xref: /openbmc/linux/drivers/mtd/mtdpart.c (revision 7490ca1e)
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 /* Our partition node structure */
41 struct mtd_part {
42 	struct mtd_info mtd;
43 	struct mtd_info *master;
44 	uint64_t offset;
45 	struct list_head list;
46 };
47 
48 /*
49  * Given a pointer to the MTD object in the mtd_part structure, we can retrieve
50  * the pointer to that structure with this macro.
51  */
52 #define PART(x)  ((struct mtd_part *)(x))
53 
54 
55 /*
56  * MTD methods which simply translate the effective address and pass through
57  * to the _real_ device.
58  */
59 
60 static int part_read(struct mtd_info *mtd, loff_t from, size_t len,
61 		size_t *retlen, u_char *buf)
62 {
63 	struct mtd_part *part = PART(mtd);
64 	struct mtd_ecc_stats stats;
65 	int res;
66 
67 	stats = part->master->ecc_stats;
68 
69 	if (from >= mtd->size)
70 		len = 0;
71 	else if (from + len > mtd->size)
72 		len = mtd->size - from;
73 	res = mtd_read(part->master, from + part->offset, len, retlen, buf);
74 	if (unlikely(res)) {
75 		if (mtd_is_bitflip(res))
76 			mtd->ecc_stats.corrected += part->master->ecc_stats.corrected - stats.corrected;
77 		if (mtd_is_eccerr(res))
78 			mtd->ecc_stats.failed += part->master->ecc_stats.failed - stats.failed;
79 	}
80 	return res;
81 }
82 
83 static int part_point(struct mtd_info *mtd, loff_t from, size_t len,
84 		size_t *retlen, void **virt, resource_size_t *phys)
85 {
86 	struct mtd_part *part = PART(mtd);
87 	if (from >= mtd->size)
88 		len = 0;
89 	else if (from + len > mtd->size)
90 		len = mtd->size - from;
91 	return mtd_point(part->master, from + part->offset, len, retlen,
92 			 virt, phys);
93 }
94 
95 static void part_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
96 {
97 	struct mtd_part *part = PART(mtd);
98 
99 	mtd_unpoint(part->master, from + part->offset, len);
100 }
101 
102 static unsigned long part_get_unmapped_area(struct mtd_info *mtd,
103 					    unsigned long len,
104 					    unsigned long offset,
105 					    unsigned long flags)
106 {
107 	struct mtd_part *part = PART(mtd);
108 
109 	offset += part->offset;
110 	return mtd_get_unmapped_area(part->master, len, offset, flags);
111 }
112 
113 static int part_read_oob(struct mtd_info *mtd, loff_t from,
114 		struct mtd_oob_ops *ops)
115 {
116 	struct mtd_part *part = PART(mtd);
117 	int res;
118 
119 	if (from >= mtd->size)
120 		return -EINVAL;
121 	if (ops->datbuf && from + ops->len > mtd->size)
122 		return -EINVAL;
123 
124 	/*
125 	 * If OOB is also requested, make sure that we do not read past the end
126 	 * of this partition.
