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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * inftlcore.c -- Linux driver for Inverse Flash Translation Layer (INFTL)
4 *
5 * Copyright © 2002, Greg Ungerer (gerg@snapgear.com)
6 *
7 * Based heavily on the nftlcore.c code which is:
8 * Copyright © 1999 Machine Vision Holdings, Inc.
9 * Copyright © 1999 David Woodhouse <dwmw2@infradead.org>
10 */
11
12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <linux/delay.h>
15#include <linux/slab.h>
16#include <linux/sched.h>
17#include <linux/init.h>
18#include <linux/kmod.h>
19#include <linux/hdreg.h>
20#include <linux/mtd/mtd.h>
21#include <linux/mtd/nftl.h>
22#include <linux/mtd/inftl.h>
23#include <linux/mtd/rawnand.h>
24#include <linux/uaccess.h>
25#include <asm/errno.h>
26#include <asm/io.h>
27
28/*
29 * Maximum number of loops while examining next block, to have a
30 * chance to detect consistency problems (they should never happen
31 * because of the checks done in the mounting.
32 */
33#define MAX_LOOPS 10000
34
35static void inftl_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
36{
37 struct INFTLrecord *inftl;
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 if (!mtd->_block_isbad) {
47 printk(KERN_ERR
48"INFTL no longer supports the old DiskOnChip drivers loaded via docprobe.\n"
49"Please use the new diskonchip driver under the NAND subsystem.\n");
50 return;
51 }
52
53 pr_debug("INFTL: add_mtd for %s\n", mtd->name);
54
55 inftl = kzalloc(sizeof(*inftl), GFP_KERNEL);
56
57 if (!inftl)
58 return;
59
60 inftl->mbd.mtd = mtd;
61 inftl->mbd.devnum = -1;
62
63 inftl->mbd.tr = tr;
64
65 if (INFTL_mount(inftl) < 0) {
66 printk(KERN_WARNING "INFTL: could not mount device\n");
67 kfree(inftl);
68 return;
69 }
70
71 /* OK, it's a new one. Set up all the data structures. */
72
73 /* Calculate geometry */
74 inftl->cylinders = 1024;
75 inftl->heads = 16;
76
77 temp = inftl->cylinders * inftl->heads;
78 inftl->sectors = inftl->mbd.size / temp;
79 if (inftl->mbd.size % temp) {
80 inftl->sectors++;
81 temp = inftl->cylinders * inftl->sectors;
82 inftl->heads = inftl->mbd.size / temp;
83
84 if (inftl->mbd.size % temp) {
85 inftl->heads++;
86 temp = inftl->heads * inftl->sectors;
87 inftl->cylinders = inftl->mbd.size / temp;
88 }
89 }
90
91 if (inftl->mbd.size != inftl->heads * inftl->cylinders * inftl->sectors) {
92 /*
93 Oh no we don't have
94 mbd.size == heads * cylinders * sectors
95 */
96 printk(KERN_WARNING "INFTL: cannot calculate a geometry to "
97 "match size of 0x%lx.\n", inftl->mbd.size);
98 printk(KERN_WARNING "INFTL: using C:%d H:%d S:%d "
99 "(== 0x%lx sects)\n",
100 inftl->cylinders, inftl->heads , inftl->sectors,
101 (long)inftl->cylinders * (long)inftl->heads *
102 (long)inftl->sectors );
103 }
104
105 if (add_mtd_blktrans_dev(&inftl->mbd)) {
106 kfree(inftl->PUtable);
107 kfree(inftl->VUtable);
108 kfree(inftl);
109 return;
110 }
111#ifdef PSYCHO_DEBUG
112 printk(KERN_INFO "INFTL: Found new inftl%c\n", inftl->mbd.devnum + 'a');
113#endif
114 return;
115}
116
117static void inftl_remove_dev(struct mtd_blktrans_dev *dev)
118{
119 struct INFTLrecord *inftl = (void *)dev;
120
121 pr_debug("INFTL: remove_dev (i=%d)\n", dev->devnum);
122
123 del_mtd_blktrans_dev(dev);
124
125 kfree(inftl->PUtable);
126 kfree(inftl->VUtable);
127}
128
129/*
130 * Actual INFTL access routines.
131 */
132
133/*
134 * Read oob data from flash
135 */
136int inftl_read_oob(struct mtd_info *mtd, loff_t offs, size_t len,
137 size_t *retlen, uint8_t *buf)
138{
139 struct mtd_oob_ops ops = { };
140 int res;
141
142 ops.mode = MTD_OPS_PLACE_OOB;
143 ops.ooboffs = offs & (mtd->writesize - 1);
144 ops.ooblen = len;
145 ops.oobbuf = buf;
146 ops.datbuf = NULL;
147
148 res = mtd_read_oob(mtd, offs & ~(mtd->writesize - 1), &ops);
149 *retlen = ops.oobretlen;
150 return res;
151}
152
153/*
154 * Write oob data to flash
155 */
156int inftl_write_oob(struct mtd_info *mtd, loff_t offs, size_t len,
157 size_t *retlen, uint8_t *buf)
158{
159 struct mtd_oob_ops ops = { };
160 int res;
161
162 ops.mode = MTD_OPS_PLACE_OOB;
163 ops.ooboffs = offs & (mtd->writesize - 1);
164 ops.ooblen = len;
165 ops.oobbuf = buf;
166 ops.datbuf = NULL;
167
168 res = mtd_write_oob(mtd, offs & ~(mtd->writesize - 1), &ops);
169 *retlen = ops.oobretlen;
170 return res;
171}
172
173/*
174 * Write data and oob to flash
175 */
176static int inftl_write(struct mtd_info *mtd, loff_t offs, size_t len,
177 size_t *retlen, uint8_t *buf, uint8_t *oob)
178{
179 struct mtd_oob_ops ops = { };
180 int res;
181
182 ops.mode = MTD_OPS_PLACE_OOB;
183 ops.ooboffs = offs;
184 ops.ooblen = mtd->oobsize;
185 ops.oobbuf = oob;
186 ops.datbuf = buf;
187 ops.len = len;
188
189 res = mtd_write_oob(mtd, offs & ~(mtd->writesize - 1), &ops);
190 *retlen = ops.retlen;
191 return res;
192}
193
194/*
195 * INFTL_findfreeblock: Find a free Erase Unit on the INFTL partition.
196 * This function is used when the give Virtual Unit Chain.
197 */
198static u16 INFTL_findfreeblock(struct INFTLrecord *inftl, int desperate)
199{
200 u16 pot = inftl->LastFreeEUN;
201 int silly = inftl->nb_blocks;
202
203 pr_debug("INFTL: INFTL_findfreeblock(inftl=%p,desperate=%d)\n",
204 inftl, desperate);
205
206 /*
207 * Normally, we force a fold to happen before we run out of free
208 * blocks completely.
209 */
210 if (!desperate && inftl->numfreeEUNs < 2) {
211 pr_debug("INFTL: there are too few free EUNs (%d)\n",
212 inftl->numfreeEUNs);
213 return BLOCK_NIL;
214 }
215
216 /* Scan for a free block */
217 do {
218 if (inftl->PUtable[pot] == BLOCK_FREE) {
219 inftl->LastFreeEUN = pot;
220 return pot;
221 }
222
223 if (++pot > inftl->lastEUN)
224 pot = 0;
225
226 if (!silly--) {
227 printk(KERN_WARNING "INFTL: no free blocks found! "
228 "EUN range = %d - %d\n", 0, inftl->LastFreeEUN);
229 return BLOCK_NIL;
230 }
231 } while (pot != inftl->LastFreeEUN);
232
233 return BLOCK_NIL;
234}
235
236static u16 INFTL_foldchain(struct INFTLrecord *inftl, unsigned thisVUC, unsigned pendingblock)
237{
238 u16 BlockMap[MAX_SECTORS_PER_UNIT];
239 unsigned char BlockDeleted[MAX_SECTORS_PER_UNIT];
240 unsigned int thisEUN, prevEUN, status;
241 struct mtd_info *mtd = inftl->mbd.mtd;
242 int block, silly;
243 unsigned int targetEUN;
244 struct inftl_oob oob;
245 size_t retlen;
246
247 pr_debug("INFTL: INFTL_foldchain(inftl=%p,thisVUC=%d,pending=%d)\n",
248 inftl, thisVUC, pendingblock);
249
250 memset(BlockMap, 0xff, sizeof(BlockMap));
251 memset(BlockDeleted, 0, sizeof(BlockDeleted));
252
253 thisEUN = targetEUN = inftl->VUtable[thisVUC];
254
255 if (thisEUN == BLOCK_NIL) {
256 printk(KERN_WARNING "INFTL: trying to fold non-existent "
257 "Virtual Unit Chain %d!\n", thisVUC);
258 return BLOCK_NIL;
259 }
260
261 /*
262 * Scan to find the Erase Unit which holds the actual data for each
263 * 512-byte block within the Chain.
