ACPICA: hide private headers
[linux-2.6.git] / drivers / acpi / acpica / psparse.c
1 /******************************************************************************
2  *
3  * Module Name: psparse - Parser top level AML parse routines
4  *
5  *****************************************************************************/
6
7 /*
8  * Copyright (C) 2000 - 2008, 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 "acnamesp.h"
59 #include "acinterp.h"
60
61 #define _COMPONENT          ACPI_PARSER
62 ACPI_MODULE_NAME("psparse")
63
64 /*******************************************************************************
65  *
66  * FUNCTION:    acpi_ps_get_opcode_size
67  *
68  * PARAMETERS:  Opcode          - An AML opcode
69  *
70  * RETURN:      Size of the opcode, in bytes (1 or 2)
71  *
72  * DESCRIPTION: Get the size of the current opcode.
73  *
74  ******************************************************************************/
75 u32 acpi_ps_get_opcode_size(u32 opcode)
76 {
77
78         /* Extended (2-byte) opcode if > 255 */
79
80         if (opcode > 0x00FF) {
81                 return (2);
82         }
83
84         /* Otherwise, just a single byte opcode */
85
86         return (1);
87 }
88
89 /*******************************************************************************
90  *
91  * FUNCTION:    acpi_ps_peek_opcode
92  *
93  * PARAMETERS:  parser_state        - A parser state object
94  *
95  * RETURN:      Next AML opcode
96  *
97  * DESCRIPTION: Get next AML opcode (without incrementing AML pointer)
98  *
99  ******************************************************************************/
100
101 u16 acpi_ps_peek_opcode(struct acpi_parse_state * parser_state)
102 {
103         u8 *aml;
104         u16 opcode;
105
106         aml = parser_state->aml;
107         opcode = (u16) ACPI_GET8(aml);
108
109         if (opcode == AML_EXTENDED_OP_PREFIX) {
110
111                 /* Extended opcode, get the second opcode byte */
112
113                 aml++;
114                 opcode = (u16) ((opcode << 8) | ACPI_GET8(aml));
115         }
116
117         return (opcode);
118 }
119
120 /*******************************************************************************
121  *
122  * FUNCTION:    acpi_ps_complete_this_op
123  *
124  * PARAMETERS:  walk_state      - Current State
125  *              Op              - Op to complete
126  *
127  * RETURN:      Status
128  *
129  * DESCRIPTION: Perform any cleanup at the completion of an Op.
130  *
131  ******************************************************************************/
132
133 acpi_status
134 acpi_ps_complete_this_op(struct acpi_walk_state * walk_state,
135                          union acpi_parse_object * op)
136 {
137         union acpi_parse_object *prev;
138         union acpi_parse_object *next;
139         const struct acpi_opcode_info *parent_info;
140         union acpi_parse_object *replacement_op = NULL;
141         acpi_status status = AE_OK;
142
143         ACPI_FUNCTION_TRACE_PTR(ps_complete_this_op, op);
144
145         /* Check for null Op, can happen if AML code is corrupt */
146
147         if (!op) {
148                 return_ACPI_STATUS(AE_OK);      /* OK for now */
149         }
150
151         /* Delete this op and the subtree below it if asked to */
152
153         if (((walk_state->parse_flags & ACPI_PARSE_TREE_MASK) !=
154              ACPI_PARSE_DELETE_TREE)
155             || (walk_state->op_info->class == AML_CLASS_ARGUMENT)) {
156                 return_ACPI_STATUS(AE_OK);
157         }
158
159         /* Make sure that we only delete this subtree */
160
161         if (op->common.parent) {
162                 prev = op->common.parent->common.value.arg;
163                 if (!prev) {
164
165                         /* Nothing more to do */
166
167                         goto cleanup;
168                 }
169
170                 /*
171                  * Check if we need to replace the operator and its subtree
172                  * with a return value op (placeholder op)
173                  */
174                 parent_info =
175                     acpi_ps_get_opcode_info(op->common.parent->common.
