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
45 #define __EXFLDIO_C__
46
47 #include "acpi.h"
48 #include "accommon.h"
49 #include "acinterp.h"
50 #include "amlcode.h"
51 #include "acevents.h"
52 #include "acdispat.h"
53
54
55 #define _COMPONENT ACPI_EXECUTER
56 ACPI_MODULE_NAME ("exfldio")
57
58 /* Local prototypes */
59
60 static ACPI_STATUS
61 AcpiExFieldDatumIo (
62 ACPI_OPERAND_OBJECT *ObjDesc,
63 UINT32 FieldDatumByteOffset,
64 UINT64 *Value,
65 UINT32 ReadWrite);
66
67 static BOOLEAN
68 AcpiExRegisterOverflow (
69 ACPI_OPERAND_OBJECT *ObjDesc,
70 UINT64 Value);
71
72 static ACPI_STATUS
73 AcpiExSetupRegion (
74 ACPI_OPERAND_OBJECT *ObjDesc,
75 UINT32 FieldDatumByteOffset);
76
77
78 /*******************************************************************************
79 *
80 * FUNCTION: AcpiExSetupRegion
81 *
82 * PARAMETERS: ObjDesc - Field to be read or written
83 * FieldDatumByteOffset - Byte offset of this datum within the
84 * parent field
85 *
86 * RETURN: Status
87 *
88 * DESCRIPTION: Common processing for AcpiExExtractFromField and
89 * AcpiExInsertIntoField. Initialize the Region if necessary and
90 * validate the request.
91 *
92 ******************************************************************************/
93
94 static ACPI_STATUS
95 AcpiExSetupRegion (
96 ACPI_OPERAND_OBJECT *ObjDesc,
97 UINT32 FieldDatumByteOffset)
98 {
99 ACPI_STATUS Status = AE_OK;
100 ACPI_OPERAND_OBJECT *RgnDesc;
101
102
103 ACPI_FUNCTION_TRACE_U32 (ExSetupRegion, FieldDatumByteOffset);
104
105
106 RgnDesc = ObjDesc->CommonField.RegionObj;
107
108 /* We must have a valid region */
109
110 if (RgnDesc->Common.Type != ACPI_TYPE_REGION)
111 {
112 ACPI_ERROR ((AE_INFO, "Needed Region, found type 0x%X (%s)",
113 RgnDesc->Common.Type,
114 AcpiUtGetObjectTypeName (RgnDesc)));
115
116 return_ACPI_STATUS (AE_AML_OPERAND_TYPE);
117 }
118
119 /*
120 * If the Region Address and Length have not been previously evaluated,
121 * evaluate them now and save the results.
122 */
123 if (!(RgnDesc->Common.Flags & AOPOBJ_DATA_VALID))
124 {
125 Status = AcpiDsGetRegionArguments (RgnDesc);
126 if (ACPI_FAILURE (Status))
127 {
128 return_ACPI_STATUS (Status);
129 }
130 }
131
132 /*
133 * Exit now for SMBus or IPMI address space, it has a non-linear
134 * address space and the request cannot be directly validated
135 */
136 if (RgnDesc->Region.SpaceId == ACPI_ADR_SPACE_SMBUS ||
137 RgnDesc->Region.SpaceId == ACPI_ADR_SPACE_IPMI)
138 {
139 /* SMBus or IPMI has a non-linear address space */
140
141 return_ACPI_STATUS (AE_OK);
142 }
143
144 #ifdef ACPI_UNDER_DEVELOPMENT
145 /*
146 * If the Field access is AnyAcc, we can now compute the optimal
147 * access (because we know know the length of the parent region)
148 */
149 if (!(ObjDesc->Common.Flags & AOPOBJ_DATA_VALID))
150 {
151 if (ACPI_FAILURE (Status))
152 {
153 return_ACPI_STATUS (Status);
154 }
155 }
156 #endif
157
158 /*
159 * Validate the request. The entire request from the byte offset for a
160 * length of one field datum (access width) must fit within the region.
161 * (Region length is specified in bytes)
162 */
163 if (RgnDesc->Region.Length <
164 (ObjDesc->CommonField.BaseByteOffset + FieldDatumByteOffset +
165 ObjDesc->CommonField.AccessByteWidth))
166 {
167 if (AcpiGbl_EnableInterpreterSlack)
168 {
169 /*
170 * Slack mode only: We will go ahead and allow access to this
171 * field if it is within the region length rounded up to the next
172 * access width boundary. ACPI_SIZE cast for 64-bit compile.
