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path: root/drivers/char/ftape/lowlevel/ftape-read.c
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-rw-r--r--drivers/char/ftape/lowlevel/ftape-read.c621
1 files changed, 621 insertions, 0 deletions
diff --git a/drivers/char/ftape/lowlevel/ftape-read.c b/drivers/char/ftape/lowlevel/ftape-read.c
new file mode 100644
index 000000000000..d967d8cd86dc
--- /dev/null
+++ b/drivers/char/ftape/lowlevel/ftape-read.c
@@ -0,0 +1,621 @@
+/*
+ * Copyright (C) 1993-1996 Bas Laarhoven,
+ * (C) 1996-1997 Claus-Justus 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-read.c,v $
+ * $Revision: 1.6 $
+ * $Date: 1997/10/21 14:39:22 $
+ *
+ * This file contains the reading code
+ * for the QIC-117 floppy-tape driver for Linux.
+ *
+ */
+
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/mm.h>
+
+#include <linux/ftape.h>
+#include <linux/qic117.h>
+#include "../lowlevel/ftape-tracing.h"
+#include "../lowlevel/ftape-read.h"
+#include "../lowlevel/ftape-io.h"
+#include "../lowlevel/ftape-ctl.h"
+#include "../lowlevel/ftape-rw.h"
+#include "../lowlevel/ftape-write.h"
+#include "../lowlevel/ftape-ecc.h"
+#include "../lowlevel/ftape-bsm.h"
+
+/* Global vars.
+ */
+
+/* Local vars.
+ */
+
+void ftape_zap_read_buffers(void)
+{
+ int i;
+
+ for (i = 0; i < ft_nr_buffers; ++i) {
+/* changed to "fit" with dynamic allocation of tape_buffer. --khp */
+ ft_buffer[i]->status = waiting;
+ ft_buffer[i]->bytes = 0;
+ ft_buffer[i]->skip = 0;
+ ft_buffer[i]->retry = 0;
+ }
+/* ftape_reset_buffer(); */
+}
+
+static SectorMap convert_sector_map(buffer_struct * buff)
+{
+ int i = 0;
+ SectorMap bad_map = ftape_get_bad_sector_entry(buff->segment_id);
+ SectorMap src_map = buff->soft_error_map | buff->hard_error_map;
+ SectorMap dst_map = 0;
+ TRACE_FUN(ft_t_any);
+
+ if (bad_map || src_map) {
+ TRACE(ft_t_flow, "bad_map = 0x%08lx", (long) bad_map);
+ TRACE(ft_t_flow, "src_map = 0x%08lx", (long) src_map);
+ }
+ while (bad_map) {
+ while ((bad_map & 1) == 0) {
+ if (src_map & 1) {
+ dst_map |= (1 << i);
+ }
+ src_map >>= 1;
+ bad_map >>= 1;
+ ++i;
+ }
+ /* (bad_map & 1) == 1 */
+ src_map >>= 1;
+ bad_map >>= 1;
+ }
+ if (src_map) {
+ dst_map |= (src_map << i);
+ }
+ if (dst_map) {
+ TRACE(ft_t_flow, "dst_map = 0x%08lx", (long) dst_map);
+ }
+ TRACE_EXIT dst_map;
+}
+
+static int correct_and_copy_fraction(buffer_struct *buff, __u8 * destination,
+ int start, int size)
+{
+ struct memory_segment mseg;
+ int result;
+ SectorMap read_bad;
+ TRACE_FUN(ft_t_any);
+
+ mseg.read_bad = convert_sector_map(buff);
+ mseg.marked_bad = 0; /* not used... */
+ mseg.blocks = buff->bytes / FT_SECTOR_SIZE;
+ mseg.data = buff->address;
+ /* If there are no data sectors we can skip this segment.
