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 1038