xref: /linux/drivers/mtd/mtdpart.c (revision 95db3b255fde4e830e5f8cc011eb404023f669d4)
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 #include <linux/kconfig.h>
34 
35 #include "mtdcore.h"
36 
37 /* Our partition linked list */
38 static LIST_HEAD(mtd_partitions);
39 static DEFINE_MUTEX(mtd_partitions_mutex);
40 
41 /* Our partition node structure */
42 struct mtd_part {
43 	struct mtd_info mtd;
44 	struct mtd_info *master;
45 	uint64_t offset;
46 	struct list_head list;
47 };
48 
49 /*
50  * Given a pointer to the MTD object in the mtd_part structure, we can retrieve
51  * the pointer to that structure.
52  */
53 static inline struct mtd_part *mtd_to_part(const struct mtd_info *mtd)
54 {
55 	return container_of(mtd, struct mtd_part, mtd);
56 }
57 
58 
59 /*
60  * MTD methods which simply translate the effective address and pass through
61  * to the _real_ device.
62  */
63 
64 static int part_read(struct mtd_info *mtd, loff_t from, size_t len,
65 		size_t *retlen, u_char *buf)
66 {
67 	struct mtd_part *part = mtd_to_part(mtd);
68 	struct mtd_ecc_stats stats;
69 	int res;
70 
71 	stats = part->master->ecc_stats;
72 	res = part->master->_read(part->master, from + part->offset, len,
73 				  retlen, buf);
74 	if (unlikely(mtd_is_eccerr(res)))
75 		mtd->ecc_stats.failed +=
76 			part->master->ecc_stats.failed - stats.failed;
77 	else
78 		mtd->ecc_stats.corrected +=
79 			part->master->ecc_stats.corrected - stats.corrected;
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 = mtd_to_part(mtd);
87 
88 	return part->master->_point(part->master, from + part->offset, len,
89 				    retlen, virt, phys);
90 }
91 
92 static int part_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
93 {
94 	struct mtd_part *part = mtd_to_part(mtd);
95 
96 	return part->master->_unpoint(part->master, from + part->offset, len);
97 }
98 
99 static unsigned long part_get_unmapped_area(struct mtd_info *mtd,
100 					    unsigned long len,
101 					    unsigned long offset,
102 					    unsigned long flags)
103 {
104 	struct mtd_part *part = mtd_to_part(mtd);
105 
106 	offset += part->offset;
107 	return part->master->_get_unmapped_area(part->master, len, offset,
108 						flags);
109 }
110 
111 static int part_read_oob(struct mtd_info *mtd, loff_t from,
112 		struct mtd_oob_ops *ops)
113 {
114 	struct mtd_part *part = mtd_to_part(mtd);
115 	int res;
116 
117 	if (from >= mtd->size)
118 		return -EINVAL;
119 	if (ops->datbuf && from + ops->len > mtd->size)
120 		return -EINVAL;
121 
122 	/*
123 	 * If OOB is also requested, make sure that we do not read past the end
124 	 * of this partition.
125 	 */
126 	if (ops->oobbuf) {
127 		size_t len, pages;
128 
129 		len = mtd_oobavail(mtd, ops);
130 		pages = mtd_div_by_ws(mtd->size, mtd);
131 		pages -= mtd_div_by_ws(from, mtd);
132 		if (ops->ooboffs + ops->ooblen > pages * len)
133 			return -EINVAL;
134 	}
135 
136 	res = part->master->_read_oob(part->master, from + part->offset, ops);
137 	if (unlikely(res)) {
138 		if (mtd_is_bitflip(res))
139 			mtd->ecc_stats.corrected++;
140 		if (mtd_is_eccerr(res))
141 			mtd->ecc_stats.failed++;
142 	}
143 	return res;
144 }
145 
146 static int part_read_user_prot_reg(struct mtd_info *mtd, loff_t from,
147 		size_t len, size_t *retlen, u_char *buf)
148 {
149 	struct mtd_part *part = mtd_to_part(mtd);
150 	return part->master->_read_user_prot_reg(part->master, from, len,
151 						 retlen, buf);
152 }
153 
154 static int part_get_user_prot_info(struct mtd_info *mtd, size_t len,
155 				   size_t *retlen, struct otp_info *buf)
156 {
157 	struct mtd_part *part = mtd_to_part(mtd);
158 	return part->master->_get_user_prot_info(part->master, len, retlen,
159 						 buf);
160 }
161 
162 static int part_read_fact_prot_reg(struct mtd_info *mtd, loff_t from,
