ACPICA: Update all ACPICA copyrights and signons to 2010
[linux-3.10.git] / drivers / acpi / acpica / tbutils.c
1 /******************************************************************************
2  *
3  * Module Name: tbutils   - table utilities
4  *
5  *****************************************************************************/
6
7 /*
8  * Copyright (C) 2000 - 2010, Intel Corp.
9  * All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions, and the following disclaimer,
16  *    without modification.
17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
18  *    substantially similar to the "NO WARRANTY" disclaimer below
19  *    ("Disclaimer") and any redistribution must be conditioned upon
20  *    including a substantially similar Disclaimer requirement for further
21  *    binary redistribution.
22  * 3. Neither the names of the above-listed copyright holders nor the names
23  *    of any contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * Alternatively, this software may be distributed under the terms of the
27  * GNU General Public License ("GPL") version 2 as published by the Free
28  * Software Foundation.
29  *
30  * NO WARRANTY
31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
41  * POSSIBILITY OF SUCH DAMAGES.
42  */
43
44 #include <acpi/acpi.h>
45 #include "accommon.h"
46 #include "actables.h"
47
48 #define _COMPONENT          ACPI_TABLES
49 ACPI_MODULE_NAME("tbutils")
50
51 /* Local prototypes */
52 static void acpi_tb_fix_string(char *string, acpi_size length);
53
54 static void
55 acpi_tb_cleanup_table_header(struct acpi_table_header *out_header,
56                              struct acpi_table_header *header);
57
58 static acpi_physical_address
59 acpi_tb_get_root_table_entry(u8 *table_entry, u32 table_entry_size);
60
61 /*******************************************************************************
62  *
63  * FUNCTION:    acpi_tb_check_xsdt
64  *
65  * PARAMETERS:  address                    - Pointer to the XSDT
66  *
67  * RETURN:      status
68  *              AE_OK - XSDT is okay
69  *              AE_NO_MEMORY - can't map XSDT
70  *              AE_INVALID_TABLE_LENGTH - invalid table length
71  *              AE_NULL_ENTRY - XSDT has NULL entry
72  *
73  * DESCRIPTION: validate XSDT
74 ******************************************************************************/
75
76 static acpi_status
77 acpi_tb_check_xsdt(acpi_physical_address address)
78 {
79         struct acpi_table_header *table;
80         u32 length;
81         u64 xsdt_entry_address;
82         u8 *table_entry;
83         u32 table_count;
84         int i;
85
86         table = acpi_os_map_memory(address, sizeof(struct acpi_table_header));
87         if (!table)
88                 return AE_NO_MEMORY;
89
90         length = table->length;
91         acpi_os_unmap_memory(table, sizeof(struct acpi_table_header));
92         if (length < sizeof(struct acpi_table_header))
93                 return AE_INVALID_TABLE_LENGTH;
94
95         table = acpi_os_map_memory(address, length);
96         if (!table)
97                 return AE_NO_MEMORY;
98
99         /* Calculate the number of tables described in XSDT */
100         table_count =
101                 (u32) ((table->length -
102                 sizeof(struct acpi_table_header)) / sizeof(u64));
103         table_entry =
104                 ACPI_CAST_PTR(u8, table) + sizeof(struct acpi_table_header);
105         for (i = 0; i < table_count; i++) {
106                 ACPI_MOVE_64_TO_64(&xsdt_entry_address, table_entry);
107                 if (!xsdt_entry_address) {
108                         /* XSDT has NULL entry */
109                         break;
110                 }
111                 table_entry += sizeof(u64);
112         }
113         acpi_os_unmap_memory(table, length);
114
115         if (i < table_count)
116                 return AE_NULL_ENTRY;
117         else
118                 return AE_OK;
119 }
120
121 /*******************************************************************************
122  *
123  * FUNCTION:    acpi_tb_initialize_facs
124  *
125  * PARAMETERS:  None
126  *
127  * RETURN:      Status
128  *
