Free Electrons

Embedded Linux Experts

   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
 835
 836
 837
 838
 839
 840
 841
 842
 843
 844
 845
 846
 847
 848
 849
 850
 851
 852
 853
 854
 855
 856
 857
 858
 859
 860
 861
 862
 863
 864
 865
 866
 867
 868
 869
 870
 871
 872
 873
 874
 875
 876
 877
 878
 879
 880
 881
 882
 883
 884
 885
 886
 887
 888
 889
 890
 891
 892
 893
 894
 895
 896
 897
 898
 899
 900
 901
 902
 903
 904
 905
 906
 907
 908
 909
 910
 911
 912
 913
 914
 915
 916
 917
 918
 919
 920
 921
 922
 923
 924
 925
 926
 927
 928
 929
 930
 931
 932
 933
 934
 935
 936
 937
 938
 939
 940
 941
 942
 943
 944
 945
 946
 947
 948
 949
 950
 951
 952
 953
 954
 955
 956
 957
 958
 959
 960
 961
 962
 963
 964
 965
 966
 967
 968
 969
 970
 971
 972
 973
 974
 975
 976
 977
 978
 979
 980
 981
 982
 983
 984
 985
 986
 987
 988
 989
 990
 991
 992
 993
 994
 995
 996
 997
 998
 999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
/*
 *  c 2001 PPC 64 Team, IBM Corp
 *
 *      This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 *
 * /dev/nvram driver for PPC64
 *
 * This perhaps should live in drivers/char
 *
 * TODO: Split the /dev/nvram part (that one can use
 *       drivers/char/generic_nvram.c) from the arch & partition
 *       parsing code.
 */

#include <linux/types.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <linux/fcntl.h>
#include <linux/nvram.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/kmsg_dump.h>
#include <linux/pagemap.h>
#include <linux/pstore.h>
#include <linux/zlib.h>
#include <linux/uaccess.h>
#include <asm/nvram.h>
#include <asm/rtas.h>
#include <asm/prom.h>
#include <asm/machdep.h>

#undef DEBUG_NVRAM

#define NVRAM_HEADER_LEN	sizeof(struct nvram_header)
#define NVRAM_BLOCK_LEN		NVRAM_HEADER_LEN

/* If change this size, then change the size of NVNAME_LEN */
struct nvram_header {
	unsigned char signature;
	unsigned char checksum;
	unsigned short length;
	/* Terminating null required only for names < 12 chars. */
	char name[12];
};

struct nvram_partition {
	struct list_head partition;
	struct nvram_header header;
	unsigned int index;
};

static LIST_HEAD(nvram_partitions);

#ifdef CONFIG_PPC_PSERIES
struct nvram_os_partition rtas_log_partition = {
	.name = "ibm,rtas-log",
	.req_size = 2079,
	.min_size = 1055,
	.index = -1,
	.os_partition = true
};
#endif

struct nvram_os_partition oops_log_partition = {
	.name = "lnx,oops-log",
	.req_size = 4000,
	.min_size = 2000,
	.index = -1,
	.os_partition = true
};

static const char *nvram_os_partitions[] = {
#ifdef CONFIG_PPC_PSERIES
	"ibm,rtas-log",
#endif
	"lnx,oops-log",
	NULL
};

static void oops_to_nvram(struct kmsg_dumper *dumper,
			  enum kmsg_dump_reason reason);

static struct kmsg_dumper nvram_kmsg_dumper = {
	.dump = oops_to_nvram
};

/*
 * For capturing and compressing an oops or panic report...

 * big_oops_buf[] holds the uncompressed text we're capturing.
 *
 * oops_buf[] holds the compressed text, preceded by a oops header.
 * oops header has u16 holding the version of oops header (to differentiate
 * between old and new format header) followed by u16 holding the length of
 * the compressed* text (*Or uncompressed, if compression fails.) and u64
 * holding the timestamp. oops_buf[] gets written to NVRAM.
 *
 * oops_log_info points to the header. oops_data points to the compressed text.
 *
 * +- oops_buf
 * |                                   +- oops_data
 * v                                   v
 * +-----------+-----------+-----------+------------------------+
 * | version   | length    | timestamp | text                   |
 * | (2 bytes) | (2 bytes) | (8 bytes) | (oops_data_sz bytes)   |
 * +-----------+-----------+-----------+------------------------+
 * ^
 * +- oops_log_info
 *
 * We preallocate these buffers during init to avoid kmalloc during oops/panic.
 */
static size_t big_oops_buf_sz;
static char *big_oops_buf, *oops_buf;
static char *oops_data;
static size_t oops_data_sz;

/* Compression parameters */
#define COMPR_LEVEL 6
#define WINDOW_BITS 12
#define MEM_LEVEL 4
static struct z_stream_s stream;

#ifdef CONFIG_PSTORE
#ifdef CONFIG_PPC_POWERNV
static struct nvram_os_partition skiboot_partition = {
	.name = "ibm,skiboot",
	.index = -1,
	.os_partition = false
};
#endif

