st.c

早期freebsd实现

	msd.blks1 = 0;
	msd.blks0 = 0;
	msd.rsvd4 = 0;
	msd.blklen2 = (sc->sc_blklen >> 16) & 0xff;
	msd.blklen1 = (sc->sc_blklen >> 8) & 0xff;
	msd.blklen0 = sc->sc_blklen & 0xff;

	/*
	 * Do we have any density problems?
	 */

	switch (sc->sc_tapeid) {
	case MT_ISAR:
		if (minor(dev) & STDEV_HIDENSITY)
			msd.density = 0x5;
		else {
			if (flag & FWRITE) {
				uprintf("Can only write QIC-24\n");
				return(EIO);
			}
			msd.density = 0x4;
		}
		break;
	case MT_ISEXABYTE:
		if (minor(dev) & STDEV_HIDENSITY)
			uprintf("EXB-8200 density support only\n");
		msd.vupb = (u_char)st_exvup;
		msd.rsvd5 = 0;
		msd.p5 = 0;
		msd.motionthres = (u_char)st_exmotthr;
		msd.reconthres = (u_char)st_exreconthr;
		msd.gapthres = (u_char)st_exgapthr;
		break;
	case MT_ISHPDAT:
	case MT_ISVIPER1:
	case MT_ISPYTHON:
		if (minor(dev) & STDEV_HIDENSITY)
			uprintf("Only one density supported\n");
		break;
	case MT_ISMFOUR:
		break;		/* XXX could do density select? */
	default:
		uprintf("Unsupported drive\n");
		return(EIO);
	}

	modlen = sc->sc_datalen[CMD_MODE_SELECT];
	modsel.cdb[4] = modlen;

	/* mode select */
	count = 0;
retryselect:
	stat = scsi_immed_command(ctlr, slave, unit, &modsel,
				  (u_char *)&msd, modlen, B_WRITE);
	/*
	 * First command after power cycle, bus reset or tape change 
	 * will error. Try command again
	 */
	if (stat == STS_CHECKCOND) {
		sc->sc_filepos = 0;
		stxsense(ctlr, slave, unit, sc);
		stat = scsi_immed_command(ctlr, slave, unit, &modsel,
					  (u_char *)&msd, modlen, B_WRITE);
#ifdef DEBUG
		if (stat && (st_debug & ST_OPEN))
			printf("stopen: stat on mode select 0x%x second try\n", stat);
#endif
		if (stat == STS_CHECKCOND) {
			stxsense(ctlr, slave, unit, sc);
			prtkey(UNIT(dev), sc);
		}
		if (stat)
			return(EIO);
	}
	if (stat == -1 || stat == STS_BUSY) {
		/*
		 * XXX it might just be that the bus is busy because
		 * another tape is doing a command. This would change
		 * with connect/disconnect, ie. the other drive would
		 * not hold onto the bus.
		 *
		 * Sleep on lbolt for up to 20 minutes (max time to FSF
		 * an exabyte to EOT: 16:xx minutes)
		 */
		if (++count > 60*20) {
			uprintf("SCSI bus timeout\n");
			return(EBUSY);
		}
		if (error = tsleep((caddr_t)&lbolt, PZERO | PCATCH, 
		    "st_scsiwait", 0))
			return (error);
		goto retryselect;
	}

	/* drive ready ? */
	stat = scsi_test_unit_rdy(ctlr, slave, unit);

