aboutsummaryrefslogtreecommitdiff
path: root/arch/powerpc/platforms/ps3/os-area.c
blob: cbddd63caf2dbd636fea81b2000fbcbe3cf1ea64 (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
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
// SPDX-License-Identifier: GPL-2.0-only
/*
 *  PS3 flash memory os area.
 *
 *  Copyright (C) 2006 Sony Computer Entertainment Inc.
 *  Copyright 2006 Sony Corp.
 */

#include <linux/kernel.h>
#include <linux/io.h>
#include <linux/workqueue.h>
#include <linux/fs.h>
#include <linux/syscalls.h>
#include <linux/export.h>
#include <linux/ctype.h>
#include <linux/memblock.h>
#include <linux/of.h>
#include <linux/slab.h>

#include <asm/prom.h>

#include "platform.h"

enum {
	OS_AREA_SEGMENT_SIZE = 0X200,
};

enum os_area_ldr_format {
	HEADER_LDR_FORMAT_RAW = 0,
	HEADER_LDR_FORMAT_GZIP = 1,
};

#define OS_AREA_HEADER_MAGIC_NUM "cell_ext_os_area"

/**
 * struct os_area_header - os area header segment.
 * @magic_num: Always 'cell_ext_os_area'.
 * @hdr_version: Header format version number.
 * @db_area_offset: Starting segment number of other os database area.
 * @ldr_area_offset: Starting segment number of bootloader image area.
 * @ldr_format: HEADER_LDR_FORMAT flag.
 * @ldr_size: Size of bootloader image in bytes.
 *
 * Note that the docs refer to area offsets.  These are offsets in units of
 * segments from the start of the os area (top of the header).  These are
 * better thought of as segment numbers.  The os area of the os area is
 * reserved for the os image.
 */

struct os_area_header {
	u8 magic_num[16];
	u32 hdr_version;
	u32 db_area_offset;
	u32 ldr_area_offset;
	u32 _reserved_1;
	u32 ldr_format;
	u32 ldr_size;
	u32 _reserved_2[6];
};

enum os_area_boot_flag {
	PARAM_BOOT_FLAG_GAME_OS = 0,
	PARAM_BOOT_FLAG_OTHER_OS = 1,
};

enum os_area_ctrl_button {
	PARAM_CTRL_BUTTON_O_IS_YES = 0,
	PARAM_CTRL_BUTTON_X_IS_YES = 1,
};

/**
 * struct os_area_params - os area params segment.
 * @boot_flag: User preference of operating system, PARAM_BOOT_FLAG flag.
 * @num_params: Number of params in this (params) segment.
 * @rtc_diff: Difference in seconds between 1970 and the ps3 rtc value.
 * @av_multi_out: User preference of AV output, PARAM_AV_MULTI_OUT flag.
 * @ctrl_button: User preference of controller button config, PARAM_CTRL_BUTTON
 *	flag.
 * @static_ip_addr: User preference of static IP address.
 * @network_mask: User preference of static network mask.
 * @default_gateway: User preference of static default gateway.
 * @dns_primary: User preference of static primary dns server.
 * @dns_secondary: User preference of static secondary dns server.
 *
 * The ps3 rtc maintains a read-only value that approximates seconds since
 * 2000-01-01 00:00:00 UTC.
 *
 * User preference of zero for static_ip_addr means use dhcp.
 */

struct os_area_params {
	u32 boot_flag;
	u32 _reserved_1[3];
	u32 num_params;
	u32 _reserved_2[3];
	/* param 0 */
	s64 rtc_diff;
	u8 av_multi_out;
	u8 ctrl_button;
	u8 _reserved_3[6];
	/* param 1 */
	u8 static_ip_addr[4];
	u8 network_mask[4];
	u8 default_gateway[4];
	u8 _reserved_4[4];
	/* param 2 */
	u8 dns_primary[4];
	u8 dns_secondary[4];
	u8 _reserved_5[8];
};

#define OS_AREA_DB_MAGIC_NUM "-db-"