173 */
174 if (ACPI_ROUND_UP (RgnDesc->Region.Length,
175 ObjDesc->CommonField.AccessByteWidth) >=
176 ((ACPI_SIZE) ObjDesc->CommonField.BaseByteOffset +
177 ObjDesc->CommonField.AccessByteWidth +
178 FieldDatumByteOffset))
179 {
180 return_ACPI_STATUS (AE_OK);
181 }
182 }
183
184 if (RgnDesc->Region.Length < ObjDesc->CommonField.AccessByteWidth)
185 {
186 /*
187 * This is the case where the AccessType (AccWord, etc.) is wider
188 * than the region itself. For example, a region of length one
189 * byte, and a field with Dword access specified.
190 */
191 ACPI_ERROR ((AE_INFO,
192 "Field [%4.4s] access width (%u bytes) too large for region [%4.4s] (length %u)",
193 AcpiUtGetNodeName (ObjDesc->CommonField.Node),
194 ObjDesc->CommonField.AccessByteWidth,
195 AcpiUtGetNodeName (RgnDesc->Region.Node),
196 RgnDesc->Region.Length));
197 }
198
199 /*
200 * Offset rounded up to next multiple of field width
201 * exceeds region length, indicate an error
202 */
203 ACPI_ERROR ((AE_INFO,
204 "Field [%4.4s] Base+Offset+Width %u+%u+%u is beyond end of region [%4.4s] (length %u)",
205 AcpiUtGetNodeName (ObjDesc->CommonField.Node),
206 ObjDesc->CommonField.BaseByteOffset,
207 FieldDatumByteOffset, ObjDesc->CommonField.AccessByteWidth,
208 AcpiUtGetNodeName (RgnDesc->Region.Node),
209 RgnDesc->Region.Length));
210
211 return_ACPI_STATUS (AE_AML_REGION_LIMIT);
212 }
213
214 return_ACPI_STATUS (AE_OK);
215 }
216
217
218 /*******************************************************************************
219 *
220 * FUNCTION: AcpiExAccessRegion
221 *
222 * PARAMETERS: ObjDesc - Field to be read
223 * FieldDatumByteOffset - Byte offset of this datum within the
224 * parent field
225 * Value - Where to store value (must at least
226 * 64 bits)
227 * Function - Read or Write flag plus other region-
228 * dependent flags
229 *
230 * RETURN: Status
231 *
232 * DESCRIPTION: Read or Write a single field datum to an Operation Region.
233 *
234 ******************************************************************************/
235
236 ACPI_STATUS
237 AcpiExAccessRegion (
238 ACPI_OPERAND_OBJECT *ObjDesc,
239 UINT32 FieldDatumByteOffset,
240 UINT64 *Value,
241 UINT32 Function)
242 {
243 ACPI_STATUS Status;
244 ACPI_OPERAND_OBJECT *RgnDesc;
245 UINT32 RegionOffset;
246
247
248 ACPI_FUNCTION_TRACE (ExAccessRegion);
249
250
251 /*
252 * Ensure that the region operands are fully evaluated and verify
253 * the validity of the request
254 */
255 Status = AcpiExSetupRegion (ObjDesc, FieldDatumByteOffset);
256 if (ACPI_FAILURE (Status))
257 {
258 return_ACPI_STATUS (Status);
259 }
260
261 /*
262 * The physical address of this field datum is:
263 *
264 * 1) The base of the region, plus
265 * 2) The base offset of the field, plus
266 * 3) The current offset into the field
267 */
268 RgnDesc = ObjDesc->CommonField.RegionObj;
269 RegionOffset =
270 ObjDesc->CommonField.BaseByteOffset +
271 FieldDatumByteOffset;
272
273 if ((Function & ACPI_IO_MASK) == ACPI_READ)
274 {
275 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD, "[READ]"));
276 }
277 else
278 {
279 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD, "[WRITE]"));
280 }
281
282 ACPI_DEBUG_PRINT_RAW ((ACPI_DB_BFIELD,
283 " Region [%s:%X], Width %X, ByteBase %X, Offset %X at %p\n",
284 AcpiUtGetRegionName (RgnDesc->Region.SpaceId),
285 RgnDesc->Region.SpaceId,
286 ObjDesc->CommonField.AccessByteWidth,
287 ObjDesc->CommonField.BaseByteOffset,
288 FieldDatumByteOffset,
