1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2 /******************************************************************************
3 *
4 * Module Name: dsmethod - Parser/Interpreter interface - control method parsing
5 *
6 * Copyright (C) 2000 - 2025, Intel Corp.
7 *
8 *****************************************************************************/
9
10 #include <acpi/acpi.h>
11 #include "accommon.h"
12 #include "acdispat.h"
13 #include "acinterp.h"
14 #include "acnamesp.h"
15 #include "acparser.h"
16 #include "amlcode.h"
17 #include "acdebug.h"
18
19 #define _COMPONENT ACPI_DISPATCHER
20 ACPI_MODULE_NAME("dsmethod")
21
22 /* Local prototypes */
23 static acpi_status
24 acpi_ds_detect_named_opcodes(struct acpi_walk_state *walk_state,
25 union acpi_parse_object **out_op);
26
27 static acpi_status
28 acpi_ds_create_method_mutex(union acpi_operand_object *method_desc);
29
30 /*******************************************************************************
31 *
32 * FUNCTION: acpi_ds_auto_serialize_method
33 *
34 * PARAMETERS: node - Namespace Node of the method
35 * obj_desc - Method object attached to node
36 *
37 * RETURN: Status
38 *
39 * DESCRIPTION: Parse a control method AML to scan for control methods that
40 * need serialization due to the creation of named objects.
41 *
42 * NOTE: It is a bit of overkill to mark all such methods serialized, since
43 * there is only a problem if the method actually blocks during execution.
44 * A blocking operation is, for example, a Sleep() operation, or any access
45 * to an operation region. However, it is probably not possible to easily
46 * detect whether a method will block or not, so we simply mark all suspicious
47 * methods as serialized.
48 *
49 * NOTE2: This code is essentially a generic routine for parsing a single
50 * control method.
51 *
52 ******************************************************************************/
53
54 acpi_status
acpi_ds_auto_serialize_method(struct acpi_namespace_node * node,union acpi_operand_object * obj_desc)55 acpi_ds_auto_serialize_method(struct acpi_namespace_node *node,
56 union acpi_operand_object *obj_desc)
57 {
58 acpi_status status;
59 union acpi_parse_object *op = NULL;
60 struct acpi_walk_state *walk_state;
61
62 ACPI_FUNCTION_TRACE_PTR(ds_auto_serialize_method, node);
63
64 ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
65 "Method auto-serialization parse [%4.4s] %p\n",
66 acpi_ut_get_node_name(node), node));
67
68 /* Create/Init a root op for the method parse tree */
69
70 op = acpi_ps_alloc_op(AML_METHOD_OP, obj_desc->method.aml_start);
71 if (!op) {
72 return_ACPI_STATUS(AE_NO_MEMORY);
73 }
74
75 acpi_ps_set_name(op, node->name.integer);
76 op->common.node = node;
77
78 /* Create and initialize a new walk state */
79
80 walk_state =
81 acpi_ds_create_walk_state(node->owner_id, NULL, NULL, NULL);
82 if (!walk_state) {
83 acpi_ps_free_op(op);
84 return_ACPI_STATUS(AE_NO_MEMORY);
85 }
86
87 status = acpi_ds_init_aml_walk(walk_state, op, node,
88 obj_desc->method.aml_start,
89 obj_desc->method.aml_length, NULL, 0);
90 if (ACPI_FAILURE(status)) {
91 acpi_ds_delete_walk_state(walk_state);
92 acpi_ps_free_op(op);
93 return_ACPI_STATUS(status);
94 }
95
96 walk_state->descending_callback = acpi_ds_detect_named_opcodes;
97
98 /* Parse the method, scan for creation of named objects */
99
100 status = acpi_ps_parse_aml(walk_state);
101
102 acpi_ps_delete_parse_tree(op);
103 return_ACPI_STATUS(status);
104 }
105
106 /*******************************************************************************
107 *
108 * FUNCTION: acpi_ds_detect_named_opcodes
109 *
110 * PARAMETERS: walk_state - Current state of the parse tree walk
111 * out_op - Unused, required for parser interface
112 *
113 * RETURN: Status
114 *
115 * DESCRIPTION: Descending callback used during the loading of ACPI tables.
116 * Currently used to detect methods that must be marked serialized
117 * in order to avoid problems with the creation of named objects.
