[unix-history] / usr / src / sys / vax / uba / idc.c

/*	idc.c	4.7	82/10/17	*/

#include "rb.h"
#if NIDC > 0
int	idcdebug = 0;
#define	printd if(idcdebug)printf
int	idctrb[1000];
int	*trp = idctrb;
#define	trace(a,b) {*trp++ = (int)a; *trp++ = (int)b; if(trp>&idctrb[998])trp=idctrb;}
/*
 * IDC (RB730) disk driver
 *
 * There can only ever be one IDC on a machine,
 * and only on a VAX-11/730.  We take advantage
 * of that to simplify the driver.
 *
 * TODO:
 *	dk_busy
 *	ecc
 *	dump
 */
#include "../h/param.h"
#include "../h/systm.h"
#include "../h/buf.h"
#include "../h/conf.h"
#include "../h/dir.h"
#include "../h/user.h"
#include "../h/pte.h"
#include "../h/map.h"
#include "../h/vm.h"
#include "../h/dk.h"
#include "../h/cmap.h"
#include "../h/dkbad.h"
#include "../h/uio.h"

#include "../vax/cpu.h"
#include "../vaxuba/ubareg.h"
#include "../vaxuba/ubavar.h"
#include "../vaxuba/idcreg.h"

struct idc_softc {
	int	sc_bcnt;	/* number of bytes to transfer */
	int	sc_resid;	/* total number of bytes to transfer */
	int	sc_ubaddr;	/* Unibus address of data */
	short	sc_unit;	/* unit doing transfer */
	short	sc_softas;	/* software attention summary bits */
	union idc_dar {
		long	dar_l;
		u_short	dar_w[2];
		u_char	dar_b[4];
	} sc_un;		/* prototype disk address register */
} idc_softc;

#define	dar_dar		dar_l		/* the whole disk address */
#define	dar_cyl		dar_w[1]	/* cylinder address */
#define	dar_trk		dar_b[1]	/* track */
#define	dar_sect	dar_b[0]	/* sector */
#define	sc_dar		sc_un.dar_dar
#define	sc_cyl		sc_un.dar_cyl
#define	sc_trk		sc_un.dar_trk
#define	sc_sect		sc_un.dar_sect

/* THIS SHOULD BE READ OFF THE PACK, PER DRIVE */
struct size {
	daddr_t	nblocks;
	int	cyloff;
} rb02_sizes[8] ={
	15884,	0,		/* A=cyl 0 thru 399 */
	4480,	400,		/* B=cyl 400 thru 510 */
	20480,	0,		/* C=cyl 0 thru 511 */
	0,	0,
	0,	0,
	0,	0,
	0,	0,
	0,	0,
}, rb80_sizes[8] ={
	15884,	0,		/* A=cyl 0 thru 36 */
	33440,	37,		/* B=cyl 37 thru 114 */
	242606,	0,		/* C=cyl 0 thru 558 */
	0,	0,
	0,	0,
	0,	0,
	82080,	115,		/* G=cyl 115 thru 304 */
	110143,	305,		/* H=cyl 305 thru 558 */
};
/* END OF STUFF WHICH SHOULD BE READ IN PER DISK */

int	idcprobe(), idcslave(), idcattach(), idcdgo(), idcintr();
struct	uba_ctlr *idcminfo[NIDC];
struct	uba_device *idcdinfo[NRB];

u_short	idcstd[] = { 0174400, 0};
struct	uba_driver idcdriver =
 { idcprobe, idcslave, idcattach, idcdgo, idcstd, "rb", idcdinfo, "idc", idcminfo, 0 };
struct	buf idcutab[NRB];
union	idc_dar idccyl[NRB];

struct	idcst {
	short	nbps;
	short	nsect;
	short	ntrak;
	short	nspc;
	short	ncyl;
	struct	size *sizes;
} idcst[] = {
	256, NRB02SECT, NRB02TRK, NRB02SECT*NRB02TRK, NRB02CYL,	rb02_sizes,
	512, NRB80SECT, NRB80TRK, NRB80SECT*NRB80TRK, NRB80CYL,	rb80_sizes,
};

struct	buf ridcbuf[NRB];

#define	b_cylin	b_resid

#ifdef INTRLVE
daddr_t	dkblock();
#endif

int	idcwstart, idcwticks, idcwatch();

idcprobe(reg)
	caddr_t reg;
{
	register int br, cvec;
	register struct idcdevice *idcaddr;

