Bootlin logo

Elixir Cross Referencer

  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
/*
 * Simple MTD partitioning layer
 *
 * Copyright © 2000 Nicolas Pitre <nico@fluxnic.net>
 * Copyright © 2002 Thomas Gleixner <gleixner@linutronix.de>
 * Copyright © 2000-2010 David Woodhouse <dwmw2@infradead.org>
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/kmod.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
#include <linux/err.h>

#include "mtdcore.h"

/* Our partition linked list */
static LIST_HEAD(mtd_partitions);
static DEFINE_MUTEX(mtd_partitions_mutex);

/* Our partition node structure */
struct mtd_part {
	struct mtd_info mtd;
	struct mtd_info *master;
	uint64_t offset;
	struct list_head list;
};

/*
 * Given a pointer to the MTD object in the mtd_part structure, we can retrieve
 * the pointer to that structure with this macro.
 */
#define PART(x)  ((struct mtd_part *)(x))


/*
 * MTD methods which simply translate the effective address and pass through
 * to the _real_ device.
 */

static int part_read(struct mtd_info *mtd, loff_t from, size_t len,
		size_t *retlen, u_char *buf)
{
	struct mtd_part *part = PART(mtd);
	struct mtd_ecc_stats stats;
	int res;

	stats = part->master->ecc_stats;
	res = part->master->_read(part->master, from + part->offset, len,
				  retlen, buf);
	if (unlikely(mtd_is_eccerr(res)))
		mtd->ecc_stats.failed +=
			part->master->ecc_stats.failed - stats.failed;
	else
		mtd->ecc_stats.corrected +=
			part->master->ecc_stats.corrected - stats.corrected;
	return res;
}

static int part_point(struct mtd_info *mtd, loff_t from, size_t len,
		size_t *retlen, void **virt, resource_size_t *phys)
{
	struct mtd_part *part = PART(mtd);

	return part->master->_point(part->master, from + part->offset, len,
				    retlen, virt, phys);
}

static int part_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
{
	struct mtd_part *part = PART(mtd);

	return part->master->_unpoint(part->master, from + part->offset, len);
}

static unsigned long part_get_unmapped_area(struct mtd_info *mtd,
					    unsigned long len,
					    unsigned long offset,
					    unsigned long flags)
{
	struct mtd_part *part = PART(mtd);

	offset += part->offset;
	return part->master->_get_unmapped_area(part->master, len, offset,
						flags);
}

static int part_read_oob(struct mtd_info *mtd, loff_t from,
		struct mtd_oob_ops *ops)
{
	struct mtd_part *part = PART(mtd);
	int res;

	if (from >= mtd->size)
		return -EINVAL;
	if (ops->datbuf && from + ops->len > mtd->size)
		return -EINVAL;

	/*
	 * If OOB is also requested, make sure that we do not read past the end
	 * of this partition.
	 */
	if (ops->oobbuf) {
		size_t len, pages;

		if (ops->mode == MTD_OPS_AUTO_OOB)
			len = mtd->oobavail;
		else
			len = mtd->oobsize;
		pages = mtd_div_by_ws(mtd->size, mtd);
		pages -= mtd_div_by_ws(from, mtd);
		if (ops->ooboffs + ops->ooblen > pages * len)
			return -EINVAL;
	}

	res = part->master->_read_oob(part->master, from + part->offset, ops);
	if (unlikely(res)) {
		if (mtd_is_bitflip(res))
			mtd->ecc_stats.corrected++;
		if (mtd_is_eccerr(res))
			mtd->ecc_stats.failed++;
	}
	return res;
}

static int part_read_user_prot_reg(struct mtd_info *mtd, loff_t from,
		size_t len, size_t *retlen, u_char *buf)
{
	struct mtd_part *part = PART(mtd);
	return part->master->_read_user_prot_reg(part->master, from, len,
						 retlen, buf);
}

static int part_get_user_prot_info(struct mtd_info *mtd,
		struct otp_info *buf, size_t len)
{
	struct mtd_part *part = PART(mtd);
	return part->master->_get_user_prot_info(part->master, buf, len);
}

