1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Linux driver for NAND Flash Translation Layer 4 * 5 * Copyright © 1999 Machine Vision Holdings, Inc. 6 * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org> 7 */ 8 9 #define PRERELEASE 10 11 #include <linux/kernel.h> 12 #include <linux/module.h> 13 #include <asm/errno.h> 14 #include <asm/io.h> 15 #include <linux/uaccess.h> 16 #include <linux/delay.h> 17 #include <linux/slab.h> 18 #include <linux/init.h> 19 #include <linux/hdreg.h> 20 #include <linux/blkdev.h> 21 22 #include <linux/kmod.h> 23 #include <linux/mtd/mtd.h> 24 #include <linux/mtd/rawnand.h> 25 #include <linux/mtd/nftl.h> 26 #include <linux/mtd/blktrans.h> 27 28 /* maximum number of loops while examining next block, to have a 29 chance to detect consistency problems (they should never happen 30 because of the checks done in the mounting */ 31 32 #define MAX_LOOPS 10000 33 34 35 static void nftl_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd) 36 { 37 struct NFTLrecord *nftl; 38 unsigned long temp; 39 40 if (!mtd_type_is_nand(mtd) || mtd->size > UINT_MAX) 41 return; 42 /* OK, this is moderately ugly. But probably safe. Alternatives? */ 43 if (memcmp(mtd->name, "DiskOnChip", 10)) 44 return; 45 46 pr_debug("NFTL: add_mtd for %s\n", mtd->name); 47 48 nftl = kzalloc(sizeof(struct NFTLrecord), GFP_KERNEL); 49 50 if (!nftl) 51 return; 52 53 nftl->mbd.mtd = mtd; 54 nftl->mbd.devnum = -1; 55 56 nftl->mbd.tr = tr; 57 58 if (NFTL_mount(nftl) < 0) { 59 printk(KERN_WARNING "NFTL: could not mount device\n"); 60 kfree(nftl); 61 return; 62 } 63 64 /* OK, it's a new one. Set up all the data structures. */ 65 66 /* Calculate geometry */ 67 nftl->cylinders = 1024; 68 nftl->heads = 16; 69 70 temp = nftl->cylinders * nftl->heads; 71 nftl->sectors = nftl->mbd.size / temp; 72 if (nftl->mbd.size % temp) { 73 nftl->sectors++; 74 temp = nftl->cylinders * nftl->sectors; 75 nftl->heads = nftl->mbd.size / temp; 76 77 if (nftl->mbd.size % temp) { 78 nftl->heads++; 79 temp = nftl->heads * nftl->sectors; 80 nftl->cylinders = nftl->mbd.size / temp; 81 } 82 } 83 84 if (nftl->mbd.size != nftl->heads * nftl->cylinders * nftl->sectors) { 85 /* 86 Oh no we don't have 87 mbd.size == heads * cylinders * sectors 88 */ 89 printk(KERN_WARNING "NFTL: cannot calculate a geometry to " 90 "match size of 0x%lx.\n", nftl->mbd.size); 91 printk(KERN_WARNING "NFTL: using C:%d H:%d S:%d " 92 "(== 0x%lx sects)\n", 93 nftl->cylinders, nftl->heads , nftl->sectors, 94 (long)nftl->cylinders * (long)nftl->heads * 95 (long)nftl->sectors ); 96 } 97 98 if (add_mtd_blktrans_dev(&nftl->mbd)) { 99 kfree(nftl->ReplUnitTable); 100 kfree(nftl->EUNtable); 101 kfree(nftl); 102 return; 103 } 104 #ifdef PSYCHO_DEBUG 105 printk(KERN_INFO "NFTL: Found new nftl%c\n", nftl->mbd.devnum + 'a'); 106 #endif 107 } 108 109 static void nftl_remove_dev(struct mtd_blktrans_dev *dev) 110 { 111 struct NFTLrecord *nftl = (void *)dev; 112 113 pr_debug("NFTL: remove_dev (i=%d)\n", dev->devnum); 114 