1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * Linux driver for NAND Flash Translation Layer |
4 | * |
5 | * Copyright © 1999 Machine Vision Holdings, Inc. |
6 | * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org> |
7 | */ |
8 | |
9 | #define PRERELEASE |
10 | |
11 | #include <linux/kernel.h> |
12 | #include <linux/module.h> |
13 | #include <asm/errno.h> |
14 | #include <asm/io.h> |
15 | #include <linux/uaccess.h> |
16 | #include <linux/delay.h> |
17 | #include <linux/slab.h> |
18 | #include <linux/init.h> |
19 | #include <linux/hdreg.h> |
20 | #include <linux/blkdev.h> |
21 | |
22 | #include <linux/kmod.h> |
23 | #include <linux/mtd/mtd.h> |
24 | #include <linux/mtd/rawnand.h> |
25 | #include <linux/mtd/nftl.h> |
26 | #include <linux/mtd/blktrans.h> |
27 | |
28 | /* maximum number of loops while examining next block, to have a |
29 | chance to detect consistency problems (they should never happen |
30 | because of the checks done in the mounting */ |
31 | |
32 | #define MAX_LOOPS 10000 |
33 | |
34 | |
35 | static void nftl_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd) |
36 | { |
37 | struct NFTLrecord *nftl; |
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(p: mtd->name, q: "DiskOnChip" , size: 10)) |
44 | return; |
45 | |
46 | pr_debug("NFTL: add_mtd for %s\n" , mtd->name); |
47 | |
48 | nftl = kzalloc(size: sizeof(struct NFTLrecord), GFP_KERNEL); |
49 | |
50 | if (!nftl) |
51 | return; |
52 | |
53 | nftl->mbd.mtd = mtd; |
54 | nftl->mbd.devnum = -1; |
55 | |
56 | nftl->mbd.tr = tr; |
57 | |
58 | if (NFTL_mount(s: nftl) < 0) { |
59 | printk(KERN_WARNING "NFTL: could not mount device\n" ); |
60 | kfree(objp: nftl); |
61 | return; |
62 | } |
63 | |
64 | /* OK, it's a new one. Set up all the data structures. */ |
65 | |
66 | /* Calculate geometry */ |
67 | nftl->cylinders = 1024; |
68 | nftl->heads = 16; |
69 | |
70 | temp = nftl->cylinders * nftl->heads; |
71 | nftl->sectors = nftl->mbd.size / temp; |
72 | if (nftl->mbd.size % temp) { |
73 | nftl->sectors++; |
74 | temp = nftl->cylinders * nftl->sectors; |
75 | nftl->heads = nftl->mbd.size / temp; |
76 | |
77 | if (nftl->mbd.size % temp) { |
78 | nftl->heads++; |
79 | temp = nftl->heads * nftl->sectors; |
80 | nftl->cylinders = nftl->mbd.size / temp; |
81 | } |
82 | } |
83 | |
84 | if (nftl->mbd.size != nftl->heads * nftl->cylinders * nftl->sectors) { |
85 | /* |
86 | Oh no we don't have |
87 | mbd.size == heads * cylinders * sectors |
88 | */ |
89 | printk(KERN_WARNING "NFTL: cannot calculate a geometry to " |
90 | "match size of 0x%lx.\n" , nftl->mbd.size); |
91 | printk(KERN_WARNING "NFTL: using C:%d H:%d S:%d " |
92 | "(== 0x%lx sects)\n" , |
93 | nftl->cylinders, nftl->heads , nftl->sectors, |
94 | (long)nftl->cylinders * (long)nftl->heads * |
95 | (long)nftl->sectors ); |
96 | } |
97 | |
98 | if (add_mtd_blktrans_dev(dev: &nftl->mbd)) { |
99 | kfree(objp: nftl->ReplUnitTable); |
100 | kfree(objp: nftl->EUNtable); |
101 | kfree(objp: nftl); |
102 | return; |
103 | } |
104 | #ifdef PSYCHO_DEBUG |
105 | printk(KERN_INFO "NFTL: Found new nftl%c\n" , nftl->mbd.devnum + 'a'); |
106 | #endif |
107 | } |
108 | |
109 | static void nftl_remove_dev(struct mtd_blktrans_dev *dev) |
110 | { |
111 | struct NFTLrecord *nftl = (void *)dev; |
112 | |
113 | pr_debug("NFTL: remove_dev (i=%d)\n" , dev->devnum); |
114 | |
115 | del_mtd_blktrans_dev(dev); |
116 | kfree(objp: nftl->ReplUnitTable); |
