xref: /linux/drivers/mtd/rfd_ftl.c (revision 60e13231561b3a4c5269bfa1ef6c0569ad6f28ec)
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 
22 #include <asm/types.h>
23 
24 static int block_size = 0;
25 module_param(block_size, int, 0);
26 MODULE_PARM_DESC(block_size, "Block size to use by RFD, defaults to erase unit size");
27 
28 #define PREFIX "rfd_ftl: "
29 
30 /* This major has been assigned by device@lanana.org */
31 #ifndef RFD_FTL_MAJOR
32 #define RFD_FTL_MAJOR		256
33 #endif
34 
35 /* Maximum number of partitions in an FTL region */
36 #define PART_BITS		4
37 
38 /* An erase unit should start with this value */
39 #define RFD_MAGIC		0x9193
40 
41 /* the second value is 0xffff or 0xffc8; function unknown */
42 
43 /* the third value is always 0xffff, ignored */
44 
45 /* next is an array of mapping for each corresponding sector */
46 #define HEADER_MAP_OFFSET	3
47 #define SECTOR_DELETED		0x0000
48 #define SECTOR_ZERO		0xfffe
49 #define SECTOR_FREE		0xffff
50 
51 #define SECTOR_SIZE		512
52 
53 #define SECTORS_PER_TRACK	63
54 
55 struct block {
56 	enum {
57 		BLOCK_OK,
58 		BLOCK_ERASING,
59 		BLOCK_ERASED,
60 		BLOCK_UNUSED,
61 		BLOCK_FAILED
62 	} state;
63 	int free_sectors;
64 	int used_sectors;
65 	int erases;
66 	u_long offset;
67 };
68 
69 struct partition {
70 	struct mtd_blktrans_dev mbd;
71 
72 	u_int block_size;		/* size of erase unit */
73 	u_int total_blocks;		/* number of erase units */
74 	u_int header_sectors_per_block;	/* header sectors in erase unit */
75 	u_int data_sectors_per_block;	/* data sectors in erase unit */
76 	u_int sector_count;		/* sectors in translated disk */
77 	u_int header_size;		/* bytes in header sector */
78 	int reserved_block;		/* block next up for reclaim */
79 	int current_block;		/* block to write to */
80 	u16 *header_cache;		/* cached header */
81 
82 	int is_reclaiming;
83 	int cylinders;
84 	int errors;
85 	u_long *sector_map;
86 	struct block *blocks;
87 };
88 
89 static int rfd_ftl_writesect(struct mtd_blktrans_dev *dev, u_long sector, char *buf);
90 
91 static int build_block_map(struct partition *part, int block_no)
92 {
93 	struct block *block = &part->blocks[block_no];
94 	int i;
95 
96 	block->offset = part->block_size * block_no;
97 
98 	if (le16_to_cpu(part->header_cache[0]) != RFD_MAGIC) {
99 		block->state = BLOCK_UNUSED;
100 		return -ENOENT;
101 	}
102 
103 	block->state = BLOCK_OK;
104 
105 	for (i=0; i<part->data_sectors_per_block; i++) {
106 		u16 entry;
107 
108 		entry = le16_to_cpu(part->header_cache[HEADER_MAP_OFFSET + i]);
109 
110 		if (entry == SECTOR_DELETED)
111 			continue;
112 
113 		if (entry == SECTOR_FREE) {
114 			block->free_sectors++;
115 			continue;
116 		}
117 
118 		if (entry == SECTOR_ZERO)
119 			entry = 0;
120 
121 		if (entry >= part->sector_count) {
122 			printk(KERN_WARNING PREFIX
123 				"'%s': unit #%d: entry %d corrupt, "
124 				"sector %d out of range\n",
125 				part->mbd.mtd->name, block_no, i, entry);
126 			continue;
127 		}
128 
129 		if (part->sector_map[entry] != -1) {
130 			printk(KERN_WARNING PREFIX
131 				"'%s': more than one entry for sector %d\n",
132 				part->mbd.mtd->name, entry);
133 			part->errors = 1;
134 			continue;
135 		}
136 
137 		part->sector_map[entry] = block->offset +
138 			(i + part->header_sectors_per_block) * SECTOR_SIZE;
139 
