Commit | Line | Data |
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1a59d1b8 | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
1da177e4 | 2 | /* |
a1452a37 DW |
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> | |
1da177e4 LT |
7 | */ |
8 | ||
9 | #define PRERELEASE | |
10 | ||
1da177e4 LT |
11 | #include <linux/kernel.h> |
12 | #include <linux/module.h> | |
13 | #include <asm/errno.h> | |
14 | #include <asm/io.h> | |
7c0f6ba6 | 15 | #include <linux/uaccess.h> |
1da177e4 LT |
16 | #include <linux/delay.h> |
17 | #include <linux/slab.h> | |
1da177e4 LT |
18 | #include <linux/init.h> |
19 | #include <linux/hdreg.h> | |
e7f52163 | 20 | #include <linux/blkdev.h> |
1da177e4 LT |
21 | |
22 | #include <linux/kmod.h> | |
23 | #include <linux/mtd/mtd.h> | |
d4092d76 | 24 | #include <linux/mtd/rawnand.h> |
1da177e4 LT |
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 | ||
818b9739 | 40 | if (!mtd_type_is_nand(mtd) || mtd->size > UINT_MAX) |
1da177e4 LT |
41 | return; |
42 | /* OK, this is moderately ugly. But probably safe. Alternatives? */ | |
43 | if (memcmp(mtd->name, "DiskOnChip", 10)) | |
44 | return; | |
45 | ||
289c0522 | 46 | pr_debug("NFTL: add_mtd for %s\n", mtd->name); |
1da177e4 | 47 | |
95b93a0c | 48 | nftl = kzalloc(sizeof(struct NFTLrecord), GFP_KERNEL); |
1da177e4 | 49 | |
0870066d | 50 | if (!nftl) |
1da177e4 | 51 | return; |
1da177e4 LT |
52 | |
53 | nftl->mbd.mtd = mtd; | |
54 | nftl->mbd.devnum = -1; | |
19187672 | 55 | |
1da177e4 | 56 | nftl->mbd.tr = tr; |
1da177e4 LT |
57 | |
58 | if (NFTL_mount(nftl) < 0) { | |
59 | printk(KERN_WARNING "NFTL: could not mount device\n"); | |
60 | kfree(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 | /* | |
97894cda | 86 | Oh no we don't have |
1da177e4 LT |
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", | |
97894cda | 93 | nftl->cylinders, nftl->heads , nftl->sectors, |
1da177e4 LT |
94 | (long)nftl->cylinders * (long)nftl->heads * |
95 | (long)nftl->sectors ); | |
96 | } | |
97 | ||
98 | if (add_mtd_blktrans_dev(&nftl->mbd)) { | |
fa671646 JJ |
99 | kfree(nftl->ReplUnitTable); |
100 | kfree(nftl->EUNtable); | |
1da177e4 LT |
101 | kfree(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 | ||
289c0522 | 113 | pr_debug("NFTL: remove_dev (i=%d)\n", dev->devnum); |
1da177e4 LT |
114 | |
115 | del_mtd_blktrans_dev(dev); | |
fa671646 JJ |
116 | kfree(nftl->ReplUnitTable); |
117 | kfree(nftl->EUNtable); | |
1da177e4 LT |
118 | } |
119 | ||
8593fbc6 TG |
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 | { | |
16f05c2b | 126 | loff_t mask = mtd->writesize - 1; |
8593fbc6 TG |
127 | struct mtd_oob_ops ops; |
128 | int res; | |
129 | ||
0612b9dd | 130 | ops.mode = MTD_OPS_PLACE_OOB; |
16f05c2b | 131 | ops.ooboffs = offs & mask; |
8593fbc6 TG |
132 | ops.ooblen = len; |
133 | ops.oobbuf = buf; | |
134 | ops.datbuf = NULL; | |
8593fbc6 | 135 | |
fd2819bb | 136 | res = mtd_read_oob(mtd, offs & ~mask, &ops); |
7014568b | 137 | *retlen = ops.oobretlen; |
8593fbc6 TG |