118 *
119 ******************************************************************************/
120
121 static acpi_status
acpi_ds_detect_named_opcodes(struct acpi_walk_state * walk_state,union acpi_parse_object ** out_op)122 acpi_ds_detect_named_opcodes(struct acpi_walk_state *walk_state,
123 union acpi_parse_object **out_op)
124 {
125
126 ACPI_FUNCTION_NAME(acpi_ds_detect_named_opcodes);
127
128 /* We are only interested in opcodes that create a new name */
129
130 if (!
131 (walk_state->op_info->
132 flags & (AML_NAMED | AML_CREATE | AML_FIELD))) {
133 return (AE_OK);
134 }
135
136 /*
137 * At this point, we know we have a Named object opcode.
138 * Mark the method as serialized. Later code will create a mutex for
139 * this method to enforce serialization.
140 *
141 * Note, ACPI_METHOD_IGNORE_SYNC_LEVEL flag means that we will ignore the
142 * Sync Level mechanism for this method, even though it is now serialized.
143 * Otherwise, there can be conflicts with existing ASL code that actually
144 * uses sync levels.
145 */
146 walk_state->method_desc->method.sync_level = 0;
147 walk_state->method_desc->method.info_flags |=
148 (ACPI_METHOD_SERIALIZED | ACPI_METHOD_IGNORE_SYNC_LEVEL);
149
150 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
151 "Method serialized [%4.4s] %p - [%s] (%4.4X)\n",
152 walk_state->method_node->name.ascii,
153 walk_state->method_node, walk_state->op_info->name,
154 walk_state->opcode));
155
156 /* Abort the parse, no need to examine this method any further */
157
158 return (AE_CTRL_TERMINATE);
159 }
160
161 /*******************************************************************************
162 *
163 * FUNCTION: acpi_ds_method_error
164 *
165 * PARAMETERS: status - Execution status
166 * walk_state - Current state
167 *
168 * RETURN: Status
169 *
170 * DESCRIPTION: Called on method error. Invoke the global exception handler if
171 * present, dump the method data if the debugger is configured
172 *
173 * Note: Allows the exception handler to change the status code
174 *
175 ******************************************************************************/
176
177 acpi_status
acpi_ds_method_error(acpi_status status,struct acpi_walk_state * walk_state)178 acpi_ds_method_error(acpi_status status, struct acpi_walk_state *walk_state)
179 {
180 u32 aml_offset;
181 acpi_name name = 0;
182
183 ACPI_FUNCTION_ENTRY();
184
185 /* Ignore AE_OK and control exception codes */
186
187 if (ACPI_SUCCESS(status) || (status & AE_CODE_CONTROL)) {
188 return (status);
189 }
190
191 /* Invoke the global exception handler */
192
193 if (acpi_gbl_exception_handler) {
194
195 /* Exit the interpreter, allow handler to execute methods */
196
197 acpi_ex_exit_interpreter();
198
199 /*
200 * Handler can map the exception code to anything it wants, including
201 * AE_OK, in which case the executing method will not be aborted.
202 */
203 aml_offset = (u32)ACPI_PTR_DIFF(walk_state->aml,
204 walk_state->parser_state.
