1 /******************************************************************************
3 * Module Name: dsmethod - Parser/Interpreter interface - control method parsing
5 *****************************************************************************/
8 * Copyright (C) 2000 - 2005, 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
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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>
51 #define _COMPONENT ACPI_DISPATCHER
52 ACPI_MODULE_NAME("dsmethod")
54 /*******************************************************************************
56 * FUNCTION: acpi_ds_parse_method
58 * PARAMETERS: Node - Method node
62 * DESCRIPTION: Parse the AML that is associated with the method.
64 * MUTEX: Assumes parser is locked
66 ******************************************************************************/
67 acpi_status
acpi_ds_parse_method(struct acpi_namespace_node
*node
)
70 union acpi_operand_object
*obj_desc
;
71 union acpi_parse_object
*op
;
72 struct acpi_walk_state
*walk_state
;
74 ACPI_FUNCTION_TRACE_PTR("ds_parse_method", node
);
76 /* Parameter Validation */
79 return_ACPI_STATUS(AE_NULL_ENTRY
);
82 ACPI_DEBUG_PRINT((ACPI_DB_PARSE
,
83 "**** Parsing [%4.4s] **** named_obj=%p\n",
84 acpi_ut_get_node_name(node
), node
));
86 /* Extract the method object from the method Node */
88 obj_desc
= acpi_ns_get_attached_object(node
);
90 return_ACPI_STATUS(AE_NULL_OBJECT
);
93 /* Create a mutex for the method if there is a concurrency limit */
95 if ((obj_desc
->method
.concurrency
!= ACPI_INFINITE_CONCURRENCY
) &&
96 (!obj_desc
->method
.semaphore
)) {
97 status
= acpi_os_create_semaphore(obj_desc
->method
.concurrency
,
98 obj_desc
->method
.concurrency
,
99 &obj_desc
->method
.semaphore
);
100 if (ACPI_FAILURE(status
)) {
101 return_ACPI_STATUS(status
);
106 * Allocate a new parser op to be the root of the parsed
109 op
= acpi_ps_alloc_op(AML_METHOD_OP
);
111 return_ACPI_STATUS(AE_NO_MEMORY
);
114 /* Init new op with the method name and pointer back to the Node */
116 acpi_ps_set_name(op
, node
->name
.integer
);
117 op
->common
.node
= node
;
120 * Get a new owner_id for objects created by this method. Namespace
121 * objects (such as Operation Regions) can be created during the
124 status
= acpi_ut_allocate_owner_id(&obj_desc
->method
.owner_id
);
125 if (ACPI_FAILURE(status
)) {
129 /* Create and initialize a new walk state */
132 acpi_ds_create_walk_state(obj_desc
->method
.owner_id
, NULL
, NULL
,
135 status
= AE_NO_MEMORY
;
139 status
= acpi_ds_init_aml_walk(walk_state
, op
, node
,
140 obj_desc
->method
.aml_start
,
141 obj_desc
->method
.aml_length
, NULL
, 1);
142 if (ACPI_FAILURE(status
)) {
143 acpi_ds_delete_walk_state(walk_state
);
148 * Parse the method, first pass
150 * The first pass load is where newly declared named objects are added into
151 * the namespace. Actual evaluation of the named objects (what would be
152 * called a "second pass") happens during the actual execution of the
153 * method so that operands to the named objects can take on dynamic
156 status
= acpi_ps_parse_aml(walk_state
);
157 if (ACPI_FAILURE(status
)) {
161 ACPI_DEBUG_PRINT((ACPI_DB_PARSE
,
162 "**** [%4.4s] Parsed **** named_obj=%p Op=%p\n",
163 acpi_ut_get_node_name(node
), node
, op
));
166 * Delete the parse tree. We simply re-parse the method for every
167 * execution since there isn't much overhead (compared to keeping lots
168 * of parse trees around)
170 acpi_ns_delete_namespace_subtree(node
);
171 acpi_ns_delete_namespace_by_owner(obj_desc
->method
.owner_id
);
174 acpi_ut_release_owner_id(&obj_desc
->method
.owner_id
);
177 acpi_ps_delete_parse_tree(op
);
178 return_ACPI_STATUS(status
);
181 /*******************************************************************************
183 * FUNCTION: acpi_ds_begin_method_execution
185 * PARAMETERS: method_node - Node of the method
186 * obj_desc - The method object
187 * calling_method_node - Caller of this method (if non-null)
191 * DESCRIPTION: Prepare a method for execution. Parses the method if necessary,
192 * increments the thread count, and waits at the method semaphore
193 * for clearance to execute.
