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 - 2023, 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 |
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, aml: obj_desc->method.aml_start); |
71 | if (!op) { |
72 | return_ACPI_STATUS(AE_NO_MEMORY); |
73 | } |
74 | |
75 | acpi_ps_set_name(op, name: 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(owner_id: 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, method_node: node, |
88 | aml_start: obj_desc->method.aml_start, |
89 | aml_length: obj_desc->method.aml_length, NULL, pass_number: 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(root: 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 |
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 |
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, op: 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 |
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(object: 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 |
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(method_desc: 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(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(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 |
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(node: method_node); |
482 | if (!obj_desc) { |
483 | return_ACPI_STATUS(AE_NULL_OBJECT); |
484 | } |
485 | |
486 | /* Init for new method, possibly wait on method mutex */ |
487 | |
488 | status = |
489 | acpi_ds_begin_method_execution(method_node, obj_desc, |
490 | walk_state: this_walk_state); |
491 | if (ACPI_FAILURE(status)) { |
492 | return_ACPI_STATUS(status); |
493 | } |
494 | |
495 | /* Begin method parse/execution. Create a new walk state */ |
496 | |
497 | next_walk_state = |
498 | acpi_ds_create_walk_state(owner_id: obj_desc->method.owner_id, NULL, mth_desc: obj_desc, |
499 | thread); |
500 | if (!next_walk_state) { |
501 | status = AE_NO_MEMORY; |
502 | goto cleanup; |
503 | } |
504 | |
505 | /* |
506 | * The resolved arguments were put on the previous walk state's operand |
507 | * stack. Operands on the previous walk state stack always |
508 | * start at index 0. Also, null terminate the list of arguments |
509 | */ |
510 | this_walk_state->operands[this_walk_state->num_operands] = NULL; |
511 | |
512 | /* |
513 | * Allocate and initialize the evaluation information block |
514 | * TBD: this is somewhat inefficient, should change interface to |
515 | * ds_init_aml_walk. For now, keeps this struct off the CPU stack |
516 | */ |
517 | info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info)); |
518 | if (!info) { |
519 | status = AE_NO_MEMORY; |
520 | goto pop_walk_state; |
521 | } |
522 | |
523 | info->parameters = &this_walk_state->operands[0]; |
524 | |
525 | status = acpi_ds_init_aml_walk(walk_state: next_walk_state, NULL, method_node, |
526 | aml_start: obj_desc->method.aml_start, |
527 | aml_length: obj_desc->method.aml_length, info, |
528 | pass_number: ACPI_IMODE_EXECUTE); |
529 | |
530 | ACPI_FREE(info); |
531 | if (ACPI_FAILURE(status)) { |
532 | goto pop_walk_state; |
533 | } |
534 | |
535 | next_walk_state->method_nesting_depth = |
536 | this_walk_state->method_nesting_depth + 1; |
537 | |
538 | /* |
539 | * Delete the operands on the previous walkstate operand stack |
540 | * (they were copied to new objects) |
541 | */ |
542 | for (i = 0; i < obj_desc->method.param_count; i++) { |
543 | acpi_ut_remove_reference(object: this_walk_state->operands[i]); |
544 | this_walk_state->operands[i] = NULL; |
545 | } |
546 | |
547 | /* Clear the operand stack */ |
548 | |
549 | this_walk_state->num_operands = 0; |
550 | |
551 | ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, |
552 | "**** Begin nested execution of [%4.4s] **** WalkState=%p\n" , |
553 | method_node->name.ascii, next_walk_state)); |
554 | |
555 | this_walk_state->method_pathname = |
556 | acpi_ns_get_normalized_pathname(node: method_node, TRUE); |
557 | this_walk_state->method_is_nested = TRUE; |
558 | |
559 | /* Optional object evaluation log */ |
560 | |
561 | ACPI_DEBUG_PRINT_RAW((ACPI_DB_EVALUATION, |
562 | "%-26s: %*s%s\n" , " Nested method call" , |
563 | next_walk_state->method_nesting_depth * 3, " " , |
564 | &this_walk_state->method_pathname[1])); |
565 | |
566 | /* Invoke an internal method if necessary */ |
567 | |
568 | if (obj_desc->method.info_flags & ACPI_METHOD_INTERNAL_ONLY) { |
569 | status = |
570 | obj_desc->method.dispatch.implementation(next_walk_state); |
571 | if (status == AE_OK) { |
572 | status = AE_CTRL_TERMINATE; |
573 | } |
574 | } |
575 | |
576 | return_ACPI_STATUS(status); |
577 | |
578 | pop_walk_state: |
579 | |
580 | /* On error, pop the walk state to be deleted from thread */ |
581 | |
582 | acpi_ds_pop_walk_state(thread); |
583 | |
584 | cleanup: |
585 | |
586 | /* On error, we must terminate the method properly */ |
