farsync.c

优龙2410linux2.6.8内核源代码

		spin_unlock_irqrestore(&card->card_lock, flags);
		schedule_timeout(1);
		spin_lock_irqsave(&card->card_lock, flags);

		if (++safety > 2000) {
			printk_err("Mailbox safety timeout\n");
			break;
		}

		mbval = FST_RDW(card, portMailbox[port->index][0]);
	}
	if (safety > 0) {
		dbg(DBG_CMD, "Mailbox clear after %d jiffies\n", safety);
	}
	if (mbval == NAK) {
		dbg(DBG_CMD, "issue_cmd: previous command was NAK'd\n");
	}

	FST_WRW(card, portMailbox[port->index][0], cmd);

	if (cmd == ABORTTX || cmd == STARTPORT) {
		port->txpos = 0;
		port->txipos = 0;
		port->start = 0;
	}

	spin_unlock_irqrestore(&card->card_lock, flags);
}

/*      Port output signals control
 */
static inline void
fst_op_raise(struct fst_port_info *port, unsigned int outputs)
{
	outputs |= FST_RDL(port->card, v24OpSts[port->index]);
	FST_WRL(port->card, v24OpSts[port->index], outputs);

	if (port->run)
		fst_issue_cmd(port, SETV24O);
}

static inline void
fst_op_lower(struct fst_port_info *port, unsigned int outputs)
{
	outputs = ~outputs & FST_RDL(port->card, v24OpSts[port->index]);
	FST_WRL(port->card, v24OpSts[port->index], outputs);

	if (port->run)
		fst_issue_cmd(port, SETV24O);
}

/*
 *      Setup port Rx buffers
 */
static void
fst_rx_config(struct fst_port_info *port)
{
	int i;
	int pi;
	unsigned int offset;
	unsigned long flags;
	struct fst_card_info *card;

	pi = port->index;
	card = port->card;
	spin_lock_irqsave(&card->card_lock, flags);
	for (i = 0; i < NUM_RX_BUFFER; i++) {
		offset = BUF_OFFSET(rxBuffer[pi][i][0]);

		FST_WRW(card, rxDescrRing[pi][i].ladr, (u16) offset);
		FST_WRB(card, rxDescrRing[pi][i].hadr, (u8) (offset >> 16));
		FST_WRW(card, rxDescrRing[pi][i].bcnt, cnv_bcnt(LEN_RX_BUFFER));
		FST_WRW(card, rxDescrRing[pi][i].mcnt, LEN_RX_BUFFER);
		FST_WRB(card, rxDescrRing[pi][i].bits, DMA_OWN);
	}
	port->rxpos = 0;
	spin_unlock_irqrestore(&card->card_lock, flags);
}

/*
 *      Setup port Tx buffers
 */
static void
fst_tx_config(struct fst_port_info *port)
{
	int i;
	int pi;
	unsigned int offset;
	unsigned long flags;
	struct fst_card_info *card;

	pi = port->index;
	card = port->card;
	spin_lock_irqsave(&card->card_lock, flags);
	for (i = 0; i < NUM_TX_BUFFER; i++) {
		offset = BUF_OFFSET(txBuffer[pi][i][0]);

		FST_WRW(card, txDescrRing[pi][i].ladr, (u16) offset);
		FST_WRB(card, txDescrRing[pi][i].hadr, (u8) (offset >> 16));
		FST_WRW(card, txDescrRing[pi][i].bcnt, 0);
		FST_WRB(card, txDescrRing[pi][i].bits, 0);
	}
	port->txpos = 0;
	port->txipos = 0;
	port->start = 0;
	spin_unlock_irqrestore(&card->card_lock, flags);
}