195 ******************************************************************************/
198 acpi_ds_begin_method_execution(struct acpi_namespace_node
*method_node
,
199 union acpi_operand_object
*obj_desc
,
200 struct acpi_namespace_node
*calling_method_node
)
202 acpi_status status
= AE_OK
;
204 ACPI_FUNCTION_TRACE_PTR("ds_begin_method_execution", method_node
);
207 return_ACPI_STATUS(AE_NULL_ENTRY
);
211 * If there is a concurrency limit on this method, we need to
212 * obtain a unit from the method semaphore.
214 if (obj_desc
->method
.semaphore
) {
216 * Allow recursive method calls, up to the reentrancy/concurrency
217 * limit imposed by the SERIALIZED rule and the sync_level method
220 * The point of this code is to avoid permanently blocking a
221 * thread that is making recursive method calls.
223 if (method_node
== calling_method_node
) {
224 if (obj_desc
->method
.thread_count
>=
225 obj_desc
->method
.concurrency
) {
226 return_ACPI_STATUS(AE_AML_METHOD_LIMIT
);
231 * Get a unit from the method semaphore. This releases the
232 * interpreter if we block
235 acpi_ex_system_wait_semaphore(obj_desc
->method
.semaphore
,
239 * allocate owner id for this method
241 if (!obj_desc
->method
.thread_count
) {
242 status
= acpi_ut_allocate_owner_id (&obj_desc
->method
.owner_id
);
243 if (ACPI_FAILURE (status
)) {
244 return_ACPI_STATUS (status
);
250 * Increment the method parse tree thread count since it has been
251 * reentered one more time (even if it is the same thread)
253 obj_desc
->method
.thread_count
++;
254 return_ACPI_STATUS(status
);
257 /*******************************************************************************
259 * FUNCTION: acpi_ds_call_control_method
261 * PARAMETERS: Thread - Info for this thread
262 * this_walk_state - Current walk state
263 * Op - Current Op to be walked
267 * DESCRIPTION: Transfer execution to a called control method
269 ******************************************************************************/
272 acpi_ds_call_control_method(struct acpi_thread_state
*thread
,
273 struct acpi_walk_state
*this_walk_state
,
274 union acpi_parse_object
*op
)
277 struct acpi_namespace_node
*method_node
;
278 struct acpi_walk_state
*next_walk_state
= NULL
;
279 union acpi_operand_object
*obj_desc
;
280 struct acpi_parameter_info info
;
283 ACPI_FUNCTION_TRACE_PTR("ds_call_control_method", this_walk_state
);
285 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH
,
286 "Execute method %p, currentstate=%p\n",
287 this_walk_state
->prev_op
, this_walk_state
));
290 * Get the namespace entry for the control method we are about to call
292 method_node
= this_walk_state
->method_call_node
;
294 return_ACPI_STATUS(AE_NULL_ENTRY
);
297 obj_desc
= acpi_ns_get_attached_object(method_node
);
299 return_ACPI_STATUS(AE_NULL_OBJECT
);
302 /* Init for new method, wait on concurrency semaphore */
304 status
= acpi_ds_begin_method_execution(method_node
, obj_desc
,
305 this_walk_state
->method_node
);
306 if (ACPI_FAILURE(status
)) {
310 if (!(obj_desc
->method
.method_flags
& AML_METHOD_INTERNAL_ONLY
)) {
311 /* 1) Parse: Create a new walk state for the preempting walk */
314 acpi_ds_create_walk_state(obj_desc
->method
.owner_id
, op
,
316 if (!next_walk_state
) {
317 return_ACPI_STATUS(AE_NO_MEMORY
);
320 /* Create and init a Root Node */
322 op
= acpi_ps_create_scope_op();
324 status
= AE_NO_MEMORY
;
328 status
= acpi_ds_init_aml_walk(next_walk_state
, op
, method_node
,
329 obj_desc
->method
.aml_start
,
330 obj_desc
->method
.aml_length
,
332 if (ACPI_FAILURE(status
)) {
333 acpi_ds_delete_walk_state(next_walk_state
);
337 /* Begin AML parse */
339 status
= acpi_ps_parse_aml(next_walk_state
