1 /******************************************************************************
2 *
3 * Module Name: dsmethod - Parser/Interpreter interface - control method parsing
4 *
5 *****************************************************************************/
6
7 /*
8 * Copyright (C) 2000 - 2014, Intel Corp.
9 * All rights reserved.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions, and the following disclaimer,
16 * without modification.
17 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
18 * substantially similar to the "NO WARRANTY" disclaimer below
19 * ("Disclaimer") and any redistribution must be conditioned upon
20 * including a substantially similar Disclaimer requirement for further
21 * binary redistribution.
22 * 3. Neither the names of the above-listed copyright holders nor the names
23 * of any contributors may be used to endorse or promote products derived
24 * from this software without specific prior written permission.
25 *
26 * Alternatively, this software may be distributed under the terms of the
27 * GNU General Public License ("GPL") version 2 as published by the Free
28 * Software Foundation.
29 *
30 * NO WARRANTY
31 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
34 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
40 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
41 * POSSIBILITY OF SUCH DAMAGES.
42 */
43
44 #include <acpi/acpi.h>
45 #include "accommon.h"
46 #include "acdispat.h"
47 #include "acinterp.h"
48 #include "acnamesp.h"
49 #ifdef ACPI_DISASSEMBLER
50 #include "acdisasm.h"
51 #endif
52 #include "acparser.h"
53 #include "amlcode.h"
54
55 #define _COMPONENT ACPI_DISPATCHER
56 ACPI_MODULE_NAME("dsmethod")
57
58 /* Local prototypes */
59 static acpi_status
60 acpi_ds_detect_named_opcodes(struct acpi_walk_state *walk_state,
61 union acpi_parse_object **out_op);
62
63 static acpi_status
64 acpi_ds_create_method_mutex(union acpi_operand_object *method_desc);
65
66 /*******************************************************************************
67 *
68 * FUNCTION: acpi_ds_auto_serialize_method
69 *
70 * PARAMETERS: node - Namespace Node of the method
71 * obj_desc - Method object attached to node
72 *
73 * RETURN: Status
74 *
75 * DESCRIPTION: Parse a control method AML to scan for control methods that
76 * need serialization due to the creation of named objects.
77 *
78 * NOTE: It is a bit of overkill to mark all such methods serialized, since
79 * there is only a problem if the method actually blocks during execution.
80 * A blocking operation is, for example, a Sleep() operation, or any access
81 * to an operation region. However, it is probably not possible to easily
82 * detect whether a method will block or not, so we simply mark all suspicious
83 * methods as serialized.
84 *
85 * NOTE2: This code is essentially a generic routine for parsing a single
86 * control method.
87 *
88 ******************************************************************************/
89
90 acpi_status
acpi_ds_auto_serialize_method(struct acpi_namespace_node * node,union acpi_operand_object * obj_desc)91 acpi_ds_auto_serialize_method(struct acpi_namespace_node *node,
92 union acpi_operand_object *obj_desc)
93 {
94 acpi_status status;
95 union acpi_parse_object *op = NULL;
96 struct acpi_walk_state *walk_state;
97
98 ACPI_FUNCTION_TRACE_PTR(ds_auto_serialize_method, node);
99
100 ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
101 "Method auto-serialization parse [%4.4s] %p\n",
102 acpi_ut_get_node_name(node), node));
103
104 /* Create/Init a root op for the method parse tree */
105
106 op = acpi_ps_alloc_op(AML_METHOD_OP);
107 if (!op) {
108 return_ACPI_STATUS(AE_NO_MEMORY);
109 }
110
111 acpi_ps_set_name(op, node->name.integer);
112 op->common.node = node;
113
114 /* Create and initialize a new walk state */
115
116 walk_state =
117 acpi_ds_create_walk_state(node->owner_id, NULL, NULL, NULL);
118 if (!walk_state) {
119 return_ACPI_STATUS(AE_NO_MEMORY);
120 }
121
122 status =
123 acpi_ds_init_aml_walk(walk_state, op, node,
124 obj_desc->method.aml_start,
125 obj_desc->method.aml_length, NULL, 0);
126 if (ACPI_FAILURE(status)) {
127 acpi_ds_delete_walk_state(walk_state);
128 return_ACPI_STATUS(status);
129 }
130
131 walk_state->descending_callback = acpi_ds_detect_named_opcodes;
132
133 /* Parse the method, scan for creation of named objects */
134
135 status = acpi_ps_parse_aml(walk_state);
136 if (ACPI_FAILURE(status)) {
137 return_ACPI_STATUS(status);
138 }
139
140 acpi_ps_delete_parse_tree(op);
141 return_ACPI_STATUS(status);
142 }
143
144 /*******************************************************************************
145 *
146 * FUNCTION: acpi_ds_detect_named_opcodes
147 *
148 * PARAMETERS: walk_state - Current state of the parse tree walk
149 * out_op - Unused, required for parser interface
150 *
151 * RETURN: Status
152 *
153 * DESCRIPTION: Descending callback used during the loading of ACPI tables.
