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[deliverable/linux.git] / drivers / acpi / acpica / exfldio.c
1 /******************************************************************************
2 *
3 * Module Name: exfldio - Aml Field I/O
4 *
5 *****************************************************************************/
6
7 /*
8 * Copyright (C) 2000 - 2012, 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 "acevents.h"
49 #include "acdispat.h"
50
51 #define _COMPONENT ACPI_EXECUTER
52 ACPI_MODULE_NAME("exfldio")
53
54 /* Local prototypes */
55 static acpi_status
56 acpi_ex_field_datum_io(union acpi_operand_object *obj_desc,
57 u32 field_datum_byte_offset, u64 *value, u32 read_write);
58
59 static u8
60 acpi_ex_register_overflow(union acpi_operand_object *obj_desc, u64 value);
61
62 static acpi_status
63 acpi_ex_setup_region(union acpi_operand_object *obj_desc,
64 u32 field_datum_byte_offset);
65
66 /*******************************************************************************
67 *
68 * FUNCTION: acpi_ex_setup_region
69 *
70 * PARAMETERS: obj_desc - Field to be read or written
71 * field_datum_byte_offset - Byte offset of this datum within the
72 * parent field
73 *
74 * RETURN: Status
75 *
76 * DESCRIPTION: Common processing for acpi_ex_extract_from_field and
77 * acpi_ex_insert_into_field. Initialize the Region if necessary and
78 * validate the request.
79 *
80 ******************************************************************************/
81
82 static acpi_status
83 acpi_ex_setup_region(union acpi_operand_object *obj_desc,
84 u32 field_datum_byte_offset)
85 {
86 acpi_status status = AE_OK;
87 union acpi_operand_object *rgn_desc;
88 u8 space_id;
89
90 ACPI_FUNCTION_TRACE_U32(ex_setup_region, field_datum_byte_offset);
91
92 rgn_desc = obj_desc->common_field.region_obj;
93
94 /* We must have a valid region */
95
96 if (rgn_desc->common.type != ACPI_TYPE_REGION) {
97 ACPI_ERROR((AE_INFO, "Needed Region, found type 0x%X (%s)",
98 rgn_desc->common.type,
99 acpi_ut_get_object_type_name(rgn_desc)));
100
101 return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
102 }
103
104 space_id = rgn_desc->region.space_id;
105
106 /* Validate the Space ID */
107
108 if (!acpi_is_valid_space_id(space_id)) {
109 ACPI_ERROR((AE_INFO,
110 "Invalid/unknown Address Space ID: 0x%2.2X",
111 space_id));
112 return_ACPI_STATUS(AE_AML_INVALID_SPACE_ID);
113 }
114
115 /*
116 * If the Region Address and Length have not been previously evaluated,
117 * evaluate them now and save the results.
118 */
119 if (!(rgn_desc->common.flags & AOPOBJ_DATA_VALID)) {
120 status = acpi_ds_get_region_arguments(rgn_desc);
121 if (ACPI_FAILURE(status)) {
122 return_ACPI_STATUS(status);
123 }
124 }
125
126 /* Exit if Address/Length have been disallowed by the host OS */
127
128 if (rgn_desc->common.flags & AOPOBJ_INVALID) {
129 return_ACPI_STATUS(AE_AML_ILLEGAL_ADDRESS);
130 }
131
132 /*
133 * Exit now for SMBus, GSBus or IPMI address space, it has a non-linear
134 * address space and the request cannot be directly validated
135 */
136 if (space_id == ACPI_ADR_SPACE_SMBUS ||
137 space_id == ACPI_ADR_SPACE_GSBUS ||
138 space_id == ACPI_ADR_SPACE_IPMI) {
139
140 /* SMBus or IPMI has a non-linear address space */
141
142 return_ACPI_STATUS(AE_OK);
143 }
144 #ifdef ACPI_UNDER_DEVELOPMENT
145 /*
146 * If the Field access is any_acc, we can now compute the optimal
147 * access (because we know know the length of the parent region)
148 */
149 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
150 if (ACPI_FAILURE(status)) {
151 return_ACPI_STATUS(status);
152 }
153 }
154 #endif
155
156 /*
157 * Validate the request. The entire request from the byte offset for a
158 * length of one field datum (access width) must fit within the region.
