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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /lib/reed_solomon/encode_rs.c
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 'lib/reed_solomon/encode_rs.c')
-rw-r--r--lib/reed_solomon/encode_rs.c54
1 files changed, 54 insertions, 0 deletions
diff --git a/lib/reed_solomon/encode_rs.c b/lib/reed_solomon/encode_rs.c
new file mode 100644
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+++ b/lib/reed_solomon/encode_rs.c
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1/*
2 * lib/reed_solomon/encode_rs.c
3 *
4 * Overview:
5 * Generic Reed Solomon encoder / decoder library
6 *
7 * Copyright 2002, Phil Karn, KA9Q
8 * May be used under the terms of the GNU General Public License (GPL)
9 *
10 * Adaption to the kernel by Thomas Gleixner (tglx@linutronix.de)
11 *
12 * $Id: encode_rs.c,v 1.4 2004/10/22 15:41:47 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)
19 */
20{
21 int i, j, pad;
22 int nn = rs->nn;
23 int nroots = rs->nroots;
24 uint16_t *alpha_to = rs->alpha_to;
25 uint16_t *index_of = rs->index_of;
26 uint16_t *genpoly = rs->genpoly;
27 uint16_t fb;
28 uint16_t msk = (uint16_t) rs->nn;
29
30 /* Check length parameter for validity */
31 pad = nn - nroots - len;
32 if (pad < 0 || pad >= nn)
33 return -ERANGE;
34
35 for (i = 0; i < len; i++) {
36 fb = index_of[((((uint16_t) data[i])^invmsk) & msk) ^ par[0]];
37 /* feedback term is non-zero */
38 if (fb != nn) {
39 for (j = 1; j < nroots; j++) {
40 par[j] ^= alpha_to[rs_modnn(rs, fb +
41 genpoly[nroots - j])];
42 }
43 }
44 /* Shift */
45 memmove(&par[0], &par[1], sizeof(uint16_t) * (nroots - 1));
46 if (fb != nn) {
47 par[nroots - 1] = alpha_to[rs_modnn(rs,
48 fb + genpoly[0])];
49 } else {
50 par[nroots - 1] = 0;
51 }
52 }
53 return 0;
54}