drivers/acpi/executer/exnames.c

   1
   2 /******************************************************************************
   3  *
   4  * Module Name: exnames - interpreter/scanner name load/execute
   5  *
   6  *****************************************************************************/
   7
   8 /*
   9  * Copyright (C) 2000 - 2005, R. Byron Moore
  10  * All rights reserved.
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions
  14  * are met:
  15  * 1. Redistributions of source code must retain the above copyright
  16  *    notice, this list of conditions, and the following disclaimer,
  17  *    without modification.
  18  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
  19  *    substantially similar to the "NO WARRANTY" disclaimer below
  20  *    ("Disclaimer") and any redistribution must be conditioned upon
  21  *    including a substantially similar Disclaimer requirement for further
  22  *    binary redistribution.
  23  * 3. Neither the names of the above-listed copyright holders nor the names
  24  *    of any contributors may be used to endorse or promote products derived
  25  *    from this software without specific prior written permission.
  26  *
  27  * Alternatively, this software may be distributed under the terms of the
  28  * GNU General Public License ("GPL") version 2 as published by the Free
  29  * Software Foundation.
  30  *
  31  * NO WARRANTY
  32  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  33  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  34  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
  35  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  36  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  37  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  38  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  39  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  40  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  41  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  42  * POSSIBILITY OF SUCH DAMAGES.
  43  */
  44
  45
  46 #include <acpi/acpi.h>
  47 #include <acpi/acinterp.h>
  48 #include <acpi/amlcode.h>
  49
  50 #define _COMPONENT          ACPI_EXECUTER
  51          ACPI_MODULE_NAME    ("exnames")
  52
  53 /* Local prototypes */
  54
  55 static char *
  56 acpi_ex_allocate_name_string (
  57         u32                             prefix_count,
  58         u32                             num_name_segs);
  59
  60 static acpi_status
  61 acpi_ex_name_segment (
  62         u8                              **in_aml_address,
  63         char                            *name_string);
  64
  65
  66 /*******************************************************************************
  67  *
  68  * FUNCTION:    acpi_ex_allocate_name_string
  69  *
  70  * PARAMETERS:  prefix_count        - Count of parent levels. Special cases:
  71  *                                    (-1)==root,  0==none
  72  *              num_name_segs       - count of 4-character name segments
  73  *
  74  * RETURN:      A pointer to the allocated string segment.  This segment must
  75  *              be deleted by the caller.
  76  *
  77  * DESCRIPTION: Allocate a buffer for a name string. Ensure allocated name
  78  *              string is long enough, and set up prefix if any.
  79  *
  80  ******************************************************************************/
  81
  82 static char *
  83 acpi_ex_allocate_name_string (
  84         u32                             prefix_count,
  85         u32                             num_name_segs)
  86 {
  87         char                            *temp_ptr;
  88         char                            *name_string;
  89         u32                              size_needed;
  90
  91         ACPI_FUNCTION_TRACE ("ex_allocate_name_string");
  92
  93
  94         /*
  95          * Allow room for all \ and ^ prefixes, all segments and a multi_name_prefix.
  96          * Also, one byte for the null terminator.
  97          * This may actually be somewhat longer than needed.
  98          */
  99         if (prefix_count == ACPI_UINT32_MAX) {
 100                 /* Special case for root */
 101
 102                 size_needed = 1 + (ACPI_NAME_SIZE * num_name_segs) + 2 + 1;
 103         }
 104         else {
 105                 size_needed = prefix_count + (ACPI_NAME_SIZE * num_name_segs) + 2 + 1;
 106         }
 107
 108         /*
 109          * Allocate a buffer for the name.
 110          * This buffer must be deleted by the caller!
