diff options
author | Boris Brezillon <boris.brezillon@bootlin.com> | 2018-02-05 23:02:04 +0100 |
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committer | Boris Brezillon <boris.brezillon@bootlin.com> | 2018-02-16 10:09:34 +0100 |
commit | 93db446a424cee9387b532995e6b516667079555 (patch) | |
tree | 39c7900ae38d890fb971ea5fc6f194f7e66fa797 /drivers/mtd/nand/nand_ecc.c | |
parent | 7b6afee7291802aa8c02aa918782033992caf641 (diff) | |
download | op-kernel-dev-93db446a424cee9387b532995e6b516667079555.zip op-kernel-dev-93db446a424cee9387b532995e6b516667079555.tar.gz |
mtd: nand: move raw NAND related code to the raw/ subdir
As part of the process of sharing more code between different NAND
based devices, we need to move all raw NAND related code to the raw/
subdirectory.
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Diffstat (limited to 'drivers/mtd/nand/nand_ecc.c')
-rw-r--r-- | drivers/mtd/nand/nand_ecc.c | 531 |
1 files changed, 0 insertions, 531 deletions
diff --git a/drivers/mtd/nand/nand_ecc.c b/drivers/mtd/nand/nand_ecc.c deleted file mode 100644 index 3630f0f..0000000 --- a/drivers/mtd/nand/nand_ecc.c +++ /dev/null @@ -1,531 +0,0 @@ -/* - * This file contains an ECC algorithm that detects and corrects 1 bit - * errors in a 256 byte block of data. - * - * Copyright © 2008 Koninklijke Philips Electronics NV. - * Author: Frans Meulenbroeks - * - * Completely replaces the previous ECC implementation which was written by: - * Steven J. Hill (sjhill@realitydiluted.com) - * Thomas Gleixner (tglx@linutronix.de) - * - * Information on how this algorithm works and how it was developed - * can be found in Documentation/mtd/nand_ecc.txt - * - * This file is free software; you can redistribute it and/or modify it - * under the terms of the GNU General Public License as published by the - * Free Software Foundation; either version 2 or (at your option) any - * later version. - * - * This file is distributed in the hope that it will be useful, but WITHOUT - * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or - * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License - * for more details. - * - * You should have received a copy of the GNU General Public License along - * with this file; if not, write to the Free Software Foundation, Inc., - * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. - * - */ - -/* - * The STANDALONE macro is useful when running the code outside the kernel - * e.g. when running the code in a testbed or a benchmark program. - * When STANDALONE is used, the module related macros are commented out - * as well as the linux include files. - * Instead a private definition of mtd_info is given to satisfy the compiler - * (the code does not use mtd_info, so the code does not care) - */ -#ifndef STANDALONE -#include <linux/types.h> -#include <linux/kernel.h> -#include <linux/module.h> -#include <linux/mtd/mtd.h> -#include <linux/mtd/rawnand.h> -#include <linux/mtd/nand_ecc.h> -#include <asm/byteorder.h> -#else -#include <stdint.h> -struct mtd_info; -#define EXPORT_SYMBOL(x) /* x */ - -#define MODULE_LICENSE(x) /* x */ -#define MODULE_AUTHOR(x) /* x */ -#define MODULE_DESCRIPTION(x) /* x */ - -#define pr_err printf -#endif - -/* - * invparity is a 256 byte table that contains the odd parity - * for each byte. So if the number of bits in a byte is even, - * the array element is 1, and when the number of bits is odd - * the array eleemnt is 0. - */ -static const char invparity[256] = { - 