/*      TE1 Alarm change interrupt event
 */
static void
fst_intr_te1_alarm(struct fst_card_info *card, struct fst_port_info *port)
{
	u8 los;
	u8 rra;
	u8 ais;

	los = FST_RDB(card, suStatus.lossOfSignal);
	rra = FST_RDB(card, suStatus.receiveRemoteAlarm);
	ais = FST_RDB(card, suStatus.alarmIndicationSignal);

	if (los) {
		/*
		 * Lost the link
		 */
		if (netif_carrier_ok(port_to_dev(port))) {
			dbg(DBG_INTR, "Net carrier off\n");
			netif_carrier_off(port_to_dev(port));
		}
	} else {
		/*
		 * Link available
		 */
		if (!netif_carrier_ok(port_to_dev(port))) {
			dbg(DBG_INTR, "Net carrier on\n");
			netif_carrier_on(port_to_dev(port));
		}
	}

	if (los)
		dbg(DBG_INTR, "Assert LOS Alarm\n");
	else
		dbg(DBG_INTR, "De-assert LOS Alarm\n");
	if (rra)
		dbg(DBG_INTR, "Assert RRA Alarm\n");
	else
		dbg(DBG_INTR, "De-assert RRA Alarm\n");

	if (ais)
		dbg(DBG_INTR, "Assert AIS Alarm\n");
	else
		dbg(DBG_INTR, "De-assert AIS Alarm\n");
}

/*      Control signal change interrupt event
 */
static void
fst_intr_ctlchg(struct fst_card_info *card, struct fst_port_info *port)
{
	int signals;

	signals = FST_RDL(card, v24DebouncedSts[port->index]);

	if (signals & (((port->hwif == X21) || (port->hwif == X21D))
		       ? IPSTS_INDICATE : IPSTS_DCD)) {
		if (!netif_carrier_ok(port_to_dev(port))) {
			dbg(DBG_INTR, "DCD active\n");
			netif_carrier_on(port_to_dev(port));
		}
	} else {
		if (netif_carrier_ok(port_to_dev(port))) {
			dbg(DBG_INTR, "DCD lost\n");
			netif_carrier_off(port_to_dev(port));
		}
	}
}

/*      Log Rx Errors
 */
static void
fst_log_rx_error(struct fst_card_info *card, struct fst_port_info *port,
		 unsigned char dmabits, int rxp, unsigned short len)
{
	struct net_device *dev = port_to_dev(port);
	struct net_device_stats *stats = hdlc_stats(dev);

	/* 
	 * Increment the appropriate error counter
	 */
	stats->rx_errors++;
	if (dmabits & RX_OFLO) {
		stats->rx_fifo_errors++;
		dbg(DBG_ASS, "Rx fifo error on card %d port %d buffer %d\n",
		    card->card_no, port->index, rxp);
	}
	if (dmabits & RX_CRC) {
		stats->rx_crc_errors++;
		dbg(DBG_ASS, "Rx crc error on card %d port %d\n",
		    card->card_no, port->index);
	}
	if (dmabits & RX_FRAM) {
		stats->rx_frame_errors++;
		dbg(DBG_ASS, "Rx frame error on card %d port %d\n",
		    card->card_no, port->index);
	}
	if (dmabits == (RX_STP | RX_ENP)) {
		stats->rx_length_errors++;
		dbg(DBG_ASS, "Rx length error (%d) on card %d port %d\n",
		    len, card->card_no, port->index);
	}
}

/*      Rx Error Recovery
 */
static void
fst_recover_rx_error(struct fst_card_info *card, struct fst_port_info *port,
		     unsigned char dmabits, int rxp, unsigned short len)
{
	int i;
	int pi;

	pi = port->index;
	/* 
	 * Discard buffer descriptors until we see the start of the
	 * next frame.  Note that for long frames this could be in
	 * a subsequent interrupt. 
	 */
	i = 0;
	while ((dmabits & (DMA_OWN | RX_STP)) == 0) {
		FST_WRB(card, rxDescrRing[pi][rxp].bits, DMA_OWN);
		rxp = (rxp+1) % NUM_RX_BUFFER;
		if (++i > NUM_RX_BUFFER) {
			dbg(DBG_ASS, "intr_rx: Discarding more bufs"
			    " than we have\n");
			break;
		}
		dmabits = FST_RDB(card, rxDescrRing[pi][rxp].bits);
		dbg(DBG_ASS, "DMA Bits of next buffer was %x\n", dmabits);
	}
	dbg(DBG_ASS, "There were %d subsequent buffers in error\n", i);

