blob: 980efc9bd5ee74db563b95a5ad9be80cd22c32f4 [file] [log] [blame]
// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/******************************************************************************
*
* Module Name: evregion - Operation Region support
*
* Copyright (C) 2000 - 2020, Intel Corp.
*
*****************************************************************************/
#include <acpi/acpi.h>
#include "accommon.h"
#include "acevents.h"
#include "acnamesp.h"
#include "acinterp.h"
#define _COMPONENT ACPI_EVENTS
ACPI_MODULE_NAME("evregion")
extern u8 acpi_gbl_default_address_spaces[];
/* Local prototypes */
static void
acpi_ev_orphan_ec_reg_method(struct acpi_namespace_node *ec_device_node);
static acpi_status
acpi_ev_reg_run(acpi_handle obj_handle,
u32 level, void *context, void **return_value);
/*******************************************************************************
*
* FUNCTION: acpi_ev_initialize_op_regions
*
* PARAMETERS: None
*
* RETURN: Status
*
* DESCRIPTION: Execute _REG methods for all Operation Regions that have
* an installed default region handler.
*
******************************************************************************/
acpi_status acpi_ev_initialize_op_regions(void)
{
acpi_status status;
u32 i;
ACPI_FUNCTION_TRACE(ev_initialize_op_regions);
status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
/* Run the _REG methods for op_regions in each default address space */
for (i = 0; i < ACPI_NUM_DEFAULT_SPACES; i++) {
/*
* Make sure the installed handler is the DEFAULT handler. If not the
* default, the _REG methods will have already been run (when the
* handler was installed)
*/
if (acpi_ev_has_default_handler(acpi_gbl_root_node,
acpi_gbl_default_address_spaces
[i])) {
acpi_ev_execute_reg_methods(acpi_gbl_root_node,
acpi_gbl_default_address_spaces
[i], ACPI_REG_CONNECT);
}
}
(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
return_ACPI_STATUS(status);
}
/*******************************************************************************
*
* FUNCTION: acpi_ev_address_space_dispatch
*
* PARAMETERS: region_obj - Internal region object
* field_obj - Corresponding field. Can be NULL.
* function - Read or Write operation
* region_offset - Where in the region to read or write
* bit_width - Field width in bits (8, 16, 32, or 64)
* value - Pointer to in or out value, must be
* a full 64-bit integer
*
* RETURN: Status
*
* DESCRIPTION: Dispatch an address space or operation region access to
* a previously installed handler.
*
* NOTE: During early initialization, we always install the default region
* handlers for Memory, I/O and PCI_Config. This ensures that these operation
* region address spaces are always available as per the ACPI specification.
* This is especially needed in order to support the execution of
* module-level AML code during loading of the ACPI tables.
*
******************************************************************************/
acpi_status
acpi_ev_address_space_dispatch(union acpi_operand_object *region_obj,
union acpi_operand_object *field_obj,
u32 function,
u32 region_offset, u32 bit_width, u64 *value)
{
acpi_status status;
acpi_adr_space_handler handler;
acpi_adr_space_setup region_setup;
union acpi_operand_object *handler_desc;
union acpi_operand_object *region_obj2;
void *region_context = NULL;
struct acpi_connection_info *context;
acpi_mutex context_mutex;
u8 context_locked;
acpi_physical_address address;
ACPI_FUNCTION_TRACE(ev_address_space_dispatch);
region_obj2 = acpi_ns_get_secondary_object(region_obj);
if (!region_obj2) {
return_ACPI_STATUS(AE_NOT_EXIST);
}
/* Ensure that there is a handler associated with this region */
handler_desc = region_obj->region.handler;
if (!handler_desc) {
ACPI_ERROR((AE_INFO,
"No handler for Region [%4.4s] (%p) [%s]",
acpi_ut_get_node_name(region_obj->region.node),
region_obj,
acpi_ut_get_region_name(region_obj->region.
space_id)));
return_ACPI_STATUS(AE_NOT_EXIST);
}
context = handler_desc->address_space.context;
context_mutex = handler_desc->address_space.context_mutex;
context_locked = FALSE;
/*
* It may be the case that the region has never been initialized.
