1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0 2 /****************************************************************************** 3 * 4 * Module Name: exprep - ACPI AML field prep utilities 5 * 6 * Copyright (C) 2000 - 2023, Intel Corp. 7 * 8 *****************************************************************************/ 9 10 #include <acpi/acpi.h> 11 #include "accommon.h" 12 #include "acinterp.h" 13 #include "amlcode.h" 14 #include "acnamesp.h" 15 #include "acdispat.h" 16 17 #define _COMPONENT ACPI_EXECUTER 18 ACPI_MODULE_NAME("exprep") 19 20 /* Local prototypes */ 21 static u32 22 acpi_ex_decode_field_access(union acpi_operand_object *obj_desc, 23 u8 field_flags, u32 * return_byte_alignment); 24 25 #ifdef ACPI_UNDER_DEVELOPMENT 26 27 static u32 28 acpi_ex_generate_access(u32 field_bit_offset, 29 u32 field_bit_length, u32 region_length); 30 31 /******************************************************************************* 32 * 33 * FUNCTION: acpi_ex_generate_access 34 * 35 * PARAMETERS: field_bit_offset - Start of field within parent region/buffer 36 * field_bit_length - Length of field in bits 37 * region_length - Length of parent in bytes 38 * 39 * RETURN: Field granularity (8, 16, 32 or 64) and 40 * byte_alignment (1, 2, 3, or 4) 41 * 42 * DESCRIPTION: Generate an optimal access width for fields defined with the 43 * any_acc keyword. 44 * 45 * NOTE: Need to have the region_length in order to check for boundary 46 * conditions (end-of-region). However, the region_length is a deferred 47 * operation. Therefore, to complete this implementation, the generation 48 * of this access width must be deferred until the region length has 49 * been evaluated. 50 * 51 ******************************************************************************/ 52 53 static u32 54 acpi_ex_generate_access(u32 field_bit_offset, 55 u32 field_bit_length, u32 region_length) 56 { 57 u32 field_byte_length; 58 u32 field_byte_offset; 59 u32 field_byte_end_offset; 60 u32 access_byte_width; 61 u32 field_start_offset; 62 u32 field_end_offset; 63 u32 minimum_access_width = 0xFFFFFFFF; 64 u32 minimum_accesses = 0xFFFFFFFF; 65 u32 accesses; 66 67 ACPI_FUNCTION_TRACE(ex_generate_access); 68 69 /* Round Field start offset and length to "minimal" byte boundaries */ 70 71 field_byte_offset = ACPI_DIV_8(ACPI_ROUND_DOWN(field_bit_offset, 8)); 72 73 field_byte_end_offset = 74 ACPI_DIV_8(ACPI_ROUND_UP(field_bit_length + field_bit_offset, 8)); 75 76 field_byte_length = field_byte_end_offset - field_byte_offset; 77 78 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, 79 "Bit length %u, Bit offset %u\n", 80 field_bit_length, field_bit_offset)); 81 82 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, 83 "Byte Length %u, Byte Offset %u, End Offset %u\n", 84 field_byte_length, field_byte_offset, 85 field_byte_end_offset)); 86 87 /* 88 * Iterative search for the maximum access width that is both aligned 89 * and does not go beyond the end of the region 90 * 91 * Start at byte_acc and work upwards to qword_acc max. (1,2,4,8 bytes) 92 */ 93 for (access_byte_width = 1; access_byte_width <= 8; 94 access_byte_width <<= 1) { 95 /* 96 * 1) Round end offset up to next access boundary and make sure that 97 * this does not go beyond the end of the parent region. 98 * 2) When the Access width is greater than the field_byte_length, we 99 * are done. (This does not optimize for the perfectly aligned 100 * case yet). 