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1 | /****************************************************************************** | |
2 | * | |
3 | * Module Name: psparse - Parser top level AML parse routines | |
4 | * | |
5 | *****************************************************************************/ | |
6 | ||
7 | /* | |
8 | * Copyright (C) 2000 - 2017, Intel Corp. | |
9 | * All rights reserved. | |
10 | * | |
11 | * Redistribution and use in source and binary forms, with or without | |
12 | * modification, are permitted provided that the following conditions | |
13 | * are met: | |
14 | * 1. Redistributions of source code must retain the above copyright | |
15 | * notice, this list of conditions, and the following disclaimer, | |
16 | * without modification. | |
17 | * 2. Redistributions in binary form must reproduce at minimum a disclaimer | |
18 | * substantially similar to the "NO WARRANTY" disclaimer below | |
19 | * ("Disclaimer") and any redistribution must be conditioned upon | |
20 | * including a substantially similar Disclaimer requirement for further | |
21 | * binary redistribution. | |
22 | * 3. Neither the names of the above-listed copyright holders nor the names | |
23 | * of any contributors may be used to endorse or promote products derived | |
24 | * from this software without specific prior written permission. | |
25 | * | |
26 | * Alternatively, this software may be distributed under the terms of the | |
27 | * GNU General Public License ("GPL") version 2 as published by the Free | |
28 | * Software Foundation. | |
29 | * | |
30 | * NO WARRANTY | |
31 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | |
32 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | |
33 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR | |
34 | * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT | |
35 | * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
36 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
37 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
38 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, | |
39 | * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING | |
40 | * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE | |
41 | * POSSIBILITY OF SUCH DAMAGES. | |
42 | */ | |
43 | ||
44 | /* | |
45 | * Parse the AML and build an operation tree as most interpreters, | |
46 | * like Perl, do. Parsing is done by hand rather than with a YACC | |
47 | * generated parser to tightly constrain stack and dynamic memory | |
48 | * usage. At the same time, parsing is kept flexible and the code | |
49 | * fairly compact by parsing based on a list of AML opcode | |
50 | * templates in aml_op_info[] | |
51 | */ | |
52 | ||
53 | #include <acpi/acpi.h> | |
54 | #include "accommon.h" | |
55 | #include "acparser.h" | |
56 | #include "acdispat.h" | |
57 | #include "amlcode.h" | |
58 | #include "acinterp.h" | |
59 | #include "acnamesp.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_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 | acpi_ex_stop_trace_opcode(op, walk_state); | |
152 | ||
153 | /* Delete this op and the subtree below it if asked to */ | |
154 | ||
155 | if (((walk_state->parse_flags & ACPI_PARSE_TREE_MASK) != | |
156 | ACPI_PARSE_DELETE_TREE) | |
157 | || (walk_state->op_info->class == AML_CLASS_ARGUMENT)) { | |
158 | return_ACPI_STATUS(AE_OK); | |
159 | } | |
160 | ||
161 | /* Make sure that we only delete this subtree */ | |
162 | ||
163 | if (op->common.parent) { | |
