nand: Merge BCH code from Linux nand driver
[backport from linux commit 02f8c6aee8df3cdc935e9bdd4f2d020306035dbe] This patch merges the BCH ECC algorithm from the 3.0 Linux kernel. This enables U-Boot to support modern NAND flash chips that require more than 1-bit of ECC in software. Signed-off-by: Christian Hitz <christian.hitz@aizo.com> Cc: Scott Wood <scottwood@freescale.com> Signed-off-by: Scott Wood <scottwood@freescale.com>
This commit is contained in:
Christian Hitz
Scott Wood
parent
4d2aee2b36
commit
4c6de8560c
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@ -41,6 +41,7 @@ COBJS-y += nand_util.o
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endif
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COBJS-y += nand_ecc.o
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COBJS-y += nand_base.o
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COBJS-$(CONFIG_NAND_ECC_BCH) += nand_bch.o
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COBJS-$(CONFIG_NAND_ATMEL) += atmel_nand.o
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COBJS-$(CONFIG_DRIVER_NAND_BFIN) += bfin_nand.o
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@ -43,6 +43,7 @@
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#include <linux/mtd/mtd.h>
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#include <linux/mtd/nand.h>
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#include <linux/mtd/nand_ecc.h>
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#include <linux/mtd/nand_bch.h>
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#ifdef CONFIG_MTD_PARTITIONS
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#include <linux/mtd/partitions.h>
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@ -2763,7 +2764,7 @@ int nand_scan_tail(struct mtd_info *mtd)
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/*
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* If no default placement scheme is given, select an appropriate one
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*/
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if (!chip->ecc.layout) {
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if (!chip->ecc.layout && (chip->ecc.mode != NAND_ECC_SOFT_BCH)) {
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switch (mtd->oobsize) {
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case 8:
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chip->ecc.layout = &nand_oob_8;
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@ -2864,6 +2865,39 @@ int nand_scan_tail(struct mtd_info *mtd)
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chip->ecc.bytes = 3;
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break;
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case NAND_ECC_SOFT_BCH:
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if (!mtd_nand_has_bch()) {
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printk(KERN_WARNING "CONFIG_MTD_ECC_BCH not enabled\n");
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return -EINVAL;
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}
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chip->ecc.calculate = nand_bch_calculate_ecc;
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chip->ecc.correct = nand_bch_correct_data;
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chip->ecc.read_page = nand_read_page_swecc;
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chip->ecc.read_subpage = nand_read_subpage;
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chip->ecc.write_page = nand_write_page_swecc;
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chip->ecc.read_page_raw = nand_read_page_raw;
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chip->ecc.write_page_raw = nand_write_page_raw;
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chip->ecc.read_oob = nand_read_oob_std;
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chip->ecc.write_oob = nand_write_oob_std;
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/*
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* Board driver should supply ecc.size and ecc.bytes values to
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* select how many bits are correctable; see nand_bch_init()
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* for details.
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* Otherwise, default to 4 bits for large page devices
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*/
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if (!chip->ecc.size && (mtd->oobsize >= 64)) {
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chip->ecc.size = 512;
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chip->ecc.bytes = 7;
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}
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chip->ecc.priv = nand_bch_init(mtd,
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chip->ecc.size,
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chip->ecc.bytes,
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&chip->ecc.layout);
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if (!chip->ecc.priv)
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printk(KERN_WARNING "BCH ECC initialization failed!\n");
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break;
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case NAND_ECC_NONE:
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printk(KERN_WARNING "NAND_ECC_NONE selected by board driver. "
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"This is not recommended !!\n");
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@ -2989,6 +3023,9 @@ void nand_release(struct mtd_info *mtd)
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{
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struct nand_chip *chip = mtd->priv;
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if (chip->ecc.mode == NAND_ECC_SOFT_BCH)
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nand_bch_free((struct nand_bch_control *)chip->ecc.priv);
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#ifdef CONFIG_MTD_PARTITIONS
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/* Deregister partitions */
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del_mtd_partitions(mtd);
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@ -0,0 +1,236 @@
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/*
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* This file provides ECC correction for more than 1 bit per block of data,
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* using binary BCH codes. It relies on the generic BCH library lib/bch.c.
