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CommitLineData
1da177e4
LT
1/******************************************************************************
2 *
1fad8738 3 * Module Name: exprep - ACPI AML field prep utilities
1da177e4
LT
4 *
5 *****************************************************************************/
6
7/*
7735ca0e 8 * Copyright (C) 2000 - 2017, Intel Corp.
1da177e4
LT
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 MERCHANTIBILITY 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
1da177e4 44#include <acpi/acpi.h>
e2f7a777
LB
45#include "accommon.h"
46#include "acinterp.h"
47#include "amlcode.h"
48#include "acnamesp.h"
9ce81784 49#include "acdispat.h"
1da177e4 50
1da177e4 51#define _COMPONENT ACPI_EXECUTER
4be44fcd 52ACPI_MODULE_NAME("exprep")
1da177e4 53
44f6c012 54/* Local prototypes */
44f6c012 55static u32
4be44fcd
LB
56acpi_ex_decode_field_access(union acpi_operand_object *obj_desc,
57 u8 field_flags, u32 * return_byte_alignment);
1da177e4
LT
58
59#ifdef ACPI_UNDER_DEVELOPMENT
44f6c012
RM
60
61static u32
4be44fcd
LB
62acpi_ex_generate_access(u32 field_bit_offset,
63 u32 field_bit_length, u32 region_length);
44f6c012 64
1da177e4
LT
65/*******************************************************************************
66 *
67 * FUNCTION: acpi_ex_generate_access
68 *
69 * PARAMETERS: field_bit_offset - Start of field within parent region/buffer
70 * field_bit_length - Length of field in bits
71 * region_length - Length of parent in bytes
72 *
73 * RETURN: Field granularity (8, 16, 32 or 64) and
74 * byte_alignment (1, 2, 3, or 4)
75 *
76 * DESCRIPTION: Generate an optimal access width for fields defined with the
77 * any_acc keyword.
78 *
79 * NOTE: Need to have the region_length in order to check for boundary
73a3090a
BM
80 * conditions (end-of-region). However, the region_length is a deferred
81 * operation. Therefore, to complete this implementation, the generation
1da177e4
LT
82 * of this access width must be deferred until the region length has
83 * been evaluated.
84 *
85 ******************************************************************************/
86
87static u32
4be44fcd
LB
88acpi_ex_generate_access(u32 field_bit_offset,
89 u32 field_bit_length, u32 region_length)
1da177e4 90{
4be44fcd
LB
91 u32 field_byte_length;
92 u32 field_byte_offset;
93 u32 field_byte_end_offset;
94 u32 access_byte_width;
95 u32 field_start_offset;
96 u32 field_end_offset;
97 u32 minimum_access_width = 0xFFFFFFFF;
98 u32 minimum_accesses = 0xFFFFFFFF;
99 u32 accesses;
100
b229cf92 101 ACPI_FUNCTION_TRACE(ex_generate_access);
1da177e4
LT
102
103 /* Round Field start offset and length to "minimal" byte boundaries */
104
4be44fcd 105 field_byte_offset = ACPI_DIV_8(ACPI_ROUND_DOWN(field_bit_offset, 8));
1fad8738
BM
106
107 field_byte_end_offset =
108 ACPI_DIV_8(ACPI_ROUND_UP(field_bit_length + field_bit_offset, 8));
109
4be44fcd 110 field_byte_length = field_byte_end_offset - field_byte_offset;
1da177e4 111
4be44fcd 112 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
b27d6597 113 "Bit length %u, Bit offset %u\n",
4be44fcd 114 field_bit_length, field_bit_offset));
44f6c012 115
4be44fcd 116 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
b27d6597 117 "Byte Length %u, Byte Offset %u, End Offset %u\n",
4be44fcd
LB
118 field_byte_length, field_byte_offset,
119 field_byte_end_offset));
1da177e4
LT
120
121 /*
122 * Iterative search for the maximum access width that is both aligned
123 * and does not go beyond the end of the region
124 *
125 * Start at byte_acc and work upwards to qword_acc max. (1,2,4,8 bytes)
126 */
4be44fcd
LB
127 for (access_byte_width = 1; access_byte_width <= 8;
128 access_byte_width <<= 1) {
1da177e4 129 /*
44f6c012
RM
130 * 1) Round end offset up to next access boundary and make sure that
131 * this does not go beyond the end of the parent region.
