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+
14 #include <linux/module.h>
15 #include <linux/types.h>
16 #include <linux/kernel.h>
17 #include <linux/slab.h>
18 #include <linux/list.h>
19 #include <linux/kmod.h>
24 #include <asm/errno.h>
25 #include <linux/compat.h>
26 #include <ubi_uboot.h>
28 #include <linux/mtd/mtd.h>
29 #include <linux/mtd/partitions.h>
30 #include <linux/err.h>
34 /* Our partition linked list */
35 static LIST_HEAD(mtd_partitions);
37 static DEFINE_MUTEX(mtd_partitions_mutex);
39 DEFINE_MUTEX(mtd_partitions_mutex);
42 /* Our partition node structure */
45 struct mtd_info *master;
47 struct list_head list;
51 * Given a pointer to the MTD object in the mtd_part structure, we can retrieve
52 * the pointer to that structure with this macro.
54 #define PART(x) ((struct mtd_part *)(x))
61 * kstrdup - allocate space for and copy an existing string
62 * @s: the string to duplicate
63 * @gfp: the GFP mask used in the kmalloc() call when allocating memory
65 char *kstrdup(const char *s, gfp_t gfp)
74 buf = kmalloc(len, gfp);
82 * MTD methods which simply translate the effective address and pass through
83 * to the _real_ device.
86 static int part_read(struct mtd_info *mtd, loff_t from, size_t len,
87 size_t *retlen, u_char *buf)
89 struct mtd_part *part = PART(mtd);
90 struct mtd_ecc_stats stats;
93 stats = part->master->ecc_stats;
94 res = part->master->_read(part->master, from + part->offset, len,
96 if (unlikely(mtd_is_eccerr(res)))
97 mtd->ecc_stats.failed +=
98 part->master->ecc_stats.failed - stats.failed;
100 mtd->ecc_stats.corrected +=
101 part->master->ecc_stats.corrected - stats.corrected;
106 static int part_point(struct mtd_info *mtd, loff_t from, size_t len,
107 size_t *retlen, void **virt, resource_size_t *phys)
109 struct mtd_part *part = PART(mtd);
111 return part->master->_point(part->master, from + part->offset, len,
115 static int part_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
117 struct mtd_part *part = PART(mtd);
119 return part->master->_unpoint(part->master, from + part->offset, len);
123 static unsigned long part_get_unmapped_area(struct mtd_info *mtd,
125 unsigned long offset,
128 struct mtd_part *part = PART(mtd);
130 offset += part->offset;
131 return part->master->_get_unmapped_area(part->master, len, offset,
135 static int part_read_oob(struct mtd_info *mtd, loff_t from,
136 struct mtd_oob_ops *ops)
138 struct mtd_part *part = PART(mtd);
141 if (from >= mtd->size)
143 if (ops->datbuf && from + ops->len > mtd->size)
147 * If OOB is also requested, make sure that we do not read past the end
153 if (ops->mode == MTD_OPS_AUTO_OOB)
157 pages = mtd_div_by_ws(mtd->size, mtd);
158 pages -= mtd_div_by_ws(from, mtd);
159 if (ops->ooboffs + ops->ooblen > pages * len)
163 res = part->master->_read_oob(part->master, from + part->offset, ops);
165 if (mtd_is_bitflip(res))
166 mtd->ecc_stats.corrected++;
167 if (mtd_is_eccerr(res))
168 mtd->ecc_stats.failed++;
173 static int part_read_user_prot_reg(struct mtd_info *mtd, loff_t from,
174 size_t len, size_t *retlen, u_char *buf)
176 struct mtd_part *part = PART(mtd);
177 return part->master->_read_user_prot_reg(part->master, from, len,
181 static int part_get_user_prot_info(struct mtd_info *mtd, size_t len,
182 size_t *retlen, struct otp_info *buf)
184 struct mtd_part *part = PART(mtd);
185 return part->master->_get_user_prot_info(part->master, len, retlen,
189 static int part_read_fact_prot_reg(struct mtd_info *mtd, loff_t from,
190 size_t len, size_t *retlen, u_char *buf)
192 struct mtd_part *part = PART(mtd);
193 return part->master->_read_fact_prot_reg(part->master, from, len,
197 static int part_get_fact_prot_info(struct mtd_info *mtd, size_t len,
