/******************************************************************************
*
* Module Name: dsmethod - Parser/Interpreter interface - control method parsing
*
*****************************************************************************/
/*
* Copyright (C) 2000 - 2013, Intel Corp.
* 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 "accommon.h"
#include "acdispat.h"
#include "acinterp.h"
#include "acnamesp.h"
#ifdef ACPI_DISASSEMBLER
#include "acdisasm.h"
#endif
#define _COMPONENT ACPI_DISPATCHER
ACPI_MODULE_NAME("dsmethod")
/* Local prototypes */
static acpi_status
acpi_ds_create_method_mutex(union acpi_operand_object *method_desc);
/*******************************************************************************
*
* FUNCTION: acpi_ds_method_error
*
* PARAMETERS: status - Execution status
* walk_state - Current state
*
* RETURN: Status
*
* DESCRIPTION: Called on method error. Invoke the global exception handler if
* present, dump the method data if the disassembler is configured
*
* Note: Allows the exception handler to change the status code
*
******************************************************************************/
acpi_status
acpi_ds_method_error(acpi_status status, struct acpi_walk_state *walk_state)
{
ACPI_FUNCTION_ENTRY();
/* Ignore AE_OK and control exception codes */
if (ACPI_SUCCESS(status) || (status & AE_CODE_CONTROL)) {
return (status);
}
/* Invoke the global exception handler */
if (acpi_gbl_exception_handler) {
/* Exit the interpreter, allow handler to execute methods */
acpi_ex_exit_interpreter();
/*
* Handler can map the exception code to anything it wants, including
* AE_OK, in which case the executing method will not be aborted.
*/
status = acpi_gbl_exception_handler(status,
walk_state->method_node ?
walk_state->method_node->
name.integer : 0,
walk_state->opcode,
walk_state->aml_offset,
NULL);
acpi_ex_enter_interpreter();
}
acpi_ds_clear_implicit_return(walk_state);
#ifdef ACPI_DISASSEMBLER
if (ACPI_FAILURE(status)) {
/* Display method locals/args if disassembler is present */
acpi_dm_dump_method_info(status, walk_state, walk_state->op);
}
#endif
return (status);
}
/*******************************************************************************
*
* FUNCTION: acpi_ds_create_method_mutex
*
* PARAMETERS: obj_desc - The method object
*
* RETURN: Status
*
* DESCRIPTION: Create a mutex object for a serialized control method
*
******************************************************************************/
static acpi_status
acpi_ds_create_method_mutex(union acpi_operand_object *method_desc)
{
union acpi_operand_object *mutex_desc;
acpi_status status;
ACPI_FUNCTION_TRACE(ds_create_method_mutex);
/* Create the new mutex object */
mutex_desc = acpi_ut_create_internal_object(ACPI_TYPE_MUTEX);
if (!mutex_desc) {
return_ACPI_STATUS(AE_NO_MEMORY);
}
/* Create the actual OS Mutex */
status = acpi_os_create_mutex(&mutex_desc->mutex.os_mutex);
if (ACPI_FAILURE(status)) {
acpi_ut_delete_object_desc(mutex_desc);
return_ACPI_STATUS(status);
}
mutex_desc->mutex.sync_level = method_desc->method.sync_level;
method_desc->method.mutex = mutex_desc;
return_ACPI_STATUS(AE_OK);
}
/*******************************************************************************
*
* FUNCTION: acpi_ds_begin_method_execution
*
* PARAMETERS: method_node - Node of the method
* obj_desc - The method object
* walk_state - current state, NULL if not yet executing
* a method.
*
* 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_walk_state *walk_state)
{
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_ERROR((AE_INFO,
"Method reached maximum reentrancy limit (255)"));
return_ACPI_STATUS(AE_AML_METHOD_LIMIT);
}
/*
* If this method is serialized, we need to acquire the method mutex.
