xref: /linux/drivers/mtd/rfd_ftl.c (revision f2ee442115c9b6219083c019939a9cc0c9abb2f8)
1 /*
2  * rfd_ftl.c -- resident flash disk (flash translation layer)
3  *
4  * Copyright © 2005  Sean Young <sean@mess.org>
5  *
6  * This type of flash translation layer (FTL) is used by the Embedded BIOS
7  * by General Software. It is known as the Resident Flash Disk (RFD), see:
8  *
9  *	http://www.gensw.com/pages/prod/bios/rfd.htm
10  *
11  * based on ftl.c
12  */
13 
14 #include <linux/hdreg.h>
15 #include <linux/init.h>
16 #include <linux/mtd/blktrans.h>
17 #include <linux/mtd/mtd.h>
18 #include <linux/vmalloc.h>
19 #include <linux/slab.h>
20 #include <linux/jiffies.h>
21 #include <linux/module.h>
22 
23 #include <asm/types.h>
24 
25 static int block_size = 0;
26 module_param(block_size, int, 0);
27 MODULE_PARM_DESC(block_size, "Block size to use by RFD, defaults to erase unit size");
28 
29 #define PREFIX "rfd_ftl: "
30 
31 /* This major has been assigned by device@lanana.org */
32 #ifndef RFD_FTL_MAJOR
33 #define RFD_FTL_MAJOR		256
34 #endif
35 
36 /* Maximum number of partitions in an FTL region */
37 #define PART_BITS		4
38 
39 /* An erase unit should start with this value */
40 #define RFD_MAGIC		0x9193
41 
42 /* the second value is 0xffff or 0xffc8; function unknown */
43 
44 /* the third value is always 0xffff, ignored */
45 
46 /* next is an array of mapping for each corresponding sector */
47 #define HEADER_MAP_OFFSET	3
48 #define SECTOR_DELETED		0x0000
49 #define SECTOR_ZERO		0xfffe
50 #define SECTOR_FREE		0xffff
51 
52 #define SECTOR_SIZE		512
53 
54 #define SECTORS_PER_TRACK	63
55 
56 struct block {
57 	enum {
58 		BLOCK_OK,
59 		BLOCK_ERASING,
60 		BLOCK_ERASED,
61 		BLOCK_UNUSED,
62 		BLOCK_FAILED
63 	} state;
64 	int free_sectors;
65 	int used_sectors;
66 	int erases;
67 	u_long offset;
68 };
69 
70 struct partition {
71 	struct mtd_blktrans_dev mbd;
72 
73 	u_int block_size;		/* size of erase unit */
74 	u_int total_blocks;		/* number of erase units */
75 	u_int header_sectors_per_block;	/* header sectors in erase unit */
76 	u_int data_sectors_per_block;	/* data sectors in erase unit */
77 	u_int sector_count;		/* sectors in translated disk */
78 	u_int header_size;		/* bytes in header sector */
79 	int reserved_block;		/* block next up for reclaim */
80 	int current_block;		/* block to write to */
81 	u16 *header_cache;		/* cached header */
82 
83 	int is_reclaiming;
84 	int cylinders;
85 	int errors;
86 	u_long *sector_map;
87 	struct block *blocks;
88 };
89 
90 static int rfd_ftl_writesect(struct mtd_blktrans_dev *dev, u_long sector, char *buf);
91 
92 static int build_block_map(struct partition *part, int block_no)
93 {
94 	struct block *block = &part->blocks[block_no];
95 	int i;
96 
97 	block->offset = part->block_size * block_no;
98 
99 	if (le16_to_cpu(part->header_cache[0]) != RFD_MAGIC) {
100 		block->state = BLOCK_UNUSED;
101 		return -ENOENT;
102 	}
103 
104 	block->state = BLOCK_OK;
105 
106 	for (i=0; i<part->data_sectors_per_block; i++) {
107 		u16 entry;
108 
109 		entry = le16_to_cpu(part->header_cache[HEADER_MAP_OFFSET + i]);
110 
111 		if (entry == SECTOR_DELETED)
112 			continue;
