xref: /linux/drivers/mtd/mtdpart.c (revision fd639726bf15fca8ee1a00dce8e0096d0ad9bd18)
1 /*
2  * Simple MTD partitioning layer
3  *
4  * Copyright © 2000 Nicolas Pitre <nico@fluxnic.net>
5  * Copyright © 2002 Thomas Gleixner <gleixner@linutronix.de>
6  * Copyright © 2000-2010 David Woodhouse <dwmw2@infradead.org>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
21  *
22  */
23 
24 #include <linux/module.h>
25 #include <linux/types.h>
26 #include <linux/kernel.h>
27 #include <linux/slab.h>
28 #include <linux/list.h>
29 #include <linux/kmod.h>
30 #include <linux/mtd/mtd.h>
31 #include <linux/mtd/partitions.h>
32 #include <linux/err.h>
33 
34 #include "mtdcore.h"
35 
36 /* Our partition linked list */
37 static LIST_HEAD(mtd_partitions);
38 static DEFINE_MUTEX(mtd_partitions_mutex);
39 
40 /**
41  * struct mtd_part - our partition node structure
42  *
43  * @mtd: struct holding partition details
44  * @parent: parent mtd - flash device or another partition
45  * @offset: partition offset relative to the *flash device*
46  */
47 struct mtd_part {
48 	struct mtd_info mtd;
49 	struct mtd_info *parent;
50 	uint64_t offset;
51 	struct list_head list;
52 };
53 
54 /*
55  * Given a pointer to the MTD object in the mtd_part structure, we can retrieve
56  * the pointer to that structure.
57  */
58 static inline struct mtd_part *mtd_to_part(const struct mtd_info *mtd)
59 {
60 	return container_of(mtd, struct mtd_part, mtd);
61 }
62 
63 
64 /*
65  * MTD methods which simply translate the effective address and pass through
66  * to the _real_ device.
67  */
68 
69 static int part_read(struct mtd_info *mtd, loff_t from, size_t len,
70 		size_t *retlen, u_char *buf)
71 {
72 	struct mtd_part *part = mtd_to_part(mtd);
73 	struct mtd_ecc_stats stats;
74 	int res;
75 
76 	stats = part->parent->ecc_stats;
77 	res = part->parent->_read(part->parent, from + part->offset, len,
78 				  retlen, buf);
79 	if (unlikely(mtd_is_eccerr(res)))
80 		mtd->ecc_stats.failed +=
81 			part->parent->ecc_stats.failed - stats.failed;
82 	else
83 		mtd->ecc_stats.corrected +=
84 			part->parent->ecc_stats.corrected - stats.corrected;
85 	return res;
86 }
87 
88 static int part_point(struct mtd_info *mtd, loff_t from, size_t len,
89 		size_t *retlen, void **virt, resource_size_t *phys)
90 {
91 	struct mtd_part *part = mtd_to_part(mtd);
92 
93 	return part->parent->_point(part->parent, from + part->offset, len,
94 				    retlen, virt, phys);
95 }
96 
97 static int part_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
98 {
99 	struct mtd_part *part = mtd_to_part(mtd);
100 
101 	return part->parent->_unpoint(part->parent, from + part->offset, len);
102 }
103 
104 static int part_read_oob(struct mtd_info *mtd, loff_t from,
105 		struct mtd_oob_ops *ops)
106 {
107 	struct mtd_part *part = mtd_to_part(mtd);
108 	int res;
109 
110 	if (from >= mtd->size)
111 		return -EINVAL;
112 	if (ops->datbuf && from + ops->len > mtd->size)
113 		return -EINVAL;
114 
115 	/*
116 	 * If OOB is also requested, make sure that we do not read past the end
117 	 * of this partition.
