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> */ | |
97894cda | 4 | /* $Id: nftlcore.c,v 1.98 2005/11/07 11:14:21 gleixner Exp $ */ |
1da177e4 LT |
5 | |
6 | /* | |
7 | The contents of this file are distributed under the GNU General | |
8 | Public License version 2. The author places no additional | |
9 | restrictions of any kind on it. | |
10 | */ | |
11 | ||
12 | #define PRERELEASE | |
13 | ||
1da177e4 LT |
14 | #include <linux/kernel.h> |
15 | #include <linux/module.h> | |
16 | #include <asm/errno.h> | |
17 | #include <asm/io.h> | |
18 | #include <asm/uaccess.h> | |
19 | #include <linux/miscdevice.h> | |
1da177e4 LT |
20 | #include <linux/delay.h> |
21 | #include <linux/slab.h> | |
1da177e4 LT |
22 | #include <linux/init.h> |
23 | #include <linux/hdreg.h> | |
24 | ||
25 | #include <linux/kmod.h> | |
26 | #include <linux/mtd/mtd.h> | |
27 | #include <linux/mtd/nand.h> | |
28 | #include <linux/mtd/nftl.h> | |
29 | #include <linux/mtd/blktrans.h> | |
30 | ||
31 | /* maximum number of loops while examining next block, to have a | |
32 | chance to detect consistency problems (they should never happen | |
33 | because of the checks done in the mounting */ | |
34 | ||
35 | #define MAX_LOOPS 10000 | |
36 | ||
37 | ||
38 | static void nftl_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd) | |
39 | { | |
40 | struct NFTLrecord *nftl; | |
41 | unsigned long temp; | |
42 | ||
43 | if (mtd->type != MTD_NANDFLASH) | |
44 | return; | |
45 | /* OK, this is moderately ugly. But probably safe. Alternatives? */ | |
46 | if (memcmp(mtd->name, "DiskOnChip", 10)) | |
47 | return; | |
48 | ||
49 | if (!mtd->block_isbad) { | |
50 | printk(KERN_ERR | |
51 | "NFTL no longer supports the old DiskOnChip drivers loaded via docprobe.\n" | |
52 | "Please use the new diskonchip driver under the NAND subsystem.\n"); | |
53 | return; | |
54 | } | |
55 | ||
56 | DEBUG(MTD_DEBUG_LEVEL1, "NFTL: add_mtd for %s\n", mtd->name); | |
57 | ||
95b93a0c | 58 | nftl = kzalloc(sizeof(struct NFTLrecord), GFP_KERNEL); |
1da177e4 LT |
59 | |
60 | if (!nftl) { | |
61 | printk(KERN_WARNING "NFTL: out of memory for data structures\n"); | |
62 | return; | |
63 | } | |
1da177e4 LT |
64 | |
65 | nftl->mbd.mtd = mtd; | |
66 | nftl->mbd.devnum = -1; | |
19187672 | 67 | |
1da177e4 | 68 | nftl->mbd.tr = tr; |
1da177e4 LT |
69 | |
70 | if (NFTL_mount(nftl) < 0) { | |
71 | printk(KERN_WARNING "NFTL: could not mount device\n"); | |
72 | kfree(nftl); | |
73 | return; | |
74 | } | |
75 | ||
76 | /* OK, it's a new one. Set up all the data structures. */ | |
77 | ||
78 | /* Calculate geometry */ | |
79 | nftl->cylinders = 1024; | |
80 | nftl->heads = 16; | |
81 | ||
82 | temp = nftl->cylinders * nftl->heads; | |
83 | nftl->sectors = nftl->mbd.size / temp; | |
84 | if (nftl->mbd.size % temp) { | |
85 | nftl->sectors++; | |
86 | temp = nftl->cylinders * nftl->sectors; | |
87 | nftl->heads = nftl->mbd.size / temp; | |
88 | ||
89 | if (nftl->mbd.size % temp) { | |
90 | nftl->heads++; | |
91 | temp = nftl->heads * nftl->sectors; | |
92 | nftl->cylinders = nftl->mbd.size / temp; | |
93 | } | |
94 | } | |
95 | ||
96 | if (nftl->mbd.size != nftl->heads * nftl->cylinders * nftl->sectors) { | |
97 | /* | |
97894cda | 98 | Oh no we don't have |
1da177e4 LT |
99 | mbd.size == heads * cylinders * sectors |
100 | */ | |
101 | printk(KERN_WARNING "NFTL: cannot calculate a geometry to " | |
102 | "match size of 0x%lx.\n", nftl->mbd.size); | |
103 | printk(KERN_WARNING "NFTL: using C:%d H:%d S:%d " | |
104 | "(== 0x%lx sects)\n", | |
97894cda | 105 | nftl->cylinders, nftl->heads , nftl->sectors, |
1da177e4 LT |
106 | (long)nftl->cylinders * (long)nftl->heads * |
107 | (long)nftl->sectors ); | |
108 | } | |
109 | ||
110 | if (add_mtd_blktrans_dev(&nftl->mbd)) { | |
fa671646 JJ |
111 | kfree(nftl->ReplUnitTable); |
112 | kfree(nftl->EUNtable); | |