+ */
+ if (mseg.blocks <= 3) {
+ TRACE_ABORT(0, ft_t_noise, "empty segment");
+ }
+ read_bad = mseg.read_bad;
+ ft_history.crc_errors += count_ones(read_bad);
+ result = ftape_ecc_correct_data(&mseg);
+ if (read_bad != 0 || mseg.corrected != 0) {
+ TRACE(ft_t_noise, "crc error map: 0x%08lx", (unsigned long)read_bad);
+ TRACE(ft_t_noise, "corrected map: 0x%08lx", (unsigned long)mseg.corrected);
+ ft_history.corrected += count_ones(mseg.corrected);
+ }
+ if (result == ECC_CORRECTED || result == ECC_OK) {
+ if (result == ECC_CORRECTED) {
+ TRACE(ft_t_info, "ecc corrected segment: %d", buff->segment_id);
+ }
+ if(start < 0) {
+ start= 0;
+ }
+ if((start+size) > ((mseg.blocks - 3) * FT_SECTOR_SIZE)) {
+ size = (mseg.blocks - 3) * FT_SECTOR_SIZE - start;
+ }
+ if (size < 0) {
+ size= 0;
+ }
+ if(size > 0) {
+ memcpy(destination + start, mseg.data + start, size);
+ }
+ if ((read_bad ^ mseg.corrected) & mseg.corrected) {
+ /* sectors corrected without crc errors set */
+ ft_history.crc_failures++;
+ }
+ TRACE_EXIT size; /* (mseg.blocks - 3) * FT_SECTOR_SIZE; */
+ } else {
+ ft_history.ecc_failures++;
+ TRACE_ABORT(-EAGAIN,
+ ft_t_err, "ecc failure on segment %d",
+ buff->segment_id);
+ }
+ TRACE_EXIT 0;
+}
+
+/* Read given segment into buffer at address.
+ */
+int ftape_read_segment_fraction(const int segment_id,
+ void *address,
+ const ft_read_mode_t read_mode,
+ const int start,
+ const int size)
+{
+ int result = 0;
+ int retry = 0;
+ int bytes_read = 0;
+ int read_done = 0;
+ TRACE_FUN(ft_t_flow);
+
+ ft_history.used |= 1;
+ TRACE(ft_t_data_flow, "segment_id = %d", segment_id);
+ if (ft_driver_state != reading) {
+ TRACE(ft_t_noise, "calling ftape_abort_operation");
+ TRACE_CATCH(ftape_abort_operation(),);
+ ftape_set_state(reading);
+ }
+ for(;;) {
+ buffer_struct *tail;
+ /* Allow escape from this loop on signal !
+ */
+ FT_SIGNAL_EXIT(_DONT_BLOCK);
+ /* Search all full buffers for the first matching the
+ * wanted segment. Clear other buffers on the fly.
+ */
+ tail = ftape_get_buffer(ft_queue_tail);
+ while (!read_done && tail->status == done) {
+ /* Allow escape from this loop on signal !
+ */
+ FT_SIGNAL_EXIT(_DONT_BLOCK);
+ if (tail->segment_id == segment_id) {
+ /* If out buffer is already full,
+ * return its contents.
+ */
+ TRACE(ft_t_flow, "found segment in cache: %d",
+ segment_id);
+ if (tail->deleted) {
+ /* Return a value that
+ * read_header_segment
+ * understands. As this
+ * should only occur when
+ * searching for the header
+ * segments it shouldn't be
+ * misinterpreted elsewhere.
+ */
+ TRACE_EXIT 0;
+ }
+ result = correct_and_copy_fraction(
+ tail,
+ address,
+ start,
+ size);
+ TRACE(ft_t_flow, "segment contains (bytes): %d",
+ result);
+ if (result < 0) {
+ if (result != -EAGAIN) {
+ TRACE_EXIT result;
+ }
+ /* keep read_done == 0, will
+ * trigger
+ * ftape_abort_operation
+ * because reading wrong
+ * segment.
