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Merge branch 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux...
[mirror_ubuntu-zesty-kernel.git] / drivers / acpi / acpica / exfldio.c
1 /******************************************************************************
2 *
3 * Module Name: exfldio - Aml Field I/O
4 *
5 *****************************************************************************/
6
7 /*
8 * Copyright (C) 2000 - 2008, 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,
58 acpi_integer * value, u32 read_write);
59
60 static u8
61 acpi_ex_register_overflow(union acpi_operand_object *obj_desc,
62 acpi_integer value);
63
64 static acpi_status
65 acpi_ex_setup_region(union acpi_operand_object *obj_desc,
66 u32 field_datum_byte_offset);
67
68 /*******************************************************************************
69 *
70 * FUNCTION: acpi_ex_setup_region
71 *
72 * PARAMETERS: obj_desc - Field to be read or written
73 * field_datum_byte_offset - Byte offset of this datum within the
74 * parent field
75 *
76 * RETURN: Status
77 *
78 * DESCRIPTION: Common processing for acpi_ex_extract_from_field and
79 * acpi_ex_insert_into_field. Initialize the Region if necessary and
80 * validate the request.
81 *
82 ******************************************************************************/
83
84 static acpi_status
85 acpi_ex_setup_region(union acpi_operand_object *obj_desc,
86 u32 field_datum_byte_offset)
87 {
88 acpi_status status = AE_OK;
89 union acpi_operand_object *rgn_desc;
90
91 ACPI_FUNCTION_TRACE_U32(ex_setup_region, field_datum_byte_offset);
92
93 rgn_desc = obj_desc->common_field.region_obj;
94
95 /* We must have a valid region */
96
97 if (rgn_desc->common.type != ACPI_TYPE_REGION) {
98 ACPI_ERROR((AE_INFO, "Needed Region, found type %X (%s)",
99 rgn_desc->common.type,
100 acpi_ut_get_object_type_name(rgn_desc)));
101
102 return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
103 }
104
105 /*
106 * If the Region Address and Length have not been previously evaluated,
107 * evaluate them now and save the results.
108 */
109 if (!(rgn_desc->common.flags & AOPOBJ_DATA_VALID)) {
110 status = acpi_ds_get_region_arguments(rgn_desc);
111 if (ACPI_FAILURE(status)) {
112 return_ACPI_STATUS(status);
113 }
114 }
115
116 /* Exit if Address/Length have been disallowed by the host OS */
117
118 if (rgn_desc->common.flags & AOPOBJ_INVALID) {
119 return_ACPI_STATUS(AE_AML_ILLEGAL_ADDRESS);
120 }
121
122 /*
123 * Exit now for SMBus or IPMI address space, it has a non-linear address space
124 * and the request cannot be directly validated
125 */
126 if (rgn_desc->region.space_id == ACPI_ADR_SPACE_SMBUS ||
127 rgn_desc->region.space_id == ACPI_ADR_SPACE_IPMI) {
128
129 /* SMBus or IPMI has a non-linear address space */
130
131 return_ACPI_STATUS(AE_OK);
132 }
133 #ifdef ACPI_UNDER_DEVELOPMENT
134 /*
135 * If the Field access is any_acc, we can now compute the optimal
136 * access (because we know know the length of the parent region)
137 */
138 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
139 if (ACPI_FAILURE(status)) {
140 return_ACPI_STATUS(status);
141 }
142 }
143 #endif
144
145 /*
146 * Validate the request. The entire request from the byte offset for a
147 * length of one field datum (access width) must fit within the region.
148 * (Region length is specified in bytes)
149 */
150 if (rgn_desc->region.length <
151 (obj_desc->common_field.base_byte_offset +
152 field_datum_byte_offset +
153 obj_desc->common_field.access_byte_width)) {
154 if (acpi_gbl_enable_interpreter_slack) {
155 /*
156 * Slack mode only: We will go ahead and allow access to this
157 * field if it is within the region length rounded up to the next
158 * access width boundary. acpi_size cast for 64-bit compile.
159 */
160 if (ACPI_ROUND_UP(rgn_desc->region.length,
161 obj_desc->common_field.
162 access_byte_width) >=
163 ((acpi_size) obj_desc->common_field.
