From c49a7bc3308099a8d5f9e2e38adfc5ab969804aa Mon Sep 17 00:00:00 2001 From: Alexander Duyck Date: Sun, 24 Jan 2016 21:16:28 -0800 Subject: [PATCH] i40e/i40evf: Factor out L4 header and checksum from L3 bits in TSO path This patch makes it so that the L4 header offsets and such can be ignored when dealing with the L3 checksum and length update. This is done making use of two things. First we can just use the offset from the L4 header to the start of the packet to determine the L4 offset, and from that we can then make use of the data offset to determine the full length of the headers. As far as adjusting the checksum to remove the length we can simply add the inverse of the length instead of having to recompute the entire pseudo-header without the length. In the case of an IPv6 header this should be significantly cheaper since we can make use of a value we already needed instead of having to read the source and destination address out of the packet. Signed-off-by: Alexander Duyck Tested-by: Andrew Bowers Signed-off-by: Jeff Kirsher --- drivers/net/ethernet/intel/i40e/i40e_txrx.c | 31 +++++++++++-------- drivers/net/ethernet/intel/i40evf/i40e_txrx.c | 31 +++++++++++-------- 2 files changed, 36 insertions(+), 26 deletions(-) diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c index 5e825893f203..ce0234e67cc5 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c +++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c @@ -2269,9 +2269,12 @@ static int i40e_tso(struct i40e_ring *tx_ring, struct sk_buff *skb, { u64 cd_cmd, cd_tso_len, cd_mss; struct ipv6hdr *ipv6h; - struct tcphdr *tcph; struct iphdr *iph; - u32 l4len; + union { + struct tcphdr *tcp; + unsigned char *hdr; + } l4; + u32 paylen, l4_offset; int err; if (skb->ip_summed != CHECKSUM_PARTIAL) @@ -2286,24 +2289,26 @@ static int i40e_tso(struct i40e_ring *tx_ring, struct sk_buff *skb, iph = skb->encapsulation ? inner_ip_hdr(skb) : ip_hdr(skb); ipv6h = skb->encapsulation ? inner_ipv6_hdr(skb) : ipv6_hdr(skb); + l4.hdr = skb->encapsulation ? skb_inner_transport_header(skb) : + skb_transport_header(skb); if (iph->version == 4) { - tcph = skb->encapsulation ? inner_tcp_hdr(skb) : tcp_hdr(skb); iph->tot_len = 0; iph->check = 0; - tcph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, - 0, IPPROTO_TCP, 0); - } else if (ipv6h->version == 6) { - tcph = skb->encapsulation ? inner_tcp_hdr(skb) : tcp_hdr(skb); + } else { ipv6h->payload_len = 0; - tcph->check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr, - 0, IPPROTO_TCP, 0); } - l4len = skb->encapsulation ? inner_tcp_hdrlen(skb) : tcp_hdrlen(skb); - *hdr_len = (skb->encapsulation - ? (skb_inner_transport_header(skb) - skb->data) - : skb_transport_offset(skb)) + l4len; + /* determine offset of inner transport header */ + l4_offset = l4.hdr - skb->data; + + /* remove payload length from inner checksum */ + paylen = (__force u16)l4.tcp->check; + paylen += ntohs(1) * (u16)~(skb->len - l4_offset); + l4.tcp->check = ~csum_fold((__force __wsum)paylen); + + /* compute length of segmentation header */ + *hdr_len = (l4.tcp->doff * 4) + l4_offset; /* find the field values */ cd_cmd = I40E_TX_CTX_DESC_TSO; diff --git a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c index c5f98cba648a..881d0ada99fc 100644 --- a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c +++ b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c @@ -1529,9 +1529,12 @@ static int i40e_tso(struct i40e_ring *tx_ring, struct sk_buff *skb, { u64 cd_cmd, cd_tso_len, cd_mss; struct ipv6hdr *ipv6h; - struct tcphdr *tcph; struct iphdr *iph; - u32 l4len; + union { + struct tcphdr *tcp; + unsigned char *hdr; + } l4; + u32 paylen, l4_offset; int err; if (skb->ip_summed != CHECKSUM_PARTIAL) @@ -1546,24 +1549,26 @@ static int i40e_tso(struct i40e_ring *tx_ring, struct sk_buff *skb, iph = skb->encapsulation ? inner_ip_hdr(skb) : ip_hdr(skb); ipv6h = skb->encapsulation ? inner_ipv6_hdr(skb) : ipv6_hdr(skb); + l4.hdr = skb->encapsulation ? skb_inner_transport_header(skb) : + skb_transport_header(skb); if (iph->version == 4) { - tcph = skb->encapsulation ? inner_tcp_hdr(skb) : tcp_hdr(skb); iph->tot_len = 0; iph->check = 0; - tcph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, - 0, IPPROTO_TCP, 0); - } else if (ipv6h->version == 6) { - tcph = skb->encapsulation ? inner_tcp_hdr(skb) : tcp_hdr(skb); + } else { ipv6h->payload_len = 0; - tcph->check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr, - 0, IPPROTO_TCP, 0); } - l4len = skb->encapsulation ? inner_tcp_hdrlen(skb) : tcp_hdrlen(skb); - *hdr_len = (skb->encapsulation - ? (skb_inner_transport_header(skb) - skb->data) - : skb_transport_offset(skb)) + l4len; + /* determine offset of inner transport header */ + l4_offset = l4.hdr - skb->data; + + /* remove payload length from inner checksum */ + paylen = (__force u16)l4.tcp->check; + paylen += ntohs(1) * (u16)~(skb->len - l4_offset); + l4.tcp->check = ~csum_fold((__force __wsum)paylen); + + /* compute length of segmentation header */ + *hdr_len = (l4.tcp->doff * 4) + l4_offset; /* find the field values */ cd_cmd = I40E_TX_CTX_DESC_TSO; -- 2.30.2