159 * (Region length is specified in bytes)
160 */
161 if (rgn_desc->region.length <
162 (obj_desc->common_field.base_byte_offset + field_datum_byte_offset +
163 obj_desc->common_field.access_byte_width)) {
164 if (acpi_gbl_enable_interpreter_slack) {
165 /*
166 * Slack mode only: We will go ahead and allow access to this
167 * field if it is within the region length rounded up to the next
168 * access width boundary. acpi_size cast for 64-bit compile.
169 */
170 if (ACPI_ROUND_UP(rgn_desc->region.length,
171 obj_desc->common_field.
172 access_byte_width) >=
173 ((acpi_size) obj_desc->common_field.
174 base_byte_offset +
175 obj_desc->common_field.access_byte_width +
176 field_datum_byte_offset)) {
177 return_ACPI_STATUS(AE_OK);
178 }
179 }
180
181 if (rgn_desc->region.length <
182 obj_desc->common_field.access_byte_width) {
183 /*
184 * This is the case where the access_type (acc_word, etc.) is wider
185 * than the region itself. For example, a region of length one
186 * byte, and a field with Dword access specified.
187 */
188 ACPI_ERROR((AE_INFO,
189 "Field [%4.4s] access width (%u bytes) too large for region [%4.4s] (length %u)",
190 acpi_ut_get_node_name(obj_desc->
191 common_field.node),
192 obj_desc->common_field.access_byte_width,
193 acpi_ut_get_node_name(rgn_desc->region.
194 node),
195 rgn_desc->region.length));
196 }
197
198 /*
199 * Offset rounded up to next multiple of field width
200 * exceeds region length, indicate an error
201 */
202 ACPI_ERROR((AE_INFO,
203 "Field [%4.4s] Base+Offset+Width %u+%u+%u is beyond end of region [%4.4s] (length %u)",
204 acpi_ut_get_node_name(obj_desc->common_field.node),
205 obj_desc->common_field.base_byte_offset,
206 field_datum_byte_offset,
207 obj_desc->common_field.access_byte_width,
208 acpi_ut_get_node_name(rgn_desc->region.node),
209 rgn_desc->region.length));
210
211 return_ACPI_STATUS(AE_AML_REGION_LIMIT);
212 }
213
214 return_ACPI_STATUS(AE_OK);
215 }
216
217 /*******************************************************************************
218 *
219 * FUNCTION: acpi_ex_access_region
220 *
221 * PARAMETERS: obj_desc - Field to be read
222 * field_datum_byte_offset - Byte offset of this datum within the
223 * parent field
224 * value - Where to store value (must at least
225 * 64 bits)
226 * function - Read or Write flag plus other region-
227 * dependent flags
228 *
229 * RETURN: Status
230 *
231 * DESCRIPTION: Read or Write a single field datum to an Operation Region.
232 *
233 ******************************************************************************/
234
235 acpi_status
236 acpi_ex_access_region(union acpi_operand_object *obj_desc,
237 u32 field_datum_byte_offset, u64 *value, u32 function)
238 {
239 acpi_status status;
240 union acpi_operand_object *rgn_desc;
241 u32 region_offset;
242
243 ACPI_FUNCTION_TRACE(ex_access_region);
244
245 /*
246 * Ensure that the region operands are fully evaluated and verify
247 * the validity of the request
248 */
249 status = acpi_ex_setup_region(obj_desc, field_datum_byte_offset);
250 if (ACPI_FAILURE(status)) {
251 return_ACPI_STATUS(status);
252 }
253
254 /*
255 * The physical address of this field datum is:
256 *
257 * 1) The base of the region, plus
258 * 2) The base offset of the field, plus
259 * 3) The current offset into the field
260 */
261 rgn_desc = obj_desc->common_field.region_obj;
262 region_offset =
263 obj_desc->common_field.base_byte_offset + field_datum_byte_offset;
264
265 if ((function & ACPI_IO_MASK) == ACPI_READ) {
266 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[READ]"));
267 } else {
268 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[WRITE]"));
269 }
270
271 ACPI_DEBUG_PRINT_RAW((ACPI_DB_BFIELD,
272 " Region [%s:%X], Width %X, ByteBase %X, Offset %X at %p\n",
273 acpi_ut_get_region_name(rgn_desc->region.
