1 /*******************************************************************************
2  *
3  * Module Name: nsnames - Name manipulation and search
4  *
5  ******************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2004, R. Byron Moore
9  * All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions, and the following disclaimer,
16  *    without modification.
17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
18  *    substantially similar to the "NO WARRANTY" disclaimer below
19  *    ("Disclaimer") and any redistribution must be conditioned upon
20  *    including a substantially similar Disclaimer requirement for further
21  *    binary redistribution.
22  * 3. Neither the names of the above-listed copyright holders nor the names
23  *    of any contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * Alternatively, this software may be distributed under the terms of the
27  * GNU General Public License ("GPL") version 2 as published by the Free
28  * Software Foundation.
29  *
30  * NO WARRANTY
31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
41  * POSSIBILITY OF SUCH DAMAGES.
42  */
43 
44 
45 #include <acpi/acpi.h>
46 #include <acpi/amlcode.h>
47 #include <acpi/acnamesp.h>
48 
49 
50 #define _COMPONENT          ACPI_NAMESPACE
51 	 ACPI_MODULE_NAME    ("nsnames")
52 
53 
54 /*******************************************************************************
55  *
56  * FUNCTION:    acpi_ns_build_external_path
57  *
58  * PARAMETERS:  Node            - NS node whose pathname is needed
59  *              Size            - Size of the pathname
60  *              *name_buffer    - Where to return the pathname
61  *
62  * RETURN:      Places the pathname into the name_buffer, in external format
63  *              (name segments separated by path separators)
64  *
65  * DESCRIPTION: Generate a full pathaname
66  *
67  ******************************************************************************/
68 
69 void
acpi_ns_build_external_path(struct acpi_namespace_node * node,acpi_size size,char * name_buffer)70 acpi_ns_build_external_path (
71 	struct acpi_namespace_node      *node,
72 	acpi_size                       size,
73 	char                            *name_buffer)
74 {
75 	acpi_size                       index;
76 	struct acpi_namespace_node      *parent_node;
77 
78 
79 	ACPI_FUNCTION_NAME ("ns_build_external_path");
80 
81 
82 	/* Special case for root */
83 
84 	index = size - 1;
85 	if (index < ACPI_NAME_SIZE) {
86 		name_buffer[0] = AML_ROOT_PREFIX;
87 		name_buffer[1] = 0;
88 		return;
89 	}
90 
91 	/* Store terminator byte, then build name backwards */
92 
93 	parent_node = node;
94 	name_buffer[index] = 0;
95 
96 	while ((index > ACPI_NAME_SIZE) && (parent_node != acpi_gbl_root_node)) {
97 		index -= ACPI_NAME_SIZE;
98 
99 		/* Put the name into the buffer */
100 
101 		ACPI_MOVE_32_TO_32 ((name_buffer + index), &parent_node->name);
102 		parent_node = acpi_ns_get_parent_node (parent_node);
103 
104 		/* Prefix name with the path separator */
105 
106 		index--;
107 		name_buffer[index] = ACPI_PATH_SEPARATOR;
108 	}
109 
110 	/* Overwrite final separator with the root prefix character */
111 
112 	name_buffer[index] = AML_ROOT_PREFIX;
113 
114 	if (index != 0) {
115 		ACPI_DEBUG_PRINT ((ACPI_DB_ERROR,
116 			"Could not construct pathname; index=%X, size=%X, Path=%s\n",
117 			(u32) index, (u32) size, &name_buffer[size]));
118 	}
119 
120 	return;
121 }
122 
123 
124 #ifdef ACPI_DEBUG_OUTPUT
125 /*******************************************************************************
126  *
127  * FUNCTION:    acpi_ns_get_external_pathname
128  *
129  * PARAMETERS:  Node            - NS node whose pathname is needed
130  *
131  * RETURN:      Pointer to storage containing the fully qualified name of
132  *              the node, In external format (name segments separated by path
133  *              separators.)
134  *
135  * DESCRIPTION: Used for debug printing in acpi_ns_search_table().
