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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
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')
-rw-r--r--lib/reed_solomon/Makefile6
-rw-r--r--lib/reed_solomon/decode_rs.c272
-rw-r--r--lib/reed_solomon/encode_rs.c54
-rw-r--r--lib/reed_solomon/reed_solomon.c335
4 files changed, 667 insertions, 0 deletions
diff --git a/lib/reed_solomon/Makefile b/lib/reed_solomon/Makefile
new file mode 100644
index 000000000000..747a2de29346
--- /dev/null
+++ b/lib/reed_solomon/Makefile
@@ -0,0 +1,6 @@
1#
2# This is a modified version of reed solomon lib,
3#
4
5obj-$(CONFIG_REED_SOLOMON) += reed_solomon.o
6
diff --git a/lib/reed_solomon/decode_rs.c b/lib/reed_solomon/decode_rs.c
new file mode 100644
index 000000000000..d401decd6289
--- /dev/null
+++ b/lib/reed_solomon/decode_rs.c
@@ -0,0 +1,272 @@
1/*
2 * lib/reed_solomon/decode_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: decode_rs.c,v 1.6 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 */
19{
20 int deg_lambda, el, deg_omega;
21 int i, j, r, k, pad;
22 int nn = rs->nn;
23 int nroots = rs->nroots;
24 int fcr = rs->fcr;
25 int prim = rs->prim;
26 int iprim = rs->iprim;
27 uint16_t *alpha_to = rs->alpha_to;
28 uint16_t *index_of = rs->index_of;
29 uint16_t u, q, tmp, num1, num2, den, discr_r, syn_error;
30 /* Err+Eras Locator poly and syndrome poly The maximum value
31 * of nroots is 8. So the necessary stack size will be about
32 * 220 bytes max.
33 */
34 uint16_t lambda[nroots + 1], syn[nroots];
35 uint16_t b[nroots + 1], t[nroots + 1], omega[nroots + 1];
36 uint16_t root[nroots], reg[nroots + 1], loc[nroots];
37 int count = 0;
38 uint16_t msk = (uint16_t) rs->nn;
39
40 /* Check length parameter for validity */
41 pad = nn - nroots - len;
42 if (pad < 0 || pad >= nn)
43 return -ERANGE;
44
45 /* Does the caller provide the syndrome ? */
46 if (s != NULL)
47 goto decode;
48
49 /* form the syndromes; i.e., evaluate data(x) at roots of
50 * g(x) */
51 for (i = 0; i < nroots; i++)
52 syn[i] = (((uint16_t) data[0]) ^ invmsk) & msk;
53
54 for (j = 1; j < len; j++) {
55 for (i = 0; i < nroots; i++) {
56 if (syn[i] == 0) {
57 syn[i] = (((uint16_t) data[j]) ^
58 invmsk) & msk;
59 } else {
60 syn[i] = ((((uint16_t) data[j]) ^
61 invmsk) & msk) ^
62 alpha_to[rs_modnn(rs, index_of[syn[i]] +
63 (fcr + i) * prim)];
64 }
65 }
66 }
67
68 for (j = 0; j < nroots; j++) {
69 for (i = 0; i < nroots; i++) {
70 if (syn[i] == 0) {
71 syn[i] = ((uint16_t) par[j]) & msk;
72 } else {
73 syn[i] = (((uint16_t) par[j]) & msk) ^
74 alpha_to[rs_modnn(rs, index_of[syn[i]] +
75 (fcr+i)*prim)];
76 }
77 }
78 }
79 s = syn;
80
81 /* Convert syndromes to index form, checking for nonzero condition */
82 syn_error = 0;
83 for (i = 0; i < nroots; i++) {
84 syn_error |= s[i];
85 s[i] = index_of[s[i]];
86 }
87
88 if (!syn_error) {
89 /* if syndrome is zero, data[] is a codeword and there are no
90 * errors to correct. So return data[] unmodified
91 */
92 count = 0;
93 goto finish;
94 }
95
96 decode:
97 memset(&lambda[1], 0, nroots * sizeof(lambda[0]));
98 lambda[0] = 1;
99
