1 /****************************************************************************** 2 * 3 * Module Name: exfldio - Aml Field I/O 4 * 5 *****************************************************************************/ 6 7 /* 8 * Copyright (C) 2000 - 2012, 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 /* Exit if Address/Length have been disallowed by the host OS */ 127 128 if (rgn_desc->common.flags & AOPOBJ_INVALID) { 129 return_ACPI_STATUS(AE_AML_ILLEGAL_ADDRESS); 130 } 131 132 /* 133 * Exit now for SMBus, GSBus or IPMI address space, it has a non-linear 134 * address space and the request cannot be directly validated 135 */ 136 if (space_id == ACPI_ADR_SPACE_SMBUS || 137 space_id == ACPI_ADR_SPACE_GSBUS || 138 space_id == ACPI_ADR_SPACE_IPMI) { 139 140 /* SMBus or IPMI has a non-linear address space */ 141 142 return_ACPI_STATUS(AE_OK); 143 } 144 #ifdef ACPI_UNDER_DEVELOPMENT 145 /* 146 * If the Field access is any_acc, we can now compute the optimal 147 * access (because we know know the length of the parent region) 148 */ 149 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) { 150 if (ACPI_FAILURE(status)) { 151 return_ACPI_STATUS(status); 152 } 153 } 154 #endif 155 156 /* 157 * Validate the request. The entire request from the byte offset for a 158 * length of one field datum (access width) must fit within the region. 159 * (Region length is specified in bytes) 160 */ 161 if (rgn_desc->region.length < 162 (obj_desc->common_field.base_byte_offset + field_datum_byte_offset + 163 obj_desc->common_field.access_byte_width)) { 164 if (acpi_gbl_enable_interpreter_slack) { 165 /* 166 * Slack mode only: We will go ahead and allow access to this 167 * field if it is within the region length rounded up to the next 168 * access width boundary. acpi_size cast for 64-bit compile. 169 */ 170 if (ACPI_ROUND_UP(rgn_desc->region.length, 171 obj_desc->common_field. 172 access_byte_width) >= 173 ((acpi_size) obj_desc->common_field. 174 base_byte_offset + 175 obj_desc->common_field.access_byte_width + 176 field_datum_byte_offset)) { 177 return_ACPI_STATUS(AE_OK); 178 } 179 } 180 181 if (rgn_desc->region.length < 182 obj_desc->common_field.access_byte_width) { 183 /* 184 * This is the case where the access_type (acc_word, etc.) is wider 185 * than the region itself. For example, a region of length one 186 * byte, and a field with Dword access specified. 187 */ 188 ACPI_ERROR((AE_INFO, 189 "Field [%4.4s] access width (%u bytes) too large for region [%4.4s] (length %u)", 190 acpi_ut_get_node_name(obj_desc-> 191 common_field.node), 192 obj_desc->common_field.access_byte_width, 193 acpi_ut_get_node_name(rgn_desc->region. 194 node), 195 rgn_desc->region.length)); 196 } 197 198 /* 199 * Offset rounded up to next multiple of field width 200 * exceeds region length, indicate an error 201 */ 202 ACPI_ERROR((AE_INFO, 203 "Field [%4.4s] Base+Offset+Width %u+%u+%u is beyond end of region [%4.4s] (length %u)", 204 acpi_ut_get_node_name(obj_desc->common_field.node), 205 obj_desc->common_field.base_byte_offset, 206 field_datum_byte_offset, 207 obj_desc->common_field.access_byte_width, 208 acpi_ut_get_node_name(rgn_desc->region.node), 209 rgn_desc->region.length)); 210 211 return_ACPI_STATUS(AE_AML_REGION_LIMIT); 212 } 213 214 return_ACPI_STATUS(AE_OK); 215 } 216 217 /******************************************************************************* 218 * 219 * FUNCTION: acpi_ex_access_region 220 * 221 * PARAMETERS: obj_desc - Field to be read 222 * field_datum_byte_offset - Byte offset of this datum within the 223 * parent field 224 * value - Where to store value (must at least 225 * 64 bits) 226 * function - Read or Write flag plus other region- 227 * dependent flags 228 * 229 * RETURN: Status 230 * 231 * DESCRIPTION: Read or Write a single field datum to an Operation Region. 