xref: /linux/drivers/mtd/rfd_ftl.c (revision 9ce7677cfd7cd871adb457c80bea3b581b839641)
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 1.5 2005/11/07 11:14:21 gleixner 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/jiffies.h>
22 
23 #include <asm/types.h>
24 
25 #define const_cpu_to_le16	__constant_cpu_to_le16
26 
27 static int block_size = 0;
28 module_param(block_size, int, 0);
29 MODULE_PARM_DESC(block_size, "Block size to use by RFD, defaults to erase unit size");
30 
31 #define PREFIX "rfd_ftl: "
32 
33 /* This major has been assigned by device@lanana.org */
34 #ifndef RFD_FTL_MAJOR
35 #define RFD_FTL_MAJOR		256
36 #endif
37 
38 /* Maximum number of partitions in an FTL region */
39 #define PART_BITS		4
40 
41 /* An erase unit should start with this value */
42 #define RFD_MAGIC		0x9193
43 
44 /* the second value is 0xffff or 0xffc8; function unknown */
45 
46 /* the third value is always 0xffff, ignored */
47 
48 /* next is an array of mapping for each corresponding sector */
49 #define HEADER_MAP_OFFSET	3
50 #define SECTOR_DELETED		0x0000
51 #define SECTOR_ZERO		0xfffe
52 #define SECTOR_FREE		0xffff
53 
54 #define SECTOR_SIZE		512
55 
56 #define SECTORS_PER_TRACK	63
57 
58 struct block {
59 	enum {
60 		BLOCK_OK,
61 		BLOCK_ERASING,
62 		BLOCK_ERASED,
63 		BLOCK_FAILED
64 	} state;
65 	int free_sectors;
66 	int used_sectors;
67 	int erases;
68 	u_long offset;
69 };
70 
71 struct partition {
72 	struct mtd_blktrans_dev mbd;
73 
74 	u_int block_size;		/* size of erase unit */
75 	u_int total_blocks;		/* number of erase units */
76 	u_int header_sectors_per_block;	/* header sectors in erase unit */
77 	u_int data_sectors_per_block;	/* data sectors in erase unit */
78 	u_int sector_count;		/* sectors in translated disk */
79 	u_int header_size;		/* bytes in header sector */
80 	int reserved_block;		/* block next up for reclaim */
81 	int current_block;		/* block to write to */
82 	u16 *header_cache;		/* cached header */
83 
84 	int is_reclaiming;
85 	int cylinders;
86 	int errors;
87 	u_long *sector_map;
88 	struct block *blocks;
89 };
90 
91 static int rfd_ftl_writesect(struct mtd_blktrans_dev *dev, u_long sector, char *buf);
92 
93 static int build_block_map(struct partition *part, int block_no)
94 {
95 	struct block *block = &part->blocks[block_no];
96 	int i;
97 
98 	block->offset = part->block_size * block_no;
99 
100 	if (le16_to_cpu(part->header_cache[0]) != RFD_MAGIC) {
101 		block->state = BLOCK_ERASED; /* assumption */
102 		block->free_sectors = part->data_sectors_per_block;
103 		part->reserved_block = block_no;
104 		return 1;
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_NOTICE 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_NOTICE 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_NOTICE 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_NOTICE 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_WARNING 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_NOTICE 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_NOTICE 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(const 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 (++block >= part->total_blocks)
536 			block = 0;
537 
538 	} while (block != stop);
539 
540 	return -1;
541 }
542 
543 static int find_writeable_block(struct partition *part, u_long *old_sector)
544 {
545 	int rc, block;
546 	size_t retlen;
547 
548 	block = find_free_block(part);
549 
550 	if (block == -1) {
551 		if (!part->is_reclaiming) {
552 			rc = reclaim_block(part, old_sector);
553 			if (rc)
554 				goto err;
555 
556 			block = find_free_block(part);
557 		}
558 
559 		if (block == -1) {
560 			rc = -ENOSPC;
