Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit d3f6f3a1 authored by Michael Chan's avatar Michael Chan Committed by David S. Miller
Browse files

tg3: Prevent page allocation failure during TSO workaround 



If any TSO fragment hits hardware bug conditions (e.g. 4G boundary), the
driver will workaround by calling skb_copy() to copy to a linear SKB.  Users
have reported page allocation failures as the TSO packet can be up to 64K.
Copying such a large packet is also very inefficient.  We fix this by using
existing tg3_tso_bug() to transmit the packet using GSO.

Signed-off-by: default avatarPrashant Sreedharan <prashant@broadcom.com>
Signed-off-by: default avatarMichael Chan <mchan@broadcom.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent d71c0dc4

drivers/net/ethernet/broadcom/tg3.c

+26 −7
Original line number Diff line number Diff line
@@ -7882,6 +7882,10 @@ static netdev_tx_t tg3_start_xmit(struct sk_buff *skb, struct net_device *dev) 
	struct tg3_napi *tnapi;

	struct netdev_queue *txq;

	unsigned int last;

	struct iphdr *iph = NULL;

	struct tcphdr *tcph = NULL;

	__sum16 tcp_csum = 0, ip_csum = 0;

	__be16 ip_tot_len = 0;



	txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb));

	tnapi = &tp->napi[skb_get_queue_mapping(skb)];
@@ -7913,7 +7917,6 @@ static netdev_tx_t tg3_start_xmit(struct sk_buff *skb, struct net_device *dev) 


	mss = skb_shinfo(skb)->gso_size;

	if (mss) {

		struct iphdr *iph;

		u32 tcp_opt_len, hdr_len;



		if (skb_cow_head(skb, 0))
@@ -7929,6 +7932,8 @@ static netdev_tx_t tg3_start_xmit(struct sk_buff *skb, struct net_device *dev) 
			    tg3_flag(tp, TSO_BUG))

				return tg3_tso_bug(tp, skb);



			ip_csum = iph->check;

			ip_tot_len = iph->tot_len;

			iph->check = 0;

			iph->tot_len = htons(mss + hdr_len);

		}
@@ -7936,16 +7941,18 @@ static netdev_tx_t tg3_start_xmit(struct sk_buff *skb, struct net_device *dev) 
		base_flags |= (TXD_FLAG_CPU_PRE_DMA |

			       TXD_FLAG_CPU_POST_DMA);



		tcph = tcp_hdr(skb);

		tcp_csum = tcph->check;



		if (tg3_flag(tp, HW_TSO_1) ||

		    tg3_flag(tp, HW_TSO_2) ||

		    tg3_flag(tp, HW_TSO_3)) {

			tcp_hdr(skb)->check = 0;

			tcph->check = 0;

			base_flags &= ~TXD_FLAG_TCPUDP_CSUM;

		} else

			tcp_hdr(skb)->check = ~csum_tcpudp_magic(iph->saddr,

								 iph->daddr, 0,

								 IPPROTO_TCP,

								 0);

		} else {

			tcph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr,

							 0, IPPROTO_TCP, 0);

		}



		if (tg3_flag(tp, HW_TSO_3)) {

			mss |= (hdr_len & 0xc) << 12;
@@ -8045,6 +8052,18 @@ static netdev_tx_t tg3_start_xmit(struct sk_buff *skb, struct net_device *dev) 
	if (would_hit_hwbug) {

		tg3_tx_skb_unmap(tnapi, tnapi->tx_prod, i);



		if (mss) {

			/* If it's a TSO packet, do GSO instead of

			 * allocating and copying to a large linear SKB

			 */

			if (ip_tot_len) {

				iph->check = ip_csum;

				iph->tot_len = ip_tot_len;

			}

			tcph->check = tcp_csum;

			return tg3_tso_bug(tp, skb);

		}



		/* If the workaround fails due to memory/mapping

		 * failure, silently drop this packet.

		 */