232 * 233 ******************************************************************************/ 234 235 acpi_status 236 acpi_ex_access_region(union acpi_operand_object *obj_desc, 237 u32 field_datum_byte_offset, u64 *value, u32 function) 238 { 239 acpi_status status; 240 union acpi_operand_object *rgn_desc; 241 u32 region_offset; 242 243 ACPI_FUNCTION_TRACE(ex_access_region); 244 245 /* 246 * Ensure that the region operands are fully evaluated and verify 247 * the validity of the request 248 */ 249 status = acpi_ex_setup_region(obj_desc, field_datum_byte_offset); 250 if (ACPI_FAILURE(status)) { 251 return_ACPI_STATUS(status); 252 } 253 254 /* 255 * The physical address of this field datum is: 256 * 257 * 1) The base of the region, plus 258 * 2) The base offset of the field, plus 259 * 3) The current offset into the field 260 */ 261 rgn_desc = obj_desc->common_field.region_obj; 262 region_offset = 263 obj_desc->common_field.base_byte_offset + field_datum_byte_offset; 264 265 if ((function & ACPI_IO_MASK) == ACPI_READ) { 266 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[READ]")); 267 } else { 268 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[WRITE]")); 269 } 270 271 ACPI_DEBUG_PRINT_RAW((ACPI_DB_BFIELD, 272 " Region [%s:%X], Width %X, ByteBase %X, Offset %X at %p\n", 273 acpi_ut_get_region_name(rgn_desc->region. 274 space_id), 275 rgn_desc->region.space_id, 276 obj_desc->common_field.access_byte_width, 277 obj_desc->common_field.base_byte_offset, 278 field_datum_byte_offset, ACPI_CAST_PTR(void, 279 (rgn_desc-> 280 region. 281 address + 282 region_offset)))); 283 284 /* Invoke the appropriate address_space/op_region handler */ 285 286 status = acpi_ev_address_space_dispatch(rgn_desc, obj_desc, 287 function, region_offset, 288 ACPI_MUL_8(obj_desc-> 289 common_field. 290 access_byte_width), 291 value); 292 293 if (ACPI_FAILURE(status)) { 294 if (status == AE_NOT_IMPLEMENTED) { 295 ACPI_ERROR((AE_INFO, 296 "Region %s (ID=%u) not implemented", 297 acpi_ut_get_region_name(rgn_desc->region. 298 space_id), 299 rgn_desc->region.space_id)); 300 } else if (status == AE_NOT_EXIST) { 301 ACPI_ERROR((AE_INFO, 302 "Region %s (ID=%u) has no handler", 303 acpi_ut_get_region_name(rgn_desc->region. 304 space_id), 305 rgn_desc->region.space_id)); 306 } 307 } 308 309 return_ACPI_STATUS(status); 310 } 311 312 /******************************************************************************* 313 * 314 * FUNCTION: acpi_ex_register_overflow 315 * 316 * PARAMETERS: obj_desc - Register(Field) to be written 317 * value - Value to be stored 318 * 319 * RETURN: TRUE if value overflows the field, FALSE otherwise 320 * 321 * DESCRIPTION: Check if a value is out of range of the field being written. 322 * Used to check if the values written to Index and Bank registers 323 * are out of range. Normally, the value is simply truncated 324 * to fit the field, but this case is most likely a serious 325 * coding error in the ASL. 326 * 327 ******************************************************************************/ 328 329 static u8 330 acpi_ex_register_overflow(union acpi_operand_object *obj_desc, u64 value) 331 { 332 ACPI_FUNCTION_NAME(ex_register_overflow); 333 334 if (obj_desc->common_field.bit_length >= ACPI_INTEGER_BIT_SIZE) { 335 /* 336 * The field is large enough to hold the maximum integer, so we can 337 * never overflow it. 338 */ 339 return (FALSE); 340 } 341 342 if (value >= ((u64) 1 << obj_desc->common_field.bit_length)) { 343 /* 344 * The Value is larger than the maximum value that can fit into 345 * the register. 