1/****************************************************************************** 2 * 3 * Module Name: exfldio - Aml Field I/O 4 * 5 *****************************************************************************/ 6 7/* 8 * Copyright (C) 2000 - 2010, 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 52ACPI_MODULE_NAME("exfldio") 53 54/* Local prototypes */ 55static acpi_status 56acpi_ex_field_datum_io(union acpi_operand_object *obj_desc, 57 u32 field_datum_byte_offset, 58 u64 *value, u32 read_write); 59 60static u8 61acpi_ex_register_overflow(union acpi_operand_object *obj_desc, u64 value); 62 63static acpi_status 64acpi_ex_setup_region(union acpi_operand_object *obj_desc, 65 u32 field_datum_byte_offset); 66 67/******************************************************************************* 68 * 69 * FUNCTION: acpi_ex_setup_region 70 * 71 * PARAMETERS: obj_desc - Field to be read or written 72 * field_datum_byte_offset - Byte offset of this datum within the 73 * parent field 74 * 75 * RETURN: Status 76 * 77 * DESCRIPTION: Common processing for acpi_ex_extract_from_field and 78 * acpi_ex_insert_into_field. Initialize the Region if necessary and 79 * validate the request. 80 * 81 ******************************************************************************/ 82 83static acpi_status 84acpi_ex_setup_region(union acpi_operand_object *obj_desc, 85 u32 field_datum_byte_offset) 86{ 87 acpi_status status = AE_OK; 88 union acpi_operand_object *rgn_desc; 89 90 ACPI_FUNCTION_TRACE_U32(ex_setup_region, field_datum_byte_offset); 91 92 rgn_desc = obj_desc->common_field.region_obj; 93 94 /* We must have a valid region */ 95 96 if (rgn_desc->common.type != ACPI_TYPE_REGION) { 97 ACPI_ERROR((AE_INFO, "Needed Region, found type 0x%X (%s)", 98 rgn_desc->common.type, 99 acpi_ut_get_object_type_name(rgn_desc))); 100 101 return_ACPI_STATUS(AE_AML_OPERAND_TYPE); 102 } 103 104 /* 105 * If the Region Address and Length have not been previously evaluated, 106 * evaluate them now and save the results. 107 */ 108 if (!(rgn_desc->common.flags & AOPOBJ_DATA_VALID)) { 109 status = acpi_ds_get_region_arguments(rgn_desc); 110 if (ACPI_FAILURE(status)) { 111 return_ACPI_STATUS(status); 112 } 113 } 114 115 /* Exit if Address/Length have been disallowed by the host OS */ 116 117 if (rgn_desc->common.flags & AOPOBJ_INVALID) { 118 return_ACPI_STATUS(AE_AML_ILLEGAL_ADDRESS); 119 } 120 121 /* 122 * Exit now for SMBus or IPMI address space, it has a non-linear address space 123 * and the request cannot be directly validated 124 */ 125 if (rgn_desc->region.space_id == ACPI_ADR_SPACE_SMBUS || 126 rgn_desc->region.space_id == ACPI_ADR_SPACE_IPMI) { 127 128 /* SMBus or IPMI has a non-linear address space */ 129 130 return_ACPI_STATUS(AE_OK); 131 } 132#ifdef ACPI_UNDER_DEVELOPMENT 133 /* 134 * If the Field access is any_acc, we can now compute the optimal 135 * access (because we know know the length of the parent region) 136 */ 137 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) { 138 if (ACPI_FAILURE(status)) { 139 return_ACPI_STATUS(status); 140 } 141 } 142#endif 143 144 /* 145 * Validate the request. The entire request from the byte offset for a 146 * length of one field datum (access width) must fit within the region. 147 * (Region length is specified in bytes) 148 */ 149 if (rgn_desc->region.length < 150 (obj_desc->common_field.base_byte_offset + 151 field_datum_byte_offset + 152 obj_desc->common_field.access_byte_width)) { 153 if (acpi_gbl_enable_interpreter_slack) { 154 /* 155 * Slack mode only: We will go ahead and allow access to this 156 * field if it is within the region length rounded up to the next 157 * access width boundary. acpi_size cast for 64-bit compile. 158 */ 159 if (ACPI_ROUND_UP(rgn_desc->region.length, 160 obj_desc->common_field. 161 access_byte_width) >= 162 ((acpi_size) obj_desc->common_field. 