1/*
2 * Simple MTD partitioning layer
3 *
4 * Copyright © 2000 Nicolas Pitre <nico@fluxnic.net>
5 * Copyright © 2002 Thomas Gleixner <gleixner@linutronix.de>
6 * Copyright © 2000-2010 David Woodhouse <dwmw2@infradead.org>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
21 *
22 */
23
24#include <linux/module.h>
25#include <linux/types.h>
26#include <linux/kernel.h>
27#include <linux/slab.h>
28#include <linux/list.h>
29#include <linux/kmod.h>
30#include <linux/mtd/mtd.h>
31#include <linux/mtd/partitions.h>
32#include <linux/err.h>
33#include <linux/kconfig.h>
34
35#include "mtdcore.h"
36
37/* Our partition linked list */
38static LIST_HEAD(mtd_partitions);
39static DEFINE_MUTEX(mtd_partitions_mutex);
40
41/* Our partition node structure */
42struct mtd_part {
43	struct mtd_info mtd;
44	struct mtd_info *master;
45	uint64_t offset;
46	struct list_head list;
47};
48
49/*
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.
52 */
53#define PART(x)  ((struct mtd_part *)(x))
54
55
56/*
57 * MTD methods which simply translate the effective address and pass through
58 * to the _real_ device.
59 */
60
61static int part_read(struct mtd_info *mtd, loff_t from, size_t len,
62		size_t *retlen, u_char *buf)
63{
64	struct mtd_part *part = PART(mtd);
65	struct mtd_ecc_stats stats;
66	int res;
67
68	stats = part->master->ecc_stats;
69	res = part->master->_read(part->master, from + part->offset, len,
70				  retlen, buf);
71	if (unlikely(mtd_is_eccerr(res)))
72		mtd->ecc_stats.failed +=
73			part->master->ecc_stats.failed - stats.failed;
74	else
75		mtd->ecc_stats.corrected +=
76			part->master->ecc_stats.corrected - stats.corrected;
77	return res;
78}
79
80static int part_point(struct mtd_info *mtd, loff_t from, size_t len,
81		size_t *retlen, void **virt, resource_size_t *phys)
82{
83	struct mtd_part *part = PART(mtd);
84
85	return part->master->_point(part->master, from + part->offset, len,
86				    retlen, virt, phys);
87}
88
89static int part_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
90{
91	struct mtd_part *part = PART(mtd);
92
93	return part->master->_unpoint(part->master, from + part->offset, len);
94}
95
96static unsigned long part_get_unmapped_area(struct mtd_info *mtd,
97					    unsigned long len,
98					    unsigned long offset,
99					    unsigned long flags)
100{
101	struct mtd_part *part = PART(mtd);
102
103	offset += part->offset;
104	return part->master->_get_unmapped_area(part->master, len, offset,
105						flags);
106}
107
108static int part_read_oob(struct mtd_info *mtd, loff_t from,
109		struct mtd_oob_ops *ops)
110{
111	struct mtd_part *part = PART(mtd);
112	int res;
113
114	if (from >= mtd->size)
115		return -EINVAL;
116	if (ops->datbuf && from + ops->len > mtd->size)
117		return -EINVAL;
118
119	/*
120	 * If OOB is also requested, make sure that we do not read past the end
121	 * of this partition.
