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ACPICA 20050408 from Bob Moore
[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 - 2005, R. Byron Moore
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
45 #include <acpi/acpi.h>
46 #include <acpi/acinterp.h>
47 #include <acpi/amlcode.h>
48 #include <acpi/acevents.h>
49 #include <acpi/acdispat.h>
50
51
52 #define _COMPONENT ACPI_EXECUTER
53 ACPI_MODULE_NAME ("exfldio")
54
55 /* Local prototypes */
56
57 static acpi_status
58 acpi_ex_field_datum_io (
59 union acpi_operand_object *obj_desc,
60 u32 field_datum_byte_offset,
61 acpi_integer *value,
62 u32 read_write);
63
64 static u8
65 acpi_ex_register_overflow (
66 union acpi_operand_object *obj_desc,
67 acpi_integer value);
68
69 static acpi_status
70 acpi_ex_setup_region (
71 union acpi_operand_object *obj_desc,
72 u32 field_datum_byte_offset);
73
74
75 /*******************************************************************************
76 *
77 * FUNCTION: acpi_ex_setup_region
78 *
79 * PARAMETERS: obj_desc - Field to be read or written
80 * field_datum_byte_offset - Byte offset of this datum within the
81 * parent field
82 *
83 * RETURN: Status
84 *
85 * DESCRIPTION: Common processing for acpi_ex_extract_from_field and
86 * acpi_ex_insert_into_field. Initialize the Region if necessary and
87 * validate the request.
88 *
89 ******************************************************************************/
90
91 static acpi_status
92 acpi_ex_setup_region (
93 union acpi_operand_object *obj_desc,
94 u32 field_datum_byte_offset)
95 {
96 acpi_status status = AE_OK;
97 union acpi_operand_object *rgn_desc;
98
99
100 ACPI_FUNCTION_TRACE_U32 ("ex_setup_region", field_datum_byte_offset);
101
102
103 rgn_desc = obj_desc->common_field.region_obj;
104
105 /* We must have a valid region */
106
107 if (ACPI_GET_OBJECT_TYPE (rgn_desc) != ACPI_TYPE_REGION) {
108 ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Needed Region, found type %X (%s)\n",
109 ACPI_GET_OBJECT_TYPE (rgn_desc),
110 acpi_ut_get_object_type_name (rgn_desc)));
111
112 return_ACPI_STATUS (AE_AML_OPERAND_TYPE);
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 if (rgn_desc->region.space_id == ACPI_ADR_SPACE_SMBUS) {
127 /* SMBus has a non-linear address space */
128
129 return_ACPI_STATUS (AE_OK);
130 }
131
132 #ifdef ACPI_UNDER_DEVELOPMENT
133 /*
134 * If the Field access is any_acc, we can now compute the optimal
135 * access (because we know know the length of the parent region)
136 */
137 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
138 if (ACPI_FAILURE (status)) {
139 return_ACPI_STATUS (status);
140 }
141 }
142 #endif
143
144 /*
145 * Validate the request. The entire request from the byte offset for a
146 * length of one field datum (access width) must fit within the region.
147 * (Region length is specified in bytes)
148 */
149 if (rgn_desc->region.length < (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.
157 */
158 if (ACPI_ROUND_UP (rgn_desc->region.length,
159 obj_desc->common_field.access_byte_width) >=
160 (obj_desc->common_field.base_byte_offset +
161 (acpi_native_uint) obj_desc->common_field.access_byte_width +
162 field_datum_byte_offset)) {
163 return_ACPI_STATUS (AE_OK);
164 }
165 }
166
167 if (rgn_desc->region.length < obj_desc->common_field.access_byte_width) {
168 /*
169 * This is the case where the access_type (acc_word, etc.) is wider
170 * than the region itself. For example, a region of length one
171 * byte, and a field with Dword access specified.
