2 * Simple MTD partitioning layer
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>
8 * SPDX-License-Identifier: GPL-2.0+
13 #include <linux/module.h>
14 #include <linux/types.h>
15 #include <linux/kernel.h>
16 #include <linux/slab.h>
17 #include <linux/list.h>
18 #include <linux/kmod.h>
23 #include <linux/errno.h>
24 #include <linux/compat.h>
25 #include <ubi_uboot.h>
27 #include <linux/mtd/mtd.h>
28 #include <linux/mtd/partitions.h>
29 #include <linux/err.h>
33 /* Our partition linked list */
34 static LIST_HEAD(mtd_partitions);
36 static DEFINE_MUTEX(mtd_partitions_mutex);
38 DEFINE_MUTEX(mtd_partitions_mutex);
41 /* Our partition node structure */
44 struct mtd_info *master;
46 struct list_head list;
50 * Given a pointer to the MTD object in the mtd_part structure, we can retrieve
51 * the pointer to that structure with this macro.
53 #define PART(x) ((struct mtd_part *)(x))
60 * kstrdup - allocate space for and copy an existing string
61 * @s: the string to duplicate
62 * @gfp: the GFP mask used in the kmalloc() call when allocating memory
64 char *kstrdup(const char *s, gfp_t gfp)
73 buf = kmalloc(len, gfp);
81 * MTD methods which simply translate the effective address and pass through
82 * to the _real_ device.
85 static int part_read(struct mtd_info *mtd, loff_t from, size_t len,
86 size_t *retlen, u_char *buf)
88 struct mtd_part *part = PART(mtd);
89 struct mtd_ecc_stats stats;
92 stats = part->master->ecc_stats;
93 res = part->master->_read(part->master, from + part->offset, len,
95 if (unlikely(mtd_is_eccerr(res)))
96 mtd->ecc_stats.failed +=
97 part->master->ecc_stats.failed - stats.failed;
99 mtd->ecc_stats.corrected +=
100 part->master->ecc_stats.corrected - stats.corrected;
105 static int part_point(struct mtd_info *mtd, loff_t from, size_t len,
106 size_t *retlen, void **virt, resource_size_t *phys)
108 struct mtd_part *part = PART(mtd);
110 return part->master->_point(part->master, from + part->offset, len,
114 static int part_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
116 struct mtd_part *part = PART(mtd);
118 return part->master->_unpoint(part->master, from + part->offset, len);
122 static unsigned long part_get_unmapped_area(struct mtd_info *mtd,
124 unsigned long offset,
127 struct mtd_part *part = PART(mtd);
129 offset += part->offset;
130 return part->master->_get_unmapped_area(part->master, len, offset,
134 static int part_read_oob(struct mtd_info *mtd, loff_t from,
135 struct mtd_oob_ops *ops)
137 struct mtd_part *part = PART(mtd);
140 if (from >= mtd->size)
142 if (ops->datbuf && from + ops->len > mtd->size)
146 * If OOB is also requested, make sure that we do not read past the end
152 if (ops->mode == MTD_OPS_AUTO_OOB)
156 pages = mtd_div_by_ws(mtd->size, mtd);
157 pages -= mtd_div_by_ws(from, mtd);
158 if (ops->ooboffs + ops->ooblen > pages * len)
162 res = part->master->_read_oob(part->master, from + part->offset, ops);
164 if (mtd_is_bitflip(res))
165 mtd->ecc_stats.corrected++;
166 if (mtd_is_eccerr(res))
167 mtd->ecc_stats.failed++;
172 static int part_read_user_prot_reg(struct mtd_info *mtd, loff_t from,
173 size_t len, size_t *retlen, u_char *buf)
175 struct mtd_part *part = PART(mtd);
176 return part->master->_read_user_prot_reg(part->master, from, len,
180 static int part_get_user_prot_info(struct mtd_info *mtd, size_t len,
181 size_t *retlen, struct otp_info *buf)
183 struct mtd_part *part = PART(mtd);
184 return part->master->_get_user_prot_info(part->master, len, retlen,
188 static int part_read_fact_prot_reg(struct mtd_info *mtd, loff_t from,
189 size_t len, size_t *retlen, u_char *buf)
191 struct mtd_part *part = PART(mtd);
192 return part->master->_read_fact_prot_reg(part->master, from, len,
196 static int part_get_fact_prot_info(struct mtd_info *mtd, size_t len,
197 size_t *retlen, struct otp_info *buf)