163 		size_t len, size_t *retlen, u_char *buf)
164 {
165 	struct mtd_part *part = mtd_to_part(mtd);
166 	return part->master->_read_fact_prot_reg(part->master, from, len,
167 						 retlen, buf);
168 }
169 
170 static int part_get_fact_prot_info(struct mtd_info *mtd, size_t len,
171 				   size_t *retlen, struct otp_info *buf)
172 {
173 	struct mtd_part *part = mtd_to_part(mtd);
174 	return part->master->_get_fact_prot_info(part->master, len, retlen,
175 						 buf);
176 }
177 
178 static int part_write(struct mtd_info *mtd, loff_t to, size_t len,
179 		size_t *retlen, const u_char *buf)
180 {
181 	struct mtd_part *part = mtd_to_part(mtd);
182 	return part->master->_write(part->master, to + part->offset, len,
183 				    retlen, buf);
184 }
185 
186 static int part_panic_write(struct mtd_info *mtd, loff_t to, size_t len,
187 		size_t *retlen, const u_char *buf)
188 {
189 	struct mtd_part *part = mtd_to_part(mtd);
190 	return part->master->_panic_write(part->master, to + part->offset, len,
191 					  retlen, buf);
192 }
193 
194 static int part_write_oob(struct mtd_info *mtd, loff_t to,
195 		struct mtd_oob_ops *ops)
196 {
197 	struct mtd_part *part = mtd_to_part(mtd);
198 
199 	if (to >= mtd->size)
200 		return -EINVAL;
201 	if (ops->datbuf && to + ops->len > mtd->size)
202 		return -EINVAL;
203 	return part->master->_write_oob(part->master, to + part->offset, ops);
204 }
205 
206 static int part_write_user_prot_reg(struct mtd_info *mtd, loff_t from,
207 		size_t len, size_t *retlen, u_char *buf)
208 {
209 	struct mtd_part *part = mtd_to_part(mtd);
210 	return part->master->_write_user_prot_reg(part->master, from, len,
211 						  retlen, buf);
212 }
213 
214 static int part_lock_user_prot_reg(struct mtd_info *mtd, loff_t from,
215 		size_t len)
216 {
217 	struct mtd_part *part = mtd_to_part(mtd);
218 	return part->master->_lock_user_prot_reg(part->master, from, len);
219 }
220 
221 static int part_writev(struct mtd_info *mtd, const struct kvec *vecs,
222 		unsigned long count, loff_t to, size_t *retlen)
223 {
224 	struct mtd_part *part = mtd_to_part(mtd);
225 	return part->master->_writev(part->master, vecs, count,
226 				     to + part->offset, retlen);
227 }
228 
229 static int part_erase(struct mtd_info *mtd, struct erase_info *instr)
230 {
231 	struct mtd_part *part = mtd_to_part(mtd);
232 	int ret;
233 
234 	instr->addr += part->offset;
235 	ret = part->master->_erase(part->master, instr);
236 	if (ret) {
237 		if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
238 			instr->fail_addr -= part->offset;
239 		instr->addr -= part->offset;
240 	}
241 	return ret;
242 }
243 
244 void mtd_erase_callback(struct erase_info *instr)
245 {
246 	if (instr->mtd->_erase == part_erase) {
247 		struct mtd_part *part = mtd_to_part(instr->mtd);
248 
249 		if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
250 			instr->fail_addr -= part->offset;
251 		instr->addr -= part->offset;
252 	}
253 	if (instr->callback)
254 		instr->callback(instr);
255 }
256 EXPORT_SYMBOL_GPL(mtd_erase_callback);
257 
258 static int part_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
259 {
260 	struct mtd_part *part = mtd_to_part(mtd);
261 	return part->master->_lock(part->master, ofs + part->offset, len);
262 }
263 
264 static int part_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
265 {
266 	struct mtd_part *part = mtd_to_part(mtd);
267 	return part->master->_unlock(part->master, ofs + part->offset, len);
268 }
269 
270 static int part_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
271 {
272 	struct mtd_part *part = mtd_to_part(mtd);
273 	return part->master->_is_locked(part->master, ofs + part->offset, len);
274 }
275 
276 static void part_sync(struct mtd_info *mtd)
277 {