#ifdef lint	
	br = 0; cvec = br; br = cvec;
#endif
	idcaddr = (struct idcdevice *)((caddr_t)uba_hd[0].uh_uba + 0x200);
	idcaddr->idccsr = IDC_ATTN|IDC_IE;
	while ((idcaddr->idccsr & IDC_CRDY) == 0)
		;
	idcaddr->idccsr = IDC_ATTN|IDC_CRDY;
	return (sizeof (struct idcdevice));
}

idcslave(ui, reg)
	struct uba_device *ui;
	caddr_t reg;
{
	register struct idcdevice *idcaddr;
	register int i;

	idcaddr = (struct idcdevice *)((caddr_t)uba_hd[0].uh_uba + 0x200);
	ui->ui_type = 0;
	idcaddr->idcmpr = IDCGS_GETSTAT;
	idcaddr->idccsr = IDC_GETSTAT|(ui->ui_slave<<8);
	idcwait(idcaddr, 0);
	i = idcaddr->idcmpr;
	idcaddr->idccsr = IDC_CRDY|(1<<(ui->ui_slave+16));
	/* read header to synchronize microcode */
	idcwait(idcaddr, 0);
	idcaddr->idccsr = (ui->ui_slave<<8)|IDC_RHDR;
	idcwait(idcaddr, 0);
	if (idcaddr->idccsr & IDC_ERR)
		return (0);
	i = idcaddr->idcmpr;		/* read header word 1 */
	i = idcaddr->idcmpr;		/* read header word 2 */
	if (idcaddr->idccsr&IDC_R80)
		ui->ui_type = 1;
	return (1);
}

idcattach(ui)
	register struct uba_device *ui;
{

	/*
	 * Fix all addresses to correspond
	 * to the "real" IDC address.
	 */
	ui->ui_mi->um_addr = ui->ui_addr = (caddr_t)uba_hd[0].uh_uba + 0x200;
	ui->ui_physaddr = (caddr_t)uba_hd[0].uh_physuba + 0x200;
	if (idcwstart == 0) {
		timeout(idcwatch, (caddr_t)0, hz);
		idcwstart++;
	}
	if (ui->ui_dk >= 0)
		if (ui->ui_type)
			dk_mspw[ui->ui_dk] = 1.0 / (60 * NRB80SECT * 256);
		else
			dk_mspw[ui->ui_dk] = 1.0 / (60 * NRB02SECT * 128);
	idccyl[ui->ui_unit].dar_dar = -1;
	ui->ui_flags = 0;
}

idcopen(dev)
	dev_t dev;
{
	register int unit = minor(dev) >> 3;
	register struct uba_device *ui;

	if (unit >= NRB || (ui = idcdinfo[unit]) == 0 || ui->ui_alive == 0)
		return (ENXIO);
	return (0);
}
 
idcstrategy(bp)
	register struct buf *bp;
{
	register struct uba_device *ui;
	register struct idcst *st;
	register int unit;
	register struct buf *dp;
	int xunit = minor(bp->b_dev) & 07;
	long bn, sz;

	sz = (bp->b_bcount+511) >> 9;
	unit = dkunit(bp);
	if (unit >= NRB)
		goto bad;
	ui = idcdinfo[unit];
	if (ui == 0 || ui->ui_alive == 0)
		goto bad;
	st = &idcst[ui->ui_type];
	if (bp->b_blkno < 0 ||
	    (bn = dkblock(bp))+sz > st->sizes[xunit].nblocks)
		goto bad;
	if (ui->ui_type == 0)
		bn *= 2;
	bp->b_cylin = bn/st->nspc + st->sizes[xunit].cyloff;
	(void) spl5();
	trace('strt',bp);
	dp = &idcutab[ui->ui_unit];
	disksort(dp, bp);
	if (dp->b_active == 0) {
		trace('!act',dp);
		(void) idcustart(ui);
		bp = &ui->ui_mi->um_tab;
		if (bp->b_actf && bp->b_active == 0)
			(void) idcstart(ui->ui_mi);
	}
	(void) spl0();
	return;

