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net/mlx5e: Add UDP GSO support 

This patch enables UDP GSO support. We enable this by using two WQEs
the first is a UDP LSO WQE for all segments with equal length, and the
second is for the last segment in case it has different length.
Due to HW limitation, before sending, we must adjust the packet length fields.

We measure performance between two Intel(R) Xeon(R) CPU E5-2643 v2 @3.50GHz
machines connected back-to-back with Connectx4-Lx (40Gbps) NICs.
We compare single stream UDP, UDP GSO and UDP GSO with offload.
Performance:
		| MSS (bytes)	| Throughput (Gbps)	| CPU utilization (%)
UDP GSO offload	| 1472		| 35.6			| 8%
UDP GSO 	| 1472		| 25.5			| 17%
UDP 		| 1472		| 10.2			| 17%
UDP GSO offload	| 1024		| 35.6			| 8%
UDP GSO		| 1024		| 19.2			| 17%
UDP 		| 1024		| 5.7			| 17%
UDP GSO offload	| 512		| 33.8			| 16%
UDP GSO		| 512		| 10.4			| 17%
UDP 		| 512		| 3.5			| 17%

Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: Yossi Kuperman <yossiku@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
This commit is contained in:
Boris Pismenny 2018-05-31 15:29:42 +03:00 committed by Saeed Mahameed
parent 7861552ced
commit 689adf0d48
6 changed files with 139 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
drivers/net/ethernet/mellanox/mlx5/core/Makefile
View File

@ -14,8 +14,8 @@ mlx5_core-$(CONFIG_MLX5_FPGA) += fpga/cmd.o fpga/core.o fpga/conn.o fpga/sdk.o \
fpga/ipsec.o fpga/tls.o
mlx5_core-$(CONFIG_MLX5_CORE_EN) += en_main.o en_common.o en_fs.o en_ethtool.o \
en_tx.o en_rx.o en_dim.o en_txrx.o en_stats.o vxlan.o \
en_arfs.o en_fs_ethtool.o en_selftest.o en/port.o
en_tx.o en_rx.o en_dim.o en_txrx.o en_accel/rxtx.o en_stats.o \
vxlan.o en_arfs.o en_fs_ethtool.o en_selftest.o en/port.o
mlx5_core-$(CONFIG_MLX5_MPFS) += lib/mpfs.o

11
drivers/net/ethernet/mellanox/mlx5/core/en_accel/en_accel.h
View File

@ -34,12 +34,11 @@
#ifndef __MLX5E_EN_ACCEL_H__
#define __MLX5E_EN_ACCEL_H__
#ifdef CONFIG_MLX5_ACCEL
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include "en_accel/ipsec_rxtx.h"
#include "en_accel/tls_rxtx.h"
#include "en_accel/rxtx.h"
#include "en.h"
static inline struct sk_buff *mlx5e_accel_handle_tx(struct sk_buff *skb,
@ -64,9 +63,13 @@ static inline struct sk_buff *mlx5e_accel_handle_tx(struct sk_buff *skb,
}
#endif
if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) {
skb = mlx5e_udp_gso_handle_tx_skb(dev, sq, skb, wqe, pi);
if (unlikely(!skb))
return NULL;
}
return skb;
}
#endif /* CONFIG_MLX5_ACCEL */
#endif /* __MLX5E_EN_ACCEL_H__ */

108
drivers/net/ethernet/mellanox/mlx5/core/en_accel/rxtx.c Normal file
View File

