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/*
* YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
*
* Copyright (C) 2002-2007 Aleph One Ltd.
* for Toby Churchill Ltd and Brightstar Engineering
*
* Created by Charles Manning <charles@aleph1.co.uk>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include "yaffs_guts.h"
#include "yaffs_tagscompat.h"
#include "yaffs_ecc.h"
#include "yaffs_getblockinfo.h"
static void yaffs_HandleReadDataError(yaffs_Device *dev, int chunkInNAND);
#ifdef NOTYET
static void yaffs_CheckWrittenBlock(yaffs_Device *dev, int chunkInNAND);
static void yaffs_HandleWriteChunkOk(yaffs_Device *dev, int chunkInNAND,
const __u8 *data,
const yaffs_Spare *spare);
static void yaffs_HandleUpdateChunk(yaffs_Device *dev, int chunkInNAND,
const yaffs_Spare *spare);
static void yaffs_HandleWriteChunkError(yaffs_Device *dev, int chunkInNAND);
#endif
static const char yaffs_countBitsTable[256] = {
0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4,
1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
4, 5, 5, 6, 5, 6, 6, 7, 5, 6, 6, 7, 6, 7, 7, 8
};
int yaffs_CountBits(__u8 x)
{
int retVal;
retVal = yaffs_countBitsTable[x];
return retVal;
}
/********** Tags ECC calculations *********/
void yaffs_CalcECC(const __u8 *data, yaffs_Spare *spare)
{
yaffs_ECCCalculate(data, spare->ecc1);
yaffs_ECCCalculate(&data[256], spare->ecc2);
}
void yaffs_CalcTagsECC(yaffs_Tags *tags)
{
/* Calculate an ecc */
unsigned char *b = ((yaffs_TagsUnion *) tags)->asBytes;
unsigned i, j;
unsigned ecc = 0;
unsigned bit = 0;
tags->ecc = 0;
for (i = 0; i < 8; i++) {
for (j = 1; j & 0xff; j <<= 1) {
bit++;
if (b[i] & j)
ecc ^= bit;
}
}
tags->ecc = ecc;
}
int yaffs_CheckECCOnTags(yaffs_Tags *tags)
{
unsigned ecc = tags->ecc;
yaffs_CalcTagsECC(tags);
ecc ^= tags->ecc;
if (ecc && ecc <= 64) {
/* TODO: Handle the failure better. Retire? */
unsigned char *b = ((yaffs_TagsUnion *) tags)->asBytes;
ecc--;
b[ecc / 8] ^= (1 << (ecc & 7));
/* Now recvalc the ecc */
yaffs_CalcTagsECC(tags);
return 1; /* recovered error */
} else if (ecc) {
/* Wierd ecc failure value */
/* TODO Need to do somethiong here */
return -1; /* unrecovered error */
}
return 0;
}
/********** Tags **********/
static void yaffs_LoadTagsIntoSpare(yaffs_Spare *sparePtr,
yaffs_Tags *tagsPtr)
{
yaffs_TagsUnion *tu = (yaffs_TagsUnion *) tagsPtr;
yaffs_CalcTagsECC(tagsPtr);
sparePtr->tagByte0 = tu->asBytes[0];
sparePtr->tagByte1 = tu->asBytes[1];
sparePtr->tagByte2 = tu->asBytes[2];
sparePtr->tagByte3 = tu->asBytes[3];
sparePtr->tagByte4 = tu->asBytes[4];
sparePtr->tagByte5 = tu->asBytes[5];
sparePtr->tagByte6 = tu->asBytes[6];
sparePtr->tagByte7 = tu->asBytes[7];
}
static void yaffs_GetTagsFromSpare(yaffs_Device *dev, yaffs_Spare *sparePtr,
yaffs_Tags *tagsPtr)
{
yaffs_TagsUnion *tu = (yaffs_TagsUnion *) tagsPtr;
int result;
tu->asBytes[0] = sparePtr->tagByte0;
tu->asBytes[1] = sparePtr->tagByte1;
tu->asBytes[2] = sparePtr->tagByte2;
tu->asBytes[3] = sparePtr->tagByte3;
