linux/drivers/acpi/executer/exmutex.c
Bob Moore c81da66608 ACPICA: Delete recursive feature of ACPI Global Lock
Completed a new design and implementation for
the ACPI Global Lock support. On the OS side, the global
lock is now treated as a standard AML mutex. Previously,
multiple OS threads could acquire the global lock
simultaneously, but this could cause the BIOS to be starved
by the lock in cases such as the Embedded Controller driver,
where there is a tight coupling between the OS and the BIOS.

Signed-off-by: Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
2007-02-02 21:14:20 -05:00

372 lines
11 KiB
C

/******************************************************************************
*
* Module Name: exmutex - ASL Mutex Acquire/Release functions
*
*****************************************************************************/
/*
* Copyright (C) 2000 - 2006, 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/acinterp.h>
#include <acpi/acevents.h>
#define _COMPONENT ACPI_EXECUTER
ACPI_MODULE_NAME("exmutex")
/* Local prototypes */
static void
acpi_ex_link_mutex(union acpi_operand_object *obj_desc,
struct acpi_thread_state *thread);
/*******************************************************************************
*
* FUNCTION: acpi_ex_unlink_mutex
*
* PARAMETERS: obj_desc - The mutex to be unlinked
*
* RETURN: None
*
* DESCRIPTION: Remove a mutex from the "AcquiredMutex" list
*
******************************************************************************/
void acpi_ex_unlink_mutex(union acpi_operand_object *obj_desc)
{
struct acpi_thread_state *thread = obj_desc->mutex.owner_thread;
if (!thread) {
return;
}
/* Doubly linked list */
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;
} else {
thread->acquired_mutex_list = obj_desc->mutex.next;
}
}
/*******************************************************************************
*
* FUNCTION: acpi_ex_link_mutex
*
* PARAMETERS: obj_desc - The mutex to be linked
* Thread - Current executing thread object
*
* RETURN: None
*
* DESCRIPTION: Add a mutex to the "AcquiredMutex" list for this walk
*
******************************************************************************/
static void
acpi_ex_link_mutex(union acpi_operand_object *obj_desc,
struct acpi_thread_state *thread)
{
union acpi_operand_object *list_head;
list_head = thread->acquired_mutex_list;
/* This object will be the first object in the list */
obj_desc->mutex.prev = NULL;
obj_desc->mutex.next = list_head;
/* Update old first object to point back to this object */
if (list_head) {
list_head->mutex.prev = obj_desc;
}
/* Update list head */
thread->acquired_mutex_list = obj_desc;
}
/*******************************************************************************
*
* FUNCTION: acpi_ex_acquire_mutex
*
* PARAMETERS: time_desc - Timeout integer
* obj_desc - Mutex object
* walk_state - Current method execution state
*
* RETURN: Status
*
* DESCRIPTION: Acquire an AML mutex
*
******************************************************************************/
acpi_status
acpi_ex_acquire_mutex(union acpi_operand_object *time_desc,
union acpi_operand_object *obj_desc,
struct acpi_walk_state *walk_state)
{
acpi_status status;
ACPI_FUNCTION_TRACE_PTR(ex_acquire_mutex, obj_desc);
if (!obj_desc) {
return_ACPI_STATUS(AE_BAD_PARAMETER);
}
/* Sanity check: we must have a valid thread ID */
if (!walk_state->thread) {
ACPI_ERROR((AE_INFO,
"Cannot acquire Mutex [%4.4s], null thread info",
acpi_ut_get_node_name(obj_desc->mutex.node)));
return_ACPI_STATUS(AE_AML_INTERNAL);
}
/*
* Current Sync must be less than or equal to the sync level of the
* mutex. This mechanism provides some deadlock prevention
*/
if (walk_state->thread->current_sync_level > obj_desc->mutex.sync_level) {
ACPI_ERROR((AE_INFO,
"Cannot acquire Mutex [%4.4s], current SyncLevel is too large (%d)",
acpi_ut_get_node_name(obj_desc->mutex.node),
walk_state->thread->current_sync_level));
return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
}
/* Support for multiple acquires by the owning thread */
if (obj_desc->mutex.owner_thread) {
if (obj_desc->mutex.owner_thread->thread_id ==
walk_state->thread->thread_id) {
/*
* The mutex is already owned by this thread, just increment the
* acquisition depth
*/
obj_desc->mutex.acquisition_depth++;
return_ACPI_STATUS(AE_OK);
