blob: 39eb53f6551f0d96943539ce0ce0a41aba1dc22f [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * inftlcore.c -- Linux driver for Inverse Flash Translation Layer (INFTL)
3 *
4 * (C) Copyright 2002, Greg Ungerer (gerg@snapgear.com)
5 *
6 * Based heavily on the nftlcore.c code which is:
7 * (c) 1999 Machine Vision Holdings, Inc.
8 * Author: David Woodhouse <dwmw2@infradead.org>
9 *
10 * $Id: inftlcore.c,v 1.18 2004/11/16 18:28:59 dwmw2 Exp $
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
16 *
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
21 *
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
25 */
26
27#include <linux/config.h>
28#include <linux/kernel.h>
29#include <linux/module.h>
30#include <linux/delay.h>
31#include <linux/slab.h>
32#include <linux/sched.h>
33#include <linux/init.h>
34#include <linux/kmod.h>
35#include <linux/hdreg.h>
36#include <linux/mtd/mtd.h>
37#include <linux/mtd/nftl.h>
38#include <linux/mtd/inftl.h>
39#include <asm/uaccess.h>
40#include <asm/errno.h>
41#include <asm/io.h>
42
43/*
44 * Maximum number of loops while examining next block, to have a
45 * chance to detect consistency problems (they should never happen
46 * because of the checks done in the mounting.
47 */
48#define MAX_LOOPS 10000
49
50extern void INFTL_dumptables(struct INFTLrecord *inftl);
51extern void INFTL_dumpVUchains(struct INFTLrecord *inftl);
52
53static void inftl_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
54{
55 struct INFTLrecord *inftl;
56 unsigned long temp;
57
58 if (mtd->type != MTD_NANDFLASH)
59 return;
60 /* OK, this is moderately ugly. But probably safe. Alternatives? */
61 if (memcmp(mtd->name, "DiskOnChip", 10))
62 return;
63
64 if (!mtd->block_isbad) {
65 printk(KERN_ERR
66"INFTL no longer supports the old DiskOnChip drivers loaded via docprobe.\n"
67"Please use the new diskonchip driver under the NAND subsystem.\n");
68 return;
69 }
70
71 DEBUG(MTD_DEBUG_LEVEL3, "INFTL: add_mtd for %s\n", mtd->name);
72
73 inftl = kmalloc(sizeof(*inftl), GFP_KERNEL);
74
75 if (!inftl) {
76 printk(KERN_WARNING "INFTL: Out of memory for data structures\n");
77 return;
78 }
79 memset(inftl, 0, sizeof(*inftl));
80
81 inftl->mbd.mtd = mtd;
82 inftl->mbd.devnum = -1;
83 inftl->mbd.blksize = 512;
84 inftl->mbd.tr = tr;
85 memcpy(&inftl->oobinfo, &mtd->oobinfo, sizeof(struct nand_oobinfo));
86 inftl->oobinfo.useecc = MTD_NANDECC_PLACEONLY;
87
88 if (INFTL_mount(inftl) < 0) {
89 printk(KERN_WARNING "INFTL: could not mount device\n");
90 kfree(inftl);
91 return;
92 }
93
94 /* OK, it's a new one. Set up all the data structures. */
95
96 /* Calculate geometry */
97 inftl->cylinders = 1024;
98 inftl->heads = 16;
99
100 temp = inftl->cylinders * inftl->heads;
101 inftl->sectors = inftl->mbd.size / temp;
102 if (inftl->mbd.size % temp) {
103 inftl->sectors++;
104 temp = inftl->cylinders * inftl->sectors;
105 inftl->heads = inftl->mbd.size / temp;
106
107 if (inftl->mbd.size % temp) {
108 inftl->heads++;
109 temp = inftl->heads * inftl->sectors;
110 inftl->cylinders = inftl->mbd.size / temp;
111 }
112 }
113
114 if (inftl->mbd.size != inftl->heads * inftl->cylinders * inftl->sectors) {
115 /*
116 Oh no we don't have
117 mbd.size == heads * cylinders * sectors
118 */
119 printk(KERN_WARNING "INFTL: cannot calculate a geometry to "
120 "match size of 0x%lx.\n", inftl->mbd.size);
121 printk(KERN_WARNING "INFTL: using C:%d H:%d S:%d "
122 "(== 0x%lx sects)\n",
123 inftl->cylinders, inftl->heads , inftl->sectors,
124 (long)inftl->cylinders * (long)inftl->heads *
125 (long)inftl->sectors );
126 }
127
128 if (add_mtd_blktrans_dev(&inftl->mbd)) {
129 if (inftl->PUtable)
130 kfree(inftl->PUtable);
131 if (inftl->VUtable)
132 kfree(inftl->VUtable);
133 kfree(inftl);
134 return;
135 }
136#ifdef PSYCHO_DEBUG
137 printk(KERN_INFO "INFTL: Found new nftl%c\n", nftl->mbd.devnum + 'a');
138#endif
139 return;
140}
141
142static void inftl_remove_dev(struct mtd_blktrans_dev *dev)
143{
144 struct INFTLrecord *inftl = (void *)dev;
145
146 DEBUG(MTD_DEBUG_LEVEL3, "INFTL: remove_dev (i=%d)\n", dev->devnum);
147
148 del_mtd_blktrans_dev(dev);
149
150 if (inftl->PUtable)
151 kfree(inftl->PUtable);
152 if (inftl->VUtable)
153 kfree(inftl->VUtable);
154 kfree(inftl);
155}
156
157/*
158 * Actual INFTL access routines.