tu->asBytes[4] = sparePtr->tagByte4;
tu->asBytes[5] = sparePtr->tagByte5;
tu->asBytes[6] = sparePtr->tagByte6;
tu->asBytes[7] = sparePtr->tagByte7;
result = yaffs_CheckECCOnTags(tagsPtr);
if (result > 0)
dev->tagsEccFixed++;
else if (result < 0)
dev->tagsEccUnfixed++;
}
static void yaffs_SpareInitialise(yaffs_Spare *spare)
{
memset(spare, 0xFF, sizeof(yaffs_Spare));
}
static int yaffs_WriteChunkToNAND(struct yaffs_DeviceStruct *dev,
int chunkInNAND, const __u8 *data,
yaffs_Spare *spare)
{
if (chunkInNAND < dev->startBlock * dev->nChunksPerBlock) {
T(YAFFS_TRACE_ERROR,
(TSTR("**>> yaffs chunk %d is not valid" TENDSTR),
chunkInNAND));
return YAFFS_FAIL;
}
return dev->writeChunkToNAND(dev, chunkInNAND, data, spare);
}
static int yaffs_ReadChunkFromNAND(struct yaffs_DeviceStruct *dev,
int chunkInNAND,
__u8 *data,
yaffs_Spare *spare,
yaffs_ECCResult *eccResult,
int doErrorCorrection)
{
int retVal;
yaffs_Spare localSpare;
if (!spare && data) {
/* If we don't have a real spare, then we use a local one. */
/* Need this for the calculation of the ecc */
spare = &localSpare;
}
if (!dev->useNANDECC) {
retVal = dev->readChunkFromNAND(dev, chunkInNAND, data, spare);
if (data && doErrorCorrection) {
/* Do ECC correction */
/* Todo handle any errors */
int eccResult1, eccResult2;
__u8 calcEcc[3];
yaffs_ECCCalculate(data, calcEcc);
eccResult1 =
yaffs_ECCCorrect(data, spare->ecc1, calcEcc);
yaffs_ECCCalculate(&data[256], calcEcc);
eccResult2 =
yaffs_ECCCorrect(&data[256], spare->ecc2, calcEcc);
if (eccResult1 > 0) {
T(YAFFS_TRACE_ERROR,
(TSTR
("**>>yaffs ecc error fix performed on chunk %d:0"
TENDSTR), chunkInNAND));
dev->eccFixed++;
} else if (eccResult1 < 0) {
T(YAFFS_TRACE_ERROR,
(TSTR
("**>>yaffs ecc error unfixed on chunk %d:0"
TENDSTR), chunkInNAND));
dev->eccUnfixed++;
}
if (eccResult2 > 0) {
T(YAFFS_TRACE_ERROR,
(TSTR
("**>>yaffs ecc error fix performed on chunk %d:1"
TENDSTR), chunkInNAND));
dev->eccFixed++;
} else if (eccResult2 < 0) {
T(YAFFS_TRACE_ERROR,
(TSTR
("**>>yaffs ecc error unfixed on chunk %d:1"
TENDSTR), chunkInNAND));
dev->eccUnfixed++;
}
if (eccResult1 || eccResult2) {
/* We had a data problem on this page */
yaffs_HandleReadDataError(dev, chunkInNAND);
}
if (eccResult1 < 0 || eccResult2 < 0)
*eccResult = YAFFS_ECC_RESULT_UNFIXED;
else if (eccResult1 > 0 || eccResult2 > 0)
*eccResult = YAFFS_ECC_RESULT_FIXED;
else
*eccResult = YAFFS_ECC_RESULT_NO_ERROR;
}
} else {
/* Must allocate enough memory for spare+2*sizeof(int) */
/* for ecc results from device. */
struct yaffs_NANDSpare nspare;
memset(&nspare, 0, sizeof(nspare));
retVal = dev->readChunkFromNAND(dev, chunkInNAND, data,
(yaffs_Spare *) &nspare);
memcpy(spare, &nspare, sizeof(yaffs_Spare));
if (data && doErrorCorrection) {
if (nspare.eccres1 > 0) {
T(YAFFS_TRACE_ERROR,
(TSTR
("**>>mtd ecc error fix performed on chunk %d:0"
TENDSTR), chunkInNAND));
} else if (nspare.eccres1 < 0) {
T(YAFFS_TRACE_ERROR,
(TSTR
("**>>mtd ecc error unfixed on chunk %d:0"
TENDSTR), chunkInNAND));
}
