LXR linux/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
  51ACPI_MODULE_NAME("tbxface")
  52
  53/* Local prototypes */
  54static acpi_status acpi_tb_load_namespace(void);
  55
  56static 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
  72acpi_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
 107acpi_status __init
 108acpi_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 ******************************************************************************/
 171acpi_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 ******************************************************************************/
 222acpi_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
 247ACPI_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 ******************************************************************************/
 265acpi_status
 266acpi_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
 323ACPI_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 ******************************************************************************/
 336acpi_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
 362ACPI_EXPORT_SYMBOL(acpi_unload_table_id)
 363
 364/*******************************************************************************
 365 *
 366 * FUNCTION:    acpi_get_table_with_size
 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 ******************************************************************************/
 377acpi_status
 378acpi_get_table_with_size(char *signature,
 379               u32 instance, struct acpi_table_header **out_table,
 380               acpi_size *tbl_size)
 381{
 382       u32 i;
 383       u32 j;
 384        acpi_status status;
 385
 386        /* Parameter validation */
 387
 388        if (!signature || !out_table) {
 389                return (AE_BAD_PARAMETER);
 390        }
 391
 392        /* Walk the root table list */
 393
 394        for (i = 0, j = 0; i < acpi_gbl_root_table_list.count; i++) {
 395                if (!ACPI_COMPARE_NAME
 396                    (&(acpi_gbl_root_table_list.tables[i].signature),
 397                     signature)) {
 398                        continue;
 399                }
 400
 401                if (++j < instance) {
 402                        continue;
 403                }
 404
 405                status =
 406                    acpi_tb_verify_table(&acpi_gbl_root_table_list.tables[i]);
 407                if (ACPI_SUCCESS(status)) {
 408                        *out_table = acpi_gbl_root_table_list.tables[i].pointer;
 409                        *tbl_size = acpi_gbl_root_table_list.tables[i].length;
 410                }
 411
 412                if (!acpi_gbl_permanent_mmap) {
 413                        acpi_gbl_root_table_list.tables[i].pointer = NULL;
 414                }
 415
 416                return (status);
 417        }
 418
 419        return (AE_NOT_FOUND);
 420}
 421
 422acpi_status
 423acpi_get_table(char *signature,
 424               u32 instance, struct acpi_table_header **out_table)
 425{
 426        acpi_size tbl_size;
 427
 428        return acpi_get_table_with_size(signature,
 429                       instance, out_table, &tbl_size);
 430}
 431ACPI_EXPORT_SYMBOL(acpi_get_table)
 432
 433/*******************************************************************************
 434 *
 435 * FUNCTION:    acpi_get_table_by_index
 436 *
 437 * PARAMETERS:  table_index         - Table index
 438 *              Table               - Where the pointer to the table is returned
 439 *
 440 * RETURN:      Status and pointer to the table
 441 *
 442 * DESCRIPTION: Obtain a table by an index into the global table list.
 443 *
 444 ******************************************************************************/
 445acpi_status
 446acpi_get_table_by_index(u32 table_index, struct acpi_table_header **table)
 447{
 448        acpi_status status;
 449
 450        ACPI_FUNCTION_TRACE(acpi_get_table_by_index);
 451
 452        /* Parameter validation */
 453
 454        if (!table) {
 455                return_ACPI_STATUS(AE_BAD_PARAMETER);
 456        }
 457
 458        (void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
 459
 460        /* Validate index */
 461
 462        if (table_index >= acpi_gbl_root_table_list.count) {
 463                (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
 464                return_ACPI_STATUS(AE_BAD_PARAMETER);
 465        }
 466
 467        if (!acpi_gbl_root_table_list.tables[table_index].pointer) {
 468
 469                /* Table is not mapped, map it */
 470
 471                status =
 472                    acpi_tb_verify_table(&acpi_gbl_root_table_list.
