drivers/acpi/acpica/nsnames.c

   1 /*******************************************************************************
   2  *
   3  * Module Name: nsnames - Name manipulation and search
   4  *
   5  ******************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2017, 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         /* Validate the Node */
  93
  94         if (ACPI_GET_DESCRIPTOR_TYPE(node) != ACPI_DESC_TYPE_NAMED) {
  95                 ACPI_ERROR((AE_INFO,
  96                             "Invalid/cached reference target node: %p, descriptor type %d",
  97                             node, ACPI_GET_DESCRIPTOR_TYPE(node)));
  98                 return (0);
  99         }
 100
 101         size = acpi_ns_build_normalized_path(node, NULL, 0, FALSE);
 102         return (size);
 103 }
 104
 105 /*******************************************************************************
 106  *
 107  * FUNCTION:    acpi_ns_handle_to_name
 108  *
 109  * PARAMETERS:  target_handle           - Handle of named object whose name is
 110  *                                        to be found
 111  *              buffer                  - Where the name is returned
 112  *
 113  * RETURN:      Status, Buffer is filled with name if status is AE_OK
 114  *
 115  * DESCRIPTION: Build and return a full namespace name
 116  *
 117  ******************************************************************************/
 118
 119 acpi_status
 120 acpi_ns_handle_to_name(acpi_handle target_handle, struct acpi_buffer *buffer)
 121 {
 122         acpi_status status;
 123         struct acpi_namespace_node *node;
 124         const char *node_name;
 125
 126         ACPI_FUNCTION_TRACE_PTR(ns_handle_to_name, target_handle);
 127
 128         node = acpi_ns_validate_handle(target_handle);
 129         if (!node) {
 130                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 131         }
 132
 133         /* Validate/Allocate/Clear caller buffer */
 134
 135         status = acpi_ut_initialize_buffer(buffer, ACPI_PATH_SEGMENT_LENGTH);
 136         if (ACPI_FAILURE(status)) {
 137                 return_ACPI_STATUS(status);
 138         }
 139
 140         /* Just copy the ACPI name from the Node and zero terminate it */
 141
 142         node_name = acpi_ut_get_node_name(node);
 143         ACPI_MOVE_NAME(buffer->pointer, node_name);
 144         ((char *)buffer->pointer)[ACPI_NAME_SIZE] = 0;
 145
 146         ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "%4.4s\n", (char *)buffer->pointer));
 147         return_ACPI_STATUS(AE_OK);
 148 }
 149
 150 /*******************************************************************************
 151  *
 152  * FUNCTION:    acpi_ns_handle_to_pathname
 153  *
 154  * PARAMETERS:  target_handle           - Handle of named object whose name is
 155  *                                        to be found
 156  *              buffer                  - Where the pathname is returned
 157  *              no_trailing             - Remove trailing '_' for each name
 158  *                                        segment
 159  *
 160  * RETURN:      Status, Buffer is filled with pathname if status is AE_OK
 161  *
 162  * DESCRIPTION: Build and return a full namespace pathname
 163  *
 164  ******************************************************************************/
 165
 166 acpi_status
 167 acpi_ns_handle_to_pathname(acpi_handle target_handle,
 168                            struct acpi_buffer *buffer, u8 no_trailing)
 169 {
 170         acpi_status status;
 171         struct acpi_namespace_node *node;
 172         acpi_size required_size;
 173
 174         ACPI_FUNCTION_TRACE_PTR(ns_handle_to_pathname, target_handle);
 175
 176         node = acpi_ns_validate_handle(target_handle);
 177         if (!node) {
 178                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 179         }
 180
 181         /* Determine size required for the caller buffer */
 182
 183         required_size =
 184             acpi_ns_build_normalized_path(node, NULL, 0, no_trailing);
 185         if (!required_size) {
 186                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 187         }
 188
 189         /* Validate/Allocate/Clear caller buffer */
 190
 191         status = acpi_ut_initialize_buffer(buffer, required_size);
 192         if (ACPI_FAILURE(status)) {
 193                 return_ACPI_STATUS(status);
 194         }
 195
 196         /* Build the path in the caller buffer */
 197
 198         (void)acpi_ns_build_normalized_path(node, buffer->pointer,
 199                                             required_size, no_trailing);
 200
 201         ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "%s [%X]\n",
 202                           (char *)buffer->pointer, (u32) required_size));
 203         return_ACPI_STATUS(AE_OK);
 204 }
 205
 206 /*******************************************************************************
 207  *
 208  * FUNCTION:    acpi_ns_build_normalized_path
 209  *
 210  * PARAMETERS:  node        - Namespace node
 211  *              full_path   - Where the path name is returned
 212  *              path_size   - Size of returned path name buffer
 213  *              no_trailing - Remove trailing '_' from each name segment
 214  *
 215  * RETURN:      Return 1 if the AML path is empty, otherwise returning (length
 216  *              of pathname + 1) which means the 'FullPath' contains a trailing
 217  *              null.
