drivers/acpi/tables/tbxface.c

   1 /******************************************************************************
   2  *
   3  * Module Name: tbxface - Public interfaces to the ACPI subsystem
   4  *                         ACPI table oriented interfaces
   5  *
   6  *****************************************************************************/
   7
   8 /*
   9  * Copyright (C) 2000 - 2007, 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 #include <acpi/acpi.h>
  46 #include <acpi/acnamesp.h>
  47 #include <acpi/actables.h>
  48
  49 #define _COMPONENT          ACPI_TABLES
  50 ACPI_MODULE_NAME("tbxface")
  51
  52 /* Local prototypes */
  53 static acpi_status acpi_tb_load_namespace(void);
  54
  55 static int no_auto_ssdt;
  56
  57 /*******************************************************************************
  58  *
  59  * FUNCTION:    acpi_allocate_root_table
  60  *
  61  * PARAMETERS:  initial_table_count - Size of initial_table_array, in number of
  62  *                                    struct acpi_table_desc structures
  63  *
  64  * RETURN:      Status
  65  *
  66  * DESCRIPTION: Allocate a root table array. Used by i_aSL compiler and
  67  *              acpi_initialize_tables.
  68  *
  69  ******************************************************************************/
  70
  71 acpi_status acpi_allocate_root_table(u32 initial_table_count)
  72 {
  73
  74         acpi_gbl_root_table_list.size = initial_table_count;
  75         acpi_gbl_root_table_list.flags = ACPI_ROOT_ALLOW_RESIZE;
  76
  77         return (acpi_tb_resize_root_table_list());
  78 }
  79
  80 /*******************************************************************************
  81  *
  82  * FUNCTION:    acpi_initialize_tables
  83  *
  84  * PARAMETERS:  initial_table_array - Pointer to an array of pre-allocated
  85  *                                    struct acpi_table_desc structures. If NULL, the
  86  *                                    array is dynamically allocated.
  87  *              initial_table_count - Size of initial_table_array, in number of
  88  *                                    struct acpi_table_desc structures
  89  *              allow_realloc       - Flag to tell Table Manager if resize of
  90  *                                    pre-allocated array is allowed. Ignored
  91  *                                    if initial_table_array is NULL.
  92  *
  93  * RETURN:      Status
  94  *
  95  * DESCRIPTION: Initialize the table manager, get the RSDP and RSDT/XSDT.
  96  *
  97  * NOTE:        Allows static allocation of the initial table array in order
  98  *              to avoid the use of dynamic memory in confined environments
  99  *              such as the kernel boot sequence where it may not be available.
 100  *
 101  *              If the host OS memory managers are initialized, use NULL for
 102  *              initial_table_array, and the table will be dynamically allocated.
 103  *
 104  ******************************************************************************/
 105
 106 acpi_status __init
 107 acpi_initialize_tables(struct acpi_table_desc * initial_table_array,
 108                        u32 initial_table_count, u8 allow_resize)
 109 {
 110         acpi_physical_address rsdp_address;
 111         acpi_status status;
 112
 113         ACPI_FUNCTION_TRACE(acpi_initialize_tables);
 114
 115         /*
 116          * Set up the Root Table Array
 117          * Allocate the table array if requested
 118          */
 119         if (!initial_table_array) {
 120                 status = acpi_allocate_root_table(initial_table_count);
 121                 if (ACPI_FAILURE(status)) {
 122                         return_ACPI_STATUS(status);
 123                 }
 124         } else {
 125                 /* Root Table Array has been statically allocated by the host */
 126
 127                 ACPI_MEMSET(initial_table_array, 0,
 128                             initial_table_count *
 129                             sizeof(struct acpi_table_desc));
 130
 131                 acpi_gbl_root_table_list.tables = initial_table_array;
 132                 acpi_gbl_root_table_list.size = initial_table_count;
 133                 acpi_gbl_root_table_list.flags = ACPI_ROOT_ORIGIN_UNKNOWN;
 134                 if (allow_resize) {
 135                         acpi_gbl_root_table_list.flags |=
 136                             ACPI_ROOT_ALLOW_RESIZE;
 137                 }
 138         }
 139
 140         /* Get the address of the RSDP */
 141
 142         rsdp_address = acpi_os_get_root_pointer();
 143         if (!rsdp_address) {
 144                 return_ACPI_STATUS(AE_NOT_FOUND);
 145         }
 146
 147         /*
 148          * Get the root table (RSDT or XSDT) and extract all entries to the local
 149          * Root Table Array. This array contains the information of the RSDT/XSDT
 150          * in a common, more useable format.