static int part_read_fact_prot_reg(struct mtd_info *mtd, loff_t from,
		size_t len, size_t *retlen, u_char *buf)
{
	struct mtd_part *part = PART(mtd);
	return part->master->_read_fact_prot_reg(part->master, from, len,
						 retlen, buf);
}

static int part_get_fact_prot_info(struct mtd_info *mtd, struct otp_info *buf,
		size_t len)
{
	struct mtd_part *part = PART(mtd);
	return part->master->_get_fact_prot_info(part->master, buf, len);
}

static int part_write(struct mtd_info *mtd, loff_t to, size_t len,
		size_t *retlen, const u_char *buf)
{
	struct mtd_part *part = PART(mtd);
	return part->master->_write(part->master, to + part->offset, len,
				    retlen, buf);
}

static int part_panic_write(struct mtd_info *mtd, loff_t to, size_t len,
		size_t *retlen, const u_char *buf)
{
	struct mtd_part *part = PART(mtd);
	return part->master->_panic_write(part->master, to + part->offset, len,
					  retlen, buf);
}

static int part_write_oob(struct mtd_info *mtd, loff_t to,
		struct mtd_oob_ops *ops)
{
	struct mtd_part *part = PART(mtd);

	if (to >= mtd->size)
		return -EINVAL;
	if (ops->datbuf && to + ops->len > mtd->size)
		return -EINVAL;
	return part->master->_write_oob(part->master, to + part->offset, ops);
}

static int part_write_user_prot_reg(struct mtd_info *mtd, loff_t from,
		size_t len, size_t *retlen, u_char *buf)
{
	struct mtd_part *part = PART(mtd);
	return part->master->_write_user_prot_reg(part->master, from, len,
						  retlen, buf);
}

static int part_lock_user_prot_reg(struct mtd_info *mtd, loff_t from,
		size_t len)
{
	struct mtd_part *part = PART(mtd);
	return part->master->_lock_user_prot_reg(part->master, from, len);
}

static int part_writev(struct mtd_info *mtd, const struct kvec *vecs,
		unsigned long count, loff_t to, size_t *retlen)
{
	struct mtd_part *part = PART(mtd);
	return part->master->_writev(part->master, vecs, count,
				     to + part->offset, retlen);
}

static int part_erase(struct mtd_info *mtd, struct erase_info *instr)
{
	struct mtd_part *part = PART(mtd);
	int ret;

	instr->addr += part->offset;
	ret = part->master->_erase(part->master, instr);
	if (ret) {
		if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
			instr->fail_addr -= part->offset;
		instr->addr -= part->offset;
	}
	return ret;
}

void mtd_erase_callback(struct erase_info *instr)
{
	if (instr->mtd->_erase == part_erase) {
		struct mtd_part *part = PART(instr->mtd);

		if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
			instr->fail_addr -= part->offset;
		instr->addr -= part->offset;
	}
	if (instr->callback)
		instr->callback(instr);
}
EXPORT_SYMBOL_GPL(mtd_erase_callback);

static int part_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
{
	struct mtd_part *part = PART(mtd);
	return part->master->_lock(part->master, ofs + part->offset, len);
}

static int part_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
{
	struct mtd_part *part = PART(mtd);
	return part->master->_unlock(part->master, ofs + part->offset, len);
}

static int part_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
{
	struct mtd_part *part = PART(mtd);
	return part->master->_is_locked(part->master, ofs + part->offset, len);
}

static void part_sync(struct mtd_info *mtd)
{
	struct mtd_part *part = PART(mtd);
	part->master->_sync(part->master);
}

static int part_suspend(struct mtd_info *mtd)
{
	struct mtd_part *part = PART(mtd);
	return part->master->_suspend(part->master);
}

static void part_resume(struct mtd_info *mtd)
{
	struct mtd_part *part = PART(mtd);
	part->master->_resume(part->master);
}

