drivers/acpi/acpica/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 - 2008, Intel Corp.
  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 "accommon.h"
  47 #include "acnamesp.h"
  48 #include "actables.h"
  49
  50 #define _COMPONENT          ACPI_TABLES
  51 ACPI_MODULE_NAME("tbxface")
  52
  53 /* Local prototypes */
  54 static acpi_status acpi_tb_load_namespace(void);
  55
  56 static int no_auto_ssdt;
  57
  58 /*******************************************************************************
  59  *
  60  * FUNCTION:    acpi_allocate_root_table
  61  *
  62  * PARAMETERS:  initial_table_count - Size of initial_table_array, in number of
  63  *                                    struct acpi_table_desc structures
  64  *
  65  * RETURN:      Status
  66  *
  67  * DESCRIPTION: Allocate a root table array. Used by i_aSL compiler and
  68  *              acpi_initialize_tables.
  69  *
  70  ******************************************************************************/
  71
  72 acpi_status acpi_allocate_root_table(u32 initial_table_count)
  73 {
  74
  75         acpi_gbl_root_table_list.size = initial_table_count;
  76         acpi_gbl_root_table_list.flags = ACPI_ROOT_ALLOW_RESIZE;
  77
  78         return (acpi_tb_resize_root_table_list());
  79 }
  80
  81 /*******************************************************************************
  82  *
  83  * FUNCTION:    acpi_initialize_tables
  84  *
  85  * PARAMETERS:  initial_table_array - Pointer to an array of pre-allocated
  86  *                                    struct acpi_table_desc structures. If NULL, the
  87  *                                    array is dynamically allocated.
  88  *              initial_table_count - Size of initial_table_array, in number of
  89  *                                    struct acpi_table_desc structures
  90  *              allow_realloc       - Flag to tell Table Manager if resize of
  91  *                                    pre-allocated array is allowed. Ignored
  92  *                                    if initial_table_array is NULL.
  93  *
  94  * RETURN:      Status
  95  *
  96  * DESCRIPTION: Initialize the table manager, get the RSDP and RSDT/XSDT.
  97  *
  98  * NOTE:        Allows static allocation of the initial table array in order
  99  *              to avoid the use of dynamic memory in confined environments
 100  *              such as the kernel boot sequence where it may not be available.
 101  *
 102  *              If the host OS memory managers are initialized, use NULL for
 103  *              initial_table_array, and the table will be dynamically allocated.
 104  *
 105  ******************************************************************************/
 106
 107 acpi_status __init
 108 acpi_initialize_tables(struct acpi_table_desc * initial_table_array,
 109                        u32 initial_table_count, u8 allow_resize)
 110 {
 111         acpi_physical_address rsdp_address;
 112         acpi_status status;
 113
 114         ACPI_FUNCTION_TRACE(acpi_initialize_tables);
 115
 116         /*
 117          * Set up the Root Table Array
 118          * Allocate the table array if requested
 119          */
 120         if (!initial_table_array) {
 121                 status = acpi_allocate_root_table(initial_table_count);
 122                 if (ACPI_FAILURE(status)) {
 123                         return_ACPI_STATUS(status);
 124                 }
 125         } else {
 126                 /* Root Table Array has been statically allocated by the host */
 127
 128                 ACPI_MEMSET(initial_table_array, 0,
 129                             (acpi_size) initial_table_count *
 130                             sizeof(struct acpi_table_desc));
 131
 132                 acpi_gbl_root_table_list.tables = initial_table_array;
 133                 acpi_gbl_root_table_list.size = initial_table_count;
 134                 acpi_gbl_root_table_list.flags = ACPI_ROOT_ORIGIN_UNKNOWN;
 135                 if (allow_resize) {
 136                         acpi_gbl_root_table_list.flags |=
 137                             ACPI_ROOT_ALLOW_RESIZE;
 138                 }
 139         }
 140
 141         /* Get the address of the RSDP */
 142
 143         rsdp_address = acpi_os_get_root_pointer();
 144         if (!rsdp_address) {
 145                 return_ACPI_STATUS(AE_NOT_FOUND);
 146         }
 147
 148         /*
 149          * Get the root table (RSDT or XSDT) and extract all entries to the local
 150          * Root Table Array. This array contains the information of the RSDT/XSDT
 151          * in a common, more useable format.
