ia64/linux-2.6.18-xen.hg

view drivers/mtd/inftlcore.c @ 893:f994bfe9b93b

linux/blktap2: reduce TLB flush scope

c/s 885 added very coarse TLB flushing. Since these flushes always
follow single page updates, single page flushes (when available) are
sufficient.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
author Keir Fraser <keir.fraser@citrix.com>
date Thu Jun 04 10:32:57 2009 +0100 (2009-06-04)
parents 831230e53067
children
line source
1 /*
2 * inftlcore.c -- Linux driver for Inverse Flash Translation Layer (INFTL)
3 *
4 * (C) Copyright 2002, Greg Ungerer (gerg@snapgear.com)
5 *
6 * Based heavily on the nftlcore.c code which is:
7 * (c) 1999 Machine Vision Holdings, Inc.
8 * Author: David Woodhouse <dwmw2@infradead.org>
9 *
10 * $Id: inftlcore.c,v 1.19 2005/11/07 11:14:20 gleixner Exp $
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
16 *
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
21 *
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
25 */
27 #include <linux/kernel.h>
28 #include <linux/module.h>
29 #include <linux/delay.h>
30 #include <linux/slab.h>
31 #include <linux/sched.h>
32 #include <linux/init.h>
33 #include <linux/kmod.h>
34 #include <linux/hdreg.h>
35 #include <linux/mtd/mtd.h>
36 #include <linux/mtd/nftl.h>
37 #include <linux/mtd/inftl.h>
38 #include <linux/mtd/nand.h>
39 #include <asm/uaccess.h>
40 #include <asm/errno.h>
41 #include <asm/io.h>
43 /*
44 * Maximum number of loops while examining next block, to have a
45 * chance to detect consistency problems (they should never happen
46 * because of the checks done in the mounting.
47 */
48 #define MAX_LOOPS 10000
50 static void inftl_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
51 {
52 struct INFTLrecord *inftl;
53 unsigned long temp;
55 if (mtd->type != MTD_NANDFLASH)
56 return;
57 /* OK, this is moderately ugly. But probably safe. Alternatives? */
58 if (memcmp(mtd->name, "DiskOnChip", 10))
59 return;
61 if (!mtd->block_isbad) {
62 printk(KERN_ERR
63 "INFTL no longer supports the old DiskOnChip drivers loaded via docprobe.\n"
64 "Please use the new diskonchip driver under the NAND subsystem.\n");
65 return;
66 }
68 DEBUG(MTD_DEBUG_LEVEL3, "INFTL: add_mtd for %s\n", mtd->name);
70 inftl = kmalloc(sizeof(*inftl), GFP_KERNEL);
72 if (!inftl) {
73 printk(KERN_WARNING "INFTL: Out of memory for data structures\n");
74 return;
75 }
76 memset(inftl, 0, sizeof(*inftl));
78 inftl->mbd.mtd = mtd;
79 inftl->mbd.devnum = -1;
80 inftl->mbd.blksize = 512;
81 inftl->mbd.tr = tr;
83 if (INFTL_mount(inftl) < 0) {
84 printk(KERN_WARNING "INFTL: could not mount device\n");
85 kfree(inftl);
86 return;
87 }
89 /* OK, it's a new one. Set up all the data structures. */
91 /* Calculate geometry */
92 inftl->cylinders = 1024;
93 inftl->heads = 16;
95 temp = inftl->cylinders * inftl->heads;
96 inftl->sectors = inftl->mbd.size / temp;
97 if (inftl->mbd.size % temp) {
98 inftl->sectors++;
99 temp = inftl->cylinders * inftl->sectors;
100 inftl->heads = inftl->mbd.size / temp;
102 if (inftl->mbd.size % temp) {
103 inftl->heads++;
104 temp = inftl->heads * inftl->sectors;
105 inftl->cylinders = inftl->mbd.size / temp;
106 }
107 }
109 if (inftl->mbd.size != inftl->heads * inftl->cylinders * inftl->sectors) {
110 /*
111 Oh no we don't have
112 mbd.size == heads * cylinders * sectors
113 */
114 printk(KERN_WARNING "INFTL: cannot calculate a geometry to "
115 "match size of 0x%lx.\n", inftl->mbd.size);
116 printk(KERN_WARNING "INFTL: using C:%d H:%d S:%d "
117 "(== 0x%lx sects)\n",
118 inftl->cylinders, inftl->heads , inftl->sectors,
119 (long)inftl->cylinders * (long)inftl->heads *
120 (long)inftl->sectors );
121 }
123 if (add_mtd_blktrans_dev(&inftl->mbd)) {
124 kfree(inftl->PUtable);
125 kfree(inftl->VUtable);
126 kfree(inftl);
127 return;
128 }
129 #ifdef PSYCHO_DEBUG
130 printk(KERN_INFO "INFTL: Found new inftl%c\n", inftl->mbd.devnum + 'a');
131 #endif
132 return;
133 }
135 static void inftl_remove_dev(struct mtd_blktrans_dev *dev)
136 {
137 struct INFTLrecord *inftl = (void *)dev;
139 DEBUG(MTD_DEBUG_LEVEL3, "INFTL: remove_dev (i=%d)\n", dev->devnum);
141 del_mtd_blktrans_dev(dev);
143 kfree(inftl->PUtable);
144 kfree(inftl->VUtable);
145 kfree(inftl);
146 }
148 /*
149 * Actual INFTL access routines.