static int part_block_isbad(struct mtd_info *mtd, loff_t ofs)
{
	struct mtd_part *part = PART(mtd);
	ofs += part->offset;
	return part->master->_block_isbad(part->master, ofs);
}

static int part_block_markbad(struct mtd_info *mtd, loff_t ofs)
{
	struct mtd_part *part = PART(mtd);
	int res;

	ofs += part->offset;
	res = part->master->_block_markbad(part->master, ofs);
	if (!res)
		mtd->ecc_stats.badblocks++;
	return res;
}

static inline void free_partition(struct mtd_part *p)
{
	kfree(p->mtd.name);
	kfree(p);
}

/*
 * This function unregisters and destroy all slave MTD objects which are
 * attached to the given master MTD object.
 */

int del_mtd_partitions(struct mtd_info *master)
{
	struct mtd_part *slave, *next;
	int ret, err = 0;

	mutex_lock(&mtd_partitions_mutex);
	list_for_each_entry_safe(slave, next, &mtd_partitions, list)
		if (slave->master == master) {
			ret = del_mtd_device(&slave->mtd);
			if (ret < 0) {
				err = ret;
				continue;
			}
			list_del(&slave->list);
			free_partition(slave);
		}
	mutex_unlock(&mtd_partitions_mutex);

	return err;
}

static struct mtd_part *allocate_partition(struct mtd_info *master,
			const struct mtd_partition *part, int partno,
			uint64_t cur_offset)
{
	struct mtd_part *slave;
	char *name;

	/* allocate the partition structure */
	slave = kzalloc(sizeof(*slave), GFP_KERNEL);
	name = kstrdup(part->name, GFP_KERNEL);
	if (!name || !slave) {
		printk(KERN_ERR"memory allocation error while creating partitions for \"%s\"\n",
		       master->name);
		kfree(name);
		kfree(slave);
		return ERR_PTR(-ENOMEM);
	}

	/* set up the MTD object for this partition */
	slave->mtd.type = master->type;
	slave->mtd.flags = master->flags & ~part->mask_flags;
	slave->mtd.size = part->size;
	slave->mtd.writesize = master->writesize;
	slave->mtd.writebufsize = master->writebufsize;
	slave->mtd.oobsize = master->oobsize;
	slave->mtd.oobavail = master->oobavail;
	slave->mtd.subpage_sft = master->subpage_sft;

	slave->mtd.name = name;
	slave->mtd.owner = master->owner;
	slave->mtd.backing_dev_info = master->backing_dev_info;

	/* NOTE:  we don't arrange MTDs as a tree; it'd be error-prone
	 * to have the same data be in two different partitions.
	 */
	slave->mtd.dev.parent = master->dev.parent;

	slave->mtd._read = part_read;
	slave->mtd._write = part_write;

	if (master->_panic_write)
		slave->mtd._panic_write = part_panic_write;

	if (master->_point && master->_unpoint) {
		slave->mtd._point = part_point;
		slave->mtd._unpoint = part_unpoint;
	}

	if (master->_get_unmapped_area)
		slave->mtd._get_unmapped_area = part_get_unmapped_area;
	if (master->_read_oob)
		slave->mtd._read_oob = part_read_oob;
	if (master->_write_oob)
		slave->mtd._write_oob = part_write_oob;
	if (master->_read_user_prot_reg)
		slave->mtd._read_user_prot_reg = part_read_user_prot_reg;
	if (master->_read_fact_prot_reg)
		slave->mtd._read_fact_prot_reg = part_read_fact_prot_reg;
	if (master->_write_user_prot_reg)
		slave->mtd._write_user_prot_reg = part_write_user_prot_reg;
	if (master->_lock_user_prot_reg)
		slave->mtd._lock_user_prot_reg = part_lock_user_prot_reg;
	if (master->_get_user_prot_info)
		slave->mtd._get_user_prot_info = part_get_user_prot_info;
	if (master->_get_fact_prot_info)
		slave->mtd._get_fact_prot_info = part_get_fact_prot_info;
	if (master->_sync)
		slave->mtd._sync = part_sync;
	if (!partno && !master->dev.class && master->_suspend &&
	    master->_resume) {
			slave->mtd._suspend = part_suspend;
			slave->mtd._resume = part_resume;
	}
	if (master->_writev)
		slave->mtd._writev = part_writev;
	if (master->_lock)
		slave->mtd._lock = part_lock;
	if (master->_unlock)
		slave->mtd._unlock = part_unlock;
	if (master->_is_locked)
		slave->mtd._is_locked = part_is_locked;
	if (master->_block_isbad)
		slave->mtd._block_isbad = part_block_isbad;
	if (master->_block_markbad)
		slave->mtd._block_markbad = part_block_markbad;
	slave->mtd._erase = part_erase;
	slave->master = master;
	slave->offset = part->offset;

