summaryrefslogtreecommitdiff
path: root/include/linux/mtd/mtd.h
blob: a89955f3cbc88187b8812cd46ba864789f3a582e (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
/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org> et al.
 */

#ifndef __MTD_MTD_H__
#define __MTD_MTD_H__

#include <linux/types.h>
#include <linux/uio.h>
#include <linux/list.h>
#include <linux/notifier.h>
#include <linux/device.h>
#include <linux/of.h>
#include <linux/nvmem-provider.h>

#include <mtd/mtd-abi.h>

#include <asm/div64.h>

#define MTD_FAIL_ADDR_UNKNOWN -1LL

struct mtd_info;

/*
 * If the erase fails, fail_addr might indicate exactly which block failed. If
 * fail_addr = MTD_FAIL_ADDR_UNKNOWN, the failure was not at the device level
 * or was not specific to any particular block.
 */
struct erase_info {
	uint64_t addr;
	uint64_t len;
	uint64_t fail_addr;
};

struct mtd_erase_region_info {
	uint64_t offset;		/* At which this region starts, from the beginning of the MTD */
	uint32_t erasesize;		/* For this region */
	uint32_t numblocks;		/* Number of blocks of erasesize in this region */
	unsigned long *lockmap;		/* If keeping bitmap of locks */
};

/**
 * struct mtd_oob_ops - oob operation operands
 * @mode:	operation mode
 *
 * @len:	number of data bytes to write/read
 *
 * @retlen:	number of data bytes written/read
 *
 * @ooblen:	number of oob bytes to write/read
 * @oobretlen:	number of oob bytes written/read
 * @ooboffs:	offset of oob data in the oob area (only relevant when
 *		mode = MTD_OPS_PLACE_OOB or MTD_OPS_RAW)
 * @datbuf:	data buffer - if NULL only oob data are read/written
 * @oobbuf:	oob data buffer
 *
 * Note, some MTD drivers do not allow you to write more than one OOB area at
 * one go. If you try to do that on such an MTD device, -EINVAL will be
 * returned. If you want to make your implementation portable on all kind of MTD
 * devices you should split the write request into several sub-requests when the
 * request crosses a page boundary.
 */
struct mtd_oob_ops {
	unsigned int	mode;
	size_t		len;
	size_t		retlen;
	size_t		ooblen;
	size_t		oobretlen;
	uint32_t	ooboffs;
	uint8_t		*datbuf;
	uint8_t		*oobbuf;
};

#define MTD_MAX_OOBFREE_ENTRIES_LARGE	32
#define MTD_MAX_ECCPOS_ENTRIES_LARGE	640
/**
 * struct mtd_oob_region - oob region definition
 * @offset: region offset
 * @length: region length
 *
 * This structure describes a region of the OOB area, and is used
 * to retrieve ECC or free bytes sections.
 * Each section is defined by an offset within the OOB area and a
 * length.
 */
struct mtd_oob_region {
	u32 offset;
	u32 length;
};

/*
 * struct mtd_ooblayout_ops - NAND OOB layout operations
 * @ecc: function returning an ECC region in the OOB area.
 *	 Should return -ERANGE if %section exceeds the total number of
 *	 ECC sections.
 * @free: function returning a free region in the OOB area.
 *	  Should return -ERANGE if %section exceeds the total number of
 *	  free sections.
 */
struct mtd_ooblayout_ops {
	int (*ecc)(struct mtd_info *mtd, int section,
		   struct mtd_oob_region *oobecc);
	int (*free)(struct mtd_info *mtd, int section,
		    struct mtd_oob_region *oobfree);
};

