1/******************************************************************************
2 *
3 * Module Name: psparse - Parser top level AML parse routines
4 *
5 *****************************************************************************/
6
7/*
8 * Copyright (C) 2000 - 2015, 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
61ACPI_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 ******************************************************************************/
74u32 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
100u16 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
132acpi_status
133acpi_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
300cleanup:
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
323acpi_status
324acpi_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
435acpi_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