xref: /openbmc/linux/drivers/mtd/rfd_ftl.c (revision 545e4006)
1 /*
2  * rfd_ftl.c -- resident flash disk (flash translation layer)
3  *
4  * Copyright (C) 2005  Sean Young <sean@mess.org>
5  *
6  * $Id: rfd_ftl.c,v 1.8 2006/01/15 12:51:44 sean Exp $
7  *
8  * This type of flash translation layer (FTL) is used by the Embedded BIOS
9  * by General Software. It is known as the Resident Flash Disk (RFD), see:
10  *
11  *	http://www.gensw.com/pages/prod/bios/rfd.htm
12  *
13  * based on ftl.c
14  */
15 
16 #include <linux/hdreg.h>
17 #include <linux/init.h>
18 #include <linux/mtd/blktrans.h>
19 #include <linux/mtd/mtd.h>
20 #include <linux/vmalloc.h>
21 #include <linux/slab.h>
22 #include <linux/jiffies.h>
23 
24 #include <asm/types.h>
25 
26 #define const_cpu_to_le16	__constant_cpu_to_le16
27 
28 static int block_size = 0;
29 module_param(block_size, int, 0);
30 MODULE_PARM_DESC(block_size, "Block size to use by RFD, defaults to erase unit size");
31 
32 #define PREFIX "rfd_ftl: "
33 
34 /* This major has been assigned by device@lanana.org */
35 #ifndef RFD_FTL_MAJOR
36 #define RFD_FTL_MAJOR		256
37 #endif
38 
39 /* Maximum number of partitions in an FTL region */
40 #define PART_BITS		4
41 
42 /* An erase unit should start with this value */
43 #define RFD_MAGIC		0x9193
44 
45 /* the second value is 0xffff or 0xffc8; function unknown */
46 
47 /* the third value is always 0xffff, ignored */
48 
49 /* next is an array of mapping for each corresponding sector */
50 #define HEADER_MAP_OFFSET	3
51 #define SECTOR_DELETED		0x0000
52 #define SECTOR_ZERO		0xfffe
53 #define SECTOR_FREE		0xffff
54 
55 #define SECTOR_SIZE		512
56 
57 #define SECTORS_PER_TRACK	63
58 
59 struct block {
60 	enum {
61 		BLOCK_OK,
62 		BLOCK_ERASING,
63 		BLOCK_ERASED,
64 		BLOCK_UNUSED,
65 		BLOCK_FAILED
66 	} state;
67 	int free_sectors;
68 	int used_sectors;
69 	int erases;
70 	u_long offset;
71 };
72 
73 struct partition {
74 	struct mtd_blktrans_dev mbd;
75 
76 	u_int block_size;		/* size of erase unit */
77 	u_int total_blocks;		/* number of erase units */
78 	u_int header_sectors_per_block;	/* header sectors in erase unit */
79 	u_int data_sectors_per_block;	/* data sectors in erase unit */
80 	u_int sector_count;		/* sectors in translated disk */
81 	u_int header_size;		/* bytes in header sector */
82 	int reserved_block;		/* block next up for reclaim */
83 	int current_block;		/* block to write to */
84 	u16 *header_cache;		/* cached header */
85 
86 	int is_reclaiming;
87 	int cylinders;
88 	int errors;
89 	u_long *sector_map;
90 	struct block *blocks;
91 };
92 
93 static int rfd_ftl_writesect(struct mtd_blktrans_dev *dev, u_long sector, char *buf);
94 
95 static int build_block_map(struct partition *part, int block_no)
96 {
97 	struct block *block = &part->blocks[block_no];
98 	int i;
99 
100 	block->offset = part->block_size * block_no;
101 
102 	if (le16_to_cpu(part->header_cache[0]) != RFD_MAGIC) {
103 		block->state = BLOCK_UNUSED;
104 		return -ENOENT;
105 	}
106 
107 	block->state = BLOCK_OK;
108 
109 	for (i=0; i<part->data_sectors_per_block; i++) {
110 		u16 entry;
111 
112 		entry = le16_to_cpu(part->header_cache[HEADER_MAP_OFFSET + i]);
