1 /******************************************************************************
2 *
3 * Module Name: dsmethod - Parser/Interpreter interface - control method parsing
4 *
5 *****************************************************************************/
6
7 /*
8 * Copyright (C) 2000 - 2011, 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 <acpi/acdisasm.h>
51 #endif
52
53 #define _COMPONENT ACPI_DISPATCHER
54 ACPI_MODULE_NAME("dsmethod")
55
56 /* Local prototypes */
57 static acpi_status
58 acpi_ds_create_method_mutex(union acpi_operand_object *method_desc);
59
60 /*******************************************************************************
61 *
62 * FUNCTION: acpi_ds_method_error
63 *
64 * PARAMETERS: Status - Execution status
65 * walk_state - Current state
66 *
67 * RETURN: Status
68 *
69 * DESCRIPTION: Called on method error. Invoke the global exception handler if
70 * present, dump the method data if the disassembler is configured
71 *
72 * Note: Allows the exception handler to change the status code
73 *
74 ******************************************************************************/
75
76 acpi_status
acpi_ds_method_error(acpi_status status,struct acpi_walk_state * walk_state)77 acpi_ds_method_error(acpi_status status, struct acpi_walk_state *walk_state)
78 {
79 ACPI_FUNCTION_ENTRY();
80
81 /* Ignore AE_OK and control exception codes */
82
83 if (ACPI_SUCCESS(status) || (status & AE_CODE_CONTROL)) {
84 return (status);
85 }
86
87 /* Invoke the global exception handler */
88
89 if (acpi_gbl_exception_handler) {
90
91 /* Exit the interpreter, allow handler to execute methods */
92
93 acpi_ex_exit_interpreter();
94
95 /*
96 * Handler can map the exception code to anything it wants, including
97 * AE_OK, in which case the executing method will not be aborted.
98 */
99 status = acpi_gbl_exception_handler(status,
100 walk_state->method_node ?
101 walk_state->method_node->
102 name.integer : 0,
103 walk_state->opcode,
104 walk_state->aml_offset,
105 NULL);
106 acpi_ex_enter_interpreter();
107 }
108
109 acpi_ds_clear_implicit_return(walk_state);
110
111 #ifdef ACPI_DISASSEMBLER
112 if (ACPI_FAILURE(status)) {
113
114 /* Display method locals/args if disassembler is present */
115
116 acpi_dm_dump_method_info(status, walk_state, walk_state->op);
117 }
118 #endif
119
120 return (status);
121 }
122
123 /*******************************************************************************
124 *
125 * FUNCTION: acpi_ds_create_method_mutex
126 *
127 * PARAMETERS: obj_desc - The method object
128 *
129 * RETURN: Status
130 *
131 * DESCRIPTION: Create a mutex object for a serialized control method
132 *
133 ******************************************************************************/
134
135 static acpi_status
acpi_ds_create_method_mutex(union acpi_operand_object * method_desc)136 acpi_ds_create_method_mutex(union acpi_operand_object *method_desc)
137 {
138 union acpi_operand_object *mutex_desc;
139 acpi_status status;
140
141 ACPI_FUNCTION_TRACE(ds_create_method_mutex);
142
143 /* Create the new mutex object */
144
145 mutex_desc = acpi_ut_create_internal_object(ACPI_TYPE_MUTEX);
146 if (!mutex_desc) {
147 return_ACPI_STATUS(AE_NO_MEMORY);
148 }
149
150 /* Create the actual OS Mutex */
151
152 status = acpi_os_create_mutex(&mutex_desc->mutex.os_mutex);
153 if (ACPI_FAILURE(status)) {
154 return_ACPI_STATUS(status);
155 }
156
157 mutex_desc->mutex.sync_level = method_desc->method.sync_level;
158 method_desc->method.mutex = mutex_desc;
159 return_ACPI_STATUS(AE_OK);
160 }
161
162 /*******************************************************************************
163 *
164 * FUNCTION: acpi_ds_begin_method_execution
165 *
166 * PARAMETERS: method_node - Node of the method
167 * obj_desc - The method object
168 * walk_state - current state, NULL if not yet executing
169 * a method.
170 *
171 * RETURN: Status
172 *
173 * DESCRIPTION: Prepare a method for execution. Parses the method if necessary,
174 * increments the thread count, and waits at the method semaphore
175 * for clearance to execute.