101 */ 102 if (ACPI_ROUND_UP(field_byte_end_offset, access_byte_width) <= 103 region_length) { 104 field_start_offset = 105 ACPI_ROUND_DOWN(field_byte_offset, 106 access_byte_width) / 107 access_byte_width; 108 109 field_end_offset = 110 ACPI_ROUND_UP((field_byte_length + 111 field_byte_offset), 112 access_byte_width) / 113 access_byte_width; 114 115 accesses = field_end_offset - field_start_offset; 116 117 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, 118 "AccessWidth %u end is within region\n", 119 access_byte_width)); 120 121 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, 122 "Field Start %u, Field End %u -- requires %u accesses\n", 123 field_start_offset, field_end_offset, 124 accesses)); 125 126 /* Single access is optimal */ 127 128 if (accesses <= 1) { 129 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, 130 "Entire field can be accessed " 131 "with one operation of size %u\n", 132 access_byte_width)); 133 return_VALUE(access_byte_width); 134 } 135 136 /* 137 * Fits in the region, but requires more than one read/write. 138 * try the next wider access on next iteration 139 */ 140 if (accesses < minimum_accesses) { 141 minimum_accesses = accesses; 142 minimum_access_width = access_byte_width; 143 } 144 } else { 145 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, 146 "AccessWidth %u end is NOT within region\n", 147 access_byte_width)); 148 if (access_byte_width == 1) { 149 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, 150 "Field goes beyond end-of-region!\n")); 151 152 /* Field does not fit in the region at all */ 153 154 return_VALUE(0); 155 } 156 157 /* 158 * This width goes beyond the end-of-region, back off to 159 * previous access 160 */ 161 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, 162 "Backing off to previous optimal access width of %u\n", 163 minimum_access_width)); 164 return_VALUE(minimum_access_width); 165 } 166 } 167 168 /* 169 * Could not read/write field with one operation, 170 * just use max access width 171 */ 172 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, 173 "Cannot access field in one operation, using width 8\n")); 174 175 return_VALUE(8); 176 } 177 #endif /* ACPI_UNDER_DEVELOPMENT */ 178 179 /******************************************************************************* 180 * 181 * FUNCTION: acpi_ex_decode_field_access 182 * 183 * PARAMETERS: obj_desc - Field object 184 * field_flags - Encoded fieldflags (contains access bits) 185 * return_byte_alignment - Where the byte alignment is returned 186 * 187 * RETURN: Field granularity (8, 16, 32 or 64) and 188 * byte_alignment (1, 2, 3, or 4) 189 * 190 * DESCRIPTION: Decode the access_type bits of a field definition. 191 * 192 ******************************************************************************/ 193 194 static u32 195 acpi_ex_decode_field_access(union acpi_operand_object *obj_desc, 196 u8 field_flags, u32 * return_byte_alignment) 197 { 198 u32 access; 199 u32 byte_alignment; 200 u32 bit_length; 201 202 ACPI_FUNCTION_TRACE(ex_decode_field_access); 203 204 access = (field_flags & AML_FIELD_ACCESS_TYPE_MASK); 205 206 switch (access) { 207 case AML_FIELD_ACCESS_ANY: 208 209 #ifdef ACPI_UNDER_DEVELOPMENT 210 byte_alignment = 211 acpi_ex_generate_access(obj_desc->common_field. 212 start_field_bit_offset, 213 obj_desc->common_field.bit_length, 214 0xFFFFFFFF 215 /* Temp until we pass region_length as parameter */ 216 ); 217 bit_length = byte_alignment * 8; 218 #endif 219 220 byte_alignment = 1; 221 bit_length = 8; 222 break; 223 224 case AML_FIELD_ACCESS_BYTE: 225 case AML_FIELD_ACCESS_BUFFER: /* ACPI 2.0 (SMBus Buffer) */ 226 227 byte_alignment = 1; 228 bit_length = 8; 229 break; 230 231 case AML_FIELD_ACCESS_WORD: 232 233 byte_alignment = 2; 234 bit_length = 16; 235 break; 236 237 case AML_FIELD_ACCESS_DWORD: 238 239 byte_alignment = 4; 240 bit_length = 32; 241 break; 242 243 case AML_FIELD_ACCESS_QWORD: /* ACPI 2.0 */ 244 245 byte_alignment = 8; 246 bit_length = 64; 247 break; 248 249 default: 250 251 /* Invalid field access type */ 252 253 ACPI_ERROR((AE_INFO, "Unknown field access type 0x%X", access)); 254 255 return_UINT32(0); 256 } 