199 struct mtd_part *part = PART(mtd);
200 return part->master->_get_fact_prot_info(part->master, len, retlen,
204 static int part_write(struct mtd_info *mtd, loff_t to, size_t len,
205 size_t *retlen, const u_char *buf)
207 struct mtd_part *part = PART(mtd);
208 return part->master->_write(part->master, to + part->offset, len,
212 static int part_panic_write(struct mtd_info *mtd, loff_t to, size_t len,
213 size_t *retlen, const u_char *buf)
215 struct mtd_part *part = PART(mtd);
216 return part->master->_panic_write(part->master, to + part->offset, len,
220 static int part_write_oob(struct mtd_info *mtd, loff_t to,
221 struct mtd_oob_ops *ops)
223 struct mtd_part *part = PART(mtd);
227 if (ops->datbuf && to + ops->len > mtd->size)
229 return part->master->_write_oob(part->master, to + part->offset, ops);
232 static int part_write_user_prot_reg(struct mtd_info *mtd, loff_t from,
233 size_t len, size_t *retlen, u_char *buf)
235 struct mtd_part *part = PART(mtd);
236 return part->master->_write_user_prot_reg(part->master, from, len,
240 static int part_lock_user_prot_reg(struct mtd_info *mtd, loff_t from,
243 struct mtd_part *part = PART(mtd);
244 return part->master->_lock_user_prot_reg(part->master, from, len);
248 static int part_writev(struct mtd_info *mtd, const struct kvec *vecs,
249 unsigned long count, loff_t to, size_t *retlen)
251 struct mtd_part *part = PART(mtd);
252 return part->master->_writev(part->master, vecs, count,
253 to + part->offset, retlen);
257 static int part_erase(struct mtd_info *mtd, struct erase_info *instr)
259 struct mtd_part *part = PART(mtd);
262 instr->addr += part->offset;
263 ret = part->master->_erase(part->master, instr);
265 if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
266 instr->fail_addr -= part->offset;
267 instr->addr -= part->offset;
272 void mtd_erase_callback(struct erase_info *instr)
274 if (instr->mtd->_erase == part_erase) {
275 struct mtd_part *part = PART(instr->mtd);
277 if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
278 instr->fail_addr -= part->offset;
279 instr->addr -= part->offset;
282 instr->callback(instr);
284 EXPORT_SYMBOL_GPL(mtd_erase_callback);
286 static int part_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
288 struct mtd_part *part = PART(mtd);
289 return part->master->_lock(part->master, ofs + part->offset, len);
292 static int part_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
294 struct mtd_part *part = PART(mtd);
295 return part->master->_unlock(part->master, ofs + part->offset, len);
298 static int part_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
300 struct mtd_part *part = PART(mtd);
301 return part->master->_is_locked(part->master, ofs + part->offset, len);
304 static void part_sync(struct mtd_info *mtd)
306 struct mtd_part *part = PART(mtd);
307 part->master->_sync(part->master);
311 static int part_suspend(struct mtd_info *mtd)
313 struct mtd_part *part = PART(mtd);
314 return part->master->_suspend(part->master);
317 static void part_resume(struct mtd_info *mtd)
319 struct mtd_part *part = PART(mtd);
320 part->master->_resume(part->master);
324 static int part_block_isreserved(struct mtd_info *mtd, loff_t ofs)
326 struct mtd_part *part = PART(mtd);
328 return part->master->_block_isreserved(part->master, ofs);
331 static int part_block_isbad(struct mtd_info *mtd, loff_t ofs)
333 struct mtd_part *part = PART(mtd);
335 return part->master->_block_isbad(part->master, ofs);
338 static int part_block_markbad(struct mtd_info *mtd, loff_t ofs)
340 struct mtd_part *part = PART(mtd);
344 res = part->master->_block_markbad(part->master, ofs);
346 mtd->ecc_stats.badblocks++;
350 static inline void free_partition(struct mtd_part *p)
357 * This function unregisters and destroy all slave MTD objects which are
358 * attached to the given master MTD object.