163 base_byte_offset + 164 obj_desc->common_field.access_byte_width + 165 field_datum_byte_offset)) { 166 return_ACPI_STATUS(AE_OK); 167 } 168 } 169 170 if (rgn_desc->region.length < 171 obj_desc->common_field.access_byte_width) { 172 /* 173 * This is the case where the access_type (acc_word, etc.) is wider 174 * than the region itself. For example, a region of length one 175 * byte, and a field with Dword access specified. 176 */ 177 ACPI_ERROR((AE_INFO, 178 "Field [%4.4s] access width (%u bytes) too large for region [%4.4s] (length %u)", 179 acpi_ut_get_node_name(obj_desc-> 180 common_field.node), 181 obj_desc->common_field.access_byte_width, 182 acpi_ut_get_node_name(rgn_desc->region. 183 node), 184 rgn_desc->region.length)); 185 } 186 187 /* 188 * Offset rounded up to next multiple of field width 189 * exceeds region length, indicate an error 190 */ 191 ACPI_ERROR((AE_INFO, 192 "Field [%4.4s] Base+Offset+Width %u+%u+%u is beyond end of region [%4.4s] (length %u)", 193 acpi_ut_get_node_name(obj_desc->common_field.node), 194 obj_desc->common_field.base_byte_offset, 195 field_datum_byte_offset, 196 obj_desc->common_field.access_byte_width, 197 acpi_ut_get_node_name(rgn_desc->region.node), 198 rgn_desc->region.length)); 199 200 return_ACPI_STATUS(AE_AML_REGION_LIMIT); 201 } 202 203 return_ACPI_STATUS(AE_OK); 204} 205 206/******************************************************************************* 207 * 208 * FUNCTION: acpi_ex_access_region 209 * 210 * PARAMETERS: obj_desc - Field to be read 211 * field_datum_byte_offset - Byte offset of this datum within the 212 * parent field 213 * Value - Where to store value (must at least 214 * 64 bits) 215 * Function - Read or Write flag plus other region- 216 * dependent flags 217 * 218 * RETURN: Status 219 * 220 * DESCRIPTION: Read or Write a single field datum to an Operation Region. 221 * 222 ******************************************************************************/ 223 224acpi_status 225acpi_ex_access_region(union acpi_operand_object *obj_desc, 226 u32 field_datum_byte_offset, u64 *value, u32 function) 227{ 228 acpi_status status; 229 union acpi_operand_object *rgn_desc; 230 u32 region_offset; 231 232 ACPI_FUNCTION_TRACE(ex_access_region); 233 234 /* 235 * Ensure that the region operands are fully evaluated and verify 236 * the validity of the request 237 */ 238 status = acpi_ex_setup_region(obj_desc, field_datum_byte_offset); 239 if (ACPI_FAILURE(status)) { 240 return_ACPI_STATUS(status); 241 } 242 243 /* 244 * The physical address of this field datum is: 245 * 246 * 1) The base of the region, plus 247 * 2) The base offset of the field, plus 248 * 3) The current offset into the field 249 */ 250 rgn_desc = obj_desc->common_field.region_obj; 251 region_offset = 252 obj_desc->common_field.base_byte_offset + field_datum_byte_offset; 253 254 if ((function & ACPI_IO_MASK) == ACPI_READ) { 255 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[READ]")); 256 } else { 257 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[WRITE]")); 258 } 259 260 ACPI_DEBUG_PRINT_RAW((ACPI_DB_BFIELD, 261 " Region [%s:%X], Width %X, ByteBase %X, Offset %X at %p\n", 262 acpi_ut_get_region_name(rgn_desc->region. 263 space_id), 264 rgn_desc->region.space_id, 265 obj_desc->common_field.access_byte_width, 266 obj_desc->common_field.base_byte_offset, 267 field_datum_byte_offset, ACPI_CAST_PTR(void, 268 (rgn_desc-> 269 region. 270 address + 271 region_offset)))); 272 273 /* Invoke the appropriate address_space/op_region handler */ 274 275 status = 276 acpi_ev_address_space_dispatch(rgn_desc, function, region_offset, 277 ACPI_MUL_8(obj_desc->common_field. 278 access_byte_width), 279 value); 280 281 if (ACPI_FAILURE(status)) { 282 if (status == AE_NOT_IMPLEMENTED) { 283 ACPI_ERROR((AE_INFO, 284 "Region %s(0x%X) not implemented", 285 acpi_ut_get_region_name(rgn_desc->region. 