/**
 * struct os_area_db - Shared flash memory database.
 * @magic_num: Always '-db-'.
 * @version: os_area_db format version number.
 * @index_64: byte offset of the database id index for 64 bit variables.
 * @count_64: number of usable 64 bit index entries
 * @index_32: byte offset of the database id index for 32 bit variables.
 * @count_32: number of usable 32 bit index entries
 * @index_16: byte offset of the database id index for 16 bit variables.
 * @count_16: number of usable 16 bit index entries
 *
 * Flash rom storage for exclusive use by guests running in the other os lpar.
 * The current system configuration allocates 1K (two segments) for other os
 * use.
 */

struct os_area_db {
	u8 magic_num[4];
	u16 version;
	u16 _reserved_1;
	u16 index_64;
	u16 count_64;
	u16 index_32;
	u16 count_32;
	u16 index_16;
	u16 count_16;
	u32 _reserved_2;
	u8 _db_data[1000];
};

/**
 * enum os_area_db_owner - Data owners.
 */

enum os_area_db_owner {
	OS_AREA_DB_OWNER_ANY = -1,
	OS_AREA_DB_OWNER_NONE = 0,
	OS_AREA_DB_OWNER_PROTOTYPE = 1,
	OS_AREA_DB_OWNER_LINUX = 2,
	OS_AREA_DB_OWNER_PETITBOOT = 3,
	OS_AREA_DB_OWNER_MAX = 32,
};

enum os_area_db_key {
	OS_AREA_DB_KEY_ANY = -1,
	OS_AREA_DB_KEY_NONE = 0,
	OS_AREA_DB_KEY_RTC_DIFF = 1,
	OS_AREA_DB_KEY_VIDEO_MODE = 2,
	OS_AREA_DB_KEY_MAX = 8,
};

struct os_area_db_id {
	int owner;
	int key;
};

static const struct os_area_db_id os_area_db_id_empty = {
	.owner = OS_AREA_DB_OWNER_NONE,
	.key = OS_AREA_DB_KEY_NONE
};

static const struct os_area_db_id os_area_db_id_any = {
	.owner = OS_AREA_DB_OWNER_ANY,
	.key = OS_AREA_DB_KEY_ANY
};

static const struct os_area_db_id os_area_db_id_rtc_diff = {
	.owner = OS_AREA_DB_OWNER_LINUX,
	.key = OS_AREA_DB_KEY_RTC_DIFF
};

#define SECONDS_FROM_1970_TO_2000 946684800LL

/**
 * struct saved_params - Static working copies of data from the PS3 'os area'.
 *
 * The order of preference we use for the rtc_diff source:
 *  1) The database value.
 *  2) The game os value.
 *  3) The number of seconds from 1970 to 2000.
 */

static struct saved_params {
	unsigned int valid;
	s64 rtc_diff;
	unsigned int av_multi_out;
} saved_params;

static struct property property_rtc_diff = {
	.name = "linux,rtc_diff",
	.length = sizeof(saved_params.rtc_diff),
	.value = &saved_params.rtc_diff,
};

static struct property property_av_multi_out = {
	.name = "linux,av_multi_out",
	.length = sizeof(saved_params.av_multi_out),
	.value = &saved_params.av_multi_out,
};


static DEFINE_MUTEX(os_area_flash_mutex);

static const struct ps3_os_area_flash_ops *os_area_flash_ops;

void ps3_os_area_flash_register(const struct ps3_os_area_flash_ops *ops)
{
	mutex_lock(&os_area_flash_mutex);
	os_area_flash_ops = ops;
	mutex_unlock(&os_area_flash_mutex);
}
EXPORT_SYMBOL_GPL(ps3_os_area_flash_register);

static ssize_t os_area_flash_read(void *buf, size_t count, loff_t pos)
{
	ssize_t res = -ENODEV;

	mutex_lock(&os_area_flash_mutex);
	if (os_area_flash_ops)
		res = os_area_flash_ops->read(buf, count, pos);
	mutex_unlock(&os_area_flash_mutex);

