summaryrefslogtreecommitdiff
path: root/drivers/acpi/tables/tbxfroot.c
blob: 3b8a7e063e8a14c5d5122d306dfcef19d61d8c94 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
/******************************************************************************
 *
 * Module Name: tbxfroot - Find the root ACPI table (RSDT)
 *
 *****************************************************************************/

/*
 * Copyright (C) 2000 - 2005, R. Byron Moore
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions, and the following disclaimer,
 *    without modification.
 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 *    substantially similar to the "NO WARRANTY" disclaimer below
 *    ("Disclaimer") and any redistribution must be conditioned upon
 *    including a substantially similar Disclaimer requirement for further
 *    binary redistribution.
 * 3. Neither the names of the above-listed copyright holders nor the names
 *    of any contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * NO WARRANTY
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 */

#include <linux/module.h>

#include <acpi/acpi.h>
#include <acpi/actables.h>

#define _COMPONENT          ACPI_TABLES
ACPI_MODULE_NAME("tbxfroot")

/* Local prototypes */
static acpi_status
acpi_tb_find_rsdp(struct acpi_table_desc *table_info, u32 flags);

static u8 *acpi_tb_scan_memory_for_rsdp(u8 * start_address, u32 length);

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_validate_rsdp
 *
 * PARAMETERS:  Rsdp        - Pointer to unvalidated RSDP
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Validate the RSDP (ptr)
 *
 ******************************************************************************/

acpi_status acpi_tb_validate_rsdp(struct rsdp_descriptor *rsdp)
{
	ACPI_FUNCTION_ENTRY();

	/*
	 *  The signature and checksum must both be correct
	 */
	if (ACPI_STRNCMP((char *)rsdp, RSDP_SIG, sizeof(RSDP_SIG) - 1) != 0) {
		/* Nope, BAD Signature */

		return (AE_BAD_SIGNATURE);
	}

	/* Check the standard checksum */

	if (acpi_tb_generate_checksum(rsdp, ACPI_RSDP_CHECKSUM_LENGTH) != 0) {
		return (AE_BAD_CHECKSUM);
	}

	/* Check extended checksum if table version >= 2 */

	if ((rsdp->revision >= 2) &&
	    (acpi_tb_generate_checksum(rsdp, ACPI_RSDP_XCHECKSUM_LENGTH) !=
	     0)) {
		return (AE_BAD_CHECKSUM);
	}

	return (AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_find_table
 *
 * PARAMETERS:  Signature           - String with ACPI table signature
 *              oem_id              - String with the table OEM ID
 *              oem_table_id        - String with the OEM Table ID
 *              table_ptr           - Where the table pointer is returned
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Find an ACPI table (in the RSDT/XSDT) that matches the
 *              Signature, OEM ID and OEM Table ID.
 *
 ******************************************************************************/

acpi_status
acpi_tb_find_table(char *signature,
		   char *oem_id,
		   char *oem_table_id, struct acpi_table_header ** table_ptr)
{
	acpi_status status;
	struct acpi_table_header *table;

	ACPI_FUNCTION_TRACE("tb_find_table");

	/* Validate string lengths */

	if ((ACPI_STRLEN(signature) > ACPI_NAME_SIZE) ||
	    (ACPI_STRLEN(oem_id) > sizeof(table->oem_id)) ||
	    (ACPI_STRLEN(oem_table_id) > sizeof(table->oem_table_id))) {
		return_ACPI_STATUS(AE_AML_STRING_LIMIT);
	}

	if (!ACPI_STRNCMP(signature, DSDT_SIG, ACPI_NAME_SIZE)) {
		/*
		 * The DSDT pointer is contained in the FADT, not the RSDT.
		 * This code should suffice, because the only code that would perform
		 * a "find" on the DSDT is the data_table_region() AML opcode -- in
		 * which case, the DSDT is guaranteed to be already loaded.
		 * If this becomes insufficient, the FADT will have to be found first.
		 */
		if (!acpi_gbl_DSDT) {
			return_ACPI_STATUS(AE_NO_ACPI_TABLES);
		}
		table = acpi_gbl_DSDT;
	} else {
		/* Find the table */

		status = acpi_get_firmware_table(signature, 1,
						 ACPI_LOGICAL_ADDRESSING,
						 &table);
		if (ACPI_FAILURE(status)) {
			return_ACPI_STATUS(status);
		}
	}

