1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0 2 /****************************************************************************** 3 * 4 * Module Name: psloop - Main AML parse loop 5 * 6 * Copyright (C) 2000 - 2021, Intel Corp. 7 * 8 *****************************************************************************/ 9 10 /* 11 * Parse the AML and build an operation tree as most interpreters, (such as 12 * Perl) do. Parsing is done by hand rather than with a YACC generated parser 13 * to tightly constrain stack and dynamic memory usage. Parsing is kept 14 * flexible and the code fairly compact by parsing based on a list of AML 15 * opcode templates in aml_op_info[]. 16 */ 17 18 #include <acpi/acpi.h> 19 #include "accommon.h" 20 #include "acinterp.h" 21 #include "acparser.h" 22 #include "acdispat.h" 23 #include "amlcode.h" 24 #include "acconvert.h" 25 #include "acnamesp.h" 26 27 #define _COMPONENT ACPI_PARSER 28 ACPI_MODULE_NAME("psloop") 29 30 /* Local prototypes */ 31 static acpi_status 32 acpi_ps_get_arguments(struct acpi_walk_state *walk_state, 33 u8 * aml_op_start, union acpi_parse_object *op); 34 35 /******************************************************************************* 36 * 37 * FUNCTION: acpi_ps_get_arguments 38 * 39 * PARAMETERS: walk_state - Current state 40 * aml_op_start - Op start in AML 41 * op - Current Op 42 * 43 * RETURN: Status 44 * 45 * DESCRIPTION: Get arguments for passed Op. 46 * 47 ******************************************************************************/ 48 49 static acpi_status 50 acpi_ps_get_arguments(struct acpi_walk_state *walk_state, 51 u8 * aml_op_start, union acpi_parse_object *op) 52 { 53 acpi_status status = AE_OK; 54 union acpi_parse_object *arg = NULL; 55 56 ACPI_FUNCTION_TRACE_PTR(ps_get_arguments, walk_state); 57 58 ACPI_DEBUG_PRINT((ACPI_DB_PARSE, 59 "Get arguments for opcode [%s]\n", 60 op->common.aml_op_name)); 61 62 switch (op->common.aml_opcode) { 63 case AML_BYTE_OP: /* AML_BYTEDATA_ARG */ 64 case AML_WORD_OP: /* AML_WORDDATA_ARG */ 65 case AML_DWORD_OP: /* AML_DWORDATA_ARG */ 66 case AML_QWORD_OP: /* AML_QWORDATA_ARG */ 67 case AML_STRING_OP: /* AML_ASCIICHARLIST_ARG */ 68 69 /* Fill in constant or string argument directly */ 70 71 acpi_ps_get_next_simple_arg(&(walk_state->parser_state), 72 GET_CURRENT_ARG_TYPE(walk_state-> 73 arg_types), 74 op); 75 break; 76 77 case AML_INT_NAMEPATH_OP: /* AML_NAMESTRING_ARG */ 78 79 status = acpi_ps_get_next_namepath(walk_state, 80 &(walk_state->parser_state), 81 op, 82 ACPI_POSSIBLE_METHOD_CALL); 83 if (ACPI_FAILURE(status)) { 84 return_ACPI_STATUS(status); 85 } 86 87 walk_state->arg_types = 0; 88 break; 89 90 default: 91 /* 92 * Op is not a constant or string, append each argument to the Op 93 */ 94 while (GET_CURRENT_ARG_TYPE(walk_state->arg_types) && 95 !walk_state->arg_count) { 96 walk_state->aml = walk_state->parser_state.aml; 97 98 switch (op->common.aml_opcode) { 99 case AML_METHOD_OP: 100 case AML_BUFFER_OP: 101 case AML_PACKAGE_OP: 102 case AML_VARIABLE_PACKAGE_OP: 103 case AML_WHILE_OP: 104 105 break; 106 107 default: 108 109 ASL_CV_CAPTURE_COMMENTS(walk_state); 110 break; 111 } 112 113 status = 114 acpi_ps_get_next_arg(walk_state, 115 &(walk_state->parser_state), 116 GET_CURRENT_ARG_TYPE 117 (walk_state->arg_types), &arg); 118 if (ACPI_FAILURE(status)) { 119 return_ACPI_STATUS(status); 120 } 121 122 if (arg) { 123 acpi_ps_append_arg(op, arg); 124 } 125 126 INCREMENT_ARG_LIST(walk_state->arg_types); 127 } 128 129 ACPI_DEBUG_PRINT((ACPI_DB_PARSE, 130 "Final argument count: %8.8X pass %u\n", 131 walk_state->arg_count, 132 walk_state->pass_number)); 133 134 /* Special processing for certain opcodes */ 135 136 switch (op->common.aml_opcode) { 137 case AML_METHOD_OP: 138 /* 139 * Skip parsing of control method because we don't have enough 140 * info in the first pass to parse it correctly. 