274 space_id),
275 rgn_desc->region.space_id,
276 obj_desc->common_field.access_byte_width,
277 obj_desc->common_field.base_byte_offset,
278 field_datum_byte_offset, ACPI_CAST_PTR(void,
279 (rgn_desc->
280 region.
281 address +
282 region_offset))));
283
284 /* Invoke the appropriate address_space/op_region handler */
285
286 status = acpi_ev_address_space_dispatch(rgn_desc, obj_desc,
287 function, region_offset,
288 ACPI_MUL_8(obj_desc->
289 common_field.
290 access_byte_width),
291 value);
292
293 if (ACPI_FAILURE(status)) {
294 if (status == AE_NOT_IMPLEMENTED) {
295 ACPI_ERROR((AE_INFO,
296 "Region %s (ID=%u) not implemented",
297 acpi_ut_get_region_name(rgn_desc->region.
298 space_id),
299 rgn_desc->region.space_id));
300 } else if (status == AE_NOT_EXIST) {
301 ACPI_ERROR((AE_INFO,
302 "Region %s (ID=%u) has no handler",
303 acpi_ut_get_region_name(rgn_desc->region.
304 space_id),
305 rgn_desc->region.space_id));
306 }
307 }
308
309 return_ACPI_STATUS(status);
310 }
311
312 /*******************************************************************************
313 *
314 * FUNCTION: acpi_ex_register_overflow
315 *
316 * PARAMETERS: obj_desc - Register(Field) to be written
317 * value - Value to be stored
318 *
319 * RETURN: TRUE if value overflows the field, FALSE otherwise
320 *
321 * DESCRIPTION: Check if a value is out of range of the field being written.
322 * Used to check if the values written to Index and Bank registers
323 * are out of range. Normally, the value is simply truncated
324 * to fit the field, but this case is most likely a serious
325 * coding error in the ASL.
326 *
327 ******************************************************************************/
328
329 static u8
330 acpi_ex_register_overflow(union acpi_operand_object *obj_desc, u64 value)
331 {
332 ACPI_FUNCTION_NAME(ex_register_overflow);
333
334 if (obj_desc->common_field.bit_length >= ACPI_INTEGER_BIT_SIZE) {
335 /*
336 * The field is large enough to hold the maximum integer, so we can
337 * never overflow it.
338 */
339 return (FALSE);
340 }
341
342 if (value >= ((u64) 1 << obj_desc->common_field.bit_length)) {
343 /*
344 * The Value is larger than the maximum value that can fit into
345 * the register.
