xref: /openbmc/linux/include/linux/mtd/mtd.h (revision 61f4d204)
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 struct mtd_req_stats {
44 	unsigned int uncorrectable_errors;
45 	unsigned int corrected_bitflips;
46 	unsigned int max_bitflips;
47 };
48 
49 /**
50  * struct mtd_oob_ops - oob operation operands
51  * @mode:	operation mode
52  *
53  * @len:	number of data bytes to write/read
54  *
55  * @retlen:	number of data bytes written/read
56  *
57  * @ooblen:	number of oob bytes to write/read
58  * @oobretlen:	number of oob bytes written/read
59  * @ooboffs:	offset of oob data in the oob area (only relevant when
60  *		mode = MTD_OPS_PLACE_OOB or MTD_OPS_RAW)
61  * @datbuf:	data buffer - if NULL only oob data are read/written
62  * @oobbuf:	oob data buffer
63  *
64  * Note, some MTD drivers do not allow you to write more than one OOB area at
65  * one go. If you try to do that on such an MTD device, -EINVAL will be
66  * returned. If you want to make your implementation portable on all kind of MTD
67  * devices you should split the write request into several sub-requests when the
68  * request crosses a page boundary.
69  */
70 struct mtd_oob_ops {
71 	unsigned int	mode;
72 	size_t		len;
73 	size_t		retlen;
74 	size_t		ooblen;
75 	size_t		oobretlen;
76 	uint32_t	ooboffs;
77 	uint8_t		*datbuf;
78 	uint8_t		*oobbuf;
79 	struct mtd_req_stats *stats;
80 };
81 
82 /**
83  * struct mtd_oob_region - oob region definition
84  * @offset: region offset
85  * @length: region length
86  *
87  * This structure describes a region of the OOB area, and is used
88  * to retrieve ECC or free bytes sections.
89  * Each section is defined by an offset within the OOB area and a
90  * length.
91  */
92 struct mtd_oob_region {
93 	u32 offset;
94 	u32 length;
95 };
96 
97 /*
98  * struct mtd_ooblayout_ops - NAND OOB layout operations
99  * @ecc: function returning an ECC region in the OOB area.
100  *	 Should return -ERANGE if %section exceeds the total number of
101  *	 ECC sections.
102  * @free: function returning a free region in the OOB area.
103  *	  Should return -ERANGE if %section exceeds the total number of
104  *	  free sections.
105  */
106 struct mtd_ooblayout_ops {
107 	int (*ecc)(struct mtd_info *mtd, int section,
108 		   struct mtd_oob_region *oobecc);
109 	int (*free)(struct mtd_info *mtd, int section,
110 		    struct mtd_oob_region *oobfree);
111 };
112 
113 /**
114  * struct mtd_pairing_info - page pairing information
115  *
116  * @pair: pair id
117  * @group: group id
118  *
119  * The term "pair" is used here, even though TLC NANDs might group pages by 3
120  * (3 bits in a single cell). A pair should regroup all pages that are sharing
121  * the same cell. Pairs are then indexed in ascending order.
122  *
123  * @group is defining the position of a page in a given pair. It can also be
124  * seen as the bit position in the cell: page attached to bit 0 belongs to
125  * group 0, page attached to bit 1 belongs to group 1, etc.
126  *
127  * Example:
128  * The H27UCG8T2BTR-BC datasheet describes the following pairing scheme:
129  *
130  *		group-0		group-1
131  *
132  *  pair-0	page-0		page-4
133  *  pair-1	page-1		page-5
134  *  pair-2	page-2		page-8
135  *  ...
136  *  pair-127	page-251	page-255
137  *
138  *
139  * Note that the "group" and "pair" terms were extracted from Samsung and
140  * Hynix datasheets, and might be referenced under other names in other
141  * datasheets (Micron is describing this concept as "shared pages").
142  */
143 struct mtd_pairing_info {
144 	int pair;
145 	int group;
146 };
147 
148 /**
149  * struct mtd_pairing_scheme - page pairing scheme description
150  *
151  * @ngroups: number of groups. Should be related to the number of bits
152  *	     per cell.
153  * @get_info: converts a write-unit (page number within an erase block) into
154  *	      mtd_pairing information (pair + group). This function should
155  *	      fill the info parameter based on the wunit index or return
156  *	      -EINVAL if the wunit parameter is invalid.
157  * @get_wunit: converts pairing information into a write-unit (page) number.