bad:
	bp->b_flags |= B_ERROR;
	iodone(bp);
	return;
}

idcustart(ui)
	register struct uba_device *ui;
{
	register struct buf *bp, *dp;
	register struct uba_ctlr *um;
	register struct idcdevice *idcaddr;
	register struct idcst *st;
	union idc_dar cyltrk;
	daddr_t bn;
	int unit;

	if (ui == 0)
		return (0);
	dk_busy &= ~(1<<ui->ui_dk);
	dp = &idcutab[ui->ui_unit];
	um = ui->ui_mi;
	unit = ui->ui_slave;
	trace('ust', dp);
	idcaddr = (struct idcdevice *)um->um_addr;
	if (um->um_tab.b_active) {
		idc_softc.sc_softas |= 1<<unit;
		trace('umac',idc_softc.sc_softas);
		return (0);
	}
	if ((bp = dp->b_actf) == NULL) {
		trace('!bp',0);
		return (0);
	}
	if (dp->b_active) {
		trace('dpac',dp->b_active);
		goto done;
	}
	dp->b_active = 1;
	/* CHECK DRIVE READY? */
	bn = dkblock(bp);
	trace('seek', bn);
	if (ui->ui_type == 0)
		bn *= 2;
	st = &idcst[ui->ui_type];
	cyltrk.dar_cyl = bp->b_cylin;
	cyltrk.dar_trk = (bn / st->nsect) % st->ntrak;
	cyltrk.dar_sect = 0;
	printd("idcustart, unit %d, cyltrk 0x%x\n", unit, cyltrk.dar_dar);
	/*
	 * If on cylinder, no need to seek.
	 */
	if (cyltrk.dar_dar == idccyl[ui->ui_unit].dar_dar)
		goto done;
	/*
	 * RB80 can change heads (tracks) just by loading
	 * the disk address register, perform optimization
	 * here instead of doing a full seek.
	 */
	if (ui->ui_type && cyltrk.dar_cyl == idccyl[ui->ui_unit].dar_cyl) {
		idcaddr->idccsr = IDC_CRDY|IDC_IE|IDC_SEEK|(unit<<8);
		idcaddr->idcdar = cyltrk.dar_dar;
		idccyl[ui->ui_unit].dar_dar = cyltrk.dar_dar;
		goto done;
	}
	/*
	 * Need to do a full seek.  Select the unit, clear
	 * its attention bit, set the command, load the
	 * disk address register, and then go.
	 */
	idcaddr->idccsr =
	    IDC_CRDY|IDC_IE|IDC_SEEK|(unit<<8)|(1<<(unit+16));
	idcaddr->idcdar = cyltrk.dar_dar;
	idccyl[ui->ui_unit].dar_dar = cyltrk.dar_dar;
	printd("  seek");
	idcaddr->idccsr = IDC_IE|IDC_SEEK|(unit<<8);
	if (ui->ui_dk >= 0) {
		dk_busy |= 1<<ui->ui_dk;
		dk_seek[ui->ui_dk]++;
	}
	/*
	 * RB80's initiate seeks very quickly.  Wait for it
	 * to come ready rather than taking the interrupt.
	 */
	if (ui->ui_type) {
		if (idcwait(idcaddr, 10) == 0)
			return (1);
		idcaddr->idccsr &= ~IDC_ATTN;
		/* has the seek completed? */
		if (idcaddr->idccsr & IDC_DRDY) {
			printd(", drdy");
			idcaddr->idccsr =
			    IDC_CRDY|IDC_IE|IDC_SEEK|(unit<<8)|(1<<(unit+16));
			goto done;
		}
	}
	printd(", idccsr = 0x%x\n", idcaddr->idccsr);
	return (1);
done:
	if (dp->b_active != 2) {
		trace('!=2',dp->b_active);
		dp->b_forw = NULL;
		if (um->um_tab.b_actf == NULL)
			um->um_tab.b_actf = dp;
		else {
			trace('!NUL',um->um_tab.b_actl);
			um->um_tab.b_actl->b_forw = dp;
		}
		um->um_tab.b_actl = dp;
		dp->b_active = 2;
	}
	return (0);
}

idcstart(um)
	register struct uba_ctlr *um;
{
	register struct buf *bp, *dp;
	register struct uba_device *ui;
	register struct idcdevice *idcaddr;
	register struct idc_softc *sc;
	struct idcst *st;
	daddr_t bn;
	int sn, tn, cmd;

