tz.c

早期freebsd实现

				 * end of record.
				 * Fixed length blocks, an error.
				 */
				if (sp->endOfMedia) {
					bp->b_error = ENOSPC;
					bp->b_resid = resid;
					break;
				}
				if (sc->sc_blklen && sp->badBlockLen) {
					tprintf(sc->sc_ctty,
						"tz%d: Incorrect Block Length, expected %d got %d\n",
						unit, sc->sc_blklen, resid);
					break;
				}
				if (resid < 0) {
					/*
					 * Variable length records but
					 * attempted to read less than a
					 * full record.
					 */
					tprintf(sc->sc_ctty,
						"tz%d: Partial Read of Variable Length Tape Block, expected %d read %d\n",
						unit, bp->b_bcount - resid,
						bp->b_bcount);
					bp->b_resid = 0;
					break;
				}
				if (sp->fileMark)
					sc->sc_flags |= TZF_SEENEOF;
				/*
				 * Attempting to read more than a record is
				 * OK. Just record how much was actually read.
				 */
				bp->b_flags &= ~B_ERROR;
				bp->b_error = 0;
				bp->b_resid = resid;
				break;

			case SCSI_CLASS7_UNIT_ATTN:
				if (!(sc->sc_flags & TZF_OPEN))
					break;

			default:
			prerr:
				printf("tz%d: ", unit);
				scsiPrintSense((ScsiClass7Sense *)
					sc->sc_sense.sense,
					sizeof(sc->sc_sense.sense) - resid);
			}
		}
	} else if (error || (status & SCSI_STATUS_CHECKCOND)) {
#ifdef DEBUG
		if (!cold && tzdebug)
			printf("tz%d: error %d scsi status 0x%x\n",
				unit, error, status);
#endif
		/* save error info */
		sc->sc_sense.status = status;
		bp->b_flags |= B_ERROR;
		bp->b_error = error;
		bp->b_resid = resid;

		if (status & SCSI_STATUS_CHECKCOND) {
			/*
			 * Start a REQUEST_SENSE command.
			 * Since we are called at interrupt time, we can't
			 * wait for the command to finish; that's why we use
			 * the sc_flags field.
			 */
			sc->sc_flags |= TZF_SENSEINPROGRESS;
			sc->sc_cdb.len = sizeof(ScsiGroup0Cmd);
			scsiGroup0Cmd(SCSI_REQUEST_SENSE, sc->sc_sd->sd_slave,
				0, sizeof(sc->sc_sense.sense),
				(ScsiGroup0Cmd *)sc->sc_cdb.cdb);
			sc->sc_errbuf.b_flags = B_BUSY | B_PHYS | B_READ;
			sc->sc_errbuf.b_bcount = sizeof(sc->sc_sense.sense);
			sc->sc_errbuf.b_un.b_addr = (caddr_t)sc->sc_sense.sense;
			sc->sc_errbuf.b_actf = bp;
			sc->sc_errbuf.b_actb = bp->b_actb;
			*bp->b_actb = &sc->sc_errbuf;
			bp->b_actb = &sc->sc_errbuf.b_actf;
			tzstart(unit);
			return;
		}
	} else {
		sc->sc_sense.status = status;
		bp->b_resid = resid;
	}

	if (dp = bp->b_actf)
		dp->b_actb = bp->b_actb;
	else
		sc->sc_tab.b_actb = bp->b_actb;
	*bp->b_actb = dp;
	biodone(bp);
	if (sc->sc_tab.b_actf)
		tzstart(unit);
	else {
		sc->sc_tab.b_active = 0;
		if (sc->sc_flags & TZF_WAIT) {
			sc->sc_flags &= ~TZF_WAIT;
			wakeup(&sc->sc_flags);
		}
	}
}

/* ARGSUSED */
tzopen(dev, flags, type, p)
	dev_t dev;
	int flags, type;
	struct proc *p;
{
	register int unit = tzunit(dev);
	register struct tz_softc *sc = &tz_softc[unit];
	int error;

	if (unit >= NTZ || sc->sc_sd == NULL)
		return (ENXIO);
	if (!(sc->sc_flags & TZF_ALIVE)) {
		/* check again, tape may have been turned off at boot time */
		if (!tzprobe(sc->sc_sd))
			return (ENXIO);
	}
	if (sc->sc_flags & TZF_OPEN)
		return (EBUSY);

