summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/platforms/pseries/nvram.c
blob: 0cc240b7f694ef3b35c2930d5356a4e4cb39d863 (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
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
/*
 *  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
 */


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

/* Max bytes to read/write in one go */
#define NVRW_CNT 0x20

/*
 * Set oops header version to distinguish between old and new format header.
 * lnx,oops-log partition max size is 4000, header version > 4000 will
 * help in identifying new header.
 */
#define OOPS_HDR_VERSION 5000

static unsigned int nvram_size;
static int nvram_fetch, nvram_store;
static char nvram_buf[NVRW_CNT];	/* assume this is in the first 4GB */
static DEFINE_SPINLOCK(nvram_lock);

struct err_log_info {
	__be32 error_type;
	__be32 seq_num;
};

struct nvram_os_partition {
	const char *name;
	int req_size;	/* desired size, in bytes */
	int min_size;	/* minimum acceptable size (0 means req_size) */
	long size;	/* size of data portion (excluding err_log_info) */
	long index;	/* offset of data portion of partition */
	bool os_partition; /* partition initialized by OS, not FW */
};

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

static 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 *pseries_nvram_os_partitions[] = {
	"ibm,rtas-log",
	"lnx,oops-log",
	NULL
};

struct oops_log_info {
	__be16 version;
	__be16 report_length;
	__be64 timestamp;
} __attribute__((packed));

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
};

/* See clobbering_unread_rtas_event() */
#define NVRAM_RTAS_READ_TIMEOUT 5		/* seconds */
static unsigned long last_unread_rtas_event;	/* timestamp */

/*
 * 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
static struct nvram_os_partition of_config_partition = {
	.name = "of-config",
	.index = -1,
	.os_partition = false
};

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_RTAS,
	PSTORE_TYPE_PPC_OF,
	PSTORE_TYPE_PPC_COMMON,
	-1
};
static int read_type;
static unsigned long last_rtas_event;
#endif

static ssize_t pSeries_nvram_read(char *buf, size_t count, loff_t *index)
{
	unsigned int i;
	unsigned long len;
	int done;
	unsigned long flags;
	char *p = buf;


	if (nvram_size == 0 || nvram_fetch == RTAS_UNKNOWN_SERVICE)
		return -ENODEV;

	if (*index >= nvram_size)
		return 0;

	i = *index;
	if (i + count > nvram_size)
		count = nvram_size - i;

	spin_lock_irqsave(&nvram_lock, flags);

	for (; count != 0; count -= len) {
		len = count;
		if (len > NVRW_CNT)
			len = NVRW_CNT;
		
		if ((rtas_call(nvram_fetch, 3, 2, &done, i, __pa(nvram_buf),
			       len) != 0) || len != done) {
			spin_unlock_irqrestore(&nvram_lock, flags);
			return -EIO;
		}
		
		memcpy(p, nvram_buf, len);

		p += len;
		i += len;
	}

	spin_unlock_irqrestore(&nvram_lock, flags);
	
	*index = i;
	return p - buf;
}

static ssize_t pSeries_nvram_write(char *buf, size_t count, loff_t *index)
{
	unsigned int i;
	unsigned long len;
	int done;
	unsigned long flags;
	const char *p = buf;

	if (nvram_size == 0 || nvram_store == RTAS_UNKNOWN_SERVICE)
		return -ENODEV;

	if (*index >= nvram_size)
		return 0;

	i = *index;
	if (i + count > nvram_size)
		count = nvram_size - i;

	spin_lock_irqsave(&nvram_lock, flags);

	for (; count != 0; count -= len) {
		len = count;
		if (len > NVRW_CNT)
			len = NVRW_CNT;

		memcpy(nvram_buf, p, len);

		if ((rtas_call(nvram_store, 3, 2, &done, i, __pa(nvram_buf),
			       len) != 0) || len != done) {
			spin_unlock_irqrestore(&nvram_lock, flags);
			return -EIO;
		}
		
		p += len;
		i += len;
	}
	spin_unlock_irqrestore(&nvram_lock, flags);
	
	*index = i;
	return p - buf;
}

static ssize_t pSeries_nvram_get_size(void)
{
	return nvram_size ? nvram_size : -ENODEV;
}


/* nvram_write_os_partition, nvram_write_error_log
 *
 * 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;
}

int nvram_write_error_log(char * buff, int length,
                          unsigned int err_type, unsigned int error_log_cnt)
{
	int rc = nvram_write_os_partition(&rtas_log_partition, buff, length,
						err_type, error_log_cnt);
	if (!rc) {
		last_unread_rtas_event = get_seconds();
#ifdef CONFIG_PSTORE
		last_rtas_event = get_seconds();
#endif
	}

	return rc;
}

/* 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_read_error_log
 *
 * Reads nvram for error log for at most 'length'
 */
int nvram_read_error_log(char *buff, int length,
			unsigned int *err_type, unsigned int *error_log_cnt)
{
	return nvram_read_partition(&rtas_log_partition, buff, length,
						err_type, error_log_cnt);
}

/* This doesn't actually zero anything, but it sets the event_logged
 * word to tell that this event is safely in syslog.
 */
int nvram_clear_error_log(void)
{
	loff_t tmp_index;
	int clear_word = ERR_FLAG_ALREADY_LOGGED;
	int rc;

	if (rtas_log_partition.index == -1)
		return -1;

	tmp_index = rtas_log_partition.index;
	
	rc = ppc_md.nvram_write((char *)&clear_word, sizeof(int), &tmp_index);
	if (rc <= 0) {
		printk(KERN_ERR "nvram_clear_error_log: Failed nvram_write (%d)\n", rc);
		return rc;
	}
	last_unread_rtas_event = 0;

	return 0;
}

/* pseries_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.
 */
static int __init pseries_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,
						pseries_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;
}

