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/* $Id: tpqic02.c,v 1.1.1.1 2001-09-10 07:44:17 simons Exp $
 *
 * Driver for tape drive support for Linux-i386 1.1.58
 *
 * Copyright (c) 1992, 1993, 1994 by H. H. Bergman. All rights reserved.
 * Current e-mail address: hennus@sky.ow.org [This is a UUCP link.]
 * [If you are unable to reach me directly, try the TAPE mailing list
 * channel on linux-activists@niksula.hut.fi using "X-Mn-Key: TAPE" as
 * the first line in your message.]
 *
 * Distribution of this program in executable form is only allowed if
 * all of the corresponding source files are made available through the same
 * medium at no extra cost.
 *
 * I will not accept any responsibility for damage caused directly or
 * indirectly by this program, or code derived from this program.
 *
 * Use this code at your own risk. Don't blame me if it destroys your data!
 * Make sure you have a backup before you try this code.
 *
 * If you make changes to my code and redistribute it in source or binary
 * form you must make it clear to even casual users of your code that you
 * have modified my code, clearly point out what the changes exactly are
 * (preferably in the form of a context diff file), how to undo your changes,
 * where the original can be obtained, and that complaints/requests about the
 * modified code should be directed to you instead of me.
 *
 * This driver was partially inspired by the 'wt' driver in the 386BSD
 * source distribution, which carries the following copyright notice:
 *
 *  Copyright (c) 1991 The Regents of the University of California.
 *  All rights reserved.
 *
 * You are not allowed to change this line nor the text above.
 *
 * $Log: not supported by cvs2svn $
 * Revision 1.1.1.1  2001/07/02 17:58:25  simons
 * Initial revision
 *
 * Revision 0.4.1.5  1994/10/29  02:46:13  root
 * Minor cleanups.
 *
 * Revision 0.4.1.4  1994/07/21  02:15:45  root
 * ifdef'd DDI. Exception masks.
 *
 * Revision 0.4.1.3  1994/05/03  01:49:09  root
 * Initial attempt at Mountain support for the Mountain 7150.
 * Based on patches provided by Erik Jacobson.
 *
 * Revision 0.4.1.2  1994/03/18  21:16:50  root
 * Many driver messages can now be turned off (runtime selectable).
 *
 * Revision 0.4.1.1  1994/02/16  19:47:22  root
 * First stab at runtime debug-variable.
 *
 * Revision 0.4  1994/02/15  01:53:16  root
 * DYNCONF mark II.
 * Minor cleanups.
 *
 * Revision 0.3  1994/02/07  01:23:16  root
 * More improved DYNCONF.
 * Archive changes & some cleanups by Eddy Olk.
 * Removed status_open, more cleanups, misc other.
 *
 * Revision 0.2.1.25  1994/01/24  02:01:33  root
 * Changed tape_qic02 to QIC02_TAPE.
 * Changes to prepare for DYNCONF.
 *
 * Revision 0.2.1.24  1994/01/23  07:27:18  root
 * Attempt to remove compilation warnings, G++ bug,
 * Linus changed TAPE_QIC02 to QIC02_TAPE.
 *
 * Revision 0.2.1.23  1994/01/20  23:49:28  root
 * Changed some exception decoding stuff.
 * TP_HAVE_SEEK, TP_HAVE_DENS. byte_swap_w() on arg, not global.
 * Attempt to fix cartridge-changed-problem for 2150L.
 * Release irq and dma reservations if initial reset fails.
 *
 * Revision 0.2.1.22  1994/01/19  20:56:55  root
 * Speed measuring stuff moved from aperf.h to delay.h.
 * BogoMips (tm) introduced by Linus.
 *
 * Revision 0.2.1.21  1993/06/18  19:04:33  root
 * minor fixes for 0.99.10.
 *
 * Revision 0.2.1.20  1993/06/11  21:38:51  root
 * Added exception code for status 0x8000 (Cypher weirdness).
 *
 * Revision 0.2.1.19  1993/04/19  23:13:59  root
 * Cleanups. Changed to 0.99.8.
 *
 * Revision 0.2.1.18  1993/03/22  17:39:47  root
 * Moved to 0.99.7. Added Archive MTSEEK and MTTELL support.
 *
 * Revision 0.2.1.17  1993/03/08  18:51:59  root
 * Tried to `fix' write-once bug in previous release.
 *
 * Revision 0.2.1.16  1993/03/01  00:06:16  root
 * Use register_chrdev() for 0.99.6.
 *
 * Revision 0.2.1.15  1993/02/25  00:14:25  root
 * minor cleanups.
 *
 * Revision 0.2.1.14  1993/01/25  00:06:14  root
 * Kernel udelay. Eof fixups.
 * Removed report_ read/write dummies; have strace(1) now.
 *
 * Revision 0.2.1.13  1993/01/10  02:24:43  root
 * Rewrote wait_for_ready() to use newer schedule() features.
 * This improves performance for rewinds etc.
 *
 * Revision 0.2.1.12  1993/01/05  18:44:09  root
 * Changes for 0.99.1. Fixed `restartable reads'.
 *
 * Revision 0.2.1.11  1992/11/28  01:19:10  root
 * Changes to exception handling (significant).
 * Changed returned error codes. Hopefully they're correct now.
 * Changed declarations to please gcc-2.3.1.
 * Patch to deal with bogus interrupts for Archive cards.
 *
 * Revision 0.2.1.10  1992/10/28  00:50:44  root
 * underrun/error counter needed byte swapping.
 *
 * Revision 0.2.1.9  1992/10/15  17:06:01  root
 * Removed online() stuff. Changed EOF handling.
 *
 * Revision 0.2.1.8  1992/10/02  22:25:48  root
 * Removed `no_sleep' parameters (got usleep() now),
 * cleaned up some comments.
 *
 * Revision 0.2.1.7  1992/09/27  01:41:55  root
 * Changed write() to do entire user buffer in one go, rather than just
 * a kernel-buffer sized portion each time.
 *
 * Revision 0.2.1.6  1992/09/21  02:15:30  root
 * Introduced udelay() function for microsecond-delays.
 * Trying to use get_dma_residue rather than TC flags.
 * Patch to fill entire user buffer on reads before
 * returning.
 *
 * Revision 0.2.1.5  1992/09/19  02:31:28  root
 * Some changes based on patches by Eddy Olk to
 * support Archive SC402/SC499R controller cards.
 *
 * Revision 0.2.1.4  1992/09/07  01:37:37  root
 * Minor changes
 *
 * Revision 0.2.1.3  1992/08/13  00:11:02  root
 * Added some support for Archive SC402 and SC499 cards.
 * (Untested.)
 *
 * Revision 0.2.1.2  1992/08/10  02:02:36  root
 * Changed from linux/system.h macros to asm/dma.h inline functions.
 *
 * Revision 0.2.1.1  1992/08/08  01:12:39  root
 * cleaned up a bit. added stuff for selftesting.
 * preparing for asm/dma.h instead of linux/system.h
 *
 * Revision 0.2  1992/08/03  20:11:30  root
 * Changed to use new IRQ allocation. Padding now done at runtime, pads to
 * 512 bytes. Because of this the page regs must be re-programmed every
 * block! Added hooks for selftest commands.
 * Moved to linux-0.97.
 *
 * Revision 0.1.0.5  1992/06/22  22:20:30  root
 * moved to Linux 0.96b
 *
 * Revision 0.1.0.4  1992/06/18  02:00:04  root
 * Use minor bit-7 to enable/disable printing of extra debugging info
 * when do tape access.
 * Added semop stuff for DMA/IRQ allocation checking. Don't think this
 * is the right way to do it though.
 *
 * Revision 0.1.0.3  1992/06/01  01:57:34  root
 * changed DRQ to DMA. added TDEBUG ifdefs to reduce output.
 *
 * Revision 0.1.0.2  1992/05/31  14:02:38  root
 * changed SET_DMA_PAGE handling slightly.
 *
 * Revision 0.1.0.1  1992/05/27  12:12:03  root
 * Can now use multiple files on tape (sort of).
 * First release.
 *
 * Revision 0.1  1992/05/26  01:16:31  root
 * Initial version. Copyright H. H. Bergman 1992
 *
 */
 
/* After the legalese, now the important bits:
 *
 * This is a driver for the Wangtek 5150 tape drive with
 * a QIC-02 controller for ISA-PC type computers.
 * Hopefully it will work with other QIC-02 tape drives as well.
 *
 * Make sure your setup matches the configuration parameters.
 * Also, be careful to avoid IO conflicts with other devices!
 */
 
 
/*
#define TDEBUG
*/
 
#define REALLY_SLOW_IO          /* it sure is ... */
 
#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/major.h>
#include <linux/errno.h>
#include <linux/mtio.h>
#include <linux/fcntl.h>
#include <linux/delay.h>
#include <linux/tpqic02.h>
#include <linux/config.h>
#include <linux/mm.h>
 
#include <asm/dma.h>
#include <asm/system.h>
#include <asm/io.h>
#include <asm/segment.h>
 
/* We really shouldn't be using this define.. */
#define IOCCMD_MASK 0x0000ffff
 
/* check existence of required configuration parameters */
#if !defined(QIC02_CMD_PORT) || \
    !defined(QIC02_TAPE_IRQ) || \
    !defined(QIC02_TAPE_DMA)
#error qic02_tape configuration error
#endif
 
 
#define TPQIC02_NAME    "tpqic02"
 
/* Linux outb() commands have (value,port) as parameters.
 * One might expect (port,value) instead, so beware!
 */
 
#ifdef CONFIG_QIC02_DYNCONF
/* This holds the dynamic configuration info for the interface
 * card+drive info if runtime configuration has been selected.
 */
struct mtconfiginfo qic02_tape_dynconf = { 0, }; /* user settable */
struct qic02_ccb qic02_tape_ccb = { 0, };                /* private stuff */
 
#else
 
unsigned long qic02_tape_debug;
 
# if ((QIC02_TAPE_IFC!=WANGTEK) && (QIC02_TAPE_IFC!=ARCHIVE) && (QIC02_TAPE_IFC!=MOUNTAIN))
#  error No valid interface card specified
# endif
#endif
 
static volatile int ctlbits = 0;     /* control reg bits for tape interface */
 
static struct wait_queue *qic02_tape_transfer = NULL; /* sync rw with interrupts */
 
static volatile struct mtget ioctl_status;      /* current generic status */
 
static volatile struct tpstatus tperror;        /* last drive status */
 
static char rcs_revision[] = "$Revision: 1.1.1.1 $";
static char rcs_date[] = "$Date: 2001-09-10 07:44:17 $";
 
/* Flag bits for status and outstanding requests.
 * (Could all be put in one bit-field-struct.)
 * Some variables need `volatile' because they may be modified
 * by an interrupt.
 */
static volatile flag status_dead = YES; /* device is legally dead until proven alive */
static          flag status_zombie = YES; /* it's `zombie' until irq/dma allocated */
 
static volatile flag status_bytes_wr = NO;      /* write FM at close or not */
static volatile flag status_bytes_rd = NO;      /* (rd|wr) used for rewinding */
 
static volatile unsigned long status_cmd_pending = 0; /* cmd in progress */
static volatile flag status_expect_int = NO;    /* ready for interrupts */
static volatile flag status_timer_on = NO;      /* using time-out */
static volatile int  status_error = 0;           /* int handler may detect error */
static volatile flag status_eof_detected = NO;  /* end of file */
static volatile flag status_eom_detected = NO;  /* end of recorded media */
static volatile flag status_eot_detected = NO;  /* end of tape */
static volatile flag doing_read = NO;
static volatile flag doing_write = NO;
 
static volatile unsigned long dma_bytes_todo;
static volatile unsigned long dma_bytes_done;
static volatile unsigned dma_mode = 0;           /* !=0 also means DMA in use */
static          flag need_rewind = YES;
 
static kdev_t current_tape_dev;
static int extra_blocks_left = BLOCKS_BEYOND_EW;
 
 
/* return_*_eof:
 *      NO:     not at EOF,
 *      YES:    tell app EOF was reached (return 0).
 *
 * return_*_eof==YES && reported_*_eof==NO  ==>
 *      return current buffer, next time(s) return EOF.
 *
 * return_*_eof==YES && reported_*_eof==YES  ==>
 *      at EOF and application knows it, so we can
 *      move on to the next file.
 *
 */
static flag return_read_eof = NO;       /* set to signal app EOF was reached */
static flag return_write_eof = NO;
static flag reported_read_eof = NO;     /* set when we've done that */
static flag reported_write_eof = NO;
 
 
/* This is for doing `mt seek <blocknr>' */
static char seek_addr_buf[AR_SEEK_BUF_SIZE];
 
 
/* In write mode, we have to write a File Mark after the last block written,
 * when the tape device is closed. Tape repositioning and reading in write
 * mode is allowed as long as no actual writing has been done. After writing
 * the File Mark, repositioning and reading are allowed again.
 */
static int  mode_access;        /* access mode: READ or WRITE */
 
 
/* This is the actual kernel buffer where the interrupt routines read
 * from/write to. It is needed because the DMA channels 1 and 3 cannot
 * always access the user buffers. [The kernel buffer must reside in the
 * lower 16MBytes of system memory because of the DMA controller.]
 * The user must ensure that a large enough buffer is passed to the
 * kernel, in order to reduce tape repositioning.
 *
 * The buffer is 512 bytes larger than expected, because I want to align it
 * at 512 bytes, to prevent problems with 64k boundaries.
 */
 
static volatile char qic02_tape_buf[TPQBUF_SIZE+TAPE_BLKSIZE];
/* A really good compiler would be able to align this at 512 bytes... :-( */
 
static unsigned long buffaddr;  /* aligned physical address of buffer */
 
 
/* This translates minor numbers to the corresponding recording format: */
static const char *format_names[] = {
        "not set",      /* for dumb drives unable to handle format selection */
        "11",           /* extinct */
        "24",
        "120",
        "150",
        "300",          /* untested. */
        "600"           /* untested. */
};
 