/**
 * struct mtd_pairing_info - page pairing information
 *
 * @pair: pair id
 * @group: group id
 *
 * The term "pair" is used here, even though TLC NANDs might group pages by 3
 * (3 bits in a single cell). A pair should regroup all pages that are sharing
 * the same cell. Pairs are then indexed in ascending order.
 *
 * @group is defining the position of a page in a given pair. It can also be
 * seen as the bit position in the cell: page attached to bit 0 belongs to
 * group 0, page attached to bit 1 belongs to group 1, etc.
 *
 * Example:
 * The H27UCG8T2BTR-BC datasheet describes the following pairing scheme:
 *
 *		group-0		group-1
 *
 *  pair-0	page-0		page-4
 *  pair-1	page-1		page-5
 *  pair-2	page-2		page-8
 *  ...
 *  pair-127	page-251	page-255
 *
 *
 * Note that the "group" and "pair" terms were extracted from Samsung and
 * Hynix datasheets, and might be referenced under other names in other
 * datasheets (Micron is describing this concept as "shared pages").
 */
struct mtd_pairing_info {
	int pair;
	int group;
};

/**
 * struct mtd_pairing_scheme - page pairing scheme description
 *
 * @ngroups: number of groups. Should be related to the number of bits
 *	     per cell.
 * @get_info: converts a write-unit (page number within an erase block) into
 *	      mtd_pairing information (pair + group). This function should
 *	      fill the info parameter based on the wunit index or return
 *	      -EINVAL if the wunit parameter is invalid.
 * @get_wunit: converts pairing information into a write-unit (page) number.
 *	       This function should return the wunit index pointed by the
 *	       pairing information described in the info argument. It should
 *	       return -EINVAL, if there's no wunit corresponding to the
 *	       passed pairing information.
 *
 * See mtd_pairing_info documentation for a detailed explanation of the
 * pair and group concepts.
 *
 * The mtd_pairing_scheme structure provides a generic solution to represent
 * NAND page pairing scheme. Instead of exposing two big tables to do the
 * write-unit <-> (pair + group) conversions, we ask the MTD drivers to
 * implement the ->get_info() and ->get_wunit() functions.
 *
 * MTD users will then be able to query these information by using the
 * mtd_pairing_info_to_wunit() and mtd_wunit_to_pairing_info() helpers.
 *
 * @ngroups is here to help MTD users iterating over all the pages in a
 * given pair. This value can be retrieved by MTD users using the
 * mtd_pairing_groups() helper.
 *
 * Examples are given in the mtd_pairing_info_to_wunit() and
 * mtd_wunit_to_pairing_info() documentation.
 */
struct mtd_pairing_scheme {
	int ngroups;
	int (*get_info)(struct mtd_info *mtd, int wunit,
			struct mtd_pairing_info *info);
	int (*get_wunit)(struct mtd_info *mtd,
			 const struct mtd_pairing_info *info);
};

struct module;	/* only needed for owner field in mtd_info */

/**
 * struct mtd_debug_info - debugging information for an MTD device.
 *
 * @dfs_dir: direntry object of the MTD device debugfs directory
 */
struct mtd_debug_info {
	struct dentry *dfs_dir;

	const char *partname;
	const char *partid;
};

/**
 * struct mtd_part - MTD partition specific fields
 *
 * @node: list node used to add an MTD partition to the parent partition list
 * @offset: offset of the partition relatively to the parent offset
 * @size: partition size. Should be equal to mtd->size unless
 *	  MTD_SLC_ON_MLC_EMULATION is set
 * @flags: original flags (before the mtdpart logic decided to tweak them based
 *	   on flash constraints, like eraseblock/pagesize alignment)
 *
 * This struct is embedded in mtd_info and contains partition-specific
 * properties/fields.
 */
struct mtd_part {
	struct list_head node;
	u64 offset;
	u64 size;
	u32 flags;
};

/**
 * struct mtd_master - MTD master specific fields
 *
 * @partitions_lock: lock protecting accesses to the partition list. Protects
 *		     not only the master partition list, but also all
 *		     sub-partitions.
 * @suspended: et to 1 when the device is suspended, 0 otherwise
 *
 * This struct is embedded in mtd_info and contains master-specific
 * properties/fields. The master is the root MTD device from the MTD partition
 * point of view.
 */
struct mtd_master {
	struct mutex partitions_lock;
	struct mutex chrdev_lock;
	unsigned int suspended : 1;
};

struct mtd_info {
	u_char type;
	uint32_t flags;
	uint64_t size;	 // Total size of the MTD