loop:
	if ((dp = um->um_tab.b_actf) == NULL) {
		trace('nodp',um);
		return (0);
	}
	if ((bp = dp->b_actf) == NULL) {
		trace('nobp', dp);
		um->um_tab.b_actf = dp->b_forw;
		goto loop;
	}
	um->um_tab.b_active = 1;
	ui = idcdinfo[dkunit(bp)];
	bn = dkblock(bp);
	trace('star',bp);
	if (ui->ui_type == 0)
		bn *= 2;
	sc = &idc_softc;
	st = &idcst[ui->ui_type];
	sn = bn%st->nspc;
	tn = sn/st->nsect;
	sn %= st->nsect;
	sc->sc_sect = sn;
	sc->sc_trk = tn;
	sc->sc_cyl = bp->b_cylin;
	idcaddr = (struct idcdevice *)ui->ui_addr;
	printd("idcstart, unit %d, dar 0x%x", ui->ui_slave, sc->sc_dar);
	if (bp->b_flags & B_READ)
		cmd = IDC_IE|IDC_READ|(ui->ui_slave<<8);
	else
		cmd = IDC_IE|IDC_WRITE|(ui->ui_slave<<8);
	idcaddr->idccsr = IDC_CRDY|cmd;
	if ((idcaddr->idccsr&IDC_DRDY) == 0) {
		printf("rb%d: not ready\n", dkunit(bp));
		um->um_tab.b_active = 0;
		um->um_tab.b_errcnt = 0;
		dp->b_actf = bp->av_forw;
		dp->b_active = 0;
		bp->b_flags |= B_ERROR;
		iodone(bp);
		goto loop;
	}
	idccyl[ui->ui_unit].dar_dar = sc->sc_dar;
	idccyl[ui->ui_unit].dar_sect = 0;
	sn = (st->nsect - sn) * st->nbps;
	if (sn > bp->b_bcount)
		sn = bp->b_bcount;
	sc->sc_bcnt = sn;
	sc->sc_resid = bp->b_bcount;
	sc->sc_unit = ui->ui_slave;
	printd(", bcr 0x%x, cmd 0x%x\n", sn, cmd);
	um->um_cmd = cmd;
	(void) ubago(ui);
	return (1);
}

idcdgo(um)
	register struct uba_ctlr *um;
{
	register struct idcdevice *idcaddr = (struct idcdevice *)um->um_addr;
	register struct idc_softc *sc = &idc_softc;

	/*
	 * VERY IMPORTANT: must load registers in this order.
	 */
	idcaddr->idcbar = sc->sc_ubaddr = um->um_ubinfo&0x3ffff;
	idcaddr->idcbcr = -sc->sc_bcnt;
	idcaddr->idcdar = sc->sc_dar;
	printd("idcdgo, ubinfo 0x%x, cmd 0x%x\n", um->um_ubinfo, um->um_cmd);
	idcaddr->idccsr = um->um_cmd;
	trace('go', um);
	um->um_tab.b_active = 2;
	/*** CLEAR SPURIOUS ATTN ON R80? ***/
}

idcintr(idc)
	int idc;
{
	register struct uba_ctlr *um = idcminfo[idc];
	register struct uba_device *ui;
	register struct idcdevice *idcaddr = (struct idcdevice *)um->um_addr;
	register struct idc_softc *sc = &idc_softc;
	register struct buf *bp, *dp;
	struct idcst *st;
	int unit, as, er, cmd, ds = 0;

