via-rhine.c

Linux下各种网卡的驱动程序

	/* For ESI phys, turn on bit 7 in register 0x17. */
	mdio_write(dev, np->phys[0], 0x17, mdio_read(dev, np->phys[0], 0x17) |
			   (np->drv_flags & HasESIPhy) ? 0x0080 : 0x0001);

	if (np->msg_level & NETIF_MSG_IFUP)
		printk(KERN_DEBUG "%s: Done netdev_open(), status %4.4x "
			   "MII status: %4.4x.\n",
			   dev->name, readw(ioaddr + ChipCmd),
			   mdio_read(dev, np->phys[0], 1));

	/* Set the timer to check for link beat. */
	init_timer(&np->timer);
	np->timer.expires = jiffies + 2;
	np->timer.data = (unsigned long)dev;
	np->timer.function = &netdev_timer;				/* timer handler */
	add_timer(&np->timer);

	return 0;
}

static void check_duplex(struct net_device *dev)
{
	struct netdev_private *np = (struct netdev_private *)dev->priv;
	long ioaddr = dev->base_addr;
	int mii_reg5 = mdio_read(dev, np->phys[0], 5);
	int negotiated = mii_reg5 & np->advertising;
	int duplex;

	if (np->duplex_lock  ||  mii_reg5 == 0xffff)
		return;
	duplex = (negotiated & 0x0100) || (negotiated & 0x01C0) == 0x0040;
	if (np->full_duplex != duplex) {
		np->full_duplex = duplex;
		if (np->msg_level & NETIF_MSG_LINK)
			printk(KERN_INFO "%s: Setting %s-duplex based on MII #%d link"
				   " partner capability of %4.4x.\n", dev->name,
				   duplex ? "full" : "half", np->phys[0], mii_reg5);
		if (duplex)
			np->chip_cmd |= CmdFDuplex;
		else
			np->chip_cmd &= ~CmdFDuplex;
		writew(np->chip_cmd, ioaddr + ChipCmd);
	}
}

static void netdev_timer(unsigned long data)
{
	struct net_device *dev = (struct net_device *)data;
	struct netdev_private *np = (struct netdev_private *)dev->priv;
	long ioaddr = dev->base_addr;
	int next_tick = 10*HZ;

	if (np->msg_level & NETIF_MSG_TIMER) {
		printk(KERN_DEBUG "%s: VIA Rhine monitor tick, status %4.4x.\n",
			   dev->name, readw(ioaddr + IntrStatus));
	}
	if (netif_queue_paused(dev)
		&& np->cur_tx - np->dirty_tx > 1
		&& jiffies - dev->trans_start > TX_TIMEOUT)
		tx_timeout(dev);

	check_duplex(dev);

	np->timer.expires = jiffies + next_tick;
	add_timer(&np->timer);
}

static void tx_timeout(struct net_device *dev)
{
	struct netdev_private *np = (struct netdev_private *)dev->priv;
	long ioaddr = dev->base_addr;

	printk(KERN_WARNING "%s: Transmit timed out, status %4.4x, PHY status "
		   "%4.4x, resetting...\n",
		   dev->name, readw(ioaddr + IntrStatus),
		   mdio_read(dev, np->phys[0], 1));

	/* Perhaps we should reinitialize the hardware here. */
	dev->if_port = 0;
	/* Restart the chip's Tx processes . */
	writel(virt_to_bus(np->tx_ring + (np->dirty_tx % TX_RING_SIZE)),
		   ioaddr + TxRingPtr);
	writew(CmdTxDemand | np->chip_cmd, dev->base_addr + ChipCmd);

	/* Trigger an immediate transmit demand. */

	dev->trans_start = jiffies;
	np->stats.tx_errors++;
	return;
}


/* Initialize the Rx and Tx rings, along with various 'dev' bits. */
static void init_ring(struct net_device *dev)
{
	struct netdev_private *np = (struct netdev_private *)dev->priv;
	int i;

	np->tx_full = 0;
	np->cur_rx = np->cur_tx = 0;
	np->dirty_rx = np->dirty_tx = 0;