100 if (no_eras > 0) {
101 /* Init lambda to be the erasure locator polynomial */
102 lambda[1] = alpha_to[rs_modnn(rs,
103 prim * (nn - 1 - eras_pos[0]))];
104 for (i = 1; i < no_eras; i++) {
105 u = rs_modnn(rs, prim * (nn - 1 - eras_pos[i]));
106 for (j = i + 1; j > 0; j--) {
107 tmp = index_of[lambda[j - 1]];
108 if (tmp != nn) {
109 lambda[j] ^=
110 alpha_to[rs_modnn(rs, u + tmp)];
111 }
112 }
113 }
114 }
115
116 for (i = 0; i < nroots + 1; i++)
117 b[i] = index_of[lambda[i]];
118
119 /*
120 * Begin Berlekamp-Massey algorithm to determine error+erasure
121 * locator polynomial
122 */
123 r = no_eras;
124 el = no_eras;
125 while (++r <= nroots) { /* r is the step number */
126 /* Compute discrepancy at the r-th step in poly-form */
127 discr_r = 0;
128 for (i = 0; i < r; i++) {
129 if ((lambda[i] != 0) && (s[r - i - 1] != nn)) {
130 discr_r ^=
131 alpha_to[rs_modnn(rs,
132 index_of[lambda[i]] +
133 s[r - i - 1])];
134 }
135 }
136 discr_r = index_of[discr_r]; /* Index form */
137 if (discr_r == nn) {
138 /* 2 lines below: B(x) <-- x*B(x) */
139 memmove (&b[1], b, nroots * sizeof (b[0]));
140 b[0] = nn;
141 } else {
142 /* 7 lines below: T(x) <-- lambda(x)-discr_r*x*b(x) */
143 t[0] = lambda[0];
144 for (i = 0; i < nroots; i++) {
145 if (b[i] != nn) {
146 t[i + 1] = lambda[i + 1] ^
147 alpha_to[rs_modnn(rs, discr_r +
148 b[i])];
149 } else
150 t[i + 1] = lambda[i + 1];
151 }
152 if (2 * el <= r + no_eras - 1) {
153 el = r + no_eras - el;
154 /*
155 * 2 lines below: B(x) <-- inv(discr_r) *
156 * lambda(x)
157 */
158 for (i = 0; i <= nroots; i++) {
159 b[i] = (lambda[i] == 0) ? nn :
160 rs_modnn(rs, index_of[lambda[i]]
161 - discr_r + nn);
162 }
163 } else {
164 /* 2 lines below: B(x) <-- x*B(x) */
165 memmove(&b[1], b, nroots * sizeof(b[0]));
166 b[0] = nn;
167 }
168 memcpy(lambda, t, (nroots + 1) * sizeof(t[0]));
169 }
170 }
171
172 /* Convert lambda to index form and compute deg(lambda(x)) */
173 deg_lambda = 0;
174 for (i = 0; i < nroots + 1; i++) {
175 lambda[i] = index_of[lambda[i]];
176 if (lambda[i] != nn)
177 deg_lambda = i;
178 }
179 /* Find roots of error+erasure locator polynomial by Chien search */
180 memcpy(&reg[1], &lambda[1], nroots * sizeof(reg[0]));
181 count = 0; /* Number of roots of lambda(x) */
182 for (i = 1, k = iprim - 1; i <= nn; i++, k = rs_modnn(rs, k + iprim)) {
183 q = 1; /* lambda[0] is always 0 */
184 for (j = deg_lambda; j > 0; j--) {
185 if (reg[j] != nn) {
186 reg[j] = rs_modnn(rs, reg[j] + j);
187 q ^= alpha_to[reg[j]];
188 }
189 }
190 if (q != 0)
191 continue; /* Not a root */
192 /* store root (index-form) and error location number */
193 root[count] = i;
194 loc[count] = k;
195 /* If we've already found max possible roots,
196 * abort the search to save time
197 */
198 if (++count == deg_lambda)
199 break;
200 }
201 if (deg_lambda != count) {
202 /*
203 * deg(lambda) unequal to number of roots => uncorrectable
204 * error detected
205 */
206 count = -1;
207 goto finish;
208 }
209 /*
210 * Compute err+eras evaluator poly omega(x) = s(x)*lambda(x) (modulo
211 * x**nroots). in index form. Also find deg(omega).
