1 /****************************************************************************** 2 * 3 * Module Name: exfldio - Aml Field I/O 4 * 5 *****************************************************************************/ 6 7 /* 8 * Copyright (C) 2000 - 2014, 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 /* 127 * Exit now for SMBus, GSBus or IPMI address space, it has a non-linear 128 * address space and the request cannot be directly validated 129 */ 130 if (space_id == ACPI_ADR_SPACE_SMBUS || 131 space_id == ACPI_ADR_SPACE_GSBUS || 132 space_id == ACPI_ADR_SPACE_IPMI) { 133 134 /* SMBus or IPMI has a non-linear address space */ 135 136 return_ACPI_STATUS(AE_OK); 137 } 138 #ifdef ACPI_UNDER_DEVELOPMENT 139 /* 140 * If the Field access is any_acc, we can now compute the optimal 141 * access (because we know know the length of the parent region) 142 */ 143 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) { 144 if (ACPI_FAILURE(status)) { 145 return_ACPI_STATUS(status); 146 } 147 } 148 #endif 149 150 /* 151 * Validate the request. The entire request from the byte offset for a 152 * length of one field datum (access width) must fit within the region. 153 * (Region length is specified in bytes) 154 */ 155 if (rgn_desc->region.length < 156 (obj_desc->common_field.base_byte_offset + field_datum_byte_offset + 157 obj_desc->common_field.access_byte_width)) { 158 if (acpi_gbl_enable_interpreter_slack) { 159 /* 160 * Slack mode only: We will go ahead and allow access to this 161 * field if it is within the region length rounded up to the next 162 * access width boundary. acpi_size cast for 64-bit compile. 163 */ 164 if (ACPI_ROUND_UP(rgn_desc->region.length, 165 obj_desc->common_field. 166 access_byte_width) >= 167 ((acpi_size) obj_desc->common_field. 168 base_byte_offset + 169 obj_desc->common_field.access_byte_width + 170 field_datum_byte_offset)) { 171 return_ACPI_STATUS(AE_OK); 172 } 173 } 174 175 if (rgn_desc->region.length < 176 obj_desc->common_field.access_byte_width) { 177 /* 178 * This is the case where the access_type (acc_word, etc.) is wider 179 * than the region itself. For example, a region of length one 180 * byte, and a field with Dword access specified. 181 */ 182 ACPI_ERROR((AE_INFO, 183 "Field [%4.4s] access width (%u bytes) too large for region [%4.4s] (length %u)", 184 acpi_ut_get_node_name(obj_desc-> 185 common_field.node), 186 obj_desc->common_field.access_byte_width, 187 acpi_ut_get_node_name(rgn_desc->region. 188 node), 189 rgn_desc->region.length)); 190 } 191 192 /* 193 * Offset rounded up to next multiple of field width 194 * exceeds region length, indicate an error 195 */ 196 ACPI_ERROR((AE_INFO, 197 "Field [%4.4s] Base+Offset+Width %u+%u+%u is beyond end of region [%4.4s] (length %u)", 198 acpi_ut_get_node_name(obj_desc->common_field.node), 199 obj_desc->common_field.base_byte_offset, 200 field_datum_byte_offset, 201 obj_desc->common_field.access_byte_width, 202 acpi_ut_get_node_name(rgn_desc->region.node), 203 rgn_desc->region.length)); 204 205 return_ACPI_STATUS(AE_AML_REGION_LIMIT); 206 } 207 208 return_ACPI_STATUS(AE_OK); 209 } 210 211 /******************************************************************************* 212 * 213 * FUNCTION: acpi_ex_access_region 214 * 215 * PARAMETERS: obj_desc - Field to be read 216 * field_datum_byte_offset - Byte offset of this datum within the 217 * parent field 218 * value - Where to store value (must at least 219 * 64 bits) 220 * function - Read or Write flag plus other region- 221 * dependent flags 222 * 223 * RETURN: Status 224 * 225 * DESCRIPTION: Read or Write a single field datum to an Operation Region. 