115 del_mtd_blktrans_dev(dev); 116 kfree(nftl->ReplUnitTable); 117 kfree(nftl->EUNtable); 118 } 119 120 /* 121 * Read oob data from flash 122 */ 123 int nftl_read_oob(struct mtd_info *mtd, loff_t offs, size_t len, 124 size_t *retlen, uint8_t *buf) 125 { 126 loff_t mask = mtd->writesize - 1; 127 struct mtd_oob_ops ops; 128 int res; 129 130 ops.mode = MTD_OPS_PLACE_OOB; 131 ops.ooboffs = offs & mask; 132 ops.ooblen = len; 133 ops.oobbuf = buf; 134 ops.datbuf = NULL; 135 136 res = mtd_read_oob(mtd, offs & ~mask, &ops); 137 *retlen = ops.oobretlen; 138 return res; 139 } 140 141 /* 142 * Write oob data to flash 143 */ 144 int nftl_write_oob(struct mtd_info *mtd, loff_t offs, size_t len, 145 size_t *retlen, uint8_t *buf) 146 { 147 loff_t mask = mtd->writesize - 1; 148 struct mtd_oob_ops ops; 149 int res; 150 151 ops.mode = MTD_OPS_PLACE_OOB; 152 ops.ooboffs = offs & mask; 153 ops.ooblen = len; 154 ops.oobbuf = buf; 155 ops.datbuf = NULL; 156 157 res = mtd_write_oob(mtd, offs & ~mask, &ops); 158 *retlen = ops.oobretlen; 159 return res; 160 } 161 162 #ifdef CONFIG_NFTL_RW 163 164 /* 165 * Write data and oob to flash 166 */ 167 static int nftl_write(struct mtd_info *mtd, loff_t offs, size_t len, 168 size_t *retlen, uint8_t *buf, uint8_t *oob) 169 { 170 loff_t mask = mtd->writesize - 1; 171 struct mtd_oob_ops ops; 172 int res; 173 174 ops.mode = MTD_OPS_PLACE_OOB; 175 ops.ooboffs = offs & mask; 176 ops.ooblen = mtd->oobsize; 177 ops.oobbuf = oob; 178 ops.datbuf = buf; 179 ops.len = len; 180 181 res = mtd_write_oob(mtd, offs & ~mask, &ops); 182 *retlen = ops.retlen; 183 return res; 184 } 185 186 /* Actual NFTL access routines */ 187 /* NFTL_findfreeblock: Find a free Erase Unit on the NFTL partition. This function is used 188 * when the give Virtual Unit Chain 189 */ 190 static u16 NFTL_findfreeblock(struct NFTLrecord *nftl, int desperate ) 191 { 192 /* For a given Virtual Unit Chain: find or create a free block and 193 add it to the chain */ 194 /* We're passed the number of the last EUN in the chain, to save us from 195 having to look it up again */ 196 u16 pot = nftl->LastFreeEUN; 197 int silly = nftl->nb_blocks; 198 199 /* Normally, we force a fold to happen before we run out of free blocks completely */ 200 if (!desperate && nftl->numfreeEUNs < 2) { 201 pr_debug("NFTL_findfreeblock: there are too few free EUNs\n"); 202 return BLOCK_NIL; 203 } 204 205 /* Scan for a free block */ 206 do { 207 if (nftl->ReplUnitTable[pot] == BLOCK_FREE) { 208 nftl->LastFreeEUN = pot; 209 nftl->numfreeEUNs--; 210 return pot; 211 } 212 213 /* This will probably point to the MediaHdr unit itself, 214 right at the beginning of the partition. But that unit 215 (and the backup unit too) should have the UCI set 216 up so that it's not selected for overwriting */ 217 if (++pot > nftl->lastEUN) 218 pot = le16_to_cpu(nftl->MediaHdr.FirstPhysicalEUN); 219 220 if (!silly--) { 221 printk("Argh! No free blocks found! LastFreeEUN = %d, " 222 "FirstEUN = %d\n", nftl->LastFreeEUN, 