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1 | /* | |
2 | * Linux driver for NAND Flash Translation Layer | |
3 | * | |
4 | * Copyright © 1999 Machine Vision Holdings, Inc. | |
5 | * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License as published by | |
9 | * the Free Software Foundation; either version 2 of the License, or | |
10 | * (at your option) any later version. | |
11 | * | |
12 | * This program is distributed in the hope that it will be useful, | |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | * GNU General Public License for more details. | |
16 | * | |
17 | * You should have received a copy of the GNU General Public License | |
18 | * along with this program; if not, write to the Free Software | |
19 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
20 | */ | |
21 | ||
22 | #define PRERELEASE | |
23 | ||
24 | #include <linux/kernel.h> | |
25 | #include <linux/module.h> | |
26 | #include <asm/errno.h> | |
27 | #include <asm/io.h> | |
28 | #include <asm/uaccess.h> | |
29 | #include <linux/delay.h> | |
30 | #include <linux/slab.h> | |
31 | #include <linux/init.h> | |
32 | #include <linux/hdreg.h> | |
33 | #include <linux/blkdev.h> | |
34 | ||
35 | #include <linux/kmod.h> | |
36 | #include <linux/mtd/mtd.h> | |
37 | #include <linux/mtd/nand.h> | |
38 | #include <linux/mtd/nftl.h> | |
39 | #include <linux/mtd/blktrans.h> | |
40 | ||
41 | /* maximum number of loops while examining next block, to have a | |
42 | chance to detect consistency problems (they should never happen | |
43 | because of the checks done in the mounting */ | |
44 | ||
45 | #define MAX_LOOPS 10000 | |
46 | ||
47 | ||
48 | static void nftl_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd) | |
49 | { | |
50 | struct NFTLrecord *nftl; | |
51 | unsigned long temp; | |
52 | ||
53 | if (mtd->type != MTD_NANDFLASH || mtd->size > UINT_MAX) | |
54 | return; | |
55 | /* OK, this is moderately ugly. But probably safe. Alternatives? */ | |
56 | if (memcmp(mtd->name, "DiskOnChip", 10)) | |
57 | return; | |
58 | ||
59 | if (!mtd->block_isbad) { | |
60 | printk(KERN_ERR | |
61 | "NFTL no longer supports the old DiskOnChip drivers loaded via docprobe.\n" | |
62 | "Please use the new diskonchip driver under the NAND subsystem.\n"); | |
63 | return; | |
64 | } | |
65 | ||
66 | DEBUG(MTD_DEBUG_LEVEL1, "NFTL: add_mtd for %s\n", mtd->name); | |
67 | ||
68 | nftl = kzalloc(sizeof(struct NFTLrecord), GFP_KERNEL); | |
69 | ||
70 | if (!nftl) { | |
71 | printk(KERN_WARNING "NFTL: out of memory for data structures\n"); | |
72 | return; | |
73 | } | |
74 | ||
75 | nftl->mbd.mtd = mtd; | |
76 | nftl->mbd.devnum = -1; | |
77 | ||
78 | nftl->mbd.tr = tr; | |
79 | ||
80 | if (NFTL_mount(nftl) < 0) { | |
81 | printk(KERN_WARNING "NFTL: could not mount device\n"); | |
82 | kfree(nftl); | |
83 | return; | |
84 | } | |
85 | ||
86 | /* OK, it's a new one. Set up all the data structures. */ | |
87 | ||
88 | /* Calculate geometry */ | |
89 | nftl->cylinders = 1024; | |
90 | nftl->heads = 16; | |
91 | ||
92 | temp = nftl->cylinders * nftl->heads; | |
93 | nftl->sectors = nftl->mbd.size / temp; | |
94 | if (nftl->mbd.size % temp) { | |
95 | nftl->sectors++; | |
96 | temp = nftl->cylinders * nftl->sectors; | |
97 | nftl->heads = nftl->mbd.size / temp; | |
98 | ||
99 | if (nftl->mbd.size % temp) { | |
100 | nftl->heads++; | |
101 | temp = nftl->heads * nftl->sectors; | |
102 | nftl->cylinders = nftl->mbd.size / temp; | |
103 | } | |
104 | } | |
105 | ||
106 | if (nftl->mbd.size != nftl->heads * nftl->cylinders * nftl->sectors) { | |
107 | /* | |
108 | Oh no we don't have | |
109 | mbd.size == heads * cylinders * sectors | |
110 | */ | |
111 | printk(KERN_WARNING "NFTL: cannot calculate a geometry to " | |