/*
 * Are we using the ibm,rtas-log for oops/panic reports?  And if so,
 * would logging this oops/panic overwrite an RTAS event that rtas_errd
 * hasn't had a chance to read and process?  Return 1 if so, else 0.
 *
 * We assume that if rtas_errd hasn't read the RTAS event in
 * NVRAM_RTAS_READ_TIMEOUT seconds, it's probably not going to.
 */
static int clobbering_unread_rtas_event(void)
{
	return (oops_log_partition.index == rtas_log_partition.index
		&& last_unread_rtas_event
		&& get_seconds() - last_unread_rtas_event <=
						NVRAM_RTAS_READ_TIMEOUT);
}

/* 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(get_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
 * @type:               Type of message logged
 * @reason:             reason behind dump (oops/panic)
 * @id:                 identifier to indicate the write performed
 * @part:               pstore writes data to registered buffer in parts,
 *                      part number will indicate the same.
 * @count:              Indicates oops count
 * @compressed:         Flag to indicate the log is compressed
 * @size:               number of bytes written to the registered buffer
 * @psi:                registered pstore_info structure
 *
 * 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(enum pstore_type_id type,
				enum kmsg_dump_reason reason,
				u64 *id, unsigned int part, int count,
				bool compressed, size_t size,
				struct pstore_info *psi)
{
	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 (part > 1 || type != PSTORE_TYPE_DMESG ||
				clobbering_unread_rtas_event())
		return -1;

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

	if (compressed)
		err_type = ERR_TYPE_KERNEL_PANIC_GZ;

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

	if (rc != 0)
		return rc;

	*id = 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(u64 *id, enum pstore_type_id *type,
				int *count, struct timespec *time, char **buf,
				bool *compressed, struct pstore_info *psi)
{
	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;
		*type = PSTORE_TYPE_DMESG;
		break;
	case PSTORE_TYPE_PPC_RTAS:
		part = &rtas_log_partition;
		*type = PSTORE_TYPE_PPC_RTAS;
		time->tv_sec = last_rtas_event;
		time->tv_nsec = 0;
		break;
	case PSTORE_TYPE_PPC_OF:
		sig = NVRAM_SIG_OF;
		part = &of_config_partition;
		*type = PSTORE_TYPE_PPC_OF;
		*id = PSTORE_TYPE_PPC_OF;
		time->tv_sec = 0;
		time->tv_nsec = 0;
		break;
	case PSTORE_TYPE_PPC_COMMON:
		sig = NVRAM_SIG_SYS;
		part = &common_partition;
		*type = PSTORE_TYPE_PPC_COMMON;
		*id = PSTORE_TYPE_PPC_COMMON;
		time->tv_sec = 0;
		time->tv_nsec = 0;
		break;
	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;
	}

	*count = 0;

	if (part->os_partition)
		*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);
			time->tv_sec = 0;
			time->tv_nsec = 0;
		} else {
			hdr_size = sizeof(*oops_hdr);
			length = be16_to_cpu(oops_hdr->report_length);
			time->tv_sec = be64_to_cpu(oops_hdr->timestamp);
			time->tv_nsec = 0;
		}
		*buf = kmalloc(length, GFP_KERNEL);
		if (*buf == NULL)
			return -ENOMEM;
		memcpy(*buf, buff + hdr_size, length);
		kfree(buff);

		if (err_type == ERR_TYPE_KERNEL_PANIC_GZ)
			*compressed = true;
		else
			*compressed = false;
		return length;
	}

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

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

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

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

	rc = pstore_register(&nvram_pstore_info);
	if (rc != 0)
		pr_err("nvram: pstore_register() failed, defaults to "
				"kmsg_dump; returned %d\n", rc);

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

static void __init nvram_init_oops_partition(int rtas_partition_exists)
{
	int rc;

	rc = pseries_nvram_init_os_partition(&oops_log_partition);
	if (rc != 0) {
		if (!rtas_partition_exists)
			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));
	}
	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);
	}
}

static int __init pseries_nvram_init_log_partitions(void)
{
	int rc;

	/* Scan nvram for partitions */
	nvram_scan_partitions();

	rc = pseries_nvram_init_os_partition(&rtas_log_partition);
	nvram_init_oops_partition(rc == 0);
	return 0;
}
machine_arch_initcall(pseries, pseries_nvram_init_log_partitions);

int __init pSeries_nvram_init(void)
{
	struct device_node *nvram;
	const __be32 *nbytes_p;
	unsigned int proplen;

	nvram = of_find_node_by_type(NULL, "nvram");
	if (nvram == NULL)
		return -ENODEV;

	nbytes_p = of_get_property(nvram, "#bytes", &proplen);
	if (nbytes_p == NULL || proplen != sizeof(unsigned int)) {
		of_node_put(nvram);
		return -EIO;
	}

	nvram_size = be32_to_cpup(nbytes_p);

	nvram_fetch = rtas_token("nvram-fetch");
	nvram_store = rtas_token("nvram-store");
	printk(KERN_INFO "PPC64 nvram contains %d bytes\n", nvram_size);
	of_node_put(nvram);

	ppc_md.nvram_read	= pSeries_nvram_read;
	ppc_md.nvram_write	= pSeries_nvram_write;
	ppc_md.nvram_size	= pSeries_nvram_get_size;

	return 0;
}


/*
 * 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(get_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);
}
OpenPOWER on IntegriCloud