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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41 * POSSIBILITY OF SUCH DAMAGES.
45 #include <acpi/acpi.h>
46 #include <acpi/acparser.h>
47 #include <acpi/amlcode.h>
48 #include <acpi/acdispat.h>
49 #include <acpi/acinterp.h>
50 #include <acpi/acnamesp.h>
53 #define _COMPONENT ACPI_DISPATCHER
54 ACPI_MODULE_NAME ("dsmethod")
57 /*******************************************************************************
59 * FUNCTION: acpi_ds_parse_method
61 * PARAMETERS: obj_handle - Method node
65 * DESCRIPTION: Call the parser and parse the AML that is associated with the
68 * MUTEX: Assumes parser is locked
70 ******************************************************************************/
73 acpi_ds_parse_method (
74 acpi_handle obj_handle
)
77 union acpi_operand_object
*obj_desc
;
78 union acpi_parse_object
*op
;
79 struct acpi_namespace_node
*node
;
80 acpi_owner_id owner_id
;
81 struct acpi_walk_state
*walk_state
;
84 ACPI_FUNCTION_TRACE_PTR ("ds_parse_method", obj_handle
);
87 /* Parameter Validation */
90 return_ACPI_STATUS (AE_NULL_ENTRY
);
93 ACPI_DEBUG_PRINT ((ACPI_DB_PARSE
, "**** Parsing [%4.4s] **** named_obj=%p\n",
94 acpi_ut_get_node_name (obj_handle
), obj_handle
));
96 /* Extract the method object from the method Node */
98 node
= (struct acpi_namespace_node
*) obj_handle
;
99 obj_desc
= acpi_ns_get_attached_object (node
);
101 return_ACPI_STATUS (AE_NULL_OBJECT
);
104 /* Create a mutex for the method if there is a concurrency limit */
106 if ((obj_desc
->method
.concurrency
!= ACPI_INFINITE_CONCURRENCY
) &&
107 (!obj_desc
->method
.semaphore
)) {
108 status
= acpi_os_create_semaphore (obj_desc
->method
.concurrency
,
109 obj_desc
->method
.concurrency
,
110 &obj_desc
->method
.semaphore
);
111 if (ACPI_FAILURE (status
)) {
112 return_ACPI_STATUS (status
);
117 * Allocate a new parser op to be the root of the parsed
120 op
= acpi_ps_alloc_op (AML_METHOD_OP
);
122 return_ACPI_STATUS (AE_NO_MEMORY
);
125 /* Init new op with the method name and pointer back to the Node */
127 acpi_ps_set_name (op
, node
->name
.integer
);
128 op
->common
.node
= node
;
131 * Get a new owner_id for objects created by this method. Namespace
132 * objects (such as Operation Regions) can be created during the
135 owner_id
= acpi_ut_allocate_owner_id (ACPI_OWNER_TYPE_METHOD
);
136 obj_desc
->method
.owning_id
= owner_id
;
138 /* Create and initialize a new walk state */
140 walk_state
= acpi_ds_create_walk_state (owner_id
, NULL
, NULL
, NULL
);
142 return_ACPI_STATUS (AE_NO_MEMORY
);
145 status
= acpi_ds_init_aml_walk (walk_state
, op
, node
,
146 obj_desc
->method
.aml_start
,
147 obj_desc
->method
.aml_length
, NULL
, 1);
148 if (ACPI_FAILURE (status
)) {
149 acpi_ds_delete_walk_state (walk_state
);
150 return_ACPI_STATUS (status
);
154 * Parse the method, first pass
156 * The first pass load is where newly declared named objects are
157 * added into the namespace. Actual evaluation of
158 * the named objects (what would be called a "second
159 * pass") happens during the actual execution of the
160 * method so that operands to the named objects can
161 * take on dynamic run-time values.
