1 /******************************************************************************
2  *
3  * Module Name: exprep - ACPI AML field prep utilities
4  *
5  *****************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2022, Intel Corp.
9  * All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions, and the following disclaimer,
16  *    without modification.
17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
18  *    substantially similar to the "NO WARRANTY" disclaimer below
19  *    ("Disclaimer") and any redistribution must be conditioned upon
20  *    including a substantially similar Disclaimer requirement for further
21  *    binary redistribution.
22  * 3. Neither the names of the above-listed copyright holders nor the names
23  *    of any contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * Alternatively, this software may be distributed under the terms of the
27  * GNU General Public License ("GPL") version 2 as published by the Free
28  * Software Foundation.
29  *
30  * NO WARRANTY
31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
41  * POSSIBILITY OF SUCH DAMAGES.
42  */
43 
44 #include "acpi.h"
45 #include "accommon.h"
46 #include "acinterp.h"
47 #include "amlcode.h"
48 #include "acnamesp.h"
49 #include "acdispat.h"
50 
51 
52 #define _COMPONENT          ACPI_EXECUTER
53         ACPI_MODULE_NAME    ("exprep")
54 
55 /* Local prototypes */
56 
57 static UINT32
58 AcpiExDecodeFieldAccess (
59     ACPI_OPERAND_OBJECT     *ObjDesc,
60     UINT8                   FieldFlags,
61     UINT32                  *ReturnByteAlignment);
62 
63 
64 #ifdef ACPI_UNDER_DEVELOPMENT
65 
66 static UINT32
67 AcpiExGenerateAccess (
68     UINT32                  FieldBitOffset,
69     UINT32                  FieldBitLength,
70     UINT32                  RegionLength);
71 
72 
73 /*******************************************************************************
74  *
75  * FUNCTION:    AcpiExGenerateAccess
76  *
77  * PARAMETERS:  FieldBitOffset      - Start of field within parent region/buffer
78  *              FieldBitLength      - Length of field in bits
79  *              RegionLength        - Length of parent in bytes
80  *
81  * RETURN:      Field granularity (8, 16, 32 or 64) and
82  *              ByteAlignment (1, 2, 3, or 4)
83  *
84  * DESCRIPTION: Generate an optimal access width for fields defined with the
85  *              AnyAcc keyword.
86  *
87  * NOTE: Need to have the RegionLength in order to check for boundary
88  *       conditions (end-of-region). However, the RegionLength is a deferred
89  *       operation. Therefore, to complete this implementation, the generation
90  *       of this access width must be deferred until the region length has
91  *       been evaluated.
92  *
93  ******************************************************************************/
94 
95 static UINT32
AcpiExGenerateAccess(UINT32 FieldBitOffset,UINT32 FieldBitLength,UINT32 RegionLength)96 AcpiExGenerateAccess (
97     UINT32                  FieldBitOffset,
98     UINT32                  FieldBitLength,
99     UINT32                  RegionLength)
100 {
101     UINT32                  FieldByteLength;
102     UINT32                  FieldByteOffset;
103     UINT32                  FieldByteEndOffset;
104     UINT32                  AccessByteWidth;
105     UINT32                  FieldStartOffset;
106     UINT32                  FieldEndOffset;
107     UINT32                  MinimumAccessWidth = 0xFFFFFFFF;
108     UINT32                  MinimumAccesses = 0xFFFFFFFF;
109     UINT32                  Accesses;
110 
111 
112     ACPI_FUNCTION_TRACE (ExGenerateAccess);
113 
114 
115     /* Round Field start offset and length to "minimal" byte boundaries */
116 
117     FieldByteOffset = ACPI_DIV_8 (
118         ACPI_ROUND_DOWN (FieldBitOffset, 8));
119 
120     FieldByteEndOffset = ACPI_DIV_8 (
121         ACPI_ROUND_UP (FieldBitLength + FieldBitOffset, 8));
122 
123     FieldByteLength = FieldByteEndOffset - FieldByteOffset;
124 
125     ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
126         "Bit length %u, Bit offset %u\n",
127         FieldBitLength, FieldBitOffset));
128 
129     ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
130         "Byte Length %u, Byte Offset %u, End Offset %u\n",
131         FieldByteLength, FieldByteOffset, FieldByteEndOffset));
132 
133     /*
134      * Iterative search for the maximum access width that is both aligned
135      * and does not go beyond the end of the region
136      *
137      * Start at ByteAcc and work upwards to QwordAcc max. (1,2,4,8 bytes)
138      */
139     for (AccessByteWidth = 1; AccessByteWidth <= 8; AccessByteWidth <<= 1)
140     {
141         /*
142          * 1) Round end offset up to next access boundary and make sure that
143          *    this does not go beyond the end of the parent region.