140 		block->used_sectors++;
141 	}
142 
143 	if (block->free_sectors == part->data_sectors_per_block)
144 		part->reserved_block = block_no;
145 
146 	return 0;
147 }
148 
149 static int scan_header(struct partition *part)
150 {
151 	int sectors_per_block;
152 	int i, rc = -ENOMEM;
153 	int blocks_found;
154 	size_t retlen;
155 
156 	sectors_per_block = part->block_size / SECTOR_SIZE;
157 	part->total_blocks = (u32)part->mbd.mtd->size / part->block_size;
158 
159 	if (part->total_blocks < 2)
160 		return -ENOENT;
161 
162 	/* each erase block has three bytes header, followed by the map */
163 	part->header_sectors_per_block =
164 			((HEADER_MAP_OFFSET + sectors_per_block) *
165 			sizeof(u16) + SECTOR_SIZE - 1) / SECTOR_SIZE;
166 
167 	part->data_sectors_per_block = sectors_per_block -
168 			part->header_sectors_per_block;
169 
170 	part->header_size = (HEADER_MAP_OFFSET +
171 			part->data_sectors_per_block) * sizeof(u16);
172 
173 	part->cylinders = (part->data_sectors_per_block *
174 			(part->total_blocks - 1) - 1) / SECTORS_PER_TRACK;
175 
176 	part->sector_count = part->cylinders * SECTORS_PER_TRACK;
177 
178 	part->current_block = -1;
179 	part->reserved_block = -1;
180 	part->is_reclaiming = 0;
181 
182 	part->header_cache = kmalloc(part->header_size, GFP_KERNEL);
183 	if (!part->header_cache)
184 		goto err;
185 
186 	part->blocks = kcalloc(part->total_blocks, sizeof(struct block),
187 			GFP_KERNEL);
188 	if (!part->blocks)
189 		goto err;
190 
191 	part->sector_map = vmalloc(part->sector_count * sizeof(u_long));
192 	if (!part->sector_map) {
193 		printk(KERN_ERR PREFIX "'%s': unable to allocate memory for "
194 			"sector map", part->mbd.mtd->name);
195 		goto err;
196 	}
197 
198 	for (i=0; i<part->sector_count; i++)
199 		part->sector_map[i] = -1;
200 
201 	for (i=0, blocks_found=0; i<part->total_blocks; i++) {
202 		rc = part->mbd.mtd->read(part->mbd.mtd,
203 				i * part->block_size, part->header_size,
204 				&retlen, (u_char*)part->header_cache);
205 
206 		if (!rc && retlen != part->header_size)
207 			rc = -EIO;
208 
209 		if (rc)
210 			goto err;
211 
212 		if (!build_block_map(part, i))
213 			blocks_found++;
214 	}
215 
216 	if (blocks_found == 0) {
217 		printk(KERN_NOTICE PREFIX "no RFD magic found in '%s'\n",
218 				part->mbd.mtd->name);
219 		rc = -ENOENT;
220 		goto err;
221 	}
222 
223 	if (part->reserved_block == -1) {
224 		printk(KERN_WARNING PREFIX "'%s': no empty erase unit found\n",
225 				part->mbd.mtd->name);
226 
227 		part->errors = 1;
228 	}
229 
230 	return 0;
231 
232 err:
233 	vfree(part->sector_map);
234 	kfree(part->header_cache);
235 	kfree(part->blocks);
236 
237 	return rc;
238 }
239 
240 static int rfd_ftl_readsect(struct mtd_blktrans_dev *dev, u_long sector, char *buf)
241 {
242 	struct partition *part = (struct partition*)dev;
243 	u_long addr;
244 	size_t retlen;
245 	int rc;
246 
247 	if (sector >= part->sector_count)
248 		return -EIO;
249 
250 	addr = part->sector_map[sector];
251 	if (addr != -1) {
252 		rc = part->mbd.mtd->read(part->mbd.mtd, addr, SECTOR_SIZE,
253 						&retlen, (u_char*)buf);
254 		if (!rc && retlen != SECTOR_SIZE)
255 			rc = -EIO;
256 
257 		if (rc) {
258 			printk(KERN_WARNING PREFIX "error reading '%s' at "
259 				"0x%lx\n", part->mbd.mtd->name, addr);
260 			return rc;
261 		}
262 	} else
