sd.c

早期freebsd实现

			break;
		}
done:
		bn += btodb(count);
		resid -= count;
		addr += count;
#ifdef DEBUG
		if (sddebug & SDB_PARTIAL)
			printf(" done: bn %x resid %x addr %x\n",
			       bn, resid, addr);
#endif
	}
	free(cbuf, M_DEVBUF);
	free((caddr_t)tbp, M_DEVBUF);
	biodone(bp);
}

/*
 * Start a transfer on sc as described by bp
 * (i.e., call hba or target start).
 * If in format mode, we may not need dma.
 */
#define sdstart(sc, bp) { \
	SD_TRACE(T_START, sc, bp); \
	if ((sc)->sc_format_pid && legal_cmds[(sc)->sc_cmd.cdb_bytes[0]] > 0) \
		(*(sc)->sc_unit.u_start)((sc)->sc_unit.u_updev, \
		    &(sc)->sc_unit.u_forw, (struct buf *)NULL, \
		    sdigo, &(sc)->sc_dk.dk_dev); \
	else \
		(*(sc)->sc_unit.u_start)((sc)->sc_unit.u_updev, \
		    &(sc)->sc_unit.u_forw, bp, sdgo, &(sc)->sc_dk.dk_dev); \
}

void
sdstrategy(bp)
	register struct buf *bp;
{
	register struct sd_softc *sc = sdcd.cd_devs[sdunit(bp->b_dev)];
	register int s;

	if (sc->sc_format_pid) {
		/* XXXXXXXXX SHOULD NOT COMPARE curproc IN HERE!?! */
		/*
		 * In format mode, only allow the owner to mess
		 * with the drive.  Skip all the partition checks.
		 */
		if (sc->sc_format_pid != curproc->p_pid) {
			bp->b_error = EPERM;
			bp->b_flags |= B_ERROR;
			biodone(bp);
			return;
		}
		bp->b_cylin = 0;
	} else {
		register daddr_t bn = bp->b_blkno;
		register int sz = howmany(bp->b_bcount, DEV_BSIZE);
		register struct partition *p;

		/*
		 * Make sure transfer is within partition.
		 * If it starts at the end, return EOF; if
		 * it extends past the end, truncate it.
		 */
		p = &sc->sc_dk.dk_label.d_partitions[sdpart(bp->b_dev)];
		if ((unsigned)bn >= p->p_size) {
			if ((unsigned)bn > p->p_size) {
				bp->b_error = EINVAL;
				bp->b_flags |= B_ERROR;
			} else
				bp->b_resid = bp->b_bcount;
			biodone(bp);
			return;
		}
		if (bn + sz > p->p_size) {
			sz = p->p_size - bn;
			bp->b_bcount = dbtob(sz);
		}
		/*
		 * Non-aligned or partial-block transfers handled specially.
		 * SHOULD THIS BE AT A HIGHER LEVEL?
		 */
		s = sc->sc_blksize - 1;
		if ((dbtob(bn) & s) || (bp->b_bcount & s)) {
			sdlblkstrat(bp, sc->sc_blksize);
			return;
		}
		bp->b_cylin = (bn + p->p_offset) >> sc->sc_bshift;
	}

	/*
	 * Transfer valid, or format mode.  Queue the request
	 * on the drive, and maybe try to start it.
	 */
	s = splbio();
	disksort(&sc->sc_tab, bp);
	if (sc->sc_tab.b_active == 0) {
		sc->sc_tab.b_active = 1;
		sdstart(sc, bp);
	}
	splx(s);
}

int
sderror(sc, stat)
	register struct sd_softc *sc;
	register int stat;
{
	register struct scsi_sense *sn;
	int retry = 0;

	sc->sc_sense.status = stat;
	if ((stat & STS_MASK) == STS_CHECKCOND) {
		sn = (struct scsi_sense *)sc->sc_sense.sense;
		stat = scsi_request_sense(sc->sc_unit.u_hba,
		    sc->sc_unit.u_targ, sc->sc_unit.u_unit,
		    (caddr_t)sn, sizeof sc->sc_sense.sense);
		sc->sc_sense.status = stat;	/* ??? */
		if ((stat & STS_MASK) != STS_GOOD) {
			printf("%s: sense failed, status %x\n",
			    sc->sc_dk.dk_dev.dv_xname, stat);
			return (0);
		}
		printf("%s: scsi sense class %d, code %d",
		    sc->sc_dk.dk_dev.dv_xname,
		    SENSE_ECLASS(sn), SENSE_ECODE(sn));
		if (SENSE_ISXSENSE(sn) && XSENSE_ISSTD(sn)) {
			int key;

