xref: /openbmc/u-boot/drivers/mtd/mtdpart.c (revision a353e6aa8ec8f0aa101cc7e9543fe7843ddc6d98)
1 // SPDX-License-Identifier: GPL-2.0+
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 
11 #ifndef __UBOOT__
12 #include <linux/module.h>
13 #include <linux/types.h>
14 #include <linux/kernel.h>
15 #include <linux/slab.h>
16 #include <linux/list.h>
17 #include <linux/kmod.h>
18 #endif
19 
20 #include <common.h>
21 #include <malloc.h>
22 #include <linux/errno.h>
23 #include <linux/compat.h>
24 #include <ubi_uboot.h>
25 
26 #include <linux/mtd/mtd.h>
27 #include <linux/mtd/partitions.h>
28 #include <linux/err.h>
29 
30 #include "mtdcore.h"
31 
32 /* Our partition linked list */
33 static LIST_HEAD(mtd_partitions);
34 #ifndef __UBOOT__
35 static DEFINE_MUTEX(mtd_partitions_mutex);
36 #else
37 DEFINE_MUTEX(mtd_partitions_mutex);
38 #endif
39 
40 /* Our partition node structure */
41 struct mtd_part {
42 	struct mtd_info mtd;
43 	struct mtd_info *master;
44 	uint64_t offset;
45 	struct list_head list;
46 };
47 
48 /*
49  * Given a pointer to the MTD object in the mtd_part structure, we can retrieve
50  * the pointer to that structure with this macro.
51  */
52 #define PART(x)  ((struct mtd_part *)(x))
53 
54 
55 #ifdef __UBOOT__
56 /* from mm/util.c */
57 
58 /**
59  * kstrdup - allocate space for and copy an existing string
60  * @s: the string to duplicate
61  * @gfp: the GFP mask used in the kmalloc() call when allocating memory
62  */
63 char *kstrdup(const char *s, gfp_t gfp)
64 {
65 	size_t len;
66 	char *buf;
67 
68 	if (!s)
69 		return NULL;
70 
71 	len = strlen(s) + 1;
72 	buf = kmalloc(len, gfp);
73 	if (buf)
74 		memcpy(buf, s, len);
75 	return buf;
76 }
77 #endif
78 
79 /*
80  * MTD methods which simply translate the effective address and pass through
81  * to the _real_ device.
82  */
83 
84 static int part_read(struct mtd_info *mtd, loff_t from, size_t len,
85 		size_t *retlen, u_char *buf)
86 {
87 	struct mtd_part *part = PART(mtd);
88 	struct mtd_ecc_stats stats;
89 	int res;
90 
91 	stats = part->master->ecc_stats;
92 	res = part->master->_read(part->master, from + part->offset, len,
93 				  retlen, buf);
94 	if (unlikely(mtd_is_eccerr(res)))
95 		mtd->ecc_stats.failed +=
96 			part->master->ecc_stats.failed - stats.failed;
97 	else
98 		mtd->ecc_stats.corrected +=
99 			part->master->ecc_stats.corrected - stats.corrected;
100 	return res;
101 }
102 
103 #ifndef __UBOOT__
104 static int part_point(struct mtd_info *mtd, loff_t from, size_t len,
105 		size_t *retlen, void **virt, resource_size_t *phys)
106 {
107 	struct mtd_part *part = PART(mtd);
108 
109 	return part->master->_point(part->master, from + part->offset, len,
110 				    retlen, virt, phys);
111 }
112 
113 static int part_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
114 {
115 	struct mtd_part *part = PART(mtd);
116 
117 	return part->master->_unpoint(part->master, from + part->offset, len);
118 }
119 #endif
120 
121 static unsigned long part_get_unmapped_area(struct mtd_info *mtd,
122 					    unsigned long len,
123 					    unsigned long offset,
124 					    unsigned long flags)
125 {
126 	struct mtd_part *part = PART(mtd);
127 
128 	offset += part->offset;
129 	return part->master->_get_unmapped_area(part->master, len, offset,
130 						flags);
131 }
132 
133 static int part_read_oob(struct mtd_info *mtd, loff_t from,
134 		struct mtd_oob_ops *ops)
135 {
136 	struct mtd_part *part = PART(mtd);
137 	int res;
138 
139 	if (from >= mtd->size)
140 		return -EINVAL;
141 	if (ops->datbuf && from + ops->len > mtd->size)
142 		return -EINVAL;
143 
144 	/*
145 	 * If OOB is also requested, make sure that we do not read past the end
146 	 * of this partition.