@ -0,0 +1,108 @@
#include "en_accel/rxtx.h"
static void mlx5e_udp_gso_prepare_last_skb(struct sk_buff *skb,
struct sk_buff *nskb,
int remaining)
{
int bytes_needed = remaining, remaining_headlen, remaining_page_offset;
int headlen = skb_transport_offset(skb) + sizeof(struct udphdr);
int payload_len = remaining + sizeof(struct udphdr);
int k = 0, i, j;
skb_copy_bits(skb, 0, nskb->data, headlen);
nskb->dev = skb->dev;
skb_reset_mac_header(nskb);
skb_set_network_header(nskb, skb_network_offset(skb));
skb_set_transport_header(nskb, skb_transport_offset(skb));
skb_set_tail_pointer(nskb, headlen);
/* How many frags do we need? */
for (i = skb_shinfo(skb)->nr_frags - 1; i >= 0; i--) {
bytes_needed -= skb_frag_size(&skb_shinfo(skb)->frags[i]);
k++;
if (bytes_needed <= 0)
break;
}
/* Fill the first frag and split it if necessary */
j = skb_shinfo(skb)->nr_frags - k;
remaining_page_offset = -bytes_needed;
skb_fill_page_desc(nskb, 0,
skb_shinfo(skb)->frags[j].page.p,
skb_shinfo(skb)->frags[j].page_offset + remaining_page_offset,
skb_shinfo(skb)->frags[j].size - remaining_page_offset);
skb_frag_ref(skb, j);
/* Fill the rest of the frags */
for (i = 1; i < k; i++) {
j = skb_shinfo(skb)->nr_frags - k + i;
skb_fill_page_desc(nskb, i,
skb_shinfo(skb)->frags[j].page.p,
skb_shinfo(skb)->frags[j].page_offset,
skb_shinfo(skb)->frags[j].size);
skb_frag_ref(skb, j);
}
skb_shinfo(nskb)->nr_frags = k;
remaining_headlen = remaining - skb->data_len;
/* headlen contains remaining data? */
if (remaining_headlen > 0)
skb_copy_bits(skb, skb->len - remaining, nskb->data + headlen,
remaining_headlen);
nskb->len = remaining + headlen;
nskb->data_len = payload_len - sizeof(struct udphdr) +
max_t(int, 0, remaining_headlen);
nskb->protocol = skb->protocol;
if (nskb->protocol == htons(ETH_P_IP)) {
ip_hdr(nskb)->id = htons(ntohs(ip_hdr(nskb)->id) +
skb_shinfo(skb)->gso_segs);
ip_hdr(nskb)->tot_len =
htons(payload_len + sizeof(struct iphdr));
} else {
ipv6_hdr(nskb)->payload_len = htons(payload_len);
}
udp_hdr(nskb)->len = htons(payload_len);
skb_shinfo(nskb)->gso_size = 0;
nskb->ip_summed = skb->ip_summed;
nskb->csum_start = skb->csum_start;
nskb->csum_offset = skb->csum_offset;
nskb->queue_mapping = skb->queue_mapping;
}
/* might send skbs and update wqe and pi */
struct sk_buff *mlx5e_udp_gso_handle_tx_skb(struct net_device *netdev,
struct mlx5e_txqsq *sq,
struct sk_buff *skb,
struct mlx5e_tx_wqe **wqe,
u16 *pi)
{
int payload_len = skb_shinfo(skb)->gso_size + sizeof(struct udphdr);
int headlen = skb_transport_offset(skb) + sizeof(struct udphdr);
int remaining = (skb->len - headlen) % skb_shinfo(skb)->gso_size;
struct sk_buff *nskb;
if (skb->protocol == htons(ETH_P_IP))
ip_hdr(skb)->tot_len = htons(payload_len + sizeof(struct iphdr));
else
ipv6_hdr(skb)->payload_len = htons(payload_len);
udp_hdr(skb)->len = htons(payload_len);
if (!remaining)
return skb;
nskb = alloc_skb(max_t(int, headlen, headlen + remaining - skb->data_len), GFP_ATOMIC);
if (unlikely(!nskb)) {
sq->stats->dropped++;
return NULL;
}
mlx5e_udp_gso_prepare_last_skb(skb, nskb, remaining);
skb_shinfo(skb)->gso_segs--;
pskb_trim(skb, skb->len - remaining);
mlx5e_sq_xmit(sq, skb, *wqe, *pi);
mlx5e_sq_fetch_wqe(sq, wqe, pi);
return nskb;
}

14
drivers/net/ethernet/mellanox/mlx5/core/en_accel/rxtx.h Normal file
View File

@ -0,0 +1,14 @@
#ifndef __MLX5E_EN_ACCEL_RX_TX_H__
#define __MLX5E_EN_ACCEL_RX_TX_H__
#include <linux/skbuff.h>
#include "en.h"
struct sk_buff *mlx5e_udp_gso_handle_tx_skb(struct net_device *netdev,
struct mlx5e_txqsq *sq,
struct sk_buff *skb,
struct mlx5e_tx_wqe **wqe,
u16 *pi);
#endif

3
drivers/net/ethernet/mellanox/mlx5/core/en_main.c
View File

@ -4592,6 +4592,9 @@ static void mlx5e_build_nic_netdev(struct net_device *netdev)
netdev->features |= NETIF_F_HIGHDMA;
netdev->features |= NETIF_F_HW_VLAN_STAG_FILTER;
netdev->features |= NETIF_F_GSO_UDP_L4;
netdev->hw_features |= NETIF_F_GSO_UDP_L4;
netdev->priv_flags |= IFF_UNICAST_FLT;
mlx5e_set_netdev_dev_addr(netdev);

8
drivers/net/ethernet/mellanox/mlx5/core/en_tx.c
View File

@ -228,7 +228,10 @@ mlx5e_tx_get_gso_ihs(struct mlx5e_txqsq *sq, struct sk_buff *skb)
stats->tso_inner_packets++;
stats->tso_inner_bytes += skb->len - ihs;
} else {
ihs = skb_transport_offset(skb) + tcp_hdrlen(skb);
if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4)
ihs = skb_transport_offset(skb) + sizeof(struct udphdr);
else
ihs = skb_transport_offset(skb) + tcp_hdrlen(skb);
stats->tso_packets++;
stats->tso_bytes += skb->len - ihs;
}
@ -443,12 +446,11 @@ netdev_tx_t mlx5e_xmit(struct sk_buff *skb, struct net_device *dev)
sq = priv->txq2sq[skb_get_queue_mapping(skb)];
mlx5e_sq_fetch_wqe(sq, &wqe, &pi);
#ifdef CONFIG_MLX5_ACCEL
/* might send skbs and update wqe and pi */
skb = mlx5e_accel_handle_tx(skb, sq, dev, &wqe, &pi);
if (unlikely(!skb))
return NETDEV_TX_OK;
#endif
return mlx5e_sq_xmit(sq, skb, wqe, pi);
}