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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> | |
20 | #include <linux/pci.h> | |
21 | #include <linux/delay.h> | |
22 | #include <linux/slab.h> | |
23 | #include <linux/sched.h> | |
24 | #include <linux/init.h> | |
25 | #include <linux/hdreg.h> | |
26 | ||
27 | #include <linux/kmod.h> | |
28 | #include <linux/mtd/mtd.h> | |
29 | #include <linux/mtd/nand.h> | |
30 | #include <linux/mtd/nftl.h> | |
31 | #include <linux/mtd/blktrans.h> | |
32 | ||
33 | /* maximum number of loops while examining next block, to have a | |
34 | chance to detect consistency problems (they should never happen | |
35 | because of the checks done in the mounting */ | |
36 | ||
37 | #define MAX_LOOPS 10000 | |
38 | ||
39 | ||
40 | static void nftl_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd) | |
41 | { | |
42 | struct NFTLrecord *nftl; | |
43 | unsigned long temp; | |
44 | ||
45 | if (mtd->type != MTD_NANDFLASH) | |
46 | return; | |
47 | /* OK, this is moderately ugly. But probably safe. Alternatives? */ | |
48 | if (memcmp(mtd->name, "DiskOnChip", 10)) | |
49 | return; | |
50 | ||
51 | if (!mtd->block_isbad) { | |
52 | printk(KERN_ERR | |
53 | "NFTL no longer supports the old DiskOnChip drivers loaded via docprobe.\n" | |
54 | "Please use the new diskonchip driver under the NAND subsystem.\n"); | |
55 | return; | |
56 | } | |
57 | ||
58 | DEBUG(MTD_DEBUG_LEVEL1, "NFTL: add_mtd for %s\n", mtd->name); | |
59 | ||
60 | nftl = kmalloc(sizeof(struct NFTLrecord), GFP_KERNEL); | |
61 | ||
62 | if (!nftl) { | |
63 | printk(KERN_WARNING "NFTL: out of memory for data structures\n"); | |
64 | return; | |
65 | } | |
66 | memset(nftl, 0, sizeof(*nftl)); | |
67 | ||
68 | nftl->mbd.mtd = mtd; | |
69 | nftl->mbd.devnum = -1; | |
19187672 | 70 | |
1da177e4 | 71 | nftl->mbd.tr = tr; |
1da177e4 LT |
72 | |
73 | if (NFTL_mount(nftl) < 0) { | |
74 | printk(KERN_WARNING "NFTL: could not mount device\n"); | |
75 | kfree(nftl); | |
76 | return; | |
77 | } | |
78 | ||
79 | /* OK, it's a new one. Set up all the data structures. */ | |
80 | ||
81 | /* Calculate geometry */ | |
82 | nftl->cylinders = 1024; | |
83 | nftl->heads = 16; | |
84 | ||
85 | temp = nftl->cylinders * nftl->heads; | |
86 | nftl->sectors = nftl->mbd.size / temp; | |
87 | if (nftl->mbd.size % temp) { | |
88 | nftl->sectors++; | |
89 | temp = nftl->cylinders * nftl->sectors; | |
90 | nftl->heads = nftl->mbd.size / temp; | |
91 | ||
92 | if (nftl->mbd.size % temp) { | |
93 | nftl->heads++; | |
94 | temp = nftl->heads * nftl->sectors; | |
95 | nftl->cylinders = nftl->mbd.size / temp; | |
96 | } | |
97 | } | |
98 | ||
99 | if (nftl->mbd.size != nftl->heads * nftl->cylinders * nftl->sectors) { | |
100 | /* | |
97894cda | 101 | Oh no we don't have |
1da177e4 LT |
102 | mbd.size == heads * cylinders * sectors |
103 | */ | |
104 | printk(KERN_WARNING "NFTL: cannot calculate a geometry to " | |
105 | "match size of 0x%lx.\n", nftl->mbd.size); | |
106 | printk(KERN_WARNING "NFTL: using C:%d H:%d S:%d " | |
107 | "(== 0x%lx sects)\n", | |
97894cda | 108 | nftl->cylinders, nftl->heads , nftl->sectors, |
1da177e4 LT |
109 | (long)nftl->cylinders * (long)nftl->heads * |
110 | (long)nftl->sectors ); | |
111 | } | |
112 | ||
113 | if (add_mtd_blktrans_dev(&nftl->mbd)) { | |
fa671646 JJ |
114 | kfree(nftl->ReplUnitTable); |
115 | kfree(nftl->EUNtable); | |
1da177e4 LT |
116 | kfree(nftl); |
117 | return; | |
118 | } | |
119 | #ifdef PSYCHO_DEBUG | |
120 | printk(KERN_INFO "NFTL: Found new nftl%c\n", nftl->mbd.devnum + 'a'); | |
121 | #endif | |
122 | } | |
123 | ||
124 | static void nftl_remove_dev(struct mtd_blktrans_dev *dev) | |
125 | { | |
126 | struct NFTLrecord *nftl = (void *)dev; | |
127 | ||
128 | DEBUG(MTD_DEBUG_LEVEL1, "NFTL: remove_dev (i=%d)\n", dev->devnum); | |
129 | ||
