Commit | Line | Data |
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1da177e4 LT |
1 | /* Linux driver for NAND Flash Translation Layer */ |
2 | /* (c) 1999 Machine Vision Holdings, Inc. */ | |
3 | /* Author: David Woodhouse <dwmw2@infradead.org> */ | |
1da177e4 LT |
4 | |
5 | /* | |
6 | The contents of this file are distributed under the GNU General | |
7 | Public License version 2. The author places no additional | |
8 | restrictions of any kind on it. | |
9 | */ | |
10 | ||
11 | #define PRERELEASE | |
12 | ||
1da177e4 LT |
13 | #include <linux/kernel.h> |
14 | #include <linux/module.h> | |
15 | #include <asm/errno.h> | |
16 | #include <asm/io.h> | |
17 | #include <asm/uaccess.h> | |
1da177e4 LT |
18 | #include <linux/delay.h> |
19 | #include <linux/slab.h> | |
1da177e4 LT |
20 | #include <linux/init.h> |
21 | #include <linux/hdreg.h> | |
e7f52163 | 22 | #include <linux/blkdev.h> |
1da177e4 LT |
23 | |
24 | #include <linux/kmod.h> | |
25 | #include <linux/mtd/mtd.h> | |
26 | #include <linux/mtd/nand.h> | |
27 | #include <linux/mtd/nftl.h> | |
28 | #include <linux/mtd/blktrans.h> | |
29 | ||
30 | /* maximum number of loops while examining next block, to have a | |
31 | chance to detect consistency problems (they should never happen | |
32 | because of the checks done in the mounting */ | |
33 | ||
34 | #define MAX_LOOPS 10000 | |
35 | ||
36 | ||
37 | static void nftl_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd) | |
38 | { | |
39 | struct NFTLrecord *nftl; | |
40 | unsigned long temp; | |
41 | ||
69423d99 | 42 | if (mtd->type != MTD_NANDFLASH || mtd->size > UINT_MAX) |
1da177e4 LT |
43 | return; |
44 | /* OK, this is moderately ugly. But probably safe. Alternatives? */ | |
45 | if (memcmp(mtd->name, "DiskOnChip", 10)) | |
46 | return; | |
47 | ||
48 | if (!mtd->block_isbad) { | |
49 | printk(KERN_ERR | |
50 | "NFTL no longer supports the old DiskOnChip drivers loaded via docprobe.\n" | |
51 | "Please use the new diskonchip driver under the NAND subsystem.\n"); | |
52 | return; | |
53 | } | |
54 | ||
55 | DEBUG(MTD_DEBUG_LEVEL1, "NFTL: add_mtd for %s\n", mtd->name); | |
56 | ||
95b93a0c | 57 | nftl = kzalloc(sizeof(struct NFTLrecord), GFP_KERNEL); |
1da177e4 LT |
58 | |
59 | if (!nftl) { | |
60 | printk(KERN_WARNING "NFTL: out of memory for data structures\n"); | |
61 | return; | |
62 | } | |
1da177e4 LT |
63 | |
64 | nftl->mbd.mtd = mtd; | |
65 | nftl->mbd.devnum = -1; | |
19187672 | 66 | |
1da177e4 | 67 | nftl->mbd.tr = tr; |
1da177e4 LT |
68 | |
69 | if (NFTL_mount(nftl) < 0) { | |
70 | printk(KERN_WARNING "NFTL: could not mount device\n"); | |
71 | kfree(nftl); | |
72 | return; | |
73 | } | |
74 | ||
75 | /* OK, it's a new one. Set up all the data structures. */ | |
76 | ||
77 | /* Calculate geometry */ | |
78 | nftl->cylinders = 1024; | |
79 | nftl->heads = 16; | |
80 | ||
81 | temp = nftl->cylinders * nftl->heads; | |
82 | nftl->sectors = nftl->mbd.size / temp; | |
83 | if (nftl->mbd.size % temp) { | |
84 | nftl->sectors++; | |
85 | temp = nftl->cylinders * nftl->sectors; | |
86 | nftl->heads = nftl->mbd.size / temp; | |
87 | ||
88 | if (nftl->mbd.size % temp) { | |
89 | nftl->heads++; | |
90 | temp = nftl->heads * nftl->sectors; | |
91 | nftl->cylinders = nftl->mbd.size / temp; | |
92 | } | |
93 | } | |
94 | ||
95 | if (nftl->mbd.size != nftl->heads * nftl->cylinders * nftl->sectors) { | |
96 | /* | |
97894cda | 97 | Oh no we don't have |
1da177e4 LT |
98 | mbd.size == heads * cylinders * sectors |
99 | */ | |
100 | printk(KERN_WARNING "NFTL: cannot calculate a geometry to " | |
101 | "match size of 0x%lx.\n", nftl->mbd.size); | |
102 | printk(KERN_WARNING "NFTL: using C:%d H:%d S:%d " | |
103 | "(== 0x%lx sects)\n", | |
97894cda | 104 | nftl->cylinders, nftl->heads , nftl->sectors, |
1da177e4 LT |
105 | (long)nftl->cylinders * (long)nftl->heads * |
106 | (long)nftl->sectors ); | |
107 | } | |
108 | ||
109 | if (add_mtd_blktrans_dev(&nftl->mbd)) { | |