205 aml_start);
206
207 if (walk_state->method_node) {
208 name = walk_state->method_node->name.integer;
209 } else if (walk_state->deferred_node) {
210 name = walk_state->deferred_node->name.integer;
211 }
212
213 status = acpi_gbl_exception_handler(status, name,
214 walk_state->opcode,
215 aml_offset, NULL);
216 acpi_ex_enter_interpreter();
217 }
218
219 acpi_ds_clear_implicit_return(walk_state);
220
221 if (ACPI_FAILURE(status)) {
222 acpi_ds_dump_method_stack(status, walk_state, walk_state->op);
223
224 /* Display method locals/args if debugger is present */
225
226 #ifdef ACPI_DEBUGGER
227 acpi_db_dump_method_info(status, walk_state);
228 #endif
229 }
230
231 return (status);
232 }
233
234 /*******************************************************************************
235 *
236 * FUNCTION: acpi_ds_create_method_mutex
237 *
238 * PARAMETERS: obj_desc - The method object
239 *
240 * RETURN: Status
241 *
242 * DESCRIPTION: Create a mutex object for a serialized control method
243 *
244 ******************************************************************************/
245
246 static acpi_status
acpi_ds_create_method_mutex(union acpi_operand_object * method_desc)247 acpi_ds_create_method_mutex(union acpi_operand_object *method_desc)
248 {
249 union acpi_operand_object *mutex_desc;
250 acpi_status status;
251
252 ACPI_FUNCTION_TRACE(ds_create_method_mutex);
253
254 /* Create the new mutex object */
255
256 mutex_desc = acpi_ut_create_internal_object(ACPI_TYPE_MUTEX);
257 if (!mutex_desc) {
258 return_ACPI_STATUS(AE_NO_MEMORY);
259 }
260
261 /* Create the actual OS Mutex */
262
263 status = acpi_os_create_mutex(&mutex_desc->mutex.os_mutex);
264 if (ACPI_FAILURE(status)) {
265 acpi_ut_delete_object_desc(mutex_desc);
266 return_ACPI_STATUS(status);
267 }
268
269 mutex_desc->mutex.sync_level = method_desc->method.sync_level;
270 method_desc->method.mutex = mutex_desc;
271 return_ACPI_STATUS(AE_OK);
272 }
273
274 /*******************************************************************************
275 *
276 * FUNCTION: acpi_ds_begin_method_execution
277 *
278 * PARAMETERS: method_node - Node of the method
279 * obj_desc - The method object
280 * walk_state - current state, NULL if not yet executing
281 * a method.
282 *
283 * RETURN: Status
284 *
285 * DESCRIPTION: Prepare a method for execution. Parses the method if necessary,
286 * increments the thread count, and waits at the method semaphore
287 * for clearance to execute.
288 *
289 ******************************************************************************/
290
291 acpi_status
acpi_ds_begin_method_execution(struct acpi_namespace_node * method_node,union acpi_operand_object * obj_desc,struct acpi_walk_state * walk_state)292 acpi_ds_begin_method_execution(struct acpi_namespace_node *method_node,
293 union acpi_operand_object *obj_desc,
294 struct acpi_walk_state *walk_state)
295 {
296 acpi_status status = AE_OK;
297
298 ACPI_FUNCTION_TRACE_PTR(ds_begin_method_execution, method_node);
299
300 if (!method_node) {
301 return_ACPI_STATUS(AE_NULL_ENTRY);
302 }
303
304 acpi_ex_start_trace_method(method_node, obj_desc, walk_state);
305
306 /* Prevent wraparound of thread count */
307
308 if (obj_desc->method.thread_count == ACPI_UINT8_MAX) {
309 ACPI_ERROR((AE_INFO,
310 "Method reached maximum reentrancy limit (255)"));
311 return_ACPI_STATUS(AE_AML_METHOD_LIMIT);
312 }
313
314 /*
315 * If this method is serialized, we need to acquire the method mutex.
316 */
317 if (obj_desc->method.info_flags & ACPI_METHOD_SERIALIZED) {
318 /*
319 * Create a mutex for the method if it is defined to be Serialized
320 * and a mutex has not already been created. We defer the mutex creation
321 * until a method is actually executed, to minimize the object count
322 */
323 if (!obj_desc->method.mutex) {
324 status = acpi_ds_create_method_mutex(obj_desc);
325 if (ACPI_FAILURE(status)) {
326 return_ACPI_STATUS(status);
327 }
328 }
329
330 /*
331 * The current_sync_level (per-thread) must be less than or equal to
332 * the sync level of the method. This mechanism provides some
333 * deadlock prevention.
334 *
335 * If the method was auto-serialized, we just ignore the sync level
336 * mechanism, because auto-serialization of methods can interfere
337 * with ASL code that actually uses sync levels.
338 *
339 * Top-level method invocation has no walk state at this point
340 */
341 if (walk_state &&
342 (!(obj_desc->method.
343 info_flags & ACPI_METHOD_IGNORE_SYNC_LEVEL))
344 && (walk_state->thread->current_sync_level >
345 obj_desc->method.mutex->mutex.sync_level)) {
346 ACPI_ERROR((AE_INFO,
347 "Cannot acquire Mutex for method [%4.4s]"
348 ", current SyncLevel is too large (%u)",
349 acpi_ut_get_node_name(method_node),
350 walk_state->thread->current_sync_level));
351
352 return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
353 }
354
355 /*
356 * Obtain the method mutex if necessary. Do not acquire mutex for a
357 * recursive call.