	return res;
}

static ssize_t os_area_flash_write(const void *buf, size_t count, loff_t pos)
{
	ssize_t res = -ENODEV;

	mutex_lock(&os_area_flash_mutex);
	if (os_area_flash_ops)
		res = os_area_flash_ops->write(buf, count, pos);
	mutex_unlock(&os_area_flash_mutex);

	return res;
}


/**
 * os_area_set_property - Add or overwrite a saved_params value to the device tree.
 *
 * Overwrites an existing property.
 */

static void os_area_set_property(struct device_node *node,
	struct property *prop)
{
	int result;
	struct property *tmp = of_find_property(node, prop->name, NULL);

	if (tmp) {
		pr_debug("%s:%d found %s\n", __func__, __LINE__, prop->name);
		of_remove_property(node, tmp);
	}

	result = of_add_property(node, prop);

	if (result)
		pr_debug("%s:%d of_set_property failed\n", __func__,
			__LINE__);
}

/**
 * os_area_get_property - Get a saved_params value from the device tree.
 *
 */

static void __init os_area_get_property(struct device_node *node,
	struct property *prop)
{
	const struct property *tmp = of_find_property(node, prop->name, NULL);

	if (tmp) {
		BUG_ON(prop->length != tmp->length);
		memcpy(prop->value, tmp->value, prop->length);
	} else
		pr_debug("%s:%d not found %s\n", __func__, __LINE__,
			prop->name);
}

static void dump_field(char *s, const u8 *field, int size_of_field)
{
#if defined(DEBUG)
	int i;

	for (i = 0; i < size_of_field; i++)
		s[i] = isprint(field[i]) ? field[i] : '.';
	s[i] = 0;
#endif
}

#define dump_header(_a) _dump_header(_a, __func__, __LINE__)
static void _dump_header(const struct os_area_header *h, const char *func,
	int line)
{
	char str[sizeof(h->magic_num) + 1];

	dump_field(str, h->magic_num, sizeof(h->magic_num));
	pr_debug("%s:%d: h.magic_num:       '%s'\n", func, line,
		str);
	pr_debug("%s:%d: h.hdr_version:     %u\n", func, line,
		h->hdr_version);
	pr_debug("%s:%d: h.db_area_offset:  %u\n", func, line,
		h->db_area_offset);
	pr_debug("%s:%d: h.ldr_area_offset: %u\n", func, line,
		h->ldr_area_offset);
	pr_debug("%s:%d: h.ldr_format:      %u\n", func, line,
		h->ldr_format);
	pr_debug("%s:%d: h.ldr_size:        %xh\n", func, line,
		h->ldr_size);
}

#define dump_params(_a) _dump_params(_a, __func__, __LINE__)
static void _dump_params(const struct os_area_params *p, const char *func,
	int line)
{
	pr_debug("%s:%d: p.boot_flag:       %u\n", func, line, p->boot_flag);
	pr_debug("%s:%d: p.num_params:      %u\n", func, line, p->num_params);
	pr_debug("%s:%d: p.rtc_diff         %lld\n", func, line, p->rtc_diff);
	pr_debug("%s:%d: p.av_multi_out     %u\n", func, line, p->av_multi_out);
	pr_debug("%s:%d: p.ctrl_button:     %u\n", func, line, p->ctrl_button);
	pr_debug("%s:%d: p.static_ip_addr:  %u.%u.%u.%u\n", func, line,
		p->static_ip_addr[0], p->static_ip_addr[1],
		p->static_ip_addr[2], p->static_ip_addr[3]);
	pr_debug("%s:%d: p.network_mask:    %u.%u.%u.%u\n", func, line,
		p->network_mask[0], p->network_mask[1],
		p->network_mask[2], p->network_mask[3]);
	pr_debug("%s:%d: p.default_gateway: %u.%u.%u.%u\n", func, line,
		p->default_gateway[0], p->default_gateway[1],
		p->default_gateway[2], p->default_gateway[3]);
	pr_debug("%s:%d: p.dns_primary:     %u.%u.%u.%u\n", func, line,
		p->dns_primary[0], p->dns_primary[1],
		p->dns_primary[2], p->dns_primary[3]);
	pr_debug("%s:%d: p.dns_secondary:   %u.%u.%u.%u\n", func, line,
		p->dns_secondary[0], p->dns_secondary[1],
		p->dns_secondary[2], p->dns_secondary[3]);
}