150 */
152 /*
153 * Read oob data from flash
154 */
155 int inftl_read_oob(struct mtd_info *mtd, loff_t offs, size_t len,
156 size_t *retlen, uint8_t *buf)
157 {
158 struct mtd_oob_ops ops;
159 int res;
161 ops.mode = MTD_OOB_PLACE;
162 ops.ooboffs = offs & (mtd->writesize - 1);
163 ops.ooblen = len;
164 ops.oobbuf = buf;
165 ops.datbuf = NULL;
166 ops.len = len;
168 res = mtd->read_oob(mtd, offs & ~(mtd->writesize - 1), &ops);
169 *retlen = ops.retlen;
170 return res;
171 }
173 /*
174 * Write oob data to flash
175 */
176 int inftl_write_oob(struct mtd_info *mtd, loff_t offs, size_t len,
177 size_t *retlen, uint8_t *buf)
178 {
179 struct mtd_oob_ops ops;
180 int res;
182 ops.mode = MTD_OOB_PLACE;
183 ops.ooboffs = offs & (mtd->writesize - 1);
184 ops.ooblen = len;
185 ops.oobbuf = buf;
186 ops.datbuf = NULL;
187 ops.len = len;
189 res = mtd->write_oob(mtd, offs & ~(mtd->writesize - 1), &ops);
190 *retlen = ops.retlen;
191 return res;
192 }
194 /*
195 * Write data and oob to flash
196 */
197 static int inftl_write(struct mtd_info *mtd, loff_t offs, size_t len,
198 size_t *retlen, uint8_t *buf, uint8_t *oob)
199 {
200 struct mtd_oob_ops ops;
201 int res;
203 ops.mode = MTD_OOB_PLACE;
204 ops.ooboffs = offs;
205 ops.ooblen = mtd->oobsize;
206 ops.oobbuf = oob;
207 ops.datbuf = buf;
208 ops.len = len;
210 res = mtd->write_oob(mtd, offs & ~(mtd->writesize - 1), &ops);
211 *retlen = ops.retlen;
212 return res;
213 }
215 /*
216 * INFTL_findfreeblock: Find a free Erase Unit on the INFTL partition.
217 * This function is used when the give Virtual Unit Chain.
218 */
219 static u16 INFTL_findfreeblock(struct INFTLrecord *inftl, int desperate)
220 {
221 u16 pot = inftl->LastFreeEUN;
222 int silly = inftl->nb_blocks;
224 DEBUG(MTD_DEBUG_LEVEL3, "INFTL: INFTL_findfreeblock(inftl=%p,"
225 "desperate=%d)\n", inftl, desperate);
227 /*
228 * Normally, we force a fold to happen before we run out of free
229 * blocks completely.
