Initial import, 0.1 + pk 0.2.4-B1

1 files changed, 1774 insertions, 0 deletions

diff --git a/sys/scsi/st.c b/sys/scsi/st.c
new file mode 100644
index 0000000..e896902
--- /dev/null
+++ b/sys/scsi/st.c
@@ -0,0 +1,1774 @@
+/*
+ * Written by Julian Elischer (julian@tfs.com)
+ * for TRW Financial Systems for use under the MACH(2.5) operating system.
+ *
+ * TRW Financial Systems, in accordance with their agreement with Carnegie
+ * Mellon University, makes this software available to CMU to distribute
+ * or use in any manner that they see fit as long as this message is kept with
+ * the software. For this reason TFS also grants any other persons or
+ * organisations permission to use or modify this software.
+ *
+ * TFS supplies this software to be publicly redistributed
+ * on the understanding that TFS is not responsible for the correct
+ * functioning of this software in any circumstances.
+ *
+ *
+ * PATCHES MAGIC                LEVEL   PATCH THAT GOT US HERE
+ * --------------------         -----   ----------------------
+ * CURRENT PATCH LEVEL:         1       00098
+ * --------------------         -----   ----------------------
+ *
+ * 16 Feb 93	Julian Elischer		ADDED for SCSI system
+ */
+
+/*
+ * Ported to run under 386BSD by Julian Elischer (julian@tfs.com) Sept 1992
+ */
+
+
+/*
+ * To do:
+ * work out some better way of guessing what a good timeout is going
+ * to be depending on whether we expect to retension or not.
+ *
+ */
+
+#include	<sys/types.h>
+#include	<st.h>
+
+#include <sys/param.h>
+#include <sys/systm.h>
+
+#include <sys/errno.h>
+#include <sys/ioctl.h>
+#include <sys/buf.h>
+#include <sys/proc.h>
+#include <sys/user.h>
+#include <sys/mtio.h>
+
+#if defined(OSF)
+#define SECSIZE	512
+#endif /* defined(OSF) */
+
+#include <scsi/scsi_all.h>
+#include <scsi/scsi_tape.h>
+#include <scsi/scsiconf.h>
+
+
+long int ststrats,stqueues;
+
+
+#define PAGESIZ 	4096
+#define STQSIZE		4
+#define	ST_RETRIES	4
+
+
+#define MODE(z)		(  (minor(z)       & 0x03) )
+#define DSTY(z)         ( ((minor(z) >> 2) & 0x03) )
+#define UNIT(z)		(  (minor(z) >> 4) )
+
+#define DSTY_QIC120  3
+#define DSTY_QIC150  2
+#define DSTY_QIC525  1
+
+#define QIC120     0x0f
+#define QIC150     0x10
+#define QIC525     0x11
+
+
+
+
+#ifndef	__386BSD__
+struct buf stbuf[NST][STQSIZE]; 	/* buffer for raw io (one per device) */
+struct buf *stbuf_free[NST]; 	/* queue of free buffers for raw io */
+#endif	__386BSD__
+struct buf st_buf_queue[NST];
+int	ststrategy();
+void	stminphys();
+struct	scsi_xfer st_scsi_xfer[NST];
+int	st_xfer_block_wait[NST];
+
+#if defined(OSF)
+caddr_t		st_window[NST];
+#endif /* defined(OSF) */
+#ifndef	MACH
+#define ESUCCESS 0
+#endif	MACH
+
+int	st_info_valid[NST];	/* the info about the device is valid */
+int	st_initialized[NST] ;
+int	st_debug = 0;
+
+int stattach();
+int st_done();
+struct	st_data
+{
+	int	flags;
+	struct	scsi_switch *sc_sw;	/* address of scsi low level switch */
+	int	ctlr;			/* so they know which one we want */
+	int	targ;			/* our scsi target ID */
+	int	lu;			/* out scsi lu */
+	int	blkmin;			/* min blk size */
+	int	blkmax;			/* max blk size */
+	int	numblks;		/* nominal blocks capacity */
+	int	blksiz;			/* nominal block size */
+}st_data[NST];
+#define ST_OPEN		0x01
+#define	ST_NOREWIND	0x02
+#define	ST_WRITTEN	0x04
+#define	ST_FIXEDBLOCKS	0x10
+#define	ST_AT_FILEMARK	0x20
+#define	ST_AT_EOM	0x40
+
+#define	ST_PER_ACTION	(ST_AT_FILEMARK | ST_AT_EOM)
+#define	ST_PER_OPEN	(ST_OPEN | ST_NOREWIND | ST_WRITTEN | ST_PER_ACTION)
+#define	ST_PER_MEDIA	ST_FIXEDBLOCKS
+
+static	int	next_st_unit = 0;
+/***********************************************************************\
+* The routine called by the low level scsi routine when it discovers	*
+* A device suitable for this driver					*
+\***********************************************************************/
+
+int	stattach(ctlr,targ,lu,scsi_switch)
+struct	scsi_switch *scsi_switch;
+{
+	int	unit,i;
+	unsigned char *tbl;
+	struct st_data *st;
+
+	if(scsi_debug & PRINTROUTINES) printf("stattach: ");
+	/*******************************************************\
+	* Check we have the resources for another drive		*
+	\*******************************************************/
+	unit = next_st_unit++;
+	if( unit >= NST)
+	{
+		printf("Too many scsi tapes..(%d > %d) reconfigure kernel",(unit + 1),NST);
+		return(0);
+	}
+	st = st_data + unit;
+	/*******************************************************\
+	* Store information needed to contact our base driver	*
+	\*******************************************************/
+	st->sc_sw	=	scsi_switch;
+	st->ctlr	=	ctlr;
+	st->targ	=	targ;
+	st->lu	=	lu;
+
+	/*******************************************************\
+	* Use the subdriver to request information regarding	*
+	* the drive. We cannot use interrupts yet, so the	*
+	* request must specify this.				*
+	\*******************************************************/
+	if((st_mode_sense(unit,  SCSI_NOSLEEP |  SCSI_NOMASK | SCSI_SILENT)))
+	{
+		printf("	st%d: scsi tape drive, %d blocks of %d bytes\n",
+			unit, st->numblks, st->blksiz);
+	}
+	else
+	{
+		printf("	st%d: scsi tape drive :- offline\n", unit);
+	}
+	/*******************************************************\
+	* Set up the bufs for this device			*
+	\*******************************************************/
+#ifndef	__386BSD__
+	stbuf_free[unit] = (struct buf *)0;
+	for (i = 1; i < STQSIZE; i++)
+	{
+		stbuf[unit][i].b_forw = stbuf_free[unit];
+		stbuf_free[unit]=&stbuf[unit][i];
+	}
+#endif	__386BSD__
+	st_buf_queue[unit].b_active	=	0;
+	st_buf_queue[unit].b_actf	=	st_buf_queue[unit].b_actl = 0;
+	st_initialized[unit] = 1;
+
+#if defined(OSF)
+  	st_window[unit] = (caddr_t)alloc_kva(SECSIZE*256+PAGESIZ);
+#endif /* defined(OSF) */
+
+	return;
+
+}
+
+
+
+/*******************************************************\
+*	open the device.				*
+\*******************************************************/
+stopen(dev)
+{
+	int errcode = 0;
+	int unit,mode,dsty;
+        int dsty_code;
+	struct st_data *st;
+	unit = UNIT(dev);
+	mode = MODE(dev);
+	dsty = DSTY(dev);
+	st = st_data + unit;
+
+	/*******************************************************\
+	* Check the unit is legal                               *
+	\*******************************************************/
+	if ( unit >= NST )
+	{
+		errcode = ENXIO;
+		return(errcode);
+	}
+	/*******************************************************\
+	* Only allow one at a time				*
