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Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[deliverable/linux.git] / drivers / acpi / acpica / exfldio.c
1 /******************************************************************************
2 *
3 * Module Name: exfldio - Aml Field I/O
4 *
5 *****************************************************************************/
6
7 /*
8 * Copyright (C) 2000 - 2015, 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) too large for region [%4.4s] (length %u)",
184 acpi_ut_get_node_name(obj_desc->
185 common_field.node),
186 obj_desc->common_field.access_byte_width,
187 acpi_ut_get_node_name(rgn_desc->region.
188 node),
189 rgn_desc->region.length));
190 }
191
192 /*
193 * Offset rounded up to next multiple of field width
194 * exceeds region length, indicate an error
195 */
196 ACPI_ERROR((AE_INFO,
197 "Field [%4.4s] Base+Offset+Width %u+%u+%u is beyond end of region [%4.4s] (length %u)",
198 acpi_ut_get_node_name(obj_desc->common_field.node),
199 obj_desc->common_field.base_byte_offset,
200 field_datum_byte_offset,
201 obj_desc->common_field.access_byte_width,
202 acpi_ut_get_node_name(rgn_desc->region.node),
203 rgn_desc->region.length));
204
205 return_ACPI_STATUS(AE_AML_REGION_LIMIT);
206 }
207
208 return_ACPI_STATUS(AE_OK);
209 }
210
211 /*******************************************************************************
212 *
213 * FUNCTION: acpi_ex_access_region
214 *
215 * PARAMETERS: obj_desc - Field to be read
216 * field_datum_byte_offset - Byte offset of this datum within the
217 * parent field
218 * value - Where to store value (must at least
219 * 64 bits)
220 * function - Read or Write flag plus other region-
221 * dependent flags
222 *
223 * RETURN: Status
224 *
225 * DESCRIPTION: Read or Write a single field datum to an Operation Region.
226 *
227 ******************************************************************************/
228
229 acpi_status
230 acpi_ex_access_region(union acpi_operand_object *obj_desc,
231 u32 field_datum_byte_offset, u64 *value, u32 function)
232 {
233 acpi_status status;
234 union acpi_operand_object *rgn_desc;
235 u32 region_offset;
236
237 ACPI_FUNCTION_TRACE(ex_access_region);
238
239 /*
240 * Ensure that the region operands are fully evaluated and verify
241 * the validity of the request
242 */
243 status = acpi_ex_setup_region(obj_desc, field_datum_byte_offset);
244 if (ACPI_FAILURE(status)) {
245 return_ACPI_STATUS(status);
246 }
247
248 /*
249 * The physical address of this field datum is:
250 *
251 * 1) The base of the region, plus
252 * 2) The base offset of the field, plus
253 * 3) The current offset into the field
254 */
255 rgn_desc = obj_desc->common_field.region_obj;
256 region_offset =
257 obj_desc->common_field.base_byte_offset + field_datum_byte_offset;
258
259 if ((function & ACPI_IO_MASK) == ACPI_READ) {
260 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[READ]"));
261 } else {
262 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[WRITE]"));
263 }
264
265 ACPI_DEBUG_PRINT_RAW((ACPI_DB_BFIELD,
266 " Region [%s:%X], Width %X, ByteBase %X, Offset %X at %8.8X%8.8X\n",
267 acpi_ut_get_region_name(rgn_desc->region.
268 space_id),
269 rgn_desc->region.space_id,
270 obj_desc->common_field.access_byte_width,
271 obj_desc->common_field.base_byte_offset,
272 field_datum_byte_offset,
273 ACPI_FORMAT_UINT64(rgn_desc->region.address +
274 region_offset)));
275
276 /* Invoke the appropriate address_space/op_region handler */
277
278 status = acpi_ev_address_space_dispatch(rgn_desc, obj_desc,
279 function, region_offset,
280 ACPI_MUL_8(obj_desc->
281 common_field.
282 access_byte_width),
283 value);
284
285 if (ACPI_FAILURE(status)) {
286 if (status == AE_NOT_IMPLEMENTED) {
287 ACPI_ERROR((AE_INFO,
288 "Region %s (ID=%u) not implemented",
289 acpi_ut_get_region_name(rgn_desc->region.
290 space_id),
291 rgn_desc->region.space_id));
292 } else if (status == AE_NOT_EXIST) {
293 ACPI_ERROR((AE_INFO,
294 "Region %s (ID=%u) has no handler",
295 acpi_ut_get_region_name(rgn_desc->region.
