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