	printd("idcintr, idccsr 0x%x", idcaddr->idccsr);
top:
	idcwticks = 0;
	trace('intr', um->um_tab.b_active);
	if (um->um_tab.b_active == 2) {
		/*
		 * Process a data transfer complete interrupt.
		 */
		um->um_tab.b_active = 1;
		dp = um->um_tab.b_actf;
		bp = dp->b_actf;
		ui = idcdinfo[dkunit(bp)];
		unit = ui->ui_slave;
		st = &idcst[ui->ui_type];
		idcaddr->idccsr = IDC_IE|IDC_CRDY|(unit<<8);
		if ((er = idcaddr->idccsr) & IDC_ERR) {
			if (er & IDC_DE) {
				idcaddr->idcmpr = IDCGS_GETSTAT;
				idcaddr->idccsr = IDC_GETSTAT|(unit<<8);
				idcwait(idcaddr, 0);
				ds = idcaddr->idcmpr;
				idcaddr->idccsr =
				    IDC_IE|IDC_CRDY|(1<<(unit+16));
			}
			printd(", er 0x%x, ds 0x%x", er, ds);
			if (ds & IDCDS_WL) {
				printf("rb%d: write locked\n", dkunit(bp));
				bp->b_flags |= B_ERROR;
			} else if (++um->um_tab.b_errcnt > 28 || er&IDC_HARD) {
hard:
				harderr(bp, "rb");
				printf("csr=%b ds=%b\n", er, IDCCSR_BITS, ds, 
				    ui->ui_type?IDCRB80DS_BITS:IDCRB02DS_BITS);
				bp->b_flags |= B_ERROR;
			} else if (er & IDC_DCK) {
				switch (er & IDC_ECS) {
				case IDC_ECS_NONE:
					break;
				case IDC_ECS_SOFT:
					idcecc(ui);
					break;
				case IDC_ECS_HARD:
				default:
					goto hard;
				}
			} else
				/* recoverable error, set up for retry */
				goto seek;
		}
		if ((sc->sc_resid -= sc->sc_bcnt) != 0) {
			sc->sc_ubaddr += sc->sc_bcnt;
			/*
			 * Current transfer is complete, have
			 * we overflowed to the next track?
			 */
			if ((sc->sc_sect += sc->sc_bcnt/st->nbps) == st->nsect) {
				sc->sc_sect = 0;
				if (++sc->sc_trk == st->ntrak) {
					sc->sc_trk = 0;
					sc->sc_cyl++;
				} else if (ui->ui_type) {
					/*
					 * RB80 can change heads just by
					 * loading the disk address register.
					 */
					idcaddr->idccsr = IDC_SEEK|IDC_CRDY|
					    IDC_IE|(unit<<8);
					printd(", change to track 0x%x", sc->sc_dar);
					idcaddr->idcdar = sc->sc_dar;
					idccyl[ui->ui_unit].dar_dar = sc->sc_dar;
					idccyl[ui->ui_unit].dar_sect = 0;
					goto cont;
				}
				/*
				 * Changing tracks on RB02 or cylinders
				 * on RB80, start a seek.
				 */
seek:
				cmd = IDC_IE|IDC_SEEK|(unit<<8);
				idcaddr->idccsr = cmd|IDC_CRDY;
				idcaddr->idcdar = sc->sc_dar;
				printd(", seek to 0x%x\n", sc->sc_dar);
				idccyl[ui->ui_unit].dar_dar = sc->sc_dar;
				idccyl[ui->ui_unit].dar_sect = 0;
				sc->sc_bcnt = 0;
				idcaddr->idccsr = cmd;
				if (ui->ui_type) {
					if (idcwait(idcaddr, 10) == 0)
						return;
					idcaddr->idccsr &= ~IDC_ATTN;
					if (idcaddr->idccsr & IDC_DRDY)
						goto top;
				}
			} else {
				/*
				 * Continue transfer on current track.
				 */
cont:
				sc->sc_bcnt = (st->nsect-sc->sc_sect)*st->nbps;
				if (sc->sc_bcnt > sc->sc_resid)
					sc->sc_bcnt = sc->sc_resid;
				if (bp->b_flags & B_READ)
					cmd = IDC_IE|IDC_READ|(unit<<8);
				else
					cmd = IDC_IE|IDC_WRITE|(unit<<8);
				idcaddr->idccsr = cmd|IDC_CRDY;
				idcaddr->idcbar = sc->sc_ubaddr;
				idcaddr->idcbcr = -sc->sc_bcnt;
				idcaddr->idcdar = sc->sc_dar;
				printd(", continue I/O 0x%x, 0x%x\n", sc->sc_dar, sc->sc_bcnt);
				idcaddr->idccsr = cmd;
				um->um_tab.b_active = 2;
			}
			return;
		}
		/*
		 * Entire transfer is done, clean up.
		 */
		ubadone(um);
		dk_busy &= ~(1 << ui->ui_dk);
		um->um_tab.b_active = 0;
		um->um_tab.b_errcnt = 0;
		um->um_tab.b_actf = dp->b_forw;
		dp->b_active = 0;
		dp->b_errcnt = 0;
		dp->b_actf = bp->av_forw;
		trace('done', dp); trace(um->um_tab.b_actf, dp->b_actf);
		bp->b_resid = sc->sc_resid;
		printd(", iodone, resid 0x%x\n", bp->b_resid);
		iodone(bp);
		if (dp->b_actf)
			if (idcustart(ui))
				return;
	} else if (um->um_tab.b_active == 1) {
		/*
		 * Got an interrupt while setting up for a command
		 * or doing a mid-transfer seek.  Save any attentions
		 * for later and process a mid-transfer seek complete.
		 */
		as = idcaddr->idccsr;
		idcaddr->idccsr = IDC_IE|IDC_CRDY|(as&IDC_ATTN);
		as = (as >> 16) & 0xf;
		unit = sc->sc_unit;
		sc->sc_softas |= as & ~(1<<unit);
		if (as & (1<<unit)) {
			printd(", seek1 complete");
			um->um_tab.b_active = 2;
			goto top;
		}
		printd(", as1 %o\n", as);
		return;
	}
	/*
	 * Process any seek initiated or complete interrupts.
	 */
	as = idcaddr->idccsr;
	idcaddr->idccsr = IDC_IE|IDC_CRDY|(as&IDC_ATTN);
	as = ((as >> 16) & 0xf) | sc->sc_softas;
	sc->sc_softas = 0;
	trace('as', as);
	printd(", as %o", as);
	for (unit = 0; unit < NRB; unit++)
		if (as & (1<<unit)) {
			as &= ~(1<<unit);
			idcaddr->idccsr = IDC_IE|IDC_CRDY|(unit<<8);
			ui = idcdinfo[unit];
			if (ui) {
				printd(", attn unit %d", unit);
				if (idcaddr->idccsr & IDC_DRDY)
					if (idcustart(ui)) {
						sc->sc_softas = as;
						return;
					}
			} else {
				printd(", unsol. intr. unit %d", unit);
			}
		}
	printd("\n");
	if (um->um_tab.b_actf && um->um_tab.b_active == 0) {
		trace('stum',um->um_tab.b_actf);
		idcstart(um);
	}
}