223 le16_to_cpu(nftl->MediaHdr.FirstPhysicalEUN)); 224 return BLOCK_NIL; 225 } 226 } while (pot != nftl->LastFreeEUN); 227 228 return BLOCK_NIL; 229 } 230 231 static u16 NFTL_foldchain (struct NFTLrecord *nftl, unsigned thisVUC, unsigned pendingblock ) 232 { 233 struct mtd_info *mtd = nftl->mbd.mtd; 234 u16 BlockMap[MAX_SECTORS_PER_UNIT]; 235 unsigned char BlockLastState[MAX_SECTORS_PER_UNIT]; 236 unsigned char BlockFreeFound[MAX_SECTORS_PER_UNIT]; 237 unsigned int thisEUN; 238 int block; 239 int silly; 240 unsigned int targetEUN; 241 struct nftl_oob oob; 242 int inplace = 1; 243 size_t retlen; 244 245 memset(BlockMap, 0xff, sizeof(BlockMap)); 246 memset(BlockFreeFound, 0, sizeof(BlockFreeFound)); 247 248 thisEUN = nftl->EUNtable[thisVUC]; 249 250 if (thisEUN == BLOCK_NIL) { 251 printk(KERN_WARNING "Trying to fold non-existent " 252 "Virtual Unit Chain %d!\n", thisVUC); 253 return BLOCK_NIL; 254 } 255 256 /* Scan to find the Erase Unit which holds the actual data for each 257 512-byte block within the Chain. 258 */ 259 silly = MAX_LOOPS; 260 targetEUN = BLOCK_NIL; 261 while (thisEUN <= nftl->lastEUN ) { 262 unsigned int status, foldmark; 263 264 targetEUN = thisEUN; 265 for (block = 0; block < nftl->EraseSize / 512; block ++) { 266 nftl_read_oob(mtd, (thisEUN * nftl->EraseSize) + 267 (block * 512), 16 , &retlen, 268 (char *)&oob); 269 if (block == 2) { 270 foldmark = oob.u.c.FoldMark | oob.u.c.FoldMark1; 271 if (foldmark == FOLD_MARK_IN_PROGRESS) { 272 pr_debug("Write Inhibited on EUN %d\n", thisEUN); 273 inplace = 0; 274 } else { 275 /* There's no other reason not to do inplace, 276 except ones that come later. So we don't need 277 to preserve inplace */ 278 inplace = 1; 279 } 280 } 281 status = oob.b.Status | oob.b.Status1; 282 BlockLastState[block] = status; 283 284 switch(status) { 285 case SECTOR_FREE: 286 BlockFreeFound[block] = 1; 287 break; 288 289 case SECTOR_USED: 290 if (!BlockFreeFound[block]) 291 BlockMap[block] = thisEUN; 292 else 293 printk(KERN_WARNING 294 "SECTOR_USED found after SECTOR_FREE " 295 "in Virtual Unit Chain %d for block %d\n", 296 thisVUC, block); 297 break; 298 case SECTOR_DELETED: 299 if (!BlockFreeFound[block]) 300 BlockMap[block] = BLOCK_NIL; 301 else 302 printk(KERN_WARNING 303 "SECTOR_DELETED found after SECTOR_FREE " 304 "in Virtual Unit Chain %d for block %d\n", 305 thisVUC, block); 306 break; 307 308 case SECTOR_IGNORE: 309 break; 310 default: 311 printk("Unknown status for block %d in EUN %d: %x\n", 312 block, thisEUN, status); 313 } 314 } 315 316 if (!silly--) { 317 printk(KERN_WARNING "Infinite loop in Virtual Unit Chain 0x%x\n", 318 thisVUC); 319 return BLOCK_NIL; 320 } 321 322 thisEUN = nftl->ReplUnitTable[thisEUN]; 323 } 324 325 if (inplace) { 326 /* We're being asked to be a fold-in-place. Check 327 that all blocks which actually have data associated 328 with them (i.e. BlockMap[block] != BLOCK_NIL) are 329 either already present or SECTOR_FREE in the target 330 block. If not, we're going to have to fold out-of-place 331 anyway. 