117 | kfree(objp: nftl->EUNtable); |
118 | } |
119 | |
120 | /* |
121 | * Read oob data from flash |
122 | */ |
123 | int nftl_read_oob(struct mtd_info *mtd, loff_t offs, size_t len, |
124 | size_t *retlen, uint8_t *buf) |
125 | { |
126 | loff_t mask = mtd->writesize - 1; |
127 | struct mtd_oob_ops ops = { }; |
128 | int res; |
129 | |
130 | ops.mode = MTD_OPS_PLACE_OOB; |
131 | ops.ooboffs = offs & mask; |
132 | ops.ooblen = len; |
133 | ops.oobbuf = buf; |
134 | ops.datbuf = NULL; |
135 | |
136 | res = mtd_read_oob(mtd, from: offs & ~mask, ops: &ops); |
137 | *retlen = ops.oobretlen; |
138 | return res; |
139 | } |
140 | |
141 | /* |
142 | * Write oob data to flash |
143 | */ |
144 | int nftl_write_oob(struct mtd_info *mtd, loff_t offs, size_t len, |
145 | size_t *retlen, uint8_t *buf) |
146 | { |
147 | loff_t mask = mtd->writesize - 1; |
148 | struct mtd_oob_ops ops = { }; |
149 | int res; |
150 | |
151 | ops.mode = MTD_OPS_PLACE_OOB; |
152 | ops.ooboffs = offs & mask; |
153 | ops.ooblen = len; |
154 | ops.oobbuf = buf; |
155 | ops.datbuf = NULL; |
156 | |
157 | res = mtd_write_oob(mtd, to: offs & ~mask, ops: &ops); |
158 | *retlen = ops.oobretlen; |
159 | return res; |
160 | } |
161 | |
162 | #ifdef CONFIG_NFTL_RW |
163 | |
164 | /* |
165 | * Write data and oob to flash |
166 | */ |
167 | static int nftl_write(struct mtd_info *mtd, loff_t offs, size_t len, |
168 | size_t *retlen, uint8_t *buf, uint8_t *oob) |
169 | { |
170 | loff_t mask = mtd->writesize - 1; |
171 | struct mtd_oob_ops ops = { }; |
172 | int res; |
173 | |
174 | ops.mode = MTD_OPS_PLACE_OOB; |
175 | ops.ooboffs = offs & mask; |
176 | ops.ooblen = mtd->oobsize; |
177 | ops.oobbuf = oob; |
178 | ops.datbuf = buf; |
179 | ops.len = len; |
180 | |
181 | res = mtd_write_oob(mtd, to: offs & ~mask, ops: &ops); |
182 | *retlen = ops.retlen; |
183 | return res; |
184 | } |
185 | |
186 | /* Actual NFTL access routines */ |
187 | /* NFTL_findfreeblock: Find a free Erase Unit on the NFTL partition. This function is used |
188 | * when the give Virtual Unit Chain |
189 | */ |
190 | static u16 NFTL_findfreeblock(struct NFTLrecord *nftl, int desperate ) |
191 | { |
192 | /* For a given Virtual Unit Chain: find or create a free block and |
193 | add it to the chain */ |
194 | /* We're passed the number of the last EUN in the chain, to save us from |
195 | having to look it up again */ |
196 | u16 pot = nftl->LastFreeEUN; |
197 | int silly = nftl->nb_blocks; |
198 | |
199 | /* Normally, we force a fold to happen before we run out of free blocks completely */ |
200 | if (!desperate && nftl->numfreeEUNs < 2) { |
201 | pr_debug("NFTL_findfreeblock: there are too few free EUNs\n" ); |
202 | return BLOCK_NIL; |
203 | } |
204 | |
205 | /* Scan for a free block */ |
206 | do { |
207 | if (nftl->ReplUnitTable[pot] == BLOCK_FREE) { |
208 | nftl->LastFreeEUN = pot; |
209 | nftl->numfreeEUNs--; |
210 | return pot; |
211 | } |
212 | |
213 | /* This will probably point to the MediaHdr unit itself, |
214 | right at the beginning of the partition. But that unit |
215 | (and the backup unit too) should have the UCI set |
216 | up so that it's not selected for overwriting */ |
217 | if (++pot > nftl->lastEUN) |
218 | pot = le16_to_cpu(nftl->MediaHdr.FirstPhysicalEUN); |
219 | |
220 | if (!silly--) { |
221 | printk("Argh! No free blocks found! LastFreeEUN = %d, " |
222 | "FirstEUN = %d\n" , nftl->LastFreeEUN, |
