xref: /openbmc/linux/drivers/acpi/acpica/psloop.c (revision a06c488d)
1 /******************************************************************************
2  *
3  * Module Name: psloop - Main AML parse loop
4  *
5  *****************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2016, Intel Corp.
9  * All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions, and the following disclaimer,
16  *    without modification.
17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
18  *    substantially similar to the "NO WARRANTY" disclaimer below
19  *    ("Disclaimer") and any redistribution must be conditioned upon
20  *    including a substantially similar Disclaimer requirement for further
21  *    binary redistribution.
22  * 3. Neither the names of the above-listed copyright holders nor the names
23  *    of any contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * Alternatively, this software may be distributed under the terms of the
27  * GNU General Public License ("GPL") version 2 as published by the Free
28  * Software Foundation.
29  *
30  * NO WARRANTY
31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
41  * POSSIBILITY OF SUCH DAMAGES.
42  */
43 
44 /*
45  * Parse the AML and build an operation tree as most interpreters, (such as
46  * Perl) do. Parsing is done by hand rather than with a YACC generated parser
47  * to tightly constrain stack and dynamic memory usage. Parsing is kept
48  * flexible and the code fairly compact by parsing based on a list of AML
49  * opcode templates in aml_op_info[].
50  */
51 
52 #include <acpi/acpi.h>
53 #include "accommon.h"
54 #include "acinterp.h"
55 #include "acparser.h"
56 #include "acdispat.h"
57 #include "amlcode.h"
58 
59 #define _COMPONENT          ACPI_PARSER
60 ACPI_MODULE_NAME("psloop")
61 
62 /* Local prototypes */
63 static acpi_status
64 acpi_ps_get_arguments(struct acpi_walk_state *walk_state,
65 		      u8 * aml_op_start, union acpi_parse_object *op);
66 
67 static void
68 acpi_ps_link_module_code(union acpi_parse_object *parent_op,
69 			 u8 *aml_start, u32 aml_length, acpi_owner_id owner_id);
70 
71 /*******************************************************************************
72  *
73  * FUNCTION:    acpi_ps_get_arguments
74  *
75  * PARAMETERS:  walk_state          - Current state
76  *              aml_op_start        - Op start in AML
77  *              op                  - Current Op
78  *
79  * RETURN:      Status
80  *
81  * DESCRIPTION: Get arguments for passed Op.
82  *
83  ******************************************************************************/
84 
85 static acpi_status
86 acpi_ps_get_arguments(struct acpi_walk_state *walk_state,
87 		      u8 * aml_op_start, union acpi_parse_object *op)
88 {
89 	acpi_status status = AE_OK;
90 	union acpi_parse_object *arg = NULL;
91 	const struct acpi_opcode_info *op_info;
92 
93 	ACPI_FUNCTION_TRACE_PTR(ps_get_arguments, walk_state);
94 
95 	switch (op->common.aml_opcode) {
96 	case AML_BYTE_OP:	/* AML_BYTEDATA_ARG */
97 	case AML_WORD_OP:	/* AML_WORDDATA_ARG */
98 	case AML_DWORD_OP:	/* AML_DWORDATA_ARG */
99 	case AML_QWORD_OP:	/* AML_QWORDATA_ARG */
100 	case AML_STRING_OP:	/* AML_ASCIICHARLIST_ARG */
101 
102 		/* Fill in constant or string argument directly */
103 
104 		acpi_ps_get_next_simple_arg(&(walk_state->parser_state),
105 					    GET_CURRENT_ARG_TYPE(walk_state->
106 								 arg_types),
107 					    op);
108 		break;
109 
110 	case AML_INT_NAMEPATH_OP:	/* AML_NAMESTRING_ARG */
111 
112 		status = acpi_ps_get_next_namepath(walk_state,
113 						   &(walk_state->parser_state),
114 						   op,
115 						   ACPI_POSSIBLE_METHOD_CALL);
116 		if (ACPI_FAILURE(status)) {
117 			return_ACPI_STATUS(status);
118 		}
119 
120 		walk_state->arg_types = 0;
121 		break;
122 
123 	default:
124 		/*
125 		 * Op is not a constant or string, append each argument to the Op
126 		 */
127 		while (GET_CURRENT_ARG_TYPE(walk_state->arg_types) &&
128 		       !walk_state->arg_count) {
129 			walk_state->aml = walk_state->parser_state.aml;
130 
131 			status =
132 			    acpi_ps_get_next_arg(walk_state,
133 						 &(walk_state->parser_state),
134 						 GET_CURRENT_ARG_TYPE
135 						 (walk_state->arg_types), &arg);
136 			if (ACPI_FAILURE(status)) {
137 				return_ACPI_STATUS(status);
138 			}
139 
140 			if (arg) {
141 				acpi_ps_append_arg(op, arg);
142 			}
143 
144 			INCREMENT_ARG_LIST(walk_state->arg_types);
145 		}
146 
147 		/*
148 		 * Handle executable code at "module-level". This refers to
149 		 * executable opcodes that appear outside of any control method.
