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1
2/******************************************************************************
3 *
4 * Module Name: exprep - ACPI AML (p-code) execution - field prep utilities
5 *
6 *****************************************************************************/
7
8/*
9 * Copyright (C) 2000 - 2005, R. Byron Moore
10 * All rights reserved.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions, and the following disclaimer,
17 * without modification.
18 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
19 * substantially similar to the "NO WARRANTY" disclaimer below
20 * ("Disclaimer") and any redistribution must be conditioned upon
21 * including a substantially similar Disclaimer requirement for further
22 * binary redistribution.
23 * 3. Neither the names of the above-listed copyright holders nor the names
24 * of any contributors may be used to endorse or promote products derived
25 * from this software without specific prior written permission.
26 *
27 * Alternatively, this software may be distributed under the terms of the
28 * GNU General Public License ("GPL") version 2 as published by the Free
29 * Software Foundation.
30 *
31 * NO WARRANTY
32 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
33 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
34 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
35 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
36 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
37 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
38 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
39 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
40 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
41 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
42 * POSSIBILITY OF SUCH DAMAGES.
43 */
44
45
46#include <acpi/acpi.h>
47#include <acpi/acinterp.h>
48#include <acpi/amlcode.h>
49#include <acpi/acnamesp.h>
50
51
52#define _COMPONENT ACPI_EXECUTER
53 ACPI_MODULE_NAME ("exprep")
54
55/* Local prototypes */
56
57static u32
58acpi_ex_decode_field_access (
59 union acpi_operand_object *obj_desc,
60 u8 field_flags,
61 u32 *return_byte_alignment);
62
63
64#ifdef ACPI_UNDER_DEVELOPMENT
65
66static u32
67acpi_ex_generate_access (
68 u32 field_bit_offset,
69 u32 field_bit_length,
70 u32 region_length);
71
72/*******************************************************************************
73 *
74 * FUNCTION: acpi_ex_generate_access
75 *
76 * PARAMETERS: field_bit_offset - Start of field within parent region/buffer
77 * field_bit_length - Length of field in bits
78 * region_length - Length of parent in bytes
79 *
80 * RETURN: Field granularity (8, 16, 32 or 64) and
81 * byte_alignment (1, 2, 3, or 4)
82 *
83 * DESCRIPTION: Generate an optimal access width for fields defined with the
84 * any_acc keyword.
85 *
86 * NOTE: Need to have the region_length in order to check for boundary
87 * conditions (end-of-region). However, the region_length is a deferred
88 * operation. Therefore, to complete this implementation, the generation
89 * of this access width must be deferred until the region length has
90 * been evaluated.
91 *
92 ******************************************************************************/
93
94static u32
95acpi_ex_generate_access (
96 u32 field_bit_offset,
97 u32 field_bit_length,
98 u32 region_length)
99{
100 u32 field_byte_length;
101 u32 field_byte_offset;
102 u32 field_byte_end_offset;
103 u32 access_byte_width;
104 u32 field_start_offset;
105 u32 field_end_offset;
106 u32 minimum_access_width = 0xFFFFFFFF;
107 u32 minimum_accesses = 0xFFFFFFFF;
108 u32 accesses;
109
110
111 ACPI_FUNCTION_TRACE ("ex_generate_access");
112
113
114 /* Round Field start offset and length to "minimal" byte boundaries */
115
116 field_byte_offset = ACPI_DIV_8 (ACPI_ROUND_DOWN (field_bit_offset, 8));
117 field_byte_end_offset = ACPI_DIV_8 (ACPI_ROUND_UP (field_bit_length +
118 field_bit_offset, 8));
119 field_byte_length = field_byte_end_offset - field_byte_offset;
120
121 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
122 "Bit length %d, Bit offset %d\n",
123 field_bit_length, field_bit_offset));
124
125 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
126 "Byte Length %d, Byte Offset %d, End Offset %d\n",
127 field_byte_length, field_byte_offset, field_byte_end_offset));
128
129 /*
130 * Iterative search for the maximum access width that is both aligned
131 * and does not go beyond the end of the region
132 *
133 * Start at byte_acc and work upwards to qword_acc max. (1,2,4,8 bytes)
134 */
135 for (access_byte_width = 1; access_byte_width <= 8; access_byte_width <<= 1) {
136 /*
137 * 1) Round end offset up to next access boundary and make sure that
138 * this does not go beyond the end of the parent region.
139 * 2) When the Access width is greater than the field_byte_length, we
140 * are done. (This does not optimize for the perfectly aligned
141 * case yet).
