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Merge commit 'v2.6.39-rc6' into x86/cleanups
[mirror_ubuntu-artful-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 - 2011, 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 u64 *value, u32 read_write);
59
60 static u8
61 acpi_ex_register_overflow(union acpi_operand_object *obj_desc, u64 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 (rgn_desc->common.type != ACPI_TYPE_REGION) {
97 ACPI_ERROR((AE_INFO, "Needed Region, found type 0x%X (%s)",
98 rgn_desc->common.type,
99 acpi_ut_get_object_type_name(rgn_desc)));
100
101 return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
102 }
103
104 /*
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 or IPMI address space, it has a non-linear
123 * address space and the request cannot be directly validated
124 */
125 if (rgn_desc->region.space_id == ACPI_ADR_SPACE_SMBUS ||
126 rgn_desc->region.space_id == ACPI_ADR_SPACE_IPMI) {
127
128 /* SMBus or IPMI has a non-linear address space */
129
130 return_ACPI_STATUS(AE_OK);
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 <
150 (obj_desc->common_field.base_byte_offset + 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 (%u bytes) too large for region [%4.4s] (length %u)",
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 %u+%u+%u is beyond end of region [%4.4s] (length %u)",
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 * 64 bits)
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, u64 *value, u32 function)
226 {
227 acpi_status status;
228 union acpi_operand_object *rgn_desc;
229 u32 region_offset;
230
231 ACPI_FUNCTION_TRACE(ex_access_region);
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 region_offset =
251 obj_desc->common_field.base_byte_offset + field_datum_byte_offset;
252
253 if ((function & ACPI_IO_MASK) == ACPI_READ) {
254 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[READ]"));
255 } else {
256 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[WRITE]"));
257 }
258
259 ACPI_DEBUG_PRINT_RAW((ACPI_DB_BFIELD,
260 " Region [%s:%X], Width %X, ByteBase %X, Offset %X at %p\n",
261 acpi_ut_get_region_name(rgn_desc->region.
262 space_id),
263 rgn_desc->region.space_id,
264 obj_desc->common_field.access_byte_width,
265 obj_desc->common_field.base_byte_offset,
266 field_datum_byte_offset, ACPI_CAST_PTR(void,
267 (rgn_desc->
268 region.
269 address +
270 region_offset))));
271
272 /* Invoke the appropriate address_space/op_region handler */
273
274 status =
275 acpi_ev_address_space_dispatch(rgn_desc, function, region_offset,
276 ACPI_MUL_8(obj_desc->common_field.
277 access_byte_width),
278 value);
279
280 if (ACPI_FAILURE(status)) {
281 if (status == AE_NOT_IMPLEMENTED) {
282 ACPI_ERROR((AE_INFO,
283 "Region %s (ID=%u) not implemented",
284 acpi_ut_get_region_name(rgn_desc->region.
285 space_id),
286 rgn_desc->region.space_id));
287 } else if (status == AE_NOT_EXIST) {
288 ACPI_ERROR((AE_INFO,
289 "Region %s (ID=%u) has no handler",
290 acpi_ut_get_region_name(rgn_desc->region.
291 space_id),
292 rgn_desc->region.space_id));
293 }
294 }
295
296 return_ACPI_STATUS(status);
297 }
298
299 /*******************************************************************************
300 *
301 * FUNCTION: acpi_ex_register_overflow
302 *
303 * PARAMETERS: obj_desc - Register(Field) to be written
304 * Value - Value to be stored
305 *
306 * RETURN: TRUE if value overflows the field, FALSE otherwise
307 *
308 * DESCRIPTION: Check if a value is out of range of the field being written.
309 * Used to check if the values written to Index and Bank registers
310 * are out of range. Normally, the value is simply truncated
311 * to fit the field, but this case is most likely a serious
312 * coding error in the ASL.