113 
114 		if (entry == SECTOR_FREE) {
115 			block->free_sectors++;
116 			continue;
117 		}
118 
119 		if (entry == SECTOR_ZERO)
120 			entry = 0;
121 
122 		if (entry >= part->sector_count) {
123 			printk(KERN_WARNING PREFIX
124 				"'%s': unit #%d: entry %d corrupt, "
125 				"sector %d out of range\n",
126 				part->mbd.mtd->name, block_no, i, entry);
127 			continue;
128 		}
129 
130 		if (part->sector_map[entry] != -1) {
131 			printk(KERN_WARNING PREFIX
132 				"'%s': more than one entry for sector %d\n",
133 				part->mbd.mtd->name, entry);
134 			part->errors = 1;
135 			continue;
136 		}
137 
138 		part->sector_map[entry] = block->offset +
139 			(i + part->header_sectors_per_block) * SECTOR_SIZE;
140 
141 		block->used_sectors++;
142 	}
143 
144 	if (block->free_sectors == part->data_sectors_per_block)
145 		part->reserved_block = block_no;
146 
147 	return 0;
148 }
149 
150 static int scan_header(struct partition *part)
151 {
152 	int sectors_per_block;
153 	int i, rc = -ENOMEM;
154 	int blocks_found;
155 	size_t retlen;
156 
157 	sectors_per_block = part->block_size / SECTOR_SIZE;
158 	part->total_blocks = (u32)part->mbd.mtd->size / part->block_size;
159 
160 	if (part->total_blocks < 2)
161 		return -ENOENT;
162 
163 	/* each erase block has three bytes header, followed by the map */
164 	part->header_sectors_per_block =
165 			((HEADER_MAP_OFFSET + sectors_per_block) *
166 			sizeof(u16) + SECTOR_SIZE - 1) / SECTOR_SIZE;
167 
168 	part->data_sectors_per_block = sectors_per_block -
169 			part->header_sectors_per_block;
170 
171 	part->header_size = (HEADER_MAP_OFFSET +
172 			part->data_sectors_per_block) * sizeof(u16);
173 
174 	part->cylinders = (part->data_sectors_per_block *
175 			(part->total_blocks - 1) - 1) / SECTORS_PER_TRACK;
176 
177 	part->sector_count = part->cylinders * SECTORS_PER_TRACK;
178 
179 	part->current_block = -1;
180 	part->reserved_block = -1;
181 	part->is_reclaiming = 0;
182 
183 	part->header_cache = kmalloc(part->header_size, GFP_KERNEL);
184 	if (!part->header_cache)
185 		goto err;
186 
187 	part->blocks = kcalloc(part->total_blocks, sizeof(struct block),
188 			GFP_KERNEL);
189 	if (!part->blocks)
190 		goto err;
191 
192 	part->sector_map = vmalloc(part->sector_count * sizeof(u_long));
193 	if (!part->sector_map) {
194 		printk(KERN_ERR PREFIX "'%s': unable to allocate memory for "
195 			"sector map", part->mbd.mtd->name);
196 		goto err;
197 	}
198 
199 	for (i=0; i<part->sector_count; i++)
200 		part->sector_map[i] = -1;
201 
202 	for (i=0, blocks_found=0; i<part->total_blocks; i++) {
203 		rc = part->mbd.mtd->read(part->mbd.mtd,
204 				i * part->block_size, part->header_size,
205 				&retlen, (u_char*)part->header_cache);
206 
207 		if (!rc && retlen != part->header_size)
208 			rc = -EIO;
209 
210 		if (rc)
211 			goto err;
212 
213 		if (!build_block_map(part, i))
214 			blocks_found++;
215 	}
216 
217 	if (blocks_found == 0) {
218 		printk(KERN_NOTICE PREFIX "no RFD magic found in '%s'\n",
219 				part->mbd.mtd->name);
220 		rc = -ENOENT;
221 		goto err;
222 	}
223 
224 	if (part->reserved_block == -1) {