346 */ 347 ACPI_ERROR((AE_INFO, 348 "Index value 0x%8.8X%8.8X overflows field width 0x%X", 349 ACPI_FORMAT_UINT64(value), 350 obj_desc->common_field.bit_length)); 351 352 return (TRUE); 353 } 354 355 /* The Value will fit into the field with no truncation */ 356 357 return (FALSE); 358 } 359 360 /******************************************************************************* 361 * 362 * FUNCTION: acpi_ex_field_datum_io 363 * 364 * PARAMETERS: obj_desc - Field to be read 365 * field_datum_byte_offset - Byte offset of this datum within the 366 * parent field 367 * value - Where to store value (must be 64 bits) 368 * read_write - Read or Write flag 369 * 370 * RETURN: Status 371 * 372 * DESCRIPTION: Read or Write a single datum of a field. The field_type is 373 * demultiplexed here to handle the different types of fields 374 * (buffer_field, region_field, index_field, bank_field) 375 * 376 ******************************************************************************/ 377 378 static acpi_status 379 acpi_ex_field_datum_io(union acpi_operand_object *obj_desc, 380 u32 field_datum_byte_offset, u64 *value, u32 read_write) 381 { 382 acpi_status status; 383 u64 local_value; 384 385 ACPI_FUNCTION_TRACE_U32(ex_field_datum_io, field_datum_byte_offset); 386 387 if (read_write == ACPI_READ) { 388 if (!value) { 389 local_value = 0; 390 391 /* To support reads without saving return value */ 392 value = &local_value; 393 } 394 395 /* Clear the entire return buffer first, [Very Important!] */ 396 397 *value = 0; 398 } 399 400 /* 401 * The four types of fields are: 402 * 403 * buffer_field - Read/write from/to a Buffer 404 * region_field - Read/write from/to a Operation Region. 405 * bank_field - Write to a Bank Register, then read/write from/to an 406 * operation_region 407 * index_field - Write to an Index Register, then read/write from/to a 408 * Data Register 409 */ 410 switch (obj_desc->common.type) { 411 case ACPI_TYPE_BUFFER_FIELD: 412 /* 413 * If the buffer_field arguments have not been previously evaluated, 414 * evaluate them now and save the results. 415 */ 416 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) { 417 status = acpi_ds_get_buffer_field_arguments(obj_desc); 418 if (ACPI_FAILURE(status)) { 419 return_ACPI_STATUS(status); 420 } 421 } 422 423 if (read_write == ACPI_READ) { 424 /* 425 * Copy the data from the source buffer. 426 * Length is the field width in bytes. 427 */ 428 ACPI_MEMCPY(value, 429 (obj_desc->buffer_field.buffer_obj)->buffer. 430 pointer + 431 obj_desc->buffer_field.base_byte_offset + 432 field_datum_byte_offset, 433 obj_desc->common_field.access_byte_width); 434 } else { 435 /* 436 * Copy the data to the target buffer. 437 * Length is the field width in bytes. 438 */ 439 ACPI_MEMCPY((obj_desc->buffer_field.buffer_obj)->buffer. 440 pointer + 441 obj_desc->buffer_field.base_byte_offset + 442 field_datum_byte_offset, value, 443 obj_desc->common_field.access_byte_width); 444 } 445 446 status = AE_OK; 447 break; 448 449 case ACPI_TYPE_LOCAL_BANK_FIELD: 450 451 /* 452 * Ensure that the bank_value is not beyond the capacity of 453 * the register 454 */ 455 if (acpi_ex_register_overflow(obj_desc->bank_field.bank_obj, 456 (u64) obj_desc->bank_field. 457 value)) { 458 return_ACPI_STATUS(AE_AML_REGISTER_LIMIT); 459 } 460 461 /* 462 * For bank_fields, we must write the bank_value to the bank_register 463 * (itself a region_field) before we can access the data. 464 */ 465 status = 466 acpi_ex_insert_into_field(obj_desc->bank_field.bank_obj, 467 &obj_desc->bank_field.value, 468 sizeof(obj_desc->bank_field. 469 value)); 470 if (ACPI_FAILURE(status)) { 471 return_ACPI_STATUS(status); 472 } 473 474 /* 475 * Now that the Bank has been selected, fall through to the 476 * region_field case and write the datum to the Operation Region 477 */ 478 479 /*lint -fallthrough */ 480 481 case ACPI_TYPE_LOCAL_REGION_FIELD: 482 /* 483 * For simple region_fields, we just directly access the owning 484 * Operation Region. 