}
}
/* Acquire the mutex, wait if necessary. Special case for Global Lock */
if (obj_desc->mutex.os_mutex == acpi_gbl_global_lock_mutex) {
status =
acpi_ev_acquire_global_lock((u16) time_desc->integer.value);
} else {
status = acpi_ex_system_wait_mutex(obj_desc->mutex.os_mutex,
(u16) time_desc->integer.
value);
}
if (ACPI_FAILURE(status)) {
/* Includes failure from a timeout on time_desc */
return_ACPI_STATUS(status);
}
/* Have the mutex: update mutex and walk info and save the sync_level */
obj_desc->mutex.owner_thread = walk_state->thread;
obj_desc->mutex.acquisition_depth = 1;
obj_desc->mutex.original_sync_level =
walk_state->thread->current_sync_level;
walk_state->thread->current_sync_level = obj_desc->mutex.sync_level;
/* Link the mutex to the current thread for force-unlock at method exit */
acpi_ex_link_mutex(obj_desc, walk_state->thread);
return_ACPI_STATUS(AE_OK);
}
/*******************************************************************************
*
* FUNCTION: acpi_ex_release_mutex
*
* PARAMETERS: obj_desc - The object descriptor for this op
* walk_state - Current method execution state
*
* RETURN: Status
*
* DESCRIPTION: Release a previously acquired Mutex.
*
******************************************************************************/
acpi_status
acpi_ex_release_mutex(union acpi_operand_object *obj_desc,
struct acpi_walk_state *walk_state)
{
acpi_status status = AE_OK;
ACPI_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_thread) {
ACPI_ERROR((AE_INFO,
"Cannot release Mutex [%4.4s], not acquired",
acpi_ut_get_node_name(obj_desc->mutex.node)));
return_ACPI_STATUS(AE_AML_MUTEX_NOT_ACQUIRED);
}
/* Sanity check: we must have a valid thread ID */
if (!walk_state->thread) {
ACPI_ERROR((AE_INFO,
"Cannot release Mutex [%4.4s], null thread info",
acpi_ut_get_node_name(obj_desc->mutex.node)));
return_ACPI_STATUS(AE_AML_INTERNAL);
}
/*
* The Mutex is owned, but this thread must be the owner.
* Special case for Global Lock, any thread can release
*/
if ((obj_desc->mutex.owner_thread->thread_id !=
walk_state->thread->thread_id)
&& (obj_desc->mutex.os_mutex != acpi_gbl_global_lock_mutex)) {
ACPI_ERROR((AE_INFO,
"Thread %lX cannot release Mutex [%4.4s] acquired by thread %lX",
(unsigned long)walk_state->thread->thread_id,
acpi_ut_get_node_name(obj_desc->mutex.node),
(unsigned long)obj_desc->mutex.owner_thread->thread_id));
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->thread->current_sync_level) {
ACPI_ERROR((AE_INFO,
"Cannot release Mutex [%4.4s], incorrect SyncLevel",
acpi_ut_get_node_name(obj_desc->mutex.node)));
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);
}
/* Unlink the mutex from the owner's list */
acpi_ex_unlink_mutex(obj_desc);
/* Release the mutex, special case for Global Lock */
if (obj_desc->mutex.os_mutex == acpi_gbl_global_lock_mutex) {
status = acpi_ev_release_global_lock();
} else {
acpi_os_release_mutex(obj_desc->mutex.os_mutex);
}
/* Update the mutex and restore sync_level */
obj_desc->mutex.owner_thread = NULL;
walk_state->thread->current_sync_level =
obj_desc->mutex.original_sync_level;
return_ACPI_STATUS(status);
}
/*******************************************************************************
*
* FUNCTION: acpi_ex_release_all_mutexes
*
* PARAMETERS: Thread - Current executing thread object
*
* RETURN: Status
*
* DESCRIPTION: Release all mutexes held by this thread
*
******************************************************************************/
void acpi_ex_release_all_mutexes(struct acpi_thread_state *thread)
{
union acpi_operand_object *next = thread->acquired_mutex_list;
union acpi_operand_object *obj_desc;
ACPI_FUNCTION_ENTRY();
/* Traverse the list of owned mutexes, releasing each one */
while (next) {
obj_desc = next;
next = obj_desc->mutex.next;
obj_desc->mutex.prev = NULL;
obj_desc->mutex.next = NULL;
obj_desc->mutex.acquisition_depth = 1;
/* Release the mutex, special case for Global Lock */
if (obj_desc->mutex.os_mutex == acpi_gbl_global_lock_mutex) {
/* Ignore errors */
(void)acpi_ev_release_global_lock();
} else {
acpi_os_release_mutex(obj_desc->mutex.os_mutex);
}
/* Mark mutex unowned */
obj_desc->mutex.owner_thread = NULL;
/* Update Thread sync_level (Last mutex is the important one) */
thread->current_sync_level =
obj_desc->mutex.original_sync_level;
}
}