*/
if (obj_desc->method.info_flags & ACPI_METHOD_SERIALIZED) {
/*
* Create a mutex for the method if it is defined to be Serialized
* and a mutex has not already been created. We defer the mutex creation
* until a method is actually executed, to minimize the object count
*/
if (!obj_desc->method.mutex) {
status = acpi_ds_create_method_mutex(obj_desc);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
}
/*
* The current_sync_level (per-thread) must be less than or equal to
* the sync level of the method. This mechanism provides some
* deadlock prevention
*
* Top-level method invocation has no walk state at this point
*/
if (walk_state &&
(walk_state->thread->current_sync_level >
obj_desc->method.mutex->mutex.sync_level)) {
ACPI_ERROR((AE_INFO,
"Cannot acquire Mutex for method [%4.4s], current SyncLevel is too large (%u)",
acpi_ut_get_node_name(method_node),
walk_state->thread->current_sync_level));
return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
}
/*
* Obtain the method mutex if necessary. Do not acquire mutex for a
* recursive call.
*/
if (!walk_state ||
!obj_desc->method.mutex->mutex.thread_id ||
(walk_state->thread->thread_id !=
obj_desc->method.mutex->mutex.thread_id)) {
/*
* Acquire the method mutex. This releases the interpreter if we
* block (and reacquires it before it returns)
*/
status =
acpi_ex_system_wait_mutex(obj_desc->method.mutex->
mutex.os_mutex,
ACPI_WAIT_FOREVER);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
/* Update the mutex and walk info and save the original sync_level */
if (walk_state) {
obj_desc->method.mutex->mutex.
original_sync_level =
walk_state->thread->current_sync_level;
obj_desc->method.mutex->mutex.thread_id =
walk_state->thread->thread_id;
walk_state->thread->current_sync_level =
obj_desc->method.sync_level;
} else {
obj_desc->method.mutex->mutex.
original_sync_level =
obj_desc->method.mutex->mutex.sync_level;
}
}
/* Always increase acquisition depth */
obj_desc->method.mutex->mutex.acquisition_depth++;
}
/*
* 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)) {
goto cleanup;
}
}
/*
* 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);
cleanup:
/* On error, must release the method mutex (if present) */
if (obj_desc->method.mutex) {
acpi_os_release_mutex(obj_desc->method.mutex->mutex.os_mutex);
}
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_evaluate_info *info;
u32 i;
ACPI_FUNCTION_TRACE_PTR(ds_call_control_method, this_walk_state);
ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
"Calling 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, possibly wait on method mutex */
status = acpi_ds_begin_method_execution(method_node, obj_desc,
this_walk_state);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
/* Begin method parse/execution. Create a new walk state */
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;
/*
* Allocate and initialize the evaluation information block
* TBD: this is somewhat inefficient, should change interface to
* ds_init_aml_walk. For now, keeps this struct off the CPU stack
*/
info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
if (!info) {
status = AE_NO_MEMORY;
goto cleanup;
}
info->parameters = &this_walk_state->operands[0];
status = acpi_ds_init_aml_walk(next_walk_state, NULL, method_node,
obj_desc->method.aml_start,
obj_desc->method.aml_length, info,
ACPI_IMODE_EXECUTE);
ACPI_FREE(info);
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,
"**** Begin nested execution of [%4.4s] **** WalkState=%p\n",
method_node->name.ascii, next_walk_state));
/* Invoke an internal method if necessary */
if (obj_desc->method.info_flags & ACPI_METHOD_INTERNAL_ONLY) {
status =
obj_desc->method.dispatch.implementation(next_walk_state);
if (status == AE_OK) {
status = AE_CTRL_TERMINATE;
}
}
return_ACPI_STATUS(status);
cleanup:
/* On error, we must terminate the method properly */
acpi_ds_terminate_control_method(obj_desc, next_walk_state);
if (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;
int same_as_implicit_return;
ACPI_FUNCTION_TRACE_PTR(ds_restart_control_method, walk_state);
ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
"****Restart [%4.4s] Op %p ReturnValueFromCallee %p\n",
acpi_ut_get_node_name(walk_state->method_node),
walk_state->method_call_op, return_desc));
ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
" ReturnFromThisMethodUsed?=%X ResStack %p Walk %p\n",
walk_state->return_used,
walk_state->results, walk_state));
/* Did the called method return a value? */
if (return_desc) {
/* Is the implicit return object the same as the return desc? */
same_as_implicit_return =
(walk_state->implicit_return_obj == 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 the so-called
* "implicit return". Some AML code assumes that the last value of the
* method is "implicitly" returned to the caller, in the absence of an
* explicit return value.
*
* Just save the last result of the method 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)
|| same_as_implicit_return) {
/*
* Delete the return value if it will not be used by the
* calling method or remove one reference if the explicit return
* is the same as the implicit return value.
