1 /******************************************************************************
3 * Module Name: dsmethod - Parser/Interpreter interface - control method parsing
5 *****************************************************************************/
8 * Copyright (C) 2000 - 2006, R. Byron Moore
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/acparser.h>
46 #include <acpi/amlcode.h>
47 #include <acpi/acdispat.h>
48 #include <acpi/acinterp.h>
49 #include <acpi/acnamesp.h>
50 #include <acpi/acdisasm.h>
52 #define _COMPONENT ACPI_DISPATCHER
53 ACPI_MODULE_NAME("dsmethod")
55 /*******************************************************************************
57 * FUNCTION: acpi_ds_method_error
59 * PARAMETERS: Status - Execution status
60 * walk_state - Current state
64 * DESCRIPTION: Called on method error. Invoke the global exception handler if
65 * present, dump the method data if the disassembler is configured
67 * Note: Allows the exception handler to change the status code
69 ******************************************************************************/
71 acpi_ds_method_error(acpi_status status
, struct acpi_walk_state
*walk_state
)
73 ACPI_FUNCTION_ENTRY();
75 /* Ignore AE_OK and control exception codes */
77 if (ACPI_SUCCESS(status
) || (status
& AE_CODE_CONTROL
)) {
81 /* Invoke the global exception handler */
83 if (acpi_gbl_exception_handler
) {
84 /* Exit the interpreter, allow handler to execute methods */
86 acpi_ex_exit_interpreter();
89 * Handler can map the exception code to anything it wants, including
90 * AE_OK, in which case the executing method will not be aborted.
92 status
= acpi_gbl_exception_handler(status
,
93 walk_state
->method_node
?
94 walk_state
->method_node
->
97 walk_state
->aml_offset
,
99 (void)acpi_ex_enter_interpreter();
101 #ifdef ACPI_DISASSEMBLER
102 if (ACPI_FAILURE(status
)) {
103 /* Display method locals/args if disassembler is present */
105 acpi_dm_dump_method_info(status
, walk_state
, walk_state
->op
);
112 /*******************************************************************************
114 * FUNCTION: acpi_ds_begin_method_execution
116 * PARAMETERS: method_node - Node of the method
117 * obj_desc - The method object
118 * calling_method_node - Caller of this method (if non-null)
122 * DESCRIPTION: Prepare a method for execution. Parses the method if necessary,
123 * increments the thread count, and waits at the method semaphore
124 * for clearance to execute.
126 ******************************************************************************/
129 acpi_ds_begin_method_execution(struct acpi_namespace_node
* method_node
,
130 union acpi_operand_object
* obj_desc
,
131 struct acpi_namespace_node
* calling_method_node
)
133 acpi_status status
= AE_OK
;
135 ACPI_FUNCTION_TRACE_PTR("ds_begin_method_execution", method_node
);
138 return_ACPI_STATUS(AE_NULL_ENTRY
);
141 /* Prevent wraparound of thread count */
143 if (obj_desc
->method
.thread_count
== ACPI_UINT8_MAX
) {
144 ACPI_REPORT_ERROR(("Method reached maximum reentrancy limit (255)\n"));
145 return_ACPI_STATUS(AE_AML_METHOD_LIMIT
);
149 * If there is a concurrency limit on this method, we need to
150 * obtain a unit from the method semaphore.
152 if (obj_desc
->method
.semaphore
) {
154 * Allow recursive method calls, up to the reentrancy/concurrency
155 * limit imposed by the SERIALIZED rule and the sync_level method
158 * The point of this code is to avoid permanently blocking a
159 * thread that is making recursive method calls.
161 if (method_node
== calling_method_node
) {
162 if (obj_desc
->method
.thread_count
>=
163 obj_desc
->method
.concurrency
) {
164 return_ACPI_STATUS(AE_AML_METHOD_LIMIT
);
169 * Get a unit from the method semaphore. This releases the
170 * interpreter if we block
173 acpi_ex_system_wait_semaphore(obj_desc
->method
.semaphore
,
178 * Allocate an Owner ID for this method, only if this is the first thread
179 * to begin concurrent execution. We only need one owner_id, even if the
180 * method is invoked recursively.