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, - 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, - 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, - 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, - 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, - 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, - 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, - 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, - 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, - 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, - 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, - 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, - 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, - 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, - 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, - 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1 -}; - -/* - * bitsperbyte contains the number of bits per byte - * this is only used for testing and repairing parity - * (a precalculated value slightly improves performance) - */ -static const char bitsperbyte[256] = { - 0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4, - 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, - 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, - 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, - 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, - 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, - 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, - 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, - 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, - 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, - 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, - 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, - 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, - 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, - 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, - 4, 5, 5, 6, 5, 6, 6, 7, 5, 6, 6, 7, 6, 7, 7, 8, -}; - -/* - * addressbits is a lookup table to filter out the bits from the xor-ed - * ECC data that identify the faulty location. - * this is only used for repairing parity - * see the comments in nand_correct_data for more details - */ -static const char addressbits[256] = { - 0x00, 0x00, 0x01, 0x01, 0x00, 0x00, 0x01, 0x01, - 0x02, 0x02, 0x03, 0x03, 0x02, 0x02, 0x03, 0x03, - 0x00, 0x00, 0x01, 0x01, 0x00, 0x00, 0x01, 0x01, - 0x02, 0x02, 0x03, 0x03, 0x02, 0x02, 0x03, 0x03, - 0x04, 0x04, 0x05, 0x05, 0x04, 0x04, 0x05, 0x05, - 0x06, 0x06, 0x07, 0x07, 0x06, 0x06, 0x07, 0x07, - 0x04, 0x04, 0x05, 0x05, 0x04, 0x04, 0x05, 0x05, - 0x06, 0x06, 0x07, 0x07, 0x06, 0x06, 0x07, 0x07, - 0x00, 0x00, 0x01, 0x01, 0x00, 0x00, 0x01, 0x01, - 0x02, 0x02, 0x03, 0x03, 0x02, 0x02, 0x03, 0x03, - 0x00, 0x00, 0x01, 0x01, 0x00, 0x00, 0x01, 0x01, - 0x02, 0x02, 0x03, 0x03, 0x02, 0x02, 0x03, 0x03, - 0x04, 0x04, 0x05, 0x05, 0x04, 0x04, 0x05, 0x05, - 0x06, 0x06, 0x07, 0x07, 0x06, 0x06, 0x07, 0x07, - 0x04, 0x04, 0x05, 0x05, 0x04, 0x04, 0x05, 0x05, - 0x06, 0x06, 0x07, 0x07, 0x06, 0x06, 0x07, 0x07, - 0x08, 0x08, 0x09, 0x09, 0x08, 0x08, 0x09, 0x09, - 0x0a, 0x0a, 0x0b, 0x0b, 0x0a, 0x0a, 0x0b, 0x0b, - 0x08, 0x08, 0x09, 0x09, 0x08, 0x08, 0x09, 0x09, - 0x0a, 0x0a, 0x0b, 0x0b, 0x0a, 0x0a, 0x0b, 0x0b, - 0x0c, 0x0c, 0x0d, 0x0d, 0x0c, 0x0c, 0x0d, 0x0d, - 0x0e, 0x0e, 0x0f, 0x0f, 0x0e, 0x0e, 0x0f, 0x0f, - 0x0c, 0x0c, 0x0d, 0x0d, 0x0c, 0x0c, 0x0d, 0x0d, - 0x0e, 0x0e, 0x0f, 0x0f, 0x0e, 0x0e, 0x0f, 0x0f, - 0x08, 