358 */
359 if (!walk_state ||
360 !obj_desc->method.mutex->mutex.thread_id ||
361 (walk_state->thread->thread_id !=
362 obj_desc->method.mutex->mutex.thread_id)) {
363 /*
364 * Acquire the method mutex. This releases the interpreter if we
365 * block (and reacquires it before it returns)
366 */
367 status =
368 acpi_ex_system_wait_mutex(obj_desc->method.mutex->
369 mutex.os_mutex,
370 ACPI_WAIT_FOREVER);
371 if (ACPI_FAILURE(status)) {
372 return_ACPI_STATUS(status);
373 }
374
375 /* Update the mutex and walk info and save the original sync_level */
376
377 if (walk_state) {
378 obj_desc->method.mutex->mutex.
379 original_sync_level =
380 walk_state->thread->current_sync_level;
381
382 obj_desc->method.mutex->mutex.thread_id =
383 walk_state->thread->thread_id;
384
385 /*
386 * Update the current sync_level only if this is not an auto-
387 * serialized method. In the auto case, we have to ignore
388 * the sync level for the method mutex (created for the
389 * auto-serialization) because we have no idea of what the
390 * sync level should be. Therefore, just ignore it.
391 */
392 if (!(obj_desc->method.info_flags &
393 ACPI_METHOD_IGNORE_SYNC_LEVEL)) {
394 walk_state->thread->current_sync_level =
395 obj_desc->method.sync_level;
396 }
397 } else {
398 obj_desc->method.mutex->mutex.
399 original_sync_level =
400 obj_desc->method.mutex->mutex.sync_level;
401
402 obj_desc->method.mutex->mutex.thread_id =
403 acpi_os_get_thread_id();
404 }
405 }
406
407 /* Always increase acquisition depth */
408
409 obj_desc->method.mutex->mutex.acquisition_depth++;
410 }
411
412 /*
413 * Allocate an Owner ID for this method, only if this is the first thread
414 * to begin concurrent execution. We only need one owner_id, even if the
415 * method is invoked recursively.
416 */
417 if (!obj_desc->method.owner_id) {
418 status = acpi_ut_allocate_owner_id(&obj_desc->method.owner_id);
419 if (ACPI_FAILURE(status)) {
420 goto cleanup;
421 }
422 }
423
424 /*
425 * Increment the method parse tree thread count since it has been
426 * reentered one more time (even if it is the same thread)
427 */
428 obj_desc->method.thread_count++;
429 acpi_method_count++;
430 return_ACPI_STATUS(status);
431
432 cleanup:
433 /* On error, must release the method mutex (if present) */
434
435 if (obj_desc->method.mutex) {
436 acpi_os_release_mutex(obj_desc->method.mutex->mutex.os_mutex);
437 }
438 return_ACPI_STATUS(status);
439 }
440
441 /*******************************************************************************
442 *
443 * FUNCTION: acpi_ds_call_control_method
444 *
445 * PARAMETERS: thread - Info for this thread
446 * this_walk_state - Current walk state
447 * op - Current Op to be walked
448 *
449 * RETURN: Status
450 *
451 * DESCRIPTION: Transfer execution to a called control method
452 *
453 ******************************************************************************/
454
455 acpi_status
acpi_ds_call_control_method(struct acpi_thread_state * thread,struct acpi_walk_state * this_walk_state,union acpi_parse_object * op)456 acpi_ds_call_control_method(struct acpi_thread_state *thread,
457 struct acpi_walk_state *this_walk_state,
458 union acpi_parse_object *op)
459 {
460 acpi_status status;
461 struct acpi_namespace_node *method_node;
462 struct acpi_walk_state *next_walk_state = NULL;
463 union acpi_operand_object *obj_desc;
464 struct acpi_evaluate_info *info;
465 u32 i;
466
467 ACPI_FUNCTION_TRACE_PTR(ds_call_control_method, this_walk_state);
468
469 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
470 "Calling method %p, currentstate=%p\n",
471 this_walk_state->prev_op, this_walk_state));
472
473 /*
474 * Get the namespace entry for the control method we are about to call
475 */
476 method_node = this_walk_state->method_call_node;
477 if (!method_node) {
478 return_ACPI_STATUS(AE_NULL_ENTRY);
479 }
480
481 obj_desc = acpi_ns_get_attached_object(method_node);
