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 (<=mt)
@ecc_bytes: ecc max size (mt 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