xref: /openbmc/linux/drivers/mtd/mtdpart.c (revision b04b4f78)
1 /*
2  * Simple MTD partitioning layer
3  *
4  * (C) 2000 Nicolas Pitre <nico@cam.org>
5  *
6  * This code is GPL
7  *
8  * 	02-21-2002	Thomas Gleixner <gleixner@autronix.de>
9  *			added support for read_oob, write_oob
10  */
11 
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 #include <linux/mtd/mtd.h>
19 #include <linux/mtd/partitions.h>
20 #include <linux/mtd/compatmac.h>
21 
22 /* Our partition linked list */
23 static LIST_HEAD(mtd_partitions);
24 
25 /* Our partition node structure */
26 struct mtd_part {
27 	struct mtd_info mtd;
28 	struct mtd_info *master;
29 	uint64_t offset;
30 	int index;
31 	struct list_head list;
32 	int registered;
33 };
34 
35 /*
36  * Given a pointer to the MTD object in the mtd_part structure, we can retrieve
37  * the pointer to that structure with this macro.
38  */
39 #define PART(x)  ((struct mtd_part *)(x))
40 
41 
42 /*
43  * MTD methods which simply translate the effective address and pass through
44  * to the _real_ device.
45  */
46 
47 static int part_read(struct mtd_info *mtd, loff_t from, size_t len,
48 		size_t *retlen, u_char *buf)
49 {
50 	struct mtd_part *part = PART(mtd);
51 	struct mtd_ecc_stats stats;
52 	int res;
53 
54 	stats = part->master->ecc_stats;
55 
56 	if (from >= mtd->size)
57 		len = 0;
58 	else if (from + len > mtd->size)
59 		len = mtd->size - from;
60 	res = part->master->read(part->master, from + part->offset,
61 				   len, retlen, buf);
62 	if (unlikely(res)) {
63 		if (res == -EUCLEAN)
64 			mtd->ecc_stats.corrected += part->master->ecc_stats.corrected - stats.corrected;
65 		if (res == -EBADMSG)
66 			mtd->ecc_stats.failed += part->master->ecc_stats.failed - stats.failed;
67 	}
68 	return res;
69 }
70 
71 static int part_point(struct mtd_info *mtd, loff_t from, size_t len,
72 		size_t *retlen, void **virt, resource_size_t *phys)
73 {
74 	struct mtd_part *part = PART(mtd);
75 	if (from >= mtd->size)
76 		len = 0;
77 	else if (from + len > mtd->size)
78 		len = mtd->size - from;
79 	return part->master->point (part->master, from + part->offset,
80 				    len, retlen, virt, phys);
81 }
82 
83 static void part_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
84 {
85 	struct mtd_part *part = PART(mtd);
86 
87 	part->master->unpoint(part->master, from + part->offset, len);
88 }
89 
90 static unsigned long part_get_unmapped_area(struct mtd_info *mtd,
91 					    unsigned long len,
92 					    unsigned long offset,
93 					    unsigned long flags)
94 {
95 	struct mtd_part *part = PART(mtd);
96 
97 	offset += part->offset;
98 	return part->master->get_unmapped_area(part->master, len, offset,
99 					       flags);
100 }
101 
102 static int part_read_oob(struct mtd_info *mtd, loff_t from,
103 		struct mtd_oob_ops *ops)
104 {
105 	struct mtd_part *part = PART(mtd);
106 	int res;
107 
108 	if (from >= mtd->size)
109 		return -EINVAL;
110 	if (ops->datbuf && from + ops->len > mtd->size)
111 		return -EINVAL;
112 	res = part->master->read_oob(part->master, from + part->offset, ops);
113 
114 	if (unlikely(res)) {
115 		if (res == -EUCLEAN)
116 			mtd->ecc_stats.corrected++;
117 		if (res == -EBADMSG)
118 			mtd->ecc_stats.failed++;
119 	}
120 	return res;
121 }
122 
123 static int part_read_user_prot_reg(struct mtd_info *mtd, loff_t from,
124 		size_t len, size_t *retlen, u_char *buf)
125 {
126 	struct mtd_part *part = PART(mtd);
127 	return part->master->read_user_prot_reg(part->master, from,
128 					len, retlen, buf);
129 }
130 