* Some types of regions require special init code
*/
if (!(region_obj->region.flags & AOPOBJ_SETUP_COMPLETE)) {
/* This region has not been initialized yet, do it */
region_setup = handler_desc->address_space.setup;
if (!region_setup) {
/* No initialization routine, exit with error */
ACPI_ERROR((AE_INFO,
"No init routine for region(%p) [%s]",
region_obj,
acpi_ut_get_region_name(region_obj->region.
space_id)));
return_ACPI_STATUS(AE_NOT_EXIST);
}
/*
* We must exit the interpreter because the region setup will
* potentially execute control methods (for example, the _REG method
* for this region)
*/
acpi_ex_exit_interpreter();
status = region_setup(region_obj, ACPI_REGION_ACTIVATE,
context, &region_context);
/* Re-enter the interpreter */
acpi_ex_enter_interpreter();
/* Check for failure of the Region Setup */
if (ACPI_FAILURE(status)) {
ACPI_EXCEPTION((AE_INFO, status,
"During region initialization: [%s]",
acpi_ut_get_region_name(region_obj->
region.
space_id)));
return_ACPI_STATUS(status);
}
/* Region initialization may have been completed by region_setup */
if (!(region_obj->region.flags & AOPOBJ_SETUP_COMPLETE)) {
region_obj->region.flags |= AOPOBJ_SETUP_COMPLETE;
/*
* Save the returned context for use in all accesses to
* the handler for this particular region
*/
if (!(region_obj2->extra.region_context)) {
region_obj2->extra.region_context =
region_context;
}
}
}
/* We have everything we need, we can invoke the address space handler */
handler = handler_desc->address_space.handler;
address = (region_obj->region.address + region_offset);
ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
"Handler %p (@%p) Address %8.8X%8.8X [%s]\n",
&region_obj->region.handler->address_space, handler,
ACPI_FORMAT_UINT64(address),
acpi_ut_get_region_name(region_obj->region.
space_id)));
if (!(handler_desc->address_space.handler_flags &
ACPI_ADDR_HANDLER_DEFAULT_INSTALLED)) {
/*
* For handlers other than the default (supplied) handlers, we must
* exit the interpreter because the handler *might* block -- we don't
* know what it will do, so we can't hold the lock on the interpreter.
*/
acpi_ex_exit_interpreter();
}
/*
* Special handling for generic_serial_bus and general_purpose_io:
* There are three extra parameters that must be passed to the
* handler via the context:
* 1) Connection buffer, a resource template from Connection() op
* 2) Length of the above buffer
* 3) Actual access length from the access_as() op
*
* Since we pass these extra parameters via the context, which is
* shared between threads, we must lock the context to avoid these
* parameters being changed from another thread before the handler
* has completed running.
*
* In addition, for general_purpose_io, the Address and bit_width fields
* are defined as follows:
* 1) Address is the pin number index of the field (bit offset from
* the previous Connection)
* 2) bit_width is the actual bit length of the field (number of pins)
*/
if ((region_obj->region.space_id == ACPI_ADR_SPACE_GSBUS) &&
context && field_obj) {
status =
acpi_os_acquire_mutex(context_mutex, ACPI_WAIT_FOREVER);
if (ACPI_FAILURE(status)) {
goto re_enter_interpreter;
}
context_locked = TRUE;
/* Get the Connection (resource_template) buffer */
context->connection = field_obj->field.resource_buffer;
context->length = field_obj->field.resource_length;
context->access_length = field_obj->field.access_length;
}
if ((region_obj->region.space_id == ACPI_ADR_SPACE_GPIO) &&
context && field_obj) {
status =
acpi_os_acquire_mutex(context_mutex, ACPI_WAIT_FOREVER);
if (ACPI_FAILURE(status)) {
goto re_enter_interpreter;
}
context_locked = TRUE;
/* Get the Connection (resource_template) buffer */
context->connection = field_obj->field.resource_buffer;
context->length = field_obj->field.resource_length;
context->access_length = field_obj->field.access_length;
address = field_obj->field.pin_number_index;
bit_width = field_obj->field.bit_length;
}
/* Call the handler */
status = handler(function, address, bit_width, value, context,
region_obj2->extra.region_context);
if (context_locked) {
acpi_os_release_mutex(context_mutex);
}
if (ACPI_FAILURE(status)) {
ACPI_EXCEPTION((AE_INFO, status, "Returned by Handler for [%s]",
acpi_ut_get_region_name(region_obj->region.