132 * 2) When the Access width is greater than the field_byte_length, we
133 * are done. (This does not optimize for the perfectly aligned
134 * case yet).
1da177e4 135 */
4be44fcd
LB
136 if (ACPI_ROUND_UP(field_byte_end_offset, access_byte_width) <=
137 region_length) {
44f6c012 138 field_start_offset =
4be44fcd
LB
139 ACPI_ROUND_DOWN(field_byte_offset,
140 access_byte_width) /
141 access_byte_width;
44f6c012
RM
142
143 field_end_offset =
4be44fcd
LB
144 ACPI_ROUND_UP((field_byte_length +
145 field_byte_offset),
146 access_byte_width) /
147 access_byte_width;
44f6c012
RM
148
149 accesses = field_end_offset - field_start_offset;
1da177e4 150
4be44fcd 151 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
b27d6597 152 "AccessWidth %u end is within region\n",
4be44fcd 153 access_byte_width));
44f6c012 154
4be44fcd 155 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
b27d6597 156 "Field Start %u, Field End %u -- requires %u accesses\n",
4be44fcd
LB
157 field_start_offset, field_end_offset,
158 accesses));
1da177e4
LT
159
160 /* Single access is optimal */
161
162 if (accesses <= 1) {
4be44fcd 163 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
1fad8738
BM
164 "Entire field can be accessed "
165 "with one operation of size %u\n",
4be44fcd
LB
166 access_byte_width));
167 return_VALUE(access_byte_width);
1da177e4
LT
168 }
169
170 /*
171 * Fits in the region, but requires more than one read/write.
172 * try the next wider access on next iteration
173 */
174 if (accesses < minimum_accesses) {
4be44fcd 175 minimum_accesses = accesses;
1da177e4
LT
176 minimum_access_width = access_byte_width;
177 }
4be44fcd
LB
178 } else {
179 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
b27d6597 180 "AccessWidth %u end is NOT within region\n",
4be44fcd 181 access_byte_width));
1da177e4 182 if (access_byte_width == 1) {
4be44fcd
LB
183 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
184 "Field goes beyond end-of-region!\n"));
1da177e4 185
44f6c012 186 /* Field does not fit in the region at all */
1da177e4 187
4be44fcd 188 return_VALUE(0);
44f6c012
RM
189 }
190
191 /*
192 * This width goes beyond the end-of-region, back off to
193 * previous access
194 */
4be44fcd 195 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
b27d6597 196 "Backing off to previous optimal access width of %u\n",
4be44fcd
LB
197 minimum_access_width));
198 return_VALUE(minimum_access_width);
1da177e4
LT
199 }
200 }
201
44f6c012
RM
202 /*
203 * Could not read/write field with one operation,
204 * just use max access width
205 */
4be44fcd
LB
206 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
207 "Cannot access field in one operation, using width 8\n"));
1fad8738 208
4be44fcd 209 return_VALUE(8);
1da177e4 210}
4be44fcd 211#endif /* ACPI_UNDER_DEVELOPMENT */
1da177e4
LT
212
213/*******************************************************************************
214 *
215 * FUNCTION: acpi_ex_decode_field_access
216 *
44f6c012
RM
217 * PARAMETERS: obj_desc - Field object
218 * field_flags - Encoded fieldflags (contains access bits)
219 * return_byte_alignment - Where the byte alignment is returned
1da177e4
LT
220 *
221 * RETURN: Field granularity (8, 16, 32 or 64) and
222 * byte_alignment (1, 2, 3, or 4)
223 *
224 * DESCRIPTION: Decode the access_type bits of a field definition.
225 *
226 ******************************************************************************/
227
228static u32
4be44fcd
LB
229acpi_ex_decode_field_access(union acpi_operand_object *obj_desc,
230 u8 field_flags, u32 * return_byte_alignment)
1da177e4 231{
4be44fcd
LB
232 u32 access;
233 u32 byte_alignment;
234 u32 bit_length;
1da177e4 235
b229cf92 236 ACPI_FUNCTION_TRACE(ex_decode_field_access);
1da177e4
LT
237
238 access = (field_flags & AML_FIELD_ACCESS_TYPE_MASK);
239
240 switch (access) {
241 case AML_FIELD_ACCESS_ANY:
242
243#ifdef ACPI_UNDER_DEVELOPMENT
44f6c012 244 byte_alignment =
4be44fcd
LB
245 acpi_ex_generate_access(obj_desc->common_field.
