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Merge branch 'master' of ssh://www.aleph1.co.uk/home/aleph1/git/yaffs2
[yaffs2.git]
/
yaffs_ecc.c
diff --git
a/yaffs_ecc.c
b/yaffs_ecc.c
index 9f5973a5b69b1be6f80d7ea1bc99923f8ca07a89..e95a8069a8c5bc0c754b9f41ddbc9944e0b76f98 100644
(file)
--- a/
yaffs_ecc.c
+++ b/
yaffs_ecc.c
@@
-1,7
+1,7
@@
/*
* YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
*
/*
* YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
*
- * Copyright (C) 2002-20
07
Aleph One Ltd.
+ * Copyright (C) 2002-20
10
Aleph One Ltd.
* for Toby Churchill Ltd and Brightstar Engineering
*
* Created by Charles Manning <charles@aleph1.co.uk>
* for Toby Churchill Ltd and Brightstar Engineering
*
* Created by Charles Manning <charles@aleph1.co.uk>
@@
-28,9
+28,6
@@
* this bytes influence on the line parity.
*/
* this bytes influence on the line parity.
*/
-const char *yaffs_ecc_c_version =
- "$Id: yaffs_ecc.c,v 1.10 2007-12-13 15:35:17 wookey Exp $";
-
#include "yportenv.h"
#include "yaffs_ecc.h"
#include "yportenv.h"
#include "yaffs_ecc.h"
@@
-70,32
+67,9
@@
static const unsigned char column_parity_table[] = {
0x69, 0x3c, 0x30, 0x65, 0x0c, 0x59, 0x55, 0x00,
};
0x69, 0x3c, 0x30, 0x65, 0x0c, 0x59, 0x55, 0x00,
};
-/* Count the bits in an unsigned char or a U32 */
-
-static int yaffs_CountBits(unsigned char x)
-{
- int r = 0;
- while (x) {
- if (x & 1)
- r++;
- x >>= 1;
- }
- return r;
-}
-
-static int yaffs_CountBits32(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 */
/* Calculate the ECC for a 256-byte block of data */
-void yaffs_
ECCCalculate
(const unsigned char *data, unsigned char *ecc)
+void yaffs_
ecc_cacl
(const unsigned char *data, unsigned char *ecc)
{
unsigned int i;
{
unsigned int i;
@@
-109,12
+83,10
@@
void yaffs_ECCCalculate(const unsigned char *data, unsigned char *ecc)
b = column_parity_table[*data++];
col_parity ^= b;
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;
}
line_parity ^= i;
line_parity_prime ^= ~i;
}
-
}
ecc[2] = (~col_parity) | 0x03;
}
ecc[2] = (~col_parity) | 0x03;
@@
-158,18
+130,17
@@
void yaffs_ECCCalculate(const unsigned char *data, unsigned char *ecc)
ecc[0] = ~t;
#ifdef CONFIG_YAFFS_ECC_WRONG_ORDER
ecc[0] = ~t;
#ifdef CONFIG_YAFFS_ECC_WRONG_ORDER
- /
/ Swap the bytes into the wrong order
+ /
* Swap the bytes into the wrong order */
t = ecc[0];
ecc[0] = ecc[1];
ecc[1] = t;
#endif
}
t = ecc[0];
ecc[0] = ecc[1];
ecc[1] = t;
#endif
}
-
/* Correct the ECC on a 256 byte block of data */
/* Correct the ECC on a 256 byte block of data */
-int yaffs_
ECCC
orrect(unsigned char *data, unsigned char *read_ecc,
- const unsigned char *test_ecc)
+int yaffs_
ecc_c
orrect(unsigned char *data, unsigned char *read_ecc,
+
const unsigned char *test_ecc)
{
unsigned char d0, d1, d2; /* deltas */
{
unsigned char d0, d1, d2; /* deltas */
@@
-178,7
+149,7
@@
int yaffs_ECCCorrect(unsigned char *data, unsigned char *read_ecc,
d2 = read_ecc[2] ^ test_ecc[2];
if ((d0 | d1 | d2) == 0)
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 &&
if (((d0 ^ (d0 >> 1)) & 0x55) == 0x55 &&
((d1 ^ (d1 >> 1)) & 0x55) == 0x55 &&
@@
-189,7
+160,7
@@
int yaffs_ECCCorrect(unsigned char *data, unsigned char *read_ecc,
unsigned bit;
#ifdef CONFIG_YAFFS_ECC_WRONG_ORDER
unsigned bit;
#ifdef CONFIG_YAFFS_ECC_WRONG_ORDER
- /