223 | le16_to_cpu(nftl->MediaHdr.FirstPhysicalEUN)); |
224 | return BLOCK_NIL; |
225 | } |
226 | } while (pot != nftl->LastFreeEUN); |
227 | |
228 | return BLOCK_NIL; |
229 | } |
230 | |
231 | static u16 NFTL_foldchain (struct NFTLrecord *nftl, unsigned thisVUC, unsigned pendingblock ) |
232 | { |
233 | struct mtd_info *mtd = nftl->mbd.mtd; |
234 | u16 BlockMap[MAX_SECTORS_PER_UNIT]; |
235 | unsigned char BlockLastState[MAX_SECTORS_PER_UNIT]; |
236 | unsigned char BlockFreeFound[MAX_SECTORS_PER_UNIT]; |
237 | unsigned int thisEUN; |
238 | int block; |
239 | int silly; |
240 | unsigned int targetEUN; |
241 | struct nftl_oob oob; |
242 | int inplace = 1; |
243 | size_t retlen; |
244 | |
245 | memset(BlockMap, 0xff, sizeof(BlockMap)); |
246 | memset(BlockFreeFound, 0, sizeof(BlockFreeFound)); |
247 | |
248 | thisEUN = nftl->EUNtable[thisVUC]; |
249 | |
250 | if (thisEUN == BLOCK_NIL) { |
251 | printk(KERN_WARNING "Trying to fold non-existent " |
252 | "Virtual Unit Chain %d!\n" , thisVUC); |
253 | return BLOCK_NIL; |
254 | } |
255 | |
256 | /* Scan to find the Erase Unit which holds the actual data for each |
257 | 512-byte block within the Chain. |
258 | */ |
259 | silly = MAX_LOOPS; |
260 | targetEUN = BLOCK_NIL; |
261 | while (thisEUN <= nftl->lastEUN ) { |
262 | unsigned int status, foldmark; |
263 | |
264 | targetEUN = thisEUN; |
265 | for (block = 0; block < nftl->EraseSize / 512; block ++) { |
266 | nftl_read_oob(mtd, offs: (thisEUN * nftl->EraseSize) + |
267 | (block * 512), len: 16 , retlen: &retlen, |
268 | buf: (char *)&oob); |
269 | if (block == 2) { |
270 | foldmark = oob.u.c.FoldMark | oob.u.c.FoldMark1; |
271 | if (foldmark == FOLD_MARK_IN_PROGRESS) { |
272 | pr_debug("Write Inhibited on EUN %d\n" , thisEUN); |
273 | inplace = 0; |
274 | } else { |
275 | /* There's no other reason not to do inplace, |
276 | except ones that come later. So we don't need |
277 | to preserve inplace */ |
278 | inplace = 1; |
279 | } |
280 | } |
281 | status = oob.b.Status | oob.b.Status1; |
282 | BlockLastState[block] = status; |
283 | |
284 | switch(status) { |
285 | case SECTOR_FREE: |
286 | BlockFreeFound[block] = 1; |
287 | break; |
288 | |
289 | case SECTOR_USED: |
290 | if (!BlockFreeFound[block]) |
291 | BlockMap[block] = thisEUN; |
292 | else |
293 | printk(KERN_WARNING |
294 | "SECTOR_USED found after SECTOR_FREE " |
295 | "in Virtual Unit Chain %d for block %d\n" , |
296 | thisVUC, block); |
297 | break; |
298 | case SECTOR_DELETED: |
299 | if (!BlockFreeFound[block]) |
300 | BlockMap[block] = BLOCK_NIL; |
301 | else |
302 | printk(KERN_WARNING |
303 | "SECTOR_DELETED found after SECTOR_FREE " |
304 | "in Virtual Unit Chain %d for block %d\n" , |
305 | thisVUC, block); |
306 | break; |
307 | |
308 | case SECTOR_IGNORE: |
309 | break; |
310 | default: |
311 | printk("Unknown status for block %d in EUN %d: %x\n" , |
312 | block, thisEUN, status); |
313 | } |
314 | } |
315 | |
316 | if (!silly--) { |
317 | printk(KERN_WARNING "Infinite loop in Virtual Unit Chain 0x%x\n" , |
318 | thisVUC); |
319 | return BLOCK_NIL; |
320 | } |
321 | |
322 | thisEUN = nftl->ReplUnitTable[thisEUN]; |
323 | } |
324 | |
325 | if (inplace) { |
326 | /* We're being asked to be a fold-in-place. Check |
327 | that all blocks which actually have data associated |
328 | with them (i.e. BlockMap[block] != BLOCK_NIL) are |
329 | either already present or SECTOR_FREE in the target |