#ifdef CONFIG_PPC_PSERIES
static struct nvram_os_partition of_config_partition = {
	.name = "of-config",
	.index = -1,
	.os_partition = false
};
#endif

static struct nvram_os_partition common_partition = {
	.name = "common",
	.index = -1,
	.os_partition = false
};

static enum pstore_type_id nvram_type_ids[] = {
	PSTORE_TYPE_DMESG,
	PSTORE_TYPE_PPC_COMMON,
	-1,
	-1,
	-1
};
static int read_type;
#endif

/* nvram_write_os_partition
 *
 * We need to buffer the error logs into nvram to ensure that we have
 * the failure information to decode.  If we have a severe error there
 * is no way to guarantee that the OS or the machine is in a state to
 * get back to user land and write the error to disk.  For example if
 * the SCSI device driver causes a Machine Check by writing to a bad
 * IO address, there is no way of guaranteeing that the device driver
 * is in any state that is would also be able to write the error data
 * captured to disk, thus we buffer it in NVRAM for analysis on the
 * next boot.
 *
 * In NVRAM the partition containing the error log buffer will looks like:
 * Header (in bytes):
 * +-----------+----------+--------+------------+------------------+
 * | signature | checksum | length | name       | data             |
 * |0          |1         |2      3|4         15|16        length-1|
 * +-----------+----------+--------+------------+------------------+
 *
 * The 'data' section would look like (in bytes):
 * +--------------+------------+-----------------------------------+
 * | event_logged | sequence # | error log                         |
 * |0            3|4          7|8                  error_log_size-1|
 * +--------------+------------+-----------------------------------+
 *
 * event_logged: 0 if event has not been logged to syslog, 1 if it has
 * sequence #: The unique sequence # for each event. (until it wraps)
 * error log: The error log from event_scan
 */
int nvram_write_os_partition(struct nvram_os_partition *part,
			     char *buff, int length,
			     unsigned int err_type,
			     unsigned int error_log_cnt)
{
	int rc;
	loff_t tmp_index;
	struct err_log_info info;

	if (part->index == -1)
		return -ESPIPE;

	if (length > part->size)
		length = part->size;

	info.error_type = cpu_to_be32(err_type);
	info.seq_num = cpu_to_be32(error_log_cnt);

	tmp_index = part->index;

	rc = ppc_md.nvram_write((char *)&info, sizeof(struct err_log_info),
				&tmp_index);
	if (rc <= 0) {
		pr_err("%s: Failed nvram_write (%d)\n", __func__, rc);
		return rc;
	}

	rc = ppc_md.nvram_write(buff, length, &tmp_index);
	if (rc <= 0) {
		pr_err("%s: Failed nvram_write (%d)\n", __func__, rc);
		return rc;
	}

	return 0;
}

/* nvram_read_partition
 *
 * Reads nvram partition for at most 'length'
 */
int nvram_read_partition(struct nvram_os_partition *part, char *buff,
			 int length, unsigned int *err_type,
			 unsigned int *error_log_cnt)
{
	int rc;
	loff_t tmp_index;
	struct err_log_info info;

	if (part->index == -1)
		return -1;

	if (length > part->size)
		length = part->size;

	tmp_index = part->index;

	if (part->os_partition) {
		rc = ppc_md.nvram_read((char *)&info,
					sizeof(struct err_log_info),
					&tmp_index);
		if (rc <= 0) {
			pr_err("%s: Failed nvram_read (%d)\n", __func__, rc);
			return rc;
		}
	}

	rc = ppc_md.nvram_read(buff, length, &tmp_index);
	if (rc <= 0) {
		pr_err("%s: Failed nvram_read (%d)\n", __func__, rc);
		return rc;
	}

	if (part->os_partition) {
		*error_log_cnt = be32_to_cpu(info.seq_num);
		*err_type = be32_to_cpu(info.error_type);
	}

	return 0;
}

/* nvram_init_os_partition
 *
 * This sets up a partition with an "OS" signature.
 *
 * The general strategy is the following:
 * 1.) If a partition with the indicated name already exists...
 *	- If it's large enough, use it.
 *	- Otherwise, recycle it and keep going.
 * 2.) Search for a free partition that is large enough.
 * 3.) If there's not a free partition large enough, recycle any obsolete
 * OS partitions and try again.
 * 4.) Will first try getting a chunk that will satisfy the requested size.
 * 5.) If a chunk of the requested size cannot be allocated, then try finding
 * a chunk that will satisfy the minum needed.
 *
 * Returns 0 on success, else -1.
 */
int __init nvram_init_os_partition(struct nvram_os_partition *part)
{
	loff_t p;
	int size;

	/* Look for ours */
	p = nvram_find_partition(part->name, NVRAM_SIG_OS, &size);

