vd.c

早期freebsd实现

		bp->b_error = ENXIO;
		goto bad;
	}
	vi = vddinfo[unit];
	lp = &dklabel[unit];
	if (vi == 0 || vi->ui_alive == 0) {
		bp->b_error = ENXIO;
		goto bad;
	}
	dk = &dksoftc[unit];
	if (dk->dk_state < OPEN) {
		if (dk->dk_state == CLOSED) {
			bp->b_error = EIO;
			goto bad;
		}
		goto q;
	}
	if (dk->dk_state != OPEN && (bp->b_flags & B_READ) == 0) {
		bp->b_error = EROFS;
		goto bad;
	}
	part = vdpart(bp->b_dev);
	if ((dk->dk_openpart & (1 << part)) == 0) {
		bp->b_error = ENODEV;
		goto bad;
	}
	sz = (bp->b_bcount + lp->d_secsize - 1) / lp->d_secsize;
	maxsz = lp->d_partitions[part].p_size;
#ifndef SECSIZE
	sn = bp->b_blkno << dk->dk_bshift;
#else SECSIZE
	sn = bp->b_blkno;
#endif SECSIZE
	if (sn + lp->d_partitions[part].p_offset <= LABELSECTOR &&
#if LABELSECTOR != 0
	    sn + lp->d_partitions[part].p_offset + sz > LABELSECTOR &&
#endif
	    (bp->b_flags & B_READ) == 0 && dk->dk_wlabel == 0) {
		bp->b_error = EROFS;
		goto bad;
	}
	if (sn < 0 || sn + sz > maxsz) {
		if (sn == maxsz) {
			bp->b_resid = bp->b_bcount;
			goto done;
		}
		sz = maxsz - sn;
		if (sz <= 0) {
			bp->b_error = EINVAL;
			goto bad;
		}
		bp->b_bcount = sz * lp->d_secsize;
	}
	bp->b_cylin = (sn + lp->d_partitions[part].p_offset) / lp->d_secpercyl;
#ifdef SECSIZE
if (bp->b_blksize != lp->d_secsize && (bp->b_flags & B_PGIN) == 0)
panic("vdstrat blksize");
#endif SECSIZE
q:
	s = spl7();
	dp = &dkutab[vi->ui_unit];
	disksort(dp, bp);
	if (!dp->b_active) {
		(void) vdustart(vi);
		if (!vi->ui_mi->um_tab.b_active)
			vdstart(vi->ui_mi);
	}
	splx(s);
	return;
bad:	
	bp->b_flags |= B_ERROR;
done:
	biodone(bp);
	return;
}

vdustart(vi)
	register struct vba_device *vi;
{
	register struct buf *bp, *dp;
	register struct vba_ctlr *vm;
	register int unit = vi->ui_unit;
	register struct dksoftc *dk;
	register struct vdsoftc *vd;
	struct disklabel *lp;

	dp = &dkutab[unit];
	/*
	 * If queue empty, nothing to do.
	 */
	if ((bp = dp->b_actf) == NULL)
		return;
	/*
	 * If drive is off-cylinder and controller supports seeks,
	 * place drive on seek queue for controller.
	 * Otherwise, place on transfer queue.
	 */
	vd = &vdsoftc[vi->ui_ctlr];
	dk = &dksoftc[unit];
	vm = vi->ui_mi;
	if (bp->b_cylin != dk->dk_curcyl && vd->vd_flags&VD_DOSEEKS) {
		lp = &dklabel[unit];
		bp->b_track = (bp->b_blkno % lp->d_secpercyl) / lp->d_nsectors;
		if (vm->um_tab.b_seekf == NULL)
			vm->um_tab.b_seekf = dp;
		else
			vm->um_tab.b_seekl->b_forw = dp;
		vm->um_tab.b_seekl = dp;
	} else {
		if (vm->um_tab.b_actf == NULL)
			vm->um_tab.b_actf = dp;
		else
			vm->um_tab.b_actl->b_forw = dp;
		vm->um_tab.b_actl = dp;
	}
	dp->b_forw = NULL;
	dp->b_active++;
}