 
/* `exception_list' is needed for exception status reporting.
 * Exceptions 1..14 are defined by QIC-02 rev F.
 * The drive status is matched sequentially to each entry,
 * ignoring irrelevant bits, until a match is found. If no
 * match is found, exception number 0 is used. (That should of
 * course never happen...) The original table was based on the
 * "Exception Status Summary" in QIC-02 rev F, but some changes
 * were required to make it work with real-world drives.
 *
 * Exception 2 (CNI) is changed to also cover status 0x00e0 (mask USL),
 * Exception 4 (EOM) is changed to also cover status 0x8288 (mask EOR),
 * Exception 11 (FIL) is changed to also cover status 0x0089 (mask EOM).
 * Exception 15 (EOR) is added for seek-to-end-of-data (catch EOR),
 * Exception 16 (BOM) is added for beginning-of-media (catch BOM).
 *
 * Had to swap EXC_NDRV and EXC_NCART to ensure that extended EXC_NCART
 * (because of the incorrect Wangtek status code) doesn't catch the
 * EXC_NDRV first.
 */
static struct exception_list_type {
        unsigned short mask, code;
        const char *msg;
        /* EXC_nr attribute should match with tpqic02.h */
} exception_list[] = {
        {0, 0,
                "Unknown exception status code",                /* extra: 0 */},
        {~(0), TP_ST0|TP_CNI|TP_USL|TP_WRP,
                "Drive not online"                              /* 1 */},
                /* Drive presence goes before cartridge presence. */
        {~(TP_WRP|TP_USL), TP_ST0|TP_CNI,
                /* My Wangtek 5150EQ sometimes reports a status code
                 * of 0x00e0, which is not a valid exception code, but
                 * I think it should be recognized as "NO CARTRIDGE".
                 */
                "Cartridge not in place"                        /* 2 */},
        {(unsigned short) ~(TP_ST1|TP_BOM), (TP_ST0|TP_WRP),
                "Write protected cartridge"                     /* 3 */},
        {(unsigned short) ~(TP_ST1|TP_EOR), (TP_ST0|TP_EOM),
                "End of media"                                  /* 4 */},
        {~TP_WRP, TP_ST0|TP_UDA| TP_ST1|TP_BOM,
                "Read or Write abort. Rewind tape."             /* 5 */},
        {~TP_WRP, TP_ST0|TP_UDA,
                "Read error. Bad block transferred."            /* 6 */},
        {~TP_WRP, TP_ST0|TP_UDA|TP_BNL,
                "Read error. Filler block transferred."         /* 7 */},
        {~TP_WRP, TP_ST0|TP_UDA|TP_BNL |TP_ST1|TP_NDT,
                "Read error. No data detected."                 /* 8 */},
        {~TP_WRP, TP_ST0|TP_EOM|TP_UDA|TP_BNL |TP_ST1|TP_NDT,
                "Read error. No data detected. EOM."            /* 9 */},
        {~(TP_WRP|TP_MBD|TP_PAR|TP_EOR), TP_ST0|TP_UDA|TP_BNL |TP_ST1|TP_NDT|TP_BOM,
                "Read error. No data detected. BOM."            /* 10 */},
        {~(TP_WRP|TP_EOM), TP_ST0|TP_FIL,
                /* Status 0x0089 (EOM & FM) is viewed as an FM,
                 * because it can only happen during a read.
                 * EOM is checked separately for an FM condition.
                 */
                "File mark detected"                            /* 11 */},
        {~(TP_ST0|TP_CNI|TP_USL|TP_WRP|TP_BOM), TP_ST1|TP_ILL,
                "Illegal command"                               /* 12 */},
        {~(TP_ST0|TP_CNI|TP_USL|TP_WRP|TP_BOM), TP_ST1|TP_POR,
                "Reset occurred"                                        /* 13 */},
        {~TP_WRP, TP_ST0|TP_FIL|TP_MBD,         /* NOTE: ST1 not set! */
                "Marginal block detected"                       /* 14 */},
        {~(TP_ST0|TP_WRP|TP_EOM|TP_UDA|TP_BNL|TP_FIL |TP_NDT), TP_ST1|TP_EOR,
                /********** Is the extra TP_NDT really needed Eddy? **********/
                "End of recorded media"                         /* extra: 15 */},
                /* 15 is returned when SEEKEOD completes successfully */
        {~(TP_WRP|TP_ST0), TP_ST1|TP_BOM,
                "Beginning of media"                            /* extra: 16 */}
};
#define NR_OF_EXC       (sizeof(exception_list)/sizeof(struct exception_list_type))
 
 
 
static void tpqputs(unsigned long flags, const char *s)
{
        if ((flags & TPQD_ALWAYS) || (flags & QIC02_TAPE_DEBUG))
                printk(TPQIC02_NAME ": %s\n", s);
} /* tpqputs */
 
 
 
 
/* Perform byte order swapping for a 16-bit word.
 *
 * [FIXME] This should probably be in include/asm/
 * ([FIXME] i486 can do this faster)
 */
static inline void byte_swap_w(volatile unsigned short * w)
{
        int t = *w;
 
        *w = (t>>8) | ((t & 0xff)<<8);
}
 
 
 
/* Init control register bits on interface card.
 * For Archive, interrupts must be enabled explicitly.
 * Wangtek interface card requires ONLINE to be set, Archive SC402/SC499R
 * cards keep it active all the time.
 */
static void ifc_init(void)
{
        if (QIC02_TAPE_IFC == WANGTEK) /* || (QIC02_TAPE_IFC == EVEREX) */ {
                ctlbits = WT_CTL_ONLINE;        /* online */
                outb_p(ctlbits, QIC02_CTL_PORT);
 
        } else if (QIC02_TAPE_IFC == ARCHIVE) {
                ctlbits = 0;                     /* no interrupts yet */
                outb_p(ctlbits, QIC02_CTL_PORT);
                outb_p(0, AR_RESET_DMA_PORT);    /* dummy write to reset DMA */
 
        } else /* MOUNTAIN */ {
                ctlbits = MTN_CTL_ONLINE;       /* online, and logic enabled */
                outb_p(ctlbits, QIC02_CTL_PORT);
        }
} /* ifc_init */
 
 
static void report_exception(unsigned n)
{
        if (n >= NR_OF_EXC) { tpqputs(TPQD_ALWAYS, "Oops -- report_exception"); n = 0; }
        if (TPQDBG(SENSE_TEXT) || n==0)
                printk(TPQIC02_NAME ": sense: %s\n", exception_list[n].msg);
} /* report_exception */
 
 
/* Try to map the drive-exception bits `s' to a predefined "exception number",
 * by comparing the significant exception bits for each entry in the
 * exception table (`exception_list[]').
 * It is assumed that s!=0.
 */
static int decode_exception_nr(unsigned s)
{
        int i;
 
        for (i=1; i<NR_OF_EXC; i++) {
                if ((s & exception_list[i].mask)==exception_list[i].code)
                        return i;
        }
        printk(TPQIC02_NAME ": decode_exception_nr: exception(%x) not recognized\n", s);
        return 0;
} /* decode_exception_nr */
 
 
#ifdef OBSOLETE
/* There are exactly 14 possible exceptions, as defined in QIC-02 rev F.
 * Some are FATAL, some aren't. Currently all exceptions are treated as fatal.
 * Especially 6 and 14 should not abort the transfer. RSN...
 * Should probably let sense() figure out the exception number using the code
 * below, and just report the error based on the number here, returning a code
 * for FATAL/CONTINUABLE.
 */
static void report_error(int s)
{
        short n = -1;
 
        if (s & TP_ST1) {
                if (s & TP_ILL)         /* 12: Illegal command. FATAL */
                        n = 12;
                if (s & TP_POR)         /* 13: Reset occurred. FATAL */
                        n = 13;
        }
        else if (s & TP_ST0) {
                if (s & TP_EOR) {       /* extra: 15: End of Recorded Media. CONTINUABLE */
                        n = 15;
                        /********** should set flag here **********/
                }
                else if (s & TP_EOM)            /* 4: End Of Media. CONTINUABLE */
                        n = 4;
                else if (s & TP_USL)            /* 2: Drive not online. FATAL */
                        n = 2;
                else if (s & TP_CNI) {  /* 1: Cartridge not in place. FATAL */
                        n = 1;
                        need_rewind = YES;
                        status_eof_detected = NO;
                        status_eom_detected = NO;
                }
                else if (s & TP_UDA) {
                        if (s & TP_BNL) {
                                if (s & TP_NDT) {
                                        if (s & TP_BOM)         /* 9: Read error. No data detected & EOM. CONTINUABLE */
                                                n = 9;
                                        else if (s & TP_EOM)    /* 10: Read error. No data detected & BOM. CONTINUABLE */
                                                n = 10;
                                        else                    /* 8: Read error. No data detected. CONTINUABLE */
                                                n = 8;
                                } else { /* 7: Read error. Cannot recover block, filler substituted. CONTINUABLE */
                                        tpqputs(TPQD_ALWAYS, "[Bad block -- filler data transferred.]");
                                        n = 7;
                                }
                        }
                        else {
                                if (s & TP_EOM) /* 5: Read or Write error. Rewind tape. FATAL */
                                        n = 5;
                                else {          /* 6: Read error. Bad block transferred. CONTINUABLE */
                                        /* block is bad, but transfer may continue.
                                         * This is why some people prefer not to
                                         * use compression on backups...
                                         */
                                        tpqputs(TPQD_ALWAYS, "[CRC failed!]");
                                        n = 6;
                                }
                        }
                }
                else if (s & TP_FIL) {
                        if (s & TP_MBD) {       /* 14: Marginal block detected. CONTINUABLE */
                                tpqputs(TPQD_ALWAYS, "[Marginal block]");
                                n = 14;
                        } else                  /* 11: File mark detected. CONTINUABLE */
                                n = 11;
                }
                else if (s & TP_WRP)            /* 3: Write protected cartridge. FATAL */
                        n = 3;
        }
        if (n >= 0)
                sensemsg(n);
} /* report_error */
#endif
 
 
/* Perform appropriate action for certain exceptions.
 * should return a value to indicate stop/continue (in case of bad blocks)
 */
static void handle_exception(int exnr, int exbits)
{
        if (exnr==EXC_NCART) {
                /* Cartridge was changed. Redo sense().
                 * EXC_NCART should be handled in open().
                 * It is not permitted to remove the tape while
                 * the tape driver has open files.
                 */
                need_rewind = YES;
                status_eof_detected = NO;
                status_eom_detected = NO;
        }
        else if (exnr==EXC_XFILLER)
                tpqputs(TPQD_ALWAYS, "[Bad block -- filler data transferred.]");
        else if (exnr==EXC_XBAD)
                tpqputs(TPQD_ALWAYS, "[CRC failed!]");
        else if (exnr==EXC_MARGINAL) {
                /* A marginal block behaves much like a FM.
                 * User may continue reading, if desired.
                 */
                tpqputs(TPQD_ALWAYS, "[Marginal block]");
                doing_read = NO;
        } else if (exnr==EXC_FM)
                doing_read = NO;
} /* handle_exception */
 
 
static inline int is_exception(void)
{
        return (inb(QIC02_STAT_PORT) & QIC02_STAT_EXCEPTION) == 0;
} /* is_exception */
 
 
/* Reset the tape drive and controller.
 * When reset fails, it marks  the drive as dead and all
 * requests (except reset) are to be ignored (ENXIO).
 */
static int tape_reset(int verbose)
{
        ifc_init();                             /* reset interface card */
 
        /* assert reset */
        if (QIC02_TAPE_IFC == MOUNTAIN)
                outb_p(ctlbits & ~MTN_QIC02_CTL_RESET_NOT, QIC02_CTL_PORT);
        else /* WANGTEK, ARCHIVE */
                outb_p(ctlbits | QIC02_CTL_RESET, QIC02_CTL_PORT);
 
        /* Next, we need to wait >=25 usec. */
        udelay(30);
 
        /* after reset, we will be at BOT (modulo an automatic rewind) */
        status_eof_detected = NO;
        status_eom_detected = NO;
        status_cmd_pending = 0;
        need_rewind = YES;
        doing_read = doing_write = NO;
        ioctl_status.mt_fileno = ioctl_status.mt_blkno = 0;
 
        /* de-assert reset */
        if (QIC02_TAPE_IFC == MOUNTAIN)
                outb_p(ctlbits | MTN_QIC02_CTL_RESET_NOT, QIC02_CTL_PORT);
        else
                outb_p(ctlbits & ~QIC02_CTL_RESET, QIC02_CTL_PORT);
 
        /* KLUDGE FOR G++ BUG */
        { int stat = inb_p(QIC02_STAT_PORT);
          status_dead = ((stat & QIC02_STAT_RESETMASK) != QIC02_STAT_RESETVAL); }
        /* if successful, inb(STAT) returned RESETVAL */
        if (status_dead == YES)
                printk(TPQIC02_NAME ": reset failed!\n");
        else if (verbose)
                printk(TPQIC02_NAME ": reset successful\n");
 
        return (status_dead == YES)? TE_DEAD : TE_OK;
} /* tape_reset */
 
 
 
/* Notify tape drive of a new command. It only waits for the
 * command to be accepted, not for the actual command to complete.
 *
 * Before calling this routine, QIC02_CMD_PORT must have been loaded
 * with the command to be executed.
 * After this routine, the exception bit must be checked.
 * This routine is also used by rdstatus(), so in that case, any exception
 * must be ignored (`ignore_ex' flag).
 */
static int notify_cmd(char cmd, short ignore_ex)
{
        int i;
 
        outb_p(cmd, QIC02_CMD_PORT);    /* output the command */
 
        /* wait 1 usec before asserting /REQUEST */
        udelay(1);
 
        if ((!ignore_ex) && is_exception()) {
                tpqputs(TPQD_ALWAYS, "*** exception detected in notify_cmd");
                /** force a reset here **/
                if (tape_reset(1)==TE_DEAD)
                        return TE_DEAD;
                if (is_exception()) {
                        tpqputs(TPQD_ALWAYS, "exception persists after reset.");
                        tpqputs(TPQD_ALWAYS, " ^ exception ignored.");
                }
        }
 
        outb_p(ctlbits | QIC02_CTL_REQUEST, QIC02_CTL_PORT);  /* set request bit */
        i = TAPE_NOTIFY_TIMEOUT;
        /* The specs say this takes about 500 usec, but there is no upper limit!
         * If the drive were busy retensioning or something like that,
         * it could be *much* longer!
         */
        while ((inb_p(QIC02_STAT_PORT) & QIC02_STAT_READY) && (--i>0))
                /*skip*/;                         /* wait for ready */
        if (i==0) {
                tpqputs(TPQD_ALWAYS, "timed out waiting for ready in notify_cmd");
                status_dead = YES;
                return TE_TIM;
        }
 
        outb_p(ctlbits & ~QIC02_CTL_REQUEST, QIC02_CTL_PORT); /* reset request bit */
        i = TAPE_NOTIFY_TIMEOUT;
        /* according to the specs this one should never time-out */
        while (((inb_p(QIC02_STAT_PORT) & QIC02_STAT_READY) == 0) && (--i>0))
                /*skip*/;                         /* wait for not ready */
        if (i==0) {
                tpqputs(TPQD_ALWAYS, "timed out waiting for !ready in notify_cmd");
                status_dead = YES;
                return TE_TIM;
        }
        /* command accepted */
        return TE_OK;
} /* notify_cmd */
 
 
 
/* Wait for a command to complete, with timeout */
static int wait_for_ready(time_t timeout)
{
        int stat;
        time_t spin_t;
 
        /* Wait for ready or exception, without driving the loadavg up too much.
         * In most cases, the tape drive already has READY asserted,
         * so optimize for that case.
         *
         * First, busy wait a few usec:
         */
        spin_t = 50;
        while (((stat = inb_p(QIC02_STAT_PORT) & QIC02_STAT_MASK) == QIC02_STAT_MASK) && (--spin_t>0))
                /*SKIP*/;
        if ((stat & QIC02_STAT_READY) == 0)
                return TE_OK;                   /* covers 99.99% of all calls */
 
