if_cx.c

基于组件方式开发操作系统的OSKIT源代码

#if __FreeBSD__ >= 2
		/* Mark the board busy on the first startup.
		 * Never goes idle. */
		kdc_cx[c->board->num].kdc_state = DC_BUSY;
#endif
		/* Initialize channel, enable receiver and transmitter */
		cx_cmd (port, CCR_INITCH | CCR_ENRX | CCR_ENTX);
		/* Repeat the command, to avoid the rev.H bug */
		cx_cmd (port, CCR_INITCH | CCR_ENRX | CCR_ENTX);

		/* Start receiver */
		outw (ARBCNT(port), DMABUFSZ);
		outb (ARBSTS(port), BSTS_OWN24);
		outw (BRBCNT(port), DMABUFSZ);
		outb (BRBSTS(port), BSTS_OWN24);

		/* Raise DTR and RTS */
		cx_chan_dtr (c, 1);
		cx_chan_rts (c, 1);

		/* Enable interrupts */
		outb (IER(port), IER_RXD | IER_TXD);
}

/*
 * Initialization of interface.
 */
void cxinit (int unit)
{
	cx_chan_t *q, *c = cxchan[unit];
	int s = splimp();

	print (("cx%d.%d: cxinit\n", c->board->num, c->num));

	cxdown (c);

	/* Stop all slave subchannels. */
	for (q=c->slaveq; q; q=q->slaveq)
		cxdown (q);

	if (c->ifp->if_flags & IFF_RUNNING) {
		cxup (c);

		/* Start all slave subchannels. */
		for (q=c->slaveq; q; q=q->slaveq)
			cxup (q);
	}
	splx (s);
}

/*
 * Fill transmitter buffer with data.
 */
void cxput (cx_chan_t *c, char b)
{
	struct mbuf *m;
	unsigned char *buf;
	unsigned short port = c->chip->port, len, cnt_port, sts_port;

	/* Choose the buffer. */
	if (b == 'A') {
		buf      = c->atbuf;
		cnt_port = ATBCNT(port);
		sts_port = ATBSTS(port);
	} else {
		buf      = c->btbuf;
		cnt_port = BTBCNT(port);
		sts_port = BTBSTS(port);
	}

	/* Is it busy? */
	if (inb (sts_port) & BSTS_OWN24) {
		if (c->ifp->if_flags & IFF_DEBUG)
			print (("cx%d.%d: tbuf %c already busy, bsts=%b\n",
				c->board->num, c->num, b,
				inb (sts_port), BSTS_BITS));
		goto ret;
	}

	/* Get the packet to send. */
#ifdef __bsdi__
	if (c->sopt.ext) {
		struct p2pcom *p = (struct p2pcom*) c->master;
		int s = splimp ();

		IF_DEQUEUE (&p->p2p_isnd, m)
		if (! m)
			IF_DEQUEUE (&c->master->if_snd, m)
		splx (s);
	} else
#endif
	m = sppp_dequeue (c->master);
	if (! m)
		return;
	len = m->m_pkthdr.len;

	/* Count the transmitted bytes to the subchannel, not the master. */
	c->master->if_obytes -= len + 3;
	c->ifp->if_obytes += len + 3;
	c->stat->obytes += len + 3;

	if (len >= DMABUFSZ) {
		printf ("cx%d.%d: too long packet: %d bytes: ",
			c->board->num, c->num, len);
		printmbuf (m);
		m_freem (m);
		return;
	}
	m_copydata (m, 0, len, buf);
#if NBPFILTER > 0
	if (c->bpf)
		bpf_mtap (c->bpf, m);
#endif
	m_freem (m);

	/* Start transmitter. */
	outw (cnt_port, len);
	outb (sts_port, BSTS_EOFR | BSTS_INTR | BSTS_OWN24);

	if (c->ifp->if_flags & IFF_DEBUG)
		print (("cx%d.%d: enqueue %d bytes to %c\n",
			c->board->num, c->num, len, buf==c->atbuf ? 'A' : 'B'));
ret:
	c->ifp->if_flags |= IFF_OACTIVE;
}

/*
 * Start output on the (slave) interface.  Get another datagram to send
 * off of the interface queue, and copy it to the interface
 * before starting the output.
 */
void cxsend (cx_chan_t *c)
{
	unsigned short port = c->chip->port;

	if (c->ifp->if_flags & IFF_DEBUG)
		print (("cx%d.%d: cxsend\n", c->board->num, c->num));

