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
  54 /* AML Package Length encodings */
  55
  56 #define ACPI_AML_PACKAGE_TYPE1   0x40
  57 #define ACPI_AML_PACKAGE_TYPE2   0x4000
  58 #define ACPI_AML_PACKAGE_TYPE3   0x400000
  59 #define ACPI_AML_PACKAGE_TYPE4   0x40000000
  60
  61
  62 /*******************************************************************************
  63  *
  64  * FUNCTION:    acpi_ex_allocate_name_string
  65  *
  66  * PARAMETERS:  prefix_count        - Count of parent levels. Special cases:
  67  *                                    (-1) = root,  0 = none
  68  *              num_name_segs       - count of 4-character name segments
  69  *
  70  * RETURN:      A pointer to the allocated string segment.  This segment must
  71  *              be deleted by the caller.
  72  *
  73  * DESCRIPTION: Allocate a buffer for a name string. Ensure allocated name
  74  *              string is long enough, and set up prefix if any.
  75  *
  76  ******************************************************************************/
  77
  78 char *
  79 acpi_ex_allocate_name_string (
  80         u32                             prefix_count,
  81         u32                             num_name_segs)
  82 {
  83         char                            *temp_ptr;
  84         char                            *name_string;
  85         u32                              size_needed;
  86
  87         ACPI_FUNCTION_TRACE ("ex_allocate_name_string");
  88
  89
  90         /*
  91          * Allow room for all \ and ^ prefixes, all segments, and a multi_name_prefix.
  92          * Also, one byte for the null terminator.
  93          * This may actually be somewhat longer than needed.
  94          */
  95         if (prefix_count == ACPI_UINT32_MAX) {
  96                 /* Special case for root */
  97
  98                 size_needed = 1 + (ACPI_NAME_SIZE * num_name_segs) + 2 + 1;
  99         }
 100         else {
 101                 size_needed = prefix_count + (ACPI_NAME_SIZE * num_name_segs) + 2 + 1;
 102         }
 103
 104         /*
 105          * Allocate a buffer for the name.
 106          * This buffer must be deleted by the caller!
 107          */
 108         name_string = ACPI_MEM_ALLOCATE (size_needed);
 109         if (!name_string) {
 110                 ACPI_REPORT_ERROR (("ex_allocate_name_string: Could not allocate size %d\n", size_needed));
 111                 return_PTR (NULL);
 112         }
 113
 114         temp_ptr = name_string;
 115
 116         /* Set up Root or Parent prefixes if needed */
 117
 118         if (prefix_count == ACPI_UINT32_MAX) {
 119                 *temp_ptr++ = AML_ROOT_PREFIX;
 120         }
 121         else {
 122                 while (prefix_count--) {
 123                         *temp_ptr++ = AML_PARENT_PREFIX;
 124                 }
 125         }
 126
 127
 128         /* Set up Dual or Multi prefixes if needed */
 129
 130         if (num_name_segs > 2) {
 131                 /* Set up multi prefixes   */
 132
 133                 *temp_ptr++ = AML_MULTI_NAME_PREFIX_OP;
 134                 *temp_ptr++ = (char) num_name_segs;
 135         }
 136         else if (2 == num_name_segs) {
 137                 /* Set up dual prefixes */
 138
 139                 *temp_ptr++ = AML_DUAL_NAME_PREFIX;
 140         }
 141
 142         /*
 143          * Terminate string following prefixes. acpi_ex_name_segment() will
 144          * append the segment(s)
 145          */
 146         *temp_ptr = 0;
 147
 148         return_PTR (name_string);
 149 }
 150
 151 /*******************************************************************************
 152  *
 153  * FUNCTION:    acpi_ex_name_segment
 154  *
 155  * PARAMETERS:  interpreter_mode    - Current running mode (load1/Load2/Exec)
 156  *
 157  * RETURN:      Status
 158  *
 159  * DESCRIPTION: Execute a name segment (4 bytes)
 160  *
 161  ******************************************************************************/
 162
 163 acpi_status
 164 acpi_ex_name_segment (
 165         u8                              **in_aml_address,
 166         char                            *name_string)
 167 {
 168         char                            *aml_address = (void *) *in_aml_address;
 169         acpi_status                     status = AE_OK;
 170         u32                             index;
 171         char                            char_buf[5];
 172
 173
 174         ACPI_FUNCTION_TRACE ("ex_name_segment");