176 *
177 ******************************************************************************/
178
179 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)180 acpi_ds_begin_method_execution(struct acpi_namespace_node *method_node,
181 union acpi_operand_object *obj_desc,
182 struct acpi_walk_state *walk_state)
183 {
184 acpi_status status = AE_OK;
185
186 ACPI_FUNCTION_TRACE_PTR(ds_begin_method_execution, method_node);
187
188 if (!method_node) {
189 return_ACPI_STATUS(AE_NULL_ENTRY);
190 }
191
192 /* Prevent wraparound of thread count */
193
194 if (obj_desc->method.thread_count == ACPI_UINT8_MAX) {
195 ACPI_ERROR((AE_INFO,
196 "Method reached maximum reentrancy limit (255)"));
197 return_ACPI_STATUS(AE_AML_METHOD_LIMIT);
198 }
199
200 /*
201 * If this method is serialized, we need to acquire the method mutex.
202 */
203 if (obj_desc->method.info_flags & ACPI_METHOD_SERIALIZED) {
204 /*
205 * Create a mutex for the method if it is defined to be Serialized
206 * and a mutex has not already been created. We defer the mutex creation
207 * until a method is actually executed, to minimize the object count
208 */
209 if (!obj_desc->method.mutex) {
210 status = acpi_ds_create_method_mutex(obj_desc);
211 if (ACPI_FAILURE(status)) {
212 return_ACPI_STATUS(status);
213 }
214 }
215
216 /*
217 * The current_sync_level (per-thread) must be less than or equal to
218 * the sync level of the method. This mechanism provides some
219 * deadlock prevention
220 *
221 * Top-level method invocation has no walk state at this point
222 */
223 if (walk_state &&
224 (walk_state->thread->current_sync_level >
225 obj_desc->method.mutex->mutex.sync_level)) {
226 ACPI_ERROR((AE_INFO,
227 "Cannot acquire Mutex for method [%4.4s], current SyncLevel is too large (%u)",
228 acpi_ut_get_node_name(method_node),
229 walk_state->thread->current_sync_level));
230
231 return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
232 }
233
234 /*
235 * Obtain the method mutex if necessary. Do not acquire mutex for a
236 * recursive call.
237 */
238 if (!walk_state ||
239 !obj_desc->method.mutex->mutex.thread_id ||
240 (walk_state->thread->thread_id !=
241 obj_desc->method.mutex->mutex.thread_id)) {
242 /*
243 * Acquire the method mutex. This releases the interpreter if we
244 * block (and reacquires it before it returns)
245 */
246 status =
247 acpi_ex_system_wait_mutex(obj_desc->method.mutex->
248 mutex.os_mutex,
249 ACPI_WAIT_FOREVER);
250 if (ACPI_FAILURE(status)) {
251 return_ACPI_STATUS(status);
252 }
253
254 /* Update the mutex and walk info and save the original sync_level */
255
256 if (walk_state) {
257 obj_desc->method.mutex->mutex.
258 original_sync_level =
259 walk_state->thread->current_sync_level;
260
261 obj_desc->method.mutex->mutex.thread_id =
262 walk_state->thread->thread_id;
263 walk_state->thread->current_sync_level =
264 obj_desc->method.sync_level;
265 } else {
266 obj_desc->method.mutex->mutex.
267 original_sync_level =
268 obj_desc->method.mutex->mutex.sync_level;
269 }
270 }
271
272 /* Always increase acquisition depth */
273
274 obj_desc->method.mutex->mutex.acquisition_depth++;
275 }
276
277 /*
278 * Allocate an Owner ID for this method, only if this is the first thread
279 * to begin concurrent execution. We only need one owner_id, even if the
280 * method is invoked recursively.