164 | prev = op->common.parent->common.value.arg; | |
165 | if (!prev) { | |
166 | ||
167 | /* Nothing more to do */ | |
168 | ||
169 | goto cleanup; | |
170 | } | |
171 | ||
172 | /* | |
173 | * Check if we need to replace the operator and its subtree | |
174 | * with a return value op (placeholder op) | |
175 | */ | |
176 | parent_info = | |
177 | acpi_ps_get_opcode_info(op->common.parent->common. | |
178 | aml_opcode); | |
179 | ||
180 | switch (parent_info->class) { | |
181 | case AML_CLASS_CONTROL: | |
182 | ||
183 | break; | |
184 | ||
185 | case AML_CLASS_CREATE: | |
186 | /* | |
187 | * These opcodes contain term_arg operands. The current | |
188 | * op must be replaced by a placeholder return op | |
189 | */ | |
190 | replacement_op = | |
191 | acpi_ps_alloc_op(AML_INT_RETURN_VALUE_OP, | |
192 | op->common.aml); | |
193 | if (!replacement_op) { | |
194 | status = AE_NO_MEMORY; | |
195 | } | |
196 | break; | |
197 | ||
198 | case AML_CLASS_NAMED_OBJECT: | |
199 | /* | |
200 | * These opcodes contain term_arg operands. The current | |
201 | * op must be replaced by a placeholder return op | |
202 | */ | |
203 | if ((op->common.parent->common.aml_opcode == | |
204 | AML_REGION_OP) | |
205 | || (op->common.parent->common.aml_opcode == | |
206 | AML_DATA_REGION_OP) | |
207 | || (op->common.parent->common.aml_opcode == | |
208 | AML_BUFFER_OP) | |
209 | || (op->common.parent->common.aml_opcode == | |
210 | AML_PACKAGE_OP) | |
211 | || (op->common.parent->common.aml_opcode == | |
212 | AML_BANK_FIELD_OP) | |
213 | || (op->common.parent->common.aml_opcode == | |
214 | AML_VARIABLE_PACKAGE_OP)) { | |
215 | replacement_op = | |
216 | acpi_ps_alloc_op(AML_INT_RETURN_VALUE_OP, | |
217 | op->common.aml); | |
218 | if (!replacement_op) { | |
219 | status = AE_NO_MEMORY; | |
220 | } | |
221 | } else | |
222 | if ((op->common.parent->common.aml_opcode == | |
223 | AML_NAME_OP) | |
224 | && (walk_state->pass_number <= | |
225 | ACPI_IMODE_LOAD_PASS2)) { | |
226 | if ((op->common.aml_opcode == AML_BUFFER_OP) | |
227 | || (op->common.aml_opcode == AML_PACKAGE_OP) | |
228 | || (op->common.aml_opcode == | |
229 | AML_VARIABLE_PACKAGE_OP)) { | |
230 | replacement_op = | |
231 | acpi_ps_alloc_op(op->common. | |
232 | aml_opcode, | |
233 | op->common.aml); | |
234 | if (!replacement_op) { | |
235 | status = AE_NO_MEMORY; | |
236 | } else { | |
237 | replacement_op->named.data = | |
238 | op->named.data; | |
239 | replacement_op->named.length = | |
240 | op->named.length; | |
241 | } | |
242 | } | |
243 | } | |
244 | break; | |
245 | ||
246 | default: | |
247 | ||
248 | replacement_op = | |
249 | acpi_ps_alloc_op(AML_INT_RETURN_VALUE_OP, | |
250 | op->common.aml); | |
251 | if (!replacement_op) { | |
252 | status = AE_NO_MEMORY; | |
253 | } | |
254 | } | |
255 | ||
256 | /* We must unlink this op from the parent tree */ | |
257 | ||
258 | if (prev == op) { | |
259 | ||
260 | /* This op is the first in the list */ | |
261 | ||
262 | if (replacement_op) { | |
263 | replacement_op->common.parent = | |
264 | op->common.parent; | |
265 | replacement_op->common.value.arg = NULL; | |
266 | replacement_op->common.node = op->common.node; | |
267 | op->common.parent->common.value.arg = | |
268 | replacement_op; | |
269 | replacement_op->common.next = op->common.next; | |
270 | } else { | |
271 | op->common.parent->common.value.arg = | |
272 | op->common.next; | |
273 | } | |
274 | } | |
275 | ||
276 | /* Search the parent list */ | |
277 | ||
278 | else | |
279 | while (prev) { | |
280 | ||
