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/*
* Copyright (C) 1994-1996 Bas Laarhoven,
* (C) 1996-1997 Claus Heine.
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-bsm.c,v $
* $Revision: 1.3 $
* $Date: 1997/10/05 19:15:15 $
*
* This file contains the bad-sector map handling code for
* the QIC-117 floppy tape driver for Linux.
* QIC-40, QIC-80, QIC-3010 and QIC-3020 maps are implemented.
*/
#include <linux/string.h>
#include <linux/ftape.h>
#include "../lowlevel/ftape-tracing.h"
#include "../lowlevel/ftape-bsm.h"
#include "../lowlevel/ftape-ctl.h"
#include "../lowlevel/ftape-rw.h"
/* Global vars.
*/
/* Local vars.
*/
static __u8 *bad_sector_map;
static SectorCount *bsm_hash_ptr;
typedef enum {
forward, backward
} mode_type;
#if 0
/* fix_tape converts a normal QIC-80 tape into a 'wide' tape.
* For testing purposes only !
*/
void fix_tape(__u8 * buffer, ft_format_type new_code)
{
static __u8 list[BAD_SECTOR_MAP_SIZE];
SectorMap *src_ptr = (SectorMap *) list;
__u8 *dst_ptr = bad_sector_map;
SectorMap map;
unsigned int sector = 1;
int i;
if (format_code != fmt_var && format_code != fmt_big) {
memcpy(list, bad_sector_map, sizeof(list));
memset(bad_sector_map, 0, sizeof(bad_sector_map));
while ((__u8 *) src_ptr - list < sizeof(list)) {
map = *src_ptr++;
if (map == EMPTY_SEGMENT) {
*(SectorMap *) dst_ptr = 0x800000 + sector;
dst_ptr += 3;
sector += SECTORS_PER_SEGMENT;
} else {
for (i = 0; i < SECTORS_PER_SEGMENT; ++i) {
if (map & 1) {
*(SewctorMap *) dst_ptr = sector;
dst_ptr += 3;
}
map >>= 1;
++sector;
}
}
}
}
bad_sector_map_changed = 1;
*(buffer + 4) = new_code; /* put new format code */
if (format_code != fmt_var && new_code == fmt_big) {
PUT4(buffer, FT_6_HSEG_1, (__u32)GET2(buffer, 6));
PUT4(buffer, FT_6_HSEG_2, (__u32)GET2(buffer, 8));
PUT4(buffer, FT_6_FRST_SEG, (__u32)GET2(buffer, 10));
PUT4(buffer, FT_6_LAST_SEG, (__u32)GET2(buffer, 12));
memset(buffer+6, '\0', 8);
}
format_code = new_code;
}
#endif
/* given buffer that contains a header segment, find the end of
* of the bsm list
*/
__u8 * ftape_find_end_of_bsm_list(__u8 * address)
{
__u8 *ptr = address + FT_HEADER_END; /* start of bsm list */
__u8 *limit = address + FT_SEGMENT_SIZE;
while (ptr + 2 < limit) {
if (ptr[0] || ptr[1] || ptr[2]) {
ptr += 3;
} else {
return ptr;
}
}
return NULL;
}
static inline void put_sector(SectorCount *ptr, unsigned int sector)
{
ptr->bytes[0] = sector & 0xff;
sector >>= 8;
ptr->bytes[1] = sector & 0xff;
sector >>= 8;
ptr->bytes[2] = sector & 0xff;
}
static inline unsigned int get_sector(SectorCount *ptr)
{
#if 1
unsigned int sector;
sector = ptr->bytes[0];
sector += ptr->bytes[1] << 8;
sector += ptr->bytes[2] << 16;
return sector;
#else
/* GET4 gets the next four bytes in Intel little endian order
* and converts them to host byte order and handles unaligned
* access.
*/
return (GET4(ptr, 0) & 0x00ffffff); /* back to host byte order */
#endif
}
static void bsm_debug_fake(void)
{
/* for testing of bad sector handling at end of tape
*/
#if 0
ftape_put_bad_sector_entry(segments_per_track * tracks_per_tape - 3,
0x000003e0;
ftape_put_bad_sector_entry(segments_per_track * tracks_per_tape - 2,
0xff3fffff;
ftape_put_bad_sector_entry(segments_per_track * tracks_per_tape - 1,
0xffffe000;
#endif
/* Enable to test bad sector handling
*/
#if 0
ftape_put_bad_sector_entry(30, 0xfffffffe)
ftape_put_bad_sector_entry(32, 0x7fffffff);
ftape_put_bad_sector_entry(34, 0xfffeffff);
ftape_put_bad_sector_entry(36, 0x55555555);
ftape_put_bad_sector_entry(38, 0xffffffff);
ftape_put_bad_sector_entry(50, 0xffff0000);
ftape_put_bad_sector_entry(51, 0xffffffff);
ftape_put_bad_sector_entry(52, 0xffffffff);
ftape_put_bad_sector_entry(53, 0x0000ffff);
#endif
/* Enable when testing multiple volume tar dumps.