289 ACPI_CAST_PTR (void, (RgnDesc->Region.Address + RegionOffset))));
290
291 /* Invoke the appropriate AddressSpace/OpRegion handler */
292
293 Status = AcpiEvAddressSpaceDispatch (RgnDesc, Function, RegionOffset,
294 ACPI_MUL_8 (ObjDesc->CommonField.AccessByteWidth), Value);
295
296 if (ACPI_FAILURE (Status))
297 {
298 if (Status == AE_NOT_IMPLEMENTED)
299 {
300 ACPI_ERROR ((AE_INFO,
301 "Region %s (ID=%u) not implemented",
302 AcpiUtGetRegionName (RgnDesc->Region.SpaceId),
303 RgnDesc->Region.SpaceId));
304 }
305 else if (Status == AE_NOT_EXIST)
306 {
307 ACPI_ERROR ((AE_INFO,
308 "Region %s (ID=%u) has no handler",
309 AcpiUtGetRegionName (RgnDesc->Region.SpaceId),
310 RgnDesc->Region.SpaceId));
311 }
312 }
313
314 return_ACPI_STATUS (Status);
315 }
316
317
318 /*******************************************************************************
319 *
320 * FUNCTION: AcpiExRegisterOverflow
321 *
322 * PARAMETERS: ObjDesc - Register(Field) to be written
323 * Value - Value to be stored
324 *
325 * RETURN: TRUE if value overflows the field, FALSE otherwise
326 *
327 * DESCRIPTION: Check if a value is out of range of the field being written.
328 * Used to check if the values written to Index and Bank registers
329 * are out of range. Normally, the value is simply truncated
330 * to fit the field, but this case is most likely a serious
331 * coding error in the ASL.
332 *
333 ******************************************************************************/
334
335 static BOOLEAN
336 AcpiExRegisterOverflow (
337 ACPI_OPERAND_OBJECT *ObjDesc,
338 UINT64 Value)
339 {
340
341 if (ObjDesc->CommonField.BitLength >= ACPI_INTEGER_BIT_SIZE)
342 {
343 /*
344 * The field is large enough to hold the maximum integer, so we can
345 * never overflow it.
346 */
347 return (FALSE);
348 }
349
350 if (Value >= ((UINT64) 1 << ObjDesc->CommonField.BitLength))
351 {
352 /*
353 * The Value is larger than the maximum value that can fit into
354 * the register.
355 */
356 return (TRUE);
357 }
358
359 /* The Value will fit into the field with no truncation */
360
361 return (FALSE);
362 }
363
364
365 /*******************************************************************************
366 *
367 * FUNCTION: AcpiExFieldDatumIo
368 *
369 * PARAMETERS: ObjDesc - Field to be read
370 * FieldDatumByteOffset - Byte offset of this datum within the
371 * parent field
372 * Value - Where to store value (must be 64 bits)
373 * ReadWrite - Read or Write flag
374 *
375 * RETURN: Status
376 *
377 * DESCRIPTION: Read or Write a single datum of a field. The FieldType is
378 * demultiplexed here to handle the different types of fields
379 * (BufferField, RegionField, IndexField, BankField)
380 *
381 ******************************************************************************/
382
383 static ACPI_STATUS
384 AcpiExFieldDatumIo (
385 ACPI_OPERAND_OBJECT *ObjDesc,
386 UINT32 FieldDatumByteOffset,
387 UINT64 *Value,
388 UINT32 ReadWrite)
389 {
390 ACPI_STATUS Status;
391 UINT64 LocalValue;
392
393
394 ACPI_FUNCTION_TRACE_U32 (ExFieldDatumIo, FieldDatumByteOffset);
395
396
397 if (ReadWrite == ACPI_READ)
398 {
399 if (!Value)
400 {
401 LocalValue = 0;
402
403 /* To support reads without saving return value */
404 Value = &LocalValue;
405 }
406
407 /* Clear the entire return buffer first, [Very Important!] */
408
409 *Value = 0;
410 }
411
412 /*
413 * The four types of fields are:
414 *
415 * BufferField - Read/write from/to a Buffer
416 * RegionField - Read/write from/to a Operation Region.
