1 /****************************************************************************** 2 * 3 * Module Name: exfldio - Aml Field I/O 4 * 5 *****************************************************************************/ 6 7 /* 8 * Copyright (C) 2000 - 2013, 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 { 332 333 if (obj_desc->common_field.bit_length >= ACPI_INTEGER_BIT_SIZE) { 334 /* 335 * The field is large enough to hold the maximum integer, so we can 336 * never overflow it. 337 */ 338 return (FALSE); 339 } 340 341 if (value >= ((u64) 1 << obj_desc->common_field.bit_length)) { 342 /* 343 * The Value is larger than the maximum value that can fit into 344 * the register. 345 */ 346 ACPI_ERROR((AE_INFO, 347 "Index value 0x%8.8X%8.8X overflows field width 0x%X", 348 ACPI_FORMAT_UINT64(value), 349 obj_desc->common_field.bit_length)); 350 351 return (TRUE); 352 } 353 354 /* The Value will fit into the field with no truncation */ 355 356 return (FALSE); 357 } 358 359 /******************************************************************************* 360 * 361 * FUNCTION: acpi_ex_field_datum_io 362 * 363 * PARAMETERS: obj_desc - Field to be read 364 * field_datum_byte_offset - Byte offset of this datum within the 365 * parent field 366 * value - Where to store value (must be 64 bits) 367 * read_write - Read or Write flag 368 * 369 * RETURN: Status 370 * 371 * DESCRIPTION: Read or Write a single datum of a field. The field_type is 372 * demultiplexed here to handle the different types of fields 373 * (buffer_field, region_field, index_field, bank_field) 374 * 375 ******************************************************************************/ 376 377 static acpi_status 378 acpi_ex_field_datum_io(union acpi_operand_object *obj_desc, 379 u32 field_datum_byte_offset, u64 *value, u32 read_write) 380 { 381 acpi_status status; 382 u64 local_value; 383 384 ACPI_FUNCTION_TRACE_U32(ex_field_datum_io, field_datum_byte_offset); 385 386 if (read_write == ACPI_READ) { 387 if (!value) { 388 local_value = 0; 389 390 /* To support reads without saving return value */ 391 value = &local_value; 392 } 393 394 /* Clear the entire return buffer first, [Very Important!] */ 395 396 *value = 0; 397 } 398 399 /* 400 * The four types of fields are: 401 * 402 * buffer_field - Read/write from/to a Buffer 403 * region_field - Read/write from/to a Operation Region. 404 * bank_field - Write to a Bank Register, then read/write from/to an 405 * operation_region 406 * index_field - Write to an Index Register, then read/write from/to a 407 * Data Register 408 */ 409 switch (obj_desc->common.type) { 410 case ACPI_TYPE_BUFFER_FIELD: 411 /* 412 * If the buffer_field arguments have not been previously evaluated, 413 * evaluate them now and save the results. 414 */ 415 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) { 416 status = acpi_ds_get_buffer_field_arguments(obj_desc); 417 if (ACPI_FAILURE(status)) { 418 return_ACPI_STATUS(status); 419 } 420 } 421 422 if (read_write == ACPI_READ) { 423 /* 424 * Copy the data from the source buffer. 425 * Length is the field width in bytes. 426 */ 427 ACPI_MEMCPY(value, 428 (obj_desc->buffer_field.buffer_obj)->buffer. 429 pointer + 430 obj_desc->buffer_field.base_byte_offset + 431 field_datum_byte_offset, 432 obj_desc->common_field.access_byte_width); 433 } else { 434 /* 435 * Copy the data to the target buffer. 436 * Length is the field width in bytes. 437 */ 438 ACPI_MEMCPY((obj_desc->buffer_field.buffer_obj)->buffer. 439 pointer + 440 obj_desc->buffer_field.base_byte_offset + 441 field_datum_byte_offset, value, 442 obj_desc->common_field.access_byte_width); 443 } 444 445 status = AE_OK; 446 break; 447 448 case ACPI_TYPE_LOCAL_BANK_FIELD: 449 /* 450 * Ensure that the bank_value is not beyond the capacity of 451 * the register 452 */ 453 if (acpi_ex_register_overflow(obj_desc->bank_field.bank_obj, 454 (u64) obj_desc->bank_field. 