313 *
314 ******************************************************************************/
315
316 static u8
317 acpi_ex_register_overflow(union acpi_operand_object *obj_desc, u64 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 >= ((u64) 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, u64 *value, u32 read_write)
362 {
363 acpi_status status;
364 u64 local_value;
365
366 ACPI_FUNCTION_TRACE_U32(ex_field_datum_io, field_datum_byte_offset);
367
368 if (read_write == ACPI_READ) {
369 if (!value) {
370 local_value = 0;
371
372 /* To support reads without saving return value */
373 value = &local_value;
374 }
375
376 /* Clear the entire return buffer first, [Very Important!] */
377
378 *value = 0;
379 }
380
381 /*
382 * The four types of fields are:
383 *
384 * buffer_field - Read/write from/to a Buffer
385 * region_field - Read/write from/to a Operation Region.
386 * bank_field - Write to a Bank Register, then read/write from/to an
387 * operation_region
388 * index_field - Write to an Index Register, then read/write from/to a
389 * Data Register
390 */
391 switch (obj_desc->common.type) {
392 case ACPI_TYPE_BUFFER_FIELD:
393 /*
394 * If the buffer_field arguments have not been previously evaluated,
395 * evaluate them now and save the results.
396 */
397 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
398 status = acpi_ds_get_buffer_field_arguments(obj_desc);
399 if (ACPI_FAILURE(status)) {
400 return_ACPI_STATUS(status);
401 }
402 }
403
404 if (read_write == ACPI_READ) {
405 /*
406 * Copy the data from the source buffer.
407 * Length is the field width in bytes.
408 */
409 ACPI_MEMCPY(value,
410 (obj_desc->buffer_field.buffer_obj)->buffer.
411 pointer +
412 obj_desc->buffer_field.base_byte_offset +
413 field_datum_byte_offset,
414 obj_desc->common_field.access_byte_width);
415 } else {
416 /*
417 * Copy the data to the target buffer.
418 * Length is the field width in bytes.
419 */
420 ACPI_MEMCPY((obj_desc->buffer_field.buffer_obj)->buffer.
421 pointer +
422 obj_desc->buffer_field.base_byte_offset +
423 field_datum_byte_offset, value,
424 obj_desc->common_field.access_byte_width);
425 }
426
427 status = AE_OK;
428 break;
429
430 case ACPI_TYPE_LOCAL_BANK_FIELD:
431
432 /*
433 * Ensure that the bank_value is not beyond the capacity of
434 * the register
435 */
436 if (acpi_ex_register_overflow(obj_desc->bank_field.bank_obj,
437 (u64) obj_desc->bank_field.
438 value)) {
439 return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
440 }
441
442 /*
443 * For bank_fields, we must write the bank_value to the bank_register
444 * (itself a region_field) before we can access the data.
445 */
446 status =
447 acpi_ex_insert_into_field(obj_desc->bank_field.bank_obj,
448 &obj_desc->bank_field.value,
449 sizeof(obj_desc->bank_field.
450 value));
451 if (ACPI_FAILURE(status)) {
452 return_ACPI_STATUS(status);
453 }
454
455 /*
456 * Now that the Bank has been selected, fall through to the
457 * region_field case and write the datum to the Operation Region
458 */
459
460 /*lint -fallthrough */
461
462 case ACPI_TYPE_LOCAL_REGION_FIELD:
463 /*
464 * For simple region_fields, we just directly access the owning
465 * Operation Region.
466 */
467 status =
468 acpi_ex_access_region(obj_desc, field_datum_byte_offset,
469 value, read_write);
470 break;
471
472 case ACPI_TYPE_LOCAL_INDEX_FIELD:
473
474 /*
475 * Ensure that the index_value is not beyond the capacity of
476 * the register
477 */
478 if (acpi_ex_register_overflow(obj_desc->index_field.index_obj,
479 (u64) obj_desc->index_field.