idcwait(addr, cnt)
	register struct idcdevice *addr;
	register int cnt;
{
	register int i;

	while (--cnt && (addr->idccsr & IDC_CRDY) == 0)
		for (i = 10; i; i--)
			;
	return (cnt);
}

idcread(dev, uio)
	dev_t dev;
	struct uio *uio;
{
	register int unit = minor(dev) >> 3;

	if (unit >= NRB)
		return (ENXIO);
	return (physio(idcstrategy, &ridcbuf[unit], dev, B_READ, minphys, uio));
}

idcwrite(dev, uio)
	dev_t dev;
	struct uio *uio;
{
	register int unit = minor(dev) >> 3;

	if (unit >= NRB)
		return (ENXIO);
	return (physio(idcstrategy, &ridcbuf[unit], dev, B_WRITE, minphys, uio));
}

idcecc(ui)
	register struct uba_device *ui;
{
	register struct idcdevice *idc = (struct idcdevice *)ui->ui_addr;
	register struct buf *bp = idcutab[ui->ui_unit].b_actf;
	register struct uba_ctlr *um = ui->ui_mi;
	register struct idcst *st;
	register int i;
	struct uba_regs *ubp = ui->ui_hd->uh_uba;
	int bit, byte, mask;
	caddr_t addr;
	int reg, npf, o;
	int cn, tn, sn;

	printf("idcecc: HELP!\n");
	npf = btop(idc->idcbcr + idc_softc.sc_bcnt) - 1;;
	reg = btop(idc_softc.sc_ubaddr) + npf;
	o = (int)bp->b_un.b_addr & PGOFSET;
	st = &idcst[ui->ui_type];
	cn = idc_softc.sc_cyl;
	tn = idc_softc.sc_trk;
	sn = idc_softc.sc_sect;
	um->um_tab.b_active = 1;	/* Either complete or continuing... */
	printf("rb%d%c: soft ecc sn%d\n", dkunit(bp),
	    'a'+(minor(bp->b_dev)&07),
	    (cn*st->ntrak + tn) * st->nsect + sn + npf);
	mask = idc->idceccpat;
	i = idc->idceccpos - 1;		/* -1 makes 0 origin */
	bit = i&07;
	i = (i&~07)>>3;
	byte = i + o;
	while (i < 512 && (int)ptob(npf)+i < idc_softc.sc_bcnt && bit > -11) {
		addr = ptob(ubp->uba_map[reg+btop(byte)].pg_pfnum)+
		    (byte & PGOFSET);
		putmemc(addr, getmemc(addr)^(mask<<bit));
		byte++;
		i++;
		bit -= 8;
	}
	idc_softc.sc_bcnt += idc->idcbcr;
	um->um_tab.b_errcnt = 0;	/* error has been corrected */
	return;
}

