Merge branch 'irq-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
[linux-2.6] / drivers / acpi / tables / 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 <acpi/acnamesp.h>
47 #include <acpi/actables.h>
48
49 #define _COMPONENT          ACPI_TABLES
50 ACPI_MODULE_NAME("tbxface")
51
52 /* Local prototypes */
53 static acpi_status acpi_tb_load_namespace(void);
54
55 static int no_auto_ssdt;
56
57 /*******************************************************************************
58  *
59  * FUNCTION:    acpi_allocate_root_table
60  *
61  * PARAMETERS:  initial_table_count - Size of initial_table_array, in number of
62  *                                    struct acpi_table_desc structures
63  *
64  * RETURN:      Status
65  *
66  * DESCRIPTION: Allocate a root table array. Used by i_aSL compiler and
67  *              acpi_initialize_tables.
68  *
69  ******************************************************************************/
70
71 acpi_status acpi_allocate_root_table(u32 initial_table_count)
72 {
73
74         acpi_gbl_root_table_list.size = initial_table_count;
75         acpi_gbl_root_table_list.flags = ACPI_ROOT_ALLOW_RESIZE;
76
77         return (acpi_tb_resize_root_table_list());
78 }
79
80 /*******************************************************************************
81  *
82  * FUNCTION:    acpi_initialize_tables
83  *
84  * PARAMETERS:  initial_table_array - Pointer to an array of pre-allocated
85  *                                    struct acpi_table_desc structures. If NULL, the
86  *                                    array is dynamically allocated.
87  *              initial_table_count - Size of initial_table_array, in number of
88  *                                    struct acpi_table_desc structures
89  *              allow_realloc       - Flag to tell Table Manager if resize of
90  *                                    pre-allocated array is allowed. Ignored
91  *                                    if initial_table_array is NULL.
92  *
93  * RETURN:      Status
94  *
95  * DESCRIPTION: Initialize the table manager, get the RSDP and RSDT/XSDT.
96  *
97  * NOTE:        Allows static allocation of the initial table array in order
98  *              to avoid the use of dynamic memory in confined environments
99  *              such as the kernel boot sequence where it may not be available.
100  *
101  *              If the host OS memory managers are initialized, use NULL for
102  *              initial_table_array, and the table will be dynamically allocated.
103  *
104  ******************************************************************************/
105
106 acpi_status __init
107 acpi_initialize_tables(struct acpi_table_desc * initial_table_array,
108                        u32 initial_table_count, u8 allow_resize)
109 {
110         acpi_physical_address rsdp_address;
111         acpi_status status;
112
113         ACPI_FUNCTION_TRACE(acpi_initialize_tables);
114
115         /*
116          * Set up the Root Table Array
117          * Allocate the table array if requested
118          */
119         if (!initial_table_array) {
120                 status = acpi_allocate_root_table(initial_table_count);
121                 if (ACPI_FAILURE(status)) {
122                         return_ACPI_STATUS(status);
123                 }
124         } else {
125                 /* Root Table Array has been statically allocated by the host */
126
127                 ACPI_MEMSET(initial_table_array, 0,
128                             (acpi_size) initial_table_count *
129                             sizeof(struct acpi_table_desc));
130
131                 acpi_gbl_root_table_list.tables = initial_table_array;
132                 acpi_gbl_root_table_list.size = initial_table_count;
133                 acpi_gbl_root_table_list.flags = ACPI_ROOT_ORIGIN_UNKNOWN;
134                 if (allow_resize) {
135                         acpi_gbl_root_table_list.flags |=
136                             ACPI_ROOT_ALLOW_RESIZE;
137                 }
138         }
139
140         /* Get the address of the RSDP */
141
142         rsdp_address = acpi_os_get_root_pointer();
143         if (!rsdp_address) {
144                 return_ACPI_STATUS(AE_NOT_FOUND);
145         }
146
147         /*
148          * Get the root table (RSDT or XSDT) and extract all entries to the local
149          * Root Table Array. This array contains the information of the RSDT/XSDT
150          * in a common, more useable format.
151          */
152         status =
153             acpi_tb_parse_root_table(rsdp_address, ACPI_TABLE_ORIGIN_MAPPED);
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         /*
280          * Walk the root table list
281          */
282         for (i = 0, j = 0; i < acpi_gbl_root_table_list.count; i++) {
283                 if (!ACPI_COMPARE_NAME
284                     (&(acpi_gbl_root_table_list.tables[i].signature),
285                      signature)) {
286                         continue;
287                 }
288
289                 if (++j < instance) {
290                         continue;
291                 }
292
293                 if (!acpi_gbl_root_table_list.tables[i].pointer) {
294                         if ((acpi_gbl_root_table_list.tables[i].
