ACPICA: hide private headers
[linux-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 - 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 =
154             acpi_tb_parse_root_table(rsdp_address, ACPI_TABLE_ORIGIN_MAPPED);
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
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         new_size = ((acpi_size) acpi_gbl_root_table_list.count +
188                     ACPI_ROOT_TABLE_SIZE_INCREMENT) *
189             sizeof(struct acpi_table_desc);
190
191         /* Create new array and copy the old array */
192
193         tables = ACPI_ALLOCATE_ZEROED(new_size);
194         if (!tables) {
195                 return_ACPI_STATUS(AE_NO_MEMORY);
196         }
197
198         ACPI_MEMCPY(tables, acpi_gbl_root_table_list.tables, new_size);
199
200         acpi_gbl_root_table_list.size = acpi_gbl_root_table_list.count;
201         acpi_gbl_root_table_list.tables = tables;
202         acpi_gbl_root_table_list.flags =
203             ACPI_ROOT_ORIGIN_ALLOCATED | ACPI_ROOT_ALLOW_RESIZE;
204
205         return_ACPI_STATUS(AE_OK);
206 }
207
208 /*******************************************************************************
209  *
210  * FUNCTION:    acpi_load_table
211  *
212  * PARAMETERS:  table_ptr       - pointer to a buffer containing the entire
213  *                                table to be loaded
214  *
215  * RETURN:      Status
216  *
217  * DESCRIPTION: This function is called to load a table from the caller's
218  *              buffer. The buffer must contain an entire ACPI Table including
219  *              a valid header. The header fields will be verified, and if it
220  *              is determined that the table is invalid, the call will fail.
221  *
222  ******************************************************************************/
223 acpi_status acpi_load_table(struct acpi_table_header *table_ptr)
224 {
225         acpi_status status;
226         u32 table_index;
227         struct acpi_table_desc table_desc;
228
229         if (!table_ptr)
230                 return AE_BAD_PARAMETER;
231
232         ACPI_MEMSET(&table_desc, 0, sizeof(struct acpi_table_desc));
233         table_desc.pointer = table_ptr;
234         table_desc.length = table_ptr->length;
235         table_desc.flags = ACPI_TABLE_ORIGIN_UNKNOWN;
236
237         /*
238          * Install the new table into the local data structures
239          */
240         status = acpi_tb_add_table(&table_desc, &table_index);
241         if (ACPI_FAILURE(status)) {
242                 return status;
243         }
244         status = acpi_ns_load_table(table_index, acpi_gbl_root_node);
245         return status;
246 }
247
248 ACPI_EXPORT_SYMBOL(acpi_load_table)
249
250 /******************************************************************************
251  *
252  * FUNCTION:    acpi_get_table_header
253  *
254  * PARAMETERS:  Signature           - ACPI signature of needed table
255  *              Instance            - Which instance (for SSDTs)
256  *              out_table_header    - The pointer to the table header to fill
257  *
258  * RETURN:      Status and pointer to mapped table header
259  *
260  * DESCRIPTION: Finds an ACPI table header.
261  *
262  * NOTE:        Caller is responsible in unmapping the header with
263  *              acpi_os_unmap_memory
264  *
265  *****************************************************************************/
266 acpi_status
267 acpi_get_table_header(char *signature,
268                       u32 instance, struct acpi_table_header *out_table_header)
269 {
270        u32 i;
271        u32 j;
272         struct acpi_table_header *header;
273
274         /* Parameter validation */
275
276         if (!signature || !out_table_header) {
277                 return (AE_BAD_PARAMETER);
278         }
279
280         /*
281          * Walk the root table list
282          */
283         for (i = 0, j = 0; i < acpi_gbl_root_table_list.count; i++) {
284                 if (!ACPI_COMPARE_NAME
285                     (&(acpi_gbl_root_table_list.tables[i].signature),
286                      signature)) {
287                         continue;
288                 }
289
290                 if (++j < instance) {
291                         continue;
292                 }
293
294                 if (!acpi_gbl_root_table_list.tables[i].pointer) {
295                         if ((acpi_gbl_root_table_list.tables[i].
296                              flags & ACPI_TABLE_ORIGIN_MASK) ==
297                             ACPI_TABLE_ORIGIN_MAPPED) {
298                                 header =
299                                     acpi_os_map_memory(acpi_gbl_root_table_list.
