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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 <[email protected]>
6 * Copyright © 2002 Thomas Gleixner <[email protected]>
7 * Copyright © 2000-2010 David Woodhouse <[email protected]>
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#include <linux/mtd/concat.h>
22
23#include "mtdcore.h"
24
25/*
26 * MTD methods which simply translate the effective address and pass through
27 * to the _real_ device.
28 */
29
30static inline void free_partition(struct mtd_info *mtd)
31{
32 kfree(mtd->name);
33 kfree(mtd);
34}
35
36void release_mtd_partition(struct mtd_info *mtd)
37{
38 WARN_ON(!list_empty(&mtd->part.node));
39 free_partition(mtd);
40}
41
42static struct mtd_info *allocate_partition(struct mtd_info *parent,
43 const struct mtd_partition *part,
44 int partno, uint64_t cur_offset)
45{
46 struct mtd_info *master = mtd_get_master(parent);
47 int wr_alignment = (parent->flags & MTD_NO_ERASE) ?
48 master->writesize : master->erasesize;
49 u64 parent_size = mtd_is_partition(parent) ?
50 parent->part.size : parent->size;
51 struct mtd_info *child;
52 u32 remainder;
53 char *name;
54 u64 tmp;
55
56 /* allocate the partition structure */
57 child = kzalloc_obj(*child);
58 name = kstrdup(part->name, GFP_KERNEL);
59 if (!name || !child) {
60 printk(KERN_ERR"memory allocation error while creating partitions for \"%s\"\n",
61 parent->name);
62 kfree(name);
63 kfree(child);
64 return ERR_PTR(-ENOMEM);
65 }
66
67 /* set up the MTD object for this partition */
68 child->type = parent->type;
69 child->part.flags = parent->flags & ~part->mask_flags;
70 child->part.flags |= part->add_flags;
71 child->flags = child->part.flags;
72 child->part.size = part->size;
73 child->writesize = parent->writesize;
74 child->writebufsize = parent->writebufsize;
75 child->oobsize = parent->oobsize;
76 child->oobavail = parent->oobavail;
77 child->subpage_sft = parent->subpage_sft;
78
79 child->name = name;
80 child->owner = parent->owner;
81
82 /* NOTE: Historically, we didn't arrange MTDs as a tree out of
83 * concern for showing the same data in multiple partitions.
84 * However, it is very useful to have the master node present,
85 * so the MTD_PARTITIONED_MASTER option allows that. The master
86 * will have device nodes etc only if this is set, so make the
87 * parent conditional on that option. Note, this is a way to
88 * distinguish between the parent and its partitions in sysfs.
89 */
90 child->dev.parent = IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER) || mtd_is_partition(parent) ?
91 &parent->dev : parent->dev.parent;
92 child->dev.of_node = part->of_node;
93 child->parent = parent;
94 child->part.offset = part->offset;
95 INIT_LIST_HEAD(&child->partitions);
96
97 if (child->part.offset == MTDPART_OFS_APPEND)
98 child->part.offset = cur_offset;
99 if (child->part.offset == MTDPART_OFS_NXTBLK) {
100 tmp = cur_offset;
101 child->part.offset = cur_offset;
102 remainder = do_div(tmp, wr_alignment);
103 if (remainder) {
104 child->part.offset += wr_alignment - remainder;
105 printk(KERN_NOTICE "Moving partition %d: "
106 "0x%012llx -> 0x%012llx\n", partno,
107 (unsigned long long)cur_offset,
108 child->part.offset);
109 }
110 }
111 if (child->part.offset == MTDPART_OFS_RETAIN) {
112 child->part.offset = cur_offset;
113 if (parent_size - child->part.offset >= child->part.size) {
114 child->part.size = parent_size - child->part.offset -
115 child->part.size;
116 } else {
117 printk(KERN_ERR "mtd partition \"%s\" doesn't have enough space: %#llx < %#llx, disabled\n",
118 part->name, parent_size - child->part.offset,
119 child->part.size);
120 /* register to preserve ordering */
121 child->part.offset = 0;
122 child->part.size = 0;
123 child->erasesize = parent->erasesize;
124 goto out_register;
125 }
126 }
127 if (child->part.size == MTDPART_SIZ_FULL)
128 child->part.size = parent_size - child->part.offset;
129
130 printk(KERN_NOTICE "0x%012llx-0x%012llx : \"%s\"\n",