158  *	       This function should return the wunit index pointed by the
159  *	       pairing information described in the info argument. It should
160  *	       return -EINVAL, if there's no wunit corresponding to the
161  *	       passed pairing information.
162  *
163  * See mtd_pairing_info documentation for a detailed explanation of the
164  * pair and group concepts.
165  *
166  * The mtd_pairing_scheme structure provides a generic solution to represent
167  * NAND page pairing scheme. Instead of exposing two big tables to do the
168  * write-unit <-> (pair + group) conversions, we ask the MTD drivers to
169  * implement the ->get_info() and ->get_wunit() functions.
170  *
171  * MTD users will then be able to query these information by using the
172  * mtd_pairing_info_to_wunit() and mtd_wunit_to_pairing_info() helpers.
173  *
174  * @ngroups is here to help MTD users iterating over all the pages in a
175  * given pair. This value can be retrieved by MTD users using the
176  * mtd_pairing_groups() helper.
177  *
178  * Examples are given in the mtd_pairing_info_to_wunit() and
179  * mtd_wunit_to_pairing_info() documentation.
180  */
181 struct mtd_pairing_scheme {
182 	int ngroups;
183 	int (*get_info)(struct mtd_info *mtd, int wunit,
184 			struct mtd_pairing_info *info);
185 	int (*get_wunit)(struct mtd_info *mtd,
186 			 const struct mtd_pairing_info *info);
187 };
188 
189 struct module;	/* only needed for owner field in mtd_info */
190 
191 /**
192  * struct mtd_debug_info - debugging information for an MTD device.
193  *
194  * @dfs_dir: direntry object of the MTD device debugfs directory
195  */
196 struct mtd_debug_info {
197 	struct dentry *dfs_dir;
198 };
199 
200 /**
201  * struct mtd_part - MTD partition specific fields
202  *
203  * @node: list node used to add an MTD partition to the parent partition list
204  * @offset: offset of the partition relatively to the parent offset
205  * @size: partition size. Should be equal to mtd->size unless
206  *	  MTD_SLC_ON_MLC_EMULATION is set
207  * @flags: original flags (before the mtdpart logic decided to tweak them based
208  *	   on flash constraints, like eraseblock/pagesize alignment)
209  *
210  * This struct is embedded in mtd_info and contains partition-specific
211  * properties/fields.
212  */
213 struct mtd_part {
214 	struct list_head node;
215 	u64 offset;
216 	u64 size;
217 	u32 flags;
218 };
219 
220 /**
221  * struct mtd_master - MTD master specific fields
222  *
223  * @partitions_lock: lock protecting accesses to the partition list. Protects
224  *		     not only the master partition list, but also all
225  *		     sub-partitions.
226  * @suspended: et to 1 when the device is suspended, 0 otherwise
227  *
228  * This struct is embedded in mtd_info and contains master-specific
229  * properties/fields. The master is the root MTD device from the MTD partition
230  * point of view.
231  */
232 struct mtd_master {
233 	struct mutex partitions_lock;
234 	struct mutex chrdev_lock;
235 	unsigned int suspended : 1;
236 };
237 
238 struct mtd_info {
239 	u_char type;
240 	uint32_t flags;
241 	uint64_t size;	 // Total size of the MTD
242 
243 	/* "Major" erase size for the device. Naïve users may take this
244 	 * to be the only erase size available, or may use the more detailed
245 	 * information below if they desire
246 	 */
247 	uint32_t erasesize;
248 	/* Minimal writable flash unit size. In case of NOR flash it is 1 (even
249 	 * though individual bits can be cleared), in case of NAND flash it is
250 	 * one NAND page (or half, or one-fourths of it), in case of ECC-ed NOR
251 	 * it is of ECC block size, etc. It is illegal to have writesize = 0.
252 	 * Any driver registering a struct mtd_info must ensure a writesize of
253 	 * 1 or larger.
254 	 */
255 	uint32_t writesize;
256 
257 	/*
258 	 * Size of the write buffer used by the MTD. MTD devices having a write
259 	 * buffer can write multiple writesize chunks at a time. E.g. while
260 	 * writing 4 * writesize bytes to a device with 2 * writesize bytes
261 	 * buffer the MTD driver can (but doesn't have to) do 2 writesize
262 	 * operations, but not 4. Currently, all NANDs have writebufsize
263 	 * equivalent to writesize (NAND page size). Some NOR flashes do have
264 	 * writebufsize greater than writesize.
