rslib.h

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/*
 * include/linux/rslib.h
 *
 * Overview:
 *   Generic Reed Solomon encoder / decoder library
 *
 * Copyright (C) 2004 Thomas Gleixner ([email protected])
 *
 * RS code lifted from reed solomon library written by Phil Karn
 * Copyright 2002 Phil Karn, KA9Q
 *
 * $Id: rslib.h,v 1.4 2005/11/07 11:14:52 gleixner Exp $
 *
 * 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.
 */

#ifndef _RSLIB_H_
#define _RSLIB_H_

#include <linux/list.h>

struct rs_control {
    int         mm;
    int         nn;
    uint16_t    *alpha_to;
    uint16_t    *index_of;
    uint16_t    *genpoly;
    int         nroots;
    int         fcr;
    int         prim;
    int         iprim;
    int     gfpoly;
    int     (*gffunc)(int);
    int     users;
    struct list_head list;
};

/* General purpose RS codec, 8-bit data width, symbol width 1-15 bit  */
#ifdef CONFIG_REED_SOLOMON_ENC8
int encode_rs8(struct rs_control *rs, uint8_t *data, int len, uint16_t *par,
           uint16_t invmsk);
#endif
#ifdef CONFIG_REED_SOLOMON_DEC8
int decode_rs8(struct rs_control *rs, uint8_t *data, uint16_t *par, int len,
        uint16_t *s, int no_eras, int *eras_pos, uint16_t invmsk,
           uint16_t *corr);
#endif

/* General purpose RS codec, 16-bit data width, symbol width 1-15 bit  */
#ifdef CONFIG_REED_SOLOMON_ENC16
int encode_rs16(struct rs_control *rs, uint16_t *data, int len, uint16_t *par,
        uint16_t invmsk);
#endif
#ifdef CONFIG_REED_SOLOMON_DEC16
int decode_rs16(struct rs_control *rs, uint16_t *data, uint16_t *par, int len,
        uint16_t *s, int no_eras, int *eras_pos, uint16_t invmsk,
        uint16_t *corr);
#endif

/* Create or get a matching rs control structure */
struct rs_control *init_rs(int symsize, int gfpoly, int fcr, int prim,
               int nroots);
struct rs_control *init_rs_non_canonical(int symsize, int (*func)(int),
                                         int fcr, int prim, int nroots);

/* Release a rs control structure */
void free_rs(struct rs_control *rs);

static inline int rs_modnn(struct rs_control *rs, int x)
{
    while (x >= rs->nn) {
        x -= rs->nn;
        x = (x >> rs->mm) + (x & rs->nn);
    }
    return x;
}

#endif