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-rw-r--r--fs/yaffs2/yaffs_mtdif1.c369
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diff --git a/fs/yaffs2/yaffs_mtdif1.c b/fs/yaffs2/yaffs_mtdif1.c
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--- a/fs/yaffs2/yaffs_mtdif1.c
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-/*
- * YAFFS: Yet another FFS. A NAND-flash specific file system.
- * yaffs_mtdif1.c NAND mtd interface functions for small-page NAND.
- *
- * Copyright (C) 2002 Aleph One Ltd.
- * for Toby Churchill Ltd and Brightstar Engineering
- *
- * 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.
- */
-
-/*
- * This module provides the interface between yaffs_nand.c and the
- * MTD API. This version is used when the MTD interface supports the
- * 'mtd_oob_ops' style calls to read_oob and write_oob, circa 2.6.17,
- * and we have small-page NAND device.
- *
- * These functions are invoked via function pointers in yaffs_nand.c.
- * This replaces functionality provided by functions in yaffs_mtdif.c
- * and the yaffs_TagsCompatability functions in yaffs_tagscompat.c that are
- * called in yaffs_mtdif.c when the function pointers are NULL.
- * We assume the MTD layer is performing ECC (useNANDECC is true).
- */
-
-#include "yportenv.h"
-#include "yaffs_guts.h"
-#include "yaffs_packedtags1.h"
-#include "yaffs_tagscompat.h" // for yaffs_CalcTagsECC
-
-#include "linux/kernel.h"
-#include "linux/version.h"
-#include "linux/types.h"
-#include "linux/mtd/mtd.h"
-
-/* Don't compile this module if we don't have MTD's mtd_oob_ops interface */
-#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,17))
-
-const char *yaffs_mtdif1_c_version = "$Id: yaffs_mtdif1.c,v 1.5 2007/10/29 14:59:57 imcd Exp $";
-
-#ifndef CONFIG_YAFFS_9BYTE_TAGS
-# define YTAG1_SIZE 8
-#else
-# define YTAG1_SIZE 9
-#endif
-
-#if 0
-/* Use the following nand_ecclayout with MTD when using
- * CONFIG_YAFFS_9BYTE_TAGS and the older on-NAND tags layout.
- * If you have existing Yaffs images and the byte order differs from this,
- * adjust 'oobfree' to match your existing Yaffs data.
- *
- * This nand_ecclayout scatters/gathers to/from the old-yaffs layout with the
- * pageStatus byte (at NAND spare offset 4) scattered/gathered from/to
- * the 9th byte.
- *
- * Old-style on-NAND format: T0,T1,T2,T3,P,B,T4,T5,E0,E1,E2,T6,T7,E3,E4,E5
- * We have/need PackedTags1 plus pageStatus: T0,T1,T2,T3,T4,T5,T6,T7,P
- * where Tn are the tag bytes, En are MTD's ECC bytes, P is the pageStatus
- * byte and B is the small-page bad-block indicator byte.
- */
-static struct nand_ecclayout nand_oob_16 = {
- .eccbytes = 6,
- .eccpos = { 8, 9, 10, 13, 14, 15 },
- .oobavail = 9,
- .oobfree = { { 0, 4 }, { 6, 2 }, { 11, 2 }, { 4, 1 } }
-};
-#endif
-
-/* Write a chunk (page) of data to NAND.
- *
- * Caller always provides ExtendedTags data which are converted to a more
- * compact (packed) form for storage in NAND. A mini-ECC runs over the
- * contents of the tags meta-data; used to valid the tags when read.
- *
- * - Pack ExtendedTags to PackedTags1 form
- * - Compute mini-ECC for PackedTags1
- * - Write data and packed tags to NAND.
- *
- * Note: Due to the use of the PackedTags1 meta-data which does not include
- * a full sequence number (as found in the larger PackedTags2 form) it is
- * necessary for Yaffs to re-write a chunk/page (just once) to mark it as
- * discarded and dirty. This is not ideal: newer NAND parts are supposed
- * to be written just once. When Yaffs performs this operation, this
- * function is called with a NULL data pointer -- calling MTD write_oob
- * without data is valid usage (2.6.17).
- *
- * Any underlying MTD error results in YAFFS_FAIL.
- * Returns YAFFS_OK or YAFFS_FAIL.
- */
-int nandmtd1_WriteChunkWithTagsToNAND(yaffs_Device *dev,
- int chunkInNAND, const __u8 * data, const yaffs_ExtendedTags * etags)
-{
- struct mtd_info * mtd = dev->genericDevice;
- int chunkBytes = dev->nDataBytesPerChunk;
- loff_t addr = ((loff_t)chunkInNAND) * chunkBytes;
- struct mtd_oob_ops ops;
- yaffs_PackedTags1 pt1;
- int retval;
-
- /* we assume that PackedTags1 and yaffs_Tags are compatible */
- compile_time_assertion(sizeof(yaffs_PackedTags1) == 12);
- compile_time_assertion(sizeof(yaffs_Tags) == 8);
-
- dev->nPageWrites++;
-
- yaffs_PackTags1(&pt1, etags);
- yaffs_CalcTagsECC((yaffs_Tags *)&pt1);
-
- /* When deleting a chunk, the upper layer provides only skeletal
- * etags, one with chunkDeleted set. However, we need to update the
- * tags, not erase them completely. So we use the NAND write property
- * that only zeroed-bits stick and set tag bytes to all-ones and
- * zero just the (not) deleted bit.