182 if (!obj_desc
->method
.owner_id
) {
183 status
= acpi_ut_allocate_owner_id(&obj_desc
->method
.owner_id
);
184 if (ACPI_FAILURE(status
)) {
185 return_ACPI_STATUS(status
);
190 * Increment the method parse tree thread count since it has been
191 * reentered one more time (even if it is the same thread)
193 obj_desc
->method
.thread_count
++;
194 return_ACPI_STATUS(status
);
197 /*******************************************************************************
199 * FUNCTION: acpi_ds_call_control_method
201 * PARAMETERS: Thread - Info for this thread
202 * this_walk_state - Current walk state
203 * Op - Current Op to be walked
207 * DESCRIPTION: Transfer execution to a called control method
209 ******************************************************************************/
212 acpi_ds_call_control_method(struct acpi_thread_state
*thread
,
213 struct acpi_walk_state
*this_walk_state
,
214 union acpi_parse_object
*op
)
217 struct acpi_namespace_node
*method_node
;
218 struct acpi_walk_state
*next_walk_state
= NULL
;
219 union acpi_operand_object
*obj_desc
;
220 struct acpi_parameter_info info
;
223 ACPI_FUNCTION_TRACE_PTR("ds_call_control_method", this_walk_state
);
225 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH
,
226 "Execute method %p, currentstate=%p\n",
227 this_walk_state
->prev_op
, this_walk_state
));
230 * Get the namespace entry for the control method we are about to call
232 method_node
= this_walk_state
->method_call_node
;
234 return_ACPI_STATUS(AE_NULL_ENTRY
);
237 obj_desc
= acpi_ns_get_attached_object(method_node
);
239 return_ACPI_STATUS(AE_NULL_OBJECT
);
242 /* Init for new method, wait on concurrency semaphore */
244 status
= acpi_ds_begin_method_execution(method_node
, obj_desc
,
245 this_walk_state
->method_node
);
246 if (ACPI_FAILURE(status
)) {
250 if (!(obj_desc
->method
.method_flags
& AML_METHOD_INTERNAL_ONLY
)) {
251 /* 1) Parse: Create a new walk state for the preempting walk */
254 acpi_ds_create_walk_state(obj_desc
->method
.owner_id
, op
,
256 if (!next_walk_state
) {
257 return_ACPI_STATUS(AE_NO_MEMORY
);
260 /* Create and init a Root Node */
262 op
= acpi_ps_create_scope_op();
264 status
= AE_NO_MEMORY
;
268 status
= acpi_ds_init_aml_walk(next_walk_state
, op
, method_node
,
269 obj_desc
->method
.aml_start
,
270 obj_desc
->method
.aml_length
,
272 if (ACPI_FAILURE(status
)) {
273 acpi_ds_delete_walk_state(next_walk_state
);
277 /* Begin AML parse */
279 status
= acpi_ps_parse_aml(next_walk_state
);
280 acpi_ps_delete_parse_tree(op
);
283 /* 2) Execute: Create a new state for the preempting walk */
285 next_walk_state
= acpi_ds_create_walk_state(obj_desc
->method
.owner_id
,
286 NULL
, obj_desc
, thread
);
287 if (!next_walk_state
) {
288 status
= AE_NO_MEMORY
;
292 * The resolved arguments were put on the previous walk state's operand
293 * stack. Operands on the previous walk state stack always
294 * start at index 0. Also, null terminate the list of arguments
296 this_walk_state
->operands
[this_walk_state
->num_operands
] = NULL
;
298 info
.parameters
= &this_walk_state
->operands
[0];
299 info
.parameter_type
= ACPI_PARAM_ARGS
;
301 status
= acpi_ds_init_aml_walk(next_walk_state
, NULL
, method_node
,
302 obj_desc
->method
.aml_start
,
303 obj_desc
->method
.aml_length
, &info
, 3);
304 if (ACPI_FAILURE(status
)) {
309 * Delete the operands on the previous walkstate operand stack
310 * (they were copied to new objects)
312 for (i
= 0; i
< obj_desc
->method
.param_count
; i
++) {
313 acpi_ut_remove_reference(this_walk_state
->operands
[i
]);
314 this_walk_state
->operands
[i
] = NULL
;
317 /* Clear the operand stack */
319 this_walk_state
->num_operands
= 0;
321 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH
,
322 "Starting nested execution, newstate=%p\n",
325 if (obj_desc
->method
.method_flags
& AML_METHOD_INTERNAL_ONLY
) {
326 status
= obj_desc
->method
.implementation(next_walk_state
);
329 return_ACPI_STATUS(status
);
332 /* Decrement the thread count on the method parse tree */
334 if (next_walk_state
&& (next_walk_state
->method_desc
)) {
335 next_walk_state
->method_desc
->method
.thread_count
--;
338 /* On error, we must delete the new walk state */
340 acpi_ds_terminate_control_method(next_walk_state
);
341 acpi_ds_delete_walk_state(next_walk_state
);
342 return_ACPI_STATUS(status
);
345 /*******************************************************************************
347 * FUNCTION: acpi_ds_restart_control_method
349 * PARAMETERS: walk_state - State for preempted method (caller)
350 * return_desc - Return value from the called method
354 * DESCRIPTION: Restart a method that was preempted by another (nested) method
355 * invocation. Handle the return value (if any) from the callee.