159 */
160
161/*
162 * INFTL_findfreeblock: Find a free Erase Unit on the INFTL partition.
163 * This function is used when the give Virtual Unit Chain.
164 */
165static u16 INFTL_findfreeblock(struct INFTLrecord *inftl, int desperate)
166{
167 u16 pot = inftl->LastFreeEUN;
168 int silly = inftl->nb_blocks;
169
170 DEBUG(MTD_DEBUG_LEVEL3, "INFTL: INFTL_findfreeblock(inftl=%p,"
171 "desperate=%d)\n", inftl, desperate);
172
173 /*
174 * Normally, we force a fold to happen before we run out of free
175 * blocks completely.
176 */
177 if (!desperate && inftl->numfreeEUNs < 2) {
178 DEBUG(MTD_DEBUG_LEVEL1, "INFTL: there are too few free "
179 "EUNs (%d)\n", inftl->numfreeEUNs);
180 return 0xffff;
181 }
182
183 /* Scan for a free block */
184 do {
185 if (inftl->PUtable[pot] == BLOCK_FREE) {
186 inftl->LastFreeEUN = pot;
187 return pot;
188 }
189
190 if (++pot > inftl->lastEUN)
191 pot = 0;
192
193 if (!silly--) {
194 printk(KERN_WARNING "INFTL: no free blocks found! "
195 "EUN range = %d - %d\n", 0, inftl->LastFreeEUN);
196 return BLOCK_NIL;
197 }
198 } while (pot != inftl->LastFreeEUN);
199
200 return BLOCK_NIL;
201}
202
203static u16 INFTL_foldchain(struct INFTLrecord *inftl, unsigned thisVUC, unsigned pendingblock)
204{
205 u16 BlockMap[MAX_SECTORS_PER_UNIT];
206 unsigned char BlockDeleted[MAX_SECTORS_PER_UNIT];
207 unsigned int thisEUN, prevEUN, status;
208 int block, silly;
209 unsigned int targetEUN;
210 struct inftl_oob oob;
211 size_t retlen;
212
213 DEBUG(MTD_DEBUG_LEVEL3, "INFTL: INFTL_foldchain(inftl=%p,thisVUC=%d,"
214 "pending=%d)\n", inftl, thisVUC, pendingblock);
215
216 memset(BlockMap, 0xff, sizeof(BlockMap));
217 memset(BlockDeleted, 0, sizeof(BlockDeleted));
218
219 thisEUN = targetEUN = inftl->VUtable[thisVUC];
220
221 if (thisEUN == BLOCK_NIL) {
222 printk(KERN_WARNING "INFTL: trying to fold non-existent "
223 "Virtual Unit Chain %d!\n", thisVUC);
224 return BLOCK_NIL;
225 }
226
227 /*
228 * Scan to find the Erase Unit which holds the actual data for each
229 * 512-byte block within the Chain.