        /* Then use schedule() a few times */
        spin_t = 3;     /* max 0.03 sec busy waiting */
        if (spin_t > timeout)
                spin_t = timeout;
        timeout -= spin_t;
        spin_t += jiffies;
 
        while (((stat = inb_p(QIC02_STAT_PORT) & QIC02_STAT_MASK) == QIC02_STAT_MASK) && (jiffies<spin_t))
                schedule();             /* don't waste all the CPU time */
        if ((stat & QIC02_STAT_READY) == 0)
                return TE_OK;
 
        /* If we reach this point, we probably need to wait much longer, or
         * an exception occurred. Either case is not very time-critical.
         * Check the status port only a few times every second.
         * A interval of less than 0.10 sec will not be noticed by the user,
         * more than 0.40 sec may give noticeable delays.
         */
        spin_t += timeout;
        TPQDEB({printk("wait_for_ready: additional timeout: %d\n", spin_t);})
 
                /* not ready and no exception && timeout not expired yet */
        while (((stat = inb_p(QIC02_STAT_PORT) & QIC02_STAT_MASK) == QIC02_STAT_MASK) && (jiffies<spin_t)) {
                /* be `nice` to other processes on long operations... */
                current->timeout = jiffies + 3*HZ/10;   /* nap 0.30 sec between checks, */
                current->state = TASK_INTERRUPTIBLE;
                schedule();              /* but could be woken up earlier by signals... */
        }
 
        /* don't use jiffies for this test because it may have changed by now */
        if ((stat & QIC02_STAT_MASK) == QIC02_STAT_MASK) {
                tpqputs(TPQD_ALWAYS, "wait_for_ready() timed out");
                return TE_TIM;
        }
 
        if ((stat & QIC02_STAT_EXCEPTION) == 0) {
                tpqputs(TPQD_ALWAYS, "exception detected after waiting_for_ready");
                return TE_EX;
        } else {
                return TE_OK;
        }
} /* wait_for_ready */
 
 
 
/* Send some data to the drive */
static int send_qic02_data(char sb[], unsigned size, int ignore_ex)
{
        int i, stat;
 
        for (i=0; i<size; i++) {
 
                stat = wait_for_ready(TIM_S);
                if (stat != TE_OK)
                        return stat;
 
                stat = notify_cmd(sb[i], ignore_ex);
                if (stat != TE_OK)
                        return stat;
        }
        return TE_OK;
 
} /* send_qic02_data */
 
 
/* Send a QIC-02 command (`cmd') to the tape drive, with
 * a time-out (`timeout').
 * This one is also used by tp_sense(), so we must have
 * a flag to disable exception checking (`ignore_ex').
 *
 * On entry, the controller is supposed to be READY.
 */
static int send_qic02_cmd(int cmd, time_t timeout, int ignore_ex)
{
        int stat;
 
        stat = inb_p(QIC02_STAT_PORT);
        if ((stat & QIC02_STAT_EXCEPTION) == 0) {        /* if exception */
                tpqputs(TPQD_ALWAYS, "send_qic02_cmd: Exception!");
                return TE_EX;
        }
        if (stat & QIC02_STAT_READY) {                  /* if not ready */
                tpqputs(TPQD_ALWAYS, "send_qic02_cmd: not Ready!");
                return TE_ERR;
        }
 
        /* assert(ready & !exception) */
 
        /* Remember current command for later re-use with dma transfers.
         * (For reading/writing multiple blocks.)
         */
        status_cmd_pending = cmd;
 
        stat = notify_cmd(cmd, ignore_ex); /* tell drive new command was loaded, */
                                           /* inherit exception check. */
        if (TP_HAVE_SEEK && (cmd == AR_QCMDV_SEEK_BLK)) {
                /* This one needs to send 3 more bytes, MSB first */
                stat = send_qic02_data(seek_addr_buf, sizeof(seek_addr_buf), ignore_ex);
        }
 
        if (stat != TE_OK) {
                tpqputs(TPQD_ALWAYS, "send_qic02_cmd failed");
        }
        return stat;
} /* send_qic02_cmd */
 
 
 
/* Get drive status. Assume drive is ready or has exception set.
 * (or will be in <1000 usec.)
 * Extra parameters added because of 'Read Extended Status 3' command.
 */
static int rdstatus(char *stp, unsigned size, char qcmd)
{
        int     s, n;
        char    *q = stp;
 
        /* Try to busy-wait a few (700) usec, after that de-schedule.
         *
         * The problem is, if we don't de-schedule, performance will
         * drop to zero when the drive is not responding and if we
         * de-schedule immediately, we waste a lot of time because a
         * task switch is much longer than we usually have to wait here.
         */
        n = 1000;       /* 500 is not enough on a 486/33 */
        while ((n>0) && ((inb_p(QIC02_STAT_PORT) & QIC02_STAT_MASK) == QIC02_STAT_MASK))
                n--;  /* wait for ready or exception or timeout */
        if (n==0) {
                /* n (above) should be chosen such that on your machine
                 * you rarely ever see the message below, and it should
                 * be small enough to give reasonable response time.]
                 */
                tpqputs(TPQD_ALWAYS, "waiting looong in rdstatus() -- drive dead?");
                while ((inb_p(QIC02_STAT_PORT) & QIC02_STAT_MASK) == QIC02_STAT_MASK)
                        schedule();
                tpqputs(TPQD_ALWAYS, "finished waiting in rdstatus()");
        }
 
        (void) notify_cmd(qcmd, 1);                     /* send read status command */
        /* ignore return code -- should always be ok, STAT may contain
         * exception flag from previous exception which we are trying to clear.
         */
 
        if (TP_DIAGS(current_tape_dev))
                printk(TPQIC02_NAME ": reading status bytes: ");
 
        for (q=stp; q<stp+size; q++)
        {
                do s = inb_p(QIC02_STAT_PORT);
                while ((s & QIC02_STAT_MASK) == QIC02_STAT_MASK);       /* wait for ready or exception */
 
                if ((s & QIC02_STAT_EXCEPTION) == 0) {           /* if exception */
                        tpqputs(TPQD_ALWAYS, "rdstatus: exception error");
                        ioctl_status.mt_erreg = 0;               /* dunno... */
                        return TE_NS;                           /* error, shouldn't happen... */
                }
 
                *q = inb_p(QIC02_DATA_PORT);                    /* read status byte */
 
                if (TP_DIAGS(current_tape_dev))
                        printk("[%1d]=0x%x  ", q-stp, (unsigned) (*q) & 0xff);
 
                outb_p(ctlbits | QIC02_CTL_REQUEST, QIC02_CTL_PORT);    /* set request */
 
                while ((inb_p(QIC02_STAT_PORT) & QIC02_STAT_READY) == 0);        /* wait for not ready */
 
                udelay(22);     /* delay >20 usec */
 
                outb_p(ctlbits & ~QIC02_CTL_REQUEST, QIC02_CTL_PORT);   /* un-set request */
 
        }
 
        /* Specs say we should wait for READY here.
         * My drive doesn't seem to need it here yet, but others do?
         */
        while (inb_p(QIC02_STAT_PORT) & QIC02_STAT_READY)
                /*skip*/;                         /* wait for ready */
 
        if (TP_DIAGS(current_tape_dev))
                printk("\n");
 
        return TE_OK;
} /* rdstatus */
 
 
 
/* Get standard status (6 bytes).
 * The `.dec' and `.urc' fields are in MSB-first byte-order,
 * so they have to be swapped first.
 */
static int get_status(volatile struct tpstatus *stp)
{
        int stat = rdstatus((char *) stp, TPSTATSIZE, QCMD_RD_STAT);
#if defined(i386) || defined(i486)
        byte_swap_w(&(stp->dec));
        byte_swap_w(&(stp->urc));
#else
        /* should probably swap status bytes #definition */
#endif
        return stat;
} /* get_status */
 
 
#if 0
/* This fails for my Wangtek drive */
/* get "Extended Status Register 3" (64 bytes)
 *
 * If the meaning of the returned bytes were known, the MT_TYPE
 * identifier could be used to decode them, since they are
 * "vendor unique". :-(
 */
static int get_ext_status3(void)
{
        char vus[64];   /* vendor unique status */
        int stat, i;
 
        tpqputs(TPQD_ALWAYS, "Attempting to read Extended Status 3...");
        stat = rdstatus(vus, sizeof(vus), QCMD_RD_STAT_X3);
        if (stat != TE_OK)
                return stat;
 
        tpqputs(TPQD_ALWAYS, "Returned status bytes:");
        for (i=0; i<sizeof(vus); i++) {
                if ( i % 8 == 0 )
                        printk("\n" TPQIC02_NAME ": %2d:");
                printk(" %2x", vus[i] & 0xff);
        }
        printk("\n");
 
        return TE_OK;
} /* get_ext_status3 */
#endif
 
 
/* Read drive status and set generic status too.
 * NOTE: Once we do a tp_sense(), read/write transfers are killed.
 */
static int tp_sense(int ignore)
{
        unsigned err = 0, exnr = 0, gs = 0;
        static void finish_rw(int cmd);
 
        if (TPQDBG(SENSE_TEXT))
                printk(TPQIC02_NAME ": tp_sense(ignore=0x%x) enter\n", ignore);
 
        /* sense() is not allowed during a read or write cycle */
        if (doing_write == YES)
                tpqputs(TPQD_ALWAYS, "Warning: File Mark inserted because of sense() request");
        /* The extra test is to avoid calling finish_rw during booting */
        if ((doing_read!=NO) || (doing_write!=NO))
                finish_rw(QCMD_RD_STAT);
 
        if (get_status(&tperror) != TE_OK) {
                tpqputs(TPQD_ALWAYS, "tp_sense: could not read tape drive status");
                return TE_ERR;
        }
 
        err = tperror.exs;      /* get exception status bits */
        if (err & (TP_ST0|TP_ST1))
                printk(TPQIC02_NAME ": tp_sense: status: %x, error count: %d, underruns: %d\n",
                        tperror.exs, tperror.dec, tperror.urc);
        else if ((tperror.dec!=0) || (tperror.urc!=0) || TPQDBG(SENSE_CNTS))
                printk(TPQIC02_NAME ": tp_sense: no hard errors, soft error count: %d, underruns: %d\n",
                        tperror.dec, tperror.urc);
 
        /* Set generic status. HP-UX defines these, but some extra would
         * be useful. Problem is to remain compatible. [Do we want to be
         * compatible??]
         */
        if (err & TP_ST0) {
                if (err & TP_CNI)               /* no cartridge */
                        gs |= GMT_DR_OPEN(-1);
                if (status_dead == NO)
                        gs |= GMT_ONLINE(-1);   /* always online */
                if (err & TP_USL)               /* not online */
                        gs &= ~GMT_ONLINE(-1);
                if (err & TP_WRP)
                        gs |= GMT_WR_PROT(-1);
                if (err & TP_EOM) {             /* end of media */
                        gs |= GMT_EOT(-1);      /* not sure this is correct for writes */
                        status_eom_detected = YES;
                        /* I don't know whether drive always reports EOF at or before EOM. */
                        status_eof_detected = YES;
                }
                /** if (err & TP_UDA) "Unrecoverable data error" **/
                /** if (err & TP_BNL) "Bad block not located" **/
                if (err & TP_FIL) {
                        gs |= GMT_EOF(-1);
                        status_eof_detected = YES;
                }
        }
        if (err & TP_ST1) {
                /** if (err & TP_ILL) "Illegal command" **/
                /** if (err & TP_NDT) "No data detected" **/
                /** if (err & TP_MBD) "Marginal block detected" **/
                if (err & TP_BOM)
                        gs |= GMT_BOT(-1);      /* beginning of tape */
        }
        ioctl_status.mt_gstat = gs;
        ioctl_status.mt_dsreg = tperror.exs;    /* "drive status" */
        ioctl_status.mt_erreg = tperror.dec;    /* "sense key error" */
 
        if (err & (TP_ST0|TP_ST1)) {
                /* My Wangtek occasionally reports `status' 1212 which should be ignored. */
                exnr = decode_exception_nr(err);
                handle_exception(exnr, err);            /* update driver state wrt drive status */
                report_exception(exnr);
        }
        err &= ~ignore;         /* mask unwanted errors -- not the correct way, use exception nrs?? */
        if (((err & TP_ST0) && (err & REPORT_ERR0)) ||
            ((err & TP_ST1) && (err & REPORT_ERR1)))
                return TE_ERR;
        return TE_OK;
} /* tp_sense */
 
 
 
/* Wait for a wind or rewind operation to finish or
 * to time-out. (May take very long).
 */
static int wait_for_rewind(time_t timeout)
{
        int stat;
 
        stat = inb(QIC02_STAT_PORT) & QIC02_STAT_MASK;
        if (TPQDBG(REWIND))
                printk(TPQIC02_NAME ": Waiting for (re-)wind to finish: stat=0x%x\n", stat);
 
        stat = wait_for_ready(timeout);
 
        if (stat != TE_OK) {
                        tpqputs(TPQD_ALWAYS, "(re-) winding failed\n");
        }
        return stat;
} /* wait_for_rewind */
 
 
 
/* Perform a full QIC02 command, and wait for completion,
 * check status when done. Complain about exceptions.
 *
 * This function should return an OS error code when
 * something goes wrong, 0 otherwise.
 */
static int ll_do_qic_cmd(int cmd, time_t timeout)
{
        int stat;
 
        if (status_dead == YES) {
                tpqputs(TPQD_ALWAYS, "Drive is dead. Do a `mt reset`.");
                return -ENXIO;                  /* User should do an MTRESET. */
        }
 
        stat = wait_for_ready(timeout);         /* wait for ready or exception */
        if (stat == TE_EX) {
                if (tp_sense(TP_WRP|TP_BOM|TP_EOM|TP_FIL)!=TE_OK)
                        return -EIO;
                /* else nothing to worry about, I hope */
                stat = TE_OK;
        }
        if (stat != TE_OK) {
                printk(TPQIC02_NAME ": ll_do_qic_cmd(%x, %ld) failed\n", cmd, (long) timeout);
                return -EIO;
        }
 