154 * Currently used to detect methods that must be marked serialized
155 * in order to avoid problems with the creation of named objects.
156 *
157 ******************************************************************************/
158
159 static acpi_status
acpi_ds_detect_named_opcodes(struct acpi_walk_state * walk_state,union acpi_parse_object ** out_op)160 acpi_ds_detect_named_opcodes(struct acpi_walk_state *walk_state,
161 union acpi_parse_object **out_op)
162 {
163
164 ACPI_FUNCTION_NAME(acpi_ds_detect_named_opcodes);
165
166 /* We are only interested in opcodes that create a new name */
167
168 if (!
169 (walk_state->op_info->
170 flags & (AML_NAMED | AML_CREATE | AML_FIELD))) {
171 return (AE_OK);
172 }
173
174 /*
175 * At this point, we know we have a Named object opcode.
176 * Mark the method as serialized. Later code will create a mutex for
177 * this method to enforce serialization.
178 *
179 * Note, ACPI_METHOD_IGNORE_SYNC_LEVEL flag means that we will ignore the
180 * Sync Level mechanism for this method, even though it is now serialized.
181 * Otherwise, there can be conflicts with existing ASL code that actually
182 * uses sync levels.
183 */
184 walk_state->method_desc->method.sync_level = 0;
185 walk_state->method_desc->method.info_flags |=
186 (ACPI_METHOD_SERIALIZED | ACPI_METHOD_IGNORE_SYNC_LEVEL);
187
188 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
189 "Method serialized [%4.4s] %p - [%s] (%4.4X)\n",
190 walk_state->method_node->name.ascii,
191 walk_state->method_node, walk_state->op_info->name,
192 walk_state->opcode));
193
194 /* Abort the parse, no need to examine this method any further */
195
196 return (AE_CTRL_TERMINATE);
197 }
198
199 /*******************************************************************************
200 *
201 * FUNCTION: acpi_ds_method_error
202 *
203 * PARAMETERS: status - Execution status
204 * walk_state - Current state
205 *
206 * RETURN: Status
207 *
208 * DESCRIPTION: Called on method error. Invoke the global exception handler if
209 * present, dump the method data if the disassembler is configured
210 *
211 * Note: Allows the exception handler to change the status code
212 *
213 ******************************************************************************/
214
215 acpi_status
acpi_ds_method_error(acpi_status status,struct acpi_walk_state * walk_state)216 acpi_ds_method_error(acpi_status status, struct acpi_walk_state * walk_state)
217 {
218 ACPI_FUNCTION_ENTRY();
219
220 /* Ignore AE_OK and control exception codes */
221
222 if (ACPI_SUCCESS(status) || (status & AE_CODE_CONTROL)) {
223 return (status);
224 }
225
226 /* Invoke the global exception handler */
227
228 if (acpi_gbl_exception_handler) {
229
230 /* Exit the interpreter, allow handler to execute methods */
231
232 acpi_ex_exit_interpreter();
233
234 /*
235 * Handler can map the exception code to anything it wants, including
236 * AE_OK, in which case the executing method will not be aborted.