122	 */
123	if (ops->oobbuf) {
124		size_t len, pages;
125
126		if (ops->mode == MTD_OPS_AUTO_OOB)
127			len = mtd->oobavail;
128		else
129			len = mtd->oobsize;
130		pages = mtd_div_by_ws(mtd->size, mtd);
131		pages -= mtd_div_by_ws(from, mtd);
132		if (ops->ooboffs + ops->ooblen > pages * len)
133			return -EINVAL;
134	}
135
136	res = part->master->_read_oob(part->master, from + part->offset, ops);
137	if (unlikely(res)) {
138		if (mtd_is_bitflip(res))
139			mtd->ecc_stats.corrected++;
140		if (mtd_is_eccerr(res))
141			mtd->ecc_stats.failed++;
142	}
143	return res;
144}
145
146static int part_read_user_prot_reg(struct mtd_info *mtd, loff_t from,
147		size_t len, size_t *retlen, u_char *buf)
148{
149	struct mtd_part *part = PART(mtd);
150	return part->master->_read_user_prot_reg(part->master, from, len,
151						 retlen, buf);
152}
153
154static int part_get_user_prot_info(struct mtd_info *mtd, size_t len,
155				   size_t *retlen, struct otp_info *buf)
156{
157	struct mtd_part *part = PART(mtd);
158	return part->master->_get_user_prot_info(part->master, len, retlen,
159						 buf);
160}
161
162static int part_read_fact_prot_reg(struct mtd_info *mtd, loff_t from,
163		size_t len, size_t *retlen, u_char *buf)
164{
165	struct mtd_part *part = PART(mtd);
166	return part->master->_read_fact_prot_reg(part->master, from, len,
167						 retlen, buf);
168}
169
170static int part_get_fact_prot_info(struct mtd_info *mtd, size_t len,
171				   size_t *retlen, struct otp_info *buf)
172{
173	struct mtd_part *part = PART(mtd);
174	return part->master->_get_fact_prot_info(part->master, len, retlen,
175						 buf);
176}
177
178static int part_write(struct mtd_info *mtd, loff_t to, size_t len,
179		size_t *retlen, const u_char *buf)
180{
181	struct mtd_part *part = PART(mtd);
182	return part->master->_write(part->master, to + part->offset, len,
183				    retlen, buf);
184}
185
186static int part_panic_write(struct mtd_info *mtd, loff_t to, size_t len,
187		size_t *retlen, const u_char *buf)
188{
189	struct mtd_part *part = PART(mtd);
190	return part->master->_panic_write(part->master, to + part->offset, len,
191					  retlen, buf);
192}
193
194static int part_write_oob(struct mtd_info *mtd, loff_t to,
195		struct mtd_oob_ops *ops)
196{
197	struct mtd_part *part = PART(mtd);
198
199	if (to >= mtd->size)
200		return -EINVAL;
201	if (ops->datbuf && to + ops->len > mtd->size)
202		return -EINVAL;
203	return part->master->_write_oob(part->master, to + part->offset, ops);
204}
205
206static int part_write_user_prot_reg(struct mtd_info *mtd, loff_t from,
207		size_t len, size_t *retlen, u_char *buf)
208{
209	struct mtd_part *part = PART(mtd);
210	return part->master->_write_user_prot_reg(part->master, from, len,
211						  retlen, buf);
212}
213
214static int part_lock_user_prot_reg(struct mtd_info *mtd, loff_t from,
215		size_t len)
216{
217	struct mtd_part *part = PART(mtd);
218	return part->master->_lock_user_prot_reg(part->master, from, len);
219}
220
221static int part_writev(struct mtd_info *mtd, const struct kvec *vecs,
222		unsigned long count, loff_t to, size_t *retlen)
223{
224	struct mtd_part *part = PART(mtd);
225	return part->master->_writev(part->master, vecs, count,
226				     to + part->offset, retlen);
227}
228
229static int part_erase(struct mtd_info *mtd, struct erase_info *instr)
230{
231	struct mtd_part *part = PART(mtd);
232	int ret;
233
234	instr->addr += part->offset;
235	ret = part->master->_erase(part->master, instr);
236	if (ret) {
237		if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
238			instr->fail_addr -= part->offset;
239		instr->addr -= part->offset;
240	}
241	return ret;
242}
243
244void mtd_erase_callback(struct erase_info *instr)
245{
246	if (instr->mtd->_erase == part_erase) {
247		struct mtd_part *part = PART(instr->mtd);
248
249		if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
