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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 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 = mtd_write(part->mbd.mtd, part->blocks[i].offset, sizeof(magic),
308 &retlen, (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
326static 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 = 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
353err:
354 return rc;
355}
356
357static 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 = mtd_read(part->mbd.mtd, part->blocks[block_no].offset,
375 part->header_size, &retlen, (u_char *)map);
376
377 if (!rc && retlen != part->header_size)
378 rc = -EIO;
379
380 if (rc) {
381 printk(KERN_ERR PREFIX "error reading '%s' at "
382 "0x%lx\n", part->mbd.mtd->name,
383 part->blocks[block_no].offset);
384
385 goto err;
386 }
387
388 for (i=0; i<part->data_sectors_per_block; i++) {
389 u16 entry = le16_to_cpu(map[HEADER_MAP_OFFSET + i]);
390 u_long addr;
391
392
393 if (entry == SECTOR_FREE || entry == SECTOR_DELETED)
394 continue;
395
396 if (entry == SECTOR_ZERO)
397 entry = 0;
398
399
400 if (entry >= part->sector_count)
401 continue;
402
403 addr = part->blocks[block_no].offset +
404 (i + part->header_sectors_per_block) * SECTOR_SIZE;
405
406 if (*old_sector == addr) {
407 *old_sector = -1;
408 if (!part->blocks[block_no].used_sectors--) {
409 rc = erase_block(part, block_no);
410 break;
411 }
412 continue;
413 }
414 rc = mtd_read(part->mbd.mtd, addr, SECTOR_SIZE, &retlen,
415 sector_data);
416
417 if (!rc && retlen != SECTOR_SIZE)
418 rc = -EIO;
419
420 if (rc) {
421 printk(KERN_ERR PREFIX "'%s': Unable to "
422 "read sector for relocation\n",
423 part->mbd.mtd->name);
424
425 goto err;
426 }
427
428 rc = rfd_ftl_writesect((struct mtd_blktrans_dev*)part,
429 entry, sector_data);
430
431 if (rc)
432 goto err;
433 }
434
435err:
436 kfree(map);
437err2:
438 kfree(sector_data);
439err3:
440 part->is_reclaiming = 0;
441
442 return rc;
443}
444
445static int reclaim_block(struct partition *part, u_long *old_sector)
446{
447 int block, best_block, score, old_sector_block;
448 int rc;
449
450
451 mtd_sync(part->mbd.mtd);
452
453 score = 0x7fffffff;
454 best_block = -1;
455 if (*old_sector != -1)
456 old_sector_block = *old_sector / part->block_size;
457 else
458 old_sector_block = -1;
459
460 for (block=0; block<part->total_blocks; block++) {
461 int this_score;
462
463 if (block == part->reserved_block)
464 continue;
465
466
467
468
469
470
471 if (part->blocks[block].free_sectors)
472 return 0;
473
474 this_score = part->blocks[block].used_sectors;
475
476 if (block == old_sector_block)
477 this_score--;
478 else {
479
480 if (part->blocks[block].used_sectors ==
481 part->data_sectors_per_block)
482 continue;
483 }
484
485 this_score += part->blocks[block].erases;
486
487 if (this_score < score) {
488 best_block = block;
489 score = this_score;
490 }
491 }
492
493 if (best_block == -1)
494 return -ENOSPC;
495
496 part->current_block = -1;
497 part->reserved_block = best_block;
498
499 pr_debug("reclaim_block: reclaiming block #%d with %d used "
500 "%d free sectors\n", best_block,
501 part->blocks[best_block].used_sectors,
502 part->blocks[best_block].free_sectors);
503
504 if (part->blocks[best_block].used_sectors)
505 rc = move_block_contents(part, best_block, old_sector);
506 else
507 rc = erase_block(part, best_block);
508
509 return rc;
510}
511
512
513
514
515
516
517static int find_free_block(struct partition *part)
518{
519 int block, stop;
520
521 block = part->current_block == -1 ?