	/* Check oem_id and oem_table_id */

	if ((oem_id[0] && ACPI_STRNCMP(oem_id, table->oem_id,
				       sizeof(table->oem_id))) ||
	    (oem_table_id[0] && ACPI_STRNCMP(oem_table_id, table->oem_table_id,
					     sizeof(table->oem_table_id)))) {
		return_ACPI_STATUS(AE_AML_NAME_NOT_FOUND);
	}

	ACPI_DEBUG_PRINT((ACPI_DB_TABLES, "Found table [%4.4s]\n",
			  table->signature));

	*table_ptr = table;
	return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_get_firmware_table
 *
 * PARAMETERS:  Signature       - Any ACPI table signature
 *              Instance        - the non zero instance of the table, allows
 *                                support for multiple tables of the same type
 *              Flags           - Physical/Virtual support
 *              table_pointer   - Where a buffer containing the table is
 *                                returned
 *
 * RETURN:      Status
 *
 * DESCRIPTION: This function is called to get an ACPI table. A buffer is
 *              allocated for the table and returned in table_pointer.
 *              This table will be a complete table including the header.
 *
 ******************************************************************************/

acpi_status
acpi_get_firmware_table(acpi_string signature,
			u32 instance,
			u32 flags, struct acpi_table_header **table_pointer)
{
	acpi_status status;
	struct acpi_pointer address;
	struct acpi_table_header *header = NULL;
	struct acpi_table_desc *table_info = NULL;
	struct acpi_table_desc *rsdt_info;
	u32 table_count;
	u32 i;
	u32 j;

	ACPI_FUNCTION_TRACE("acpi_get_firmware_table");

	/*
	 * Ensure that at least the table manager is initialized.  We don't
	 * require that the entire ACPI subsystem is up for this interface.
	 * If we have a buffer, we must have a length too
	 */
	if ((instance == 0) || (!signature) || (!table_pointer)) {
		return_ACPI_STATUS(AE_BAD_PARAMETER);
	}

	/* Ensure that we have a RSDP */

	if (!acpi_gbl_RSDP) {
		/* Get the RSDP */

		status = acpi_os_get_root_pointer(flags, &address);
		if (ACPI_FAILURE(status)) {
			ACPI_DEBUG_PRINT((ACPI_DB_INFO, "RSDP not found\n"));
			return_ACPI_STATUS(AE_NO_ACPI_TABLES);
		}

		/* Map and validate the RSDP */

		if ((flags & ACPI_MEMORY_MODE) == ACPI_LOGICAL_ADDRESSING) {
			status = acpi_os_map_memory(address.pointer.physical,
						    sizeof(struct
							   rsdp_descriptor),
						    (void *)&acpi_gbl_RSDP);
			if (ACPI_FAILURE(status)) {
				return_ACPI_STATUS(status);
			}
		} else {
			acpi_gbl_RSDP = address.pointer.logical;
		}

		/* The RDSP signature and checksum must both be correct */

		status = acpi_tb_validate_rsdp(acpi_gbl_RSDP);
		if (ACPI_FAILURE(status)) {
			return_ACPI_STATUS(status);
		}
	}

	/* Get the RSDT address via the RSDP */

	acpi_tb_get_rsdt_address(&address);
	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
			  "RSDP located at %p, RSDT physical=%8.8X%8.8X \n",
			  acpi_gbl_RSDP,
			  ACPI_FORMAT_UINT64(address.pointer.value)));

	/* Insert processor_mode flags */

	address.pointer_type |= flags;