237 */
238 status = acpi_gbl_exception_handler(status,
239 walk_state->method_node ?
240 walk_state->method_node->
241 name.integer : 0,
242 walk_state->opcode,
243 walk_state->aml_offset,
244 NULL);
245 acpi_ex_enter_interpreter();
246 }
247
248 acpi_ds_clear_implicit_return(walk_state);
249
250 #ifdef ACPI_DISASSEMBLER
251 if (ACPI_FAILURE(status)) {
252
253 /* Display method locals/args if disassembler is present */
254
255 acpi_dm_dump_method_info(status, walk_state, walk_state->op);
256 }
257 #endif
258
259 return (status);
260 }
261
262 /*******************************************************************************
263 *
264 * FUNCTION: acpi_ds_create_method_mutex
265 *
266 * PARAMETERS: obj_desc - The method object
267 *
268 * RETURN: Status
269 *
270 * DESCRIPTION: Create a mutex object for a serialized control method
271 *
272 ******************************************************************************/
273
274 static acpi_status
acpi_ds_create_method_mutex(union acpi_operand_object * method_desc)275 acpi_ds_create_method_mutex(union acpi_operand_object *method_desc)
276 {
277 union acpi_operand_object *mutex_desc;
278 acpi_status status;
279
280 ACPI_FUNCTION_TRACE(ds_create_method_mutex);
281
282 /* Create the new mutex object */
283
284 mutex_desc = acpi_ut_create_internal_object(ACPI_TYPE_MUTEX);
285 if (!mutex_desc) {
286 return_ACPI_STATUS(AE_NO_MEMORY);
287 }
288
289 /* Create the actual OS Mutex */
290
291 status = acpi_os_create_mutex(&mutex_desc->mutex.os_mutex);
292 if (ACPI_FAILURE(status)) {
293 acpi_ut_delete_object_desc(mutex_desc);
294 return_ACPI_STATUS(status);
295 }
296
297 mutex_desc->mutex.sync_level = method_desc->method.sync_level;
298 method_desc->method.mutex = mutex_desc;
299 return_ACPI_STATUS(AE_OK);
300 }
301
302 /*******************************************************************************
303 *
304 * FUNCTION: acpi_ds_begin_method_execution
305 *
306 * PARAMETERS: method_node - Node of the method
307 * obj_desc - The method object
308 * walk_state - current state, NULL if not yet executing
309 * a method.
310 *
311 * RETURN: Status
312 *
313 * DESCRIPTION: Prepare a method for execution. Parses the method if necessary,
314 * increments the thread count, and waits at the method semaphore
315 * for clearance to execute.
316 *
317 ******************************************************************************/
318
319 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)320 acpi_ds_begin_method_execution(struct acpi_namespace_node *method_node,
321 union acpi_operand_object *obj_desc,
322 struct acpi_walk_state *walk_state)
323 {
324 acpi_status status = AE_OK;
325
326 ACPI_FUNCTION_TRACE_PTR(ds_begin_method_execution, method_node);
327
328 if (!method_node) {
329 return_ACPI_STATUS(AE_NULL_ENTRY);
330 }
331
332 /* Prevent wraparound of thread count */
333
334 if (obj_desc->method.thread_count == ACPI_UINT8_MAX) {
335 ACPI_ERROR((AE_INFO,
336 "Method reached maximum reentrancy limit (255)"));
337 return_ACPI_STATUS(AE_AML_METHOD_LIMIT);
338 }
339
340 /*
341 * If this method is serialized, we need to acquire the method mutex.
342 */
343 if (obj_desc->method.info_flags & ACPI_METHOD_SERIALIZED) {
344 /*
345 * Create a mutex for the method if it is defined to be Serialized
346 * and a mutex has not already been created. We defer the mutex creation
347 * until a method is actually executed, to minimize the object count
348 */
349 if (!obj_desc->method.mutex) {
350 status = acpi_ds_create_method_mutex(obj_desc);
351 if (ACPI_FAILURE(status)) {
352 return_ACPI_STATUS(status);
353 }
354 }
355
356 /*
357 * The current_sync_level (per-thread) must be less than or equal to
358 * the sync level of the method. This mechanism provides some
359 * deadlock prevention.