	if (stat == STS_CHECKCOND) {
		stxsense(ctlr, slave, unit, sc);
		switch (sc->sc_tapeid) {
		case MT_ISEXABYTE:
			if ((xsense->sc_xsense.key & XSK_NOTRDY) &&
			    xsense->exb_xsense.tnp)
				uprintf("no cartridge\n");
			else if (xsense->sc_xsense.key & XSK_NOTRDY)
				uprintf("cartridge not loaded\n");
			else if (xsense->sc_xsense.key & XSK_UNTATTEN) {
				uprintf("new cart/power interrupt\n");
				stat = 0;
			} else if ((xsense->sc_xsense.key & XSK_UNTATTEN) &&
				   xsense->exb_xsense.tnp)
				uprintf("cartridge unloading\n");
			else 
				prtkey(UNIT(dev), sc);
			break;
		case MT_ISMFOUR:
		case MT_ISAR:
			if (xsense->sc_xsense.key & XSK_UNTATTEN)
				stat = scsi_test_unit_rdy(ctlr, slave, unit);
			if (stat == STS_CHECKCOND) {
				stxsense(ctlr, slave, unit, sc);
				if (xsense->sc_xsense.key)
					prtkey(UNIT(dev), sc);
			} else { 
				sc->sc_filepos = 0; /* new tape */
				stat = 0;
			}
			break;
		case MT_ISHPDAT:
		case MT_ISVIPER1:
		case MT_ISPYTHON:
			if (xsense->sc_xsense.key & XSK_UNTATTEN)
				stat = scsi_test_unit_rdy(ctlr, slave, unit);
			if (stat == STS_CHECKCOND) {
				stxsense(ctlr, slave, unit, sc);
				if (xsense->sc_xsense.key)
					prtkey(UNIT(dev), sc);
			}
			break;
		default:
			uprintf("st%d: not ready\n", UNIT(dev));
			prtkey(UNIT(dev), sc);
			break;
		}
	}
	if (stat)
		return(EIO);

	/* mode sense */
	modlen = sc->sc_datalen[CMD_MODE_SENSE];
	modsense.cdb[4] = modlen;
	stat = scsi_immed_command(ctlr, slave, unit, &modsense,
				  (u_char *)&mode, modlen, B_READ);
#ifdef DEBUG
	if (st_debug & ST_OPENSTAT)
		prtmodstat(&mode);
#endif

	if (stat == STS_CHECKCOND) {
		stxsense(ctlr, slave, unit, sc);
#ifdef DEBUG
		if (st_debug & ST_OPEN)
			dumpxsense(xsense);
#endif
	}
	if (stat)
		return(EIO);

	if ((flag & FWRITE) && mode.md.wp) {
		uprintf("st:%d write protected\n", UNIT(dev));
		return(EACCES);
	}

	/* save total number of blocks on tape */
	sc->sc_numblks = mode.md.numblk2 << 16 |
			 mode.md.numblk1 << 8 |
			 mode.md.numblk0;

	if (xsense->sc_xsense.eom && !(sc->sc_flags & STF_LEOT))
		sc->sc_filepos = 0;
#ifdef DEBUG
	if (st_debug & ST_FMKS)
		printf("st%d: open filepos = %d\n", UNIT(dev), sc->sc_filepos);
#endif

	sc->sc_flags |= (STF_OPEN);
	if (flag & FWRITE)
		sc->sc_flags |= STF_WMODE;
	sc->sc_flags &= ~STF_MOVED;

#ifdef TTI
	/* make stats available, also lit up TTi display */
	sc->sc_tticntdwn = 100;
#endif
	stxsense(ctlr, slave, unit, sc);

	return(0);
}

/*ARGSUSED*/
stclose(dev, flag)
	dev_t dev;
	int flag;
{
	register struct st_softc *sc = &st_softc[UNIT(dev)];
	register int hit = 0;

	if ((sc->sc_flags & (STF_WMODE|STF_WRTTN)) == (STF_WMODE|STF_WRTTN)) {
		/*
		 * Cartridge tapes don't do double EOFs on EOT.
		 * We assume that variable-block devices use double EOF.
		 */
		stcommand(dev, MTWEOF, 1); 
		if (sc->sc_blklen == 0) {
			stcommand(dev, MTWEOF, 1); 
			stcommand(dev, MTBSR, 1); 
		}
		hit++;
	}
	if ((minor(dev) & STDEV_NOREWIND) == 0) {
		stcommand(dev, MTREW, 1);
		hit++;
	}
#ifdef NOTDEF
	/* wait until more stable before trying [XXX Needed ?] */
	if (!hit && (sc->sc_flags & SFT_WMODE))
		/* force out any any bufferd write data */
		stcommand(dev, MTFSR, 0); 
#endif
	/* make stats available */
	stxsense(sc->sc_dq.dq_ctlr, sc->sc_dq.dq_slave, sc->sc_punit, sc);

