/*
* Copyright (C) 1994-1995 Bas Laarhoven.
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: /home/bas/distr/ftape-2.03b/RCS/ftape-bsm.c,v $
$Author: bas $
*
$Revision: 1.7 $
$Date: 1995/04/30 13:15:14 $
$State: Beta $
*
* 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/ftape.h>
#include <linux/string.h>
#include "tracing.h"
#include "ftape-bsm.h"
#include "ftape-ctl.h"
#include "ftape-rw.h"
/* Global vars.
*/
int bad_sector_map_changed = 0;
/* Local vars.
*/
static byte bad_sector_map[BAD_SECTOR_MAP_SIZE];
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(byte * buffer)
{
static byte list[BAD_SECTOR_MAP_SIZE];
unsigned long *src_ptr = (unsigned long *) list;
byte *dst_ptr = bad_sector_map;
unsigned long map;
unsigned sector = 1;
int i;
memcpy(list, bad_sector_map, sizeof(list));
memset(bad_sector_map, 0, sizeof(bad_sector_map));
while ((byte *) src_ptr - list < sizeof(list)) {
map = *src_ptr++;
if (map == EMPTY_SEGMENT) {
*(unsigned long *) dst_ptr = 0x800000 + sector;
dst_ptr += 3;
sector += SECTORS_PER_SEGMENT;
} else {
for (i = 0; i < SECTORS_PER_SEGMENT; ++i) {
if (map & 1) {
*(unsigned long *) dst_ptr = sector;
dst_ptr += 3;
}
map >>= 1;
++sector;
}
}
}
bad_sector_map_changed = 1;
*(buffer + 4) = 4; /* put new format code */
format_code = 4;
}
#endif
byte *
find_end_of_bsm_list(byte * ptr, byte * limit)
{
while (ptr + 2 < limit) {
if (ptr[0] || ptr[1] || ptr[2]) {
ptr += 3;
} else {
return ptr;
}
}
return NULL;
}
void store_bad_sector_map(byte * buffer)
{
TRACE_FUN(8, "store_bad_sector_map");
size_t count;
size_t offset;
/* Store the bad sector map in buffer.
*/
if (format_code == 4) {
offset = 256;
count = sizeof(bad_sector_map);
} else {
offset = 2 * SECTOR_SIZE; /* skip failed sector log */
count = sizeof(bad_sector_map) - (offset - 256);
}
memcpy(buffer + offset, bad_sector_map, count);
TRACE_EXIT;
}
void put_sector(byte ** ptr, unsigned long sector)
{
*(*ptr)++ = sector & 0xff;
sector >>= 8;
*(*ptr)++ = sector & 0xff;
sector >>= 8;
*(*ptr)++ = sector & 0xff;
}
unsigned long get_sector(byte ** ptr, mode_type mode)
{
unsigned long sector;
if (mode == forward) {
sector = *(*ptr)++;
sector += *(*ptr)++ << 8;
sector += *(*ptr)++ << 16;
} else {
sector = *--(*ptr) << 16;
sector += *--(*ptr) << 8;
sector += *--(*ptr);
}
return sector;
}
void extract_bad_sector_map(byte * buffer)
{
TRACE_FUN(8, "extract_bad_sector_map");
/* Fill the bad sector map with the contents of buffer.
*/
if (format_code == 4) {
/* 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.
*/
memcpy(bad_sector_map, buffer + 256, sizeof(bad_sector_map));
} else {
/* non-wide QIC-80 tapes have a failed sector log area that
* mustn't be included in the bad sector map.
*/
memcpy(bad_sector_map, buffer + 256 + FAILED_SECTOR_LOG_SIZE,
sizeof(bad_sector_map) - FAILED_SECTOR_LOG_SIZE);
}
#if 0
/* for testing of bad sector handling at end of tape
*/
((unsigned long *) bad_sector_map)[segments_per_track * tracks_per_tape - 3] = 0x000003e0;
((unsigned long *) bad_sector_map)[segments_per_track * tracks_per_tape - 2] = 0xff3fffff;
((unsigned long *) bad_sector_map)[segments_per_track * tracks_per_tape - 1] = 0xffffe000;
#endif
#if 0
/* Enable to test bad sector handling
*/
((unsigned long *) bad_sector_map)[30] = 0xfffffffe;
((unsigned long *) bad_sector_map)[32] = 0x7fffffff;
((unsigned long *) bad_sector_map)[34] = 0xfffeffff;
((unsigned long *) bad_sector_map)[36] = 0x55555555;
((unsigned long *) bad_sector_map)[38] = 0xffffffff;
((unsigned long *) bad_sector_map)[50] = 0xffff0000;
((unsigned long *) bad_sector_map)[51] = 0xffffffff;
((unsigned long *) bad_sector_map)[52] = 0xffffffff;
((unsigned long *) bad_sector_map)[53] = 0x0000ffff;
#endif
#if 0
/* Enable when testing multiple volume tar dumps.