346 */
347 ACPI_ERROR((AE_INFO,
348 "Index value 0x%8.8X%8.8X overflows field width 0x%X",
349 ACPI_FORMAT_UINT64(value),
350 obj_desc->common_field.bit_length));
351
352 return (TRUE);
353 }
354
355 /* The Value will fit into the field with no truncation */
356
357 return (FALSE);
358 }
359
360 /*******************************************************************************
361 *
362 * FUNCTION: acpi_ex_field_datum_io
363 *
364 * PARAMETERS: obj_desc - Field to be read
365 * field_datum_byte_offset - Byte offset of this datum within the
366 * parent field
367 * value - Where to store value (must be 64 bits)
368 * read_write - Read or Write flag
369 *
370 * RETURN: Status
371 *
372 * DESCRIPTION: Read or Write a single datum of a field. The field_type is
373 * demultiplexed here to handle the different types of fields
374 * (buffer_field, region_field, index_field, bank_field)
375 *
376 ******************************************************************************/
377
378 static acpi_status
379 acpi_ex_field_datum_io(union acpi_operand_object *obj_desc,
380 u32 field_datum_byte_offset, u64 *value, u32 read_write)
381 {
382 acpi_status status;
383 u64 local_value;
384
385 ACPI_FUNCTION_TRACE_U32(ex_field_datum_io, field_datum_byte_offset);
386
387 if (read_write == ACPI_READ) {
388 if (!value) {
389 local_value = 0;
390
391 /* To support reads without saving return value */
392 value = &local_value;
393 }
394
395 /* Clear the entire return buffer first, [Very Important!] */
396
397 *value = 0;
398 }
399
400 /*
401 * The four types of fields are:
402 *
403 * buffer_field - Read/write from/to a Buffer
404 * region_field - Read/write from/to a Operation Region.
405 * bank_field - Write to a Bank Register, then read/write from/to an
406 * operation_region
407 * index_field - Write to an Index Register, then read/write from/to a
408 * Data Register
409 */
410 switch (obj_desc->common.type) {
411 case ACPI_TYPE_BUFFER_FIELD:
412 /*
413 * If the buffer_field arguments have not been previously evaluated,
414 * evaluate them now and save the results.
415 */
416 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
417 status = acpi_ds_get_buffer_field_arguments(obj_desc);
418 if (ACPI_FAILURE(status)) {
419 return_ACPI_STATUS(status);
420 }
421 }
422
423 if (read_write == ACPI_READ) {
424 /*
425 * Copy the data from the source buffer.
426 * Length is the field width in bytes.
427 */
428 ACPI_MEMCPY(value,
429 (obj_desc->buffer_field.buffer_obj)->buffer.
430 pointer +
431 obj_desc->buffer_field.base_byte_offset +
432 field_datum_byte_offset,
433 obj_desc->common_field.access_byte_width);
434 } else {
435 /*
436 * Copy the data to the target buffer.
437 * Length is the field width in bytes.
438 */
439 ACPI_MEMCPY((obj_desc->buffer_field.buffer_obj)->buffer.
440 pointer +
441 obj_desc->buffer_field.base_byte_offset +
442 field_datum_byte_offset, value,
443 obj_desc->common_field.access_byte_width);
444 }
445
446 status = AE_OK;
447 break;
448
449 case ACPI_TYPE_LOCAL_BANK_FIELD:
450
451 /*
452 * Ensure that the bank_value is not beyond the capacity of
453 * the register
454 */
455 if (acpi_ex_register_overflow(obj_desc->bank_field.bank_obj,
456 (u64) obj_desc->bank_field.
457 value)) {
458 return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
459 }
460
461 /*
462 * For bank_fields, we must write the bank_value to the bank_register
463 * (itself a region_field) before we can access the data.
464 */
465 status =
466 acpi_ex_insert_into_field(obj_desc->bank_field.bank_obj,
467 &obj_desc->bank_field.value,
468 sizeof(obj_desc->bank_field.
469 value));
470 if (ACPI_FAILURE(status)) {
471 return_ACPI_STATUS(status);
472 }
473
474 /*
475 * Now that the Bank has been selected, fall through to the
476 * region_field case and write the datum to the Operation Region
477 */
478
479 /*lint -fallthrough */
480
481 case ACPI_TYPE_LOCAL_REGION_FIELD:
482 /*
483 * For simple region_fields, we just directly access the owning
484 * Operation Region.
485 */
486 status =
487 acpi_ex_access_region(obj_desc, field_datum_byte_offset,
488 value, read_write);
489 break;
490
491 case ACPI_TYPE_LOCAL_INDEX_FIELD:
492
493 /*
494 * Ensure that the index_value is not beyond the capacity of
495 * the register
496 */
497 if (acpi_ex_register_overflow(obj_desc->index_field.index_obj,
498 (u64) obj_desc->index_field.