+	\*******************************************************/
+	if(st->flags & ST_OPEN)
+	{
+		errcode = ENXIO;
+		goto bad;
+	}
+	/*******************************************************\
+	* Set up the mode flags according to the minor number	*
+	* ensure all open flags are in a known state		*
+	\*******************************************************/
+	st->flags &= ~ST_PER_OPEN;
+	switch(mode)
+	{
+	case	2:
+	case	0:
+		st->flags &= ~ST_NOREWIND;
+		break;
+	case	3:
+	case	1:
+		st->flags |= ST_NOREWIND;
+		break;
+	default:
+		printf("st%d: Bad mode (minor number)%d\n",unit,mode);
+		return(EINVAL);
+	}
+        /*******************************************************\
+        * Check density code: 0 is drive default		*
+        \*******************************************************/
+        switch(dsty)
+	{
+	case	0:		dsty_code = 0;		break;
+	case	DSTY_QIC120:	dsty_code = QIC120;	break;
+	case	DSTY_QIC150:	dsty_code = QIC150;	break;
+	case	DSTY_QIC525:	dsty_code = QIC525;	break;
+	default:
+		printf("st%d: Bad density (minor number)%d\n",unit,dsty);
+		return(EINVAL);
+	}
+	if(scsi_debug & (PRINTROUTINES | TRACEOPENS))
+		printf("stopen: dev=0x%x (unit %d (of %d))\n"
+				,   dev,      unit,   NST);
+	/*******************************************************\
+	* Make sure the device has been initialised		*
+	\*******************************************************/
+
+	if (!st_initialized[unit])
+		return(ENXIO);
+	/*******************************************************\
+	* Check that it is still responding and ok.		*
+	\*******************************************************/
+
+	if(scsi_debug & TRACEOPENS)
+		printf("device is ");
+	if (!(st_req_sense(unit, 0)))
+	{
+		errcode = ENXIO;
+		if(scsi_debug & TRACEOPENS)
+			printf("not responding\n");
+		goto bad;
+	}
+	if(scsi_debug & TRACEOPENS)
+		printf("ok\n");
+
+	if(!(st_test_ready(unit,0)))
+	{
+		printf("st%d not ready\n",unit);
+		return(EIO);
+	}
+
+	if(!st_info_valid[unit])		/* is media new? */
+		if(!st_load(unit,LD_LOAD,0))
+		{
+			return(EIO);
+		}
+
+	if(!st_rd_blk_lim(unit,0))
+	{
+		return(EIO);
+	}
+
+	if(!st_mode_sense(unit,0))
+	{
+		return(EIO);
+	}
+
+	if(!st_mode_select(unit,0,dsty_code))
+	{
+		return(EIO);
+	}
+
+	st_info_valid[unit] = TRUE;
+
+	st_prevent(unit,PR_PREVENT,0); /* who cares if it fails? */
+
+	/*******************************************************\
+	* Load the physical device parameters			*
+	\*******************************************************/
+	if(scsi_debug & TRACEOPENS)
+		printf("Params loaded ");
+
+
+	st->flags |= ST_OPEN;
+
+bad:
+	return(errcode);
+}
+
+/*******************************************************\
+* close the device.. only called if we are the LAST	*
+* occurence of an open device				*
+\*******************************************************/
+stclose(dev)
+{
+	unsigned char unit,mode;
+	struct	st_data *st;
+
+	unit = UNIT(dev);
+	mode = MODE(dev);
+	st = st_data + unit;
+
+	if(scsi_debug & TRACEOPENS)
+		printf("Closing device");
+	if(st->flags & ST_WRITTEN)
+	{
+		st_write_filemarks(unit,1,0);
+	}
+	st->flags &= ~ST_WRITTEN;
+	switch(mode)
+	{
+	case	0:
+		st_rewind(unit,FALSE,SCSI_SILENT);
+		st_prevent(unit,PR_ALLOW,SCSI_SILENT);
+		break;
+	case	1:
+		st_prevent(unit,PR_ALLOW,SCSI_SILENT);
+		break;
+	case	2:
+		st_rewind(unit,FALSE,SCSI_SILENT);
+		st_prevent(unit,PR_ALLOW,SCSI_SILENT);
+		st_load(unit,LD_UNLOAD,SCSI_SILENT);
+		break;
+	case	3:
+		st_prevent(unit,PR_ALLOW,SCSI_SILENT);
+		st_load(unit,LD_UNLOAD,SCSI_SILENT);
+		break;
+	default:
+		printf("st%d:close: Bad mode (minor number)%d how's it open?\n"
+				,unit,mode);
+		return(EINVAL);
+	}
+	st->flags &= ~ST_PER_OPEN;
+	return(0);
+}
+
+#ifndef	__386BSD__
+/*******************************************************\
+* Get ownership of this unit's buf			*
+* If need be, sleep on it, until it comes free		*
+\*******************************************************/
+struct buf *
+st_get_buf(unit) {
+	struct buf *rc;
+
+	while (!(rc = stbuf_free[unit]))
+		sleep((caddr_t)&stbuf_free[unit], PRIBIO+1);
+	stbuf_free[unit] = stbuf_free[unit]->b_forw;
+	rc->b_error = 0;
+	rc->b_resid = 0;
+	rc->b_flags = 0;
+	return(rc);
+}
+
+/*******************************************************\
+* Free this unit's buf, wake processes waiting for it	*
+\*******************************************************/
+st_free_buf(unit,bp)
+struct buf *bp;
+{
+	if (!stbuf_free[unit])
+		wakeup((caddr_t)&stbuf_free[unit]);
+	bp->b_forw = stbuf_free[unit];
+	stbuf_free[unit] = bp;
+}
+	
+
+/*******************************************************\
+* Get the buf for this unit and use physio to do it	*
+\*******************************************************/
+stread(dev,uio)
+register short  dev;
+struct uio 	*uio;
+{
+	int	unit = UNIT(dev);
+	struct buf *bp = st_get_buf(unit);
+	int rc;
+	rc = physio(ststrategy, bp, dev, B_READ, stminphys, uio);
+	st_free_buf(unit,bp);
+	return(rc);
+}
+
+/*******************************************************\
+* Get the buf for this unit and use physio to do it	*
+\*******************************************************/
+stwrite(dev,uio)
+dev_t	 	dev;
+struct uio	*uio;
+{
+	int	unit = UNIT(dev);
+	struct buf *bp = st_get_buf(unit);
+	int rc;
+
+	rc = physio(ststrategy, bp, dev, B_WRITE, stminphys, uio);
+	st_free_buf(unit,bp);
+	return(rc);
+}
+
+
+#endif	__386BSD__
+/*******************************************************\
+* trim the size of the transfer if needed,		*
+* called by physio					*
+* basically the smaller of our min and the scsi driver's*
+* minphys						*
+\*******************************************************/
+void	stminphys(bp)
+struct buf	*bp;
+{
+	(*(st_data[UNIT(bp->b_dev)].sc_sw->scsi_minphys))(bp);
+}
+
+/*******************************************************\
+* Actually translate the requested transfer into	*
+* one the physical driver can understand		*
+* The transfer is described by a buf and will include	*
+* only one physical transfer.				*
+\*******************************************************/
+
+int	ststrategy(bp)
+struct	buf	*bp;
+{
+	struct	buf	*dp;
+	unsigned char unit;
+	unsigned int opri;
+
+	ststrats++;
+	unit = UNIT((bp->b_dev));
+	if(scsi_debug & PRINTROUTINES) printf("\nststrategy ");
+	if(scsi_debug & SHOWREQUESTS) printf("st%d: %d bytes @ blk%d\n",
+					unit,bp->b_bcount,bp->b_blkno);
+	/*******************************************************\
+	* If it's a null transfer, return immediatly		*