129  * DESCRIPTION: Create a permanent mapping for the FADT and save it in a global
130  *              for accessing the Global Lock and Firmware Waking Vector
131  *
132  ******************************************************************************/
133
134 acpi_status acpi_tb_initialize_facs(void)
135 {
136         acpi_status status;
137
138         status = acpi_get_table_by_index(ACPI_TABLE_INDEX_FACS,
139                                          ACPI_CAST_INDIRECT_PTR(struct
140                                                                 acpi_table_header,
141                                                                 &acpi_gbl_FACS));
142         return status;
143 }
144
145 /*******************************************************************************
146  *
147  * FUNCTION:    acpi_tb_tables_loaded
148  *
149  * PARAMETERS:  None
150  *
151  * RETURN:      TRUE if required ACPI tables are loaded
152  *
153  * DESCRIPTION: Determine if the minimum required ACPI tables are present
154  *              (FADT, FACS, DSDT)
155  *
156  ******************************************************************************/
157
158 u8 acpi_tb_tables_loaded(void)
159 {
160
161         if (acpi_gbl_root_table_list.count >= 3) {
162                 return (TRUE);
163         }
164
165         return (FALSE);
166 }
167
168 /*******************************************************************************
169  *
170  * FUNCTION:    acpi_tb_fix_string
171  *
172  * PARAMETERS:  String              - String to be repaired
173  *              Length              - Maximum length
174  *
175  * RETURN:      None
176  *
177  * DESCRIPTION: Replace every non-printable or non-ascii byte in the string
178  *              with a question mark '?'.
179  *
180  ******************************************************************************/
181
182 static void acpi_tb_fix_string(char *string, acpi_size length)
183 {
184
185         while (length && *string) {
186                 if (!ACPI_IS_PRINT(*string)) {
187                         *string = '?';
188                 }
189                 string++;
190                 length--;
191         }
192 }
193
194 /*******************************************************************************
195  *
196  * FUNCTION:    acpi_tb_cleanup_table_header
197  *
198  * PARAMETERS:  out_header          - Where the cleaned header is returned
199  *              Header              - Input ACPI table header
200  *
201  * RETURN:      Returns the cleaned header in out_header
202  *
203  * DESCRIPTION: Copy the table header and ensure that all "string" fields in
204  *              the header consist of printable characters.
205  *
206  ******************************************************************************/
207
208 static void
209 acpi_tb_cleanup_table_header(struct acpi_table_header *out_header,
210                              struct acpi_table_header *header)
211 {
212
213         ACPI_MEMCPY(out_header, header, sizeof(struct acpi_table_header));
214
215         acpi_tb_fix_string(out_header->signature, ACPI_NAME_SIZE);
216         acpi_tb_fix_string(out_header->oem_id, ACPI_OEM_ID_SIZE);
217         acpi_tb_fix_string(out_header->oem_table_id, ACPI_OEM_TABLE_ID_SIZE);
218         acpi_tb_fix_string(out_header->asl_compiler_id, ACPI_NAME_SIZE);
219 }
220
221 /*******************************************************************************
222  *
223  * FUNCTION:    acpi_tb_print_table_header
224  *
225  * PARAMETERS:  Address             - Table physical address
226  *              Header              - Table header
227  *
228  * RETURN:      None
229  *
230  * DESCRIPTION: Print an ACPI table header. Special cases for FACS and RSDP.
231  *
232  ******************************************************************************/
233
234 void
235 acpi_tb_print_table_header(acpi_physical_address address,
236                            struct acpi_table_header *header)
237 {
238         struct acpi_table_header local_header;
239
240         /*
241          * The reason that the Address is cast to a void pointer is so that we
242          * can use %p which will work properly on both 32-bit and 64-bit hosts.