485 */ 486 status = 487 acpi_ex_access_region(obj_desc, field_datum_byte_offset, 488 value, read_write); 489 break; 490 491 case ACPI_TYPE_LOCAL_INDEX_FIELD: 492 493 /* 494 * Ensure that the index_value is not beyond the capacity of 495 * the register 496 */ 497 if (acpi_ex_register_overflow(obj_desc->index_field.index_obj, 498 (u64) obj_desc->index_field. 499 value)) { 500 return_ACPI_STATUS(AE_AML_REGISTER_LIMIT); 501 } 502 503 /* Write the index value to the index_register (itself a region_field) */ 504 505 field_datum_byte_offset += obj_desc->index_field.value; 506 507 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, 508 "Write to Index Register: Value %8.8X\n", 509 field_datum_byte_offset)); 510 511 status = 512 acpi_ex_insert_into_field(obj_desc->index_field.index_obj, 513 &field_datum_byte_offset, 514 sizeof(field_datum_byte_offset)); 515 if (ACPI_FAILURE(status)) { 516 return_ACPI_STATUS(status); 517 } 518 519 if (read_write == ACPI_READ) { 520 521 /* Read the datum from the data_register */ 522 523 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, 524 "Read from Data Register\n")); 525 526 status = 527 acpi_ex_extract_from_field(obj_desc->index_field. 528 data_obj, value, 529 sizeof(u64)); 530 } else { 531 /* Write the datum to the data_register */ 532 533 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, 534 "Write to Data Register: Value %8.8X%8.8X\n", 535 ACPI_FORMAT_UINT64(*value))); 536 537 status = 538 acpi_ex_insert_into_field(obj_desc->index_field. 539 data_obj, value, 540 sizeof(u64)); 541 } 542 break; 543 544 default: 545 546 ACPI_ERROR((AE_INFO, "Wrong object type in field I/O %u", 547 obj_desc->common.type)); 548 status = AE_AML_INTERNAL; 549 break; 550 } 551 552 if (ACPI_SUCCESS(status)) { 553 if (read_write == ACPI_READ) { 554 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, 555 "Value Read %8.8X%8.8X, Width %u\n", 556 ACPI_FORMAT_UINT64(*value), 557 obj_desc->common_field. 558 access_byte_width)); 559 } else { 560 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, 561 "Value Written %8.8X%8.8X, Width %u\n", 562 ACPI_FORMAT_UINT64(*value), 563 obj_desc->common_field. 564 access_byte_width)); 565 } 566 } 567 568 return_ACPI_STATUS(status); 569 } 570 571 /******************************************************************************* 572 * 573 * FUNCTION: acpi_ex_write_with_update_rule 574 * 575 * PARAMETERS: obj_desc - Field to be written 576 * mask - bitmask within field datum 577 * field_value - Value to write 578 * field_datum_byte_offset - Offset of datum within field 579 * 580 * RETURN: Status 581 * 582 * DESCRIPTION: Apply the field update rule to a field write 583 * 584 ******************************************************************************/ 585 586 acpi_status 587 acpi_ex_write_with_update_rule(union acpi_operand_object *obj_desc, 588 u64 mask, 589 u64 field_value, u32 field_datum_byte_offset) 590 { 591 acpi_status status = AE_OK; 592 u64 merged_value; 593 u64 current_value; 594 595 ACPI_FUNCTION_TRACE_U32(ex_write_with_update_rule, mask); 596 597 /* Start with the new bits */ 598 599 merged_value = field_value; 600 601 /* If the mask is all ones, we don't need to worry about the update rule */ 602 603 if (mask != ACPI_UINT64_MAX) { 604 605 /* Decode the update rule */ 606 607 switch (obj_desc->common_field. 608 field_flags & AML_FIELD_UPDATE_RULE_MASK) { 609 case AML_FIELD_UPDATE_PRESERVE: 610 /* 611 * Check if update rule needs to be applied (not if mask is all 612 * ones) The left shift drops the bits we want to ignore. 