/******************************************************************************
*
* Module Name: dsmethod - Parser/Interpreter interface - control method parsing
*
*****************************************************************************/
/*
* Copyright (C) 2000 - 2005, R. Byron Moore
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions, and the following disclaimer,
* without modification.
* 2. Redistributions in binary form must reproduce at minimum a disclaimer
* substantially similar to the "NO WARRANTY" disclaimer below
* ("Disclaimer") and any redistribution must be conditioned upon
* including a substantially similar Disclaimer requirement for further
* binary redistribution.
* 3. Neither the names of the above-listed copyright holders nor the names
* of any contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL") version 2 as published by the Free
* Software Foundation.
*
* NO WARRANTY
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGES.
*/
#include <acpi/acpi.h>
#include <acpi/acparser.h>
#include <acpi/amlcode.h>
#include <acpi/acdispat.h>
#include <acpi/acinterp.h>
#include <acpi/acnamesp.h>
#define _COMPONENT ACPI_DISPATCHER
ACPI_MODULE_NAME("dsmethod")
/*******************************************************************************
*
* FUNCTION: acpi_ds_parse_method
*
* PARAMETERS: Node - Method node
*
* RETURN: Status
*
* DESCRIPTION: Parse the AML that is associated with the method.
*
* MUTEX: Assumes parser is locked
*
******************************************************************************/
acpi_status acpi_ds_parse_method(struct acpi_namespace_node *node)
{
acpi_status status;
union acpi_operand_object *obj_desc;
union acpi_parse_object *op;
struct acpi_walk_state *walk_state;
ACPI_FUNCTION_TRACE_PTR("ds_parse_method", node);
/* Parameter Validation */
if (!node) {
return_ACPI_STATUS(AE_NULL_ENTRY);
}
ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
"**** Parsing [%4.4s] **** named_obj=%p\n",
acpi_ut_get_node_name(node), node));
/* Extract the method object from the method Node */
obj_desc = acpi_ns_get_attached_object(node);
if (!obj_desc) {
return_ACPI_STATUS(AE_NULL_OBJECT);
}
/* Create a mutex for the method if there is a concurrency limit */
if ((obj_desc->method.concurrency != ACPI_INFINITE_CONCURRENCY) &&
(!obj_desc->method.semaphore)) {
status = acpi_os_create_semaphore(obj_desc->method.concurrency,
obj_desc->method.concurrency,
&obj_desc->method.semaphore);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
}
/*
* Allocate a new parser op to be the root of the parsed
* method tree
*/
op = acpi_ps_alloc_op(AML_METHOD_OP);
if (!op) {
return_ACPI_STATUS(AE_NO_MEMORY);
}
/* Init new op with the method name and pointer back to the Node */
acpi_ps_set_name(op, node->name.integer);
op->common.node = node;
/*
* Get a new owner_id for objects created by this method. Namespace
* objects (such as Operation Regions) can be created during the
* first pass parse.
*/
status = acpi_ut_allocate_owner_id(&obj_desc->method.owner_id);
if (ACPI_FAILURE(status)) {
goto cleanup;
}
/* Create and initialize a new walk state */
walk_state =
acpi_ds_create_walk_state(obj_desc->method.owner_id, NULL, NULL,
NULL);
if (!walk_state) {
status = AE_NO_MEMORY;
goto cleanup2;
}
status = acpi_ds_init_aml_walk(walk_state, op, node,
obj_desc->method.aml_start,
obj_desc->method.aml_length, NULL, 1);
if (ACPI_FAILURE(status)) {
acpi_ds_delete_walk_state(walk_state);
goto cleanup2;
}
/*
* Parse the method, first pass
*
* The first pass load is where newly declared named objects are added into
* the namespace. Actual evaluation of the named objects (what would be
* called a "second pass") happens during the actual execution of the
* method so that operands to the named objects can take on dynamic
* run-time values.
