Revert "ARM: tegra: tegratab: dummy change"
[linux-2.6.git] / drivers / acpi / acpica / tbutils.c
1 /******************************************************************************
2  *
3  * Module Name: tbutils   - table utilities
4  *
5  *****************************************************************************/
6
7 /*
8  * Copyright (C) 2000 - 2012, 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 #if (!ACPI_REDUCED_HARDWARE)
122 /*******************************************************************************
123  *
124  * FUNCTION:    acpi_tb_initialize_facs
125  *
126  * PARAMETERS:  None
127  *
128  * RETURN:      Status
129  *
130  * DESCRIPTION: Create a permanent mapping for the FADT and save it in a global
131  *              for accessing the Global Lock and Firmware Waking Vector
132  *
133  ******************************************************************************/
134
135 acpi_status acpi_tb_initialize_facs(void)
136 {
137         acpi_status status;
138
139         /* If Hardware Reduced flag is set, there is no FACS */
140
141         if (acpi_gbl_reduced_hardware) {
142                 acpi_gbl_FACS = NULL;
143                 return (AE_OK);
144         }
145
146         status = acpi_get_table_by_index(ACPI_TABLE_INDEX_FACS,
147                                          ACPI_CAST_INDIRECT_PTR(struct
148                                                                 acpi_table_header,
149                                                                 &acpi_gbl_FACS));
150         return status;
151 }
152 #endif                          /* !ACPI_REDUCED_HARDWARE */
153
154 /*******************************************************************************
155  *
156  * FUNCTION:    acpi_tb_tables_loaded
157  *
158  * PARAMETERS:  None
159  *
160  * RETURN:      TRUE if required ACPI tables are loaded
161  *
162  * DESCRIPTION: Determine if the minimum required ACPI tables are present
163  *              (FADT, FACS, DSDT)
164  *
165  ******************************************************************************/
166
167 u8 acpi_tb_tables_loaded(void)
168 {
169
170         if (acpi_gbl_root_table_list.current_table_count >= 3) {
171                 return (TRUE);
172         }
173
174         return (FALSE);
175 }
176
177 /*******************************************************************************
178  *
179  * FUNCTION:    acpi_tb_fix_string
180  *
181  * PARAMETERS:  String              - String to be repaired
182  *              Length              - Maximum length
183  *
184  * RETURN:      None
185  *
186  * DESCRIPTION: Replace every non-printable or non-ascii byte in the string
187  *              with a question mark '?'.
188  *
189  ******************************************************************************/
190
191 static void acpi_tb_fix_string(char *string, acpi_size length)
192 {
193
194         while (length && *string) {
195                 if (!ACPI_IS_PRINT(*string)) {
196                         *string = '?';
197                 }
198                 string++;
199                 length--;
200         }
201 }
202
203 /*******************************************************************************
204  *
205  * FUNCTION:    acpi_tb_cleanup_table_header
206  *
207  * PARAMETERS:  out_header          - Where the cleaned header is returned
208  *              Header              - Input ACPI table header
209  *
210  * RETURN:      Returns the cleaned header in out_header
211  *
212  * DESCRIPTION: Copy the table header and ensure that all "string" fields in
213  *              the header consist of printable characters.
214  *
215  ******************************************************************************/
216
217 static void
218 acpi_tb_cleanup_table_header(struct acpi_table_header *out_header,
219                              struct acpi_table_header *header)
220 {
221
222         ACPI_MEMCPY(out_header, header, sizeof(struct acpi_table_header));
223
224         acpi_tb_fix_string(out_header->signature, ACPI_NAME_SIZE);
225         acpi_tb_fix_string(out_header->oem_id, ACPI_OEM_ID_SIZE);
226         acpi_tb_fix_string(out_header->oem_table_id, ACPI_OEM_TABLE_ID_SIZE);
227         acpi_tb_fix_string(out_header->asl_compiler_id, ACPI_NAME_SIZE);
228 }
229
230 /*******************************************************************************
231  *
232  * FUNCTION:    acpi_tb_print_table_header
233  *
234  * PARAMETERS:  Address             - Table physical address
235  *              Header              - Table header
236  *
237  * RETURN:      None
238  *
239  * DESCRIPTION: Print an ACPI table header. Special cases for FACS and RSDP.