257 258 if (obj_desc->common.type == ACPI_TYPE_BUFFER_FIELD) { 259 /* 260 * buffer_field access can be on any byte boundary, so the 261 * byte_alignment is always 1 byte -- regardless of any byte_alignment 262 * implied by the field access type. 263 */ 264 byte_alignment = 1; 265 } 266 267 *return_byte_alignment = byte_alignment; 268 return_UINT32(bit_length); 269 } 270 271 /******************************************************************************* 272 * 273 * FUNCTION: acpi_ex_prep_common_field_object 274 * 275 * PARAMETERS: obj_desc - The field object 276 * field_flags - Access, lock_rule, and update_rule. 277 * The format of a field_flag is described 278 * in the ACPI specification 279 * field_attribute - Special attributes (not used) 280 * field_bit_position - Field start position 281 * field_bit_length - Field length in number of bits 282 * 283 * RETURN: Status 284 * 285 * DESCRIPTION: Initialize the areas of the field object that are common 286 * to the various types of fields. Note: This is very "sensitive" 287 * code because we are solving the general case for field 288 * alignment. 289 * 290 ******************************************************************************/ 291 292 acpi_status 293 acpi_ex_prep_common_field_object(union acpi_operand_object *obj_desc, 294 u8 field_flags, 295 u8 field_attribute, 296 u32 field_bit_position, u32 field_bit_length) 297 { 298 u32 access_bit_width; 299 u32 byte_alignment; 300 u32 nearest_byte_address; 301 302 ACPI_FUNCTION_TRACE(ex_prep_common_field_object); 303 304 /* 305 * Note: the structure being initialized is the 306 * ACPI_COMMON_FIELD_INFO; No structure fields outside of the common 307 * area are initialized by this procedure. 308 */ 309 obj_desc->common_field.field_flags = field_flags; 310 obj_desc->common_field.attribute = field_attribute; 311 obj_desc->common_field.bit_length = field_bit_length; 312 313 /* 314 * Decode the access type so we can compute offsets. The access type gives 315 * two pieces of information - the width of each field access and the 316 * necessary byte_alignment (address granularity) of the access. 317 * 318 * For any_acc, the access_bit_width is the largest width that is both 319 * necessary and possible in an attempt to access the whole field in one 320 * I/O operation. However, for any_acc, the byte_alignment is always one 321 * byte. 322 * 323 * For all Buffer Fields, the byte_alignment is always one byte. 324 * 325 * For all other access types (Byte, Word, Dword, Qword), the Bitwidth is 326 * the same (equivalent) as the byte_alignment. 327 */ 328 access_bit_width = 329 acpi_ex_decode_field_access(obj_desc, field_flags, &byte_alignment); 330 if (!access_bit_width) { 331 return_ACPI_STATUS(AE_AML_OPERAND_VALUE); 332 } 333 334 /* Setup width (access granularity) fields (values are: 1, 2, 4, 8) */ 335 336 obj_desc->common_field.access_byte_width = (u8) 337 ACPI_DIV_8(access_bit_width); 338 339 /* 340 * base_byte_offset is the address of the start of the field within the 341 * region. It is the byte address of the first *datum* (field-width data 342 * unit) of the field. (i.e., the first datum that contains at least the 343 * first *bit* of the field.) 344 * 345 * Note: byte_alignment is always either equal to the access_bit_width or 8 346 * (Byte access), and it defines the addressing granularity of the parent 347 * region or buffer. 348 */ 349 nearest_byte_address = 350 ACPI_ROUND_BITS_DOWN_TO_BYTES(field_bit_position); 351 obj_desc->common_field.base_byte_offset = (u32) 352 ACPI_ROUND_DOWN(nearest_byte_address, byte_alignment); 353 354 /* 355 * start_field_bit_offset is the offset of the first bit of the field within 356 * a field datum. 