*/
status = acpi_ps_parse_aml(walk_state);
if (ACPI_FAILURE(status)) {
goto cleanup2;
}
ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
"**** [%4.4s] Parsed **** named_obj=%p Op=%p\n",
acpi_ut_get_node_name(node), node, op));
/*
* Delete the parse tree. We simply re-parse the method for every
* execution since there isn't much overhead (compared to keeping lots
* of parse trees around)
*/
acpi_ns_delete_namespace_subtree(node);
acpi_ns_delete_namespace_by_owner(obj_desc->method.owner_id);
cleanup2:
acpi_ut_release_owner_id(&obj_desc->method.owner_id);
cleanup:
acpi_ps_delete_parse_tree(op);
return_ACPI_STATUS(status);
}
/*******************************************************************************
*
* FUNCTION: acpi_ds_begin_method_execution
*
* PARAMETERS: method_node - Node of the method
* obj_desc - The method object
* calling_method_node - Caller of this method (if non-null)
*
* RETURN: Status
*
* DESCRIPTION: Prepare a method for execution. Parses the method if necessary,
* increments the thread count, and waits at the method semaphore
* for clearance to execute.
*
******************************************************************************/
acpi_status
acpi_ds_begin_method_execution(struct acpi_namespace_node *method_node,
union acpi_operand_object *obj_desc,
struct acpi_namespace_node *calling_method_node)
{
acpi_status status = AE_OK;
ACPI_FUNCTION_TRACE_PTR("ds_begin_method_execution", method_node);
if (!method_node) {
return_ACPI_STATUS(AE_NULL_ENTRY);
}
/* Prevent wraparound of thread count */
if (obj_desc->method.thread_count == ACPI_UINT8_MAX) {
ACPI_REPORT_ERROR(("Method reached maximum reentrancy limit (255)\n"));
return_ACPI_STATUS(AE_AML_METHOD_LIMIT);
}
/*
* If there is a concurrency limit on this method, we need to
* obtain a unit from the method semaphore.
*/
if (obj_desc->method.semaphore) {
/*
* Allow recursive method calls, up to the reentrancy/concurrency
* limit imposed by the SERIALIZED rule and the sync_level method
* parameter.
*
* The point of this code is to avoid permanently blocking a
* thread that is making recursive method calls.
*/
if (method_node == calling_method_node) {
if (obj_desc->method.thread_count >=
obj_desc->method.concurrency) {
return_ACPI_STATUS(AE_AML_METHOD_LIMIT);
}
}
/*
* Get a unit from the method semaphore. This releases the
* interpreter if we block
*/
status =
acpi_ex_system_wait_semaphore(obj_desc->method.semaphore,
ACPI_WAIT_FOREVER);
}
/*
* Allocate an Owner ID for this method, only if this is the first thread
* to begin concurrent execution. We only need one owner_id, even if the
* method is invoked recursively.
*/
if (!obj_desc->method.owner_id) {
status = acpi_ut_allocate_owner_id(&obj_desc->method.owner_id);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
}
/*
* Increment the method parse tree thread count since it has been
* reentered one more time (even if it is the same thread)
*/
obj_desc->method.thread_count++;
return_ACPI_STATUS(status);
}
/*******************************************************************************
*
* FUNCTION: acpi_ds_call_control_method
*
* PARAMETERS: Thread - Info for this thread
* this_walk_state - Current walk state
* Op - Current Op to be walked
*
* RETURN: Status
*
* DESCRIPTION: Transfer execution to a called control method
*
******************************************************************************/
acpi_status
acpi_ds_call_control_method(struct acpi_thread_state *thread,
struct acpi_walk_state *this_walk_state,
union acpi_parse_object *op)
{
acpi_status status;
struct acpi_namespace_node *method_node;