	/* clear UNIT_ATTENTION */
	error = tzcommand(dev, SCSI_TEST_UNIT_READY, 0, 0, 0);
	while (error) {
		ScsiClass7Sense *sp = (ScsiClass7Sense *)sc->sc_sense.sense;

		/* return error if last error was not UNIT_ATTENTION */
		if (!(sc->sc_sense.status & SCSI_STATUS_CHECKCOND) ||
		    sp->error7 != 0x70 || sp->key != SCSI_CLASS7_UNIT_ATTN)
			return (error);

		/*
		 * Try it again just to be sure and
		 * try to negotiate synchonous transfers.
		 */
		error = tzcommand(dev, SCSI_TEST_UNIT_READY, 0, 0, 0);
	}

	/* get the current mode settings */
	error = tzcommand(dev, SCSI_MODE_SENSE, 0,
		sc->sc_modelen, (caddr_t)&sc->sc_mode);
	if (error)
		return (error);

	/* check for write protected tape */
	if ((flags & FWRITE) && sc->sc_mode.writeprot) {
		uprintf("tz%d: write protected\n", unit);
		return (EACCES);
	}

	/* set record length */
	switch (sc->sc_tapeid) {
	case MT_ISAR:
	case MT_ISHPDAT:
	case MT_ISVIPER1:
		sc->sc_blklen = 512;
		break;

	case MT_ISEXABYTE:
#if 0
		if (minor(dev) & TZ_FIXEDBLK)
			sc->sc_blklen = 1024;
		else
			sc->sc_blklen = st_exblklen;
#endif
		break;

	case MT_ISPYTHON:
	case MT_ISMFOUR:
	case MT_ISTK50:
		sc->sc_blklen = 0;
		break;

	default:
		sc->sc_blklen = (sc->sc_mode.block_size2 << 16) |
			(sc->sc_mode.block_size1 << 8) | sc->sc_mode.block_size0;
	}

	/* save total number of blocks on tape */
	sc->sc_numblks = (sc->sc_mode.blocks_2 << 16) |
		(sc->sc_mode.blocks_1 << 8) | sc->sc_mode.blocks_0;

	/* setup for mode select */
	sc->sc_mode.len = 0;
	sc->sc_mode.media = 0;
	sc->sc_mode.bufferedMode = 1;
	sc->sc_mode.blocks_0 = 0;
	sc->sc_mode.blocks_1 = 0;
	sc->sc_mode.blocks_2 = 0;
	sc->sc_mode.block_size0 = sc->sc_blklen >> 16;
	sc->sc_mode.block_size1 = sc->sc_blklen >> 8;
	sc->sc_mode.block_size2 = sc->sc_blklen;

	/* check for tape density changes */
	switch (sc->sc_tapeid) {
	case MT_ISAR:
		if (minor(dev) & TZ_HIDENSITY)
			sc->sc_mode.density = 0x5;
		else {
			if (flags & FWRITE) {
				uprintf("Can only write QIC-24\n");
				return (EIO);
			}
			sc->sc_mode.density = 0x4;
		}
		break;

	case MT_ISMT02:
		/*
		 * The tape density is set automatically when the tape
		 * is loaded. We only need to change it if we are writing.
		 */
		if (flags & FWRITE) {
			if (minor(dev) & TZ_HIDENSITY)
				sc->sc_mode.density = 0;
			else
				sc->sc_mode.density = 0x4;
		}
		break;

	case MT_ISEXABYTE:
#if 0
		if (minor(dev) & TZ_HIDENSITY)
			uprintf("EXB-8200 density support only\n");
		sc->sc_mode.vupb = (u_char)st_exvup;
		sc->sc_mode.rsvd5 = 0;
		sc->sc_mode.p5 = 0;
		sc->sc_mode.motionthres = (u_char)st_exmotthr;
		sc->sc_mode.reconthres = (u_char)st_exreconthr;
		sc->sc_mode.gapthres = (u_char)st_exgapthr;
#endif
		break;

