drivers/acpi/acpica/nsnames.c

   1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
   2 /*******************************************************************************
   3  *
   4  * Module Name: nsnames - Name manipulation and search
   5  *
   6  ******************************************************************************/
   7
   8 #include <acpi/acpi.h>
   9 #include "accommon.h"
  10 #include "amlcode.h"
  11 #include "acnamesp.h"
  12
  13 #define _COMPONENT          ACPI_NAMESPACE
  14 ACPI_MODULE_NAME("nsnames")
  15
  16 /*******************************************************************************
  17  *
  18  * FUNCTION:    acpi_ns_get_external_pathname
  19  *
  20  * PARAMETERS:  node            - Namespace node whose pathname is needed
  21  *
  22  * RETURN:      Pointer to storage containing the fully qualified name of
  23  *              the node, In external format (name segments separated by path
  24  *              separators.)
  25  *
  26  * DESCRIPTION: Used to obtain the full pathname to a namespace node, usually
  27  *              for error and debug statements.
  28  *
  29  ******************************************************************************/
  30 char *acpi_ns_get_external_pathname(struct acpi_namespace_node *node)
  31 {
  32         char *name_buffer;
  33
  34         ACPI_FUNCTION_TRACE_PTR(ns_get_external_pathname, node);
  35
  36         name_buffer = acpi_ns_get_normalized_pathname(node, FALSE);
  37         return_PTR(name_buffer);
  38 }
  39
  40 /*******************************************************************************
  41  *
  42  * FUNCTION:    acpi_ns_get_pathname_length
  43  *
  44  * PARAMETERS:  node        - Namespace node
  45  *
  46  * RETURN:      Length of path, including prefix
  47  *
  48  * DESCRIPTION: Get the length of the pathname string for this node
  49  *
  50  ******************************************************************************/
  51
  52 acpi_size acpi_ns_get_pathname_length(struct acpi_namespace_node *node)
  53 {
  54         acpi_size size;
  55
  56         /* Validate the Node */
  57
  58         if (ACPI_GET_DESCRIPTOR_TYPE(node) != ACPI_DESC_TYPE_NAMED) {
  59                 ACPI_ERROR((AE_INFO,
  60                             "Invalid/cached reference target node: %p, descriptor type %d",
  61                             node, ACPI_GET_DESCRIPTOR_TYPE(node)));
  62                 return (0);
  63         }
  64
  65         size = acpi_ns_build_normalized_path(node, NULL, 0, FALSE);
  66         return (size);
  67 }
  68
  69 /*******************************************************************************
  70  *
  71  * FUNCTION:    acpi_ns_handle_to_name
  72  *
  73  * PARAMETERS:  target_handle           - Handle of named object whose name is
  74  *                                        to be found
  75  *              buffer                  - Where the name is returned
  76  *
  77  * RETURN:      Status, Buffer is filled with name if status is AE_OK
  78  *
  79  * DESCRIPTION: Build and return a full namespace name
  80  *
  81  ******************************************************************************/
  82
  83 acpi_status
  84 acpi_ns_handle_to_name(acpi_handle target_handle, struct acpi_buffer *buffer)
  85 {
  86         acpi_status status;
  87         struct acpi_namespace_node *node;
  88         const char *node_name;
  89
  90         ACPI_FUNCTION_TRACE_PTR(ns_handle_to_name, target_handle);
  91
  92         node = acpi_ns_validate_handle(target_handle);
  93         if (!node) {
  94                 return_ACPI_STATUS(AE_BAD_PARAMETER);
  95         }
  96
  97         /* Validate/Allocate/Clear caller buffer */
  98
  99         status = acpi_ut_initialize_buffer(buffer, ACPI_PATH_SEGMENT_LENGTH);
 100         if (ACPI_FAILURE(status)) {
 101                 return_ACPI_STATUS(status);
 102         }
 103
 104         /* Just copy the ACPI name from the Node and zero terminate it */
 105
 106         node_name = acpi_ut_get_node_name(node);
 107         ACPI_COPY_NAMESEG(buffer->pointer, node_name);
 108         ((char *)buffer->pointer)[ACPI_NAMESEG_SIZE] = 0;
 109
 110         ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "%4.4s\n", (char *)buffer->pointer));
 111         return_ACPI_STATUS(AE_OK);
 112 }
 113
 114 /*******************************************************************************
 115  *