176                                             aml_opcode);
177
178                 switch (parent_info->class) {
179                 case AML_CLASS_CONTROL:
180                         break;
181
182                 case AML_CLASS_CREATE:
183
184                         /*
185                          * These opcodes contain term_arg operands. The current
186                          * op must be replaced by a placeholder return op
187                          */
188                         replacement_op =
189                             acpi_ps_alloc_op(AML_INT_RETURN_VALUE_OP);
190                         if (!replacement_op) {
191                                 status = AE_NO_MEMORY;
192                         }
193                         break;
194
195                 case AML_CLASS_NAMED_OBJECT:
196
197                         /*
198                          * These opcodes contain term_arg operands. The current
199                          * op must be replaced by a placeholder return op
200                          */
201                         if ((op->common.parent->common.aml_opcode ==
202                              AML_REGION_OP)
203                             || (op->common.parent->common.aml_opcode ==
204                                 AML_DATA_REGION_OP)
205                             || (op->common.parent->common.aml_opcode ==
206                                 AML_BUFFER_OP)
207                             || (op->common.parent->common.aml_opcode ==
208                                 AML_PACKAGE_OP)
209                             || (op->common.parent->common.aml_opcode ==
210                                 AML_BANK_FIELD_OP)
211                             || (op->common.parent->common.aml_opcode ==
212                                 AML_VAR_PACKAGE_OP)) {
213                                 replacement_op =
214                                     acpi_ps_alloc_op(AML_INT_RETURN_VALUE_OP);
215                                 if (!replacement_op) {
216                                         status = AE_NO_MEMORY;
217                                 }
218                         } else
219                             if ((op->common.parent->common.aml_opcode ==
220                                  AML_NAME_OP)
221                                 && (walk_state->pass_number <=
222                                     ACPI_IMODE_LOAD_PASS2)) {
223                                 if ((op->common.aml_opcode == AML_BUFFER_OP)
224                                     || (op->common.aml_opcode == AML_PACKAGE_OP)
225                                     || (op->common.aml_opcode ==
226                                         AML_VAR_PACKAGE_OP)) {
227                                         replacement_op =
228                                             acpi_ps_alloc_op(op->common.
229                                                              aml_opcode);
230                                         if (!replacement_op) {
231                                                 status = AE_NO_MEMORY;
232                                         } else {
233                                                 replacement_op->named.data =
234                                                     op->named.data;
235                                                 replacement_op->named.length =
236                                                     op->named.length;
237                                         }
238                                 }
239                         }
240                         break;
241
242                 default:
243
244                         replacement_op =
245                             acpi_ps_alloc_op(AML_INT_RETURN_VALUE_OP);
246                         if (!replacement_op) {
247                                 status = AE_NO_MEMORY;
248                         }
249                 }
250
251                 /* We must unlink this op from the parent tree */
252
253                 if (prev == op) {
254
255                         /* This op is the first in the list */
256
257                         if (replacement_op) {
258                                 replacement_op->common.parent =
259                                     op->common.parent;
260                                 replacement_op->common.value.arg = NULL;
261                                 replacement_op->common.node = op->common.node;
262                                 op->common.parent->common.value.arg =
263                                     replacement_op;
264                                 replacement_op->common.next = op->common.next;
265                         } else {
266                                 op->common.parent->common.value.arg =
267                                     op->common.next;
268                         }
269                 }
270
271                 /* Search the parent list */
272
273                 else
274                         while (prev) {
275
276                                 /* Traverse all siblings in the parent's argument list */
277
278                                 next = prev->common.next;
279                                 if (next == op) {
280                                         if (replacement_op) {
281                                                 replacement_op->common.parent =
282                                                     op->common.parent;
283                                                 replacement_op->common.value.
284                                                     arg = NULL;
285                                                 replacement_op->common.node =
286                                                     op->common.node;
287                                                 prev->common.next =
288                                                     replacement_op;
289                                                 replacement_op->common.next =
290                                                     op->common.next;
291                                                 next = NULL;
292                                         } else {
293                                                 prev->common.next =
294                                                     op->common.next;
295                                                 next = NULL;
296                                         }
297                                 }
298                                 prev = next;
299                         }
300         }
301
302       cleanup:
303
304         /* Now we can actually delete the subtree rooted at Op */
305
306         acpi_ps_delete_parse_tree(op);
307         return_ACPI_STATUS(status);
308 }
309
310 /*******************************************************************************
311  *
312  * FUNCTION:    acpi_ps_next_parse_state
313  *
314  * PARAMETERS:  walk_state          - Current state
315  *              Op                  - Current parse op
316  *              callback_status     - Status from previous operation
317  *
318  * RETURN:      Status
319  *
320  * DESCRIPTION: Update the parser state based upon the return exception from
321  *              the parser callback.