144          * 2) When the Access width is greater than the FieldByteLength, we
145          *    are done. (This does not optimize for the perfectly aligned
146          *    case yet).
147          */
148         if (ACPI_ROUND_UP (FieldByteEndOffset, AccessByteWidth) <=
149             RegionLength)
150         {
151             FieldStartOffset =
152                 ACPI_ROUND_DOWN (FieldByteOffset, AccessByteWidth) /
153                 AccessByteWidth;
154 
155             FieldEndOffset =
156                 ACPI_ROUND_UP ((FieldByteLength + FieldByteOffset),
157                     AccessByteWidth) / AccessByteWidth;
158 
159             Accesses = FieldEndOffset - FieldStartOffset;
160 
161             ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
162                 "AccessWidth %u end is within region\n", AccessByteWidth));
163 
164             ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
165                 "Field Start %u, Field End %u -- requires %u accesses\n",
166                 FieldStartOffset, FieldEndOffset, Accesses));
167 
168             /* Single access is optimal */
169 
170             if (Accesses <= 1)
171             {
172                 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
173                     "Entire field can be accessed "
174                     "with one operation of size %u\n",
175                     AccessByteWidth));
176                 return_VALUE (AccessByteWidth);
177             }
178 
179             /*
180              * Fits in the region, but requires more than one read/write.
181              * try the next wider access on next iteration
182              */
183             if (Accesses < MinimumAccesses)
184             {
185                 MinimumAccesses = Accesses;
186                 MinimumAccessWidth = AccessByteWidth;
187             }
188         }
189         else
190         {
191             ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
192                 "AccessWidth %u end is NOT within region\n",
193                 AccessByteWidth));
194             if (AccessByteWidth == 1)
195             {
196                 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
197                     "Field goes beyond end-of-region!\n"));
198 
199                 /* Field does not fit in the region at all */
200 
201                 return_VALUE (0);
202             }
203 
204             /*
205              * This width goes beyond the end-of-region, back off to
206              * previous access
207              */
208             ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
209                 "Backing off to previous optimal access width of %u\n",
210                 MinimumAccessWidth));
211             return_VALUE (MinimumAccessWidth);
212         }
213     }
214 
215     /*
216      * Could not read/write field with one operation,
217      * just use max access width
218      */
219     ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
220         "Cannot access field in one operation, using width 8\n"));
221 
222     return_VALUE (8);
223 }
224 #endif /* ACPI_UNDER_DEVELOPMENT */
225 
226 
227 /*******************************************************************************
228  *
229  * FUNCTION:    AcpiExDecodeFieldAccess
230  *
231  * PARAMETERS:  ObjDesc             - Field object
232  *              FieldFlags          - Encoded fieldflags (contains access bits)
233  *              ReturnByteAlignment - Where the byte alignment is returned
234  *
235  * RETURN:      Field granularity (8, 16, 32 or 64) and
236  *              ByteAlignment (1, 2, 3, or 4)
237  *
238  * DESCRIPTION: Decode the AccessType bits of a field definition.