295                              flags & ACPI_TABLE_ORIGIN_MASK) ==
296                             ACPI_TABLE_ORIGIN_MAPPED) {
297                                 header =
298                                     acpi_os_map_memory(acpi_gbl_root_table_list.
299                                                        tables[i].address,
300                                                        sizeof(struct
301                                                               acpi_table_header));
302                                 if (!header) {
303                                         return AE_NO_MEMORY;
304                                 }
305                                 ACPI_MEMCPY(out_table_header, header,
306                                             sizeof(struct acpi_table_header));
307                                 acpi_os_unmap_memory(header,
308                                                      sizeof(struct
309                                                             acpi_table_header));
310                         } else {
311                                 return AE_NOT_FOUND;
312                         }
313                 } else {
314                         ACPI_MEMCPY(out_table_header,
315                                     acpi_gbl_root_table_list.tables[i].pointer,
316                                     sizeof(struct acpi_table_header));
317                 }
318                 return (AE_OK);
319         }
320
321         return (AE_NOT_FOUND);
322 }
323
324 ACPI_EXPORT_SYMBOL(acpi_get_table_header)
325
326 /******************************************************************************
327  *
328  * FUNCTION:    acpi_unload_table_id
329  *
330  * PARAMETERS:  id            - Owner ID of the table to be removed.
331  *
332  * RETURN:      Status
333  *
334  * DESCRIPTION: This routine is used to force the unload of a table (by id)
335  *
336  ******************************************************************************/
337 acpi_status acpi_unload_table_id(acpi_owner_id id)
338 {
339         int i;
340         acpi_status status = AE_NOT_EXIST;
341
342         ACPI_FUNCTION_TRACE(acpi_unload_table_id);
343
344         /* Find table in the global table list */
345         for (i = 0; i < acpi_gbl_root_table_list.count; ++i) {
346                 if (id != acpi_gbl_root_table_list.tables[i].owner_id) {
347                         continue;
348                 }
349                 /*
350                  * Delete all namespace objects owned by this table. Note that these
351                  * objects can appear anywhere in the namespace by virtue of the AML
352                  * "Scope" operator. Thus, we need to track ownership by an ID, not
353                  * simply a position within the hierarchy
354                  */
355                 acpi_tb_delete_namespace_by_owner(i);
356                 status = acpi_tb_release_owner_id(i);
357                 acpi_tb_set_table_loaded_flag(i, FALSE);
358                 break;
359         }
360         return_ACPI_STATUS(status);
361 }
362
363 ACPI_EXPORT_SYMBOL(acpi_unload_table_id)
364
365 /*******************************************************************************
366  *
367  * FUNCTION:    acpi_get_table
368  *
369  * PARAMETERS:  Signature           - ACPI signature of needed table
370  *              Instance            - Which instance (for SSDTs)
371  *              out_table           - Where the pointer to the table is returned
372  *
373  * RETURN:      Status and pointer to table
374  *
375  * DESCRIPTION: Finds and verifies an ACPI table.
376  *
377  *****************************************************************************/
378 acpi_status
379 acpi_get_table(char *signature,
380                u32 instance, struct acpi_table_header **out_table)
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         /*
393          * Walk the root table list
394          */
395         for (i = 0, j = 0; i < acpi_gbl_root_table_list.count; i++) {
396                 if (!ACPI_COMPARE_NAME
397                     (&(acpi_gbl_root_table_list.tables[i].signature),
398                      signature)) {
399                         continue;
400                 }
401
402                 if (++j < instance) {
403                         continue;
404                 }
405
406                 status =
407                     acpi_tb_verify_table(&acpi_gbl_root_table_list.tables[i]);
408                 if (ACPI_SUCCESS(status)) {
409                         *out_table = acpi_gbl_root_table_list.tables[i].pointer;
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_EXPORT_SYMBOL(acpi_get_table)
423
424 /*******************************************************************************
425  *
426  * FUNCTION:    acpi_get_table_by_index
427  *
428  * PARAMETERS:  table_index         - Table index
429  *              Table               - Where the pointer to the table is returned
430  *
431  * RETURN:      Status and pointer to the table
432  *
433  * DESCRIPTION: Obtain a table by an index into the global table list.