 151          */
 152         status =
 153             acpi_tb_parse_root_table(rsdp_address, ACPI_TABLE_ORIGIN_MAPPED);
 154         return_ACPI_STATUS(status);
 155 }
 156
 157 /*******************************************************************************
 158  *
 159  * FUNCTION:    acpi_reallocate_root_table
 160  *
 161  * PARAMETERS:  None
 162  *
 163  * RETURN:      Status
 164  *
 165  * DESCRIPTION: Reallocate Root Table List into dynamic memory. Copies the
 166  *              root list from the previously provided scratch area. Should
 167  *              be called once dynamic memory allocation is available in the
 168  *              kernel
 169  *
 170  ******************************************************************************/
 171 acpi_status acpi_reallocate_root_table(void)
 172 {
 173         struct acpi_table_desc *tables;
 174         acpi_size new_size;
 175
 176         ACPI_FUNCTION_TRACE(acpi_reallocate_root_table);
 177
 178         /*
 179          * Only reallocate the root table if the host provided a static buffer
 180          * for the table array in the call to acpi_initialize_tables.
 181          */
 182         if (acpi_gbl_root_table_list.flags & ACPI_ROOT_ORIGIN_ALLOCATED) {
 183                 return_ACPI_STATUS(AE_SUPPORT);
 184         }
 185
 186         new_size =
 187             (acpi_gbl_root_table_list.count +
 188              ACPI_ROOT_TABLE_SIZE_INCREMENT) * sizeof(struct acpi_table_desc);
 189
 190         /* Create new array and copy the old array */
 191
 192         tables = ACPI_ALLOCATE_ZEROED(new_size);
 193         if (!tables) {
 194                 return_ACPI_STATUS(AE_NO_MEMORY);
 195         }
 196
 197         ACPI_MEMCPY(tables, acpi_gbl_root_table_list.tables, new_size);
 198
 199         acpi_gbl_root_table_list.size = acpi_gbl_root_table_list.count;
 200         acpi_gbl_root_table_list.tables = tables;
 201         acpi_gbl_root_table_list.flags =
 202             ACPI_ROOT_ORIGIN_ALLOCATED | ACPI_ROOT_ALLOW_RESIZE;
 203
 204         return_ACPI_STATUS(AE_OK);
 205 }
 206
 207 /*******************************************************************************
 208  *
 209  * FUNCTION:    acpi_load_table
 210  *
 211  * PARAMETERS:  table_ptr       - pointer to a buffer containing the entire
 212  *                                table to be loaded
 213  *
 214  * RETURN:      Status
 215  *
 216  * DESCRIPTION: This function is called to load a table from the caller's
 217  *              buffer. The buffer must contain an entire ACPI Table including
 218  *              a valid header. The header fields will be verified, and if it
 219  *              is determined that the table is invalid, the call will fail.
 220  *
 221  ******************************************************************************/
 222 acpi_status acpi_load_table(struct acpi_table_header *table_ptr)
 223 {
 224         acpi_status status;
 225         acpi_native_uint table_index;
 226         struct acpi_table_desc table_desc;
 227
 228         if (!table_ptr)
 229                 return AE_BAD_PARAMETER;
 230
 231         ACPI_MEMSET(&table_desc, 0, sizeof(struct acpi_table_desc));
 232         table_desc.pointer = table_ptr;
 233         table_desc.length = table_ptr->length;
 234         table_desc.flags = ACPI_TABLE_ORIGIN_UNKNOWN;
 235
 236         /*
 237          * Install the new table into the local data structures
 238          */
 239         status = acpi_tb_add_table(&table_desc, &table_index);
 240         if (ACPI_FAILURE(status)) {
 241                 return status;
 242         }
 243         status = acpi_ns_load_table(table_index, acpi_gbl_root_node);
 244         return status;
 245 }
 246
 247 ACPI_EXPORT_SYMBOL(acpi_load_table)
 248
 249 /******************************************************************************
 250  *
 251  * FUNCTION:    acpi_get_table_header
 252  *
 253  * PARAMETERS:  Signature           - ACPI signature of needed table
 254  *              Instance            - Which instance (for SSDTs)
 255  *              out_table_header    - The pointer to the table header to fill
 256  *
 257  * RETURN:      Status and pointer to mapped table header
 258  *
 259  * DESCRIPTION: Finds an ACPI table header.
