meth.c

来自「linux 内核源代码」· C语言 代码 · 共 858 行 · 第 1/2 页

		} else {
			dev->stats.rx_errors++;
			skb=priv->rx_skbs[priv->rx_write];
#if MFE_DEBUG>0
			printk(KERN_WARNING "meth: RX error: status=0x%016lx\n",status);
			if(status&METH_RX_ST_RCV_CODE_VIOLATION)
				printk(KERN_WARNING "Receive Code Violation\n");
			if(status&METH_RX_ST_CRC_ERR)
				printk(KERN_WARNING "CRC error\n");
			if(status&METH_RX_ST_INV_PREAMBLE_CTX)
				printk(KERN_WARNING "Invalid Preamble Context\n");
			if(status&METH_RX_ST_LONG_EVT_SEEN)
				printk(KERN_WARNING "Long Event Seen...\n");
			if(status&METH_RX_ST_BAD_PACKET)
				printk(KERN_WARNING "Bad Packet\n");
			if(status&METH_RX_ST_CARRIER_EVT_SEEN)
				printk(KERN_WARNING "Carrier Event Seen\n");
#endif
		}
		priv->rx_ring[priv->rx_write] = (rx_packet*)skb->head;
		priv->rx_ring[priv->rx_write]->status.raw = 0;
		priv->rx_ring_dmas[priv->rx_write] =
			dma_map_single(NULL, priv->rx_ring[priv->rx_write],
				       METH_RX_BUFF_SIZE, DMA_FROM_DEVICE);
		mace->eth.rx_fifo = priv->rx_ring_dmas[priv->rx_write];
		ADVANCE_RX_PTR(priv->rx_write);
	}
	spin_lock(&priv->meth_lock);
	/* In case there was underflow, and Rx DMA was disabled */
	priv->dma_ctrl |= METH_DMA_RX_INT_EN | METH_DMA_RX_EN;
	mace->eth.dma_ctrl = priv->dma_ctrl;
	mace->eth.int_stat = METH_INT_RX_THRESHOLD;
	spin_unlock(&priv->meth_lock);
}

static int meth_tx_full(struct net_device *dev)
{
	struct meth_private *priv = netdev_priv(dev);

	return (priv->tx_count >= TX_RING_ENTRIES - 1);
}

static void meth_tx_cleanup(struct net_device* dev, unsigned long int_status)
{
	struct meth_private *priv = netdev_priv(dev);
	unsigned long status;
	struct sk_buff *skb;
	unsigned long rptr = (int_status&TX_INFO_RPTR) >> 16;

	spin_lock(&priv->meth_lock);

	/* Stop DMA notification */
	priv->dma_ctrl &= ~(METH_DMA_TX_INT_EN);
	mace->eth.dma_ctrl = priv->dma_ctrl;

	while (priv->tx_read != rptr) {
		skb = priv->tx_skbs[priv->tx_read];
		status = priv->tx_ring[priv->tx_read].header.raw;
#if MFE_DEBUG>=1
		if (priv->tx_read == priv->tx_write)
			DPRINTK("Auchi! tx_read=%d,tx_write=%d,rptr=%d?\n", priv->tx_read, priv->tx_write,rptr);
#endif
		if (status & METH_TX_ST_DONE) {
			if (status & METH_TX_ST_SUCCESS){
				dev->stats.tx_packets++;
				dev->stats.tx_bytes += skb->len;
			} else {
				dev->stats.tx_errors++;
#if MFE_DEBUG>=1
				DPRINTK("TX error: status=%016lx <",status);
				if(status & METH_TX_ST_SUCCESS)
					printk(" SUCCESS");
				if(status & METH_TX_ST_TOOLONG)
					printk(" TOOLONG");
				if(status & METH_TX_ST_UNDERRUN)
					printk(" UNDERRUN");
				if(status & METH_TX_ST_EXCCOLL)
					printk(" EXCCOLL");
				if(status & METH_TX_ST_DEFER)
					printk(" DEFER");
				if(status & METH_TX_ST_LATECOLL)
					printk(" LATECOLL");
				printk(" >\n");
#endif
			}
		} else {
			DPRINTK("RPTR points us here, but packet not done?\n");
			break;
		}
		dev_kfree_skb_irq(skb);
		priv->tx_skbs[priv->tx_read] = NULL;
		priv->tx_ring[priv->tx_read].header.raw = 0;
		priv->tx_read = (priv->tx_read+1)&(TX_RING_ENTRIES-1);
		priv->tx_count--;
	}

