xref: /openbmc/linux/drivers/mtd/mtdpart.c (revision 81d67439)
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 = part->master->read(part->master, from + part->offset,
74 				   len, retlen, buf);
75 	if (unlikely(res)) {
76 		if (res == -EUCLEAN)
77 			mtd->ecc_stats.corrected += part->master->ecc_stats.corrected - stats.corrected;
78 		if (res == -EBADMSG)
79 			mtd->ecc_stats.failed += part->master->ecc_stats.failed - stats.failed;
80 	}
81 	return res;
82 }
83 
84 static int part_point(struct mtd_info *mtd, loff_t from, size_t len,
85 		size_t *retlen, void **virt, resource_size_t *phys)
86 {
87 	struct mtd_part *part = PART(mtd);
88 	if (from >= mtd->size)
89 		len = 0;
90 	else if (from + len > mtd->size)
91 		len = mtd->size - from;
92 	return part->master->point (part->master, from + part->offset,
93 				    len, retlen, virt, phys);
94 }
95 
96 static void part_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
97 {
98 	struct mtd_part *part = PART(mtd);
99 
100 	part->master->unpoint(part->master, from + part->offset, len);
101 }
102 
103 static unsigned long part_get_unmapped_area(struct mtd_info *mtd,
104 					    unsigned long len,
105 					    unsigned long offset,
106 					    unsigned long flags)
107 {
108 	struct mtd_part *part = PART(mtd);
109 
110 	offset += part->offset;
111 	return part->master->get_unmapped_area(part->master, len, offset,
112 					       flags);
113 }
114 
115 static int part_read_oob(struct mtd_info *mtd, loff_t from,
116 		struct mtd_oob_ops *ops)
117 {
118 	struct mtd_part *part = PART(mtd);
119 	int res;
120 
121 	if (from >= mtd->size)
122 		return -EINVAL;
123 	if (ops->datbuf && from + ops->len > mtd->size)
124 		return -EINVAL;
125 
126 	/*
127 	 * If OOB is also requested, make sure that we do not read past the end
128 	 * of this partition.
129 	 */
130 	if (ops->oobbuf) {
131 		size_t len, pages;
132 
133 		if (ops->mode == MTD_OOB_AUTO)
134 			len = mtd->oobavail;
135 		else
136 			len = mtd->oobsize;
137 		pages = mtd_div_by_ws(mtd->size, mtd);
138 		pages -= mtd_div_by_ws(from, mtd);
139 		if (ops->ooboffs + ops->ooblen > pages * len)
140 			return -EINVAL;
141 	}
142 
143 	res = part->master->read_oob(part->master, from + part->offset, ops);
144 	if (unlikely(res)) {
145 		if (res == -EUCLEAN)
146 			mtd->ecc_stats.corrected++;
147 		if (res == -EBADMSG)
148 			mtd->ecc_stats.failed++;
149 	}
150 	return res;
151 }
152 
153 static int part_read_user_prot_reg(struct mtd_info *mtd, loff_t from,
154 		size_t len, size_t *retlen, u_char *buf)
155 {
156 	struct mtd_part *part = PART(mtd);
157 	return part->master->read_user_prot_reg(part->master, from,
158 					len, retlen, buf);
159 }
160 
161 static int part_get_user_prot_info(struct mtd_info *mtd,
162 		struct otp_info *buf, size_t len)
163 {
164 	struct mtd_part *part = PART(mtd);
165 	return part->master->get_user_prot_info(part->master, buf, len);
166 }
167 
168 static int part_read_fact_prot_reg(struct mtd_info *mtd, loff_t from,
169 		size_t len, size_t *retlen, u_char *buf)
170 {
171 	struct mtd_part *part = PART(mtd);
172 	return part->master->read_fact_prot_reg(part->master, from,
173 					len, retlen, buf);
174 }
175 
176 static int part_get_fact_prot_info(struct mtd_info *mtd, struct otp_info *buf,
177 		size_t len)
178 {
179 	struct mtd_part *part = PART(mtd);
180 	return part->master->get_fact_prot_info(part->master, buf, len);
181 }
182 
183 static int part_write(struct mtd_info *mtd, loff_t to, size_t len,
