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.
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.
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
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.
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();
106 #ifdef ACPI_DISASSEMBLER
107 if (ACPI_FAILURE(status
)) {
109 /* Display method locals/args if disassembler is present */
111 acpi_dm_dump_method_info(status
, walk_state
, walk_state
->op
);
118 /*******************************************************************************
120 * FUNCTION: acpi_ds_create_method_mutex
122 * PARAMETERS: obj_desc - The method object
126 * DESCRIPTION: Create a mutex object for a serialized control method
128 ******************************************************************************/
131 acpi_ds_create_method_mutex(union acpi_operand_object
*method_desc
)
133 union acpi_operand_object
*mutex_desc
;
136 ACPI_FUNCTION_TRACE(ds_create_method_mutex
);
138 /* Create the new mutex object */
140 mutex_desc
= acpi_ut_create_internal_object(ACPI_TYPE_MUTEX
);
142 return_ACPI_STATUS(AE_NO_MEMORY
);
145 /* Create the actual OS Mutex */
147 status
= acpi_os_create_mutex(&mutex_desc
->mutex
.os_mutex
);
148 if (ACPI_FAILURE(status
)) {
149 return_ACPI_STATUS(status
);
152 mutex_desc
->mutex
.sync_level
= method_desc
->method
.sync_level
;
153 method_desc
->method
.mutex
= mutex_desc
;
154 return_ACPI_STATUS(AE_OK
);
157 /*******************************************************************************
159 * FUNCTION: acpi_ds_begin_method_execution
161 * PARAMETERS: method_node - Node of the method
162 * obj_desc - The method object
163 * walk_state - current state, NULL if not yet executing
168 * DESCRIPTION: Prepare a method for execution. Parses the method if necessary,
169 * increments the thread count, and waits at the method semaphore
170 * for clearance to execute.
172 ******************************************************************************/
175 acpi_ds_begin_method_execution(struct acpi_namespace_node
*method_node
,
176 union acpi_operand_object
*obj_desc
,
177 struct acpi_walk_state
*walk_state
)
179 acpi_status status
= AE_OK
;
181 ACPI_FUNCTION_TRACE_PTR(ds_begin_method_execution
, method_node
);
184 return_ACPI_STATUS(AE_NULL_ENTRY
);
187 /* Prevent wraparound of thread count */
189 if (obj_desc
->method
.thread_count
== ACPI_UINT8_MAX
) {
191 "Method reached maximum reentrancy limit (255)"));
192 return_ACPI_STATUS(AE_AML_METHOD_LIMIT
);
196 * If this method is serialized, we need to acquire the method mutex.
198 if (obj_desc
->method
.method_flags
& AML_METHOD_SERIALIZED
) {
200 * Create a mutex for the method if it is defined to be Serialized
201 * and a mutex has not already been created. We defer the mutex creation
202 * until a method is actually executed, to minimize the object count
204 if (!obj_desc
->method
.mutex
) {
205 status
= acpi_ds_create_method_mutex(obj_desc
);
206 if (ACPI_FAILURE(status
)) {
207 return_ACPI_STATUS(status
);
212 * The current_sync_level (per-thread) must be less than or equal to
213 * the sync level of the method. This mechanism provides some
214 * deadlock prevention
216 * Top-level method invocation has no walk state at this point
219 (walk_state
->thread
->current_sync_level
>
220 obj_desc
->method
.mutex
->mutex
.sync_level
)) {
222 "Cannot acquire Mutex for method [%4.4s], current SyncLevel is too large (%d)",
223 acpi_ut_get_node_name(method_node
),
224 walk_state
->thread
->current_sync_level
));
226 return_ACPI_STATUS(AE_AML_MUTEX_ORDER
);
230 * Obtain the method mutex if necessary. Do not acquire mutex for a
234 !obj_desc
->method
.mutex
->mutex
.thread_id
||
235 (walk_state
->thread
->thread_id
!=
236 obj_desc
->method
.mutex
->mutex
.thread_id
)) {
238 * Acquire the method mutex. This releases the interpreter if we
239 * block (and reacquires it before it returns)
242 acpi_ex_system_wait_mutex(obj_desc
->method
.mutex
->
245 if (ACPI_FAILURE(status
)) {
246 return_ACPI_STATUS(status
);
249 /* Update the mutex and walk info and save the original sync_level */
252 obj_desc
->method
.mutex
->mutex
.
253 original_sync_level
=
254 walk_state
->thread
->current_sync_level
;
256 obj_desc
->method
.mutex
->mutex
.thread_id
=
257 walk_state
->thread
->thread_id
;
258 walk_state
->thread
->current_sync_level
=
259 obj_desc
->method
.sync_level
;
261 obj_desc
->method
.mutex
->mutex
.
262 original_sync_level
=
263 obj_desc
->method
.mutex
->mutex
.sync_level
;
267 /* Always increase acquisition depth */
269 obj_desc
->method
.mutex
->mutex
.acquisition_depth
++;
273 * Allocate an Owner ID for this method, only if this is the first thread
274 * to begin concurrent execution. We only need one owner_id, even if the
275 * method is invoked recursively.