112 | "match size of 0x%lx.\n", nftl->mbd.size); | |
113 | printk(KERN_WARNING "NFTL: using C:%d H:%d S:%d " | |
114 | "(== 0x%lx sects)\n", | |
115 | nftl->cylinders, nftl->heads , nftl->sectors, | |
116 | (long)nftl->cylinders * (long)nftl->heads * | |
117 | (long)nftl->sectors ); | |
118 | } | |
119 | ||
120 | if (add_mtd_blktrans_dev(&nftl->mbd)) { | |
121 | kfree(nftl->ReplUnitTable); | |
122 | kfree(nftl->EUNtable); | |
123 | kfree(nftl); | |
124 | return; | |
125 | } | |
126 | #ifdef PSYCHO_DEBUG | |
127 | printk(KERN_INFO "NFTL: Found new nftl%c\n", nftl->mbd.devnum + 'a'); | |
128 | #endif | |
129 | } | |
130 | ||
131 | static void nftl_remove_dev(struct mtd_blktrans_dev *dev) | |
132 | { | |
133 | struct NFTLrecord *nftl = (void *)dev; | |
134 | ||
135 | DEBUG(MTD_DEBUG_LEVEL1, "NFTL: remove_dev (i=%d)\n", dev->devnum); | |
136 | ||
137 | del_mtd_blktrans_dev(dev); | |
138 | kfree(nftl->ReplUnitTable); | |
139 | kfree(nftl->EUNtable); | |
140 | } | |
141 | ||
142 | /* | |
143 | * Read oob data from flash | |
144 | */ | |
145 | int nftl_read_oob(struct mtd_info *mtd, loff_t offs, size_t len, | |
146 | size_t *retlen, uint8_t *buf) | |
147 | { | |
148 | loff_t mask = mtd->writesize - 1; | |
149 | struct mtd_oob_ops ops; | |
150 | int res; | |
151 | ||
152 | ops.mode = MTD_OOB_PLACE; | |
153 | ops.ooboffs = offs & mask; | |
154 | ops.ooblen = len; | |
155 | ops.oobbuf = buf; | |
156 | ops.datbuf = NULL; | |
157 | ||
158 | res = mtd->read_oob(mtd, offs & ~mask, &ops); | |
159 | *retlen = ops.oobretlen; | |
160 | return res; | |
161 | } | |
162 | ||
163 | /* | |
164 | * Write oob data to flash | |
165 | */ | |
166 | int nftl_write_oob(struct mtd_info *mtd, loff_t offs, size_t len, | |
167 | size_t *retlen, uint8_t *buf) | |
168 | { | |
169 | loff_t mask = mtd->writesize - 1; | |
170 | struct mtd_oob_ops ops; | |
171 | int res; | |
172 | ||
173 | ops.mode = MTD_OOB_PLACE; | |
174 | ops.ooboffs = offs & mask; | |
175 | ops.ooblen = len; | |
176 | ops.oobbuf = buf; | |
177 | ops.datbuf = NULL; | |
178 | ||
179 | res = mtd->write_oob(mtd, offs & ~mask, &ops); | |
180 | *retlen = ops.oobretlen; | |
181 | return res; | |
182 | } | |
183 | ||
184 | #ifdef CONFIG_NFTL_RW | |
185 | ||
186 | /* | |
187 | * Write data and oob to flash | |
188 | */ | |
189 | static int nftl_write(struct mtd_info *mtd, loff_t offs, size_t len, | |
190 | size_t *retlen, uint8_t *buf, uint8_t *oob) | |
191 | { | |
192 | loff_t mask = mtd->writesize - 1; | |
193 | struct mtd_oob_ops ops; | |
194 | int res; | |
195 | ||
196 | ops.mode = MTD_OOB_PLACE; | |
197 | ops.ooboffs = offs & mask; | |
198 | ops.ooblen = mtd->oobsize; | |
199 | ops.oobbuf = oob; | |
200 | ops.datbuf = buf; | |
201 | ops.len = len; | |
202 | ||
203 | res = mtd->write_oob(mtd, offs & ~mask, &ops); | |
204 | *retlen = ops.retlen; | |
205 | return res; | |
206 | } | |
207 | ||
208 | /* Actual NFTL access routines */ | |
209 | /* NFTL_findfreeblock: Find a free Erase Unit on the NFTL partition. This function is used | |
210 | * when the give Virtual Unit Chain | |
211 | */ | |
212 | static u16 NFTL_findfreeblock(struct NFTLrecord *nftl, int desperate ) | |
213 | { | |
214 | /* For a given Virtual Unit Chain: find or create a free block and | |
215 | add it to the chain */ | |
216 | /* We're passed the number of the last EUN in the chain, to save us from | |
217 | having to look it up again */ | |
218 | u16 pot = nftl->LastFreeEUN; | |
219 | int silly = nftl->nb_blocks; | |
220 | ||
221 | /* Normally, we force a fold to happen before we run out of free blocks completely */ | |
222 | if (!desperate && nftl->numfreeEUNs < 2) { | |
223 | DEBUG(MTD_DEBUG_LEVEL1, "NFTL_findfreeblock: there are too few free EUNs\n"); | |