357 */ 358 obj_desc->common_field.start_field_bit_offset = (u8) 359 (field_bit_position - 360 ACPI_MUL_8(obj_desc->common_field.base_byte_offset)); 361 362 return_ACPI_STATUS(AE_OK); 363 } 364 365 /******************************************************************************* 366 * 367 * FUNCTION: acpi_ex_prep_field_value 368 * 369 * PARAMETERS: info - Contains all field creation info 370 * 371 * RETURN: Status 372 * 373 * DESCRIPTION: Construct an object of type union acpi_operand_object with a 374 * subtype of def_field and connect it to the parent Node. 375 * 376 ******************************************************************************/ 377 378 acpi_status acpi_ex_prep_field_value(struct acpi_create_field_info *info) 379 { 380 union acpi_operand_object *obj_desc; 381 union acpi_operand_object *second_desc = NULL; 382 acpi_status status; 383 u32 access_byte_width; 384 u32 type; 385 386 ACPI_FUNCTION_TRACE(ex_prep_field_value); 387 388 /* Parameter validation */ 389 390 if (info->field_type != ACPI_TYPE_LOCAL_INDEX_FIELD) { 391 if (!info->region_node) { 392 ACPI_ERROR((AE_INFO, "Null RegionNode")); 393 return_ACPI_STATUS(AE_AML_NO_OPERAND); 394 } 395 396 type = acpi_ns_get_type(info->region_node); 397 if (type != ACPI_TYPE_REGION) { 398 ACPI_ERROR((AE_INFO, 399 "Needed Region, found type 0x%X (%s)", type, 400 acpi_ut_get_type_name(type))); 401 402 return_ACPI_STATUS(AE_AML_OPERAND_TYPE); 403 } 404 } 405 406 /* Allocate a new field object */ 407 408 obj_desc = acpi_ut_create_internal_object(info->field_type); 409 if (!obj_desc) { 410 return_ACPI_STATUS(AE_NO_MEMORY); 411 } 412 413 /* Initialize areas of the object that are common to all fields */ 414 415 obj_desc->common_field.node = info->field_node; 416 status = acpi_ex_prep_common_field_object(obj_desc, 417 info->field_flags, 418 info->attribute, 419 info->field_bit_position, 420 info->field_bit_length); 421 if (ACPI_FAILURE(status)) { 422 acpi_ut_delete_object_desc(obj_desc); 423 return_ACPI_STATUS(status); 424 } 425 426 /* Initialize areas of the object that are specific to the field type */ 427 428 switch (info->field_type) { 429 case ACPI_TYPE_LOCAL_REGION_FIELD: 430 431 obj_desc->field.region_obj = 432 acpi_ns_get_attached_object(info->region_node); 433 434 /* Fields specific to generic_serial_bus fields */ 435 436 obj_desc->field.access_length = info->access_length; 437 438 if (info->connection_node) { 439 second_desc = info->connection_node->object; 440 if (second_desc == NULL) { 441 break; 442 } 443 if (!(second_desc->common.flags & AOPOBJ_DATA_VALID)) { 444 status = 445 acpi_ds_get_buffer_arguments(second_desc); 446 if (ACPI_FAILURE(status)) { 447 acpi_ut_delete_object_desc(obj_desc); 448 return_ACPI_STATUS(status); 449 } 450 } 451 452 obj_desc->field.resource_buffer = 453 second_desc->buffer.pointer; 454 obj_desc->field.resource_length = 455 (u16)second_desc->buffer.length; 456 } else if (info->resource_buffer) { 457 obj_desc->field.resource_buffer = info->resource_buffer; 458 obj_desc->field.resource_length = info->resource_length; 459 } 460 461 obj_desc->field.pin_number_index = info->pin_number_index; 462 463 /* Allow full data read from EC address space */ 464 465 if ((obj_desc->field.region_obj->region.space_id == 466 ACPI_ADR_SPACE_EC) 467 && (obj_desc->common_field.bit_length > 8)) { 468 access_byte_width = 469 ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field. 