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hwmon: (max6650) Add support for alarms
[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 - 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 /*
117 * Exit now for SMBus address space, it has a non-linear address space
118 * and the request cannot be directly validated
119 */
120 if (rgn_desc->region.space_id == ACPI_ADR_SPACE_SMBUS) {
121
122 /* SMBus has a non-linear address space */
123
124 return_ACPI_STATUS(AE_OK);
125 }
126 #ifdef ACPI_UNDER_DEVELOPMENT
127 /*
128 * If the Field access is any_acc, we can now compute the optimal
129 * access (because we know know the length of the parent region)
130 */
131 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
132 if (ACPI_FAILURE(status)) {
133 return_ACPI_STATUS(status);
134 }
135 }
136 #endif
137
138 /*
139 * Validate the request. The entire request from the byte offset for a
140 * length of one field datum (access width) must fit within the region.
141 * (Region length is specified in bytes)
142 */
143 if (rgn_desc->region.length <
144 (obj_desc->common_field.base_byte_offset +
145 field_datum_byte_offset +
146 obj_desc->common_field.access_byte_width)) {
147 if (acpi_gbl_enable_interpreter_slack) {
148 /*
149 * Slack mode only: We will go ahead and allow access to this
150 * field if it is within the region length rounded up to the next
151 * access width boundary. acpi_size cast for 64-bit compile.
152 */
153 if (ACPI_ROUND_UP(rgn_desc->region.length,
154 obj_desc->common_field.
155 access_byte_width) >=
156 ((acpi_size) obj_desc->common_field.
157 base_byte_offset +
158 obj_desc->common_field.access_byte_width +
159 field_datum_byte_offset)) {
160 return_ACPI_STATUS(AE_OK);
161 }
162 }
163
164 if (rgn_desc->region.length <
165 obj_desc->common_field.access_byte_width) {
166 /*
167 * This is the case where the access_type (acc_word, etc.) is wider
168 * than the region itself. For example, a region of length one
169 * byte, and a field with Dword access specified.
170 */
171 ACPI_ERROR((AE_INFO,
172 "Field [%4.4s] access width (%d bytes) too large for region [%4.4s] (length %X)",
173 acpi_ut_get_node_name(obj_desc->
174 common_field.node),
175 obj_desc->common_field.access_byte_width,
176 acpi_ut_get_node_name(rgn_desc->region.
177 node),
178 rgn_desc->region.length));
179 }
180
181 /*
182 * Offset rounded up to next multiple of field width
183 * exceeds region length, indicate an error
184 */
185 ACPI_ERROR((AE_INFO,
186 "Field [%4.4s] Base+Offset+Width %X+%X+%X is beyond end of region [%4.4s] (length %X)",
187 acpi_ut_get_node_name(obj_desc->common_field.node),
188 obj_desc->common_field.base_byte_offset,
189 field_datum_byte_offset,
190 obj_desc->common_field.access_byte_width,
191 acpi_ut_get_node_name(rgn_desc->region.node),
192 rgn_desc->region.length));
193
194 return_ACPI_STATUS(AE_AML_REGION_LIMIT);
195 }
196
197 return_ACPI_STATUS(AE_OK);
198 }
199
200 /*******************************************************************************
201 *
202 * FUNCTION: acpi_ex_access_region
203 *
204 * PARAMETERS: obj_desc - Field to be read
205 * field_datum_byte_offset - Byte offset of this datum within the
206 * parent field
207 * Value - Where to store value (must at least
208 * the size of acpi_integer)
209 * Function - Read or Write flag plus other region-
210 * dependent flags
211 *
212 * RETURN: Status
213 *
214 * DESCRIPTION: Read or Write a single field datum to an Operation Region.