150 		 */
151 		if ((walk_state->pass_number <= ACPI_IMODE_LOAD_PASS2) &&
152 		    ((walk_state->parse_flags & ACPI_PARSE_DISASSEMBLE) == 0)) {
153 			/*
154 			 * We want to skip If/Else/While constructs during Pass1 because we
155 			 * want to actually conditionally execute the code during Pass2.
156 			 *
157 			 * Except for disassembly, where we always want to walk the
158 			 * If/Else/While packages
159 			 */
160 			switch (op->common.aml_opcode) {
161 			case AML_IF_OP:
162 			case AML_ELSE_OP:
163 			case AML_WHILE_OP:
164 				/*
165 				 * Currently supported module-level opcodes are:
166 				 * IF/ELSE/WHILE. These appear to be the most common,
167 				 * and easiest to support since they open an AML
168 				 * package.
169 				 */
170 				if (walk_state->pass_number ==
171 				    ACPI_IMODE_LOAD_PASS1) {
172 					acpi_ps_link_module_code(op->common.
173 								 parent,
174 								 aml_op_start,
175 								 (u32)
176 								 (walk_state->
177 								 parser_state.
178 								 pkg_end -
179 								 aml_op_start),
180 								 walk_state->
181 								 owner_id);
182 				}
183 
184 				ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
185 						  "Pass1: Skipping an If/Else/While body\n"));
186 
187 				/* Skip body of if/else/while in pass 1 */
188 
189 				walk_state->parser_state.aml =
190 				    walk_state->parser_state.pkg_end;
191 				walk_state->arg_count = 0;
192 				break;
193 
194 			default:
195 				/*
196 				 * Check for an unsupported executable opcode at module
197 				 * level. We must be in PASS1, the parent must be a SCOPE,
198 				 * The opcode class must be EXECUTE, and the opcode must
199 				 * not be an argument to another opcode.
200 				 */
201 				if ((walk_state->pass_number ==
202 				     ACPI_IMODE_LOAD_PASS1)
203 				    && (op->common.parent->common.aml_opcode ==
204 					AML_SCOPE_OP)) {
205 					op_info =
206 					    acpi_ps_get_opcode_info(op->common.
207 								    aml_opcode);
208 					if ((op_info->class ==
209 					     AML_CLASS_EXECUTE) && (!arg)) {
210 						ACPI_WARNING((AE_INFO,
211 							      "Unsupported module-level executable opcode "
212 							      "0x%.2X at table offset 0x%.4X",
213 							      op->common.
214 							      aml_opcode,
215 							      (u32)
216 							      (ACPI_PTR_DIFF
217 							       (aml_op_start,
218 								walk_state->
219 								parser_state.
220 								aml_start) +
221 							       sizeof(struct
222 								      acpi_table_header))));
223 					}
224 				}
225 				break;
226 			}
227 		}
228 
229 		/* Special processing for certain opcodes */
230 
231 		switch (op->common.aml_opcode) {
232 		case AML_METHOD_OP:
233 			/*
234 			 * Skip parsing of control method because we don't have enough
235 			 * info in the first pass to parse it correctly.
