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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Simple MTD partitioning layer
4 *
5 * Copyright © 2000 Nicolas Pitre <nico@fluxnic.net>
6 * Copyright © 2002 Thomas Gleixner <gleixner@linutronix.de>
7 * Copyright © 2000-2010 David Woodhouse <dwmw2@infradead.org>
8 */
9
10#include <linux/module.h>
11#include <linux/types.h>
12#include <linux/kernel.h>
13#include <linux/slab.h>
14#include <linux/list.h>
15#include <linux/kmod.h>
16#include <linux/mtd/mtd.h>
17#include <linux/mtd/partitions.h>
18#include <linux/err.h>
19#include <linux/of.h>
20#include <linux/of_platform.h>
21
22#include "mtdcore.h"
23
24/*
25 * MTD methods which simply translate the effective address and pass through
26 * to the _real_ device.
27 */
28
29static inline void free_partition(struct mtd_info *mtd)
30{
31 kfree(mtd->name);
32 kfree(mtd);
33}
34
35void release_mtd_partition(struct mtd_info *mtd)
36{
37 WARN_ON(!list_empty(&mtd->part.node));
38 free_partition(mtd);
39}
40
41static struct mtd_info *allocate_partition(struct mtd_info *parent,
42 const struct mtd_partition *part,
43 int partno, uint64_t cur_offset)
44{
45 struct mtd_info *master = mtd_get_master(parent);
46 int wr_alignment = (parent->flags & MTD_NO_ERASE) ?
47 master->writesize : master->erasesize;
48 u64 parent_size = mtd_is_partition(parent) ?
49 parent->part.size : parent->size;
50 struct mtd_info *child;
51 u32 remainder;
52 char *name;
53 u64 tmp;
54
55 /* allocate the partition structure */
56 child = kzalloc(sizeof(*child), GFP_KERNEL);
57 name = kstrdup(part->name, GFP_KERNEL);
58 if (!name || !child) {
59 printk(KERN_ERR"memory allocation error while creating partitions for \"%s\"\n",
60 parent->name);
61 kfree(name);
62 kfree(child);
63 return ERR_PTR(-ENOMEM);
64 }
65
66 /* set up the MTD object for this partition */
67 child->type = parent->type;
68 child->part.flags = parent->flags & ~part->mask_flags;
69 child->part.flags |= part->add_flags;
70 child->flags = child->part.flags;
71 child->part.size = part->size;
72 child->writesize = parent->writesize;
73 child->writebufsize = parent->writebufsize;
74 child->oobsize = parent->oobsize;
75 child->oobavail = parent->oobavail;
76 child->subpage_sft = parent->subpage_sft;
77
78 child->name = name;
79 child->owner = parent->owner;
80
81 /* NOTE: Historically, we didn't arrange MTDs as a tree out of
82 * concern for showing the same data in multiple partitions.
83 * However, it is very useful to have the master node present,
84 * so the MTD_PARTITIONED_MASTER option allows that. The master
85 * will have device nodes etc only if this is set, so make the
86 * parent conditional on that option. Note, this is a way to
87 * distinguish between the parent and its partitions in sysfs.
88 */
89 child->dev.parent = IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER) || mtd_is_partition(parent) ?