			/*
			 * Standard extended sense: can examine sense key
			 * and (if valid) info.
			 */
			key = XSENSE_KEY(sn);
			printf(", key %d", key);
			if (XSENSE_IVALID(sn))
				printf(", blk %d", XSENSE_INFO(sn));
			/* no sense or recovered error, try again */
			if (key == 0 || key == 1)
				retry = 1;
		}
		printf("\n");
	}
	return (retry);
}

/*
 * sdigo is called from the hba driver when it has got the scsi bus
 * for us, and we were doing a format op that did not need dma.
 */
void
sdigo(sc0, cdb)
	struct device *sc0;
	struct scsi_cdb *cdb;
{
	register struct sd_softc *sc = (struct sd_softc *)sc0;
	register struct buf *bp = sc->sc_tab.b_actf;
	register int stat;

	stat = (*sc->sc_unit.u_hbd->hd_icmd)(sc->sc_unit.u_hba,
	    sc->sc_unit.u_targ, &sc->sc_cmd, bp->b_un.b_addr, bp->b_bcount,
	    bp->b_flags & B_READ);
	sc->sc_sense.status = stat;
	if (stat & 0xfe) {		/* XXX */
		(void) sderror(sc, stat);
		bp->b_flags |= B_ERROR;
		bp->b_error = EIO;
	}
	/*
	 * Done with SCSI bus, before we `ought' to be.  Release it.
	 */
	(*sc->sc_unit.u_rel)(sc->sc_unit.u_updev);
	bp->b_resid = 0;
	sc->sc_tab.b_errcnt = 0;
	sc->sc_tab.b_actf = bp->b_actf;
	biodone(bp);
	if ((bp = sc->sc_tab.b_actf) == NULL)
		sc->sc_tab.b_active = 0;
	else
		sdstart(sc, bp);
}

/*
 * sdgo is called from the hba driver or target code when it has
 * allocated the scsi bus and DMA resources and target datapath for us.
 */
void
sdgo(sc0, cdb)
	struct device *sc0;
	register struct scsi_cdb *cdb;
{
	register struct sd_softc *sc = (struct sd_softc *)sc0;
	register struct buf *bp = sc->sc_tab.b_actf;
	register int n;
	register unsigned int u;

	SD_TRACE(T_MKCDB, sc, bp);
	if (sc->sc_format_pid) {
		*cdb = sc->sc_cmd;
		n = 0;
	} else {
		CDB10(cdb)->cdb_cmd = bp->b_flags & B_READ ? CMD_READ10 :
		    CMD_WRITE10;
		CDB10(cdb)->cdb_lun_rel = sc->sc_unit.u_unit << 5;
		u = bp->b_cylin;
		CDB10(cdb)->cdb_lbah = u >> 24;
		CDB10(cdb)->cdb_lbahm = u >> 16;
		CDB10(cdb)->cdb_lbalm = u >> 8;
		CDB10(cdb)->cdb_lbal = u;
		CDB10(cdb)->cdb_xxx = 0;
		n = sc->sc_blksize - 1;
		u = (bp->b_bcount + n) >> (DEV_BSHIFT + sc->sc_bshift);
		CDB10(cdb)->cdb_lenh = u >> 8;
		CDB10(cdb)->cdb_lenl = u;
		CDB10(cdb)->cdb_ctrl = 0;
		n = (bp->b_bcount & n) != 0;
#ifdef DEBUG
		if (n)
			printf("%s: partial block xfer -- %x bytes\n",
			    sc->sc_dk.dk_dev.dv_xname, bp->b_bcount);
#endif
		sc->sc_transfers++;
	}
	if ((*sc->sc_unit.u_go)(sc->sc_unit.u_updev, sc->sc_unit.u_targ,
	    sdintr, (void *)sc, bp, n) == 0) {
#ifdef notyet
		sc->sc_dk.dk_busy = 1;
		sc->sc_dk.dk_seek++;	/* XXX */
		sc->sc_dk.dk_xfer++;
		sc->sc_dk.dk_wds += bp->b_bcount >> 6;
#endif
		return;
	}
	/*
	 * Some sort of nasty unrecoverable error: clobber the
	 * transfer.  Call the bus release function first, though.
	 */
	(*sc->sc_unit.u_rel)(sc->sc_unit.u_updev);
#ifdef DEBUG
	if (sddebug & SDB_ERROR)
		printf("%s: sdgo: %s adr %d blk %d len %d ecnt %d\n",
		    sc->sc_dk.dk_dev.dv_xname,
		    bp->b_flags & B_READ? "read" : "write",
		    bp->b_un.b_addr, bp->b_cylin, bp->b_bcount,
		    sc->sc_tab.b_errcnt);
#endif
	bp->b_flags |= B_ERROR;
	bp->b_error = EIO;
	bp->b_resid = 0;
	sc->sc_tab.b_errcnt = 0;
	sc->sc_tab.b_actf = bp->b_actf;
	biodone(bp);
	if ((bp = sc->sc_tab.b_actf) == NULL)
		sc->sc_tab.b_active = 0;
	else
		sdstart(sc, bp);
}