 152          */
 153         status = acpi_tb_parse_root_table(rsdp_address);
 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 = ((acpi_size) acpi_gbl_root_table_list.count +
 187                     ACPI_ROOT_TABLE_SIZE_INCREMENT) *
 188             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         u32 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                       u32 instance, struct acpi_table_header *out_table_header)
 268 {
 269        u32 i;
 270        u32 j;
 271         struct acpi_table_header *header;
 272
 273         /* Parameter validation */
 274
 275         if (!signature || !out_table_header) {
 276                 return (AE_BAD_PARAMETER);
 277         }
 278
 279         /* Walk the root table list */
 280
 281         for (i = 0, j = 0; i < acpi_gbl_root_table_list.count; i++) {
 282                 if (!ACPI_COMPARE_NAME
 283                     (&(acpi_gbl_root_table_list.tables[i].signature),
 284                      signature)) {
 285                         continue;
 286                 }
 287
 288                 if (++j < instance) {
 289                         continue;
 290                 }
 291
 292                 if (!acpi_gbl_root_table_list.tables[i].pointer) {
 293                         if ((acpi_gbl_root_table_list.tables[i].flags &
 294                              ACPI_TABLE_ORIGIN_MASK) ==
 295                             ACPI_TABLE_ORIGIN_MAPPED) {
 296                                 header =
 297                                     acpi_os_map_memory(acpi_gbl_root_table_list.
 298                                                        tables[i].address,
 299                                                        sizeof(struct
 300                                                               acpi_table_header));
 301                                 if (!header) {
 302                                         return AE_NO_MEMORY;
 303                                 }
 304                                 ACPI_MEMCPY(out_table_header, header,
 305                                             sizeof(struct acpi_table_header));
 306                                 acpi_os_unmap_memory(header,
 307                                                      sizeof(struct
 308                                                             acpi_table_header));
 309                         } else {
 310                                 return AE_NOT_FOUND;
 311                         }
 312                 } else {
 313                         ACPI_MEMCPY(out_table_header,
 314                                     acpi_gbl_root_table_list.tables[i].pointer,
 315                                     sizeof(struct acpi_table_header));
 316                 }
 317                 return (AE_OK);
 318         }
 319
 320         return (AE_NOT_FOUND);
 321 }
 322
 323 ACPI_EXPORT_SYMBOL(acpi_get_table_header)
 324
 325 /*******************************************************************************
 326  *
 327  * FUNCTION:    acpi_unload_table_id
 328  *
 329  * PARAMETERS:  id            - Owner ID of the table to be removed.
 330  *
 331  * RETURN:      Status
 332  *
 333  * DESCRIPTION: This routine is used to force the unload of a table (by id)
 334  *
 335  ******************************************************************************/
 336 acpi_status acpi_unload_table_id(acpi_owner_id id)
 337 {
 338         int i;
 339         acpi_status status = AE_NOT_EXIST;
 340
 341         ACPI_FUNCTION_TRACE(acpi_unload_table_id);
 342
 343         /* Find table in the global table list */
 344         for (i = 0; i < acpi_gbl_root_table_list.count; ++i) {
 345                 if (id != acpi_gbl_root_table_list.tables[i].owner_id) {
 346                         continue;
 347                 }
 348                 /*
 349                  * Delete all namespace objects owned by this table. Note that these
 350                  * objects can appear anywhere in the namespace by virtue of the AML
 351                  * "Scope" operator. Thus, we need to track ownership by an ID, not
 352                  * simply a position within the hierarchy
 353                  */
 354                 acpi_tb_delete_namespace_by_owner(i);
 355                 status = acpi_tb_release_owner_id(i);
 356                 acpi_tb_set_table_loaded_flag(i, FALSE);
 357                 break;
 358         }
 359         return_ACPI_STATUS(status);
 360 }
 361
 362 ACPI_EXPORT_SYMBOL(acpi_unload_table_id)
 363
 364 /*******************************************************************************
 365  *
 366  * FUNCTION:    acpi_get_table
 367  *
 368  * PARAMETERS:  Signature           - ACPI signature of needed table
 369  *              Instance            - Which instance (for SSDTs)
 370  *              out_table           - Where the pointer to the table is returned
 371  *
 372  * RETURN:      Status and pointer to table
 373  *
 374  * DESCRIPTION: Finds and verifies an ACPI table.
 375  *
 376  ******************************************************************************/
 377 acpi_status
 378 acpi_get_table(char *signature,
 379                u32 instance, struct acpi_table_header **out_table)
 380 {
 381        u32 i;
 382        u32 j;
 383         acpi_status status;
 384
 385         /* Parameter validation */
 386
 387         if (!signature || !out_table) {
 388                 return (AE_BAD_PARAMETER);
 389         }
 390
 391         /* Walk the root table list */
 392
 393         for (i = 0, j = 0; i < acpi_gbl_root_table_list.count; i++) {
 394                 if (!ACPI_COMPARE_NAME
 395                     (&(acpi_gbl_root_table_list.tables[i].signature),
 396                      signature)) {
 397                         continue;
 398                 }
 399
 400                 if (++j < instance) {
 401                         continue;
 402                 }
 403
 404                 status =
 405                     acpi_tb_verify_table(&acpi_gbl_root_table_list.tables[i]);
 406                 if (ACPI_SUCCESS(status)) {
 407                         *out_table = acpi_gbl_root_table_list.tables[i].pointer;
 408                 }
 409
 410                 if (!acpi_gbl_permanent_mmap) {
 411                         acpi_gbl_root_table_list.tables[i].pointer = NULL;
 412                 }
 413
 414                 return (status);
 415         }
 416
 417         return (AE_NOT_FOUND);
 418 }
 419
 420 ACPI_EXPORT_SYMBOL(acpi_get_table)
 421
 422 /*******************************************************************************
 423  *
 424  * FUNCTION:    acpi_get_table_by_index
 425  *
 426  * PARAMETERS:  table_index         - Table index
 427  *              Table               - Where the pointer to the table is returned
 428  *
 429  * RETURN:      Status and pointer to the table
 430  *
 431  * DESCRIPTION: Obtain a table by an index into the global table list.
