diff options
Diffstat (limited to 'drivers/mtd/nand')
| -rw-r--r-- | drivers/mtd/nand/nand_ecc.c | 86 |
1 files changed, 62 insertions, 24 deletions
diff --git a/drivers/mtd/nand/nand_ecc.c b/drivers/mtd/nand/nand_ecc.c index fd19787c9ce..868147acce2 100644 --- a/drivers/mtd/nand/nand_ecc.c +++ b/drivers/mtd/nand/nand_ecc.c @@ -42,6 +42,8 @@ #include <linux/types.h> #include <linux/kernel.h> #include <linux/module.h> +#include <linux/mtd/mtd.h> +#include <linux/mtd/nand.h> #include <linux/mtd/nand_ecc.h> #include <asm/byteorder.h> #else @@ -148,8 +150,9 @@ static const char addressbits[256] = { }; /** - * nand_calculate_ecc - [NAND Interface] Calculate 3-byte ECC for 256-byte block - * @mtd: MTD block structure (unused) + * 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 */ @@ -158,13 +161,18 @@ int nand_calculate_ecc(struct mtd_info *mtd, const unsigned char *buf, { int i; const uint32_t *bp = (uint32_t *)buf; + /* 256 or 512 bytes/ecc */ + const uint32_t eccsize_mult = + (((struct nand_chip *)mtd->priv)->ecc.size) >> 8; uint32_t cur; /* current value in buffer */ - /* rp0..rp15 are the various accumulated parities (per byte) */ + /* 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; + 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 and rp14 at the end of the loop */ + for rp12, rp14 and rp16 at the end of the + loop */ par = 0; rp4 = 0; @@ -173,6 +181,7 @@ int nand_calculate_ecc(struct mtd_info *mtd, const unsigned char *buf, rp10 = 0; rp12 = 0; rp14 = 0; + rp16 = 0; /* * The loop is unrolled a number of times; @@ -181,10 +190,10 @@ int nand_calculate_ecc(struct mtd_info *mtd, const unsigned char *buf, * 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 and par + * needed for calculating rp12, rp14, rp16 and par * also used as a performance improvement for rp6, rp8 and rp10 */ - for (i = 0; i < 4; i++) { + for (i = 0; i < eccsize_mult << 2; i++) { cur = *bp++; tmppar = cur; rp4 ^= cur; @@ -247,12 +256,14 @@ int nand_calculate_ecc(struct mtd_info *mtd, const unsigned char *buf, 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 back to single byte entities by shifting and - * xoring first fold the upper and lower 16 bits, + * 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); @@ -273,6 +284,11 @@ int nand_calculate_ecc(struct mtd_info *mtd, const unsigned char *buf, 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 @@ -315,7 +331,7 @@ int nand_calculate_ecc(struct mtd_info *mtd, const unsigned char *buf, par &= 0xff; /* - * and calculate rp5..rp15 + * 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); @@ -329,6 +345,8 @@ int nand_calculate_ecc(struct mtd_info *mtd, const unsigned char *buf, 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. @@ -375,32 +393,46 @@ int nand_calculate_ecc(struct mtd_info *mtd, const unsigned char *buf, (invparity[rp9] << 1) | (invparity[rp8]); #endif - 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; + 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); return 0; } EXPORT_SYMBOL(nand_calculate_ecc); /** * nand_correct_data - [NAND Interface] Detect and correct bit error(s) - * @mtd: MTD block structure (unused) + * @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 byte block + * 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) { unsigned char b0, b1, b2; unsigned char byte_addr, bit_addr; + /* 256 or 512 bytes/ecc */ + const uint32_t eccsize_mult = + (((struct nand_chip *)mtd->priv)->ecc.size) >> 8; /* * b0 to b2 indicate which bit is faulty (if any) @@ -426,10 +458,12 @@ int nand_correct_data(struct mtd_info *mtd, unsigned char *buf, if ((((b0 ^ (b0 >> 1)) & 0x55) == 0x55) && (((b1 ^ (b1 >> 1)) & 0x55) == 0x55) && - (((b2 ^ (b2 >> 1)) & 0x54) == 0x54)) { /* single bit error */ + ((eccsize_mult == 1 && ((b2 ^ (b2 >> 1)) & 0x54) == 0x54) || + (eccsize_mult == 2 && ((b2 ^ (b2 >> 1)) & 0x55) == 0x55))) { + /* single bit error */ /* - * rp15/13/11/9/7/5/3/1 indicate which byte is the faulty byte - * cp 5/3/1 indicate the faulty bit. + * 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 @@ -443,7 +477,11 @@ int nand_correct_data(struct mtd_info *mtd, unsigned char *buf, * We could also do addressbits[b2] >> 1 but for the * performace it does not make any difference */ - byte_addr = (addressbits[b1] << 4) + addressbits[b0]; + 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); |