332 */ 333 for (block = 0; block < nftl->EraseSize / 512 ; block++) { 334 if (BlockLastState[block] != SECTOR_FREE && 335 BlockMap[block] != BLOCK_NIL && 336 BlockMap[block] != targetEUN) { 337 pr_debug("Setting inplace to 0. VUC %d, " 338 "block %d was %x lastEUN, " 339 "and is in EUN %d (%s) %d\n", 340 thisVUC, block, BlockLastState[block], 341 BlockMap[block], 342 BlockMap[block]== targetEUN ? "==" : "!=", 343 targetEUN); 344 inplace = 0; 345 break; 346 } 347 } 348 349 if (pendingblock >= (thisVUC * (nftl->EraseSize / 512)) && 350 pendingblock < ((thisVUC + 1)* (nftl->EraseSize / 512)) && 351 BlockLastState[pendingblock - (thisVUC * (nftl->EraseSize / 512))] != 352 SECTOR_FREE) { 353 pr_debug("Pending write not free in EUN %d. " 354 "Folding out of place.\n", targetEUN); 355 inplace = 0; 356 } 357 } 358 359 if (!inplace) { 360 pr_debug("Cannot fold Virtual Unit Chain %d in place. " 361 "Trying out-of-place\n", thisVUC); 362 /* We need to find a targetEUN to fold into. */ 363 targetEUN = NFTL_findfreeblock(nftl, 1); 364 if (targetEUN == BLOCK_NIL) { 365 /* Ouch. Now we're screwed. We need to do a 366 fold-in-place of another chain to make room 367 for this one. We need a better way of selecting 368 which chain to fold, because makefreeblock will 369 only ask us to fold the same one again. 370 */ 371 printk(KERN_WARNING 372 "NFTL_findfreeblock(desperate) returns 0xffff.\n"); 373 return BLOCK_NIL; 374 } 375 } else { 376 /* We put a fold mark in the chain we are folding only if we 377 fold in place to help the mount check code. If we do not fold in 378 place, it is possible to find the valid chain by selecting the 379 longer one */ 380 oob.u.c.FoldMark = oob.u.c.FoldMark1 = cpu_to_le16(FOLD_MARK_IN_PROGRESS); 381 oob.u.c.unused = 0xffffffff; 382 nftl_write_oob(mtd, (nftl->EraseSize * targetEUN) + 2 * 512 + 8, 383 8, &retlen, (char *)&oob.u); 384 } 385 386 /* OK. We now know the location of every block in the Virtual Unit Chain, 387 and the Erase Unit into which we are supposed to be copying. 388 Go for it. 389 */ 390 pr_debug("Folding chain %d into unit %d\n", thisVUC, targetEUN); 391 for (block = 0; block < nftl->EraseSize / 512 ; block++) { 392 unsigned char movebuf[512]; 393 int ret; 394 395 /* If it's in the target EUN already, or if it's pending write, do nothing */ 396 if (BlockMap[block] == targetEUN || 397 (pendingblock == (thisVUC * (nftl->EraseSize / 512) + block))) { 398 continue; 399 } 400 401 /* copy only in non free block (free blocks can only 402 happen in case of media errors or deleted blocks) */ 403 if (BlockMap[block] == BLOCK_NIL) 404 continue; 405 406 ret = mtd_read(mtd, 407 (nftl->EraseSize * BlockMap[block]) + (block * 512), 408 512, 409 &retlen, 410 movebuf); 411 if (ret < 0 && !mtd_is_bitflip(ret)) { 412 ret = mtd_read(mtd, 413 (nftl->EraseSize * BlockMap[block]) + (block * 512), 414 512, 415 &retlen, 416 movebuf); 417 if (ret != -EIO) 418 printk("Error went away on retry.