 116  * FUNCTION:    acpi_ns_handle_to_pathname
 117  *
 118  * PARAMETERS:  target_handle           - Handle of named object whose name is
 119  *                                        to be found
 120  *              buffer                  - Where the pathname is returned
 121  *              no_trailing             - Remove trailing '_' for each name
 122  *                                        segment
 123  *
 124  * RETURN:      Status, Buffer is filled with pathname if status is AE_OK
 125  *
 126  * DESCRIPTION: Build and return a full namespace pathname
 127  *
 128  ******************************************************************************/
 129
 130 acpi_status
 131 acpi_ns_handle_to_pathname(acpi_handle target_handle,
 132                            struct acpi_buffer *buffer, u8 no_trailing)
 133 {
 134         acpi_status status;
 135         struct acpi_namespace_node *node;
 136         acpi_size required_size;
 137
 138         ACPI_FUNCTION_TRACE_PTR(ns_handle_to_pathname, target_handle);
 139
 140         node = acpi_ns_validate_handle(target_handle);
 141         if (!node) {
 142                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 143         }
 144
 145         /* Determine size required for the caller buffer */
 146
 147         required_size =
 148             acpi_ns_build_normalized_path(node, NULL, 0, no_trailing);
 149         if (!required_size) {
 150                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 151         }
 152
 153         /* Validate/Allocate/Clear caller buffer */
 154
 155         status = acpi_ut_initialize_buffer(buffer, required_size);
 156         if (ACPI_FAILURE(status)) {
 157                 return_ACPI_STATUS(status);
 158         }
 159
 160         /* Build the path in the caller buffer */
 161
 162         (void)acpi_ns_build_normalized_path(node, buffer->pointer,
 163                                             required_size, no_trailing);
 164
 165         ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "%s [%X]\n",
 166                           (char *)buffer->pointer, (u32) required_size));
 167         return_ACPI_STATUS(AE_OK);
 168 }
 169
 170 /*******************************************************************************
 171  *
 172  * FUNCTION:    acpi_ns_build_normalized_path
 173  *
 174  * PARAMETERS:  node        - Namespace node
 175  *              full_path   - Where the path name is returned
 176  *              path_size   - Size of returned path name buffer
 177  *              no_trailing - Remove trailing '_' from each name segment
 178  *
 179  * RETURN:      Return 1 if the AML path is empty, otherwise returning (length
 180  *              of pathname + 1) which means the 'FullPath' contains a trailing
 181  *              null.
 182  *
 183  * DESCRIPTION: Build and return a full namespace pathname.
 184  *              Note that if the size of 'FullPath' isn't large enough to
 185  *              contain the namespace node's path name, the actual required
 186  *              buffer length is returned, and it should be greater than
 187  *              'PathSize'. So callers are able to check the returning value
 188  *              to determine the buffer size of 'FullPath'.
 189  *
 190  ******************************************************************************/
 191
 192 u32
 193 acpi_ns_build_normalized_path(struct acpi_namespace_node *node,
 194                               char *full_path, u32 path_size, u8 no_trailing)
 195 {
 196         u32 length = 0, i;
 197         char name[ACPI_NAMESEG_SIZE];
 198         u8 do_no_trailing;
 199         char c, *left, *right;
 200         struct acpi_namespace_node *next_node;
 201
 202         ACPI_FUNCTION_TRACE_PTR(ns_build_normalized_path, node);
 203
 204 #define ACPI_PATH_PUT8(path, size, byte, length)    \
 205         do {                                            \
 206                 if ((length) < (size))                      \
 207                 {                                           \
 208                         (path)[(length)] = (byte);              \
 209                 }                                           \
 210                 (length)++;                                 \
 211         } while (0)
 212
 213         /*
 214          * Make sure the path_size is correct, so that we don't need to
 215          * validate both full_path and path_size.