522 jiffies % part->total_blocks : part->current_block;
523 stop = block;
524
525 do {
526 if (part->blocks[block].free_sectors &&
527 block != part->reserved_block)
528 return block;
529
530 if (part->blocks[block].state == BLOCK_UNUSED)
531 erase_block(part, block);
532
533 if (++block >= part->total_blocks)
534 block = 0;
535
536 } while (block != stop);
537
538 return -1;
539}
540
541static int find_writable_block(struct partition *part, u_long *old_sector)
542{
543 int rc, block;
544 size_t retlen;
545
546 block = find_free_block(part);
547
548 if (block == -1) {
549 if (!part->is_reclaiming) {
550 rc = reclaim_block(part, old_sector);
551 if (rc)
552 goto err;
553
554 block = find_free_block(part);
555 }
556
557 if (block == -1) {
558 rc = -ENOSPC;
559 goto err;
560 }
561 }
562
563 rc = mtd_read(part->mbd.mtd, part->blocks[block].offset,
564 part->header_size, &retlen,
565 (u_char *)part->header_cache);
566
567 if (!rc && retlen != part->header_size)
568 rc = -EIO;
569
570 if (rc) {
571 printk(KERN_ERR PREFIX "'%s': unable to read header at "
572 "0x%lx\n", part->mbd.mtd->name,
573 part->blocks[block].offset);
574 goto err;
575 }
576
577 part->current_block = block;
578
579err:
580 return rc;
581}
582
583static int mark_sector_deleted(struct partition *part, u_long old_addr)
584{
585 int block, offset, rc;
586 u_long addr;
587 size_t retlen;
588 u16 del = cpu_to_le16(SECTOR_DELETED);
589
590 block = old_addr / part->block_size;
591 offset = (old_addr % part->block_size) / SECTOR_SIZE -
592 part->header_sectors_per_block;
593
594 addr = part->blocks[block].offset +
595 (HEADER_MAP_OFFSET + offset) * sizeof(u16);
596 rc = mtd_write(part->mbd.mtd, addr, sizeof(del), &retlen,
597 (u_char *)&del);
598
599 if (!rc && retlen != sizeof(del))
600 rc = -EIO;
601
602 if (rc) {
603 printk(KERN_ERR PREFIX "error writing '%s' at "
604 "0x%lx\n", part->mbd.mtd->name, addr);
605 goto err;
606 }
607 if (block == part->current_block)
608 part->header_cache[offset + HEADER_MAP_OFFSET] = del;
609
610 part->blocks[block].used_sectors--;
611
612 if (!part->blocks[block].used_sectors &&
613 !part->blocks[block].free_sectors)
614 rc = erase_block(part, block);
615
616err:
617 return rc;
618}
619
620static int find_free_sector(const struct partition *part, const struct block *block)
621{
622 int i, stop;
623
624 i = stop = part->data_sectors_per_block - block->free_sectors;
625
626 do {
627 if (le16_to_cpu(part->header_cache[HEADER_MAP_OFFSET + i])
628 == SECTOR_FREE)
629 return i;
630
631 if (++i == part->data_sectors_per_block)
632 i = 0;
633 }
634 while(i != stop);
635
636 return -1;
637}
638
639static int do_writesect(struct mtd_blktrans_dev *dev, u_long sector, char *buf, ulong *old_addr)
640{
641 struct partition *part = (struct partition*)dev;
642 struct block *block;
643 u_long addr;
644 int i;
645 int rc;
646 size_t retlen;
647 u16 entry;
648
649 if (part->current_block == -1 ||
650 !part->blocks[part->current_block].free_sectors) {
651
652 rc = find_writable_block(part, old_addr);
653 if (rc)
654 goto err;
655 }
656
657 block = &part->blocks[part->current_block];
658
659 i = find_free_sector(part, block);
660
661 if (i < 0) {
662 rc = -ENOSPC;
663 goto err;
664 }
665
666 addr = (i + part->header_sectors_per_block) * SECTOR_SIZE +
667 block->offset;
668 rc = mtd_write(part->mbd.mtd, addr, SECTOR_SIZE, &retlen,
669 (u_char *)buf);
670
671 if (!rc && retlen != SECTOR_SIZE)
672 rc = -EIO;
673
674 if (rc) {
675 printk(KERN_ERR PREFIX "error writing '%s' at 0x%lx\n",
676 part->mbd.mtd->name, addr);
677 goto err;
678 }
679
680 part->sector_map[sector] = addr;
681
682 entry = cpu_to_le16(sector == 0 ? SECTOR_ZERO : sector);
683
684 part->header_cache[i + HEADER_MAP_OFFSET] = entry;
685
686 addr = block->offset + (HEADER_MAP_OFFSET + i) * sizeof(u16);
