tm.c

<B>Digital的Unix操作系统VAX 4.2源码</B>

#ifndef lint
static char *sccsid = "@(#)tm.c	4.1      ULTRIX  7/2/90";
#endif	lint

/************************************************************************
 *									*
 *			Copyright (c) 1984, 1986, 1989 by		*
 *		Digital Equipment Corporation, Maynard, MA		*
 *			All rights reserved.				*
 *									*
 *   This software is furnished under a license and may be used and	*
 *   copied  only  in accordance with the terms of such license and	*
 *   with the  inclusion  of  the  above  copyright  notice.   This	*
 *   software  or  any	other copies thereof may not be provided or	*
 *   otherwise made available to any other person.  No title to and	*
 *   ownership of the software is hereby transferred.			*
 *									*
 *   This software is  derived	from  software	received  from	the	*
 *   University    of	California,   Berkeley,   and	from   Bell	*
 *   Laboratories.  Use, duplication, or disclosure is	subject  to	*
 *   restrictions  under  license  agreements  with  University  of	*
 *   California and with AT&T.						*
 *									*
 *   The information in this software is subject to change  without	*
 *   notice  and should not be construed as a commitment by Digital	*
 *   Equipment Corporation.						*
 *									*
 *   Digital assumes no responsibility for the use  or	reliability	*
 *   of its software on equipment which is not supplied by Digital.	*
 *									*
 ************************************************************************/

/*
 * tm.c    6.3	   09/26/83
 *
 * Modification history
 *
 * TM11/TE10 tape driver
 *
 *  6-Aug-85 - ricky palmer
 *	Derived from 4.2BSD labeled: tm.c	6.3	83/09/26.
 *	Added new ioctl functionality as well as new code to handle
 *	EOT correctly. Driver now supports new minor number convention
 *	to allow for more than 4 tape devices. V2.0
 *
 * 18-Mar-86  -- jaw
 *
 *	br/cvec changed to NOT use registers.
 *
 * 19-Mar-86 - ricky palmer
 *
 *	Added new DEVIOCGET ioctl request code. V2.0
 *
 * 16-Apr-86 - darrell
 *
 *	badaddr is now called via the macro BADADDR.
 *
 * 11-Jul-86 - ricky palmer
 *
 *	Added adpt and nexus fields to DEVIOCGET code.
 *
 * 26-Aug-86 - rsp (Ricky Palmer)
 *
 *	Cleaned up devioctl code to (1) zero out devget structure
 *	upon entry and (2) use strlen instead of fixed storage
 *	for bcopy's.
 *
 * 05-Jun-89 - Tim Burke
 *	Added a new MTIOCTOP called MTFLUSH.  This is used on caching drives
 *	to force a flush of the controller's write back cache.  Since this 
 *	is not a caching drive the MTFLUSH always returns ENXIO.
 */

#include "te.h"
#if NTE > 0 || defined(BINARY)

#include "../data/tm_data.c"

u_short tmstd[] = { TMSTD, 0 };
int	tmprobe(), tmslave(), tmattach(), tmdgo(), tmintr(), tmtimer();

struct	uba_driver tmdriver = { tmprobe, tmslave, tmattach, tmdgo,
				tmstd, "te", tedinfo, "tm",
				tmminfo, 0 };

/*
 * Determine if there is a controller for
 * a tm at address reg.  Our goal is to make the
 * device interrupt.
 */
tmprobe(reg)
	caddr_t reg;
{

#ifdef lint
	tmintr(0);
#endif lint

	((struct tmdevice *)reg)->tmcs = TM_IE;
	/*
	 * If this is a tm11, it ought to have interrupted
	 * by now, if it isn't (ie: it is a ts04) then we just
	 * hope that it didn't interrupt, so autoconf will ignore it.
	 * Just in case, we will reference one
	 * of the more distant registers, and hope for a machine
	 * check, or similar disaster if this is a ts.
	 *
	 * Note: on an 11/780, BADADDR will just generate
	 * a uba error for a ts; but our caller will notice that
	 * so we won't check for it.
	 */
	if (BADADDR((caddr_t)&((struct tmdevice *)reg)->tmrd, 2))
		return (0);
	return (sizeof (struct tmdevice));
}