215 *
216 ******************************************************************************/
217
218 acpi_status
219 acpi_ex_access_region(union acpi_operand_object *obj_desc,
220 u32 field_datum_byte_offset,
221 acpi_integer * value, u32 function)
222 {
223 acpi_status status;
224 union acpi_operand_object *rgn_desc;
225 acpi_physical_address address;
226
227 ACPI_FUNCTION_TRACE(ex_access_region);
228
229 /*
230 * Ensure that the region operands are fully evaluated and verify
231 * the validity of the request
232 */
233 status = acpi_ex_setup_region(obj_desc, field_datum_byte_offset);
234 if (ACPI_FAILURE(status)) {
235 return_ACPI_STATUS(status);
236 }
237
238 /*
239 * The physical address of this field datum is:
240 *
241 * 1) The base of the region, plus
242 * 2) The base offset of the field, plus
243 * 3) The current offset into the field
244 */
245 rgn_desc = obj_desc->common_field.region_obj;
246 address = rgn_desc->region.address +
247 obj_desc->common_field.base_byte_offset + field_datum_byte_offset;
248
249 if ((function & ACPI_IO_MASK) == ACPI_READ) {
250 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[READ]"));
251 } else {
252 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[WRITE]"));
253 }
254
255 ACPI_DEBUG_PRINT_RAW((ACPI_DB_BFIELD,
256 " Region [%s:%X], Width %X, ByteBase %X, Offset %X at %p\n",
257 acpi_ut_get_region_name(rgn_desc->region.
258 space_id),
259 rgn_desc->region.space_id,
260 obj_desc->common_field.access_byte_width,
261 obj_desc->common_field.base_byte_offset,
262 field_datum_byte_offset, ACPI_CAST_PTR(void,
263 address)));
264
265 /* Invoke the appropriate address_space/op_region handler */
266
267 status = acpi_ev_address_space_dispatch(rgn_desc, function,
268 address,
269 ACPI_MUL_8(obj_desc->
270 common_field.
271 access_byte_width),
272 value);
273
274 if (ACPI_FAILURE(status)) {
275 if (status == AE_NOT_IMPLEMENTED) {
276 ACPI_ERROR((AE_INFO,
277 "Region %s(%X) not implemented",
278 acpi_ut_get_region_name(rgn_desc->region.
279 space_id),
280 rgn_desc->region.space_id));
281 } else if (status == AE_NOT_EXIST) {
282 ACPI_ERROR((AE_INFO,
283 "Region %s(%X) has no handler",
284 acpi_ut_get_region_name(rgn_desc->region.
285 space_id),
286 rgn_desc->region.space_id));
287 }
288 }
289
290 return_ACPI_STATUS(status);
291 }
292
293 /*******************************************************************************
294 *
295 * FUNCTION: acpi_ex_register_overflow
296 *
297 * PARAMETERS: obj_desc - Register(Field) to be written
298 * Value - Value to be stored
299 *
300 * RETURN: TRUE if value overflows the field, FALSE otherwise
301 *
302 * DESCRIPTION: Check if a value is out of range of the field being written.
303 * Used to check if the values written to Index and Bank registers
304 * are out of range. Normally, the value is simply truncated
305 * to fit the field, but this case is most likely a serious
306 * coding error in the ASL.
307 *
308 ******************************************************************************/
309
310 static u8
311 acpi_ex_register_overflow(union acpi_operand_object *obj_desc,
312 acpi_integer value)
313 {
314
315 if (obj_desc->common_field.bit_length >= ACPI_INTEGER_BIT_SIZE) {
316 /*
317 * The field is large enough to hold the maximum integer, so we can
318 * never overflow it.
319 */
320 return (FALSE);
321 }
322
323 if (value >= ((acpi_integer) 1 << obj_desc->common_field.bit_length)) {
324 /*
325 * The Value is larger than the maximum value that can fit into
326 * the register.