164 base_byte_offset +
165 obj_desc->common_field.access_byte_width +
166 field_datum_byte_offset)) {
167 return_ACPI_STATUS(AE_OK);
168 }
169 }
170
171 if (rgn_desc->region.length <
172 obj_desc->common_field.access_byte_width) {
173 /*
174 * This is the case where the access_type (acc_word, etc.) is wider
175 * than the region itself. For example, a region of length one
176 * byte, and a field with Dword access specified.
177 */
178 ACPI_ERROR((AE_INFO,
179 "Field [%4.4s] access width (%d bytes) too large for region [%4.4s] (length %X)",
180 acpi_ut_get_node_name(obj_desc->
181 common_field.node),
182 obj_desc->common_field.access_byte_width,
183 acpi_ut_get_node_name(rgn_desc->region.
184 node),
185 rgn_desc->region.length));
186 }
187
188 /*
189 * Offset rounded up to next multiple of field width
190 * exceeds region length, indicate an error
191 */
192 ACPI_ERROR((AE_INFO,
193 "Field [%4.4s] Base+Offset+Width %X+%X+%X is beyond end of region [%4.4s] (length %X)",
194 acpi_ut_get_node_name(obj_desc->common_field.node),
195 obj_desc->common_field.base_byte_offset,
196 field_datum_byte_offset,
197 obj_desc->common_field.access_byte_width,
198 acpi_ut_get_node_name(rgn_desc->region.node),
199 rgn_desc->region.length));
200
201 return_ACPI_STATUS(AE_AML_REGION_LIMIT);
202 }
203
204 return_ACPI_STATUS(AE_OK);
205 }
206
207 /*******************************************************************************
208 *
209 * FUNCTION: acpi_ex_access_region
210 *
211 * PARAMETERS: obj_desc - Field to be read
212 * field_datum_byte_offset - Byte offset of this datum within the
213 * parent field
214 * Value - Where to store value (must at least
215 * the size of acpi_integer)
216 * Function - Read or Write flag plus other region-
217 * dependent flags
218 *
219 * RETURN: Status
220 *
221 * DESCRIPTION: Read or Write a single field datum to an Operation Region.
222 *
223 ******************************************************************************/
224
225 acpi_status
226 acpi_ex_access_region(union acpi_operand_object *obj_desc,
227 u32 field_datum_byte_offset,
228 acpi_integer * value, u32 function)
229 {
230 acpi_status status;
231 union acpi_operand_object *rgn_desc;
232 u32 region_offset;
233
234 ACPI_FUNCTION_TRACE(ex_access_region);
235
236 /*
237 * Ensure that the region operands are fully evaluated and verify
238 * the validity of the request
239 */
240 status = acpi_ex_setup_region(obj_desc, field_datum_byte_offset);
241 if (ACPI_FAILURE(status)) {
242 return_ACPI_STATUS(status);
243 }
244
245 /*
246 * The physical address of this field datum is:
247 *
248 * 1) The base of the region, plus
249 * 2) The base offset of the field, plus
250 * 3) The current offset into the field
251 */
252 rgn_desc = obj_desc->common_field.region_obj;
253 region_offset =
254 obj_desc->common_field.base_byte_offset + field_datum_byte_offset;
255
256 if ((function & ACPI_IO_MASK) == ACPI_READ) {
257 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[READ]"));
258 } else {
259 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[WRITE]"));
260 }
261
262 ACPI_DEBUG_PRINT_RAW((ACPI_DB_BFIELD,
263 " Region [%s:%X], Width %X, ByteBase %X, Offset %X at %p\n",
264 acpi_ut_get_region_name(rgn_desc->region.
265 space_id),
266 rgn_desc->region.space_id,
267 obj_desc->common_field.access_byte_width,
268 obj_desc->common_field.base_byte_offset,
269 field_datum_byte_offset, ACPI_CAST_PTR(void,
270 (rgn_desc->
271 region.
272 address +
273 region_offset))));
274
275 /* Invoke the appropriate address_space/op_region handler */
276
277 status =
278 acpi_ev_address_space_dispatch(rgn_desc, function, region_offset,
279 ACPI_MUL_8(obj_desc->common_field.
280 access_byte_width),
281 value);
282
283 if (ACPI_FAILURE(status)) {
284 if (status == AE_NOT_IMPLEMENTED) {
285 ACPI_ERROR((AE_INFO,
286 "Region %s(%X) not implemented",
287 acpi_ut_get_region_name(rgn_desc->region.