 
#if OBSOLETE
        /* wait for ready since it may not be active immediately after reading status */
        while ((inb_p(QIC02_STAT_PORT) & QIC02_STAT_READY) != 0);
#endif
 
        stat = send_qic02_cmd(cmd, timeout, 0);  /* (checks for exceptions) */
 
        if (cmd==QCMD_RD_FM) {
                status_eof_detected = NO;
                ioctl_status.mt_fileno++;
                /* Should update block count as well, but can't.
                 * Can do a `read address' for some drives, when MTNOP is done.
                 */
        } else if (cmd==QCMD_WRT_FM) {
                status_eof_detected = NO;
                ioctl_status.mt_fileno++;
        } else if ((cmd==QCMD_REWIND) || (cmd==QCMD_ERASE) || (cmd==QCMD_RETEN)) {
                status_eof_detected = NO;
                status_eom_detected = NO;
                status_eot_detected = NO;
                need_rewind = NO;
                ioctl_status.mt_fileno = ioctl_status.mt_blkno = 0;
                extra_blocks_left = BLOCKS_BEYOND_EW;
                return_write_eof = NO;
                return_read_eof = NO;
                reported_read_eof = NO;
                reported_write_eof = NO;
        }
        /* sense() will set eof/eom as required */
        if (stat==TE_EX) {
                if (tp_sense(TP_WRP|TP_BOM|TP_EOM|TP_FIL)!=TE_OK) {
                        printk(TPQIC02_NAME ": Exception persist in ll_do_qic_cmd[1](%x, %ld)", cmd, (long) timeout);
                        status_dead = YES;
                        return -ENXIO;
                        /* if rdstatus fails too, we're in trouble */
                }
        }
        else if (stat!=TE_OK) {
                printk(TPQIC02_NAME ": ll_do_qic_cmd: send_qic02_cmd failed, stat = 0x%x\n", stat);
                return -EIO;    /*** -EIO is probably not always appropriate */
        }
 
 
        if (timeout == TIM_R)
                stat = wait_for_rewind(timeout);
        else
                stat = wait_for_ready(timeout);
 
        if (stat==TE_EX) {
                if (tp_sense((cmd==QCMD_SEEK_EOD ?              /*****************************/
                      TP_EOR|TP_NDT|TP_UDA|TP_BNL|TP_WRP|TP_BOM|TP_EOM|TP_FIL :
                      TP_WRP|TP_BOM|TP_EOM|TP_FIL))!=TE_OK) {
                        printk(TPQIC02_NAME ": Exception persist in ll_do_qic_cmd[2](%x, %ld)\n", cmd, (long) timeout);
                        if (cmd!=QCMD_RD_FM)
                                status_dead = YES;
                        return -ENXIO;
                        /* if rdstatus fails too, we're in trouble */
                }
        }
        else if (stat!=TE_OK) {
                printk(TPQIC02_NAME ": ll_do_qic_cmd %x: wait failed, stat == 0x%x\n", cmd, stat);
                return -EIO;
        }
        return 0;
} /* ll_do_qic_cmd */
 
 
/*
 * Problem: What to do when the user cancels a read/write operation
 * in-progress?
 *
 * "Deactivating ONLINE during a READ also causes the"
 * "tape to be rewound to BOT." Ditto for WRITEs, except
 * a FM is written first. "The host may alternatively terminate
 * the READ/WRITE command by issuing a RFM/WFM command."
 *
 * For READs:
 * Neither option will leave the tape positioned where it was.
 * Another (better?) solution is to terminate the READ by two
 * subsequent sense() operations, the first to stop the current
 * READ cycle, the second to clear the `Illegal command' exception,
 * because the QIC-02 specs didn't anticipate this. This is
 * delayed until actually needed, so a tar listing can be aborted
 * by the user and continued later.
 * If anybody has a better solution, let me know! [Also, let me
 * know if your drive (mine is a Wangtek5150EQ) does not accept
 * this sequence for canceling the read-cycle.]
 *
 * For WRITEs it's simple: Just do a WRITE_FM, leaving the tape
 * positioned after the FM.
 */
 
static void terminate_read(int cmd)
{
        if (doing_read == YES) {
                doing_read = NO;
                if (cmd != QCMD_RD_FM) {
                        /* if the command is a RFM, there is no need to do this
                         * because a RFM will legally terminate the read-cycle.
                         */
                        tpqputs(TPQD_ALWAYS, "terminating pending read-cycle");
 
                        /* I'm not too sure about this part  -- hhb */
                        if (QIC02_TAPE_IFC == MOUNTAIN) {
                                /* Mountain reference says can terminate by de-asserting online */
                                ctlbits &= ~MTN_QIC02_CTL_ONLINE;
                        }
 
                        if (tp_sense(TP_FIL|TP_EOM|TP_WRP) != TE_OK) {
                                tpqputs(TPQD_ALWAYS, "finish_rw[read1]: ignore the 2 lines above");
                                if (is_exception()) {
                                        if (tp_sense(TP_ILL|TP_FIL|TP_EOM|TP_WRP) != TE_OK)
                                                tpqputs(TPQD_ALWAYS, "finish_rw[read2]: read cycle error");
                                }
                        }
                }
        }
} /* terminate_read */
 
 
static void terminate_write(int cmd)
{
        int stat;
 
        if (doing_write == YES) {
                doing_write = NO;
                /* Finish writing by appending a FileMark at the end. */
                if (cmd != QCMD_WRT_FM) {
                        /* finish off write cycle */
                        stat = ll_do_qic_cmd(QCMD_WRT_FM, TIM_M);
                        if (stat != TE_OK)
                                tpqputs(TPQD_ALWAYS, "Couldn't finish write cycle properly");
                        (void) tp_sense(0);
                }
                /* If there is an EOF token waiting to be returned to
                 * the (writing) application, discard it now.
                 * We could be at EOT, so don't reset return_write_eof.
                 */
                reported_write_eof=YES;
        }
} /* terminate_write */
 
 
/* terminate read or write cycle because of command `cmd' */
static void finish_rw(int cmd)
{
        if (wait_for_ready(TIM_S) != TE_OK) {
                tpqputs(TPQD_ALWAYS, "error: drive not ready in finish_rw() !");
                return;
        }
        terminate_read(cmd);
        terminate_write(cmd);
} /* finish_rw */
 
 
/* Perform a QIC command through ll_do_qic_cmd().
 * If necessary, rewind the tape first.
 * Return an OS error code if something goes wrong, 0 if all is well.
 */
static int do_qic_cmd(int cmd, time_t timeout)
{
        int stat;
 
 
        finish_rw(cmd);
 
        if (need_rewind) {
                tpqputs(TPQD_REWIND, "Rewinding tape...");
                stat = ll_do_qic_cmd(QCMD_REWIND, TIM_R);
                if (stat != 0) {
                        printk(TPQIC02_NAME ": rewind failed in do_qic_cmd(). stat=0x%2x", stat);
                        return stat;
                }
                need_rewind = NO;
                if (cmd==QCMD_REWIND)   /* don't wind beyond BOT ;-) */
                        return 0;
        }
 
        return ll_do_qic_cmd(cmd, timeout);
} /* do_qic_cmd */
 
 
/* Not all ioctls are supported for all drives. Some rely on
 * optional QIC-02 commands. Check tpqic02.h for configuration.
 * Some of these commands may require ONLINE to be active.
 */
static int do_ioctl_cmd(int cmd)
{
        int stat;
 
        /* It is not permitted to read or wind the tape after bytes have
         * been written. It is not permitted to write the tape while in
         * read mode.
         * We try to be kind and allow reading again after writing a FM...
         */
 
        switch (cmd) {
                case MTRESET:
                        /* reset verbose */
                        return (tape_reset(1)==TE_OK)? 0 : -EIO;
 
                case MTFSF:
                        tpqputs(TPQD_IOCTLS, "MTFSF forward searching filemark");
                        if ((mode_access==WRITE) && status_bytes_wr)
                                return -EACCES;
                        return do_qic_cmd(QCMD_RD_FM, TIM_F);
 
                case MTBSF:
                        if (TP_HAVE_BSF) {
                                tpqputs(TPQD_IOCTLS, "MTBSF backward searching filemark -- optional command");
                                if ((mode_access==WRITE) && status_bytes_wr)
                                        return -EACCES;
                                stat = do_qic_cmd(QCMD_RD_FM_BCK, TIM_F);
                        } else {
                                stat = -ENXIO;
                        }
                        status_eom_detected = status_eof_detected = NO;
                        return stat;
 
                case MTFSR:
                        if (TP_HAVE_FSR) { /* This is an optional QIC-02 command */
                                tpqputs(TPQD_IOCTLS, "MTFSR forward space record");
                                if ((mode_access==WRITE) && status_bytes_wr)
                                        return -EACCES;
                                stat = do_qic_cmd(QCMD_SPACE_FWD, TIM_F);
                        } else {
                                /**** fake it by doing a read data block command? ******/
                                tpqputs(TPQD_IOCTLS, "MTFSR not supported");
                                stat = -ENXIO;
                        }
                        return stat;
 
                case MTBSR:
                        if (TP_HAVE_BSR) { /* This is an optional QIC-02 command */
                                /* we need this for appending files with GNU tar!! */
                                tpqputs(TPQD_IOCTLS, "MTFSR backward space record");
                                if ((mode_access==WRITE) && status_bytes_wr)
                                        return -EACCES;
                                stat = do_qic_cmd(QCMD_SPACE_BCK, TIM_F);
                        } else {
                                tpqputs(TPQD_IOCTLS, "MTBSR not supported");
                                stat = -ENXIO;
                        }
                        status_eom_detected = status_eof_detected = NO;
                        return stat;
 
                case MTWEOF:
                        tpqputs(TPQD_IOCTLS, "MTWEOF write eof mark");
                        /* Plain GNU mt(1) 2.2 uses read-only mode for writing FM. :-( */
                        if (mode_access==READ)
                                return -EACCES;
 
                        /* allow tape movement after writing FM */
                        status_bytes_rd = status_bytes_wr;      /* Kludge-O-Matic */
                        status_bytes_wr = NO;
                        return do_qic_cmd(QCMD_WRT_FM, TIM_M);
                        /* not sure what to do with status_bytes when WFM should fail */
 
                case MTREW:
                        tpqputs(TPQD_IOCTLS, "MTREW rewinding tape");
                        if ((mode_access==WRITE) && status_bytes_wr)
                                return -EACCES;
                        status_eom_detected = status_eof_detected = NO;
                        return do_qic_cmd(QCMD_REWIND, TIM_R);
 
                case MTOFFL:
                        tpqputs(TPQD_IOCTLS, "MTOFFL rewinding & going offline");
                        /* Doing a drive select will clear (unlock) the current drive.
                         * But that requires support for multiple drives and locking.
                         */
                        if ((mode_access==WRITE) && status_bytes_wr)
                                return -EACCES;
                        status_eom_detected = status_eof_detected = NO;
                        /**** do rewind depending on minor bits??? ***/
                        stat = do_qic_cmd(QCMD_REWIND, TIM_R);
                        return stat;
 
                case MTNOP:
                        tpqputs(TPQD_IOCTLS, "MTNOP setting status only");
                        /********** should do `read position' for drives that support it **********/
                        return (tp_sense(-1)==TE_OK)? 0 : -EIO;  /**** check return codes ****/
 
                case MTRETEN:
                        tpqputs(TPQD_IOCTLS, "MTRETEN retension tape");
                        if ((mode_access==WRITE) && status_bytes_wr)
                                return -EACCES;
                        status_eom_detected = status_eof_detected = NO;
                        return do_qic_cmd(QCMD_RETEN, TIM_R);
 
                case MTBSFM:
                        /* Think think is like MTBSF, except that
                         * we shouldn't skip the FM. Tricky.
                         * Maybe use RD_FM_BCK, then do a SPACE_FWD?
                         */
                        tpqputs(TPQD_IOCTLS, "MTBSFM not supported");
                        if ((mode_access==WRITE) && status_bytes_wr)
                                return -EACCES;
                        return -ENXIO;
 
                case MTFSFM:
                        /* I think this is like MTFSF, except that
                         * we shouldn't skip the FM. Tricky.
                         * Maybe use QCMD_RD_DATA until we get a TP_FIL exception?
                         * But then the FM will have been skipped...
                         * Maybe use RD_FM, then RD_FM_BCK, but not all
                         * drives will support that!
                         */
                        tpqputs(TPQD_IOCTLS, "MTFSFM not supported");
                        if ((mode_access==WRITE) && status_bytes_wr)
                                return -EACCES;
                        return -ENXIO;
 
                case MTEOM:
                        /* This should leave the tape ready for appending
                         * another file to the end, such that it would append
                         * after the last FM on tape.
                         */
                        tpqputs(TPQD_IOCTLS, "MTEOM search for End Of recorded Media");
                        if ((mode_access==WRITE) && status_bytes_wr)
                                return -EACCES;
                        if (TP_HAVE_EOD) {
                                /* Use faster seeking when possible.
                                 * This requires the absence of data beyond the EOM.
                                 * It seems that my drive does not always perform the
                                 * SEEK_EOD correctly, unless it is preceded by a
                                 * rewind command.
                                 */
# if 0
                                status_eom_detected = status_eof_detected = NO;
# endif
                                stat = do_qic_cmd(QCMD_REWIND, TIM_R);
                                if (stat)
                                        return stat;
                                stat = do_qic_cmd(QCMD_SEEK_EOD, TIM_F);
                                /* After a successful seek, TP_EOR should be returned */
                        } else {
                                /* else just seek until the drive returns exception "No Data" */
                                stat = 0;
                                while ((stat==0) && (!status_eom_detected)) {
                                        stat = do_qic_cmd(QCMD_RD_FM, TIM_F); /***** should use MTFSFM here???? ******/
                                }
                                if (tperror.exs & TP_NDT)
                                        return 0;
                        }
                        return stat;
 
                case MTERASE:
                        tpqputs(TPQD_IOCTLS, "MTERASE -- ERASE TAPE !");
                        if  ((tperror.exs & TP_ST0) && (tperror.exs & TP_WRP)) {
                                tpqputs(TPQD_ALWAYS, "Cartridge is write-protected.");
                                return -EACCES;
                        } else {
                                time_t t = jiffies;
 
                                /* Plain GNU mt(1) 2.2 erases a tape in O_RDONLY. :-( */
                                if (mode_access==READ)
                                        return -EACCES;
 
                                /* give user a few seconds to pull out tape */
                                while (jiffies - t < 4*HZ)
                                        schedule();
                        }
 
