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