118 	 */
119 	if (ops->oobbuf) {
120 		size_t len, pages;
121 
122 		len = mtd_oobavail(mtd, ops);
123 		pages = mtd_div_by_ws(mtd->size, mtd);
124 		pages -= mtd_div_by_ws(from, mtd);
125 		if (ops->ooboffs + ops->ooblen > pages * len)
126 			return -EINVAL;
127 	}
128 
129 	res = part->parent->_read_oob(part->parent, from + part->offset, ops);
130 	if (unlikely(res)) {
131 		if (mtd_is_bitflip(res))
132 			mtd->ecc_stats.corrected++;
133 		if (mtd_is_eccerr(res))
134 			mtd->ecc_stats.failed++;
135 	}
136 	return res;
137 }
138 
139 static int part_read_user_prot_reg(struct mtd_info *mtd, loff_t from,
140 		size_t len, size_t *retlen, u_char *buf)
141 {
142 	struct mtd_part *part = mtd_to_part(mtd);
143 	return part->parent->_read_user_prot_reg(part->parent, from, len,
144 						 retlen, buf);
145 }
146 
147 static int part_get_user_prot_info(struct mtd_info *mtd, size_t len,
148 				   size_t *retlen, struct otp_info *buf)
149 {
150 	struct mtd_part *part = mtd_to_part(mtd);
151 	return part->parent->_get_user_prot_info(part->parent, len, retlen,
152 						 buf);
153 }
154 
155 static int part_read_fact_prot_reg(struct mtd_info *mtd, loff_t from,
156 		size_t len, size_t *retlen, u_char *buf)
157 {
158 	struct mtd_part *part = mtd_to_part(mtd);
159 	return part->parent->_read_fact_prot_reg(part->parent, from, len,
160 						 retlen, buf);
161 }
162 
163 static int part_get_fact_prot_info(struct mtd_info *mtd, size_t len,
164 				   size_t *retlen, struct otp_info *buf)
165 {
166 	struct mtd_part *part = mtd_to_part(mtd);
167 	return part->parent->_get_fact_prot_info(part->parent, len, retlen,
168 						 buf);
169 }
170 
171 static int part_write(struct mtd_info *mtd, loff_t to, size_t len,
172 		size_t *retlen, const u_char *buf)
173 {
174 	struct mtd_part *part = mtd_to_part(mtd);
175 	return part->parent->_write(part->parent, to + part->offset, len,
176 				    retlen, buf);
177 }
178 
179 static int part_panic_write(struct mtd_info *mtd, loff_t to, size_t len,
180 		size_t *retlen, const u_char *buf)
181 {
182 	struct mtd_part *part = mtd_to_part(mtd);
183 	return part->parent->_panic_write(part->parent, to + part->offset, len,
184 					  retlen, buf);
185 }
186 
187 static int part_write_oob(struct mtd_info *mtd, loff_t to,
188 		struct mtd_oob_ops *ops)
189 {
190 	struct mtd_part *part = mtd_to_part(mtd);
191 
192 	if (to >= mtd->size)
193 		return -EINVAL;
194 	if (ops->datbuf && to + ops->len > mtd->size)
195 		return -EINVAL;
196 	return part->parent->_write_oob(part->parent, to + part->offset, ops);
197 }
198 
199 static int part_write_user_prot_reg(struct mtd_info *mtd, loff_t from,
200 		size_t len, size_t *retlen, u_char *buf)
201 {
202 	struct mtd_part *part = mtd_to_part(mtd);
203 	return part->parent->_write_user_prot_reg(part->parent, from, len,
204 						  retlen, buf);
205 }
206 
207 static int part_lock_user_prot_reg(struct mtd_info *mtd, loff_t from,
208 		size_t len)
209 {
210 	struct mtd_part *part = mtd_to_part(mtd);
211 	return part->parent->_lock_user_prot_reg(part->parent, from, len);
212 }
213 
214 static int part_writev(struct mtd_info *mtd, const struct kvec *vecs,
215 		unsigned long count, loff_t to, size_t *retlen)
216 {
217 	struct mtd_part *part = mtd_to_part(mtd);
218 	return part->parent->_writev(part->parent, vecs, count,
219 				     to + part->offset, retlen);
220 }
221 
222 static int part_erase(struct mtd_info *mtd, struct erase_info *instr)
223 {
224 	struct mtd_part *part = mtd_to_part(mtd);
225 	int ret;
226 
227 	instr->addr += part->offset;
228 	ret = part->parent->_erase(part->parent, instr);
229 	if (ret) {
230 		if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
231 			instr->fail_addr -= part->offset;
232 		instr->addr -= part->offset;
233 	}
234 	return ret;
235 }
236 
237 void mtd_erase_callback(struct erase_info *instr)
238 {
239 	if (instr->mtd->_erase == part_erase) {
240 		struct mtd_part *part = mtd_to_part(instr->mtd);
241 