587 | |
588 | acpi_ds_terminate_control_method(method_desc: obj_desc, walk_state: next_walk_state); |
589 | acpi_ds_delete_walk_state(walk_state: next_walk_state); |
590 | |
591 | return_ACPI_STATUS(status); |
592 | } |
593 | |
594 | /******************************************************************************* |
595 | * |
596 | * FUNCTION: acpi_ds_restart_control_method |
597 | * |
598 | * PARAMETERS: walk_state - State for preempted method (caller) |
599 | * return_desc - Return value from the called method |
600 | * |
601 | * RETURN: Status |
602 | * |
603 | * DESCRIPTION: Restart a method that was preempted by another (nested) method |
604 | * invocation. Handle the return value (if any) from the callee. |
605 | * |
606 | ******************************************************************************/ |
607 | |
608 | acpi_status |
609 | acpi_ds_restart_control_method(struct acpi_walk_state *walk_state, |
610 | union acpi_operand_object *return_desc) |
611 | { |
612 | acpi_status status; |
613 | int same_as_implicit_return; |
614 | |
615 | ACPI_FUNCTION_TRACE_PTR(ds_restart_control_method, walk_state); |
616 | |
617 | ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, |
618 | "****Restart [%4.4s] Op %p ReturnValueFromCallee %p\n" , |
619 | acpi_ut_get_node_name(walk_state->method_node), |
620 | walk_state->method_call_op, return_desc)); |
621 | |
622 | ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, |
623 | " ReturnFromThisMethodUsed?=%X ResStack %p Walk %p\n" , |
624 | walk_state->return_used, |
625 | walk_state->results, walk_state)); |
626 | |
627 | /* Did the called method return a value? */ |
628 | |
629 | if (return_desc) { |
630 | |
631 | /* Is the implicit return object the same as the return desc? */ |
632 | |
633 | same_as_implicit_return = |
634 | (walk_state->implicit_return_obj == return_desc); |
635 | |
636 | /* Are we actually going to use the return value? */ |
637 | |
638 | if (walk_state->return_used) { |
639 | |
640 | /* Save the return value from the previous method */ |
641 | |
642 | status = acpi_ds_result_push(object: return_desc, walk_state); |
643 | if (ACPI_FAILURE(status)) { |
644 | acpi_ut_remove_reference(object: return_desc); |
645 | return_ACPI_STATUS(status); |
646 | } |
647 | |
648 | /* |
649 | * Save as THIS method's return value in case it is returned |
650 | * immediately to yet another method |
651 | */ |
652 | walk_state->return_desc = return_desc; |
653 | } |
654 | |
655 | /* |
656 | * The following code is the optional support for the so-called |
657 | * "implicit return". Some AML code assumes that the last value of the |
658 | * method is "implicitly" returned to the caller, in the absence of an |
659 | * explicit return value. |
660 | * |
661 | * Just save the last result of the method as the return value. |
662 | * |
663 | * NOTE: this is optional because the ASL language does not actually |
664 | * support this behavior. |
665 | */ |
666 | else if (!acpi_ds_do_implicit_return |
667 | (return_desc, walk_state, FALSE) |
668 | || same_as_implicit_return) { |
669 | /* |
670 | * Delete the return value if it will not be used by the |
671 | * calling method or remove one reference if the explicit return |
672 | * is the same as the implicit return value. |
673 | */ |
674 | acpi_ut_remove_reference(object: return_desc); |
675 | } |
676 | } |
677 | |
678 | return_ACPI_STATUS(AE_OK); |
679 | } |
680 | |
681 | /******************************************************************************* |
682 | * |
683 | * FUNCTION: acpi_ds_terminate_control_method |
684 | * |
685 | * PARAMETERS: method_desc - Method object |
686 | * walk_state - State associated with the method |
687 | * |
688 | * RETURN: None |
689 | * |
690 | * DESCRIPTION: Terminate a control method. Delete everything that the method |
691 | * created, delete all locals and arguments, and delete the parse |
692 | * tree if requested. |
693 | * |
694 | * MUTEX: Interpreter is locked |
695 | * |
696 | ******************************************************************************/ |
697 | |
698 | void |
699 | acpi_ds_terminate_control_method(union acpi_operand_object *method_desc, |
700 | struct acpi_walk_state *walk_state) |
701 | { |
702 | |
703 | ACPI_FUNCTION_TRACE_PTR(ds_terminate_control_method, walk_state); |
704 | |
705 | /* method_desc is required, walk_state is optional */ |
706 | |
707 | if (!method_desc) { |
708 | return_VOID; |
709 | } |
710 | |
711 | if (walk_state) { |
712 | |
713 | /* Delete all arguments and locals */ |
714 | |
715 | acpi_ds_method_data_delete_all(walk_state); |
716 | |
717 | /* |
718 | * Delete any namespace objects created anywhere within the |
719 | * namespace by the execution of this method. Unless: |
720 | * 1) This method is a module-level executable code method, in which |
721 | * case we want make the objects permanent. |
