1 /******************************************************************************
3 * Module Name: dsmethod - Parser/Interpreter interface - control method parsing
5 *****************************************************************************/
8 * Copyright (C) 2000 - 2008, Intel Corp.
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions, and the following disclaimer,
16 * without modification.
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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.
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.
31 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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33 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
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44 #include <acpi/acpi.h>
45 #include <acpi/amlcode.h>
46 #include <acpi/acdispat.h>
47 #include <acpi/acinterp.h>
48 #include <acpi/acnamesp.h>
49 #include <acpi/acdisasm.h>
51 #define _COMPONENT ACPI_DISPATCHER
52 ACPI_MODULE_NAME("dsmethod")
54 /* Local prototypes */
56 acpi_ds_create_method_mutex(union acpi_operand_object
*method_desc
);
58 /*******************************************************************************
60 * FUNCTION: acpi_ds_method_error
62 * PARAMETERS: Status - Execution status
63 * walk_state - Current state
67 * DESCRIPTION: Called on method error. Invoke the global exception handler if
68 * present, dump the method data if the disassembler is configured
70 * Note: Allows the exception handler to change the status code
72 ******************************************************************************/
75 acpi_ds_method_error(acpi_status status
, struct acpi_walk_state
*walk_state
)
77 ACPI_FUNCTION_ENTRY();
79 /* Ignore AE_OK and control exception codes */
81 if (ACPI_SUCCESS(status
) || (status
& AE_CODE_CONTROL
)) {
85 /* Invoke the global exception handler */
87 if (acpi_gbl_exception_handler
) {
89 /* Exit the interpreter, allow handler to execute methods */
91 acpi_ex_exit_interpreter();
94 * Handler can map the exception code to anything it wants, including
95 * AE_OK, in which case the executing method will not be aborted.
97 status
= acpi_gbl_exception_handler(status
,
98 walk_state
->method_node
?
99 walk_state
->method_node
->
102 walk_state
->aml_offset
,
104 acpi_ex_enter_interpreter();
107 acpi_ds_clear_implicit_return(walk_state
);
109 #ifdef ACPI_DISASSEMBLER
110 if (ACPI_FAILURE(status
)) {
112 /* Display method locals/args if disassembler is present */
114 acpi_dm_dump_method_info(status
, walk_state
, walk_state
->op
);
121 /*******************************************************************************
123 * FUNCTION: acpi_ds_create_method_mutex
125 * PARAMETERS: obj_desc - The method object
129 * DESCRIPTION: Create a mutex object for a serialized control method
131 ******************************************************************************/
134 acpi_ds_create_method_mutex(union acpi_operand_object
*method_desc
)
136 union acpi_operand_object
*mutex_desc
;
139 ACPI_FUNCTION_TRACE(ds_create_method_mutex
);
141 /* Create the new mutex object */
143 mutex_desc
= acpi_ut_create_internal_object(ACPI_TYPE_MUTEX
);
145 return_ACPI_STATUS(AE_NO_MEMORY
);
148 /* Create the actual OS Mutex */
150 status
= acpi_os_create_mutex(&mutex_desc
->mutex
.os_mutex
);
151 if (ACPI_FAILURE(status
)) {
152 return_ACPI_STATUS(status
);
155 mutex_desc
->mutex
.sync_level
= method_desc
->method
.sync_level
;
156 method_desc
->method
.mutex
= mutex_desc
;
157 return_ACPI_STATUS(AE_OK
);
160 /*******************************************************************************
162 * FUNCTION: acpi_ds_begin_method_execution
164 * PARAMETERS: method_node - Node of the method
165 * obj_desc - The method object
166 * walk_state - current state, NULL if not yet executing
171 * DESCRIPTION: Prepare a method for execution. Parses the method if necessary,
172 * increments the thread count, and waits at the method semaphore
173 * for clearance to execute.
175 ******************************************************************************/
178 acpi_ds_begin_method_execution(struct acpi_namespace_node
*method_node
,
179 union acpi_operand_object
*obj_desc
,
180 struct acpi_walk_state
*walk_state
)
182 acpi_status status
= AE_OK
;
184 ACPI_FUNCTION_TRACE_PTR(ds_begin_method_execution
, method_node
);
187 return_ACPI_STATUS(AE_NULL_ENTRY
);
190 /* Prevent wraparound of thread count */
192 if (obj_desc
->method
.thread_count
== ACPI_UINT8_MAX
) {
194 "Method reached maximum reentrancy limit (255)"));
195 return_ACPI_STATUS(AE_AML_METHOD_LIMIT
);
199 * If this method is serialized, we need to acquire the method mutex.