330 | block. If not, we're going to have to fold out-of-place |
331 | anyway. |
332 | */ |
333 | for (block = 0; block < nftl->EraseSize / 512 ; block++) { |
334 | if (BlockLastState[block] != SECTOR_FREE && |
335 | BlockMap[block] != BLOCK_NIL && |
336 | BlockMap[block] != targetEUN) { |
337 | pr_debug("Setting inplace to 0. VUC %d, " |
338 | "block %d was %x lastEUN, " |
339 | "and is in EUN %d (%s) %d\n" , |
340 | thisVUC, block, BlockLastState[block], |
341 | BlockMap[block], |
342 | BlockMap[block]== targetEUN ? "==" : "!=" , |
343 | targetEUN); |
344 | inplace = 0; |
345 | break; |
346 | } |
347 | } |
348 | |
349 | if (pendingblock >= (thisVUC * (nftl->EraseSize / 512)) && |
350 | pendingblock < ((thisVUC + 1)* (nftl->EraseSize / 512)) && |
351 | BlockLastState[pendingblock - (thisVUC * (nftl->EraseSize / 512))] != |
352 | SECTOR_FREE) { |
353 | pr_debug("Pending write not free in EUN %d. " |
354 | "Folding out of place.\n" , targetEUN); |
355 | inplace = 0; |
356 | } |
357 | } |
358 | |
359 | if (!inplace) { |
360 | pr_debug("Cannot fold Virtual Unit Chain %d in place. " |
361 | "Trying out-of-place\n" , thisVUC); |
362 | /* We need to find a targetEUN to fold into. */ |
363 | targetEUN = NFTL_findfreeblock(nftl, desperate: 1); |
364 | if (targetEUN == BLOCK_NIL) { |
365 | /* Ouch. Now we're screwed. We need to do a |
366 | fold-in-place of another chain to make room |
367 | for this one. We need a better way of selecting |
368 | which chain to fold, because makefreeblock will |
369 | only ask us to fold the same one again. |
370 | */ |
371 | printk(KERN_WARNING |
372 | "NFTL_findfreeblock(desperate) returns 0xffff.\n" ); |
373 | return BLOCK_NIL; |
374 | } |
375 | } else { |
376 | /* We put a fold mark in the chain we are folding only if we |
377 | fold in place to help the mount check code. If we do not fold in |
378 | place, it is possible to find the valid chain by selecting the |
379 | longer one */ |
380 | oob.u.c.FoldMark = oob.u.c.FoldMark1 = cpu_to_le16(FOLD_MARK_IN_PROGRESS); |
381 | oob.u.c.unused = 0xffffffff; |
382 | nftl_write_oob(mtd, offs: (nftl->EraseSize * targetEUN) + 2 * 512 + 8, |
383 | len: 8, retlen: &retlen, buf: (char *)&oob.u); |
384 | } |
385 | |
386 | /* OK. We now know the location of every block in the Virtual Unit Chain, |
387 | and the Erase Unit into which we are supposed to be copying. |
388 | Go for it. |
389 | */ |
390 | pr_debug("Folding chain %d into unit %d\n" , thisVUC, targetEUN); |
391 | for (block = 0; block < nftl->EraseSize / 512 ; block++) { |
392 | unsigned char movebuf[512]; |
393 | int ret; |
394 | |
395 | /* If it's in the target EUN already, or if it's pending write, do nothing */ |
396 | if (BlockMap[block] == targetEUN || |
397 | (pendingblock == (thisVUC * (nftl->EraseSize / 512) + block))) { |
398 | continue; |
399 | } |
400 | |
401 | /* copy only in non free block (free blocks can only |
402 | happen in case of media errors or deleted blocks) */ |
403 | if (BlockMap[block] == BLOCK_NIL) |
404 | continue; |
405 | |
406 | ret = mtd_read(mtd, |
407 | from: (nftl->EraseSize * BlockMap[block]) + (block * 512), |
408 | len: 512, |
409 | retlen: &retlen, |
410 | buf: movebuf); |
411 | if (ret < 0 && !mtd_is_bitflip(err: ret)) { |
412 | ret = mtd_read(mtd, |
413 | from: (nftl->EraseSize * BlockMap[block]) + (block * 512), |
414 | len: 512, |
415 | retlen: &retlen, |
416 | buf: movebuf); |
