xref: /openbmc/linux/include/linux/mtd/mtd.h (revision 37744fee)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org> et al.
4  */
5 
6 #ifndef __MTD_MTD_H__
7 #define __MTD_MTD_H__
8 
9 #include <linux/types.h>
10 #include <linux/uio.h>
11 #include <linux/list.h>
12 #include <linux/notifier.h>
13 #include <linux/device.h>
14 #include <linux/of.h>
15 #include <linux/nvmem-provider.h>
16 
17 #include <mtd/mtd-abi.h>
18 
19 #include <asm/div64.h>
20 
21 #define MTD_FAIL_ADDR_UNKNOWN -1LL
22 
23 struct mtd_info;
24 
25 /*
26  * If the erase fails, fail_addr might indicate exactly which block failed. If
27  * fail_addr = MTD_FAIL_ADDR_UNKNOWN, the failure was not at the device level
28  * or was not specific to any particular block.
29  */
30 struct erase_info {
31 	uint64_t addr;
32 	uint64_t len;
33 	uint64_t fail_addr;
34 };
35 
36 struct mtd_erase_region_info {
37 	uint64_t offset;		/* At which this region starts, from the beginning of the MTD */
38 	uint32_t erasesize;		/* For this region */
39 	uint32_t numblocks;		/* Number of blocks of erasesize in this region */
40 	unsigned long *lockmap;		/* If keeping bitmap of locks */
41 };
42 
43 /**
44  * struct mtd_oob_ops - oob operation operands
45  * @mode:	operation mode
46  *
47  * @len:	number of data bytes to write/read
48  *
49  * @retlen:	number of data bytes written/read
50  *
51  * @ooblen:	number of oob bytes to write/read
52  * @oobretlen:	number of oob bytes written/read
53  * @ooboffs:	offset of oob data in the oob area (only relevant when
54  *		mode = MTD_OPS_PLACE_OOB or MTD_OPS_RAW)
55  * @datbuf:	data buffer - if NULL only oob data are read/written
56  * @oobbuf:	oob data buffer
57  *
58  * Note, some MTD drivers do not allow you to write more than one OOB area at
59  * one go. If you try to do that on such an MTD device, -EINVAL will be
60  * returned. If you want to make your implementation portable on all kind of MTD
61  * devices you should split the write request into several sub-requests when the
62  * request crosses a page boundary.
63  */
64 struct mtd_oob_ops {
65 	unsigned int	mode;
66 	size_t		len;
67 	size_t		retlen;
68 	size_t		ooblen;
69 	size_t		oobretlen;
70 	uint32_t	ooboffs;
71 	uint8_t		*datbuf;
72 	uint8_t		*oobbuf;
73 };
74 
75 #define MTD_MAX_OOBFREE_ENTRIES_LARGE	32
76 #define MTD_MAX_ECCPOS_ENTRIES_LARGE	640
77 /**
78  * struct mtd_oob_region - oob region definition
79  * @offset: region offset
80  * @length: region length
81  *
82  * This structure describes a region of the OOB area, and is used
83  * to retrieve ECC or free bytes sections.
84  * Each section is defined by an offset within the OOB area and a
85  * length.
86  */
87 struct mtd_oob_region {
88 	u32 offset;
89 	u32 length;
90 };
91 
92 /*
93  * struct mtd_ooblayout_ops - NAND OOB layout operations
94  * @ecc: function returning an ECC region in the OOB area.
95  *	 Should return -ERANGE if %section exceeds the total number of
96  *	 ECC sections.
97  * @free: function returning a free region in the OOB area.
98  *	  Should return -ERANGE if %section exceeds the total number of
99  *	  free sections.