455 value)) { 456 return_ACPI_STATUS(AE_AML_REGISTER_LIMIT); 457 } 458 459 /* 460 * For bank_fields, we must write the bank_value to the bank_register 461 * (itself a region_field) before we can access the data. 462 */ 463 status = 464 acpi_ex_insert_into_field(obj_desc->bank_field.bank_obj, 465 &obj_desc->bank_field.value, 466 sizeof(obj_desc->bank_field. 467 value)); 468 if (ACPI_FAILURE(status)) { 469 return_ACPI_STATUS(status); 470 } 471 472 /* 473 * Now that the Bank has been selected, fall through to the 474 * region_field case and write the datum to the Operation Region 475 */ 476 477 /*lint -fallthrough */ 478 479 case ACPI_TYPE_LOCAL_REGION_FIELD: 480 /* 481 * For simple region_fields, we just directly access the owning 482 * Operation Region. 483 */ 484 status = 485 acpi_ex_access_region(obj_desc, field_datum_byte_offset, 486 value, read_write); 487 break; 488 489 case ACPI_TYPE_LOCAL_INDEX_FIELD: 490 /* 491 * Ensure that the index_value is not beyond the capacity of 492 * the register 493 */ 494 if (acpi_ex_register_overflow(obj_desc->index_field.index_obj, 495 (u64) obj_desc->index_field. 496 value)) { 497 return_ACPI_STATUS(AE_AML_REGISTER_LIMIT); 498 } 499 500 /* Write the index value to the index_register (itself a region_field) */ 501 502 field_datum_byte_offset += obj_desc->index_field.value; 503 504 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, 505 "Write to Index Register: Value %8.8X\n", 506 field_datum_byte_offset)); 507 508 status = 509 acpi_ex_insert_into_field(obj_desc->index_field.index_obj, 510 &field_datum_byte_offset, 511 sizeof(field_datum_byte_offset)); 512 if (ACPI_FAILURE(status)) { 513 return_ACPI_STATUS(status); 514 } 515 516 if (read_write == ACPI_READ) { 517 518 /* Read the datum from the data_register */ 519 520 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, 521 "Read from Data Register\n")); 522 523 status = 524 acpi_ex_extract_from_field(obj_desc->index_field. 525 data_obj, value, 526 sizeof(u64)); 527 } else { 528 /* Write the datum to the data_register */ 529 530 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, 531 "Write to Data Register: Value %8.8X%8.8X\n", 532 ACPI_FORMAT_UINT64(*value))); 533 534 status = 535 acpi_ex_insert_into_field(obj_desc->index_field. 536 data_obj, value, 537 sizeof(u64)); 538 } 539 break; 540 541 default: 542 543 ACPI_ERROR((AE_INFO, "Wrong object type in field I/O %u", 544 obj_desc->common.type)); 545 status = AE_AML_INTERNAL; 546 break; 547 } 548 549 if (ACPI_SUCCESS(status)) { 550 if (read_write == ACPI_READ) { 551 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, 552 "Value Read %8.8X%8.8X, Width %u\n", 553 ACPI_FORMAT_UINT64(*value), 554 obj_desc->common_field. 555 access_byte_width)); 556 } else { 557 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, 558 "Value Written %8.8X%8.8X, Width %u\n", 559 ACPI_FORMAT_UINT64(*value), 560 obj_desc->common_field. 561 access_byte_width)); 562 } 563 } 564 565 return_ACPI_STATUS(status); 566 } 567 568 /******************************************************************************* 569 * 570 * FUNCTION: acpi_ex_write_with_update_rule 571 * 572 * PARAMETERS: obj_desc - Field to be written 573 * mask - bitmask within field datum 574 * field_value - Value to write 575 * field_datum_byte_offset - Offset of datum within field 576 * 577 * RETURN: Status 578 * 579 * DESCRIPTION: Apply the field update rule to a field write 580 * 581 ******************************************************************************/ 582 583 acpi_status 584 acpi_ex_write_with_update_rule(union acpi_operand_object *obj_desc, 585 u64 mask, 586 u64 field_value, u32 field_datum_byte_offset) 587 { 588 acpi_status status = AE_OK; 589 u64 merged_value; 590 u64 current_value; 591 592 ACPI_FUNCTION_TRACE_U32(ex_write_with_update_rule, mask); 593 594 /* Start with the new bits */ 595 596 merged_value = field_value; 597 598 /* If the mask is all ones, we don't need to worry about the update rule */ 599 600 if (mask != ACPI_UINT64_MAX) { 601 602 /* Decode the update rule */ 603 604 switch (obj_desc->common_field. 