	/* Discard the terminal buffer */
	if (!(dmabits & DMA_OWN)) {
		FST_WRB(card, rxDescrRing[pi][rxp].bits, DMA_OWN);
		rxp = (rxp+1) % NUM_RX_BUFFER;
	}
	port->rxpos = rxp;
	return;

}

/*      Rx complete interrupt
 */
static void
fst_intr_rx(struct fst_card_info *card, struct fst_port_info *port)
{
	unsigned char dmabits;
	int pi;
	int rxp;
	int rx_status;
	unsigned short len;
	struct sk_buff *skb;
	struct net_device *dev = port_to_dev(port);
	struct net_device_stats *stats = hdlc_stats(dev);

	/* Check we have a buffer to process */
	pi = port->index;
	rxp = port->rxpos;
	dmabits = FST_RDB(card, rxDescrRing[pi][rxp].bits);
	if (dmabits & DMA_OWN) {
		dbg(DBG_RX | DBG_INTR, "intr_rx: No buffer port %d pos %d\n",
		    pi, rxp);
		return;
	}
	if (card->dmarx_in_progress) {
		return;
	}

	/* Get buffer length */
	len = FST_RDW(card, rxDescrRing[pi][rxp].mcnt);
	/* Discard the CRC */
	len -= 2;
	if (len == 0) {
		/*
		 * This seems to happen on the TE1 interface sometimes
		 * so throw the frame away and log the event.
		 */
		printk_err("Frame received with 0 length. Card %d Port %d\n",
			   card->card_no, port->index);
		/* Return descriptor to card */
		FST_WRB(card, rxDescrRing[pi][rxp].bits, DMA_OWN);

		rxp = (rxp+1) % NUM_RX_BUFFER;
		port->rxpos = rxp;
		return;
	}

	/* Check buffer length and for other errors. We insist on one packet
	 * in one buffer. This simplifies things greatly and since we've
	 * allocated 8K it shouldn't be a real world limitation
	 */
	dbg(DBG_RX, "intr_rx: %d,%d: flags %x len %d\n", pi, rxp, dmabits, len);
	if (dmabits != (RX_STP | RX_ENP) || len > LEN_RX_BUFFER - 2) {
		fst_log_rx_error(card, port, dmabits, rxp, len);
		fst_recover_rx_error(card, port, dmabits, rxp, len);
		return;
	}

	/* Allocate SKB */
	if ((skb = dev_alloc_skb(len)) == NULL) {
		dbg(DBG_RX, "intr_rx: can't allocate buffer\n");

		stats->rx_dropped++;

		/* Return descriptor to card */
		FST_WRB(card, rxDescrRing[pi][rxp].bits, DMA_OWN);

		rxp = (rxp+1) % NUM_RX_BUFFER;
		port->rxpos = rxp;
		return;
	}

	/*
	 * We know the length we need to receive, len.
	 * It's not worth using the DMA for reads of less than
	 * FST_MIN_DMA_LEN
	 */

	if ((len < FST_MIN_DMA_LEN) || (card->family == FST_FAMILY_TXP)) {
		memcpy_fromio(skb_put(skb, len),
			      card->mem + BUF_OFFSET(rxBuffer[pi][rxp][0]),
			      len);

		/* Reset buffer descriptor */
		FST_WRB(card, rxDescrRing[pi][rxp].bits, DMA_OWN);

		/* Update stats */
		stats->rx_packets++;
		stats->rx_bytes += len;

		/* Push upstream */
		dbg(DBG_RX, "Pushing frame up the stack\n");
		skb->mac.raw = skb->data;
		skb->dev = dev;
		if (port->mode == FST_RAW) {
			/*
			 * Mark it for our own raw sockets interface
			 */
			skb->protocol = htons(ETH_P_CUST);
			skb->pkt_type = PACKET_HOST;
		} else {
			skb->protocol = hdlc_type_trans(skb, skb->dev);
		}
		rx_status = netif_rx(skb);
		fst_process_rx_status(rx_status, port_to_dev(port)->name);
		if (rx_status == NET_RX_DROP) {
			stats->rx_dropped++;
		}
		dev->last_rx = jiffies;
	} else {
		card->dma_skb_rx = skb;
		card->dma_port_rx = port;
		card->dma_len_rx = len;
		card->dma_rxpos = rxp;
		fst_rx_dma(card, (char *) card->rx_dma_handle_card,
			   (char *) BUF_OFFSET(rxBuffer[pi][rxp][0]), len);
	}
	if (rxp != port->rxpos) {
		dbg(DBG_ASS, "About to increment rxpos by more than 1\n");
		dbg(DBG_ASS, "rxp = %d rxpos = %d\n", rxp, port->rxpos);
	}
	rxp = (rxp+1) % NUM_RX_BUFFER;
	port->rxpos = rxp;
}