327 */
328 return (TRUE);
329 }
330
331 /* The Value will fit into the field with no truncation */
332
333 return (FALSE);
334 }
335
336 /*******************************************************************************
337 *
338 * FUNCTION: acpi_ex_field_datum_io
339 *
340 * PARAMETERS: obj_desc - Field to be read
341 * field_datum_byte_offset - Byte offset of this datum within the
342 * parent field
343 * Value - Where to store value (must be 64 bits)
344 * read_write - Read or Write flag
345 *
346 * RETURN: Status
347 *
348 * DESCRIPTION: Read or Write a single datum of a field. The field_type is
349 * demultiplexed here to handle the different types of fields
350 * (buffer_field, region_field, index_field, bank_field)
351 *
352 ******************************************************************************/
353
354 static acpi_status
355 acpi_ex_field_datum_io(union acpi_operand_object *obj_desc,
356 u32 field_datum_byte_offset,
357 acpi_integer * value, u32 read_write)
358 {
359 acpi_status status;
360 acpi_integer local_value;
361
362 ACPI_FUNCTION_TRACE_U32(ex_field_datum_io, field_datum_byte_offset);
363
364 if (read_write == ACPI_READ) {
365 if (!value) {
366 local_value = 0;
367
368 /* To support reads without saving return value */
369 value = &local_value;
370 }
371
372 /* Clear the entire return buffer first, [Very Important!] */
373
374 *value = 0;
375 }
376
377 /*
378 * The four types of fields are:
379 *
380 * buffer_field - Read/write from/to a Buffer
381 * region_field - Read/write from/to a Operation Region.
382 * bank_field - Write to a Bank Register, then read/write from/to an
383 * operation_region
384 * index_field - Write to an Index Register, then read/write from/to a
385 * Data Register
386 */
387 switch (obj_desc->common.type) {
388 case ACPI_TYPE_BUFFER_FIELD:
389 /*
390 * If the buffer_field arguments have not been previously evaluated,
391 * evaluate them now and save the results.
392 */
393 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
394 status = acpi_ds_get_buffer_field_arguments(obj_desc);
395 if (ACPI_FAILURE(status)) {
396 return_ACPI_STATUS(status);
397 }
398 }
399
400 if (read_write == ACPI_READ) {
401 /*
402 * Copy the data from the source buffer.
403 * Length is the field width in bytes.
404 */
405 ACPI_MEMCPY(value,
406 (obj_desc->buffer_field.buffer_obj)->buffer.
407 pointer +
408 obj_desc->buffer_field.base_byte_offset +
409 field_datum_byte_offset,
410 obj_desc->common_field.access_byte_width);
411 } else {
412 /*
413 * Copy the data to the target buffer.
414 * Length is the field width in bytes.
415 */
416 ACPI_MEMCPY((obj_desc->buffer_field.buffer_obj)->buffer.
417 pointer +
418 obj_desc->buffer_field.base_byte_offset +
419 field_datum_byte_offset, value,
420 obj_desc->common_field.access_byte_width);
421 }
422
423 status = AE_OK;
424 break;
425
426 case ACPI_TYPE_LOCAL_BANK_FIELD:
427
428 /*
429 * Ensure that the bank_value is not beyond the capacity of
430 * the register
431 */
432 if (acpi_ex_register_overflow(obj_desc->bank_field.bank_obj,
433 (acpi_integer) obj_desc->
434 bank_field.value)) {
435 return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
436 }
437
438 /*
439 * For bank_fields, we must write the bank_value to the bank_register
440 * (itself a region_field) before we can access the data.
441 */
442 status =
443 acpi_ex_insert_into_field(obj_desc->bank_field.bank_obj,
444 &obj_desc->bank_field.value,
445 sizeof(obj_desc->bank_field.
446 value));
447 if (ACPI_FAILURE(status)) {
448 return_ACPI_STATUS(status);
449 }
450
451 /*
452 * Now that the Bank has been selected, fall through to the
453 * region_field case and write the datum to the Operation Region
454 */
455
456 /*lint -fallthrough */
457
458 case ACPI_TYPE_LOCAL_REGION_FIELD:
459 /*
460 * For simple region_fields, we just directly access the owning
461 * Operation Region.