 260  *
 261  * NOTE:        Caller is responsible in unmapping the header with
 262  *              acpi_os_unmap_memory
 263  *
 264  *****************************************************************************/
 265 acpi_status
 266 acpi_get_table_header(char *signature,
 267                       acpi_native_uint instance,
 268                       struct acpi_table_header * out_table_header)
 269 {
 270         acpi_native_uint i;
 271         acpi_native_uint j;
 272         struct acpi_table_header *header;
 273
 274         /* Parameter validation */
 275
 276         if (!signature || !out_table_header) {
 277                 return (AE_BAD_PARAMETER);
 278         }
 279
 280         /*
 281          * Walk the root table list
 282          */
 283         for (i = 0, j = 0; i < acpi_gbl_root_table_list.count; i++) {
 284                 if (!ACPI_COMPARE_NAME
 285                     (&(acpi_gbl_root_table_list.tables[i].signature),
 286                      signature)) {
 287                         continue;
 288                 }
 289
 290                 if (++j < instance) {
 291                         continue;
 292                 }
 293
 294                 if (!acpi_gbl_root_table_list.tables[i].pointer) {
 295                         if ((acpi_gbl_root_table_list.tables[i].
 296                              flags & ACPI_TABLE_ORIGIN_MASK) ==
 297                             ACPI_TABLE_ORIGIN_MAPPED) {
 298                                 header =
 299                                     acpi_os_map_memory(acpi_gbl_root_table_list.
 300                                                        tables[i].address,
 301                                                        sizeof(struct
 302                                                               acpi_table_header));
 303                                 if (!header) {
 304                                         return AE_NO_MEMORY;
 305                                 }
 306                                 ACPI_MEMCPY(out_table_header, header,
 307                                             sizeof(struct acpi_table_header));
 308                                 acpi_os_unmap_memory(header,
 309                                                      sizeof(struct
 310                                                             acpi_table_header));
 311                         } else {
 312                                 return AE_NOT_FOUND;
 313                         }
 314                 } else {
 315                         ACPI_MEMCPY(out_table_header,
 316                                     acpi_gbl_root_table_list.tables[i].pointer,
 317                                     sizeof(struct acpi_table_header));
 318                 }
 319                 return (AE_OK);
 320         }
 321
 322         return (AE_NOT_FOUND);
 323 }
 324
 325 ACPI_EXPORT_SYMBOL(acpi_get_table_header)
 326
 327 /******************************************************************************
 328  *
 329  * FUNCTION:    acpi_unload_table_id
 330  *
 331  * PARAMETERS:  id            - Owner ID of the table to be removed.
 332  *
 333  * RETURN:      Status
 334  *
 335  * DESCRIPTION: This routine is used to force the unload of a table (by id)
 336  *
 337  ******************************************************************************/
 338 acpi_status acpi_unload_table_id(acpi_owner_id id)
 339 {
 340         int i;
 341         acpi_status status = AE_NOT_EXIST;
 342
 343         ACPI_FUNCTION_TRACE(acpi_unload_table_id);
 344
 345         /* Find table in the global table list */
 346         for (i = 0; i < acpi_gbl_root_table_list.count; ++i) {
 347                 if (id != acpi_gbl_root_table_list.tables[i].owner_id) {
 348                         continue;
 349                 }
 350                 /*
 351                  * Delete all namespace objects owned by this table. Note that these
 352                  * objects can appear anywhere in the namespace by virtue of the AML
 353                  * "Scope" operator. Thus, we need to track ownership by an ID, not
 354                  * simply a position within the hierarchy
 355                  */
 356                 acpi_tb_delete_namespace_by_owner(i);
 357                 status = acpi_tb_release_owner_id(i);
 358                 acpi_tb_set_table_loaded_flag(i, FALSE);
 359                 break;
 360         }
 361         return_ACPI_STATUS(status);
 362 }
 363
 364 ACPI_EXPORT_SYMBOL(acpi_unload_table_id)
 365
 366 /*******************************************************************************
 367  *
 368  * FUNCTION:    acpi_get_table
 369  *
 370  * PARAMETERS:  Signature           - ACPI signature of needed table
 371  *              Instance            - Which instance (for SSDTs)
 372  *              out_table           - Where the pointer to the table is returned
 373  *
 374  * RETURN:      Status and pointer to table
 375  *
 376  * DESCRIPTION: Finds and verifies an ACPI table.