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*
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* Copyright © 2011 Ivan Djelic <ivan.djelic@parrot.com>
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*
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* This file is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2 or (at your option) any
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* later version.
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*
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* This file is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this file; if not, write to the Free Software Foundation, Inc.,
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* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
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*/
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#include <common.h>
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/*#include <asm/io.h>*/
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#include <linux/types.h>
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#include <linux/bitops.h>
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#include <linux/mtd/mtd.h>
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#include <linux/mtd/nand.h>
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#include <linux/mtd/nand_bch.h>
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#include <linux/bch.h>
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#include <malloc.h>
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/**
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* struct nand_bch_control - private NAND BCH control structure
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* @bch: BCH control structure
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* @ecclayout: private ecc layout for this BCH configuration
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* @errloc: error location array
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* @eccmask: XOR ecc mask, allows erased pages to be decoded as valid
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*/
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struct nand_bch_control {
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struct bch_control *bch;
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struct nand_ecclayout ecclayout;
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unsigned int *errloc;
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unsigned char *eccmask;
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};
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/**
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* nand_bch_calculate_ecc - [NAND Interface] Calculate ECC for data block
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* @mtd: MTD block structure
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* @buf: input buffer with raw data
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* @code: output buffer with ECC
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*/
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int nand_bch_calculate_ecc(struct mtd_info *mtd, const unsigned char *buf,
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unsigned char *code)
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{
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const struct nand_chip *chip = mtd->priv;
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struct nand_bch_control *nbc = chip->ecc.priv;
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unsigned int i;
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memset(code, 0, chip->ecc.bytes);
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encode_bch(nbc->bch, buf, chip->ecc.size, code);
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/* apply mask so that an erased page is a valid codeword */
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for (i = 0; i < chip->ecc.bytes; i++)
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code[i] ^= nbc->eccmask[i];
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return 0;
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}
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/**
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* nand_bch_correct_data - [NAND Interface] Detect and correct bit error(s)
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* @mtd: MTD block structure
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* @buf: raw data read from the chip
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* @read_ecc: ECC from the chip
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* @calc_ecc: the ECC calculated from raw data
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*
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* Detect and correct bit errors for a data byte block
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*/
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int nand_bch_correct_data(struct mtd_info *mtd, unsigned char *buf,
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unsigned char *read_ecc, unsigned char *calc_ecc)
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{
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const struct nand_chip *chip = mtd->priv;
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struct nand_bch_control *nbc = chip->ecc.priv;
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unsigned int *errloc = nbc->errloc;
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int i, count;
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count = decode_bch(nbc->bch, NULL, chip->ecc.size, read_ecc, calc_ecc,
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NULL, errloc);
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if (count > 0) {
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for (i = 0; i < count; i++) {
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if (errloc[i] < (chip->ecc.size*8))
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/* error is located in data, correct it */
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buf[errloc[i] >> 3] ^= (1 << (errloc[i] & 7));
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/* else error in ecc, no action needed */
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MTDDEBUG(MTD_DEBUG_LEVEL0, "%s: corrected bitflip %u\n",
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__func__, errloc[i]);
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}
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} else if (count < 0) {
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printk(KERN_ERR "ecc unrecoverable error\n");
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count = -1;
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}
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return count;
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}
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/**
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* nand_bch_init - [NAND Interface] Initialize NAND BCH error correction
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* @mtd: MTD block structure
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* @eccsize: ecc block size in bytes
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* @eccbytes: ecc length in bytes
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* @ecclayout: output default layout
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*
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* Returns:
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* a pointer to a new NAND BCH control structure, or NULL upon failure
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*
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* Initialize NAND BCH error correction. Parameters @eccsize and @eccbytes
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* are used to compute BCH parameters m (Galois field order) and t (error
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* correction capability). @eccbytes should be equal to the number of bytes
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* required to store m*t bits, where m is such that 2^m-1 > @eccsize*8.