499 value)) {
500 return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
501 }
502
503 /* Write the index value to the index_register (itself a region_field) */
504
505 field_datum_byte_offset += obj_desc->index_field.value;
506
507 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
508 "Write to Index Register: Value %8.8X\n",
509 field_datum_byte_offset));
510
511 status =
512 acpi_ex_insert_into_field(obj_desc->index_field.index_obj,
513 &field_datum_byte_offset,
514 sizeof(field_datum_byte_offset));
515 if (ACPI_FAILURE(status)) {
516 return_ACPI_STATUS(status);
517 }
518
519 if (read_write == ACPI_READ) {
520
521 /* Read the datum from the data_register */
522
523 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
524 "Read from Data Register\n"));
525
526 status =
527 acpi_ex_extract_from_field(obj_desc->index_field.
528 data_obj, value,
529 sizeof(u64));
530 } else {
531 /* Write the datum to the data_register */
532
533 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
534 "Write to Data Register: Value %8.8X%8.8X\n",
535 ACPI_FORMAT_UINT64(*value)));
536
537 status =
538 acpi_ex_insert_into_field(obj_desc->index_field.
539 data_obj, value,
540 sizeof(u64));
541 }
542 break;
543
544 default:
545
546 ACPI_ERROR((AE_INFO, "Wrong object type in field I/O %u",
547 obj_desc->common.type));
548 status = AE_AML_INTERNAL;
549 break;
550 }
551
552 if (ACPI_SUCCESS(status)) {
553 if (read_write == ACPI_READ) {
554 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
555 "Value Read %8.8X%8.8X, Width %u\n",
556 ACPI_FORMAT_UINT64(*value),
557 obj_desc->common_field.
558 access_byte_width));
559 } else {
560 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
561 "Value Written %8.8X%8.8X, Width %u\n",
562 ACPI_FORMAT_UINT64(*value),
563 obj_desc->common_field.
564 access_byte_width));
565 }
566 }
567
568 return_ACPI_STATUS(status);
569 }
570
571 /*******************************************************************************
572 *
573 * FUNCTION: acpi_ex_write_with_update_rule
574 *
575 * PARAMETERS: obj_desc - Field to be written
576 * mask - bitmask within field datum
577 * field_value - Value to write
578 * field_datum_byte_offset - Offset of datum within field
579 *
580 * RETURN: Status
581 *
582 * DESCRIPTION: Apply the field update rule to a field write
583 *
584 ******************************************************************************/
585
586 acpi_status
587 acpi_ex_write_with_update_rule(union acpi_operand_object *obj_desc,
588 u64 mask,
589 u64 field_value, u32 field_datum_byte_offset)
590 {
591 acpi_status status = AE_OK;
592 u64 merged_value;
593 u64 current_value;
594
595 ACPI_FUNCTION_TRACE_U32(ex_write_with_update_rule, mask);
596
597 /* Start with the new bits */
598
599 merged_value = field_value;
600
601 /* If the mask is all ones, we don't need to worry about the update rule */
602
603 if (mask != ACPI_UINT64_MAX) {
604
605 /* Decode the update rule */
606
607 switch (obj_desc->common_field.
608 field_flags & AML_FIELD_UPDATE_RULE_MASK) {
609 case AML_FIELD_UPDATE_PRESERVE:
610 /*
611 * Check if update rule needs to be applied (not if mask is all
612 * ones) The left shift drops the bits we want to ignore.
613 */
614 if ((~mask << (ACPI_MUL_8(sizeof(mask)) -
615 ACPI_MUL_8(obj_desc->common_field.
616 access_byte_width))) != 0) {
617 /*
618 * Read the current contents of the byte/word/dword containing
619 * the field, and merge with the new field value.