/*
 * Start next transfer on a controller.
 * There are two queues of drives, the first on-cylinder
 * and the second off-cylinder from their next transfers.
 * Perform the first transfer for the first drive on the on-cylinder
 * queue, if any, otherwise the first transfer for the first drive
 * on the second queue.  Initiate seeks on remaining drives on the
 * off-cylinder queue, then move them all to the on-cylinder queue.
 */
vdstart(vm)
	register struct vba_ctlr *vm;
{
	register struct buf *bp;
	register struct vba_device *vi;
	register struct vdsoftc *vd;
	register struct dksoftc *dk;
	register struct disklabel *lp;
	register struct dcb **dcbp;
	struct buf *dp;
	int sn, tn;

loop:
	/*
	 * Pull a request off the controller queue.
	 */
	if ((dp = vm->um_tab.b_actf) == NULL &&
	    (dp = vm->um_tab.b_seekf) == NULL)
		return;
	if ((bp = dp->b_actf) == NULL) {
		if (dp == vm->um_tab.b_actf)
			vm->um_tab.b_actf = dp->b_forw;
		else
			vm->um_tab.b_seekf = dp->b_forw;
		goto loop;
	}

	/*
	 * Mark controller busy, and determine
	 * destination of this request.
	 */
	vm->um_tab.b_active++;
	vi = vddinfo[vdunit(bp->b_dev)];
	dk = &dksoftc[vi->ui_unit];
#ifndef SECSIZE
	sn = bp->b_blkno << dk->dk_bshift;
#else SECSIZE
	sn = bp->b_blkno;
#endif SECSIZE
	lp = &dklabel[vi->ui_unit];
	sn %= lp->d_secpercyl;
	tn = sn / lp->d_nsectors;
	sn %= lp->d_nsectors;

	/*
	 * Construct dcb for read/write command.
	 */
	vd = &vdsoftc[vm->um_ctlr];
	vd->vd_dcb.intflg = DCBINT_DONE;
	vd->vd_dcb.devselect = dk->dk_dcb.devselect;
	vd->vd_dcb.operrsta = 0;
	vd->vd_dcb.nxtdcb = (struct dcb *)0;	/* end of chain */
	vd->vd_dcb.trail.rwtrail.disk.cylinder = bp->b_cylin;
	vd->vd_dcb.trail.rwtrail.disk.track = tn;
	vd->vd_dcb.trail.rwtrail.disk.sector = sn;
	dk->dk_curcyl = bp->b_cylin;
	bp->b_track = 0;		/* init overloaded field */
	vd->vd_dcb.trailcnt = sizeof (struct trrw) / sizeof (long);
	if (bp->b_flags & B_FORMAT)
		vd->vd_dcb.opcode = dk->dk_op;
	else if (vd->vd_flags & VD_SCATGATH &&
	    ((int)bp->b_un.b_addr & (sizeof(long) - 1)) == 0)
		vd->vd_dcb.opcode = (bp->b_flags & B_READ)? VDOP_RAS : VDOP_GAW;
	else
		vd->vd_dcb.opcode = (bp->b_flags & B_READ)? VDOP_RD : VDOP_WD;

	switch (vd->vd_dcb.opcode) {
	case VDOP_FSECT:
		vd->vd_dcb.trailcnt = sizeof (struct trfmt) / sizeof (long);
		vd->vd_dcb.trail.fmtrail.nsectors = bp->b_bcount /
		    lp->d_secsize;
		vd->vd_dcb.trail.fmtrail.hdr = *(dskadr *)&dk->dk_althdr;
		vd->vd_dcb.trail.rwtrail.disk.cylinder |= dk->dk_fmtflags;
		goto setupaddr;

	case VDOP_RDRAW:
	case VDOP_RD:
	case VDOP_RHDE:
	case VDOP_WD:
		vd->vd_dcb.trail.rwtrail.wcount = (bp->b_bcount+1) >> 1;
setupaddr:
		vd->vd_dcb.trail.rwtrail.memadr =
			vbasetup(bp, &vd->vd_rbuf, (int)lp->d_secsize);
		break;

	case VDOP_RAS:
	case VDOP_GAW:
		vd->vd_dcb.trailcnt += vd_sgsetup(bp, &vd->vd_rbuf,
		    &vd->vd_dcb.trail.sgtrail);
		break;
	}
	if (vi->ui_dk >= 0) {
		dk_busy |= 1<<vi->ui_dk;
		dk_xfer[vi->ui_dk]++;
		dk_wds[vi->ui_dk] += bp->b_bcount>>6;
	}

