This updates BCH support from Linux as of Linux-6.9-rc2. Among other things in Linux the bch function names changed from a _bch suffix to a bch_ prefix.
Link: https://lore.barebox.org/20240416062147.1337233-1-s.ha...@pengutronix.de Signed-off-by: Sascha Hauer <s.ha...@pengutronix.de> --- common/imx-bbu-nand-fcb.c | 12 +-- drivers/mtd/devices/docg3.c | 8 +- drivers/mtd/nand/nand_bch.c | 10 +-- include/linux/bch.h | 25 ++---- lib/Kconfig | 1 + lib/bch.c | 167 +++++++++++++++++++++++------------- 6 files changed, 130 insertions(+), 93 deletions(-) diff --git a/common/imx-bbu-nand-fcb.c b/common/imx-bbu-nand-fcb.c index 0d46192720..d0261140cf 100644 --- a/common/imx-bbu-nand-fcb.c +++ b/common/imx-bbu-nand-fcb.c @@ -79,7 +79,7 @@ static void encode_bch_ecc(void *buf, struct fcb_block *fcb, int eccbits) int blocksize = 128; int numblocks = 8; int ecc_buf_size = (m * eccbits + 7) / 8; - struct bch_control *bch = init_bch(m, eccbits, 0); + struct bch_control *bch = bch_init(m, eccbits, 0, false); uint8_t *ecc_buf = xmalloc(ecc_buf_size); uint8_t *tmp_buf = xzalloc(blocksize * numblocks); uint8_t *psrc, *pdst; @@ -109,7 +109,7 @@ static void encode_bch_ecc(void *buf, struct fcb_block *fcb, int eccbits) for (j = 0; j < blocksize; j++) psrc[j] = reverse_bit(psrc[j]); - encode_bch(bch, psrc, blocksize, ecc_buf); + bch_encode(bch, psrc, blocksize, ecc_buf); /* reverse ecc bit */ for (j = 0; j < ecc_buf_size; j++) @@ -121,7 +121,7 @@ static void encode_bch_ecc(void *buf, struct fcb_block *fcb, int eccbits) free(ecc_buf); free(tmp_buf); - free_bch(bch); + bch_free(bch); } static struct fcb_block *fcb_decode_bch(void *rawpage, int eccbits) @@ -130,7 +130,7 @@ static struct fcb_block *fcb_decode_bch(void *rawpage, int eccbits) int blocksize = 128; int numblocks = 8; int ecc_buf_size = (m * eccbits + 7) / 8; - struct bch_control *bch = init_bch(m, eccbits, 0); + struct bch_control *bch = bch_init(m, eccbits, 0, false); uint8_t *fcb = xmalloc(numblocks * blocksize); uint8_t *ecc_buf = xmalloc(ecc_buf_size); uint8_t *data_buf = xmalloc(blocksize); @@ -152,7 +152,7 @@ static struct fcb_block *fcb_decode_bch(void *rawpage, int eccbits) for (j = 0; j < ecc_buf_size; j++) ecc_buf[j] = reverse_bit(psrc[j + blocksize]); - ret = decode_bch(bch, data_buf, blocksize, ecc_buf, + ret = bch_decode(bch, data_buf, blocksize, ecc_buf, NULL, NULL, errloc); if (ret < 0) { @@ -185,7 +185,7 @@ static struct fcb_block *fcb_decode_bch(void *rawpage, int eccbits) free(data_buf); free(ecc_buf); free(errloc); - free_bch(bch); + bch_free(bch); return (struct fcb_block *)fcb; } diff --git a/drivers/mtd/devices/docg3.c b/drivers/mtd/devices/docg3.c index 593a7035e5..fcf9403b8f 100644 --- a/drivers/mtd/devices/docg3.c +++ b/drivers/mtd/devices/docg3.c @@ -325,7 +325,7 @@ static int doc_ecc_bch_fix_data(struct docg3 *docg3, void *buf, u8 *hwecc) for (i = 0; i < DOC_ECC_BCH_SIZE; i++) ecc[i] = bitrev8(hwecc[i]); - numerrs = decode_bch(docg3_bch, NULL, DOC_ECC_BCH_COVERED_BYTES, + numerrs = bch_decode(docg3_bch, NULL, DOC_ECC_BCH_COVERED_BYTES, NULL, ecc, NULL, errorpos); BUG_ON(numerrs == -EINVAL); if (numerrs < 0) @@ -1144,8 +1144,8 @@ static int __init docg3_probe(struct device *dev) base = IOMEM(iores->start); ret = -ENOMEM; - docg3_bch = init_bch(DOC_ECC_BCH_M, DOC_ECC_BCH_T, - DOC_ECC_BCH_PRIMPOLY); + docg3_bch = bch_init(DOC_ECC_BCH_M, DOC_ECC_BCH_T, + DOC_ECC_BCH_PRIMPOLY, false); if (!docg3_bch) goto nomem2; @@ -1181,7 +1181,7 @@ static int __init docg3_probe(struct device *dev) ret = -ENODEV; dev_info(dev, "No supported DiskOnChip found\n"); err_probe: - free_bch(docg3_bch); + bch_free(docg3_bch); nomem2: return ret; } diff --git a/drivers/mtd/nand/nand_bch.c b/drivers/mtd/nand/nand_bch.c index 0d636d9608..45f9c5052a 100644 --- a/drivers/mtd/nand/nand_bch.c +++ b/drivers/mtd/nand/nand_bch.c @@ -42,7 +42,7 @@ int nand_bch_calculate_ecc(struct nand_chip *chip, const unsigned char *buf, unsigned int i; memset(code, 0, chip->ecc.bytes); - encode_bch(nbc->bch, buf, chip->ecc.size, code); + bch_encode(nbc->bch, buf, chip->ecc.size, code); /* apply mask so that an erased page is a valid codeword */ for (i = 0; i < chip->ecc.bytes; i++) @@ -68,7 +68,7 @@ int nand_bch_correct_data(struct nand_chip *chip, unsigned char *buf, unsigned int *errloc = nbc->errloc; int i, count; - count = decode_bch(nbc->bch, NULL, chip->ecc.size, read_ecc, calc_ecc, + count = bch_decode(nbc->bch, NULL, chip->ecc.size, read_ecc, calc_ecc, NULL, errloc); if (count > 0) { for (i = 0; i < count; i++) { @@ -131,7 +131,7 @@ struct nand_bch_control *nand_bch_init(struct mtd_info *mtd) if (!nbc) goto fail; - nbc->bch = init_bch(m, t, 0); + nbc->bch = bch_init(m, t, 0, false); if (!nbc->bch) goto fail; @@ -183,7 +183,7 @@ struct nand_bch_control *nand_bch_init(struct mtd_info *mtd) goto fail; memset(erased_page, 0xff, eccsize); - encode_bch(nbc->bch, erased_page, eccsize, nbc->eccmask); + bch_encode(nbc->bch, erased_page, eccsize, nbc->eccmask); kfree(erased_page); for (i = 0; i < eccbytes; i++) @@ -206,7 +206,7 @@ EXPORT_SYMBOL(nand_bch_init); void nand_bch_free(struct nand_bch_control *nbc) { if (nbc) { - free_bch(nbc->bch); + bch_free(nbc->bch); kfree(nbc->errloc); kfree(nbc->eccmask); kfree(nbc); diff --git a/include/linux/bch.h b/include/linux/bch.h index 295b4ef153..85fdce83d4 100644 --- a/include/linux/bch.h +++ b/include/linux/bch.h @@ -1,19 +1,7 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ /* * Generic binary BCH encoding/decoding library * - * This program is free software; you can redistribute it and/or modify it - * under the terms of the GNU General Public License version 2 as published by - * the Free Software Foundation. - * - * 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., 51 - * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. - * * Copyright © 2011 Parrot S.A. * * Author: Ivan Djelic <ivan.dje...@parrot.com> @@ -45,6 +33,7 @@ * @cache: log-based polynomial representation buffer * @elp: error locator polynomial * @poly_2t: temporary polynomials of degree 2t + * @swap_bits: swap bits within data and syndrome bytes */ struct bch_control { unsigned int m; @@ -63,16 +52,18 @@ struct bch_control { int *cache; struct gf_poly *elp; struct gf_poly *poly_2t[4]; + bool swap_bits; }; -struct bch_control *init_bch(int m, int t, unsigned int prim_poly); +struct bch_control *bch_init(int m, int t, unsigned int prim_poly, + bool swap_bits); -void free_bch(struct bch_control *bch); +void