265 	 */
266 	uint32_t writebufsize;
267 
268 	uint32_t oobsize;   // Amount of OOB data per block (e.g. 16)
269 	uint32_t oobavail;  // Available OOB bytes per block
270 
271 	/*
272 	 * If erasesize is a power of 2 then the shift is stored in
273 	 * erasesize_shift otherwise erasesize_shift is zero. Ditto writesize.
274 	 */
275 	unsigned int erasesize_shift;
276 	unsigned int writesize_shift;
277 	/* Masks based on erasesize_shift and writesize_shift */
278 	unsigned int erasesize_mask;
279 	unsigned int writesize_mask;
280 
281 	/*
282 	 * read ops return -EUCLEAN if max number of bitflips corrected on any
283 	 * one region comprising an ecc step equals or exceeds this value.
284 	 * Settable by driver, else defaults to ecc_strength.  User can override
285 	 * in sysfs.  N.B. The meaning of the -EUCLEAN return code has changed;
286 	 * see Documentation/ABI/testing/sysfs-class-mtd for more detail.
287 	 */
288 	unsigned int bitflip_threshold;
289 
290 	/* Kernel-only stuff starts here. */
291 	const char *name;
292 	int index;
293 
294 	/* OOB layout description */
295 	const struct mtd_ooblayout_ops *ooblayout;
296 
297 	/* NAND pairing scheme, only provided for MLC/TLC NANDs */
298 	const struct mtd_pairing_scheme *pairing;
299 
300 	/* the ecc step size. */
301 	unsigned int ecc_step_size;
302 
303 	/* max number of correctible bit errors per ecc step */
304 	unsigned int ecc_strength;
305 
306 	/* Data for variable erase regions. If numeraseregions is zero,
307 	 * it means that the whole device has erasesize as given above.
308 	 */
309 	int numeraseregions;
310 	struct mtd_erase_region_info *eraseregions;
311 
312 	/*
313 	 * Do not call via these pointers, use corresponding mtd_*()
314 	 * wrappers instead.
315 	 */
316 	int (*_erase) (struct mtd_info *mtd, struct erase_info *instr);
317 	int (*_point) (struct mtd_info *mtd, loff_t from, size_t len,
318 		       size_t *retlen, void **virt, resource_size_t *phys);
319 	int (*_unpoint) (struct mtd_info *mtd, loff_t from, size_t len);
320 	int (*_read) (struct mtd_info *mtd, loff_t from, size_t len,
321 		      size_t *retlen, u_char *buf);
322 	int (*_write) (struct mtd_info *mtd, loff_t to, size_t len,
323 		       size_t *retlen, const u_char *buf);
324 	int (*_panic_write) (struct mtd_info *mtd, loff_t to, size_t len,
325 			     size_t *retlen, const u_char *buf);
326 	int (*_read_oob) (struct mtd_info *mtd, loff_t from,
327 			  struct mtd_oob_ops *ops);
328 	int (*_write_oob) (struct mtd_info *mtd, loff_t to,
329 			   struct mtd_oob_ops *ops);
330 	int (*_get_fact_prot_info) (struct mtd_info *mtd, size_t len,
331 				    size_t *retlen, struct otp_info *buf);
332 	int (*_read_fact_prot_reg) (struct mtd_info *mtd, loff_t from,
333 				    size_t len, size_t *retlen, u_char *buf);
334 	int (*_get_user_prot_info) (struct mtd_info *mtd, size_t len,
335 				    size_t *retlen, struct otp_info *buf);
336 	int (*_read_user_prot_reg) (struct mtd_info *mtd, loff_t from,
337 				    size_t len, size_t *retlen, u_char *buf);
338 	int (*_write_user_prot_reg) (struct mtd_info *mtd, loff_t to,
339 				     size_t len, size_t *retlen,
340 				     const u_char *buf);
341 	int (*_lock_user_prot_reg) (struct mtd_info *mtd, loff_t from,
342 				    size_t len);
343 	int (*_erase_user_prot_reg) (struct mtd_info *mtd, loff_t from,
344 				     size_t len);
345 	int (*_writev) (struct mtd_info *mtd, const struct kvec *vecs,
346 			unsigned long count, loff_t to, size_t *retlen);
347 	void (*_sync) (struct mtd_info *mtd);
348 	int (*_lock) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
349 	int (*_unlock) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
350 	int (*_is_locked) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
351 	int (*_block_isreserved) (struct mtd_info *mtd, loff_t ofs);
352 	int (*_block_isbad) (struct mtd_info *mtd, loff_t ofs);
353 	int (*_block_markbad) (struct mtd_info *mtd, loff_t ofs);
354 	int (*_max_bad_blocks) (struct mtd_info *mtd, loff_t ofs, size_t len);
355 	int (*_suspend) (struct mtd_info *mtd);
356 	void (*_resume) (struct mtd_info *mtd);
357 	void (*_reboot) (struct mtd_info *mtd);
358 	/*
359 	 * If the driver is something smart, like UBI, it may need to maintain
360 	 * its own reference counting. The below functions are only for driver.