296 space_id),
297 rgn_desc->region.space_id));
298 }
299 }
300
301 return_ACPI_STATUS(status);
302 }
303
304 /*******************************************************************************
305 *
306 * FUNCTION: acpi_ex_register_overflow
307 *
308 * PARAMETERS: obj_desc - Register(Field) to be written
309 * value - Value to be stored
310 *
311 * RETURN: TRUE if value overflows the field, FALSE otherwise
312 *
313 * DESCRIPTION: Check if a value is out of range of the field being written.
314 * Used to check if the values written to Index and Bank registers
315 * are out of range. Normally, the value is simply truncated
316 * to fit the field, but this case is most likely a serious
317 * coding error in the ASL.
318 *
319 ******************************************************************************/
320
321 static u8
322 acpi_ex_register_overflow(union acpi_operand_object *obj_desc, u64 value)
323 {
324
325 if (obj_desc->common_field.bit_length >= ACPI_INTEGER_BIT_SIZE) {
326 /*
327 * The field is large enough to hold the maximum integer, so we can
328 * never overflow it.
329 */
330 return (FALSE);
331 }
332
333 if (value >= ((u64) 1 << obj_desc->common_field.bit_length)) {
334 /*
335 * The Value is larger than the maximum value that can fit into
336 * the register.
337 */
338 ACPI_ERROR((AE_INFO,
339 "Index value 0x%8.8X%8.8X overflows field width 0x%X",
340 ACPI_FORMAT_UINT64(value),
341 obj_desc->common_field.bit_length));
342
343 return (TRUE);
344 }
345
346 /* The Value will fit into the field with no truncation */
347
348 return (FALSE);
349 }
350
351 /*******************************************************************************
352 *
353 * FUNCTION: acpi_ex_field_datum_io
354 *
355 * PARAMETERS: obj_desc - Field to be read
356 * field_datum_byte_offset - Byte offset of this datum within the
357 * parent field
358 * value - Where to store value (must be 64 bits)
359 * read_write - Read or Write flag
360 *
361 * RETURN: Status
362 *
363 * DESCRIPTION: Read or Write a single datum of a field. The field_type is
364 * demultiplexed here to handle the different types of fields
365 * (buffer_field, region_field, index_field, bank_field)
366 *
367 ******************************************************************************/
368
369 static acpi_status
370 acpi_ex_field_datum_io(union acpi_operand_object *obj_desc,
371 u32 field_datum_byte_offset, u64 *value, u32 read_write)
372 {
373 acpi_status status;
374 u64 local_value;
375
376 ACPI_FUNCTION_TRACE_U32(ex_field_datum_io, field_datum_byte_offset);
377
378 if (read_write == ACPI_READ) {
379 if (!value) {
380 local_value = 0;
381
382 /* To support reads without saving return value */
383 value = &local_value;
384 }
385
386 /* Clear the entire return buffer first, [Very Important!] */
387
388 *value = 0;
389 }
390
391 /*
392 * The four types of fields are:
393 *
394 * buffer_field - Read/write from/to a Buffer
395 * region_field - Read/write from/to a Operation Region.
396 * bank_field - Write to a Bank Register, then read/write from/to an
397 * operation_region
398 * index_field - Write to an Index Register, then read/write from/to a
399 * Data Register
400 */
401 switch (obj_desc->common.type) {
402 case ACPI_TYPE_BUFFER_FIELD:
403 /*
404 * If the buffer_field arguments have not been previously evaluated,
405 * evaluate them now and save the results.
406 */
407 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
408 status = acpi_ds_get_buffer_field_arguments(obj_desc);
409 if (ACPI_FAILURE(status)) {
410 return_ACPI_STATUS(status);
411 }
412 }
413
414 if (read_write == ACPI_READ) {
415 /*
416 * Copy the data from the source buffer.
417 * Length is the field width in bytes.
418 */
419 memcpy(value,
420 (obj_desc->buffer_field.buffer_obj)->buffer.
421 pointer +
422 obj_desc->buffer_field.base_byte_offset +
423 field_datum_byte_offset,
424 obj_desc->common_field.access_byte_width);
425 } else {
426 /*
427 * Copy the data to the target buffer.
428 * Length is the field width in bytes.
429 */
430 memcpy((obj_desc->buffer_field.buffer_obj)->buffer.
