nsnames.c revision 281075 
1/*******************************************************************************
2 *
3 * Module Name: nsnames - Name manipulation and search
4 *
5 ******************************************************************************/
6
7/*
8 * Copyright (C) 2000 - 2015, Intel Corp.
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#include <contrib/dev/acpica/include/acpi.h>
45#include <contrib/dev/acpica/include/accommon.h>
46#include <contrib/dev/acpica/include/amlcode.h>
47#include <contrib/dev/acpica/include/acnamesp.h>
48
49
50#define _COMPONENT          ACPI_NAMESPACE
51        ACPI_MODULE_NAME    ("nsnames")
52
53
54/*******************************************************************************
55 *
56 * FUNCTION:    AcpiNsBuildExternalPath
57 *
58 * PARAMETERS:  Node            - NS node whose pathname is needed
59 *              Size            - Size of the pathname
60 *              *NameBuffer     - Where to return the pathname
61 *
62 * RETURN:      Status
63 *              Places the pathname into the NameBuffer, in external format
64 *              (name segments separated by path separators)
65 *
66 * DESCRIPTION: Generate a full pathaname
67 *
68 ******************************************************************************/
69
70ACPI_STATUS
71AcpiNsBuildExternalPath (
72    ACPI_NAMESPACE_NODE     *Node,
73    ACPI_SIZE               Size,
74    char                    *NameBuffer)
75{
76    ACPI_SIZE               Index;
77    ACPI_NAMESPACE_NODE     *ParentNode;
78
79
80    ACPI_FUNCTION_ENTRY ();
81
82
83    /* Special case for root */
84
85    Index = Size - 1;
86    if (Index < ACPI_NAME_SIZE)
87    {
88        NameBuffer[0] = AML_ROOT_PREFIX;
89        NameBuffer[1] = 0;
90        return (AE_OK);
91    }
92
93    /* Store terminator byte, then build name backwards */
94
95    ParentNode = Node;
96    NameBuffer[Index] = 0;
97
98    while ((Index > ACPI_NAME_SIZE) && (ParentNode != AcpiGbl_RootNode))
99    {
100        Index -= ACPI_NAME_SIZE;
101
102        /* Put the name into the buffer */
103
104        ACPI_MOVE_32_TO_32 ((NameBuffer + Index), &ParentNode->Name);
105        ParentNode = ParentNode->Parent;
106
107        /* Prefix name with the path separator */
108
109        Index--;
110        NameBuffer[Index] = ACPI_PATH_SEPARATOR;
111    }
112
113    /* Overwrite final separator with the root prefix character */
114
115    NameBuffer[Index] = AML_ROOT_PREFIX;
116
117    if (Index != 0)
118    {
119        ACPI_ERROR ((AE_INFO,
120            "Could not construct external pathname; index=%u, size=%u, Path=%s",
121            (UINT32) Index, (UINT32) Size, &NameBuffer[Size]));
122
123        return (AE_BAD_PARAMETER);
124    }
125
126    return (AE_OK);
127}
128
129
130/*******************************************************************************
131 *
132 * FUNCTION:    AcpiNsGetExternalPathname
133 *
134 * PARAMETERS:  Node            - Namespace node whose pathname is needed
135 *
136 * RETURN:      Pointer to storage containing the fully qualified name of
137 *              the node, In external format (name segments separated by path
138 *              separators.)
139 *
140 * DESCRIPTION: Used to obtain the full pathname to a namespace node, usually
141 *              for error and debug statements.