141 * 142 * Save the length and address of the body 143 */ 144 op->named.data = walk_state->parser_state.aml; 145 op->named.length = (u32) 146 (walk_state->parser_state.pkg_end - 147 walk_state->parser_state.aml); 148 149 /* Skip body of method */ 150 151 walk_state->parser_state.aml = 152 walk_state->parser_state.pkg_end; 153 walk_state->arg_count = 0; 154 break; 155 156 case AML_BUFFER_OP: 157 case AML_PACKAGE_OP: 158 case AML_VARIABLE_PACKAGE_OP: 159 160 if ((op->common.parent) && 161 (op->common.parent->common.aml_opcode == 162 AML_NAME_OP) 163 && (walk_state->pass_number <= 164 ACPI_IMODE_LOAD_PASS2)) { 165 ACPI_DEBUG_PRINT((ACPI_DB_PARSE, 166 "Setup Package/Buffer: Pass %u, AML Ptr: %p\n", 167 walk_state->pass_number, 168 aml_op_start)); 169 170 /* 171 * Skip parsing of Buffers and Packages because we don't have 172 * enough info in the first pass to parse them correctly. 173 */ 174 op->named.data = aml_op_start; 175 op->named.length = (u32) 176 (walk_state->parser_state.pkg_end - 177 aml_op_start); 178 179 /* Skip body */ 180 181 walk_state->parser_state.aml = 182 walk_state->parser_state.pkg_end; 183 walk_state->arg_count = 0; 184 } 185 break; 186 187 case AML_WHILE_OP: 188 189 if (walk_state->control_state) { 190 walk_state->control_state->control.package_end = 191 walk_state->parser_state.pkg_end; 192 } 193 break; 194 195 default: 196 197 /* No action for all other opcodes */ 198 199 break; 200 } 201 202 break; 203 } 204 205 return_ACPI_STATUS(AE_OK); 206 } 207 208 /******************************************************************************* 209 * 210 * FUNCTION: acpi_ps_parse_loop 211 * 212 * PARAMETERS: walk_state - Current state 213 * 214 * RETURN: Status 215 * 216 * DESCRIPTION: Parse AML (pointed to by the current parser state) and return 217 * a tree of ops. 218 * 219 ******************************************************************************/ 220 221 acpi_status acpi_ps_parse_loop(struct acpi_walk_state *walk_state) 222 { 223 acpi_status status = AE_OK; 224 union acpi_parse_object *op = NULL; /* current op */ 225 struct acpi_parse_state *parser_state; 226 u8 *aml_op_start = NULL; 227 u8 opcode_length; 228 229 ACPI_FUNCTION_TRACE_PTR(ps_parse_loop, walk_state); 230 231 if (walk_state->descending_callback == NULL) { 232 return_ACPI_STATUS(AE_BAD_PARAMETER); 233 } 234 235 parser_state = &walk_state->parser_state; 236 walk_state->arg_types = 0; 237 238 #ifndef ACPI_CONSTANT_EVAL_ONLY 239 240 if (walk_state->walk_type & ACPI_WALK_METHOD_RESTART) { 241 242 /* We are restarting a preempted control method */ 243 244 if (acpi_ps_has_completed_scope(parser_state)) { 245 /* 246 * We must check if a predicate to an IF or WHILE statement 247 * was just completed 248 */ 249 if ((parser_state->scope->parse_scope.op) && 250 ((parser_state->scope->parse_scope.op->common. 251 aml_opcode == AML_IF_OP) 252 || (parser_state->scope->parse_scope.op->common. 253 aml_opcode == AML_WHILE_OP)) 254 && (walk_state->control_state) 255 && (walk_state->control_state->common.state == 256 ACPI_CONTROL_PREDICATE_EXECUTING)) { 257 /* 258 * A predicate was just completed, get the value of the 259 * predicate and branch based on that value 260 */ 261 walk_state->op = NULL; 262 status = 263 acpi_ds_get_predicate_value(walk_state, 264 ACPI_TO_POINTER 265 (TRUE)); 266 if (ACPI_FAILURE(status) 267 && !ACPI_CNTL_EXCEPTION(status)) { 268 if (status == AE_AML_NO_RETURN_VALUE) { 269 ACPI_EXCEPTION((AE_INFO, status, 270 "Invoked method did not return a value")); 271 } 272 273 ACPI_EXCEPTION((AE_INFO, status, 274 "GetPredicate Failed")); 275 return_ACPI_STATUS(status); 276 } 277 278 status = 279 acpi_ps_next_parse_state(walk_state, op, 280 status); 281 } 282 283 acpi_ps_pop_scope(parser_state, &op, 284 &walk_state->arg_types, 285 &walk_state->arg_count); 286 ACPI_DEBUG_PRINT((ACPI_DB_PARSE, 287 "Popped scope, Op=%p\n", op)); 288 } else if (walk_state->prev_op) { 289 290 /* We were in the middle of an op */ 291 292 op = walk_state->prev_op; 293 walk_state->arg_types = walk_state->prev_arg_types; 294 } 295 } 296 #endif 297 298 /* Iterative parsing loop, while there is more AML to process: */ 299 300 while ((parser_state->aml < parser_state->aml_end) || (op)) { 301 ASL_CV_CAPTURE_COMMENTS(walk_state); 302 303 aml_op_start = parser_state->aml; 304 if (!op) { 305 status = 306 acpi_ps_create_op(walk_state, aml_op_start, &op); 307 if (ACPI_FAILURE(status)) { 308 /* 309 * ACPI_PARSE_MODULE_LEVEL means that we are loading a table by 310 * executing it as a control method. However, if we encounter 311 * an error while loading the table, we need to keep trying to 312 * load the table rather than aborting the table load. Set the 313 * status to AE_OK to proceed with the table load. 314 */ 315 if ((walk_state-> 316 parse_flags & ACPI_PARSE_MODULE_LEVEL) 317 && ((status == AE_ALREADY_EXISTS) 318 || (status == AE_NOT_FOUND))) { 319 status = AE_OK; 320 } 321 if (status == AE_CTRL_PARSE_CONTINUE) { 322 continue; 323 } 324 325 if (status == AE_CTRL_PARSE_PENDING) { 326 status = AE_OK; 327 } 328 329 if (status == AE_CTRL_TERMINATE) { 330 return_ACPI_STATUS(status); 331 } 332 333 status = 334 acpi_ps_complete_op(walk_state, &op, 335 status); 336 if (ACPI_FAILURE(status)) { 337 return_ACPI_STATUS(status); 338 } 339 if (acpi_ns_opens_scope 340 (acpi_ps_get_opcode_info 341 (walk_state->opcode)->object_type)) { 342 /* 343 * If the scope/device op fails to parse, skip the body of 344 * the scope op because the parse failure indicates that 345 * the device may not exist. 346 */ 347 ACPI_INFO(("Skipping parse of AML opcode: %s (0x%4.4X)", acpi_ps_get_opcode_name(walk_state->opcode), walk_state->opcode)); 348 349 /* 350 * Determine the opcode length before skipping the opcode. 351 * An opcode can be 1 byte or 2 bytes in length. 352 */ 353 opcode_length = 1; 354 if ((walk_state->opcode & 0xFF00) == 355 AML_EXTENDED_OPCODE) { 356 opcode_length = 2; 357 } 358 walk_state->parser_state.aml = 359 walk_state->aml + opcode_length; 360 361 walk_state->parser_state.aml = 362 acpi_ps_get_next_package_end 363 (&walk_state->parser_state); 364 walk_state->aml = 365 walk_state->parser_state.aml; 366 } 367 368 continue; 369 } 370 371 acpi_ex_start_trace_opcode(op, walk_state); 372 } 373 374 /* 375 * Start arg_count at zero because we don't know if there are 376 * any args yet 377 */ 378 walk_state->arg_count = 0; 379 380 switch (op->common.aml_opcode) { 381 case AML_BYTE_OP: 382 case AML_WORD_OP: 383 case AML_DWORD_OP: 384 case AML_QWORD_OP: 385 386 break; 387 388 default: 389 390 ASL_CV_CAPTURE_COMMENTS(walk_state); 391 break; 392 } 393 394 /* Are there any arguments that must be processed? */ 395 396 if (walk_state->arg_types) { 397 398 /* Get arguments */ 399 400 status = 401 acpi_ps_get_arguments(walk_state, aml_op_start, op); 402 if (ACPI_FAILURE(status)) { 403 status = 404 acpi_ps_complete_op(walk_state, &op, 405 status); 406 if (ACPI_FAILURE(status)) { 407 return_ACPI_STATUS(status); 408 } 409 if ((walk_state->control_state) && 410 ((walk_state->control_state->control. 411 opcode == AML_IF_OP) 412 || (walk_state->control_state->control. 413 opcode == AML_WHILE_OP))) { 414 /* 415 * If the if/while op fails to parse, we will skip parsing 416 * the body of the op. 417 */ 418 parser_state->aml = 419 walk_state->control_state->control. 