 473                                         tables[table_index]);
 474                if (ACPI_FAILURE(status)) {
 475                        (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
 476                        return_ACPI_STATUS(status);
 477                }
 478        }
 479
 480        *table = acpi_gbl_root_table_list.tables[table_index].pointer;
 481        (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
 482        return_ACPI_STATUS(AE_OK);
 483}
 484
 485ACPI_EXPORT_SYMBOL(acpi_get_table_by_index)
 486
 487/*******************************************************************************
 488 *
 489 * FUNCTION:    acpi_tb_load_namespace
 490 *
 491 * PARAMETERS:  None
 492 *
 493 * RETURN:      Status
 494 *
 495 * DESCRIPTION: Load the namespace from the DSDT and all SSDTs/PSDTs found in
 496 *              the RSDT/XSDT.
 497 *
 498 ******************************************************************************/
 499static acpi_status acpi_tb_load_namespace(void)
 500{
 501        acpi_status status;
 502        u32 i;
 503
 504        ACPI_FUNCTION_TRACE(tb_load_namespace);
 505
 506        (void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
 507
 508        /*
 509         * Load the namespace. The DSDT is required, but any SSDT and PSDT tables
 510         * are optional.
 511         */
 512        if (!acpi_gbl_root_table_list.count ||
 513            !ACPI_COMPARE_NAME(&
 514                               (acpi_gbl_root_table_list.
 515                                tables[ACPI_TABLE_INDEX_DSDT].signature),
 516                               ACPI_SIG_DSDT)
 517            ||
 518            ACPI_FAILURE(acpi_tb_verify_table
 519                         (&acpi_gbl_root_table_list.
 520                          tables[ACPI_TABLE_INDEX_DSDT]))) {
 521                status = AE_NO_ACPI_TABLES;
 522                goto unlock_and_exit;
 523        }
 524
 525        /* A valid DSDT is required */
 526
 527        status =
 528            acpi_tb_verify_table(&acpi_gbl_root_table_list.
 529                                 tables[ACPI_TABLE_INDEX_DSDT]);
 530        if (ACPI_FAILURE(status)) {
 531
 532                status = AE_NO_ACPI_TABLES;
 533                goto unlock_and_exit;
 534        }
 535
 536        (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
 537
 538        /* Load and parse tables */
 539
 540        status = acpi_ns_load_table(ACPI_TABLE_INDEX_DSDT, acpi_gbl_root_node);
 541        if (ACPI_FAILURE(status)) {
 542                return_ACPI_STATUS(status);
 543        }
 544
 545        /* Load any SSDT or PSDT tables. Note: Loop leaves tables locked */
 546
 547        (void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
 548        for (i = 0; i < acpi_gbl_root_table_list.count; ++i) {
 549                if ((!ACPI_COMPARE_NAME
 550                     (&(acpi_gbl_root_table_list.tables[i].signature),
 551                      ACPI_SIG_SSDT)
 552                     &&
 553                     !ACPI_COMPARE_NAME(&
 554                                        (acpi_gbl_root_table_list.tables[i].