239  *
240  ******************************************************************************/
241 
242 static UINT32
AcpiExDecodeFieldAccess(ACPI_OPERAND_OBJECT * ObjDesc,UINT8 FieldFlags,UINT32 * ReturnByteAlignment)243 AcpiExDecodeFieldAccess (
244     ACPI_OPERAND_OBJECT     *ObjDesc,
245     UINT8                   FieldFlags,
246     UINT32                  *ReturnByteAlignment)
247 {
248     UINT32                  Access;
249     UINT32                  ByteAlignment;
250     UINT32                  BitLength;
251 
252 
253     ACPI_FUNCTION_TRACE (ExDecodeFieldAccess);
254 
255 
256     Access = (FieldFlags & AML_FIELD_ACCESS_TYPE_MASK);
257 
258     switch (Access)
259     {
260     case AML_FIELD_ACCESS_ANY:
261 
262 #ifdef ACPI_UNDER_DEVELOPMENT
263         ByteAlignment =
264             AcpiExGenerateAccess (ObjDesc->CommonField.StartFieldBitOffset,
265                 ObjDesc->CommonField.BitLength,
266                 0xFFFFFFFF /* Temp until we pass RegionLength as parameter */);
267         BitLength = ByteAlignment * 8;
268 #endif
269 
270         ByteAlignment = 1;
271         BitLength = 8;
272         break;
273 
274     case AML_FIELD_ACCESS_BYTE:
275     case AML_FIELD_ACCESS_BUFFER:   /* ACPI 2.0 (SMBus Buffer) */
276 
277         ByteAlignment = 1;
278         BitLength     = 8;
279         break;
280 
281     case AML_FIELD_ACCESS_WORD:
282 
283         ByteAlignment = 2;
284         BitLength     = 16;
285         break;
286 
287     case AML_FIELD_ACCESS_DWORD:
288 
289         ByteAlignment = 4;
290         BitLength     = 32;
291         break;
292 
293     case AML_FIELD_ACCESS_QWORD:    /* ACPI 2.0 */
294 
295         ByteAlignment = 8;
296         BitLength     = 64;
297         break;
298 
299     default:
300 
301         /* Invalid field access type */
302 
303         ACPI_ERROR ((AE_INFO,
304             "Unknown field access type 0x%X",
305             Access));
306 
307         return_UINT32 (0);
308     }
309 
310     if (ObjDesc->Common.Type == ACPI_TYPE_BUFFER_FIELD)
311     {
312         /*
313          * BufferField access can be on any byte boundary, so the
314          * ByteAlignment is always 1 byte -- regardless of any ByteAlignment
315          * implied by the field access type.
316          */
317         ByteAlignment = 1;
318     }
319 
320     *ReturnByteAlignment = ByteAlignment;
321     return_UINT32 (BitLength);
322 }
323 
324 
325 /*******************************************************************************
326  *
327  * FUNCTION:    AcpiExPrepCommonFieldObject
328  *
329  * PARAMETERS:  ObjDesc             - The field object
330  *              FieldFlags          - Access, LockRule, and UpdateRule.
331  *                                    The format of a FieldFlag is described
332  *                                    in the ACPI specification
333  *              FieldAttribute      - Special attributes (not used)
334  *              FieldBitPosition    - Field start position
335  *              FieldBitLength      - Field length in number of bits
336  *
337  * RETURN:      Status
338  *
339  * DESCRIPTION: Initialize the areas of the field object that are common
340  *              to the various types of fields. Note: This is very "sensitive"
341  *              code because we are solving the general case for field
342  *              alignment.
343  *
344  ******************************************************************************/
345 
346 ACPI_STATUS
AcpiExPrepCommonFieldObject(ACPI_OPERAND_OBJECT * ObjDesc,UINT8 FieldFlags,UINT8 FieldAttribute,UINT32 FieldBitPosition,UINT32 FieldBitLength)347 AcpiExPrepCommonFieldObject (
348     ACPI_OPERAND_OBJECT     *ObjDesc,
349     UINT8                   FieldFlags,
350     UINT8                   FieldAttribute,
351     UINT32                  FieldBitPosition,
352     UINT32                  FieldBitLength)
353 {
354     UINT32                  AccessBitWidth;
355     UINT32                  ByteAlignment;
356     UINT32                  NearestByteAddress;
357 
358 
359     ACPI_FUNCTION_TRACE (ExPrepCommonFieldObject);
360 
361 
362     /*
363      * Note: the structure being initialized is the
364      * ACPI_COMMON_FIELD_INFO;  No structure fields outside of the common
365      * area are initialized by this procedure.
