ACPICA: Clarify ACPI_FREE_BUFFER usage.
[deliverable/linux.git] / drivers / acpi / acpica / exprep.c
1 /******************************************************************************
2 *
3 * Module Name: exprep - ACPI AML (p-code) execution - field prep utilities
4 *
5 *****************************************************************************/
6
7 /*
8 * Copyright (C) 2000 - 2013, 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 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
44 #include <acpi/acpi.h>
45 #include "accommon.h"
46 #include "acinterp.h"
47 #include "amlcode.h"
48 #include "acnamesp.h"
49 #include "acdispat.h"
50
51 #define _COMPONENT ACPI_EXECUTER
52 ACPI_MODULE_NAME("exprep")
53
54 /* Local prototypes */
55 static u32
56 acpi_ex_decode_field_access(union acpi_operand_object *obj_desc,
57 u8 field_flags, u32 * return_byte_alignment);
58
59 #ifdef ACPI_UNDER_DEVELOPMENT
60
61 static u32
62 acpi_ex_generate_access(u32 field_bit_offset,
63 u32 field_bit_length, u32 region_length);
64
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
80 * conditions (end-of-region). However, the region_length is a deferred
81 * operation. Therefore, to complete this implementation, the generation
82 * of this access width must be deferred until the region length has
83 * been evaluated.
84 *
85 ******************************************************************************/
86
87 static u32
88 acpi_ex_generate_access(u32 field_bit_offset,
89 u32 field_bit_length, u32 region_length)
90 {
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
101 ACPI_FUNCTION_TRACE(ex_generate_access);
102
103 /* Round Field start offset and length to "minimal" byte boundaries */
104
105 field_byte_offset = ACPI_DIV_8(ACPI_ROUND_DOWN(field_bit_offset, 8));
106 field_byte_end_offset = ACPI_DIV_8(ACPI_ROUND_UP(field_bit_length +
107 field_bit_offset, 8));
108 field_byte_length = field_byte_end_offset - field_byte_offset;
109
110 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
111 "Bit length %u, Bit offset %u\n",
112 field_bit_length, field_bit_offset));
113
114 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
115 "Byte Length %u, Byte Offset %u, End Offset %u\n",
116 field_byte_length, field_byte_offset,
117 field_byte_end_offset));
118
119 /*
120 * Iterative search for the maximum access width that is both aligned
121 * and does not go beyond the end of the region
122 *
123 * Start at byte_acc and work upwards to qword_acc max. (1,2,4,8 bytes)
124 */
125 for (access_byte_width = 1; access_byte_width <= 8;
126 access_byte_width <<= 1) {
127 /*
128 * 1) Round end offset up to next access boundary and make sure that
129 * this does not go beyond the end of the parent region.
130 * 2) When the Access width is greater than the field_byte_length, we
131 * are done. (This does not optimize for the perfectly aligned
132 * case yet).
133 */
134 if (ACPI_ROUND_UP(field_byte_end_offset, access_byte_width) <=
135 region_length) {
136 field_start_offset =
137 ACPI_ROUND_DOWN(field_byte_offset,
138 access_byte_width) /
139 access_byte_width;
140
141 field_end_offset =
142 ACPI_ROUND_UP((field_byte_length +
143 field_byte_offset),
144 access_byte_width) /
145 access_byte_width;
146
147 accesses = field_end_offset - field_start_offset;
148
149 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
150 "AccessWidth %u end is within region\n",
151 access_byte_width));
152
153 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
154 "Field Start %u, Field End %u -- requires %u accesses\n",
155 field_start_offset, field_end_offset,
156 accesses));
157
158 /* Single access is optimal */
159
160 if (accesses <= 1) {
161 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
162 "Entire field can be accessed with one operation of size %u\n",
163 access_byte_width));
164 return_VALUE(access_byte_width);
165 }
166
167 /*
168 * Fits in the region, but requires more than one read/write.