286 space_id), 287 rgn_desc->region.space_id)); 288 } else if (status == AE_NOT_EXIST) { 289 ACPI_ERROR((AE_INFO, 290 "Region %s(0x%X) has no handler", 291 acpi_ut_get_region_name(rgn_desc->region. 292 space_id), 293 rgn_desc->region.space_id)); 294 } 295 } 296 297 return_ACPI_STATUS(status); 298} 299 300/******************************************************************************* 301 * 302 * FUNCTION: acpi_ex_register_overflow 303 * 304 * PARAMETERS: obj_desc - Register(Field) to be written 305 * Value - Value to be stored 306 * 307 * RETURN: TRUE if value overflows the field, FALSE otherwise 308 * 309 * DESCRIPTION: Check if a value is out of range of the field being written. 310 * Used to check if the values written to Index and Bank registers 311 * are out of range. Normally, the value is simply truncated 312 * to fit the field, but this case is most likely a serious 313 * coding error in the ASL. 314 * 315 ******************************************************************************/ 316 317static u8 318acpi_ex_register_overflow(union acpi_operand_object *obj_desc, u64 value) 319{ 320 321 if (obj_desc->common_field.bit_length >= ACPI_INTEGER_BIT_SIZE) { 322 /* 323 * The field is large enough to hold the maximum integer, so we can 324 * never overflow it. 325 */ 326 return (FALSE); 327 } 328 329 if (value >= ((u64) 1 << obj_desc->common_field.bit_length)) { 330 /* 331 * The Value is larger than the maximum value that can fit into 332 * the register. 333 */ 334 return (TRUE); 335 } 336 337 /* The Value will fit into the field with no truncation */ 338 339 return (FALSE); 340} 341 342/******************************************************************************* 343 * 344 * FUNCTION: acpi_ex_field_datum_io 345 * 346 * PARAMETERS: obj_desc - Field to be read 347 * field_datum_byte_offset - Byte offset of this datum within the 348 * parent field 349 * Value - Where to store value (must be 64 bits) 350 * read_write - Read or Write flag 351 * 352 * RETURN: Status 353 * 354 * DESCRIPTION: Read or Write a single datum of a field. The field_type is 355 * demultiplexed here to handle the different types of fields 356 * (buffer_field, region_field, index_field, bank_field) 357 * 358 ******************************************************************************/ 359 360static acpi_status 361acpi_ex_field_datum_io(union acpi_operand_object *obj_desc, 362 u32 field_datum_byte_offset, u64 *value, u32 read_write) 363{ 364 acpi_status status; 365 u64 local_value; 366 367 ACPI_FUNCTION_TRACE_U32(ex_field_datum_io, field_datum_byte_offset); 368 369 if (read_write == ACPI_READ) { 370 if (!value) { 371 local_value = 0; 372 373 /* To support reads without saving return value */ 374 value = &local_value; 375 } 376 377 /* Clear the entire return buffer first, [Very Important!] */ 378 379 *value = 0; 380 } 381 382 /* 383 * The four types of fields are: 384 * 385 * buffer_field - Read/write from/to a Buffer 386 * region_field - Read/write from/to a Operation Region. 387 * bank_field - Write to a Bank Register, then read/write from/to an 388 * operation_region 389 * index_field - Write to an Index Register, then read/write from/to a 390 * Data Register 391 */ 392 switch (obj_desc->common.type) { 393 case ACPI_TYPE_BUFFER_FIELD: 394 /* 395 * If the buffer_field arguments have not been previously evaluated, 396 * evaluate them now and save the results. 397 */ 398 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) { 399 status = acpi_ds_get_buffer_field_arguments(obj_desc); 400 if (ACPI_FAILURE(status)) { 401 return_ACPI_STATUS(status); 402 } 403 } 404 405 if (read_write == ACPI_READ) { 406 /* 407 * Copy the data from the source buffer. 408 * Length is the field width in bytes. 409 */ 410 ACPI_MEMCPY(value, 411 (obj_desc->buffer_field.buffer_obj)->buffer. 