-/*
+/*
* include/linux/rslib.h
*
* Overview:
* Generic Reed Solomon encoder / decoder library
- *
+ *
* Copyright (C) 2004 Thomas Gleixner (tglx@linutronix.de)
*
* RS code lifted from reed solomon library written by Phil Karn
* Copyright 2002 Phil Karn, KA9Q
*
- * $Id: rslib.h,v 1.3 2004/10/05 22:08:22 gleixner Exp $
+ * $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
#include <linux/list.h>
-/**
+/**
* struct rs_control - rs control structure
- *
+ *
* @mm: Bits per symbol
* @nn: Symbols per block (= (1<<mm)-1)
* @alpha_to: log lookup table
* @index_of: Antilog lookup table
- * @genpoly: Generator polynomial
+ * @genpoly: Generator polynomial
* @nroots: Number of generator roots = number of parity symbols
* @fcr: First consecutive root, index form
- * @prim: Primitive element, index form
- * @iprim: prim-th root of 1, index form
- * @gfpoly: The primitive generator polynominal
- * @users: Users of this structure
+ * @prim: Primitive element, index form
+ * @iprim: prim-th root of 1, index form
+ * @gfpoly: The primitive generator polynominal
+ * @users: Users of this structure
* @list: List entry for the rs control list
*/
struct rs_control {
uint16_t invmsk);
#endif
#ifdef CONFIG_REED_SOLOMON_DEC8
-int decode_rs8(struct rs_control *rs, uint8_t *data, uint16_t *par, int len,
+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
#endif
/* Create or get a matching rs control structure */
-struct rs_control *init_rs(int symsize, int gfpoly, int fcr, int prim,
+struct rs_control *init_rs(int symsize, int gfpoly, int fcr, int prim,
int nroots);
/* Release a rs control structure */
* @x: the value to reduce
*
* where
- * rs->mm = number of bits per symbol
+ * rs->mm = number of bits per symbol
* rs->nn = (2^rs->mm) - 1
- *
+ *
* Simple arithmetic modulo would return a wrong result for values
* >= 3 * rs->nn
*/
-/*
+/*
* lib/reed_solomon/decode_rs.c
*
* Overview:
* Generic Reed Solomon encoder / decoder library
- *
+ *
* Copyright 2002, Phil Karn, KA9Q
* May be used under the terms of the GNU General Public License (GPL)
*
* Adaption to the kernel by Thomas Gleixner (tglx@linutronix.de)
*
- * $Id: decode_rs.c,v 1.6 2004/10/22 15:41:47 gleixner Exp $
+ * $Id: decode_rs.c,v 1.7 2005/11/07 11:14:59 gleixner Exp $
*
*/
-/* Generic data width independent code which is included by the
+/* Generic data width independent code which is included by the
* wrappers.
*/
-{
+{
int deg_lambda, el, deg_omega;
int i, j, r, k, pad;
int nn = rs->nn;
pad = nn - nroots - len;
if (pad < 0 || pad >= nn)
return -ERANGE;
-
+
/* Does the caller provide the syndrome ? */
- if (s != NULL)
+ if (s != NULL)
goto decode;
/* form the syndromes; i.e., evaluate data(x) at roots of
for (j = 1; j < len; j++) {
for (i = 0; i < nroots; i++) {
if (syn[i] == 0) {
- syn[i] = (((uint16_t) data[j]) ^
+ syn[i] = (((uint16_t) data[j]) ^
invmsk) & msk;
} else {
syn[i] = ((((uint16_t) data[j]) ^
- invmsk) & msk) ^
+ invmsk) & msk) ^
alpha_to[rs_modnn(rs, index_of[syn[i]] +
(fcr + i) * prim)];
}
if (syn[i] == 0) {