434  *
435  ******************************************************************************/
436 acpi_status
437 acpi_get_table_by_index(u32 table_index, struct acpi_table_header **table)
438 {
439         acpi_status status;
440
441         ACPI_FUNCTION_TRACE(acpi_get_table_by_index);
442
443         /* Parameter validation */
444
445         if (!table) {
446                 return_ACPI_STATUS(AE_BAD_PARAMETER);
447         }
448
449         (void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
450
451         /* Validate index */
452
453         if (table_index >= acpi_gbl_root_table_list.count) {
454                 (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
455                 return_ACPI_STATUS(AE_BAD_PARAMETER);
456         }
457
458         if (!acpi_gbl_root_table_list.tables[table_index].pointer) {
459
460                 /* Table is not mapped, map it */
461
462                 status =
463                     acpi_tb_verify_table(&acpi_gbl_root_table_list.
464                                          tables[table_index]);
465                 if (ACPI_FAILURE(status)) {
466                         (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
467                         return_ACPI_STATUS(status);
468                 }
469         }
470
471         *table = acpi_gbl_root_table_list.tables[table_index].pointer;
472         (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
473         return_ACPI_STATUS(AE_OK);
474 }
475
476 ACPI_EXPORT_SYMBOL(acpi_get_table_by_index)
477
478 /*******************************************************************************
479  *
480  * FUNCTION:    acpi_tb_load_namespace
481  *
482  * PARAMETERS:  None
483  *
484  * RETURN:      Status
485  *
486  * DESCRIPTION: Load the namespace from the DSDT and all SSDTs/PSDTs found in
487  *              the RSDT/XSDT.
488  *
489  ******************************************************************************/
490 static acpi_status acpi_tb_load_namespace(void)
491 {
492         acpi_status status;
493         struct acpi_table_header *table;
494         u32 i;
495
496         ACPI_FUNCTION_TRACE(tb_load_namespace);
497
498         (void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
499
500         /*
501          * Load the namespace. The DSDT is required, but any SSDT and PSDT tables
502          * are optional.
503          */
504         if (!acpi_gbl_root_table_list.count ||
505             !ACPI_COMPARE_NAME(&
506                                (acpi_gbl_root_table_list.
507                                 tables[ACPI_TABLE_INDEX_DSDT].signature),
508                                ACPI_SIG_DSDT)
509             ||
510             ACPI_FAILURE(acpi_tb_verify_table
511                          (&acpi_gbl_root_table_list.
512                           tables[ACPI_TABLE_INDEX_DSDT]))) {
513                 status = AE_NO_ACPI_TABLES;
514                 goto unlock_and_exit;
515         }
516
517         /*
518          * Find DSDT table
519          */
520         status =
521             acpi_os_table_override(acpi_gbl_root_table_list.
522                                    tables[ACPI_TABLE_INDEX_DSDT].pointer,
523                                    &table);
524         if (ACPI_SUCCESS(status) && table) {
525                 /*
526                  * DSDT table has been found
527                  */
528                 acpi_tb_delete_table(&acpi_gbl_root_table_list.
529                                      tables[ACPI_TABLE_INDEX_DSDT]);
530                 acpi_gbl_root_table_list.tables[ACPI_TABLE_INDEX_DSDT].pointer =
531                     table;
532                 acpi_gbl_root_table_list.tables[ACPI_TABLE_INDEX_DSDT].length =
533                     table->length;
534                 acpi_gbl_root_table_list.tables[ACPI_TABLE_INDEX_DSDT].flags =
535                     ACPI_TABLE_ORIGIN_UNKNOWN;
536
537                 ACPI_INFO((AE_INFO, "Table DSDT replaced by host OS"));
538                 acpi_tb_print_table_header(0, table);
539
540                 if (no_auto_ssdt == 0) {
541                         printk(KERN_WARNING "ACPI: DSDT override uses original SSDTs unless \"acpi_no_auto_ssdt\"\n");
542                 }
543         }
544
545         status =
546             acpi_tb_verify_table(&acpi_gbl_root_table_list.
547                                  tables[ACPI_TABLE_INDEX_DSDT]);
548         if (ACPI_FAILURE(status)) {
549
550                 /* A valid DSDT is required */
551
552                 status = AE_NO_ACPI_TABLES;
553                 goto unlock_and_exit;
554         }
555
556         (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
557
558         /*
559          * Load and parse tables.
560          */
561         status = acpi_ns_load_table(ACPI_TABLE_INDEX_DSDT, acpi_gbl_root_node);
562         if (ACPI_FAILURE(status)) {
563                 return_ACPI_STATUS(status);
564         }
565
566         /*
567          * Load any SSDT or PSDT tables. Note: Loop leaves tables locked
568          */
569         (void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
570         for (i = 0; i < acpi_gbl_root_table_list.count; ++i) {
571                 if ((!ACPI_COMPARE_NAME
572                      (&(acpi_gbl_root_table_list.tables[i].signature),
573                       ACPI_SIG_SSDT)
574                      &&
575                      !ACPI_COMPARE_NAME(&
576                                         (acpi_gbl_root_table_list.tables[i].