space_id)));
/*
* Special case for an EC timeout. These are seen so frequently
* that an additional error message is helpful
*/
if ((region_obj->region.space_id == ACPI_ADR_SPACE_EC) &&
(status == AE_TIME)) {
ACPI_ERROR((AE_INFO,
"Timeout from EC hardware or EC device driver"));
}
}
re_enter_interpreter:
if (!(handler_desc->address_space.handler_flags &
ACPI_ADDR_HANDLER_DEFAULT_INSTALLED)) {
/*
* We just returned from a non-default handler, we must re-enter the
* interpreter
*/
acpi_ex_enter_interpreter();
}
return_ACPI_STATUS(status);
}
/*******************************************************************************
*
* FUNCTION: acpi_ev_detach_region
*
* PARAMETERS: region_obj - Region Object
* acpi_ns_is_locked - Namespace Region Already Locked?
*
* RETURN: None
*
* DESCRIPTION: Break the association between the handler and the region
* this is a two way association.
*
******************************************************************************/
void
acpi_ev_detach_region(union acpi_operand_object *region_obj,
u8 acpi_ns_is_locked)
{
union acpi_operand_object *handler_obj;
union acpi_operand_object *obj_desc;
union acpi_operand_object *start_desc;
union acpi_operand_object **last_obj_ptr;
acpi_adr_space_setup region_setup;
void **region_context;
union acpi_operand_object *region_obj2;
acpi_status status;
ACPI_FUNCTION_TRACE(ev_detach_region);
region_obj2 = acpi_ns_get_secondary_object(region_obj);
if (!region_obj2) {
return_VOID;
}
region_context = &region_obj2->extra.region_context;
/* Get the address handler from the region object */
handler_obj = region_obj->region.handler;
if (!handler_obj) {
/* This region has no handler, all done */
return_VOID;
}
/* Find this region in the handler's list */
obj_desc = handler_obj->address_space.region_list;
start_desc = obj_desc;
last_obj_ptr = &handler_obj->address_space.region_list;
while (obj_desc) {
/* Is this the correct Region? */
if (obj_desc == region_obj) {
ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
"Removing Region %p from address handler %p\n",
region_obj, handler_obj));
/* This is it, remove it from the handler's list */
*last_obj_ptr = obj_desc->region.next;
obj_desc->region.next = NULL; /* Must clear field */
if (acpi_ns_is_locked) {
status =
acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
if (ACPI_FAILURE(status)) {
return_VOID;
}
}
/* Now stop region accesses by executing the _REG method */
status =
acpi_ev_execute_reg_method(region_obj,
ACPI_REG_DISCONNECT);
if (ACPI_FAILURE(status)) {
ACPI_EXCEPTION((AE_INFO, status,
"from region _REG, [%s]",
acpi_ut_get_region_name
(region_obj->region.space_id)));
}
if (acpi_ns_is_locked) {
status =
acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
if (ACPI_FAILURE(status)) {
return_VOID;
}
}
/*
* If the region has been activated, call the setup handler with
* the deactivate notification
*/
if (region_obj->region.flags & AOPOBJ_SETUP_COMPLETE) {
region_setup = handler_obj->address_space.setup;
status =
region_setup(region_obj,
ACPI_REGION_DEACTIVATE,
handler_obj->address_space.
context, region_context);
/*
* region_context should have been released by the deactivate
* operation. We don't need access to it anymore here.