225 		printk(KERN_WARNING PREFIX "'%s': no empty erase unit found\n",
226 				part->mbd.mtd->name);
227 
228 		part->errors = 1;
229 	}
230 
231 	return 0;
232 
233 err:
234 	vfree(part->sector_map);
235 	kfree(part->header_cache);
236 	kfree(part->blocks);
237 
238 	return rc;
239 }
240 
241 static int rfd_ftl_readsect(struct mtd_blktrans_dev *dev, u_long sector, char *buf)
242 {
243 	struct partition *part = (struct partition*)dev;
244 	u_long addr;
245 	size_t retlen;
246 	int rc;
247 
248 	if (sector >= part->sector_count)
249 		return -EIO;
250 
251 	addr = part->sector_map[sector];
252 	if (addr != -1) {
253 		rc = part->mbd.mtd->read(part->mbd.mtd, addr, SECTOR_SIZE,
254 						&retlen, (u_char*)buf);
255 		if (!rc && retlen != SECTOR_SIZE)
256 			rc = -EIO;
257 
258 		if (rc) {
259 			printk(KERN_WARNING PREFIX "error reading '%s' at "
260 				"0x%lx\n", part->mbd.mtd->name, addr);
261 			return rc;
262 		}
263 	} else
264 		memset(buf, 0, SECTOR_SIZE);
265 
266 	return 0;
267 }
268 
269 static void erase_callback(struct erase_info *erase)
270 {
271 	struct partition *part;
272 	u16 magic;
273 	int i, rc;
274 	size_t retlen;
275 
276 	part = (struct partition*)erase->priv;
277 
278 	i = (u32)erase->addr / part->block_size;
279 	if (i >= part->total_blocks || part->blocks[i].offset != erase->addr ||
280 	    erase->addr > UINT_MAX) {
281 		printk(KERN_ERR PREFIX "erase callback for unknown offset %llx "
282 				"on '%s'\n", (unsigned long long)erase->addr, part->mbd.mtd->name);
283 		return;
284 	}
285 
286 	if (erase->state != MTD_ERASE_DONE) {
287 		printk(KERN_WARNING PREFIX "erase failed at 0x%llx on '%s', "
288 				"state %d\n", (unsigned long long)erase->addr,
289 				part->mbd.mtd->name, erase->state);
290 
291 		part->blocks[i].state = BLOCK_FAILED;
292 		part->blocks[i].free_sectors = 0;
293 		part->blocks[i].used_sectors = 0;
294 
295 		kfree(erase);
296 
297 		return;
298 	}
299 
300 	magic = cpu_to_le16(RFD_MAGIC);
301 
302 	part->blocks[i].state = BLOCK_ERASED;
303 	part->blocks[i].free_sectors = part->data_sectors_per_block;
304 	part->blocks[i].used_sectors = 0;
305 	part->blocks[i].erases++;
306 
307 	rc = part->mbd.mtd->write(part->mbd.mtd,
308 		part->blocks[i].offset, sizeof(magic), &retlen,
309 		(u_char*)&magic);
310 
311 	if (!rc && retlen != sizeof(magic))
312 		rc = -EIO;
313 
314 	if (rc) {
315 		printk(KERN_ERR PREFIX "'%s': unable to write RFD "
316 				"header at 0x%lx\n",
317 				part->mbd.mtd->name,
318 				part->blocks[i].offset);
319 		part->blocks[i].state = BLOCK_FAILED;
320 	}
321 	else
322 		part->blocks[i].state = BLOCK_OK;
323 
324 	kfree(erase);
325 }
326 
327 static int erase_block(struct partition *part, int block)
328 {
329 	struct erase_info *erase;
330 	int rc = -ENOMEM;
331 
332 	erase = kmalloc(sizeof(struct erase_info), GFP_KERNEL);
333 	if (!erase)
334 		goto err;
335 
336 	erase->mtd = part->mbd.mtd;
337 	erase->callback = erase_callback;
338 	erase->addr = part->blocks[block].offset;
339 	erase->len = part->block_size;
340 	erase->priv = (u_long)part;
341 
342 	part->blocks[block].state = BLOCK_ERASING;
343 	part->blocks[block].free_sectors = 0;
344 
345 	rc = part->mbd.mtd->erase(part->mbd.mtd, erase);