147 	 */
148 	if (ops->oobbuf) {
149 		size_t len, pages;
150 
151 		if (ops->mode == MTD_OPS_AUTO_OOB)
152 			len = mtd->oobavail;
153 		else
154 			len = mtd->oobsize;
155 		pages = mtd_div_by_ws(mtd->size, mtd);
156 		pages -= mtd_div_by_ws(from, mtd);
157 		if (ops->ooboffs + ops->ooblen > pages * len)
158 			return -EINVAL;
159 	}
160 
161 	res = part->master->_read_oob(part->master, from + part->offset, ops);
162 	if (unlikely(res)) {
163 		if (mtd_is_bitflip(res))
164 			mtd->ecc_stats.corrected++;
165 		if (mtd_is_eccerr(res))
166 			mtd->ecc_stats.failed++;
167 	}
168 	return res;
169 }
170 
171 static int part_read_user_prot_reg(struct mtd_info *mtd, loff_t from,
172 		size_t len, size_t *retlen, u_char *buf)
173 {
174 	struct mtd_part *part = PART(mtd);
175 	return part->master->_read_user_prot_reg(part->master, from, len,
176 						 retlen, buf);
177 }
178 
179 static int part_get_user_prot_info(struct mtd_info *mtd, size_t len,
180 				   size_t *retlen, struct otp_info *buf)
181 {
182 	struct mtd_part *part = PART(mtd);
183 	return part->master->_get_user_prot_info(part->master, len, retlen,
184 						 buf);
185 }
186 
187 static int part_read_fact_prot_reg(struct mtd_info *mtd, loff_t from,
188 		size_t len, size_t *retlen, u_char *buf)
189 {
190 	struct mtd_part *part = PART(mtd);
191 	return part->master->_read_fact_prot_reg(part->master, from, len,
192 						 retlen, buf);
193 }
194 
195 static int part_get_fact_prot_info(struct mtd_info *mtd, size_t len,
196 				   size_t *retlen, struct otp_info *buf)
197 {
198 	struct mtd_part *part = PART(mtd);
199 	return part->master->_get_fact_prot_info(part->master, len, retlen,
200 						 buf);
201 }
202 
203 static int part_write(struct mtd_info *mtd, loff_t to, size_t len,
204 		size_t *retlen, const u_char *buf)
205 {
206 	struct mtd_part *part = PART(mtd);
207 	return part->master->_write(part->master, to + part->offset, len,
208 				    retlen, buf);
209 }
210 
211 static int part_panic_write(struct mtd_info *mtd, loff_t to, size_t len,
212 		size_t *retlen, const u_char *buf)
213 {
214 	struct mtd_part *part = PART(mtd);
215 	return part->master->_panic_write(part->master, to + part->offset, len,
216 					  retlen, buf);
217 }
218 
219 static int part_write_oob(struct mtd_info *mtd, loff_t to,
220 		struct mtd_oob_ops *ops)
221 {
222 	struct mtd_part *part = PART(mtd);
223 
224 	if (to >= mtd->size)
225 		return -EINVAL;
226 	if (ops->datbuf && to + ops->len > mtd->size)
227 		return -EINVAL;
228 	return part->master->_write_oob(part->master, to + part->offset, ops);
229 }
230 
231 static int part_write_user_prot_reg(struct mtd_info *mtd, loff_t from,
232 		size_t len, size_t *retlen, u_char *buf)
233 {
234 	struct mtd_part *part = PART(mtd);
235 	return part->master->_write_user_prot_reg(part->master, from, len,
236 						  retlen, buf);
237 }
238 
239 static int part_lock_user_prot_reg(struct mtd_info *mtd, loff_t from,
240 		size_t len)
241 {
242 	struct mtd_part *part = PART(mtd);
243 	return part->master->_lock_user_prot_reg(part->master, from, len);
244 }
245 
246 #ifndef __UBOOT__
247 static int part_writev(struct mtd_info *mtd, const struct kvec *vecs,
