Example #1
0
int nandmtd1_ReadChunkWithTagsFromNAND(yaffs_Device *dev,
	int chunkInNAND, __u8 *data, yaffs_ExtendedTags *etags)
{
	struct mtd_info *mtd = dev->genericDevice;
	int chunkBytes = dev->nDataBytesPerChunk;
	loff_t addr = ((loff_t)chunkInNAND) * chunkBytes;
	int eccres = YAFFS_ECC_RESULT_NO_ERROR;
	struct mtd_oob_ops ops;
	yaffs_PackedTags1 pt1;
	int retval;
	int deleted;

	memset(&ops, 0, sizeof(ops));
	ops.mode = MTD_OOB_AUTO;
	ops.len = (data) ? chunkBytes : 0;
	ops.ooblen = YTAG1_SIZE;
	ops.datbuf = data;
	ops.oobbuf = (__u8 *)&pt1;

#if (MTD_VERSION_CODE < MTD_VERSION(2, 6, 20))
	
	ops.len = (ops.datbuf) ? ops.len : ops.ooblen;
#endif
	
	retval = mtd->read_oob(mtd, addr, &ops);
	if (retval) {
		yaffs_trace(YAFFS_TRACE_MTD,
			"read_oob failed, chunk %d, mtd error %d\n",
			chunkInNAND, retval);
	}

	switch (retval) {
	case 0:
		
		break;

	case -EUCLEAN:
		
		eccres = YAFFS_ECC_RESULT_FIXED;
		dev->eccFixed++;
		break;

	case -EBADMSG:
		
		dev->eccUnfixed++;
		
	default:
		rettags(etags, YAFFS_ECC_RESULT_UNFIXED, 0);
		etags->blockBad = (mtd->block_isbad)(mtd, addr);
		return YAFFS_FAIL;
	}

	
	if (yaffs_CheckFF((__u8 *)&pt1, 8)) {
		
		return rettags(etags, YAFFS_ECC_RESULT_NO_ERROR, YAFFS_OK);
	}

#ifndef CONFIG_YAFFS_9BYTE_TAGS
	
	deleted = !pt1.deleted;
	pt1.deleted = 1;
#else
	deleted = (yaffs_CountBits(((__u8 *)&pt1)[8]) < 7);
#endif

	
	retval = yaffs_CheckECCOnTags((yaffs_Tags *)&pt1);
	switch (retval) {
	case 0:
		
		break;
	case 1:
		
		dev->tagsEccFixed++;
		if (eccres == YAFFS_ECC_RESULT_NO_ERROR)
			eccres = YAFFS_ECC_RESULT_FIXED;
		break;
	default:
		
		dev->tagsEccUnfixed++;
		return rettags(etags, YAFFS_ECC_RESULT_UNFIXED, YAFFS_FAIL);
	}

	
	pt1.shouldBeFF = 0xFFFFFFFF;
	yaffs_UnpackTags1(etags, &pt1);
	etags->eccResult = eccres;

	
	etags->chunkDeleted = deleted;
	return YAFFS_OK;
}
Example #2
0
/* Read a chunk (page) from NAND.
 *
 * Caller expects ExtendedTags data to be usable even on error; that is,
 * all members except eccResult and blockBad are zeroed.
 *
 *  - Check ECC results for data (if applicable)
 *  - Check for blank/erased block (return empty ExtendedTags if blank)
 *  - Check the PackedTags1 mini-ECC (correct if necessary/possible)
 *  - Convert PackedTags1 to ExtendedTags
 *  - Update eccResult and blockBad members to refect state.
 *
 * Returns YAFFS_OK or YAFFS_FAIL.
 */
int nandmtd1_ReadChunkWithTagsFromNAND(yaffs_Device *dev,
	int chunkInNAND, __u8 *data, yaffs_ExtendedTags *etags)
{
	struct mtd_info *mtd = yaffs_DeviceToMtd(dev);
	int chunkBytes = dev->nDataBytesPerChunk;
	loff_t addr = ((loff_t)chunkInNAND) * chunkBytes;
	int eccres = YAFFS_ECC_RESULT_NO_ERROR;
	struct mtd_oob_ops ops;
	yaffs_PackedTags1 pt1;
	int retval;
	int deleted;

	memset(&ops, 0, sizeof(ops));
	ops.mode = MTD_OOB_AUTO;
	ops.len = (data) ? chunkBytes : 0;
	ops.ooblen = YTAG1_SIZE;
	ops.datbuf = data;
	ops.oobbuf = (__u8 *)&pt1;

#if (MTD_VERSION_CODE < MTD_VERSION(2, 6, 20))
	/* In MTD 2.6.18 to 2.6.19 nand_base.c:nand_do_read_oob() has a bug;
	 * help it out with ops.len = ops.ooblen when ops.datbuf == NULL.
	 */
	ops.len = (ops.datbuf) ? ops.len : ops.ooblen;
#endif
	/* Read page and oob using MTD.
	 * Check status and determine ECC result.
	 */
	retval = mtd->read_oob(mtd, addr, &ops);
	if (retval) {
		T(YAFFS_TRACE_MTD,
			(TSTR("read_oob failed, chunk %d, mtd error %d"TENDSTR),
			chunkInNAND, retval));
	}

	switch (retval) {
	case 0:
		/* no error */
		break;

	case -EUCLEAN:
		/* MTD's ECC fixed the data */
		eccres = YAFFS_ECC_RESULT_FIXED;
		dev->eccFixed++;
		break;

	case -EBADMSG:
		/* MTD's ECC could not fix the data */
		dev->eccUnfixed++;
		/* fall into... */
	default:
		rettags(etags, YAFFS_ECC_RESULT_UNFIXED, 0);
		etags->blockBad = (mtd->block_isbad)(mtd, addr);
		return YAFFS_FAIL;
	}

	/* Check for a blank/erased chunk.
	 */
	if (yaffs_CheckFF((__u8 *)&pt1, 8)) {
		/* when blank, upper layers want eccResult to be <= NO_ERROR */
		return rettags(etags, YAFFS_ECC_RESULT_NO_ERROR, YAFFS_OK);
	}

#ifndef CONFIG_YAFFS_9BYTE_TAGS
	/* Read deleted status (bit) then return it to it's non-deleted
	 * state before performing tags mini-ECC check. pt1.deleted is
	 * inverted.
	 */
	deleted = !pt1.deleted;
	pt1.deleted = 1;
#else
	deleted = (yaffs_CountBits(((__u8 *)&pt1)[8]) < 7);
#endif

	/* Check the packed tags mini-ECC and correct if necessary/possible.
	 */
	retval = yaffs_CheckECCOnTags((yaffs_Tags *)&pt1);
	switch (retval) {
	case 0:
		/* no tags error, use MTD result */
		break;
	case 1:
		/* recovered tags-ECC error */
		dev->tagsEccFixed++;
		if (eccres == YAFFS_ECC_RESULT_NO_ERROR)
			eccres = YAFFS_ECC_RESULT_FIXED;
		break;
	default:
		/* unrecovered tags-ECC error */
		dev->tagsEccUnfixed++;
		return rettags(etags, YAFFS_ECC_RESULT_UNFIXED, YAFFS_FAIL);
	}

	/* Unpack the tags to extended form and set ECC result.
	 * [set shouldBeFF just to keep yaffs_UnpackTags1 happy]
	 */
	pt1.shouldBeFF = 0xFFFFFFFF;
	yaffs_UnpackTags1(etags, &pt1);
	etags->eccResult = eccres;

	/* Set deleted state */
	etags->chunkDeleted = deleted;
	return YAFFS_OK;
}