struct acpi_walk_state *next_walk_state = NULL;
union acpi_operand_object *obj_desc;
struct acpi_parameter_info info;
u32 i;
ACPI_FUNCTION_TRACE_PTR("ds_call_control_method", this_walk_state);
ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
"Execute method %p, currentstate=%p\n",
this_walk_state->prev_op, this_walk_state));
/*
* Get the namespace entry for the control method we are about to call
*/
method_node = this_walk_state->method_call_node;
if (!method_node) {
return_ACPI_STATUS(AE_NULL_ENTRY);
}
obj_desc = acpi_ns_get_attached_object(method_node);
if (!obj_desc) {
return_ACPI_STATUS(AE_NULL_OBJECT);
}
/* Init for new method, wait on concurrency semaphore */
status = acpi_ds_begin_method_execution(method_node, obj_desc,
this_walk_state->method_node);
if (ACPI_FAILURE(status)) {
goto cleanup;
}
if (!(obj_desc->method.method_flags & AML_METHOD_INTERNAL_ONLY)) {
/* 1) Parse: Create a new walk state for the preempting walk */
next_walk_state =
acpi_ds_create_walk_state(obj_desc->method.owner_id, op,
obj_desc, NULL);
if (!next_walk_state) {
return_ACPI_STATUS(AE_NO_MEMORY);
}
/* Create and init a Root Node */
op = acpi_ps_create_scope_op();
if (!op) {
status = AE_NO_MEMORY;
goto cleanup;
}
status = acpi_ds_init_aml_walk(next_walk_state, op, method_node,
obj_desc->method.aml_start,
obj_desc->method.aml_length,
NULL, 1);
if (ACPI_FAILURE(status)) {
acpi_ds_delete_walk_state(next_walk_state);
goto cleanup;
}
/* Begin AML parse */
status = acpi_ps_parse_aml(next_walk_state);
acpi_ps_delete_parse_tree(op);
}
/* 2) Execute: Create a new state for the preempting walk */
next_walk_state = acpi_ds_create_walk_state(obj_desc->method.owner_id,
NULL, obj_desc, thread);
if (!next_walk_state) {
status = AE_NO_MEMORY;
goto cleanup;
}
/*
* The resolved arguments were put on the previous walk state's operand
* stack. Operands on the previous walk state stack always
* start at index 0. Also, null terminate the list of arguments
*/
this_walk_state->operands[this_walk_state->num_operands] = NULL;
info.parameters = &this_walk_state->operands[0];
info.parameter_type = ACPI_PARAM_ARGS;
status = acpi_ds_init_aml_walk(next_walk_state, NULL, method_node,
obj_desc->method.aml_start,
obj_desc->method.aml_length, &info, 3);
if (ACPI_FAILURE(status)) {
goto cleanup;
}
/*
* Delete the operands on the previous walkstate operand stack
* (they were copied to new objects)
*/
for (i = 0; i < obj_desc->method.param_count; i++) {
acpi_ut_remove_reference(this_walk_state->operands[i]);
this_walk_state->operands[i] = NULL;
}
/* Clear the operand stack */
this_walk_state->num_operands = 0;
ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
"Starting nested execution, newstate=%p\n",
next_walk_state));
if (obj_desc->method.method_flags & AML_METHOD_INTERNAL_ONLY) {
status = obj_desc->method.implementation(next_walk_state);
}
return_ACPI_STATUS(status);
cleanup:
/* Decrement the thread count on the method parse tree */
if (next_walk_state && (next_walk_state->method_desc)) {
next_walk_state->method_desc->method.thread_count--;
}
/* On error, we must delete the new walk state */
acpi_ds_terminate_control_method(next_walk_state);
acpi_ds_delete_walk_state(next_walk_state);
return_ACPI_STATUS(status);
}
/*******************************************************************************
*
* FUNCTION: acpi_ds_restart_control_method
*
* PARAMETERS: walk_state - State for preempted method (caller)
* return_desc - Return value from the called method
*
* RETURN: Status
*
* DESCRIPTION: Restart a method that was preempted by another (nested) method
* invocation. Handle the return value (if any) from the callee.