	/* Get and validate the RSDT */

	rsdt_info = ACPI_MEM_CALLOCATE(sizeof(struct acpi_table_desc));
	if (!rsdt_info) {
		return_ACPI_STATUS(AE_NO_MEMORY);
	}

	status = acpi_tb_get_table(&address, rsdt_info);
	if (ACPI_FAILURE(status)) {
		goto cleanup;
	}

	status = acpi_tb_validate_rsdt(rsdt_info->pointer);
	if (ACPI_FAILURE(status)) {
		goto cleanup;
	}

	/* Allocate a scratch table header and table descriptor */

	header = ACPI_MEM_ALLOCATE(sizeof(struct acpi_table_header));
	if (!header) {
		status = AE_NO_MEMORY;
		goto cleanup;
	}

	table_info = ACPI_MEM_ALLOCATE(sizeof(struct acpi_table_desc));
	if (!table_info) {
		status = AE_NO_MEMORY;
		goto cleanup;
	}

	/* Get the number of table pointers within the RSDT */

	table_count =
	    acpi_tb_get_table_count(acpi_gbl_RSDP, rsdt_info->pointer);
	address.pointer_type = acpi_gbl_table_flags | flags;

	/*
	 * Search the RSDT/XSDT for the correct instance of the
	 * requested table
	 */
	for (i = 0, j = 0; i < table_count; i++) {
		/*
		 * Get the next table pointer, handle RSDT vs. XSDT
		 * RSDT pointers are 32 bits, XSDT pointers are 64 bits
		 */
		if (acpi_gbl_root_table_type == ACPI_TABLE_TYPE_RSDT) {
			address.pointer.value =
			    (ACPI_CAST_PTR
			     (RSDT_DESCRIPTOR,
			      rsdt_info->pointer))->table_offset_entry[i];
		} else {
			address.pointer.value =
			    (ACPI_CAST_PTR
			     (XSDT_DESCRIPTOR,
			      rsdt_info->pointer))->table_offset_entry[i];
		}

		/* Get the table header */

		status = acpi_tb_get_table_header(&address, header);
		if (ACPI_FAILURE(status)) {
			goto cleanup;
		}

		/* Compare table signatures and table instance */

		if (!ACPI_STRNCMP(header->signature, signature, ACPI_NAME_SIZE)) {
			/* An instance of the table was found */

			j++;
			if (j >= instance) {
				/* Found the correct instance, get the entire table */

				status =
				    acpi_tb_get_table_body(&address, header,
							   table_info);
				if (ACPI_FAILURE(status)) {
					goto cleanup;
				}

				*table_pointer = table_info->pointer;
				goto cleanup;
			}
		}
	}

	/* Did not find the table */

	status = AE_NOT_EXIST;

      cleanup:
	if (rsdt_info->pointer) {
		acpi_os_unmap_memory(rsdt_info->pointer,
				     (acpi_size) rsdt_info->pointer->length);
	}
	ACPI_MEM_FREE(rsdt_info);

	if (header) {
		ACPI_MEM_FREE(header);
	}
	if (table_info) {
		ACPI_MEM_FREE(table_info);
	}
	return_ACPI_STATUS(status);
}

EXPORT_SYMBOL(acpi_get_firmware_table);

/* TBD: Move to a new file */

#if ACPI_MACHINE_WIDTH != 16

/*******************************************************************************
 *
 * FUNCTION:    acpi_find_root_pointer
 *
 * PARAMETERS:  Flags                   - Logical/Physical addressing
 *              rsdp_address            - Where to place the RSDP address
 *
 * RETURN:      Status, Physical address of the RSDP
 *
 * DESCRIPTION: Find the RSDP
 *
 ******************************************************************************/

acpi_status acpi_find_root_pointer(u32 flags, struct acpi_pointer *rsdp_address)
{
	struct acpi_table_desc table_info;
	acpi_status status;

	ACPI_FUNCTION_TRACE("acpi_find_root_pointer");

