, 3, or 4)
346 * DESCRIPTION: Decode the AccessType bits of a field definition.
348 ******************************************************************************/
351 AcpiExDecodeFieldAccess (
352 ACPI_OPERAND_OBJECT *ObjDesc,
354 UINT32 *ReturnByteAlignment)
357 UINT32 ByteAlignment;
361 ACPI_FUNCTION_TRACE (ExDecodeFieldAccess);
364 Access = (FieldFlags & AML_FIELD_ACCESS_TYPE_MASK);
368 case AML_FIELD_ACCESS_ANY:
370 #ifdef ACPI_UNDER_DEVELOPMENT
372 AcpiExGenerateAccess (ObjDesc->CommonField.StartFieldBitOffset,
373 ObjDesc->CommonField.BitLength,
374 0xFFFFFFFF /* Temp until we pass RegionLength as parameter */);
375 BitLength = ByteAlignment * 8;
382 case AML_FIELD_ACCESS_BYTE:
383 case AML_FIELD_ACCESS_BUFFER: /* ACPI 2.0 (SMBus Buffer) */
389 case AML_FIELD_ACCESS_WORD:
395 case AML_FIELD_ACCESS_DWORD:
401 case AML_FIELD_ACCESS_QWORD: /* ACPI 2.0 */
409 /* Invalid field access type */
411 ACPI_ERROR ((AE_INFO,
412 "Unknown field access type 0x%X",
418 if (ObjDesc->Common.Type == ACPI_TYPE_BUFFER_FIELD)
421 * BufferField access can be on any byte boundary, so the
422 * ByteAlignment is always 1 byte -- regardless of any ByteAlignment
423 * implied by the field access type.
428 *ReturnByteAlignment = ByteAlignment;
429 return_UINT32 (BitLength);
433 /*******************************************************************************
435 * FUNCTION: AcpiExPrepCommonFieldObject
437 * PARAMETERS: ObjDesc - The field object
438 * FieldFlags - Access, LockRule, and UpdateRule.
439 * The format of a FieldFlag is described
440 * in the ACPI specification
441 * FieldAttribute - Special attributes (not used)
442 * FieldBitPosition - Field start position
443 * FieldBitLength - Field length in number of bits
447 * DESCRIPTION: Initialize the areas of the field object that are common
448 * to the various types of fields. Note: This is very "sensitive"
449 * code because we are solving the general case for field
452 ******************************************************************************/
455 AcpiExPrepCommonFieldObject (
456 ACPI_OPERAND_OBJECT *ObjDesc,
458 UINT8 FieldAttribute,
459 UINT32 FieldBitPosition,
460 UINT32 FieldBitLength)
462 UINT32 AccessBitWidth;
463 UINT32 ByteAlignment;
464 UINT32 NearestByteAddress;
467 ACPI_FUNCTION_TRACE (ExPrepCommonFieldObject);
471 * Note: the structure being initialized is the
472 * ACPI_COMMON_FIELD_INFO; No structure fields outside of the common
473 * area are initialized by this procedure.
475 ObjDesc->CommonField.FieldFlags = FieldFlags;
476 ObjDesc->CommonField.Attribute = FieldAttribute;
477 ObjDesc->CommonField.BitLength = FieldBitLength;
480 * Decode the access type so we can compute offsets. The access type gives
481 * two pieces of information - the width of each field access and the
482 * necessary ByteAlignment (address granularity) of the access.
484 * For AnyAcc, the AccessBitWidth is the largest width that is both
485 * necessary and possible in an attempt to access the whole field in one
486 * I/O operation. However, for AnyAcc, the ByteAlignment is always one
489 * For all Buffer Fields, the ByteAlignment is always one byte.
491 * For all other access types (Byte, Word, Dword, Qword), the Bitwidth is
492 * the same (equivalent) as the ByteAlignment.
494 AccessBitWidth = AcpiExDecodeFieldAccess (
495 ObjDesc, FieldFlags, &ByteAlignment);
498 return_ACPI_STATUS (AE_AML_OPERAND_VALUE);
501 /* Setup width (access granularity) fields (values are: 1, 2, 4, 8) */
503 ObjDesc->CommonField.AccessByteWidth = (UINT8)
504 ACPI_DIV_8 (AccessBitWidth);
507 * BaseByteOffset is the address of the start of the field within the
508 * region. It is the byte address of the first *datum* (field-width data
509 * unit) of the field. (i.e., the first datum that contains at least the
510 * first *bit* of the field.)
