xref: /linux/include/linux/mtd/mtd.h (revision 4494ce4fb4ff42946f48bbc8a5ac55ee18dca600)
1 /*
2  * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org> et al.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
17  *
18  */
19 
20 #ifndef __MTD_MTD_H__
21 #define __MTD_MTD_H__
22 
23 #include <linux/types.h>
24 #include <linux/uio.h>
25 #include <linux/notifier.h>
26 #include <linux/device.h>
27 #include <linux/of.h>
28 
29 #include <mtd/mtd-abi.h>
30 
31 #include <asm/div64.h>
32 
33 #define MTD_FAIL_ADDR_UNKNOWN -1LL
34 
35 struct mtd_info;
36 
37 /*
38  * If the erase fails, fail_addr might indicate exactly which block failed. If
39  * fail_addr = MTD_FAIL_ADDR_UNKNOWN, the failure was not at the device level
40  * or was not specific to any particular block.
41  */
42 struct erase_info {
43 	uint64_t addr;
44 	uint64_t len;
45 	uint64_t fail_addr;
46 };
47 
48 struct mtd_erase_region_info {
49 	uint64_t offset;		/* At which this region starts, from the beginning of the MTD */
50 	uint32_t erasesize;		/* For this region */
51 	uint32_t numblocks;		/* Number of blocks of erasesize in this region */
52 	unsigned long *lockmap;		/* If keeping bitmap of locks */
53 };
54 
55 /**
56  * struct mtd_oob_ops - oob operation operands
57  * @mode:	operation mode
58  *
59  * @len:	number of data bytes to write/read
60  *
61  * @retlen:	number of data bytes written/read
62  *
63  * @ooblen:	number of oob bytes to write/read
64  * @oobretlen:	number of oob bytes written/read
65  * @ooboffs:	offset of oob data in the oob area (only relevant when
66  *		mode = MTD_OPS_PLACE_OOB or MTD_OPS_RAW)
67  * @datbuf:	data buffer - if NULL only oob data are read/written
68  * @oobbuf:	oob data buffer
69  *
70  * Note, some MTD drivers do not allow you to write more than one OOB area at
71  * one go. If you try to do that on such an MTD device, -EINVAL will be
72  * returned. If you want to make your implementation portable on all kind of MTD
73  * devices you should split the write request into several sub-requests when the
74  * request crosses a page boundary.
75  */
76 struct mtd_oob_ops {
77 	unsigned int	mode;
78 	size_t		len;
79 	size_t		retlen;
80 	size_t		ooblen;
81 	size_t		oobretlen;
82 	uint32_t	ooboffs;
83 	uint8_t		*datbuf;
84 	uint8_t		*oobbuf;
85 };
86 
87 #define MTD_MAX_OOBFREE_ENTRIES_LARGE	32
88 #define MTD_MAX_ECCPOS_ENTRIES_LARGE	640
89 /**
90  * struct mtd_oob_region - oob region definition
91  * @offset: region offset
92  * @length: region length
93  *
94  * This structure describes a region of the OOB area, and is used
95  * to retrieve ECC or free bytes sections.
96  * Each section is defined by an offset within the OOB area and a
97  * length.
98  */
99 struct mtd_oob_region {
100 	u32 offset;
101 	u32 length;
102 };
103 
104 /*
105  * struct mtd_ooblayout_ops - NAND OOB layout operations
106  * @ecc: function returning an ECC region in the OOB area.
107  *	 Should return -ERANGE if %section exceeds the total number of
108  *	 ECC sections.
109  * @free: function returning a free region in the OOB area.
110  *	  Should return -ERANGE if %section exceeds the total number of
111  *	  free sections.
112  */
113 struct mtd_ooblayout_ops {
114 	int (*ecc)(struct mtd_info *mtd, int section,
115 		   struct mtd_oob_region *oobecc);
116 	int (*free)(struct mtd_info *mtd, int section,
117 		    struct mtd_oob_region *oobfree);
118 };
119 
120 /**
121  * struct mtd_pairing_info - page pairing information
122  *
123  * @pair: pair id
124  * @group: group id
125  *
126  * The term "pair" is used here, even though TLC NANDs might group pages by 3
127  * (3 bits in a single cell). A pair should regroup all pages that are sharing
128  * the same cell. Pairs are then indexed in ascending order.
