Merge git://git.infradead.org/battery-2.6
[linux-2.6] / drivers / acpi / parser / psparse.c
1 /******************************************************************************
2  *
3  * Module Name: psparse - Parser top level AML parse routines
4  *
5  *****************************************************************************/
6
7 /*
8  * Copyright (C) 2000 - 2007, R. Byron Moore
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 <acpi/acparser.h>
55 #include <acpi/acdispat.h>
56 #include <acpi/amlcode.h>
57 #include <acpi/acnamesp.h>
58 #include <acpi/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
141         ACPI_FUNCTION_TRACE_PTR(ps_complete_this_op, op);
142
143         /* Check for null Op, can happen if AML code is corrupt */
144
145         if (!op) {
146                 return_ACPI_STATUS(AE_OK);      /* OK for now */
147         }
148
149         /* Delete this op and the subtree below it if asked to */
150
151         if (((walk_state->parse_flags & ACPI_PARSE_TREE_MASK) !=
152              ACPI_PARSE_DELETE_TREE)
153             || (walk_state->op_info->class == AML_CLASS_ARGUMENT)) {
154                 return_ACPI_STATUS(AE_OK);
155         }
156
157         /* Make sure that we only delete this subtree */
158
159         if (op->common.parent) {
160                 prev = op->common.parent->common.value.arg;
161                 if (!prev) {
162
163                         /* Nothing more to do */
164
165                         goto cleanup;
166                 }
167
168                 /*
169                  * Check if we need to replace the operator and its subtree
170                  * with a return value op (placeholder op)
171                  */
172                 parent_info =
173                     acpi_ps_get_opcode_info(op->common.parent->common.
174                                             aml_opcode);
175
176                 switch (parent_info->class) {
177                 case AML_CLASS_CONTROL:
178                         break;
179
180                 case AML_CLASS_CREATE:
181
182                         /*
183                          * These opcodes contain term_arg operands. The current
184                          * op must be replaced by a placeholder return op
185                          */
186                         replacement_op =
187                             acpi_ps_alloc_op(AML_INT_RETURN_VALUE_OP);
188                         if (!replacement_op) {
189                                 goto allocate_error;
190                         }
191                         break;
192
193                 case AML_CLASS_NAMED_OBJECT:
194
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_VAR_PACKAGE_OP)) {
209                                 replacement_op =
210                                     acpi_ps_alloc_op(AML_INT_RETURN_VALUE_OP);
211                                 if (!replacement_op) {
212                                         goto allocate_error;
213                                 }
214                         } else
215                             if ((op->common.parent->common.aml_opcode ==
216                                  AML_NAME_OP)
217                                 && (walk_state->pass_number <=
218                                     ACPI_IMODE_LOAD_PASS2)) {
219                                 if ((op->common.aml_opcode == AML_BUFFER_OP)
220                                     || (op->common.aml_opcode == AML_PACKAGE_OP)
221                                     || (op->common.aml_opcode ==
222                                         AML_VAR_PACKAGE_OP)) {
223                                         replacement_op =
224                                             acpi_ps_alloc_op(op->common.
225                                                              aml_opcode);
226                                         if (!replacement_op) {
227                                                 goto allocate_error;
228                                         }
229
230                                         replacement_op->named.data =
231                                             op->named.data;
232                                         replacement_op->named.length =
233                                             op->named.length;
234                                 }
235                         }
236                         break;
237
238                 default:
239
240                         replacement_op =
241                             acpi_ps_alloc_op(AML_INT_RETURN_VALUE_OP);
242                         if (!replacement_op) {
243                                 goto allocate_error;
244                         }
245                 }
246
247                 /* We must unlink this op from the parent tree */
248
249                 if (prev == op) {
250
251                         /* This op is the first in the list */
252
253                         if (replacement_op) {
254                                 replacement_op->common.parent =
255                                     op->common.parent;
256                                 replacement_op->common.value.arg = NULL;
257                                 replacement_op->common.node = op->common.node;
258                                 op->common.parent->common.value.arg =
259                                     replacement_op;
260                                 replacement_op->common.next = op->common.next;
261                         } else {
262                                 op->common.parent->common.value.arg =
263                                     op->common.next;
264                         }
265                 }
266
267                 /* Search the parent list */
268
269                 else
270                         while (prev) {
271
272                                 /* Traverse all siblings in the parent's argument list */
273
274                                 next = prev->common.next;
275                                 if (next == op) {
276                                         if (replacement_op) {
277                                                 replacement_op->common.parent =
278                                                     op->common.parent;
279                                                 replacement_op->common.value.
