mv643xx_eth.c

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	mv_read (INTERRUPT_CAUSE_EXTEND_REG(port_num));

	err = request_irq(dev->irq, mv643xx_eth_int_handler,
			IRQF_SHARED | IRQF_SAMPLE_RANDOM, dev->name, dev);
	if (err) {
		printk(KERN_ERR "Can not assign IRQ number to MV643XX_eth%d\n",
								port_num);
		return -EAGAIN;
	}

	eth_port_init(mp);

	memset(&mp->timeout, 0, sizeof(struct timer_list));
	mp->timeout.function = mv643xx_eth_rx_refill_descs_timer_wrapper;
	mp->timeout.data = (unsigned long)dev;

	/* Allocate RX and TX skb rings */
	mp->rx_skb = kmalloc(sizeof(*mp->rx_skb) * mp->rx_ring_size,
								GFP_KERNEL);
	if (!mp->rx_skb) {
		printk(KERN_ERR "%s: Cannot allocate Rx skb ring\n", dev->name);
		err = -ENOMEM;
		goto out_free_irq;
	}
	mp->tx_skb = kmalloc(sizeof(*mp->tx_skb) * mp->tx_ring_size,
								GFP_KERNEL);
	if (!mp->tx_skb) {
		printk(KERN_ERR "%s: Cannot allocate Tx skb ring\n", dev->name);
		err = -ENOMEM;
		goto out_free_rx_skb;
	}

	/* Allocate TX ring */
	mp->tx_desc_count = 0;
	size = mp->tx_ring_size * sizeof(struct eth_tx_desc);
	mp->tx_desc_area_size = size;

	if (mp->tx_sram_size) {
		mp->p_tx_desc_area = ioremap(mp->tx_sram_addr,
							mp->tx_sram_size);
		mp->tx_desc_dma = mp->tx_sram_addr;
	} else
		mp->p_tx_desc_area = dma_alloc_coherent(NULL, size,
							&mp->tx_desc_dma,
							GFP_KERNEL);

	if (!mp->p_tx_desc_area) {
		printk(KERN_ERR "%s: Cannot allocate Tx Ring (size %d bytes)\n",
							dev->name, size);
		err = -ENOMEM;
		goto out_free_tx_skb;
	}
	BUG_ON((u32) mp->p_tx_desc_area & 0xf);	/* check 16-byte alignment */
	memset((void *)mp->p_tx_desc_area, 0, mp->tx_desc_area_size);

	ether_init_tx_desc_ring(mp);

	/* Allocate RX ring */
	mp->rx_desc_count = 0;
	size = mp->rx_ring_size * sizeof(struct eth_rx_desc);
	mp->rx_desc_area_size = size;

	if (mp->rx_sram_size) {
		mp->p_rx_desc_area = ioremap(mp->rx_sram_addr,
							mp->rx_sram_size);
		mp->rx_desc_dma = mp->rx_sram_addr;
	} else
		mp->p_rx_desc_area = dma_alloc_coherent(NULL, size,
							&mp->rx_desc_dma,
							GFP_KERNEL);

	if (!mp->p_rx_desc_area) {
		printk(KERN_ERR "%s: Cannot allocate Rx ring (size %d bytes)\n",
							dev->name, size);
		printk(KERN_ERR "%s: Freeing previously allocated TX queues...",
							dev->name);
		if (mp->rx_sram_size)
			iounmap(mp->p_tx_desc_area);
		else
			dma_free_coherent(NULL, mp->tx_desc_area_size,
					mp->p_tx_desc_area, mp->tx_desc_dma);
		err = -ENOMEM;
		goto out_free_tx_skb;
	}
	memset((void *)mp->p_rx_desc_area, 0, size);

	ether_init_rx_desc_ring(mp);

	mv643xx_eth_rx_refill_descs(dev);	/* Fill RX ring with skb's */

#ifdef MV643XX_NAPI
	napi_enable(&mp->napi);
#endif

	eth_port_start(dev);