366      */
367     ObjDesc->CommonField.FieldFlags = FieldFlags;
368     ObjDesc->CommonField.Attribute  = FieldAttribute;
369     ObjDesc->CommonField.BitLength  = FieldBitLength;
370 
371     /*
372      * Decode the access type so we can compute offsets. The access type gives
373      * two pieces of information - the width of each field access and the
374      * necessary ByteAlignment (address granularity) of the access.
375      *
376      * For AnyAcc, the AccessBitWidth is the largest width that is both
377      * necessary and possible in an attempt to access the whole field in one
378      * I/O operation. However, for AnyAcc, the ByteAlignment is always one
379      * byte.
380      *
381      * For all Buffer Fields, the ByteAlignment is always one byte.
382      *
383      * For all other access types (Byte, Word, Dword, Qword), the Bitwidth is
384      * the same (equivalent) as the ByteAlignment.
385      */
386     AccessBitWidth = AcpiExDecodeFieldAccess (
387         ObjDesc, FieldFlags, &ByteAlignment);
388     if (!AccessBitWidth)
389     {
390         return_ACPI_STATUS (AE_AML_OPERAND_VALUE);
391     }
392 
393     /* Setup width (access granularity) fields (values are: 1, 2, 4, 8) */
394 
395     ObjDesc->CommonField.AccessByteWidth = (UINT8)
396         ACPI_DIV_8 (AccessBitWidth);
397 
398     /*
399      * BaseByteOffset is the address of the start of the field within the
400      * region. It is the byte address of the first *datum* (field-width data
401      * unit) of the field. (i.e., the first datum that contains at least the
402      * first *bit* of the field.)
403      *
404      * Note: ByteAlignment is always either equal to the AccessBitWidth or 8
405      * (Byte access), and it defines the addressing granularity of the parent
406      * region or buffer.
407      */
408     NearestByteAddress =
409         ACPI_ROUND_BITS_DOWN_TO_BYTES (FieldBitPosition);
410     ObjDesc->CommonField.BaseByteOffset = (UINT32)
411         ACPI_ROUND_DOWN (NearestByteAddress, ByteAlignment);
412 
413     /*
414      * StartFieldBitOffset is the offset of the first bit of the field within
415      * a field datum.
416      */
417     ObjDesc->CommonField.StartFieldBitOffset = (UINT8)
418         (FieldBitPosition - ACPI_MUL_8 (ObjDesc->CommonField.BaseByteOffset));
419 
420     return_ACPI_STATUS (AE_OK);
421 }
422 
423 
424 /*******************************************************************************
425  *
426  * FUNCTION:    AcpiExPrepFieldValue
427  *
428  * PARAMETERS:  Info    - Contains all field creation info
429  *
430  * RETURN:      Status
431  *
432  * DESCRIPTION: Construct an object of type ACPI_OPERAND_OBJECT with a
433  *              subtype of DefField and connect it to the parent Node.