\n"); 419 } 420 memset(&oob, 0xff, sizeof(struct nftl_oob)); 421 oob.b.Status = oob.b.Status1 = SECTOR_USED; 422 423 nftl_write(nftl->mbd.mtd, (nftl->EraseSize * targetEUN) + 424 (block * 512), 512, &retlen, movebuf, (char *)&oob); 425 } 426 427 /* add the header so that it is now a valid chain */ 428 oob.u.a.VirtUnitNum = oob.u.a.SpareVirtUnitNum = cpu_to_le16(thisVUC); 429 oob.u.a.ReplUnitNum = oob.u.a.SpareReplUnitNum = BLOCK_NIL; 430 431 nftl_write_oob(mtd, (nftl->EraseSize * targetEUN) + 8, 432 8, &retlen, (char *)&oob.u); 433 434 /* OK. We've moved the whole lot into the new block. Now we have to free the original blocks. */ 435 436 /* At this point, we have two different chains for this Virtual Unit, and no way to tell 437 them apart. If we crash now, we get confused. However, both contain the same data, so we 438 shouldn't actually lose data in this case. It's just that when we load up on a medium which 439 has duplicate chains, we need to free one of the chains because it's not necessary any more. 440 */ 441 thisEUN = nftl->EUNtable[thisVUC]; 442 pr_debug("Want to erase\n"); 443 444 /* For each block in the old chain (except the targetEUN of course), 445 free it and make it available for future use */ 446 while (thisEUN <= nftl->lastEUN && thisEUN != targetEUN) { 447 unsigned int EUNtmp; 448 449 EUNtmp = nftl->ReplUnitTable[thisEUN]; 450 451 if (NFTL_formatblock(nftl, thisEUN) < 0) { 452 /* could not erase : mark block as reserved 453 */ 454 nftl->ReplUnitTable[thisEUN] = BLOCK_RESERVED; 455 } else { 456 /* correctly erased : mark it as free */ 457 nftl->ReplUnitTable[thisEUN] = BLOCK_FREE; 458 nftl->numfreeEUNs++; 459 } 460 thisEUN = EUNtmp; 461 } 462 463 /* Make this the new start of chain for thisVUC */ 464 nftl->ReplUnitTable[targetEUN] = BLOCK_NIL; 465 nftl->EUNtable[thisVUC] = targetEUN; 466 467 return targetEUN; 468 } 469 470 static u16 NFTL_makefreeblock( struct NFTLrecord *nftl , unsigned pendingblock) 471 { 472 /* This is the part that needs some cleverness applied. 473 For now, I'm doing the minimum applicable to actually 474 get the thing to work. 475 Wear-levelling and other clever stuff needs to be implemented 476 and we also need to do some assessment of the results when 477 the system loses power half-way through the routine. 478 */ 479 u16 LongestChain = 0; 480 u16 ChainLength = 0, thislen; 481 u16 chain, EUN; 482 483 for (chain = 0; chain < le32_to_cpu(nftl->MediaHdr.FormattedSize) / nftl->EraseSize; chain++) { 484 EUN = nftl->EUNtable[chain]; 485 thislen = 0; 486 487 while (EUN <= nftl->lastEUN) { 488 thislen++; 489 //printk("VUC %d reaches len %d with EUN %d\n", chain, thislen, EUN); 490 EUN = nftl->ReplUnitTable[EUN] & 0x7fff; 491 if (thislen > 0xff00) { 492 printk("Endless loop in Virtual Chain %d: Unit %x\n", 493 chain, EUN); 494 } 495 if (thislen > 0xff10) { 496 /* Actually, don't return failure. Just ignore this chain and 497 get on with it. */ 498 thislen = 0; 499 break; 500 } 501 } 502 503 if (thislen > ChainLength) { 504 //printk("New longest chain is %d with length %d\n", chain, thislen); 505 ChainLength = thislen; 506 LongestChain = chain; 507 } 508 } 509 510 if (ChainLength < 2) { 511 printk(KERN_WARNING "No Virtual Unit Chains available for folding. " 512 "Failing request\n"); 513 return BLOCK_NIL; 514 } 515 516 return NFTL_foldchain (nftl, LongestChain, pendingblock); 517 } 518 519 /* NFTL_findwriteunit: Return the unit number into which we can write 520 for this block. Make it available if it isn't already 521 */ 522 static inline u16 NFTL_findwriteunit(struct NFTLrecord *nftl, unsigned block) 523 { 524 u16 lastEUN; 525 u16 thisVUC = block / (nftl->EraseSize / 512); 526 struct mtd_info *mtd = nftl->mbd.mtd; 527 unsigned int writeEUN; 528 unsigned long blockofs = (block * 512) & (nftl->EraseSize -1); 529 size_t retlen; 530 int silly, silly2 = 3; 531 struct nftl_oob oob; 532 533 do { 534 /* Scan the media to find a unit in the VUC which has 535 a free space for the block in question. 536 */ 537 538 /* This condition catches the 0x[7f]fff cases, as well as 539 being a sanity check for past-end-of-media access 540 */ 541 lastEUN = BLOCK_NIL; 542 writeEUN = nftl->EUNtable[thisVUC]; 543 silly = MAX_LOOPS; 544 while (writeEUN <= nftl->lastEUN) { 545 struct nftl_bci bci; 546 size_t retlen; 547 unsigned int status; 548 549 lastEUN = writeEUN; 550 551 nftl_read_oob(mtd, 552 (writeEUN * nftl->EraseSize) + blockofs, 553 8, &retlen, (char *)&bci); 554 555 pr_debug("Status of block %d in EUN %d is %x\n", 556 block , writeEUN, le16_to_cpu(bci.Status)); 557 558 status = bci.Status | bci.Status1; 559 switch(status) { 560 case SECTOR_FREE: 561 return writeEUN; 562 563 case SECTOR_DELETED: 564 case SECTOR_USED: 565 case SECTOR_IGNORE: 566 break; 567 default: 568 // Invalid block. Don't use it any more. Must implement. 569 break; 570 } 571 572 if (!silly--) { 573 printk(KERN_WARNING 574 "Infinite loop in Virtual Unit Chain 0x%x\n", 575 thisVUC); 576 return BLOCK_NIL; 577 } 578 579 /* Skip to next block in chain */ 580 writeEUN = nftl->ReplUnitTable[writeEUN]; 581 } 582 583 /* OK. We didn't find one in the existing chain, or there 584 is no existing chain. */ 585 586 /* Try to find an already-free block */ 587 writeEUN = NFTL_findfreeblock(nftl, 0); 588 589 if (writeEUN == BLOCK_NIL) { 590 /* That didn't work - there were no free blocks just 591 waiting to be picked up. We're going to have to fold 592 a chain to make room. 593 */ 594 595 /* First remember the start of this chain */ 596 //u16 startEUN = nftl->EUNtable[thisVUC]; 597 598 //printk("Write to VirtualUnitChain %d, calling makefreeblock()\n", thisVUC); 599 writeEUN = NFTL_makefreeblock(nftl, BLOCK_NIL); 600 601 if (writeEUN == BLOCK_NIL) { 602 /* OK, we accept that the above comment is 603 lying - there may have been free blocks 604 last time we called NFTL_findfreeblock(), 605 but they are reserved for when we're 606 desperate. Well, now we're desperate. 