482 if (!obj_desc) {
483 return_ACPI_STATUS(AE_NULL_OBJECT);
484 }
485
486 if (this_walk_state->num_operands < obj_desc->method.param_count) {
487 ACPI_ERROR((AE_INFO, "Missing argument for method [%4.4s]",
488 acpi_ut_get_node_name(method_node)));
489
490 return_ACPI_STATUS(AE_AML_UNINITIALIZED_ARG);
491 }
492
493 /* Init for new method, possibly wait on method mutex */
494
495 status =
496 acpi_ds_begin_method_execution(method_node, obj_desc,
497 this_walk_state);
498 if (ACPI_FAILURE(status)) {
499 return_ACPI_STATUS(status);
500 }
501
502 /* Begin method parse/execution. Create a new walk state */
503
504 next_walk_state =
505 acpi_ds_create_walk_state(obj_desc->method.owner_id, NULL, obj_desc,
506 thread);
507 if (!next_walk_state) {
508 status = AE_NO_MEMORY;
509 goto cleanup;
510 }
511
512 /*
513 * The resolved arguments were put on the previous walk state's operand
514 * stack. Operands on the previous walk state stack always
515 * start at index 0. Also, null terminate the list of arguments
516 */
517 this_walk_state->operands[this_walk_state->num_operands] = NULL;
518
519 /*
520 * Allocate and initialize the evaluation information block
521 * TBD: this is somewhat inefficient, should change interface to
522 * ds_init_aml_walk. For now, keeps this struct off the CPU stack
523 */
524 info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
525 if (!info) {
526 status = AE_NO_MEMORY;
527 goto pop_walk_state;
528 }
529
530 info->parameters = &this_walk_state->operands[0];
531
532 status = acpi_ds_init_aml_walk(next_walk_state, NULL, method_node,
533 obj_desc->method.aml_start,
534 obj_desc->method.aml_length, info,
535 ACPI_IMODE_EXECUTE);
536
537 ACPI_FREE(info);
538 if (ACPI_FAILURE(status)) {
539 goto pop_walk_state;
540 }
541
542 next_walk_state->method_nesting_depth =
543 this_walk_state->method_nesting_depth + 1;
544
545 /*
546 * Delete the operands on the previous walkstate operand stack
547 * (they were copied to new objects)
548 */
549 for (i = 0; i < obj_desc->method.param_count; i++) {
550 acpi_ut_remove_reference(this_walk_state->operands[i]);
551 this_walk_state->operands[i] = NULL;
552 }
553
554 /* Clear the operand stack */
555
556 this_walk_state->num_operands = 0;
557
558 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
559 "**** Begin nested execution of [%4.4s] **** WalkState=%p\n",
560 method_node->name.ascii, next_walk_state));
561
562 this_walk_state->method_pathname =
563 acpi_ns_get_normalized_pathname(method_node, TRUE);
564 this_walk_state->method_is_nested = TRUE;
565
566 /* Optional object evaluation log */
567
568 ACPI_DEBUG_PRINT_RAW((ACPI_DB_EVALUATION,
569 "%-26s: %*s%s\n", " Nested method call",
570 next_walk_state->method_nesting_depth * 3, " ",
571 &this_walk_state->method_pathname[1]));
572
573 /* Invoke an internal method if necessary */
574
575 if (obj_desc->method.info_flags & ACPI_METHOD_INTERNAL_ONLY) {
576 status =
577 obj_desc->method.dispatch.implementation(next_walk_state);
578 if (status == AE_OK) {
579 status = AE_CTRL_TERMINATE;
580 }
581 }
582
583 return_ACPI_STATUS(status);
584
585 pop_walk_state:
586
587 /* On error, pop the walk state to be deleted from thread */
588
589 acpi_ds_pop_walk_state(thread);
590
591 cleanup:
592
593 /* On error, we must terminate the method properly */
594
595 acpi_ds_terminate_control_method(obj_desc, next_walk_state);
596 acpi_ds_delete_walk_state(next_walk_state);
597
598 return_ACPI_STATUS(status);
599 }
600
601 /*******************************************************************************
602 *
603 * FUNCTION: acpi_ds_restart_control_method
604 *
605 * PARAMETERS: walk_state - State for preempted method (caller)
606 * return_desc - Return value from the called method
607 *
608 * RETURN: Status
609 *
610 * DESCRIPTION: Restart a method that was preempted by another (nested) method
611 * invocation. Handle the return value (if any) from the callee.
