diff options
Diffstat (limited to 'fs/yaffs2/yaffs_tagscompat.c')
-rw-r--r-- | fs/yaffs2/yaffs_tagscompat.c | 422 |
1 files changed, 422 insertions, 0 deletions
diff --git a/fs/yaffs2/yaffs_tagscompat.c b/fs/yaffs2/yaffs_tagscompat.c new file mode 100644 index 000000000000..7578075d9ac1 --- /dev/null +++ b/fs/yaffs2/yaffs_tagscompat.c @@ -0,0 +1,422 @@ +/* + * YAFFS: Yet Another Flash File System. 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. + */ + +#include "yaffs_guts.h" +#include "yaffs_tagscompat.h" +#include "yaffs_ecc.h" +#include "yaffs_getblockinfo.h" +#include "yaffs_trace.h" + +static void yaffs_handle_rd_data_error(struct yaffs_dev *dev, int nand_chunk); + + +/********** Tags ECC calculations *********/ + +void yaffs_calc_ecc(const u8 * data, struct yaffs_spare *spare) +{ + yaffs_ecc_cacl(data, spare->ecc1); + yaffs_ecc_cacl(&data[256], spare->ecc2); +} + +void yaffs_calc_tags_ecc(struct yaffs_tags *tags) +{ + /* Calculate an ecc */ + + unsigned char *b = ((union yaffs_tags_union *)tags)->as_bytes; + unsigned i, j; + unsigned ecc = 0; + unsigned bit = 0; + + tags->ecc = 0; + + for (i = 0; i < 8; i++) { + for (j = 1; j & 0xff; j <<= 1) { + bit++; + if (b[i] & j) + ecc ^= bit; + } + } + + tags->ecc = ecc; + +} + +int yaffs_check_tags_ecc(struct yaffs_tags *tags) +{ + unsigned ecc = tags->ecc; + + yaffs_calc_tags_ecc(tags); + + ecc ^= tags->ecc; + + if (ecc && ecc <= 64) { + /* TODO: Handle the failure better. Retire? */ + unsigned char *b = ((union yaffs_tags_union *)tags)->as_bytes; + + ecc--; + + b[ecc / 8] ^= (1 << (ecc & 7)); + + /* Now recvalc the ecc */ + yaffs_calc_tags_ecc(tags); + + return 1; /* recovered error */ + } else if (ecc) { + /* Wierd ecc failure value */ + /* TODO Need to do somethiong here */ + return -1; /* unrecovered error */ + } + + return 0; +} + +/********** Tags **********/ + +static void yaffs_load_tags_to_spare(struct yaffs_spare *spare_ptr, + struct yaffs_tags *tags_ptr) +{ + union yaffs_tags_union *tu = (union yaffs_tags_union *)tags_ptr; + + yaffs_calc_tags_ecc(tags_ptr); + + spare_ptr->tb0 = tu->as_bytes[0]; + spare_ptr->tb1 = tu->as_bytes[1]; + spare_ptr->tb2 = tu->as_bytes[2]; + spare_ptr->tb3 = tu->as_bytes[3]; + spare_ptr->tb4 = tu->as_bytes[4]; + spare_ptr->tb5 = tu->as_bytes[5]; + spare_ptr->tb6 = tu->as_bytes[6]; + spare_ptr->tb7 = tu->as_bytes[7]; +} + +static void yaffs_get_tags_from_spare(struct yaffs_dev *dev, + struct yaffs_spare *spare_ptr, + struct yaffs_tags *tags_ptr) +{ + union yaffs_tags_union *tu = (union yaffs_tags_union *)tags_ptr; + int result; + + tu->as_bytes[0] = spare_ptr->tb0; + tu->as_bytes[1] = spare_ptr->tb1; + tu->as_bytes[2] = spare_ptr->tb2; + tu->as_bytes[3] = spare_ptr->tb3; + tu->as_bytes[4] = spare_ptr->tb4; + tu->as_bytes[5] = spare_ptr->tb5; + tu->as_bytes[6] = spare_ptr->tb6; + tu->as_bytes[7] = spare_ptr->tb7; + + result = yaffs_check_tags_ecc(tags_ptr); + if (result > 0) + dev->n_tags_ecc_fixed++; + else if (result < 0) + dev->n_tags_ecc_unfixed++; +} + +static void yaffs_spare_init(struct yaffs_spare *spare) +{ + memset(spare, 0xFF, sizeof(struct yaffs_spare)); +} + +static int yaffs_wr_nand(struct yaffs_dev *dev, + int nand_chunk, const u8 * data, + struct yaffs_spare *spare) +{ + if (nand_chunk < dev->param.start_block * dev->param.chunks_per_block) { + yaffs_trace(YAFFS_TRACE_ERROR, + "**>> yaffs chunk %d is not valid", + nand_chunk); + return YAFFS_FAIL; + } + + return