	/*
	 * Look for any seeks to be performed on other drives on this
	 * controller.  If overlapped seeks exist, insert seek commands
	 * on the controller's command queue before the transfer.
	 */
	dcbp = &vd->vd_mdcb.mdcb_head;

	if (dp == vm->um_tab.b_seekf)
		dp = dp->b_forw;
	else
		dp = vm->um_tab.b_seekf;
	for (; dp != NULL; dp = dp->b_forw) {
		if ((bp = dp->b_actf) == NULL)
			continue;
		vi = vddinfo[vdunit(bp->b_dev)];
		dk = &dksoftc[vi->ui_unit];
		dk->dk_curcyl = bp->b_cylin;
		if (vi->ui_dk >= 0)
			dk_seek[vi->ui_dk]++;
		dk->dk_dcb.operrsta = 0;
		dk->dk_dcb.trail.sktrail.skaddr.cylinder = bp->b_cylin;
		dk->dk_dcb.trail.sktrail.skaddr.track = bp->b_track;
		*dcbp = (struct dcb *)dk->dk_dcbphys;
		dcbp = &dk->dk_dcb.nxtdcb;
	}
	*dcbp = (struct dcb *)vd->vd_dcbphys;
	if (vm->um_tab.b_actf)
		vm->um_tab.b_actl->b_forw = vm->um_tab.b_seekf;
	else
		vm->um_tab.b_actf = vm->um_tab.b_seekf;
	if (vm->um_tab.b_seekf)
		vm->um_tab.b_actl = vm->um_tab.b_seekl;
	vm->um_tab.b_seekf = 0;

	/*
	 * Initiate operation.
	 */
	vd->vd_mdcb.mdcb_status = 0;
	VDGO(vm->um_addr, vd->vd_mdcbphys, vd->vd_type);
}

/*
 * Wait for controller to finish current operation
 * so that direct controller accesses can be done.
 */
vdlock(ctlr)
{
	register struct vba_ctlr *vm = vdminfo[ctlr];
	register struct vdsoftc *vd = &vdsoftc[ctlr];
	int s;

	s = spl7();
	while (vm->um_tab.b_active || vd->vd_flags & VD_LOCKED) {
		vd->vd_flags |= VD_WAIT;
		sleep((caddr_t)vd, PRIBIO);
	}
	vd->vd_flags |= VD_LOCKED;
	splx(s);
}

/*
 * Continue normal operations after pausing for 
 * munging the controller directly.
 */
vdunlock(ctlr)
{
	register struct vba_ctlr *vm = vdminfo[ctlr];
	register struct vdsoftc *vd = &vdsoftc[ctlr];

	vd->vd_flags &= ~VD_LOCKED;
	if (vd->vd_flags & VD_WAIT) {
		vd->vd_flags &= ~VD_WAIT;
		wakeup((caddr_t)vd);
	} else if (vm->um_tab.b_actf || vm->um_tab.b_seekf)
		vdstart(vm);
}