431 pointer +
432 obj_desc->buffer_field.base_byte_offset +
433 field_datum_byte_offset, value,
434 obj_desc->common_field.access_byte_width);
435 }
436
437 status = AE_OK;
438 break;
439
440 case ACPI_TYPE_LOCAL_BANK_FIELD:
441 /*
442 * Ensure that the bank_value is not beyond the capacity of
443 * the register
444 */
445 if (acpi_ex_register_overflow(obj_desc->bank_field.bank_obj,
446 (u64) obj_desc->bank_field.
447 value)) {
448 return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
449 }
450
451 /*
452 * For bank_fields, we must write the bank_value to the bank_register
453 * (itself a region_field) before we can access the data.
454 */
455 status =
456 acpi_ex_insert_into_field(obj_desc->bank_field.bank_obj,
457 &obj_desc->bank_field.value,
458 sizeof(obj_desc->bank_field.
459 value));
460 if (ACPI_FAILURE(status)) {
461 return_ACPI_STATUS(status);
462 }
463
464 /*
465 * Now that the Bank has been selected, fall through to the
466 * region_field case and write the datum to the Operation Region
467 */
468
469 /*lint -fallthrough */
470
471 case ACPI_TYPE_LOCAL_REGION_FIELD:
472 /*
473 * For simple region_fields, we just directly access the owning
474 * Operation Region.
475 */
476 status =
477 acpi_ex_access_region(obj_desc, field_datum_byte_offset,
478 value, read_write);
479 break;
480
481 case ACPI_TYPE_LOCAL_INDEX_FIELD:
482 /*
483 * Ensure that the index_value is not beyond the capacity of
484 * the register
485 */
486 if (acpi_ex_register_overflow(obj_desc->index_field.index_obj,
487 (u64) obj_desc->index_field.
488 value)) {
489 return_ACPI_STATUS(AE_AML_REGISTER_LIMIT);
490 }
491
492 /* Write the index value to the index_register (itself a region_field) */
493
494 field_datum_byte_offset += obj_desc->index_field.value;
495
496 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
497 "Write to Index Register: Value %8.8X\n",
498 field_datum_byte_offset));
499
500 status =
501 acpi_ex_insert_into_field(obj_desc->index_field.index_obj,
502 &field_datum_byte_offset,
503 sizeof(field_datum_byte_offset));
504 if (ACPI_FAILURE(status)) {
505 return_ACPI_STATUS(status);
506 }
507
508 if (read_write == ACPI_READ) {
509
510 /* Read the datum from the data_register */
511
512 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
513 "Read from Data Register\n"));
514
515 status =
516 acpi_ex_extract_from_field(obj_desc->index_field.
517 data_obj, value,
518 sizeof(u64));
519 } else {
520 /* Write the datum to the data_register */
521
522 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
523 "Write to Data Register: Value %8.8X%8.8X\n",
524 ACPI_FORMAT_UINT64(*value)));
525
526 status =
527 acpi_ex_insert_into_field(obj_desc->index_field.
528 data_obj, value,
529 sizeof(u64));
530 }
531 break;
532
533 default:
534
535 ACPI_ERROR((AE_INFO, "Wrong object type in field I/O %u",
536 obj_desc->common.type));
537 status = AE_AML_INTERNAL;
538 break;
539 }
540
541 if (ACPI_SUCCESS(status)) {
542 if (read_write == ACPI_READ) {
543 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
544 "Value Read %8.8X%8.8X, Width %u\n",
545 ACPI_FORMAT_UINT64(*value),
546 obj_desc->common_field.
547 access_byte_width));
548 } else {
549 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
550 "Value Written %8.8X%8.8X, Width %u\n",
551 ACPI_FORMAT_UINT64(*value),
552 obj_desc->common_field.
553 access_byte_width));
554 }
555 }
556
557 return_ACPI_STATUS(status);
558 }
559
560 /*******************************************************************************
561 *
562 * FUNCTION: acpi_ex_write_with_update_rule
563 *
564 * PARAMETERS: obj_desc - Field to be written
565 * mask - bitmask within field datum
566 * field_value - Value to write
567 * field_datum_byte_offset - Offset of datum within field
568 *
569 * RETURN: Status
570 *
571 * DESCRIPTION: Apply the field update rule to a field write
572 *
573 ******************************************************************************/
574
575 acpi_status
576 acpi_ex_write_with_update_rule(union acpi_operand_object *obj_desc,
577 u64 mask,
578 u64 field_value, u32 field_datum_byte_offset)
579 {
580 acpi_status status = AE_OK;
581 u64 merged_value;
582 u64 current_value;
583
584 ACPI_FUNCTION_TRACE_U32(ex_write_with_update_rule, mask);
585
586 /* Start with the new bits */
587
588 merged_value = field_value;
589
590 /* If the mask is all ones, we don't need to worry about the update rule */
591
592 if (mask != ACPI_UINT64_MAX) {
593
594 /* Decode the update rule */
595
596 switch (obj_desc->common_field.