+	\*******************************************************/
+	if (bp->b_bcount == 0) {
+		goto done;
+	}
+
+	/*******************************************************\
+	* Odd sized request on fixed drives are verboten	*
+	\*******************************************************/
+	if((st_data[unit].flags & ST_FIXEDBLOCKS)
+		&& bp->b_bcount % st_data[unit].blkmin)
+	{
+		printf("st%d: bad request, must be multiple of %d\n",
+			unit, st_data[unit].blkmin);
+		bp->b_error = EIO;
+		goto bad;
+	}
+
+#ifdef	__386BSD__
+	stminphys(bp);
+#endif	__386BSD__
+	opri = splbio();
+	dp = &st_buf_queue[unit];
+
+	/*******************************************************\
+	* Place it in the queue of disk activities for this tape*
+	* at the end						*
+	\*******************************************************/
+	while ( dp->b_actf) 
+	{
+		dp = dp->b_actf;
+	}	
+	dp->b_actf = bp;
+	bp->b_actf = NULL;
+
+	/*******************************************************\
+	* Tell the device to get going on the transfer if it's	*
+	* not doing anything, otherwise just wait for completion*
+	\*******************************************************/
+	ststart(unit);
+
+	splx(opri);
+	return;
+bad:
+	bp->b_flags |= B_ERROR;
+done:
+	/*******************************************************\
+	* Correctly set the buf to indicate a completed xfer	*
+	\*******************************************************/
+	iodone(bp);
+	return;
+}
+
+
+/***************************************************************\
+* ststart looks to see if there is a buf waiting for the device	*
+* and that the device is not already busy. If both are true,	*
+* It deques the buf and creates a scsi command to perform the	*
+* transfer in the buf. The transfer request will call st_done	*
+* on completion, which will in turn call this routine again	*
+* so that the next queued transfer is performed.		*
+* The bufs are queued by the strategy routine (ststrategy)	*
+*								*
+* This routine is also called after other non-queued requests	*
+* have been made of the scsi driver, to ensure that the queue	*
+* continues to be drained.					*
+\***************************************************************/
+/* ststart() is called at splbio */
+ststart(unit)
+{
+	int			drivecount;
+	register struct buf	*bp = 0;
+	register struct buf	*dp;
+	struct	scsi_xfer	*xs;
+	struct	scsi_rw_tape	cmd;
+	int			blkno, nblk;
+	struct	st_data *st;
+
+
+	st = st_data + unit;
+
+	if(scsi_debug & PRINTROUTINES) printf("ststart%d ",unit);
+	/*******************************************************\
+	* See if there is a buf to do and we are not already	*
+	* doing one						*
+	\*******************************************************/
+	xs=&st_scsi_xfer[unit];
+	if(xs->flags & INUSE)
+	{
+		return;    /* unit already underway */
+	}
+trynext:
+	if(st_xfer_block_wait[unit]) /* a special awaits, let it proceed first */
+	{
+		wakeup(&st_xfer_block_wait[unit]);
+		return;
+	}
+
+	dp = &st_buf_queue[unit];
+	if ((bp = dp->b_actf) != NULL)
+	{
+		dp->b_actf = bp->b_actf;
+	}
+	else /* no work to do */
+	{
+		return;
+	}
+	xs->flags = INUSE;    /* Now ours */
+
+
+	/*******************************************************\
+	* We have a buf, now we should move the data into	*
+	* a scsi_xfer definition and try start it		*
+	\*******************************************************/
+
+	/*******************************************************\
+	*  If we are at a filemark but have not reported it yet	*
+	* then we should report it now				*
+	\*******************************************************/
+	if(st->flags & ST_AT_FILEMARK)
+	{
+		bp->b_error = 0;
+		bp->b_flags |= B_ERROR;	/* EOF*/
+		st->flags &= ~ST_AT_FILEMARK;
+		biodone(bp);
+		xs->flags = 0; /* won't need it now */
+		goto trynext;
+	}
+	/*******************************************************\
+	*  If we are at EOM but have not reported it yet	*
+	* then we should report it now				*
+	\*******************************************************/
+	if(st->flags & ST_AT_EOM)
+	{
+		bp->b_error = EIO;
+		bp->b_flags |= B_ERROR;
+		st->flags &= ~ST_AT_EOM;
+		biodone(bp);
+		xs->flags = 0; /* won't need it now */
+		goto trynext;
+	}
+	/*******************************************************\
+	*  Fill out the scsi command				*
+	\*******************************************************/
+	bzero(&cmd, sizeof(cmd));
+	if((bp->b_flags & B_READ) == B_WRITE)
+	{
+		st->flags |= ST_WRITTEN;
+		xs->flags |= SCSI_DATA_OUT;
+	}
+	else
+	{
+		xs->flags |= SCSI_DATA_IN;
+	}
+	cmd.op_code = (bp->b_flags & B_READ) 
+					? READ_COMMAND_TAPE
+					: WRITE_COMMAND_TAPE;
+
+	/*******************************************************\
+	* Handle "fixed-block-mode" tape drives by using the    *
+	* block count instead of the length.			*
+	\*******************************************************/
+	if(st->flags & ST_FIXEDBLOCKS)
+	{
+		cmd.fixed = 1;
+		lto3b(bp->b_bcount/st->blkmin,cmd.len);
+	}
+	else
+	{
+		lto3b(bp->b_bcount,cmd.len);
+	}
+
+	/*******************************************************\
+	* Fill out the scsi_xfer structure			*
+	*	Note: we cannot sleep as we may be an interrupt	*
+	\*******************************************************/
+	xs->flags	|=	SCSI_NOSLEEP;
+	xs->adapter	=	st->ctlr;
+	xs->targ	=	st->targ;
+	xs->lu		=	st->lu;
+	xs->retries	=	1;	/* can't retry on tape*/
+	xs->timeout	=	100000; /* allow 100 secs for retension */
+	xs->cmd		=	(struct	scsi_generic *)&cmd;
+	xs->cmdlen	=	sizeof(cmd);
+	xs->data	=	(u_char *)bp->b_un.b_addr;
+	xs->datalen	=	bp->b_bcount;
+	xs->resid	=	bp->b_bcount;
+	xs->when_done	=	st_done;
+	xs->done_arg	=	unit;
+	xs->done_arg2	=	(int)xs;
+	xs->error	=	XS_NOERROR;
+	xs->bp		=	bp;
+	/*******************************************************\
+	* Pass all this info to the scsi driver.		*
+	\*******************************************************/
+
+
+#if defined(OSF)||defined(FIX_ME)
+	if (bp->b_flags & B_PHYS) {
+	 	xs->data = (u_char*)map_pva_kva(bp->b_proc, bp->b_un.b_addr,
+			bp->b_bcount, st_window[unit],
+			(bp->b_flags&B_READ)?B_WRITE:B_READ);
+	} else {
+		xs->data = (u_char*)bp->b_un.b_addr;
+	}
+#endif /* defined(OSF) */
+
+	if ( (*(st->sc_sw->scsi_cmd))(xs) != SUCCESSFULLY_QUEUED)
+	{
+		printf("st%d: oops not queued",unit);
+		xs->error = XS_DRIVER_STUFFUP;
+		st_done(unit,xs);
+	}
+	stqueues++;
+}
+
+/*******************************************************\
+* This routine is called by the scsi interrupt when	*
+* the transfer is complete.