syn[i] = ((uint16_t) par[j]) & msk;
} else {
- syn[i] = (((uint16_t) par[j]) & msk) ^
+ syn[i] = (((uint16_t) par[j]) & msk) ^
alpha_to[rs_modnn(rs, index_of[syn[i]] +
(fcr+i)*prim)];
}
if (no_eras > 0) {
/* Init lambda to be the erasure locator polynomial */
- lambda[1] = alpha_to[rs_modnn(rs,
+ lambda[1] = alpha_to[rs_modnn(rs,
prim * (nn - 1 - eras_pos[0]))];
for (i = 1; i < no_eras; i++) {
u = rs_modnn(rs, prim * (nn - 1 - eras_pos[i]));
for (j = i + 1; j > 0; j--) {
tmp = index_of[lambda[j - 1]];
if (tmp != nn) {
- lambda[j] ^=
+ lambda[j] ^=
alpha_to[rs_modnn(rs, u + tmp)];
}
}
discr_r = 0;
for (i = 0; i < r; i++) {
if ((lambda[i] != 0) && (s[r - i - 1] != nn)) {
- discr_r ^=
- alpha_to[rs_modnn(rs,
+ discr_r ^=
+ alpha_to[rs_modnn(rs,
index_of[lambda[i]] +
s[r - i - 1])];
}
t[0] = lambda[0];
for (i = 0; i < nroots; i++) {
if (b[i] != nn) {
- t[i + 1] = lambda[i + 1] ^
+ t[i + 1] = lambda[i + 1] ^
alpha_to[rs_modnn(rs, discr_r +
b[i])];
} else
num1 = 0;
for (i = deg_omega; i >= 0; i--) {
if (omega[i] != nn)
- num1 ^= alpha_to[rs_modnn(rs, omega[i] +
+ num1 ^= alpha_to[rs_modnn(rs, omega[i] +
i * root[j])];
}
num2 = alpha_to[rs_modnn(rs, root[j] * (fcr - 1) + nn)];
* lambda_pr of lambda[i] */
for (i = min(deg_lambda, nroots - 1) & ~1; i >= 0; i -= 2) {
if (lambda[i + 1] != nn) {
- den ^= alpha_to[rs_modnn(rs, lambda[i + 1] +
+ den ^= alpha_to[rs_modnn(rs, lambda[i + 1] +
i * root[j])];
}
}
/* Apply error to data */
if (num1 != 0 && loc[j] >= pad) {
- uint16_t cor = alpha_to[rs_modnn(rs,index_of[num1] +
+ uint16_t cor = alpha_to[rs_modnn(rs,index_of[num1] +
index_of[num2] +
nn - index_of[den])];
/* Store the error correction pattern, if a
-/*
+/*
* lib/reed_solomon/rslib.c
*
* Overview:
* Generic Reed Solomon encoder / decoder library
- *
+ *
* Copyright (C) 2004 Thomas Gleixner (tglx@linutronix.de)
*
* Reed Solomon code lifted from reed solomon library written by Phil Karn
* Copyright 2002 Phil Karn, KA9Q
*
- * $Id: rslib.c,v 1.5 2004/10/22 15:41:47 gleixner Exp $
+ * $Id: rslib.c,v 1.7 2005/11/07 11:14:59 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.
*
* Description:
- *
+ *
* The generic Reed Solomon library provides runtime configurable
* encoding / decoding of RS codes.
* Each user must call init_rs to get a pointer to a rs_control
* If a structure is generated then the polynomial arrays for
* fast encoding / decoding are built. This can take some time so
* make sure not to call this function from a time critical path.
- * Usually a module / driver should initialize the necessary
+ * Usually a module / driver should initialize the necessary
* rs_control structure on module / driver init and release it
* on exit.
- * The encoding puts the calculated syndrome into a given syndrome
- * buffer.
+ * The encoding puts the calculated syndrome into a given syndrome
+ * buffer.
* The decoding is a two step process. The first step calculates
* the syndrome over the received (data + syndrome) and calls the
* second stage, which does the decoding / error correction itself.