129  *
130  * @group is defining the position of a page in a given pair. It can also be
131  * seen as the bit position in the cell: page attached to bit 0 belongs to
132  * group 0, page attached to bit 1 belongs to group 1, etc.
133  *
134  * Example:
135  * The H27UCG8T2BTR-BC datasheet describes the following pairing scheme:
136  *
137  *		group-0		group-1
138  *
139  *  pair-0	page-0		page-4
140  *  pair-1	page-1		page-5
141  *  pair-2	page-2		page-8
142  *  ...
143  *  pair-127	page-251	page-255
144  *
145  *
146  * Note that the "group" and "pair" terms were extracted from Samsung and
147  * Hynix datasheets, and might be referenced under other names in other
148  * datasheets (Micron is describing this concept as "shared pages").
149  */
150 struct mtd_pairing_info {
151 	int pair;
152 	int group;
153 };
154 
155 /**
156  * struct mtd_pairing_scheme - page pairing scheme description
157  *
158  * @ngroups: number of groups. Should be related to the number of bits
159  *	     per cell.
160  * @get_info: converts a write-unit (page number within an erase block) into
161  *	      mtd_pairing information (pair + group). This function should
162  *	      fill the info parameter based on the wunit index or return
163  *	      -EINVAL if the wunit parameter is invalid.
164  * @get_wunit: converts pairing information into a write-unit (page) number.
165  *	       This function should return the wunit index pointed by the
166  *	       pairing information described in the info argument. It should
167  *	       return -EINVAL, if there's no wunit corresponding to the
168  *	       passed pairing information.
169  *
170  * See mtd_pairing_info documentation for a detailed explanation of the
171  * pair and group concepts.
172  *
173  * The mtd_pairing_scheme structure provides a generic solution to represent
174  * NAND page pairing scheme. Instead of exposing two big tables to do the
175  * write-unit <-> (pair + group) conversions, we ask the MTD drivers to
176  * implement the ->get_info() and ->get_wunit() functions.
177  *
178  * MTD users will then be able to query these information by using the
179  * mtd_pairing_info_to_wunit() and mtd_wunit_to_pairing_info() helpers.
180  *
181  * @ngroups is here to help MTD users iterating over all the pages in a
182  * given pair. This value can be retrieved by MTD users using the
183  * mtd_pairing_groups() helper.
184  *
185  * Examples are given in the mtd_pairing_info_to_wunit() and
186  * mtd_wunit_to_pairing_info() documentation.
187  */
188 struct mtd_pairing_scheme {
189 	int ngroups;
190 	int (*get_info)(struct mtd_info *mtd, int wunit,
191 			struct mtd_pairing_info *info);
192 	int (*get_wunit)(struct mtd_info *mtd,
193 			 const struct mtd_pairing_info *info);
194 };
195 
196 struct module;	/* only needed for owner field in mtd_info */
197 
198 /**
199  * struct mtd_debug_info - debugging information for an MTD device.
200  *
201  * @dfs_dir: direntry object of the MTD device debugfs directory
202  */
203 struct mtd_debug_info {
204 	struct dentry *dfs_dir;
205 };
206 
207 struct mtd_info {
208 	u_char type;
209 	uint32_t flags;
210 	uint32_t orig_flags; /* Flags as before running mtd checks */
211 	uint64_t size;	 // Total size of the MTD
212 
213 	/* "Major" erase size for the device. Naïve users may take this
214 	 * to be the only erase size available, or may use the more detailed
215 	 * information below if they desire
216 	 */
217 	uint32_t erasesize;
218 	/* Minimal writable flash unit size. In case of NOR flash it is 1 (even
219 	 * though individual bits can be cleared), in case of NAND flash it is
220 	 * one NAND page (or half, or one-fourths of it), in case of ECC-ed NOR
221 	 * it is of ECC block size, etc. It is illegal to have writesize = 0.