);
340 acpi_ps_delete_parse_tree(op
);
343 /* 2) Execute: Create a new state for the preempting walk */
345 next_walk_state
= acpi_ds_create_walk_state(obj_desc
->method
.owner_id
,
346 NULL
, obj_desc
, thread
);
347 if (!next_walk_state
) {
348 status
= AE_NO_MEMORY
;
352 * The resolved arguments were put on the previous walk state's operand
353 * stack. Operands on the previous walk state stack always
355 * Null terminate the list of arguments
357 this_walk_state
->operands
[this_walk_state
->num_operands
] = NULL
;
359 info
.parameters
= &this_walk_state
->operands
[0];
360 info
.parameter_type
= ACPI_PARAM_ARGS
;
362 status
= acpi_ds_init_aml_walk(next_walk_state
, NULL
, method_node
,
363 obj_desc
->method
.aml_start
,
364 obj_desc
->method
.aml_length
, &info
, 3);
365 if (ACPI_FAILURE(status
)) {
370 * Delete the operands on the previous walkstate operand stack
371 * (they were copied to new objects)
373 for (i
= 0; i
< obj_desc
->method
.param_count
; i
++) {
374 acpi_ut_remove_reference(this_walk_state
->operands
[i
]);
375 this_walk_state
->operands
[i
] = NULL
;
378 /* Clear the operand stack */
380 this_walk_state
->num_operands
= 0;
382 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH
,
383 "Starting nested execution, newstate=%p\n",
386 if (obj_desc
->method
.method_flags
& AML_METHOD_INTERNAL_ONLY
) {
387 status
= obj_desc
->method
.implementation(next_walk_state
);
392 /* Decrement the thread count on the method parse tree */
393 if (next_walk_state
&& (next_walk_state
->method_desc
)) {
394 next_walk_state
->method_desc
->method
.thread_count
--;
396 /* On error, we must delete the new walk state */
397 acpi_ds_terminate_control_method (next_walk_state
);
398 acpi_ds_delete_walk_state (next_walk_state
);
400 return_ACPI_STATUS(status
);
403 /*******************************************************************************
405 * FUNCTION: acpi_ds_restart_control_method
407 * PARAMETERS: walk_state - State for preempted method (caller)
408 * return_desc - Return value from the called method
412 * DESCRIPTION: Restart a method that was preempted by another (nested) method
413 * invocation. Handle the return value (if any) from the callee.
415 ******************************************************************************/
418 acpi_ds_restart_control_method(struct acpi_walk_state
*walk_state
,
419 union acpi_operand_object
*return_desc
)
423 ACPI_FUNCTION_TRACE_PTR("ds_restart_control_method", walk_state
);
425 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH
,
426 "****Restart [%4.4s] Op %p return_value_from_callee %p\n",
427 (char *)&walk_state
->method_node
->name
,
428 walk_state
->method_call_op
, return_desc
));
430 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH
,
431 " return_from_this_method_used?=%X res_stack %p Walk %p\n",
432 walk_state
->return_used
,
433 walk_state
->results
, walk_state
));
435 /* Did the called method return a value? */
438 /* Are we actually going to use the return value? */
440 if (walk_state
->return_used
) {
441 /* Save the return value from the previous method */
443 status
= acpi_ds_result_push(return_desc
, walk_state
);
444 if (ACPI_FAILURE(status
)) {
445 acpi_ut_remove_reference(return_desc
);
446 return_ACPI_STATUS(status
);
450 * Save as THIS method's return value in case it is returned
451 * immediately to yet another method
453 walk_state
->return_desc
= return_desc
;
457 * The following code is the
458 * optional support for a so-called "implicit return". Some AML code
459 * assumes that the last value of the method is "implicitly" returned
460 * to the caller. Just save the last result as the return value.