	/* Use 1518/+18 if the CRC is transferred. */
	np->rx_buf_sz = dev->mtu + 14;
	if (np->rx_buf_sz < PKT_BUF_SZ)
		np->rx_buf_sz = PKT_BUF_SZ;
	np->rx_head_desc = &np->rx_ring[0];

	for (i = 0; i < RX_RING_SIZE; i++) {
		np->rx_ring[i].rx_status = 0;
		np->rx_ring[i].desc_length = cpu_to_le32(np->rx_buf_sz);
		np->rx_ring[i].next_desc = virt_to_le32desc(&np->rx_ring[i+1]);
		np->rx_skbuff[i] = 0;
	}
	/* Mark the last entry as wrapping the ring. */
	np->rx_ring[i-1].next_desc = virt_to_le32desc(&np->rx_ring[0]);

	/* Fill in the Rx buffers.  Handle allocation failure gracefully. */
	for (i = 0; i < RX_RING_SIZE; i++) {
		struct sk_buff *skb = dev_alloc_skb(np->rx_buf_sz);
		np->rx_skbuff[i] = skb;
		if (skb == NULL)
			break;
		skb->dev = dev;			/* Mark as being used by this device. */
		np->rx_ring[i].addr = virt_to_le32desc(skb->tail);
		np->rx_ring[i].rx_status = cpu_to_le32(DescOwn);
	}
	np->dirty_rx = (unsigned int)(i - RX_RING_SIZE);

	for (i = 0; i < TX_RING_SIZE; i++) {
		np->tx_skbuff[i] = 0;
		np->tx_ring[i].tx_status = 0;
		np->tx_ring[i].desc_length = cpu_to_le32(0x00e08000);
		np->tx_ring[i].next_desc = virt_to_le32desc(&np->tx_ring[i+1]);
		np->tx_buf[i] = 0;		/* Allocated as/if needed. */
	}
	np->tx_ring[i-1].next_desc = virt_to_le32desc(&np->tx_ring[0]);

	return;
}

static int start_tx(struct sk_buff *skb, struct net_device *dev)
{
	struct netdev_private *np = (struct netdev_private *)dev->priv;
	unsigned entry;

	/* Block a timer-based transmit from overlapping.  This happens when
	   packets are presumed lost, and we use this check the Tx status. */
	if (netif_pause_tx_queue(dev) != 0) {
		/* This watchdog code is redundant with the media monitor timer. */
		if (jiffies - dev->trans_start > TX_TIMEOUT)
			tx_timeout(dev);
		return 1;
	}

	/* Caution: the write order is important here, set the descriptor word
	   with the "ownership" bit last.  No SMP locking is needed if the
	   cur_tx is incremented after the descriptor is consistent.  */

	/* Calculate the next Tx descriptor entry. */
	entry = np->cur_tx % TX_RING_SIZE;

	np->tx_skbuff[entry] = skb;

	if ((np->drv_flags & ReqTxAlign)  && ((long)skb->data & 3)) {
		/* Must use alignment buffer. */
		if (np->tx_buf[entry] == NULL &&
			(np->tx_buf[entry] = kmalloc(PKT_BUF_SZ, GFP_KERNEL)) == NULL)
			return 1;
		memcpy(np->tx_buf[entry], skb->data, skb->len);
		np->tx_ring[entry].addr = virt_to_le32desc(np->tx_buf[entry]);
	} else
		np->tx_ring[entry].addr = virt_to_le32desc(skb->data);
	/* Explicitly flush packet data cache lines here. */

	np->tx_ring[entry].desc_length =
		cpu_to_le32(0x00E08000 | (skb->len >= ETH_ZLEN ? skb->len : ETH_ZLEN));
	np->tx_ring[entry].tx_status = cpu_to_le32(DescOwn);

	np->cur_tx++;