226 * 227 ******************************************************************************/ 228 229 acpi_status 230 acpi_ex_access_region(union acpi_operand_object *obj_desc, 231 u32 field_datum_byte_offset, u64 *value, u32 function) 232 { 233 acpi_status status; 234 union acpi_operand_object *rgn_desc; 235 u32 region_offset; 236 237 ACPI_FUNCTION_TRACE(ex_access_region); 238 239 /* 240 * Ensure that the region operands are fully evaluated and verify 241 * the validity of the request 242 */ 243 status = acpi_ex_setup_region(obj_desc, field_datum_byte_offset); 244 if (ACPI_FAILURE(status)) { 245 return_ACPI_STATUS(status); 246 } 247 248 /* 249 * The physical address of this field datum is: 250 * 251 * 1) The base of the region, plus 252 * 2) The base offset of the field, plus 253 * 3) The current offset into the field 254 */ 255 rgn_desc = obj_desc->common_field.region_obj; 256 region_offset = 257 obj_desc->common_field.base_byte_offset + field_datum_byte_offset; 258 259 if ((function & ACPI_IO_MASK) == ACPI_READ) { 260 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[READ]")); 261 } else { 262 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "[WRITE]")); 263 } 264 265 ACPI_DEBUG_PRINT_RAW((ACPI_DB_BFIELD, 266 " Region [%s:%X], Width %X, ByteBase %X, Offset %X at %p\n", 267 acpi_ut_get_region_name(rgn_desc->region. 268 space_id), 269 rgn_desc->region.space_id, 270 obj_desc->common_field.access_byte_width, 271 obj_desc->common_field.base_byte_offset, 272 field_datum_byte_offset, ACPI_CAST_PTR(void, 273 (rgn_desc-> 274 region. 275 address + 276 region_offset)))); 277 278 /* Invoke the appropriate address_space/op_region handler */ 279 280 status = acpi_ev_address_space_dispatch(rgn_desc, obj_desc, 281 function, region_offset, 282 ACPI_MUL_8(obj_desc-> 283 common_field. 284 access_byte_width), 285 value); 286 287 if (ACPI_FAILURE(status)) { 288 if (status == AE_NOT_IMPLEMENTED) { 289 ACPI_ERROR((AE_INFO, 290 "Region %s (ID=%u) not implemented", 291 acpi_ut_get_region_name(rgn_desc->region. 292 space_id), 293 rgn_desc->region.space_id)); 294 } else if (status == AE_NOT_EXIST) { 295 ACPI_ERROR((AE_INFO, 296 "Region %s (ID=%u) has no handler", 297 acpi_ut_get_region_name(rgn_desc->region. 298 space_id), 299 rgn_desc->region.space_id)); 300 } 301 } 302 303 return_ACPI_STATUS(status); 304 } 305 306 /******************************************************************************* 307 * 308 * FUNCTION: acpi_ex_register_overflow 309 * 310 * PARAMETERS: obj_desc - Register(Field) to be written 311 * value - Value to be stored 312 * 313 * RETURN: TRUE if value overflows the field, FALSE otherwise 314 * 315 * DESCRIPTION: Check if a value is out of range of the field being written. 316 * Used to check if the values written to Index and Bank registers 317 * are out of range. Normally, the value is simply truncated 318 * to fit the field, but this case is most likely a serious 319 * coding error in the ASL. 320 * 321 ******************************************************************************/ 322 323 static u8 324 acpi_ex_register_overflow(union acpi_operand_object *obj_desc, u64 value) 325 { 326 327 if (obj_desc->common_field.bit_length >= ACPI_INTEGER_BIT_SIZE) { 328 /* 329 * The field is large enough to hold the maximum integer, so we can 330 * never overflow it. 331 */ 332 return (FALSE); 333 } 334 335 if (value >= ((u64) 1 << obj_desc->common_field.bit_length)) { 336 /* 337 * The Value is larger than the maximum value that can fit into 338 * the register. 