360 *
361 * If the method was auto-serialized, we just ignore the sync level
362 * mechanism, because auto-serialization of methods can interfere
363 * with ASL code that actually uses sync levels.
364 *
365 * Top-level method invocation has no walk state at this point
366 */
367 if (walk_state &&
368 (!(obj_desc->method.
369 info_flags & ACPI_METHOD_IGNORE_SYNC_LEVEL))
370 && (walk_state->thread->current_sync_level >
371 obj_desc->method.mutex->mutex.sync_level)) {
372 ACPI_ERROR((AE_INFO,
373 "Cannot acquire Mutex for method [%4.4s], current SyncLevel is too large (%u)",
374 acpi_ut_get_node_name(method_node),
375 walk_state->thread->current_sync_level));
376
377 return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
378 }
379
380 /*
381 * Obtain the method mutex if necessary. Do not acquire mutex for a
382 * recursive call.
383 */
384 if (!walk_state ||
385 !obj_desc->method.mutex->mutex.thread_id ||
386 (walk_state->thread->thread_id !=
387 obj_desc->method.mutex->mutex.thread_id)) {
388 /*
389 * Acquire the method mutex. This releases the interpreter if we
390 * block (and reacquires it before it returns)
391 */
392 status =
393 acpi_ex_system_wait_mutex(obj_desc->method.mutex->
394 mutex.os_mutex,
395 ACPI_WAIT_FOREVER);
396 if (ACPI_FAILURE(status)) {
397 return_ACPI_STATUS(status);
398 }
399
400 /* Update the mutex and walk info and save the original sync_level */
401
402 if (walk_state) {
403 obj_desc->method.mutex->mutex.
404 original_sync_level =
405 walk_state->thread->current_sync_level;
406
407 obj_desc->method.mutex->mutex.thread_id =
408 walk_state->thread->thread_id;
409 walk_state->thread->current_sync_level =
410 obj_desc->method.sync_level;
411 } else {
412 obj_desc->method.mutex->mutex.
413 original_sync_level =
414 obj_desc->method.mutex->mutex.sync_level;
415
416 obj_desc->method.mutex->mutex.thread_id =
417 acpi_os_get_thread_id();
418 }
419 }
420
421 /* Always increase acquisition depth */
422
423 obj_desc->method.mutex->mutex.acquisition_depth++;
424 }
425
426 /*
427 * Allocate an Owner ID for this method, only if this is the first thread
428 * to begin concurrent execution. We only need one owner_id, even if the
429 * method is invoked recursively.
430 */
431 if (!obj_desc->method.owner_id) {
432 status = acpi_ut_allocate_owner_id(&obj_desc->method.owner_id);
433 if (ACPI_FAILURE(status)) {
434 goto cleanup;
435 }
436 }
437
438 /*
439 * Increment the method parse tree thread count since it has been
440 * reentered one more time (even if it is the same thread)
441 */
442 obj_desc->method.thread_count++;
443 acpi_method_count++;
444 return_ACPI_STATUS(status);
445
446 cleanup:
447 /* On error, must release the method mutex (if present) */
448
449 if (obj_desc->method.mutex) {
450 acpi_os_release_mutex(obj_desc->method.mutex->mutex.os_mutex);
451 }
452 return_ACPI_STATUS(status);
453 }
454
455 /*******************************************************************************
456 *
457 * FUNCTION: acpi_ds_call_control_method
458 *
459 * PARAMETERS: thread - Info for this thread
460 * this_walk_state - Current walk state
461 * op - Current Op to be walked
462 *
463 * RETURN: Status
464 *
465 * DESCRIPTION: Transfer execution to a called control method
466 *
467 ******************************************************************************/
468
469 acpi_status
acpi_ds_call_control_method(struct acpi_thread_state * thread,struct acpi_walk_state * this_walk_state,union acpi_parse_object * op)470 acpi_ds_call_control_method(struct acpi_thread_state *thread,
471 struct acpi_walk_state *this_walk_state,
472 union acpi_parse_object *op)
473 {
474 acpi_status status;
475 struct acpi_namespace_node *method_node;