#define	DONTCARE (DCBS_DSE|DCBS_DSL|DCBS_TOP|DCBS_TOM|DCBS_FAIL|DCBS_DONE)
/*
 * Handle a disk interrupt.
 */
vdintr(ctlr)
	register ctlr;
{
	register struct buf *bp, *dp;
	register struct vba_ctlr *vm = vdminfo[ctlr];
	register struct vba_device *vi;
	register struct vdsoftc *vd = &vdsoftc[ctlr];
	register status;
	int timedout;
	struct dksoftc *dk;

	if (!vm->um_tab.b_active) {
		printf("vd%d: stray interrupt\n", ctlr);
		return;
	}
	/*
	 * Get device and block structures, and a pointer
	 * to the vba_device for the drive.
	 */
	dp = vm->um_tab.b_actf;
	bp = dp->b_actf;
	vi = vddinfo[vdunit(bp->b_dev)];
	dk = &dksoftc[vi->ui_unit];
	if (vi->ui_dk >= 0)
		dk_busy &= ~(1<<vi->ui_dk);
	timedout = (vd->vd_wticks >= VDMAXTIME);
	/*
	 * Check for and process errors on
	 * either the drive or the controller.
	 */
	uncache(&vd->vd_dcb.operrsta);
	status = vd->vd_dcb.operrsta;
	if (bp->b_flags & B_FORMAT) {
		dk->dk_operrsta = status;
		uncache(&vd->vd_dcb.err_code);
		/* ecodecnt gets err_code + err_wcnt from the same longword */
		dk->dk_ecodecnt = *(long *)&vd->vd_dcb.err_code;
		uncache(&vd->vd_dcb.err_trk);
		/* erraddr gets error trk/sec/cyl from the same longword */
		dk->dk_erraddr = *(long *)&vd->vd_dcb.err_trk;
	} else if (status & VDERR_HARD || timedout) {
		if (vd->vd_type == VDTYPE_SMDE)
			uncache(&vd->vd_dcb.err_code);
		if (status & DCBS_WPT) {
			/*
			 * Give up on write locked devices immediately.
			 */
			printf("dk%d: write locked\n", vi->ui_unit);
			bp->b_flags |= B_ERROR;
		} else if (status & VDERR_RETRY || timedout) {
			if (status & VDERR_CTLR || timedout) {
				vdharderr(timedout ?
				    "controller timeout" : "controller err",
				    vd, bp, &vd->vd_dcb);
				printf("; resetting controller...");
				vdreset_ctlr(vm);
			} else if (status & VDERR_DRIVE) {
				vdharderr("drive err", vd, bp, &vd->vd_dcb);
				printf("; resetting drive...");
				if (!vdreset_drive(vi))
					dk->dk_state = CLOSED;
			} else
				vdharderr("data err", vd, bp, &vd->vd_dcb);
			/*
			 * Retry transfer once, unless reset failed.
			 */
			if (!vi->ui_alive || dp->b_errcnt++ >= 1) {
				printf("\n");
				goto hard;
			}

			printf(" retrying\n");
			vm->um_tab.b_active = 0;	/* force retry */
		} else  {
			vdharderr("hard error", vd, bp, &vd->vd_dcb);
			printf("\n");
	hard:
			bp->b_flags |= B_ERROR;
		}
	} else if (status & DCBS_SOFT)
		vdsofterr(bp, &vd->vd_dcb);
if (vd->vd_wticks > 3) {
vd->vd_dcb.err_code = vd->vd_wticks;
vdharderr("slow transfer (ecode is sec.)", vd, bp, &vd->vd_dcb);
printf("\n");
}
	vd->vd_wticks = 0;
	if (vm->um_tab.b_active) {
		vm->um_tab.b_active = 0;
		vm->um_tab.b_actf = dp->b_forw;
		dp->b_active = 0;
		dp->b_errcnt = 0;
		dp->b_actf = bp->av_forw;
		bp->b_resid = 0;
		vbadone(bp, &vd->vd_rbuf);
		biodone(bp);
		/*
		 * If this unit has more work to do,
		 * then start it up right away.
		 */
		if (dp->b_actf)
			vdustart(vi);
		else if (dk->dk_openpart == 0)
			wakeup((caddr_t)dk);
	}
	/*
	 * If there are devices ready to
	 * transfer, start the controller.
	 */
	if (vd->vd_flags & VD_WAIT) {
		vd->vd_flags &= ~VD_WAIT;
		wakeup((caddr_t)vd);
	} else if (vm->um_tab.b_actf || vm->um_tab.b_seekf)
		vdstart(vm);
}