 216          */
 217         if (!full_path) {
 218                 path_size = 0;
 219         }
 220
 221         if (!node) {
 222                 goto build_trailing_null;
 223         }
 224
 225         next_node = node;
 226         while (next_node && next_node != acpi_gbl_root_node) {
 227                 if (next_node != node) {
 228                         ACPI_PATH_PUT8(full_path, path_size,
 229                                        AML_DUAL_NAME_PREFIX, length);
 230                 }
 231
 232                 ACPI_MOVE_32_TO_32(name, &next_node->name);
 233                 do_no_trailing = no_trailing;
 234                 for (i = 0; i < 4; i++) {
 235                         c = name[4 - i - 1];
 236                         if (do_no_trailing && c != '_') {
 237                                 do_no_trailing = FALSE;
 238                         }
 239                         if (!do_no_trailing) {
 240                                 ACPI_PATH_PUT8(full_path, path_size, c, length);
 241                         }
 242                 }
 243
 244                 next_node = next_node->parent;
 245         }
 246
 247         ACPI_PATH_PUT8(full_path, path_size, AML_ROOT_PREFIX, length);
 248
 249         /* Reverse the path string */
 250
 251         if (length <= path_size) {
 252                 left = full_path;
 253                 right = full_path + length - 1;
 254
 255                 while (left < right) {
 256                         c = *left;
 257                         *left++ = *right;
 258                         *right-- = c;
 259                 }
 260         }
 261
 262         /* Append the trailing null */
 263
 264 build_trailing_null:
 265         ACPI_PATH_PUT8(full_path, path_size, '\0', length);
 266
 267 #undef ACPI_PATH_PUT8
 268
 269         return_UINT32(length);
 270 }
 271
 272 /*******************************************************************************
 273  *
 274  * FUNCTION:    acpi_ns_get_normalized_pathname
 275  *
 276  * PARAMETERS:  node            - Namespace node whose pathname is needed
 277  *              no_trailing     - Remove trailing '_' from each name segment
 278  *
 279  * RETURN:      Pointer to storage containing the fully qualified name of
 280  *              the node, In external format (name segments separated by path
 281  *              separators.)
 282  *
 283  * DESCRIPTION: Used to obtain the full pathname to a namespace node, usually
 284  *              for error and debug statements. All trailing '_' will be
 285  *              removed from the full pathname if 'NoTrailing' is specified..
 286  *
 287  ******************************************************************************/
 288
 289 char *acpi_ns_get_normalized_pathname(struct acpi_namespace_node *node,
 290                                       u8 no_trailing)
 291 {
 292         char *name_buffer;
 293         acpi_size size;
 294
 295         ACPI_FUNCTION_TRACE_PTR(ns_get_normalized_pathname, node);
 296
 297         /* Calculate required buffer size based on depth below root */
 298
 299         size = acpi_ns_build_normalized_path(node, NULL, 0, no_trailing);
 300         if (!size) {
 301                 return_PTR(NULL);
 302         }
 303
 304         /* Allocate a buffer to be returned to caller */
 305
 306         name_buffer = ACPI_ALLOCATE_ZEROED(size);
 307         if (!name_buffer) {
 308                 ACPI_ERROR((AE_INFO, "Could not allocate %u bytes", (u32)size));
 309                 return_PTR(NULL);
 310         }
 311
 312         /* Build the path in the allocated buffer */
 313
 314         (void)acpi_ns_build_normalized_path(node, name_buffer, size,
 315                                             no_trailing);
 316
 317         ACPI_DEBUG_PRINT_RAW((ACPI_DB_NAMES, "%s: Path \"%s\"\n",
 318                               ACPI_GET_FUNCTION_NAME, name_buffer));
 319
 320         return_PTR(name_buffer);
 321 }
 322
 323 /*******************************************************************************
 324  *
 325  * FUNCTION:    acpi_ns_build_prefixed_pathname
 326  *
 327  * PARAMETERS:  prefix_scope        - Scope/Path that prefixes the internal path
 328  *              internal_path       - Name or path of the namespace node
 329  *
 330  * RETURN:      None
 331  *
 332  * DESCRIPTION: Construct a fully qualified pathname from a concatenation of:
 333  *              1) Path associated with the prefix_scope namespace node
 334  *              2) External path representation of the Internal path
 335  *
 336  ******************************************************************************/