240  *
241  ******************************************************************************/
242
243 void
244 acpi_tb_print_table_header(acpi_physical_address address,
245                            struct acpi_table_header *header)
246 {
247         struct acpi_table_header local_header;
248
249         /*
250          * The reason that the Address is cast to a void pointer is so that we
251          * can use %p which will work properly on both 32-bit and 64-bit hosts.
252          */
253         if (ACPI_COMPARE_NAME(header->signature, ACPI_SIG_FACS)) {
254
255                 /* FACS only has signature and length fields */
256
257                 ACPI_INFO((AE_INFO, "%4.4s %p %05X",
258                            header->signature, ACPI_CAST_PTR(void, address),
259                            header->length));
260         } else if (ACPI_COMPARE_NAME(header->signature, ACPI_SIG_RSDP)) {
261
262                 /* RSDP has no common fields */
263
264                 ACPI_MEMCPY(local_header.oem_id,
265                             ACPI_CAST_PTR(struct acpi_table_rsdp,
266                                           header)->oem_id, ACPI_OEM_ID_SIZE);
267                 acpi_tb_fix_string(local_header.oem_id, ACPI_OEM_ID_SIZE);
268
269                 ACPI_INFO((AE_INFO, "RSDP %p %05X (v%.2d %6.6s)",
270                            ACPI_CAST_PTR (void, address),
271                            (ACPI_CAST_PTR(struct acpi_table_rsdp, header)->
272                             revision >
273                             0) ? ACPI_CAST_PTR(struct acpi_table_rsdp,
274                                                header)->length : 20,
275                            ACPI_CAST_PTR(struct acpi_table_rsdp,
276                                          header)->revision,
277                            local_header.oem_id));
278         } else {
279                 /* Standard ACPI table with full common header */
280
281                 acpi_tb_cleanup_table_header(&local_header, header);
282
283                 ACPI_INFO((AE_INFO,
284                            "%4.4s %p %05X (v%.2d %6.6s %8.8s %08X %4.4s %08X)",
285                            local_header.signature, ACPI_CAST_PTR(void, address),
286                            local_header.length, local_header.revision,
287                            local_header.oem_id, local_header.oem_table_id,
288                            local_header.oem_revision,
289                            local_header.asl_compiler_id,
290                            local_header.asl_compiler_revision));
291
292         }
293 }
294
295 /*******************************************************************************
296  *
297  * FUNCTION:    acpi_tb_validate_checksum
298  *
299  * PARAMETERS:  Table               - ACPI table to verify
300  *              Length              - Length of entire table
301  *
302  * RETURN:      Status
303  *
304  * DESCRIPTION: Verifies that the table checksums to zero. Optionally returns
305  *              exception on bad checksum.
306  *
307  ******************************************************************************/
308
309 acpi_status acpi_tb_verify_checksum(struct acpi_table_header *table, u32 length)
310 {
311         u8 checksum;
312
313         /* Compute the checksum on the table */
314
315         checksum = acpi_tb_checksum(ACPI_CAST_PTR(u8, table), length);
316
317         /* Checksum ok? (should be zero) */
318
319         if (checksum) {
320                 ACPI_WARNING((AE_INFO,
321                               "Incorrect checksum in table [%4.4s] - 0x%2.2X, should be 0x%2.2X",
322                               table->signature, table->checksum,
323                               (u8) (table->checksum - checksum)));
324
325 #if (ACPI_CHECKSUM_ABORT)
326
327                 return (AE_BAD_CHECKSUM);
328 #endif
329         }
330
331         return (AE_OK);
332 }
333
334 /*******************************************************************************
335  *
336  * FUNCTION:    acpi_tb_checksum
337  *
338  * PARAMETERS:  Buffer          - Pointer to memory region to be checked
339  *              Length          - Length of this memory region
340  *
341  * RETURN:      Checksum (u8)
342  *
343  * DESCRIPTION: Calculates circular checksum of memory region.