263 		memset(buf, 0, SECTOR_SIZE);
264 
265 	return 0;
266 }
267 
268 static void erase_callback(struct erase_info *erase)
269 {
270 	struct partition *part;
271 	u16 magic;
272 	int i, rc;
273 	size_t retlen;
274 
275 	part = (struct partition*)erase->priv;
276 
277 	i = (u32)erase->addr / part->block_size;
278 	if (i >= part->total_blocks || part->blocks[i].offset != erase->addr ||
279 	    erase->addr > UINT_MAX) {
280 		printk(KERN_ERR PREFIX "erase callback for unknown offset %llx "
281 				"on '%s'\n", (unsigned long long)erase->addr, part->mbd.mtd->name);
282 		return;
283 	}
284 
285 	if (erase->state != MTD_ERASE_DONE) {
286 		printk(KERN_WARNING PREFIX "erase failed at 0x%llx on '%s', "
287 				"state %d\n", (unsigned long long)erase->addr,
288 				part->mbd.mtd->name, erase->state);
289 
290 		part->blocks[i].state = BLOCK_FAILED;
291 		part->blocks[i].free_sectors = 0;
292 		part->blocks[i].used_sectors = 0;
293 
294 		kfree(erase);
295 
296 		return;
297 	}
298 
299 	magic = cpu_to_le16(RFD_MAGIC);
300 
301 	part->blocks[i].state = BLOCK_ERASED;
302 	part->blocks[i].free_sectors = part->data_sectors_per_block;
303 	part->blocks[i].used_sectors = 0;
304 	part->blocks[i].erases++;
305 
306 	rc = part->mbd.mtd->write(part->mbd.mtd,
307 		part->blocks[i].offset, sizeof(magic), &retlen,
308 		(u_char*)&magic);
309 
310 	if (!rc && retlen != sizeof(magic))
311 		rc = -EIO;
312 
313 	if (rc) {
314 		printk(KERN_ERR PREFIX "'%s': unable to write RFD "
315 				"header at 0x%lx\n",
316 				part->mbd.mtd->name,
317 				part->blocks[i].offset);
318 		part->blocks[i].state = BLOCK_FAILED;
319 	}
320 	else
321 		part->blocks[i].state = BLOCK_OK;
322 
323 	kfree(erase);
324 }
325 
326 static int erase_block(struct partition *part, int block)
327 {
328 	struct erase_info *erase;
329 	int rc = -ENOMEM;
330 
331 	erase = kmalloc(sizeof(struct erase_info), GFP_KERNEL);
332 	if (!erase)
333 		goto err;
334 
335 	erase->mtd = part->mbd.mtd;
336 	erase->callback = erase_callback;
337 	erase->addr = part->blocks[block].offset;
338 	erase->len = part->block_size;
339 	erase->priv = (u_long)part;
340 
341 	part->blocks[block].state = BLOCK_ERASING;
342 	part->blocks[block].free_sectors = 0;
343 
344 	rc = part->mbd.mtd->erase(part->mbd.mtd, erase);
345 
346 	if (rc) {
347 		printk(KERN_ERR PREFIX "erase of region %llx,%llx on '%s' "
348 				"failed\n", (unsigned long long)erase->addr,
349 				(unsigned long long)erase->len, part->mbd.mtd->name);
350 		kfree(erase);
351 	}
352 
353 err:
354 	return rc;
355 }
356 
357 static int move_block_contents(struct partition *part, int block_no, u_long *old_sector)
358 {
359 	void *sector_data;
360 	u16 *map;
361 	size_t retlen;
362 	int i, rc = -ENOMEM;
363 
364 	part->is_reclaiming = 1;
365 
366 	sector_data = kmalloc(SECTOR_SIZE, GFP_KERNEL);
367 	if (!sector_data)
368 		goto err3;
369 
370 	map = kmalloc(part->header_size, GFP_KERNEL);
371 	if (!map)
372 		goto err2;
373 
374 	rc = part->mbd.mtd->read(part->mbd.mtd,
375 		part->blocks[block_no].offset, part->header_size,
376 		&retlen, (u_char*)map);
377 
378 	if (!rc && retlen != part->header_size)
379 		rc = -EIO;
380 
381 	if (rc) {
382 		printk(KERN_ERR PREFIX "error reading '%s' at "
383 			"0x%lx\n", part->mbd.mtd->name,
384 			part->blocks[block_no].offset);
385 
386 		goto err;
387 	}
388 
