drivers/acpi/acpica/nsnames.c

   1 /*******************************************************************************
   2  *
   3  * Module Name: nsnames - Name manipulation and search
   4  *
   5  ******************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2018, 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 /* Local Prototypes */
  53 static void acpi_ns_normalize_pathname(char *original_path);
  54
  55 /*******************************************************************************
  56  *
  57  * FUNCTION:    acpi_ns_get_external_pathname
  58  *
  59  * PARAMETERS:  node            - Namespace node whose pathname is needed
  60  *
  61  * RETURN:      Pointer to storage containing the fully qualified name of
  62  *              the node, In external format (name segments separated by path
  63  *              separators.)
  64  *
  65  * DESCRIPTION: Used to obtain the full pathname to a namespace node, usually
  66  *              for error and debug statements.
  67  *
  68  ******************************************************************************/
  69
  70 char *acpi_ns_get_external_pathname(struct acpi_namespace_node *node)
  71 {
  72         char *name_buffer;
  73
  74         ACPI_FUNCTION_TRACE_PTR(ns_get_external_pathname, node);
  75
  76         name_buffer = acpi_ns_get_normalized_pathname(node, FALSE);
  77         return_PTR(name_buffer);
  78 }
  79
  80 /*******************************************************************************
  81  *
  82  * FUNCTION:    acpi_ns_get_pathname_length
  83  *
  84  * PARAMETERS:  node        - Namespace node
  85  *
  86  * RETURN:      Length of path, including prefix
  87  *
  88  * DESCRIPTION: Get the length of the pathname string for this node
  89  *
  90  ******************************************************************************/
  91
  92 acpi_size acpi_ns_get_pathname_length(struct acpi_namespace_node *node)
  93 {
  94         acpi_size size;
  95
  96         /* Validate the Node */
  97
  98         if (ACPI_GET_DESCRIPTOR_TYPE(node) != ACPI_DESC_TYPE_NAMED) {
  99                 ACPI_ERROR((AE_INFO,
 100                             "Invalid/cached reference target node: %p, descriptor type %d",
 101                             node, ACPI_GET_DESCRIPTOR_TYPE(node)));
 102                 return (0);
 103         }
 104
 105         size = acpi_ns_build_normalized_path(node, NULL, 0, FALSE);
 106         return (size);
 107 }
 108
 109 /*******************************************************************************
 110  *
 111  * FUNCTION:    acpi_ns_handle_to_name
 112  *
 113  * PARAMETERS:  target_handle           - Handle of named object whose name is
 114  *                                        to be found
 115  *              buffer                  - Where the name is returned
 116  *
 117  * RETURN:      Status, Buffer is filled with name if status is AE_OK
 118  *
 119  * DESCRIPTION: Build and return a full namespace name
 120  *
 121  ******************************************************************************/
 122
 123 acpi_status
 124 acpi_ns_handle_to_name(acpi_handle target_handle, struct acpi_buffer *buffer)
 125 {
 126         acpi_status status;
 127         struct acpi_namespace_node *node;
 128         const char *node_name;
 129
 130         ACPI_FUNCTION_TRACE_PTR(ns_handle_to_name, target_handle);
 131
 132         node = acpi_ns_validate_handle(target_handle);
 133         if (!node) {
 134                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 135         }
 136
 137         /* Validate/Allocate/Clear caller buffer */
 138
 139         status = acpi_ut_initialize_buffer(buffer, ACPI_PATH_SEGMENT_LENGTH);
 140         if (ACPI_FAILURE(status)) {
 141                 return_ACPI_STATUS(status);
 142         }
 143
 144         /* Just copy the ACPI name from the Node and zero terminate it */
 145
 146         node_name = acpi_ut_get_node_name(node);
 147         ACPI_MOVE_NAME(buffer->pointer, node_name);
 148         ((char *)buffer->pointer)[ACPI_NAME_SIZE] = 0;
 149
 150         ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "%4.4s\n", (char *)buffer->pointer));
 151         return_ACPI_STATUS(AE_OK);
 152 }
 153
 154 /*******************************************************************************
 155  *
 156  * FUNCTION:    acpi_ns_handle_to_pathname