224 | return BLOCK_NIL; | |
225 | } | |
226 | ||
227 | /* Scan for a free block */ | |
228 | do { | |
229 | if (nftl->ReplUnitTable[pot] == BLOCK_FREE) { | |
230 | nftl->LastFreeEUN = pot; | |
231 | nftl->numfreeEUNs--; | |
232 | return pot; | |
233 | } | |
234 | ||
235 | /* This will probably point to the MediaHdr unit itself, | |
236 | right at the beginning of the partition. But that unit | |
237 | (and the backup unit too) should have the UCI set | |
238 | up so that it's not selected for overwriting */ | |
239 | if (++pot > nftl->lastEUN) | |
240 | pot = le16_to_cpu(nftl->MediaHdr.FirstPhysicalEUN); | |
241 | ||
242 | if (!silly--) { | |
243 | printk("Argh! No free blocks found! LastFreeEUN = %d, " | |
244 | "FirstEUN = %d\n", nftl->LastFreeEUN, | |
245 | le16_to_cpu(nftl->MediaHdr.FirstPhysicalEUN)); | |
246 | return BLOCK_NIL; | |
247 | } | |
248 | } while (pot != nftl->LastFreeEUN); | |
249 | ||
250 | return BLOCK_NIL; | |
251 | } | |
252 | ||
253 | static u16 NFTL_foldchain (struct NFTLrecord *nftl, unsigned thisVUC, unsigned pendingblock ) | |
254 | { | |
255 | struct mtd_info *mtd = nftl->mbd.mtd; | |
256 | u16 BlockMap[MAX_SECTORS_PER_UNIT]; | |
257 | unsigned char BlockLastState[MAX_SECTORS_PER_UNIT]; | |
258 | unsigned char BlockFreeFound[MAX_SECTORS_PER_UNIT]; | |
259 | unsigned int thisEUN; | |
260 | int block; | |
261 | int silly; | |
262 | unsigned int targetEUN; | |
263 | struct nftl_oob oob; | |
264 | int inplace = 1; | |
265 | size_t retlen; | |
266 | ||
267 | memset(BlockMap, 0xff, sizeof(BlockMap)); | |
268 | memset(BlockFreeFound, 0, sizeof(BlockFreeFound)); | |
269 | ||
270 | thisEUN = nftl->EUNtable[thisVUC]; | |
271 | ||
272 | if (thisEUN == BLOCK_NIL) { | |
273 | printk(KERN_WARNING "Trying to fold non-existent " | |
274 | "Virtual Unit Chain %d!\n", thisVUC); | |
275 | return BLOCK_NIL; | |
276 | } | |
277 | ||
278 | /* Scan to find the Erase Unit which holds the actual data for each | |
279 | 512-byte block within the Chain. | |
280 | */ | |
281 | silly = MAX_LOOPS; | |
282 | targetEUN = BLOCK_NIL; | |
283 | while (thisEUN <= nftl->lastEUN ) { | |
284 | unsigned int status, foldmark; | |
285 | ||
286 | targetEUN = thisEUN; | |
287 | for (block = 0; block < nftl->EraseSize / 512; block ++) { | |
288 | nftl_read_oob(mtd, (thisEUN * nftl->EraseSize) + | |
289 | (block * 512), 16 , &retlen, | |
290 | (char *)&oob); | |
291 | if (block == 2) { | |
292 | foldmark = oob.u.c.FoldMark | oob.u.c.FoldMark1; | |
293 | if (foldmark == FOLD_MARK_IN_PROGRESS) { | |
294 | DEBUG(MTD_DEBUG_LEVEL1, | |
295 | "Write Inhibited on EUN %d\n", thisEUN); | |
296 | inplace = 0; | |
297 | } else { | |
298 | /* There's no other reason not to do inplace, | |
299 | except ones that come later. So we don't need | |
300 | to preserve inplace */ | |
301 | inplace = 1; | |
302 | } | |
303 | } | |
304 | status = oob.b.Status | oob.b.Status1; | |
305 | BlockLastState[block] = status; | |
306 | ||
307 | switch(status) { | |
308 | case SECTOR_FREE: | |
309 | BlockFreeFound[block] = 1; | |
310 | break; | |
311 | ||
312 | case SECTOR_USED: | |
313 | if (!BlockFreeFound[block]) | |
314 | BlockMap[block] = thisEUN; | |
315 | else | |
316 | printk(KERN_WARNING | |
317 | "SECTOR_USED found after SECTOR_FREE " | |
318 | "in Virtual Unit Chain %d for block %d\n", | |
319 | thisVUC, block); | |
320 | break; | |
321 | case SECTOR_DELETED: | |
322 | if (!BlockFreeFound[block]) | |
323 | BlockMap[block] = BLOCK_NIL; | |
324 | else | |
325 | printk(KERN_WARNING | |
326 | "SECTOR_DELETED found after SECTOR_FREE " | |
327 | "in Virtual Unit Chain %d for block %d\n", | |
328 | thisVUC, block); | |
329 | break; | |
330 | ||