222 	 * Any driver registering a struct mtd_info must ensure a writesize of
223 	 * 1 or larger.
224 	 */
225 	uint32_t writesize;
226 
227 	/*
228 	 * Size of the write buffer used by the MTD. MTD devices having a write
229 	 * buffer can write multiple writesize chunks at a time. E.g. while
230 	 * writing 4 * writesize bytes to a device with 2 * writesize bytes
231 	 * buffer the MTD driver can (but doesn't have to) do 2 writesize
232 	 * operations, but not 4. Currently, all NANDs have writebufsize
233 	 * equivalent to writesize (NAND page size). Some NOR flashes do have
234 	 * writebufsize greater than writesize.
235 	 */
236 	uint32_t writebufsize;
237 
238 	uint32_t oobsize;   // Amount of OOB data per block (e.g. 16)
239 	uint32_t oobavail;  // Available OOB bytes per block
240 
241 	/*
242 	 * If erasesize is a power of 2 then the shift is stored in
243 	 * erasesize_shift otherwise erasesize_shift is zero. Ditto writesize.
244 	 */
245 	unsigned int erasesize_shift;
246 	unsigned int writesize_shift;
247 	/* Masks based on erasesize_shift and writesize_shift */
248 	unsigned int erasesize_mask;
249 	unsigned int writesize_mask;
250 
251 	/*
252 	 * read ops return -EUCLEAN if max number of bitflips corrected on any
253 	 * one region comprising an ecc step equals or exceeds this value.
254 	 * Settable by driver, else defaults to ecc_strength.  User can override
255 	 * in sysfs.  N.B. The meaning of the -EUCLEAN return code has changed;
256 	 * see Documentation/ABI/testing/sysfs-class-mtd for more detail.
257 	 */
258 	unsigned int bitflip_threshold;
259 
260 	/* Kernel-only stuff starts here. */
261 	const char *name;
262 	int index;
263 
264 	/* OOB layout description */
265 	const struct mtd_ooblayout_ops *ooblayout;
266 
267 	/* NAND pairing scheme, only provided for MLC/TLC NANDs */
268 	const struct mtd_pairing_scheme *pairing;
269 
270 	/* the ecc step size. */
271 	unsigned int ecc_step_size;
272 
273 	/* max number of correctible bit errors per ecc step */
274 	unsigned int ecc_strength;
275 
276 	/* Data for variable erase regions. If numeraseregions is zero,
277 	 * it means that the whole device has erasesize as given above.
278 	 */
279 	int numeraseregions;
280 	struct mtd_erase_region_info *eraseregions;
281 
282 	/*
283 	 * Do not call via these pointers, use corresponding mtd_*()
284 	 * wrappers instead.
285 	 */
286 	int (*_erase) (struct mtd_info *mtd, struct erase_info *instr);
287 	int (*_point) (struct mtd_info *mtd, loff_t from, size_t len,
288 		       size_t *retlen, void **virt, resource_size_t *phys);
289 	int (*_unpoint) (struct mtd_info *mtd, loff_t from, size_t len);
290 	int (*_read) (struct mtd_info *mtd, loff_t from, size_t len,
291 		      size_t *retlen, u_char *buf);
292 	int (*_write) (struct mtd_info *mtd, loff_t to, size_t len,
293 		       size_t *retlen, const u_char *buf);
294 	int (*_panic_write) (struct mtd_info *mtd, loff_t to, size_t len,
295 			     size_t *retlen, const u_char *buf);
296 	int (*_read_oob) (struct mtd_info *mtd, loff_t from,
297 			  struct mtd_oob_ops *ops);
298 	int (*_write_oob) (struct mtd_info *mtd, loff_t to,
299 			   struct mtd_oob_ops *ops);
300 	int (*_get_fact_prot_info) (struct mtd_info *mtd, size_t len,
301 				    size_t *retlen, struct otp_info *buf);
302 	int (*_read_fact_prot_reg) (struct mtd_info *mtd, loff_t from,
303 				    size_t len, size_t *retlen, u_char *buf);
304 	int (*_get_user_prot_info) (struct mtd_info *mtd, size_t len,
305 				    size_t *retlen, struct otp_info *buf);