212 */
213 deg_omega = deg_lambda - 1;
214 for (i = 0; i <= deg_omega; i++) {
215 tmp = 0;
216 for (j = i; j >= 0; j--) {
217 if ((s[i - j] != nn) && (lambda[j] != nn))
218 tmp ^=
219 alpha_to[rs_modnn(rs, s[i - j] + lambda[j])];
220 }
221 omega[i] = index_of[tmp];
222 }
223
224 /*
225 * Compute error values in poly-form. num1 = omega(inv(X(l))), num2 =
226 * inv(X(l))**(fcr-1) and den = lambda_pr(inv(X(l))) all in poly-form
227 */
228 for (j = count - 1; j >= 0; j--) {
229 num1 = 0;
230 for (i = deg_omega; i >= 0; i--) {
231 if (omega[i] != nn)
232 num1 ^= alpha_to[rs_modnn(rs, omega[i] +
233 i * root[j])];
234 }
235 num2 = alpha_to[rs_modnn(rs, root[j] * (fcr - 1) + nn)];
236 den = 0;
237
238 /* lambda[i+1] for i even is the formal derivative
239 * lambda_pr of lambda[i] */
240 for (i = min(deg_lambda, nroots - 1) & ~1; i >= 0; i -= 2) {
241 if (lambda[i + 1] != nn) {
242 den ^= alpha_to[rs_modnn(rs, lambda[i + 1] +
243 i * root[j])];
244 }
245 }
246 /* Apply error to data */
247 if (num1 != 0 && loc[j] >= pad) {
248 uint16_t cor = alpha_to[rs_modnn(rs,index_of[num1] +
249 index_of[num2] +
250 nn - index_of[den])];
251 /* Store the error correction pattern, if a
252 * correction buffer is available */
253 if (corr) {
254 corr[j] = cor;
255 } else {
256 /* If a data buffer is given and the
257 * error is inside the message,
258 * correct it */
259 if (data && (loc[j] < (nn - nroots)))
260 data[loc[j] - pad] ^= cor;
261 }
262 }
263 }
264
265finish:
266 if (eras_pos != NULL) {
267 for (i = 0; i < count; i++)
268 eras_pos[i] = loc[i] - pad;
269 }
270 return count;
271
272}
diff --git a/lib/reed_solomon/encode_rs.c b/lib/reed_solomon/encode_rs.c
new file mode 100644
index 000000000000..237bf65ae886
--- /dev/null
+++ b/lib/reed_solomon/encode_rs.c
@@ -0,0 +1,54 @@
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}
diff --git a/lib/reed_solomon/reed_solomon.c b/lib/reed_solomon/reed_solomon.c
new file mode 100644
index 000000000000..6604e3b1940c
--- /dev/null
+++ b/lib/reed_solomon/reed_solomon.c
@@ -0,0 +1,335 @@
1/*
2 * lib/reed_solomon/rslib.c
3 *
4 * Overview:
5 * Generic Reed Solomon encoder / decoder library
6 *
7 * Copyright (C) 2004 Thomas Gleixner (tglx@linutronix.de)
8 *
9 * Reed Solomon code lifted from reed solomon library written by Phil Karn
10 * Copyright 2002 Phil Karn, KA9Q
11 *
12 * $Id: rslib.c,v 1.5 2004/10/22 15:41:47 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 * Description:
19 *
20 * The generic Reed Solomon library provides runtime configurable
21 * encoding / decoding of RS codes.