620 */
621 status =
622 acpi_ex_field_datum_io(obj_desc,
623 field_datum_byte_offset,
624 &current_value,
625 ACPI_READ);
626 if (ACPI_FAILURE(status)) {
627 return_ACPI_STATUS(status);
628 }
629
630 merged_value |= (current_value & ~mask);
631 }
632 break;
633
634 case AML_FIELD_UPDATE_WRITE_AS_ONES:
635
636 /* Set positions outside the field to all ones */
637
638 merged_value |= ~mask;
639 break;
640
641 case AML_FIELD_UPDATE_WRITE_AS_ZEROS:
642
643 /* Set positions outside the field to all zeros */
644
645 merged_value &= mask;
646 break;
647
648 default:
649
650 ACPI_ERROR((AE_INFO,
651 "Unknown UpdateRule value: 0x%X",
652 (obj_desc->common_field.
653 field_flags &
654 AML_FIELD_UPDATE_RULE_MASK)));
655 return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
656 }
657 }
658
659 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
660 "Mask %8.8X%8.8X, DatumOffset %X, Width %X, Value %8.8X%8.8X, MergedValue %8.8X%8.8X\n",
661 ACPI_FORMAT_UINT64(mask),
662 field_datum_byte_offset,
663 obj_desc->common_field.access_byte_width,
664 ACPI_FORMAT_UINT64(field_value),
665 ACPI_FORMAT_UINT64(merged_value)));
666
667 /* Write the merged value */
668
669 status = acpi_ex_field_datum_io(obj_desc, field_datum_byte_offset,
670 &merged_value, ACPI_WRITE);
671
672 return_ACPI_STATUS(status);
673 }
674
675 /*******************************************************************************
676 *
677 * FUNCTION: acpi_ex_extract_from_field
678 *
679 * PARAMETERS: obj_desc - Field to be read
680 * buffer - Where to store the field data
681 * buffer_length - Length of Buffer
682 *
683 * RETURN: Status
684 *
685 * DESCRIPTION: Retrieve the current value of the given field
686 *
687 ******************************************************************************/
688
689 acpi_status
690 acpi_ex_extract_from_field(union acpi_operand_object *obj_desc,
691 void *buffer, u32 buffer_length)
692 {
693 acpi_status status;
694 u64 raw_datum;
695 u64 merged_datum;
696 u32 field_offset = 0;
697 u32 buffer_offset = 0;
698 u32 buffer_tail_bits;
699 u32 datum_count;
700 u32 field_datum_count;
701 u32 access_bit_width;
702 u32 i;
703
704 ACPI_FUNCTION_TRACE(ex_extract_from_field);
705
706 /* Validate target buffer and clear it */
707
708 if (buffer_length <
709 ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length)) {
710 ACPI_ERROR((AE_INFO,
711 "Field size %u (bits) is too large for buffer (%u)",
712 obj_desc->common_field.bit_length, buffer_length));
713
714 return_ACPI_STATUS(AE_BUFFER_OVERFLOW);
715 }
716
717 ACPI_MEMSET(buffer, 0, buffer_length);
718 access_bit_width = ACPI_MUL_8(obj_desc->common_field.access_byte_width);
719
720 /* Handle the simple case here */
721
722 if ((obj_desc->common_field.start_field_bit_offset == 0) &&
723 (obj_desc->common_field.bit_length == access_bit_width)) {
724 status = acpi_ex_field_datum_io(obj_desc, 0, buffer, ACPI_READ);
725 return_ACPI_STATUS(status);
726 }
727
728 /* TBD: Move to common setup code */
729
730 /* Field algorithm is limited to sizeof(u64), truncate if needed */
731
732 if (obj_desc->common_field.access_byte_width > sizeof(u64)) {
733 obj_desc->common_field.access_byte_width = sizeof(u64);
734 access_bit_width = sizeof(u64) * 8;
735 }
736
737 /* Compute the number of datums (access width data items) */
738
739 datum_count =
740 ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
741 access_bit_width);
742
743 field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
744 obj_desc->common_field.