127 	 */
128 	if (ops->oobbuf) {
129 		size_t len, pages;
130 
131 		if (ops->mode == MTD_OPS_AUTO_OOB)
132 			len = mtd->oobavail;
133 		else
134 			len = mtd->oobsize;
135 		pages = mtd_div_by_ws(mtd->size, mtd);
136 		pages -= mtd_div_by_ws(from, mtd);
137 		if (ops->ooboffs + ops->ooblen > pages * len)
138 			return -EINVAL;
139 	}
140 
141 	res = mtd_read_oob(part->master, from + part->offset, ops);
142 	if (unlikely(res)) {
143 		if (mtd_is_bitflip(res))
144 			mtd->ecc_stats.corrected++;
145 		if (mtd_is_eccerr(res))
146 			mtd->ecc_stats.failed++;
147 	}
148 	return res;
149 }
150 
151 static int part_read_user_prot_reg(struct mtd_info *mtd, loff_t from,
152 		size_t len, size_t *retlen, u_char *buf)
153 {
154 	struct mtd_part *part = PART(mtd);
155 	return mtd_read_user_prot_reg(part->master, from, len, retlen, buf);
156 }
157 
158 static int part_get_user_prot_info(struct mtd_info *mtd,
159 		struct otp_info *buf, size_t len)
160 {
161 	struct mtd_part *part = PART(mtd);
162 	return mtd_get_user_prot_info(part->master, buf, len);
163 }
164 
165 static int part_read_fact_prot_reg(struct mtd_info *mtd, loff_t from,
166 		size_t len, size_t *retlen, u_char *buf)
167 {
168 	struct mtd_part *part = PART(mtd);
169 	return mtd_read_fact_prot_reg(part->master, from, len, retlen, buf);
170 }
171 
172 static int part_get_fact_prot_info(struct mtd_info *mtd, struct otp_info *buf,
173 		size_t len)
174 {
175 	struct mtd_part *part = PART(mtd);
176 	return mtd_get_fact_prot_info(part->master, buf, len);
177 }
178 
179 static int part_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 = PART(mtd);
183 	if (!(mtd->flags & MTD_WRITEABLE))
184 		return -EROFS;
185 	if (to >= mtd->size)
186 		len = 0;
187 	else if (to + len > mtd->size)
188 		len = mtd->size - to;
189 	return mtd_write(part->master, to + part->offset, len, retlen, buf);
190 }
191 
192 static int part_panic_write(struct mtd_info *mtd, loff_t to, size_t len,
193 		size_t *retlen, const u_char *buf)
194 {
195 	struct mtd_part *part = PART(mtd);
196 	if (!(mtd->flags & MTD_WRITEABLE))
197 		return -EROFS;
198 	if (to >= mtd->size)
199 		len = 0;
200 	else if (to + len > mtd->size)
201 		len = mtd->size - to;
202 	return mtd_panic_write(part->master, to + part->offset, len, retlen,
203 			       buf);
204 }
205 
206 static int part_write_oob(struct mtd_info *mtd, loff_t to,
207 		struct mtd_oob_ops *ops)
208 {
209 	struct mtd_part *part = PART(mtd);
210 
211 	if (!(mtd->flags & MTD_WRITEABLE))
212 		return -EROFS;
213 
214 	if (to >= mtd->size)
215 		return -EINVAL;
216 	if (ops->datbuf && to + ops->len > mtd->size)
217 		return -EINVAL;
218 	return mtd_write_oob(part->master, to + part->offset, ops);
219 }
220 
221 static int part_write_user_prot_reg(struct mtd_info *mtd, loff_t from,
222 		size_t len, size_t *retlen, u_char *buf)
223 {
224 	struct mtd_part *part = PART(mtd);
225 	return mtd_write_user_prot_reg(part->master, from, len, retlen, buf);
226 }
227 
228 static int part_lock_user_prot_reg(struct mtd_info *mtd, loff_t from,
229 		size_t len)
230 {
231 	struct mtd_part *part = PART(mtd);
232 	return mtd_lock_user_prot_reg(part->master, from, len);
233 }
234 
235 static int part_writev(struct mtd_info *mtd, const struct kvec *vecs,