22 * Each user must call init_rs to get a pointer to a rs_control
23 * structure for the given rs parameters. This structure is either
24 * generated or a already available matching control structure is used.
25 * If a structure is generated then the polynomial arrays for
26 * fast encoding / decoding are built. This can take some time so
27 * make sure not to call this function from a time critical path.
28 * Usually a module / driver should initialize the necessary
29 * rs_control structure on module / driver init and release it
30 * on exit.
31 * The encoding puts the calculated syndrome into a given syndrome
32 * buffer.
33 * The decoding is a two step process. The first step calculates
34 * the syndrome over the received (data + syndrome) and calls the
35 * second stage, which does the decoding / error correction itself.
36 * Many hw encoders provide a syndrome calculation over the received
37 * data + syndrome and can call the second stage directly.
38 *
39 */
40
41#include <linux/errno.h>
42#include <linux/kernel.h>
43#include <linux/init.h>
44#include <linux/module.h>
45#include <linux/rslib.h>
46#include <linux/slab.h>
47#include <asm/semaphore.h>
48
49/* This list holds all currently allocated rs control structures */
50static LIST_HEAD (rslist);
51/* Protection for the list */
52static DECLARE_MUTEX(rslistlock);
53
54/**
55 * rs_init - Initialize a Reed-Solomon codec
56 *
57 * @symsize: symbol size, bits (1-8)
58 * @gfpoly: Field generator polynomial coefficients
59 * @fcr: first root of RS code generator polynomial, index form
60 * @prim: primitive element to generate polynomial roots
61 * @nroots: RS code generator polynomial degree (number of roots)
62 *
63 * Allocate a control structure and the polynom arrays for faster
64 * en/decoding. Fill the arrays according to the given parameters
65 */
66static struct rs_control *rs_init(int symsize, int gfpoly, int fcr,
67 int prim, int nroots)
68{
69 struct rs_control *rs;
70 int i, j, sr, root, iprim;
71
72 /* Allocate the control structure */
73 rs = kmalloc(sizeof (struct rs_control), GFP_KERNEL);
74 if (rs == NULL)
75 return NULL;
76
77 INIT_LIST_HEAD(&rs->list);
78
79 rs->mm = symsize;
80 rs->nn = (1 << symsize) - 1;
81 rs->fcr = fcr;
82 rs->prim = prim;
83 rs->nroots = nroots;
84 rs->gfpoly = gfpoly;
85
86 /* Allocate the arrays */
87 rs->alpha_to = kmalloc(sizeof(uint16_t) * (rs->nn + 1), GFP_KERNEL);
88 if (rs->alpha_to == NULL)
89 goto errrs;
90
91 rs->index_of = kmalloc(sizeof(uint16_t) * (rs->nn + 1), GFP_KERNEL);
92 if (rs->index_of == NULL)
93 goto erralp;
94
95 rs->genpoly = kmalloc(sizeof(uint16_t) * (rs->nroots + 1), GFP_KERNEL);
96 if(rs->genpoly == NULL)
97 goto erridx;
98
99 /* Generate Galois field lookup tables */
100 rs->index_of[0] = rs->nn; /* log(zero) = -inf */
101 rs->alpha_to[rs->nn] = 0; /* alpha**-inf = 0 */
102 sr = 1;
103 for (i = 0; i < rs->nn; i++) {
104 rs->index_of[sr] = i;
105 rs->alpha_to[i] = sr;
106 sr <<= 1;
107 if (sr & (1 << symsize))
108 sr ^= gfpoly;
109 sr &= rs->nn;
110 }
111 /* If it's not primitive, exit */
112 if(sr != 1)
113 goto errpol;
114
115 /* Find prim-th root of 1, used in decoding */
116 for(iprim = 1; (iprim % prim) != 0; iprim += rs->nn);
117 /* prim-th root of 1, index form */
118 rs->iprim = iprim / prim;
119
120 /* Form RS code generator polynomial from its roots */
121 rs->genpoly[0] = 1;