vdharderr(what, vd, bp, dcb)
	char *what;
	struct vdsoftc *vd;
	register struct buf *bp;
	register struct dcb *dcb;
{
	int unit = vdunit(bp->b_dev), status = dcb->operrsta;
	register struct disklabel *lp = &dklabel[unit];
	int blkdone;

	if (vd->vd_wticks < VDMAXTIME)
		status &= ~DONTCARE;
	blkdone = ((((dcb->err_cyl & 0xfff) * lp->d_ntracks + dcb->err_trk) *
	    lp->d_nsectors + dcb->err_sec -
	    lp->d_partitions[vdpart(bp->b_dev)].p_offset) >>
	    dksoftc[unit].dk_bshift) - bp->b_blkno;
	diskerr(bp, "dk", what, LOG_PRINTF, blkdone, lp);
	printf(", status %b", status, VDERRBITS);
	if (vd->vd_type == VDTYPE_SMDE)
		printf(" ecode %x", dcb->err_code);
}

vdsofterr(bp, dcb)
	register struct buf *bp;
	register struct dcb *dcb;
{
	int unit = vdunit(bp->b_dev);
	struct disklabel *lp = &dklabel[unit];
	int status = dcb->operrsta;
	int blkdone;

	blkdone = ((((dcb->err_cyl & 0xfff) * lp->d_ntracks + dcb->err_trk) *
	    lp->d_nsectors + dcb->err_sec -
	    lp->d_partitions[vdpart(bp->b_dev)].p_offset) >>
	    dksoftc[unit].dk_bshift) - bp->b_blkno;

	if (status != (DCBS_CCD|DCBS_SOFT|DCBS_ERR|DCBS_DONE)) {
		diskerr(bp, "dk", "soft error", LOG_WARNING, blkdone, lp);
		addlog(", status %b ecode %x\n", status, VDERRBITS,
		    dcb->err_code);
	} else {
		diskerr(bp, "dk", "soft ecc", LOG_WARNING, blkdone, lp);
		addlog("\n");
	}
}

vdioctl(dev, cmd, data, flag)
	dev_t dev;
	int cmd;
	caddr_t data;
	int flag;
{
	register int unit = vdunit(dev);
	register struct disklabel *lp = &dklabel[unit];
	register struct dksoftc *dk = &dksoftc[unit];
	int error = 0, vdformat();

	switch (cmd) {

	case DIOCGDINFO:
		*(struct disklabel *)data = *lp;
		break;

	case DIOCGPART:
		((struct partinfo *)data)->disklab = lp;
		((struct partinfo *)data)->part =
		    &lp->d_partitions[vdpart(dev)];
		break;

	case DIOCSDINFO:
		if ((flag & FWRITE) == 0)
			error = EBADF;
		else
			error = setdisklabel(lp, (struct disklabel *)data,
			    (dk->dk_state == OPENRAW) ? 0 : dk->dk_openpart);
		if (error == 0 && dk->dk_state == OPENRAW &&
		    vdreset_drive(vddinfo[unit]))
			dk->dk_state = OPEN;
		break;

	case DIOCWLABEL:
		if ((flag & FWRITE) == 0)
			error = EBADF;
		else
			dk->dk_wlabel = *(int *)data;
		break;

	case DIOCWDINFO:
		if ((flag & FWRITE) == 0)
			error = EBADF;
		else if ((error = setdisklabel(lp, (struct disklabel *)data,
		    (dk->dk_state == OPENRAW) ? 0 : dk->dk_openpart)) == 0) {
			int wlab;

			if (error == 0 && dk->dk_state == OPENRAW &&
			    vdreset_drive(vddinfo[unit]))
				dk->dk_state = OPEN;
			/* simulate opening partition 0 so write succeeds */
			dk->dk_openpart |= (1 << 0);		/* XXX */
			wlab = dk->dk_wlabel;
			dk->dk_wlabel = 1;
			error = writedisklabel(dev, vdstrategy, lp);
			dk->dk_openpart = dk->dk_copenpart | dk->dk_bopenpart;
			dk->dk_wlabel = wlab;
		}
		break;

	case DIOCWFORMAT:
	    {