fa671646 JJ |
110 | kfree(nftl->ReplUnitTable); |
111 | kfree(nftl->EUNtable); | |
1da177e4 LT |
112 | kfree(nftl); |
113 | return; | |
114 | } | |
115 | #ifdef PSYCHO_DEBUG | |
116 | printk(KERN_INFO "NFTL: Found new nftl%c\n", nftl->mbd.devnum + 'a'); | |
117 | #endif | |
118 | } | |
119 | ||
120 | static void nftl_remove_dev(struct mtd_blktrans_dev *dev) | |
121 | { | |
122 | struct NFTLrecord *nftl = (void *)dev; | |
123 | ||
124 | DEBUG(MTD_DEBUG_LEVEL1, "NFTL: remove_dev (i=%d)\n", dev->devnum); | |
125 | ||
126 | del_mtd_blktrans_dev(dev); | |
fa671646 JJ |
127 | kfree(nftl->ReplUnitTable); |
128 | kfree(nftl->EUNtable); | |
1da177e4 LT |
129 | } |
130 | ||
8593fbc6 TG |
131 | /* |
132 | * Read oob data from flash | |
133 | */ | |
134 | int nftl_read_oob(struct mtd_info *mtd, loff_t offs, size_t len, | |
135 | size_t *retlen, uint8_t *buf) | |
136 | { | |
16f05c2b | 137 | loff_t mask = mtd->writesize - 1; |
8593fbc6 TG |
138 | struct mtd_oob_ops ops; |
139 | int res; | |
140 | ||
141 | ops.mode = MTD_OOB_PLACE; | |
16f05c2b | 142 | ops.ooboffs = offs & mask; |
8593fbc6 TG |
143 | ops.ooblen = len; |
144 | ops.oobbuf = buf; | |
145 | ops.datbuf = NULL; | |
8593fbc6 | 146 | |
16f05c2b | 147 | res = mtd->read_oob(mtd, offs & ~mask, &ops); |
7014568b | 148 | *retlen = ops.oobretlen; |
8593fbc6 TG |
149 | return res; |
150 | } | |
151 | ||
152 | /* | |
153 | * Write oob data to flash | |
154 | */ | |
155 | int nftl_write_oob(struct mtd_info *mtd, loff_t offs, size_t len, | |
156 | size_t *retlen, uint8_t *buf) | |
157 | { | |
16f05c2b | 158 | loff_t mask = mtd->writesize - 1; |
8593fbc6 TG |
159 | struct mtd_oob_ops ops; |
160 | int res; | |
161 | ||
162 | ops.mode = MTD_OOB_PLACE; | |
16f05c2b | 163 | ops.ooboffs = offs & mask; |
8593fbc6 TG |
164 | ops.ooblen = len; |
165 | ops.oobbuf = buf; | |
166 | ops.datbuf = NULL; | |
8593fbc6 | 167 | |
16f05c2b | 168 | res = mtd->write_oob(mtd, offs & ~mask, &ops); |
7014568b | 169 | *retlen = ops.oobretlen; |
8593fbc6 TG |
170 | return res; |
171 | } | |
172 | ||
553a8012 FD |
173 | #ifdef CONFIG_NFTL_RW |
174 | ||
8593fbc6 TG |
175 | /* |
176 | * Write data and oob to flash | |
177 | */ | |
178 | static int nftl_write(struct mtd_info *mtd, loff_t offs, size_t len, | |
179 | size_t *retlen, uint8_t *buf, uint8_t *oob) | |
180 | { | |
16f05c2b | 181 | loff_t mask = mtd->writesize - 1; |
8593fbc6 TG |
182 | struct mtd_oob_ops ops; |
183 | int res; | |
184 | ||
185 | ops.mode = MTD_OOB_PLACE; | |
16f05c2b | 186 | ops.ooboffs = offs & mask; |
8593fbc6 TG |
187 | ops.ooblen = mtd->oobsize; |
188 | ops.oobbuf = oob; | |
189 | ops.datbuf = buf; | |
190 | ops.len = len; | |
191 | ||
16f05c2b | 192 | res = mtd->write_oob(mtd, offs & ~mask, &ops); |
8593fbc6 TG |
193 | *retlen = ops.retlen; |
194 | return res; | |
195 | } | |
196 | ||
1da177e4 LT |
197 | /* Actual NFTL access routines */ |
198 | /* NFTL_findfreeblock: Find a free Erase Unit on the NFTL partition. This function is used | |
199 | * when the give Virtual Unit Chain | |
200 | */ | |
201 | static u16 NFTL_findfreeblock(struct NFTLrecord *nftl, int desperate ) | |
202 | { | |
203 | /* For a given Virtual Unit Chain: find or create a free block and | |
204 | add it to the chain */ | |
205 | /* We're passed the number of the last EUN in the chain, to save us from | |
206 | having to look it up again */ | |
207 | u16 pot = nftl->LastFreeEUN; | |
208 | int silly = nftl->nb_blocks; | |
209 | ||
210 | /* Normally, we force a fold to happen before we run out of free blocks completely */ | |
211 | if (!desperate && nftl->numfreeEUNs < 2) { | |
212 | DEBUG(MTD_DEBUG_LEVEL1, "NFTL_findfreeblock: there are too few free EUNs\n"); | |
70ec3bb8 | 213 | return BLOCK_NIL; |
1da177e4 LT |
214 | } |
215 | ||
216 | /* Scan for a free block */ | |
217 | do { | |
218 | if (nftl->ReplUnitTable[pot] == BLOCK_FREE) { | |
219 | nftl->LastFreeEUN = pot; | |
220 | nftl->numfreeEUNs--; | |
221 | return pot; | |