131 static int part_get_user_prot_info(struct mtd_info *mtd,
132 		struct otp_info *buf, size_t len)
133 {
134 	struct mtd_part *part = PART(mtd);
135 	return part->master->get_user_prot_info(part->master, buf, len);
136 }
137 
138 static int part_read_fact_prot_reg(struct mtd_info *mtd, loff_t from,
139 		size_t len, size_t *retlen, u_char *buf)
140 {
141 	struct mtd_part *part = PART(mtd);
142 	return part->master->read_fact_prot_reg(part->master, from,
143 					len, retlen, buf);
144 }
145 
146 static int part_get_fact_prot_info(struct mtd_info *mtd, struct otp_info *buf,
147 		size_t len)
148 {
149 	struct mtd_part *part = PART(mtd);
150 	return part->master->get_fact_prot_info(part->master, buf, len);
151 }
152 
153 static int part_write(struct mtd_info *mtd, loff_t to, size_t len,
154 		size_t *retlen, const u_char *buf)
155 {
156 	struct mtd_part *part = PART(mtd);
157 	if (!(mtd->flags & MTD_WRITEABLE))
158 		return -EROFS;
159 	if (to >= mtd->size)
160 		len = 0;
161 	else if (to + len > mtd->size)
162 		len = mtd->size - to;
163 	return part->master->write(part->master, to + part->offset,
164 				    len, retlen, buf);
165 }
166 
167 static int part_panic_write(struct mtd_info *mtd, loff_t to, size_t len,
168 		size_t *retlen, const u_char *buf)
169 {
170 	struct mtd_part *part = PART(mtd);
171 	if (!(mtd->flags & MTD_WRITEABLE))
172 		return -EROFS;
173 	if (to >= mtd->size)
174 		len = 0;
175 	else if (to + len > mtd->size)
176 		len = mtd->size - to;
177 	return part->master->panic_write(part->master, to + part->offset,
178 				    len, retlen, buf);
179 }
180 
181 static int part_write_oob(struct mtd_info *mtd, loff_t to,
182 		struct mtd_oob_ops *ops)
183 {
184 	struct mtd_part *part = PART(mtd);
185 
186 	if (!(mtd->flags & MTD_WRITEABLE))
187 		return -EROFS;
188 
189 	if (to >= mtd->size)
190 		return -EINVAL;
191 	if (ops->datbuf && to + ops->len > mtd->size)
192 		return -EINVAL;
193 	return part->master->write_oob(part->master, to + part->offset, ops);
194 }
195 
196 static int part_write_user_prot_reg(struct mtd_info *mtd, loff_t from,
197 		size_t len, size_t *retlen, u_char *buf)
198 {
199 	struct mtd_part *part = PART(mtd);
200 	return part->master->write_user_prot_reg(part->master, from,
201 					len, retlen, buf);
202 }
203 
204 static int part_lock_user_prot_reg(struct mtd_info *mtd, loff_t from,
205 		size_t len)
206 {
207 	struct mtd_part *part = PART(mtd);
208 	return part->master->lock_user_prot_reg(part->master, from, len);
209 }
210 
211 static int part_writev(struct mtd_info *mtd, const struct kvec *vecs,
212 		unsigned long count, loff_t to, size_t *retlen)
213 {
214 	struct mtd_part *part = PART(mtd);
215 	if (!(mtd->flags & MTD_WRITEABLE))
216 		return -EROFS;
217 	return part->master->writev(part->master, vecs, count,
218 					to + part->offset, retlen);
219 }
220 
221 static int part_erase(struct mtd_info *mtd, struct erase_info *instr)
222 {
223 	struct mtd_part *part = PART(mtd);
224 	int ret;
225 	if (!(mtd->flags & MTD_WRITEABLE))
226 		return -EROFS;
227 	if (instr->addr >= mtd->size)
228 		return -EINVAL;
229 	instr->addr += part->offset;
230 	ret = part->master->erase(part->master, instr);
231 	if (ret) {
232 		if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
233 			instr->fail_addr -= part->offset;
234 		instr->addr -= part->offset;
235 	}
236 	return ret;
237 }
238 
239 void mtd_erase_callback(struct erase_info *instr)
240 {
241 	if (instr->mtd->erase == part_erase) {
242 		struct mtd_part *part = PART(instr->mtd);
243 
244 		if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