250			instr->fail_addr -= part->offset;
251		instr->addr -= part->offset;
252	}
253	if (instr->callback)
254		instr->callback(instr);
255}
256EXPORT_SYMBOL_GPL(mtd_erase_callback);
257
258static int part_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
259{
260	struct mtd_part *part = PART(mtd);
261	return part->master->_lock(part->master, ofs + part->offset, len);
262}
263
264static int part_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
265{
266	struct mtd_part *part = PART(mtd);
267	return part->master->_unlock(part->master, ofs + part->offset, len);
268}
269
270static int part_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
271{
272	struct mtd_part *part = PART(mtd);
273	return part->master->_is_locked(part->master, ofs + part->offset, len);
274}
275
276static void part_sync(struct mtd_info *mtd)
277{
278	struct mtd_part *part = PART(mtd);
279	part->master->_sync(part->master);
280}
281
282static int part_suspend(struct mtd_info *mtd)
283{
284	struct mtd_part *part = PART(mtd);
285	return part->master->_suspend(part->master);
286}
287
288static void part_resume(struct mtd_info *mtd)
289{
290	struct mtd_part *part = PART(mtd);
291	part->master->_resume(part->master);
292}
293
294static int part_block_isreserved(struct mtd_info *mtd, loff_t ofs)
295{
296	struct mtd_part *part = PART(mtd);
297	ofs += part->offset;
298	return part->master->_block_isreserved(part->master, ofs);
299}
300
301static int part_block_isbad(struct mtd_info *mtd, loff_t ofs)
302{
303	struct mtd_part *part = PART(mtd);
304	ofs += part->offset;
305	return part->master->_block_isbad(part->master, ofs);
306}
307
308static int part_block_markbad(struct mtd_info *mtd, loff_t ofs)
309{
310	struct mtd_part *part = PART(mtd);
311	int res;
312
313	ofs += part->offset;
314	res = part->master->_block_markbad(part->master, ofs);
315	if (!res)
316		mtd->ecc_stats.badblocks++;
317	return res;
318}
319
320static inline void free_partition(struct mtd_part *p)
321{
322	kfree(p->mtd.name);
323	kfree(p);
324}
325
326/*
327 * This function unregisters and destroy all slave MTD objects which are
328 * attached to the given master MTD object.
329 */
330
331int del_mtd_partitions(struct mtd_info *master)
332{
333	struct mtd_part *slave, *next;
334	int ret, err = 0;
335
336	mutex_lock(&mtd_partitions_mutex);
337	list_for_each_entry_safe(slave, next, &mtd_partitions, list)
338		if (slave->master == master) {
339			ret = del_mtd_device(&slave->mtd);
340			if (ret < 0) {
341				err = ret;
342				continue;
343			}
344			list_del(&slave->list);
345			free_partition(slave);
346		}
347	mutex_unlock(&mtd_partitions_mutex);
348
349	return err;
350}
351
352static struct mtd_part *allocate_partition(struct mtd_info *master,
353			const struct mtd_partition *part, int partno,
354			uint64_t cur_offset)
355{
356	struct mtd_part *slave;
357	char *name;
358
359	/* allocate the partition structure */
360	slave = kzalloc(sizeof(*slave), GFP_KERNEL);
361	name = kstrdup(part->name, GFP_KERNEL);
362	if (!name || !slave) {
363		printk(KERN_ERR"memory allocation error while creating partitions for \"%s\"\n",
364		       master->name);
365		kfree(name);
366		kfree(slave);
367		return ERR_PTR(-ENOMEM);
368	}
369
370	/* set up the MTD object for this partition */
371	slave->mtd.type = master->type;
372	slave->mtd.flags = master->flags & ~part->mask_flags;
373	slave->mtd.size = part->size;
374	slave->mtd.writesize = master->writesize;
375	slave->mtd.writebufsize = master->writebufsize;
376	slave->mtd.oobsize = master->oobsize;
377	slave->mtd.oobavail = master->oobavail;
378	slave->mtd.subpage_sft = master->subpage_sft;
379
380	slave->mtd.name = name;
381	slave->mtd.owner = master->owner;
382
383	/* NOTE: Historically, we didn't arrange MTDs as a tree out of
384	 * concern for showing the same data in multiple partitions.