248 		unsigned long count, loff_t to, size_t *retlen)
249 {
250 	struct mtd_part *part = PART(mtd);
251 	return part->master->_writev(part->master, vecs, count,
252 				     to + part->offset, retlen);
253 }
254 #endif
255 
256 static int part_erase(struct mtd_info *mtd, struct erase_info *instr)
257 {
258 	struct mtd_part *part = PART(mtd);
259 	int ret;
260 
261 	instr->addr += part->offset;
262 	ret = part->master->_erase(part->master, instr);
263 	if (ret) {
264 		if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
265 			instr->fail_addr -= part->offset;
266 		instr->addr -= part->offset;
267 	}
268 	return ret;
269 }
270 
271 void mtd_erase_callback(struct erase_info *instr)
272 {
273 	if (instr->mtd->_erase == part_erase) {
274 		struct mtd_part *part = PART(instr->mtd);
275 
276 		if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
277 			instr->fail_addr -= part->offset;
278 		instr->addr -= part->offset;
279 	}
280 	if (instr->callback)
281 		instr->callback(instr);
282 }
283 EXPORT_SYMBOL_GPL(mtd_erase_callback);
284 
285 static int part_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
286 {
287 	struct mtd_part *part = PART(mtd);
288 	return part->master->_lock(part->master, ofs + part->offset, len);
289 }
290 
291 static int part_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
292 {
293 	struct mtd_part *part = PART(mtd);
294 	return part->master->_unlock(part->master, ofs + part->offset, len);
295 }
296 
297 static int part_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
298 {
299 	struct mtd_part *part = PART(mtd);
300 	return part->master->_is_locked(part->master, ofs + part->offset, len);
301 }
302 
303 static void part_sync(struct mtd_info *mtd)
304 {
305 	struct mtd_part *part = PART(mtd);
306 	part->master->_sync(part->master);
307 }
308 
309 #ifndef __UBOOT__
310 static int part_suspend(struct mtd_info *mtd)
311 {
312 	struct mtd_part *part = PART(mtd);
313 	return part->master->_suspend(part->master);
314 }
315 
316 static void part_resume(struct mtd_info *mtd)
317 {
318 	struct mtd_part *part = PART(mtd);
319 	part->master->_resume(part->master);
320 }
321 #endif
322 
323 static int part_block_isreserved(struct mtd_info *mtd, loff_t ofs)
324 {
325 	struct mtd_part *part = PART(mtd);
326 	ofs += part->offset;
327 	return part->master->_block_isreserved(part->master, ofs);
328 }
329 
330 static int part_block_isbad(struct mtd_info *mtd, loff_t ofs)
331 {
332 	struct mtd_part *part = PART(mtd);
333 	ofs += part->offset;
334 	return part->master->_block_isbad(part->master, ofs);
335 }
336 
337 static int part_block_markbad(struct mtd_info *mtd, loff_t ofs)
338 {
339 	struct mtd_part *part = PART(mtd);
340 	int res;
341 
342 	ofs += part->offset;
343 	res = part->master->_block_markbad(part->master, ofs);
344 	if (!res)
345 		mtd->ecc_stats.badblocks++;
346 	return res;
347 }
348 
349 static inline void free_partition(struct mtd_part *p)
350 {
351 	kfree(p->mtd.name);
352 	kfree(p);
353 }
354 
355 /*
356  * This function unregisters and destroy all slave MTD objects which are
357  * attached to the given master MTD object.