100  */
101 struct mtd_ooblayout_ops {
102 	int (*ecc)(struct mtd_info *mtd, int section,
103 		   struct mtd_oob_region *oobecc);
104 	int (*free)(struct mtd_info *mtd, int section,
105 		    struct mtd_oob_region *oobfree);
106 };
107 
108 /**
109  * struct mtd_pairing_info - page pairing information
110  *
111  * @pair: pair id
112  * @group: group id
113  *
114  * The term "pair" is used here, even though TLC NANDs might group pages by 3
115  * (3 bits in a single cell). A pair should regroup all pages that are sharing
116  * the same cell. Pairs are then indexed in ascending order.
117  *
118  * @group is defining the position of a page in a given pair. It can also be
119  * seen as the bit position in the cell: page attached to bit 0 belongs to
120  * group 0, page attached to bit 1 belongs to group 1, etc.
121  *
122  * Example:
123  * The H27UCG8T2BTR-BC datasheet describes the following pairing scheme:
124  *
125  *		group-0		group-1
126  *
127  *  pair-0	page-0		page-4
128  *  pair-1	page-1		page-5
129  *  pair-2	page-2		page-8
130  *  ...
131  *  pair-127	page-251	page-255
132  *
133  *
134  * Note that the "group" and "pair" terms were extracted from Samsung and
135  * Hynix datasheets, and might be referenced under other names in other
136  * datasheets (Micron is describing this concept as "shared pages").
137  */
138 struct mtd_pairing_info {
139 	int pair;
140 	int group;
141 };
142 
143 /**
144  * struct mtd_pairing_scheme - page pairing scheme description
145  *
146  * @ngroups: number of groups. Should be related to the number of bits
147  *	     per cell.
148  * @get_info: converts a write-unit (page number within an erase block) into
149  *	      mtd_pairing information (pair + group). This function should
150  *	      fill the info parameter based on the wunit index or return
151  *	      -EINVAL if the wunit parameter is invalid.
152  * @get_wunit: converts pairing information into a write-unit (page) number.
153  *	       This function should return the wunit index pointed by the
154  *	       pairing information described in the info argument. It should
155  *	       return -EINVAL, if there's no wunit corresponding to the
156  *	       passed pairing information.
157  *
158  * See mtd_pairing_info documentation for a detailed explanation of the
159  * pair and group concepts.
160  *
161  * The mtd_pairing_scheme structure provides a generic solution to represent
162  * NAND page pairing scheme. Instead of exposing two big tables to do the
163  * write-unit <-> (pair + group) conversions, we ask the MTD drivers to
164  * implement the ->get_info() and ->get_wunit() functions.
165  *
166  * MTD users will then be able to query these information by using the
167  * mtd_pairing_info_to_wunit() and mtd_wunit_to_pairing_info() helpers.
168  *
169  * @ngroups is here to help MTD users iterating over all the pages in a
170  * given pair. This value can be retrieved by MTD users using the
171  * mtd_pairing_groups() helper.
172  *
173  * Examples are given in the mtd_pairing_info_to_wunit() and
174  * mtd_wunit_to_pairing_info() documentation.
175  */
176 struct mtd_pairing_scheme {
177 	int ngroups;
178 	int (*get_info)(struct mtd_info *mtd, int wunit,
179 			struct mtd_pairing_info *info);
180 	int (*get_wunit)(struct mtd_info *mtd,
181 			 const struct mtd_pairing_info *info);
182 };
183 
184 struct module;	/* only needed for owner field in mtd_info */
185 
186 /**
187  * struct mtd_debug_info - debugging information for an MTD device.
188  *
189  * @dfs_dir: direntry object of the MTD device debugfs directory
190  */
191 struct mtd_debug_info {
192 	struct dentry *dfs_dir;
193 
194 	const char *partname;
195 	const char *partid;
196 };
197 
198 /**
199  * struct mtd_part - MTD partition specific fields
200  *
201  * @node: list node used to add an MTD partition to the parent partition list
202  * @offset: offset of the partition relatively to the parent offset
203  * @flags: original flags (before the mtdpart logic decided to tweak them based
204  *	   on flash constraints, like eraseblock/pagesize alignment)
205  *
206  * This struct is embedded in mtd_info and contains partition-specific
207  * properties/fields.