306 	int (*_read_user_prot_reg) (struct mtd_info *mtd, loff_t from,
307 				    size_t len, size_t *retlen, u_char *buf);
308 	int (*_write_user_prot_reg) (struct mtd_info *mtd, loff_t to,
309 				     size_t len, size_t *retlen, u_char *buf);
310 	int (*_lock_user_prot_reg) (struct mtd_info *mtd, loff_t from,
311 				    size_t len);
312 	int (*_writev) (struct mtd_info *mtd, const struct kvec *vecs,
313 			unsigned long count, loff_t to, size_t *retlen);
314 	void (*_sync) (struct mtd_info *mtd);
315 	int (*_lock) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
316 	int (*_unlock) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
317 	int (*_is_locked) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
318 	int (*_block_isreserved) (struct mtd_info *mtd, loff_t ofs);
319 	int (*_block_isbad) (struct mtd_info *mtd, loff_t ofs);
320 	int (*_block_markbad) (struct mtd_info *mtd, loff_t ofs);
321 	int (*_max_bad_blocks) (struct mtd_info *mtd, loff_t ofs, size_t len);
322 	int (*_suspend) (struct mtd_info *mtd);
323 	void (*_resume) (struct mtd_info *mtd);
324 	void (*_reboot) (struct mtd_info *mtd);
325 	/*
326 	 * If the driver is something smart, like UBI, it may need to maintain
327 	 * its own reference counting. The below functions are only for driver.
328 	 */
329 	int (*_get_device) (struct mtd_info *mtd);
330 	void (*_put_device) (struct mtd_info *mtd);
331 
332 	struct notifier_block reboot_notifier;  /* default mode before reboot */
333 
334 	/* ECC status information */
335 	struct mtd_ecc_stats ecc_stats;
336 	/* Subpage shift (NAND) */
337 	int subpage_sft;
338 
339 	void *priv;
340 
341 	struct module *owner;
342 	struct device dev;
343 	int usecount;
344 	struct mtd_debug_info dbg;
345 };
346 
347 int mtd_ooblayout_ecc(struct mtd_info *mtd, int section,
348 		      struct mtd_oob_region *oobecc);
349 int mtd_ooblayout_find_eccregion(struct mtd_info *mtd, int eccbyte,
350 				 int *section,
351 				 struct mtd_oob_region *oobregion);
352 int mtd_ooblayout_get_eccbytes(struct mtd_info *mtd, u8 *eccbuf,
353 			       const u8 *oobbuf, int start, int nbytes);
354 int mtd_ooblayout_set_eccbytes(struct mtd_info *mtd, const u8 *eccbuf,
355 			       u8 *oobbuf, int start, int nbytes);
356 int mtd_ooblayout_free(struct mtd_info *mtd, int section,
357 		       struct mtd_oob_region *oobfree);
358 int mtd_ooblayout_get_databytes(struct mtd_info *mtd, u8 *databuf,
359 				const u8 *oobbuf, int start, int nbytes);
360 int mtd_ooblayout_set_databytes(struct mtd_info *mtd, const u8 *databuf,
361 				u8 *oobbuf, int start, int nbytes);
362 int mtd_ooblayout_count_freebytes(struct mtd_info *mtd);
363 int mtd_ooblayout_count_eccbytes(struct mtd_info *mtd);
364 
365 static inline void mtd_set_ooblayout(struct mtd_info *mtd,
366 				     const struct mtd_ooblayout_ops *ooblayout)
367 {
368 	mtd->ooblayout = ooblayout;
369 }
370 
371 static inline void mtd_set_pairing_scheme(struct mtd_info *mtd,
372 				const struct mtd_pairing_scheme *pairing)
373 {
374 	mtd->pairing = pairing;
375 }
376 
377 static inline void mtd_set_of_node(struct mtd_info *mtd,
378 				   struct device_node *np)
379 {
380 	mtd->dev.of_node = np;
381 	if (!mtd->name)
382 		of_property_read_string(np, "label", &mtd->name);
383 }
384 
385 static inline struct device_node *mtd_get_of_node(struct mtd_info *mtd)
386 {
387 	return dev_of_node(&mtd->dev);
388 }
389 
390 static inline u32 mtd_oobavail(struct mtd_info *mtd, struct mtd_oob_ops *ops)
391 {
392 	return ops->mode == MTD_OPS_AUTO_OOB ? mtd->oobavail : mtd->oobsize;
393 }
394 