288 space_id),
289 rgn_desc->region.space_id));
290 } else if (status == AE_NOT_EXIST) {
291 ACPI_ERROR((AE_INFO,
292 "Region %s(%X) has no handler",
293 acpi_ut_get_region_name(rgn_desc->region.
294 space_id),
295 rgn_desc->region.space_id));
296 }
297 }
298
299 return_ACPI_STATUS(status);
300 }
301
302 /*******************************************************************************
303 *
304 * FUNCTION: acpi_ex_register_overflow
305 *
306 * PARAMETERS: obj_desc - Register(Field) to be written
307 * Value - Value to be stored
308 *
309 * RETURN: TRUE if value overflows the field, FALSE otherwise
310 *
311 * DESCRIPTION: Check if a value is out of range of the field being written.
312 * Used to check if the values written to Index and Bank registers
313 * are out of range. Normally, the value is simply truncated
314 * to fit the field, but this case is most likely a serious
315 * coding error in the ASL.
316 *
317 ******************************************************************************/
318
319 static u8
320 acpi_ex_register_overflow(union acpi_operand_object *obj_desc,
321 acpi_integer value)
322 {
323
324 if (obj_desc->common_field.bit_length >= ACPI_INTEGER_BIT_SIZE) {
325 /*
326 * The field is large enough to hold the maximum integer, so we can
327 * never overflow it.
328 */
329 return (FALSE);
330 }
331
332 if (value >= ((acpi_integer) 1 << obj_desc->common_field.bit_length)) {
333 /*
334 * The Value is larger than the maximum value that can fit into
335 * the register.
336 */
337 return (TRUE);
338 }
339
340 /* The Value will fit into the field with no truncation */
341
342 return (FALSE);
343 }
344
345 /*******************************************************************************
346 *
347 * FUNCTION: acpi_ex_field_datum_io
348 *
349 * PARAMETERS: obj_desc - Field to be read
350 * field_datum_byte_offset - Byte offset of this datum within the
351 * parent field
352 * Value - Where to store value (must be 64 bits)
353 * read_write - Read or Write flag
354 *
355 * RETURN: Status
356 *
357 * DESCRIPTION: Read or Write a single datum of a field. The field_type is
358 * demultiplexed here to handle the different types of fields
359 * (buffer_field, region_field, index_field, bank_field)
360 *
361 ******************************************************************************/
362
363 static acpi_status
364 acpi_ex_field_datum_io(union acpi_operand_object *obj_desc,
365 u32 field_datum_byte_offset,
366 acpi_integer * value, u32 read_write)
367 {
368 acpi_status status;
369 acpi_integer local_value;
370
371 ACPI_FUNCTION_TRACE_U32(ex_field_datum_io, field_datum_byte_offset);
372
373 if (read_write == ACPI_READ) {
374 if (!value) {
375 local_value = 0;
376
377 /* To support reads without saving return value */
378 value = &local_value;
379 }
380
381 /* Clear the entire return buffer first, [Very Important!] */
382
383 *value = 0;
384 }
385
386 /*
387 * The four types of fields are:
388 *
389 * buffer_field - Read/write from/to a Buffer
390 * region_field - Read/write from/to a Operation Region.
391 * bank_field - Write to a Bank Register, then read/write from/to an
392 * operation_region
393 * index_field - Write to an Index Register, then read/write from/to a
394 * Data Register
395 */
396 switch (obj_desc->common.type) {
397 case ACPI_TYPE_BUFFER_FIELD:
398 /*
399 * If the buffer_field arguments have not been previously evaluated,
400 * evaluate them now and save the results.
401 */
402 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
403 status = acpi_ds_get_buffer_field_arguments(obj_desc);
404 if (ACPI_FAILURE(status)) {
405 return_ACPI_STATUS(status);
406 }
407 }
408
409 if (read_write == ACPI_READ) {
410 /*
411 * Copy the data from the source buffer.
412 * Length is the field width in bytes.
413 */
414 ACPI_MEMCPY(value,
415 (obj_desc->buffer_field.buffer_obj)->buffer.
416 pointer +
417 obj_desc->buffer_field.base_byte_offset +
418 field_datum_byte_offset,
419 obj_desc->common_field.access_byte_width);
420 } else {
421 /*
422 * Copy the data to the target buffer.