339 */ 340 ACPI_ERROR((AE_INFO, 341 "Index value 0x%8.8X%8.8X overflows field width 0x%X", 342 ACPI_FORMAT_UINT64(value), 343 obj_desc->common_field.bit_length)); 344 345 return (TRUE); 346 } 347 348 /* The Value will fit into the field with no truncation */ 349 350 return (FALSE); 351 } 352 353 /******************************************************************************* 354 * 355 * FUNCTION: acpi_ex_field_datum_io 356 * 357 * PARAMETERS: obj_desc - Field to be read 358 * field_datum_byte_offset - Byte offset of this datum within the 359 * parent field 360 * value - Where to store value (must be 64 bits) 361 * read_write - Read or Write flag 362 * 363 * RETURN: Status 364 * 365 * DESCRIPTION: Read or Write a single datum of a field. The field_type is 366 * demultiplexed here to handle the different types of fields 367 * (buffer_field, region_field, index_field, bank_field) 368 * 369 ******************************************************************************/ 370 371 static acpi_status 372 acpi_ex_field_datum_io(union acpi_operand_object *obj_desc, 373 u32 field_datum_byte_offset, u64 *value, u32 read_write) 374 { 375 acpi_status status; 376 u64 local_value; 377 378 ACPI_FUNCTION_TRACE_U32(ex_field_datum_io, field_datum_byte_offset); 379 380 if (read_write == ACPI_READ) { 381 if (!value) { 382 local_value = 0; 383 384 /* To support reads without saving return value */ 385 value = &local_value; 386 } 387 388 /* Clear the entire return buffer first, [Very Important!] */ 389 390 *value = 0; 391 } 392 393 /* 394 * The four types of fields are: 395 * 396 * buffer_field - Read/write from/to a Buffer 397 * region_field - Read/write from/to a Operation Region. 398 * bank_field - Write to a Bank Register, then read/write from/to an 399 * operation_region 400 * index_field - Write to an Index Register, then read/write from/to a 401 * Data Register 402 */ 403 switch (obj_desc->common.type) { 404 case ACPI_TYPE_BUFFER_FIELD: 405 /* 406 * If the buffer_field arguments have not been previously evaluated, 407 * evaluate them now and save the results. 408 */ 409 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) { 410 status = acpi_ds_get_buffer_field_arguments(obj_desc); 411 if (ACPI_FAILURE(status)) { 412 return_ACPI_STATUS(status); 413 } 414 } 415 416 if (read_write == ACPI_READ) { 417 /* 418 * Copy the data from the source buffer. 419 * Length is the field width in bytes. 420 */ 421 ACPI_MEMCPY(value, 422 (obj_desc->buffer_field.buffer_obj)->buffer. 423 pointer + 424 obj_desc->buffer_field.base_byte_offset + 425 field_datum_byte_offset, 426 obj_desc->common_field.access_byte_width); 427 } else { 428 /* 429 * Copy the data to the target buffer. 430 * Length is the field width in bytes. 431 */ 432 ACPI_MEMCPY((obj_desc->buffer_field.buffer_obj)->buffer. 433 pointer + 434 obj_desc->buffer_field.base_byte_offset + 435 field_datum_byte_offset, value, 436 obj_desc->common_field.access_byte_width); 437 } 438 439 status = AE_OK; 440 break; 441 442 case ACPI_TYPE_LOCAL_BANK_FIELD: 443 /* 444 * Ensure that the bank_value is not beyond the capacity of 445 * the register 446 */ 447 if (acpi_ex_register_overflow(obj_desc->bank_field.bank_obj, 448 (u64) obj_desc->bank_field. 449 value)) { 450 return_ACPI_STATUS(AE_AML_REGISTER_LIMIT); 451 } 452 453 /* 454 * For bank_fields, we must write the bank_value to the bank_register 455 * (itself a region_field) before we can access the data. 456 */ 457 status = 458 acpi_ex_insert_into_field(obj_desc->bank_field.bank_obj, 459 &obj_desc->bank_field.value, 460 sizeof(obj_desc->bank_field. 461 value)); 462 if (ACPI_FAILURE(status)) { 463 return_ACPI_STATUS(status); 464 } 465 466 /* 467 * Now that the Bank has been selected, fall through to the 468 * region_field case and write the datum to the Operation Region 469 */ 470 471 /*lint -fallthrough */ 472 473 case ACPI_TYPE_LOCAL_REGION_FIELD: 474 /* 475 * For simple region_fields, we just directly access the owning 476 * Operation Region. 