 555                                         signature), ACPI_SIG_PSDT))
 556                    ||
 557                    ACPI_FAILURE(acpi_tb_verify_table
 558                                 (&acpi_gbl_root_table_list.tables[i]))) {
 559                        continue;
 560                }
 561
 562                if (no_auto_ssdt) {
 563                        printk(KERN_WARNING "ACPI: SSDT ignored due to \"acpi_no_auto_ssdt\"\n");
 564                        continue;
 565                }
 566
 567                /* Ignore errors while loading tables, get as many as possible */
 568
 569                (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
 570                (void)acpi_ns_load_table(i, acpi_gbl_root_node);
 571                (void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
 572        }
 573
 574        ACPI_DEBUG_PRINT((ACPI_DB_INIT, "ACPI Tables successfully acquired\n"));
 575
 576      unlock_and_exit:
 577        (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
 578        return_ACPI_STATUS(status);
 579}
 580
 581/*******************************************************************************
 582 *
 583 * FUNCTION:    acpi_load_tables
 584 *
 585 * PARAMETERS:  None
 586 *
 587 * RETURN:      Status
 588 *
 589 * DESCRIPTION: Load the ACPI tables from the RSDT/XSDT
 590 *
 591 ******************************************************************************/
 592
 593acpi_status acpi_load_tables(void)
 594{
 595        acpi_status status;
 596
 597        ACPI_FUNCTION_TRACE(acpi_load_tables);
 598
 599        /* Load the namespace from the tables */
 600
 601        status = acpi_tb_load_namespace();
 602        if (ACPI_FAILURE(status)) {
 603                ACPI_EXCEPTION((AE_INFO, status,
 604                                "While loading namespace from ACPI tables"));
 605        }
 606
 607        return_ACPI_STATUS(status);
 608}
 609
 610ACPI_EXPORT_SYMBOL(acpi_load_tables)
 611
 612
 613/*******************************************************************************
 614 *
 615 * FUNCTION:    acpi_install_table_handler
 616 *
 617 * PARAMETERS:  Handler         - Table event handler
 618 *              Context         - Value passed to the handler on each event
 619 *
 620 * RETURN:      Status
 621 *
 622 * DESCRIPTION: Install table event handler
 623 *
 624 ******************************************************************************/
 625acpi_status
 626acpi_install_table_handler(acpi_tbl_handler handler, void *context)
 627{
 628        acpi_status status;
 629
 630        ACPI_FUNCTION_TRACE(acpi_install_table_handler);
 631
 632        if (!handler) {
 633                return_ACPI_STATUS(AE_BAD_PARAMETER);
 634        }
 635
 636        status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
 637        if (ACPI_FAILURE(status)) {
 638                return_ACPI_STATUS(status);
 639        }
 640
 641        /* Don't allow more than one handler */
 642
 643        if (acpi_gbl_table_handler) {
 644                status = AE_ALREADY_EXISTS;
 645                goto cleanup;
 646        }
 647
 648        /* Install the handler */
 649
 650        acpi_gbl_table_handler = handler;
 651        acpi_gbl_table_handler_context = context;
 652
 653      cleanup:
 654        (void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
 655        return_ACPI_STATUS(status);
 656}
 657
 658ACPI_EXPORT_SYMBOL(acpi_install_table_handler)
 659
 660/*******************************************************************************
 661 *
 662 * FUNCTION:    acpi_remove_table_handler
 663 *
 664 * PARAMETERS:  Handler         - Table event handler that was installed
 665 *                                previously.
 666 *
 667 * RETURN:      Status
 668 *
 669 * DESCRIPTION: Remove table event handler
 670 *
 671 ******************************************************************************/
 672acpi_status acpi_remove_table_handler(acpi_tbl_handler handler)
 673{
 674        acpi_status status;
 675
 676        ACPI_FUNCTION_TRACE(acpi_remove_table_handler);
 677
 678        status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
 679        if (ACPI_FAILURE(status)) {
 680                return_ACPI_STATUS(status);
 681        }
 682
 683        /* Make sure that the installed handler is the same */
 684
 685        if (!handler || handler != acpi_gbl_table_handler) {
 686                status = AE_BAD_PARAMETER;
 687                goto cleanup;
 688        }
 689
 690        /* Remove the handler */
 691
 692        acpi_gbl_table_handler = NULL;
 693
 694      cleanup:
 695        (void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
 696        return_ACPI_STATUS(status);
 697}
 698
 699ACPI_EXPORT_SYMBOL(acpi_remove_table_handler)
 700
 701
 702static int __init acpi_no_auto_ssdt_setup(char *s) {
 703
 704        printk(KERN_NOTICE "ACPI: SSDT auto-load disabled\n");
 705
 706        no_auto_ssdt = 1;
 707
 708        return 1;
 709}
 710
 711__setup("acpi_no_auto_ssdt", acpi_no_auto_ssdt_setup);
 712