// SPDX-License-Identifier: GPL-2.0/* * Generic Reed Solomon encoder / decoder library * * Copyright 2002, Phil Karn, KA9Q * May be used under the terms of the GNU General Public License (GPL) * * Adaption to the kernel by Thomas Gleixner (tglx@kernel.org) * * Generic data width independent code which is included by the wrappers. */{	struct rs_codec *rs = rsc->codec;	int i, j, pad;	int nn = rs->nn;	int nroots = rs->nroots;	uint16_t *alpha_to = rs->alpha_to;	uint16_t *index_of = rs->index_of;	uint16_t *genpoly = rs->genpoly;	uint16_t fb;	uint16_t msk = (uint16_t) rs->nn; 	/* Check length parameter for validity */	pad = nn - nroots - len;	if (pad < 0 || pad >= nn)		return -ERANGE; 	for (i = 0; i < len; i++) {		fb = index_of[((((uint16_t) data[i])^invmsk) & msk) ^ par[0]];		/* feedback term is non-zero */		if (fb != nn) {			for (j = 1; j < nroots; j++) {				par[j] ^= alpha_to[rs_modnn(rs, fb +							 genpoly[nroots - j])];			}		}		/* Shift */		memmove(&par[0], &par[1], sizeof(uint16_t) * (nroots - 1));		if (fb != nn) {			par[nroots - 1] = alpha_to[rs_modnn(rs,							    fb + genpoly[0])];		} else {			par[nroots - 1] = 0;		}	}	return 0;}