kdb.c

早期freebsd实现

			return (-1);
		}
	}
	if ((ka->kdb_sa & STEP0MASK) != KDB_STEP1) {
		printf("kdb%d: init failed, sa=%b\n", ki->ki_ctlr,
			ka->kdb_sa, kdbsr_bits);
		return (-1);
	}

	/*
	 * Success!  Record new state, and start step 1 initialisation.
	 * The rest is done in the interrupt handler.
	 */
	ki->ki_state = ST_STEP1;
	ka->kdb_bi.bi_intrdes = 1 << mastercpu;
#ifdef unneeded /* is it? */
	ka->kdb_bi.bi_csr = (ka->kdb_bi.bi_csr&~BICSR_ARB_MASK)|BICSR_ARB_???;
#endif
	ka->kdb_bi.bi_bcicsr |= BCI_STOPEN | BCI_IDENTEN | BCI_UINTEN |
		BCI_INTEN;

/* I THINK THIS IS WRONG */
/* Mach uses 0x601d0, which includes IPL16, but 1d0 is IPL17, nexzvec...? */
	ka->kdb_bi.bi_eintrcsr = BIEIC_IPL15 | ki->ki_vec;	/* ??? */
/* END I THINK WRONG */

	ka->kdb_bi.bi_uintrcsr = ki->ki_vec;
	ka->kdb_sw = KDB_ERR | (NCMDL2 << 11) | (NRSPL2 << 8) | KDB_IE |
		(ki->ki_vec >> 2);
	return (0);
}

/*
 * Open a drive.
 */
/*ARGSUSED*/
kdbopen(dev, flag)
	dev_t dev;
	int flag;
{
	register int unit;
	register struct uba_device *ui;
	register struct kdbinfo *ki;
	int s;

	/*
	 * Make sure this is a reasonable open request.
	 */
	unit = kdbunit(dev);
	if (unit >= NKRA || (ui = kdbdinfo[unit]) == 0 || ui->ui_alive == 0)
		return (ENXIO);

	/*
	 * Make sure the controller is running, by (re)initialising it if
	 * necessary.
	 */
	ki = &kdbinfo[ui->ui_ctlr];
	s = spl5();
	if (ki->ki_state != ST_RUN) {
		if (ki->ki_state == ST_IDLE && kdbinit(ki)) {
			splx(s);
			return (EIO);
		}
		/*
		 * In case it does not come up, make sure we will be
		 * restarted in 10 seconds.  This corresponds to the
		 * 10 second timeouts in kdbprobe() and kdbslave().
		 */
		ki->ki_flags |= KDB_DOWAKE;
		timeout(wakeup, (caddr_t)&ki->ki_flags, 10 * hz);
		sleep((caddr_t)&ki->ki_flags, PRIBIO);
		if (ki->ki_state != ST_RUN) {
			splx(s);
			printf("kdb%d: controller hung\n", ui->ui_ctlr);
			return (EIO);
		}
		untimeout(wakeup, (caddr_t)&ki->ki_flags);
	}
	if ((ui->ui_flags & UNIT_ONLINE) == 0) {
		/*
		 * Bring the drive on line so we can find out how
		 * big it is.  If it is not spun up, it will not
		 * come on line; this cannot really be considered
		 * an `error condition'.
		 */
		if (kdb_bringonline(ui, 0)) {
			splx(s);
			printf("%s%d: drive will not come on line\n",
				kdbdriver.ud_dname, unit);
			return (EIO);
		}
	}
	splx(s);
	return (0);
}

/*
 * Bring a drive on line.  In case it fails to respond, we set
 * a timeout on it.  The `nosleep' parameter should be set if
 * we are to spin-wait; otherwise this must be called at spl5().
 */
kdb_bringonline(ui, nosleep)
	register struct uba_device *ui;
	int nosleep;
{
	register struct kdbinfo *ki = &kdbinfo[ui->ui_ctlr];
	register struct mscp *mp;
	int i;