322  *
323  ******************************************************************************/
324
325 acpi_status
326 acpi_ps_next_parse_state(struct acpi_walk_state *walk_state,
327                          union acpi_parse_object *op,
328                          acpi_status callback_status)
329 {
330         struct acpi_parse_state *parser_state = &walk_state->parser_state;
331         acpi_status status = AE_CTRL_PENDING;
332
333         ACPI_FUNCTION_TRACE_PTR(ps_next_parse_state, op);
334
335         switch (callback_status) {
336         case AE_CTRL_TERMINATE:
337                 /*
338                  * A control method was terminated via a RETURN statement.
339                  * The walk of this method is complete.
340                  */
341                 parser_state->aml = parser_state->aml_end;
342                 status = AE_CTRL_TERMINATE;
343                 break;
344
345         case AE_CTRL_BREAK:
346
347                 parser_state->aml = walk_state->aml_last_while;
348                 walk_state->control_state->common.value = FALSE;
349                 status = AE_CTRL_BREAK;
350                 break;
351
352         case AE_CTRL_CONTINUE:
353
354                 parser_state->aml = walk_state->aml_last_while;
355                 status = AE_CTRL_CONTINUE;
356                 break;
357
358         case AE_CTRL_PENDING:
359
360                 parser_state->aml = walk_state->aml_last_while;
361                 break;
362
363 #if 0
364         case AE_CTRL_SKIP:
365
366                 parser_state->aml = parser_state->scope->parse_scope.pkg_end;
367                 status = AE_OK;
368                 break;
369 #endif
370
371         case AE_CTRL_TRUE:
372                 /*
373                  * Predicate of an IF was true, and we are at the matching ELSE.
374                  * Just close out this package
375                  */
376                 parser_state->aml = acpi_ps_get_next_package_end(parser_state);
377                 status = AE_CTRL_PENDING;
378                 break;
379
380         case AE_CTRL_FALSE:
381                 /*
382                  * Either an IF/WHILE Predicate was false or we encountered a BREAK
383                  * opcode.  In both cases, we do not execute the rest of the
384                  * package;  We simply close out the parent (finishing the walk of
385                  * this branch of the tree) and continue execution at the parent
386                  * level.
387                  */
388                 parser_state->aml = parser_state->scope->parse_scope.pkg_end;
389
390                 /* In the case of a BREAK, just force a predicate (if any) to FALSE */
391
392                 walk_state->control_state->common.value = FALSE;
393                 status = AE_CTRL_END;
394                 break;
395
396         case AE_CTRL_TRANSFER:
397
398                 /* A method call (invocation) -- transfer control */
399
400                 status = AE_CTRL_TRANSFER;
401                 walk_state->prev_op = op;
402                 walk_state->method_call_op = op;
403                 walk_state->method_call_node =
404                     (op->common.value.arg)->common.node;
405
406                 /* Will return value (if any) be used by the caller? */
407
408                 walk_state->return_used =
409                     acpi_ds_is_result_used(op, walk_state);
410                 break;
411
412         default:
413
414                 status = callback_status;
415                 if ((callback_status & AE_CODE_MASK) == AE_CODE_CONTROL) {
416                         status = AE_OK;
417                 }
418                 break;
419         }
420
421         return_ACPI_STATUS(status);
422 }
423
424 /*******************************************************************************
425  *
426  * FUNCTION:    acpi_ps_parse_aml
427  *
428  * PARAMETERS:  walk_state      - Current state
429  *
430  *
431  * RETURN:      Status
432  *
433  * DESCRIPTION: Parse raw AML and return a tree of ops
434  *
435  ******************************************************************************/
436
437 acpi_status acpi_ps_parse_aml(struct acpi_walk_state *walk_state)
438 {
439         acpi_status status;
440         struct acpi_thread_state *thread;
441         struct acpi_thread_state *prev_walk_list = acpi_gbl_current_walk_list;
442         struct acpi_walk_state *previous_walk_state;
443
444         ACPI_FUNCTION_TRACE(ps_parse_aml);
445
446         ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
447                           "Entered with WalkState=%p Aml=%p size=%X\n",
448                           walk_state, walk_state->parser_state.aml,
449                           walk_state->parser_state.aml_size));
450
451         if (!walk_state->parser_state.aml) {
452                 return_ACPI_STATUS(AE_NULL_OBJECT);
453         }
454
455         /* Create and initialize a new thread state */
456
457         thread = acpi_ut_create_thread_state();
458         if (!thread) {
459                 if (walk_state->method_desc) {
460
461                         /* Executing a control method - additional cleanup */
462
463                         acpi_ds_terminate_control_method(
464                                 walk_state->method_desc, walk_state);
465                 }
466
467                 acpi_ds_delete_walk_state(walk_state);
468                 return_ACPI_STATUS(AE_NO_MEMORY);
469         }
470
471         walk_state->thread = thread;
472
473         /*
474          * If executing a method, the starting sync_level is this method's
475          * sync_level
476          */
477         if (walk_state->method_desc) {
478                 walk_state->thread->current_sync_level =
479                     walk_state->method_desc->method.sync_level;
480         }
481
482         acpi_ds_push_walk_state(walk_state, thread);
483
484         /*
485          * This global allows the AML debugger to get a handle to the currently
486          * executing control method.