477 */ 478 status = 479 acpi_ex_access_region(obj_desc, field_datum_byte_offset, 480 value, read_write); 481 break; 482 483 case ACPI_TYPE_LOCAL_INDEX_FIELD: 484 /* 485 * Ensure that the index_value is not beyond the capacity of 486 * the register 487 */ 488 if (acpi_ex_register_overflow(obj_desc->index_field.index_obj, 489 (u64) obj_desc->index_field. 490 value)) { 491 return_ACPI_STATUS(AE_AML_REGISTER_LIMIT); 492 } 493 494 /* Write the index value to the index_register (itself a region_field) */ 495 496 field_datum_byte_offset += obj_desc->index_field.value; 497 498 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, 499 "Write to Index Register: Value %8.8X\n", 500 field_datum_byte_offset)); 501 502 status = 503 acpi_ex_insert_into_field(obj_desc->index_field.index_obj, 504 &field_datum_byte_offset, 505 sizeof(field_datum_byte_offset)); 506 if (ACPI_FAILURE(status)) { 507 return_ACPI_STATUS(status); 508 } 509 510 if (read_write == ACPI_READ) { 511 512 /* Read the datum from the data_register */ 513 514 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, 515 "Read from Data Register\n")); 516 517 status = 518 acpi_ex_extract_from_field(obj_desc->index_field. 519 data_obj, value, 520 sizeof(u64)); 521 } else { 522 /* Write the datum to the data_register */ 523 524 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, 525 "Write to Data Register: Value %8.8X%8.8X\n", 526 ACPI_FORMAT_UINT64(*value))); 527 528 status = 529 acpi_ex_insert_into_field(obj_desc->index_field. 530 data_obj, value, 531 sizeof(u64)); 532 } 533 break; 534 535 default: 536 537 ACPI_ERROR((AE_INFO, "Wrong object type in field I/O %u", 538 obj_desc->common.type)); 539 status = AE_AML_INTERNAL; 540 break; 541 } 542 543 if (ACPI_SUCCESS(status)) { 544 if (read_write == ACPI_READ) { 545 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, 546 "Value Read %8.8X%8.8X, Width %u\n", 547 ACPI_FORMAT_UINT64(*value), 548 obj_desc->common_field. 549 access_byte_width)); 550 } else { 551 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, 552 "Value Written %8.8X%8.8X, Width %u\n", 553 ACPI_FORMAT_UINT64(*value), 554 obj_desc->common_field. 555 access_byte_width)); 556 } 557 } 558 559 return_ACPI_STATUS(status); 560 } 561 562 /******************************************************************************* 563 * 564 * FUNCTION: acpi_ex_write_with_update_rule 565 * 566 * PARAMETERS: obj_desc - Field to be written 567 * mask - bitmask within field datum 568 * field_value - Value to write 569 * field_datum_byte_offset - Offset of datum within field 570 * 571 * RETURN: Status 572 * 573 * DESCRIPTION: Apply the field update rule to a field write 574 * 575 ******************************************************************************/ 576 577 acpi_status 578 acpi_ex_write_with_update_rule(union acpi_operand_object *obj_desc, 579 u64 mask, 580 u64 field_value, u32 field_datum_byte_offset) 581 { 582 acpi_status status = AE_OK; 583 u64 merged_value; 584 u64 current_value; 585 586 ACPI_FUNCTION_TRACE_U32(ex_write_with_update_rule, mask); 587 588 /* Start with the new bits */ 589 590 merged_value = field_value; 591 592 /* If the mask is all ones, we don't need to worry about the update rule */ 593 594 if (mask != ACPI_UINT64_MAX) { 595 596 /* Decode the update rule */ 597 598 switch (obj_desc->common_field. 599 field_flags & AML_FIELD_UPDATE_RULE_MASK) { 600 case AML_FIELD_UPDATE_PRESERVE: 601 /* 602 * Check if update rule needs to be applied (not if mask is all 603 * ones) The left shift drops the bits we want to ignore. 604 */ 605 if ((~mask << (ACPI_MUL_8(sizeof(mask)) - 606 ACPI_MUL_8(obj_desc->common_field. 607 access_byte_width))) != 0) { 608 /* 609 * Read the current contents of the byte/word/dword containing 610 * the field, and merge with the new field value. 