346 
347 	if (rc) {
348 		printk(KERN_ERR PREFIX "erase of region %llx,%llx on '%s' "
349 				"failed\n", (unsigned long long)erase->addr,
350 				(unsigned long long)erase->len, part->mbd.mtd->name);
351 		kfree(erase);
352 	}
353 
354 err:
355 	return rc;
356 }
357 
358 static int move_block_contents(struct partition *part, int block_no, u_long *old_sector)
359 {
360 	void *sector_data;
361 	u16 *map;
362 	size_t retlen;
363 	int i, rc = -ENOMEM;
364 
365 	part->is_reclaiming = 1;
366 
367 	sector_data = kmalloc(SECTOR_SIZE, GFP_KERNEL);
368 	if (!sector_data)
369 		goto err3;
370 
371 	map = kmalloc(part->header_size, GFP_KERNEL);
372 	if (!map)
373 		goto err2;
374 
375 	rc = part->mbd.mtd->read(part->mbd.mtd,
376 		part->blocks[block_no].offset, part->header_size,
377 		&retlen, (u_char*)map);
378 
379 	if (!rc && retlen != part->header_size)
380 		rc = -EIO;
381 
382 	if (rc) {
383 		printk(KERN_ERR PREFIX "error reading '%s' at "
384 			"0x%lx\n", part->mbd.mtd->name,
385 			part->blocks[block_no].offset);
386 
387 		goto err;
388 	}
389 
390 	for (i=0; i<part->data_sectors_per_block; i++) {
391 		u16 entry = le16_to_cpu(map[HEADER_MAP_OFFSET + i]);
392 		u_long addr;
393 
394 
395 		if (entry == SECTOR_FREE || entry == SECTOR_DELETED)
396 			continue;
397 
398 		if (entry == SECTOR_ZERO)
399 			entry = 0;
400 
401 		/* already warned about and ignored in build_block_map() */
402 		if (entry >= part->sector_count)
403 			continue;
404 
405 		addr = part->blocks[block_no].offset +
406 			(i + part->header_sectors_per_block) * SECTOR_SIZE;
407 
408 		if (*old_sector == addr) {
409 			*old_sector = -1;
410 			if (!part->blocks[block_no].used_sectors--) {
411 				rc = erase_block(part, block_no);
412 				break;
413 			}
414 			continue;
415 		}
416 		rc = part->mbd.mtd->read(part->mbd.mtd, addr,
417 			SECTOR_SIZE, &retlen, sector_data);
418 
419 		if (!rc && retlen != SECTOR_SIZE)
420 			rc = -EIO;
421 
422 		if (rc) {
423 			printk(KERN_ERR PREFIX "'%s': Unable to "
424 				"read sector for relocation\n",
425 				part->mbd.mtd->name);
426 
427 			goto err;
428 		}
429 
430 		rc = rfd_ftl_writesect((struct mtd_blktrans_dev*)part,
431 				entry, sector_data);
432 
433 		if (rc)
434 			goto err;
435 	}
436 
437 err:
438 	kfree(map);
439 err2:
440 	kfree(sector_data);
441 err3:
442 	part->is_reclaiming = 0;
443 
444 	return rc;
445 }
446 
447 static int reclaim_block(struct partition *part, u_long *old_sector)
448 {
449 	int block, best_block, score, old_sector_block;
450 	int rc;
451 
452 	/* we have a race if sync doesn't exist */
453 	if (part->mbd.mtd->sync)
454 		part->mbd.mtd->sync(part->mbd.mtd);
455 
456 	score = 0x7fffffff; /* MAX_INT */
457 	best_block = -1;
458 	if (*old_sector != -1)
459 		old_sector_block = *old_sector / part->block_size;
460 	else
461 		old_sector_block = -1;
462 
463 	for (block=0; block<part->total_blocks; block++) {
464 		int this_score;
465 
466 		if (block == part->reserved_block)
467 			continue;
468 
469 		/*
470 		 * Postpone reclaiming if there is a free sector as
471 		 * more removed sectors is more efficient (have to move
472 		 * less).