361 	 */
362 	int (*_get_device) (struct mtd_info *mtd);
363 	void (*_put_device) (struct mtd_info *mtd);
364 
365 	/*
366 	 * flag indicates a panic write, low level drivers can take appropriate
367 	 * action if required to ensure writes go through
368 	 */
369 	bool oops_panic_write;
370 
371 	struct notifier_block reboot_notifier;  /* default mode before reboot */
372 
373 	/* ECC status information */
374 	struct mtd_ecc_stats ecc_stats;
375 	/* Subpage shift (NAND) */
376 	int subpage_sft;
377 
378 	void *priv;
379 
380 	struct module *owner;
381 	struct device dev;
382 	int usecount;
383 	struct mtd_debug_info dbg;
384 	struct nvmem_device *nvmem;
385 	struct nvmem_device *otp_user_nvmem;
386 	struct nvmem_device *otp_factory_nvmem;
387 
388 	/*
389 	 * Parent device from the MTD partition point of view.
390 	 *
391 	 * MTD masters do not have any parent, MTD partitions do. The parent
392 	 * MTD device can itself be a partition.
393 	 */
394 	struct mtd_info *parent;
395 
396 	/* List of partitions attached to this MTD device */
397 	struct list_head partitions;
398 
399 	struct mtd_part part;
400 	struct mtd_master master;
401 };
402 
403 static inline struct mtd_info *mtd_get_master(struct mtd_info *mtd)
404 {
405 	while (mtd->parent)
406 		mtd = mtd->parent;
407 
408 	return mtd;
409 }
410 
411 static inline u64 mtd_get_master_ofs(struct mtd_info *mtd, u64 ofs)
412 {
413 	while (mtd->parent) {
414 		ofs += mtd->part.offset;
415 		mtd = mtd->parent;
416 	}
417 
418 	return ofs;
419 }
420 
421 static inline bool mtd_is_partition(const struct mtd_info *mtd)
422 {
423 	return mtd->parent;
424 }
425 
426 static inline bool mtd_has_partitions(const struct mtd_info *mtd)
427 {
428 	return !list_empty(&mtd->partitions);
429 }
430 
431 int mtd_ooblayout_ecc(struct mtd_info *mtd, int section,
432 		      struct mtd_oob_region *oobecc);
433 int mtd_ooblayout_find_eccregion(struct mtd_info *mtd, int eccbyte,
434 				 int *section,
435 				 struct mtd_oob_region *oobregion);
436 int mtd_ooblayout_get_eccbytes(struct mtd_info *mtd, u8 *eccbuf,
437 			       const u8 *oobbuf, int start, int nbytes);
438 int mtd_ooblayout_set_eccbytes(struct mtd_info *mtd, const u8 *eccbuf,
439 			       u8 *oobbuf, int start, int nbytes);
440 int mtd_ooblayout_free(struct mtd_info *mtd, int section,
441 		       struct mtd_oob_region *oobfree);
442 int mtd_ooblayout_get_databytes(struct mtd_info *mtd, u8 *databuf,
443 				const u8 *oobbuf, int start, int nbytes);
444 int mtd_ooblayout_set_databytes(struct mtd_info *mtd, const u8 *databuf,
445 				u8 *oobbuf, int start, int nbytes);
446 int mtd_ooblayout_count_freebytes(struct mtd_info *mtd);
447 int mtd_ooblayout_count_eccbytes(struct mtd_info *mtd);
448 
449 static inline void mtd_set_ooblayout(struct mtd_info *mtd,
450 				     const struct mtd_ooblayout_ops *ooblayout)
451 {
452 	mtd->ooblayout = ooblayout;
453 }
454 
455 static inline void mtd_set_pairing_scheme(struct mtd_info *mtd,
456 				const struct mtd_pairing_scheme *pairing)
457 {
458 	mtd->pairing = pairing;
459 }
460 
461 static inline void mtd_set_of_node(struct mtd_info *mtd,
462 				   struct device_node *np)
463 {
464 	mtd->dev.of_node = np;
465 	if (!mtd->name)
466 		of_property_read_string(np, "label", &mtd->name);
467 }
468 
469 static inline struct device_node *mtd_get_of_node(struct mtd_info *mtd)
470 {
471 	return dev_of_node(&mtd->dev);
472 }
473 
474 static inline u32 mtd_oobavail(struct mtd_info *mtd, struct mtd_oob_ops *ops)
475 {
476 	return ops->mode == MTD_OPS_AUTO_OOB ? mtd->oobavail : mtd->oobsize;
477 }
478 
479 static inline int mtd_max_bad_blocks(struct mtd_info *mtd,
480 				     loff_t ofs, size_t len)
481 {
482 	struct mtd_info *master = mtd_get_master(mtd);
483 
484 	if (!master->_max_bad_blocks)
485 		return -ENOTSUPP;
486 
487 	if (mtd->size < (len + ofs) || ofs < 0)
488 		return -EINVAL;
489 