 111          */
 112         name_string = ACPI_MEM_ALLOCATE (size_needed);
 113         if (!name_string) {
 114                 ACPI_REPORT_ERROR ((
 115                         "ex_allocate_name_string: Could not allocate size %d\n", size_needed));
 116                 return_PTR (NULL);
 117         }
 118
 119         temp_ptr = name_string;
 120
 121         /* Set up Root or Parent prefixes if needed */
 122
 123         if (prefix_count == ACPI_UINT32_MAX) {
 124                 *temp_ptr++ = AML_ROOT_PREFIX;
 125         }
 126         else {
 127                 while (prefix_count--) {
 128                         *temp_ptr++ = AML_PARENT_PREFIX;
 129                 }
 130         }
 131
 132
 133         /* Set up Dual or Multi prefixes if needed */
 134
 135         if (num_name_segs > 2) {
 136                 /* Set up multi prefixes   */
 137
 138                 *temp_ptr++ = AML_MULTI_NAME_PREFIX_OP;
 139                 *temp_ptr++ = (char) num_name_segs;
 140         }
 141         else if (2 == num_name_segs) {
 142                 /* Set up dual prefixes */
 143
 144                 *temp_ptr++ = AML_DUAL_NAME_PREFIX;
 145         }
 146
 147         /*
 148          * Terminate string following prefixes. acpi_ex_name_segment() will
 149          * append the segment(s)
 150          */
 151         *temp_ptr = 0;
 152
 153         return_PTR (name_string);
 154 }
 155
 156 /*******************************************************************************
 157  *
 158  * FUNCTION:    acpi_ex_name_segment
 159  *
 160  * PARAMETERS:  in_aml_address  - Pointer to the name in the AML code
 161  *              name_string     - Where to return the name. The name is appended
 162  *                                to any existing string to form a namepath
 163  *
 164  * RETURN:      Status
 165  *
 166  * DESCRIPTION: Extract an ACPI name (4 bytes) from the AML byte stream
 167  *
 168  ******************************************************************************/
 169
 170 static acpi_status
 171 acpi_ex_name_segment (
 172         u8                              **in_aml_address,
 173         char                            *name_string)
 174 {
 175         char                            *aml_address = (void *) *in_aml_address;
 176         acpi_status                     status = AE_OK;
 177         u32                             index;
 178         char                            char_buf[5];
 179
 180
 181         ACPI_FUNCTION_TRACE ("ex_name_segment");
 182
 183
 184         /*
 185          * If first character is a digit, then we know that we aren't looking at a
 186          * valid name segment
 187          */
 188         char_buf[0] = *aml_address;
 189
 190         if ('0' <= char_buf[0] && char_buf[0] <= '9') {
 191                 ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "leading digit: %c\n", char_buf[0]));
 192                 return_ACPI_STATUS (AE_CTRL_PENDING);
 193         }
 194
 195         ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "Bytes from stream:\n"));
 196
 197         for (index = 0;
 198                 (index < ACPI_NAME_SIZE) && (acpi_ut_valid_acpi_character (*aml_address));
 199                 index++) {
 200                 char_buf[index] = *aml_address++;
 201                 ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "%c\n", char_buf[index]));
 202         }
 203
 204
 205         /* Valid name segment  */
 206
 207         if (index == 4) {
 208                 /* Found 4 valid characters */
 209
 210                 char_buf[4] = '\0';
 211
 212                 if (name_string) {
 213                         ACPI_STRCAT (name_string, char_buf);
 214                         ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
 215                                 "Appended to - %s \n", name_string));
 216                 }
 217                 else {
 218                         ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
 219                                 "No Name string - %s \n", char_buf));
 220                 }
 221         }
 222         else if (index == 0) {
 223                 /*
 224                  * First character was not a valid name character,
 225                  * so we are looking at something other than a name.
 226                  */
 227                 ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
 228                         "Leading character is not alpha: %02Xh (not a name)\n",
 229                         char_buf[0]));
 230                 status = AE_CTRL_PENDING;
 231         }
 232         else {
 233                 /*
 234                  * Segment started with one or more valid characters, but fewer than
 235                  * the required 4
 236                  */
 237                 status = AE_AML_BAD_NAME;
 238                 ACPI_DEBUG_PRINT ((ACPI_DB_ERROR,
 239                         "Bad character %02x in name, at %p\n",
 240                         *aml_address, aml_address));
 241         }
 242
 243         *in_aml_address = (u8 *) aml_address;
 244         return_ACPI_STATUS (status);
 245 }
 246
 247
 248 /*******************************************************************************
 249  *
 250  * FUNCTION:    acpi_ex_get_name_string
 251  *
 252  * PARAMETERS:  data_type           - Object type to be associated with this
 253  *                                    name
 254  *              in_aml_address      - Pointer to the namestring in the AML code
 255  *              out_name_string     - Where the namestring is returned
 256  *              out_name_length     - Length of the returned string
 257  *
 258  * RETURN:      Status, namestring and length
 259  *
 260  * DESCRIPTION: Extract a full namepath from the AML byte stream,
 261  *              including any prefixes.
 262  *
 263  ******************************************************************************/
 264
 265 acpi_status
 266 acpi_ex_get_name_string (
 267         acpi_object_type                data_type,
 268         u8                              *in_aml_address,
 269         char                            **out_name_string,
 270         u32                             *out_name_length)
 271 {
 272         acpi_status                     status = AE_OK;
 273         u8                              *aml_address = in_aml_address;
 274         char                            *name_string = NULL;
 275         u32                             num_segments;
 276         u32                             prefix_count = 0;
 277         u8                              has_prefix = FALSE;
 278
 279
 280         ACPI_FUNCTION_TRACE_PTR ("ex_get_name_string", aml_address);
 281
 282
 283         if (ACPI_TYPE_LOCAL_REGION_FIELD == data_type  ||
 284                 ACPI_TYPE_LOCAL_BANK_FIELD == data_type    ||
 285                 ACPI_TYPE_LOCAL_INDEX_FIELD == data_type) {
 286                 /* Disallow prefixes for types associated with field_unit names */
 287
 288                 name_string = acpi_ex_allocate_name_string (0, 1);
 289                 if (!name_string) {
 290                         status = AE_NO_MEMORY;
 291                 }
 292                 else {
 293                         status = acpi_ex_name_segment (&aml_address, name_string);
 294                 }
 295         }
 296         else {
 297                 /*
 298                  * data_type is not a field name.
