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
inftl_add_mtd(struct mtd_blktrans_ops * tr,struct mtd_info * mtd)35 static 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
inftl_remove_dev(struct mtd_blktrans_dev * dev)117 static 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 */
inftl_read_oob(struct mtd_info * mtd,loff_t offs,size_t len,size_t * retlen,uint8_t * buf)136 int 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 */
inftl_write_oob(struct mtd_info * mtd,loff_t offs,size_t len,size_t * retlen,uint8_t * buf)156 int 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 */
inftl_write(struct mtd_info * mtd,loff_t offs,size_t len,size_t * retlen,uint8_t * buf,uint8_t * oob)176 static 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 */
INFTL_findfreeblock(struct INFTLrecord * inftl,int desperate)198 static 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
INFTL_foldchain(struct INFTLrecord * inftl,unsigned thisVUC,unsigned pendingblock)236 static 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
INFTL_makefreeblock(struct INFTLrecord * inftl,unsigned pendingblock)395 static 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
nrbits(unsigned int val,int bitcount)447 static 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 */
INFTL_findwriteunit(struct INFTLrecord * inftl,unsigned block)460 static 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
520 hitused:
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 */
INFTL_trydeletechain(struct INFTLrecord * inftl,unsigned thisVUC)625 static 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
INFTL_deleteblock(struct INFTLrecord * inftl,unsigned block)745 static 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
790 foundit:
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
inftl_writeblock(struct mtd_blktrans_dev * mbd,unsigned long block,char * buffer)804 static 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
inftl_readblock(struct mtd_blktrans_dev * mbd,unsigned long block,char * buffer)852 static 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
900 foundit:
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
inftl_getgeo(struct mtd_blktrans_dev * dev,struct hd_geometry * geo)916 static 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
927 static 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
940 module_mtd_blktrans(inftl_tr);
941
942 MODULE_LICENSE("GPL");
943 MODULE_AUTHOR("Greg Ungerer <gerg@snapgear.com>, David Woodhouse <dwmw2@infradead.org>, Fabrice Bellard <fabrice.bellard@netgem.com> et al.");
944 MODULE_DESCRIPTION("Support code for Inverse Flash Translation Layer, used on M-Systems DiskOnChip 2000, Millennium and Millennium Plus");
945