xref: /openbmc/linux/drivers/acpi/acpica/psparse.c (revision 79f08d9e)
1 /******************************************************************************
2  *
3  * Module Name: psparse - Parser top level AML parse routines
4  *
5  *****************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2013, 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,
46  * like Perl, do. Parsing is done by hand rather than with a YACC
47  * generated parser to tightly constrain stack and dynamic memory
48  * usage. At the same time, parsing is kept flexible and the code
49  * fairly compact by parsing based on a list of AML opcode
50  * templates in aml_op_info[]
51  */
52 
53 #include <acpi/acpi.h>
54 #include "accommon.h"
55 #include "acparser.h"
56 #include "acdispat.h"
57 #include "amlcode.h"
58 #include "acinterp.h"
59 
60 #define _COMPONENT          ACPI_PARSER
61 ACPI_MODULE_NAME("psparse")
62 
63 /*******************************************************************************
64  *
65  * FUNCTION:    acpi_ps_get_opcode_size
66  *
67  * PARAMETERS:  opcode          - An AML opcode
68  *
69  * RETURN:      Size of the opcode, in bytes (1 or 2)
70  *
71  * DESCRIPTION: Get the size of the current opcode.
72  *
73  ******************************************************************************/
74 u32 acpi_ps_get_opcode_size(u32 opcode)
75 {
76 
77 	/* Extended (2-byte) opcode if > 255 */
78 
79 	if (opcode > 0x00FF) {
80 		return (2);
81 	}
82 
83 	/* Otherwise, just a single byte opcode */
84 
85 	return (1);
86 }
87 
88 /*******************************************************************************
89  *
90  * FUNCTION:    acpi_ps_peek_opcode
91  *
92  * PARAMETERS:  parser_state        - A parser state object
93  *
94  * RETURN:      Next AML opcode
95  *
96  * DESCRIPTION: Get next AML opcode (without incrementing AML pointer)
97  *
98  ******************************************************************************/
99 
100 u16 acpi_ps_peek_opcode(struct acpi_parse_state * parser_state)
101 {
102 	u8 *aml;
103 	u16 opcode;
104 
105 	aml = parser_state->aml;
106 	opcode = (u16) ACPI_GET8(aml);
107 
108 	if (opcode == AML_EXTENDED_OP_PREFIX) {
109 
110 		/* Extended opcode, get the second opcode byte */
111 
112 		aml++;
113 		opcode = (u16) ((opcode << 8) | ACPI_GET8(aml));
114 	}
115 
116 	return (opcode);
117 }
118 
119 /*******************************************************************************
120  *
121  * FUNCTION:    acpi_ps_complete_this_op
122  *
123  * PARAMETERS:  walk_state      - Current State
124  *              op              - Op to complete
125  *
126  * RETURN:      Status
127  *
128  * DESCRIPTION: Perform any cleanup at the completion of an Op.
129  *
130  ******************************************************************************/
131 
132 acpi_status
133 acpi_ps_complete_this_op(struct acpi_walk_state * walk_state,
134 			 union acpi_parse_object * op)
135 {
136 	union acpi_parse_object *prev;
137 	union acpi_parse_object *next;
138 	const struct acpi_opcode_info *parent_info;
139 	union acpi_parse_object *replacement_op = NULL;
140 	acpi_status status = AE_OK;
141 
142 	ACPI_FUNCTION_TRACE_PTR(ps_complete_this_op, op);
143 
144 	/* Check for null Op, can happen if AML code is corrupt */
145 
146 	if (!op) {
147 		return_ACPI_STATUS(AE_OK);	/* OK for now */
148 	}
149 
150 	/* Delete this op and the subtree below it if asked to */
151 
152 	if (((walk_state->parse_flags & ACPI_PARSE_TREE_MASK) !=
153 	     ACPI_PARSE_DELETE_TREE)
154 	    || (walk_state->op_info->class == AML_CLASS_ARGUMENT)) {
155 		return_ACPI_STATUS(AE_OK);
156 	}
157 
158 	/* Make sure that we only delete this subtree */
159 
160 	if (op->common.parent) {
161 		prev = op->common.parent->common.value.arg;
162 		if (!prev) {
163 
164 			/* Nothing more to do */
165 
166 			goto cleanup;
167 		}
168 
169 		/*
170 		 * Check if we need to replace the operator and its subtree
171 		 * with a return value op (placeholder op)
172 		 */
173 		parent_info =
174 		    acpi_ps_get_opcode_info(op->common.parent->common.