331 | case SECTOR_IGNORE: | |
332 | break; | |
333 | default: | |
334 | printk("Unknown status for block %d in EUN %d: %x\n", | |
335 | block, thisEUN, status); | |
336 | } | |
337 | } | |
338 | ||
339 | if (!silly--) { | |
340 | printk(KERN_WARNING "Infinite loop in Virtual Unit Chain 0x%x\n", | |
341 | thisVUC); | |
342 | return BLOCK_NIL; | |
343 | } | |
344 | ||
345 | thisEUN = nftl->ReplUnitTable[thisEUN]; | |
346 | } | |
347 | ||
348 | if (inplace) { | |
349 | /* We're being asked to be a fold-in-place. Check | |
350 | that all blocks which actually have data associated | |
351 | with them (i.e. BlockMap[block] != BLOCK_NIL) are | |
352 | either already present or SECTOR_FREE in the target | |
353 | block. If not, we're going to have to fold out-of-place | |
354 | anyway. | |
355 | */ | |
356 | for (block = 0; block < nftl->EraseSize / 512 ; block++) { | |
357 | if (BlockLastState[block] != SECTOR_FREE && | |
358 | BlockMap[block] != BLOCK_NIL && | |
359 | BlockMap[block] != targetEUN) { | |
360 | DEBUG(MTD_DEBUG_LEVEL1, "Setting inplace to 0. VUC %d, " | |
361 | "block %d was %x lastEUN, " | |
362 | "and is in EUN %d (%s) %d\n", | |
363 | thisVUC, block, BlockLastState[block], | |
364 | BlockMap[block], | |
365 | BlockMap[block]== targetEUN ? "==" : "!=", | |
366 | targetEUN); | |
367 | inplace = 0; | |
368 | break; | |
369 | } | |
370 | } | |
371 | ||
372 | if (pendingblock >= (thisVUC * (nftl->EraseSize / 512)) && | |
373 | pendingblock < ((thisVUC + 1)* (nftl->EraseSize / 512)) && | |
374 | BlockLastState[pendingblock - (thisVUC * (nftl->EraseSize / 512))] != | |
375 | SECTOR_FREE) { | |
376 | DEBUG(MTD_DEBUG_LEVEL1, "Pending write not free in EUN %d. " | |
377 | "Folding out of place.\n", targetEUN); | |
378 | inplace = 0; | |
379 | } | |
380 | } | |
381 | ||
382 | if (!inplace) { | |
383 | DEBUG(MTD_DEBUG_LEVEL1, "Cannot fold Virtual Unit Chain %d in place. " | |
384 | "Trying out-of-place\n", thisVUC); | |
385 | /* We need to find a targetEUN to fold into. */ | |
386 | targetEUN = NFTL_findfreeblock(nftl, 1); | |
387 | if (targetEUN == BLOCK_NIL) { | |
388 | /* Ouch. Now we're screwed. We need to do a | |
389 | fold-in-place of another chain to make room | |
390 | for this one. We need a better way of selecting | |
391 | which chain to fold, because makefreeblock will | |
392 | only ask us to fold the same one again. | |
393 | */ | |
394 | printk(KERN_WARNING | |
395 | "NFTL_findfreeblock(desperate) returns 0xffff.\n"); | |
396 | return BLOCK_NIL; | |
397 | } | |
398 | } else { | |
399 | /* We put a fold mark in the chain we are folding only if we | |
400 | fold in place to help the mount check code. If we do not fold in | |
401 | place, it is possible to find the valid chain by selecting the | |
402 | longer one */ | |
403 | oob.u.c.FoldMark = oob.u.c.FoldMark1 = cpu_to_le16(FOLD_MARK_IN_PROGRESS); | |
404 | oob.u.c.unused = 0xffffffff; | |
405 | nftl_write_oob(mtd, (nftl->EraseSize * targetEUN) + 2 * 512 + 8, | |
406 | 8, &retlen, (char *)&oob.u); | |
407 | } | |
408 | ||
409 | /* OK. We now know the location of every block in the Virtual Unit Chain, | |
410 | and the Erase Unit into which we are supposed to be copying. | |
411 | Go for it. | |
412 | */ | |
413 | DEBUG(MTD_DEBUG_LEVEL1,"Folding chain %d into unit %d\n", thisVUC, targetEUN); | |
414 | for (block = 0; block < nftl->EraseSize / 512 ; block++) { | |
415 | unsigned char movebuf[512]; | |
416 | int ret; | |
417 | ||
418 | /* If it's in the target EUN already, or if it's pending write, do nothing */ | |
419 | if (BlockMap[block] == targetEUN || | |
420 | (pendingblock == (thisVUC * (nftl->EraseSize / 512) + block))) { | |
421 | continue; | |
422 | } | |
423 | ||