208  */
209 struct mtd_part {
210 	struct list_head node;
211 	u64 offset;
212 	u32 flags;
213 };
214 
215 /**
216  * struct mtd_master - MTD master specific fields
217  *
218  * @partitions_lock: lock protecting accesses to the partition list. Protects
219  *		     not only the master partition list, but also all
220  *		     sub-partitions.
221  * @suspended: et to 1 when the device is suspended, 0 otherwise
222  *
223  * This struct is embedded in mtd_info and contains master-specific
224  * properties/fields. The master is the root MTD device from the MTD partition
225  * point of view.
226  */
227 struct mtd_master {
228 	struct mutex partitions_lock;
229 	unsigned int suspended : 1;
230 };
231 
232 struct mtd_info {
233 	u_char type;
234 	uint32_t flags;
235 	uint64_t size;	 // Total size of the MTD
236 
237 	/* "Major" erase size for the device. Naïve users may take this
238 	 * to be the only erase size available, or may use the more detailed
239 	 * information below if they desire
240 	 */
241 	uint32_t erasesize;
242 	/* Minimal writable flash unit size. In case of NOR flash it is 1 (even
243 	 * though individual bits can be cleared), in case of NAND flash it is
244 	 * one NAND page (or half, or one-fourths of it), in case of ECC-ed NOR
245 	 * it is of ECC block size, etc. It is illegal to have writesize = 0.
246 	 * Any driver registering a struct mtd_info must ensure a writesize of
247 	 * 1 or larger.
248 	 */
249 	uint32_t writesize;
250 
251 	/*
252 	 * Size of the write buffer used by the MTD. MTD devices having a write
253 	 * buffer can write multiple writesize chunks at a time. E.g. while
254 	 * writing 4 * writesize bytes to a device with 2 * writesize bytes
255 	 * buffer the MTD driver can (but doesn't have to) do 2 writesize
256 	 * operations, but not 4. Currently, all NANDs have writebufsize
257 	 * equivalent to writesize (NAND page size). Some NOR flashes do have
258 	 * writebufsize greater than writesize.
259 	 */
260 	uint32_t writebufsize;
261 
262 	uint32_t oobsize;   // Amount of OOB data per block (e.g. 16)
263 	uint32_t oobavail;  // Available OOB bytes per block
264 
265 	/*
266 	 * If erasesize is a power of 2 then the shift is stored in
267 	 * erasesize_shift otherwise erasesize_shift is zero. Ditto writesize.
268 	 */
269 	unsigned int erasesize_shift;
270 	unsigned int writesize_shift;
271 	/* Masks based on erasesize_shift and writesize_shift */
272 	unsigned int erasesize_mask;
273 	unsigned int writesize_mask;
274 
275 	/*
276 	 * read ops return -EUCLEAN if max number of bitflips corrected on any
277 	 * one region comprising an ecc step equals or exceeds this value.
278 	 * Settable by driver, else defaults to ecc_strength.  User can override
279 	 * in sysfs.  N.B. The meaning of the -EUCLEAN return code has changed;
280 	 * see Documentation/ABI/testing/sysfs-class-mtd for more detail.
281 	 */
282 	unsigned int bitflip_threshold;
283 
284 	/* Kernel-only stuff starts here. */
285 	const char *name;
286 	int index;
287 
288 	/* OOB layout description */
289 	const struct mtd_ooblayout_ops *ooblayout;
290 
291 	/* NAND pairing scheme, only provided for MLC/TLC NANDs */
292 	const struct mtd_pairing_scheme *pairing;
293 
294 	/* the ecc step size. */
295 	unsigned int ecc_step_size;
296 
297 	/* max number of correctible bit errors per ecc step */
298 	unsigned int ecc_strength;
299 
300 	/* Data for variable erase regions. If numeraseregions is zero,
301 	 * it means that the whole device has erasesize as given above.
