1 // SPDX-License-Identifier: GPL-2.0 << 2 /* 1 /* 3 * Generic Reed Solomon encoder / decoder libr !! 2 * lib/reed_solomon/encode_rs.c >> 3 * >> 4 * Overview: >> 5 * Generic Reed Solomon encoder / decoder library 4 * 6 * 5 * Copyright 2002, Phil Karn, KA9Q 7 * Copyright 2002, Phil Karn, KA9Q 6 * May be used under the terms of the GNU Gene 8 * May be used under the terms of the GNU General Public License (GPL) 7 * 9 * 8 * Adaption to the kernel by Thomas Gleixner ( 10 * Adaption to the kernel by Thomas Gleixner (tglx@linutronix.de) 9 * 11 * 10 * Generic data width independent code which i !! 12 * $Id: encode_rs.c,v 1.5 2005/11/07 11:14:59 gleixner Exp $ >> 13 * >> 14 */ >> 15 >> 16 /* Generic data width independent code which is included by the >> 17 * wrappers. >> 18 * int encode_rsX (struct rs_control *rs, uintX_t *data, int len, uintY_t *par) 11 */ 19 */ 12 { 20 { 13 struct rs_codec *rs = rsc->codec; << 14 int i, j, pad; 21 int i, j, pad; 15 int nn = rs->nn; 22 int nn = rs->nn; 16 int nroots = rs->nroots; 23 int nroots = rs->nroots; 17 uint16_t *alpha_to = rs->alpha_to; 24 uint16_t *alpha_to = rs->alpha_to; 18 uint16_t *index_of = rs->index_of; 25 uint16_t *index_of = rs->index_of; 19 uint16_t *genpoly = rs->genpoly; 26 uint16_t *genpoly = rs->genpoly; 20 uint16_t fb; 27 uint16_t fb; 21 uint16_t msk = (uint16_t) rs->nn; 28 uint16_t msk = (uint16_t) rs->nn; 22 29 23 /* Check length parameter for validity 30 /* Check length parameter for validity */ 24 pad = nn - nroots - len; 31 pad = nn - nroots - len; 25 if (pad < 0 || pad >= nn) 32 if (pad < 0 || pad >= nn) 26 return -ERANGE; 33 return -ERANGE; 27 34 28 for (i = 0; i < len; i++) { 35 for (i = 0; i < len; i++) { 29 fb = index_of[((((uint16_t) da 36 fb = index_of[((((uint16_t) data[i])^invmsk) & msk) ^ par[0]]; 30 /* feedback term is non-zero * 37 /* feedback term is non-zero */ 31 if (fb != nn) { 38 if (fb != nn) { 32 for (j = 1; j < nroots 39 for (j = 1; j < nroots; j++) { 33 par[j] ^= alph 40 par[j] ^= alpha_to[rs_modnn(rs, fb + 34 41 genpoly[nroots - j])]; 35 } 42 } 36 } 43 } 37 /* Shift */ 44 /* Shift */ 38 memmove(&par[0], &par[1], size 45 memmove(&par[0], &par[1], sizeof(uint16_t) * (nroots - 1)); 39 if (fb != nn) { 46 if (fb != nn) { 40 par[nroots - 1] = alph 47 par[nroots - 1] = alpha_to[rs_modnn(rs, 41 48 fb + genpoly[0])]; 42 } else { 49 } else { 43 par[nroots - 1] = 0; 50 par[nroots - 1] = 0; 44 } 51 } 45 } 52 } 46 return 0; 53 return 0; 47 } 54 } 48 55
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.