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15#include <linux/hdreg.h>
16#include <linux/init.h>
17#include <linux/mtd/blktrans.h>
18#include <linux/mtd/mtd.h>
19#include <linux/vmalloc.h>
20#include <linux/slab.h>
21#include <linux/jiffies.h>
22#include <linux/module.h>
23
24#include <asm/types.h>
25
26static int block_size = 0;
27module_param(block_size, int, 0);
28MODULE_PARM_DESC(block_size, "Block size to use by RFD, defaults to erase unit size");
29
30#define PREFIX "rfd_ftl: "
31
32
33#ifndef RFD_FTL_MAJOR
34#define RFD_FTL_MAJOR 256
35#endif
36
37
38#define PART_BITS 4
39
40
41#define RFD_MAGIC 0x9193
42
43
44
45
46
47
48#define HEADER_MAP_OFFSET 3
49#define SECTOR_DELETED 0x0000
50#define SECTOR_ZERO 0xfffe
51#define SECTOR_FREE 0xffff
52
53#define SECTOR_SIZE 512
54
55#define SECTORS_PER_TRACK 63
56
57struct block {
58 enum {
59 BLOCK_OK,
60 BLOCK_ERASING,
61 BLOCK_ERASED,
62 BLOCK_UNUSED,
63 BLOCK_FAILED
64 } state;
65 int free_sectors;
66 int used_sectors;
67 int erases;
68 u_long offset;
69};
70
71struct partition {
72 struct mtd_blktrans_dev mbd;
73
74 u_int block_size;
75 u_int total_blocks;
76 u_int header_sectors_per_block;
77 u_int data_sectors_per_block;
78 u_int sector_count;
79 u_int header_size;
80 int reserved_block;
81 int current_block;
82 u16 *header_cache;
83
84 int is_reclaiming;
85 int cylinders;
86 int errors;
87 u_long *sector_map;
88 struct block *blocks;
89};
90
91static int rfd_ftl_writesect(struct mtd_blktrans_dev *dev, u_long sector, char *buf);
92
93static 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_UNUSED;
102 return -ENOENT;
103 }
104
105 block->state = BLOCK_OK;
106
107 for (i=0; i<part->data_sectors_per_block; i++) {
108 u16 entry;
109
110 entry = le16_to_cpu(part->header_cache[HEADER_MAP_OFFSET + i]);
111
112 if (entry == SECTOR_DELETED)
113 continue;
114
115 if (entry == SECTOR_FREE) {
116 block->free_sectors++;
117 continue;
118 }
119
120 if (entry == SECTOR_ZERO)
121 entry = 0;
122
123 if (entry >= part->sector_count) {
124 printk(KERN_WARNING PREFIX
125 "'%s': unit #%d: entry %d corrupt, "
126 "sector %d out of range\n",
127 part->mbd.mtd->name, block_no, i, entry);
128 continue;
129 }
130
131 if (part->sector_map[entry] != -1) {
132 printk(KERN_WARNING PREFIX
133 "'%s': more than one entry for sector %d\n",
134 part->mbd.mtd->name, entry);
135 part->errors = 1;
136 continue;
137 }
138
139 part->sector_map[entry] = block->offset +
140 (i + part->header_sectors_per_block) * SECTOR_SIZE;
141
142 block->used_sectors++;
143 }
144
145 if (block->free_sectors == part->data_sectors_per_block)
146 part->reserved_block = block_no;
147
148 return 0;
149}
150
151static int scan_header(struct partition *part)
152{
153 int sectors_per_block;
154 int i, rc = -ENOMEM;
155 int blocks_found;
156 size_t retlen;
157
158 sectors_per_block = part->block_size / SECTOR_SIZE;
159 part->total_blocks = (u32)part->mbd.mtd->size / part->block_size;
160
161 if (part->total_blocks < 2)
162 return -ENOENT;
163
164
165 part->header_sectors_per_block =
166 ((HEADER_MAP_OFFSET + sectors_per_block) *
167 sizeof(u16) + SECTOR_SIZE - 1) / SECTOR_SIZE;
168
169 part->data_sectors_per_block = sectors_per_block -
170 part->header_sectors_per_block;
171
172 part->header_size = (HEADER_MAP_OFFSET +
173 part->data_sectors_per_block) * sizeof(u16);
174
175 part->cylinders = (part->data_sectors_per_block *
176 (part->total_blocks - 1) - 1) / SECTORS_PER_TRACK;
177
178 part->sector_count = part->cylinders * SECTORS_PER_TRACK;
179
