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Merge branches 'for-4.11/upstream-fixes', 'for-4.12/accutouch', 'for-4.12/cp2112...
[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 - 2017, 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, u64 *value, u32 read_write);
58
59 static u8
60 acpi_ex_register_overflow(union acpi_operand_object *obj_desc, u64 value);
61
62 static acpi_status
63 acpi_ex_setup_region(union acpi_operand_object *obj_desc,
64 u32 field_datum_byte_offset);
65
66 /*******************************************************************************
67 *
68 * FUNCTION: acpi_ex_setup_region
69 *
70 * PARAMETERS: obj_desc - Field to be read or written
71 * field_datum_byte_offset - Byte offset of this datum within the
72 * parent field
73 *
74 * RETURN: Status
75 *
76 * DESCRIPTION: Common processing for acpi_ex_extract_from_field and
77 * acpi_ex_insert_into_field. Initialize the Region if necessary and
78 * validate the request.
79 *
80 ******************************************************************************/
81
82 static acpi_status
83 acpi_ex_setup_region(union acpi_operand_object *obj_desc,
84 u32 field_datum_byte_offset)
85 {
86 acpi_status status = AE_OK;
87 union acpi_operand_object *rgn_desc;
88 u8 space_id;
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 space_id = rgn_desc->region.space_id;
105
106 /* Validate the Space ID */
107
108 if (!acpi_is_valid_space_id(space_id)) {
109 ACPI_ERROR((AE_INFO,
110 "Invalid/unknown Address Space ID: 0x%2.2X",
111 space_id));
112 return_ACPI_STATUS(AE_AML_INVALID_SPACE_ID);
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 /*
127 * Exit now for SMBus, GSBus or IPMI address space, it has a non-linear
128 * address space and the request cannot be directly validated
129 */
130 if (space_id == ACPI_ADR_SPACE_SMBUS ||
131 space_id == ACPI_ADR_SPACE_GSBUS ||
132 space_id == ACPI_ADR_SPACE_IPMI) {
133
134 /* SMBus or IPMI has a non-linear address space */
135
136 return_ACPI_STATUS(AE_OK);
137 }
138 #ifdef ACPI_UNDER_DEVELOPMENT
139 /*
140 * If the Field access is any_acc, we can now compute the optimal
141 * access (because we know know the length of the parent region)
142 */
143 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
144 if (ACPI_FAILURE(status)) {
145 return_ACPI_STATUS(status);
146 }
147 }
148 #endif
149
150 /*
151 * Validate the request. The entire request from the byte offset for a
152 * length of one field datum (access width) must fit within the region.
153 * (Region length is specified in bytes)
154 */
155 if (rgn_desc->region.length <
156 (obj_desc->common_field.base_byte_offset + field_datum_byte_offset +
157 obj_desc->common_field.access_byte_width)) {
158 if (acpi_gbl_enable_interpreter_slack) {
159 /*
160 * Slack mode only: We will go ahead and allow access to this
161 * field if it is within the region length rounded up to the next
162 * access width boundary. acpi_size cast for 64-bit compile.
163 */
164 if (ACPI_ROUND_UP(rgn_desc->region.length,
165 obj_desc->common_field.
166 access_byte_width) >=
167 ((acpi_size)obj_desc->common_field.
168 base_byte_offset +
169 obj_desc->common_field.access_byte_width +
170 field_datum_byte_offset)) {
171 return_ACPI_STATUS(AE_OK);
172 }
173 }
174
175 if (rgn_desc->region.length <
176 obj_desc->common_field.access_byte_width) {
177 /*
178 * This is the case where the access_type (acc_word, etc.) is wider
179 * than the region itself. For example, a region of length one
180 * byte, and a field with Dword access specified.
181 */
182 ACPI_ERROR((AE_INFO,
183 "Field [%4.4s] access width (%u bytes) "
184 "too large for region [%4.4s] (length %u)",
185 acpi_ut_get_node_name(obj_desc->
186 common_field.node),
187 obj_desc->common_field.access_byte_width,
188 acpi_ut_get_node_name(rgn_desc->region.