static int verify_header(const struct os_area_header *header)
{
	if (memcmp(header->magic_num, OS_AREA_HEADER_MAGIC_NUM,
		sizeof(header->magic_num))) {
		pr_debug("%s:%d magic_num failed\n", __func__, __LINE__);
		return -1;
	}

	if (header->hdr_version < 1) {
		pr_debug("%s:%d hdr_version failed\n", __func__, __LINE__);
		return -1;
	}

	if (header->db_area_offset > header->ldr_area_offset) {
		pr_debug("%s:%d offsets failed\n", __func__, __LINE__);
		return -1;
	}

	return 0;
}

static int db_verify(const struct os_area_db *db)
{
	if (memcmp(db->magic_num, OS_AREA_DB_MAGIC_NUM,
		sizeof(db->magic_num))) {
		pr_debug("%s:%d magic_num failed\n", __func__, __LINE__);
		return -EINVAL;
	}

	if (db->version != 1) {
		pr_debug("%s:%d version failed\n", __func__, __LINE__);
		return -EINVAL;
	}

	return 0;
}

struct db_index {
       uint8_t owner:5;
       uint8_t key:3;
};

struct db_iterator {
	const struct os_area_db *db;
	struct os_area_db_id match_id;
	struct db_index *idx;
	struct db_index *last_idx;
	union {
		uint64_t *value_64;
		uint32_t *value_32;
		uint16_t *value_16;
	};
};

static unsigned int db_align_up(unsigned int val, unsigned int size)
{
	return (val + (size - 1)) & (~(size - 1));
}

/**
 * db_for_each_64 - Iterator for 64 bit entries.
 *
 * A NULL value for id can be used to match all entries.
 * OS_AREA_DB_OWNER_ANY and OS_AREA_DB_KEY_ANY can be used to match all.
 */

static int db_for_each_64(const struct os_area_db *db,
	const struct os_area_db_id *match_id, struct db_iterator *i)
{
next:
	if (!i->db) {
		i->db = db;
		i->match_id = match_id ? *match_id : os_area_db_id_any;
		i->idx = (void *)db + db->index_64;
		i->last_idx = i->idx + db->count_64;
		i->value_64 = (void *)db + db->index_64
			+ db_align_up(db->count_64, 8);
	} else {
		i->idx++;
		i->value_64++;
	}

	if (i->idx >= i->last_idx) {
		pr_debug("%s:%d: reached end\n", __func__, __LINE__);
		return 0;
	}

	if (i->match_id.owner != OS_AREA_DB_OWNER_ANY
		&& i->match_id.owner != (int)i->idx->owner)
		goto next;
	if (i->match_id.key != OS_AREA_DB_KEY_ANY
		&& i->match_id.key != (int)i->idx->key)
		goto next;

	return 1;
}

static int db_delete_64(struct os_area_db *db, const struct os_area_db_id *id)
{
	struct db_iterator i;

	for (i.db = NULL; db_for_each_64(db, id, &i); ) {

		pr_debug("%s:%d: got (%d:%d) %llxh\n", __func__, __LINE__,
			i.idx->owner, i.idx->key,
			(unsigned long long)*i.value_64);

		i.idx->owner = 0;
		i.idx->key = 0;
		*i.value_64 = 0;
	}
	return 0;
}

static int db_set_64(struct os_area_db *db, const struct os_area_db_id *id,
	uint64_t value)
{
	struct db_iterator i;

	pr_debug("%s:%d: (%d:%d) <= %llxh\n", __func__, __LINE__,
		id->owner, id->key, (unsigned long long)value);

	if (!id->owner || id->owner == OS_AREA_DB_OWNER_ANY
		|| id->key == OS_AREA_DB_KEY_ANY) {
		pr_debug("%s:%d: bad id: (%d:%d)\n", __func__,
			__LINE__, id->owner, id->key);
		return -1;
	}

