From d3f6f3a1d818410c17445bce4f4caab52eb102f1 Mon Sep 17 00:00:00 2001 From: Michael Chan Date: Sun, 11 May 2014 20:22:54 -0700 Subject: [PATCH] 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: Prashant Sreedharan Signed-off-by: Michael Chan Signed-off-by: David S. Miller --- drivers/net/ethernet/broadcom/tg3.c | 33 +++++++++++++++++++++++------ 1 file changed, 26 insertions(+), 7 deletions(-) diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c index bdfd08bcfe57..36b2b51facb9 100644 --- a/drivers/net/ethernet/broadcom/tg3.c +++ b/drivers/net/ethernet/broadcom/tg3.c @@ -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. */ -- 2.34.1