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 | { | |
16f05c2b | 147 | loff_t mask = mtd->writesize - 1; |
8593fbc6 TG |
148 | struct mtd_oob_ops ops; |
149 | int res; | |
150 | ||
0612b9dd | 151 | ops.mode = MTD_OPS_PLACE_OOB; |
16f05c2b | 152 | ops.ooboffs = offs & mask; |
8593fbc6 TG |
153 | ops.ooblen = len; |
154 | ops.oobbuf = buf; | |
155 | ops.datbuf = NULL; | |
8593fbc6 | 156 | |
a2cc5ba0 | 157 | res = mtd_write_oob(mtd, offs & ~mask, &ops); |
7014568b | 158 | *retlen = ops.oobretlen; |
8593fbc6 TG |
159 | return res; |
160 | } | |
161 | ||
553a8012 FD |
162 | #ifdef CONFIG_NFTL_RW |
163 | ||
8593fbc6 TG |
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 | { | |
16f05c2b | 170 | loff_t mask = mtd->writesize - 1; |
8593fbc6 TG |
171 | struct mtd_oob_ops ops; |
172 | int res; | |
173 | ||
0612b9dd | 174 | ops.mode = MTD_OPS_PLACE_OOB; |
16f05c2b | 175 | ops.ooboffs = offs & mask; |
8593fbc6 TG |
176 | ops.ooblen = mtd->oobsize; |
177 | ops.oobbuf = oob; | |
178 | ops.datbuf = buf; | |
179 | ops.len = len; | |
180 | ||
a2cc5ba0 | 181 | res = mtd_write_oob(mtd, offs & ~mask, &ops); |
8593fbc6 TG |
182 | *retlen = ops.retlen; |
183 | return res; | |
184 | } | |
185 | ||
1da177e4 LT |
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) { | |
289c0522 | 201 | pr_debug("NFTL_findfreeblock: there are too few free EUNs\n"); |
70ec3bb8 | 202 | return BLOCK_NIL; |
1da177e4 LT |
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, " | |
97894cda | 222 | "FirstEUN = %d\n", nftl->LastFreeEUN, |
1da177e4 | 223 | le16_to_cpu(nftl->MediaHdr.FirstPhysicalEUN)); |
70ec3bb8 | 224 | return BLOCK_NIL; |
1da177e4 LT |
225 | } |
226 | } while (pot != nftl->LastFreeEUN); | |
227 | ||
70ec3bb8 | 228 | return BLOCK_NIL; |
1da177e4 LT |
229 | } |
230 | ||
231 | static u16 NFTL_foldchain (struct NFTLrecord *nftl, unsigned thisVUC, unsigned pendingblock ) | |
232 | { | |
f4a43cfc | 233 | struct mtd_info *mtd = nftl->mbd.mtd; |
1da177e4 LT |
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; | |
f4a43cfc | 243 | size_t retlen; |
1da177e4 LT |
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 | } | |
97894cda | 255 | |
1da177e4 LT |
256 | /* Scan to find the Erase Unit which holds the actual data for each |
257 | 512-byte block within the Chain. | |
258 | */ | |
f4a43cfc | 259 | silly = MAX_LOOPS; |
1da177e4 LT |
260 | targetEUN = BLOCK_NIL; |
261 | while (thisEUN <= nftl->lastEUN ) { | |
f4a43cfc | 262 | unsigned int status, foldmark; |
1da177e4 LT |
263 | |
264 | targetEUN = thisEUN; | |
265 | for (block = 0; block < nftl->EraseSize / 512; block ++) { | |
8593fbc6 | 266 | nftl_read_oob(mtd, (thisEUN * nftl->EraseSize) + |
f4a43cfc TG |
267 | (block * 512), 16 , &retlen, |
268 | (char *)&oob); | |
1da177e4 | 269 | if (block == 2) { |
f4a43cfc TG |
270 | foldmark = oob.u.c.FoldMark | oob.u.c.FoldMark1; |
271 | if (foldmark == FOLD_MARK_IN_PROGRESS) { | |
289c0522 | 272 | pr_debug("Write Inhibited on EUN %d\n", thisEUN); |
1da177e4 LT |