417 * BankField - Write to a Bank Register, then read/write from/to an
418 * OperationRegion
419 * IndexField - Write to an Index Register, then read/write from/to a
420 * Data Register
421 */
422 switch (ObjDesc->Common.Type)
423 {
424 case ACPI_TYPE_BUFFER_FIELD:
425 /*
426 * If the BufferField arguments have not been previously evaluated,
427 * evaluate them now and save the results.
428 */
429 if (!(ObjDesc->Common.Flags & AOPOBJ_DATA_VALID))
430 {
431 Status = AcpiDsGetBufferFieldArguments (ObjDesc);
432 if (ACPI_FAILURE (Status))
433 {
434 return_ACPI_STATUS (Status);
435 }
436 }
437
438 if (ReadWrite == ACPI_READ)
439 {
440 /*
441 * Copy the data from the source buffer.
442 * Length is the field width in bytes.
443 */
444 ACPI_MEMCPY (Value,
445 (ObjDesc->BufferField.BufferObj)->Buffer.Pointer +
446 ObjDesc->BufferField.BaseByteOffset +
447 FieldDatumByteOffset,
448 ObjDesc->CommonField.AccessByteWidth);
449 }
450 else
451 {
452 /*
453 * Copy the data to the target buffer.
454 * Length is the field width in bytes.
455 */
456 ACPI_MEMCPY ((ObjDesc->BufferField.BufferObj)->Buffer.Pointer +
457 ObjDesc->BufferField.BaseByteOffset +
458 FieldDatumByteOffset,
459 Value, ObjDesc->CommonField.AccessByteWidth);
460 }
461
462 Status = AE_OK;
463 break;
464
465
466 case ACPI_TYPE_LOCAL_BANK_FIELD:
467
468 /*
469 * Ensure that the BankValue is not beyond the capacity of
470 * the register
471 */
472 if (AcpiExRegisterOverflow (ObjDesc->BankField.BankObj,
473 (UINT64) ObjDesc->BankField.Value))
474 {
475 return_ACPI_STATUS (AE_AML_REGISTER_LIMIT);
476 }
477
478 /*
479 * For BankFields, we must write the BankValue to the BankRegister
480 * (itself a RegionField) before we can access the data.
481 */
482 Status = AcpiExInsertIntoField (ObjDesc->BankField.BankObj,
483 &ObjDesc->BankField.Value,
484 sizeof (ObjDesc->BankField.Value));
485 if (ACPI_FAILURE (Status))
486 {
487 return_ACPI_STATUS (Status);
488 }
489
490 /*
491 * Now that the Bank has been selected, fall through to the
492 * RegionField case and write the datum to the Operation Region
493 */
494
495 /*lint -fallthrough */
496
497
498 case ACPI_TYPE_LOCAL_REGION_FIELD:
499 /*
500 * For simple RegionFields, we just directly access the owning
501 * Operation Region.
502 */
503 Status = AcpiExAccessRegion (ObjDesc, FieldDatumByteOffset, Value,
504 ReadWrite);
505 break;
506
507
508 case ACPI_TYPE_LOCAL_INDEX_FIELD:
509
510
511 /*
512 * Ensure that the IndexValue is not beyond the capacity of
513 * the register
514 */
515 if (AcpiExRegisterOverflow (ObjDesc->IndexField.IndexObj,
516 (UINT64) ObjDesc->IndexField.Value))
517 {
518 return_ACPI_STATUS (AE_AML_REGISTER_LIMIT);
519 }
520
521 /* Write the index value to the IndexRegister (itself a RegionField) */
522
523 FieldDatumByteOffset += ObjDesc->IndexField.Value;
524
525 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
526 "Write to Index Register: Value %8.8X\n",
527 FieldDatumByteOffset));
528
529 Status = AcpiExInsertIntoField (ObjDesc->IndexField.IndexObj,
