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- /*
- * YAFFS: Yet Another Flash File System. 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.
- */
- #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_calc(data, spare->ecc1);
- yaffs_ecc_calc(&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) {
- /* 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_calc(data, calc_ecc);
- ecc_result1 =
- yaffs_ecc_correct(data, spare->ecc1, calc_ecc);
- yaffs_ecc_calc(&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 & (1024 - 1);
- 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;
- int deleted;
- if (!init) {
- memset(&spare_ff, 0xff, sizeof(spare_ff));
- init = 1;
- }
- if (!yaffs_rd_chunk_nand(dev, nand_chunk,
- data, &spare, &ecc_result, 1))
- return YAFFS_FAIL;
- /* ext_tags may be NULL */
- if (!ext_tags)
- return YAFFS_OK;
- 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)) ? 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;
- }
- 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_SCAN;
- return YAFFS_OK;
- }
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