487          */
488         acpi_gbl_current_walk_list = thread;
489
490         /*
491          * Execute the walk loop as long as there is a valid Walk State.  This
492          * handles nested control method invocations without recursion.
493          */
494         ACPI_DEBUG_PRINT((ACPI_DB_PARSE, "State=%p\n", walk_state));
495
496         status = AE_OK;
497         while (walk_state) {
498                 if (ACPI_SUCCESS(status)) {
499                         /*
500                          * The parse_loop executes AML until the method terminates
501                          * or calls another method.
502                          */
503                         status = acpi_ps_parse_loop(walk_state);
504                 }
505
506                 ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
507                                   "Completed one call to walk loop, %s State=%p\n",
508                                   acpi_format_exception(status), walk_state));
509
510                 if (status == AE_CTRL_TRANSFER) {
511                         /*
512                          * A method call was detected.
513                          * Transfer control to the called control method
514                          */
515                         status =
516                             acpi_ds_call_control_method(thread, walk_state,
517                                                         NULL);
518                         if (ACPI_FAILURE(status)) {
519                                 status =
520                                     acpi_ds_method_error(status, walk_state);
521                         }
522
523                         /*
524                          * If the transfer to the new method method call worked, a new walk
525                          * state was created -- get it
526                          */
527                         walk_state = acpi_ds_get_current_walk_state(thread);
528                         continue;
529                 } else if (status == AE_CTRL_TERMINATE) {
530                         status = AE_OK;
531                 } else if ((status != AE_OK) && (walk_state->method_desc)) {
532
533                         /* Either the method parse or actual execution failed */
534
535                         ACPI_ERROR_METHOD("Method parse/execution failed",
536                                           walk_state->method_node, NULL,
537                                           status);
538
539                         /* Check for possible multi-thread reentrancy problem */
540
541                         if ((status == AE_ALREADY_EXISTS) &&
542                             (!walk_state->method_desc->method.mutex)) {
543                                 ACPI_INFO((AE_INFO,
544                                            "Marking method %4.4s as Serialized because of AE_ALREADY_EXISTS error",
545                                            walk_state->method_node->name.
546                                            ascii));
547
548                                 /*
549                                  * Method tried to create an object twice. The probable cause is
550                                  * that the method cannot handle reentrancy.
551                                  *
552                                  * The method is marked not_serialized, but it tried to create
553                                  * a named object, causing the second thread entrance to fail.
554                                  * Workaround this problem by marking the method permanently
555                                  * as Serialized.
