nsaccess.c

内核linux2.4.20,可跟rtlinux3.2打补丁 组成实时linux系统,编译内核

/*******************************************************************************
 *
 * Module Name: nsaccess - Top-level functions for accessing ACPI namespace
 *              $Revision: 135 $
 *
 ******************************************************************************/

/*
 *  Copyright (C) 2000, 2001 R. Byron Moore
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */


#include "acpi.h"
#include "amlcode.h"
#include "acinterp.h"
#include "acnamesp.h"
#include "acdispat.h"


#define _COMPONENT          ACPI_NAMESPACE
	 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 = AE_OK;
	const predefined_names  *init_val = NULL;
	acpi_namespace_node     *new_node;
	acpi_operand_object     *obj_desc;


	FUNCTION_TRACE ("Ns_root_initialize");


	acpi_ut_acquire_mutex (ACPI_MTX_NAMESPACE);

	/*
	 * 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++) {
		status = acpi_ns_lookup (NULL, init_val->name, init_val->type,
				 IMODE_LOAD_PASS2, 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) {
			/*
			 * 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_INTEGER:

				obj_desc->integer.value =
						(acpi_integer) STRTOUL (init_val->val, NULL, 10);
				break;


			case ACPI_TYPE_STRING:

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


			case ACPI_TYPE_MUTEX:

				obj_desc->mutex.sync_level =
						 (u16) STRTOUL (init_val->val, NULL, 10);

				if (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)) {
						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)) {
						goto unlock_and_exit;
					}
				}
				break;


			default:
				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 */

			acpi_ns_attach_object (new_node, obj_desc, obj_desc->common.type);

			/* Remove local reference to the object */

			acpi_ut_remove_reference (obj_desc);
		}
	}


unlock_and_exit:
	acpi_ut_release_mutex (ACPI_MTX_NAMESPACE);
	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 (
	acpi_generic_state      *scope_info,
	NATIVE_CHAR             *pathname,
	acpi_object_type8       type,
	operating_mode          interpreter_mode,
	u32                     flags,
	acpi_walk_state         *walk_state,
	acpi_namespace_node     **return_node)
{
	acpi_status             status;
	acpi_namespace_node     *prefix_node;
	acpi_namespace_node     *current_node = NULL;
	acpi_namespace_node     *scope_to_push = NULL;
	acpi_namespace_node     *this_node = NULL;
	u32                     num_segments;
	acpi_name               simple_name;
	u8                      null_name_path = FALSE;
	acpi_object_type8       type_to_check_for;
	acpi_object_type8       this_search_type;
	u32                     local_flags = flags & ~NS_ERROR_IF_FOUND;

	DEBUG_EXEC              (u32 i;)


	FUNCTION_TRACE ("Ns_lookup");


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


	acpi_gbl_ns_lookup_count++;

	*return_node = ENTRY_NOT_FOUND;


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

	/*
	 * Get the prefix scope.
	 * A null scope means use the root scope
	 */
	if ((!scope_info) ||
		(!scope_info->scope.node)) {
		ACPI_DEBUG_PRINT ((ACPI_DB_NAMES, "Null scope prefix, using root node (%p)\n",
			acpi_gbl_root_node));

		prefix_node = acpi_gbl_root_node;
	}
	else {
		prefix_node = scope_info->scope.node;
	}


	/*
	 * This check is explicitly split to relax the Type_to_check_for
	 * conditions for Bank_field_defn. Originally, both Bank_field_defn and
	 * Def_field_defn caused Type_to_check_for to be set to ACPI_TYPE_REGION,
	 * but the Bank_field_defn may also check for a Field definition as well
	 * as an Operation_region.
	 */
	if (INTERNAL_TYPE_FIELD_DEFN == type) {