+\*******************************************************/
+int	st_done(unit,xs)
+int	unit;
+struct	scsi_xfer	*xs;
+{
+	struct	buf		*bp;
+	int	retval;
+
+	if(scsi_debug & PRINTROUTINES) printf("st_done%d ",unit);
+	if (! (xs->flags & INUSE))
+		panic("scsi_xfer not in use!");
+	if(bp = xs->bp)
+	{
+		switch(xs->error)
+		{
+		case	XS_NOERROR:
+			bp->b_flags &= ~B_ERROR;
+			bp->b_error = 0;
+			bp->b_resid = 0;
+			break;
+		case	XS_SENSE:
+			retval = (st_interpret_sense(unit,xs));
+			if(retval)
+			{
+				/***************************************\
+				* We have a real error, the bit should	*
+				* be set to indicate this. The return	*
+				* value will contain the unix error code*
+				* that the error interpretation routine	*
+				* thought was suitable, so pass this	*
+				* value back in the buf structure.	*
+				* Furthermore we return information	*
+				* saying that no data was transferred	*
+				\***************************************/
+				bp->b_flags |= B_ERROR;
+				bp->b_error = retval;
+				bp->b_resid =  bp->b_bcount;
+				st_data[unit].flags 
+					&= ~(ST_AT_FILEMARK|ST_AT_EOM);
+			}
+			else
+			{
+			/***********************************************\
+			* The error interpretation code has declared	*
+			* that it wasn't a real error, or at least that	*
+			* we should be ignoring it if it was.		*
+			\***********************************************/
+			    if(xs->resid && ( xs->resid != xs->datalen ))
+			    {
+				/***************************************\
+				* Here we have the tricky part..	*
+				* We successfully read less data than	*
+				* we requested. (but not 0)		*
+				*------for variable blocksize tapes:----*
+				* UNDER 386BSD:				*
+				* We should legitimatly have the error	*
+				* bit set, with the error value set to 	*
+				* zero.. This is to indicate to the	*
+				* physio code that while we didn't get	*
+				* as much information as was requested,	*
+				* we did reach the end of the record	*
+				* and so physio should not call us	*
+				* again for more data... we have it all	*
+				* SO SET THE ERROR BIT!			*
+				*					*
+				* UNDER MACH:(CMU)			*
+				* To indicate the same as above, we	*
+				* need only have a non 0 resid that is	*
+				* less than the b_bcount, but the	*
+				* ERROR BIT MUST BE CLEAR! (sigh) 	*
+				*					*
+				* UNDER OSF1:				*
+				* To indicate the same as above, we	*
+				* need to have a non 0 resid that is	*
+				* less than the b_bcount, but the	*
+				* ERROR BIT MUST BE SET! (gasp)(sigh) 	*
+				*					*
+				*-------for fixed blocksize device------*
+				* We could have read some successful	*
+				* records before hitting		*
+				* the EOF or EOT. These must be passed	*
+				* to the user, before we report the 	*
+				* EOx. Only if there is no data for the	*
+				* user do we report it now. (via an EIO	*
+				* for EOM and resid == count for EOF).	*
+				* We will report the EOx NEXT time..	*
+				\***************************************/
+#ifdef	MACH /*osf and cmu varieties */
+#ifdef	OSF
+				bp->b_flags |= B_ERROR;
+#else	OSF
+				bp->b_flags &= ~B_ERROR;
+#endif	OSF
+#endif	MACH
+#ifdef	__386BSD__
+				bp->b_flags |= B_ERROR;
+#endif	__386BSD__
+				bp->b_error = 0;
+				bp->b_resid = xs->resid;
+				if((st_data[unit].flags & ST_FIXEDBLOCKS))
+				{
+					bp->b_resid *= st_data[unit].blkmin;
+					if(  (st_data[unit].flags & ST_AT_EOM)
+				 	  && (bp->b_resid == bp->b_bcount))
+					{
+						bp->b_error = EIO;
+						st_data[unit].flags
+							&= ~ST_AT_EOM;
+					}
+				}
+				xs->error = XS_NOERROR;
+				break;
+			    }
+			    else
+			    {
+				/***************************************\
+				* We have come out of the error handler	*
+				* with no error code.. we have also 	*
+				* not had an ili (would have gone to	*
+				* the previous clause). Now we need to	*
+				* distiguish between succesful read of	*
+				* no data (EOF or EOM) and successfull	*
+				* read of all requested data.		*
+				* At least all o/s agree that:		*
+				* 0 bytes read with no error is EOF	*
+				* 0 bytes read with an EIO is EOM	*
+				\***************************************/
+
+				bp->b_resid = bp->b_bcount;
+				if(st_data[unit].flags & ST_AT_FILEMARK)
+				{
+					st_data[unit].flags &= ~ST_AT_FILEMARK;
+					bp->b_flags &= ~B_ERROR;
+					bp->b_error = 0;
+					break;
+				}
+				if(st_data[unit].flags & ST_AT_EOM)
+				{
+					bp->b_flags |= B_ERROR;
+					bp->b_error = EIO;
+					st_data[unit].flags &= ~ST_AT_EOM;
+					break;
+				}
+				printf("st%d:error ignored\n" ,unit);
+			    }
+			}
+			break;
+
+		case    XS_TIMEOUT:
+			printf("st%d timeout\n",unit);
+			break;
+
+		case    XS_BUSY:        /* should retry */ /* how? */
+			/************************************************/
+			/* SHOULD put buf back at head of queue         */
+			/* and decrement retry count in (*xs)           */
+			/* HOWEVER, this should work as a kludge        */
+			/************************************************/
+			if(xs->retries--)
+			{
+				xs->flags &= ~ITSDONE;
+				xs->error = XS_NOERROR;
+				if ( (*(st_data[unit].sc_sw->scsi_cmd))(xs)
+					== SUCCESSFULLY_QUEUED)
+				{       /* don't wake the job, ok? */
+					return;
+				}
+				printf("device busy");
+				xs->flags |= ITSDONE;
+			}
+
+		case	XS_DRIVER_STUFFUP:
+			bp->b_flags |= B_ERROR;
+			bp->b_error = EIO;
+			break;
+		default:
+			printf("st%d: unknown error category from scsi driver\n"
+				,unit);
+		}	
+		biodone(bp);
+		xs->flags = 0;	/* no longer in use */
+		ststart(unit);		/* If there's another waiting.. do it */
+	}
+	else
+	{
+		wakeup(xs);
+	}
+}
+/*******************************************************\
+* Perform special action on behalf of the user		*
+* Knows about the internals of this device		*
+\*******************************************************/
+stioctl(dev, cmd, arg, mode)
+dev_t dev;
+int cmd;
+caddr_t arg;
+{
+	register i,j;
+	unsigned int opri;
+	int errcode = 0;
+	unsigned char unit;
+	int number,flags,ret;
+
+	/*******************************************************\
+	* Find the device that the user is talking about	*
+	\*******************************************************/
+	flags = 0;	/* give error messages, act on errors etc. */