198 size_t *retlen, struct otp_info *buf)
200 struct mtd_part *part = PART(mtd);
201 return part->master->_get_fact_prot_info(part->master, len, retlen,
205 static int part_write(struct mtd_info *mtd, loff_t to, size_t len,
206 size_t *retlen, const u_char *buf)
208 struct mtd_part *part = PART(mtd);
209 return part->master->_write(part->master, to + part->offset, len,
213 static int part_panic_write(struct mtd_info *mtd, loff_t to, size_t len,
214 size_t *retlen, const u_char *buf)
216 struct mtd_part *part = PART(mtd);
217 return part->master->_panic_write(part->master, to + part->offset, len,
221 static int part_write_oob(struct mtd_info *mtd, loff_t to,
222 struct mtd_oob_ops *ops)
224 struct mtd_part *part = PART(mtd);
228 if (ops->datbuf && to + ops->len > mtd->size)
230 return part->master->_write_oob(part->master, to + part->offset, ops);
233 static int part_write_user_prot_reg(struct mtd_info *mtd, loff_t from,
234 size_t len, size_t *retlen, u_char *buf)
236 struct mtd_part *part = PART(mtd);
237 return part->master->_write_user_prot_reg(part->master, from, len,
241 static int part_lock_user_prot_reg(struct mtd_info *mtd, loff_t from,
244 struct mtd_part *part = PART(mtd);
245 return part->master->_lock_user_prot_reg(part->master, from, len);
249 static int part_writev(struct mtd_info *mtd, const struct kvec *vecs,
250 unsigned long count, loff_t to, size_t *retlen)
252 struct mtd_part *part = PART(mtd);
253 return part->master->_writev(part->master, vecs, count,
254 to + part->offset, retlen);
258 static int part_erase(struct mtd_info *mtd, struct erase_info *instr)
260 struct mtd_part *part = PART(mtd);
263 instr->addr += part->offset;
264 ret = part->master->_erase(part->master, instr);
266 if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
267 instr->fail_addr -= part->offset;
268 instr->addr -= part->offset;
273 void mtd_erase_callback(struct erase_info *instr)
275 if (instr->mtd->_erase == part_erase) {
276 struct mtd_part *part = PART(instr->mtd);
278 if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
279 instr->fail_addr -= part->offset;
280 instr->addr -= part->offset;
283 instr->callback(instr);
285 EXPORT_SYMBOL_GPL(mtd_erase_callback);
287 static int part_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
289 struct mtd_part *part = PART(mtd);
290 return part->master->_lock(part->master, ofs + part->offset, len);
293 static int part_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
295 struct mtd_part *part = PART(mtd);
296 return part->master->_unlock(part->master, ofs + part->offset, len);
299 static int part_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
301 struct mtd_part *part = PART(mtd);
302 return part->master->_is_locked(part->master, ofs + part->offset, len);
305 static void part_sync(struct mtd_info *mtd)
307 struct mtd_part *part = PART(mtd);
308 part->master->_sync(part->master);
312 static int part_suspend(struct mtd_info *mtd)
314 struct mtd_part *part = PART(mtd);
315 return part->master->_suspend(part->master);
318 static void part_resume(struct mtd_info *mtd)
320 struct mtd_part *part = PART(mtd);
321 part->master->_resume(part->master);
325 static int part_block_isbad(struct mtd_info *mtd, loff_t ofs)
327 struct mtd_part *part = PART(mtd);
329 return part->master->_block_isbad(part->master, ofs);
332 static int part_block_markbad(struct mtd_info *mtd, loff_t ofs)
334 struct mtd_part *part = PART(mtd);
338 res = part->master->_block_markbad(part->master, ofs);
340 mtd->ecc_stats.badblocks++;
344 static inline void free_partition(struct mtd_part *p)
351 * This function unregisters and destroy all slave MTD objects which are
352 * attached to the given master MTD object.