113 
114 		if (entry == SECTOR_DELETED)
115 			continue;
116 
117 		if (entry == SECTOR_FREE) {
118 			block->free_sectors++;
119 			continue;
120 		}
121 
122 		if (entry == SECTOR_ZERO)
123 			entry = 0;
124 
125 		if (entry >= part->sector_count) {
126 			printk(KERN_WARNING PREFIX
127 				"'%s': unit #%d: entry %d corrupt, "
128 				"sector %d out of range\n",
129 				part->mbd.mtd->name, block_no, i, entry);
130 			continue;
131 		}
132 
133 		if (part->sector_map[entry] != -1) {
134 			printk(KERN_WARNING PREFIX
135 				"'%s': more than one entry for sector %d\n",
136 				part->mbd.mtd->name, entry);
137 			part->errors = 1;
138 			continue;
139 		}
140 
141 		part->sector_map[entry] = block->offset +
142 			(i + part->header_sectors_per_block) * SECTOR_SIZE;
143 
144 		block->used_sectors++;
145 	}
146 
147 	if (block->free_sectors == part->data_sectors_per_block)
148 		part->reserved_block = block_no;
149 
150 	return 0;
151 }
152 
153 static int scan_header(struct partition *part)
154 {
155 	int sectors_per_block;
156 	int i, rc = -ENOMEM;
157 	int blocks_found;
158 	size_t retlen;
159 
160 	sectors_per_block = part->block_size / SECTOR_SIZE;
161 	part->total_blocks = part->mbd.mtd->size / part->block_size;
162 
163 	if (part->total_blocks < 2)
164 		return -ENOENT;
165 
166 	/* each erase block has three bytes header, followed by the map */
167 	part->header_sectors_per_block =
168 			((HEADER_MAP_OFFSET + sectors_per_block) *
169 			sizeof(u16) + SECTOR_SIZE - 1) / SECTOR_SIZE;
170 
171 	part->data_sectors_per_block = sectors_per_block -
172 			part->header_sectors_per_block;
173 
174 	part->header_size = (HEADER_MAP_OFFSET +
175 			part->data_sectors_per_block) * sizeof(u16);
176 
177 	part->cylinders = (part->data_sectors_per_block *
178 			(part->total_blocks - 1) - 1) / SECTORS_PER_TRACK;
179 
180 	part->sector_count = part->cylinders * SECTORS_PER_TRACK;
181 
182 	part->current_block = -1;
183 	part->reserved_block = -1;
184 	part->is_reclaiming = 0;
185 
186 	part->header_cache = kmalloc(part->header_size, GFP_KERNEL);
187 	if (!part->header_cache)
188 		goto err;
189 
190 	part->blocks = kcalloc(part->total_blocks, sizeof(struct block),
191 			GFP_KERNEL);
192 	if (!part->blocks)
193 		goto err;
194 
195 	part->sector_map = vmalloc(part->sector_count * sizeof(u_long));
196 	if (!part->sector_map) {
197 		printk(KERN_ERR PREFIX "'%s': unable to allocate memory for "
198 			"sector map", part->mbd.mtd->name);
199 		goto err;
200 	}
201 
202 	for (i=0; i<part->sector_count; i++)
203 		part->sector_map[i] = -1;
204 
205 	for (i=0, blocks_found=0; i<part->total_blocks; i++) {
206 		rc = part->mbd.mtd->read(part->mbd.mtd,
207 				i * part->block_size, part->header_size,
208 				&retlen, (u_char*)part->header_cache);
209 
210 		if (!rc && retlen != part->header_size)
211 			rc = -EIO;
212 
213 		if (rc)
214 			goto err;
215 
216 		if (!build_block_map(part, i))
217 			blocks_found++;
218 	}
219 
220 	if (blocks_found == 0) {
221 		printk(KERN_NOTICE PREFIX "no RFD magic found in '%s'\n",
222 				part->mbd.mtd->name);
223 		rc = -ENOENT;