0x08, 0x09, 0x09, 0x08, 0x08, 0x09, 0x09, - 0x0a, 0x0a, 0x0b, 0x0b, 0x0a, 0x0a, 0x0b, 0x0b, - 0x08, 0x08, 0x09, 0x09, 0x08, 0x08, 0x09, 0x09, - 0x0a, 0x0a, 0x0b, 0x0b, 0x0a, 0x0a, 0x0b, 0x0b, - 0x0c, 0x0c, 0x0d, 0x0d, 0x0c, 0x0c, 0x0d, 0x0d, - 0x0e, 0x0e, 0x0f, 0x0f, 0x0e, 0x0e, 0x0f, 0x0f, - 0x0c, 0x0c, 0x0d, 0x0d, 0x0c, 0x0c, 0x0d, 0x0d, - 0x0e, 0x0e, 0x0f, 0x0f, 0x0e, 0x0e, 0x0f, 0x0f -}; - -/** - * __nand_calculate_ecc - [NAND Interface] Calculate 3-byte ECC for 256/512-byte - * block - * @buf: input buffer with raw data - * @eccsize: data bytes per ECC step (256 or 512) - * @code: output buffer with ECC - */ -void __nand_calculate_ecc(const unsigned char *buf, unsigned int eccsize, - unsigned char *code) -{ - int i; - const uint32_t *bp = (uint32_t *)buf; - /* 256 or 512 bytes/ecc */ - const uint32_t eccsize_mult = eccsize >> 8; - uint32_t cur; /* current value in buffer */ - /* rp0..rp15..rp17 are the various accumulated parities (per byte) */ - uint32_t rp0, rp1, rp2, rp3, rp4, rp5, rp6, rp7; - uint32_t rp8, rp9, rp10, rp11, rp12, rp13, rp14, rp15, rp16; - uint32_t uninitialized_var(rp17); /* to make compiler happy */ - uint32_t par; /* the cumulative parity for all data */ - uint32_t tmppar; /* the cumulative parity for this iteration; - for rp12, rp14 and rp16 at the end of the - loop */ - - par = 0; - rp4 = 0; - rp6 = 0; - rp8 = 0; - rp10 = 0; - rp12 = 0; - rp14 = 0; - rp16 = 0; - - /* - * The loop is unrolled a number of times; - * This avoids if statements to decide on which rp value to update - * Also we process the data by longwords. - * Note: passing unaligned data might give a performance penalty. - * It is assumed that the buffers are aligned. - * tmppar is the cumulative sum of this iteration. - * needed for calculating rp12, rp14, rp16 and par - * also used as a performance improvement for rp6, rp8 and rp10 - */ - for (i = 0; i < eccsize_mult << 2; i++) { - cur = *bp++; - tmppar = cur; - rp4 ^= cur; - cur = *bp++; - tmppar ^= cur; - rp6 ^= tmppar; - cur = *bp++; - tmppar ^= cur; - rp4 ^= cur; - cur = *bp++; - tmppar ^= cur; - rp8 ^= tmppar; - - cur = *bp++; - tmppar ^= cur; - rp4 ^= cur; - rp6 ^= cur; - cur = *bp++; - tmppar ^= cur; - rp6 ^= cur; - cur = *bp++; - tmppar ^= cur; - rp4 ^= cur; - cur = *bp++; - tmppar ^= cur; - rp10 ^= tmppar; - - cur = *bp++; - tmppar ^= cur; - rp4 ^= cur; - rp6 ^= cur; - rp8 ^= cur; - cur = *bp++; - tmppar ^= cur; - rp6 ^= cur; - rp8 ^= cur; - cur = *bp++; - tmppar ^= cur; - rp4 ^= cur; - rp8 ^= cur; - cur = *bp++; - tmppar ^= cur; - rp8 ^= cur; - - cur = *bp++; - tmppar ^= cur; - rp4 ^= cur; - rp6 ^= cur; - cur = *bp++; - tmppar ^= cur; - rp6 ^= cur; - cur = *bp++; - tmppar ^= cur; - rp4 ^= cur; - cur = *bp++; - tmppar ^= cur; - - par ^= tmppar; - if ((i & 0x1) == 0) - rp12 ^= tmppar; - if ((i & 0x2) == 0) - rp14 ^= tmppar; - if (eccsize_mult == 2 && (i & 0x4) == 0) - rp16 ^= tmppar; - } - - /* - * handle the fact that we use longword operations - * we'll bring rp4..rp14..rp16 back to single byte entities by - * shifting and xoring first fold the upper and lower 16 bits, - * then the upper and lower 8 bits. - */ - rp4 ^= (rp4 >> 16); - rp4 ^= (rp4 >> 8); - rp4 &= 0xff; - rp6 ^= (rp6 >> 16); - rp6 ^= (rp6 >> 8); - rp6 &= 0xff; - rp8 ^= (rp8 >> 16); - rp8 ^= (rp8 >> 8); - rp8 &= 0xff; - rp10 ^= (rp10 >> 16); - rp10 ^= (rp10 >> 8); - rp10 &= 0xff; - rp12 ^= (rp12 >> 16); - rp12 ^= (rp12 >> 8); - rp12 &= 0xff; - rp14 ^= (rp14 >> 16); - rp14 ^= (rp14 >> 8); - rp14 &= 0xff; - if (eccsize_mult == 2) { - rp16 ^= (rp16 >> 16); - rp16 ^= (rp16 >> 8); - rp16 &= 0xff; - } - - /* - * we also need to calculate the row parity for rp0..rp3 - * This is present in par, because par is now - * rp3 rp3 rp2 rp2 in little endian and - * rp2 rp2 rp3 rp3 in big endian - * as well as - * rp1 rp0 rp1 rp0 in little endian and - * rp0 rp1 rp0 rp1 in big endian - * First calculate rp2 and rp3 - */ -#ifdef __BIG_ENDIAN - rp2 = (par >> 16); - rp2 ^= (rp2 >> 8); - rp2 &= 0xff; - rp3 = par & 0xffff; - rp3 ^= (rp3 >> 8); - rp3 &= 0xff; -#else - rp3 = (par >> 16); - rp3 ^= (rp3 >> 8); - rp3 &= 0xff; - rp2 = par & 0xffff; - rp2 ^= (rp2 >> 8); - rp2 &= 0xff; -#endif - - /* reduce par to 16 bits then calculate rp1 and rp0 */ - par ^= (par >> 16); -#ifdef __BIG_ENDIAN - rp0 = (par >> 8) & 0xff; - rp1 = (par & 0xff); -#else - rp1 = (par >> 8) & 0xff; - rp0 = (par & 0xff); -#endif - - /* finally reduce par to 8 bits */ - par ^= (par >> 8); - par &= 0xff; - - /* - * and calculate rp5..rp15..rp17 - * note that par = rp4 ^ rp5 and due to the commutative property - * of the ^ operator we can say: - * rp5 = (par ^ rp4); - * The & 0xff seems superfluous, but benchmarking learned that - * leaving it out gives slightly worse results. No idea why, probably - * it has to do with the way the pipeline in pentium is organized. - */ - rp5 = (par ^ rp4) & 0xff; - rp7 = (par ^ rp6) & 0xff; - rp9 = (par ^ rp8) & 0xff; - rp11 = (par ^ rp10) & 0xff; - rp13 = (par ^ rp12) & 0xff; - rp15 = (par ^ rp14) & 0xff; - if (eccsize_mult == 2) - rp17 = (par ^ rp16) & 0xff; - - /* - * Finally calculate the ECC bits. - * Again here it might seem that there are performance optimisations - * possible, but benchmarks showed that on the system this is developed - * the code below is the fastest - */ -#ifdef CONFIG_MTD_NAND_ECC_SMC - code[0] = - (invparity[rp7] << 7) | - (invparity[rp6] << 6) | - (invparity[rp5] << 5) | - (invparity[rp4] << 4) | - (invparity[rp3] << 3) | - (invparity[rp2] << 2) | - (invparity[rp1] << 1) | - (invparity[rp0]); - code[1] = - (invparity[rp15] << 7) | - (invparity[rp14] << 6) | - (invparity[rp13] << 5) | - (invparity[rp12] << 4) | - (invparity[rp11] << 3) | - (invparity[rp10] << 2) | - (invparity[rp9] << 1) | - (invparity[rp8]); -#else - code[1] = - (invparity[rp7] << 7) | - (invparity[rp6] << 6) | - (invparity[rp5] << 5) | - (invparity[rp4] << 4) | - (invparity[rp3] << 3) | - (invparity[rp2] << 2) | - (invparity[rp1] << 1) | - (invparity[rp0]); - code[0] = - (invparity[rp15] << 7) | - (invparity[rp14] << 6) | - (invparity[rp13] << 5) | - (invparity[rp12] << 4) | - (invparity[rp11] << 3) | - (invparity[rp10] << 2) | - (invparity[rp9] << 1) | - (invparity[rp8]); -#endif - if (eccsize_mult == 1) - code[2] = - (invparity[par & 0xf0] << 7) | - (invparity[par & 0x0f] << 6) | - (invparity[par & 0xcc] << 5) | - (invparity[par & 0x33] << 4) | - (invparity[par & 0xaa] << 3) | - (invparity[par & 0x55] << 2) | - 3; - else - code[2] = - (invparity[par & 0xf0] << 7) | - (invparity[par & 0x0f] << 6) | - (invparity[par & 0xcc] << 5) | - (invparity[par & 0x33] << 4) | - (invparity[par & 0xaa] << 3) | - (invparity[par & 0x55] << 2) | - (invparity[rp17] << 1) | - (invparity[rp16] << 0); -} -EXPORT_SYMBOL(__nand_calculate_ecc); - -/** - * nand_calculate_ecc - [NAND Interface] Calculate 3-byte ECC for 256/512-byte - * block - * @mtd: MTD block structure - * @buf: input buffer with raw data - * @code: output buffer with ECC - */ -int nand_calculate_ecc(struct mtd_info *mtd, const unsigned