nsutils.c

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/******************************************************************************
 *
 * Module Name: nsutils - Utilities for accessing ACPI namespace, accessing
 *                        parents and siblings and Scope manipulation
 *              $Revision: 1.1 $
 *
 *****************************************************************************/

/*
 *  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>

#define _COMPONENT          ACPI_NAMESPACE
	 MODULE_NAME         ("nsutils")


/****************************************************************************
 *
 * FUNCTION:    Acpi_ns_valid_root_prefix
 *
 * PARAMETERS:  Prefix          - Character to be checked
 *
 * RETURN:      TRUE if a valid prefix
 *
 * DESCRIPTION: Check if a character is a valid ACPI Root prefix
 *
 ***************************************************************************/

u8
acpi_ns_valid_root_prefix (
	NATIVE_CHAR             prefix)
{

	return ((u8) (prefix == '\\'));
}


/****************************************************************************
 *
 * FUNCTION:    Acpi_ns_valid_path_separator
 *
 * PARAMETERS:  Sep              - Character to be checked
 *
 * RETURN:      TRUE if a valid path separator
 *
 * DESCRIPTION: Check if a character is a valid ACPI path separator
 *
 ***************************************************************************/

u8
acpi_ns_valid_path_separator (
	NATIVE_CHAR             sep)
{

	return ((u8) (sep == '.'));
}


/****************************************************************************
 *
 * FUNCTION:    Acpi_ns_get_type
 *
 * PARAMETERS:  Handle              - Parent Node to be examined
 *
 * RETURN:      Type field from Node whose handle is passed
 *
 ***************************************************************************/

OBJECT_TYPE_INTERNAL
acpi_ns_get_type (
	ACPI_HANDLE             handle)
{

	if (!handle) {
		REPORT_WARNING (("Ns_get_type: Null handle\n"));
		return (ACPI_TYPE_ANY);
	}

	return (((ACPI_NAMESPACE_NODE *) handle)->type);
}


/****************************************************************************
 *
 * FUNCTION:    Acpi_ns_local
 *
 * PARAMETERS:  Type            - A namespace object type
 *
 * RETURN:      LOCAL if names must be found locally in objects of the
 *              passed type, 0 if enclosing scopes should be searched
 *
 ***************************************************************************/

u32
acpi_ns_local (
	OBJECT_TYPE_INTERNAL    type)
{

	if (!acpi_cm_valid_object_type (type)) {
		/* Type code out of range  */

		REPORT_WARNING (("Ns_local: Invalid Object Type\n"));
		return (NSP_NORMAL);
	}

	return ((u32) acpi_gbl_ns_properties[type] & NSP_LOCAL);
}


/****************************************************************************
 *
 * FUNCTION:    Acpi_ns_internalize_name
 *
 * PARAMETERS:  *External_name            - External representation of name
 *              **Converted Name        - Where to return the resulting
 *                                        internal represention of the name
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Convert an external representation (e.g. "\_PR_.CPU0")
 *              to internal form (e.g. 5c 2f 02 5f 50 52 5f 43 50 55 30)
 *
 ****************************************************************************/

ACPI_STATUS
acpi_ns_internalize_name (
	NATIVE_CHAR             *external_name,
	NATIVE_CHAR             **converted_name)
{
	NATIVE_CHAR             *result = NULL;
	NATIVE_CHAR             *internal_name;
	u32                     num_segments = 0;
	u8                      fully_qualified = FALSE;
	u32                     i;
	u32                     num_carats = 0;


	if ((!external_name)     ||
		(*external_name == 0) ||
		(!converted_name)) {
		return (AE_BAD_PARAMETER);
	}


	/*
	 * For the internal name, the required length is 4 bytes
	 * per segment, plus 1 each for Root_prefix, Multi_name_prefix_op,
	 * segment count, trailing null (which is not really needed,
	 * but no there's harm in putting it there)
	 *
	 * strlen() + 1 covers the first Name_seg, which has no
	 * path separator
	 */

	if (acpi_ns_valid_root_prefix (external_name[0])) {
		fully_qualified = TRUE;
		external_name++;
	}

	else {
		/*
		 * Handle Carat prefixes
		 */

		while (*external_name == '^') {
			num_carats++;
			external_name++;
		}
	}

	/*
	 * Determine the number of ACPI name "segments" by counting
	 * the number of path separators within the string.  Start
	 * with one segment since the segment count is (# separators)
	 * + 1, and zero separators is ok.
	 */

	if (*external_name) {
		num_segments = 1;
		for (i = 0; external_name[i]; i++) {
			if (acpi_ns_valid_path_separator (external_name[i])) {
				num_segments++;
			}
		}
	}