 432  *
 433  ******************************************************************************/
 434 acpi_status
 435 acpi_get_table_by_index(u32 table_index, struct acpi_table_header **table)
 436 {
 437         acpi_status status;
 438
 439         ACPI_FUNCTION_TRACE(acpi_get_table_by_index);
 440
 441         /* Parameter validation */
 442
 443         if (!table) {
 444                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 445         }
 446
 447         (void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
 448
 449         /* Validate index */
 450
 451         if (table_index >= acpi_gbl_root_table_list.count) {
 452                 (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
 453                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 454         }
 455
 456         if (!acpi_gbl_root_table_list.tables[table_index].pointer) {
 457
 458                 /* Table is not mapped, map it */
 459
 460                 status =
 461                     acpi_tb_verify_table(&acpi_gbl_root_table_list.
 462                                          tables[table_index]);
 463                 if (ACPI_FAILURE(status)) {
 464                         (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
 465                         return_ACPI_STATUS(status);
 466                 }
 467         }
 468
 469         *table = acpi_gbl_root_table_list.tables[table_index].pointer;
 470         (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
 471         return_ACPI_STATUS(AE_OK);
 472 }
 473
 474 ACPI_EXPORT_SYMBOL(acpi_get_table_by_index)
 475
 476 /*******************************************************************************
 477  *
 478  * FUNCTION:    acpi_tb_load_namespace
 479  *
 480  * PARAMETERS:  None
 481  *
 482  * RETURN:      Status
 483  *
 484  * DESCRIPTION: Load the namespace from the DSDT and all SSDTs/PSDTs found in
 485  *              the RSDT/XSDT.
 486  *
 487  ******************************************************************************/
 488 static acpi_status acpi_tb_load_namespace(void)
 489 {
 490         acpi_status status;
 491         u32 i;
 492
 493         ACPI_FUNCTION_TRACE(tb_load_namespace);
 494
 495         (void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
 496
 497         /*
 498          * Load the namespace. The DSDT is required, but any SSDT and PSDT tables
 499          * are optional.
 500          */
 501         if (!acpi_gbl_root_table_list.count ||
 502             !ACPI_COMPARE_NAME(&
 503                                (acpi_gbl_root_table_list.
 504                                 tables[ACPI_TABLE_INDEX_DSDT].signature),
 505                                ACPI_SIG_DSDT)
 506             ||
 507             ACPI_FAILURE(acpi_tb_verify_table
 508                          (&acpi_gbl_root_table_list.
 509                           tables[ACPI_TABLE_INDEX_DSDT]))) {
 510                 status = AE_NO_ACPI_TABLES;
 511                 goto unlock_and_exit;
 512         }
 513
 514         /* A valid DSDT is required */
 515
 516         status =
 517             acpi_tb_verify_table(&acpi_gbl_root_table_list.
 518                                  tables[ACPI_TABLE_INDEX_DSDT]);
 519         if (ACPI_FAILURE(status)) {
 520
 521                 status = AE_NO_ACPI_TABLES;
 522                 goto unlock_and_exit;
 523         }
 524
 525         (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
 526
 527         /* Load and parse tables */
 528
 529         status = acpi_ns_load_table(ACPI_TABLE_INDEX_DSDT, acpi_gbl_root_node);
 530         if (ACPI_FAILURE(status)) {
 531                 return_ACPI_STATUS(status);
 532         }
 533
 534         /* Load any SSDT or PSDT tables. Note: Loop leaves tables locked */
 535
 536         (void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
 537         for (i = 0; i < acpi_gbl_root_table_list.count; ++i) {
 538                 if ((!ACPI_COMPARE_NAME
 539                      (&(acpi_gbl_root_table_list.tables[i].signature),
 540                       ACPI_SIG_SSDT)
 541                      &&
 542                      !ACPI_COMPARE_NAME(&
 543                                         (acpi_gbl_root_table_list.tables[i].