142 */
143 if (ACPI_ROUND_UP (field_byte_end_offset, access_byte_width) <= region_length) {
144 field_start_offset =
145 ACPI_ROUND_DOWN (field_byte_offset, access_byte_width) /
146 access_byte_width;
147
148 field_end_offset =
149 ACPI_ROUND_UP ((field_byte_length + field_byte_offset),
150 access_byte_width) / access_byte_width;
151
152 accesses = field_end_offset - field_start_offset;
153
154 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
155 "access_width %d end is within region\n", access_byte_width));
156
157 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
158 "Field Start %d, Field End %d -- requires %d accesses\n",
159 field_start_offset, field_end_offset, accesses));
160
161 /* Single access is optimal */
162
163 if (accesses <= 1) {
164 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
165 "Entire field can be accessed with one operation of size %d\n",
166 access_byte_width));
167 return_VALUE (access_byte_width);
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) {
175 minimum_accesses = accesses;
176 minimum_access_width = access_byte_width;
177 }
178 }
179 else {
180 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
181 "access_width %d end is NOT within region\n", access_byte_width));
182 if (access_byte_width == 1) {
183 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
184 "Field goes beyond end-of-region!\n"));
185
186 /* Field does not fit in the region at all */
187
188 return_VALUE (0);
189 }
190
191 /*
192 * This width goes beyond the end-of-region, back off to
193 * previous access
194 */
195 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
196 "Backing off to previous optimal access width of %d\n",
197 minimum_access_width));
198 return_VALUE (minimum_access_width);
199 }
200 }
201
202 /*
203 * Could not read/write field with one operation,
204 * just use max access width
205 */
206 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
207 "Cannot access field in one operation, using width 8\n"));
208 return_VALUE (8);
209}
210#endif /* ACPI_UNDER_DEVELOPMENT */
211
212
213/*******************************************************************************
214 *
215 * FUNCTION: acpi_ex_decode_field_access
216 *
217 * PARAMETERS: obj_desc - Field object
218 * field_flags - Encoded fieldflags (contains access bits)
219 * return_byte_alignment - Where the byte alignment is returned
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
229acpi_ex_decode_field_access (
230 union acpi_operand_object *obj_desc,
231 u8 field_flags,
232 u32 *return_byte_alignment)
233{
234 u32 access;
235 u32 byte_alignment;
236 u32 bit_length;
237
238
239 ACPI_FUNCTION_TRACE ("ex_decode_field_access");
240
241
242 access = (field_flags & AML_FIELD_ACCESS_TYPE_MASK);
243
244 switch (access) {
245 case AML_FIELD_ACCESS_ANY:
246
247#ifdef ACPI_UNDER_DEVELOPMENT
248 byte_alignment =
249 acpi_ex_generate_access (obj_desc->common_field.start_field_bit_offset,
250 obj_desc->common_field.bit_length,
251 0xFFFFFFFF /* Temp until we pass region_length as parameter */);
252 bit_length = byte_alignment * 8;
253#endif
254
255 byte_alignment = 1;
256 bit_length = 8;
257 break;
258
259 case AML_FIELD_ACCESS_BYTE:
260 case AML_FIELD_ACCESS_BUFFER: /* ACPI 2.0 (SMBus Buffer) */
261 byte_alignment = 1;
262 bit_length = 8;
263 break;
264
265 case AML_FIELD_ACCESS_WORD:
266 byte_alignment = 2;
267 bit_length = 16;
268 break;
269
270 case AML_FIELD_ACCESS_DWORD:
271 byte_alignment = 4;
272 bit_length = 32;
273 break;
274
275 case AML_FIELD_ACCESS_QWORD: /* ACPI 2.0 */
276 byte_alignment = 8;
277 bit_length = 64;
278 break;
279
280 default:
281 /* Invalid field access type */
282
283 ACPI_DEBUG_PRINT ((ACPI_DB_ERROR,
284 "Unknown field access type %X\n",
285 access));
286 return_VALUE (0);
287 }
288
289 if (ACPI_GET_OBJECT_TYPE (obj_desc) == ACPI_TYPE_BUFFER_FIELD) {
290 /*
291 * buffer_field access can be on any byte boundary, so the
292 * byte_alignment is always 1 byte -- regardless of any byte_alignment
293 * implied by the field access type.
294 */
295 byte_alignment = 1;
296 }
297
298 *return_byte_alignment = byte_alignment;
299 return_VALUE (bit_length);
300}
301
302
303/*******************************************************************************
304 *
305 * FUNCTION: acpi_ex_prep_common_field_object
306 *
307 * PARAMETERS: obj_desc - The field object
308 * field_flags - Access, lock_rule, and update_rule.