130 | del_mtd_blktrans_dev(dev); | |
fa671646 JJ |
131 | kfree(nftl->ReplUnitTable); |
132 | kfree(nftl->EUNtable); | |
1da177e4 LT |
133 | kfree(nftl); |
134 | } | |
135 | ||
8593fbc6 TG |
136 | /* |
137 | * Read oob data from flash | |
138 | */ | |
139 | int nftl_read_oob(struct mtd_info *mtd, loff_t offs, size_t len, | |
140 | size_t *retlen, uint8_t *buf) | |
141 | { | |
142 | struct mtd_oob_ops ops; | |
143 | int res; | |
144 | ||
145 | ops.mode = MTD_OOB_PLACE; | |
146 | ops.ooboffs = offs & (mtd->writesize - 1); | |
147 | ops.ooblen = len; | |
148 | ops.oobbuf = buf; | |
149 | ops.datbuf = NULL; | |
150 | ops.len = len; | |
151 | ||
152 | res = mtd->read_oob(mtd, offs & ~(mtd->writesize - 1), &ops); | |
153 | *retlen = ops.retlen; | |
154 | return res; | |
155 | } | |
156 | ||
157 | /* | |
158 | * Write oob data to flash | |
159 | */ | |
160 | int nftl_write_oob(struct mtd_info *mtd, loff_t offs, size_t len, | |
161 | size_t *retlen, uint8_t *buf) | |
162 | { | |
163 | struct mtd_oob_ops ops; | |
164 | int res; | |
165 | ||
166 | ops.mode = MTD_OOB_PLACE; | |
167 | ops.ooboffs = offs & (mtd->writesize - 1); | |
168 | ops.ooblen = len; | |
169 | ops.oobbuf = buf; | |
170 | ops.datbuf = NULL; | |
171 | ops.len = len; | |
172 | ||
173 | res = mtd->write_oob(mtd, offs & ~(mtd->writesize - 1), &ops); | |
174 | *retlen = ops.retlen; | |
175 | return res; | |
176 | } | |
177 | ||
553a8012 FD |
178 | #ifdef CONFIG_NFTL_RW |
179 | ||
8593fbc6 TG |
180 | /* |
181 | * Write data and oob to flash | |
182 | */ | |
183 | static int nftl_write(struct mtd_info *mtd, loff_t offs, size_t len, | |
184 | size_t *retlen, uint8_t *buf, uint8_t *oob) | |
185 | { | |
186 | struct mtd_oob_ops ops; | |
187 | int res; | |
188 | ||
189 | ops.mode = MTD_OOB_PLACE; | |
190 | ops.ooboffs = offs; | |
191 | ops.ooblen = mtd->oobsize; | |
192 | ops.oobbuf = oob; | |
193 | ops.datbuf = buf; | |
194 | ops.len = len; | |
195 | ||
196 | res = mtd->write_oob(mtd, offs & ~(mtd->writesize - 1), &ops); | |
197 | *retlen = ops.retlen; | |
198 | return res; | |
199 | } | |
200 | ||
1da177e4 LT |
201 | /* Actual NFTL access routines */ |
202 | /* NFTL_findfreeblock: Find a free Erase Unit on the NFTL partition. This function is used | |
203 | * when the give Virtual Unit Chain | |
204 | */ | |
205 | static u16 NFTL_findfreeblock(struct NFTLrecord *nftl, int desperate ) | |
206 | { | |
207 | /* For a given Virtual Unit Chain: find or create a free block and | |
208 | add it to the chain */ | |
209 | /* We're passed the number of the last EUN in the chain, to save us from | |
210 | having to look it up again */ | |
211 | u16 pot = nftl->LastFreeEUN; | |
212 | int silly = nftl->nb_blocks; | |
213 | ||
214 | /* Normally, we force a fold to happen before we run out of free blocks completely */ | |
215 | if (!desperate && nftl->numfreeEUNs < 2) { | |
216 | DEBUG(MTD_DEBUG_LEVEL1, "NFTL_findfreeblock: there are too few free EUNs\n"); | |
217 | return 0xffff; | |
218 | } | |
219 | ||
220 | /* Scan for a free block */ | |
221 | do { | |
222 | if (nftl->ReplUnitTable[pot] == BLOCK_FREE) { | |
223 | nftl->LastFreeEUN = pot; | |
224 | nftl->numfreeEUNs--; | |
225 | return pot; | |
226 | } | |
227 | ||
228 | /* This will probably point to the MediaHdr unit itself, | |
229 | right at the beginning of the partition. But that unit | |
230 | (and the backup unit too) should have the UCI set | |
231 | up so that it's not selected for overwriting */ | |
232 | if (++pot > nftl->lastEUN) | |
233 | pot = le16_to_cpu(nftl->MediaHdr.FirstPhysicalEUN); | |
234 | ||
235 | if (!silly--) { | |
236 | printk("Argh! No free blocks found! LastFreeEUN = %d, " | |
97894cda | 237 | "FirstEUN = %d\n", nftl->LastFreeEUN, |
1da177e4 LT |
238 | le16_to_cpu(nftl->MediaHdr.FirstPhysicalEUN)); |
239 | return 0xffff; | |
240 | } | |