char *buf, - unsigned char *code) -{ - __nand_calculate_ecc(buf, - mtd_to_nand(mtd)->ecc.size, code); - - return 0; -} -EXPORT_SYMBOL(nand_calculate_ecc); - -/** - * __nand_correct_data - [NAND Interface] Detect and correct bit error(s) - * @buf: raw data read from the chip - * @read_ecc: ECC from the chip - * @calc_ecc: the ECC calculated from raw data - * @eccsize: data bytes per ECC step (256 or 512) - * - * Detect and correct a 1 bit error for eccsize byte block - */ -int __nand_correct_data(unsigned char *buf, - unsigned char *read_ecc, unsigned char *calc_ecc, - unsigned int eccsize) -{ - unsigned char b0, b1, b2, bit_addr; - unsigned int byte_addr; - /* 256 or 512 bytes/ecc */ - const uint32_t eccsize_mult = eccsize >> 8; - - /* - * b0 to b2 indicate which bit is faulty (if any) - * we might need the xor result more than once, - * so keep them in a local var - */ -#ifdef CONFIG_MTD_NAND_ECC_SMC - b0 = read_ecc[0] ^ calc_ecc[0]; - b1 = read_ecc[1] ^ calc_ecc[1]; -#else - b0 = read_ecc[1] ^ calc_ecc[1]; - b1 = read_ecc[0] ^ calc_ecc[0]; -#endif - b2 = read_ecc[2] ^ calc_ecc[2]; - - /* check if there are any bitfaults */ - - /* repeated if statements are slightly more efficient than switch ... */ - /* ordered in order of likelihood */ - - if ((b0 | b1 | b2) == 0) - return 0; /* no error */ - - if ((((b0 ^ (b0 >> 1)) & 0x55) == 0x55) && - (((b1 ^ (b1 >> 1)) & 0x55) == 0x55) && - ((eccsize_mult == 1 && ((b2 ^ (b2 >> 1)) & 0x54) == 0x54) || - (eccsize_mult == 2 && ((b2 ^ (b2 >> 1)) & 0x55) == 0x55))) { - /* single bit error */ - /* - * rp17/rp15/13/11/9/7/5/3/1 indicate which byte is the faulty - * byte, cp 5/3/1 indicate the faulty bit. - * A lookup table (called addressbits) is used to filter - * the bits from the byte they are in. - * A marginal optimisation is possible by having three - * different lookup tables. - * One as we have now (for b0), one for b2 - * (that would avoid the >> 1), and one for b1 (with all values - * << 4). However it was felt that introducing two more tables - * hardly justify the gain. - * - * The b2 shift is there to get rid of the lowest two bits. - * We could also do addressbits[b2] >> 1 but for the - * performance it does not make any difference - */ - if (eccsize_mult == 1) - byte_addr = (addressbits[b1] << 4) + addressbits[b0]; - else - byte_addr = (addressbits[b2 & 0x3] << 8) + - (addressbits[b1] << 4) + addressbits[b0]; - bit_addr = addressbits[b2 >> 2]; - /* flip the bit */ - buf[byte_addr] ^= (1 << bit_addr); - return 1; - - } - /* count nr of bits; use table lookup, faster than calculating it */ - if ((bitsperbyte[b0] + bitsperbyte[b1] + bitsperbyte[b2]) == 1) - return 1; /* error in ECC data; no action needed */ - - pr_err("%s: uncorrectable ECC error\n", __func__); - return -EBADMSG; -} -EXPORT_SYMBOL(__nand_correct_data); - -/** - * nand_correct_data - [NAND Interface] Detect and correct bit error(s) - * @mtd: MTD block structure - * @buf: raw data read from the chip - * @read_ecc: ECC from the chip - * @calc_ecc: the ECC calculated from raw data - * - * Detect and correct a 1 bit error for 256/512 byte block - */ -int nand_correct_data(struct mtd_info *mtd, unsigned char *buf, - unsigned char *read_ecc, unsigned char *calc_ecc) -{ - return __nand_correct_data(buf, read_ecc, calc_ecc, - mtd_to_nand(mtd)->ecc.size); -} -EXPORT_SYMBOL(nand_correct_data); - -MODULE_LICENSE("GPL"); -MODULE_AUTHOR("Frans Meulenbroeks <fransmeulenbroeks@gmail.com>"); -MODULE_DESCRIPTION("Generic NAND ECC support"); |