	if (nosleep) {
		mp = mscp_getcp(&ki->ki_mi, MSCP_DONTWAIT);
		if (mp == NULL)
			return (-1);
	} else
		mp = mscp_getcp(&ki->ki_mi, MSCP_WAIT);
	mp->mscp_opcode = M_OP_ONLINE;
	mp->mscp_unit = ui->ui_slave;
	mp->mscp_cmdref = (long)&ui->ui_flags;
	*mp->mscp_addr |= MSCP_OWN | MSCP_INT;
	i = ki->ki_kdb->kdb_ip;

	if (nosleep) {
		i = todr() + 1000;
		while ((ui->ui_flags & UNIT_ONLINE) == 0)
			if (todr() > i)
				return (-1);
	} else {
		timeout(wakeup, (caddr_t)&ui->ui_flags, 10 * hz);
		sleep((caddr_t)&ui->ui_flags, PRIBIO);
		if ((ui->ui_flags & UNIT_ONLINE) == 0)
			return (-1);
		untimeout(wakeup, (caddr_t)&ui->ui_flags);
	}
	return (0);	/* made it */
}

/*
 * Queue a transfer request, and if possible, hand it to the controller.
 *
 * This routine is broken into two so that the internal version
 * kdbstrat1() can be called by the (nonexistent, as yet) bad block
 * revectoring routine.
 */
kdbstrategy(bp)
	register struct buf *bp;
{
	register int unit;
	register struct uba_device *ui;
	register struct size *st;
	daddr_t sz, maxsz;

	/*
	 * Make sure this is a reasonable drive to use.
	 */
	if ((unit = kdbunit(bp->b_dev)) >= NKRA ||
	    (ui = kdbdinfo[unit]) == NULL || ui->ui_alive == 0) {
		bp->b_error = ENXIO;
		bp->b_flags |= B_ERROR;
		biodone(bp);
		return;
	}

	/*
	 * Determine the size of the transfer, and make sure it is
	 * within the boundaries of the drive.
	 */
	sz = (bp->b_bcount + 511) >> 9;
	st = &kdbtypes[ui->ui_type].ut_sizes[kdbpart(bp->b_dev)];
	if ((maxsz = st->nblocks) < 0)
		maxsz = ra_dsize[unit] - st->blkoff;
	if (bp->b_blkno < 0 || bp->b_blkno + sz > maxsz ||
	    st->blkoff >= ra_dsize[unit]) {
		/* if exactly at end of disk, return an EOF */
		if (bp->b_blkno == maxsz)
			bp->b_resid = bp->b_bcount;
		else {
			bp->b_error = EINVAL;
			bp->b_flags |= B_ERROR;
		}
		biodone(bp);
		return;
	}
	kdbstrat1(bp);
}

/*
 * Work routine for kdbstrategy.
 */
kdbstrat1(bp)
	register struct buf *bp;
{
	register int unit = kdbunit(bp->b_dev);
	register struct buf *dp;
	register struct kdbinfo *ki;
	struct uba_device *ui;
	int s;

	/*
	 * Append the buffer to the drive queue, and if it is not
	 * already there, the drive to the controller queue.  (However,
	 * if the drive queue is marked to be requeued, we must be
	 * awaiting an on line or get unit status command; in this
	 * case, leave it off the controller queue.)
	 */
	ui = kdbdinfo[unit];
	ki = &kdbinfo[ui->ui_ctlr];
	dp = &kdbutab[unit];
	s = spl5();
	APPEND(bp, dp, av_forw);
	if (dp->b_active == 0 && (ui->ui_flags & UNIT_REQUEUE) == 0) {
		APPEND(dp, &ki->ki_tab, b_forw);
		dp->b_active++;
	}

	/*
	 * Start activity on the controller.
	 */
	kdbstart(ki);
	splx(s);
}

/*
 * Find the physical address of some contiguous PTEs that map the
 * transfer described in `bp', creating them (by copying) if
 * necessary.  Store the physical base address of the map through
 * mapbase, and the page offset through offset, and any resource
 * information in *info (or 0 if none).
 *
 * If we cannot allocate space, return a nonzero status.
 */
int
kdbmap(ki, bp, mapbase, offset, info)
	struct kdbinfo *ki;
	register struct buf *bp;
	long *mapbase, *offset;
	int *info;
{
	register struct pte *spte, *dpte;
	register struct proc *rp;
	register int i, a, o;
	u_int v;
	int npf;

	o = (int)bp->b_un.b_addr & PGOFSET;