281 */
282 if (!obj_desc->method.owner_id) {
283 status = acpi_ut_allocate_owner_id(&obj_desc->method.owner_id);
284 if (ACPI_FAILURE(status)) {
285 goto cleanup;
286 }
287 }
288
289 /*
290 * Increment the method parse tree thread count since it has been
291 * reentered one more time (even if it is the same thread)
292 */
293 obj_desc->method.thread_count++;
294 return_ACPI_STATUS(status);
295
296 cleanup:
297 /* On error, must release the method mutex (if present) */
298
299 if (obj_desc->method.mutex) {
300 acpi_os_release_mutex(obj_desc->method.mutex->mutex.os_mutex);
301 }
302 return_ACPI_STATUS(status);
303 }
304
305 /*******************************************************************************
306 *
307 * FUNCTION: acpi_ds_call_control_method
308 *
309 * PARAMETERS: Thread - Info for this thread
310 * this_walk_state - Current walk state
311 * Op - Current Op to be walked
312 *
313 * RETURN: Status
314 *
315 * DESCRIPTION: Transfer execution to a called control method
316 *
317 ******************************************************************************/
318
319 acpi_status
acpi_ds_call_control_method(struct acpi_thread_state * thread,struct acpi_walk_state * this_walk_state,union acpi_parse_object * op)320 acpi_ds_call_control_method(struct acpi_thread_state *thread,
321 struct acpi_walk_state *this_walk_state,
322 union acpi_parse_object *op)
323 {
324 acpi_status status;
325 struct acpi_namespace_node *method_node;
326 struct acpi_walk_state *next_walk_state = NULL;
327 union acpi_operand_object *obj_desc;
328 struct acpi_evaluate_info *info;
329 u32 i;
330
331 ACPI_FUNCTION_TRACE_PTR(ds_call_control_method, this_walk_state);
332
333 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
334 "Calling method %p, currentstate=%p\n",
335 this_walk_state->prev_op, this_walk_state));
336
337 /*
338 * Get the namespace entry for the control method we are about to call
339 */
340 method_node = this_walk_state->method_call_node;
341 if (!method_node) {
342 return_ACPI_STATUS(AE_NULL_ENTRY);
343 }
344
345 obj_desc = acpi_ns_get_attached_object(method_node);
346 if (!obj_desc) {
347 return_ACPI_STATUS(AE_NULL_OBJECT);
348 }
349
350 /* Init for new method, possibly wait on method mutex */
351
352 status = acpi_ds_begin_method_execution(method_node, obj_desc,
353 this_walk_state);
354 if (ACPI_FAILURE(status)) {
355 return_ACPI_STATUS(status);
356 }
357
358 /* Begin method parse/execution. Create a new walk state */
359
360 next_walk_state = acpi_ds_create_walk_state(obj_desc->method.owner_id,
361 NULL, obj_desc, thread);
362 if (!next_walk_state) {
363 status = AE_NO_MEMORY;
364 goto cleanup;
365 }
366
367 /*
368 * The resolved arguments were put on the previous walk state's operand
369 * stack. Operands on the previous walk state stack always
370 * start at index 0. Also, null terminate the list of arguments
371 */
372 this_walk_state->operands[this_walk_state->num_operands] = NULL;
373
374 /*
375 * Allocate and initialize the evaluation information block
376 * TBD: this is somewhat inefficient, should change interface to
377 * ds_init_aml_walk. For now, keeps this struct off the CPU stack
378 */
379 info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
380 if (!info) {
381 return_ACPI_STATUS(AE_NO_MEMORY);
382 }
383
384 info->parameters = &this_walk_state->operands[0];
385
386 status = acpi_ds_init_aml_walk(next_walk_state, NULL, method_node,
387 obj_desc->method.aml_start,
388 obj_desc->method.aml_length, info,
389 ACPI_IMODE_EXECUTE);
390
391 ACPI_FREE(info);
392 if (ACPI_FAILURE(status)) {
393 goto cleanup;
394 }
395
396 /*
397 * Delete the operands on the previous walkstate operand stack
398 * (they were copied to new objects)
399 */
400 for (i = 0; i < obj_desc->method.param_count; i++) {
401 acpi_ut_remove_reference(this_walk_state->operands[i]);
402 this_walk_state->operands[i] = NULL;
403 }
404
405 /* Clear the operand stack */
406
407 this_walk_state->num_operands = 0;
408
409 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
410 "**** Begin nested execution of [%4.4s] **** WalkState=%p\n",
411 method_node->name.ascii, next_walk_state));
412
413 /* Invoke an internal method if necessary */
414
415 if (obj_desc->method.info_flags & ACPI_METHOD_INTERNAL_ONLY) {
416 status =
417 obj_desc->method.dispatch.implementation(next_walk_state);
418 if (status == AE_OK) {
419 status = AE_CTRL_TERMINATE;
420 }
421 }
422
423 return_ACPI_STATUS(status);
424
425 cleanup:
426
427 /* On error, we must terminate the method properly */
428
429 acpi_ds_terminate_control_method(obj_desc, next_walk_state);
430 if (next_walk_state) {
431 acpi_ds_delete_walk_state(next_walk_state);
432 }
433
434 return_ACPI_STATUS(status);
435 }
436
437 /*******************************************************************************
438 *
439 * FUNCTION: acpi_ds_restart_control_method
440 *
441 * PARAMETERS: walk_state - State for preempted method (caller)
442 * return_desc - Return value from the called method
443 *
444 * RETURN: Status
445 *
446 * DESCRIPTION: Restart a method that was preempted by another (nested) method
447 * invocation. Handle the return value (if any) from the callee.
