xref: /openbmc/linux/include/linux/mtd/mtd.h (revision b830f94f)
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/notifier.h>
12 #include <linux/device.h>
13 #include <linux/of.h>
14 #include <linux/nvmem-provider.h>
15 
16 #include <mtd/mtd-abi.h>
17 
18 #include <asm/div64.h>
19 
20 #define MTD_FAIL_ADDR_UNKNOWN -1LL
21 
22 struct mtd_info;
23 
24 /*
25  * If the erase fails, fail_addr might indicate exactly which block failed. If
26  * fail_addr = MTD_FAIL_ADDR_UNKNOWN, the failure was not at the device level
27  * or was not specific to any particular block.
28  */
29 struct erase_info {
30 	uint64_t addr;
31 	uint64_t len;
32 	uint64_t fail_addr;
33 };
34 
35 struct mtd_erase_region_info {
36 	uint64_t offset;		/* At which this region starts, from the beginning of the MTD */
37 	uint32_t erasesize;		/* For this region */
38 	uint32_t numblocks;		/* Number of blocks of erasesize in this region */
39 	unsigned long *lockmap;		/* If keeping bitmap of locks */
40 };
41 
42 /**
43  * struct mtd_oob_ops - oob operation operands
44  * @mode:	operation mode
45  *
46  * @len:	number of data bytes to write/read
47  *
48  * @retlen:	number of data bytes written/read
49  *
50  * @ooblen:	number of oob bytes to write/read
51  * @oobretlen:	number of oob bytes written/read
52  * @ooboffs:	offset of oob data in the oob area (only relevant when
53  *		mode = MTD_OPS_PLACE_OOB or MTD_OPS_RAW)
54  * @datbuf:	data buffer - if NULL only oob data are read/written
55  * @oobbuf:	oob data buffer
56  *
57  * Note, some MTD drivers do not allow you to write more than one OOB area at
58  * one go. If you try to do that on such an MTD device, -EINVAL will be
59  * returned. If you want to make your implementation portable on all kind of MTD
60  * devices you should split the write request into several sub-requests when the
61  * request crosses a page boundary.
62  */
63 struct mtd_oob_ops {
64 	unsigned int	mode;
65 	size_t		len;
66 	size_t		retlen;
67 	size_t		ooblen;
68 	size_t		oobretlen;
69 	uint32_t	ooboffs;
70 	uint8_t		*datbuf;
71 	uint8_t		*oobbuf;
72 };
73 
74 #define MTD_MAX_OOBFREE_ENTRIES_LARGE	32
75 #define MTD_MAX_ECCPOS_ENTRIES_LARGE	640
76 /**
77  * struct mtd_oob_region - oob region definition
78  * @offset: region offset
79  * @length: region length
80  *
81  * This structure describes a region of the OOB area, and is used
82  * to retrieve ECC or free bytes sections.
83  * Each section is defined by an offset within the OOB area and a
84  * length.
85  */
86 struct mtd_oob_region {
87 	u32 offset;
88 	u32 length;
89 };
90 
91 /*
92  * struct mtd_ooblayout_ops - NAND OOB layout operations
93  * @ecc: function returning an ECC region in the OOB area.
94  *	 Should return -ERANGE if %section exceeds the total number of
95  *	 ECC sections.
96  * @free: function returning a free region in the OOB area.
97  *	  Should return -ERANGE if %section exceeds the total number of
98  *	  free sections.
99  */
100 struct mtd_ooblayout_ops {
101 	int (*ecc)(struct mtd_info *mtd, int section,
102 		   struct mtd_oob_region *oobecc);
103 	int (*free)(struct mtd_info *mtd, int section,
104 		    struct mtd_oob_region *oobfree);
105 };
106 
107 /**
108  * struct mtd_pairing_info - page pairing information
109  *
110  * @pair: pair id
111  * @group: group id
112  *
113  * The term "pair" is used here, even though TLC NANDs might group pages by 3
114  * (3 bits in a single cell). A pair should regroup all pages that are sharing
115  * the same cell. Pairs are then indexed in ascending order.