/*
 * Due to a design flaw, we cannot ascertain if the tape
 * exists or not unless it is on line - ie: unless a tape is
 * mounted. This is too servere a restriction to bear,
 * so all units are assumed to exist.
 */
tmslave(ui, reg)
	struct uba_device *ui;
	caddr_t reg;
{

	if (ui->ui_slave)	/* non-zero slave not allowed */
		return(0);
	return (1);
}

/*
 * Record attachment of the unit to the controller.
 */
tmattach(ui)
	struct uba_device *ui;
{
	register struct te_softc *sc = &te_softc[ui->ui_unit];
	/*
	 * Tetotm is used to index the ctmbuf and rtmbuf
	 * arrays given a te unit number.
	 */
	tetotm[ui->ui_unit] = ui->ui_mi->um_ctlr;
	bcopy(DEV_UNKNOWN,sc->sc_device,strlen(DEV_UNKNOWN));
}

/*
 * Open the device.  Tapes are unique open
 * devices, so we refuse if it is already open.
 * We also check that a tape is available, and
 * don't block waiting here; if you want to wait
 * for a tape you should timeout in user code.
 */
tmopen(dev, flag)
	register dev_t dev;
	register int flag;
{
	register struct uba_device *ui;
	register struct te_softc *sc;
	register struct tmdevice *tmaddr;
	register int sel = SEL(dev);
	int unit = UNIT(dev);
	int s;

	if (unit >= nNTE || (sc = &te_softc[unit])->sc_openf ||
	    (ui = tedinfo[unit]) == 0 || ui->ui_alive == 0) {
		return (ENXIO);
	}

	tmaddr = (struct tmdevice *)ui->ui_addr;
	if ((tmaddr->tmer & TMER_EOT) && (dis_eot_te[unit] != DISEOT)) {
		sc->sc_flags &= DEV_EOM;
	} else {
		sc->sc_flags = 0;
	}
	sc->sc_category_flags = 0;

	sc->sc_dens = (((sel == MTHR) || (sel == MTHN)) ?
			      (TM_IE | TM_GO | (ui->ui_slave << 8)):
			      (TM_IE | TM_GO | (ui->ui_slave << 8) |
			       TM_D800));
	if((sel == MTHR) || (sel == MTHN)) {
		sc->sc_category_flags |= DEV_1600BPI;
	} else {
		sc->sc_category_flags |= DEV_800BPI;
	}
get:
	tmcommand(dev, TM_SENSE, 1);
	if (sc->sc_erreg & TMER_SDWN) {
		sleep((caddr_t)&lbolt, PZERO+1);
		goto get;
	}

	if ((sc->sc_erreg & (TMER_SELR|TMER_TUR)) !=
	    (TMER_SELR|TMER_TUR)) {
		sc->sc_flags |= DEV_OFFLINE;
		if(!(flag & FNDELAY)) {
			DEV_UGH(sc->sc_device,unit,"offline");
			return(EIO);
		}
	}

	if ((flag & FWRITE) && (sc->sc_erreg & TMER_WRL)) {
		sc->sc_flags |= DEV_WRTLCK;
		if(!(flag & FNDELAY)) {
			DEV_UGH(sc->sc_device,unit,"write locked");
			return(EIO);
		}
	}

	sc->sc_openf = 1;
	sc->sc_blkno = (daddr_t)0;
	sc->sc_nxrec = INF;
	s = spl6();
	if (sc->sc_tact == 0) {
		sc->sc_timo = INF;
		sc->sc_tact = 1;
		timeout(tmtimer, (caddr_t)dev, 5*hz);
	}
	splx(s);
	return (0);
}

/*
 * Close tape device.
 *
 * If tape was open for writing or last operation was
 * a write, then write two EOF's and backspace over the last one.
 * Unless this is a non-rewinding special file, rewind the tape.
 * Make the tape available to others.
 */
tmclose(dev, flag)
	register dev_t dev;
	register int flag;
{
	register struct te_softc *sc = &te_softc[UNIT(dev)];
	register int unit = UNIT(dev);
	register int sel = SEL(dev);

	sc->sc_flags &= ~DEV_EOM;

