ACPI, ia64: Use SRAT table rev to use 8bit or 16/32bit PXM fields (ia64)
[sfrench/cifs-2.6.git] / 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 - 2011, 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 <linux/export.h>
46 #include <acpi/acpi.h>
47 #include "accommon.h"
48 #include "acnamesp.h"
49 #include "actables.h"
50
51 #define _COMPONENT          ACPI_TABLES
52 ACPI_MODULE_NAME("tbxface")
53
54 /* Local prototypes */
55 static acpi_status acpi_tb_load_namespace(void);
56
57 static int no_auto_ssdt;
58
59 /*******************************************************************************
60  *
61  * FUNCTION:    acpi_allocate_root_table
62  *
63  * PARAMETERS:  initial_table_count - Size of initial_table_array, in number of
64  *                                    struct acpi_table_desc structures
65  *
66  * RETURN:      Status
67  *
68  * DESCRIPTION: Allocate a root table array. Used by i_aSL compiler and
69  *              acpi_initialize_tables.
70  *
71  ******************************************************************************/
72
73 acpi_status acpi_allocate_root_table(u32 initial_table_count)
74 {
75
76         acpi_gbl_root_table_list.max_table_count = initial_table_count;
77         acpi_gbl_root_table_list.flags = ACPI_ROOT_ALLOW_RESIZE;
78
79         return (acpi_tb_resize_root_table_list());
80 }
81
82 /*******************************************************************************
83  *
84  * FUNCTION:    acpi_initialize_tables
85  *
86  * PARAMETERS:  initial_table_array - Pointer to an array of pre-allocated
87  *                                    struct acpi_table_desc structures. If NULL, the
88  *                                    array is dynamically allocated.
89  *              initial_table_count - Size of initial_table_array, in number of
90  *                                    struct acpi_table_desc structures
91  *              allow_realloc       - Flag to tell Table Manager if resize of
92  *                                    pre-allocated array is allowed. Ignored
93  *                                    if initial_table_array is NULL.
94  *
95  * RETURN:      Status
96  *
97  * DESCRIPTION: Initialize the table manager, get the RSDP and RSDT/XSDT.
98  *
99  * NOTE:        Allows static allocation of the initial table array in order
100  *              to avoid the use of dynamic memory in confined environments
101  *              such as the kernel boot sequence where it may not be available.
102  *
103  *              If the host OS memory managers are initialized, use NULL for
104  *              initial_table_array, and the table will be dynamically allocated.
105  *
106  ******************************************************************************/
107
108 acpi_status __init
109 acpi_initialize_tables(struct acpi_table_desc * initial_table_array,
110                        u32 initial_table_count, u8 allow_resize)
111 {
112         acpi_physical_address rsdp_address;
113         acpi_status status;
114
115         ACPI_FUNCTION_TRACE(acpi_initialize_tables);
116
117         /*
118          * Set up the Root Table Array
119          * Allocate the table array if requested
120          */
121         if (!initial_table_array) {
122                 status = acpi_allocate_root_table(initial_table_count);
123                 if (ACPI_FAILURE(status)) {
124                         return_ACPI_STATUS(status);
125                 }
126         } else {
127                 /* Root Table Array has been statically allocated by the host */
128
129                 ACPI_MEMSET(initial_table_array, 0,
130                             (acpi_size) initial_table_count *
131                             sizeof(struct acpi_table_desc));
132
133                 acpi_gbl_root_table_list.tables = initial_table_array;
134                 acpi_gbl_root_table_list.max_table_count = initial_table_count;
135                 acpi_gbl_root_table_list.flags = ACPI_ROOT_ORIGIN_UNKNOWN;
136                 if (allow_resize) {
137                         acpi_gbl_root_table_list.flags |=
138                             ACPI_ROOT_ALLOW_RESIZE;
139                 }
140         }
141
142         /* Get the address of the RSDP */
143
144         rsdp_address = acpi_os_get_root_pointer();
145         if (!rsdp_address) {
146                 return_ACPI_STATUS(AE_NOT_FOUND);
147         }
148
149         /*
150          * Get the root table (RSDT or XSDT) and extract all entries to the local
151          * Root Table Array. This array contains the information of the RSDT/XSDT
152          * in a common, more useable format.