+	unit = UNIT(dev);
+
+	switch(cmd)
+	{
+
+	case MTIOCGET:
+	    {
+		struct mtget *g = (struct mtget *) arg;
+
+		bzero(g, sizeof(struct mtget));
+		g->mt_type = 0x7;	/* Ultrix compat */ /*?*/
+		ret=TRUE;
+		break;
+	    }
+
+
+	case MTIOCTOP:
+	    {
+		struct mtop *mt = (struct mtop *) arg;
+
+		if (st_debug)
+			printf("[sctape_sstatus: %x %x]\n",
+				 mt->mt_op, mt->mt_count);
+
+
+
+		/* compat: in U*x it is a short */
+		number = mt->mt_count;
+		switch ((short)(mt->mt_op))
+		{
+		case MTWEOF:	/* write an end-of-file record */
+			ret = st_write_filemarks(unit,number,flags);
+			st_data[unit].flags &= ~ST_WRITTEN;
+			break;
+		case MTFSF:	/* forward space file */
+			ret = st_space(unit,number,SP_FILEMARKS,flags);
+			break;
+		case MTBSF:	/* backward space file */
+			ret = st_space(unit,-number,SP_FILEMARKS,flags);
+			break;
+		case MTFSR:	/* forward space record */
+			ret = st_space(unit,number,SP_BLKS,flags);
+			break;
+		case MTBSR:	/* backward space record */
+			ret = st_space(unit,-number,SP_BLKS,flags);
+			break;
+		case MTREW:	/* rewind */
+			ret = st_rewind(unit,FALSE,flags);
+			break;
+		case MTOFFL:	/* rewind and put the drive offline */
+			if((ret = st_rewind(unit,FALSE,flags)))
+			{
+				st_prevent(unit,PR_ALLOW,0);
+				ret = st_load(unit,LD_UNLOAD,flags);
+			}
+			else
+			{
+				printf("rewind failed, unit still loaded\n");
+			}
+			break;
+		case MTNOP:	/* no operation, sets status only */
+		case MTCACHE:	/* enable controller cache */
+		case MTNOCACHE:	/* disable controller cache */
+			ret = TRUE;;
+			break;
+		default:
+			return EINVAL;
+		}
+		break;
+	    }
+	case MTIOCIEOT:
+	case MTIOCEEOT:
+		ret=TRUE;
+		break;
+	}
+
+	return(ret?ESUCCESS:EIO);
+}
+
+
+/*******************************************************\
+* Check with the device that it is ok, (via scsi driver)*
+\*******************************************************/
+st_req_sense(unit, flags)
+int	flags;
+{
+	struct	scsi_sense_data sense;
+	struct	scsi_sense	scsi_cmd;
+
+	bzero(&scsi_cmd, sizeof(scsi_cmd));
+	scsi_cmd.op_code = REQUEST_SENSE;
+	scsi_cmd.length = sizeof(sense);
+
+	if (st_scsi_cmd(unit,
+			&scsi_cmd,
+			sizeof(scsi_cmd),
+			&sense,
+			sizeof(sense),
+			100000,
+			flags | SCSI_DATA_IN) != 0)
+	{
+		return(FALSE);
+	}
+	else 
+		return(TRUE);
+}
+
+/*******************************************************\
+* Get scsi driver to send a "are you ready" command	*
+\*******************************************************/
+st_test_ready(unit,flags)
+int	unit,flags;
+{
+	struct	scsi_test_unit_ready scsi_cmd;
+
+	bzero(&scsi_cmd, sizeof(scsi_cmd));
+	scsi_cmd.op_code = TEST_UNIT_READY;
+
+	if (st_scsi_cmd(unit,
+			&scsi_cmd,
+			sizeof(scsi_cmd),
+			0,
+			0,
+			100000,
+			flags) != 0) {
+		return(FALSE);
+	} else 
+		return(TRUE);
+}
+
+
+#ifdef	__STDC__
+#define b2tol(a)	(((unsigned)(a##_1) << 8) + (unsigned)a##_0 )
+#else
+#define b2tol(a)	(((unsigned)(a/**/_1) << 8) + (unsigned)a/**/_0 )
+#endif
+
+/*******************************************************\
+* Ask the drive what it's min and max blk sizes are.	*
+\*******************************************************/
+st_rd_blk_lim(unit, flags)
+int	unit,flags;
+{
+	struct	scsi_blk_limits scsi_cmd;
+	struct scsi_blk_limits_data scsi_blkl;
+	struct st_data *st = st_data + unit;
+	/*******************************************************\
+	* First check if we have it all loaded			*
+	\*******************************************************/
+	if (st_info_valid[unit]) goto done;
+
+	/*******************************************************\
+	* do a 'Read Block Limits'				*
+	\*******************************************************/
+	bzero(&scsi_cmd, sizeof(scsi_cmd));
+	scsi_cmd.op_code = READ_BLK_LIMITS;
+
+	/*******************************************************\
+	* do the command,	update the global values	*
+	\*******************************************************/
+	if (st_scsi_cmd(unit,
+			&scsi_cmd,
+			sizeof(scsi_cmd),
+			&scsi_blkl,
+			sizeof(scsi_blkl),
+			5000,
+			flags | SCSI_DATA_IN) != 0)
+	{
+		if(!(flags & SCSI_SILENT))
+			printf("could not get blk limits for unit %d\n", unit);
+		st_info_valid[unit] = FALSE;
+		return(FALSE);
+	} 
+	if (st_debug)
+	{
+		printf(" (%d <= blksiz <= %d\n) ",
+			b2tol(scsi_blkl.min_length),
+			_3btol(&scsi_blkl.max_length_2));
+	}
+	st->blkmin = b2tol(scsi_blkl.min_length);
+	st->blkmax = _3btol(&scsi_blkl.max_length_2);
+
+done:
+	if(st->blkmin && (st->blkmin == st->blkmax))
+	{
+		st->flags |= ST_FIXEDBLOCKS;
+	}
+	return(TRUE);
+}
+/*******************************************************\
+* Get the scsi driver to send a full inquiry to the	*
+* device and use the results to fill out the global 	*
+* parameter structure.					*
+\*******************************************************/
+st_mode_sense(unit, flags)
+int	unit,flags;
+{
+	struct scsi_mode_sense		scsi_cmd;
+	struct 
+	{
+		struct	scsi_mode_header_tape header;
+		struct	blk_desc	blk_desc;
+	}scsi_sense;
+	struct	st_data *st = st_data + unit;
+
+	/*******************************************************\
+	* First check if we have it all loaded			*
+	\*******************************************************/
+	if (st_info_valid[unit]) return(TRUE);
+	/*******************************************************\
+	* First do a mode sense 				*
+	\*******************************************************/
+	bzero(&scsi_cmd, sizeof(scsi_cmd));
+	scsi_cmd.op_code = MODE_SENSE;
+	scsi_cmd.length = sizeof(scsi_sense);
+	/*******************************************************\
+	* do the command, but we don't need the results		*
+	* just print them for our interest's sake		*
+	\*******************************************************/
+	if (st_scsi_cmd(unit,
+			&scsi_cmd,
+			sizeof(scsi_cmd),
+			&scsi_sense,
+			sizeof(scsi_sense),
+			5000,
+			flags | SCSI_DATA_IN) != 0)
+	{
+		if(!(flags & SCSI_SILENT))
+			printf("could not mode sense for unit %d\n", unit);
+		st_info_valid[unit] = FALSE;
+		return(FALSE);
+	} 
+	if (st_debug)
+	{
+		printf("unit %d: %d blocks of %d bytes, write %s, %sbuffered",
+			unit,
+			_3btol(&scsi_sense.blk_desc.nblocks),
+			_3btol(&scsi_sense.blk_desc.blklen),
+			(scsi_sense.header.write_protected ?
