/******************************************************************************
*
* Module Name: evxface - External interfaces for ACPI events
*
*****************************************************************************/
/*
* Copyright (C) 2000 - 2008, 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 "acnamesp.h"
#include "acevents.h"
#include "acinterp.h"
#define _COMPONENT ACPI_EVENTS
ACPI_MODULE_NAME("evxface")
/*******************************************************************************
*
* FUNCTION: acpi_install_exception_handler
*
* PARAMETERS: Handler - Pointer to the handler function for the
* event
*
* RETURN: Status
*
* DESCRIPTION: Saves the pointer to the handler function
*
******************************************************************************/
#ifdef ACPI_FUTURE_USAGE
acpi_status acpi_install_exception_handler(acpi_exception_handler handler)
{
acpi_status status;
ACPI_FUNCTION_TRACE(acpi_install_exception_handler);
status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
/* Don't allow two handlers. */
if (acpi_gbl_exception_handler) {
status = AE_ALREADY_EXISTS;
goto cleanup;
}
/* Install the handler */
acpi_gbl_exception_handler = handler;
cleanup:
(void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
return_ACPI_STATUS(status);
}
ACPI_EXPORT_SYMBOL(acpi_install_exception_handler)
#endif /* ACPI_FUTURE_USAGE */
/*******************************************************************************
*
* FUNCTION: acpi_install_fixed_event_handler
*
* PARAMETERS: Event - Event type to enable.
* Handler - Pointer to the handler function for the
* event
* Context - Value passed to the handler on each GPE
*
* RETURN: Status
*
* DESCRIPTION: Saves the pointer to the handler function and then enables the
* event.
*
******************************************************************************/
acpi_status
acpi_install_fixed_event_handler(u32 event,
acpi_event_handler handler, void *context)
{
acpi_status status;
ACPI_FUNCTION_TRACE(acpi_install_fixed_event_handler);
/* Parameter validation */
if (event > ACPI_EVENT_MAX) {
return_ACPI_STATUS(AE_BAD_PARAMETER);
}
status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
/* Don't allow two handlers. */
if (NULL != acpi_gbl_fixed_event_handlers[event].handler) {
status = AE_ALREADY_EXISTS;
goto cleanup;
}
/* Install the handler before enabling the event */
acpi_gbl_fixed_event_handlers[event].handler = handler;
acpi_gbl_fixed_event_handlers[event].context = context;
status = acpi_clear_event(event);
if (ACPI_SUCCESS(status))
status = acpi_enable_event(event, 0);
if (ACPI_FAILURE(status)) {
ACPI_WARNING((AE_INFO, "Could not enable fixed event %X",
event));
/* Remove the handler */
acpi_gbl_fixed_event_handlers[event].handler = NULL;
acpi_gbl_fixed_event_handlers[event].context = NULL;
} else {
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Enabled fixed event %X, Handler=%p\n", event,
handler));
}
cleanup:
(void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
return_ACPI_STATUS(status);
}
ACPI_EXPORT_SYMBOL(acpi_install_fixed_event_handler)
/*******************************************************************************
*
* FUNCTION: acpi_remove_fixed_event_handler
*
* PARAMETERS: Event - Event type to disable.
* Handler - Address of the handler
*
* RETURN: Status
*
* DESCRIPTION: Disables the event and unregisters the event handler.