281 | /* Traverse all siblings in the parent's argument list */ | |
282 | ||
283 | next = prev->common.next; | |
284 | if (next == op) { | |
285 | if (replacement_op) { | |
286 | replacement_op->common.parent = | |
287 | op->common.parent; | |
288 | replacement_op->common.value. | |
289 | arg = NULL; | |
290 | replacement_op->common.node = | |
291 | op->common.node; | |
292 | prev->common.next = | |
293 | replacement_op; | |
294 | replacement_op->common.next = | |
295 | op->common.next; | |
296 | next = NULL; | |
297 | } else { | |
298 | prev->common.next = | |
299 | op->common.next; | |
300 | next = NULL; | |
301 | } | |
302 | } | |
303 | prev = next; | |
304 | } | |
305 | } | |
306 | ||
307 | cleanup: | |
308 | ||
309 | /* Now we can actually delete the subtree rooted at Op */ | |
310 | ||
311 | acpi_ps_delete_parse_tree(op); | |
312 | return_ACPI_STATUS(status); | |
313 | } | |
314 | ||
315 | /******************************************************************************* | |
316 | * | |
317 | * FUNCTION: acpi_ps_next_parse_state | |
318 | * | |
319 | * PARAMETERS: walk_state - Current state | |
320 | * op - Current parse op | |
321 | * callback_status - Status from previous operation | |
322 | * | |
323 | * RETURN: Status | |
324 | * | |
325 | * DESCRIPTION: Update the parser state based upon the return exception from | |
326 | * the parser callback. | |
327 | * | |
328 | ******************************************************************************/ | |
329 | ||
330 | acpi_status | |
331 | acpi_ps_next_parse_state(struct acpi_walk_state *walk_state, | |
332 | union acpi_parse_object *op, | |
333 | acpi_status callback_status) | |
334 | { | |
335 | struct acpi_parse_state *parser_state = &walk_state->parser_state; | |
336 | acpi_status status = AE_CTRL_PENDING; | |
337 | ||
338 | ACPI_FUNCTION_TRACE_PTR(ps_next_parse_state, op); | |
339 | ||
340 | switch (callback_status) { | |
341 | case AE_CTRL_TERMINATE: | |
342 | /* | |
343 | * A control method was terminated via a RETURN statement. | |
344 | * The walk of this method is complete. | |
345 | */ | |
346 | parser_state->aml = parser_state->aml_end; | |
347 | status = AE_CTRL_TERMINATE; | |
348 | break; | |
349 | ||
350 | case AE_CTRL_BREAK: | |
351 | ||
352 | parser_state->aml = walk_state->aml_last_while; | |
353 | walk_state->control_state->common.value = FALSE; | |
354 | status = AE_CTRL_BREAK; | |
355 | break; | |
356 | ||
357 | case AE_CTRL_CONTINUE: | |
358 | ||
359 | parser_state->aml = walk_state->aml_last_while; | |
360 | status = AE_CTRL_CONTINUE; | |
361 | break; | |
362 | ||
363 | case AE_CTRL_PENDING: | |
364 | ||
365 | parser_state->aml = walk_state->aml_last_while; | |
366 | break; | |
367 | ||
368 | #if 0 | |
369 | case AE_CTRL_SKIP: | |
370 | ||
371 | parser_state->aml = parser_state->scope->parse_scope.pkg_end; | |
372 | status = AE_OK; | |
373 | break; | |
374 | #endif | |
375 | ||
376 | case AE_CTRL_TRUE: | |
377 | /* | |
378 | * Predicate of an IF was true, and we are at the matching ELSE. | |
379 | * Just close out this package | |
380 | */ | |
381 | parser_state->aml = acpi_ps_get_next_package_end(parser_state); | |
382 | status = AE_CTRL_PENDING; | |
383 | break; | |
384 | ||
385 | case AE_CTRL_FALSE: | |
386 | /* | |
387 | * Either an IF/WHILE Predicate was false or we encountered a BREAK | |
388 | * opcode. In both cases, we do not execute the rest of the | |
389 | * package; We simply close out the parent (finishing the walk of | |
390 | * this branch of the tree) and continue execution at the parent | |