+				"protected" : "enabled"),
+			(scsi_sense.header.buf_mode ?
+				"" : "un")
+			);
+	}
+	st->numblks = _3btol(&scsi_sense.blk_desc.nblocks);
+	st->blksiz = _3btol(&scsi_sense.blk_desc.blklen);
+	return(TRUE);
+}
+
+/*******************************************************\
+* Get the scsi driver to send a full inquiry to the	*
+* device and use the results to fill out the global 	*
+* parameter structure.					*
+\*******************************************************/
+st_mode_select(unit, flags, dsty_code)
+int	unit,flags,dsty_code;
+{
+	struct scsi_mode_select scsi_cmd;
+	struct
+	{
+		struct	scsi_mode_header_tape header;
+		struct	blk_desc	blk_desc;
+	}dat;
+	struct	st_data *st = st_data + unit;
+
+	/*******************************************************\
+	* Set up for a mode select				*
+	\*******************************************************/
+	bzero(&dat, sizeof(dat));
+	bzero(&scsi_cmd, sizeof(scsi_cmd));
+	scsi_cmd.op_code = MODE_SELECT;
+	scsi_cmd.length = sizeof(dat);
+	dat.header.blk_desc_len = sizeof(struct  blk_desc);
+	dat.header.buf_mode = 1;
+        dat.blk_desc.density = dsty_code;
+	if(st->flags & ST_FIXEDBLOCKS)
+	{
+		lto3b( st->blkmin , dat.blk_desc.blklen);
+	}
+/*	lto3b( st->numblks , dat.blk_desc.nblocks); use defaults!!!!
+	lto3b( st->blksiz , dat.blk_desc.blklen);
+*/
+	/*******************************************************\
+	* do the command					*
+	\*******************************************************/
+	if (st_scsi_cmd(unit,
+			&scsi_cmd,
+			sizeof(scsi_cmd),
+			&dat,
+			sizeof(dat),
+			5000,
+			flags | SCSI_DATA_OUT) != 0)
+	{
+		if(!(flags & SCSI_SILENT))
+			printf("could not mode select for unit %d\n", unit);
+		st_info_valid[unit] = FALSE;
+		return(FALSE);
+	} 
+	return(TRUE);
+}
+
+/*******************************************************\
+* skip N blocks/filemarks/seq filemarks/eom		*
+\*******************************************************/
+st_space(unit,number,what,flags)
+int	unit,number,what,flags;
+{
+	struct scsi_space scsi_cmd;
+
+	/* if we are at a filemark now, we soon won't be*/
+	st_data[unit].flags &= ~(ST_AT_FILEMARK | ST_AT_EOM);
+	bzero(&scsi_cmd, sizeof(scsi_cmd));
+	scsi_cmd.op_code = SPACE;
+	scsi_cmd.code = what;
+	lto3b(number,scsi_cmd.number);
+	if (st_scsi_cmd(unit,
+			&scsi_cmd,
+			sizeof(scsi_cmd),
+			0,
+			0,
+			600000, /* 10 mins enough? */
+			flags) != 0)
+	{
+		if(!(flags & SCSI_SILENT))
+			printf("could not space st%d\n", unit);
+		st_info_valid[unit] = FALSE;
+		return(FALSE);
+	}
+	return(TRUE);
+}
+/*******************************************************\
+* write N filemarks					*
+\*******************************************************/
+st_write_filemarks(unit,number,flags)
+int	unit,number,flags;
+{
+	struct scsi_write_filemarks scsi_cmd;
+
+	st_data[unit].flags &= ~(ST_AT_FILEMARK);
+	bzero(&scsi_cmd, sizeof(scsi_cmd));
+	scsi_cmd.op_code = WRITE_FILEMARKS;
+	lto3b(number,scsi_cmd.number);
+	if (st_scsi_cmd(unit,
+			&scsi_cmd,
+			sizeof(scsi_cmd),
+			0,
+			0,
+			100000, /* 10 secs.. (may need to repos head )*/
+			flags) != 0)
+	{
+		if(!(flags & SCSI_SILENT))
+			printf("could not write_filemarks st%d\n", unit);
+		st_info_valid[unit] = FALSE;
+		return(FALSE);
+	}
+	return(TRUE);
+}
+/*******************************************************\
+* load /unload (with retension if true)			*
+\*******************************************************/
+st_load(unit,type,flags)
+int	unit,type,flags;
+{
+	struct  scsi_load  scsi_cmd;
+
+	st_data[unit].flags &= ~(ST_AT_FILEMARK | ST_AT_EOM);
+	bzero(&scsi_cmd, sizeof(scsi_cmd));
+	scsi_cmd.op_code = LOAD_UNLOAD;
+	scsi_cmd.load=type;
+	if (type == LD_LOAD)
+	{
+		/*scsi_cmd.reten=TRUE;*/
+		scsi_cmd.reten=FALSE;
+	}
+	else
+	{
+		scsi_cmd.reten=FALSE;
+	}
+	if (st_scsi_cmd(unit,
+			&scsi_cmd,
+			sizeof(scsi_cmd),
+			0,
+			0,
+			30000, /* 30 secs */
+			flags) != 0)
+	{
+		if(!(flags & SCSI_SILENT))
+			printf("cannot load/unload  st%d\n", unit);
+		st_info_valid[unit] = FALSE;
+		return(FALSE);
+	}
+	return(TRUE);
+}
+/*******************************************************\
+* Prevent or allow the user to remove the tape		*
+\*******************************************************/
+st_prevent(unit,type,flags)
+int	unit,type,flags;
+{
+	struct	scsi_prevent	scsi_cmd;
+
+	bzero(&scsi_cmd, sizeof(scsi_cmd));
+	scsi_cmd.op_code = PREVENT_ALLOW;
+	scsi_cmd.prevent=type;
+	if (st_scsi_cmd(unit,
+			&scsi_cmd,
+			sizeof(scsi_cmd),
+			0,
+			0,
+			5000,
+			flags) != 0)
+	{
+		if(!(flags & SCSI_SILENT))
+			printf("cannot prevent/allow on st%d\n", unit);
+		st_info_valid[unit] = FALSE;
+		return(FALSE);
+	}
+	return(TRUE);
+}
+/*******************************************************\
+*  Rewind the device					*
+\*******************************************************/
+st_rewind(unit,immed,flags)
+int	unit,immed,flags;
+{
+	struct	scsi_rewind	scsi_cmd;
+
+	st_data[unit].flags &= ~(ST_AT_FILEMARK | ST_AT_EOM);
+	bzero(&scsi_cmd, sizeof(scsi_cmd));
+	scsi_cmd.op_code = REWIND;
+	scsi_cmd.immed=immed;
+	if (st_scsi_cmd(unit,
+			&scsi_cmd,
+			sizeof(scsi_cmd),
+			0,
+			0,
+			immed?5000:300000, /* 5 sec or 5 min */
+			flags) != 0)
+	{
+		if(!(flags & SCSI_SILENT))
+			printf("could not rewind st%d\n", unit);