344  *
345  ******************************************************************************/
346
347 u8 acpi_tb_checksum(u8 *buffer, u32 length)
348 {
349         u8 sum = 0;
350         u8 *end = buffer + length;
351
352         while (buffer < end) {
353                 sum = (u8) (sum + *(buffer++));
354         }
355
356         return sum;
357 }
358
359 /*******************************************************************************
360  *
361  * FUNCTION:    acpi_tb_check_dsdt_header
362  *
363  * PARAMETERS:  None
364  *
365  * RETURN:      None
366  *
367  * DESCRIPTION: Quick compare to check validity of the DSDT. This will detect
368  *              if the DSDT has been replaced from outside the OS and/or if
369  *              the DSDT header has been corrupted.
370  *
371  ******************************************************************************/
372
373 void acpi_tb_check_dsdt_header(void)
374 {
375
376         /* Compare original length and checksum to current values */
377
378         if (acpi_gbl_original_dsdt_header.length != acpi_gbl_DSDT->length ||
379             acpi_gbl_original_dsdt_header.checksum != acpi_gbl_DSDT->checksum) {
380                 ACPI_ERROR((AE_INFO,
381                             "The DSDT has been corrupted or replaced - old, new headers below"));
382                 acpi_tb_print_table_header(0, &acpi_gbl_original_dsdt_header);
383                 acpi_tb_print_table_header(0, acpi_gbl_DSDT);
384
385                 ACPI_ERROR((AE_INFO,
386                             "Please send DMI info to linux-acpi@vger.kernel.org\n"
387                             "If system does not work as expected, please boot with acpi=copy_dsdt"));
388
389                 /* Disable further error messages */
390
391                 acpi_gbl_original_dsdt_header.length = acpi_gbl_DSDT->length;
392                 acpi_gbl_original_dsdt_header.checksum =
393                     acpi_gbl_DSDT->checksum;
394         }
395 }
396
397 /*******************************************************************************
398  *
399  * FUNCTION:    acpi_tb_copy_dsdt
400  *
401  * PARAMETERS:  table_desc          - Installed table to copy
402  *
403  * RETURN:      None
404  *
405  * DESCRIPTION: Implements a subsystem option to copy the DSDT to local memory.
406  *              Some very bad BIOSs are known to either corrupt the DSDT or
407  *              install a new, bad DSDT. This copy works around the problem.
408  *
409  ******************************************************************************/
410
411 struct acpi_table_header *acpi_tb_copy_dsdt(u32 table_index)
412 {
413         struct acpi_table_header *new_table;
414         struct acpi_table_desc *table_desc;
415
416         table_desc = &acpi_gbl_root_table_list.tables[table_index];
417
418         new_table = ACPI_ALLOCATE(table_desc->length);
419         if (!new_table) {
420                 ACPI_ERROR((AE_INFO, "Could not copy DSDT of length 0x%X",
421                             table_desc->length));
422                 return (NULL);
423         }
424
425         ACPI_MEMCPY(new_table, table_desc->pointer, table_desc->length);
426         acpi_tb_delete_table(table_desc);
427         table_desc->pointer = new_table;
428         table_desc->flags = ACPI_TABLE_ORIGIN_ALLOCATED;
429
430         ACPI_INFO((AE_INFO,
431                    "Forced DSDT copy: length 0x%05X copied locally, original unmapped",
432                    new_table->length));
433
434         return (new_table);
435 }
436
437 /*******************************************************************************
438  *
439  * FUNCTION:    acpi_tb_install_table
440  *
441  * PARAMETERS:  Address                 - Physical address of DSDT or FACS
442  *              Signature               - Table signature, NULL if no need to
443  *                                        match
444  *              table_index             - Index into root table array
445  *
446  * RETURN:      None
447  *
448  * DESCRIPTION: Install an ACPI table into the global data structure. The
449  *              table override mechanism is called to allow the host
450  *              OS to replace any table before it is installed in the root
451  *              table array.