264 */
265 silly = MAX_LOOPS;
266 while (thisEUN < inftl->nb_blocks) {
267 for (block = 0; block < inftl->EraseSize/SECTORSIZE; block ++) {
268 if ((BlockMap[block] != BLOCK_NIL) ||
269 BlockDeleted[block])
270 continue;
271
272 if (inftl_read_oob(mtd, (thisEUN * inftl->EraseSize)
273 + (block * SECTORSIZE), 16, &retlen,
274 (char *)&oob) < 0)
275 status = SECTOR_IGNORE;
276 else
277 status = oob.b.Status | oob.b.Status1;
278
279 switch(status) {
280 case SECTOR_FREE:
281 case SECTOR_IGNORE:
282 break;
283 case SECTOR_USED:
284 BlockMap[block] = thisEUN;
285 continue;
286 case SECTOR_DELETED:
287 BlockDeleted[block] = 1;
288 continue;
289 default:
290 printk(KERN_WARNING "INFTL: unknown status "
291 "for block %d in EUN %d: %x\n",
292 block, thisEUN, status);
293 break;
294 }
295 }
296
297 if (!silly--) {
298 printk(KERN_WARNING "INFTL: infinite loop in Virtual "
299 "Unit Chain 0x%x\n", thisVUC);
300 return BLOCK_NIL;
301 }
302
303 thisEUN = inftl->PUtable[thisEUN];
304 }
305
306 /*
307 * OK. We now know the location of every block in the Virtual Unit
308 * Chain, and the Erase Unit into which we are supposed to be copying.
309 * Go for it.
310 */
311 pr_debug("INFTL: folding chain %d into unit %d\n", thisVUC, targetEUN);
312
313 for (block = 0; block < inftl->EraseSize/SECTORSIZE ; block++) {
314 unsigned char movebuf[SECTORSIZE];
315 int ret;
316
317 /*
318 * If it's in the target EUN already, or if it's pending write,
319 * do nothing.
320 */
321 if (BlockMap[block] == targetEUN || (pendingblock ==
322 (thisVUC * (inftl->EraseSize / SECTORSIZE) + block))) {
323 continue;
324 }
325
326 /*
327 * Copy only in non free block (free blocks can only
328 * happen in case of media errors or deleted blocks).
329 */
330 if (BlockMap[block] == BLOCK_NIL)
331 continue;
332
333 ret = mtd_read(mtd,
334 (inftl->EraseSize * BlockMap[block]) + (block * SECTORSIZE),
335 SECTORSIZE,
336 &retlen,
337 movebuf);
338 if (ret < 0 && !mtd_is_bitflip(ret)) {
339 ret = mtd_read(mtd,
340 (inftl->EraseSize * BlockMap[block]) + (block * SECTORSIZE),
341 SECTORSIZE,
342 &retlen,
343 movebuf);
344 if (ret != -EIO)
345 pr_debug("INFTL: error went away on retry?\n");
346 }
347 memset(&oob, 0xff, sizeof(struct inftl_oob));
348 oob.b.Status = oob.b.Status1 = SECTOR_USED;
349
350 inftl_write(inftl->mbd.mtd, (inftl->EraseSize * targetEUN) +
351 (block * SECTORSIZE), SECTORSIZE, &retlen,
352 movebuf, (char *)&oob);
353 }
354
355 /*
356 * Newest unit in chain now contains data from _all_ older units.
357 * So go through and erase each unit in chain, oldest first. (This
358 * is important, by doing oldest first if we crash/reboot then it
359 * is relatively simple to clean up the mess).
360 */
361 pr_debug("INFTL: want to erase virtual chain %d\n", thisVUC);
362
363 for (;;) {
364 /* Find oldest unit in chain. */
365 thisEUN = inftl->VUtable[thisVUC];
366 prevEUN = BLOCK_NIL;
367 while (inftl->PUtable[thisEUN] != BLOCK_NIL) {
368 prevEUN = thisEUN;
369 thisEUN = inftl->PUtable[thisEUN];
370 }
371
372 /* Check if we are all done */
373 if (thisEUN == targetEUN)
374 break;
375
376 /* Unlink the last block from the chain. */
377 inftl->PUtable[prevEUN] = BLOCK_NIL;
378
379 /* Now try to erase it. */
380 if (INFTL_formatblock(inftl, thisEUN) < 0) {
381 /*
382 * Could not erase : mark block as reserved.
383 */
384 inftl->PUtable[thisEUN] = BLOCK_RESERVED;
385 } else {
386 /* Correctly erased : mark it as free */
387 inftl->PUtable[thisEUN] = BLOCK_FREE;
388 inftl->numfreeEUNs++;
389 }
390 }
391
392 return targetEUN;
393}
394
395static u16 INFTL_makefreeblock(struct INFTLrecord *inftl, unsigned pendingblock)
396{
397 /*
398 * This is the part that needs some cleverness applied.
399 * For now, I'm doing the minimum applicable to actually
400 * get the thing to work.
401 * Wear-levelling and other clever stuff needs to be implemented
402 * and we also need to do some assessment of the results when
403 * the system loses power half-way through the routine.
404 */
405 u16 LongestChain = 0;
406 u16 ChainLength = 0, thislen;
407 u16 chain, EUN;
408
409 pr_debug("INFTL: INFTL_makefreeblock(inftl=%p,"
410 "pending=%d)\n", inftl, pendingblock);
411
412 for (chain = 0; chain < inftl->nb_blocks; chain++) {
413 EUN = inftl->VUtable[chain];
414 thislen = 0;
415
416 while (EUN <= inftl->lastEUN) {
417 thislen++;
418 EUN = inftl->PUtable[EUN];
419 if (thislen > 0xff00) {
420 printk(KERN_WARNING "INFTL: endless loop in "
421 "Virtual Chain %d: Unit %x\n",
422 chain, EUN);
423 /*
424 * Actually, don't return failure.
425 * Just ignore this chain and get on with it.
426 */
427 thislen = 0;
428 break;
429 }
430 }
431
432 if (thislen > ChainLength) {
433 ChainLength = thislen;
434 LongestChain = chain;
435 }
436 }
437
438 if (ChainLength < 2) {
439 printk(KERN_WARNING "INFTL: no Virtual Unit Chains available "
440 "for folding. Failing request\n");
441 return BLOCK_NIL;
442 }
443
444 return INFTL_foldchain(inftl, LongestChain, pendingblock);
445}
446
447static int nrbits(unsigned int val, int bitcount)
448{
449 int i, total = 0;
450
451 for (i = 0; (i < bitcount); i++)
452 total += (((0x1 << i) & val) ? 1 : 0);
453 return total;
454}
455
456/*
457 * INFTL_findwriteunit: Return the unit number into which we can write
458 * for this block. Make it available if it isn't already.
459 */
460static inline u16 INFTL_findwriteunit(struct INFTLrecord *inftl, unsigned block)
461{
462 unsigned int thisVUC = block / (inftl->EraseSize / SECTORSIZE);
463 unsigned int thisEUN, writeEUN, prev_block, status;
464 unsigned long blockofs = (block * SECTORSIZE) & (inftl->EraseSize -1);
465 struct mtd_info *mtd = inftl->mbd.mtd;
466 struct inftl_oob oob;
467 struct inftl_bci bci;
468 unsigned char anac, nacs, parity;
469 size_t retlen;
470 int silly, silly2 = 3;
471
472 pr_debug("INFTL: INFTL_findwriteunit(inftl=%p,block=%d)\n",
473 inftl, block);
474
475 do {
476 /*
477 * Scan the media to find a unit in the VUC which has
478 * a free space for the block in question.
479 */
480 writeEUN = BLOCK_NIL;
481 thisEUN = inftl->VUtable[thisVUC];
482 silly = MAX_LOOPS;
483
484 while (thisEUN <= inftl->lastEUN) {
485 inftl_read_oob(mtd, (thisEUN * inftl->EraseSize) +
486 blockofs, 8, &retlen, (char *)&bci);
487
488 status = bci.Status | bci.Status1;
489 pr_debug("INFTL: status of block %d in EUN %d is %x\n",
490 block , writeEUN, status);
491
492 switch(status) {
493 case SECTOR_FREE:
494 writeEUN = thisEUN;
495 break;
496 case SECTOR_DELETED:
497 case SECTOR_USED:
498 /* Can't go any further */
499 goto hitused;
500 case SECTOR_IGNORE:
501 break;
502 default:
503 /*
504 * Invalid block. Don't use it any more.
