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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
25static int block_size = 0;
26module_param(block_size, int, 0);
27MODULE_PARM_DESC(block_size, "Block size to use by RFD, defaults to erase unit size");
28
29#define PREFIX "rfd_ftl: "
30
31
32#ifndef RFD_FTL_MAJOR
33#define RFD_FTL_MAJOR 256
34#endif
35
36
37#define PART_BITS 4
38
39
40#define RFD_MAGIC 0x9193
41
42
43
44
45
46
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
56struct 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
70struct partition {
71 struct mtd_blktrans_dev mbd;
72
73 u_int block_size;
74 u_int total_blocks;
75 u_int header_sectors_per_block;
76 u_int data_sectors_per_block;
77 u_int sector_count;
78 u_int header_size;
79 int reserved_block;
80 int current_block;
81 u16 *header_cache;
82
83 int is_reclaiming;
84 int cylinders;
85 int errors;
86 u_long *sector_map;
87 struct block *blocks;
88};
89
90static int rfd_ftl_writesect(struct mtd_blktrans_dev *dev, u_long sector, char *buf);
91
92static 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
150static 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
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 = mtd_read(part->mbd.mtd, i * part->block_size,
204 part->header_size, &retlen,
205 (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
233err:
234 vfree(part->sector_map);
235 kfree(part->header_cache);
236 kfree(part->blocks);
237
238 return rc;
239}
240
241static 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 = mtd_read(part->mbd.mtd, addr, SECTOR_SIZE, &retlen,
254 (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
269static int erase_block(struct partition *part, int block)
270{
271 struct erase_info *erase;
272 int rc;
273
274 erase = kmalloc(sizeof(struct erase_info), GFP_KERNEL);
275 if (!erase)
276 return -ENOMEM;
277
278 erase->addr = part->blocks[block].offset;
279 erase->len = part->block_size;
280
281 part->blocks[block].state = BLOCK_ERASING;
282 part->blocks[block].free_sectors = 0;
283
284 rc = mtd_erase(part->mbd.mtd, erase);
285 if (rc) {
286 printk(KERN_ERR PREFIX "erase of region %llx,%llx on '%s' "
287 "failed\n", (unsigned long long)erase->addr,
288 (unsigned long long)erase->len, part->mbd.mtd->name);
289 part->blocks[block].state = BLOCK_FAILED;
290 part->blocks[block].free_sectors = 0;
291 part->blocks[block].used_sectors = 0;
292 } else {
293 u16 magic = cpu_to_le16(RFD_MAGIC);
294 size_t retlen;
295
296 part->blocks[block].state = BLOCK_ERASED;
297 part->blocks[block].free_sectors = part->data_sectors_per_block;
298 part->blocks[block].used_sectors = 0;
299 part->blocks[block].erases++;
300
301 rc = mtd_write(part->mbd.mtd, part->blocks[block].offset,
302 sizeof(magic), &retlen, (u_char *)&magic);
303 if (!rc && retlen != sizeof(magic))
304 rc = -EIO;
305
306 if (rc) {
307 pr_err(PREFIX "'%s': unable to write RFD header at 0x%lx\n",
308 part->mbd.mtd->name, part->blocks[block].offset);
309 part->blocks[block].state = BLOCK_FAILED;
310 } else {
311 part->blocks[block].state = BLOCK_OK;
312 }
313 }
314
315 kfree(erase);
316
317 return rc;
318}
319
320static int move_block_contents(struct partition *part, int block_no, u_long *old_sector)
321{
322 void *sector_data;
323 u16 *map;
324 size_t retlen;
