| /* |
| * YAFFS: Yet another FFS. A NAND-flash specific file system. |
| * yaffs_mtdif1.c NAND mtd interface functions for small-page NAND. |
| * |
| * Copyright (C) 2002-2010 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_tags_tCompatability 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" |
| #include "mtd/mtd-abi.h" |
| |
| /* 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)) |
| |
| #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 |
| * 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 PackedTags1 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 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_dev_t *dev, |
| int nand_chunk, const __u8 *data, const yaffs_ext_tags *etags) |
| { |
| struct mtd_info *mtd = yaffs_dev_to_mtd(dev); |
| int chunkBytes = dev->data_bytes_per_chunk; |
| loff_t addr = ((loff_t)nand_chunk) * chunkBytes; |
| struct mtd_oob_ops ops; |
| yaffs_PackedTags1 pt1; |
| int retval; |
| |
| /* we assume that PackedTags1 and yaffs_tags_t are compatible */ |
| compile_time_assertion(sizeof(yaffs_PackedTags1) == 12); |
| compile_time_assertion(sizeof(yaffs_tags_t) == 8); |
| |
| yaffs_PackTags1(&pt1, etags); |
| yaffs_calc_tags_ecc((yaffs_tags_t *)&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. |
| */ |
| #ifndef CONFIG_YAFFS_9BYTE_TAGS |
| if (etags->is_deleted) { |
| memset(&pt1, 0xff, 8); |
| /* clear delete status bit to indicate deleted */ |
| pt1.deleted = 0; |
| } |
| #else |
| ((__u8 *)&pt1)[8] = 0xff; |
| if (etags->is_deleted) { |
| memset(&pt1, 0xff, 8); |
| /* zero page_status byte to indicate deleted */ |
| ((__u8 *)&pt1)[8] = 0; |
| } |
| #endif |
| |
| memset(&ops, 0, sizeof(ops)); |
| ops.mode = MTD_OPS_AUTO_OOB; |
| 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) { |
| T(YAFFS_TRACE_MTD, |
| (TSTR("write_oob failed, chunk %d, mtd error %d"TENDSTR), |
| nand_chunk, retval)); |
| } |
| return retval ? YAFFS_FAIL : YAFFS_OK; |
| } |
| |
| /* Return with empty ExtendedTags but add ecc_result. |
| */ |
| static int rettags(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 PackedTags1 mini-ECC (correct if necessary/possible) |
| * - Convert PackedTags1 to ExtendedTags |
| * - Update ecc_result and block_bad members to refect state. |
| * |
| * Returns YAFFS_OK or YAFFS_FAIL. |
| */ |
| int nandmtd1_ReadChunkWithTagsFromNAND(yaffs_dev_t *dev, |
| int nand_chunk, __u8 *data, yaffs_ext_tags *etags) |
| { |
| struct mtd_info *mtd = yaffs_dev_to_mtd(dev); |
| int chunkBytes = dev->data_bytes_per_chunk; |
| loff_t addr = ((loff_t)nand_chunk) * 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_OPS_AUTO_OOB; |
| 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), |
| 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); |
| } |
| |
| #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_count_bits(((__u8 *)&pt1)[8]) < 7); |
| #endif |
| |
| /* Check the packed tags mini-ECC and correct if necessary/possible. |
| */ |
| retval = yaffs_check_tags_ecc((yaffs_tags_t *)&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 shouldBeFF just to keep yaffs_unpack_tags1 happy] |
| */ |
| pt1.shouldBeFF = 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_MarkNANDBlockBad(struct yaffs_dev_s *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; |
| |
| T(YAFFS_TRACE_BAD_BLOCKS,(TSTR("marking block %d bad"TENDSTR), 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_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) { |
| T(YAFFS_TRACE_ERROR, |
| (TSTR("mtd device has only %d bytes for tags, need %d"TENDSTR), |
| 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_dev_s *dev, int block_no, |
| yaffs_block_state_t *pState, __u32 *pSequenceNumber) |
| { |
| struct mtd_info *mtd = yaffs_dev_to_mtd(dev); |
| int chunkNo = block_no * dev->param.chunks_per_block; |
| loff_t addr = (loff_t)chunkNo * dev->data_bytes_per_chunk; |
| 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_TestPrerequists(mtd) != YAFFS_OK) |
| return YAFFS_FAIL; |
| |
| retval = nandmtd1_ReadChunkWithTagsFromNAND(dev, chunkNo, NULL, &etags); |
| etags.block_bad = (mtd->block_isbad)(mtd, addr); |
| if (etags.block_bad) { |
| T(YAFFS_TRACE_BAD_BLOCKS, |
| (TSTR("block %d is marked bad"TENDSTR), 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_SCANNING; |
| } else if (etags.chunk_used) { |
| state = YAFFS_BLOCK_STATE_NEEDS_SCANNING; |
| seqnum = etags.seq_number; |
| } else { |
| state = YAFFS_BLOCK_STATE_EMPTY; |
| } |
| |
| *pState = state; |
| *pSequenceNumber = seqnum; |
| |
| /* query always succeeds */ |
| return YAFFS_OK; |
| } |
| |
| #endif /*MTD_VERSION*/ |