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