+ */
+ TRACE(ft_t_err, "ecc failed, retry");
+ ++retry;
+ } else {
+ read_done = 1;
+ bytes_read = result;
+ }
+ } else {
+ TRACE(ft_t_flow,"zapping segment in cache: %d",
+ tail->segment_id);
+ }
+ tail->status = waiting;
+ tail = ftape_next_buffer(ft_queue_tail);
+ }
+ if (!read_done && tail->status == reading) {
+ if (tail->segment_id == segment_id) {
+ switch(ftape_wait_segment(reading)) {
+ case 0:
+ break;
+ case -EINTR:
+ TRACE_ABORT(-EINTR, ft_t_warn,
+ "interrupted by "
+ "non-blockable signal");
+ break;
+ default:
+ TRACE(ft_t_noise,
+ "wait_segment failed");
+ ftape_abort_operation();
+ ftape_set_state(reading);
+ break;
+ }
+ } else {
+ /* We're reading the wrong segment,
+ * stop runner.
+ */
+ TRACE(ft_t_noise, "reading wrong segment");
+ ftape_abort_operation();
+ ftape_set_state(reading);
+ }
+ }
+ /* should runner stop ?
+ */
+ if (ft_runner_status == aborting) {
+ buffer_struct *head = ftape_get_buffer(ft_queue_head);
+ switch(head->status) {
+ case error:
+ ft_history.defects +=
+ count_ones(head->hard_error_map);
+ case reading:
+ head->status = waiting;
+ break;
+ default:
+ break;
+ }
+ TRACE_CATCH(ftape_dumb_stop(),);
+ } else {
+ /* If just passed last segment on tape: wait
+ * for BOT or EOT mark. Sets ft_runner_status to
+ * idle if at lEOT and successful
+ */
+ TRACE_CATCH(ftape_handle_logical_eot(),);
+ }
+ /* If we got a segment: quit, or else retry up to limit.
+ *
+ * If segment to read is empty, do not start runner for it,
+ * but wait for next read call.
+ */
+ if (read_done ||
+ ftape_get_bad_sector_entry(segment_id) == EMPTY_SEGMENT ) {
+ /* bytes_read = 0; should still be zero */
+ TRACE_EXIT bytes_read;
+
+ }
+ if (retry > FT_RETRIES_ON_ECC_ERROR) {
+ ft_history.defects++;
+ TRACE_ABORT(-ENODATA, ft_t_err,
+ "too many retries on ecc failure");
+ }
+ /* Now at least one buffer is empty !
+ * Restart runner & tape if needed.
+ */
+ TRACE(ft_t_any, "head: %d, tail: %d, ft_runner_status: %d",
+ ftape_buffer_id(ft_queue_head),
+ ftape_buffer_id(ft_queue_tail),
+ ft_runner_status);
+ TRACE(ft_t_any, "buffer[].status, [head]: %d, [tail]: %d",
+ ftape_get_buffer(ft_queue_head)->status,
+ ftape_get_buffer(ft_queue_tail)->status);
+ tail = ftape_get_buffer(ft_queue_tail);
+ if (tail->status == waiting) {
+ buffer_struct *head = ftape_get_buffer(ft_queue_head);
+
+ ftape_setup_new_segment(head, segment_id, -1);
+ if (read_mode == FT_RD_SINGLE) {
+ /* disable read-ahead */
+ head->next_segment = 0;
+ }
+ ftape_calc_next_cluster(head);
+ if (ft_runner_status == idle) {
+ result = ftape_start_tape(segment_id,
+ head->sector_offset);
+ if (result < 0) {
+ TRACE_ABORT(result, ft_t_err, "Error: "
+ "segment %d unreachable",
+ segment_id);
+ }
+ }
+ head->status = reading;
+ fdc_setup_read_write(head, FDC_READ);
+ }
+ }
+ /* not reached */
+ TRACE_EXIT -EIO;
+}
+
+int ftape_read_header_segment(__u8 *address)
+{
+ int result;
+ int header_segment;
+ int first_failed = 0;
+ int status;
+ TRACE_FUN(ft_t_flow);
+
+ ft_used_header_segment = -1;
+ TRACE_CATCH(ftape_report_drive_status(&status),);
+ TRACE(ft_t_flow, "reading...");
+ /* We're looking for the first header segment.
+ * A header segment cannot contain bad sectors, therefor at the
+ * tape start, segments with bad sectors are (according to QIC-40/80)
+ * written with deleted data marks and must be skipped.