	sc->sc_flags &= ~(STF_OPEN|STF_WMODE|STF_WRTTN);
	tprintf_close(sc->sc_ctty);
	return(0);	/* XXX */
}

ststrategy(bp)
	register struct buf *bp;
{
	struct buf *dp;
	int unit, s;

	unit = UNIT(bp->b_dev);
	dp = &sttab[unit];
	bp->b_actf = NULL;
	s = splbio();
	bp->b_actb = dp->b_actb;
	*dp->b_actb = bp;
	dp->b_actb = &bp->b_actf;
	if (dp->b_active == 0) {
		dp->b_active = 1;
		stustart(unit);
	}
	splx(s);
}

stustart(unit)
	int unit;
{
	if (scsireq(&st_softc[unit].sc_dq))
		ststart(unit);
}

ststart(unit)
	int unit;
{
	struct hp_device *hp = st_softc[unit].sc_hd;

	if (scsiustart(hp->hp_ctlr))
		stgo(unit);
}

stgo(unit)
	int unit;
{
	register struct st_softc *sc = &st_softc[unit];
	register struct scsi_fmt_cdb *cmd;
	register struct buf *bp = sttab[unit].b_actf;
	struct hp_device *hp = sc->sc_hd;
	int pad, stat;
	long nblks;

	if (sc->sc_flags & STF_CMD) {
		cmd = &stcmd[unit];
		pad = 0;
	} else {
		cmd = bp->b_flags & B_READ ? &st_read_cmd : &st_write_cmd;
		if (sc->sc_blklen)
			cmd->cdb[1] |= 0x01; /* fixed mode */
		else
			cmd->cdb[1] &= 0xfe;
		if (bp->b_flags & B_READ)
			sc->sc_flags &= ~STF_WRTTN;
		else
			sc->sc_flags |= STF_WRTTN;

		if (sc->sc_blklen) { /* fixed mode */
			nblks = bp->b_bcount / sc->sc_blklen;
			if (bp->b_bcount % sc->sc_blklen) {
				tprintf(sc->sc_ctty,
					"st%d: I/O not block aligned %d/%ld\n",
					unit, sc->sc_blklen, bp->b_bcount);
				cmd->cdb[1] &= 0xfe; /* force error */
			}
		} else	/* variable len */
			nblks = bp->b_bcount;

		*(u_char *)(&cmd->cdb[2]) = (u_char) (nblks >> 16);
		*(u_char *)(&cmd->cdb[3]) = (u_char) (nblks >> 8);
		*(u_char *)(&cmd->cdb[4]) = (u_char) nblks;
		/*
		 * Always Zero. We are either writing in variable
		 * length mode we are writing in fixed block mode,
		 * or we are going to do odd length IO and are not
		 * going to use DMA.
		 */
		pad = 0; 
	}

#ifdef DEBUG
	if (st_debug & ST_GO)
		printf("stgo: cmd len %d [0]0x%x [1]0x%x [2]0x%x [3]0x%x [4]0x%x [5]0x%x\n",
		       cmd->len, cmd->cdb[0], cmd->cdb[1], cmd->cdb[2],
		       cmd->cdb[3], cmd->cdb[4], cmd->cdb[5]);
#endif

	sc->sc_flags |= STF_MOVED;
	if (bp->b_bcount & 1) {
#ifdef DEBUG
		if (st_debug & ST_ODDIO)
			printf("stgo%d: odd count %d using manual transfer\n",
			       unit, bp->b_bcount);
#endif
		stat = scsi_tt_oddio(hp->hp_ctlr, hp->hp_slave, sc->sc_punit,
				     bp->b_un.b_addr, bp->b_bcount,
				     bp->b_flags, 1);
		if (stat == 0) {
			bp->b_resid = 0;
			stfinish(unit, sc, bp);
		}
	} else
		stat = scsigo(hp->hp_ctlr, hp->hp_slave, sc->sc_punit,
			      bp, cmd, pad);
	if (stat) {
		bp->b_error = EIO;
		bp->b_flags |= B_ERROR;
		stxsense(sc->sc_dq.dq_ctlr, sc->sc_dq.dq_slave, 
			 sc->sc_punit, sc);
		sterror(unit, sc, stat);
		stfinish(unit, sc, bp);
	}
}