245 			instr->fail_addr -= part->offset;
246 		instr->addr -= part->offset;
247 	}
248 	if (instr->callback)
249 		instr->callback(instr);
250 }
251 EXPORT_SYMBOL_GPL(mtd_erase_callback);
252 
253 static int part_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
254 {
255 	struct mtd_part *part = PART(mtd);
256 	if ((len + ofs) > mtd->size)
257 		return -EINVAL;
258 	return part->master->lock(part->master, ofs + part->offset, len);
259 }
260 
261 static int part_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
262 {
263 	struct mtd_part *part = PART(mtd);
264 	if ((len + ofs) > mtd->size)
265 		return -EINVAL;
266 	return part->master->unlock(part->master, ofs + part->offset, len);
267 }
268 
269 static void part_sync(struct mtd_info *mtd)
270 {
271 	struct mtd_part *part = PART(mtd);
272 	part->master->sync(part->master);
273 }
274 
275 static int part_suspend(struct mtd_info *mtd)
276 {
277 	struct mtd_part *part = PART(mtd);
278 	return part->master->suspend(part->master);
279 }
280 
281 static void part_resume(struct mtd_info *mtd)
282 {
283 	struct mtd_part *part = PART(mtd);
284 	part->master->resume(part->master);
285 }
286 
287 static int part_block_isbad(struct mtd_info *mtd, loff_t ofs)
288 {
289 	struct mtd_part *part = PART(mtd);
290 	if (ofs >= mtd->size)
291 		return -EINVAL;
292 	ofs += part->offset;
293 	return part->master->block_isbad(part->master, ofs);
294 }
295 
296 static int part_block_markbad(struct mtd_info *mtd, loff_t ofs)
297 {
298 	struct mtd_part *part = PART(mtd);
299 	int res;
300 
301 	if (!(mtd->flags & MTD_WRITEABLE))
302 		return -EROFS;
303 	if (ofs >= mtd->size)
304 		return -EINVAL;
305 	ofs += part->offset;
306 	res = part->master->block_markbad(part->master, ofs);
307 	if (!res)
308 		mtd->ecc_stats.badblocks++;
309 	return res;
310 }
311 
312 /*
313  * This function unregisters and destroy all slave MTD objects which are
314  * attached to the given master MTD object.
315  */
316 
317 int del_mtd_partitions(struct mtd_info *master)
318 {
319 	struct mtd_part *slave, *next;
320 
321 	list_for_each_entry_safe(slave, next, &mtd_partitions, list)
322 		if (slave->master == master) {
323 			list_del(&slave->list);
324 			if (slave->registered)
325 				del_mtd_device(&slave->mtd);
326 			kfree(slave);
327 		}
328 
329 	return 0;
330 }
331 EXPORT_SYMBOL(del_mtd_partitions);
332 
333 static struct mtd_part *add_one_partition(struct mtd_info *master,
334 		const struct mtd_partition *part, int partno,
335 		uint64_t cur_offset)
336 {
337 	struct mtd_part *slave;
338 
339 	/* allocate the partition structure */
340 	slave = kzalloc(sizeof(*slave), GFP_KERNEL);
341 	if (!slave) {
342 		printk(KERN_ERR"memory allocation error while creating partitions for \"%s\"\n",
343 			master->name);
344 		del_mtd_partitions(master);
345 		return NULL;
346 	}
347 	list_add(&slave->list, &mtd_partitions);
348 
349 	/* set up the MTD object for this partition */
350 	slave->mtd.type = master->type;
351 	slave->mtd.flags = master->flags & ~part->mask_flags;
352 	slave->mtd.size = part->size;
353 	slave->mtd.writesize = master->writesize;
354 	slave->mtd.oobsize = master->oobsize;
355 	slave->mtd.oobavail = master->oobavail;
356 	slave->mtd.subpage_sft = master->subpage_sft;
357 
358 	slave->mtd.name = part->name;
359 	slave->mtd.owner = master->owner;
360 	slave->mtd.backing_dev_info = master->backing_dev_info;
361 
362 	/* NOTE:  we don't arrange MTDs as a tree; it'd be error-prone
363 	 * to have the same data be in two different partitions.