	/* Interrupt Coalescing */

#ifdef MV643XX_COAL
	mp->rx_int_coal =
		eth_port_set_rx_coal(port_num, 133000000, MV643XX_RX_COAL);
#endif

	mp->tx_int_coal =
		eth_port_set_tx_coal(port_num, 133000000, MV643XX_TX_COAL);

	/* Unmask phy and link status changes interrupts */
	mv_write(INTERRUPT_EXTEND_MASK_REG(port_num), ETH_INT_UNMASK_ALL_EXT);

	/* Unmask RX buffer and TX end interrupt */
	mv_write(INTERRUPT_MASK_REG(port_num), ETH_INT_UNMASK_ALL);

	return 0;

out_free_tx_skb:
	kfree(mp->tx_skb);
out_free_rx_skb:
	kfree(mp->rx_skb);
out_free_irq:
	free_irq(dev->irq, dev);

	return err;
}

static void mv643xx_eth_free_tx_rings(struct net_device *dev)
{
	struct mv643xx_private *mp = netdev_priv(dev);

	/* Stop Tx Queues */
	mv643xx_eth_port_disable_tx(mp->port_num);

	/* Free outstanding skb's on TX ring */
	mv643xx_eth_free_all_tx_descs(dev);

	BUG_ON(mp->tx_used_desc_q != mp->tx_curr_desc_q);

	/* Free TX ring */
	if (mp->tx_sram_size)
		iounmap(mp->p_tx_desc_area);
	else
		dma_free_coherent(NULL, mp->tx_desc_area_size,
				mp->p_tx_desc_area, mp->tx_desc_dma);
}

static void mv643xx_eth_free_rx_rings(struct net_device *dev)
{
	struct mv643xx_private *mp = netdev_priv(dev);
	unsigned int port_num = mp->port_num;
	int curr;

	/* Stop RX Queues */
	mv643xx_eth_port_disable_rx(port_num);

	/* Free preallocated skb's on RX rings */
	for (curr = 0; mp->rx_desc_count && curr < mp->rx_ring_size; curr++) {
		if (mp->rx_skb[curr]) {
			dev_kfree_skb(mp->rx_skb[curr]);
			mp->rx_desc_count--;
		}
	}

	if (mp->rx_desc_count)
		printk(KERN_ERR
			"%s: Error in freeing Rx Ring. %d skb's still"
			" stuck in RX Ring - ignoring them\n", dev->name,
			mp->rx_desc_count);
	/* Free RX ring */
	if (mp->rx_sram_size)
		iounmap(mp->p_rx_desc_area);
	else
		dma_free_coherent(NULL, mp->rx_desc_area_size,
				mp->p_rx_desc_area, mp->rx_desc_dma);
}

/*
 * mv643xx_eth_stop
 *
 * This function is used when closing the network device.
 * It updates the hardware,
 * release all memory that holds buffers and descriptors and release the IRQ.
 * Input :	a pointer to the device structure
 * Output :	zero if success , nonzero if fails
 */

static int mv643xx_eth_stop(struct net_device *dev)
{
	struct mv643xx_private *mp = netdev_priv(dev);
	unsigned int port_num = mp->port_num;

	/* Mask all interrupts on ethernet port */
	mv_write(INTERRUPT_MASK_REG(port_num), ETH_INT_MASK_ALL);
	/* wait for previous write to complete */
	mv_read(INTERRUPT_MASK_REG(port_num));

#ifdef MV643XX_NAPI
	napi_disable(&mp->napi);
#endif
	netif_carrier_off(dev);
	netif_stop_queue(dev);

	eth_port_reset(mp->port_num);

	mv643xx_eth_free_tx_rings(dev);
	mv643xx_eth_free_rx_rings(dev);

	free_irq(dev->irq, dev);

	return 0;
}

#ifdef MV643XX_NAPI
/*
 * mv643xx_poll
 *
 * This function is used in case of NAPI
 */
static int mv643xx_poll(struct napi_struct *napi, int budget)
{
	struct mv643xx_private *mp = container_of(napi, struct mv643xx_private, napi);
	struct net_device *dev = mp->dev;
	unsigned int port_num = mp->port_num;
	int work_done;

