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-rw-r--r--uart-monitor/lib/ecc_512.c420
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diff --git a/uart-monitor/lib/ecc_512.c b/uart-monitor/lib/ecc_512.c
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-/*
- * (C) Copyright 2000 Texas Instruments
- *
- * This file os based on the following u-boot file:
- * common/cmd_nand.c
- *
- * See file CREDITS for list of people who contributed to this
- * project.
- *
- * This program 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 of
- * the License, or (at your option) any later version.
- *
- * This program 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 program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
- * MA 02111-1307 USA
- */
-#include <common.h>
-
-#ifdef CFG_SW_ECC_512
-
-/*
- * 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
- * @mtd: MTD block structure
- * @buf: input buffer with raw data
- * @code: output buffer with ECC
- */
-void nand_calculate_ecc(const u_char *buf, u_char *code)
-{
- int i;
- const uint32_t *bp = (uint32_t *)buf;
- /* 256 or 512 bytes/ecc */
- int eccsize = 512;
- 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 rp17 = 0;
- 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
- */
- rp3 = (par >> 16);
- rp3 ^= (rp3 >> 8);
- rp3 &= 0xff;
- rp2 = par & 0xffff;
- rp2 ^= (rp2 >> 8);
- rp2 &= 0xff;
-
- /* reduce par to 16 bits then calculate rp1 and rp0 */
- par ^= (par >> 16);
- rp1 = (par >> 8) & 0xff;
- rp0 = (par & 0xff);
-
- /* 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
- */
- 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]);
- 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);
-}
-
-/**
- * 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(unsigned char *buf,
- unsigned char *read_ecc, unsigned char *calc_ecc)
-{
- unsigned char b0, b1, b2;
- uint32_t byte_addr;
- unsigned char bit_addr;
- /* 256 or 512 bytes/ecc */
- int eccsize = 512;
- 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
- */
- b0 = read_ecc[1] ^ calc_ecc[1];
- b1 = read_ecc[0] ^ calc_ecc[0];
- 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
- * performace 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 */
-
- return -1;
-}
-#endif /* CFG_SW_ECC_512 */