Commit cd4ceb24 authored by Olof Johansson's avatar Olof Johansson Committed by Jeff Garzik
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pasemi_mac: Logic cleanup / rx performance improvements 



Logic cleanup and some performance enhancements to the RX path.

Signed-off-by: default avatarOlof Johansson <olof@lixom.net>
Signed-off-by: default avatarJeff Garzik <jeff@garzik.org>
parent cfa8007d

drivers/net/pasemi_mac.c

+37 −38
Original line number Diff line number Diff line
@@ -305,19 +305,20 @@ static void pasemi_mac_replenish_rx_ring(struct net_device *dev) 
	struct pasemi_mac *mac = netdev_priv(dev);

	unsigned int i;

	int start = mac->rx->next_to_fill;

	unsigned int count;

	unsigned int limit, count;



	count = (mac->rx->next_to_clean + RX_RING_SIZE -

	limit = (mac->rx->next_to_clean + RX_RING_SIZE -

		 mac->rx->next_to_fill) & (RX_RING_SIZE - 1);



	/* Check to see if we're doing first-time setup */

	if (unlikely(mac->rx->next_to_clean == 0 && mac->rx->next_to_fill == 0))

		count = RX_RING_SIZE;

		limit = RX_RING_SIZE;



	if (count <= 0)

	if (limit <= 0)

		return;



	for (i = start; i < start + count; i++) {

	i = start;

	for (count = limit; count; count--) {

		struct pasemi_mac_buffer *info = &RX_DESC_INFO(mac, i);

		u64 *buff = &RX_BUFF(mac, i);

		struct sk_buff *skb;
@@ -335,27 +336,27 @@ static void pasemi_mac_replenish_rx_ring(struct net_device *dev) 
		dma = pci_map_single(mac->dma_pdev, skb->data, skb->len,

				     PCI_DMA_FROMDEVICE);



		if (dma_mapping_error(dma)) {

		if (unlikely(dma_mapping_error(dma))) {

			dev_kfree_skb_irq(info->skb);

			count = i - start;

			break;

		}



		info->skb = skb;

		info->dma = dma;

		*buff = XCT_RXB_LEN(BUF_SIZE) | XCT_RXB_ADDR(dma);

		i++;

	}



	wmb();



	pci_write_config_dword(mac->dma_pdev,

			       PAS_DMA_RXCHAN_INCR(mac->dma_rxch),

			       count);

			       limit - count);

	pci_write_config_dword(mac->dma_pdev,

			       PAS_DMA_RXINT_INCR(mac->dma_if),

			       count);

			       limit - count);



	mac->rx->next_to_fill += count;

	mac->rx->next_to_fill += limit - count;

}



static void pasemi_mac_restart_rx_intr(struct pasemi_mac *mac)
@@ -393,32 +394,31 @@ static void pasemi_mac_restart_tx_intr(struct pasemi_mac *mac) 
}







static int pasemi_mac_clean_rx(struct pasemi_mac *mac, int limit)

{

	unsigned int i;

	int start, count;



	spin_lock(&mac->rx->lock);



	start = mac->rx->next_to_clean;

	count = 0;



	for (i = start; i < (start + RX_RING_SIZE) && count < limit; i++) {

	unsigned int n;

	int count;

	struct pas_dma_xct_descr *dp;

	struct pasemi_mac_buffer *info;

	struct sk_buff *skb;

		unsigned int j, len;

	unsigned int i, len;

	u64 macrx;

	dma_addr_t dma;



	spin_lock(&mac->rx->lock);



	n = mac->rx->next_to_clean;



	for (count = limit; count; count--) {



		rmb();



		dp = &RX_DESC(mac, i);

		dp = &RX_DESC(mac, n);

		macrx = dp->macrx;



		if (!(dp->macrx & XCT_MACRX_O))

		if (!(macrx & XCT_MACRX_O))

			break;



		count++;



		info = NULL;
@@ -430,22 +430,20 @@ static int pasemi_mac_clean_rx(struct pasemi_mac *mac, int limit) 
		 */



		dma = (dp->ptr & XCT_PTR_ADDR_M);

		for (j = start; j < (start + RX_RING_SIZE); j++) {

			info = &RX_DESC_INFO(mac, j);

		for (i = n; i < (n + RX_RING_SIZE); i++) {

			info = &RX_DESC_INFO(mac, i);

			if (info->dma == dma)

				break;

		}



		BUG_ON(!info);

		BUG_ON(info->dma != dma);

		skb = info->skb;

		info->dma = 0;



		pci_unmap_single(mac->dma_pdev, info->dma, info->skb->len,

		pci_unmap_single(mac->dma_pdev, dma, skb->len,

				 PCI_DMA_FROMDEVICE);

		info->dma = 0;



		len = (macrx & XCT_MACRX_LLEN_M) >> XCT_MACRX_LLEN_S;



		len = (dp->macrx & XCT_MACRX_LLEN_M) >> XCT_MACRX_LLEN_S;

		if (len < 256) {

			struct sk_buff *new_skb =

			    netdev_alloc_skb(mac->netdev, len + NET_IP_ALIGN);
@@ -465,9 +463,9 @@ static int pasemi_mac_clean_rx(struct pasemi_mac *mac, int limit) 


		skb->protocol = eth_type_trans(skb, mac->netdev);



		if ((dp->macrx & XCT_MACRX_HTY_M) == XCT_MACRX_HTY_IPV4_OK) {

		if ((macrx & XCT_MACRX_HTY_M) == XCT_MACRX_HTY_IPV4_OK) {

			skb->ip_summed = CHECKSUM_COMPLETE;

			skb->csum = (dp->macrx & XCT_MACRX_CSUM_M) >>

			skb->csum = (macrx & XCT_MACRX_CSUM_M) >>

					   XCT_MACRX_CSUM_S;

		} else

			skb->ip_summed = CHECKSUM_NONE;
@@ -477,13 +475,13 @@ static int pasemi_mac_clean_rx(struct pasemi_mac *mac, int limit) 


		netif_receive_skb(skb);



		info->dma = 0;

		info->skb = NULL;

		dp->ptr = 0;

		dp->macrx = 0;



		n++;

	}



	mac->rx->next_to_clean += count;

	mac->rx->next_to_clean += limit - count;

	pasemi_mac_replenish_rx_ring(mac->netdev);



	spin_unlock(&mac->rx->lock);
@@ -899,6 +897,9 @@ static int pasemi_mac_poll(struct net_device *dev, int *budget) 


	pkts = pasemi_mac_clean_rx(mac, limit);



	dev->quota -= pkts;

	*budget -= pkts;



	if (pkts < limit) {

		/* all done, no more packets present */

		netif_rx_complete(dev);
@@ -907,8 +908,6 @@ static int pasemi_mac_poll(struct net_device *dev, int *budget) 
		return 0;

	} else {

		/* used up our quantum, so reschedule */

		dev->quota -= pkts;

		*budget -= pkts;

		return 1;

	}

}