302 	 */
303 	int numeraseregions;
304 	struct mtd_erase_region_info *eraseregions;
305 
306 	/*
307 	 * Do not call via these pointers, use corresponding mtd_*()
308 	 * wrappers instead.
309 	 */
310 	int (*_erase) (struct mtd_info *mtd, struct erase_info *instr);
311 	int (*_point) (struct mtd_info *mtd, loff_t from, size_t len,
312 		       size_t *retlen, void **virt, resource_size_t *phys);
313 	int (*_unpoint) (struct mtd_info *mtd, loff_t from, size_t len);
314 	int (*_read) (struct mtd_info *mtd, loff_t from, size_t len,
315 		      size_t *retlen, u_char *buf);
316 	int (*_write) (struct mtd_info *mtd, loff_t to, size_t len,
317 		       size_t *retlen, const u_char *buf);
318 	int (*_panic_write) (struct mtd_info *mtd, loff_t to, size_t len,
319 			     size_t *retlen, const u_char *buf);
320 	int (*_read_oob) (struct mtd_info *mtd, loff_t from,
321 			  struct mtd_oob_ops *ops);
322 	int (*_write_oob) (struct mtd_info *mtd, loff_t to,
323 			   struct mtd_oob_ops *ops);
324 	int (*_get_fact_prot_info) (struct mtd_info *mtd, size_t len,
325 				    size_t *retlen, struct otp_info *buf);
326 	int (*_read_fact_prot_reg) (struct mtd_info *mtd, loff_t from,
327 				    size_t len, size_t *retlen, u_char *buf);
328 	int (*_get_user_prot_info) (struct mtd_info *mtd, size_t len,
329 				    size_t *retlen, struct otp_info *buf);
330 	int (*_read_user_prot_reg) (struct mtd_info *mtd, loff_t from,
331 				    size_t len, size_t *retlen, u_char *buf);
332 	int (*_write_user_prot_reg) (struct mtd_info *mtd, loff_t to,
333 				     size_t len, size_t *retlen, u_char *buf);
334 	int (*_lock_user_prot_reg) (struct mtd_info *mtd, loff_t from,
335 				    size_t len);
336 	int (*_writev) (struct mtd_info *mtd, const struct kvec *vecs,
337 			unsigned long count, loff_t to, size_t *retlen);
338 	void (*_sync) (struct mtd_info *mtd);
339 	int (*_lock) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
340 	int (*_unlock) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
341 	int (*_is_locked) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
342 	int (*_block_isreserved) (struct mtd_info *mtd, loff_t ofs);
343 	int (*_block_isbad) (struct mtd_info *mtd, loff_t ofs);
344 	int (*_block_markbad) (struct mtd_info *mtd, loff_t ofs);
345 	int (*_max_bad_blocks) (struct mtd_info *mtd, loff_t ofs, size_t len);
346 	int (*_suspend) (struct mtd_info *mtd);
347 	void (*_resume) (struct mtd_info *mtd);
348 	void (*_reboot) (struct mtd_info *mtd);
349 	/*
350 	 * If the driver is something smart, like UBI, it may need to maintain
351 	 * its own reference counting. The below functions are only for driver.
352 	 */
353 	int (*_get_device) (struct mtd_info *mtd);
354 	void (*_put_device) (struct mtd_info *mtd);
355 
356 	/*
357 	 * flag indicates a panic write, low level drivers can take appropriate
358 	 * action if required to ensure writes go through
359 	 */
360 	bool oops_panic_write;
361 
362 	struct notifier_block reboot_notifier;  /* default mode before reboot */
363 
364 	/* ECC status information */
365 	struct mtd_ecc_stats ecc_stats;
366 	/* Subpage shift (NAND) */
367 	int subpage_sft;
368 
369 	void *priv;
370 
371 	struct module *owner;
372 	struct device dev;
373 	int usecount;
374 	struct mtd_debug_info dbg;
375 	struct nvmem_device *nvmem;
376 
377 	/*
378 	 * Parent device from the MTD partition point of view.