184 		size_t *retlen, const u_char *buf)
185 {
186 	struct mtd_part *part = PART(mtd);
187 	if (!(mtd->flags & MTD_WRITEABLE))
188 		return -EROFS;
189 	if (to >= mtd->size)
190 		len = 0;
191 	else if (to + len > mtd->size)
192 		len = mtd->size - to;
193 	return part->master->write(part->master, to + part->offset,
194 				    len, retlen, buf);
195 }
196 
197 static int part_panic_write(struct mtd_info *mtd, loff_t to, size_t len,
198 		size_t *retlen, const u_char *buf)
199 {
200 	struct mtd_part *part = PART(mtd);
201 	if (!(mtd->flags & MTD_WRITEABLE))
202 		return -EROFS;
203 	if (to >= mtd->size)
204 		len = 0;
205 	else if (to + len > mtd->size)
206 		len = mtd->size - to;
207 	return part->master->panic_write(part->master, to + part->offset,
208 				    len, retlen, buf);
209 }
210 
211 static int part_write_oob(struct mtd_info *mtd, loff_t to,
212 		struct mtd_oob_ops *ops)
213 {
214 	struct mtd_part *part = PART(mtd);
215 
216 	if (!(mtd->flags & MTD_WRITEABLE))
217 		return -EROFS;
218 
219 	if (to >= mtd->size)
220 		return -EINVAL;
221 	if (ops->datbuf && to + ops->len > mtd->size)
222 		return -EINVAL;
223 	return part->master->write_oob(part->master, to + part->offset, ops);
224 }
225 
226 static int part_write_user_prot_reg(struct mtd_info *mtd, loff_t from,
227 		size_t len, size_t *retlen, u_char *buf)
228 {
229 	struct mtd_part *part = PART(mtd);
230 	return part->master->write_user_prot_reg(part->master, from,
231 					len, retlen, buf);
232 }
233 
234 static int part_lock_user_prot_reg(struct mtd_info *mtd, loff_t from,
235 		size_t len)
236 {
237 	struct mtd_part *part = PART(mtd);
238 	return part->master->lock_user_prot_reg(part->master, from, len);
239 }
240 
241 static int part_writev(struct mtd_info *mtd, const struct kvec *vecs,
242 		unsigned long count, loff_t to, size_t *retlen)
243 {
244 	struct mtd_part *part = PART(mtd);
245 	if (!(mtd->flags & MTD_WRITEABLE))
246 		return -EROFS;
247 	return part->master->writev(part->master, vecs, count,
248 					to + part->offset, retlen);
249 }
250 
251 static int part_erase(struct mtd_info *mtd, struct erase_info *instr)
252 {
253 	struct mtd_part *part = PART(mtd);
254 	int ret;
255 	if (!(mtd->flags & MTD_WRITEABLE))
256 		return -EROFS;
257 	if (instr->addr >= mtd->size)
258 		return -EINVAL;
259 	instr->addr += part->offset;
260 	ret = part->master->erase(part->master, instr);
261 	if (ret) {
262 		if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
263 			instr->fail_addr -= part->offset;
264 		instr->addr -= part->offset;
265 	}
266 	return ret;
267 }
268 
269 void mtd_erase_callback(struct erase_info *instr)
270 {
271 	if (instr->mtd->erase == part_erase) {
272 		struct mtd_part *part = PART(instr->mtd);
273 
274 		if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
275 			instr->fail_addr -= part->offset;
276 		instr->addr -= part->offset;
277 	}
278 	if (instr->callback)
279 		instr->callback(instr);
280 }
281 EXPORT_SYMBOL_GPL(mtd_erase_callback);
282 
283 static int part_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
284 {
285 	struct mtd_part *part = PART(mtd);
286 	if ((len + ofs) > mtd->size)
287 		return -EINVAL;
288 	return part->master->lock(part->master, ofs + part->offset, len);
289 }
290 
291 static int part_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
292 {
293 	struct mtd_part *part = PART(mtd);
294 	if ((len + ofs) > mtd->size)
295 		return -EINVAL;