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*
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* Example: to configure 4 bit correction per 512 bytes, you should pass
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* @eccsize = 512 (thus, m=13 is the smallest integer such that 2^m-1 > 512*8)
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* @eccbytes = 7 (7 bytes are required to store m*t = 13*4 = 52 bits)
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*/
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struct nand_bch_control *
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nand_bch_init(struct mtd_info *mtd, unsigned int eccsize, unsigned int eccbytes,
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struct nand_ecclayout **ecclayout)
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{
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unsigned int m, t, eccsteps, i;
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struct nand_ecclayout *layout;
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struct nand_bch_control *nbc = NULL;
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unsigned char *erased_page;
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if (!eccsize || !eccbytes) {
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printk(KERN_WARNING "ecc parameters not supplied\n");
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goto fail;
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}
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m = fls(1+8*eccsize);
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t = (eccbytes*8)/m;
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nbc = kzalloc(sizeof(*nbc), GFP_KERNEL);
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if (!nbc)
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goto fail;
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nbc->bch = init_bch(m, t, 0);
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if (!nbc->bch)
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goto fail;
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/* verify that eccbytes has the expected value */
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if (nbc->bch->ecc_bytes != eccbytes) {
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printk(KERN_WARNING "invalid eccbytes %u, should be %u\n",
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eccbytes, nbc->bch->ecc_bytes);
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goto fail;
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}
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eccsteps = mtd->writesize/eccsize;
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/* if no ecc placement scheme was provided, build one */
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if (!*ecclayout) {
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/* handle large page devices only */
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if (mtd->oobsize < 64) {
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printk(KERN_WARNING "must provide an oob scheme for "
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"oobsize %d\n", mtd->oobsize);
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goto fail;
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}
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layout = &nbc->ecclayout;
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layout->eccbytes = eccsteps*eccbytes;
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/* reserve 2 bytes for bad block marker */
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if (layout->eccbytes+2 > mtd->oobsize) {
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printk(KERN_WARNING "no suitable oob scheme available "
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"for oobsize %d eccbytes %u\n", mtd->oobsize,
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eccbytes);
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goto fail;
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}
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/* put ecc bytes at oob tail */
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for (i = 0; i < layout->eccbytes; i++)
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layout->eccpos[i] = mtd->oobsize-layout->eccbytes+i;
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layout->oobfree[0].offset = 2;
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layout->oobfree[0].length = mtd->oobsize-2-layout->eccbytes;
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*ecclayout = layout;
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}
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/* sanity checks */
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if (8*(eccsize+eccbytes) >= (1 << m)) {
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printk(KERN_WARNING "eccsize %u is too large\n", eccsize);
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goto fail;
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}
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if ((*ecclayout)->eccbytes != (eccsteps*eccbytes)) {
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printk(KERN_WARNING "invalid ecc layout\n");
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goto fail;
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}
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nbc->eccmask = kmalloc(eccbytes, GFP_KERNEL);
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nbc->errloc = kmalloc(t*sizeof(*nbc->errloc), GFP_KERNEL);
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if (!nbc->eccmask || !nbc->errloc)
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goto fail;
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/*
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* compute and store the inverted ecc of an erased ecc block
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*/
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erased_page = kmalloc(eccsize, GFP_KERNEL);
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if (!erased_page)
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goto fail;
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memset(erased_page, 0xff, eccsize);
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memset(nbc->eccmask, 0, eccbytes);
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encode_bch(nbc->bch, erased_page, eccsize, nbc->eccmask);
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kfree(erased_page);
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for (i = 0; i < eccbytes; i++)
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nbc->eccmask[i] ^= 0xff;
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return nbc;
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fail:
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nand_bch_free(nbc);
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return NULL;
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}
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/**
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* nand_bch_free - [NAND Interface] Release NAND BCH ECC resources
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* @nbc: NAND BCH control structure
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*/
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void nand_bch_free(struct nand_bch_control *nbc)
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{
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if (nbc) {
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free_bch(nbc->bch);
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kfree(nbc->errloc);
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kfree(nbc->eccmask);
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kfree(nbc);
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}
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}
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@ -0,0 +1,79 @@
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/*
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* Generic binary BCH encoding/decoding library
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as published by
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* the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*
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* You should have received a copy of the GNU General Public License along with
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* this program; if not, write to the Free Software Foundation, Inc., 51
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* Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Copyright © 2011 Parrot S.A.