461 * NOTE: this is optional because the ASL language does not actually
462 * support this behavior.
464 else if (!acpi_ds_do_implicit_return
465 (return_desc
, walk_state
, FALSE
)) {
467 * Delete the return value if it will not be used by the
470 acpi_ut_remove_reference(return_desc
);
474 return_ACPI_STATUS(AE_OK
);
477 /*******************************************************************************
479 * FUNCTION: acpi_ds_terminate_control_method
481 * PARAMETERS: walk_state - State of the method
485 * DESCRIPTION: Terminate a control method. Delete everything that the method
486 * created, delete all locals and arguments, and delete the parse
489 ******************************************************************************/
491 void acpi_ds_terminate_control_method(struct acpi_walk_state
*walk_state
)
493 union acpi_operand_object
*obj_desc
;
494 struct acpi_namespace_node
*method_node
;
497 ACPI_FUNCTION_TRACE_PTR("ds_terminate_control_method", walk_state
);
503 /* The current method object was saved in the walk state */
505 obj_desc
= walk_state
->method_desc
;
510 /* Delete all arguments and locals */
512 acpi_ds_method_data_delete_all(walk_state
);
515 * Lock the parser while we terminate this method.
516 * If this is the last thread executing the method,
517 * we have additional cleanup to perform
519 status
= acpi_ut_acquire_mutex(ACPI_MTX_PARSER
);
520 if (ACPI_FAILURE(status
)) {
524 /* Signal completion of the execution of this method if necessary */
526 if (walk_state
->method_desc
->method
.semaphore
) {
528 acpi_os_signal_semaphore(walk_state
->method_desc
->method
.
530 if (ACPI_FAILURE(status
)) {
531 ACPI_REPORT_ERROR(("Could not signal method semaphore\n"));
534 /* Ignore error and continue cleanup */
538 if (walk_state
->method_desc
->method
.thread_count
) {
539 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH
,
540 "*** Not deleting method namespace, there are still %d threads\n",
541 walk_state
->method_desc
->method
.
545 if (!walk_state
->method_desc
->method
.thread_count
) {
547 * Support to dynamically change a method from not_serialized to
548 * Serialized if it appears that the method is written foolishly and
549 * does not support multiple thread execution. The best example of this
550 * is if such a method creates namespace objects and blocks. A second
551 * thread will fail with an AE_ALREADY_EXISTS exception
553 * This code is here because we must wait until the last thread exits
554 * before creating the synchronization semaphore.
556 if ((walk_state
->method_desc
->method
.concurrency
== 1) &&
557 (!walk_state
->method_desc
->method
.semaphore
)) {
558 status
= acpi_os_create_semaphore(1, 1,
565 * There are no more threads executing this method. Perform
566 * additional cleanup.
568 * The method Node is stored in the walk state
570 method_node
= walk_state
->method_node
;
573 * Delete any namespace entries created immediately underneath
576 status
= acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE
);
577 if (ACPI_FAILURE(status
)) {
581 if (method_node
->child
) {
582 acpi_ns_delete_namespace_subtree(method_node
);
586 * Delete any namespace entries created anywhere else within
589 acpi_ns_delete_namespace_by_owner(walk_state
->method_desc
->
591 status
= acpi_ut_release_mutex(ACPI_MTX_NAMESPACE
);
592 acpi_ut_release_owner_id(&walk_state
->method_desc
->method
.
595 if (ACPI_FAILURE(status
)) {
600 acpi_ut_release_mutex (ACPI_MTX_PARSER
);