241 | } while (pot != nftl->LastFreeEUN); | |
242 | ||
243 | return 0xffff; | |
244 | } | |
245 | ||
246 | static u16 NFTL_foldchain (struct NFTLrecord *nftl, unsigned thisVUC, unsigned pendingblock ) | |
247 | { | |
f4a43cfc | 248 | struct mtd_info *mtd = nftl->mbd.mtd; |
1da177e4 LT |
249 | u16 BlockMap[MAX_SECTORS_PER_UNIT]; |
250 | unsigned char BlockLastState[MAX_SECTORS_PER_UNIT]; | |
251 | unsigned char BlockFreeFound[MAX_SECTORS_PER_UNIT]; | |
252 | unsigned int thisEUN; | |
253 | int block; | |
254 | int silly; | |
255 | unsigned int targetEUN; | |
256 | struct nftl_oob oob; | |
257 | int inplace = 1; | |
f4a43cfc | 258 | size_t retlen; |
1da177e4 LT |
259 | |
260 | memset(BlockMap, 0xff, sizeof(BlockMap)); | |
261 | memset(BlockFreeFound, 0, sizeof(BlockFreeFound)); | |
262 | ||
263 | thisEUN = nftl->EUNtable[thisVUC]; | |
264 | ||
265 | if (thisEUN == BLOCK_NIL) { | |
266 | printk(KERN_WARNING "Trying to fold non-existent " | |
267 | "Virtual Unit Chain %d!\n", thisVUC); | |
268 | return BLOCK_NIL; | |
269 | } | |
97894cda | 270 | |
1da177e4 LT |
271 | /* Scan to find the Erase Unit which holds the actual data for each |
272 | 512-byte block within the Chain. | |
273 | */ | |
f4a43cfc | 274 | silly = MAX_LOOPS; |
1da177e4 LT |
275 | targetEUN = BLOCK_NIL; |
276 | while (thisEUN <= nftl->lastEUN ) { | |
f4a43cfc | 277 | unsigned int status, foldmark; |
1da177e4 LT |
278 | |
279 | targetEUN = thisEUN; | |
280 | for (block = 0; block < nftl->EraseSize / 512; block ++) { | |
8593fbc6 | 281 | nftl_read_oob(mtd, (thisEUN * nftl->EraseSize) + |
f4a43cfc TG |
282 | (block * 512), 16 , &retlen, |
283 | (char *)&oob); | |
1da177e4 | 284 | if (block == 2) { |
f4a43cfc TG |
285 | foldmark = oob.u.c.FoldMark | oob.u.c.FoldMark1; |
286 | if (foldmark == FOLD_MARK_IN_PROGRESS) { | |
287 | DEBUG(MTD_DEBUG_LEVEL1, | |
288 | "Write Inhibited on EUN %d\n", thisEUN); | |
1da177e4 LT |
289 | inplace = 0; |
290 | } else { | |
291 | /* There's no other reason not to do inplace, | |
292 | except ones that come later. So we don't need | |
293 | to preserve inplace */ | |
294 | inplace = 1; | |
295 | } | |
296 | } | |
f4a43cfc | 297 | status = oob.b.Status | oob.b.Status1; |
1da177e4 LT |
298 | BlockLastState[block] = status; |
299 | ||
300 | switch(status) { | |
301 | case SECTOR_FREE: | |
302 | BlockFreeFound[block] = 1; | |
303 | break; | |
304 | ||
305 | case SECTOR_USED: | |
306 | if (!BlockFreeFound[block]) | |
307 | BlockMap[block] = thisEUN; | |
308 | else | |
97894cda | 309 | printk(KERN_WARNING |
1da177e4 LT |
310 | "SECTOR_USED found after SECTOR_FREE " |
311 | "in Virtual Unit Chain %d for block %d\n", | |
312 | thisVUC, block); | |
313 | break; | |
314 | case SECTOR_DELETED: | |
315 | if (!BlockFreeFound[block]) | |
316 | BlockMap[block] = BLOCK_NIL; | |
317 | else | |
97894cda | 318 | printk(KERN_WARNING |
1da177e4 LT |
319 | "SECTOR_DELETED found after SECTOR_FREE " |
320 | "in Virtual Unit Chain %d for block %d\n", | |
321 | thisVUC, block); | |
322 | break; | |
323 | ||
324 | case SECTOR_IGNORE: | |
325 | break; | |
326 | default: | |
327 | printk("Unknown status for block %d in EUN %d: %x\n", | |
328 | block, thisEUN, status); | |
329 | } | |
330 | } | |
331 | ||
332 | if (!silly--) { | |
333 | printk(KERN_WARNING "Infinite loop in Virtual Unit Chain 0x%x\n", | |
334 | thisVUC); | |
335 | return BLOCK_NIL; | |
336 | } | |
97894cda | 337 | |
1da177e4 LT |
338 | thisEUN = nftl->ReplUnitTable[thisEUN]; |
339 | } | |
340 | ||
341 | if (inplace) { | |
342 | /* We're being asked to be a fold-in-place. Check | |
343 | that all blocks which actually have data associated | |
97894cda | 344 | with them (i.e. BlockMap[block] != BLOCK_NIL) are |
1da177e4 LT |
345 | either already present or SECTOR_FREE in the target |
346 | block. If not, we're going to have to fold out-of-place | |