480 value)) {
481 return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
482 }
483
484 /* Write the index value to the index_register (itself a region_field) */
485
486 field_datum_byte_offset += obj_desc->index_field.value;
487
488 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
489 "Write to Index Register: Value %8.8X\n",
490 field_datum_byte_offset));
491
492 status =
493 acpi_ex_insert_into_field(obj_desc->index_field.index_obj,
494 &field_datum_byte_offset,
495 sizeof(field_datum_byte_offset));
496 if (ACPI_FAILURE(status)) {
497 return_ACPI_STATUS(status);
498 }
499
500 if (read_write == ACPI_READ) {
501
502 /* Read the datum from the data_register */
503
504 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
505 "Read from Data Register\n"));
506
507 status =
508 acpi_ex_extract_from_field(obj_desc->index_field.
509 data_obj, value,
510 sizeof(u64));
511 } else {
512 /* Write the datum to the data_register */
513
514 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
515 "Write to Data Register: Value %8.8X%8.8X\n",
516 ACPI_FORMAT_UINT64(*value)));
517
518 status =
519 acpi_ex_insert_into_field(obj_desc->index_field.
520 data_obj, value,
521 sizeof(u64));
522 }
523 break;
524
525 default:
526
527 ACPI_ERROR((AE_INFO, "Wrong object type in field I/O %u",
528 obj_desc->common.type));
529 status = AE_AML_INTERNAL;
530 break;
531 }
532
533 if (ACPI_SUCCESS(status)) {
534 if (read_write == ACPI_READ) {
535 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
536 "Value Read %8.8X%8.8X, Width %u\n",
537 ACPI_FORMAT_UINT64(*value),
538 obj_desc->common_field.
539 access_byte_width));
540 } else {
541 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
542 "Value Written %8.8X%8.8X, Width %u\n",
543 ACPI_FORMAT_UINT64(*value),
544 obj_desc->common_field.
545 access_byte_width));
546 }
547 }
548
549 return_ACPI_STATUS(status);
550 }
551
552 /*******************************************************************************
553 *
554 * FUNCTION: acpi_ex_write_with_update_rule
555 *
556 * PARAMETERS: obj_desc - Field to be written
557 * Mask - bitmask within field datum
558 * field_value - Value to write
559 * field_datum_byte_offset - Offset of datum within field
560 *
561 * RETURN: Status
562 *
563 * DESCRIPTION: Apply the field update rule to a field write
564 *
565 ******************************************************************************/
566
567 acpi_status
568 acpi_ex_write_with_update_rule(union acpi_operand_object *obj_desc,
569 u64 mask,
570 u64 field_value, u32 field_datum_byte_offset)
571 {
572 acpi_status status = AE_OK;
573 u64 merged_value;
574 u64 current_value;
575
576 ACPI_FUNCTION_TRACE_U32(ex_write_with_update_rule, mask);
577
578 /* Start with the new bits */
579
580 merged_value = field_value;
581
582 /* If the mask is all ones, we don't need to worry about the update rule */
583
584 if (mask != ACPI_UINT64_MAX) {
585
586 /* Decode the update rule */
587
588 switch (obj_desc->common_field.
589 field_flags & AML_FIELD_UPDATE_RULE_MASK) {
590 case AML_FIELD_UPDATE_PRESERVE:
591 /*
592 * Check if update rule needs to be applied (not if mask is all
593 * ones) The left shift drops the bits we want to ignore.
594 */
595 if ((~mask << (ACPI_MUL_8(sizeof(mask)) -
596 ACPI_MUL_8(obj_desc->common_field.
597 access_byte_width))) != 0) {
598 /*
599 * Read the current contents of the byte/word/dword containing
600 * the field, and merge with the new field value.