172 */
173 ACPI_DEBUG_PRINT ((ACPI_DB_ERROR,
174 "Field [%4.4s] access width (%d bytes) too large for region [%4.4s] (length %X)\n",
175 acpi_ut_get_node_name (obj_desc->common_field.node),
176 obj_desc->common_field.access_byte_width,
177 acpi_ut_get_node_name (rgn_desc->region.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_DEBUG_PRINT ((ACPI_DB_ERROR,
186 "Field [%4.4s] Base+Offset+Width %X+%X+%X is beyond end of region [%4.4s] (length %X)\n",
187 acpi_ut_get_node_name (obj_desc->common_field.node),
188 obj_desc->common_field.base_byte_offset,
189 field_datum_byte_offset, obj_desc->common_field.access_byte_width,
190 acpi_ut_get_node_name (rgn_desc->region.node),
191 rgn_desc->region.length));
192
193 return_ACPI_STATUS (AE_AML_REGION_LIMIT);
194 }
195
196 return_ACPI_STATUS (AE_OK);
197 }
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 (
220 union acpi_operand_object *obj_desc,
221 u32 field_datum_byte_offset,
222 acpi_integer *value,
223 u32 function)
224 {
225 acpi_status status;
226 union acpi_operand_object *rgn_desc;
227 acpi_physical_address address;
228
229
230 ACPI_FUNCTION_TRACE ("ex_access_region");
231
232
233 /*
234 * Ensure that the region operands are fully evaluated and verify
235 * the validity of the request
236 */
237 status = acpi_ex_setup_region (obj_desc, field_datum_byte_offset);
238 if (ACPI_FAILURE (status)) {
239 return_ACPI_STATUS (status);
240 }
241
242 /*
243 * The physical address of this field datum is:
244 *
245 * 1) The base of the region, plus
246 * 2) The base offset of the field, plus
247 * 3) The current offset into the field
248 */
249 rgn_desc = obj_desc->common_field.region_obj;
250 address = rgn_desc->region.address +
251 obj_desc->common_field.base_byte_offset +
252 field_datum_byte_offset;
253
254 if ((function & ACPI_IO_MASK) == ACPI_READ) {
255 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD, "[READ]"));
256 }
257 else {
258 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD, "[WRITE]"));
259 }
260
261 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_BFIELD,
262 " Region [%s:%X], Width %X, byte_base %X, Offset %X at %8.8X%8.8X\n",
263 acpi_ut_get_region_name (rgn_desc->region.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,
268 ACPI_FORMAT_UINT64 (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->common_field.access_byte_width), value);
275
276 if (ACPI_FAILURE (status)) {
277 if (status == AE_NOT_IMPLEMENTED) {
278 ACPI_DEBUG_PRINT ((ACPI_DB_ERROR,
279 "Region %s(%X) not implemented\n",
280 acpi_ut_get_region_name (rgn_desc->region.space_id),
281 rgn_desc->region.space_id));
282 }
283 else if (status == AE_NOT_EXIST) {
284 ACPI_REPORT_ERROR ((
285 "Region %s(%X) has no handler\n",
286 acpi_ut_get_region_name (rgn_desc->region.space_id),
287 rgn_desc->region.space_id));
288 }
289 }
290
291 return_ACPI_STATUS (status);
292 }
293
294
295 /*******************************************************************************
296 *
297 * FUNCTION: acpi_ex_register_overflow
298 *
299 * PARAMETERS: obj_desc - Register(Field) to be written
300 * Value - Value to be stored
301 *
302 * RETURN: TRUE if value overflows the field, FALSE otherwise
303 *
304 * DESCRIPTION: Check if a value is out of range of the field being written.
305 * Used to check if the values written to Index and Bank registers
306 * are out of range. Normally, the value is simply truncated
307 * to fit the field, but this case is most likely a serious
308 * coding error in the ASL.
309 *
310 ******************************************************************************/
311
312 static u8
313 acpi_ex_register_overflow (
314 union acpi_operand_object *obj_desc,
315 acpi_integer value)
316 {
317
318 if (obj_desc->common_field.bit_length >= ACPI_INTEGER_BIT_SIZE) {
319 /*
320 * The field is large enough to hold the maximum integer, so we can
321 * never overflow it.
322 */
323 return (FALSE);
324 }
325
326 if (value >= ((acpi_integer) 1 << obj_desc->common_field.bit_length)) {
327 /*
328 * The Value is larger than the maximum value that can fit into
329 * the register.
