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