	if (flag == FWRITE || (flag & FWRITE) &&
	    (sc->sc_flags & DEV_WRITTEN)) {
		tmcommand(dev, TM_WEOF, 1);
		sc->sc_flags &= ~DEV_EOM;
		tmcommand(dev, TM_WEOF, 1);
		sc->sc_flags &= ~DEV_EOM;
		tmcommand(dev, TM_SREV, 1);
		sc->sc_flags &= ~DEV_EOM;
	}

	if ((sel == MTLR) || (sel == MTHR)) {
		/*
		 * 0 count means don't hang waiting for rewind complete
		 * rather ctmbuf stays busy until the operation
		 * completes preventing further opens from completing
		 * by preventing a TM_SENSE from completing.
		 */
		tmcommand(dev, TM_REW, 0);
	}

	sc->sc_openf = 0;

	if ((sc->sc_erreg & TMER_EOT) && (dis_eot_te[unit] != DISEOT)) {
		sc->sc_flags |= DEV_EOM;
	}
}

/*
 * Execute a command on the tape drive
 * a specified number of times.
 */
tmcommand(dev, com, count)
	register dev_t dev;
	register int com;
	register int count;
{
	register struct buf *bp = &ctmbuf[TMUNIT(dev)];
	register int s = spl5();

	while (bp->b_flags&B_BUSY) {
		/*
		 * This special check is because B_BUSY never
		 * gets cleared in the non-waiting rewind case.
		 */
		if (bp->b_repcnt == 0 && (bp->b_flags&B_DONE))
			break;
		bp->b_flags |= B_WANTED;
		sleep((caddr_t)bp, PRIBIO);
	}
	bp->b_flags = B_BUSY|B_READ;
	splx(s);
	bp->b_dev = dev;
	bp->b_repcnt = -count;
	bp->b_command = com;
	bp->b_blkno = 0;
	tmstrategy(bp);
	/*
	 * In case of rewind from close, don't wait.
	 * This is the only case where count can be 0.
	 */
	if (count == 0)
		return;

	iowait(bp);

	if (bp->b_flags&B_WANTED)
		wakeup((caddr_t)bp);
	bp->b_flags &= B_ERROR;
}

/*
 * Queue a tape operation.
 */
tmstrategy(bp)
	register struct buf *bp;
{
	register struct uba_ctlr *um;
	register struct te_softc *sc = &te_softc[UNIT(bp->b_dev)];
	register struct buf *dp;
	register int s;
	register int unit = UNIT(bp->b_dev);

	if ((sc->sc_flags & DEV_EOM) && !((sc->sc_flags & DEV_CSE) ||
	    (dis_eot_te[unit] & DISEOT))) {
		bp->b_resid = bp->b_bcount;
		bp->b_error = ENOSPC;
		bp->b_flags |= B_ERROR;
		iodone(bp);
		return;
	}

	sc->sc_category_flags &= ~DEV_TPMARK;

	/*
	 * Put transfer at end of unit queue
	 */
	dp = &teutab[unit];
	bp->av_forw = NULL;
	s = spl5();
	um = tedinfo[unit]->ui_mi;
	if (dp->b_actf == NULL) {
		dp->b_actf = bp;
		/*
		 * Transport not already active...
		 * put at end of controller queue.
		 */
		dp->b_forw = NULL;
		if (um->um_tab.b_actf == NULL)
			um->um_tab.b_actf = dp;
		else
			um->um_tab.b_actl->b_forw = dp;
		um->um_tab.b_actl = dp;
	} else
		dp->b_actl->av_forw = bp;
	dp->b_actl = bp;
	/*
	 * If the controller is not busy, get
	 * it going.
	 */
	if (um->um_tab.b_active == 0)
		tmstart(um);
	splx(s);
}

/*
 * Start activity on a tm controller.
 */
tmstart(um)
	register struct uba_ctlr *um;
{
	register struct tmdevice *addr = (struct tmdevice *)um->um_addr;
	register struct buf *bp, *dp;
	register struct te_softc *sc;
	register struct uba_device *ui;
	int cmd, tmunit, unit;
	daddr_t blkno;