473 		 */
474 		if (part->blocks[block].free_sectors)
475 			return 0;
476 
477 		this_score = part->blocks[block].used_sectors;
478 
479 		if (block == old_sector_block)
480 			this_score--;
481 		else {
482 			/* no point in moving a full block */
483 			if (part->blocks[block].used_sectors ==
484 					part->data_sectors_per_block)
485 				continue;
486 		}
487 
488 		this_score += part->blocks[block].erases;
489 
490 		if (this_score < score) {
491 			best_block = block;
492 			score = this_score;
493 		}
494 	}
495 
496 	if (best_block == -1)
497 		return -ENOSPC;
498 
499 	part->current_block = -1;
500 	part->reserved_block = best_block;
501 
502 	pr_debug("reclaim_block: reclaiming block #%d with %d used "
503 		 "%d free sectors\n", best_block,
504 		 part->blocks[best_block].used_sectors,
505 		 part->blocks[best_block].free_sectors);
506 
507 	if (part->blocks[best_block].used_sectors)
508 		rc = move_block_contents(part, best_block, old_sector);
509 	else
510 		rc = erase_block(part, best_block);
511 
512 	return rc;
513 }
514 
515 /*
516  * IMPROVE: It would be best to choose the block with the most deleted sectors,
517  * because if we fill that one up first it'll have the most chance of having
518  * the least live sectors at reclaim.
519  */
520 static int find_free_block(struct partition *part)
521 {
522 	int block, stop;
523 
524 	block = part->current_block == -1 ?
525 			jiffies % part->total_blocks : part->current_block;
526 	stop = block;
527 
528 	do {
529 		if (part->blocks[block].free_sectors &&
530 				block != part->reserved_block)
531 			return block;
532 
533 		if (part->blocks[block].state == BLOCK_UNUSED)
534 			erase_block(part, block);
535 
536 		if (++block >= part->total_blocks)
537 			block = 0;
538 
539 	} while (block != stop);
540 
541 	return -1;
542 }
543 
544 static int find_writable_block(struct partition *part, u_long *old_sector)
545 {
546 	int rc, block;
547 	size_t retlen;
548 
549 	block = find_free_block(part);
550 
551 	if (block == -1) {
552 		if (!part->is_reclaiming) {
553 			rc = reclaim_block(part, old_sector);
554 			if (rc)
555 				goto err;
556 
557 			block = find_free_block(part);
558 		}
559 
560 		if (block == -1) {
561 			rc = -ENOSPC;
562 			goto err;
563 		}
564 	}
565 
566 	rc = part->mbd.mtd->read(part->mbd.mtd, part->blocks[block].offset,
567 		part->header_size, &retlen, (u_char*)part->header_cache);
568 
569 	if (!rc && retlen != part->header_size)
570 		rc = -EIO;
571 
572 	if (rc) {
573 		printk(KERN_ERR PREFIX "'%s': unable to read header at "
574 				"0x%lx\n", part->mbd.mtd->name,
575 				part->blocks[block].offset);
576 		goto err;
577 	}
578 
579 	part->current_block = block;
580 
581 err:
582 	return rc;
583 }
584 
585 static int mark_sector_deleted(struct partition *part, u_long old_addr)
586 {
587 	int block, offset, rc;
588 	u_long addr;
589 	size_t retlen;
590 	u16 del = cpu_to_le16(SECTOR_DELETED);
591 
