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>
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);