122 for (i = 0, root = fcr * prim; i < nroots; i++, root += prim) {
123 rs->genpoly[i + 1] = 1;
124 /* Multiply rs->genpoly[] by @**(root + x) */
125 for (j = i; j > 0; j--) {
126 if (rs->genpoly[j] != 0) {
127 rs->genpoly[j] = rs->genpoly[j -1] ^
128 rs->alpha_to[rs_modnn(rs,
129 rs->index_of[rs->genpoly[j]] + root)];
130 } else
131 rs->genpoly[j] = rs->genpoly[j - 1];
132 }
133 /* rs->genpoly[0] can never be zero */
134 rs->genpoly[0] =
135 rs->alpha_to[rs_modnn(rs,
136 rs->index_of[rs->genpoly[0]] + root)];
137 }
138 /* convert rs->genpoly[] to index form for quicker encoding */
139 for (i = 0; i <= nroots; i++)
140 rs->genpoly[i] = rs->index_of[rs->genpoly[i]];
141 return rs;
142
143 /* Error exit */
144errpol:
145 kfree(rs->genpoly);
146erridx:
147 kfree(rs->index_of);
148erralp:
149 kfree(rs->alpha_to);
150errrs:
151 kfree(rs);
152 return NULL;
153}
154
155
156/**
157 * free_rs - Free the rs control structure, if its not longer used
158 *
159 * @rs: the control structure which is not longer used by the
160 * caller
161 */
162void free_rs(struct rs_control *rs)
163{
164 down(&rslistlock);
165 rs->users--;
166 if(!rs->users) {
167 list_del(&rs->list);
168 kfree(rs->alpha_to);
169 kfree(rs->index_of);
170 kfree(rs->genpoly);
171 kfree(rs);
172 }
173 up(&rslistlock);
174}
175
176/**
177 * init_rs - Find a matching or allocate a new rs control structure
178 *
179 * @symsize: the symbol size (number of bits)
180 * @gfpoly: the extended Galois field generator polynomial coefficients,
181 * with the 0th coefficient in the low order bit. The polynomial
182 * must be primitive;
183 * @fcr: the first consecutive root of the rs code generator polynomial
184 * in index form
185 * @prim: primitive element to generate polynomial roots
186 * @nroots: RS code generator polynomial degree (number of roots)
187 */
188struct rs_control *init_rs(int symsize, int gfpoly, int fcr, int prim,
189 int nroots)
190{
191 struct list_head *tmp;
192 struct rs_control *rs;
193
194 /* Sanity checks */
195 if (symsize < 1)
196 return NULL;
197 if (fcr < 0 || fcr >= (1<<symsize))
198 return NULL;
199 if (prim <= 0 || prim >= (1<<symsize))
200 return NULL;
201 if (nroots < 0 || nroots >= (1<<symsize) || nroots > 8)
202 return NULL;
203
204 down(&rslistlock);
205
206 /* Walk through the list and look for a matching entry */
207 list_for_each(tmp, &rslist) {
208 rs = list_entry(tmp, struct rs_control, list);
209 if (symsize != rs->mm)
210 continue;
211 if (gfpoly != rs->gfpoly)
212 continue;
213 if (fcr != rs->fcr)
214 continue;
215 if (prim != rs->prim)
216 continue;
217 if (nroots != rs->nroots)
218 continue;
219 /* We have a matching one already */
220 rs->users++;
221 goto out;
222 }
223
224 /* Create a new one */
225 rs = rs_init(symsize, gfpoly, fcr, prim, nroots);
226 if (rs) {
227 rs->users = 1;
228 list_add(&rs->list, &rslist);
229 }
230out:
231 up(&rslistlock);
232 return rs;
233}
234
235#ifdef CONFIG_REED_SOLOMON_ENC8
236/**
237 * encode_rs8 - Calculate the parity for data values (8bit data width)
238 *
239 * @rs: the rs control structure
240 * @data: data field of a given type
241 * @len: data length
242 * @par: parity data, must be initialized by caller (usually all 0)
243 * @invmsk: invert data mask (will be xored on data)
244 *
245 * The parity uses a uint16_t data type to enable
246 * symbol size > 8. The calling code must take care of encoding of the
247 * syndrome result for storage itself.