if (nspare.eccres2 > 0) {
T(YAFFS_TRACE_ERROR,
(TSTR
("**>>mtd ecc error fix performed on chunk %d:1"
TENDSTR), chunkInNAND));
} else if (nspare.eccres2 < 0) {
T(YAFFS_TRACE_ERROR,
(TSTR
("**>>mtd ecc error unfixed on chunk %d:1"
TENDSTR), chunkInNAND));
}
if (nspare.eccres1 || nspare.eccres2) {
/* We had a data problem on this page */
yaffs_HandleReadDataError(dev, chunkInNAND);
}
if (nspare.eccres1 < 0 || nspare.eccres2 < 0)
*eccResult = YAFFS_ECC_RESULT_UNFIXED;
else if (nspare.eccres1 > 0 || nspare.eccres2 > 0)
*eccResult = YAFFS_ECC_RESULT_FIXED;
else
*eccResult = YAFFS_ECC_RESULT_NO_ERROR;
}
}
return retVal;
}
#ifdef NOTYET
static int yaffs_CheckChunkErased(struct yaffs_DeviceStruct *dev,
int chunkInNAND)
{
static int init;
static __u8 cmpbuf[YAFFS_BYTES_PER_CHUNK];
static __u8 data[YAFFS_BYTES_PER_CHUNK];
/* Might as well always allocate the larger size for */
/* dev->useNANDECC == true; */
static __u8 spare[sizeof(struct yaffs_NANDSpare)];
dev->readChunkFromNAND(dev, chunkInNAND, data, (yaffs_Spare *) spare);
if (!init) {
memset(cmpbuf, 0xff, YAFFS_BYTES_PER_CHUNK);
init = 1;
}
if (memcmp(cmpbuf, data, YAFFS_BYTES_PER_CHUNK))
return YAFFS_FAIL;
if (memcmp(cmpbuf, spare, 16))
return YAFFS_FAIL;
return YAFFS_OK;
}
#endif
/*
* Functions for robustisizing
*/
static void yaffs_HandleReadDataError(yaffs_Device *dev, int chunkInNAND)
{
int blockInNAND = chunkInNAND / dev->nChunksPerBlock;
/* Mark the block for retirement */
yaffs_GetBlockInfo(dev, blockInNAND + dev->blockOffset)->needsRetiring = 1;
T(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
(TSTR("**>>Block %d marked for retirement" TENDSTR), blockInNAND));
/* TODO:
* Just do a garbage collection on the affected block
* then retire the block
* NB recursion
*/
}
#ifdef NOTYET
static void yaffs_CheckWrittenBlock(yaffs_Device *dev, int chunkInNAND)
{
}
static void yaffs_HandleWriteChunkOk(yaffs_Device *dev, int chunkInNAND,
const __u8 *data,
const yaffs_Spare *spare)
{
}
static void yaffs_HandleUpdateChunk(yaffs_Device *dev, int chunkInNAND,
const yaffs_Spare *spare)
{
}
static void yaffs_HandleWriteChunkError(yaffs_Device *dev, int chunkInNAND)
{
int blockInNAND = chunkInNAND / dev->nChunksPerBlock;
/* Mark the block for retirement */
yaffs_GetBlockInfo(dev, blockInNAND)->needsRetiring = 1;
/* Delete the chunk */
yaffs_DeleteChunk(dev, chunkInNAND, 1, __LINE__);
}
static int yaffs_VerifyCompare(const __u8 *d0, const __u8 *d1,
const yaffs_Spare *s0, const yaffs_Spare *s1)
{
if (memcmp(d0, d1, YAFFS_BYTES_PER_CHUNK) != 0 ||
s0->tagByte0 != s1->tagByte0 ||
s0->tagByte1 != s1->tagByte1 ||
s0->tagByte2 != s1->tagByte2 ||
s0->tagByte3 != s1->tagByte3 ||
s0->tagByte4 != s1->tagByte4 ||
s0->tagByte5 != s1->tagByte5 ||
s0->tagByte6 != s1->tagByte6 ||
s0->tagByte7 != s1->tagByte7 ||
s0->ecc1[0] != s1->ecc1[0] ||
s0->ecc1[1] != s1->ecc1[1] ||
s0->ecc1[2] != s1->ecc1[2] ||
s0->ecc2[0] != s1->ecc2[0] ||
s0->ecc2[1] != s1->ecc2[1] || s0->ecc2[2] != s1->ecc2[2]) {
return 0;
}
return 1;
