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- /* SPDX-License-Identifier: GPL-2.0-only */
- /*
- * Generic binary BCH encoding/decoding library
- *
- * Copyright © 2011 Parrot S.A.
- *
- * Author: Ivan Djelic <[email protected]>
- *
- * Description:
- *
- * This library provides runtime configurable encoding/decoding of binary
- * Bose-Chaudhuri-Hocquenghem (BCH) codes.
- */
- #ifndef _BCH_H
- #define _BCH_H
- #include <linux/types.h>
- /**
- * struct bch_control - BCH control structure
- * @m: Galois field order
- * @n: maximum codeword size in bits (= 2^m-1)
- * @t: error correction capability in bits
- * @ecc_bits: ecc exact size in bits, i.e. generator polynomial degree (<=m*t)
- * @ecc_bytes: ecc max size (m*t bits) in bytes
- * @a_pow_tab: Galois field GF(2^m) exponentiation lookup table
- * @a_log_tab: Galois field GF(2^m) log lookup table
- * @mod8_tab: remainder generator polynomial lookup tables
- * @ecc_buf: ecc parity words buffer
- * @ecc_buf2: ecc parity words buffer
- * @xi_tab: GF(2^m) base for solving degree 2 polynomial roots
- * @syn: syndrome buffer
- * @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;
- unsigned int n;
- unsigned int t;
- unsigned int ecc_bits;
- unsigned int ecc_bytes;
- /* private: */
- uint16_t *a_pow_tab;
- uint16_t *a_log_tab;
- uint32_t *mod8_tab;
- uint32_t *ecc_buf;
- uint32_t *ecc_buf2;
- unsigned int *xi_tab;
- unsigned int *syn;
- int *cache;
- struct gf_poly *elp;
- struct gf_poly *poly_2t[4];
- bool swap_bits;
- };
- struct bch_control *bch_init(int m, int t, unsigned int prim_poly,
- bool swap_bits);
- void bch_free(struct bch_control *bch);
- void bch_encode(struct bch_control *bch, const uint8_t *data,
- unsigned int len, uint8_t *ecc);
- 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);
- #endif /* _BCH_H */
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