230 */
231 if (!desperate && inftl->numfreeEUNs < 2) {
232 DEBUG(MTD_DEBUG_LEVEL1, "INFTL: there are too few free "
233 "EUNs (%d)\n", inftl->numfreeEUNs);
234 return 0xffff;
235 }
237 /* Scan for a free block */
238 do {
239 if (inftl->PUtable[pot] == BLOCK_FREE) {
240 inftl->LastFreeEUN = pot;
241 return pot;
242 }
244 if (++pot > inftl->lastEUN)
245 pot = 0;
247 if (!silly--) {
248 printk(KERN_WARNING "INFTL: no free blocks found! "
249 "EUN range = %d - %d\n", 0, inftl->LastFreeEUN);
250 return BLOCK_NIL;
251 }
252 } while (pot != inftl->LastFreeEUN);
254 return BLOCK_NIL;
255 }
257 static u16 INFTL_foldchain(struct INFTLrecord *inftl, unsigned thisVUC, unsigned pendingblock)
258 {
259 u16 BlockMap[MAX_SECTORS_PER_UNIT];
260 unsigned char BlockDeleted[MAX_SECTORS_PER_UNIT];
261 unsigned int thisEUN, prevEUN, status;
262 struct mtd_info *mtd = inftl->mbd.mtd;
263 int block, silly;
264 unsigned int targetEUN;
265 struct inftl_oob oob;
266 size_t retlen;
268 DEBUG(MTD_DEBUG_LEVEL3, "INFTL: INFTL_foldchain(inftl=%p,thisVUC=%d,"
269 "pending=%d)\n", inftl, thisVUC, pendingblock);
271 memset(BlockMap, 0xff, sizeof(BlockMap));
272 memset(BlockDeleted, 0, sizeof(BlockDeleted));
274 thisEUN = targetEUN = inftl->VUtable[thisVUC];
276 if (thisEUN == BLOCK_NIL) {
277 printk(KERN_WARNING "INFTL: trying to fold non-existent "
278 "Virtual Unit Chain %d!\n", thisVUC);
279 return BLOCK_NIL;
280 }
282 /*
283 * Scan to find the Erase Unit which holds the actual data for each
284 * 512-byte block within the Chain.
285 */
286 silly = MAX_LOOPS;
287 while (thisEUN < inftl->nb_blocks) {
288 for (block = 0; block < inftl->EraseSize/SECTORSIZE; block ++) {
289 if ((BlockMap[block] != 0xffff) || BlockDeleted[block])
290 continue;
292 if (inftl_read_oob(mtd, (thisEUN * inftl->EraseSize)
293 + (block * SECTORSIZE), 16, &retlen,
294 (char *)&oob) < 0)
295 status = SECTOR_IGNORE;
296 else
297 status = oob.b.Status | oob.b.Status1;
299 switch(status) {
300 case SECTOR_FREE:
301 case SECTOR_IGNORE:
302 break;
303 case SECTOR_USED:
304 BlockMap[block] = thisEUN;
305 continue;
306 case SECTOR_DELETED:
307 BlockDeleted[block] = 1;
308 continue;
309 default:
310 printk(KERN_WARNING "INFTL: unknown status "
311 "for block %d in EUN %d: %x\n",
312 block, thisEUN, status);
313 break;
314 }
315 }
317 if (!silly--) {
318 printk(KERN_WARNING "INFTL: infinite loop in Virtual "
319 "Unit Chain 0x%x\n", thisVUC);
320 return BLOCK_NIL;
321 }
323 thisEUN = inftl->PUtable[thisEUN];
324 }
326 /*
327 * OK. We now know the location of every block in the Virtual Unit
328 * Chain, and the Erase Unit into which we are supposed to be copying.
329 * Go for it.
330 */
331 DEBUG(MTD_DEBUG_LEVEL1, "INFTL: folding chain %d into unit %d\n",
332 thisVUC, targetEUN);
334 for (block = 0; block < inftl->EraseSize/SECTORSIZE ; block++) {
335 unsigned char movebuf[SECTORSIZE];
336 int ret;
338 /*
339 * If it's in the target EUN already, or if it's pending write,
340 * do nothing.
341 */
342 if (BlockMap[block] == targetEUN || (pendingblock ==
343 (thisVUC * (inftl->EraseSize / SECTORSIZE) + block))) {
344 continue;
345 }
347 /*
348 * Copy only in non free block (free blocks can only
349 * happen in case of media errors or deleted blocks).
350 */
351 if (BlockMap[block] == BLOCK_NIL)
352 continue;
354 ret = mtd->read(mtd, (inftl->EraseSize * BlockMap[block]) +
355 (block * SECTORSIZE), SECTORSIZE, &retlen,
356 movebuf);
357 if (ret < 0 && ret != -EUCLEAN) {
358 ret = mtd->read(mtd,
359 (inftl->EraseSize * BlockMap[block]) +
360 (block * SECTORSIZE), SECTORSIZE,
361 &retlen, movebuf);
362 if (ret != -EIO)
363 DEBUG(MTD_DEBUG_LEVEL1, "INFTL: error went "
364 "away on retry?\n");
365 }
366 memset(&oob, 0xff, sizeof(struct inftl_oob));
367 oob.b.Status = oob.b.Status1 = SECTOR_USED;
369 inftl_write(inftl->mbd.mtd, (inftl->EraseSize * targetEUN) +
370 (block * SECTORSIZE), SECTORSIZE, &retlen,
371 movebuf, (char *)&oob);
372 }
374 /*
375 * Newest unit in chain now contains data from _all_ older units.