90 &parent->dev : parent->dev.parent;
91 child->dev.of_node = part->of_node;
92 child->parent = parent;
93 child->part.offset = part->offset;
94 INIT_LIST_HEAD(&child->partitions);
95
96 if (child->part.offset == MTDPART_OFS_APPEND)
97 child->part.offset = cur_offset;
98 if (child->part.offset == MTDPART_OFS_NXTBLK) {
99 tmp = cur_offset;
100 child->part.offset = cur_offset;
101 remainder = do_div(tmp, wr_alignment);
102 if (remainder) {
103 child->part.offset += wr_alignment - remainder;
104 printk(KERN_NOTICE "Moving partition %d: "
105 "0x%012llx -> 0x%012llx\n", partno,
106 (unsigned long long)cur_offset,
107 child->part.offset);
108 }
109 }
110 if (child->part.offset == MTDPART_OFS_RETAIN) {
111 child->part.offset = cur_offset;
112 if (parent_size - child->part.offset >= child->part.size) {
113 child->part.size = parent_size - child->part.offset -
114 child->part.size;
115 } else {
116 printk(KERN_ERR "mtd partition \"%s\" doesn't have enough space: %#llx < %#llx, disabled\n",
117 part->name, parent_size - child->part.offset,
118 child->part.size);
119 /* register to preserve ordering */
120 goto out_register;
121 }
122 }
123 if (child->part.size == MTDPART_SIZ_FULL)
124 child->part.size = parent_size - child->part.offset;
125
126 printk(KERN_NOTICE "0x%012llx-0x%012llx : \"%s\"\n",
127 child->part.offset, child->part.offset + child->part.size,
128 child->name);
129
130 /* let's do some sanity checks */
131 if (child->part.offset >= parent_size) {
132 /* let's register it anyway to preserve ordering */
133 child->part.offset = 0;
134 child->part.size = 0;
135
136 /* Initialize ->erasesize to make add_mtd_device() happy. */
137 child->erasesize = parent->erasesize;
138 printk(KERN_ERR"mtd: partition \"%s\" is out of reach -- disabled\n",
139 part->name);
140 goto out_register;
141 }
142 if (child->part.offset + child->part.size > parent->size) {
143 child->part.size = parent_size - child->part.offset;
144 printk(KERN_WARNING"mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#llx\n",
145 part->name, parent->name, child->part.size);
146 }
147
148 if (parent->numeraseregions > 1) {
149 /* Deal with variable erase size stuff */
150 int i, max = parent->numeraseregions;
151 u64 end = child->part.offset + child->part.size;
152 struct mtd_erase_region_info *regions = parent->eraseregions;
153
154 /* Find the first erase regions which is part of this
155 * partition. */
156 for (i = 0; i < max && regions[i].offset <= child->part.offset;
157 i++)
158 ;
159 /* The loop searched for the region _behind_ the first one */
160 if (i > 0)
161 i--;
162
163 /* Pick biggest erasesize */
164 for (; i < max && regions[i].offset < end; i++) {
165 if (child->erasesize < regions[i].erasesize)
166 child->erasesize = regions[i].erasesize;
167 }
168 BUG_ON(child->erasesize == 0);
169 } else {
170 /* Single erase size */
171 child->erasesize = master->erasesize;
172 }
173
174 /*
175 * Child erasesize might differ from the parent one if the parent
176 * exposes several regions with different erasesize. Adjust
177 * wr_alignment accordingly.
178 */
179 if (!(child->flags & MTD_NO_ERASE))
180 wr_alignment = child->erasesize;
181
182 tmp = mtd_get_master_ofs(child, 0);
183 remainder = do_div(tmp, wr_alignment);
184 if ((child->flags & MTD_WRITEABLE) && remainder) {
185 /* Doesn't start on a boundary of major erase size */
186 /* FIXME: Let it be writable if it is on a boundary of
187 * _minor_ erase size though */
188 child->flags &= ~MTD_WRITEABLE;
189 printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase/write block boundary -- force read-only\n",
190 part->name);
191 }
192
193 tmp = mtd_get_master_ofs(child, 0) + child->part.size;
194 remainder = do_div(tmp, wr_alignment);
195 if ((child->flags & MTD_WRITEABLE) && remainder) {
196 child->flags &= ~MTD_WRITEABLE;
197 printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase/write block -- force read-only\n",
198 part->name);
199 }
200
201 child->size = child->part.size;
202 child->ecc_step_size = parent->ecc_step_size;
203 child->ecc_strength = parent->ecc_strength;
204 child->bitflip_threshold = parent->bitflip_threshold;
205
206 if (master->_block_isbad) {
207 uint64_t offs = 0;
208
209 while (offs < child->part.size) {
210 if (mtd_block_isreserved(child, offs))
211 child->ecc_stats.bbtblocks++;
212 else if (mtd_block_isbad(child, offs))
213 child->ecc_stats.badblocks++;
214 offs += child->erasesize;
215 }
216 }
217
218out_register:
219 return child;
220}
221
222static ssize_t offset_show(struct device *dev,
223 struct device_attribute *attr, char *buf)
224{
225 struct mtd_info *mtd = dev_get_drvdata(dev);
226
227 return sysfs_emit(buf, "%lld\n", mtd->part.offset);
228}
229static DEVICE_ATTR_RO(offset); /* mtd partition offset */
230
231static const struct attribute *mtd_partition_attrs[] = {
232 &dev_attr_offset.attr,
233 NULL
234};
235
236static int mtd_add_partition_attrs(struct mtd_info *new)
237{
238 int ret = sysfs_create_files(&new->dev.kobj, mtd_partition_attrs);
239 if (ret)
240 printk(KERN_WARNING
241 "mtd: failed to create partition attrs, err=%d\n", ret);
242 return ret;
243}
244
245int mtd_add_partition(struct mtd_info *parent, const char *name,
246 long long offset, long long length)
247{
248 struct mtd_info *master = mtd_get_master(parent);
249 u64 parent_size = mtd_is_partition(parent) ?