379 	 *
380 	 * MTD masters do not have any parent, MTD partitions do. The parent
381 	 * MTD device can itself be a partition.
382 	 */
383 	struct mtd_info *parent;
384 
385 	/* List of partitions attached to this MTD device */
386 	struct list_head partitions;
387 
388 	union {
389 		struct mtd_part part;
390 		struct mtd_master master;
391 	};
392 };
393 
394 static inline struct mtd_info *mtd_get_master(struct mtd_info *mtd)
395 {
396 	while (mtd->parent)
397 		mtd = mtd->parent;
398 
399 	return mtd;
400 }
401 
402 static inline u64 mtd_get_master_ofs(struct mtd_info *mtd, u64 ofs)
403 {
404 	while (mtd->parent) {
405 		ofs += mtd->part.offset;
406 		mtd = mtd->parent;
407 	}
408 
409 	return ofs;
410 }
411 
412 static inline bool mtd_is_partition(const struct mtd_info *mtd)
413 {
414 	return mtd->parent;
415 }
416 
417 static inline bool mtd_has_partitions(const struct mtd_info *mtd)
418 {
419 	return !list_empty(&mtd->partitions);
420 }
421 
422 int mtd_ooblayout_ecc(struct mtd_info *mtd, int section,
423 		      struct mtd_oob_region *oobecc);
424 int mtd_ooblayout_find_eccregion(struct mtd_info *mtd, int eccbyte,
425 				 int *section,
426 				 struct mtd_oob_region *oobregion);
427 int mtd_ooblayout_get_eccbytes(struct mtd_info *mtd, u8 *eccbuf,
428 			       const u8 *oobbuf, int start, int nbytes);
429 int mtd_ooblayout_set_eccbytes(struct mtd_info *mtd, const u8 *eccbuf,
430 			       u8 *oobbuf, int start, int nbytes);
431 int mtd_ooblayout_free(struct mtd_info *mtd, int section,
432 		       struct mtd_oob_region *oobfree);
433 int mtd_ooblayout_get_databytes(struct mtd_info *mtd, u8 *databuf,
434 				const u8 *oobbuf, int start, int nbytes);
435 int mtd_ooblayout_set_databytes(struct mtd_info *mtd, const u8 *databuf,
436 				u8 *oobbuf, int start, int nbytes);
437 int mtd_ooblayout_count_freebytes(struct mtd_info *mtd);
438 int mtd_ooblayout_count_eccbytes(struct mtd_info *mtd);
439 
440 static inline void mtd_set_ooblayout(struct mtd_info *mtd,
441 				     const struct mtd_ooblayout_ops *ooblayout)
442 {
443 	mtd->ooblayout = ooblayout;
444 }
445 
446 static inline void mtd_set_pairing_scheme(struct mtd_info *mtd,
447 				const struct mtd_pairing_scheme *pairing)
448 {
449 	mtd->pairing = pairing;
450 }
451 
452 static inline void mtd_set_of_node(struct mtd_info *mtd,
453 				   struct device_node *np)
454 {
455 	mtd->dev.of_node = np;
456 	if (!mtd->name)
457 		of_property_read_string(np, "label", &mtd->name);
458 }
459 
460 static inline struct device_node *mtd_get_of_node(struct mtd_info *mtd)
461 {
462 	return dev_of_node(&mtd->dev);
463 }
464 
465 static inline u32 mtd_oobavail(struct mtd_info *mtd, struct mtd_oob_ops *ops)
466 {
467 	return ops->mode == MTD_OPS_AUTO_OOB ? mtd->oobavail : mtd->oobsize;
468 }
469 
470 static inline int mtd_max_bad_blocks(struct mtd_info *mtd,
471 				     loff_t ofs, size_t len)
472 {
473 	struct mtd_info *master = mtd_get_master(mtd);
474 
475 	if (!master->_max_bad_blocks)
476 		return -ENOTSUPP;
477 
478 	if (mtd->size < (len + ofs) || ofs < 0)
479 		return -EINVAL;
480 
481 	return master->_max_bad_blocks(master, mtd_get_master_ofs(mtd, ofs),
482 				       len);
483 }
484 
485 int mtd_wunit_to_pairing_info(struct mtd_info *mtd, int wunit,
486 			      struct mtd_pairing_info *info);
487 int mtd_pairing_info_to_wunit(struct mtd_info *mtd,
488 			      const struct mtd_pairing_info *info);
489 int mtd_pairing_groups(struct mtd_info *mtd);
