meth.c

来自「Linux Kernel 2.6.9 for OMAP1710」· C语言 代码 · 共 859 行 · 第 1/2 页

			} else {
				skb=alloc_skb(METH_RX_BUFF_SIZE,GFP_ATOMIC|GFP_DMA);
				if(!skb){
					/* Ouch! No memory! Drop packet on the floor */
					DPRINTK("No mem: dropping packet\n");
					priv->stats.rx_dropped++;
					skb=priv->rx_skbs[priv->rx_write];
				} else {
					struct sk_buff *skb_c=priv->rx_skbs[priv->rx_write];
					/* 8byte status vector+3quad padding + 2byte padding,
					   to put data on 64bit aligned boundary */
					skb_reserve(skb,METH_RX_HEAD);
					/* Write metadata, and then pass to the receive level */
					skb_put(skb_c,len);
					priv->rx_skbs[priv->rx_write]=skb;
					skb_c->dev = dev;
					skb_c->protocol = eth_type_trans(skb_c, dev);
					dev->last_rx = jiffies;
					priv->stats.rx_packets++;
					priv->stats.rx_bytes+=len;
					netif_rx(skb_c);
				}
			}
		} else {
			priv->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_write(priv->rx_ring_dmas[priv->rx_write], rx_fifo);
		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_write(priv->dma_ctrl, dma_ctrl);
	mace_eth_write(METH_INT_RX_THRESHOLD, int_stat);
	spin_unlock(&priv->meth_lock);
}

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

	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 = dev->priv;
	u64 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_write(priv->dma_ctrl, 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){
				priv->stats.tx_packets++;
				priv->stats.tx_bytes += skb->len;
			} else {
				priv->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_write(METH_INT_TX_EMPTY | METH_INT_TX_PKT, int_stat);
	spin_unlock(&priv->meth_lock);
}

static void meth_error(struct net_device* dev, u32 status)
{
	struct meth_private *priv = (struct meth_private *) dev->priv;

	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_write(METH_INT_RX_UNDERFLOW, int_stat);
		/* 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_write(priv->dma_ctrl, dma_ctrl);
		DPRINTK("Disabled meth Rx DMA temporarily\n");
		spin_unlock(&priv->meth_lock);
	}
	mace_eth_write(METH_INT_ERROR, int_stat);
}

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

	status = mace_eth_read(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_read(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... */
	memcpy(desc->data.dt+(120-len),skb->data,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){
		memcpy(desc->data.dt+(120-unaligned_len),
		       skb->data, 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){
		memcpy(desc->data.dt+(120-unaligned_len),
		       skb->data, 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_write(priv->tx_write, tx_info);
	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 = (struct meth_private *) dev->priv;
	unsigned long flags;

	spin_lock_irqsave(&priv->meth_lock,flags);
	/* Stop DMA notification */
	priv->dma_ctrl &= ~(METH_DMA_TX_INT_EN);
	mace_eth_write(priv->dma_ctrl, 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_write(priv->dma_ctrl, 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 = (struct meth_private *) dev->priv;
	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);

	priv->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_write(priv->dma_ctrl, 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)
{
	DPRINTK("ioctl\n");
	return 0;
}

/*
 * Return statistics to the caller
 */
static struct net_device_stats *meth_stats(struct net_device *dev)
{
	struct meth_private *priv = (struct meth_private *) dev->priv;
	return &priv->stats;
}

/*
 * The init function.
 */
static struct net_device *meth_init(void)
{
	struct net_device *dev;
	struct meth_private *priv;
	int ret;

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

	dev->open            = meth_open;
	dev->stop            = meth_release;
	dev->set_config      = meth_config;
	dev->hard_start_xmit = meth_tx;
	dev->do_ioctl        = meth_ioctl;
	dev->get_stats       = meth_stats;
#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;

	priv = (struct meth_private *) dev->priv;
	spin_lock_init(&priv->meth_lock);

	ret = register_netdev(dev);
	if (ret) {
		free_netdev(dev);
		return ERR_PTR(ret);
	}

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

static struct net_device *meth_dev;

static int __init meth_init_module(void)
{
	meth_dev = meth_init();
	if (IS_ERR(meth_dev))
		return PTR_ERR(meth_dev);
	return 0;
}

static void __exit meth_exit_module(void)
{
	unregister_netdev(meth_dev);
	free_netdev(meth_dev);
}

module_init(meth_init_module);
module_exit(meth_exit_module);