222 | } | |
223 | ||
224 | /* This will probably point to the MediaHdr unit itself, | |
225 | right at the beginning of the partition. But that unit | |
226 | (and the backup unit too) should have the UCI set | |
227 | up so that it's not selected for overwriting */ | |
228 | if (++pot > nftl->lastEUN) | |
229 | pot = le16_to_cpu(nftl->MediaHdr.FirstPhysicalEUN); | |
230 | ||
231 | if (!silly--) { | |
232 | printk("Argh! No free blocks found! LastFreeEUN = %d, " | |
97894cda | 233 | "FirstEUN = %d\n", nftl->LastFreeEUN, |
1da177e4 | 234 | le16_to_cpu(nftl->MediaHdr.FirstPhysicalEUN)); |
70ec3bb8 | 235 | return BLOCK_NIL; |
1da177e4 LT |
236 | } |
237 | } while (pot != nftl->LastFreeEUN); | |
238 | ||
70ec3bb8 | 239 | return BLOCK_NIL; |
1da177e4 LT |
240 | } |
241 | ||
242 | static u16 NFTL_foldchain (struct NFTLrecord *nftl, unsigned thisVUC, unsigned pendingblock ) | |
243 | { | |
f4a43cfc | 244 | struct mtd_info *mtd = nftl->mbd.mtd; |
1da177e4 LT |
245 | u16 BlockMap[MAX_SECTORS_PER_UNIT]; |
246 | unsigned char BlockLastState[MAX_SECTORS_PER_UNIT]; | |
247 | unsigned char BlockFreeFound[MAX_SECTORS_PER_UNIT]; | |
248 | unsigned int thisEUN; | |
249 | int block; | |
250 | int silly; | |
251 | unsigned int targetEUN; | |
252 | struct nftl_oob oob; | |
253 | int inplace = 1; | |
f4a43cfc | 254 | size_t retlen; |
1da177e4 LT |
255 | |
256 | memset(BlockMap, 0xff, sizeof(BlockMap)); | |
257 | memset(BlockFreeFound, 0, sizeof(BlockFreeFound)); | |
258 | ||
259 | thisEUN = nftl->EUNtable[thisVUC]; | |
260 | ||
261 | if (thisEUN == BLOCK_NIL) { | |
262 | printk(KERN_WARNING "Trying to fold non-existent " | |
263 | "Virtual Unit Chain %d!\n", thisVUC); | |
264 | return BLOCK_NIL; | |
265 | } | |
97894cda | 266 | |
1da177e4 LT |
267 | /* Scan to find the Erase Unit which holds the actual data for each |
268 | 512-byte block within the Chain. | |
269 | */ | |
f4a43cfc | 270 | silly = MAX_LOOPS; |
1da177e4 LT |
271 | targetEUN = BLOCK_NIL; |
272 | while (thisEUN <= nftl->lastEUN ) { | |
f4a43cfc | 273 | unsigned int status, foldmark; |
1da177e4 LT |
274 | |
275 | targetEUN = thisEUN; | |
276 | for (block = 0; block < nftl->EraseSize / 512; block ++) { | |
8593fbc6 | 277 | nftl_read_oob(mtd, (thisEUN * nftl->EraseSize) + |
f4a43cfc TG |
278 | (block * 512), 16 , &retlen, |
279 | (char *)&oob); | |
1da177e4 | 280 | if (block == 2) { |
f4a43cfc TG |
281 | foldmark = oob.u.c.FoldMark | oob.u.c.FoldMark1; |
282 | if (foldmark == FOLD_MARK_IN_PROGRESS) { | |
283 | DEBUG(MTD_DEBUG_LEVEL1, | |
284 | "Write Inhibited on EUN %d\n", thisEUN); | |
1da177e4 LT |
285 | inplace = 0; |
286 | } else { | |
287 | /* There's no other reason not to do inplace, | |
288 | except ones that come later. So we don't need | |
289 | to preserve inplace */ | |
290 | inplace = 1; | |
291 | } | |
292 | } | |
f4a43cfc | 293 | status = oob.b.Status | oob.b.Status1; |
1da177e4 LT |
294 | BlockLastState[block] = status; |
295 | ||
296 | switch(status) { | |
297 | case SECTOR_FREE: | |
298 | BlockFreeFound[block] = 1; | |
299 | break; | |
300 | ||
301 | case SECTOR_USED: | |
302 | if (!BlockFreeFound[block]) | |
303 | BlockMap[block] = thisEUN; | |
304 | else | |
97894cda | 305 | printk(KERN_WARNING |
1da177e4 LT |
306 | "SECTOR_USED found after SECTOR_FREE " |
307 | "in Virtual Unit Chain %d for block %d\n", | |
308 | thisVUC, block); | |
309 | break; | |
310 | case SECTOR_DELETED: | |
311 | if (!BlockFreeFound[block]) | |
312 | BlockMap[block] = BLOCK_NIL; | |
313 | else | |
97894cda | 314 | printk(KERN_WARNING |
1da177e4 LT |
315 | "SECTOR_DELETED found after SECTOR_FREE " |
316 | "in Virtual Unit Chain %d for block %d\n", | |
317 | thisVUC, block); | |
318 | break; | |
319 | ||
320 | case SECTOR_IGNORE: | |
321 | break; | |
322 | default: | |
323 | printk("Unknown status for block %d in EUN %d: %x\n", | |
324 | block, thisEUN, status); | |
325 | } | |
326 | } | |
327 | ||
328 | if (!silly--) { | |