	/* Explicitly flush descriptor cache lines here. */

	/* Wake the potentially-idle transmit channel. */
	writew(CmdTxDemand | np->chip_cmd, dev->base_addr + ChipCmd);

	if (np->cur_tx - np->dirty_tx >= TX_QUEUE_LEN - 1) {
		np->tx_full = 1;
		/* Check for a just-cleared queue. */
		if (np->cur_tx - (volatile unsigned int)np->dirty_tx
			< TX_QUEUE_LEN - 2) {
			np->tx_full = 0;
			netif_unpause_tx_queue(dev);
		} else
			netif_stop_tx_queue(dev);
	} else
		netif_unpause_tx_queue(dev);		/* Typical path */

	dev->trans_start = jiffies;

	if (np->msg_level & NETIF_MSG_TX_QUEUED) {
		printk(KERN_DEBUG "%s: Transmit frame #%d queued in slot %d.\n",
			   dev->name, np->cur_tx, entry);
	}
	return 0;
}

/* The interrupt handler does all of the Rx thread work and cleans up
   after the Tx thread. */
static void intr_handler(int irq, void *dev_instance, struct pt_regs *rgs)
{
	struct net_device *dev = (struct net_device *)dev_instance;
	struct netdev_private *np = (void *)dev->priv;
	long ioaddr = dev->base_addr;
	int boguscnt = np->max_interrupt_work;

	do {
		u32 intr_status = readw(ioaddr + IntrStatus);

		/* Acknowledge all of the current interrupt sources ASAP. */
		writew(intr_status & 0xffff, ioaddr + IntrStatus);

		if (np->msg_level & NETIF_MSG_INTR)
			printk(KERN_DEBUG "%s: Interrupt, status %4.4x.\n",
				   dev->name, intr_status);

		if (intr_status == 0)
			break;

		if (intr_status & (IntrRxDone | IntrRxErr | IntrRxDropped |
						   IntrRxWakeUp | IntrRxEmpty | IntrRxNoBuf))
			netdev_rx(dev);

		for (; np->cur_tx - np->dirty_tx > 0; np->dirty_tx++) {
			int entry = np->dirty_tx % TX_RING_SIZE;
			int txstatus = le32_to_cpu(np->tx_ring[entry].tx_status);
			if (txstatus & DescOwn)
				break;
			if (np->msg_level & NETIF_MSG_TX_DONE)
				printk(KERN_DEBUG "  Tx scavenge %d status %4.4x.\n",
					   entry, txstatus);
			if (txstatus & 0x8000) {
				if (np->msg_level & NETIF_MSG_TX_ERR)
					printk(KERN_DEBUG "%s: Transmit error, Tx status %4.4x.\n",
						   dev->name, txstatus);
				np->stats.tx_errors++;
				if (txstatus & 0x0400) np->stats.tx_carrier_errors++;
				if (txstatus & 0x0200) np->stats.tx_window_errors++;
				if (txstatus & 0x0100) np->stats.tx_aborted_errors++;
				if (txstatus & 0x0080) np->stats.tx_heartbeat_errors++;
				if (txstatus & 0x0002) np->stats.tx_fifo_errors++;
#ifdef ETHER_STATS
				if (txstatus & 0x0100) np->stats.collisions16++;
#endif
				/* Transmitter restarted in 'abnormal' handler. */
			} else {
#ifdef ETHER_STATS
				if (txstatus & 0x0001) np->stats.tx_deferred++;
#endif
				if (np->drv_flags & HasV1TxStat)
					np->stats.collisions += (txstatus >> 3) & 15;
				else
					np->stats.collisions += txstatus & 15;
#if defined(NETSTATS_VER2)
				np->stats.tx_bytes += np->tx_skbuff[entry]->len;
#endif
				np->stats.tx_packets++;
			}
			/* Free the original skb. */
			dev_free_skb_irq(np->tx_skbuff[entry]);
			np->tx_skbuff[entry] = 0;
		}
		/* Note the 4 slot hysteresis in mark the queue non-full. */
		if (np->tx_full  &&  np->cur_tx - np->dirty_tx < TX_QUEUE_LEN - 4) {
			/* The ring is no longer full, allow new TX entries. */
			np->tx_full = 0;
			netif_resume_tx_queue(dev);
		}