347 | anyway. | |
348 | */ | |
349 | for (block = 0; block < nftl->EraseSize / 512 ; block++) { | |
350 | if (BlockLastState[block] != SECTOR_FREE && | |
351 | BlockMap[block] != BLOCK_NIL && | |
352 | BlockMap[block] != targetEUN) { | |
353 | DEBUG(MTD_DEBUG_LEVEL1, "Setting inplace to 0. VUC %d, " | |
354 | "block %d was %x lastEUN, " | |
355 | "and is in EUN %d (%s) %d\n", | |
356 | thisVUC, block, BlockLastState[block], | |
97894cda | 357 | BlockMap[block], |
1da177e4 LT |
358 | BlockMap[block]== targetEUN ? "==" : "!=", |
359 | targetEUN); | |
360 | inplace = 0; | |
361 | break; | |
362 | } | |
363 | } | |
364 | ||
365 | if (pendingblock >= (thisVUC * (nftl->EraseSize / 512)) && | |
366 | pendingblock < ((thisVUC + 1)* (nftl->EraseSize / 512)) && | |
367 | BlockLastState[pendingblock - (thisVUC * (nftl->EraseSize / 512))] != | |
368 | SECTOR_FREE) { | |
369 | DEBUG(MTD_DEBUG_LEVEL1, "Pending write not free in EUN %d. " | |
370 | "Folding out of place.\n", targetEUN); | |
371 | inplace = 0; | |
372 | } | |
373 | } | |
97894cda | 374 | |
1da177e4 LT |
375 | if (!inplace) { |
376 | DEBUG(MTD_DEBUG_LEVEL1, "Cannot fold Virtual Unit Chain %d in place. " | |
377 | "Trying out-of-place\n", thisVUC); | |
378 | /* We need to find a targetEUN to fold into. */ | |
379 | targetEUN = NFTL_findfreeblock(nftl, 1); | |
380 | if (targetEUN == BLOCK_NIL) { | |
97894cda | 381 | /* Ouch. Now we're screwed. We need to do a |
1da177e4 LT |
382 | fold-in-place of another chain to make room |
383 | for this one. We need a better way of selecting | |
97894cda | 384 | which chain to fold, because makefreeblock will |
1da177e4 LT |
385 | only ask us to fold the same one again. |
386 | */ | |
387 | printk(KERN_WARNING | |
388 | "NFTL_findfreeblock(desperate) returns 0xffff.\n"); | |
389 | return BLOCK_NIL; | |
390 | } | |
391 | } else { | |
f4a43cfc TG |
392 | /* We put a fold mark in the chain we are folding only if we |
393 | fold in place to help the mount check code. If we do not fold in | |
394 | place, it is possible to find the valid chain by selecting the | |
395 | longer one */ | |
396 | oob.u.c.FoldMark = oob.u.c.FoldMark1 = cpu_to_le16(FOLD_MARK_IN_PROGRESS); | |
397 | oob.u.c.unused = 0xffffffff; | |
8593fbc6 | 398 | nftl_write_oob(mtd, (nftl->EraseSize * targetEUN) + 2 * 512 + 8, |
f4a43cfc TG |
399 | 8, &retlen, (char *)&oob.u); |
400 | } | |
1da177e4 LT |
401 | |
402 | /* OK. We now know the location of every block in the Virtual Unit Chain, | |
403 | and the Erase Unit into which we are supposed to be copying. | |
404 | Go for it. | |
405 | */ | |
406 | DEBUG(MTD_DEBUG_LEVEL1,"Folding chain %d into unit %d\n", thisVUC, targetEUN); | |
407 | for (block = 0; block < nftl->EraseSize / 512 ; block++) { | |
408 | unsigned char movebuf[512]; | |
409 | int ret; | |
410 | ||
411 | /* If it's in the target EUN already, or if it's pending write, do nothing */ | |
412 | if (BlockMap[block] == targetEUN || | |
413 | (pendingblock == (thisVUC * (nftl->EraseSize / 512) + block))) { | |
414 | continue; | |
415 | } | |
416 | ||
f4a43cfc | 417 | /* copy only in non free block (free blocks can only |
1da177e4 | 418 | happen in case of media errors or deleted blocks) */ |
f4a43cfc TG |
419 | if (BlockMap[block] == BLOCK_NIL) |
420 | continue; | |
421 | ||
422 | ret = mtd->read(mtd, (nftl->EraseSize * BlockMap[block]) + (block * 512), | |
423 | 512, &retlen, movebuf); | |
9a1fcdfd | 424 | if (ret < 0 && ret != -EUCLEAN) { |
f4a43cfc TG |
425 | ret = mtd->read(mtd, (nftl->EraseSize * BlockMap[block]) |
426 | + (block * 512), 512, &retlen, | |
427 | movebuf); | |
428 | if (ret != -EIO) | |
429 | printk("Error went away on retry.\n"); | |
430 | } | |
1da177e4 LT |
431 | memset(&oob, 0xff, sizeof(struct nftl_oob)); |
432 | oob.b.Status = oob.b.Status1 = SECTOR_USED; | |