116  *
117  * @group is defining the position of a page in a given pair. It can also be
118  * seen as the bit position in the cell: page attached to bit 0 belongs to
119  * group 0, page attached to bit 1 belongs to group 1, etc.
120  *
121  * Example:
122  * The H27UCG8T2BTR-BC datasheet describes the following pairing scheme:
123  *
124  *		group-0		group-1
125  *
126  *  pair-0	page-0		page-4
127  *  pair-1	page-1		page-5
128  *  pair-2	page-2		page-8
129  *  ...
130  *  pair-127	page-251	page-255
131  *
132  *
133  * Note that the "group" and "pair" terms were extracted from Samsung and
134  * Hynix datasheets, and might be referenced under other names in other
135  * datasheets (Micron is describing this concept as "shared pages").
136  */
137 struct mtd_pairing_info {
138 	int pair;
139 	int group;
140 };
141 
142 /**
143  * struct mtd_pairing_scheme - page pairing scheme description
144  *
145  * @ngroups: number of groups. Should be related to the number of bits
146  *	     per cell.
147  * @get_info: converts a write-unit (page number within an erase block) into
148  *	      mtd_pairing information (pair + group). This function should
149  *	      fill the info parameter based on the wunit index or return
150  *	      -EINVAL if the wunit parameter is invalid.
151  * @get_wunit: converts pairing information into a write-unit (page) number.
152  *	       This function should return the wunit index pointed by the
153  *	       pairing information described in the info argument. It should
154  *	       return -EINVAL, if there's no wunit corresponding to the
155  *	       passed pairing information.
156  *
157  * See mtd_pairing_info documentation for a detailed explanation of the
158  * pair and group concepts.
159  *
160  * The mtd_pairing_scheme structure provides a generic solution to represent
161  * NAND page pairing scheme. Instead of exposing two big tables to do the
162  * write-unit <-> (pair + group) conversions, we ask the MTD drivers to
163  * implement the ->get_info() and ->get_wunit() functions.
164  *
165  * MTD users will then be able to query these information by using the
166  * mtd_pairing_info_to_wunit() and mtd_wunit_to_pairing_info() helpers.
167  *
168  * @ngroups is here to help MTD users iterating over all the pages in a
169  * given pair. This value can be retrieved by MTD users using the
170  * mtd_pairing_groups() helper.
171  *
172  * Examples are given in the mtd_pairing_info_to_wunit() and
173  * mtd_wunit_to_pairing_info() documentation.
174  */
175 struct mtd_pairing_scheme {
176 	int ngroups;
177 	int (*get_info)(struct mtd_info *mtd, int wunit,
178 			struct mtd_pairing_info *info);
179 	int (*get_wunit)(struct mtd_info *mtd,
180 			 const struct mtd_pairing_info *info);
181 };
182 
183 struct module;	/* only needed for owner field in mtd_info */
184 
185 /**
186  * struct mtd_debug_info - debugging information for an MTD device.
187  *
188  * @dfs_dir: direntry object of the MTD device debugfs directory
189  */
190 struct mtd_debug_info {
191 	struct dentry *dfs_dir;
192 };
193 
194 struct mtd_info {
195 	u_char type;
196 	uint32_t flags;
197 	uint32_t orig_flags; /* Flags as before running mtd checks */
198 	uint64_t size;	 // Total size of the MTD
199 
200 	/* "Major" erase size for the device. Naïve users may take this
201 	 * to be the only erase size available, or may use the more detailed
202 	 * information below if they desire
203 	 */
204 	uint32_t erasesize;
205 	/* Minimal writable flash unit size. In case of NOR flash it is 1 (even
206 	 * though individual bits can be cleared), in case of NAND flash it is
207 	 * one NAND page (or half, or one-fourths of it), in case of ECC-ed NOR
208 	 * it is of ECC block size, etc. It is illegal to have writesize = 0.
209 	 * Any driver registering a struct mtd_info must ensure a writesize of
210 	 * 1 or larger.