243          */
244         if (ACPI_COMPARE_NAME(header->signature, ACPI_SIG_FACS)) {
245
246                 /* FACS only has signature and length fields */
247
248                 ACPI_INFO((AE_INFO, "%4.4s %p %05X",
249                            header->signature, ACPI_CAST_PTR(void, address),
250                            header->length));
251         } else if (ACPI_COMPARE_NAME(header->signature, ACPI_SIG_RSDP)) {
252
253                 /* RSDP has no common fields */
254
255                 ACPI_MEMCPY(local_header.oem_id,
256                             ACPI_CAST_PTR(struct acpi_table_rsdp,
257                                           header)->oem_id, ACPI_OEM_ID_SIZE);
258                 acpi_tb_fix_string(local_header.oem_id, ACPI_OEM_ID_SIZE);
259
260                 ACPI_INFO((AE_INFO, "RSDP %p %05X (v%.2d %6.6s)",
261                            ACPI_CAST_PTR (void, address),
262                            (ACPI_CAST_PTR(struct acpi_table_rsdp, header)->
263                             revision >
264                             0) ? ACPI_CAST_PTR(struct acpi_table_rsdp,
265                                                header)->length : 20,
266                            ACPI_CAST_PTR(struct acpi_table_rsdp,
267                                          header)->revision,
268                            local_header.oem_id));
269         } else {
270                 /* Standard ACPI table with full common header */
271
272                 acpi_tb_cleanup_table_header(&local_header, header);
273
274                 ACPI_INFO((AE_INFO,
275                            "%4.4s %p %05X (v%.2d %6.6s %8.8s %08X %4.4s %08X)",
276                            local_header.signature, ACPI_CAST_PTR(void, address),
277                            local_header.length, local_header.revision,
278                            local_header.oem_id, local_header.oem_table_id,
279                            local_header.oem_revision,
280                            local_header.asl_compiler_id,
281                            local_header.asl_compiler_revision));
282
283         }
284 }
285
286 /*******************************************************************************
287  *
288  * FUNCTION:    acpi_tb_validate_checksum
289  *
290  * PARAMETERS:  Table               - ACPI table to verify
291  *              Length              - Length of entire table
292  *
293  * RETURN:      Status
294  *
295  * DESCRIPTION: Verifies that the table checksums to zero. Optionally returns
296  *              exception on bad checksum.
297  *
298  ******************************************************************************/
299
300 acpi_status acpi_tb_verify_checksum(struct acpi_table_header *table, u32 length)
301 {
302         u8 checksum;
303
304         /* Compute the checksum on the table */
305
306         checksum = acpi_tb_checksum(ACPI_CAST_PTR(u8, table), length);
307
308         /* Checksum ok? (should be zero) */
309
310         if (checksum) {
311                 ACPI_WARNING((AE_INFO,
312                               "Incorrect checksum in table [%4.4s] - %2.2X, should be %2.2X",
313                               table->signature, table->checksum,
314                               (u8) (table->checksum - checksum)));
315
316 #if (ACPI_CHECKSUM_ABORT)
317
318                 return (AE_BAD_CHECKSUM);
319 #endif
320         }
321
322         return (AE_OK);
323 }
324
325 /*******************************************************************************
326  *
327  * FUNCTION:    acpi_tb_checksum
328  *
329  * PARAMETERS:  Buffer          - Pointer to memory region to be checked
330  *              Length          - Length of this memory region
331  *
332  * RETURN:      Checksum (u8)
333  *
334  * DESCRIPTION: Calculates circular checksum of memory region.
335  *
336  ******************************************************************************/
337
338 u8 acpi_tb_checksum(u8 *buffer, u32 length)
339 {
340         u8 sum = 0;
341         u8 *end = buffer + length;
342
343         while (buffer < end) {
344                 sum = (u8) (sum + *(buffer++));
345         }
346
347         return sum;
348 }
349
350 /*******************************************************************************
351  *
352  * FUNCTION:    acpi_tb_install_table
353  *
354  * PARAMETERS:  Address                 - Physical address of DSDT or FACS
355  *              Signature               - Table signature, NULL if no need to
356  *                                        match
357  *              table_index             - Index into root table array
358  *
359  * RETURN:      None
360  *
361  * DESCRIPTION: Install an ACPI table into the global data structure. The
362  *              table override mechanism is implemented here to allow the host
363  *              OS to replace any table before it is installed in the root
364  *              table array.