611 */ 612 status = 613 acpi_ex_field_datum_io(obj_desc, 614 field_datum_byte_offset, 615 ¤t_value, 616 ACPI_READ); 617 if (ACPI_FAILURE(status)) { 618 return_ACPI_STATUS(status); 619 } 620 621 merged_value |= (current_value & ~mask); 622 } 623 break; 624 625 case AML_FIELD_UPDATE_WRITE_AS_ONES: 626 627 /* Set positions outside the field to all ones */ 628 629 merged_value |= ~mask; 630 break; 631 632 case AML_FIELD_UPDATE_WRITE_AS_ZEROS: 633 634 /* Set positions outside the field to all zeros */ 635 636 merged_value &= mask; 637 break; 638 639 default: 640 641 ACPI_ERROR((AE_INFO, 642 "Unknown UpdateRule value: 0x%X", 643 (obj_desc->common_field. 644 field_flags & 645 AML_FIELD_UPDATE_RULE_MASK))); 646 return_ACPI_STATUS(AE_AML_OPERAND_VALUE); 647 } 648 } 649 650 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, 651 "Mask %8.8X%8.8X, DatumOffset %X, Width %X, Value %8.8X%8.8X, MergedValue %8.8X%8.8X\n", 652 ACPI_FORMAT_UINT64(mask), 653 field_datum_byte_offset, 654 obj_desc->common_field.access_byte_width, 655 ACPI_FORMAT_UINT64(field_value), 656 ACPI_FORMAT_UINT64(merged_value))); 657 658 /* Write the merged value */ 659 660 status = acpi_ex_field_datum_io(obj_desc, field_datum_byte_offset, 661 &merged_value, ACPI_WRITE); 662 663 return_ACPI_STATUS(status); 664 } 665 666 /******************************************************************************* 667 * 668 * FUNCTION: acpi_ex_extract_from_field 669 * 670 * PARAMETERS: obj_desc - Field to be read 671 * buffer - Where to store the field data 672 * buffer_length - Length of Buffer 673 * 674 * RETURN: Status 675 * 676 * DESCRIPTION: Retrieve the current value of the given field 677 * 678 ******************************************************************************/ 679 680 acpi_status 681 acpi_ex_extract_from_field(union acpi_operand_object *obj_desc, 682 void *buffer, u32 buffer_length) 683 { 684 acpi_status status; 685 u64 raw_datum; 686 u64 merged_datum; 687 u32 field_offset = 0; 688 u32 buffer_offset = 0; 689 u32 buffer_tail_bits; 690 u32 datum_count; 691 u32 field_datum_count; 692 u32 access_bit_width; 693 u32 i; 694 695 ACPI_FUNCTION_TRACE(ex_extract_from_field); 696 697 /* Validate target buffer and clear it */ 698 699 if (buffer_length < 700 ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length)) { 701 ACPI_ERROR((AE_INFO, 702 "Field size %u (bits) is too large for buffer (%u)", 703 obj_desc->common_field.bit_length, buffer_length)); 704 705 return_ACPI_STATUS(AE_BUFFER_OVERFLOW); 706 } 707 708 ACPI_MEMSET(buffer, 0, buffer_length); 709 access_bit_width = ACPI_MUL_8(obj_desc->common_field.access_byte_width); 710 711 /* Handle the simple case here */ 712 713 if ((obj_desc->common_field.start_field_bit_offset == 0) && 714 (obj_desc->common_field.bit_length == access_bit_width)) { 715 if (buffer_length >= sizeof(u64)) { 716 status = 717 acpi_ex_field_datum_io(obj_desc, 0, buffer, 718 ACPI_READ); 719 } else { 720 /* Use raw_datum (u64) to handle buffers < 64 bits */ 721 722 status = 723 acpi_ex_field_datum_io(obj_desc, 0, &raw_datum, 724 ACPI_READ); 725 ACPI_MEMCPY(buffer, &raw_datum, buffer_length); 726 } 727 728 return_ACPI_STATUS(status); 729 } 730 731 /* TBD: Move to common setup code */ 732 733 /* Field algorithm is limited to sizeof(u64), truncate if needed */ 734 735 if (obj_desc->common_field.access_byte_width > sizeof(u64)) { 736 obj_desc->common_field.access_byte_width = sizeof(u64); 737 access_bit_width = sizeof(u64) * 8; 738 } 739 740 /* Compute the number of datums (access width data items) */ 741 742 datum_count = 743 ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length, 744 access_bit_width); 745 746 field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length + 747 obj_desc->common_field. 