180 part->current_block = -1;
181 part->reserved_block = -1;
182 part->is_reclaiming = 0;
183
184 part->header_cache = kmalloc(part->header_size, GFP_KERNEL);
185 if (!part->header_cache)
186 goto err;
187
188 part->blocks = kcalloc(part->total_blocks, sizeof(struct block),
189 GFP_KERNEL);
190 if (!part->blocks)
191 goto err;
192
193 part->sector_map = vmalloc(array_size(sizeof(u_long),
194 part->sector_count));
195 if (!part->sector_map)
196 goto err;
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 = mtd_read(part->mbd.mtd, i * part->block_size,
203 part->header_size, &retlen,
204 (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
232err:
233 vfree(part->sector_map);
234 kfree(part->header_cache);
235 kfree(part->blocks);
236
237 return rc;
238}
239
240static int rfd_ftl_readsect(struct mtd_blktrans_dev *dev, u_long sector, char *buf)
241{
242 struct partition *part = container_of(dev, struct partition, mbd);
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 = mtd_read(part->mbd.mtd, addr, SECTOR_SIZE, &retlen,
253 (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
268static int erase_block(struct partition *part, int block)
269{
270 struct erase_info *erase;
271 int rc;
272
273 erase = kmalloc(sizeof(struct erase_info), GFP_KERNEL);
274 if (!erase)
275 return -ENOMEM;
276
277 erase->addr = part->blocks[block].offset;
278 erase->len = part->block_size;
279
280 part->blocks[block].state = BLOCK_ERASING;
281 part->blocks[block].free_sectors = 0;
282
283 rc = mtd_erase(part->mbd.mtd, erase);
284 if (rc) {
285 printk(KERN_ERR PREFIX "erase of region %llx,%llx on '%s' "
286 "failed\n", (unsigned long long)erase->addr,
287 (unsigned long long)erase->len, part->mbd.mtd->name);
288 part->blocks[block].state = BLOCK_FAILED;
289 part->blocks[block].free_sectors = 0;
290 part->blocks[block].used_sectors = 0;
291 } else {
292 u16 magic = cpu_to_le16(RFD_MAGIC);
293 size_t retlen;
294
295 part->blocks[block].state = BLOCK_ERASED;
296 part->blocks[block].free_sectors = part->data_sectors_per_block;
297 part->blocks[block].used_sectors = 0;
298 part->blocks[block].erases++;
299
300 rc = mtd_write(part->mbd.mtd, part->blocks[block].offset,
301 sizeof(magic), &retlen, (u_char *)&magic);
302 if (!rc && retlen != sizeof(magic))
303 rc = -EIO;
304
305 if (rc) {
306 pr_err(PREFIX "'%s': unable to write RFD header at 0x%lx\n",
307 part->mbd.mtd->name, part->blocks[block].offset);
308 part->blocks[block].state = BLOCK_FAILED;
309 } else {
310 part->blocks[block].state = BLOCK_OK;
311 }
312 }
313
314 kfree(erase);
315
316 return rc;
317}
318
319static int move_block_contents(struct partition *part, int block_no, u_long *old_sector)
320{
321 void *sector_data;
322 u16 *map;
323 size_t retlen;
324 int i, rc = -ENOMEM;
325
326 part->is_reclaiming = 1;
327
328 sector_data = kmalloc(SECTOR_SIZE, GFP_KERNEL);
329 if (!sector_data)
330 goto err3;
331
332 map = kmalloc(part->header_size, GFP_KERNEL);
333 if (!map)
334 goto err2;
335
336 rc = mtd_read(part->mbd.mtd, part->blocks[block_no].offset,
337 part->header_size, &retlen, (u_char *)map);
338
339 if (!rc && retlen != part->header_size)
340 rc = -EIO;
341
342 if (rc) {
343 printk(KERN_ERR PREFIX "error reading '%s' at "
344 "0x%lx\n", part->mbd.mtd->name,
345 part->blocks[block_no].offset);
346
347 goto err;
348 }
349
350 for (i=0; i<part->data_sectors_per_block; i++) {
351 u16 entry = le16_to_cpu(map[HEADER_MAP_OFFSET + i]);
352 u_long addr;
353
354
355 if (entry == SECTOR_FREE || entry == SECTOR_DELETED)
356 continue;
357
