nsaccess.c

linux-2.6.15.6

/*******************************************************************************
 *
 * Module Name: nsaccess - Top-level functions for accessing ACPI namespace
 *
 ******************************************************************************/

/*
 * Copyright (C) 2000 - 2005, 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/amlcode.h>
#include <acpi/acnamesp.h>
#include <acpi/acdispat.h>

#define _COMPONENT          ACPI_NAMESPACE
ACPI_MODULE_NAME("nsaccess")

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_root_initialize
 *
 * PARAMETERS:  None
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Allocate and initialize the default root named objects
 *
 * MUTEX:       Locks namespace for entire execution
 *
 ******************************************************************************/
acpi_status acpi_ns_root_initialize(void)
{
	acpi_status status;
	const struct acpi_predefined_names *init_val = NULL;
	struct acpi_namespace_node *new_node;
	union acpi_operand_object *obj_desc;
	acpi_string val = NULL;

	ACPI_FUNCTION_TRACE("ns_root_initialize");

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

	/*
	 * The global root ptr is initially NULL, so a non-NULL value indicates
	 * that acpi_ns_root_initialize() has already been called; just return.
	 */
	if (acpi_gbl_root_node) {
		status = AE_OK;
		goto unlock_and_exit;
	}

	/*
	 * Tell the rest of the subsystem that the root is initialized
	 * (This is OK because the namespace is locked)
	 */
	acpi_gbl_root_node = &acpi_gbl_root_node_struct;

	/* Enter the pre-defined names in the name table */

	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
			  "Entering predefined entries into namespace\n"));

	for (init_val = acpi_gbl_pre_defined_names; init_val->name; init_val++) {
		/* _OSI is optional for now, will be permanent later */

		if (!ACPI_STRCMP(init_val->name, "_OSI")
		    && !acpi_gbl_create_osi_method) {
			continue;
		}

		status = acpi_ns_lookup(NULL, init_val->name, init_val->type,
					ACPI_IMODE_LOAD_PASS2,
					ACPI_NS_NO_UPSEARCH, NULL, &new_node);

		if (ACPI_FAILURE(status) || (!new_node)) {	/* Must be on same line for code converter */
			ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
					  "Could not create predefined name %s, %s\n",
					  init_val->name,
					  acpi_format_exception(status)));
		}

		/*
		 * Name entered successfully.
		 * If entry in pre_defined_names[] specifies an
		 * initial value, create the initial value.
		 */
		if (init_val->val) {
			status = acpi_os_predefined_override(init_val, &val);
			if (ACPI_FAILURE(status)) {
				ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
						  "Could not override predefined %s\n",
						  init_val->name));
			}

			if (!val) {
				val = init_val->val;
			}

			/*
			 * Entry requests an initial value, allocate a
			 * descriptor for it.
			 */
			obj_desc =
			    acpi_ut_create_internal_object(init_val->type);
			if (!obj_desc) {
				status = AE_NO_MEMORY;
				goto unlock_and_exit;
			}

			/*
			 * Convert value string from table entry to
			 * internal representation. Only types actually
			 * used for initial values are implemented here.
			 */
			switch (init_val->type) {
			case ACPI_TYPE_METHOD:
				obj_desc->method.param_count =
				    (u8) ACPI_TO_INTEGER(val);
				obj_desc->common.flags |= AOPOBJ_DATA_VALID;

#if defined (ACPI_ASL_COMPILER)

				/* save the parameter count for the i_aSL compiler */

				new_node->value = obj_desc->method.param_count;
#else
				/* Mark this as a very SPECIAL method */

				obj_desc->method.method_flags =
				    AML_METHOD_INTERNAL_ONLY;

#ifndef ACPI_DUMP_APP
				obj_desc->method.implementation =
				    acpi_ut_osi_implementation;
#endif
#endif
				break;

			case ACPI_TYPE_INTEGER:

				obj_desc->integer.value = ACPI_TO_INTEGER(val);
				break;

			case ACPI_TYPE_STRING:

				/*
				 * Build an object around the static string
				 */
				obj_desc->string.length =
				    (u32) ACPI_STRLEN(val);
				obj_desc->string.pointer = val;
				obj_desc->common.flags |= AOPOBJ_STATIC_POINTER;
				break;

			case ACPI_TYPE_MUTEX:

				obj_desc->mutex.node = new_node;
				obj_desc->mutex.sync_level =
				    (u8) (ACPI_TO_INTEGER(val) - 1);

				if (ACPI_STRCMP(init_val->name, "_GL_") == 0) {
					/*
					 * Create a counting semaphore for the
					 * global lock
					 */
					status =
					    acpi_os_create_semaphore
					    (ACPI_NO_UNIT_LIMIT, 1,
					     &obj_desc->mutex.semaphore);
					if (ACPI_FAILURE(status)) {
						acpi_ut_remove_reference
						    (obj_desc);
						goto unlock_and_exit;
					}

					/*
					 * We just created the mutex for the
					 * global lock, save it
					 */
					acpi_gbl_global_lock_semaphore =
					    obj_desc->mutex.semaphore;
				} else {
					/* Create a mutex */

					status = acpi_os_create_semaphore(1, 1,
									  &obj_desc->
									  mutex.
									  semaphore);
					if (ACPI_FAILURE(status)) {
						acpi_ut_remove_reference
						    (obj_desc);
						goto unlock_and_exit;
					}
				}
				break;

			default:

				ACPI_REPORT_ERROR(("Unsupported initial type value %X\n", init_val->type));
				acpi_ut_remove_reference(obj_desc);
				obj_desc = NULL;
				continue;
			}

			/* Store pointer to value descriptor in the Node */

			status = acpi_ns_attach_object(new_node, obj_desc,
						       ACPI_GET_OBJECT_TYPE
						       (obj_desc));

			/* Remove local reference to the object */

			acpi_ut_remove_reference(obj_desc);
		}
	}

      unlock_and_exit:
	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);

	/* Save a handle to "_GPE", it is always present */

	if (ACPI_SUCCESS(status)) {
		status =
		    acpi_ns_get_node_by_path("\\_GPE", NULL,
					     ACPI_NS_NO_UPSEARCH,
					     &acpi_gbl_fadt_gpe_device);
	}

	return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_lookup
 *
 * PARAMETERS:  scope_info      - Current scope info block
 *              Pathname        - Search pathname, in internal format
 *                                (as represented in the AML stream)
 *              Type            - Type associated with name
 *              interpreter_mode - IMODE_LOAD_PASS2 => add name if not found
 *              Flags           - Flags describing the search restrictions
 *              walk_state      - Current state of the walk
 *              return_node     - Where the Node is placed (if found
 *                                or created successfully)
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Find or enter the passed name in the name space.
 *              Log an error if name not found in Exec mode.
 *
 * MUTEX:       Assumes namespace is locked.
 *
 ******************************************************************************/

acpi_status
acpi_ns_lookup(union acpi_generic_state *scope_info,
	       char *pathname,
	       acpi_object_type type,
	       acpi_interpreter_mode interpreter_mode,
	       u32 flags,
	       struct acpi_walk_state *walk_state,
	       struct acpi_namespace_node **return_node)
{
	acpi_status status;
	char *path = pathname;
	struct acpi_namespace_node *prefix_node;
	struct acpi_namespace_node *current_node = NULL;
	struct acpi_namespace_node *this_node = NULL;
	u32 num_segments;
	u32 num_carats;
	acpi_name simple_name;
	acpi_object_type type_to_check_for;
	acpi_object_type this_search_type;
	u32 search_parent_flag = ACPI_NS_SEARCH_PARENT;
	u32 local_flags = flags & ~(ACPI_NS_ERROR_IF_FOUND |
				    ACPI_NS_SEARCH_PARENT);

	ACPI_FUNCTION_TRACE("ns_lookup");

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

	acpi_gbl_ns_lookup_count++;