224 		goto err;
225 	}
226 
227 	if (part->reserved_block == -1) {
228 		printk(KERN_WARNING PREFIX "'%s': no empty erase unit found\n",
229 				part->mbd.mtd->name);
230 
231 		part->errors = 1;
232 	}
233 
234 	return 0;
235 
236 err:
237 	vfree(part->sector_map);
238 	kfree(part->header_cache);
239 	kfree(part->blocks);
240 
241 	return rc;
242 }
243 
244 static int rfd_ftl_readsect(struct mtd_blktrans_dev *dev, u_long sector, char *buf)
245 {
246 	struct partition *part = (struct partition*)dev;
247 	u_long addr;
248 	size_t retlen;
249 	int rc;
250 
251 	if (sector >= part->sector_count)
252 		return -EIO;
253 
254 	addr = part->sector_map[sector];
255 	if (addr != -1) {
256 		rc = part->mbd.mtd->read(part->mbd.mtd, addr, SECTOR_SIZE,
257 						&retlen, (u_char*)buf);
258 		if (!rc && retlen != SECTOR_SIZE)
259 			rc = -EIO;
260 
261 		if (rc) {
262 			printk(KERN_WARNING PREFIX "error reading '%s' at "
263 				"0x%lx\n", part->mbd.mtd->name, addr);
264 			return rc;
265 		}
266 	} else
267 		memset(buf, 0, SECTOR_SIZE);
268 
269 	return 0;
270 }
271 
272 static void erase_callback(struct erase_info *erase)
273 {
274 	struct partition *part;
275 	u16 magic;
276 	int i, rc;
277 	size_t retlen;
278 
279 	part = (struct partition*)erase->priv;
280 
281 	i = erase->addr / part->block_size;
282 	if (i >= part->total_blocks || part->blocks[i].offset != erase->addr) {
283 		printk(KERN_ERR PREFIX "erase callback for unknown offset %x "
284 				"on '%s'\n", erase->addr, part->mbd.mtd->name);
285 		return;
286 	}
287 
288 	if (erase->state != MTD_ERASE_DONE) {
289 		printk(KERN_WARNING PREFIX "erase failed at 0x%x on '%s', "
290 				"state %d\n", erase->addr,
291 				part->mbd.mtd->name, erase->state);
292 
293 		part->blocks[i].state = BLOCK_FAILED;
294 		part->blocks[i].free_sectors = 0;
295 		part->blocks[i].used_sectors = 0;
296 
297 		kfree(erase);
298 
299 		return;
300 	}
301 
302 	magic = const_cpu_to_le16(RFD_MAGIC);
303 
304 	part->blocks[i].state = BLOCK_ERASED;
305 	part->blocks[i].free_sectors = part->data_sectors_per_block;
306 	part->blocks[i].used_sectors = 0;
307 	part->blocks[i].erases++;
308 
309 	rc = part->mbd.mtd->write(part->mbd.mtd,
310 		part->blocks[i].offset, sizeof(magic), &retlen,
311 		(u_char*)&magic);
312 
313 	if (!rc && retlen != sizeof(magic))
314 		rc = -EIO;
315 
316 	if (rc) {
317 		printk(KERN_ERR PREFIX "'%s': unable to write RFD "
318 				"header at 0x%lx\n",
319 				part->mbd.mtd->name,
320 				part->blocks[i].offset);
321 		part->blocks[i].state = BLOCK_FAILED;
322 	}
323 	else
324 		part->blocks[i].state = BLOCK_OK;
325 
326 	kfree(erase);
327 }
328 
329 static int erase_block(struct partition *part, int block)
330 {
331 	struct erase_info *erase;
332 	int rc = -ENOMEM;
333 
334 	erase = kmalloc(sizeof(struct erase_info), GFP_KERNEL);
335 	if (!erase)
336 		goto err;
337 
338 	erase->mtd = part->mbd.mtd;
339 	erase->callback = erase_callback;
340 	erase->addr = part->blocks[block].offset;
341 	erase->len = part->block_size;
342 	erase->priv = (u_long)part;
343 
344 	part->blocks[block].state = BLOCK_ERASING;
345 	part->blocks[block].free_sectors = 0;
346 