490 	return master->_max_bad_blocks(master, mtd_get_master_ofs(mtd, ofs),
491 				       len);
492 }
493 
494 int mtd_wunit_to_pairing_info(struct mtd_info *mtd, int wunit,
495 			      struct mtd_pairing_info *info);
496 int mtd_pairing_info_to_wunit(struct mtd_info *mtd,
497 			      const struct mtd_pairing_info *info);
498 int mtd_pairing_groups(struct mtd_info *mtd);
499 int mtd_erase(struct mtd_info *mtd, struct erase_info *instr);
500 int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
501 	      void **virt, resource_size_t *phys);
502 int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len);
503 unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
504 				    unsigned long offset, unsigned long flags);
505 int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
506 	     u_char *buf);
507 int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
508 	      const u_char *buf);
509 int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
510 		    const u_char *buf);
511 
512 int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops);
513 int mtd_write_oob(struct mtd_info *mtd, loff_t to, struct mtd_oob_ops *ops);
514 
515 int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
516 			   struct otp_info *buf);
517 int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
518 			   size_t *retlen, u_char *buf);
519 int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
520 			   struct otp_info *buf);
521 int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
522 			   size_t *retlen, u_char *buf);
523 int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
524 			    size_t *retlen, const u_char *buf);
525 int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len);
526 int mtd_erase_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len);
527 
528 int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
529 	       unsigned long count, loff_t to, size_t *retlen);
530 
531 static inline void mtd_sync(struct mtd_info *mtd)
532 {
533 	struct mtd_info *master = mtd_get_master(mtd);
534 
535 	if (master->_sync)
536 		master->_sync(master);
537 }
538 
539 int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
540 int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
541 int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len);
542 int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs);
543 int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs);
544 int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs);
545 
546 static inline int mtd_suspend(struct mtd_info *mtd)
547 {
548 	struct mtd_info *master = mtd_get_master(mtd);
549 	int ret;
550 
551 	if (master->master.suspended)
552 		return 0;
553 
554 	ret = master->_suspend ? master->_suspend(master) : 0;
555 	if (ret)
556 		return ret;
557 
558 	master->master.suspended = 1;
559 	return 0;
560 }
561 
562 static inline void mtd_resume(struct mtd_info *mtd)
563 {
564 	struct mtd_info *master = mtd_get_master(mtd);
565 
566 	if (!master->master.suspended)
567 		return;
568 
569 	if (master->_resume)
570 		master->_resume(master);
571 
572 	master->master.suspended = 0;
573 }
574 
575 static inline uint32_t mtd_div_by_eb(uint64_t sz, struct mtd_info *mtd)
576 {
577 	if (mtd->erasesize_shift)
578 		return sz >> mtd->erasesize_shift;
579 	do_div(sz, mtd->erasesize);
580 	return sz;
581 }
582 
583 static inline uint32_t mtd_mod_by_eb(uint64_t sz, struct mtd_info *mtd)
584 {
585 	if (mtd->erasesize_shift)
586 		return sz & mtd->erasesize_mask;
587 	return do_div(sz, mtd->erasesize);
588 }
589 
590 /**
591  * mtd_align_erase_req - Adjust an erase request to align things on eraseblock
592  *			 boundaries.
593  * @mtd: the MTD device this erase request applies on
594  * @req: the erase request to adjust
595  *
596  * This function will adjust @req->addr and @req->len to align them on
597  * @mtd->erasesize. Of course we expect @mtd->erasesize to be != 0.