175 					    aml_opcode);
176 
177 		switch (parent_info->class) {
178 		case AML_CLASS_CONTROL:
179 
180 			break;
181 
182 		case AML_CLASS_CREATE:
183 			/*
184 			 * These opcodes contain term_arg operands. The current
185 			 * op must be replaced by a placeholder return op
186 			 */
187 			replacement_op =
188 			    acpi_ps_alloc_op(AML_INT_RETURN_VALUE_OP);
189 			if (!replacement_op) {
190 				status = AE_NO_MEMORY;
191 			}
192 			break;
193 
194 		case AML_CLASS_NAMED_OBJECT:
195 			/*
196 			 * These opcodes contain term_arg operands. The current
197 			 * op must be replaced by a placeholder return op
198 			 */
199 			if ((op->common.parent->common.aml_opcode ==
200 			     AML_REGION_OP)
201 			    || (op->common.parent->common.aml_opcode ==
202 				AML_DATA_REGION_OP)
203 			    || (op->common.parent->common.aml_opcode ==
204 				AML_BUFFER_OP)
205 			    || (op->common.parent->common.aml_opcode ==
206 				AML_PACKAGE_OP)
207 			    || (op->common.parent->common.aml_opcode ==
208 				AML_BANK_FIELD_OP)
209 			    || (op->common.parent->common.aml_opcode ==
210 				AML_VAR_PACKAGE_OP)) {
211 				replacement_op =
212 				    acpi_ps_alloc_op(AML_INT_RETURN_VALUE_OP);
213 				if (!replacement_op) {
214 					status = AE_NO_MEMORY;
215 				}
216 			} else
217 			    if ((op->common.parent->common.aml_opcode ==
218 				 AML_NAME_OP)
219 				&& (walk_state->pass_number <=
220 				    ACPI_IMODE_LOAD_PASS2)) {
221 				if ((op->common.aml_opcode == AML_BUFFER_OP)
222 				    || (op->common.aml_opcode == AML_PACKAGE_OP)
223 				    || (op->common.aml_opcode ==
224 					AML_VAR_PACKAGE_OP)) {
225 					replacement_op =
226 					    acpi_ps_alloc_op(op->common.
227 							     aml_opcode);
228 					if (!replacement_op) {
229 						status = AE_NO_MEMORY;
230 					} else {
231 						replacement_op->named.data =
232 						    op->named.data;
233 						replacement_op->named.length =
234 						    op->named.length;
235 					}
236 				}
237 			}
238 			break;
239 
240 		default:
241 
242 			replacement_op =
243 			    acpi_ps_alloc_op(AML_INT_RETURN_VALUE_OP);
244 			if (!replacement_op) {
245 				status = AE_NO_MEMORY;
246 			}
247 		}
248 
249 		/* We must unlink this op from the parent tree */
250 
251 		if (prev == op) {
252 
253 			/* This op is the first in the list */
254 
255 			if (replacement_op) {
256 				replacement_op->common.parent =
257 				    op->common.parent;
258 				replacement_op->common.value.arg = NULL;
259 				replacement_op->common.node = op->common.node;
260 				op->common.parent->common.value.arg =
261 				    replacement_op;
262 				replacement_op->common.next = op->common.next;
263 			} else {
264 				op->common.parent->common.value.arg =
265 				    op->common.next;
266 			}
267 		}
268 
269 		/* Search the parent list */
270 
271 		else
272 			while (prev) {
273 
274 				/* Traverse all siblings in the parent's argument list */
275 
276 				next = prev->common.next;
277 				if (next == op) {
278 					if (replacement_op) {
279 						replacement_op->common.parent =
280 						    op->common.parent;
281 						replacement_op->common.value.
282 						    arg = NULL;
283 						replacement_op->common.node =
284 						    op->common.node;
285 						prev->common.next =
286 						    replacement_op;
287 						replacement_op->common.next =
288 						    op->common.next;
289 						next = NULL;
290 					} else {
291 						prev->common.next =
292 						    op->common.next;
293 						next = NULL;
294 					}
295 				}
296 				prev = next;
297 			}
298 	}
299 
300 cleanup:
301 
302 	/* Now we can actually delete the subtree rooted at Op */
303 
304 	acpi_ps_delete_parse_tree(op);
305 	return_ACPI_STATUS(status);
306 }
307 
308 /*******************************************************************************
309  *
310  * FUNCTION:    acpi_ps_next_parse_state
311  *
312  * PARAMETERS:  walk_state          - Current state
313  *              op                  - Current parse op
314  *              callback_status     - Status from previous operation
315  *
316  * RETURN:      Status
317  *
318  * DESCRIPTION: Update the parser state based upon the return exception from
319  *              the parser callback.