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 | } | |
f4a43cfc | 281 | status = oob.b.Status | oob.b.Status1; |
1da177e4 LT |
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 | |
97894cda | 293 | printk(KERN_WARNING |
1da177e4 LT |
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 | |
97894cda | 302 | printk(KERN_WARNING |
1da177e4 LT |
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 | } | |
97894cda | 321 | |
1da177e4 LT |
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 | |
97894cda | 328 | with them (i.e. BlockMap[block] != BLOCK_NIL) are |
1da177e4 LT |
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) { | |
289c0522 | 337 | pr_debug("Setting inplace to 0. VUC %d, " |
1da177e4 LT |
338 | "block %d was %x lastEUN, " |
339 | "and is in EUN %d (%s) %d\n", | |
340 | thisVUC, block, BlockLastState[block], | |
97894cda | 341 | BlockMap[block], |
1da177e4 LT |
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) { | |
289c0522 | 353 | pr_debug("Pending write not free in EUN %d. " |
1da177e4 LT |
354 | "Folding out of place.\n", targetEUN); |
355 | inplace = 0; | |
356 | } | |
357 | } | |
97894cda | 358 | |
1da177e4 | 359 | if (!inplace) { |
289c0522 | 360 | pr_debug("Cannot fold Virtual Unit Chain %d in place. " |
1da177e4 LT |
361 | "Trying out-of-place\n", thisVUC); |
362 | /* We need to find a targetEUN to fold into. */ | |
363 | targetEUN = NFTL_findfreeblock(nftl, 1); | |
364 | if (targetEUN == BLOCK_NIL) { | |
97894cda | 365 | /* Ouch. Now we're screwed. We need to do a |
1da177e4 LT |
366 | fold-in-place of another chain to make room |
367 | for this one. We need a better way of selecting | |
97894cda | 368 | which chain to fold, because makefreeblock will |
1da177e4 LT |
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 { | |
f4a43cfc TG |
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; | |
8593fbc6 | 382 | nftl_write_oob(mtd, (nftl->EraseSize * targetEUN) + 2 * 512 + 8, |
f4a43cfc TG |
383 | 8, &retlen, (char *)&oob.u); |
384 | } | |
1da177e4 LT |
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 | */ | |
289c0522 | 390 | pr_debug("Folding chain %d into unit %d\n", thisVUC, targetEUN); |
1da177e4 LT |
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 | ||
f4a43cfc | 401 | /* copy only in non free block (free blocks can only |
1da177e4 | 402 | happen in case of media errors or deleted blocks) */ |
f4a43cfc TG |
403 | if (BlockMap[block] == BLOCK_NIL) |
404 | continue; | |
405 | ||
329ad399 AB |
406 | ret = mtd_read(mtd, |
407 | (nftl->EraseSize * BlockMap[block]) + (block * 512), | |
408 | 512, | |
409 | &retlen, | |
410 | movebuf); | |
d57f4054 | 411 | if (ret < 0 && !mtd_is_bitflip(ret)) { |
329ad399 AB |
412 | ret = mtd_read(mtd, |
413 | (nftl->EraseSize * BlockMap[block]) + (block * 512), | |
414 | 512, | |
415 | &retlen, | |
416 | movebuf); | |
f4a43cfc TG |
417 | if (ret != -EIO) |
418 | printk("Error went away on retry.\n"); | |
419 | } | |
1da177e4 LT |
420 | memset(&oob, 0xff, sizeof(struct nftl_oob)); |