577                                          signature), ACPI_SIG_PSDT))
578                     ||
579                     ACPI_FAILURE(acpi_tb_verify_table
580                                  (&acpi_gbl_root_table_list.tables[i]))) {
581                         continue;
582                 }
583
584                 if (no_auto_ssdt) {
585                         printk(KERN_WARNING "ACPI: SSDT ignored due to \"acpi_no_auto_ssdt\"\n");
586                         continue;
587                 }
588
589                 /* Ignore errors while loading tables, get as many as possible */
590
591                 (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
592                 (void)acpi_ns_load_table(i, acpi_gbl_root_node);
593                 (void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
594         }
595
596         ACPI_DEBUG_PRINT((ACPI_DB_INIT, "ACPI Tables successfully acquired\n"));
597
598       unlock_and_exit:
599         (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
600         return_ACPI_STATUS(status);
601 }
602
603 /*******************************************************************************
604  *
605  * FUNCTION:    acpi_load_tables
606  *
607  * PARAMETERS:  None
608  *
609  * RETURN:      Status
610  *
611  * DESCRIPTION: Load the ACPI tables from the RSDT/XSDT
612  *
613  ******************************************************************************/
614
615 acpi_status acpi_load_tables(void)
616 {
617         acpi_status status;
618
619         ACPI_FUNCTION_TRACE(acpi_load_tables);
620
621         /*
622          * Load the namespace from the tables
623          */
624         status = acpi_tb_load_namespace();
625         if (ACPI_FAILURE(status)) {
626                 ACPI_EXCEPTION((AE_INFO, status,
627                                 "While loading namespace from ACPI tables"));
628         }
629
630         return_ACPI_STATUS(status);
631 }
632
633 ACPI_EXPORT_SYMBOL(acpi_load_tables)
634
635
636 /*******************************************************************************
637  *
638  * FUNCTION:    acpi_install_table_handler
639  *
640  * PARAMETERS:  Handler         - Table event handler
641  *              Context         - Value passed to the handler on each event
642  *
643  * RETURN:      Status
644  *
645  * DESCRIPTION: Install table event handler
646  *
647  ******************************************************************************/
648 acpi_status
649 acpi_install_table_handler(acpi_tbl_handler handler, void *context)
650 {
651         acpi_status status;
652
653         ACPI_FUNCTION_TRACE(acpi_install_table_handler);
654
655         if (!handler) {
656                 return_ACPI_STATUS(AE_BAD_PARAMETER);
657         }
658
659         status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
660         if (ACPI_FAILURE(status)) {
661                 return_ACPI_STATUS(status);
662         }
663
664         /* Don't allow more than one handler */
665
666         if (acpi_gbl_table_handler) {
667                 status = AE_ALREADY_EXISTS;
668                 goto cleanup;
669         }
670
671         /* Install the handler */
672
673         acpi_gbl_table_handler = handler;
674         acpi_gbl_table_handler_context = context;
675
676       cleanup:
677         (void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
678         return_ACPI_STATUS(status);
679 }
680
681 ACPI_EXPORT_SYMBOL(acpi_install_table_handler)
682
683 /*******************************************************************************
684  *
685  * FUNCTION:    acpi_remove_table_handler
686  *
687  * PARAMETERS:  Handler         - Table event handler that was installed
688  *                                previously.
689  *
690  * RETURN:      Status
691  *
692  * DESCRIPTION: Remove table event handler
693  *
694  ******************************************************************************/
695 acpi_status acpi_remove_table_handler(acpi_tbl_handler handler)
696 {
697         acpi_status status;
698
699         ACPI_FUNCTION_TRACE(acpi_remove_table_handler);
700
701         status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
702         if (ACPI_FAILURE(status)) {
703                 return_ACPI_STATUS(status);
704         }
705
706         /* Make sure that the installed handler is the same */
707
708         if (!handler || handler != acpi_gbl_table_handler) {
709                 status = AE_BAD_PARAMETER;
710                 goto cleanup;
711         }
712
713         /* Remove the handler */
714
715         acpi_gbl_table_handler = NULL;
716
717       cleanup:
718         (void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
719         return_ACPI_STATUS(status);
720 }
721
722 ACPI_EXPORT_SYMBOL(acpi_remove_table_handler)
723
724
725 static int __init acpi_no_auto_ssdt_setup(char *s) {
726
727         printk(KERN_NOTICE "ACPI: SSDT auto-load disabled\n");
728
729         no_auto_ssdt = 1;
730
731         return 1;
732 }
733
734 __setup("acpi_no_auto_ssdt", acpi_no_auto_ssdt_setup);