605 field_flags & AML_FIELD_UPDATE_RULE_MASK) { 606 case AML_FIELD_UPDATE_PRESERVE: 607 /* 608 * Check if update rule needs to be applied (not if mask is all 609 * ones) The left shift drops the bits we want to ignore. 610 */ 611 if ((~mask << (ACPI_MUL_8(sizeof(mask)) - 612 ACPI_MUL_8(obj_desc->common_field. 613 access_byte_width))) != 0) { 614 /* 615 * Read the current contents of the byte/word/dword containing 616 * the field, and merge with the new field value. 617 */ 618 status = 619 acpi_ex_field_datum_io(obj_desc, 620 field_datum_byte_offset, 621 ¤t_value, 622 ACPI_READ); 623 if (ACPI_FAILURE(status)) { 624 return_ACPI_STATUS(status); 625 } 626 627 merged_value |= (current_value & ~mask); 628 } 629 break; 630 631 case AML_FIELD_UPDATE_WRITE_AS_ONES: 632 633 /* Set positions outside the field to all ones */ 634 635 merged_value |= ~mask; 636 break; 637 638 case AML_FIELD_UPDATE_WRITE_AS_ZEROS: 639 640 /* Set positions outside the field to all zeros */ 641 642 merged_value &= mask; 643 break; 644 645 default: 646 647 ACPI_ERROR((AE_INFO, 648 "Unknown UpdateRule value: 0x%X", 649 (obj_desc->common_field. 650 field_flags & 651 AML_FIELD_UPDATE_RULE_MASK))); 652 return_ACPI_STATUS(AE_AML_OPERAND_VALUE); 653 } 654 } 655 656 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, 657 "Mask %8.8X%8.8X, DatumOffset %X, Width %X, Value %8.8X%8.8X, MergedValue %8.8X%8.8X\n", 658 ACPI_FORMAT_UINT64(mask), 659 field_datum_byte_offset, 660 obj_desc->common_field.access_byte_width, 661 ACPI_FORMAT_UINT64(field_value), 662 ACPI_FORMAT_UINT64(merged_value))); 663 664 /* Write the merged value */ 665 666 status = acpi_ex_field_datum_io(obj_desc, field_datum_byte_offset, 667 &merged_value, ACPI_WRITE); 668 669 return_ACPI_STATUS(status); 670 } 671 672 /******************************************************************************* 673 * 674 * FUNCTION: acpi_ex_extract_from_field 675 * 676 * PARAMETERS: obj_desc - Field to be read 677 * buffer - Where to store the field data 678 * buffer_length - Length of Buffer 679 * 680 * RETURN: Status 681 * 682 * DESCRIPTION: Retrieve the current value of the given field 683 * 684 ******************************************************************************/ 685 686 acpi_status 687 acpi_ex_extract_from_field(union acpi_operand_object *obj_desc, 688 void *buffer, u32 buffer_length) 689 { 690 acpi_status status; 691 u64 raw_datum; 692 u64 merged_datum; 693 u32 field_offset = 0; 694 u32 buffer_offset = 0; 695 u32 buffer_tail_bits; 696 u32 datum_count; 697 u32 field_datum_count; 698 u32 access_bit_width; 699 u32 i; 700 701 ACPI_FUNCTION_TRACE(ex_extract_from_field); 702 703 /* Validate target buffer and clear it */ 704 705 if (buffer_length < 706 ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length)) { 707 ACPI_ERROR((AE_INFO, 708 "Field size %u (bits) is too large for buffer (%u)", 709 obj_desc->common_field.bit_length, buffer_length)); 710 711 return_ACPI_STATUS(AE_BUFFER_OVERFLOW); 712 } 713 714 ACPI_MEMSET(buffer, 0, buffer_length); 715 access_bit_width = ACPI_MUL_8(obj_desc->common_field.access_byte_width); 716 717 /* Handle the simple case here */ 718 719 if ((obj_desc->common_field.start_field_bit_offset == 0) && 720 (obj_desc->common_field.bit_length == access_bit_width)) { 721 if (buffer_length >= sizeof(u64)) { 722 status = 723 acpi_ex_field_datum_io(obj_desc, 0, buffer, 724 ACPI_READ); 725 } else { 726 /* Use raw_datum (u64) to handle buffers < 64 bits */ 727 728 status = 729 acpi_ex_field_datum_io(obj_desc, 0, &raw_datum, 730 ACPI_READ); 731 ACPI_MEMCPY(buffer, &raw_datum, buffer_length); 732 } 733 734 return_ACPI_STATUS(status); 735 } 736 737 /* TBD: Move to common setup code */ 738 739 /* Field algorithm is limited to sizeof(u64), truncate if needed */ 740 741 if (obj_desc->common_field.access_byte_width > sizeof(u64)) { 742 obj_desc->common_field.access_byte_width = sizeof(u64); 743 access_bit_width = sizeof(u64) * 8; 744 } 745 746 /* Compute the number of datums (access width data items) */ 747 748 datum_count = 749 ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length, 750 access_bit_width); 751 752 field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length + 753 obj_desc->common_field. 