347 	rc = part->mbd.mtd->erase(part->mbd.mtd, erase);
348 
349 	if (rc) {
350 		printk(KERN_ERR PREFIX "erase of region %x,%x on '%s' "
351 				"failed\n", erase->addr, erase->len,
352 				part->mbd.mtd->name);
353 		kfree(erase);
354 	}
355 
356 err:
357 	return rc;
358 }
359 
360 static int move_block_contents(struct partition *part, int block_no, u_long *old_sector)
361 {
362 	void *sector_data;
363 	u16 *map;
364 	size_t retlen;
365 	int i, rc = -ENOMEM;
366 
367 	part->is_reclaiming = 1;
368 
369 	sector_data = kmalloc(SECTOR_SIZE, GFP_KERNEL);
370 	if (!sector_data)
371 		goto err3;
372 
373 	map = kmalloc(part->header_size, GFP_KERNEL);
374 	if (!map)
375 		goto err2;
376 
377 	rc = part->mbd.mtd->read(part->mbd.mtd,
378 		part->blocks[block_no].offset, part->header_size,
379 		&retlen, (u_char*)map);
380 
381 	if (!rc && retlen != part->header_size)
382 		rc = -EIO;
383 
384 	if (rc) {
385 		printk(KERN_ERR PREFIX "error reading '%s' at "
386 			"0x%lx\n", part->mbd.mtd->name,
387 			part->blocks[block_no].offset);
388 
389 		goto err;
390 	}
391 
392 	for (i=0; i<part->data_sectors_per_block; i++) {
393 		u16 entry = le16_to_cpu(map[HEADER_MAP_OFFSET + i]);
394 		u_long addr;
395 
396 
397 		if (entry == SECTOR_FREE || entry == SECTOR_DELETED)
398 			continue;
399 
400 		if (entry == SECTOR_ZERO)
401 			entry = 0;
402 
403 		/* already warned about and ignored in build_block_map() */
404 		if (entry >= part->sector_count)
405 			continue;
406 
407 		addr = part->blocks[block_no].offset +
408 			(i + part->header_sectors_per_block) * SECTOR_SIZE;
409 
410 		if (*old_sector == addr) {
411 			*old_sector = -1;
412 			if (!part->blocks[block_no].used_sectors--) {
413 				rc = erase_block(part, block_no);
414 				break;
415 			}
416 			continue;
417 		}
418 		rc = part->mbd.mtd->read(part->mbd.mtd, addr,
419 			SECTOR_SIZE, &retlen, sector_data);
420 
421 		if (!rc && retlen != SECTOR_SIZE)
422 			rc = -EIO;
423 
424 		if (rc) {
425 			printk(KERN_ERR PREFIX "'%s': Unable to "
426 				"read sector for relocation\n",
427 				part->mbd.mtd->name);
428 
429 			goto err;
430 		}
431 
432 		rc = rfd_ftl_writesect((struct mtd_blktrans_dev*)part,
433 				entry, sector_data);
434 
435 		if (rc)
436 			goto err;
437 	}
438 
439 err:
440 	kfree(map);
441 err2:
442 	kfree(sector_data);
443 err3:
444 	part->is_reclaiming = 0;
445 
446 	return rc;
447 }
448 
449 static int reclaim_block(struct partition *part, u_long *old_sector)
450 {
451 	int block, best_block, score, old_sector_block;
452 	int rc;
453 
454 	/* we have a race if sync doesn't exist */
455 	if (part->mbd.mtd->sync)
456 		part->mbd.mtd->sync(part->mbd.mtd);
457 
458 	score = 0x7fffffff; /* MAX_INT */
459 	best_block = -1;
460 	if (*old_sector != -1)
461 		old_sector_block = *old_sector / part->block_size;
462 	else
463 		old_sector_block = -1;
464 
465 	for (block=0; block<part->total_blocks; block++) {
466 		int this_score;
467 
468 		if (block == part->reserved_block)
469 			continue;
470 
471 		/*
472 		 * Postpone reclaiming if there is a free sector as
473 		 * more removed sectors is more efficient (have to move
474 		 * less).