9223a456 | 433 | |
8593fbc6 TG |
434 | nftl_write(nftl->mbd.mtd, (nftl->EraseSize * targetEUN) + |
435 | (block * 512), 512, &retlen, movebuf, (char *)&oob); | |
1da177e4 | 436 | } |
97894cda | 437 | |
f4a43cfc TG |
438 | /* add the header so that it is now a valid chain */ |
439 | oob.u.a.VirtUnitNum = oob.u.a.SpareVirtUnitNum = cpu_to_le16(thisVUC); | |
440 | oob.u.a.ReplUnitNum = oob.u.a.SpareReplUnitNum = 0xffff; | |
97894cda | 441 | |
8593fbc6 | 442 | nftl_write_oob(mtd, (nftl->EraseSize * targetEUN) + 8, |
f4a43cfc | 443 | 8, &retlen, (char *)&oob.u); |
1da177e4 LT |
444 | |
445 | /* OK. We've moved the whole lot into the new block. Now we have to free the original blocks. */ | |
446 | ||
97894cda | 447 | /* At this point, we have two different chains for this Virtual Unit, and no way to tell |
1da177e4 LT |
448 | them apart. If we crash now, we get confused. However, both contain the same data, so we |
449 | shouldn't actually lose data in this case. It's just that when we load up on a medium which | |
450 | has duplicate chains, we need to free one of the chains because it's not necessary any more. | |
451 | */ | |
452 | thisEUN = nftl->EUNtable[thisVUC]; | |
453 | DEBUG(MTD_DEBUG_LEVEL1,"Want to erase\n"); | |
454 | ||
97894cda | 455 | /* For each block in the old chain (except the targetEUN of course), |
1da177e4 LT |
456 | free it and make it available for future use */ |
457 | while (thisEUN <= nftl->lastEUN && thisEUN != targetEUN) { | |
458 | unsigned int EUNtmp; | |
459 | ||
f4a43cfc | 460 | EUNtmp = nftl->ReplUnitTable[thisEUN]; |
1da177e4 | 461 | |
f4a43cfc | 462 | if (NFTL_formatblock(nftl, thisEUN) < 0) { |
1da177e4 LT |
463 | /* could not erase : mark block as reserved |
464 | */ | |
465 | nftl->ReplUnitTable[thisEUN] = BLOCK_RESERVED; | |
f4a43cfc | 466 | } else { |
1da177e4 LT |
467 | /* correctly erased : mark it as free */ |
468 | nftl->ReplUnitTable[thisEUN] = BLOCK_FREE; | |
469 | nftl->numfreeEUNs++; | |
f4a43cfc TG |
470 | } |
471 | thisEUN = EUNtmp; | |
1da177e4 | 472 | } |
97894cda | 473 | |
1da177e4 LT |
474 | /* Make this the new start of chain for thisVUC */ |
475 | nftl->ReplUnitTable[targetEUN] = BLOCK_NIL; | |
476 | nftl->EUNtable[thisVUC] = targetEUN; | |
477 | ||
478 | return targetEUN; | |
479 | } | |
480 | ||
481 | static u16 NFTL_makefreeblock( struct NFTLrecord *nftl , unsigned pendingblock) | |
482 | { | |
97894cda | 483 | /* This is the part that needs some cleverness applied. |
1da177e4 LT |
484 | For now, I'm doing the minimum applicable to actually |
485 | get the thing to work. | |
486 | Wear-levelling and other clever stuff needs to be implemented | |
487 | and we also need to do some assessment of the results when | |
488 | the system loses power half-way through the routine. | |
489 | */ | |
490 | u16 LongestChain = 0; | |
491 | u16 ChainLength = 0, thislen; | |
492 | u16 chain, EUN; | |
493 | ||
494 | for (chain = 0; chain < le32_to_cpu(nftl->MediaHdr.FormattedSize) / nftl->EraseSize; chain++) { | |
495 | EUN = nftl->EUNtable[chain]; | |
496 | thislen = 0; | |
497 | ||
498 | while (EUN <= nftl->lastEUN) { | |
499 | thislen++; | |
500 | //printk("VUC %d reaches len %d with EUN %d\n", chain, thislen, EUN); | |
501 | EUN = nftl->ReplUnitTable[EUN] & 0x7fff; | |
502 | if (thislen > 0xff00) { | |
503 | printk("Endless loop in Virtual Chain %d: Unit %x\n", | |
504 | chain, EUN); | |
505 | } | |
506 | if (thislen > 0xff10) { | |
507 | /* Actually, don't return failure. Just ignore this chain and | |
508 | get on with it. */ | |
509 | thislen = 0; | |
510 | break; | |
511 | } | |
512 | } | |
513 | ||
514 | if (thislen > ChainLength) { | |
515 | //printk("New longest chain is %d with length %d\n", chain, thislen); | |
516 | ChainLength = thislen; | |
517 | LongestChain = chain; | |
518 | } | |
519 | } | |
520 | ||