412 pointer + 413 obj_desc->buffer_field.base_byte_offset + 414 field_datum_byte_offset, 415 obj_desc->common_field.access_byte_width); 416 } else { 417 /* 418 * Copy the data to the target buffer. 419 * Length is the field width in bytes. 420 */ 421 ACPI_MEMCPY((obj_desc->buffer_field.buffer_obj)->buffer. 422 pointer + 423 obj_desc->buffer_field.base_byte_offset + 424 field_datum_byte_offset, value, 425 obj_desc->common_field.access_byte_width); 426 } 427 428 status = AE_OK; 429 break; 430 431 case ACPI_TYPE_LOCAL_BANK_FIELD: 432 433 /* 434 * Ensure that the bank_value is not beyond the capacity of 435 * the register 436 */ 437 if (acpi_ex_register_overflow(obj_desc->bank_field.bank_obj, 438 (u64) obj_desc->bank_field. 439 value)) { 440 return_ACPI_STATUS(AE_AML_REGISTER_LIMIT); 441 } 442 443 /* 444 * For bank_fields, we must write the bank_value to the bank_register 445 * (itself a region_field) before we can access the data. 446 */ 447 status = 448 acpi_ex_insert_into_field(obj_desc->bank_field.bank_obj, 449 &obj_desc->bank_field.value, 450 sizeof(obj_desc->bank_field. 451 value)); 452 if (ACPI_FAILURE(status)) { 453 return_ACPI_STATUS(status); 454 } 455 456 /* 457 * Now that the Bank has been selected, fall through to the 458 * region_field case and write the datum to the Operation Region 459 */ 460 461 /*lint -fallthrough */ 462 463 case ACPI_TYPE_LOCAL_REGION_FIELD: 464 /* 465 * For simple region_fields, we just directly access the owning 466 * Operation Region. 467 */ 468 status = 469 acpi_ex_access_region(obj_desc, field_datum_byte_offset, 470 value, read_write); 471 break; 472 473 case ACPI_TYPE_LOCAL_INDEX_FIELD: 474 475 /* 476 * Ensure that the index_value is not beyond the capacity of 477 * the register 478 */ 479 if (acpi_ex_register_overflow(obj_desc->index_field.index_obj, 480 (u64) obj_desc->index_field. 481 value)) { 482 return_ACPI_STATUS(AE_AML_REGISTER_LIMIT); 483 } 484 485 /* Write the index value to the index_register (itself a region_field) */ 486 487 field_datum_byte_offset += obj_desc->index_field.value; 488 489 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, 490 "Write to Index Register: Value %8.8X\n", 491 field_datum_byte_offset)); 492 493 status = 494 acpi_ex_insert_into_field(obj_desc->index_field.index_obj, 495 &field_datum_byte_offset, 496 sizeof(field_datum_byte_offset)); 497 if (ACPI_FAILURE(status)) { 498 return_ACPI_STATUS(status); 499 } 500 501 if (read_write == ACPI_READ) { 502 503 /* Read the datum from the data_register */ 504 505 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, 506 "Read from Data Register\n")); 507 508 status = 509 acpi_ex_extract_from_field(obj_desc->index_field. 510 data_obj, value, 511 sizeof(u64)); 512 } else { 513 /* Write the datum to the data_register */ 514 515 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, 516 "Write to Data Register: Value %8.8X%8.8X\n", 517 ACPI_FORMAT_UINT64(*value))); 518 519 status = 520 acpi_ex_insert_into_field(obj_desc->index_field. 521 data_obj, value, 522 sizeof(u64)); 523 } 524 break; 525 526 default: 527 528 ACPI_ERROR((AE_INFO, "Wrong object type in field I/O %u", 529 obj_desc->common.type)); 530 status = AE_AML_INTERNAL; 531 break; 532 } 533 534 if (ACPI_SUCCESS(status)) { 535 if (read_write == ACPI_READ) { 536 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, 537 "Value Read %8.8X%8.8X, Width %u\n", 538 ACPI_FORMAT_UINT64(*value), 539 obj_desc->common_field. 540 access_byte_width)); 541 } else { 542 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, 543 "Value Written %8.8X%8.8X, Width %u\n", 544 ACPI_FORMAT_UINT64(*value), 545 obj_desc->common_field. 