189 node),
190 rgn_desc->region.length));
191 }
192
193 /*
194 * Offset rounded up to next multiple of field width
195 * exceeds region length, indicate an error
196 */
197 ACPI_ERROR((AE_INFO,
198 "Field [%4.4s] Base+Offset+Width %u+%u+%u "
199 "is beyond end of region [%4.4s] (length %u)",
200 acpi_ut_get_node_name(obj_desc->common_field.node),
201 obj_desc->common_field.base_byte_offset,
202 field_datum_byte_offset,
203 obj_desc->common_field.access_byte_width,
204 acpi_ut_get_node_name(rgn_desc->region.node),
205 rgn_desc->region.length));
206
207 return_ACPI_STATUS(AE_AML_REGION_LIMIT);
208 }
209
210 return_ACPI_STATUS(AE_OK);
211 }
212
213 /*******************************************************************************
214 *
215 * FUNCTION: acpi_ex_access_region
216 *
217 * PARAMETERS: obj_desc - Field to be read
218 * field_datum_byte_offset - Byte offset of this datum within the
219 * parent field
220 * value - Where to store value (must at least
221 * 64 bits)
222 * function - Read or Write flag plus other region-
223 * dependent flags
224 *
225 * RETURN: Status
226 *
227 * DESCRIPTION: Read or Write a single field datum to an Operation Region.
228 *
229 ******************************************************************************/
230
231 acpi_status
232 acpi_ex_access_region(union acpi_operand_object *obj_desc,
233 u32 field_datum_byte_offset, u64 *value, u32 function)
234 {
235 acpi_status status;
236 union acpi_operand_object *rgn_desc;
237 u32 region_offset;
238
239 ACPI_FUNCTION_TRACE(ex_access_region);
240
241 /*
242 * Ensure that the region operands are fully evaluated and verify
243 * the validity of the request
244 */
245 status = acpi_ex_setup_region(obj_desc, field_datum_byte_offset);
246 if (ACPI_FAILURE(status)) {
247 return_ACPI_STATUS(status);
248 }
249
250 /*
251 * The physical address of this field datum is:
252 *
253 * 1) The base of the region, plus
254 * 2) The base offset of the field, plus
255 * 3) The current offset into the field
256 */
257 rgn_desc = obj_desc->common_field.region_obj;
258 region_offset =
259 obj_desc->common_field.base_byte_offset + field_datum_byte_offset;
260
261 if ((function & ACPI_IO_MASK) == ACPI_READ) {
262 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[READ]"));
263 } else {
264 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[WRITE]"));
265 }
266
267 ACPI_DEBUG_PRINT_RAW((ACPI_DB_BFIELD,
268 " Region [%s:%X], Width %X, ByteBase %X, Offset %X at %8.8X%8.8X\n",
269 acpi_ut_get_region_name(rgn_desc->region.
270 space_id),
271 rgn_desc->region.space_id,
272 obj_desc->common_field.access_byte_width,
273 obj_desc->common_field.base_byte_offset,
274 field_datum_byte_offset,
275 ACPI_FORMAT_UINT64(rgn_desc->region.address +
276 region_offset)));
277
278 /* Invoke the appropriate address_space/op_region handler */
279
280 status = acpi_ev_address_space_dispatch(rgn_desc, obj_desc,
281 function, region_offset,
282 ACPI_MUL_8(obj_desc->
283 common_field.
284 access_byte_width),
285 value);
286
287 if (ACPI_FAILURE(status)) {
288 if (status == AE_NOT_IMPLEMENTED) {
289 ACPI_ERROR((AE_INFO,
290 "Region %s (ID=%u) not implemented",
291 acpi_ut_get_region_name(rgn_desc->region.
292 space_id),
293 rgn_desc->region.space_id));
294 } else if (status == AE_NOT_EXIST) {
295 ACPI_ERROR((AE_INFO,
296 "Region %s (ID=%u) has no handler",
297 acpi_ut_get_region_name(rgn_desc->region.
298 space_id),
299 rgn_desc->region.space_id));
300 }
301 }
302
303 return_ACPI_STATUS(status);
304 }
305
306 /*******************************************************************************
307 *
308 * FUNCTION: acpi_ex_register_overflow
309 *
310 * PARAMETERS: obj_desc - Register(Field) to be written
311 * value - Value to be stored
312 *
313 * RETURN: TRUE if value overflows the field, FALSE otherwise
314 *
315 * DESCRIPTION: Check if a value is out of range of the field being written.