417 | if (ret != -EIO) |
418 | printk("Error went away on retry.\n" ); |
419 | } |
420 | memset(&oob, 0xff, sizeof(struct nftl_oob)); |
421 | oob.b.Status = oob.b.Status1 = SECTOR_USED; |
422 | |
423 | nftl_write(mtd: nftl->mbd.mtd, offs: (nftl->EraseSize * targetEUN) + |
424 | (block * 512), len: 512, retlen: &retlen, buf: movebuf, oob: (char *)&oob); |
425 | } |
426 | |
427 | /* add the header so that it is now a valid chain */ |
428 | oob.u.a.VirtUnitNum = oob.u.a.SpareVirtUnitNum = cpu_to_le16(thisVUC); |
429 | oob.u.a.ReplUnitNum = oob.u.a.SpareReplUnitNum = BLOCK_NIL; |
430 | |
431 | nftl_write_oob(mtd, offs: (nftl->EraseSize * targetEUN) + 8, |
432 | len: 8, retlen: &retlen, buf: (char *)&oob.u); |
433 | |
434 | /* OK. We've moved the whole lot into the new block. Now we have to free the original blocks. */ |
435 | |
436 | /* At this point, we have two different chains for this Virtual Unit, and no way to tell |
437 | them apart. If we crash now, we get confused. However, both contain the same data, so we |
438 | shouldn't actually lose data in this case. It's just that when we load up on a medium which |
439 | has duplicate chains, we need to free one of the chains because it's not necessary any more. |
440 | */ |
441 | thisEUN = nftl->EUNtable[thisVUC]; |
442 | pr_debug("Want to erase\n" ); |
443 | |
444 | /* For each block in the old chain (except the targetEUN of course), |
445 | free it and make it available for future use */ |
446 | while (thisEUN <= nftl->lastEUN && thisEUN != targetEUN) { |
447 | unsigned int EUNtmp; |
448 | |
449 | EUNtmp = nftl->ReplUnitTable[thisEUN]; |
450 | |
451 | if (NFTL_formatblock(s: nftl, block: thisEUN) < 0) { |
452 | /* could not erase : mark block as reserved |
453 | */ |
454 | nftl->ReplUnitTable[thisEUN] = BLOCK_RESERVED; |
455 | } else { |
456 | /* correctly erased : mark it as free */ |
457 | nftl->ReplUnitTable[thisEUN] = BLOCK_FREE; |
458 | nftl->numfreeEUNs++; |
459 | } |
460 | thisEUN = EUNtmp; |
461 | } |
462 | |
463 | /* Make this the new start of chain for thisVUC */ |
464 | nftl->ReplUnitTable[targetEUN] = BLOCK_NIL; |
465 | nftl->EUNtable[thisVUC] = targetEUN; |
466 | |
467 | return targetEUN; |
468 | } |
469 | |
470 | static u16 NFTL_makefreeblock( struct NFTLrecord *nftl , unsigned pendingblock) |
471 | { |
472 | /* This is the part that needs some cleverness applied. |
473 | For now, I'm doing the minimum applicable to actually |
474 | get the thing to work. |
475 | Wear-levelling and other clever stuff needs to be implemented |
476 | and we also need to do some assessment of the results when |
477 | the system loses power half-way through the routine. |
478 | */ |
479 | u16 LongestChain = 0; |
480 | u16 ChainLength = 0, thislen; |
481 | u16 chain, EUN; |
482 | |
483 | for (chain = 0; chain < le32_to_cpu(nftl->MediaHdr.FormattedSize) / nftl->EraseSize; chain++) { |
484 | EUN = nftl->EUNtable[chain]; |
485 | thislen = 0; |
486 | |
487 | while (EUN <= nftl->lastEUN) { |
488 | thislen++; |
489 | //printk("VUC %d reaches len %d with EUN %d\n", chain, thislen, EUN); |
490 | EUN = nftl->ReplUnitTable[EUN] & 0x7fff; |
491 | if (thislen > 0xff00) { |
492 | printk("Endless loop in Virtual Chain %d: Unit %x\n" , |
493 | chain, EUN); |
494 | } |
495 | if (thislen > 0xff10) { |
496 | /* Actually, don't return failure. Just ignore this chain and |
497 | get on with it. */ |
498 | thislen = 0; |