389 	for (i=0; i<part->data_sectors_per_block; i++) {
390 		u16 entry = le16_to_cpu(map[HEADER_MAP_OFFSET + i]);
391 		u_long addr;
392 
393 
394 		if (entry == SECTOR_FREE || entry == SECTOR_DELETED)
395 			continue;
396 
397 		if (entry == SECTOR_ZERO)
398 			entry = 0;
399 
400 		/* already warned about and ignored in build_block_map() */
401 		if (entry >= part->sector_count)
402 			continue;
403 
404 		addr = part->blocks[block_no].offset +
405 			(i + part->header_sectors_per_block) * SECTOR_SIZE;
406 
407 		if (*old_sector == addr) {
408 			*old_sector = -1;
409 			if (!part->blocks[block_no].used_sectors--) {
410 				rc = erase_block(part, block_no);
411 				break;
412 			}
413 			continue;
414 		}
415 		rc = part->mbd.mtd->read(part->mbd.mtd, addr,
416 			SECTOR_SIZE, &retlen, sector_data);
417 
418 		if (!rc && retlen != SECTOR_SIZE)
419 			rc = -EIO;
420 
421 		if (rc) {
422 			printk(KERN_ERR PREFIX "'%s': Unable to "
423 				"read sector for relocation\n",
424 				part->mbd.mtd->name);
425 
426 			goto err;
427 		}
428 
429 		rc = rfd_ftl_writesect((struct mtd_blktrans_dev*)part,
430 				entry, sector_data);
431 
432 		if (rc)
433 			goto err;
434 	}
435 
436 err:
437 	kfree(map);
438 err2:
439 	kfree(sector_data);
440 err3:
441 	part->is_reclaiming = 0;
442 
443 	return rc;
444 }
445 
446 static int reclaim_block(struct partition *part, u_long *old_sector)
447 {
448 	int block, best_block, score, old_sector_block;
449 	int rc;
450 
451 	/* we have a race if sync doesn't exist */
452 	if (part->mbd.mtd->sync)
453 		part->mbd.mtd->sync(part->mbd.mtd);
454 
455 	score = 0x7fffffff; /* MAX_INT */
456 	best_block = -1;
457 	if (*old_sector != -1)
458 		old_sector_block = *old_sector / part->block_size;
459 	else
460 		old_sector_block = -1;
461 
462 	for (block=0; block<part->total_blocks; block++) {
463 		int this_score;
464 
465 		if (block == part->reserved_block)
466 			continue;
467 
468 		/*
469 		 * Postpone reclaiming if there is a free sector as
470 		 * more removed sectors is more efficient (have to move
471 		 * less).
472 		 */
473 		if (part->blocks[block].free_sectors)
474 			return 0;
475 
476 		this_score = part->blocks[block].used_sectors;
477 
478 		if (block == old_sector_block)
479 			this_score--;
480 		else {
481 			/* no point in moving a full block */
482 			if (part->blocks[block].used_sectors ==
483 					part->data_sectors_per_block)
484 				continue;
485 		}
486 
487 		this_score += part->blocks[block].erases;
488 
489 		if (this_score < score) {
490 			best_block = block;
491 			score = this_score;
492 		}
493 	}
494 
495 	if (best_block == -1)
496 		return -ENOSPC;
497 
498 	part->current_block = -1;
499 	part->reserved_block = best_block;
500 
501 	pr_debug("reclaim_block: reclaiming block #%d with %d used "
502 		 "%d free sectors\n", best_block,
503 		 part->blocks[best_block].used_sectors,
504 		 part->blocks[best_block].free_sectors);
505 
506 	if (part->blocks[best_block].used_sectors)
507 		rc = move_block_contents(part, best_block, old_sector);
508 	else
509 		rc = erase_block(part, best_block);
510 
511 	return rc;
512 }
513 
514 /*
515  * IMPROVE: It would be best to choose the block with the most deleted sectors,
516  * because if we fill that one up first it'll have the most chance of having
517  * the least live sectors at reclaim.