361 int del_mtd_partitions(struct mtd_info *master)
363 struct mtd_part *slave, *next;
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);
374 list_del(&slave->list);
375 free_partition(slave);
377 mutex_unlock(&mtd_partitions_mutex);
382 static struct mtd_part *allocate_partition(struct mtd_info *master,
383 const struct mtd_partition *part, int partno,
386 struct mtd_part *slave;
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",
397 return ERR_PTR(-ENOMEM);
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;
410 slave->mtd.name = name;
411 slave->mtd.owner = master->owner;
413 slave->mtd.backing_dev_info = master->backing_dev_info;
415 /* NOTE: we don't arrange MTDs as a tree; it'd be error-prone
416 * to have the same data be in two different partitions.
418 slave->mtd.dev.parent = master->dev.parent;
421 slave->mtd._read = part_read;
422 slave->mtd._write = part_write;
424 if (master->_panic_write)
425 slave->mtd._panic_write = part_panic_write;
428 if (master->_point && master->_unpoint) {
429 slave->mtd._point = part_point;
430 slave->mtd._unpoint = part_unpoint;
434 if (master->_get_unmapped_area)
435 slave->mtd._get_unmapped_area = part_get_unmapped_area;
436 if (master->_read_oob)
437 slave->mtd._read_oob = part_read_oob;
438 if (master->_write_oob)
439 slave->mtd._write_oob = part_write_oob;
440 if (master->_read_user_prot_reg)
441 slave->mtd._read_user_prot_reg = part_read_user_prot_reg;
442 if (master->_read_fact_prot_reg)
443 slave->mtd._read_fact_prot_reg = part_read_fact_prot_reg;
444 if (master->_write_user_prot_reg)
445 slave->mtd._write_user_prot_reg = part_write_user_prot_reg;
446 if (master->_lock_user_prot_reg)
447 slave->mtd._lock_user_prot_reg = part_lock_user_prot_reg;
448 if (master->_get_user_prot_info)
449 slave->mtd._get_user_prot_info = part_get_user_prot_info;
450 if (master->_get_fact_prot_info)
451 slave->mtd._get_fact_prot_info = part_get_fact_prot_info;
453 slave->mtd._sync = part_sync;
455 if (!partno && !master->dev.class && master->_suspend &&
457 slave->mtd._suspend = part_suspend;
458 slave->mtd._resume = part_resume;
461 slave->mtd._writev = part_writev;
464 slave->mtd._lock = part_lock;
466 slave->mtd._unlock = part_unlock;
467 if (master->_is_locked)
468 slave->mtd._is_locked = part_is_locked;
469 if (master->_block_isreserved)
470 slave->mtd._block_isreserved = part_block_isreserved;
471 if (master->_block_isbad)
472 slave->mtd._block_isbad = part_block_isbad;
473 if (master->_block_markbad)
474 slave->mtd._block_markbad = part_block_markbad;
475 slave->mtd._erase = part_erase;
476 slave->master = master;
477 slave->offset = part->offset;
479 if (slave->offset == MTDPART_OFS_APPEND)
480 slave->offset = cur_offset;
481 if (slave->offset == MTDPART_OFS_NXTBLK) {
482 slave->offset = cur_offset;
483 if (mtd_mod_by_eb(cur_offset, master) != 0) {
484 /* Round up to next erasesize */
485 slave->offset = (mtd_div_by_eb(cur_offset, master) + 1) * master->erasesize;
486 debug("Moving partition %d: "
487 "0x%012llx -> 0x%012llx\n", partno,
488 (unsigned long long)cur_offset, (unsigned long long)slave->offset);
491 if (slave->offset == MTDPART_OFS_RETAIN) {
492 slave->offset = cur_offset;
493 if (master->size - slave->offset >= slave->mtd.size) {
494 slave->mtd.size = master->size - slave->offset
497 debug("mtd partition \"%s\" doesn't have enough space: %#llx < %#llx, disabled\n",
498 part->name, master->size - slave->offset,
500 /* register to preserve ordering */
504 if (slave->mtd.size == MTDPART_SIZ_FULL)
505 slave->mtd.size = master->size - slave->offset;
507 debug("0x%012llx-0x%012llx : \"%s\"\n", (unsigned long long)slave->offset,
508 (unsigned long long)(slave->offset + slave->mtd.size), slave->mtd.name);
510 /* let's do some sanity checks */
511 if (slave->offset >= master->size) {