499 | break; |
500 | } |
501 | } |
502 | |
503 | if (thislen > ChainLength) { |
504 | //printk("New longest chain is %d with length %d\n", chain, thislen); |
505 | ChainLength = thislen; |
506 | LongestChain = chain; |
507 | } |
508 | } |
509 | |
510 | if (ChainLength < 2) { |
511 | printk(KERN_WARNING "No Virtual Unit Chains available for folding. " |
512 | "Failing request\n" ); |
513 | return BLOCK_NIL; |
514 | } |
515 | |
516 | return NFTL_foldchain (nftl, thisVUC: LongestChain, pendingblock); |
517 | } |
518 | |
519 | /* NFTL_findwriteunit: Return the unit number into which we can write |
520 | for this block. Make it available if it isn't already |
521 | */ |
522 | static inline u16 NFTL_findwriteunit(struct NFTLrecord *nftl, unsigned block) |
523 | { |
524 | u16 lastEUN; |
525 | u16 thisVUC = block / (nftl->EraseSize / 512); |
526 | struct mtd_info *mtd = nftl->mbd.mtd; |
527 | unsigned int writeEUN; |
528 | unsigned long blockofs = (block * 512) & (nftl->EraseSize -1); |
529 | size_t retlen; |
530 | int silly, silly2 = 3; |
531 | struct nftl_oob oob; |
532 | |
533 | do { |
534 | /* Scan the media to find a unit in the VUC which has |
535 | a free space for the block in question. |
536 | */ |
537 | |
538 | /* This condition catches the 0x[7f]fff cases, as well as |
539 | being a sanity check for past-end-of-media access |
540 | */ |
541 | lastEUN = BLOCK_NIL; |
542 | writeEUN = nftl->EUNtable[thisVUC]; |
543 | silly = MAX_LOOPS; |
544 | while (writeEUN <= nftl->lastEUN) { |
545 | struct nftl_bci bci; |
546 | size_t retlen; |
547 | unsigned int status; |
548 | |
549 | lastEUN = writeEUN; |
550 | |
551 | nftl_read_oob(mtd, |
552 | offs: (writeEUN * nftl->EraseSize) + blockofs, |
553 | len: 8, retlen: &retlen, buf: (char *)&bci); |
554 | |
555 | pr_debug("Status of block %d in EUN %d is %x\n" , |
556 | block , writeEUN, le16_to_cpu(bci.Status)); |
557 | |
558 | status = bci.Status | bci.Status1; |
559 | switch(status) { |
560 | case SECTOR_FREE: |
561 | return writeEUN; |
562 | |
563 | case SECTOR_DELETED: |
564 | case SECTOR_USED: |
565 | case SECTOR_IGNORE: |
566 | break; |
567 | default: |
568 | // Invalid block. Don't use it any more. Must implement. |
569 | break; |
570 | } |
571 | |
572 | if (!silly--) { |
573 | printk(KERN_WARNING |
574 | "Infinite loop in Virtual Unit Chain 0x%x\n" , |
575 | thisVUC); |
576 | return BLOCK_NIL; |
577 | } |
578 | |
579 | /* Skip to next block in chain */ |
580 | writeEUN = nftl->ReplUnitTable[writeEUN]; |
581 | } |
582 | |
583 | /* OK. We didn't find one in the existing chain, or there |
584 | is no existing chain. */ |
585 | |
586 | /* Try to find an already-free block */ |
587 | writeEUN = NFTL_findfreeblock(nftl, desperate: 0); |
588 | |
589 | if (writeEUN == BLOCK_NIL) { |
590 | /* That didn't work - there were no free blocks just |
591 | waiting to be picked up. We're going to have to fold |
592 | a chain to make room. |
593 | */ |
594 | |
595 | /* First remember the start of this chain */ |
596 | //u16 startEUN = nftl->EUNtable[thisVUC]; |
597 | |
598 | //printk("Write to VirtualUnitChain %d, calling makefreeblock()\n", thisVUC); |
599 | writeEUN = NFTL_makefreeblock(nftl, BLOCK_NIL); |
600 | |
601 | if (writeEUN == BLOCK_NIL) { |
602 | /* OK, we accept that the above comment is |
603 | lying - there may have been free blocks |
604 | last time we called NFTL_findfreeblock(), |
605 | but they are reserved for when we're |