325 int i, rc = -ENOMEM;
326
327 part->is_reclaiming = 1;
328
329 sector_data = kmalloc(SECTOR_SIZE, GFP_KERNEL);
330 if (!sector_data)
331 goto err3;
332
333 map = kmalloc(part->header_size, GFP_KERNEL);
334 if (!map)
335 goto err2;
336
337 rc = mtd_read(part->mbd.mtd, part->blocks[block_no].offset,
338 part->header_size, &retlen, (u_char *)map);
339
340 if (!rc && retlen != part->header_size)
341 rc = -EIO;
342
343 if (rc) {
344 printk(KERN_ERR PREFIX "error reading '%s' at "
345 "0x%lx\n", part->mbd.mtd->name,
346 part->blocks[block_no].offset);
347
348 goto err;
349 }
350
351 for (i=0; i<part->data_sectors_per_block; i++) {
352 u16 entry = le16_to_cpu(map[HEADER_MAP_OFFSET + i]);
353 u_long addr;
354
355
356 if (entry == SECTOR_FREE || entry == SECTOR_DELETED)
357 continue;
358
359 if (entry == SECTOR_ZERO)
360 entry = 0;
361
362
363 if (entry >= part->sector_count)
364 continue;
365
366 addr = part->blocks[block_no].offset +
367 (i + part->header_sectors_per_block) * SECTOR_SIZE;
368
369 if (*old_sector == addr) {
370 *old_sector = -1;
371 if (!part->blocks[block_no].used_sectors--) {
372 rc = erase_block(part, block_no);
373 break;
374 }
375 continue;
376 }
377 rc = mtd_read(part->mbd.mtd, addr, SECTOR_SIZE, &retlen,
378 sector_data);
379
380 if (!rc && retlen != SECTOR_SIZE)
381 rc = -EIO;
382
383 if (rc) {
384 printk(KERN_ERR PREFIX "'%s': Unable to "
385 "read sector for relocation\n",
386 part->mbd.mtd->name);
387
388 goto err;
389 }
390
391 rc = rfd_ftl_writesect((struct mtd_blktrans_dev*)part,
392 entry, sector_data);
393
394 if (rc)
395 goto err;
396 }
397
398err:
399 kfree(map);
400err2:
401 kfree(sector_data);
402err3:
403 part->is_reclaiming = 0;
404
405 return rc;
406}
407
408static int reclaim_block(struct partition *part, u_long *old_sector)
409{
410 int block, best_block, score, old_sector_block;
411 int rc;
412
413
414 mtd_sync(part->mbd.mtd);
415
416 score = 0x7fffffff;
417 best_block = -1;
418 if (*old_sector != -1)
419 old_sector_block = *old_sector / part->block_size;
420 else
421 old_sector_block = -1;
422
423 for (block=0; block<part->total_blocks; block++) {
424 int this_score;
425
426 if (block == part->reserved_block)
427 continue;
428
429
430
431
432
433
434 if (part->blocks[block].free_sectors)
435 return 0;
436
437 this_score = part->blocks[block].used_sectors;
438
439 if (block == old_sector_block)
440 this_score--;
441 else {
442
443 if (part->blocks[block].used_sectors ==
444 part->data_sectors_per_block)
445 continue;
446 }
447
448 this_score += part->blocks[block].erases;
449
450 if (this_score < score) {
451 best_block = block;
452 score = this_score;
453 }
454 }
455
456 if (best_block == -1)
457 return -ENOSPC;
458
459 part->current_block = -1;
460 part->reserved_block = best_block;
461
462 pr_debug("reclaim_block: reclaiming block #%d with %d used "
463 "%d free sectors\n", best_block,
464 part->blocks[best_block].used_sectors,
465 part->blocks[best_block].free_sectors);
466
467 if (part->blocks[best_block].used_sectors)
468 rc = move_block_contents(part, best_block, old_sector);
469 else
470 rc = erase_block(part, best_block);
471
472 return rc;
473}
474
475
476
477
478
479
480static int find_free_block(struct partition *part)
481{
482 int block, stop;
483
484 block = part->current_block == -1 ?
