drivers/acpi/namespace/nsload.c

/******************************************************************************
 *
 * Module Name: nsload - namespace loading/expanding/contracting procedures
 *
 *****************************************************************************/

/*
 * 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/acnamesp.h>
#include <acpi/acdispat.h>

#define _COMPONENT          ACPI_NAMESPACE
ACPI_MODULE_NAME("nsload")

/* Local prototypes */
static acpi_status acpi_ns_load_table_by_type(acpi_table_type table_type);

#ifdef ACPI_FUTURE_IMPLEMENTATION
acpi_status acpi_ns_unload_namespace(acpi_handle handle);

static acpi_status acpi_ns_delete_subtree(acpi_handle start_handle);
#endif

#ifndef ACPI_NO_METHOD_EXECUTION
/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_load_table
 *
 * PARAMETERS:  table_desc      - Descriptor for table to be loaded
 *              Node            - Owning NS node
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Load one ACPI table into the namespace
 *
 ******************************************************************************/

acpi_status
acpi_ns_load_table(struct acpi_table_desc *table_desc,
		   struct acpi_namespace_node *node)
{
	acpi_status status;

	ACPI_FUNCTION_TRACE("ns_load_table");

	/* Check if table contains valid AML (must be DSDT, PSDT, SSDT, etc.) */

	if (!
	    (acpi_gbl_table_data[table_desc->type].
	     flags & ACPI_TABLE_EXECUTABLE)) {
		/* Just ignore this table */

		return_ACPI_STATUS(AE_OK);
	}

	/* Check validity of the AML start and length */

	if (!table_desc->aml_start) {
		ACPI_ERROR((AE_INFO, "Null AML pointer"));
		return_ACPI_STATUS(AE_BAD_PARAMETER);
	}

	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "AML block at %p\n",
			  table_desc->aml_start));

	/* Ignore table if there is no AML contained within */

	if (!table_desc->aml_length) {
		ACPI_WARNING((AE_INFO, "Zero-length AML block in table [%4.4s]",
			      table_desc->pointer->signature));
		return_ACPI_STATUS(AE_OK);
	}

	/*
	 * Parse the table and load the namespace with all named
	 * objects found within.  Control methods are NOT parsed
	 * at this time.  In fact, the control methods cannot be
	 * parsed until the entire namespace is loaded, because
	 * if a control method makes a forward reference (call)
	 * to another control method, we can't continue parsing
	 * because we don't know how many arguments to parse next!
	 */
	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
			  "**** Loading table into namespace ****\n"));

	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
	if (ACPI_FAILURE(status)) {
		return_ACPI_STATUS(status);
	}

	status = acpi_ns_parse_table(table_desc, node->child);
	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);

	if (ACPI_FAILURE(status)) {
		return_ACPI_STATUS(status);
	}

	/*
	 * Now we can parse the control methods.  We always parse
	 * them here for a sanity check, and if configured for
	 * just-in-time parsing, we delete the control method
	 * parse trees.
	 */
	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
			  "**** Begin Table Method Parsing and Object Initialization ****\n"));

	status = acpi_ds_initialize_objects(table_desc, node);

	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
			  "**** Completed Table Method Parsing and Object Initialization ****\n"));

	return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_load_table_by_type
 *
 * PARAMETERS:  table_type          - Id of the table type to load
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Load an ACPI table or tables into the namespace.  All tables
 *              of the given type are loaded.  The mechanism allows this
 *              routine to be called repeatedly.
 *
 ******************************************************************************/

static acpi_status acpi_ns_load_table_by_type(acpi_table_type table_type)
{
	u32 i;
	acpi_status status;
	struct acpi_table_desc *table_desc;

	ACPI_FUNCTION_TRACE("ns_load_table_by_type");

	status = acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
	if (ACPI_FAILURE(status)) {
		return_ACPI_STATUS(status);
	}

	/*
	 * Table types supported are:
	 * DSDT (one), SSDT/PSDT (multiple)
	 */
	switch (table_type) {
	case ACPI_TABLE_DSDT:

		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Namespace load: DSDT\n"));

		table_desc = acpi_gbl_table_lists[ACPI_TABLE_DSDT].next;

		/* If table already loaded into namespace, just return */

		if (table_desc->loaded_into_namespace) {
			goto unlock_and_exit;
		}

		/* Now load the single DSDT */

		status = acpi_ns_load_table(table_desc, acpi_gbl_root_node);
		if (ACPI_SUCCESS(status)) {
			table_desc->loaded_into_namespace = TRUE;
		}
		break;

	case ACPI_TABLE_SSDT:
	case ACPI_TABLE_PSDT:

		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
				  "Namespace load: %d SSDT or PSDTs\n",
				  acpi_gbl_table_lists[table_type].count));