246 start_field_bit_offset,
247 obj_desc->common_field.bit_length,
248 0xFFFFFFFF
249 /* Temp until we pass region_length as parameter */
fd350943 250 );
1da177e4
LT
251 bit_length = byte_alignment * 8;
252#endif
253
254 byte_alignment = 1;
255 bit_length = 8;
256 break;
257
258 case AML_FIELD_ACCESS_BYTE:
4be44fcd 259 case AML_FIELD_ACCESS_BUFFER: /* ACPI 2.0 (SMBus Buffer) */
1d1ea1b7 260
1da177e4 261 byte_alignment = 1;
4be44fcd 262 bit_length = 8;
1da177e4
LT
263 break;
264
265 case AML_FIELD_ACCESS_WORD:
1d1ea1b7 266
1da177e4 267 byte_alignment = 2;
4be44fcd 268 bit_length = 16;
1da177e4
LT
269 break;
270
271 case AML_FIELD_ACCESS_DWORD:
1d1ea1b7 272
1da177e4 273 byte_alignment = 4;
4be44fcd 274 bit_length = 32;
1da177e4
LT
275 break;
276
4be44fcd 277 case AML_FIELD_ACCESS_QWORD: /* ACPI 2.0 */
1d1ea1b7 278
1da177e4 279 byte_alignment = 8;
4be44fcd 280 bit_length = 64;
1da177e4
LT
281 break;
282
283 default:
1d1ea1b7 284
1da177e4
LT
285 /* Invalid field access type */
286
f6a22b0b 287 ACPI_ERROR((AE_INFO, "Unknown field access type 0x%X", access));
1fad8738 288
fd1af712 289 return_UINT32(0);
1da177e4
LT
290 }
291
3371c19c 292 if (obj_desc->common.type == ACPI_TYPE_BUFFER_FIELD) {
1da177e4
LT
293 /*
294 * buffer_field access can be on any byte boundary, so the
295 * byte_alignment is always 1 byte -- regardless of any byte_alignment
296 * implied by the field access type.
297 */
298 byte_alignment = 1;
299 }
300
301 *return_byte_alignment = byte_alignment;
fd1af712 302 return_UINT32(bit_length);
1da177e4
LT
303}
304
1da177e4
LT
305/*******************************************************************************
306 *
307 * FUNCTION: acpi_ex_prep_common_field_object
308 *
309 * PARAMETERS: obj_desc - The field object
310 * field_flags - Access, lock_rule, and update_rule.
311 * The format of a field_flag is described
312 * in the ACPI specification
44f6c012 313 * field_attribute - Special attributes (not used)
1da177e4
LT
314 * field_bit_position - Field start position
315 * field_bit_length - Field length in number of bits
316 *
317 * RETURN: Status
318 *
319 * DESCRIPTION: Initialize the areas of the field object that are common
73a3090a 320 * to the various types of fields. Note: This is very "sensitive"
1da177e4
LT
321 * code because we are solving the general case for field
322 * alignment.
323 *
324 ******************************************************************************/
325
326acpi_status
4be44fcd
LB
327acpi_ex_prep_common_field_object(union acpi_operand_object *obj_desc,
328 u8 field_flags,
329 u8 field_attribute,
330 u32 field_bit_position, u32 field_bit_length)
1da177e4 331{
4be44fcd
LB
332 u32 access_bit_width;
333 u32 byte_alignment;
334 u32 nearest_byte_address;
1da177e4 335
b229cf92 336 ACPI_FUNCTION_TRACE(ex_prep_common_field_object);
1da177e4
LT
337
338 /*
339 * Note: the structure being initialized is the
340 * ACPI_COMMON_FIELD_INFO; No structure fields outside of the common
341 * area are initialized by this procedure.
342 */
343 obj_desc->common_field.field_flags = field_flags;
344 obj_desc->common_field.attribute = field_attribute;
345 obj_desc->common_field.bit_length = field_bit_length;
346
347 /*
73a3090a 348 * Decode the access type so we can compute offsets. The access type gives
1da177e4
LT
349 * two pieces of information - the width of each field access and the
350 * necessary byte_alignment (address granularity) of the access.