607 */ 608 pr_debug("Using desperate==1 to find free EUN to accommodate write to VUC %d\n", thisVUC); 609 writeEUN = NFTL_findfreeblock(nftl, 1); 610 } 611 if (writeEUN == BLOCK_NIL) { 612 /* Ouch. This should never happen - we should 613 always be able to make some room somehow. 614 If we get here, we've allocated more storage 615 space than actual media, or our makefreeblock 616 routine is missing something. 617 */ 618 printk(KERN_WARNING "Cannot make free space.\n"); 619 return BLOCK_NIL; 620 } 621 //printk("Restarting scan\n"); 622 lastEUN = BLOCK_NIL; 623 continue; 624 } 625 626 /* We've found a free block. Insert it into the chain. */ 627 628 if (lastEUN != BLOCK_NIL) { 629 thisVUC |= 0x8000; /* It's a replacement block */ 630 } else { 631 /* The first block in a new chain */ 632 nftl->EUNtable[thisVUC] = writeEUN; 633 } 634 635 /* set up the actual EUN we're writing into */ 636 /* Both in our cache... */ 637 nftl->ReplUnitTable[writeEUN] = BLOCK_NIL; 638 639 /* ... and on the flash itself */ 640 nftl_read_oob(mtd, writeEUN * nftl->EraseSize + 8, 8, 641 &retlen, (char *)&oob.u); 642 643 oob.u.a.VirtUnitNum = oob.u.a.SpareVirtUnitNum = cpu_to_le16(thisVUC); 644 645 nftl_write_oob(mtd, writeEUN * nftl->EraseSize + 8, 8, 646 &retlen, (char *)&oob.u); 647 648 /* we link the new block to the chain only after the 649 block is ready. It avoids the case where the chain 650 could point to a free block */ 651 if (lastEUN != BLOCK_NIL) { 652 /* Both in our cache... */ 653 nftl->ReplUnitTable[lastEUN] = writeEUN; 654 /* ... and on the flash itself */ 655 nftl_read_oob(mtd, (lastEUN * nftl->EraseSize) + 8, 656 8, &retlen, (char *)&oob.u); 657 658 oob.u.a.ReplUnitNum = oob.u.a.SpareReplUnitNum 659 = cpu_to_le16(writeEUN); 660 661 nftl_write_oob(mtd, (lastEUN * nftl->EraseSize) + 8, 662 8, &retlen, (char *)&oob.u); 663 } 664 665 return writeEUN; 666 667 } while (silly2--); 668 669 printk(KERN_WARNING "Error folding to make room for Virtual Unit Chain 0x%x\n", 670 thisVUC); 671 return BLOCK_NIL; 672 } 673 674 static int nftl_writeblock(struct mtd_blktrans_dev *mbd, unsigned long block, 675 char *buffer) 676 { 677 struct NFTLrecord *nftl = (void *)mbd; 678 u16 writeEUN; 679 unsigned long blockofs = (block * 512) & (nftl->EraseSize - 1); 680 size_t retlen; 681 struct nftl_oob oob; 682 683 writeEUN = NFTL_findwriteunit(nftl, block); 684 685 if (writeEUN == BLOCK_NIL) { 686 printk(KERN_WARNING 687 "NFTL_writeblock(): Cannot find block to write to\n"); 688 /* If we _still_ haven't got a block to use, we're screwed */ 689 return 1; 690 } 691 692 memset(&oob, 0xff, sizeof(struct nftl_oob)); 693 oob.b.Status = oob.b.Status1 = SECTOR_USED; 694 695 nftl_write(nftl->mbd.mtd, (writeEUN * nftl->EraseSize) + blockofs, 696 512, &retlen, (char *)buffer, (char *)&oob); 697 return 0; 698 } 699 #endif /* CONFIG_NFTL_RW */ 700 701 static int nftl_readblock(struct mtd_blktrans_dev *mbd, unsigned long block, 702 char *buffer) 703 { 704 struct NFTLrecord *nftl = (void *)mbd; 705 struct mtd_info *mtd = nftl->mbd.mtd; 706 u16 lastgoodEUN; 707 u16 thisEUN = nftl->EUNtable[block / (nftl->EraseSize / 512)]; 708 unsigned long blockofs = (block * 512) & (nftl->EraseSize - 1); 709 unsigned int status; 710 int silly = MAX_LOOPS; 711 size_t retlen; 712 struct nftl_bci bci; 713 714 lastgoodEUN = BLOCK_NIL; 715 716 if (thisEUN != BLOCK_NIL) { 717 while (thisEUN < nftl->nb_blocks) { 718 if (nftl_read_oob(mtd, (thisEUN * nftl->EraseSize) + 719 blockofs, 8, &retlen, 720 (char *)&bci) < 0) 721 status = SECTOR_IGNORE; 722 else 723 status = bci.Status | bci.Status1; 724 725 switch (status) { 726 case SECTOR_FREE: 727 /* no modification of a sector should follow a free sector */ 728 goto the_end; 729 case SECTOR_DELETED: 730 lastgoodEUN = BLOCK_NIL; 731 break; 732 case SECTOR_USED: 733 lastgoodEUN = thisEUN; 734 break; 735 case SECTOR_IGNORE: 736 break; 737 default: 738 printk("Unknown status for block %ld in EUN %d: %x\n", 739 block, thisEUN, status); 740 break; 741 } 742 743 if (!silly--) { 744 printk(KERN_WARNING "Infinite loop in Virtual Unit Chain 0x%lx\n", 745 block / (nftl->EraseSize / 512)); 746 return 1; 747 } 748 thisEUN = nftl->ReplUnitTable[thisEUN]; 749 } 750 } 751 752 the_end: 753 if (lastgoodEUN == BLOCK_NIL) { 754 /* the requested block is not on the media, return all 0x00 */ 755 memset(buffer, 0, 512); 756 } else { 757 loff_t ptr = (lastgoodEUN * nftl->EraseSize) + blockofs; 758 size_t retlen; 759 int res = mtd_read(mtd, ptr, 512, &retlen, buffer); 760 761 if (res < 0 && !mtd_is_bitflip(res)) 762 return -EIO; 763 } 764 return 0; 765 } 766 767 static int nftl_getgeo(struct mtd_blktrans_dev *dev, struct hd_geometry *geo) 768 { 769 struct NFTLrecord *nftl = (void *)dev; 770 771 geo->heads = nftl->heads; 772 geo->sectors = nftl->sectors; 773 geo->cylinders = nftl->cylinders; 774 775 return 0; 776 } 777 778 /**************************************************************************** 779 * 780 * Module stuff 781 * 782 ****************************************************************************/ 783 784 785 static struct mtd_blktrans_ops nftl_tr = { 786 .name = "nftl", 787 .major = NFTL_MAJOR, 788 .part_bits = NFTL_PARTN_BITS, 789 .blksize = 512, 790 .getgeo = nftl_getgeo, 791 .readsect = nftl_readblock, 792 #ifdef CONFIG_NFTL_RW 793 .writesect = nftl_writeblock, 794 #endif 795 .add_mtd = nftl_add_mtd, 796 .remove_dev = nftl_remove_dev, 797 .owner = THIS_MODULE, 798 }; 799 800 static int __init init_nftl(void) 801 { 802 return register_mtd_blktrans(&nftl_tr); 803 } 804 805 static void __exit cleanup_nftl(void) 806 { 807 deregister_mtd_blktrans(&nftl_tr); 808 } 809 810 module_init(init_nftl); 811 module_exit(cleanup_nftl); 812 813 MODULE_LICENSE("GPL"); 814 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>, Fabrice Bellard <fabrice.bellard@netgem.com> et al."); 815 MODULE_DESCRIPTION("Support code for NAND Flash Translation Layer, used on M-Systems DiskOnChip 2000 and Millennium"); 816 MODULE_ALIAS_BLOCKDEV_MAJOR(NFTL_MAJOR); 817