300                                                        tables[i].address,
301                                                        sizeof(struct
302                                                               acpi_table_header));
303                                 if (!header) {
304                                         return AE_NO_MEMORY;
305                                 }
306                                 ACPI_MEMCPY(out_table_header, header,
307                                             sizeof(struct acpi_table_header));
308                                 acpi_os_unmap_memory(header,
309                                                      sizeof(struct
310                                                             acpi_table_header));
311                         } else {
312                                 return AE_NOT_FOUND;
313                         }
314                 } else {
315                         ACPI_MEMCPY(out_table_header,
316                                     acpi_gbl_root_table_list.tables[i].pointer,
317                                     sizeof(struct acpi_table_header));
318                 }
319                 return (AE_OK);
320         }
321
322         return (AE_NOT_FOUND);
323 }
324
325 ACPI_EXPORT_SYMBOL(acpi_get_table_header)
326
327 /******************************************************************************
328  *
329  * FUNCTION:    acpi_unload_table_id
330  *
331  * PARAMETERS:  id            - Owner ID of the table to be removed.
332  *
333  * RETURN:      Status
334  *
335  * DESCRIPTION: This routine is used to force the unload of a table (by id)
336  *
337  ******************************************************************************/
338 acpi_status acpi_unload_table_id(acpi_owner_id id)
339 {
340         int i;
341         acpi_status status = AE_NOT_EXIST;
342
343         ACPI_FUNCTION_TRACE(acpi_unload_table_id);
344
345         /* Find table in the global table list */
346         for (i = 0; i < acpi_gbl_root_table_list.count; ++i) {
347                 if (id != acpi_gbl_root_table_list.tables[i].owner_id) {
348                         continue;
349                 }
350                 /*
351                  * Delete all namespace objects owned by this table. Note that these
352                  * objects can appear anywhere in the namespace by virtue of the AML
353                  * "Scope" operator. Thus, we need to track ownership by an ID, not
354                  * simply a position within the hierarchy
355                  */
356                 acpi_tb_delete_namespace_by_owner(i);
357                 status = acpi_tb_release_owner_id(i);
358                 acpi_tb_set_table_loaded_flag(i, FALSE);
359                 break;
360         }
361         return_ACPI_STATUS(status);
362 }
363
364 ACPI_EXPORT_SYMBOL(acpi_unload_table_id)
365
366 /*******************************************************************************
367  *
368  * FUNCTION:    acpi_get_table
369  *
370  * PARAMETERS:  Signature           - ACPI signature of needed table
371  *              Instance            - Which instance (for SSDTs)
372  *              out_table           - Where the pointer to the table is returned
373  *
374  * RETURN:      Status and pointer to table
375  *
376  * DESCRIPTION: Finds and verifies an ACPI table.
377  *
378  *****************************************************************************/
379 acpi_status
380 acpi_get_table(char *signature,
381                u32 instance, struct acpi_table_header **out_table)
382 {
383        u32 i;
384        u32 j;
385         acpi_status status;
386
387         /* Parameter validation */
388
389         if (!signature || !out_table) {
390                 return (AE_BAD_PARAMETER);
391         }
392
393         /*
394          * Walk the root table list
395          */
396         for (i = 0, j = 0; i < acpi_gbl_root_table_list.count; i++) {
397                 if (!ACPI_COMPARE_NAME
398                     (&(acpi_gbl_root_table_list.tables[i].signature),
399                      signature)) {
400                         continue;
401                 }
402
403                 if (++j < instance) {
404                         continue;
405                 }
406
407                 status =
408                     acpi_tb_verify_table(&acpi_gbl_root_table_list.tables[i]);
409                 if (ACPI_SUCCESS(status)) {
410                         *out_table = acpi_gbl_root_table_list.tables[i].pointer;
411                 }
412
413                 if (!acpi_gbl_permanent_mmap) {
414                         acpi_gbl_root_table_list.tables[i].pointer = NULL;
415                 }
416
417                 return (status);
418         }
419
420         return (AE_NOT_FOUND);
421 }
422
423 ACPI_EXPORT_SYMBOL(acpi_get_table)
424
425 /*******************************************************************************
426  *
427  * FUNCTION:    acpi_get_table_by_index
428  *
429  * PARAMETERS:  table_index         - Table index
430  *              Table               - Where the pointer to the table is returned
431  *
432  * RETURN:      Status and pointer to the table
433  *
434  * DESCRIPTION: Obtain a table by an index into the global table list.
435  *
436  ******************************************************************************/
437 acpi_status
438 acpi_get_table_by_index(u32 table_index, struct acpi_table_header **table)
439 {
440         acpi_status status;
441
442         ACPI_FUNCTION_TRACE(acpi_get_table_by_index);
443
444         /* Parameter validation */
445
446         if (!table) {
447                 return_ACPI_STATUS(AE_BAD_PARAMETER);
448         }
449
450         (void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
451
452         /* Validate index */
453
454         if (table_index >= acpi_gbl_root_table_list.count) {
455                 (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
456                 return_ACPI_STATUS(AE_BAD_PARAMETER);
457         }
458
459         if (!acpi_gbl_root_table_list.tables[table_index].pointer) {
460
461                 /* Table is not mapped, map it */
462
463                 status =
464                     acpi_tb_verify_table(&acpi_gbl_root_table_list.