242 		if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
243 			instr->fail_addr -= part->offset;
244 		instr->addr -= part->offset;
245 	}
246 	if (instr->callback)
247 		instr->callback(instr);
248 }
249 EXPORT_SYMBOL_GPL(mtd_erase_callback);
250 
251 static int part_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
252 {
253 	struct mtd_part *part = mtd_to_part(mtd);
254 	return part->parent->_lock(part->parent, ofs + part->offset, len);
255 }
256 
257 static int part_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
258 {
259 	struct mtd_part *part = mtd_to_part(mtd);
260 	return part->parent->_unlock(part->parent, ofs + part->offset, len);
261 }
262 
263 static int part_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
264 {
265 	struct mtd_part *part = mtd_to_part(mtd);
266 	return part->parent->_is_locked(part->parent, ofs + part->offset, len);
267 }
268 
269 static void part_sync(struct mtd_info *mtd)
270 {
271 	struct mtd_part *part = mtd_to_part(mtd);
272 	part->parent->_sync(part->parent);
273 }
274 
275 static int part_suspend(struct mtd_info *mtd)
276 {
277 	struct mtd_part *part = mtd_to_part(mtd);
278 	return part->parent->_suspend(part->parent);
279 }
280 
281 static void part_resume(struct mtd_info *mtd)
282 {
283 	struct mtd_part *part = mtd_to_part(mtd);
284 	part->parent->_resume(part->parent);
285 }
286 
287 static int part_block_isreserved(struct mtd_info *mtd, loff_t ofs)
288 {
289 	struct mtd_part *part = mtd_to_part(mtd);
290 	ofs += part->offset;
291 	return part->parent->_block_isreserved(part->parent, ofs);
292 }
293 
294 static int part_block_isbad(struct mtd_info *mtd, loff_t ofs)
295 {
296 	struct mtd_part *part = mtd_to_part(mtd);
297 	ofs += part->offset;
298 	return part->parent->_block_isbad(part->parent, ofs);
299 }
300 
301 static int part_block_markbad(struct mtd_info *mtd, loff_t ofs)
302 {
303 	struct mtd_part *part = mtd_to_part(mtd);
304 	int res;
305 
306 	ofs += part->offset;
307 	res = part->parent->_block_markbad(part->parent, ofs);
308 	if (!res)
309 		mtd->ecc_stats.badblocks++;
310 	return res;
311 }
312 
313 static int part_get_device(struct mtd_info *mtd)
314 {
315 	struct mtd_part *part = mtd_to_part(mtd);
316 	return part->parent->_get_device(part->parent);
317 }
318 
319 static void part_put_device(struct mtd_info *mtd)
320 {
321 	struct mtd_part *part = mtd_to_part(mtd);
322 	part->parent->_put_device(part->parent);
323 }
324 
325 static int part_ooblayout_ecc(struct mtd_info *mtd, int section,
326 			      struct mtd_oob_region *oobregion)
327 {
328 	struct mtd_part *part = mtd_to_part(mtd);
329 
330 	return mtd_ooblayout_ecc(part->parent, section, oobregion);
331 }
332 
333 static int part_ooblayout_free(struct mtd_info *mtd, int section,
334 			       struct mtd_oob_region *oobregion)
335 {
336 	struct mtd_part *part = mtd_to_part(mtd);
337 
338 	return mtd_ooblayout_free(part->parent, section, oobregion);
339 }
340 
341 static const struct mtd_ooblayout_ops part_ooblayout_ops = {
342 	.ecc = part_ooblayout_ecc,
343 	.free = part_ooblayout_free,
344 };
345 
346 static int part_max_bad_blocks(struct mtd_info *mtd, loff_t ofs, size_t len)
347 {
348 	struct mtd_part *part = mtd_to_part(mtd);
349 
350 	return part->parent->_max_bad_blocks(part->parent,
351 					     ofs + part->offset, len);
352 }
353 
354 static inline void free_partition(struct mtd_part *p)
355 {
356 	kfree(p->mtd.name);
357 	kfree(p);
358 }
359 
360 /**
361  * mtd_parse_part - parse MTD partition looking for subpartitions
362  *
363  * @slave: part that is supposed to be a container and should be parsed
364  * @types: NULL-terminated array with names of partition parsers to try
365  *
366  * Some partitions are kind of containers with extra subpartitions (volumes).
367  * There can be various formats of such containers. This function tries to use
368  * specified parsers to analyze given partition and registers found
369  * subpartitions on success.
