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#ifndef _FTAPE_ECC_H_
#define _FTAPE_ECC_H_
/*
* Copyright (C) 1993 Ning and David Mosberger.
* Original:
* Copyright (C) 1993 Bas Laarhoven.
* Copyright (C) 1992 David L. Brown, Jr.
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2, or (at
your option) any later version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; see the file COPYING. If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
USA.
*
* $Source: /homes/cvs/ftape-stacked/ftape/lowlevel/ftape-ecc.h,v $
* $Revision: 1.2 $
* $Date: 1997/10/05 19:18:11 $
*
* This file contains the definitions for the
* Reed-Solomon error correction code
* for the QIC-40/80 tape streamer device driver.
*/
#include "../lowlevel/ftape-bsm.h"
#define BAD_CLEAR(entry) ((entry)=0)
#define BAD_SET(entry,sector) ((entry)|=(1<<(sector)))
#define BAD_CHECK(entry,sector) ((entry)&(1<<(sector)))
/*
* Return values for ecc_correct_data:
*/
enum {
ECC_OK, /* Data was correct. */
ECC_CORRECTED, /* Correctable error in data. */
ECC_FAILED, /* Could not correct data. */
};
/*
* Representation of an in memory segment. MARKED_BAD lists the
* sectors that were marked bad during formatting. If the N-th sector
* in a segment is marked bad, bit 1<<N will be set in MARKED_BAD.
* The sectors should be read in from the disk and packed, as if the
* bad sectors were not there, and the segment just contained fewer
* sectors. READ_SECTORS is a bitmap of errors encountered while
* reading the data. These offsets are relative to the packed data.
* BLOCKS is a count of the sectors not marked bad. This is just to
* prevent having to count the zero bits in MARKED_BAD each time this
* is needed. DATA is the actual sector packed data from (or to) the
* tape.
*/
struct memory_segment {
SectorMap marked_bad;
SectorMap read_bad;
int blocks;
__u8 *data;
SectorMap corrected;
};
/*
* ecc.c defined global variables:
*/
#ifdef TEST
extern int ftape_ecc_tracing;
#endif
/*
* ecc.c defined global functions:
*/
extern int ftape_ecc_correct_data(struct memory_segment *data);
extern int ftape_ecc_set_segment_parity(struct memory_segment *data);
#endif /* _FTAPE_ECC_H_ */
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