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
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.
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: Node - Method node
65 * DESCRIPTION: Parse the AML that is associated with the method.
67 * MUTEX: Assumes parser is locked
69 ******************************************************************************/
72 acpi_ds_parse_method (
73 struct acpi_namespace_node *node)
76 union acpi_operand_object *obj_desc;
77 union acpi_parse_object *op;
78 struct acpi_walk_state *walk_state;
81 ACPI_FUNCTION_TRACE_PTR ("ds_parse_method", node);
84 /* Parameter Validation */
87 return_ACPI_STATUS (AE_NULL_ENTRY);
90 ACPI_DEBUG_PRINT ((ACPI_DB_PARSE, "**** Parsing [%4.4s] **** named_obj=%p\n",
91 acpi_ut_get_node_name (node), node));
93 /* Extract the method object from the method Node */
95 obj_desc = acpi_ns_get_attached_object (node);
97 return_ACPI_STATUS (AE_NULL_OBJECT);
100 /* Create a mutex for the method if there is a concurrency limit */
102 if ((obj_desc->method.concurrency != ACPI_INFINITE_CONCURRENCY) &&
103 (!obj_desc->method.semaphore)) {
104 status = acpi_os_create_semaphore (obj_desc->method.concurrency,
105 obj_desc->method.concurrency,
106 &obj_desc->method.semaphore);
107 if (ACPI_FAILURE (status)) {
108 return_ACPI_STATUS (status);
113 * Allocate a new parser op to be the root of the parsed
116 op = acpi_ps_alloc_op (AML_METHOD_OP);
118 return_ACPI_STATUS (AE_NO_MEMORY);
121 /* Init new op with the method name and pointer back to the Node */
123 acpi_ps_set_name (op, node->name.integer);
124 op->common.node = node;
127 * Get a new owner_id for objects created by this method. Namespace
128 * objects (such as Operation Regions) can be created during the
131 status = acpi_ut_allocate_owner_id (&obj_desc->method.owner_id);
132 if (ACPI_FAILURE (status)) {
136 /* Create and initialize a new walk state */
138 walk_state = acpi_ds_create_walk_state (
139 obj_desc->method.owner_id, NULL, NULL, NULL);
141 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);
154 * Parse the method, first pass
156 * The first pass load is where newly declared named objects are added into
157 * the namespace. Actual evaluation of the named objects (what would be
158 * called a "second pass") happens during the actual execution of the
159 * method so that operands to the named objects can take on dynamic
162 status = acpi_ps_parse_aml (walk_state);
163 if (ACPI_FAILURE (status)) {
167 ACPI_DEBUG_PRINT ((ACPI_DB_PARSE,
168 "**** [%4.4s] Parsed **** named_obj=%p Op=%p\n",
169 acpi_ut_get_node_name (node), node, op));
172 * Delete the parse tree. We simply re-parse the method for every
173 * execution since there isn't much overhead (compared to keeping lots
174 * of parse trees around)
176 acpi_ns_delete_namespace_subtree (node);
177 acpi_ns_delete_namespace_by_owner (obj_desc->method.owner_id);
180 acpi_ut_release_owner_id (&obj_desc->method.owner_id);
183 acpi_ps_delete_parse_tree (op);
184 return_ACPI_STATUS (status);
188 /*******************************************************************************
190 * FUNCTION: acpi_ds_begin_method_execution
192 * PARAMETERS: method_node - Node of the method
193 * obj_desc - The method object
194 * calling_method_node - Caller of this method (if non-null)
198 * DESCRIPTION: Prepare a method for execution. Parses the method if necessary,
199 * increments the thread count, and waits at the method semaphore
200 * for clearance to execute.
202 ******************************************************************************/
205 acpi_ds_begin_method_execution (
206 struct acpi_namespace_node *method_node,
207 union acpi_operand_object *obj_desc,
208 struct acpi_namespace_node *calling_method_node)
210 acpi_status status = AE_OK;
213 ACPI_FUNCTION_TRACE_PTR ("ds_begin_method_execution", method_node);
217 return_ACPI_STATUS (AE_NULL_ENTRY);
221 * If there is a concurrency limit on this method, we need to
222 * obtain a unit from the method semaphore.
224 if (obj_desc->method.semaphore) {
226 * Allow recursive method calls, up to the reentrancy/concurrency
227 * limit imposed by the SERIALIZED rule and the sync_level method
230 * The point of this code is to avoid permanently blocking a
231 * thread that is making recursive method calls.