521 | if (ChainLength < 2) { | |
522 | printk(KERN_WARNING "No Virtual Unit Chains available for folding. " | |
523 | "Failing request\n"); | |
524 | return 0xffff; | |
525 | } | |
526 | ||
527 | return NFTL_foldchain (nftl, LongestChain, pendingblock); | |
528 | } | |
529 | ||
97894cda | 530 | /* NFTL_findwriteunit: Return the unit number into which we can write |
1da177e4 LT |
531 | for this block. Make it available if it isn't already |
532 | */ | |
533 | static inline u16 NFTL_findwriteunit(struct NFTLrecord *nftl, unsigned block) | |
534 | { | |
535 | u16 lastEUN; | |
536 | u16 thisVUC = block / (nftl->EraseSize / 512); | |
f4a43cfc | 537 | struct mtd_info *mtd = nftl->mbd.mtd; |
1da177e4 LT |
538 | unsigned int writeEUN; |
539 | unsigned long blockofs = (block * 512) & (nftl->EraseSize -1); | |
540 | size_t retlen; | |
541 | int silly, silly2 = 3; | |
542 | struct nftl_oob oob; | |
543 | ||
544 | do { | |
545 | /* Scan the media to find a unit in the VUC which has | |
546 | a free space for the block in question. | |
547 | */ | |
548 | ||
97894cda | 549 | /* This condition catches the 0x[7f]fff cases, as well as |
1da177e4 LT |
550 | being a sanity check for past-end-of-media access |
551 | */ | |
552 | lastEUN = BLOCK_NIL; | |
553 | writeEUN = nftl->EUNtable[thisVUC]; | |
f4a43cfc | 554 | silly = MAX_LOOPS; |
1da177e4 LT |
555 | while (writeEUN <= nftl->lastEUN) { |
556 | struct nftl_bci bci; | |
557 | size_t retlen; | |
f4a43cfc | 558 | unsigned int status; |
1da177e4 LT |
559 | |
560 | lastEUN = writeEUN; | |
561 | ||
8593fbc6 | 562 | nftl_read_oob(mtd, |
f4a43cfc TG |
563 | (writeEUN * nftl->EraseSize) + blockofs, |
564 | 8, &retlen, (char *)&bci); | |
97894cda | 565 | |
1da177e4 LT |
566 | DEBUG(MTD_DEBUG_LEVEL2, "Status of block %d in EUN %d is %x\n", |
567 | block , writeEUN, le16_to_cpu(bci.Status)); | |
568 | ||
f4a43cfc | 569 | status = bci.Status | bci.Status1; |
1da177e4 LT |
570 | switch(status) { |
571 | case SECTOR_FREE: | |
572 | return writeEUN; | |
573 | ||
574 | case SECTOR_DELETED: | |
575 | case SECTOR_USED: | |
576 | case SECTOR_IGNORE: | |
577 | break; | |
578 | default: | |
579 | // Invalid block. Don't use it any more. Must implement. | |
97894cda | 580 | break; |
1da177e4 | 581 | } |
97894cda TG |
582 | |
583 | if (!silly--) { | |
1da177e4 LT |
584 | printk(KERN_WARNING |
585 | "Infinite loop in Virtual Unit Chain 0x%x\n", | |
586 | thisVUC); | |
587 | return 0xffff; | |
588 | } | |
589 | ||
590 | /* Skip to next block in chain */ | |
591 | writeEUN = nftl->ReplUnitTable[writeEUN]; | |
592 | } | |
593 | ||
97894cda | 594 | /* OK. We didn't find one in the existing chain, or there |
1da177e4 LT |
595 | is no existing chain. */ |
596 | ||
597 | /* Try to find an already-free block */ | |
598 | writeEUN = NFTL_findfreeblock(nftl, 0); | |
599 | ||
600 | if (writeEUN == BLOCK_NIL) { | |
601 | /* That didn't work - there were no free blocks just | |
602 | waiting to be picked up. We're going to have to fold | |
603 | a chain to make room. | |
604 | */ | |
605 | ||
606 | /* First remember the start of this chain */ | |
607 | //u16 startEUN = nftl->EUNtable[thisVUC]; | |
97894cda | 608 | |
1da177e4 LT |
609 | //printk("Write to VirtualUnitChain %d, calling makefreeblock()\n", thisVUC); |
610 | writeEUN = NFTL_makefreeblock(nftl, 0xffff); | |
611 | ||
612 | if (writeEUN == BLOCK_NIL) { | |
97894cda | 613 | /* OK, we accept that the above comment is |
1da177e4 LT |
614 | lying - there may have been free blocks |
615 | last time we called NFTL_findfreeblock(), | |
616 | but they are reserved for when we're | |
617 | desperate. Well, now we're desperate. | |
618 | */ | |
619 | DEBUG(MTD_DEBUG_LEVEL1, "Using desperate==1 to find free EUN to accommodate write to VUC %d\n", thisVUC); | |
620 | writeEUN = NFTL_findfreeblock(nftl, 1); | |
621 | } | |