		/* Abnormal error summary/uncommon events handlers. */
		if (intr_status & (IntrPCIErr | IntrLinkChange | IntrMIIChange |
						   IntrStatsMax | IntrTxAbort | IntrTxUnderrun))
			netdev_error(dev, intr_status);

		if (--boguscnt < 0) {
			printk(KERN_WARNING "%s: Too much work at interrupt, "
				   "status=0x%4.4x.\n",
				   dev->name, intr_status);
			break;
		}
	} while (1);

	if (np->msg_level & NETIF_MSG_INTR)
		printk(KERN_DEBUG "%s: exiting interrupt, status=%#4.4x.\n",
			   dev->name, (int)readw(ioaddr + IntrStatus));

	return;
}

/* This routine is logically part of the interrupt handler, but isolated
   for clarity and better register allocation. */
static int netdev_rx(struct net_device *dev)
{
	struct netdev_private *np = (struct netdev_private *)dev->priv;
	int entry = np->cur_rx % RX_RING_SIZE;
	int boguscnt = np->dirty_rx + RX_RING_SIZE - np->cur_rx;

	if (np->msg_level & NETIF_MSG_RX_STATUS) {
		printk(KERN_DEBUG " In netdev_rx(), entry %d status %8.8x.\n",
			   entry, np->rx_head_desc->rx_status);
	}

	/* If EOP is set on the next entry, it's a new packet. Send it up. */
	while ( ! (np->rx_head_desc->rx_status & cpu_to_le32(DescOwn))) {
		struct rx_desc *desc = np->rx_head_desc;
		u32 desc_status = le32_to_cpu(desc->rx_status);
		int data_size = desc_status >> 16;

		if (np->msg_level & NETIF_MSG_RX_STATUS)
			printk(KERN_DEBUG "  netdev_rx() status is %4.4x.\n",
				   desc_status);
		if (--boguscnt < 0)
			break;
		if ( (desc_status & (RxWholePkt | RxErr)) !=  RxWholePkt) {
			if ((desc_status & RxWholePkt) !=  RxWholePkt) {
				printk(KERN_WARNING "%s: Oversized Ethernet frame spanned "
					   "multiple buffers, entry %#x length %d status %4.4x!\n",
					   dev->name, np->cur_rx, data_size, desc_status);
				printk(KERN_WARNING "%s: Oversized Ethernet frame %p vs %p.\n",
					   dev->name, np->rx_head_desc,
					   &np->rx_ring[np->cur_rx % RX_RING_SIZE]);
				np->stats.rx_length_errors++;
			} else if (desc_status & RxErr) {
				/* There was a error. */
				if (np->msg_level & NETIF_MSG_RX_ERR)
					printk(KERN_DEBUG "  netdev_rx() Rx error was %8.8x.\n",
						   desc_status);
				np->stats.rx_errors++;
				if (desc_status & 0x0030) np->stats.rx_length_errors++;
				if (desc_status & 0x0048) np->stats.rx_fifo_errors++;
				if (desc_status & 0x0004) np->stats.rx_frame_errors++;
				if (desc_status & 0x0002) np->stats.rx_crc_errors++;
			}
		} else {
			struct sk_buff *skb;
			/* Length should omit the CRC */
			int pkt_len = data_size - 4;

			/* Check if the packet is long enough to accept without copying
			   to a minimally-sized skbuff. */
			if (pkt_len < np->rx_copybreak
				&& (skb = dev_alloc_skb(pkt_len + 2)) != NULL) {
				skb->dev = dev;
				skb_reserve(skb, 2);	/* 16 byte align the IP header */
#if HAS_IP_COPYSUM			/* Call copy + cksum if available. */
				eth_copy_and_sum(skb, np->rx_skbuff[entry]->tail, pkt_len, 0);
				skb_put(skb, pkt_len);