	/* Found one but too small, remove it */
	if (p && size < part->min_size) {
		pr_info("nvram: Found too small %s partition,"
					" removing it...\n", part->name);
		nvram_remove_partition(part->name, NVRAM_SIG_OS, NULL);
		p = 0;
	}

	/* Create one if we didn't find */
	if (!p) {
		p = nvram_create_partition(part->name, NVRAM_SIG_OS,
					part->req_size, part->min_size);
		if (p == -ENOSPC) {
			pr_info("nvram: No room to create %s partition, "
				"deleting any obsolete OS partitions...\n",
				part->name);
			nvram_remove_partition(NULL, NVRAM_SIG_OS,
					nvram_os_partitions);
			p = nvram_create_partition(part->name, NVRAM_SIG_OS,
					part->req_size, part->min_size);
		}
	}

	if (p <= 0) {
		pr_err("nvram: Failed to find or create %s"
		       " partition, err %d\n", part->name, (int)p);
		return -1;
	}

	part->index = p;
	part->size = nvram_get_partition_size(p) - sizeof(struct err_log_info);

	return 0;
}

/* Derived from logfs_compress() */
static int nvram_compress(const void *in, void *out, size_t inlen,
							size_t outlen)
{
	int err, ret;

	ret = -EIO;
	err = zlib_deflateInit2(&stream, COMPR_LEVEL, Z_DEFLATED, WINDOW_BITS,
						MEM_LEVEL, Z_DEFAULT_STRATEGY);
	if (err != Z_OK)
		goto error;

	stream.next_in = in;
	stream.avail_in = inlen;
	stream.total_in = 0;
	stream.next_out = out;
	stream.avail_out = outlen;
	stream.total_out = 0;

	err = zlib_deflate(&stream, Z_FINISH);
	if (err != Z_STREAM_END)
		goto error;

	err = zlib_deflateEnd(&stream);
	if (err != Z_OK)
		goto error;

	if (stream.total_out >= stream.total_in)
		goto error;

	ret = stream.total_out;
error:
	return ret;
}

/* Compress the text from big_oops_buf into oops_buf. */
static int zip_oops(size_t text_len)
{
	struct oops_log_info *oops_hdr = (struct oops_log_info *)oops_buf;
	int zipped_len = nvram_compress(big_oops_buf, oops_data, text_len,
								oops_data_sz);
	if (zipped_len < 0) {
		pr_err("nvram: compression failed; returned %d\n", zipped_len);
		pr_err("nvram: logging uncompressed oops/panic report\n");
		return -1;
	}
	oops_hdr->version = cpu_to_be16(OOPS_HDR_VERSION);
	oops_hdr->report_length = cpu_to_be16(zipped_len);
	oops_hdr->timestamp = cpu_to_be64(ktime_get_real_seconds());
	return 0;
}

#ifdef CONFIG_PSTORE
static int nvram_pstore_open(struct pstore_info *psi)
{
	/* Reset the iterator to start reading partitions again */
	read_type = -1;
	return 0;
}

/**
 * nvram_pstore_write - pstore write callback for nvram
 * @record:             pstore record to write, with @id to be set
 *
 * Called by pstore_dump() when an oops or panic report is logged in the
 * printk buffer.
 * Returns 0 on successful write.
 */
static int nvram_pstore_write(struct pstore_record *record)
{
	int rc;
	unsigned int err_type = ERR_TYPE_KERNEL_PANIC;
	struct oops_log_info *oops_hdr = (struct oops_log_info *) oops_buf;

	/* part 1 has the recent messages from printk buffer */
	if (record->part > 1 || (record->type != PSTORE_TYPE_DMESG))
		return -1;

	if (clobbering_unread_rtas_event())
		return -1;

	oops_hdr->version = cpu_to_be16(OOPS_HDR_VERSION);
	oops_hdr->report_length = cpu_to_be16(record->size);
	oops_hdr->timestamp = cpu_to_be64(ktime_get_real_seconds());

	if (record->compressed)
		err_type = ERR_TYPE_KERNEL_PANIC_GZ;

	rc = nvram_write_os_partition(&oops_log_partition, oops_buf,
		(int) (sizeof(*oops_hdr) + record->size), err_type,
		record->count);

	if (rc != 0)
		return rc;

	record->id = record->part;
	return 0;
}

/*
 * Reads the oops/panic report, rtas, of-config and common partition.
 * Returns the length of the data we read from each partition.
 * Returns 0 if we've been called before.
 */
static ssize_t nvram_pstore_read(struct pstore_record *record)
{
	struct oops_log_info *oops_hdr;
	unsigned int err_type, id_no, size = 0;
	struct nvram_os_partition *part = NULL;
	char *buff = NULL;
	int sig = 0;
	loff_t p;

	read_type++;