- */
-#ifndef CONFIG_YAFFS_9BYTE_TAGS
- if (etags->chunkDeleted) {
- memset(&pt1, 0xff, 8);
- /* clear delete status bit to indicate deleted */
- pt1.deleted = 0;
- }
-#else
- ((__u8 *)&pt1)[8] = 0xff;
- if (etags->chunkDeleted) {
- memset(&pt1, 0xff, 8);
- /* zero pageStatus byte to indicate deleted */
- ((__u8 *)&pt1)[8] = 0;
- }
-#endif
-
- memset(&ops, 0, sizeof(ops));
- ops.mode = MTD_OOB_AUTO;
- ops.len = (data) ? chunkBytes : 0;
- ops.ooblen = YTAG1_SIZE;
- ops.datbuf = (__u8 *)data;
- ops.oobbuf = (__u8 *)&pt1;
-
- retval = mtd->write_oob(mtd, addr, &ops);
- if (retval) {
- yaffs_trace(YAFFS_TRACE_MTD,
- "write_oob failed, chunk %d, mtd error %d\n",
- chunkInNAND, retval);
- }
- return retval ? YAFFS_FAIL : YAFFS_OK;
-}
-
-/* Return with empty ExtendedTags but add eccResult.
- */
-static int rettags(yaffs_ExtendedTags * etags, int eccResult, int retval)
-{
- if (etags) {
- memset(etags, 0, sizeof(*etags));
- etags->eccResult = eccResult;
- }
- return retval;
-}
-
-/* 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 = 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;
-
- dev->nPageReads++;
-
- 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 (LINUX_VERSION_CODE < KERNEL_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) {
- yaffs_trace(YAFFS_TRACE_MTD,
- "read_oob failed, chunk %d, mtd error %d\n",
- 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;
-}
-
-/* Mark a block bad.
- *
- * This is a persistant state.
- * Use of this function should be rare.
- *
- * Returns YAFFS_OK or YAFFS_FAIL.
- */
-int nandmtd1_MarkNANDBlockBad(struct yaffs_DeviceStruct *dev, int blockNo)
-{
- struct mtd_info * mtd = dev->genericDevice;
- int blocksize = dev->nChunksPerBlock * dev->nDataBytesPerChunk;
- int retval;
-
- yaffs_trace(YAFFS_TRACE_BAD_BLOCKS, "marking block %d bad\n", blockNo);
-
- retval = mtd->block_markbad(mtd, (loff_t)blocksize * blockNo);
- return (retval) ? YAFFS_FAIL : YAFFS_OK;
-}
-
-/* Check any MTD prerequists.
- *
- * Returns YAFFS_OK or YAFFS_FAIL.
- */
-static int nandmtd1_TestPrerequists(struct mtd_info * mtd)
-{
- /* 2.6.18 has mtd->ecclayout->oobavail */
- /* 2.6.21 has mtd->ecclayout->oobavail and mtd->oobavail */
- int oobavail = mtd->ecclayout->oobavail;
-
- if (oobavail < YTAG1_SIZE) {
- yaffs_trace(YAFFS_TRACE_ERROR,
- "mtd device has only %d bytes for tags, need %d\n",
- oobavail, YTAG1_SIZE);
- return YAFFS_FAIL;
- }
- return YAFFS_OK;
-}
-
-/* Query for the current state of a specific block.
- *
- * Examine the tags of the first chunk of the block and return the state:
- * - YAFFS_BLOCK_STATE_DEAD, the block is marked bad
- * - YAFFS_BLOCK_STATE_NEEDS_SCANNING, the block is in use
- * - YAFFS_BLOCK_STATE_EMPTY, the block is clean
- *
- * Always returns YAFFS_OK.
- */
-int nandmtd1_QueryNANDBlock(struct yaffs_DeviceStruct *dev, int blockNo,
- yaffs_BlockState * pState, int *pSequenceNumber)
-{
- struct mtd_info * mtd = dev->genericDevice;
- int chunkNo = blockNo * dev->nChunksPerBlock;
- loff_t addr = (loff_t)chunkNo * dev->nDataBytesPerChunk;
- yaffs_ExtendedTags etags;
- int state = YAFFS_BLOCK_STATE_DEAD;
- int seqnum = 0;
- int retval;
-
- /* We don't yet have a good place to test for MTD config prerequists.
- * Do it here as we are called during the initial scan.
- */
- if (nandmtd1_TestPrerequists(mtd) != YAFFS_OK) {
- return YAFFS_FAIL;
- }
-
- retval = nandmtd1_ReadChunkWithTagsFromNAND(dev, chunkNo, NULL, &etags);
- etags.blockBad = (mtd->block_isbad)(mtd, addr);
- if (etags.blockBad) {
- yaffs_trace(YAFFS_TRACE_BAD_BLOCKS,
- "block %d is marked bad\n", blockNo);
- state = YAFFS_BLOCK_STATE_DEAD;
- }
- else if (etags.eccResult != YAFFS_ECC_RESULT_NO_ERROR) {
- /* bad tags, need to look more closely */
- state = YAFFS_BLOCK_STATE_NEEDS_SCANNING;
- }
- else if (etags.chunkUsed) {
- state = YAFFS_BLOCK_STATE_NEEDS_SCANNING;
- seqnum = etags.sequenceNumber;
- }
- else {
- state = YAFFS_BLOCK_STATE_EMPTY;
- }
-
- *pState = state;
- *pSequenceNumber = seqnum;
-
- /* query always succeeds */
- return YAFFS_OK;
-}
-
-#endif /*KERNEL_VERSION*/