153          */
154         status = acpi_tb_parse_root_table(rsdp_address);
155         return_ACPI_STATUS(status);
156 }
157
158 /*******************************************************************************
159  *
160  * FUNCTION:    acpi_reallocate_root_table
161  *
162  * PARAMETERS:  None
163  *
164  * RETURN:      Status
165  *
166  * DESCRIPTION: Reallocate Root Table List into dynamic memory. Copies the
167  *              root list from the previously provided scratch area. Should
168  *              be called once dynamic memory allocation is available in the
169  *              kernel
170  *
171  ******************************************************************************/
172 acpi_status acpi_reallocate_root_table(void)
173 {
174         struct acpi_table_desc *tables;
175         acpi_size new_size;
176         acpi_size current_size;
177
178         ACPI_FUNCTION_TRACE(acpi_reallocate_root_table);
179
180         /*
181          * Only reallocate the root table if the host provided a static buffer
182          * for the table array in the call to acpi_initialize_tables.
183          */
184         if (acpi_gbl_root_table_list.flags & ACPI_ROOT_ORIGIN_ALLOCATED) {
185                 return_ACPI_STATUS(AE_SUPPORT);
186         }
187
188         /*
189          * Get the current size of the root table and add the default
190          * increment to create the new table size.
191          */
192         current_size = (acpi_size)
193             acpi_gbl_root_table_list.current_table_count *
194             sizeof(struct acpi_table_desc);
195
196         new_size = current_size +
197             (ACPI_ROOT_TABLE_SIZE_INCREMENT * sizeof(struct acpi_table_desc));
198
199         /* Create new array and copy the old array */
200
201         tables = ACPI_ALLOCATE_ZEROED(new_size);
202         if (!tables) {
203                 return_ACPI_STATUS(AE_NO_MEMORY);
204         }
205
206         ACPI_MEMCPY(tables, acpi_gbl_root_table_list.tables, current_size);
207
208         /*
209          * Update the root table descriptor. The new size will be the current
210          * number of tables plus the increment, independent of the reserved
211          * size of the original table list.
212          */
213         acpi_gbl_root_table_list.tables = tables;
214         acpi_gbl_root_table_list.max_table_count =
215             acpi_gbl_root_table_list.current_table_count +
216             ACPI_ROOT_TABLE_SIZE_INCREMENT;
217         acpi_gbl_root_table_list.flags =
218             ACPI_ROOT_ORIGIN_ALLOCATED | ACPI_ROOT_ALLOW_RESIZE;
219
220         return_ACPI_STATUS(AE_OK);
221 }
222
223 /*******************************************************************************
224  *
225  * FUNCTION:    acpi_load_table
226  *
227  * PARAMETERS:  table_ptr       - pointer to a buffer containing the entire
228  *                                table to be loaded
229  *
230  * RETURN:      Status
231  *
232  * DESCRIPTION: This function is called to load a table from the caller's
233  *              buffer. The buffer must contain an entire ACPI Table including
234  *              a valid header. The header fields will be verified, and if it
235  *              is determined that the table is invalid, the call will fail.
236  *
237  ******************************************************************************/
238 acpi_status acpi_load_table(struct acpi_table_header *table_ptr)
239 {
240         acpi_status status;
241         u32 table_index;
242         struct acpi_table_desc table_desc;
243
244         if (!table_ptr)
245                 return AE_BAD_PARAMETER;
246
247         ACPI_MEMSET(&table_desc, 0, sizeof(struct acpi_table_desc));
248         table_desc.pointer = table_ptr;
249         table_desc.length = table_ptr->length;
250         table_desc.flags = ACPI_TABLE_ORIGIN_UNKNOWN;
251
252         /*
253          * Install the new table into the local data structures
254          */
255         status = acpi_tb_add_table(&table_desc, &table_index);
256         if (ACPI_FAILURE(status)) {
257                 return status;
258         }
259         status = acpi_ns_load_table(table_index, acpi_gbl_root_node);
260         return status;
261 }
262
263 ACPI_EXPORT_SYMBOL(acpi_load_table)
264
265 /*******************************************************************************
266  *
267  * FUNCTION:    acpi_get_table_header
268  *
269  * PARAMETERS:  Signature           - ACPI signature of needed table
270  *              Instance            - Which instance (for SSDTs)
271  *              out_table_header    - The pointer to the table header to fill
272  *
273  * RETURN:      Status and pointer to mapped table header
274  *
275  * DESCRIPTION: Finds an ACPI table header.