278 	struct mtd_part *part = mtd_to_part(mtd);
279 	part->master->_sync(part->master);
280 }
281 
282 static int part_suspend(struct mtd_info *mtd)
283 {
284 	struct mtd_part *part = mtd_to_part(mtd);
285 	return part->master->_suspend(part->master);
286 }
287 
288 static void part_resume(struct mtd_info *mtd)
289 {
290 	struct mtd_part *part = mtd_to_part(mtd);
291 	part->master->_resume(part->master);
292 }
293 
294 static int part_block_isreserved(struct mtd_info *mtd, loff_t ofs)
295 {
296 	struct mtd_part *part = mtd_to_part(mtd);
297 	ofs += part->offset;
298 	return part->master->_block_isreserved(part->master, ofs);
299 }
300 
301 static int part_block_isbad(struct mtd_info *mtd, loff_t ofs)
302 {
303 	struct mtd_part *part = mtd_to_part(mtd);
304 	ofs += part->offset;
305 	return part->master->_block_isbad(part->master, ofs);
306 }
307 
308 static int part_block_markbad(struct mtd_info *mtd, loff_t ofs)
309 {
310 	struct mtd_part *part = mtd_to_part(mtd);
311 	int res;
312 
313 	ofs += part->offset;
314 	res = part->master->_block_markbad(part->master, ofs);
315 	if (!res)
316 		mtd->ecc_stats.badblocks++;
317 	return res;
318 }
319 
320 static int part_ooblayout_ecc(struct mtd_info *mtd, int section,
321 			      struct mtd_oob_region *oobregion)
322 {
323 	struct mtd_part *part = mtd_to_part(mtd);
324 
325 	return mtd_ooblayout_ecc(part->master, section, oobregion);
326 }
327 
328 static int part_ooblayout_free(struct mtd_info *mtd, int section,
329 			       struct mtd_oob_region *oobregion)
330 {
331 	struct mtd_part *part = mtd_to_part(mtd);
332 
333 	return mtd_ooblayout_free(part->master, section, oobregion);
334 }
335 
336 static const struct mtd_ooblayout_ops part_ooblayout_ops = {
337 	.ecc = part_ooblayout_ecc,
338 	.free = part_ooblayout_free,
339 };
340 
341 static inline void free_partition(struct mtd_part *p)
342 {
343 	kfree(p->mtd.name);
344 	kfree(p);
345 }
346 
347 /*
348  * This function unregisters and destroy all slave MTD objects which are
349  * attached to the given master MTD object.
350  */
351 
352 int del_mtd_partitions(struct mtd_info *master)
353 {
354 	struct mtd_part *slave, *next;
355 	int ret, err = 0;
356 
357 	mutex_lock(&mtd_partitions_mutex);
358 	list_for_each_entry_safe(slave, next, &mtd_partitions, list)
359 		if (slave->master == master) {
360 			ret = del_mtd_device(&slave->mtd);
361 			if (ret < 0) {
362 				err = ret;
363 				continue;
364 			}
365 			list_del(&slave->list);
366 			free_partition(slave);
367 		}
368 	mutex_unlock(&mtd_partitions_mutex);
369 
370 	return err;
371 }
372 
373 static struct mtd_part *allocate_partition(struct mtd_info *master,
374 			const struct mtd_partition *part, int partno,
375 			uint64_t cur_offset)
376 {
377 	struct mtd_part *slave;
378 	char *name;
379 
380 	/* allocate the partition structure */
381 	slave = kzalloc(sizeof(*slave), GFP_KERNEL);
382 	name = kstrdup(part->name, GFP_KERNEL);
383 	if (!name || !slave) {
384 		printk(KERN_ERR"memory allocation error while creating partitions for \"%s\"\n",
385 		       master->name);
386 		kfree(name);
387 		kfree(slave);
388 		return ERR_PTR(-ENOMEM);
389 	}
390 
391 	/* set up the MTD object for this partition */
392 	slave->mtd.type = master->type;
393 	slave->mtd.flags = master->flags & ~part->mask_flags;
394 	slave->mtd.size = part->size;
395 	slave->mtd.writesize = master->writesize;
396 	slave->mtd.writebufsize = master->writebufsize;
397 	slave->mtd.oobsize = master->oobsize;
398 	slave->mtd.oobavail = master->oobavail;
399 	slave->mtd.subpage_sft = master->subpage_sft;
400 
401 	slave->mtd.name = name;
402 	slave->mtd.owner = master->owner;
403 
404 	/* NOTE: Historically, we didn't arrange MTDs as a tree out of
405 	 * concern for showing the same data in multiple partitions.