370  */
371 static int mtd_parse_part(struct mtd_part *slave, const char *const *types)
372 {
373 	struct mtd_partitions parsed;
374 	int err;
375 
376 	err = parse_mtd_partitions(&slave->mtd, types, &parsed, NULL);
377 	if (err)
378 		return err;
379 	else if (!parsed.nr_parts)
380 		return -ENOENT;
381 
382 	err = add_mtd_partitions(&slave->mtd, parsed.parts, parsed.nr_parts);
383 
384 	mtd_part_parser_cleanup(&parsed);
385 
386 	return err;
387 }
388 
389 static struct mtd_part *allocate_partition(struct mtd_info *parent,
390 			const struct mtd_partition *part, int partno,
391 			uint64_t cur_offset)
392 {
393 	int wr_alignment = (parent->flags & MTD_NO_ERASE) ? parent->writesize :
394 							    parent->erasesize;
395 	struct mtd_part *slave;
396 	u32 remainder;
397 	char *name;
398 	u64 tmp;
399 
400 	/* allocate the partition structure */
401 	slave = kzalloc(sizeof(*slave), GFP_KERNEL);
402 	name = kstrdup(part->name, GFP_KERNEL);
403 	if (!name || !slave) {
404 		printk(KERN_ERR"memory allocation error while creating partitions for \"%s\"\n",
405 		       parent->name);
406 		kfree(name);
407 		kfree(slave);
408 		return ERR_PTR(-ENOMEM);
409 	}
410 
411 	/* set up the MTD object for this partition */
412 	slave->mtd.type = parent->type;
413 	slave->mtd.flags = parent->flags & ~part->mask_flags;
414 	slave->mtd.size = part->size;
415 	slave->mtd.writesize = parent->writesize;
416 	slave->mtd.writebufsize = parent->writebufsize;
417 	slave->mtd.oobsize = parent->oobsize;
418 	slave->mtd.oobavail = parent->oobavail;
419 	slave->mtd.subpage_sft = parent->subpage_sft;
420 	slave->mtd.pairing = parent->pairing;
421 
422 	slave->mtd.name = name;
423 	slave->mtd.owner = parent->owner;
424 
425 	/* NOTE: Historically, we didn't arrange MTDs as a tree out of
426 	 * concern for showing the same data in multiple partitions.
427 	 * However, it is very useful to have the master node present,
428 	 * so the MTD_PARTITIONED_MASTER option allows that. The master
429 	 * will have device nodes etc only if this is set, so make the
430 	 * parent conditional on that option. Note, this is a way to
431 	 * distinguish between the master and the partition in sysfs.
432 	 */
433 	slave->mtd.dev.parent = IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER) || mtd_is_partition(parent) ?
434 				&parent->dev :
435 				parent->dev.parent;
436 	slave->mtd.dev.of_node = part->of_node;
437 
438 	slave->mtd._read = part_read;
439 	slave->mtd._write = part_write;
440 
441 	if (parent->_panic_write)
442 		slave->mtd._panic_write = part_panic_write;
443 
444 	if (parent->_point && parent->_unpoint) {
445 		slave->mtd._point = part_point;
446 		slave->mtd._unpoint = part_unpoint;
447 	}
448 
449 	if (parent->_read_oob)
450 		slave->mtd._read_oob = part_read_oob;
451 	if (parent->_write_oob)
452 		slave->mtd._write_oob = part_write_oob;
453 	if (parent->_read_user_prot_reg)
454 		slave->mtd._read_user_prot_reg = part_read_user_prot_reg;
455 	if (parent->_read_fact_prot_reg)
456 		slave->mtd._read_fact_prot_reg = part_read_fact_prot_reg;
457 	if (parent->_write_user_prot_reg)
458 		slave->mtd._write_user_prot_reg = part_write_user_prot_reg;
459 	if (parent->_lock_user_prot_reg)
460 		slave->mtd._lock_user_prot_reg = part_lock_user_prot_reg;
461 	if (parent->_get_user_prot_info)
462 		slave->mtd._get_user_prot_info = part_get_user_prot_info;
463 	if (parent->_get_fact_prot_info)
464 		slave->mtd._get_fact_prot_info = part_get_fact_prot_info;
465 	if (parent->_sync)
466 		slave->mtd._sync = part_sync;
467 	if (!partno && !parent->dev.class && parent->_suspend &&
468 	    parent->_resume) {
469 		slave->mtd._suspend = part_suspend;
470 		slave->mtd._resume = part_resume;
471 	}
472 	if (parent->_writev)
473 		slave->mtd._writev = part_writev;
