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 - 2010, 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         acpi_size current_size;
 176
 177         ACPI_FUNCTION_TRACE(acpi_reallocate_root_table);
 178
 179         /*
 180          * Only reallocate the root table if the host provided a static buffer
 181          * for the table array in the call to acpi_initialize_tables.
 182          */
 183         if (acpi_gbl_root_table_list.flags & ACPI_ROOT_ORIGIN_ALLOCATED) {
 184                 return_ACPI_STATUS(AE_SUPPORT);
 185         }
 186
 187         /*
 188          * Get the current size of the root table and add the default
 189          * increment to create the new table size.
 190          */
 191         current_size = (acpi_size)
 192             acpi_gbl_root_table_list.count * sizeof(struct acpi_table_desc);
 193
 194         new_size = current_size +
 195             (ACPI_ROOT_TABLE_SIZE_INCREMENT * sizeof(struct acpi_table_desc));
 196
 197         /* Create new array and copy the old array */
 198
 199         tables = ACPI_ALLOCATE_ZEROED(new_size);
 200         if (!tables) {
 201                 return_ACPI_STATUS(AE_NO_MEMORY);
 202         }
 203
 204         ACPI_MEMCPY(tables, acpi_gbl_root_table_list.tables, current_size);
 205
 206         /*
 207          * Update the root table descriptor. The new size will be the current
 208          * number of tables plus the increment, independent of the reserved
 209          * size of the original table list.
 210          */
 211         acpi_gbl_root_table_list.tables = tables;
 212         acpi_gbl_root_table_list.size =
 213             acpi_gbl_root_table_list.count + ACPI_ROOT_TABLE_SIZE_INCREMENT;
 214         acpi_gbl_root_table_list.flags =
 215             ACPI_ROOT_ORIGIN_ALLOCATED | ACPI_ROOT_ALLOW_RESIZE;
 216
 217         return_ACPI_STATUS(AE_OK);
 218 }
 219
 220 /*******************************************************************************
 221  *
 222  * FUNCTION:    acpi_load_table
 223  *
 224  * PARAMETERS:  table_ptr       - pointer to a buffer containing the entire
 225  *                                table to be loaded
 226  *
 227  * RETURN:      Status
 228  *
 229  * DESCRIPTION: This function is called to load a table from the caller's
 230  *              buffer. The buffer must contain an entire ACPI Table including
 231  *              a valid header. The header fields will be verified, and if it
 232  *              is determined that the table is invalid, the call will fail.
 233  *
 234  ******************************************************************************/
 235 acpi_status acpi_load_table(struct acpi_table_header *table_ptr)
 236 {
 237         acpi_status status;
 238         u32 table_index;
 239         struct acpi_table_desc table_desc;
 240
 241         if (!table_ptr)
 242                 return AE_BAD_PARAMETER;
 243
 244         ACPI_MEMSET(&table_desc, 0, sizeof(struct acpi_table_desc));
 245         table_desc.pointer = table_ptr;
 246         table_desc.length = table_ptr->length;
 247         table_desc.flags = ACPI_TABLE_ORIGIN_UNKNOWN;
 248
 249         /*
 250          * Install the new table into the local data structures
 251          */
 252         status = acpi_tb_add_table(&table_desc, &table_index);
 253         if (ACPI_FAILURE(status)) {
 254                 return status;
 255         }
 256         status = acpi_ns_load_table(table_index, acpi_gbl_root_node);
 257         return status;
 258 }
 259
 260 ACPI_EXPORT_SYMBOL(acpi_load_table)
 261
 262 /*******************************************************************************
 263  *
 264  * FUNCTION:    acpi_get_table_header
 265  *
 266  * PARAMETERS:  Signature           - ACPI signature of needed table
 267  *              Instance            - Which instance (for SSDTs)
 268  *              out_table_header    - The pointer to the table header to fill
 269  *
 270  * RETURN:      Status and pointer to mapped table header
 271  *
 272  * DESCRIPTION: Finds an ACPI table header.
 273  *
 274  * NOTE:        Caller is responsible in unmapping the header with
 275  *              acpi_os_unmap_memory
 276  *
 277  ******************************************************************************/
 278 acpi_status
 279 acpi_get_table_header(char *signature,
 280                       u32 instance, struct acpi_table_header *out_table_header)
 281 {
 282        u32 i;
 283        u32 j;
 284         struct acpi_table_header *header;
 285
 286         /* Parameter validation */
 287
 288         if (!signature || !out_table_header) {
 289                 return (AE_BAD_PARAMETER);
 290         }
 291
 292         /* Walk the root table list */
 293
 294         for (i = 0, j = 0; i < acpi_gbl_root_table_list.count; i++) {
 295                 if (!ACPI_COMPARE_NAME
 296                     (&(acpi_gbl_root_table_list.tables[i].signature),
 297                      signature)) {
 298                         continue;
 299                 }
 300
 301                 if (++j < instance) {
 302                         continue;
 303                 }
 304
 305                 if (!acpi_gbl_root_table_list.tables[i].pointer) {
 306                         if ((acpi_gbl_root_table_list.tables[i].flags &
 307                              ACPI_TABLE_ORIGIN_MASK) ==
 308                             ACPI_TABLE_ORIGIN_MAPPED) {
 309                                 header =
 310                                     acpi_os_map_memory(acpi_gbl_root_table_list.