406 	 * However, it is very useful to have the master node present,
407 	 * so the MTD_PARTITIONED_MASTER option allows that. The master
408 	 * will have device nodes etc only if this is set, so make the
409 	 * parent conditional on that option. Note, this is a way to
410 	 * distinguish between the master and the partition in sysfs.
411 	 */
412 	slave->mtd.dev.parent = IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER) ?
413 				&master->dev :
414 				master->dev.parent;
415 
416 	slave->mtd._read = part_read;
417 	slave->mtd._write = part_write;
418 
419 	if (master->_panic_write)
420 		slave->mtd._panic_write = part_panic_write;
421 
422 	if (master->_point && master->_unpoint) {
423 		slave->mtd._point = part_point;
424 		slave->mtd._unpoint = part_unpoint;
425 	}
426 
427 	if (master->_get_unmapped_area)
428 		slave->mtd._get_unmapped_area = part_get_unmapped_area;
429 	if (master->_read_oob)
430 		slave->mtd._read_oob = part_read_oob;
431 	if (master->_write_oob)
432 		slave->mtd._write_oob = part_write_oob;
433 	if (master->_read_user_prot_reg)
434 		slave->mtd._read_user_prot_reg = part_read_user_prot_reg;
435 	if (master->_read_fact_prot_reg)
436 		slave->mtd._read_fact_prot_reg = part_read_fact_prot_reg;
437 	if (master->_write_user_prot_reg)
438 		slave->mtd._write_user_prot_reg = part_write_user_prot_reg;
439 	if (master->_lock_user_prot_reg)
440 		slave->mtd._lock_user_prot_reg = part_lock_user_prot_reg;
441 	if (master->_get_user_prot_info)
442 		slave->mtd._get_user_prot_info = part_get_user_prot_info;
443 	if (master->_get_fact_prot_info)
444 		slave->mtd._get_fact_prot_info = part_get_fact_prot_info;
445 	if (master->_sync)
446 		slave->mtd._sync = part_sync;
447 	if (!partno && !master->dev.class && master->_suspend &&
448 	    master->_resume) {
449 			slave->mtd._suspend = part_suspend;
450 			slave->mtd._resume = part_resume;
451 	}
452 	if (master->_writev)
453 		slave->mtd._writev = part_writev;
454 	if (master->_lock)
455 		slave->mtd._lock = part_lock;
456 	if (master->_unlock)
457 		slave->mtd._unlock = part_unlock;
458 	if (master->_is_locked)
459 		slave->mtd._is_locked = part_is_locked;
460 	if (master->_block_isreserved)
461 		slave->mtd._block_isreserved = part_block_isreserved;
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->offset == MTDPART_OFS_RETAIN) {
483 		slave->offset = cur_offset;
484 		if (master->size - slave->offset >= slave->mtd.size) {
485 			slave->mtd.size = master->size - slave->offset
486 							- slave->mtd.size;
487 		} else {
488 			printk(KERN_ERR "mtd partition \"%s\" doesn't have enough space: %#llx < %#llx, disabled\n",
489 				part->name, master->size - slave->offset,
490 				slave->mtd.size);
491 			/* register to preserve ordering */
492 			goto out_register;
493 		}
494 	}
495 	if (slave->mtd.size == MTDPART_SIZ_FULL)
496 		slave->mtd.size = master->size - slave->offset;
497 
498 	printk(KERN_NOTICE "0x%012llx-0x%012llx : \"%s\"\n", (unsigned long long)slave->offset,
499 		(unsigned long long)(slave->offset + slave->mtd.size), slave->mtd.name);
500 
501 	/* let's do some sanity checks */
502 	if (slave->offset >= master->size) {
503 		/* let's register it anyway to preserve ordering */
504 		slave->offset = 0;
505 		slave->mtd.size = 0;
506 		printk(KERN_ERR"mtd: partition \"%s\" is out of reach -- disabled\n",
507 			part->name);
508 		goto out_register;
509 	}
510 	if (slave->offset + slave->mtd.size > master->size) {
511 		slave->mtd.size = master->size - slave->offset;
512 		printk(KERN_WARNING"mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#llx\n",
513 			part->name, master->name, (unsigned long long)slave->mtd.size);
514 	}