475 		 */
476 		if (part->blocks[block].free_sectors)
477 			return 0;
478 
479 		this_score = part->blocks[block].used_sectors;
480 
481 		if (block == old_sector_block)
482 			this_score--;
483 		else {
484 			/* no point in moving a full block */
485 			if (part->blocks[block].used_sectors ==
486 					part->data_sectors_per_block)
487 				continue;
488 		}
489 
490 		this_score += part->blocks[block].erases;
491 
492 		if (this_score < score) {
493 			best_block = block;
494 			score = this_score;
495 		}
496 	}
497 
498 	if (best_block == -1)
499 		return -ENOSPC;
500 
501 	part->current_block = -1;
502 	part->reserved_block = best_block;
503 
504 	pr_debug("reclaim_block: reclaiming block #%d with %d used "
505 		 "%d free sectors\n", best_block,
506 		 part->blocks[best_block].used_sectors,
507 		 part->blocks[best_block].free_sectors);
508 
509 	if (part->blocks[best_block].used_sectors)
510 		rc = move_block_contents(part, best_block, old_sector);
511 	else
512 		rc = erase_block(part, best_block);
513 
514 	return rc;
515 }
516 
517 /*
518  * IMPROVE: It would be best to choose the block with the most deleted sectors,
519  * because if we fill that one up first it'll have the most chance of having
520  * the least live sectors at reclaim.
521  */
522 static int find_free_block(struct partition *part)
523 {
524 	int block, stop;
525 
526 	block = part->current_block == -1 ?
527 			jiffies % part->total_blocks : part->current_block;
528 	stop = block;
529 
530 	do {
531 		if (part->blocks[block].free_sectors &&
532 				block != part->reserved_block)
533 			return block;
534 
535 		if (part->blocks[block].state == BLOCK_UNUSED)
536 			erase_block(part, block);
537 
538 		if (++block >= part->total_blocks)
539 			block = 0;
540 
541 	} while (block != stop);
542 
543 	return -1;
544 }
545 
546 static int find_writable_block(struct partition *part, u_long *old_sector)
547 {
548 	int rc, block;
549 	size_t retlen;
550 
551 	block = find_free_block(part);
552 
553 	if (block == -1) {
554 		if (!part->is_reclaiming) {
555 			rc = reclaim_block(part, old_sector);
556 			if (rc)
557 				goto err;
558 
559 			block = find_free_block(part);
560 		}
561 
562 		if (block == -1) {
563 			rc = -ENOSPC;
564 			goto err;
565 		}
566 	}
567 
568 	rc = part->mbd.mtd->read(part->mbd.mtd, part->blocks[block].offset,
569 		part->header_size, &retlen, (u_char*)part->header_cache);
570 
571 	if (!rc && retlen != part->header_size)
572 		rc = -EIO;
573 
574 	if (rc) {
575 		printk(KERN_ERR PREFIX "'%s': unable to read header at "
576 				"0x%lx\n", part->mbd.mtd->name,
577 				part->blocks[block].offset);
578 		goto err;
579 	}
580 
581 	part->current_block = block;
582 
583 err:
584 	return rc;
585 }
586 
587 static int mark_sector_deleted(struct partition *part, u_long old_addr)
588 {
589 	int block, offset, rc;
590 	u_long addr;
591 	size_t retlen;
592 	u16 del = const_cpu_to_le16(SECTOR_DELETED);
593 
594 	block = old_addr / part->block_size;
595 	offset = (old_addr % part->block_size) / SECTOR_SIZE -
596 		part->header_sectors_per_block;
597 
598 	addr = part->blocks[block].offset +
599 			(HEADER_MAP_OFFSET + offset) * sizeof(u16);