316 * Used to check if the values written to Index and Bank registers
317 * are out of range. Normally, the value is simply truncated
318 * to fit the field, but this case is most likely a serious
319 * coding error in the ASL.
320 *
321 ******************************************************************************/
322
323 static u8
324 acpi_ex_register_overflow(union acpi_operand_object *obj_desc, u64 value)
325 {
326
327 if (obj_desc->common_field.bit_length >= ACPI_INTEGER_BIT_SIZE) {
328 /*
329 * The field is large enough to hold the maximum integer, so we can
330 * never overflow it.
331 */
332 return (FALSE);
333 }
334
335 if (value >= ((u64) 1 << obj_desc->common_field.bit_length)) {
336 /*
337 * The Value is larger than the maximum value that can fit into
338 * the register.
339 */
340 ACPI_ERROR((AE_INFO,
341 "Index value 0x%8.8X%8.8X overflows field width 0x%X",
342 ACPI_FORMAT_UINT64(value),
343 obj_desc->common_field.bit_length));
344
345 return (TRUE);
346 }
347
348 /* The Value will fit into the field with no truncation */
349
350 return (FALSE);
351 }
352
353 /*******************************************************************************
354 *
355 * FUNCTION: acpi_ex_field_datum_io
356 *
357 * PARAMETERS: obj_desc - Field to be read
358 * field_datum_byte_offset - Byte offset of this datum within the
359 * parent field
360 * value - Where to store value (must be 64 bits)
361 * read_write - Read or Write flag
362 *
363 * RETURN: Status
364 *
365 * DESCRIPTION: Read or Write a single datum of a field. The field_type is
366 * demultiplexed here to handle the different types of fields
367 * (buffer_field, region_field, index_field, bank_field)
368 *
369 ******************************************************************************/
370
371 static acpi_status
372 acpi_ex_field_datum_io(union acpi_operand_object *obj_desc,
373 u32 field_datum_byte_offset, u64 *value, u32 read_write)
374 {
375 acpi_status status;
376 u64 local_value;
377
378 ACPI_FUNCTION_TRACE_U32(ex_field_datum_io, field_datum_byte_offset);
379
380 if (read_write == ACPI_READ) {
381 if (!value) {
382 local_value = 0;
383
384 /* To support reads without saving return value */
385 value = &local_value;
386 }
387
388 /* Clear the entire return buffer first, [Very Important!] */
389
390 *value = 0;
391 }
392
393 /*
394 * The four types of fields are:
395 *
396 * buffer_field - Read/write from/to a Buffer
397 * region_field - Read/write from/to a Operation Region.
398 * bank_field - Write to a Bank Register, then read/write from/to an
399 * operation_region
400 * index_field - Write to an Index Register, then read/write from/to a
401 * Data Register
402 */
403 switch (obj_desc->common.type) {
404 case ACPI_TYPE_BUFFER_FIELD:
405 /*
406 * If the buffer_field arguments have not been previously evaluated,
407 * evaluate them now and save the results.
408 */
409 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
410 status = acpi_ds_get_buffer_field_arguments(obj_desc);
411 if (ACPI_FAILURE(status)) {
412 return_ACPI_STATUS(status);
413 }
414 }
415
416 if (read_write == ACPI_READ) {
417 /*
418 * Copy the data from the source buffer.
419 * Length is the field width in bytes.
420 */
421 memcpy(value,
422 (obj_desc->buffer_field.buffer_obj)->buffer.
423 pointer +
424 obj_desc->buffer_field.base_byte_offset +
425 field_datum_byte_offset,
426 obj_desc->common_field.access_byte_width);
427 } else {
428 /*
429 * Copy the data to the target buffer.
430 * Length is the field width in bytes.
431 */
432 memcpy((obj_desc->buffer_field.buffer_obj)->buffer.
433 pointer +
434 obj_desc->buffer_field.base_byte_offset +
435 field_datum_byte_offset, value,
436 obj_desc->common_field.access_byte_width);
437 }
438
439 status = AE_OK;
440 break;
441
442 case ACPI_TYPE_LOCAL_BANK_FIELD:
443 /*
444 * Ensure that the bank_value is not beyond the capacity of
445 * the register
446 */
447 if (acpi_ex_register_overflow(obj_desc->bank_field.bank_obj,
448 (u64) obj_desc->bank_field.
