patch-1.3.72 linux/drivers/char/ftape/ftape-bsm.c

• Lines: 430
• Date: Wed Mar 6 15:07:19 1996
• Orig file: v1.3.71/linux/drivers/char/ftape/ftape-bsm.c
• Orig date: Thu Jan 1 02:00:00 1970

diff -u --recursive --new-file v1.3.71/linux/drivers/char/ftape/ftape-bsm.c linux/drivers/char/ftape/ftape-bsm.c
@@ -0,0 +1,429 @@
+/*
+ *      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/module.h>
+#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));
+}