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 - 2012, 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
52ACPI_MODULE_NAME("tbxface")
53
54/* Local prototypes */
55static acpi_status acpi_tb_load_namespace(void);
56
57static 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
73acpi_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
108acpi_status __init
109acpi_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 ******************************************************************************/
172acpi_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 ******************************************************************************/
238acpi_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
263ACPI_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 ******************************************************************************/
281acpi_status
282acpi_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
340ACPI_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 ******************************************************************************/
353acpi_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
379ACPI_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 ******************************************************************************/
394acpi_status
395acpi_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
440acpi_status
441acpi_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}
449ACPI_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 ******************************************************************************/
463acpi_status
464acpi_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
503ACPI_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 ******************************************************************************/
517static 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
630acpi_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
647ACPI_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 ******************************************************************************/
662acpi_status
663acpi_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
695ACPI_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 ******************************************************************************/
709acpi_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
736ACPI_EXPORT_SYMBOL(acpi_remove_table_handler)
737
738
739static 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);
749