1da177e4 LT |
113 | kfree(nftl); |
114 | return; | |
115 | } | |
116 | #ifdef PSYCHO_DEBUG | |
117 | printk(KERN_INFO "NFTL: Found new nftl%c\n", nftl->mbd.devnum + 'a'); | |
118 | #endif | |
119 | } | |
120 | ||
121 | static void nftl_remove_dev(struct mtd_blktrans_dev *dev) | |
122 | { | |
123 | struct NFTLrecord *nftl = (void *)dev; | |
124 | ||
125 | DEBUG(MTD_DEBUG_LEVEL1, "NFTL: remove_dev (i=%d)\n", dev->devnum); | |
126 | ||
127 | del_mtd_blktrans_dev(dev); | |
fa671646 JJ |
128 | kfree(nftl->ReplUnitTable); |
129 | kfree(nftl->EUNtable); | |
1da177e4 LT |
130 | kfree(nftl); |
131 | } | |
132 | ||
8593fbc6 TG |
133 | /* |
134 | * Read oob data from flash | |
135 | */ | |
136 | int nftl_read_oob(struct mtd_info *mtd, loff_t offs, size_t len, | |
137 | size_t *retlen, uint8_t *buf) | |
138 | { | |
139 | struct mtd_oob_ops ops; | |
140 | int res; | |
141 | ||
142 | ops.mode = MTD_OOB_PLACE; | |
143 | ops.ooboffs = offs & (mtd->writesize - 1); | |
144 | ops.ooblen = len; | |
145 | ops.oobbuf = buf; | |
146 | ops.datbuf = NULL; | |
8593fbc6 TG |
147 | |
148 | res = mtd->read_oob(mtd, offs & ~(mtd->writesize - 1), &ops); | |
7014568b | 149 | *retlen = ops.oobretlen; |
8593fbc6 TG |
150 | return res; |
151 | } | |
152 | ||
153 | /* | |
154 | * Write oob data to flash | |
155 | */ | |
156 | int nftl_write_oob(struct mtd_info *mtd, loff_t offs, size_t len, | |
157 | size_t *retlen, uint8_t *buf) | |
158 | { | |
159 | struct mtd_oob_ops ops; | |
160 | int res; | |
161 | ||
162 | ops.mode = MTD_OOB_PLACE; | |
163 | ops.ooboffs = offs & (mtd->writesize - 1); | |
164 | ops.ooblen = len; | |
165 | ops.oobbuf = buf; | |
166 | ops.datbuf = NULL; | |
8593fbc6 TG |
167 | |
168 | res = mtd->write_oob(mtd, offs & ~(mtd->writesize - 1), &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 | { | |
181 | struct mtd_oob_ops ops; | |
182 | int res; | |
183 | ||
184 | ops.mode = MTD_OOB_PLACE; | |
185 | ops.ooboffs = offs; | |
186 | ops.ooblen = mtd->oobsize; | |
187 | ops.oobbuf = oob; | |
188 | ops.datbuf = buf; | |
189 | ops.len = len; | |
190 | ||
191 | res = mtd->write_oob(mtd, offs & ~(mtd->writesize - 1), &ops); | |
192 | *retlen = ops.retlen; | |
193 | return res; | |
194 | } | |
195 | ||
1da177e4 LT |
196 | /* Actual NFTL access routines */ |
197 | /* NFTL_findfreeblock: Find a free Erase Unit on the NFTL partition. This function is used | |
198 | * when the give Virtual Unit Chain | |
199 | */ | |
200 | static u16 NFTL_findfreeblock(struct NFTLrecord *nftl, int desperate ) | |
201 | { | |
202 | /* For a given Virtual Unit Chain: find or create a free block and | |
203 | add it to the chain */ | |
204 | /* We're passed the number of the last EUN in the chain, to save us from | |
205 | having to look it up again */ | |
206 | u16 pot = nftl->LastFreeEUN; | |
207 | int silly = nftl->nb_blocks; | |
208 | ||
209 | /* Normally, we force a fold to happen before we run out of free blocks completely */ | |
210 | if (!desperate && nftl->numfreeEUNs < 2) { | |
211 | DEBUG(MTD_DEBUG_LEVEL1, "NFTL_findfreeblock: there are too few free EUNs\n"); | |
212 | return 0xffff; | |
213 | } | |
214 | ||
215 | /* Scan for a free block */ | |
216 | do { | |
217 | if (nftl->ReplUnitTable[pot] == BLOCK_FREE) { | |
218 | nftl->LastFreeEUN = pot; | |
219 | nftl->numfreeEUNs--; | |
220 | return pot; | |
221 | } | |
222 | ||
223 | /* This will probably point to the MediaHdr unit itself, | |
224 | right at the beginning of the partition. But that unit | |
225 | (and the backup unit too) should have the UCI set | |
226 | up so that it's not selected for overwriting */ | |
227 | if (++pot > nftl->lastEUN) | |
228 | pot = le16_to_cpu(nftl->MediaHdr.FirstPhysicalEUN); | |
229 | ||
230 | if (!silly--) { | |
231 | printk("Argh! No free blocks found! LastFreeEUN = %d, " | |
97894cda | 232 | "FirstEUN = %d\n", nftl->LastFreeEUN, |