	if (slave->offset == MTDPART_OFS_APPEND)
		slave->offset = cur_offset;
	if (slave->offset == MTDPART_OFS_NXTBLK) {
		slave->offset = cur_offset;
		if (mtd_mod_by_eb(cur_offset, master) != 0) {
			/* Round up to next erasesize */
			slave->offset = (mtd_div_by_eb(cur_offset, master) + 1) * master->erasesize;
			printk(KERN_NOTICE "Moving partition %d: "
			       "0x%012llx -> 0x%012llx\n", partno,
			       (unsigned long long)cur_offset, (unsigned long long)slave->offset);
		}
	}
	if (slave->offset == MTDPART_OFS_RETAIN) {
		slave->offset = cur_offset;
		if (master->size - slave->offset >= slave->mtd.size) {
			slave->mtd.size = master->size - slave->offset
							- slave->mtd.size;
		} else {
			printk(KERN_ERR "mtd partition \"%s\" doesn't have enough space: %#llx < %#llx, disabled\n",
				part->name, master->size - slave->offset,
				slave->mtd.size);
			/* register to preserve ordering */
			goto out_register;
		}
	}
	if (slave->mtd.size == MTDPART_SIZ_FULL)
		slave->mtd.size = master->size - slave->offset;

	printk(KERN_NOTICE "0x%012llx-0x%012llx : \"%s\"\n", (unsigned long long)slave->offset,
		(unsigned long long)(slave->offset + slave->mtd.size), slave->mtd.name);

	/* let's do some sanity checks */
	if (slave->offset >= master->size) {
		/* let's register it anyway to preserve ordering */
		slave->offset = 0;
		slave->mtd.size = 0;
		printk(KERN_ERR"mtd: partition \"%s\" is out of reach -- disabled\n",
			part->name);
		goto out_register;
	}
	if (slave->offset + slave->mtd.size > master->size) {
		slave->mtd.size = master->size - slave->offset;
		printk(KERN_WARNING"mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#llx\n",
			part->name, master->name, (unsigned long long)slave->mtd.size);
	}
	if (master->numeraseregions > 1) {
		/* Deal with variable erase size stuff */
		int i, max = master->numeraseregions;
		u64 end = slave->offset + slave->mtd.size;
		struct mtd_erase_region_info *regions = master->eraseregions;

		/* Find the first erase regions which is part of this
		 * partition. */
		for (i = 0; i < max && regions[i].offset <= slave->offset; i++)
			;
		/* The loop searched for the region _behind_ the first one */
		if (i > 0)
			i--;

		/* Pick biggest erasesize */
		for (; i < max && regions[i].offset < end; i++) {
			if (slave->mtd.erasesize < regions[i].erasesize) {
				slave->mtd.erasesize = regions[i].erasesize;
			}
		}
		BUG_ON(slave->mtd.erasesize == 0);
	} else {
		/* Single erase size */
		slave->mtd.erasesize = master->erasesize;
	}