597 field_flags & AML_FIELD_UPDATE_RULE_MASK) {
598 case AML_FIELD_UPDATE_PRESERVE:
599 /*
600 * Check if update rule needs to be applied (not if mask is all
601 * ones) The left shift drops the bits we want to ignore.
602 */
603 if ((~mask << (ACPI_MUL_8(sizeof(mask)) -
604 ACPI_MUL_8(obj_desc->common_field.
605 access_byte_width))) != 0) {
606 /*
607 * Read the current contents of the byte/word/dword containing
608 * the field, and merge with the new field value.
609 */
610 status =
611 acpi_ex_field_datum_io(obj_desc,
612 field_datum_byte_offset,
613 &current_value,
614 ACPI_READ);
615 if (ACPI_FAILURE(status)) {
616 return_ACPI_STATUS(status);
617 }
618
619 merged_value |= (current_value & ~mask);
620 }
621 break;
622
623 case AML_FIELD_UPDATE_WRITE_AS_ONES:
624
625 /* Set positions outside the field to all ones */
626
627 merged_value |= ~mask;
628 break;
629
630 case AML_FIELD_UPDATE_WRITE_AS_ZEROS:
631
632 /* Set positions outside the field to all zeros */
633
634 merged_value &= mask;
635 break;
636
637 default:
638
639 ACPI_ERROR((AE_INFO,
640 "Unknown UpdateRule value: 0x%X",
641 (obj_desc->common_field.
642 field_flags &
643 AML_FIELD_UPDATE_RULE_MASK)));
644 return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
645 }
646 }
647
648 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
649 "Mask %8.8X%8.8X, DatumOffset %X, Width %X, Value %8.8X%8.8X, MergedValue %8.8X%8.8X\n",
650 ACPI_FORMAT_UINT64(mask),
651 field_datum_byte_offset,
652 obj_desc->common_field.access_byte_width,
653 ACPI_FORMAT_UINT64(field_value),
654 ACPI_FORMAT_UINT64(merged_value)));
655
656 /* Write the merged value */
657
658 status = acpi_ex_field_datum_io(obj_desc, field_datum_byte_offset,
659 &merged_value, ACPI_WRITE);
660
661 return_ACPI_STATUS(status);
662 }
663
664 /*******************************************************************************
665 *
666 * FUNCTION: acpi_ex_extract_from_field
667 *
668 * PARAMETERS: obj_desc - Field to be read
669 * buffer - Where to store the field data
670 * buffer_length - Length of Buffer
671 *
672 * RETURN: Status
673 *
674 * DESCRIPTION: Retrieve the current value of the given field
675 *
676 ******************************************************************************/
677
678 acpi_status
679 acpi_ex_extract_from_field(union acpi_operand_object *obj_desc,
680 void *buffer, u32 buffer_length)
681 {
682 acpi_status status;
683 u64 raw_datum;
684 u64 merged_datum;
685 u32 field_offset = 0;
686 u32 buffer_offset = 0;
687 u32 buffer_tail_bits;
688 u32 datum_count;
689 u32 field_datum_count;
690 u32 access_bit_width;
691 u32 i;
692
693 ACPI_FUNCTION_TRACE(ex_extract_from_field);
694
695 /* Validate target buffer and clear it */
696
697 if (buffer_length <
698 ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length)) {
699 ACPI_ERROR((AE_INFO,
700 "Field size %u (bits) is too large for buffer (%u)",
701 obj_desc->common_field.bit_length, buffer_length));
702
703 return_ACPI_STATUS(AE_BUFFER_OVERFLOW);
704 }
705
706 memset(buffer, 0, buffer_length);
707 access_bit_width = ACPI_MUL_8(obj_desc->common_field.access_byte_width);
708
709 /* Handle the simple case here */
710
711 if ((obj_desc->common_field.start_field_bit_offset == 0) &&
712 (obj_desc->common_field.bit_length == access_bit_width)) {
713 if (buffer_length >= sizeof(u64)) {
714 status =
715 acpi_ex_field_datum_io(obj_desc, 0, buffer,
716 ACPI_READ);
717 } else {
718 /* Use raw_datum (u64) to handle buffers < 64 bits */
719
720 status =
721 acpi_ex_field_datum_io(obj_desc, 0, &raw_datum,
722 ACPI_READ);
723 memcpy(buffer, &raw_datum, buffer_length);
724 }
725
726 return_ACPI_STATUS(status);
727 }
728
729 /* TBD: Move to common setup code */
730
731 /* Field algorithm is limited to sizeof(u64), truncate if needed */
732
733 if (obj_desc->common_field.access_byte_width > sizeof(u64)) {
734 obj_desc->common_field.access_byte_width = sizeof(u64);
735 access_bit_width = sizeof(u64) * 8;
736 }
737
738 /* Compute the number of datums (access width data items) */
739
740 datum_count =
741 ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
742 access_bit_width);
743
744 field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
745 obj_desc->common_field.
