hd.c

早期freebsd实现

	register int unit;
	daddr_t sn, sz, maxsz;
	int part, s;

	vi = hddinfo[unit = hdunit(bp->b_dev)];
	if (unit >= NHD || vi == 0 || vi->ui_alive == 0) {
		bp->b_error = ENXIO;
		goto bad;
	}
	dk = &dksoftc[unit];
	if (dk->dk_state < OPEN)
		goto q;
	if (dk->dk_state != OPEN && (bp->b_flags & B_READ) == 0) {
		bp->b_error = EROFS;
		goto bad;
	}
	part = hdpart(bp->b_dev);
	if ((dk->dk_openpart & (1 << part)) == 0) {
		bp->b_error = ENODEV;
		goto bad;
	}
	lp = &dk->dk_label;
	sz = (bp->b_bcount + lp->d_secsize - 1) / lp->d_secsize;
	maxsz = lp->d_partitions[part].p_size;
	sn = bp->b_blkno << dk->dk_bshift;
	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;

q:	s = spl7();
	dp = &dk->dk_utab;
	disksort(dp, bp);
	if (!dp->b_active) {
		(void)hdustart(vi);
		if (!vi->ui_mi->um_tab.b_active)
			hdcstart(vi->ui_mi);
	}
	splx(s);
	return;
bad:
	bp->b_flags |= B_ERROR;
done:
	biodone(bp);
}

hdustart(vi)
	register struct vba_device *vi;
{
	register struct buf *bp, *dp;
	register struct vba_ctlr *vm;
	register struct dksoftc *dk;

	dk = &dksoftc[vi->ui_unit];
	dp = &dk->dk_utab;

	/* if queue empty, nothing to do.  impossible? */
	if (dp->b_actf == NULL)
		return;

	/* place on controller transfer queue */
	vm = vi->ui_mi;
	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++;
}

hdcstart(vm)
	register struct vba_ctlr *vm;
{
	register struct buf *bp;
	register struct dksoftc *dk;
	register struct disklabel *lp;
	register struct master_mcb *master;
	register struct mcb *mcb;
	struct vba_device *vi;
	struct hdcsoftc *hdc;
	struct buf *dp;
	int sn;

	/* pull a request off the controller queue */
	for (;;) {
		if ((dp = vm->um_tab.b_actf) == NULL)
			return;
		if (bp = dp->b_actf)
			break;
		vm->um_tab.b_actf = dp->b_forw;
	}

	/* mark controller active */
	vm->um_tab.b_active++;

	vi = hddinfo[hdunit(bp->b_dev)];
	dk = &dksoftc[vi->ui_unit];
	lp = &dk->dk_label;
	sn = bp->b_blkno << dk->dk_bshift;

	/* fill in mcb */
	mcb = &dk->dk_mcb;
	mcb->forw_phaddr = 0;
	/* mcb->priority = 0; */
	mcb->interrupt = 1;
	mcb->command = (bp->b_flags & B_READ) ? HCMD_READ:HCMD_WRITE;
	mcb->cyl = bp->b_cylin;
/* assumes partition starts on cylinder boundary */
	mcb->head = (sn / lp->d_nsectors) % lp->d_ntracks;
	mcb->sector = sn % lp->d_nsectors;
	mcb->drive = vi->ui_slave;
	/* mcb->context = 0;		/* what do we want on interrupt? */

	hdc = &hdcsoftc[vm->um_ctlr];
	if (!hd_sgsetup(bp, &hdc->hdc_rbuf, mcb->chain)) {
		mcb->chain[0].wcount = (bp->b_bcount+3) >> 2;
		mcb->chain[0].memadr =
		    vbasetup(bp, &hdc->hdc_rbuf, (int)lp->d_secsize);
	}

	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;
	}

	master = &hdc->hdc_mcb;
	master->mcw = MCL_QUEUED;
	master->interrupt = HDCINTERRUPT + vm->um_ctlr;
	master->forw_phaddr = (u_long)vtoph((struct proc *)NULL, mcb);
	hdc->hdc_reg->master_mcb = (u_long)hdc->hdc_mcbp;
}