250 parent->part.size : parent->size;
251 struct mtd_partition part;
252 struct mtd_info *child;
253 int ret = 0;
254
255 /* the direct offset is expected */
256 if (offset == MTDPART_OFS_APPEND ||
257 offset == MTDPART_OFS_NXTBLK)
258 return -EINVAL;
259
260 if (length == MTDPART_SIZ_FULL)
261 length = parent_size - offset;
262
263 if (length <= 0)
264 return -EINVAL;
265
266 memset(&part, 0, sizeof(part));
267 part.name = name;
268 part.size = length;
269 part.offset = offset;
270
271 child = allocate_partition(parent, &part, -1, offset);
272 if (IS_ERR(child))
273 return PTR_ERR(child);
274
275 mutex_lock(&master->master.partitions_lock);
276 list_add_tail(&child->part.node, &parent->partitions);
277 mutex_unlock(&master->master.partitions_lock);
278
279 ret = add_mtd_device(child);
280 if (ret)
281 goto err_remove_part;
282
283 mtd_add_partition_attrs(child);
284
285 return 0;
286
287err_remove_part:
288 mutex_lock(&master->master.partitions_lock);
289 list_del(&child->part.node);
290 mutex_unlock(&master->master.partitions_lock);
291
292 free_partition(child);
293
294 return ret;
295}
296EXPORT_SYMBOL_GPL(mtd_add_partition);
297
298/**
299 * __mtd_del_partition - delete MTD partition
300 *
301 * @mtd: MTD structure to be deleted
302 *
303 * This function must be called with the partitions mutex locked.
304 */
305static int __mtd_del_partition(struct mtd_info *mtd)
306{
307 struct mtd_info *child, *next;
308 int err;
309
310 list_for_each_entry_safe(child, next, &mtd->partitions, part.node) {
311 err = __mtd_del_partition(child);
312 if (err)
313 return err;
314 }
315
316 sysfs_remove_files(&mtd->dev.kobj, mtd_partition_attrs);
317
318 list_del_init(&mtd->part.node);
319 err = del_mtd_device(mtd);
320 if (err)
321 return err;
322
323 return 0;
324}
325
326/*
327 * This function unregisters and destroy all slave MTD objects which are
328 * attached to the given MTD object, recursively.
329 */
330static int __del_mtd_partitions(struct mtd_info *mtd)
331{
332 struct mtd_info *child, *next;
333 int ret, err = 0;
334
335 list_for_each_entry_safe(child, next, &mtd->partitions, part.node) {
336 if (mtd_has_partitions(child))
337 __del_mtd_partitions(child);
338
339 pr_info("Deleting %s MTD partition\n", child->name);
340 list_del_init(&child->part.node);
341 ret = del_mtd_device(child);
342 if (ret < 0) {
343 pr_err("Error when deleting partition \"%s\" (%d)\n",
344 child->name, ret);
345 err = ret;
346 continue;
347 }
348 }
349
350 return err;
351}
352
353int del_mtd_partitions(struct mtd_info *mtd)
354{
355 struct mtd_info *master = mtd_get_master(mtd);
356 int ret;
357
358 pr_info("Deleting MTD partitions on \"%s\":\n", mtd->name);
359
360 mutex_lock(&master->master.partitions_lock);
361 ret = __del_mtd_partitions(mtd);
362 mutex_unlock(&master->master.partitions_lock);
363
364 return ret;
365}
366
367int mtd_del_partition(struct mtd_info *mtd, int partno)
368{
369 struct mtd_info *child, *master = mtd_get_master(mtd);
370 int ret = -EINVAL;
371
372 mutex_lock(&master->master.partitions_lock);
373 list_for_each_entry(child, &mtd->partitions, part.node) {
374 if (child->index == partno) {
375 ret = __mtd_del_partition(child);
376 break;
377 }
378 }
379 mutex_unlock(&master->master.partitions_lock);
380
381 return ret;
382}
383EXPORT_SYMBOL_GPL(mtd_del_partition);
384
385/*
386 * This function, given a parent MTD object and a partition table, creates
387 * and registers the child MTD objects which are bound to the parent according
388 * to the partition definitions.