365  *
366  ******************************************************************************/
367
368 void
369 acpi_tb_install_table(acpi_physical_address address,
370                       char *signature, u32 table_index)
371 {
372         u8 flags;
373         acpi_status status;
374         struct acpi_table_header *table_to_install;
375         struct acpi_table_header *mapped_table;
376         struct acpi_table_header *override_table = NULL;
377
378         if (!address) {
379                 ACPI_ERROR((AE_INFO,
380                             "Null physical address for ACPI table [%s]",
381                             signature));
382                 return;
383         }
384
385         /* Map just the table header */
386
387         mapped_table =
388             acpi_os_map_memory(address, sizeof(struct acpi_table_header));
389         if (!mapped_table) {
390                 return;
391         }
392
393         /* If a particular signature is expected (DSDT/FACS), it must match */
394
395         if (signature && !ACPI_COMPARE_NAME(mapped_table->signature, signature)) {
396                 ACPI_ERROR((AE_INFO,
397                             "Invalid signature 0x%X for ACPI table, expected [%s]",
398                             *ACPI_CAST_PTR(u32, mapped_table->signature),
399                             signature));
400                 goto unmap_and_exit;
401         }
402
403         /*
404          * ACPI Table Override:
405          *
406          * Before we install the table, let the host OS override it with a new
407          * one if desired. Any table within the RSDT/XSDT can be replaced,
408          * including the DSDT which is pointed to by the FADT.
409          */
410         status = acpi_os_table_override(mapped_table, &override_table);
411         if (ACPI_SUCCESS(status) && override_table) {
412                 ACPI_INFO((AE_INFO,
413                            "%4.4s @ 0x%p Table override, replaced with:",
414                            mapped_table->signature, ACPI_CAST_PTR(void,
415                                                                   address)));
416
417                 acpi_gbl_root_table_list.tables[table_index].pointer =
418                     override_table;
419                 address = ACPI_PTR_TO_PHYSADDR(override_table);
420
421                 table_to_install = override_table;
422                 flags = ACPI_TABLE_ORIGIN_OVERRIDE;
423         } else {
424                 table_to_install = mapped_table;
425                 flags = ACPI_TABLE_ORIGIN_MAPPED;
426         }
427
428         /* Initialize the table entry */
429
430         acpi_gbl_root_table_list.tables[table_index].address = address;
431         acpi_gbl_root_table_list.tables[table_index].length =
432             table_to_install->length;
433         acpi_gbl_root_table_list.tables[table_index].flags = flags;
434
435         ACPI_MOVE_32_TO_32(&
436                            (acpi_gbl_root_table_list.tables[table_index].
437                             signature), table_to_install->signature);
438
439         acpi_tb_print_table_header(address, table_to_install);
440
441         if (table_index == ACPI_TABLE_INDEX_DSDT) {
442
443                 /* Global integer width is based upon revision of the DSDT */
444
445                 acpi_ut_set_integer_width(table_to_install->revision);
446         }
447
448       unmap_and_exit:
449         acpi_os_unmap_memory(mapped_table, sizeof(struct acpi_table_header));
450 }
451
452 /*******************************************************************************
453  *
454  * FUNCTION:    acpi_tb_get_root_table_entry
455  *
456  * PARAMETERS:  table_entry         - Pointer to the RSDT/XSDT table entry
457  *              table_entry_size    - sizeof 32 or 64 (RSDT or XSDT)
458  *
459  * RETURN:      Physical address extracted from the root table
460  *
461  * DESCRIPTION: Get one root table entry. Handles 32-bit and 64-bit cases on
462  *              both 32-bit and 64-bit platforms
463  *
464  * NOTE:        acpi_physical_address is 32-bit on 32-bit platforms, 64-bit on
465  *              64-bit platforms.