+		st_info_valid[unit] = FALSE;
+		return(FALSE);
+	}
+	return(TRUE);
+}
+/*******************************************************\
+* ask the scsi driver to perform a command for us.	*
+* Call it through the switch table, and tell it which	*
+* sub-unit we want, and what target and lu we wish to	*
+* talk to. Also tell it where to find the command	*
+* how long int is.					*
+* Also tell it where to read/write the data, and how	*
+* long the data is supposed to be			*
+\*******************************************************/
+int	st_scsi_cmd(unit,scsi_cmd,cmdlen,data_addr,datalen,timeout,flags)
+
+int	unit,flags;
+struct	scsi_generic *scsi_cmd;
+int	cmdlen;
+int	timeout;
+u_char	*data_addr;
+int	datalen;
+{
+	struct	scsi_xfer *xs;
+	int	retval;
+	int	s;
+	struct	st_data *st = st_data + unit;
+
+	if(scsi_debug & PRINTROUTINES) printf("\nst_scsi_cmd%d ",unit);
+	if(st->sc_sw)	/* If we have a scsi driver */
+	{
+
+		xs = &(st_scsi_xfer[unit]);
+		if(!(flags & SCSI_NOMASK))
+			s = splbio();
+		st_xfer_block_wait[unit]++;	/* there is someone waiting */
+		while (xs->flags & INUSE)
+		{
+			sleep(&st_xfer_block_wait[unit],PRIBIO+1);
+		}
+		st_xfer_block_wait[unit]--;
+		xs->flags = INUSE;
+		if(!(flags & SCSI_NOMASK))
+			splx(s);
+
+		/*******************************************************\
+		* Fill out the scsi_xfer structure			*
+		\*******************************************************/
+		xs->flags	|=	flags;
+		xs->adapter	=	st->ctlr;
+		xs->targ	=	st->targ;
+		xs->lu		=	st->lu;
+		xs->retries	=	ST_RETRIES;
+		xs->timeout	=	timeout;
+		xs->cmd		=	scsi_cmd;
+		xs->cmdlen	=	cmdlen;
+		xs->data	=	data_addr;
+		xs->datalen	=	datalen;
+		xs->resid	=	datalen;
+		xs->when_done	=	(flags & SCSI_NOMASK)
+					?(int (*)())0
+					:st_done;
+		xs->done_arg	=	unit;
+		xs->done_arg2	=	(int)xs;
+retry:		xs->error	=	XS_NOERROR;
+		xs->bp		=	0;
+		retval = (*(st->sc_sw->scsi_cmd))(xs);
+		switch(retval)
+		{
+		case	SUCCESSFULLY_QUEUED:
+			s = splbio();
+			while(!(xs->flags & ITSDONE))
+				sleep(xs,PRIBIO+1);
+			splx(s);
+
+		case	HAD_ERROR:
+		case	COMPLETE:
+			switch(xs->error)
+			{
+			case	XS_NOERROR:
+				retval = ESUCCESS;
+				break;
+			case	XS_SENSE:
+				retval = (st_interpret_sense(unit,xs));
+				/* only useful for reads */
+				if (retval)
+				{ /* error... don't care about filemarks */
+					st->flags &= ~(ST_AT_FILEMARK
+							| ST_AT_EOM);
+				}
+				else
+				{
+					xs->error = XS_NOERROR;
+					retval = ESUCCESS;
+				}
+				break;
+			case	XS_DRIVER_STUFFUP:
+				retval = EIO;
+				break;
+			case    XS_TIMEOUT:
+				if(xs->retries-- )
+				{
+					xs->flags &= ~ITSDONE;
+					goto retry;
+				}
+				retval = EIO;
+				break;
+			case    XS_BUSY:
+				if(xs->retries-- )
+				{
+					xs->flags &= ~ITSDONE;
+					goto retry;
+				}
+				retval = EIO;
+				break;
+			default:
+				retval = EIO;
+				printf("st%d: unknown error category from scsi driver\n"
+					,unit);
+				break;
+			}	
+			break;
+		case 	TRY_AGAIN_LATER:
+			if(xs->retries-- )
+			{
+				xs->flags &= ~ITSDONE;
+				goto retry;
+			}
+			retval = EIO;
+			break;
+		default:
+			retval = EIO;
+		}
+		xs->flags = 0;	/* it's free! */
+		ststart(unit);
+	}
+	else
+	{
+		printf("st%d: not set up\n",unit);
+		return(EINVAL);
+	}
+	return(retval);
+}
+/***************************************************************\
+* Look at the returned sense and act on the error and detirmine	*
+* The unix error number to pass back... (0 = report no error)	*
+\***************************************************************/
+
+int	st_interpret_sense(unit,xs)
+int	unit;
+struct	scsi_xfer	*xs;
+{
+	struct	scsi_sense_data *sense;
+	int	key;
+	int	silent = xs->flags & SCSI_SILENT;
+
+	/***************************************************************\
+	* If errors are ok, report a success				*
+	\***************************************************************/
+	if(xs->flags & SCSI_ERR_OK) return(ESUCCESS);
+
+	/***************************************************************\
+	* Get the sense fields and work out what CLASS			*
+	\***************************************************************/
+	sense = &(xs->sense);
+	if(st_debug)
+	{
+		int count = 0;
+		printf("code%x class%x valid%x\n"
+				,sense->error_code
+				,sense->error_class
+				,sense->valid);
+		printf("seg%x key%x ili%x eom%x fmark%x\n"
+				,sense->ext.extended.segment
+				,sense->ext.extended.sense_key
+				,sense->ext.extended.ili
+				,sense->ext.extended.eom
+				,sense->ext.extended.filemark);
+		printf("info: %x %x %x %x followed by %d extra bytes\n"
+				,sense->ext.extended.info[0]
+				,sense->ext.extended.info[1]
+				,sense->ext.extended.info[2]
+				,sense->ext.extended.info[3]
+				,sense->ext.extended.extra_len);
+		printf("extra: ");
+		while(count < sense->ext.extended.extra_len)
+		{
+			printf ("%x ",sense->ext.extended.extra_bytes[count++]);
+		}
+		printf("\n");
+	}
+	switch(sense->error_class)
+	{
+	/***************************************************************\
+	* If it's class 7, use the extended stuff and interpret the key	*
+	\***************************************************************/
+	case 7:
+	{
+		if(sense->ext.extended.eom)
+		{
+			st_data[unit].flags |= ST_AT_EOM;
+		}
+
+		if(sense->ext.extended.filemark)