329 | printk(KERN_WARNING "Infinite loop in Virtual Unit Chain 0x%x\n", | |
330 | thisVUC); | |
331 | return BLOCK_NIL; | |
332 | } | |
97894cda | 333 | |
1da177e4 LT |
334 | thisEUN = nftl->ReplUnitTable[thisEUN]; |
335 | } | |
336 | ||
337 | if (inplace) { | |
338 | /* We're being asked to be a fold-in-place. Check | |
339 | that all blocks which actually have data associated | |
97894cda | 340 | with them (i.e. BlockMap[block] != BLOCK_NIL) are |
1da177e4 LT |
341 | either already present or SECTOR_FREE in the target |
342 | block. If not, we're going to have to fold out-of-place | |
343 | anyway. | |
344 | */ | |
345 | for (block = 0; block < nftl->EraseSize / 512 ; block++) { | |
346 | if (BlockLastState[block] != SECTOR_FREE && | |
347 | BlockMap[block] != BLOCK_NIL && | |
348 | BlockMap[block] != targetEUN) { | |
349 | DEBUG(MTD_DEBUG_LEVEL1, "Setting inplace to 0. VUC %d, " | |
350 | "block %d was %x lastEUN, " | |
351 | "and is in EUN %d (%s) %d\n", | |
352 | thisVUC, block, BlockLastState[block], | |
97894cda | 353 | BlockMap[block], |
1da177e4 LT |
354 | BlockMap[block]== targetEUN ? "==" : "!=", |
355 | targetEUN); | |
356 | inplace = 0; | |
357 | break; | |
358 | } | |
359 | } | |
360 | ||
361 | if (pendingblock >= (thisVUC * (nftl->EraseSize / 512)) && | |
362 | pendingblock < ((thisVUC + 1)* (nftl->EraseSize / 512)) && | |
363 | BlockLastState[pendingblock - (thisVUC * (nftl->EraseSize / 512))] != | |
364 | SECTOR_FREE) { | |
365 | DEBUG(MTD_DEBUG_LEVEL1, "Pending write not free in EUN %d. " | |
366 | "Folding out of place.\n", targetEUN); | |
367 | inplace = 0; | |
368 | } | |
369 | } | |
97894cda | 370 | |
1da177e4 LT |
371 | if (!inplace) { |
372 | DEBUG(MTD_DEBUG_LEVEL1, "Cannot fold Virtual Unit Chain %d in place. " | |
373 | "Trying out-of-place\n", thisVUC); | |
374 | /* We need to find a targetEUN to fold into. */ | |
375 | targetEUN = NFTL_findfreeblock(nftl, 1); | |
376 | if (targetEUN == BLOCK_NIL) { | |
97894cda | 377 | /* Ouch. Now we're screwed. We need to do a |
1da177e4 LT |
378 | fold-in-place of another chain to make room |
379 | for this one. We need a better way of selecting | |
97894cda | 380 | which chain to fold, because makefreeblock will |
1da177e4 LT |
381 | only ask us to fold the same one again. |
382 | */ | |
383 | printk(KERN_WARNING | |
384 | "NFTL_findfreeblock(desperate) returns 0xffff.\n"); | |
385 | return BLOCK_NIL; | |
386 | } | |
387 | } else { | |
f4a43cfc TG |
388 | /* We put a fold mark in the chain we are folding only if we |
389 | fold in place to help the mount check code. If we do not fold in | |
390 | place, it is possible to find the valid chain by selecting the | |
391 | longer one */ | |
392 | oob.u.c.FoldMark = oob.u.c.FoldMark1 = cpu_to_le16(FOLD_MARK_IN_PROGRESS); | |
393 | oob.u.c.unused = 0xffffffff; | |
8593fbc6 | 394 | nftl_write_oob(mtd, (nftl->EraseSize * targetEUN) + 2 * 512 + 8, |
f4a43cfc TG |
395 | 8, &retlen, (char *)&oob.u); |
396 | } | |
1da177e4 LT |
397 | |
398 | /* OK. We now know the location of every block in the Virtual Unit Chain, | |
399 | and the Erase Unit into which we are supposed to be copying. | |
400 | Go for it. | |
401 | */ | |
402 | DEBUG(MTD_DEBUG_LEVEL1,"Folding chain %d into unit %d\n", thisVUC, targetEUN); | |
403 | for (block = 0; block < nftl->EraseSize / 512 ; block++) { | |
404 | unsigned char movebuf[512]; | |
405 | int ret; | |
406 | ||
407 | /* If it's in the target EUN already, or if it's pending write, do nothing */ | |
408 | if (BlockMap[block] == targetEUN || | |
409 | (pendingblock == (thisVUC * (nftl->EraseSize / 512) + block))) { | |
410 | continue; | |
411 | } | |
412 | ||
f4a43cfc | 413 | /* copy only in non free block (free blocks can only |
1da177e4 | 414 | happen in case of media errors or deleted blocks) */ |
f4a43cfc TG |
415 | if (BlockMap[block] == BLOCK_NIL) |
416 | continue; | |
417 | ||
418 | ret = mtd->read(mtd, (nftl->EraseSize * BlockMap[block]) + (block * 512), | |