230 */
231 silly = MAX_LOOPS;
232 while (thisEUN < inftl->nb_blocks) {
233 for (block = 0; block < inftl->EraseSize/SECTORSIZE; block ++) {
234 if ((BlockMap[block] != 0xffff) || BlockDeleted[block])
235 continue;
236
237 if (MTD_READOOB(inftl->mbd.mtd, (thisEUN * inftl->EraseSize)
238 + (block * SECTORSIZE), 16 , &retlen,
239 (char *)&oob) < 0)
240 status = SECTOR_IGNORE;
241 else
242 status = oob.b.Status | oob.b.Status1;
243
244 switch(status) {
245 case SECTOR_FREE:
246 case SECTOR_IGNORE:
247 break;
248 case SECTOR_USED:
249 BlockMap[block] = thisEUN;
250 continue;
251 case SECTOR_DELETED:
252 BlockDeleted[block] = 1;
253 continue;
254 default:
255 printk(KERN_WARNING "INFTL: unknown status "
256 "for block %d in EUN %d: %x\n",
257 block, thisEUN, status);
258 break;
259 }
260 }
261
262 if (!silly--) {
263 printk(KERN_WARNING "INFTL: infinite loop in Virtual "
264 "Unit Chain 0x%x\n", thisVUC);
265 return BLOCK_NIL;
266 }
267
268 thisEUN = inftl->PUtable[thisEUN];
269 }
270
271 /*
272 * OK. We now know the location of every block in the Virtual Unit
273 * Chain, and the Erase Unit into which we are supposed to be copying.
274 * Go for it.
275 */
276 DEBUG(MTD_DEBUG_LEVEL1, "INFTL: folding chain %d into unit %d\n",
277 thisVUC, targetEUN);
278
279 for (block = 0; block < inftl->EraseSize/SECTORSIZE ; block++) {
280 unsigned char movebuf[SECTORSIZE];
281 int ret;
282
283 /*
284 * If it's in the target EUN already, or if it's pending write,
285 * do nothing.
286 */
287 if (BlockMap[block] == targetEUN || (pendingblock ==
288 (thisVUC * (inftl->EraseSize / SECTORSIZE) + block))) {
289 continue;
290 }
291
292 /*
293 * Copy only in non free block (free blocks can only
294 * happen in case of media errors or deleted blocks).
295 */
296 if (BlockMap[block] == BLOCK_NIL)
297 continue;
298
299 ret = MTD_READ(inftl->mbd.mtd, (inftl->EraseSize *
300 BlockMap[block]) + (block * SECTORSIZE), SECTORSIZE,
301 &retlen, movebuf);
302 if (ret < 0) {
303 ret = MTD_READ(inftl->mbd.mtd, (inftl->EraseSize *
304 BlockMap[block]) + (block * SECTORSIZE),
305 SECTORSIZE, &retlen, movebuf);
306 if (ret != -EIO)
307 DEBUG(MTD_DEBUG_LEVEL1, "INFTL: error went "
308 "away on retry?\n");
309 }
310 memset(&oob, 0xff, sizeof(struct inftl_oob));
311 oob.b.Status = oob.b.Status1 = SECTOR_USED;
312 MTD_WRITEECC(inftl->mbd.mtd, (inftl->EraseSize * targetEUN) +
313 (block * SECTORSIZE), SECTORSIZE, &retlen,
314 movebuf, (char *)&oob, &inftl->oobinfo);
315 }
316
317 /*
318 * Newest unit in chain now contains data from _all_ older units.
319 * So go through and erase each unit in chain, oldest first. (This
320 * is important, by doing oldest first if we crash/reboot then it
321 * it is relatively simple to clean up the mess).
322 */
323 DEBUG(MTD_DEBUG_LEVEL1, "INFTL: want to erase virtual chain %d\n",
324 thisVUC);
325
326 for (;;) {
327 /* Find oldest unit in chain. */
328 thisEUN = inftl->VUtable[thisVUC];
329 prevEUN = BLOCK_NIL;
330 while (inftl->PUtable[thisEUN] != BLOCK_NIL) {
331 prevEUN = thisEUN;
332 thisEUN = inftl->PUtable[thisEUN];
333 }
334
335 /* Check if we are all done */
336 if (thisEUN == targetEUN)
337 break;
338
339 if (INFTL_formatblock(inftl, thisEUN) < 0) {
340 /*
341 * Could not erase : mark block as reserved.