600 	rc = part->mbd.mtd->write(part->mbd.mtd, addr,
601 		sizeof(del), &retlen, (u_char*)&del);
602 
603 	if (!rc && retlen != sizeof(del))
604 		rc = -EIO;
605 
606 	if (rc) {
607 		printk(KERN_ERR PREFIX "error writing '%s' at "
608 			"0x%lx\n", part->mbd.mtd->name, addr);
609 		if (rc)
610 			goto err;
611 	}
612 	if (block == part->current_block)
613 		part->header_cache[offset + HEADER_MAP_OFFSET] = del;
614 
615 	part->blocks[block].used_sectors--;
616 
617 	if (!part->blocks[block].used_sectors &&
618 	    !part->blocks[block].free_sectors)
619 		rc = erase_block(part, block);
620 
621 err:
622 	return rc;
623 }
624 
625 static int find_free_sector(const struct partition *part, const struct block *block)
626 {
627 	int i, stop;
628 
629 	i = stop = part->data_sectors_per_block - block->free_sectors;
630 
631 	do {
632 		if (le16_to_cpu(part->header_cache[HEADER_MAP_OFFSET + i])
633 				== SECTOR_FREE)
634 			return i;
635 
636 		if (++i == part->data_sectors_per_block)
637 			i = 0;
638 	}
639 	while(i != stop);
640 
641 	return -1;
642 }
643 
644 static int do_writesect(struct mtd_blktrans_dev *dev, u_long sector, char *buf, ulong *old_addr)
645 {
646 	struct partition *part = (struct partition*)dev;
647 	struct block *block;
648 	u_long addr;
649 	int i;
650 	int rc;
651 	size_t retlen;
652 	u16 entry;
653 
654 	if (part->current_block == -1 ||
655 		!part->blocks[part->current_block].free_sectors) {
656 
657 		rc = find_writable_block(part, old_addr);
658 		if (rc)
659 			goto err;
660 	}
661 
662 	block = &part->blocks[part->current_block];
663 
664 	i = find_free_sector(part, block);
665 
666 	if (i < 0) {
667 		rc = -ENOSPC;
668 		goto err;
669 	}
670 
671 	addr = (i + part->header_sectors_per_block) * SECTOR_SIZE +
672 		block->offset;
673 	rc = part->mbd.mtd->write(part->mbd.mtd,
674 		addr, SECTOR_SIZE, &retlen, (u_char*)buf);
675 
676 	if (!rc && retlen != SECTOR_SIZE)
677 		rc = -EIO;
678 
679 	if (rc) {
680 		printk(KERN_ERR PREFIX "error writing '%s' at 0x%lx\n",
681 				part->mbd.mtd->name, addr);
682 		if (rc)
683 			goto err;
684 	}
685 
686 	part->sector_map[sector] = addr;
687 
688 	entry = cpu_to_le16(sector == 0 ? SECTOR_ZERO : sector);
689 
690 	part->header_cache[i + HEADER_MAP_OFFSET] = entry;
691 
692 	addr = block->offset + (HEADER_MAP_OFFSET + i) * sizeof(u16);
693 	rc = part->mbd.mtd->write(part->mbd.mtd, addr,
694 			sizeof(entry), &retlen, (u_char*)&entry);
695 
696 	if (!rc && retlen != sizeof(entry))
697 		rc = -EIO;
698 
699 	if (rc) {
700 		printk(KERN_ERR PREFIX "error writing '%s' at 0x%lx\n",
701 				part->mbd.mtd->name, addr);
702 		if (rc)
703 			goto err;
704 	}
705 	block->used_sectors++;
706 	block->free_sectors--;
707 
708 err:
709 	return rc;
710 }
711 
712 static int rfd_ftl_writesect(struct mtd_blktrans_dev *dev, u_long sector, char *buf)
713 {
714 	struct partition *part = (struct partition*)dev;
715 	u_long old_addr;
716 	int i;
717 	int rc = 0;
718 
719 	pr_debug("rfd_ftl_writesect(sector=0x%lx)\n", sector);
720 
721 	if (part->reserved_block == -1) {
722 		rc = -EACCES;
723 		goto err;
724 	}
725 
726 	if (sector >= part->sector_count) {
727 		rc = -EIO;
728 		goto err;
729 	}
730 