1da177e4 LT |
233 | le16_to_cpu(nftl->MediaHdr.FirstPhysicalEUN)); |
234 | return 0xffff; | |
235 | } | |
236 | } while (pot != nftl->LastFreeEUN); | |
237 | ||
238 | return 0xffff; | |
239 | } | |
240 | ||
241 | static u16 NFTL_foldchain (struct NFTLrecord *nftl, unsigned thisVUC, unsigned pendingblock ) | |
242 | { | |
f4a43cfc | 243 | struct mtd_info *mtd = nftl->mbd.mtd; |
1da177e4 LT |
244 | u16 BlockMap[MAX_SECTORS_PER_UNIT]; |
245 | unsigned char BlockLastState[MAX_SECTORS_PER_UNIT]; | |
246 | unsigned char BlockFreeFound[MAX_SECTORS_PER_UNIT]; | |
247 | unsigned int thisEUN; | |
248 | int block; | |
249 | int silly; | |
250 | unsigned int targetEUN; | |
251 | struct nftl_oob oob; | |
252 | int inplace = 1; | |
f4a43cfc | 253 | size_t retlen; |
1da177e4 LT |
254 | |
255 | memset(BlockMap, 0xff, sizeof(BlockMap)); | |
256 | memset(BlockFreeFound, 0, sizeof(BlockFreeFound)); | |
257 | ||
258 | thisEUN = nftl->EUNtable[thisVUC]; | |
259 | ||
260 | if (thisEUN == BLOCK_NIL) { | |
261 | printk(KERN_WARNING "Trying to fold non-existent " | |
262 | "Virtual Unit Chain %d!\n", thisVUC); | |
263 | return BLOCK_NIL; | |
264 | } | |
97894cda | 265 | |
1da177e4 LT |
266 | /* Scan to find the Erase Unit which holds the actual data for each |
267 | 512-byte block within the Chain. | |
268 | */ | |
f4a43cfc | 269 | silly = MAX_LOOPS; |
1da177e4 LT |
270 | targetEUN = BLOCK_NIL; |
271 | while (thisEUN <= nftl->lastEUN ) { | |
f4a43cfc | 272 | unsigned int status, foldmark; |
1da177e4 LT |
273 | |
274 | targetEUN = thisEUN; | |
275 | for (block = 0; block < nftl->EraseSize / 512; block ++) { | |
8593fbc6 | 276 | nftl_read_oob(mtd, (thisEUN * nftl->EraseSize) + |
f4a43cfc TG |
277 | (block * 512), 16 , &retlen, |
278 | (char *)&oob); | |
1da177e4 | 279 | if (block == 2) { |
f4a43cfc TG |
280 | foldmark = oob.u.c.FoldMark | oob.u.c.FoldMark1; |
281 | if (foldmark == FOLD_MARK_IN_PROGRESS) { | |
282 | DEBUG(MTD_DEBUG_LEVEL1, | |
283 | "Write Inhibited on EUN %d\n", thisEUN); | |
1da177e4 LT |
284 | inplace = 0; |
285 | } else { | |
286 | /* There's no other reason not to do inplace, | |
287 | except ones that come later. So we don't need | |
288 | to preserve inplace */ | |
289 | inplace = 1; | |
290 | } | |
291 | } | |
f4a43cfc | 292 | status = oob.b.Status | oob.b.Status1; |
1da177e4 LT |
293 | BlockLastState[block] = status; |
294 | ||
295 | switch(status) { | |
296 | case SECTOR_FREE: | |
297 | BlockFreeFound[block] = 1; | |
298 | break; | |
299 | ||
300 | case SECTOR_USED: | |
301 | if (!BlockFreeFound[block]) | |
302 | BlockMap[block] = thisEUN; | |
303 | else | |
97894cda | 304 | printk(KERN_WARNING |
1da177e4 LT |
305 | "SECTOR_USED found after SECTOR_FREE " |
306 | "in Virtual Unit Chain %d for block %d\n", | |
307 | thisVUC, block); | |
308 | break; | |
309 | case SECTOR_DELETED: | |
310 | if (!BlockFreeFound[block]) | |
311 | BlockMap[block] = BLOCK_NIL; | |
312 | else | |
97894cda | 313 | printk(KERN_WARNING |
1da177e4 LT |
314 | "SECTOR_DELETED found after SECTOR_FREE " |
315 | "in Virtual Unit Chain %d for block %d\n", | |
316 | thisVUC, block); | |
317 | break; | |
318 | ||
319 | case SECTOR_IGNORE: | |
320 | break; | |
321 | default: | |
322 | printk("Unknown status for block %d in EUN %d: %x\n", | |
323 | block, thisEUN, status); | |
324 | } | |
325 | } | |
326 | ||
327 | if (!silly--) { | |
328 | printk(KERN_WARNING "Infinite loop in Virtual Unit Chain 0x%x\n", | |
329 | thisVUC); | |
330 | return BLOCK_NIL; | |
331 | } | |
97894cda | 332 | |
1da177e4 LT |
333 | thisEUN = nftl->ReplUnitTable[thisEUN]; |
334 | } | |
335 | ||
336 | if (inplace) { | |
337 | /* We're being asked to be a fold-in-place. Check | |
338 | that all blocks which actually have data associated | |
97894cda | 339 | with them (i.e. BlockMap[block] != BLOCK_NIL) are |
1da177e4 LT |