 377  *
 378  *****************************************************************************/
 379 acpi_status
 380 acpi_get_table(char *signature,
 381                acpi_native_uint instance, struct acpi_table_header **out_table)
 382 {
 383         acpi_native_uint i;
 384         acpi_native_uint j;
 385         acpi_status status;
 386
 387         /* Parameter validation */
 388
 389         if (!signature || !out_table) {
 390                 return (AE_BAD_PARAMETER);
 391         }
 392
 393         /*
 394          * Walk the root table list
 395          */
 396         for (i = 0, j = 0; i < acpi_gbl_root_table_list.count; i++) {
 397                 if (!ACPI_COMPARE_NAME
 398                     (&(acpi_gbl_root_table_list.tables[i].signature),
 399                      signature)) {
 400                         continue;
 401                 }
 402
 403                 if (++j < instance) {
 404                         continue;
 405                 }
 406
 407                 status =
 408                     acpi_tb_verify_table(&acpi_gbl_root_table_list.tables[i]);
 409                 if (ACPI_SUCCESS(status)) {
 410                         *out_table = acpi_gbl_root_table_list.tables[i].pointer;
 411                 }
 412
 413                 if (!acpi_gbl_permanent_mmap) {
 414                         acpi_gbl_root_table_list.tables[i].pointer = NULL;
 415                 }
 416
 417                 return (status);
 418         }
 419
 420         return (AE_NOT_FOUND);
 421 }
 422
 423 ACPI_EXPORT_SYMBOL(acpi_get_table)
 424
 425 /*******************************************************************************
 426  *
 427  * FUNCTION:    acpi_get_table_by_index
 428  *
 429  * PARAMETERS:  table_index         - Table index
 430  *              Table               - Where the pointer to the table is returned
 431  *
 432  * RETURN:      Status and pointer to the table
 433  *
 434  * DESCRIPTION: Obtain a table by an index into the global table list.
 435  *
 436  ******************************************************************************/
 437 acpi_status
 438 acpi_get_table_by_index(acpi_native_uint table_index,
 439                         struct acpi_table_header ** table)
 440 {
 441         acpi_status status;
 442
 443         ACPI_FUNCTION_TRACE(acpi_get_table_by_index);
 444
 445         /* Parameter validation */
 446
 447         if (!table) {
 448                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 449         }
 450
 451         (void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
 452
 453         /* Validate index */
 454
 455         if (table_index >= acpi_gbl_root_table_list.count) {
 456                 (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
 457                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 458         }
 459
 460         if (!acpi_gbl_root_table_list.tables[table_index].pointer) {
 461
 462                 /* Table is not mapped, map it */
 463
 464                 status =
 465                     acpi_tb_verify_table(&acpi_gbl_root_table_list.
 466                                          tables[table_index]);
 467                 if (ACPI_FAILURE(status)) {
 468                         (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
 469                         return_ACPI_STATUS(status);
 470                 }
 471         }
 472
 473         *table = acpi_gbl_root_table_list.tables[table_index].pointer;
 474         (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
 475         return_ACPI_STATUS(AE_OK);
 476 }
 477
 478 ACPI_EXPORT_SYMBOL(acpi_get_table_by_index)
 479
 480 /*******************************************************************************
 481  *
 482  * FUNCTION:    acpi_tb_load_namespace
 483  *
 484  * PARAMETERS:  None
 485  *
 486  * RETURN:      Status
 487  *
 488  * DESCRIPTION: Load the namespace from the DSDT and all SSDTs/PSDTs found in
 489  *              the RSDT/XSDT.
 490  *
 491  ******************************************************************************/
 492 static acpi_status acpi_tb_load_namespace(void)
 493 {
 494         acpi_status status;
 495         struct acpi_table_header *table;
 496         acpi_native_uint i;
 497
 498         ACPI_FUNCTION_TRACE(tb_load_namespace);
 499
 500         (void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
 501
 502         /*
 503          * Load the namespace. The DSDT is required, but any SSDT and PSDT tables
 504          * are optional.
 505          */
 506         if (!acpi_gbl_root_table_list.count ||
 507             !ACPI_COMPARE_NAME(&
 508                                (acpi_gbl_root_table_list.
 509                                 tables[ACPI_TABLE_INDEX_DSDT].signature),
 510                                ACPI_SIG_DSDT)
 511             ||
 512             ACPI_FAILURE(acpi_tb_verify_table
 513                          (&acpi_gbl_root_table_list.
 514                           tables[ACPI_TABLE_INDEX_DSDT]))) {
 515                 status = AE_NO_ACPI_TABLES;
 516                 goto unlock_and_exit;
 517         }
 518
 519         /*
 520          * Find DSDT table
 521          */
 522         status =
 523             acpi_os_table_override(acpi_gbl_root_table_list.
 524                                    tables[ACPI_TABLE_INDEX_DSDT].pointer,
 525                                    &table);
 526         if (ACPI_SUCCESS(status) && table) {
 527                 /*
 528                  * DSDT table has been found
 529                  */
 530                 acpi_tb_delete_table(&acpi_gbl_root_table_list.