/*
 * Wait for controller to finish current operation
 * so that direct controller accesses can be done.
 */
hdclock(ctlr)
	int ctlr;
{
	register struct vba_ctlr *vm = hdcminfo[ctlr];
	register struct hdcsoftc *hdc;
	int s;

	hdc = &hdcsoftc[ctlr];
	s = spl7();
	while (vm->um_tab.b_active || hdc->hdc_flags & HDC_LOCKED) {
		hdc->hdc_flags |= HDC_WAIT;
		sleep((caddr_t)hdc, PRIBIO);
	}
	hdc->hdc_flags |= HDC_LOCKED;
	splx(s);
}

/*
 * Continue normal operations after pausing for 
 * munging the controller directly.
 */
hdcunlock(ctlr)
	int ctlr;
{
	register struct vba_ctlr *vm;
	register struct hdcsoftc *hdc = &hdcsoftc[ctlr];

	hdc->hdc_flags &= ~HDC_LOCKED;
	if (hdc->hdc_flags & HDC_WAIT) {
		hdc->hdc_flags &= ~HDC_WAIT;
		wakeup((caddr_t)hdc);
	} else {
		vm = hdcminfo[ctlr];
		if (vm->um_tab.b_actf)
			hdcstart(vm);
	}
}

hdintr(ctlr)
	int ctlr;
{
	register struct buf *bp, *dp;
	register struct vba_ctlr *vm;
	register struct vba_device *vi;
	register struct hdcsoftc *hdc;
	register struct mcb *mcb;
	struct master_mcb *master;
	register int status;
	int timedout;
	struct dksoftc *dk;

	hdc = &hdcsoftc[ctlr];
	master = &hdc->hdc_mcb;
	uncache(&master->mcs);
	uncache(&master->context);

	vm = hdcminfo[ctlr];
	if (!vm->um_tab.b_active || !(master->mcs&MCS_DONE)) {
		printf("hd%d: stray interrupt\n", ctlr);
		return;
	}

	dp = vm->um_tab.b_actf;
	bp = dp->b_actf;
	vi = hddinfo[hdunit(bp->b_dev)];
	dk = &dksoftc[vi->ui_unit];
	if (vi->ui_dk >= 0)
		dk_busy &= ~(1<<vi->ui_dk);
	timedout = (hdc->hdc_wticks >= HDCMAXTIME);

	mcb = &dk->dk_mcb;

	if (master->mcs & (MCS_SOFTERROR | MCS_FATALERROR) || timedout)
		hdcerror(ctlr, *(u_long *)master->xstatus);
	else 
		hdc->hdc_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, &hdc->hdc_rbuf);
		biodone(bp);
		/* start up now, if more work to do */
		if (dp->b_actf)
			hdustart(vi);
		else if (dk->dk_openpart == 0)
			wakeup((caddr_t)dk);
	}
	/* if there are devices ready to transfer, start the controller. */
	if (hdc->hdc_flags & HDC_WAIT) {
		hdc->hdc_flags &= ~HDC_WAIT;
		wakeup((caddr_t)hdc);
	} else if (vm->um_tab.b_actf)
		hdcstart(vm);
}

hdioctl(dev, cmd, data, flag)
	dev_t dev;
	int cmd, flag;
	caddr_t data;
{
	register int unit;
	register struct dksoftc *dk;
	register struct disklabel *lp;
	int error;

	unit = hdunit(dev);
	dk = &dksoftc[unit];
	lp = &dk->dk_label;
	error = 0;
	switch (cmd) {
	case DIOCGDINFO:
		*(struct disklabel *)data = *lp;
		break;
	case DIOCGPART:
		((struct partinfo *)data)->disklab = lp;
		((struct partinfo *)data)->part =
		    &lp->d_partitions[hdpart(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)
			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)
				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, hdstrategy, lp);
			dk->dk_openpart = dk->dk_copenpart | dk->dk_bopenpart;
			dk->dk_wlabel = wlab;
		}
		break;
	default:
		error = ENOTTY;
		break;
	}
	return (error);
}