389 *
390 * For historical reasons, this function's caller only registers the parent
391 * if the MTD_PARTITIONED_MASTER config option is set.
392 */
393
394int add_mtd_partitions(struct mtd_info *parent,
395 const struct mtd_partition *parts,
396 int nbparts)
397{
398 struct mtd_info *child, *master = mtd_get_master(parent);
399 uint64_t cur_offset = 0;
400 int i, ret;
401
402 printk(KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n",
403 nbparts, parent->name);
404
405 for (i = 0; i < nbparts; i++) {
406 child = allocate_partition(parent, parts + i, i, cur_offset);
407 if (IS_ERR(child)) {
408 ret = PTR_ERR(child);
409 goto err_del_partitions;
410 }
411
412 mutex_lock(&master->master.partitions_lock);
413 list_add_tail(&child->part.node, &parent->partitions);
414 mutex_unlock(&master->master.partitions_lock);
415
416 ret = add_mtd_device(child);
417 if (ret) {
418 mutex_lock(&master->master.partitions_lock);
419 list_del(&child->part.node);
420 mutex_unlock(&master->master.partitions_lock);
421
422 free_partition(child);
423 goto err_del_partitions;
424 }
425
426 mtd_add_partition_attrs(child);
427
428 /* Look for subpartitions */
429 ret = parse_mtd_partitions(child, parts[i].types, NULL);
430 if (ret < 0) {
431 pr_err("Failed to parse subpartitions: %d\n", ret);
432 goto err_del_partitions;
433 }
434
435 cur_offset = child->part.offset + child->part.size;
436 }
437
438 return 0;
439
440err_del_partitions:
441 del_mtd_partitions(master);
442
443 return ret;
444}
445
446static DEFINE_SPINLOCK(part_parser_lock);
447static LIST_HEAD(part_parsers);
448
449static struct mtd_part_parser *mtd_part_parser_get(const char *name)
450{
451 struct mtd_part_parser *p, *ret = NULL;
452
453 spin_lock(&part_parser_lock);
454
455 list_for_each_entry(p, &part_parsers, list)
456 if (!strcmp(p->name, name) && try_module_get(p->owner)) {
457 ret = p;
458 break;
459 }
460
461 spin_unlock(&part_parser_lock);
462
463 return ret;
464}
465
466static inline void mtd_part_parser_put(const struct mtd_part_parser *p)
467{
468 module_put(p->owner);
469}
470
471/*
472 * Many partition parsers just expected the core to kfree() all their data in
473 * one chunk. Do that by default.
474 */
475static void mtd_part_parser_cleanup_default(const struct mtd_partition *pparts,
476 int nr_parts)
477{
478 kfree(pparts);
479}
480
481int __register_mtd_parser(struct mtd_part_parser *p, struct module *owner)
482{
483 p->owner = owner;
484
485 if (!p->cleanup)
486 p->cleanup = &mtd_part_parser_cleanup_default;
487
488 spin_lock(&part_parser_lock);
489 list_add(&p->list, &part_parsers);
490 spin_unlock(&part_parser_lock);
491
492 return 0;
493}
494EXPORT_SYMBOL_GPL(__register_mtd_parser);
495
496void deregister_mtd_parser(struct mtd_part_parser *p)
497{
498 spin_lock(&part_parser_lock);
499 list_del(&p->list);
500 spin_unlock(&part_parser_lock);
501}
502EXPORT_SYMBOL_GPL(deregister_mtd_parser);
503
504/*
505 * Do not forget to update 'parse_mtd_partitions()' kerneldoc comment if you
506 * are changing this array!