 531                                      tables[ACPI_TABLE_INDEX_DSDT]);
 532                 acpi_gbl_root_table_list.tables[ACPI_TABLE_INDEX_DSDT].pointer =
 533                     table;
 534                 acpi_gbl_root_table_list.tables[ACPI_TABLE_INDEX_DSDT].length =
 535                     table->length;
 536                 acpi_gbl_root_table_list.tables[ACPI_TABLE_INDEX_DSDT].flags =
 537                     ACPI_TABLE_ORIGIN_UNKNOWN;
 538
 539                 ACPI_INFO((AE_INFO, "Table DSDT replaced by host OS"));
 540                 acpi_tb_print_table_header(0, table);
 541
 542                 if (no_auto_ssdt == 0) {
 543                         printk(KERN_WARNING "ACPI: DSDT override uses original SSDTs unless \"acpi_no_auto_ssdt\"");
 544                 }
 545         }
 546
 547         status =
 548             acpi_tb_verify_table(&acpi_gbl_root_table_list.
 549                                  tables[ACPI_TABLE_INDEX_DSDT]);
 550         if (ACPI_FAILURE(status)) {
 551
 552                 /* A valid DSDT is required */
 553
 554                 status = AE_NO_ACPI_TABLES;
 555                 goto unlock_and_exit;
 556         }
 557
 558         (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
 559
 560         /*
 561          * Load and parse tables.
 562          */
 563         status = acpi_ns_load_table(ACPI_TABLE_INDEX_DSDT, acpi_gbl_root_node);
 564         if (ACPI_FAILURE(status)) {
 565                 return_ACPI_STATUS(status);
 566         }
 567
 568         /*
 569          * Load any SSDT or PSDT tables. Note: Loop leaves tables locked
 570          */
 571         (void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
 572         for (i = 0; i < acpi_gbl_root_table_list.count; ++i) {
 573                 if ((!ACPI_COMPARE_NAME
 574                      (&(acpi_gbl_root_table_list.tables[i].signature),
 575                       ACPI_SIG_SSDT)
 576                      &&
 577                      !ACPI_COMPARE_NAME(&
 578                                         (acpi_gbl_root_table_list.tables[i].
 579                                          signature), ACPI_SIG_PSDT))
 580                     ||
 581                     ACPI_FAILURE(acpi_tb_verify_table
 582                                  (&acpi_gbl_root_table_list.tables[i]))) {
 583                         continue;
 584                 }
 585
 586                 if (no_auto_ssdt) {
 587                         printk(KERN_WARNING "ACPI: SSDT ignored due to \"acpi_no_auto_ssdt\"\n");
 588                         continue;
 589                 }
 590
 591                 /* Ignore errors while loading tables, get as many as possible */
 592
 593                 (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
 594                 (void)acpi_ns_load_table(i, acpi_gbl_root_node);
 595                 (void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
 596         }
 597
 598         ACPI_DEBUG_PRINT((ACPI_DB_INIT, "ACPI Tables successfully acquired\n"));
 599
 600       unlock_and_exit:
 601         (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
 602         return_ACPI_STATUS(status);
 603 }
 604
 605 /*******************************************************************************
 606  *
 607  * FUNCTION:    acpi_load_tables
 608  *
 609  * PARAMETERS:  None
 610  *
 611  * RETURN:      Status
 612  *
 613  * DESCRIPTION: Load the ACPI tables from the RSDT/XSDT
 614  *
 615  ******************************************************************************/
 616
 617 acpi_status acpi_load_tables(void)
 618 {
 619         acpi_status status;
 620
 621         ACPI_FUNCTION_TRACE(acpi_load_tables);
 622
 623         /*
 624          * Load the namespace from the tables
 625          */
 626         status = acpi_tb_load_namespace();
 627         if (ACPI_FAILURE(status)) {
 628                 ACPI_EXCEPTION((AE_INFO, status,
 629                                 "While loading namespace from ACPI tables"));
 630         }
 631
 632         return_ACPI_STATUS(status);
 633 }
 634
 635 ACPI_EXPORT_SYMBOL(acpi_load_tables)
 636
 637
 638 static int __init acpi_no_auto_ssdt_setup(char *s) {
 639
 640         printk(KERN_NOTICE "ACPI: SSDT auto-load disabled\n");
 641
 642         no_auto_ssdt = 1;
 643
 644         return 1;
 645 }
 646
 647 __setup("acpi_no_auto_ssdt", acpi_no_auto_ssdt_setup);