376 * So go through and erase each unit in chain, oldest first. (This
377 * is important, by doing oldest first if we crash/reboot then it
378 * it is relatively simple to clean up the mess).
379 */
380 DEBUG(MTD_DEBUG_LEVEL1, "INFTL: want to erase virtual chain %d\n",
381 thisVUC);
383 for (;;) {
384 /* Find oldest unit in chain. */
385 thisEUN = inftl->VUtable[thisVUC];
386 prevEUN = BLOCK_NIL;
387 while (inftl->PUtable[thisEUN] != BLOCK_NIL) {
388 prevEUN = thisEUN;
389 thisEUN = inftl->PUtable[thisEUN];
390 }
392 /* Check if we are all done */
393 if (thisEUN == targetEUN)
394 break;
396 if (INFTL_formatblock(inftl, thisEUN) < 0) {
397 /*
398 * Could not erase : mark block as reserved.
399 */
400 inftl->PUtable[thisEUN] = BLOCK_RESERVED;
401 } else {
402 /* Correctly erased : mark it as free */
403 inftl->PUtable[thisEUN] = BLOCK_FREE;
404 inftl->PUtable[prevEUN] = BLOCK_NIL;
405 inftl->numfreeEUNs++;
406 }
407 }
409 return targetEUN;
410 }
412 static u16 INFTL_makefreeblock(struct INFTLrecord *inftl, unsigned pendingblock)
413 {
414 /*
415 * This is the part that needs some cleverness applied.
416 * For now, I'm doing the minimum applicable to actually
417 * get the thing to work.
418 * Wear-levelling and other clever stuff needs to be implemented
419 * and we also need to do some assessment of the results when
420 * the system loses power half-way through the routine.
421 */
422 u16 LongestChain = 0;
423 u16 ChainLength = 0, thislen;
424 u16 chain, EUN;
426 DEBUG(MTD_DEBUG_LEVEL3, "INFTL: INFTL_makefreeblock(inftl=%p,"
427 "pending=%d)\n", inftl, pendingblock);
429 for (chain = 0; chain < inftl->nb_blocks; chain++) {
430 EUN = inftl->VUtable[chain];
431 thislen = 0;
433 while (EUN <= inftl->lastEUN) {
434 thislen++;
435 EUN = inftl->PUtable[EUN];
436 if (thislen > 0xff00) {
437 printk(KERN_WARNING "INFTL: endless loop in "
438 "Virtual Chain %d: Unit %x\n",
439 chain, EUN);
440 /*
441 * Actually, don't return failure.
442 * Just ignore this chain and get on with it.
443 */
444 thislen = 0;
445 break;
446 }
447 }
449 if (thislen > ChainLength) {
450 ChainLength = thislen;
451 LongestChain = chain;
452 }
453 }
455 if (ChainLength < 2) {
456 printk(KERN_WARNING "INFTL: no Virtual Unit Chains available "
457 "for folding. Failing request\n");
458 return BLOCK_NIL;
459 }
461 return INFTL_foldchain(inftl, LongestChain, pendingblock);
462 }
464 static int nrbits(unsigned int val, int bitcount)
465 {
466 int i, total = 0;
468 for (i = 0; (i < bitcount); i++)
469 total += (((0x1 << i) & val) ? 1 : 0);
470 return total;
471 }
473 /*
474 * INFTL_findwriteunit: Return the unit number into which we can write
475 * for this block. Make it available if it isn't already.
476 */
477 static inline u16 INFTL_findwriteunit(struct INFTLrecord *inftl, unsigned block)
478 {
479 unsigned int thisVUC = block / (inftl->EraseSize / SECTORSIZE);
480 unsigned int thisEUN, writeEUN, prev_block, status;
481 unsigned long blockofs = (block * SECTORSIZE) & (inftl->EraseSize -1);
482 struct mtd_info *mtd = inftl->mbd.mtd;
483 struct inftl_oob oob;
484 struct inftl_bci bci;
485 unsigned char anac, nacs, parity;
486 size_t retlen;
487 int silly, silly2 = 3;
489 DEBUG(MTD_DEBUG_LEVEL3, "INFTL: INFTL_findwriteunit(inftl=%p,"
490 "block=%d)\n", inftl, block);
492 do {
493 /*
494 * Scan the media to find a unit in the VUC which has
495 * a free space for the block in question.