	/* handle contiguous cases */
	if ((bp->b_flags & B_PHYS) == 0) {
		spte = kvtopte(bp->b_un.b_addr);
		kdbstats.ks_sys++;
		*mapbase = PHYS(long, spte);
		*offset = o;
		*info = 0;
		return (0);
	}
	if (bp->b_flags & B_PAGET) {
		spte = &Usrptmap[btokmx((struct pte *)bp->b_un.b_addr)];
if (spte->pg_v == 0) panic("kdbmap");
		kdbstats.ks_paget++;
		*mapbase = PHYS(long, spte);
		*offset = o;
		*info = 0;
		return (0);
	}

	/* potentially discontiguous or invalid ptes */
	v = btop(bp->b_un.b_addr);
	rp = bp->b_flags & B_DIRTY ? &proc[2] : bp->b_proc;
	if (bp->b_flags & B_UAREA)
		spte = &rp->p_addr[v];
	else
		spte = vtopte(rp, v);
	npf = btoc(bp->b_bcount + o);

#ifdef notdef
	/*
	 * The current implementation of the VM system requires
	 * that all of these be done with a copy.  Even if the
	 * PTEs could be used now, they may be snatched out from
	 * under us later.  It would be nice if we could stop that....
	 */

	/* check for invalid */
	/* CONSIDER CHANGING VM TO VALIDATE PAGES EARLIER */
	for (dpte = spte, i = npf; --i >= 0; dpte++)
		if (dpte->pg_v == 0)
			goto copy1;
	/*
	 * Check for discontiguous physical pte addresses.  It is
	 * not necessary to check each pte, since they come in clumps
	 * of pages.
	 */
	i = howmany(npf + (((int)spte & PGOFSET) / sizeof (*spte)), NPTEPG);
	/* often i==1, and we can avoid work */
	if (--i > 0) {
		dpte = kvtopte(spte);
		a = dpte->pg_pfnum;
		while (--i >= 0)
			if ((++dpte)->pg_pfnum != ++a)
				goto copy2;
	}

	/* made it */
	kdbstats.ks_contig++;
	*mapbase = kvtophys(spte);
	*offset = o;
	*info = 0;
	return (0);

copy1:
	kdbstats.ks_inval++;		/* temp */
copy2:
#endif /* notdef */
	kdbstats.ks_copies++;
	i = npf + 1;
	if ((a = rmalloc(ki->ki_map, (long)i)) == 0) {
		kdbstats.ks_mapwait++;
		return (-1);
	}
	*info = (i << 16) | a;
	a--;
	/* if offset > PGOFSET, btop(offset) indexes mapbase */
	*mapbase = ki->ki_ptephys;
	*offset = (a << PGSHIFT) | o;
	dpte = &ki->ki_pte[a];
	while (--i > 0)
		*(int *)dpte++ = PG_V | *(int *)spte++;
	*(int *)dpte = 0;
	return (0);
}

#define	KDBFREE(ki, info) if (info) \
	rmfree((ki)->ki_map, (long)((info) >> 16), (long)((info) & 0xffff))

/*
 * Start up whatever transfers we can find.
 * Note that kdbstart() must be called at spl5().
 */
kdbstart(ki)
	register struct kdbinfo *ki;
{
	register struct buf *bp, *dp;
	register struct mscp *mp;
	register struct uba_device *ui;
	long mapbase, offset;
	int info, ncmd = 0;

	/*
	 * If it is not running, try (again and again...) to initialise
	 * it.  If it is currently initialising just ignore it for now.
	 */
	if (ki->ki_state != ST_RUN) {
		if (ki->ki_state == ST_IDLE && kdbinit(ki))
			printf("kdb%d: still hung\n", ki->ki_ctlr);
		return;
	}

loop:
	/* if insufficient credit, avoid overhead */
	if (ki->ki_mi.mi_credits <= MSCP_MINCREDITS)
		goto out;