613 */ 614 if ((~mask << (ACPI_MUL_8(sizeof(mask)) - 615 ACPI_MUL_8(obj_desc->common_field. 616 access_byte_width))) != 0) { 617 /* 618 * Read the current contents of the byte/word/dword containing 619 * the field, and merge with the new field value. 620 */ 621 status = 622 acpi_ex_field_datum_io(obj_desc, 623 field_datum_byte_offset, 624 ¤t_value, 625 ACPI_READ); 626 if (ACPI_FAILURE(status)) { 627 return_ACPI_STATUS(status); 628 } 629 630 merged_value |= (current_value & ~mask); 631 } 632 break; 633 634 case AML_FIELD_UPDATE_WRITE_AS_ONES: 635 636 /* Set positions outside the field to all ones */ 637 638 merged_value |= ~mask; 639 break; 640 641 case AML_FIELD_UPDATE_WRITE_AS_ZEROS: 642 643 /* Set positions outside the field to all zeros */ 644 645 merged_value &= mask; 646 break; 647 648 default: 649 650 ACPI_ERROR((AE_INFO, 651 "Unknown UpdateRule value: 0x%X", 652 (obj_desc->common_field. 653 field_flags & 654 AML_FIELD_UPDATE_RULE_MASK))); 655 return_ACPI_STATUS(AE_AML_OPERAND_VALUE); 656 } 657 } 658 659 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, 660 "Mask %8.8X%8.8X, DatumOffset %X, Width %X, Value %8.8X%8.8X, MergedValue %8.8X%8.8X\n", 661 ACPI_FORMAT_UINT64(mask), 662 field_datum_byte_offset, 663 obj_desc->common_field.access_byte_width, 664 ACPI_FORMAT_UINT64(field_value), 665 ACPI_FORMAT_UINT64(merged_value))); 666 667 /* Write the merged value */ 668 669 status = acpi_ex_field_datum_io(obj_desc, field_datum_byte_offset, 670 &merged_value, ACPI_WRITE); 671 672 return_ACPI_STATUS(status); 673 } 674 675 /******************************************************************************* 676 * 677 * FUNCTION: acpi_ex_extract_from_field 678 * 679 * PARAMETERS: obj_desc - Field to be read 680 * buffer - Where to store the field data 681 * buffer_length - Length of Buffer 682 * 683 * RETURN: Status 684 * 685 * DESCRIPTION: Retrieve the current value of the given field 686 * 687 ******************************************************************************/ 688 689 acpi_status 690 acpi_ex_extract_from_field(union acpi_operand_object *obj_desc, 691 void *buffer, u32 buffer_length) 692 { 693 acpi_status status; 694 u64 raw_datum; 695 u64 merged_datum; 696 u32 field_offset = 0; 697 u32 buffer_offset = 0; 698 u32 buffer_tail_bits; 699 u32 datum_count; 700 u32 field_datum_count; 701 u32 access_bit_width; 702 u32 i; 703 704 ACPI_FUNCTION_TRACE(ex_extract_from_field); 705 706 /* Validate target buffer and clear it */ 707 708 if (buffer_length < 709 ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length)) { 710 ACPI_ERROR((AE_INFO, 711 "Field size %u (bits) is too large for buffer (%u)", 712 obj_desc->common_field.bit_length, buffer_length)); 713 714 return_ACPI_STATUS(AE_BUFFER_OVERFLOW); 715 } 716 717 ACPI_MEMSET(buffer, 0, buffer_length); 718 access_bit_width = ACPI_MUL_8(obj_desc->common_field.access_byte_width); 719 720 /* Handle the simple case here */ 721 722 if ((obj_desc->common_field.start_field_bit_offset == 0) && 723 (obj_desc->common_field.bit_length == access_bit_width)) { 724 status = acpi_ex_field_datum_io(obj_desc, 0, buffer, ACPI_READ); 725 return_ACPI_STATUS(status); 726 } 727 728 /* TBD: Move to common setup code */ 729 730 /* Field algorithm is limited to sizeof(u64), truncate if needed */ 731 732 if (obj_desc->common_field.access_byte_width > sizeof(u64)) { 733 obj_desc->common_field.access_byte_width = sizeof(u64); 734 access_bit_width = sizeof(u64) * 8; 735 } 736 737 /* Compute the number of datums (access width data items) */ 738 739 datum_count = 740 ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length, 741 access_bit_width); 742 743 field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length + 744 obj_desc->common_field. 