 311                                                        tables[i].address,
 312                                                        sizeof(struct
 313                                                               acpi_table_header));
 314                                 if (!header) {
 315                                         return AE_NO_MEMORY;
 316                                 }
 317                                 ACPI_MEMCPY(out_table_header, header,
 318                                             sizeof(struct acpi_table_header));
 319                                 acpi_os_unmap_memory(header,
 320                                                      sizeof(struct
 321                                                             acpi_table_header));
 322                         } else {
 323                                 return AE_NOT_FOUND;
 324                         }
 325                 } else {
 326                         ACPI_MEMCPY(out_table_header,
 327                                     acpi_gbl_root_table_list.tables[i].pointer,
 328                                     sizeof(struct acpi_table_header));
 329                 }
 330                 return (AE_OK);
 331         }
 332
 333         return (AE_NOT_FOUND);
 334 }
 335
 336 ACPI_EXPORT_SYMBOL(acpi_get_table_header)
 337
 338 /*******************************************************************************
 339  *
 340  * FUNCTION:    acpi_unload_table_id
 341  *
 342  * PARAMETERS:  id            - Owner ID of the table to be removed.
 343  *
 344  * RETURN:      Status
 345  *
 346  * DESCRIPTION: This routine is used to force the unload of a table (by id)
 347  *
 348  ******************************************************************************/
 349 acpi_status acpi_unload_table_id(acpi_owner_id id)
 350 {
 351         int i;
 352         acpi_status status = AE_NOT_EXIST;
 353
 354         ACPI_FUNCTION_TRACE(acpi_unload_table_id);
 355
 356         /* Find table in the global table list */
 357         for (i = 0; i < acpi_gbl_root_table_list.count; ++i) {
 358                 if (id != acpi_gbl_root_table_list.tables[i].owner_id) {
 359                         continue;
 360                 }
 361                 /*
 362                  * Delete all namespace objects owned by this table. Note that these
 363                  * objects can appear anywhere in the namespace by virtue of the AML
 364                  * "Scope" operator. Thus, we need to track ownership by an ID, not
 365                  * simply a position within the hierarchy
 366                  */
 367                 acpi_tb_delete_namespace_by_owner(i);
 368                 status = acpi_tb_release_owner_id(i);
 369                 acpi_tb_set_table_loaded_flag(i, FALSE);
 370                 break;
 371         }
 372         return_ACPI_STATUS(status);
 373 }
 374
 375 ACPI_EXPORT_SYMBOL(acpi_unload_table_id)
 376
 377 /*******************************************************************************
 378  *
 379  * FUNCTION:    acpi_get_table_with_size
 380  *
 381  * PARAMETERS:  Signature           - ACPI signature of needed table
 382  *              Instance            - Which instance (for SSDTs)
 383  *              out_table           - Where the pointer to the table is returned
 384  *
 385  * RETURN:      Status and pointer to table
 386  *
 387  * DESCRIPTION: Finds and verifies an ACPI table.
 388  *
 389  ******************************************************************************/
 390 acpi_status
 391 acpi_get_table_with_size(char *signature,
 392                u32 instance, struct acpi_table_header **out_table,
 393                acpi_size *tbl_size)
 394 {
 395        u32 i;
 396        u32 j;
 397         acpi_status status;
 398
 399         /* Parameter validation */
 400
 401         if (!signature || !out_table) {
 402                 return (AE_BAD_PARAMETER);
 403         }
 404
 405         /* Walk the root table list */
 406
 407         for (i = 0, j = 0; i < acpi_gbl_root_table_list.count; i++) {
 408                 if (!ACPI_COMPARE_NAME
 409                     (&(acpi_gbl_root_table_list.tables[i].signature),
 410                      signature)) {
 411                         continue;
 412                 }
 413
 414                 if (++j < instance) {
 415                         continue;
 416                 }
 417
 418                 status =
 419                     acpi_tb_verify_table(&acpi_gbl_root_table_list.tables[i]);
 420                 if (ACPI_SUCCESS(status)) {
 421                         *out_table = acpi_gbl_root_table_list.tables[i].pointer;
 422                         *tbl_size = acpi_gbl_root_table_list.tables[i].length;
 423                 }
 424
 425                 if (!acpi_gbl_permanent_mmap) {
 426                         acpi_gbl_root_table_list.tables[i].pointer = NULL;
 427                 }
 428
 429                 return (status);
 430         }
 431
 432         return (AE_NOT_FOUND);
 433 }
 434
 435 acpi_status
 436 acpi_get_table(char *signature,
 437                u32 instance, struct acpi_table_header **out_table)
 438 {
 439         acpi_size tbl_size;
 440
 441         return acpi_get_table_with_size(signature,
 442                        instance, out_table, &tbl_size);
 443 }
 444 ACPI_EXPORT_SYMBOL(acpi_get_table)
 445
 446 /*******************************************************************************
 447  *
 448  * FUNCTION:    acpi_get_table_by_index
 449  *
 450  * PARAMETERS:  table_index         - Table index
 451  *              Table               - Where the pointer to the table is returned
 452  *
 453  * RETURN:      Status and pointer to the table
 454  *
 455  * DESCRIPTION: Obtain a table by an index into the global table list.