592 	block = old_addr / part->block_size;
593 	offset = (old_addr % part->block_size) / SECTOR_SIZE -
594 		part->header_sectors_per_block;
595 
596 	addr = part->blocks[block].offset +
597 			(HEADER_MAP_OFFSET + offset) * sizeof(u16);
598 	rc = part->mbd.mtd->write(part->mbd.mtd, addr,
599 		sizeof(del), &retlen, (u_char*)&del);
600 
601 	if (!rc && retlen != sizeof(del))
602 		rc = -EIO;
603 
604 	if (rc) {
605 		printk(KERN_ERR PREFIX "error writing '%s' at "
606 			"0x%lx\n", part->mbd.mtd->name, addr);
607 		if (rc)
608 			goto err;
609 	}
610 	if (block == part->current_block)
611 		part->header_cache[offset + HEADER_MAP_OFFSET] = del;
612 
613 	part->blocks[block].used_sectors--;
614 
615 	if (!part->blocks[block].used_sectors &&
616 	    !part->blocks[block].free_sectors)
617 		rc = erase_block(part, block);
618 
619 err:
620 	return rc;
621 }
622 
623 static int find_free_sector(const struct partition *part, const struct block *block)
624 {
625 	int i, stop;
626 
627 	i = stop = part->data_sectors_per_block - block->free_sectors;
628 
629 	do {
630 		if (le16_to_cpu(part->header_cache[HEADER_MAP_OFFSET + i])
631 				== SECTOR_FREE)
632 			return i;
633 
634 		if (++i == part->data_sectors_per_block)
635 			i = 0;
636 	}
637 	while(i != stop);
638 
639 	return -1;
640 }
641 
642 static int do_writesect(struct mtd_blktrans_dev *dev, u_long sector, char *buf, ulong *old_addr)
643 {
644 	struct partition *part = (struct partition*)dev;
645 	struct block *block;
646 	u_long addr;
647 	int i;
648 	int rc;
649 	size_t retlen;
650 	u16 entry;
651 
652 	if (part->current_block == -1 ||
653 		!part->blocks[part->current_block].free_sectors) {
654 
655 		rc = find_writable_block(part, old_addr);
656 		if (rc)
657 			goto err;
658 	}
659 
660 	block = &part->blocks[part->current_block];
661 
662 	i = find_free_sector(part, block);
663 
664 	if (i < 0) {
665 		rc = -ENOSPC;
666 		goto err;
667 	}
668 
669 	addr = (i + part->header_sectors_per_block) * SECTOR_SIZE +
670 		block->offset;
671 	rc = part->mbd.mtd->write(part->mbd.mtd,
672 		addr, SECTOR_SIZE, &retlen, (u_char*)buf);
673 
674 	if (!rc && retlen != SECTOR_SIZE)
675 		rc = -EIO;
676 
677 	if (rc) {
678 		printk(KERN_ERR PREFIX "error writing '%s' at 0x%lx\n",
679 				part->mbd.mtd->name, addr);
680 		if (rc)
681 			goto err;
682 	}
683 
684 	part->sector_map[sector] = addr;
685 
686 	entry = cpu_to_le16(sector == 0 ? SECTOR_ZERO : sector);
687 
688 	part->header_cache[i + HEADER_MAP_OFFSET] = entry;
689 
690 	addr = block->offset + (HEADER_MAP_OFFSET + i) * sizeof(u16);
691 	rc = part->mbd.mtd->write(part->mbd.mtd, addr,
692 			sizeof(entry), &retlen, (u_char*)&entry);
693 
694 	if (!rc && retlen != sizeof(entry))
695 		rc = -EIO;
696 
697 	if (rc) {
698 		printk(KERN_ERR PREFIX "error writing '%s' at 0x%lx\n",
699 				part->mbd.mtd->name, addr);
700 		if (rc)
701 			goto err;
702 	}
703 	block->used_sectors++;