485 jiffies % part->total_blocks : part->current_block;
486 stop = block;
487
488 do {
489 if (part->blocks[block].free_sectors &&
490 block != part->reserved_block)
491 return block;
492
493 if (part->blocks[block].state == BLOCK_UNUSED)
494 erase_block(part, block);
495
496 if (++block >= part->total_blocks)
497 block = 0;
498
499 } while (block != stop);
500
501 return -1;
502}
503
504static int find_writable_block(struct partition *part, u_long *old_sector)
505{
506 int rc, block;
507 size_t retlen;
508
509 block = find_free_block(part);
510
511 if (block == -1) {
512 if (!part->is_reclaiming) {
513 rc = reclaim_block(part, old_sector);
514 if (rc)
515 goto err;
516
517 block = find_free_block(part);
518 }
519
520 if (block == -1) {
521 rc = -ENOSPC;
522 goto err;
523 }
524 }
525
526 rc = mtd_read(part->mbd.mtd, part->blocks[block].offset,
527 part->header_size, &retlen,
528 (u_char *)part->header_cache);
529
530 if (!rc && retlen != part->header_size)
531 rc = -EIO;
532
533 if (rc) {
534 printk(KERN_ERR PREFIX "'%s': unable to read header at "
535 "0x%lx\n", part->mbd.mtd->name,
536 part->blocks[block].offset);
537 goto err;
538 }
539
540 part->current_block = block;
541
542err:
543 return rc;
544}
545
546static int mark_sector_deleted(struct partition *part, u_long old_addr)
547{
548 int block, offset, rc;
549 u_long addr;
550 size_t retlen;
551 u16 del = cpu_to_le16(SECTOR_DELETED);
552
553 block = old_addr / part->block_size;
554 offset = (old_addr % part->block_size) / SECTOR_SIZE -
555 part->header_sectors_per_block;
556
557 addr = part->blocks[block].offset +
558 (HEADER_MAP_OFFSET + offset) * sizeof(u16);
559 rc = mtd_write(part->mbd.mtd, addr, sizeof(del), &retlen,
560 (u_char *)&del);
561
562 if (!rc && retlen != sizeof(del))
563 rc = -EIO;
564
565 if (rc) {
566 printk(KERN_ERR PREFIX "error writing '%s' at "
567 "0x%lx\n", part->mbd.mtd->name, addr);
568 goto err;
569 }
570 if (block == part->current_block)
571 part->header_cache[offset + HEADER_MAP_OFFSET] = del;
572
573 part->blocks[block].used_sectors--;
574
575 if (!part->blocks[block].used_sectors &&
576 !part->blocks[block].free_sectors)
577 rc = erase_block(part, block);
578
579err:
580 return rc;
581}
582
583static int find_free_sector(const struct partition *part, const struct block *block)
584{
585 int i, stop;
586
587 i = stop = part->data_sectors_per_block - block->free_sectors;
588
589 do {
590 if (le16_to_cpu(part->header_cache[HEADER_MAP_OFFSET + i])
591 == SECTOR_FREE)
592 return i;
593
594 if (++i == part->data_sectors_per_block)
595 i = 0;
596 }
597 while(i != stop);
598
599 return -1;
600}
601
602static int do_writesect(struct mtd_blktrans_dev *dev, u_long sector, char *buf, ulong *old_addr)
603{
604 struct partition *part = (struct partition*)dev;
605 struct block *block;
606 u_long addr;
607 int i;
608 int rc;
609 size_t retlen;
610 u16 entry;
611
612 if (part->current_block == -1 ||
613 !part->blocks[part->current_block].free_sectors) {
614
615 rc = find_writable_block(part, old_addr);
616 if (rc)
617 goto err;
618 }
619
620 block = &part->blocks[part->current_block];
621
622 i = find_free_sector(part, block);
623
624 if (i < 0) {
625 rc = -ENOSPC;
626 goto err;
627 }
628
629 addr = (i + part->header_sectors_per_block) * SECTOR_SIZE +
630 block->offset;
631 rc = mtd_write(part->mbd.mtd, addr, SECTOR_SIZE, &retlen,
632 (u_char *)buf);
633
634 if (!rc && retlen != SECTOR_SIZE)
635 rc = -EIO;
636
637 if (rc) {
638 printk(KERN_ERR PREFIX "error writing '%s' at 0x%lx\n",
639 part->mbd.mtd->name, addr);
640 goto err;
641 }
642
643 part->sector_map[sector] = addr;
644
645 entry = cpu_to_le16(sector == 0 ? SECTOR_ZERO : sector);
646
647 part->header_cache[i + HEADER_MAP_OFFSET] = entry;
648
649 addr = block->offset + (HEADER_MAP_OFFSET + i) * sizeof(u16);