507 */
508static const char * const default_mtd_part_types[] = {
509 "cmdlinepart",
510 "ofpart",
511 NULL
512};
513
514/* Check DT only when looking for subpartitions. */
515static const char * const default_subpartition_types[] = {
516 "ofpart",
517 NULL
518};
519
520static int mtd_part_do_parse(struct mtd_part_parser *parser,
521 struct mtd_info *master,
522 struct mtd_partitions *pparts,
523 struct mtd_part_parser_data *data)
524{
525 int ret;
526
527 ret = (*parser->parse_fn)(master, &pparts->parts, data);
528 pr_debug("%s: parser %s: %i\n", master->name, parser->name, ret);
529 if (ret <= 0)
530 return ret;
531
532 pr_notice("%d %s partitions found on MTD device %s\n", ret,
533 parser->name, master->name);
534
535 pparts->nr_parts = ret;
536 pparts->parser = parser;
537
538 return ret;
539}
540
541/**
542 * mtd_part_get_compatible_parser - find MTD parser by a compatible string
543 *
544 * @compat: compatible string describing partitions in a device tree
545 *
546 * MTD parsers can specify supported partitions by providing a table of
547 * compatibility strings. This function finds a parser that advertises support
548 * for a passed value of "compatible".
549 */
550static struct mtd_part_parser *mtd_part_get_compatible_parser(const char *compat)
551{
552 struct mtd_part_parser *p, *ret = NULL;
553
554 spin_lock(&part_parser_lock);
555
556 list_for_each_entry(p, &part_parsers, list) {
557 const struct of_device_id *matches;
558
559 matches = p->of_match_table;
560 if (!matches)
561 continue;
562
563 for (; matches->compatible[0]; matches++) {
564 if (!strcmp(matches->compatible, compat) &&
565 try_module_get(p->owner)) {
566 ret = p;
567 break;
568 }
569 }
570
571 if (ret)
572 break;
573 }
574
575 spin_unlock(&part_parser_lock);
576
577 return ret;
578}
579
580static int mtd_part_of_parse(struct mtd_info *master,
581 struct mtd_partitions *pparts)
582{
583 struct mtd_part_parser *parser;
584 struct device_node *np;
585 struct device_node *child;
586 struct property *prop;
587 struct device *dev;
588 const char *compat;
589 const char *fixed = "fixed-partitions";
590 int ret, err = 0;
591
592 dev = &master->dev;
593 /* Use parent device (controller) if the top level MTD is not registered */
594 if (!IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER) && !mtd_is_partition(master))
595 dev = master->dev.parent;
596
597 np = mtd_get_of_node(master);
598 if (mtd_is_partition(master))
599 of_node_get(np);
600 else
601 np = of_get_child_by_name(np, "partitions");
602
603 /*
604 * Don't create devices that are added to a bus but will never get
605 * probed. That'll cause fw_devlink to block probing of consumers of
606 * this partition until the partition device is probed.
607 */
608 for_each_child_of_node(np, child)
609 if (of_device_is_compatible(child, "nvmem-cells"))
610 of_node_set_flag(child, OF_POPULATED);
611
612 of_property_for_each_string(np, "compatible", prop, compat) {
613 parser = mtd_part_get_compatible_parser(compat);
614 if (!parser)
615 continue;
616 ret = mtd_part_do_parse(parser, master, pparts, NULL);
617 if (ret > 0) {
618 of_platform_populate(np, NULL, NULL, dev);
619 of_node_put(np);
620 return ret;
621 }
622 mtd_part_parser_put(parser);
623 if (ret < 0 && !err)
624 err = ret;
625 }
626 of_platform_populate(np, NULL, NULL, dev);
627 of_node_put(np);
628
629 /*
630 * For backward compatibility we have to try the "fixed-partitions"
631 * parser. It supports old DT format with partitions specified as a
632 * direct subnodes of a flash device DT node without any compatibility
633 * specified we could match.
634 */
635 parser = mtd_part_parser_get(fixed);
636 if (!parser && !request_module("%s", fixed))
637 parser = mtd_part_parser_get(fixed);
638 if (parser) {
639 ret = mtd_part_do_parse(parser, master, pparts, NULL);
640 if (ret > 0)
641 return ret;
642 mtd_part_parser_put(parser);
643 if (ret < 0 && !err)
644 err = ret;
645 }
646
647 return err;
648}
649
650/**
651 * parse_mtd_partitions - parse and register MTD partitions
652 *
653 * @master: the master partition (describes whole MTD device)
654 * @types: names of partition parsers to try or %NULL
655 * @data: MTD partition parser-specific data
656 *
657 * This function tries to find & register partitions on MTD device @master. It
658 * uses MTD partition parsers, specified in @types. However, if @types is %NULL,
659 * then the default list of parsers is used. The default list contains only the
660 * "cmdlinepart" and "ofpart" parsers ATM.
661 * Note: If there are more then one parser in @types, the kernel only takes the
662 * partitions parsed out by the first parser.