448 *
449 ******************************************************************************/
450
451 acpi_status
acpi_ds_restart_control_method(struct acpi_walk_state * walk_state,union acpi_operand_object * return_desc)452 acpi_ds_restart_control_method(struct acpi_walk_state *walk_state,
453 union acpi_operand_object *return_desc)
454 {
455 acpi_status status;
456 int same_as_implicit_return;
457
458 ACPI_FUNCTION_TRACE_PTR(ds_restart_control_method, walk_state);
459
460 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
461 "****Restart [%4.4s] Op %p ReturnValueFromCallee %p\n",
462 acpi_ut_get_node_name(walk_state->method_node),
463 walk_state->method_call_op, return_desc));
464
465 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
466 " ReturnFromThisMethodUsed?=%X ResStack %p Walk %p\n",
467 walk_state->return_used,
468 walk_state->results, walk_state));
469
470 /* Did the called method return a value? */
471
472 if (return_desc) {
473
474 /* Is the implicit return object the same as the return desc? */
475
476 same_as_implicit_return =
477 (walk_state->implicit_return_obj == return_desc);
478
479 /* Are we actually going to use the return value? */
480
481 if (walk_state->return_used) {
482
483 /* Save the return value from the previous method */
484
485 status = acpi_ds_result_push(return_desc, walk_state);
486 if (ACPI_FAILURE(status)) {
487 acpi_ut_remove_reference(return_desc);
488 return_ACPI_STATUS(status);
489 }
490
491 /*
492 * Save as THIS method's return value in case it is returned
493 * immediately to yet another method
494 */
495 walk_state->return_desc = return_desc;
496 }
497
498 /*
499 * The following code is the optional support for the so-called
500 * "implicit return". Some AML code assumes that the last value of the
501 * method is "implicitly" returned to the caller, in the absence of an
502 * explicit return value.
503 *
504 * Just save the last result of the method as the return value.
505 *
506 * NOTE: this is optional because the ASL language does not actually
507 * support this behavior.
508 */
509 else if (!acpi_ds_do_implicit_return
510 (return_desc, walk_state, FALSE)
511 || same_as_implicit_return) {
512 /*
513 * Delete the return value if it will not be used by the
514 * calling method or remove one reference if the explicit return
515 * is the same as the implicit return value.
516 */
517 acpi_ut_remove_reference(return_desc);
518 }
519 }
520
521 return_ACPI_STATUS(AE_OK);
522 }
523
524 /*******************************************************************************
525 *
526 * FUNCTION: acpi_ds_terminate_control_method
527 *
528 * PARAMETERS: method_desc - Method object
529 * walk_state - State associated with the method
530 *
531 * RETURN: None
532 *
533 * DESCRIPTION: Terminate a control method. Delete everything that the method
534 * created, delete all locals and arguments, and delete the parse
535 * tree if requested.
536 *
537 * MUTEX: Interpreter is locked
538 *
539 ******************************************************************************/
540
541 void
acpi_ds_terminate_control_method(union acpi_operand_object * method_desc,struct acpi_walk_state * walk_state)542 acpi_ds_terminate_control_method(union acpi_operand_object *method_desc,
543 struct acpi_walk_state *walk_state)
544 {
545
546 ACPI_FUNCTION_TRACE_PTR(ds_terminate_control_method, walk_state);
547
548 /* method_desc is required, walk_state is optional */
549
550 if (!method_desc) {
551 return_VOID;
552 }
553
554 if (walk_state) {
555
556 /* Delete all arguments and locals */
557
558 acpi_ds_method_data_delete_all(walk_state);
559
560 /*
561 * If method is serialized, release the mutex and restore the
562 * current sync level for this thread
563 */
564 if (method_desc->method.mutex) {
565
566 /* Acquisition Depth handles recursive calls */
567
568 method_desc->method.mutex->mutex.acquisition_depth--;
569 if (!method_desc->method.mutex->mutex.acquisition_depth) {
570 walk_state->thread->current_sync_level =
571 method_desc->method.mutex->mutex.