340 | either already present or SECTOR_FREE in the target |
341 | block. If not, we're going to have to fold out-of-place | |
342 | anyway. | |
343 | */ | |
344 | for (block = 0; block < nftl->EraseSize / 512 ; block++) { | |
345 | if (BlockLastState[block] != SECTOR_FREE && | |
346 | BlockMap[block] != BLOCK_NIL && | |
347 | BlockMap[block] != targetEUN) { | |
348 | DEBUG(MTD_DEBUG_LEVEL1, "Setting inplace to 0. VUC %d, " | |
349 | "block %d was %x lastEUN, " | |
350 | "and is in EUN %d (%s) %d\n", | |
351 | thisVUC, block, BlockLastState[block], | |
97894cda | 352 | BlockMap[block], |
1da177e4 LT |
353 | BlockMap[block]== targetEUN ? "==" : "!=", |
354 | targetEUN); | |
355 | inplace = 0; | |
356 | break; | |
357 | } | |
358 | } | |
359 | ||
360 | if (pendingblock >= (thisVUC * (nftl->EraseSize / 512)) && | |
361 | pendingblock < ((thisVUC + 1)* (nftl->EraseSize / 512)) && | |
362 | BlockLastState[pendingblock - (thisVUC * (nftl->EraseSize / 512))] != | |
363 | SECTOR_FREE) { | |
364 | DEBUG(MTD_DEBUG_LEVEL1, "Pending write not free in EUN %d. " | |
365 | "Folding out of place.\n", targetEUN); | |
366 | inplace = 0; | |
367 | } | |
368 | } | |
97894cda | 369 | |
1da177e4 LT |
370 | if (!inplace) { |
371 | DEBUG(MTD_DEBUG_LEVEL1, "Cannot fold Virtual Unit Chain %d in place. " | |
372 | "Trying out-of-place\n", thisVUC); | |
373 | /* We need to find a targetEUN to fold into. */ | |
374 | targetEUN = NFTL_findfreeblock(nftl, 1); | |
375 | if (targetEUN == BLOCK_NIL) { | |
97894cda | 376 | /* Ouch. Now we're screwed. We need to do a |
1da177e4 LT |
377 | fold-in-place of another chain to make room |
378 | for this one. We need a better way of selecting | |
97894cda | 379 | which chain to fold, because makefreeblock will |
1da177e4 LT |
380 | only ask us to fold the same one again. |
381 | */ | |
382 | printk(KERN_WARNING | |
383 | "NFTL_findfreeblock(desperate) returns 0xffff.\n"); | |
384 | return BLOCK_NIL; | |
385 | } | |
386 | } else { | |
f4a43cfc TG |
387 | /* We put a fold mark in the chain we are folding only if we |
388 | fold in place to help the mount check code. If we do not fold in | |
389 | place, it is possible to find the valid chain by selecting the | |
390 | longer one */ | |
391 | oob.u.c.FoldMark = oob.u.c.FoldMark1 = cpu_to_le16(FOLD_MARK_IN_PROGRESS); | |
392 | oob.u.c.unused = 0xffffffff; | |
8593fbc6 | 393 | nftl_write_oob(mtd, (nftl->EraseSize * targetEUN) + 2 * 512 + 8, |
f4a43cfc TG |
394 | 8, &retlen, (char *)&oob.u); |
395 | } | |
1da177e4 LT |
396 | |
397 | /* OK. We now know the location of every block in the Virtual Unit Chain, | |
398 | and the Erase Unit into which we are supposed to be copying. | |
399 | Go for it. | |
400 | */ | |
401 | DEBUG(MTD_DEBUG_LEVEL1,"Folding chain %d into unit %d\n", thisVUC, targetEUN); | |
402 | for (block = 0; block < nftl->EraseSize / 512 ; block++) { | |
403 | unsigned char movebuf[512]; | |
404 | int ret; | |
405 | ||
406 | /* If it's in the target EUN already, or if it's pending write, do nothing */ | |
407 | if (BlockMap[block] == targetEUN || | |
408 | (pendingblock == (thisVUC * (nftl->EraseSize / 512) + block))) { | |
409 | continue; | |
410 | } | |
411 | ||
f4a43cfc | 412 | /* copy only in non free block (free blocks can only |
1da177e4 | 413 | happen in case of media errors or deleted blocks) */ |
f4a43cfc TG |
414 | if (BlockMap[block] == BLOCK_NIL) |
415 | continue; | |
416 | ||
417 | ret = mtd->read(mtd, (nftl->EraseSize * BlockMap[block]) + (block * 512), | |
418 | 512, &retlen, movebuf); | |
9a1fcdfd | 419 | if (ret < 0 && ret != -EUCLEAN) { |
f4a43cfc TG |
420 | ret = mtd->read(mtd, (nftl->EraseSize * BlockMap[block]) |
421 | + (block * 512), 512, &retlen, | |
422 | movebuf); | |
423 | if (ret != -EIO) | |
424 | printk("Error went away on retry.\n"); | |
425 | } | |
1da177e4 LT |
426 | memset(&oob, 0xff, sizeof(struct nftl_oob)); |