474 	if (parent->_lock)
475 		slave->mtd._lock = part_lock;
476 	if (parent->_unlock)
477 		slave->mtd._unlock = part_unlock;
478 	if (parent->_is_locked)
479 		slave->mtd._is_locked = part_is_locked;
480 	if (parent->_block_isreserved)
481 		slave->mtd._block_isreserved = part_block_isreserved;
482 	if (parent->_block_isbad)
483 		slave->mtd._block_isbad = part_block_isbad;
484 	if (parent->_block_markbad)
485 		slave->mtd._block_markbad = part_block_markbad;
486 	if (parent->_max_bad_blocks)
487 		slave->mtd._max_bad_blocks = part_max_bad_blocks;
488 
489 	if (parent->_get_device)
490 		slave->mtd._get_device = part_get_device;
491 	if (parent->_put_device)
492 		slave->mtd._put_device = part_put_device;
493 
494 	slave->mtd._erase = part_erase;
495 	slave->parent = parent;
496 	slave->offset = part->offset;
497 
498 	if (slave->offset == MTDPART_OFS_APPEND)
499 		slave->offset = cur_offset;
500 	if (slave->offset == MTDPART_OFS_NXTBLK) {
501 		tmp = cur_offset;
502 		slave->offset = cur_offset;
503 		remainder = do_div(tmp, wr_alignment);
504 		if (remainder) {
505 			slave->offset += wr_alignment - remainder;
506 			printk(KERN_NOTICE "Moving partition %d: "
507 			       "0x%012llx -> 0x%012llx\n", partno,
508 			       (unsigned long long)cur_offset, (unsigned long long)slave->offset);
509 		}
510 	}
511 	if (slave->offset == MTDPART_OFS_RETAIN) {
512 		slave->offset = cur_offset;
513 		if (parent->size - slave->offset >= slave->mtd.size) {
514 			slave->mtd.size = parent->size - slave->offset
515 							- slave->mtd.size;
516 		} else {
517 			printk(KERN_ERR "mtd partition \"%s\" doesn't have enough space: %#llx < %#llx, disabled\n",
518 				part->name, parent->size - slave->offset,
519 				slave->mtd.size);
520 			/* register to preserve ordering */
521 			goto out_register;
522 		}
523 	}
524 	if (slave->mtd.size == MTDPART_SIZ_FULL)
525 		slave->mtd.size = parent->size - slave->offset;
526 
527 	printk(KERN_NOTICE "0x%012llx-0x%012llx : \"%s\"\n", (unsigned long long)slave->offset,
528 		(unsigned long long)(slave->offset + slave->mtd.size), slave->mtd.name);
529 
530 	/* let's do some sanity checks */
531 	if (slave->offset >= parent->size) {
532 		/* let's register it anyway to preserve ordering */
533 		slave->offset = 0;
534 		slave->mtd.size = 0;
535 		printk(KERN_ERR"mtd: partition \"%s\" is out of reach -- disabled\n",
536 			part->name);
537 		goto out_register;
538 	}
539 	if (slave->offset + slave->mtd.size > parent->size) {
540 		slave->mtd.size = parent->size - slave->offset;
541 		printk(KERN_WARNING"mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#llx\n",
542 			part->name, parent->name, (unsigned long long)slave->mtd.size);
543 	}
544 	if (parent->numeraseregions > 1) {
545 		/* Deal with variable erase size stuff */
546 		int i, max = parent->numeraseregions;
547 		u64 end = slave->offset + slave->mtd.size;
548 		struct mtd_erase_region_info *regions = parent->eraseregions;
549 
550 		/* Find the first erase regions which is part of this
551 		 * partition. */
552 		for (i = 0; i < max && regions[i].offset <= slave->offset; i++)
553 			;
554 		/* The loop searched for the region _behind_ the first one */
555 		if (i > 0)
556 			i--;
557 
558 		/* Pick biggest erasesize */
559 		for (; i < max && regions[i].offset < end; i++) {
560 			if (slave->mtd.erasesize < regions[i].erasesize) {
561 				slave->mtd.erasesize = regions[i].erasesize;
562 			}
563 		}
564 		BUG_ON(slave->mtd.erasesize == 0);
565 	} else {
566 		/* Single erase size */
567 		slave->mtd.erasesize = parent->erasesize;
568 	}
569 
570 	/*
571 	 * Slave erasesize might differ from the master one if the master
572 	 * exposes several regions with different erasesize. Adjust
573 	 * wr_alignment accordingly.