351 *
352 * For any_acc, the access_bit_width is the largest width that is both
353 * necessary and possible in an attempt to access the whole field in one
73a3090a 354 * I/O operation. However, for any_acc, the byte_alignment is always one
1da177e4
LT
355 * byte.
356 *
357 * For all Buffer Fields, the byte_alignment is always one byte.
358 *
359 * For all other access types (Byte, Word, Dword, Qword), the Bitwidth is
360 * the same (equivalent) as the byte_alignment.
361 */
1fad8738
BM
362 access_bit_width =
363 acpi_ex_decode_field_access(obj_desc, field_flags, &byte_alignment);
1da177e4 364 if (!access_bit_width) {
4be44fcd 365 return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
1da177e4
LT
366 }
367
09387b43 368 /* Setup width (access granularity) fields (values are: 1, 2, 4, 8) */
1da177e4
LT
369
370 obj_desc->common_field.access_byte_width = (u8)
09387b43 371 ACPI_DIV_8(access_bit_width);
1da177e4
LT
372
373 /*
374 * base_byte_offset is the address of the start of the field within the
73a3090a 375 * region. It is the byte address of the first *datum* (field-width data
1da177e4
LT
376 * unit) of the field. (i.e., the first datum that contains at least the
377 * first *bit* of the field.)
378 *
379 * Note: byte_alignment is always either equal to the access_bit_width or 8
380 * (Byte access), and it defines the addressing granularity of the parent
381 * region or buffer.
382 */
383 nearest_byte_address =
4be44fcd 384 ACPI_ROUND_BITS_DOWN_TO_BYTES(field_bit_position);
1da177e4 385 obj_desc->common_field.base_byte_offset = (u32)
4be44fcd 386 ACPI_ROUND_DOWN(nearest_byte_address, byte_alignment);
1da177e4
LT
387
388 /*
389 * start_field_bit_offset is the offset of the first bit of the field within
390 * a field datum.
391 */
392 obj_desc->common_field.start_field_bit_offset = (u8)
4be44fcd
LB
393 (field_bit_position -
394 ACPI_MUL_8(obj_desc->common_field.base_byte_offset));
1da177e4 395
4be44fcd 396 return_ACPI_STATUS(AE_OK);
1da177e4
LT
397}
398
1da177e4
LT
399/*******************************************************************************
400 *
401 * FUNCTION: acpi_ex_prep_field_value
402 *
ba494bee 403 * PARAMETERS: info - Contains all field creation info
1da177e4
LT
404 *
405 * RETURN: Status
406 *
cf48958e
BM
407 * DESCRIPTION: Construct an object of type union acpi_operand_object with a
408 * subtype of def_field and connect it to the parent Node.
1da177e4
LT
409 *
410 ******************************************************************************/
411
4be44fcd 412acpi_status acpi_ex_prep_field_value(struct acpi_create_field_info *info)
1da177e4 413{
4be44fcd 414 union acpi_operand_object *obj_desc;
ef805d95 415 union acpi_operand_object *second_desc = NULL;
4be44fcd 416 acpi_status status;
09387b43
BM
417 u32 access_byte_width;
418 u32 type;
1da177e4 419
b229cf92 420 ACPI_FUNCTION_TRACE(ex_prep_field_value);
1da177e4
LT
421
422 /* Parameter validation */
423
424 if (info->field_type != ACPI_TYPE_LOCAL_INDEX_FIELD) {
425 if (!info->region_node) {
b229cf92 426 ACPI_ERROR((AE_INFO, "Null RegionNode"));
4be44fcd 427 return_ACPI_STATUS(AE_AML_NO_OPERAND);
1da177e4
LT
428 }
429
4be44fcd 430 type = acpi_ns_get_type(info->region_node);
1da177e4 431 if (type != ACPI_TYPE_REGION) {
b8e4d893 432 ACPI_ERROR((AE_INFO,
09387b43
BM
433 "Needed Region, found type 0x%X (%s)", type,
434 acpi_ut_get_type_name(type)));
1da177e4 435
4be44fcd 436 return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
1da177e4
LT
437 }
438 }
439
440 /* Allocate a new field object */
441
4be44fcd 442 obj_desc = acpi_ut_create_internal_object(info->field_type);
1da177e4 443 if (!obj_desc) {