518  */
519 static int find_free_block(struct partition *part)
520 {
521 	int block, stop;
522 
523 	block = part->current_block == -1 ?
524 			jiffies % part->total_blocks : part->current_block;
525 	stop = block;
526 
527 	do {
528 		if (part->blocks[block].free_sectors &&
529 				block != part->reserved_block)
530 			return block;
531 
532 		if (part->blocks[block].state == BLOCK_UNUSED)
533 			erase_block(part, 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_writable_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_ERR 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 = 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_ERR 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_writable_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_ERR 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_ERR 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 || mtd->size > UINT_MAX)
766 		return;
767 
768 	part = kzalloc(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_WARNING PREFIX "please provide block_size");
779 			goto out;
780 		} else
781 			part->block_size = mtd->erasesize;
782 	}
783 
784 	if (scan_header(part) == 0) {
785 		part->mbd.size = part->sector_count;
786 		part->mbd.tr = tr;
787 		part->mbd.devnum = -1;
788 		if (!(mtd->flags & MTD_WRITEABLE))
789 			part->mbd.readonly = 1;
790 		else if (part->errors) {
791 			printk(KERN_WARNING PREFIX "'%s': errors found, "
792 					"setting read-only\n", mtd->name);
793 			part->mbd.readonly = 1;
794 		}
795 
796 		printk(KERN_INFO PREFIX "name: '%s' type: %d flags %x\n",
797 				mtd->name, mtd->type, mtd->flags);
798 
799 		if (!add_mtd_blktrans_dev((void*)part))
800 			return;
801 	}
802 out:
803 	kfree(part);
804 }
805 
806 static void rfd_ftl_remove_dev(struct mtd_blktrans_dev *dev)
807 {
808 	struct partition *part = (struct partition*)dev;
809 	int i;
810 
811 	for (i=0; i<part->total_blocks; i++) {
812 		pr_debug("rfd_ftl_remove_dev:'%s': erase unit #%02d: %d erases\n",
813 			part->mbd.mtd->name, i, part->blocks[i].erases);
814 	}
815 
816 	del_mtd_blktrans_dev(dev);
817 	vfree(part->sector_map);
818 	kfree(part->header_cache);
819 	kfree(part->blocks);
820 }
821 
822 static struct mtd_blktrans_ops rfd_ftl_tr = {
823 	.name		= "rfd",
824 	.major		= RFD_FTL_MAJOR,
825 	.part_bits	= PART_BITS,
826 	.blksize 	= SECTOR_SIZE,
827 
828 	.readsect	= rfd_ftl_readsect,
829 	.writesect	= rfd_ftl_writesect,
830 	.getgeo		= rfd_ftl_getgeo,
831 	.add_mtd	= rfd_ftl_add_mtd,
832 	.remove_dev	= rfd_ftl_remove_dev,
833 	.owner		= THIS_MODULE,
834 };
835 
836 static int __init init_rfd_ftl(void)
837 {
838 	return register_mtd_blktrans(&rfd_ftl_tr);
839 }
840 
841 static void __exit cleanup_rfd_ftl(void)
842 {
843 	deregister_mtd_blktrans(&rfd_ftl_tr);
844 }
845 
846 module_init(init_rfd_ftl);
847 module_exit(cleanup_rfd_ftl);
848 
849 MODULE_LICENSE("GPL");
850 MODULE_AUTHOR("Sean Young <sean@mess.org>");
851 MODULE_DESCRIPTION("Support code for RFD Flash Translation Layer, "
852 		"used by General Software's Embedded BIOS");
853 
854