}
#endif /* NOTYET */
int yaffs_TagsCompatabilityWriteChunkWithTagsToNAND(yaffs_Device *dev,
int chunkInNAND,
const __u8 *data,
const yaffs_ExtendedTags *eTags)
{
yaffs_Spare spare;
yaffs_Tags tags;
yaffs_SpareInitialise(&spare);
if (eTags->chunkDeleted)
spare.pageStatus = 0;
else {
tags.objectId = eTags->objectId;
tags.chunkId = eTags->chunkId;
tags.byteCountLSB = eTags->byteCount & 0x3ff;
if (dev->nDataBytesPerChunk >= 1024)
tags.byteCountMSB = (eTags->byteCount >> 10) & 3;
else
tags.byteCountMSB = 3;
tags.serialNumber = eTags->serialNumber;
if (!dev->useNANDECC && data)
yaffs_CalcECC(data, &spare);
yaffs_LoadTagsIntoSpare(&spare, &tags);
}
return yaffs_WriteChunkToNAND(dev, chunkInNAND, data, &spare);
}
int yaffs_TagsCompatabilityReadChunkWithTagsFromNAND(yaffs_Device *dev,
int chunkInNAND,
__u8 *data,
yaffs_ExtendedTags *eTags)
{
yaffs_Spare spare;
yaffs_Tags tags;
yaffs_ECCResult eccResult = YAFFS_ECC_RESULT_UNKNOWN;
static yaffs_Spare spareFF;
static int init;
if (!init) {
memset(&spareFF, 0xFF, sizeof(spareFF));
init = 1;
}
if (yaffs_ReadChunkFromNAND
(dev, chunkInNAND, data, &spare, &eccResult, 1)) {
/* eTags may be NULL */
if (eTags) {
int deleted =
(yaffs_CountBits(spare.pageStatus) < 7) ? 1 : 0;
eTags->chunkDeleted = deleted;
eTags->eccResult = eccResult;
eTags->blockBad = 0; /* We're reading it */
/* therefore it is not a bad block */
eTags->chunkUsed =
(memcmp(&spareFF, &spare, sizeof(spareFF)) !=
0) ? 1 : 0;
if (eTags->chunkUsed) {
yaffs_GetTagsFromSpare(dev, &spare, &tags);
eTags->objectId = tags.objectId;
eTags->chunkId = tags.chunkId;
eTags->byteCount = tags.byteCountLSB;
if (dev->nDataBytesPerChunk >= 1024)
eTags->byteCount |= (((unsigned) tags.byteCountMSB) << 10);
eTags->serialNumber = tags.serialNumber;
}
}
return YAFFS_OK;
} else {
return YAFFS_FAIL;
}
}
int yaffs_TagsCompatabilityMarkNANDBlockBad(struct yaffs_DeviceStruct *dev,
int blockInNAND)
{
yaffs_Spare spare;
memset(&spare, 0xff, sizeof(yaffs_Spare));
spare.blockStatus = 'Y';
yaffs_WriteChunkToNAND(dev, blockInNAND * dev->nChunksPerBlock, NULL,
&spare);
yaffs_WriteChunkToNAND(dev, blockInNAND * dev->nChunksPerBlock + 1,
NULL, &spare);
return YAFFS_OK;
}
int yaffs_TagsCompatabilityQueryNANDBlock(struct yaffs_DeviceStruct *dev,
int blockNo,
yaffs_BlockState *state,
__u32 *sequenceNumber)
{
yaffs_Spare spare0, spare1;
static yaffs_Spare spareFF;
static int init;
yaffs_ECCResult dummy;
if (!init) {
memset(&spareFF, 0xFF, sizeof(spareFF));
init = 1;
}
*sequenceNumber = 0;
yaffs_ReadChunkFromNAND(dev, blockNo * dev->nChunksPerBlock, NULL,
&spare0, &dummy, 1);
yaffs_ReadChunkFromNAND(dev, blockNo * dev->nChunksPerBlock + 1, NULL,
&spare1, &dummy, 1);
if (yaffs_CountBits(spare0.blockStatus & spare1.blockStatus) < 7)
*state = YAFFS_BLOCK_STATE_DEAD;
else if (memcmp(&spareFF, &spare0, sizeof(spareFF)) == 0)
*state = YAFFS_BLOCK_STATE_EMPTY;
else
*state = YAFFS_BLOCK_STATE_NEEDS_SCANNING;
return YAFFS_OK;
}
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