496 */
497 writeEUN = BLOCK_NIL;
498 thisEUN = inftl->VUtable[thisVUC];
499 silly = MAX_LOOPS;
501 while (thisEUN <= inftl->lastEUN) {
502 inftl_read_oob(mtd, (thisEUN * inftl->EraseSize) +
503 blockofs, 8, &retlen, (char *)&bci);
505 status = bci.Status | bci.Status1;
506 DEBUG(MTD_DEBUG_LEVEL3, "INFTL: status of block %d in "
507 "EUN %d is %x\n", block , writeEUN, status);
509 switch(status) {
510 case SECTOR_FREE:
511 writeEUN = thisEUN;
512 break;
513 case SECTOR_DELETED:
514 case SECTOR_USED:
515 /* Can't go any further */
516 goto hitused;
517 case SECTOR_IGNORE:
518 break;
519 default:
520 /*
521 * Invalid block. Don't use it any more.
522 * Must implement.
523 */
524 break;
525 }
527 if (!silly--) {
528 printk(KERN_WARNING "INFTL: infinite loop in "
529 "Virtual Unit Chain 0x%x\n", thisVUC);
530 return 0xffff;
531 }
533 /* Skip to next block in chain */
534 thisEUN = inftl->PUtable[thisEUN];
535 }
537 hitused:
538 if (writeEUN != BLOCK_NIL)
539 return writeEUN;
542 /*
543 * OK. We didn't find one in the existing chain, or there
544 * is no existing chain. Allocate a new one.
545 */
546 writeEUN = INFTL_findfreeblock(inftl, 0);
548 if (writeEUN == BLOCK_NIL) {
549 /*
550 * That didn't work - there were no free blocks just
551 * waiting to be picked up. We're going to have to fold
552 * a chain to make room.
553 */
554 thisEUN = INFTL_makefreeblock(inftl, 0xffff);
556 /*
557 * Hopefully we free something, lets try again.
558 * This time we are desperate...
559 */
560 DEBUG(MTD_DEBUG_LEVEL1, "INFTL: using desperate==1 "
561 "to find free EUN to accommodate write to "
562 "VUC %d\n", thisVUC);
563 writeEUN = INFTL_findfreeblock(inftl, 1);
564 if (writeEUN == BLOCK_NIL) {
565 /*
566 * Ouch. This should never happen - we should
567 * always be able to make some room somehow.
568 * If we get here, we've allocated more storage
569 * space than actual media, or our makefreeblock
570 * routine is missing something.
571 */
572 printk(KERN_WARNING "INFTL: cannot make free "
573 "space.\n");
574 #ifdef DEBUG
575 INFTL_dumptables(inftl);
576 INFTL_dumpVUchains(inftl);
577 #endif
578 return BLOCK_NIL;
579 }
580 }
582 /*
583 * Insert new block into virtual chain. Firstly update the
584 * block headers in flash...
585 */
586 anac = 0;
587 nacs = 0;
588 thisEUN = inftl->VUtable[thisVUC];
589 if (thisEUN != BLOCK_NIL) {
590 inftl_read_oob(mtd, thisEUN * inftl->EraseSize
591 + 8, 8, &retlen, (char *)&oob.u);
592 anac = oob.u.a.ANAC + 1;
593 nacs = oob.u.a.NACs + 1;
594 }
596 prev_block = inftl->VUtable[thisVUC];
597 if (prev_block < inftl->nb_blocks)
598 prev_block -= inftl->firstEUN;
600 parity = (nrbits(thisVUC, 16) & 0x1) ? 0x1 : 0;
601 parity |= (nrbits(prev_block, 16) & 0x1) ? 0x2 : 0;
602 parity |= (nrbits(anac, 8) & 0x1) ? 0x4 : 0;
603 parity |= (nrbits(nacs, 8) & 0x1) ? 0x8 : 0;
605 oob.u.a.virtualUnitNo = cpu_to_le16(thisVUC);
606 oob.u.a.prevUnitNo = cpu_to_le16(prev_block);
607 oob.u.a.ANAC = anac;
608 oob.u.a.NACs = nacs;
609 oob.u.a.parityPerField = parity;
610 oob.u.a.discarded = 0xaa;
612 inftl_write_oob(mtd, writeEUN * inftl->EraseSize + 8, 8,
613 &retlen, (char *)&oob.u);
615 /* Also back up header... */
616 oob.u.b.virtualUnitNo = cpu_to_le16(thisVUC);
617 oob.u.b.prevUnitNo = cpu_to_le16(prev_block);
618 oob.u.b.ANAC = anac;
619 oob.u.b.NACs = nacs;
620 oob.u.b.parityPerField = parity;
621 oob.u.b.discarded = 0xaa;
623 inftl_write_oob(mtd, writeEUN * inftl->EraseSize +
624 SECTORSIZE * 4 + 8, 8, &retlen, (char *)&oob.u);
626 inftl->PUtable[writeEUN] = inftl->VUtable[thisVUC];
627 inftl->VUtable[thisVUC] = writeEUN;
629 inftl->numfreeEUNs--;
630 return writeEUN;
632 } while (silly2--);
634 printk(KERN_WARNING "INFTL: error folding to make room for Virtual "
635 "Unit Chain 0x%x\n", thisVUC);
636 return 0xffff;
637 }
639 /*
640 * Given a Virtual Unit Chain, see if it can be deleted, and if so do it.
