uba.c

早期freebsd实现

/*
 * Copyright (c) 1982, 1986 The Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@(#)uba.c	7.10 (Berkeley) 12/16/90
 */

#include "sys/param.h"
#include "sys/systm.h"
#include "sys/map.h"
#include "sys/buf.h"
#include "sys/vm.h"
#include "sys/user.h"
#include "sys/proc.h"
#include "sys/conf.h"
#include "sys/dkstat.h"
#include "sys/kernel.h"

#include "../include/pte.h"
#include "../include/cpu.h"
#include "../include/mtpr.h"
#include "../vax/nexus.h"
#include "ubareg.h"
#include "ubavar.h"

#ifdef DW780
char	ubasr_bits[] = UBASR_BITS;
#endif

#define	spluba	spl7		/* IPL 17 */

/*
 * Do transfer on device argument.  The controller
 * and uba involved are implied by the device.
 * We queue for resource wait in the uba code if necessary.
 * We return 1 if the transfer was started, 0 if it was not.
 *
 * The onq argument must be zero iff the device is not on the
 * queue for this UBA.  If onq is set, the device must be at the
 * head of the queue.  In any case, if the transfer is started,
 * the device will be off the queue, and if not, it will be on.
 *
 * Drivers that allocate one BDP and hold it for some time should
 * set ud_keepbdp.  In this case um_bdp tells which BDP is allocated
 * to the controller, unless it is zero, indicating that the controller
 * does not now have a BDP.
 */
ubaqueue(ui, onq)
	register struct uba_device *ui;
	int onq;
{
	register struct uba_ctlr *um = ui->ui_mi;
	register struct uba_hd *uh;
	register struct uba_driver *ud;
	register int s, unit;

	uh = &uba_hd[um->um_ubanum];
	ud = um->um_driver;
	s = spluba();
	/*
	 * Honor exclusive BDP use requests.
	 */
	if (ud->ud_xclu && uh->uh_users > 0 || uh->uh_xclu)
		goto rwait;
	if (ud->ud_keepbdp) {
		/*
		 * First get just a BDP (though in fact it comes with
		 * one map register too).
		 */
		if (um->um_bdp == 0) {
			um->um_bdp = uballoc(um->um_ubanum,
				(caddr_t)0, 0, UBA_NEEDBDP|UBA_CANTWAIT);
			if (um->um_bdp == 0)
				goto rwait;
		}
		/* now share it with this transfer */
		um->um_ubinfo = ubasetup(um->um_ubanum,
			um->um_tab.b_actf->b_actf,
			um->um_bdp|UBA_HAVEBDP|UBA_CANTWAIT);
	} else
		um->um_ubinfo = ubasetup(um->um_ubanum,
			um->um_tab.b_actf->b_actf, UBA_NEEDBDP|UBA_CANTWAIT);
	if (um->um_ubinfo == 0)
		goto rwait;
	uh->uh_users++;
	if (ud->ud_xclu)
		uh->uh_xclu = 1;
	splx(s);
	if (ui->ui_dk >= 0) {
		unit = ui->ui_dk;
		dk_busy |= 1<<unit;
		dk_xfer[unit]++;
		dk_wds[unit] += um->um_tab.b_actf->b_actf->b_bcount>>6;
	}
	if (onq)
		uh->uh_actf = ui->ui_forw;
	(*ud->ud_dgo)(um);
	return (1);
rwait:
	if (!onq) {
		ui->ui_forw = NULL;
		if (uh->uh_actf == NULL)
			uh->uh_actf = ui;
		else
			uh->uh_actl->ui_forw = ui;
		uh->uh_actl = ui;
	}
	splx(s);
	return (0);
}

ubadone(um)
	register struct uba_ctlr *um;
{
	register struct uba_hd *uh = &uba_hd[um->um_ubanum];

	if (um->um_driver->ud_xclu)
		uh->uh_xclu = 0;
	uh->uh_users--;
	if (um->um_driver->ud_keepbdp)
		um->um_ubinfo &= ~BDPMASK;	/* keep BDP for misers */
	ubarelse(um->um_ubanum, &um->um_ubinfo);
}

/*
 * Allocate and setup UBA map registers, and bdp's
 * Flags says whether bdp is needed, whether the caller can't
 * wait (e.g. if the caller is at interrupt level).
 * Return value encodes map register plus page offset,
 * bdp number and number of map registers.
 */
ubasetup(uban, bp, flags)
	int uban;
	register struct buf *bp;
	register int flags;
{
	register struct uba_hd *uh = &uba_hd[uban];
	register struct pte *pte, *io;
	register int npf;
	int pfnum, temp;
	int reg, bdp;
	unsigned v;
	struct proc *rp;
	int a, o, ubinfo;