211 	 */
212 	uint32_t writesize;
213 
214 	/*
215 	 * Size of the write buffer used by the MTD. MTD devices having a write
216 	 * buffer can write multiple writesize chunks at a time. E.g. while
217 	 * writing 4 * writesize bytes to a device with 2 * writesize bytes
218 	 * buffer the MTD driver can (but doesn't have to) do 2 writesize
219 	 * operations, but not 4. Currently, all NANDs have writebufsize
220 	 * equivalent to writesize (NAND page size). Some NOR flashes do have
221 	 * writebufsize greater than writesize.
222 	 */
223 	uint32_t writebufsize;
224 
225 	uint32_t oobsize;   // Amount of OOB data per block (e.g. 16)
226 	uint32_t oobavail;  // Available OOB bytes per block
227 
228 	/*
229 	 * If erasesize is a power of 2 then the shift is stored in
230 	 * erasesize_shift otherwise erasesize_shift is zero. Ditto writesize.
231 	 */
232 	unsigned int erasesize_shift;
233 	unsigned int writesize_shift;
234 	/* Masks based on erasesize_shift and writesize_shift */
235 	unsigned int erasesize_mask;
236 	unsigned int writesize_mask;
237 
238 	/*
239 	 * read ops return -EUCLEAN if max number of bitflips corrected on any
240 	 * one region comprising an ecc step equals or exceeds this value.
241 	 * Settable by driver, else defaults to ecc_strength.  User can override
242 	 * in sysfs.  N.B. The meaning of the -EUCLEAN return code has changed;
243 	 * see Documentation/ABI/testing/sysfs-class-mtd for more detail.
244 	 */
245 	unsigned int bitflip_threshold;
246 
247 	/* Kernel-only stuff starts here. */
248 	const char *name;
249 	int index;
250 
251 	/* OOB layout description */
252 	const struct mtd_ooblayout_ops *ooblayout;
253 
254 	/* NAND pairing scheme, only provided for MLC/TLC NANDs */
255 	const struct mtd_pairing_scheme *pairing;
256 
257 	/* the ecc step size. */
258 	unsigned int ecc_step_size;
259 
260 	/* max number of correctible bit errors per ecc step */
261 	unsigned int ecc_strength;
262 
263 	/* Data for variable erase regions. If numeraseregions is zero,
264 	 * it means that the whole device has erasesize as given above.
265 	 */
266 	int numeraseregions;
267 	struct mtd_erase_region_info *eraseregions;
268 
269 	/*
270 	 * Do not call via these pointers, use corresponding mtd_*()
271 	 * wrappers instead.
272 	 */
273 	int (*_erase) (struct mtd_info *mtd, struct erase_info *instr);
274 	int (*_point) (struct mtd_info *mtd, loff_t from, size_t len,
275 		       size_t *retlen, void **virt, resource_size_t *phys);
276 	int (*_unpoint) (struct mtd_info *mtd, loff_t from, size_t len);
277 	int (*_read) (struct mtd_info *mtd, loff_t from, size_t len,
278 		      size_t *retlen, u_char *buf);
279 	int (*_write) (struct mtd_info *mtd, loff_t to, size_t len,
280 		       size_t *retlen, const u_char *buf);
281 	int (*_panic_write) (struct mtd_info *mtd, loff_t to, size_t len,
282 			     size_t *retlen, const u_char *buf);
283 	int (*_read_oob) (struct mtd_info *mtd, loff_t from,
284 			  struct mtd_oob_ops *ops);
285 	int (*_write_oob) (struct mtd_info *mtd, loff_t to,
286 			   struct mtd_oob_ops *ops);
287 	int (*_get_fact_prot_info) (struct mtd_info *mtd, size_t len,
288 				    size_t *retlen, struct otp_info *buf);
289 	int (*_read_fact_prot_reg) (struct mtd_info *mtd, loff_t from,
290 				    size_t len, size_t *retlen, u_char *buf);
291 	int (*_get_user_prot_info) (struct mtd_info *mtd, size_t len,
292 				    size_t *retlen, struct otp_info *buf);
293 	int (*_read_user_prot_reg) (struct mtd_info *mtd, loff_t from,
294 				    size_t len, size_t *retlen, u_char *buf);