462 */
463 status =
464 acpi_ex_access_region(obj_desc, field_datum_byte_offset,
465 value, read_write);
466 break;
467
468 case ACPI_TYPE_LOCAL_INDEX_FIELD:
469
470 /*
471 * Ensure that the index_value is not beyond the capacity of
472 * the register
473 */
474 if (acpi_ex_register_overflow(obj_desc->index_field.index_obj,
475 (acpi_integer) obj_desc->
476 index_field.value)) {
477 return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
478 }
479
480 /* Write the index value to the index_register (itself a region_field) */
481
482 field_datum_byte_offset += obj_desc->index_field.value;
483
484 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
485 "Write to Index Register: Value %8.8X\n",
486 field_datum_byte_offset));
487
488 status =
489 acpi_ex_insert_into_field(obj_desc->index_field.index_obj,
490 &field_datum_byte_offset,
491 sizeof(field_datum_byte_offset));
492 if (ACPI_FAILURE(status)) {
493 return_ACPI_STATUS(status);
494 }
495
496 if (read_write == ACPI_READ) {
497
498 /* Read the datum from the data_register */
499
500 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
501 "Read from Data Register\n"));
502
503 status =
504 acpi_ex_extract_from_field(obj_desc->index_field.
505 data_obj, value,
506 sizeof(acpi_integer));
507 } else {
508 /* Write the datum to the data_register */
509
510 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
511 "Write to Data Register: Value %8.8X%8.8X\n",
512 ACPI_FORMAT_UINT64(*value)));
513
514 status =
515 acpi_ex_insert_into_field(obj_desc->index_field.
516 data_obj, value,
517 sizeof(acpi_integer));
518 }
519 break;
520
521 default:
522
523 ACPI_ERROR((AE_INFO, "Wrong object type in field I/O %X",
524 obj_desc->common.type));
525 status = AE_AML_INTERNAL;
526 break;
527 }
528
529 if (ACPI_SUCCESS(status)) {
530 if (read_write == ACPI_READ) {
531 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
532 "Value Read %8.8X%8.8X, Width %d\n",
533 ACPI_FORMAT_UINT64(*value),
534 obj_desc->common_field.
535 access_byte_width));
536 } else {
537 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
538 "Value Written %8.8X%8.8X, Width %d\n",
539 ACPI_FORMAT_UINT64(*value),
540 obj_desc->common_field.
541 access_byte_width));
542 }
543 }
544
545 return_ACPI_STATUS(status);
546 }
547
548 /*******************************************************************************
549 *
550 * FUNCTION: acpi_ex_write_with_update_rule
551 *
552 * PARAMETERS: obj_desc - Field to be written
553 * Mask - bitmask within field datum
554 * field_value - Value to write
555 * field_datum_byte_offset - Offset of datum within field
556 *
557 * RETURN: Status
558 *
559 * DESCRIPTION: Apply the field update rule to a field write
560 *
561 ******************************************************************************/
562
563 acpi_status
564 acpi_ex_write_with_update_rule(union acpi_operand_object *obj_desc,
565 acpi_integer mask,
566 acpi_integer field_value,
567 u32 field_datum_byte_offset)
568 {
569 acpi_status status = AE_OK;
570 acpi_integer merged_value;
571 acpi_integer current_value;
572
573 ACPI_FUNCTION_TRACE_U32(ex_write_with_update_rule, mask);
574
575 /* Start with the new bits */
576
577 merged_value = field_value;
578
579 /* If the mask is all ones, we don't need to worry about the update rule */
580
581 if (mask != ACPI_INTEGER_MAX) {
582
583 /* Decode the update rule */
584
585 switch (obj_desc->common_field.
586 field_flags & AML_FIELD_UPDATE_RULE_MASK) {
587 case AML_FIELD_UPDATE_PRESERVE:
588 /*
589 * Check if update rule needs to be applied (not if mask is all
590 * ones) The left shift drops the bits we want to ignore.