512 * Note: ByteAlignment is always either equal to the AccessBitWidth or 8
513 * (Byte access), and it defines the addressing granularity of the parent
517 ACPI_ROUND_BITS_DOWN_TO_BYTES (FieldBitPosition);
518 ObjDesc->CommonField.BaseByteOffset = (UINT32)
519 ACPI_ROUND_DOWN (NearestByteAddress, ByteAlignment);
522 * StartFieldBitOffset is the offset of the first bit of the field within
525 ObjDesc->CommonField.StartFieldBitOffset = (UINT8)
526 (FieldBitPosition - ACPI_MUL_8 (ObjDesc->CommonField.BaseByteOffset));
528 return_ACPI_STATUS (AE_OK);
532 /*******************************************************************************
534 * FUNCTION: AcpiExPrepFieldValue
536 * PARAMETERS: Info - Contains all field creation info
540 * DESCRIPTION: Construct an object of type ACPI_OPERAND_OBJECT with a
541 * subtype of DefField and connect it to the parent Node.
543 ******************************************************************************/
546 AcpiExPrepFieldValue (
547 ACPI_CREATE_FIELD_INFO *Info)
549 ACPI_OPERAND_OBJECT *ObjDesc;
550 ACPI_OPERAND_OBJECT *SecondDesc = NULL;
552 UINT32 AccessByteWidth;
556 ACPI_FUNCTION_TRACE (ExPrepFieldValue);
559 /* Parameter validation */
561 if (Info->FieldType != ACPI_TYPE_LOCAL_INDEX_FIELD)
563 if (!Info->RegionNode)
565 ACPI_ERROR ((AE_INFO, "Null RegionNode"));
566 return_ACPI_STATUS (AE_AML_NO_OPERAND);
569 Type = AcpiNsGetType (Info->RegionNode);
570 if (Type != ACPI_TYPE_REGION)
572 ACPI_ERROR ((AE_INFO, "Needed Region, found type 0x%X (%s)",
573 Type, AcpiUtGetTypeName (Type)));
575 return_ACPI_STATUS (AE_AML_OPERAND_TYPE);
579 /* Allocate a new field object */
581 ObjDesc = AcpiUtCreateInternalObject (Info->FieldType);
584 return_ACPI_STATUS (AE_NO_MEMORY);
587 /* Initialize areas of the object that are common to all fields */
589 ObjDesc->CommonField.Node = Info->FieldNode;
590 Status = AcpiExPrepCommonFieldObject (ObjDesc,
591 Info->FieldFlags, Info->Attribute,
592 Info->FieldBitPosition, Info->FieldBitLength);
593 if (ACPI_FAILURE (Status))
595 AcpiUtDeleteObjectDesc (ObjDesc);
596 return_ACPI_STATUS (Status);
599 /* Initialize areas of the object that are specific to the field type */
601 switch (Info->FieldType)
603 case ACPI_TYPE_LOCAL_REGION_FIELD:
605 ObjDesc->Field.RegionObj = AcpiNsGetAttachedObject (Info->RegionNode);
607 /* Fields specific to GenericSerialBus fields */
609 ObjDesc->Field.AccessLength = Info->AccessLength;
611 if (Info->ConnectionNode)
613 SecondDesc = Info->ConnectionNode->Object;
614 if (!(SecondDesc->Common.Flags & AOPOBJ_DATA_VALID))
616 Status = AcpiDsGetBufferArguments (SecondDesc);
617 if (ACPI_FAILURE (Status))
619 AcpiUtDeleteObjectDesc (ObjDesc);
620 return_ACPI_STATUS (Status);
624 ObjDesc->Field.ResourceBuffer =
625 SecondDesc->Buffer.Pointer;
626 ObjDesc->Field.ResourceLength =
627 (UINT16) SecondDesc->Buffer.Length;
629 else if (Info->ResourceBuffer)
631 ObjDesc->Field.ResourceBuffer = Info->ResourceBuffer;
632 ObjDesc->Field.ResourceLength = Info->ResourceLength;
635 ObjDesc->Field.PinNumberIndex = Info->PinNumberIndex;
637 /* Allow full data read from EC address space */
639 if ((ObjDesc->Field.RegionObj->Region.SpaceId == ACPI_ADR_SPACE_EC) &&
640 (ObjDesc->CommonField.BitLength > 8))
642 AccessByteWidth = ACPI_ROUND_BITS_UP_TO_BYTES (
643 ObjDesc->CommonField.BitLength);
645 /* Maximum byte width supported is 255 */
647 if (AccessByteWidth < 256)
649 ObjDesc->CommonField.AccessByteWidth =
650 (UINT8) AccessByteWidth;
654 /* An additional reference for the container */
656 AcpiUtAddReference (ObjDesc->Field.RegionObj);
658 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