	switch (nvram_type_ids[read_type]) {
	case PSTORE_TYPE_DMESG:
		part = &oops_log_partition;
		record->type = PSTORE_TYPE_DMESG;
		break;
	case PSTORE_TYPE_PPC_COMMON:
		sig = NVRAM_SIG_SYS;
		part = &common_partition;
		record->type = PSTORE_TYPE_PPC_COMMON;
		record->id = PSTORE_TYPE_PPC_COMMON;
		record->time.tv_sec = 0;
		record->time.tv_nsec = 0;
		break;
#ifdef CONFIG_PPC_PSERIES
	case PSTORE_TYPE_PPC_RTAS:
		part = &rtas_log_partition;
		record->type = PSTORE_TYPE_PPC_RTAS;
		record->time.tv_sec = last_rtas_event;
		record->time.tv_nsec = 0;
		break;
	case PSTORE_TYPE_PPC_OF:
		sig = NVRAM_SIG_OF;
		part = &of_config_partition;
		record->type = PSTORE_TYPE_PPC_OF;
		record->id = PSTORE_TYPE_PPC_OF;
		record->time.tv_sec = 0;
		record->time.tv_nsec = 0;
		break;
#endif
#ifdef CONFIG_PPC_POWERNV
	case PSTORE_TYPE_PPC_OPAL:
		sig = NVRAM_SIG_FW;
		part = &skiboot_partition;
		record->type = PSTORE_TYPE_PPC_OPAL;
		record->id = PSTORE_TYPE_PPC_OPAL;
		record->time.tv_sec = 0;
		record->time.tv_nsec = 0;
		break;
#endif
	default:
		return 0;
	}

	if (!part->os_partition) {
		p = nvram_find_partition(part->name, sig, &size);
		if (p <= 0) {
			pr_err("nvram: Failed to find partition %s, "
				"err %d\n", part->name, (int)p);
			return 0;
		}
		part->index = p;
		part->size = size;
	}

	buff = kmalloc(part->size, GFP_KERNEL);

	if (!buff)
		return -ENOMEM;

	if (nvram_read_partition(part, buff, part->size, &err_type, &id_no)) {
		kfree(buff);
		return 0;
	}

	record->count = 0;

	if (part->os_partition)
		record->id = id_no;

	if (nvram_type_ids[read_type] == PSTORE_TYPE_DMESG) {
		size_t length, hdr_size;

		oops_hdr = (struct oops_log_info *)buff;
		if (be16_to_cpu(oops_hdr->version) < OOPS_HDR_VERSION) {
			/* Old format oops header had 2-byte record size */
			hdr_size = sizeof(u16);
			length = be16_to_cpu(oops_hdr->version);
			record->time.tv_sec = 0;
			record->time.tv_nsec = 0;
		} else {
			hdr_size = sizeof(*oops_hdr);
			length = be16_to_cpu(oops_hdr->report_length);
			record->time.tv_sec = be64_to_cpu(oops_hdr->timestamp);
			record->time.tv_nsec = 0;
		}
		record->buf = kmemdup(buff + hdr_size, length, GFP_KERNEL);
		kfree(buff);
		if (record->buf == NULL)
			return -ENOMEM;

		record->ecc_notice_size = 0;
		if (err_type == ERR_TYPE_KERNEL_PANIC_GZ)
			record->compressed = true;
		else
			record->compressed = false;
		return length;
	}

	record->buf = buff;
	return part->size;
}

static struct pstore_info nvram_pstore_info = {
	.owner = THIS_MODULE,
	.name = "nvram",
	.flags = PSTORE_FLAGS_DMESG,
	.open = nvram_pstore_open,
	.read = nvram_pstore_read,
	.write = nvram_pstore_write,
};

static int nvram_pstore_init(void)
{
	int rc = 0;

	if (machine_is(pseries)) {
		nvram_type_ids[2] = PSTORE_TYPE_PPC_RTAS;
		nvram_type_ids[3] = PSTORE_TYPE_PPC_OF;
	} else
		nvram_type_ids[2] = PSTORE_TYPE_PPC_OPAL;

	nvram_pstore_info.buf = oops_data;
	nvram_pstore_info.bufsize = oops_data_sz;

	spin_lock_init(&nvram_pstore_info.buf_lock);

	rc = pstore_register(&nvram_pstore_info);
	if (rc && (rc != -EPERM))
		/* Print error only when pstore.backend == nvram */
		pr_err("nvram: pstore_register() failed, returned %d. "
				"Defaults to kmsg_dump\n", rc);

	return rc;
}
#else
static int nvram_pstore_init(void)
{
	return -1;
}
#endif

void __init nvram_init_oops_partition(int rtas_partition_exists)
{
	int rc;

	rc = nvram_init_os_partition(&oops_log_partition);
	if (rc != 0) {
#ifdef CONFIG_PPC_PSERIES
		if (!rtas_partition_exists) {
			pr_err("nvram: Failed to initialize oops partition!");
			return;
		}
		pr_notice("nvram: Using %s partition to log both"
			" RTAS errors and oops/panic reports\n",
			rtas_log_partition.name);
		memcpy(&oops_log_partition, &rtas_log_partition,
						sizeof(rtas_log_partition));
#else
		pr_err("nvram: Failed to initialize oops partition!");
		return;
#endif
	}
	oops_buf = kmalloc(oops_log_partition.size, GFP_KERNEL);
	if (!oops_buf) {
		pr_err("nvram: No memory for %s partition\n",
						oops_log_partition.name);
		return;
	}
	oops_data = oops_buf + sizeof(struct oops_log_info);
	oops_data_sz = oops_log_partition.size - sizeof(struct oops_log_info);

	rc = nvram_pstore_init();

	if (!rc)
		return;