421 | oob.b.Status = oob.b.Status1 = SECTOR_USED; | |
9223a456 | 422 | |
8593fbc6 TG |
423 | nftl_write(nftl->mbd.mtd, (nftl->EraseSize * targetEUN) + |
424 | (block * 512), 512, &retlen, movebuf, (char *)&oob); | |
1da177e4 | 425 | } |
97894cda | 426 | |
f4a43cfc TG |
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); | |
70ec3bb8 | 429 | oob.u.a.ReplUnitNum = oob.u.a.SpareReplUnitNum = BLOCK_NIL; |
97894cda | 430 | |
8593fbc6 | 431 | nftl_write_oob(mtd, (nftl->EraseSize * targetEUN) + 8, |
f4a43cfc | 432 | 8, &retlen, (char *)&oob.u); |
1da177e4 LT |
433 | |
434 | /* OK. We've moved the whole lot into the new block. Now we have to free the original blocks. */ | |
435 | ||
97894cda | 436 | /* At this point, we have two different chains for this Virtual Unit, and no way to tell |
1da177e4 LT |
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]; | |
289c0522 | 442 | pr_debug("Want to erase\n"); |
1da177e4 | 443 | |
97894cda | 444 | /* For each block in the old chain (except the targetEUN of course), |
1da177e4 LT |
445 | free it and make it available for future use */ |
446 | while (thisEUN <= nftl->lastEUN && thisEUN != targetEUN) { | |
447 | unsigned int EUNtmp; | |
448 | ||
f4a43cfc | 449 | EUNtmp = nftl->ReplUnitTable[thisEUN]; |
1da177e4 | 450 | |
f4a43cfc | 451 | if (NFTL_formatblock(nftl, thisEUN) < 0) { |
1da177e4 LT |
452 | /* could not erase : mark block as reserved |
453 | */ | |
454 | nftl->ReplUnitTable[thisEUN] = BLOCK_RESERVED; | |
f4a43cfc | 455 | } else { |
1da177e4 LT |
456 | /* correctly erased : mark it as free */ |
457 | nftl->ReplUnitTable[thisEUN] = BLOCK_FREE; | |
458 | nftl->numfreeEUNs++; | |
f4a43cfc TG |
459 | } |
460 | thisEUN = EUNtmp; | |
1da177e4 | 461 | } |
97894cda | 462 | |
1da177e4 LT |
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 | { | |
97894cda | 472 | /* This is the part that needs some cleverness applied. |
1da177e4 LT |
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"); | |
70ec3bb8 | 513 | return BLOCK_NIL; |
1da177e4 LT |
514 | } |
515 | ||
516 | return NFTL_foldchain (nftl, LongestChain, pendingblock); | |
517 | } | |
518 | ||
97894cda | 519 | /* NFTL_findwriteunit: Return the unit number into which we can write |
1da177e4 LT |
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); | |
f4a43cfc | 526 | struct mtd_info *mtd = nftl->mbd.mtd; |
1da177e4 LT |
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 | ||
97894cda | 538 | /* This condition catches the 0x[7f]fff cases, as well as |
1da177e4 LT |
539 | being a sanity check for past-end-of-media access |
540 | */ | |
541 | lastEUN = BLOCK_NIL; | |
542 | writeEUN = nftl->EUNtable[thisVUC]; | |
f4a43cfc | 543 | silly = MAX_LOOPS; |
1da177e4 LT |
544 | while (writeEUN <= nftl->lastEUN) { |
545 | struct nftl_bci bci; | |
546 | size_t retlen; | |
f4a43cfc | 547 | unsigned int status; |
1da177e4 LT |
548 | |
549 | lastEUN = writeEUN; | |
550 | ||
8593fbc6 | 551 | nftl_read_oob(mtd, |
f4a43cfc TG |
552 | (writeEUN * nftl->EraseSize) + blockofs, |