233 if (method_node == calling_method_node) {
234 if (obj_desc->method.thread_count >= obj_desc->method.concurrency) {
235 return_ACPI_STATUS (AE_AML_METHOD_LIMIT);
240 * Get a unit from the method semaphore. This releases the
241 * interpreter if we block
243 status = acpi_ex_system_wait_semaphore (obj_desc->method.semaphore,
248 * Increment the method parse tree thread count since it has been
249 * reentered one more time (even if it is the same thread)
251 obj_desc->method.thread_count++;
252 return_ACPI_STATUS (status);
256 /*******************************************************************************
258 * FUNCTION: acpi_ds_call_control_method
260 * PARAMETERS: Thread - Info for this thread
261 * this_walk_state - Current walk state
262 * Op - Current Op to be walked
266 * DESCRIPTION: Transfer execution to a called control method
268 ******************************************************************************/
271 acpi_ds_call_control_method (
272 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;
284 ACPI_FUNCTION_TRACE_PTR ("ds_call_control_method", this_walk_state);
286 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, "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 status = acpi_ut_allocate_owner_id (&obj_desc->method.owner_id);
303 if (ACPI_FAILURE (status)) {
304 return_ACPI_STATUS (status);
307 /* Init for new method, wait on concurrency semaphore */
309 status = acpi_ds_begin_method_execution (method_node, obj_desc,
310 this_walk_state->method_node);
311 if (ACPI_FAILURE (status)) {
315 if (!(obj_desc->method.method_flags & AML_METHOD_INTERNAL_ONLY)) {
316 /* 1) Parse: Create a new walk state for the preempting walk */
318 next_walk_state = acpi_ds_create_walk_state (obj_desc->method.owner_id,
320 if (!next_walk_state) {
321 return_ACPI_STATUS (AE_NO_MEMORY);
324 /* Create and init a Root Node */
326 op = acpi_ps_create_scope_op ();
328 status = AE_NO_MEMORY;
332 status = acpi_ds_init_aml_walk (next_walk_state, op, method_node,
333 obj_desc->method.aml_start, obj_desc->method.aml_length,
335 if (ACPI_FAILURE (status)) {
336 acpi_ds_delete_walk_state (next_walk_state);
340 /* Begin AML parse */
342 status = acpi_ps_parse_aml (next_walk_state);
343 acpi_ps_delete_parse_tree (op);
346 /* 2) Execute: Create a new state for the preempting walk */
348 next_walk_state = acpi_ds_create_walk_state (obj_desc->method.owner_id,
349 NULL, obj_desc, thread);
350 if (!next_walk_state) {
351 status = AE_NO_MEMORY;
355 * The resolved arguments were put on the previous walk state's operand
356 * stack. Operands on the previous walk state stack always
358 * Null terminate the list of arguments
360 this_walk_state->operands [this_walk_state->num_operands] = NULL;
362 info.parameters = &this_walk_state->operands[0];
363 info.parameter_type = ACPI_PARAM_ARGS;
365 status = acpi_ds_init_aml_walk (next_walk_state, NULL, method_node,
366 obj_desc->method.aml_start, obj_desc->method.aml_length,
368 if (ACPI_FAILURE (status)) {
373 * Delete the operands on the previous walkstate operand stack
374 * (they were copied to new objects)
376 for (i = 0; i < obj_desc->method.param_count; i++) {
377 acpi_ut_remove_reference (this_walk_state->operands [i]);
378 this_walk_state->operands [i] = NULL;
381 /* Clear the operand stack */
383 this_walk_state->num_operands = 0;
385 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
386 "Starting nested execution, newstate=%p\n", next_walk_state));
388 if (obj_desc->method.method_flags & AML_METHOD_INTERNAL_ONLY) {
389 status = obj_desc->method.implementation (next_walk_state);
390 return_ACPI_STATUS (status);
393 return_ACPI_STATUS (AE_OK);
396 /* On error, we must delete the new walk state */
399 acpi_ut_release_owner_id (&obj_desc->method.owner_id);
400 if (next_walk_state && (next_walk_state->method_desc)) {
401 /* Decrement the thread count on the method parse tree */
403 next_walk_state->method_desc->method.thread_count--;
405 (void) acpi_ds_terminate_control_method (next_walk_state);
406 acpi_ds_delete_walk_state (next_walk_state);
407 return_ACPI_STATUS (status);
411 /*******************************************************************************
413 * FUNCTION: acpi_ds_restart_control_method
415 * PARAMETERS: walk_state - State for preempted method (caller)
416 * return_desc - Return value from the called method
420 * DESCRIPTION: Restart a method that was preempted by another (nested) method
421 * invocation. Handle the return value (if any) from the callee.