236 			 *
237 			 * Save the length and address of the body
238 			 */
239 			op->named.data = walk_state->parser_state.aml;
240 			op->named.length = (u32)
241 			    (walk_state->parser_state.pkg_end -
242 			     walk_state->parser_state.aml);
243 
244 			/* Skip body of method */
245 
246 			walk_state->parser_state.aml =
247 			    walk_state->parser_state.pkg_end;
248 			walk_state->arg_count = 0;
249 			break;
250 
251 		case AML_BUFFER_OP:
252 		case AML_PACKAGE_OP:
253 		case AML_VAR_PACKAGE_OP:
254 
255 			if ((op->common.parent) &&
256 			    (op->common.parent->common.aml_opcode ==
257 			     AML_NAME_OP)
258 			    && (walk_state->pass_number <=
259 				ACPI_IMODE_LOAD_PASS2)) {
260 				/*
261 				 * Skip parsing of Buffers and Packages because we don't have
262 				 * enough info in the first pass to parse them correctly.
263 				 */
264 				op->named.data = aml_op_start;
265 				op->named.length = (u32)
266 				    (walk_state->parser_state.pkg_end -
267 				     aml_op_start);
268 
269 				/* Skip body */
270 
271 				walk_state->parser_state.aml =
272 				    walk_state->parser_state.pkg_end;
273 				walk_state->arg_count = 0;
274 			}
275 			break;
276 
277 		case AML_WHILE_OP:
278 
279 			if (walk_state->control_state) {
280 				walk_state->control_state->control.package_end =
281 				    walk_state->parser_state.pkg_end;
282 			}
283 			break;
284 
285 		default:
286 
287 			/* No action for all other opcodes */
288 
289 			break;
290 		}
291 
292 		break;
293 	}
294 
295 	return_ACPI_STATUS(AE_OK);
296 }
297 
298 /*******************************************************************************
299  *
300  * FUNCTION:    acpi_ps_link_module_code
301  *
302  * PARAMETERS:  parent_op           - Parent parser op
303  *              aml_start           - Pointer to the AML
304  *              aml_length          - Length of executable AML
305  *              owner_id            - owner_id of module level code
306  *
307  * RETURN:      None.
308  *
309  * DESCRIPTION: Wrap the module-level code with a method object and link the
310  *              object to the global list. Note, the mutex field of the method
311  *              object is used to link multiple module-level code objects.
312  *
313  ******************************************************************************/
314 
315 static void
316 acpi_ps_link_module_code(union acpi_parse_object *parent_op,
317 			 u8 *aml_start, u32 aml_length, acpi_owner_id owner_id)
318 {
319 	union acpi_operand_object *prev;
320 	union acpi_operand_object *next;
321 	union acpi_operand_object *method_obj;
322 	struct acpi_namespace_node *parent_node;
323 
324 	ACPI_FUNCTION_TRACE(ps_link_module_code);
325 
326 	/* Get the tail of the list */
327 
328 	prev = next = acpi_gbl_module_code_list;
329 	while (next) {
330 		prev = next;
331 		next = next->method.mutex;
332 	}
333 
334 	/*
335 	 * Insert the module level code into the list. Merge it if it is
336 	 * adjacent to the previous element.
337 	 */
338 	if (!prev ||
339 	    ((prev->method.aml_start + prev->method.aml_length) != aml_start)) {
340 
341 		/* Create, initialize, and link a new temporary method object */
342 
343 		method_obj = acpi_ut_create_internal_object(ACPI_TYPE_METHOD);
344 		if (!method_obj) {
345 			return_VOID;
346 		}
347 
348 		ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
349 				  "Create/Link new code block: %p\n",
350 				  method_obj));
351 
352 		if (parent_op->common.node) {
353 			parent_node = parent_op->common.node;
354 		} else {
355 			parent_node = acpi_gbl_root_node;
356 		}
357 
358 		method_obj->method.aml_start = aml_start;
359 		method_obj->method.aml_length = aml_length;
360 		method_obj->method.owner_id = owner_id;
361 		method_obj->method.info_flags |= ACPI_METHOD_MODULE_LEVEL;
362 
363 		/*
364 		 * Save the parent node in next_object. This is cheating, but we
365 		 * don't want to expand the method object.