*
******************************************************************************/
acpi_status
acpi_remove_fixed_event_handler(u32 event, acpi_event_handler handler)
{
acpi_status status = AE_OK;
ACPI_FUNCTION_TRACE(acpi_remove_fixed_event_handler);
/* Parameter validation */
if (event > ACPI_EVENT_MAX) {
return_ACPI_STATUS(AE_BAD_PARAMETER);
}
status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
/* Disable the event before removing the handler */
status = acpi_disable_event(event, 0);
/* Always Remove the handler */
acpi_gbl_fixed_event_handlers[event].handler = NULL;
acpi_gbl_fixed_event_handlers[event].context = NULL;
if (ACPI_FAILURE(status)) {
ACPI_WARNING((AE_INFO,
"Could not write to fixed event enable register %X",
event));
} else {
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Disabled fixed event %X\n",
event));
}
(void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
return_ACPI_STATUS(status);
}
ACPI_EXPORT_SYMBOL(acpi_remove_fixed_event_handler)
/*******************************************************************************
*
* FUNCTION: acpi_install_notify_handler
*
* PARAMETERS: Device - The device for which notifies will be handled
* handler_type - The type of handler:
* ACPI_SYSTEM_NOTIFY: system_handler (00-7f)
* ACPI_DEVICE_NOTIFY: driver_handler (80-ff)
* ACPI_ALL_NOTIFY: both system and device
* Handler - Address of the handler
* Context - Value passed to the handler on each GPE
*
* RETURN: Status
*
* DESCRIPTION: Install a handler for notifies on an ACPI device
*
******************************************************************************/
acpi_status
acpi_install_notify_handler(acpi_handle device,
u32 handler_type,
acpi_notify_handler handler, void *context)
{
union acpi_operand_object *obj_desc;
union acpi_operand_object *notify_obj;
struct acpi_namespace_node *node;
acpi_status status;
ACPI_FUNCTION_TRACE(acpi_install_notify_handler);
/* Parameter validation */
if ((!device) ||
(!handler) || (handler_type > ACPI_MAX_NOTIFY_HANDLER_TYPE)) {
return_ACPI_STATUS(AE_BAD_PARAMETER);
}
status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
/* Convert and validate the device handle */
node = acpi_ns_validate_handle(device);
if (!node) {
status = AE_BAD_PARAMETER;
goto unlock_and_exit;
}
/*
* Root Object:
* Registering a notify handler on the root object indicates that the
* caller wishes to receive notifications for all objects. Note that
* only one <external> global handler can be regsitered (per notify type).
*/
if (device == ACPI_ROOT_OBJECT) {
/* Make sure the handler is not already installed */
if (((handler_type & ACPI_SYSTEM_NOTIFY) &&
acpi_gbl_system_notify.handler) ||
((handler_type & ACPI_DEVICE_NOTIFY) &&
acpi_gbl_device_notify.handler)) {
status = AE_ALREADY_EXISTS;
goto unlock_and_exit;
}
if (handler_type & ACPI_SYSTEM_NOTIFY) {
acpi_gbl_system_notify.node = node;
acpi_gbl_system_notify.handler = handler;
acpi_gbl_system_notify.context = context;
}
if (handler_type & ACPI_DEVICE_NOTIFY) {
acpi_gbl_device_notify.node = node;
acpi_gbl_device_notify.handler = handler;
acpi_gbl_device_notify.context = context;
}
/* Global notify handler installed */
}
/*
* All Other Objects:
* Caller will only receive notifications specific to the target object.
* Note that only certain object types can receive notifications.
*/
else {
/* Notifies allowed on this object? */
if (!acpi_ev_is_notify_object(node)) {
status = AE_TYPE;
goto unlock_and_exit;
}
/* Check for an existing internal object */
obj_desc = acpi_ns_get_attached_object(node);
if (obj_desc) {
/* Object exists - make sure there's no handler */
if (((handler_type & ACPI_SYSTEM_NOTIFY) &&
obj_desc->common_notify.system_notify) ||
((handler_type & ACPI_DEVICE_NOTIFY) &&
obj_desc->common_notify.device_notify)) {
status = AE_ALREADY_EXISTS;
goto unlock_and_exit;
}
} else {
/* Create a new object */
obj_desc = acpi_ut_create_internal_object(node->type);
if (!obj_desc) {
status = AE_NO_MEMORY;