320  *
321  ******************************************************************************/
322 
323 acpi_status
324 acpi_ps_next_parse_state(struct acpi_walk_state *walk_state,
325 			 union acpi_parse_object *op,
326 			 acpi_status callback_status)
327 {
328 	struct acpi_parse_state *parser_state = &walk_state->parser_state;
329 	acpi_status status = AE_CTRL_PENDING;
330 
331 	ACPI_FUNCTION_TRACE_PTR(ps_next_parse_state, op);
332 
333 	switch (callback_status) {
334 	case AE_CTRL_TERMINATE:
335 		/*
336 		 * A control method was terminated via a RETURN statement.
337 		 * The walk of this method is complete.
338 		 */
339 		parser_state->aml = parser_state->aml_end;
340 		status = AE_CTRL_TERMINATE;
341 		break;
342 
343 	case AE_CTRL_BREAK:
344 
345 		parser_state->aml = walk_state->aml_last_while;
346 		walk_state->control_state->common.value = FALSE;
347 		status = AE_CTRL_BREAK;
348 		break;
349 
350 	case AE_CTRL_CONTINUE:
351 
352 		parser_state->aml = walk_state->aml_last_while;
353 		status = AE_CTRL_CONTINUE;
354 		break;
355 
356 	case AE_CTRL_PENDING:
357 
358 		parser_state->aml = walk_state->aml_last_while;
359 		break;
360 
361 #if 0
362 	case AE_CTRL_SKIP:
363 
364 		parser_state->aml = parser_state->scope->parse_scope.pkg_end;
365 		status = AE_OK;
366 		break;
367 #endif
368 
369 	case AE_CTRL_TRUE:
370 		/*
371 		 * Predicate of an IF was true, and we are at the matching ELSE.
372 		 * Just close out this package
373 		 */
374 		parser_state->aml = acpi_ps_get_next_package_end(parser_state);
375 		status = AE_CTRL_PENDING;
376 		break;
377 
378 	case AE_CTRL_FALSE:
379 		/*
380 		 * Either an IF/WHILE Predicate was false or we encountered a BREAK
381 		 * opcode. In both cases, we do not execute the rest of the
382 		 * package;  We simply close out the parent (finishing the walk of
383 		 * this branch of the tree) and continue execution at the parent
384 		 * level.
385 		 */
386 		parser_state->aml = parser_state->scope->parse_scope.pkg_end;
387 
388 		/* In the case of a BREAK, just force a predicate (if any) to FALSE */
389 
390 		walk_state->control_state->common.value = FALSE;
391 		status = AE_CTRL_END;
392 		break;
393 
394 	case AE_CTRL_TRANSFER:
395 
396 		/* A method call (invocation) -- transfer control */
397 
398 		status = AE_CTRL_TRANSFER;
399 		walk_state->prev_op = op;
400 		walk_state->method_call_op = op;
401 		walk_state->method_call_node =
402 		    (op->common.value.arg)->common.node;
403 
404 		/* Will return value (if any) be used by the caller? */
405 
406 		walk_state->return_used =
407 		    acpi_ds_is_result_used(op, walk_state);
408 		break;
409 
410 	default:
411 
412 		status = callback_status;
413 		if ((callback_status & AE_CODE_MASK) == AE_CODE_CONTROL) {
414 			status = AE_OK;
415 		}
416 		break;
417 	}
418 
419 	return_ACPI_STATUS(status);
420 }
421 
422 /*******************************************************************************
423  *
424  * FUNCTION:    acpi_ps_parse_aml
425  *
426  * PARAMETERS:  walk_state      - Current state
427  *
428  *
429  * RETURN:      Status
430  *
431  * DESCRIPTION: Parse raw AML and return a tree of ops
432  *
433  ******************************************************************************/
434 
435 acpi_status acpi_ps_parse_aml(struct acpi_walk_state *walk_state)
436 {
437 	acpi_status status;
438 	struct acpi_thread_state *thread;
439 	struct acpi_thread_state *prev_walk_list = acpi_gbl_current_walk_list;
