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