 456  *
 457  ******************************************************************************/
 458 acpi_status
 459 acpi_get_table_by_index(u32 table_index, struct acpi_table_header **table)
 460 {
 461         acpi_status status;
 462
 463         ACPI_FUNCTION_TRACE(acpi_get_table_by_index);
 464
 465         /* Parameter validation */
 466
 467         if (!table) {
 468                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 469         }
 470
 471         (void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
 472
 473         /* Validate index */
 474
 475         if (table_index >= acpi_gbl_root_table_list.count) {
 476                 (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
 477                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 478         }
 479
 480         if (!acpi_gbl_root_table_list.tables[table_index].pointer) {
 481
 482                 /* Table is not mapped, map it */
 483
 484                 status =
 485                     acpi_tb_verify_table(&acpi_gbl_root_table_list.
 486                                          tables[table_index]);
 487                 if (ACPI_FAILURE(status)) {
 488                         (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
 489                         return_ACPI_STATUS(status);
 490                 }
 491         }
 492
 493         *table = acpi_gbl_root_table_list.tables[table_index].pointer;
 494         (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
 495         return_ACPI_STATUS(AE_OK);
 496 }
 497
 498 ACPI_EXPORT_SYMBOL(acpi_get_table_by_index)
 499
 500 /*******************************************************************************
 501  *
 502  * FUNCTION:    acpi_tb_load_namespace
 503  *
 504  * PARAMETERS:  None
 505  *
 506  * RETURN:      Status
 507  *
 508  * DESCRIPTION: Load the namespace from the DSDT and all SSDTs/PSDTs found in
 509  *              the RSDT/XSDT.
 510  *
 511  ******************************************************************************/
 512 static acpi_status acpi_tb_load_namespace(void)
 513 {
 514         acpi_status status;
 515         u32 i;
 516
 517         ACPI_FUNCTION_TRACE(tb_load_namespace);
 518
 519         (void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
 520
 521         acpi_gbl_DSDT = &acpi_gbl_root_table_list.tables[ACPI_TABLE_INDEX_DSDT];
 522
 523         /*
 524          * Load the namespace. The DSDT is required, but any SSDT and
 525          * PSDT tables are optional. Verify the DSDT.
 526          */
 527         if (!acpi_gbl_root_table_list.count ||
 528             !ACPI_COMPARE_NAME(&acpi_gbl_DSDT->signature, ACPI_SIG_DSDT) ||
 529             ACPI_FAILURE(acpi_tb_verify_table(acpi_gbl_DSDT))) {
 530                 status = AE_NO_ACPI_TABLES;
 531                 goto unlock_and_exit;
 532         }
 533
 534         /*
 535          * Save the original DSDT header for detection of table corruption
 536          * and/or replacement of the DSDT from outside the OS.
 537          */
 538         ACPI_MEMCPY(&acpi_gbl_original_dsdt_header, acpi_gbl_DSDT->pointer,
 539                     sizeof(struct acpi_table_header));
 540
 541         (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
 542
 543         /* Load and parse tables */
 544
 545         status = acpi_ns_load_table(ACPI_TABLE_INDEX_DSDT, acpi_gbl_root_node);
 546         if (ACPI_FAILURE(status)) {
 547                 return_ACPI_STATUS(status);
 548         }
 549
 550         /* Load any SSDT or PSDT tables. Note: Loop leaves tables locked */
 551
 552         (void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
 553         for (i = 0; i < acpi_gbl_root_table_list.count; ++i) {
 554                 if ((!ACPI_COMPARE_NAME
 555                      (&(acpi_gbl_root_table_list.tables[i].signature),
 556                       ACPI_SIG_SSDT)
 557                      &&
 558                      !ACPI_COMPARE_NAME(&
 559                                         (acpi_gbl_root_table_list.tables[i].
