[Intel-wired-lan] [next PATCH 1/3] i40e: Refactor TSO to resolve unwanted behaviors
Alexander Duyck
aduyck at mirantis.com
Fri Jan 15 04:41:56 UTC 2016
This patch is meant to be a general clean-up of tso. There were a number
of spots where redundant actions were being taken in regards to the TSO
function and the checksum function, or in some cases frames were
technically being corrupted with checksums that were never requested.
So first of this patch goes through and takes all the spots that were
writing the outer IP header checksum to zero and moves them all into the
TSO function. (This includes the spot in IPv6 where this was occurring).
The second big change I made was to rework the outer checksum functionality
so that it would be used when requested via GSO instead of just inserting
it on all of the headers. This way we should be able to control if it is
enabled or not via the "udpcsum" flag when creating a VXLANn tunnel. The
functionality will likely not be needed for non-segmented frames as we will
be able to just compute the checksum via local checksum offload.
I also dropped some useless flags from the hw_enc_features. Specifically
SCTP offload and RX_CSUM don't have any impact on the actual offloads
provided. Specifically a tunnel doesn't advertise SCTP support, mainly
because it is a CRC offload and there is no support for doing it via a
software offload. The RX_CSUM feature doesn't provide any value add due to
the fact that it doesn't really do anything for the tunnel. It either
receives checksum offloaded frames or not. If it chooses to ignore them is
entirely up to it.
Signed-off-by: Alexander Duyck <aduyck at mirantis.com>
---
drivers/net/ethernet/intel/i40e/i40e_main.c | 16 ++---
drivers/net/ethernet/intel/i40e/i40e_txrx.c | 93 ++++++++++++++++-----------
drivers/net/ethernet/intel/i40e/i40e_txrx.h | 1
3 files changed, 62 insertions(+), 48 deletions(-)
diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index 2cfdd85f50fb..c21ad853d72f 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -7473,8 +7473,6 @@ static int i40e_alloc_rings(struct i40e_vsi *vsi)
tx_ring->dcb_tc = 0;
if (vsi->back->flags & I40E_FLAG_WB_ON_ITR_CAPABLE)
tx_ring->flags = I40E_TXR_FLAGS_WB_ON_ITR;
- if (vsi->back->flags & I40E_FLAG_OUTER_UDP_CSUM_CAPABLE)
- tx_ring->flags |= I40E_TXR_FLAGS_OUTER_UDP_CSUM;
vsi->tx_rings[i] = tx_ring;
rx_ring = &tx_ring[1];
@@ -9018,12 +9016,12 @@ static int i40e_config_netdev(struct i40e_vsi *vsi)
np = netdev_priv(netdev);
np->vsi = vsi;
- netdev->hw_enc_features |= NETIF_F_IP_CSUM |
- NETIF_F_RXCSUM |
- NETIF_F_SCTP_CRC |
- NETIF_F_GSO_UDP_TUNNEL |
- NETIF_F_GSO_GRE |
- NETIF_F_TSO |
+ netdev->hw_enc_features |= NETIF_F_IP_CSUM |
+ NETIF_F_TSO |
+ NETIF_F_TSO_ECN |
+ NETIF_F_GSO_GRE |
+ NETIF_F_GSO_UDP_TUNNEL |
+ NETIF_F_GSO_UDP_TUNNEL_CSUM |
0;
netdev->features = NETIF_F_SG |
@@ -9045,6 +9043,8 @@ static int i40e_config_netdev(struct i40e_vsi *vsi)
if (!(pf->flags & I40E_FLAG_MFP_ENABLED))
netdev->features |= NETIF_F_NTUPLE;
+ if (pf->flags & I40E_FLAG_OUTER_UDP_CSUM_CAPABLE)
+ netdev->features |= NETIF_F_GSO_UDP_TUNNEL_CSUM;
/* copy netdev features into list of user selectable features */
netdev->hw_features |= netdev->features;
diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
index ca5f0881a5bf..ac2fa7b02e94 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
@@ -2214,11 +2214,18 @@ out:
static int i40e_tso(struct i40e_ring *tx_ring, struct sk_buff *skb,
u8 *hdr_len, u64 *cd_type_cmd_tso_mss)
{
- u32 cd_cmd, cd_tso_len, cd_mss;
- struct ipv6hdr *ipv6h;
- struct tcphdr *tcph;
- struct iphdr *iph;
- u32 l4len;
+ u64 cd_cmd, cd_tso_len, cd_mss;
+ union {
+ struct iphdr *v4;
+ struct ipv6hdr *v6;
+ unsigned char *hdr;
+ } ip;
+ union {
+ struct tcphdr *tcp;
+ struct udphdr *udp;
+ unsigned char *hdr;
+ } l4;
+ u32 paylen, l4_offset;
int err;
if (skb->ip_summed != CHECKSUM_PARTIAL)
@@ -2231,35 +2238,51 @@ static int i40e_tso(struct i40e_ring *tx_ring, struct sk_buff *skb,
if (err < 0)
return err;
- iph = skb->encapsulation ? inner_ip_hdr(skb) : ip_hdr(skb);
- ipv6h = skb->encapsulation ? inner_ipv6_hdr(skb) : ipv6_hdr(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);
- ipv6h->payload_len = 0;
- tcph->check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr,
- 0, IPPROTO_TCP, 0);
+ ip.hdr = skb_network_header(skb);
+ l4.hdr = skb_transport_header(skb);
+
+ if (skb->encapsulation) {
+ if (ip.v4->version == 4) {
+ ip.v4->check = 0;
+ ip.v4->tot_len = 0;
+ } else {
+ ip.v6->payload_len = 0;
+ }
+
+ /* if we end up needing to do any changes such as update
+ * the pseudo header checksum on the outer header we
+ * should do it here.