427 | oob.b.Status = oob.b.Status1 = SECTOR_USED; | |
9223a456 | 428 | |
8593fbc6 TG |
429 | nftl_write(nftl->mbd.mtd, (nftl->EraseSize * targetEUN) + |
430 | (block * 512), 512, &retlen, movebuf, (char *)&oob); | |
1da177e4 | 431 | } |
97894cda | 432 | |
f4a43cfc TG |
433 | /* add the header so that it is now a valid chain */ |
434 | oob.u.a.VirtUnitNum = oob.u.a.SpareVirtUnitNum = cpu_to_le16(thisVUC); | |
435 | oob.u.a.ReplUnitNum = oob.u.a.SpareReplUnitNum = 0xffff; | |
97894cda | 436 | |
8593fbc6 | 437 | nftl_write_oob(mtd, (nftl->EraseSize * targetEUN) + 8, |
f4a43cfc | 438 | 8, &retlen, (char *)&oob.u); |
1da177e4 LT |
439 | |
440 | /* OK. We've moved the whole lot into the new block. Now we have to free the original blocks. */ | |
441 | ||
97894cda | 442 | /* At this point, we have two different chains for this Virtual Unit, and no way to tell |
1da177e4 LT |
443 | them apart. If we crash now, we get confused. However, both contain the same data, so we |
444 | shouldn't actually lose data in this case. It's just that when we load up on a medium which | |
445 | has duplicate chains, we need to free one of the chains because it's not necessary any more. | |
446 | */ | |
447 | thisEUN = nftl->EUNtable[thisVUC]; | |
448 | DEBUG(MTD_DEBUG_LEVEL1,"Want to erase\n"); | |
449 | ||
97894cda | 450 | /* For each block in the old chain (except the targetEUN of course), |
1da177e4 LT |
451 | free it and make it available for future use */ |
452 | while (thisEUN <= nftl->lastEUN && thisEUN != targetEUN) { | |
453 | unsigned int EUNtmp; | |
454 | ||
f4a43cfc | 455 | EUNtmp = nftl->ReplUnitTable[thisEUN]; |
1da177e4 | 456 | |
f4a43cfc | 457 | if (NFTL_formatblock(nftl, thisEUN) < 0) { |
1da177e4 LT |
458 | /* could not erase : mark block as reserved |
459 | */ | |
460 | nftl->ReplUnitTable[thisEUN] = BLOCK_RESERVED; | |
f4a43cfc | 461 | } else { |
1da177e4 LT |
462 | /* correctly erased : mark it as free */ |
463 | nftl->ReplUnitTable[thisEUN] = BLOCK_FREE; | |
464 | nftl->numfreeEUNs++; | |
f4a43cfc TG |
465 | } |
466 | thisEUN = EUNtmp; | |
1da177e4 | 467 | } |
97894cda | 468 | |
1da177e4 LT |
469 | /* Make this the new start of chain for thisVUC */ |
470 | nftl->ReplUnitTable[targetEUN] = BLOCK_NIL; | |
471 | nftl->EUNtable[thisVUC] = targetEUN; | |
472 | ||
473 | return targetEUN; | |
474 | } | |
475 | ||
476 | static u16 NFTL_makefreeblock( struct NFTLrecord *nftl , unsigned pendingblock) | |
477 | { | |
97894cda | 478 | /* This is the part that needs some cleverness applied. |
1da177e4 LT |
479 | For now, I'm doing the minimum applicable to actually |
480 | get the thing to work. | |
481 | Wear-levelling and other clever stuff needs to be implemented | |
482 | and we also need to do some assessment of the results when | |
483 | the system loses power half-way through the routine. | |
484 | */ | |
485 | u16 LongestChain = 0; | |
486 | u16 ChainLength = 0, thislen; | |
487 | u16 chain, EUN; | |
488 | ||
489 | for (chain = 0; chain < le32_to_cpu(nftl->MediaHdr.FormattedSize) / nftl->EraseSize; chain++) { | |
490 | EUN = nftl->EUNtable[chain]; | |
491 | thislen = 0; | |
492 | ||
493 | while (EUN <= nftl->lastEUN) { | |
494 | thislen++; | |
495 | //printk("VUC %d reaches len %d with EUN %d\n", chain, thislen, EUN); | |
496 | EUN = nftl->ReplUnitTable[EUN] & 0x7fff; | |
497 | if (thislen > 0xff00) { | |
498 | printk("Endless loop in Virtual Chain %d: Unit %x\n", | |
499 | chain, EUN); | |
500 | } | |
501 | if (thislen > 0xff10) { | |
502 | /* Actually, don't return failure. Just ignore this chain and | |
503 | get on with it. */ | |
504 | thislen = 0; | |
505 | break; | |
506 | } | |
507 | } | |
508 | ||
509 | if (thislen > ChainLength) { | |
510 | //printk("New longest chain is %d with length %d\n", chain, thislen); | |
511 | ChainLength = thislen; | |