	db_delete_64(db, id);

	i.db = NULL;
	if (db_for_each_64(db, &os_area_db_id_empty, &i)) {

		pr_debug("%s:%d: got (%d:%d) %llxh\n", __func__, __LINE__,
			i.idx->owner, i.idx->key,
			(unsigned long long)*i.value_64);

		i.idx->owner = id->owner;
		i.idx->key = id->key;
		*i.value_64 = value;

		pr_debug("%s:%d: set (%d:%d) <= %llxh\n", __func__, __LINE__,
			i.idx->owner, i.idx->key,
			(unsigned long long)*i.value_64);
		return 0;
	}
	pr_debug("%s:%d: database full.\n",
		__func__, __LINE__);
	return -1;
}

static int db_get_64(const struct os_area_db *db,
	const struct os_area_db_id *id, uint64_t *value)
{
	struct db_iterator i;

	i.db = NULL;
	if (db_for_each_64(db, id, &i)) {
		*value = *i.value_64;
		pr_debug("%s:%d: found %lld\n", __func__, __LINE__,
				(long long int)*i.value_64);
		return 0;
	}
	pr_debug("%s:%d: not found\n", __func__, __LINE__);
	return -1;
}

static int db_get_rtc_diff(const struct os_area_db *db, int64_t *rtc_diff)
{
	return db_get_64(db, &os_area_db_id_rtc_diff, (uint64_t*)rtc_diff);
}

#define dump_db(a) _dump_db(a, __func__, __LINE__)
static void _dump_db(const struct os_area_db *db, const char *func,
	int line)
{
	char str[sizeof(db->magic_num) + 1];

	dump_field(str, db->magic_num, sizeof(db->magic_num));
	pr_debug("%s:%d: db.magic_num:      '%s'\n", func, line,
		str);
	pr_debug("%s:%d: db.version:         %u\n", func, line,
		db->version);
	pr_debug("%s:%d: db.index_64:        %u\n", func, line,
		db->index_64);
	pr_debug("%s:%d: db.count_64:        %u\n", func, line,
		db->count_64);
	pr_debug("%s:%d: db.index_32:        %u\n", func, line,
		db->index_32);
	pr_debug("%s:%d: db.count_32:        %u\n", func, line,
		db->count_32);
	pr_debug("%s:%d: db.index_16:        %u\n", func, line,
		db->index_16);
	pr_debug("%s:%d: db.count_16:        %u\n", func, line,
		db->count_16);
}

static void os_area_db_init(struct os_area_db *db)
{
	enum {
		HEADER_SIZE = offsetof(struct os_area_db, _db_data),
		INDEX_64_COUNT = 64,
		VALUES_64_COUNT = 57,
		INDEX_32_COUNT = 64,
		VALUES_32_COUNT = 57,
		INDEX_16_COUNT = 64,
		VALUES_16_COUNT = 57,
	};

	memset(db, 0, sizeof(struct os_area_db));

	memcpy(db->magic_num, OS_AREA_DB_MAGIC_NUM, sizeof(db->magic_num));
	db->version = 1;
	db->index_64 = HEADER_SIZE;
	db->count_64 = VALUES_64_COUNT;
	db->index_32 = HEADER_SIZE
			+ INDEX_64_COUNT * sizeof(struct db_index)
			+ VALUES_64_COUNT * sizeof(u64);
	db->count_32 = VALUES_32_COUNT;
	db->index_16 = HEADER_SIZE
			+ INDEX_64_COUNT * sizeof(struct db_index)
			+ VALUES_64_COUNT * sizeof(u64)
			+ INDEX_32_COUNT * sizeof(struct db_index)
			+ VALUES_32_COUNT * sizeof(u32);
	db->count_16 = VALUES_16_COUNT;