440 	struct acpi_walk_state *previous_walk_state;
441 
442 	ACPI_FUNCTION_TRACE(ps_parse_aml);
443 
444 	ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
445 			  "Entered with WalkState=%p Aml=%p size=%X\n",
446 			  walk_state, walk_state->parser_state.aml,
447 			  walk_state->parser_state.aml_size));
448 
449 	if (!walk_state->parser_state.aml) {
450 		return_ACPI_STATUS(AE_NULL_OBJECT);
451 	}
452 
453 	/* Create and initialize a new thread state */
454 
455 	thread = acpi_ut_create_thread_state();
456 	if (!thread) {
457 		if (walk_state->method_desc) {
458 
459 			/* Executing a control method - additional cleanup */
460 
461 			acpi_ds_terminate_control_method(walk_state->
462 							 method_desc,
463 							 walk_state);
464 		}
465 
466 		acpi_ds_delete_walk_state(walk_state);
467 		return_ACPI_STATUS(AE_NO_MEMORY);
468 	}
469 
470 	walk_state->thread = thread;
471 
472 	/*
473 	 * If executing a method, the starting sync_level is this method's
474 	 * sync_level
475 	 */
476 	if (walk_state->method_desc) {
477 		walk_state->thread->current_sync_level =
478 		    walk_state->method_desc->method.sync_level;
479 	}
480 
481 	acpi_ds_push_walk_state(walk_state, thread);
482 
483 	/*
484 	 * This global allows the AML debugger to get a handle to the currently
485 	 * executing control method.
486 	 */
487 	acpi_gbl_current_walk_list = thread;
488 
489 	/*
490 	 * Execute the walk loop as long as there is a valid Walk State. This
491 	 * handles nested control method invocations without recursion.
492 	 */
493 	ACPI_DEBUG_PRINT((ACPI_DB_PARSE, "State=%p\n", walk_state));
494 
495 	status = AE_OK;
496 	while (walk_state) {
497 		if (ACPI_SUCCESS(status)) {
498 			/*
499 			 * The parse_loop executes AML until the method terminates
500 			 * or calls another method.
501 			 */
502 			status = acpi_ps_parse_loop(walk_state);
503 		}
504 
505 		ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
506 				  "Completed one call to walk loop, %s State=%p\n",
507 				  acpi_format_exception(status), walk_state));
508 
509 		if (status == AE_CTRL_TRANSFER) {
510 			/*
511 			 * A method call was detected.
512 			 * Transfer control to the called control method
513 			 */
514 			status =
515 			    acpi_ds_call_control_method(thread, walk_state,
516 							NULL);
517 			if (ACPI_FAILURE(status)) {
518 				status =
519 				    acpi_ds_method_error(status, walk_state);
520 			}
521 
522 			/*
523 			 * If the transfer to the new method method call worked, a new walk
524 			 * state was created -- get it
525 			 */
526 			walk_state = acpi_ds_get_current_walk_state(thread);
527 			continue;
528 		} else if (status == AE_CTRL_TERMINATE) {
529 			status = AE_OK;
530 		} else if ((status != AE_OK) && (walk_state->method_desc)) {
531 
532 			/* Either the method parse or actual execution failed */
533 
534 			ACPI_ERROR_METHOD("Method parse/execution failed",
535 					  walk_state->method_node, NULL,
536 					  status);
537 
538 			/* Check for possible multi-thread reentrancy problem */
539 
540 			if ((status == AE_ALREADY_EXISTS) &&
541 			    (!(walk_state->method_desc->method.
542 			       info_flags & ACPI_METHOD_SERIALIZED))) {
543 				/*
544 				 * Method is not serialized and tried to create an object
545 				 * twice. The probable cause is that the method cannot
546 				 * handle reentrancy. Mark as "pending serialized" now, and
547 				 * then mark "serialized" when the last thread exits.
