+++ /dev/null
-/*
- * YAFFS: Yet another FFS. A NAND-flash specific file system.
- *
- * Copyright (C) 2002-2011 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.
- */
-
-/*
- * 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_tags compatability 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 (use_nand_ecc is true).
- */
-
-#include "yportenv.h"
-#include "yaffs_trace.h"
-#include "yaffs_guts.h"
-#include "yaffs_packedtags1.h"
-#include "yaffs_tagscompat.h" /* for yaffs_calc_tags_ecc */
-#include "yaffs_linux.h"
-
-#include "linux/kernel.h"
-#include "linux/version.h"
-#include "linux/types.h"
-#include "linux/mtd/mtd.h"
-
-#if (LINUX_VERSION_CODE < KERNEL_VERSION(3, 2, 0))
-#define MTD_OPS_AUTO_OOB MTD_OOB_AUTO
-#endif
-
-
-/* Don't compile this module if we don't have MTD's mtd_oob_ops interface */
-#if (MTD_VERSION_CODE > MTD_VERSION(2, 6, 17))
-
-
-#if 0
-/* Use the following nand_ecclayout with MTD when using
- * 9 byte 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
- * page_status 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 packed_tags1 plus page_status: T0,T1,T2,T3,T4,T5,T6,T7,P
- * where Tn are the tag bytes, En are MTD's ECC bytes, P is the page_status
- * 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 packed_tags1 form
- * - Compute mini-ECC for packed_tags1
- * - Write data and packed tags to NAND.
- *
- * Note: Due to the use of the packed_tags1 meta-data which does not include
- * a full sequence number (as found in the larger packed_tags2 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_write_chunk_tags(struct yaffs_dev *dev,
- int nand_chunk, const u8 *data,
- const struct yaffs_ext_tags *etags)
-{
- struct mtd_info *mtd = yaffs_dev_to_mtd(dev);
- int chunk_bytes = dev->data_bytes_per_chunk;
- loff_t addr = ((loff_t) nand_chunk) * chunk_bytes;
- struct mtd_oob_ops ops;
- struct yaffs_packed_tags1 pt1;
- int retval;
-
- /* we assume that packed_tags1 and struct yaffs_tags are compatible */
- compile_time_assertion(sizeof(struct yaffs_packed_tags1) == 12);
- compile_time_assertion(sizeof(struct yaffs_tags) == 8);
-
- yaffs_pack_tags1(&pt1, etags);
- yaffs_calc_tags_ecc((struct yaffs_tags *)&pt1);
-
- /* When deleting a chunk, the upper layer provides only skeletal
- * etags, one with is_deleted 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.
- */
- if(dev->param.tags_9bytes) {
- ((u8 *) &pt1)[8] = 0xff;
- if (etags->is_deleted) {
- memset(&pt1, 0xff, 8);
- /* zero page_status byte to indicate deleted */
- ((u8 *) &pt1)[8] = 0;
- }
- } else {
- if (etags->is_deleted) {
- memset(&pt1, 0xff, 8);
- /* clear delete status bit to indicate deleted */
- pt1.deleted = 0;
- }
- }
-
- memset(&ops, 0, sizeof(ops));
- ops.mode = MTD_OPS_AUTO_OOB;
- ops.len = (data) ? chunk_bytes : 0;
- ops.ooblen = dev->param.tags_9bytes ? 9 : 8;
- 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",
- nand_chunk, retval);
- }
- return retval ? YAFFS_FAIL : YAFFS_OK;
-}
-
-/* Return with empty ExtendedTags but add ecc_result.
- */
-static int rettags(struct yaffs_ext_tags *etags, int ecc_result, int retval)
-{
- if (etags) {
- memset(etags, 0, sizeof(*etags));
- etags->ecc_result = ecc_result;
- }
- return retval;
-}
-
-/* Read a chunk (page) from NAND.
- *
- * Caller expects ExtendedTags data to be usable even on error; that is,
- * all members except ecc_result and block_bad are zeroed.
- *
- * - Check ECC results for data (if applicable)
- * - Check for blank/erased block (return empty ExtendedTags if blank)
- * - Check the packed_tags1 mini-ECC (correct if necessary/possible)
- * - Convert packed_tags1 to ExtendedTags
- * - Update ecc_result and block_bad members to refect state.
- *
- * Returns YAFFS_OK or YAFFS_FAIL.
