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