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author | Gabor Juhos <juhosg@openwrt.org> | 2013-12-16 07:51:19 +0000 |
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committer | Gabor Juhos <juhosg@openwrt.org> | 2013-12-16 07:51:19 +0000 |
commit | a8feb12f58ff4bbedfc448cd99107f130bc322a8 (patch) | |
tree | c3baa813b2d49c1e5302c7561a89be81af5b3fe0 /target/linux/generic/files/fs/yaffs2/yaffs_ecc.c | |
parent | a8bc7f528ac71cb6b7405c12cc3c1878b2992164 (diff) | |
download | upstream-a8feb12f58ff4bbedfc448cd99107f130bc322a8.tar.gz upstream-a8feb12f58ff4bbedfc448cd99107f130bc322a8.tar.bz2 upstream-a8feb12f58ff4bbedfc448cd99107f130bc322a8.zip |
kernel: update yaffs code
Use the latest version of the yaffs code. Fetched from the
yaffs2 git tree and it is based on the following commit:
commit bc76682d93955cfb33051beb503ad9f8a5450578
Merge: 3a8580e ffa781d
Author: Charles Manning <cdhmanning@gmail.com>
Date: Thu Jul 11 17:46:25 2013 +1200
Merge branch 'master' of ssh://www.aleph1.co.uk/home/aleph1/git/yaffs2
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@39084 3c298f89-4303-0410-b956-a3cf2f4a3e73
Diffstat (limited to 'target/linux/generic/files/fs/yaffs2/yaffs_ecc.c')
-rw-r--r-- | target/linux/generic/files/fs/yaffs2/yaffs_ecc.c | 130 |
1 files changed, 44 insertions, 86 deletions
diff --git a/target/linux/generic/files/fs/yaffs2/yaffs_ecc.c b/target/linux/generic/files/fs/yaffs2/yaffs_ecc.c index 4030908d51..9294107c15 100644 --- a/target/linux/generic/files/fs/yaffs2/yaffs_ecc.c +++ b/target/linux/generic/files/fs/yaffs2/yaffs_ecc.c @@ -1,7 +1,7 @@ /* * YAFFS: Yet Another Flash File System. A NAND-flash specific file system. * - * Copyright (C) 2002-2010 Aleph One Ltd. + * Copyright (C) 2002-2011 Aleph One Ltd. * for Toby Churchill Ltd and Brightstar Engineering * * Created by Charles Manning <charles@aleph1.co.uk> @@ -16,22 +16,22 @@ * * The ECC comprises 22 bits of parity information and is stuffed into 3 bytes. * The two unused bit are set to 1. - * The ECC can correct single bit errors in a 256-byte page of data. Thus, two such ECC - * blocks are used on a 512-byte NAND page. + * The ECC can correct single bit errors in a 256-byte page of data. Thus, two + * such ECC blocks are used on a 512-byte NAND page. * */ +#include "yportenv.h" + +#include "yaffs_ecc.h" + /* Table generated by gen-ecc.c * Using a table means we do not have to calculate p1..p4 and p1'..p4' * for each byte of data. These are instead provided in a table in bits7..2. - * Bit 0 of each entry indicates whether the entry has an odd or even parity, and therefore - * this bytes influence on the line parity. + * Bit 0 of each entry indicates whether the entry has an odd or even parity, + * and therefore this bytes influence on the line parity. */ -#include "yportenv.h" - -#include "yaffs_ecc.h" - static const unsigned char column_parity_table[] = { 0x00, 0x55, 0x59, 0x0c, 0x65, 0x30, 0x3c, 0x69, 0x69, 0x3c, 0x30, 0x65, 0x0c, 0x59, 0x55, 0x00, @@ -67,35 +67,11 @@ static const unsigned char column_parity_table[] = { 0x69, 0x3c, 0x30, 0x65, 0x0c, 0x59, 0x55, 0x00, }; -/* Count the bits in an unsigned char or a U32 */ - -static int yaffs_count_bits(unsigned char x) -{ - int r = 0; - while (x) { - if (x & 1) - r++; - x >>= 1; - } - return r; -} - -static int yaffs_count_bits32(unsigned x) -{ - int r = 0; - while (x) { - if (x & 1) - r++; - x >>= 1; - } - return r; -} /* Calculate the ECC for a 256-byte block of data */ -void yaffs_ecc_cacl(const unsigned char *data, unsigned char *ecc) +void yaffs_ecc_calc(const unsigned char *data, unsigned char *ecc) { unsigned int i; - unsigned char col_parity = 0; unsigned char line_parity = 0; unsigned char line_parity_prime = 0; @@ -106,7 +82,7 @@ void yaffs_ecc_cacl(const unsigned char *data, unsigned char *ecc) b = column_parity_table[*data++]; col_parity ^= b; - if (b & 0x01) { /* odd number of bits in the byte */ + if (b & 0x01) { /* odd number of bits in the byte */ line_parity ^= i; line_parity_prime ^= ~i; } @@ -152,19 +128,12 @@ void yaffs_ecc_cacl(const unsigned char *data, unsigned char *ecc) t |= 0x01; ecc[0] = ~t; -#ifdef CONFIG_YAFFS_ECC_WRONG_ORDER - /* Swap the bytes into the wrong order */ - t = ecc[0]; - ecc[0] = ecc[1]; - ecc[1] = t; -#endif } - /* Correct the ECC on a 256 byte block of data */ int