goto unlock_and_exit;
}
/* Attach new object to the Node */
status =
acpi_ns_attach_object(device, obj_desc, node->type);
/* Remove local reference to the object */
acpi_ut_remove_reference(obj_desc);
if (ACPI_FAILURE(status)) {
goto unlock_and_exit;
}
}
/* Install the handler */
notify_obj =
acpi_ut_create_internal_object(ACPI_TYPE_LOCAL_NOTIFY);
if (!notify_obj) {
status = AE_NO_MEMORY;
goto unlock_and_exit;
}
notify_obj->notify.node = node;
notify_obj->notify.handler = handler;
notify_obj->notify.context = context;
if (handler_type & ACPI_SYSTEM_NOTIFY) {
obj_desc->common_notify.system_notify = notify_obj;
}
if (handler_type & ACPI_DEVICE_NOTIFY) {
obj_desc->common_notify.device_notify = notify_obj;
}
if (handler_type == ACPI_ALL_NOTIFY) {
/* Extra ref if installed in both */
acpi_ut_add_reference(notify_obj);
}
}
unlock_and_exit:
(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
return_ACPI_STATUS(status);
}
ACPI_EXPORT_SYMBOL(acpi_install_notify_handler)
/*******************************************************************************
*
* FUNCTION: acpi_remove_notify_handler
*
* PARAMETERS: Device - The device for which notifies will be handled
* handler_type - The type of handler:
* ACPI_SYSTEM_NOTIFY: system_handler (00-7f)
* ACPI_DEVICE_NOTIFY: driver_handler (80-ff)
* ACPI_ALL_NOTIFY: both system and device
* Handler - Address of the handler
*
* RETURN: Status
*
* DESCRIPTION: Remove a handler for notifies on an ACPI device
*
******************************************************************************/
acpi_status
acpi_remove_notify_handler(acpi_handle device,
u32 handler_type, acpi_notify_handler handler)
{
union acpi_operand_object *notify_obj;
union acpi_operand_object *obj_desc;
struct acpi_namespace_node *node;
acpi_status status;
ACPI_FUNCTION_TRACE(acpi_remove_notify_handler);
/* Parameter validation */
if ((!device) ||
(!handler) || (handler_type > ACPI_MAX_NOTIFY_HANDLER_TYPE)) {
status = AE_BAD_PARAMETER;
goto exit;
}
status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
if (ACPI_FAILURE(status)) {
goto exit;
}
/* Convert and validate the device handle */
node = acpi_ns_validate_handle(device);
if (!node) {
status = AE_BAD_PARAMETER;
goto unlock_and_exit;
}
/* Root Object */
if (device == ACPI_ROOT_OBJECT) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Removing notify handler for namespace root object\n"));
if (((handler_type & ACPI_SYSTEM_NOTIFY) &&
!acpi_gbl_system_notify.handler) ||
((handler_type & ACPI_DEVICE_NOTIFY) &&
!acpi_gbl_device_notify.handler)) {
status = AE_NOT_EXIST;
goto unlock_and_exit;
}
/* Make sure all deferred tasks are completed */
(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
acpi_os_wait_events_complete(NULL);
status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
if (ACPI_FAILURE(status)) {
goto exit;
}
if (handler_type & ACPI_SYSTEM_NOTIFY) {
acpi_gbl_system_notify.node = NULL;
acpi_gbl_system_notify.handler = NULL;
acpi_gbl_system_notify.context = NULL;
}
if (handler_type & ACPI_DEVICE_NOTIFY) {
acpi_gbl_device_notify.node = NULL;
acpi_gbl_device_notify.handler = NULL;
acpi_gbl_device_notify.context = NULL;
}
}
/* All Other Objects */
else {
/* Notifies allowed on this object? */
if (!acpi_ev_is_notify_object(node)) {
status = AE_TYPE;
goto unlock_and_exit;
}
/* Check for an existing internal object */
obj_desc = acpi_ns_get_attached_object(node);
if (!obj_desc) {
status = AE_NOT_EXIST;
goto unlock_and_exit;
}
/* Object exists - make sure there's an existing handler */
if (handler_type & ACPI_SYSTEM_NOTIFY) {
notify_obj = obj_desc->common_notify.system_notify;
if (!notify_obj) {
status = AE_NOT_EXIST;
goto unlock_and_exit;
}
if (notify_obj->notify.handler != handler) {
status = AE_BAD_PARAMETER;
goto unlock_and_exit;
}
/* Make sure all deferred tasks are completed */
(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
acpi_os_wait_events_complete(NULL);
status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