	/* wake up queue if it was stopped */
	if (netif_queue_stopped(dev) && !meth_tx_full(dev)) {
		netif_wake_queue(dev);
	}

	mace->eth.int_stat = METH_INT_TX_EMPTY | METH_INT_TX_PKT;
	spin_unlock(&priv->meth_lock);
}

static void meth_error(struct net_device* dev, unsigned status)
{
	struct meth_private *priv = netdev_priv(dev);

	printk(KERN_WARNING "meth: error status: 0x%08x\n",status);
	/* check for errors too... */
	if (status & (METH_INT_TX_LINK_FAIL))
		printk(KERN_WARNING "meth: link failure\n");
	/* Should I do full reset in this case? */
	if (status & (METH_INT_MEM_ERROR))
		printk(KERN_WARNING "meth: memory error\n");
	if (status & (METH_INT_TX_ABORT))
		printk(KERN_WARNING "meth: aborted\n");
	if (status & (METH_INT_RX_OVERFLOW))
		printk(KERN_WARNING "meth: Rx overflow\n");
	if (status & (METH_INT_RX_UNDERFLOW)) {
		printk(KERN_WARNING "meth: Rx underflow\n");
		spin_lock(&priv->meth_lock);
		mace->eth.int_stat = METH_INT_RX_UNDERFLOW;
		/* more underflow interrupts will be delivered,
		 * effectively throwing us into an infinite loop.
		 *  Thus I stop processing Rx in this case. */
		priv->dma_ctrl &= ~METH_DMA_RX_EN;
		mace->eth.dma_ctrl = priv->dma_ctrl;
		DPRINTK("Disabled meth Rx DMA temporarily\n");
		spin_unlock(&priv->meth_lock);
	}
	mace->eth.int_stat = METH_INT_ERROR;
}

/*
 * The typical interrupt entry point
 */
static irqreturn_t meth_interrupt(int irq, void *dev_id)
{
	struct net_device *dev = (struct net_device *)dev_id;
	struct meth_private *priv = netdev_priv(dev);
	unsigned long status;

	status = mace->eth.int_stat;
	while (status & 0xff) {
		/* First handle errors - if we get Rx underflow,
		 * Rx DMA will be disabled, and Rx handler will reenable
		 * it. I don't think it's possible to get Rx underflow,
		 * without getting Rx interrupt */
		if (status & METH_INT_ERROR) {
			meth_error(dev, status);
		}
		if (status & (METH_INT_TX_EMPTY | METH_INT_TX_PKT)) {
			/* a transmission is over: free the skb */
			meth_tx_cleanup(dev, status);
		}
		if (status & METH_INT_RX_THRESHOLD) {
			if (!(priv->dma_ctrl & METH_DMA_RX_INT_EN))
				break;
			/* send it to meth_rx for handling */
			meth_rx(dev, status);
		}
		status = mace->eth.int_stat;
	}

	return IRQ_HANDLED;
}

/*
 * Transmits packets that fit into TX descriptor (are <=120B)
 */
static void meth_tx_short_prepare(struct meth_private *priv,
				  struct sk_buff *skb)
{
	tx_packet *desc = &priv->tx_ring[priv->tx_write];
	int len = (skb->len < ETH_ZLEN) ? ETH_ZLEN : skb->len;

	desc->header.raw = METH_TX_CMD_INT_EN | (len-1) | ((128-len) << 16);
	/* maybe I should set whole thing to 0 first... */
	skb_copy_from_linear_data(skb, desc->data.dt + (120 - len), skb->len);
	if (skb->len < len)
		memset(desc->data.dt + 120 - len + skb->len, 0, len-skb->len);
}
#define TX_CATBUF1 BIT(25)
static void meth_tx_1page_prepare(struct meth_private *priv,
				  struct sk_buff *skb)
{
	tx_packet *desc = &priv->tx_ring[priv->tx_write];
	void *buffer_data = (void *)(((unsigned long)skb->data + 7) & ~7);
	int unaligned_len = (int)((unsigned long)buffer_data - (unsigned long)skb->data);
	int buffer_len = skb->len - unaligned_len;
	dma_addr_t catbuf;

	desc->header.raw = METH_TX_CMD_INT_EN | TX_CATBUF1 | (skb->len - 1);