236 		unsigned long count, loff_t to, size_t *retlen)
237 {
238 	struct mtd_part *part = PART(mtd);
239 	if (!(mtd->flags & MTD_WRITEABLE))
240 		return -EROFS;
241 	return mtd_writev(part->master, vecs, count, to + part->offset,
242 			  retlen);
243 }
244 
245 static int part_erase(struct mtd_info *mtd, struct erase_info *instr)
246 {
247 	struct mtd_part *part = PART(mtd);
248 	int ret;
249 	if (!(mtd->flags & MTD_WRITEABLE))
250 		return -EROFS;
251 	if (instr->addr >= mtd->size)
252 		return -EINVAL;
253 	instr->addr += part->offset;
254 	ret = mtd_erase(part->master, instr);
255 	if (ret) {
256 		if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
257 			instr->fail_addr -= part->offset;
258 		instr->addr -= part->offset;
259 	}
260 	return ret;
261 }
262 
263 void mtd_erase_callback(struct erase_info *instr)
264 {
265 	if (instr->mtd->erase == part_erase) {
266 		struct mtd_part *part = PART(instr->mtd);
267 
268 		if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
269 			instr->fail_addr -= part->offset;
270 		instr->addr -= part->offset;
271 	}
272 	if (instr->callback)
273 		instr->callback(instr);
274 }
275 EXPORT_SYMBOL_GPL(mtd_erase_callback);
276 
277 static int part_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
278 {
279 	struct mtd_part *part = PART(mtd);
280 	if ((len + ofs) > mtd->size)
281 		return -EINVAL;
282 	return mtd_lock(part->master, ofs + part->offset, len);
283 }
284 
285 static int part_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
286 {
287 	struct mtd_part *part = PART(mtd);
288 	if ((len + ofs) > mtd->size)
289 		return -EINVAL;
290 	return mtd_unlock(part->master, ofs + part->offset, len);
291 }
292 
293 static int part_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
294 {
295 	struct mtd_part *part = PART(mtd);
296 	if ((len + ofs) > mtd->size)
297 		return -EINVAL;
298 	return mtd_is_locked(part->master, ofs + part->offset, len);
299 }
300 
301 static void part_sync(struct mtd_info *mtd)
302 {
303 	struct mtd_part *part = PART(mtd);
304 	mtd_sync(part->master);
305 }
306 
307 static int part_suspend(struct mtd_info *mtd)
308 {
309 	struct mtd_part *part = PART(mtd);
310 	return mtd_suspend(part->master);
311 }
312 
313 static void part_resume(struct mtd_info *mtd)
314 {
315 	struct mtd_part *part = PART(mtd);
316 	mtd_resume(part->master);
317 }
318 
319 static int part_block_isbad(struct mtd_info *mtd, loff_t ofs)
320 {
321 	struct mtd_part *part = PART(mtd);
322 	if (ofs >= mtd->size)
323 		return -EINVAL;
324 	ofs += part->offset;
325 	return mtd_block_isbad(part->master, ofs);
326 }
327 
328 static int part_block_markbad(struct mtd_info *mtd, loff_t ofs)
329 {
330 	struct mtd_part *part = PART(mtd);
331 	int res;
332 
333 	if (!(mtd->flags & MTD_WRITEABLE))
334 		return -EROFS;
335 	if (ofs >= mtd->size)
336 		return -EINVAL;
337 	ofs += part->offset;
338 	res = mtd_block_markbad(part->master, ofs);
339 	if (!res)
340 		mtd->ecc_stats.badblocks++;
341 	return res;
342 }
343 
344 static inline void free_partition(struct mtd_part *p)
345 {
346 	kfree(p->mtd.name);
347 	kfree(p);
348 }
349 
350 /*
351  * This function unregisters and destroy all slave MTD objects which are
352  * attached to the given master MTD object.