if (ACPI_FAILURE(status)) {
goto exit;
}
/* Remove the handler */
obj_desc->common_notify.system_notify = NULL;
acpi_ut_remove_reference(notify_obj);
}
if (handler_type & ACPI_DEVICE_NOTIFY) {
notify_obj = obj_desc->common_notify.device_notify;
if (!notify_obj) {
status = AE_NOT_EXIST;
goto unlock_and_exit;
}
if (notify_obj->notify.handler != handler) {
status = AE_BAD_PARAMETER;
goto unlock_and_exit;
}
/* Make sure all deferred tasks are completed */
(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
acpi_os_wait_events_complete(NULL);
status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
if (ACPI_FAILURE(status)) {
goto exit;
}
/* Remove the handler */
obj_desc->common_notify.device_notify = NULL;
acpi_ut_remove_reference(notify_obj);
}
}
unlock_and_exit:
(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
exit:
if (ACPI_FAILURE(status))
ACPI_EXCEPTION((AE_INFO, status, "Removing notify handler"));
return_ACPI_STATUS(status);
}
ACPI_EXPORT_SYMBOL(acpi_remove_notify_handler)
/*******************************************************************************
*
* FUNCTION: acpi_install_gpe_handler
*
* PARAMETERS: gpe_device - Namespace node for the GPE (NULL for FADT
* defined GPEs)
* gpe_number - The GPE number within the GPE block
* Type - Whether this GPE should be treated as an
* edge- or level-triggered interrupt.
* Address - Address of the handler
* Context - Value passed to the handler on each GPE
*
* RETURN: Status
*
* DESCRIPTION: Install a handler for a General Purpose Event.
*
******************************************************************************/
acpi_status
acpi_install_gpe_handler(acpi_handle gpe_device,
u32 gpe_number,
u32 type, acpi_event_handler address, void *context)
{
struct acpi_gpe_event_info *gpe_event_info;
struct acpi_handler_info *handler;
acpi_status status;
acpi_cpu_flags flags;
ACPI_FUNCTION_TRACE(acpi_install_gpe_handler);
/* Parameter validation */
if ((!address) || (type > ACPI_GPE_XRUPT_TYPE_MASK)) {
status = AE_BAD_PARAMETER;
goto exit;
}
status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
if (ACPI_FAILURE(status)) {
goto exit;
}
/* Ensure that we have a valid GPE number */
gpe_event_info = acpi_ev_get_gpe_event_info(gpe_device, gpe_number);
if (!gpe_event_info) {
status = AE_BAD_PARAMETER;
goto unlock_and_exit;
}
/* Make sure that there isn't a handler there already */
if ((gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) ==
ACPI_GPE_DISPATCH_HANDLER) {
status = AE_ALREADY_EXISTS;
goto unlock_and_exit;
}
/* Allocate and init handler object */
handler = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_handler_info));
if (!handler) {
status = AE_NO_MEMORY;
goto unlock_and_exit;
}
handler->address = address;
handler->context = context;
handler->method_node = gpe_event_info->dispatch.method_node;
/* Disable the GPE before installing the handler */
status = acpi_ev_disable_gpe(gpe_event_info);
if (ACPI_FAILURE(status)) {
goto unlock_and_exit;
}
/* Install the handler */
flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
gpe_event_info->dispatch.handler = handler;
/* Setup up dispatch flags to indicate handler (vs. method) */
gpe_event_info->flags &=
~(ACPI_GPE_XRUPT_TYPE_MASK | ACPI_GPE_DISPATCH_MASK);
gpe_event_info->flags |= (u8) (type | ACPI_GPE_DISPATCH_HANDLER);
acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
unlock_and_exit:
(void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
exit:
if (ACPI_FAILURE(status))
ACPI_EXCEPTION((AE_INFO, status,
"Installing notify handler failed"));
return_ACPI_STATUS(status);
}
ACPI_EXPORT_SYMBOL(acpi_install_gpe_handler)
/*******************************************************************************
*
* FUNCTION: acpi_remove_gpe_handler
*
* PARAMETERS: gpe_device - Namespace node for the GPE (NULL for FADT
* defined GPEs)
* gpe_number - The event to remove a handler
* Address - Address of the handler
*
* RETURN: Status
*
* DESCRIPTION: Remove a handler for a General Purpose acpi_event.