419 | 512, &retlen, movebuf); | |
9a1fcdfd | 420 | if (ret < 0 && ret != -EUCLEAN) { |
f4a43cfc TG |
421 | ret = mtd->read(mtd, (nftl->EraseSize * BlockMap[block]) |
422 | + (block * 512), 512, &retlen, | |
423 | movebuf); | |
424 | if (ret != -EIO) | |
425 | printk("Error went away on retry.\n"); | |
426 | } | |
1da177e4 LT |
427 | memset(&oob, 0xff, sizeof(struct nftl_oob)); |
428 | oob.b.Status = oob.b.Status1 = SECTOR_USED; | |
9223a456 | 429 | |
8593fbc6 TG |
430 | nftl_write(nftl->mbd.mtd, (nftl->EraseSize * targetEUN) + |
431 | (block * 512), 512, &retlen, movebuf, (char *)&oob); | |
1da177e4 | 432 | } |
97894cda | 433 | |
f4a43cfc TG |
434 | /* add the header so that it is now a valid chain */ |
435 | oob.u.a.VirtUnitNum = oob.u.a.SpareVirtUnitNum = cpu_to_le16(thisVUC); | |
70ec3bb8 | 436 | oob.u.a.ReplUnitNum = oob.u.a.SpareReplUnitNum = BLOCK_NIL; |
97894cda | 437 | |
8593fbc6 | 438 | nftl_write_oob(mtd, (nftl->EraseSize * targetEUN) + 8, |
f4a43cfc | 439 | 8, &retlen, (char *)&oob.u); |
1da177e4 LT |
440 | |
441 | /* OK. We've moved the whole lot into the new block. Now we have to free the original blocks. */ | |
442 | ||
97894cda | 443 | /* At this point, we have two different chains for this Virtual Unit, and no way to tell |
1da177e4 LT |
444 | them apart. If we crash now, we get confused. However, both contain the same data, so we |
445 | shouldn't actually lose data in this case. It's just that when we load up on a medium which | |
446 | has duplicate chains, we need to free one of the chains because it's not necessary any more. | |
447 | */ | |
448 | thisEUN = nftl->EUNtable[thisVUC]; | |
449 | DEBUG(MTD_DEBUG_LEVEL1,"Want to erase\n"); | |
450 | ||
97894cda | 451 | /* For each block in the old chain (except the targetEUN of course), |
1da177e4 LT |
452 | free it and make it available for future use */ |
453 | while (thisEUN <= nftl->lastEUN && thisEUN != targetEUN) { | |
454 | unsigned int EUNtmp; | |
455 | ||
f4a43cfc | 456 | EUNtmp = nftl->ReplUnitTable[thisEUN]; |
1da177e4 | 457 | |
f4a43cfc | 458 | if (NFTL_formatblock(nftl, thisEUN) < 0) { |
1da177e4 LT |
459 | /* could not erase : mark block as reserved |
460 | */ | |
461 | nftl->ReplUnitTable[thisEUN] = BLOCK_RESERVED; | |
f4a43cfc | 462 | } else { |
1da177e4 LT |
463 | /* correctly erased : mark it as free */ |
464 | nftl->ReplUnitTable[thisEUN] = BLOCK_FREE; | |
465 | nftl->numfreeEUNs++; | |
f4a43cfc TG |
466 | } |
467 | thisEUN = EUNtmp; | |
1da177e4 | 468 | } |
97894cda | 469 | |
1da177e4 LT |
470 | /* Make this the new start of chain for thisVUC */ |
471 | nftl->ReplUnitTable[targetEUN] = BLOCK_NIL; | |
472 | nftl->EUNtable[thisVUC] = targetEUN; | |
473 | ||
474 | return targetEUN; | |
475 | } | |
476 | ||
477 | static u16 NFTL_makefreeblock( struct NFTLrecord *nftl , unsigned pendingblock) | |
478 | { | |
97894cda | 479 | /* This is the part that needs some cleverness applied. |
1da177e4 LT |
480 | For now, I'm doing the minimum applicable to actually |
481 | get the thing to work. | |
482 | Wear-levelling and other clever stuff needs to be implemented | |
483 | and we also need to do some assessment of the results when | |
484 | the system loses power half-way through the routine. | |
485 | */ | |
486 | u16 LongestChain = 0; | |
487 | u16 ChainLength = 0, thislen; | |
488 | u16 chain, EUN; | |
489 | ||
490 | for (chain = 0; chain < le32_to_cpu(nftl->MediaHdr.FormattedSize) / nftl->EraseSize; chain++) { | |
491 | EUN = nftl->EUNtable[chain]; | |
492 | thislen = 0; | |
493 | ||
494 | while (EUN <= nftl->lastEUN) { | |
495 | thislen++; | |
496 | //printk("VUC %d reaches len %d with EUN %d\n", chain, thislen, EUN); | |
497 | EUN = nftl->ReplUnitTable[EUN] & 0x7fff; | |
498 | if (thislen > 0xff00) { | |
499 | printk("Endless loop in Virtual Chain %d: Unit %x\n", | |
500 | chain, EUN); | |
501 | } | |
502 | if (thislen > 0xff10) { | |
503 | /* Actually, don't return failure. Just ignore this chain and | |
