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 - 2025, 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
28ACPI_MODULE_NAME("psloop")
29
30/* Local prototypes */
31static acpi_status
32acpi_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
49static acpi_status
50acpi_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(parser_state: &(walk_state->parser_state),
72 GET_CURRENT_ARG_TYPE(walk_state->
73 arg_types),
74 arg: op);
75 break;
76
77 case AML_INT_NAMEPATH_OP: /* AML_NAMESTRING_ARG */
78
79 status = acpi_ps_get_next_namepath(walk_state,
80 parser_state: &(walk_state->parser_state),
81 arg: 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 parser_state: &(walk_state->parser_state),
116 GET_CURRENT_ARG_TYPE
117 (walk_state->arg_types), return_arg: &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
221acpi_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 callback_status: status);
281 }
282
283 acpi_ps_pop_scope(parser_state, op: &op,
284 arg_list: &walk_state->arg_types,
285 arg_count: &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, new_op: &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: &op,
335 status);
336 if (ACPI_FAILURE(status)) {
337 return_ACPI_STATUS(status);
338 }
339 if (acpi_ns_opens_scope
340 (type: acpi_ps_get_opcode_info
341 (opcode: 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 (parser_state: &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: &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 remaining_args: walk_state->arg_types,
460 arg_count: walk_state->arg_count);
461 if (ACPI_FAILURE(status)) {
462 status =
463 acpi_ps_complete_op(walk_state, op: &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(opcode: 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, callback_status: 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: &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