	/*
	 * Service the drive at the head of the queue.  It may not
	 * need anything; eventually this will finish up the close
	 * protocol, but that is yet to be implemented here.
	 */
	if ((dp = ki->ki_tab.b_actf) == NULL)
		goto out;
	if ((bp = dp->b_actf) == NULL) {
		dp->b_active = 0;
		ki->ki_tab.b_actf = dp->b_forw;
		goto loop;
	}

	if (ki->ki_kdb->kdb_sa & KDB_ERR) {	/* ctlr fatal error */
		kdbsaerror(ki);
		goto out;
	}

	 /* find or create maps for this transfer */
	 if (kdbmap(ki, bp, &mapbase, &offset, &info))
		goto out;	/* effectively, resource wait */

	/*
	 * Get an MSCP packet, then figure out what to do.  If
	 * we cannot get a command packet, the command ring may
	 * be too small:  We should have at least as many command
	 * packets as credits, for best performance.
	 */
	if ((mp = mscp_getcp(&ki->ki_mi, MSCP_DONTWAIT)) == NULL) {
		if (ki->ki_mi.mi_credits > MSCP_MINCREDITS &&
		    (ki->ki_flags & KDB_GRIPED) == 0) {
			log(LOG_NOTICE, "kdb%d: command ring too small\n",
				ki->ki_ctlr);
			ki->ki_flags |= KDB_GRIPED;/* complain only once */
		}
		KDBFREE(ki, info);
		goto out;
	}

	/*
	 * Bring the drive on line if it is not already.  Get its status
	 * if we do not already have it.  Otherwise just start the transfer.
	 */
	ui = kdbdinfo[kdbunit(bp->b_dev)];
	if ((ui->ui_flags & UNIT_ONLINE) == 0) {
		mp->mscp_opcode = M_OP_ONLINE;
		goto common;
	}
	if ((ui->ui_flags & UNIT_HAVESTATUS) == 0) {
		mp->mscp_opcode = M_OP_GETUNITST;
common:
if (ui->ui_flags & UNIT_REQUEUE) panic("kdbstart");
		/*
		 * Take the drive off the controller queue.  When the
		 * command finishes, make sure the drive is requeued.
		 * Give up any mapping (not needed now).  This last is
		 * not efficient, but is rare.
		 */
		KDBFREE(ki, info);
		ki->ki_tab.b_actf = dp->b_forw;
		dp->b_active = 0;
		ui->ui_flags |= UNIT_REQUEUE;
		mp->mscp_unit = ui->ui_slave;
		*mp->mscp_addr |= MSCP_OWN | MSCP_INT;
		ncmd++;
		goto loop;
	}

	mp->mscp_opcode = (bp->b_flags & B_READ) ? M_OP_READ : M_OP_WRITE;
	mp->mscp_unit = ui->ui_slave;
	mp->mscp_seq.seq_lbn = bp->b_blkno +
		kdbtypes[ui->ui_type].ut_sizes[kdbpart(bp->b_dev)].blkoff;
	mp->mscp_seq.seq_bytecount = bp->b_bcount;

	mp->mscp_seq.seq_buffer = offset | KDB_MAP;
	mp->mscp_seq.seq_mapbase = mapbase;

	/* profile the drive */
	if (ui->ui_dk >= 0) {
		dk_busy |= 1 << ui->ui_dk;
		dk_xfer[ui->ui_dk]++;
		dk_wds[ui->ui_dk] += bp->b_bcount >> 6;
	}

	/*
	 * Fill in the rest of the MSCP packet and move the buffer to the
	 * I/O wait queue.
	 */
	mscp_go(&ki->ki_mi, mp, info);
	ncmd++;			/* note the transfer */
	ki->ki_tab.b_active++;	/* another one going */
	goto loop;

out:
	if (ncmd >= KS_MAXC)
		ncmd = KS_MAXC - 1;
	kdbstats.ks_cmd[ncmd]++;
	if (ncmd)		/* start some transfers */
		ncmd = ki->ki_kdb->kdb_ip;
}

/* ARGSUSED */
kdbiodone(mi, bp, info)
	struct mscp_info *mi;
	struct buf *bp;
	int info;
{
	register struct kdbinfo *ki = &kdbinfo[mi->mi_ctlr];

	KDBFREE(ki, info);
	biodone(bp);
	ki->ki_tab.b_active--;	/* another one done */
}