*/
#if 0
{
int i;
for (i = ft_first_data_segment;
i <= ft_last_data_segment - 7; ++i) {
ftape_put_bad_sector_entry(i, EMPTY_SEGMENT);
}
}
#endif
/* Enable when testing bit positions in *_error_map
*/
#if 0
{
int i;
for (i = first_data_segment; i <= last_data_segment; ++i) {
ftape_put_bad_sector_entry(i,
ftape_get_bad_sector_entry(i)
| 0x00ff00ff);
}
}
#endif
}
static void print_bad_sector_map(void)
{
unsigned int good_sectors;
unsigned int total_bad = 0;
int i;
TRACE_FUN(ft_t_flow);
if (ft_format_code == fmt_big ||
ft_format_code == fmt_var ||
ft_format_code == fmt_1100ft) {
SectorCount *ptr = (SectorCount *)bad_sector_map;
unsigned int sector;
while((sector = get_sector(ptr++)) != 0) {
if ((ft_format_code == fmt_big ||
ft_format_code == fmt_var) &&
sector & 0x800000) {
total_bad += FT_SECTORS_PER_SEGMENT - 3;
TRACE(ft_t_noise, "bad segment at sector: %6d",
sector & 0x7fffff);
} else {
++total_bad;
TRACE(ft_t_noise, "bad sector: %6d", sector);
}
}
/* Display old ftape's end-of-file marks
*/
while ((sector = get_unaligned(((__u16*)ptr)++)) != 0) {
TRACE(ft_t_noise, "Old ftape eof mark: %4d/%2d",
sector, get_unaligned(((__u16*)ptr)++));
}
} else { /* fixed size format */
for (i = ft_first_data_segment;
i < (int)(ft_segments_per_track * ft_tracks_per_tape); ++i) {
SectorMap map = ((SectorMap *) bad_sector_map)[i];
if (map) {
TRACE(ft_t_noise,
"bsm for segment %4d: 0x%08x", i, (unsigned int)map);
total_bad += ((map == EMPTY_SEGMENT)
? FT_SECTORS_PER_SEGMENT - 3
: count_ones(map));
}
}
}
good_sectors =
((ft_segments_per_track * ft_tracks_per_tape - ft_first_data_segment)
* (FT_SECTORS_PER_SEGMENT - 3)) - total_bad;
TRACE(ft_t_info, "%d Kb usable on this tape", good_sectors);
if (total_bad == 0) {
TRACE(ft_t_info,
"WARNING: this tape has no bad blocks registered !");
} else {
TRACE(ft_t_info, "%d bad sectors", total_bad);
}
TRACE_EXIT;
}
void ftape_extract_bad_sector_map(__u8 * buffer)
{
TRACE_FUN(ft_t_any);
/* Fill the bad sector map with the contents of buffer.
*/
if (ft_format_code == fmt_var || ft_format_code == fmt_big) {
/* QIC-3010/3020 and wide QIC-80 tapes no longer have a failed
* sector log but use this area to extend the bad sector map.
*/
bad_sector_map = &buffer[FT_HEADER_END];
} else {
/* non-wide QIC-80 tapes have a failed sector log area that
* mustn't be included in the bad sector map.
*/
bad_sector_map = &buffer[FT_FSL + FT_FSL_SIZE];
}
if (ft_format_code == fmt_1100ft ||
ft_format_code == fmt_var ||
ft_format_code == fmt_big) {
bsm_hash_ptr = (SectorCount *)bad_sector_map;
} else {
bsm_hash_ptr = NULL;
}
bsm_debug_fake();
if (TRACE_LEVEL >= ft_t_info) {
print_bad_sector_map();
}
TRACE_EXIT;
}
static inline SectorMap cvt2map(unsigned int sector)
{
return 1 << (((sector & 0x7fffff) - 1) % FT_SECTORS_PER_SEGMENT);
}
static inline int cvt2segment(unsigned int sector)
{
return ((sector & 0x7fffff) - 1) / FT_SECTORS_PER_SEGMENT;
}
static int forward_seek_entry(int segment_id,
SectorCount **ptr,
SectorMap *map)
{
unsigned int sector;
int segment;
do {
sector = get_sector((*ptr)++);
segment = cvt2segment(sector);
} while (sector != 0 && segment < segment_id);
(*ptr) --; /* point to first sector >= segment_id */
/* Get all sectors in segment_id
*/
if (sector == 0 || segment != segment_id) {
*map = 0;
return 0;
} else if ((sector & 0x800000) &&
(ft_format_code == fmt_var || ft_format_code == fmt_big)) {
*map = EMPTY_SEGMENT;
return FT_SECTORS_PER_SEGMENT;
} else {
int count = 1;
SectorCount *tmp_ptr = (*ptr) + 1;
*map = cvt2map(sector);
while ((sector = get_sector(tmp_ptr++)) != 0 &&
(segment = cvt2segment(sector)) == segment_id) {
*map |= cvt2map(sector);
++count;
}
return count;
}
}
static int backwards_seek_entry(int segment_id,
SectorCount **ptr,
