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 - 2019, 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 && ((status & AE_CODE_MASK) != 268 AE_CODE_CONTROL)) { 269 if (status == AE_AML_NO_RETURN_VALUE) { 270 ACPI_EXCEPTION((AE_INFO, status, 271 "Invoked method did not return a value")); 272 } 273 274 ACPI_EXCEPTION((AE_INFO, status, 275 "GetPredicate Failed")); 276 return_ACPI_STATUS(status); 277 } 278 279 status = 280 acpi_ps_next_parse_state(walk_state, op, 281 status); 282 } 283 284 acpi_ps_pop_scope(parser_state, &op, 285 &walk_state->arg_types, 286 &walk_state->arg_count); 287 ACPI_DEBUG_PRINT((ACPI_DB_PARSE, 288 "Popped scope, Op=%p\n", op)); 289 } else if (walk_state->prev_op) { 290 291 /* We were in the middle of an op */ 292 293 op = walk_state->prev_op; 294 walk_state->arg_types = walk_state->prev_arg_types; 295 } 296 } 297 #endif 298 299 /* Iterative parsing loop, while there is more AML to process: */ 300 301 while ((parser_state->aml < parser_state->aml_end) || (op)) { 302 ASL_CV_CAPTURE_COMMENTS(walk_state); 303 304 aml_op_start = parser_state->aml; 305 if (!op) { 306 status = 307 acpi_ps_create_op(walk_state, aml_op_start, &op); 308 if (ACPI_FAILURE(status)) { 309 /* 310 * ACPI_PARSE_MODULE_LEVEL means that we are loading a table by 311 * executing it as a control method. However, if we encounter 312 * an error while loading the table, we need to keep trying to 313 * load the table rather than aborting the table load. Set the 314 * status to AE_OK to proceed with the table load. 315 */ 316 if ((walk_state-> 317 parse_flags & ACPI_PARSE_MODULE_LEVEL) 318 && ((status == AE_ALREADY_EXISTS) 319 || (status == AE_NOT_FOUND))) { 320 status = AE_OK; 321 } 322 if (status == AE_CTRL_PARSE_CONTINUE) { 323 continue; 324 } 325 326 if (status == AE_CTRL_PARSE_PENDING) { 327 status = AE_OK; 328 } 329 330 if (status == AE_CTRL_TERMINATE) { 331 return_ACPI_STATUS(status); 332 } 333 334 status = 335 acpi_ps_complete_op(walk_state, &op, 336 status); 337 if (ACPI_FAILURE(status)) { 338 return_ACPI_STATUS(status); 339 } 340 if (acpi_ns_opens_scope 341 (acpi_ps_get_opcode_info 342 (walk_state->opcode)->object_type)) { 343 /* 344 * If the scope/device op fails to parse, skip the body of 345 * the scope op because the parse failure indicates that 346 * the device may not exist. 347 */ 348 ACPI_INFO(("Skipping parse of AML opcode: %s (0x%4.4X)", acpi_ps_get_opcode_name(walk_state->opcode), walk_state->opcode)); 349 350 /* 351 * Determine the opcode length before skipping the opcode. 352 * An opcode can be 1 byte or 2 bytes in length. 353 */ 354 opcode_length = 1; 355 if ((walk_state->opcode & 0xFF00) == 356 AML_EXTENDED_OPCODE) { 357 opcode_length = 2; 358 } 359 walk_state->parser_state.aml = 360 walk_state->aml + opcode_length; 361 362 walk_state->parser_state.aml = 363 acpi_ps_get_next_package_end 364 (&walk_state->parser_state); 365 walk_state->aml = 366 walk_state->parser_state.aml; 367 } 368 369 continue; 370 } 371 372 acpi_ex_start_trace_opcode(op, walk_state); 373 } 374 375 /* 376 * Start arg_count at zero because we don't know if there are 377 * any args yet 378 */ 379 walk_state->arg_count = 0; 380 381 switch (op->common.aml_opcode) { 382 case AML_BYTE_OP: 383 case AML_WORD_OP: 384 case AML_DWORD_OP: 385 case AML_QWORD_OP: 386 387 break; 388 389 default: 390 391 ASL_CV_CAPTURE_COMMENTS(walk_state); 392 break; 393 } 394 395 /* Are there any arguments that must be processed? */ 396 397 if (walk_state->arg_types) { 398 399 /* Get arguments */ 400 401 status = 402 acpi_ps_get_arguments(walk_state, aml_op_start, op); 403 if (ACPI_FAILURE(status)) { 404 status = 405 acpi_ps_complete_op(walk_state, &op, 406 status); 407 if (ACPI_FAILURE(status)) { 408 return_ACPI_STATUS(status); 409 } 410 if ((walk_state->control_state) && 411 ((walk_state->control_state->control. 412 opcode == AML_IF_OP) 413 || (walk_state->control_state->control. 