504 | get on with it. */ | |
505 | thislen = 0; | |
506 | break; | |
507 | } | |
508 | } | |
509 | ||
510 | if (thislen > ChainLength) { | |
511 | //printk("New longest chain is %d with length %d\n", chain, thislen); | |
512 | ChainLength = thislen; | |
513 | LongestChain = chain; | |
514 | } | |
515 | } | |
516 | ||
517 | if (ChainLength < 2) { | |
518 | printk(KERN_WARNING "No Virtual Unit Chains available for folding. " | |
519 | "Failing request\n"); | |
70ec3bb8 | 520 | return BLOCK_NIL; |
1da177e4 LT |
521 | } |
522 | ||
523 | return NFTL_foldchain (nftl, LongestChain, pendingblock); | |
524 | } | |
525 | ||
97894cda | 526 | /* NFTL_findwriteunit: Return the unit number into which we can write |
1da177e4 LT |
527 | for this block. Make it available if it isn't already |
528 | */ | |
529 | static inline u16 NFTL_findwriteunit(struct NFTLrecord *nftl, unsigned block) | |
530 | { | |
531 | u16 lastEUN; | |
532 | u16 thisVUC = block / (nftl->EraseSize / 512); | |
f4a43cfc | 533 | struct mtd_info *mtd = nftl->mbd.mtd; |
1da177e4 LT |
534 | unsigned int writeEUN; |
535 | unsigned long blockofs = (block * 512) & (nftl->EraseSize -1); | |
536 | size_t retlen; | |
537 | int silly, silly2 = 3; | |
538 | struct nftl_oob oob; | |
539 | ||
540 | do { | |
541 | /* Scan the media to find a unit in the VUC which has | |
542 | a free space for the block in question. | |
543 | */ | |
544 | ||
97894cda | 545 | /* This condition catches the 0x[7f]fff cases, as well as |
1da177e4 LT |
546 | being a sanity check for past-end-of-media access |
547 | */ | |
548 | lastEUN = BLOCK_NIL; | |
549 | writeEUN = nftl->EUNtable[thisVUC]; | |
f4a43cfc | 550 | silly = MAX_LOOPS; |
1da177e4 LT |
551 | while (writeEUN <= nftl->lastEUN) { |
552 | struct nftl_bci bci; | |
553 | size_t retlen; | |
f4a43cfc | 554 | unsigned int status; |
1da177e4 LT |
555 | |
556 | lastEUN = writeEUN; | |
557 | ||
8593fbc6 | 558 | nftl_read_oob(mtd, |
f4a43cfc TG |
559 | (writeEUN * nftl->EraseSize) + blockofs, |
560 | 8, &retlen, (char *)&bci); | |
97894cda | 561 | |
1da177e4 LT |
562 | DEBUG(MTD_DEBUG_LEVEL2, "Status of block %d in EUN %d is %x\n", |
563 | block , writeEUN, le16_to_cpu(bci.Status)); | |
564 | ||
f4a43cfc | 565 | status = bci.Status | bci.Status1; |
1da177e4 LT |
566 | switch(status) { |
567 | case SECTOR_FREE: | |
568 | return writeEUN; | |
569 | ||
570 | case SECTOR_DELETED: | |
571 | case SECTOR_USED: | |
572 | case SECTOR_IGNORE: | |
573 | break; | |
574 | default: | |
575 | // Invalid block. Don't use it any more. Must implement. | |
97894cda | 576 | break; |
1da177e4 | 577 | } |
97894cda TG |
578 | |
579 | if (!silly--) { | |
1da177e4 LT |
580 | printk(KERN_WARNING |
581 | "Infinite loop in Virtual Unit Chain 0x%x\n", | |
582 | thisVUC); | |
70ec3bb8 | 583 | return BLOCK_NIL; |
1da177e4 LT |
584 | } |
585 | ||
586 | /* Skip to next block in chain */ | |
587 | writeEUN = nftl->ReplUnitTable[writeEUN]; | |
588 | } | |
589 | ||
97894cda | 590 | /* OK. We didn't find one in the existing chain, or there |
1da177e4 LT |
591 | is no existing chain. */ |
592 | ||
593 | /* Try to find an already-free block */ | |
594 | writeEUN = NFTL_findfreeblock(nftl, 0); | |
595 | ||
596 | if (writeEUN == BLOCK_NIL) { | |
597 | /* That didn't work - there were no free blocks just | |
598 | waiting to be picked up. We're going to have to fold | |
599 | a chain to make room. | |
600 | */ | |
601 | ||
602 | /* First remember the start of this chain */ | |
603 | //u16 startEUN = nftl->EUNtable[thisVUC]; | |
97894cda | 604 | |
1da177e4 | 605 | //printk("Write to VirtualUnitChain %d, calling makefreeblock()\n", thisVUC); |
70ec3bb8 | 606 | writeEUN = NFTL_makefreeblock(nftl, BLOCK_NIL); |
1da177e4 LT |
607 | |
608 | if (writeEUN == BLOCK_NIL) { | |
97894cda | 609 | /* OK, we accept that the above comment is |
1da177e4 LT |
610 | lying - there may have been free blocks |
611 | last time we called NFTL_findfreeblock(), | |