364 	 */
365 	slave->mtd.dev.parent = master->dev.parent;
366 
367 	slave->mtd.read = part_read;
368 	slave->mtd.write = part_write;
369 
370 	if (master->panic_write)
371 		slave->mtd.panic_write = part_panic_write;
372 
373 	if (master->point && master->unpoint) {
374 		slave->mtd.point = part_point;
375 		slave->mtd.unpoint = part_unpoint;
376 	}
377 
378 	if (master->get_unmapped_area)
379 		slave->mtd.get_unmapped_area = part_get_unmapped_area;
380 	if (master->read_oob)
381 		slave->mtd.read_oob = part_read_oob;
382 	if (master->write_oob)
383 		slave->mtd.write_oob = part_write_oob;
384 	if (master->read_user_prot_reg)
385 		slave->mtd.read_user_prot_reg = part_read_user_prot_reg;
386 	if (master->read_fact_prot_reg)
387 		slave->mtd.read_fact_prot_reg = part_read_fact_prot_reg;
388 	if (master->write_user_prot_reg)
389 		slave->mtd.write_user_prot_reg = part_write_user_prot_reg;
390 	if (master->lock_user_prot_reg)
391 		slave->mtd.lock_user_prot_reg = part_lock_user_prot_reg;
392 	if (master->get_user_prot_info)
393 		slave->mtd.get_user_prot_info = part_get_user_prot_info;
394 	if (master->get_fact_prot_info)
395 		slave->mtd.get_fact_prot_info = part_get_fact_prot_info;
396 	if (master->sync)
397 		slave->mtd.sync = part_sync;
398 	if (!partno && master->suspend && master->resume) {
399 			slave->mtd.suspend = part_suspend;
400 			slave->mtd.resume = part_resume;
401 	}
402 	if (master->writev)
403 		slave->mtd.writev = part_writev;
404 	if (master->lock)
405 		slave->mtd.lock = part_lock;
406 	if (master->unlock)
407 		slave->mtd.unlock = part_unlock;
408 	if (master->block_isbad)
409 		slave->mtd.block_isbad = part_block_isbad;
410 	if (master->block_markbad)
411 		slave->mtd.block_markbad = part_block_markbad;
412 	slave->mtd.erase = part_erase;
413 	slave->master = master;
414 	slave->offset = part->offset;
415 	slave->index = partno;
416 
417 	if (slave->offset == MTDPART_OFS_APPEND)
418 		slave->offset = cur_offset;
419 	if (slave->offset == MTDPART_OFS_NXTBLK) {
420 		slave->offset = cur_offset;
421 		if (mtd_mod_by_eb(cur_offset, master) != 0) {
422 			/* Round up to next erasesize */
423 			slave->offset = (mtd_div_by_eb(cur_offset, master) + 1) * master->erasesize;
424 			printk(KERN_NOTICE "Moving partition %d: "
425 			       "0x%012llx -> 0x%012llx\n", partno,
426 			       (unsigned long long)cur_offset, (unsigned long long)slave->offset);
427 		}
428 	}
429 	if (slave->mtd.size == MTDPART_SIZ_FULL)
430 		slave->mtd.size = master->size - slave->offset;
431 
432 	printk(KERN_NOTICE "0x%012llx-0x%012llx : \"%s\"\n", (unsigned long long)slave->offset,
433 		(unsigned long long)(slave->offset + slave->mtd.size), slave->mtd.name);
434 
435 	/* let's do some sanity checks */
436 	if (slave->offset >= master->size) {
437 		/* let's register it anyway to preserve ordering */
438 		slave->offset = 0;
439 		slave->mtd.size = 0;
440 		printk(KERN_ERR"mtd: partition \"%s\" is out of reach -- disabled\n",
441 			part->name);
442 		goto out_register;
443 	}
444 	if (slave->offset + slave->mtd.size > master->size) {
445 		slave->mtd.size = master->size - slave->offset;
446 		printk(KERN_WARNING"mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#llx\n",
447 			part->name, master->name, (unsigned long long)slave->mtd.size);
448 	}
449 	if (master->numeraseregions > 1) {
450 		/* Deal with variable erase size stuff */
451 		int i, max = master->numeraseregions;
452 		u64 end = slave->offset + slave->mtd.size;
453 		struct mtd_erase_region_info *regions = master->eraseregions;
454 
455 		/* Find the first erase regions which is part of this
456 		 * partition. */
457 		for (i = 0; i < max && regions[i].offset <= slave->offset; i++)
458 			;
459 		/* The loop searched for the region _behind_ the first one */
460 		i--;
461 
462 		/* Pick biggest erasesize */
463 		for (; i < max && regions[i].offset < end; i++) {
464 			if (slave->mtd.erasesize < regions[i].erasesize) {
465 				slave->mtd.erasesize = regions[i].erasesize;
466 			}
467 		}
468 		BUG_ON(slave->mtd.erasesize == 0);
469 	} else {