385	 * However, it is very useful to have the master node present,
386	 * so the MTD_PARTITIONED_MASTER option allows that. The master
387	 * will have device nodes etc only if this is set, so make the
388	 * parent conditional on that option. Note, this is a way to
389	 * distinguish between the master and the partition in sysfs.
390	 */
391	slave->mtd.dev.parent = IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER) ?
392				&master->dev :
393				master->dev.parent;
394
395	slave->mtd._read = part_read;
396	slave->mtd._write = part_write;
397
398	if (master->_panic_write)
399		slave->mtd._panic_write = part_panic_write;
400
401	if (master->_point && master->_unpoint) {
402		slave->mtd._point = part_point;
403		slave->mtd._unpoint = part_unpoint;
404	}
405
406	if (master->_get_unmapped_area)
407		slave->mtd._get_unmapped_area = part_get_unmapped_area;
408	if (master->_read_oob)
409		slave->mtd._read_oob = part_read_oob;
410	if (master->_write_oob)
411		slave->mtd._write_oob = part_write_oob;
412	if (master->_read_user_prot_reg)
413		slave->mtd._read_user_prot_reg = part_read_user_prot_reg;
414	if (master->_read_fact_prot_reg)
415		slave->mtd._read_fact_prot_reg = part_read_fact_prot_reg;
416	if (master->_write_user_prot_reg)
417		slave->mtd._write_user_prot_reg = part_write_user_prot_reg;
418	if (master->_lock_user_prot_reg)
419		slave->mtd._lock_user_prot_reg = part_lock_user_prot_reg;
420	if (master->_get_user_prot_info)
421		slave->mtd._get_user_prot_info = part_get_user_prot_info;
422	if (master->_get_fact_prot_info)
423		slave->mtd._get_fact_prot_info = part_get_fact_prot_info;
424	if (master->_sync)
425		slave->mtd._sync = part_sync;
426	if (!partno && !master->dev.class && master->_suspend &&
427	    master->_resume) {
428			slave->mtd._suspend = part_suspend;
429			slave->mtd._resume = part_resume;
430	}
431	if (master->_writev)
432		slave->mtd._writev = part_writev;
433	if (master->_lock)
434		slave->mtd._lock = part_lock;
435	if (master->_unlock)
436		slave->mtd._unlock = part_unlock;
437	if (master->_is_locked)
438		slave->mtd._is_locked = part_is_locked;
439	if (master->_block_isreserved)
440		slave->mtd._block_isreserved = part_block_isreserved;
441	if (master->_block_isbad)
442		slave->mtd._block_isbad = part_block_isbad;
443	if (master->_block_markbad)
444		slave->mtd._block_markbad = part_block_markbad;
445	slave->mtd._erase = part_erase;
446	slave->master = master;
447	slave->offset = part->offset;
448
449	if (slave->offset == MTDPART_OFS_APPEND)
450		slave->offset = cur_offset;
451	if (slave->offset == MTDPART_OFS_NXTBLK) {
452		slave->offset = cur_offset;
453		if (mtd_mod_by_eb(cur_offset, master) != 0) {
454			/* Round up to next erasesize */
455			slave->offset = (mtd_div_by_eb(cur_offset, master) + 1) * master->erasesize;
456			printk(KERN_NOTICE "Moving partition %d: "
457			       "0x%012llx -> 0x%012llx\n", partno,
458			       (unsigned long long)cur_offset, (unsigned long long)slave->offset);
459		}
460	}
461	if (slave->offset == MTDPART_OFS_RETAIN) {