466  *
467  ******************************************************************************/
468
469 static acpi_physical_address
470 acpi_tb_get_root_table_entry(u8 *table_entry, u32 table_entry_size)
471 {
472         u64 address64;
473
474         /*
475          * Get the table physical address (32-bit for RSDT, 64-bit for XSDT):
476          * Note: Addresses are 32-bit aligned (not 64) in both RSDT and XSDT
477          */
478         if (table_entry_size == sizeof(u32)) {
479                 /*
480                  * 32-bit platform, RSDT: Return 32-bit table entry
481                  * 64-bit platform, RSDT: Expand 32-bit to 64-bit and return
482                  */
483                 return ((acpi_physical_address)
484                         (*ACPI_CAST_PTR(u32, table_entry)));
485         } else {
486                 /*
487                  * 32-bit platform, XSDT: Truncate 64-bit to 32-bit and return
488                  * 64-bit platform, XSDT: Move (unaligned) 64-bit to local,
489                  *  return 64-bit
490                  */
491                 ACPI_MOVE_64_TO_64(&address64, table_entry);
492
493 #if ACPI_MACHINE_WIDTH == 32
494                 if (address64 > ACPI_UINT32_MAX) {
495
496                         /* Will truncate 64-bit address to 32 bits, issue warning */
497
498                         ACPI_WARNING((AE_INFO,
499                                       "64-bit Physical Address in XSDT is too large (%8.8X%8.8X),"
500                                       " truncating",
501                                       ACPI_FORMAT_UINT64(address64)));
502                 }
503 #endif
504                 return ((acpi_physical_address) (address64));
505         }
506 }
507
508 /*******************************************************************************
509  *
510  * FUNCTION:    acpi_tb_parse_root_table
511  *
512  * PARAMETERS:  Rsdp                    - Pointer to the RSDP
513  *
514  * RETURN:      Status
515  *
516  * DESCRIPTION: This function is called to parse the Root System Description
517  *              Table (RSDT or XSDT)
518  *
519  * NOTE:        Tables are mapped (not copied) for efficiency. The FACS must
520  *              be mapped and cannot be copied because it contains the actual
521  *              memory location of the ACPI Global Lock.
522  *
523  ******************************************************************************/
524
525 acpi_status __init
526 acpi_tb_parse_root_table(acpi_physical_address rsdp_address)
527 {
528         struct acpi_table_rsdp *rsdp;
529         u32 table_entry_size;
530         u32 i;
531         u32 table_count;
532         struct acpi_table_header *table;
533         acpi_physical_address address;
534         acpi_physical_address uninitialized_var(rsdt_address);
535         u32 length;
536         u8 *table_entry;
537         acpi_status status;
538
539         ACPI_FUNCTION_TRACE(tb_parse_root_table);
540
541         /*
542          * Map the entire RSDP and extract the address of the RSDT or XSDT
543          */
544         rsdp = acpi_os_map_memory(rsdp_address, sizeof(struct acpi_table_rsdp));
545         if (!rsdp) {
546                 return_ACPI_STATUS(AE_NO_MEMORY);
547         }
548
549         acpi_tb_print_table_header(rsdp_address,
550                                    ACPI_CAST_PTR(struct acpi_table_header,
551                                                  rsdp));
552
553         /* Differentiate between RSDT and XSDT root tables */
554
555         if (rsdp->revision > 1 && rsdp->xsdt_physical_address
556                         && !acpi_rsdt_forced) {
557                 /*
558                  * Root table is an XSDT (64-bit physical addresses). We must use the
559                  * XSDT if the revision is > 1 and the XSDT pointer is present, as per
560                  * the ACPI specification.