574 	 */
575 	if (!(slave->mtd.flags & MTD_NO_ERASE))
576 		wr_alignment = slave->mtd.erasesize;
577 
578 	tmp = slave->offset;
579 	remainder = do_div(tmp, wr_alignment);
580 	if ((slave->mtd.flags & MTD_WRITEABLE) && remainder) {
581 		/* Doesn't start on a boundary of major erase size */
582 		/* FIXME: Let it be writable if it is on a boundary of
583 		 * _minor_ erase size though */
584 		slave->mtd.flags &= ~MTD_WRITEABLE;
585 		printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase/write block boundary -- force read-only\n",
586 			part->name);
587 	}
588 
589 	tmp = slave->mtd.size;
590 	remainder = do_div(tmp, wr_alignment);
591 	if ((slave->mtd.flags & MTD_WRITEABLE) && remainder) {
592 		slave->mtd.flags &= ~MTD_WRITEABLE;
593 		printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase/write block -- force read-only\n",
594 			part->name);
595 	}
596 
597 	mtd_set_ooblayout(&slave->mtd, &part_ooblayout_ops);
598 	slave->mtd.ecc_step_size = parent->ecc_step_size;
599 	slave->mtd.ecc_strength = parent->ecc_strength;
600 	slave->mtd.bitflip_threshold = parent->bitflip_threshold;
601 
602 	if (parent->_block_isbad) {
603 		uint64_t offs = 0;
604 
605 		while (offs < slave->mtd.size) {
606 			if (mtd_block_isreserved(parent, offs + slave->offset))
607 				slave->mtd.ecc_stats.bbtblocks++;
608 			else if (mtd_block_isbad(parent, offs + slave->offset))
609 				slave->mtd.ecc_stats.badblocks++;
610 			offs += slave->mtd.erasesize;
611 		}
612 	}
613 
614 out_register:
615 	return slave;
616 }
617 
618 static ssize_t mtd_partition_offset_show(struct device *dev,
619 		struct device_attribute *attr, char *buf)
620 {
621 	struct mtd_info *mtd = dev_get_drvdata(dev);
622 	struct mtd_part *part = mtd_to_part(mtd);
623 	return snprintf(buf, PAGE_SIZE, "%lld\n", part->offset);
624 }
625 
626 static DEVICE_ATTR(offset, S_IRUGO, mtd_partition_offset_show, NULL);
627 
628 static const struct attribute *mtd_partition_attrs[] = {
629 	&dev_attr_offset.attr,
630 	NULL
631 };
632 
633 static int mtd_add_partition_attrs(struct mtd_part *new)
634 {
635 	int ret = sysfs_create_files(&new->mtd.dev.kobj, mtd_partition_attrs);
636 	if (ret)
637 		printk(KERN_WARNING
638 		       "mtd: failed to create partition attrs, err=%d\n", ret);
639 	return ret;
640 }
641 
642 int mtd_add_partition(struct mtd_info *parent, const char *name,
643 		      long long offset, long long length)
644 {
645 	struct mtd_partition part;
646 	struct mtd_part *new;
647 	int ret = 0;
648 
649 	/* the direct offset is expected */
650 	if (offset == MTDPART_OFS_APPEND ||
651 	    offset == MTDPART_OFS_NXTBLK)
652 		return -EINVAL;
653 
654 	if (length == MTDPART_SIZ_FULL)
655 		length = parent->size - offset;
656 
657 	if (length <= 0)
658 		return -EINVAL;
659 
660 	memset(&part, 0, sizeof(part));
661 	part.name = name;
662 	part.size = length;
663 	part.offset = offset;
664 
665 	new = allocate_partition(parent, &part, -1, offset);
666 	if (IS_ERR(new))
667 		return PTR_ERR(new);
668 
669 	mutex_lock(&mtd_partitions_mutex);
670 	list_add(&new->list, &mtd_partitions);
671 	mutex_unlock(&mtd_partitions_mutex);
672 
673 	add_mtd_device(&new->mtd);
674 
675 	mtd_add_partition_attrs(new);
676 
677 	return ret;
678 }
679 EXPORT_SYMBOL_GPL(mtd_add_partition);
680 
681 /**
682  * __mtd_del_partition - delete MTD partition
683  *
684  * @priv: internal MTD struct for partition to be deleted
685  *
686  * This function must be called with the partitions mutex locked.
687  */
688 static int __mtd_del_partition(struct mtd_part *priv)
689 {
690 	struct mtd_part *child, *next;
691 	int err;
692 
693 	list_for_each_entry_safe(child, next, &mtd_partitions, list) {
694 		if (child->parent == &priv->mtd) {
695 			err = __mtd_del_partition(child);
696 			if (err)
697 				return err;
698 		}
699 	}
700 
701 	sysfs_remove_files(&priv->mtd.dev.kobj, mtd_partition_attrs);
702 
703 	err = del_mtd_device(&priv->mtd);
704 	if (err)
705 		return err;
706 
707 	list_del(&priv->list);
708 	free_partition(priv);
709 
710 	return 0;
711 }
712 
713 /*
714  * This function unregisters and destroy all slave MTD objects which are
715  * attached to the given MTD object.