622 | if (writeEUN == BLOCK_NIL) { | |
623 | /* Ouch. This should never happen - we should | |
97894cda TG |
624 | always be able to make some room somehow. |
625 | If we get here, we've allocated more storage | |
1da177e4 LT |
626 | space than actual media, or our makefreeblock |
627 | routine is missing something. | |
628 | */ | |
629 | printk(KERN_WARNING "Cannot make free space.\n"); | |
630 | return BLOCK_NIL; | |
97894cda | 631 | } |
1da177e4 LT |
632 | //printk("Restarting scan\n"); |
633 | lastEUN = BLOCK_NIL; | |
634 | continue; | |
635 | } | |
636 | ||
637 | /* We've found a free block. Insert it into the chain. */ | |
97894cda | 638 | |
1da177e4 | 639 | if (lastEUN != BLOCK_NIL) { |
f4a43cfc | 640 | thisVUC |= 0x8000; /* It's a replacement block */ |
1da177e4 | 641 | } else { |
f4a43cfc TG |
642 | /* The first block in a new chain */ |
643 | nftl->EUNtable[thisVUC] = writeEUN; | |
1da177e4 LT |
644 | } |
645 | ||
646 | /* set up the actual EUN we're writing into */ | |
647 | /* Both in our cache... */ | |
648 | nftl->ReplUnitTable[writeEUN] = BLOCK_NIL; | |
649 | ||
650 | /* ... and on the flash itself */ | |
8593fbc6 | 651 | nftl_read_oob(mtd, writeEUN * nftl->EraseSize + 8, 8, |
f4a43cfc | 652 | &retlen, (char *)&oob.u); |
1da177e4 LT |
653 | |
654 | oob.u.a.VirtUnitNum = oob.u.a.SpareVirtUnitNum = cpu_to_le16(thisVUC); | |
655 | ||
8593fbc6 | 656 | nftl_write_oob(mtd, writeEUN * nftl->EraseSize + 8, 8, |
f4a43cfc | 657 | &retlen, (char *)&oob.u); |
1da177e4 | 658 | |
f4a43cfc | 659 | /* we link the new block to the chain only after the |
1da177e4 LT |
660 | block is ready. It avoids the case where the chain |
661 | could point to a free block */ | |
f4a43cfc | 662 | if (lastEUN != BLOCK_NIL) { |
1da177e4 LT |
663 | /* Both in our cache... */ |
664 | nftl->ReplUnitTable[lastEUN] = writeEUN; | |
665 | /* ... and on the flash itself */ | |
8593fbc6 | 666 | nftl_read_oob(mtd, (lastEUN * nftl->EraseSize) + 8, |
f4a43cfc | 667 | 8, &retlen, (char *)&oob.u); |
1da177e4 LT |
668 | |
669 | oob.u.a.ReplUnitNum = oob.u.a.SpareReplUnitNum | |
670 | = cpu_to_le16(writeEUN); | |
671 | ||
8593fbc6 | 672 | nftl_write_oob(mtd, (lastEUN * nftl->EraseSize) + 8, |
f4a43cfc | 673 | 8, &retlen, (char *)&oob.u); |
1da177e4 LT |
674 | } |
675 | ||
676 | return writeEUN; | |
677 | ||
678 | } while (silly2--); | |
679 | ||
680 | printk(KERN_WARNING "Error folding to make room for Virtual Unit Chain 0x%x\n", | |
681 | thisVUC); | |
682 | return 0xffff; | |
683 | } | |
684 | ||
685 | static int nftl_writeblock(struct mtd_blktrans_dev *mbd, unsigned long block, | |
686 | char *buffer) | |
687 | { | |
688 | struct NFTLrecord *nftl = (void *)mbd; | |
689 | u16 writeEUN; | |
690 | unsigned long blockofs = (block * 512) & (nftl->EraseSize - 1); | |
691 | size_t retlen; | |
692 | struct nftl_oob oob; | |
693 | ||
694 | writeEUN = NFTL_findwriteunit(nftl, block); | |
695 | ||
696 | if (writeEUN == BLOCK_NIL) { | |
697 | printk(KERN_WARNING | |
698 | "NFTL_writeblock(): Cannot find block to write to\n"); | |
699 | /* If we _still_ haven't got a block to use, we're screwed */ | |
700 | return 1; | |
701 | } | |
702 | ||
703 | memset(&oob, 0xff, sizeof(struct nftl_oob)); | |
704 | oob.b.Status = oob.b.Status1 = SECTOR_USED; | |
1da177e4 | 705 | |
8593fbc6 TG |
706 | nftl_write(nftl->mbd.mtd, (writeEUN * nftl->EraseSize) + blockofs, |
707 | 512, &retlen, (char *)buffer, (char *)&oob); | |
1da177e4 LT |
708 | return 0; |
709 | } | |
710 | #endif /* CONFIG_NFTL_RW */ | |
711 | ||
712 | static int nftl_readblock(struct mtd_blktrans_dev *mbd, unsigned long block, | |
713 | char *buffer) | |
714 | { | |
715 | struct NFTLrecord *nftl = (void *)mbd; | |
f4a43cfc | 716 | struct mtd_info *mtd = nftl->mbd.mtd; |
1da177e4 LT |
717 | u16 lastgoodEUN; |
718 | u16 thisEUN = nftl->EUNtable[block / (nftl->EraseSize / 512)]; | |
