[net-next-2.6.git] / lib / reed_solomon / reed_solomon.c

/*
 * 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 1.7 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
 * structure for the given rs parameters. This structure is either
 * generated or a already available matching control structure is used.
 * 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
 * rs_control structure on module / driver init and release it
 * on exit.
 * 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.
 * Many hw encoders provide a syndrome calculation over the received
 * data + syndrome and can call the second stage directly.
 *
 */

#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/rslib.h>
#include <linux/slab.h>
#include <linux/mutex.h>
#include <asm/semaphore.h>

/* This list holds all currently allocated rs control structures */
static LIST_HEAD (rslist);
/* Protection for the list */
static DEFINE_MUTEX(rslistlock);

/**
 * rs_init - Initialize a Reed-Solomon codec
 * @symsize:	symbol size, bits (1-8)
 * @gfpoly:	Field generator polynomial coefficients
 * @fcr:	first root of RS code generator polynomial, index form
 * @prim:	primitive element to generate polynomial roots
 * @nroots:	RS code generator polynomial degree (number of roots)
 *
 * 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,
				   int prim, int nroots)
{
	struct rs_control *rs;
	int i, j, sr, root, iprim;

	/* Allocate the control structure */
	rs = kmalloc(sizeof (struct rs_control), GFP_KERNEL);
	if (rs == NULL)
		return NULL;

	INIT_LIST_HEAD(&rs->list);

	rs->mm = symsize;
	rs->nn = (1 << symsize) - 1;
	rs->fcr = fcr;
	rs->prim = prim;
	rs->nroots = nroots;
	rs->gfpoly = gfpoly;

	/* Allocate the arrays */
	rs->alpha_to = kmalloc(sizeof(uint16_t) * (rs->nn + 1), GFP_KERNEL);
	if (rs->alpha_to == NULL)
		goto errrs;

	rs->index_of = kmalloc(sizeof(uint16_t) * (rs->nn + 1), GFP_KERNEL);
	if (rs->index_of == NULL)
		goto erralp;

	rs->genpoly = kmalloc(sizeof(uint16_t) * (rs->nroots + 1), GFP_KERNEL);
	if(rs->genpoly == NULL)
		goto erridx;

	/* Generate Galois field lookup tables */
	rs->index_of[0] = rs->nn;	/* log(zero) = -inf */
	rs->alpha_to[rs->nn] = 0;	/* alpha**-inf = 0 */
	sr = 1;
	for (i = 0; i < rs->nn; i++) {
		rs->index_of[sr] = i;
		rs->alpha_to[i] = sr;
		sr <<= 1;
		if (sr & (1 << symsize))
			sr ^= gfpoly;
		sr &= rs->nn;
	}
	/* If it's not primitive, exit */
	if(sr != 1)
		goto errpol;

	/* Find prim-th root of 1, used in decoding */
	for(iprim = 1; (iprim % prim) != 0; iprim += rs->nn);
	/* prim-th root of 1, index form */
	rs->iprim = iprim / prim;

	/* Form RS code generator polynomial from its roots */
	rs->genpoly[0] = 1;
	for (i = 0, root = fcr * prim; i < nroots; i++, root += prim) {
		rs->genpoly[i + 1] = 1;
		/* 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->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->index_of[rs->genpoly[0]] + root)];
	}
	/* convert rs->genpoly[] to index form for quicker encoding */
	for (i = 0; i <= nroots; i++)
		rs->genpoly[i] = rs->index_of[rs->genpoly[i]];
	return rs;

	/* Error exit */
errpol:
	kfree(rs->genpoly);
erridx:
	kfree(rs->index_of);
erralp:
	kfree(rs->alpha_to);
errrs:
	kfree(rs);
	return NULL;
}


/**
 *  free_rs - Free the rs control structure, if it is no longer used
 *  @rs:	the control structure which is not longer used by the
 *		caller
 */
void free_rs(struct rs_control *rs)
{
	mutex_lock(&rslistlock);
	rs->users--;
	if(!rs->users) {
		list_del(&rs->list);
		kfree(rs->alpha_to);
		kfree(rs->index_of);
		kfree(rs->genpoly);
		kfree(rs);
	}
	mutex_unlock(&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
 *		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,
			   int nroots)
{
	struct list_head	*tmp;
	struct rs_control	*rs;