754 start_field_bit_offset, 755 access_bit_width); 756 757 /* Priming read from the field */ 758 759 status = 760 acpi_ex_field_datum_io(obj_desc, field_offset, &raw_datum, 761 ACPI_READ); 762 if (ACPI_FAILURE(status)) { 763 return_ACPI_STATUS(status); 764 } 765 merged_datum = 766 raw_datum >> obj_desc->common_field.start_field_bit_offset; 767 768 /* Read the rest of the field */ 769 770 for (i = 1; i < field_datum_count; i++) { 771 772 /* Get next input datum from the field */ 773 774 field_offset += obj_desc->common_field.access_byte_width; 775 status = acpi_ex_field_datum_io(obj_desc, field_offset, 776 &raw_datum, ACPI_READ); 777 if (ACPI_FAILURE(status)) { 778 return_ACPI_STATUS(status); 779 } 780 781 /* 782 * Merge with previous datum if necessary. 783 * 784 * Note: Before the shift, check if the shift value will be larger than 785 * the integer size. If so, there is no need to perform the operation. 786 * This avoids the differences in behavior between different compilers 787 * concerning shift values larger than the target data width. 788 */ 789 if (access_bit_width - 790 obj_desc->common_field.start_field_bit_offset < 791 ACPI_INTEGER_BIT_SIZE) { 792 merged_datum |= 793 raw_datum << (access_bit_width - 794 obj_desc->common_field. 795 start_field_bit_offset); 796 } 797 798 if (i == datum_count) { 799 break; 800 } 801 802 /* Write merged datum to target buffer */ 803 804 ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum, 805 ACPI_MIN(obj_desc->common_field.access_byte_width, 806 buffer_length - buffer_offset)); 807 808 buffer_offset += obj_desc->common_field.access_byte_width; 809 merged_datum = 810 raw_datum >> obj_desc->common_field.start_field_bit_offset; 811 } 812 813 /* Mask off any extra bits in the last datum */ 814 815 buffer_tail_bits = obj_desc->common_field.bit_length % access_bit_width; 816 if (buffer_tail_bits) { 817 merged_datum &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits); 818 } 819 820 /* Write the last datum to the buffer */ 821 822 ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum, 823 ACPI_MIN(obj_desc->common_field.access_byte_width, 824 buffer_length - buffer_offset)); 825 826 return_ACPI_STATUS(AE_OK); 827 } 828 829 /******************************************************************************* 830 * 831 * FUNCTION: acpi_ex_insert_into_field 832 * 833 * PARAMETERS: obj_desc - Field to be written 834 * buffer - Data to be written 835 * buffer_length - Length of Buffer 836 * 837 * RETURN: Status 838 * 839 * DESCRIPTION: Store the Buffer contents into the given field 840 * 841 ******************************************************************************/ 842 843 acpi_status 844 acpi_ex_insert_into_field(union acpi_operand_object *obj_desc, 845 void *buffer, u32 buffer_length) 846 { 847 void *new_buffer; 848 acpi_status status; 849 u64 mask; 850 u64 width_mask; 851 u64 merged_datum; 852 u64 raw_datum = 0; 853 u32 field_offset = 0; 854 u32 buffer_offset = 0; 855 u32 buffer_tail_bits; 856 u32 datum_count; 857 u32 field_datum_count; 858 u32 access_bit_width; 859 u32 required_length; 860 u32 i; 861 862 ACPI_FUNCTION_TRACE(ex_insert_into_field); 863 864 /* Validate input buffer */ 865 866 new_buffer = NULL; 867 required_length = 868 ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length); 869 /* 870 * We must have a buffer that is at least as long as the field 871 * we are writing to. This is because individual fields are 872 * indivisible and partial writes are not supported -- as per 873 * the ACPI specification. 