 157  *
 158  * PARAMETERS:  target_handle           - Handle of named object whose name is
 159  *                                        to be found
 160  *              buffer                  - Where the pathname is returned
 161  *              no_trailing             - Remove trailing '_' for each name
 162  *                                        segment
 163  *
 164  * RETURN:      Status, Buffer is filled with pathname if status is AE_OK
 165  *
 166  * DESCRIPTION: Build and return a full namespace pathname
 167  *
 168  ******************************************************************************/
 169
 170 acpi_status
 171 acpi_ns_handle_to_pathname(acpi_handle target_handle,
 172                            struct acpi_buffer *buffer, u8 no_trailing)
 173 {
 174         acpi_status status;
 175         struct acpi_namespace_node *node;
 176         acpi_size required_size;
 177
 178         ACPI_FUNCTION_TRACE_PTR(ns_handle_to_pathname, target_handle);
 179
 180         node = acpi_ns_validate_handle(target_handle);
 181         if (!node) {
 182                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 183         }
 184
 185         /* Determine size required for the caller buffer */
 186
 187         required_size =
 188             acpi_ns_build_normalized_path(node, NULL, 0, no_trailing);
 189         if (!required_size) {
 190                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 191         }
 192
 193         /* Validate/Allocate/Clear caller buffer */
 194
 195         status = acpi_ut_initialize_buffer(buffer, required_size);
 196         if (ACPI_FAILURE(status)) {
 197                 return_ACPI_STATUS(status);
 198         }
 199
 200         /* Build the path in the caller buffer */
 201
 202         (void)acpi_ns_build_normalized_path(node, buffer->pointer,
 203                                             required_size, no_trailing);
 204
 205         ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "%s [%X]\n",
 206                           (char *)buffer->pointer, (u32) required_size));
 207         return_ACPI_STATUS(AE_OK);
 208 }
 209
 210 /*******************************************************************************
 211  *
 212  * FUNCTION:    acpi_ns_build_normalized_path
 213  *
 214  * PARAMETERS:  node        - Namespace node
 215  *              full_path   - Where the path name is returned
 216  *              path_size   - Size of returned path name buffer
 217  *              no_trailing - Remove trailing '_' from each name segment
 218  *
 219  * RETURN:      Return 1 if the AML path is empty, otherwise returning (length
 220  *              of pathname + 1) which means the 'FullPath' contains a trailing
 221  *              null.
 222  *
 223  * DESCRIPTION: Build and return a full namespace pathname.
 224  *              Note that if the size of 'FullPath' isn't large enough to
 225  *              contain the namespace node's path name, the actual required
 226  *              buffer length is returned, and it should be greater than
 227  *              'PathSize'. So callers are able to check the returning value
 228  *              to determine the buffer size of 'FullPath'.
 229  *
 230  ******************************************************************************/
 231
 232 u32
 233 acpi_ns_build_normalized_path(struct acpi_namespace_node *node,
 234                               char *full_path, u32 path_size, u8 no_trailing)
 235 {
 236         u32 length = 0, i;
 237         char name[ACPI_NAME_SIZE];
 238         u8 do_no_trailing;
 239         char c, *left, *right;
 240         struct acpi_namespace_node *next_node;
 241
 242         ACPI_FUNCTION_TRACE_PTR(ns_build_normalized_path, node);
 243
 244 #define ACPI_PATH_PUT8(path, size, byte, length)    \
 245         do {                                            \
 246                 if ((length) < (size))                      \
 247                 {                                           \
 248                         (path)[(length)] = (byte);              \
 249                 }                                           \
 250                 (length)++;                                 \
 251         } while (0)
 252
 253         /*
 254          * Make sure the path_size is correct, so that we don't need to
 255          * validate both full_path and path_size.