452  *
453  ******************************************************************************/
454
455 void
456 acpi_tb_install_table(acpi_physical_address address,
457                       char *signature, u32 table_index)
458 {
459         struct acpi_table_header *table;
460         struct acpi_table_header *final_table;
461         struct acpi_table_desc *table_desc;
462
463         if (!address) {
464                 ACPI_ERROR((AE_INFO,
465                             "Null physical address for ACPI table [%s]",
466                             signature));
467                 return;
468         }
469
470         /* Map just the table header */
471
472         table = acpi_os_map_memory(address, sizeof(struct acpi_table_header));
473         if (!table) {
474                 ACPI_ERROR((AE_INFO,
475                             "Could not map memory for table [%s] at %p",
476                             signature, ACPI_CAST_PTR(void, address)));
477                 return;
478         }
479
480         /* If a particular signature is expected (DSDT/FACS), it must match */
481
482         if (signature && !ACPI_COMPARE_NAME(table->signature, signature)) {
483                 ACPI_ERROR((AE_INFO,
484                             "Invalid signature 0x%X for ACPI table, expected [%s]",
485                             *ACPI_CAST_PTR(u32, table->signature), signature));
486                 goto unmap_and_exit;
487         }
488
489         /*
490          * Initialize the table entry. Set the pointer to NULL, since the
491          * table is not fully mapped at this time.
492          */
493         table_desc = &acpi_gbl_root_table_list.tables[table_index];
494
495         table_desc->address = address;
496         table_desc->pointer = NULL;
497         table_desc->length = table->length;
498         table_desc->flags = ACPI_TABLE_ORIGIN_MAPPED;
499         ACPI_MOVE_32_TO_32(table_desc->signature.ascii, table->signature);
500
501         /*
502          * ACPI Table Override:
503          *
504          * Before we install the table, let the host OS override it with a new
505          * one if desired. Any table within the RSDT/XSDT can be replaced,
506          * including the DSDT which is pointed to by the FADT.
507          *
508          * NOTE: If the table is overridden, then final_table will contain a
509          * mapped pointer to the full new table. If the table is not overridden,
510          * or if there has been a physical override, then the table will be
511          * fully mapped later (in verify table). In any case, we must
512          * unmap the header that was mapped above.
513          */
514         final_table = acpi_tb_table_override(table, table_desc);
515         if (!final_table) {
516                 final_table = table;    /* There was no override */
517         }
518
519         acpi_tb_print_table_header(table_desc->address, final_table);
520
521         /* Set the global integer width (based upon revision of the DSDT) */
522
523         if (table_index == ACPI_TABLE_INDEX_DSDT) {
524                 acpi_ut_set_integer_width(final_table->revision);
525         }
526
527         /*
528          * If we have a physical override during this early loading of the ACPI
529          * tables, unmap the table for now. It will be mapped again later when
530          * it is actually used. This supports very early loading of ACPI tables,
531          * before virtual memory is fully initialized and running within the
532          * host OS. Note: A logical override has the ACPI_TABLE_ORIGIN_OVERRIDE
533          * flag set and will not be deleted below.
534          */
535         if (final_table != table) {
536                 acpi_tb_delete_table(table_desc);
537         }
538
539       unmap_and_exit:
540
541         /* Always unmap the table header that we mapped above */
542
543         acpi_os_unmap_memory(table, sizeof(struct acpi_table_header));
544 }
545
546 /*******************************************************************************
547  *
548  * FUNCTION:    acpi_tb_get_root_table_entry
549  *
550  * PARAMETERS:  table_entry         - Pointer to the RSDT/XSDT table entry
551  *              table_entry_size    - sizeof 32 or 64 (RSDT or XSDT)
552  *
553  * RETURN:      Physical address extracted from the root table
554  *
555  * DESCRIPTION: Get one root table entry. Handles 32-bit and 64-bit cases on
556  *              both 32-bit and 64-bit platforms
557  *
558  * NOTE:        acpi_physical_address is 32-bit on 32-bit platforms, 64-bit on
559  *              64-bit platforms.