358 if (entry == SECTOR_ZERO)
359 entry = 0;
360
361
362 if (entry >= part->sector_count)
363 continue;
364
365 addr = part->blocks[block_no].offset +
366 (i + part->header_sectors_per_block) * SECTOR_SIZE;
367
368 if (*old_sector == addr) {
369 *old_sector = -1;
370 if (!part->blocks[block_no].used_sectors--) {
371 rc = erase_block(part, block_no);
372 break;
373 }
374 continue;
375 }
376 rc = mtd_read(part->mbd.mtd, addr, SECTOR_SIZE, &retlen,
377 sector_data);
378
379 if (!rc && retlen != SECTOR_SIZE)
380 rc = -EIO;
381
382 if (rc) {
383 printk(KERN_ERR PREFIX "'%s': Unable to "
384 "read sector for relocation\n",
385 part->mbd.mtd->name);
386
387 goto err;
388 }
389
390 rc = rfd_ftl_writesect((struct mtd_blktrans_dev*)part,
391 entry, sector_data);
392
393 if (rc)
394 goto err;
395 }
396
397err:
398 kfree(map);
399err2:
400 kfree(sector_data);
401err3:
402 part->is_reclaiming = 0;
403
404 return rc;
405}
406
407static int reclaim_block(struct partition *part, u_long *old_sector)
408{
409 int block, best_block, score, old_sector_block;
410 int rc;
411
412
413 mtd_sync(part->mbd.mtd);
414
415 score = 0x7fffffff;
416 best_block = -1;
417 if (*old_sector != -1)
418 old_sector_block = *old_sector / part->block_size;
419 else
420 old_sector_block = -1;
421
422 for (block=0; block<part->total_blocks; block++) {
423 int this_score;
424
425 if (block == part->reserved_block)
426 continue;
427
428
429
430
431
432
433 if (part->blocks[block].free_sectors)
434 return 0;
435
436 this_score = part->blocks[block].used_sectors;
437
438 if (block == old_sector_block)
439 this_score--;
440 else {
441
442 if (part->blocks[block].used_sectors ==
443 part->data_sectors_per_block)
444 continue;
445 }
446
447 this_score += part->blocks[block].erases;
448
449 if (this_score < score) {
450 best_block = block;
451 score = this_score;
452 }
453 }
454
455 if (best_block == -1)
456 return -ENOSPC;
457
458 part->current_block = -1;
459 part->reserved_block = best_block;
460
461 pr_debug("reclaim_block: reclaiming block #%d with %d used "
462 "%d free sectors\n", best_block,
463 part->blocks[best_block].used_sectors,
464 part->blocks[best_block].free_sectors);
465
466 if (part->blocks[best_block].used_sectors)
467 rc = move_block_contents(part, best_block, old_sector);
468 else
469 rc = erase_block(part, best_block);
470
471 return rc;
472}
473
474
475
476
477
478
479static int find_free_block(struct partition *part)
480{
481 int block, stop;
482
483 block = part->current_block == -1 ?
484 jiffies % part->total_blocks : part->current_block;
485 stop = block;
486
487 do {
488 if (part->blocks[block].free_sectors &&
489 block != part->reserved_block)
490 return block;
491
492 if (part->blocks[block].state == BLOCK_UNUSED)
493 erase_block(part, block);
494
495 if (++block >= part->total_blocks)
496 block = 0;
497
498 } while (block != stop);
499
500 return -1;
501}
502
503static int find_writable_block(struct partition *part, u_long *old_sector)
504{
505 int rc, block;
506 size_t retlen;
507
508 block = find_free_block(part);
509
510 if (block == -1) {
511 if (!part->is_reclaiming) {
512 rc = reclaim_block(part, old_sector);
513 if (rc)
514 goto err;
515
516 block = find_free_block(part);
517 }
518
519 if (block == -1) {
520 rc = -ENOSPC;
521 goto err;
522 }
523 }
524
525 rc = mtd_read(part->mbd.mtd, part->blocks[block].offset,
526 part->header_size, &retlen,
527 (u_char *)part->header_cache);
528
529 if (!rc && retlen != part->header_size)
530 rc = -EIO;
531
532 if (rc) {