169 * try the next wider access on next iteration
170 */
171 if (accesses < minimum_accesses) {
172 minimum_accesses = accesses;
173 minimum_access_width = access_byte_width;
174 }
175 } else {
176 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
177 "AccessWidth %u end is NOT within region\n",
178 access_byte_width));
179 if (access_byte_width == 1) {
180 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
181 "Field goes beyond end-of-region!\n"));
182
183 /* Field does not fit in the region at all */
184
185 return_VALUE(0);
186 }
187
188 /*
189 * This width goes beyond the end-of-region, back off to
190 * previous access
191 */
192 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
193 "Backing off to previous optimal access width of %u\n",
194 minimum_access_width));
195 return_VALUE(minimum_access_width);
196 }
197 }
198
199 /*
200 * Could not read/write field with one operation,
201 * just use max access width
202 */
203 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
204 "Cannot access field in one operation, using width 8\n"));
205 return_VALUE(8);
206 }
207 #endif /* ACPI_UNDER_DEVELOPMENT */
208
209 /*******************************************************************************
210 *
211 * FUNCTION: acpi_ex_decode_field_access
212 *
213 * PARAMETERS: obj_desc - Field object
214 * field_flags - Encoded fieldflags (contains access bits)
215 * return_byte_alignment - Where the byte alignment is returned
216 *
217 * RETURN: Field granularity (8, 16, 32 or 64) and
218 * byte_alignment (1, 2, 3, or 4)
219 *
220 * DESCRIPTION: Decode the access_type bits of a field definition.
221 *
222 ******************************************************************************/
223
224 static u32
225 acpi_ex_decode_field_access(union acpi_operand_object *obj_desc,
226 u8 field_flags, u32 * return_byte_alignment)
227 {
228 u32 access;
229 u32 byte_alignment;
230 u32 bit_length;
231
232 ACPI_FUNCTION_TRACE(ex_decode_field_access);
233
234 access = (field_flags & AML_FIELD_ACCESS_TYPE_MASK);
235
236 switch (access) {
237 case AML_FIELD_ACCESS_ANY:
238
239 #ifdef ACPI_UNDER_DEVELOPMENT
240 byte_alignment =
241 acpi_ex_generate_access(obj_desc->common_field.
242 start_field_bit_offset,
243 obj_desc->common_field.bit_length,
244 0xFFFFFFFF
245 /* Temp until we pass region_length as parameter */
246 );
247 bit_length = byte_alignment * 8;
248 #endif
249
250 byte_alignment = 1;
251 bit_length = 8;
252 break;
253
254 case AML_FIELD_ACCESS_BYTE:
255 case AML_FIELD_ACCESS_BUFFER: /* ACPI 2.0 (SMBus Buffer) */
256
257 byte_alignment = 1;
258 bit_length = 8;
259 break;
260
261 case AML_FIELD_ACCESS_WORD:
262
263 byte_alignment = 2;
264 bit_length = 16;
265 break;
266
267 case AML_FIELD_ACCESS_DWORD:
268
269 byte_alignment = 4;
270 bit_length = 32;
271 break;
272
273 case AML_FIELD_ACCESS_QWORD: /* ACPI 2.0 */
274
275 byte_alignment = 8;
276 bit_length = 64;
277 break;
278
279 default:
280
281 /* Invalid field access type */
282
283 ACPI_ERROR((AE_INFO, "Unknown field access type 0x%X", access));
284 return_UINT32(0);
285 }
286
287 if (obj_desc->common.type == ACPI_TYPE_BUFFER_FIELD) {
288 /*
289 * buffer_field access can be on any byte boundary, so the
290 * byte_alignment is always 1 byte -- regardless of any byte_alignment
291 * implied by the field access type.
292 */
293 byte_alignment = 1;
294 }
295
296 *return_byte_alignment = byte_alignment;
297 return_UINT32(bit_length);
298 }
299
300 /*******************************************************************************
301 *
302 * FUNCTION: acpi_ex_prep_common_field_object
303 *
304 * PARAMETERS: obj_desc - The field object
305 * field_flags - Access, lock_rule, and update_rule.