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*
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* Author: Ivan Djelic <ivan.djelic@parrot.com>
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*
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* Description:
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*
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* This library provides runtime configurable encoding/decoding of binary
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* Bose-Chaudhuri-Hocquenghem (BCH) codes.
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*/
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#ifndef _BCH_H
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#define _BCH_H
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#include <linux/types.h>
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/**
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* struct bch_control - BCH control structure
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* @m: Galois field order
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* @n: maximum codeword size in bits (= 2^m-1)
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* @t: error correction capability in bits
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* @ecc_bits: ecc exact size in bits, i.e. generator polynomial degree (<=m*t)
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* @ecc_bytes: ecc max size (m*t bits) in bytes
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* @a_pow_tab: Galois field GF(2^m) exponentiation lookup table
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* @a_log_tab: Galois field GF(2^m) log lookup table
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* @mod8_tab: remainder generator polynomial lookup tables
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* @ecc_buf: ecc parity words buffer
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* @ecc_buf2: ecc parity words buffer
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* @xi_tab: GF(2^m) base for solving degree 2 polynomial roots
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* @syn: syndrome buffer
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* @cache: log-based polynomial representation buffer
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* @elp: error locator polynomial
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* @poly_2t: temporary polynomials of degree 2t
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*/
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struct bch_control {
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unsigned int m;
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unsigned int n;
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unsigned int t;
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unsigned int ecc_bits;
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unsigned int ecc_bytes;
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/* private: */
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uint16_t *a_pow_tab;
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uint16_t *a_log_tab;
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uint32_t *mod8_tab;
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uint32_t *ecc_buf;
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uint32_t *ecc_buf2;
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unsigned int *xi_tab;
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unsigned int *syn;
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int *cache;
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struct gf_poly *elp;
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struct gf_poly *poly_2t[4];
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};
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struct bch_control *init_bch(int m, int t, unsigned int prim_poly);
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void free_bch(struct bch_control *bch);
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void encode_bch(struct bch_control *bch, const uint8_t *data,
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unsigned int len, uint8_t *ecc);
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int decode_bch(struct bch_control *bch, const uint8_t *data, unsigned int len,
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const uint8_t *recv_ecc, const uint8_t *calc_ecc,
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const unsigned int *syn, unsigned int *errloc);
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#endif /* _BCH_H */
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@ -18,13 +18,6 @@
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#ifndef __LINUX_MTD_NAND_H
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#define __LINUX_MTD_NAND_H
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/* XXX U-BOOT XXX */
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#if 0
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#include <linux/wait.h>
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#include <linux/spinlock.h>
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#include <linux/mtd/mtd.h>
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#endif
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#include "config.h"
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#include "linux/mtd/compat.h"
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@ -132,6 +125,7 @@ typedef enum {
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NAND_ECC_HW,
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NAND_ECC_HW_SYNDROME,
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NAND_ECC_HW_OOB_FIRST,
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NAND_ECC_SOFT_BCH,
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} nand_ecc_modes_t;
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/*
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@ -308,6 +302,7 @@ struct nand_hw_control {
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* @prepad: padding information for syndrome based ecc generators
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* @postpad: padding information for syndrome based ecc generators
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* @layout: ECC layout control struct pointer
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* @priv: pointer to private ecc control data
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* @hwctl: function to control hardware ecc generator. Must only
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* be provided if an hardware ECC is available
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* @calculate: function for ecc calculation or readback from ecc hardware
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@ -328,6 +323,7 @@ struct nand_ecc_ctrl {
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int prepad;
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int postpad;
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struct nand_ecclayout *layout;
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void *priv;
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void (*hwctl)(struct mtd_info *mtd, int mode);
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int (*calculate)(struct mtd_info *mtd,
|
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const uint8_t *dat,
|
||||
|
|
|
|||
|
|
@ -0,0 +1,72 @@
|
|||
/*
|
||||
* Copyright © 2011 Ivan Djelic <ivan.djelic@parrot.com>
|
||||
*
|
||||
* 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 file is the header for the NAND BCH ECC implementation.