391 | * level. | |
392 | */ | |
393 | parser_state->aml = parser_state->scope->parse_scope.pkg_end; | |
394 | ||
395 | /* In the case of a BREAK, just force a predicate (if any) to FALSE */ | |
396 | ||
397 | walk_state->control_state->common.value = FALSE; | |
398 | status = AE_CTRL_END; | |
399 | break; | |
400 | ||
401 | case AE_CTRL_TRANSFER: | |
402 | ||
403 | /* A method call (invocation) -- transfer control */ | |
404 | ||
405 | status = AE_CTRL_TRANSFER; | |
406 | walk_state->prev_op = op; | |
407 | walk_state->method_call_op = op; | |
408 | walk_state->method_call_node = | |
409 | (op->common.value.arg)->common.node; | |
410 | ||
411 | /* Will return value (if any) be used by the caller? */ | |
412 | ||
413 | walk_state->return_used = | |
414 | acpi_ds_is_result_used(op, walk_state); | |
415 | break; | |
416 | ||
417 | default: | |
418 | ||
419 | status = callback_status; | |
420 | if ((callback_status & AE_CODE_MASK) == AE_CODE_CONTROL) { | |
421 | status = AE_OK; | |
422 | } | |
423 | break; | |
424 | } | |
425 | ||
426 | return_ACPI_STATUS(status); | |
427 | } | |
428 | ||
429 | /******************************************************************************* | |
430 | * | |
431 | * FUNCTION: acpi_ps_parse_aml | |
432 | * | |
433 | * PARAMETERS: walk_state - Current state | |
434 | * | |
435 | * | |
436 | * RETURN: Status | |
437 | * | |
438 | * DESCRIPTION: Parse raw AML and return a tree of ops | |
439 | * | |
440 | ******************************************************************************/ | |
441 | ||
442 | acpi_status acpi_ps_parse_aml(struct acpi_walk_state *walk_state) | |
443 | { | |
444 | acpi_status status; | |
445 | struct acpi_thread_state *thread; | |
446 | struct acpi_thread_state *prev_walk_list = acpi_gbl_current_walk_list; | |
447 | struct acpi_walk_state *previous_walk_state; | |
448 | ||
449 | ACPI_FUNCTION_TRACE(ps_parse_aml); | |
450 | ||
451 | ACPI_DEBUG_PRINT((ACPI_DB_PARSE, | |
452 | "Entered with WalkState=%p Aml=%p size=%X\n", | |
453 | walk_state, walk_state->parser_state.aml, | |
454 | walk_state->parser_state.aml_size)); | |
455 | ||
456 | if (!walk_state->parser_state.aml) { | |
457 | return_ACPI_STATUS(AE_NULL_OBJECT); | |
458 | } | |
459 | ||
460 | /* Create and initialize a new thread state */ | |
461 | ||
462 | thread = acpi_ut_create_thread_state(); | |
463 | if (!thread) { | |
464 | if (walk_state->method_desc) { | |
465 | ||
466 | /* Executing a control method - additional cleanup */ | |
467 | ||
468 | acpi_ds_terminate_control_method(walk_state-> | |
469 | method_desc, | |
470 | walk_state); | |
471 | } | |
472 | ||
473 | acpi_ds_delete_walk_state(walk_state); | |
474 | return_ACPI_STATUS(AE_NO_MEMORY); | |
475 | } | |
476 | ||
477 | walk_state->thread = thread; | |
478 | ||
479 | /* | |
480 | * If executing a method, the starting sync_level is this method's | |
481 | * sync_level | |
482 | */ | |
483 | if (walk_state->method_desc) { | |
484 | walk_state->thread->current_sync_level = | |
485 | walk_state->method_desc->method.sync_level; | |
486 | } | |
487 | ||
488 | acpi_ds_push_walk_state(walk_state, thread); | |
489 | ||
490 | /* | |
491 | * This global allows the AML debugger to get a handle to the currently | |
492 | * executing control method. | |
493 | */ | |
494 | acpi_gbl_current_walk_list = thread; | |
495 | ||
496 | /* | |
497 | * Execute the walk loop as long as there is a valid Walk State. This | |
498 | * handles nested control method invocations without recursion. | |