598  */
599 static inline void mtd_align_erase_req(struct mtd_info *mtd,
600 				       struct erase_info *req)
601 {
602 	u32 mod;
603 
604 	if (WARN_ON(!mtd->erasesize))
605 		return;
606 
607 	mod = mtd_mod_by_eb(req->addr, mtd);
608 	if (mod) {
609 		req->addr -= mod;
610 		req->len += mod;
611 	}
612 
613 	mod = mtd_mod_by_eb(req->addr + req->len, mtd);
614 	if (mod)
615 		req->len += mtd->erasesize - mod;
616 }
617 
618 static inline uint32_t mtd_div_by_ws(uint64_t sz, struct mtd_info *mtd)
619 {
620 	if (mtd->writesize_shift)
621 		return sz >> mtd->writesize_shift;
622 	do_div(sz, mtd->writesize);
623 	return sz;
624 }
625 
626 static inline uint32_t mtd_mod_by_ws(uint64_t sz, struct mtd_info *mtd)
627 {
628 	if (mtd->writesize_shift)
629 		return sz & mtd->writesize_mask;
630 	return do_div(sz, mtd->writesize);
631 }
632 
633 static inline int mtd_wunit_per_eb(struct mtd_info *mtd)
634 {
635 	struct mtd_info *master = mtd_get_master(mtd);
636 
637 	return master->erasesize / mtd->writesize;
638 }
639 
640 static inline int mtd_offset_to_wunit(struct mtd_info *mtd, loff_t offs)
641 {
642 	return mtd_div_by_ws(mtd_mod_by_eb(offs, mtd), mtd);
643 }
644 
645 static inline loff_t mtd_wunit_to_offset(struct mtd_info *mtd, loff_t base,
646 					 int wunit)
647 {
648 	return base + (wunit * mtd->writesize);
649 }
650 
651 
652 static inline int mtd_has_oob(const struct mtd_info *mtd)
653 {
654 	struct mtd_info *master = mtd_get_master((struct mtd_info *)mtd);
655 
656 	return master->_read_oob && master->_write_oob;
657 }
658 
659 static inline int mtd_type_is_nand(const struct mtd_info *mtd)
660 {
661 	return mtd->type == MTD_NANDFLASH || mtd->type == MTD_MLCNANDFLASH;
662 }
663 
664 static inline int mtd_can_have_bb(const struct mtd_info *mtd)
665 {
666 	struct mtd_info *master = mtd_get_master((struct mtd_info *)mtd);
667 
668 	return !!master->_block_isbad;
669 }
670 
671 	/* Kernel-side ioctl definitions */
672 
673 struct mtd_partition;
674 struct mtd_part_parser_data;
675 
676 extern int mtd_device_parse_register(struct mtd_info *mtd,
677 				     const char * const *part_probe_types,
678 				     struct mtd_part_parser_data *parser_data,
679 				     const struct mtd_partition *defparts,
680 				     int defnr_parts);
681 #define mtd_device_register(master, parts, nr_parts)	\
682 	mtd_device_parse_register(master, NULL, NULL, parts, nr_parts)
683 extern int mtd_device_unregister(struct mtd_info *master);
684 extern struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num);
685 extern int __get_mtd_device(struct mtd_info *mtd);
686 extern void __put_mtd_device(struct mtd_info *mtd);
687 extern struct mtd_info *of_get_mtd_device_by_node(struct device_node *np);
688 extern struct mtd_info *get_mtd_device_nm(const char *name);
689 extern void put_mtd_device(struct mtd_info *mtd);
690 
691 
692 struct mtd_notifier {
693 	void (*add)(struct mtd_info *mtd);
694 	void (*remove)(struct mtd_info *mtd);
695 	struct list_head list;
696 };
697 
698 
699 extern void register_mtd_user (struct mtd_notifier *new);
700 extern int unregister_mtd_user (struct mtd_notifier *old);
701 void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size);
702 
703 static inline int mtd_is_bitflip(int err) {
704 	return err == -EUCLEAN;
705 }
706 
707 static inline int mtd_is_eccerr(int err) {
708 	return err == -EBADMSG;
709 }
710 
711 static inline int mtd_is_bitflip_or_eccerr(int err) {
712 	return mtd_is_bitflip(err) || mtd_is_eccerr(err);
713 }
714 
715 unsigned mtd_mmap_capabilities(struct mtd_info *mtd);
716 
717 #ifdef CONFIG_DEBUG_FS
718 bool mtd_check_expert_analysis_mode(void);
719 #else
720 static inline bool mtd_check_expert_analysis_mode(void) { return false; }
721 #endif
722 
723 
724 #endif /* __MTD_MTD_H__ */
725