306 * The format of a field_flag is described
307 * in the ACPI specification
308 * field_attribute - Special attributes (not used)
309 * field_bit_position - Field start position
310 * field_bit_length - Field length in number of bits
311 *
312 * RETURN: Status
313 *
314 * DESCRIPTION: Initialize the areas of the field object that are common
315 * to the various types of fields. Note: This is very "sensitive"
316 * code because we are solving the general case for field
317 * alignment.
318 *
319 ******************************************************************************/
320
321 acpi_status
322 acpi_ex_prep_common_field_object(union acpi_operand_object *obj_desc,
323 u8 field_flags,
324 u8 field_attribute,
325 u32 field_bit_position, u32 field_bit_length)
326 {
327 u32 access_bit_width;
328 u32 byte_alignment;
329 u32 nearest_byte_address;
330
331 ACPI_FUNCTION_TRACE(ex_prep_common_field_object);
332
333 /*
334 * Note: the structure being initialized is the
335 * ACPI_COMMON_FIELD_INFO; No structure fields outside of the common
336 * area are initialized by this procedure.
337 */
338 obj_desc->common_field.field_flags = field_flags;
339 obj_desc->common_field.attribute = field_attribute;
340 obj_desc->common_field.bit_length = field_bit_length;
341
342 /*
343 * Decode the access type so we can compute offsets. The access type gives
344 * two pieces of information - the width of each field access and the
345 * necessary byte_alignment (address granularity) of the access.
346 *
347 * For any_acc, the access_bit_width is the largest width that is both
348 * necessary and possible in an attempt to access the whole field in one
349 * I/O operation. However, for any_acc, the byte_alignment is always one
350 * byte.
351 *
352 * For all Buffer Fields, the byte_alignment is always one byte.
353 *
354 * For all other access types (Byte, Word, Dword, Qword), the Bitwidth is
355 * the same (equivalent) as the byte_alignment.
356 */
357 access_bit_width = acpi_ex_decode_field_access(obj_desc, field_flags,
358 &byte_alignment);
359 if (!access_bit_width) {
360 return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
361 }
362
363 /* Setup width (access granularity) fields (values are: 1, 2, 4, 8) */
364
365 obj_desc->common_field.access_byte_width = (u8)
366 ACPI_DIV_8(access_bit_width);
367
368 /*
369 * base_byte_offset is the address of the start of the field within the
370 * region. It is the byte address of the first *datum* (field-width data
371 * unit) of the field. (i.e., the first datum that contains at least the
372 * first *bit* of the field.)
373 *
374 * Note: byte_alignment is always either equal to the access_bit_width or 8
375 * (Byte access), and it defines the addressing granularity of the parent
376 * region or buffer.
377 */
378 nearest_byte_address =
379 ACPI_ROUND_BITS_DOWN_TO_BYTES(field_bit_position);
380 obj_desc->common_field.base_byte_offset = (u32)
381 ACPI_ROUND_DOWN(nearest_byte_address, byte_alignment);
382
383 /*
384 * start_field_bit_offset is the offset of the first bit of the field within
385 * a field datum.
386 */
387 obj_desc->common_field.start_field_bit_offset = (u8)
388 (field_bit_position -
389 ACPI_MUL_8(obj_desc->common_field.base_byte_offset));
390
391 return_ACPI_STATUS(AE_OK);
392 }
393
394 /*******************************************************************************
395 *
396 * FUNCTION: acpi_ex_prep_field_value
397 *
398 * PARAMETERS: info - Contains all field creation info
399 *
400 * RETURN: Status
401 *
402 * DESCRIPTION: Construct an object of type union acpi_operand_object with a
403 * subtype of def_field and connect it to the parent Node.