434  *
435  ******************************************************************************/
436 
437 ACPI_STATUS
AcpiExPrepFieldValue(ACPI_CREATE_FIELD_INFO * Info)438 AcpiExPrepFieldValue (
439     ACPI_CREATE_FIELD_INFO  *Info)
440 {
441     ACPI_OPERAND_OBJECT     *ObjDesc;
442     ACPI_OPERAND_OBJECT     *SecondDesc = NULL;
443     ACPI_STATUS             Status;
444     UINT32                  AccessByteWidth;
445     UINT32                  Type;
446 
447 
448     ACPI_FUNCTION_TRACE (ExPrepFieldValue);
449 
450 
451     /* Parameter validation */
452 
453     if (Info->FieldType != ACPI_TYPE_LOCAL_INDEX_FIELD)
454     {
455         if (!Info->RegionNode)
456         {
457             ACPI_ERROR ((AE_INFO, "Null RegionNode"));
458             return_ACPI_STATUS (AE_AML_NO_OPERAND);
459         }
460 
461         Type = AcpiNsGetType (Info->RegionNode);
462         if (Type != ACPI_TYPE_REGION)
463         {
464             ACPI_ERROR ((AE_INFO, "Needed Region, found type 0x%X (%s)",
465                 Type, AcpiUtGetTypeName (Type)));
466 
467             return_ACPI_STATUS (AE_AML_OPERAND_TYPE);
468         }
469     }
470 
471     /* Allocate a new field object */
472 
473     ObjDesc = AcpiUtCreateInternalObject (Info->FieldType);
474     if (!ObjDesc)
475     {
476         return_ACPI_STATUS (AE_NO_MEMORY);
477     }
478 
479     /* Initialize areas of the object that are common to all fields */
480 
481     ObjDesc->CommonField.Node = Info->FieldNode;
482     Status = AcpiExPrepCommonFieldObject (ObjDesc,
483         Info->FieldFlags, Info->Attribute,
484         Info->FieldBitPosition, Info->FieldBitLength);
485     if (ACPI_FAILURE (Status))
486     {
487         AcpiUtDeleteObjectDesc (ObjDesc);
488         return_ACPI_STATUS (Status);
489     }
490 
491     /* Initialize areas of the object that are specific to the field type */
492 
493     switch (Info->FieldType)
494     {
495     case ACPI_TYPE_LOCAL_REGION_FIELD:
496 
497         ObjDesc->Field.RegionObj = AcpiNsGetAttachedObject (Info->RegionNode);
498 
499         /* Fields specific to GenericSerialBus fields */
500 
501         ObjDesc->Field.AccessLength = Info->AccessLength;
502 
503         if (Info->ConnectionNode)
504         {
505             SecondDesc = Info->ConnectionNode->Object;
506             if (!(SecondDesc->Common.Flags & AOPOBJ_DATA_VALID))
507             {
508                 Status = AcpiDsGetBufferArguments (SecondDesc);
509                 if (ACPI_FAILURE (Status))
510                 {
511                     AcpiUtDeleteObjectDesc (ObjDesc);
512                     return_ACPI_STATUS (Status);
513                 }
514             }
515 
516             ObjDesc->Field.ResourceBuffer =
517                 SecondDesc->Buffer.Pointer;
518             ObjDesc->Field.ResourceLength =
519                 (UINT16) SecondDesc->Buffer.Length;
520         }
521         else if (Info->ResourceBuffer)
522         {
523             ObjDesc->Field.ResourceBuffer = Info->ResourceBuffer;
524             ObjDesc->Field.ResourceLength = Info->ResourceLength;
525         }
526 
527         ObjDesc->Field.PinNumberIndex = Info->PinNumberIndex;
528 
529         /* Allow full data read from EC address space */
530 
531         if ((ObjDesc->Field.RegionObj->Region.SpaceId == ACPI_ADR_SPACE_EC) &&
532             (ObjDesc->CommonField.BitLength > 8))
533         {
534             AccessByteWidth = ACPI_ROUND_BITS_UP_TO_BYTES (
535                 ObjDesc->CommonField.BitLength);
536 
537             /* Maximum byte width supported is 255 */
538 
539             if (AccessByteWidth < 256)
540             {
541                 ObjDesc->CommonField.AccessByteWidth =
542                     (UINT8) AccessByteWidth;
543             }
544         }
545 
546         ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
547             "RegionField: BitOff %X, Off %X, Gran %X, Region %p\n",
548             ObjDesc->Field.StartFieldBitOffset,
549             ObjDesc->Field.BaseByteOffset,
550             ObjDesc->Field.AccessByteWidth,
551             ObjDesc->Field.RegionObj));
552         break;
553 
554     case ACPI_TYPE_LOCAL_BANK_FIELD:
555 
556         ObjDesc->BankField.Value = Info->BankValue;
557         ObjDesc->BankField.RegionObj =
558             AcpiNsGetAttachedObject (Info->RegionNode);
559         ObjDesc->BankField.BankObj =
560             AcpiNsGetAttachedObject (Info->RegisterNode);
561 
562         /* An additional reference for the attached objects */
563 
564         AcpiUtAddReference (ObjDesc->BankField.RegionObj);
565         AcpiUtAddReference (ObjDesc->BankField.BankObj);
566 
567         ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
568             "Bank Field: BitOff %X, Off %X, Gran %X, Region %p, BankReg %p\n",
569             ObjDesc->BankField.StartFieldBitOffset,
570             ObjDesc->BankField.BaseByteOffset,
571             ObjDesc->Field.AccessByteWidth,
572             ObjDesc->BankField.RegionObj,
573             ObjDesc->BankField.BankObj));
574 
575         /*
576          * Remember location in AML stream of the field unit
577          * opcode and operands -- since the BankValue
578          * operands must be evaluated.