131 child->part.offset, child->part.offset + child->part.size,
132 child->name);
133
134 /* let's do some sanity checks */
135 if (child->part.offset >= parent_size) {
136 /* let's register it anyway to preserve ordering */
137 child->part.offset = 0;
138 child->part.size = 0;
139
140 /* Initialize ->erasesize to make add_mtd_device() happy. */
141 child->erasesize = parent->erasesize;
142 printk(KERN_ERR"mtd: partition \"%s\" is out of reach -- disabled\n",
143 part->name);
144 goto out_register;
145 }
146 if (child->part.offset + child->part.size > parent->size) {
147 child->part.size = parent_size - child->part.offset;
148 printk(KERN_WARNING"mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#llx\n",
149 part->name, parent->name, child->part.size);
150 }
151
152 if (parent->numeraseregions > 1) {
153 /* Deal with variable erase size stuff */
154 int i, max = parent->numeraseregions;
155 u64 end = child->part.offset + child->part.size;
156 struct mtd_erase_region_info *regions = parent->eraseregions;
157
158 /* Find the first erase regions which is part of this
159 * partition. */
160 for (i = 0; i < max && regions[i].offset <= child->part.offset;
161 i++)
162 ;
163 /* The loop searched for the region _behind_ the first one */
164 if (i > 0)
165 i--;
166
167 /* Pick biggest erasesize */
168 for (; i < max && regions[i].offset < end; i++) {
169 if (child->erasesize < regions[i].erasesize)
170 child->erasesize = regions[i].erasesize;
171 }
172 BUG_ON(child->erasesize == 0);
173 } else {
174 /* Single erase size */
175 child->erasesize = master->erasesize;
176 }
177
178 /*
179 * Child erasesize might differ from the parent one if the parent
180 * exposes several regions with different erasesize. Adjust
181 * wr_alignment accordingly.
182 */
183 if (!(child->flags & MTD_NO_ERASE))
184 wr_alignment = child->erasesize;
185
186 tmp = mtd_get_master_ofs(child, 0);
187 remainder = do_div(tmp, wr_alignment);
188 if ((child->flags & MTD_WRITEABLE) && remainder) {
189 /* Doesn't start on a boundary of major erase size */
190 /* FIXME: Let it be writable if it is on a boundary of
191 * _minor_ erase size though */
192 child->flags &= ~MTD_WRITEABLE;
193 printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase/write block boundary -- force read-only\n",
194 part->name);
195 }
196
197 tmp = mtd_get_master_ofs(child, 0) + child->part.size;
198 remainder = do_div(tmp, wr_alignment);
199 if ((child->flags & MTD_WRITEABLE) && remainder) {
200 child->flags &= ~MTD_WRITEABLE;
201 printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase/write block -- force read-only\n",
202 part->name);
203 }
204
205 child->size = child->part.size;
206 child->ecc_step_size = parent->ecc_step_size;
207 child->ecc_strength = parent->ecc_strength;
208 child->bitflip_threshold = parent->bitflip_threshold;
209
210 if (master->_block_isbad) {
211 uint64_t offs = 0;
212
213 while (offs < child->part.size) {
214 if (mtd_block_isreserved(child, offs))
215 child->ecc_stats.bbtblocks++;
216 else if (mtd_block_isbad(child, offs))
217 child->ecc_stats.badblocks++;
218 offs += child->erasesize;
219 }
220 }
221
222out_register:
223 return child;
224}
225
226static ssize_t offset_show(struct device *dev,
227 struct device_attribute *attr, char *buf)
228{
229 struct mtd_info *mtd = dev_get_drvdata(dev);
230
231 return sysfs_emit(buf, "%lld\n", mtd->part.offset);
232}
233static DEVICE_ATTR_RO(offset); /* mtd partition offset */
234
235static const struct attribute *mtd_partition_attrs[] = {
236 &dev_attr_offset.attr,
237 NULL
238};
239
240static int mtd_add_partition_attrs(struct mtd_info *new)
241{
242 int ret = sysfs_create_files(&new->dev.kobj, mtd_partition_attrs);
243 if (ret)
244 printk(KERN_WARNING
245 "mtd: failed to create partition attrs, err=%d\n", ret);
246 return ret;
247}
248
249int mtd_add_partition(struct mtd_info *parent, const char *name,
250 long long offset, long long length)
251{
252 struct mtd_info *master = mtd_get_master(parent);
253 u64 parent_size = mtd_is_partition(parent) ?