546 access_byte_width)); 547 } 548 } 549 550 return_ACPI_STATUS(status); 551} 552 553/******************************************************************************* 554 * 555 * FUNCTION: acpi_ex_write_with_update_rule 556 * 557 * PARAMETERS: obj_desc - Field to be written 558 * Mask - bitmask within field datum 559 * field_value - Value to write 560 * field_datum_byte_offset - Offset of datum within field 561 * 562 * RETURN: Status 563 * 564 * DESCRIPTION: Apply the field update rule to a field write 565 * 566 ******************************************************************************/ 567 568acpi_status 569acpi_ex_write_with_update_rule(union acpi_operand_object *obj_desc, 570 u64 mask, 571 u64 field_value, u32 field_datum_byte_offset) 572{ 573 acpi_status status = AE_OK; 574 u64 merged_value; 575 u64 current_value; 576 577 ACPI_FUNCTION_TRACE_U32(ex_write_with_update_rule, mask); 578 579 /* Start with the new bits */ 580 581 merged_value = field_value; 582 583 /* If the mask is all ones, we don't need to worry about the update rule */ 584 585 if (mask != ACPI_UINT64_MAX) { 586 587 /* Decode the update rule */ 588 589 switch (obj_desc->common_field. 590 field_flags & AML_FIELD_UPDATE_RULE_MASK) { 591 case AML_FIELD_UPDATE_PRESERVE: 592 /* 593 * Check if update rule needs to be applied (not if mask is all 594 * ones) The left shift drops the bits we want to ignore. 595 */ 596 if ((~mask << (ACPI_MUL_8(sizeof(mask)) - 597 ACPI_MUL_8(obj_desc->common_field. 598 access_byte_width))) != 0) { 599 /* 600 * Read the current contents of the byte/word/dword containing 601 * the field, and merge with the new field value. 602 */ 603 status = 604 acpi_ex_field_datum_io(obj_desc, 605 field_datum_byte_offset, 606 ¤t_value, 607 ACPI_READ); 608 if (ACPI_FAILURE(status)) { 609 return_ACPI_STATUS(status); 610 } 611 612 merged_value |= (current_value & ~mask); 613 } 614 break; 615 616 case AML_FIELD_UPDATE_WRITE_AS_ONES: 617 618 /* Set positions outside the field to all ones */ 619 620 merged_value |= ~mask; 621 break; 622 623 case AML_FIELD_UPDATE_WRITE_AS_ZEROS: 624 625 /* Set positions outside the field to all zeros */ 626 627 merged_value &= mask; 628 break; 629 630 default: 631 632 ACPI_ERROR((AE_INFO, 633 "Unknown UpdateRule value: 0x%X", 634 (obj_desc->common_field. 635 field_flags & 636 AML_FIELD_UPDATE_RULE_MASK))); 637 return_ACPI_STATUS(AE_AML_OPERAND_VALUE); 638 } 639 } 640 641 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, 642 "Mask %8.8X%8.8X, DatumOffset %X, Width %X, Value %8.8X%8.8X, MergedValue %8.8X%8.8X\n", 643 ACPI_FORMAT_UINT64(mask), 644 field_datum_byte_offset, 645 obj_desc->common_field.access_byte_width, 646 ACPI_FORMAT_UINT64(field_value), 647 ACPI_FORMAT_UINT64(merged_value))); 648 649 /* Write the merged value */ 650 651 status = acpi_ex_field_datum_io(obj_desc, field_datum_byte_offset, 652 &merged_value, ACPI_WRITE); 653 654 return_ACPI_STATUS(status); 655} 656 657/******************************************************************************* 658 * 659 * FUNCTION: acpi_ex_extract_from_field 660 * 661 * PARAMETERS: obj_desc - Field to be read 662 * Buffer - Where to store the field data 663 * buffer_length - Length of Buffer 664 * 665 * RETURN: Status 666 * 667 * DESCRIPTION: Retrieve the current value of the given field 668 * 669 ******************************************************************************/ 670 671acpi_status 672acpi_ex_extract_from_field(union acpi_operand_object *obj_desc, 673 void *buffer, u32 buffer_length) 674{ 675 acpi_status status; 676 u64 raw_datum; 677 u64 merged_datum; 678 u32 field_offset = 0; 679 u32 buffer_offset = 0; 680 u32 buffer_tail_bits; 681 u32 datum_count; 682 u32 field_datum_count; 683 u32 i; 684 685 ACPI_FUNCTION_TRACE(ex_extract_from_field); 686 687 /* Validate target buffer and clear it */ 688 689 if (buffer_length < 690 ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length)) { 691 ACPI_ERROR((AE_INFO, 692 "Field size %u (bits) is too large for buffer (%u)", 693 obj_desc->common_field.bit_length, buffer_length)); 694 695 return_ACPI_STATUS(AE_BUFFER_OVERFLOW); 696 } 697 ACPI_MEMSET(buffer, 0, buffer_length); 698 699 /* Compute the number of datums (access width data items) */ 700 701 datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length, 702 obj_desc->common_field.access_bit_width); 703 field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length + 704 obj_desc->common_field. 