	/*
	 * Figure compression (preceded by elimination of each line's <n>
	 * severity prefix) will reduce the oops/panic report to at most
	 * 45% of its original size.
	 */
	big_oops_buf_sz = (oops_data_sz * 100) / 45;
	big_oops_buf = kmalloc(big_oops_buf_sz, GFP_KERNEL);
	if (big_oops_buf) {
		stream.workspace =  kmalloc(zlib_deflate_workspacesize(
					WINDOW_BITS, MEM_LEVEL), GFP_KERNEL);
		if (!stream.workspace) {
			pr_err("nvram: No memory for compression workspace; "
				"skipping compression of %s partition data\n",
				oops_log_partition.name);
			kfree(big_oops_buf);
			big_oops_buf = NULL;
		}
	} else {
		pr_err("No memory for uncompressed %s data; "
			"skipping compression\n", oops_log_partition.name);
		stream.workspace = NULL;
	}

	rc = kmsg_dump_register(&nvram_kmsg_dumper);
	if (rc != 0) {
		pr_err("nvram: kmsg_dump_register() failed; returned %d\n", rc);
		kfree(oops_buf);
		kfree(big_oops_buf);
		kfree(stream.workspace);
	}
}

/*
 * This is our kmsg_dump callback, called after an oops or panic report
 * has been written to the printk buffer.  We want to capture as much
 * of the printk buffer as possible.  First, capture as much as we can
 * that we think will compress sufficiently to fit in the lnx,oops-log
 * partition.  If that's too much, go back and capture uncompressed text.
 */
static void oops_to_nvram(struct kmsg_dumper *dumper,
			  enum kmsg_dump_reason reason)
{
	struct oops_log_info *oops_hdr = (struct oops_log_info *)oops_buf;
	static unsigned int oops_count = 0;
	static bool panicking = false;
	static DEFINE_SPINLOCK(lock);
	unsigned long flags;
	size_t text_len;
	unsigned int err_type = ERR_TYPE_KERNEL_PANIC_GZ;
	int rc = -1;

	switch (reason) {
	case KMSG_DUMP_RESTART:
	case KMSG_DUMP_HALT:
	case KMSG_DUMP_POWEROFF:
		/* These are almost always orderly shutdowns. */
		return;
	case KMSG_DUMP_OOPS:
		break;
	case KMSG_DUMP_PANIC:
		panicking = true;
		break;
	case KMSG_DUMP_EMERG:
		if (panicking)
			/* Panic report already captured. */
			return;
		break;
	default:
		pr_err("%s: ignoring unrecognized KMSG_DUMP_* reason %d\n",
		       __func__, (int) reason);
		return;
	}

	if (clobbering_unread_rtas_event())
		return;

	if (!spin_trylock_irqsave(&lock, flags))
		return;

	if (big_oops_buf) {
		kmsg_dump_get_buffer(dumper, false,
				     big_oops_buf, big_oops_buf_sz, &text_len);
		rc = zip_oops(text_len);
	}
	if (rc != 0) {
		kmsg_dump_rewind(dumper);
		kmsg_dump_get_buffer(dumper, false,
				     oops_data, oops_data_sz, &text_len);
		err_type = ERR_TYPE_KERNEL_PANIC;
		oops_hdr->version = cpu_to_be16(OOPS_HDR_VERSION);
		oops_hdr->report_length = cpu_to_be16(text_len);
		oops_hdr->timestamp = cpu_to_be64(ktime_get_real_seconds());
	}

	(void) nvram_write_os_partition(&oops_log_partition, oops_buf,
		(int) (sizeof(*oops_hdr) + text_len), err_type,
		++oops_count);

	spin_unlock_irqrestore(&lock, flags);
}

static loff_t dev_nvram_llseek(struct file *file, loff_t offset, int origin)
{
	if (ppc_md.nvram_size == NULL)
		return -ENODEV;
	return generic_file_llseek_size(file, offset, origin, MAX_LFS_FILESIZE,
					ppc_md.nvram_size());
}


static ssize_t dev_nvram_read(struct file *file, char __user *buf,
			  size_t count, loff_t *ppos)
{
	ssize_t ret;
	char *tmp = NULL;
	ssize_t size;

	if (!ppc_md.nvram_size) {
		ret = -ENODEV;
		goto out;
	}

	size = ppc_md.nvram_size();
	if (size < 0) {
		ret = size;
		goto out;
	}

	if (*ppos >= size) {
		ret = 0;
		goto out;
	}

	count = min_t(size_t, count, size - *ppos);
	count = min(count, PAGE_SIZE);

	tmp = kmalloc(count, GFP_KERNEL);
	if (!tmp) {
		ret = -ENOMEM;
		goto out;
	}

	ret = ppc_md.nvram_read(tmp, count, ppos);
	if (ret <= 0)
		goto out;

	if (copy_to_user(buf, tmp, ret))
		ret = -EFAULT;

out:
	kfree(tmp);
	return ret;