SectorMap *map)
{
unsigned int sector;
int segment; /* max unsigned int */
if (*ptr <= (SectorCount *)bad_sector_map) {
*map = 0;
return 0;
}
do {
sector = get_sector(--(*ptr));
segment = cvt2segment(sector);
} while (*ptr > (SectorCount *)bad_sector_map && segment > segment_id);
if (segment > segment_id) { /* at start of list, no entry found */
*map = 0;
return 0;
} else if (segment < segment_id) {
/* before smaller entry, adjust for overshoot */
(*ptr) ++;
*map = 0;
return 0;
} else if ((sector & 0x800000) &&
(ft_format_code == fmt_big || ft_format_code == fmt_var)) {
*map = EMPTY_SEGMENT;
return FT_SECTORS_PER_SEGMENT;
} else { /* get all sectors in segment_id */
int count = 1;
*map = cvt2map(sector);
while(*ptr > (SectorCount *)bad_sector_map) {
sector = get_sector(--(*ptr));
segment = cvt2segment(sector);
if (segment != segment_id) {
break;
}
*map |= cvt2map(sector);
++count;
}
if (segment < segment_id) {
(*ptr) ++;
}
return count;
}
}
void ftape_put_bad_sector_entry(int segment_id, SectorMap new_map)
{
SectorCount *ptr = (SectorCount *)bad_sector_map;
int count;
int new_count;
SectorMap map;
TRACE_FUN(ft_t_any);
if (ft_format_code == fmt_1100ft ||
ft_format_code == fmt_var ||
ft_format_code == fmt_big) {
count = forward_seek_entry(segment_id, &ptr, &map);
new_count = count_ones(new_map);
/* If format code == 4 put empty segment instead of 32
* bad sectors.
*/
if (ft_format_code == fmt_var || ft_format_code == fmt_big) {
if (new_count == FT_SECTORS_PER_SEGMENT) {
new_count = 1;
}
if (count == FT_SECTORS_PER_SEGMENT) {
count = 1;
}
}
if (count != new_count) {
/* insert (or delete if < 0) new_count - count
* entries. Move trailing part of list
* including terminating 0.
*/
SectorCount *hi_ptr = ptr;
do {
} while (get_sector(hi_ptr++) != 0);
/* Note: ptr is of type byte *, and each bad sector
* consumes 3 bytes.
*/
memmove(ptr + new_count, ptr + count,
(size_t)(hi_ptr - (ptr + count))*sizeof(SectorCount));
}
TRACE(ft_t_noise, "putting map 0x%08x at %p, segment %d",
(unsigned int)new_map, ptr, segment_id);
if (new_count == 1 && new_map == EMPTY_SEGMENT) {
put_sector(ptr++, (0x800001 +
segment_id *
FT_SECTORS_PER_SEGMENT));
} else {
int i = 0;
while (new_map) {
if (new_map & 1) {
put_sector(ptr++,
1 + segment_id *
FT_SECTORS_PER_SEGMENT + i);
}
++i;
new_map >>= 1;
}
}
} else {
((SectorMap *) bad_sector_map)[segment_id] = new_map;
}
TRACE_EXIT;
}
SectorMap ftape_get_bad_sector_entry(int segment_id)
{
if (ft_used_header_segment == -1) {
/* When reading header segment we'll need a blank map.
*/
return 0;
} else if (bsm_hash_ptr != NULL) {
/* Invariants:
* map - mask value returned on last call.
* bsm_hash_ptr - points to first sector greater or equal to
* first sector in last_referenced segment.
* last_referenced - segment id used in the last call,
* sector and map belong to this id.
* This code is designed for sequential access and retries.
* For true random access it may have to be redesigned.
*/
static int last_reference = -1;
static SectorMap map;
if (segment_id > last_reference) {
/* Skip all sectors before segment_id
*/
forward_seek_entry(segment_id, &bsm_hash_ptr, &map);
} else if (segment_id < last_reference) {
/* Skip backwards until begin of buffer or
* first sector in segment_id
*/
backwards_seek_entry(segment_id, &bsm_hash_ptr, &map);
} /* segment_id == last_reference : keep map */
last_reference = segment_id;
return map;
} else {
return ((SectorMap *) bad_sector_map)[segment_id];
}
}
/* This is simply here to prevent us from overwriting other kernel
* data. Writes will result in NULL Pointer dereference.
*/
void ftape_init_bsm(void)
{
bad_sector_map = NULL;
bsm_hash_ptr = NULL;
}
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