659 "RegionField: BitOff %X, Off %X, Gran %X, Region %p\n",
660 ObjDesc->Field.StartFieldBitOffset,
661 ObjDesc->Field.BaseByteOffset,
662 ObjDesc->Field.AccessByteWidth,
663 ObjDesc->Field.RegionObj));
666 case ACPI_TYPE_LOCAL_BANK_FIELD:
668 ObjDesc->BankField.Value = Info->BankValue;
669 ObjDesc->BankField.RegionObj =
670 AcpiNsGetAttachedObject (Info->RegionNode);
671 ObjDesc->BankField.BankObj =
672 AcpiNsGetAttachedObject (Info->RegisterNode);
674 /* An additional reference for the attached objects */
676 AcpiUtAddReference (ObjDesc->BankField.RegionObj);
677 AcpiUtAddReference (ObjDesc->BankField.BankObj);
679 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
680 "Bank Field: BitOff %X, Off %X, Gran %X, Region %p, BankReg %p\n",
681 ObjDesc->BankField.StartFieldBitOffset,
682 ObjDesc->BankField.BaseByteOffset,
683 ObjDesc->Field.AccessByteWidth,
684 ObjDesc->BankField.RegionObj,
685 ObjDesc->BankField.BankObj));
688 * Remember location in AML stream of the field unit
689 * opcode and operands -- since the BankValue
690 * operands must be evaluated.
692 SecondDesc = ObjDesc->Common.NextObject;
693 SecondDesc->Extra.AmlStart = ACPI_CAST_PTR (ACPI_PARSE_OBJECT,
694 Info->DataRegisterNode)->Named.Data;
695 SecondDesc->Extra.AmlLength = ACPI_CAST_PTR (ACPI_PARSE_OBJECT,
696 Info->DataRegisterNode)->Named.Length;
700 case ACPI_TYPE_LOCAL_INDEX_FIELD:
702 /* Get the Index and Data registers */
704 ObjDesc->IndexField.IndexObj =
705 AcpiNsGetAttachedObject (Info->RegisterNode);
706 ObjDesc->IndexField.DataObj =
707 AcpiNsGetAttachedObject (Info->DataRegisterNode);
709 if (!ObjDesc->IndexField.DataObj || !ObjDesc->IndexField.IndexObj)
711 ACPI_ERROR ((AE_INFO, "Null Index Object during field prep"));
712 AcpiUtDeleteObjectDesc (ObjDesc);
713 return_ACPI_STATUS (AE_AML_INTERNAL);
716 /* An additional reference for the attached objects */
718 AcpiUtAddReference (ObjDesc->IndexField.DataObj);
719 AcpiUtAddReference (ObjDesc->IndexField.IndexObj);
722 * April 2006: Changed to match MS behavior
724 * The value written to the Index register is the byte offset of the
725 * target field in units of the granularity of the IndexField
727 * Previously, the value was calculated as an index in terms of the
728 * width of the Data register, as below:
730 * ObjDesc->IndexField.Value = (UINT32)
731 * (Info->FieldBitPosition / ACPI_MUL_8 (
732 * ObjDesc->Field.AccessByteWidth));
734 * February 2006: Tried value as a byte offset:
735 * ObjDesc->IndexField.Value = (UINT32)
736 * ACPI_DIV_8 (Info->FieldBitPosition);
738 ObjDesc->IndexField.Value = (UINT32) ACPI_ROUND_DOWN (
739 ACPI_DIV_8 (Info->FieldBitPosition),
740 ObjDesc->IndexField.AccessByteWidth);
742 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
743 "IndexField: BitOff %X, Off %X, Value %X, "
744 "Gran %X, Index %p, Data %p\n",
745 ObjDesc->IndexField.StartFieldBitOffset,
746 ObjDesc->IndexField.BaseByteOffset,
747 ObjDesc->IndexField.Value,
748 ObjDesc->Field.AccessByteWidth,
749 ObjDesc->IndexField.IndexObj,
750 ObjDesc->IndexField.DataObj));
755 /* No other types should get here */
761 * Store the constructed descriptor (ObjDesc) into the parent Node,
762 * preserving the current type of that NamedObj.
764 Status = AcpiNsAttachObject (
765 Info->FieldNode, ObjDesc, AcpiNsGetType (Info->FieldNode));
767 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
768 "Set NamedObj %p [%4.4s], ObjDesc %p\n",
769 Info->FieldNode, AcpiUtGetNodeName (Info->FieldNode), ObjDesc));
771 /* Remove local reference to the object */
773 AcpiUtRemoveReference (ObjDesc);
774 return_ACPI_STATUS (Status);