462		slave->offset = cur_offset;
463		if (master->size - slave->offset >= slave->mtd.size) {
464			slave->mtd.size = master->size - slave->offset
465							- slave->mtd.size;
466		} else {
467			printk(KERN_ERR "mtd partition \"%s\" doesn't have enough space: %#llx < %#llx, disabled\n",
468				part->name, master->size - slave->offset,
469				slave->mtd.size);
470			/* register to preserve ordering */
471			goto out_register;
472		}
473	}
474	if (slave->mtd.size == MTDPART_SIZ_FULL)
475		slave->mtd.size = master->size - slave->offset;
476
477	printk(KERN_NOTICE "0x%012llx-0x%012llx : \"%s\"\n", (unsigned long long)slave->offset,
478		(unsigned long long)(slave->offset + slave->mtd.size), slave->mtd.name);
479
480	/* let's do some sanity checks */
481	if (slave->offset >= master->size) {
482		/* let's register it anyway to preserve ordering */
483		slave->offset = 0;
484		slave->mtd.size = 0;
485		printk(KERN_ERR"mtd: partition \"%s\" is out of reach -- disabled\n",
486			part->name);
487		goto out_register;
488	}
489	if (slave->offset + slave->mtd.size > master->size) {
490		slave->mtd.size = master->size - slave->offset;
491		printk(KERN_WARNING"mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#llx\n",
492			part->name, master->name, (unsigned long long)slave->mtd.size);
493	}
494	if (master->numeraseregions > 1) {
495		/* Deal with variable erase size stuff */
496		int i, max = master->numeraseregions;
497		u64 end = slave->offset + slave->mtd.size;
498		struct mtd_erase_region_info *regions = master->eraseregions;
499
500		/* Find the first erase regions which is part of this
501		 * partition. */
502		for (i = 0; i < max && regions[i].offset <= slave->offset; i++)
503			;
504		/* The loop searched for the region _behind_ the first one */
505		if (i > 0)
506			i--;
507
508		/* Pick biggest erasesize */
509		for (; i < max && regions[i].offset < end; i++) {
510			if (slave->mtd.erasesize < regions[i].erasesize) {
511				slave->mtd.erasesize = regions[i].erasesize;
512			}
513		}
514		BUG_ON(slave->mtd.erasesize == 0);
515	} else {
516		/* Single erase size */
517		slave->mtd.erasesize = master->erasesize;
518	}
519
520	if ((slave->mtd.flags & MTD_WRITEABLE) &&
521	    mtd_mod_by_eb(slave->offset, &slave->mtd)) {
522		/* Doesn't start on a boundary of major erase size */
523		/* FIXME: Let it be writable if it is on a boundary of
524		 * _minor_ erase size though */
525		slave->mtd.flags &= ~MTD_WRITEABLE;
526		printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",
527			part->name);
528	}
529	if ((slave->mtd.flags & MTD_WRITEABLE) &&
530	    mtd_mod_by_eb(slave->mtd.size, &slave->mtd)) {
531		slave->mtd.flags &= ~MTD_WRITEABLE;
532		printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
533			part->name);
534	}
535
536	slave->mtd.ecclayout = master->ecclayout;
537	slave->mtd.ecc_step_size = master->ecc_step_size;
538	slave->mtd.ecc_strength = master->ecc_strength;
539	slave->mtd.bitflip_threshold = master->bitflip_threshold;
540
541	if (master->_block_isbad) {
542		uint64_t offs = 0;