330 */
331 return (TRUE);
332 }
333
334 /* The Value will fit into the field with no truncation */
335
336 return (FALSE);
337 }
338
339
340 /*******************************************************************************
341 *
342 * FUNCTION: acpi_ex_field_datum_io
343 *
344 * PARAMETERS: obj_desc - Field to be read
345 * field_datum_byte_offset - Byte offset of this datum within the
346 * parent field
347 * Value - Where to store value (must be 64 bits)
348 * read_write - Read or Write flag
349 *
350 * RETURN: Status
351 *
352 * DESCRIPTION: Read or Write a single datum of a field. The field_type is
353 * demultiplexed here to handle the different types of fields
354 * (buffer_field, region_field, index_field, bank_field)
355 *
356 ******************************************************************************/
357
358 static acpi_status
359 acpi_ex_field_datum_io (
360 union acpi_operand_object *obj_desc,
361 u32 field_datum_byte_offset,
362 acpi_integer *value,
363 u32 read_write)
364 {
365 acpi_status status;
366 acpi_integer local_value;
367
368
369 ACPI_FUNCTION_TRACE_U32 ("ex_field_datum_io", field_datum_byte_offset);
370
371
372 if (read_write == ACPI_READ) {
373 if (!value) {
374 local_value = 0;
375
376 /* To support reads without saving return value */
377 value = &local_value;
378 }
379
380 /* Clear the entire return buffer first, [Very Important!] */
381
382 *value = 0;
383 }
384
385 /*
386 * The four types of fields are:
387 *
388 * buffer_field - Read/write from/to a Buffer
389 * region_field - Read/write from/to a Operation Region.
390 * bank_field - Write to a Bank Register, then read/write from/to an
391 * operation_region
392 * index_field - Write to an Index Register, then read/write from/to a
393 * Data Register
394 */
395 switch (ACPI_GET_OBJECT_TYPE (obj_desc)) {
396 case ACPI_TYPE_BUFFER_FIELD:
397 /*
398 * If the buffer_field arguments have not been previously evaluated,
399 * evaluate them now and save the results.
400 */
401 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
402 status = acpi_ds_get_buffer_field_arguments (obj_desc);
403 if (ACPI_FAILURE (status)) {
404 return_ACPI_STATUS (status);
405 }
406 }
407
408 if (read_write == ACPI_READ) {
409 /*
410 * Copy the data from the source buffer.
411 * Length is the field width in bytes.
412 */
413 ACPI_MEMCPY (value,
414 (obj_desc->buffer_field.buffer_obj)->buffer.pointer +
415 obj_desc->buffer_field.base_byte_offset +
416 field_datum_byte_offset,
417 obj_desc->common_field.access_byte_width);
418 }
419 else {
420 /*
421 * Copy the data to the target buffer.
422 * Length is the field width in bytes.
423 */
424 ACPI_MEMCPY ((obj_desc->buffer_field.buffer_obj)->buffer.pointer +
425 obj_desc->buffer_field.base_byte_offset +
426 field_datum_byte_offset,
427 value, obj_desc->common_field.access_byte_width);
428 }
429
430 status = AE_OK;
431 break;
432
433
434 case ACPI_TYPE_LOCAL_BANK_FIELD:
435
436 /*
437 * Ensure that the bank_value is not beyond the capacity of
438 * the register
439 */
440 if (acpi_ex_register_overflow (obj_desc->bank_field.bank_obj,
441 (acpi_integer) obj_desc->bank_field.value)) {
442 return_ACPI_STATUS (AE_AML_REGISTER_LIMIT);
443 }
444
445 /*
446 * For bank_fields, we must write the bank_value to the bank_register
447 * (itself a region_field) before we can access the data.
448 */
449 status = acpi_ex_insert_into_field (obj_desc->bank_field.bank_obj,
450 &obj_desc->bank_field.value,
451 sizeof (obj_desc->bank_field.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
464 case ACPI_TYPE_LOCAL_REGION_FIELD:
465 /*
466 * For simple region_fields, we just directly access the owning
467 * Operation Region.