748 start_field_bit_offset, 749 access_bit_width); 750 751 /* Priming read from the field */ 752 753 status = 754 acpi_ex_field_datum_io(obj_desc, field_offset, &raw_datum, 755 ACPI_READ); 756 if (ACPI_FAILURE(status)) { 757 return_ACPI_STATUS(status); 758 } 759 merged_datum = 760 raw_datum >> obj_desc->common_field.start_field_bit_offset; 761 762 /* Read the rest of the field */ 763 764 for (i = 1; i < field_datum_count; i++) { 765 766 /* Get next input datum from the field */ 767 768 field_offset += obj_desc->common_field.access_byte_width; 769 status = acpi_ex_field_datum_io(obj_desc, field_offset, 770 &raw_datum, ACPI_READ); 771 if (ACPI_FAILURE(status)) { 772 return_ACPI_STATUS(status); 773 } 774 775 /* 776 * Merge with previous datum if necessary. 777 * 778 * Note: Before the shift, check if the shift value will be larger than 779 * the integer size. If so, there is no need to perform the operation. 780 * This avoids the differences in behavior between different compilers 781 * concerning shift values larger than the target data width. 782 */ 783 if (access_bit_width - 784 obj_desc->common_field.start_field_bit_offset < 785 ACPI_INTEGER_BIT_SIZE) { 786 merged_datum |= 787 raw_datum << (access_bit_width - 788 obj_desc->common_field. 789 start_field_bit_offset); 790 } 791 792 if (i == datum_count) { 793 break; 794 } 795 796 /* Write merged datum to target buffer */ 797 798 ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum, 799 ACPI_MIN(obj_desc->common_field.access_byte_width, 800 buffer_length - buffer_offset)); 801 802 buffer_offset += obj_desc->common_field.access_byte_width; 803 merged_datum = 804 raw_datum >> obj_desc->common_field.start_field_bit_offset; 805 } 806 807 /* Mask off any extra bits in the last datum */ 808 809 buffer_tail_bits = obj_desc->common_field.bit_length % access_bit_width; 810 if (buffer_tail_bits) { 811 merged_datum &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits); 812 } 813 814 /* Write the last datum to the buffer */ 815 816 ACPI_MEMCPY(((char *)buffer) + buffer_offset, &merged_datum, 817 ACPI_MIN(obj_desc->common_field.access_byte_width, 818 buffer_length - buffer_offset)); 819 820 return_ACPI_STATUS(AE_OK); 821 } 822 823 /******************************************************************************* 824 * 825 * FUNCTION: acpi_ex_insert_into_field 826 * 827 * PARAMETERS: obj_desc - Field to be written 828 * buffer - Data to be written 829 * buffer_length - Length of Buffer 830 * 831 * RETURN: Status 832 * 833 * DESCRIPTION: Store the Buffer contents into the given field 834 * 835 ******************************************************************************/ 836 837 acpi_status 838 acpi_ex_insert_into_field(union acpi_operand_object *obj_desc, 839 void *buffer, u32 buffer_length) 840 { 841 void *new_buffer; 842 acpi_status status; 843 u64 mask; 844 u64 width_mask; 845 u64 merged_datum; 846 u64 raw_datum = 0; 847 u32 field_offset = 0; 848 u32 buffer_offset = 0; 849 u32 buffer_tail_bits; 850 u32 datum_count; 851 u32 field_datum_count; 852 u32 access_bit_width; 853 u32 required_length; 854 u32 i; 855 856 ACPI_FUNCTION_TRACE(ex_insert_into_field); 857 858 /* Validate input buffer */ 859 860 new_buffer = NULL; 861 required_length = 862 ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length); 863 /* 864 * We must have a buffer that is at least as long as the field 865 * we are writing to. This is because individual fields are 866 * indivisible and partial writes are not supported -- as per 867 * the ACPI specification. 868 */ 869 if (buffer_length < required_length) { 870 871 /* We need to create a new buffer */ 872 873 new_buffer = ACPI_ALLOCATE_ZEROED(required_length); 874 if (!new_buffer) { 875 return_ACPI_STATUS(AE_NO_MEMORY); 876 } 877 878 /* 879 * Copy the original data to the new buffer, starting 880 * at Byte zero. All unused (upper) bytes of the 881 * buffer will be 0. 