874 */ 875 if (buffer_length < required_length) { 876 877 /* We need to create a new buffer */ 878 879 new_buffer = ACPI_ALLOCATE_ZEROED(required_length); 880 if (!new_buffer) { 881 return_ACPI_STATUS(AE_NO_MEMORY); 882 } 883 884 /* 885 * Copy the original data to the new buffer, starting 886 * at Byte zero. All unused (upper) bytes of the 887 * buffer will be 0. 888 */ 889 ACPI_MEMCPY((char *)new_buffer, (char *)buffer, buffer_length); 890 buffer = new_buffer; 891 buffer_length = required_length; 892 } 893 894 /* TBD: Move to common setup code */ 895 896 /* Algo is limited to sizeof(u64), so cut the access_byte_width */ 897 if (obj_desc->common_field.access_byte_width > sizeof(u64)) { 898 obj_desc->common_field.access_byte_width = sizeof(u64); 899 } 900 901 access_bit_width = ACPI_MUL_8(obj_desc->common_field.access_byte_width); 902 903 /* 904 * Create the bitmasks used for bit insertion. 905 * Note: This if/else is used to bypass compiler differences with the 906 * shift operator 907 */ 908 if (access_bit_width == ACPI_INTEGER_BIT_SIZE) { 909 width_mask = ACPI_UINT64_MAX; 910 } else { 911 width_mask = ACPI_MASK_BITS_ABOVE(access_bit_width); 912 } 913 914 mask = width_mask & 915 ACPI_MASK_BITS_BELOW(obj_desc->common_field.start_field_bit_offset); 916 917 /* Compute the number of datums (access width data items) */ 918 919 datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length, 920 access_bit_width); 921 922 field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length + 923 obj_desc->common_field. 924 start_field_bit_offset, 925 access_bit_width); 926 927 /* Get initial Datum from the input buffer */ 928 929 ACPI_MEMCPY(&raw_datum, buffer, 930 ACPI_MIN(obj_desc->common_field.access_byte_width, 931 buffer_length - buffer_offset)); 932 933 merged_datum = 934 raw_datum << obj_desc->common_field.start_field_bit_offset; 935 936 /* Write the entire field */ 937 938 for (i = 1; i < field_datum_count; i++) { 939 940 /* Write merged datum to the target field */ 941 942 merged_datum &= mask; 943 status = acpi_ex_write_with_update_rule(obj_desc, mask, 944 merged_datum, 945 field_offset); 946 if (ACPI_FAILURE(status)) { 947 goto exit; 948 } 949 950 field_offset += obj_desc->common_field.access_byte_width; 951 952 /* 953 * Start new output datum by merging with previous input datum 954 * if necessary. 955 * 956 * Note: Before the shift, check if the shift value will be larger than 957 * the integer size. If so, there is no need to perform the operation. 958 * This avoids the differences in behavior between different compilers 959 * concerning shift values larger than the target data width. 960 */ 961 if ((access_bit_width - 962 obj_desc->common_field.start_field_bit_offset) < 963 ACPI_INTEGER_BIT_SIZE) { 964 merged_datum = 965 raw_datum >> (access_bit_width - 966 obj_desc->common_field. 967 start_field_bit_offset); 968 } else { 969 merged_datum = 0; 970 } 971 972 mask = width_mask; 973 974 if (i == datum_count) { 975 break; 976 } 977 978 /* Get the next input datum from the buffer */ 979 980 buffer_offset += obj_desc->common_field.access_byte_width; 981 ACPI_MEMCPY(&raw_datum, ((char *)buffer) + buffer_offset, 982 ACPI_MIN(obj_desc->common_field.access_byte_width, 983 buffer_length - buffer_offset)); 984 985 merged_datum |= 986 raw_datum << obj_desc->common_field.start_field_bit_offset; 987 } 988 989 /* Mask off any extra bits in the last datum */ 990 991 buffer_tail_bits = (obj_desc->common_field.bit_length + 992 obj_desc->common_field.start_field_bit_offset) % 993 access_bit_width; 994 if (buffer_tail_bits) { 995 mask &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits); 996 } 997 998 /* Write the last datum to the field */ 999 1000 merged_datum &= mask; 1001 status = acpi_ex_write_with_update_rule(obj_desc, 1002 mask, merged_datum, 1003 field_offset); 1004 1005 exit: 1006 /* Free temporary buffer if we used one */ 1007 1008 if (new_buffer) { 1009 ACPI_FREE(new_buffer); 1010 } 1011 return_ACPI_STATUS(status); 1012 } 1013