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
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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>
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) {
145 "Method reached maximum reentrancy limit (255)"));
146 return_ACPI_STATUS(AE_AML_METHOD_LIMIT);
150 * If there is a concurrency limit on this method, we need to
151 * obtain a unit from the method semaphore.
153 if (obj_desc->method.semaphore) {
155 * Allow recursive method calls, up to the reentrancy/concurrency
156 * limit imposed by the SERIALIZED rule and the sync_level method
159 * The point of this code is to avoid permanently blocking a
160 * thread that is making recursive method calls.
162 if (method_node == calling_method_node) {
163 if (obj_desc->method.thread_count >=
164 obj_desc->method.concurrency) {
165 return_ACPI_STATUS(AE_AML_METHOD_LIMIT);
170 * Get a unit from the method semaphore. This releases the
171 * interpreter if we block
174 acpi_ex_system_wait_semaphore(obj_desc->method.semaphore,
179 * Allocate an Owner ID for this method, only if this is the first thread
180 * to begin concurrent execution. We only need one owner_id, even if the
181 * method is invoked recursively.
183 if (!obj_desc->method.owner_id) {
184 status = acpi_ut_allocate_owner_id(&obj_desc->method.owner_id);
185 if (ACPI_FAILURE(status)) {
186 return_ACPI_STATUS(status);
191 * Increment the method parse tree thread count since it has been
192 * reentered one more time (even if it is the same thread)
194 obj_desc->method.thread_count++;
195 return_ACPI_STATUS(status);
198 /*******************************************************************************
200 * FUNCTION: acpi_ds_call_control_method
202 * PARAMETERS: Thread - Info for this thread
203 * this_walk_state - Current walk state
204 * Op - Current Op to be walked
208 * DESCRIPTION: Transfer execution to a called control method
210 ******************************************************************************/
213 acpi_ds_call_control_method(struct acpi_thread_state *thread,
214 struct acpi_walk_state *this_walk_state,
215 union acpi_parse_object *op)
218 struct acpi_namespace_node *method_node;
219 struct acpi_walk_state *next_walk_state = NULL;
220 union acpi_operand_object *obj_desc;
221 struct acpi_parameter_info info;
224 ACPI_FUNCTION_TRACE_PTR("ds_call_control_method", this_walk_state);
226 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
227 "Execute method %p, currentstate=%p\n",
228 this_walk_state->prev_op, this_walk_state));
231 * Get the namespace entry for the control method we are about to call
233 method_node = this_walk_state->method_call_node;
235 return_ACPI_STATUS(AE_NULL_ENTRY);
238 obj_desc = acpi_ns_get_attached_object(method_node);
240 return_ACPI_STATUS(AE_NULL_OBJECT);
243 /* Init for new method, wait on concurrency semaphore */
245 status = acpi_ds_begin_method_execution(method_node, obj_desc,
246 this_walk_state->method_node);
247 if (ACPI_FAILURE(status)) {
251 if (!(obj_desc->method.method_flags & AML_METHOD_INTERNAL_ONLY)) {
252 /* 1) Parse: Create a new walk state for the preempting walk */
255 acpi_ds_create_walk_state(obj_desc->method.owner_id, op,
257 if (!next_walk_state) {
258 return_ACPI_STATUS(AE_NO_MEMORY);
261 /* Create and init a Root Node */
263 op = acpi_ps_create_scope_op();
265 status = AE_NO_MEMORY;
269 status = acpi_ds_init_aml_walk(next_walk_state, op, method_node,
270 obj_desc->method.aml_start,
271 obj_desc->method.aml_length,
273 if (ACPI_FAILURE(status)) {
274 acpi_ds_delete_walk_state(next_walk_state);
278 /* Begin AML parse */
280 status = acpi_ps_parse_aml(next_walk_state);
281 acpi_ps_delete_parse_tree(op);
284 /* 2) Execute: Create a new state for the preempting walk */
286 next_walk_state = acpi_ds_create_walk_state(obj_desc->method.owner_id,
287 NULL, obj_desc, thread);
288 if (!next_walk_state) {
289 status = AE_NO_MEMORY;
293 * The resolved arguments were put on the previous walk state's operand
294 * stack. Operands on the previous walk state stack always
295 * start at index 0. Also, null terminate the list of arguments
297 this_walk_state->operands[this_walk_state->num_operands] = NULL;
299 info.parameters = &this_walk_state->operands[0];
300 info.parameter_type = ACPI_PARAM_ARGS;
302 status = acpi_ds_init_aml_walk(next_walk_state, NULL, method_node,
303 obj_desc->method.aml_start,
304 obj_desc->method.aml_length, &info, 3);
305 if (ACPI_FAILURE(status)) {
310 * Delete the operands on the previous walkstate operand stack
311 * (they were copied to new objects)
313 for (i = 0; i < obj_desc->method.param_count; i++) {
314 acpi_ut_remove_reference(this_walk_state->operands[i]);
315 this_walk_state->operands[i] = NULL;
318 /* Clear the operand stack */
320 this_walk_state->num_operands = 0;
322 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
323 "Starting nested execution, newstate=%p\n",
326 if (obj_desc->method.method_flags & AML_METHOD_INTERNAL_ONLY) {
327 status = obj_desc->method.implementation(next_walk_state);
330 return_ACPI_STATUS(status);
333 /* Decrement the thread count on the method parse tree */
335 if (next_walk_state && (next_walk_state->method_desc)) {
336 next_walk_state->method_desc->method.thread_count--;
339 /* On error, we must delete the new walk state */
341 acpi_ds_terminate_control_method(next_walk_state);
342 acpi_ds_delete_walk_state(next_walk_state);
343 return_ACPI_STATUS(status);
346 /*******************************************************************************
348 * FUNCTION: acpi_ds_restart_control_method
350 * PARAMETERS: walk_state - State for preempted method (caller)
351 * return_desc - Return value from the called method
355 * DESCRIPTION: Restart a method that was preempted by another (nested) method
356 * invocation. Handle the return value (if any) from the callee.