/*
 * Watch for lost interrupts.
 */
hdcwatch()
{
	register struct hdcsoftc *hdc;
	register struct vba_ctlr **vmp;
	register int ctlr;
	int s;

	timeout(hdcwatch, (caddr_t)0, hz);
	for (vmp = hdcminfo, hdc = hdcsoftc, ctlr = 0; ctlr < NHDC;
	    ++ctlr, ++vmp, ++hdc) {
		if (*vmp == 0 || (*vmp)->um_alive == 0)
			continue;
		s = spl7();
		if ((*vmp)->um_tab.b_active &&
		    hdc->hdc_wticks++ >= HDCMAXTIME) {
			printf("hd%d: lost interrupt\n", ctlr);
			hdintr(ctlr);
		}
		splx(s);
	}
}

hddump(dev)
	dev_t dev;
{
	return(ENXIO);
}

hdsize(dev)
	dev_t dev;
{
	register int unit = hdunit(dev);
	register struct dksoftc *dk;
	struct vba_device *vi;
	struct disklabel *lp;

	if (unit >= NHD || (vi = hddinfo[unit]) == 0 || vi->ui_alive == 0 ||
	    (dk = &dksoftc[unit])->dk_state != OPEN)
		return (-1);
	lp = &dk->dk_label;
	return ((int)lp->d_partitions[hdpart(dev)].p_size >> dk->dk_bshift);
}

hdimcb(dk)
	register struct dksoftc *dk;
{
	register struct master_mcb *master;
	register struct mcb *mcb;
	register struct hdcsoftc *hdc;
	int timeout;

	/* fill in mcb */
	mcb = &dk->dk_mcb;
	mcb->interrupt = 0;
	mcb->forw_phaddr = 0;
	mcb->drive = dk->dk_unit;

	hdc = &hdcsoftc[dk->dk_ctlr];
	master = &hdc->hdc_mcb;

	/* fill in master mcb */
	master->mcw = MCL_IMMEDIATE;
	master->forw_phaddr = (u_long)vtoph((struct proc *)NULL, mcb);
	master->mcs = 0;

	/* kick controller and wait */
	hdc->hdc_reg->master_mcb = (u_long)hdc->hdc_mcbp;
	for (timeout = 15000; timeout; --timeout) {
		DELAY(1000);
		mtpr(PADC, 0);
		if (master->mcs&MCS_FATALERROR) {
			printf("hdc%d: fatal error\n", dk->dk_ctlr);
			hdcerror(dk->dk_ctlr, *(u_long *)master->xstatus);
			return(1);
		}
		if (master->mcs&MCS_DONE)
			return(0);
	}
	printf("hdc%d: timed out\n", dk->dk_ctlr);
	return(1);
}

hdcerror(ctlr, code)
	int ctlr;
	u_long code;
{
	printf("hd%d: error %lx\n", ctlr, code);
}

#ifdef COMPAT_42
hdreadgeometry(dk)
	struct dksoftc *dk;
{
	static geometry_sector geometry;
	register struct mcb *mcb;
	register struct disklabel *lp;
	geometry_block *geo;
	int cnt;

	/*
	 * Read the geometry block (at head = 0 sector = 0 of the drive
	 * definition cylinder), validate it (must have the correct version
	 * number, header, and checksum).
	 */
	mcb = &dk->dk_mcb;
	mcb->command = HCMD_READ;
	mcb->cyl = dk->dk_def_cyl;
	mcb->head = 0;
	mcb->sector = 0;
	mcb->chain[0].wcount = sizeof(geometry_sector) / sizeof(long);
	mcb->chain[0].memadr  = (u_long)vtoph((struct process *)0, &geometry);
	/* mcb->chain[0].memadr = (long)&geometry; */
	if (hdimcb(dk)) {
 		printf("hd%d: can't read default geometry.\n", dk->dk_unit);
		return(1);
	}
	geo = &geometry.geometry_block;
 	if (geo->version > 64000  ||  geo->version < 0) {
 		printf("hd%d: bad default geometry version#.\n", dk->dk_unit);
		return(1);
	}
 	if (bcmp(&geo->id[0], GB_ID, GB_ID_LEN)) {
 		printf("hd%d: bad default geometry header.\n", dk->dk_unit);
		return(1);
	}
	GB_CHECKSUM(geo, cnt);
	if (geometry.checksum != cnt) {
		printf("hd%d: bad default geometry checksum.\n", dk->dk_unit);
		return(1);
	}
	lp = &dk->dk_label;

	/* 1K block in Harris geometry; convert to sectors for disklabels */
	for (cnt = 0; cnt < GB_MAXPART; cnt++) {
		lp->d_partitions[cnt].p_offset =
		    geo->partition[cnt].start * (1024 / lp->d_secsize);
		lp->d_partitions[cnt].p_size =
		    geo->partition[cnt].length * (1024 / lp->d_secsize);
	}
	lp->d_npartitions = GB_MAXPART;
	return(0);
}
#endif /* COMPAT_42 */
#endif /* NHD */