476 struct acpi_walk_state *next_walk_state = NULL;
477 union acpi_operand_object *obj_desc;
478 struct acpi_evaluate_info *info;
479 u32 i;
480
481 ACPI_FUNCTION_TRACE_PTR(ds_call_control_method, this_walk_state);
482
483 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
484 "Calling method %p, currentstate=%p\n",
485 this_walk_state->prev_op, this_walk_state));
486
487 /*
488 * Get the namespace entry for the control method we are about to call
489 */
490 method_node = this_walk_state->method_call_node;
491 if (!method_node) {
492 return_ACPI_STATUS(AE_NULL_ENTRY);
493 }
494
495 obj_desc = acpi_ns_get_attached_object(method_node);
496 if (!obj_desc) {
497 return_ACPI_STATUS(AE_NULL_OBJECT);
498 }
499
500 /* Init for new method, possibly wait on method mutex */
501
502 status = acpi_ds_begin_method_execution(method_node, obj_desc,
503 this_walk_state);
504 if (ACPI_FAILURE(status)) {
505 return_ACPI_STATUS(status);
506 }
507
508 /* Begin method parse/execution. Create a new walk state */
509
510 next_walk_state = acpi_ds_create_walk_state(obj_desc->method.owner_id,
511 NULL, obj_desc, thread);
512 if (!next_walk_state) {
513 status = AE_NO_MEMORY;
514 goto cleanup;
515 }
516
517 /*
518 * The resolved arguments were put on the previous walk state's operand
519 * stack. Operands on the previous walk state stack always
520 * start at index 0. Also, null terminate the list of arguments
521 */
522 this_walk_state->operands[this_walk_state->num_operands] = NULL;
523
524 /*
525 * Allocate and initialize the evaluation information block
526 * TBD: this is somewhat inefficient, should change interface to
527 * ds_init_aml_walk. For now, keeps this struct off the CPU stack
528 */
529 info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
530 if (!info) {
531 status = AE_NO_MEMORY;
532 goto cleanup;
533 }
534
535 info->parameters = &this_walk_state->operands[0];
536
537 status = acpi_ds_init_aml_walk(next_walk_state, NULL, method_node,
538 obj_desc->method.aml_start,
539 obj_desc->method.aml_length, info,
540 ACPI_IMODE_EXECUTE);
541
542 ACPI_FREE(info);
543 if (ACPI_FAILURE(status)) {
544 goto cleanup;
545 }
546
547 /*
548 * Delete the operands on the previous walkstate operand stack
549 * (they were copied to new objects)
550 */
551 for (i = 0; i < obj_desc->method.param_count; i++) {
552 acpi_ut_remove_reference(this_walk_state->operands[i]);
553 this_walk_state->operands[i] = NULL;
554 }
555
556 /* Clear the operand stack */
557
558 this_walk_state->num_operands = 0;
559
560 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
561 "**** Begin nested execution of [%4.4s] **** WalkState=%p\n",
562 method_node->name.ascii, next_walk_state));
563
564 /* Invoke an internal method if necessary */
565
566 if (obj_desc->method.info_flags & ACPI_METHOD_INTERNAL_ONLY) {
567 status =
568 obj_desc->method.dispatch.implementation(next_walk_state);
569 if (status == AE_OK) {
570 status = AE_CTRL_TERMINATE;
571 }
572 }
573
574 return_ACPI_STATUS(status);
575
576 cleanup:
577
578 /* On error, we must terminate the method properly */
579
580 acpi_ds_terminate_control_method(obj_desc, next_walk_state);
581 if (next_walk_state) {
582 acpi_ds_delete_walk_state(next_walk_state);
583 }
584
585 return_ACPI_STATUS(status);
586 }
587
588 /*******************************************************************************
589 *
590 * FUNCTION: acpi_ds_restart_control_method
591 *
592 * PARAMETERS: walk_state - State for preempted method (caller)
593 * return_desc - Return value from the called method
594 *
595 * RETURN: Status
596 *
597 * DESCRIPTION: Restart a method that was preempted by another (nested) method
598 * invocation. Handle the return value (if any) from the callee.