731 	old_addr = part->sector_map[sector];
732 
733 	for (i=0; i<SECTOR_SIZE; i++) {
734 		if (!buf[i])
735 			continue;
736 
737 		rc = do_writesect(dev, sector, buf, &old_addr);
738 		if (rc)
739 			goto err;
740 		break;
741 	}
742 
743 	if (i == SECTOR_SIZE)
744 		part->sector_map[sector] = -1;
745 
746 	if (old_addr != -1)
747 		rc = mark_sector_deleted(part, old_addr);
748 
749 err:
750 	return rc;
751 }
752 
753 static int rfd_ftl_getgeo(struct mtd_blktrans_dev *dev, struct hd_geometry *geo)
754 {
755 	struct partition *part = (struct partition*)dev;
756 
757 	geo->heads = 1;
758 	geo->sectors = SECTORS_PER_TRACK;
759 	geo->cylinders = part->cylinders;
760 
761 	return 0;
762 }
763 
764 static void rfd_ftl_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
765 {
766 	struct partition *part;
767 
768 	if (mtd->type != MTD_NORFLASH)
769 		return;
770 
771 	part = kzalloc(sizeof(struct partition), GFP_KERNEL);
772 	if (!part)
773 		return;
774 
775 	part->mbd.mtd = mtd;
776 
777 	if (block_size)
778 		part->block_size = block_size;
779 	else {
780 		if (!mtd->erasesize) {
781 			printk(KERN_WARNING PREFIX "please provide block_size");
782 			goto out;
783 		} else
784 			part->block_size = mtd->erasesize;
785 	}
786 
787 	if (scan_header(part) == 0) {
788 		part->mbd.size = part->sector_count;
789 		part->mbd.tr = tr;
790 		part->mbd.devnum = -1;
791 		if (!(mtd->flags & MTD_WRITEABLE))
792 			part->mbd.readonly = 1;
793 		else if (part->errors) {
794 			printk(KERN_WARNING PREFIX "'%s': errors found, "
795 					"setting read-only\n", mtd->name);
796 			part->mbd.readonly = 1;
797 		}
798 
799 		printk(KERN_INFO PREFIX "name: '%s' type: %d flags %x\n",
800 				mtd->name, mtd->type, mtd->flags);
801 
802 		if (!add_mtd_blktrans_dev((void*)part))
803 			return;
804 	}
805 out:
806 	kfree(part);
807 }
808 
809 static void rfd_ftl_remove_dev(struct mtd_blktrans_dev *dev)
810 {
811 	struct partition *part = (struct partition*)dev;
812 	int i;
813 
814 	for (i=0; i<part->total_blocks; i++) {
815 		pr_debug("rfd_ftl_remove_dev:'%s': erase unit #%02d: %d erases\n",
816 			part->mbd.mtd->name, i, part->blocks[i].erases);
817 	}
818 
819 	del_mtd_blktrans_dev(dev);
820 	vfree(part->sector_map);
821 	kfree(part->header_cache);
822 	kfree(part->blocks);
823 	kfree(part);
824 }
825 
826 static struct mtd_blktrans_ops rfd_ftl_tr = {
827 	.name		= "rfd",
828 	.major		= RFD_FTL_MAJOR,
829 	.part_bits	= PART_BITS,
830 	.blksize 	= SECTOR_SIZE,
831 
832 	.readsect	= rfd_ftl_readsect,
833 	.writesect	= rfd_ftl_writesect,
834 	.getgeo		= rfd_ftl_getgeo,
835 	.add_mtd	= rfd_ftl_add_mtd,
836 	.remove_dev	= rfd_ftl_remove_dev,
837 	.owner		= THIS_MODULE,
838 };
839 
840 static int __init init_rfd_ftl(void)
841 {
842 	return register_mtd_blktrans(&rfd_ftl_tr);
843 }
844 
845 static void __exit cleanup_rfd_ftl(void)
846 {
847 	deregister_mtd_blktrans(&rfd_ftl_tr);
848 }
849 
850 module_init(init_rfd_ftl);
851 module_exit(cleanup_rfd_ftl);
852 
853 MODULE_LICENSE("GPL");
854 MODULE_AUTHOR("Sean Young <sean@mess.org>");
855 MODULE_DESCRIPTION("Support code for RFD Flash Translation Layer, "
856 		"used by General Software's Embedded BIOS");
857 
858