612 *
613 ******************************************************************************/
614
615 acpi_status
acpi_ds_restart_control_method(struct acpi_walk_state * walk_state,union acpi_operand_object * return_desc)616 acpi_ds_restart_control_method(struct acpi_walk_state *walk_state,
617 union acpi_operand_object *return_desc)
618 {
619 acpi_status status;
620 int same_as_implicit_return;
621
622 ACPI_FUNCTION_TRACE_PTR(ds_restart_control_method, walk_state);
623
624 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
625 "****Restart [%4.4s] Op %p ReturnValueFromCallee %p\n",
626 acpi_ut_get_node_name(walk_state->method_node),
627 walk_state->method_call_op, return_desc));
628
629 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
630 " ReturnFromThisMethodUsed?=%X ResStack %p Walk %p\n",
631 walk_state->return_used,
632 walk_state->results, walk_state));
633
634 /* Did the called method return a value? */
635
636 if (return_desc) {
637
638 /* Is the implicit return object the same as the return desc? */
639
640 same_as_implicit_return =
641 (walk_state->implicit_return_obj == return_desc);
642
643 /* Are we actually going to use the return value? */
644
645 if (walk_state->return_used) {
646
647 /* Save the return value from the previous method */
648
649 status = acpi_ds_result_push(return_desc, walk_state);
650 if (ACPI_FAILURE(status)) {
651 acpi_ut_remove_reference(return_desc);
652 return_ACPI_STATUS(status);
653 }
654
655 /*
656 * Save as THIS method's return value in case it is returned
657 * immediately to yet another method
658 */
659 walk_state->return_desc = return_desc;
660 }
661
662 /*
663 * The following code is the optional support for the so-called
664 * "implicit return". Some AML code assumes that the last value of the
665 * method is "implicitly" returned to the caller, in the absence of an
666 * explicit return value.
667 *
668 * Just save the last result of the method as the return value.
669 *
670 * NOTE: this is optional because the ASL language does not actually
671 * support this behavior.
672 */
673 else if (!acpi_ds_do_implicit_return
674 (return_desc, walk_state, FALSE)
675 || same_as_implicit_return) {
676 /*
677 * Delete the return value if it will not be used by the
678 * calling method or remove one reference if the explicit return
679 * is the same as the implicit return value.
680 */
681 acpi_ut_remove_reference(return_desc);
682 }
683 }
684
685 return_ACPI_STATUS(AE_OK);
686 }
687
688 /*******************************************************************************
689 *
690 * FUNCTION: acpi_ds_terminate_control_method
691 *
692 * PARAMETERS: method_desc - Method object
693 * walk_state - State associated with the method
694 *
695 * RETURN: None
696 *
697 * DESCRIPTION: Terminate a control method. Delete everything that the method
698 * created, delete all locals and arguments, and delete the parse
699 * tree if requested.
700 *
701 * MUTEX: Interpreter is locked
702 *
703 ******************************************************************************/
704
705 void
acpi_ds_terminate_control_method(union acpi_operand_object * method_desc,struct acpi_walk_state * walk_state)706 acpi_ds_terminate_control_method(union acpi_operand_object *method_desc,
707 struct acpi_walk_state *walk_state)
708 {
709
710 ACPI_FUNCTION_TRACE_PTR(ds_terminate_control_method, walk_state);
711
712 /* method_desc is required, walk_state is optional */
713
714 if (!method_desc) {
715 return_VOID;
716 }
717
718 if (walk_state) {
719
720 /* Delete all arguments and locals */
721
722 acpi_ds_method_data_delete_all(walk_state);
723
724 /*
725 * Delete any namespace objects created anywhere within the
726 * namespace by the execution of this method. Unless:
727 * 1) This method is a module-level executable code method, in which
728 * case we want make the objects permanent.
729 * 2) There are other threads executing the method, in which case we
730 * will wait until the last thread has completed.