395 static inline int mtd_max_bad_blocks(struct mtd_info *mtd,
396 				     loff_t ofs, size_t len)
397 {
398 	if (!mtd->_max_bad_blocks)
399 		return -ENOTSUPP;
400 
401 	if (mtd->size < (len + ofs) || ofs < 0)
402 		return -EINVAL;
403 
404 	return mtd->_max_bad_blocks(mtd, ofs, len);
405 }
406 
407 int mtd_wunit_to_pairing_info(struct mtd_info *mtd, int wunit,
408 			      struct mtd_pairing_info *info);
409 int mtd_pairing_info_to_wunit(struct mtd_info *mtd,
410 			      const struct mtd_pairing_info *info);
411 int mtd_pairing_groups(struct mtd_info *mtd);
412 int mtd_erase(struct mtd_info *mtd, struct erase_info *instr);
413 int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
414 	      void **virt, resource_size_t *phys);
415 int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len);
416 unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
417 				    unsigned long offset, unsigned long flags);
418 int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
419 	     u_char *buf);
420 int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
421 	      const u_char *buf);
422 int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
423 		    const u_char *buf);
424 
425 int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops);
426 int mtd_write_oob(struct mtd_info *mtd, loff_t to, struct mtd_oob_ops *ops);
427 
428 int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
429 			   struct otp_info *buf);
430 int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
431 			   size_t *retlen, u_char *buf);
432 int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
433 			   struct otp_info *buf);
434 int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
435 			   size_t *retlen, u_char *buf);
436 int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
437 			    size_t *retlen, u_char *buf);
438 int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len);
439 
440 int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
441 	       unsigned long count, loff_t to, size_t *retlen);
442 
443 static inline void mtd_sync(struct mtd_info *mtd)
444 {
445 	if (mtd->_sync)
446 		mtd->_sync(mtd);
447 }
448 
449 int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
450 int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
451 int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len);
452 int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs);
453 int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs);
454 int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs);
455 
456 static inline int mtd_suspend(struct mtd_info *mtd)
457 {
458 	return mtd->_suspend ? mtd->_suspend(mtd) : 0;
459 }
460 
461 static inline void mtd_resume(struct mtd_info *mtd)
462 {
463 	if (mtd->_resume)
464 		mtd->_resume(mtd);
465 }
466 
467 static inline uint32_t mtd_div_by_eb(uint64_t sz, struct mtd_info *mtd)
468 {
469 	if (mtd->erasesize_shift)
470 		return sz >> mtd->erasesize_shift;
471 	do_div(sz, mtd->erasesize);
472 	return sz;
473 }
474 
475 static inline uint32_t mtd_mod_by_eb(uint64_t sz, struct mtd_info *mtd)
476 {
477 	if (mtd->erasesize_shift)
478 		return sz & mtd->erasesize_mask;
479 	return do_div(sz, mtd->erasesize);
480 }
481 
482 /**
483  * mtd_align_erase_req - Adjust an erase request to align things on eraseblock
484  *			 boundaries.
485  * @mtd: the MTD device this erase request applies on
486  * @req: the erase request to adjust
487  *
488  * This function will adjust @req->addr and @req->len to align them on
489  * @mtd->erasesize. Of course we expect @mtd->erasesize to be != 0.