*/
for (i = first_data_segment; i <= ftape_last_segment.id - 7; ++i) {
((unsigned long *) bad_sector_map)[i] = EMPTY_SEGMENT;
}
#endif
#if 0
/* Enable when testing bit positions in *_error_map
*/
for (i = first_data_segment; i <= ftape_last_segment.id; ++i) {
((unsigned long *) bad_sector_map)[i] |= 0x00ff00ff;
}
#endif
if (tracing > 2) {
unsigned int map;
int good_sectors = 0;
int bad_sectors;
unsigned int total_bad = 0;
int i;
if (format_code == 4 || format_code == 3) {
byte *ptr = bad_sector_map;
unsigned sector;
do {
sector = get_sector(&ptr, forward);
if (sector != 0) {
if (format_code == 4 && sector & 0x800000) {
total_bad += SECTORS_PER_SEGMENT - 3;
TRACEx1(6, "bad segment at sector: %6d", sector & 0x7fffff);
} else {
++total_bad;
TRACEx1(6, "bad sector: %6d", sector);
}
}
} while (sector != 0);
/* Display end-of-file marks
*/
do {
sector = *((unsigned short *) ptr)++;
if (sector) {
TRACEx2(4, "eof mark: %4d/%2d", sector,
*((unsigned short *) ptr)++);
}
} while (sector);
} else {
for (i = first_data_segment;
i < segments_per_track * tracks_per_tape; ++i) {
map = ((unsigned long *) bad_sector_map)[i];
bad_sectors = count_ones(map);
if (bad_sectors > 0) {
TRACEx2(6, "bsm for segment %4d: 0x%08x", i, map);
if (bad_sectors > SECTORS_PER_SEGMENT - 3) {
bad_sectors = SECTORS_PER_SEGMENT - 3;
}
total_bad += bad_sectors;
}
}
}
good_sectors = ((segments_per_track * tracks_per_tape - first_data_segment)
* (SECTORS_PER_SEGMENT - 3)) - total_bad;
TRACEx1(3, "%d Kb usable on this tape",
good_sectors - ftape_last_segment.free);
if (total_bad == 0) {
TRACE(1, "WARNING: this tape has no bad blocks registered !");
} else {
TRACEx1(2, "%d bad sectors", total_bad);
}
}
TRACE_EXIT;
}
unsigned long cvt2map(int sector)
{
return 1 << (((sector & 0x7fffff) - 1) % SECTORS_PER_SEGMENT);
}
int cvt2segment(int sector)
{
return ((sector & 0x7fffff) - 1) / SECTORS_PER_SEGMENT;
}
int forward_seek_entry(int segment_id, byte ** ptr, unsigned long *map)
{
byte *tmp_ptr;
unsigned long sector;
int segment;
int count;
do {
sector = get_sector(ptr, forward);
segment = cvt2segment(sector);
} while (sector != 0 && segment < segment_id);
tmp_ptr = *ptr - 3; /* point to first sector >= segment_id */
/* Get all sectors in segment_id
*/
if (format_code == 4 && (sector & 0x800000) && segment == segment_id) {
*map = EMPTY_SEGMENT;
count = 32;
} else {
*map = 0;
count = 0;
while (sector != 0 && segment == segment_id) {
*map |= cvt2map(sector);
sector = get_sector(ptr, forward);
segment = cvt2segment(sector);
++count;
}
}
*ptr = tmp_ptr;
return count;
}
int backwards_seek_entry(int segment_id, byte ** ptr, unsigned long *map)
{
unsigned long sector;
int segment;
int count;
*map = 0;
if (*ptr > bad_sector_map) {
do {
sector = get_sector(ptr, backward);
segment = cvt2segment(sector);
} while (*ptr > bad_sector_map && segment > segment_id);
count = 0;
if (segment > segment_id) {
/* at start of list, no entry found */
} else if (segment < segment_id) {
/* before smaller entry, adjust for overshoot */
*ptr += 3;
} else {
/* get all sectors in segment_id */
if (format_code == 4 && (sector & 0x800000)) {
*map = EMPTY_SEGMENT;
count = 32;
} else {
do {
*map |= cvt2map(sector);
++count;
if (*ptr <= bad_sector_map) {
break;
}
sector = get_sector(ptr, backward);
segment = cvt2segment(sector);
} while (segment == segment_id);
if (segment < segment_id) {
*ptr += 3;
}
}
}
} else {
count = 0;
}
return count;
}
void put_bad_sector_entry(int segment_id, unsigned long new_map)
{
byte *ptr = bad_sector_map;
int count;
int new_count;
unsigned long map;
if (format_code == 3 || format_code == 4) {
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 (new_count == 32 && format_code == 4) {
new_count = 1;
}
if (count != new_count) {
/* insert (or delete if < 0) new_count - count entries.
* Move trailing part of list including terminating 0.
*/
byte *hi_ptr = ptr;
do {
} while (get_sector(&hi_ptr, forward) != 0);
memmove(ptr + new_count, ptr + count, hi_ptr - (ptr + count));
}
if (new_count == 1 && new_map == EMPTY_SEGMENT) {
put_sector(&ptr, 0x800001 + segment_id * SECTORS_PER_SEGMENT);
} else {
int i = 0;
while (new_map) {
if (new_map & 1) {
put_sector(&ptr, 1 + segment_id * SECTORS_PER_SEGMENT + i);
}
++i;
new_map >>= 1;
}
}
} else {
((unsigned long *) bad_sector_map)[segment_id] = new_map;
}
bad_sector_map_changed = 1;
}
unsigned long get_bad_sector_entry(int segment_id)
{
TRACE_FUN(8, "get_bad_sector_entry");
static unsigned long map = 0;
if (used_header_segment == -1) {
/* When reading header segment we'll need a blank map.
*/
map = 0;
} else if (format_code == 3 || format_code == 4) {
/* Invariants:
* map - mask value returned on last call.
* 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 byte *ptr = bad_sector_map;
if (segment_id > last_reference) {
/* Skip all sectors before segment_id
*/
forward_seek_entry(segment_id, &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, &ptr, &map);
} /* segment_id == last_reference : keep map */
last_reference = segment_id;
} else {
map = ((unsigned long *) bad_sector_map)[segment_id];
}
TRACE_EXIT;
return map;
}
void ftape_init_bsm(void)
{
memset(bad_sector_map, 0, sizeof(bad_sector_map));
}