/*
 * A transfer finished (or, someday, disconnected).
 * We are already off the target/hba queues.
 * Restart this one for error recovery, or start the next, as appropriate.
 */
void
sdintr(sc0, stat, resid)
	struct device *sc0;
	int stat, resid;
{
	register struct sd_softc *sc = (struct sd_softc *)sc0;
	register struct buf *bp = sc->sc_tab.b_actf;
	int retry;

	if (bp == NULL)
		panic("sdintr");
	SD_TRACE(T_INTR, sc, bp);
#ifdef notyet
	sc->sc_dk.dk_busy = 0;
#endif
	if ((stat & STS_MASK) != STS_GOOD) {
#ifdef DEBUG
		if (sddebug & SDB_ERROR)
			printf("%s: sdintr scsi status 0x%x resid %d\n",
			    sc->sc_dk.dk_dev.dv_xname, stat, resid);
#endif
		retry = sderror(sc, stat);
		if (retry && ++sc->sc_tab.b_errcnt <= SDRETRY) {
			printf("%s: retry %d\n",
			    sc->sc_dk.dk_dev.dv_xname, sc->sc_tab.b_errcnt);
			goto restart;
		}
		bp->b_flags |= B_ERROR;
		bp->b_error = EIO;
	}
	bp->b_resid = resid;
	sc->sc_tab.b_errcnt = 0;
	sc->sc_tab.b_actf = bp->b_actf;
	biodone(bp);
	if ((bp = sc->sc_tab.b_actf) == NULL)
		sc->sc_tab.b_active = 0;
	else {
restart:
		sdstart(sc, bp);
	}
}

int
sdioctl(dev_t dev, int cmd, register caddr_t data, int flag, struct proc *p)
{
	register struct sd_softc *sc = sdcd.cd_devs[sdunit(dev)];
#ifdef COMPAT_SUNOS
	int error;

	error = sun_dkioctl(&sc->sc_dk, cmd, data, sdpart(dev));
	if (error >= 0)
		return (error);
#endif
	switch (cmd) {

	case SDIOCSFORMAT:
		/* take this device into or out of "format" mode */
		if (suser(p->p_ucred, &p->p_acflag))
			return (EPERM);
		if (*(int *)data) {
			if (sc->sc_format_pid)
				return (EPERM);
			sc->sc_format_pid = p->p_pid;
		} else
			sc->sc_format_pid = 0;
		break;

	case SDIOCGFORMAT:
		/* find out who has the device in format mode */
		*(int *)data = sc->sc_format_pid;
		break;

	case SDIOCSCSICOMMAND:
#define cdb ((struct scsi_cdb *)data)
		/*
		 * Save what user gave us as SCSI cdb to use with next
		 * read or write to the char device.  Be sure to replace
		 * the lun field with the actual unit number.
		 */
		if (sc->sc_format_pid != p->p_pid)
			return (EPERM);
		if (legal_cmds[cdb->cdb_bytes[0]] == 0)
			return (EINVAL);
		sc->sc_cmd = *cdb;
		sc->sc_cmd.cdb_bytes[1] =
		    (sc->sc_cmd.cdb_bytes[1] & ~(7 << 5)) |
		    (sc->sc_unit.u_unit << 5);
#undef	cdb
		break;