                        /* don't bother writing filemark first */
                        status_eom_detected = status_eof_detected = NO;
                        return do_qic_cmd(QCMD_ERASE, TIM_R);
 
                case MTRAS1:
                        if (TP_HAVE_RAS1) {
                                tpqputs(TPQD_IOCTLS, "MTRAS1: non-destructive self test");
                                stat = do_qic_cmd(QCMD_SELF_TST1, TIM_R);
                                if (stat != 0) {
                                        tpqputs(TPQD_ALWAYS, "RAS1 failed");
                                        return stat;
                                }
                                return (tp_sense(0)==TE_OK)? 0 : -EIO; /* get_ext_status3(); */
                        }
                        tpqputs(TPQD_IOCTLS, "RAS1 not supported");
                        return -ENXIO;
 
                case MTRAS2:
                        if (TP_HAVE_RAS2) {
                                tpqputs(TPQD_IOCTLS, "MTRAS2: destructive self test");
                                stat = do_qic_cmd(QCMD_SELF_TST2, TIM_R);
                                if (stat != 0) {
                                        tpqputs(TPQD_ALWAYS, "RAS2 failed");
                                        return stat;
                                }
                                return (tp_sense(0)==TE_OK)? 0 : -EIO; /* get_ext_status3(); */
                        }
                        tpqputs(TPQD_IOCTLS, "RAS2 not supported");
                        return -ENXIO;
 
                case MTSEEK:
                        if (TP_HAVE_SEEK && (QIC02_TAPE_IFC==ARCHIVE)) {
                                tpqputs(TPQD_IOCTLS, "MTSEEK seeking block");
                                if ((mode_access==WRITE) && status_bytes_wr)
                                        return -EACCES;
                                /* NOTE: address (24 bits) is in seek_addr_buf[] */
                                return do_qic_cmd(AR_QCMDV_SEEK_BLK, TIM_F);
                        }
                        else
                                return -ENOTTY;
 
                default:
                        return -ENOTTY;
        }
} /* do_ioctl_cmd */
 
 
/* dma_transfer(): This routine is called for every 512 bytes to be read
 * from/written to the tape controller. Speed is important here!
 * (There must be enough time left for the hd controller!)
 * When other devices use DMA they must ensure they use un-interruptible
 * double byte accesses to the DMA controller. Floppy.c is ok.
 * Must have interrupts disabled when this function is invoked,
 * otherwise, the double-byte transfers to the DMA controller will not
 * be atomic. That could lead to nasty problems when they are interrupted
 * by other DMA interrupt-routines.
 *
 * This routine merely does the least possible to keep
 * the transfers going:
 *      - set the DMA count register for the next 512 bytes
 *      - adjust the DMA address and page registers
 *      - adjust the timeout
 *      - tell the tape controller to start transferring
 * We assume the dma address and mode are, and remain, valid.
 */
static inline void dma_transfer(void)
{
 
        if (QIC02_TAPE_IFC == WANGTEK) /* or EVEREX */
                outb_p(WT_CTL_ONLINE, QIC02_CTL_PORT);  /* back to normal */
        else if (QIC02_TAPE_IFC == ARCHIVE)
                outb_p(0, AR_RESET_DMA_PORT);
        else /* QIC02_TAPE_IFC == MOUNTAIN */
                outb_p(ctlbits, QIC02_CTL_PORT);
 
 
        clear_dma_ff(QIC02_TAPE_DMA);
        set_dma_mode(QIC02_TAPE_DMA, dma_mode);
        set_dma_addr(QIC02_TAPE_DMA, buffaddr+dma_bytes_done);  /* full address */
        set_dma_count(QIC02_TAPE_DMA, TAPE_BLKSIZE);
 
        /* start tape DMA controller */
        if (QIC02_TAPE_IFC == WANGTEK) /* or EVEREX */
                outb_p(WT_CTL_DMA | WT_CTL_ONLINE, QIC02_CTL_PORT); /* trigger DMA transfer */
 
        else if (QIC02_TAPE_IFC == ARCHIVE) {
                outb_p(AR_CTL_IEN | AR_CTL_DNIEN, QIC02_CTL_PORT);  /* enable interrupts again */
                outb_p(0, AR_START_DMA_PORT);                      /* start DMA transfer */
                /* In dma_end() AR_RESET_DMA_PORT is written too. */
 
        } else /* QIC02_TAPE_IFC == MOUNTAIN */ {
                inb(MTN_R_DESELECT_DMA_PORT);
                outb_p(ctlbits | (MTN_CTL_EXC_IEN | MTN_CTL_DNIEN), QIC02_CTL_PORT);
                outb_p(0, MTN_W_SELECT_DMA_PORT);         /* start DMA transfer */
                if (dma_mode == DMA_MODE_WRITE)
                        outb_p(0, MTN_W_DMA_WRITE_PORT); /* start DMA transfer */
        }
 
        /* start computer DMA controller */
        enable_dma(QIC02_TAPE_DMA);
        /* block transfer should start now, jumping to the
         * interrupt routine when done or an exception was detected.
         */
} /* dma_transfer */
 
 
/* start_dma() sets a DMA transfer up between the tape controller and
 * the kernel qic02_tape_buf buffer.
 * Normally bytes_todo==dma_bytes_done at the end of a DMA transfer. If not,
 * a filemark was read, or an attempt to write beyond the End Of Tape
 * was made. [Or some other bad thing happened.]
 * Must do a sense() before returning error.
 */
static int start_dma(short mode, unsigned long bytes_todo)
/* assume 'bytes_todo'>0 */
{
        int stat;
 
        tpqputs(TPQD_DEBUG, "start_dma() enter");
        TPQDEB({printk(TPQIC02_NAME ": doing_read==%d, doing_write==%d\n", doing_read, doing_write);})
 
        dma_bytes_done = 0;
        dma_bytes_todo = bytes_todo;
        status_error = NO;
        /* dma_mode!=0 indicates that the dma controller is in use */
        dma_mode = (mode == WRITE)? DMA_MODE_WRITE : DMA_MODE_READ;
 
        /* Only give READ/WRITE DATA command to tape drive if we haven't
         * done that already. Otherwise the drive will rewind to the beginning
         * of the current file on tape. Any QIC command given other than
         * R/W FM will break the read/write transfer cycle.
         * do_qic_cmd() will terminate doing_{read,write}
         */
        if ((doing_read == NO) && (doing_write == NO)) {
                /* First, we have to clear the status -- maybe remove TP_FIL???
                 */
 
#if 0
                /* Next dummy get status is to make sure CNI is valid,
                   since we're only just starting a read/write it doesn't
                   matter some exceptions are cleared by reading the status;
                   we're only interested in CNI and WRP. -Eddy */
                get_status(&tperror);
#else
                /* TP_CNI should now be handled in open(). -Hennus */
#endif
 
                stat = tp_sense(((mode == WRITE)? 0 : TP_WRP) | TP_BOM | TP_FIL);
                if (stat != TE_OK)
                        return stat;
 
#if OBSOLETE
                /************* not needed iff rd_status() would wait for ready!!!!!! **********/
                if (wait_for_ready(TIM_S) != TE_OK) {   /*** not sure this is needed ***/
                        tpqputs(TPQD_ALWAYS, "wait_for_ready failed in start_dma");
                        return -EIO;
                }
#endif
 
                if (QIC02_TAPE_IFC == MOUNTAIN) {
                        /* Set control bits to select ONLINE during command */
                        ctlbits |= MTN_QIC02_CTL_ONLINE;
                }
 
                /* Tell the controller the data direction */
 
                /* r/w, timeout medium, check exceptions, sets status_cmd_pending. */
                stat = send_qic02_cmd((mode == WRITE)? QCMD_WRT_DATA : QCMD_RD_DATA, TIM_M, 0);
                if (stat!=TE_OK) {
                        printk(TPQIC02_NAME ": start_dma: init %s failed\n",
                                (mode == WRITE)? "write" : "read");
                        (void) tp_sense(0);
                        return stat;
                }
 
                /* Do this last, because sense() will clear the doing_{read,write}
                 * flags, causing trouble next time around.
                 */
                if (wait_for_ready(TIM_M) != TE_OK)
                        return -EIO;
                switch (mode) {
                        case READ:
                                doing_read = YES;
                                break;
                        case WRITE:
                                doing_write = YES;
                                break;
                        default:
                                printk(TPQIC02_NAME ": requested unknown mode %d\n", mode);
                                panic(TPQIC02_NAME ": invalid mode in start_dma()");
                }
 
        } else if (is_exception()) {
                /* This is for Archive drives, to handle reads with 0 bytes
                 * left for the last read request.
                 *
                 * ******** this also affects EOF/EOT handling! ************
                 */
                tpqputs(TPQD_ALWAYS, "detected exception in start_dma() while transfer in progress");
                status_error = YES;
                return TE_END;
        }
 
 
        status_expect_int = YES;
 
        /* This assumes tape is already positioned, but these
         * semi-'intelligent' drives are unpredictable...
         */
        TIMERON(TIM_M*2);
 
        /* initiate first data block read from/write to the tape controller */
 
        cli();
        dma_transfer();
        sti();
 
        TPQPUTS("start_dma() end");
        return TE_OK;
} /* start_dma */
 
 
/* This cleans up after the dma transfer has completed
 * (or failed). If an exception occurred, a sense()
 * must be done. If the exception was caused by a FM,
 * sense() will set `status_eof_detected' and
 * `status_eom_detected', as required.
 */
static void end_dma(unsigned long * bytes_done)
{
        int stat = TE_OK;
 
        TIMEROFF;
 
        TPQPUTS("end_dma() enter");
 
        disable_dma(QIC02_TAPE_DMA);
        clear_dma_ff(QIC02_TAPE_DMA);
 
        if (QIC02_TAPE_IFC == WANGTEK) /* or EVEREX */
                outb_p(WT_CTL_ONLINE, QIC02_CTL_PORT);  /* back to normal */
        else if (QIC02_TAPE_IFC == ARCHIVE)
                outb_p(0, AR_RESET_DMA_PORT);
        else /* QIC02_TAPE_IFC == MOUNTAIN */ {
                /* Clear control bits, de-select ONLINE during tp_sense */
                ctlbits &= ~MTN_QIC02_CTL_ONLINE;
        }
 
        stat = wait_for_ready(TIM_M);
        if (status_error || (stat!=TE_OK)) {
                tpqputs(TPQD_DMAX, "DMA transfer exception");
                stat = tp_sense((dma_mode==READ)? TP_WRP : 0);
                /* no return here -- got to clean up first! */
        } else /* if (QIC02_TAPE_IFC == MOUNTAIN) */ {
                outb_p(ctlbits, QIC02_CTL_PORT);
        }
 
        if (QIC02_TAPE_IFC == MOUNTAIN)
                inb(MTN_R_DESELECT_DMA_PORT);
 
        /* take the tape controller offline */
 
        /* finish off DMA stuff */
 
 
        dma_mode = 0;
        /* Note: The drive is left on-line, ready for the next
         * data transfer.
         * If the next command to the drive does not continue
         * the pending cycle, it must do 2 sense()s first.
         */
 
        *bytes_done = dma_bytes_done;
        status_expect_int = NO;
        ioctl_status.mt_blkno += (dma_bytes_done / TAPE_BLKSIZE);
 
        TPQPUTS("end_dma() exit");
        /*** could return stat here ***/
} /* end_dma */
 
/*********** Below are the (public) OS-interface procedures ***********/
 
 
/* qic02_tape_times_out() is called when a DMA transfer doesn't complete
 * quickly enough. Usually this means there is something seriously wrong
 * with the hardware/software, but it could just be that the controller
 * has decided to do a long rewind, just when I didn't expect it.
 * Just try again.
 */
static void qic02_tape_times_out(void)
{
        printk("time-out in %s driver\n", TPQIC02_NAME);
        if ((status_cmd_pending>0) || dma_mode) {
                /* takes tooo long, shut it down */
                status_dead = YES;
                status_cmd_pending = 0;
                status_timer_on = NO;
                status_expect_int = NO;
                status_error = YES;
                if (dma_mode) {
                        dma_mode = 0;    /* signal end to read/write routine */
                        wake_up(&qic02_tape_transfer);
                }
        }
} /* qic02_tape_times_out */
 
/*
 * Interrupt handling:
 *
 * 1) Interrupt is generated iff at the end of
 *    a 512-DMA-block transfer.
 * 2) EXCEPTION is not raised unless something
 *    is wrong or EOT/FM is detected.
 * 3) FM EXCEPTION is set *after* the last byte has
 *    been transferred by DMA. By the time the interrupt
 *    is handled, the EXCEPTION may already be set.
 *
 * So,
 * 1) On EXCEPTION, assume data has been transferred, so
 *    continue as usual, but set a flag to indicate the
 *    exception was detected.
 *    Do a sense status when the flag is found set.
 * 2) Do not attempt to continue a transfer after an exception.
 *    [??? What about marginal blocks???????]
 */
 
 
/* qic02_tape_interrupt() is called when the tape controller completes
 * a DMA transfer.
 * We are not allowed to sleep here!
 *
 * Check if the transfer was successful, check if we need to transfer
 * more. If the buffer contains enough data/is empty enough, signal the
 * read/write() thread to copy to/from user space.
 * When we are finished, set flags to indicate end, disable timer.
 * NOTE: This *must* be fast!
 */
static void qic02_tape_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
        int stat, r, i;
 
        TIMEROFF;
 
        if (status_expect_int) {
#ifdef WANT_EXTRA_FULL_DEBUGGING
                if (TP_DIAGS(current_tape_dev))
                        printk("@");
#endif
                stat = inb(QIC02_STAT_PORT);    /* Knock, knock */
                if (QIC02_TAPE_IFC == ARCHIVE) {        /* "Who's there?" */
                        if (((stat & (AR_STAT_DMADONE)) == 0) &&
                              ((stat & (QIC02_STAT_EXCEPTION)) != 0)) {
                                TIMERCONT;
                                return;                 /* "Linux with IRQ sharing" */
                        }
                }
 
                if ((stat & QIC02_STAT_EXCEPTION) == 0) {        /* exception occurred */
                        /* Possible causes for an exception during a transfer:
                         *      - during a write-cycle: end of tape (EW) hole detected.
                         *      - during a read-cycle: filemark or EOD detected.
                         *      - something went wrong
                         * So don't continue with the next block.
                         */
                        tpqputs(TPQD_ALWAYS, "isr: exception on tape controller");
                        printk("      status %02x\n", stat);
                        status_error = TE_EX;
 
                        dma_bytes_done += TAPE_BLKSIZE;
 
                        dma_mode = 0;    /* wake up rw() */
                        status_expect_int = NO;
                        wake_up(&qic02_tape_transfer);
                        return;
                }
                /* return if tape controller not ready, or
                 * if dma channel hasn't finished last byte yet.
                 */
                r = 0;
/* Skip next ready check for Archive controller because
 * it may be busy reading ahead. Weird. --hhb
 */
                if (QIC02_TAPE_IFC == WANGTEK)  /* I think this is a drive-dependency, not IFC -- hhb */
                        if (stat & QIC02_STAT_READY) {          /* not ready */
                                tpqputs(TPQD_ALWAYS, "isr: ? Tape controller not ready");
                                r = 1;
                        }
 
                if ( (i = get_dma_residue(QIC02_TAPE_DMA)) != 0 ) {
                        printk(TPQIC02_NAME ": dma_residue == %x !!!\n", i);
                        r = 1;  /* big trouble, but can't do much about it... */
                }
 
                if (r)
                        return;
 
                /* finish DMA cycle */
 
                /* no errors detected, continue */
                dma_bytes_done += TAPE_BLKSIZE;
                if (dma_bytes_done >= dma_bytes_todo) {
                        /* finished! Wakeup rw() */
                        dma_mode = 0;
                        status_expect_int = NO;
                        TPQPUTS("isr: dma_bytes_done");
                        wake_up(&qic02_tape_transfer);
                } else {
                        /* start next transfer, account for track-switching time */
                        timer_table[QIC02_TAPE_TIMER].expires = jiffies + 6*HZ;
                        dma_transfer();
                }
        } else {
                printk(TPQIC02_NAME ": Unexpected interrupt, stat == %x\n",
                       inb(QIC02_STAT_PORT));
        }
} /* qic02_tape_interrupt */
 
 
static int qic02_tape_lseek(struct inode * inode, struct file * file, off_t offset, int origin)
{
        return -EINVAL; /* not supported */
} /* qic02_tape_lseek */
 