470 bit_length); 471 472 /* Maximum byte width supported is 255 */ 473 474 if (access_byte_width < 256) { 475 obj_desc->common_field.access_byte_width = 476 (u8)access_byte_width; 477 } 478 } 479 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, 480 "RegionField: BitOff %X, Off %X, Gran %X, Region %p\n", 481 obj_desc->field.start_field_bit_offset, 482 obj_desc->field.base_byte_offset, 483 obj_desc->field.access_byte_width, 484 obj_desc->field.region_obj)); 485 break; 486 487 case ACPI_TYPE_LOCAL_BANK_FIELD: 488 489 obj_desc->bank_field.value = info->bank_value; 490 obj_desc->bank_field.region_obj = 491 acpi_ns_get_attached_object(info->region_node); 492 obj_desc->bank_field.bank_obj = 493 acpi_ns_get_attached_object(info->register_node); 494 495 /* An additional reference for the attached objects */ 496 497 acpi_ut_add_reference(obj_desc->bank_field.region_obj); 498 acpi_ut_add_reference(obj_desc->bank_field.bank_obj); 499 500 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, 501 "Bank Field: BitOff %X, Off %X, Gran %X, Region %p, BankReg %p\n", 502 obj_desc->bank_field.start_field_bit_offset, 503 obj_desc->bank_field.base_byte_offset, 504 obj_desc->field.access_byte_width, 505 obj_desc->bank_field.region_obj, 506 obj_desc->bank_field.bank_obj)); 507 508 /* 509 * Remember location in AML stream of the field unit 510 * opcode and operands -- since the bank_value 511 * operands must be evaluated. 512 */ 513 second_desc = obj_desc->common.next_object; 514 second_desc->extra.aml_start = 515 ACPI_CAST_PTR(union acpi_parse_object, 516 info->data_register_node)->named.data; 517 second_desc->extra.aml_length = 518 ACPI_CAST_PTR(union acpi_parse_object, 519 info->data_register_node)->named.length; 520 521 break; 522 523 case ACPI_TYPE_LOCAL_INDEX_FIELD: 524 525 /* Get the Index and Data registers */ 526 527 obj_desc->index_field.index_obj = 528 acpi_ns_get_attached_object(info->register_node); 529 obj_desc->index_field.data_obj = 530 acpi_ns_get_attached_object(info->data_register_node); 531 532 if (!obj_desc->index_field.data_obj 533 || !obj_desc->index_field.index_obj) { 534 ACPI_ERROR((AE_INFO, 535 "Null Index Object during field prep")); 536 acpi_ut_delete_object_desc(obj_desc); 537 return_ACPI_STATUS(AE_AML_INTERNAL); 538 } 539 540 /* An additional reference for the attached objects */ 541 542 acpi_ut_add_reference(obj_desc->index_field.data_obj); 543 acpi_ut_add_reference(obj_desc->index_field.index_obj); 544 545 /* 546 * April 2006: Changed to match MS behavior 547 * 548 * The value written to the Index register is the byte offset of the 549 * target field in units of the granularity of the index_field 550 * 551 * Previously, the value was calculated as an index in terms of the 552 * width of the Data register, as below: 553 * 554 * obj_desc->index_field.Value = (u32) 555 * (Info->field_bit_position / ACPI_MUL_8 ( 556 * obj_desc->Field.access_byte_width)); 557 * 558 * February 2006: Tried value as a byte offset: 559 * obj_desc->index_field.Value = (u32) 560 * ACPI_DIV_8 (Info->field_bit_position); 561 */ 562 obj_desc->index_field.value = 563 (u32) ACPI_ROUND_DOWN(ACPI_DIV_8(info->field_bit_position), 564 obj_desc->index_field. 565 access_byte_width); 566 567 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, 568 "IndexField: BitOff %X, Off %X, Value %X, " 569 "Gran %X, Index %p, Data %p\n", 570 obj_desc->index_field.start_field_bit_offset, 571 obj_desc->index_field.base_byte_offset, 572 obj_desc->index_field.value, 573 obj_desc->field.access_byte_width, 574 obj_desc->index_field.index_obj, 575 obj_desc->index_field.data_obj)); 576 break; 577 578 default: 579 580 /* No other types should get here */ 581 582 break; 583 } 584 585 /* 586 * Store the constructed descriptor (obj_desc) into the parent Node, 587 * preserving the current type of that named_obj. 588 */ 589 status = 590 acpi_ns_attach_object(info->field_node, obj_desc, 591 acpi_ns_get_type(info->field_node)); 592 593 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, 594 "Set NamedObj %p [%4.4s], ObjDesc %p\n", 595 info->field_node, 596 acpi_ut_get_node_name(info->field_node), obj_desc)); 597 598 /* Remove local reference to the object */ 599 600 acpi_ut_remove_reference(obj_desc); 601 return_ACPI_STATUS(status); 602 } 603