248 */
249int encode_rs8(struct rs_control *rs, uint8_t *data, int len, uint16_t *par,
250 uint16_t invmsk)
251{
252#include "encode_rs.c"
253}
254EXPORT_SYMBOL_GPL(encode_rs8);
255#endif
256
257#ifdef CONFIG_REED_SOLOMON_DEC8
258/**
259 * decode_rs8 - Decode codeword (8bit data width)
260 *
261 * @rs: the rs control structure
262 * @data: data field of a given type
263 * @par: received parity data field
264 * @len: data length
265 * @s: syndrome data field (if NULL, syndrome is calculated)
266 * @no_eras: number of erasures
267 * @eras_pos: position of erasures, can be NULL
268 * @invmsk: invert data mask (will be xored on data, not on parity!)
269 * @corr: buffer to store correction bitmask on eras_pos
270 *
271 * The syndrome and parity uses a uint16_t data type to enable
272 * symbol size > 8. The calling code must take care of decoding of the
273 * syndrome result and the received parity before calling this code.
274 */
275int decode_rs8(struct rs_control *rs, uint8_t *data, uint16_t *par, int len,
276 uint16_t *s, int no_eras, int *eras_pos, uint16_t invmsk,
277 uint16_t *corr)
278{
279#include "decode_rs.c"
280}
281EXPORT_SYMBOL_GPL(decode_rs8);
282#endif
283
284#ifdef CONFIG_REED_SOLOMON_ENC16
285/**
286 * encode_rs16 - Calculate the parity for data values (16bit data width)
287 *
288 * @rs: the rs control structure
289 * @data: data field of a given type
290 * @len: data length
291 * @par: parity data, must be initialized by caller (usually all 0)
292 * @invmsk: invert data mask (will be xored on data, not on parity!)
293 *
294 * Each field in the data array contains up to symbol size bits of valid data.
295 */
296int encode_rs16(struct rs_control *rs, uint16_t *data, int len, uint16_t *par,
297 uint16_t invmsk)
298{
299#include "encode_rs.c"
300}
301EXPORT_SYMBOL_GPL(encode_rs16);
302#endif
303
304#ifdef CONFIG_REED_SOLOMON_DEC16
305/**
306 * decode_rs16 - Decode codeword (16bit data width)
307 *
308 * @rs: the rs control structure
309 * @data: data field of a given type
310 * @par: received parity data field
311 * @len: data length
312 * @s: syndrome data field (if NULL, syndrome is calculated)
313 * @no_eras: number of erasures
314 * @eras_pos: position of erasures, can be NULL
315 * @invmsk: invert data mask (will be xored on data, not on parity!)
316 * @corr: buffer to store correction bitmask on eras_pos
317 *
318 * Each field in the data array contains up to symbol size bits of valid data.
319 */
320int decode_rs16(struct rs_control *rs, uint16_t *data, uint16_t *par, int len,
321 uint16_t *s, int no_eras, int *eras_pos, uint16_t invmsk,
322 uint16_t *corr)
323{
324#include "decode_rs.c"
325}
326EXPORT_SYMBOL_GPL(decode_rs16);
327#endif
328
329EXPORT_SYMBOL_GPL(init_rs);
330EXPORT_SYMBOL_GPL(free_rs);
331
332MODULE_LICENSE("GPL");
333MODULE_DESCRIPTION("Reed Solomon encoder/decoder");
334MODULE_AUTHOR("Phil Karn, Thomas Gleixner");
335