560  *
561  ******************************************************************************/
562
563 static acpi_physical_address
564 acpi_tb_get_root_table_entry(u8 *table_entry, u32 table_entry_size)
565 {
566         u64 address64;
567
568         /*
569          * Get the table physical address (32-bit for RSDT, 64-bit for XSDT):
570          * Note: Addresses are 32-bit aligned (not 64) in both RSDT and XSDT
571          */
572         if (table_entry_size == sizeof(u32)) {
573                 /*
574                  * 32-bit platform, RSDT: Return 32-bit table entry
575                  * 64-bit platform, RSDT: Expand 32-bit to 64-bit and return
576                  */
577                 return ((acpi_physical_address)
578                         (*ACPI_CAST_PTR(u32, table_entry)));
579         } else {
580                 /*
581                  * 32-bit platform, XSDT: Truncate 64-bit to 32-bit and return
582                  * 64-bit platform, XSDT: Move (unaligned) 64-bit to local,
583                  *  return 64-bit
584                  */
585                 ACPI_MOVE_64_TO_64(&address64, table_entry);
586
587 #if ACPI_MACHINE_WIDTH == 32
588                 if (address64 > ACPI_UINT32_MAX) {
589
590                         /* Will truncate 64-bit address to 32 bits, issue warning */
591
592                         ACPI_WARNING((AE_INFO,
593                                       "64-bit Physical Address in XSDT is too large (0x%8.8X%8.8X),"
594                                       " truncating",
595                                       ACPI_FORMAT_UINT64(address64)));
596                 }
597 #endif
598                 return ((acpi_physical_address) (address64));
599         }
600 }
601
602 /*******************************************************************************
603  *
604  * FUNCTION:    acpi_tb_parse_root_table
605  *
606  * PARAMETERS:  Rsdp                    - Pointer to the RSDP
607  *
608  * RETURN:      Status
609  *
610  * DESCRIPTION: This function is called to parse the Root System Description
611  *              Table (RSDT or XSDT)
612  *
613  * NOTE:        Tables are mapped (not copied) for efficiency. The FACS must
614  *              be mapped and cannot be copied because it contains the actual
615  *              memory location of the ACPI Global Lock.
616  *
617  ******************************************************************************/
618
619 acpi_status __init
620 acpi_tb_parse_root_table(acpi_physical_address rsdp_address)
621 {
622         struct acpi_table_rsdp *rsdp;
623         u32 table_entry_size;
624         u32 i;
625         u32 table_count;
626         struct acpi_table_header *table;
627         acpi_physical_address address;
628         acpi_physical_address uninitialized_var(rsdt_address);
629         u32 length;
630         u8 *table_entry;
631         acpi_status status;
632
633         ACPI_FUNCTION_TRACE(tb_parse_root_table);
634
635         /*
636          * Map the entire RSDP and extract the address of the RSDT or XSDT
637          */
638         rsdp = acpi_os_map_memory(rsdp_address, sizeof(struct acpi_table_rsdp));
639         if (!rsdp) {
640                 return_ACPI_STATUS(AE_NO_MEMORY);
641         }
642
643         acpi_tb_print_table_header(rsdp_address,
644                                    ACPI_CAST_PTR(struct acpi_table_header,
645                                                  rsdp));
646
647         /* Differentiate between RSDT and XSDT root tables */
648
649         if (rsdp->revision > 1 && rsdp->xsdt_physical_address
650                         && !acpi_rsdt_forced) {
651                 /*
652                  * Root table is an XSDT (64-bit physical addresses). We must use the
653                  * XSDT if the revision is > 1 and the XSDT pointer is present, as per
654                  * the ACPI specification.