/ swap the bytes to correct for the wrong order
+ /
* swap the bytes to correct for the wrong order */
unsigned char t;
t = d0;
unsigned char t;
t = d0;
@@
-225,19
+196,17
@@
int yaffs_ECCCorrect(unsigned char *data, unsigned char *read_ecc,
data[byte] ^= (1 << bit);
data[byte] ^= (1 << bit);
- return 1; /* Corrected the error */
+ return 1;
/* Corrected the error */
}
}
- if ((yaffs_CountBits(d0) +
- yaffs_CountBits(d1) +
- yaffs_CountBits(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];
/* 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 */
}
/* Unrecoverable error */
@@
-246,12
+215,11
@@
int yaffs_ECCCorrect(unsigned char *data, unsigned char *read_ecc,
}
}
-
/*
* ECCxxxOther does ECC calcs on arbitrary n bytes of data
*/
/*
* ECCxxxOther does ECC calcs on arbitrary n bytes of data
*/
-void yaffs_
ECCCalculateOther(const unsigned char *data, unsigned nB
ytes,
-
yaffs_ECCOther * eccO
ther)
+void yaffs_
ecc_calc_other(const unsigned char *data, unsigned n_b
ytes,
+
struct yaffs_ecc_other *ecc_o
ther)
{
unsigned int i;
{
unsigned int i;
@@
-260,11
+228,11
@@
void yaffs_ECCCalculateOther(const unsigned char *data, unsigned nBytes,
unsigned line_parity_prime = 0;
unsigned char b;
unsigned line_parity_prime = 0;
unsigned char b;
- for (i = 0; i < n
B
ytes; i++) {
+ for (i = 0; i < n
_b
ytes; i++) {
b = column_parity_table[*data++];
col_parity ^= b;
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;
/* odd number of bits in the byte */
line_parity ^= i;
line_parity_prime ^= ~i;
@@
-272,60
+240,59
@@
void yaffs_ECCCalculateOther(const unsigned char *data, unsigned nBytes,
}
}
- ecc
Other->colP
arity = (col_parity >> 2) & 0x3f;
- ecc
Other->lineP
arity = line_parity;
- ecc
Other->lineParityP
rime = line_parity_prime;
+ ecc
_other->col_p
arity = (col_parity >> 2) & 0x3f;
+ ecc
_other->line_p
arity = line_parity;
+ ecc
_other->line_parity_p
rime = line_parity_prime;
}
}
-int yaffs_
ECCCorrectOther(unsigned char *data, unsigned nB
ytes,
-
yaffs_ECCOther *
read_ecc,
-
const yaffs_ECCOther *
test_ecc)
+int yaffs_
ecc_correct_other(unsigned char *data, unsigned n_b
ytes,
+
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;
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 | lDeltaP
rime) == 0)
- return 0; /* no error */
+ if ((
delta_col | delta_line | delta_line_p
rime) == 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;
/* Single bit (recoverable) error in data */
bit = 0;
- if (
cDelta
& 0x20)
+ if (
delta_col
& 0x20)
bit |= 0x04;
bit |= 0x04;
- if (
cDelta
& 0x08)
+ if (
delta_col
& 0x08)
bit |= 0x02;
bit |= 0x02;
- if (
cDelta
& 0x02)
+ if (
delta_col
& 0x02)
bit |= 0x01;
bit |= 0x01;
- if
(lDelta >= nB
ytes)
+ if
(delta_line >= n_b
ytes)
return -1;
return -1;
- data[
lDelta
] ^= (1 << bit);
+ data[
delta_line
] ^= (1 << bit);
- return 1; /* corrected */
+ return 1;
/* corrected */
}
}
- if ((yaffs_CountBits32(lDelta) + yaffs_CountBits32(lDeltaPrime) +
- yaffs_CountBits(cDelta)) == 1) {
+ if ((hweight32(delta_line) +
+ hweight32(delta_line_prime) +
+ hweight8(delta_col)) == 1) {
/* Reccoverable error in ecc */
*read_ecc = *test_ecc;
/* Reccoverable error in ecc */
*read_ecc = *test_ecc;
- return 1; /* corrected */
+ return 1;
/* corrected */
}
/* Unrecoverable error */
return -1;
}
/* Unrecoverable error */
return -1;
-
}
}
-