650 rc = mtd_write(part->mbd.mtd, addr, sizeof(entry), &retlen,
651 (u_char *)&entry);
652
653 if (!rc && retlen != sizeof(entry))
654 rc = -EIO;
655
656 if (rc) {
657 printk(KERN_ERR PREFIX "error writing '%s' at 0x%lx\n",
658 part->mbd.mtd->name, addr);
659 goto err;
660 }
661 block->used_sectors++;
662 block->free_sectors--;
663
664err:
665 return rc;
666}
667
668static int rfd_ftl_writesect(struct mtd_blktrans_dev *dev, u_long sector, char *buf)
669{
670 struct partition *part = (struct partition*)dev;
671 u_long old_addr;
672 int i;
673 int rc = 0;
674
675 pr_debug("rfd_ftl_writesect(sector=0x%lx)\n", sector);
676
677 if (part->reserved_block == -1) {
678 rc = -EACCES;
679 goto err;
680 }
681
682 if (sector >= part->sector_count) {
683 rc = -EIO;
684 goto err;
685 }
686
687 old_addr = part->sector_map[sector];
688
689 for (i=0; i<SECTOR_SIZE; i++) {
690 if (!buf[i])
691 continue;
692
693 rc = do_writesect(dev, sector, buf, &old_addr);
694 if (rc)
695 goto err;
696 break;
697 }
698
699 if (i == SECTOR_SIZE)
700 part->sector_map[sector] = -1;
701
702 if (old_addr != -1)
703 rc = mark_sector_deleted(part, old_addr);
704
705err:
706 return rc;
707}
708
709static int rfd_ftl_getgeo(struct mtd_blktrans_dev *dev, struct hd_geometry *geo)
710{
711 struct partition *part = (struct partition*)dev;
712
713 geo->heads = 1;
714 geo->sectors = SECTORS_PER_TRACK;
715 geo->cylinders = part->cylinders;
716
717 return 0;
718}
719
720static void rfd_ftl_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
721{
722 struct partition *part;
723
724 if (mtd->type != MTD_NORFLASH || mtd->size > UINT_MAX)
725 return;
726
727 part = kzalloc(sizeof(struct partition), GFP_KERNEL);
728 if (!part)
729 return;
730
731 part->mbd.mtd = mtd;
732
733 if (block_size)
734 part->block_size = block_size;
735 else {
736 if (!mtd->erasesize) {
737 printk(KERN_WARNING PREFIX "please provide block_size");
738 goto out;
739 } else
740 part->block_size = mtd->erasesize;
741 }
742
743 if (scan_header(part) == 0) {
744 part->mbd.size = part->sector_count;
745 part->mbd.tr = tr;
746 part->mbd.devnum = -1;
747 if (!(mtd->flags & MTD_WRITEABLE))
748 part->mbd.readonly = 1;
749 else if (part->errors) {
750 printk(KERN_WARNING PREFIX "'%s': errors found, "
751 "setting read-only\n", mtd->name);
752 part->mbd.readonly = 1;
753 }
754
755 printk(KERN_INFO PREFIX "name: '%s' type: %d flags %x\n",
756 mtd->name, mtd->type, mtd->flags);
757
758 if (!add_mtd_blktrans_dev((void*)part))
759 return;
760 }
761out:
762 kfree(part);
763}
764
765static void rfd_ftl_remove_dev(struct mtd_blktrans_dev *dev)
766{
767 struct partition *part = (struct partition*)dev;
768 int i;
769
770 for (i=0; i<part->total_blocks; i++) {
771 pr_debug("rfd_ftl_remove_dev:'%s': erase unit #%02d: %d erases\n",
772 part->mbd.mtd->name, i, part->blocks[i].erases);
773 }
774
775 del_mtd_blktrans_dev(dev);
776 vfree(part->sector_map);
777 kfree(part->header_cache);
778 kfree(part->blocks);
779}
780
781static struct mtd_blktrans_ops rfd_ftl_tr = {
782 .name = "rfd",
783 .major = RFD_FTL_MAJOR,
784 .part_bits = PART_BITS,
785 .blksize = SECTOR_SIZE,
786
787 .readsect = rfd_ftl_readsect,
788 .writesect = rfd_ftl_writesect,
789 .getgeo = rfd_ftl_getgeo,
790 .add_mtd = rfd_ftl_add_mtd,
791 .remove_dev = rfd_ftl_remove_dev,
792 .owner = THIS_MODULE,
793};
794
795static int __init init_rfd_ftl(void)
796{
797 return register_mtd_blktrans(&rfd_ftl_tr);
798}
799
800static void __exit cleanup_rfd_ftl(void)
801{
802 deregister_mtd_blktrans(&rfd_ftl_tr);
803}
804
805module_init(init_rfd_ftl);
806module_exit(cleanup_rfd_ftl);
807
808MODULE_LICENSE("GPL");
809MODULE_AUTHOR("Sean Young <sean@mess.org>");
810MODULE_DESCRIPTION("Support code for RFD Flash Translation Layer, "
811 "used by General Software's Embedded BIOS");
812
813