296 	return part->master->unlock(part->master, ofs + part->offset, len);
297 }
298 
299 static int part_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
300 {
301 	struct mtd_part *part = PART(mtd);
302 	if ((len + ofs) > mtd->size)
303 		return -EINVAL;
304 	return part->master->is_locked(part->master, ofs + part->offset, len);
305 }
306 
307 static void part_sync(struct mtd_info *mtd)
308 {
309 	struct mtd_part *part = PART(mtd);
310 	part->master->sync(part->master);
311 }
312 
313 static int part_suspend(struct mtd_info *mtd)
314 {
315 	struct mtd_part *part = PART(mtd);
316 	return part->master->suspend(part->master);
317 }
318 
319 static void part_resume(struct mtd_info *mtd)
320 {
321 	struct mtd_part *part = PART(mtd);
322 	part->master->resume(part->master);
323 }
324 
325 static int part_block_isbad(struct mtd_info *mtd, loff_t ofs)
326 {
327 	struct mtd_part *part = PART(mtd);
328 	if (ofs >= mtd->size)
329 		return -EINVAL;
330 	ofs += part->offset;
331 	return part->master->block_isbad(part->master, ofs);
332 }
333 
334 static int part_block_markbad(struct mtd_info *mtd, loff_t ofs)
335 {
336 	struct mtd_part *part = PART(mtd);
337 	int res;
338 
339 	if (!(mtd->flags & MTD_WRITEABLE))
340 		return -EROFS;
341 	if (ofs >= mtd->size)
342 		return -EINVAL;
343 	ofs += part->offset;
344 	res = part->master->block_markbad(part->master, ofs);
345 	if (!res)
346 		mtd->ecc_stats.badblocks++;
347 	return res;
348 }
349 
350 static inline void free_partition(struct mtd_part *p)
351 {
352 	kfree(p->mtd.name);
353 	kfree(p);
354 }
355 
356 /*
357  * This function unregisters and destroy all slave MTD objects which are
358  * attached to the given master MTD object.
359  */
360 
361 int del_mtd_partitions(struct mtd_info *master)
362 {
363 	struct mtd_part *slave, *next;
364 	int ret, err = 0;
365 
366 	mutex_lock(&mtd_partitions_mutex);
367 	list_for_each_entry_safe(slave, next, &mtd_partitions, list)
368 		if (slave->master == master) {
369 			ret = del_mtd_device(&slave->mtd);
370 			if (ret < 0) {
371 				err = ret;
372 				continue;
373 			}
374 			list_del(&slave->list);
375 			free_partition(slave);
376 		}
377 	mutex_unlock(&mtd_partitions_mutex);
378 
379 	return err;
380 }
381 
382 static struct mtd_part *allocate_partition(struct mtd_info *master,
383 			const struct mtd_partition *part, int partno,
384 			uint64_t cur_offset)
385 {
386 	struct mtd_part *slave;
387 	char *name;
388 
389 	/* allocate the partition structure */
390 	slave = kzalloc(sizeof(*slave), GFP_KERNEL);
391 	name = kstrdup(part->name, GFP_KERNEL);
392 	if (!name || !slave) {
393 		printk(KERN_ERR"memory allocation error while creating partitions for \"%s\"\n",
394 		       master->name);
395 		kfree(name);
396 		kfree(slave);
397 		return ERR_PTR(-ENOMEM);
398 	}
399 
400 	/* set up the MTD object for this partition */
401 	slave->mtd.type = master->type;
402 	slave->mtd.flags = master->flags & ~part->mask_flags;
403 	slave->mtd.size = part->size;
404 	slave->mtd.writesize = master->writesize;
405 	slave->mtd.writebufsize = master->writebufsize;
406 	slave->mtd.oobsize = master->oobsize;
407 	slave->mtd.oobavail = master->oobavail;
408 	slave->mtd.subpage_sft = master->subpage_sft;
409 
410 	slave->mtd.name = name;
411 	slave->mtd.owner = master->owner;
412 	slave->mtd.backing_dev_info = master->backing_dev_info;
413 
414 	/* NOTE:  we don't arrange MTDs as a tree; it'd be error-prone
415 	 * to have the same data be in two different partitions.