357 ******************************************************************************/
360 acpi_ds_restart_control_method(struct acpi_walk_state
*walk_state
,
361 union acpi_operand_object
*return_desc
)
365 ACPI_FUNCTION_TRACE_PTR("ds_restart_control_method", walk_state
);
367 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH
,
368 "****Restart [%4.4s] Op %p return_value_from_callee %p\n",
369 (char *)&walk_state
->method_node
->name
,
370 walk_state
->method_call_op
, return_desc
));
372 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH
,
373 " return_from_this_method_used?=%X res_stack %p Walk %p\n",
374 walk_state
->return_used
,
375 walk_state
->results
, walk_state
));
377 /* Did the called method return a value? */
380 /* Are we actually going to use the return value? */
382 if (walk_state
->return_used
) {
383 /* Save the return value from the previous method */
385 status
= acpi_ds_result_push(return_desc
, walk_state
);
386 if (ACPI_FAILURE(status
)) {
387 acpi_ut_remove_reference(return_desc
);
388 return_ACPI_STATUS(status
);
392 * Save as THIS method's return value in case it is returned
393 * immediately to yet another method
395 walk_state
->return_desc
= return_desc
;
399 * The following code is the
400 * optional support for a so-called "implicit return". Some AML code
401 * assumes that the last value of the method is "implicitly" returned
402 * to the caller. Just save the last result as the return value.
403 * NOTE: this is optional because the ASL language does not actually
404 * support this behavior.
406 else if (!acpi_ds_do_implicit_return
407 (return_desc
, walk_state
, FALSE
)) {
409 * Delete the return value if it will not be used by the
412 acpi_ut_remove_reference(return_desc
);
416 return_ACPI_STATUS(AE_OK
);
419 /*******************************************************************************
421 * FUNCTION: acpi_ds_terminate_control_method
423 * PARAMETERS: walk_state - State of the method
427 * DESCRIPTION: Terminate a control method. Delete everything that the method
428 * created, delete all locals and arguments, and delete the parse
431 ******************************************************************************/
433 void acpi_ds_terminate_control_method(struct acpi_walk_state
*walk_state
)
435 union acpi_operand_object
*obj_desc
;
436 struct acpi_namespace_node
*method_node
;
439 ACPI_FUNCTION_TRACE_PTR("ds_terminate_control_method", walk_state
);
445 /* The current method object was saved in the walk state */
447 obj_desc
= walk_state
->method_desc
;
452 /* Delete all arguments and locals */
454 acpi_ds_method_data_delete_all(walk_state
);
457 * Lock the parser while we terminate this method.
458 * If this is the last thread executing the method,
459 * we have additional cleanup to perform
461 status
= acpi_ut_acquire_mutex(ACPI_MTX_PARSER
);
462 if (ACPI_FAILURE(status
)) {
466 /* Signal completion of the execution of this method if necessary */
468 if (walk_state
->method_desc
->method
.semaphore
) {
470 acpi_os_signal_semaphore(walk_state
->method_desc
->method
.
472 if (ACPI_FAILURE(status
)) {
473 ACPI_REPORT_ERROR(("Could not signal method semaphore\n"));
475 /* Ignore error and continue cleanup */
480 * There are no more threads executing this method. Perform
481 * additional cleanup.
483 * The method Node is stored in the walk state
485 method_node
= walk_state
->method_node
;
487 /* Lock namespace for possible update */
489 status
= acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE
);
490 if (ACPI_FAILURE(status
)) {
495 * Delete any namespace entries created immediately underneath
498 if (method_node
->child
) {
499 acpi_ns_delete_namespace_subtree(method_node
);
503 * Delete any namespace entries created anywhere else within
504 * the namespace by the execution of this method
506 acpi_ns_delete_namespace_by_owner(walk_state
->method_desc
->method
.
508 status
= acpi_ut_release_mutex(ACPI_MTX_NAMESPACE
);
510 /* Are there any other threads currently executing this method? */
512 if (walk_state
->method_desc
->method
.thread_count
) {
514 * Additional threads. Do not release the owner_id in this case,
515 * we immediately reuse it for the next thread executing this method
517 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH
,
518 "*** Completed execution of one thread, %d threads remaining\n",
519 walk_state
->method_desc
->method
.
522 /* This is the only executing thread for this method */
525 * Support to dynamically change a method from not_serialized to
526 * Serialized if it appears that the method is incorrectly written and
527 * does not support multiple thread execution. The best example of this
528 * is if such a method creates namespace objects and blocks. A second
529 * thread will fail with an AE_ALREADY_EXISTS exception
531 * This code is here because we must wait until the last thread exits
532 * before creating the synchronization semaphore.