	/* unaligned part */
	if (unaligned_len) {
		skb_copy_from_linear_data(skb, desc->data.dt + (120 - unaligned_len),
			      unaligned_len);
		desc->header.raw |= (128 - unaligned_len) << 16;
	}

	/* first page */
	catbuf = dma_map_single(NULL, buffer_data, buffer_len,
				DMA_TO_DEVICE);
	desc->data.cat_buf[0].form.start_addr = catbuf >> 3;
	desc->data.cat_buf[0].form.len = buffer_len - 1;
}
#define TX_CATBUF2 BIT(26)
static void meth_tx_2page_prepare(struct meth_private *priv,
				  struct sk_buff *skb)
{
	tx_packet *desc = &priv->tx_ring[priv->tx_write];
	void *buffer1_data = (void *)(((unsigned long)skb->data + 7) & ~7);
	void *buffer2_data = (void *)PAGE_ALIGN((unsigned long)skb->data);
	int unaligned_len = (int)((unsigned long)buffer1_data - (unsigned long)skb->data);
	int buffer1_len = (int)((unsigned long)buffer2_data - (unsigned long)buffer1_data);
	int buffer2_len = skb->len - buffer1_len - unaligned_len;
	dma_addr_t catbuf1, catbuf2;

	desc->header.raw = METH_TX_CMD_INT_EN | TX_CATBUF1 | TX_CATBUF2| (skb->len - 1);
	/* unaligned part */
	if (unaligned_len){
		skb_copy_from_linear_data(skb, desc->data.dt + (120 - unaligned_len),
			      unaligned_len);
		desc->header.raw |= (128 - unaligned_len) << 16;
	}

	/* first page */
	catbuf1 = dma_map_single(NULL, buffer1_data, buffer1_len,
				 DMA_TO_DEVICE);
	desc->data.cat_buf[0].form.start_addr = catbuf1 >> 3;
	desc->data.cat_buf[0].form.len = buffer1_len - 1;
	/* second page */
	catbuf2 = dma_map_single(NULL, buffer2_data, buffer2_len,
				 DMA_TO_DEVICE);
	desc->data.cat_buf[1].form.start_addr = catbuf2 >> 3;
	desc->data.cat_buf[1].form.len = buffer2_len - 1;
}

static void meth_add_to_tx_ring(struct meth_private *priv, struct sk_buff *skb)
{
	/* Remember the skb, so we can free it at interrupt time */
	priv->tx_skbs[priv->tx_write] = skb;
	if (skb->len <= 120) {
		/* Whole packet fits into descriptor */
		meth_tx_short_prepare(priv, skb);
	} else if (PAGE_ALIGN((unsigned long)skb->data) !=
		   PAGE_ALIGN((unsigned long)skb->data + skb->len - 1)) {
		/* Packet crosses page boundary */
		meth_tx_2page_prepare(priv, skb);
	} else {
		/* Packet is in one page */
		meth_tx_1page_prepare(priv, skb);
	}
	priv->tx_write = (priv->tx_write + 1) & (TX_RING_ENTRIES - 1);
	mace->eth.tx_info = priv->tx_write;
	priv->tx_count++;
}

/*
 * Transmit a packet (called by the kernel)
 */
static int meth_tx(struct sk_buff *skb, struct net_device *dev)
{
	struct meth_private *priv = netdev_priv(dev);
	unsigned long flags;

	spin_lock_irqsave(&priv->meth_lock, flags);
	/* Stop DMA notification */
	priv->dma_ctrl &= ~(METH_DMA_TX_INT_EN);
	mace->eth.dma_ctrl = priv->dma_ctrl;

	meth_add_to_tx_ring(priv, skb);
	dev->trans_start = jiffies; /* save the timestamp */

