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 - 2023, 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(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 | |
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 | 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 | |