163 status
= acpi_ps_parse_aml (walk_state
);
164 if (ACPI_FAILURE (status
)) {
165 return_ACPI_STATUS (status
);
168 ACPI_DEBUG_PRINT ((ACPI_DB_PARSE
,
169 "**** [%4.4s] Parsed **** named_obj=%p Op=%p\n",
170 acpi_ut_get_node_name (obj_handle
), obj_handle
, op
));
172 acpi_ps_delete_parse_tree (op
);
173 return_ACPI_STATUS (status
);
177 /*******************************************************************************
179 * FUNCTION: acpi_ds_begin_method_execution
181 * PARAMETERS: method_node - Node of the method
182 * obj_desc - The method object
183 * calling_method_node - Caller of this method (if non-null)
187 * DESCRIPTION: Prepare a method for execution. Parses the method if necessary,
188 * increments the thread count, and waits at the method semaphore
189 * for clearance to execute.
191 ******************************************************************************/
194 acpi_ds_begin_method_execution (
195 struct acpi_namespace_node
*method_node
,
196 union acpi_operand_object
*obj_desc
,
197 struct acpi_namespace_node
*calling_method_node
)
199 acpi_status status
= AE_OK
;
202 ACPI_FUNCTION_TRACE_PTR ("ds_begin_method_execution", method_node
);
206 return_ACPI_STATUS (AE_NULL_ENTRY
);
210 * If there is a concurrency limit on this method, we need to
211 * obtain a unit from the method semaphore.
213 if (obj_desc
->method
.semaphore
) {
215 * Allow recursive method calls, up to the reentrancy/concurrency
216 * limit imposed by the SERIALIZED rule and the sync_level method
219 * The point of this code is to avoid permanently blocking a
220 * thread that is making recursive method calls.
222 if (method_node
== calling_method_node
) {
223 if (obj_desc
->method
.thread_count
>= obj_desc
->method
.concurrency
) {
224 return_ACPI_STATUS (AE_AML_METHOD_LIMIT
);
229 * Get a unit from the method semaphore. This releases the
230 * interpreter if we block
232 status
= acpi_ex_system_wait_semaphore (obj_desc
->method
.semaphore
,
237 * Increment the method parse tree thread count since it has been
238 * reentered one more time (even if it is the same thread)
240 obj_desc
->method
.thread_count
++;
241 return_ACPI_STATUS (status
);
245 /*******************************************************************************
247 * FUNCTION: acpi_ds_call_control_method
249 * PARAMETERS: Thread - Info for this thread
250 * this_walk_state - Current walk state
251 * Op - Current Op to be walked
255 * DESCRIPTION: Transfer execution to a called control method
257 ******************************************************************************/
260 acpi_ds_call_control_method (
261 struct acpi_thread_state
*thread
,
262 struct acpi_walk_state
*this_walk_state
,
263 union acpi_parse_object
*op
)
266 struct acpi_namespace_node
*method_node
;
267 struct acpi_walk_state
*next_walk_state
;
268 union acpi_operand_object
*obj_desc
;
269 struct acpi_parameter_info info
;
273 ACPI_FUNCTION_TRACE_PTR ("ds_call_control_method", this_walk_state
);
275 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH
, "Execute method %p, currentstate=%p\n",
276 this_walk_state
->prev_op
, this_walk_state
));
279 * Get the namespace entry for the control method we are about to call
281 method_node
= this_walk_state
->method_call_node
;
283 return_ACPI_STATUS (AE_NULL_ENTRY
);
286 obj_desc
= acpi_ns_get_attached_object (method_node
);
288 return_ACPI_STATUS (AE_NULL_OBJECT
);
291 obj_desc
->method
.owning_id
= acpi_ut_allocate_owner_id (ACPI_OWNER_TYPE_METHOD
);
293 /* Init for new method, wait on concurrency semaphore */
295 status
= acpi_ds_begin_method_execution (method_node
, obj_desc
,
296 this_walk_state
->method_node
);
297 if (ACPI_FAILURE (status
)) {
298 return_ACPI_STATUS (status
);
301 if (!(obj_desc
->method
.method_flags
& AML_METHOD_INTERNAL_ONLY
)) {
302 /* 1) Parse: Create a new walk state for the preempting walk */
304 next_walk_state
= acpi_ds_create_walk_state (obj_desc
->method
.owning_id
,
306 if (!next_walk_state
) {
307 return_ACPI_STATUS (AE_NO_MEMORY
);
310 /* Create and init a Root Node */
312 op
= acpi_ps_create_scope_op ();