530 &FieldDatumByteOffset,
531 sizeof (FieldDatumByteOffset));
532 if (ACPI_FAILURE (Status))
533 {
534 return_ACPI_STATUS (Status);
535 }
536
537 if (ReadWrite == ACPI_READ)
538 {
539 /* Read the datum from the DataRegister */
540
541 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
542 "Read from Data Register\n"));
543
544 Status = AcpiExExtractFromField (ObjDesc->IndexField.DataObj,
545 Value, sizeof (UINT64));
546 }
547 else
548 {
549 /* Write the datum to the DataRegister */
550
551 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
552 "Write to Data Register: Value %8.8X%8.8X\n",
553 ACPI_FORMAT_UINT64 (*Value)));
554
555 Status = AcpiExInsertIntoField (ObjDesc->IndexField.DataObj,
556 Value, sizeof (UINT64));
557 }
558 break;
559
560
561 default:
562
563 ACPI_ERROR ((AE_INFO, "Wrong object type in field I/O %u",
564 ObjDesc->Common.Type));
565 Status = AE_AML_INTERNAL;
566 break;
567 }
568
569 if (ACPI_SUCCESS (Status))
570 {
571 if (ReadWrite == ACPI_READ)
572 {
573 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
574 "Value Read %8.8X%8.8X, Width %u\n",
575 ACPI_FORMAT_UINT64 (*Value),
576 ObjDesc->CommonField.AccessByteWidth));
577 }
578 else
579 {
580 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
581 "Value Written %8.8X%8.8X, Width %u\n",
582 ACPI_FORMAT_UINT64 (*Value),
583 ObjDesc->CommonField.AccessByteWidth));
584 }
585 }
586
587 return_ACPI_STATUS (Status);
588 }
589
590
591 /*******************************************************************************
592 *
593 * FUNCTION: AcpiExWriteWithUpdateRule
594 *
595 * PARAMETERS: ObjDesc - Field to be written
596 * Mask - bitmask within field datum
597 * FieldValue - Value to write
598 * FieldDatumByteOffset - Offset of datum within field
599 *
600 * RETURN: Status
601 *
602 * DESCRIPTION: Apply the field update rule to a field write
603 *
604 ******************************************************************************/
605
606 ACPI_STATUS
607 AcpiExWriteWithUpdateRule (
608 ACPI_OPERAND_OBJECT *ObjDesc,
609 UINT64 Mask,
610 UINT64 FieldValue,
611 UINT32 FieldDatumByteOffset)
612 {
613 ACPI_STATUS Status = AE_OK;
614 UINT64 MergedValue;
615 UINT64 CurrentValue;
616
617
618 ACPI_FUNCTION_TRACE_U32 (ExWriteWithUpdateRule, Mask);
619
620
621 /* Start with the new bits */
622
623 MergedValue = FieldValue;
624
625 /* If the mask is all ones, we don't need to worry about the update rule */
626
627 if (Mask != ACPI_UINT64_MAX)
628 {
629 /* Decode the update rule */
630
631 switch (ObjDesc->CommonField.FieldFlags & AML_FIELD_UPDATE_RULE_MASK)
632 {
633 case AML_FIELD_UPDATE_PRESERVE:
634 /*
635 * Check if update rule needs to be applied (not if mask is all
636 * ones) The left shift drops the bits we want to ignore.
637 */
638 if ((~Mask << (ACPI_MUL_8 (sizeof (Mask)) -
639 ACPI_MUL_8 (ObjDesc->CommonField.AccessByteWidth))) != 0)
640 {
641 /*
642 * Read the current contents of the byte/word/dword containing
643 * the field, and merge with the new field value.