505 * Must implement.
506 */
507 break;
508 }
509
510 if (!silly--) {
511 printk(KERN_WARNING "INFTL: infinite loop in "
512 "Virtual Unit Chain 0x%x\n", thisVUC);
513 return BLOCK_NIL;
514 }
515
516 /* Skip to next block in chain */
517 thisEUN = inftl->PUtable[thisEUN];
518 }
519
520hitused:
521 if (writeEUN != BLOCK_NIL)
522 return writeEUN;
523
524
525 /*
526 * OK. We didn't find one in the existing chain, or there
527 * is no existing chain. Allocate a new one.
528 */
529 writeEUN = INFTL_findfreeblock(inftl, 0);
530
531 if (writeEUN == BLOCK_NIL) {
532 /*
533 * That didn't work - there were no free blocks just
534 * waiting to be picked up. We're going to have to fold
535 * a chain to make room.
536 */
537 thisEUN = INFTL_makefreeblock(inftl, block);
538
539 /*
540 * Hopefully we free something, lets try again.
541 * This time we are desperate...
542 */
543 pr_debug("INFTL: using desperate==1 to find free EUN "
544 "to accommodate write to VUC %d\n",
545 thisVUC);
546 writeEUN = INFTL_findfreeblock(inftl, 1);
547 if (writeEUN == BLOCK_NIL) {
548 /*
549 * Ouch. This should never happen - we should
550 * always be able to make some room somehow.
551 * If we get here, we've allocated more storage
552 * space than actual media, or our makefreeblock
553 * routine is missing something.
554 */
555 printk(KERN_WARNING "INFTL: cannot make free "
556 "space.\n");
557#ifdef DEBUG
558 INFTL_dumptables(inftl);
559 INFTL_dumpVUchains(inftl);
560#endif
561 return BLOCK_NIL;
562 }
563 }
564
565 /*
566 * Insert new block into virtual chain. Firstly update the
567 * block headers in flash...
568 */
569 anac = 0;
570 nacs = 0;
571 thisEUN = inftl->VUtable[thisVUC];
572 if (thisEUN != BLOCK_NIL) {
573 inftl_read_oob(mtd, thisEUN * inftl->EraseSize
574 + 8, 8, &retlen, (char *)&oob.u);
575 anac = oob.u.a.ANAC + 1;
576 nacs = oob.u.a.NACs + 1;
577 }
578
579 prev_block = inftl->VUtable[thisVUC];
580 if (prev_block < inftl->nb_blocks)
581 prev_block -= inftl->firstEUN;
582
583 parity = (nrbits(thisVUC, 16) & 0x1) ? 0x1 : 0;
584 parity |= (nrbits(prev_block, 16) & 0x1) ? 0x2 : 0;
585 parity |= (nrbits(anac, 8) & 0x1) ? 0x4 : 0;
586 parity |= (nrbits(nacs, 8) & 0x1) ? 0x8 : 0;
587
588 oob.u.a.virtualUnitNo = cpu_to_le16(thisVUC);
589 oob.u.a.prevUnitNo = cpu_to_le16(prev_block);
590 oob.u.a.ANAC = anac;
591 oob.u.a.NACs = nacs;
592 oob.u.a.parityPerField = parity;
593 oob.u.a.discarded = 0xaa;
594
595 inftl_write_oob(mtd, writeEUN * inftl->EraseSize + 8, 8,
596 &retlen, (char *)&oob.u);
597
598 /* Also back up header... */
599 oob.u.b.virtualUnitNo = cpu_to_le16(thisVUC);
600 oob.u.b.prevUnitNo = cpu_to_le16(prev_block);
601 oob.u.b.ANAC = anac;
602 oob.u.b.NACs = nacs;
603 oob.u.b.parityPerField = parity;
604 oob.u.b.discarded = 0xaa;
605
606 inftl_write_oob(mtd, writeEUN * inftl->EraseSize +
607 SECTORSIZE * 4 + 8, 8, &retlen, (char *)&oob.u);
608
609 inftl->PUtable[writeEUN] = inftl->VUtable[thisVUC];
610 inftl->VUtable[thisVUC] = writeEUN;
611
612 inftl->numfreeEUNs--;
613 return writeEUN;
614
615 } while (silly2--);
616
617 printk(KERN_WARNING "INFTL: error folding to make room for Virtual "
618 "Unit Chain 0x%x\n", thisVUC);
619 return BLOCK_NIL;
620}
621
622/*
623 * Given a Virtual Unit Chain, see if it can be deleted, and if so do it.
624 */
625static void INFTL_trydeletechain(struct INFTLrecord *inftl, unsigned thisVUC)
626{
627 struct mtd_info *mtd = inftl->mbd.mtd;
628 unsigned char BlockUsed[MAX_SECTORS_PER_UNIT];
629 unsigned char BlockDeleted[MAX_SECTORS_PER_UNIT];
630 unsigned int thisEUN, status;
631 int block, silly;
632 struct inftl_bci bci;
633 size_t retlen;
634
635 pr_debug("INFTL: INFTL_trydeletechain(inftl=%p,"
636 "thisVUC=%d)\n", inftl, thisVUC);
637
638 memset(BlockUsed, 0, sizeof(BlockUsed));
639 memset(BlockDeleted, 0, sizeof(BlockDeleted));
640
641 thisEUN = inftl->VUtable[thisVUC];
642 if (thisEUN == BLOCK_NIL) {
643 printk(KERN_WARNING "INFTL: trying to delete non-existent "
644 "Virtual Unit Chain %d!\n", thisVUC);
645 return;
646 }
647
648 /*
649 * Scan through the Erase Units to determine whether any data is in
650 * each of the 512-byte blocks within the Chain.
651 */
652 silly = MAX_LOOPS;
653 while (thisEUN < inftl->nb_blocks) {
654 for (block = 0; block < inftl->EraseSize/SECTORSIZE; block++) {
655 if (BlockUsed[block] || BlockDeleted[block])
656 continue;
657
658 if (inftl_read_oob(mtd, (thisEUN * inftl->EraseSize)
659 + (block * SECTORSIZE), 8 , &retlen,
660 (char *)&bci) < 0)
661 status = SECTOR_IGNORE;
662 else
663 status = bci.Status | bci.Status1;
664
665 switch(status) {
666 case SECTOR_FREE:
667 case SECTOR_IGNORE:
668 break;
669 case SECTOR_USED:
670 BlockUsed[block] = 1;
671 continue;
672 case SECTOR_DELETED:
673 BlockDeleted[block] = 1;
674 continue;
675 default:
676 printk(KERN_WARNING "INFTL: unknown status "
677 "for block %d in EUN %d: 0x%x\n",
678 block, thisEUN, status);
679 }
680 }
681
682 if (!silly--) {
683 printk(KERN_WARNING "INFTL: infinite loop in Virtual "
684 "Unit Chain 0x%x\n", thisVUC);
685 return;
686 }
687
688 thisEUN = inftl->PUtable[thisEUN];
689 }
690
691 for (block = 0; block < inftl->EraseSize/SECTORSIZE; block++)
692 if (BlockUsed[block])
693 return;
694
695 /*
696 * For each block in the chain free it and make it available
697 * for future use. Erase from the oldest unit first.
698 */
699 pr_debug("INFTL: deleting empty VUC %d\n", thisVUC);
700
701 for (;;) {
702 u16 *prevEUN = &inftl->VUtable[thisVUC];
703 thisEUN = *prevEUN;
704
705 /* If the chain is all gone already, we're done */
706 if (thisEUN == BLOCK_NIL) {
707 pr_debug("INFTL: Empty VUC %d for deletion was already absent\n", thisEUN);
708 return;
709 }
710
711 /* Find oldest unit in chain. */
712 while (inftl->PUtable[thisEUN] != BLOCK_NIL) {
713 BUG_ON(thisEUN >= inftl->nb_blocks);
714
715 prevEUN = &inftl->PUtable[thisEUN];
716 thisEUN = *prevEUN;
717 }
718
719 pr_debug("Deleting EUN %d from VUC %d\n",
720 thisEUN, thisVUC);
721
722 if (INFTL_formatblock(inftl, thisEUN) < 0) {
723 /*
724 * Could not erase : mark block as reserved.