	/* Rules to check db layout. */

	BUILD_BUG_ON(sizeof(struct db_index) != 1);
	BUILD_BUG_ON(sizeof(struct os_area_db) != 2 * OS_AREA_SEGMENT_SIZE);
	BUILD_BUG_ON(INDEX_64_COUNT & 0x7);
	BUILD_BUG_ON(VALUES_64_COUNT > INDEX_64_COUNT);
	BUILD_BUG_ON(INDEX_32_COUNT & 0x7);
	BUILD_BUG_ON(VALUES_32_COUNT > INDEX_32_COUNT);
	BUILD_BUG_ON(INDEX_16_COUNT & 0x7);
	BUILD_BUG_ON(VALUES_16_COUNT > INDEX_16_COUNT);
	BUILD_BUG_ON(HEADER_SIZE
			+ INDEX_64_COUNT * sizeof(struct db_index)
			+ VALUES_64_COUNT * sizeof(u64)
			+ INDEX_32_COUNT * sizeof(struct db_index)
			+ VALUES_32_COUNT * sizeof(u32)
			+ INDEX_16_COUNT * sizeof(struct db_index)
			+ VALUES_16_COUNT * sizeof(u16)
			> sizeof(struct os_area_db));
}

/**
 * update_flash_db - Helper for os_area_queue_work_handler.
 *
 */

static int update_flash_db(void)
{
	const unsigned int buf_len = 8 * OS_AREA_SEGMENT_SIZE;
	struct os_area_header *header;
	ssize_t count;
	int error;
	loff_t pos;
	struct os_area_db* db;

	/* Read in header and db from flash. */

	header = kmalloc(buf_len, GFP_KERNEL);
	if (!header) {
		pr_debug("%s: kmalloc failed\n", __func__);
		return -ENOMEM;
	}

	count = os_area_flash_read(header, buf_len, 0);
	if (count < 0) {
		pr_debug("%s: os_area_flash_read failed %zd\n", __func__,
			 count);
		error = count;
		goto fail;
	}

	pos = header->db_area_offset * OS_AREA_SEGMENT_SIZE;
	if (count < OS_AREA_SEGMENT_SIZE || verify_header(header) ||
	    count < pos) {
		pr_debug("%s: verify_header failed\n", __func__);
		dump_header(header);
		error = -EINVAL;
		goto fail;
	}

	/* Now got a good db offset and some maybe good db data. */

	db = (void *)header + pos;

	error = db_verify(db);
	if (error) {
		pr_notice("%s: Verify of flash database failed, formatting.\n",
			  __func__);
		dump_db(db);
		os_area_db_init(db);
	}

	/* Now got good db data. */

	db_set_64(db, &os_area_db_id_rtc_diff, saved_params.rtc_diff);

	count = os_area_flash_write(db, sizeof(struct os_area_db), pos);
	if (count < 0 || count < sizeof(struct os_area_db)) {
		pr_debug("%s: os_area_flash_write failed %zd\n", __func__,
			 count);
		error = count < 0 ? count : -EIO;
	}

fail:
	kfree(header);
	return error;
}

/**
 * os_area_queue_work_handler - Asynchronous write handler.
 *
 * An asynchronous write for flash memory and the device tree.  Do not
 * call directly, use os_area_queue_work().
 */

static void os_area_queue_work_handler(struct work_struct *work)
{
	struct device_node *node;
	int error;

	pr_debug(" -> %s:%d\n", __func__, __LINE__);

	node = of_find_node_by_path("/");
	if (node) {
		os_area_set_property(node, &property_rtc_diff);
		of_node_put(node);
	} else
		pr_debug("%s:%d of_find_node_by_path failed\n",
			__func__, __LINE__);

	error = update_flash_db();
	if (error)
		pr_warn("%s: Could not update FLASH ROM\n", __func__);

	pr_debug(" <- %s:%d\n", __func__, __LINE__);
}

static void os_area_queue_work(void)
{
	static DECLARE_WORK(q, os_area_queue_work_handler);