280                                                     arg = NULL;
281                                                 replacement_op->common.node =
282                                                     op->common.node;
283                                                 prev->common.next =
284                                                     replacement_op;
285                                                 replacement_op->common.next =
286                                                     op->common.next;
287                                                 next = NULL;
288                                         } else {
289                                                 prev->common.next =
290                                                     op->common.next;
291                                                 next = NULL;
292                                         }
293                                 }
294                                 prev = next;
295                         }
296         }
297
298       cleanup:
299
300         /* Now we can actually delete the subtree rooted at Op */
301
302         acpi_ps_delete_parse_tree(op);
303         return_ACPI_STATUS(AE_OK);
304
305       allocate_error:
306
307         /* Always delete the subtree, even on error */
308
309         acpi_ps_delete_parse_tree(op);
310         return_ACPI_STATUS(AE_NO_MEMORY);
311 }
312
313 /*******************************************************************************
314  *
315  * FUNCTION:    acpi_ps_next_parse_state
316  *
317  * PARAMETERS:  walk_state          - Current state
318  *              Op                  - Current parse op
319  *              callback_status     - Status from previous operation
320  *
321  * RETURN:      Status
322  *
323  * DESCRIPTION: Update the parser state based upon the return exception from
324  *              the parser callback.
325  *
326  ******************************************************************************/
327
328 acpi_status
329 acpi_ps_next_parse_state(struct acpi_walk_state *walk_state,
330                          union acpi_parse_object *op,
331                          acpi_status callback_status)
332 {
333         struct acpi_parse_state *parser_state = &walk_state->parser_state;
334         acpi_status status = AE_CTRL_PENDING;
335
336         ACPI_FUNCTION_TRACE_PTR(ps_next_parse_state, op);
337
338         switch (callback_status) {
339         case AE_CTRL_TERMINATE:
340                 /*
341                  * A control method was terminated via a RETURN statement.
342                  * The walk of this method is complete.
343                  */
344                 parser_state->aml = parser_state->aml_end;
345                 status = AE_CTRL_TERMINATE;
346                 break;
347
348         case AE_CTRL_BREAK:
349
350                 parser_state->aml = walk_state->aml_last_while;
351                 walk_state->control_state->common.value = FALSE;
352                 status = acpi_ds_result_stack_pop(walk_state);
353                 if (ACPI_SUCCESS(status)) {
354                         status = AE_CTRL_BREAK;
355                 }
356                 break;
357
358         case AE_CTRL_CONTINUE:
359
360                 parser_state->aml = walk_state->aml_last_while;
361                 status = acpi_ds_result_stack_pop(walk_state);
362                 if (ACPI_SUCCESS(status)) {
363                         status = AE_CTRL_CONTINUE;
364                 }
365                 break;
366
367         case AE_CTRL_PENDING:
368
369                 parser_state->aml = walk_state->aml_last_while;
370                 break;
371
372 #if 0
373         case AE_CTRL_SKIP:
374
375                 parser_state->aml = parser_state->scope->parse_scope.pkg_end;
376                 status = AE_OK;
377                 break;
378 #endif
379
380         case AE_CTRL_TRUE:
381                 /*
382                  * Predicate of an IF was true, and we are at the matching ELSE.
383                  * Just close out this package
384                  */
385                 parser_state->aml = acpi_ps_get_next_package_end(parser_state);
386                 status = acpi_ds_result_stack_pop(walk_state);
387                 if (ACPI_SUCCESS(status)) {
388                         status = AE_CTRL_PENDING;
389                 }
390                 break;
391
392         case AE_CTRL_FALSE:
393                 /*
394                  * Either an IF/WHILE Predicate was false or we encountered a BREAK
395                  * opcode.  In both cases, we do not execute the rest of the
396                  * package;  We simply close out the parent (finishing the walk of
397                  * this branch of the tree) and continue execution at the parent
398                  * level.