416 	 */
417 	slave->mtd.dev.parent = master->dev.parent;
418 
419 	slave->mtd.read = part_read;
420 	slave->mtd.write = part_write;
421 
422 	if (master->panic_write)
423 		slave->mtd.panic_write = part_panic_write;
424 
425 	if (master->point && master->unpoint) {
426 		slave->mtd.point = part_point;
427 		slave->mtd.unpoint = part_unpoint;
428 	}
429 
430 	if (master->get_unmapped_area)
431 		slave->mtd.get_unmapped_area = part_get_unmapped_area;
432 	if (master->read_oob)
433 		slave->mtd.read_oob = part_read_oob;
434 	if (master->write_oob)
435 		slave->mtd.write_oob = part_write_oob;
436 	if (master->read_user_prot_reg)
437 		slave->mtd.read_user_prot_reg = part_read_user_prot_reg;
438 	if (master->read_fact_prot_reg)
439 		slave->mtd.read_fact_prot_reg = part_read_fact_prot_reg;
440 	if (master->write_user_prot_reg)
441 		slave->mtd.write_user_prot_reg = part_write_user_prot_reg;
442 	if (master->lock_user_prot_reg)
443 		slave->mtd.lock_user_prot_reg = part_lock_user_prot_reg;
444 	if (master->get_user_prot_info)
445 		slave->mtd.get_user_prot_info = part_get_user_prot_info;
446 	if (master->get_fact_prot_info)
447 		slave->mtd.get_fact_prot_info = part_get_fact_prot_info;
448 	if (master->sync)
449 		slave->mtd.sync = part_sync;
450 	if (!partno && !master->dev.class && master->suspend && master->resume) {
451 			slave->mtd.suspend = part_suspend;
452 			slave->mtd.resume = part_resume;
453 	}
454 	if (master->writev)
455 		slave->mtd.writev = part_writev;
456 	if (master->lock)
457 		slave->mtd.lock = part_lock;
458 	if (master->unlock)
459 		slave->mtd.unlock = part_unlock;
460 	if (master->is_locked)
461 		slave->mtd.is_locked = part_is_locked;
462 	if (master->block_isbad)
463 		slave->mtd.block_isbad = part_block_isbad;
464 	if (master->block_markbad)
465 		slave->mtd.block_markbad = part_block_markbad;
466 	slave->mtd.erase = part_erase;
467 	slave->master = master;
468 	slave->offset = part->offset;
469 
470 	if (slave->offset == MTDPART_OFS_APPEND)
471 		slave->offset = cur_offset;
472 	if (slave->offset == MTDPART_OFS_NXTBLK) {
473 		slave->offset = cur_offset;
474 		if (mtd_mod_by_eb(cur_offset, master) != 0) {
475 			/* Round up to next erasesize */
476 			slave->offset = (mtd_div_by_eb(cur_offset, master) + 1) * master->erasesize;
477 			printk(KERN_NOTICE "Moving partition %d: "
478 			       "0x%012llx -> 0x%012llx\n", partno,
479 			       (unsigned long long)cur_offset, (unsigned long long)slave->offset);
480 		}
481 	}
482 	if (slave->mtd.size == MTDPART_SIZ_FULL)
483 		slave->mtd.size = master->size - slave->offset;
484 
485 	printk(KERN_NOTICE "0x%012llx-0x%012llx : \"%s\"\n", (unsigned long long)slave->offset,
486 		(unsigned long long)(slave->offset + slave->mtd.size), slave->mtd.name);
487 
488 	/* let's do some sanity checks */
489 	if (slave->offset >= master->size) {
490 		/* let's register it anyway to preserve ordering */
491 		slave->offset = 0;
492 		slave->mtd.size = 0;
493 		printk(KERN_ERR"mtd: partition \"%s\" is out of reach -- disabled\n",
494 			part->name);
495 		goto out_register;
496 	}
497 	if (slave->offset + slave->mtd.size > master->size) {
498 		slave->mtd.size = master->size - slave->offset;
499 		printk(KERN_WARNING"mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#llx\n",
500 			part->name, master->name, (unsigned long long)slave->mtd.size);
501 	}
502 	if (master->numeraseregions > 1) {
503 		/* Deal with variable erase size stuff */
504 		int i, max = master->numeraseregions;
505 		u64 end = slave->offset + slave->mtd.size;
506 		struct mtd_erase_region_info *regions = master->eraseregions;
507 
508 		/* Find the first erase regions which is part of this
509 		 * partition. */
510 		for (i = 0; i < max && regions[i].offset <= slave->offset; i++)