		/*
		 * Traverse list of SSDT or PSDT tables
		 */
		table_desc = acpi_gbl_table_lists[table_type].next;
		for (i = 0; i < acpi_gbl_table_lists[table_type].count; i++) {
			/*
			 * Only attempt to load table into namespace if it is not
			 * already loaded!
			 */
			if (!table_desc->loaded_into_namespace) {
				status =
				    acpi_ns_load_table(table_desc,
						       acpi_gbl_root_node);
				if (ACPI_FAILURE(status)) {
					break;
				}

				table_desc->loaded_into_namespace = TRUE;
			}

			table_desc = table_desc->next;
		}
		break;

	default:
		status = AE_SUPPORT;
		break;
	}

      unlock_and_exit:
	(void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
	return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_load_namespace
 *
 * PARAMETERS:  None
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Load the name space from what ever is pointed to by DSDT.
 *              (DSDT points to either the BIOS or a buffer.)
 *
 ******************************************************************************/

acpi_status acpi_ns_load_namespace(void)
{
	acpi_status status;

	ACPI_FUNCTION_TRACE("acpi_load_name_space");

	/* There must be at least a DSDT installed */

	if (acpi_gbl_DSDT == NULL) {
		ACPI_ERROR((AE_INFO, "DSDT is not in memory"));
		return_ACPI_STATUS(AE_NO_ACPI_TABLES);
	}

	/*
	 * Load the namespace.  The DSDT is required,
	 * but the SSDT and PSDT tables are optional.
	 */
	status = acpi_ns_load_table_by_type(ACPI_TABLE_DSDT);
	if (ACPI_FAILURE(status)) {
		return_ACPI_STATUS(status);
	}

	/* Ignore exceptions from these */

	(void)acpi_ns_load_table_by_type(ACPI_TABLE_SSDT);
	(void)acpi_ns_load_table_by_type(ACPI_TABLE_PSDT);

	ACPI_DEBUG_PRINT_RAW((ACPI_DB_INIT,
			      "ACPI Namespace successfully loaded at root %p\n",
			      acpi_gbl_root_node));

	return_ACPI_STATUS(status);
}

#ifdef ACPI_FUTURE_IMPLEMENTATION
/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_delete_subtree
 *
 * PARAMETERS:  start_handle        - Handle in namespace where search begins
 *
 * RETURNS      Status
 *
 * DESCRIPTION: Walks the namespace starting at the given handle and deletes
 *              all objects, entries, and scopes in the entire subtree.
 *
 *              Namespace/Interpreter should be locked or the subsystem should
 *              be in shutdown before this routine is called.
 *
 ******************************************************************************/

static acpi_status acpi_ns_delete_subtree(acpi_handle start_handle)
{
	acpi_status status;
	acpi_handle child_handle;
	acpi_handle parent_handle;
	acpi_handle next_child_handle;
	acpi_handle dummy;
	u32 level;

	ACPI_FUNCTION_TRACE("ns_delete_subtree");

	parent_handle = start_handle;
	child_handle = NULL;
	level = 1;

	/*
	 * Traverse the tree of objects until we bubble back up
	 * to where we started.
	 */
	while (level > 0) {
		/* Attempt to get the next object in this scope */

		status = acpi_get_next_object(ACPI_TYPE_ANY, parent_handle,
					      child_handle, &next_child_handle);

		child_handle = next_child_handle;

		/* Did we get a new object? */

		if (ACPI_SUCCESS(status)) {
			/* Check if this object has any children */

			if (ACPI_SUCCESS
			    (acpi_get_next_object
			     (ACPI_TYPE_ANY, child_handle, NULL, &dummy))) {
				/*
				 * There is at least one child of this object,
				 * visit the object
				 */
				level++;
				parent_handle = child_handle;
				child_handle = NULL;
			}
		} else {
			/*
			 * No more children in this object, go back up to
			 * the object's parent
			 */
			level--;

			/* Delete all children now */

			acpi_ns_delete_children(child_handle);

			child_handle = parent_handle;
			status = acpi_get_parent(parent_handle, &parent_handle);
			if (ACPI_FAILURE(status)) {
				return_ACPI_STATUS(status);
			}
		}
	}

	/* Now delete the starting object, and we are done */

	acpi_ns_delete_node(child_handle);

	return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
 *
 *  FUNCTION:       acpi_ns_unload_name_space
 *
 *  PARAMETERS:     Handle          - Root of namespace subtree to be deleted
 *
 *  RETURN:         Status
 *
 *  DESCRIPTION:    Shrinks the namespace, typically in response to an undocking
 *                  event.  Deletes an entire subtree starting from (and
 *                  including) the given handle.
 *
 ******************************************************************************/

acpi_status acpi_ns_unload_namespace(acpi_handle handle)
{
	acpi_status status;

	ACPI_FUNCTION_TRACE("ns_unload_name_space");

	/* Parameter validation */

	if (!acpi_gbl_root_node) {
		return_ACPI_STATUS(AE_NO_NAMESPACE);
	}

	if (!handle) {
		return_ACPI_STATUS(AE_BAD_PARAMETER);
	}

	/* This function does the real work */

	status = acpi_ns_delete_subtree(handle);

	return_ACPI_STATUS(status);
}
#endif
#endif