882 */ 883 ACPI_MEMCPY((char *)new_buffer, (char *)buffer, buffer_length); 884 buffer = new_buffer; 885 buffer_length = required_length; 886 } 887 888 /* TBD: Move to common setup code */ 889 890 /* Algo is limited to sizeof(u64), so cut the access_byte_width */ 891 if (obj_desc->common_field.access_byte_width > sizeof(u64)) { 892 obj_desc->common_field.access_byte_width = sizeof(u64); 893 } 894 895 access_bit_width = ACPI_MUL_8(obj_desc->common_field.access_byte_width); 896 897 /* 898 * Create the bitmasks used for bit insertion. 899 * Note: This if/else is used to bypass compiler differences with the 900 * shift operator 901 */ 902 if (access_bit_width == ACPI_INTEGER_BIT_SIZE) { 903 width_mask = ACPI_UINT64_MAX; 904 } else { 905 width_mask = ACPI_MASK_BITS_ABOVE(access_bit_width); 906 } 907 908 mask = width_mask & 909 ACPI_MASK_BITS_BELOW(obj_desc->common_field.start_field_bit_offset); 910 911 /* Compute the number of datums (access width data items) */ 912 913 datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length, 914 access_bit_width); 915 916 field_datum_count = ACPI_ROUND_UP_TO(obj_desc->common_field.bit_length + 917 obj_desc->common_field. 918 start_field_bit_offset, 919 access_bit_width); 920 921 /* Get initial Datum from the input buffer */ 922 923 ACPI_MEMCPY(&raw_datum, buffer, 924 ACPI_MIN(obj_desc->common_field.access_byte_width, 925 buffer_length - buffer_offset)); 926 927 merged_datum = 928 raw_datum << obj_desc->common_field.start_field_bit_offset; 929 930 /* Write the entire field */ 931 932 for (i = 1; i < field_datum_count; i++) { 933 934 /* Write merged datum to the target field */ 935 936 merged_datum &= mask; 937 status = acpi_ex_write_with_update_rule(obj_desc, mask, 938 merged_datum, 939 field_offset); 940 if (ACPI_FAILURE(status)) { 941 goto exit; 942 } 943 944 field_offset += obj_desc->common_field.access_byte_width; 945 946 /* 947 * Start new output datum by merging with previous input datum 948 * if necessary. 949 * 950 * Note: Before the shift, check if the shift value will be larger than 951 * the integer size. If so, there is no need to perform the operation. 952 * This avoids the differences in behavior between different compilers 953 * concerning shift values larger than the target data width. 954 */ 955 if ((access_bit_width - 956 obj_desc->common_field.start_field_bit_offset) < 957 ACPI_INTEGER_BIT_SIZE) { 958 merged_datum = 959 raw_datum >> (access_bit_width - 960 obj_desc->common_field. 961 start_field_bit_offset); 962 } else { 963 merged_datum = 0; 964 } 965 966 mask = width_mask; 967 968 if (i == datum_count) { 969 break; 970 } 971 972 /* Get the next input datum from the buffer */ 973 974 buffer_offset += obj_desc->common_field.access_byte_width; 975 ACPI_MEMCPY(&raw_datum, ((char *)buffer) + buffer_offset, 976 ACPI_MIN(obj_desc->common_field.access_byte_width, 977 buffer_length - buffer_offset)); 978 979 merged_datum |= 980 raw_datum << obj_desc->common_field.start_field_bit_offset; 981 } 982 983 /* Mask off any extra bits in the last datum */ 984 985 buffer_tail_bits = (obj_desc->common_field.bit_length + 986 obj_desc->common_field.start_field_bit_offset) % 987 access_bit_width; 988 if (buffer_tail_bits) { 989 mask &= ACPI_MASK_BITS_ABOVE(buffer_tail_bits); 990 } 991 992 /* Write the last datum to the field */ 993 994 merged_datum &= mask; 995 status = acpi_ex_write_with_update_rule(obj_desc, 996 mask, merged_datum, 997 field_offset); 998 999 exit: 1000 /* Free temporary buffer if we used one */ 1001 1002 if (new_buffer) { 1003 ACPI_FREE(new_buffer); 1004 } 1005 return_ACPI_STATUS(status); 1006 } 1007