745 start_field_bit_offset,
746 access_bit_width);
747
748 /* Priming read from the field */
749
750 status =
751 acpi_ex_field_datum_io(obj_desc, field_offset, &raw_datum,
752 ACPI_READ);
753 if (ACPI_FAILURE(status)) {
754 return_ACPI_STATUS(status);
755 }
756 merged_datum =
757 raw_datum >> obj_desc->common_field.start_field_bit_offset;
758
759 /* Read the rest of the field */
760
761 for (i = 1; i < field_datum_count; i++) {
762
763 /* Get next input datum from the field */
764
765 field_offset += obj_desc->common_field.access_byte_width;
766 status = acpi_ex_field_datum_io(obj_desc, field_offset,
767 &raw_datum, ACPI_READ);
768 if (ACPI_FAILURE(status)) {
769 return_ACPI_STATUS(status);
770 }
771
772 /*
773 * Merge with previous datum if necessary.
774 *
775 * Note: Before the shift, check if the shift value will be larger than
776 * the integer size. If so, there is no need to perform the operation.
777 * This avoids the differences in behavior between different compilers
778 * concerning shift values larger than the target data width.
779 */
780 if (access_bit_width -
781 obj_desc->common_field.start_field_bit_offset <
782 ACPI_INTEGER_BIT_SIZE) {
783 merged_datum |=
784 raw_datum << (access_bit_width -
785 obj_desc->common_field.
786 start_field_bit_offset);
787 }
788
789 if (i == datum_count) {
790 break;
791 }
792
793 /* Write merged datum to target buffer */
794
795 ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
796 ACPI_MIN(obj_desc->common_field.access_byte_width,
797 buffer_length - buffer_offset));
798
799 buffer_offset += obj_desc->common_field.access_byte_width;
800 merged_datum =
801 raw_datum >> obj_desc->common_field.start_field_bit_offset;
802 }
803
804 /* Mask off any extra bits in the last datum */
805
806 buffer_tail_bits = obj_desc->common_field.bit_length % access_bit_width;
807 if (buffer_tail_bits) {
808 merged_datum &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
809 }
810
811 /* Write the last datum to the buffer */
812
813 ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
814 ACPI_MIN(obj_desc->common_field.access_byte_width,
815 buffer_length - buffer_offset));
816
817 return_ACPI_STATUS(AE_OK);
818 }
819
820 /*******************************************************************************
821 *
822 * FUNCTION: acpi_ex_insert_into_field
823 *
824 * PARAMETERS: obj_desc - Field to be written
825 * buffer - Data to be written
826 * buffer_length - Length of Buffer
827 *
828 * RETURN: Status
829 *
830 * DESCRIPTION: Store the Buffer contents into the given field
831 *
832 ******************************************************************************/
833
834 acpi_status
835 acpi_ex_insert_into_field(union acpi_operand_object *obj_desc,
836 void *buffer, u32 buffer_length)
837 {
838 void *new_buffer;
839 acpi_status status;
840 u64 mask;
841 u64 width_mask;
842 u64 merged_datum;
843 u64 raw_datum = 0;
844 u32 field_offset = 0;
845 u32 buffer_offset = 0;
846 u32 buffer_tail_bits;
847 u32 datum_count;
848 u32 field_datum_count;
849 u32 access_bit_width;
850 u32 required_length;
851 u32 i;
852
853 ACPI_FUNCTION_TRACE(ex_insert_into_field);
854
855 /* Validate input buffer */
856
857 new_buffer = NULL;
858 required_length =
859 ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length);
860 /*
861 * We must have a buffer that is at least as long as the field
862 * we are writing to. This is because individual fields are
863 * indivisible and partial writes are not supported -- as per
864 * the ACPI specification.
865 */
866 if (buffer_length < required_length) {
867
868 /* We need to create a new buffer */
869
870 new_buffer = ACPI_ALLOCATE_ZEROED(required_length);
871 if (!new_buffer) {
872 return_ACPI_STATUS(AE_NO_MEMORY);
873 }
874
875 /*
876 * Copy the original data to the new buffer, starting
877 * at Byte zero. All unused (upper) bytes of the
878 * buffer will be 0.