+ */
+ memset(address, '\0', (FT_SECTORS_PER_SEGMENT - 3) * FT_SECTOR_SIZE);
+ result = 0;
+#define HEADER_SEGMENT_BOUNDARY 68 /* why not 42? */
+ for (header_segment = 0;
+ header_segment < HEADER_SEGMENT_BOUNDARY && result == 0;
+ ++header_segment) {
+ /* Set no read-ahead, the isr will force read-ahead whenever
+ * it encounters deleted data !
+ */
+ result = ftape_read_segment(header_segment,
+ address,
+ FT_RD_SINGLE);
+ if (result < 0 && !first_failed) {
+ TRACE(ft_t_err, "header segment damaged, trying backup");
+ first_failed = 1;
+ result = 0; /* force read of next (backup) segment */
+ }
+ }
+ if (result < 0 || header_segment >= HEADER_SEGMENT_BOUNDARY) {
+ TRACE_ABORT(-EIO, ft_t_err,
+ "no readable header segment found");
+ }
+ TRACE_CATCH(ftape_abort_operation(),);
+ ft_used_header_segment = header_segment;
+ result = ftape_decode_header_segment(address);
+ TRACE_EXIT result;
+}
+
+int ftape_decode_header_segment(__u8 *address)
+{
+ unsigned int max_floppy_side;
+ unsigned int max_floppy_track;
+ unsigned int max_floppy_sector;
+ unsigned int new_tape_len;
+ TRACE_FUN(ft_t_flow);
+
+ if (GET4(address, FT_SIGNATURE) == FT_D2G_MAGIC) {
+ /* Ditto 2GB header segment. They encrypt the bad sector map.
+ * We decrypt it and store them in normal format.
+ * I hope this is correct.
+ */
+ int i;
+ TRACE(ft_t_warn,
+ "Found Ditto 2GB tape, "
+ "trying to decrypt bad sector map");
+ for (i=256; i < 29 * FT_SECTOR_SIZE; i++) {
+ address[i] = ~(address[i] - (i&0xff));
+ }
+ PUT4(address, 0,FT_HSEG_MAGIC);
+ } else if (GET4(address, FT_SIGNATURE) != FT_HSEG_MAGIC) {
+ TRACE_ABORT(-EIO, ft_t_err,
+ "wrong signature in header segment");
+ }
+ ft_format_code = (ft_format_type) address[FT_FMT_CODE];
+ if (ft_format_code != fmt_big) {
+ ft_header_segment_1 = GET2(address, FT_HSEG_1);
+ ft_header_segment_2 = GET2(address, FT_HSEG_2);
+ ft_first_data_segment = GET2(address, FT_FRST_SEG);
+ ft_last_data_segment = GET2(address, FT_LAST_SEG);
+ } else {
+ ft_header_segment_1 = GET4(address, FT_6_HSEG_1);
+ ft_header_segment_2 = GET4(address, FT_6_HSEG_2);
+ ft_first_data_segment = GET4(address, FT_6_FRST_SEG);
+ ft_last_data_segment = GET4(address, FT_6_LAST_SEG);
+ }
+ TRACE(ft_t_noise, "first data segment: %d", ft_first_data_segment);
+ TRACE(ft_t_noise, "last data segment: %d", ft_last_data_segment);
+ TRACE(ft_t_noise, "header segments are %d and %d",
+ ft_header_segment_1, ft_header_segment_2);
+
+ /* Verify tape parameters...