#ifdef MV643XX_TX_FAST_REFILL
	if (++mp->tx_clean_threshold > 5) {
		mv643xx_eth_free_completed_tx_descs(dev);
		mp->tx_clean_threshold = 0;
	}
#endif

	work_done = 0;
	if ((mv_read(RX_CURRENT_QUEUE_DESC_PTR_0(port_num)))
	    != (u32) mp->rx_used_desc_q)
		work_done = mv643xx_eth_receive_queue(dev, budget);

	if (work_done < budget) {
		netif_rx_complete(dev, napi);
		mv_write(INTERRUPT_CAUSE_REG(port_num), 0);
		mv_write(INTERRUPT_CAUSE_EXTEND_REG(port_num), 0);
		mv_write(INTERRUPT_MASK_REG(port_num), ETH_INT_UNMASK_ALL);
	}

	return work_done;
}
#endif

/**
 * has_tiny_unaligned_frags - check if skb has any small, unaligned fragments
 *
 * Hardware can't handle unaligned fragments smaller than 9 bytes.
 * This helper function detects that case.
 */

static inline unsigned int has_tiny_unaligned_frags(struct sk_buff *skb)
{
	unsigned int frag;
	skb_frag_t *fragp;

	for (frag = 0; frag < skb_shinfo(skb)->nr_frags; frag++) {
		fragp = &skb_shinfo(skb)->frags[frag];
		if (fragp->size <= 8 && fragp->page_offset & 0x7)
			return 1;
	}
	return 0;
}

/**
 * eth_alloc_tx_desc_index - return the index of the next available tx desc
 */
static int eth_alloc_tx_desc_index(struct mv643xx_private *mp)
{
	int tx_desc_curr;

	BUG_ON(mp->tx_desc_count >= mp->tx_ring_size);

	tx_desc_curr = mp->tx_curr_desc_q;
	mp->tx_curr_desc_q = (tx_desc_curr + 1) % mp->tx_ring_size;

	BUG_ON(mp->tx_curr_desc_q == mp->tx_used_desc_q);

	return tx_desc_curr;
}

/**
 * eth_tx_fill_frag_descs - fill tx hw descriptors for an skb's fragments.
 *
 * Ensure the data for each fragment to be transmitted is mapped properly,
 * then fill in descriptors in the tx hw queue.
 */
static void eth_tx_fill_frag_descs(struct mv643xx_private *mp,
				   struct sk_buff *skb)
{
	int frag;
	int tx_index;
	struct eth_tx_desc *desc;

	for (frag = 0; frag < skb_shinfo(skb)->nr_frags; frag++) {
		skb_frag_t *this_frag = &skb_shinfo(skb)->frags[frag];

		tx_index = eth_alloc_tx_desc_index(mp);
		desc = &mp->p_tx_desc_area[tx_index];

		desc->cmd_sts = ETH_BUFFER_OWNED_BY_DMA;
		/* Last Frag enables interrupt and frees the skb */
		if (frag == (skb_shinfo(skb)->nr_frags - 1)) {
			desc->cmd_sts |= ETH_ZERO_PADDING |
					 ETH_TX_LAST_DESC |
					 ETH_TX_ENABLE_INTERRUPT;
			mp->tx_skb[tx_index] = skb;
		} else
			mp->tx_skb[tx_index] = NULL;

		desc = &mp->p_tx_desc_area[tx_index];
		desc->l4i_chk = 0;
		desc->byte_cnt = this_frag->size;
		desc->buf_ptr = dma_map_page(NULL, this_frag->page,
						this_frag->page_offset,
						this_frag->size,
						DMA_TO_DEVICE);
	}
}