601 */
602 status =
603 acpi_ex_field_datum_io(obj_desc,
604 field_datum_byte_offset,
605 &current_value,
606 ACPI_READ);
607 if (ACPI_FAILURE(status)) {
608 return_ACPI_STATUS(status);
609 }
610
611 merged_value |= (current_value & ~mask);
612 }
613 break;
614
615 case AML_FIELD_UPDATE_WRITE_AS_ONES:
616
617 /* Set positions outside the field to all ones */
618
619 merged_value |= ~mask;
620 break;
621
622 case AML_FIELD_UPDATE_WRITE_AS_ZEROS:
623
624 /* Set positions outside the field to all zeros */
625
626 merged_value &= mask;
627 break;
628
629 default:
630
631 ACPI_ERROR((AE_INFO,
632 "Unknown UpdateRule value: 0x%X",
633 (obj_desc->common_field.
634 field_flags &
635 AML_FIELD_UPDATE_RULE_MASK)));
636 return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
637 }
638 }
639
640 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
641 "Mask %8.8X%8.8X, DatumOffset %X, Width %X, Value %8.8X%8.8X, MergedValue %8.8X%8.8X\n",
642 ACPI_FORMAT_UINT64(mask),
643 field_datum_byte_offset,
644 obj_desc->common_field.access_byte_width,
645 ACPI_FORMAT_UINT64(field_value),
646 ACPI_FORMAT_UINT64(merged_value)));
647
648 /* Write the merged value */
649
650 status = acpi_ex_field_datum_io(obj_desc, field_datum_byte_offset,
651 &merged_value, ACPI_WRITE);
652
653 return_ACPI_STATUS(status);
654 }
655
656 /*******************************************************************************
657 *
658 * FUNCTION: acpi_ex_extract_from_field
659 *
660 * PARAMETERS: obj_desc - Field to be read
661 * Buffer - Where to store the field data
662 * buffer_length - Length of Buffer
663 *
664 * RETURN: Status
665 *
666 * DESCRIPTION: Retrieve the current value of the given field
667 *
668 ******************************************************************************/
669
670 acpi_status
671 acpi_ex_extract_from_field(union acpi_operand_object *obj_desc,
672 void *buffer, u32 buffer_length)
673 {
674 acpi_status status;
675 u64 raw_datum;
676 u64 merged_datum;
677 u32 field_offset = 0;
678 u32 buffer_offset = 0;
679 u32 buffer_tail_bits;
680 u32 datum_count;
681 u32 field_datum_count;
682 u32 access_bit_width;
683 u32 i;
684
685 ACPI_FUNCTION_TRACE(ex_extract_from_field);
686
687 /* Validate target buffer and clear it */
688
689 if (buffer_length <
690 ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length)) {
691 ACPI_ERROR((AE_INFO,
692 "Field size %u (bits) is too large for buffer (%u)",
693 obj_desc->common_field.bit_length, buffer_length));
694
695 return_ACPI_STATUS(AE_BUFFER_OVERFLOW);
696 }
697
698 ACPI_MEMSET(buffer, 0, buffer_length);
699 access_bit_width = ACPI_MUL_8(obj_desc->common_field.access_byte_width);
700
701 /* Handle the simple case here */
702
703 if ((obj_desc->common_field.start_field_bit_offset == 0) &&
704 (obj_desc->common_field.bit_length == access_bit_width)) {
705 status = acpi_ex_field_datum_io(obj_desc, 0, buffer, ACPI_READ);
706 return_ACPI_STATUS(status);
707 }
708
709 /* TBD: Move to common setup code */
710
711 /* Field algorithm is limited to sizeof(u64), truncate if needed */
712
713 if (obj_desc->common_field.access_byte_width > sizeof(u64)) {
714 obj_desc->common_field.access_byte_width = sizeof(u64);
715 access_bit_width = sizeof(u64) * 8;
716 }
717
718 /* Compute the number of datums (access width data items) */
719
720 datum_count =
721 ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
722 access_bit_width);
723
724 field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
725 obj_desc->common_field.