606 | desperate. Well, now we're desperate. |
607 | */ |
608 | pr_debug("Using desperate==1 to find free EUN to accommodate write to VUC %d\n" , thisVUC); |
609 | writeEUN = NFTL_findfreeblock(nftl, desperate: 1); |
610 | } |
611 | if (writeEUN == BLOCK_NIL) { |
612 | /* Ouch. This should never happen - we should |
613 | always be able to make some room somehow. |
614 | If we get here, we've allocated more storage |
615 | space than actual media, or our makefreeblock |
616 | routine is missing something. |
617 | */ |
618 | printk(KERN_WARNING "Cannot make free space.\n" ); |
619 | return BLOCK_NIL; |
620 | } |
621 | //printk("Restarting scan\n"); |
622 | continue; |
623 | } |
624 | |
625 | /* We've found a free block. Insert it into the chain. */ |
626 | |
627 | if (lastEUN != BLOCK_NIL) { |
628 | thisVUC |= 0x8000; /* It's a replacement block */ |
629 | } else { |
630 | /* The first block in a new chain */ |
631 | nftl->EUNtable[thisVUC] = writeEUN; |
632 | } |
633 | |
634 | /* set up the actual EUN we're writing into */ |
635 | /* Both in our cache... */ |
636 | nftl->ReplUnitTable[writeEUN] = BLOCK_NIL; |
637 | |
638 | /* ... and on the flash itself */ |
639 | nftl_read_oob(mtd, offs: writeEUN * nftl->EraseSize + 8, len: 8, |
640 | retlen: &retlen, buf: (char *)&oob.u); |
641 | |
642 | oob.u.a.VirtUnitNum = oob.u.a.SpareVirtUnitNum = cpu_to_le16(thisVUC); |
643 | |
644 | nftl_write_oob(mtd, offs: writeEUN * nftl->EraseSize + 8, len: 8, |
645 | retlen: &retlen, buf: (char *)&oob.u); |
646 | |
647 | /* we link the new block to the chain only after the |
648 | block is ready. It avoids the case where the chain |
649 | could point to a free block */ |
650 | if (lastEUN != BLOCK_NIL) { |
651 | /* Both in our cache... */ |
652 | nftl->ReplUnitTable[lastEUN] = writeEUN; |
653 | /* ... and on the flash itself */ |
654 | nftl_read_oob(mtd, offs: (lastEUN * nftl->EraseSize) + 8, |
655 | len: 8, retlen: &retlen, buf: (char *)&oob.u); |
656 | |
657 | oob.u.a.ReplUnitNum = oob.u.a.SpareReplUnitNum |
658 | = cpu_to_le16(writeEUN); |
659 | |
660 | nftl_write_oob(mtd, offs: (lastEUN * nftl->EraseSize) + 8, |
661 | len: 8, retlen: &retlen, buf: (char *)&oob.u); |
662 | } |
663 | |
664 | return writeEUN; |
665 | |
666 | } while (silly2--); |
667 | |
668 | printk(KERN_WARNING "Error folding to make room for Virtual Unit Chain 0x%x\n" , |
669 | thisVUC); |
670 | return BLOCK_NIL; |
671 | } |
672 | |
673 | static int nftl_writeblock(struct mtd_blktrans_dev *mbd, unsigned long block, |
674 | char *buffer) |
675 | { |
676 | struct NFTLrecord *nftl = (void *)mbd; |
677 | u16 writeEUN; |
678 | unsigned long blockofs = (block * 512) & (nftl->EraseSize - 1); |
679 | size_t retlen; |
680 | struct nftl_oob oob; |
681 | |
682 | writeEUN = NFTL_findwriteunit(nftl, block); |
683 | |
684 | if (writeEUN == BLOCK_NIL) { |
685 | printk(KERN_WARNING |
686 | "NFTL_writeblock(): Cannot find block to write to\n" ); |
687 | /* If we _still_ haven't got a block to use, we're screwed */ |
688 | return 1; |
689 | } |
690 | |
691 | memset(&oob, 0xff, sizeof(struct nftl_oob)); |
692 | oob.b.Status = oob.b.Status1 = SECTOR_USED; |
693 | |
694 | nftl_write(mtd: nftl->mbd.mtd, offs: (writeEUN * nftl->EraseSize) + blockofs, |
695 | len: 512, retlen: &retlen, buf: (char *)buffer, oob: (char *)&oob); |
696 | return 0; |
697 | } |
698 | #endif /* CONFIG_NFTL_RW */ |
699 | |