449 value)) {
450 return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
451 }
452
453 /*
454 * For bank_fields, we must write the bank_value to the bank_register
455 * (itself a region_field) before we can access the data.
456 */
457 status =
458 acpi_ex_insert_into_field(obj_desc->bank_field.bank_obj,
459 &obj_desc->bank_field.value,
460 sizeof(obj_desc->bank_field.
461 value));
462 if (ACPI_FAILURE(status)) {
463 return_ACPI_STATUS(status);
464 }
465
466 /*
467 * Now that the Bank has been selected, fall through to the
468 * region_field case and write the datum to the Operation Region
469 */
470
471 /*lint -fallthrough */
472
473 case ACPI_TYPE_LOCAL_REGION_FIELD:
474 /*
475 * For simple region_fields, we just directly access the owning
476 * Operation Region.
477 */
478 status =
479 acpi_ex_access_region(obj_desc, field_datum_byte_offset,
480 value, read_write);
481 break;
482
483 case ACPI_TYPE_LOCAL_INDEX_FIELD:
484 /*
485 * Ensure that the index_value is not beyond the capacity of
486 * the register
487 */
488 if (acpi_ex_register_overflow(obj_desc->index_field.index_obj,
489 (u64) obj_desc->index_field.
490 value)) {
491 return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
492 }
493
494 /* Write the index value to the index_register (itself a region_field) */
495
496 field_datum_byte_offset += obj_desc->index_field.value;
497
498 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
499 "Write to Index Register: Value %8.8X\n",
500 field_datum_byte_offset));
501
502 status =
503 acpi_ex_insert_into_field(obj_desc->index_field.index_obj,
504 &field_datum_byte_offset,
505 sizeof(field_datum_byte_offset));
506 if (ACPI_FAILURE(status)) {
507 return_ACPI_STATUS(status);
508 }
509
510 if (read_write == ACPI_READ) {
511
512 /* Read the datum from the data_register */
513
514 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
515 "Read from Data Register\n"));
516
517 status =
518 acpi_ex_extract_from_field(obj_desc->index_field.
519 data_obj, value,
520 sizeof(u64));
521 } else {
522 /* Write the datum to the data_register */
523
524 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
525 "Write to Data Register: Value %8.8X%8.8X\n",
526 ACPI_FORMAT_UINT64(*value)));
527
528 status =
529 acpi_ex_insert_into_field(obj_desc->index_field.
530 data_obj, value,
531 sizeof(u64));
532 }
533 break;
534
535 default:
536
537 ACPI_ERROR((AE_INFO, "Wrong object type in field I/O %u",
538 obj_desc->common.type));
539 status = AE_AML_INTERNAL;
540 break;
541 }
542
543 if (ACPI_SUCCESS(status)) {
544 if (read_write == ACPI_READ) {
545 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
546 "Value Read %8.8X%8.8X, Width %u\n",
547 ACPI_FORMAT_UINT64(*value),
548 obj_desc->common_field.
549 access_byte_width));
550 } else {
551 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
552 "Value Written %8.8X%8.8X, Width %u\n",
553 ACPI_FORMAT_UINT64(*value),
554 obj_desc->common_field.
555 access_byte_width));
556 }
557 }
558
559 return_ACPI_STATUS(status);
560 }
561
562 /*******************************************************************************
563 *
564 * FUNCTION: acpi_ex_write_with_update_rule
565 *
566 * PARAMETERS: obj_desc - Field to be written
567 * mask - bitmask within field datum
568 * field_value - Value to write
569 * field_datum_byte_offset - Offset of datum within field
570 *
571 * RETURN: Status
572 *
573 * DESCRIPTION: Apply the field update rule to a field write
574 *
575 ******************************************************************************/
576
577 acpi_status
578 acpi_ex_write_with_update_rule(union acpi_operand_object *obj_desc,
579 u64 mask,
580 u64 field_value, u32 field_datum_byte_offset)
581 {
582 acpi_status status = AE_OK;
583 u64 merged_value;
584 u64 current_value;
585
586 ACPI_FUNCTION_TRACE_U32(ex_write_with_update_rule, mask);
587
588 /* Start with the new bits */
589
590 merged_value = field_value;
591
592 /* If the mask is all ones, we don't need to worry about the update rule */
593
594 if (mask != ACPI_UINT64_MAX) {
595
596 /* Decode the update rule */
597
598 switch (obj_desc->common_field.