705 start_field_bit_offset, 706 obj_desc->common_field. 707 access_bit_width); 708 709 /* Priming read from the field */ 710 711 status = 712 acpi_ex_field_datum_io(obj_desc, field_offset, &raw_datum, 713 ACPI_READ); 714 if (ACPI_FAILURE(status)) { 715 return_ACPI_STATUS(status); 716 } 717 merged_datum = 718 raw_datum >> obj_desc->common_field.start_field_bit_offset; 719 720 /* Read the rest of the field */ 721 722 for (i = 1; i < field_datum_count; i++) { 723 724 /* Get next input datum from the field */ 725 726 field_offset += obj_desc->common_field.access_byte_width; 727 status = acpi_ex_field_datum_io(obj_desc, field_offset, 728 &raw_datum, ACPI_READ); 729 if (ACPI_FAILURE(status)) { 730 return_ACPI_STATUS(status); 731 } 732 733 /* 734 * Merge with previous datum if necessary. 735 * 736 * Note: Before the shift, check if the shift value will be larger than 737 * the integer size. If so, there is no need to perform the operation. 738 * This avoids the differences in behavior between different compilers 739 * concerning shift values larger than the target data width. 740 */ 741 if ((obj_desc->common_field.access_bit_width - 742 obj_desc->common_field.start_field_bit_offset) < 743 ACPI_INTEGER_BIT_SIZE) { 744 merged_datum |= 745 raw_datum << (obj_desc->common_field. 746 access_bit_width - 747 obj_desc->common_field. 748 start_field_bit_offset); 749 } 750 751 if (i == datum_count) { 752 break; 753 } 754 755 /* Write merged datum to target buffer */ 756 757 ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum, 758 ACPI_MIN(obj_desc->common_field.access_byte_width, 759 buffer_length - buffer_offset)); 760 761 buffer_offset += obj_desc->common_field.access_byte_width; 762 merged_datum = 763 raw_datum >> obj_desc->common_field.start_field_bit_offset; 764 } 765 766 /* Mask off any extra bits in the last datum */ 767 768 buffer_tail_bits = obj_desc->common_field.bit_length % 769 obj_desc->common_field.access_bit_width; 770 if (buffer_tail_bits) { 771 merged_datum &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits); 772 } 773 774 /* Write the last datum to the buffer */ 775 776 ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum, 777 ACPI_MIN(obj_desc->common_field.access_byte_width, 778 buffer_length - buffer_offset)); 779 780 return_ACPI_STATUS(AE_OK); 781} 782 783/******************************************************************************* 784 * 785 * FUNCTION: acpi_ex_insert_into_field 786 * 787 * PARAMETERS: obj_desc - Field to be written 788 * Buffer - Data to be written 789 * buffer_length - Length of Buffer 790 * 791 * RETURN: Status 792 * 793 * DESCRIPTION: Store the Buffer contents into the given field 794 * 795 ******************************************************************************/ 796 797acpi_status 798acpi_ex_insert_into_field(union acpi_operand_object *obj_desc, 799 void *buffer, u32 buffer_length) 800{ 801 acpi_status status; 802 u64 mask; 803 u64 width_mask; 804 u64 merged_datum; 805 u64 raw_datum = 0; 806 u32 field_offset = 0; 807 u32 buffer_offset = 0; 808 u32 buffer_tail_bits; 809 u32 datum_count; 810 u32 field_datum_count; 811 u32 i; 812 u32 required_length; 813 void *new_buffer; 814 815 ACPI_FUNCTION_TRACE(ex_insert_into_field); 816 817 /* Validate input buffer */ 818 819 new_buffer = NULL; 820 required_length = 821 ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length); 822 /* 823 * We must have a buffer that is at least as long as the field 824 * we are writing to. This is because individual fields are 825 * indivisible and partial writes are not supported -- as per 826 * the ACPI specification. 