	/* "Major" erase size for the device. Naïve users may take this
	 * to be the only erase size available, or may use the more detailed
	 * information below if they desire
	 */
	uint32_t erasesize;
	/* Minimal writable flash unit size. In case of NOR flash it is 1 (even
	 * though individual bits can be cleared), in case of NAND flash it is
	 * one NAND page (or half, or one-fourths of it), in case of ECC-ed NOR
	 * it is of ECC block size, etc. It is illegal to have writesize = 0.
	 * Any driver registering a struct mtd_info must ensure a writesize of
	 * 1 or larger.
	 */
	uint32_t writesize;

	/*
	 * Size of the write buffer used by the MTD. MTD devices having a write
	 * buffer can write multiple writesize chunks at a time. E.g. while
	 * writing 4 * writesize bytes to a device with 2 * writesize bytes
	 * buffer the MTD driver can (but doesn't have to) do 2 writesize
	 * operations, but not 4. Currently, all NANDs have writebufsize
	 * equivalent to writesize (NAND page size). Some NOR flashes do have
	 * writebufsize greater than writesize.
	 */
	uint32_t writebufsize;

	uint32_t oobsize;   // Amount of OOB data per block (e.g. 16)
	uint32_t oobavail;  // Available OOB bytes per block

	/*
	 * If erasesize is a power of 2 then the shift is stored in
	 * erasesize_shift otherwise erasesize_shift is zero. Ditto writesize.
	 */
	unsigned int erasesize_shift;
	unsigned int writesize_shift;
	/* Masks based on erasesize_shift and writesize_shift */
	unsigned int erasesize_mask;
	unsigned int writesize_mask;

	/*
	 * read ops return -EUCLEAN if max number of bitflips corrected on any
	 * one region comprising an ecc step equals or exceeds this value.
	 * Settable by driver, else defaults to ecc_strength.  User can override
	 * in sysfs.  N.B. The meaning of the -EUCLEAN return code has changed;
	 * see Documentation/ABI/testing/sysfs-class-mtd for more detail.
	 */
	unsigned int bitflip_threshold;

	/* Kernel-only stuff starts here. */
	const char *name;
	int index;

	/* OOB layout description */
	const struct mtd_ooblayout_ops *ooblayout;

	/* NAND pairing scheme, only provided for MLC/TLC NANDs */
	const struct mtd_pairing_scheme *pairing;

	/* the ecc step size. */
	unsigned int ecc_step_size;

	/* max number of correctible bit errors per ecc step */
	unsigned int ecc_strength;

	/* Data for variable erase regions. If numeraseregions is zero,
	 * it means that the whole device has erasesize as given above.
	 */
	int numeraseregions;
	struct mtd_erase_region_info *eraseregions;