599 field_flags & AML_FIELD_UPDATE_RULE_MASK) {
600 case AML_FIELD_UPDATE_PRESERVE:
601 /*
602 * Check if update rule needs to be applied (not if mask is all
603 * ones) The left shift drops the bits we want to ignore.
604 */
605 if ((~mask << (ACPI_MUL_8(sizeof(mask)) -
606 ACPI_MUL_8(obj_desc->common_field.
607 access_byte_width))) != 0) {
608 /*
609 * Read the current contents of the byte/word/dword containing
610 * the field, and merge with the new field value.
611 */
612 status =
613 acpi_ex_field_datum_io(obj_desc,
614 field_datum_byte_offset,
615 &current_value,
616 ACPI_READ);
617 if (ACPI_FAILURE(status)) {
618 return_ACPI_STATUS(status);
619 }
620
621 merged_value |= (current_value & ~mask);
622 }
623 break;
624
625 case AML_FIELD_UPDATE_WRITE_AS_ONES:
626
627 /* Set positions outside the field to all ones */
628
629 merged_value |= ~mask;
630 break;
631
632 case AML_FIELD_UPDATE_WRITE_AS_ZEROS:
633
634 /* Set positions outside the field to all zeros */
635
636 merged_value &= mask;
637 break;
638
639 default:
640
641 ACPI_ERROR((AE_INFO,
642 "Unknown UpdateRule value: 0x%X",
643 (obj_desc->common_field.field_flags &
644 AML_FIELD_UPDATE_RULE_MASK)));
645 return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
646 }
647 }
648
649 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
650 "Mask %8.8X%8.8X, DatumOffset %X, Width %X, "
651 "Value %8.8X%8.8X, MergedValue %8.8X%8.8X\n",
652 ACPI_FORMAT_UINT64(mask),
653 field_datum_byte_offset,
654 obj_desc->common_field.access_byte_width,
655 ACPI_FORMAT_UINT64(field_value),
656 ACPI_FORMAT_UINT64(merged_value)));
657
658 /* Write the merged value */
659
660 status =
661 acpi_ex_field_datum_io(obj_desc, field_datum_byte_offset,
662 &merged_value, ACPI_WRITE);
663
664 return_ACPI_STATUS(status);
665 }
666
667 /*******************************************************************************
668 *
669 * FUNCTION: acpi_ex_extract_from_field
670 *
671 * PARAMETERS: obj_desc - Field to be read
672 * buffer - Where to store the field data
673 * buffer_length - Length of Buffer
674 *
675 * RETURN: Status
676 *
677 * DESCRIPTION: Retrieve the current value of the given field
678 *
679 ******************************************************************************/
680
681 acpi_status
682 acpi_ex_extract_from_field(union acpi_operand_object *obj_desc,
683 void *buffer, u32 buffer_length)
684 {
685 acpi_status status;
686 u64 raw_datum;
687 u64 merged_datum;
688 u32 field_offset = 0;
689 u32 buffer_offset = 0;
690 u32 buffer_tail_bits;
691 u32 datum_count;
692 u32 field_datum_count;
693 u32 access_bit_width;
694 u32 i;
695
696 ACPI_FUNCTION_TRACE(ex_extract_from_field);
697
698 /* Validate target buffer and clear it */
699
700 if (buffer_length <
701 ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length)) {
702 ACPI_ERROR((AE_INFO,
703 "Field size %u (bits) is too large for buffer (%u)",
704 obj_desc->common_field.bit_length, buffer_length));
705
706 return_ACPI_STATUS(AE_BUFFER_OVERFLOW);
707 }
708
709 memset(buffer, 0, buffer_length);
710 access_bit_width = ACPI_MUL_8(obj_desc->common_field.access_byte_width);
711
712 /* Handle the simple case here */
713
714 if ((obj_desc->common_field.start_field_bit_offset == 0) &&
715 (obj_desc->common_field.bit_length == access_bit_width)) {
716 if (buffer_length >= sizeof(u64)) {
717 status =
718 acpi_ex_field_datum_io(obj_desc, 0, buffer,
719 ACPI_READ);
720 } else {
721 /* Use raw_datum (u64) to handle buffers < 64 bits */
722
723 status =
724 acpi_ex_field_datum_io(obj_desc, 0, &raw_datum,
725 ACPI_READ);
726 memcpy(buffer, &raw_datum, buffer_length);
727 }
728
729 return_ACPI_STATUS(status);
730 }
731
732 /* TBD: Move to common setup code */
733
734 /* Field algorithm is limited to sizeof(u64), truncate if needed */
735
736 if (obj_desc->common_field.access_byte_width > sizeof(u64)) {
737 obj_desc->common_field.access_byte_width = sizeof(u64);
738 access_bit_width = sizeof(u64) * 8;
739 }
740
741 /* Compute the number of datums (access width data items) */
742
743 datum_count =
744 ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
745 access_bit_width);
746
747 field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
748 obj_desc->common_field.