561 			goto err;
562 		}
563 	}
564 
565 	rc = part->mbd.mtd->read(part->mbd.mtd, part->blocks[block].offset,
566 		part->header_size, &retlen, (u_char*)part->header_cache);
567 
568 	if (!rc && retlen != part->header_size)
569 		rc = -EIO;
570 
571 	if (rc) {
572 		printk(KERN_NOTICE PREFIX "'%s': unable to read header at "
573 				"0x%lx\n", part->mbd.mtd->name,
574 				part->blocks[block].offset);
575 		goto err;
576 	}
577 
578 	part->current_block = block;
579 
580 err:
581 	return rc;
582 }
583 
584 static int mark_sector_deleted(struct partition *part, u_long old_addr)
585 {
586 	int block, offset, rc;
587 	u_long addr;
588 	size_t retlen;
589 	u16 del = const_cpu_to_le16(SECTOR_DELETED);
590 
591 	block = old_addr / part->block_size;
592 	offset = (old_addr % part->block_size) / SECTOR_SIZE -
593 		part->header_sectors_per_block;
594 
595 	addr = part->blocks[block].offset +
596 			(HEADER_MAP_OFFSET + offset) * sizeof(u16);
597 	rc = part->mbd.mtd->write(part->mbd.mtd, addr,
598 		sizeof(del), &retlen, (u_char*)&del);
599 
600 	if (!rc && retlen != sizeof(del))
601 		rc = -EIO;
602 
603 	if (rc) {
604 		printk(KERN_WARNING PREFIX "error writing '%s' at "
605 			"0x%lx\n", part->mbd.mtd->name, addr);
606 		if (rc)
607 			goto err;
608 	}
609 	if (block == part->current_block)
610 		part->header_cache[offset + HEADER_MAP_OFFSET] = del;
611 
612 	part->blocks[block].used_sectors--;
613 
614 	if (!part->blocks[block].used_sectors &&
615 	    !part->blocks[block].free_sectors)
616 		rc = erase_block(part, block);
617 
618 err:
619 	return rc;
620 }
621 
622 static int find_free_sector(const struct partition *part, const struct block *block)
623 {
624 	int i, stop;
625 
626 	i = stop = part->data_sectors_per_block - block->free_sectors;
627 
628 	do {
629 		if (le16_to_cpu(part->header_cache[HEADER_MAP_OFFSET + i])
630 				== SECTOR_FREE)
631 			return i;
632 
633 		if (++i == part->data_sectors_per_block)
634 			i = 0;
635 	}
636 	while(i != stop);
637 
638 	return -1;
639 }
640 
641 static int do_writesect(struct mtd_blktrans_dev *dev, u_long sector, char *buf, ulong *old_addr)
642 {
643 	struct partition *part = (struct partition*)dev;
644 	struct block *block;
645 	u_long addr;
646 	int i;
647 	int rc;
648 	size_t retlen;
649 	u16 entry;
650 
651 	if (part->current_block == -1 ||
652 		!part->blocks[part->current_block].free_sectors) {
653 
654 		rc = find_writeable_block(part, old_addr);
655 		if (rc)
656 			goto err;
657 	}
658 
659 	block = &part->blocks[part->current_block];
660 
661 	i = find_free_sector(part, block);
662 
663 	if (i < 0) {
664 		rc = -ENOSPC;
665 		goto err;
666 	}
667 
668 	addr = (i + part->header_sectors_per_block) * SECTOR_SIZE +
669 		block->offset;
670 	rc = part->mbd.mtd->write(part->mbd.mtd,
671 		addr, SECTOR_SIZE, &retlen, (u_char*)buf);
672 
673 	if (!rc && retlen != SECTOR_SIZE)
674 		rc = -EIO;
675 
676 	if (rc) {
677 		printk(KERN_WARNING PREFIX "error writing '%s' at 0x%lx\n",
678 				part->mbd.mtd->name, addr);
679 		if (rc)
680 			goto err;
681 	}
682 
683 	part->sector_map[sector] = addr;
684 
685 	entry = cpu_to_le16(sector == 0 ? SECTOR_ZERO : sector);
686 
687 	part->header_cache[i + HEADER_MAP_OFFSET] = entry;
688 
689 	addr = block->offset + (HEADER_MAP_OFFSET + i) * sizeof(u16);
690 	rc = part->mbd.mtd->write(part->mbd.mtd, addr,
691 			sizeof(entry), &retlen, (u_char*)&entry);
692 
693 	if (!rc && retlen != sizeof(entry))
694 		rc = -EIO;
695 
696 	if (rc) {
697 		printk(KERN_WARNING PREFIX "error writing '%s' at 0x%lx\n",
698 				part->mbd.mtd->name, addr);
699 		if (rc)
700 			goto err;
701 	}
702 	block->used_sectors++;
703 	block->free_sectors--;
