include: replace linux/module.h with "struct module" wherever possible
[linux-2.6/next.git] / include / linux / rslib.h
blob746580c1939c028d8f8ef8dc6bb460e5ed6dfc17
1 /*
2 * include/linux/rslib.h
4 * Overview:
5 * Generic Reed Solomon encoder / decoder library
7 * Copyright (C) 2004 Thomas Gleixner (tglx@linutronix.de)
9 * RS code lifted from reed solomon library written by Phil Karn
10 * Copyright 2002 Phil Karn, KA9Q
12 * $Id: rslib.h,v 1.4 2005/11/07 11:14:52 gleixner Exp $
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License version 2 as
16 * published by the Free Software Foundation.
19 #ifndef _RSLIB_H_
20 #define _RSLIB_H_
22 #include <linux/list.h>
24 /**
25 * struct rs_control - rs control structure
27 * @mm: Bits per symbol
28 * @nn: Symbols per block (= (1<<mm)-1)
29 * @alpha_to: log lookup table
30 * @index_of: Antilog lookup table
31 * @genpoly: Generator polynomial
32 * @nroots: Number of generator roots = number of parity symbols
33 * @fcr: First consecutive root, index form
34 * @prim: Primitive element, index form
35 * @iprim: prim-th root of 1, index form
36 * @gfpoly: The primitive generator polynominal
37 * @gffunc: Function to generate the field, if non-canonical representation
38 * @users: Users of this structure
39 * @list: List entry for the rs control list
41 struct rs_control {
42 int mm;
43 int nn;
44 uint16_t *alpha_to;
45 uint16_t *index_of;
46 uint16_t *genpoly;
47 int nroots;
48 int fcr;
49 int prim;
50 int iprim;
51 int gfpoly;
52 int (*gffunc)(int);
53 int users;
54 struct list_head list;
57 /* General purpose RS codec, 8-bit data width, symbol width 1-15 bit */
58 #ifdef CONFIG_REED_SOLOMON_ENC8
59 int encode_rs8(struct rs_control *rs, uint8_t *data, int len, uint16_t *par,
60 uint16_t invmsk);
61 #endif
62 #ifdef CONFIG_REED_SOLOMON_DEC8
63 int decode_rs8(struct rs_control *rs, uint8_t *data, uint16_t *par, int len,
64 uint16_t *s, int no_eras, int *eras_pos, uint16_t invmsk,
65 uint16_t *corr);
66 #endif
68 /* General purpose RS codec, 16-bit data width, symbol width 1-15 bit */
69 #ifdef CONFIG_REED_SOLOMON_ENC16
70 int encode_rs16(struct rs_control *rs, uint16_t *data, int len, uint16_t *par,
71 uint16_t invmsk);
72 #endif
73 #ifdef CONFIG_REED_SOLOMON_DEC16
74 int decode_rs16(struct rs_control *rs, uint16_t *data, uint16_t *par, int len,
75 uint16_t *s, int no_eras, int *eras_pos, uint16_t invmsk,
76 uint16_t *corr);
77 #endif
79 /* Create or get a matching rs control structure */
80 struct rs_control *init_rs(int symsize, int gfpoly, int fcr, int prim,
81 int nroots);
82 struct rs_control *init_rs_non_canonical(int symsize, int (*func)(int),
83 int fcr, int prim, int nroots);
85 /* Release a rs control structure */
86 void free_rs(struct rs_control *rs);
88 /** modulo replacement for galois field arithmetics
90 * @rs: the rs control structure
91 * @x: the value to reduce
93 * where
94 * rs->mm = number of bits per symbol
95 * rs->nn = (2^rs->mm) - 1
97 * Simple arithmetic modulo would return a wrong result for values
98 * >= 3 * rs->nn
100 static inline int rs_modnn(struct rs_control *rs, int x)
102 while (x >= rs->nn) {
103 x -= rs->nn;
104 x = (x >> rs->mm) + (x & rs->nn);
106 return x;
109 #endif