254 parent->part.size : parent->size;
255 struct mtd_partition part;
256 struct mtd_info *child;
257 int ret = 0;
258
259 /* the direct offset is expected */
260 if (offset == MTDPART_OFS_APPEND ||
261 offset == MTDPART_OFS_NXTBLK ||
262 offset == MTDPART_OFS_RETAIN)
263 return -EINVAL;
264
265 if (length == MTDPART_SIZ_FULL)
266 length = parent_size - offset;
267
268 if (length <= 0)
269 return -EINVAL;
270
271 if (offset < 0 || offset >= (long long)parent_size)
272 return -EINVAL;
273
274 if ((u64)offset + (u64)length > parent_size)
275 return -EINVAL;
276 memset(&part, 0, sizeof(part));
277 part.name = name;
278 part.size = length;
279 part.offset = offset;
280
281 child = allocate_partition(parent, &part, -1, offset);
282 if (IS_ERR(child))
283 return PTR_ERR(child);
284
285 mutex_lock(&master->master.partitions_lock);
286 list_add_tail(&child->part.node, &parent->partitions);
287 mutex_unlock(&master->master.partitions_lock);
288
289 ret = add_mtd_device(child);
290 if (ret)
291 goto err_remove_part;
292
293 mtd_add_partition_attrs(child);
294
295 return 0;
296
297err_remove_part:
298 mutex_lock(&master->master.partitions_lock);
299 list_del(&child->part.node);
300 mutex_unlock(&master->master.partitions_lock);
301
302 free_partition(child);
303
304 return ret;
305}
306EXPORT_SYMBOL_GPL(mtd_add_partition);
307
308/**
309 * __mtd_del_partition - delete MTD partition
310 *
311 * @mtd: MTD structure to be deleted
312 *
313 * This function must be called with the partitions mutex locked.
314 */
315static int __mtd_del_partition(struct mtd_info *mtd)
316{
317 struct mtd_info *child, *next;
318 int err;
319
320 list_for_each_entry_safe(child, next, &mtd->partitions, part.node) {
321 err = __mtd_del_partition(child);
322 if (err)
323 return err;
324 }
325
326 sysfs_remove_files(&mtd->dev.kobj, mtd_partition_attrs);
327
328 list_del_init(&mtd->part.node);
329 err = del_mtd_device(mtd);
330 if (err)
331 return err;
332
333 return 0;
334}
335
336/*
337 * This function unregisters and destroy all slave MTD objects which are
338 * attached to the given MTD object, recursively.
339 */
340static int __del_mtd_partitions(struct mtd_info *mtd)
341{
342 struct mtd_info *child, *next;
343 int ret, err = 0;
344
345 list_for_each_entry_safe(child, next, &mtd->partitions, part.node) {
346 if (mtd_has_partitions(child))
347 __del_mtd_partitions(child);
348
349 pr_info("Deleting %s MTD partition\n", child->name);
350 list_del_init(&child->part.node);
351 ret = del_mtd_device(child);
352 if (ret < 0) {
353 pr_err("Error when deleting partition \"%s\" (%d)\n",
354 child->name, ret);
355 err = ret;
356 continue;
357 }
358 }
359
360 return err;
361}
362
363int del_mtd_partitions(struct mtd_info *mtd)
364{
365 struct mtd_info *master = mtd_get_master(mtd);
366 int ret;
367
368 pr_info("Deleting MTD partitions on \"%s\":\n", mtd->name);
369
370 mutex_lock(&master->master.partitions_lock);
371 ret = __del_mtd_partitions(mtd);
372 mutex_unlock(&master->master.partitions_lock);
373
374 return ret;
375}
376
377int mtd_del_partition(struct mtd_info *mtd, int partno)
378{
379 struct mtd_info *child, *master = mtd_get_master(mtd);
380 int ret = -EINVAL;
381
382 mutex_lock(&master->master.partitions_lock);
383 list_for_each_entry(child, &mtd->partitions, part.node) {
384 if (child->index == partno) {
385 ret = __mtd_del_partition(child);
386 break;
387 }
388 }
389 mutex_unlock(&master->master.partitions_lock);
390
391 return ret;
392}
393EXPORT_SYMBOL_GPL(mtd_del_partition);
394
395/*
396 * This function, given a parent MTD object and a partition table, creates
397 * and registers the child MTD objects which are bound to the parent according
398 * to the partition definitions.