}

static ssize_t dev_nvram_write(struct file *file, const char __user *buf,
			  size_t count, loff_t *ppos)
{
	ssize_t ret;
	char *tmp = NULL;
	ssize_t size;

	ret = -ENODEV;
	if (!ppc_md.nvram_size)
		goto out;

	ret = 0;
	size = ppc_md.nvram_size();
	if (*ppos >= size || size < 0)
		goto out;

	count = min_t(size_t, count, size - *ppos);
	count = min(count, PAGE_SIZE);

	tmp = memdup_user(buf, count);
	if (IS_ERR(tmp)) {
		ret = PTR_ERR(tmp);
		goto out;
	}

	ret = ppc_md.nvram_write(tmp, count, ppos);

	kfree(tmp);
out:
	return ret;
}

static long dev_nvram_ioctl(struct file *file, unsigned int cmd,
			    unsigned long arg)
{
	switch(cmd) {
#ifdef CONFIG_PPC_PMAC
	case OBSOLETE_PMAC_NVRAM_GET_OFFSET:
		printk(KERN_WARNING "nvram: Using obsolete PMAC_NVRAM_GET_OFFSET ioctl\n");
	case IOC_NVRAM_GET_OFFSET: {
		int part, offset;

		if (!machine_is(powermac))
			return -EINVAL;
		if (copy_from_user(&part, (void __user*)arg, sizeof(part)) != 0)
			return -EFAULT;
		if (part < pmac_nvram_OF || part > pmac_nvram_NR)
			return -EINVAL;
		offset = pmac_get_partition(part);
		if (offset < 0)
			return offset;
		if (copy_to_user((void __user*)arg, &offset, sizeof(offset)) != 0)
			return -EFAULT;
		return 0;
	}
#endif /* CONFIG_PPC_PMAC */
	default:
		return -EINVAL;
	}
}

static const struct file_operations nvram_fops = {
	.owner		= THIS_MODULE,
	.llseek		= dev_nvram_llseek,
	.read		= dev_nvram_read,
	.write		= dev_nvram_write,
	.unlocked_ioctl	= dev_nvram_ioctl,
};

static struct miscdevice nvram_dev = {
	NVRAM_MINOR,
	"nvram",
	&nvram_fops
};


#ifdef DEBUG_NVRAM
static void __init nvram_print_partitions(char * label)
{
	struct nvram_partition * tmp_part;
	
	printk(KERN_WARNING "--------%s---------\n", label);
	printk(KERN_WARNING "indx\t\tsig\tchks\tlen\tname\n");
	list_for_each_entry(tmp_part, &nvram_partitions, partition) {
		printk(KERN_WARNING "%4d    \t%02x\t%02x\t%d\t%12.12s\n",
		       tmp_part->index, tmp_part->header.signature,
		       tmp_part->header.checksum, tmp_part->header.length,
		       tmp_part->header.name);
	}
}
#endif


static int __init nvram_write_header(struct nvram_partition * part)
{
	loff_t tmp_index;
	int rc;
	struct nvram_header phead;

	memcpy(&phead, &part->header, NVRAM_HEADER_LEN);
	phead.length = cpu_to_be16(phead.length);

	tmp_index = part->index;
	rc = ppc_md.nvram_write((char *)&phead, NVRAM_HEADER_LEN, &tmp_index);

	return rc;
}


static unsigned char __init nvram_checksum(struct nvram_header *p)
{
	unsigned int c_sum, c_sum2;
	unsigned short *sp = (unsigned short *)p->name; /* assume 6 shorts */
	c_sum = p->signature + p->length + sp[0] + sp[1] + sp[2] + sp[3] + sp[4] + sp[5];

	/* The sum may have spilled into the 3rd byte.  Fold it back. */
	c_sum = ((c_sum & 0xffff) + (c_sum >> 16)) & 0xffff;
	/* The sum cannot exceed 2 bytes.  Fold it into a checksum */
	c_sum2 = (c_sum >> 8) + (c_sum << 8);
	c_sum = ((c_sum + c_sum2) >> 8) & 0xff;
	return c_sum;
}