424 | /* copy only in non free block (free blocks can only | |
425 | happen in case of media errors or deleted blocks) */ | |
426 | if (BlockMap[block] == BLOCK_NIL) | |
427 | continue; | |
428 | ||
429 | ret = mtd->read(mtd, (nftl->EraseSize * BlockMap[block]) + (block * 512), | |
430 | 512, &retlen, movebuf); | |
431 | if (ret < 0 && ret != -EUCLEAN) { | |
432 | ret = mtd->read(mtd, (nftl->EraseSize * BlockMap[block]) | |
433 | + (block * 512), 512, &retlen, | |
434 | movebuf); | |
435 | if (ret != -EIO) | |
436 | printk("Error went away on retry.\n"); | |
437 | } | |
438 | memset(&oob, 0xff, sizeof(struct nftl_oob)); | |
439 | oob.b.Status = oob.b.Status1 = SECTOR_USED; | |
440 | ||
441 | nftl_write(nftl->mbd.mtd, (nftl->EraseSize * targetEUN) + | |
442 | (block * 512), 512, &retlen, movebuf, (char *)&oob); | |
443 | } | |
444 | ||
445 | /* add the header so that it is now a valid chain */ | |
446 | oob.u.a.VirtUnitNum = oob.u.a.SpareVirtUnitNum = cpu_to_le16(thisVUC); | |
447 | oob.u.a.ReplUnitNum = oob.u.a.SpareReplUnitNum = BLOCK_NIL; | |
448 | ||
449 | nftl_write_oob(mtd, (nftl->EraseSize * targetEUN) + 8, | |
450 | 8, &retlen, (char *)&oob.u); | |
451 | ||
452 | /* OK. We've moved the whole lot into the new block. Now we have to free the original blocks. */ | |
453 | ||
454 | /* At this point, we have two different chains for this Virtual Unit, and no way to tell | |
455 | them apart. If we crash now, we get confused. However, both contain the same data, so we | |
456 | shouldn't actually lose data in this case. It's just that when we load up on a medium which | |
457 | has duplicate chains, we need to free one of the chains because it's not necessary any more. | |
458 | */ | |
459 | thisEUN = nftl->EUNtable[thisVUC]; | |
460 | DEBUG(MTD_DEBUG_LEVEL1,"Want to erase\n"); | |
461 | ||
462 | /* For each block in the old chain (except the targetEUN of course), | |
463 | free it and make it available for future use */ | |
464 | while (thisEUN <= nftl->lastEUN && thisEUN != targetEUN) { | |
465 | unsigned int EUNtmp; | |
466 | ||
467 | EUNtmp = nftl->ReplUnitTable[thisEUN]; | |
468 | ||
469 | if (NFTL_formatblock(nftl, thisEUN) < 0) { | |
470 | /* could not erase : mark block as reserved | |
471 | */ | |
472 | nftl->ReplUnitTable[thisEUN] = BLOCK_RESERVED; | |
473 | } else { | |
474 | /* correctly erased : mark it as free */ | |
475 | nftl->ReplUnitTable[thisEUN] = BLOCK_FREE; | |
476 | nftl->numfreeEUNs++; | |
477 | } | |
478 | thisEUN = EUNtmp; | |
479 | } | |
480 | ||
481 | /* Make this the new start of chain for thisVUC */ | |
482 | nftl->ReplUnitTable[targetEUN] = BLOCK_NIL; | |
483 | nftl->EUNtable[thisVUC] = targetEUN; | |
484 | ||
485 | return targetEUN; | |
486 | } | |
487 | ||
488 | static u16 NFTL_makefreeblock( struct NFTLrecord *nftl , unsigned pendingblock) | |
489 | { | |
490 | /* This is the part that needs some cleverness applied. | |
491 | For now, I'm doing the minimum applicable to actually | |
492 | get the thing to work. | |
493 | Wear-levelling and other clever stuff needs to be implemented | |
494 | and we also need to do some assessment of the results when | |
495 | the system loses power half-way through the routine. | |
496 | */ | |
497 | u16 LongestChain = 0; | |
498 | u16 ChainLength = 0, thislen; | |
499 | u16 chain, EUN; | |
500 | ||
501 | for (chain = 0; chain < le32_to_cpu(nftl->MediaHdr.FormattedSize) / nftl->EraseSize; chain++) { | |
502 | EUN = nftl->EUNtable[chain]; | |
503 | thislen = 0; | |
504 | ||
505 | while (EUN <= nftl->lastEUN) { | |
506 | thislen++; | |
507 | //printk("VUC %d reaches len %d with EUN %d\n", chain, thislen, EUN); | |
508 | EUN = nftl->ReplUnitTable[EUN] & 0x7fff; | |
509 | if (thislen > 0xff00) { | |