*/
if (region_context) {
*region_context = NULL;
}
/* Init routine may fail, Just ignore errors */
if (ACPI_FAILURE(status)) {
ACPI_EXCEPTION((AE_INFO, status,
"from region handler - deactivate, [%s]",
acpi_ut_get_region_name
(region_obj->region.
space_id)));
}
region_obj->region.flags &=
~(AOPOBJ_SETUP_COMPLETE);
}
/*
* Remove handler reference in the region
*
* NOTE: this doesn't mean that the region goes away, the region
* is just inaccessible as indicated to the _REG method
*
* If the region is on the handler's list, this must be the
* region's handler
*/
region_obj->region.handler = NULL;
acpi_ut_remove_reference(handler_obj);
return_VOID;
}
/* Walk the linked list of handlers */
last_obj_ptr = &obj_desc->region.next;
obj_desc = obj_desc->region.next;
/* Prevent infinite loop if list is corrupted */
if (obj_desc == start_desc) {
ACPI_ERROR((AE_INFO,
"Circular handler list in region object %p",
region_obj));
return_VOID;
}
}
/* If we get here, the region was not in the handler's region list */
ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
"Cannot remove region %p from address handler %p\n",
region_obj, handler_obj));
return_VOID;
}
/*******************************************************************************
*
* FUNCTION: acpi_ev_attach_region
*
* PARAMETERS: handler_obj - Handler Object
* region_obj - Region Object
* acpi_ns_is_locked - Namespace Region Already Locked?
*
* RETURN: None
*
* DESCRIPTION: Create the association between the handler and the region
* this is a two way association.
*
******************************************************************************/
acpi_status
acpi_ev_attach_region(union acpi_operand_object *handler_obj,
union acpi_operand_object *region_obj,
u8 acpi_ns_is_locked)
{
ACPI_FUNCTION_TRACE(ev_attach_region);
/* Install the region's handler */
if (region_obj->region.handler) {
return_ACPI_STATUS(AE_ALREADY_EXISTS);
}
ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
"Adding Region [%4.4s] %p to address handler %p [%s]\n",
acpi_ut_get_node_name(region_obj->region.node),
region_obj, handler_obj,
acpi_ut_get_region_name(region_obj->region.
space_id)));
/* Link this region to the front of the handler's list */
region_obj->region.next = handler_obj->address_space.region_list;
handler_obj->address_space.region_list = region_obj;
region_obj->region.handler = handler_obj;
acpi_ut_add_reference(handler_obj);
return_ACPI_STATUS(AE_OK);
}
/*******************************************************************************
*
* FUNCTION: acpi_ev_execute_reg_method
*
* PARAMETERS: region_obj - Region object
* function - Passed to _REG: On (1) or Off (0)
*
* RETURN: Status
*
* DESCRIPTION: Execute _REG method for a region
*
******************************************************************************/
acpi_status
acpi_ev_execute_reg_method(union acpi_operand_object *region_obj, u32 function)
{
struct acpi_evaluate_info *info;
union acpi_operand_object *args[3];
union acpi_operand_object *region_obj2;
const acpi_name *reg_name_ptr =
ACPI_CAST_PTR(acpi_name, METHOD_NAME__REG);
struct acpi_namespace_node *method_node;
struct acpi_namespace_node *node;
acpi_status status;
ACPI_FUNCTION_TRACE(ev_execute_reg_method);
if (!acpi_gbl_namespace_initialized ||
region_obj->region.handler == NULL) {
return_ACPI_STATUS(AE_OK);
}
region_obj2 = acpi_ns_get_secondary_object(region_obj);
if (!region_obj2) {
return_ACPI_STATUS(AE_NOT_EXIST);
}
/*
* Find any "_REG" method associated with this region definition.
* The method should always be updated as this function may be
* invoked after a namespace change.
*/
node = region_obj->region.node->parent;
status =
acpi_ns_search_one_scope(*reg_name_ptr, node, ACPI_TYPE_METHOD,
&method_node);
if (ACPI_SUCCESS(status)) {
/*
* The _REG method is optional and there can be only one per
* region definition. This will be executed when the handler is
* attached or removed.
