sundance.c

Linux下各种网卡的驱动程序

	/* Station address must be written as 16 bit words with the Kendin chip. */
	for (i = 0; i < 6; i += 2)
		writew((dev->dev_addr[i + 1] << 8) + dev->dev_addr[i],
			   ioaddr + StationAddr + i);

	np->link_status = readb(ioaddr + MIICtrl) & 0xE0;
	writew((np->full_duplex || (np->link_status & 0x20)) ? 0x120 : 0,
		   ioaddr + MACCtrl0);
	writew(dev->mtu + 14, ioaddr + MaxFrameSize);
	if (dev->mtu > 2047)
		writel(readl(ioaddr + ASICCtrl) | 0x0C, ioaddr + ASICCtrl);

	set_rx_mode(dev);
	writew(0, ioaddr + DownCounter);
	/* Set the chip to poll every N*320nsec. */
	writeb(100, ioaddr + RxDescPoll);
	writeb(127, ioaddr + TxDescPoll);
#if 0
	if (np->drv_flags & KendinPktDropBug)
		writeb(0x01, ioaddr + DebugCtrl1);
#endif

	/* Enable interrupts by setting the interrupt mask. */
	writew(IntrRxDMADone | IntrPCIErr | IntrDrvRqst | IntrTxDone
		   | StatsMax | LinkChange, ioaddr + IntrEnable);
	writew(StatsEnable | RxEnable | TxEnable, ioaddr + MACCtrl1);
}

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 "
				   "negotiated capability %4.4x.\n", dev->name,
				   duplex ? "full" : "half", np->phys[0], negotiated);
		writew(duplex ? 0x20 : 0, ioaddr + MACCtrl0);
	}
}

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: Media selection timer tick, intr status %4.4x, "
			   "Tx %x Rx %x.\n",
			   dev->name, (int)readw(ioaddr + IntrEnable),
			   (int)readw(ioaddr + TxStatus), (int)readl(ioaddr + RxStatus));
	}
	/* Note: This does not catch a 0 or 1 element stuck queue. */
	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,"
		   " resetting...\n", dev->name, (int)readw(ioaddr + TxStatus));

#ifdef __i386__
	if (np->msg_level & NETIF_MSG_TX_ERR) {
		int i;
		printk(KERN_DEBUG "  Rx ring %8.8x: ", (int)np->rx_ring);
		for (i = 0; i < RX_RING_SIZE; i++)
			printk(" %8.8x", (unsigned int)np->rx_ring[i].status);
		printk("\n"KERN_DEBUG"  Tx ring %8.8x: ", (int)np->tx_ring);
		for (i = 0; i < TX_RING_SIZE; i++)
			printk(" %8.8x", np->tx_ring[i].status);
		printk("\n");
	}
#endif

	/* Perhaps we should reinitialize the hardware here. */
	dev->if_port = 0;
	/* Stop and restart the chip's Tx processes . */

	/* Trigger an immediate transmit demand. */
	writew(IntrRxDMADone | IntrPCIErr | IntrDrvRqst | IntrTxDone
		   | StatsMax | LinkChange, ioaddr + IntrEnable);

	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;

	np->rx_buf_sz = dev->mtu + 20;
	if (np->rx_buf_sz < PKT_BUF_SZ)
		np->rx_buf_sz = PKT_BUF_SZ;
	np->rx_head_desc = &np->rx_ring[0];

	/* Initialize all Rx descriptors. */
	for (i = 0; i < RX_RING_SIZE; i++) {
		np->rx_ring[i].next_desc = virt_to_le32desc(&np->rx_ring[i+1]);
		np->rx_ring[i].status = 0;
		np->rx_ring[i].frag[0].length = 0;
		np->rx_skbuff[i] = 0;
	}
	/* Wrap 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. */
		skb_reserve(skb, 2);	/* 16 byte align the IP header. */
		np->rx_ring[i].frag[0].addr = virt_to_le32desc(skb->tail);
		np->rx_ring[i].frag[0].length = cpu_to_le32(np->rx_buf_sz | LastFrag);
	}
	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].status = 0;
	}
	return;
}