353  */
354 
355 int del_mtd_partitions(struct mtd_info *master)
356 {
357 	struct mtd_part *slave, *next;
358 	int ret, err = 0;
359 
360 	mutex_lock(&mtd_partitions_mutex);
361 	list_for_each_entry_safe(slave, next, &mtd_partitions, list)
362 		if (slave->master == master) {
363 			ret = del_mtd_device(&slave->mtd);
364 			if (ret < 0) {
365 				err = ret;
366 				continue;
367 			}
368 			list_del(&slave->list);
369 			free_partition(slave);
370 		}
371 	mutex_unlock(&mtd_partitions_mutex);
372 
373 	return err;
374 }
375 
376 static struct mtd_part *allocate_partition(struct mtd_info *master,
377 			const struct mtd_partition *part, int partno,
378 			uint64_t cur_offset)
379 {
380 	struct mtd_part *slave;
381 	char *name;
382 
383 	/* allocate the partition structure */
384 	slave = kzalloc(sizeof(*slave), GFP_KERNEL);
385 	name = kstrdup(part->name, GFP_KERNEL);
386 	if (!name || !slave) {
387 		printk(KERN_ERR"memory allocation error while creating partitions for \"%s\"\n",
388 		       master->name);
389 		kfree(name);
390 		kfree(slave);
391 		return ERR_PTR(-ENOMEM);
392 	}
393 
394 	/* set up the MTD object for this partition */
395 	slave->mtd.type = master->type;
396 	slave->mtd.flags = master->flags & ~part->mask_flags;
397 	slave->mtd.size = part->size;
398 	slave->mtd.writesize = master->writesize;
399 	slave->mtd.writebufsize = master->writebufsize;
400 	slave->mtd.oobsize = master->oobsize;
401 	slave->mtd.oobavail = master->oobavail;
402 	slave->mtd.subpage_sft = master->subpage_sft;
403 
404 	slave->mtd.name = name;
405 	slave->mtd.owner = master->owner;
406 	slave->mtd.backing_dev_info = master->backing_dev_info;
407 
408 	/* NOTE:  we don't arrange MTDs as a tree; it'd be error-prone
409 	 * to have the same data be in two different partitions.
410 	 */
411 	slave->mtd.dev.parent = master->dev.parent;
412 
413 	slave->mtd.read = part_read;
414 	slave->mtd.write = part_write;
415 
416 	if (master->panic_write)
417 		slave->mtd.panic_write = part_panic_write;
418 
419 	if (master->point && master->unpoint) {
420 		slave->mtd.point = part_point;
421 		slave->mtd.unpoint = part_unpoint;
422 	}
423 
424 	if (master->get_unmapped_area)
425 		slave->mtd.get_unmapped_area = part_get_unmapped_area;
426 	if (master->read_oob)
427 		slave->mtd.read_oob = part_read_oob;
428 	if (master->write_oob)
429 		slave->mtd.write_oob = part_write_oob;
430 	if (master->read_user_prot_reg)
431 		slave->mtd.read_user_prot_reg = part_read_user_prot_reg;
432 	if (master->read_fact_prot_reg)
433 		slave->mtd.read_fact_prot_reg = part_read_fact_prot_reg;
434 	if (master->write_user_prot_reg)
435 		slave->mtd.write_user_prot_reg = part_write_user_prot_reg;
436 	if (master->lock_user_prot_reg)
437 		slave->mtd.lock_user_prot_reg = part_lock_user_prot_reg;
438 	if (master->get_user_prot_info)
439 		slave->mtd.get_user_prot_info = part_get_user_prot_info;
440 	if (master->get_fact_prot_info)
441 		slave->mtd.get_fact_prot_info = part_get_fact_prot_info;
442 	if (master->sync)
443 		slave->mtd.sync = part_sync;
444 	if (!partno && !master->dev.class && master->suspend && master->resume) {
445 			slave->mtd.suspend = part_suspend;
446 			slave->mtd.resume = part_resume;
447 	}
448 	if (master->writev)
449 		slave->mtd.writev = part_writev;
450 	if (master->lock)