644 */
645 Status = AcpiExFieldDatumIo (ObjDesc, FieldDatumByteOffset,
646 &CurrentValue, ACPI_READ);
647 if (ACPI_FAILURE (Status))
648 {
649 return_ACPI_STATUS (Status);
650 }
651
652 MergedValue |= (CurrentValue & ~Mask);
653 }
654 break;
655
656 case AML_FIELD_UPDATE_WRITE_AS_ONES:
657
658 /* Set positions outside the field to all ones */
659
660 MergedValue |= ~Mask;
661 break;
662
663 case AML_FIELD_UPDATE_WRITE_AS_ZEROS:
664
665 /* Set positions outside the field to all zeros */
666
667 MergedValue &= Mask;
668 break;
669
670 default:
671
672 ACPI_ERROR ((AE_INFO,
673 "Unknown UpdateRule value: 0x%X",
674 (ObjDesc->CommonField.FieldFlags & AML_FIELD_UPDATE_RULE_MASK)));
675 return_ACPI_STATUS (AE_AML_OPERAND_VALUE);
676 }
677 }
678
679 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
680 "Mask %8.8X%8.8X, DatumOffset %X, Width %X, Value %8.8X%8.8X, MergedValue %8.8X%8.8X\n",
681 ACPI_FORMAT_UINT64 (Mask),
682 FieldDatumByteOffset,
683 ObjDesc->CommonField.AccessByteWidth,
684 ACPI_FORMAT_UINT64 (FieldValue),
685 ACPI_FORMAT_UINT64 (MergedValue)));
686
687 /* Write the merged value */
688
689 Status = AcpiExFieldDatumIo (ObjDesc, FieldDatumByteOffset,
690 &MergedValue, ACPI_WRITE);
691
692 return_ACPI_STATUS (Status);
693 }
694
695
696 /*******************************************************************************
697 *
698 * FUNCTION: AcpiExExtractFromField
699 *
700 * PARAMETERS: ObjDesc - Field to be read
701 * Buffer - Where to store the field data
702 * BufferLength - Length of Buffer
703 *
704 * RETURN: Status
705 *
706 * DESCRIPTION: Retrieve the current value of the given field
707 *
708 ******************************************************************************/
709
710 ACPI_STATUS
711 AcpiExExtractFromField (
712 ACPI_OPERAND_OBJECT *ObjDesc,
713 void *Buffer,
714 UINT32 BufferLength)
715 {
716 ACPI_STATUS Status;
717 UINT64 RawDatum;
718 UINT64 MergedDatum;
719 UINT32 FieldOffset = 0;
720 UINT32 BufferOffset = 0;
721 UINT32 BufferTailBits;
722 UINT32 DatumCount;
723 UINT32 FieldDatumCount;
724 UINT32 AccessBitWidth;
725 UINT32 i;
726
727
728 ACPI_FUNCTION_TRACE (ExExtractFromField);
729
730
731 /* Validate target buffer and clear it */
732
733 if (BufferLength <
734 ACPI_ROUND_BITS_UP_TO_BYTES (ObjDesc->CommonField.BitLength))
735 {
736 ACPI_ERROR ((AE_INFO,
737 "Field size %u (bits) is too large for buffer (%u)",
738 ObjDesc->CommonField.BitLength, BufferLength));
739
740 return_ACPI_STATUS (AE_BUFFER_OVERFLOW);
741 }
742
743 ACPI_MEMSET (Buffer, 0, BufferLength);
744 AccessBitWidth = ACPI_MUL_8 (ObjDesc->CommonField.AccessByteWidth);
745
746 /* Handle the simple case here */
747
748 if ((ObjDesc->CommonField.StartFieldBitOffset == 0) &&
749 (ObjDesc->CommonField.BitLength == AccessBitWidth))
750 {
751 Status = AcpiExFieldDatumIo (ObjDesc, 0, Buffer, ACPI_READ);
752 return_ACPI_STATUS (Status);
753 }
754
755 /* TBD: Move to common setup code */
756
757 /* Field algorithm is limited to sizeof(UINT64), truncate if needed */
758
759 if (ObjDesc->CommonField.AccessByteWidth > sizeof (UINT64))
760 {
761 ObjDesc->CommonField.AccessByteWidth = sizeof (UINT64);
762 AccessBitWidth = sizeof (UINT64) * 8;
763 }
764
765 /* Compute the number of datums (access width data items) */
766
767 DatumCount = ACPI_ROUND_UP_TO (
768 ObjDesc->CommonField.BitLength, AccessBitWidth);
769
770 FieldDatumCount = ACPI_ROUND_UP_TO (
771 ObjDesc->CommonField.BitLength +
772 ObjDesc->CommonField.StartFieldBitOffset, AccessBitWidth);
773
774 /* Priming read from the field */
775
776 Status = AcpiExFieldDatumIo (ObjDesc, FieldOffset, &RawDatum, ACPI_READ);
777 if (ACPI_FAILURE (Status))
778 {
779 return_ACPI_STATUS (Status);
780 }
781 MergedDatum = RawDatum >> ObjDesc->CommonField.StartFieldBitOffset;
782
783 /* Read the rest of the field */
784
785 for (i = 1; i < FieldDatumCount; i++)
786 {
787 /* Get next input datum from the field */
788
789 FieldOffset += ObjDesc->CommonField.AccessByteWidth;
790 Status = AcpiExFieldDatumIo (ObjDesc, FieldOffset,
791 &RawDatum, ACPI_READ);
792 if (ACPI_FAILURE (Status))
793 {
794 return_ACPI_STATUS (Status);
795 }
796
797 /*
798 * Merge with previous datum if necessary.