342 */
343 inftl->PUtable[thisEUN] = BLOCK_RESERVED;
344 } else {
345 /* Correctly erased : mark it as free */
346 inftl->PUtable[thisEUN] = BLOCK_FREE;
347 inftl->PUtable[prevEUN] = BLOCK_NIL;
348 inftl->numfreeEUNs++;
349 }
350 }
351
352 return targetEUN;
353}
354
355static u16 INFTL_makefreeblock(struct INFTLrecord *inftl, unsigned pendingblock)
356{
357 /*
358 * This is the part that needs some cleverness applied.
359 * For now, I'm doing the minimum applicable to actually
360 * get the thing to work.
361 * Wear-levelling and other clever stuff needs to be implemented
362 * and we also need to do some assessment of the results when
363 * the system loses power half-way through the routine.
364 */
365 u16 LongestChain = 0;
366 u16 ChainLength = 0, thislen;
367 u16 chain, EUN;
368
369 DEBUG(MTD_DEBUG_LEVEL3, "INFTL: INFTL_makefreeblock(inftl=%p,"
370 "pending=%d)\n", inftl, pendingblock);
371
372 for (chain = 0; chain < inftl->nb_blocks; chain++) {
373 EUN = inftl->VUtable[chain];
374 thislen = 0;
375
376 while (EUN <= inftl->lastEUN) {
377 thislen++;
378 EUN = inftl->PUtable[EUN];
379 if (thislen > 0xff00) {
380 printk(KERN_WARNING "INFTL: endless loop in "
381 "Virtual Chain %d: Unit %x\n",
382 chain, EUN);
383 /*
384 * Actually, don't return failure.
385 * Just ignore this chain and get on with it.
386 */
387 thislen = 0;
388 break;
389 }
390 }
391
392 if (thislen > ChainLength) {
393 ChainLength = thislen;
394 LongestChain = chain;
395 }
396 }
397
398 if (ChainLength < 2) {
399 printk(KERN_WARNING "INFTL: no Virtual Unit Chains available "
400 "for folding. Failing request\n");
401 return BLOCK_NIL;
402 }
403
404 return INFTL_foldchain(inftl, LongestChain, pendingblock);
405}
406
407static int nrbits(unsigned int val, int bitcount)
408{
409 int i, total = 0;
410
411 for (i = 0; (i < bitcount); i++)
412 total += (((0x1 << i) & val) ? 1 : 0);
413 return total;
414}
415
416/*
417 * INFTL_findwriteunit: Return the unit number into which we can write
418 * for this block. Make it available if it isn't already.
419 */
420static inline u16 INFTL_findwriteunit(struct INFTLrecord *inftl, unsigned block)
421{
422 unsigned int thisVUC = block / (inftl->EraseSize / SECTORSIZE);
423 unsigned int thisEUN, writeEUN, prev_block, status;
424 unsigned long blockofs = (block * SECTORSIZE) & (inftl->EraseSize -1);
425 struct inftl_oob oob;
426 struct inftl_bci bci;
427 unsigned char anac, nacs, parity;
428 size_t retlen;
429 int silly, silly2 = 3;
430
431 DEBUG(MTD_DEBUG_LEVEL3, "INFTL: INFTL_findwriteunit(inftl=%p,"
432 "block=%d)\n", inftl, block);
433
434 do {
435 /*
436 * Scan the media to find a unit in the VUC which has
437 * a free space for the block in question.
438 */
439 writeEUN = BLOCK_NIL;
440 thisEUN = inftl->VUtable[thisVUC];
441 silly = MAX_LOOPS;
442
443 while (thisEUN <= inftl->lastEUN) {
444 MTD_READOOB(inftl->mbd.mtd, (thisEUN * inftl->EraseSize) +
445 blockofs, 8, &retlen, (char *)&bci);
446
447 status = bci.Status | bci.Status1;
448 DEBUG(MTD_DEBUG_LEVEL3, "INFTL: status of block %d in "
449 "EUN %d is %x\n", block , writeEUN, status);
450
451 switch(status) {
452 case SECTOR_FREE:
453 writeEUN = thisEUN;
454 break;
455 case SECTOR_DELETED:
456 case SECTOR_USED:
457 /* Can't go any further */
458 goto hitused;
459 case SECTOR_IGNORE:
460 break;
461 default:
462 /*
463 * Invalid block. Don't use it any more.
464 * Must implement.