	/*
	 * Do not call via these pointers, use corresponding mtd_*()
	 * wrappers instead.
	 */
	int (*_erase) (struct mtd_info *mtd, struct erase_info *instr);
	int (*_point) (struct mtd_info *mtd, loff_t from, size_t len,
		       size_t *retlen, void **virt, resource_size_t *phys);
	int (*_unpoint) (struct mtd_info *mtd, loff_t from, size_t len);
	int (*_read) (struct mtd_info *mtd, loff_t from, size_t len,
		      size_t *retlen, u_char *buf);
	int (*_write) (struct mtd_info *mtd, loff_t to, size_t len,
		       size_t *retlen, const u_char *buf);
	int (*_panic_write) (struct mtd_info *mtd, loff_t to, size_t len,
			     size_t *retlen, const u_char *buf);
	int (*_read_oob) (struct mtd_info *mtd, loff_t from,
			  struct mtd_oob_ops *ops);
	int (*_write_oob) (struct mtd_info *mtd, loff_t to,
			   struct mtd_oob_ops *ops);
	int (*_get_fact_prot_info) (struct mtd_info *mtd, size_t len,
				    size_t *retlen, struct otp_info *buf);
	int (*_read_fact_prot_reg) (struct mtd_info *mtd, loff_t from,
				    size_t len, size_t *retlen, u_char *buf);
	int (*_get_user_prot_info) (struct mtd_info *mtd, size_t len,
				    size_t *retlen, struct otp_info *buf);
	int (*_read_user_prot_reg) (struct mtd_info *mtd, loff_t from,
				    size_t len, size_t *retlen, u_char *buf);
	int (*_write_user_prot_reg) (struct mtd_info *mtd, loff_t to,
				     size_t len, size_t *retlen,
				     const u_char *buf);
	int (*_lock_user_prot_reg) (struct mtd_info *mtd, loff_t from,
				    size_t len);
	int (*_erase_user_prot_reg) (struct mtd_info *mtd, loff_t from,
				     size_t len);
	int (*_writev) (struct mtd_info *mtd, const struct kvec *vecs,
			unsigned long count, loff_t to, size_t *retlen);
	void (*_sync) (struct mtd_info *mtd);
	int (*_lock) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
	int (*_unlock) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
	int (*_is_locked) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
	int (*_block_isreserved) (struct mtd_info *mtd, loff_t ofs);
	int (*_block_isbad) (struct mtd_info *mtd, loff_t ofs);
	int (*_block_markbad) (struct mtd_info *mtd, loff_t ofs);
	int (*_max_bad_blocks) (struct mtd_info *mtd, loff_t ofs, size_t len);
	int (*_suspend) (struct mtd_info *mtd);
	void (*_resume) (struct mtd_info *mtd);
	void (*_reboot) (struct mtd_info *mtd);
	/*
	 * If the driver is something smart, like UBI, it may need to maintain
	 * its own reference counting. The below functions are only for driver.
	 */
	int (*_get_device) (struct mtd_info *mtd);
	void (*_put_device) (struct mtd_info *mtd);

	/*
	 * flag indicates a panic write, low level drivers can take appropriate
	 * action if required to ensure writes go through
	 */
	bool oops_panic_write;

	struct notifier_block reboot_notifier;  /* default mode before reboot */

	/* ECC status information */
	struct mtd_ecc_stats ecc_stats;
	/* Subpage shift (NAND) */
	int subpage_sft;

	void *priv;

	struct module *owner;
	struct device dev;
	int usecount;
	struct mtd_debug_info dbg;
	struct nvmem_device *nvmem;

	/*
	 * Parent device from the MTD partition point of view.
	 *
	 * MTD masters do not have any parent, MTD partitions do. The parent
	 * MTD device can itself be a partition.
	 */
	struct mtd_info *parent;

	/* List of partitions attached to this MTD device */
	struct list_head partitions;

	union {
		struct mtd_part part;
		struct mtd_master master;
	};
};

static inline struct mtd_info *mtd_get_master(struct mtd_info *mtd)
{
	while (mtd->parent)
		mtd = mtd->parent;

	return mtd;
}

static inline u64 mtd_get_master_ofs(struct mtd_info *mtd, u64 ofs)
{
	while (mtd->parent) {
		ofs += mtd->part.offset;
		mtd = mtd->parent;
	}

	return ofs;
}

static inline bool mtd_is_partition(const struct mtd_info *mtd)
{
	return mtd->parent;
}

static inline bool mtd_has_partitions(const struct mtd_info *mtd)
{
	return !list_empty(&mtd->partitions);
}

int mtd_ooblayout_ecc(struct mtd_info *mtd, int section,
		      struct mtd_oob_region *oobecc);
int mtd_ooblayout_find_eccregion(struct mtd_info *mtd, int eccbyte,
				 int *section,
				 struct mtd_oob_region *oobregion);
int mtd_ooblayout_get_eccbytes(struct mtd_info *mtd, u8 *eccbuf,
			       const u8 *oobbuf, int start, int nbytes);
int mtd_ooblayout_set_eccbytes(struct mtd_info *mtd, const u8 *eccbuf,
			       u8 *oobbuf, int start, int nbytes);
int mtd_ooblayout_free(struct mtd_info *mtd, int section,
		       struct mtd_oob_region *oobfree);
int mtd_ooblayout_get_databytes(struct mtd_info *mtd, u8 *databuf,
				const u8 *oobbuf, int start, int nbytes);
int mtd_ooblayout_set_databytes(struct mtd_info *mtd, const u8 *databuf,
				u8 *oobbuf, int start, int nbytes);
int mtd_ooblayout_count_freebytes(struct mtd_info *mtd);
int mtd_ooblayout_count_eccbytes(struct mtd_info *mtd);

