1/******************************************************************************
2 *
3 * Module Name: psloop - Main AML parse loop
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, (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
60ACPI_MODULE_NAME("psloop")
61
62/* Local prototypes */
63static acpi_status
64acpi_ps_get_arguments(struct acpi_walk_state *walk_state,
65		      u8 * aml_op_start, union acpi_parse_object *op);
66
67static void
68acpi_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
85static acpi_status
86acpi_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 =
113		    acpi_ps_get_next_namepath(walk_state,
114					      &(walk_state->parser_state), op,
115					      1);
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
315static void
316acpi_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
399acpi_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