512 /* let's register it anyway to preserve ordering */
515 printk(KERN_ERR"mtd: partition \"%s\" is out of reach -- disabled\n",
519 if (slave->offset + slave->mtd.size > master->size) {
520 slave->mtd.size = master->size - slave->offset;
521 printk(KERN_WARNING"mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#llx\n",
522 part->name, master->name, (unsigned long long)slave->mtd.size);
524 if (master->numeraseregions > 1) {
525 /* Deal with variable erase size stuff */
526 int i, max = master->numeraseregions;
527 u64 end = slave->offset + slave->mtd.size;
528 struct mtd_erase_region_info *regions = master->eraseregions;
530 /* Find the first erase regions which is part of this
532 for (i = 0; i < max && regions[i].offset <= slave->offset; i++)
534 /* The loop searched for the region _behind_ the first one */
538 /* Pick biggest erasesize */
539 for (; i < max && regions[i].offset < end; i++) {
540 if (slave->mtd.erasesize < regions[i].erasesize) {
541 slave->mtd.erasesize = regions[i].erasesize;
544 BUG_ON(slave->mtd.erasesize == 0);
546 /* Single erase size */
547 slave->mtd.erasesize = master->erasesize;
550 if ((slave->mtd.flags & MTD_WRITEABLE) &&
551 mtd_mod_by_eb(slave->offset, &slave->mtd)) {
552 /* Doesn't start on a boundary of major erase size */
553 /* FIXME: Let it be writable if it is on a boundary of
554 * _minor_ erase size though */
555 slave->mtd.flags &= ~MTD_WRITEABLE;
556 printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",
559 if ((slave->mtd.flags & MTD_WRITEABLE) &&
560 mtd_mod_by_eb(slave->mtd.size, &slave->mtd)) {
561 slave->mtd.flags &= ~MTD_WRITEABLE;
562 printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
566 slave->mtd.ecclayout = master->ecclayout;
567 slave->mtd.ecc_step_size = master->ecc_step_size;
568 slave->mtd.ecc_strength = master->ecc_strength;
569 slave->mtd.bitflip_threshold = master->bitflip_threshold;
571 if (master->_block_isbad) {
574 while (offs < slave->mtd.size) {
575 if (mtd_block_isbad(master, offs + slave->offset))
576 slave->mtd.ecc_stats.badblocks++;
577 offs += slave->mtd.erasesize;
586 int mtd_add_partition(struct mtd_info *master, const char *name,
587 long long offset, long long length)
589 struct mtd_partition part;
590 struct mtd_part *p, *new;
594 /* the direct offset is expected */
595 if (offset == MTDPART_OFS_APPEND ||
596 offset == MTDPART_OFS_NXTBLK)
599 if (length == MTDPART_SIZ_FULL)
600 length = master->size - offset;
607 part.offset = offset;
609 part.ecclayout = NULL;
611 new = allocate_partition(master, &part, -1, offset);
616 end = offset + length;
618 mutex_lock(&mtd_partitions_mutex);
619 list_for_each_entry(p, &mtd_partitions, list)
620 if (p->master == master) {
621 if ((start >= p->offset) &&
622 (start < (p->offset + p->mtd.size)))
625 if ((end >= p->offset) &&
626 (end < (p->offset + p->mtd.size)))
630 list_add(&new->list, &mtd_partitions);
631 mutex_unlock(&mtd_partitions_mutex);
633 add_mtd_device(&new->mtd);
637 mutex_unlock(&mtd_partitions_mutex);
641 EXPORT_SYMBOL_GPL(mtd_add_partition);
643 int mtd_del_partition(struct mtd_info *master, int partno)
645 struct mtd_part *slave, *next;
648 mutex_lock(&mtd_partitions_mutex);
649 list_for_each_entry_safe(slave, next, &mtd_partitions, list)
650 if ((slave->master == master) &&
651 (slave->mtd.index == partno)) {
652 ret = del_mtd_device(&slave->mtd);
656 list_del(&slave->list);
657 free_partition(slave);
660 mutex_unlock(&mtd_partitions_mutex);
664 EXPORT_SYMBOL_GPL(mtd_del_partition);
668 * This function, given a master MTD object and a partition table, creates
669 * and registers slave MTD objects which are bound to the master according to
670 * the partition definitions.
672 * We don't register the master, or expect the caller to have done so,
673 * for reasons of data integrity.