533 printk(KERN_ERR PREFIX "'%s': unable to read header at "
534 "0x%lx\n", part->mbd.mtd->name,
535 part->blocks[block].offset);
536 goto err;
537 }
538
539 part->current_block = block;
540
541err:
542 return rc;
543}
544
545static int mark_sector_deleted(struct partition *part, u_long old_addr)
546{
547 int block, offset, rc;
548 u_long addr;
549 size_t retlen;
550 u16 del = cpu_to_le16(SECTOR_DELETED);
551
552 block = old_addr / part->block_size;
553 offset = (old_addr % part->block_size) / SECTOR_SIZE -
554 part->header_sectors_per_block;
555
556 addr = part->blocks[block].offset +
557 (HEADER_MAP_OFFSET + offset) * sizeof(u16);
558 rc = mtd_write(part->mbd.mtd, addr, sizeof(del), &retlen,
559 (u_char *)&del);
560
561 if (!rc && retlen != sizeof(del))
562 rc = -EIO;
563
564 if (rc) {
565 printk(KERN_ERR PREFIX "error writing '%s' at "
566 "0x%lx\n", part->mbd.mtd->name, addr);
567 goto err;
568 }
569 if (block == part->current_block)
570 part->header_cache[offset + HEADER_MAP_OFFSET] = del;
571
572 part->blocks[block].used_sectors--;
573
574 if (!part->blocks[block].used_sectors &&
575 !part->blocks[block].free_sectors)
576 rc = erase_block(part, block);
577
578err:
579 return rc;
580}
581
582static int find_free_sector(const struct partition *part, const struct block *block)
583{
584 int i, stop;
585
586 i = stop = part->data_sectors_per_block - block->free_sectors;
587
588 do {
589 if (le16_to_cpu(part->header_cache[HEADER_MAP_OFFSET + i])
590 == SECTOR_FREE)
591 return i;
592
593 if (++i == part->data_sectors_per_block)
594 i = 0;
595 }
596 while(i != stop);
597
598 return -1;
599}
600
601static int do_writesect(struct mtd_blktrans_dev *dev, u_long sector, char *buf, ulong *old_addr)
602{
603 struct partition *part = container_of(dev, struct partition, mbd);
604 struct block *block;
605 u_long addr;
606 int i;
607 int rc;
608 size_t retlen;
609 u16 entry;
610
611 if (part->current_block == -1 ||
612 !part->blocks[part->current_block].free_sectors) {
613
614 rc = find_writable_block(part, old_addr);
615 if (rc)
616 goto err;
617 }
618
619 block = &part->blocks[part->current_block];
620
621 i = find_free_sector(part, block);
622
623 if (i < 0) {
624 rc = -ENOSPC;
625 goto err;
626 }
627
628 addr = (i + part->header_sectors_per_block) * SECTOR_SIZE +
629 block->offset;
630 rc = mtd_write(part->mbd.mtd, addr, SECTOR_SIZE, &retlen,
631 (u_char *)buf);
632
633 if (!rc && retlen != SECTOR_SIZE)
634 rc = -EIO;
635
636 if (rc) {
637 printk(KERN_ERR PREFIX "error writing '%s' at 0x%lx\n",
638 part->mbd.mtd->name, addr);
639 goto err;
640 }
641
642 part->sector_map[sector] = addr;
643
644 entry = cpu_to_le16(sector == 0 ? SECTOR_ZERO : sector);
645
646 part->header_cache[i + HEADER_MAP_OFFSET] = entry;
647
648 addr = block->offset + (HEADER_MAP_OFFSET + i) * sizeof(u16);
649 rc = mtd_write(part->mbd.mtd, addr, sizeof(entry), &retlen,
650 (u_char *)&entry);
651
652 if (!rc && retlen != sizeof(entry))
653 rc = -EIO;
654
655 if (rc) {
656 printk(KERN_ERR PREFIX "error writing '%s' at 0x%lx\n",
657 part->mbd.mtd->name, addr);
658 goto err;
659 }
660 block->used_sectors++;
661 block->free_sectors--;
662
663err:
664 return rc;
665}
666
667static int rfd_ftl_writesect(struct mtd_blktrans_dev *dev, u_long sector, char *buf)
668{
669 struct partition *part = container_of(dev, struct partition, mbd);
670 u_long old_addr;
671 int i;
672 int rc = 0;
673
674 pr_debug("rfd_ftl_writesect(sector=0x%lx)\n", sector);
675
676 if (part->reserved_block == -1) {
677 rc = -EACCES;
678 goto err;
679 }
680