355 int del_mtd_partitions(struct mtd_info *master)
357 struct mtd_part *slave, *next;
360 mutex_lock(&mtd_partitions_mutex);
361 list_for_each_entry_safe(slave, next, &mtd_partitions, list)
362 if (slave->master == master) {
363 ret = del_mtd_device(&slave->mtd);
368 list_del(&slave->list);
369 free_partition(slave);
371 mutex_unlock(&mtd_partitions_mutex);
376 static struct mtd_part *allocate_partition(struct mtd_info *master,
377 const struct mtd_partition *part, int partno,
380 struct mtd_part *slave;
383 /* allocate the partition structure */
384 slave = kzalloc(sizeof(*slave), GFP_KERNEL);
385 name = kstrdup(part->name, GFP_KERNEL);
386 if (!name || !slave) {
387 printk(KERN_ERR"memory allocation error while creating partitions for \"%s\"\n",
391 return ERR_PTR(-ENOMEM);
394 /* set up the MTD object for this partition */
395 slave->mtd.type = master->type;
396 slave->mtd.flags = master->flags & ~part->mask_flags;
397 slave->mtd.size = part->size;
398 slave->mtd.writesize = master->writesize;
399 slave->mtd.writebufsize = master->writebufsize;
400 slave->mtd.oobsize = master->oobsize;
401 slave->mtd.oobavail = master->oobavail;
402 slave->mtd.subpage_sft = master->subpage_sft;
404 slave->mtd.name = name;
405 slave->mtd.owner = master->owner;
407 slave->mtd.backing_dev_info = master->backing_dev_info;
409 /* NOTE: we don't arrange MTDs as a tree; it'd be error-prone
410 * to have the same data be in two different partitions.
412 slave->mtd.dev.parent = master->dev.parent;
415 slave->mtd._read = part_read;
416 slave->mtd._write = part_write;
418 if (master->_panic_write)
419 slave->mtd._panic_write = part_panic_write;
422 if (master->_point && master->_unpoint) {
423 slave->mtd._point = part_point;
424 slave->mtd._unpoint = part_unpoint;
428 if (master->_get_unmapped_area)
429 slave->mtd._get_unmapped_area = part_get_unmapped_area;
430 if (master->_read_oob)
431 slave->mtd._read_oob = part_read_oob;
432 if (master->_write_oob)
433 slave->mtd._write_oob = part_write_oob;
434 if (master->_read_user_prot_reg)
435 slave->mtd._read_user_prot_reg = part_read_user_prot_reg;
436 if (master->_read_fact_prot_reg)
437 slave->mtd._read_fact_prot_reg = part_read_fact_prot_reg;
438 if (master->_write_user_prot_reg)
439 slave->mtd._write_user_prot_reg = part_write_user_prot_reg;
440 if (master->_lock_user_prot_reg)
441 slave->mtd._lock_user_prot_reg = part_lock_user_prot_reg;
442 if (master->_get_user_prot_info)
443 slave->mtd._get_user_prot_info = part_get_user_prot_info;
444 if (master->_get_fact_prot_info)
445 slave->mtd._get_fact_prot_info = part_get_fact_prot_info;
447 slave->mtd._sync = part_sync;
449 if (!partno && !master->dev.class && master->_suspend &&
451 slave->mtd._suspend = part_suspend;
452 slave->mtd._resume = part_resume;
455 slave->mtd._writev = part_writev;
458 slave->mtd._lock = part_lock;
460 slave->mtd._unlock = part_unlock;
461 if (master->_is_locked)
462 slave->mtd._is_locked = part_is_locked;
463 if (master->_block_isbad)
464 slave->mtd._block_isbad = part_block_isbad;
465 if (master->_block_markbad)
466 slave->mtd._block_markbad = part_block_markbad;
467 slave->mtd._erase = part_erase;
468 slave->master = master;
469 slave->offset = part->offset;
471 if (slave->offset == MTDPART_OFS_APPEND)
472 slave->offset = cur_offset;
473 if (slave->offset == MTDPART_OFS_NXTBLK) {
474 slave->offset = cur_offset;
475 if (mtd_mod_by_eb(cur_offset, master) != 0) {
476 /* Round up to next erasesize */
477 slave->offset = (mtd_div_by_eb(cur_offset, master) + 1) * master->erasesize;
478 debug("Moving partition %d: "
479 "0x%012llx -> 0x%012llx\n", partno,
480 (unsigned long long)cur_offset, (unsigned long long)slave->offset);
483 if (slave->offset == MTDPART_OFS_RETAIN) {
484 slave->offset = cur_offset;
485 if (master->size - slave->offset >= slave->mtd.size) {
486 slave->mtd.size = master->size - slave->offset
489 debug("mtd partition \"%s\" doesn't have enough space: %#llx < %#llx, disabled\n",
490 part->name, master->size - slave->offset,
492 /* register to preserve ordering */