142 *
143 ******************************************************************************/
144
145char *
146AcpiNsGetExternalPathname (
147    ACPI_NAMESPACE_NODE     *Node)
148{
149    ACPI_STATUS             Status;
150    char                    *NameBuffer;
151    ACPI_SIZE               Size;
152
153
154    ACPI_FUNCTION_TRACE_PTR (NsGetExternalPathname, Node);
155
156
157    /* Calculate required buffer size based on depth below root */
158
159    Size = AcpiNsGetPathnameLength (Node);
160    if (!Size)
161    {
162        return_PTR (NULL);
163    }
164
165    /* Allocate a buffer to be returned to caller */
166
167    NameBuffer = ACPI_ALLOCATE_ZEROED (Size);
168    if (!NameBuffer)
169    {
170        ACPI_ERROR ((AE_INFO, "Could not allocate %u bytes", (UINT32) Size));
171        return_PTR (NULL);
172    }
173
174    /* Build the path in the allocated buffer */
175
176    Status = AcpiNsBuildExternalPath (Node, Size, NameBuffer);
177    if (ACPI_FAILURE (Status))
178    {
179        ACPI_FREE (NameBuffer);
180        return_PTR (NULL);
181    }
182
183    return_PTR (NameBuffer);
184}
185
186
187/*******************************************************************************
188 *
189 * FUNCTION:    AcpiNsGetPathnameLength
190 *
191 * PARAMETERS:  Node        - Namespace node
192 *
193 * RETURN:      Length of path, including prefix
194 *
195 * DESCRIPTION: Get the length of the pathname string for this node
196 *
197 ******************************************************************************/
198
199ACPI_SIZE
200AcpiNsGetPathnameLength (
201    ACPI_NAMESPACE_NODE     *Node)
202{
203    ACPI_SIZE               Size;
204    ACPI_NAMESPACE_NODE     *NextNode;
205
206
207    ACPI_FUNCTION_ENTRY ();
208
209
210    /*
211     * Compute length of pathname as 5 * number of name segments.
212     * Go back up the parent tree to the root
213     */
214    Size = 0;
215    NextNode = Node;
216
217    while (NextNode && (NextNode != AcpiGbl_RootNode))
218    {
219        if (ACPI_GET_DESCRIPTOR_TYPE (NextNode) != ACPI_DESC_TYPE_NAMED)
220        {
221            ACPI_ERROR ((AE_INFO,
222                "Invalid Namespace Node (%p) while traversing namespace",
223                NextNode));
224            return (0);
225        }
226        Size += ACPI_PATH_SEGMENT_LENGTH;
227        NextNode = NextNode->Parent;
228    }
229
230    if (!Size)
231    {
232        Size = 1; /* Root node case */
233    }
234
235    return (Size + 1);  /* +1 for null string terminator */
236}
237
238
239/*******************************************************************************
240 *
241 * FUNCTION:    AcpiNsHandleToPathname
242 *
243 * PARAMETERS:  TargetHandle            - Handle of named object whose name is
244 *                                        to be found
245 *              Buffer                  - Where the pathname is returned
246 *
247 * RETURN:      Status, Buffer is filled with pathname if status is AE_OK
248 *
249 * DESCRIPTION: Build and return a full namespace pathname
250 *
251 ******************************************************************************/
252
253ACPI_STATUS
254AcpiNsHandleToPathname (
255    ACPI_HANDLE             TargetHandle,
256    ACPI_BUFFER             *Buffer)
257{
258    ACPI_STATUS             Status;
259    ACPI_NAMESPACE_NODE     *Node;
260    ACPI_SIZE               RequiredSize;
261
262
263    ACPI_FUNCTION_TRACE_PTR (NsHandleToPathname, TargetHandle);
264
265
266    Node = AcpiNsValidateHandle (TargetHandle);
267    if (!Node)
268    {
269        return_ACPI_STATUS (AE_BAD_PARAMETER);
270    }
271
272    /* Determine size required for the caller buffer */
273
274    RequiredSize = AcpiNsGetPathnameLength (Node);
275    if (!RequiredSize)
276    {
277        return_ACPI_STATUS (AE_BAD_PARAMETER);
278    }
279
280    /* Validate/Allocate/Clear caller buffer */
281
282    Status = AcpiUtInitializeBuffer (Buffer, RequiredSize);
283    if (ACPI_FAILURE (Status))
284    {
285        return_ACPI_STATUS (Status);
286    }
287
288    /* Build the path in the caller buffer */
289
290    Status = AcpiNsBuildExternalPath (Node, RequiredSize, Buffer->Pointer);
291    if (ACPI_FAILURE (Status))
292    {
293        return_ACPI_STATUS (Status);
294    }
295
296    ACPI_DEBUG_PRINT ((ACPI_DB_EXEC, "%s [%X]\n",
297        (char *) Buffer->Pointer, (UINT32) RequiredSize));
298    return_ACPI_STATUS (AE_OK);
299}
300