295 	int (*_write_user_prot_reg) (struct mtd_info *mtd, loff_t to,
296 				     size_t len, size_t *retlen, u_char *buf);
297 	int (*_lock_user_prot_reg) (struct mtd_info *mtd, loff_t from,
298 				    size_t len);
299 	int (*_writev) (struct mtd_info *mtd, const struct kvec *vecs,
300 			unsigned long count, loff_t to, size_t *retlen);
301 	void (*_sync) (struct mtd_info *mtd);
302 	int (*_lock) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
303 	int (*_unlock) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
304 	int (*_is_locked) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
305 	int (*_block_isreserved) (struct mtd_info *mtd, loff_t ofs);
306 	int (*_block_isbad) (struct mtd_info *mtd, loff_t ofs);
307 	int (*_block_markbad) (struct mtd_info *mtd, loff_t ofs);
308 	int (*_max_bad_blocks) (struct mtd_info *mtd, loff_t ofs, size_t len);
309 	int (*_suspend) (struct mtd_info *mtd);
310 	void (*_resume) (struct mtd_info *mtd);
311 	void (*_reboot) (struct mtd_info *mtd);
312 	/*
313 	 * If the driver is something smart, like UBI, it may need to maintain
314 	 * its own reference counting. The below functions are only for driver.
315 	 */
316 	int (*_get_device) (struct mtd_info *mtd);
317 	void (*_put_device) (struct mtd_info *mtd);
318 
319 	/*
320 	 * flag indicates a panic write, low level drivers can take appropriate
321 	 * action if required to ensure writes go through
322 	 */
323 	bool oops_panic_write;
324 
325 	struct notifier_block reboot_notifier;  /* default mode before reboot */
326 
327 	/* ECC status information */
328 	struct mtd_ecc_stats ecc_stats;
329 	/* Subpage shift (NAND) */
330 	int subpage_sft;
331 
332 	void *priv;
333 
334 	struct module *owner;
335 	struct device dev;
336 	int usecount;
337 	struct mtd_debug_info dbg;
338 	struct nvmem_device *nvmem;
339 };
340 
341 int mtd_ooblayout_ecc(struct mtd_info *mtd, int section,
342 		      struct mtd_oob_region *oobecc);
343 int mtd_ooblayout_find_eccregion(struct mtd_info *mtd, int eccbyte,
344 				 int *section,
345 				 struct mtd_oob_region *oobregion);
346 int mtd_ooblayout_get_eccbytes(struct mtd_info *mtd, u8 *eccbuf,
347 			       const u8 *oobbuf, int start, int nbytes);
348 int mtd_ooblayout_set_eccbytes(struct mtd_info *mtd, const u8 *eccbuf,
349 			       u8 *oobbuf, int start, int nbytes);
350 int mtd_ooblayout_free(struct mtd_info *mtd, int section,
351 		       struct mtd_oob_region *oobfree);
352 int mtd_ooblayout_get_databytes(struct mtd_info *mtd, u8 *databuf,
353 				const u8 *oobbuf, int start, int nbytes);
354 int mtd_ooblayout_set_databytes(struct mtd_info *mtd, const u8 *databuf,
355 				u8 *oobbuf, int start, int nbytes);
356 int mtd_ooblayout_count_freebytes(struct mtd_info *mtd);
357 int mtd_ooblayout_count_eccbytes(struct mtd_info *mtd);
358 
359 static inline void mtd_set_ooblayout(struct mtd_info *mtd,
360 				     const struct mtd_ooblayout_ops *ooblayout)
361 {
362 	mtd->ooblayout = ooblayout;
363 }
364 
365 static inline void mtd_set_pairing_scheme(struct mtd_info *mtd,
366 				const struct mtd_pairing_scheme *pairing)
367 {
368 	mtd->pairing = pairing;
369 }
370 
371 static inline void mtd_set_of_node(struct mtd_info *mtd,
372 				   struct device_node *np)
373 {
374 	mtd->dev.of_node = np;
375 	if (!mtd->name)
376 		of_property_read_string(np, "label", &mtd->name);
377 }
378 
379 static inline struct device_node *mtd_get_of_node(struct mtd_info *mtd)
380 {
381 	return dev_of_node(&mtd->dev);
382 }
383 
384 static inline u32 mtd_oobavail(struct mtd_info *mtd, struct mtd_oob_ops *ops)
385 {
386 	return ops->mode == MTD_OPS_AUTO_OOB ? mtd->oobavail : mtd->oobsize;