358 ******************************************************************************/
361 acpi_ds_restart_control_method(struct acpi_walk_state *walk_state,
362 union acpi_operand_object *return_desc)
366 ACPI_FUNCTION_TRACE_PTR("ds_restart_control_method", walk_state);
368 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
369 "****Restart [%4.4s] Op %p return_value_from_callee %p\n",
370 (char *)&walk_state->method_node->name,
371 walk_state->method_call_op, return_desc));
373 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
374 " return_from_this_method_used?=%X res_stack %p Walk %p\n",
375 walk_state->return_used,
376 walk_state->results, walk_state));
378 /* Did the called method return a value? */
381 /* Are we actually going to use the return value? */
383 if (walk_state->return_used) {
384 /* Save the return value from the previous method */
386 status = acpi_ds_result_push(return_desc, walk_state);
387 if (ACPI_FAILURE(status)) {
388 acpi_ut_remove_reference(return_desc);
389 return_ACPI_STATUS(status);
393 * Save as THIS method's return value in case it is returned
394 * immediately to yet another method
396 walk_state->return_desc = return_desc;
400 * The following code is the
401 * optional support for a so-called "implicit return". Some AML code
402 * assumes that the last value of the method is "implicitly" returned
403 * to the caller. Just save the last result as the return value.
404 * NOTE: this is optional because the ASL language does not actually
405 * support this behavior.
407 else if (!acpi_ds_do_implicit_return
408 (return_desc, walk_state, FALSE)) {
410 * Delete the return value if it will not be used by the
413 acpi_ut_remove_reference(return_desc);
417 return_ACPI_STATUS(AE_OK);
420 /*******************************************************************************
422 * FUNCTION: acpi_ds_terminate_control_method
424 * PARAMETERS: walk_state - State of the method
428 * DESCRIPTION: Terminate a control method. Delete everything that the method
429 * created, delete all locals and arguments, and delete the parse
432 ******************************************************************************/
434 void acpi_ds_terminate_control_method(struct acpi_walk_state *walk_state)
436 union acpi_operand_object *obj_desc;
437 struct acpi_namespace_node *method_node;
440 ACPI_FUNCTION_TRACE_PTR("ds_terminate_control_method", walk_state);
446 /* The current method object was saved in the walk state */
448 obj_desc = walk_state->method_desc;
453 /* Delete all arguments and locals */
455 acpi_ds_method_data_delete_all(walk_state);
458 * Lock the parser while we terminate this method.
459 * If this is the last thread executing the method,
460 * we have additional cleanup to perform
462 status = acpi_ut_acquire_mutex(ACPI_MTX_PARSER);
463 if (ACPI_FAILURE(status)) {
467 /* Signal completion of the execution of this method if necessary */
469 if (walk_state->method_desc->method.semaphore) {
471 acpi_os_signal_semaphore(walk_state->method_desc->method.
473 if (ACPI_FAILURE(status)) {
475 "Could not signal method semaphore"));
477 /* Ignore error and continue cleanup */
482 * There are no more threads executing this method. Perform
483 * additional cleanup.
485 * The method Node is stored in the walk state
487 method_node = walk_state->method_node;
489 /* Lock namespace for possible update */
491 status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
492 if (ACPI_FAILURE(status)) {
497 * Delete any namespace entries created immediately underneath
500 if (method_node->child) {
501 acpi_ns_delete_namespace_subtree(method_node);
505 * Delete any namespace entries created anywhere else within
506 * the namespace by the execution of this method
508 acpi_ns_delete_namespace_by_owner(walk_state->method_desc->method.