stfinish(unit, sc, bp)
	int unit;
	struct st_softc *sc;
	struct buf *bp;
{
	register struct buf *dp;

	sttab[unit].b_errcnt = 0;
	if (dp = bp->b_actf)
		dp->b_actb = bp->b_actb;
	else
		sttab[unit].b_actb = bp->b_actb;
	*bp->b_actb = dp;
	iodone(bp);
	scsifree(&sc->sc_dq);
	if (sttab[unit].b_actf)
		stustart(unit);
	else
		sttab[unit].b_active = 0;
}

stread(dev, uio)
	dev_t dev;
	struct uio *uio;
{
	int unit = UNIT(dev);

	return(physio(ststrategy, &stbuf[unit], dev, B_READ, minphys, uio));
}

stwrite(dev, uio)
	dev_t dev;
	struct uio *uio;
{
	int unit = UNIT(dev);

	return(physio(ststrategy, &stbuf[unit], dev, B_WRITE, minphys, uio));
}

/*ARGSUSED*/
stdump(dev)
	dev_t dev;
{
	return(ENXIO);
}

/*ARGSUSED*/
stioctl(dev, cmd, data, flag)
	dev_t dev;
	int cmd;
	caddr_t data; 
	int flag;
{
	register struct st_softc *sc = &st_softc[UNIT(dev)];
	register int cnt;
	register struct mtget *mtget;
	register struct st_xsense *xp = &st_xsense[UNIT(dev)];
	register struct mtop *op;
	long resid;

	switch (cmd) {

	/* tape operation */
	case MTIOCTOP:
		op = (struct mtop *)data;
		switch (op->mt_op) {

		case MTBSR:
		case MTFSR:
			if (sc->sc_tapeid == MT_ISAR)
				return(ENXIO);
		case MTWEOF:
		case MTFSF:
		case MTBSF:
			cnt = (int)op->mt_count;
			break;

		case MTREW:
		case MTOFFL:
			cnt = 1;
			break;

		case MTNOP:
			return(0);
		default:
			return(EINVAL);
		}
		if (cnt <= 0)
			return(EINVAL);
		stcommand(dev, (u_int)op->mt_op, cnt);
		break;

	/* drive status */
	case MTIOCGET:
		mtget = (struct mtget *)data;
		stxsense(sc->sc_dq.dq_ctlr, sc->sc_dq.dq_slave, 
			 sc->sc_punit, sc);
		mtget->mt_type = sc->sc_tapeid;
		mtget->mt_dsreg = 0;
		mtget->mt_erreg = ((xp->sc_xsense.valid << 15) |
				   (xp->sc_xsense.filemark << 14) |
				   (xp->sc_xsense.eom << 13) |
				   (xp->sc_xsense.ili << 12) |
				   (xp->sc_xsense.key << 8));
		
		if (sc->sc_tapeid == MT_ISEXABYTE) {
			mtget->mt_dsreg = sc->sc_flags;
			resid = (xp->exb_xsense.tplft2 << 16 |
				 xp->exb_xsense.tplft1 << 8 |
				 xp->exb_xsense.tplft0);
			mtget->mt_resid = resid / 1000;
			mtget->mt_erreg |= (((xp->exb_xsense.rwerrcnt2 << 16 |
					      xp->exb_xsense.rwerrcnt1 << 8 |
					      xp->exb_xsense.rwerrcnt0) * 100) / 
					    (sc->sc_numblks - resid)) & 0xff;
		} else if (xp->sc_xsense.valid) {
			resid = ((xp->sc_xsense.info1 << 24) |
				 (xp->sc_xsense.info2 << 16) |
				 (xp->sc_xsense.info3 << 8) |
				 (xp->sc_xsense.info4));
			if (sc->sc_blklen) /* if fixed mode */
				resid *= sc->sc_blklen;
			mtget->mt_resid = resid;
		} else
			mtget->mt_resid = 0;
		break;

	default:
		return(ENXIO);
	}
	return(0);
}