599 *
600 ******************************************************************************/
601
602 acpi_status
acpi_ds_restart_control_method(struct acpi_walk_state * walk_state,union acpi_operand_object * return_desc)603 acpi_ds_restart_control_method(struct acpi_walk_state *walk_state,
604 union acpi_operand_object *return_desc)
605 {
606 acpi_status status;
607 int same_as_implicit_return;
608
609 ACPI_FUNCTION_TRACE_PTR(ds_restart_control_method, walk_state);
610
611 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
612 "****Restart [%4.4s] Op %p ReturnValueFromCallee %p\n",
613 acpi_ut_get_node_name(walk_state->method_node),
614 walk_state->method_call_op, return_desc));
615
616 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
617 " ReturnFromThisMethodUsed?=%X ResStack %p Walk %p\n",
618 walk_state->return_used,
619 walk_state->results, walk_state));
620
621 /* Did the called method return a value? */
622
623 if (return_desc) {
624
625 /* Is the implicit return object the same as the return desc? */
626
627 same_as_implicit_return =
628 (walk_state->implicit_return_obj == return_desc);
629
630 /* Are we actually going to use the return value? */
631
632 if (walk_state->return_used) {
633
634 /* Save the return value from the previous method */
635
636 status = acpi_ds_result_push(return_desc, walk_state);
637 if (ACPI_FAILURE(status)) {
638 acpi_ut_remove_reference(return_desc);
639 return_ACPI_STATUS(status);
640 }
641
642 /*
643 * Save as THIS method's return value in case it is returned
644 * immediately to yet another method
645 */
646 walk_state->return_desc = return_desc;
647 }
648
649 /*
650 * The following code is the optional support for the so-called
651 * "implicit return". Some AML code assumes that the last value of the
652 * method is "implicitly" returned to the caller, in the absence of an
653 * explicit return value.
654 *
655 * Just save the last result of the method as the return value.
656 *
657 * NOTE: this is optional because the ASL language does not actually
658 * support this behavior.
659 */
660 else if (!acpi_ds_do_implicit_return
661 (return_desc, walk_state, FALSE)
662 || same_as_implicit_return) {
663 /*
664 * Delete the return value if it will not be used by the
665 * calling method or remove one reference if the explicit return
666 * is the same as the implicit return value.
667 */
668 acpi_ut_remove_reference(return_desc);
669 }
670 }
671
672 return_ACPI_STATUS(AE_OK);
673 }
674
675 /*******************************************************************************
676 *
677 * FUNCTION: acpi_ds_terminate_control_method
678 *
679 * PARAMETERS: method_desc - Method object
680 * walk_state - State associated with the method
681 *
682 * RETURN: None
683 *
684 * DESCRIPTION: Terminate a control method. Delete everything that the method
685 * created, delete all locals and arguments, and delete the parse
686 * tree if requested.
687 *
688 * MUTEX: Interpreter is locked
689 *
690 ******************************************************************************/
691
692 void
acpi_ds_terminate_control_method(union acpi_operand_object * method_desc,struct acpi_walk_state * walk_state)693 acpi_ds_terminate_control_method(union acpi_operand_object *method_desc,
694 struct acpi_walk_state *walk_state)
695 {
696
697 ACPI_FUNCTION_TRACE_PTR(ds_terminate_control_method, walk_state);
698
699 /* method_desc is required, walk_state is optional */
700
701 if (!method_desc) {
702 return_VOID;
703 }
704
705 if (walk_state) {
706
707 /* Delete all arguments and locals */
708
709 acpi_ds_method_data_delete_all(walk_state);
710
711 /*
712 * If method is serialized, release the mutex and restore the
713 * current sync level for this thread
714 */
715 if (method_desc->method.mutex) {
716
717 /* Acquisition Depth handles recursive calls */
718
719 method_desc->method.mutex->mutex.acquisition_depth--;
720 if (!method_desc->method.mutex->mutex.acquisition_depth) {
721 walk_state->thread->current_sync_level =
722 method_desc->method.mutex->mutex.