749 start_field_bit_offset,
750 access_bit_width);
751
752 /* Priming read from the field */
753
754 status =
755 acpi_ex_field_datum_io(obj_desc, field_offset, &raw_datum,
756 ACPI_READ);
757 if (ACPI_FAILURE(status)) {
758 return_ACPI_STATUS(status);
759 }
760 merged_datum =
761 raw_datum >> obj_desc->common_field.start_field_bit_offset;
762
763 /* Read the rest of the field */
764
765 for (i = 1; i < field_datum_count; i++) {
766
767 /* Get next input datum from the field */
768
769 field_offset += obj_desc->common_field.access_byte_width;
770 status =
771 acpi_ex_field_datum_io(obj_desc, field_offset, &raw_datum,
772 ACPI_READ);
773 if (ACPI_FAILURE(status)) {
774 return_ACPI_STATUS(status);
775 }
776
777 /*
778 * Merge with previous datum if necessary.
779 *
780 * Note: Before the shift, check if the shift value will be larger than
781 * the integer size. If so, there is no need to perform the operation.
782 * This avoids the differences in behavior between different compilers
783 * concerning shift values larger than the target data width.
784 */
785 if (access_bit_width -
786 obj_desc->common_field.start_field_bit_offset <
787 ACPI_INTEGER_BIT_SIZE) {
788 merged_datum |=
789 raw_datum << (access_bit_width -
790 obj_desc->common_field.
791 start_field_bit_offset);
792 }
793
794 if (i == datum_count) {
795 break;
796 }
797
798 /* Write merged datum to target buffer */
799
800 memcpy(((char *)buffer) + buffer_offset, &merged_datum,
801 ACPI_MIN(obj_desc->common_field.access_byte_width,
802 buffer_length - buffer_offset));
803
804 buffer_offset += obj_desc->common_field.access_byte_width;
805 merged_datum =
806 raw_datum >> obj_desc->common_field.start_field_bit_offset;
807 }
808
809 /* Mask off any extra bits in the last datum */
810
811 buffer_tail_bits = obj_desc->common_field.bit_length % access_bit_width;
812 if (buffer_tail_bits) {
813 merged_datum &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
814 }
815
816 /* Write the last datum to the buffer */
817
818 memcpy(((char *)buffer) + buffer_offset, &merged_datum,
819 ACPI_MIN(obj_desc->common_field.access_byte_width,
820 buffer_length - buffer_offset));
821
822 return_ACPI_STATUS(AE_OK);
823 }
824
825 /*******************************************************************************
826 *
827 * FUNCTION: acpi_ex_insert_into_field
828 *
829 * PARAMETERS: obj_desc - Field to be written
830 * buffer - Data to be written
831 * buffer_length - Length of Buffer
832 *
833 * RETURN: Status
834 *
835 * DESCRIPTION: Store the Buffer contents into the given field
836 *
837 ******************************************************************************/
838
839 acpi_status
840 acpi_ex_insert_into_field(union acpi_operand_object *obj_desc,
841 void *buffer, u32 buffer_length)
842 {
843 void *new_buffer;
844 acpi_status status;
845 u64 mask;
846 u64 width_mask;
847 u64 merged_datum;
848 u64 raw_datum = 0;
849 u32 field_offset = 0;
850 u32 buffer_offset = 0;
851 u32 buffer_tail_bits;
852 u32 datum_count;
853 u32 field_datum_count;
854 u32 access_bit_width;
855 u32 required_length;
856 u32 i;
857
858 ACPI_FUNCTION_TRACE(ex_insert_into_field);
859
860 /* Validate input buffer */
861
862 new_buffer = NULL;
863 required_length =
864 ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length);
865
866 /*
867 * We must have a buffer that is at least as long as the field
868 * we are writing to. This is because individual fields are
869 * indivisible and partial writes are not supported -- as per
870 * the ACPI specification.