	wmb();
	schedule_work(&q);
}

/**
 * ps3_os_area_save_params - Copy data from os area mirror to @saved_params.
 *
 * For the convenience of the guest the HV makes a copy of the os area in
 * flash to a high address in the boot memory region and then puts that RAM
 * address and the byte count into the repository for retrieval by the guest.
 * We copy the data we want into a static variable and allow the memory setup
 * by the HV to be claimed by the memblock manager.
 *
 * The os area mirror will not be available to a second stage kernel, and
 * the header verify will fail.  In this case, the saved_params values will
 * be set from flash memory or the passed in device tree in ps3_os_area_init().
 */

void __init ps3_os_area_save_params(void)
{
	int result;
	u64 lpar_addr;
	unsigned int size;
	struct os_area_header *header;
	struct os_area_params *params;
	struct os_area_db *db;

	pr_debug(" -> %s:%d\n", __func__, __LINE__);

	result = ps3_repository_read_boot_dat_info(&lpar_addr, &size);

	if (result) {
		pr_debug("%s:%d ps3_repository_read_boot_dat_info failed\n",
			__func__, __LINE__);
		return;
	}

	header = (struct os_area_header *)__va(lpar_addr);
	params = (struct os_area_params *)__va(lpar_addr
		+ OS_AREA_SEGMENT_SIZE);

	result = verify_header(header);

	if (result) {
		/* Second stage kernels exit here. */
		pr_debug("%s:%d verify_header failed\n", __func__, __LINE__);
		dump_header(header);
		return;
	}

	db = (struct os_area_db *)__va(lpar_addr
		+ header->db_area_offset * OS_AREA_SEGMENT_SIZE);

	dump_header(header);
	dump_params(params);
	dump_db(db);

	result = db_verify(db) || db_get_rtc_diff(db, &saved_params.rtc_diff);
	if (result)
		saved_params.rtc_diff = params->rtc_diff ? params->rtc_diff
			: SECONDS_FROM_1970_TO_2000;
	saved_params.av_multi_out = params->av_multi_out;
	saved_params.valid = 1;

	memset(header, 0, sizeof(*header));

	pr_debug(" <- %s:%d\n", __func__, __LINE__);
}

/**
 * ps3_os_area_init - Setup os area device tree properties as needed.
 */

void __init ps3_os_area_init(void)
{
	struct device_node *node;

	pr_debug(" -> %s:%d\n", __func__, __LINE__);

	node = of_find_node_by_path("/");

	if (!saved_params.valid && node) {
		/* Second stage kernels should have a dt entry. */
		os_area_get_property(node, &property_rtc_diff);
		os_area_get_property(node, &property_av_multi_out);
	}

	if(!saved_params.rtc_diff)
		saved_params.rtc_diff = SECONDS_FROM_1970_TO_2000;

	if (node) {
		os_area_set_property(node, &property_rtc_diff);
		os_area_set_property(node, &property_av_multi_out);
		of_node_put(node);
	} else
		pr_debug("%s:%d of_find_node_by_path failed\n",
			__func__, __LINE__);

	pr_debug(" <- %s:%d\n", __func__, __LINE__);
}

/**
 * ps3_os_area_get_rtc_diff - Returns the rtc diff value.
 */

u64 ps3_os_area_get_rtc_diff(void)
{
	return saved_params.rtc_diff;
}
EXPORT_SYMBOL_GPL(ps3_os_area_get_rtc_diff);

/**
 * ps3_os_area_set_rtc_diff - Set the rtc diff value.
 *
 * An asynchronous write is needed to support writing updates from
 * the timer interrupt context.
 */

void ps3_os_area_set_rtc_diff(u64 rtc_diff)
{
	if (saved_params.rtc_diff != rtc_diff) {
		saved_params.rtc_diff = rtc_diff;
		os_area_queue_work();
	}
}
EXPORT_SYMBOL_GPL(ps3_os_area_set_rtc_diff);

/**
 * ps3_os_area_get_av_multi_out - Returns the default video mode.
 */

enum ps3_param_av_multi_out ps3_os_area_get_av_multi_out(void)
{
    return saved_params.av_multi_out;
}
EXPORT_SYMBOL_GPL(ps3_os_area_get_av_multi_out);