499 | */ | |
500 | ACPI_DEBUG_PRINT((ACPI_DB_PARSE, "State=%p\n", walk_state)); | |
501 | ||
502 | status = AE_OK; | |
503 | while (walk_state) { | |
504 | if (ACPI_SUCCESS(status)) { | |
505 | /* | |
506 | * The parse_loop executes AML until the method terminates | |
507 | * or calls another method. | |
508 | */ | |
509 | status = acpi_ps_parse_loop(walk_state); | |
510 | } | |
511 | ||
512 | ACPI_DEBUG_PRINT((ACPI_DB_PARSE, | |
513 | "Completed one call to walk loop, %s State=%p\n", | |
514 | acpi_format_exception(status), walk_state)); | |
515 | ||
516 | if (status == AE_CTRL_TRANSFER) { | |
517 | /* | |
518 | * A method call was detected. | |
519 | * Transfer control to the called control method | |
520 | */ | |
521 | status = | |
522 | acpi_ds_call_control_method(thread, walk_state, | |
523 | NULL); | |
524 | if (ACPI_FAILURE(status)) { | |
525 | status = | |
526 | acpi_ds_method_error(status, walk_state); | |
527 | } | |
528 | ||
529 | /* | |
530 | * If the transfer to the new method method call worked | |
531 | *, a new walk state was created -- get it | |
532 | */ | |
533 | walk_state = acpi_ds_get_current_walk_state(thread); | |
534 | continue; | |
535 | } else if (status == AE_CTRL_TERMINATE) { | |
536 | status = AE_OK; | |
537 | } else if ((status != AE_OK) && (walk_state->method_desc)) { | |
538 | ||
539 | /* Either the method parse or actual execution failed */ | |
540 | ||
541 | acpi_ex_exit_interpreter(); | |
542 | if (status == AE_ABORT_METHOD) { | |
543 | acpi_ns_print_node_pathname(walk_state-> | |
544 | method_node, | |
545 | "Method aborted:"); | |
546 | acpi_os_printf("\n"); | |
547 | } else { | |
548 | ACPI_ERROR_METHOD | |
549 | ("Method parse/execution failed", | |
550 | walk_state->method_node, NULL, status); | |
551 | } | |
552 | acpi_ex_enter_interpreter(); | |
553 | ||
554 | /* Check for possible multi-thread reentrancy problem */ | |
555 | ||
556 | if ((status == AE_ALREADY_EXISTS) && | |
557 | (!(walk_state->method_desc->method.info_flags & | |
558 | ACPI_METHOD_SERIALIZED))) { | |
559 | /* | |
560 | * Method is not serialized and tried to create an object | |
561 | * twice. The probable cause is that the method cannot | |
562 | * handle reentrancy. Mark as "pending serialized" now, and | |
563 | * then mark "serialized" when the last thread exits. | |
564 | */ | |
565 | walk_state->method_desc->method.info_flags |= | |
566 | ACPI_METHOD_SERIALIZED_PENDING; | |
567 | } | |
568 | } | |
569 | ||
570 | /* We are done with this walk, move on to the parent if any */ | |
571 | ||
572 | walk_state = acpi_ds_pop_walk_state(thread); | |
573 | ||
574 | /* Reset the current scope to the beginning of scope stack */ | |
575 | ||
576 | acpi_ds_scope_stack_clear(walk_state); | |
577 | ||
578 | /* | |
579 | * If we just returned from the execution of a control method or if we | |
580 | * encountered an error during the method parse phase, there's lots of | |
581 | * cleanup to do | |
582 | */ | |
583 | if (((walk_state->parse_flags & ACPI_PARSE_MODE_MASK) == | |
584 | ACPI_PARSE_EXECUTE && | |
585 | !(walk_state->parse_flags & ACPI_PARSE_MODULE_LEVEL)) || | |
586 | (ACPI_FAILURE(status))) { | |
587 | acpi_ds_terminate_control_method(walk_state-> | |
588 | method_desc, | |
589 | walk_state); | |
590 | } | |
591 | ||
592 | /* Delete this walk state and all linked control states */ | |
593 | ||
594 | acpi_ps_cleanup_scope(&walk_state->parser_state); | |
595 | previous_walk_state = walk_state; | |
596 | ||
597 | ACPI_DEBUG_PRINT((ACPI_DB_PARSE, | |