	/*
	 * Look for an idle transport on the controller.
	 */
loop:
	if ((dp = um->um_tab.b_actf) == NULL)
		return;

	if ((bp = dp->b_actf) == NULL) {
		um->um_tab.b_actf = dp->b_forw;
		goto loop;
	}

	tmunit = TMUNIT(bp->b_dev);
	unit = UNIT(bp->b_dev);
	ui = tedinfo[unit];
	sc = &te_softc[unit];
	addr->tmcs = (ui->ui_slave << 8);
	sc->sc_dsreg = addr->tmcs;
	sc->sc_erreg = addr->tmer;
	sc->sc_resid = addr->tmbc;

	if ((sc->sc_flags & DEV_EOM) && !((sc->sc_flags & DEV_CSE) ||
	    (dis_eot_te[unit] & DISEOT))) {
		bp->b_resid = bp->b_bcount;
		bp->b_error = ENOSPC;
		bp->b_flags |= B_ERROR;
		goto next;
	}

	if ((sc->sc_category_flags & DEV_TPMARK) && 
	    (bp->b_flags & B_READ)) {
		bp->b_resid = 0;
		bp->b_error = EIO;
		bp->b_flags |= B_ERROR;
		goto next;
	}

	/*
	 * Default is that last command was NOT a write command;
	 * if we do a write command we will notice this in tmintr().
	 */
	sc->sc_flags &= ~DEV_WRITTEN;

	if (sc->sc_openf < 0 || (addr->tmcs & TM_CUR) == 0) {
		/*
		 * Have had a hard error on a non-raw tape
		 * or the tape unit is now unavailable
		 * (e.g. taken off line).
		 */
		bp->b_flags |= B_ERROR;
		goto next;
	}
	if (bp == &ctmbuf[tmunit]) {
		/*
		 * Execute control operation with the specified count.
		 */
		if (bp->b_command == TM_SENSE)
			goto next;
		/*
		 * Set next state; give 5 minutes to complete
		 * rewind, or 10 seconds per iteration (minimum 60
		 * seconds and max 5 minutes) to complete other ops.
		 */
		if (bp->b_command == TM_REW) {
			um->um_tab.b_active = SREW;
			sc->sc_timo = 5 * 60;
		} else {
			um->um_tab.b_active = SCOM;
			sc->sc_timo =
			    imin(imax(10*(int)-bp->b_repcnt,60),5*60);
		}
		if (bp->b_command == TM_SFORW ||
		    bp->b_command == TM_SREV)
			addr->tmbc = bp->b_repcnt;
		goto dobpcmd;
	}

	if (sc->sc_blkno != bdbtofsb(bp->b_blkno) &&
	    !um->um_tab.b_errcnt)
		sc->sc_blkno = bdbtofsb(bp->b_blkno);

	sc->sc_nxrec = bdbtofsb(bp->b_blkno) + 1;

	/*
	 * If the data transfer command is in the correct place,
	 * set up all the registers except the csr, and give
	 * control over to the UNIBUS adapter routines, to
	 * wait for resources to start the i/o.
	 */
	if ((blkno = sc->sc_blkno) == bdbtofsb(bp->b_blkno)) {
		addr->tmbc = -bp->b_bcount;
		if ((bp->b_flags&B_READ) == 0) {
			if (um->um_tab.b_errcnt)
				cmd = TM_WIRG;
			else
				cmd = TM_WCOM;
		} else
			cmd = TM_RCOM;
		um->um_tab.b_active = SIO;
		um->um_cmd = sc->sc_dens|cmd;
		sc->sc_timo = 60;
		(void) ubago(ui);
		return;
	}

	/*
	 * Tape positioned incorrectly;
	 * set to seek forwards or backwards to the correct spot.
	 * This happens for raw tapes only on error retries.
	 */
	um->um_tab.b_active = SSEEK;
	if (blkno < bdbtofsb(bp->b_blkno)) {
		bp->b_command = TM_SFORW;
		addr->tmbc = blkno - bdbtofsb(bp->b_blkno);
	} else {
		bp->b_command = TM_SREV;
		addr->tmbc = bdbtofsb(bp->b_blkno) - blkno;
	}

	sc->sc_timo = imin(imax(10 * -addr->tmbc, 60), 5 * 60);

dobpcmd:
	/*
	 * Do the command in bp.
	 */
	addr->tmcs = (sc->sc_dens | bp->b_command);
	return;

next:
	/*
	 * Done with this operation due to error or
	 * the fact that it doesn't do anything.
	 * Release UBA resources (if any), dequeue