	case SDIOCSENSE:
		/*
		 * return the SCSI sense data saved after the last
		 * operation that completed with "check condition" status.
		 */
		sc->sc_sense = *(struct scsi_fmt_sense *)data;
		break;

	case DIOCGDINFO:
		*(struct disklabel *)data = sc->sc_dk.dk_label;
		break;

	case DIOCGPART:
		((struct partinfo *)data)->disklab = &sc->sc_dk.dk_label;
		((struct partinfo *)data)->part =
		    &sc->sc_dk.dk_label.d_partitions[sdpart(dev)];
		break;

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

int
sdsize(dev_t dev)
{
	register int unit = sdunit(dev);
	register struct sd_softc *sc;

	if (unit >= sdcd.cd_ndevs || (sc = sdcd.cd_devs[unit]) == NULL ||
	    (sc->sc_flags & SDF_ALIVE) == 0)
		return (-1);
	return (sc->sc_dk.dk_label.d_partitions[sdpart(dev)].p_size);
}

/*
 * Write `len' bytes from address `addr' to drive and partition in `dev',
 * at block blkoff from the beginning of the partition.  The address is
 * either kernel virtual or physical (some machines may never use one or
 * the other, but we need it in the protocol to stay machine-independent).
 */
int
sddump(dev_t dev, daddr_t blkoff, caddr_t addr, int len)
{
	register struct sd_softc *sc;
	register struct partition *p;
	register daddr_t bn, n, nblks;
	register struct hba_softc *hba;
	register int stat, unit;
	struct scsi_cdb cdb;

	/* drive ok? */
	unit = sdunit(dev);
	if (unit >= sdcd.cd_ndevs || (sc = sdcd.cd_devs[unit]) == NULL ||
	    (sc->sc_flags & SDF_ALIVE) == 0)
		return (ENXIO);

	/* blocks in range? */
	p = &sc->sc_dk.dk_label.d_partitions[sdpart(dev)];
	n = (len + sc->sc_blksize - 1) >> DEV_BSHIFT;
	if (blkoff < 0 || blkoff >= p->p_size || blkoff + n > p->p_size)
		return (EINVAL);
	bn = blkoff + p->p_offset;
	bn >>= sc->sc_bshift;

	/* scsi bus idle? */
	hba = sc->sc_unit.u_hba;
	if (hba->hba_head) {
		(*hba->hba_driver->hd_reset)(hba, 0);
		printf("[reset %s] ", sc->sc_dk.dk_dev.dv_xname);
	}

	CDB10(&cdb)->cdb_cmd = CMD_WRITE10;
	CDB10(&cdb)->cdb_lun_rel = sc->sc_unit.u_unit << 5;
	CDB10(&cdb)->cdb_xxx = 0;
	CDB10(&cdb)->cdb_ctrl = 0;

#define	DUMP_MAX	(32 * 1024)	/* no more than 32k per write */
	for (;;) {
		if ((n = len) > DUMP_MAX)
			n = DUMP_MAX;
		CDB10(&cdb)->cdb_lbah = bn >> 24;
		CDB10(&cdb)->cdb_lbahm = bn >> 16;
		CDB10(&cdb)->cdb_lbalm = bn >> 8;
		CDB10(&cdb)->cdb_lbal = bn;
		nblks = n >> (DEV_BSHIFT + sc->sc_bshift);
		CDB10(&cdb)->cdb_lenh = nblks >> 8;
		CDB10(&cdb)->cdb_lenl = nblks;
		stat = hba->hba_driver->hd_dump(hba, sc->sc_unit.u_targ,
		    &cdb, addr, n);
		if ((stat & STS_MASK) != STS_GOOD) {
			printf("%s: scsi write error 0x%x\ndump ",
			    sc->sc_dk.dk_dev.dv_xname, stat);
			return (EIO);
		}
		if ((len -= n) == 0)
			return (0);
		addr += n;
		bn += nblks;
	}
}