yaffs_ecc_correct(unsigned char *data, unsigned char *read_ecc, - const unsigned char *test_ecc) + const unsigned char *test_ecc) { unsigned char d0, d1, d2; /* deltas */ @@ -173,7 +142,7 @@ int yaffs_ecc_correct(unsigned char *data, unsigned char *read_ecc, d2 = read_ecc[2] ^ test_ecc[2]; if ((d0 | d1 | d2) == 0) - return 0; /* no error */ + return 0; /* no error */ if (((d0 ^ (d0 >> 1)) & 0x55) == 0x55 && ((d1 ^ (d1 >> 1)) & 0x55) == 0x55 && @@ -183,15 +152,6 @@ int yaffs_ecc_correct(unsigned char *data, unsigned char *read_ecc, unsigned byte; unsigned bit; -#ifdef CONFIG_YAFFS_ECC_WRONG_ORDER - /* swap the bytes to correct for the wrong order */ - unsigned char t; - - t = d0; - d0 = d1; - d1 = t; -#endif - bit = byte = 0; if (d1 & 0x80) @@ -220,19 +180,17 @@ int yaffs_ecc_correct(unsigned char *data, unsigned char *read_ecc, data[byte] ^= (1 << bit); - return 1; /* Corrected the error */ + return 1; /* Corrected the error */ } - if ((yaffs_count_bits(d0) + - yaffs_count_bits(d1) + - yaffs_count_bits(d2)) == 1) { + if ((hweight8(d0) + hweight8(d1) + hweight8(d2)) == 1) { /* Reccoverable error in ecc */ read_ecc[0] = test_ecc[0]; read_ecc[1] = test_ecc[1]; read_ecc[2] = test_ecc[2]; - return 1; /* Corrected the error */ + return 1; /* Corrected the error */ } /* Unrecoverable error */ @@ -241,15 +199,13 @@ int yaffs_ecc_correct(unsigned char *data, unsigned char *read_ecc, } - /* * ECCxxxOther does ECC calcs on arbitrary n bytes of data */ void yaffs_ecc_calc_other(const unsigned char *data, unsigned n_bytes, - yaffs_ECCOther *eccOther) + struct yaffs_ecc_other *ecc_other) { unsigned int i; - unsigned char col_parity = 0; unsigned line_parity = 0; unsigned line_parity_prime = 0; @@ -259,7 +215,7 @@ void yaffs_ecc_calc_other(const unsigned char *data, unsigned n_bytes, b = column_parity_table[*data++]; col_parity ^= b; - if (b & 0x01) { + if (b & 0x01) { /* odd number of bits in the byte */ line_parity ^= i; line_parity_prime ^= ~i; @@ -267,54 +223,56 @@ void yaffs_ecc_calc_other(const unsigned char *data, unsigned n_bytes, } - eccOther->colParity = (col_parity >> 2) & 0x3f; - eccOther->lineParity = line_parity; - eccOther->lineParityPrime = line_parity_prime; + ecc_other->col_parity = (col_parity >> 2) & 0x3f; + ecc_other->line_parity = line_parity; + ecc_other->line_parity_prime = line_parity_prime; } int yaffs_ecc_correct_other(unsigned char *data, unsigned n_bytes, - yaffs_ECCOther *read_ecc, - const yaffs_ECCOther *test_ecc) + struct yaffs_ecc_other *read_ecc, + const struct yaffs_ecc_other *test_ecc) { - unsigned char cDelta; /* column parity delta */ - unsigned lDelta; /* line parity delta */ - unsigned lDeltaPrime; /* line parity delta */ + unsigned char delta_col; /* column parity delta */ + unsigned delta_line; /* line parity delta */ + unsigned delta_line_prime; /* line parity delta */ unsigned bit; - cDelta = read_ecc->colParity ^ test_ecc->colParity; - lDelta = read_ecc->lineParity ^ test_ecc->lineParity; - lDeltaPrime = read_ecc->lineParityPrime ^ test_ecc->lineParityPrime; + delta_col = read_ecc->col_parity ^ test_ecc->col_parity; + delta_line = read_ecc->line_parity ^ test_ecc->line_parity; + delta_line_prime = + read_ecc->line_parity_prime ^ test_ecc->line_parity_prime; - if ((cDelta | lDelta | lDeltaPrime) == 0) - return 0; /* no error */ + if ((delta_col | delta_line | delta_line_prime) == 0) + return 0; /* no error */ - if (lDelta == ~lDeltaPrime && - (((cDelta ^ (cDelta >> 1)) & 0x15) == 0x15)) { + if (delta_line == ~delta_line_prime && + (((delta_col ^ (delta_col >> 1)) & 0x15) == 0x15)) { /* Single bit (recoverable) error in data */ bit = 0; - if (cDelta & 0x20) + if (delta_col & 0x20) bit |= 0x04; - if (cDelta & 0x08) + if (delta_col & 0x08) bit |= 0x02; - if (cDelta & 0x02) + if (delta_col & 0x02) bit |= 0x01; - if (lDelta >= n_bytes) + if (delta_line >= n_bytes) return -1; - data[lDelta] ^= (1 << bit); + data[delta_line] ^= (1 << bit); - return 1; /* corrected */ + return 1; /* corrected */ } - if ((yaffs_count_bits32(lDelta) + yaffs_count_bits32(lDeltaPrime) + - yaffs_count_bits(cDelta)) == 1) { + if ((hweight32(delta_line) + + hweight32(delta_line_prime) + + hweight8(delta_col)) == 1) { /* Reccoverable error in ecc */ *read_ecc = *test_ecc; - return 1; /* corrected */ + return 1; /* corrected */ } /* Unrecoverable error */ |