399 *
400 * For historical reasons, this function's caller only registers the parent
401 * if the MTD_PARTITIONED_MASTER config option is set.
402 */
403
404int add_mtd_partitions(struct mtd_info *parent,
405 const struct mtd_partition *parts,
406 int nbparts)
407{
408 struct mtd_info *child, *master = mtd_get_master(parent);
409 uint64_t cur_offset = 0;
410 int i, ret;
411
412 printk(KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n",
413 nbparts, parent->name);
414
415 for (i = 0; i < nbparts; i++) {
416 child = allocate_partition(parent, parts + i, i, cur_offset);
417 if (IS_ERR(child)) {
418 ret = PTR_ERR(child);
419 goto err_del_partitions;
420 }
421
422 if (IS_REACHABLE(CONFIG_MTD_VIRT_CONCAT)) {
423 if (mtd_virt_concat_add(child))
424 continue;
425 }
426
427 mutex_lock(&master->master.partitions_lock);
428 list_add_tail(&child->part.node, &parent->partitions);
429 mutex_unlock(&master->master.partitions_lock);
430
431 ret = add_mtd_device(child);
432 if (ret) {
433 mutex_lock(&master->master.partitions_lock);
434 list_del(&child->part.node);
435 mutex_unlock(&master->master.partitions_lock);
436
437 free_partition(child);
438 goto err_del_partitions;
439 }
440
441 mtd_add_partition_attrs(child);
442
443 /* Look for subpartitions (skip if no maching parser found) */
444 ret = parse_mtd_partitions(child, parts[i].types, NULL);
445 if (ret < 0 && ret == -ENOENT) {
446 pr_debug("Skip parsing subpartitions: %d\n", ret);
447 continue;
448 } else if (ret < 0) {
449 pr_err("Failed to parse subpartitions: %d\n", ret);
450 goto err_del_partitions;
451 }
452
453 cur_offset = child->part.offset + child->part.size;
454 }
455
456 return 0;
457
458err_del_partitions:
459 del_mtd_partitions(master);
460
461 return ret;
462}
463
464static DEFINE_SPINLOCK(part_parser_lock);
465static LIST_HEAD(part_parsers);
466
467static struct mtd_part_parser *mtd_part_parser_get(const char *name)
468{
469 struct mtd_part_parser *p, *ret = NULL;
470
471 spin_lock(&part_parser_lock);
472
473 list_for_each_entry(p, &part_parsers, list)
474 if (!strcmp(p->name, name) && try_module_get(p->owner)) {
475 ret = p;
476 break;
477 }
478
479 spin_unlock(&part_parser_lock);
480
481 return ret;
482}
483
484static inline void mtd_part_parser_put(const struct mtd_part_parser *p)
485{
486 module_put(p->owner);
487}
488
489/*
490 * Many partition parsers just expected the core to kfree() all their data in
491 * one chunk. Do that by default.