*
******************************************************************************/
acpi_status
acpi_ds_restart_control_method(struct acpi_walk_state *walk_state,
union acpi_operand_object *return_desc)
{
acpi_status status;
ACPI_FUNCTION_TRACE_PTR("ds_restart_control_method", walk_state);
ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
"****Restart [%4.4s] Op %p return_value_from_callee %p\n",
(char *)&walk_state->method_node->name,
walk_state->method_call_op, return_desc));
ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
" return_from_this_method_used?=%X res_stack %p Walk %p\n",
walk_state->return_used,
walk_state->results, walk_state));
/* Did the called method return a value? */
if (return_desc) {
/* Are we actually going to use the return value? */
if (walk_state->return_used) {
/* Save the return value from the previous method */
status = acpi_ds_result_push(return_desc, walk_state);
if (ACPI_FAILURE(status)) {
acpi_ut_remove_reference(return_desc);
return_ACPI_STATUS(status);
}
/*
* Save as THIS method's return value in case it is returned
* immediately to yet another method
*/
walk_state->return_desc = return_desc;
}
/*
* The following code is the
* optional support for a so-called "implicit return". Some AML code
* assumes that the last value of the method is "implicitly" returned
* to the caller. Just save the last result as the return value.
* NOTE: this is optional because the ASL language does not actually
* support this behavior.
*/
else if (!acpi_ds_do_implicit_return
(return_desc, walk_state, FALSE)) {
/*
* Delete the return value if it will not be used by the
* calling method
*/
acpi_ut_remove_reference(return_desc);
}
}
return_ACPI_STATUS(AE_OK);
}
/*******************************************************************************
*
* FUNCTION: acpi_ds_terminate_control_method
*
* PARAMETERS: walk_state - State of the method
*
* RETURN: None
*
* DESCRIPTION: Terminate a control method. Delete everything that the method
* created, delete all locals and arguments, and delete the parse
* tree if requested.
*
******************************************************************************/
void acpi_ds_terminate_control_method(struct acpi_walk_state *walk_state)
{
union acpi_operand_object *obj_desc;
struct acpi_namespace_node *method_node;
acpi_status status;
ACPI_FUNCTION_TRACE_PTR("ds_terminate_control_method", walk_state);
if (!walk_state) {
return_VOID;
}
/* The current method object was saved in the walk state */
obj_desc = walk_state->method_desc;
if (!obj_desc) {
return_VOID;
}
/* Delete all arguments and locals */
acpi_ds_method_data_delete_all(walk_state);
/*
* Lock the parser while we terminate this method.
* If this is the last thread executing the method,
* we have additional cleanup to perform
*/
status = acpi_ut_acquire_mutex(ACPI_MTX_PARSER);
if (ACPI_FAILURE(status)) {
return_VOID;
}
/* Signal completion of the execution of this method if necessary */
if (walk_state->method_desc->method.semaphore) {
status =
acpi_os_signal_semaphore(walk_state->method_desc->method.
semaphore, 1);
if (ACPI_FAILURE(status)) {
ACPI_REPORT_ERROR(("Could not signal method semaphore\n"));
/* Ignore error and continue cleanup */
}
}
if (walk_state->method_desc->method.thread_count) {
ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
"*** Not deleting method namespace, there are still %d threads\n",
walk_state->method_desc->method.
thread_count));
} else { /* This is the last executing thread */
/*
* Support to dynamically change a method from not_serialized to
* Serialized if it appears that the method is written foolishly and
* does not support multiple thread execution. The best example of this
* is if such a method creates namespace objects and blocks. A second
* thread will fail with an AE_ALREADY_EXISTS exception
*
* This code is here because we must wait until the last thread exits
* before creating the synchronization semaphore.
*/
if ((walk_state->method_desc->method.concurrency == 1) &&
(!walk_state->method_desc->method.semaphore)) {
status = acpi_os_create_semaphore(1, 1,
&walk_state->
method_desc->method.
semaphore);
}
/*
* There are no more threads executing this method. Perform
* additional cleanup.
*
* The method Node is stored in the walk state
*/
method_node = walk_state->method_node;
/*
* Delete any namespace entries created immediately underneath
* the method
*/
status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
if (ACPI_FAILURE(status)) {
goto exit;
}
if (method_node->child) {
acpi_ns_delete_namespace_subtree(method_node);
}
/*
* Delete any namespace entries created anywhere else within
* the namespace
*/
acpi_ns_delete_namespace_by_owner(walk_state->method_desc->
method.owner_id);
status = acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
acpi_ut_release_owner_id(&walk_state->method_desc->method.
owner_id);
}
exit:
(void)acpi_ut_release_mutex(ACPI_MTX_PARSER);
return_VOID;
}