201 if (obj_desc
->method
.method_flags
& AML_METHOD_SERIALIZED
) {
203 * Create a mutex for the method if it is defined to be Serialized
204 * and a mutex has not already been created. We defer the mutex creation
205 * until a method is actually executed, to minimize the object count
207 if (!obj_desc
->method
.mutex
) {
208 status
= acpi_ds_create_method_mutex(obj_desc
);
209 if (ACPI_FAILURE(status
)) {
210 return_ACPI_STATUS(status
);
215 * The current_sync_level (per-thread) must be less than or equal to
216 * the sync level of the method. This mechanism provides some
217 * deadlock prevention
219 * Top-level method invocation has no walk state at this point
222 (walk_state
->thread
->current_sync_level
>
223 obj_desc
->method
.mutex
->mutex
.sync_level
)) {
225 "Cannot acquire Mutex for method [%4.4s], current SyncLevel is too large (%d)",
226 acpi_ut_get_node_name(method_node
),
227 walk_state
->thread
->current_sync_level
));
229 return_ACPI_STATUS(AE_AML_MUTEX_ORDER
);
233 * Obtain the method mutex if necessary. Do not acquire mutex for a
237 !obj_desc
->method
.mutex
->mutex
.thread_id
||
238 (walk_state
->thread
->thread_id
!=
239 obj_desc
->method
.mutex
->mutex
.thread_id
)) {
241 * Acquire the method mutex. This releases the interpreter if we
242 * block (and reacquires it before it returns)
245 acpi_ex_system_wait_mutex(obj_desc
->method
.mutex
->
248 if (ACPI_FAILURE(status
)) {
249 return_ACPI_STATUS(status
);
252 /* Update the mutex and walk info and save the original sync_level */
255 obj_desc
->method
.mutex
->mutex
.
256 original_sync_level
=
257 walk_state
->thread
->current_sync_level
;
259 obj_desc
->method
.mutex
->mutex
.thread_id
=
260 walk_state
->thread
->thread_id
;
261 walk_state
->thread
->current_sync_level
=
262 obj_desc
->method
.sync_level
;
264 obj_desc
->method
.mutex
->mutex
.
265 original_sync_level
=
266 obj_desc
->method
.mutex
->mutex
.sync_level
;
270 /* Always increase acquisition depth */
272 obj_desc
->method
.mutex
->mutex
.acquisition_depth
++;
276 * Allocate an Owner ID for this method, only if this is the first thread
277 * to begin concurrent execution. We only need one owner_id, even if the
278 * method is invoked recursively.
280 if (!obj_desc
->method
.owner_id
) {
281 status
= acpi_ut_allocate_owner_id(&obj_desc
->method
.owner_id
);
282 if (ACPI_FAILURE(status
)) {
288 * Increment the method parse tree thread count since it has been
289 * reentered one more time (even if it is the same thread)
291 obj_desc
->method
.thread_count
++;
292 return_ACPI_STATUS(status
);
295 /* On error, must release the method mutex (if present) */
297 if (obj_desc
->method
.mutex
) {
298 acpi_os_release_mutex(obj_desc
->method
.mutex
->mutex
.os_mutex
);
300 return_ACPI_STATUS(status
);
303 /*******************************************************************************
305 * FUNCTION: acpi_ds_call_control_method
307 * PARAMETERS: Thread - Info for this thread
308 * this_walk_state - Current walk state
309 * Op - Current Op to be walked
313 * DESCRIPTION: Transfer execution to a called control method
315 ******************************************************************************/
318 acpi_ds_call_control_method(struct acpi_thread_state
*thread
,
319 struct acpi_walk_state
*this_walk_state
,
320 union acpi_parse_object
*op
)
323 struct acpi_namespace_node
*method_node
;
324 struct acpi_walk_state
*next_walk_state
= NULL
;
325 union acpi_operand_object
*obj_desc
;
326 struct acpi_evaluate_info
*info
;
329 ACPI_FUNCTION_TRACE_PTR(ds_call_control_method
, this_walk_state
);
331 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH
,
332 "Calling method %p, currentstate=%p\n",
333 this_walk_state
->prev_op
, this_walk_state
));
336 * Get the namespace entry for the control method we are about to call
338 method_node
= this_walk_state
->method_call_node
;
340 return_ACPI_STATUS(AE_NULL_ENTRY
);
343 obj_desc
= acpi_ns_get_attached_object(method_node
);
345 return_ACPI_STATUS(AE_NULL_OBJECT
);
348 /* Init for new method, possibly wait on method mutex */
350 status
= acpi_ds_begin_method_execution(method_node
, obj_desc
,
352 if (ACPI_FAILURE(status
)) {