+ */
+
+ ip.hdr = skb_inner_network_header(skb);
+ l4.hdr = skb_inner_transport_header(skb);
}
- 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;
+ /* initialize IP header fields */
+ if (ip.v4->version == 4) {
+ ip.v4->check = 0;
+ ip.v4->tot_len = 0;
+ } else {
+ ip.v6->payload_len = 0;
+ }
+
+ /* determine offset of transport header */
+ l4_offset = l4.hdr - skb->data;
+
+ /* remove payload length from checksum */
+ paylen = ntohs(1) * (u16)~(skb->len - l4_offset);
+ l4.tcp->check = ~csum_fold((__force __wsum)paylen + l4.tcp->check);
+
+ /* compute length of segmentation header */
+ *hdr_len = (l4.tcp->doff * 4) + l4_offset;
/* find the field values */
cd_cmd = I40E_TX_CTX_DESC_TSO;
cd_tso_len = skb->len - *hdr_len;
cd_mss = skb_shinfo(skb)->gso_size;
- *cd_type_cmd_tso_mss |= ((u64)cd_cmd << I40E_TXD_CTX_QW1_CMD_SHIFT) |
- ((u64)cd_tso_len <<
- I40E_TXD_CTX_QW1_TSO_LEN_SHIFT) |
- ((u64)cd_mss << I40E_TXD_CTX_QW1_MSS_SHIFT);
+ *cd_type_cmd_tso_mss |= (cd_cmd << I40E_TXD_CTX_QW1_CMD_SHIFT) |
+ (cd_tso_len << I40E_TXD_CTX_QW1_TSO_LEN_SHIFT) |
+ (cd_mss << I40E_TXD_CTX_QW1_MSS_SHIFT);
return 1;
}
@@ -2351,15 +2374,12 @@ static void i40e_tx_enable_csum(struct sk_buff *skb, u32 *tx_flags,
if (*tx_flags & I40E_TX_FLAGS_IPV4) {
if (*tx_flags & I40E_TX_FLAGS_TSO) {
*cd_tunneling |= I40E_TX_CTX_EXT_IP_IPV4;
- ip_hdr(skb)->check = 0;
} else {
*cd_tunneling |=
I40E_TX_CTX_EXT_IP_IPV4_NO_CSUM;
}
} else if (*tx_flags & I40E_TX_FLAGS_IPV6) {
*cd_tunneling |= I40E_TX_CTX_EXT_IP_IPV6;
- if (*tx_flags & I40E_TX_FLAGS_TSO)
- ip_hdr(skb)->check = 0;
}
/* Now set the ctx descriptor fields */
@@ -2373,15 +2393,11 @@ static void i40e_tx_enable_csum(struct sk_buff *skb, u32 *tx_flags,
*tx_flags &= ~I40E_TX_FLAGS_IPV4;
*tx_flags |= I40E_TX_FLAGS_IPV6;
}
- if ((tx_ring->flags & I40E_TXR_FLAGS_OUTER_UDP_CSUM) &&
- (l4_tunnel == I40E_TXD_CTX_UDP_TUNNELING) &&
- (*cd_tunneling & I40E_TXD_CTX_QW0_EXT_IP_MASK)) {
- oudph->check = ~csum_tcpudp_magic(oiph->saddr,
- oiph->daddr,
- (skb->len - skb_transport_offset(skb)),
- IPPROTO_UDP, 0);
+ /* indicate if we need to offload outer UDP header */
+ if ((*tx_flags & I40E_TX_FLAGS_TSO) &&
+ (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL_CSUM))
*cd_tunneling |= I40E_TXD_CTX_QW0_L4T_CS_MASK;
- }
+
} else {
network_hdr_len = skb_network_header_len(skb);
this_ip_hdr = ip_hdr(skb);
@@ -2397,7 +2413,6 @@ static void i40e_tx_enable_csum(struct sk_buff *skb, u32 *tx_flags,
*/
if (*tx_flags & I40E_TX_FLAGS_TSO) {
*td_cmd |= I40E_TX_DESC_CMD_IIPT_IPV4_CSUM;
- this_ip_hdr->check = 0;
} else {
*td_cmd |= I40E_TX_DESC_CMD_IIPT_IPV4;
}
diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.h b/drivers/net/ethernet/intel/i40e/i40e_txrx.h
index 1d167b646193..fc77a271aba8 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.h
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.h
@@ -275,7 +275,6 @@ struct i40e_ring {
u16 flags;
#define I40E_TXR_FLAGS_WB_ON_ITR BIT(0)
-#define I40E_TXR_FLAGS_OUTER_UDP_CSUM BIT(1)
#define I40E_TXR_FLAGS_LAST_XMIT_MORE_SET BIT(2)
/* stats structs */
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