591 */
592 if ((~mask << (ACPI_MUL_8(sizeof(mask)) -
593 ACPI_MUL_8(obj_desc->common_field.
594 access_byte_width))) != 0) {
595 /*
596 * Read the current contents of the byte/word/dword containing
597 * the field, and merge with the new field value.
598 */
599 status =
600 acpi_ex_field_datum_io(obj_desc,
601 field_datum_byte_offset,
602 &current_value,
603 ACPI_READ);
604 if (ACPI_FAILURE(status)) {
605 return_ACPI_STATUS(status);
606 }
607
608 merged_value |= (current_value & ~mask);
609 }
610 break;
611
612 case AML_FIELD_UPDATE_WRITE_AS_ONES:
613
614 /* Set positions outside the field to all ones */
615
616 merged_value |= ~mask;
617 break;
618
619 case AML_FIELD_UPDATE_WRITE_AS_ZEROS:
620
621 /* Set positions outside the field to all zeros */
622
623 merged_value &= mask;
624 break;
625
626 default:
627
628 ACPI_ERROR((AE_INFO,
629 "Unknown UpdateRule value: %X",
630 (obj_desc->common_field.
631 field_flags &
632 AML_FIELD_UPDATE_RULE_MASK)));
633 return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
634 }
635 }
636
637 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
638 "Mask %8.8X%8.8X, DatumOffset %X, Width %X, Value %8.8X%8.8X, MergedValue %8.8X%8.8X\n",
639 ACPI_FORMAT_UINT64(mask),
640 field_datum_byte_offset,
641 obj_desc->common_field.access_byte_width,
642 ACPI_FORMAT_UINT64(field_value),
643 ACPI_FORMAT_UINT64(merged_value)));
644
645 /* Write the merged value */
646
647 status = acpi_ex_field_datum_io(obj_desc, field_datum_byte_offset,
648 &merged_value, ACPI_WRITE);
649
650 return_ACPI_STATUS(status);
651 }
652
653 /*******************************************************************************
654 *
655 * FUNCTION: acpi_ex_extract_from_field
656 *
657 * PARAMETERS: obj_desc - Field to be read
658 * Buffer - Where to store the field data
659 * buffer_length - Length of Buffer
660 *
661 * RETURN: Status
662 *
663 * DESCRIPTION: Retrieve the current value of the given field
664 *
665 ******************************************************************************/
666
667 acpi_status
668 acpi_ex_extract_from_field(union acpi_operand_object *obj_desc,
669 void *buffer, u32 buffer_length)
670 {
671 acpi_status status;
672 acpi_integer raw_datum;
673 acpi_integer merged_datum;
674 u32 field_offset = 0;
675 u32 buffer_offset = 0;
676 u32 buffer_tail_bits;
677 u32 datum_count;
678 u32 field_datum_count;
679 u32 i;
680
681 ACPI_FUNCTION_TRACE(ex_extract_from_field);
682
683 /* Validate target buffer and clear it */
684
685 if (buffer_length <
686 ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length)) {
687 ACPI_ERROR((AE_INFO,
688 "Field size %X (bits) is too large for buffer (%X)",
689 obj_desc->common_field.bit_length, buffer_length));
690
691 return_ACPI_STATUS(AE_BUFFER_OVERFLOW);
692 }
693 ACPI_MEMSET(buffer, 0, buffer_length);
694
695 /* Compute the number of datums (access width data items) */
696
697 datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
698 obj_desc->common_field.access_bit_width);
699 field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
700 obj_desc->common_field.
701 start_field_bit_offset,
702 obj_desc->common_field.