451 		slave->mtd.lock = part_lock;
452 	if (master->unlock)
453 		slave->mtd.unlock = part_unlock;
454 	if (master->is_locked)
455 		slave->mtd.is_locked = part_is_locked;
456 	if (master->block_isbad)
457 		slave->mtd.block_isbad = part_block_isbad;
458 	if (master->block_markbad)
459 		slave->mtd.block_markbad = part_block_markbad;
460 	slave->mtd.erase = part_erase;
461 	slave->master = master;
462 	slave->offset = part->offset;
463 
464 	if (slave->offset == MTDPART_OFS_APPEND)
465 		slave->offset = cur_offset;
466 	if (slave->offset == MTDPART_OFS_NXTBLK) {
467 		slave->offset = cur_offset;
468 		if (mtd_mod_by_eb(cur_offset, master) != 0) {
469 			/* Round up to next erasesize */
470 			slave->offset = (mtd_div_by_eb(cur_offset, master) + 1) * master->erasesize;
471 			printk(KERN_NOTICE "Moving partition %d: "
472 			       "0x%012llx -> 0x%012llx\n", partno,
473 			       (unsigned long long)cur_offset, (unsigned long long)slave->offset);
474 		}
475 	}
476 	if (slave->offset == MTDPART_OFS_RETAIN) {
477 		slave->offset = cur_offset;
478 		if (master->size - slave->offset >= slave->mtd.size) {
479 			slave->mtd.size = master->size - slave->offset
480 							- slave->mtd.size;
481 		} else {
482 			printk(KERN_ERR "mtd partition \"%s\" doesn't have enough space: %#llx < %#llx, disabled\n",
483 				part->name, master->size - slave->offset,
484 				slave->mtd.size);
485 			/* register to preserve ordering */
486 			goto out_register;
487 		}
488 	}
489 	if (slave->mtd.size == MTDPART_SIZ_FULL)
490 		slave->mtd.size = master->size - slave->offset;
491 
492 	printk(KERN_NOTICE "0x%012llx-0x%012llx : \"%s\"\n", (unsigned long long)slave->offset,
493 		(unsigned long long)(slave->offset + slave->mtd.size), slave->mtd.name);
494 
495 	/* let's do some sanity checks */
496 	if (slave->offset >= master->size) {
497 		/* let's register it anyway to preserve ordering */
498 		slave->offset = 0;
499 		slave->mtd.size = 0;
500 		printk(KERN_ERR"mtd: partition \"%s\" is out of reach -- disabled\n",
501 			part->name);
502 		goto out_register;
503 	}
504 	if (slave->offset + slave->mtd.size > master->size) {
505 		slave->mtd.size = master->size - slave->offset;
506 		printk(KERN_WARNING"mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#llx\n",
507 			part->name, master->name, (unsigned long long)slave->mtd.size);
508 	}
509 	if (master->numeraseregions > 1) {
510 		/* Deal with variable erase size stuff */
511 		int i, max = master->numeraseregions;
512 		u64 end = slave->offset + slave->mtd.size;
513 		struct mtd_erase_region_info *regions = master->eraseregions;
514 
515 		/* Find the first erase regions which is part of this
516 		 * partition. */
517 		for (i = 0; i < max && regions[i].offset <= slave->offset; i++)
518 			;
519 		/* The loop searched for the region _behind_ the first one */
520 		if (i > 0)
521 			i--;
522 
523 		/* Pick biggest erasesize */
524 		for (; i < max && regions[i].offset < end; i++) {
525 			if (slave->mtd.erasesize < regions[i].erasesize) {
526 				slave->mtd.erasesize = regions[i].erasesize;
527 			}
528 		}
529 		BUG_ON(slave->mtd.erasesize == 0);
530 	} else {
531 		/* Single erase size */
532 		slave->mtd.erasesize = master->erasesize;
533 	}
534 
535 	if ((slave->mtd.flags & MTD_WRITEABLE) &&