641 */
642 static void INFTL_trydeletechain(struct INFTLrecord *inftl, unsigned thisVUC)
643 {
644 struct mtd_info *mtd = inftl->mbd.mtd;
645 unsigned char BlockUsed[MAX_SECTORS_PER_UNIT];
646 unsigned char BlockDeleted[MAX_SECTORS_PER_UNIT];
647 unsigned int thisEUN, status;
648 int block, silly;
649 struct inftl_bci bci;
650 size_t retlen;
652 DEBUG(MTD_DEBUG_LEVEL3, "INFTL: INFTL_trydeletechain(inftl=%p,"
653 "thisVUC=%d)\n", inftl, thisVUC);
655 memset(BlockUsed, 0, sizeof(BlockUsed));
656 memset(BlockDeleted, 0, sizeof(BlockDeleted));
658 thisEUN = inftl->VUtable[thisVUC];
659 if (thisEUN == BLOCK_NIL) {
660 printk(KERN_WARNING "INFTL: trying to delete non-existent "
661 "Virtual Unit Chain %d!\n", thisVUC);
662 return;
663 }
665 /*
666 * Scan through the Erase Units to determine whether any data is in
667 * each of the 512-byte blocks within the Chain.
668 */
669 silly = MAX_LOOPS;
670 while (thisEUN < inftl->nb_blocks) {
671 for (block = 0; block < inftl->EraseSize/SECTORSIZE; block++) {
672 if (BlockUsed[block] || BlockDeleted[block])
673 continue;
675 if (inftl_read_oob(mtd, (thisEUN * inftl->EraseSize)
676 + (block * SECTORSIZE), 8 , &retlen,
677 (char *)&bci) < 0)
678 status = SECTOR_IGNORE;
679 else
680 status = bci.Status | bci.Status1;
682 switch(status) {
683 case SECTOR_FREE:
684 case SECTOR_IGNORE:
685 break;
686 case SECTOR_USED:
687 BlockUsed[block] = 1;
688 continue;
689 case SECTOR_DELETED:
690 BlockDeleted[block] = 1;
691 continue;
692 default:
693 printk(KERN_WARNING "INFTL: unknown status "
694 "for block %d in EUN %d: 0x%x\n",
695 block, thisEUN, status);
696 }
697 }
699 if (!silly--) {
700 printk(KERN_WARNING "INFTL: infinite loop in Virtual "
701 "Unit Chain 0x%x\n", thisVUC);
702 return;
703 }
705 thisEUN = inftl->PUtable[thisEUN];
706 }
708 for (block = 0; block < inftl->EraseSize/SECTORSIZE; block++)
709 if (BlockUsed[block])
710 return;
712 /*
713 * For each block in the chain free it and make it available
714 * for future use. Erase from the oldest unit first.
715 */
716 DEBUG(MTD_DEBUG_LEVEL1, "INFTL: deleting empty VUC %d\n", thisVUC);
718 for (;;) {
719 u16 *prevEUN = &inftl->VUtable[thisVUC];
720 thisEUN = *prevEUN;
722 /* If the chain is all gone already, we're done */
723 if (thisEUN == BLOCK_NIL) {
724 DEBUG(MTD_DEBUG_LEVEL2, "INFTL: Empty VUC %d for deletion was already absent\n", thisEUN);
725 return;
726 }
728 /* Find oldest unit in chain. */
729 while (inftl->PUtable[thisEUN] != BLOCK_NIL) {
730 BUG_ON(thisEUN >= inftl->nb_blocks);
732 prevEUN = &inftl->PUtable[thisEUN];
733 thisEUN = *prevEUN;
734 }
736 DEBUG(MTD_DEBUG_LEVEL3, "Deleting EUN %d from VUC %d\n",
737 thisEUN, thisVUC);
739 if (INFTL_formatblock(inftl, thisEUN) < 0) {
740 /*
741 * Could not erase : mark block as reserved.