511 			;
512 		/* The loop searched for the region _behind_ the first one */
513 		if (i > 0)
514 			i--;
515 
516 		/* Pick biggest erasesize */
517 		for (; i < max && regions[i].offset < end; i++) {
518 			if (slave->mtd.erasesize < regions[i].erasesize) {
519 				slave->mtd.erasesize = regions[i].erasesize;
520 			}
521 		}
522 		BUG_ON(slave->mtd.erasesize == 0);
523 	} else {
524 		/* Single erase size */
525 		slave->mtd.erasesize = master->erasesize;
526 	}
527 
528 	if ((slave->mtd.flags & MTD_WRITEABLE) &&
529 	    mtd_mod_by_eb(slave->offset, &slave->mtd)) {
530 		/* Doesn't start on a boundary of major erase size */
531 		/* FIXME: Let it be writable if it is on a boundary of
532 		 * _minor_ erase size though */
533 		slave->mtd.flags &= ~MTD_WRITEABLE;
534 		printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",
535 			part->name);
536 	}
537 	if ((slave->mtd.flags & MTD_WRITEABLE) &&
538 	    mtd_mod_by_eb(slave->mtd.size, &slave->mtd)) {
539 		slave->mtd.flags &= ~MTD_WRITEABLE;
540 		printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
541 			part->name);
542 	}
543 
544 	slave->mtd.ecclayout = master->ecclayout;
545 	if (master->block_isbad) {
546 		uint64_t offs = 0;
547 
548 		while (offs < slave->mtd.size) {
549 			if (master->block_isbad(master,
550 						offs + slave->offset))
551 				slave->mtd.ecc_stats.badblocks++;
552 			offs += slave->mtd.erasesize;
553 		}
554 	}
555 
556 out_register:
557 	return slave;
558 }
559 
560 int mtd_add_partition(struct mtd_info *master, char *name,
561 		      long long offset, long long length)
562 {
563 	struct mtd_partition part;
564 	struct mtd_part *p, *new;
565 	uint64_t start, end;
566 	int ret = 0;
567 
568 	/* the direct offset is expected */
569 	if (offset == MTDPART_OFS_APPEND ||
570 	    offset == MTDPART_OFS_NXTBLK)
571 		return -EINVAL;
572 
573 	if (length == MTDPART_SIZ_FULL)
574 		length = master->size - offset;
575 
576 	if (length <= 0)
577 		return -EINVAL;
578 
579 	part.name = name;
580 	part.size = length;
581 	part.offset = offset;
582 	part.mask_flags = 0;
583 	part.ecclayout = NULL;
584 
585 	new = allocate_partition(master, &part, -1, offset);
586 	if (IS_ERR(new))
587 		return PTR_ERR(new);
588 
589 	start = offset;
590 	end = offset + length;
591 
592 	mutex_lock(&mtd_partitions_mutex);
593 	list_for_each_entry(p, &mtd_partitions, list)
594 		if (p->master == master) {
595 			if ((start >= p->offset) &&
596 			    (start < (p->offset + p->mtd.size)))
597 				goto err_inv;
598 
599 			if ((end >= p->offset) &&
600 			    (end < (p->offset + p->mtd.size)))
601 				goto err_inv;
602 		}
603 
604 	list_add(&new->list, &mtd_partitions);
605 	mutex_unlock(&mtd_partitions_mutex);
606 
607 	add_mtd_device(&new->mtd);
608 
609 	return ret;
610 err_inv:
611 	mutex_unlock(&mtd_partitions_mutex);
612 	free_partition(new);
613 	return -EINVAL;
614 }
615 EXPORT_SYMBOL_GPL(mtd_add_partition);
616 
617 int mtd_del_partition(struct mtd_info *master, int partno)
618 {
619 	struct mtd_part *slave, *next;
620 	int ret = -EINVAL;
621 
622 	mutex_lock(&mtd_partitions_mutex);
623 	list_for_each_entry_safe(slave, next, &mtd_partitions, list)
624 		if ((slave->master == master) &&
625 		    (slave->mtd.index == partno)) {
626 			ret = del_mtd_device(&slave->mtd);
627 			if (ret < 0)
628 				break;
629 
630 			list_del(&slave->list);
631 			free_partition(slave);
632 			break;
633 		}
634 	mutex_unlock(&mtd_partitions_mutex);
635 
636 	return ret;
637 }
638 EXPORT_SYMBOL_GPL(mtd_del_partition);
639 
640 /*
641  * This function, given a master MTD object and a partition table, creates
642  * and registers slave MTD objects which are bound to the master according to
643  * the partition definitions.
