2 * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
4 * Copyright (C) 2002-2007 Aleph One Ltd.
5 * for Toby Churchill Ltd and Brightstar Engineering
7 * Created by Charles Manning <charles@aleph1.co.uk>
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
17 #include "yaffs_guts.h"
18 #include "yaffs_tagscompat.h"
19 #include "yaffs_ecc.h"
21 static void yaffs_HandleReadDataError(yaffs_Device * dev, int chunkInNAND);
23 static void yaffs_CheckWrittenBlock(yaffs_Device * dev, int chunkInNAND);
24 static void yaffs_HandleWriteChunkOk(yaffs_Device * dev, int chunkInNAND,
26 const yaffs_Spare * spare);
27 static void yaffs_HandleUpdateChunk(yaffs_Device * dev, int chunkInNAND,
28 const yaffs_Spare * spare);
29 static void yaffs_HandleWriteChunkError(yaffs_Device * dev, int chunkInNAND);
32 static const char yaffs_countBitsTable[256] = {
33 0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4,
34 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
35 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
36 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
37 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
38 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
39 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
40 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
41 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
42 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
43 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
44 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
45 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
46 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
47 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
48 4, 5, 5, 6, 5, 6, 6, 7, 5, 6, 6, 7, 6, 7, 7, 8
51 int yaffs_CountBits(__u8 x)
54 retVal = yaffs_countBitsTable[x];
58 /********** Tags ECC calculations *********/
60 void yaffs_CalcECC(const __u8 * data, yaffs_Spare * spare)
62 yaffs_ECCCalculate(data, spare->ecc1);
63 yaffs_ECCCalculate(&data[256], spare->ecc2);
66 void yaffs_CalcTagsECC(yaffs_Tags * tags)
68 /* Calculate an ecc */
70 unsigned char *b = ((yaffs_TagsUnion *) tags)->asBytes;
77 for (i = 0; i < 8; i++) {
78 for (j = 1; j & 0xff; j <<= 1) {
90 int yaffs_CheckECCOnTags(yaffs_Tags * tags)
92 unsigned ecc = tags->ecc;
94 yaffs_CalcTagsECC(tags);
98 if (ecc && ecc <= 64) {
99 /* TODO: Handle the failure better. Retire? */
100 unsigned char *b = ((yaffs_TagsUnion *) tags)->asBytes;
104 b[ecc / 8] ^= (1 << (ecc & 7));
106 /* Now recvalc the ecc */
107 yaffs_CalcTagsECC(tags);
109 return 1; /* recovered error */
111 /* Wierd ecc failure value */
112 /* TODO Need to do somethiong here */
113 return -1; /* unrecovered error */
119 /********** Tags **********/
121 static void yaffs_LoadTagsIntoSpare(yaffs_Spare * sparePtr,
122 yaffs_Tags * tagsPtr)
124 yaffs_TagsUnion *tu = (yaffs_TagsUnion *) tagsPtr;
126 yaffs_CalcTagsECC(tagsPtr);
128 sparePtr->tagByte0 = tu->asBytes[0];
129 sparePtr->tagByte1 = tu->asBytes[1];
130 sparePtr->tagByte2 = tu->asBytes[2];
131 sparePtr->tagByte3 = tu->asBytes[3];
132 sparePtr->tagByte4 = tu->asBytes[4];
133 sparePtr->tagByte5 = tu->asBytes[5];
134 sparePtr->tagByte6 = tu->asBytes[6];
135 sparePtr->tagByte7 = tu->asBytes[7];
138 static void yaffs_GetTagsFromSpare(yaffs_Device * dev, yaffs_Spare * sparePtr,
139 yaffs_Tags * tagsPtr)
141 yaffs_TagsUnion *tu = (yaffs_TagsUnion *) tagsPtr;
144 tu->asBytes[0] = sparePtr->tagByte0;
145 tu->asBytes[1] = sparePtr->tagByte1;
146 tu->asBytes[2] = sparePtr->tagByte2;
147 tu->asBytes[3] = sparePtr->tagByte3;
148 tu->asBytes[4] = sparePtr->tagByte4;
149 tu->asBytes[5] = sparePtr->tagByte5;
150 tu->asBytes[6] = sparePtr->tagByte6;
151 tu->asBytes[7] = sparePtr->tagByte7;
153 result = yaffs_CheckECCOnTags(tagsPtr);
156 } else if (result < 0) {