/**
 * eth_tx_submit_descs_for_skb - submit data from an skb to the tx hw
 *
 * Ensure the data for an skb to be transmitted is mapped properly,
 * then fill in descriptors in the tx hw queue and start the hardware.
 */
static void eth_tx_submit_descs_for_skb(struct mv643xx_private *mp,
					struct sk_buff *skb)
{
	int tx_index;
	struct eth_tx_desc *desc;
	u32 cmd_sts;
	int length;
	int nr_frags = skb_shinfo(skb)->nr_frags;

	cmd_sts = ETH_TX_FIRST_DESC | ETH_GEN_CRC | ETH_BUFFER_OWNED_BY_DMA;

	tx_index = eth_alloc_tx_desc_index(mp);
	desc = &mp->p_tx_desc_area[tx_index];

	if (nr_frags) {
		eth_tx_fill_frag_descs(mp, skb);

		length = skb_headlen(skb);
		mp->tx_skb[tx_index] = NULL;
	} else {
		cmd_sts |= ETH_ZERO_PADDING |
			   ETH_TX_LAST_DESC |
			   ETH_TX_ENABLE_INTERRUPT;
		length = skb->len;
		mp->tx_skb[tx_index] = skb;
	}

	desc->byte_cnt = length;
	desc->buf_ptr = dma_map_single(NULL, skb->data, length, DMA_TO_DEVICE);

	if (skb->ip_summed == CHECKSUM_PARTIAL) {
		BUG_ON(skb->protocol != ETH_P_IP);

		cmd_sts |= ETH_GEN_TCP_UDP_CHECKSUM |
			   ETH_GEN_IP_V_4_CHECKSUM  |
			   ip_hdr(skb)->ihl << ETH_TX_IHL_SHIFT;

		switch (ip_hdr(skb)->protocol) {
		case IPPROTO_UDP:
			cmd_sts |= ETH_UDP_FRAME;
			desc->l4i_chk = udp_hdr(skb)->check;
			break;
		case IPPROTO_TCP:
			desc->l4i_chk = tcp_hdr(skb)->check;
			break;
		default:
			BUG();
		}
	} else {
		/* Errata BTS #50, IHL must be 5 if no HW checksum */
		cmd_sts |= 5 << ETH_TX_IHL_SHIFT;
		desc->l4i_chk = 0;
	}

	/* ensure all other descriptors are written before first cmd_sts */
	wmb();
	desc->cmd_sts = cmd_sts;

	/* ensure all descriptors are written before poking hardware */
	wmb();
	mv643xx_eth_port_enable_tx(mp->port_num, ETH_TX_QUEUES_ENABLED);

	mp->tx_desc_count += nr_frags + 1;
}

/**
 * mv643xx_eth_start_xmit - queue an skb to the hardware for transmission
 *
 */
static int mv643xx_eth_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct mv643xx_private *mp = netdev_priv(dev);
	struct net_device_stats *stats = &dev->stats;
	unsigned long flags;

	BUG_ON(netif_queue_stopped(dev));
	BUG_ON(skb == NULL);

	if (mp->tx_ring_size - mp->tx_desc_count < MAX_DESCS_PER_SKB) {
		printk(KERN_ERR "%s: transmit with queue full\n", dev->name);
		netif_stop_queue(dev);
		return 1;
	}

	if (has_tiny_unaligned_frags(skb)) {
		if (__skb_linearize(skb)) {
			stats->tx_dropped++;
			printk(KERN_DEBUG "%s: failed to linearize tiny "
					"unaligned fragment\n", dev->name);
			return 1;
		}
	}

	spin_lock_irqsave(&mp->lock, flags);

	eth_tx_submit_descs_for_skb(mp, skb);
	stats->tx_bytes += skb->len;
	stats->tx_packets++;
	dev->trans_start = jiffies;

	if (mp->tx_ring_size - mp->tx_desc_count < MAX_DESCS_PER_SKB)
		netif_stop_queue(dev);

	spin_unlock_irqrestore(&mp->lock, flags);

	return 0;		/* success */
}

#ifdef CONFIG_NET_POLL_CONTROLLER
static void mv643xx_netpoll(struct net_device *netdev)
{
	struct mv643xx_private *mp = netdev_priv(netdev);
	int port_num = mp->port_num;

	mv_write(INTERRUPT_MASK_REG(port_num), ETH_INT_MASK_ALL);
	/* wait for previous write to complete */