723 original_sync_level;
724
725 acpi_os_release_mutex(method_desc->method.
726 mutex->mutex.os_mutex);
727 method_desc->method.mutex->mutex.thread_id = 0;
728 }
729 }
730
731 /*
732 * Delete any namespace objects created anywhere within the
733 * namespace by the execution of this method. Unless:
734 * 1) This method is a module-level executable code method, in which
735 * case we want make the objects permanent.
736 * 2) There are other threads executing the method, in which case we
737 * will wait until the last thread has completed.
738 */
739 if (!(method_desc->method.info_flags & ACPI_METHOD_MODULE_LEVEL)
740 && (method_desc->method.thread_count == 1)) {
741
742 /* Delete any direct children of (created by) this method */
743
744 acpi_ns_delete_namespace_subtree(walk_state->
745 method_node);
746
747 /*
748 * Delete any objects that were created by this method
749 * elsewhere in the namespace (if any were created).
750 * Use of the ACPI_METHOD_MODIFIED_NAMESPACE optimizes the
751 * deletion such that we don't have to perform an entire
752 * namespace walk for every control method execution.
753 */
754 if (method_desc->method.
755 info_flags & ACPI_METHOD_MODIFIED_NAMESPACE) {
756 acpi_ns_delete_namespace_by_owner(method_desc->
757 method.
758 owner_id);
759 method_desc->method.info_flags &=
760 ~ACPI_METHOD_MODIFIED_NAMESPACE;
761 }
762 }
763 }
764
765 /* Decrement the thread count on the method */
766
767 if (method_desc->method.thread_count) {
768 method_desc->method.thread_count--;
769 } else {
770 ACPI_ERROR((AE_INFO, "Invalid zero thread count in method"));
771 }
772
773 /* Are there any other threads currently executing this method? */
774
775 if (method_desc->method.thread_count) {
776 /*
777 * Additional threads. Do not release the owner_id in this case,
778 * we immediately reuse it for the next thread executing this method
779 */
780 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
781 "*** Completed execution of one thread, %u threads remaining\n",
782 method_desc->method.thread_count));
783 } else {
784 /* This is the only executing thread for this method */
785
786 /*
787 * Support to dynamically change a method from not_serialized to
788 * Serialized if it appears that the method is incorrectly written and
789 * does not support multiple thread execution. The best example of this
790 * is if such a method creates namespace objects and blocks. A second
791 * thread will fail with an AE_ALREADY_EXISTS exception.
792 *
793 * This code is here because we must wait until the last thread exits
794 * before marking the method as serialized.
795 */
796 if (method_desc->method.
797 info_flags & ACPI_METHOD_SERIALIZED_PENDING) {
798 if (walk_state) {
799 ACPI_INFO((AE_INFO,
800 "Marking method %4.4s as Serialized because of AE_ALREADY_EXISTS error",
801 walk_state->method_node->name.
802 ascii));
803 }
804
805 /*
806 * Method tried to create an object twice and was marked as
807 * "pending serialized". The probable cause is that the method
808 * cannot handle reentrancy.
809 *
810 * The method was created as not_serialized, but it tried to create
811 * a named object and then blocked, causing the second thread
812 * entrance to begin and then fail. Workaround this problem by
813 * marking the method permanently as Serialized when the last
814 * thread exits here.
815 */
816 method_desc->method.info_flags &=
817 ~ACPI_METHOD_SERIALIZED_PENDING;
818 method_desc->method.info_flags |=
819 (ACPI_METHOD_SERIALIZED |
820 ACPI_METHOD_IGNORE_SYNC_LEVEL);
821 method_desc->method.sync_level = 0;
822 }
823
824 /* No more threads, we can free the owner_id */
825
826 if (!
827 (method_desc->method.
828 info_flags & ACPI_METHOD_MODULE_LEVEL)) {
829 acpi_ut_release_owner_id(&method_desc->method.owner_id);
830 }
831 }
832
833 return_VOID;
834 }
835