465                                          tables[table_index]);
466                 if (ACPI_FAILURE(status)) {
467                         (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
468                         return_ACPI_STATUS(status);
469                 }
470         }
471
472         *table = acpi_gbl_root_table_list.tables[table_index].pointer;
473         (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
474         return_ACPI_STATUS(AE_OK);
475 }
476
477 ACPI_EXPORT_SYMBOL(acpi_get_table_by_index)
478
479 /*******************************************************************************
480  *
481  * FUNCTION:    acpi_tb_load_namespace
482  *
483  * PARAMETERS:  None
484  *
485  * RETURN:      Status
486  *
487  * DESCRIPTION: Load the namespace from the DSDT and all SSDTs/PSDTs found in
488  *              the RSDT/XSDT.
489  *
490  ******************************************************************************/
491 static acpi_status acpi_tb_load_namespace(void)
492 {
493         acpi_status status;
494         struct acpi_table_header *table;
495         u32 i;
496
497         ACPI_FUNCTION_TRACE(tb_load_namespace);
498
499         (void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
500
501         /*
502          * Load the namespace. The DSDT is required, but any SSDT and PSDT tables
503          * are optional.
504          */
505         if (!acpi_gbl_root_table_list.count ||
506             !ACPI_COMPARE_NAME(&
507                                (acpi_gbl_root_table_list.
508                                 tables[ACPI_TABLE_INDEX_DSDT].signature),
509                                ACPI_SIG_DSDT)
510             ||
511             ACPI_FAILURE(acpi_tb_verify_table
512                          (&acpi_gbl_root_table_list.
513                           tables[ACPI_TABLE_INDEX_DSDT]))) {
514                 status = AE_NO_ACPI_TABLES;
515                 goto unlock_and_exit;
516         }
517
518         /*
519          * Find DSDT table
520          */
521         status =
522             acpi_os_table_override(acpi_gbl_root_table_list.
523                                    tables[ACPI_TABLE_INDEX_DSDT].pointer,
524                                    &table);
525         if (ACPI_SUCCESS(status) && table) {
526                 /*
527                  * DSDT table has been found
528                  */
529                 acpi_tb_delete_table(&acpi_gbl_root_table_list.
530                                      tables[ACPI_TABLE_INDEX_DSDT]);
531                 acpi_gbl_root_table_list.tables[ACPI_TABLE_INDEX_DSDT].pointer =
532                     table;
533                 acpi_gbl_root_table_list.tables[ACPI_TABLE_INDEX_DSDT].length =
534                     table->length;
535                 acpi_gbl_root_table_list.tables[ACPI_TABLE_INDEX_DSDT].flags =
536                     ACPI_TABLE_ORIGIN_UNKNOWN;
537
538                 ACPI_INFO((AE_INFO, "Table DSDT replaced by host OS"));
539                 acpi_tb_print_table_header(0, table);
540
541                 if (no_auto_ssdt == 0) {
542                         printk(KERN_WARNING "ACPI: DSDT override uses original SSDTs unless \"acpi_no_auto_ssdt\"\n");
543                 }
544         }
545
546         status =
547             acpi_tb_verify_table(&acpi_gbl_root_table_list.
548                                  tables[ACPI_TABLE_INDEX_DSDT]);
549         if (ACPI_FAILURE(status)) {
550
551                 /* A valid DSDT is required */
552
553                 status = AE_NO_ACPI_TABLES;
554                 goto unlock_and_exit;
555         }
556
557         (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
558
559         /*
560          * Load and parse tables.
561          */
562         status = acpi_ns_load_table(ACPI_TABLE_INDEX_DSDT, acpi_gbl_root_node);
563         if (ACPI_FAILURE(status)) {
564                 return_ACPI_STATUS(status);
565         }
566
567         /*
568          * Load any SSDT or PSDT tables. Note: Loop leaves tables locked
569          */
570         (void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
571         for (i = 0; i < acpi_gbl_root_table_list.count; ++i) {
572                 if ((!ACPI_COMPARE_NAME
573                      (&(acpi_gbl_root_table_list.tables[i].signature),
574                       ACPI_SIG_SSDT)
575                      &&
576                      !ACPI_COMPARE_NAME(&
577                                         (acpi_gbl_root_table_list.tables[i].