704 
705 err:
706 	return rc;
707 }
708 
709 static int rfd_ftl_writesect(struct mtd_blktrans_dev *dev, u_long sector, char *buf)
710 {
711 	struct partition *part = (struct partition*)dev;
712 	u_long old_addr;
713 	int i;
714 	int rc = 0;
715 
716 	pr_debug("rfd_ftl_writesect(sector=0x%lx)\n", sector);
717 
718 	if (part->reserved_block == -1) {
719 		rc = -EACCES;
720 		goto err;
721 	}
722 
723 	if (sector >= part->sector_count) {
724 		rc = -EIO;
725 		goto err;
726 	}
727 
728 	old_addr = part->sector_map[sector];
729 
730 	for (i=0; i<SECTOR_SIZE; i++) {
731 		if (!buf[i])
732 			continue;
733 
734 		rc = do_writesect(dev, sector, buf, &old_addr);
735 		if (rc)
736 			goto err;
737 		break;
738 	}
739 
740 	if (i == SECTOR_SIZE)
741 		part->sector_map[sector] = -1;
742 
743 	if (old_addr != -1)
744 		rc = mark_sector_deleted(part, old_addr);
745 
746 err:
747 	return rc;
748 }
749 
750 static int rfd_ftl_getgeo(struct mtd_blktrans_dev *dev, struct hd_geometry *geo)
751 {
752 	struct partition *part = (struct partition*)dev;
753 
754 	geo->heads = 1;
755 	geo->sectors = SECTORS_PER_TRACK;
756 	geo->cylinders = part->cylinders;
757 
758 	return 0;
759 }
760 
761 static void rfd_ftl_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
762 {
763 	struct partition *part;
764 
765 	if (mtd->type != MTD_NORFLASH)
766 		return;
767 
768 	part = kcalloc(1, sizeof(struct partition), GFP_KERNEL);
769 	if (!part)
770 		return;
771 
772 	part->mbd.mtd = mtd;
773 
774 	if (block_size)
775 		part->block_size = block_size;
776 	else {
777 		if (!mtd->erasesize) {
778 			printk(KERN_NOTICE PREFIX "please provide block_size");
779 			return;
780 		}
781 		else
782 			part->block_size = mtd->erasesize;
783 	}
784 
785 	if (scan_header(part) == 0) {
786 		part->mbd.size = part->sector_count;
787 		part->mbd.blksize = SECTOR_SIZE;
788 		part->mbd.tr = tr;
789 		part->mbd.devnum = -1;
790 		if (!(mtd->flags & MTD_WRITEABLE))
791 			part->mbd.readonly = 1;
792 		else if (part->errors) {
793 			printk(KERN_NOTICE PREFIX "'%s': errors found, "
794 					"setting read-only", mtd->name);
795 			part->mbd.readonly = 1;
796 		}
797 
798 		printk(KERN_INFO PREFIX "name: '%s' type: %d flags %x\n",
799 				mtd->name, mtd->type, mtd->flags);
800 
801 		if (!add_mtd_blktrans_dev((void*)part))
802 			return;
803 	}
804 
805 	kfree(part);
806 }
807 
808 static void rfd_ftl_remove_dev(struct mtd_blktrans_dev *dev)
809 {
810 	struct partition *part = (struct partition*)dev;
811 	int i;
812 
813 	for (i=0; i<part->total_blocks; i++) {
814 		pr_debug("rfd_ftl_remove_dev:'%s': erase unit #%02d: %d erases\n",
815 			part->mbd.mtd->name, i, part->blocks[i].erases);
816 	}
817 
818 	del_mtd_blktrans_dev(dev);
819 	vfree(part->sector_map);
820 	kfree(part->header_cache);
821 	kfree(part->blocks);
822 	kfree(part);
823 }
824 
825 struct mtd_blktrans_ops rfd_ftl_tr = {
826 	.name		= "rfd",
827 	.major		= RFD_FTL_MAJOR,
828 	.part_bits	= PART_BITS,
829 	.readsect	= rfd_ftl_readsect,
830 	.writesect	= rfd_ftl_writesect,
831 	.getgeo		= rfd_ftl_getgeo,
832 	.add_mtd	= rfd_ftl_add_mtd,
833 	.remove_dev	= rfd_ftl_remove_dev,
834 	.owner		= THIS_MODULE,
835 };
836 
837 static int __init init_rfd_ftl(void)
838 {
839 	return register_mtd_blktrans(&rfd_ftl_tr);
840 }
841 
842 static void __exit cleanup_rfd_ftl(void)
843 {
844 	deregister_mtd_blktrans(&rfd_ftl_tr);
845 }
846 
847 module_init(init_rfd_ftl);
848 module_exit(cleanup_rfd_ftl);
849 
850 MODULE_LICENSE("GPL");
851 MODULE_AUTHOR("Sean Young <sean@mess.org>");
852 MODULE_DESCRIPTION("Support code for RFD Flash Translation Layer, "
853 		"used by General Software's Embedded BIOS");
854 
855