bch_free(struct bch_control *bch); -void encode_bch(struct bch_control *bch, const uint8_t *data, +void bch_encode(struct bch_control *bch, const uint8_t *data, unsigned int len, uint8_t *ecc); -int decode_bch(struct bch_control *bch, const uint8_t *data, unsigned int len, +int bch_decode(struct bch_control *bch, const uint8_t *data, unsigned int len, const uint8_t *recv_ecc, const uint8_t *calc_ecc, const unsigned int *syn, unsigned int *errloc); diff --git a/lib/Kconfig b/lib/Kconfig index 71715ef6e8..df9ba6ccc9 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -86,6 +86,7 @@ config BCH_CONST_PARAMS bool config BCH + select BITREV bool config BITREV diff --git a/lib/bch.c b/lib/bch.c index 5797c3faf8..c4e59eaf37 100644 --- a/lib/bch.c +++ b/lib/bch.c @@ -10,6 +10,10 @@ * 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., 51 + * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * * Copyright © 2011 Parrot S.A. * * Author: Ivan Djelic <ivan.dje...@parrot.com> @@ -19,15 +23,15 @@ * This library provides runtime configurable encoding/decoding of binary * Bose-Chaudhuri-Hocquenghem (BCH) codes. * - * Call init_bch to get a pointer to a newly allocated bch_control structure for + * Call bch_init to get a pointer to a newly allocated bch_control structure for * the given m (Galois field order), t (error correction capability) and * (optional) primitive polynomial parameters. * - * Call encode_bch to compute and store ecc parity bytes to a given buffer. - * Call decode_bch to detect and locate errors in received data. + * Call bch_encode to compute and store ecc parity bytes to a given buffer. + * Call bch_decode to detect and locate errors in received data. * * On systems supporting hw BCH features, intermediate results may be provided - * to decode_bch in order to skip certain steps. See decode_bch() documentation + * to bch_decode in order to skip certain steps. See bch_decode() documentation * for details. * * Option CONFIG_BCH_CONST_PARAMS can be used to force fixed values of @@ -59,16 +63,14 @@ * - WEWoRC 2009, Graz, Austria, LNCS, Springer, July 2009, to appear. * [2] [Zin96] V.A. Zinoviev. On the solution of equations of degree 10 over * finite fields GF(2^q). In Rapport de recherche INRIA no 2829, 1996. - * - * Taken from the linux kernel. */ -#include <common.h> -#include <errno.h> -#include <init.h> -#include <malloc.h> #include <linux/kernel.h> +#include <linux/export.h> +#include <linux/errno.h> +#include <linux/slab.h> #include <linux/bitops.h> +#include <linux/bitrev.h> #include <asm/byteorder.h> #include <linux/bch.h> @@ -76,15 +78,21 @@ #define GF_M(_p) (CONFIG_BCH_CONST_M) #define GF_T(_p) (CONFIG_BCH_CONST_T) #define GF_N(_p) ((1 << (CONFIG_BCH_CONST_M))-1) +#define BCH_MAX_M (CONFIG_BCH_CONST_M) +#define BCH_MAX_T (CONFIG_BCH_CONST_T) #else #define GF_M(_p) ((_p)->m) #define GF_T(_p) ((_p)->t) #define GF_N(_p) ((_p)->n) +#define BCH_MAX_M 15 /* 2KB */ +#define BCH_MAX_T 64 /* 64 bit correction */ #endif #define BCH_ECC_WORDS(_p) DIV_ROUND_UP(GF_M(_p)*GF_T(_p), 32) #define BCH_ECC_BYTES(_p) DIV_ROUND_UP(GF_M(_p)*GF_T(_p), 8) +#define BCH_ECC_MAX_WORDS DIV_ROUND_UP(BCH_MAX_M * BCH_MAX_T, 32) + #ifndef dbg #define dbg(_fmt, args...) do {} while (0) #endif @@ -94,7 +102,7 @@ */ struct gf_poly { unsigned int deg; /* polynomial degree */ - unsigned int c[0]; /* polynomial terms */ + unsigned int c[]; /* polynomial terms */ }; /* given its degree, compute a polynomial size in bytes */ @@ -106,10 +114,18 @@ struct gf_poly_deg1 { unsigned int c[2]; }; +static u8 swap_bits(struct bch_control *bch, u8 in) +{ + if (!bch->swap_bits) + return in; + + return bitrev8(in); +} + /* - * same as encode_bch(), but process input data one byte at a time + * same as bch_encode(), but process input data one byte at a time */ -static void encode_bch_unaligned(struct bch_control *bch, +static void bch_encode_unaligned(struct bch_control *bch, const unsigned char *data, unsigned int len, uint32_t *ecc) { @@ -118,7 +134,9 @@ static void encode_bch_unaligned(struct bch_control *bch, const int l = BCH_ECC_WORDS(bch)-1; while (len--) { - p = bch->mod8_tab + (l+1)*(((ecc[0] >> 24)^(*data++)) & 0xff); + u8 tmp = swap_bits(bch, *data++); + + p = bch->mod8_tab + (l+1)*(((ecc[0] >> 24)^(tmp)) & 0xff); for (i = 0; i < l; i++) ecc[i] = ((ecc[i] << 8)|(ecc[i+1] >> 24))^(*p++); @@ -137,10 +155,16 @@ static void load_ecc8(struct bch_control *bch, uint32_t *dst, unsigned int i, nwords = BCH_ECC_WORDS(bch)-1; for (i = 0; i < nwords; i++, src += 4) - dst[i] = (src[0] << 24)|(src[1] << 16)|(src[2] << 8)|src[3]; + dst[i] = ((u32)swap_bits(bch, src[0]) << 24) | + ((u32)swap_bits(bch, src[1]) << 16) | + ((u32)swap_bits(bch, src[2]) << 8) | + swap_bits(bch, src[3]); memcpy(pad, src, BCH_ECC_BYTES(bch)-4*nwords); - dst[nwords] = (pad[0] << 24)|(pad[1] << 16)|(pad[2] << 8)|pad[3]; + dst[nwords] = ((u32)swap_bits(bch, pad[0]) << 24) | + ((u32)swap_bits(bch, pad[1]) << 16) | + ((u32)swap_bits(bch, pad[2]) << 8) | + swap_bits(bch, pad[3]); } /* @@ -153,20 +177,20 @@ static void store_ecc8(struct bch_control *bch, uint8_t *dst, unsigned int i, nwords = BCH_ECC_WORDS(bch)-1; for (i = 0; i < nwords; i++) { - *dst++ = (src[i] >> 24); - *dst++ = (src[i] >> 16) & 0xff; - *dst++ = (src[i] >> 8) & 0xff; - *dst++ = (src[i] >> 0) & 0xff; + *dst++ = swap_bits(bch, src[i] >> 24); + *dst++ = swap_bits(bch, src[i] >> 16); + *dst++ = swap_bits(bch, src[i] >> 8); + *dst++ = swap_bits(bch, src[i]); } - pad[0] = (src[nwords] >> 24); - pad[1] = (src[nwords] >> 16) & 0xff; - pad[2] = (src[nwords] >> 8) & 0xff; - pad[3] = (src[nwords] >> 0) & 0xff; + pad[0] = swap_bits(bch, src[nwords] >> 24); + pad[1] = swap_bits(bch, src[nwords] >> 16); + pad[2] = swap_bits(bch, src[nwords] >> 8); + pad[3] = swap_bits(bch, src[nwords]); memcpy(dst, pad, BCH_ECC_BYTES(bch)-4*nwords); } /** - * encode_bch - calculate BCH ecc parity of data + * bch_encode - calculate BCH ecc parity of data * @bch: BCH control structure * @data: data to encode * @len: data length in bytes @@ -179,31 +203,35 @@ static void store_ecc8(struct bch_control *bch, uint8_t *dst, * The exact number of computed ecc parity bits is given by member @ecc_bits of * @bch; it may be less than m*t for large values of t. */ -void encode_bch(struct bch_control *bch, const uint8_t *data, +void bch_encode(struct bch_control *bch, const uint8_t *data, unsigned int len, uint8_t *ecc) { const unsigned int l = BCH_ECC_WORDS(bch)-1; unsigned