314 status
= AE_NO_MEMORY
;
318 status
= acpi_ds_init_aml_walk (next_walk_state
, op
, method_node
,
319 obj_desc
->method
.aml_start
, obj_desc
->method
.aml_length
,
321 if (ACPI_FAILURE (status
)) {
322 acpi_ds_delete_walk_state (next_walk_state
);
326 /* Begin AML parse */
328 status
= acpi_ps_parse_aml (next_walk_state
);
329 acpi_ps_delete_parse_tree (op
);
332 /* 2) Execute: Create a new state for the preempting walk */
334 next_walk_state
= acpi_ds_create_walk_state (obj_desc
->method
.owning_id
,
335 NULL
, obj_desc
, thread
);
336 if (!next_walk_state
) {
337 status
= AE_NO_MEMORY
;
341 * The resolved arguments were put on the previous walk state's operand
342 * stack. Operands on the previous walk state stack always
344 * Null terminate the list of arguments
346 this_walk_state
->operands
[this_walk_state
->num_operands
] = NULL
;
348 info
.parameters
= &this_walk_state
->operands
[0];
349 info
.parameter_type
= ACPI_PARAM_ARGS
;
351 status
= acpi_ds_init_aml_walk (next_walk_state
, NULL
, method_node
,
352 obj_desc
->method
.aml_start
, obj_desc
->method
.aml_length
,
354 if (ACPI_FAILURE (status
)) {
359 * Delete the operands on the previous walkstate operand stack
360 * (they were copied to new objects)
362 for (i
= 0; i
< obj_desc
->method
.param_count
; i
++) {
363 acpi_ut_remove_reference (this_walk_state
->operands
[i
]);
364 this_walk_state
->operands
[i
] = NULL
;
367 /* Clear the operand stack */
369 this_walk_state
->num_operands
= 0;
371 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH
,
372 "Starting nested execution, newstate=%p\n", next_walk_state
));
374 if (obj_desc
->method
.method_flags
& AML_METHOD_INTERNAL_ONLY
) {
375 status
= obj_desc
->method
.implementation (next_walk_state
);
376 return_ACPI_STATUS (status
);
379 return_ACPI_STATUS (AE_OK
);
382 /* On error, we must delete the new walk state */
385 if (next_walk_state
&& (next_walk_state
->method_desc
)) {
386 /* Decrement the thread count on the method parse tree */
388 next_walk_state
->method_desc
->method
.thread_count
--;
390 (void) acpi_ds_terminate_control_method (next_walk_state
);
391 acpi_ds_delete_walk_state (next_walk_state
);
392 return_ACPI_STATUS (status
);
396 /*******************************************************************************
398 * FUNCTION: acpi_ds_restart_control_method
400 * PARAMETERS: walk_state - State for preempted method (caller)
401 * return_desc - Return value from the called method
405 * DESCRIPTION: Restart a method that was preempted by another (nested) method
406 * invocation. Handle the return value (if any) from the callee.
408 ******************************************************************************/
411 acpi_ds_restart_control_method (
412 struct acpi_walk_state
*walk_state
,
413 union acpi_operand_object
*return_desc
)
418 ACPI_FUNCTION_TRACE_PTR ("ds_restart_control_method", walk_state
);
421 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH
,
422 "****Restart [%4.4s] Op %p return_value_from_callee %p\n",
423 (char *) &walk_state
->method_node
->name
, walk_state
->method_call_op
,
426 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH
,
427 " return_from_this_method_used?=%X res_stack %p Walk %p\n",
428 walk_state
->return_used
,
429 walk_state
->results
, walk_state
));
431 /* Did the called method return a value? */
434 /* Are we actually going to use the return value? */
436 if (walk_state
->return_used
) {
437 /* Save the return value from the previous method */
439 status
= acpi_ds_result_push (return_desc
, walk_state
);
440 if (ACPI_FAILURE (status
)) {
441 acpi_ut_remove_reference (return_desc
);
442 return_ACPI_STATUS (status
);
446 * Save as THIS method's return value in case it is returned
447 * immediately to yet another method
449 walk_state
->return_desc
= return_desc
;
453 * The following code is the
454 * optional support for a so-called "implicit return". Some AML code
455 * assumes that the last value of the method is "implicitly" returned
456 * to the caller. Just save the last result as the return value.