	/* Sanity checks */
	if (symsize < 1)
		return NULL;
	if (fcr < 0 || fcr >= (1<<symsize))
    		return NULL;
	if (prim <= 0 || prim >= (1<<symsize))
    		return NULL;
	if (nroots < 0 || nroots >= (1<<symsize))
		return NULL;

	mutex_lock(&rslistlock);

	/* Walk through the list and look for a matching entry */
	list_for_each(tmp, &rslist) {
		rs = list_entry(tmp, struct rs_control, list);
		if (symsize != rs->mm)
			continue;
		if (gfpoly != rs->gfpoly)
			continue;
		if (fcr != rs->fcr)
			continue;
		if (prim != rs->prim)
			continue;
		if (nroots != rs->nroots)
			continue;
		/* We have a matching one already */
		rs->users++;
		goto out;
	}

	/* Create a new one */
	rs = rs_init(symsize, gfpoly, fcr, prim, nroots);
	if (rs) {
		rs->users = 1;
		list_add(&rs->list, &rslist);
	}
out:
	mutex_unlock(&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
 *  @par:	parity data, must be initialized by caller (usually all 0)
 *  @invmsk:	invert data mask (will be xored on data)
 *
 *  The parity uses a uint16_t data type to enable
 *  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,
	       uint16_t invmsk)
{
#include "encode_rs.c"
}
EXPORT_SYMBOL_GPL(encode_rs8);
#endif

#ifdef CONFIG_REED_SOLOMON_DEC8
/**
 *  decode_rs8 - Decode codeword (8bit data width)
 *  @rs:	the rs control structure
 *  @data:	data field of a given type
 *  @par:	received parity data field
 *  @len:	data length
 *  @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!)
 *  @corr:	buffer to store correction bitmask on eras_pos
 *
 *  The syndrome and parity uses a uint16_t data type to enable
 *  symbol size > 8. The calling code must take care of decoding of the
 *  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 *corr)
{
#include "decode_rs.c"
}
EXPORT_SYMBOL_GPL(decode_rs8);
#endif

#ifdef CONFIG_REED_SOLOMON_ENC16
/**
 *  encode_rs16 - Calculate the parity for data values (16bit data width)
 *  @rs:	the rs control structure
 *  @data:	data field of a given type
 *  @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,
	uint16_t invmsk)
{
#include "encode_rs.c"
}
EXPORT_SYMBOL_GPL(encode_rs16);
#endif

#ifdef CONFIG_REED_SOLOMON_DEC16
/**
 *  decode_rs16 - Decode codeword (16bit data width)
 *  @rs:	the rs control structure
 *  @data:	data field of a given type
 *  @par:	received parity data field
 *  @len:	data length
 *  @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!)
 *  @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 *corr)
{
#include "decode_rs.c"
}
EXPORT_SYMBOL_GPL(decode_rs16);
#endif