	/* Get the RSDP */

	status = acpi_tb_find_rsdp(&table_info, flags);
	if (ACPI_FAILURE(status)) {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
				  "RSDP structure not found, %s Flags=%X\n",
				  acpi_format_exception(status), flags));

		return_ACPI_STATUS(AE_NO_ACPI_TABLES);
	}

	rsdp_address->pointer_type = ACPI_PHYSICAL_POINTER;
	rsdp_address->pointer.physical = table_info.physical_address;
	return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_scan_memory_for_rsdp
 *
 * PARAMETERS:  start_address       - Starting pointer for search
 *              Length              - Maximum length to search
 *
 * RETURN:      Pointer to the RSDP if found, otherwise NULL.
 *
 * DESCRIPTION: Search a block of memory for the RSDP signature
 *
 ******************************************************************************/

static u8 *acpi_tb_scan_memory_for_rsdp(u8 * start_address, u32 length)
{
	acpi_status status;
	u8 *mem_rover;
	u8 *end_address;

	ACPI_FUNCTION_TRACE("tb_scan_memory_for_rsdp");

	end_address = start_address + length;

	/* Search from given start address for the requested length */

	for (mem_rover = start_address; mem_rover < end_address;
	     mem_rover += ACPI_RSDP_SCAN_STEP) {
		/* The RSDP signature and checksum must both be correct */

		status =
		    acpi_tb_validate_rsdp(ACPI_CAST_PTR
					  (struct rsdp_descriptor, mem_rover));
		if (ACPI_SUCCESS(status)) {
			/* Sig and checksum valid, we have found a real RSDP */

			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
					  "RSDP located at physical address %p\n",
					  mem_rover));
			return_PTR(mem_rover);
		}

		/* No sig match or bad checksum, keep searching */
	}

	/* Searched entire block, no RSDP was found */

	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
			  "Searched entire block from %p, valid RSDP was not found\n",
			  start_address));
	return_PTR(NULL);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_tb_find_rsdp
 *
 * PARAMETERS:  table_info              - Where the table info is returned
 *              Flags                   - Current memory mode (logical vs.
 *                                        physical addressing)
 *
 * RETURN:      Status, RSDP physical address
 *
 * DESCRIPTION: search lower 1_mbyte of memory for the root system descriptor
 *              pointer structure.  If it is found, set *RSDP to point to it.
 *
 *              NOTE1: The RSDp must be either in the first 1_k of the Extended
 *              BIOS Data Area or between E0000 and FFFFF (From ACPI Spec.)
 *              Only a 32-bit physical address is necessary.
 *
 *              NOTE2: This function is always available, regardless of the
 *              initialization state of the rest of ACPI.
 *
 ******************************************************************************/

static acpi_status
acpi_tb_find_rsdp(struct acpi_table_desc *table_info, u32 flags)
{
	u8 *table_ptr;
	u8 *mem_rover;
	u32 physical_address;
	acpi_status status;

	ACPI_FUNCTION_TRACE("tb_find_rsdp");

	/*
	 * Scan supports either logical addressing or physical addressing
	 */
	if ((flags & ACPI_MEMORY_MODE) == ACPI_LOGICAL_ADDRESSING) {
		/* 1a) Get the location of the Extended BIOS Data Area (EBDA) */

		status = acpi_os_map_memory((acpi_physical_address)
					    ACPI_EBDA_PTR_LOCATION,
					    ACPI_EBDA_PTR_LENGTH,
					    (void *)&table_ptr);
		if (ACPI_FAILURE(status)) {
			ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
					  "Could not map memory at %8.8X for length %X\n",
					  ACPI_EBDA_PTR_LOCATION,
					  ACPI_EBDA_PTR_LENGTH));

			return_ACPI_STATUS(status);
		}

		ACPI_MOVE_16_TO_32(&physical_address, table_ptr);

		/* Convert segment part to physical address */

		physical_address <<= 4;
		acpi_os_unmap_memory(table_ptr, ACPI_EBDA_PTR_LENGTH);