|
||||
*/
|
||||
|
||||
#ifndef __MTD_NAND_BCH_H__
|
||||
#define __MTD_NAND_BCH_H__
|
||||
|
||||
struct mtd_info;
|
||||
struct nand_bch_control;
|
||||
|
||||
#if defined(CONFIG_NAND_ECC_BCH)
|
||||
|
||||
static inline int mtd_nand_has_bch(void) { return 1; }
|
||||
|
||||
/*
|
||||
* Calculate BCH ecc code
|
||||
*/
|
||||
int nand_bch_calculate_ecc(struct mtd_info *mtd, const u_char *dat,
|
||||
u_char *ecc_code);
|
||||
|
||||
/*
|
||||
* Detect and correct bit errors
|
||||
*/
|
||||
int nand_bch_correct_data(struct mtd_info *mtd, u_char *dat, u_char *read_ecc,
|
||||
u_char *calc_ecc);
|
||||
/*
|
||||
* Initialize BCH encoder/decoder
|
||||
*/
|
||||
struct nand_bch_control *
|
||||
nand_bch_init(struct mtd_info *mtd, unsigned int eccsize,
|
||||
unsigned int eccbytes, struct nand_ecclayout **ecclayout);
|
||||
/*
|
||||
* Release BCH encoder/decoder resources
|
||||
*/
|
||||
void nand_bch_free(struct nand_bch_control *nbc);
|
||||
|
||||
#else /* !CONFIG_NAND_ECC_BCH */
|
||||
|
||||
static inline int mtd_nand_has_bch(void) { return 0; }
|
||||
|
||||
static inline int
|
||||
nand_bch_calculate_ecc(struct mtd_info *mtd, const u_char *dat,
|
||||
u_char *ecc_code)
|
||||
{
|
||||
return -1;
|
||||
}
|
||||
|
||||
static inline int
|
||||
nand_bch_correct_data(struct mtd_info *mtd, unsigned char *buf,
|
||||
unsigned char *read_ecc, unsigned char *calc_ecc)
|
||||
{
|
||||
return -1;
|
||||
}
|
||||
|
||||
static inline struct nand_bch_control *
|
||||
nand_bch_init(struct mtd_info *mtd, unsigned int eccsize,
|
||||
unsigned int eccbytes, struct nand_ecclayout **ecclayout)
|
||||
{
|
||||
return NULL;
|
||||
}
|
||||
|
||||
static inline void nand_bch_free(struct nand_bch_control *nbc) {}
|
||||
|
||||
#endif /* CONFIG_NAND_ECC_BCH */
|
||||
|
||||
#endif /* __MTD_NAND_BCH_H__ */
|
||||
|
|
@ -27,6 +27,7 @@ LIB = $(obj)libgeneric.o
|
|||
|
||||
ifndef CONFIG_SPL_BUILD
|
||||
COBJS-$(CONFIG_ADDR_MAP) += addr_map.o
|
||||
COBJS-$(CONFIG_BCH) += bch.o
|
||||
COBJS-$(CONFIG_BZIP2) += bzlib.o
|
||||
COBJS-$(CONFIG_BZIP2) += bzlib_crctable.o
|
||||
COBJS-$(CONFIG_BZIP2) += bzlib_decompress.o
|
||||
|
|
|
|||
Loading…
Reference in New Issue