evregion.c

linux-2.4.29操作系统的源码

 *
 ******************************************************************************/

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       **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;
	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, 0);
			if (ACPI_FAILURE (status)) {
				ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "%s from region _REG, [%s]\n",
					acpi_format_exception (status),
					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;
				}
			}

			/* Call the setup handler with the deactivate notification */

			region_setup = handler_obj->address_space.setup;
			status = region_setup (region_obj, ACPI_REGION_DEACTIVATE,
					  handler_obj->address_space.context, region_context);

			/* Init routine may fail, Just ignore errors */

			if (ACPI_FAILURE (status)) {
				ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "%s from region init, [%s]\n",
					acpi_format_exception (status),
					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 better 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;
	}

	/* 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");


	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;

	/* Install the region's handler */

	if (region_obj->region.handler) {
		return_ACPI_STATUS (AE_ALREADY_EXISTS);
	}

	region_obj->region.handler = handler_obj;
	acpi_ut_add_reference (handler_obj);

	return_ACPI_STATUS (AE_OK);
}


/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_install_handler
 *
 * PARAMETERS:  walk_namespace callback
 *
 * DESCRIPTION: This routine installs an address handler into objects that are
 *              of type Region or Device.
 *
 *              If the Object is a Device, and the device has a handler of
 *              the same type then the search is terminated in that branch.
 *
 *              This is because the existing handler is closer in proximity
 *              to any more regions than the one we are trying to install.
 *
 ******************************************************************************/

acpi_status
acpi_ev_install_handler (
	acpi_handle                     obj_handle,
	u32                             level,
	void                            *context,
	void                            **return_value)
{
	union acpi_operand_object       *handler_obj;
	union acpi_operand_object       *next_handler_obj;
	union acpi_operand_object       *obj_desc;
	struct acpi_namespace_node      *node;
	acpi_status                     status;


	ACPI_FUNCTION_NAME ("ev_install_handler");


	handler_obj = (union acpi_operand_object   *) context;

	/* Parameter validation */

	if (!handler_obj) {
		return (AE_OK);
	}

	/* Convert and validate the device handle */

	node = acpi_ns_map_handle_to_node (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_DEVICE) &&
		(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);
	}

	/* Devices are handled different than regions */

	if (ACPI_GET_OBJECT_TYPE (obj_desc) == ACPI_TYPE_DEVICE) {
		/* Check if this Device already has a handler for this address space */

		next_handler_obj = obj_desc->device.handler;
		while (next_handler_obj) {
			/* Found a handler, is it for the same address space? */

			if (next_handler_obj->address_space.space_id == handler_obj->address_space.space_id) {
				ACPI_DEBUG_PRINT ((ACPI_DB_OPREGION,
					"Found handler for region [%s] in device %p(%p) handler %p\n",
					acpi_ut_get_region_name (handler_obj->address_space.space_id),
					obj_desc, next_handler_obj, handler_obj));

				/*
				 * Since the object we found it on was a device, then it
				 * means that someone has already installed a handler for
				 * the branch of the namespace from this device on.  Just
				 * bail out telling the walk routine to not traverse this
				 * branch.  This preserves the scoping rule for handlers.
				 */
				return (AE_CTRL_DEPTH);
			}

			/* Walk the linked list of handlers attached to this device */

			next_handler_obj = next_handler_obj->address_space.next;
		}

		/*
		 * As long as the device didn't have a handler for this
		 * space we don't care about it.  We just ignore it and
		 * proceed.
		 */
		return (AE_OK);
	}

	/* Object is a Region */

	if (obj_desc->region.space_id != handler_obj->address_space.space_id) {
		/*
		 * This region is for a different address space
		 * -- just ignore it
		 */
		return (AE_OK);
	}

	/*
	 * Now we have a region and it is for the handler's address
	 * space type.
	 *
	 * First disconnect region for any previous handler (if any)
	 */
	acpi_ev_detach_region (obj_desc, FALSE);

	/* Connect the region to the new handler */

	status = acpi_ev_attach_region (handler_obj, obj_desc, FALSE);
	return (status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_reg_run
 *
 * PARAMETERS:  walk_namespace callback
 *
 * DESCRIPTION: Run _REg method for region objects of the requested space_iD
 *
 ******************************************************************************/

acpi_status
acpi_ev_reg_run (
	acpi_handle                     obj_handle,
	u32                             level,
	void                            *context,
	void                            **return_value)
{
	union acpi_operand_object       *handler_obj;
	union acpi_operand_object       *obj_desc;
	struct acpi_namespace_node      *node;
	acpi_status                     status;


	handler_obj = (union acpi_operand_object   *) context;

	/* Parameter validation */

	if (!handler_obj) {
		return (AE_OK);
	}

	/* Convert and validate the device handle */

	node = acpi_ns_map_handle_to_node (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 != handler_obj->address_space.space_id) {
		/*
		 * This region is for a different address space
		 * -- just ignore it
		 */
		return (AE_OK);
	}

	status = acpi_ev_execute_reg_method (obj_desc, 1);
	return (status);
}