	if ((slave->mtd.flags & MTD_WRITEABLE) &&
	    mtd_mod_by_eb(slave->offset, &slave->mtd)) {
		/* Doesn't start on a boundary of major erase size */
		/* FIXME: Let it be writable if it is on a boundary of
		 * _minor_ erase size though */
		slave->mtd.flags &= ~MTD_WRITEABLE;
		printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",
			part->name);
	}
	if ((slave->mtd.flags & MTD_WRITEABLE) &&
	    mtd_mod_by_eb(slave->mtd.size, &slave->mtd)) {
		slave->mtd.flags &= ~MTD_WRITEABLE;
		printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
			part->name);
	}

	slave->mtd.ecclayout = master->ecclayout;
	slave->mtd.ecc_step_size = master->ecc_step_size;
	slave->mtd.ecc_strength = master->ecc_strength;
	slave->mtd.bitflip_threshold = master->bitflip_threshold;

	if (master->_block_isbad) {
		uint64_t offs = 0;

		while (offs < slave->mtd.size) {
			if (mtd_block_isbad(master, offs + slave->offset))
				slave->mtd.ecc_stats.badblocks++;
			offs += slave->mtd.erasesize;
		}
	}

out_register:
	return slave;
}

int mtd_add_partition(struct mtd_info *master, const char *name,
		      long long offset, long long length)
{
	struct mtd_partition part;
	struct mtd_part *p, *new;
	uint64_t start, end;
	int ret = 0;

	/* the direct offset is expected */
	if (offset == MTDPART_OFS_APPEND ||
	    offset == MTDPART_OFS_NXTBLK)
		return -EINVAL;

	if (length == MTDPART_SIZ_FULL)
		length = master->size - offset;

	if (length <= 0)
		return -EINVAL;

	part.name = name;
	part.size = length;
	part.offset = offset;
	part.mask_flags = 0;
	part.ecclayout = NULL;

	new = allocate_partition(master, &part, -1, offset);
	if (IS_ERR(new))
		return PTR_ERR(new);

	start = offset;
	end = offset + length;

	mutex_lock(&mtd_partitions_mutex);
	list_for_each_entry(p, &mtd_partitions, list)
		if (p->master == master) {
			if ((start >= p->offset) &&
			    (start < (p->offset + p->mtd.size)))
				goto err_inv;

			if ((end >= p->offset) &&
			    (end < (p->offset + p->mtd.size)))
				goto err_inv;
		}

	list_add(&new->list, &mtd_partitions);
	mutex_unlock(&mtd_partitions_mutex);

	add_mtd_device(&new->mtd);

	return ret;
err_inv:
	mutex_unlock(&mtd_partitions_mutex);
	free_partition(new);
	return -EINVAL;
}
EXPORT_SYMBOL_GPL(mtd_add_partition);

int mtd_del_partition(struct mtd_info *master, int partno)
{
	struct mtd_part *slave, *next;
	int ret = -EINVAL;

	mutex_lock(&mtd_partitions_mutex);
	list_for_each_entry_safe(slave, next, &mtd_partitions, list)
		if ((slave->master == master) &&
		    (slave->mtd.index == partno)) {
			ret = del_mtd_device(&slave->mtd);
			if (ret < 0)
				break;

			list_del(&slave->list);
			free_partition(slave);
			break;
		}
	mutex_unlock(&mtd_partitions_mutex);

	return ret;
}
EXPORT_SYMBOL_GPL(mtd_del_partition);

/*
 * This function, given a master MTD object and a partition table, creates
 * and registers slave MTD objects which are bound to the master according to
 * the partition definitions.
 *
 * We don't register the master, or expect the caller to have done so,
 * for reasons of data integrity.
 */

int add_mtd_partitions(struct mtd_info *master,
		       const struct mtd_partition *parts,
		       int nbparts)
{
	struct mtd_part *slave;
	uint64_t cur_offset = 0;
	int i;

	printk(KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);

	for (i = 0; i < nbparts; i++) {
		slave = allocate_partition(master, parts + i, i, cur_offset);
		if (IS_ERR(slave)) {
			del_mtd_partitions(master);
			return PTR_ERR(slave);
		}