827 */ 828 if (buffer_length < required_length) { 829 830 /* We need to create a new buffer */ 831 832 new_buffer = ACPI_ALLOCATE_ZEROED(required_length); 833 if (!new_buffer) { 834 return_ACPI_STATUS(AE_NO_MEMORY); 835 } 836 837 /* 838 * Copy the original data to the new buffer, starting 839 * at Byte zero. All unused (upper) bytes of the 840 * buffer will be 0. 841 */ 842 ACPI_MEMCPY((char *)new_buffer, (char *)buffer, buffer_length); 843 buffer = new_buffer; 844 buffer_length = required_length; 845 } 846 847 /* 848 * Create the bitmasks used for bit insertion. 849 * Note: This if/else is used to bypass compiler differences with the 850 * shift operator 851 */ 852 if (obj_desc->common_field.access_bit_width == ACPI_INTEGER_BIT_SIZE) { 853 width_mask = ACPI_UINT64_MAX; 854 } else { 855 width_mask = 856 ACPI_MASK_BITS_ABOVE(obj_desc->common_field. 857 access_bit_width); 858 } 859 860 mask = width_mask & 861 ACPI_MASK_BITS_BELOW(obj_desc->common_field.start_field_bit_offset); 862 863 /* Compute the number of datums (access width data items) */ 864 865 datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length, 866 obj_desc->common_field.access_bit_width); 867 868 field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length + 869 obj_desc->common_field. 870 start_field_bit_offset, 871 obj_desc->common_field. 872 access_bit_width); 873 874 /* Get initial Datum from the input buffer */ 875 876 ACPI_MEMCPY(&raw_datum, buffer, 877 ACPI_MIN(obj_desc->common_field.access_byte_width, 878 buffer_length - buffer_offset)); 879 880 merged_datum = 881 raw_datum << obj_desc->common_field.start_field_bit_offset; 882 883 /* Write the entire field */ 884 885 for (i = 1; i < field_datum_count; i++) { 886 887 /* Write merged datum to the target field */ 888 889 merged_datum &= mask; 890 status = acpi_ex_write_with_update_rule(obj_desc, mask, 891 merged_datum, 892 field_offset); 893 if (ACPI_FAILURE(status)) { 894 goto exit; 895 } 896 897 field_offset += obj_desc->common_field.access_byte_width; 898 899 /* 900 * Start new output datum by merging with previous input datum 901 * if necessary. 902 * 903 * Note: Before the shift, check if the shift value will be larger than 904 * the integer size. If so, there is no need to perform the operation. 905 * This avoids the differences in behavior between different compilers 906 * concerning shift values larger than the target data width. 907 */ 908 if ((obj_desc->common_field.access_bit_width - 909 obj_desc->common_field.start_field_bit_offset) < 910 ACPI_INTEGER_BIT_SIZE) { 911 merged_datum = 912 raw_datum >> (obj_desc->common_field. 913 access_bit_width - 914 obj_desc->common_field. 915 start_field_bit_offset); 916 } else { 917 merged_datum = 0; 918 } 919 920 mask = width_mask; 921 922 if (i == datum_count) { 923 break; 924 } 925 926 /* Get the next input datum from the buffer */ 927 928 buffer_offset += obj_desc->common_field.access_byte_width; 929 ACPI_MEMCPY(&raw_datum, ((char *)buffer) + buffer_offset, 930 ACPI_MIN(obj_desc->common_field.access_byte_width, 931 buffer_length - buffer_offset)); 932 merged_datum |= 933 raw_datum << obj_desc->common_field.start_field_bit_offset; 934 } 935 936 /* Mask off any extra bits in the last datum */ 937 938 buffer_tail_bits = (obj_desc->common_field.bit_length + 939 obj_desc->common_field.start_field_bit_offset) % 940 obj_desc->common_field.access_bit_width; 941 if (buffer_tail_bits) { 942 mask &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits); 943 } 944 945 /* Write the last datum to the field */ 946 947 merged_datum &= mask; 948 status = acpi_ex_write_with_update_rule(obj_desc, 949 mask, merged_datum, 950 field_offset); 951 952 exit: 953 /* Free temporary buffer if we used one */ 954 955 if (new_buffer) { 956 ACPI_FREE(new_buffer); 957 } 958 return_ACPI_STATUS(status); 959} 960