157 dev->tagsEccUnfixed++;
161 static void yaffs_SpareInitialise(yaffs_Spare * spare)
163 memset(spare, 0xFF, sizeof(yaffs_Spare));
166 static int yaffs_WriteChunkToNAND(struct yaffs_DeviceStruct *dev,
167 int chunkInNAND, const __u8 * data,
170 if (chunkInNAND < dev->startBlock * dev->nChunksPerBlock) {
172 (TSTR("**>> yaffs chunk %d is not valid" TENDSTR),
178 return dev->writeChunkToNAND(dev, chunkInNAND, data, spare);
181 static int yaffs_ReadChunkFromNAND(struct yaffs_DeviceStruct *dev,
185 yaffs_ECCResult * eccResult,
186 int doErrorCorrection)
189 yaffs_Spare localSpare;
193 if (!spare && data) {
194 /* If we don't have a real spare, then we use a local one. */
195 /* Need this for the calculation of the ecc */
199 if (!dev->useNANDECC) {
200 retVal = dev->readChunkFromNAND(dev, chunkInNAND, data, spare);
201 if (data && doErrorCorrection) {
202 /* Do ECC correction */
203 /* Todo handle any errors */
204 int eccResult1, eccResult2;
207 yaffs_ECCCalculate(data, calcEcc);
209 yaffs_ECCCorrect(data, spare->ecc1, calcEcc);
210 yaffs_ECCCalculate(&data[256], calcEcc);
212 yaffs_ECCCorrect(&data[256], spare->ecc2, calcEcc);
214 if (eccResult1 > 0) {
217 ("**>>yaffs ecc error fix performed on chunk %d:0"
218 TENDSTR), chunkInNAND));
220 } else if (eccResult1 < 0) {
223 ("**>>yaffs ecc error unfixed on chunk %d:0"
224 TENDSTR), chunkInNAND));
228 if (eccResult2 > 0) {
231 ("**>>yaffs ecc error fix performed on chunk %d:1"
232 TENDSTR), chunkInNAND));
234 } else if (eccResult2 < 0) {
237 ("**>>yaffs ecc error unfixed on chunk %d:1"
238 TENDSTR), chunkInNAND));
242 if (eccResult1 || eccResult2) {
243 /* We had a data problem on this page */
244 yaffs_HandleReadDataError(dev, chunkInNAND);
247 if (eccResult1 < 0 || eccResult2 < 0)
248 *eccResult = YAFFS_ECC_RESULT_UNFIXED;
249 else if (eccResult1 > 0 || eccResult2 > 0)
250 *eccResult = YAFFS_ECC_RESULT_FIXED;
252 *eccResult = YAFFS_ECC_RESULT_NO_ERROR;
255 /* Must allocate enough memory for spare+2*sizeof(int) */
256 /* for ecc results from device. */
257 struct yaffs_NANDSpare nspare;
259 dev->readChunkFromNAND(dev, chunkInNAND, data,
260 (yaffs_Spare *) & nspare);
261 memcpy(spare, &nspare, sizeof(yaffs_Spare));
262 if (data && doErrorCorrection) {
263 if (nspare.eccres1 > 0) {
266 ("**>>mtd ecc error fix performed on chunk %d:0"
267 TENDSTR), chunkInNAND));
268 } else if (nspare.eccres1 < 0) {
271 ("**>>mtd ecc error unfixed on chunk %d:0"
272 TENDSTR), chunkInNAND));
275 if (nspare.eccres2 > 0) {
278 ("**>>mtd ecc error fix performed on chunk %d:1"
279 TENDSTR), chunkInNAND));
280 } else if (nspare.eccres2 < 0) {
283 ("**>>mtd ecc error unfixed on chunk %d:1"
284 TENDSTR), chunkInNAND));
287 if (nspare.eccres1 || nspare.eccres2) {
288 /* We had a data problem on this page */
289 yaffs_HandleReadDataError(dev, chunkInNAND);
292 if (nspare.eccres1 < 0 || nspare.eccres2 < 0)
293 *eccResult = YAFFS_ECC_RESULT_UNFIXED;
294 else if (nspare.eccres1 > 0 || nspare.eccres2 > 0)
295 *eccResult = YAFFS_ECC_RESULT_FIXED;
297 *eccResult = YAFFS_ECC_RESULT_NO_ERROR;
305 static int yaffs_CheckChunkErased(struct yaffs_DeviceStruct *dev,
310 static __u8 cmpbuf[YAFFS_BYTES_PER_CHUNK];
311 static __u8 data[YAFFS_BYTES_PER_CHUNK];
312 /* Might as well always allocate the larger size for */
313 /* dev->useNANDECC == true; */
314 static __u8 spare[sizeof(struct yaffs_NANDSpare)];
316 dev->readChunkFromNAND(dev, chunkInNAND, data, (yaffs_Spare *) spare);
319 memset(cmpbuf, 0xff, YAFFS_BYTES_PER_CHUNK);
323 if (memcmp(cmpbuf, data, YAFFS_BYTES_PER_CHUNK))
325 if (memcmp(cmpbuf, spare, 16))
334 * Functions for robustisizing
337 static void yaffs_HandleReadDataError(yaffs_Device * dev, int chunkInNAND)
339 int blockInNAND = chunkInNAND / dev->nChunksPerBlock;
341 /* Mark the block for retirement */
342 yaffs_GetBlockInfo(dev, blockInNAND)->needsRetiring = 1;