490 int mtd_erase(struct mtd_info *mtd, struct erase_info *instr);
491 int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
492 	      void **virt, resource_size_t *phys);
493 int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len);
494 unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
495 				    unsigned long offset, unsigned long flags);
496 int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
497 	     u_char *buf);
498 int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
499 	      const u_char *buf);
500 int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
501 		    const u_char *buf);
502 
503 int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops);
504 int mtd_write_oob(struct mtd_info *mtd, loff_t to, struct mtd_oob_ops *ops);
505 
506 int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
507 			   struct otp_info *buf);
508 int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
509 			   size_t *retlen, u_char *buf);
510 int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
511 			   struct otp_info *buf);
512 int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
513 			   size_t *retlen, u_char *buf);
514 int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
515 			    size_t *retlen, u_char *buf);
516 int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len);
517 
518 int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
519 	       unsigned long count, loff_t to, size_t *retlen);
520 
521 static inline void mtd_sync(struct mtd_info *mtd)
522 {
523 	struct mtd_info *master = mtd_get_master(mtd);
524 
525 	if (master->_sync)
526 		master->_sync(master);
527 }
528 
529 int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
530 int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
531 int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len);
532 int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs);
533 int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs);
534 int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs);
535 
536 static inline int mtd_suspend(struct mtd_info *mtd)
537 {
538 	struct mtd_info *master = mtd_get_master(mtd);
539 	int ret;
540 
541 	if (master->master.suspended)
542 		return 0;
543 
544 	ret = master->_suspend ? master->_suspend(master) : 0;
545 	if (ret)
546 		return ret;
547 
548 	master->master.suspended = 1;
549 	return 0;
550 }
551 
552 static inline void mtd_resume(struct mtd_info *mtd)
553 {
554 	struct mtd_info *master = mtd_get_master(mtd);
555 
556 	if (!master->master.suspended)
557 		return;
558 
559 	if (master->_resume)
560 		master->_resume(master);
561 
562 	master->master.suspended = 0;
563 }
564 
565 static inline uint32_t mtd_div_by_eb(uint64_t sz, struct mtd_info *mtd)
566 {
567 	if (mtd->erasesize_shift)
568 		return sz >> mtd->erasesize_shift;
569 	do_div(sz, mtd->erasesize);
570 	return sz;
571 }
572 
573 static inline uint32_t mtd_mod_by_eb(uint64_t sz, struct mtd_info *mtd)
574 {
575 	if (mtd->erasesize_shift)
576 		return sz & mtd->erasesize_mask;
577 	return do_div(sz, mtd->erasesize);
578 }
579 
580 /**
581  * mtd_align_erase_req - Adjust an erase request to align things on eraseblock
582  *			 boundaries.
583  * @mtd: the MTD device this erase request applies on
584  * @req: the erase request to adjust
585  *
586  * This function will adjust @req->addr and @req->len to align them on
587  * @mtd->erasesize. Of course we expect @mtd->erasesize to be != 0.