510 | printk("Endless loop in Virtual Chain %d: Unit %x\n", | |
511 | chain, EUN); | |
512 | } | |
513 | if (thislen > 0xff10) { | |
514 | /* Actually, don't return failure. Just ignore this chain and | |
515 | get on with it. */ | |
516 | thislen = 0; | |
517 | break; | |
518 | } | |
519 | } | |
520 | ||
521 | if (thislen > ChainLength) { | |
522 | //printk("New longest chain is %d with length %d\n", chain, thislen); | |
523 | ChainLength = thislen; | |
524 | LongestChain = chain; | |
525 | } | |
526 | } | |
527 | ||
528 | if (ChainLength < 2) { | |
529 | printk(KERN_WARNING "No Virtual Unit Chains available for folding. " | |
530 | "Failing request\n"); | |
531 | return BLOCK_NIL; | |
532 | } | |
533 | ||
534 | return NFTL_foldchain (nftl, LongestChain, pendingblock); | |
535 | } | |
536 | ||
537 | /* NFTL_findwriteunit: Return the unit number into which we can write | |
538 | for this block. Make it available if it isn't already | |
539 | */ | |
540 | static inline u16 NFTL_findwriteunit(struct NFTLrecord *nftl, unsigned block) | |
541 | { | |
542 | u16 lastEUN; | |
543 | u16 thisVUC = block / (nftl->EraseSize / 512); | |
544 | struct mtd_info *mtd = nftl->mbd.mtd; | |
545 | unsigned int writeEUN; | |
546 | unsigned long blockofs = (block * 512) & (nftl->EraseSize -1); | |
547 | size_t retlen; | |
548 | int silly, silly2 = 3; | |
549 | struct nftl_oob oob; | |
550 | ||
551 | do { | |
552 | /* Scan the media to find a unit in the VUC which has | |
553 | a free space for the block in question. | |
554 | */ | |
555 | ||
556 | /* This condition catches the 0x[7f]fff cases, as well as | |
557 | being a sanity check for past-end-of-media access | |
558 | */ | |
559 | lastEUN = BLOCK_NIL; | |
560 | writeEUN = nftl->EUNtable[thisVUC]; | |
561 | silly = MAX_LOOPS; | |
562 | while (writeEUN <= nftl->lastEUN) { | |
563 | struct nftl_bci bci; | |
564 | size_t retlen; | |
565 | unsigned int status; | |
566 | ||
567 | lastEUN = writeEUN; | |
568 | ||
569 | nftl_read_oob(mtd, | |
570 | (writeEUN * nftl->EraseSize) + blockofs, | |
571 | 8, &retlen, (char *)&bci); | |
572 | ||
573 | DEBUG(MTD_DEBUG_LEVEL2, "Status of block %d in EUN %d is %x\n", | |
574 | block , writeEUN, le16_to_cpu(bci.Status)); | |
575 | ||
576 | status = bci.Status | bci.Status1; | |
577 | switch(status) { | |
578 | case SECTOR_FREE: | |
579 | return writeEUN; | |
580 | ||
581 | case SECTOR_DELETED: | |
582 | case SECTOR_USED: | |
583 | case SECTOR_IGNORE: | |
584 | break; | |
585 | default: | |
586 | // Invalid block. Don't use it any more. Must implement. | |
587 | break; | |
588 | } | |
589 | ||
590 | if (!silly--) { | |
591 | printk(KERN_WARNING | |
592 | "Infinite loop in Virtual Unit Chain 0x%x\n", | |
593 | thisVUC); | |
594 | return BLOCK_NIL; | |
595 | } | |
596 | ||
597 | /* Skip to next block in chain */ | |
598 | writeEUN = nftl->ReplUnitTable[writeEUN]; | |
599 | } | |
600 | ||
601 | /* OK. We didn't find one in the existing chain, or there | |
602 | is no existing chain. */ | |
603 | ||
604 | /* Try to find an already-free block */ | |
605 | writeEUN = NFTL_findfreeblock(nftl, 0); | |
606 | ||
607 | if (writeEUN == BLOCK_NIL) { | |
608 | /* That didn't work - there were no free blocks just | |
609 | waiting to be picked up. We're going to have to fold | |
610 | a chain to make room. | |
611 | */ | |
612 | ||
613 | /* First remember the start of this chain */ | |
614 | //u16 startEUN = nftl->EUNtable[thisVUC]; | |
615 | ||
616 | //printk("Write to VirtualUnitChain %d, calling makefreeblock()\n", thisVUC); | |
617 | writeEUN = NFTL_makefreeblock(nftl, BLOCK_NIL); | |
618 | ||
619 | if (writeEUN == BLOCK_NIL) { | |
620 | /* OK, we accept that the above comment is | |