465 */
466 break;
467 }
468
469 if (!silly--) {
470 printk(KERN_WARNING "INFTL: infinite loop in "
471 "Virtual Unit Chain 0x%x\n", thisVUC);
472 return 0xffff;
473 }
474
475 /* Skip to next block in chain */
476 thisEUN = inftl->PUtable[thisEUN];
477 }
478
479hitused:
480 if (writeEUN != BLOCK_NIL)
481 return writeEUN;
482
483
484 /*
485 * OK. We didn't find one in the existing chain, or there
486 * is no existing chain. Allocate a new one.
487 */
488 writeEUN = INFTL_findfreeblock(inftl, 0);
489
490 if (writeEUN == BLOCK_NIL) {
491 /*
492 * That didn't work - there were no free blocks just
493 * waiting to be picked up. We're going to have to fold
494 * a chain to make room.
495 */
496 thisEUN = INFTL_makefreeblock(inftl, 0xffff);
497
498 /*
499 * Hopefully we free something, lets try again.
500 * This time we are desperate...
501 */
502 DEBUG(MTD_DEBUG_LEVEL1, "INFTL: using desperate==1 "
503 "to find free EUN to accommodate write to "
504 "VUC %d\n", thisVUC);
505 writeEUN = INFTL_findfreeblock(inftl, 1);
506 if (writeEUN == BLOCK_NIL) {
507 /*
508 * Ouch. This should never happen - we should
509 * always be able to make some room somehow.
510 * If we get here, we've allocated more storage
511 * space than actual media, or our makefreeblock
512 * routine is missing something.
513 */
514 printk(KERN_WARNING "INFTL: cannot make free "
515 "space.\n");
516#ifdef DEBUG
517 INFTL_dumptables(inftl);
518 INFTL_dumpVUchains(inftl);
519#endif
520 return BLOCK_NIL;
521 }
522 }
523
524 /*
525 * Insert new block into virtual chain. Firstly update the
526 * block headers in flash...
527 */
528 anac = 0;
529 nacs = 0;
530 thisEUN = inftl->VUtable[thisVUC];
531 if (thisEUN != BLOCK_NIL) {
532 MTD_READOOB(inftl->mbd.mtd, thisEUN * inftl->EraseSize
533 + 8, 8, &retlen, (char *)&oob.u);
534 anac = oob.u.a.ANAC + 1;
535 nacs = oob.u.a.NACs + 1;
536 }
537
538 prev_block = inftl->VUtable[thisVUC];
539 if (prev_block < inftl->nb_blocks)
540 prev_block -= inftl->firstEUN;
541
542 parity = (nrbits(thisVUC, 16) & 0x1) ? 0x1 : 0;
543 parity |= (nrbits(prev_block, 16) & 0x1) ? 0x2 : 0;
544 parity |= (nrbits(anac, 8) & 0x1) ? 0x4 : 0;
545 parity |= (nrbits(nacs, 8) & 0x1) ? 0x8 : 0;
546
547 oob.u.a.virtualUnitNo = cpu_to_le16(thisVUC);
548 oob.u.a.prevUnitNo = cpu_to_le16(prev_block);
549 oob.u.a.ANAC = anac;
550 oob.u.a.NACs = nacs;
551 oob.u.a.parityPerField = parity;
552 oob.u.a.discarded = 0xaa;
553
554 MTD_WRITEOOB(inftl->mbd.mtd, writeEUN * inftl->EraseSize + 8, 8,
555 &retlen, (char *)&oob.u);
556
557 /* Also back up header... */
558 oob.u.b.virtualUnitNo = cpu_to_le16(thisVUC);
559 oob.u.b.prevUnitNo = cpu_to_le16(prev_block);
560 oob.u.b.ANAC = anac;
561 oob.u.b.NACs = nacs;
562 oob.u.b.parityPerField = parity;
563 oob.u.b.discarded = 0xaa;
564
565 MTD_WRITEOOB(inftl->mbd.mtd, writeEUN * inftl->EraseSize +
566 SECTORSIZE * 4 + 8, 8, &retlen, (char *)&oob.u);
567
568 inftl->PUtable[writeEUN] = inftl->VUtable[thisVUC];
569 inftl->VUtable[thisVUC] = writeEUN;
570
571 inftl->numfreeEUNs--;
572 return writeEUN;
573
574 } while (silly2--);
575
576 printk(KERN_WARNING "INFTL: error folding to make room for Virtual "
577 "Unit Chain 0x%x\n", thisVUC);
578 return 0xffff;
579}
580
581/*
582 * Given a Virtual Unit Chain, see if it can be deleted, and if so do it.