/* Protection for the list */
static DECLARE_MUTEX(rslistlock);
-/**
+/**
* rs_init - Initialize a Reed-Solomon codec
*
* @symsize: symbol size, bits (1-8)
* Allocate a control structure and the polynom arrays for faster
* en/decoding. Fill the arrays according to the given parameters
*/
-static struct rs_control *rs_init(int symsize, int gfpoly, int fcr,
+static struct rs_control *rs_init(int symsize, int gfpoly, int fcr,
int prim, int nroots)
{
struct rs_control *rs;
/* Multiply rs->genpoly[] by @**(root + x) */
for (j = i; j > 0; j--) {
if (rs->genpoly[j] != 0) {
- rs->genpoly[j] = rs->genpoly[j -1] ^
- rs->alpha_to[rs_modnn(rs,
+ rs->genpoly[j] = rs->genpoly[j -1] ^
+ rs->alpha_to[rs_modnn(rs,
rs->index_of[rs->genpoly[j]] + root)];
} else
rs->genpoly[j] = rs->genpoly[j - 1];
}
/* rs->genpoly[0] can never be zero */
- rs->genpoly[0] =
- rs->alpha_to[rs_modnn(rs,
+ rs->genpoly[0] =
+ rs->alpha_to[rs_modnn(rs,
rs->index_of[rs->genpoly[0]] + root)];
}
/* convert rs->genpoly[] to index form for quicker encoding */
}
-/**
+/**
* free_rs - Free the rs control structure, if its not longer used
*
* @rs: the control structure which is not longer used by the
up(&rslistlock);
}
-/**
+/**
* init_rs - Find a matching or allocate a new rs control structure
*
* @symsize: the symbol size (number of bits)
* @gfpoly: the extended Galois field generator polynomial coefficients,
* with the 0th coefficient in the low order bit. The polynomial
* must be primitive;
- * @fcr: the first consecutive root of the rs code generator polynomial
+ * @fcr: the first consecutive root of the rs code generator polynomial
* in index form
* @prim: primitive element to generate polynomial roots
* @nroots: RS code generator polynomial degree (number of roots)
*/
-struct rs_control *init_rs(int symsize, int gfpoly, int fcr, int prim,
+struct rs_control *init_rs(int symsize, int gfpoly, int fcr, int prim,
int nroots)
{
struct list_head *tmp;
return NULL;
if (prim <= 0 || prim >= (1<<symsize))
return NULL;
- if (nroots < 0 || nroots >= (1<<symsize) || nroots > 8)
+ if (nroots < 0 || nroots >= (1<<symsize))
return NULL;
-
+
down(&rslistlock);
/* Walk through the list and look for a matching entry */
if (gfpoly != rs->gfpoly)
continue;
if (fcr != rs->fcr)
- continue;
+ continue;
if (prim != rs->prim)
- continue;
+ continue;
if (nroots != rs->nroots)
continue;
/* We have a matching one already */
rs->users = 1;
list_add(&rs->list, &rslist);
}
-out:
+out:
up(&rslistlock);
return rs;
}
#ifdef CONFIG_REED_SOLOMON_ENC8
-/**
+/**
* encode_rs8 - Calculate the parity for data values (8bit data width)
*
* @rs: the rs control structure
* @data: data field of a given type
- * @len: data length
+ * @len: data length
* @par: parity data, must be initialized by caller (usually all 0)
* @invmsk: invert data mask (will be xored on data)
*
* symbol size > 8. The calling code must take care of encoding of the
* syndrome result for storage itself.
*/
-int encode_rs8(struct rs_control *rs, uint8_t *data, int len, uint16_t *par,
+int encode_rs8(struct rs_control *rs, uint8_t *data, int len, uint16_t *par,
uint16_t invmsk)
{
#include "encode_rs.c"
#endif
#ifdef CONFIG_REED_SOLOMON_DEC8
-/**
+/**
* decode_rs8 - Decode codeword (8bit data width)
*
* @rs: the rs control structure
* syndrome result and the received parity before calling this code.
*/
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 *s, int no_eras, int *eras_pos, uint16_t invmsk,
uint16_t *corr)
{
#include "decode_rs.c"
*
* @rs: the rs control structure
* @data: data field of a given type
- * @len: data length
+ * @len: data length
* @par: parity data, must be initialized by caller (usually all 0)
* @invmsk: invert data mask (will be xored on data, not on parity!)
*
* Each field in the data array contains up to symbol size bits of valid data.
*/
-int encode_rs16(struct rs_control *rs, uint16_t *data, int len, uint16_t *par,
+int encode_rs16(struct rs_control *rs, uint16_t *data, int len, uint16_t *par,
uint16_t invmsk)
{
#include "encode_rs.c"
#endif
#ifdef CONFIG_REED_SOLOMON_DEC16
-/**
+/**
* decode_rs16 - Decode codeword (16bit data width)
*
* @rs: the rs control structure
* @s: syndrome data field (if NULL, syndrome is calculated)
* @no_eras: number of erasures
* @eras_pos: position of erasures, can be NULL
- * @invmsk: invert data mask (will be xored on data, not on parity!)
+ * @invmsk: invert data mask (will be xored on data, not on parity!)
* @corr: buffer to store correction bitmask on eras_pos
*
* Each field in the data array contains up to symbol size bits of valid data.
*/
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 *s, int no_eras, int *eras_pos, uint16_t invmsk,
uint16_t *corr)
{
#include "decode_rs.c"
git.openpandora.org / pandora-kernel.git / commitdiff