612 | but they are reserved for when we're | |
613 | desperate. Well, now we're desperate. | |
614 | */ | |
615 | DEBUG(MTD_DEBUG_LEVEL1, "Using desperate==1 to find free EUN to accommodate write to VUC %d\n", thisVUC); | |
616 | writeEUN = NFTL_findfreeblock(nftl, 1); | |
617 | } | |
618 | if (writeEUN == BLOCK_NIL) { | |
619 | /* Ouch. This should never happen - we should | |
97894cda TG |
620 | always be able to make some room somehow. |
621 | If we get here, we've allocated more storage | |
1da177e4 LT |
622 | space than actual media, or our makefreeblock |
623 | routine is missing something. | |
624 | */ | |
625 | printk(KERN_WARNING "Cannot make free space.\n"); | |
626 | return BLOCK_NIL; | |
97894cda | 627 | } |
1da177e4 LT |
628 | //printk("Restarting scan\n"); |
629 | lastEUN = BLOCK_NIL; | |
630 | continue; | |
631 | } | |
632 | ||
633 | /* We've found a free block. Insert it into the chain. */ | |
97894cda | 634 | |
1da177e4 | 635 | if (lastEUN != BLOCK_NIL) { |
f4a43cfc | 636 | thisVUC |= 0x8000; /* It's a replacement block */ |
1da177e4 | 637 | } else { |
f4a43cfc TG |
638 | /* The first block in a new chain */ |
639 | nftl->EUNtable[thisVUC] = writeEUN; | |
1da177e4 LT |
640 | } |
641 | ||
642 | /* set up the actual EUN we're writing into */ | |
643 | /* Both in our cache... */ | |
644 | nftl->ReplUnitTable[writeEUN] = BLOCK_NIL; | |
645 | ||
646 | /* ... and on the flash itself */ | |
8593fbc6 | 647 | nftl_read_oob(mtd, writeEUN * nftl->EraseSize + 8, 8, |
f4a43cfc | 648 | &retlen, (char *)&oob.u); |
1da177e4 LT |
649 | |
650 | oob.u.a.VirtUnitNum = oob.u.a.SpareVirtUnitNum = cpu_to_le16(thisVUC); | |
651 | ||
8593fbc6 | 652 | nftl_write_oob(mtd, writeEUN * nftl->EraseSize + 8, 8, |
f4a43cfc | 653 | &retlen, (char *)&oob.u); |
1da177e4 | 654 | |
f4a43cfc | 655 | /* we link the new block to the chain only after the |
1da177e4 LT |
656 | block is ready. It avoids the case where the chain |
657 | could point to a free block */ | |
f4a43cfc | 658 | if (lastEUN != BLOCK_NIL) { |
1da177e4 LT |
659 | /* Both in our cache... */ |
660 | nftl->ReplUnitTable[lastEUN] = writeEUN; | |
661 | /* ... and on the flash itself */ | |
8593fbc6 | 662 | nftl_read_oob(mtd, (lastEUN * nftl->EraseSize) + 8, |
f4a43cfc | 663 | 8, &retlen, (char *)&oob.u); |
1da177e4 LT |
664 | |
665 | oob.u.a.ReplUnitNum = oob.u.a.SpareReplUnitNum | |
666 | = cpu_to_le16(writeEUN); | |
667 | ||
8593fbc6 | 668 | nftl_write_oob(mtd, (lastEUN * nftl->EraseSize) + 8, |
f4a43cfc | 669 | 8, &retlen, (char *)&oob.u); |
1da177e4 LT |
670 | } |
671 | ||
672 | return writeEUN; | |
673 | ||
674 | } while (silly2--); | |
675 | ||
676 | printk(KERN_WARNING "Error folding to make room for Virtual Unit Chain 0x%x\n", | |
677 | thisVUC); | |
70ec3bb8 | 678 | return BLOCK_NIL; |
1da177e4 LT |
679 | } |
680 | ||
681 | static int nftl_writeblock(struct mtd_blktrans_dev *mbd, unsigned long block, | |
682 | char *buffer) | |
683 | { | |
684 | struct NFTLrecord *nftl = (void *)mbd; | |
685 | u16 writeEUN; | |
686 | unsigned long blockofs = (block * 512) & (nftl->EraseSize - 1); | |
687 | size_t retlen; | |
688 | struct nftl_oob oob; | |
689 | ||
690 | writeEUN = NFTL_findwriteunit(nftl, block); | |
691 | ||
692 | if (writeEUN == BLOCK_NIL) { | |
693 | printk(KERN_WARNING | |
694 | "NFTL_writeblock(): Cannot find block to write to\n"); | |
695 | /* If we _still_ haven't got a block to use, we're screwed */ | |
696 | return 1; | |
697 | } | |
698 | ||
699 | memset(&oob, 0xff, sizeof(struct nftl_oob)); | |
700 | oob.b.Status = oob.b.Status1 = SECTOR_USED; | |
1da177e4 | 701 | |
8593fbc6 TG |
702 | nftl_write(nftl->mbd.mtd, (writeEUN * nftl->EraseSize) + blockofs, |
703 | 512, &retlen, (char *)buffer, (char *)&oob); | |
1da177e4 LT |
704 | return 0; |
705 | } | |
706 | #endif /* CONFIG_NFTL_RW */ | |
707 | ||
708 | static int nftl_readblock(struct mtd_blktrans_dev *mbd, unsigned long block, | |
709 | char *buffer) | |