621 | lying - there may have been free blocks | |
622 | last time we called NFTL_findfreeblock(), | |
623 | but they are reserved for when we're | |
624 | desperate. Well, now we're desperate. | |
625 | */ | |
626 | DEBUG(MTD_DEBUG_LEVEL1, "Using desperate==1 to find free EUN to accommodate write to VUC %d\n", thisVUC); | |
627 | writeEUN = NFTL_findfreeblock(nftl, 1); | |
628 | } | |
629 | if (writeEUN == BLOCK_NIL) { | |
630 | /* Ouch. This should never happen - we should | |
631 | always be able to make some room somehow. | |
632 | If we get here, we've allocated more storage | |
633 | space than actual media, or our makefreeblock | |
634 | routine is missing something. | |
635 | */ | |
636 | printk(KERN_WARNING "Cannot make free space.\n"); | |
637 | return BLOCK_NIL; | |
638 | } | |
639 | //printk("Restarting scan\n"); | |
640 | lastEUN = BLOCK_NIL; | |
641 | continue; | |
642 | } | |
643 | ||
644 | /* We've found a free block. Insert it into the chain. */ | |
645 | ||
646 | if (lastEUN != BLOCK_NIL) { | |
647 | thisVUC |= 0x8000; /* It's a replacement block */ | |
648 | } else { | |
649 | /* The first block in a new chain */ | |
650 | nftl->EUNtable[thisVUC] = writeEUN; | |
651 | } | |
652 | ||
653 | /* set up the actual EUN we're writing into */ | |
654 | /* Both in our cache... */ | |
655 | nftl->ReplUnitTable[writeEUN] = BLOCK_NIL; | |
656 | ||
657 | /* ... and on the flash itself */ | |
658 | nftl_read_oob(mtd, writeEUN * nftl->EraseSize + 8, 8, | |
659 | &retlen, (char *)&oob.u); | |
660 | ||
661 | oob.u.a.VirtUnitNum = oob.u.a.SpareVirtUnitNum = cpu_to_le16(thisVUC); | |
662 | ||
663 | nftl_write_oob(mtd, writeEUN * nftl->EraseSize + 8, 8, | |
664 | &retlen, (char *)&oob.u); | |
665 | ||
666 | /* we link the new block to the chain only after the | |
667 | block is ready. It avoids the case where the chain | |
668 | could point to a free block */ | |
669 | if (lastEUN != BLOCK_NIL) { | |
670 | /* Both in our cache... */ | |
671 | nftl->ReplUnitTable[lastEUN] = writeEUN; | |
672 | /* ... and on the flash itself */ | |
673 | nftl_read_oob(mtd, (lastEUN * nftl->EraseSize) + 8, | |
674 | 8, &retlen, (char *)&oob.u); | |
675 | ||
676 | oob.u.a.ReplUnitNum = oob.u.a.SpareReplUnitNum | |
677 | = cpu_to_le16(writeEUN); | |
678 | ||
679 | nftl_write_oob(mtd, (lastEUN * nftl->EraseSize) + 8, | |
680 | 8, &retlen, (char *)&oob.u); | |
681 | } | |
682 | ||
683 | return writeEUN; | |
684 | ||
685 | } while (silly2--); | |
686 | ||
687 | printk(KERN_WARNING "Error folding to make room for Virtual Unit Chain 0x%x\n", | |
688 | thisVUC); | |
689 | return BLOCK_NIL; | |
690 | } | |
691 | ||
692 | static int nftl_writeblock(struct mtd_blktrans_dev *mbd, unsigned long block, | |
693 | char *buffer) | |
694 | { | |
695 | struct NFTLrecord *nftl = (void *)mbd; | |
696 | u16 writeEUN; | |
697 | unsigned long blockofs = (block * 512) & (nftl->EraseSize - 1); | |
698 | size_t retlen; | |
699 | struct nftl_oob oob; | |
700 | ||
701 | writeEUN = NFTL_findwriteunit(nftl, block); | |
702 | ||
703 | if (writeEUN == BLOCK_NIL) { | |
704 | printk(KERN_WARNING | |
705 | "NFTL_writeblock(): Cannot find block to write to\n"); | |
706 | /* If we _still_ haven't got a block to use, we're screwed */ | |
707 | return 1; | |
708 | } | |
709 | ||
710 | memset(&oob, 0xff, sizeof(struct nftl_oob)); | |
711 | oob.b.Status = oob.b.Status1 = SECTOR_USED; | |
712 | ||
713 | nftl_write(nftl->mbd.mtd, (writeEUN * nftl->EraseSize) + blockofs, | |
714 | 512, &retlen, (char *)buffer, (char *)&oob); | |
715 | return 0; | |
716 | } | |
717 | #endif /* CONFIG_NFTL_RW */ | |
718 | ||
719 | static int nftl_readblock(struct mtd_blktrans_dev *mbd, unsigned long block, | |
720 | char *buffer) | |