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

	/* Block a timer-based transmit from overlapping. */
	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;
	}

	/* Note: Ordering is important here, set the field with the
	   "ownership" bit last, and only then increment cur_tx. */

	/* Calculate the next Tx descriptor entry. */
	entry = np->cur_tx % TX_RING_SIZE;
	np->tx_skbuff[entry] = skb;
	txdesc = &np->tx_ring[entry];

	txdesc->next_desc = 0;
	/* Note: disable the interrupt generation here before releasing. */
	txdesc->status =
		cpu_to_le32((entry<<2) | DescIntrOnDMADone | DescIntrOnTx | 1);
	txdesc->frag[0].addr = virt_to_le32desc(skb->data);
	txdesc->frag[0].length = cpu_to_le32(skb->len | LastFrag);
	if (np->last_tx)
		np->last_tx->next_desc = virt_to_le32desc(txdesc);
	np->last_tx = txdesc;
	np->cur_tx++;

	/* On some architectures: explicitly flush cache lines here. */

	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 */

	/* Side effect: The read wakes the potentially-idle transmit channel. */
	if (readl(dev->base_addr + TxListPtr) == 0)
		writel(virt_to_bus(&np->tx_ring[entry]), dev->base_addr + TxListPtr);

	dev->trans_start = jiffies;

	if (np->msg_level & NETIF_MSG_TX_QUEUED) {
		printk(KERN_DEBUG "%s: Transmit frame #%d len %d queued in slot %d.\n",
			   dev->name, np->cur_tx, skb->len, 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;
	long ioaddr;
	int boguscnt;

	ioaddr = dev->base_addr;
	np = (struct netdev_private *)dev->priv;
	boguscnt = np->max_interrupt_work;

	do {
		int intr_status = readw(ioaddr + IntrStatus);
		if ((intr_status & ~IntrRxDone) == 0 || intr_status == 0xffff)
			break;

		writew(intr_status & (IntrRxDMADone | IntrPCIErr |
							  IntrDrvRqst |IntrTxDone|IntrTxDMADone |
							  StatsMax | LinkChange),
							  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 & IntrRxDMADone)
			netdev_rx(dev);

		if (intr_status & IntrTxDone) {
			int txboguscnt = 32;
			int tx_status = readw(ioaddr + TxStatus);
			while (tx_status & 0x80) {
				if (np->msg_level & NETIF_MSG_TX_DONE)
					printk("%s: Transmit status is %4.4x.\n",
						   dev->name, tx_status);
				if (tx_status & 0x1e) {
					if (np->msg_level & NETIF_MSG_TX_ERR)
						printk("%s: Transmit error status %4.4x.\n",
							   dev->name, tx_status);
					np->stats.tx_errors++;
					if (tx_status & 0x10)  np->stats.tx_fifo_errors++;
#ifdef ETHER_STATS
					if (tx_status & 0x08)  np->stats.collisions16++;
#else
					if (tx_status & 0x08)  np->stats.collisions++;
#endif
					if (tx_status & 0x04)  np->stats.tx_fifo_errors++;
					if (tx_status & 0x02)  np->stats.tx_window_errors++;
					/* This reset has not been verified!. */
					if (tx_status & 0x10) {			/* Reset the Tx. */
						writel(0x001c0000 | readl(ioaddr + ASICCtrl),
							   ioaddr + ASICCtrl);
#if 0					/* Do we need to reset the Tx pointer here? */
						writel(virt_to_bus(&np->tx_ring[np->dirty_tx]),
							   dev->base_addr + TxListPtr);
#endif
					}
					if (tx_status & 0x1e) 		/* Restart the Tx. */
						writew(TxEnable, ioaddr + MACCtrl1);
				}
				/* Yup, this is a documentation bug.  It cost me *hours*. */
				writew(0, ioaddr + TxStatus);
				if (--txboguscnt < 0)
					break;
				tx_status = readw(ioaddr + TxStatus);
			}
		}
		for (; np->cur_tx - np->dirty_tx > 0; np->dirty_tx++) {
			int entry = np->dirty_tx % TX_RING_SIZE;
			if ( ! (np->tx_ring[entry].status & cpu_to_le32(DescTxDMADone)))
				break;
			/* Free the original skb. */
			dev_free_skb_irq(np->tx_skbuff[entry]);
			np->tx_skbuff[entry] = 0;
		}
		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 & (IntrDrvRqst | IntrPCIErr | LinkChange | StatsMax))
			netdev_error(dev, intr_status);