276  *
277  * NOTE:        Caller is responsible in unmapping the header with
278  *              acpi_os_unmap_memory
279  *
280  ******************************************************************************/
281 acpi_status
282 acpi_get_table_header(char *signature,
283                       u32 instance, struct acpi_table_header *out_table_header)
284 {
285        u32 i;
286        u32 j;
287         struct acpi_table_header *header;
288
289         /* Parameter validation */
290
291         if (!signature || !out_table_header) {
292                 return (AE_BAD_PARAMETER);
293         }
294
295         /* Walk the root table list */
296
297         for (i = 0, j = 0; i < acpi_gbl_root_table_list.current_table_count;
298              i++) {
299                 if (!ACPI_COMPARE_NAME
300                     (&(acpi_gbl_root_table_list.tables[i].signature),
301                      signature)) {
302                         continue;
303                 }
304
305                 if (++j < instance) {
306                         continue;
307                 }
308
309                 if (!acpi_gbl_root_table_list.tables[i].pointer) {
310                         if ((acpi_gbl_root_table_list.tables[i].flags &
311                              ACPI_TABLE_ORIGIN_MASK) ==
312                             ACPI_TABLE_ORIGIN_MAPPED) {
313                                 header =
314                                     acpi_os_map_memory(acpi_gbl_root_table_list.
315                                                        tables[i].address,
316                                                        sizeof(struct
317                                                               acpi_table_header));
318                                 if (!header) {
319                                         return AE_NO_MEMORY;
320                                 }
321                                 ACPI_MEMCPY(out_table_header, header,
322                                             sizeof(struct acpi_table_header));
323                                 acpi_os_unmap_memory(header,
324                                                      sizeof(struct
325                                                             acpi_table_header));
326                         } else {
327                                 return AE_NOT_FOUND;
328                         }
329                 } else {
330                         ACPI_MEMCPY(out_table_header,
331                                     acpi_gbl_root_table_list.tables[i].pointer,
332                                     sizeof(struct acpi_table_header));
333                 }
334                 return (AE_OK);
335         }
336
337         return (AE_NOT_FOUND);
338 }
339
340 ACPI_EXPORT_SYMBOL(acpi_get_table_header)
341
342 /*******************************************************************************
343  *
344  * FUNCTION:    acpi_unload_table_id
345  *
346  * PARAMETERS:  id            - Owner ID of the table to be removed.
347  *
348  * RETURN:      Status
349  *
350  * DESCRIPTION: This routine is used to force the unload of a table (by id)
351  *
352  ******************************************************************************/
353 acpi_status acpi_unload_table_id(acpi_owner_id id)
354 {
355         int i;
356         acpi_status status = AE_NOT_EXIST;
357
358         ACPI_FUNCTION_TRACE(acpi_unload_table_id);
359
360         /* Find table in the global table list */
361         for (i = 0; i < acpi_gbl_root_table_list.current_table_count; ++i) {
362                 if (id != acpi_gbl_root_table_list.tables[i].owner_id) {
363                         continue;
364                 }
365                 /*
366                  * Delete all namespace objects owned by this table. Note that these
367                  * objects can appear anywhere in the namespace by virtue of the AML
368                  * "Scope" operator. Thus, we need to track ownership by an ID, not
369                  * simply a position within the hierarchy
370                  */
371                 acpi_tb_delete_namespace_by_owner(i);
372                 status = acpi_tb_release_owner_id(i);
373                 acpi_tb_set_table_loaded_flag(i, FALSE);
374                 break;
375         }
376         return_ACPI_STATUS(status);
377 }
378
379 ACPI_EXPORT_SYMBOL(acpi_unload_table_id)
380
381 /*******************************************************************************
382  *
383  * FUNCTION:    acpi_get_table_with_size
384  *
385  * PARAMETERS:  Signature           - ACPI signature of needed table
386  *              Instance            - Which instance (for SSDTs)
387  *              out_table           - Where the pointer to the table is returned
388  *
389  * RETURN:      Status and pointer to table
390  *
391  * DESCRIPTION: Finds and verifies an ACPI table.