536 	    mtd_mod_by_eb(slave->offset, &slave->mtd)) {
537 		/* Doesn't start on a boundary of major erase size */
538 		/* FIXME: Let it be writable if it is on a boundary of
539 		 * _minor_ erase size though */
540 		slave->mtd.flags &= ~MTD_WRITEABLE;
541 		printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",
542 			part->name);
543 	}
544 	if ((slave->mtd.flags & MTD_WRITEABLE) &&
545 	    mtd_mod_by_eb(slave->mtd.size, &slave->mtd)) {
546 		slave->mtd.flags &= ~MTD_WRITEABLE;
547 		printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
548 			part->name);
549 	}
550 
551 	slave->mtd.ecclayout = master->ecclayout;
552 	if (master->block_isbad) {
553 		uint64_t offs = 0;
554 
555 		while (offs < slave->mtd.size) {
556 			if (mtd_block_isbad(master, offs + slave->offset))
557 				slave->mtd.ecc_stats.badblocks++;
558 			offs += slave->mtd.erasesize;
559 		}
560 	}
561 
562 out_register:
563 	return slave;
564 }
565 
566 int mtd_add_partition(struct mtd_info *master, char *name,
567 		      long long offset, long long length)
568 {
569 	struct mtd_partition part;
570 	struct mtd_part *p, *new;
571 	uint64_t start, end;
572 	int ret = 0;
573 
574 	/* the direct offset is expected */
575 	if (offset == MTDPART_OFS_APPEND ||
576 	    offset == MTDPART_OFS_NXTBLK)
577 		return -EINVAL;
578 
579 	if (length == MTDPART_SIZ_FULL)
580 		length = master->size - offset;
581 
582 	if (length <= 0)
583 		return -EINVAL;
584 
585 	part.name = name;
586 	part.size = length;
587 	part.offset = offset;
588 	part.mask_flags = 0;
589 	part.ecclayout = NULL;
590 
591 	new = allocate_partition(master, &part, -1, offset);
592 	if (IS_ERR(new))
593 		return PTR_ERR(new);
594 
595 	start = offset;
596 	end = offset + length;
597 
598 	mutex_lock(&mtd_partitions_mutex);
599 	list_for_each_entry(p, &mtd_partitions, list)
600 		if (p->master == master) {
601 			if ((start >= p->offset) &&
602 			    (start < (p->offset + p->mtd.size)))
603 				goto err_inv;
604 
605 			if ((end >= p->offset) &&
606 			    (end < (p->offset + p->mtd.size)))
607 				goto err_inv;
608 		}
609 
610 	list_add(&new->list, &mtd_partitions);
611 	mutex_unlock(&mtd_partitions_mutex);
612 
613 	add_mtd_device(&new->mtd);
614 
615 	return ret;
616 err_inv:
617 	mutex_unlock(&mtd_partitions_mutex);
618 	free_partition(new);
619 	return -EINVAL;
620 }
621 EXPORT_SYMBOL_GPL(mtd_add_partition);
622 
623 int mtd_del_partition(struct mtd_info *master, int partno)
624 {
625 	struct mtd_part *slave, *next;
626 	int ret = -EINVAL;
627 
628 	mutex_lock(&mtd_partitions_mutex);
629 	list_for_each_entry_safe(slave, next, &mtd_partitions, list)
630 		if ((slave->master == master) &&
631 		    (slave->mtd.index == partno)) {
632 			ret = del_mtd_device(&slave->mtd);
633 			if (ret < 0)
634 				break;
635 
636 			list_del(&slave->list);
637 			free_partition(slave);
638 			break;
639 		}
640 	mutex_unlock(&mtd_partitions_mutex);
641 
642 	return ret;
643 }
644 EXPORT_SYMBOL_GPL(mtd_del_partition);
645 
646 /*
647  * This function, given a master MTD object and a partition table, creates
648  * and registers slave MTD objects which are bound to the master according to
649  * the partition definitions.
650  *
651  * We don't register the master, or expect the caller to have done so,
652  * for reasons of data integrity.