387 }
388 
389 static inline int mtd_max_bad_blocks(struct mtd_info *mtd,
390 				     loff_t ofs, size_t len)
391 {
392 	if (!mtd->_max_bad_blocks)
393 		return -ENOTSUPP;
394 
395 	if (mtd->size < (len + ofs) || ofs < 0)
396 		return -EINVAL;
397 
398 	return mtd->_max_bad_blocks(mtd, ofs, len);
399 }
400 
401 int mtd_wunit_to_pairing_info(struct mtd_info *mtd, int wunit,
402 			      struct mtd_pairing_info *info);
403 int mtd_pairing_info_to_wunit(struct mtd_info *mtd,
404 			      const struct mtd_pairing_info *info);
405 int mtd_pairing_groups(struct mtd_info *mtd);
406 int mtd_erase(struct mtd_info *mtd, struct erase_info *instr);
407 int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
408 	      void **virt, resource_size_t *phys);
409 int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len);
410 unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
411 				    unsigned long offset, unsigned long flags);
412 int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
413 	     u_char *buf);
414 int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
415 	      const u_char *buf);
416 int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
417 		    const u_char *buf);
418 
419 int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops);
420 int mtd_write_oob(struct mtd_info *mtd, loff_t to, struct mtd_oob_ops *ops);
421 
422 int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
423 			   struct otp_info *buf);
424 int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
425 			   size_t *retlen, u_char *buf);
426 int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
427 			   struct otp_info *buf);
428 int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
429 			   size_t *retlen, u_char *buf);
430 int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
431 			    size_t *retlen, u_char *buf);
432 int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len);
433 
434 int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
435 	       unsigned long count, loff_t to, size_t *retlen);
436 
437 static inline void mtd_sync(struct mtd_info *mtd)
438 {
439 	if (mtd->_sync)
440 		mtd->_sync(mtd);
441 }
442 
443 int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
444 int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
445 int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len);
446 int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs);
447 int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs);
448 int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs);
449 
450 static inline int mtd_suspend(struct mtd_info *mtd)
451 {
452 	return mtd->_suspend ? mtd->_suspend(mtd) : 0;
453 }
454 
455 static inline void mtd_resume(struct mtd_info *mtd)
456 {
457 	if (mtd->_resume)
458 		mtd->_resume(mtd);
459 }
460 
461 static inline uint32_t mtd_div_by_eb(uint64_t sz, struct mtd_info *mtd)
462 {
463 	if (mtd->erasesize_shift)
464 		return sz >> mtd->erasesize_shift;
465 	do_div(sz, mtd->erasesize);
466 	return sz;
467 }
468 
469 static inline uint32_t mtd_mod_by_eb(uint64_t sz, struct mtd_info *mtd)
470 {
471 	if (mtd->erasesize_shift)
472 		return sz & mtd->erasesize_mask;
473 	return do_div(sz, mtd->erasesize);
474 }
475 
476 /**
477  * mtd_align_erase_req - Adjust an erase request to align things on eraseblock
478  *			 boundaries.
479  * @mtd: the MTD device this erase request applies on
480  * @req: the erase request to adjust
481  *
482  * This function will adjust @req->addr and @req->len to align them on
483  * @mtd->erasesize. Of course we expect @mtd->erasesize to be != 0.