700 | static int nftl_readblock(struct mtd_blktrans_dev *mbd, unsigned long block, |
701 | char *buffer) |
702 | { |
703 | struct NFTLrecord *nftl = (void *)mbd; |
704 | struct mtd_info *mtd = nftl->mbd.mtd; |
705 | u16 lastgoodEUN; |
706 | u16 thisEUN = nftl->EUNtable[block / (nftl->EraseSize / 512)]; |
707 | unsigned long blockofs = (block * 512) & (nftl->EraseSize - 1); |
708 | unsigned int status; |
709 | int silly = MAX_LOOPS; |
710 | size_t retlen; |
711 | struct nftl_bci bci; |
712 | |
713 | lastgoodEUN = BLOCK_NIL; |
714 | |
715 | if (thisEUN != BLOCK_NIL) { |
716 | while (thisEUN < nftl->nb_blocks) { |
717 | if (nftl_read_oob(mtd, offs: (thisEUN * nftl->EraseSize) + |
718 | blockofs, len: 8, retlen: &retlen, |
719 | buf: (char *)&bci) < 0) |
720 | status = SECTOR_IGNORE; |
721 | else |
722 | status = bci.Status | bci.Status1; |
723 | |
724 | switch (status) { |
725 | case SECTOR_FREE: |
726 | /* no modification of a sector should follow a free sector */ |
727 | goto the_end; |
728 | case SECTOR_DELETED: |
729 | lastgoodEUN = BLOCK_NIL; |
730 | break; |
731 | case SECTOR_USED: |
732 | lastgoodEUN = thisEUN; |
733 | break; |
734 | case SECTOR_IGNORE: |
735 | break; |
736 | default: |
737 | printk("Unknown status for block %ld in EUN %d: %x\n" , |
738 | block, thisEUN, status); |
739 | break; |
740 | } |
741 | |
742 | if (!silly--) { |
743 | printk(KERN_WARNING "Infinite loop in Virtual Unit Chain 0x%lx\n" , |
744 | block / (nftl->EraseSize / 512)); |
745 | return 1; |
746 | } |
747 | thisEUN = nftl->ReplUnitTable[thisEUN]; |
748 | } |
749 | } |
750 | |
751 | the_end: |
752 | if (lastgoodEUN == BLOCK_NIL) { |
753 | /* the requested block is not on the media, return all 0x00 */ |
754 | memset(buffer, 0, 512); |
755 | } else { |
756 | loff_t ptr = (lastgoodEUN * nftl->EraseSize) + blockofs; |
757 | size_t retlen; |
758 | int res = mtd_read(mtd, from: ptr, len: 512, retlen: &retlen, buf: buffer); |
759 | |
760 | if (res < 0 && !mtd_is_bitflip(err: res)) |
761 | return -EIO; |
762 | } |
763 | return 0; |
764 | } |
765 | |
766 | static int nftl_getgeo(struct mtd_blktrans_dev *dev, struct hd_geometry *geo) |
767 | { |
768 | struct NFTLrecord *nftl = (void *)dev; |
769 | |
770 | geo->heads = nftl->heads; |
771 | geo->sectors = nftl->sectors; |
772 | geo->cylinders = nftl->cylinders; |
773 | |
774 | return 0; |
775 | } |
776 | |
777 | /**************************************************************************** |
778 | * |
779 | * Module stuff |
780 | * |
781 | ****************************************************************************/ |
782 | |
783 | |
784 | static struct mtd_blktrans_ops nftl_tr = { |
785 | .name = "nftl" , |
786 | .major = NFTL_MAJOR, |
787 | .part_bits = NFTL_PARTN_BITS, |
788 | .blksize = 512, |
789 | .getgeo = nftl_getgeo, |
790 | .readsect = nftl_readblock, |
791 | #ifdef CONFIG_NFTL_RW |
792 | .writesect = nftl_writeblock, |
793 | #endif |
794 | .add_mtd = nftl_add_mtd, |
795 | .remove_dev = nftl_remove_dev, |
796 | .owner = THIS_MODULE, |
797 | }; |
798 | |
799 | module_mtd_blktrans(nftl_tr); |
800 | |
801 | MODULE_LICENSE("GPL" ); |
802 | MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>, Fabrice Bellard <fabrice.bellard@netgem.com> et al." ); |
803 | MODULE_DESCRIPTION("Support code for NAND Flash Translation Layer, used on M-Systems DiskOnChip 2000 and Millennium" ); |
804 | MODULE_ALIAS_BLOCKDEV_MAJOR(NFTL_MAJOR); |
805 | |