static inline void mtd_set_ooblayout(struct mtd_info *mtd,
				     const struct mtd_ooblayout_ops *ooblayout)
{
	mtd->ooblayout = ooblayout;
}

static inline void mtd_set_pairing_scheme(struct mtd_info *mtd,
				const struct mtd_pairing_scheme *pairing)
{
	mtd->pairing = pairing;
}

static inline void mtd_set_of_node(struct mtd_info *mtd,
				   struct device_node *np)
{
	mtd->dev.of_node = np;
	if (!mtd->name)
		of_property_read_string(np, "label", &mtd->name);
}

static inline struct device_node *mtd_get_of_node(struct mtd_info *mtd)
{
	return dev_of_node(&mtd->dev);
}

static inline u32 mtd_oobavail(struct mtd_info *mtd, struct mtd_oob_ops *ops)
{
	return ops->mode == MTD_OPS_AUTO_OOB ? mtd->oobavail : mtd->oobsize;
}

static inline int mtd_max_bad_blocks(struct mtd_info *mtd,
				     loff_t ofs, size_t len)
{
	struct mtd_info *master = mtd_get_master(mtd);

	if (!master->_max_bad_blocks)
		return -ENOTSUPP;

	if (mtd->size < (len + ofs) || ofs < 0)
		return -EINVAL;

	return master->_max_bad_blocks(master, mtd_get_master_ofs(mtd, ofs),
				       len);
}

int mtd_wunit_to_pairing_info(struct mtd_info *mtd, int wunit,
			      struct mtd_pairing_info *info);
int mtd_pairing_info_to_wunit(struct mtd_info *mtd,
			      const struct mtd_pairing_info *info);
int mtd_pairing_groups(struct mtd_info *mtd);
int mtd_erase(struct mtd_info *mtd, struct erase_info *instr);
int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
	      void **virt, resource_size_t *phys);
int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len);
unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
				    unsigned long offset, unsigned long flags);
int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
	     u_char *buf);
int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
	      const u_char *buf);
int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
		    const u_char *buf);

int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops);
int mtd_write_oob(struct mtd_info *mtd, loff_t to, struct mtd_oob_ops *ops);

int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
			   struct otp_info *buf);
int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
			   size_t *retlen, u_char *buf);
int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
			   struct otp_info *buf);
int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
			   size_t *retlen, u_char *buf);
int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
			    size_t *retlen, const u_char *buf);
int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len);
int mtd_erase_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len);

int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
	       unsigned long count, loff_t to, size_t *retlen);

static inline void mtd_sync(struct mtd_info *mtd)
{
	struct mtd_info *master = mtd_get_master(mtd);

	if (master->_sync)
		master->_sync(master);
}

int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len);
int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs);
int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs);
int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs);

static inline int mtd_suspend(struct mtd_info *mtd)
{
	struct mtd_info *master = mtd_get_master(mtd);
	int ret;

	if (master->master.suspended)
		return 0;

	ret = master->_suspend ? master->_suspend(master) : 0;
	if (ret)
		return ret;

	master->master.suspended = 1;
	return 0;
}

static inline void mtd_resume(struct mtd_info *mtd)
{
	struct mtd_info *master = mtd_get_master(mtd);

	if (!master->master.suspended)
		return;

	if (master->_resume)
		master->_resume(master);

	master->master.suspended = 0;
}

static inline uint32_t mtd_div_by_eb(uint64_t sz, struct mtd_info *mtd)
{
	if (mtd->erasesize_shift)
		return sz >> mtd->erasesize_shift;
	do_div(sz, mtd->erasesize);
	return sz;
}

static inline uint32_t mtd_mod_by_eb(uint64_t sz, struct mtd_info *mtd)
{
	if (mtd->erasesize_shift)
		return sz & mtd->erasesize_mask;
	return do_div(sz, mtd->erasesize);
}