731 */
732 if (!(method_desc->method.info_flags & ACPI_METHOD_MODULE_LEVEL)
733 && (method_desc->method.thread_count == 1)) {
734
735 /* Delete any direct children of (created by) this method */
736
737 (void)acpi_ex_exit_interpreter();
738 acpi_ns_delete_namespace_subtree(walk_state->
739 method_node);
740 (void)acpi_ex_enter_interpreter();
741
742 /*
743 * Delete any objects that were created by this method
744 * elsewhere in the namespace (if any were created).
745 * Use of the ACPI_METHOD_MODIFIED_NAMESPACE optimizes the
746 * deletion such that we don't have to perform an entire
747 * namespace walk for every control method execution.
748 */
749 if (method_desc->method.
750 info_flags & ACPI_METHOD_MODIFIED_NAMESPACE) {
751 (void)acpi_ex_exit_interpreter();
752 acpi_ns_delete_namespace_by_owner(method_desc->
753 method.
754 owner_id);
755 (void)acpi_ex_enter_interpreter();
756 method_desc->method.info_flags &=
757 ~ACPI_METHOD_MODIFIED_NAMESPACE;
758 }
759 }
760
761 /*
762 * If method is serialized, release the mutex and restore the
763 * current sync level for this thread
764 */
765 if (method_desc->method.mutex) {
766
767 /* Acquisition Depth handles recursive calls */
768
769 method_desc->method.mutex->mutex.acquisition_depth--;
770 if (!method_desc->method.mutex->mutex.acquisition_depth) {
771 walk_state->thread->current_sync_level =
772 method_desc->method.mutex->mutex.
773 original_sync_level;
774
775 acpi_os_release_mutex(method_desc->method.
776 mutex->mutex.os_mutex);
777 method_desc->method.mutex->mutex.thread_id = 0;
778 }
779 }
780 }
781
782 /* Decrement the thread count on the method */
783
784 if (method_desc->method.thread_count) {
785 method_desc->method.thread_count--;
786 } else {
787 ACPI_ERROR((AE_INFO, "Invalid zero thread count in method"));
788 }
789
790 /* Are there any other threads currently executing this method? */
791
792 if (method_desc->method.thread_count) {
793 /*
794 * Additional threads. Do not release the owner_id in this case,
795 * we immediately reuse it for the next thread executing this method
796 */
797 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
798 "*** Completed execution of one thread, %u threads remaining\n",
799 method_desc->method.thread_count));
800 } else {
801 /* This is the only executing thread for this method */
802
803 /*
804 * Support to dynamically change a method from not_serialized to
805 * Serialized if it appears that the method is incorrectly written and
806 * does not support multiple thread execution. The best example of this
807 * is if such a method creates namespace objects and blocks. A second
808 * thread will fail with an AE_ALREADY_EXISTS exception.
809 *
810 * This code is here because we must wait until the last thread exits
811 * before marking the method as serialized.
812 */
813 if (method_desc->method.
814 info_flags & ACPI_METHOD_SERIALIZED_PENDING) {
815 if (walk_state) {
816 ACPI_INFO(("Marking method %4.4s as Serialized "
817 "because of AE_ALREADY_EXISTS error",
818 walk_state->method_node->name.
819 ascii));
820 }
821
822 /*
823 * Method tried to create an object twice and was marked as
824 * "pending serialized". The probable cause is that the method
825 * cannot handle reentrancy.
826 *
827 * The method was created as not_serialized, but it tried to create
828 * a named object and then blocked, causing the second thread
829 * entrance to begin and then fail. Workaround this problem by
830 * marking the method permanently as Serialized when the last
831 * thread exits here.
832 */
833 method_desc->method.info_flags &=
834 ~ACPI_METHOD_SERIALIZED_PENDING;
835
836 method_desc->method.info_flags |=
837 (ACPI_METHOD_SERIALIZED |
838 ACPI_METHOD_IGNORE_SYNC_LEVEL);
839 method_desc->method.sync_level = 0;
840 }
841
842 /* No more threads, we can free the owner_id */
843
844 if (!
845 (method_desc->method.
846 info_flags & ACPI_METHOD_MODULE_LEVEL)) {
847 acpi_ut_release_owner_id(&method_desc->method.owner_id);
848 }
849 }
850
851 acpi_ex_stop_trace_method((struct acpi_namespace_node *)method_desc->
852 method.node, method_desc, walk_state);
853
854 return_VOID;
855 }
856