xref: /linux/drivers/acpi/acpica/psloop.c (revision 24168c5e6dfbdd5b414f048f47f75d64533296ca) 
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(&(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