496 if (slave->mtd.size == MTDPART_SIZ_FULL)
497 slave->mtd.size = master->size - slave->offset;
499 debug("0x%012llx-0x%012llx : \"%s\"\n", (unsigned long long)slave->offset,
500 (unsigned long long)(slave->offset + slave->mtd.size), slave->mtd.name);
502 /* let's do some sanity checks */
503 if (slave->offset >= master->size) {
504 /* let's register it anyway to preserve ordering */
507 printk(KERN_ERR"mtd: partition \"%s\" is out of reach -- disabled\n",
511 if (slave->offset + slave->mtd.size > master->size) {
512 slave->mtd.size = master->size - slave->offset;
513 printk(KERN_WARNING"mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#llx\n",
514 part->name, master->name, (unsigned long long)slave->mtd.size);
516 if (master->numeraseregions > 1) {
517 /* Deal with variable erase size stuff */
518 int i, max = master->numeraseregions;
519 u64 end = slave->offset + slave->mtd.size;
520 struct mtd_erase_region_info *regions = master->eraseregions;
522 /* Find the first erase regions which is part of this
524 for (i = 0; i < max && regions[i].offset <= slave->offset; i++)
526 /* The loop searched for the region _behind_ the first one */
530 /* Pick biggest erasesize */
531 for (; i < max && regions[i].offset < end; i++) {
532 if (slave->mtd.erasesize < regions[i].erasesize) {
533 slave->mtd.erasesize = regions[i].erasesize;
536 BUG_ON(slave->mtd.erasesize == 0);
538 /* Single erase size */
539 slave->mtd.erasesize = master->erasesize;
542 if ((slave->mtd.flags & MTD_WRITEABLE) &&
543 mtd_mod_by_eb(slave->offset, &slave->mtd)) {
544 /* Doesn't start on a boundary of major erase size */
545 /* FIXME: Let it be writable if it is on a boundary of
546 * _minor_ erase size though */
547 slave->mtd.flags &= ~MTD_WRITEABLE;
548 printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",
551 if ((slave->mtd.flags & MTD_WRITEABLE) &&
552 mtd_mod_by_eb(slave->mtd.size, &slave->mtd)) {
553 slave->mtd.flags &= ~MTD_WRITEABLE;
554 printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
558 slave->mtd.ecclayout = master->ecclayout;
559 slave->mtd.ecc_step_size = master->ecc_step_size;
560 slave->mtd.ecc_strength = master->ecc_strength;
561 slave->mtd.bitflip_threshold = master->bitflip_threshold;
563 if (master->_block_isbad) {
566 while (offs < slave->mtd.size) {
567 if (mtd_block_isbad(master, offs + slave->offset))
568 slave->mtd.ecc_stats.badblocks++;
569 offs += slave->mtd.erasesize;
578 int mtd_add_partition(struct mtd_info *master, const char *name,
579 long long offset, long long length)
581 struct mtd_partition part;
582 struct mtd_part *p, *new;
586 /* the direct offset is expected */
587 if (offset == MTDPART_OFS_APPEND ||
588 offset == MTDPART_OFS_NXTBLK)
591 if (length == MTDPART_SIZ_FULL)
592 length = master->size - offset;
599 part.offset = offset;
601 part.ecclayout = NULL;
603 new = allocate_partition(master, &part, -1, offset);
608 end = offset + length;
610 mutex_lock(&mtd_partitions_mutex);
611 list_for_each_entry(p, &mtd_partitions, list)
612 if (p->master == master) {
613 if ((start >= p->offset) &&
614 (start < (p->offset + p->mtd.size)))
617 if ((end >= p->offset) &&
618 (end < (p->offset + p->mtd.size)))
622 list_add(&new->list, &mtd_partitions);
623 mutex_unlock(&mtd_partitions_mutex);
625 add_mtd_device(&new->mtd);
629 mutex_unlock(&mtd_partitions_mutex);
633 EXPORT_SYMBOL_GPL(mtd_add_partition);
635 int mtd_del_partition(struct mtd_info *master, int partno)
637 struct mtd_part *slave, *next;
640 mutex_lock(&mtd_partitions_mutex);
641 list_for_each_entry_safe(slave, next, &mtd_partitions, list)
642 if ((slave->master == master) &&
643 (slave->mtd.index == partno)) {
644 ret = del_mtd_device(&slave->mtd);
648 list_del(&slave->list);
649 free_partition(slave);
652 mutex_unlock(&mtd_partitions_mutex);
656 EXPORT_SYMBOL_GPL(mtd_del_partition);
660 * This function, given a master MTD object and a partition table, creates
661 * and registers slave MTD objects which are bound to the master according to
662 * the partition definitions.