553 | 8, &retlen, (char *)&bci); | |
97894cda | 554 | |
289c0522 | 555 | pr_debug("Status of block %d in EUN %d is %x\n", |
1da177e4 LT |
556 | block , writeEUN, le16_to_cpu(bci.Status)); |
557 | ||
f4a43cfc | 558 | status = bci.Status | bci.Status1; |
1da177e4 LT |
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. | |
97894cda | 569 | break; |
1da177e4 | 570 | } |
97894cda TG |
571 | |
572 | if (!silly--) { | |
1da177e4 LT |
573 | printk(KERN_WARNING |
574 | "Infinite loop in Virtual Unit Chain 0x%x\n", | |
575 | thisVUC); | |
70ec3bb8 | 576 | return BLOCK_NIL; |
1da177e4 LT |
577 | } |
578 | ||
579 | /* Skip to next block in chain */ | |
580 | writeEUN = nftl->ReplUnitTable[writeEUN]; | |
581 | } | |
582 | ||
97894cda | 583 | /* OK. We didn't find one in the existing chain, or there |
1da177e4 LT |
584 | is no existing chain. */ |
585 | ||
586 | /* Try to find an already-free block */ | |
587 | writeEUN = NFTL_findfreeblock(nftl, 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]; | |
97894cda | 597 | |
1da177e4 | 598 | //printk("Write to VirtualUnitChain %d, calling makefreeblock()\n", thisVUC); |
70ec3bb8 | 599 | writeEUN = NFTL_makefreeblock(nftl, BLOCK_NIL); |
1da177e4 LT |
600 | |
601 | if (writeEUN == BLOCK_NIL) { | |
97894cda | 602 | /* OK, we accept that the above comment is |
1da177e4 LT |
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 | */ | |
289c0522 | 608 | pr_debug("Using desperate==1 to find free EUN to accommodate write to VUC %d\n", thisVUC); |
1da177e4 LT |
609 | writeEUN = NFTL_findfreeblock(nftl, 1); |
610 | } | |
611 | if (writeEUN == BLOCK_NIL) { | |
612 | /* Ouch. This should never happen - we should | |
97894cda TG |
613 | always be able to make some room somehow. |
614 | If we get here, we've allocated more storage | |
1da177e4 LT |
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; | |
97894cda | 620 | } |
1da177e4 LT |
621 | //printk("Restarting scan\n"); |
622 | lastEUN = BLOCK_NIL; | |
623 | continue; | |
624 | } | |
625 | ||
626 | /* We've found a free block. Insert it into the chain. */ | |
97894cda | 627 | |
1da177e4 | 628 | if (lastEUN != BLOCK_NIL) { |
f4a43cfc | 629 | thisVUC |= 0x8000; /* It's a replacement block */ |
1da177e4 | 630 | } else { |
f4a43cfc TG |
631 | /* The first block in a new chain */ |
632 | nftl->EUNtable[thisVUC] = writeEUN; | |
1da177e4 LT |
633 | } |
634 | ||
635 | /* set up the actual EUN we're writing into */ | |
636 | /* Both in our cache... */ | |
637 | nftl->ReplUnitTable[writeEUN] = BLOCK_NIL; | |
638 | ||
639 | /* ... and on the flash itself */ | |
8593fbc6 | 640 | nftl_read_oob(mtd, writeEUN * nftl->EraseSize + 8, 8, |
f4a43cfc | 641 | &retlen, (char *)&oob.u); |
1da177e4 LT |
642 | |
643 | oob.u.a.VirtUnitNum = oob.u.a.SpareVirtUnitNum = cpu_to_le16(thisVUC); | |
644 | ||
8593fbc6 | 645 | nftl_write_oob(mtd, writeEUN * nftl->EraseSize + 8, 8, |
f4a43cfc | 646 | &retlen, (char *)&oob.u); |
1da177e4 | 647 | |
f4a43cfc | 648 | /* we link the new block to the chain only after the |
