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 }