	case MT_ISHPDAT:
	case MT_ISVIPER1:
	case MT_ISPYTHON:
	case MT_ISTK50:
		if (minor(dev) & TZ_HIDENSITY)
			uprintf("tz%d: Only one density supported\n", unit);
		break;

	case MT_ISMFOUR:
		break;		/* XXX could do density select? */
	}

	/* set the current mode settings */
	error = tzcommand(dev, SCSI_MODE_SELECT, 0,
		sc->sc_modelen, (caddr_t)&sc->sc_mode);
	if (error)
		return (error);

	sc->sc_ctty = tprintf_open(p);
	sc->sc_flags = TZF_ALIVE | TZF_OPEN;
	return (0);
}

tzclose(dev, flag)
	dev_t dev;
	int flag;
{
	register struct tz_softc *sc = &tz_softc[tzunit(dev)];
	int error = 0;

	if (!(sc->sc_flags & TZF_OPEN))
		return (0);
	if (flag == FWRITE ||
	    ((flag & FWRITE) && (sc->sc_flags & TZF_WRITTEN))) {
		error = tzcommand(dev, SCSI_WRITE_EOF, 0, 1, 0);
#if 0
		/*
		 * Cartridge tapes don't do double EOFs on EOT.
		 */
		switch (sc->sc_tapeid) {
		case MT_ISAR:
		case MT_ISMT02:
			break;

		default:
			error = tzcommand(dev, SCSI_WRITE_EOF, 0, 1, 0);
			if (minor(dev) & TZ_NOREWIND)
				(void) tzcommand(dev, SCSI_SPACE, 0, -1, 0);
		}
#endif
	}
	if ((minor(dev) & TZ_NOREWIND) == 0)
		(void) tzcommand(dev, SCSI_REWIND, 0, 0, 0);
	sc->sc_flags &= ~(TZF_OPEN | TZF_WRITTEN);
	tprintf_close(sc->sc_ctty);
	return (error);
}

tzioctl(dev, cmd, data, flag)
	dev_t dev;
	int cmd;
	caddr_t data;
	int flag;
{
	register struct tz_softc *sc = &tz_softc[tzunit(dev)];
	register struct buf *bp = &sc->sc_buf;
	struct mtop *mtop;
	struct mtget *mtget;
	int code, count;
	static tzops[] = {
		SCSI_WRITE_EOF, SCSI_SPACE, SCSI_SPACE, SCSI_SPACE, SCSI_SPACE,
		SCSI_REWIND, SCSI_REWIND, SCSI_TEST_UNIT_READY
	};

	switch (cmd) {

	case MTIOCTOP:	/* tape operation */
		mtop = (struct mtop *)data;
		if ((unsigned)mtop->mt_op < MTREW && mtop->mt_count <= 0)
			return (EINVAL);
		switch (mtop->mt_op) {

		case MTWEOF:
			code = 0;
			count = mtop->mt_count;
			break;

		case MTFSF:
			code = 1;
			count = mtop->mt_count;
			break;

		case MTBSF:
			code = 1;
			count = -mtop->mt_count;
			break;

		case MTFSR:
			code = 0;
			count = mtop->mt_count;
			break;

		case MTBSR:
			code = 0;
			count = -mtop->mt_count;
			break;

		case MTREW:
		case MTOFFL:
		case MTNOP:
			code = 0;
			count = 0;
			break;

		default:
			return (EINVAL);
		}
		return (tzcommand(dev, tzops[mtop->mt_op], code, count, 0));

	case MTIOCGET:
		mtget = (struct mtget *)data;
		mtget->mt_dsreg = 0;
		mtget->mt_erreg = sc->sc_sense.status;
		mtget->mt_resid = 0;
		mtget->mt_type = 0;
		break;

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

void
tzstrategy(bp)
	register struct buf *bp;
{
	register int unit = tzunit(bp->b_dev);
	register struct tz_softc *sc = &tz_softc[unit];
	register struct buf *dp;
	register int s;

	if (sc->sc_flags & TZF_SEENEOF) {
		bp->b_resid = bp->b_bcount;
		biodone(bp);
		return;
	}
	bp->b_actf = NULL;
	dp = &sc->sc_tab;
	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;
		tzstart(unit);
	}
	splx(s);
}
#endif