721 | { | |
722 | struct NFTLrecord *nftl = (void *)mbd; | |
723 | struct mtd_info *mtd = nftl->mbd.mtd; | |
724 | u16 lastgoodEUN; | |
725 | u16 thisEUN = nftl->EUNtable[block / (nftl->EraseSize / 512)]; | |
726 | unsigned long blockofs = (block * 512) & (nftl->EraseSize - 1); | |
727 | unsigned int status; | |
728 | int silly = MAX_LOOPS; | |
729 | size_t retlen; | |
730 | struct nftl_bci bci; | |
731 | ||
732 | lastgoodEUN = BLOCK_NIL; | |
733 | ||
734 | if (thisEUN != BLOCK_NIL) { | |
735 | while (thisEUN < nftl->nb_blocks) { | |
736 | if (nftl_read_oob(mtd, (thisEUN * nftl->EraseSize) + | |
737 | blockofs, 8, &retlen, | |
738 | (char *)&bci) < 0) | |
739 | status = SECTOR_IGNORE; | |
740 | else | |
741 | status = bci.Status | bci.Status1; | |
742 | ||
743 | switch (status) { | |
744 | case SECTOR_FREE: | |
745 | /* no modification of a sector should follow a free sector */ | |
746 | goto the_end; | |
747 | case SECTOR_DELETED: | |
748 | lastgoodEUN = BLOCK_NIL; | |
749 | break; | |
750 | case SECTOR_USED: | |
751 | lastgoodEUN = thisEUN; | |
752 | break; | |
753 | case SECTOR_IGNORE: | |
754 | break; | |
755 | default: | |
756 | printk("Unknown status for block %ld in EUN %d: %x\n", | |
757 | block, thisEUN, status); | |
758 | break; | |
759 | } | |
760 | ||
761 | if (!silly--) { | |
762 | printk(KERN_WARNING "Infinite loop in Virtual Unit Chain 0x%lx\n", | |
763 | block / (nftl->EraseSize / 512)); | |
764 | return 1; | |
765 | } | |
766 | thisEUN = nftl->ReplUnitTable[thisEUN]; | |
767 | } | |
768 | } | |
769 | ||
770 | the_end: | |
771 | if (lastgoodEUN == BLOCK_NIL) { | |
772 | /* the requested block is not on the media, return all 0x00 */ | |
773 | memset(buffer, 0, 512); | |
774 | } else { | |
775 | loff_t ptr = (lastgoodEUN * nftl->EraseSize) + blockofs; | |
776 | size_t retlen; | |
777 | int res = mtd->read(mtd, ptr, 512, &retlen, buffer); | |
778 | ||
779 | if (res < 0 && res != -EUCLEAN) | |
780 | return -EIO; | |
781 | } | |
782 | return 0; | |
783 | } | |
784 | ||
785 | static int nftl_getgeo(struct mtd_blktrans_dev *dev, struct hd_geometry *geo) | |
786 | { | |
787 | struct NFTLrecord *nftl = (void *)dev; | |
788 | ||
789 | geo->heads = nftl->heads; | |
790 | geo->sectors = nftl->sectors; | |
791 | geo->cylinders = nftl->cylinders; | |
792 | ||
793 | return 0; | |
794 | } | |
795 | ||
796 | /**************************************************************************** | |
797 | * | |
798 | * Module stuff | |
799 | * | |
800 | ****************************************************************************/ | |
801 | ||
802 | ||
803 | static struct mtd_blktrans_ops nftl_tr = { | |
804 | .name = "nftl", | |
805 | .major = NFTL_MAJOR, | |
806 | .part_bits = NFTL_PARTN_BITS, | |
807 | .blksize = 512, | |
808 | .getgeo = nftl_getgeo, | |
809 | .readsect = nftl_readblock, | |
810 | #ifdef CONFIG_NFTL_RW | |
811 | .writesect = nftl_writeblock, | |
812 | #endif | |
813 | .add_mtd = nftl_add_mtd, | |
814 | .remove_dev = nftl_remove_dev, | |
815 | .owner = THIS_MODULE, | |
816 | }; | |
817 | ||
818 | static int __init init_nftl(void) | |
819 | { | |
820 | return register_mtd_blktrans(&nftl_tr); | |
821 | } | |
822 | ||
823 | static void __exit cleanup_nftl(void) | |
824 | { | |
825 | deregister_mtd_blktrans(&nftl_tr); | |
826 | } | |
827 | ||
828 | module_init(init_nftl); | |
829 | module_exit(cleanup_nftl); | |
830 | ||
831 | MODULE_LICENSE("GPL"); | |
832 | MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>, Fabrice Bellard <fabrice.bellard@netgem.com> et al."); | |
833 | MODULE_DESCRIPTION("Support code for NAND Flash Translation Layer, used on M-Systems DiskOnChip 2000 and Millennium"); | |
834 | MODULE_ALIAS_BLOCKDEV_MAJOR(NFTL_MAJOR); |