dev->param.write_chunk_fn(dev, nand_chunk, data, spare); +} + +static int yaffs_rd_chunk_nand(struct yaffs_dev *dev, + int nand_chunk, + u8 * data, + struct yaffs_spare *spare, + enum yaffs_ecc_result *ecc_result, + int correct_errors) +{ + int ret_val; + struct yaffs_spare local_spare; + + if (!spare && data) { + /* If we don't have a real spare, then we use a local one. */ + /* Need this for the calculation of the ecc */ + spare = &local_spare; + } + + if (!dev->param.use_nand_ecc) { + ret_val = + dev->param.read_chunk_fn(dev, nand_chunk, data, spare); + if (data && correct_errors) { + /* Do ECC correction */ + /* Todo handle any errors */ + int ecc_result1, ecc_result2; + u8 calc_ecc[3]; + + yaffs_ecc_cacl(data, calc_ecc); + ecc_result1 = + yaffs_ecc_correct(data, spare->ecc1, calc_ecc); + yaffs_ecc_cacl(&data[256], calc_ecc); + ecc_result2 = + yaffs_ecc_correct(&data[256], spare->ecc2, + calc_ecc); + + if (ecc_result1 > 0) { + yaffs_trace(YAFFS_TRACE_ERROR, + "**>>yaffs ecc error fix performed on chunk %d:0", + nand_chunk); + dev->n_ecc_fixed++; + } else if (ecc_result1 < 0) { + yaffs_trace(YAFFS_TRACE_ERROR, + "**>>yaffs ecc error unfixed on chunk %d:0", + nand_chunk); + dev->n_ecc_unfixed++; + } + + if (ecc_result2 > 0) { + yaffs_trace(YAFFS_TRACE_ERROR, + "**>>yaffs ecc error fix performed on chunk %d:1", + nand_chunk); + dev->n_ecc_fixed++; + } else if (ecc_result2 < 0) { + yaffs_trace(YAFFS_TRACE_ERROR, + "**>>yaffs ecc error unfixed on chunk %d:1", + nand_chunk); + dev->n_ecc_unfixed++; + } + + if (ecc_result1 || ecc_result2) { + /* We had a data problem on this page */ + yaffs_handle_rd_data_error(dev, nand_chunk); + } + + if (ecc_result1 < 0 || ecc_result2 < 0) + *ecc_result = YAFFS_ECC_RESULT_UNFIXED; + else if (ecc_result1 > 0 || ecc_result2 > 0) + *ecc_result = YAFFS_ECC_RESULT_FIXED; + else + *ecc_result = YAFFS_ECC_RESULT_NO_ERROR; + } + } else { + /* Must allocate enough memory for spare+2*sizeof(int) */ + /* for ecc results from device. */ + struct yaffs_nand_spare nspare; + + memset(&nspare, 0, sizeof(nspare)); + + ret_val = dev->param.read_chunk_fn(dev, nand_chunk, data, + (struct yaffs_spare *) + &nspare); + memcpy(spare, &nspare, sizeof(struct yaffs_spare)); + if (data && correct_errors) { + if (nspare.eccres1 > 0) { + yaffs_trace(YAFFS_TRACE_ERROR, + "**>>mtd ecc error fix performed on chunk %d:0", + nand_chunk); + } else if (nspare.eccres1 < 0) { + yaffs_trace(YAFFS_TRACE_ERROR, + "**>>mtd ecc error unfixed on chunk %d:0", + nand_chunk); + } + + if (nspare.eccres2 > 0) { + yaffs_trace(YAFFS_TRACE_ERROR, + "**>>mtd ecc error fix performed on chunk %d:1", + nand_chunk); + } else if (nspare.eccres2 < 0) { + yaffs_trace(YAFFS_TRACE_ERROR, + "**>>mtd ecc error unfixed on chunk %d:1", + nand_chunk); + } + + if (nspare.eccres1 || nspare.eccres2) { + /* We had a data problem on this page */ + yaffs_handle_rd_data_error(dev, nand_chunk); + } + + if (nspare.eccres1 < 0 || nspare.eccres2 < 0) + *ecc_result = YAFFS_ECC_RESULT_UNFIXED; + else if (nspare.eccres1 > 0 || nspare.eccres2 > 0) + *ecc_result = YAFFS_ECC_RESULT_FIXED; + else + *ecc_result = YAFFS_ECC_RESULT_NO_ERROR; + + } + } + return ret_val; +} + +/* + * Functions for robustisizing + */ + +static void yaffs_handle_rd_data_error(struct yaffs_dev *dev, int nand_chunk) +{ + int flash_block = nand_chunk / dev->param.chunks_per_block; + + /* Mark the block for retirement */ + yaffs_get_block_info(dev, + flash_block + dev->block_offset)->needs_retiring = + 1; + yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS, + "**>>Block %d marked for retirement", + flash_block); + + /* TODO: + * Just do a garbage collection on the affected block + * then retire the block + * NB recursion + */ +} + +int yaffs_tags_compat_wr(struct yaffs_dev *dev, + int nand_chunk, + const u8 * data, const struct yaffs_ext_tags *ext_tags) +{ + struct yaffs_spare spare; + struct yaffs_tags tags; + + yaffs_spare_init(&spare); + + if (ext_tags->is_deleted) + spare.page_status = 0; + else { + tags.obj_id = ext_tags->obj_id; + tags.chunk_id = ext_tags->chunk_id; + + tags.n_bytes_lsb = ext_tags->n_bytes & 0x3ff; + + if (dev->data_bytes_per_chunk >= 1024) + tags.n_bytes_msb = (ext_tags->n_bytes >> 10) & 3; + else + tags.n_bytes_msb = 3; + + tags.serial_number = ext_tags->serial_number; + + if (!dev->param.use_nand_ecc && data) + yaffs_calc_ecc(data, &spare); + + yaffs_load_tags_to_spare(&spare, &tags); + + } + + return yaffs_wr_nand(dev, nand_chunk, data, &spare); +} + +int yaffs_tags_compat_rd(struct yaffs_dev *dev, + int nand_chunk, + u8 * data, struct yaffs_ext_tags *ext_tags) +{ + + struct yaffs_spare spare; + struct yaffs_tags tags; + enum yaffs_ecc_result ecc_result = YAFFS_ECC_RESULT_UNKNOWN; + + static struct yaffs_spare spare_ff; + static int init; + + if (!init) { + memset(&spare_ff, 0xFF, sizeof(spare_ff)); + init = 1; + } + + if (yaffs_rd_chunk_nand(dev, nand_chunk, data, &spare, &ecc_result, 1)) { + /* ext_tags may be NULL */ + if (ext_tags) { + + int deleted = + (hweight8(spare.page_status) < 7) ? 1 : 0; + + ext_tags->is_deleted = deleted; + ext_tags->ecc_result = ecc_result; + ext_tags->block_bad = 0; /* We're reading it */ + /* therefore it is not a bad block */ + ext_tags->chunk_used = + (memcmp(&spare_ff, &spare, sizeof(spare_ff)) != + 0) ? 1 : 0; + + if (ext_tags->chunk_used) { + yaffs_get_tags_from_spare(dev, &spare, &tags); + + ext_tags->obj_id = tags.obj_id; + ext_tags->chunk_id = tags.chunk_id; + ext_tags->n_bytes = tags.n_bytes_lsb; + + if (dev->data_bytes_per_chunk >= 1024) + ext_tags->n_bytes |= + (((unsigned)tags. + n_bytes_msb) << 10); + + ext_tags->serial_number = tags.serial_number; + } + } + + return YAFFS_OK; + } else { + return YAFFS_FAIL; + } +} + +int yaffs_tags_compat_mark_bad(struct yaffs_dev *dev, int flash_block) +{ + + struct yaffs_spare spare; + + memset(&spare, 0xff, sizeof(struct yaffs_spare)); + + spare.block_status = 'Y'; + + yaffs_wr_nand(dev, flash_block * dev->param.chunks_per_block, NULL, + &spare); + yaffs_wr_nand(dev, flash_block * dev->param.chunks_per_block + 1, + NULL, &spare); + + return YAFFS_OK; + +} + +int yaffs_tags_compat_query_block(struct yaffs_dev *dev, + int block_no, + enum yaffs_block_state *state, + u32 * seq_number) +{ + + struct yaffs_spare spare0, spare1; + static struct yaffs_spare spare_ff; + static int init; + enum yaffs_ecc_result dummy; + + if (!init) { + memset(&spare_ff, 0xFF, sizeof(spare_ff)); + init = 1; + } + + *seq_number = 0; + + yaffs_rd_chunk_nand(dev, block_no * dev->param.chunks_per_block, NULL, + &spare0, &dummy, 1); + yaffs_rd_chunk_nand(dev, block_no * dev->param.chunks_per_block + 1, + NULL, &spare1, &dummy, 1); + + if (hweight8(spare0.block_status & spare1.block_status) < 7) + *state = YAFFS_BLOCK_STATE_DEAD; + else if (memcmp(&spare_ff, &spare0, sizeof(spare_ff)) == 0) + *state = YAFFS_BLOCK_STATE_EMPTY; + else + *state = YAFFS_BLOCK_STATE_NEEDS_SCANNING; + + return YAFFS_OK; +} |