309 * The format of a field_flag is described
310 * in the ACPI specification
311 * field_attribute - Special attributes (not used)
312 * field_bit_position - Field start position
313 * field_bit_length - Field length in number of bits
314 *
315 * RETURN: Status
316 *
317 * DESCRIPTION: Initialize the areas of the field object that are common
318 * to the various types of fields. Note: This is very "sensitive"
319 * code because we are solving the general case for field
320 * alignment.
321 *
322 ******************************************************************************/
323
324acpi_status
325acpi_ex_prep_common_field_object (
326 union acpi_operand_object *obj_desc,
327 u8 field_flags,
328 u8 field_attribute,
329 u32 field_bit_position,
330 u32 field_bit_length)
331{
332 u32 access_bit_width;
333 u32 byte_alignment;
334 u32 nearest_byte_address;
335
336
337 ACPI_FUNCTION_TRACE ("ex_prep_common_field_object");
338
339
340 /*
341 * Note: the structure being initialized is the
342 * ACPI_COMMON_FIELD_INFO; No structure fields outside of the common
343 * area are initialized by this procedure.
344 */
345 obj_desc->common_field.field_flags = field_flags;
346 obj_desc->common_field.attribute = field_attribute;
347 obj_desc->common_field.bit_length = field_bit_length;
348
349 /*
350 * Decode the access type so we can compute offsets. The access type gives
351 * two pieces of information - the width of each field access and the
352 * necessary byte_alignment (address granularity) of the access.
353 *
354 * For any_acc, the access_bit_width is the largest width that is both
355 * necessary and possible in an attempt to access the whole field in one
356 * I/O operation. However, for any_acc, the byte_alignment is always one
357 * byte.
358 *
359 * For all Buffer Fields, the byte_alignment is always one byte.
360 *
361 * For all other access types (Byte, Word, Dword, Qword), the Bitwidth is
362 * the same (equivalent) as the byte_alignment.
363 */
364 access_bit_width = acpi_ex_decode_field_access (obj_desc, field_flags,
365 &byte_alignment);
366 if (!access_bit_width) {
367 return_ACPI_STATUS (AE_AML_OPERAND_VALUE);
368 }
369
370 /* Setup width (access granularity) fields */
371
372 obj_desc->common_field.access_byte_width = (u8)
373 ACPI_DIV_8 (access_bit_width); /* 1, 2, 4, 8 */
374
375 obj_desc->common_field.access_bit_width = (u8) access_bit_width;
376
377 /*
378 * base_byte_offset is the address of the start of the field within the
379 * region. It is the byte address of the first *datum* (field-width data
380 * unit) of the field. (i.e., the first datum that contains at least the
381 * first *bit* of the field.)
382 *
383 * Note: byte_alignment is always either equal to the access_bit_width or 8
384 * (Byte access), and it defines the addressing granularity of the parent
385 * region or buffer.
386 */
387 nearest_byte_address =
388 ACPI_ROUND_BITS_DOWN_TO_BYTES (field_bit_position);
389 obj_desc->common_field.base_byte_offset = (u32)
390 ACPI_ROUND_DOWN (nearest_byte_address, byte_alignment);
391
392 /*
393 * start_field_bit_offset is the offset of the first bit of the field within
394 * a field datum.
395 */
396 obj_desc->common_field.start_field_bit_offset = (u8)
397 (field_bit_position - ACPI_MUL_8 (obj_desc->common_field.base_byte_offset));
398
399 /*
400 * Does the entire field fit within a single field access element? (datum)
401 * (i.e., without crossing a datum boundary)
402 */
403 if ((obj_desc->common_field.start_field_bit_offset + field_bit_length) <=
404 (u16) access_bit_width) {
405 obj_desc->common.flags |= AOPOBJ_SINGLE_DATUM;
406 }
407
408 return_ACPI_STATUS (AE_OK);
409}
410
411
412/*******************************************************************************
413 *
414 * FUNCTION: acpi_ex_prep_field_value
415 *
416 * PARAMETERS: Info - Contains all field creation info
417 *
418 * RETURN: Status
419 *
420 * DESCRIPTION: Construct an union acpi_operand_object of type def_field and
421 * connect it to the parent Node.