/*
 * The error bit was set in the controller status register.  Gripe,
 * reset the controller, requeue pending transfers.
 */
kdbsaerror(ki)
	register struct kdbinfo *ki;
{

	printf("kdb%d: controller error, sa=%b\n", ki->ki_ctlr,
		ki->ki_kdb->kdb_sa, kdbsr_bits);
	mscp_requeue(&ki->ki_mi);
	(void) kdbinit(ki);
}

/*
 * Interrupt routine.  Depending on the state of the controller,
 * continue initialisation, or acknowledge command and response
 * interrupts, and process responses.
 */
kdbintr(ctlr)
	int ctlr;
{
	register struct kdbinfo *ki = &kdbinfo[ctlr];
	register struct kdb_regs *kdbaddr = ki->ki_kdb;
	register struct mscp *mp;
	register int i;

	ki->ki_wticks = 0;	/* reset interrupt watchdog */

	/*
	 * Combinations during steps 1, 2, and 3: STEPnMASK
	 * corresponds to which bits should be tested;
	 * STEPnGOOD corresponds to the pattern that should
	 * appear after the interrupt from STEPn initialisation.
	 * All steps test the bits in ALLSTEPS.
	 */
#define	ALLSTEPS	(KDB_ERR|KDB_STEP4|KDB_STEP3|KDB_STEP2|KDB_STEP1)

#define	STEP1MASK	(ALLSTEPS | KDB_IE | KDB_NCNRMASK)
#define	STEP1GOOD	(KDB_STEP2 | KDB_IE | (NCMDL2 << 3) | NRSPL2)

#define	STEP2MASK	(ALLSTEPS | KDB_IE | KDB_IVECMASK)
#define	STEP2GOOD	(KDB_STEP3 | KDB_IE | (ki->ki_vec >> 2))

#define	STEP3MASK	ALLSTEPS
#define	STEP3GOOD	KDB_STEP4

	switch (ki->ki_state) {

	case ST_IDLE:
		/*
		 * Ignore unsolicited interrupts.
		 */
		log(LOG_WARNING, "kdb%d: stray intr\n", ctlr);
		return;

	case ST_STEP1:
		/*
		 * Begin step two initialisation.
		 */
		if ((kdbaddr->kdb_sa & STEP1MASK) != STEP1GOOD) {
			i = 1;
initfailed:
			printf("kdb%d: init step %d failed, sa=%b\n",
				ctlr, i, kdbaddr->kdb_sa, kdbsr_bits);
			ki->ki_state = ST_IDLE;
			if (ki->ki_flags & KDB_DOWAKE) {
				ki->ki_flags &= ~KDB_DOWAKE;
				wakeup((caddr_t)&ki->ki_flags);
			}
			return;
		}
		kdbaddr->kdb_sw = PHYS(int, &ki->ki_ca.ca_rspdsc[0]);
		ki->ki_state = ST_STEP2;
		return;

	case ST_STEP2:
		/*
		 * Begin step 3 initialisation.
		 */
		if ((kdbaddr->kdb_sa & STEP2MASK) != STEP2GOOD) {
			i = 2;
			goto initfailed;
		}
		kdbaddr->kdb_sw = PHYS(int, &ki->ki_ca.ca_rspdsc[0]) >> 16;
		ki->ki_state = ST_STEP3;
		return;

	case ST_STEP3:
		/*
		 * Set controller characteristics (finish initialisation).
		 */
		if ((kdbaddr->kdb_sa & STEP3MASK) != STEP3GOOD) {
			i = 3;
			goto initfailed;
		}
		i = kdbaddr->kdb_sa & 0xff;
		if (i != ki->ki_micro) {
			ki->ki_micro = i;
			printf("kdb%d: version %d model %d\n",
				ctlr, i & 0xf, i >> 4);
		}

		kdbaddr->kdb_sw = KDB_GO;

		/* initialise hardware data structures */
		for (i = 0, mp = ki->ki_rsp; i < NRSP; i++, mp++) {
			ki->ki_ca.ca_rspdsc[i] = MSCP_OWN | MSCP_INT |
				PHYS(long, &ki->ki_rsp[i].mscp_cmdref);