799 *
800 * Note: Before the shift, check if the shift value will be larger than
801 * the integer size. If so, there is no need to perform the operation.
802 * This avoids the differences in behavior between different compilers
803 * concerning shift values larger than the target data width.
804 */
805 if (AccessBitWidth - ObjDesc->CommonField.StartFieldBitOffset <
806 ACPI_INTEGER_BIT_SIZE)
807 {
808 MergedDatum |= RawDatum <<
809 (AccessBitWidth - ObjDesc->CommonField.StartFieldBitOffset);
810 }
811
812 if (i == DatumCount)
813 {
814 break;
815 }
816
817 /* Write merged datum to target buffer */
818
819 ACPI_MEMCPY (((char *) Buffer) + BufferOffset, &MergedDatum,
820 ACPI_MIN(ObjDesc->CommonField.AccessByteWidth,
821 BufferLength - BufferOffset));
822
823 BufferOffset += ObjDesc->CommonField.AccessByteWidth;
824 MergedDatum = RawDatum >> ObjDesc->CommonField.StartFieldBitOffset;
825 }
826
827 /* Mask off any extra bits in the last datum */
828
829 BufferTailBits = ObjDesc->CommonField.BitLength % AccessBitWidth;
830 if (BufferTailBits)
831 {
832 MergedDatum &= ACPI_MASK_BITS_ABOVE (BufferTailBits);
833 }
834
835 /* Write the last datum to the buffer */
836
837 ACPI_MEMCPY (((char *) Buffer) + BufferOffset, &MergedDatum,
838 ACPI_MIN(ObjDesc->CommonField.AccessByteWidth,
839 BufferLength - BufferOffset));
840
841 return_ACPI_STATUS (AE_OK);
842 }
843
844
845 /*******************************************************************************
846 *
847 * FUNCTION: AcpiExInsertIntoField
848 *
849 * PARAMETERS: ObjDesc - Field to be written
850 * Buffer - Data to be written
851 * BufferLength - Length of Buffer
852 *
853 * RETURN: Status
854 *
855 * DESCRIPTION: Store the Buffer contents into the given field
856 *
857 ******************************************************************************/
858
859 ACPI_STATUS
860 AcpiExInsertIntoField (
861 ACPI_OPERAND_OBJECT *ObjDesc,
862 void *Buffer,
863 UINT32 BufferLength)
864 {
865 void *NewBuffer;
866 ACPI_STATUS Status;
867 UINT64 Mask;
868 UINT64 WidthMask;
869 UINT64 MergedDatum;
870 UINT64 RawDatum = 0;
871 UINT32 FieldOffset = 0;
872 UINT32 BufferOffset = 0;
873 UINT32 BufferTailBits;
874 UINT32 DatumCount;
875 UINT32 FieldDatumCount;
876 UINT32 AccessBitWidth;
877 UINT32 RequiredLength;
878 UINT32 i;
879
880
881 ACPI_FUNCTION_TRACE (ExInsertIntoField);
882
883
884 /* Validate input buffer */
885
886 NewBuffer = NULL;
887 RequiredLength = ACPI_ROUND_BITS_UP_TO_BYTES (
888 ObjDesc->CommonField.BitLength);
889 /*
890 * We must have a buffer that is at least as long as the field
891 * we are writing to. This is because individual fields are
892 * indivisible and partial writes are not supported -- as per
893 * the ACPI specification.
894 */
895 if (BufferLength < RequiredLength)
896 {
897 /* We need to create a new buffer */
898
899 NewBuffer = ACPI_ALLOCATE_ZEROED (RequiredLength);
900 if (!NewBuffer)
901 {
902 return_ACPI_STATUS (AE_NO_MEMORY);
903 }
904
905 /*
906 * Copy the original data to the new buffer, starting
907 * at Byte zero. All unused (upper) bytes of the
908 * buffer will be 0.