726 start_field_bit_offset,
727 access_bit_width);
728
729 /* Priming read from the field */
730
731 status =
732 acpi_ex_field_datum_io(obj_desc, field_offset, &raw_datum,
733 ACPI_READ);
734 if (ACPI_FAILURE(status)) {
735 return_ACPI_STATUS(status);
736 }
737 merged_datum =
738 raw_datum >> obj_desc->common_field.start_field_bit_offset;
739
740 /* Read the rest of the field */
741
742 for (i = 1; i < field_datum_count; i++) {
743
744 /* Get next input datum from the field */
745
746 field_offset += obj_desc->common_field.access_byte_width;
747 status = acpi_ex_field_datum_io(obj_desc, field_offset,
748 &raw_datum, ACPI_READ);
749 if (ACPI_FAILURE(status)) {
750 return_ACPI_STATUS(status);
751 }
752
753 /*
754 * Merge with previous datum if necessary.
755 *
756 * Note: Before the shift, check if the shift value will be larger than
757 * the integer size. If so, there is no need to perform the operation.
758 * This avoids the differences in behavior between different compilers
759 * concerning shift values larger than the target data width.
760 */
761 if (access_bit_width -
762 obj_desc->common_field.start_field_bit_offset <
763 ACPI_INTEGER_BIT_SIZE) {
764 merged_datum |=
765 raw_datum << (access_bit_width -
766 obj_desc->common_field.
767 start_field_bit_offset);
768 }
769
770 if (i == datum_count) {
771 break;
772 }
773
774 /* Write merged datum to target buffer */
775
776 ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
777 ACPI_MIN(obj_desc->common_field.access_byte_width,
778 buffer_length - buffer_offset));
779
780 buffer_offset += obj_desc->common_field.access_byte_width;
781 merged_datum =
782 raw_datum >> obj_desc->common_field.start_field_bit_offset;
783 }
784
785 /* Mask off any extra bits in the last datum */
786
787 buffer_tail_bits = obj_desc->common_field.bit_length % access_bit_width;
788 if (buffer_tail_bits) {
789 merged_datum &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
790 }
791
792 /* Write the last datum to the buffer */
793
794 ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum,
795 ACPI_MIN(obj_desc->common_field.access_byte_width,
796 buffer_length - buffer_offset));
797
798 return_ACPI_STATUS(AE_OK);
799 }
800
801 /*******************************************************************************
802 *
803 * FUNCTION: acpi_ex_insert_into_field
804 *
805 * PARAMETERS: obj_desc - Field to be written
806 * Buffer - Data to be written
807 * buffer_length - Length of Buffer
808 *
809 * RETURN: Status
810 *
811 * DESCRIPTION: Store the Buffer contents into the given field
812 *
813 ******************************************************************************/
814
815 acpi_status
816 acpi_ex_insert_into_field(union acpi_operand_object *obj_desc,
817 void *buffer, u32 buffer_length)
818 {
819 void *new_buffer;
820 acpi_status status;
821 u64 mask;
822 u64 width_mask;
823 u64 merged_datum;
824 u64 raw_datum = 0;
825 u32 field_offset = 0;
826 u32 buffer_offset = 0;
827 u32 buffer_tail_bits;
828 u32 datum_count;
829 u32 field_datum_count;
830 u32 access_bit_width;
831 u32 required_length;
832 u32 i;
833
834 ACPI_FUNCTION_TRACE(ex_insert_into_field);
835
836 /* Validate input buffer */
837
838 new_buffer = NULL;
839 required_length =
840 ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length);
841 /*
842 * We must have a buffer that is at least as long as the field
843 * we are writing to. This is because individual fields are
844 * indivisible and partial writes are not supported -- as per
845 * the ACPI specification.
846 */
847 if (buffer_length < required_length) {
848
849 /* We need to create a new buffer */
850
851 new_buffer = ACPI_ALLOCATE_ZEROED(required_length);
852 if (!new_buffer) {
853 return_ACPI_STATUS(AE_NO_MEMORY);
854 }
855
856 /*
857 * Copy the original data to the new buffer, starting
858 * at Byte zero. All unused (upper) bytes of the
859 * buffer will be 0.
