drivers/acpi/namespace/nsnames.c

   1 /*******************************************************************************
   2  *
   3  * Module Name: nsnames - Name manipulation and search
   4  *
   5  ******************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2005, 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
  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 *
 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
 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         if (!size) {
 206                 size = 1;       /* Root node case */
 207         }
 208
 209         return (size + 1);  /* +1 for null string terminator */
 210 }
 211
 212
 213 /*******************************************************************************
 214  *
 215  * FUNCTION:    acpi_ns_handle_to_pathname
 216  *
 217  * PARAMETERS:  target_handle           - Handle of named object whose name is
 218  *                                        to be found
 219  *              Buffer                  - Where the pathname is returned
 220  *
 221  * RETURN:      Status, Buffer is filled with pathname if status is AE_OK
 222  *
 223  * DESCRIPTION: Build and return a full namespace pathname
 224  *
 225  ******************************************************************************/
 226
 227 acpi_status
 228 acpi_ns_handle_to_pathname (
 229         acpi_handle                     target_handle,
 230         struct acpi_buffer              *buffer)
 231 {
 232         acpi_status                     status;
 233         struct acpi_namespace_node      *node;
 234         acpi_size                       required_size;
 235
 236
 237         ACPI_FUNCTION_TRACE_PTR ("ns_handle_to_pathname", target_handle);
 238
 239
 240         node = acpi_ns_map_handle_to_node (target_handle);
 241         if (!node) {
 242                 return_ACPI_STATUS (AE_BAD_PARAMETER);
 243         }
 244
 245         /* Determine size required for the caller buffer */
 246
 247         required_size = acpi_ns_get_pathname_length (node);
 248
 249         /* Validate/Allocate/Clear caller buffer */
 250
 251         status = acpi_ut_initialize_buffer (buffer, required_size);
 252         if (ACPI_FAILURE (status)) {
 253                 return_ACPI_STATUS (status);
 254         }
 255
 256         /* Build the path in the caller buffer */
 257
 258         acpi_ns_build_external_path (node, required_size, buffer->pointer);
 259
 260         ACPI_DEBUG_PRINT ((ACPI_DB_EXEC, "%s [%X] \n",
 261                 (char *) buffer->pointer, (u32) required_size));
 262         return_ACPI_STATUS (AE_OK);
 263 }
 264
 265