358  */
359 
360 int del_mtd_partitions(struct mtd_info *master)
361 {
362 	struct mtd_part *slave, *next;
363 	int ret, err = 0;
364 
365 	debug("Deleting MTD partitions on \"%s\":\n", master->name);
366 
367 	mutex_lock(&mtd_partitions_mutex);
368 	list_for_each_entry_safe(slave, next, &mtd_partitions, list)
369 		if (slave->master == master) {
370 			ret = del_mtd_device(&slave->mtd);
371 			if (ret < 0) {
372 				err = ret;
373 				continue;
374 			}
375 			list_del(&slave->list);
376 			free_partition(slave);
377 		}
378 	mutex_unlock(&mtd_partitions_mutex);
379 
380 	return err;
381 }
382 
383 static struct mtd_part *allocate_partition(struct mtd_info *master,
384 			const struct mtd_partition *part, int partno,
385 			uint64_t cur_offset)
386 {
387 	struct mtd_part *slave;
388 	char *name;
389 
390 	/* allocate the partition structure */
391 	slave = kzalloc(sizeof(*slave), GFP_KERNEL);
392 	name = kstrdup(part->name, GFP_KERNEL);
393 	if (!name || !slave) {
394 		printk(KERN_ERR"memory allocation error while creating partitions for \"%s\"\n",
395 		       master->name);
396 		kfree(name);
397 		kfree(slave);
398 		return ERR_PTR(-ENOMEM);
399 	}
400 
401 	/* set up the MTD object for this partition */
402 	slave->mtd.type = master->type;
403 	slave->mtd.flags = master->flags & ~part->mask_flags;
404 	slave->mtd.size = part->size;
405 	slave->mtd.writesize = master->writesize;
406 	slave->mtd.writebufsize = master->writebufsize;
407 	slave->mtd.oobsize = master->oobsize;
408 	slave->mtd.oobavail = master->oobavail;
409 	slave->mtd.subpage_sft = master->subpage_sft;
410 
411 	slave->mtd.name = name;
412 	slave->mtd.owner = master->owner;
413 #ifndef __UBOOT__
414 	slave->mtd.backing_dev_info = master->backing_dev_info;
415 
416 	/* NOTE:  we don't arrange MTDs as a tree; it'd be error-prone
417 	 * to have the same data be in two different partitions.
418 	 */
419 	slave->mtd.dev.parent = master->dev.parent;
420 #endif
421 
422 	if (master->_read)
423 		slave->mtd._read = part_read;
424 	if (master->_write)
425 		slave->mtd._write = part_write;
426 
427 	if (master->_panic_write)
428 		slave->mtd._panic_write = part_panic_write;
429 
430 #ifndef __UBOOT__
431 	if (master->_point && master->_unpoint) {
432 		slave->mtd._point = part_point;
433 		slave->mtd._unpoint = part_unpoint;
434 	}
435 #endif
436 
437 	if (master->_get_unmapped_area)
438 		slave->mtd._get_unmapped_area = part_get_unmapped_area;
439 	if (master->_read_oob)
440 		slave->mtd._read_oob = part_read_oob;
441 	if (master->_write_oob)
442 		slave->mtd._write_oob = part_write_oob;
443 	if (master->_read_user_prot_reg)
444 		slave->mtd._read_user_prot_reg = part_read_user_prot_reg;
445 	if (master->_read_fact_prot_reg)
446 		slave->mtd._read_fact_prot_reg = part_read_fact_prot_reg;
447 	if (master->_write_user_prot_reg)
448 		slave->mtd._write_user_prot_reg = part_write_user_prot_reg;
449 	if (master->_lock_user_prot_reg)
450 		slave->mtd._lock_user_prot_reg = part_lock_user_prot_reg;
451 	if (master->_get_user_prot_info)
452 		slave->mtd._get_user_prot_info = part_get_user_prot_info;
453 	if (master->_get_fact_prot_info)
454 		slave->mtd._get_fact_prot_info = part_get_fact_prot_info;
455 	if (master->_sync)
456 		slave->mtd._sync = part_sync;
457 #ifndef __UBOOT__
458 	if (!partno && !master->dev.class && master->_suspend &&
459 	    master->_resume) {
460 			slave->mtd._suspend = part_suspend;
461 			slave->mtd._resume = part_resume;
462 	}
463 	if (master->_writev)
464 		slave->mtd._writev = part_writev;
465 #endif
466 	if (master->_lock)
467 		slave->mtd._lock = part_lock;