392  *
393  ******************************************************************************/
394 acpi_status
395 acpi_get_table_with_size(char *signature,
396                u32 instance, struct acpi_table_header **out_table,
397                acpi_size *tbl_size)
398 {
399        u32 i;
400        u32 j;
401         acpi_status status;
402
403         /* Parameter validation */
404
405         if (!signature || !out_table) {
406                 return (AE_BAD_PARAMETER);
407         }
408
409         /* Walk the root table list */
410
411         for (i = 0, j = 0; i < acpi_gbl_root_table_list.current_table_count;
412              i++) {
413                 if (!ACPI_COMPARE_NAME
414                     (&(acpi_gbl_root_table_list.tables[i].signature),
415                      signature)) {
416                         continue;
417                 }
418
419                 if (++j < instance) {
420                         continue;
421                 }
422
423                 status =
424                     acpi_tb_verify_table(&acpi_gbl_root_table_list.tables[i]);
425                 if (ACPI_SUCCESS(status)) {
426                         *out_table = acpi_gbl_root_table_list.tables[i].pointer;
427                         *tbl_size = acpi_gbl_root_table_list.tables[i].length;
428                 }
429
430                 if (!acpi_gbl_permanent_mmap) {
431                         acpi_gbl_root_table_list.tables[i].pointer = NULL;
432                 }
433
434                 return (status);
435         }
436
437         return (AE_NOT_FOUND);
438 }
439
440 acpi_status
441 acpi_get_table(char *signature,
442                u32 instance, struct acpi_table_header **out_table)
443 {
444         acpi_size tbl_size;
445
446         return acpi_get_table_with_size(signature,
447                        instance, out_table, &tbl_size);
448 }
449 ACPI_EXPORT_SYMBOL(acpi_get_table)
450
451 /*******************************************************************************
452  *
453  * FUNCTION:    acpi_get_table_by_index
454  *
455  * PARAMETERS:  table_index         - Table index
456  *              Table               - Where the pointer to the table is returned
457  *
458  * RETURN:      Status and pointer to the table
459  *
460  * DESCRIPTION: Obtain a table by an index into the global table list.
461  *
462  ******************************************************************************/
463 acpi_status
464 acpi_get_table_by_index(u32 table_index, struct acpi_table_header **table)
465 {
466         acpi_status status;
467
468         ACPI_FUNCTION_TRACE(acpi_get_table_by_index);
469
470         /* Parameter validation */
471
472         if (!table) {
473                 return_ACPI_STATUS(AE_BAD_PARAMETER);
474         }
475
476         (void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
477
478         /* Validate index */
479
480         if (table_index >= acpi_gbl_root_table_list.current_table_count) {
481                 (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
482                 return_ACPI_STATUS(AE_BAD_PARAMETER);
483         }
484
485         if (!acpi_gbl_root_table_list.tables[table_index].pointer) {
486
487                 /* Table is not mapped, map it */
488
489                 status =
490                     acpi_tb_verify_table(&acpi_gbl_root_table_list.
491                                          tables[table_index]);
492                 if (ACPI_FAILURE(status)) {
493                         (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
494                         return_ACPI_STATUS(status);
495                 }
496         }
497
498         *table = acpi_gbl_root_table_list.tables[table_index].pointer;
499         (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
500         return_ACPI_STATUS(AE_OK);
501 }
502
503 ACPI_EXPORT_SYMBOL(acpi_get_table_by_index)
504
505 /*******************************************************************************
506  *
507  * FUNCTION:    acpi_tb_load_namespace
508  *
509  * PARAMETERS:  None
510  *
511  * RETURN:      Status
512  *
513  * DESCRIPTION: Load the namespace from the DSDT and all SSDTs/PSDTs found in
514  *              the RSDT/XSDT.