420 aml_predicate_start + 1; 421 parser_state->aml = 422 acpi_ps_get_next_package_end 423 (parser_state); 424 walk_state->aml = parser_state->aml; 425 426 ACPI_ERROR((AE_INFO, 427 "Skipping While/If block")); 428 if (*walk_state->aml == AML_ELSE_OP) { 429 ACPI_ERROR((AE_INFO, 430 "Skipping Else block")); 431 walk_state->parser_state.aml = 432 walk_state->aml + 1; 433 walk_state->parser_state.aml = 434 acpi_ps_get_next_package_end 435 (parser_state); 436 walk_state->aml = 437 parser_state->aml; 438 } 439 ACPI_FREE(acpi_ut_pop_generic_state 440 (&walk_state->control_state)); 441 } 442 op = NULL; 443 continue; 444 } 445 } 446 447 /* Check for arguments that need to be processed */ 448 449 ACPI_DEBUG_PRINT((ACPI_DB_PARSE, 450 "Parseloop: argument count: %8.8X\n", 451 walk_state->arg_count)); 452 453 if (walk_state->arg_count) { 454 /* 455 * There are arguments (complex ones), push Op and 456 * prepare for argument 457 */ 458 status = acpi_ps_push_scope(parser_state, op, 459 walk_state->arg_types, 460 walk_state->arg_count); 461 if (ACPI_FAILURE(status)) { 462 status = 463 acpi_ps_complete_op(walk_state, &op, 464 status); 465 if (ACPI_FAILURE(status)) { 466 return_ACPI_STATUS(status); 467 } 468 469 continue; 470 } 471 472 op = NULL; 473 continue; 474 } 475 476 /* 477 * All arguments have been processed -- Op is complete, 478 * prepare for next 479 */ 480 walk_state->op_info = 481 acpi_ps_get_opcode_info(op->common.aml_opcode); 482 if (walk_state->op_info->flags & AML_NAMED) { 483 if (op->common.aml_opcode == AML_REGION_OP || 484 op->common.aml_opcode == AML_DATA_REGION_OP) { 485 /* 486 * Skip parsing of control method or opregion body, 487 * because we don't have enough info in the first pass 488 * to parse them correctly. 489 * 490 * Completed parsing an op_region declaration, we now 491 * know the length. 492 */ 493 op->named.length = 494 (u32) (parser_state->aml - op->named.data); 495 } 496 } 497 498 if (walk_state->op_info->flags & AML_CREATE) { 499 /* 500 * Backup to beginning of create_XXXfield declaration (1 for 501 * Opcode) 502 * 503 * body_length is unknown until we parse the body 504 */ 505 op->named.length = 506 (u32) (parser_state->aml - op->named.data); 507 } 508 509 if (op->common.aml_opcode == AML_BANK_FIELD_OP) { 510 /* 511 * Backup to beginning of bank_field declaration 512 * 513 * body_length is unknown until we parse the body 514 */ 515 op->named.length = 516 (u32) (parser_state->aml - op->named.data); 517 } 518 519 /* This op complete, notify the dispatcher */ 520 521 if (walk_state->ascending_callback != NULL) { 522 walk_state->op = op; 523 walk_state->opcode = op->common.aml_opcode; 524 525 status = walk_state->ascending_callback(walk_state); 526 status = 527 acpi_ps_next_parse_state(walk_state, op, status); 528 if (status == AE_CTRL_PENDING) { 529 status = AE_OK; 530 } else 531 if ((walk_state-> 532 parse_flags & ACPI_PARSE_MODULE_LEVEL) 533 && (ACPI_AML_EXCEPTION(status) 534 || status == AE_ALREADY_EXISTS 535 || status == AE_NOT_FOUND)) { 536 /* 537 * ACPI_PARSE_MODULE_LEVEL flag means that we 538 * are currently loading a table by executing 539 * it as a control method. However, if we 540 * encounter an error while loading the table, 541 * we need to keep trying to load the table 542 * rather than aborting the table load (setting 543 * the status to AE_OK continues the table 544 * load). If we get a failure at this point, it 545 * means that the dispatcher got an error while 546 * trying to execute the Op. 547 */ 548 status = AE_OK; 549 } 550 } 551 552 status = acpi_ps_complete_op(walk_state, &op, status); 553 if (ACPI_FAILURE(status)) { 554 return_ACPI_STATUS(status); 555 } 556 557 } /* while parser_state->Aml */ 558 559 status = acpi_ps_complete_final_op(walk_state, op, status); 560 return_ACPI_STATUS(status); 561 } 562