423 * Length is the field width in bytes.
424 */
425 ACPI_MEMCPY((obj_desc->buffer_field.buffer_obj)->buffer.
426 pointer +
427 obj_desc->buffer_field.base_byte_offset +
428 field_datum_byte_offset, value,
429 obj_desc->common_field.access_byte_width);
430 }
431
432 status = AE_OK;
433 break;
434
435 case ACPI_TYPE_LOCAL_BANK_FIELD:
436
437 /*
438 * Ensure that the bank_value is not beyond the capacity of
439 * the register
440 */
441 if (acpi_ex_register_overflow(obj_desc->bank_field.bank_obj,
442 (acpi_integer) obj_desc->
443 bank_field.value)) {
444 return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
445 }
446
447 /*
448 * For bank_fields, we must write the bank_value to the bank_register
449 * (itself a region_field) before we can access the data.
450 */
451 status =
452 acpi_ex_insert_into_field(obj_desc->bank_field.bank_obj,
453 &obj_desc->bank_field.value,
454 sizeof(obj_desc->bank_field.
455 value));
456 if (ACPI_FAILURE(status)) {
457 return_ACPI_STATUS(status);
458 }
459
460 /*
461 * Now that the Bank has been selected, fall through to the
462 * region_field case and write the datum to the Operation Region
463 */
464
465 /*lint -fallthrough */
466
467 case ACPI_TYPE_LOCAL_REGION_FIELD:
468 /*
469 * For simple region_fields, we just directly access the owning
470 * Operation Region.
471 */
472 status =
473 acpi_ex_access_region(obj_desc, field_datum_byte_offset,
474 value, read_write);
475 break;
476
477 case ACPI_TYPE_LOCAL_INDEX_FIELD:
478
479 /*
480 * Ensure that the index_value is not beyond the capacity of
481 * the register
482 */
483 if (acpi_ex_register_overflow(obj_desc->index_field.index_obj,
484 (acpi_integer) obj_desc->
485 index_field.value)) {
486 return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
487 }
488
489 /* Write the index value to the index_register (itself a region_field) */
490
491 field_datum_byte_offset += obj_desc->index_field.value;
492
493 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
494 "Write to Index Register: Value %8.8X\n",
495 field_datum_byte_offset));
496
497 status =
498 acpi_ex_insert_into_field(obj_desc->index_field.index_obj,
499 &field_datum_byte_offset,
500 sizeof(field_datum_byte_offset));
501 if (ACPI_FAILURE(status)) {
502 return_ACPI_STATUS(status);
503 }
504
505 if (read_write == ACPI_READ) {
506
507 /* Read the datum from the data_register */
508
509 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
510 "Read from Data Register\n"));
511
512 status =
513 acpi_ex_extract_from_field(obj_desc->index_field.
514 data_obj, value,
515 sizeof(acpi_integer));
516 } else {
517 /* Write the datum to the data_register */
518
519 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
520 "Write to Data Register: Value %8.8X%8.8X\n",
521 ACPI_FORMAT_UINT64(*value)));
522
523 status =
524 acpi_ex_insert_into_field(obj_desc->index_field.
525 data_obj, value,
526 sizeof(acpi_integer));
527 }
528 break;
529
530 default:
531
532 ACPI_ERROR((AE_INFO, "Wrong object type in field I/O %X",
533 obj_desc->common.type));
534 status = AE_AML_INTERNAL;
535 break;
536 }
537
538 if (ACPI_SUCCESS(status)) {
539 if (read_write == ACPI_READ) {
540 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
541 "Value Read %8.8X%8.8X, Width %d\n",
542 ACPI_FORMAT_UINT64(*value),
543 obj_desc->common_field.
544 access_byte_width));
545 } else {
546 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
547 "Value Written %8.8X%8.8X, Width %d\n",
548 ACPI_FORMAT_UINT64(*value),
549 obj_desc->common_field.