423 ******************************************************************************/
426 acpi_ds_restart_control_method (
427 struct acpi_walk_state *walk_state,
428 union acpi_operand_object *return_desc)
433 ACPI_FUNCTION_TRACE_PTR ("ds_restart_control_method", walk_state);
436 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
437 "****Restart [%4.4s] Op %p return_value_from_callee %p\n",
438 (char *) &walk_state->method_node->name, walk_state->method_call_op,
441 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
442 " return_from_this_method_used?=%X res_stack %p Walk %p\n",
443 walk_state->return_used,
444 walk_state->results, walk_state));
446 /* Did the called method return a value? */
449 /* Are we actually going to use the return value? */
451 if (walk_state->return_used) {
452 /* Save the return value from the previous method */
454 status = acpi_ds_result_push (return_desc, walk_state);
455 if (ACPI_FAILURE (status)) {
456 acpi_ut_remove_reference (return_desc);
457 return_ACPI_STATUS (status);
461 * Save as THIS method's return value in case it is returned
462 * immediately to yet another method
464 walk_state->return_desc = return_desc;
468 * The following code is the
469 * optional support for a so-called "implicit return". Some AML code
470 * assumes that the last value of the method is "implicitly" returned
471 * to the caller. Just save the last result as the return value.
472 * NOTE: this is optional because the ASL language does not actually
473 * support this behavior.
475 else if (!acpi_ds_do_implicit_return (return_desc, walk_state, FALSE)) {
477 * Delete the return value if it will not be used by the
480 acpi_ut_remove_reference (return_desc);
484 return_ACPI_STATUS (AE_OK);
488 /*******************************************************************************
490 * FUNCTION: acpi_ds_terminate_control_method
492 * PARAMETERS: walk_state - State of the method
496 * DESCRIPTION: Terminate a control method. Delete everything that the method
497 * created, delete all locals and arguments, and delete the parse
500 ******************************************************************************/
503 acpi_ds_terminate_control_method (
504 struct acpi_walk_state *walk_state)
506 union acpi_operand_object *obj_desc;
507 struct acpi_namespace_node *method_node;
511 ACPI_FUNCTION_TRACE_PTR ("ds_terminate_control_method", walk_state);
515 return (AE_BAD_PARAMETER);
518 /* The current method object was saved in the walk state */
520 obj_desc = walk_state->method_desc;
522 return_ACPI_STATUS (AE_OK);
525 /* Delete all arguments and locals */
527 acpi_ds_method_data_delete_all (walk_state);
530 * Lock the parser while we terminate this method.
531 * If this is the last thread executing the method,
532 * we have additional cleanup to perform
534 status = acpi_ut_acquire_mutex (ACPI_MTX_PARSER);
535 if (ACPI_FAILURE (status)) {
536 return_ACPI_STATUS (status);
539 /* Signal completion of the execution of this method if necessary */
541 if (walk_state->method_desc->method.semaphore) {
542 status = acpi_os_signal_semaphore (
543 walk_state->method_desc->method.semaphore, 1);
544 if (ACPI_FAILURE (status)) {
545 ACPI_REPORT_ERROR (("Could not signal method semaphore\n"));
548 /* Ignore error and continue cleanup */
552 if (walk_state->method_desc->method.thread_count) {
553 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
554 "*** Not deleting method namespace, there are still %d threads\n",
555 walk_state->method_desc->method.thread_count));
558 if (!walk_state->method_desc->method.thread_count) {
560 * Support to dynamically change a method from not_serialized to
561 * Serialized if it appears that the method is written foolishly and
562 * does not support multiple thread execution. The best example of this
563 * is if such a method creates namespace objects and blocks. A second
564 * thread will fail with an AE_ALREADY_EXISTS exception
566 * This code is here because we must wait until the last thread exits
567 * before creating the synchronization semaphore.
569 if ((walk_state->method_desc->method.concurrency == 1) &&
570 (!walk_state->method_desc->method.semaphore)) {
571 status = acpi_os_create_semaphore (1, 1,
572 &walk_state->method_desc->method.semaphore);
576 * There are no more threads executing this method. Perform
577 * additional cleanup.
579 * The method Node is stored in the walk state
581 method_node = walk_state->method_node;
584 * Delete any namespace entries created immediately underneath
587 status = acpi_ut_acquire_mutex (ACPI_MTX_NAMESPACE);
588 if (ACPI_FAILURE (status)) {
589 return_ACPI_STATUS (status);
592 if (method_node->child) {
593 acpi_ns_delete_namespace_subtree (method_node);
597 * Delete any namespace entries created anywhere else within
600 acpi_ns_delete_namespace_by_owner (walk_state->method_desc->method.owner_id);
601 status = acpi_ut_release_mutex (ACPI_MTX_NAMESPACE);
602 acpi_ut_release_owner_id (&walk_state->method_desc->method.owner_id);
604 if (ACPI_FAILURE (status)) {
605 return_ACPI_STATUS (status);
609 status = acpi_ut_release_mutex (ACPI_MTX_PARSER);
610 return_ACPI_STATUS (status);