 256          */
 257         if (!full_path) {
 258                 path_size = 0;
 259         }
 260
 261         if (!node) {
 262                 goto build_trailing_null;
 263         }
 264
 265         next_node = node;
 266         while (next_node && next_node != acpi_gbl_root_node) {
 267                 if (next_node != node) {
 268                         ACPI_PATH_PUT8(full_path, path_size,
 269                                        AML_DUAL_NAME_PREFIX, length);
 270                 }
 271
 272                 ACPI_MOVE_32_TO_32(name, &next_node->name);
 273                 do_no_trailing = no_trailing;
 274                 for (i = 0; i < 4; i++) {
 275                         c = name[4 - i - 1];
 276                         if (do_no_trailing && c != '_') {
 277                                 do_no_trailing = FALSE;
 278                         }
 279                         if (!do_no_trailing) {
 280                                 ACPI_PATH_PUT8(full_path, path_size, c, length);
 281                         }
 282                 }
 283
 284                 next_node = next_node->parent;
 285         }
 286
 287         ACPI_PATH_PUT8(full_path, path_size, AML_ROOT_PREFIX, length);
 288
 289         /* Reverse the path string */
 290
 291         if (length <= path_size) {
 292                 left = full_path;
 293                 right = full_path + length - 1;
 294
 295                 while (left < right) {
 296                         c = *left;
 297                         *left++ = *right;
 298                         *right-- = c;
 299                 }
 300         }
 301
 302         /* Append the trailing null */
 303
 304 build_trailing_null:
 305         ACPI_PATH_PUT8(full_path, path_size, '\0', length);
 306
 307 #undef ACPI_PATH_PUT8
 308
 309         return_UINT32(length);
 310 }
 311
 312 /*******************************************************************************
 313  *
 314  * FUNCTION:    acpi_ns_get_normalized_pathname
 315  *
 316  * PARAMETERS:  node            - Namespace node whose pathname is needed
 317  *              no_trailing     - Remove trailing '_' from each name segment
 318  *
 319  * RETURN:      Pointer to storage containing the fully qualified name of
 320  *              the node, In external format (name segments separated by path
 321  *              separators.)
 322  *
 323  * DESCRIPTION: Used to obtain the full pathname to a namespace node, usually
 324  *              for error and debug statements. All trailing '_' will be
 325  *              removed from the full pathname if 'NoTrailing' is specified..
 326  *
 327  ******************************************************************************/
 328
 329 char *acpi_ns_get_normalized_pathname(struct acpi_namespace_node *node,
 330                                       u8 no_trailing)
 331 {
 332         char *name_buffer;
 333         acpi_size size;
 334
 335         ACPI_FUNCTION_TRACE_PTR(ns_get_normalized_pathname, node);
 336
 337         /* Calculate required buffer size based on depth below root */
 338
 339         size = acpi_ns_build_normalized_path(node, NULL, 0, no_trailing);
 340         if (!size) {
 341                 return_PTR(NULL);
 342         }
 343
 344         /* Allocate a buffer to be returned to caller */
 345
 346         name_buffer = ACPI_ALLOCATE_ZEROED(size);
 347         if (!name_buffer) {
 348                 ACPI_ERROR((AE_INFO, "Could not allocate %u bytes", (u32)size));
 349                 return_PTR(NULL);
 350         }
 351
 352         /* Build the path in the allocated buffer */
 353
 354         (void)acpi_ns_build_normalized_path(node, name_buffer, size,
 355                                             no_trailing);
 356
 357         return_PTR(name_buffer);
 358 }
 359
 360 /*******************************************************************************
 361  *
 362  * FUNCTION:    acpi_ns_build_prefixed_pathname
 363  *
 364  * PARAMETERS:  prefix_scope        - Scope/Path that prefixes the internal path
 365  *              internal_path       - Name or path of the namespace node
 366  *
 367  * RETURN:      None
 368  *
 369  * DESCRIPTION: Construct a fully qualified pathname from a concatenation of:
 370  *              1) Path associated with the prefix_scope namespace node
 371  *              2) External path representation of the Internal path
 372  *
 373  ******************************************************************************/
 374
 375 char *acpi_ns_build_prefixed_pathname(union acpi_generic_state *prefix_scope,