716  */
717 int del_mtd_partitions(struct mtd_info *mtd)
718 {
719 	struct mtd_part *slave, *next;
720 	int ret, err = 0;
721 
722 	mutex_lock(&mtd_partitions_mutex);
723 	list_for_each_entry_safe(slave, next, &mtd_partitions, list)
724 		if (slave->parent == mtd) {
725 			ret = __mtd_del_partition(slave);
726 			if (ret < 0)
727 				err = ret;
728 		}
729 	mutex_unlock(&mtd_partitions_mutex);
730 
731 	return err;
732 }
733 
734 int mtd_del_partition(struct mtd_info *mtd, int partno)
735 {
736 	struct mtd_part *slave, *next;
737 	int ret = -EINVAL;
738 
739 	mutex_lock(&mtd_partitions_mutex);
740 	list_for_each_entry_safe(slave, next, &mtd_partitions, list)
741 		if ((slave->parent == mtd) &&
742 		    (slave->mtd.index == partno)) {
743 			ret = __mtd_del_partition(slave);
744 			break;
745 		}
746 	mutex_unlock(&mtd_partitions_mutex);
747 
748 	return ret;
749 }
750 EXPORT_SYMBOL_GPL(mtd_del_partition);
751 
752 /*
753  * This function, given a master MTD object and a partition table, creates
754  * and registers slave MTD objects which are bound to the master according to
755  * the partition definitions.
756  *
757  * For historical reasons, this function's caller only registers the master
758  * if the MTD_PARTITIONED_MASTER config option is set.
759  */
760 
761 int add_mtd_partitions(struct mtd_info *master,
762 		       const struct mtd_partition *parts,
763 		       int nbparts)
764 {
765 	struct mtd_part *slave;
766 	uint64_t cur_offset = 0;
767 	int i;
768 
769 	printk(KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);
770 
771 	for (i = 0; i < nbparts; i++) {
772 		slave = allocate_partition(master, parts + i, i, cur_offset);
773 		if (IS_ERR(slave)) {
774 			del_mtd_partitions(master);
775 			return PTR_ERR(slave);
776 		}
777 
778 		mutex_lock(&mtd_partitions_mutex);
779 		list_add(&slave->list, &mtd_partitions);
780 		mutex_unlock(&mtd_partitions_mutex);
781 
782 		add_mtd_device(&slave->mtd);
783 		mtd_add_partition_attrs(slave);
784 		if (parts[i].types)
785 			mtd_parse_part(slave, parts[i].types);
786 
787 		cur_offset = slave->offset + slave->mtd.size;
788 	}
789 
790 	return 0;
791 }
792 
793 static DEFINE_SPINLOCK(part_parser_lock);
794 static LIST_HEAD(part_parsers);
795 
796 static struct mtd_part_parser *mtd_part_parser_get(const char *name)
797 {
798 	struct mtd_part_parser *p, *ret = NULL;
799 
800 	spin_lock(&part_parser_lock);
801 
802 	list_for_each_entry(p, &part_parsers, list)
803 		if (!strcmp(p->name, name) && try_module_get(p->owner)) {
804 			ret = p;
805 			break;
806 		}
807 
808 	spin_unlock(&part_parser_lock);
809 
810 	return ret;
811 }
812 
813 static inline void mtd_part_parser_put(const struct mtd_part_parser *p)
814 {
815 	module_put(p->owner);
816 }
817 
818 /*
819  * Many partition parsers just expected the core to kfree() all their data in
820  * one chunk. Do that by default.
821  */
822 static void mtd_part_parser_cleanup_default(const struct mtd_partition *pparts,
823 					    int nr_parts)
824 {
825 	kfree(pparts);
826 }
827 
828 int __register_mtd_parser(struct mtd_part_parser *p, struct module *owner)
829 {
830 	p->owner = owner;
831 
832 	if (!p->cleanup)
833 		p->cleanup = &mtd_part_parser_cleanup_default;
834 
835 	spin_lock(&part_parser_lock);
836 	list_add(&p->list, &part_parsers);
837 	spin_unlock(&part_parser_lock);
838 
839 	return 0;
840 }
841 EXPORT_SYMBOL_GPL(__register_mtd_parser);
842 
843 void deregister_mtd_parser(struct mtd_part_parser *p)
844 {
845 	spin_lock(&part_parser_lock);
846 	list_del(&p->list);
847 	spin_unlock(&part_parser_lock);
848 }
849 EXPORT_SYMBOL_GPL(deregister_mtd_parser);
850 
851 /*
852  * Do not forget to update 'parse_mtd_partitions()' kerneldoc comment if you
853  * are changing this array!