422 *
423 ******************************************************************************/
424
425acpi_status
426acpi_ex_prep_field_value (
427 struct acpi_create_field_info *info)
428{
429 union acpi_operand_object *obj_desc;
430 u32 type;
431 acpi_status status;
432
433
434 ACPI_FUNCTION_TRACE ("ex_prep_field_value");
435
436
437 /* Parameter validation */
438
439 if (info->field_type != ACPI_TYPE_LOCAL_INDEX_FIELD) {
440 if (!info->region_node) {
441 ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Null region_node\n"));
442 return_ACPI_STATUS (AE_AML_NO_OPERAND);
443 }
444
445 type = acpi_ns_get_type (info->region_node);
446 if (type != ACPI_TYPE_REGION) {
447 ACPI_DEBUG_PRINT ((ACPI_DB_ERROR,
448 "Needed Region, found type %X (%s)\n",
449 type, acpi_ut_get_type_name (type)));
450
451 return_ACPI_STATUS (AE_AML_OPERAND_TYPE);
452 }
453 }
454
455 /* Allocate a new field object */
456
457 obj_desc = acpi_ut_create_internal_object (info->field_type);
458 if (!obj_desc) {
459 return_ACPI_STATUS (AE_NO_MEMORY);
460 }
461
462 /* Initialize areas of the object that are common to all fields */
463
464 obj_desc->common_field.node = info->field_node;
465 status = acpi_ex_prep_common_field_object (obj_desc, info->field_flags,
466 info->attribute, info->field_bit_position, info->field_bit_length);
467 if (ACPI_FAILURE (status)) {
468 acpi_ut_delete_object_desc (obj_desc);
469 return_ACPI_STATUS (status);
470 }
471
472 /* Initialize areas of the object that are specific to the field type */
473
474 switch (info->field_type) {
475 case ACPI_TYPE_LOCAL_REGION_FIELD:
476
477 obj_desc->field.region_obj = acpi_ns_get_attached_object (info->region_node);
478
479 /* An additional reference for the container */
480
481 acpi_ut_add_reference (obj_desc->field.region_obj);
482
483 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
484 "region_field: bit_off %X, Off %X, Gran %X, Region %p\n",
485 obj_desc->field.start_field_bit_offset, obj_desc->field.base_byte_offset,
486 obj_desc->field.access_byte_width, obj_desc->field.region_obj));
487 break;
488
489
490 case ACPI_TYPE_LOCAL_BANK_FIELD:
491
492 obj_desc->bank_field.value = info->bank_value;
493 obj_desc->bank_field.region_obj = acpi_ns_get_attached_object (
494 info->region_node);
495 obj_desc->bank_field.bank_obj = acpi_ns_get_attached_object (
496 info->register_node);
497
498 /* An additional reference for the attached objects */
499
500 acpi_ut_add_reference (obj_desc->bank_field.region_obj);
501 acpi_ut_add_reference (obj_desc->bank_field.bank_obj);
502
503 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
504 "Bank Field: bit_off %X, Off %X, Gran %X, Region %p, bank_reg %p\n",
505 obj_desc->bank_field.start_field_bit_offset,
506 obj_desc->bank_field.base_byte_offset,
507 obj_desc->field.access_byte_width,
508 obj_desc->bank_field.region_obj,
509 obj_desc->bank_field.bank_obj));
510 break;
511
512
513 case ACPI_TYPE_LOCAL_INDEX_FIELD:
514
515 obj_desc->index_field.index_obj = acpi_ns_get_attached_object (
516 info->register_node);
517 obj_desc->index_field.data_obj = acpi_ns_get_attached_object (
518 info->data_register_node);
519 obj_desc->index_field.value = (u32)
520 (info->field_bit_position / ACPI_MUL_8 (
521 obj_desc->field.access_byte_width));
522
523 if (!obj_desc->index_field.data_obj || !obj_desc->index_field.index_obj) {
524 ACPI_REPORT_ERROR (("Null Index Object during field prep\n"));
525 acpi_ut_delete_object_desc (obj_desc);
526 return_ACPI_STATUS (AE_AML_INTERNAL);
527 }
528
529 /* An additional reference for the attached objects */
530
531 acpi_ut_add_reference (obj_desc->index_field.data_obj);
532 acpi_ut_add_reference (obj_desc->index_field.index_obj);
533
534 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
535 "index_field: bit_off %X, Off %X, Value %X, Gran %X, Index %p, Data %p\n",
536 obj_desc->index_field.start_field_bit_offset,
537 obj_desc->index_field.base_byte_offset,
538 obj_desc->index_field.value,
539 obj_desc->field.access_byte_width,
540 obj_desc->index_field.index_obj,
541 obj_desc->index_field.data_obj));
542 break;
543
544 default:
545 /* No other types should get here */
546 break;
547 }
548
549 /*
550 * Store the constructed descriptor (obj_desc) into the parent Node,
551 * preserving the current type of that named_obj.
552 */
553 status = acpi_ns_attach_object (info->field_node, obj_desc,
554 acpi_ns_get_type (info->field_node));
555
556 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD, "Set named_obj %p [%4.4s], obj_desc %p\n",
557 info->field_node, acpi_ut_get_node_name (info->field_node), obj_desc));
558
559 /* Remove local reference to the object */
560
561 acpi_ut_remove_reference (obj_desc);
562 return_ACPI_STATUS (status);
563}
564