+		{
+			st_data[unit].flags |= ST_AT_FILEMARK;
+		}
+
+		if(sense->ext.extended.ili)
+		{
+			if(sense->valid)
+			{
+				/*******************************\
+				* In all ili cases, note that	*
+				* the resid is non-0 AND not 	*
+				* unchanged.			*
+				\*******************************/
+				xs->resid
+				   = ntohl(*((long *)sense->ext.extended.info));
+				if(xs->bp)
+				{
+					if(xs->resid < 0)
+					{ /* never on block devices */
+						/***********************\
+						* it's only really bad	*
+						* if we have lost data	*
+						* (the record was 	*
+						* bigger than the read)	*
+						\***********************/
+						return(EIO);
+					}
+				}	
+			}
+			else
+			{ /* makes no sense.. complain */
+				printf("BAD length error?");
+			}
+		}/* there may be some other error. check the rest */
+
+		key=sense->ext.extended.sense_key;
+		switch(key)
+		{
+		case	0x0:
+			return(ESUCCESS);
+		case	0x1:
+			if(!silent)
+			{
+				printf("st%d: soft error(corrected) ", unit); 
+				if(sense->valid)
+				{
+			   		printf("block no. %d (decimal)\n",
+			  		(sense->ext.extended.info[0] <<24)|
+			  		(sense->ext.extended.info[1] <<16)|
+			  		(sense->ext.extended.info[2] <<8)|
+			  		(sense->ext.extended.info[3] ));
+				}
+			 	else
+				{
+			 		printf("\n");
+				}
+			}
+			return(ESUCCESS);
+		case	0x2:
+			if(!silent) printf("st%d: not ready\n ", unit); 
+			return(ENODEV);
+		case	0x3:
+			if(!silent)
+			{
+				printf("st%d: medium error ", unit); 
+				if(sense->valid)
+				{
+			   		printf("block no. %d (decimal)\n",
+			  		(sense->ext.extended.info[0] <<24)|
+			  		(sense->ext.extended.info[1] <<16)|
+			  		(sense->ext.extended.info[2] <<8)|
+			  		(sense->ext.extended.info[3] ));
+				}
+			 	else
+				{
+			 		printf("\n");
+				}
+			}
+			return(EIO);
+		case	0x4:
+			if(!silent) printf("st%d: non-media hardware failure\n ",
+				unit); 
+			return(EIO);
+		case	0x5:
+			if(!silent) printf("st%d: illegal request\n ", unit); 
+			return(EINVAL);
+		case	0x6:
+			if(!silent) printf("st%d: Unit attention.\n ", unit); 
+			st_data[unit].flags &= ~(ST_AT_FILEMARK|ST_AT_EOM);
+			st_info_valid[unit] = FALSE;
+			if (st_data[unit].flags & ST_OPEN) /* TEMP!!!! */
+				return(EIO);
+			else
+				return(ESUCCESS);
+		case	0x7:
+			if(!silent)
+			{
+				printf("st%d: attempted protection violation "
+								, unit); 
+				if(sense->valid)
+				{
+			   		printf("block no. %d (decimal)\n",
+			  		(sense->ext.extended.info[0] <<24)|
+			  		(sense->ext.extended.info[1] <<16)|
+			  		(sense->ext.extended.info[2] <<8)|
+			  		(sense->ext.extended.info[3] ));
+				}
+			 	else
+				{
+			 		printf("\n");
+				}
+			}
+			return(EACCES);
+		case	0x8:
+			if(!silent)
+			{
+				printf("st%d: block wrong state (worm)\n "
+							, unit); 
+				if(sense->valid)
+				{
+			   		printf("block no. %d (decimal)\n",
+			  		(sense->ext.extended.info[0] <<24)|
+			  		(sense->ext.extended.info[1] <<16)|
+			  		(sense->ext.extended.info[2] <<8)|
+			  		(sense->ext.extended.info[3] ));
+				}
+			 	else
+				{
+			 		printf("\n");
+				}
+			}
+			return(EIO);
+		case	0x9:
+			if(!silent) printf("st%d: vendor unique\n",
+				unit); 
+			return(EIO);
+		case	0xa:
+			if(!silent) printf("st%d: copy aborted\n ",
+				unit); 
+			return(EIO);
+		case	0xb:
+			if(!silent) printf("st%d: command aborted\n ",
+				unit); 
+			return(EIO);
+		case	0xc:
+			if(!silent)
+			{
+				printf("st%d: search returned\n ", unit); 
+				if(sense->valid)
+				{
+			   		printf("block no. %d (decimal)\n",
+			  		(sense->ext.extended.info[0] <<24)|
+			  		(sense->ext.extended.info[1] <<16)|
+			  		(sense->ext.extended.info[2] <<8)|
+			  		(sense->ext.extended.info[3] ));
+				}
+			 	else
+				{
+			 		printf("\n");
+				}
+			}
+			return(ESUCCESS);
+		case	0xd:
+			if(!silent) printf("st%d: volume overflow\n ",
+				unit); 
+			return(ENOSPC);
+		case	0xe:
+			if(!silent)
+			{
+			 	printf("st%d: verify miscompare\n ", unit); 
+				if(sense->valid)
+				{
+			   		printf("block no. %d (decimal)\n",
+			  		(sense->ext.extended.info[0] <<24)|
+			  		(sense->ext.extended.info[1] <<16)|
+			  		(sense->ext.extended.info[2] <<8)|
+			  		(sense->ext.extended.info[3] ));
+				}
+			 	else
+				{
+			 		printf("\n");
+				}
+			}
+			return(EIO);
+		case	0xf:
+			if(!silent) printf("st%d: unknown error key\n ",
+				unit); 
+			return(EIO);
+		}
+		break;
+	}
+	/***************************************************************\
+	* If it's NOT class 7, just report it.				*
+	\***************************************************************/
+	case 0:
+	case 1:
+	case 2:
+	case 3:
+	case 4:
+	case 5:
+	case 6:
+		{
+			if(!silent) printf("st%d: error class %d code %d\n",
+				unit,
+				sense->error_class,
+				sense->error_code);
+		if(sense->valid)
+			if(!silent) printf("block no. %d (decimal)\n",
+			(sense->ext.unextended.blockhi <<16),
+			+ (sense->ext.unextended.blockmed <<8),
+			+ (sense->ext.unextended.blocklow ));
+		}
+		return(EIO);
+	}
+}
+
+#if defined(OSF)
+
+stsize(dev_t dev)
+{
+    printf("stsize()        -- not implemented\n");
+    return(0);
+}
+
+stdump()
+{
+    printf("stdump()        -- not implemented\n");
+    return(-1);
+}
+
+#endif /* defined(OSF) */
+