742 */
743 inftl->PUtable[thisEUN] = BLOCK_RESERVED;
744 } else {
745 /* Correctly erased : mark it as free */
746 inftl->PUtable[thisEUN] = BLOCK_FREE;
747 inftl->numfreeEUNs++;
748 }
750 /* Now sort out whatever was pointing to it... */
751 *prevEUN = BLOCK_NIL;
753 /* Ideally we'd actually be responsive to new
754 requests while we're doing this -- if there's
755 free space why should others be made to wait? */
756 cond_resched();
757 }
759 inftl->VUtable[thisVUC] = BLOCK_NIL;
760 }
762 static int INFTL_deleteblock(struct INFTLrecord *inftl, unsigned block)
763 {
764 unsigned int thisEUN = inftl->VUtable[block / (inftl->EraseSize / SECTORSIZE)];
765 unsigned long blockofs = (block * SECTORSIZE) & (inftl->EraseSize - 1);
766 struct mtd_info *mtd = inftl->mbd.mtd;
767 unsigned int status;
768 int silly = MAX_LOOPS;
769 size_t retlen;
770 struct inftl_bci bci;
772 DEBUG(MTD_DEBUG_LEVEL3, "INFTL: INFTL_deleteblock(inftl=%p,"
773 "block=%d)\n", inftl, block);
775 while (thisEUN < inftl->nb_blocks) {
776 if (inftl_read_oob(mtd, (thisEUN * inftl->EraseSize) +
777 blockofs, 8, &retlen, (char *)&bci) < 0)
778 status = SECTOR_IGNORE;
779 else
780 status = bci.Status | bci.Status1;
782 switch (status) {
783 case SECTOR_FREE:
784 case SECTOR_IGNORE:
785 break;
786 case SECTOR_DELETED:
787 thisEUN = BLOCK_NIL;
788 goto foundit;
789 case SECTOR_USED:
790 goto foundit;
791 default:
792 printk(KERN_WARNING "INFTL: unknown status for "
793 "block %d in EUN %d: 0x%x\n",
794 block, thisEUN, status);
795 break;
796 }
798 if (!silly--) {
799 printk(KERN_WARNING "INFTL: infinite loop in Virtual "
800 "Unit Chain 0x%x\n",
801 block / (inftl->EraseSize / SECTORSIZE));
802 return 1;
803 }
804 thisEUN = inftl->PUtable[thisEUN];
805 }
807 foundit:
808 if (thisEUN != BLOCK_NIL) {
809 loff_t ptr = (thisEUN * inftl->EraseSize) + blockofs;
811 if (inftl_read_oob(mtd, ptr, 8, &retlen, (char *)&bci) < 0)
812 return -EIO;
813 bci.Status = bci.Status1 = SECTOR_DELETED;
814 if (inftl_write_oob(mtd, ptr, 8, &retlen, (char *)&bci) < 0)
815 return -EIO;
816 INFTL_trydeletechain(inftl, block / (inftl->EraseSize / SECTORSIZE));
817 }
818 return 0;
819 }
821 static int inftl_writeblock(struct mtd_blktrans_dev *mbd, unsigned long block,
822 char *buffer)
823 {
824 struct INFTLrecord *inftl = (void *)mbd;
825 unsigned int writeEUN;
826 unsigned long blockofs = (block * SECTORSIZE) & (inftl->EraseSize - 1);
827 size_t retlen;
828 struct inftl_oob oob;
829 char *p, *pend;
831 DEBUG(MTD_DEBUG_LEVEL3, "INFTL: inftl_writeblock(inftl=%p,block=%ld,"
832 "buffer=%p)\n", inftl, block, buffer);
834 /* Is block all zero? */
835 pend = buffer + SECTORSIZE;
836 for (p = buffer; p < pend && !*p; p++)
837 ;
839 if (p < pend) {
840 writeEUN = INFTL_findwriteunit(inftl, block);
842 if (writeEUN == BLOCK_NIL) {
843 printk(KERN_WARNING "inftl_writeblock(): cannot find "
844 "block to write to\n");
845 /*
846 * If we _still_ haven't got a block to use,
847 * we're screwed.