	/* No output if the interface is down. */
	if (! (c->ifp->if_flags & IFF_RUNNING))
		return;

	/* Set the current channel number. */
	outb (CAR(port), c->num & 3);

	/* Determine the buffer order. */
	if (inb (DMABSTS(port)) & DMABSTS_NTBUF) {
		cxput (c, 'B');
		cxput (c, 'A');
	} else {
		cxput (c, 'A');
		cxput (c, 'B');
	}

	/* Set up transmit timeout. */
	if (c->master->if_flags & IFF_OACTIVE)
		c->master->if_timer = TXTIMEOUT;

	/*
	 * Enable TXMPTY interrupt,
	 * to catch the case when the second buffer is empty.
	 */
	if ((inb (ATBSTS(port)) & BSTS_OWN24) &&
	    (inb (BTBSTS(port)) & BSTS_OWN24)) {
		outb (IER(port), IER_RXD | IER_TXD | IER_TXMPTY);
	} else
		outb (IER(port), IER_RXD | IER_TXD);
}

/*
 * Start output on the (master) interface and all slave interfaces.
 * Always called on splimp().
 */
void cxstart (struct ifnet *ifp)
{
	cx_chan_t *q, *c = cxchan[ifp->if_unit];

	if (c->ifp->if_flags & IFF_DEBUG)
		print (("cx%d.%d: cxstart\n", c->board->num, c->num));

	/* Start the master subchannel. */
	cxsend (c);

	/* Start all slave subchannels. */
	if (c->slaveq && ! sppp_isempty (c->master))
		for (q=c->slaveq; q; q=q->slaveq)
			if ((q->ifp->if_flags & IFF_RUNNING) &&
			    ! (q->ifp->if_flags & IFF_OACTIVE))
				cxsend (q);
}

/*
 * Handle transmit timeouts.
 * Recover after lost transmit interrupts.
 * Always called on splimp().
 */
void cxwatchdog (int unit)
{
	cx_chan_t *q, *c = cxchan[unit];

	if (! (c->ifp->if_flags & IFF_RUNNING))
		return;
	if (c->ifp->if_flags & IFF_DEBUG)
		printf ("cx%d.%d: device timeout\n", c->board->num, c->num);

	cxdown (c);
	for (q=c->slaveq; q; q=q->slaveq)
		cxdown (q);

	cxup (c);
	for (q=c->slaveq; q; q=q->slaveq)
		cxup (q);

		cxstart (c->ifp);
}

/*
 * Handle receive interrupts, including receive errors and
 * receive timeout interrupt.
 */
void cxrinth (cx_chan_t *c)
{
	unsigned short port = c->chip->port;
	unsigned short len, risr = inw (RISR(port));

	/* Receive errors. */
	if (risr & (RIS_BUSERR | RIS_OVERRUN | RISH_CRCERR | RISH_RXABORT)) {
		if (c->ifp->if_flags & IFF_DEBUG)
			printf ("cx%d.%d: receive error, risr=%b\n",
				c->board->num, c->num, risr, RISH_BITS);
		++c->ifp->if_ierrors;
		++c->stat->ierrs;
		if (risr & RIS_OVERRUN)
			++c->ifp->if_collisions;
	} else if (risr & RIS_EOBUF) {
		if (c->ifp->if_flags & IFF_DEBUG)
			print (("cx%d.%d: hdlc receive interrupt, risr=%b, arbsts=%b, brbsts=%b\n",
				c->board->num, c->num, risr, RISH_BITS,
				inb (ARBSTS(port)), BSTS_BITS,
				inb (BRBSTS(port)), BSTS_BITS));
		++c->stat->ipkts;