 175
 176
 177         /*
 178          * If first character is a digit, then we know that we aren't looking at a
 179          * valid name segment
 180          */
 181         char_buf[0] = *aml_address;
 182
 183         if ('0' <= char_buf[0] && char_buf[0] <= '9') {
 184                 ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "leading digit: %c\n", char_buf[0]));
 185                 return_ACPI_STATUS (AE_CTRL_PENDING);
 186         }
 187
 188         ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "Bytes from stream:\n"));
 189
 190         for (index = 0;
 191                 (index < ACPI_NAME_SIZE) && (acpi_ut_valid_acpi_character (*aml_address));
 192                 index++) {
 193                 char_buf[index] = *aml_address++;
 194                 ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "%c\n", char_buf[index]));
 195         }
 196
 197
 198         /* Valid name segment  */
 199
 200         if (index == 4) {
 201                 /* Found 4 valid characters */
 202
 203                 char_buf[4] = '\0';
 204
 205                 if (name_string) {
 206                         ACPI_STRCAT (name_string, char_buf);
 207                         ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
 208                                 "Appended to - %s \n", name_string));
 209                 }
 210                 else {
 211                         ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
 212                                 "No Name string - %s \n", char_buf));
 213                 }
 214         }
 215         else if (index == 0) {
 216                 /*
 217                  * First character was not a valid name character,
 218                  * so we are looking at something other than a name.
 219                  */
 220                 ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
 221                         "Leading character is not alpha: %02Xh (not a name)\n",
 222                         char_buf[0]));
 223                 status = AE_CTRL_PENDING;
 224         }
 225         else {
 226                 /* Segment started with one or more valid characters, but fewer than 4 */
 227
 228                 status = AE_AML_BAD_NAME;
 229                 ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Bad character %02x in name, at %p\n",
 230                         *aml_address, aml_address));
 231         }
 232
 233         *in_aml_address = (u8 *) aml_address;
 234         return_ACPI_STATUS (status);
 235 }
 236
 237
 238 /*******************************************************************************
 239  *
 240  * FUNCTION:    acpi_ex_get_name_string
 241  *
 242  * PARAMETERS:  data_type           - Data type to be associated with this name
 243  *
 244  * RETURN:      Status
 245  *
 246  * DESCRIPTION: Get a name, including any prefixes.
 247  *
 248  ******************************************************************************/
 249
 250 acpi_status
 251 acpi_ex_get_name_string (
 252         acpi_object_type                data_type,
 253         u8                              *in_aml_address,
 254         char                            **out_name_string,
 255         u32                             *out_name_length)
 256 {
 257         acpi_status                     status = AE_OK;
 258         u8                              *aml_address = in_aml_address;
 259         char                            *name_string = NULL;
 260         u32                             num_segments;
 261         u32                             prefix_count = 0;
 262         u8                              has_prefix = FALSE;
 263
 264
 265         ACPI_FUNCTION_TRACE_PTR ("ex_get_name_string", aml_address);
 266
 267
 268         if (ACPI_TYPE_LOCAL_REGION_FIELD == data_type  ||
 269                 ACPI_TYPE_LOCAL_BANK_FIELD == data_type    ||
 270                 ACPI_TYPE_LOCAL_INDEX_FIELD == data_type) {
 271                 /* Disallow prefixes for types associated with field_unit names */
 272
 273                 name_string = acpi_ex_allocate_name_string (0, 1);
 274                 if (!name_string) {
 275                         status = AE_NO_MEMORY;
 276                 }
 277                 else {
 278                         status = acpi_ex_name_segment (&aml_address, name_string);
 279                 }
 280         }
 281         else {
 282                 /*
 283                  * data_type is not a field name.