EXPORT_SYMBOL_GPL(init_rs);
EXPORT_SYMBOL_GPL(free_rs);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Reed Solomon encoder/decoder");
MODULE_AUTHOR("Phil Karn, Thomas Gleixner");
Commit	Line	Data
03ead842	1	/*
1da177e4 LT	2	* lib/reed_solomon/rslib.c
	3	*
	4	* Overview:
	5	* Generic Reed Solomon encoder / decoder library
03ead842	6	*
1da177e4 LT	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	*
03ead842	12	* $Id: rslib.c,v 1.7 2005/11/07 11:14:59 gleixner Exp $
1da177e4 LT	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:
03ead842	19	*
1da177e4 LT	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.
03ead842	28	* Usually a module / driver should initialize the necessary
1da177e4 LT	29	* rs_control structure on module / driver init and release it
1da177e4 LT	30	* on exit.
03ead842 TG	31	* The encoding puts the calculated syndrome into a given syndrome
03ead842 TG	32	* buffer.
1da177e4 LT	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>
97d1f15b	47	#include <linux/mutex.h>
1da177e4 LT	48	#include <asm/semaphore.h>
	49
	50	/* This list holds all currently allocated rs control structures */
	51	static LIST_HEAD (rslist);
	52	/* Protection for the list */
97d1f15b	53	static DEFINE_MUTEX(rslistlock);
1da177e4	54
03ead842	55	/**
1da177e4	56	* rs_init - Initialize a Reed-Solomon codec
1da177e4 LT	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
9dc65576	64	* en/decoding. Fill the arrays according to the given parameters.
1da177e4	65	*/
03ead842	66	static struct rs_control *rs_init(int symsize, int gfpoly, int fcr,
1da177e4 LT	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) {
03ead842 TG	127	rs->genpoly[j] = rs->genpoly[j -1] ^
03ead842 TG	128	rs->alpha_to[rs_modnn(rs,
1da177e4 LT	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 */
03ead842 TG	134	rs->genpoly[0] =
03ead842 TG	135	rs->alpha_to[rs_modnn(rs,
1da177e4 LT	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 */
	144	errpol:
	145	kfree(rs->genpoly);
	146	erridx:
	147	kfree(rs->index_of);
	148	erralp:
	149	kfree(rs->alpha_to);
	150	errrs:
	151	kfree(rs);
	152	return NULL;
	153	}
	154
	155
03ead842	156	/**
9dc65576	157	* free_rs - Free the rs control structure, if it is no longer used
1da177e4 LT	158	* @rs: the control structure which is not longer used by the
	159	* caller
	160	*/
	161	void free_rs(struct rs_control *rs)
	162	{
97d1f15b	163	mutex_lock(&rslistlock);
1da177e4 LT	164	rs->users--;
	165	if(!rs->users) {
	166	list_del(&rs->list);
	167	kfree(rs->alpha_to);
	168	kfree(rs->index_of);
	169	kfree(rs->genpoly);
	170	kfree(rs);
	171	}
97d1f15b	172	mutex_unlock(&rslistlock);
1da177e4 LT	173	}
1da177e4 LT	174
03ead842	175	/**
1da177e4	176	* init_rs - Find a matching or allocate a new rs control structure
1da177e4 LT	177	* @symsize: the symbol size (number of bits)
	178	* @gfpoly: the extended Galois field generator polynomial coefficients,
	179	* with the 0th coefficient in the low order bit. The polynomial
	180	* must be primitive;
03ead842	181	* @fcr: the first consecutive root of the rs code generator polynomial
1da177e4 LT	182	* in index form
	183	* @prim: primitive element to generate polynomial roots
	184	* @nroots: RS code generator polynomial degree (number of roots)
	185	*/
03ead842	186	struct rs_control *init_rs(int symsize, int gfpoly, int fcr, int prim,
1da177e4 LT	187	int nroots)
	188	{
	189	struct list_head *tmp;
	190	struct rs_control *rs;
	191
	192	/* Sanity checks */
	193	if (symsize < 1)
	194	return NULL;
	195	if (fcr < 0 \|\| fcr >= (1<<symsize))
	196	return NULL;
	197	if (prim <= 0 \|\| prim >= (1<<symsize))
	198	return NULL;
03ead842	199	if (nroots < 0 \|\| nroots >= (1<<symsize))
1da177e4	200	return NULL;
03ead842	201
97d1f15b	202	mutex_lock(&rslistlock);
1da177e4 LT	203
	204	/* Walk through the list and look for a matching entry */
	205	list_for_each(tmp, &rslist) {
	206	rs = list_entry(tmp, struct rs_control, list);
	207	if (symsize != rs->mm)
	208	continue;
	209	if (gfpoly != rs->gfpoly)
	210	continue;
	211	if (fcr != rs->fcr)
03ead842	212	continue;
1da177e4	213	if (prim != rs->prim)
03ead842	214	continue;
1da177e4 LT	215	if (nroots != rs->nroots)