	/* If TX ring is full, tell the upper layer to stop sending packets */
	if (meth_tx_full(dev)) {
	        printk(KERN_DEBUG "TX full: stopping\n");
		netif_stop_queue(dev);
	}

	/* Restart DMA notification */
	priv->dma_ctrl |= METH_DMA_TX_INT_EN;
	mace->eth.dma_ctrl = priv->dma_ctrl;

	spin_unlock_irqrestore(&priv->meth_lock, flags);

	return 0;
}

/*
 * Deal with a transmit timeout.
 */
static void meth_tx_timeout(struct net_device *dev)
{
	struct meth_private *priv = netdev_priv(dev);
	unsigned long flags;

	printk(KERN_WARNING "%s: transmit timed out\n", dev->name);

	/* Protect against concurrent rx interrupts */
	spin_lock_irqsave(&priv->meth_lock,flags);

	/* Try to reset the interface. */
	meth_reset(dev);

	dev->stats.tx_errors++;

	/* Clear all rings */
	meth_free_tx_ring(priv);
	meth_free_rx_ring(priv);
	meth_init_tx_ring(priv);
	meth_init_rx_ring(priv);

	/* Restart dma */
	priv->dma_ctrl |= METH_DMA_TX_EN | METH_DMA_RX_EN | METH_DMA_RX_INT_EN;
	mace->eth.dma_ctrl = priv->dma_ctrl;

	/* Enable interrupt */
	spin_unlock_irqrestore(&priv->meth_lock, flags);

	dev->trans_start = jiffies;
	netif_wake_queue(dev);

	return;
}

/*
 * Ioctl commands
 */
static int meth_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
{
	/* XXX Not yet implemented */
	switch(cmd) {
	case SIOCGMIIPHY:
	case SIOCGMIIREG:
	case SIOCSMIIREG:
	default:
		return -EOPNOTSUPP;
	}
}

/*
 * Return statistics to the caller
 */
/*
 * The init function.
 */
static int __init meth_probe(struct platform_device *pdev)
{
	struct net_device *dev;
	struct meth_private *priv;
	int err;

	dev = alloc_etherdev(sizeof(struct meth_private));
	if (!dev)
		return -ENOMEM;

	dev->open            = meth_open;
	dev->stop            = meth_release;
	dev->hard_start_xmit = meth_tx;
	dev->do_ioctl        = meth_ioctl;
#ifdef HAVE_TX_TIMEOUT
	dev->tx_timeout      = meth_tx_timeout;
	dev->watchdog_timeo  = timeout;
#endif
	dev->irq	     = MACE_ETHERNET_IRQ;
	dev->base_addr	     = (unsigned long)&mace->eth;
	memcpy(dev->dev_addr, o2meth_eaddr, 6);

	priv = netdev_priv(dev);
	spin_lock_init(&priv->meth_lock);
	SET_NETDEV_DEV(dev, &pdev->dev);

	err = register_netdev(dev);
	if (err) {
		free_netdev(dev);
		return err;
	}

	printk(KERN_INFO "%s: SGI MACE Ethernet rev. %d\n",
	       dev->name, (unsigned int)(mace->eth.mac_ctrl >> 29));
	return 0;
}

static int __exit meth_remove(struct platform_device *pdev)
{
	struct net_device *dev = platform_get_drvdata(pdev);

	unregister_netdev(dev);
	free_netdev(dev);
	platform_set_drvdata(pdev, NULL);

	return 0;
}

static struct platform_driver meth_driver = {
	.probe	= meth_probe,
	.remove	= __devexit_p(meth_remove),
	.driver = {
		.name	= "meth",
	}
};

static int __init meth_init_module(void)
{
	int err;

	err = platform_driver_register(&meth_driver);
	if (err)
		printk(KERN_ERR "Driver registration failed\n");

	return err;
}

static void __exit meth_exit_module(void)
{
	platform_driver_unregister(&meth_driver);
}

module_init(meth_init_module);
module_exit(meth_exit_module);

MODULE_AUTHOR("Ilya Volynets <[e-mail]>");
MODULE_DESCRIPTION("SGI O2 Builtin Fast Ethernet driver");
MODULE_LICENSE("GPL");