 337
 338 char *acpi_ns_build_prefixed_pathname(union acpi_generic_state *prefix_scope,
 339                                       const char *internal_path)
 340 {
 341         acpi_status status;
 342         char *full_path = NULL;
 343         char *external_path = NULL;
 344         char *prefix_path = NULL;
 345         u32 prefix_path_length = 0;
 346
 347         /* If there is a prefix, get the pathname to it */
 348
 349         if (prefix_scope && prefix_scope->scope.node) {
 350                 prefix_path =
 351                     acpi_ns_get_normalized_pathname(prefix_scope->scope.node,
 352                                                     TRUE);
 353                 if (prefix_path) {
 354                         prefix_path_length = strlen(prefix_path);
 355                 }
 356         }
 357
 358         status = acpi_ns_externalize_name(ACPI_UINT32_MAX, internal_path,
 359                                           NULL, &external_path);
 360         if (ACPI_FAILURE(status)) {
 361                 goto cleanup;
 362         }
 363
 364         /* Merge the prefix path and the path. 2 is for one dot and trailing null */
 365
 366         full_path =
 367             ACPI_ALLOCATE_ZEROED(prefix_path_length + strlen(external_path) +
 368                                  2);
 369         if (!full_path) {
 370                 goto cleanup;
 371         }
 372
 373         /* Don't merge if the External path is already fully qualified */
 374
 375         if (prefix_path && (*external_path != '\\') && (*external_path != '^')) {
 376                 strcat(full_path, prefix_path);
 377                 if (prefix_path[1]) {
 378                         strcat(full_path, ".");
 379                 }
 380         }
 381
 382         acpi_ns_normalize_pathname(external_path);
 383         strcat(full_path, external_path);
 384
 385 cleanup:
 386         if (prefix_path) {
 387                 ACPI_FREE(prefix_path);
 388         }
 389         if (external_path) {
 390                 ACPI_FREE(external_path);
 391         }
 392
 393         return (full_path);
 394 }
 395
 396 /*******************************************************************************
 397  *
 398  * FUNCTION:    acpi_ns_normalize_pathname
 399  *
 400  * PARAMETERS:  original_path       - Path to be normalized, in External format
 401  *
 402  * RETURN:      The original path is processed in-place
 403  *
 404  * DESCRIPTION: Remove trailing underscores from each element of a path.
 405  *
 406  *              For example:  \A___.B___.C___ becomes \A.B.C
 407  *
 408  ******************************************************************************/
 409
 410 void acpi_ns_normalize_pathname(char *original_path)
 411 {
 412         char *input_path = original_path;
 413         char *new_path_buffer;
 414         char *new_path;
 415         u32 i;
 416
 417         /* Allocate a temp buffer in which to construct the new path */
 418
 419         new_path_buffer = ACPI_ALLOCATE_ZEROED(strlen(input_path) + 1);
 420         new_path = new_path_buffer;
 421         if (!new_path_buffer) {
 422                 return;
 423         }
 424
 425         /* Special characters may appear at the beginning of the path */
 426
 427         if (*input_path == '\\') {
 428                 *new_path = *input_path;
 429                 new_path++;
 430                 input_path++;
 431         }
 432
 433         while (*input_path == '^') {
 434                 *new_path = *input_path;
 435                 new_path++;
 436                 input_path++;
 437         }
 438
 439         /* Remainder of the path */
 440
 441         while (*input_path) {
 442
 443                 /* Do one nameseg at a time */
 444
 445                 for (i = 0; (i < ACPI_NAMESEG_SIZE) && *input_path; i++) {
 446                         if ((i == 0) || (*input_path != '_')) { /* First char is allowed to be underscore */
 447                                 *new_path = *input_path;
 448                                 new_path++;
 449                         }
 450
 451                         input_path++;
 452                 }
 453
 454                 /* Dot means that there are more namesegs to come */
 455
 456                 if (*input_path == '.') {
 457                         *new_path = *input_path;
 458                         new_path++;
 459                         input_path++;
 460                 }
 461         }
 462
 463         *new_path = 0;
 464         strcpy(original_path, new_path_buffer);
 465         ACPI_FREE(new_path_buffer);
 466 }