561                  */
562                 address = (acpi_physical_address) rsdp->xsdt_physical_address;
563                 table_entry_size = sizeof(u64);
564                 rsdt_address = (acpi_physical_address)
565                                         rsdp->rsdt_physical_address;
566         } else {
567                 /* Root table is an RSDT (32-bit physical addresses) */
568
569                 address = (acpi_physical_address) rsdp->rsdt_physical_address;
570                 table_entry_size = sizeof(u32);
571         }
572
573         /*
574          * It is not possible to map more than one entry in some environments,
575          * so unmap the RSDP here before mapping other tables
576          */
577         acpi_os_unmap_memory(rsdp, sizeof(struct acpi_table_rsdp));
578
579         if (table_entry_size == sizeof(u64)) {
580                 if (acpi_tb_check_xsdt(address) == AE_NULL_ENTRY) {
581                         /* XSDT has NULL entry, RSDT is used */
582                         address = rsdt_address;
583                         table_entry_size = sizeof(u32);
584                         ACPI_WARNING((AE_INFO, "BIOS XSDT has NULL entry, "
585                                         "using RSDT"));
586                 }
587         }
588         /* Map the RSDT/XSDT table header to get the full table length */
589
590         table = acpi_os_map_memory(address, sizeof(struct acpi_table_header));
591         if (!table) {
592                 return_ACPI_STATUS(AE_NO_MEMORY);
593         }
594
595         acpi_tb_print_table_header(address, table);
596
597         /* Get the length of the full table, verify length and map entire table */
598
599         length = table->length;
600         acpi_os_unmap_memory(table, sizeof(struct acpi_table_header));
601
602         if (length < sizeof(struct acpi_table_header)) {
603                 ACPI_ERROR((AE_INFO, "Invalid length 0x%X in RSDT/XSDT",
604                             length));
605                 return_ACPI_STATUS(AE_INVALID_TABLE_LENGTH);
606         }
607
608         table = acpi_os_map_memory(address, length);
609         if (!table) {
610                 return_ACPI_STATUS(AE_NO_MEMORY);
611         }
612
613         /* Validate the root table checksum */
614
615         status = acpi_tb_verify_checksum(table, length);
616         if (ACPI_FAILURE(status)) {
617                 acpi_os_unmap_memory(table, length);
618                 return_ACPI_STATUS(status);
619         }
620
621         /* Calculate the number of tables described in the root table */
622
623         table_count = (u32)((table->length - sizeof(struct acpi_table_header)) /
624                             table_entry_size);
625         /*
626          * First two entries in the table array are reserved for the DSDT
627          * and FACS, which are not actually present in the RSDT/XSDT - they
628          * come from the FADT
629          */
630         table_entry =
631             ACPI_CAST_PTR(u8, table) + sizeof(struct acpi_table_header);
632         acpi_gbl_root_table_list.count = 2;
633
634         /*
635          * Initialize the root table array from the RSDT/XSDT
636          */
637         for (i = 0; i < table_count; i++) {
638                 if (acpi_gbl_root_table_list.count >=
639                     acpi_gbl_root_table_list.size) {
640
641                         /* There is no more room in the root table array, attempt resize */
642
643                         status = acpi_tb_resize_root_table_list();
644                         if (ACPI_FAILURE(status)) {
645                                 ACPI_WARNING((AE_INFO,
646                                               "Truncating %u table entries!",
647                                               (unsigned) (table_count -
648                                                (acpi_gbl_root_table_list.
649                                                count - 2))));
650                                 break;
651                         }
652                 }
653
654                 /* Get the table physical address (32-bit for RSDT, 64-bit for XSDT) */
655
656                 acpi_gbl_root_table_list.tables[acpi_gbl_root_table_list.count].
657                     address =
658                     acpi_tb_get_root_table_entry(table_entry, table_entry_size);
659
660                 table_entry += table_entry_size;
661                 acpi_gbl_root_table_list.count++;
662         }
663
664         /*
665          * It is not possible to map more than one entry in some environments,
666          * so unmap the root table here before mapping other tables
667          */
668         acpi_os_unmap_memory(table, length);
669
670         /*
671          * Complete the initialization of the root table array by examining
672          * the header of each table
673          */
674         for (i = 2; i < acpi_gbl_root_table_list.count; i++) {
675                 acpi_tb_install_table(acpi_gbl_root_table_list.tables[i].
676                                       address, NULL, i);
677
678                 /* Special case for FADT - get the DSDT and FACS */
679
680                 if (ACPI_COMPARE_NAME
681                     (&acpi_gbl_root_table_list.tables[i].signature,
682                      ACPI_SIG_FADT)) {
683                         acpi_tb_parse_fadt(i);
684                 }
685         }
686
687         return_ACPI_STATUS(AE_OK);
688 }