		/* Handle received data. */
		len = (risr & RIS_BB) ? inw(BRBCNT(port)) : inw(ARBCNT(port));
		c->stat->ibytes += len;
		if (len > DMABUFSZ) {
			/* Fatal error: actual DMA transfer size
			 * exceeds our buffer size.  It could be caused
			 * by incorrectly programmed DMA register or
			 * hardware fault.  Possibly, should panic here. */
			printf ("cx%d.%d: panic! DMA buffer overflow: %d bytes\n",
			       c->board->num, c->num, len);
			++c->ifp->if_ierrors;
		} else if (! (risr & RIS_EOFR)) {
			/* The received frame does not fit in the DMA buffer.
			 * It could be caused by serial lie noise,
			 * or if the peer has too big MTU. */
			if (c->ifp->if_flags & IFF_DEBUG)
				printf ("cx%d.%d: received frame length exceeds MTU, risr=%b\n",
					c->board->num, c->num, risr, RISH_BITS);
			++c->ifp->if_ierrors;
		} else {
			/* Valid frame received. */
			if (c->ifp->if_flags & IFF_DEBUG)
				print (("cx%d.%d: hdlc received %d bytes\n",
				c->board->num, c->num, len));
			cxinput (c, (risr & RIS_BB) ? c->brbuf : c->arbuf, len);
			++c->ifp->if_ipackets;
		}
	} else if (c->ifp->if_flags & IFF_DEBUG) {
		print (("cx%d.%d: unknown hdlc receive interrupt, risr=%b\n",
			c->board->num, c->num, risr, RISH_BITS));
		++c->stat->ierrs;
	}

	/* Restart receiver. */
	if (! (inb (ARBSTS(port)) & BSTS_OWN24)) {
		outw (ARBCNT(port), DMABUFSZ);
		outb (ARBSTS(port), BSTS_OWN24);
	}
	if (! (inb (BRBSTS(port)) & BSTS_OWN24)) {
		outw (BRBCNT(port), DMABUFSZ);
		outb (BRBSTS(port), BSTS_OWN24);
	}
}

/*
 * Handle transmit interrupt.
 */
int cxtinth (cx_chan_t *c)
{
	unsigned short port = c->chip->port;
	unsigned char tisr = inb (TISR(port));
	unsigned char teoir = 0;

	c->ifp->if_flags &= ~IFF_OACTIVE;
	if (c->ifp == c->master)
		c->ifp->if_timer = 0;

	if (tisr & (TIS_BUSERR | TIS_UNDERRUN)) {
		/* if (c->ifp->if_flags & IFF_DEBUG) */
			print (("cx%d.%d: transmit error, tisr=%b, atbsts=%b, btbsts=%b\n",
				c->board->num, c->num, tisr, TIS_BITS,
				inb (ATBSTS(port)), BSTS_BITS,
				inb (BTBSTS(port)), BSTS_BITS));
		++c->ifp->if_oerrors;
		++c->stat->oerrs;

		/* Terminate the failed buffer. */
		/* teoir = TEOI_TERMBUFF; */
	} else if (c->ifp->if_flags & IFF_DEBUG)
		print (("cx%d.%d: hdlc transmit interrupt, tisr=%b, atbsts=%b, btbsts=%b\n",
			c->board->num, c->num, tisr, TIS_BITS,
			inb (ATBSTS(port)), BSTS_BITS,
			inb (BTBSTS(port)), BSTS_BITS));

	if (tisr & TIS_EOFR) {
		++c->ifp->if_opackets;
		++c->stat->opkts;
	}

	/* Start output on the (sub-) channel. */
	cxsend (c);

	return (teoir);
}

#ifdef __FreeBSD__
void cxintr (int bnum)
{
	cx_board_t *b = cxboard + bnum;
#endif
#ifdef __bsdi__
void cxintr (cx_board_t *b)
{
#endif
	while (! (inw (BSR(b->port)) & BSR_NOINTR)) {
		/* Acknowledge the interrupt to enter the interrupt context. */
		/* Read the local interrupt vector register. */
		unsigned char livr = inb (IACK(b->port, BRD_INTR_LEVEL));
		cx_chan_t *c = b->chan + (livr>>2 & 0xf);
		unsigned short port = c->chip->port;
		unsigned short eoiport = REOIR(port);
		unsigned char eoi = 0;

		if (c->type == T_NONE) {
			printf ("cx%d.%d: unexpected interrupt, livr=0x%x\n",
				c->board->num, c->num, livr);
			continue;       /* incorrect channel number? */
		}
		/* print (("cx%d.%d: interrupt, livr=0x%x\n",
			c->board->num, c->num, livr)); */