*/
region_obj2->extra.method_REG = method_node;
}
if (region_obj2->extra.method_REG == NULL) {
return_ACPI_STATUS(AE_OK);
}
/* _REG(DISCONNECT) should be paired with _REG(CONNECT) */
if ((function == ACPI_REG_CONNECT &&
region_obj->common.flags & AOPOBJ_REG_CONNECTED) ||
(function == ACPI_REG_DISCONNECT &&
!(region_obj->common.flags & AOPOBJ_REG_CONNECTED))) {
return_ACPI_STATUS(AE_OK);
}
/* Allocate and initialize the evaluation information block */
info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
if (!info) {
return_ACPI_STATUS(AE_NO_MEMORY);
}
info->prefix_node = region_obj2->extra.method_REG;
info->relative_pathname = NULL;
info->parameters = args;
info->flags = ACPI_IGNORE_RETURN_VALUE;
/*
* The _REG method has two arguments:
*
* arg0 - Integer:
* Operation region space ID Same value as region_obj->Region.space_id
*
* arg1 - Integer:
* connection status 1 for connecting the handler, 0 for disconnecting
* the handler (Passed as a parameter)
*/
args[0] =
acpi_ut_create_integer_object((u64)region_obj->region.space_id);
if (!args[0]) {
status = AE_NO_MEMORY;
goto cleanup1;
}
args[1] = acpi_ut_create_integer_object((u64)function);
if (!args[1]) {
status = AE_NO_MEMORY;
goto cleanup2;
}
args[2] = NULL; /* Terminate list */
/* Execute the method, no return value */
ACPI_DEBUG_EXEC(acpi_ut_display_init_pathname
(ACPI_TYPE_METHOD, info->prefix_node, NULL));
status = acpi_ns_evaluate(info);
acpi_ut_remove_reference(args[1]);
if (ACPI_FAILURE(status)) {
goto cleanup2;
}
if (function == ACPI_REG_CONNECT) {
region_obj->common.flags |= AOPOBJ_REG_CONNECTED;
} else {
region_obj->common.flags &= ~AOPOBJ_REG_CONNECTED;
}
cleanup2:
acpi_ut_remove_reference(args[0]);
cleanup1:
ACPI_FREE(info);
return_ACPI_STATUS(status);
}
/*******************************************************************************
*
* FUNCTION: acpi_ev_execute_reg_methods
*
* PARAMETERS: node - Namespace node for the device
* space_id - The address space ID
* function - Passed to _REG: On (1) or Off (0)
*
* RETURN: None
*
* DESCRIPTION: Run all _REG methods for the input Space ID;
* Note: assumes namespace is locked, or system init time.
*
******************************************************************************/
void
acpi_ev_execute_reg_methods(struct acpi_namespace_node *node,
acpi_adr_space_type space_id, u32 function)
{
struct acpi_reg_walk_info info;
ACPI_FUNCTION_TRACE(ev_execute_reg_methods);
/*
* These address spaces do not need a call to _REG, since the ACPI
* specification defines them as: "must always be accessible". Since
* they never change state (never become unavailable), no need to ever
* call _REG on them. Also, a data_table is not a "real" address space,
* so do not call _REG. September 2018.
*/
if ((space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) ||
(space_id == ACPI_ADR_SPACE_SYSTEM_IO) ||
(space_id == ACPI_ADR_SPACE_DATA_TABLE)) {
return_VOID;
}
info.space_id = space_id;
info.function = function;
info.reg_run_count = 0;
ACPI_DEBUG_PRINT_RAW((ACPI_DB_NAMES,
" Running _REG methods for SpaceId %s\n",
acpi_ut_get_region_name(info.space_id)));
/*
* Run all _REG methods for all Operation Regions for this space ID. This
* is a separate walk in order to handle any interdependencies between
* regions and _REG methods. (i.e. handlers must be installed for all
* regions of this Space ID before we can run any _REG methods)
*/
(void)acpi_ns_walk_namespace(ACPI_TYPE_ANY, node, ACPI_UINT32_MAX,
ACPI_NS_WALK_UNLOCK, acpi_ev_reg_run, NULL,
&info, NULL);
/* Special case for EC: handle "orphan" _REG methods with no region */
if (space_id == ACPI_ADR_SPACE_EC) {
acpi_ev_orphan_ec_reg_method(node);
}
ACPI_DEBUG_PRINT_RAW((ACPI_DB_NAMES,
" Executed %u _REG methods for SpaceId %s\n",
info.reg_run_count,
acpi_ut_get_region_name(info.space_id)));
return_VOID;
}
/*******************************************************************************
*
* FUNCTION: acpi_ev_reg_run
*
