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Commit 0a5aeee0 authored by David Woodhouse's avatar David Woodhouse Committed by David S. Miller
Browse files

8139cp: Reduce duplicate csum/tso code in cp_start_xmit() 



We calculate the value of the opts1 descriptor field in three different
places. With two different behaviours when given an invalid packet to
be checksummed — none of them correct. Sort that out.

Signed-off-by: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a3b80404

drivers/net/ethernet/realtek/8139cp.c

+20 −41
Original line number Diff line number Diff line
@@ -733,7 +733,7 @@ static netdev_tx_t cp_start_xmit (struct sk_buff *skb, 
{

	struct cp_private *cp = netdev_priv(dev);

	unsigned entry;

	u32 eor, flags;

	u32 eor, opts1;

	unsigned long intr_flags;

	__le32 opts2;

	int mss = 0;
@@ -753,6 +753,21 @@ static netdev_tx_t cp_start_xmit (struct sk_buff *skb, 
	mss = skb_shinfo(skb)->gso_size;



	opts2 = cpu_to_le32(cp_tx_vlan_tag(skb));

	opts1 = DescOwn;

	if (mss)

		opts1 |= LargeSend | ((mss & MSSMask) << MSSShift);

	else if (skb->ip_summed == CHECKSUM_PARTIAL) {

		const struct iphdr *ip = ip_hdr(skb);

		if (ip->protocol == IPPROTO_TCP)

			opts1 |= IPCS | TCPCS;

		else if (ip->protocol == IPPROTO_UDP)

			opts1 |= IPCS | UDPCS;

		else {

			WARN_ONCE(1,

				  "Net bug: asked to checksum invalid Legacy IP packet\n");

			goto out_dma_error;

		}

	}



	if (skb_shinfo(skb)->nr_frags == 0) {

		struct cp_desc *txd = &cp->tx_ring[entry];
@@ -768,21 +783,9 @@ static netdev_tx_t cp_start_xmit (struct sk_buff *skb, 
		txd->addr = cpu_to_le64(mapping);

		wmb();



		flags = eor | len | DescOwn | FirstFrag | LastFrag;

		opts1 |= eor | len | FirstFrag | LastFrag;



		if (mss)

			flags |= LargeSend | ((mss & MSSMask) << MSSShift);

		else if (skb->ip_summed == CHECKSUM_PARTIAL) {

			const struct iphdr *ip = ip_hdr(skb);

			if (ip->protocol == IPPROTO_TCP)

				flags |= IPCS | TCPCS;

			else if (ip->protocol == IPPROTO_UDP)

				flags |= IPCS | UDPCS;

			else

				WARN_ON(1);	/* we need a WARN() */

		}



		txd->opts1 = cpu_to_le32(flags);

		txd->opts1 = cpu_to_le32(opts1);

		wmb();



		cp->tx_skb[entry] = skb;
@@ -793,7 +796,6 @@ static netdev_tx_t cp_start_xmit (struct sk_buff *skb, 
		u32 first_len, first_eor, ctrl;

		dma_addr_t first_mapping;

		int frag, first_entry = entry;

		const struct iphdr *ip = ip_hdr(skb);



		/* We must give this initial chunk to the device last.

		 * Otherwise we could race with the device.
@@ -825,19 +827,7 @@ static netdev_tx_t cp_start_xmit (struct sk_buff *skb, 


			eor = (entry == (CP_TX_RING_SIZE - 1)) ? RingEnd : 0;



			ctrl = eor | len | DescOwn;



			if (mss)

				ctrl |= LargeSend |

					((mss & MSSMask) << MSSShift);

			else if (skb->ip_summed == CHECKSUM_PARTIAL) {

				if (ip->protocol == IPPROTO_TCP)

					ctrl |= IPCS | TCPCS;

				else if (ip->protocol == IPPROTO_UDP)

					ctrl |= IPCS | UDPCS;

				else

					BUG();

			}

			ctrl = opts1 | eor | len;



			if (frag == skb_shinfo(skb)->nr_frags - 1)

				ctrl |= LastFrag;
@@ -857,18 +847,7 @@ static netdev_tx_t cp_start_xmit (struct sk_buff *skb, 
		txd->addr = cpu_to_le64(first_mapping);

		wmb();



		ctrl = first_eor | first_len | FirstFrag | DescOwn;

		if (mss)

			ctrl |= LargeSend | ((mss & MSSMask) << MSSShift);

		else if (skb->ip_summed == CHECKSUM_PARTIAL) {

			if (ip->protocol == IPPROTO_TCP)

				ctrl |= IPCS | TCPCS;

			else if (ip->protocol == IPPROTO_UDP)

				ctrl |= IPCS | UDPCS;

			else

				BUG();

		}



		ctrl = opts1 | first_eor | first_len | FirstFrag;

		txd->opts1 = cpu_to_le32(ctrl);

		wmb();