*
******************************************************************************/
acpi_status
acpi_remove_gpe_handler(acpi_handle gpe_device,
u32 gpe_number, acpi_event_handler address)
{
struct acpi_gpe_event_info *gpe_event_info;
struct acpi_handler_info *handler;
acpi_status status;
acpi_cpu_flags flags;
ACPI_FUNCTION_TRACE(acpi_remove_gpe_handler);
/* Parameter validation */
if (!address) {
return_ACPI_STATUS(AE_BAD_PARAMETER);
}
status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
/* Ensure that we have a valid GPE number */
gpe_event_info = acpi_ev_get_gpe_event_info(gpe_device, gpe_number);
if (!gpe_event_info) {
status = AE_BAD_PARAMETER;
goto unlock_and_exit;
}
/* Make sure that a handler is indeed installed */
if ((gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) !=
ACPI_GPE_DISPATCH_HANDLER) {
status = AE_NOT_EXIST;
goto unlock_and_exit;
}
/* Make sure that the installed handler is the same */
if (gpe_event_info->dispatch.handler->address != address) {
status = AE_BAD_PARAMETER;
goto unlock_and_exit;
}
/* Disable the GPE before removing the handler */
status = acpi_ev_disable_gpe(gpe_event_info);
if (ACPI_FAILURE(status)) {
goto unlock_and_exit;
}
/* Make sure all deferred tasks are completed */
(void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
acpi_os_wait_events_complete(NULL);
status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
/* Remove the handler */
flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
handler = gpe_event_info->dispatch.handler;
/* Restore Method node (if any), set dispatch flags */
gpe_event_info->dispatch.method_node = handler->method_node;
gpe_event_info->flags &= ~ACPI_GPE_DISPATCH_MASK; /* Clear bits */
if (handler->method_node) {
gpe_event_info->flags |= ACPI_GPE_DISPATCH_METHOD;
}
acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
/* Now we can free the handler object */
ACPI_FREE(handler);
unlock_and_exit:
(void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
return_ACPI_STATUS(status);
}
ACPI_EXPORT_SYMBOL(acpi_remove_gpe_handler)
/*******************************************************************************
*
* FUNCTION: acpi_acquire_global_lock
*
* PARAMETERS: Timeout - How long the caller is willing to wait
* Handle - Where the handle to the lock is returned
* (if acquired)
*
* RETURN: Status
*
* DESCRIPTION: Acquire the ACPI Global Lock
*
* Note: Allows callers with the same thread ID to acquire the global lock
* multiple times. In other words, externally, the behavior of the global lock
* is identical to an AML mutex. On the first acquire, a new handle is
* returned. On any subsequent calls to acquire by the same thread, the same
* handle is returned.
*
******************************************************************************/
acpi_status acpi_acquire_global_lock(u16 timeout, u32 * handle)
{
acpi_status status;
if (!handle) {
return (AE_BAD_PARAMETER);
}
/* Must lock interpreter to prevent race conditions */
acpi_ex_enter_interpreter();
status = acpi_ex_acquire_mutex_object(timeout,
acpi_gbl_global_lock_mutex,
acpi_os_get_thread_id());
if (ACPI_SUCCESS(status)) {
/* Return the global lock handle (updated in acpi_ev_acquire_global_lock) */
*handle = acpi_gbl_global_lock_handle;
}
acpi_ex_exit_interpreter();
return (status);
}
ACPI_EXPORT_SYMBOL(acpi_acquire_global_lock)
/*******************************************************************************
*
* FUNCTION: acpi_release_global_lock
*
* PARAMETERS: Handle - Returned from acpi_acquire_global_lock
*
* RETURN: Status
*
* DESCRIPTION: Release the ACPI Global Lock. The handle must be valid.
*
******************************************************************************/
acpi_status acpi_release_global_lock(u32 handle)
{
acpi_status status;
if (!handle || (handle != acpi_gbl_global_lock_handle)) {
return (AE_NOT_ACQUIRED);
}
status = acpi_ex_release_mutex_object(acpi_gbl_global_lock_mutex);
return (status);
}
ACPI_EXPORT_SYMBOL(acpi_release_global_lock)