/*
 *      The bottom halfs to the ISR
 *
 */

static void
do_bottom_half_tx(struct fst_card_info *card)
{
	struct fst_port_info *port;
	int pi;
	int txq_length;
	struct sk_buff *skb;
	unsigned long flags;
	struct net_device *dev;
	struct net_device_stats *stats;

	/*
	 *  Find a free buffer for the transmit
	 *  Step through each port on this card
	 */

	dbg(DBG_TX, "do_bottom_half_tx\n");
	for (pi = 0, port = card->ports; pi < card->nports; pi++, port++) {
		if (!port->run)
			continue;

                dev = port_to_dev(port);
                stats = hdlc_stats(dev);
		while (!
		       (FST_RDB(card, txDescrRing[pi][port->txpos].bits) &
			DMA_OWN)
                       && !(card->dmatx_in_progress)) {
			/*
			 * There doesn't seem to be a txdone event per-se
			 * We seem to have to deduce it, by checking the DMA_OWN
			 * bit on the next buffer we think we can use
			 */
			spin_lock_irqsave(&card->card_lock, flags);
			if ((txq_length = port->txqe - port->txqs) < 0) {
				/*
				 * This is the case where one has wrapped and the
				 * maths gives us a negative number
				 */
				txq_length = txq_length + FST_TXQ_DEPTH;
			}
			spin_unlock_irqrestore(&card->card_lock, flags);
			if (txq_length > 0) {
				/*
				 * There is something to send
				 */
				spin_lock_irqsave(&card->card_lock, flags);
				skb = port->txq[port->txqs];
				port->txqs++;
				if (port->txqs == FST_TXQ_DEPTH) {
					port->txqs = 0;
				}
				spin_unlock_irqrestore(&card->card_lock, flags);
				/*
				 * copy the data and set the required indicators on the
				 * card.
				 */
				FST_WRW(card, txDescrRing[pi][port->txpos].bcnt,
					cnv_bcnt(skb->len));
				if ((skb->len < FST_MIN_DMA_LEN)
				    || (card->family == FST_FAMILY_TXP)) {
					/* Enqueue the packet with normal io */
					memcpy_toio(card->mem +
						    BUF_OFFSET(txBuffer[pi]
							       [port->
								txpos][0]),
						    skb->data, skb->len);
					FST_WRB(card,
						txDescrRing[pi][port->txpos].
						bits,
						DMA_OWN | TX_STP | TX_ENP);
					stats->tx_packets++;
					stats->tx_bytes += skb->len;
					dev->trans_start = jiffies;
				} else {
					/* Or do it through dma */
					memcpy(card->tx_dma_handle_host,
					       skb->data, skb->len);
					card->dma_port_tx = port;
					card->dma_len_tx = skb->len;
					card->dma_txpos = port->txpos;
					fst_tx_dma(card,
						   (char *) card->
						   tx_dma_handle_card,
						   (char *)
						   BUF_OFFSET(txBuffer[pi]
							      [port->txpos][0]),
						   skb->len);
				}
				if (++port->txpos >= NUM_TX_BUFFER)
					port->txpos = 0;
				/*
				 * If we have flow control on, can we now release it?
				 */
				if (port->start) {
					if (txq_length < fst_txq_low) {
						netif_wake_queue(port_to_dev
								 (port));
						port->start = 0;
					}
				}
				dev_kfree_skb(skb);
			} else {
				/*
				 * Nothing to send so break out of the while loop
				 */
				break;
			}
		}