- */
-int nandmtd1_read_chunk_tags(struct yaffs_dev *dev,
- int nand_chunk, u8 *data,
- struct yaffs_ext_tags *etags)
-{
- struct mtd_info *mtd = yaffs_dev_to_mtd(dev);
- int chunk_bytes = dev->data_bytes_per_chunk;
- loff_t addr = ((loff_t) nand_chunk) * chunk_bytes;
- int eccres = YAFFS_ECC_RESULT_NO_ERROR;
- struct mtd_oob_ops ops;
- struct yaffs_packed_tags1 pt1;
- int retval;
- int deleted;
-
- memset(&ops, 0, sizeof(ops));
- ops.mode = MTD_OPS_AUTO_OOB;
- ops.len = (data) ? chunk_bytes : 0;
- ops.ooblen = dev->param.tags_9bytes ? 9 : 8;
- 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)
- yaffs_trace(YAFFS_TRACE_MTD,
- "read_oob failed, chunk %d, mtd error %d",
- nand_chunk, retval);
-
- switch (retval) {
- case 0:
- /* no error */
- break;
-
- case -EUCLEAN:
- /* MTD's ECC fixed the data */
- eccres = YAFFS_ECC_RESULT_FIXED;
- dev->n_ecc_fixed++;
- break;
-
- case -EBADMSG:
- /* MTD's ECC could not fix the data */
- dev->n_ecc_unfixed++;
- /* fall into... */
- default:
- rettags(etags, YAFFS_ECC_RESULT_UNFIXED, 0);
- etags->block_bad = (mtd->block_isbad) (mtd, addr);
- return YAFFS_FAIL;
- }
-
- /* Check for a blank/erased chunk.
- */
- if (yaffs_check_ff((u8 *) &pt1, 8)) {
- /* when blank, upper layers want ecc_result to be <= NO_ERROR */
- return rettags(etags, YAFFS_ECC_RESULT_NO_ERROR, YAFFS_OK);
- }
-
- if(dev->param.tags_9bytes) {
- deleted = (hweight8(((u8 *) &pt1)[8]) < 7);
- } else {
- /* 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;
- }
-
- /* Check the packed tags mini-ECC and correct if necessary/possible.
- */
- retval = yaffs_check_tags_ecc((struct yaffs_tags *)&pt1);
- switch (retval) {
- case 0:
- /* no tags error, use MTD result */
- break;
- case 1:
- /* recovered tags-ECC error */
- dev->n_tags_ecc_fixed++;
- if (eccres == YAFFS_ECC_RESULT_NO_ERROR)
- eccres = YAFFS_ECC_RESULT_FIXED;
- break;
- default:
- /* unrecovered tags-ECC error */
- dev->n_tags_ecc_unfixed++;
- return rettags(etags, YAFFS_ECC_RESULT_UNFIXED, YAFFS_FAIL);
- }
-
- /* Unpack the tags to extended form and set ECC result.
- * [set should_be_ff just to keep yaffs_unpack_tags1 happy]
- */
- pt1.should_be_ff = 0xffffffff;
- yaffs_unpack_tags1(etags, &pt1);
- etags->ecc_result = eccres;
-
- /* Set deleted state */
- etags->is_deleted = 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_mark_block_bad(struct yaffs_dev *dev, int block_no)
-{
- struct mtd_info *mtd = yaffs_dev_to_mtd(dev);
- int blocksize = dev->param.chunks_per_block * dev->data_bytes_per_chunk;
- int retval;
-
- yaffs_trace(YAFFS_TRACE_BAD_BLOCKS, "marking block %d bad", block_no);
-
- retval = mtd->block_markbad(mtd, (loff_t) blocksize * block_no);
- return (retval) ? YAFFS_FAIL : YAFFS_OK;
-}
-
-/* Check any MTD prerequists.
- *
- * Returns YAFFS_OK or YAFFS_FAIL.
- */
-static int nandmtd1_test_prerequists(struct yaffs_dev *dev, 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 < (dev->param.tags_9bytes ? 9 : 8)) {
- yaffs_trace(YAFFS_TRACE_ERROR,
- "mtd device has only %d bytes for tags, need %d",
- oobavail, dev->param.tags_9bytes ? 9 : 8);
- 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_SCAN, the block is in use
- * - YAFFS_BLOCK_STATE_EMPTY, the block is clean
- *
- * Always returns YAFFS_OK.
- */
-int nandmtd1_query_block(struct yaffs_dev *dev, int block_no,
- enum yaffs_block_state *state_ptr, u32 * seq_ptr)
-{
- struct mtd_info *mtd = yaffs_dev_to_mtd(dev);
- int chunk_num = block_no * dev->param.chunks_per_block;
- loff_t addr = (loff_t) chunk_num * dev->data_bytes_per_chunk;
- struct yaffs_ext_tags 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_test_prerequists(dev, mtd) != YAFFS_OK)
- return YAFFS_FAIL;
-
- retval = nandmtd1_read_chunk_tags(dev, chunk_num, NULL, &etags);
- etags.block_bad = (mtd->block_isbad) (mtd, addr);
- if (etags.block_bad) {
- yaffs_trace(YAFFS_TRACE_BAD_BLOCKS,
- "block %d is marked bad",
- block_no);
- state = YAFFS_BLOCK_STATE_DEAD;
- } else if (etags.ecc_result != YAFFS_ECC_RESULT_NO_ERROR) {
- /* bad tags, need to look more closely */
- state = YAFFS_BLOCK_STATE_NEEDS_SCAN;
- } else if (etags.chunk_used) {
- state = YAFFS_BLOCK_STATE_NEEDS_SCAN;
- seqnum = etags.seq_number;
- } else {
- state = YAFFS_BLOCK_STATE_EMPTY;
- }
-
- *state_ptr = state;
- *seq_ptr = seqnum;
-
- /* query always succeeds */
- return YAFFS_OK;
-}
-
-#endif /*MTD_VERSION */
projects / yaffs2.git / blobdiff