484  */
485 static inline void mtd_align_erase_req(struct mtd_info *mtd,
486 				       struct erase_info *req)
487 {
488 	u32 mod;
489 
490 	if (WARN_ON(!mtd->erasesize))
491 		return;
492 
493 	mod = mtd_mod_by_eb(req->addr, mtd);
494 	if (mod) {
495 		req->addr -= mod;
496 		req->len += mod;
497 	}
498 
499 	mod = mtd_mod_by_eb(req->addr + req->len, mtd);
500 	if (mod)
501 		req->len += mtd->erasesize - mod;
502 }
503 
504 static inline uint32_t mtd_div_by_ws(uint64_t sz, struct mtd_info *mtd)
505 {
506 	if (mtd->writesize_shift)
507 		return sz >> mtd->writesize_shift;
508 	do_div(sz, mtd->writesize);
509 	return sz;
510 }
511 
512 static inline uint32_t mtd_mod_by_ws(uint64_t sz, struct mtd_info *mtd)
513 {
514 	if (mtd->writesize_shift)
515 		return sz & mtd->writesize_mask;
516 	return do_div(sz, mtd->writesize);
517 }
518 
519 static inline int mtd_wunit_per_eb(struct mtd_info *mtd)
520 {
521 	return mtd->erasesize / mtd->writesize;
522 }
523 
524 static inline int mtd_offset_to_wunit(struct mtd_info *mtd, loff_t offs)
525 {
526 	return mtd_div_by_ws(mtd_mod_by_eb(offs, mtd), mtd);
527 }
528 
529 static inline loff_t mtd_wunit_to_offset(struct mtd_info *mtd, loff_t base,
530 					 int wunit)
531 {
532 	return base + (wunit * mtd->writesize);
533 }
534 
535 
536 static inline int mtd_has_oob(const struct mtd_info *mtd)
537 {
538 	return mtd->_read_oob && mtd->_write_oob;
539 }
540 
541 static inline int mtd_type_is_nand(const struct mtd_info *mtd)
542 {
543 	return mtd->type == MTD_NANDFLASH || mtd->type == MTD_MLCNANDFLASH;
544 }
545 
546 static inline int mtd_can_have_bb(const struct mtd_info *mtd)
547 {
548 	return !!mtd->_block_isbad;
549 }
550 
551 	/* Kernel-side ioctl definitions */
552 
553 struct mtd_partition;
554 struct mtd_part_parser_data;
555 
556 extern int mtd_device_parse_register(struct mtd_info *mtd,
557 				     const char * const *part_probe_types,
558 				     struct mtd_part_parser_data *parser_data,
559 				     const struct mtd_partition *defparts,
560 				     int defnr_parts);
561 #define mtd_device_register(master, parts, nr_parts)	\
562 	mtd_device_parse_register(master, NULL, NULL, parts, nr_parts)
563 extern int mtd_device_unregister(struct mtd_info *master);
564 extern struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num);
565 extern int __get_mtd_device(struct mtd_info *mtd);
566 extern void __put_mtd_device(struct mtd_info *mtd);
567 extern struct mtd_info *get_mtd_device_nm(const char *name);
568 extern void put_mtd_device(struct mtd_info *mtd);
569 
570 
571 struct mtd_notifier {
572 	void (*add)(struct mtd_info *mtd);
573 	void (*remove)(struct mtd_info *mtd);
574 	struct list_head list;
575 };
576 
577 
578 extern void register_mtd_user (struct mtd_notifier *new);
579 extern int unregister_mtd_user (struct mtd_notifier *old);
580 void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size);
581 
582 static inline int mtd_is_bitflip(int err) {
583 	return err == -EUCLEAN;
584 }
585 
586 static inline int mtd_is_eccerr(int err) {
587 	return err == -EBADMSG;
588 }
589 
590 static inline int mtd_is_bitflip_or_eccerr(int err) {
591 	return mtd_is_bitflip(err) || mtd_is_eccerr(err);
592 }
593 
594 unsigned mtd_mmap_capabilities(struct mtd_info *mtd);
595 
596 #endif /* __MTD_MTD_H__ */
597