		/* EBDA present? */

		if (physical_address > 0x400) {
			/*
			 * 1b) Search EBDA paragraphs (EBDa is required to be a
			 *     minimum of 1_k length)
			 */
			status = acpi_os_map_memory((acpi_physical_address)
						    physical_address,
						    ACPI_EBDA_WINDOW_SIZE,
						    (void *)&table_ptr);
			if (ACPI_FAILURE(status)) {
				ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
						  "Could not map memory at %8.8X for length %X\n",
						  physical_address,
						  ACPI_EBDA_WINDOW_SIZE));

				return_ACPI_STATUS(status);
			}

			mem_rover = acpi_tb_scan_memory_for_rsdp(table_ptr,
								 ACPI_EBDA_WINDOW_SIZE);
			acpi_os_unmap_memory(table_ptr, ACPI_EBDA_WINDOW_SIZE);

			if (mem_rover) {
				/* Return the physical address */

				physical_address +=
				    ACPI_PTR_DIFF(mem_rover, table_ptr);

				table_info->physical_address =
				    (acpi_physical_address) physical_address;
				return_ACPI_STATUS(AE_OK);
			}
		}

		/*
		 * 2) Search upper memory: 16-byte boundaries in E0000h-FFFFFh
		 */
		status = acpi_os_map_memory((acpi_physical_address)
					    ACPI_HI_RSDP_WINDOW_BASE,
					    ACPI_HI_RSDP_WINDOW_SIZE,
					    (void *)&table_ptr);

		if (ACPI_FAILURE(status)) {
			ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
					  "Could not map memory at %8.8X for length %X\n",
					  ACPI_HI_RSDP_WINDOW_BASE,
					  ACPI_HI_RSDP_WINDOW_SIZE));

			return_ACPI_STATUS(status);
		}

		mem_rover =
		    acpi_tb_scan_memory_for_rsdp(table_ptr,
						 ACPI_HI_RSDP_WINDOW_SIZE);
		acpi_os_unmap_memory(table_ptr, ACPI_HI_RSDP_WINDOW_SIZE);

		if (mem_rover) {
			/* Return the physical address */

			physical_address =
			    ACPI_HI_RSDP_WINDOW_BASE + ACPI_PTR_DIFF(mem_rover,
								     table_ptr);

			table_info->physical_address =
			    (acpi_physical_address) physical_address;
			return_ACPI_STATUS(AE_OK);
		}
	}

	/*
	 * Physical addressing
	 */
	else {
		/* 1a) Get the location of the EBDA */

		ACPI_MOVE_16_TO_32(&physical_address, ACPI_EBDA_PTR_LOCATION);
		physical_address <<= 4;	/* Convert segment to physical address */

		/* EBDA present? */

		if (physical_address > 0x400) {
			/*
			 * 1b) Search EBDA paragraphs (EBDa is required to be a minimum of
			 *     1_k length)
			 */
			mem_rover =
			    acpi_tb_scan_memory_for_rsdp(ACPI_PHYSADDR_TO_PTR
							 (physical_address),
							 ACPI_EBDA_WINDOW_SIZE);
			if (mem_rover) {
				/* Return the physical address */

				table_info->physical_address =
				    ACPI_TO_INTEGER(mem_rover);
				return_ACPI_STATUS(AE_OK);
			}
		}

		/* 2) Search upper memory: 16-byte boundaries in E0000h-FFFFFh */

		mem_rover =
		    acpi_tb_scan_memory_for_rsdp(ACPI_PHYSADDR_TO_PTR
						 (ACPI_HI_RSDP_WINDOW_BASE),
						 ACPI_HI_RSDP_WINDOW_SIZE);
		if (mem_rover) {
			/* Found it, return the physical address */

			table_info->physical_address =
			    ACPI_TO_INTEGER(mem_rover);
			return_ACPI_STATUS(AE_OK);
		}
	}

	/* A valid RSDP was not found */

	ACPI_REPORT_ERROR(("No valid RSDP was found\n"));
	return_ACPI_STATUS(AE_NOT_FOUND);
}

#endif