703 access_bit_width);
704
705 /* Priming read from the field */
706
707 status =
708 acpi_ex_field_datum_io(obj_desc, field_offset, &raw_datum,
709 ACPI_READ);
710 if (ACPI_FAILURE(status)) {
711 return_ACPI_STATUS(status);
712 }
713 merged_datum =
714 raw_datum >> obj_desc->common_field.start_field_bit_offset;
715
716 /* Read the rest of the field */
717
718 for (i = 1; i < field_datum_count; i++) {
719
720 /* Get next input datum from the field */
721
722 field_offset += obj_desc->common_field.access_byte_width;
723 status = acpi_ex_field_datum_io(obj_desc, field_offset,
724 &raw_datum, ACPI_READ);
725 if (ACPI_FAILURE(status)) {
726 return_ACPI_STATUS(status);
727 }
728
729 /*
730 * Merge with previous datum if necessary.
731 *
732 * Note: Before the shift, check if the shift value will be larger than
733 * the integer size. If so, there is no need to perform the operation.
734 * This avoids the differences in behavior between different compilers
735 * concerning shift values larger than the target data width.
736 */
737 if ((obj_desc->common_field.access_bit_width -
738 obj_desc->common_field.start_field_bit_offset) <
739 ACPI_INTEGER_BIT_SIZE) {
740 merged_datum |=
741 raw_datum << (obj_desc->common_field.
742 access_bit_width -
743 obj_desc->common_field.
744 start_field_bit_offset);
745 }
746
747 if (i == datum_count) {
748 break;
749 }
750
751 /* Write merged datum to target buffer */
752
753 ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
754 ACPI_MIN(obj_desc->common_field.access_byte_width,
755 buffer_length - buffer_offset));
756
757 buffer_offset += obj_desc->common_field.access_byte_width;
758 merged_datum =
759 raw_datum >> obj_desc->common_field.start_field_bit_offset;
760 }
761
762 /* Mask off any extra bits in the last datum */
763
764 buffer_tail_bits = obj_desc->common_field.bit_length %
765 obj_desc->common_field.access_bit_width;
766 if (buffer_tail_bits) {
767 merged_datum &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
768 }
769
770 /* Write the last datum to the buffer */
771
772 ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
773 ACPI_MIN(obj_desc->common_field.access_byte_width,
774 buffer_length - buffer_offset));
775
776 return_ACPI_STATUS(AE_OK);
777 }
778
779 /*******************************************************************************
780 *
781 * FUNCTION: acpi_ex_insert_into_field
782 *
783 * PARAMETERS: obj_desc - Field to be written
784 * Buffer - Data to be written
785 * buffer_length - Length of Buffer
786 *
787 * RETURN: Status
788 *
789 * DESCRIPTION: Store the Buffer contents into the given field
790 *
791 ******************************************************************************/
792
793 acpi_status
794 acpi_ex_insert_into_field(union acpi_operand_object *obj_desc,
795 void *buffer, u32 buffer_length)
796 {
797 acpi_status status;
798 acpi_integer mask;
799 acpi_integer width_mask;
800 acpi_integer merged_datum;
801 acpi_integer raw_datum = 0;
802 u32 field_offset = 0;
803 u32 buffer_offset = 0;
804 u32 buffer_tail_bits;
805 u32 datum_count;
806 u32 field_datum_count;
807 u32 i;
808 u32 required_length;
809 void *new_buffer;
810
811 ACPI_FUNCTION_TRACE(ex_insert_into_field);
812
813 /* Validate input buffer */
814
815 new_buffer = NULL;
816 required_length =
817 ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length);
818 /*
819 * We must have a buffer that is at least as long as the field
820 * we are writing to. This is because individual fields are
821 * indivisible and partial writes are not supported -- as per
822 * the ACPI specification.
823 */
824 if (buffer_length < required_length) {
825
826 /* We need to create a new buffer */
827
828 new_buffer = ACPI_ALLOCATE_ZEROED(required_length);
829 if (!new_buffer) {
830 return_ACPI_STATUS(AE_NO_MEMORY);
831 }
832
833 /*
834 * Copy the original data to the new buffer, starting
835 * at Byte zero. All unused (upper) bytes of the
836 * buffer will be 0.