 560                                          signature), ACPI_SIG_PSDT))
 561                     ||
 562                     ACPI_FAILURE(acpi_tb_verify_table
 563                                  (&acpi_gbl_root_table_list.tables[i]))) {
 564                         continue;
 565                 }
 566
 567                 if (no_auto_ssdt) {
 568                         printk(KERN_WARNING "ACPI: SSDT ignored due to \"acpi_no_auto_ssdt\"\n");
 569                         continue;
 570                 }
 571
 572                 /* Ignore errors while loading tables, get as many as possible */
 573
 574                 (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
 575                 (void)acpi_ns_load_table(i, acpi_gbl_root_node);
 576                 (void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
 577         }
 578
 579         ACPI_DEBUG_PRINT((ACPI_DB_INIT, "ACPI Tables successfully acquired\n"));
 580
 581       unlock_and_exit:
 582         (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
 583         return_ACPI_STATUS(status);
 584 }
 585
 586 /*******************************************************************************
 587  *
 588  * FUNCTION:    acpi_load_tables
 589  *
 590  * PARAMETERS:  None
 591  *
 592  * RETURN:      Status
 593  *
 594  * DESCRIPTION: Load the ACPI tables from the RSDT/XSDT
 595  *
 596  ******************************************************************************/
 597
 598 acpi_status acpi_load_tables(void)
 599 {
 600         acpi_status status;
 601
 602         ACPI_FUNCTION_TRACE(acpi_load_tables);
 603
 604         /* Load the namespace from the tables */
 605
 606         status = acpi_tb_load_namespace();
 607         if (ACPI_FAILURE(status)) {
 608                 ACPI_EXCEPTION((AE_INFO, status,
 609                                 "While loading namespace from ACPI tables"));
 610         }
 611
 612         return_ACPI_STATUS(status);
 613 }
 614
 615 ACPI_EXPORT_SYMBOL(acpi_load_tables)
 616
 617
 618 /*******************************************************************************
 619  *
 620  * FUNCTION:    acpi_install_table_handler
 621  *
 622  * PARAMETERS:  Handler         - Table event handler
 623  *              Context         - Value passed to the handler on each event
 624  *
 625  * RETURN:      Status
 626  *
 627  * DESCRIPTION: Install table event handler
 628  *
 629  ******************************************************************************/
 630 acpi_status
 631 acpi_install_table_handler(acpi_tbl_handler handler, void *context)
 632 {
 633         acpi_status status;
 634
 635         ACPI_FUNCTION_TRACE(acpi_install_table_handler);
 636
 637         if (!handler) {
 638                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 639         }
 640
 641         status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
 642         if (ACPI_FAILURE(status)) {
 643                 return_ACPI_STATUS(status);
 644         }
 645
 646         /* Don't allow more than one handler */
 647
 648         if (acpi_gbl_table_handler) {
 649                 status = AE_ALREADY_EXISTS;
 650                 goto cleanup;
 651         }
 652
 653         /* Install the handler */
 654
 655         acpi_gbl_table_handler = handler;
 656         acpi_gbl_table_handler_context = context;
 657
 658       cleanup:
 659         (void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
 660         return_ACPI_STATUS(status);
 661 }
 662
 663 ACPI_EXPORT_SYMBOL(acpi_install_table_handler)
 664
 665 /*******************************************************************************
 666  *
 667  * FUNCTION:    acpi_remove_table_handler
 668  *
 669  * PARAMETERS:  Handler         - Table event handler that was installed
 670  *                                previously.
 671  *
 672  * RETURN:      Status
 673  *
 674  * DESCRIPTION: Remove table event handler
 675  *
 676  ******************************************************************************/
 677 acpi_status acpi_remove_table_handler(acpi_tbl_handler handler)
 678 {
 679         acpi_status status;
 680
 681         ACPI_FUNCTION_TRACE(acpi_remove_table_handler);
 682
 683         status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
 684         if (ACPI_FAILURE(status)) {
 685                 return_ACPI_STATUS(status);
 686         }
 687
 688         /* Make sure that the installed handler is the same */
 689
 690         if (!handler || handler != acpi_gbl_table_handler) {
 691                 status = AE_BAD_PARAMETER;
 692                 goto cleanup;
 693         }
 694
 695         /* Remove the handler */
 696
 697         acpi_gbl_table_handler = NULL;
 698
 699       cleanup:
 700         (void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
 701         return_ACPI_STATUS(status);
 702 }
 703
 704 ACPI_EXPORT_SYMBOL(acpi_remove_table_handler)
 705
 706
 707 static int __init acpi_no_auto_ssdt_setup(char *s) {
 708
 709         printk(KERN_NOTICE "ACPI: SSDT auto-load disabled\n");
 710
 711         no_auto_ssdt = 1;
 712
 713         return 1;
 714 }
 715
 716 __setup("acpi_no_auto_ssdt", acpi_no_auto_ssdt_setup);