746 start_field_bit_offset,
747 access_bit_width);
748
749 /* Priming read from the field */
750
751 status =
752 acpi_ex_field_datum_io(obj_desc, field_offset, &raw_datum,
753 ACPI_READ);
754 if (ACPI_FAILURE(status)) {
755 return_ACPI_STATUS(status);
756 }
757 merged_datum =
758 raw_datum >> obj_desc->common_field.start_field_bit_offset;
759
760 /* Read the rest of the field */
761
762 for (i = 1; i < field_datum_count; i++) {
763
764 /* Get next input datum from the field */
765
766 field_offset += obj_desc->common_field.access_byte_width;
767 status = acpi_ex_field_datum_io(obj_desc, field_offset,
768 &raw_datum, ACPI_READ);
769 if (ACPI_FAILURE(status)) {
770 return_ACPI_STATUS(status);
771 }
772
773 /*
774 * Merge with previous datum if necessary.
775 *
776 * Note: Before the shift, check if the shift value will be larger than
777 * the integer size. If so, there is no need to perform the operation.
778 * This avoids the differences in behavior between different compilers
779 * concerning shift values larger than the target data width.
780 */
781 if (access_bit_width -
782 obj_desc->common_field.start_field_bit_offset <
783 ACPI_INTEGER_BIT_SIZE) {
784 merged_datum |=
785 raw_datum << (access_bit_width -
786 obj_desc->common_field.
787 start_field_bit_offset);
788 }
789
790 if (i == datum_count) {
791 break;
792 }
793
794 /* Write merged datum to target buffer */
795
796 memcpy(((char *)buffer) + buffer_offset, &merged_datum,
797 ACPI_MIN(obj_desc->common_field.access_byte_width,
798 buffer_length - buffer_offset));
799
800 buffer_offset += obj_desc->common_field.access_byte_width;
801 merged_datum =
802 raw_datum >> obj_desc->common_field.start_field_bit_offset;
803 }
804
805 /* Mask off any extra bits in the last datum */
806
807 buffer_tail_bits = obj_desc->common_field.bit_length % access_bit_width;
808 if (buffer_tail_bits) {
809 merged_datum &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
810 }
811
812 /* Write the last datum to the buffer */
813
814 memcpy(((char *)buffer) + buffer_offset, &merged_datum,
815 ACPI_MIN(obj_desc->common_field.access_byte_width,
816 buffer_length - buffer_offset));
817
818 return_ACPI_STATUS(AE_OK);
819 }
820
821 /*******************************************************************************
822 *
823 * FUNCTION: acpi_ex_insert_into_field
824 *
825 * PARAMETERS: obj_desc - Field to be written
826 * buffer - Data to be written
827 * buffer_length - Length of Buffer
828 *
829 * RETURN: Status
830 *
831 * DESCRIPTION: Store the Buffer contents into the given field
832 *
833 ******************************************************************************/
834
835 acpi_status
836 acpi_ex_insert_into_field(union acpi_operand_object *obj_desc,
837 void *buffer, u32 buffer_length)
838 {
839 void *new_buffer;
840 acpi_status status;
841 u64 mask;
842 u64 width_mask;
843 u64 merged_datum;
844 u64 raw_datum = 0;
845 u32 field_offset = 0;
846 u32 buffer_offset = 0;
847 u32 buffer_tail_bits;
848 u32 datum_count;
849 u32 field_datum_count;
850 u32 access_bit_width;
851 u32 required_length;
852 u32 i;
853
854 ACPI_FUNCTION_TRACE(ex_insert_into_field);
855
856 /* Validate input buffer */
857
858 new_buffer = NULL;
859 required_length =
860 ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length);
861 /*
862 * We must have a buffer that is at least as long as the field
863 * we are writing to. This is because individual fields are
864 * indivisible and partial writes are not supported -- as per
865 * the ACPI specification.