/*
 * Per the criteria passed via nvram_remove_partition(), should this
 * partition be removed?  1=remove, 0=keep
 */
static int nvram_can_remove_partition(struct nvram_partition *part,
		const char *name, int sig, const char *exceptions[])
{
	if (part->header.signature != sig)
		return 0;
	if (name) {
		if (strncmp(name, part->header.name, 12))
			return 0;
	} else if (exceptions) {
		const char **except;
		for (except = exceptions; *except; except++) {
			if (!strncmp(*except, part->header.name, 12))
				return 0;
		}
	}
	return 1;
}

/**
 * nvram_remove_partition - Remove one or more partitions in nvram
 * @name: name of the partition to remove, or NULL for a
 *        signature only match
 * @sig: signature of the partition(s) to remove
 * @exceptions: When removing all partitions with a matching signature,
 *        leave these alone.
 */

int __init nvram_remove_partition(const char *name, int sig,
						const char *exceptions[])
{
	struct nvram_partition *part, *prev, *tmp;
	int rc;

	list_for_each_entry(part, &nvram_partitions, partition) {
		if (!nvram_can_remove_partition(part, name, sig, exceptions))
			continue;

		/* Make partition a free partition */
		part->header.signature = NVRAM_SIG_FREE;
		memset(part->header.name, 'w', 12);
		part->header.checksum = nvram_checksum(&part->header);
		rc = nvram_write_header(part);
		if (rc <= 0) {
			printk(KERN_ERR "nvram_remove_partition: nvram_write failed (%d)\n", rc);
			return rc;
		}
	}

	/* Merge contiguous ones */
	prev = NULL;
	list_for_each_entry_safe(part, tmp, &nvram_partitions, partition) {
		if (part->header.signature != NVRAM_SIG_FREE) {
			prev = NULL;
			continue;
		}
		if (prev) {
			prev->header.length += part->header.length;
			prev->header.checksum = nvram_checksum(&prev->header);
			rc = nvram_write_header(prev);
			if (rc <= 0) {
				printk(KERN_ERR "nvram_remove_partition: nvram_write failed (%d)\n", rc);
				return rc;
			}
			list_del(&part->partition);
			kfree(part);
		} else
			prev = part;
	}
	
	return 0;
}

/**
 * nvram_create_partition - Create a partition in nvram
 * @name: name of the partition to create
 * @sig: signature of the partition to create
 * @req_size: size of data to allocate in bytes
 * @min_size: minimum acceptable size (0 means req_size)
 *
 * Returns a negative error code or a positive nvram index
 * of the beginning of the data area of the newly created
 * partition. If you provided a min_size smaller than req_size
 * you need to query for the actual size yourself after the
 * call using nvram_partition_get_size().
 */
loff_t __init nvram_create_partition(const char *name, int sig,
				     int req_size, int min_size)
{
	struct nvram_partition *part;
	struct nvram_partition *new_part;
	struct nvram_partition *free_part = NULL;
	static char nv_init_vals[16];
	loff_t tmp_index;
	long size = 0;
	int rc;

	/* Convert sizes from bytes to blocks */
	req_size = _ALIGN_UP(req_size, NVRAM_BLOCK_LEN) / NVRAM_BLOCK_LEN;
	min_size = _ALIGN_UP(min_size, NVRAM_BLOCK_LEN) / NVRAM_BLOCK_LEN;

	/* If no minimum size specified, make it the same as the
	 * requested size
	 */
	if (min_size == 0)
		min_size = req_size;
	if (min_size > req_size)
		return -EINVAL;

	/* Now add one block to each for the header */
	req_size += 1;
	min_size += 1;

	/* Find a free partition that will give us the maximum needed size 
	   If can't find one that will give us the minimum size needed */
	list_for_each_entry(part, &nvram_partitions, partition) {
		if (part->header.signature != NVRAM_SIG_FREE)
			continue;

		if (part->header.length >= req_size) {
			size = req_size;
			free_part = part;
			break;
		}
		if (part->header.length > size &&
		    part->header.length >= min_size) {
			size = part->header.length;
			free_part = part;
		}
	}
	if (!size)
		return -ENOSPC;
	
	/* Create our OS partition */
	new_part = kmalloc(sizeof(*new_part), GFP_KERNEL);
	if (!new_part) {
		pr_err("%s: kmalloc failed\n", __func__);
		return -ENOMEM;
	}

	new_part->index = free_part->index;
	new_part->header.signature = sig;
	new_part->header.length = size;
	strncpy(new_part->header.name, name, 12);
	new_part->header.checksum = nvram_checksum(&new_part->header);

	rc = nvram_write_header(new_part);
	if (rc <= 0) {
		pr_err("%s: nvram_write_header failed (%d)\n", __func__, rc);
		kfree(new_part);
		return rc;
	}
	list_add_tail(&new_part->partition, &free_part->partition);

	/* Adjust or remove the partition we stole the space from */
	if (free_part->header.length > size) {
		free_part->index += size * NVRAM_BLOCK_LEN;
		free_part->header.length -= size;
		free_part->header.checksum = nvram_checksum(&free_part->header);
		rc = nvram_write_header(free_part);
		if (rc <= 0) {
			pr_err("%s: nvram_write_header failed (%d)\n",
			       __func__, rc);
			return rc;
		}
	} else {
		list_del(&free_part->partition);
		kfree(free_part);
	} 