578                                          signature), ACPI_SIG_PSDT))
579                     ||
580                     ACPI_FAILURE(acpi_tb_verify_table
581                                  (&acpi_gbl_root_table_list.tables[i]))) {
582                         continue;
583                 }
584
585                 if (no_auto_ssdt) {
586                         printk(KERN_WARNING "ACPI: SSDT ignored due to \"acpi_no_auto_ssdt\"\n");
587                         continue;
588                 }
589
590                 /* Ignore errors while loading tables, get as many as possible */
591
592                 (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
593                 (void)acpi_ns_load_table(i, acpi_gbl_root_node);
594                 (void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
595         }
596
597         ACPI_DEBUG_PRINT((ACPI_DB_INIT, "ACPI Tables successfully acquired\n"));
598
599       unlock_and_exit:
600         (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
601         return_ACPI_STATUS(status);
602 }
603
604 /*******************************************************************************
605  *
606  * FUNCTION:    acpi_load_tables
607  *
608  * PARAMETERS:  None
609  *
610  * RETURN:      Status
611  *
612  * DESCRIPTION: Load the ACPI tables from the RSDT/XSDT
613  *
614  ******************************************************************************/
615
616 acpi_status acpi_load_tables(void)
617 {
618         acpi_status status;
619
620         ACPI_FUNCTION_TRACE(acpi_load_tables);
621
622         /*
623          * Load the namespace from the tables
624          */
625         status = acpi_tb_load_namespace();
626         if (ACPI_FAILURE(status)) {
627                 ACPI_EXCEPTION((AE_INFO, status,
628                                 "While loading namespace from ACPI tables"));
629         }
630
631         return_ACPI_STATUS(status);
632 }
633
634 ACPI_EXPORT_SYMBOL(acpi_load_tables)
635
636
637 /*******************************************************************************
638  *
639  * FUNCTION:    acpi_install_table_handler
640  *
641  * PARAMETERS:  Handler         - Table event handler
642  *              Context         - Value passed to the handler on each event
643  *
644  * RETURN:      Status
645  *
646  * DESCRIPTION: Install table event handler
647  *
648  ******************************************************************************/
649 acpi_status
650 acpi_install_table_handler(acpi_tbl_handler handler, void *context)
651 {
652         acpi_status status;
653
654         ACPI_FUNCTION_TRACE(acpi_install_table_handler);
655
656         if (!handler) {
657                 return_ACPI_STATUS(AE_BAD_PARAMETER);
658         }
659
660         status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
661         if (ACPI_FAILURE(status)) {
662                 return_ACPI_STATUS(status);
663         }
664
665         /* Don't allow more than one handler */
666
667         if (acpi_gbl_table_handler) {
668                 status = AE_ALREADY_EXISTS;
669                 goto cleanup;
670         }
671
672         /* Install the handler */
673
674         acpi_gbl_table_handler = handler;
675         acpi_gbl_table_handler_context = context;
676
677       cleanup:
678         (void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
679         return_ACPI_STATUS(status);
680 }
681
682 ACPI_EXPORT_SYMBOL(acpi_install_table_handler)
683
684 /*******************************************************************************
685  *
686  * FUNCTION:    acpi_remove_table_handler
687  *
688  * PARAMETERS:  Handler         - Table event handler that was installed
689  *                                previously.
690  *
691  * RETURN:      Status
692  *
693  * DESCRIPTION: Remove table event handler
694  *
695  ******************************************************************************/
696 acpi_status acpi_remove_table_handler(acpi_tbl_handler handler)
697 {
698         acpi_status status;
699
700         ACPI_FUNCTION_TRACE(acpi_remove_table_handler);
701
702         status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
703         if (ACPI_FAILURE(status)) {
704                 return_ACPI_STATUS(status);
705         }
706
707         /* Make sure that the installed handler is the same */
708
709         if (!handler || handler != acpi_gbl_table_handler) {
710                 status = AE_BAD_PARAMETER;
711                 goto cleanup;
712         }
713
714         /* Remove the handler */
715
716         acpi_gbl_table_handler = NULL;
717
718       cleanup:
719         (void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
720         return_ACPI_STATUS(status);
721 }
722
723 ACPI_EXPORT_SYMBOL(acpi_remove_table_handler)
724
725
726 static int __init acpi_no_auto_ssdt_setup(char *s) {
727
728         printk(KERN_NOTICE "ACPI: SSDT auto-load disabled\n");
729
730         no_auto_ssdt = 1;
731
732         return 1;
733 }
734
735 __setup("acpi_no_auto_ssdt", acpi_no_auto_ssdt_setup);