		if (--boguscnt < 0) {
			int intr_clear = readw(ioaddr + IntrClear);
			get_stats(dev);
			printk(KERN_WARNING "%s: Too much work at interrupt, "
				   "status=0x%4.4x / 0x%4.4x .. 0x%4.4x.\n",
				   dev->name, intr_status, intr_clear,
				   (int)readw(ioaddr + IntrClear));
			/* Re-enable us in 3.2msec. */
			writew(1000, ioaddr + DownCounter);
			writew(IntrDrvRqst, ioaddr + IntrEnable);
			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 separated
   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 %4.4x.\n",
			   entry, np->rx_ring[entry].status);
	}

	/* If EOP is set on the next entry, it's a new packet. Send it up. */
	while (np->rx_head_desc->status & cpu_to_le32(DescOwn)) {
		struct netdev_desc *desc = np->rx_head_desc;
		u32 frame_status = le32_to_cpu(desc->status);
		int pkt_len = frame_status & 0x1fff;		/* Chip omits the CRC. */

		if (np->msg_level & NETIF_MSG_RX_STATUS)
			printk(KERN_DEBUG "  netdev_rx() status was %8.8x.\n",
				   frame_status);
		if (--boguscnt < 0)
			break;
		if (frame_status & 0x001f4000) {
			/* There was a error. */
			if (np->msg_level & NETIF_MSG_RX_ERR)
				printk(KERN_DEBUG "  netdev_rx() Rx error was %8.8x.\n",
					   frame_status);
			np->stats.rx_errors++;
			if (frame_status & 0x00100000) np->stats.rx_length_errors++;
			if (frame_status & 0x00010000) np->stats.rx_fifo_errors++;
			if (frame_status & 0x00060000) np->stats.rx_frame_errors++;
			if (frame_status & 0x00080000) np->stats.rx_crc_errors++;
			if (frame_status & 0x00100000) {
				printk(KERN_WARNING "%s: Oversized Ethernet frame,"
					   " status %8.8x.\n",
					   dev->name, frame_status);
			}
		} else {
			struct sk_buff *skb;

#ifndef final_version
			if (np->msg_level & NETIF_MSG_RX_STATUS)
				printk(KERN_DEBUG "  netdev_rx() normal Rx pkt length %d"
					   ", bogus_cnt %d.\n",
					   pkt_len, boguscnt);
#endif
			/* 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 */
				eth_copy_and_sum(skb, np->rx_skbuff[entry]->tail, pkt_len, 0);
				skb_put(skb, pkt_len);
			} else {
				skb_put(skb = np->rx_skbuff[entry], pkt_len);
				np->rx_skbuff[entry] = NULL;
			}
			skb->protocol = eth_type_trans(skb, dev);
			/* Note: checksum -> skb->ip_summed = CHECKSUM_UNNECESSARY; */
			netif_rx(skb);
			dev->last_rx = jiffies;
		}
		entry = (++np->cur_rx) % RX_RING_SIZE;
		np->rx_head_desc = &np->rx_ring[entry];
	}