drivers/mtd/rfd_ftl.c

   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 = 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
 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 = 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
 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 = 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
 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 = 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 = 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                 /* already warned about and ignored in build_block_map() */
 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
 435 err:
 436         kfree(map);
 437 err2:
 438         kfree(sector_data);
 439 err3:
 440         part->is_reclaiming = 0;
 441
 442         return rc;
 443 }
 444
 445 static 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         /* we have a race if sync doesn't exist */
 451         mtd_sync(part->mbd.mtd);
 452
 453         score = 0x7fffffff; /* MAX_INT */
 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                  * Postpone reclaiming if there is a free sector as
 468                  * more removed sectors is more efficient (have to move
 469                  * less).
 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                         /* no point in moving a full block */
 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  * IMPROVE: It would be best to choose the block with the most deleted sectors,
 514  * because if we fill that one up first it'll have the most chance of having
 515  * the least live sectors at reclaim.
 516  */
 517 static 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
 541 static 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
 579 err:
 580         return rc;
 581 }
 582
 583 static 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
 616 err:
 617         return rc;
 618 }
 619
 620 static 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
 639 static 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
 701 err:
 702         return rc;
 703 }
 704
 705 static 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
 742 err:
 743         return rc;
 744 }
 745
 746 static 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
 757 static 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         }
 798 out:
 799         kfree(part);
 800 }
 801
 802 static 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
 818 static 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
 832 static int __init init_rfd_ftl(void)
 833 {
 834         return register_mtd_blktrans(&rfd_ftl_tr);
 835 }
 836
 837 static void __exit cleanup_rfd_ftl(void)
 838 {
 839         deregister_mtd_blktrans(&rfd_ftl_tr);
 840 }
 841
 842 module_init(init_rfd_ftl);
 843 module_exit(cleanup_rfd_ftl);
 844
 845 MODULE_LICENSE("GPL");
 846 MODULE_AUTHOR("Sean Young <sean@mess.org>");
 847 MODULE_DESCRIPTION("Support code for RFD Flash Translation Layer, "
 848                 "used by General Software's Embedded BIOS");
 849