722 | * 2) There are other threads executing the method, in which case we |
723 | * will wait until the last thread has completed. |
724 | */ |
725 | if (!(method_desc->method.info_flags & ACPI_METHOD_MODULE_LEVEL) |
726 | && (method_desc->method.thread_count == 1)) { |
727 | |
728 | /* Delete any direct children of (created by) this method */ |
729 | |
730 | (void)acpi_ex_exit_interpreter(); |
731 | acpi_ns_delete_namespace_subtree(parent_handle: walk_state-> |
732 | method_node); |
733 | (void)acpi_ex_enter_interpreter(); |
734 | |
735 | /* |
736 | * Delete any objects that were created by this method |
737 | * elsewhere in the namespace (if any were created). |
738 | * Use of the ACPI_METHOD_MODIFIED_NAMESPACE optimizes the |
739 | * deletion such that we don't have to perform an entire |
740 | * namespace walk for every control method execution. |
741 | */ |
742 | if (method_desc->method. |
743 | info_flags & ACPI_METHOD_MODIFIED_NAMESPACE) { |
744 | (void)acpi_ex_exit_interpreter(); |
745 | acpi_ns_delete_namespace_by_owner(owner_id: method_desc-> |
746 | method. |
747 | owner_id); |
748 | (void)acpi_ex_enter_interpreter(); |
749 | method_desc->method.info_flags &= |
750 | ~ACPI_METHOD_MODIFIED_NAMESPACE; |
751 | } |
752 | } |
753 | |
754 | /* |
755 | * If method is serialized, release the mutex and restore the |
756 | * current sync level for this thread |
757 | */ |
758 | if (method_desc->method.mutex) { |
759 | |
760 | /* Acquisition Depth handles recursive calls */ |
761 | |
762 | method_desc->method.mutex->mutex.acquisition_depth--; |
763 | if (!method_desc->method.mutex->mutex.acquisition_depth) { |
764 | walk_state->thread->current_sync_level = |
765 | method_desc->method.mutex->mutex. |
766 | original_sync_level; |
767 | |
768 | acpi_os_release_mutex(method_desc->method. |
769 | mutex->mutex.os_mutex); |
770 | method_desc->method.mutex->mutex.thread_id = 0; |
771 | } |
772 | } |
773 | } |
774 | |
775 | /* Decrement the thread count on the method */ |
776 | |
777 | if (method_desc->method.thread_count) { |
778 | method_desc->method.thread_count--; |
779 | } else { |
780 | ACPI_ERROR((AE_INFO, "Invalid zero thread count in method" )); |
781 | } |
782 | |
783 | /* Are there any other threads currently executing this method? */ |
784 | |
785 | if (method_desc->method.thread_count) { |
786 | /* |
787 | * Additional threads. Do not release the owner_id in this case, |
788 | * we immediately reuse it for the next thread executing this method |
789 | */ |
790 | ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, |
791 | "*** Completed execution of one thread, %u threads remaining\n" , |
792 | method_desc->method.thread_count)); |
793 | } else { |
794 | /* This is the only executing thread for this method */ |
795 | |
796 | /* |
797 | * Support to dynamically change a method from not_serialized to |
798 | * Serialized if it appears that the method is incorrectly written and |
799 | * does not support multiple thread execution. The best example of this |
800 | * is if such a method creates namespace objects and blocks. A second |
801 | * thread will fail with an AE_ALREADY_EXISTS exception. |
802 | * |
803 | * This code is here because we must wait until the last thread exits |
804 | * before marking the method as serialized. |
805 | */ |
806 | if (method_desc->method. |
807 | info_flags & ACPI_METHOD_SERIALIZED_PENDING) { |
808 | if (walk_state) { |
809 | ACPI_INFO(("Marking method %4.4s as Serialized " |
810 | "because of AE_ALREADY_EXISTS error" , |
811 | walk_state->method_node->name. |
812 | ascii)); |
813 | } |
814 | |
815 | /* |
816 | * Method tried to create an object twice and was marked as |
817 | * "pending serialized". The probable cause is that the method |
818 | * cannot handle reentrancy. |
819 | * |
820 | * The method was created as not_serialized, but it tried to create |
821 | * a named object and then blocked, causing the second thread |
822 | * entrance to begin and then fail. Workaround this problem by |
823 | * marking the method permanently as Serialized when the last |
824 | * thread exits here. |
825 | */ |
826 | method_desc->method.info_flags &= |
827 | ~ACPI_METHOD_SERIALIZED_PENDING; |
828 | |
829 | method_desc->method.info_flags |= |
830 | (ACPI_METHOD_SERIALIZED | |
831 | ACPI_METHOD_IGNORE_SYNC_LEVEL); |
832 | method_desc->method.sync_level = 0; |
833 | } |
834 | |
835 | /* No more threads, we can free the owner_id */ |
836 | |
837 | if (! |
838 | (method_desc->method. |
839 | info_flags & ACPI_METHOD_MODULE_LEVEL)) { |
840 | acpi_ut_release_owner_id(owner_id: &method_desc->method.owner_id); |
841 | } |
842 | } |
843 | |
844 | acpi_ex_stop_trace_method(method_node: (struct acpi_namespace_node *)method_desc-> |
845 | method.node, obj_desc: method_desc, walk_state); |
846 | |
847 | return_VOID; |
848 | } |
849 | |