512 | LongestChain = chain; | |
513 | } | |
514 | } | |
515 | ||
516 | if (ChainLength < 2) { | |
517 | printk(KERN_WARNING "No Virtual Unit Chains available for folding. " | |
518 | "Failing request\n"); | |
519 | return 0xffff; | |
520 | } | |
521 | ||
522 | return NFTL_foldchain (nftl, LongestChain, pendingblock); | |
523 | } | |
524 | ||
97894cda | 525 | /* NFTL_findwriteunit: Return the unit number into which we can write |
1da177e4 LT |
526 | for this block. Make it available if it isn't already |
527 | */ | |
528 | static inline u16 NFTL_findwriteunit(struct NFTLrecord *nftl, unsigned block) | |
529 | { | |
530 | u16 lastEUN; | |
531 | u16 thisVUC = block / (nftl->EraseSize / 512); | |
f4a43cfc | 532 | struct mtd_info *mtd = nftl->mbd.mtd; |
1da177e4 LT |
533 | unsigned int writeEUN; |
534 | unsigned long blockofs = (block * 512) & (nftl->EraseSize -1); | |
535 | size_t retlen; | |
536 | int silly, silly2 = 3; | |
537 | struct nftl_oob oob; | |
538 | ||
539 | do { | |
540 | /* Scan the media to find a unit in the VUC which has | |
541 | a free space for the block in question. | |
542 | */ | |
543 | ||
97894cda | 544 | /* This condition catches the 0x[7f]fff cases, as well as |
1da177e4 LT |
545 | being a sanity check for past-end-of-media access |
546 | */ | |
547 | lastEUN = BLOCK_NIL; | |
548 | writeEUN = nftl->EUNtable[thisVUC]; | |
f4a43cfc | 549 | silly = MAX_LOOPS; |
1da177e4 LT |
550 | while (writeEUN <= nftl->lastEUN) { |
551 | struct nftl_bci bci; | |
552 | size_t retlen; | |
f4a43cfc | 553 | unsigned int status; |
1da177e4 LT |
554 | |
555 | lastEUN = writeEUN; | |
556 | ||
8593fbc6 | 557 | nftl_read_oob(mtd, |
f4a43cfc TG |
558 | (writeEUN * nftl->EraseSize) + blockofs, |
559 | 8, &retlen, (char *)&bci); | |
97894cda | 560 | |
1da177e4 LT |
561 | DEBUG(MTD_DEBUG_LEVEL2, "Status of block %d in EUN %d is %x\n", |
562 | block , writeEUN, le16_to_cpu(bci.Status)); | |
563 | ||
f4a43cfc | 564 | status = bci.Status | bci.Status1; |
1da177e4 LT |
565 | switch(status) { |
566 | case SECTOR_FREE: | |
567 | return writeEUN; | |
568 | ||
569 | case SECTOR_DELETED: | |
570 | case SECTOR_USED: | |
571 | case SECTOR_IGNORE: | |
572 | break; | |
573 | default: | |
574 | // Invalid block. Don't use it any more. Must implement. | |
97894cda | 575 | break; |
1da177e4 | 576 | } |
97894cda TG |
577 | |
578 | if (!silly--) { | |
1da177e4 LT |
579 | printk(KERN_WARNING |
580 | "Infinite loop in Virtual Unit Chain 0x%x\n", | |
581 | thisVUC); | |
582 | return 0xffff; | |
583 | } | |
584 | ||
585 | /* Skip to next block in chain */ | |
586 | writeEUN = nftl->ReplUnitTable[writeEUN]; | |
587 | } | |
588 | ||
97894cda | 589 | /* OK. We didn't find one in the existing chain, or there |
1da177e4 LT |
590 | is no existing chain. */ |
591 | ||
592 | /* Try to find an already-free block */ | |
593 | writeEUN = NFTL_findfreeblock(nftl, 0); | |
594 | ||
595 | if (writeEUN == BLOCK_NIL) { | |
596 | /* That didn't work - there were no free blocks just | |
597 | waiting to be picked up. We're going to have to fold | |
598 | a chain to make room. | |
599 | */ | |
600 | ||
601 | /* First remember the start of this chain */ | |
602 | //u16 startEUN = nftl->EUNtable[thisVUC]; | |
97894cda | 603 | |
1da177e4 LT |
604 | //printk("Write to VirtualUnitChain %d, calling makefreeblock()\n", thisVUC); |
605 | writeEUN = NFTL_makefreeblock(nftl, 0xffff); | |
606 | ||
607 | if (writeEUN == BLOCK_NIL) { | |
97894cda | 608 | /* OK, we accept that the above comment is |
1da177e4 LT |
609 | lying - there may have been free blocks |
610 | last time we called NFTL_findfreeblock(), | |
611 | but they are reserved for when we're | |
612 | desperate. Well, now we're desperate. | |
613 | */ | |
614 | DEBUG(MTD_DEBUG_LEVEL1, "Using desperate==1 to find free EUN to accommodate write to VUC %d\n", thisVUC); | |