404 *
405 ******************************************************************************/
406
407 acpi_status acpi_ex_prep_field_value(struct acpi_create_field_info *info)
408 {
409 union acpi_operand_object *obj_desc;
410 union acpi_operand_object *second_desc = NULL;
411 acpi_status status;
412 u32 access_byte_width;
413 u32 type;
414
415 ACPI_FUNCTION_TRACE(ex_prep_field_value);
416
417 /* Parameter validation */
418
419 if (info->field_type != ACPI_TYPE_LOCAL_INDEX_FIELD) {
420 if (!info->region_node) {
421 ACPI_ERROR((AE_INFO, "Null RegionNode"));
422 return_ACPI_STATUS(AE_AML_NO_OPERAND);
423 }
424
425 type = acpi_ns_get_type(info->region_node);
426 if (type != ACPI_TYPE_REGION) {
427 ACPI_ERROR((AE_INFO,
428 "Needed Region, found type 0x%X (%s)", type,
429 acpi_ut_get_type_name(type)));
430
431 return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
432 }
433 }
434
435 /* Allocate a new field object */
436
437 obj_desc = acpi_ut_create_internal_object(info->field_type);
438 if (!obj_desc) {
439 return_ACPI_STATUS(AE_NO_MEMORY);
440 }
441
442 /* Initialize areas of the object that are common to all fields */
443
444 obj_desc->common_field.node = info->field_node;
445 status = acpi_ex_prep_common_field_object(obj_desc,
446 info->field_flags,
447 info->attribute,
448 info->field_bit_position,
449 info->field_bit_length);
450 if (ACPI_FAILURE(status)) {
451 acpi_ut_delete_object_desc(obj_desc);
452 return_ACPI_STATUS(status);
453 }
454
455 /* Initialize areas of the object that are specific to the field type */
456
457 switch (info->field_type) {
458 case ACPI_TYPE_LOCAL_REGION_FIELD:
459
460 obj_desc->field.region_obj =
461 acpi_ns_get_attached_object(info->region_node);
462
463 /* Fields specific to generic_serial_bus fields */
464
465 obj_desc->field.access_length = info->access_length;
466
467 if (info->connection_node) {
468 second_desc = info->connection_node->object;
469 if (!(second_desc->common.flags & AOPOBJ_DATA_VALID)) {
470 status =
471 acpi_ds_get_buffer_arguments(second_desc);
472 if (ACPI_FAILURE(status)) {
473 acpi_ut_delete_object_desc(obj_desc);
474 return_ACPI_STATUS(status);
475 }
476 }
477
478 obj_desc->field.resource_buffer =
479 second_desc->buffer.pointer;
480 obj_desc->field.resource_length =
481 (u16)second_desc->buffer.length;
482 } else if (info->resource_buffer) {
483 obj_desc->field.resource_buffer = info->resource_buffer;
484 obj_desc->field.resource_length = info->resource_length;
485 }
486
487 /* Allow full data read from EC address space */
488
489 if ((obj_desc->field.region_obj->region.space_id ==
490 ACPI_ADR_SPACE_EC)
491 && (obj_desc->common_field.bit_length > 8)) {
492 access_byte_width =
493 ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.
494 bit_length);
495
496 /* Maximum byte width supported is 255 */
497
498 if (access_byte_width < 256) {
499 obj_desc->common_field.access_byte_width =
500 (u8)access_byte_width;
501 }
502 }
503 /* An additional reference for the container */
504
505 acpi_ut_add_reference(obj_desc->field.region_obj);
506
507 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
508 "RegionField: BitOff %X, Off %X, Gran %X, Region %p\n",
509 obj_desc->field.start_field_bit_offset,
510 obj_desc->field.base_byte_offset,
511 obj_desc->field.access_byte_width,
512 obj_desc->field.region_obj));
513 break;
514
515 case ACPI_TYPE_LOCAL_BANK_FIELD:
516
517 obj_desc->bank_field.value = info->bank_value;
518 obj_desc->bank_field.region_obj =
519 acpi_ns_get_attached_object(info->region_node);
520 obj_desc->bank_field.bank_obj =
521 acpi_ns_get_attached_object(info->register_node);
522
523 /* An additional reference for the attached objects */
524
525 acpi_ut_add_reference(obj_desc->bank_field.region_obj);
526 acpi_ut_add_reference(obj_desc->bank_field.bank_obj);
527
528 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
529 "Bank Field: BitOff %X, Off %X, Gran %X, Region %p, BankReg %p\n",
530 obj_desc->bank_field.start_field_bit_offset,
531 obj_desc->bank_field.base_byte_offset,
532 obj_desc->field.access_byte_width,
533 obj_desc->bank_field.region_obj,
534 obj_desc->bank_field.bank_obj));
535
536 /*
537 * Remember location in AML stream of the field unit
538 * opcode and operands -- since the bank_value
539 * operands must be evaluated.