 218  *
 219  * DESCRIPTION: Build and return a full namespace pathname.
 220  *              Note that if the size of 'FullPath' isn't large enough to
 221  *              contain the namespace node's path name, the actual required
 222  *              buffer length is returned, and it should be greater than
 223  *              'PathSize'. So callers are able to check the returning value
 224  *              to determine the buffer size of 'FullPath'.
 225  *
 226  ******************************************************************************/
 227
 228 u32
 229 acpi_ns_build_normalized_path(struct acpi_namespace_node *node,
 230                               char *full_path, u32 path_size, u8 no_trailing)
 231 {
 232         u32 length = 0, i;
 233         char name[ACPI_NAME_SIZE];
 234         u8 do_no_trailing;
 235         char c, *left, *right;
 236         struct acpi_namespace_node *next_node;
 237
 238         ACPI_FUNCTION_TRACE_PTR(ns_build_normalized_path, node);
 239
 240 #define ACPI_PATH_PUT8(path, size, byte, length)    \
 241         do {                                            \
 242                 if ((length) < (size))                      \
 243                 {                                           \
 244                         (path)[(length)] = (byte);              \
 245                 }                                           \
 246                 (length)++;                                 \
 247         } while (0)
 248
 249         /*
 250          * Make sure the path_size is correct, so that we don't need to
 251          * validate both full_path and path_size.
 252          */
 253         if (!full_path) {
 254                 path_size = 0;
 255         }
 256
 257         if (!node) {
 258                 goto build_trailing_null;
 259         }
 260
 261         next_node = node;
 262         while (next_node && next_node != acpi_gbl_root_node) {
 263                 if (next_node != node) {
 264                         ACPI_PATH_PUT8(full_path, path_size,
 265                                        AML_DUAL_NAME_PREFIX, length);
 266                 }
 267
 268                 ACPI_MOVE_32_TO_32(name, &next_node->name);
 269                 do_no_trailing = no_trailing;
 270                 for (i = 0; i < 4; i++) {
 271                         c = name[4 - i - 1];
 272                         if (do_no_trailing && c != '_') {
 273                                 do_no_trailing = FALSE;
 274                         }
 275                         if (!do_no_trailing) {
 276                                 ACPI_PATH_PUT8(full_path, path_size, c, length);
 277                         }
 278                 }
 279
 280                 next_node = next_node->parent;
 281         }
 282
 283         ACPI_PATH_PUT8(full_path, path_size, AML_ROOT_PREFIX, length);
 284
 285         /* Reverse the path string */
 286
 287         if (length <= path_size) {
 288                 left = full_path;
 289                 right = full_path + length - 1;
 290
 291                 while (left < right) {
 292                         c = *left;
 293                         *left++ = *right;
 294                         *right-- = c;
 295                 }
 296         }
 297
 298         /* Append the trailing null */
 299
 300 build_trailing_null:
 301         ACPI_PATH_PUT8(full_path, path_size, '\0', length);
 302
 303 #undef ACPI_PATH_PUT8
 304
 305         return_UINT32(length);
 306 }
 307
 308 /*******************************************************************************
 309  *
 310  * FUNCTION:    acpi_ns_get_normalized_pathname
 311  *
 312  * PARAMETERS:  node            - Namespace node whose pathname is needed
 313  *              no_trailing     - Remove trailing '_' from each name segment
 314  *
 315  * RETURN:      Pointer to storage containing the fully qualified name of
 316  *              the node, In external format (name segments separated by path
 317  *              separators.)
 318  *
 319  * DESCRIPTION: Used to obtain the full pathname to a namespace node, usually
 320  *              for error and debug statements. All trailing '_' will be
 321  *              removed from the full pathname if 'NoTrailing' is specified..
 322  *
 323  ******************************************************************************/
 324
 325 char *acpi_ns_get_normalized_pathname(struct acpi_namespace_node *node,
 326                                       u8 no_trailing)
 327 {
 328         char *name_buffer;
 329         acpi_size size;
 330
 331         ACPI_FUNCTION_TRACE_PTR(ns_get_normalized_pathname, node);
 332
 333         /* Calculate required buffer size based on depth below root */
 334
 335         size = acpi_ns_build_normalized_path(node, NULL, 0, no_trailing);
 336         if (!size) {
 337                 return_PTR(NULL);
 338         }
 339
 340         /* Allocate a buffer to be returned to caller */
 341
 342         name_buffer = ACPI_ALLOCATE_ZEROED(size);
 343         if (!name_buffer) {
 344                 ACPI_ERROR((AE_INFO, "Could not allocate %u bytes", (u32)size));
 345                 return_PTR(NULL);
 346         }
 347
 348         /* Build the path in the allocated buffer */
 349
 350         (void)acpi_ns_build_normalized_path(node, name_buffer, size,
 351                                             no_trailing);
 352
 353         return_PTR(name_buffer);
 354 }