879 */
880 ACPI_MEMCPY((char *)new_buffer, (char *)buffer, buffer_length);
881 buffer = new_buffer;
882 buffer_length = required_length;
883 }
884
885 /* TBD: Move to common setup code */
886
887 /* Algo is limited to sizeof(u64), so cut the access_byte_width */
888 if (obj_desc->common_field.access_byte_width > sizeof(u64)) {
889 obj_desc->common_field.access_byte_width = sizeof(u64);
890 }
891
892 access_bit_width = ACPI_MUL_8(obj_desc->common_field.access_byte_width);
893
894 /*
895 * Create the bitmasks used for bit insertion.
896 * Note: This if/else is used to bypass compiler differences with the
897 * shift operator
898 */
899 if (access_bit_width == ACPI_INTEGER_BIT_SIZE) {
900 width_mask = ACPI_UINT64_MAX;
901 } else {
902 width_mask = ACPI_MASK_BITS_ABOVE(access_bit_width);
903 }
904
905 mask = width_mask &
906 ACPI_MASK_BITS_BELOW(obj_desc->common_field.start_field_bit_offset);
907
908 /* Compute the number of datums (access width data items) */
909
910 datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
911 access_bit_width);
912
913 field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
914 obj_desc->common_field.
915 start_field_bit_offset,
916 access_bit_width);
917
918 /* Get initial Datum from the input buffer */
919
920 ACPI_MEMCPY(&raw_datum, buffer,
921 ACPI_MIN(obj_desc->common_field.access_byte_width,
922 buffer_length - buffer_offset));
923
924 merged_datum =
925 raw_datum << obj_desc->common_field.start_field_bit_offset;
926
927 /* Write the entire field */
928
929 for (i = 1; i < field_datum_count; i++) {
930
931 /* Write merged datum to the target field */
932
933 merged_datum &= mask;
934 status = acpi_ex_write_with_update_rule(obj_desc, mask,
935 merged_datum,
936 field_offset);
937 if (ACPI_FAILURE(status)) {
938 goto exit;
939 }
940
941 field_offset += obj_desc->common_field.access_byte_width;
942
943 /*
944 * Start new output datum by merging with previous input datum
945 * if necessary.
946 *
947 * Note: Before the shift, check if the shift value will be larger than
948 * the integer size. If so, there is no need to perform the operation.
949 * This avoids the differences in behavior between different compilers
950 * concerning shift values larger than the target data width.
951 */
952 if ((access_bit_width -
953 obj_desc->common_field.start_field_bit_offset) <
954 ACPI_INTEGER_BIT_SIZE) {
955 merged_datum =
956 raw_datum >> (access_bit_width -
957 obj_desc->common_field.
958 start_field_bit_offset);
959 } else {
960 merged_datum = 0;
961 }
962
963 mask = width_mask;
964
965 if (i == datum_count) {
966 break;
967 }
968
969 /* Get the next input datum from the buffer */
970
971 buffer_offset += obj_desc->common_field.access_byte_width;
972 ACPI_MEMCPY(&raw_datum, ((char *)buffer) + buffer_offset,
973 ACPI_MIN(obj_desc->common_field.access_byte_width,
974 buffer_length - buffer_offset));
975
976 merged_datum |=
977 raw_datum << obj_desc->common_field.start_field_bit_offset;
978 }
979
980 /* Mask off any extra bits in the last datum */
981
982 buffer_tail_bits = (obj_desc->common_field.bit_length +
983 obj_desc->common_field.start_field_bit_offset) %
984 access_bit_width;
985 if (buffer_tail_bits) {
986 mask &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
987 }
988
989 /* Write the last datum to the field */
990
991 merged_datum &= mask;
992 status = acpi_ex_write_with_update_rule(obj_desc,
993 mask, merged_datum,
994 field_offset);
995
996 exit:
997 /* Free temporary buffer if we used one */
998
999 if (new_buffer) {
1000 ACPI_FREE(new_buffer);
1001 }
1002 return_ACPI_STATUS(status);
1003 }
Linux kernel - Deliverables
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