548 				 */
549 				walk_state->method_desc->method.info_flags |=
550 				    ACPI_METHOD_SERIALIZED_PENDING;
551 			}
552 		}
553 
554 		/* We are done with this walk, move on to the parent if any */
555 
556 		walk_state = acpi_ds_pop_walk_state(thread);
557 
558 		/* Reset the current scope to the beginning of scope stack */
559 
560 		acpi_ds_scope_stack_clear(walk_state);
561 
562 		/*
563 		 * If we just returned from the execution of a control method or if we
564 		 * encountered an error during the method parse phase, there's lots of
565 		 * cleanup to do
566 		 */
567 		if (((walk_state->parse_flags & ACPI_PARSE_MODE_MASK) ==
568 		     ACPI_PARSE_EXECUTE) || (ACPI_FAILURE(status))) {
569 			acpi_ds_terminate_control_method(walk_state->
570 							 method_desc,
571 							 walk_state);
572 		}
573 
574 		/* Delete this walk state and all linked control states */
575 
576 		acpi_ps_cleanup_scope(&walk_state->parser_state);
577 		previous_walk_state = walk_state;
578 
579 		ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
580 				  "ReturnValue=%p, ImplicitValue=%p State=%p\n",
581 				  walk_state->return_desc,
582 				  walk_state->implicit_return_obj, walk_state));
583 
584 		/* Check if we have restarted a preempted walk */
585 
586 		walk_state = acpi_ds_get_current_walk_state(thread);
587 		if (walk_state) {
588 			if (ACPI_SUCCESS(status)) {
589 				/*
590 				 * There is another walk state, restart it.
591 				 * If the method return value is not used by the parent,
592 				 * The object is deleted
593 				 */
594 				if (!previous_walk_state->return_desc) {
595 					/*
596 					 * In slack mode execution, if there is no return value
597 					 * we should implicitly return zero (0) as a default value.
598 					 */
599 					if (acpi_gbl_enable_interpreter_slack &&
600 					    !previous_walk_state->
601 					    implicit_return_obj) {
602 						previous_walk_state->
603 						    implicit_return_obj =
604 						    acpi_ut_create_integer_object
605 						    ((u64) 0);
606 						if (!previous_walk_state->
607 						    implicit_return_obj) {
608 							return_ACPI_STATUS
609 							    (AE_NO_MEMORY);
610 						}
611 					}
612 
613 					/* Restart the calling control method */
614 
615 					status =
616 					    acpi_ds_restart_control_method
617 					    (walk_state,
618 					     previous_walk_state->
619 					     implicit_return_obj);
620 				} else {
621 					/*
622 					 * We have a valid return value, delete any implicit
623 					 * return value.
624 					 */
625 					acpi_ds_clear_implicit_return
626 					    (previous_walk_state);
627 
628 					status =
629 					    acpi_ds_restart_control_method
630 					    (walk_state,
631 					     previous_walk_state->return_desc);
632 				}
633 				if (ACPI_SUCCESS(status)) {
634 					walk_state->walk_type |=
635 					    ACPI_WALK_METHOD_RESTART;
636 				}
637 			} else {
638 				/* On error, delete any return object or implicit return */
639 
640 				acpi_ut_remove_reference(previous_walk_state->
641 							 return_desc);
642 				acpi_ds_clear_implicit_return
643 				    (previous_walk_state);
644 			}
645 		}
646 
647 		/*
648 		 * Just completed a 1st-level method, save the final internal return
649 		 * value (if any)
650 		 */
651 		else if (previous_walk_state->caller_return_desc) {
652 			if (previous_walk_state->implicit_return_obj) {
653 				*(previous_walk_state->caller_return_desc) =
654 				    previous_walk_state->implicit_return_obj;
655 			} else {
656 				/* NULL if no return value */
657 
658 				*(previous_walk_state->caller_return_desc) =
659 				    previous_walk_state->return_desc;
660 			}
661 		} else {
662 			if (previous_walk_state->return_desc) {
663 
664 				/* Caller doesn't want it, must delete it */
665 
666 				acpi_ut_remove_reference(previous_walk_state->
667 							 return_desc);
668 			}
669 			if (previous_walk_state->implicit_return_obj) {
670 
671 				/* Caller doesn't want it, must delete it */
672 
673 				acpi_ut_remove_reference(previous_walk_state->
674 							 implicit_return_obj);
675 			}
676 		}
677 
678 		acpi_ds_delete_walk_state(previous_walk_state);
679 	}
680 
681 	/* Normal exit */
682 
683 	acpi_ex_release_all_mutexes(thread);
684 	acpi_ut_delete_generic_state(ACPI_CAST_PTR
685 				     (union acpi_generic_state, thread));
686 	acpi_gbl_current_walk_list = prev_walk_list;
687 	return_ACPI_STATUS(status);
688 }
689