725 */
726 inftl->PUtable[thisEUN] = BLOCK_RESERVED;
727 } else {
728 /* Correctly erased : mark it as free */
729 inftl->PUtable[thisEUN] = BLOCK_FREE;
730 inftl->numfreeEUNs++;
731 }
732
733 /* Now sort out whatever was pointing to it... */
734 *prevEUN = BLOCK_NIL;
735
736 /* Ideally we'd actually be responsive to new
737 requests while we're doing this -- if there's
738 free space why should others be made to wait? */
739 cond_resched();
740 }
741
742 inftl->VUtable[thisVUC] = BLOCK_NIL;
743}
744
745static int INFTL_deleteblock(struct INFTLrecord *inftl, unsigned block)
746{
747 unsigned int thisEUN = inftl->VUtable[block / (inftl->EraseSize / SECTORSIZE)];
748 unsigned long blockofs = (block * SECTORSIZE) & (inftl->EraseSize - 1);
749 struct mtd_info *mtd = inftl->mbd.mtd;
750 unsigned int status;
751 int silly = MAX_LOOPS;
752 size_t retlen;
753 struct inftl_bci bci;
754
755 pr_debug("INFTL: INFTL_deleteblock(inftl=%p,"
756 "block=%d)\n", inftl, block);
757
758 while (thisEUN < inftl->nb_blocks) {
759 if (inftl_read_oob(mtd, (thisEUN * inftl->EraseSize) +
760 blockofs, 8, &retlen, (char *)&bci) < 0)
761 status = SECTOR_IGNORE;
762 else
763 status = bci.Status | bci.Status1;
764
765 switch (status) {
766 case SECTOR_FREE:
767 case SECTOR_IGNORE:
768 break;
769 case SECTOR_DELETED:
770 thisEUN = BLOCK_NIL;
771 goto foundit;
772 case SECTOR_USED:
773 goto foundit;
774 default:
775 printk(KERN_WARNING "INFTL: unknown status for "
776 "block %d in EUN %d: 0x%x\n",
777 block, thisEUN, status);
778 break;
779 }
780
781 if (!silly--) {
782 printk(KERN_WARNING "INFTL: infinite loop in Virtual "
783 "Unit Chain 0x%x\n",
784 block / (inftl->EraseSize / SECTORSIZE));
785 return 1;
786 }
787 thisEUN = inftl->PUtable[thisEUN];
788 }
789
790foundit:
791 if (thisEUN != BLOCK_NIL) {
792 loff_t ptr = (thisEUN * inftl->EraseSize) + blockofs;
793
794 if (inftl_read_oob(mtd, ptr, 8, &retlen, (char *)&bci) < 0)
795 return -EIO;
796 bci.Status = bci.Status1 = SECTOR_DELETED;
797 if (inftl_write_oob(mtd, ptr, 8, &retlen, (char *)&bci) < 0)
798 return -EIO;
799 INFTL_trydeletechain(inftl, block / (inftl->EraseSize / SECTORSIZE));
800 }
801 return 0;
802}
803
804static int inftl_writeblock(struct mtd_blktrans_dev *mbd, unsigned long block,
805 char *buffer)
806{
807 struct INFTLrecord *inftl = (void *)mbd;
808 unsigned int writeEUN;
809 unsigned long blockofs = (block * SECTORSIZE) & (inftl->EraseSize - 1);
810 size_t retlen;
811 struct inftl_oob oob;
812 char *p, *pend;
813
814 pr_debug("INFTL: inftl_writeblock(inftl=%p,block=%ld,"
815 "buffer=%p)\n", inftl, block, buffer);
816
817 /* Is block all zero? */
818 pend = buffer + SECTORSIZE;
819 for (p = buffer; p < pend && !*p; p++)
820 ;
821
822 if (p < pend) {
823 writeEUN = INFTL_findwriteunit(inftl, block);
824
825 if (writeEUN == BLOCK_NIL) {
826 printk(KERN_WARNING "inftl_writeblock(): cannot find "
827 "block to write to\n");
828 /*
829 * If we _still_ haven't got a block to use,
830 * we're screwed.
831 */
832 return 1;
833 }
834
835 memset(&oob, 0xff, sizeof(struct inftl_oob));
836 oob.b.Status = oob.b.Status1 = SECTOR_USED;
837
838 inftl_write(inftl->mbd.mtd, (writeEUN * inftl->EraseSize) +
839 blockofs, SECTORSIZE, &retlen, (char *)buffer,
840 (char *)&oob);
841 /*
842 * need to write SECTOR_USED flags since they are not written
843 * in mtd_writeecc
844 */
845 } else {
846 INFTL_deleteblock(inftl, block);
847 }
848
849 return 0;
850}
851
852static int inftl_readblock(struct mtd_blktrans_dev *mbd, unsigned long block,
853 char *buffer)
854{
855 struct INFTLrecord *inftl = (void *)mbd;
856 unsigned int thisEUN = inftl->VUtable[block / (inftl->EraseSize / SECTORSIZE)];
857 unsigned long blockofs = (block * SECTORSIZE) & (inftl->EraseSize - 1);
858 struct mtd_info *mtd = inftl->mbd.mtd;
859 unsigned int status;
860 int silly = MAX_LOOPS;
861 struct inftl_bci bci;
862 size_t retlen;
863
864 pr_debug("INFTL: inftl_readblock(inftl=%p,block=%ld,"
865 "buffer=%p)\n", inftl, block, buffer);
866
867 while (thisEUN < inftl->nb_blocks) {
868 if (inftl_read_oob(mtd, (thisEUN * inftl->EraseSize) +
869 blockofs, 8, &retlen, (char *)&bci) < 0)
870 status = SECTOR_IGNORE;
871 else
872 status = bci.Status | bci.Status1;
873
874 switch (status) {
875 case SECTOR_DELETED:
876 thisEUN = BLOCK_NIL;
877 goto foundit;
878 case SECTOR_USED:
879 goto foundit;
880 case SECTOR_FREE:
881 case SECTOR_IGNORE:
882 break;
883 default:
884 printk(KERN_WARNING "INFTL: unknown status for "
885 "block %ld in EUN %d: 0x%04x\n",
886 block, thisEUN, status);
887 break;
888 }
889
890 if (!silly--) {
891 printk(KERN_WARNING "INFTL: infinite loop in "
892 "Virtual Unit Chain 0x%lx\n",
893 block / (inftl->EraseSize / SECTORSIZE));
894 return 1;
895 }
896
897 thisEUN = inftl->PUtable[thisEUN];
898 }
899
900foundit:
901 if (thisEUN == BLOCK_NIL) {
902 /* The requested block is not on the media, return all 0x00 */
903 memset(buffer, 0, SECTORSIZE);
904 } else {
905 size_t retlen;
906 loff_t ptr = (thisEUN * inftl->EraseSize) + blockofs;
907 int ret = mtd_read(mtd, ptr, SECTORSIZE, &retlen, buffer);
908
909 /* Handle corrected bit flips gracefully */
910 if (ret < 0 && !mtd_is_bitflip(ret))
911 return -EIO;
912 }
913 return 0;
914}
915
916static int inftl_getgeo(struct mtd_blktrans_dev *dev, struct hd_geometry *geo)
917{
918 struct INFTLrecord *inftl = (void *)dev;
919
920 geo->heads = inftl->heads;
921 geo->sectors = inftl->sectors;
922 geo->cylinders = inftl->cylinders;
923
924 return 0;
925}
926
927static struct mtd_blktrans_ops inftl_tr = {
928 .name = "inftl",
929 .major = INFTL_MAJOR,
930 .part_bits = INFTL_PARTN_BITS,
931 .blksize = 512,
932 .getgeo = inftl_getgeo,
933 .readsect = inftl_readblock,
934 .writesect = inftl_writeblock,
935 .add_mtd = inftl_add_mtd,
936 .remove_dev = inftl_remove_dev,
937 .owner = THIS_MODULE,
938};
939
940module_mtd_blktrans(inftl_tr);
941
942MODULE_LICENSE("GPL");
943MODULE_AUTHOR("Greg Ungerer <gerg@snapgear.com>, David Woodhouse <dwmw2@infradead.org>, Fabrice Bellard <fabrice.bellard@netgem.com> et al.");
944MODULE_DESCRIPTION("Support code for Inverse Flash Translation Layer, used on M-Systems DiskOnChip 2000, Millennium and Millennium Plus");
1/*
2 * inftlcore.c -- Linux driver for Inverse Flash Translation Layer (INFTL)
3 *
4 * Copyright © 2002, Greg Ungerer (gerg@snapgear.com)
5 *
6 * Based heavily on the nftlcore.c code which is:
7 * Copyright © 1999 Machine Vision Holdings, Inc.
8 * Copyright © 1999 David Woodhouse <dwmw2@infradead.org>
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 */
24
25#include <linux/kernel.h>
26#include <linux/module.h>
27#include <linux/delay.h>
28#include <linux/slab.h>
29#include <linux/sched.h>
30#include <linux/init.h>
31#include <linux/kmod.h>
32#include <linux/hdreg.h>
33#include <linux/mtd/mtd.h>
34#include <linux/mtd/nftl.h>
35#include <linux/mtd/inftl.h>
36#include <linux/mtd/nand.h>
37#include <asm/uaccess.h>
38#include <asm/errno.h>
39#include <asm/io.h>
40
41/*
42 * Maximum number of loops while examining next block, to have a
43 * chance to detect consistency problems (they should never happen
44 * because of the checks done in the mounting.