399                  */
400                 parser_state->aml = parser_state->scope->parse_scope.pkg_end;
401
402                 /* In the case of a BREAK, just force a predicate (if any) to FALSE */
403
404                 walk_state->control_state->common.value = FALSE;
405                 status = AE_CTRL_END;
406                 break;
407
408         case AE_CTRL_TRANSFER:
409
410                 /* A method call (invocation) -- transfer control */
411
412                 status = AE_CTRL_TRANSFER;
413                 walk_state->prev_op = op;
414                 walk_state->method_call_op = op;
415                 walk_state->method_call_node =
416                     (op->common.value.arg)->common.node;
417
418                 /* Will return value (if any) be used by the caller? */
419
420                 walk_state->return_used =
421                     acpi_ds_is_result_used(op, walk_state);
422                 break;
423
424         default:
425
426                 status = callback_status;
427                 if ((callback_status & AE_CODE_MASK) == AE_CODE_CONTROL) {
428                         status = AE_OK;
429                 }
430                 break;
431         }
432
433         return_ACPI_STATUS(status);
434 }
435
436 /*******************************************************************************
437  *
438  * FUNCTION:    acpi_ps_parse_aml
439  *
440  * PARAMETERS:  walk_state      - Current state
441  *
442  *
443  * RETURN:      Status
444  *
445  * DESCRIPTION: Parse raw AML and return a tree of ops
446  *
447  ******************************************************************************/
448
449 acpi_status acpi_ps_parse_aml(struct acpi_walk_state *walk_state)
450 {
451         acpi_status status;
452         struct acpi_thread_state *thread;
453         struct acpi_thread_state *prev_walk_list = acpi_gbl_current_walk_list;
454         struct acpi_walk_state *previous_walk_state;
455
456         ACPI_FUNCTION_TRACE(ps_parse_aml);
457
458         ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
459                           "Entered with WalkState=%p Aml=%p size=%X\n",
460                           walk_state, walk_state->parser_state.aml,
461                           walk_state->parser_state.aml_size));
462
463         /* Create and initialize a new thread state */
464
465         thread = acpi_ut_create_thread_state();
466         if (!thread) {
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",
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                                         status =
605                                             acpi_ds_restart_control_method
606                                             (walk_state,
607                                              previous_walk_state->
608                                              implicit_return_obj);
609                                 } else {
610                                         /*
611                                          * We have a valid return value, delete any implicit
612                                          * return value.
613                                          */
614                                         acpi_ds_clear_implicit_return
615                                             (previous_walk_state);
616
617                                         status =
618                                             acpi_ds_restart_control_method
619                                             (walk_state,
620                                              previous_walk_state->return_desc);
621                                 }
622                                 if (ACPI_SUCCESS(status)) {
623                                         walk_state->walk_type |=
624                                             ACPI_WALK_METHOD_RESTART;
625                                 }
626                         } else {
627                                 /* On error, delete any return object */
628
629                                 acpi_ut_remove_reference(previous_walk_state->
630                                                          return_desc);
631                         }
632                 }
633
634                 /*
635                  * Just completed a 1st-level method, save the final internal return
636                  * value (if any)
637                  */
638                 else if (previous_walk_state->caller_return_desc) {
639                         if (previous_walk_state->implicit_return_obj) {
640                                 *(previous_walk_state->caller_return_desc) =
641                                     previous_walk_state->implicit_return_obj;
642                         } else {
643                                 /* NULL if no return value */
644
645                                 *(previous_walk_state->caller_return_desc) =
646                                     previous_walk_state->return_desc;
647                         }
648                 } else {
649                         if (previous_walk_state->return_desc) {
650
651                                 /* Caller doesn't want it, must delete it */
652
653                                 acpi_ut_remove_reference(previous_walk_state->
654                                                          return_desc);
655                         }
656                         if (previous_walk_state->implicit_return_obj) {
657
658                                 /* Caller doesn't want it, must delete it */
659
660                                 acpi_ut_remove_reference(previous_walk_state->
661                                                          implicit_return_obj);
662                         }
663                 }
664
665                 acpi_ds_delete_walk_state(previous_walk_state);
666         }
667
668         /* Normal exit */
669
670         acpi_ex_release_all_mutexes(thread);
671         acpi_ut_delete_generic_state(ACPI_CAST_PTR
672                                      (union acpi_generic_state, thread));
673         acpi_gbl_current_walk_list = prev_walk_list;
674         return_ACPI_STATUS(status);
675 }