550 access_byte_width));
551 }
552 }
553
554 return_ACPI_STATUS(status);
555 }
556
557 /*******************************************************************************
558 *
559 * FUNCTION: acpi_ex_write_with_update_rule
560 *
561 * PARAMETERS: obj_desc - Field to be written
562 * Mask - bitmask within field datum
563 * field_value - Value to write
564 * field_datum_byte_offset - Offset of datum within field
565 *
566 * RETURN: Status
567 *
568 * DESCRIPTION: Apply the field update rule to a field write
569 *
570 ******************************************************************************/
571
572 acpi_status
573 acpi_ex_write_with_update_rule(union acpi_operand_object *obj_desc,
574 acpi_integer mask,
575 acpi_integer field_value,
576 u32 field_datum_byte_offset)
577 {
578 acpi_status status = AE_OK;
579 acpi_integer merged_value;
580 acpi_integer current_value;
581
582 ACPI_FUNCTION_TRACE_U32(ex_write_with_update_rule, mask);
583
584 /* Start with the new bits */
585
586 merged_value = field_value;
587
588 /* If the mask is all ones, we don't need to worry about the update rule */
589
590 if (mask != ACPI_INTEGER_MAX) {
591
592 /* Decode the update rule */
593
594 switch (obj_desc->common_field.
595 field_flags & AML_FIELD_UPDATE_RULE_MASK) {
596 case AML_FIELD_UPDATE_PRESERVE:
597 /*
598 * Check if update rule needs to be applied (not if mask is all
599 * ones) The left shift drops the bits we want to ignore.
600 */
601 if ((~mask << (ACPI_MUL_8(sizeof(mask)) -
602 ACPI_MUL_8(obj_desc->common_field.
603 access_byte_width))) != 0) {
604 /*
605 * Read the current contents of the byte/word/dword containing
606 * the field, and merge with the new field value.
607 */
608 status =
609 acpi_ex_field_datum_io(obj_desc,
610 field_datum_byte_offset,
611 &current_value,
612 ACPI_READ);
613 if (ACPI_FAILURE(status)) {
614 return_ACPI_STATUS(status);
615 }
616
617 merged_value |= (current_value & ~mask);
618 }
619 break;
620
621 case AML_FIELD_UPDATE_WRITE_AS_ONES:
622
623 /* Set positions outside the field to all ones */
624
625 merged_value |= ~mask;
626 break;
627
628 case AML_FIELD_UPDATE_WRITE_AS_ZEROS:
629
630 /* Set positions outside the field to all zeros */
631
632 merged_value &= mask;
633 break;
634
635 default:
636
637 ACPI_ERROR((AE_INFO,
638 "Unknown UpdateRule value: %X",
639 (obj_desc->common_field.
640 field_flags &
641 AML_FIELD_UPDATE_RULE_MASK)));
642 return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
643 }
644 }
645
646 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
647 "Mask %8.8X%8.8X, DatumOffset %X, Width %X, Value %8.8X%8.8X, MergedValue %8.8X%8.8X\n",
648 ACPI_FORMAT_UINT64(mask),
649 field_datum_byte_offset,
650 obj_desc->common_field.access_byte_width,
651 ACPI_FORMAT_UINT64(field_value),
652 ACPI_FORMAT_UINT64(merged_value)));
653
654 /* Write the merged value */
655
656 status = acpi_ex_field_datum_io(obj_desc, field_datum_byte_offset,
657 &merged_value, ACPI_WRITE);
658
659 return_ACPI_STATUS(status);
660 }
661
662 /*******************************************************************************
663 *
664 * FUNCTION: acpi_ex_extract_from_field
665 *
666 * PARAMETERS: obj_desc - Field to be read
667 * Buffer - Where to store the field data
668 * buffer_length - Length of Buffer
669 *
670 * RETURN: Status
671 *
672 * DESCRIPTION: Retrieve the current value of the given field
673 *
674 ******************************************************************************/
675
676 acpi_status
677 acpi_ex_extract_from_field(union acpi_operand_object *obj_desc,
678 void *buffer, u32 buffer_length)
679 {
680 acpi_status status;
681 acpi_integer raw_datum;
682 acpi_integer merged_datum;
683 u32 field_offset = 0;
684 u32 buffer_offset = 0;
685 u32 buffer_tail_bits;
686 u32 datum_count;
687 u32 field_datum_count;
688 u32 i;
689
690 ACPI_FUNCTION_TRACE(ex_extract_from_field);
691
692 /* Validate target buffer and clear it */
693
694 if (buffer_length <
695 ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length)) {
696 ACPI_ERROR((AE_INFO,
697 "Field size %X (bits) is too large for buffer (%X)",
698 obj_desc->common_field.bit_length, buffer_length));
699
700 return_ACPI_STATUS(AE_BUFFER_OVERFLOW);
701 }
702 ACPI_MEMSET(buffer, 0, buffer_length);
703
704 /* Compute the number of datums (access width data items) */
705
706 datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
707 obj_desc->common_field.access_bit_width);
708 field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
709 obj_desc->common_field.