277 if (!obj_desc
->method
.owner_id
) {
278 status
= acpi_ut_allocate_owner_id(&obj_desc
->method
.owner_id
);
279 if (ACPI_FAILURE(status
)) {
285 * Increment the method parse tree thread count since it has been
286 * reentered one more time (even if it is the same thread)
288 obj_desc
->method
.thread_count
++;
289 return_ACPI_STATUS(status
);
292 /* On error, must release the method mutex (if present) */
294 if (obj_desc
->method
.mutex
) {
295 acpi_os_release_mutex(obj_desc
->method
.mutex
->mutex
.os_mutex
);
297 return_ACPI_STATUS(status
);
300 /*******************************************************************************
302 * FUNCTION: acpi_ds_call_control_method
304 * PARAMETERS: Thread - Info for this thread
305 * this_walk_state - Current walk state
306 * Op - Current Op to be walked
310 * DESCRIPTION: Transfer execution to a called control method
312 ******************************************************************************/
315 acpi_ds_call_control_method(struct acpi_thread_state
*thread
,
316 struct acpi_walk_state
*this_walk_state
,
317 union acpi_parse_object
*op
)
320 struct acpi_namespace_node
*method_node
;
321 struct acpi_walk_state
*next_walk_state
= NULL
;
322 union acpi_operand_object
*obj_desc
;
323 struct acpi_evaluate_info
*info
;
326 ACPI_FUNCTION_TRACE_PTR(ds_call_control_method
, this_walk_state
);
328 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH
,
329 "Calling method %p, currentstate=%p\n",
330 this_walk_state
->prev_op
, this_walk_state
));
333 * Get the namespace entry for the control method we are about to call
335 method_node
= this_walk_state
->method_call_node
;
337 return_ACPI_STATUS(AE_NULL_ENTRY
);
340 obj_desc
= acpi_ns_get_attached_object(method_node
);
342 return_ACPI_STATUS(AE_NULL_OBJECT
);
345 /* Init for new method, possibly wait on method mutex */
347 status
= acpi_ds_begin_method_execution(method_node
, obj_desc
,
349 if (ACPI_FAILURE(status
)) {
350 return_ACPI_STATUS(status
);
353 /* Begin method parse/execution. Create a new walk state */
355 next_walk_state
= acpi_ds_create_walk_state(obj_desc
->method
.owner_id
,
356 NULL
, obj_desc
, thread
);
357 if (!next_walk_state
) {
358 status
= AE_NO_MEMORY
;
363 * The resolved arguments were put on the previous walk state's operand
364 * stack. Operands on the previous walk state stack always
365 * start at index 0. Also, null terminate the list of arguments
367 this_walk_state
->operands
[this_walk_state
->num_operands
] = NULL
;
370 * Allocate and initialize the evaluation information block
371 * TBD: this is somewhat inefficient, should change interface to
372 * ds_init_aml_walk. For now, keeps this struct off the CPU stack
374 info
= ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info
));
376 return_ACPI_STATUS(AE_NO_MEMORY
);
379 info
->parameters
= &this_walk_state
->operands
[0];
380 info
->parameter_type
= ACPI_PARAM_ARGS
;
382 status
= acpi_ds_init_aml_walk(next_walk_state
, NULL
, method_node
,
383 obj_desc
->method
.aml_start
,
384 obj_desc
->method
.aml_length
, info
,
388 if (ACPI_FAILURE(status
)) {
393 * Delete the operands on the previous walkstate operand stack
394 * (they were copied to new objects)
396 for (i
= 0; i
< obj_desc
->method
.param_count
; i
++) {
397 acpi_ut_remove_reference(this_walk_state
->operands
[i
]);
398 this_walk_state
->operands
[i
] = NULL
;
401 /* Clear the operand stack */
403 this_walk_state
->num_operands
= 0;
405 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH
,
406 "**** Begin nested execution of [%4.4s] **** WalkState=%p\n",
407 method_node
->name
.ascii
, next_walk_state
));
409 /* Invoke an internal method if necessary */
411 if (obj_desc
->method
.method_flags
& AML_METHOD_INTERNAL_ONLY
) {
412 status
= obj_desc
->method
.implementation(next_walk_state
);
415 return_ACPI_STATUS(status
);
419 /* On error, we must terminate the method properly */
421 acpi_ds_terminate_control_method(obj_desc
, next_walk_state
);
422 if (next_walk_state
) {
423 acpi_ds_delete_walk_state(next_walk_state
);
426 return_ACPI_STATUS(status
);
429 /*******************************************************************************
431 * FUNCTION: acpi_ds_restart_control_method
433 * PARAMETERS: walk_state - State for preempted method (caller)
434 * return_desc - Return value from the called method
438 * DESCRIPTION: Restart a method that was preempted by another (nested) method
439 * invocation. Handle the return value (if any) from the callee.