583 */
584static void INFTL_trydeletechain(struct INFTLrecord *inftl, unsigned thisVUC)
585{
586 unsigned char BlockUsed[MAX_SECTORS_PER_UNIT];
587 unsigned char BlockDeleted[MAX_SECTORS_PER_UNIT];
588 unsigned int thisEUN, status;
589 int block, silly;
590 struct inftl_bci bci;
591 size_t retlen;
592
593 DEBUG(MTD_DEBUG_LEVEL3, "INFTL: INFTL_trydeletechain(inftl=%p,"
594 "thisVUC=%d)\n", inftl, thisVUC);
595
596 memset(BlockUsed, 0, sizeof(BlockUsed));
597 memset(BlockDeleted, 0, sizeof(BlockDeleted));
598
599 thisEUN = inftl->VUtable[thisVUC];
600 if (thisEUN == BLOCK_NIL) {
601 printk(KERN_WARNING "INFTL: trying to delete non-existent "
602 "Virtual Unit Chain %d!\n", thisVUC);
603 return;
604 }
605
606 /*
607 * Scan through the Erase Units to determine whether any data is in
608 * each of the 512-byte blocks within the Chain.
609 */
610 silly = MAX_LOOPS;
611 while (thisEUN < inftl->nb_blocks) {
612 for (block = 0; block < inftl->EraseSize/SECTORSIZE; block++) {
613 if (BlockUsed[block] || BlockDeleted[block])
614 continue;
615
616 if (MTD_READOOB(inftl->mbd.mtd, (thisEUN * inftl->EraseSize)
617 + (block * SECTORSIZE), 8 , &retlen,
618 (char *)&bci) < 0)
619 status = SECTOR_IGNORE;
620 else
621 status = bci.Status | bci.Status1;
622
623 switch(status) {
624 case SECTOR_FREE:
625 case SECTOR_IGNORE:
626 break;
627 case SECTOR_USED:
628 BlockUsed[block] = 1;
629 continue;
630 case SECTOR_DELETED:
631 BlockDeleted[block] = 1;
632 continue;
633 default:
634 printk(KERN_WARNING "INFTL: unknown status "
635 "for block %d in EUN %d: 0x%x\n",
636 block, thisEUN, status);
637 }
638 }
639
640 if (!silly--) {
641 printk(KERN_WARNING "INFTL: infinite loop in Virtual "
642 "Unit Chain 0x%x\n", thisVUC);
643 return;
644 }
645
646 thisEUN = inftl->PUtable[thisEUN];
647 }
648
649 for (block = 0; block < inftl->EraseSize/SECTORSIZE; block++)
650 if (BlockUsed[block])
651 return;
652
653 /*
654 * For each block in the chain free it and make it available
655 * for future use. Erase from the oldest unit first.
656 */
657 DEBUG(MTD_DEBUG_LEVEL1, "INFTL: deleting empty VUC %d\n", thisVUC);
658
659 for (;;) {
660 u16 *prevEUN = &inftl->VUtable[thisVUC];
661 thisEUN = *prevEUN;
662
663 /* If the chain is all gone already, we're done */
664 if (thisEUN == BLOCK_NIL) {
665 DEBUG(MTD_DEBUG_LEVEL2, "INFTL: Empty VUC %d for deletion was already absent\n", thisEUN);
666 return;
667 }
668
669 /* Find oldest unit in chain. */
670 while (inftl->PUtable[thisEUN] != BLOCK_NIL) {
671 BUG_ON(thisEUN >= inftl->nb_blocks);
672
673 prevEUN = &inftl->PUtable[thisEUN];
674 thisEUN = *prevEUN;
675 }
676
677 DEBUG(MTD_DEBUG_LEVEL3, "Deleting EUN %d from VUC %d\n",
678 thisEUN, thisVUC);
679
680 if (INFTL_formatblock(inftl, thisEUN) < 0) {
681 /*
682 * Could not erase : mark block as reserved.
