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/******************************************************************************
*
* Module Name: exmutex - ASL Mutex Acquire/Release functions
* $Revision: 7 $
*
*****************************************************************************/
/*
* Copyright (C) 2000, 2001 R. Byron Moore
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "acpi.h"
#include "acinterp.h"
#include "acnamesp.h"
#include "achware.h"
#include "acevents.h"
#define _COMPONENT ACPI_EXECUTER
MODULE_NAME ("exmutex")
/*******************************************************************************
*
* FUNCTION: Acpi_ex_unlink_mutex
*
* PARAMETERS: *Obj_desc - The mutex to be unlinked
*
* RETURN: Status
*
* DESCRIPTION: Remove a mutex from the "Acquired_mutex" list
*
******************************************************************************/
void
acpi_ex_unlink_mutex (
acpi_operand_object *obj_desc)
{
if (obj_desc->mutex.next) {
(obj_desc->mutex.next)->mutex.prev = obj_desc->mutex.prev;
}
if (obj_desc->mutex.prev) {
(obj_desc->mutex.prev)->mutex.next = obj_desc->mutex.next;
}
}
/*******************************************************************************
*
* FUNCTION: Acpi_ex_link_mutex
*
* PARAMETERS: *Obj_desc - The mutex to be linked
* *List_head - head of the "Acquired_mutex" list
*
* RETURN: Status
*
* DESCRIPTION: Add a mutex to the "Acquired_mutex" list for this walk
*
******************************************************************************/
void
acpi_ex_link_mutex (
acpi_operand_object *obj_desc,
acpi_operand_object *list_head)
{
/* This object will be the first object in the list */
obj_desc->mutex.prev = list_head;
obj_desc->mutex.next = list_head->mutex.next;
/* Update old first object to point back to this object */
if (list_head->mutex.next) {
(list_head->mutex.next)->mutex.prev = obj_desc;
}
/* Update list head */
list_head->mutex.next = obj_desc;
}
/*******************************************************************************
*
* FUNCTION: Acpi_ex_acquire_mutex
*
* PARAMETERS: *Time_desc - The 'time to delay' object descriptor
* *Obj_desc - The object descriptor for this op
*
* RETURN: Status
*
* DESCRIPTION: Acquire an AML mutex
*
******************************************************************************/
acpi_status
acpi_ex_acquire_mutex (
acpi_operand_object *time_desc,
acpi_operand_object *obj_desc,
acpi_walk_state *walk_state)
{
acpi_status status;
FUNCTION_TRACE_PTR ("Ex_acquire_mutex", obj_desc);
if (!obj_desc) {
return_ACPI_STATUS (AE_BAD_PARAMETER);
}
/*
* Current Sync must be less than or equal to the sync level of the
* mutex. This mechanism provides some deadlock prevention
*/
if (walk_state->current_sync_level > obj_desc->mutex.sync_level) {
return_ACPI_STATUS (AE_AML_MUTEX_ORDER);
}
/*
* If the mutex is already owned by this thread,
* just increment the acquisition depth
*/
if (obj_desc->mutex.owner == walk_state) {
obj_desc->mutex.acquisition_depth++;
return_ACPI_STATUS (AE_OK);
}
/* Acquire the mutex, wait if necessary */
status = acpi_ex_system_acquire_mutex (time_desc, obj_desc);
if (ACPI_FAILURE (status)) {
/* Includes failure from a timeout on Time_desc */
return_ACPI_STATUS (status);
}
/* Have the mutex, update mutex and walk info */
obj_desc->mutex.owner = walk_state;
obj_desc->mutex.acquisition_depth = 1;
walk_state->current_sync_level = obj_desc->mutex.sync_level;
/* Link the mutex to the walk state for force-unlock at method exit */
acpi_ex_link_mutex (obj_desc, (acpi_operand_object *)
&(walk_state->walk_list->acquired_mutex_list));
return_ACPI_STATUS (AE_OK);
}
/*******************************************************************************
*
* FUNCTION: Acpi_ex_release_mutex
*
* PARAMETERS: *Obj_desc - The object descriptor for this op
*
* RETURN: Status
*
* DESCRIPTION: Release a previously acquired Mutex.
*
******************************************************************************/
acpi_status
acpi_ex_release_mutex (
acpi_operand_object *obj_desc,
acpi_walk_state *walk_state)
{
acpi_status status;
FUNCTION_TRACE ("Ex_release_mutex");
if (!obj_desc) {
return_ACPI_STATUS (AE_BAD_PARAMETER);
}
/* The mutex must have been previously acquired in order to release it */
if (!obj_desc->mutex.owner) {
return_ACPI_STATUS (AE_AML_MUTEX_NOT_ACQUIRED);
}
/* The Mutex is owned, but this thread must be the owner */
if (obj_desc->mutex.owner != walk_state) {
return_ACPI_STATUS (AE_AML_NOT_OWNER);
}
/*
* The sync level of the mutex must be less than or
* equal to the current sync level
*/
if (obj_desc->mutex.sync_level > walk_state->current_sync_level) {
return_ACPI_STATUS (AE_AML_MUTEX_ORDER);
}
/*
* Match multiple Acquires with multiple Releases
*/
obj_desc->mutex.acquisition_depth--;
if (obj_desc->mutex.acquisition_depth != 0) {
/* Just decrement the depth and return */
return_ACPI_STATUS (AE_OK);
}
/* Release the mutex */
status = acpi_ex_system_release_mutex (obj_desc);
/* Update the mutex and walk state */
obj_desc->mutex.owner = NULL;
walk_state->current_sync_level = obj_desc->mutex.sync_level;
/* Unlink the mutex from the owner's list */
acpi_ex_unlink_mutex (obj_desc);
return_ACPI_STATUS (status);
}
/*******************************************************************************
*
* FUNCTION: Acpi_ex_release_all_mutexes
*
* PARAMETERS: *Mutex_list - Head of the mutex list
*
* RETURN: Status
*
* DESCRIPTION: Release all mutexes in the list
*
******************************************************************************/
acpi_status
acpi_ex_release_all_mutexes (
acpi_operand_object *list_head)
{
acpi_operand_object *next = list_head->mutex.next;
acpi_operand_object *this;
FUNCTION_ENTRY ();
/*
* Traverse the list of owned mutexes, releasing each one.
*/
while (next) {
this = next;
next = this->mutex.next;
/* Mark mutex un-owned */
this->mutex.owner = NULL;
this->mutex.prev = NULL;
this->mutex.next = NULL;
this->mutex.acquisition_depth = 0;
/* Release the mutex */
acpi_ex_system_release_mutex (this);
}
return (AE_OK);
}
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