4be44fcd 444 return_ACPI_STATUS(AE_NO_MEMORY);
1da177e4
LT
445 }
446
447 /* Initialize areas of the object that are common to all fields */
448
449 obj_desc->common_field.node = info->field_node;
09387b43
BM
450 status = acpi_ex_prep_common_field_object(obj_desc,
451 info->field_flags,
4be44fcd
LB
452 info->attribute,
453 info->field_bit_position,
454 info->field_bit_length);
455 if (ACPI_FAILURE(status)) {
456 acpi_ut_delete_object_desc(obj_desc);
457 return_ACPI_STATUS(status);
1da177e4
LT
458 }
459
460 /* Initialize areas of the object that are specific to the field type */
461
462 switch (info->field_type) {
463 case ACPI_TYPE_LOCAL_REGION_FIELD:
464
4be44fcd
LB
465 obj_desc->field.region_obj =
466 acpi_ns_get_attached_object(info->region_node);
1da177e4 467
9ce81784
BM
468 /* Fields specific to generic_serial_bus fields */
469
470 obj_desc->field.access_length = info->access_length;
471
472 if (info->connection_node) {
473 second_desc = info->connection_node->object;
474 if (!(second_desc->common.flags & AOPOBJ_DATA_VALID)) {
475 status =
476 acpi_ds_get_buffer_arguments(second_desc);
477 if (ACPI_FAILURE(status)) {
478 acpi_ut_delete_object_desc(obj_desc);
479 return_ACPI_STATUS(status);
480 }
481 }
482
483 obj_desc->field.resource_buffer =
484 second_desc->buffer.pointer;
485 obj_desc->field.resource_length =
486 (u16)second_desc->buffer.length;
487 } else if (info->resource_buffer) {
488 obj_desc->field.resource_buffer = info->resource_buffer;
489 obj_desc->field.resource_length = info->resource_length;
490 }
491
75ec6e55
BM
492 obj_desc->field.pin_number_index = info->pin_number_index;
493
09387b43 494 /* Allow full data read from EC address space */
1da177e4 495
09387b43
BM
496 if ((obj_desc->field.region_obj->region.space_id ==
497 ACPI_ADR_SPACE_EC)
498 && (obj_desc->common_field.bit_length > 8)) {
499 access_byte_width =
500 ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.
501 bit_length);
502
503 /* Maximum byte width supported is 255 */
1da177e4 504
09387b43 505 if (access_byte_width < 256) {
dadf28a1 506 obj_desc->common_field.access_byte_width =
09387b43 507 (u8)access_byte_width;
2060c445 508 }
dadf28a1 509 }
09387b43
BM
510 /* An additional reference for the container */
511
512 acpi_ut_add_reference(obj_desc->field.region_obj);
dadf28a1 513
4be44fcd 514 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
b229cf92 515 "RegionField: BitOff %X, Off %X, Gran %X, Region %p\n",
4be44fcd
LB
516 obj_desc->field.start_field_bit_offset,
517 obj_desc->field.base_byte_offset,
518 obj_desc->field.access_byte_width,
519 obj_desc->field.region_obj));
1da177e4
LT
520 break;
521
1da177e4
LT
522 case ACPI_TYPE_LOCAL_BANK_FIELD:
523
4be44fcd
LB
524 obj_desc->bank_field.value = info->bank_value;
525 obj_desc->bank_field.region_obj =
526 acpi_ns_get_attached_object(info->region_node);
527 obj_desc->bank_field.bank_obj =
528 acpi_ns_get_attached_object(info->register_node);
1da177e4
LT
529
530 /* An additional reference for the attached objects */
531
4be44fcd
LB
532 acpi_ut_add_reference(obj_desc->bank_field.region_obj);
533 acpi_ut_add_reference(obj_desc->bank_field.bank_obj);
1da177e4 534
4be44fcd 535 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
b229cf92 536 "Bank Field: BitOff %X, Off %X, Gran %X, Region %p, BankReg %p\n",
4be44fcd
LB
537 obj_desc->bank_field.start_field_bit_offset,
538 obj_desc->bank_field.base_byte_offset,
539 obj_desc->field.access_byte_width,
540 obj_desc->bank_field.region_obj,
541 obj_desc->bank_field.bank_obj));
ef805d95
LM
542
543 /*
544 * Remember location in AML stream of the field unit
545 * opcode and operands -- since the bank_value
546 * operands must be evaluated.