+ * QIC-40/80 spec: tape_parameters:
+ *
+ * segments-per-track segments_per_track
+ * tracks-per-cartridge tracks_per_tape
+ * max-floppy-side (segments_per_track *
+ * tracks_per_tape - 1) /
+ * ftape_segments_per_head
+ * max-floppy-track ftape_segments_per_head /
+ * ftape_segments_per_cylinder - 1
+ * max-floppy-sector ftape_segments_per_cylinder *
+ * FT_SECTORS_PER_SEGMENT
+ */
+ ft_segments_per_track = GET2(address, FT_SPT);
+ ft_tracks_per_tape = address[FT_TPC];
+ max_floppy_side = address[FT_FHM];
+ max_floppy_track = address[FT_FTM];
+ max_floppy_sector = address[FT_FSM];
+ TRACE(ft_t_noise, "(fmt/spt/tpc/fhm/ftm/fsm) = %d/%d/%d/%d/%d/%d",
+ ft_format_code, ft_segments_per_track, ft_tracks_per_tape,
+ max_floppy_side, max_floppy_track, max_floppy_sector);
+ new_tape_len = ftape_tape_len;
+ switch (ft_format_code) {
+ case fmt_425ft:
+ new_tape_len = 425;
+ break;
+ case fmt_normal:
+ if (ftape_tape_len == 0) { /* otherwise 307 ft */
+ new_tape_len = 205;
+ }
+ break;
+ case fmt_1100ft:
+ new_tape_len = 1100;
+ break;
+ case fmt_var:{
+ int segments_per_1000_inch = 1; /* non-zero default for switch */
+ switch (ft_qic_std) {
+ case QIC_TAPE_QIC40:
+ segments_per_1000_inch = 332;
+ break;
+ case QIC_TAPE_QIC80:
+ segments_per_1000_inch = 488;
+ break;
+ case QIC_TAPE_QIC3010:
+ segments_per_1000_inch = 730;
+ break;
+ case QIC_TAPE_QIC3020:
+ segments_per_1000_inch = 1430;
+ break;
+ }
+ new_tape_len = (1000 * ft_segments_per_track +
+ (segments_per_1000_inch - 1)) / segments_per_1000_inch;
+ break;
+ }
+ case fmt_big:{
+ int segments_per_1000_inch = 1; /* non-zero default for switch */
+ switch (ft_qic_std) {
+ case QIC_TAPE_QIC40:
+ segments_per_1000_inch = 332;
+ break;
+ case QIC_TAPE_QIC80:
+ segments_per_1000_inch = 488;
+ break;
+ case QIC_TAPE_QIC3010:
+ segments_per_1000_inch = 730;
+ break;
+ case QIC_TAPE_QIC3020:
+ segments_per_1000_inch = 1430;
+ break;
+ default:
+ TRACE_ABORT(-EIO, ft_t_bug,
+ "%x QIC-standard with fmt-code %d, please report",
+ ft_qic_std, ft_format_code);
+ }
+ new_tape_len = ((1000 * ft_segments_per_track +
+ (segments_per_1000_inch - 1)) /
+ segments_per_1000_inch);
+ break;
+ }
+ default:
+ TRACE_ABORT(-EIO, ft_t_err,
+ "unknown tape format, please report !");
+ }
+ if (new_tape_len != ftape_tape_len) {
+ ftape_tape_len = new_tape_len;
+ TRACE(ft_t_info, "calculated tape length is %d ft",
+ ftape_tape_len);
+ ftape_calc_timeouts(ft_qic_std, ft_data_rate, ftape_tape_len);
+ }
+ if (ft_segments_per_track == 0 && ft_tracks_per_tape == 0 &&
+ max_floppy_side == 0 && max_floppy_track == 0 &&
+ max_floppy_sector == 0) {
+ /* QIC-40 Rev E and earlier has no values in the header.
+ */
+ ft_segments_per_track = 68;
+ ft_tracks_per_tape = 20;
+ max_floppy_side = 1;
+ max_floppy_track = 169;
+ max_floppy_sector = 128;
+ }
+ /* This test will compensate for the wrong parameter on tapes
+ * formatted by Conner software.
+ */
+ if (ft_segments_per_track == 150 &&
+ ft_tracks_per_tape == 28 &&
+ max_floppy_side == 7 &&
+ max_floppy_track == 149 &&
+ max_floppy_sector == 128) {
+TRACE(ft_t_info, "the famous CONNER bug: max_floppy_side off by one !");
+ max_floppy_side = 6;
+ }
+ /* These tests will compensate for the wrong parameter on tapes
+ * formatted by ComByte Windows software.