579          */
580         SecondDesc = ObjDesc->Common.NextObject;
581         SecondDesc->Extra.AmlStart = ACPI_CAST_PTR (ACPI_PARSE_OBJECT,
582             Info->DataRegisterNode)->Named.Data;
583         SecondDesc->Extra.AmlLength = ACPI_CAST_PTR (ACPI_PARSE_OBJECT,
584             Info->DataRegisterNode)->Named.Length;
585 
586         break;
587 
588     case ACPI_TYPE_LOCAL_INDEX_FIELD:
589 
590         /* Get the Index and Data registers */
591 
592         ObjDesc->IndexField.IndexObj =
593             AcpiNsGetAttachedObject (Info->RegisterNode);
594         ObjDesc->IndexField.DataObj =
595             AcpiNsGetAttachedObject (Info->DataRegisterNode);
596 
597         if (!ObjDesc->IndexField.DataObj || !ObjDesc->IndexField.IndexObj)
598         {
599             ACPI_ERROR ((AE_INFO, "Null Index Object during field prep"));
600             AcpiUtDeleteObjectDesc (ObjDesc);
601             return_ACPI_STATUS (AE_AML_INTERNAL);
602         }
603 
604         /* An additional reference for the attached objects */
605 
606         AcpiUtAddReference (ObjDesc->IndexField.DataObj);
607         AcpiUtAddReference (ObjDesc->IndexField.IndexObj);
608 
609         /*
610          * April 2006: Changed to match MS behavior
611          *
612          * The value written to the Index register is the byte offset of the
613          * target field in units of the granularity of the IndexField
614          *
615          * Previously, the value was calculated as an index in terms of the
616          * width of the Data register, as below:
617          *
618          *      ObjDesc->IndexField.Value = (UINT32)
619          *          (Info->FieldBitPosition / ACPI_MUL_8 (
620          *              ObjDesc->Field.AccessByteWidth));
621          *
622          * February 2006: Tried value as a byte offset:
623          *      ObjDesc->IndexField.Value = (UINT32)
624          *          ACPI_DIV_8 (Info->FieldBitPosition);
625          */
626         ObjDesc->IndexField.Value = (UINT32) ACPI_ROUND_DOWN (
627             ACPI_DIV_8 (Info->FieldBitPosition),
628             ObjDesc->IndexField.AccessByteWidth);
629 
630         ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
631             "IndexField: BitOff %X, Off %X, Value %X, "
632             "Gran %X, Index %p, Data %p\n",
633             ObjDesc->IndexField.StartFieldBitOffset,
634             ObjDesc->IndexField.BaseByteOffset,
635             ObjDesc->IndexField.Value,
636             ObjDesc->Field.AccessByteWidth,
637             ObjDesc->IndexField.IndexObj,
638             ObjDesc->IndexField.DataObj));
639         break;
640 
641     default:
642 
643         /* No other types should get here */
644 
645         break;
646     }
647 
648     /*
649      * Store the constructed descriptor (ObjDesc) into the parent Node,
650      * preserving the current type of that NamedObj.
651      */
652     Status = AcpiNsAttachObject (
653         Info->FieldNode, ObjDesc, AcpiNsGetType (Info->FieldNode));
654 
655     ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
656         "Set NamedObj %p [%4.4s], ObjDesc %p\n",
657         Info->FieldNode, AcpiUtGetNodeName (Info->FieldNode), ObjDesc));
658 
659     /* Remove local reference to the object */
660 
661     AcpiUtRemoveReference (ObjDesc);
662     return_ACPI_STATUS (Status);
663 }
664