745 start_field_bit_offset, 746 access_bit_width); 747 748 /* Priming read from the field */ 749 750 status = 751 acpi_ex_field_datum_io(obj_desc, field_offset, &raw_datum, 752 ACPI_READ); 753 if (ACPI_FAILURE(status)) { 754 return_ACPI_STATUS(status); 755 } 756 merged_datum = 757 raw_datum >> obj_desc->common_field.start_field_bit_offset; 758 759 /* Read the rest of the field */ 760 761 for (i = 1; i < field_datum_count; i++) { 762 763 /* Get next input datum from the field */ 764 765 field_offset += obj_desc->common_field.access_byte_width; 766 status = acpi_ex_field_datum_io(obj_desc, field_offset, 767 &raw_datum, ACPI_READ); 768 if (ACPI_FAILURE(status)) { 769 return_ACPI_STATUS(status); 770 } 771 772 /* 773 * Merge with previous datum if necessary. 774 * 775 * Note: Before the shift, check if the shift value will be larger than 776 * the integer size. If so, there is no need to perform the operation. 777 * This avoids the differences in behavior between different compilers 778 * concerning shift values larger than the target data width. 779 */ 780 if (access_bit_width - 781 obj_desc->common_field.start_field_bit_offset < 782 ACPI_INTEGER_BIT_SIZE) { 783 merged_datum |= 784 raw_datum << (access_bit_width - 785 obj_desc->common_field. 786 start_field_bit_offset); 787 } 788 789 if (i == datum_count) { 790 break; 791 } 792 793 /* Write merged datum to target buffer */ 794 795 ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum, 796 ACPI_MIN(obj_desc->common_field.access_byte_width, 797 buffer_length - buffer_offset)); 798 799 buffer_offset += obj_desc->common_field.access_byte_width; 800 merged_datum = 801 raw_datum >> obj_desc->common_field.start_field_bit_offset; 802 } 803 804 /* Mask off any extra bits in the last datum */ 805 806 buffer_tail_bits = obj_desc->common_field.bit_length % access_bit_width; 807 if (buffer_tail_bits) { 808 merged_datum &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits); 809 } 810 811 /* Write the last datum to the buffer */ 812 813 ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum, 814 ACPI_MIN(obj_desc->common_field.access_byte_width, 815 buffer_length - buffer_offset)); 816 817 return_ACPI_STATUS(AE_OK); 818 } 819 820 /******************************************************************************* 821 * 822 * FUNCTION: acpi_ex_insert_into_field 823 * 824 * PARAMETERS: obj_desc - Field to be written 825 * buffer - Data to be written 826 * buffer_length - Length of Buffer 827 * 828 * RETURN: Status 829 * 830 * DESCRIPTION: Store the Buffer contents into the given field 831 * 832 ******************************************************************************/ 833 834 acpi_status 835 acpi_ex_insert_into_field(union acpi_operand_object *obj_desc, 836 void *buffer, u32 buffer_length) 837 { 838 void *new_buffer; 839 acpi_status status; 840 u64 mask; 841 u64 width_mask; 842 u64 merged_datum; 843 u64 raw_datum = 0; 844 u32 field_offset = 0; 845 u32 buffer_offset = 0; 846 u32 buffer_tail_bits; 847 u32 datum_count; 848 u32 field_datum_count; 849 u32 access_bit_width; 850 u32 required_length; 851 u32 i; 852 853 ACPI_FUNCTION_TRACE(ex_insert_into_field); 854 855 /* Validate input buffer */ 856 857 new_buffer = NULL; 858 required_length = 859 ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length); 860 /* 861 * We must have a buffer that is at least as long as the field 862 * we are writing to. This is because individual fields are 863 * indivisible and partial writes are not supported -- as per 864 * the ACPI specification. 865 */ 866 if (buffer_length < required_length) { 867 868 /* We need to create a new buffer */ 869 870 new_buffer = ACPI_ALLOCATE_ZEROED(required_length); 871 if (!new_buffer) { 872 return_ACPI_STATUS(AE_NO_MEMORY); 873 } 874 875 /* 876 * Copy the original data to the new buffer, starting 877 * at Byte zero. All unused (upper) bytes of the 878 * buffer will be 0. 