615 | writeEUN = NFTL_findfreeblock(nftl, 1); | |
616 | } | |
617 | if (writeEUN == BLOCK_NIL) { | |
618 | /* Ouch. This should never happen - we should | |
97894cda TG |
619 | always be able to make some room somehow. |
620 | If we get here, we've allocated more storage | |
1da177e4 LT |
621 | space than actual media, or our makefreeblock |
622 | routine is missing something. | |
623 | */ | |
624 | printk(KERN_WARNING "Cannot make free space.\n"); | |
625 | return BLOCK_NIL; | |
97894cda | 626 | } |
1da177e4 LT |
627 | //printk("Restarting scan\n"); |
628 | lastEUN = BLOCK_NIL; | |
629 | continue; | |
630 | } | |
631 | ||
632 | /* We've found a free block. Insert it into the chain. */ | |
97894cda | 633 | |
1da177e4 | 634 | if (lastEUN != BLOCK_NIL) { |
f4a43cfc | 635 | thisVUC |= 0x8000; /* It's a replacement block */ |
1da177e4 | 636 | } else { |
f4a43cfc TG |
637 | /* The first block in a new chain */ |
638 | nftl->EUNtable[thisVUC] = writeEUN; | |
1da177e4 LT |
639 | } |
640 | ||
641 | /* set up the actual EUN we're writing into */ | |
642 | /* Both in our cache... */ | |
643 | nftl->ReplUnitTable[writeEUN] = BLOCK_NIL; | |
644 | ||
645 | /* ... and on the flash itself */ | |
8593fbc6 | 646 | nftl_read_oob(mtd, writeEUN * nftl->EraseSize + 8, 8, |
f4a43cfc | 647 | &retlen, (char *)&oob.u); |
1da177e4 LT |
648 | |
649 | oob.u.a.VirtUnitNum = oob.u.a.SpareVirtUnitNum = cpu_to_le16(thisVUC); | |
650 | ||
8593fbc6 | 651 | nftl_write_oob(mtd, writeEUN * nftl->EraseSize + 8, 8, |
f4a43cfc | 652 | &retlen, (char *)&oob.u); |
1da177e4 | 653 | |
f4a43cfc | 654 | /* we link the new block to the chain only after the |
1da177e4 LT |
655 | block is ready. It avoids the case where the chain |
656 | could point to a free block */ | |
f4a43cfc | 657 | if (lastEUN != BLOCK_NIL) { |
1da177e4 LT |
658 | /* Both in our cache... */ |
659 | nftl->ReplUnitTable[lastEUN] = writeEUN; | |
660 | /* ... and on the flash itself */ | |
8593fbc6 | 661 | nftl_read_oob(mtd, (lastEUN * nftl->EraseSize) + 8, |
f4a43cfc | 662 | 8, &retlen, (char *)&oob.u); |
1da177e4 LT |
663 | |
664 | oob.u.a.ReplUnitNum = oob.u.a.SpareReplUnitNum | |
665 | = cpu_to_le16(writeEUN); | |
666 | ||
8593fbc6 | 667 | nftl_write_oob(mtd, (lastEUN * nftl->EraseSize) + 8, |
f4a43cfc | 668 | 8, &retlen, (char *)&oob.u); |
1da177e4 LT |
669 | } |
670 | ||
671 | return writeEUN; | |
672 | ||
673 | } while (silly2--); | |
674 | ||
675 | printk(KERN_WARNING "Error folding to make room for Virtual Unit Chain 0x%x\n", | |
676 | thisVUC); | |
677 | return 0xffff; | |
678 | } | |
679 | ||
680 | static int nftl_writeblock(struct mtd_blktrans_dev *mbd, unsigned long block, | |
681 | char *buffer) | |
682 | { | |
683 | struct NFTLrecord *nftl = (void *)mbd; | |
684 | u16 writeEUN; | |
685 | unsigned long blockofs = (block * 512) & (nftl->EraseSize - 1); | |
686 | size_t retlen; | |
687 | struct nftl_oob oob; | |
688 | ||
689 | writeEUN = NFTL_findwriteunit(nftl, block); | |
690 | ||
691 | if (writeEUN == BLOCK_NIL) { | |
692 | printk(KERN_WARNING | |
693 | "NFTL_writeblock(): Cannot find block to write to\n"); | |
694 | /* If we _still_ haven't got a block to use, we're screwed */ | |
695 | return 1; | |
696 | } | |
697 | ||
698 | memset(&oob, 0xff, sizeof(struct nftl_oob)); | |
699 | oob.b.Status = oob.b.Status1 = SECTOR_USED; | |
1da177e4 | 700 | |
8593fbc6 TG |
701 | nftl_write(nftl->mbd.mtd, (writeEUN * nftl->EraseSize) + blockofs, |
702 | 512, &retlen, (char *)buffer, (char *)&oob); | |
1da177e4 LT |
703 | return 0; |
704 | } | |
705 | #endif /* CONFIG_NFTL_RW */ | |
706 | ||
707 | static int nftl_readblock(struct mtd_blktrans_dev *mbd, unsigned long block, | |
708 | char *buffer) | |
709 | { | |
710 | struct NFTLrecord *nftl = (void *)mbd; | |
f4a43cfc | 711 | struct mtd_info *mtd = nftl->mbd.mtd; |
1da177e4 LT |
712 | u16 lastgoodEUN; |