653  */
654 
655 int add_mtd_partitions(struct mtd_info *master,
656 		       const struct mtd_partition *parts,
657 		       int nbparts)
658 {
659 	struct mtd_part *slave;
660 	uint64_t cur_offset = 0;
661 	int i;
662 
663 	printk(KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);
664 
665 	for (i = 0; i < nbparts; i++) {
666 		slave = allocate_partition(master, parts + i, i, cur_offset);
667 		if (IS_ERR(slave))
668 			return PTR_ERR(slave);
669 
670 		mutex_lock(&mtd_partitions_mutex);
671 		list_add(&slave->list, &mtd_partitions);
672 		mutex_unlock(&mtd_partitions_mutex);
673 
674 		add_mtd_device(&slave->mtd);
675 
676 		cur_offset = slave->offset + slave->mtd.size;
677 	}
678 
679 	return 0;
680 }
681 
682 static DEFINE_SPINLOCK(part_parser_lock);
683 static LIST_HEAD(part_parsers);
684 
685 static struct mtd_part_parser *get_partition_parser(const char *name)
686 {
687 	struct mtd_part_parser *p, *ret = NULL;
688 
689 	spin_lock(&part_parser_lock);
690 
691 	list_for_each_entry(p, &part_parsers, list)
692 		if (!strcmp(p->name, name) && try_module_get(p->owner)) {
693 			ret = p;
694 			break;
695 		}
696 
697 	spin_unlock(&part_parser_lock);
698 
699 	return ret;
700 }
701 
702 #define put_partition_parser(p) do { module_put((p)->owner); } while (0)
703 
704 int register_mtd_parser(struct mtd_part_parser *p)
705 {
706 	spin_lock(&part_parser_lock);
707 	list_add(&p->list, &part_parsers);
708 	spin_unlock(&part_parser_lock);
709 
710 	return 0;
711 }
712 EXPORT_SYMBOL_GPL(register_mtd_parser);
713 
714 int deregister_mtd_parser(struct mtd_part_parser *p)
715 {
716 	spin_lock(&part_parser_lock);
717 	list_del(&p->list);
718 	spin_unlock(&part_parser_lock);
719 	return 0;
720 }
721 EXPORT_SYMBOL_GPL(deregister_mtd_parser);
722 
723 /*
724  * Do not forget to update 'parse_mtd_partitions()' kerneldoc comment if you
725  * are changing this array!
726  */
727 static const char *default_mtd_part_types[] = {
728 	"cmdlinepart",
729 	"ofpart",
730 	NULL
731 };
732 
733 /**
734  * parse_mtd_partitions - parse MTD partitions
735  * @master: the master partition (describes whole MTD device)
736  * @types: names of partition parsers to try or %NULL
737  * @pparts: array of partitions found is returned here
738  * @data: MTD partition parser-specific data
739  *
740  * This function tries to find partition on MTD device @master. It uses MTD
741  * partition parsers, specified in @types. However, if @types is %NULL, then
742  * the default list of parsers is used. The default list contains only the
743  * "cmdlinepart" and "ofpart" parsers ATM.
744  *
745  * This function may return:
746  * o a negative error code in case of failure
747  * o zero if no partitions were found
748  * o a positive number of found partitions, in which case on exit @pparts will
749  *   point to an array containing this number of &struct mtd_info objects.
750  */
751 int parse_mtd_partitions(struct mtd_info *master, const char **types,
752 			 struct mtd_partition **pparts,
753 			 struct mtd_part_parser_data *data)
754 {
755 	struct mtd_part_parser *parser;
756 	int ret = 0;
757 
758 	if (!types)
759 		types = default_mtd_part_types;
760 
761 	for ( ; ret <= 0 && *types; types++) {
762 		parser = get_partition_parser(*types);
763 		if (!parser && !request_module("%s", *types))
764 				parser = get_partition_parser(*types);
765 		if (!parser)
766 			continue;
767 		ret = (*parser->parse_fn)(master, pparts, data);
768 		if (ret > 0) {
769 			printk(KERN_NOTICE "%d %s partitions found on MTD device %s\n",
770 			       ret, parser->name, master->name);
771 		}
772 		put_partition_parser(parser);
773 	}
774 	return ret;
775 }
776 
777 int mtd_is_partition(struct mtd_info *mtd)
778 {
779 	struct mtd_part *part;
780 	int ispart = 0;
781 
782 	mutex_lock(&mtd_partitions_mutex);
783 	list_for_each_entry(part, &mtd_partitions, list)
784 		if (&part->mtd == mtd) {
785 			ispart = 1;
786 			break;
787 		}
788 	mutex_unlock(&mtd_partitions_mutex);
789 
790 	return ispart;
791 }
792 EXPORT_SYMBOL_GPL(mtd_is_partition);
793