 
/* read/write routines:
 * This code copies between a kernel buffer and a user buffer. The
 * actual data transfer is done using DMA and interrupts. Time-outs
 * are also used.
 *
 * When a filemark is read, we return '0 bytes read' and continue with the
 * next file after that.
 * When EOM is read, we return '0 bytes read' twice.
 * When the EOT marker is detected on writes, '0 bytes read' should be
 * returned twice. If user program does a MTNOP after that, 2 additional
 * blocks may be written.       ------- FIXME: Implement this correctly  *************************************************
 *
 * Only read/writes in multiples of 512 bytes are accepted.
 * When no bytes are available, we sleep() until they are. The controller will
 * generate an interrupt, and we (should) get a wake_up() call.
 *
 * Simple buffering is used. User program should ensure that a large enough
 * buffer is used. Usually the drive does some buffering as well (something
 * like 4k or so).
 *
 * Scott S. Bertilson suggested to continue filling the user buffer, rather
 * than waste time on a context switch, when the kernel buffer fills up.
 */
 
/*
 * Problem: tar(1) doesn't always read the entire file. Sometimes the entire file
 * has been read, but the EOF token is never returned to tar(1), simply because
 * tar(1) knows it has already read all of the data it needs. So we must use
 * open/release to reset the `reported_read_eof' flag. If we don't, the next read
 * request would return the EOF flag for the previous file.
 */
 
static int qic02_tape_read(struct inode * inode, struct file * filp, char * buf, int count)
{
        int error;
        kdev_t dev = inode->i_rdev;
        unsigned short flags = filp->f_flags;
        unsigned long bytes_todo, bytes_done, total_bytes_done = 0;
        int stat;
 
        if (status_zombie==YES) {
                tpqputs(TPQD_ALWAYS, "configs not set");
                return -ENXIO;
        }
 
        if (TP_DIAGS(current_tape_dev))
                /* can't print a ``long long'' (for filp->f_pos), so chop it */
                printk(TPQIC02_NAME ": request READ, minor=%x, buf=%p, count=%x, pos=%lx, flags=%x\n",
                        MINOR(dev), buf, count, (unsigned long) filp->f_pos, flags);
 
        if (count % TAPE_BLKSIZE) {     /* Only allow mod 512 bytes at a time. */
                tpqputs(TPQD_BLKSZ, "Wrong block size");
                return -EINVAL;
        }
 
        /* Just assume everything is ok. Controller will scream if not. */
 
        if (status_bytes_wr)    /* Once written, no more reads, 'till after WFM. */
                return -EACCES;
 
 
        /* Make sure buffer is safe to write into. */
        error = verify_area(VERIFY_WRITE, buf, count);
        if (error)
                return error;
 
        /* This is rather ugly because it has to implement a finite state
         * machine in order to handle the EOF situations properly.
         */
        while (count>=0) {
                bytes_done = 0;
                /* see how much fits in the kernel buffer */
                bytes_todo = TPQBUF_SIZE;
                if (bytes_todo>count)
                        bytes_todo = count;
 
                /* Must ensure that user program sees exactly one EOF token (==0) */
                if (return_read_eof==YES) {
                        if (TPQDBG(DEBUG))
                                printk("read: return_read_eof==%d, reported_read_eof==%d, total_bytes_done==%lu\n", return_read_eof, reported_read_eof, total_bytes_done);
 
                        if (reported_read_eof==NO) {
                                /* have not yet returned EOF to user program */
                                if (total_bytes_done>0) {
                                        return total_bytes_done; /* next time return EOF */
                                } else {
                                        reported_read_eof = YES; /* move on next time */
                                        return 0;                 /* return EOF */
                                }
                        } else {
                                /* Application program has already received EOF
                                 * (above), now continue with next file on tape,
                                 * if possible.
                                 * When the FM is reached, EXCEPTION is set,
                                 * causing a sense(). Subsequent read/writes will
                                 * continue after the FM.
                                 */
/*********** ?????????? this should check for (EOD|NDT), not EOM, 'cause we can read past EW: ************/
                                if (status_eom_detected)
                                        /* If EOM, nothing left to read, so keep returning EOFs.
                                         *** should probably set some flag to avoid clearing
                                         *** status_eom_detected through ioctls or something
                                         */
                                        return 0;
                                else {
                                        /* just eof, there may be more files ahead... */
                                        return_read_eof = NO;
                                        reported_read_eof = NO;
                                        status_eof_detected = NO; /* reset this too */
                                        /*fall through*/
                                }
                        }
                }
 
/*****************************/
                if (bytes_todo==0)
                        return total_bytes_done;
 
                if (bytes_todo>0) {
                        /* start reading data */
                        if (is_exception())     /****************************************/
                                tpqputs(TPQD_DMAX, "is_exception() before start_dma()!");
/******************************************************************
 ***** if start_dma() fails because the head is positioned 0 bytes
 ***** before the FM, (causing EXCEPTION to be set) return_read_eof should
 ***** be set to YES, and we should return total_bytes_done, rather than -ENXIO.
 ***** The app should recognize this as an EOF condition.
 ***************************************************************************/
                        stat = start_dma(READ, bytes_todo);
                        if (stat == TE_OK) {
                                /* Wait for transfer to complete, interrupt should wake us */
                                while (dma_mode != 0) {
                                        sleep_on(&qic02_tape_transfer);
                                }
                                if (status_error)
                                        return_read_eof = YES;
                        } else if (stat != TE_END) {
                                /* should do sense() on error here */
#if 0
                                return -ENXIO;
#else
                                printk("Trouble: stat==%02x\n", stat);
                                return_read_eof = YES;
                                /*************** check EOF/EOT handling!!!!!! **/
#endif
                        }
                        end_dma(&bytes_done);
                        if (bytes_done>bytes_todo) {
                                tpqputs(TPQD_ALWAYS, "read: Oops, read more bytes than requested");
                                return -EIO;
                        }
                        /* copy buffer to user-space in one go */
                        if (bytes_done>0)
                                memcpy_tofs( (void *) buf, (void *) buffaddr, bytes_done);
#if 1
                        /* Checks Ton's patch below */
                        if ((return_read_eof == NO) && (status_eof_detected == YES)) {
                                printk(TPQIC02_NAME ": read(): return_read_eof=%d, status_eof_detected=YES. return_read_eof:=YES\n", return_read_eof);
                        }
#endif
                        if ((bytes_todo != bytes_done) || (status_eof_detected == YES))
                                /* EOF or EOM detected. return EOF next time. */
                                return_read_eof = YES;
                } /* else: ignore read request for 0 bytes */
 
                if (bytes_done>0) {
                        status_bytes_rd = YES;
                        buf += bytes_done;
                        filp->f_pos += bytes_done;
                        total_bytes_done += bytes_done;
                        count -= bytes_done;
                }
        }
        tpqputs(TPQD_ALWAYS, "read request for <0 bytes");
        return -EINVAL;
} /* qic02_tape_read */
 
 
 
/* The drive detects near-EOT by means of the holes in the tape.
 * When the holes are detected, there is some space left. The drive
 * reports this as a TP_EOM exception. After clearing the exception,
 * the drive should accept two extra blocks.
 *
 * It seems there are some archiver programs that would like to use the
 * extra space for writing a continuation marker. The driver should return
 * end-of-file to the user program on writes, when the holes are detected.
 * If the user-program wants to use the extra space, it should use the
 * MTNOP ioctl() to get the generic status register and may then continue
 * writing (max 1kB).   ----------- doesn't work yet...............
 *
 * EOF behaviour on writes:
 * If there is enough room, write all of the data.
 * If there is insufficient room, write as much as will fit and
 * return the amount written. If the requested amount differs from the
 * written amount, the application program should recognize that as the
 * end of file. Subsequent writes will return -ENOSPC.
 * Unless the minor bits specify a rewind-on-close, the tape will not
 * be rewound when it is full. The user-program should do that, if desired.
 * If the driver were to do that automatically, a user-program could be
 * confused about the EOT/BOT condition after re-opening the tape device.
 *
 * Multiple volume support: Tar closes the tape device before prompting for
 * the next tape. The user may then insert a new tape and tar will open the
 * tape device again. The driver will detect an exception status in (No Cartridge)
 * and force a rewind. After that tar may continue writing.
 */
static int qic02_tape_write(struct inode * inode, struct file * filp, const char * buf, int count)
{
        int error;
        kdev_t dev = inode->i_rdev;
        unsigned short flags = filp->f_flags;
        unsigned long bytes_todo, bytes_done, total_bytes_done = 0;
 
        if (status_zombie==YES) {
                tpqputs(TPQD_ALWAYS, "configs not set");
                return -ENXIO;
        }
 
        if (TP_DIAGS(current_tape_dev))
                /* can't print a ``long long'' (for filp->f_pos), so chop it */
                printk(TPQIC02_NAME ": request WRITE, minor=%x, buf=%p, count=%x, pos=%lx, flags=%x\n",
                        MINOR(dev), buf, count, (unsigned long) filp->f_pos, flags);
 
        if (count % TAPE_BLKSIZE) {     /* only allow mod 512 bytes at a time */
                tpqputs(TPQD_BLKSZ, "Wrong block size");
                return -EINVAL;
        }
 
        if (mode_access==READ) {
                tpqputs(TPQD_ALWAYS, "Not in write mode");
                return -EACCES;
        }
 
        /* open() does a sense() and we can assume the tape isn't changed
         * between open() and release(), so the tperror.exs bits will still
         * be valid.
         */
        if ((tperror.exs & TP_ST0) && (tperror.exs & TP_WRP)) {
                tpqputs(TPQD_ALWAYS, "Cartridge is write-protected.");
                return -EACCES; /* don't even try when write protected */
        }
 
        /* Make sure buffer is safe to read from. */
        error = verify_area(VERIFY_READ, buf, count);
        if (error)
                return error;
 
        if (doing_read == YES)
                terminate_read(0);
 
        while (count>=0) {
                /* see how much fits in the kernel buffer */
                bytes_done = 0;
                bytes_todo = TPQBUF_SIZE;
                if (bytes_todo>count)
                        bytes_todo = count;
 
                if (return_write_eof == YES) {
                        /* return_write_eof should be reset on reverse tape movements. */
 
                        if (reported_write_eof==NO) {
                                if (bytes_todo>0) {
                                        tpqputs(TPQD_ALWAYS, "partial write");
                                        /* partial write signals EOF to user program */
                                }
                                reported_write_eof = YES;
                                return total_bytes_done;
                        } else {
                                return -ENOSPC;          /* return error */
                        }
                }
 
                /* Quit when done. */
                if (bytes_todo==0)
                        return total_bytes_done;
 
 
                /* copy from user to DMA buffer and initiate transfer. */
                if (bytes_todo>0) {
                        memcpy_fromfs( (void *) buffaddr, (const void *) buf, bytes_todo);
 
/****************** similar problem with read() at FM could happen here at EOT.
 ******************/
 
/***** if at EOT, 0 bytes can be written. start_dma() will
 ***** fail and write() will return ENXIO error
 *****/
                        if (start_dma(WRITE, bytes_todo) != TE_OK) {
                                tpqputs(TPQD_ALWAYS, "write: start_dma() failed");
                                /* should do sense() on error here */
                                return -ENXIO;  /*********** FIXTHIS **************/
                        }
 
                        /* Wait for write to complete, interrupt should wake us. */
                        while ((status_error == 0) && (dma_mode != 0)) {
                                sleep_on(&qic02_tape_transfer);
                        }
 
                        end_dma(&bytes_done);
                        if (bytes_done>bytes_todo) {
                                tpqputs(TPQD_ALWAYS, "write: Oops, wrote more bytes than requested");
                                return -EIO;
                        }
                        /* If the dma-transfer was aborted because of an exception,
                         * status_error will have been set in the interrupt handler.
                         * Then end_dma() will do a sense().
                         * If the exception was EXC_EOM, the EW-hole was encountered
                         * and two more blocks could be written. For the time being we'll
                         * just consider this to be the EOT.
                         * Otherwise, something Bad happened, such as the maximum number
                         * of block-rewrites was exceeded. [e.g. A very bad spot on tape was
                         * encountered. Normally short dropouts are compensated for by
                         * rewriting the block in error, up to 16 times. I'm not sure
                         * QIC-24 drives can do this.]
                         */
                        if (status_error) {
                                if (status_eom_detected == YES) {
                                        tpqputs(TPQD_ALWAYS, "write: EW detected");
                                        return_write_eof = YES;
                                } else {
                                        /* probably EXC_RWA */
                                        tpqputs(TPQD_ALWAYS, "write: dma: error in writing");
                                        return -EIO;
                                }
                        }
                        if (bytes_todo != bytes_done)
                                /* EOF or EOM detected. return EOT next time. */
                                return_write_eof = YES;
                }
                /* else: ignore write request for 0 bytes. */
 
                if (bytes_done>0) {
                        status_bytes_wr = YES;
                        buf += bytes_done;
                        filp->f_pos += bytes_done;
                        total_bytes_done += bytes_done;
                        count -= bytes_done;
                }
        }
        tpqputs(TPQD_ALWAYS, "write request for <0 bytes");
        if (TPQDBG(DEBUG))
                printk(TPQIC02_NAME ": status_bytes_wr %x, buf %p, total_bytes_done %lx, count %x\n", status_bytes_wr, buf, total_bytes_done, count);
        return -EINVAL;
} /* qic02_tape_write */
 
 
 
/* qic02_tape_open()
 * We allow the device to be opened, even if it is marked 'dead' because
 * we want to be able to reset the tape device without rebooting.
 * Only one open tape file at a time, except when minor=255.
 * Minor 255 is only allowed for resetting and always returns <0.
 *
 * The density command is only allowed when TP_BOM is set. Thus, remember
 * the most recently used minor bits. When they are different from the
 * remembered values, rewind the tape and set the required density.
 * Don't rewind if the minor bits specify density 0.
 */
static int qic02_tape_open(struct inode * inode, struct file * filp)
{
        kdev_t dev = inode->i_rdev;
        unsigned short flags = filp->f_flags;
        unsigned short dens = 0;
        int s;
 
 
        if (TP_DIAGS(dev)) {
                printk("qic02_tape_open: dev=%s, flags=%x     ",
                       kdevname(dev), flags);
        }
 
        if (MINOR(dev)==255)    /* special case for resetting */
                if (suser())
                        return (tape_reset(1)==TE_OK) ? -EAGAIN : -ENXIO;
                else
                        return -EPERM;
 
        if (status_dead==YES)
                /* Allow `mt reset' ioctl() even when already open()ed. */
                return 0;
 