854  */
855 static const char * const default_mtd_part_types[] = {
856 	"cmdlinepart",
857 	"ofpart",
858 	NULL
859 };
860 
861 static int mtd_part_do_parse(struct mtd_part_parser *parser,
862 			     struct mtd_info *master,
863 			     struct mtd_partitions *pparts,
864 			     struct mtd_part_parser_data *data)
865 {
866 	int ret;
867 
868 	ret = (*parser->parse_fn)(master, &pparts->parts, data);
869 	pr_debug("%s: parser %s: %i\n", master->name, parser->name, ret);
870 	if (ret <= 0)
871 		return ret;
872 
873 	pr_notice("%d %s partitions found on MTD device %s\n", ret,
874 		  parser->name, master->name);
875 
876 	pparts->nr_parts = ret;
877 	pparts->parser = parser;
878 
879 	return ret;
880 }
881 
882 /**
883  * parse_mtd_partitions - parse MTD partitions
884  * @master: the master partition (describes whole MTD device)
885  * @types: names of partition parsers to try or %NULL
886  * @pparts: info about partitions found is returned here
887  * @data: MTD partition parser-specific data
888  *
889  * This function tries to find partition on MTD device @master. It uses MTD
890  * partition parsers, specified in @types. However, if @types is %NULL, then
891  * the default list of parsers is used. The default list contains only the
892  * "cmdlinepart" and "ofpart" parsers ATM.
893  * Note: If there are more then one parser in @types, the kernel only takes the
894  * partitions parsed out by the first parser.
895  *
896  * This function may return:
897  * o a negative error code in case of failure
898  * o zero otherwise, and @pparts will describe the partitions, number of
899  *   partitions, and the parser which parsed them. Caller must release
900  *   resources with mtd_part_parser_cleanup() when finished with the returned
901  *   data.
902  */
903 int parse_mtd_partitions(struct mtd_info *master, const char *const *types,
904 			 struct mtd_partitions *pparts,
905 			 struct mtd_part_parser_data *data)
906 {
907 	struct mtd_part_parser *parser;
908 	int ret, err = 0;
909 
910 	if (!types)
911 		types = default_mtd_part_types;
912 
913 	for ( ; *types; types++) {
914 		pr_debug("%s: parsing partitions %s\n", master->name, *types);
915 		parser = mtd_part_parser_get(*types);
916 		if (!parser && !request_module("%s", *types))
917 			parser = mtd_part_parser_get(*types);
918 		pr_debug("%s: got parser %s\n", master->name,
919 			 parser ? parser->name : NULL);
920 		if (!parser)
921 			continue;
922 		ret = mtd_part_do_parse(parser, master, pparts, data);
923 		/* Found partitions! */
924 		if (ret > 0)
925 			return 0;
926 		mtd_part_parser_put(parser);
927 		/*
928 		 * Stash the first error we see; only report it if no parser
929 		 * succeeds
930 		 */
931 		if (ret < 0 && !err)
932 			err = ret;
933 	}
934 	return err;
935 }
936 
937 void mtd_part_parser_cleanup(struct mtd_partitions *parts)
938 {
939 	const struct mtd_part_parser *parser;
940 
941 	if (!parts)
942 		return;
943 
944 	parser = parts->parser;
945 	if (parser) {
946 		if (parser->cleanup)
947 			parser->cleanup(parts->parts, parts->nr_parts);
948 
949 		mtd_part_parser_put(parser);
950 	}
951 }
952 
953 int mtd_is_partition(const struct mtd_info *mtd)
954 {
955 	struct mtd_part *part;
956 	int ispart = 0;
957 
958 	mutex_lock(&mtd_partitions_mutex);
959 	list_for_each_entry(part, &mtd_partitions, list)
960 		if (&part->mtd == mtd) {
961 			ispart = 1;
962 			break;
963 		}
964 	mutex_unlock(&mtd_partitions_mutex);
965 
966 	return ispart;
967 }
968 EXPORT_SYMBOL_GPL(mtd_is_partition);
969 
970 /* Returns the size of the entire flash chip */
971 uint64_t mtd_get_device_size(const struct mtd_info *mtd)
972 {
973 	if (!mtd_is_partition(mtd))
974 		return mtd->size;
975 
976 	return mtd_get_device_size(mtd_to_part(mtd)->parent);
977 }
978 EXPORT_SYMBOL_GPL(mtd_get_device_size);
979