*/
acpi_ut_remove_reference(return_desc);
}
}
return_ACPI_STATUS(AE_OK);
}
/*******************************************************************************
*
* FUNCTION: acpi_ds_terminate_control_method
*
* PARAMETERS: method_desc - Method object
* walk_state - State associated with 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.
*
* MUTEX: Interpreter is locked
*
******************************************************************************/
void
acpi_ds_terminate_control_method(union acpi_operand_object *method_desc,
struct acpi_walk_state *walk_state)
{
ACPI_FUNCTION_TRACE_PTR(ds_terminate_control_method, walk_state);
/* method_desc is required, walk_state is optional */
if (!method_desc) {
return_VOID;
}
if (walk_state) {
/* Delete all arguments and locals */
acpi_ds_method_data_delete_all(walk_state);
/*
* If method is serialized, release the mutex and restore the
* current sync level for this thread
*/
if (method_desc->method.mutex) {
/* Acquisition Depth handles recursive calls */
method_desc->method.mutex->mutex.acquisition_depth--;
if (!method_desc->method.mutex->mutex.acquisition_depth) {
walk_state->thread->current_sync_level =
method_desc->method.mutex->mutex.
original_sync_level;
acpi_os_release_mutex(method_desc->method.
mutex->mutex.os_mutex);
method_desc->method.mutex->mutex.thread_id = 0;
}
}
/*
* Delete any namespace objects created anywhere within the
* namespace by the execution of this method. Unless:
* 1) This method is a module-level executable code method, in which
* case we want make the objects permanent.
* 2) There are other threads executing the method, in which case we
* will wait until the last thread has completed.
*/
if (!(method_desc->method.info_flags & ACPI_METHOD_MODULE_LEVEL)
&& (method_desc->method.thread_count == 1)) {
/* Delete any direct children of (created by) this method */
acpi_ns_delete_namespace_subtree(walk_state->
method_node);
/*
* Delete any objects that were created by this method
* elsewhere in the namespace (if any were created).
* Use of the ACPI_METHOD_MODIFIED_NAMESPACE optimizes the
* deletion such that we don't have to perform an entire
* namespace walk for every control method execution.
*/
if (method_desc->method.
info_flags & ACPI_METHOD_MODIFIED_NAMESPACE) {
acpi_ns_delete_namespace_by_owner(method_desc->
method.
owner_id);
method_desc->method.info_flags &=
~ACPI_METHOD_MODIFIED_NAMESPACE;
}
}
}
/* Decrement the thread count on the method */
if (method_desc->method.thread_count) {
method_desc->method.thread_count--;
} else {
ACPI_ERROR((AE_INFO, "Invalid zero thread count in method"));
}
/* Are there any other threads currently executing this method? */
if (method_desc->method.thread_count) {
/*
* Additional threads. Do not release the owner_id in this case,
* we immediately reuse it for the next thread executing this method
*/
ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
"*** Completed execution of one thread, %u threads remaining\n",
method_desc->method.thread_count));
} else {
/* This is the only executing thread for this method */
/*
* Support to dynamically change a method from not_serialized to
* Serialized if it appears that the method is incorrectly written 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 marking the method as serialized.
*/
if (method_desc->method.
info_flags & ACPI_METHOD_SERIALIZED_PENDING) {
if (walk_state) {
ACPI_INFO((AE_INFO,
"Marking method %4.4s as Serialized because of AE_ALREADY_EXISTS error",
walk_state->method_node->name.
ascii));
}
/*
* Method tried to create an object twice and was marked as
* "pending serialized". The probable cause is that the method
* cannot handle reentrancy.
*
* The method was created as not_serialized, but it tried to create
* a named object and then blocked, causing the second thread
* entrance to begin and then fail. Workaround this problem by
* marking the method permanently as Serialized when the last
* thread exits here.
*/
method_desc->method.info_flags &=
~ACPI_METHOD_SERIALIZED_PENDING;
method_desc->method.info_flags |=
ACPI_METHOD_SERIALIZED;
method_desc->method.sync_level = 0;
}
/* No more threads, we can free the owner_id */
if (!
(method_desc->method.
info_flags & ACPI_METHOD_MODULE_LEVEL)) {
acpi_ut_release_owner_id(&method_desc->method.owner_id);
}
}
return_VOID;
}
