nsaccess.c

h内核

/*******************************************************************************
 *
 * 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) || defined (_ACPI_DUMP_App)

				/*
				 * i_aSL Compiler cheats by putting parameter count
				 * in the owner_iD
				 */
				new_node->owner_id = obj_desc->method.param_count;
#else
				/* Mark this as a very SPECIAL method */

				obj_desc->method.method_flags = AML_METHOD_INTERNAL_ONLY;
				obj_desc->method.implementation = acpi_ut_osi_implementation;
#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:  prefix_node     - Search scope if name is not fully qualified
 *              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++;