710 start_field_bit_offset,
711 obj_desc->common_field.
712 access_bit_width);
713
714 /* Priming read from the field */
715
716 status =
717 acpi_ex_field_datum_io(obj_desc, field_offset, &raw_datum,
718 ACPI_READ);
719 if (ACPI_FAILURE(status)) {
720 return_ACPI_STATUS(status);
721 }
722 merged_datum =
723 raw_datum >> obj_desc->common_field.start_field_bit_offset;
724
725 /* Read the rest of the field */
726
727 for (i = 1; i < field_datum_count; i++) {
728
729 /* Get next input datum from the field */
730
731 field_offset += obj_desc->common_field.access_byte_width;
732 status = acpi_ex_field_datum_io(obj_desc, field_offset,
733 &raw_datum, ACPI_READ);
734 if (ACPI_FAILURE(status)) {
735 return_ACPI_STATUS(status);
736 }
737
738 /*
739 * Merge with previous datum if necessary.
740 *
741 * Note: Before the shift, check if the shift value will be larger than
742 * the integer size. If so, there is no need to perform the operation.
743 * This avoids the differences in behavior between different compilers
744 * concerning shift values larger than the target data width.
745 */
746 if ((obj_desc->common_field.access_bit_width -
747 obj_desc->common_field.start_field_bit_offset) <
748 ACPI_INTEGER_BIT_SIZE) {
749 merged_datum |=
750 raw_datum << (obj_desc->common_field.
751 access_bit_width -
752 obj_desc->common_field.
753 start_field_bit_offset);
754 }
755
756 if (i == datum_count) {
757 break;
758 }
759
760 /* Write merged datum to target buffer */
761
762 ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
763 ACPI_MIN(obj_desc->common_field.access_byte_width,
764 buffer_length - buffer_offset));
765
766 buffer_offset += obj_desc->common_field.access_byte_width;
767 merged_datum =
768 raw_datum >> obj_desc->common_field.start_field_bit_offset;
769 }
770
771 /* Mask off any extra bits in the last datum */
772
773 buffer_tail_bits = obj_desc->common_field.bit_length %
774 obj_desc->common_field.access_bit_width;
775 if (buffer_tail_bits) {
776 merged_datum &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
777 }
778
779 /* Write the last datum to the buffer */
780
781 ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
782 ACPI_MIN(obj_desc->common_field.access_byte_width,
783 buffer_length - buffer_offset));
784
785 return_ACPI_STATUS(AE_OK);
786 }
787
788 /*******************************************************************************
789 *
790 * FUNCTION: acpi_ex_insert_into_field
791 *
792 * PARAMETERS: obj_desc - Field to be written
793 * Buffer - Data to be written
794 * buffer_length - Length of Buffer
795 *
796 * RETURN: Status
797 *
798 * DESCRIPTION: Store the Buffer contents into the given field
799 *
800 ******************************************************************************/
801
802 acpi_status
803 acpi_ex_insert_into_field(union acpi_operand_object *obj_desc,
804 void *buffer, u32 buffer_length)
805 {
806 acpi_status status;
807 acpi_integer mask;
808 acpi_integer width_mask;
809 acpi_integer merged_datum;
810 acpi_integer raw_datum = 0;
811 u32 field_offset = 0;
812 u32 buffer_offset = 0;
813 u32 buffer_tail_bits;
814 u32 datum_count;
815 u32 field_datum_count;
816 u32 i;
817 u32 required_length;
818 void *new_buffer;
819
820 ACPI_FUNCTION_TRACE(ex_insert_into_field);
821
822 /* Validate input buffer */
823
824 new_buffer = NULL;
825 required_length =
826 ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length);
827 /*
828 * We must have a buffer that is at least as long as the field
829 * we are writing to. This is because individual fields are
830 * indivisible and partial writes are not supported -- as per
831 * the ACPI specification.