687 rc = mtd_write(part->mbd.mtd, addr, sizeof(entry), &retlen,
688 (u_char *)&entry);
689
690 if (!rc && retlen != sizeof(entry))
691 rc = -EIO;
692
693 if (rc) {
694 printk(KERN_ERR PREFIX "error writing '%s' at 0x%lx\n",
695 part->mbd.mtd->name, addr);
696 goto err;
697 }
698 block->used_sectors++;
699 block->free_sectors--;
700
701err:
702 return rc;
703}
704
705static int rfd_ftl_writesect(struct mtd_blktrans_dev *dev, u_long sector, char *buf)
706{
707 struct partition *part = (struct partition*)dev;
708 u_long old_addr;
709 int i;
710 int rc = 0;
711
712 pr_debug("rfd_ftl_writesect(sector=0x%lx)\n", sector);
713
714 if (part->reserved_block == -1) {
715 rc = -EACCES;
716 goto err;
717 }
718
719 if (sector >= part->sector_count) {
720 rc = -EIO;
721 goto err;
722 }
723
724 old_addr = part->sector_map[sector];
725
726 for (i=0; i<SECTOR_SIZE; i++) {
727 if (!buf[i])
728 continue;
729
730 rc = do_writesect(dev, sector, buf, &old_addr);
731 if (rc)
732 goto err;
733 break;
734 }
735
736 if (i == SECTOR_SIZE)
737 part->sector_map[sector] = -1;
738
739 if (old_addr != -1)
740 rc = mark_sector_deleted(part, old_addr);
741
742err:
743 return rc;
744}
745
746static int rfd_ftl_getgeo(struct mtd_blktrans_dev *dev, struct hd_geometry *geo)
747{
748 struct partition *part = (struct partition*)dev;
749
750 geo->heads = 1;
751 geo->sectors = SECTORS_PER_TRACK;
752 geo->cylinders = part->cylinders;
753
754 return 0;
755}
756
757static void rfd_ftl_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
758{
759 struct partition *part;
760
761 if (mtd->type != MTD_NORFLASH || mtd->size > UINT_MAX)
762 return;
763
764 part = kzalloc(sizeof(struct partition), GFP_KERNEL);
765 if (!part)
766 return;
767
768 part->mbd.mtd = mtd;
769
770 if (block_size)
771 part->block_size = block_size;
772 else {
773 if (!mtd->erasesize) {
774 printk(KERN_WARNING PREFIX "please provide block_size");
775 goto out;
776 } else
777 part->block_size = mtd->erasesize;
778 }
779
780 if (scan_header(part) == 0) {
781 part->mbd.size = part->sector_count;
782 part->mbd.tr = tr;
783 part->mbd.devnum = -1;
784 if (!(mtd->flags & MTD_WRITEABLE))
785 part->mbd.readonly = 1;
786 else if (part->errors) {
787 printk(KERN_WARNING PREFIX "'%s': errors found, "
788 "setting read-only\n", mtd->name);
789 part->mbd.readonly = 1;
790 }
791
792 printk(KERN_INFO PREFIX "name: '%s' type: %d flags %x\n",
793 mtd->name, mtd->type, mtd->flags);
794
795 if (!add_mtd_blktrans_dev((void*)part))
796 return;
797 }
798out:
799 kfree(part);
800}
801
802static void rfd_ftl_remove_dev(struct mtd_blktrans_dev *dev)
803{
804 struct partition *part = (struct partition*)dev;
805 int i;
806
807 for (i=0; i<part->total_blocks; i++) {
808 pr_debug("rfd_ftl_remove_dev:'%s': erase unit #%02d: %d erases\n",
809 part->mbd.mtd->name, i, part->blocks[i].erases);
810 }
811
812 del_mtd_blktrans_dev(dev);
813 vfree(part->sector_map);
814 kfree(part->header_cache);
815 kfree(part->blocks);
816}
817
818static struct mtd_blktrans_ops rfd_ftl_tr = {
819 .name = "rfd",
820 .major = RFD_FTL_MAJOR,
821 .part_bits = PART_BITS,
822 .blksize = SECTOR_SIZE,
823
824 .readsect = rfd_ftl_readsect,
825 .writesect = rfd_ftl_writesect,
826 .getgeo = rfd_ftl_getgeo,
827 .add_mtd = rfd_ftl_add_mtd,
828 .remove_dev = rfd_ftl_remove_dev,
829 .owner = THIS_MODULE,
830};
831
832static int __init init_rfd_ftl(void)
833{
834 return register_mtd_blktrans(&rfd_ftl_tr);
835}
836
837static void __exit cleanup_rfd_ftl(void)
838{
839 deregister_mtd_blktrans(&rfd_ftl_tr);
840}
841
842module_init(init_rfd_ftl);
843module_exit(cleanup_rfd_ftl);
844
845MODULE_LICENSE("GPL");
846MODULE_AUTHOR("Sean Young <sean@mess.org>");
847MODULE_DESCRIPTION("Support code for RFD Flash Translation Layer, "
848 "used by General Software's Embedded BIOS");
849
850