		/* Clear RTS to stop receiver data flow while we are busy
		 * processing the interrupt, thus avoiding underruns. */
		if (! c->sopt.norts) {
			outb (MSVR_RTS(port), 0);
			c->rts = 0;
		}

		switch (livr & 3) {
		case LIV_EXCEP:         /* receive exception */
		case LIV_RXDATA:        /* receive interrupt */
			++c->stat->rintr;
			switch (c->mode) {
			case M_ASYNC: eoi = cxrinta (c); break;
			case M_HDLC:  cxrinth (c);       break;
			default:;       /* No bisync and X.21 yet */
			}
			break;
		case LIV_TXDATA:        /* transmit interrupt */
			++c->stat->tintr;
			eoiport = TEOIR(port);
			switch (c->mode) {
			case M_ASYNC: cxtinta (c);       break;
			case M_HDLC:  eoi = cxtinth (c); break;
			default:;       /* No bisync and X.21 yet */
			}
			break;
		case LIV_MODEM:         /* modem/timer interrupt */
			++c->stat->mintr;
			eoiport = MEOIR(port);
			cxmint (c);
			break;
		}

		/* Raise RTS for this channel if and only if
		 * both receive buffers are empty. */
		if (! c->sopt.norts && (inb (CSR(port)) & CSRA_RXEN) &&
		    (inb (ARBSTS(port)) & BSTS_OWN24) &&
		    (inb (BRBSTS(port)) & BSTS_OWN24)) {
			outb (MSVR_RTS(port), MSV_RTS);
			c->rts = 1;
		}

		/* Exit from interrupt context. */
		outb (eoiport, eoi);

		/* Master channel - start output on all idle subchannels. */
		if (c->master == c->ifp && c->slaveq &&
		    (livr & 3) == LIV_TXDATA && c->mode == M_HDLC &&
		    ! sppp_isempty (c->ifp)) {
			cx_chan_t *q;

			for (q=c->slaveq; q; q=q->slaveq)
				if ((q->ifp->if_flags & IFF_RUNNING) &&
				    ! (q->ifp->if_flags & IFF_OACTIVE))
					cxsend (q);
		}
	}
}

/*
 * Process the received packet.
 */
void cxinput (cx_chan_t *c, void *buf, unsigned len)
{
	/* Make an mbuf. */
	struct mbuf *m = makembuf (buf, len);
	if (! m) {
		if (c->ifp->if_flags & IFF_DEBUG)
			printf ("cx%d.%d: no memory for packet\n",
				c->board->num, c->num);
		++c->ifp->if_iqdrops;
		return;
	}
	m->m_pkthdr.rcvif = c->master;
#ifdef DEBUG
	if (c->ifp->if_flags & IFF_DEBUG)
	printmbuf (m);
#endif

#if NBPFILTER > 0
	/*
	 * Check if there's a BPF listener on this interface.
	 * If so, hand off the raw packet to bpf.
	 */
	if (c->bpf)
		bpf_tap (c->bpf, buf, len);
#endif

	/* Count the received bytes to the subchannel, not the master. */
	c->master->if_ibytes -= len + 3;
	c->ifp->if_ibytes += len + 3;

#ifdef __bsdi__
	if (c->sopt.ext) {
		struct p2pcom *p = (struct p2pcom*) c->master;
		(*p->p2p_input) (p, m);
	} else
#endif
	sppp_input (c->master, m);
}

void cxswitch (cx_chan_t *c, cx_soft_opt_t new)
{
#ifdef __bsdi__
	if (new.ext && ! c->sopt.ext) {
		/* Switch to external ppp implementation (BSDI) */
		sppp_detach (c->ifp);
		bzero ((void*) c->ifp + IFNETSZ, IFSTRUCTSZ-IFNETSZ);
	} else if (! new.ext && c->sopt.ext) {
		/* Switch to built-in ppp implementation */
		bzero ((void*) c->ifp + IFNETSZ, IFSTRUCTSZ-IFNETSZ);
		sppp_attach (c->ifp);
	}
#else
	new.ext = 0;
#endif
	if (! new.ext) {
		struct sppp *sp = (struct sppp*) c->ifp;

		if (new.cisco)
			sp->pp_flags |= PP_CISCO;
		else
			sp->pp_flags &= ~PP_CISCO;
		if (new.keepalive)
			sp->pp_flags |= PP_KEEPALIVE;
		else
			sp->pp_flags &= ~PP_KEEPALIVE;
	}
	c->sopt = new;
}
#endif /* NCX */