457 * NOTE: this is optional because the ASL language does not actually
458 * support this behavior.
460 else if (!acpi_ds_do_implicit_return (return_desc
, walk_state
, FALSE
)) {
462 * Delete the return value if it will not be used by the
465 acpi_ut_remove_reference (return_desc
);
469 return_ACPI_STATUS (AE_OK
);
473 /*******************************************************************************
475 * FUNCTION: acpi_ds_terminate_control_method
477 * PARAMETERS: walk_state - State of the method
481 * DESCRIPTION: Terminate a control method. Delete everything that the method
482 * created, delete all locals and arguments, and delete the parse
485 ******************************************************************************/
488 acpi_ds_terminate_control_method (
489 struct acpi_walk_state
*walk_state
)
491 union acpi_operand_object
*obj_desc
;
492 struct acpi_namespace_node
*method_node
;
496 ACPI_FUNCTION_TRACE_PTR ("ds_terminate_control_method", walk_state
);
500 return (AE_BAD_PARAMETER
);
503 /* The current method object was saved in the walk state */
505 obj_desc
= walk_state
->method_desc
;
507 return_ACPI_STATUS (AE_OK
);
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
)) {
521 return_ACPI_STATUS (status
);
524 /* Signal completion of the execution of this method if necessary */
526 if (walk_state
->method_desc
->method
.semaphore
) {
527 status
= acpi_os_signal_semaphore (
528 walk_state
->method_desc
->method
.semaphore
, 1);
529 if (ACPI_FAILURE (status
)) {
530 ACPI_REPORT_ERROR (("Could not signal method semaphore\n"));
533 /* Ignore error and continue cleanup */
537 if (walk_state
->method_desc
->method
.thread_count
) {
538 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH
,
539 "*** Not deleting method namespace, there are still %d threads\n",
540 walk_state
->method_desc
->method
.thread_count
));
543 if (!walk_state
->method_desc
->method
.thread_count
) {
545 * Support to dynamically change a method from not_serialized to
546 * Serialized if it appears that the method is written foolishly and
547 * does not support multiple thread execution. The best example of this
548 * is if such a method creates namespace objects and blocks. A second
549 * thread will fail with an AE_ALREADY_EXISTS exception
551 * This code is here because we must wait until the last thread exits
552 * before creating the synchronization semaphore.
554 if ((walk_state
->method_desc
->method
.concurrency
== 1) &&
555 (!walk_state
->method_desc
->method
.semaphore
)) {
556 status
= acpi_os_create_semaphore (1,
558 &walk_state
->method_desc
->method
.semaphore
);
562 * There are no more threads executing this method. Perform
563 * additional cleanup.
565 * The method Node is stored in the walk state
567 method_node
= walk_state
->method_node
;
570 * Delete any namespace entries created immediately underneath
573 status
= acpi_ut_acquire_mutex (ACPI_MTX_NAMESPACE
);
574 if (ACPI_FAILURE (status
)) {
575 return_ACPI_STATUS (status
);
578 if (method_node
->child
) {
579 acpi_ns_delete_namespace_subtree (method_node
);
583 * Delete any namespace entries created anywhere else within
586 acpi_ns_delete_namespace_by_owner (walk_state
->method_desc
->method
.owning_id
);
587 status
= acpi_ut_release_mutex (ACPI_MTX_NAMESPACE
);
588 if (ACPI_FAILURE (status
)) {
589 return_ACPI_STATUS (status
);
593 status
= acpi_ut_release_mutex (ACPI_MTX_PARSER
);
594 return_ACPI_STATUS (status
);