idcreset(uban)
	int uban;
{
	register struct uba_ctlr *um;
	register struct uba_device *ui;
	register unit;

	if ((um = idcminfo[0]) == 0 || um->um_ubanum != uban ||
	    um->um_alive == 0)
		return;
	printf(" idc0");
	um->um_tab.b_active = 0;
	um->um_tab.b_actf = um->um_tab.b_actl = 0;
	if (um->um_ubinfo) {
		printf("<%d>", (um->um_ubinfo>>28)&0xf);
		ubadone(um);
	}
	for (unit = 0; unit < NRB; unit++) {
		if ((ui = idcdinfo[unit]) == 0 || ui->ui_alive == 0)
			continue;
		idcutab[unit].b_active = 0;
		(void) idcustart(ui);
	}
	(void) idcstart(um);
}

idcwatch()
{
	register struct uba_ctlr *um;
	register unit;

	timeout(idcwatch, (caddr_t)0, hz);
	um = idcminfo[0];
	if (um == 0 || um->um_alive == 0)
		return;
	if (um->um_tab.b_active == 0) {
		for (unit = 0; unit < NRB; unit++)
			if (idcutab[unit].b_active)
				goto active;
		idcwticks = 0;
		return;
	}
active:
	idcwticks++;
	if (idcwticks >= 20) {
		idcwticks = 0;
		printf("idc0: lost interrupt\n");
		idcintr(0);
	}
}

idcdump(dev)
	dev_t dev;
{
#ifdef notdef
	struct idcdevice *idcaddr;
	char *start;
	int num, blk, unit, dbsize;
	struct size *sizes;
	register struct uba_regs *uba;
	register struct uba_device *ui;
	struct idcst *st;

	unit = minor(dev) >> 3;
	if (unit >= NRB)
		return (ENXIO);
#define	phys(cast, addr) ((cast)((int)addr & 0x7fffffff))
	ui = phys(struct uba_device *, idcdinfo[unit]);
	if (ui->ui_alive == 0)
		return (ENXIO);
	uba = phys(struct uba_hd *, ui->ui_hd)->uh_physuba;
	ubainit(uba);
	idcaddr = (struct idcdevice *)ui->ui_physaddr;
	num = maxfree;
	start = 0;
/***
	idcaddr->idccs1 = IDC_CCLR;
	idcaddr->idccs2 = unit;
	idcaddr->idccs1 = idctypes[ui->ui_type]|IDC_DCLR|IDC_GO;
	idcwait(idcaddr);
	dbsize = 20 or 31;
***/
	st = &idcst[ui->ui_type];
	sizes = phys(struct size *, st->sizes);
	if (dumplo < 0 || dumplo + num >= sizes[minor(dev)&07].nblocks)
		return (EINVAL);
	while (num > 0) {
		register struct pte *io;
		register int i;
		int cn, sn, tn;
		daddr_t bn;

		blk = num > dbsize ? dbsize : num;
		io = uba->uba_map;
		for (i = 0; i < blk; i++)
			*(int *)io++ = (btop(start)+i) | (1<<21) | UBAMR_MRV;
		*(int *)io = 0;
		bn = dumplo + btop(start);
		cn = bn/st->nspc + sizes[minor(dev)&07].cyloff;
		sn = bn%st->nspc;
		tn = sn/st->nsect;
		sn = sn%st->nsect;
/***
		idcaddr->idccyl = cn;
		rp = (short *) &idcaddr->idcda;
		*rp = (tn << 8) + sn;
		*--rp = 0;
		*--rp = -blk*NBPG / sizeof (short);
		*--rp = idctypes[ui->ui_type]|IDC_GO|IDC_WRITE;
		idcwait(idcaddr);
***/
		if (idcaddr->idccsr & IDC_ERR)
			return (EIO);
		start += blk*NBPG;
		num -= blk;
	}
	return (0);
#else
	return (ENXIO);
#endif
}
#endif