1/******************************************************************************
2 *
3 * Module Name: psloop - Main AML parse loop
4 *
5 *****************************************************************************/
6
7/*
8 * Copyright (C) 2000 - 2014, 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 "acparser.h"
55#include "acdispat.h"
56#include "amlcode.h"
57
58#define _COMPONENT          ACPI_PARSER
59ACPI_MODULE_NAME("psloop")
60
61/* Local prototypes */
62static acpi_status
63acpi_ps_get_arguments(struct acpi_walk_state *walk_state,
64		      u8 * aml_op_start, union acpi_parse_object *op);
65
66static void
67acpi_ps_link_module_code(union acpi_parse_object *parent_op,
68			 u8 *aml_start, u32 aml_length, acpi_owner_id owner_id);
69
70/*******************************************************************************
71 *
72 * FUNCTION:    acpi_ps_get_arguments
73 *
74 * PARAMETERS:  walk_state          - Current state
75 *              aml_op_start        - Op start in AML
76 *              op                  - Current Op
77 *
78 * RETURN:      Status
79 *
80 * DESCRIPTION: Get arguments for passed Op.
81 *
82 ******************************************************************************/
83
84static acpi_status
85acpi_ps_get_arguments(struct acpi_walk_state *walk_state,
86		      u8 * aml_op_start, union acpi_parse_object *op)
87{
88	acpi_status status = AE_OK;
89	union acpi_parse_object *arg = NULL;
90	const struct acpi_opcode_info *op_info;
91
92	ACPI_FUNCTION_TRACE_PTR(ps_get_arguments, walk_state);
93
94	switch (op->common.aml_opcode) {
95	case AML_BYTE_OP:	/* AML_BYTEDATA_ARG */
96	case AML_WORD_OP:	/* AML_WORDDATA_ARG */
97	case AML_DWORD_OP:	/* AML_DWORDATA_ARG */
98	case AML_QWORD_OP:	/* AML_QWORDATA_ARG */
99	case AML_STRING_OP:	/* AML_ASCIICHARLIST_ARG */
100
101		/* Fill in constant or string argument directly */
102
103		acpi_ps_get_next_simple_arg(&(walk_state->parser_state),
104					    GET_CURRENT_ARG_TYPE(walk_state->
105								 arg_types),
106					    op);
107		break;
108
109	case AML_INT_NAMEPATH_OP:	/* AML_NAMESTRING_ARG */
110
111		status =
112		    acpi_ps_get_next_namepath(walk_state,
113					      &(walk_state->parser_state), op,
114					      1);
115		if (ACPI_FAILURE(status)) {
116			return_ACPI_STATUS(status);
117		}
118
119		walk_state->arg_types = 0;
120		break;
121
122	default:
123		/*
124		 * Op is not a constant or string, append each argument to the Op
125		 */
126		while (GET_CURRENT_ARG_TYPE(walk_state->arg_types)
127		       && !walk_state->arg_count) {
128			walk_state->aml_offset =
129			    (u32) ACPI_PTR_DIFF(walk_state->parser_state.aml,
130						walk_state->parser_state.
131						aml_start);
132
133			status =
134			    acpi_ps_get_next_arg(walk_state,
135						 &(walk_state->parser_state),
136						 GET_CURRENT_ARG_TYPE
137						 (walk_state->arg_types), &arg);
138			if (ACPI_FAILURE(status)) {
139				return_ACPI_STATUS(status);
140			}
141
142			if (arg) {
143				arg->common.aml_offset = walk_state->aml_offset;
144				acpi_ps_append_arg(op, arg);
145			}
146
147			INCREMENT_ARG_LIST(walk_state->arg_types);
148		}
149
150		/*
151		 * Handle executable code at "module-level". This refers to
152		 * executable opcodes that appear outside of any control method.
153		 */
154		if ((walk_state->pass_number <= ACPI_IMODE_LOAD_PASS2) &&
155		    ((walk_state->parse_flags & ACPI_PARSE_DISASSEMBLE) == 0)) {
156			/*
157			 * We want to skip If/Else/While constructs during Pass1 because we
158			 * want to actually conditionally execute the code during Pass2.
159			 *
160			 * Except for disassembly, where we always want to walk the
161			 * If/Else/While packages
162			 */
163			switch (op->common.aml_opcode) {
164			case AML_IF_OP:
165			case AML_ELSE_OP:
166			case AML_WHILE_OP:
167				/*
168				 * Currently supported module-level opcodes are:
169				 * IF/ELSE/WHILE. These appear to be the most common,
170				 * and easiest to support since they open an AML
171				 * package.
172				 */
173				if (walk_state->pass_number ==
174				    ACPI_IMODE_LOAD_PASS1) {
175					acpi_ps_link_module_code(op->common.
176								 parent,
177								 aml_op_start,
178								 (u32)
179								 (walk_state->
180								 parser_state.