683 */
684 inftl->PUtable[thisEUN] = BLOCK_RESERVED;
685 } else {
686 /* Correctly erased : mark it as free */
687 inftl->PUtable[thisEUN] = BLOCK_FREE;
688 inftl->numfreeEUNs++;
689 }
690
691 /* Now sort out whatever was pointing to it... */
692 *prevEUN = BLOCK_NIL;
693
694 /* Ideally we'd actually be responsive to new
695 requests while we're doing this -- if there's
696 free space why should others be made to wait? */
697 cond_resched();
698 }
699
700 inftl->VUtable[thisVUC] = BLOCK_NIL;
701}
702
703static int INFTL_deleteblock(struct INFTLrecord *inftl, unsigned block)
704{
705 unsigned int thisEUN = inftl->VUtable[block / (inftl->EraseSize / SECTORSIZE)];
706 unsigned long blockofs = (block * SECTORSIZE) & (inftl->EraseSize - 1);
707 unsigned int status;
708 int silly = MAX_LOOPS;
709 size_t retlen;
710 struct inftl_bci bci;
711
712 DEBUG(MTD_DEBUG_LEVEL3, "INFTL: INFTL_deleteblock(inftl=%p,"
713 "block=%d)\n", inftl, block);
714
715 while (thisEUN < inftl->nb_blocks) {
716 if (MTD_READOOB(inftl->mbd.mtd, (thisEUN * inftl->EraseSize) +
717 blockofs, 8, &retlen, (char *)&bci) < 0)
718 status = SECTOR_IGNORE;
719 else
720 status = bci.Status | bci.Status1;
721
722 switch (status) {
723 case SECTOR_FREE:
724 case SECTOR_IGNORE:
725 break;
726 case SECTOR_DELETED:
727 thisEUN = BLOCK_NIL;
728 goto foundit;
729 case SECTOR_USED:
730 goto foundit;
731 default:
732 printk(KERN_WARNING "INFTL: unknown status for "
733 "block %d in EUN %d: 0x%x\n",
734 block, thisEUN, status);
735 break;
736 }
737
738 if (!silly--) {
739 printk(KERN_WARNING "INFTL: infinite loop in Virtual "
740 "Unit Chain 0x%x\n",
741 block / (inftl->EraseSize / SECTORSIZE));
742 return 1;
743 }
744 thisEUN = inftl->PUtable[thisEUN];
745 }
746
747foundit:
748 if (thisEUN != BLOCK_NIL) {
749 loff_t ptr = (thisEUN * inftl->EraseSize) + blockofs;
750
751 if (MTD_READOOB(inftl->mbd.mtd, ptr, 8, &retlen, (char *)&bci) < 0)
752 return -EIO;
753 bci.Status = bci.Status1 = SECTOR_DELETED;
754 if (MTD_WRITEOOB(inftl->mbd.mtd, ptr, 8, &retlen, (char *)&bci) < 0)
755 return -EIO;
756 INFTL_trydeletechain(inftl, block / (inftl->EraseSize / SECTORSIZE));
757 }
758 return 0;
759}
760
761static int inftl_writeblock(struct mtd_blktrans_dev *mbd, unsigned long block,
762 char *buffer)
763{
764 struct INFTLrecord *inftl = (void *)mbd;
765 unsigned int writeEUN;
766 unsigned long blockofs = (block * SECTORSIZE) & (inftl->EraseSize - 1);
767 size_t retlen;
768 struct inftl_oob oob;
769 char *p, *pend;
770
771 DEBUG(MTD_DEBUG_LEVEL3, "INFTL: inftl_writeblock(inftl=%p,block=%ld,"
772 "buffer=%p)\n", inftl, block, buffer);
773
774 /* Is block all zero? */
775 pend = buffer + SECTORSIZE;
776 for (p = buffer; p < pend && !*p; p++)
777 ;
778
779 if (p < pend) {
780 writeEUN = INFTL_findwriteunit(inftl, block);
781
782 if (writeEUN == BLOCK_NIL) {
783 printk(KERN_WARNING "inftl_writeblock(): cannot find "
784 "block to write to\n");
785 /*
786 * If we _still_ haven't got a block to use,
787 * we're screwed.