879 */ 880 ACPI_MEMCPY((char *)new_buffer, (char *)buffer, buffer_length); 881 buffer = new_buffer; 882 buffer_length = required_length; 883 } 884 885 /* TBD: Move to common setup code */ 886 887 /* Algo is limited to sizeof(u64), so cut the access_byte_width */ 888 if (obj_desc->common_field.access_byte_width > sizeof(u64)) { 889 obj_desc->common_field.access_byte_width = sizeof(u64); 890 } 891 892 access_bit_width = ACPI_MUL_8(obj_desc->common_field.access_byte_width); 893 894 /* 895 * Create the bitmasks used for bit insertion. 896 * Note: This if/else is used to bypass compiler differences with the 897 * shift operator 898 */ 899 if (access_bit_width == ACPI_INTEGER_BIT_SIZE) { 900 width_mask = ACPI_UINT64_MAX; 901 } else { 902 width_mask = ACPI_MASK_BITS_ABOVE(access_bit_width); 903 } 904 905 mask = width_mask & 906 ACPI_MASK_BITS_BELOW(obj_desc->common_field.start_field_bit_offset); 907 908 /* Compute the number of datums (access width data items) */ 909 910 datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length, 911 access_bit_width); 912 913 field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length + 914 obj_desc->common_field. 915 start_field_bit_offset, 916 access_bit_width); 917 918 /* Get initial Datum from the input buffer */ 919 920 ACPI_MEMCPY(&raw_datum, buffer, 921 ACPI_MIN(obj_desc->common_field.access_byte_width, 922 buffer_length - buffer_offset)); 923 924 merged_datum = 925 raw_datum << obj_desc->common_field.start_field_bit_offset; 926 927 /* Write the entire field */ 928 929 for (i = 1; i < field_datum_count; i++) { 930 931 /* Write merged datum to the target field */ 932 933 merged_datum &= mask; 934 status = acpi_ex_write_with_update_rule(obj_desc, mask, 935 merged_datum, 936 field_offset); 937 if (ACPI_FAILURE(status)) { 938 goto exit; 939 } 940 941 field_offset += obj_desc->common_field.access_byte_width; 942 943 /* 944 * Start new output datum by merging with previous input datum 945 * if necessary. 946 * 947 * Note: Before the shift, check if the shift value will be larger than 948 * the integer size. If so, there is no need to perform the operation. 949 * This avoids the differences in behavior between different compilers 950 * concerning shift values larger than the target data width. 951 */ 952 if ((access_bit_width - 953 obj_desc->common_field.start_field_bit_offset) < 954 ACPI_INTEGER_BIT_SIZE) { 955 merged_datum = 956 raw_datum >> (access_bit_width - 957 obj_desc->common_field. 958 start_field_bit_offset); 959 } else { 960 merged_datum = 0; 961 } 962 963 mask = width_mask; 964 965 if (i == datum_count) { 966 break; 967 } 968 969 /* Get the next input datum from the buffer */ 970 971 buffer_offset += obj_desc->common_field.access_byte_width; 972 ACPI_MEMCPY(&raw_datum, ((char *)buffer) + buffer_offset, 973 ACPI_MIN(obj_desc->common_field.access_byte_width, 974 buffer_length - buffer_offset)); 975 976 merged_datum |= 977 raw_datum << obj_desc->common_field.start_field_bit_offset; 978 } 979 980 /* Mask off any extra bits in the last datum */ 981 982 buffer_tail_bits = (obj_desc->common_field.bit_length + 983 obj_desc->common_field.start_field_bit_offset) % 984 access_bit_width; 985 if (buffer_tail_bits) { 986 mask &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits); 987 } 988 989 /* Write the last datum to the field */ 990 991 merged_datum &= mask; 992 status = acpi_ex_write_with_update_rule(obj_desc, 993 mask, merged_datum, 994 field_offset); 995 996 exit: 997 /* Free temporary buffer if we used one */ 998 999 if (new_buffer) { 1000 ACPI_FREE(new_buffer); 1001 } 1002 return_ACPI_STATUS(status); 1003 } 1004