681 if (sector >= part->sector_count) {
682 rc = -EIO;
683 goto err;
684 }
685
686 old_addr = part->sector_map[sector];
687
688 for (i=0; i<SECTOR_SIZE; i++) {
689 if (!buf[i])
690 continue;
691
692 rc = do_writesect(dev, sector, buf, &old_addr);
693 if (rc)
694 goto err;
695 break;
696 }
697
698 if (i == SECTOR_SIZE)
699 part->sector_map[sector] = -1;
700
701 if (old_addr != -1)
702 rc = mark_sector_deleted(part, old_addr);
703
704err:
705 return rc;
706}
707
708static int rfd_ftl_discardsect(struct mtd_blktrans_dev *dev,
709 unsigned long sector, unsigned int nr_sects)
710{
711 struct partition *part = container_of(dev, struct partition, mbd);
712 u_long addr;
713 int rc;
714
715 while (nr_sects) {
716 if (sector >= part->sector_count)
717 return -EIO;
718
719 addr = part->sector_map[sector];
720
721 if (addr != -1) {
722 rc = mark_sector_deleted(part, addr);
723 if (rc)
724 return rc;
725
726 part->sector_map[sector] = -1;
727 }
728
729 sector++;
730 nr_sects--;
731 }
732
733 return 0;
734}
735
736static int rfd_ftl_getgeo(struct mtd_blktrans_dev *dev, struct hd_geometry *geo)
737{
738 struct partition *part = container_of(dev, struct partition, mbd);
739
740 geo->heads = 1;
741 geo->sectors = SECTORS_PER_TRACK;
742 geo->cylinders = part->cylinders;
743
744 return 0;
745}
746
747static void rfd_ftl_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
748{
749 struct partition *part;
750
751 if ((mtd->type != MTD_NORFLASH && mtd->type != MTD_RAM) ||
752 mtd->size > UINT_MAX)
753 return;
754
755 part = kzalloc(sizeof(struct partition), GFP_KERNEL);
756 if (!part)
757 return;
758
759 part->mbd.mtd = mtd;
760
761 if (block_size)
762 part->block_size = block_size;
763 else {
764 if (!mtd->erasesize) {
765 printk(KERN_WARNING PREFIX "please provide block_size");
766 goto out;
767 } else
768 part->block_size = mtd->erasesize;
769 }
770
771 if (scan_header(part) == 0) {
772 part->mbd.size = part->sector_count;
773 part->mbd.tr = tr;
774 part->mbd.devnum = -1;
775 if (!(mtd->flags & MTD_WRITEABLE))
776 part->mbd.readonly = 1;
777 else if (part->errors) {
778 printk(KERN_WARNING PREFIX "'%s': errors found, "
779 "setting read-only\n", mtd->name);
780 part->mbd.readonly = 1;
781 }
782
783 printk(KERN_INFO PREFIX "name: '%s' type: %d flags %x\n",
784 mtd->name, mtd->type, mtd->flags);
785
786 if (!add_mtd_blktrans_dev(&part->mbd))
787 return;
788 }
789out:
790 kfree(part);
791}
792
793static void rfd_ftl_remove_dev(struct mtd_blktrans_dev *dev)
794{
795 struct partition *part = container_of(dev, struct partition, mbd);
796 int i;
797
798 for (i=0; i<part->total_blocks; i++) {
799 pr_debug("rfd_ftl_remove_dev:'%s': erase unit #%02d: %d erases\n",
800 part->mbd.mtd->name, i, part->blocks[i].erases);
801 }
802
803 vfree(part->sector_map);
804 kfree(part->header_cache);
805 kfree(part->blocks);
806 del_mtd_blktrans_dev(&part->mbd);
807}
808
809static struct mtd_blktrans_ops rfd_ftl_tr = {
810 .name = "rfd",
811 .major = RFD_FTL_MAJOR,
812 .part_bits = PART_BITS,
813 .blksize = SECTOR_SIZE,
814
815 .readsect = rfd_ftl_readsect,
816 .writesect = rfd_ftl_writesect,
817 .discard = rfd_ftl_discardsect,
818 .getgeo = rfd_ftl_getgeo,
819 .add_mtd = rfd_ftl_add_mtd,
820 .remove_dev = rfd_ftl_remove_dev,
821 .owner = THIS_MODULE,
822};
823
824module_mtd_blktrans(rfd_ftl_tr);
825
826MODULE_LICENSE("GPL");
827MODULE_AUTHOR("Sean Young <sean@mess.org>");
828MODULE_DESCRIPTION("Support code for RFD Flash Translation Layer, "
829 "used by General Software's Embedded BIOS");
830
831