510 status = acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
512 /* Are there any other threads currently executing this method? */
514 if (walk_state->method_desc->method.thread_count) {
516 * Additional threads. Do not release the owner_id in this case,
517 * we immediately reuse it for the next thread executing this method
519 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
520 "*** Completed execution of one thread, %d threads remaining\n",
521 walk_state->method_desc->method.
524 /* This is the only executing thread for this method */
527 * Support to dynamically change a method from not_serialized to
528 * Serialized if it appears that the method is incorrectly written and
529 * does not support multiple thread execution. The best example of this
530 * is if such a method creates namespace objects and blocks. A second
531 * thread will fail with an AE_ALREADY_EXISTS exception
533 * This code is here because we must wait until the last thread exits
534 * before creating the synchronization semaphore.
536 if ((walk_state->method_desc->method.concurrency == 1) &&
537 (!walk_state->method_desc->method.semaphore)) {
538 status = acpi_os_create_semaphore(1, 1,
544 /* No more threads, we can free the owner_id */
546 acpi_ut_release_owner_id(&walk_state->method_desc->method.
551 (void)acpi_ut_release_mutex(ACPI_MTX_PARSER);
555 #ifdef ACPI_INIT_PARSE_METHODS
557 * Note 11/2005: Removed this code to parse all methods during table
558 * load because it causes problems if there are any errors during the
559 * parse. Also, it seems like overkill and we probably don't want to
560 * abort a table load because of an issue with a single method.
563 /*******************************************************************************
565 * FUNCTION: acpi_ds_parse_method
567 * PARAMETERS: Node - Method node
571 * DESCRIPTION: Parse the AML that is associated with the method.
573 * MUTEX: Assumes parser is locked
575 ******************************************************************************/
577 acpi_status acpi_ds_parse_method(struct acpi_namespace_node *node)
580 union acpi_operand_object *obj_desc;
581 union acpi_parse_object *op;
582 struct acpi_walk_state *walk_state;
584 ACPI_FUNCTION_TRACE_PTR("ds_parse_method", node);
586 /* Parameter Validation */
589 return_ACPI_STATUS(AE_NULL_ENTRY);
592 ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
593 "**** Parsing [%4.4s] **** named_obj=%p\n",
594 acpi_ut_get_node_name(node), node));
596 /* Extract the method object from the method Node */
598 obj_desc = acpi_ns_get_attached_object(node);
600 return_ACPI_STATUS(AE_NULL_OBJECT);
603 /* Create a mutex for the method if there is a concurrency limit */
605 if ((obj_desc->method.concurrency != ACPI_INFINITE_CONCURRENCY) &&
606 (!obj_desc->method.semaphore)) {
607 status = acpi_os_create_semaphore(obj_desc->method.concurrency,
608 obj_desc->method.concurrency,
609 &obj_desc->method.semaphore);
610 if (ACPI_FAILURE(status)) {
611 return_ACPI_STATUS(status);
616 * Allocate a new parser op to be the root of the parsed
619 op = acpi_ps_alloc_op(AML_METHOD_OP);
621 return_ACPI_STATUS(AE_NO_MEMORY);
624 /* Init new op with the method name and pointer back to the Node */
626 acpi_ps_set_name(op, node->name.integer);
627 op->common.node = node;
630 * Get a new owner_id for objects created by this method. Namespace
631 * objects (such as Operation Regions) can be created during the
634 status = acpi_ut_allocate_owner_id(&obj_desc->method.owner_id);
635 if (ACPI_FAILURE(status)) {
639 /* Create and initialize a new walk state */
642 acpi_ds_create_walk_state(obj_desc->method.owner_id, NULL, NULL,
645 status = AE_NO_MEMORY;
649 status = acpi_ds_init_aml_walk(walk_state, op, node,
650 obj_desc->method.aml_start,
651 obj_desc->method.aml_length, NULL, 1);
652 if (ACPI_FAILURE(status)) {
653 acpi_ds_delete_walk_state(walk_state);
658 * Parse the method, first pass
660 * The first pass load is where newly declared named objects are added into
661 * the namespace. Actual evaluation of the named objects (what would be
662 * called a "second pass") happens during the actual execution of the
663 * method so that operands to the named objects can take on dynamic
666 status = acpi_ps_parse_aml(walk_state);
667 if (ACPI_FAILURE(status)) {
671 ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
672 "**** [%4.4s] Parsed **** named_obj=%p Op=%p\n",
673 acpi_ut_get_node_name(node), node, op));
676 * Delete the parse tree. We simply re-parse the method for every
677 * execution since there isn't much overhead (compared to keeping lots
678 * of parse trees around)
680 acpi_ns_delete_namespace_subtree(node);
681 acpi_ns_delete_namespace_by_owner(obj_desc->method.owner_id);
684 acpi_ut_release_owner_id(&obj_desc->method.owner_id);
687 acpi_ps_delete_parse_tree(op);
688 return_ACPI_STATUS(status);