45 */
46#define MAX_LOOPS 10000
47
48static void inftl_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
49{
50 struct INFTLrecord *inftl;
51 unsigned long temp;
52
53 if (mtd->type != MTD_NANDFLASH || mtd->size > UINT_MAX)
54 return;
55 /* OK, this is moderately ugly. But probably safe. Alternatives? */
56 if (memcmp(mtd->name, "DiskOnChip", 10))
57 return;
58
59 if (!mtd->block_isbad) {
60 printk(KERN_ERR
61"INFTL no longer supports the old DiskOnChip drivers loaded via docprobe.\n"
62"Please use the new diskonchip driver under the NAND subsystem.\n");
63 return;
64 }
65
66 DEBUG(MTD_DEBUG_LEVEL3, "INFTL: add_mtd for %s\n", mtd->name);
67
68 inftl = kzalloc(sizeof(*inftl), GFP_KERNEL);
69
70 if (!inftl) {
71 printk(KERN_WARNING "INFTL: Out of memory for data structures\n");
72 return;
73 }
74
75 inftl->mbd.mtd = mtd;
76 inftl->mbd.devnum = -1;
77
78 inftl->mbd.tr = tr;
79
80 if (INFTL_mount(inftl) < 0) {
81 printk(KERN_WARNING "INFTL: could not mount device\n");
82 kfree(inftl);
83 return;
84 }
85
86 /* OK, it's a new one. Set up all the data structures. */
87
88 /* Calculate geometry */
89 inftl->cylinders = 1024;
90 inftl->heads = 16;
91
92 temp = inftl->cylinders * inftl->heads;
93 inftl->sectors = inftl->mbd.size / temp;
94 if (inftl->mbd.size % temp) {
95 inftl->sectors++;
96 temp = inftl->cylinders * inftl->sectors;
97 inftl->heads = inftl->mbd.size / temp;
98
99 if (inftl->mbd.size % temp) {
100 inftl->heads++;
101 temp = inftl->heads * inftl->sectors;
102 inftl->cylinders = inftl->mbd.size / temp;
103 }
104 }
105
106 if (inftl->mbd.size != inftl->heads * inftl->cylinders * inftl->sectors) {
107 /*
108 Oh no we don't have
109 mbd.size == heads * cylinders * sectors
110 */
111 printk(KERN_WARNING "INFTL: cannot calculate a geometry to "
112 "match size of 0x%lx.\n", inftl->mbd.size);
113 printk(KERN_WARNING "INFTL: using C:%d H:%d S:%d "
114 "(== 0x%lx sects)\n",
115 inftl->cylinders, inftl->heads , inftl->sectors,
116 (long)inftl->cylinders * (long)inftl->heads *
117 (long)inftl->sectors );
118 }
119
120 if (add_mtd_blktrans_dev(&inftl->mbd)) {
121 kfree(inftl->PUtable);
122 kfree(inftl->VUtable);
123 kfree(inftl);
124 return;
125 }
126#ifdef PSYCHO_DEBUG
127 printk(KERN_INFO "INFTL: Found new inftl%c\n", inftl->mbd.devnum + 'a');
128#endif
129 return;
130}
131
132static void inftl_remove_dev(struct mtd_blktrans_dev *dev)
133{
134 struct INFTLrecord *inftl = (void *)dev;
135
136 DEBUG(MTD_DEBUG_LEVEL3, "INFTL: remove_dev (i=%d)\n", dev->devnum);
137
138 del_mtd_blktrans_dev(dev);
139
140 kfree(inftl->PUtable);
141 kfree(inftl->VUtable);
142}
143
144/*
145 * Actual INFTL access routines.
146 */
147
148/*
149 * Read oob data from flash
150 */
151int inftl_read_oob(struct mtd_info *mtd, loff_t offs, size_t len,
152 size_t *retlen, uint8_t *buf)
153{
154 struct mtd_oob_ops ops;
155 int res;
156
157 ops.mode = MTD_OOB_PLACE;
158 ops.ooboffs = offs & (mtd->writesize - 1);
159 ops.ooblen = len;
160 ops.oobbuf = buf;
161 ops.datbuf = NULL;
162
163 res = mtd->read_oob(mtd, offs & ~(mtd->writesize - 1), &ops);
164 *retlen = ops.oobretlen;
165 return res;
166}
167
168/*
169 * Write oob data to flash
170 */
171int inftl_write_oob(struct mtd_info *mtd, loff_t offs, size_t len,
172 size_t *retlen, uint8_t *buf)
173{
174 struct mtd_oob_ops ops;
175 int res;
176
177 ops.mode = MTD_OOB_PLACE;
178 ops.ooboffs = offs & (mtd->writesize - 1);
179 ops.ooblen = len;
180 ops.oobbuf = buf;
181 ops.datbuf = NULL;
182
183 res = mtd->write_oob(mtd, offs & ~(mtd->writesize - 1), &ops);
184 *retlen = ops.oobretlen;
185 return res;
186}
187
188/*
189 * Write data and oob to flash
190 */
191static int inftl_write(struct mtd_info *mtd, loff_t offs, size_t len,
192 size_t *retlen, uint8_t *buf, uint8_t *oob)
193{
194 struct mtd_oob_ops ops;
195 int res;
196
197 ops.mode = MTD_OOB_PLACE;
198 ops.ooboffs = offs;
199 ops.ooblen = mtd->oobsize;
200 ops.oobbuf = oob;
201 ops.datbuf = buf;
202 ops.len = len;
203
204 res = mtd->write_oob(mtd, offs & ~(mtd->writesize - 1), &ops);
205 *retlen = ops.retlen;
206 return res;
207}
208
209/*
210 * INFTL_findfreeblock: Find a free Erase Unit on the INFTL partition.
211 * This function is used when the give Virtual Unit Chain.
212 */
213static u16 INFTL_findfreeblock(struct INFTLrecord *inftl, int desperate)
214{
215 u16 pot = inftl->LastFreeEUN;
216 int silly = inftl->nb_blocks;
217
218 DEBUG(MTD_DEBUG_LEVEL3, "INFTL: INFTL_findfreeblock(inftl=%p,"
219 "desperate=%d)\n", inftl, desperate);
220
221 /*
222 * Normally, we force a fold to happen before we run out of free
223 * blocks completely.
224 */
225 if (!desperate && inftl->numfreeEUNs < 2) {
226 DEBUG(MTD_DEBUG_LEVEL1, "INFTL: there are too few free "
227 "EUNs (%d)\n", inftl->numfreeEUNs);
228 return BLOCK_NIL;
229 }
230
231 /* Scan for a free block */
232 do {
233 if (inftl->PUtable[pot] == BLOCK_FREE) {
234 inftl->LastFreeEUN = pot;
235 return pot;
236 }
237
238 if (++pot > inftl->lastEUN)
239 pot = 0;
240
241 if (!silly--) {
242 printk(KERN_WARNING "INFTL: no free blocks found! "
243 "EUN range = %d - %d\n", 0, inftl->LastFreeEUN);
244 return BLOCK_NIL;
245 }
246 } while (pot != inftl->LastFreeEUN);
247
248 return BLOCK_NIL;
249}
250
251static u16 INFTL_foldchain(struct INFTLrecord *inftl, unsigned thisVUC, unsigned pendingblock)
252{
253 u16 BlockMap[MAX_SECTORS_PER_UNIT];
254 unsigned char BlockDeleted[MAX_SECTORS_PER_UNIT];
255 unsigned int thisEUN, prevEUN, status;
256 struct mtd_info *mtd = inftl->mbd.mtd;
257 int block, silly;
258 unsigned int targetEUN;
259 struct inftl_oob oob;
260 size_t retlen;
261
262 DEBUG(MTD_DEBUG_LEVEL3, "INFTL: INFTL_foldchain(inftl=%p,thisVUC=%d,"
263 "pending=%d)\n", inftl, thisVUC, pendingblock);
264
265 memset(BlockMap, 0xff, sizeof(BlockMap));
266 memset(BlockDeleted, 0, sizeof(BlockDeleted));
267
268 thisEUN = targetEUN = inftl->VUtable[thisVUC];
269
270 if (thisEUN == BLOCK_NIL) {
271 printk(KERN_WARNING "INFTL: trying to fold non-existent "
272 "Virtual Unit Chain %d!\n", thisVUC);
273 return BLOCK_NIL;
274 }
275
276 /*
277 * Scan to find the Erase Unit which holds the actual data for each
278 * 512-byte block within the Chain.