1da177e4 LT |
649 | block is ready. It avoids the case where the chain |
650 | could point to a free block */ | |
f4a43cfc | 651 | if (lastEUN != BLOCK_NIL) { |
1da177e4 LT |
652 | /* Both in our cache... */ |
653 | nftl->ReplUnitTable[lastEUN] = writeEUN; | |
654 | /* ... and on the flash itself */ | |
8593fbc6 | 655 | nftl_read_oob(mtd, (lastEUN * nftl->EraseSize) + 8, |
f4a43cfc | 656 | 8, &retlen, (char *)&oob.u); |
1da177e4 LT |
657 | |
658 | oob.u.a.ReplUnitNum = oob.u.a.SpareReplUnitNum | |
659 | = cpu_to_le16(writeEUN); | |
660 | ||
8593fbc6 | 661 | nftl_write_oob(mtd, (lastEUN * nftl->EraseSize) + 8, |
f4a43cfc | 662 | 8, &retlen, (char *)&oob.u); |
1da177e4 LT |
663 | } |
664 | ||
665 | return writeEUN; | |
666 | ||
667 | } while (silly2--); | |
668 | ||
669 | printk(KERN_WARNING "Error folding to make room for Virtual Unit Chain 0x%x\n", | |
670 | thisVUC); | |
70ec3bb8 | 671 | return BLOCK_NIL; |
1da177e4 LT |
672 | } |
673 | ||
674 | static int nftl_writeblock(struct mtd_blktrans_dev *mbd, unsigned long block, | |
675 | char *buffer) | |
676 | { | |
677 | struct NFTLrecord *nftl = (void *)mbd; | |
678 | u16 writeEUN; | |
679 | unsigned long blockofs = (block * 512) & (nftl->EraseSize - 1); | |
680 | size_t retlen; | |
681 | struct nftl_oob oob; | |
682 | ||
683 | writeEUN = NFTL_findwriteunit(nftl, block); | |
684 | ||
685 | if (writeEUN == BLOCK_NIL) { | |
686 | printk(KERN_WARNING | |
687 | "NFTL_writeblock(): Cannot find block to write to\n"); | |
688 | /* If we _still_ haven't got a block to use, we're screwed */ | |
689 | return 1; | |
690 | } | |
691 | ||
692 | memset(&oob, 0xff, sizeof(struct nftl_oob)); | |
693 | oob.b.Status = oob.b.Status1 = SECTOR_USED; | |
1da177e4 | 694 | |
8593fbc6 TG |
695 | nftl_write(nftl->mbd.mtd, (writeEUN * nftl->EraseSize) + blockofs, |
696 | 512, &retlen, (char *)buffer, (char *)&oob); | |
1da177e4 LT |
697 | return 0; |
698 | } | |
699 | #endif /* CONFIG_NFTL_RW */ | |
700 | ||
701 | static int nftl_readblock(struct mtd_blktrans_dev *mbd, unsigned long block, | |
702 | char *buffer) | |
703 | { | |
704 | struct NFTLrecord *nftl = (void *)mbd; | |
f4a43cfc | 705 | struct mtd_info *mtd = nftl->mbd.mtd; |
1da177e4 LT |
706 | u16 lastgoodEUN; |
707 | u16 thisEUN = nftl->EUNtable[block / (nftl->EraseSize / 512)]; | |
708 | unsigned long blockofs = (block * 512) & (nftl->EraseSize - 1); | |
f4a43cfc | 709 | unsigned int status; |
1da177e4 | 710 | int silly = MAX_LOOPS; |
f4a43cfc TG |
711 | size_t retlen; |
712 | struct nftl_bci bci; | |
1da177e4 LT |
713 | |
714 | lastgoodEUN = BLOCK_NIL; | |
715 | ||
f4a43cfc | 716 | if (thisEUN != BLOCK_NIL) { |
1da177e4 | 717 | while (thisEUN < nftl->nb_blocks) { |
8593fbc6 | 718 | if (nftl_read_oob(mtd, (thisEUN * nftl->EraseSize) + |
f4a43cfc TG |
719 | blockofs, 8, &retlen, |
720 | (char *)&bci) < 0) | |
1da177e4 LT |
721 | status = SECTOR_IGNORE; |
722 | else | |
723 | status = bci.Status | bci.Status1; | |
724 | ||
725 | switch (status) { | |
726 | case SECTOR_FREE: | |