515  *
516  ******************************************************************************/
517 static acpi_status acpi_tb_load_namespace(void)
518 {
519         acpi_status status;
520         u32 i;
521         struct acpi_table_header *new_dsdt;
522
523         ACPI_FUNCTION_TRACE(tb_load_namespace);
524
525         (void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
526
527         /*
528          * Load the namespace. The DSDT is required, but any SSDT and
529          * PSDT tables are optional. Verify the DSDT.
530          */
531         if (!acpi_gbl_root_table_list.current_table_count ||
532             !ACPI_COMPARE_NAME(&
533                                (acpi_gbl_root_table_list.
534                                 tables[ACPI_TABLE_INDEX_DSDT].signature),
535                                ACPI_SIG_DSDT)
536             ||
537             ACPI_FAILURE(acpi_tb_verify_table
538                          (&acpi_gbl_root_table_list.
539                           tables[ACPI_TABLE_INDEX_DSDT]))) {
540                 status = AE_NO_ACPI_TABLES;
541                 goto unlock_and_exit;
542         }
543
544         /*
545          * Save the DSDT pointer for simple access. This is the mapped memory
546          * address. We must take care here because the address of the .Tables
547          * array can change dynamically as tables are loaded at run-time. Note:
548          * .Pointer field is not validated until after call to acpi_tb_verify_table.
549          */
550         acpi_gbl_DSDT =
551             acpi_gbl_root_table_list.tables[ACPI_TABLE_INDEX_DSDT].pointer;
552
553         /*
554          * Optionally copy the entire DSDT to local memory (instead of simply
555          * mapping it.) There are some BIOSs that corrupt or replace the original
556          * DSDT, creating the need for this option. Default is FALSE, do not copy
557          * the DSDT.
558          */
559         if (acpi_gbl_copy_dsdt_locally) {
560                 new_dsdt = acpi_tb_copy_dsdt(ACPI_TABLE_INDEX_DSDT);
561                 if (new_dsdt) {
562                         acpi_gbl_DSDT = new_dsdt;
563                 }
564         }
565
566         /*
567          * Save the original DSDT header for detection of table corruption
568          * and/or replacement of the DSDT from outside the OS.
569          */
570         ACPI_MEMCPY(&acpi_gbl_original_dsdt_header, acpi_gbl_DSDT,
571                     sizeof(struct acpi_table_header));
572
573         (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
574
575         /* Load and parse tables */
576
577         status = acpi_ns_load_table(ACPI_TABLE_INDEX_DSDT, acpi_gbl_root_node);
578         if (ACPI_FAILURE(status)) {
579                 return_ACPI_STATUS(status);
580         }
581
582         /* Load any SSDT or PSDT tables. Note: Loop leaves tables locked */
583
584         (void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
585         for (i = 0; i < acpi_gbl_root_table_list.current_table_count; ++i) {
586                 if ((!ACPI_COMPARE_NAME
587                      (&(acpi_gbl_root_table_list.tables[i].signature),
588                       ACPI_SIG_SSDT)
589                      &&
590                      !ACPI_COMPARE_NAME(&
591                                         (acpi_gbl_root_table_list.tables[i].