        /* Only one at a time from here on... */
        if (filp->f_count>1) {  /* filp->f_count==1 for the first open() */
                return -EBUSY;
        }
 
        if (status_zombie==YES)
                /* no irq/dma/port stuff allocated yet, no reset done
                 * yet, so return until MTSETCONFIG has been done.
                 */
                return 0;
 
        status_bytes_rd = NO;
        status_bytes_wr = NO;
 
        return_read_eof = NO;   /********????????????????*****/
        return_write_eof = (status_eot_detected)? YES : NO;
 
        /* Clear this in case user app close()d before reading EOF token */
        status_eof_detected = NO;
 
        reported_read_eof = NO;
        reported_write_eof = NO;
 
 
        switch (flags & O_ACCMODE) {
                case O_RDONLY:
                        mode_access = READ;
                        break;
                case O_WRONLY:  /* Fallthru... Strictly speaking this is not correct... */
                case O_RDWR:    /* Reads are allowed as long as nothing is written */
                        mode_access = WRITE;
                        break;
        }
 
        /* This is to avoid tape-changed problems (TP_CNI exception).
         *
         * Since removing the cartridge will not raise an exception,
         * we always do a tp_sense() to make sure we have the proper
         * CNI status, the 2150L may need an additional sense.... - Eddy
         */
        s = tp_sense(TP_WRP|TP_EOM|TP_BOM|TP_CNI|TP_EOR);
 
        if (s == TE_OK)
                /* Try to clear cartridge-changed status for Archive-2150L */
                if ((tperror.exs & TP_ST0) && (tperror.exs & TP_CNI))
                        s = tp_sense(TP_WRP|TP_EOM|TP_BOM|TP_CNI|TP_EOR);
 
        if (s != TE_OK) {
                tpqputs(TPQD_ALWAYS, "open: sense() failed");
                return -EIO;
        }
 
        /* exception bits should be up-to-date now, so check for
         * tape presence and exit if absent.
         * Even `mt stat' will fail without a tape.
         */
        if ((tperror.exs & TP_ST0) && (tperror.exs & TP_CNI)) {
                tpqputs(TPQD_ALWAYS, "No tape present.");
                return -EIO;
        }
 
        /* At this point we can assume that a tape is present and
         * that it will remain present until release() is called.
         */
 
        /* not allowed to do QCMD_DENS_* unless tape is rewound */
        if ((TP_DENS(dev)!=0) && (TP_DENS(current_tape_dev) != TP_DENS(dev))) {
                /* force rewind if minor bits have changed,
                 * i.e. user wants to use tape in different format.
                 * [assuming single drive operation]
                 */
                if (TP_HAVE_DENS) {
                        tpqputs(TPQD_REWIND, "Density minor bits have changed. Forcing rewind.");
                        need_rewind = YES;
                }
        } else {
                /* density bits still the same, but TP_DIAGS bit
                 * may have changed.
                 */
                current_tape_dev = dev;
        }
 
        if (need_rewind == YES) { /***************** CHECK THIS!!!!!!!! **********/
                s = do_qic_cmd(QCMD_REWIND, TIM_R);
                if (s != 0) {
                        tpqputs(TPQD_ALWAYS, "open: rewind failed");
                        return -EIO;
                }
        }
 
 
/* Note: After a reset command, the controller will rewind the tape
 *       just before performing any tape movement operation! ************ SO SET need_rewind flag!!!!!
 */
        if (status_dead==YES) {
                tpqputs(TPQD_ALWAYS, "open: tape dead, attempting reset");
                if (tape_reset(1)!=TE_OK) {
                        return -ENXIO;
                } else {
                        status_dead = NO;
                        if (tp_sense(~(TP_ST1|TP_ILL)) != TE_OK) {
                                tpqputs(TPQD_ALWAYS, "open: tp_sense() failed\n");
                                status_dead = YES;      /* try reset next time */
                                return -EIO;
                        }
                }
        }
 
        /* things should be ok, once we get here */
 
 
        /* set density: only allowed when TP_BOM status bit is set,
         * so we must have done a rewind by now. If not, just skip over.
         * Only give set density command when minor bits have changed.
         */
        if (TP_DENS(current_tape_dev) == TP_DENS(dev) )
                return 0;
 
        current_tape_dev = dev;
        need_rewind = NO;
        if (TP_HAVE_DENS)
                dens = TP_DENS(dev);
 
        if (dens < sizeof(format_names)/sizeof(char *))
                printk(TPQIC02_NAME ": format: %s%s\n", (dens!=0)? "QIC-" : "", format_names[dens]);
        else
                tpqputs(TPQD_REWIND, "Wait for retensioning...");
 
        switch (TP_DENS(dev)) {
                case 0: /* Minor 0 is for drives without set-density support */
                        s = 0;
                        break;
                case 1:
                        s = do_qic_cmd(QCMD_DENS_11, TIM_S);
                        break;
                case 2:
                        s = do_qic_cmd(QCMD_DENS_24, TIM_S);
                        break;
                case 3:
                        s = do_qic_cmd(QCMD_DENS_120, TIM_S);
                        break;
                case 4:
                        s = do_qic_cmd(QCMD_DENS_150, TIM_S);
                        break;
                case 5:
                        s = do_qic_cmd(QCMD_DENS_300, TIM_S);
                        break;
                case 6:
                        s = do_qic_cmd(QCMD_DENS_600, TIM_S);
                        break;
                default:  /* otherwise do a retension before anything else */
                        s = do_qic_cmd(QCMD_RETEN, TIM_R);
        }
        if (s != 0) {
                status_dead = YES;      /* force reset */
                current_tape_dev = 0; /* earlier 0xff80 */
                return -EIO;
        }
 
        return 0;
} /* qic02_tape_open */
 
 
static void qic02_tape_release(struct inode * inode, struct file * filp)
{
        kdev_t dev = inode->i_rdev;
 
        if (TP_DIAGS(dev))
                printk("qic02_tape_release: dev=%s\n",
                       kdevname(dev));
 
        if (status_zombie==YES)         /* don't rewind in zombie mode */
                return;
 
        /* Terminate any pending write cycle. Terminating the read-cycle
         * is delayed until it is required to do so for a new command.
         */
        terminate_write(-1);
 
        if (status_dead==YES)
                tpqputs(TPQD_ALWAYS, "release: device dead!?");
 
        /* Rewind only if minor number requires it AND
         * read/writes have been done. ************* IS THIS CORRECT??????????
         */
        if ((TP_REWCLOSE(dev)) && (status_bytes_rd | status_bytes_wr)) {
                tpqputs(TPQD_REWIND, "release: Doing rewind...");
                (void) do_qic_cmd(QCMD_REWIND, TIM_R);
        }
 
        return;
} /* qic02_tape_release */
 
 
#ifdef CONFIG_QIC02_DYNCONF
/* Set masks etc. based on the interface card type. */
int update_ifc_masks(int ifc)
{
        QIC02_TAPE_IFC = ifc;
 
        if ((QIC02_TAPE_IFC == WANGTEK) || (QIC02_TAPE_IFC == EVEREX)) {
                QIC02_STAT_PORT = QIC02_TAPE_PORT;
                QIC02_CTL_PORT = QIC02_TAPE_PORT;
                QIC02_CMD_PORT = QIC02_TAPE_PORT+1;
                QIC02_DATA_PORT = QIC02_TAPE_PORT+1;
                QIC02_STAT_READY = WT_QIC02_STAT_READY;
                QIC02_STAT_EXCEPTION = WT_QIC02_STAT_EXCEPTION;
                QIC02_STAT_MASK = WT_QIC02_STAT_MASK;
 
                QIC02_STAT_RESETMASK = WT_QIC02_STAT_RESETMASK;
                QIC02_STAT_RESETVAL = WT_QIC02_STAT_RESETVAL;
 
                QIC02_CTL_RESET = WT_QIC02_CTL_RESET;
                QIC02_CTL_REQUEST = WT_QIC02_CTL_REQUEST;
 
                if (QIC02_TAPE_DMA == 3)
                        WT_CTL_DMA = WT_CTL_DMA3;
                else if (QIC02_TAPE_DMA == 1)
                        WT_CTL_DMA = WT_CTL_DMA1;
                else {
                        tpqputs(TPQD_ALWAYS, "Unsupported or incorrect DMA channel");
                        return -EIO;
                }
 
                if (QIC02_TAPE_IFC == EVEREX) {
                        /* Everex is a special case for Wangtek (actually
                         * it's the other way 'round, but I saw Wangtek first)
                         */
                        if (QIC02_TAPE_DMA==3)
                                WT_CTL_DMA = WT_CTL_DMA1;
                        /* Fixup the kernel copy of the IFC type to that
                         * we don't have to distinguish between Wangtek and
                         * and Everex at runtime.
                         */
                        QIC02_TAPE_IFC = WANGTEK;
                }
        } else if (QIC02_TAPE_IFC == ARCHIVE) {
                QIC02_STAT_PORT = QIC02_TAPE_PORT+1;
                QIC02_CTL_PORT = QIC02_TAPE_PORT+1;
                QIC02_CMD_PORT = QIC02_TAPE_PORT;
                QIC02_DATA_PORT = QIC02_TAPE_PORT;
                QIC02_STAT_READY = AR_QIC02_STAT_READY;
                QIC02_STAT_EXCEPTION  = AR_QIC02_STAT_EXCEPTION;
                QIC02_STAT_MASK = AR_QIC02_STAT_MASK;
 
                QIC02_STAT_RESETMASK = AR_QIC02_STAT_RESETMASK;
                QIC02_STAT_RESETVAL = AR_QIC02_STAT_RESETVAL;
 
                QIC02_CTL_RESET = AR_QIC02_CTL_RESET;
                QIC02_CTL_REQUEST = AR_QIC02_CTL_REQUEST;
 
                if (QIC02_TAPE_DMA > 3) {
                        tpqputs(TPQD_ALWAYS, "Unsupported or incorrect DMA channel");
                        return -EIO;
                }
        } else if (QIC02_TAPE_IFC == MOUNTAIN) {
                QIC02_STAT_PORT = QIC02_TAPE_PORT+1;
                QIC02_CTL_PORT = QIC02_TAPE_PORT+1;
                QIC02_CMD_PORT = QIC02_TAPE_PORT;
                QIC02_DATA_PORT = QIC02_TAPE_PORT;
 
                QIC02_STAT_READY = MTN_QIC02_STAT_READY;
                QIC02_STAT_EXCEPTION  = MTN_QIC02_STAT_EXCEPTION;
                QIC02_STAT_MASK = MTN_QIC02_STAT_MASK;
 
                QIC02_STAT_RESETMASK = MTN_QIC02_STAT_RESETMASK;
                QIC02_STAT_RESETVAL = MTN_QIC02_STAT_RESETVAL;
 
                QIC02_CTL_RESET = MTN_QIC02_CTL_RESET;
                QIC02_CTL_REQUEST = MTN_QIC02_CTL_REQUEST;
 
                if (QIC02_TAPE_DMA > 3) {
                        tpqputs(TPQD_ALWAYS, "Unsupported or incorrect DMA channel");
                        return -EIO;
                }
        } else {
                tpqputs(TPQD_ALWAYS, "Invalid interface type");
                return -ENXIO;
        }
        return 0;
} /* update_ifc-masks */
#endif
 
 
/* ioctl allows user programs to rewind the tape and stuff like that */
static int qic02_tape_ioctl(struct inode * inode, struct file * filp,
                     unsigned int iocmd, unsigned long ioarg)
{
        int error;
        short i;
        int dev_maj = MAJOR(inode->i_rdev);
        int c;
        struct mtop operation;
        char *stp, *argp;
        unsigned char blk_addr[6];
        struct mtpos ioctl_tell;
 
 
        if (TP_DIAGS(current_tape_dev))
                printk(TPQIC02_NAME ": ioctl(%4x, %4x, %4lx)\n", dev_maj, iocmd, ioarg);
 
        if (!inode || !ioarg)
                return -EINVAL;
 
        /* check iocmd first */
 
        if (dev_maj != QIC02_TAPE_MAJOR) {
                printk(TPQIC02_NAME ": Oops! Wrong device?\n");
                /* A panic() would be appropriate here */
                return -ENODEV;
        }
 
        c = iocmd & IOCCMD_MASK;
 
#ifdef DDIOCSDBG
        /* Check for DDI Debug Control, contributed by FvK, edited by HHB. */
        if (c == DDIOCSDBG) {
                if (!suser())
                        return -EPERM;
                error = verify_area(VERIFY_READ, (int *) ioarg, sizeof(int));
                if (error) return error;
                c = get_user((int *) ioarg);
                if (c==0) {
                        QIC02_TAPE_DEBUG = 0;
                        return 0;
                }
                if ((c>=1) && (c<=32)) {
                        QIC02_TAPE_DEBUG |= (1 << (c-1));
                        return 0;
                }
                if (c >= 128) {
                        QIC02_TAPE_DEBUG &= ~(1 << (c - 128));
                        return 0;
                }
                return -EINVAL;
        }
#endif
 
#ifdef CONFIG_QIC02_DYNCONF
        if (c == (MTIOCGETCONFIG & IOCCMD_MASK)) {
                if (((iocmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT) != sizeof(struct mtconfiginfo)) {
                        tpqputs(TPQD_ALWAYS, "sizeof(struct mtconfiginfo) does not match!");
                        return -EFAULT;
                }
 
                /* check for valid user address */
                error = verify_area(VERIFY_WRITE, (void *) ioarg, sizeof(qic02_tape_dynconf));
                if (error)
                        return error;
                /* copy current settings to user space */
                stp = (char *) &qic02_tape_dynconf;
                argp = (char *) ioarg;
                for (i=0; i<sizeof(qic02_tape_dynconf); i++)
                        put_user(*stp++, argp++);
                return 0;
 
        } else if (c == (MTIOCSETCONFIG & IOCCMD_MASK)) {
                static int qic02_get_resources(void), qic02_release_resources(void);
 
                /* One should always do a MTIOCGETCONFIG first, then update
                 * user-settings, then write back with MTIOCSETCONFIG.
                 * Re-open() the device before actual use to make sure
                 * everything is initialized.
                 */
                if (((iocmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT) != sizeof(struct mtconfiginfo)) {
                        tpqputs(TPQD_ALWAYS, "sizeof(struct mtconfiginfo) does not match!");
                        return -EFAULT;
                }
                if (!suser())
                        return -EPERM;
                if ((doing_read!=NO) || (doing_write!=NO))
                        return -EBUSY;
                error = verify_area(VERIFY_READ, (char *) ioarg, sizeof(qic02_tape_dynconf));
                if (error)
                        return error;
 
                /* copy struct from user space to kernel space */
                stp = (char *) &qic02_tape_dynconf;
                argp = (char *) ioarg;
                for (i=0; i<sizeof(qic02_tape_dynconf); i++)
                        *stp++ = get_user(argp++);
                if (status_zombie==NO)
                        qic02_release_resources();      /* and go zombie */
                if (update_ifc_masks(qic02_tape_dynconf.ifc_type))
                        return -EIO;
                if (qic02_get_resources())
                        return -ENXIO;
                return 0;
 