470 		/* Single erase size */
471 		slave->mtd.erasesize = master->erasesize;
472 	}
473 
474 	if ((slave->mtd.flags & MTD_WRITEABLE) &&
475 	    mtd_mod_by_eb(slave->offset, &slave->mtd)) {
476 		/* Doesn't start on a boundary of major erase size */
477 		/* FIXME: Let it be writable if it is on a boundary of
478 		 * _minor_ erase size though */
479 		slave->mtd.flags &= ~MTD_WRITEABLE;
480 		printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",
481 			part->name);
482 	}
483 	if ((slave->mtd.flags & MTD_WRITEABLE) &&
484 	    mtd_mod_by_eb(slave->mtd.size, &slave->mtd)) {
485 		slave->mtd.flags &= ~MTD_WRITEABLE;
486 		printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
487 			part->name);
488 	}
489 
490 	slave->mtd.ecclayout = master->ecclayout;
491 	if (master->block_isbad) {
492 		uint64_t offs = 0;
493 
494 		while (offs < slave->mtd.size) {
495 			if (master->block_isbad(master,
496 						offs + slave->offset))
497 				slave->mtd.ecc_stats.badblocks++;
498 			offs += slave->mtd.erasesize;
499 		}
500 	}
501 
502 out_register:
503 	if (part->mtdp) {
504 		/* store the object pointer (caller may or may not register it*/
505 		*part->mtdp = &slave->mtd;
506 		slave->registered = 0;
507 	} else {
508 		/* register our partition */
509 		add_mtd_device(&slave->mtd);
510 		slave->registered = 1;
511 	}
512 	return slave;
513 }
514 
515 /*
516  * This function, given a master MTD object and a partition table, creates
517  * and registers slave MTD objects which are bound to the master according to
518  * the partition definitions.
519  *
520  * We don't register the master, or expect the caller to have done so,
521  * for reasons of data integrity.
522  */
523 
524 int add_mtd_partitions(struct mtd_info *master,
525 		       const struct mtd_partition *parts,
526 		       int nbparts)
527 {
528 	struct mtd_part *slave;
529 	uint64_t cur_offset = 0;
530 	int i;
531 
532 	printk(KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);
533 
534 	for (i = 0; i < nbparts; i++) {
535 		slave = add_one_partition(master, parts + i, i, cur_offset);
536 		if (!slave)
537 			return -ENOMEM;
538 		cur_offset = slave->offset + slave->mtd.size;
539 	}
540 
541 	return 0;
542 }
543 EXPORT_SYMBOL(add_mtd_partitions);
544 
545 static DEFINE_SPINLOCK(part_parser_lock);
546 static LIST_HEAD(part_parsers);
547 
548 static struct mtd_part_parser *get_partition_parser(const char *name)
549 {
550 	struct mtd_part_parser *p, *ret = NULL;
551 
552 	spin_lock(&part_parser_lock);
553 
554 	list_for_each_entry(p, &part_parsers, list)
555 		if (!strcmp(p->name, name) && try_module_get(p->owner)) {
556 			ret = p;
557 			break;
558 		}
559 
560 	spin_unlock(&part_parser_lock);
561 
562 	return ret;
563 }
564 
565 int register_mtd_parser(struct mtd_part_parser *p)
566 {
567 	spin_lock(&part_parser_lock);
568 	list_add(&p->list, &part_parsers);
569 	spin_unlock(&part_parser_lock);
570 
571 	return 0;
572 }
573 EXPORT_SYMBOL_GPL(register_mtd_parser);
574 
575 int deregister_mtd_parser(struct mtd_part_parser *p)
576 {
577 	spin_lock(&part_parser_lock);
578 	list_del(&p->list);
579 	spin_unlock(&part_parser_lock);
580 	return 0;
581 }
582 EXPORT_SYMBOL_GPL(deregister_mtd_parser);
583 
584 int parse_mtd_partitions(struct mtd_info *master, const char **types,
585 			 struct mtd_partition **pparts, unsigned long origin)
586 {
587 	struct mtd_part_parser *parser;
588 	int ret = 0;
589 
590 	for ( ; ret <= 0 && *types; types++) {
591 		parser = get_partition_parser(*types);
592 		if (!parser && !request_module("%s", *types))
593 				parser = get_partition_parser(*types);
594 		if (!parser) {
595 			printk(KERN_NOTICE "%s partition parsing not available\n",
596 			       *types);
597 			continue;
598 		}
599 		ret = (*parser->parse_fn)(master, pparts, origin);
600 		if (ret > 0) {
601 			printk(KERN_NOTICE "%d %s partitions found on MTD device %s\n",
602 			       ret, parser->name, master->name);
603 		}
604 		put_partition_parser(parser);
605 	}
606 	return ret;
607 }
608 EXPORT_SYMBOL_GPL(parse_mtd_partitions);
609