837 */
838 ACPI_MEMCPY((char *)new_buffer, (char *)buffer, buffer_length);
839 buffer = new_buffer;
840 buffer_length = required_length;
841 }
842
843 /*
844 * Create the bitmasks used for bit insertion.
845 * Note: This if/else is used to bypass compiler differences with the
846 * shift operator
847 */
848 if (obj_desc->common_field.access_bit_width == ACPI_INTEGER_BIT_SIZE) {
849 width_mask = ACPI_INTEGER_MAX;
850 } else {
851 width_mask =
852 ACPI_MASK_BITS_ABOVE(obj_desc->common_field.
853 access_bit_width);
854 }
855
856 mask = width_mask &
857 ACPI_MASK_BITS_BELOW(obj_desc->common_field.start_field_bit_offset);
858
859 /* Compute the number of datums (access width data items) */
860
861 datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
862 obj_desc->common_field.access_bit_width);
863
864 field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
865 obj_desc->common_field.
866 start_field_bit_offset,
867 obj_desc->common_field.
868 access_bit_width);
869
870 /* Get initial Datum from the input buffer */
871
872 ACPI_MEMCPY(&raw_datum, buffer,
873 ACPI_MIN(obj_desc->common_field.access_byte_width,
874 buffer_length - buffer_offset));
875
876 merged_datum =
877 raw_datum << obj_desc->common_field.start_field_bit_offset;
878
879 /* Write the entire field */
880
881 for (i = 1; i < field_datum_count; i++) {
882
883 /* Write merged datum to the target field */
884
885 merged_datum &= mask;
886 status = acpi_ex_write_with_update_rule(obj_desc, mask,
887 merged_datum,
888 field_offset);
889 if (ACPI_FAILURE(status)) {
890 goto exit;
891 }
892
893 field_offset += obj_desc->common_field.access_byte_width;
894
895 /*
896 * Start new output datum by merging with previous input datum
897 * if necessary.
898 *
899 * Note: Before the shift, check if the shift value will be larger than
900 * the integer size. If so, there is no need to perform the operation.
901 * This avoids the differences in behavior between different compilers
902 * concerning shift values larger than the target data width.
903 */
904 if ((obj_desc->common_field.access_bit_width -
905 obj_desc->common_field.start_field_bit_offset) <
906 ACPI_INTEGER_BIT_SIZE) {
907 merged_datum =
908 raw_datum >> (obj_desc->common_field.
909 access_bit_width -
910 obj_desc->common_field.
911 start_field_bit_offset);
912 } else {
913 merged_datum = 0;
914 }
915
916 mask = width_mask;
917
918 if (i == datum_count) {
919 break;
920 }
921
922 /* Get the next input datum from the buffer */
923
924 buffer_offset += obj_desc->common_field.access_byte_width;
925 ACPI_MEMCPY(&raw_datum, ((char *)buffer) + buffer_offset,
926 ACPI_MIN(obj_desc->common_field.access_byte_width,
927 buffer_length - buffer_offset));
928 merged_datum |=
929 raw_datum << obj_desc->common_field.start_field_bit_offset;
930 }
931
932 /* Mask off any extra bits in the last datum */
933
934 buffer_tail_bits = (obj_desc->common_field.bit_length +
935 obj_desc->common_field.start_field_bit_offset) %
936 obj_desc->common_field.access_bit_width;
937 if (buffer_tail_bits) {
938 mask &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
939 }
940
941 /* Write the last datum to the field */
942
943 merged_datum &= mask;
944 status = acpi_ex_write_with_update_rule(obj_desc,
945 mask, merged_datum,
946 field_offset);
947
948 exit:
949 /* Free temporary buffer if we used one */
950
951 if (new_buffer) {
952 ACPI_FREE(new_buffer);
953 }
954 return_ACPI_STATUS(status);
955 }
Linux kernel - Deliverables
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