515 	if (master->numeraseregions > 1) {
516 		/* Deal with variable erase size stuff */
517 		int i, max = master->numeraseregions;
518 		u64 end = slave->offset + slave->mtd.size;
519 		struct mtd_erase_region_info *regions = master->eraseregions;
520 
521 		/* Find the first erase regions which is part of this
522 		 * partition. */
523 		for (i = 0; i < max && regions[i].offset <= slave->offset; i++)
524 			;
525 		/* The loop searched for the region _behind_ the first one */
526 		if (i > 0)
527 			i--;
528 
529 		/* Pick biggest erasesize */
530 		for (; i < max && regions[i].offset < end; i++) {
531 			if (slave->mtd.erasesize < regions[i].erasesize) {
532 				slave->mtd.erasesize = regions[i].erasesize;
533 			}
534 		}
535 		BUG_ON(slave->mtd.erasesize == 0);
536 	} else {
537 		/* Single erase size */
538 		slave->mtd.erasesize = master->erasesize;
539 	}
540 
541 	if ((slave->mtd.flags & MTD_WRITEABLE) &&
542 	    mtd_mod_by_eb(slave->offset, &slave->mtd)) {
543 		/* Doesn't start on a boundary of major erase size */
544 		/* FIXME: Let it be writable if it is on a boundary of
545 		 * _minor_ erase size though */
546 		slave->mtd.flags &= ~MTD_WRITEABLE;
547 		printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",
548 			part->name);
549 	}
550 	if ((slave->mtd.flags & MTD_WRITEABLE) &&
551 	    mtd_mod_by_eb(slave->mtd.size, &slave->mtd)) {
552 		slave->mtd.flags &= ~MTD_WRITEABLE;
553 		printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
554 			part->name);
555 	}
556 
557 	mtd_set_ooblayout(&slave->mtd, &part_ooblayout_ops);
558 	slave->mtd.ecc_step_size = master->ecc_step_size;
559 	slave->mtd.ecc_strength = master->ecc_strength;
560 	slave->mtd.bitflip_threshold = master->bitflip_threshold;
561 
562 	if (master->_block_isbad) {
563 		uint64_t offs = 0;
564 
565 		while (offs < slave->mtd.size) {
566 			if (mtd_block_isreserved(master, offs + slave->offset))
567 				slave->mtd.ecc_stats.bbtblocks++;
568 			else if (mtd_block_isbad(master, offs + slave->offset))
569 				slave->mtd.ecc_stats.badblocks++;
570 			offs += slave->mtd.erasesize;
571 		}
572 	}
573 
574 out_register:
575 	return slave;
576 }
577 
578 static ssize_t mtd_partition_offset_show(struct device *dev,
579 		struct device_attribute *attr, char *buf)
580 {
581 	struct mtd_info *mtd = dev_get_drvdata(dev);
582 	struct mtd_part *part = mtd_to_part(mtd);
583 	return snprintf(buf, PAGE_SIZE, "%lld\n", part->offset);
584 }
585 
586 static DEVICE_ATTR(offset, S_IRUGO, mtd_partition_offset_show, NULL);
587 
588 static const struct attribute *mtd_partition_attrs[] = {
589 	&dev_attr_offset.attr,
590 	NULL
591 };
592 
593 static int mtd_add_partition_attrs(struct mtd_part *new)
594 {
595 	int ret = sysfs_create_files(&new->mtd.dev.kobj, mtd_partition_attrs);
596 	if (ret)
597 		printk(KERN_WARNING
598 		       "mtd: failed to create partition attrs, err=%d\n", ret);
599 	return ret;
600 }
601 
602 int mtd_add_partition(struct mtd_info *master, const char *name,
603 		      long long offset, long long length)
604 {
605 	struct mtd_partition part;
606 	struct mtd_part *new;
607 	int ret = 0;
608 
609 	/* the direct offset is expected */
610 	if (offset == MTDPART_OFS_APPEND ||
611 	    offset == MTDPART_OFS_NXTBLK)
612 		return -EINVAL;
613 
614 	if (length == MTDPART_SIZ_FULL)
615 		length = master->size - offset;
616 
617 	if (length <= 0)
618 		return -EINVAL;
619 
620 	memset(&part, 0, sizeof(part));
621 	part.name = name;
622 	part.size = length;
623 	part.offset = offset;
624 
625 	new = allocate_partition(master, &part, -1, offset);
626 	if (IS_ERR(new))
627 		return PTR_ERR(new);
628 
629 	mutex_lock(&mtd_partitions_mutex);