871 */
872 if (buffer_length < required_length) {
873
874 /* We need to create a new buffer */
875
876 new_buffer = ACPI_ALLOCATE_ZEROED(required_length);
877 if (!new_buffer) {
878 return_ACPI_STATUS(AE_NO_MEMORY);
879 }
880
881 /*
882 * Copy the original data to the new buffer, starting
883 * at Byte zero. All unused (upper) bytes of the
884 * buffer will be 0.
885 */
886 memcpy((char *)new_buffer, (char *)buffer, buffer_length);
887 buffer = new_buffer;
888 buffer_length = required_length;
889 }
890
891 /* TBD: Move to common setup code */
892
893 /* Algo is limited to sizeof(u64), so cut the access_byte_width */
894 if (obj_desc->common_field.access_byte_width > sizeof(u64)) {
895 obj_desc->common_field.access_byte_width = sizeof(u64);
896 }
897
898 access_bit_width = ACPI_MUL_8(obj_desc->common_field.access_byte_width);
899
900 /* Create the bitmasks used for bit insertion */
901
902 width_mask = ACPI_MASK_BITS_ABOVE_64(access_bit_width);
903 mask = width_mask &
904 ACPI_MASK_BITS_BELOW(obj_desc->common_field.start_field_bit_offset);
905
906 /* Compute the number of datums (access width data items) */
907
908 datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
909 access_bit_width);
910
911 field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
912 obj_desc->common_field.
913 start_field_bit_offset,
914 access_bit_width);
915
916 /* Get initial Datum from the input buffer */
917
918 memcpy(&raw_datum, buffer,
919 ACPI_MIN(obj_desc->common_field.access_byte_width,
920 buffer_length - buffer_offset));
921
922 merged_datum =
923 raw_datum << obj_desc->common_field.start_field_bit_offset;
924
925 /* Write the entire field */
926
927 for (i = 1; i < field_datum_count; i++) {
928
929 /* Write merged datum to the target field */
930
931 merged_datum &= mask;
932 status =
933 acpi_ex_write_with_update_rule(obj_desc, mask, merged_datum,
934 field_offset);
935 if (ACPI_FAILURE(status)) {
936 goto exit;
937 }
938
939 field_offset += obj_desc->common_field.access_byte_width;
940
941 /*
942 * Start new output datum by merging with previous input datum
943 * if necessary.
944 *
945 * Note: Before the shift, check if the shift value will be larger than
946 * the integer size. If so, there is no need to perform the operation.
947 * This avoids the differences in behavior between different compilers
948 * concerning shift values larger than the target data width.
949 */
950 if ((access_bit_width -
951 obj_desc->common_field.start_field_bit_offset) <
952 ACPI_INTEGER_BIT_SIZE) {
953 merged_datum =
954 raw_datum >> (access_bit_width -
955 obj_desc->common_field.
956 start_field_bit_offset);
957 } else {
958 merged_datum = 0;
959 }
960
961 mask = width_mask;
962
963 if (i == datum_count) {
964 break;
965 }
966
967 /* Get the next input datum from the buffer */
968
969 buffer_offset += obj_desc->common_field.access_byte_width;
970 memcpy(&raw_datum, ((char *)buffer) + buffer_offset,
971 ACPI_MIN(obj_desc->common_field.access_byte_width,
972 buffer_length - buffer_offset));
973
974 merged_datum |=
975 raw_datum << obj_desc->common_field.start_field_bit_offset;
976 }
977
978 /* Mask off any extra bits in the last datum */
979
980 buffer_tail_bits = (obj_desc->common_field.bit_length +
981 obj_desc->common_field.start_field_bit_offset) %
982 access_bit_width;
983 if (buffer_tail_bits) {
984 mask &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
985 }
986
987 /* Write the last datum to the field */
988
989 merged_datum &= mask;
990 status =
991 acpi_ex_write_with_update_rule(obj_desc, mask, merged_datum,
992 field_offset);
993
994 exit:
995 /* Free temporary buffer if we used one */
996
997 if (new_buffer) {
998 ACPI_FREE(new_buffer);
999 }
1000 return_ACPI_STATUS(status);
1001 }
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