572 original_sync_level;
573
574 acpi_os_release_mutex(method_desc->method.
575 mutex->mutex.os_mutex);
576 method_desc->method.mutex->mutex.thread_id = 0;
577 }
578 }
579
580 /*
581 * Delete any namespace objects created anywhere within the
582 * namespace by the execution of this method. Unless:
583 * 1) This method is a module-level executable code method, in which
584 * case we want make the objects permanent.
585 * 2) There are other threads executing the method, in which case we
586 * will wait until the last thread has completed.
587 */
588 if (!(method_desc->method.info_flags & ACPI_METHOD_MODULE_LEVEL)
589 && (method_desc->method.thread_count == 1)) {
590
591 /* Delete any direct children of (created by) this method */
592
593 acpi_ns_delete_namespace_subtree(walk_state->
594 method_node);
595
596 /*
597 * Delete any objects that were created by this method
598 * elsewhere in the namespace (if any were created).
599 * Use of the ACPI_METHOD_MODIFIED_NAMESPACE optimizes the
600 * deletion such that we don't have to perform an entire
601 * namespace walk for every control method execution.
602 */
603 if (method_desc->method.
604 info_flags & ACPI_METHOD_MODIFIED_NAMESPACE) {
605 acpi_ns_delete_namespace_by_owner(method_desc->
606 method.
607 owner_id);
608 method_desc->method.info_flags &=
609 ~ACPI_METHOD_MODIFIED_NAMESPACE;
610 }
611 }
612 }
613
614 /* Decrement the thread count on the method */
615
616 if (method_desc->method.thread_count) {
617 method_desc->method.thread_count--;
618 } else {
619 ACPI_ERROR((AE_INFO, "Invalid zero thread count in method"));
620 }
621
622 /* Are there any other threads currently executing this method? */
623
624 if (method_desc->method.thread_count) {
625 /*
626 * Additional threads. Do not release the owner_id in this case,
627 * we immediately reuse it for the next thread executing this method
628 */
629 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
630 "*** Completed execution of one thread, %u threads remaining\n",
631 method_desc->method.thread_count));
632 } else {
633 /* This is the only executing thread for this method */
634
635 /*
636 * Support to dynamically change a method from not_serialized to
637 * Serialized if it appears that the method is incorrectly written and
638 * does not support multiple thread execution. The best example of this
639 * is if such a method creates namespace objects and blocks. A second
640 * thread will fail with an AE_ALREADY_EXISTS exception.
641 *
642 * This code is here because we must wait until the last thread exits
643 * before marking the method as serialized.
644 */
645 if (method_desc->method.
646 info_flags & ACPI_METHOD_SERIALIZED_PENDING) {
647 if (walk_state) {
648 ACPI_INFO((AE_INFO,
649 "Marking method %4.4s as Serialized because of AE_ALREADY_EXISTS error",
650 walk_state->method_node->name.
651 ascii));
652 }
653
654 /*
655 * Method tried to create an object twice and was marked as
656 * "pending serialized". The probable cause is that the method
657 * cannot handle reentrancy.
658 *
659 * The method was created as not_serialized, but it tried to create
660 * a named object and then blocked, causing the second thread
661 * entrance to begin and then fail. Workaround this problem by
662 * marking the method permanently as Serialized when the last
663 * thread exits here.
664 */
665 method_desc->method.info_flags &=
666 ~ACPI_METHOD_SERIALIZED_PENDING;
667 method_desc->method.info_flags |=
668 ACPI_METHOD_SERIALIZED;
669 method_desc->method.sync_level = 0;
670 }
671
672 /* No more threads, we can free the owner_id */
673
674 if (!
675 (method_desc->method.
676 info_flags & ACPI_METHOD_MODULE_LEVEL)) {
677 acpi_ut_release_owner_id(&method_desc->method.owner_id);
678 }
679 }
680
681 return_VOID;
682 }
683