	216	continue;
	217	/* We have a matching one already */
	218	rs->users++;
	219	goto out;
	220	}
	221
	222	/* Create a new one */
	223	rs = rs_init(symsize, gfpoly, fcr, prim, nroots);
	224	if (rs) {
	225	rs->users = 1;
	226	list_add(&rs->list, &rslist);
	227	}
03ead842	228	out:
97d1f15b	229	mutex_unlock(&rslistlock);
1da177e4 LT	230	return rs;
	231	}
	232
	233	#ifdef CONFIG_REED_SOLOMON_ENC8
03ead842	234	/**
1da177e4	235	* encode_rs8 - Calculate the parity for data values (8bit data width)
1da177e4 LT	236	* @rs: the rs control structure
1da177e4 LT	237	* @data: data field of a given type
03ead842	238	* @len: data length
1da177e4 LT	239	* @par: parity data, must be initialized by caller (usually all 0)
	240	* @invmsk: invert data mask (will be xored on data)
	241	*
	242	* The parity uses a uint16_t data type to enable
	243	* symbol size > 8. The calling code must take care of encoding of the
	244	* syndrome result for storage itself.
	245	*/
03ead842	246	int encode_rs8(struct rs_control rs, uint8_t data, int len, uint16_t *par,
1da177e4 LT	247	uint16_t invmsk)
	248	{
	249	#include "encode_rs.c"
	250	}
	251	EXPORT_SYMBOL_GPL(encode_rs8);
	252	#endif
	253
	254	#ifdef CONFIG_REED_SOLOMON_DEC8
03ead842	255	/**
1da177e4	256	* decode_rs8 - Decode codeword (8bit data width)
1da177e4 LT	257	* @rs: the rs control structure
	258	* @data: data field of a given type
	259	* @par: received parity data field
	260	* @len: data length
	261	* @s: syndrome data field (if NULL, syndrome is calculated)
	262	* @no_eras: number of erasures
	263	* @eras_pos: position of erasures, can be NULL
	264	* @invmsk: invert data mask (will be xored on data, not on parity!)
	265	* @corr: buffer to store correction bitmask on eras_pos
	266	*
	267	* The syndrome and parity uses a uint16_t data type to enable
	268	* symbol size > 8. The calling code must take care of decoding of the
	269	* syndrome result and the received parity before calling this code.
	270	*/
	271	int decode_rs8(struct rs_control rs, uint8_t data, uint16_t *par, int len,
03ead842	272	uint16_t s, int no_eras, int eras_pos, uint16_t invmsk,
1da177e4 LT	273	uint16_t *corr)
	274	{
	275	#include "decode_rs.c"
	276	}
	277	EXPORT_SYMBOL_GPL(decode_rs8);
	278	#endif
	279
	280	#ifdef CONFIG_REED_SOLOMON_ENC16
	281	/**
	282	* encode_rs16 - Calculate the parity for data values (16bit data width)
1da177e4 LT	283	* @rs: the rs control structure
1da177e4 LT	284	* @data: data field of a given type
03ead842	285	* @len: data length
1da177e4 LT	286	* @par: parity data, must be initialized by caller (usually all 0)
	287	* @invmsk: invert data mask (will be xored on data, not on parity!)
	288	*
	289	* Each field in the data array contains up to symbol size bits of valid data.
	290	*/
03ead842	291	int encode_rs16(struct rs_control rs, uint16_t data, int len, uint16_t *par,
1da177e4 LT	292	uint16_t invmsk)
	293	{
	294	#include "encode_rs.c"
	295	}
	296	EXPORT_SYMBOL_GPL(encode_rs16);
	297	#endif
	298
	299	#ifdef CONFIG_REED_SOLOMON_DEC16
03ead842	300	/**
1da177e4	301	* decode_rs16 - Decode codeword (16bit data width)
1da177e4 LT	302	* @rs: the rs control structure
	303	* @data: data field of a given type
	304	* @par: received parity data field
	305	* @len: data length
	306	* @s: syndrome data field (if NULL, syndrome is calculated)
	307	* @no_eras: number of erasures
	308	* @eras_pos: position of erasures, can be NULL
03ead842	309	* @invmsk: invert data mask (will be xored on data, not on parity!)
1da177e4 LT	310	* @corr: buffer to store correction bitmask on eras_pos
	311	*
	312	* Each field in the data array contains up to symbol size bits of valid data.
	313	*/
	314	int decode_rs16(struct rs_control rs, uint16_t data, uint16_t *par, int len,
03ead842	315	uint16_t s, int no_eras, int eras_pos, uint16_t invmsk,
1da177e4 LT	316	uint16_t *corr)
	317	{
	318	#include "decode_rs.c"
	319	}
	320	EXPORT_SYMBOL_GPL(decode_rs16);
	321	#endif
	322
	323	EXPORT_SYMBOL_GPL(init_rs);
	324	EXPORT_SYMBOL_GPL(free_rs);
	325
	326	MODULE_LICENSE("GPL");
	327	MODULE_DESCRIPTION("Reed Solomon encoder/decoder");
	328	MODULE_AUTHOR("Phil Karn, Thomas Gleixner");
	329