/**
 * mtd_align_erase_req - Adjust an erase request to align things on eraseblock
 *			 boundaries.
 * @mtd: the MTD device this erase request applies on
 * @req: the erase request to adjust
 *
 * This function will adjust @req->addr and @req->len to align them on
 * @mtd->erasesize. Of course we expect @mtd->erasesize to be != 0.
 */
static inline void mtd_align_erase_req(struct mtd_info *mtd,
				       struct erase_info *req)
{
	u32 mod;

	if (WARN_ON(!mtd->erasesize))
		return;

	mod = mtd_mod_by_eb(req->addr, mtd);
	if (mod) {
		req->addr -= mod;
		req->len += mod;
	}

	mod = mtd_mod_by_eb(req->addr + req->len, mtd);
	if (mod)
		req->len += mtd->erasesize - mod;
}

static inline uint32_t mtd_div_by_ws(uint64_t sz, struct mtd_info *mtd)
{
	if (mtd->writesize_shift)
		return sz >> mtd->writesize_shift;
	do_div(sz, mtd->writesize);
	return sz;
}

static inline uint32_t mtd_mod_by_ws(uint64_t sz, struct mtd_info *mtd)
{
	if (mtd->writesize_shift)
		return sz & mtd->writesize_mask;
	return do_div(sz, mtd->writesize);
}

static inline int mtd_wunit_per_eb(struct mtd_info *mtd)
{
	struct mtd_info *master = mtd_get_master(mtd);

	return master->erasesize / mtd->writesize;
}

static inline int mtd_offset_to_wunit(struct mtd_info *mtd, loff_t offs)
{
	return mtd_div_by_ws(mtd_mod_by_eb(offs, mtd), mtd);
}

static inline loff_t mtd_wunit_to_offset(struct mtd_info *mtd, loff_t base,
					 int wunit)
{
	return base + (wunit * mtd->writesize);
}


static inline int mtd_has_oob(const struct mtd_info *mtd)
{
	struct mtd_info *master = mtd_get_master((struct mtd_info *)mtd);

	return master->_read_oob && master->_write_oob;
}

static inline int mtd_type_is_nand(const struct mtd_info *mtd)
{
	return mtd->type == MTD_NANDFLASH || mtd->type == MTD_MLCNANDFLASH;
}

static inline int mtd_can_have_bb(const struct mtd_info *mtd)
{
	struct mtd_info *master = mtd_get_master((struct mtd_info *)mtd);

	return !!master->_block_isbad;
}

	/* Kernel-side ioctl definitions */

struct mtd_partition;
struct mtd_part_parser_data;

extern int mtd_device_parse_register(struct mtd_info *mtd,
				     const char * const *part_probe_types,
				     struct mtd_part_parser_data *parser_data,
				     const struct mtd_partition *defparts,
				     int defnr_parts);
#define mtd_device_register(master, parts, nr_parts)	\
	mtd_device_parse_register(master, NULL, NULL, parts, nr_parts)
extern int mtd_device_unregister(struct mtd_info *master);
extern struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num);
extern int __get_mtd_device(struct mtd_info *mtd);
extern void __put_mtd_device(struct mtd_info *mtd);
extern struct mtd_info *get_mtd_device_nm(const char *name);
extern void put_mtd_device(struct mtd_info *mtd);


struct mtd_notifier {
	void (*add)(struct mtd_info *mtd);
	void (*remove)(struct mtd_info *mtd);
	struct list_head list;
};


extern void register_mtd_user (struct mtd_notifier *new);
extern int unregister_mtd_user (struct mtd_notifier *old);
void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size);

static inline int mtd_is_bitflip(int err) {
	return err == -EUCLEAN;
}

static inline int mtd_is_eccerr(int err) {
	return err == -EBADMSG;
}

static inline int mtd_is_bitflip_or_eccerr(int err) {
	return mtd_is_bitflip(err) || mtd_is_eccerr(err);
}

unsigned mtd_mmap_capabilities(struct mtd_info *mtd);

#endif /* __MTD_MTD_H__ */