543
544		while (offs < slave->mtd.size) {
545			if (mtd_block_isreserved(master, offs + slave->offset))
546				slave->mtd.ecc_stats.bbtblocks++;
547			else if (mtd_block_isbad(master, offs + slave->offset))
548				slave->mtd.ecc_stats.badblocks++;
549			offs += slave->mtd.erasesize;
550		}
551	}
552
553out_register:
554	return slave;
555}
556
557static ssize_t mtd_partition_offset_show(struct device *dev,
558		struct device_attribute *attr, char *buf)
559{
560	struct mtd_info *mtd = dev_get_drvdata(dev);
561	struct mtd_part *part = PART(mtd);
562	return snprintf(buf, PAGE_SIZE, "%lld\n", part->offset);
563}
564
565static DEVICE_ATTR(offset, S_IRUGO, mtd_partition_offset_show, NULL);
566
567static const struct attribute *mtd_partition_attrs[] = {
568	&dev_attr_offset.attr,
569	NULL
570};
571
572static int mtd_add_partition_attrs(struct mtd_part *new)
573{
574	int ret = sysfs_create_files(&new->mtd.dev.kobj, mtd_partition_attrs);
575	if (ret)
576		printk(KERN_WARNING
577		       "mtd: failed to create partition attrs, err=%d\n", ret);
578	return ret;
579}
580
581int mtd_add_partition(struct mtd_info *master, const char *name,
582		      long long offset, long long length)
583{
584	struct mtd_partition part;
585	struct mtd_part *new;
586	int ret = 0;
587
588	/* the direct offset is expected */
589	if (offset == MTDPART_OFS_APPEND ||
590	    offset == MTDPART_OFS_NXTBLK)
591		return -EINVAL;
592
593	if (length == MTDPART_SIZ_FULL)
594		length = master->size - offset;
595
596	if (length <= 0)
597		return -EINVAL;
598
599	part.name = name;
600	part.size = length;
601	part.offset = offset;
602	part.mask_flags = 0;
603	part.ecclayout = NULL;
604
605	new = allocate_partition(master, &part, -1, offset);
606	if (IS_ERR(new))
607		return PTR_ERR(new);
608
609	mutex_lock(&mtd_partitions_mutex);
610	list_add(&new->list, &mtd_partitions);
611	mutex_unlock(&mtd_partitions_mutex);
612
613	add_mtd_device(&new->mtd);
614
615	mtd_add_partition_attrs(new);
616
617	return ret;
618}
619EXPORT_SYMBOL_GPL(mtd_add_partition);
620
621int mtd_del_partition(struct mtd_info *master, int partno)
622{
623	struct mtd_part *slave, *next;
624	int ret = -EINVAL;
625
626	mutex_lock(&mtd_partitions_mutex);
627	list_for_each_entry_safe(slave, next, &mtd_partitions, list)
628		if ((slave->master == master) &&
629		    (slave->mtd.index == partno)) {
630			sysfs_remove_files(&slave->mtd.dev.kobj,
631					   mtd_partition_attrs);
632			ret = del_mtd_device(&slave->mtd);
633			if (ret < 0)
634				break;
635
636			list_del(&slave->list);
637			free_partition(slave);
638			break;
639		}
640	mutex_unlock(&mtd_partitions_mutex);
641
642	return ret;
643}
644EXPORT_SYMBOL_GPL(mtd_del_partition);
645
646/*
647 * This function, given a master MTD object and a partition table, creates
648 * and registers slave MTD objects which are bound to the master according to
649 * the partition definitions.
650 *
651 * For historical reasons, this function's caller only registers the master
652 * if the MTD_PARTITIONED_MASTER config option is set.