+ *
+ * First, for 205 foot tapes
+ */
+ if (ft_segments_per_track == 100 &&
+ ft_tracks_per_tape == 28 &&
+ max_floppy_side == 9 &&
+ max_floppy_track == 149 &&
+ max_floppy_sector == 128) {
+TRACE(ft_t_info, "the ComByte bug: max_floppy_side incorrect!");
+ max_floppy_side = 4;
+ }
+ /* Next, for 307 foot tapes. */
+ if (ft_segments_per_track == 150 &&
+ ft_tracks_per_tape == 28 &&
+ max_floppy_side == 9 &&
+ max_floppy_track == 149 &&
+ max_floppy_sector == 128) {
+TRACE(ft_t_info, "the ComByte bug: max_floppy_side incorrect!");
+ max_floppy_side = 6;
+ }
+ /* This test will compensate for the wrong parameter on tapes
+ * formatted by Colorado Windows software.
+ */
+ if (ft_segments_per_track == 150 &&
+ ft_tracks_per_tape == 28 &&
+ max_floppy_side == 6 &&
+ max_floppy_track == 150 &&
+ max_floppy_sector == 128) {
+TRACE(ft_t_info, "the famous Colorado bug: max_floppy_track off by one !");
+ max_floppy_track = 149;
+ }
+ ftape_segments_per_head = ((max_floppy_sector/FT_SECTORS_PER_SEGMENT) *
+ (max_floppy_track + 1));
+ /* This test will compensate for some bug reported by Dima
+ * Brodsky. Seems to be a Colorado bug, either. (freebee
+ * Imation tape shipped together with Colorado T3000
+ */
+ if ((ft_format_code == fmt_var || ft_format_code == fmt_big) &&
+ ft_tracks_per_tape == 50 &&
+ max_floppy_side == 54 &&
+ max_floppy_track == 255 &&
+ max_floppy_sector == 128) {
+TRACE(ft_t_info, "the famous ??? bug: max_floppy_track off by one !");
+ max_floppy_track = 254;
+ }
+ /*
+ * Verify drive_configuration with tape parameters
+ */
+ if (ftape_segments_per_head == 0 || ftape_segments_per_cylinder == 0 ||
+ ((ft_segments_per_track * ft_tracks_per_tape - 1) / ftape_segments_per_head
+ != max_floppy_side) ||
+ (ftape_segments_per_head / ftape_segments_per_cylinder - 1 != max_floppy_track) ||
+ (ftape_segments_per_cylinder * FT_SECTORS_PER_SEGMENT != max_floppy_sector)
+#ifdef TESTING
+ || ((ft_format_code == fmt_var || ft_format_code == fmt_big) &&
+ (max_floppy_track != 254 || max_floppy_sector != 128))
+#endif
+ ) {
+ char segperheadz = ftape_segments_per_head ? ' ' : '?';
+ char segpercylz = ftape_segments_per_cylinder ? ' ' : '?';
+ TRACE(ft_t_err,"Tape parameters inconsistency, please report");
+ TRACE(ft_t_err, "reported = %d/%d/%d/%d/%d/%d",
+ ft_format_code,
+ ft_segments_per_track,
+ ft_tracks_per_tape,
+ max_floppy_side,
+ max_floppy_track,
+ max_floppy_sector);
+ TRACE(ft_t_err, "required = %d/%d/%d/%d%c/%d%c/%d",
+ ft_format_code,
+ ft_segments_per_track,
+ ft_tracks_per_tape,
+ ftape_segments_per_head ?
+ ((ft_segments_per_track * ft_tracks_per_tape -1) /
+ ftape_segments_per_head ) :
+ (ft_segments_per_track * ft_tracks_per_tape -1),
+ segperheadz,
+ ftape_segments_per_cylinder ?
+ (ftape_segments_per_head /
+ ftape_segments_per_cylinder - 1 ) :
+ ftape_segments_per_head - 1,
+ segpercylz,
+ (ftape_segments_per_cylinder * FT_SECTORS_PER_SEGMENT));
+ TRACE_EXIT -EIO;
+ }
+ ftape_extract_bad_sector_map(address);
+ TRACE_EXIT 0;
+}
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