848 */
849 return 1;
850 }
852 memset(&oob, 0xff, sizeof(struct inftl_oob));
853 oob.b.Status = oob.b.Status1 = SECTOR_USED;
855 inftl_write(inftl->mbd.mtd, (writeEUN * inftl->EraseSize) +
856 blockofs, SECTORSIZE, &retlen, (char *)buffer,
857 (char *)&oob);
858 /*
859 * need to write SECTOR_USED flags since they are not written
860 * in mtd_writeecc
861 */
862 } else {
863 INFTL_deleteblock(inftl, block);
864 }
866 return 0;
867 }
869 static int inftl_readblock(struct mtd_blktrans_dev *mbd, unsigned long block,
870 char *buffer)
871 {
872 struct INFTLrecord *inftl = (void *)mbd;
873 unsigned int thisEUN = inftl->VUtable[block / (inftl->EraseSize / SECTORSIZE)];
874 unsigned long blockofs = (block * SECTORSIZE) & (inftl->EraseSize - 1);
875 struct mtd_info *mtd = inftl->mbd.mtd;
876 unsigned int status;
877 int silly = MAX_LOOPS;
878 struct inftl_bci bci;
879 size_t retlen;
881 DEBUG(MTD_DEBUG_LEVEL3, "INFTL: inftl_readblock(inftl=%p,block=%ld,"
882 "buffer=%p)\n", inftl, block, buffer);
884 while (thisEUN < inftl->nb_blocks) {
885 if (inftl_read_oob(mtd, (thisEUN * inftl->EraseSize) +
886 blockofs, 8, &retlen, (char *)&bci) < 0)
887 status = SECTOR_IGNORE;
888 else
889 status = bci.Status | bci.Status1;
891 switch (status) {
892 case SECTOR_DELETED:
893 thisEUN = BLOCK_NIL;
894 goto foundit;
895 case SECTOR_USED:
896 goto foundit;
897 case SECTOR_FREE:
898 case SECTOR_IGNORE:
899 break;
900 default:
901 printk(KERN_WARNING "INFTL: unknown status for "
902 "block %ld in EUN %d: 0x%04x\n",
903 block, thisEUN, status);
904 break;
905 }
907 if (!silly--) {
908 printk(KERN_WARNING "INFTL: infinite loop in "
909 "Virtual Unit Chain 0x%lx\n",
910 block / (inftl->EraseSize / SECTORSIZE));
911 return 1;
912 }
914 thisEUN = inftl->PUtable[thisEUN];
915 }
917 foundit:
918 if (thisEUN == BLOCK_NIL) {
919 /* The requested block is not on the media, return all 0x00 */
920 memset(buffer, 0, SECTORSIZE);
921 } else {
922 size_t retlen;
923 loff_t ptr = (thisEUN * inftl->EraseSize) + blockofs;
924 int ret = mtd->read(mtd, ptr, SECTORSIZE, &retlen, buffer);
926 /* Handle corrected bit flips gracefully */
927 if (ret < 0 && ret != -EUCLEAN)
928 return -EIO;
929 }
930 return 0;
931 }
933 static int inftl_getgeo(struct mtd_blktrans_dev *dev, struct hd_geometry *geo)
934 {
935 struct INFTLrecord *inftl = (void *)dev;
937 geo->heads = inftl->heads;
938 geo->sectors = inftl->sectors;
939 geo->cylinders = inftl->cylinders;
941 return 0;
942 }
944 static struct mtd_blktrans_ops inftl_tr = {
945 .name = "inftl",
946 .major = INFTL_MAJOR,
947 .part_bits = INFTL_PARTN_BITS,
948 .getgeo = inftl_getgeo,
949 .readsect = inftl_readblock,
950 .writesect = inftl_writeblock,
951 .add_mtd = inftl_add_mtd,
952 .remove_dev = inftl_remove_dev,
953 .owner = THIS_MODULE,
954 };
956 static int __init init_inftl(void)
957 {
958 printk(KERN_INFO "INFTL: inftlcore.c $Revision: 1.19 $, "
959 "inftlmount.c %s\n", inftlmountrev);
961 return register_mtd_blktrans(&inftl_tr);
962 }
964 static void __exit cleanup_inftl(void)
965 {
966 deregister_mtd_blktrans(&inftl_tr);
967 }
969 module_init(init_inftl);
970 module_exit(cleanup_inftl);
972 MODULE_LICENSE("GPL");
973 MODULE_AUTHOR("Greg Ungerer <gerg@snapgear.com>, David Woodhouse <dwmw2@infradead.org>, Fabrice Bellard <fabrice.bellard@netgem.com> et al.");
974 MODULE_DESCRIPTION("Support code for Inverse Flash Translation Layer, used on M-Systems DiskOnChip 2000, Millennium and Millennium Plus");