598 | "ReturnValue=%p, ImplicitValue=%p State=%p\n", | |
599 | walk_state->return_desc, | |
600 | walk_state->implicit_return_obj, walk_state)); | |
601 | ||
602 | /* Check if we have restarted a preempted walk */ | |
603 | ||
604 | walk_state = acpi_ds_get_current_walk_state(thread); | |
605 | if (walk_state) { | |
606 | if (ACPI_SUCCESS(status)) { | |
607 | /* | |
608 | * There is another walk state, restart it. | |
609 | * If the method return value is not used by the parent, | |
610 | * The object is deleted | |
611 | */ | |
612 | if (!previous_walk_state->return_desc) { | |
613 | /* | |
614 | * In slack mode execution, if there is no return value | |
615 | * we should implicitly return zero (0) as a default value. | |
616 | */ | |
617 | if (acpi_gbl_enable_interpreter_slack && | |
618 | !previous_walk_state-> | |
619 | implicit_return_obj) { | |
620 | previous_walk_state-> | |
621 | implicit_return_obj = | |
622 | acpi_ut_create_integer_object | |
623 | ((u64) 0); | |
624 | if (!previous_walk_state-> | |
625 | implicit_return_obj) { | |
626 | return_ACPI_STATUS | |
627 | (AE_NO_MEMORY); | |
628 | } | |
629 | } | |
630 | ||
631 | /* Restart the calling control method */ | |
632 | ||
633 | status = | |
634 | acpi_ds_restart_control_method | |
635 | (walk_state, | |
636 | previous_walk_state-> | |
637 | implicit_return_obj); | |
638 | } else { | |
639 | /* | |
640 | * We have a valid return value, delete any implicit | |
641 | * return value. | |
642 | */ | |
643 | acpi_ds_clear_implicit_return | |
644 | (previous_walk_state); | |
645 | ||
646 | status = | |
647 | acpi_ds_restart_control_method | |
648 | (walk_state, | |
649 | previous_walk_state->return_desc); | |
650 | } | |
651 | if (ACPI_SUCCESS(status)) { | |
652 | walk_state->walk_type |= | |
653 | ACPI_WALK_METHOD_RESTART; | |
654 | } | |
655 | } else { | |
656 | /* On error, delete any return object or implicit return */ | |
657 | ||
658 | acpi_ut_remove_reference(previous_walk_state-> | |
659 | return_desc); | |
660 | acpi_ds_clear_implicit_return | |
661 | (previous_walk_state); | |
662 | } | |
663 | } | |
664 | ||
665 | /* | |
666 | * Just completed a 1st-level method, save the final internal return | |
667 | * value (if any) | |
668 | */ | |
669 | else if (previous_walk_state->caller_return_desc) { | |
670 | if (previous_walk_state->implicit_return_obj) { | |
671 | *(previous_walk_state->caller_return_desc) = | |
672 | previous_walk_state->implicit_return_obj; | |
673 | } else { | |
674 | /* NULL if no return value */ | |
675 | ||
676 | *(previous_walk_state->caller_return_desc) = | |
677 | previous_walk_state->return_desc; | |
678 | } | |
679 | } else { | |
680 | if (previous_walk_state->return_desc) { | |
681 | ||
682 | /* Caller doesn't want it, must delete it */ | |
683 | ||
684 | acpi_ut_remove_reference(previous_walk_state-> | |
685 | return_desc); | |
686 | } | |
687 | if (previous_walk_state->implicit_return_obj) { | |
688 | ||
689 | /* Caller doesn't want it, must delete it */ | |
690 | ||
691 | acpi_ut_remove_reference(previous_walk_state-> | |
692 | implicit_return_obj); | |
693 | } | |
694 | } | |
695 | ||
696 | acpi_ds_delete_walk_state(previous_walk_state); | |
697 | } | |
698 | ||
699 | /* Normal exit */ | |
700 | ||
701 | acpi_ex_release_all_mutexes(thread); | |
702 | acpi_ut_delete_generic_state(ACPI_CAST_PTR | |
703 | (union acpi_generic_state, thread)); | |
704 | acpi_gbl_current_walk_list = prev_walk_list; | |
705 | return_ACPI_STATUS(status); | |
706 | } |