727 | /* no modification of a sector should follow a free sector */ | |
728 | goto the_end; | |
729 | case SECTOR_DELETED: | |
730 | lastgoodEUN = BLOCK_NIL; | |
731 | break; | |
732 | case SECTOR_USED: | |
733 | lastgoodEUN = thisEUN; | |
734 | break; | |
735 | case SECTOR_IGNORE: | |
736 | break; | |
737 | default: | |
738 | printk("Unknown status for block %ld in EUN %d: %x\n", | |
739 | block, thisEUN, status); | |
740 | break; | |
741 | } | |
742 | ||
743 | if (!silly--) { | |
744 | printk(KERN_WARNING "Infinite loop in Virtual Unit Chain 0x%lx\n", | |
745 | block / (nftl->EraseSize / 512)); | |
746 | return 1; | |
747 | } | |
748 | thisEUN = nftl->ReplUnitTable[thisEUN]; | |
749 | } | |
f4a43cfc | 750 | } |
1da177e4 LT |
751 | |
752 | the_end: | |
753 | if (lastgoodEUN == BLOCK_NIL) { | |
754 | /* the requested block is not on the media, return all 0x00 */ | |
755 | memset(buffer, 0, 512); | |
756 | } else { | |
757 | loff_t ptr = (lastgoodEUN * nftl->EraseSize) + blockofs; | |
758 | size_t retlen; | |
329ad399 | 759 | int res = mtd_read(mtd, ptr, 512, &retlen, buffer); |
9a1fcdfd | 760 | |
d57f4054 | 761 | if (res < 0 && !mtd_is_bitflip(res)) |
1da177e4 LT |
762 | return -EIO; |
763 | } | |
764 | return 0; | |
765 | } | |
766 | ||
767 | static int nftl_getgeo(struct mtd_blktrans_dev *dev, struct hd_geometry *geo) | |
768 | { | |
769 | struct NFTLrecord *nftl = (void *)dev; | |
770 | ||
771 | geo->heads = nftl->heads; | |
772 | geo->sectors = nftl->sectors; | |
773 | geo->cylinders = nftl->cylinders; | |
774 | ||
775 | return 0; | |
776 | } | |
777 | ||
778 | /**************************************************************************** | |
779 | * | |
780 | * Module stuff | |
781 | * | |
782 | ****************************************************************************/ | |
783 | ||
784 | ||
785 | static struct mtd_blktrans_ops nftl_tr = { | |
786 | .name = "nftl", | |
787 | .major = NFTL_MAJOR, | |
788 | .part_bits = NFTL_PARTN_BITS, | |
19187672 | 789 | .blksize = 512, |
1da177e4 LT |
790 | .getgeo = nftl_getgeo, |
791 | .readsect = nftl_readblock, | |
792 | #ifdef CONFIG_NFTL_RW | |
793 | .writesect = nftl_writeblock, | |
794 | #endif | |
795 | .add_mtd = nftl_add_mtd, | |
796 | .remove_dev = nftl_remove_dev, | |
797 | .owner = THIS_MODULE, | |
798 | }; | |
799 | ||
1da177e4 LT |
800 | static int __init init_nftl(void) |
801 | { | |
1da177e4 LT |
802 | return register_mtd_blktrans(&nftl_tr); |
803 | } | |
804 | ||
805 | static void __exit cleanup_nftl(void) | |
806 | { | |
807 | deregister_mtd_blktrans(&nftl_tr); | |
808 | } | |
809 | ||
810 | module_init(init_nftl); | |
811 | module_exit(cleanup_nftl); | |
812 | ||
813 | MODULE_LICENSE("GPL"); | |
814 | MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>, Fabrice Bellard <fabrice.bellard@netgem.com> et al."); | |
815 | MODULE_DESCRIPTION("Support code for NAND Flash Translation Layer, used on M-Systems DiskOnChip 2000 and Millennium"); | |
e7f52163 | 816 | MODULE_ALIAS_BLOCKDEV_MAJOR(NFTL_MAJOR); |