366 		 */
367 		method_obj->method.next_object =
368 		    ACPI_CAST_PTR(union acpi_operand_object, parent_node);
369 
370 		if (!prev) {
371 			acpi_gbl_module_code_list = method_obj;
372 		} else {
373 			prev->method.mutex = method_obj;
374 		}
375 	} else {
376 		ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
377 				  "Appending to existing code block: %p\n",
378 				  prev));
379 
380 		prev->method.aml_length += aml_length;
381 	}
382 
383 	return_VOID;
384 }
385 
386 /*******************************************************************************
387  *
388  * FUNCTION:    acpi_ps_parse_loop
389  *
390  * PARAMETERS:  walk_state          - Current state
391  *
392  * RETURN:      Status
393  *
394  * DESCRIPTION: Parse AML (pointed to by the current parser state) and return
395  *              a tree of ops.
396  *
397  ******************************************************************************/
398 
399 acpi_status acpi_ps_parse_loop(struct acpi_walk_state *walk_state)
400 {
401 	acpi_status status = AE_OK;
402 	union acpi_parse_object *op = NULL;	/* current op */
403 	struct acpi_parse_state *parser_state;
404 	u8 *aml_op_start = NULL;
405 
406 	ACPI_FUNCTION_TRACE_PTR(ps_parse_loop, walk_state);
407 
408 	if (walk_state->descending_callback == NULL) {
409 		return_ACPI_STATUS(AE_BAD_PARAMETER);
410 	}
411 
412 	parser_state = &walk_state->parser_state;
413 	walk_state->arg_types = 0;
414 
415 #if (!defined (ACPI_NO_METHOD_EXECUTION) && !defined (ACPI_CONSTANT_EVAL_ONLY))
416 
417 	if (walk_state->walk_type & ACPI_WALK_METHOD_RESTART) {
418 
419 		/* We are restarting a preempted control method */
420 
421 		if (acpi_ps_has_completed_scope(parser_state)) {
422 			/*
423 			 * We must check if a predicate to an IF or WHILE statement
424 			 * was just completed
425 			 */
426 			if ((parser_state->scope->parse_scope.op) &&
427 			    ((parser_state->scope->parse_scope.op->common.
428 			      aml_opcode == AML_IF_OP)
429 			     || (parser_state->scope->parse_scope.op->common.
430 				 aml_opcode == AML_WHILE_OP))
431 			    && (walk_state->control_state)
432 			    && (walk_state->control_state->common.state ==
433 				ACPI_CONTROL_PREDICATE_EXECUTING)) {
434 				/*
435 				 * A predicate was just completed, get the value of the
436 				 * predicate and branch based on that value
437 				 */
438 				walk_state->op = NULL;
439 				status =
440 				    acpi_ds_get_predicate_value(walk_state,
441 								ACPI_TO_POINTER
442 								(TRUE));
443 				if (ACPI_FAILURE(status)
444 				    && ((status & AE_CODE_MASK) !=
445 					AE_CODE_CONTROL)) {
446 					if (status == AE_AML_NO_RETURN_VALUE) {
447 						ACPI_EXCEPTION((AE_INFO, status,
448 								"Invoked method did not return a value"));
449 					}
450 
451 					ACPI_EXCEPTION((AE_INFO, status,
452 							"GetPredicate Failed"));
453 					return_ACPI_STATUS(status);
454 				}
455 
456 				status =
457 				    acpi_ps_next_parse_state(walk_state, op,
458 							     status);
459 			}
460 
461 			acpi_ps_pop_scope(parser_state, &op,
462 					  &walk_state->arg_types,
463 					  &walk_state->arg_count);
464 			ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
465 					  "Popped scope, Op=%p\n", op));
466 		} else if (walk_state->prev_op) {
467 
468 			/* We were in the middle of an op */
469 
470 			op = walk_state->prev_op;
471 			walk_state->arg_types = walk_state->prev_arg_types;
472 		}
473 	}
474 #endif
475 
476 	/* Iterative parsing loop, while there is more AML to process: */
477 
478 	while ((parser_state->aml < parser_state->aml_end) || (op)) {
479 		aml_op_start = parser_state->aml;
480 		if (!op) {
481 			status =
482 			    acpi_ps_create_op(walk_state, aml_op_start, &op);
483 			if (ACPI_FAILURE(status)) {
484 				if (status == AE_CTRL_PARSE_CONTINUE) {
