git.oblomov.eu Git - linux-2.6/blob - 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_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  ******************************************************************************/
 377 acpi_status
 378 acpi_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
 422 acpi_status
 423 acpi_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 }
 431 ACPI_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  ******************************************************************************/
 445 acpi_status
 446 acpi_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
 485 ACPI_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  ******************************************************************************/
 499 static 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
 593 acpi_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
 610 ACPI_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  ******************************************************************************/
 625 acpi_status
 626 acpi_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
 658 ACPI_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  ******************************************************************************/
 672 acpi_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
 699 ACPI_EXPORT_SYMBOL(acpi_remove_table_handler)
 700
 701
 702 static 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);