drivers/acpi/acpica/nsnames.c

   1 /*******************************************************************************
   2  *
   3  * Module Name: nsnames - Name manipulation and search
   4  *
   5  ******************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2016, 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 <acpi/acpi.h>
  45 #include "accommon.h"
  46 #include "amlcode.h"
  47 #include "acnamesp.h"
  48
  49 #define _COMPONENT          ACPI_NAMESPACE
  50 ACPI_MODULE_NAME("nsnames")
  51
  52 /*******************************************************************************
  53  *
  54  * FUNCTION:    acpi_ns_get_external_pathname
  55  *
  56  * PARAMETERS:  node            - Namespace node whose pathname is needed
  57  *
  58  * RETURN:      Pointer to storage containing the fully qualified name of
  59  *              the node, In external format (name segments separated by path
  60  *              separators.)
  61  *
  62  * DESCRIPTION: Used to obtain the full pathname to a namespace node, usually
  63  *              for error and debug statements.
  64  *
  65  ******************************************************************************/
  66 char *acpi_ns_get_external_pathname(struct acpi_namespace_node *node)
  67 {
  68         char *name_buffer;
  69
  70         ACPI_FUNCTION_TRACE_PTR(ns_get_external_pathname, node);
  71
  72         name_buffer = acpi_ns_get_normalized_pathname(node, FALSE);
  73         return_PTR(name_buffer);
  74 }
  75
  76 /*******************************************************************************
  77  *
  78  * FUNCTION:    acpi_ns_get_pathname_length
  79  *
  80  * PARAMETERS:  node        - Namespace node
  81  *
  82  * RETURN:      Length of path, including prefix
  83  *
  84  * DESCRIPTION: Get the length of the pathname string for this node
  85  *
  86  ******************************************************************************/
  87
  88 acpi_size acpi_ns_get_pathname_length(struct acpi_namespace_node *node)
  89 {
  90         acpi_size size;
  91
  92         ACPI_FUNCTION_ENTRY();
  93
  94         size = acpi_ns_build_normalized_path(node, NULL, 0, FALSE);
  95         return (size);
  96 }
  97
  98 /*******************************************************************************
  99  *
 100  * FUNCTION:    acpi_ns_handle_to_name
 101  *
 102  * PARAMETERS:  target_handle           - Handle of named object whose name is
 103  *                                        to be found
 104  *              buffer                  - Where the name is returned
 105  *
 106  * RETURN:      Status, Buffer is filled with name if status is AE_OK
 107  *
 108  * DESCRIPTION: Build and return a full namespace name
 109  *
 110  ******************************************************************************/
 111
 112 acpi_status
 113 acpi_ns_handle_to_name(acpi_handle target_handle, struct acpi_buffer *buffer)
 114 {
 115         acpi_status status;
 116         struct acpi_namespace_node *node;
 117         const char *node_name;
 118
 119         ACPI_FUNCTION_TRACE_PTR(ns_handle_to_name, target_handle);
 120
 121         node = acpi_ns_validate_handle(target_handle);
 122         if (!node) {
 123                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 124         }
 125
 126         /* Validate/Allocate/Clear caller buffer */
 127
 128         status = acpi_ut_initialize_buffer(buffer, ACPI_PATH_SEGMENT_LENGTH);
 129         if (ACPI_FAILURE(status)) {
 130                 return_ACPI_STATUS(status);
 131         }
 132
 133         /* Just copy the ACPI name from the Node and zero terminate it */
 134
 135         node_name = acpi_ut_get_node_name(node);
 136         ACPI_MOVE_NAME(buffer->pointer, node_name);
 137         ((char *)buffer->pointer)[ACPI_NAME_SIZE] = 0;
 138
 139         ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "%4.4s\n", (char *)buffer->pointer));
 140         return_ACPI_STATUS(AE_OK);
 141 }
 142
 143 /*******************************************************************************
 144  *
 145  * FUNCTION:    acpi_ns_handle_to_pathname
 146  *
 147  * PARAMETERS:  target_handle           - Handle of named object whose name is
 148  *                                        to be found
 149  *              buffer                  - Where the pathname is returned
 150  *              no_trailing             - Remove trailing '_' for each name
 151  *                                        segment
 152  *
 153  * RETURN:      Status, Buffer is filled with pathname if status is AE_OK
 154  *
 155  * DESCRIPTION: Build and return a full namespace pathname
 156  *
 157  ******************************************************************************/
 158
 159 acpi_status
 160 acpi_ns_handle_to_pathname(acpi_handle target_handle,
 161                            struct acpi_buffer *buffer, u8 no_trailing)
 162 {
 163         acpi_status status;
 164         struct acpi_namespace_node *node;
 165         acpi_size required_size;
 166
 167         ACPI_FUNCTION_TRACE_PTR(ns_handle_to_pathname, target_handle);
 168
 169         node = acpi_ns_validate_handle(target_handle);
 170         if (!node) {
 171                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 172         }
 173
 174         /* Determine size required for the caller buffer */
 175
 176         required_size =
 177             acpi_ns_build_normalized_path(node, NULL, 0, no_trailing);
 178         if (!required_size) {
 179                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 180         }
 181
 182         /* Validate/Allocate/Clear caller buffer */
 183
 184         status = acpi_ut_initialize_buffer(buffer, required_size);
 185         if (ACPI_FAILURE(status)) {
 186                 return_ACPI_STATUS(status);
 187         }
 188
 189         /* Build the path in the caller buffer */
 190
 191         (void)acpi_ns_build_normalized_path(node, buffer->pointer,
 192                                             required_size, no_trailing);
 193         if (ACPI_FAILURE(status)) {
 194                 return_ACPI_STATUS(status);
 195         }
 196
 197         ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "%s [%X]\n",
 198                           (char *)buffer->pointer, (u32) required_size));
 199         return_ACPI_STATUS(AE_OK);
 200 }
 201
 202 /*******************************************************************************
 203  *
 204  * FUNCTION:    acpi_ns_build_normalized_path
 205  *
 206  * PARAMETERS:  node        - Namespace node
 207  *              full_path   - Where the path name is returned
 208  *              path_size   - Size of returned path name buffer
 209  *              no_trailing - Remove trailing '_' from each name segment
 210  *
 211  * RETURN:      Return 1 if the AML path is empty, otherwise returning (length
 212  *              of pathname + 1) which means the 'FullPath' contains a trailing
 213  *              null.