534 if ((walk_state
->method_desc
->method
.concurrency
== 1) &&
535 (!walk_state
->method_desc
->method
.semaphore
)) {
536 status
= acpi_os_create_semaphore(1, 1,
542 /* No more threads, we can free the owner_id */
544 acpi_ut_release_owner_id(&walk_state
->method_desc
->method
.
549 (void)acpi_ut_release_mutex(ACPI_MTX_PARSER
);
553 #ifdef ACPI_INIT_PARSE_METHODS
555 * Note 11/2005: Removed this code to parse all methods during table
556 * load because it causes problems if there are any errors during the
557 * parse. Also, it seems like overkill and we probably don't want to
558 * abort a table load because of an issue with a single method.
561 /*******************************************************************************
563 * FUNCTION: acpi_ds_parse_method
565 * PARAMETERS: Node - Method node
569 * DESCRIPTION: Parse the AML that is associated with the method.
571 * MUTEX: Assumes parser is locked
573 ******************************************************************************/
575 acpi_status
acpi_ds_parse_method(struct acpi_namespace_node
*node
)
578 union acpi_operand_object
*obj_desc
;
579 union acpi_parse_object
*op
;
580 struct acpi_walk_state
*walk_state
;
582 ACPI_FUNCTION_TRACE_PTR("ds_parse_method", node
);
584 /* Parameter Validation */
587 return_ACPI_STATUS(AE_NULL_ENTRY
);
590 ACPI_DEBUG_PRINT((ACPI_DB_PARSE
,
591 "**** Parsing [%4.4s] **** named_obj=%p\n",
592 acpi_ut_get_node_name(node
), node
));
594 /* Extract the method object from the method Node */
596 obj_desc
= acpi_ns_get_attached_object(node
);
598 return_ACPI_STATUS(AE_NULL_OBJECT
);
601 /* Create a mutex for the method if there is a concurrency limit */
603 if ((obj_desc
->method
.concurrency
!= ACPI_INFINITE_CONCURRENCY
) &&
604 (!obj_desc
->method
.semaphore
)) {
605 status
= acpi_os_create_semaphore(obj_desc
->method
.concurrency
,
606 obj_desc
->method
.concurrency
,
607 &obj_desc
->method
.semaphore
);
608 if (ACPI_FAILURE(status
)) {
609 return_ACPI_STATUS(status
);
614 * Allocate a new parser op to be the root of the parsed
617 op
= acpi_ps_alloc_op(AML_METHOD_OP
);
619 return_ACPI_STATUS(AE_NO_MEMORY
);
622 /* Init new op with the method name and pointer back to the Node */
624 acpi_ps_set_name(op
, node
->name
.integer
);
625 op
->common
.node
= node
;
628 * Get a new owner_id for objects created by this method. Namespace
629 * objects (such as Operation Regions) can be created during the
632 status
= acpi_ut_allocate_owner_id(&obj_desc
->method
.owner_id
);
633 if (ACPI_FAILURE(status
)) {
637 /* Create and initialize a new walk state */
640 acpi_ds_create_walk_state(obj_desc
->method
.owner_id
, NULL
, NULL
,
643 status
= AE_NO_MEMORY
;
647 status
= acpi_ds_init_aml_walk(walk_state
, op
, node
,
648 obj_desc
->method
.aml_start
,
649 obj_desc
->method
.aml_length
, NULL
, 1);
650 if (ACPI_FAILURE(status
)) {
651 acpi_ds_delete_walk_state(walk_state
);
656 * Parse the method, first pass
658 * The first pass load is where newly declared named objects are added into
659 * the namespace. Actual evaluation of the named objects (what would be
660 * called a "second pass") happens during the actual execution of the
661 * method so that operands to the named objects can take on dynamic
664 status
= acpi_ps_parse_aml(walk_state
);
665 if (ACPI_FAILURE(status
)) {
669 ACPI_DEBUG_PRINT((ACPI_DB_PARSE
,
670 "**** [%4.4s] Parsed **** named_obj=%p Op=%p\n",
671 acpi_ut_get_node_name(node
), node
, op
));
674 * Delete the parse tree. We simply re-parse the method for every
675 * execution since there isn't much overhead (compared to keeping lots
676 * of parse trees around)
678 acpi_ns_delete_namespace_subtree(node
);
679 acpi_ns_delete_namespace_by_owner(obj_desc
->method
.owner_id
);
682 acpi_ut_release_owner_id(&obj_desc
->method
.owner_id
);
685 acpi_ps_delete_parse_tree(op
);
686 return_ACPI_STATUS(status
);