468 */
469 status = acpi_ex_access_region (obj_desc, field_datum_byte_offset, value,
470 read_write);
471 break;
472
473
474 case ACPI_TYPE_LOCAL_INDEX_FIELD:
475
476
477 /*
478 * Ensure that the index_value is not beyond the capacity of
479 * the register
480 */
481 if (acpi_ex_register_overflow (obj_desc->index_field.index_obj,
482 (acpi_integer) obj_desc->index_field.value)) {
483 return_ACPI_STATUS (AE_AML_REGISTER_LIMIT);
484 }
485
486 /* Write the index value to the index_register (itself a region_field) */
487
488 field_datum_byte_offset += obj_desc->index_field.value;
489
490 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
491 "Write to Index Register: Value %8.8X\n",
492 field_datum_byte_offset));
493
494 status = 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 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
502 "I/O to Data Register: value_ptr %p\n",
503 value));
504
505 if (read_write == ACPI_READ) {
506 /* Read the datum from the data_register */
507
508 status = acpi_ex_extract_from_field (obj_desc->index_field.data_obj,
509 value, sizeof (acpi_integer));
510 }
511 else {
512 /* Write the datum to the data_register */
513
514 status = acpi_ex_insert_into_field (obj_desc->index_field.data_obj,
515 value, sizeof (acpi_integer));
516 }
517 break;
518
519
520 default:
521
522 ACPI_REPORT_ERROR (("Wrong object type in field I/O %X\n",
523 ACPI_GET_OBJECT_TYPE (obj_desc)));
524 status = AE_AML_INTERNAL;
525 break;
526 }
527
528 if (ACPI_SUCCESS (status)) {
529 if (read_write == ACPI_READ) {
530 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
531 "Value Read %8.8X%8.8X, Width %d\n",
532 ACPI_FORMAT_UINT64 (*value),
533 obj_desc->common_field.access_byte_width));
534 }
535 else {
536 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
537 "Value Written %8.8X%8.8X, Width %d\n",
538 ACPI_FORMAT_UINT64 (*value),
539 obj_desc->common_field.access_byte_width));
540 }
541 }
542
543 return_ACPI_STATUS (status);
544 }
545
546
547 /*******************************************************************************
548 *
549 * FUNCTION: acpi_ex_write_with_update_rule
550 *
551 * PARAMETERS: obj_desc - Field to be written
552 * Mask - bitmask within field datum
553 * field_value - Value to write
554 * field_datum_byte_offset - Offset of datum within field
555 *
556 * RETURN: Status
557 *
558 * DESCRIPTION: Apply the field update rule to a field write
559 *
560 ******************************************************************************/
561
562 acpi_status
563 acpi_ex_write_with_update_rule (
564 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
574 ACPI_FUNCTION_TRACE_U32 ("ex_write_with_update_rule", mask);
575
576
577 /* Start with the new bits */
578
579 merged_value = field_value;
580
581 /* If the mask is all ones, we don't need to worry about the update rule */
582
583 if (mask != ACPI_INTEGER_MAX) {
584 /* Decode the update rule */
585
586 switch (obj_desc->common_field.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.access_byte_width))) != 0) {
594 /*
595 * Read the current contents of the byte/word/dword containing
596 * the field, and merge with the new field value.
597 */
598 status = acpi_ex_field_datum_io (obj_desc, field_datum_byte_offset,
599 &current_value, ACPI_READ);
600 if (ACPI_FAILURE (status)) {
601 return_ACPI_STATUS (status);
602 }
603
604 merged_value |= (current_value & ~mask);
605 }
606 break;
607
608 case AML_FIELD_UPDATE_WRITE_AS_ONES:
609
610 /* Set positions outside the field to all ones */
611
612 merged_value |= ~mask;
613 break;
614
615 case AML_FIELD_UPDATE_WRITE_AS_ZEROS:
616
617 /* Set positions outside the field to all zeros */
618
619 merged_value &= mask;
620 break;
621
622 default:
623
624 ACPI_DEBUG_PRINT ((ACPI_DB_ERROR,
625 "write_with_update_rule: Unknown update_rule setting: %X\n",