630 	list_add(&new->list, &mtd_partitions);
631 	mutex_unlock(&mtd_partitions_mutex);
632 
633 	add_mtd_device(&new->mtd);
634 
635 	mtd_add_partition_attrs(new);
636 
637 	return ret;
638 }
639 EXPORT_SYMBOL_GPL(mtd_add_partition);
640 
641 int mtd_del_partition(struct mtd_info *master, int partno)
642 {
643 	struct mtd_part *slave, *next;
644 	int ret = -EINVAL;
645 
646 	mutex_lock(&mtd_partitions_mutex);
647 	list_for_each_entry_safe(slave, next, &mtd_partitions, list)
648 		if ((slave->master == master) &&
649 		    (slave->mtd.index == partno)) {
650 			sysfs_remove_files(&slave->mtd.dev.kobj,
651 					   mtd_partition_attrs);
652 			ret = del_mtd_device(&slave->mtd);
653 			if (ret < 0)
654 				break;
655 
656 			list_del(&slave->list);
657 			free_partition(slave);
658 			break;
659 		}
660 	mutex_unlock(&mtd_partitions_mutex);
661 
662 	return ret;
663 }
664 EXPORT_SYMBOL_GPL(mtd_del_partition);
665 
666 /*
667  * This function, given a master MTD object and a partition table, creates
668  * and registers slave MTD objects which are bound to the master according to
669  * the partition definitions.
670  *
671  * For historical reasons, this function's caller only registers the master
672  * if the MTD_PARTITIONED_MASTER config option is set.
673  */
674 
675 int add_mtd_partitions(struct mtd_info *master,
676 		       const struct mtd_partition *parts,
677 		       int nbparts)
678 {
679 	struct mtd_part *slave;
680 	uint64_t cur_offset = 0;
681 	int i;
682 
683 	printk(KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);
684 
685 	for (i = 0; i < nbparts; i++) {
686 		slave = allocate_partition(master, parts + i, i, cur_offset);
687 		if (IS_ERR(slave)) {
688 			del_mtd_partitions(master);
689 			return PTR_ERR(slave);
690 		}
691 
692 		mutex_lock(&mtd_partitions_mutex);
693 		list_add(&slave->list, &mtd_partitions);
694 		mutex_unlock(&mtd_partitions_mutex);
695 
696 		add_mtd_device(&slave->mtd);
697 		mtd_add_partition_attrs(slave);
698 
699 		cur_offset = slave->offset + slave->mtd.size;
700 	}
701 
702 	return 0;
703 }
704 
705 static DEFINE_SPINLOCK(part_parser_lock);
706 static LIST_HEAD(part_parsers);
707 
708 static struct mtd_part_parser *mtd_part_parser_get(const char *name)
709 {
710 	struct mtd_part_parser *p, *ret = NULL;
711 
712 	spin_lock(&part_parser_lock);
713 
714 	list_for_each_entry(p, &part_parsers, list)
715 		if (!strcmp(p->name, name) && try_module_get(p->owner)) {
716 			ret = p;
717 			break;
718 		}
719 
720 	spin_unlock(&part_parser_lock);
721 
722 	return ret;
723 }
724 
725 static inline void mtd_part_parser_put(const struct mtd_part_parser *p)
726 {
727 	module_put(p->owner);
728 }
729 
730 /*
731  * Many partition parsers just expected the core to kfree() all their data in
732  * one chunk. Do that by default.
733  */
734 static void mtd_part_parser_cleanup_default(const struct mtd_partition *pparts,
735 					    int nr_parts)
736 {
737 	kfree(pparts);
738 }
739 
740 int __register_mtd_parser(struct mtd_part_parser *p, struct module *owner)
741 {
742 	p->owner = owner;
743 
744 	if (!p->cleanup)
745 		p->cleanup = &mtd_part_parser_cleanup_default;
746 
747 	spin_lock(&part_parser_lock);
748 	list_add(&p->list, &part_parsers);
749 	spin_unlock(&part_parser_lock);
750 
751 	return 0;
752 }
753 EXPORT_SYMBOL_GPL(__register_mtd_parser);
754 
755 void deregister_mtd_parser(struct mtd_part_parser *p)
756 {
757 	spin_lock(&part_parser_lock);
758 	list_del(&p->list);
759 	spin_unlock(&part_parser_lock);
760 }
761 EXPORT_SYMBOL_GPL(deregister_mtd_parser);
762 
763 /*
764  * Do not forget to update 'parse_mtd_partitions()' kerneldoc comment if you
765  * are changing this array!