279 */
280 silly = MAX_LOOPS;
281 while (thisEUN < inftl->nb_blocks) {
282 for (block = 0; block < inftl->EraseSize/SECTORSIZE; block ++) {
283 if ((BlockMap[block] != BLOCK_NIL) ||
284 BlockDeleted[block])
285 continue;
286
287 if (inftl_read_oob(mtd, (thisEUN * inftl->EraseSize)
288 + (block * SECTORSIZE), 16, &retlen,
289 (char *)&oob) < 0)
290 status = SECTOR_IGNORE;
291 else
292 status = oob.b.Status | oob.b.Status1;
293
294 switch(status) {
295 case SECTOR_FREE:
296 case SECTOR_IGNORE:
297 break;
298 case SECTOR_USED:
299 BlockMap[block] = thisEUN;
300 continue;
301 case SECTOR_DELETED:
302 BlockDeleted[block] = 1;
303 continue;
304 default:
305 printk(KERN_WARNING "INFTL: unknown status "
306 "for block %d in EUN %d: %x\n",
307 block, thisEUN, status);
308 break;
309 }
310 }
311
312 if (!silly--) {
313 printk(KERN_WARNING "INFTL: infinite loop in Virtual "
314 "Unit Chain 0x%x\n", thisVUC);
315 return BLOCK_NIL;
316 }
317
318 thisEUN = inftl->PUtable[thisEUN];
319 }
320
321 /*
322 * OK. We now know the location of every block in the Virtual Unit
323 * Chain, and the Erase Unit into which we are supposed to be copying.
324 * Go for it.
325 */
326 DEBUG(MTD_DEBUG_LEVEL1, "INFTL: folding chain %d into unit %d\n",
327 thisVUC, targetEUN);
328
329 for (block = 0; block < inftl->EraseSize/SECTORSIZE ; block++) {
330 unsigned char movebuf[SECTORSIZE];
331 int ret;
332
333 /*
334 * If it's in the target EUN already, or if it's pending write,
335 * do nothing.
336 */
337 if (BlockMap[block] == targetEUN || (pendingblock ==
338 (thisVUC * (inftl->EraseSize / SECTORSIZE) + block))) {
339 continue;
340 }
341
342 /*
343 * Copy only in non free block (free blocks can only
344 * happen in case of media errors or deleted blocks).
345 */
346 if (BlockMap[block] == BLOCK_NIL)
347 continue;
348
349 ret = mtd->read(mtd, (inftl->EraseSize * BlockMap[block]) +
350 (block * SECTORSIZE), SECTORSIZE, &retlen,
351 movebuf);
352 if (ret < 0 && ret != -EUCLEAN) {
353 ret = mtd->read(mtd,
354 (inftl->EraseSize * BlockMap[block]) +
355 (block * SECTORSIZE), SECTORSIZE,
356 &retlen, movebuf);
357 if (ret != -EIO)
358 DEBUG(MTD_DEBUG_LEVEL1, "INFTL: error went "
359 "away on retry?\n");
360 }
361 memset(&oob, 0xff, sizeof(struct inftl_oob));
362 oob.b.Status = oob.b.Status1 = SECTOR_USED;
363
364 inftl_write(inftl->mbd.mtd, (inftl->EraseSize * targetEUN) +
365 (block * SECTORSIZE), SECTORSIZE, &retlen,
366 movebuf, (char *)&oob);
367 }
368
369 /*
370 * Newest unit in chain now contains data from _all_ older units.
371 * So go through and erase each unit in chain, oldest first. (This
372 * is important, by doing oldest first if we crash/reboot then it
373 * it is relatively simple to clean up the mess).
374 */
375 DEBUG(MTD_DEBUG_LEVEL1, "INFTL: want to erase virtual chain %d\n",
376 thisVUC);
377
378 for (;;) {
379 /* Find oldest unit in chain. */
380 thisEUN = inftl->VUtable[thisVUC];
381 prevEUN = BLOCK_NIL;
382 while (inftl->PUtable[thisEUN] != BLOCK_NIL) {
383 prevEUN = thisEUN;
384 thisEUN = inftl->PUtable[thisEUN];
385 }
386
387 /* Check if we are all done */
388 if (thisEUN == targetEUN)
389 break;
390
391 /* Unlink the last block from the chain. */
392 inftl->PUtable[prevEUN] = BLOCK_NIL;
393
394 /* Now try to erase it. */
395 if (INFTL_formatblock(inftl, thisEUN) < 0) {
396 /*
397 * Could not erase : mark block as reserved.
398 */
399 inftl->PUtable[thisEUN] = BLOCK_RESERVED;
400 } else {
401 /* Correctly erased : mark it as free */
402 inftl->PUtable[thisEUN] = BLOCK_FREE;
403 inftl->numfreeEUNs++;
404 }
405 }
406
407 return targetEUN;
408}
409
410static u16 INFTL_makefreeblock(struct INFTLrecord *inftl, unsigned pendingblock)
411{
412 /*
413 * This is the part that needs some cleverness applied.
414 * For now, I'm doing the minimum applicable to actually
415 * get the thing to work.
416 * Wear-levelling and other clever stuff needs to be implemented
417 * and we also need to do some assessment of the results when
418 * the system loses power half-way through the routine.
419 */
420 u16 LongestChain = 0;
421 u16 ChainLength = 0, thislen;
422 u16 chain, EUN;
423
424 DEBUG(MTD_DEBUG_LEVEL3, "INFTL: INFTL_makefreeblock(inftl=%p,"
425 "pending=%d)\n", inftl, pendingblock);
426
427 for (chain = 0; chain < inftl->nb_blocks; chain++) {
428 EUN = inftl->VUtable[chain];
429 thislen = 0;
430
431 while (EUN <= inftl->lastEUN) {
432 thislen++;
433 EUN = inftl->PUtable[EUN];
434 if (thislen > 0xff00) {
435 printk(KERN_WARNING "INFTL: endless loop in "
436 "Virtual Chain %d: Unit %x\n",
437 chain, EUN);
438 /*
439 * Actually, don't return failure.
440 * Just ignore this chain and get on with it.
441 */
442 thislen = 0;
443 break;
444 }
445 }
446
447 if (thislen > ChainLength) {
448 ChainLength = thislen;
449 LongestChain = chain;
450 }
451 }
452
453 if (ChainLength < 2) {
454 printk(KERN_WARNING "INFTL: no Virtual Unit Chains available "
455 "for folding. Failing request\n");
456 return BLOCK_NIL;
457 }
458
459 return INFTL_foldchain(inftl, LongestChain, pendingblock);
460}
461
462static int nrbits(unsigned int val, int bitcount)
463{
464 int i, total = 0;
465
466 for (i = 0; (i < bitcount); i++)
467 total += (((0x1 << i) & val) ? 1 : 0);
468 return total;
469}
470
471/*
472 * INFTL_findwriteunit: Return the unit number into which we can write
473 * for this block. Make it available if it isn't already.
474 */
475static inline u16 INFTL_findwriteunit(struct INFTLrecord *inftl, unsigned block)
476{
477 unsigned int thisVUC = block / (inftl->EraseSize / SECTORSIZE);
478 unsigned int thisEUN, writeEUN, prev_block, status;
479 unsigned long blockofs = (block * SECTORSIZE) & (inftl->EraseSize -1);
480 struct mtd_info *mtd = inftl->mbd.mtd;
481 struct inftl_oob oob;
482 struct inftl_bci bci;
483 unsigned char anac, nacs, parity;
484 size_t retlen;
485 int silly, silly2 = 3;
486
487 DEBUG(MTD_DEBUG_LEVEL3, "INFTL: INFTL_findwriteunit(inftl=%p,"
488 "block=%d)\n", inftl, block);
489
490 do {
491 /*
492 * Scan the media to find a unit in the VUC which has
493 * a free space for the block in question.
494 */
495 writeEUN = BLOCK_NIL;
496 thisEUN = inftl->VUtable[thisVUC];
497 silly = MAX_LOOPS;
498
499 while (thisEUN <= inftl->lastEUN) {
500 inftl_read_oob(mtd, (thisEUN * inftl->EraseSize) +
501 blockofs, 8, &retlen, (char *)&bci);
502
503 status = bci.Status | bci.Status1;
504 DEBUG(MTD_DEBUG_LEVEL3, "INFTL: status of block %d in "
505 "EUN %d is %x\n", block , writeEUN, status);
506
507 switch(status) {
508 case SECTOR_FREE:
509 writeEUN = thisEUN;
510 break;
511 case SECTOR_DELETED:
512 case SECTOR_USED:
513 /* Can't go any further */
514 goto hitused;
515 case SECTOR_IGNORE:
516 break;
517 default:
518 /*
519 * Invalid block. Don't use it any more.