#ifdef DW730
	if (uh->uh_type == DW730)
		flags &= ~UBA_NEEDBDP;
#endif
#ifdef QBA
	if (uh->uh_type == QBA)
		flags &= ~UBA_NEEDBDP;
#endif
	o = (int)bp->b_un.b_addr & PGOFSET;
	npf = btoc(bp->b_bcount + o) + 1;
	if (npf > UBA_MAXNMR)
		panic("uba xfer too big");
	a = spluba();
	while ((reg = rmalloc(uh->uh_map, (long)npf)) == 0) {
		if (flags & UBA_CANTWAIT) {
			splx(a);
			return (0);
		}
		uh->uh_mrwant++;
		sleep((caddr_t)&uh->uh_mrwant, PSWP);
	}
	if ((flags & UBA_NEED16) && reg + npf > 128) {
		/*
		 * Could hang around and try again (if we can ever succeed).
		 * Won't help any current device...
		 */
		rmfree(uh->uh_map, (long)npf, (long)reg);
		splx(a);
		return (0);
	}
	bdp = 0;
	if (flags & UBA_NEEDBDP) {
		while ((bdp = ffs((long)uh->uh_bdpfree)) == 0) {
			if (flags & UBA_CANTWAIT) {
				rmfree(uh->uh_map, (long)npf, (long)reg);
				splx(a);
				return (0);
			}
			uh->uh_bdpwant++;
			sleep((caddr_t)&uh->uh_bdpwant, PSWP);
		}
		uh->uh_bdpfree &= ~(1 << (bdp-1));
	} else if (flags & UBA_HAVEBDP)
		bdp = (flags >> 28) & 0xf;
	splx(a);
	reg--;
	ubinfo = UBAI_INFO(o, reg, npf, bdp);
	temp = (bdp << 21) | UBAMR_MRV;
	if (bdp && (o & 01))
		temp |= UBAMR_BO;
	if ((bp->b_flags & B_PHYS) == 0)
		pte = kvtopte(bp->b_un.b_addr);
	else if (bp->b_flags & B_PAGET)
		pte = &Usrptmap[btokmx((struct pte *)bp->b_un.b_addr)];
	else {
		rp = bp->b_flags&B_DIRTY ? &proc[2] : bp->b_proc;
		v = btop(bp->b_un.b_addr);
		if (bp->b_flags & B_UAREA)
			pte = &rp->p_addr[v];
		else
			pte = vtopte(rp, v);
	}
	io = &uh->uh_mr[reg];
	while (--npf > 0) {
		pfnum = pte->pg_pfnum;
		if (pfnum == 0)
			panic("uba zero uentry");
		pte++;
		*(int *)io++ = pfnum | temp;
	}
	*(int *)io = 0;
	return (ubinfo);
}

/*
 * Non buffer setup interface... set up a buffer and call ubasetup.
 */
uballoc(uban, addr, bcnt, flags)
	int uban;
	caddr_t addr;
	int bcnt, flags;
{
	struct buf ubabuf;

	ubabuf.b_un.b_addr = addr;
	ubabuf.b_flags = B_BUSY;
	ubabuf.b_bcount = bcnt;
	/* that's all the fields ubasetup() needs */
	return (ubasetup(uban, &ubabuf, flags));
}
 
/*
 * Release resources on uba uban, and then unblock resource waiters.
 * The map register parameter is by value since we need to block
 * against uba resets on 11/780's.
 */
ubarelse(uban, amr)
	int *amr;
{
	register struct uba_hd *uh = &uba_hd[uban];
	register int bdp, reg, npf, s;
	int mr;
 
	/*
	 * Carefully see if we should release the space, since
	 * it may be released asynchronously at uba reset time.
	 */
	s = spluba();
	mr = *amr;
	if (mr == 0) {
		/*
		 * A ubareset() occurred before we got around
		 * to releasing the space... no need to bother.
		 */
		splx(s);
		return;
	}
	*amr = 0;
	bdp = UBAI_BDP(mr);
	if (bdp) {
		switch (uh->uh_type) {
#ifdef DWBUA
		case DWBUA:
			BUA(uh->uh_uba)->bua_dpr[bdp] |= BUADPR_PURGE;
			break;
#endif
#ifdef DW780
		case DW780:
			uh->uh_uba->uba_dpr[bdp] |= UBADPR_BNE;
			break;
#endif
#ifdef DW750
		case DW750:
			uh->uh_uba->uba_dpr[bdp] |=
			    UBADPR_PURGE|UBADPR_NXM|UBADPR_UCE;
			break;
#endif
		default:
			break;
		}
		uh->uh_bdpfree |= 1 << (bdp-1);		/* atomic */
		if (uh->uh_bdpwant) {
			uh->uh_bdpwant = 0;
			wakeup((caddr_t)&uh->uh_bdpwant);
		}
	}
	/*
	 * Put back the registers in the resource map.
	 * The map code must not be reentered,
	 * nor can the registers be freed twice.
	 * Unblock interrupts once this is done.
	 */
	npf = UBAI_NMR(mr);
	reg = UBAI_MR(mr) + 1;
	rmfree(uh->uh_map, (long)npf, (long)reg);
	splx(s);

	/*
	 * Wakeup sleepers for map registers,
	 * and also, if there are processes blocked in dgo(),
	 * give them a chance at the UNIBUS.
	 */
	if (uh->uh_mrwant) {
		uh->uh_mrwant = 0;
		wakeup((caddr_t)&uh->uh_mrwant);
	}
	while (uh->uh_actf && ubaqueue(uh->uh_actf, 1))
		;
}

ubapurge(um)
	register struct uba_ctlr *um;
{
	register struct uba_hd *uh = um->um_hd;
	register int bdp = UBAI_BDP(um->um_ubinfo);

	switch (uh->uh_type) {
#ifdef DWBUA
	case DWBUA:
		BUA(uh->uh_uba)->bua_dpr[bdp] |= BUADPR_PURGE;
		break;
#endif
#ifdef DW780
	case DW780:
		uh->uh_uba->uba_dpr[bdp] |= UBADPR_BNE;
		break;
#endif
#ifdef DW750
	case DW750:
		uh->uh_uba->uba_dpr[bdp] |= UBADPR_PURGE|UBADPR_NXM|UBADPR_UCE;
		break;
#endif
	default:
		break;
	}