556                                  */
557                                 walk_state->method_desc->method.method_flags |=
558                                     AML_METHOD_SERIALIZED;
559                                 walk_state->method_desc->method.sync_level = 0;
560                         }
561                 }
562
563                 /* We are done with this walk, move on to the parent if any */
564
565                 walk_state = acpi_ds_pop_walk_state(thread);
566
567                 /* Reset the current scope to the beginning of scope stack */
568
569                 acpi_ds_scope_stack_clear(walk_state);
570
571                 /*
572                  * If we just returned from the execution of a control method or if we
573                  * encountered an error during the method parse phase, there's lots of
574                  * cleanup to do
575                  */
576                 if (((walk_state->parse_flags & ACPI_PARSE_MODE_MASK) ==
577                      ACPI_PARSE_EXECUTE) || (ACPI_FAILURE(status))) {
578                         acpi_ds_terminate_control_method(walk_state->
579                                                          method_desc,
580                                                          walk_state);
581                 }
582
583                 /* Delete this walk state and all linked control states */
584
585                 acpi_ps_cleanup_scope(&walk_state->parser_state);
586                 previous_walk_state = walk_state;
587
588                 ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
589                                   "ReturnValue=%p, ImplicitValue=%p State=%p\n",
590                                   walk_state->return_desc,
591                                   walk_state->implicit_return_obj, walk_state));
592
593                 /* Check if we have restarted a preempted walk */
594
595                 walk_state = acpi_ds_get_current_walk_state(thread);
596                 if (walk_state) {
597                         if (ACPI_SUCCESS(status)) {
598                                 /*
599                                  * There is another walk state, restart it.
600                                  * If the method return value is not used by the parent,
601                                  * The object is deleted
602                                  */
603                                 if (!previous_walk_state->return_desc) {
604                                         /*
605                                          * In slack mode execution, if there is no return value
606                                          * we should implicitly return zero (0) as a default value.
607                                          */
608                                         if (acpi_gbl_enable_interpreter_slack &&
609                                             !previous_walk_state->
610                                             implicit_return_obj) {
611                                                 previous_walk_state->
612                                                     implicit_return_obj =
613                                                     acpi_ut_create_internal_object
614                                                     (ACPI_TYPE_INTEGER);
615                                                 if (!previous_walk_state->
616                                                     implicit_return_obj) {
617                                                         return_ACPI_STATUS
618                                                             (AE_NO_MEMORY);
619                                                 }
620
621                                                 previous_walk_state->
622                                                     implicit_return_obj->
623                                                     integer.value = 0;
624                                         }
625
626                                         /* Restart the calling control method */
627
628                                         status =
629                                             acpi_ds_restart_control_method
630                                             (walk_state,
631                                              previous_walk_state->
632                                              implicit_return_obj);
633                                 } else {
634                                         /*
635                                          * We have a valid return value, delete any implicit
636                                          * return value.
637                                          */
638                                         acpi_ds_clear_implicit_return
639                                             (previous_walk_state);
640
641                                         status =
642                                             acpi_ds_restart_control_method
643                                             (walk_state,
644                                              previous_walk_state->return_desc);
645                                 }
646                                 if (ACPI_SUCCESS(status)) {
647                                         walk_state->walk_type |=
648                                             ACPI_WALK_METHOD_RESTART;
649                                 }
650                         } else {
651                                 /* On error, delete any return object or implicit return */
652
653                                 acpi_ut_remove_reference(previous_walk_state->
654                                                          return_desc);
655                                 acpi_ds_clear_implicit_return
656                                     (previous_walk_state);
657                         }
658                 }
659
660                 /*
661                  * Just completed a 1st-level method, save the final internal return
662                  * value (if any)
663                  */
664                 else if (previous_walk_state->caller_return_desc) {
665                         if (previous_walk_state->implicit_return_obj) {
666                                 *(previous_walk_state->caller_return_desc) =
667                                     previous_walk_state->implicit_return_obj;
668                         } else {
669                                 /* NULL if no return value */
670
671                                 *(previous_walk_state->caller_return_desc) =
672                                     previous_walk_state->return_desc;
673                         }
674                 } else {
675                         if (previous_walk_state->return_desc) {
676
677                                 /* Caller doesn't want it, must delete it */
678
679                                 acpi_ut_remove_reference(previous_walk_state->
680                                                          return_desc);
681                         }
682                         if (previous_walk_state->implicit_return_obj) {
683
684                                 /* Caller doesn't want it, must delete it */
685
686                                 acpi_ut_remove_reference(previous_walk_state->
687                                                          implicit_return_obj);
688                         }
689                 }
690
691                 acpi_ds_delete_walk_state(previous_walk_state);
692         }
693
694         /* Normal exit */
695
696         acpi_ex_release_all_mutexes(thread);
697         acpi_ut_delete_generic_state(ACPI_CAST_PTR
698                                      (union acpi_generic_state, thread));
699         acpi_gbl_current_walk_list = prev_walk_list;
700         return_ACPI_STATUS(status);
701 }