492 */
493static void mtd_part_parser_cleanup_default(const struct mtd_partition *pparts,
494 int nr_parts)
495{
496 kfree(pparts);
497}
498
499int __register_mtd_parser(struct mtd_part_parser *p, struct module *owner)
500{
501 p->owner = owner;
502
503 if (!p->cleanup)
504 p->cleanup = &mtd_part_parser_cleanup_default;
505
506 spin_lock(&part_parser_lock);
507 list_add(&p->list, &part_parsers);
508 spin_unlock(&part_parser_lock);
509
510 return 0;
511}
512EXPORT_SYMBOL_GPL(__register_mtd_parser);
513
514void deregister_mtd_parser(struct mtd_part_parser *p)
515{
516 spin_lock(&part_parser_lock);
517 list_del(&p->list);
518 spin_unlock(&part_parser_lock);
519}
520EXPORT_SYMBOL_GPL(deregister_mtd_parser);
521
522/*
523 * Do not forget to update 'parse_mtd_partitions()' kerneldoc comment if you
524 * are changing this array!
525 */
526static const char * const default_mtd_part_types[] = {
527 "cmdlinepart",
528 "ofpart",
529 NULL
530};
531
532/* Check DT only when looking for subpartitions. */
533static const char * const default_subpartition_types[] = {
534 "ofpart",
535 NULL
536};
537
538static int mtd_part_do_parse(struct mtd_part_parser *parser,
539 struct mtd_info *master,
540 struct mtd_partitions *pparts,
541 struct mtd_part_parser_data *data)
542{
543 int ret;
544
545 ret = (*parser->parse_fn)(master, &pparts->parts, data);
546 pr_debug("%s: parser %s: %i\n", master->name, parser->name, ret);
547 if (ret <= 0)
548 return ret;
549
550 pr_notice("%d %s partitions found on MTD device %s\n", ret,
551 parser->name, master->name);
552
553 pparts->nr_parts = ret;
554 pparts->parser = parser;
555
556 return ret;
557}
558
559/**
560 * mtd_part_get_compatible_parser - find MTD parser by a compatible string
561 *
562 * @compat: compatible string describing partitions in a device tree
563 *
564 * MTD parsers can specify supported partitions by providing a table of
565 * compatibility strings. This function finds a parser that advertises support
566 * for a passed value of "compatible".
567 */
568static struct mtd_part_parser *mtd_part_get_compatible_parser(const char *compat)
569{
570 struct mtd_part_parser *p, *ret = NULL;
571
572 spin_lock(&part_parser_lock);
573
574 list_for_each_entry(p, &part_parsers, list) {
575 const struct of_device_id *matches;
576
577 matches = p->of_match_table;
578 if (!matches)
579 continue;
580
581 for (; matches->compatible[0]; matches++) {
582 if (!strcmp(matches->compatible, compat) &&
583 try_module_get(p->owner)) {
584 ret = p;
585 break;
586 }
587 }
588
589 if (ret)
590 break;
591 }
592
593 spin_unlock(&part_parser_lock);
594
595 return ret;
596}
597
598static int mtd_part_of_parse(struct mtd_info *master,
599 struct mtd_partitions *pparts)
600{
601 struct mtd_part_parser *parser;
602 struct device_node *np;
603 struct device_node *child;
604 struct property *prop;
605 struct device *dev;
606 const char *compat;
607 const char *fixed = "fixed-partitions";
608 int ret, err = 0;
609
610 dev = &master->dev;
611 /* Use parent device (controller) if the top level MTD is not registered */
612 if (!IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER) && !mtd_is_partition(master))
613 dev = master->dev.parent;
614
615 np = mtd_get_of_node(master);
616 if (mtd_is_partition(master))
617 of_node_get(np);
618 else
619 np = of_get_child_by_name(np, "partitions");
620
621 /*
622 * Don't create devices that are added to a bus but will never get
623 * probed. That'll cause fw_devlink to block probing of consumers of
624 * this partition until the partition device is probed.