 284                  * Examine first character of name for root or parent prefix operators
 285                  */
 286                 switch (*aml_address) {
 287                 case AML_ROOT_PREFIX:
 288
 289                         ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "root_prefix(\\) at %p\n", aml_address));
 290
 291                         /*
 292                          * Remember that we have a root_prefix --
 293                          * see comment in acpi_ex_allocate_name_string()
 294                          */
 295                         aml_address++;
 296                         prefix_count = ACPI_UINT32_MAX;
 297                         has_prefix = TRUE;
 298                         break;
 299
 300
 301                 case AML_PARENT_PREFIX:
 302
 303                         /* Increment past possibly multiple parent prefixes */
 304
 305                         do {
 306                                 ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "parent_prefix (^) at %p\n", aml_address));
 307
 308                                 aml_address++;
 309                                 prefix_count++;
 310
 311                         } while (*aml_address == AML_PARENT_PREFIX);
 312
 313                         has_prefix = TRUE;
 314                         break;
 315
 316
 317                 default:
 318
 319                         /* Not a prefix character */
 320
 321                         break;
 322                 }
 323
 324
 325                 /* Examine first character of name for name segment prefix operator */
 326
 327                 switch (*aml_address) {
 328                 case AML_DUAL_NAME_PREFIX:
 329
 330                         ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "dual_name_prefix at %p\n", aml_address));
 331
 332                         aml_address++;
 333                         name_string = acpi_ex_allocate_name_string (prefix_count, 2);
 334                         if (!name_string) {
 335                                 status = AE_NO_MEMORY;
 336                                 break;
 337                         }
 338
 339                         /* Indicate that we processed a prefix */
 340
 341                         has_prefix = TRUE;
 342
 343                         status = acpi_ex_name_segment (&aml_address, name_string);
 344                         if (ACPI_SUCCESS (status)) {
 345                                 status = acpi_ex_name_segment (&aml_address, name_string);
 346                         }
 347                         break;
 348
 349
 350                 case AML_MULTI_NAME_PREFIX_OP:
 351
 352                         ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "multi_name_prefix at %p\n", aml_address));
 353
 354                         /* Fetch count of segments remaining in name path */
 355
 356                         aml_address++;
 357                         num_segments = *aml_address;
 358
 359                         name_string = acpi_ex_allocate_name_string (prefix_count, num_segments);
 360                         if (!name_string) {
 361                                 status = AE_NO_MEMORY;
 362                                 break;
 363                         }
 364
 365                         /* Indicate that we processed a prefix */
 366
 367                         aml_address++;
 368                         has_prefix = TRUE;
 369
 370                         while (num_segments &&
 371                                         (status = acpi_ex_name_segment (&aml_address, name_string)) == AE_OK) {
 372                                 num_segments--;
 373                         }
 374
 375                         break;
 376
 377
 378                 case 0:
 379
 380                         /* null_name valid as of 8-12-98 ASL/AML Grammar Update */
 381
 382                         if (prefix_count == ACPI_UINT32_MAX) {
 383                                 ACPI_DEBUG_PRINT ((ACPI_DB_EXEC, "name_seg is \"\\\" followed by NULL\n"));
 384                         }
 385
 386                         /* Consume the NULL byte */
 387
 388                         aml_address++;
 389                         name_string = acpi_ex_allocate_name_string (prefix_count, 0);
 390                         if (!name_string) {
 391                                 status = AE_NO_MEMORY;
 392                                 break;
 393                         }
 394
 395                         break;
 396
 397
 398                 default:
 399
 400                         /* Name segment string */
 401
 402                         name_string = acpi_ex_allocate_name_string (prefix_count, 1);
 403                         if (!name_string) {
 404                                 status = AE_NO_MEMORY;
 405                                 break;
 406                         }
 407
 408                         status = acpi_ex_name_segment (&aml_address, name_string);
 409                         break;
 410                 }
 411         }
 412
 413         if (AE_CTRL_PENDING == status && has_prefix) {
 414                 /* Ran out of segments after processing a prefix */
 415
 416                 ACPI_REPORT_ERROR (
 417                         ("ex_do_name: Malformed Name at %p\n", name_string));
 418                 status = AE_AML_BAD_NAME;
 419         }
 420
 421         *out_name_string = name_string;
 422         *out_name_length = (u32) (aml_address - in_aml_address);
 423
 424         return_ACPI_STATUS (status);
 425 }
 426
 427