136  *
137  ******************************************************************************/
138 
139 char *
acpi_ns_get_external_pathname(struct acpi_namespace_node * node)140 acpi_ns_get_external_pathname (
141 	struct acpi_namespace_node      *node)
142 {
143 	char                            *name_buffer;
144 	acpi_size                       size;
145 
146 
147 	ACPI_FUNCTION_TRACE_PTR ("ns_get_external_pathname", node);
148 
149 
150 	/* Calculate required buffer size based on depth below root */
151 
152 	size = acpi_ns_get_pathname_length (node);
153 
154 	/* Allocate a buffer to be returned to caller */
155 
156 	name_buffer = ACPI_MEM_CALLOCATE (size);
157 	if (!name_buffer) {
158 		ACPI_REPORT_ERROR (("ns_get_table_pathname: allocation failure\n"));
159 		return_PTR (NULL);
160 	}
161 
162 	/* Build the path in the allocated buffer */
163 
164 	acpi_ns_build_external_path (node, size, name_buffer);
165 	return_PTR (name_buffer);
166 }
167 #endif
168 
169 
170 /*******************************************************************************
171  *
172  * FUNCTION:    acpi_ns_get_pathname_length
173  *
174  * PARAMETERS:  Node        - Namespace node
175  *
176  * RETURN:      Length of path, including prefix
177  *
178  * DESCRIPTION: Get the length of the pathname string for this node
179  *
180  ******************************************************************************/
181 
182 acpi_size
acpi_ns_get_pathname_length(struct acpi_namespace_node * node)183 acpi_ns_get_pathname_length (
184 	struct acpi_namespace_node      *node)
185 {
186 	acpi_size                       size;
187 	struct acpi_namespace_node      *next_node;
188 
189 
190 	ACPI_FUNCTION_ENTRY ();
191 
192 
193 	/*
194 	 * Compute length of pathname as 5 * number of name segments.
195 	 * Go back up the parent tree to the root
196 	 */
197 	size = 0;
198 	next_node = node;
199 
200 	while (next_node && (next_node != acpi_gbl_root_node)) {
201 		size += ACPI_PATH_SEGMENT_LENGTH;
202 		next_node = acpi_ns_get_parent_node (next_node);
203 	}
204 
205 	return (size + 1);
206 }
207 
208 
209 /*******************************************************************************
210  *
211  * FUNCTION:    acpi_ns_handle_to_pathname
212  *
213  * PARAMETERS:  target_handle           - Handle of named object whose name is
214  *                                        to be found
215  *              Buffer                  - Where the pathname is returned
216  *
217  * RETURN:      Status, Buffer is filled with pathname if status is AE_OK
218  *
219  * DESCRIPTION: Build and return a full namespace pathname
220  *
221  ******************************************************************************/
222 
223 acpi_status
acpi_ns_handle_to_pathname(acpi_handle target_handle,struct acpi_buffer * buffer)224 acpi_ns_handle_to_pathname (
225 	acpi_handle                     target_handle,
226 	struct acpi_buffer              *buffer)
227 {
228 	acpi_status                     status;
229 	struct acpi_namespace_node      *node;
230 	acpi_size                       required_size;
231 
232 
233 	ACPI_FUNCTION_TRACE_PTR ("ns_handle_to_pathname", target_handle);
234 
235 
236 	node = acpi_ns_map_handle_to_node (target_handle);
237 	if (!node) {
238 		return_ACPI_STATUS (AE_BAD_PARAMETER);
239 	}
240 
241 	/* Determine size required for the caller buffer */
242 
243 	required_size = acpi_ns_get_pathname_length (node);
244 
245 	/* Validate/Allocate/Clear caller buffer */
246 
247 	status = acpi_ut_initialize_buffer (buffer, required_size);
248 	if (ACPI_FAILURE (status)) {
249 		return_ACPI_STATUS (status);
250 	}
251 
252 	/* Build the path in the caller buffer */
253 
254 	acpi_ns_build_external_path (node, required_size, buffer->pointer);
255 
256 	ACPI_DEBUG_PRINT ((ACPI_DB_EXEC, "%s [%X] \n", (char *) buffer->pointer, (u32) required_size));
257 	return_ACPI_STATUS (AE_OK);
258 }
259 
260 
261