547 */
548 second_desc = obj_desc->common.next_object;
549 second_desc->extra.aml_start =
b5243764
BM
550 ACPI_CAST_PTR(union acpi_parse_object,
551 info->data_register_node)->named.data;
ef805d95 552 second_desc->extra.aml_length =
b5243764
BM
553 ACPI_CAST_PTR(union acpi_parse_object,
554 info->data_register_node)->named.length;
ef805d95 555
1da177e4
LT
556 break;
557
1da177e4
LT
558 case ACPI_TYPE_LOCAL_INDEX_FIELD:
559
b8e4d893
BM
560 /* Get the Index and Data registers */
561
4be44fcd
LB
562 obj_desc->index_field.index_obj =
563 acpi_ns_get_attached_object(info->register_node);
564 obj_desc->index_field.data_obj =
565 acpi_ns_get_attached_object(info->data_register_node);
4be44fcd
LB
566
567 if (!obj_desc->index_field.data_obj
568 || !obj_desc->index_field.index_obj) {
b8e4d893
BM
569 ACPI_ERROR((AE_INFO,
570 "Null Index Object during field prep"));
4be44fcd
LB
571 acpi_ut_delete_object_desc(obj_desc);
572 return_ACPI_STATUS(AE_AML_INTERNAL);
1da177e4
LT
573 }
574
575 /* An additional reference for the attached objects */
576
4be44fcd
LB
577 acpi_ut_add_reference(obj_desc->index_field.data_obj);
578 acpi_ut_add_reference(obj_desc->index_field.index_obj);
579
b8e4d893 580 /*
b229cf92 581 * April 2006: Changed to match MS behavior
ea936b78 582 *
b8e4d893 583 * The value written to the Index register is the byte offset of the
b229cf92 584 * target field in units of the granularity of the index_field
ea936b78
BM
585 *
586 * Previously, the value was calculated as an index in terms of the
587 * width of the Data register, as below:
588 *
b229cf92
BM
589 * obj_desc->index_field.Value = (u32)
590 * (Info->field_bit_position / ACPI_MUL_8 (
591 * obj_desc->Field.access_byte_width));
592 *
593 * February 2006: Tried value as a byte offset:
594 * obj_desc->index_field.Value = (u32)
595 * ACPI_DIV_8 (Info->field_bit_position);
b8e4d893 596 */
ea936b78 597 obj_desc->index_field.value =
b229cf92
BM
598 (u32) ACPI_ROUND_DOWN(ACPI_DIV_8(info->field_bit_position),
599 obj_desc->index_field.
600 access_byte_width);
b8e4d893 601
4be44fcd 602 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
1fad8738
BM
603 "IndexField: BitOff %X, Off %X, Value %X, "
604 "Gran %X, Index %p, Data %p\n",
4be44fcd
LB
605 obj_desc->index_field.start_field_bit_offset,
606 obj_desc->index_field.base_byte_offset,
607 obj_desc->index_field.value,
608 obj_desc->field.access_byte_width,
609 obj_desc->index_field.index_obj,
610 obj_desc->index_field.data_obj));
1da177e4
LT
611 break;
612
613 default:
1d1ea1b7 614
1da177e4 615 /* No other types should get here */
1d1ea1b7 616
1da177e4
LT
617 break;
618 }
619
620 /*
621 * Store the constructed descriptor (obj_desc) into the parent Node,
622 * preserving the current type of that named_obj.
623 */
1fad8738
BM
624 status =
625 acpi_ns_attach_object(info->field_node, obj_desc,
626 acpi_ns_get_type(info->field_node));
1da177e4 627
4be44fcd 628 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
b229cf92 629 "Set NamedObj %p [%4.4s], ObjDesc %p\n",
4be44fcd
LB
630 info->field_node,
631 acpi_ut_get_node_name(info->field_node), obj_desc));
1da177e4
LT
632
633 /* Remove local reference to the object */
634
4be44fcd
LB
635 acpi_ut_remove_reference(obj_desc);
636 return_ACPI_STATUS(status);
1da177e4 637}