 544                                          signature), ACPI_SIG_PSDT))
 545                     ||
 546                     ACPI_FAILURE(acpi_tb_verify_table
 547                                  (&acpi_gbl_root_table_list.tables[i]))) {
 548                         continue;
 549                 }
 550
 551                 if (no_auto_ssdt) {
 552                         printk(KERN_WARNING "ACPI: SSDT ignored due to \"acpi_no_auto_ssdt\"\n");
 553                         continue;
 554                 }
 555
 556                 /* Ignore errors while loading tables, get as many as possible */
 557
 558                 (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
 559                 (void)acpi_ns_load_table(i, acpi_gbl_root_node);
 560                 (void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
 561         }
 562
 563         ACPI_DEBUG_PRINT((ACPI_DB_INIT, "ACPI Tables successfully acquired\n"));
 564
 565       unlock_and_exit:
 566         (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
 567         return_ACPI_STATUS(status);
 568 }
 569
 570 /*******************************************************************************
 571  *
 572  * FUNCTION:    acpi_load_tables
 573  *
 574  * PARAMETERS:  None
 575  *
 576  * RETURN:      Status
 577  *
 578  * DESCRIPTION: Load the ACPI tables from the RSDT/XSDT
 579  *
 580  ******************************************************************************/
 581
 582 acpi_status acpi_load_tables(void)
 583 {
 584         acpi_status status;
 585
 586         ACPI_FUNCTION_TRACE(acpi_load_tables);
 587
 588         /* Load the namespace from the tables */
 589
 590         status = acpi_tb_load_namespace();
 591         if (ACPI_FAILURE(status)) {
 592                 ACPI_EXCEPTION((AE_INFO, status,
 593                                 "While loading namespace from ACPI tables"));
 594         }
 595
 596         return_ACPI_STATUS(status);
 597 }
 598
 599 ACPI_EXPORT_SYMBOL(acpi_load_tables)
 600
 601
 602 /*******************************************************************************
 603  *
 604  * FUNCTION:    acpi_install_table_handler
 605  *
 606  * PARAMETERS:  Handler         - Table event handler
 607  *              Context         - Value passed to the handler on each event
 608  *
 609  * RETURN:      Status
 610  *
 611  * DESCRIPTION: Install table event handler
 612  *
 613  ******************************************************************************/
 614 acpi_status
 615 acpi_install_table_handler(acpi_tbl_handler handler, void *context)
 616 {
 617         acpi_status status;
 618
 619         ACPI_FUNCTION_TRACE(acpi_install_table_handler);
 620
 621         if (!handler) {
 622                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 623         }
 624
 625         status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
 626         if (ACPI_FAILURE(status)) {
 627                 return_ACPI_STATUS(status);
 628         }
 629
 630         /* Don't allow more than one handler */
 631
 632         if (acpi_gbl_table_handler) {
 633                 status = AE_ALREADY_EXISTS;
 634                 goto cleanup;
 635         }
 636
 637         /* Install the handler */
 638
 639         acpi_gbl_table_handler = handler;
 640         acpi_gbl_table_handler_context = context;
 641
 642       cleanup:
 643         (void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
 644         return_ACPI_STATUS(status);
 645 }
 646
 647 ACPI_EXPORT_SYMBOL(acpi_install_table_handler)
 648
 649 /*******************************************************************************
 650  *
 651  * FUNCTION:    acpi_remove_table_handler
 652  *
 653  * PARAMETERS:  Handler         - Table event handler that was installed
 654  *                                previously.
 655  *
 656  * RETURN:      Status
 657  *
 658  * DESCRIPTION: Remove table event handler
 659  *
 660  ******************************************************************************/
 661 acpi_status acpi_remove_table_handler(acpi_tbl_handler handler)
 662 {
 663         acpi_status status;
 664
 665         ACPI_FUNCTION_TRACE(acpi_remove_table_handler);
 666
 667         status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
 668         if (ACPI_FAILURE(status)) {
 669                 return_ACPI_STATUS(status);
 670         }
 671
 672         /* Make sure that the installed handler is the same */
 673
 674         if (!handler || handler != acpi_gbl_table_handler) {
 675                 status = AE_BAD_PARAMETER;
 676                 goto cleanup;
 677         }
 678
 679         /* Remove the handler */
 680
 681         acpi_gbl_table_handler = NULL;
 682
 683       cleanup:
 684         (void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
 685         return_ACPI_STATUS(status);
 686 }
 687
 688 ACPI_EXPORT_SYMBOL(acpi_remove_table_handler)
 689
 690
 691 static int __init acpi_no_auto_ssdt_setup(char *s) {
 692
 693         printk(KERN_NOTICE "ACPI: SSDT auto-load disabled\n");
 694
 695         no_auto_ssdt = 1;
 696
 697         return 1;
 698 }
 699
 700 __setup("acpi_no_auto_ssdt", acpi_no_auto_ssdt_setup);