588  */
589 static inline void mtd_align_erase_req(struct mtd_info *mtd,
590 				       struct erase_info *req)
591 {
592 	u32 mod;
593 
594 	if (WARN_ON(!mtd->erasesize))
595 		return;
596 
597 	mod = mtd_mod_by_eb(req->addr, mtd);
598 	if (mod) {
599 		req->addr -= mod;
600 		req->len += mod;
601 	}
602 
603 	mod = mtd_mod_by_eb(req->addr + req->len, mtd);
604 	if (mod)
605 		req->len += mtd->erasesize - mod;
606 }
607 
608 static inline uint32_t mtd_div_by_ws(uint64_t sz, struct mtd_info *mtd)
609 {
610 	if (mtd->writesize_shift)
611 		return sz >> mtd->writesize_shift;
612 	do_div(sz, mtd->writesize);
613 	return sz;
614 }
615 
616 static inline uint32_t mtd_mod_by_ws(uint64_t sz, struct mtd_info *mtd)
617 {
618 	if (mtd->writesize_shift)
619 		return sz & mtd->writesize_mask;
620 	return do_div(sz, mtd->writesize);
621 }
622 
623 static inline int mtd_wunit_per_eb(struct mtd_info *mtd)
624 {
625 	return mtd->erasesize / mtd->writesize;
626 }
627 
628 static inline int mtd_offset_to_wunit(struct mtd_info *mtd, loff_t offs)
629 {
630 	return mtd_div_by_ws(mtd_mod_by_eb(offs, mtd), mtd);
631 }
632 
633 static inline loff_t mtd_wunit_to_offset(struct mtd_info *mtd, loff_t base,
634 					 int wunit)
635 {
636 	return base + (wunit * mtd->writesize);
637 }
638 
639 
640 static inline int mtd_has_oob(const struct mtd_info *mtd)
641 {
642 	struct mtd_info *master = mtd_get_master((struct mtd_info *)mtd);
643 
644 	return master->_read_oob && master->_write_oob;
645 }
646 
647 static inline int mtd_type_is_nand(const struct mtd_info *mtd)
648 {
649 	return mtd->type == MTD_NANDFLASH || mtd->type == MTD_MLCNANDFLASH;
650 }
651 
652 static inline int mtd_can_have_bb(const struct mtd_info *mtd)
653 {
654 	struct mtd_info *master = mtd_get_master((struct mtd_info *)mtd);
655 
656 	return !!master->_block_isbad;
657 }
658 
659 	/* Kernel-side ioctl definitions */
660 
661 struct mtd_partition;
662 struct mtd_part_parser_data;
663 
664 extern int mtd_device_parse_register(struct mtd_info *mtd,
665 				     const char * const *part_probe_types,
666 				     struct mtd_part_parser_data *parser_data,
667 				     const struct mtd_partition *defparts,
668 				     int defnr_parts);
669 #define mtd_device_register(master, parts, nr_parts)	\
670 	mtd_device_parse_register(master, NULL, NULL, parts, nr_parts)
671 extern int mtd_device_unregister(struct mtd_info *master);
672 extern struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num);
673 extern int __get_mtd_device(struct mtd_info *mtd);
674 extern void __put_mtd_device(struct mtd_info *mtd);
675 extern struct mtd_info *get_mtd_device_nm(const char *name);
676 extern void put_mtd_device(struct mtd_info *mtd);
677 
678 
679 struct mtd_notifier {
680 	void (*add)(struct mtd_info *mtd);
681 	void (*remove)(struct mtd_info *mtd);
682 	struct list_head list;
683 };
684 
685 
686 extern void register_mtd_user (struct mtd_notifier *new);
687 extern int unregister_mtd_user (struct mtd_notifier *old);
688 void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size);
689 
690 static inline int mtd_is_bitflip(int err) {
691 	return err == -EUCLEAN;
692 }
693 
694 static inline int mtd_is_eccerr(int err) {
695 	return err == -EBADMSG;
696 }
697 
698 static inline int mtd_is_bitflip_or_eccerr(int err) {
699 	return mtd_is_bitflip(err) || mtd_is_eccerr(err);
700 }
701 
702 unsigned mtd_mmap_capabilities(struct mtd_info *mtd);
703 
704 #endif /* __MTD_MTD_H__ */
705