653 */
654
655int add_mtd_partitions(struct mtd_info *master,
656		       const struct mtd_partition *parts,
657		       int nbparts)
658{
659	struct mtd_part *slave;
660	uint64_t cur_offset = 0;
661	int i;
662
663	printk(KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);
664
665	for (i = 0; i < nbparts; i++) {
666		slave = allocate_partition(master, parts + i, i, cur_offset);
667		if (IS_ERR(slave))
668			return PTR_ERR(slave);
669
670		mutex_lock(&mtd_partitions_mutex);
671		list_add(&slave->list, &mtd_partitions);
672		mutex_unlock(&mtd_partitions_mutex);
673
674		add_mtd_device(&slave->mtd);
675		mtd_add_partition_attrs(slave);
676
677		cur_offset = slave->offset + slave->mtd.size;
678	}
679
680	return 0;
681}
682
683static DEFINE_SPINLOCK(part_parser_lock);
684static LIST_HEAD(part_parsers);
685
686static struct mtd_part_parser *get_partition_parser(const char *name)
687{
688	struct mtd_part_parser *p, *ret = NULL;
689
690	spin_lock(&part_parser_lock);
691
692	list_for_each_entry(p, &part_parsers, list)
693		if (!strcmp(p->name, name) && try_module_get(p->owner)) {
694			ret = p;
695			break;
696		}
697
698	spin_unlock(&part_parser_lock);
699
700	return ret;
701}
702
703#define put_partition_parser(p) do { module_put((p)->owner); } while (0)
704
705void register_mtd_parser(struct mtd_part_parser *p)
706{
707	spin_lock(&part_parser_lock);
708	list_add(&p->list, &part_parsers);
709	spin_unlock(&part_parser_lock);
710}
711EXPORT_SYMBOL_GPL(register_mtd_parser);
712
713void deregister_mtd_parser(struct mtd_part_parser *p)
714{
715	spin_lock(&part_parser_lock);
716	list_del(&p->list);
717	spin_unlock(&part_parser_lock);
718}
719EXPORT_SYMBOL_GPL(deregister_mtd_parser);
720
721/*
722 * Do not forget to update 'parse_mtd_partitions()' kerneldoc comment if you
723 * are changing this array!
724 */
725static const char * const default_mtd_part_types[] = {
726	"cmdlinepart",
727	"ofpart",
728	NULL
729};
730
731/**
732 * parse_mtd_partitions - parse MTD partitions
733 * @master: the master partition (describes whole MTD device)
734 * @types: names of partition parsers to try or %NULL
735 * @pparts: array of partitions found is returned here
736 * @data: MTD partition parser-specific data
737 *
738 * This function tries to find partition on MTD device @master. It uses MTD
739 * partition parsers, specified in @types. However, if @types is %NULL, then
740 * the default list of parsers is used. The default list contains only the
741 * "cmdlinepart" and "ofpart" parsers ATM.
742 * Note: If there are more then one parser in @types, the kernel only takes the
743 * partitions parsed out by the first parser.
744 *
745 * This function may return:
746 * o a negative error code in case of failure
747 * o zero if no partitions were found
748 * o a positive number of found partitions, in which case on exit @pparts will
749 *   point to an array containing this number of &struct mtd_info objects.
750 */
751int parse_mtd_partitions(struct mtd_info *master, const char *const *types,
752			 struct mtd_partition **pparts,
753			 struct mtd_part_parser_data *data)
754{
755	struct mtd_part_parser *parser;
756	int ret = 0;
757
758	if (!types)
759		types = default_mtd_part_types;
760
761	for ( ; ret <= 0 && *types; types++) {
762		parser = get_partition_parser(*types);
763		if (!parser && !request_module("%s", *types))
764			parser = get_partition_parser(*types);
765		if (!parser)
766			continue;
767		ret = (*parser->parse_fn)(master, pparts, data);
768		put_partition_parser(parser);
769		if (ret > 0) {
770			printk(KERN_NOTICE "%d %s partitions found on MTD device %s\n",
771			       ret, parser->name, master->name);
772			break;
773		}
774	}
775	return ret;
776}
777
778int mtd_is_partition(const struct mtd_info *mtd)
779{
780	struct mtd_part *part;
781	int ispart = 0;
782
783	mutex_lock(&mtd_partitions_mutex);
784	list_for_each_entry(part, &mtd_partitions, list)
785		if (&part->mtd == mtd) {
786			ispart = 1;
787			break;
788		}
789	mutex_unlock(&mtd_partitions_mutex);
790
791	return ispart;
792}
793EXPORT_SYMBOL_GPL(mtd_is_partition);
794
795/* Returns the size of the entire flash chip */
796uint64_t mtd_get_device_size(const struct mtd_info *mtd)
797{
798	if (!mtd_is_partition(mtd))
799		return mtd->size;
800
801	return PART(mtd)->master->size;
802}
803EXPORT_SYMBOL_GPL(mtd_get_device_size);
804