540 */
541 second_desc = obj_desc->common.next_object;
542 second_desc->extra.aml_start =
543 ACPI_CAST_PTR(union acpi_parse_object,
544 info->data_register_node)->named.data;
545 second_desc->extra.aml_length =
546 ACPI_CAST_PTR(union acpi_parse_object,
547 info->data_register_node)->named.length;
548
549 break;
550
551 case ACPI_TYPE_LOCAL_INDEX_FIELD:
552
553 /* Get the Index and Data registers */
554
555 obj_desc->index_field.index_obj =
556 acpi_ns_get_attached_object(info->register_node);
557 obj_desc->index_field.data_obj =
558 acpi_ns_get_attached_object(info->data_register_node);
559
560 if (!obj_desc->index_field.data_obj
561 || !obj_desc->index_field.index_obj) {
562 ACPI_ERROR((AE_INFO,
563 "Null Index Object during field prep"));
564 acpi_ut_delete_object_desc(obj_desc);
565 return_ACPI_STATUS(AE_AML_INTERNAL);
566 }
567
568 /* An additional reference for the attached objects */
569
570 acpi_ut_add_reference(obj_desc->index_field.data_obj);
571 acpi_ut_add_reference(obj_desc->index_field.index_obj);
572
573 /*
574 * April 2006: Changed to match MS behavior
575 *
576 * The value written to the Index register is the byte offset of the
577 * target field in units of the granularity of the index_field
578 *
579 * Previously, the value was calculated as an index in terms of the
580 * width of the Data register, as below:
581 *
582 * obj_desc->index_field.Value = (u32)
583 * (Info->field_bit_position / ACPI_MUL_8 (
584 * obj_desc->Field.access_byte_width));
585 *
586 * February 2006: Tried value as a byte offset:
587 * obj_desc->index_field.Value = (u32)
588 * ACPI_DIV_8 (Info->field_bit_position);
589 */
590 obj_desc->index_field.value =
591 (u32) ACPI_ROUND_DOWN(ACPI_DIV_8(info->field_bit_position),
592 obj_desc->index_field.
593 access_byte_width);
594
595 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
596 "IndexField: BitOff %X, Off %X, Value %X, Gran %X, Index %p, Data %p\n",
597 obj_desc->index_field.start_field_bit_offset,
598 obj_desc->index_field.base_byte_offset,
599 obj_desc->index_field.value,
600 obj_desc->field.access_byte_width,
601 obj_desc->index_field.index_obj,
602 obj_desc->index_field.data_obj));
603 break;
604
605 default:
606
607 /* No other types should get here */
608
609 break;
610 }
611
612 /*
613 * Store the constructed descriptor (obj_desc) into the parent Node,
614 * preserving the current type of that named_obj.
615 */
616 status = acpi_ns_attach_object(info->field_node, obj_desc,
617 acpi_ns_get_type(info->field_node));
618
619 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
620 "Set NamedObj %p [%4.4s], ObjDesc %p\n",
621 info->field_node,
622 acpi_ut_get_node_name(info->field_node), obj_desc));
623
624 /* Remove local reference to the object */
625
626 acpi_ut_remove_reference(obj_desc);
627 return_ACPI_STATUS(status);
628 }
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