626 (obj_desc->common_field.field_flags & AML_FIELD_UPDATE_RULE_MASK)));
627 return_ACPI_STATUS (AE_AML_OPERAND_VALUE);
628 }
629 }
630
631 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
632 "Mask %8.8X%8.8X, datum_offset %X, Width %X, Value %8.8X%8.8X, merged_value %8.8X%8.8X\n",
633 ACPI_FORMAT_UINT64 (mask),
634 field_datum_byte_offset,
635 obj_desc->common_field.access_byte_width,
636 ACPI_FORMAT_UINT64 (field_value),
637 ACPI_FORMAT_UINT64 (merged_value)));
638
639 /* Write the merged value */
640
641 status = acpi_ex_field_datum_io (obj_desc, field_datum_byte_offset,
642 &merged_value, ACPI_WRITE);
643
644 return_ACPI_STATUS (status);
645 }
646
647
648 /*******************************************************************************
649 *
650 * FUNCTION: acpi_ex_extract_from_field
651 *
652 * PARAMETERS: obj_desc - Field to be read
653 * Buffer - Where to store the field data
654 * buffer_length - Length of Buffer
655 *
656 * RETURN: Status
657 *
658 * DESCRIPTION: Retrieve the current value of the given field
659 *
660 ******************************************************************************/
661
662 acpi_status
663 acpi_ex_extract_from_field (
664 union acpi_operand_object *obj_desc,
665 void *buffer,
666 u32 buffer_length)
667 {
668 acpi_status status;
669 acpi_integer raw_datum;
670 acpi_integer merged_datum;
671 u32 field_offset = 0;
672 u32 buffer_offset = 0;
673 u32 buffer_tail_bits;
674 u32 datum_count;
675 u32 field_datum_count;
676 u32 i;
677
678
679 ACPI_FUNCTION_TRACE ("ex_extract_from_field");
680
681
682 /* Validate target buffer and clear it */
683
684 if (buffer_length < ACPI_ROUND_BITS_UP_TO_BYTES (
685 obj_desc->common_field.bit_length)) {
686 ACPI_DEBUG_PRINT ((ACPI_DB_ERROR,
687 "Field size %X (bits) is too large for buffer (%X)\n",
688 obj_desc->common_field.bit_length, buffer_length));
689
690 return_ACPI_STATUS (AE_BUFFER_OVERFLOW);
691 }
692 ACPI_MEMSET (buffer, 0, buffer_length);
693
694 /* Compute the number of datums (access width data items) */
695
696 datum_count = ACPI_ROUND_UP_TO (
697 obj_desc->common_field.bit_length,
698 obj_desc->common_field.access_bit_width);
699 field_datum_count = ACPI_ROUND_UP_TO (
700 obj_desc->common_field.bit_length +
701 obj_desc->common_field.start_field_bit_offset,
702 obj_desc->common_field.access_bit_width);
703
704 /* Priming read from the field */
705
706 status = acpi_ex_field_datum_io (obj_desc, field_offset, &raw_datum, ACPI_READ);
707 if (ACPI_FAILURE (status)) {
708 return_ACPI_STATUS (status);
709 }
710 merged_datum = raw_datum >> obj_desc->common_field.start_field_bit_offset;
711
712 /* Read the rest of the field */
713
714 for (i = 1; i < field_datum_count; i++) {
715 /* Get next input datum from the field */
716
717 field_offset += obj_desc->common_field.access_byte_width;
718 status = acpi_ex_field_datum_io (obj_desc, field_offset,
719 &raw_datum, ACPI_READ);
720 if (ACPI_FAILURE (status)) {
721 return_ACPI_STATUS (status);
722 }
723
724 /* Merge with previous datum if necessary */
725
726 merged_datum |= raw_datum <<
727 (obj_desc->common_field.access_bit_width -
728 obj_desc->common_field.start_field_bit_offset);
729
730 if (i == datum_count) {
731 break;
732 }
733
734 /* Write merged datum to target buffer */
735
736 ACPI_MEMCPY (((char *) buffer) + buffer_offset, &merged_datum,
737 ACPI_MIN(obj_desc->common_field.access_byte_width,
738 buffer_length - buffer_offset));
739
740 buffer_offset += obj_desc->common_field.access_byte_width;
741 merged_datum = raw_datum >> obj_desc->common_field.start_field_bit_offset;
742 }
743
744 /* Mask off any extra bits in the last datum */
745
746 buffer_tail_bits = obj_desc->common_field.bit_length %
747 obj_desc->common_field.access_bit_width;
748 if (buffer_tail_bits) {
749 merged_datum &= ACPI_MASK_BITS_ABOVE (buffer_tail_bits);
750 }
751
752 /* Write the last datum to the buffer */