 299                  * Examine first character of name for root or parent prefix operators
 300                  */
 301                 switch (*aml_address) {
 302                 case AML_ROOT_PREFIX:
 303
 304                         ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "root_prefix(\\) at %p\n",
 305                                 aml_address));
 306
 307                         /*
 308                          * Remember that we have a root_prefix --
 309                          * see comment in acpi_ex_allocate_name_string()
 310                          */
 311                         aml_address++;
 312                         prefix_count = ACPI_UINT32_MAX;
 313                         has_prefix = TRUE;
 314                         break;
 315
 316
 317                 case AML_PARENT_PREFIX:
 318
 319                         /* Increment past possibly multiple parent prefixes */
 320
 321                         do {
 322                                 ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "parent_prefix (^) at %p\n",
 323                                         aml_address));
 324
 325                                 aml_address++;
 326                                 prefix_count++;
 327
 328                         } while (*aml_address == AML_PARENT_PREFIX);
 329
 330                         has_prefix = TRUE;
 331                         break;
 332
 333
 334                 default:
 335
 336                         /* Not a prefix character */
 337
 338                         break;
 339                 }
 340
 341                 /* Examine first character of name for name segment prefix operator */
 342
 343                 switch (*aml_address) {
 344                 case AML_DUAL_NAME_PREFIX:
 345
 346                         ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "dual_name_prefix at %p\n",
 347                                 aml_address));
 348
 349                         aml_address++;
 350                         name_string = acpi_ex_allocate_name_string (prefix_count, 2);
 351                         if (!name_string) {
 352                                 status = AE_NO_MEMORY;
 353                                 break;
 354                         }
 355
 356                         /* Indicate that we processed a prefix */
 357
 358                         has_prefix = TRUE;
 359
 360                         status = acpi_ex_name_segment (&aml_address, name_string);
 361                         if (ACPI_SUCCESS (status)) {
 362                                 status = acpi_ex_name_segment (&aml_address, name_string);
 363                         }
 364                         break;
 365
 366
 367                 case AML_MULTI_NAME_PREFIX_OP:
 368
 369                         ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "multi_name_prefix at %p\n",
 370                                 aml_address));
 371
 372                         /* Fetch count of segments remaining in name path */
 373
 374                         aml_address++;
 375                         num_segments = *aml_address;
 376
 377                         name_string = acpi_ex_allocate_name_string (prefix_count, num_segments);
 378                         if (!name_string) {
 379                                 status = AE_NO_MEMORY;
 380                                 break;
 381                         }
 382
 383                         /* Indicate that we processed a prefix */
 384
 385                         aml_address++;
 386                         has_prefix = TRUE;
 387
 388                         while (num_segments &&
 389                                         (status = acpi_ex_name_segment (&aml_address, name_string)) ==
 390                                                 AE_OK) {
 391                                 num_segments--;
 392                         }
 393
 394                         break;
 395
 396
 397                 case 0:
 398
 399                         /* null_name valid as of 8-12-98 ASL/AML Grammar Update */
 400
 401                         if (prefix_count == ACPI_UINT32_MAX) {
 402                                 ACPI_DEBUG_PRINT ((ACPI_DB_EXEC,
 403                                         "name_seg is \"\\\" followed by NULL\n"));
 404                         }
 405
 406                         /* Consume the NULL byte */
 407
 408                         aml_address++;
 409                         name_string = acpi_ex_allocate_name_string (prefix_count, 0);
 410                         if (!name_string) {
 411                                 status = AE_NO_MEMORY;
 412                                 break;
 413                         }
 414
 415                         break;
 416
 417
 418                 default:
 419
 420                         /* Name segment string */
 421
 422                         name_string = acpi_ex_allocate_name_string (prefix_count, 1);
 423                         if (!name_string) {
 424                                 status = AE_NO_MEMORY;
 425                                 break;
 426                         }
 427
 428                         status = acpi_ex_name_segment (&aml_address, name_string);
 429                         break;
 430                 }
 431         }
 432
 433         if (AE_CTRL_PENDING == status && has_prefix) {
 434                 /* Ran out of segments after processing a prefix */
 435
 436                 ACPI_REPORT_ERROR (
 437                         ("ex_do_name: Malformed Name at %p\n", name_string));
 438                 status = AE_AML_BAD_NAME;
 439         }
 440
 441         *out_name_string = name_string;
 442         *out_name_length = (u32) (aml_address - in_aml_address);
 443
 444         return_ACPI_STATUS (status);
 445 }
 446
 447