468 	if (master->_unlock)
469 		slave->mtd._unlock = part_unlock;
470 	if (master->_is_locked)
471 		slave->mtd._is_locked = part_is_locked;
472 	if (master->_block_isreserved)
473 		slave->mtd._block_isreserved = part_block_isreserved;
474 	if (master->_block_isbad)
475 		slave->mtd._block_isbad = part_block_isbad;
476 	if (master->_block_markbad)
477 		slave->mtd._block_markbad = part_block_markbad;
478 	slave->mtd._erase = part_erase;
479 	slave->master = master;
480 	slave->offset = part->offset;
481 
482 	if (slave->offset == MTDPART_OFS_APPEND)
483 		slave->offset = cur_offset;
484 	if (slave->offset == MTDPART_OFS_NXTBLK) {
485 		slave->offset = cur_offset;
486 		if (mtd_mod_by_eb(cur_offset, master) != 0) {
487 			/* Round up to next erasesize */
488 			slave->offset = (mtd_div_by_eb(cur_offset, master) + 1) * master->erasesize;
489 			debug("Moving partition %d: "
490 			       "0x%012llx -> 0x%012llx\n", partno,
491 			       (unsigned long long)cur_offset, (unsigned long long)slave->offset);
492 		}
493 	}
494 	if (slave->offset == MTDPART_OFS_RETAIN) {
495 		slave->offset = cur_offset;
496 		if (master->size - slave->offset >= slave->mtd.size) {
497 			slave->mtd.size = master->size - slave->offset
498 							- slave->mtd.size;
499 		} else {
500 			debug("mtd partition \"%s\" doesn't have enough space: %#llx < %#llx, disabled\n",
501 				part->name, master->size - slave->offset,
502 				slave->mtd.size);
503 			/* register to preserve ordering */
504 			goto out_register;
505 		}
506 	}
507 	if (slave->mtd.size == MTDPART_SIZ_FULL)
508 		slave->mtd.size = master->size - slave->offset;
509 
510 	debug("0x%012llx-0x%012llx : \"%s\"\n", (unsigned long long)slave->offset,
511 		(unsigned long long)(slave->offset + slave->mtd.size), slave->mtd.name);
512 
513 	/* let's do some sanity checks */
514 	if (slave->offset >= master->size) {
515 		/* let's register it anyway to preserve ordering */
516 		slave->offset = 0;
517 		slave->mtd.size = 0;
518 		printk(KERN_ERR"mtd: partition \"%s\" is out of reach -- disabled\n",
519 			part->name);
520 		goto out_register;
521 	}
522 	if (slave->offset + slave->mtd.size > master->size) {
523 		slave->mtd.size = master->size - slave->offset;
524 		printk(KERN_WARNING"mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#llx\n",
525 			part->name, master->name, (unsigned long long)slave->mtd.size);
526 	}
527 	if (master->numeraseregions > 1) {
528 		/* Deal with variable erase size stuff */
529 		int i, max = master->numeraseregions;
530 		u64 end = slave->offset + slave->mtd.size;
531 		struct mtd_erase_region_info *regions = master->eraseregions;
532 
533 		/* Find the first erase regions which is part of this
534 		 * partition. */
535 		for (i = 0; i < max && regions[i].offset <= slave->offset; i++)
536 			;
537 		/* The loop searched for the region _behind_ the first one */
538 		if (i > 0)
539 			i--;
540 
541 		/* Pick biggest erasesize */
542 		for (; i < max && regions[i].offset < end; i++) {
543 			if (slave->mtd.erasesize < regions[i].erasesize) {
544 				slave->mtd.erasesize = regions[i].erasesize;
545 			}
546 		}
547 		BUG_ON(slave->mtd.erasesize == 0);
548 	} else {
549 		/* Single erase size */
550 		slave->mtd.erasesize = master->erasesize;
551 	}
552 
553 	if ((slave->mtd.flags & MTD_WRITEABLE) &&
554 	    mtd_mod_by_eb(slave->offset, &slave->mtd)) {
555 		/* Doesn't start on a boundary of major erase size */
556 		/* FIXME: Let it be writable if it is on a boundary of
557 		 * _minor_ erase size though */
558 		slave->mtd.flags &= ~MTD_WRITEABLE;
559 		printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",