664 * We don't register the master, or expect the caller to have done so,
665 * for reasons of data integrity.
668 int add_mtd_partitions(struct mtd_info *master,
669 const struct mtd_partition *parts,
672 struct mtd_part *slave;
673 uint64_t cur_offset = 0;
678 * Need to init the list here, since LIST_INIT() does not
679 * work on platforms where relocation has problems (like MIPS
682 if (mtd_partitions.next == NULL)
683 INIT_LIST_HEAD(&mtd_partitions);
686 debug("Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);
688 for (i = 0; i < nbparts; i++) {
689 slave = allocate_partition(master, parts + i, i, cur_offset);
691 return PTR_ERR(slave);
693 mutex_lock(&mtd_partitions_mutex);
694 list_add(&slave->list, &mtd_partitions);
695 mutex_unlock(&mtd_partitions_mutex);
697 add_mtd_device(&slave->mtd);
699 cur_offset = slave->offset + slave->mtd.size;
706 static DEFINE_SPINLOCK(part_parser_lock);
707 static LIST_HEAD(part_parsers);
709 static struct mtd_part_parser *get_partition_parser(const char *name)
711 struct mtd_part_parser *p, *ret = NULL;
713 spin_lock(&part_parser_lock);
715 list_for_each_entry(p, &part_parsers, list)
716 if (!strcmp(p->name, name) && try_module_get(p->owner)) {
721 spin_unlock(&part_parser_lock);
726 #define put_partition_parser(p) do { module_put((p)->owner); } while (0)
728 void register_mtd_parser(struct mtd_part_parser *p)
730 spin_lock(&part_parser_lock);
731 list_add(&p->list, &part_parsers);
732 spin_unlock(&part_parser_lock);
734 EXPORT_SYMBOL_GPL(register_mtd_parser);
736 void deregister_mtd_parser(struct mtd_part_parser *p)
738 spin_lock(&part_parser_lock);
740 spin_unlock(&part_parser_lock);
742 EXPORT_SYMBOL_GPL(deregister_mtd_parser);
745 * Do not forget to update 'parse_mtd_partitions()' kerneldoc comment if you
746 * are changing this array!
748 static const char * const default_mtd_part_types[] = {
755 * parse_mtd_partitions - parse MTD partitions
756 * @master: the master partition (describes whole MTD device)
757 * @types: names of partition parsers to try or %NULL
758 * @pparts: array of partitions found is returned here
759 * @data: MTD partition parser-specific data
761 * This function tries to find partition on MTD device @master. It uses MTD
762 * partition parsers, specified in @types. However, if @types is %NULL, then
763 * the default list of parsers is used. The default list contains only the
764 * "cmdlinepart" and "ofpart" parsers ATM.
765 * Note: If there are more then one parser in @types, the kernel only takes the
766 * partitions parsed out by the first parser.
768 * This function may return:
769 * o a negative error code in case of failure
770 * o zero if no partitions were found
771 * o a positive number of found partitions, in which case on exit @pparts will
772 * point to an array containing this number of &struct mtd_info objects.
774 int parse_mtd_partitions(struct mtd_info *master, const char *const *types,
775 struct mtd_partition **pparts,
776 struct mtd_part_parser_data *data)
778 struct mtd_part_parser *parser;
782 types = default_mtd_part_types;
784 for ( ; ret <= 0 && *types; types++) {
785 parser = get_partition_parser(*types);
786 if (!parser && !request_module("%s", *types))
787 parser = get_partition_parser(*types);
790 ret = (*parser->parse_fn)(master, pparts, data);
791 put_partition_parser(parser);
793 printk(KERN_NOTICE "%d %s partitions found on MTD device %s\n",
794 ret, parser->name, master->name);
802 int mtd_is_partition(const struct mtd_info *mtd)
804 struct mtd_part *part;
807 mutex_lock(&mtd_partitions_mutex);
808 list_for_each_entry(part, &mtd_partitions, list)
809 if (&part->mtd == mtd) {
813 mutex_unlock(&mtd_partitions_mutex);
817 EXPORT_SYMBOL_GPL(mtd_is_partition);
819 /* Returns the size of the entire flash chip */
820 uint64_t mtd_get_device_size(const struct mtd_info *mtd)
822 if (!mtd_is_partition(mtd))
825 return PART(mtd)->master->size;
827 EXPORT_SYMBOL_GPL(mtd_get_device_size);