diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/linux/rslib.h |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'include/linux/rslib.h')
-rw-r--r-- | include/linux/rslib.h | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/include/linux/rslib.h b/include/linux/rslib.h new file mode 100644 index 000000000000..980c8f74d8dc --- /dev/null +++ b/include/linux/rslib.h | |||
@@ -0,0 +1,105 @@ | |||
1 | /* | ||
2 | * include/linux/rslib.h | ||
3 | * | ||
4 | * Overview: | ||
5 | * Generic Reed Solomon encoder / decoder library | ||
6 | * | ||
7 | * Copyright (C) 2004 Thomas Gleixner (tglx@linutronix.de) | ||
8 | * | ||
9 | * RS code lifted from reed solomon library written by Phil Karn | ||
10 | * Copyright 2002 Phil Karn, KA9Q | ||
11 | * | ||
12 | * $Id: rslib.h,v 1.3 2004/10/05 22:08:22 gleixner Exp $ | ||
13 | * | ||
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. | ||
17 | */ | ||
18 | |||
19 | #ifndef _RSLIB_H_ | ||
20 | #define _RSLIB_H_ | ||
21 | |||
22 | #include <linux/list.h> | ||
23 | |||
24 | /** | ||
25 | * struct rs_control - rs control structure | ||
26 | * | ||
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 | * @users: Users of this structure | ||
38 | * @list: List entry for the rs control list | ||
39 | */ | ||
40 | struct rs_control { | ||
41 | int mm; | ||
42 | int nn; | ||
43 | uint16_t *alpha_to; | ||
44 | uint16_t *index_of; | ||
45 | uint16_t *genpoly; | ||
46 | int nroots; | ||
47 | int fcr; | ||
48 | int prim; | ||
49 | int iprim; | ||
50 | int gfpoly; | ||
51 | int users; | ||
52 | struct list_head list; | ||
53 | }; | ||
54 | |||
55 | /* General purpose RS codec, 8-bit data width, symbol width 1-15 bit */ | ||
56 | #ifdef CONFIG_REED_SOLOMON_ENC8 | ||
57 | int encode_rs8(struct rs_control *rs, uint8_t *data, int len, uint16_t *par, | ||
58 | uint16_t invmsk); | ||
59 | #endif | ||
60 | #ifdef CONFIG_REED_SOLOMON_DEC8 | ||
61 | int decode_rs8(struct rs_control *rs, uint8_t *data, uint16_t *par, int len, | ||
62 | uint16_t *s, int no_eras, int *eras_pos, uint16_t invmsk, | ||
63 | uint16_t *corr); | ||
64 | #endif | ||
65 | |||
66 | /* General purpose RS codec, 16-bit data width, symbol width 1-15 bit */ | ||
67 | #ifdef CONFIG_REED_SOLOMON_ENC16 | ||
68 | int encode_rs16(struct rs_control *rs, uint16_t *data, int len, uint16_t *par, | ||
69 | uint16_t invmsk); | ||
70 | #endif | ||
71 | #ifdef CONFIG_REED_SOLOMON_DEC16 | ||
72 | int decode_rs16(struct rs_control *rs, uint16_t *data, uint16_t *par, int len, | ||
73 | uint16_t *s, int no_eras, int *eras_pos, uint16_t invmsk, | ||
74 | uint16_t *corr); | ||
75 | #endif | ||
76 | |||
77 | /* Create or get a matching rs control structure */ | ||
78 | struct rs_control *init_rs(int symsize, int gfpoly, int fcr, int prim, | ||
79 | int nroots); | ||
80 | |||
81 | /* Release a rs control structure */ | ||
82 | void free_rs(struct rs_control *rs); | ||
83 | |||
84 | /** modulo replacement for galois field arithmetics | ||
85 | * | ||
86 | * @rs: the rs control structure | ||
87 | * @x: the value to reduce | ||
88 | * | ||
89 | * where | ||
90 | * rs->mm = number of bits per symbol | ||
91 | * rs->nn = (2^rs->mm) - 1 | ||
92 | * | ||
93 | * Simple arithmetic modulo would return a wrong result for values | ||
94 | * >= 3 * rs->nn | ||
95 | */ | ||
96 | static inline int rs_modnn(struct rs_control *rs, int x) | ||
97 | { | ||
98 | while (x >= rs->nn) { | ||
99 | x -= rs->nn; | ||
100 | x = (x >> rs->mm) + (x & rs->nn); | ||
101 | } | ||
102 | return x; | ||
103 | } | ||
104 | |||
105 | #endif | ||