int i, mlen; unsigned long m; - uint32_t w, r[l+1]; + uint32_t w, r[BCH_ECC_MAX_WORDS]; + const size_t r_bytes = BCH_ECC_WORDS(bch) * sizeof(*r); const uint32_t * const tab0 = bch->mod8_tab; const uint32_t * const tab1 = tab0 + 256*(l+1); const uint32_t * const tab2 = tab1 + 256*(l+1); const uint32_t * const tab3 = tab2 + 256*(l+1); const uint32_t *pdata, *p0, *p1, *p2, *p3; + if (WARN_ON(r_bytes > sizeof(r))) + return; + if (ecc) { /* load ecc parity bytes into internal 32-bit buffer */ load_ecc8(bch, bch->ecc_buf, ecc); } else { - memset(bch->ecc_buf, 0, sizeof(r)); + memset(bch->ecc_buf, 0, r_bytes); } /* process first unaligned data bytes */ m = ((unsigned long)data) & 3; if (m) { mlen = (len < (4-m)) ? len : 4-m; - encode_bch_unaligned(bch, data, mlen, bch->ecc_buf); + bch_encode_unaligned(bch, data, mlen, bch->ecc_buf); data += mlen; len -= mlen; } @@ -213,7 +241,7 @@ void encode_bch(struct bch_control *bch, const uint8_t *data, mlen = len/4; data += 4*mlen; len -= 4*mlen; - memcpy(r, bch->ecc_buf, sizeof(r)); + memcpy(r, bch->ecc_buf, r_bytes); /* * split each 32-bit word into 4 polynomials of weight 8 as follows: @@ -228,7 +256,13 @@ void encode_bch(struct bch_control *bch, const uint8_t *data, */ while (mlen--) { /* input data is read in big-endian format */ - w = r[0]^cpu_to_be32(*pdata++); + w = cpu_to_be32(*pdata++); + if (bch->swap_bits) + w = (u32)swap_bits(bch, w) | + ((u32)swap_bits(bch, w >> 8) << 8) | + ((u32)swap_bits(bch, w >> 16) << 16) | + ((u32)swap_bits(bch, w >> 24) << 24); + w ^= r[0]; p0 = tab0 + (l+1)*((w >> 0) & 0xff); p1 = tab1 + (l+1)*((w >> 8) & 0xff); p2 = tab2 + (l+1)*((w >> 16) & 0xff); @@ -239,17 +273,17 @@ void encode_bch(struct bch_control *bch, const uint8_t *data, r[l] = p0[l]^p1[l]^p2[l]^p3[l]; } - memcpy(bch->ecc_buf, r, sizeof(r)); + memcpy(bch->ecc_buf, r, r_bytes); /* process last unaligned bytes */ if (len) - encode_bch_unaligned(bch, data, len, bch->ecc_buf); + bch_encode_unaligned(bch, data, len, bch->ecc_buf); /* store ecc parity bytes into original parity buffer */ if (ecc) store_ecc8(bch, ecc, bch->ecc_buf); } -EXPORT_SYMBOL_GPL(encode_bch); +EXPORT_SYMBOL_GPL(bch_encode); static inline int modulo(struct bch_control *bch, unsigned int v) { @@ -432,7 +466,7 @@ static int solve_linear_system(struct bch_control *bch, unsigned int *rows, { const int m = GF_M(bch); unsigned int tmp, mask; - int rem, c, r, p, k, param[m]; + int rem, c, r, p, k, param[BCH_MAX_M]; k = 0; mask = 1 << m; @@ -515,7 +549,7 @@ static int find_affine4_roots(struct bch_control *bch, unsigned int a, k = a_log(bch, a); rows[0] = c; - /* buid linear system to solve X^4+aX^2+bX+c = 0 */ + /* build linear system to solve X^4+aX^2+bX+c = 0 */ for (i = 0; i < m; i++) { rows[i+1] = bch->a_pow_tab[4*i]^ (a ? bch->a_pow_tab[mod_s(bch, k)] : 0)^ @@ -940,7 +974,7 @@ static int chien_search(struct bch_control *bch, unsigned int len, #endif /* USE_CHIEN_SEARCH */ /** - * decode_bch - decode received codeword and find bit error locations + * bch_decode - decode received codeword and find bit error locations * @bch: BCH control structure * @data: received data, ignored if @calc_ecc is provided * @len: data length in bytes, must always be provided @@ -954,22 +988,22 @@ static int chien_search(struct bch_control *bch, unsigned int len, * invalid parameters were provided * * Depending on the available hw BCH support and the need to compute @calc_ecc - * separately (using encode_bch()), this function should be called with one of + * separately (using bch_encode()), this function should be called with one of * the following parameter configurations - * * by providing @data and @recv_ecc only: - * decode_bch(@bch, @data, @len, @recv_ecc, NULL, NULL, @errloc) + * bch_decode(@bch, @data, @len, @recv_ecc, NULL, NULL, @errloc) * * by providing @recv_ecc and @calc_ecc: - * decode_bch(@bch, NULL, @len, @recv_ecc, @calc_ecc, NULL, @errloc) + * bch_decode(@bch, NULL, @len, @recv_ecc, @calc_ecc, NULL, @errloc) * * by providing ecc = recv_ecc XOR calc_ecc: - * decode_bch(@bch, NULL, @len, NULL, ecc, NULL, @errloc) + * bch_decode(@bch, NULL, @len, NULL, ecc, NULL, @errloc) * * by providing syndrome results @syn: - * decode_bch(@bch, NULL, @len, NULL, NULL, @syn, @errloc) + * bch_decode(@bch, NULL, @len, NULL, NULL, @syn, @errloc) * - * Once decode_bch() has successfully returned with a positive value, error + * Once bch_decode() has successfully returned with a positive value, error * locations returned in array @errloc should be interpreted as follows - * * if (errloc[n] >= 8*len), then n-th error is located in ecc (no need for @@ -981,7 +1015,7 @@ static int chien_search(struct bch_control *bch, unsigned int len, * Note that this function does not perform any data correction by itself, it * merely indicates error locations. */ -int decode_bch(struct bch_control *bch, const uint8_t *data, unsigned int len, +int bch_decode(struct bch_control *bch, const uint8_t *data, unsigned int len, const uint8_t *recv_ecc, const uint8_t *calc_ecc, const unsigned int *syn, unsigned int *errloc) { @@ -1000,7 +1034,7 @@ int decode_bch(struct bch_control *bch, const uint8_t *data, unsigned int len, /* compute received data ecc into an internal buffer */ if (!data || !recv_ecc) return -EINVAL; - encode_bch(bch, data, len, NULL); + bch_encode(bch, data, len, NULL); } else { /* load provided calculated ecc */ load_ecc8(bch, bch->ecc_buf, calc_ecc); @@ -1036,12 +1070,14 @@ int decode_bch(struct bch_control *bch, const uint8_t *data, unsigned int len, break; } errloc[i] = nbits-1-errloc[i]; - errloc[i] = (errloc[i] & ~7)|(7-(errloc[i] & 7)); + if (!bch->swap_bits) + errloc[i] = (errloc[i] & ~7) | + (7-(errloc[i] & 7)); } } return (err >= 0) ? err : -EBADMSG; } -EXPORT_SYMBOL_GPL(decode_bch); +EXPORT_SYMBOL_GPL(bch_decode); /* * generate Galois field lookup tables @@ -1112,7 +1148,7 @@ static int build_deg2_base(struct bch_control *bch) { const int m = GF_M(bch); int i, j, r; - unsigned int sum, x, y, remaining, ak = 0, xi[m]; + unsigned int sum, x, y, remaining, ak = 0, xi[BCH_MAX_M]; /* find k s.t. Tr(a^k) = 1 and 0 <= k < m */ for (i = 0; i < m; i++) { @@ -1224,27 +1260,29 @@ static uint32_t *compute_generator_polynomial(struct bch_control *bch) } /** - * init_bch - initialize a BCH encoder/decoder + * bch_init - initialize a BCH encoder/decoder * @m: Galois field order, should be in the range 5-15 * @t: maximum error correction capability, in bits * @prim_poly: user-provided primitive polynomial (or 0 to use default) + * @swap_bits: swap bits within data and syndrome bytes * * Returns: * a newly allocated BCH control structure if successful, NULL otherwise * * This initialization can take some time, as lookup tables are built for fast * encoding/decoding; make sure not to call this function from a time critical - * path. Usually, init_bch() should be called on module/driver init and - * free_bch() should be called to release memory on exit. + * path. Usually, bch_init() should be called on module/driver init and + * bch_free() should be called to release memory on exit. * * You may provide your own primitive polynomial of degree @m in argument - * @prim_poly, or let init_bch() use its default polynomial. + * @prim_poly, or let bch_init() use its default polynomial. * - * Once init_bch() has successfully returned a pointer to a newly allocated + * Once bch_init() has successfully returned a pointer to a newly allocated * BCH control structure, ecc length in bytes is given by member @ecc_bytes of * the structure. */ -struct bch_control *init_bch(int m, int t, unsigned int prim_poly) +struct bch_control *bch_init(int m, int t, unsigned int prim_poly, + bool swap_bits) { int err = 0; unsigned int i, words; @@ -1252,7 +1290,6 @@ struct bch_control *init_bch(int m, int t, unsigned int prim_poly) struct bch_control *bch = NULL; const int min_m = 5; - const int max_m = 15; /* default primitive polynomials */ static const unsigned int prim_poly_tab[] = { @@ -1268,7 +1305,7 @@ struct bch_control *init_bch(int m, int t, unsigned int prim_poly) goto fail; } #endif - if ((m < min_m) || (m > max_m)) + if ((m < min_m) || (m > BCH_MAX_M)) /* * values of m greater than 15 are not currently supported; * supporting m > 15 would require changing table base type @@ -1276,6 +1313,13 @@ struct bch_control *init_bch(int m, int t, unsigned int prim_poly) */ goto fail; + if (t > BCH_MAX_T) + /* + * we can support larger than 64 bits if necessary, at the + * cost of higher stack usage. + */ + goto fail; + /* sanity checks */ if ((t < 1) || (m*t >= ((1 << m)-1))) /* invalid t value */ @@ -1303,6 +1347,7 @@ struct bch_control *init_bch(int m, int t, unsigned int prim_poly) bch->syn = bch_alloc(2*t*sizeof(*bch->syn), &err); bch->cache = bch_alloc(2*t*sizeof(*bch->cache), &err); bch->elp = bch_alloc((t+1)*sizeof(struct gf_poly_deg1), &err); + bch->swap_bits = swap_bits; for (i = 0; i < ARRAY_SIZE(bch->poly_2t); i++) bch->poly_2t[i] = bch_alloc(GF_POLY_SZ(2*t), &err); @@ -1329,16 +1374,16 @@ struct bch_control *init_bch(int m, int t, unsigned int prim_poly) return bch; fail: - free_bch(bch); + bch_free(bch); return NULL; } -EXPORT_SYMBOL_GPL(init_bch); +EXPORT_SYMBOL_GPL(bch_init); /** - * free_bch - free the BCH control structure + * bch_free - free the BCH control structure * @bch: BCH control structure to release */ -void free_bch(struct bch_control *bch) +void bch_free(struct bch_control *bch) { unsigned int i; @@ -1359,7 +1404,7 @@ void free_bch(struct bch_control *bch) kfree(bch); } } -EXPORT_SYMBOL_GPL(free_bch); +EXPORT_SYMBOL_GPL(bch_free); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Ivan Djelic <ivan.dje...@parrot.com>"); -- 2.39.2