353 return_ACPI_STATUS(status
);
356 /* Begin method parse/execution. Create a new walk state */
358 next_walk_state
= acpi_ds_create_walk_state(obj_desc
->method
.owner_id
,
359 NULL
, obj_desc
, thread
);
360 if (!next_walk_state
) {
361 status
= AE_NO_MEMORY
;
366 * The resolved arguments were put on the previous walk state's operand
367 * stack. Operands on the previous walk state stack always
368 * start at index 0. Also, null terminate the list of arguments
370 this_walk_state
->operands
[this_walk_state
->num_operands
] = NULL
;
373 * Allocate and initialize the evaluation information block
374 * TBD: this is somewhat inefficient, should change interface to
375 * ds_init_aml_walk. For now, keeps this struct off the CPU stack
377 info
= ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info
));
379 return_ACPI_STATUS(AE_NO_MEMORY
);
382 info
->parameters
= &this_walk_state
->operands
[0];
384 status
= acpi_ds_init_aml_walk(next_walk_state
, NULL
, method_node
,
385 obj_desc
->method
.aml_start
,
386 obj_desc
->method
.aml_length
, info
,
390 if (ACPI_FAILURE(status
)) {
395 * Delete the operands on the previous walkstate operand stack
396 * (they were copied to new objects)
398 for (i
= 0; i
< obj_desc
->method
.param_count
; i
++) {
399 acpi_ut_remove_reference(this_walk_state
->operands
[i
]);
400 this_walk_state
->operands
[i
] = NULL
;
403 /* Clear the operand stack */
405 this_walk_state
->num_operands
= 0;
407 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH
,
408 "**** Begin nested execution of [%4.4s] **** WalkState=%p\n",
409 method_node
->name
.ascii
, next_walk_state
));
411 /* Invoke an internal method if necessary */
413 if (obj_desc
->method
.method_flags
& AML_METHOD_INTERNAL_ONLY
) {
414 status
= obj_desc
->method
.implementation(next_walk_state
);
415 if (status
== AE_OK
) {
416 status
= AE_CTRL_TERMINATE
;
420 return_ACPI_STATUS(status
);
424 /* On error, we must terminate the method properly */
426 acpi_ds_terminate_control_method(obj_desc
, next_walk_state
);
427 if (next_walk_state
) {
428 acpi_ds_delete_walk_state(next_walk_state
);
431 return_ACPI_STATUS(status
);
434 /*******************************************************************************
436 * FUNCTION: acpi_ds_restart_control_method
438 * PARAMETERS: walk_state - State for preempted method (caller)
439 * return_desc - Return value from the called method
443 * DESCRIPTION: Restart a method that was preempted by another (nested) method
444 * invocation. Handle the return value (if any) from the callee.
446 ******************************************************************************/
449 acpi_ds_restart_control_method(struct acpi_walk_state
*walk_state
,
450 union acpi_operand_object
*return_desc
)
453 int same_as_implicit_return
;
455 ACPI_FUNCTION_TRACE_PTR(ds_restart_control_method
, walk_state
);
457 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH
,
458 "****Restart [%4.4s] Op %p ReturnValueFromCallee %p\n",
459 acpi_ut_get_node_name(walk_state
->method_node
),
460 walk_state
->method_call_op
, return_desc
));
462 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH
,
463 " ReturnFromThisMethodUsed?=%X ResStack %p Walk %p\n",
464 walk_state
->return_used
,
465 walk_state
->results
, walk_state
));
467 /* Did the called method return a value? */
471 /* Is the implicit return object the same as the return desc? */
473 same_as_implicit_return
=
474 (walk_state
->implicit_return_obj
== return_desc
);
476 /* Are we actually going to use the return value? */
478 if (walk_state
->return_used
) {
480 /* Save the return value from the previous method */
482 status
= acpi_ds_result_push(return_desc
, walk_state
);
483 if (ACPI_FAILURE(status
)) {
484 acpi_ut_remove_reference(return_desc
);
485 return_ACPI_STATUS(status
);
489 * Save as THIS method's return value in case it is returned
490 * immediately to yet another method
492 walk_state
->return_desc
= return_desc
;
496 * The following code is the optional support for the so-called
497 * "implicit return". Some AML code assumes that the last value of the
498 * method is "implicitly" returned to the caller, in the absence of an
499 * explicit return value.