	/* Clear the new partition */
	for (tmp_index = new_part->index + NVRAM_HEADER_LEN;
	     tmp_index <  ((size - 1) * NVRAM_BLOCK_LEN);
	     tmp_index += NVRAM_BLOCK_LEN) {
		rc = ppc_md.nvram_write(nv_init_vals, NVRAM_BLOCK_LEN, &tmp_index);
		if (rc <= 0) {
			pr_err("%s: nvram_write failed (%d)\n",
			       __func__, rc);
			return rc;
		}
	}

	return new_part->index + NVRAM_HEADER_LEN;
}

/**
 * nvram_get_partition_size - Get the data size of an nvram partition
 * @data_index: This is the offset of the start of the data of
 *              the partition. The same value that is returned by
 *              nvram_create_partition().
 */
int nvram_get_partition_size(loff_t data_index)
{
	struct nvram_partition *part;
	
	list_for_each_entry(part, &nvram_partitions, partition) {
		if (part->index + NVRAM_HEADER_LEN == data_index)
			return (part->header.length - 1) * NVRAM_BLOCK_LEN;
	}
	return -1;
}


/**
 * nvram_find_partition - Find an nvram partition by signature and name
 * @name: Name of the partition or NULL for any name
 * @sig: Signature to test against
 * @out_size: if non-NULL, returns the size of the data part of the partition
 */
loff_t nvram_find_partition(const char *name, int sig, int *out_size)
{
	struct nvram_partition *p;

	list_for_each_entry(p, &nvram_partitions, partition) {
		if (p->header.signature == sig &&
		    (!name || !strncmp(p->header.name, name, 12))) {
			if (out_size)
				*out_size = (p->header.length - 1) *
					NVRAM_BLOCK_LEN;
			return p->index + NVRAM_HEADER_LEN;
		}
	}
	return 0;
}

int __init nvram_scan_partitions(void)
{
	loff_t cur_index = 0;
	struct nvram_header phead;
	struct nvram_partition * tmp_part;
	unsigned char c_sum;
	char * header;
	int total_size;
	int err;

	if (ppc_md.nvram_size == NULL || ppc_md.nvram_size() <= 0)
		return -ENODEV;
	total_size = ppc_md.nvram_size();
	
	header = kmalloc(NVRAM_HEADER_LEN, GFP_KERNEL);
	if (!header) {
		printk(KERN_ERR "nvram_scan_partitions: Failed kmalloc\n");
		return -ENOMEM;
	}

	while (cur_index < total_size) {

		err = ppc_md.nvram_read(header, NVRAM_HEADER_LEN, &cur_index);
		if (err != NVRAM_HEADER_LEN) {
			printk(KERN_ERR "nvram_scan_partitions: Error parsing "
			       "nvram partitions\n");
			goto out;
		}

		cur_index -= NVRAM_HEADER_LEN; /* nvram_read will advance us */

		memcpy(&phead, header, NVRAM_HEADER_LEN);

		phead.length = be16_to_cpu(phead.length);

		err = 0;
		c_sum = nvram_checksum(&phead);
		if (c_sum != phead.checksum) {
			printk(KERN_WARNING "WARNING: nvram partition checksum"
			       " was %02x, should be %02x!\n",
			       phead.checksum, c_sum);
			printk(KERN_WARNING "Terminating nvram partition scan\n");
			goto out;
		}
		if (!phead.length) {
			printk(KERN_WARNING "WARNING: nvram corruption "
			       "detected: 0-length partition\n");
			goto out;
		}
		tmp_part = kmalloc(sizeof(struct nvram_partition), GFP_KERNEL);
		err = -ENOMEM;
		if (!tmp_part) {
			printk(KERN_ERR "nvram_scan_partitions: kmalloc failed\n");
			goto out;
		}
		
		memcpy(&tmp_part->header, &phead, NVRAM_HEADER_LEN);
		tmp_part->index = cur_index;
		list_add_tail(&tmp_part->partition, &nvram_partitions);
		
		cur_index += phead.length * NVRAM_BLOCK_LEN;
	}
	err = 0;

#ifdef DEBUG_NVRAM
	nvram_print_partitions("NVRAM Partitions");
#endif

 out:
	kfree(header);
	return err;
}

static int __init nvram_init(void)
{
	int rc;
	
	BUILD_BUG_ON(NVRAM_BLOCK_LEN != 16);

	if (ppc_md.nvram_size == NULL || ppc_md.nvram_size() <= 0)
		return  -ENODEV;

  	rc = misc_register(&nvram_dev);
	if (rc != 0) {
		printk(KERN_ERR "nvram_init: failed to register device\n");
		return rc;
	}
  	
  	return rc;
}
device_initcall(nvram_init);