655                  */
656                 address = (acpi_physical_address) rsdp->xsdt_physical_address;
657                 table_entry_size = sizeof(u64);
658                 rsdt_address = (acpi_physical_address)
659                                         rsdp->rsdt_physical_address;
660         } else {
661                 /* Root table is an RSDT (32-bit physical addresses) */
662
663                 address = (acpi_physical_address) rsdp->rsdt_physical_address;
664                 table_entry_size = sizeof(u32);
665         }
666
667         /*
668          * It is not possible to map more than one entry in some environments,
669          * so unmap the RSDP here before mapping other tables
670          */
671         acpi_os_unmap_memory(rsdp, sizeof(struct acpi_table_rsdp));
672
673         if (table_entry_size == sizeof(u64)) {
674                 if (acpi_tb_check_xsdt(address) == AE_NULL_ENTRY) {
675                         /* XSDT has NULL entry, RSDT is used */
676                         address = rsdt_address;
677                         table_entry_size = sizeof(u32);
678                         ACPI_WARNING((AE_INFO, "BIOS XSDT has NULL entry, "
679                                         "using RSDT"));
680                 }
681         }
682         /* Map the RSDT/XSDT table header to get the full table length */
683
684         table = acpi_os_map_memory(address, sizeof(struct acpi_table_header));
685         if (!table) {
686                 return_ACPI_STATUS(AE_NO_MEMORY);
687         }
688
689         acpi_tb_print_table_header(address, table);
690
691         /* Get the length of the full table, verify length and map entire table */
692
693         length = table->length;
694         acpi_os_unmap_memory(table, sizeof(struct acpi_table_header));
695
696         if (length < sizeof(struct acpi_table_header)) {
697                 ACPI_ERROR((AE_INFO, "Invalid length 0x%X in RSDT/XSDT",
698                             length));
699                 return_ACPI_STATUS(AE_INVALID_TABLE_LENGTH);
700         }
701
702         table = acpi_os_map_memory(address, length);
703         if (!table) {
704                 return_ACPI_STATUS(AE_NO_MEMORY);
705         }
706
707         /* Validate the root table checksum */
708
709         status = acpi_tb_verify_checksum(table, length);
710         if (ACPI_FAILURE(status)) {
711                 acpi_os_unmap_memory(table, length);
712                 return_ACPI_STATUS(status);
713         }
714
715         /* Calculate the number of tables described in the root table */
716
717         table_count = (u32)((table->length - sizeof(struct acpi_table_header)) /
718                             table_entry_size);
719         /*
720          * First two entries in the table array are reserved for the DSDT
721          * and FACS, which are not actually present in the RSDT/XSDT - they
722          * come from the FADT
723          */
724         table_entry =
725             ACPI_CAST_PTR(u8, table) + sizeof(struct acpi_table_header);
726         acpi_gbl_root_table_list.current_table_count = 2;
727
728         /*
729          * Initialize the root table array from the RSDT/XSDT
730          */
731         for (i = 0; i < table_count; i++) {
732                 if (acpi_gbl_root_table_list.current_table_count >=
733                     acpi_gbl_root_table_list.max_table_count) {
734
735                         /* There is no more room in the root table array, attempt resize */
736
737                         status = acpi_tb_resize_root_table_list();
738                         if (ACPI_FAILURE(status)) {
739                                 ACPI_WARNING((AE_INFO,
740                                               "Truncating %u table entries!",
741                                               (unsigned) (table_count -
742                                                (acpi_gbl_root_table_list.
743                                                           current_table_count -
744                                                           2))));
745                                 break;
746                         }
747                 }
748
749                 /* Get the table physical address (32-bit for RSDT, 64-bit for XSDT) */
750
751                 acpi_gbl_root_table_list.tables[acpi_gbl_root_table_list.
752                                                 current_table_count].address =
753                     acpi_tb_get_root_table_entry(table_entry, table_entry_size);
754
755                 table_entry += table_entry_size;
756                 acpi_gbl_root_table_list.current_table_count++;
757         }
758
759         /*
760          * It is not possible to map more than one entry in some environments,
761          * so unmap the root table here before mapping other tables
762          */
763         acpi_os_unmap_memory(table, length);
764
765         /*
766          * Complete the initialization of the root table array by examining
767          * the header of each table
768          */
769         for (i = 2; i < acpi_gbl_root_table_list.current_table_count; i++) {
770                 acpi_tb_install_table(acpi_gbl_root_table_list.tables[i].
771                                       address, NULL, i);
772
773                 /* Special case for FADT - get the DSDT and FACS */
774
775                 if (ACPI_COMPARE_NAME
776                     (&acpi_gbl_root_table_list.tables[i].signature,
777                      ACPI_SIG_FADT)) {
778                         acpi_tb_parse_fadt(i);
779                 }
780         }
781
782         return_ACPI_STATUS(AE_OK);
783 }