414 opcode == AML_WHILE_OP))) { 415 /* 416 * If the if/while op fails to parse, we will skip parsing 417 * the body of the op. 418 */ 419 parser_state->aml = 420 walk_state->control_state->control. 421 aml_predicate_start + 1; 422 parser_state->aml = 423 acpi_ps_get_next_package_end 424 (parser_state); 425 walk_state->aml = parser_state->aml; 426 427 ACPI_ERROR((AE_INFO, 428 "Skipping While/If block")); 429 if (*walk_state->aml == AML_ELSE_OP) { 430 ACPI_ERROR((AE_INFO, 431 "Skipping Else block")); 432 walk_state->parser_state.aml = 433 walk_state->aml + 1; 434 walk_state->parser_state.aml = 435 acpi_ps_get_next_package_end 436 (parser_state); 437 walk_state->aml = 438 parser_state->aml; 439 } 440 ACPI_FREE(acpi_ut_pop_generic_state 441 (&walk_state->control_state)); 442 } 443 op = NULL; 444 continue; 445 } 446 } 447 448 /* Check for arguments that need to be processed */ 449 450 ACPI_DEBUG_PRINT((ACPI_DB_PARSE, 451 "Parseloop: argument count: %8.8X\n", 452 walk_state->arg_count)); 453 454 if (walk_state->arg_count) { 455 /* 456 * There are arguments (complex ones), push Op and 457 * prepare for argument 458 */ 459 status = acpi_ps_push_scope(parser_state, op, 460 walk_state->arg_types, 461 walk_state->arg_count); 462 if (ACPI_FAILURE(status)) { 463 status = 464 acpi_ps_complete_op(walk_state, &op, 465 status); 466 if (ACPI_FAILURE(status)) { 467 return_ACPI_STATUS(status); 468 } 469 470 continue; 471 } 472 473 op = NULL; 474 continue; 475 } 476 477 /* 478 * All arguments have been processed -- Op is complete, 479 * prepare for next 480 */ 481 walk_state->op_info = 482 acpi_ps_get_opcode_info(op->common.aml_opcode); 483 if (walk_state->op_info->flags & AML_NAMED) { 484 if (op->common.aml_opcode == AML_REGION_OP || 485 op->common.aml_opcode == AML_DATA_REGION_OP) { 486 /* 487 * Skip parsing of control method or opregion body, 488 * because we don't have enough info in the first pass 489 * to parse them correctly. 490 * 491 * Completed parsing an op_region declaration, we now 492 * know the length. 493 */ 494 op->named.length = 495 (u32) (parser_state->aml - op->named.data); 496 } 497 } 498 499 if (walk_state->op_info->flags & AML_CREATE) { 500 /* 501 * Backup to beginning of create_XXXfield declaration (1 for 502 * Opcode) 503 * 504 * body_length is unknown until we parse the body 505 */ 506 op->named.length = 507 (u32) (parser_state->aml - op->named.data); 508 } 509 510 if (op->common.aml_opcode == AML_BANK_FIELD_OP) { 511 /* 512 * Backup to beginning of bank_field declaration 513 * 514 * body_length is unknown until we parse the body 515 */ 516 op->named.length = 517 (u32) (parser_state->aml - op->named.data); 518 } 519 520 /* This op complete, notify the dispatcher */ 521 522 if (walk_state->ascending_callback != NULL) { 523 walk_state->op = op; 524 walk_state->opcode = op->common.aml_opcode; 525 526 status = walk_state->ascending_callback(walk_state); 527 status = 528 acpi_ps_next_parse_state(walk_state, op, status); 529 if (status == AE_CTRL_PENDING) { 530 status = AE_OK; 531 } else 532 if ((walk_state-> 533 parse_flags & ACPI_PARSE_MODULE_LEVEL) 534 && (ACPI_AML_EXCEPTION(status) 535 || status == AE_ALREADY_EXISTS 536 || status == AE_NOT_FOUND)) { 537 /* 538 * ACPI_PARSE_MODULE_LEVEL flag means that we 539 * are currently loading a table by executing 540 * it as a control method. However, if we 541 * encounter an error while loading the table, 542 * we need to keep trying to load the table 543 * rather than aborting the table load (setting 544 * the status to AE_OK continues the table 545 * load). If we get a failure at this point, it 546 * means that the dispatcher got an error while 547 * trying to execute the Op. 548 */ 549 status = AE_OK; 550 } 551 } 552 553 status = acpi_ps_complete_op(walk_state, &op, status); 554 if (ACPI_FAILURE(status)) { 555 return_ACPI_STATUS(status); 556 } 557 558 } /* while parser_state->Aml */ 559 560 status = acpi_ps_complete_final_op(walk_state, op, status); 561 return_ACPI_STATUS(status); 562 } 563