181								 pkg_end -
182								 aml_op_start),
183								 walk_state->
184								 owner_id);
185				}
186
187				ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
188						  "Pass1: Skipping an If/Else/While body\n"));
189
190				/* Skip body of if/else/while in pass 1 */
191
192				walk_state->parser_state.aml =
193				    walk_state->parser_state.pkg_end;
194				walk_state->arg_count = 0;
195				break;
196
197			default:
198				/*
199				 * Check for an unsupported executable opcode at module
200				 * level. We must be in PASS1, the parent must be a SCOPE,
201				 * The opcode class must be EXECUTE, and the opcode must
202				 * not be an argument to another opcode.
203				 */
204				if ((walk_state->pass_number ==
205				     ACPI_IMODE_LOAD_PASS1)
206				    && (op->common.parent->common.aml_opcode ==
207					AML_SCOPE_OP)) {
208					op_info =
209					    acpi_ps_get_opcode_info(op->common.
210								    aml_opcode);
211					if ((op_info->class ==
212					     AML_CLASS_EXECUTE) && (!arg)) {
213						ACPI_WARNING((AE_INFO,
214							      "Unsupported module-level executable opcode "
215							      "0x%.2X at table offset 0x%.4X",
216							      op->common.
217							      aml_opcode,
218							      (u32)
219							      (ACPI_PTR_DIFF
220							       (aml_op_start,
221								walk_state->
222								parser_state.
223								aml_start) +
224							       sizeof(struct
225								      acpi_table_header))));
226					}
227				}
228				break;
229			}
230		}
231
232		/* Special processing for certain opcodes */
233
234		switch (op->common.aml_opcode) {
235		case AML_METHOD_OP:
236			/*
237			 * Skip parsing of control method because we don't have enough
238			 * info in the first pass to parse it correctly.
239			 *
240			 * Save the length and address of the body
241			 */
242			op->named.data = walk_state->parser_state.aml;
243			op->named.length = (u32)
244			    (walk_state->parser_state.pkg_end -
245			     walk_state->parser_state.aml);
246
247			/* Skip body of method */
248
249			walk_state->parser_state.aml =
250			    walk_state->parser_state.pkg_end;
251			walk_state->arg_count = 0;
252			break;
253
254		case AML_BUFFER_OP:
255		case AML_PACKAGE_OP:
256		case AML_VAR_PACKAGE_OP:
257
258			if ((op->common.parent) &&
259			    (op->common.parent->common.aml_opcode ==
260			     AML_NAME_OP)
261			    && (walk_state->pass_number <=
262				ACPI_IMODE_LOAD_PASS2)) {
263				/*
264				 * Skip parsing of Buffers and Packages because we don't have
265				 * enough info in the first pass to parse them correctly.
266				 */
267				op->named.data = aml_op_start;
268				op->named.length = (u32)
269				    (walk_state->parser_state.pkg_end -
270				     aml_op_start);
271
272				/* Skip body */
273
274				walk_state->parser_state.aml =
275				    walk_state->parser_state.pkg_end;
276				walk_state->arg_count = 0;
277			}
278			break;
279
280		case AML_WHILE_OP:
281
282			if (walk_state->control_state) {
283				walk_state->control_state->control.package_end =
284				    walk_state->parser_state.pkg_end;
285			}
286			break;
287
288		default:
289
290			/* No action for all other opcodes */
291
292			break;
293		}
294
295		break;
296	}
297
298	return_ACPI_STATUS(AE_OK);
299}
300
301/*******************************************************************************
302 *
303 * FUNCTION:    acpi_ps_link_module_code
304 *
305 * PARAMETERS:  parent_op           - Parent parser op
306 *              aml_start           - Pointer to the AML
307 *              aml_length          - Length of executable AML
308 *              owner_id            - owner_id of module level code
309 *
310 * RETURN:      None.
311 *
312 * DESCRIPTION: Wrap the module-level code with a method object and link the
313 *              object to the global list. Note, the mutex field of the method
314 *              object is used to link multiple module-level code objects.
315 *
316 ******************************************************************************/
317
318static void
319acpi_ps_link_module_code(union acpi_parse_object *parent_op,
320			 u8 *aml_start, u32 aml_length, acpi_owner_id owner_id)
321{
322	union acpi_operand_object *prev;
323	union acpi_operand_object *next;
324	union acpi_operand_object *method_obj;
325	struct acpi_namespace_node *parent_node;
326
327	/* Get the tail of the list */
328
329	prev = next = acpi_gbl_module_code_list;
330	while (next) {
331		prev = next;
332		next = next->method.mutex;
333	}
334
335	/*
336	 * Insert the module level code into the list. Merge it if it is
337	 * adjacent to the previous element.
338	 */
339	if (!prev ||
340	    ((prev->method.aml_start + prev->method.aml_length) != aml_start)) {
341
342		/* Create, initialize, and link a new temporary method object */
343
344		method_obj = acpi_ut_create_internal_object(ACPI_TYPE_METHOD);
345		if (!method_obj) {
346			return;
347		}
348
349		if (parent_op->common.node) {
350			parent_node = parent_op->common.node;
351		} else {
352			parent_node = acpi_gbl_root_node;
353		}
354
355		method_obj->method.aml_start = aml_start;
356		method_obj->method.aml_length = aml_length;
357		method_obj->method.owner_id = owner_id;
358		method_obj->method.info_flags |= ACPI_METHOD_MODULE_LEVEL;
359
360		/*
361		 * Save the parent node in next_object. This is cheating, but we
362		 * don't want to expand the method object.