719 | unsigned long blockofs = (block * 512) & (nftl->EraseSize - 1); | |
f4a43cfc | 720 | unsigned int status; |
1da177e4 | 721 | int silly = MAX_LOOPS; |
f4a43cfc TG |
722 | size_t retlen; |
723 | struct nftl_bci bci; | |
1da177e4 LT |
724 | |
725 | lastgoodEUN = BLOCK_NIL; | |
726 | ||
f4a43cfc | 727 | if (thisEUN != BLOCK_NIL) { |
1da177e4 | 728 | while (thisEUN < nftl->nb_blocks) { |
8593fbc6 | 729 | if (nftl_read_oob(mtd, (thisEUN * nftl->EraseSize) + |
f4a43cfc TG |
730 | blockofs, 8, &retlen, |
731 | (char *)&bci) < 0) | |
1da177e4 LT |
732 | status = SECTOR_IGNORE; |
733 | else | |
734 | status = bci.Status | bci.Status1; | |
735 | ||
736 | switch (status) { | |
737 | case SECTOR_FREE: | |
738 | /* no modification of a sector should follow a free sector */ | |
739 | goto the_end; | |
740 | case SECTOR_DELETED: | |
741 | lastgoodEUN = BLOCK_NIL; | |
742 | break; | |
743 | case SECTOR_USED: | |
744 | lastgoodEUN = thisEUN; | |
745 | break; | |
746 | case SECTOR_IGNORE: | |
747 | break; | |
748 | default: | |
749 | printk("Unknown status for block %ld in EUN %d: %x\n", | |
750 | block, thisEUN, status); | |
751 | break; | |
752 | } | |
753 | ||
754 | if (!silly--) { | |
755 | printk(KERN_WARNING "Infinite loop in Virtual Unit Chain 0x%lx\n", | |
756 | block / (nftl->EraseSize / 512)); | |
757 | return 1; | |
758 | } | |
759 | thisEUN = nftl->ReplUnitTable[thisEUN]; | |
760 | } | |
f4a43cfc | 761 | } |
1da177e4 LT |
762 | |
763 | the_end: | |
764 | if (lastgoodEUN == BLOCK_NIL) { | |
765 | /* the requested block is not on the media, return all 0x00 */ | |
766 | memset(buffer, 0, 512); | |
767 | } else { | |
768 | loff_t ptr = (lastgoodEUN * nftl->EraseSize) + blockofs; | |
769 | size_t retlen; | |
9a1fcdfd TG |
770 | int res = mtd->read(mtd, ptr, 512, &retlen, buffer); |
771 | ||
772 | if (res < 0 && res != -EUCLEAN) | |
1da177e4 LT |
773 | return -EIO; |
774 | } | |
775 | return 0; | |
776 | } | |
777 | ||
778 | static int nftl_getgeo(struct mtd_blktrans_dev *dev, struct hd_geometry *geo) | |
779 | { | |
780 | struct NFTLrecord *nftl = (void *)dev; | |
781 | ||
782 | geo->heads = nftl->heads; | |
783 | geo->sectors = nftl->sectors; | |
784 | geo->cylinders = nftl->cylinders; | |
785 | ||
786 | return 0; | |
787 | } | |
788 | ||
789 | /**************************************************************************** | |
790 | * | |
791 | * Module stuff | |
792 | * | |
793 | ****************************************************************************/ | |
794 | ||
795 | ||
796 | static struct mtd_blktrans_ops nftl_tr = { | |
797 | .name = "nftl", | |
798 | .major = NFTL_MAJOR, | |
799 | .part_bits = NFTL_PARTN_BITS, | |
19187672 | 800 | .blksize = 512, |
1da177e4 LT |
801 | .getgeo = nftl_getgeo, |
802 | .readsect = nftl_readblock, | |
803 | #ifdef CONFIG_NFTL_RW | |
804 | .writesect = nftl_writeblock, | |
805 | #endif | |
806 | .add_mtd = nftl_add_mtd, | |
807 | .remove_dev = nftl_remove_dev, | |
808 | .owner = THIS_MODULE, | |
809 | }; | |
810 | ||
811 | extern char nftlmountrev[]; | |
812 | ||
813 | static int __init init_nftl(void) | |
814 | { | |
97894cda | 815 | printk(KERN_INFO "NFTL driver: nftlcore.c $Revision: 1.98 $, nftlmount.c %s\n", nftlmountrev); |
1da177e4 LT |
816 | |
817 | return register_mtd_blktrans(&nftl_tr); | |
818 | } | |
819 | ||
820 | static void __exit cleanup_nftl(void) | |
821 | { | |
822 | deregister_mtd_blktrans(&nftl_tr); | |
823 | } | |
824 | ||
825 | module_init(init_nftl); | |
826 | module_exit(cleanup_nftl); | |
827 | ||
828 | MODULE_LICENSE("GPL"); | |
829 | MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>, Fabrice Bellard <fabrice.bellard@netgem.com> et al."); | |
830 | MODULE_DESCRIPTION("Support code for NAND Flash Translation Layer, used on M-Systems DiskOnChip 2000 and Millennium"); |