summaryrefslogtreecommitdiffstats
path: root/drivers/acpi/namespace/nsnames.c
blob: b7e301848ba7abe609a17d73fcaa1a23ac932f53 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
/*******************************************************************************
 *
 * Module Name: nsnames - Name manipulation and search
 *
 ******************************************************************************/

/*
 * Copyright (C) 2000 - 2008, Intel Corp.
 * 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/accommon.h>
#include <acpi/amlcode.h>
#include <acpi/acnamesp.h>

#define _COMPONENT          ACPI_NAMESPACE
ACPI_MODULE_NAME("nsnames")

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_build_external_path
 *
 * PARAMETERS:  Node            - NS node whose pathname is needed
 *              Size            - Size of the pathname
 *              *name_buffer    - Where to return the pathname
 *
 * RETURN:      Status
 *              Places the pathname into the name_buffer, in external format
 *              (name segments separated by path separators)
 *
 * DESCRIPTION: Generate a full pathaname
 *
 ******************************************************************************/
acpi_status
acpi_ns_build_external_path(struct acpi_namespace_node *node,
			    acpi_size size, char *name_buffer)
{
	acpi_size index;
	struct acpi_namespace_node *parent_node;

	ACPI_FUNCTION_ENTRY();

	/* Special case for root */

	index = size - 1;
	if (index < ACPI_NAME_SIZE) {
		name_buffer[0] = AML_ROOT_PREFIX;
		name_buffer[1] = 0;
		return (AE_OK);
	}

	/* Store terminator byte, then build name backwards */

	parent_node = node;
	name_buffer[index] = 0;

	while ((index > ACPI_NAME_SIZE) && (parent_node != acpi_gbl_root_node)) {
		index -= ACPI_NAME_SIZE;

		/* Put the name into the buffer */

		ACPI_MOVE_32_TO_32((name_buffer + index), &parent_node->name);
		parent_node = acpi_ns_get_parent_node(parent_node);

		/* Prefix name with the path separator */

		index--;
		name_buffer[index] = ACPI_PATH_SEPARATOR;
	}

	/* Overwrite final separator with the root prefix character */

	name_buffer[index] = AML_ROOT_PREFIX;

	if (index != 0) {
		ACPI_ERROR((AE_INFO,
			    "Could not construct external pathname; index=%X, size=%X, Path=%s",
			    (u32) index, (u32) size, &name_buffer[size]));

		return (AE_BAD_PARAMETER);
	}

	return (AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_get_external_pathname
 *
 * PARAMETERS:  Node            - Namespace node whose pathname is needed
 *
 * RETURN:      Pointer to storage containing the fully qualified name of
 *              the node, In external format (name segments separated by path
 *              separators.)
 *
 * DESCRIPTION: Used for debug printing in acpi_ns_search_table().
 *
 ******************************************************************************/

char *acpi_ns_get_external_pathname(struct acpi_namespace_node *node)
{
	acpi_status status;
	char *name_buffer;
	acpi_size size;

	ACPI_FUNCTION_TRACE_PTR(ns_get_external_pathname, node);

	/* Calculate required buffer size based on depth below root */

	size = acpi_ns_get_pathname_length(node);
	if (!size) {
		return_PTR(NULL);
	}

	/* Allocate a buffer to be returned to caller */

	name_buffer = ACPI_ALLOCATE_ZEROED(size);
	if (!name_buffer) {
		ACPI_ERROR((AE_INFO, "Allocation failure"));
		return_PTR(NULL);
	}

	/* Build the path in the allocated buffer */

	status = acpi_ns_build_external_path(node, size, name_buffer);
	if (ACPI_FAILURE(status)) {
		ACPI_FREE(name_buffer);
		return_PTR(NULL);
	}

	return_PTR(name_buffer);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_get_pathname_length
 *
 * PARAMETERS:  Node        - Namespace node
 *
 * RETURN:      Length of path, including prefix
 *
 * DESCRIPTION: Get the length of the pathname string for this node
 *
 ******************************************************************************/

acpi_size acpi_ns_get_pathname_length(struct acpi_namespace_node *node)
{
	acpi_size size;
	struct acpi_namespace_node *next_node;

	ACPI_FUNCTION_ENTRY();

	/*
	 * Compute length of pathname as 5 * number of name segments.
	 * Go back up the parent tree to the root
	 */
	size = 0;
	next_node = node;

	while (next_node && (next_node != acpi_gbl_root_node)) {
		if (ACPI_GET_DESCRIPTOR_TYPE(next_node) != ACPI_DESC_TYPE_NAMED) {
			ACPI_ERROR((AE_INFO,
				    "Invalid Namespace Node (%p) while traversing namespace",
				    next_node));
			return 0;
		}
		size += ACPI_PATH_SEGMENT_LENGTH;
		next_node = acpi_ns_get_parent_node(next_node);
	}

	if (!size) {
		size = 1;	/* Root node case */
	}

	return (size + 1);	/* +1 for null string terminator */
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_handle_to_pathname
 *
 * PARAMETERS:  target_handle           - Handle of named object whose name is
 *                                        to be found
 *              Buffer                  - Where the pathname is returned
 *
 * RETURN:      Status, Buffer is filled with pathname if status is AE_OK
 *
 * DESCRIPTION: Build and return a full namespace pathname
 *
 ******************************************************************************/

acpi_status
acpi_ns_handle_to_pathname(acpi_handle target_handle,
			   struct acpi_buffer * buffer)
{
	acpi_status status;
	struct acpi_namespace_node *node;
	acpi_size required_size;

	ACPI_FUNCTION_TRACE_PTR(ns_handle_to_pathname, target_handle);

	node = acpi_ns_map_handle_to_node(target_handle);
	if (!node) {
		return_ACPI_STATUS(AE_BAD_PARAMETER);
	}

	/* Determine size required for the caller buffer */

	required_size = acpi_ns_get_pathname_length(node);
	if (!required_size) {
		return_ACPI_STATUS(AE_BAD_PARAMETER);
	}

	/* Validate/Allocate/Clear caller buffer */

	status = acpi_ut_initialize_buffer(buffer, required_size);
	if (ACPI_FAILURE(status)) {
		return_ACPI_STATUS(status);
	}

	/* Build the path in the caller buffer */

	status =
	    acpi_ns_build_external_path(node, required_size, buffer->pointer);
	if (ACPI_FAILURE(status)) {
		return_ACPI_STATUS(status);
	}

	ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "%s [%X]\n",
			  (char *)buffer->pointer, (u32) required_size));
	return_ACPI_STATUS(AE_OK);
}