* PARAMETERS: walk_namespace callback
*
* DESCRIPTION: Run _REG method for region objects of the requested spaceID
*
******************************************************************************/
static acpi_status
acpi_ev_reg_run(acpi_handle obj_handle,
u32 level, void *context, void **return_value)
{
union acpi_operand_object *obj_desc;
struct acpi_namespace_node *node;
acpi_status status;
struct acpi_reg_walk_info *info;
info = ACPI_CAST_PTR(struct acpi_reg_walk_info, context);
/* Convert and validate the device handle */
node = acpi_ns_validate_handle(obj_handle);
if (!node) {
return (AE_BAD_PARAMETER);
}
/*
* We only care about regions and objects that are allowed to have
* address space handlers
*/
if ((node->type != ACPI_TYPE_REGION) && (node != acpi_gbl_root_node)) {
return (AE_OK);
}
/* Check for an existing internal object */
obj_desc = acpi_ns_get_attached_object(node);
if (!obj_desc) {
/* No object, just exit */
return (AE_OK);
}
/* Object is a Region */
if (obj_desc->region.space_id != info->space_id) {
/* This region is for a different address space, just ignore it */
return (AE_OK);
}
info->reg_run_count++;
status = acpi_ev_execute_reg_method(obj_desc, info->function);
return (status);
}
/*******************************************************************************
*
* FUNCTION: acpi_ev_orphan_ec_reg_method
*
* PARAMETERS: ec_device_node - Namespace node for an EC device
*
* RETURN: None
*
* DESCRIPTION: Execute an "orphan" _REG method that appears under the EC
* device. This is a _REG method that has no corresponding region
* within the EC device scope. The orphan _REG method appears to
* have been enabled by the description of the ECDT in the ACPI
* specification: "The availability of the region space can be
* detected by providing a _REG method object underneath the
* Embedded Controller device."
*
* To quickly access the EC device, we use the ec_device_node used
* during EC handler installation. Otherwise, we would need to
* perform a time consuming namespace walk, executing _HID
* methods to find the EC device.
*
* MUTEX: Assumes the namespace is locked
*
******************************************************************************/
static void
acpi_ev_orphan_ec_reg_method(struct acpi_namespace_node *ec_device_node)
{
acpi_handle reg_method;
struct acpi_namespace_node *next_node;
acpi_status status;
struct acpi_object_list args;
union acpi_object objects[2];
ACPI_FUNCTION_TRACE(ev_orphan_ec_reg_method);
if (!ec_device_node) {
return_VOID;
}
/* Namespace is currently locked, must release */
(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
/* Get a handle to a _REG method immediately under the EC device */
status = acpi_get_handle(ec_device_node, METHOD_NAME__REG, &reg_method);
if (ACPI_FAILURE(status)) {
goto exit; /* There is no _REG method present */
}
/*
* Execute the _REG method only if there is no Operation Region in
* this scope with the Embedded Controller space ID. Otherwise, it
* will already have been executed. Note, this allows for Regions
* with other space IDs to be present; but the code below will then
* execute the _REG method with the embedded_control space_ID argument.
*/
next_node = acpi_ns_get_next_node(ec_device_node, NULL);
while (next_node) {
if ((next_node->type == ACPI_TYPE_REGION) &&
(next_node->object) &&
(next_node->object->region.space_id == ACPI_ADR_SPACE_EC)) {
goto exit; /* Do not execute the _REG */
}
next_node = acpi_ns_get_next_node(ec_device_node, next_node);
}
/* Evaluate the _REG(embedded_control,Connect) method */
args.count = 2;
args.pointer = objects;
objects[0].type = ACPI_TYPE_INTEGER;
objects[0].integer.value = ACPI_ADR_SPACE_EC;
objects[1].type = ACPI_TYPE_INTEGER;
objects[1].integer.value = ACPI_REG_CONNECT;
(void)acpi_evaluate_object(reg_method, NULL, &args, NULL);
exit:
/* We ignore all errors from above, don't care */
(void)acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
return_VOID;
}