441 ******************************************************************************/
444 acpi_ds_restart_control_method(struct acpi_walk_state
*walk_state
,
445 union acpi_operand_object
*return_desc
)
448 int same_as_implicit_return
;
450 ACPI_FUNCTION_TRACE_PTR(ds_restart_control_method
, walk_state
);
452 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH
,
453 "****Restart [%4.4s] Op %p ReturnValueFromCallee %p\n",
454 acpi_ut_get_node_name(walk_state
->method_node
),
455 walk_state
->method_call_op
, return_desc
));
457 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH
,
458 " ReturnFromThisMethodUsed?=%X ResStack %p Walk %p\n",
459 walk_state
->return_used
,
460 walk_state
->results
, walk_state
));
462 /* Did the called method return a value? */
466 /* Is the implicit return object the same as the return desc? */
468 same_as_implicit_return
=
469 (walk_state
->implicit_return_obj
== return_desc
);
471 /* Are we actually going to use the return value? */
473 if (walk_state
->return_used
) {
475 /* Save the return value from the previous method */
477 status
= acpi_ds_result_push(return_desc
, walk_state
);
478 if (ACPI_FAILURE(status
)) {
479 acpi_ut_remove_reference(return_desc
);
480 return_ACPI_STATUS(status
);
484 * Save as THIS method's return value in case it is returned
485 * immediately to yet another method
487 walk_state
->return_desc
= return_desc
;
491 * The following code is the optional support for the so-called
492 * "implicit return". Some AML code assumes that the last value of the
493 * method is "implicitly" returned to the caller, in the absence of an
494 * explicit return value.
496 * Just save the last result of the method as the return value.
498 * NOTE: this is optional because the ASL language does not actually
499 * support this behavior.
501 else if (!acpi_ds_do_implicit_return
502 (return_desc
, walk_state
, FALSE
)
503 || same_as_implicit_return
) {
505 * Delete the return value if it will not be used by the
506 * calling method or remove one reference if the explicit return
507 * is the same as the implicit return value.
509 acpi_ut_remove_reference(return_desc
);
513 return_ACPI_STATUS(AE_OK
);
516 /*******************************************************************************
518 * FUNCTION: acpi_ds_terminate_control_method
520 * PARAMETERS: method_desc - Method object
521 * walk_state - State associated with the method
525 * DESCRIPTION: Terminate a control method. Delete everything that the method
526 * created, delete all locals and arguments, and delete the parse
529 * MUTEX: Interpreter is locked
531 ******************************************************************************/
534 acpi_ds_terminate_control_method(union acpi_operand_object
*method_desc
,
535 struct acpi_walk_state
*walk_state
)
538 ACPI_FUNCTION_TRACE_PTR(ds_terminate_control_method
, walk_state
);
540 /* method_desc is required, walk_state is optional */
548 /* Delete all arguments and locals */
550 acpi_ds_method_data_delete_all(walk_state
);
553 * If method is serialized, release the mutex and restore the
554 * current sync level for this thread
556 if (method_desc
->method
.mutex
) {
558 /* Acquisition Depth handles recursive calls */
560 method_desc
->method
.mutex
->mutex
.acquisition_depth
--;
561 if (!method_desc
->method
.mutex
->mutex
.acquisition_depth
) {
562 walk_state
->thread
->current_sync_level
=
563 method_desc
->method
.mutex
->mutex
.
566 acpi_os_release_mutex(method_desc
->method
.
567 mutex
->mutex
.os_mutex
);
568 method_desc
->method
.mutex
->mutex
.thread_id
= NULL
;
573 * Delete any namespace objects created anywhere within
574 * the namespace by the execution of this method
576 acpi_ns_delete_namespace_by_owner(method_desc
->method
.owner_id
);
579 /* Decrement the thread count on the method */
581 if (method_desc
->method
.thread_count
) {
582 method_desc
->method
.thread_count
--;
584 ACPI_ERROR((AE_INFO
, "Invalid zero thread count in method"));
587 /* Are there any other threads currently executing this method? */
589 if (method_desc
->method
.thread_count
) {
591 * Additional threads. Do not release the owner_id in this case,
592 * we immediately reuse it for the next thread executing this method
594 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH
,
595 "*** Completed execution of one thread, %d threads remaining\n",
596 method_desc
->method
.thread_count
));
598 /* This is the only executing thread for this method */
601 * Support to dynamically change a method from not_serialized to
602 * Serialized if it appears that the method is incorrectly written and
603 * does not support multiple thread execution. The best example of this
604 * is if such a method creates namespace objects and blocks. A second
605 * thread will fail with an AE_ALREADY_EXISTS exception
607 * This code is here because we must wait until the last thread exits
608 * before creating the synchronization semaphore.
610 if ((method_desc
->method
.method_flags
& AML_METHOD_SERIALIZED
)
611 && (!method_desc
->method
.mutex
)) {
612 (void)acpi_ds_create_method_mutex(method_desc
);
615 /* No more threads, we can free the owner_id */
617 acpi_ut_release_owner_id(&method_desc
->method
.owner_id
);