644  *
645  * We don't register the master, or expect the caller to have done so,
646  * for reasons of data integrity.
647  */
648 
649 int add_mtd_partitions(struct mtd_info *master,
650 		       const struct mtd_partition *parts,
651 		       int nbparts)
652 {
653 	struct mtd_part *slave;
654 	uint64_t cur_offset = 0;
655 	int i;
656 
657 	printk(KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);
658 
659 	for (i = 0; i < nbparts; i++) {
660 		slave = allocate_partition(master, parts + i, i, cur_offset);
661 		if (IS_ERR(slave))
662 			return PTR_ERR(slave);
663 
664 		mutex_lock(&mtd_partitions_mutex);
665 		list_add(&slave->list, &mtd_partitions);
666 		mutex_unlock(&mtd_partitions_mutex);
667 
668 		add_mtd_device(&slave->mtd);
669 
670 		cur_offset = slave->offset + slave->mtd.size;
671 	}
672 
673 	return 0;
674 }
675 
676 static DEFINE_SPINLOCK(part_parser_lock);
677 static LIST_HEAD(part_parsers);
678 
679 static struct mtd_part_parser *get_partition_parser(const char *name)
680 {
681 	struct mtd_part_parser *p, *ret = NULL;
682 
683 	spin_lock(&part_parser_lock);
684 
685 	list_for_each_entry(p, &part_parsers, list)
686 		if (!strcmp(p->name, name) && try_module_get(p->owner)) {
687 			ret = p;
688 			break;
689 		}
690 
691 	spin_unlock(&part_parser_lock);
692 
693 	return ret;
694 }
695 
696 int register_mtd_parser(struct mtd_part_parser *p)
697 {
698 	spin_lock(&part_parser_lock);
699 	list_add(&p->list, &part_parsers);
700 	spin_unlock(&part_parser_lock);
701 
702 	return 0;
703 }
704 EXPORT_SYMBOL_GPL(register_mtd_parser);
705 
706 int deregister_mtd_parser(struct mtd_part_parser *p)
707 {
708 	spin_lock(&part_parser_lock);
709 	list_del(&p->list);
710 	spin_unlock(&part_parser_lock);
711 	return 0;
712 }
713 EXPORT_SYMBOL_GPL(deregister_mtd_parser);
714 
715 int parse_mtd_partitions(struct mtd_info *master, const char **types,
716 			 struct mtd_partition **pparts, unsigned long origin)
717 {
718 	struct mtd_part_parser *parser;
719 	int ret = 0;
720 
721 	for ( ; ret <= 0 && *types; types++) {
722 		parser = get_partition_parser(*types);
723 		if (!parser && !request_module("%s", *types))
724 				parser = get_partition_parser(*types);
725 		if (!parser)
726 			continue;
727 		ret = (*parser->parse_fn)(master, pparts, origin);
728 		if (ret > 0) {
729 			printk(KERN_NOTICE "%d %s partitions found on MTD device %s\n",
730 			       ret, parser->name, master->name);
731 		}
732 		put_partition_parser(parser);
733 	}
734 	return ret;
735 }
736 EXPORT_SYMBOL_GPL(parse_mtd_partitions);
737 
738 int mtd_is_partition(struct mtd_info *mtd)
739 {
740 	struct mtd_part *part;
741 	int ispart = 0;
742 
743 	mutex_lock(&mtd_partitions_mutex);
744 	list_for_each_entry(part, &mtd_partitions, list)
745 		if (&part->mtd == mtd) {
746 			ispart = 1;
747 			break;
748 		}
749 	mutex_unlock(&mtd_partitions_mutex);
750 
751 	return ispart;
752 }
753 EXPORT_SYMBOL_GPL(mtd_is_partition);
754