832 */
833 if (buffer_length < required_length) {
834
835 /* We need to create a new buffer */
836
837 new_buffer = ACPI_ALLOCATE_ZEROED(required_length);
838 if (!new_buffer) {
839 return_ACPI_STATUS(AE_NO_MEMORY);
840 }
841
842 /*
843 * Copy the original data to the new buffer, starting
844 * at Byte zero. All unused (upper) bytes of the
845 * buffer will be 0.
846 */
847 ACPI_MEMCPY((char *)new_buffer, (char *)buffer, buffer_length);
848 buffer = new_buffer;
849 buffer_length = required_length;
850 }
851
852 /*
853 * Create the bitmasks used for bit insertion.
854 * Note: This if/else is used to bypass compiler differences with the
855 * shift operator
856 */
857 if (obj_desc->common_field.access_bit_width == ACPI_INTEGER_BIT_SIZE) {
858 width_mask = ACPI_INTEGER_MAX;
859 } else {
860 width_mask =
861 ACPI_MASK_BITS_ABOVE(obj_desc->common_field.
862 access_bit_width);
863 }
864
865 mask = width_mask &
866 ACPI_MASK_BITS_BELOW(obj_desc->common_field.start_field_bit_offset);
867
868 /* Compute the number of datums (access width data items) */
869
870 datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
871 obj_desc->common_field.access_bit_width);
872
873 field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
874 obj_desc->common_field.
875 start_field_bit_offset,
876 obj_desc->common_field.
877 access_bit_width);
878
879 /* Get initial Datum from the input buffer */
880
881 ACPI_MEMCPY(&raw_datum, buffer,
882 ACPI_MIN(obj_desc->common_field.access_byte_width,
883 buffer_length - buffer_offset));
884
885 merged_datum =
886 raw_datum << obj_desc->common_field.start_field_bit_offset;
887
888 /* Write the entire field */
889
890 for (i = 1; i < field_datum_count; i++) {
891
892 /* Write merged datum to the target field */
893
894 merged_datum &= mask;
895 status = acpi_ex_write_with_update_rule(obj_desc, mask,
896 merged_datum,
897 field_offset);
898 if (ACPI_FAILURE(status)) {
899 goto exit;
900 }
901
902 field_offset += obj_desc->common_field.access_byte_width;
903
904 /*
905 * Start new output datum by merging with previous input datum
906 * if necessary.
907 *
908 * Note: Before the shift, check if the shift value will be larger than
909 * the integer size. If so, there is no need to perform the operation.
910 * This avoids the differences in behavior between different compilers
911 * concerning shift values larger than the target data width.
912 */
913 if ((obj_desc->common_field.access_bit_width -
914 obj_desc->common_field.start_field_bit_offset) <
915 ACPI_INTEGER_BIT_SIZE) {
916 merged_datum =
917 raw_datum >> (obj_desc->common_field.
918 access_bit_width -
919 obj_desc->common_field.
920 start_field_bit_offset);
921 } else {
922 merged_datum = 0;
923 }
924
925 mask = width_mask;
926
927 if (i == datum_count) {
928 break;
929 }
930
931 /* Get the next input datum from the buffer */
932
933 buffer_offset += obj_desc->common_field.access_byte_width;
934 ACPI_MEMCPY(&raw_datum, ((char *)buffer) + buffer_offset,
935 ACPI_MIN(obj_desc->common_field.access_byte_width,
936 buffer_length - buffer_offset));
937 merged_datum |=
938 raw_datum << obj_desc->common_field.start_field_bit_offset;
939 }
940
941 /* Mask off any extra bits in the last datum */
942
943 buffer_tail_bits = (obj_desc->common_field.bit_length +
944 obj_desc->common_field.start_field_bit_offset) %
945 obj_desc->common_field.access_bit_width;
946 if (buffer_tail_bits) {
947 mask &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
948 }
949
950 /* Write the last datum to the field */
951
952 merged_datum &= mask;
953 status = acpi_ex_write_with_update_rule(obj_desc,
954 mask, merged_datum,
955 field_offset);
956
957 exit:
958 /* Free temporary buffer if we used one */
959
960 if (new_buffer) {
961 ACPI_FREE(new_buffer);
962 }
963 return_ACPI_STATUS(status);
964 }
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