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authorSrikant Patnaik2015-01-11 12:28:04 +0530
committerSrikant Patnaik2015-01-11 12:28:04 +0530
commit871480933a1c28f8a9fed4c4d34d06c439a7a422 (patch)
tree8718f573808810c2a1e8cb8fb6ac469093ca2784 /fs/yaffs2/yaffs_mtdif1.c
parent9d40ac5867b9aefe0722bc1f110b965ff294d30d (diff)
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Moved, renamed, and deleted files
The original directory structure was scattered and unorganized. Changes are basically to make it look like kernel structure.
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+/*
+ * 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 */