560 			part->name);
561 	}
562 	if ((slave->mtd.flags & MTD_WRITEABLE) &&
563 	    mtd_mod_by_eb(slave->mtd.size, &slave->mtd)) {
564 		slave->mtd.flags &= ~MTD_WRITEABLE;
565 		printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
566 			part->name);
567 	}
568 
569 	slave->mtd.ecclayout = master->ecclayout;
570 	slave->mtd.ecc_step_size = master->ecc_step_size;
571 	slave->mtd.ecc_strength = master->ecc_strength;
572 	slave->mtd.bitflip_threshold = master->bitflip_threshold;
573 
574 	if (master->_block_isbad) {
575 		uint64_t offs = 0;
576 
577 		while (offs < slave->mtd.size) {
578 			if (mtd_block_isbad(master, offs + slave->offset))
579 				slave->mtd.ecc_stats.badblocks++;
580 			offs += slave->mtd.erasesize;
581 		}
582 	}
583 
584 out_register:
585 	return slave;
586 }
587 
588 #ifndef __UBOOT__
589 int mtd_add_partition(struct mtd_info *master, const char *name,
590 		      long long offset, long long length)
591 {
592 	struct mtd_partition part;
593 	struct mtd_part *p, *new;
594 	uint64_t start, end;
595 	int ret = 0;
596 
597 	/* the direct offset is expected */
598 	if (offset == MTDPART_OFS_APPEND ||
599 	    offset == MTDPART_OFS_NXTBLK)
600 		return -EINVAL;
601 
602 	if (length == MTDPART_SIZ_FULL)
603 		length = master->size - offset;
604 
605 	if (length <= 0)
606 		return -EINVAL;
607 
608 	part.name = name;
609 	part.size = length;
610 	part.offset = offset;
611 	part.mask_flags = 0;
612 	part.ecclayout = NULL;
613 
614 	new = allocate_partition(master, &part, -1, offset);
615 	if (IS_ERR(new))
616 		return PTR_ERR(new);
617 
618 	start = offset;
619 	end = offset + length;
620 
621 	mutex_lock(&mtd_partitions_mutex);
622 	list_for_each_entry(p, &mtd_partitions, list)
623 		if (p->master == master) {
624 			if ((start >= p->offset) &&
625 			    (start < (p->offset + p->mtd.size)))
626 				goto err_inv;
627 
628 			if ((end >= p->offset) &&
629 			    (end < (p->offset + p->mtd.size)))
630 				goto err_inv;
631 		}
632 
633 	list_add(&new->list, &mtd_partitions);
634 	mutex_unlock(&mtd_partitions_mutex);
635 
636 	add_mtd_device(&new->mtd);
637 
638 	return ret;
639 err_inv:
640 	mutex_unlock(&mtd_partitions_mutex);
641 	free_partition(new);
642 	return -EINVAL;
643 }
644 EXPORT_SYMBOL_GPL(mtd_add_partition);
645 
646 int mtd_del_partition(struct mtd_info *master, int partno)
647 {
648 	struct mtd_part *slave, *next;
649 	int ret = -EINVAL;
650 
651 	mutex_lock(&mtd_partitions_mutex);
652 	list_for_each_entry_safe(slave, next, &mtd_partitions, list)
653 		if ((slave->master == master) &&
654 		    (slave->mtd.index == partno)) {
655 			ret = del_mtd_device(&slave->mtd);
656 			if (ret < 0)
657 				break;
658 
659 			list_del(&slave->list);
660 			free_partition(slave);
661 			break;
662 		}
663 	mutex_unlock(&mtd_partitions_mutex);
664 
665 	return ret;
666 }
667 EXPORT_SYMBOL_GPL(mtd_del_partition);
668 #endif
669 
670 /*
671  * This function, given a master MTD object and a partition table, creates
672  * and registers slave MTD objects which are bound to the master according to
673  * the partition definitions.
674  *
675  * We don't register the master, or expect the caller to have done so,
676  * for reasons of data integrity.
677  */
678 
679 int add_mtd_partitions(struct mtd_info *master,
680 		       const struct mtd_partition *parts,
681 		       int nbparts)
682 {
683 	struct mtd_part *slave;
684 	uint64_t cur_offset = 0;
685 	int i;
686 
687 #ifdef __UBOOT__
688 	/*
689 	 * Need to init the list here, since LIST_INIT() does not
690 	 * work on platforms where relocation has problems (like MIPS
691 	 * & PPC).