866 */
867 if (buffer_length < required_length) {
868
869 /* We need to create a new buffer */
870
871 new_buffer = ACPI_ALLOCATE_ZEROED(required_length);
872 if (!new_buffer) {
873 return_ACPI_STATUS(AE_NO_MEMORY);
874 }
875
876 /*
877 * Copy the original data to the new buffer, starting
878 * at Byte zero. All unused (upper) bytes of the
879 * buffer will be 0.
880 */
881 memcpy((char *)new_buffer, (char *)buffer, buffer_length);
882 buffer = new_buffer;
883 buffer_length = required_length;
884 }
885
886 /* TBD: Move to common setup code */
887
888 /* Algo is limited to sizeof(u64), so cut the access_byte_width */
889 if (obj_desc->common_field.access_byte_width > sizeof(u64)) {
890 obj_desc->common_field.access_byte_width = sizeof(u64);
891 }
892
893 access_bit_width = ACPI_MUL_8(obj_desc->common_field.access_byte_width);
894
895 /*
896 * Create the bitmasks used for bit insertion.
897 * Note: This if/else is used to bypass compiler differences with the
898 * shift operator
899 */
900 if (access_bit_width == ACPI_INTEGER_BIT_SIZE) {
901 width_mask = ACPI_UINT64_MAX;
902 } else {
903 width_mask = ACPI_MASK_BITS_ABOVE(access_bit_width);
904 }
905
906 mask = width_mask &
907 ACPI_MASK_BITS_BELOW(obj_desc->common_field.start_field_bit_offset);
908
909 /* Compute the number of datums (access width data items) */
910
911 datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length,
912 access_bit_width);
913
914 field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length +
915 obj_desc->common_field.
916 start_field_bit_offset,
917 access_bit_width);
918
919 /* Get initial Datum from the input buffer */
920
921 memcpy(&raw_datum, buffer,
922 ACPI_MIN(obj_desc->common_field.access_byte_width,
923 buffer_length - buffer_offset));
924
925 merged_datum =
926 raw_datum << obj_desc->common_field.start_field_bit_offset;
927
928 /* Write the entire field */
929
930 for (i = 1; i < field_datum_count; i++) {
931
932 /* Write merged datum to the target field */
933
934 merged_datum &= mask;
935 status = acpi_ex_write_with_update_rule(obj_desc, mask,
936 merged_datum,
937 field_offset);
938 if (ACPI_FAILURE(status)) {
939 goto exit;
940 }
941
942 field_offset += obj_desc->common_field.access_byte_width;
943
944 /*
945 * Start new output datum by merging with previous input datum
946 * if necessary.
947 *
948 * Note: Before the shift, check if the shift value will be larger than
949 * the integer size. If so, there is no need to perform the operation.
950 * This avoids the differences in behavior between different compilers
951 * concerning shift values larger than the target data width.
952 */
953 if ((access_bit_width -
954 obj_desc->common_field.start_field_bit_offset) <
955 ACPI_INTEGER_BIT_SIZE) {
956 merged_datum =
957 raw_datum >> (access_bit_width -
958 obj_desc->common_field.
959 start_field_bit_offset);
960 } else {
961 merged_datum = 0;
962 }
963
964 mask = width_mask;
965
966 if (i == datum_count) {
967 break;
968 }
969
970 /* Get the next input datum from the buffer */
971
972 buffer_offset += obj_desc->common_field.access_byte_width;
973 memcpy(&raw_datum, ((char *)buffer) + buffer_offset,
974 ACPI_MIN(obj_desc->common_field.access_byte_width,
975 buffer_length - buffer_offset));
976
977 merged_datum |=
978 raw_datum << obj_desc->common_field.start_field_bit_offset;
979 }
980
981 /* Mask off any extra bits in the last datum */
982
983 buffer_tail_bits = (obj_desc->common_field.bit_length +
984 obj_desc->common_field.start_field_bit_offset) %
985 access_bit_width;
986 if (buffer_tail_bits) {
987 mask &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits);
988 }
989
990 /* Write the last datum to the field */
991
992 merged_datum &= mask;
993 status = acpi_ex_write_with_update_rule(obj_desc,
994 mask, merged_datum,
995 field_offset);
996
997 exit:
998 /* Free temporary buffer if we used one */
999
1000 if (new_buffer) {
1001 ACPI_FREE(new_buffer);
1002 }
1003 return_ACPI_STATUS(status);
1004 }
Linux kernel - Deliverables
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