753
754 ACPI_MEMCPY (((char *) buffer) + buffer_offset, &merged_datum,
755 ACPI_MIN(obj_desc->common_field.access_byte_width,
756 buffer_length - buffer_offset));
757
758 return_ACPI_STATUS (AE_OK);
759 }
760
761
762 /*******************************************************************************
763 *
764 * FUNCTION: acpi_ex_insert_into_field
765 *
766 * PARAMETERS: obj_desc - Field to be written
767 * Buffer - Data to be written
768 * buffer_length - Length of Buffer
769 *
770 * RETURN: Status
771 *
772 * DESCRIPTION: Store the Buffer contents into the given field
773 *
774 ******************************************************************************/
775
776 acpi_status
777 acpi_ex_insert_into_field (
778 union acpi_operand_object *obj_desc,
779 void *buffer,
780 u32 buffer_length)
781 {
782 acpi_status status;
783 acpi_integer mask;
784 acpi_integer merged_datum;
785 acpi_integer raw_datum = 0;
786 u32 field_offset = 0;
787 u32 buffer_offset = 0;
788 u32 buffer_tail_bits;
789 u32 datum_count;
790 u32 field_datum_count;
791 u32 i;
792
793
794 ACPI_FUNCTION_TRACE ("ex_insert_into_field");
795
796
797 /* Validate input buffer */
798
799 if (buffer_length < ACPI_ROUND_BITS_UP_TO_BYTES (
800 obj_desc->common_field.bit_length)) {
801 ACPI_DEBUG_PRINT ((ACPI_DB_ERROR,
802 "Field size %X (bits) is too large for buffer (%X)\n",
803 obj_desc->common_field.bit_length, buffer_length));
804
805 return_ACPI_STATUS (AE_BUFFER_OVERFLOW);
806 }
807
808 /* Compute the number of datums (access width data items) */
809
810 mask = ACPI_MASK_BITS_BELOW (obj_desc->common_field.start_field_bit_offset);
811 datum_count = ACPI_ROUND_UP_TO (obj_desc->common_field.bit_length,
812 obj_desc->common_field.access_bit_width);
813 field_datum_count = ACPI_ROUND_UP_TO (obj_desc->common_field.bit_length +
814 obj_desc->common_field.start_field_bit_offset,
815 obj_desc->common_field.access_bit_width);
816
817 /* Get initial Datum from the input buffer */
818
819 ACPI_MEMCPY (&raw_datum, buffer,
820 ACPI_MIN(obj_desc->common_field.access_byte_width,
821 buffer_length - buffer_offset));
822
823 merged_datum = raw_datum << obj_desc->common_field.start_field_bit_offset;
824
825 /* Write the entire field */
826
827 for (i = 1; i < field_datum_count; i++) {
828 /* Write merged datum to the target field */
829
830 merged_datum &= mask;
831 status = acpi_ex_write_with_update_rule (obj_desc, mask,
832 merged_datum, field_offset);
833 if (ACPI_FAILURE (status)) {
834 return_ACPI_STATUS (status);
835 }
836
837 /* Start new output datum by merging with previous input datum */
838
839 field_offset += obj_desc->common_field.access_byte_width;
840 merged_datum = raw_datum >>
841 (obj_desc->common_field.access_bit_width -
842 obj_desc->common_field.start_field_bit_offset);
843 mask = ACPI_INTEGER_MAX;
844
845 if (i == datum_count) {
846 break;
847 }
848
849 /* Get the next input datum from the buffer */
850
851 buffer_offset += obj_desc->common_field.access_byte_width;
852 ACPI_MEMCPY (&raw_datum, ((char *) buffer) + buffer_offset,
853 ACPI_MIN(obj_desc->common_field.access_byte_width,
854 buffer_length - buffer_offset));
855 merged_datum |= raw_datum << obj_desc->common_field.start_field_bit_offset;
856 }
857
858 /* Mask off any extra bits in the last datum */
859
860 buffer_tail_bits = (obj_desc->common_field.bit_length +
861 obj_desc->common_field.start_field_bit_offset) %
862 obj_desc->common_field.access_bit_width;
863 if (buffer_tail_bits) {
864 mask &= ACPI_MASK_BITS_ABOVE (buffer_tail_bits);
865 }
866
867 /* Write the last datum to the field */
868
869 merged_datum &= mask;
870 status = acpi_ex_write_with_update_rule (obj_desc,
871 mask, merged_datum, field_offset);
872
873 return_ACPI_STATUS (status);
874 }
875
876
Linux kernel - Deliverables
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