        }
        if (status_zombie==YES) {
                tpqputs(TPQD_ALWAYS, "Configs not set");
                return -ENXIO;
        }
#endif
        if (c == (MTIOCTOP & IOCCMD_MASK)) {
 
                /* Compare expected struct size and actual struct size. This
                 * is useful to catch programs compiled with old #includes.
                 */
                if (((iocmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT) != sizeof(struct mtop)) {
                        tpqputs(TPQD_ALWAYS, "sizeof(struct mtop) does not match!");
                        return -EFAULT;
                }
                error = verify_area(VERIFY_READ, (char *) ioarg, sizeof(operation));
                if (error)
                        return error;
 
                /* copy mtop struct from user space to kernel space */
                stp = (char *) &operation;
                argp = (char *) ioarg;
                for (i=0; i<sizeof(operation); i++)
                        *stp++ = get_user(argp++);
 
                /* ---note: mt_count is signed, negative seeks must be
                 * ---      translated to seeks in opposite direction!
                 * (only needed for Sun-programs, I think.)
                 */
                /* ---note: MTFSF with count 0 should position the
                 * ---      tape at the beginning of the current file.
                 */
 
                if (TP_DIAGS(current_tape_dev))
                        printk("OP op=%4x, count=%4x\n", operation.mt_op, operation.mt_count);
 
                if (operation.mt_count < 0)
                        tpqputs(TPQD_ALWAYS, "Warning: negative mt_count ignored");
 
                ioctl_status.mt_resid = operation.mt_count;
                if (operation.mt_op == MTSEEK) {
                        if (!TP_HAVE_SEEK)
                                return -ENOTTY;
                        seek_addr_buf[0] = (operation.mt_count>>16)&0xff;
                        seek_addr_buf[1] = (operation.mt_count>>8)&0xff;
                        seek_addr_buf[2] = (operation.mt_count)&0xff;
                        if (operation.mt_count>>24)
                                return -EINVAL;
                        if ((error = do_ioctl_cmd(operation.mt_op)) != 0)
                                return error;
                        ioctl_status.mt_resid = 0;
                } else {
                        while (operation.mt_count > 0) {
                                operation.mt_count--;
                                if ((error = do_ioctl_cmd(operation.mt_op)) != 0)
                                        return error;
                                ioctl_status.mt_resid = operation.mt_count;
                        }
                }
                return 0;
 
        } else if (c == (MTIOCGET & IOCCMD_MASK)) {
                if (TP_DIAGS(current_tape_dev))
                        printk("GET ");
 
                /* compare expected struct size and actual struct size */
                if (((iocmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT) != sizeof(struct mtget)) {
                        tpqputs(TPQD_ALWAYS, "sizeof(struct mtget) does not match!");
                        return -EFAULT;
                }
 
                /* check for valid user address */
                error = verify_area(VERIFY_WRITE, (void *) ioarg, sizeof(ioctl_status));
                if (error)
                        return error;
 
                /* It appears (gmt(1)) that it is normal behaviour to
                 * first set the status with MTNOP, and then to read
                 * it out with MTIOCGET
                 */
 
                /* copy results to user space */
                stp = (char *) &ioctl_status;
                argp = (char *) ioarg;
                for (i=0; i<sizeof(ioctl_status); i++)
                        put_user(*stp++, argp++);
                return 0;
 
 
        } else if (TP_HAVE_TELL && (c == (MTIOCPOS & IOCCMD_MASK))) {
                if (TP_DIAGS(current_tape_dev))
                        printk("POS ");
 
                /* compare expected struct size and actual struct size */
                if (((iocmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT) != sizeof(struct mtpos)) {
                        tpqputs(TPQD_ALWAYS, "sizeof(struct mtpos) does not match!");
                        return -EFAULT;
                }
 
                /* check for valid user address */
                error = verify_area(VERIFY_WRITE, (void *) ioarg, sizeof(ioctl_tell));
                if (error)
                        return error;
 
                tpqputs(TPQD_IOCTLS, "MTTELL reading block address");
                if ((doing_read==YES) || (doing_write==YES))
                        finish_rw(AR_QCMDV_TELL_BLK);
 
                c = rdstatus((char *) blk_addr, sizeof(blk_addr), AR_QCMDV_TELL_BLK);
                if (c!=TE_OK)
                        return -EIO;
 
                ioctl_tell.mt_blkno = (blk_addr[3] << 16) | (blk_addr[4] << 8) | blk_addr[5];
 
                /* copy results to user space */
                stp = (char *) &ioctl_tell;
                argp = (char *) ioarg;
                for (i=0; i<sizeof(ioctl_tell); i++)
                        put_user(*stp++, argp++);
                return 0;
 
        } else
                return -ENOTTY; /* Other cmds not supported. */
} /* qic02_tape_ioctl */
 
 
 
/* These are (most) of the interface functions: */
static struct file_operations qic02_tape_fops = {
        qic02_tape_lseek,               /* not allowed */
        qic02_tape_read,                /* read */
        qic02_tape_write,               /* write */
        NULL,                           /* readdir not allowed */
        NULL,                           /* select ??? */
        qic02_tape_ioctl,               /* ioctl */
        NULL,                           /* mmap not allowed */
        qic02_tape_open,                /* open */
        qic02_tape_release,             /* release */
        NULL,                           /* fsync */
        NULL,                           /* fasync */
        NULL,                           /* check_media_change */
        NULL                            /* revalidate */
};
 
/* align `a' at `size' bytes. `size' must be a power of 2 */
static inline unsigned long const align_buffer(unsigned long a, unsigned size)
{
        if (a & (size-1))                       /* if not aligned */
                return (a | (size-1)) + 1;
        else                                    /* else is aligned */
                return a;
}
 
 
 
static void qic02_release_resources(void)
{
        free_irq(QIC02_TAPE_IRQ, NULL);
        free_dma(QIC02_TAPE_DMA);
        status_zombie = YES;
} /* qic02_release_resources */
 
 
 
 
static int qic02_get_resources(void)
{
        /* First perform some checks. If one of them fails,
         * the tape driver will not be registered to the system.
         */
        if (QIC02_TAPE_IRQ>16) {
                tpqputs(TPQD_ALWAYS, "Bogus interrupt number.");
                return -1;
        }
 
        /* for DYNCONF, allocating DMA & IRQ should not be done until
         * the config parameters have been set using MTSETCONFIG.
         */
 
        /* get IRQ */
        if (request_irq(QIC02_TAPE_IRQ, qic02_tape_interrupt, SA_INTERRUPT, "QIC-02", NULL)) {
                printk(TPQIC02_NAME ": can't allocate IRQ%d for QIC-02 tape\n",
                        QIC02_TAPE_IRQ);
                status_zombie = YES;
                return -1;
        }
 
        /* After IRQ, allocate DMA channel */
        if (request_dma(QIC02_TAPE_DMA,"QIC-02")) {
                printk(TPQIC02_NAME ": can't allocate DMA%d for QIC-02 tape\n",
                        QIC02_TAPE_DMA);
                free_irq(QIC02_TAPE_IRQ, NULL);
                status_zombie = YES;
                return -1;
        }
 
        printk(TPQIC02_NAME ": Settings: IRQ %d, DMA %d, IO 0x%x, IFC %s\n",
                QIC02_TAPE_IRQ, QIC02_TAPE_DMA,
                ((QIC02_TAPE_IFC==ARCHIVE) || (QIC02_TAPE_IFC==MOUNTAIN))?
                        QIC02_CMD_PORT : QIC02_STAT_PORT,
                (QIC02_TAPE_IFC==MOUNTAIN)? "Mountain" :
                        ((QIC02_TAPE_IFC==ARCHIVE)? "Archive" : "Wangtek"));
 
        if (tape_reset(0)!=TE_OK || tp_sense(TP_WRP|TP_POR|TP_CNI)!=TE_OK) {
                /* No drive detected, so vanish */
                tpqputs(TPQD_ALWAYS, "No drive detected -- releasing irq and dma.");
                status_dead = YES;
                qic02_release_resources();
                return -1;
        }
 
        /* All should be ok now */
        status_zombie = NO;
        return 0;
} /* qic02_get_resources */
 
 
int qic02_tape_init(void)
        /* Shouldn't this be a caddr_t ? */
{
 
        if (TPSTATSIZE != 6) {
                printk(TPQIC02_NAME ": internal error: tpstatus struct incorrect!\n");
                return -ENODEV;
        }
        if ((TPQBUF_SIZE<512) || (TPQBUF_SIZE>=0x10000)) {
                printk(TPQIC02_NAME ": internal error: DMA buffer size out of range\n");
                return -ENODEV;
        }
 
        QIC02_TAPE_DEBUG = TPQD_DEFAULT_FLAGS;
 
        current_tape_dev = MKDEV(QIC02_TAPE_MAJOR, 0);
 
#ifndef CONFIG_QIC02_DYNCONF
        printk(TPQIC02_NAME ": IRQ %d, DMA %d, IO 0x%x, IFC %s, %s, %s\n",
                 QIC02_TAPE_IRQ, QIC02_TAPE_DMA,
# if QIC02_TAPE_IFC == WANGTEK
                 QIC02_STAT_PORT, "Wangtek",
# elif QIC02_TAPE_IFC == ARCHIVE
                 QIC02_CMD_PORT, "Archive",
# elif QIC02_TAPE_IFC == MOUNTAIN
                 QIC02_CMD_PORT, "Mountain",
# else
#  error
# endif
                 rcs_revision, rcs_date);
        if (qic02_get_resources())
                return -ENODEV;
#else
        printk(TPQIC02_NAME ": Runtime config, %s, %s\n",
                 rcs_revision, rcs_date);
 
        QIC02_TAPE_IRQ = BOGUS_IRQ;     /* invalid value */
#endif
 
        printk(TPQIC02_NAME ": DMA buffers: %u blocks", NR_BLK_BUF);
 
        /* Setup the page-address for the dma transfer.
         * This assumes a one-to-one identity mapping between
         * kernel addresses and physical memory.
         */
        buffaddr = align_buffer((unsigned long) &qic02_tape_buf, TAPE_BLKSIZE);
        printk(", at address 0x%lx (0x%lx)\n", buffaddr, (unsigned long) &qic02_tape_buf);
 
#ifndef CONFIG_MAX_16M
        if (buffaddr+TPQBUF_SIZE>=0x1000000) {
                printk(TPQIC02_NAME ": DMA buffer *must* be in lower 16MB\n");
                return -ENODEV;
        }
#endif
 
        /* If we got this far, install driver functions */
        if (register_chrdev(QIC02_TAPE_MAJOR, TPQIC02_NAME, &qic02_tape_fops)) {
                printk(TPQIC02_NAME ": Unable to get chrdev major %d\n", QIC02_TAPE_MAJOR);
#ifndef CONFIG_QIC02_DYNCONF
                free_irq(QIC02_TAPE_IRQ, NULL);
                free_dma(QIC02_TAPE_DMA);
#endif
                return -ENODEV;
        }
 
        /* prepare timer */
        TIMEROFF;
        timer_table[QIC02_TAPE_TIMER].expires = 0;
        timer_table[QIC02_TAPE_TIMER].fn = qic02_tape_times_out;
 
#ifndef CONFIG_QIC02_DYNCONF
        if (tape_reset(0)!=TE_OK || tp_sense(TP_WRP|TP_POR|TP_CNI)!=TE_OK) {
                /* No drive detected, so vanish */
                tpqputs(TPQD_ALWAYS, "No drive detected -- driver going on vacation...");
                status_dead = YES;
                free_irq(QIC02_TAPE_IRQ, NULL);
                free_dma(QIC02_TAPE_DMA);
                unregister_chrdev(QIC02_TAPE_MAJOR, TPQIC02_NAME);
                return -ENODEV;
        } else {
                if (is_exception()) {
                        tpqputs(TPQD_ALWAYS, "exception detected\n");
                        (void) tp_sense(TP_WRP|TP_POR|TP_CNI);
                }
        }
#endif
 
        /* initialize generic status for ioctl requests */
 
        ioctl_status.mt_type    = QIC02_TAPE_DRIVE;     /* MT_IS* id nr */
 
        ioctl_status.mt_resid   = 0;     /* ---residual count */
        ioctl_status.mt_gstat   = 0;     /* ---generic status */
        ioctl_status.mt_erreg   = 0;     /* not used */
        ioctl_status.mt_fileno  = 0;     /* number of current file on tape */
        ioctl_status.mt_blkno   = 0;     /* number of current (logical) block */
 
        return 0;
} /* qic02_tape_init */
 
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[/] [or1k_old/] [trunk/] [uclinux/] [uClinux-2.0.x/] [drivers/] [char/] [tpqic02.c] - Blame information for rev 1782

Line No.	Rev	Author	Line
1	199	simons	`/* $Id: tpqic02.c,v 1.1.1.1 2001-09-10 07:44:17 simons Exp $`
2			`*`
3			`* Driver for tape drive support for Linux-i386 1.1.58`
4			`*`
5			`* Copyright (c) 1992, 1993, 1994 by H. H. Bergman. All rights reserved.`
6			`* Current e-mail address: hennus@sky.ow.org [This is a UUCP link.]`
7			`* [If you are unable to reach me directly, try the TAPE mailing list`
8			`* channel on linux-activists@niksula.hut.fi using "X-Mn-Key: TAPE" as`
9			`* the first line in your message.]`
10			`*`
11			`* Distribution of this program in executable form is only allowed if`
12			`* all of the corresponding source files are made available through the same`
13			`* medium at no extra cost.`
14			`*`
15			`* I will not accept any responsibility for damage caused directly or`
16			`* indirectly by this program, or code derived from this program.`
17			`*`
18			`* Use this code at your own risk. Don't blame me if it destroys your data!`
19			`* Make sure you have a backup before you try this code.`
20			`*`
21			`* If you make changes to my code and redistribute it in source or binary`
22			`* form you must make it clear to even casual users of your code that you`
23			`* have modified my code, clearly point out what the changes exactly are`
24			`* (preferably in the form of a context diff file), how to undo your changes,`
25			`* where the original can be obtained, and that complaints/requests about the`
26			`* modified code should be directed to you instead of me.`
27			`*`
28			`* This driver was partially inspired by the 'wt' driver in the 386BSD`
29			`* source distribution, which carries the following copyright notice:`
30			`*`
31			`* Copyright (c) 1991 The Regents of the University of California.`
32			`* All rights reserved.`
33			`*`
34			`* You are not allowed to change this line nor the text above.`
35			`*`
36			`* $Log: not supported by cvs2svn $`
37			`* Revision 1.1.1.1 2001/07/02 17:58:25 simons`
38			`* Initial revision`
39			`*`
40			`* Revision 0.4.1.5 1994/10/29 02:46:13 root`