363		 */
364		method_obj->method.next_object =
365		    ACPI_CAST_PTR(union acpi_operand_object, parent_node);
366
367		if (!prev) {
368			acpi_gbl_module_code_list = method_obj;
369		} else {
370			prev->method.mutex = method_obj;
371		}
372	} else {
373		prev->method.aml_length += aml_length;
374	}
375}
376
377/*******************************************************************************
378 *
379 * FUNCTION:    acpi_ps_parse_loop
380 *
381 * PARAMETERS:  walk_state          - Current state
382 *
383 * RETURN:      Status
384 *
385 * DESCRIPTION: Parse AML (pointed to by the current parser state) and return
386 *              a tree of ops.
387 *
388 ******************************************************************************/
389
390acpi_status acpi_ps_parse_loop(struct acpi_walk_state *walk_state)
391{
392	acpi_status status = AE_OK;
393	union acpi_parse_object *op = NULL;	/* current op */
394	struct acpi_parse_state *parser_state;
395	u8 *aml_op_start = NULL;
396
397	ACPI_FUNCTION_TRACE_PTR(ps_parse_loop, walk_state);
398
399	if (walk_state->descending_callback == NULL) {
400		return_ACPI_STATUS(AE_BAD_PARAMETER);
401	}
402
403	parser_state = &walk_state->parser_state;
404	walk_state->arg_types = 0;
405
406#if (!defined (ACPI_NO_METHOD_EXECUTION) && !defined (ACPI_CONSTANT_EVAL_ONLY))
407
408	if (walk_state->walk_type & ACPI_WALK_METHOD_RESTART) {
409
410		/* We are restarting a preempted control method */
411
412		if (acpi_ps_has_completed_scope(parser_state)) {
413			/*
414			 * We must check if a predicate to an IF or WHILE statement
415			 * was just completed
416			 */
417			if ((parser_state->scope->parse_scope.op) &&
418			    ((parser_state->scope->parse_scope.op->common.
419			      aml_opcode == AML_IF_OP)
420			     || (parser_state->scope->parse_scope.op->common.
421				 aml_opcode == AML_WHILE_OP))
422			    && (walk_state->control_state)
423			    && (walk_state->control_state->common.state ==
424				ACPI_CONTROL_PREDICATE_EXECUTING)) {
425				/*
426				 * A predicate was just completed, get the value of the
427				 * predicate and branch based on that value
428				 */
429				walk_state->op = NULL;
430				status =
431				    acpi_ds_get_predicate_value(walk_state,
432								ACPI_TO_POINTER
433								(TRUE));
434				if (ACPI_FAILURE(status)
435				    && ((status & AE_CODE_MASK) !=
436					AE_CODE_CONTROL)) {
437					if (status == AE_AML_NO_RETURN_VALUE) {
438						ACPI_EXCEPTION((AE_INFO, status,
439								"Invoked method did not return a value"));
440					}
441
442					ACPI_EXCEPTION((AE_INFO, status,
443							"GetPredicate Failed"));
444					return_ACPI_STATUS(status);
445				}
446
447				status =
448				    acpi_ps_next_parse_state(walk_state, op,
449							     status);
450			}
451
452			acpi_ps_pop_scope(parser_state, &op,
453					  &walk_state->arg_types,
454					  &walk_state->arg_count);
455			ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
456					  "Popped scope, Op=%p\n", op));
457		} else if (walk_state->prev_op) {
458
459			/* We were in the middle of an op */
460
461			op = walk_state->prev_op;
462			walk_state->arg_types = walk_state->prev_arg_types;
463		}
464	}
465#endif
466
467	/* Iterative parsing loop, while there is more AML to process: */
468
469	while ((parser_state->aml < parser_state->aml_end) || (op)) {
470		aml_op_start = parser_state->aml;
471		if (!op) {
472			status =
473			    acpi_ps_create_op(walk_state, aml_op_start, &op);
474			if (ACPI_FAILURE(status)) {
475				if (status == AE_CTRL_PARSE_CONTINUE) {
476					continue;
477				}
478
479				if (status == AE_CTRL_PARSE_PENDING) {
480					status = AE_OK;
481				}
482
483				if (status == AE_CTRL_TERMINATE) {
484					return_ACPI_STATUS(status);
485				}
486
487				status =
488				    acpi_ps_complete_op(walk_state, &op,
489							status);
490				if (ACPI_FAILURE(status)) {
491					return_ACPI_STATUS(status);
492				}
493
494				continue;
495			}
496
497			op->common.aml_offset = walk_state->aml_offset;
498
499			if (walk_state->op_info) {
500				ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
501						  "Opcode %4.4X [%s] Op %p Aml %p AmlOffset %5.5X\n",
502						  (u32) op->common.aml_opcode,
503						  walk_state->op_info->name, op,
504						  parser_state->aml,
505						  op->common.aml_offset));
506			}
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