704 	block->free_sectors--;
705 
706 err:
707 	return rc;
708 }
709 
710 static int rfd_ftl_writesect(struct mtd_blktrans_dev *dev, u_long sector, char *buf)
711 {
712 	struct partition *part = (struct partition*)dev;
713 	u_long old_addr;
714 	int i;
715 	int rc = 0;
716 
717 	pr_debug("rfd_ftl_writesect(sector=0x%lx)\n", sector);
718 
719 	if (part->reserved_block == -1) {
720 		rc = -EACCES;
721 		goto err;
722 	}
723 
724 	if (sector >= part->sector_count) {
725 		rc = -EIO;
726 		goto err;
727 	}
728 
729 	old_addr = part->sector_map[sector];
730 
731 	for (i=0; i<SECTOR_SIZE; i++) {
732 		if (!buf[i])
733 			continue;
734 
735 		rc = do_writesect(dev, sector, buf, &old_addr);
736 		if (rc)
737 			goto err;
738 		break;
739 	}
740 
741 	if (i == SECTOR_SIZE)
742 		part->sector_map[sector] = -1;
743 
744 	if (old_addr != -1)
745 		rc = mark_sector_deleted(part, old_addr);
746 
747 err:
748 	return rc;
749 }
750 
751 static int rfd_ftl_getgeo(struct mtd_blktrans_dev *dev, struct hd_geometry *geo)
752 {
753 	struct partition *part = (struct partition*)dev;
754 
755 	geo->heads = 1;
756 	geo->sectors = SECTORS_PER_TRACK;
757 	geo->cylinders = part->cylinders;
758 
759 	return 0;
760 }
761 
762 static void rfd_ftl_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
763 {
764 	struct partition *part;
765 
766 	if (mtd->type != MTD_NORFLASH || mtd->size > UINT_MAX)
767 		return;
768 
769 	part = kzalloc(sizeof(struct partition), GFP_KERNEL);
770 	if (!part)
771 		return;
772 
773 	part->mbd.mtd = mtd;
774 
775 	if (block_size)
776 		part->block_size = block_size;
777 	else {
778 		if (!mtd->erasesize) {
779 			printk(KERN_WARNING PREFIX "please provide block_size");
780 			goto out;
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.tr = tr;
788 		part->mbd.devnum = -1;
789 		if (!(mtd->flags & MTD_WRITEABLE))
790 			part->mbd.readonly = 1;
791 		else if (part->errors) {
792 			printk(KERN_WARNING PREFIX "'%s': errors found, "
793 					"setting read-only\n", mtd->name);
794 			part->mbd.readonly = 1;
795 		}
796 
797 		printk(KERN_INFO PREFIX "name: '%s' type: %d flags %x\n",
798 				mtd->name, mtd->type, mtd->flags);
799 
800 		if (!add_mtd_blktrans_dev((void*)part))
801 			return;
802 	}
803 out:
804 	kfree(part);
805 }
806 
807 static void rfd_ftl_remove_dev(struct mtd_blktrans_dev *dev)
808 {
809 	struct partition *part = (struct partition*)dev;
810 	int i;
811 
812 	for (i=0; i<part->total_blocks; i++) {
813 		pr_debug("rfd_ftl_remove_dev:'%s': erase unit #%02d: %d erases\n",
814 			part->mbd.mtd->name, i, part->blocks[i].erases);
815 	}
816 
817 	del_mtd_blktrans_dev(dev);
818 	vfree(part->sector_map);
819 	kfree(part->header_cache);
820 	kfree(part->blocks);
821 }
822 
823 static struct mtd_blktrans_ops rfd_ftl_tr = {
824 	.name		= "rfd",
825 	.major		= RFD_FTL_MAJOR,
826 	.part_bits	= PART_BITS,
827 	.blksize 	= SECTOR_SIZE,
828 
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