		mutex_lock(&mtd_partitions_mutex);
		list_add(&slave->list, &mtd_partitions);
		mutex_unlock(&mtd_partitions_mutex);

		add_mtd_device(&slave->mtd);

		cur_offset = slave->offset + slave->mtd.size;
	}

	return 0;
}

static DEFINE_SPINLOCK(part_parser_lock);
static LIST_HEAD(part_parsers);

static struct mtd_part_parser *get_partition_parser(const char *name)
{
	struct mtd_part_parser *p, *ret = NULL;

	spin_lock(&part_parser_lock);

	list_for_each_entry(p, &part_parsers, list)
		if (!strcmp(p->name, name) && try_module_get(p->owner)) {
			ret = p;
			break;
		}

	spin_unlock(&part_parser_lock);

	return ret;
}

#define put_partition_parser(p) do { module_put((p)->owner); } while (0)

void register_mtd_parser(struct mtd_part_parser *p)
{
	spin_lock(&part_parser_lock);
	list_add(&p->list, &part_parsers);
	spin_unlock(&part_parser_lock);
}
EXPORT_SYMBOL_GPL(register_mtd_parser);

void deregister_mtd_parser(struct mtd_part_parser *p)
{
	spin_lock(&part_parser_lock);
	list_del(&p->list);
	spin_unlock(&part_parser_lock);
}
EXPORT_SYMBOL_GPL(deregister_mtd_parser);

/*
 * Do not forget to update 'parse_mtd_partitions()' kerneldoc comment if you
 * are changing this array!
 */
static const char * const default_mtd_part_types[] = {
	"cmdlinepart",
	"ofpart",
	NULL
};

/**
 * parse_mtd_partitions - parse MTD partitions
 * @master: the master partition (describes whole MTD device)
 * @types: names of partition parsers to try or %NULL
 * @pparts: array of partitions found is returned here
 * @data: MTD partition parser-specific data
 *
 * This function tries to find partition on MTD device @master. It uses MTD
 * partition parsers, specified in @types. However, if @types is %NULL, then
 * the default list of parsers is used. The default list contains only the
 * "cmdlinepart" and "ofpart" parsers ATM.
 * Note: If there are more then one parser in @types, the kernel only takes the
 * partitions parsed out by the first parser.
 *
 * This function may return:
 * o a negative error code in case of failure
 * o zero if no partitions were found
 * o a positive number of found partitions, in which case on exit @pparts will
 *   point to an array containing this number of &struct mtd_info objects.
 */
int parse_mtd_partitions(struct mtd_info *master, const char *const *types,
			 struct mtd_partition **pparts,
			 struct mtd_part_parser_data *data)
{
	struct mtd_part_parser *parser;
	int ret = 0;

	if (!types)
		types = default_mtd_part_types;

	for ( ; ret <= 0 && *types; types++) {
		parser = get_partition_parser(*types);
		if (!parser && !request_module("%s", *types))
			parser = get_partition_parser(*types);
		if (!parser)
			continue;
		ret = (*parser->parse_fn)(master, pparts, data);
		put_partition_parser(parser);
		if (ret > 0) {
			printk(KERN_NOTICE "%d %s partitions found on MTD device %s\n",
			       ret, parser->name, master->name);
			break;
		}
	}
	return ret;
}

int mtd_is_partition(const struct mtd_info *mtd)
{
	struct mtd_part *part;
	int ispart = 0;

	mutex_lock(&mtd_partitions_mutex);
	list_for_each_entry(part, &mtd_partitions, list)
		if (&part->mtd == mtd) {
			ispart = 1;
			break;
		}
	mutex_unlock(&mtd_partitions_mutex);

	return ispart;
}
EXPORT_SYMBOL_GPL(mtd_is_partition);

/* Returns the size of the entire flash chip */
uint64_t mtd_get_device_size(const struct mtd_info *mtd)
{
	if (!mtd_is_partition(mtd))
		return mtd->size;

	return PART(mtd)->master->size;
}
EXPORT_SYMBOL_GPL(mtd_get_device_size);