909 */
910 ACPI_MEMCPY ((char *) NewBuffer, (char *) Buffer, BufferLength);
911 Buffer = NewBuffer;
912 BufferLength = RequiredLength;
913 }
914
915 /* TBD: Move to common setup code */
916
917 /* Algo is limited to sizeof(UINT64), so cut the AccessByteWidth */
918 if (ObjDesc->CommonField.AccessByteWidth > sizeof (UINT64))
919 {
920 ObjDesc->CommonField.AccessByteWidth = sizeof (UINT64);
921 }
922
923 AccessBitWidth = ACPI_MUL_8 (ObjDesc->CommonField.AccessByteWidth);
924
925 /*
926 * Create the bitmasks used for bit insertion.
927 * Note: This if/else is used to bypass compiler differences with the
928 * shift operator
929 */
930 if (AccessBitWidth == ACPI_INTEGER_BIT_SIZE)
931 {
932 WidthMask = ACPI_UINT64_MAX;
933 }
934 else
935 {
936 WidthMask = ACPI_MASK_BITS_ABOVE (AccessBitWidth);
937 }
938
939 Mask = WidthMask &
940 ACPI_MASK_BITS_BELOW (ObjDesc->CommonField.StartFieldBitOffset);
941
942 /* Compute the number of datums (access width data items) */
943
944 DatumCount = ACPI_ROUND_UP_TO (ObjDesc->CommonField.BitLength,
945 AccessBitWidth);
946
947 FieldDatumCount = ACPI_ROUND_UP_TO (ObjDesc->CommonField.BitLength +
948 ObjDesc->CommonField.StartFieldBitOffset,
949 AccessBitWidth);
950
951 /* Get initial Datum from the input buffer */
952
953 ACPI_MEMCPY (&RawDatum, Buffer,
954 ACPI_MIN(ObjDesc->CommonField.AccessByteWidth,
955 BufferLength - BufferOffset));
956
957 MergedDatum = RawDatum << ObjDesc->CommonField.StartFieldBitOffset;
958
959 /* Write the entire field */
960
961 for (i = 1; i < FieldDatumCount; i++)
962 {
963 /* Write merged datum to the target field */
964
965 MergedDatum &= Mask;
966 Status = AcpiExWriteWithUpdateRule (ObjDesc, Mask,
967 MergedDatum, FieldOffset);
968 if (ACPI_FAILURE (Status))
969 {
970 goto Exit;
971 }
972
973 FieldOffset += ObjDesc->CommonField.AccessByteWidth;
974
975 /*
976 * Start new output datum by merging with previous input datum
977 * if necessary.
978 *
979 * Note: Before the shift, check if the shift value will be larger than
980 * the integer size. If so, there is no need to perform the operation.
981 * This avoids the differences in behavior between different compilers
982 * concerning shift values larger than the target data width.
983 */
984 if ((AccessBitWidth - ObjDesc->CommonField.StartFieldBitOffset) <
985 ACPI_INTEGER_BIT_SIZE)
986 {
987 MergedDatum = RawDatum >>
988 (AccessBitWidth - ObjDesc->CommonField.StartFieldBitOffset);
989 }
990 else
991 {
992 MergedDatum = 0;
993 }
994
995 Mask = WidthMask;
996
997 if (i == DatumCount)
998 {
999 break;
1000 }
1001
1002 /* Get the next input datum from the buffer */
1003
1004 BufferOffset += ObjDesc->CommonField.AccessByteWidth;
1005 ACPI_MEMCPY (&RawDatum, ((char *) Buffer) + BufferOffset,
1006 ACPI_MIN(ObjDesc->CommonField.AccessByteWidth,
1007 BufferLength - BufferOffset));
1008
1009 MergedDatum |= RawDatum << ObjDesc->CommonField.StartFieldBitOffset;
1010 }
1011
1012 /* Mask off any extra bits in the last datum */
1013
1014 BufferTailBits = (ObjDesc->CommonField.BitLength +
1015 ObjDesc->CommonField.StartFieldBitOffset) % AccessBitWidth;
1016 if (BufferTailBits)
1017 {
1018 Mask &= ACPI_MASK_BITS_ABOVE (BufferTailBits);
1019 }
1020
1021 /* Write the last datum to the field */
1022
1023 MergedDatum &= Mask;
1024 Status = AcpiExWriteWithUpdateRule (ObjDesc,
1025 Mask, MergedDatum, FieldOffset);
1026
1027 Exit:
1028 /* Free temporary buffer if we used one */
1029
1030 if (NewBuffer)
1031 {
1032 ACPI_FREE (NewBuffer);
1033 }
1034 return_ACPI_STATUS (Status);
1035 }
1036
1037