592                                          signature), ACPI_SIG_PSDT))
593                     ||
594                     ACPI_FAILURE(acpi_tb_verify_table
595                                  (&acpi_gbl_root_table_list.tables[i]))) {
596                         continue;
597                 }
598
599                 if (no_auto_ssdt) {
600                         printk(KERN_WARNING "ACPI: SSDT ignored due to \"acpi_no_auto_ssdt\"\n");
601                         continue;
602                 }
603
604                 /* Ignore errors while loading tables, get as many as possible */
605
606                 (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
607                 (void)acpi_ns_load_table(i, acpi_gbl_root_node);
608                 (void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
609         }
610
611         ACPI_DEBUG_PRINT((ACPI_DB_INIT, "ACPI Tables successfully acquired\n"));
612
613       unlock_and_exit:
614         (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
615         return_ACPI_STATUS(status);
616 }
617
618 /*******************************************************************************
619  *
620  * FUNCTION:    acpi_load_tables
621  *
622  * PARAMETERS:  None
623  *
624  * RETURN:      Status
625  *
626  * DESCRIPTION: Load the ACPI tables from the RSDT/XSDT
627  *
628  ******************************************************************************/
629
630 acpi_status acpi_load_tables(void)
631 {
632         acpi_status status;
633
634         ACPI_FUNCTION_TRACE(acpi_load_tables);
635
636         /* Load the namespace from the tables */
637
638         status = acpi_tb_load_namespace();
639         if (ACPI_FAILURE(status)) {
640                 ACPI_EXCEPTION((AE_INFO, status,
641                                 "While loading namespace from ACPI tables"));
642         }
643
644         return_ACPI_STATUS(status);
645 }
646
647 ACPI_EXPORT_SYMBOL(acpi_load_tables)
648
649
650 /*******************************************************************************
651  *
652  * FUNCTION:    acpi_install_table_handler
653  *
654  * PARAMETERS:  Handler         - Table event handler
655  *              Context         - Value passed to the handler on each event
656  *
657  * RETURN:      Status
658  *
659  * DESCRIPTION: Install table event handler
660  *
661  ******************************************************************************/
662 acpi_status
663 acpi_install_table_handler(acpi_tbl_handler handler, void *context)
664 {
665         acpi_status status;
666
667         ACPI_FUNCTION_TRACE(acpi_install_table_handler);
668
669         if (!handler) {
670                 return_ACPI_STATUS(AE_BAD_PARAMETER);
671         }
672
673         status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
674         if (ACPI_FAILURE(status)) {
675                 return_ACPI_STATUS(status);
676         }
677
678         /* Don't allow more than one handler */
679
680         if (acpi_gbl_table_handler) {
681                 status = AE_ALREADY_EXISTS;
682                 goto cleanup;
683         }
684
685         /* Install the handler */
686
687         acpi_gbl_table_handler = handler;
688         acpi_gbl_table_handler_context = context;
689
690       cleanup:
691         (void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
692         return_ACPI_STATUS(status);
693 }
694
695 ACPI_EXPORT_SYMBOL(acpi_install_table_handler)
696
697 /*******************************************************************************
698  *
699  * FUNCTION:    acpi_remove_table_handler
700  *
701  * PARAMETERS:  Handler         - Table event handler that was installed
702  *                                previously.
703  *
704  * RETURN:      Status
705  *
706  * DESCRIPTION: Remove table event handler
707  *
708  ******************************************************************************/
709 acpi_status acpi_remove_table_handler(acpi_tbl_handler handler)
710 {
711         acpi_status status;
712
713         ACPI_FUNCTION_TRACE(acpi_remove_table_handler);
714
715         status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
716         if (ACPI_FAILURE(status)) {
717                 return_ACPI_STATUS(status);
718         }
719
720         /* Make sure that the installed handler is the same */
721
722         if (!handler || handler != acpi_gbl_table_handler) {
723                 status = AE_BAD_PARAMETER;
724                 goto cleanup;
725         }
726
727         /* Remove the handler */
728
729         acpi_gbl_table_handler = NULL;
730
731       cleanup:
732         (void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
733         return_ACPI_STATUS(status);
734 }
735
736 ACPI_EXPORT_SYMBOL(acpi_remove_table_handler)
737
738
739 static int __init acpi_no_auto_ssdt_setup(char *s) {
740
741         printk(KERN_NOTICE "ACPI: SSDT auto-load disabled\n");
742
743         no_auto_ssdt = 1;
744
745         return 1;
746 }
747
748 __setup("acpi_no_auto_ssdt", acpi_no_auto_ssdt_setup);