625 */
626 for_each_child_of_node(np, child)
627 if (of_device_is_compatible(child, "nvmem-cells"))
628 of_node_set_flag(child, OF_POPULATED);
629
630 of_property_for_each_string(np, "compatible", prop, compat) {
631 parser = mtd_part_get_compatible_parser(compat);
632 if (!parser)
633 continue;
634 ret = mtd_part_do_parse(parser, master, pparts, NULL);
635 if (ret > 0) {
636 of_platform_populate(np, NULL, NULL, dev);
637 of_node_put(np);
638 return ret;
639 }
640 mtd_part_parser_put(parser);
641 if (ret < 0 && !err)
642 err = ret;
643 }
644 of_platform_populate(np, NULL, NULL, dev);
645 of_node_put(np);
646
647 /*
648 * For backward compatibility we have to try the "fixed-partitions"
649 * parser. It supports old DT format with partitions specified as a
650 * direct subnodes of a flash device DT node without any compatibility
651 * specified we could match.
652 */
653 parser = mtd_part_parser_get(fixed);
654 if (!parser && !request_module("%s", fixed))
655 parser = mtd_part_parser_get(fixed);
656 if (parser) {
657 ret = mtd_part_do_parse(parser, master, pparts, NULL);
658 if (ret > 0)
659 return ret;
660 mtd_part_parser_put(parser);
661 if (ret < 0 && !err)
662 err = ret;
663 }
664
665 return err;
666}
667
668/**
669 * parse_mtd_partitions - parse and register MTD partitions
670 *
671 * @master: the master partition (describes whole MTD device)
672 * @types: names of partition parsers to try or %NULL
673 * @data: MTD partition parser-specific data
674 *
675 * This function tries to find & register partitions on MTD device @master. It
676 * uses MTD partition parsers, specified in @types. However, if @types is %NULL,
677 * then the default list of parsers is used. The default list contains only the
678 * "cmdlinepart" and "ofpart" parsers ATM.
679 * Note: If there are more then one parser in @types, the kernel only takes the
680 * partitions parsed out by the first parser.
681 *
682 * This function may return:
683 * o a negative error code in case of failure
684 * o number of found partitions otherwise
685 */
686int parse_mtd_partitions(struct mtd_info *master, const char *const *types,
687 struct mtd_part_parser_data *data)
688{
689 struct mtd_partitions pparts = { };
690 struct mtd_part_parser *parser;
691 int ret, err = 0;
692
693 if (!types)
694 types = mtd_is_partition(master) ? default_subpartition_types :
695 default_mtd_part_types;
696
697 for ( ; *types; types++) {
698 /*
699 * ofpart is a special type that means OF partitioning info
700 * should be used. It requires a bit different logic so it is
701 * handled in a separated function.
702 */
703 if (!strcmp(*types, "ofpart")) {
704 ret = mtd_part_of_parse(master, &pparts);
705 } else {
706 pr_debug("%s: parsing partitions %s\n", master->name,
707 *types);
708 parser = mtd_part_parser_get(*types);
709 if (!parser && !request_module("%s", *types))
710 parser = mtd_part_parser_get(*types);
711 if (!parser)
712 continue;
713 pr_debug("%s: got parser %s\n", master->name, parser->name);
714 ret = mtd_part_do_parse(parser, master, &pparts, data);
715 if (ret <= 0)
716 mtd_part_parser_put(parser);
717 }
718 /* Found partitions! */
719 if (ret > 0) {
720 err = add_mtd_partitions(master, pparts.parts,
721 pparts.nr_parts);
722 mtd_part_parser_cleanup(&pparts);
723 return err ? err : pparts.nr_parts;
724 }
725 /*
726 * Stash the first error we see; only report it if no parser
727 * succeeds
728 */
729 if (ret < 0 && !err)
730 err = ret;
731 }
732 return err;
733}
734
735void mtd_part_parser_cleanup(struct mtd_partitions *parts)
736{
737 const struct mtd_part_parser *parser;
738
739 if (!parts)
740 return;
741
742 parser = parts->parser;
743 if (parser) {
744 if (parser->cleanup)
745 parser->cleanup(parts->parts, parts->nr_parts);
746
747 mtd_part_parser_put(parser);
748 }
749}
750
751/* Returns the size of the entire flash chip */
752uint64_t mtd_get_device_size(const struct mtd_info *mtd)
753{
754 struct mtd_info *master = mtd_get_master((struct mtd_info *)mtd);
755
756 return master->size;
757}
758EXPORT_SYMBOL_GPL(mtd_get_device_size);