860 */
861 ACPI_MEMCPY((char *)new_buffer, (char *)buffer, buffer_length);
862 buffer = new_buffer;
863 buffer_length = required_length;
864 }
865
866 /* TBD: Move to common setup code */
867
868 /* Algo is limited to sizeof(u64), so cut the access_byte_width */
869 if (obj_desc->common_field.access_byte_width > sizeof(u64)) {
870 obj_desc->common_field.access_byte_width = sizeof(u64);
871 }
872
873 access_bit_width = ACPI_MUL_8(obj_desc->common_field.access_byte_width);
874
875 /*
876 * Create the bitmasks used for bit insertion.
877 * Note: This if/else is used to bypass compiler differences with the
878 * shift operator
879 */
880 if (access_bit_width == ACPI_INTEGER_BIT_SIZE) {
881 width_mask = ACPI_UINT64_MAX;
882 } else {
883 width_mask = ACPI_MASK_BITS_ABOVE(access_bit_width);
884 }
885
886 mask = width_mask &
887 ACPI_MASK_BITS_BELOW(obj_desc->common_field.start_field_bit_offset);
888
889 /* Compute the number of datums (access width data items) */
890
891 datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
892 access_bit_width);
893
894 field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
895 obj_desc->common_field.
896 start_field_bit_offset,
897 access_bit_width);
898
899 /* Get initial Datum from the input buffer */
900
901 ACPI_MEMCPY(&raw_datum, buffer,
902 ACPI_MIN(obj_desc->common_field.access_byte_width,
903 buffer_length - buffer_offset));
904
905 merged_datum =
906 raw_datum << obj_desc->common_field.start_field_bit_offset;
907
908 /* Write the entire field */
909
910 for (i = 1; i < field_datum_count; i++) {
911
912 /* Write merged datum to the target field */
913
914 merged_datum &= mask;
915 status = acpi_ex_write_with_update_rule(obj_desc, mask,
916 merged_datum,
917 field_offset);
918 if (ACPI_FAILURE(status)) {
919 goto exit;
920 }
921
922 field_offset += obj_desc->common_field.access_byte_width;
923
924 /*
925 * Start new output datum by merging with previous input datum
926 * if necessary.
927 *
928 * Note: Before the shift, check if the shift value will be larger than
929 * the integer size. If so, there is no need to perform the operation.
930 * This avoids the differences in behavior between different compilers
931 * concerning shift values larger than the target data width.
932 */
933 if ((access_bit_width -
934 obj_desc->common_field.start_field_bit_offset) <
935 ACPI_INTEGER_BIT_SIZE) {
936 merged_datum =
937 raw_datum >> (access_bit_width -
938 obj_desc->common_field.
939 start_field_bit_offset);
940 } else {
941 merged_datum = 0;
942 }
943
944 mask = width_mask;
945
946 if (i == datum_count) {
947 break;
948 }
949
950 /* Get the next input datum from the buffer */
951
952 buffer_offset += obj_desc->common_field.access_byte_width;
953 ACPI_MEMCPY(&raw_datum, ((char *)buffer) + buffer_offset,
954 ACPI_MIN(obj_desc->common_field.access_byte_width,
955 buffer_length - buffer_offset));
956
957 merged_datum |=
958 raw_datum << obj_desc->common_field.start_field_bit_offset;
959 }
960
961 /* Mask off any extra bits in the last datum */
962
963 buffer_tail_bits = (obj_desc->common_field.bit_length +
964 obj_desc->common_field.start_field_bit_offset) %
965 access_bit_width;
966 if (buffer_tail_bits) {
967 mask &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
968 }
969
970 /* Write the last datum to the field */
971
972 merged_datum &= mask;
973 status = acpi_ex_write_with_update_rule(obj_desc,
974 mask, merged_datum,
975 field_offset);
976
977 exit:
978 /* Free temporary buffer if we used one */
979
980 if (new_buffer) {
981 ACPI_FREE(new_buffer);
982 }
983 return_ACPI_STATUS(status);
984 }
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