490  */
491 static inline void mtd_align_erase_req(struct mtd_info *mtd,
492 				       struct erase_info *req)
493 {
494 	u32 mod;
495 
496 	if (WARN_ON(!mtd->erasesize))
497 		return;
498 
499 	mod = mtd_mod_by_eb(req->addr, mtd);
500 	if (mod) {
501 		req->addr -= mod;
502 		req->len += mod;
503 	}
504 
505 	mod = mtd_mod_by_eb(req->addr + req->len, mtd);
506 	if (mod)
507 		req->len += mtd->erasesize - mod;
508 }
509 
510 static inline uint32_t mtd_div_by_ws(uint64_t sz, struct mtd_info *mtd)
511 {
512 	if (mtd->writesize_shift)
513 		return sz >> mtd->writesize_shift;
514 	do_div(sz, mtd->writesize);
515 	return sz;
516 }
517 
518 static inline uint32_t mtd_mod_by_ws(uint64_t sz, struct mtd_info *mtd)
519 {
520 	if (mtd->writesize_shift)
521 		return sz & mtd->writesize_mask;
522 	return do_div(sz, mtd->writesize);
523 }
524 
525 static inline int mtd_wunit_per_eb(struct mtd_info *mtd)
526 {
527 	return mtd->erasesize / mtd->writesize;
528 }
529 
530 static inline int mtd_offset_to_wunit(struct mtd_info *mtd, loff_t offs)
531 {
532 	return mtd_div_by_ws(mtd_mod_by_eb(offs, mtd), mtd);
533 }
534 
535 static inline loff_t mtd_wunit_to_offset(struct mtd_info *mtd, loff_t base,
536 					 int wunit)
537 {
538 	return base + (wunit * mtd->writesize);
539 }
540 
541 
542 static inline int mtd_has_oob(const struct mtd_info *mtd)
543 {
544 	return mtd->_read_oob && mtd->_write_oob;
545 }
546 
547 static inline int mtd_type_is_nand(const struct mtd_info *mtd)
548 {
549 	return mtd->type == MTD_NANDFLASH || mtd->type == MTD_MLCNANDFLASH;
550 }
551 
552 static inline int mtd_can_have_bb(const struct mtd_info *mtd)
553 {
554 	return !!mtd->_block_isbad;
555 }
556 
557 	/* Kernel-side ioctl definitions */
558 
559 struct mtd_partition;
560 struct mtd_part_parser_data;
561 
562 extern int mtd_device_parse_register(struct mtd_info *mtd,
563 				     const char * const *part_probe_types,
564 				     struct mtd_part_parser_data *parser_data,
565 				     const struct mtd_partition *defparts,
566 				     int defnr_parts);
567 #define mtd_device_register(master, parts, nr_parts)	\
568 	mtd_device_parse_register(master, NULL, NULL, parts, nr_parts)
569 extern int mtd_device_unregister(struct mtd_info *master);
570 extern struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num);
571 extern int __get_mtd_device(struct mtd_info *mtd);
572 extern void __put_mtd_device(struct mtd_info *mtd);
573 extern struct mtd_info *get_mtd_device_nm(const char *name);
574 extern void put_mtd_device(struct mtd_info *mtd);
575 
576 
577 struct mtd_notifier {
578 	void (*add)(struct mtd_info *mtd);
579 	void (*remove)(struct mtd_info *mtd);
580 	struct list_head list;
581 };
582 
583 
584 extern void register_mtd_user (struct mtd_notifier *new);
585 extern int unregister_mtd_user (struct mtd_notifier *old);
586 void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size);
587 
588 static inline int mtd_is_bitflip(int err) {
589 	return err == -EUCLEAN;
590 }
591 
592 static inline int mtd_is_eccerr(int err) {
593 	return err == -EBADMSG;
594 }
595 
596 static inline int mtd_is_bitflip_or_eccerr(int err) {
597 	return mtd_is_bitflip(err) || mtd_is_eccerr(err);
598 }
599 
600 unsigned mtd_mmap_capabilities(struct mtd_info *mtd);
601 
602 #endif /* __MTD_MTD_H__ */
603