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