 376                                       const char *internal_path)
 377 {
 378         acpi_status status;
 379         char *full_path = NULL;
 380         char *external_path = NULL;
 381         char *prefix_path = NULL;
 382         u32 prefix_path_length = 0;
 383
 384         /* If there is a prefix, get the pathname to it */
 385
 386         if (prefix_scope && prefix_scope->scope.node) {
 387                 prefix_path =
 388                     acpi_ns_get_normalized_pathname(prefix_scope->scope.node,
 389                                                     TRUE);
 390                 if (prefix_path) {
 391                         prefix_path_length = strlen(prefix_path);
 392                 }
 393         }
 394
 395         status = acpi_ns_externalize_name(ACPI_UINT32_MAX, internal_path,
 396                                           NULL, &external_path);
 397         if (ACPI_FAILURE(status)) {
 398                 goto cleanup;
 399         }
 400
 401         /* Merge the prefix path and the path. 2 is for one dot and trailing null */
 402
 403         full_path =
 404             ACPI_ALLOCATE_ZEROED(prefix_path_length + strlen(external_path) +
 405                                  2);
 406         if (!full_path) {
 407                 goto cleanup;
 408         }
 409
 410         /* Don't merge if the External path is already fully qualified */
 411
 412         if (prefix_path && (*external_path != '\\') && (*external_path != '^')) {
 413                 strcat(full_path, prefix_path);
 414                 if (prefix_path[1]) {
 415                         strcat(full_path, ".");
 416                 }
 417         }
 418
 419         acpi_ns_normalize_pathname(external_path);
 420         strcat(full_path, external_path);
 421
 422 cleanup:
 423         if (prefix_path) {
 424                 ACPI_FREE(prefix_path);
 425         }
 426         if (external_path) {
 427                 ACPI_FREE(external_path);
 428         }
 429
 430         return (full_path);
 431 }
 432
 433 /*******************************************************************************
 434  *
 435  * FUNCTION:    acpi_ns_normalize_pathname
 436  *
 437  * PARAMETERS:  original_path       - Path to be normalized, in External format
 438  *
 439  * RETURN:      The original path is processed in-place
 440  *
 441  * DESCRIPTION: Remove trailing underscores from each element of a path.
 442  *
 443  *              For example:  \A___.B___.C___ becomes \A.B.C
 444  *
 445  ******************************************************************************/
 446
 447 static void acpi_ns_normalize_pathname(char *original_path)
 448 {
 449         char *input_path = original_path;
 450         char *new_path_buffer;
 451         char *new_path;
 452         u32 i;
 453
 454         /* Allocate a temp buffer in which to construct the new path */
 455
 456         new_path_buffer = ACPI_ALLOCATE_ZEROED(strlen(input_path) + 1);
 457         new_path = new_path_buffer;
 458         if (!new_path_buffer) {
 459                 return;
 460         }
 461
 462         /* Special characters may appear at the beginning of the path */
 463
 464         if (*input_path == '\\') {
 465                 *new_path = *input_path;
 466                 new_path++;
 467                 input_path++;
 468         }
 469
 470         while (*input_path == '^') {
 471                 *new_path = *input_path;
 472                 new_path++;
 473                 input_path++;
 474         }
 475
 476         /* Remainder of the path */
 477
 478         while (*input_path) {
 479
 480                 /* Do one nameseg at a time */
 481
 482                 for (i = 0; (i < ACPI_NAME_SIZE) && *input_path; i++) {
 483                         if ((i == 0) || (*input_path != '_')) { /* First char is allowed to be underscore */
 484                                 *new_path = *input_path;
 485                                 new_path++;
 486                         }
 487
 488                         input_path++;
 489                 }
 490
 491                 /* Dot means that there are more namesegs to come */
 492
 493                 if (*input_path == '.') {
 494                         *new_path = *input_path;
 495                         new_path++;
 496                         input_path++;
 497                 }
 498         }
 499
 500         *new_path = 0;
 501         strcpy(original_path, new_path_buffer);
 502         ACPI_FREE(new_path_buffer);
 503 }