766  */
767 static const char * const default_mtd_part_types[] = {
768 	"cmdlinepart",
769 	"ofpart",
770 	NULL
771 };
772 
773 /**
774  * parse_mtd_partitions - parse MTD partitions
775  * @master: the master partition (describes whole MTD device)
776  * @types: names of partition parsers to try or %NULL
777  * @pparts: info about partitions found is returned here
778  * @data: MTD partition parser-specific data
779  *
780  * This function tries to find partition on MTD device @master. It uses MTD
781  * partition parsers, specified in @types. However, if @types is %NULL, then
782  * the default list of parsers is used. The default list contains only the
783  * "cmdlinepart" and "ofpart" parsers ATM.
784  * Note: If there are more then one parser in @types, the kernel only takes the
785  * partitions parsed out by the first parser.
786  *
787  * This function may return:
788  * o a negative error code in case of failure
789  * o zero otherwise, and @pparts will describe the partitions, number of
790  *   partitions, and the parser which parsed them. Caller must release
791  *   resources with mtd_part_parser_cleanup() when finished with the returned
792  *   data.
793  */
794 int parse_mtd_partitions(struct mtd_info *master, const char *const *types,
795 			 struct mtd_partitions *pparts,
796 			 struct mtd_part_parser_data *data)
797 {
798 	struct mtd_part_parser *parser;
799 	int ret, err = 0;
800 
801 	if (!types)
802 		types = default_mtd_part_types;
803 
804 	for ( ; *types; types++) {
805 		pr_debug("%s: parsing partitions %s\n", master->name, *types);
806 		parser = mtd_part_parser_get(*types);
807 		if (!parser && !request_module("%s", *types))
808 			parser = mtd_part_parser_get(*types);
809 		pr_debug("%s: got parser %s\n", master->name,
810 			 parser ? parser->name : NULL);
811 		if (!parser)
812 			continue;
813 		ret = (*parser->parse_fn)(master, &pparts->parts, data);
814 		pr_debug("%s: parser %s: %i\n",
815 			 master->name, parser->name, ret);
816 		if (ret > 0) {
817 			printk(KERN_NOTICE "%d %s partitions found on MTD device %s\n",
818 			       ret, parser->name, master->name);
819 			pparts->nr_parts = ret;
820 			pparts->parser = parser;
821 			return 0;
822 		}
823 		mtd_part_parser_put(parser);
824 		/*
825 		 * Stash the first error we see; only report it if no parser
826 		 * succeeds
827 		 */
828 		if (ret < 0 && !err)
829 			err = ret;
830 	}
831 	return err;
832 }
833 
834 void mtd_part_parser_cleanup(struct mtd_partitions *parts)
835 {
836 	const struct mtd_part_parser *parser;
837 
838 	if (!parts)
839 		return;
840 
841 	parser = parts->parser;
842 	if (parser) {
843 		if (parser->cleanup)
844 			parser->cleanup(parts->parts, parts->nr_parts);
845 
846 		mtd_part_parser_put(parser);
847 	}
848 }
849 
850 int mtd_is_partition(const struct mtd_info *mtd)
851 {
852 	struct mtd_part *part;
853 	int ispart = 0;
854 
855 	mutex_lock(&mtd_partitions_mutex);
856 	list_for_each_entry(part, &mtd_partitions, list)
857 		if (&part->mtd == mtd) {
858 			ispart = 1;
859 			break;
860 		}
861 	mutex_unlock(&mtd_partitions_mutex);
862 
863 	return ispart;
864 }
865 EXPORT_SYMBOL_GPL(mtd_is_partition);
866 
867 /* Returns the size of the entire flash chip */
868 uint64_t mtd_get_device_size(const struct mtd_info *mtd)
869 {
870 	if (!mtd_is_partition(mtd))
871 		return mtd->size;
872 
873 	return mtd_to_part(mtd)->master->size;
874 }
875 EXPORT_SYMBOL_GPL(mtd_get_device_size);
876