692 	 */
693 	if (mtd_partitions.next == NULL)
694 		INIT_LIST_HEAD(&mtd_partitions);
695 #endif
696 
697 	debug("Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);
698 
699 	for (i = 0; i < nbparts; i++) {
700 		slave = allocate_partition(master, parts + i, i, cur_offset);
701 		if (IS_ERR(slave))
702 			return PTR_ERR(slave);
703 
704 		mutex_lock(&mtd_partitions_mutex);
705 		list_add(&slave->list, &mtd_partitions);
706 		mutex_unlock(&mtd_partitions_mutex);
707 
708 		add_mtd_device(&slave->mtd);
709 
710 		cur_offset = slave->offset + slave->mtd.size;
711 	}
712 
713 	return 0;
714 }
715 
716 #ifndef __UBOOT__
717 static DEFINE_SPINLOCK(part_parser_lock);
718 static LIST_HEAD(part_parsers);
719 
720 static struct mtd_part_parser *get_partition_parser(const char *name)
721 {
722 	struct mtd_part_parser *p, *ret = NULL;
723 
724 	spin_lock(&part_parser_lock);
725 
726 	list_for_each_entry(p, &part_parsers, list)
727 		if (!strcmp(p->name, name) && try_module_get(p->owner)) {
728 			ret = p;
729 			break;
730 		}
731 
732 	spin_unlock(&part_parser_lock);
733 
734 	return ret;
735 }
736 
737 #define put_partition_parser(p) do { module_put((p)->owner); } while (0)
738 
739 void register_mtd_parser(struct mtd_part_parser *p)
740 {
741 	spin_lock(&part_parser_lock);
742 	list_add(&p->list, &part_parsers);
743 	spin_unlock(&part_parser_lock);
744 }
745 EXPORT_SYMBOL_GPL(register_mtd_parser);
746 
747 void deregister_mtd_parser(struct mtd_part_parser *p)
748 {
749 	spin_lock(&part_parser_lock);
750 	list_del(&p->list);
751 	spin_unlock(&part_parser_lock);
752 }
753 EXPORT_SYMBOL_GPL(deregister_mtd_parser);
754 
755 /*
756  * Do not forget to update 'parse_mtd_partitions()' kerneldoc comment if you
757  * are changing this array!
758  */
759 static const char * const default_mtd_part_types[] = {
760 	"cmdlinepart",
761 	"ofpart",
762 	NULL
763 };
764 
765 /**
766  * parse_mtd_partitions - parse MTD partitions
767  * @master: the master partition (describes whole MTD device)
768  * @types: names of partition parsers to try or %NULL
769  * @pparts: array of partitions found is returned here
770  * @data: MTD partition parser-specific data
771  *
772  * This function tries to find partition on MTD device @master. It uses MTD
773  * partition parsers, specified in @types. However, if @types is %NULL, then
774  * the default list of parsers is used. The default list contains only the
775  * "cmdlinepart" and "ofpart" parsers ATM.
776  * Note: If there are more then one parser in @types, the kernel only takes the
777  * partitions parsed out by the first parser.
778  *
779  * This function may return:
780  * o a negative error code in case of failure
781  * o zero if no partitions were found
782  * o a positive number of found partitions, in which case on exit @pparts will
783  *   point to an array containing this number of &struct mtd_info objects.
784  */
785 int parse_mtd_partitions(struct mtd_info *master, const char *const *types,
786 			 struct mtd_partition **pparts,
787 			 struct mtd_part_parser_data *data)
788 {
789 	struct mtd_part_parser *parser;
790 	int ret = 0;
791 
792 	if (!types)
793 		types = default_mtd_part_types;
794 
795 	for ( ; ret <= 0 && *types; types++) {
796 		parser = get_partition_parser(*types);
797 		if (!parser && !request_module("%s", *types))
798 			parser = get_partition_parser(*types);
799 		if (!parser)
800 			continue;
801 		ret = (*parser->parse_fn)(master, pparts, data);
802 		put_partition_parser(parser);
803 		if (ret > 0) {
804 			printk(KERN_NOTICE "%d %s partitions found on MTD device %s\n",
805 			       ret, parser->name, master->name);
806 			break;
807 		}
808 	}
809 	return ret;
810 }
811 #endif
812 
813 int mtd_is_partition(const struct mtd_info *mtd)
814 {
815 	struct mtd_part *part;
816 	int ispart = 0;
817 
818 	mutex_lock(&mtd_partitions_mutex);
819 	list_for_each_entry(part, &mtd_partitions, list)
820 		if (&part->mtd == mtd) {
821 			ispart = 1;
822 			break;
823 		}
824 	mutex_unlock(&mtd_partitions_mutex);
825 
826 	return ispart;
827 }
828 EXPORT_SYMBOL_GPL(mtd_is_partition);
829 
830 /* Returns the size of the entire flash chip */
831 uint64_t mtd_get_device_size(const struct mtd_info *mtd)
832 {
833 	if (!mtd_is_partition(mtd))
834 		return mtd->size;
835 
836 	return PART(mtd)->master->size;
837 }
838 EXPORT_SYMBOL_GPL(mtd_get_device_size);
839