520 * Must implement.
521 */
522 break;
523 }
524
525 if (!silly--) {
526 printk(KERN_WARNING "INFTL: infinite loop in "
527 "Virtual Unit Chain 0x%x\n", thisVUC);
528 return BLOCK_NIL;
529 }
530
531 /* Skip to next block in chain */
532 thisEUN = inftl->PUtable[thisEUN];
533 }
534
535hitused:
536 if (writeEUN != BLOCK_NIL)
537 return writeEUN;
538
539
540 /*
541 * OK. We didn't find one in the existing chain, or there
542 * is no existing chain. Allocate a new one.
543 */
544 writeEUN = INFTL_findfreeblock(inftl, 0);
545
546 if (writeEUN == BLOCK_NIL) {
547 /*
548 * That didn't work - there were no free blocks just
549 * waiting to be picked up. We're going to have to fold
550 * a chain to make room.
551 */
552 thisEUN = INFTL_makefreeblock(inftl, block);
553
554 /*
555 * Hopefully we free something, lets try again.
556 * This time we are desperate...
557 */
558 DEBUG(MTD_DEBUG_LEVEL1, "INFTL: using desperate==1 "
559 "to find free EUN to accommodate write to "
560 "VUC %d\n", thisVUC);
561 writeEUN = INFTL_findfreeblock(inftl, 1);
562 if (writeEUN == BLOCK_NIL) {
563 /*
564 * Ouch. This should never happen - we should
565 * always be able to make some room somehow.
566 * If we get here, we've allocated more storage
567 * space than actual media, or our makefreeblock
568 * routine is missing something.
569 */
570 printk(KERN_WARNING "INFTL: cannot make free "
571 "space.\n");
572#ifdef DEBUG
573 INFTL_dumptables(inftl);
574 INFTL_dumpVUchains(inftl);
575#endif
576 return BLOCK_NIL;
577 }
578 }
579
580 /*
581 * Insert new block into virtual chain. Firstly update the
582 * block headers in flash...
583 */
584 anac = 0;
585 nacs = 0;
586 thisEUN = inftl->VUtable[thisVUC];
587 if (thisEUN != BLOCK_NIL) {
588 inftl_read_oob(mtd, thisEUN * inftl->EraseSize
589 + 8, 8, &retlen, (char *)&oob.u);
590 anac = oob.u.a.ANAC + 1;
591 nacs = oob.u.a.NACs + 1;
592 }
593
594 prev_block = inftl->VUtable[thisVUC];
595 if (prev_block < inftl->nb_blocks)
596 prev_block -= inftl->firstEUN;
597
598 parity = (nrbits(thisVUC, 16) & 0x1) ? 0x1 : 0;
599 parity |= (nrbits(prev_block, 16) & 0x1) ? 0x2 : 0;
600 parity |= (nrbits(anac, 8) & 0x1) ? 0x4 : 0;
601 parity |= (nrbits(nacs, 8) & 0x1) ? 0x8 : 0;
602
603 oob.u.a.virtualUnitNo = cpu_to_le16(thisVUC);
604 oob.u.a.prevUnitNo = cpu_to_le16(prev_block);
605 oob.u.a.ANAC = anac;
606 oob.u.a.NACs = nacs;
607 oob.u.a.parityPerField = parity;
608 oob.u.a.discarded = 0xaa;
609
610 inftl_write_oob(mtd, writeEUN * inftl->EraseSize + 8, 8,
611 &retlen, (char *)&oob.u);
612
613 /* Also back up header... */
614 oob.u.b.virtualUnitNo = cpu_to_le16(thisVUC);
615 oob.u.b.prevUnitNo = cpu_to_le16(prev_block);
616 oob.u.b.ANAC = anac;
617 oob.u.b.NACs = nacs;
618 oob.u.b.parityPerField = parity;
619 oob.u.b.discarded = 0xaa;
620
621 inftl_write_oob(mtd, writeEUN * inftl->EraseSize +
622 SECTORSIZE * 4 + 8, 8, &retlen, (char *)&oob.u);
623
624 inftl->PUtable[writeEUN] = inftl->VUtable[thisVUC];
625 inftl->VUtable[thisVUC] = writeEUN;
626
627 inftl->numfreeEUNs--;
628 return writeEUN;
629
630 } while (silly2--);
631
632 printk(KERN_WARNING "INFTL: error folding to make room for Virtual "
633 "Unit Chain 0x%x\n", thisVUC);
634 return BLOCK_NIL;
635}
636
637/*
638 * Given a Virtual Unit Chain, see if it can be deleted, and if so do it.
639 */
640static void INFTL_trydeletechain(struct INFTLrecord *inftl, unsigned thisVUC)
641{
642 struct mtd_info *mtd = inftl->mbd.mtd;
643 unsigned char BlockUsed[MAX_SECTORS_PER_UNIT];
644 unsigned char BlockDeleted[MAX_SECTORS_PER_UNIT];
645 unsigned int thisEUN, status;
646 int block, silly;
647 struct inftl_bci bci;
648 size_t retlen;
649
650 DEBUG(MTD_DEBUG_LEVEL3, "INFTL: INFTL_trydeletechain(inftl=%p,"
651 "thisVUC=%d)\n", inftl, thisVUC);
652
653 memset(BlockUsed, 0, sizeof(BlockUsed));
654 memset(BlockDeleted, 0, sizeof(BlockDeleted));
655
656 thisEUN = inftl->VUtable[thisVUC];
657 if (thisEUN == BLOCK_NIL) {
658 printk(KERN_WARNING "INFTL: trying to delete non-existent "
659 "Virtual Unit Chain %d!\n", thisVUC);
660 return;
661 }
662
663 /*
664 * Scan through the Erase Units to determine whether any data is in
665 * each of the 512-byte blocks within the Chain.
666 */
667 silly = MAX_LOOPS;
668 while (thisEUN < inftl->nb_blocks) {
669 for (block = 0; block < inftl->EraseSize/SECTORSIZE; block++) {
670 if (BlockUsed[block] || BlockDeleted[block])
671 continue;
672
673 if (inftl_read_oob(mtd, (thisEUN * inftl->EraseSize)
674 + (block * SECTORSIZE), 8 , &retlen,
675 (char *)&bci) < 0)
676 status = SECTOR_IGNORE;
677 else
678 status = bci.Status | bci.Status1;
679
680 switch(status) {
681 case SECTOR_FREE:
682 case SECTOR_IGNORE:
683 break;
684 case SECTOR_USED:
685 BlockUsed[block] = 1;
686 continue;
687 case SECTOR_DELETED:
688 BlockDeleted[block] = 1;
689 continue;
690 default:
691 printk(KERN_WARNING "INFTL: unknown status "
692 "for block %d in EUN %d: 0x%x\n",
693 block, thisEUN, status);
694 }
695 }
696
697 if (!silly--) {
698 printk(KERN_WARNING "INFTL: infinite loop in Virtual "
699 "Unit Chain 0x%x\n", thisVUC);
700 return;
701 }
702
703 thisEUN = inftl->PUtable[thisEUN];
704 }
705
706 for (block = 0; block < inftl->EraseSize/SECTORSIZE; block++)
707 if (BlockUsed[block])
708 return;
709
710 /*
711 * For each block in the chain free it and make it available
712 * for future use. Erase from the oldest unit first.
713 */
714 DEBUG(MTD_DEBUG_LEVEL1, "INFTL: deleting empty VUC %d\n", thisVUC);
715
716 for (;;) {
717 u16 *prevEUN = &inftl->VUtable[thisVUC];
718 thisEUN = *prevEUN;
719
720 /* If the chain is all gone already, we're done */
721 if (thisEUN == BLOCK_NIL) {
722 DEBUG(MTD_DEBUG_LEVEL2, "INFTL: Empty VUC %d for deletion was already absent\n", thisEUN);
723 return;
724 }
725
726 /* Find oldest unit in chain. */
727 while (inftl->PUtable[thisEUN] != BLOCK_NIL) {
728 BUG_ON(thisEUN >= inftl->nb_blocks);
729
730 prevEUN = &inftl->PUtable[thisEUN];
731 thisEUN = *prevEUN;
732 }
733
734 DEBUG(MTD_DEBUG_LEVEL3, "Deleting EUN %d from VUC %d\n",
735 thisEUN, thisVUC);
736
737 if (INFTL_formatblock(inftl, thisEUN) < 0) {
738 /*
739 * Could not erase : mark block as reserved.