676 int add_mtd_partitions(struct mtd_info *master,
677 const struct mtd_partition *parts,
680 struct mtd_part *slave;
681 uint64_t cur_offset = 0;
686 * Need to init the list here, since LIST_INIT() does not
687 * work on platforms where relocation has problems (like MIPS
690 if (mtd_partitions.next == NULL)
691 INIT_LIST_HEAD(&mtd_partitions);
694 debug("Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);
696 for (i = 0; i < nbparts; i++) {
697 slave = allocate_partition(master, parts + i, i, cur_offset);
699 return PTR_ERR(slave);
701 mutex_lock(&mtd_partitions_mutex);
702 list_add(&slave->list, &mtd_partitions);
703 mutex_unlock(&mtd_partitions_mutex);
705 add_mtd_device(&slave->mtd);
707 cur_offset = slave->offset + slave->mtd.size;
714 static DEFINE_SPINLOCK(part_parser_lock);
715 static LIST_HEAD(part_parsers);
717 static struct mtd_part_parser *get_partition_parser(const char *name)
719 struct mtd_part_parser *p, *ret = NULL;
721 spin_lock(&part_parser_lock);
723 list_for_each_entry(p, &part_parsers, list)
724 if (!strcmp(p->name, name) && try_module_get(p->owner)) {
729 spin_unlock(&part_parser_lock);
734 #define put_partition_parser(p) do { module_put((p)->owner); } while (0)
736 void register_mtd_parser(struct mtd_part_parser *p)
738 spin_lock(&part_parser_lock);
739 list_add(&p->list, &part_parsers);
740 spin_unlock(&part_parser_lock);
742 EXPORT_SYMBOL_GPL(register_mtd_parser);
744 void deregister_mtd_parser(struct mtd_part_parser *p)
746 spin_lock(&part_parser_lock);
748 spin_unlock(&part_parser_lock);
750 EXPORT_SYMBOL_GPL(deregister_mtd_parser);
753 * Do not forget to update 'parse_mtd_partitions()' kerneldoc comment if you
754 * are changing this array!
756 static const char * const default_mtd_part_types[] = {
763 * parse_mtd_partitions - parse MTD partitions
764 * @master: the master partition (describes whole MTD device)
765 * @types: names of partition parsers to try or %NULL
766 * @pparts: array of partitions found is returned here
767 * @data: MTD partition parser-specific data
769 * This function tries to find partition on MTD device @master. It uses MTD
770 * partition parsers, specified in @types. However, if @types is %NULL, then
771 * the default list of parsers is used. The default list contains only the
772 * "cmdlinepart" and "ofpart" parsers ATM.
773 * Note: If there are more then one parser in @types, the kernel only takes the
774 * partitions parsed out by the first parser.
776 * This function may return:
777 * o a negative error code in case of failure
778 * o zero if no partitions were found
779 * o a positive number of found partitions, in which case on exit @pparts will
780 * point to an array containing this number of &struct mtd_info objects.
782 int parse_mtd_partitions(struct mtd_info *master, const char *const *types,
783 struct mtd_partition **pparts,
784 struct mtd_part_parser_data *data)
786 struct mtd_part_parser *parser;
790 types = default_mtd_part_types;
792 for ( ; ret <= 0 && *types; types++) {
793 parser = get_partition_parser(*types);
794 if (!parser && !request_module("%s", *types))
795 parser = get_partition_parser(*types);
798 ret = (*parser->parse_fn)(master, pparts, data);
799 put_partition_parser(parser);
801 printk(KERN_NOTICE "%d %s partitions found on MTD device %s\n",
802 ret, parser->name, master->name);
810 int mtd_is_partition(const struct mtd_info *mtd)
812 struct mtd_part *part;
815 mutex_lock(&mtd_partitions_mutex);
816 list_for_each_entry(part, &mtd_partitions, list)
817 if (&part->mtd == mtd) {
821 mutex_unlock(&mtd_partitions_mutex);
825 EXPORT_SYMBOL_GPL(mtd_is_partition);
827 /* Returns the size of the entire flash chip */
828 uint64_t mtd_get_device_size(const struct mtd_info *mtd)
830 if (!mtd_is_partition(mtd))
833 return PART(mtd)->master->size;
835 EXPORT_SYMBOL_GPL(mtd_get_device_size);