diff options
Diffstat (limited to 'drivers/char/ftape/lowlevel/ftape-ecc.h')
-rw-r--r-- | drivers/char/ftape/lowlevel/ftape-ecc.h | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/drivers/char/ftape/lowlevel/ftape-ecc.h b/drivers/char/ftape/lowlevel/ftape-ecc.h new file mode 100644 index 00000000000..4829146fe9a --- /dev/null +++ b/drivers/char/ftape/lowlevel/ftape-ecc.h @@ -0,0 +1,84 @@ +#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_ */ |