710 | { | |
711 | struct NFTLrecord *nftl = (void *)mbd; | |
f4a43cfc | 712 | struct mtd_info *mtd = nftl->mbd.mtd; |
1da177e4 LT |
713 | u16 lastgoodEUN; |
714 | u16 thisEUN = nftl->EUNtable[block / (nftl->EraseSize / 512)]; | |
715 | unsigned long blockofs = (block * 512) & (nftl->EraseSize - 1); | |
f4a43cfc | 716 | unsigned int status; |
1da177e4 | 717 | int silly = MAX_LOOPS; |
f4a43cfc TG |
718 | size_t retlen; |
719 | struct nftl_bci bci; | |
1da177e4 LT |
720 | |
721 | lastgoodEUN = BLOCK_NIL; | |
722 | ||
f4a43cfc | 723 | if (thisEUN != BLOCK_NIL) { |
1da177e4 | 724 | while (thisEUN < nftl->nb_blocks) { |
8593fbc6 | 725 | if (nftl_read_oob(mtd, (thisEUN * nftl->EraseSize) + |
f4a43cfc TG |
726 | blockofs, 8, &retlen, |
727 | (char *)&bci) < 0) | |
1da177e4 LT |
728 | status = SECTOR_IGNORE; |
729 | else | |
730 | status = bci.Status | bci.Status1; | |
731 | ||
732 | switch (status) { | |
733 | case SECTOR_FREE: | |
734 | /* no modification of a sector should follow a free sector */ | |
735 | goto the_end; | |
736 | case SECTOR_DELETED: | |
737 | lastgoodEUN = BLOCK_NIL; | |
738 | break; | |
739 | case SECTOR_USED: | |
740 | lastgoodEUN = thisEUN; | |
741 | break; | |
742 | case SECTOR_IGNORE: | |
743 | break; | |
744 | default: | |
745 | printk("Unknown status for block %ld in EUN %d: %x\n", | |
746 | block, thisEUN, status); | |
747 | break; | |
748 | } | |
749 | ||
750 | if (!silly--) { | |
751 | printk(KERN_WARNING "Infinite loop in Virtual Unit Chain 0x%lx\n", | |
752 | block / (nftl->EraseSize / 512)); | |
753 | return 1; | |
754 | } | |
755 | thisEUN = nftl->ReplUnitTable[thisEUN]; | |
756 | } | |
f4a43cfc | 757 | } |
1da177e4 LT |
758 | |
759 | the_end: | |
760 | if (lastgoodEUN == BLOCK_NIL) { | |
761 | /* the requested block is not on the media, return all 0x00 */ | |
762 | memset(buffer, 0, 512); | |
763 | } else { | |
764 | loff_t ptr = (lastgoodEUN * nftl->EraseSize) + blockofs; | |
765 | size_t retlen; | |
9a1fcdfd TG |
766 | int res = mtd->read(mtd, ptr, 512, &retlen, buffer); |
767 | ||
768 | if (res < 0 && res != -EUCLEAN) | |
1da177e4 LT |
769 | return -EIO; |
770 | } | |
771 | return 0; | |
772 | } | |
773 | ||
774 | static int nftl_getgeo(struct mtd_blktrans_dev *dev, struct hd_geometry *geo) | |
775 | { | |
776 | struct NFTLrecord *nftl = (void *)dev; | |
777 | ||
778 | geo->heads = nftl->heads; | |
779 | geo->sectors = nftl->sectors; | |
780 | geo->cylinders = nftl->cylinders; | |
781 | ||
782 | return 0; | |
783 | } | |
784 | ||
785 | /**************************************************************************** | |
786 | * | |
787 | * Module stuff | |
788 | * | |
789 | ****************************************************************************/ | |
790 | ||
791 | ||
792 | static struct mtd_blktrans_ops nftl_tr = { | |
793 | .name = "nftl", | |
794 | .major = NFTL_MAJOR, | |
795 | .part_bits = NFTL_PARTN_BITS, | |
19187672 | 796 | .blksize = 512, |
1da177e4 LT |
797 | .getgeo = nftl_getgeo, |
798 | .readsect = nftl_readblock, | |
799 | #ifdef CONFIG_NFTL_RW | |
800 | .writesect = nftl_writeblock, | |
801 | #endif | |
802 | .add_mtd = nftl_add_mtd, | |
803 | .remove_dev = nftl_remove_dev, | |
804 | .owner = THIS_MODULE, | |
805 | }; | |
806 | ||
1da177e4 LT |
807 | static int __init init_nftl(void) |
808 | { | |
1da177e4 LT |
809 | return register_mtd_blktrans(&nftl_tr); |
810 | } | |
811 | ||
812 | static void __exit cleanup_nftl(void) | |
813 | { | |
814 | deregister_mtd_blktrans(&nftl_tr); | |
815 | } | |
816 | ||
817 | module_init(init_nftl); | |
818 | module_exit(cleanup_nftl); | |
819 | ||
820 | MODULE_LICENSE("GPL"); | |
821 | MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>, Fabrice Bellard <fabrice.bellard@netgem.com> et al."); | |
822 | MODULE_DESCRIPTION("Support code for NAND Flash Translation Layer, used on M-Systems DiskOnChip 2000 and Millennium"); | |
e7f52163 | 823 | MODULE_ALIAS_BLOCKDEV_MAJOR(NFTL_MAJOR); |