485 					continue;
486 				}
487 
488 				if (status == AE_CTRL_PARSE_PENDING) {
489 					status = AE_OK;
490 				}
491 
492 				if (status == AE_CTRL_TERMINATE) {
493 					return_ACPI_STATUS(status);
494 				}
495 
496 				status =
497 				    acpi_ps_complete_op(walk_state, &op,
498 							status);
499 				if (ACPI_FAILURE(status)) {
500 					return_ACPI_STATUS(status);
501 				}
502 
503 				continue;
504 			}
505 
506 			acpi_ex_start_trace_opcode(op, walk_state);
507 		}
508 
509 		/*
510 		 * Start arg_count at zero because we don't know if there are
511 		 * any args yet
512 		 */
513 		walk_state->arg_count = 0;
514 
515 		/* Are there any arguments that must be processed? */
516 
517 		if (walk_state->arg_types) {
518 
519 			/* Get arguments */
520 
521 			status =
522 			    acpi_ps_get_arguments(walk_state, aml_op_start, op);
523 			if (ACPI_FAILURE(status)) {
524 				status =
525 				    acpi_ps_complete_op(walk_state, &op,
526 							status);
527 				if (ACPI_FAILURE(status)) {
528 					return_ACPI_STATUS(status);
529 				}
530 
531 				continue;
532 			}
533 		}
534 
535 		/* Check for arguments that need to be processed */
536 
537 		if (walk_state->arg_count) {
538 			/*
539 			 * There are arguments (complex ones), push Op and
540 			 * prepare for argument
541 			 */
542 			status = acpi_ps_push_scope(parser_state, op,
543 						    walk_state->arg_types,
544 						    walk_state->arg_count);
545 			if (ACPI_FAILURE(status)) {
546 				status =
547 				    acpi_ps_complete_op(walk_state, &op,
548 							status);
549 				if (ACPI_FAILURE(status)) {
550 					return_ACPI_STATUS(status);
551 				}
552 
553 				continue;
554 			}
555 
556 			op = NULL;
557 			continue;
558 		}
559 
560 		/*
561 		 * All arguments have been processed -- Op is complete,
562 		 * prepare for next
563 		 */
564 		walk_state->op_info =
565 		    acpi_ps_get_opcode_info(op->common.aml_opcode);
566 		if (walk_state->op_info->flags & AML_NAMED) {
567 			if (op->common.aml_opcode == AML_REGION_OP ||
568 			    op->common.aml_opcode == AML_DATA_REGION_OP) {
569 				/*
570 				 * Skip parsing of control method or opregion body,
571 				 * because we don't have enough info in the first pass
572 				 * to parse them correctly.
573 				 *
574 				 * Completed parsing an op_region declaration, we now
575 				 * know the length.
576 				 */
577 				op->named.length =
578 				    (u32) (parser_state->aml - op->named.data);
579 			}
580 		}
581 
582 		if (walk_state->op_info->flags & AML_CREATE) {
583 			/*
584 			 * Backup to beginning of create_XXXfield declaration (1 for
585 			 * Opcode)
586 			 *
587 			 * body_length is unknown until we parse the body
588 			 */
589 			op->named.length =
590 			    (u32) (parser_state->aml - op->named.data);
591 		}
592 
593 		if (op->common.aml_opcode == AML_BANK_FIELD_OP) {
594 			/*
595 			 * Backup to beginning of bank_field declaration
596 			 *
597 			 * body_length is unknown until we parse the body
598 			 */
599 			op->named.length =
600 			    (u32) (parser_state->aml - op->named.data);
601 		}
602 
603 		/* This op complete, notify the dispatcher */
604 
605 		if (walk_state->ascending_callback != NULL) {
606 			walk_state->op = op;
607 			walk_state->opcode = op->common.aml_opcode;
608 
609 			status = walk_state->ascending_callback(walk_state);
610 			status =
611 			    acpi_ps_next_parse_state(walk_state, op, status);
612 			if (status == AE_CTRL_PENDING) {
613 				status = AE_OK;
614 			}
615 		}
616 
617 		status = acpi_ps_complete_op(walk_state, &op, status);
618 		if (ACPI_FAILURE(status)) {
619 			return_ACPI_STATUS(status);
620 		}
621 
622 	}			/* while parser_state->Aml */
623 
624 	status = acpi_ps_complete_final_op(walk_state, op, status);
625 	return_ACPI_STATUS(status);
626 }
627