788 */
789 return 1;
790 }
791
792 memset(&oob, 0xff, sizeof(struct inftl_oob));
793 oob.b.Status = oob.b.Status1 = SECTOR_USED;
794 MTD_WRITEECC(inftl->mbd.mtd, (writeEUN * inftl->EraseSize) +
795 blockofs, SECTORSIZE, &retlen, (char *)buffer,
796 (char *)&oob, &inftl->oobinfo);
797 /*
798 * need to write SECTOR_USED flags since they are not written
799 * in mtd_writeecc
800 */
801 } else {
802 INFTL_deleteblock(inftl, block);
803 }
804
805 return 0;
806}
807
808static int inftl_readblock(struct mtd_blktrans_dev *mbd, unsigned long block,
809 char *buffer)
810{
811 struct INFTLrecord *inftl = (void *)mbd;
812 unsigned int thisEUN = inftl->VUtable[block / (inftl->EraseSize / SECTORSIZE)];
813 unsigned long blockofs = (block * SECTORSIZE) & (inftl->EraseSize - 1);
814 unsigned int status;
815 int silly = MAX_LOOPS;
816 struct inftl_bci bci;
817 size_t retlen;
818
819 DEBUG(MTD_DEBUG_LEVEL3, "INFTL: inftl_readblock(inftl=%p,block=%ld,"
820 "buffer=%p)\n", inftl, block, buffer);
821
822 while (thisEUN < inftl->nb_blocks) {
823 if (MTD_READOOB(inftl->mbd.mtd, (thisEUN * inftl->EraseSize) +
824 blockofs, 8, &retlen, (char *)&bci) < 0)
825 status = SECTOR_IGNORE;
826 else
827 status = bci.Status | bci.Status1;
828
829 switch (status) {
830 case SECTOR_DELETED:
831 thisEUN = BLOCK_NIL;
832 goto foundit;
833 case SECTOR_USED:
834 goto foundit;
835 case SECTOR_FREE:
836 case SECTOR_IGNORE:
837 break;
838 default:
839 printk(KERN_WARNING "INFTL: unknown status for "
840 "block %ld in EUN %d: 0x%04x\n",
841 block, thisEUN, status);
842 break;
843 }
844
845 if (!silly--) {
846 printk(KERN_WARNING "INFTL: infinite loop in "
847 "Virtual Unit Chain 0x%lx\n",
848 block / (inftl->EraseSize / SECTORSIZE));
849 return 1;
850 }
851
852 thisEUN = inftl->PUtable[thisEUN];
853 }
854
855foundit:
856 if (thisEUN == BLOCK_NIL) {
857 /* The requested block is not on the media, return all 0x00 */
858 memset(buffer, 0, SECTORSIZE);
859 } else {
860 size_t retlen;
861 loff_t ptr = (thisEUN * inftl->EraseSize) + blockofs;
862 if (MTD_READ(inftl->mbd.mtd, ptr, SECTORSIZE, &retlen,
863 buffer))
864 return -EIO;
865 }
866 return 0;
867}
868
869static int inftl_getgeo(struct mtd_blktrans_dev *dev, struct hd_geometry *geo)
870{
871 struct INFTLrecord *inftl = (void *)dev;
872
873 geo->heads = inftl->heads;
874 geo->sectors = inftl->sectors;
875 geo->cylinders = inftl->cylinders;
876
877 return 0;
878}
879
880static struct mtd_blktrans_ops inftl_tr = {
881 .name = "inftl",
882 .major = INFTL_MAJOR,
883 .part_bits = INFTL_PARTN_BITS,
884 .getgeo = inftl_getgeo,
885 .readsect = inftl_readblock,
886 .writesect = inftl_writeblock,
887 .add_mtd = inftl_add_mtd,
888 .remove_dev = inftl_remove_dev,
889 .owner = THIS_MODULE,
890};
891
892extern char inftlmountrev[];
893
894static int __init init_inftl(void)
895{
896 printk(KERN_INFO "INFTL: inftlcore.c $Revision: 1.18 $, "
897 "inftlmount.c %s\n", inftlmountrev);
898
899 return register_mtd_blktrans(&inftl_tr);
900}
901
902static void __exit cleanup_inftl(void)
903{
904 deregister_mtd_blktrans(&inftl_tr);
905}
906
907module_init(init_inftl);
908module_exit(cleanup_inftl);
909
910MODULE_LICENSE("GPL");
911MODULE_AUTHOR("Greg Ungerer <gerg@snapgear.com>, David Woodhouse <dwmw2@infradead.org>, Fabrice Bellard <fabrice.bellard@netgem.com> et al.");
912MODULE_DESCRIPTION("Support code for Inverse Flash Translation Layer, used on M-Systems DiskOnChip 2000, Millennium and Millennium Plus");