713 | u16 thisEUN = nftl->EUNtable[block / (nftl->EraseSize / 512)]; | |
714 | unsigned long blockofs = (block * 512) & (nftl->EraseSize - 1); | |
f4a43cfc | 715 | unsigned int status; |
1da177e4 | 716 | int silly = MAX_LOOPS; |
f4a43cfc TG |
717 | size_t retlen; |
718 | struct nftl_bci bci; | |
1da177e4 LT |
719 | |
720 | lastgoodEUN = BLOCK_NIL; | |
721 | ||
f4a43cfc | 722 | if (thisEUN != BLOCK_NIL) { |
1da177e4 | 723 | while (thisEUN < nftl->nb_blocks) { |
8593fbc6 | 724 | if (nftl_read_oob(mtd, (thisEUN * nftl->EraseSize) + |
f4a43cfc TG |
725 | blockofs, 8, &retlen, |
726 | (char *)&bci) < 0) | |
1da177e4 LT |
727 | status = SECTOR_IGNORE; |
728 | else | |
729 | status = bci.Status | bci.Status1; | |
730 | ||
731 | switch (status) { | |
732 | case SECTOR_FREE: | |
733 | /* no modification of a sector should follow a free sector */ | |
734 | goto the_end; | |
735 | case SECTOR_DELETED: | |
736 | lastgoodEUN = BLOCK_NIL; | |
737 | break; | |
738 | case SECTOR_USED: | |
739 | lastgoodEUN = thisEUN; | |
740 | break; | |
741 | case SECTOR_IGNORE: | |
742 | break; | |
743 | default: | |
744 | printk("Unknown status for block %ld in EUN %d: %x\n", | |
745 | block, thisEUN, status); | |
746 | break; | |
747 | } | |
748 | ||
749 | if (!silly--) { | |
750 | printk(KERN_WARNING "Infinite loop in Virtual Unit Chain 0x%lx\n", | |
751 | block / (nftl->EraseSize / 512)); | |
752 | return 1; | |
753 | } | |
754 | thisEUN = nftl->ReplUnitTable[thisEUN]; | |
755 | } | |
f4a43cfc | 756 | } |
1da177e4 LT |
757 | |
758 | the_end: | |
759 | if (lastgoodEUN == BLOCK_NIL) { | |
760 | /* the requested block is not on the media, return all 0x00 */ | |
761 | memset(buffer, 0, 512); | |
762 | } else { | |
763 | loff_t ptr = (lastgoodEUN * nftl->EraseSize) + blockofs; | |
764 | size_t retlen; | |
9a1fcdfd TG |
765 | int res = mtd->read(mtd, ptr, 512, &retlen, buffer); |
766 | ||
767 | if (res < 0 && res != -EUCLEAN) | |
1da177e4 LT |
768 | return -EIO; |
769 | } | |
770 | return 0; | |
771 | } | |
772 | ||
773 | static int nftl_getgeo(struct mtd_blktrans_dev *dev, struct hd_geometry *geo) | |
774 | { | |
775 | struct NFTLrecord *nftl = (void *)dev; | |
776 | ||
777 | geo->heads = nftl->heads; | |
778 | geo->sectors = nftl->sectors; | |
779 | geo->cylinders = nftl->cylinders; | |
780 | ||
781 | return 0; | |
782 | } | |
783 | ||
784 | /**************************************************************************** | |
785 | * | |
786 | * Module stuff | |
787 | * | |
788 | ****************************************************************************/ | |
789 | ||
790 | ||
791 | static struct mtd_blktrans_ops nftl_tr = { | |
792 | .name = "nftl", | |
793 | .major = NFTL_MAJOR, | |
794 | .part_bits = NFTL_PARTN_BITS, | |
19187672 | 795 | .blksize = 512, |
1da177e4 LT |
796 | .getgeo = nftl_getgeo, |
797 | .readsect = nftl_readblock, | |
798 | #ifdef CONFIG_NFTL_RW | |
799 | .writesect = nftl_writeblock, | |
800 | #endif | |
801 | .add_mtd = nftl_add_mtd, | |
802 | .remove_dev = nftl_remove_dev, | |
803 | .owner = THIS_MODULE, | |
804 | }; | |
805 | ||
806 | extern char nftlmountrev[]; | |
807 | ||
808 | static int __init init_nftl(void) | |
809 | { | |
97894cda | 810 | printk(KERN_INFO "NFTL driver: nftlcore.c $Revision: 1.98 $, nftlmount.c %s\n", nftlmountrev); |
1da177e4 LT |
811 | |
812 | return register_mtd_blktrans(&nftl_tr); | |
813 | } | |
814 | ||
815 | static void __exit cleanup_nftl(void) | |
816 | { | |
817 | deregister_mtd_blktrans(&nftl_tr); | |
818 | } | |
819 | ||
820 | module_init(init_nftl); | |
821 | module_exit(cleanup_nftl); | |
822 | ||
823 | MODULE_LICENSE("GPL"); | |
824 | MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>, Fabrice Bellard <fabrice.bellard@netgem.com> et al."); | |
825 | MODULE_DESCRIPTION("Support code for NAND Flash Translation Layer, used on M-Systems DiskOnChip 2000 and Millennium"); |