diff options
Diffstat (limited to 'fs/yaffs2/yaffs_mtdif1.c')
| -rw-r--r-- | fs/yaffs2/yaffs_mtdif1.c | 330 |
1 files changed, 0 insertions, 330 deletions
diff --git a/fs/yaffs2/yaffs_mtdif1.c b/fs/yaffs2/yaffs_mtdif1.c deleted file mode 100644 index 5108369..0000000 --- a/fs/yaffs2/yaffs_mtdif1.c +++ /dev/null @@ -1,330 +0,0 @@ -/* - * YAFFS: Yet another FFS. A NAND-flash specific file system. - * - * Copyright (C) 2002-2010 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" - -#ifndef CONFIG_YAFFS_9BYTE_TAGS -# define YTAG1_SIZE 8 -#else -# define YTAG1_SIZE 9 -#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. - */ -#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_OOB_AUTO; - ops.len = (data) ? chunk_bytes : 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", - 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_OOB_AUTO; - ops.len = (data) ? chunk_bytes : 0; - ops.ooblen = YTAG1_SIZE; - ops.datbuf = data; - ops.oobbuf = (u8 *) & pt1; - - /* 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); - } -#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((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 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", - 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_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(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_SCANNING; - } else if (etags.chunk_used) { - state = YAFFS_BLOCK_STATE_NEEDS_SCANNING; - seqnum = etags.seq_number; - } else { - state = YAFFS_BLOCK_STATE_EMPTY; - } - - *state_ptr = state; - *seq_ptr = seqnum; - - /* query always succeeds */ - return YAFFS_OK; -} |