343 T(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
344 (TSTR("**>>Block %d marked for retirement" TENDSTR), blockInNAND));
347 * Just do a garbage collection on the affected block
348 * then retire the block
354 static void yaffs_CheckWrittenBlock(yaffs_Device * dev, int chunkInNAND)
358 static void yaffs_HandleWriteChunkOk(yaffs_Device * dev, int chunkInNAND,
360 const yaffs_Spare * spare)
364 static void yaffs_HandleUpdateChunk(yaffs_Device * dev, int chunkInNAND,
365 const yaffs_Spare * spare)
369 static void yaffs_HandleWriteChunkError(yaffs_Device * dev, int chunkInNAND)
371 int blockInNAND = chunkInNAND / dev->nChunksPerBlock;
373 /* Mark the block for retirement */
374 yaffs_GetBlockInfo(dev, blockInNAND)->needsRetiring = 1;
375 /* Delete the chunk */
376 yaffs_DeleteChunk(dev, chunkInNAND, 1, __LINE__);
379 static int yaffs_VerifyCompare(const __u8 * d0, const __u8 * d1,
380 const yaffs_Spare * s0, const yaffs_Spare * s1)
383 if (memcmp(d0, d1, YAFFS_BYTES_PER_CHUNK) != 0 ||
384 s0->tagByte0 != s1->tagByte0 ||
385 s0->tagByte1 != s1->tagByte1 ||
386 s0->tagByte2 != s1->tagByte2 ||
387 s0->tagByte3 != s1->tagByte3 ||
388 s0->tagByte4 != s1->tagByte4 ||
389 s0->tagByte5 != s1->tagByte5 ||
390 s0->tagByte6 != s1->tagByte6 ||
391 s0->tagByte7 != s1->tagByte7 ||
392 s0->ecc1[0] != s1->ecc1[0] ||
393 s0->ecc1[1] != s1->ecc1[1] ||
394 s0->ecc1[2] != s1->ecc1[2] ||
395 s0->ecc2[0] != s1->ecc2[0] ||
396 s0->ecc2[1] != s1->ecc2[1] || s0->ecc2[2] != s1->ecc2[2]) {
404 int yaffs_TagsCompatabilityWriteChunkWithTagsToNAND(yaffs_Device * dev,
407 const yaffs_ExtendedTags *
413 yaffs_SpareInitialise(&spare);
415 if (eTags->chunkDeleted) {
416 spare.pageStatus = 0;
418 tags.objectId = eTags->objectId;
419 tags.chunkId = eTags->chunkId;
420 tags.byteCount = eTags->byteCount;
421 tags.serialNumber = eTags->serialNumber;
423 if (!dev->useNANDECC && data) {
424 yaffs_CalcECC(data, &spare);
426 yaffs_LoadTagsIntoSpare(&spare, &tags);
430 return yaffs_WriteChunkToNAND(dev, chunkInNAND, data, &spare);
433 int yaffs_TagsCompatabilityReadChunkWithTagsFromNAND(yaffs_Device * dev,
436 yaffs_ExtendedTags * eTags)
441 yaffs_ECCResult eccResult;
443 static yaffs_Spare spareFF;
447 memset(&spareFF, 0xFF, sizeof(spareFF));
451 if (yaffs_ReadChunkFromNAND
452 (dev, chunkInNAND, data, &spare, &eccResult, 1)) {
453 /* eTags may be NULL */
457 (yaffs_CountBits(spare.pageStatus) < 7) ? 1 : 0;
459 eTags->chunkDeleted = deleted;
460 eTags->eccResult = eccResult;
461 eTags->blockBad = 0; /* We're reading it */
462 /* therefore it is not a bad block */
464 (memcmp(&spareFF, &spare, sizeof(spareFF)) !=
467 if (eTags->chunkUsed) {
468 yaffs_GetTagsFromSpare(dev, &spare, &tags);
470 eTags->objectId = tags.objectId;
471 eTags->chunkId = tags.chunkId;
472 eTags->byteCount = tags.byteCount;
473 eTags->serialNumber = tags.serialNumber;
483 int yaffs_TagsCompatabilityMarkNANDBlockBad(struct yaffs_DeviceStruct *dev,
489 memset(&spare, 0xff, sizeof(yaffs_Spare));
491 spare.blockStatus = 'Y';
493 yaffs_WriteChunkToNAND(dev, blockInNAND * dev->nChunksPerBlock, NULL,
495 yaffs_WriteChunkToNAND(dev, blockInNAND * dev->nChunksPerBlock + 1,
502 int yaffs_TagsCompatabilityQueryNANDBlock(struct yaffs_DeviceStruct *dev,
503 int blockNo, yaffs_BlockState *
508 yaffs_Spare spare0, spare1;
509 static yaffs_Spare spareFF;
511 yaffs_ECCResult dummy;
514 memset(&spareFF, 0xFF, sizeof(spareFF));
520 yaffs_ReadChunkFromNAND(dev, blockNo * dev->nChunksPerBlock, NULL,
522 yaffs_ReadChunkFromNAND(dev, blockNo * dev->nChunksPerBlock + 1, NULL,
525 if (yaffs_CountBits(spare0.blockStatus & spare1.blockStatus) < 7)
526 *state = YAFFS_BLOCK_STATE_DEAD;
527 else if (memcmp(&spareFF, &spare0, sizeof(spareFF)) == 0)
528 *state = YAFFS_BLOCK_STATE_EMPTY;
530 *state = YAFFS_BLOCK_STATE_NEEDS_SCANNING;