501 * Just save the last result of the method as the return value.
503 * NOTE: this is optional because the ASL language does not actually
504 * support this behavior.
506 else if (!acpi_ds_do_implicit_return
507 (return_desc
, walk_state
, FALSE
)
508 || same_as_implicit_return
) {
510 * Delete the return value if it will not be used by the
511 * calling method or remove one reference if the explicit return
512 * is the same as the implicit return value.
514 acpi_ut_remove_reference(return_desc
);
518 return_ACPI_STATUS(AE_OK
);
521 /*******************************************************************************
523 * FUNCTION: acpi_ds_terminate_control_method
525 * PARAMETERS: method_desc - Method object
526 * walk_state - State associated with the method
530 * DESCRIPTION: Terminate a control method. Delete everything that the method
531 * created, delete all locals and arguments, and delete the parse
534 * MUTEX: Interpreter is locked
536 ******************************************************************************/
539 acpi_ds_terminate_control_method(union acpi_operand_object
*method_desc
,
540 struct acpi_walk_state
*walk_state
)
543 ACPI_FUNCTION_TRACE_PTR(ds_terminate_control_method
, walk_state
);
545 /* method_desc is required, walk_state is optional */
553 /* Delete all arguments and locals */
555 acpi_ds_method_data_delete_all(walk_state
);
558 * If method is serialized, release the mutex and restore the
559 * current sync level for this thread
561 if (method_desc
->method
.mutex
) {
563 /* Acquisition Depth handles recursive calls */
565 method_desc
->method
.mutex
->mutex
.acquisition_depth
--;
566 if (!method_desc
->method
.mutex
->mutex
.acquisition_depth
) {
567 walk_state
->thread
->current_sync_level
=
568 method_desc
->method
.mutex
->mutex
.
571 acpi_os_release_mutex(method_desc
->method
.
572 mutex
->mutex
.os_mutex
);
573 method_desc
->method
.mutex
->mutex
.thread_id
= NULL
;
578 * Delete any namespace objects created anywhere within
579 * the namespace by the execution of this method
581 acpi_ns_delete_namespace_by_owner(method_desc
->method
.owner_id
);
584 /* Decrement the thread count on the method */
586 if (method_desc
->method
.thread_count
) {
587 method_desc
->method
.thread_count
--;
589 ACPI_ERROR((AE_INFO
, "Invalid zero thread count in method"));
592 /* Are there any other threads currently executing this method? */
594 if (method_desc
->method
.thread_count
) {
596 * Additional threads. Do not release the owner_id in this case,
597 * we immediately reuse it for the next thread executing this method
599 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH
,
600 "*** Completed execution of one thread, %d threads remaining\n",
601 method_desc
->method
.thread_count
));
603 /* This is the only executing thread for this method */
606 * Support to dynamically change a method from not_serialized to
607 * Serialized if it appears that the method is incorrectly written and
608 * does not support multiple thread execution. The best example of this
609 * is if such a method creates namespace objects and blocks. A second
610 * thread will fail with an AE_ALREADY_EXISTS exception
612 * This code is here because we must wait until the last thread exits
613 * before creating the synchronization semaphore.
615 if ((method_desc
->method
.method_flags
& AML_METHOD_SERIALIZED
)
616 && (!method_desc
->method
.mutex
)) {
617 (void)acpi_ds_create_method_mutex(method_desc
);
620 /* No more threads, we can free the owner_id */
622 acpi_ut_release_owner_id(&method_desc
->method
.owner_id
);