 214  *
 215  * DESCRIPTION: Build and return a full namespace pathname.
 216  *              Note that if the size of 'FullPath' isn't large enough to
 217  *              contain the namespace node's path name, the actual required
 218  *              buffer length is returned, and it should be greater than
 219  *              'PathSize'. So callers are able to check the returning value
 220  *              to determine the buffer size of 'FullPath'.
 221  *
 222  ******************************************************************************/
 223
 224 u32
 225 acpi_ns_build_normalized_path(struct acpi_namespace_node *node,
 226                               char *full_path, u32 path_size, u8 no_trailing)
 227 {
 228         u32 length = 0, i;
 229         char name[ACPI_NAME_SIZE];
 230         u8 do_no_trailing;
 231         char c, *left, *right;
 232         struct acpi_namespace_node *next_node;
 233
 234         ACPI_FUNCTION_TRACE_PTR(ns_build_normalized_path, node);
 235
 236 #define ACPI_PATH_PUT8(path, size, byte, length)    \
 237         do {                                            \
 238                 if ((length) < (size))                      \
 239                 {                                           \
 240                         (path)[(length)] = (byte);              \
 241                 }                                           \
 242                 (length)++;                                 \
 243         } while (0)
 244
 245         /*
 246          * Make sure the path_size is correct, so that we don't need to
 247          * validate both full_path and path_size.
 248          */
 249         if (!full_path) {
 250                 path_size = 0;
 251         }
 252
 253         if (!node) {
 254                 goto build_trailing_null;
 255         }
 256
 257         next_node = node;
 258         while (next_node && next_node != acpi_gbl_root_node) {
 259                 if (next_node != node) {
 260                         ACPI_PATH_PUT8(full_path, path_size,
 261                                        AML_DUAL_NAME_PREFIX, length);
 262                 }
 263
 264                 ACPI_MOVE_32_TO_32(name, &next_node->name);
 265                 do_no_trailing = no_trailing;
 266                 for (i = 0; i < 4; i++) {
 267                         c = name[4 - i - 1];
 268                         if (do_no_trailing && c != '_') {
 269                                 do_no_trailing = FALSE;
 270                         }
 271                         if (!do_no_trailing) {
 272                                 ACPI_PATH_PUT8(full_path, path_size, c, length);
 273                         }
 274                 }
 275
 276                 next_node = next_node->parent;
 277         }
 278
 279         ACPI_PATH_PUT8(full_path, path_size, AML_ROOT_PREFIX, length);
 280
 281         /* Reverse the path string */
 282
 283         if (length <= path_size) {
 284                 left = full_path;
 285                 right = full_path + length - 1;
 286
 287                 while (left < right) {
 288                         c = *left;
 289                         *left++ = *right;
 290                         *right-- = c;
 291                 }
 292         }
 293
 294         /* Append the trailing null */
 295
 296 build_trailing_null:
 297         ACPI_PATH_PUT8(full_path, path_size, '\0', length);
 298
 299 #undef ACPI_PATH_PUT8
 300
 301         return_UINT32(length);
 302 }
 303
 304 /*******************************************************************************
 305  *
 306  * FUNCTION:    acpi_ns_get_normalized_pathname
 307  *
 308  * PARAMETERS:  node            - Namespace node whose pathname is needed
 309  *              no_trailing     - Remove trailing '_' from each name segment
 310  *
 311  * RETURN:      Pointer to storage containing the fully qualified name of
 312  *              the node, In external format (name segments separated by path
 313  *              separators.)
 314  *
 315  * DESCRIPTION: Used to obtain the full pathname to a namespace node, usually
 316  *              for error and debug statements. All trailing '_' will be
 317  *              removed from the full pathname if 'NoTrailing' is specified..
 318  *
 319  ******************************************************************************/
 320
 321 char *acpi_ns_get_normalized_pathname(struct acpi_namespace_node *node,
 322                                       u8 no_trailing)
 323 {
 324         char *name_buffer;
 325         acpi_size size;
 326
 327         ACPI_FUNCTION_TRACE_PTR(ns_get_normalized_pathname, node);
 328
 329         /* Calculate required buffer size based on depth below root */
 330
 331         size = acpi_ns_build_normalized_path(node, NULL, 0, no_trailing);
 332         if (!size) {
 333                 return_PTR(NULL);
 334         }
 335
 336         /* Allocate a buffer to be returned to caller */
 337
 338         name_buffer = ACPI_ALLOCATE_ZEROED(size);
 339         if (!name_buffer) {
 340                 ACPI_ERROR((AE_INFO, "Could not allocate %u bytes", (u32)size));
 341                 return_PTR(NULL);
 342         }
 343
 344         /* Build the path in the allocated buffer */
 345
 346         (void)acpi_ns_build_normalized_path(node, name_buffer, size,
 347                                             no_trailing);
 348
 349         return_PTR(name_buffer);
 350 }