740 */
741 inftl->PUtable[thisEUN] = BLOCK_RESERVED;
742 } else {
743 /* Correctly erased : mark it as free */
744 inftl->PUtable[thisEUN] = BLOCK_FREE;
745 inftl->numfreeEUNs++;
746 }
747
748 /* Now sort out whatever was pointing to it... */
749 *prevEUN = BLOCK_NIL;
750
751 /* Ideally we'd actually be responsive to new
752 requests while we're doing this -- if there's
753 free space why should others be made to wait? */
754 cond_resched();
755 }
756
757 inftl->VUtable[thisVUC] = BLOCK_NIL;
758}
759
760static int INFTL_deleteblock(struct INFTLrecord *inftl, unsigned block)
761{
762 unsigned int thisEUN = inftl->VUtable[block / (inftl->EraseSize / SECTORSIZE)];
763 unsigned long blockofs = (block * SECTORSIZE) & (inftl->EraseSize - 1);
764 struct mtd_info *mtd = inftl->mbd.mtd;
765 unsigned int status;
766 int silly = MAX_LOOPS;
767 size_t retlen;
768 struct inftl_bci bci;
769
770 DEBUG(MTD_DEBUG_LEVEL3, "INFTL: INFTL_deleteblock(inftl=%p,"
771 "block=%d)\n", inftl, block);
772
773 while (thisEUN < inftl->nb_blocks) {
774 if (inftl_read_oob(mtd, (thisEUN * inftl->EraseSize) +
775 blockofs, 8, &retlen, (char *)&bci) < 0)
776 status = SECTOR_IGNORE;
777 else
778 status = bci.Status | bci.Status1;
779
780 switch (status) {
781 case SECTOR_FREE:
782 case SECTOR_IGNORE:
783 break;
784 case SECTOR_DELETED:
785 thisEUN = BLOCK_NIL;
786 goto foundit;
787 case SECTOR_USED:
788 goto foundit;
789 default:
790 printk(KERN_WARNING "INFTL: unknown status for "
791 "block %d in EUN %d: 0x%x\n",
792 block, thisEUN, status);
793 break;
794 }
795
796 if (!silly--) {
797 printk(KERN_WARNING "INFTL: infinite loop in Virtual "
798 "Unit Chain 0x%x\n",
799 block / (inftl->EraseSize / SECTORSIZE));
800 return 1;
801 }
802 thisEUN = inftl->PUtable[thisEUN];
803 }
804
805foundit:
806 if (thisEUN != BLOCK_NIL) {
807 loff_t ptr = (thisEUN * inftl->EraseSize) + blockofs;
808
809 if (inftl_read_oob(mtd, ptr, 8, &retlen, (char *)&bci) < 0)
810 return -EIO;
811 bci.Status = bci.Status1 = SECTOR_DELETED;
812 if (inftl_write_oob(mtd, ptr, 8, &retlen, (char *)&bci) < 0)
813 return -EIO;
814 INFTL_trydeletechain(inftl, block / (inftl->EraseSize / SECTORSIZE));
815 }
816 return 0;
817}
818
819static int inftl_writeblock(struct mtd_blktrans_dev *mbd, unsigned long block,
820 char *buffer)
821{
822 struct INFTLrecord *inftl = (void *)mbd;
823 unsigned int writeEUN;
824 unsigned long blockofs = (block * SECTORSIZE) & (inftl->EraseSize - 1);
825 size_t retlen;
826 struct inftl_oob oob;
827 char *p, *pend;
828
829 DEBUG(MTD_DEBUG_LEVEL3, "INFTL: inftl_writeblock(inftl=%p,block=%ld,"
830 "buffer=%p)\n", inftl, block, buffer);
831
832 /* Is block all zero? */
833 pend = buffer + SECTORSIZE;
834 for (p = buffer; p < pend && !*p; p++)
835 ;
836
837 if (p < pend) {
838 writeEUN = INFTL_findwriteunit(inftl, block);
839
840 if (writeEUN == BLOCK_NIL) {
841 printk(KERN_WARNING "inftl_writeblock(): cannot find "
842 "block to write to\n");
843 /*
844 * If we _still_ haven't got a block to use,
845 * we're screwed.
846 */
847 return 1;
848 }
849
850 memset(&oob, 0xff, sizeof(struct inftl_oob));
851 oob.b.Status = oob.b.Status1 = SECTOR_USED;
852
853 inftl_write(inftl->mbd.mtd, (writeEUN * inftl->EraseSize) +
854 blockofs, SECTORSIZE, &retlen, (char *)buffer,
855 (char *)&oob);
856 /*
857 * need to write SECTOR_USED flags since they are not written
858 * in mtd_writeecc
859 */
860 } else {
861 INFTL_deleteblock(inftl, block);
862 }
863
864 return 0;
865}
866
867static int inftl_readblock(struct mtd_blktrans_dev *mbd, unsigned long block,
868 char *buffer)
869{
870 struct INFTLrecord *inftl = (void *)mbd;
871 unsigned int thisEUN = inftl->VUtable[block / (inftl->EraseSize / SECTORSIZE)];
872 unsigned long blockofs = (block * SECTORSIZE) & (inftl->EraseSize - 1);
873 struct mtd_info *mtd = inftl->mbd.mtd;
874 unsigned int status;
875 int silly = MAX_LOOPS;
876 struct inftl_bci bci;
877 size_t retlen;
878
879 DEBUG(MTD_DEBUG_LEVEL3, "INFTL: inftl_readblock(inftl=%p,block=%ld,"
880 "buffer=%p)\n", inftl, block, buffer);
881
882 while (thisEUN < inftl->nb_blocks) {
883 if (inftl_read_oob(mtd, (thisEUN * inftl->EraseSize) +
884 blockofs, 8, &retlen, (char *)&bci) < 0)
885 status = SECTOR_IGNORE;
886 else
887 status = bci.Status | bci.Status1;
888
889 switch (status) {
890 case SECTOR_DELETED:
891 thisEUN = BLOCK_NIL;
892 goto foundit;
893 case SECTOR_USED:
894 goto foundit;
895 case SECTOR_FREE:
896 case SECTOR_IGNORE:
897 break;
898 default:
899 printk(KERN_WARNING "INFTL: unknown status for "
900 "block %ld in EUN %d: 0x%04x\n",
901 block, thisEUN, status);
902 break;
903 }
904
905 if (!silly--) {
906 printk(KERN_WARNING "INFTL: infinite loop in "
907 "Virtual Unit Chain 0x%lx\n",
908 block / (inftl->EraseSize / SECTORSIZE));
909 return 1;
910 }
911
912 thisEUN = inftl->PUtable[thisEUN];
913 }
914
915foundit:
916 if (thisEUN == BLOCK_NIL) {
917 /* The requested block is not on the media, return all 0x00 */
918 memset(buffer, 0, SECTORSIZE);
919 } else {
920 size_t retlen;
921 loff_t ptr = (thisEUN * inftl->EraseSize) + blockofs;
922 int ret = mtd->read(mtd, ptr, SECTORSIZE, &retlen, buffer);
923
924 /* Handle corrected bit flips gracefully */
925 if (ret < 0 && ret != -EUCLEAN)
926 return -EIO;
927 }
928 return 0;
929}
930
931static int inftl_getgeo(struct mtd_blktrans_dev *dev, struct hd_geometry *geo)
932{
933 struct INFTLrecord *inftl = (void *)dev;
934
935 geo->heads = inftl->heads;
936 geo->sectors = inftl->sectors;
937 geo->cylinders = inftl->cylinders;
938
939 return 0;
940}
941
942static struct mtd_blktrans_ops inftl_tr = {
943 .name = "inftl",
944 .major = INFTL_MAJOR,
945 .part_bits = INFTL_PARTN_BITS,
946 .blksize = 512,
947 .getgeo = inftl_getgeo,
948 .readsect = inftl_readblock,
949 .writesect = inftl_writeblock,
950 .add_mtd = inftl_add_mtd,
951 .remove_dev = inftl_remove_dev,
952 .owner = THIS_MODULE,
953};
954
955static int __init init_inftl(void)
956{
957 return register_mtd_blktrans(&inftl_tr);
958}
959
960static void __exit cleanup_inftl(void)
961{
962 deregister_mtd_blktrans(&inftl_tr);
963}
964
965module_init(init_inftl);
966module_exit(cleanup_inftl);
967
968MODULE_LICENSE("GPL");
969MODULE_AUTHOR("Greg Ungerer <gerg@snapgear.com>, David Woodhouse <dwmw2@infradead.org>, Fabrice Bellard <fabrice.bellard@netgem.com> et al.");
970MODULE_DESCRIPTION("Support code for Inverse Flash Translation Layer, used on M-Systems DiskOnChip 2000, Millennium and Millennium Plus");