	/* We need a segment to store the internal version of the name */

	internal_name = acpi_cm_callocate ((ACPI_NAME_SIZE * num_segments) + 4 + num_carats);
	if (!internal_name) {
		return (AE_NO_MEMORY);
	}


	/* Setup the correct prefixes, counts, and pointers */

	if (fully_qualified) {
		internal_name[0] = '\\';

		if (num_segments <= 1) {
			result = &internal_name[1];
		}
		else if (num_segments == 2) {
			internal_name[1] = AML_DUAL_NAME_PREFIX;
			result = &internal_name[2];
		}
		else {
			internal_name[1] = AML_MULTI_NAME_PREFIX_OP;
			internal_name[2] = (char) num_segments;
			result = &internal_name[3];
		}

	}

	else {
		/*
		 * Not fully qualified.
		 * Handle Carats first, then append the name segments
		 */

		i = 0;
		if (num_carats) {
			for (i = 0; i < num_carats; i++) {
				internal_name[i] = '^';
			}
		}

		if (num_segments == 1) {
			result = &internal_name[i];
		}

		else if (num_segments == 2) {
			internal_name[i] = AML_DUAL_NAME_PREFIX;
			result = &internal_name[i+1];
		}

		else {
			internal_name[i] = AML_MULTI_NAME_PREFIX_OP;
			internal_name[i+1] = (char) num_segments;
			result = &internal_name[i+2];
		}
	}


	/* Build the name (minus path separators) */

	for (; num_segments; num_segments--) {
		for (i = 0; i < ACPI_NAME_SIZE; i++) {
			if (acpi_ns_valid_path_separator (*external_name) ||
			   (*external_name == 0)) {
				/*
				 * Pad the segment with underscore(s) if
				 * segment is short
				 */

				result[i] = '_';
			}

			else {
				/* Convert s8 to uppercase and save it */

				result[i] = (char) TOUPPER (*external_name);
				external_name++;
			}

		}

		/* Now we must have a path separator, or the pathname is bad */

		if (!acpi_ns_valid_path_separator (*external_name) &&
			(*external_name != 0)) {
			acpi_cm_free (internal_name);
			return (AE_BAD_PARAMETER);
		}

		/* Move on the next segment */

		external_name++;
		result += ACPI_NAME_SIZE;
	}


	/* Return the completed name */

	/* Terminate the string! */
	*result = 0;
	*converted_name = internal_name;



	return (AE_OK);
}


/****************************************************************************
 *
 * FUNCTION:    Acpi_ns_externalize_name
 *
 * PARAMETERS:  *Internal_name         - Internal representation of name
 *              **Converted_name       - Where to return the resulting
 *                                        external representation of name
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Convert internal name (e.g. 5c 2f 02 5f 50 52 5f 43 50 55 30)
 *              to its external form (e.g. "\_PR_.CPU0")
 *
 ****************************************************************************/

ACPI_STATUS
acpi_ns_externalize_name (
	u32                     internal_name_length,
	char                    *internal_name,
	u32                     *converted_name_length,
	char                    **converted_name)
{
	u32                     prefix_length = 0;
	u32                     names_index = 0;
	u32                     names_count = 0;
	u32                     i = 0;
	u32                     j = 0;


	if (!internal_name_length   ||
		!internal_name          ||
		!converted_name_length  ||
		!converted_name) {
		return (AE_BAD_PARAMETER);
	}


	/*
	 * Check for a prefix (one '\' | one or more '^').
	 */
	switch (internal_name[0]) {
	case '\\':
		prefix_length = 1;
		break;

	case '^':
		for (i = 0; i < internal_name_length; i++) {
			if (internal_name[i] != '^') {
				prefix_length = i + 1;
			}
		}

		if (i == internal_name_length) {
			prefix_length = i;
		}

		break;
	}

	/*
	 * Check for object names.  Note that there could be 0-255 of these
	 * 4-byte elements.
	 */
	if (prefix_length < internal_name_length) {
		switch (internal_name[prefix_length]) {

		/* <count> 4-byte names */

		case AML_MULTI_NAME_PREFIX_OP:
			names_index = prefix_length + 2;
			names_count = (u32) internal_name[prefix_length + 1];
			break;


		/* two 4-byte names */

		case AML_DUAL_NAME_PREFIX:
			names_index = prefix_length + 1;
			names_count = 2;
			break;


		/* Null_name */

		case 0:
			names_index = 0;
			names_count = 0;
			break;


		/* one 4-byte name */

		default:
			names_index = prefix_length;