663 *
664 * This function may return:
665 * o a negative error code in case of failure
666 * o number of found partitions otherwise
667 */
668int parse_mtd_partitions(struct mtd_info *master, const char *const *types,
669 struct mtd_part_parser_data *data)
670{
671 struct mtd_partitions pparts = { };
672 struct mtd_part_parser *parser;
673 int ret, err = 0;
674
675 if (!types)
676 types = mtd_is_partition(master) ? default_subpartition_types :
677 default_mtd_part_types;
678
679 for ( ; *types; types++) {
680 /*
681 * ofpart is a special type that means OF partitioning info
682 * should be used. It requires a bit different logic so it is
683 * handled in a separated function.
684 */
685 if (!strcmp(*types, "ofpart")) {
686 ret = mtd_part_of_parse(master, &pparts);
687 } else {
688 pr_debug("%s: parsing partitions %s\n", master->name,
689 *types);
690 parser = mtd_part_parser_get(*types);
691 if (!parser && !request_module("%s", *types))
692 parser = mtd_part_parser_get(*types);
693 pr_debug("%s: got parser %s\n", master->name,
694 parser ? parser->name : NULL);
695 if (!parser)
696 continue;
697 ret = mtd_part_do_parse(parser, master, &pparts, data);
698 if (ret <= 0)
699 mtd_part_parser_put(parser);
700 }
701 /* Found partitions! */
702 if (ret > 0) {
703 err = add_mtd_partitions(master, pparts.parts,
704 pparts.nr_parts);
705 mtd_part_parser_cleanup(&pparts);
706 return err ? err : pparts.nr_parts;
707 }
708 /*
709 * Stash the first error we see; only report it if no parser
710 * succeeds
711 */
712 if (ret < 0 && !err)
713 err = ret;
714 }
715 return err;
716}
717
718void mtd_part_parser_cleanup(struct mtd_partitions *parts)
719{
720 const struct mtd_part_parser *parser;
721
722 if (!parts)
723 return;
724
725 parser = parts->parser;
726 if (parser) {
727 if (parser->cleanup)
728 parser->cleanup(parts->parts, parts->nr_parts);
729
730 mtd_part_parser_put(parser);
731 }
732}
733
734/* Returns the size of the entire flash chip */
735uint64_t mtd_get_device_size(const struct mtd_info *mtd)
736{
737 struct mtd_info *master = mtd_get_master((struct mtd_info *)mtd);
738
739 return master->size;
740}
741EXPORT_SYMBOL_GPL(mtd_get_device_size);
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 */
37static LIST_HEAD(mtd_partitions);
38static DEFINE_MUTEX(mtd_partitions_mutex);
39
40/* Our partition node structure */
41struct 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
60static 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
84static 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
96static 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
103static 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
115static 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
153static 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
161static 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
168static 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
176static 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
183static 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
197static 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
211static 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
226static 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
234static 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
241static 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
251static 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
269void 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}
281EXPORT_SYMBOL_GPL(mtd_erase_callback);
282
283static 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
291static 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
299static 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
307static void part_sync(struct mtd_info *mtd)
308{
309 struct mtd_part *part = PART(mtd);
310 part->master->sync(part->master);
311}
312
313static int part_suspend(struct mtd_info *mtd)
314{
315 struct mtd_part *part = PART(mtd);
316 return part->master->suspend(part->master);
317}
318
319static void part_resume(struct mtd_info *mtd)
320{
321 struct mtd_part *part = PART(mtd);
322 part->master->resume(part->master);
323}
324
325static 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
334static 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
350static 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
361int 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
382static 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
556out_register:
557 return slave;
558}
559
560int 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;
610err_inv:
611 mutex_unlock(&mtd_partitions_mutex);
612 free_partition(new);
613 return -EINVAL;
614}
615EXPORT_SYMBOL_GPL(mtd_add_partition);
616
617int 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}
638EXPORT_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
649int 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
676static DEFINE_SPINLOCK(part_parser_lock);
677static LIST_HEAD(part_parsers);
678
679static 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
696int 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}
704EXPORT_SYMBOL_GPL(register_mtd_parser);
705
706int 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}
713EXPORT_SYMBOL_GPL(deregister_mtd_parser);
714
715int 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}
736EXPORT_SYMBOL_GPL(parse_mtd_partitions);
737
738int 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}
753EXPORT_SYMBOL_GPL(mtd_is_partition);