Commit 1169a642 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

mlx4: support BIG TCP packets 



mlx4 supports LSOv2 just fine.

IPv6 stack inserts a temporary Hop-by-Hop header
with JUMBO TLV for big packets.

We need to ignore the HBH header when populating TX descriptor.

Tested:

Before: (not enabling bigger TSO/GRO packets)

ip link set dev eth0 gso_max_size 65536 gro_max_size 65536

netperf -H lpaa18 -t TCP_RR -T2,2 -l 10 -Cc -- -r 70000,70000
MIGRATED TCP REQUEST/RESPONSE TEST from ::0 (::) port 0 AF_INET6 to lpaa18.prod.google.com () port 0 AF_INET6 : first burst 0 : cpu bind
Local /Remote
Socket Size   Request Resp.  Elapsed Trans.   CPU    CPU    S.dem   S.dem
Send   Recv   Size    Size   Time    Rate     local  remote local   remote
bytes  bytes  bytes   bytes  secs.   per sec  % S    % S    us/Tr   us/Tr

262144 540000 70000   70000  10.00   6591.45  0.86   1.34   62.490  97.446
262144 540000

After: (enabling bigger TSO/GRO packets)

ip link set dev eth0 gso_max_size 185000 gro_max_size 185000

netperf -H lpaa18 -t TCP_RR -T2,2 -l 10 -Cc -- -r 70000,70000
MIGRATED TCP REQUEST/RESPONSE TEST from ::0 (::) port 0 AF_INET6 to lpaa18.prod.google.com () port 0 AF_INET6 : first burst 0 : cpu bind
Local /Remote
Socket Size   Request Resp.  Elapsed Trans.   CPU    CPU    S.dem   S.dem
Send   Recv   Size    Size   Time    Rate     local  remote local   remote
bytes  bytes  bytes   bytes  secs.   per sec  % S    % S    us/Tr   us/Tr

262144 540000 70000   70000  10.00   8383.95  0.95   1.01   54.432  57.584
262144 540000

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Reviewed-by: default avatarTariq Toukan <tariqt@nvidia.com>
Acked-by: default avatarAlexander Duyck <alexanderduyck@fb.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent d406099d

drivers/net/ethernet/mellanox/mlx4/en_netdev.c

+3 −0
Original line number Diff line number Diff line
@@ -3417,6 +3417,9 @@ int mlx4_en_init_netdev(struct mlx4_en_dev *mdev, int port, 
	dev->min_mtu = ETH_MIN_MTU;

	dev->max_mtu = priv->max_mtu;



	/* supports LSOv2 packets. */

	netif_set_tso_max_size(dev, GSO_MAX_SIZE);



	mdev->pndev[port] = dev;

	mdev->upper[port] = NULL;

drivers/net/ethernet/mellanox/mlx4/en_tx.c

+38 −9
Original line number Diff line number Diff line
@@ -43,6 +43,7 @@ 
#include <linux/ip.h>

#include <linux/ipv6.h>

#include <linux/indirect_call_wrapper.h>

#include <net/ipv6.h>



#include "mlx4_en.h"
@@ -634,19 +635,28 @@ static int get_real_size(const struct sk_buff *skb, 
			 struct net_device *dev,

			 int *lso_header_size,

			 bool *inline_ok,

			 void **pfrag)

			 void **pfrag,

			 int *hopbyhop)

{

	struct mlx4_en_priv *priv = netdev_priv(dev);

	int real_size;



	if (shinfo->gso_size) {

		*inline_ok = false;

		if (skb->encapsulation)

		*hopbyhop = 0;

		if (skb->encapsulation) {

			*lso_header_size = (skb_inner_transport_header(skb) - skb->data) + inner_tcp_hdrlen(skb);

		else

		} else {

			/* Detects large IPV6 TCP packets and prepares for removal of

			 * HBH header that has been pushed by ip6_xmit(),

			 * mainly so that tcpdump can dissect them.

			 */

			if (ipv6_has_hopopt_jumbo(skb))

				*hopbyhop = sizeof(struct hop_jumbo_hdr);

			*lso_header_size = skb_transport_offset(skb) + tcp_hdrlen(skb);

		}

		real_size = CTRL_SIZE + shinfo->nr_frags * DS_SIZE +

			ALIGN(*lso_header_size + 4, DS_SIZE);

			ALIGN(*lso_header_size - *hopbyhop + 4, DS_SIZE);

		if (unlikely(*lso_header_size != skb_headlen(skb))) {

			/* We add a segment for the skb linear buffer only if

			 * it contains data */
@@ -873,6 +883,7 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev) 
	int desc_size;

	int real_size;

	u32 index, bf_index;

	struct ipv6hdr *h6;

	__be32 op_own;

	int lso_header_size;

	void *fragptr = NULL;
@@ -881,6 +892,7 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev) 
	bool stop_queue;

	bool inline_ok;

	u8 data_offset;

	int hopbyhop;

	bool bf_ok;



	tx_ind = skb_get_queue_mapping(skb);
@@ -890,7 +902,7 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev) 
		goto tx_drop;



	real_size = get_real_size(skb, shinfo, dev, &lso_header_size,

				  &inline_ok, &fragptr);

				  &inline_ok, &fragptr, &hopbyhop);

	if (unlikely(!real_size))

		goto tx_drop_count;
@@ -943,7 +955,7 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev) 
		data = &tx_desc->data;

		data_offset = offsetof(struct mlx4_en_tx_desc, data);

	} else {

		int lso_align = ALIGN(lso_header_size + 4, DS_SIZE);

		int lso_align = ALIGN(lso_header_size - hopbyhop + 4, DS_SIZE);



		data = (void *)&tx_desc->lso + lso_align;

		data_offset = offsetof(struct mlx4_en_tx_desc, lso) + lso_align;
@@ -1008,14 +1020,31 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev) 
			((ring->prod & ring->size) ?

				cpu_to_be32(MLX4_EN_BIT_DESC_OWN) : 0);



		lso_header_size -= hopbyhop;

		/* Fill in the LSO prefix */

		tx_desc->lso.mss_hdr_size = cpu_to_be32(

			shinfo->gso_size << 16 | lso_header_size);





		if (unlikely(hopbyhop)) {

			/* remove the HBH header.

			 * Layout: [Ethernet header][IPv6 header][HBH][TCP header]

			 */

			memcpy(tx_desc->lso.header, skb->data, ETH_HLEN + sizeof(*h6));

			h6 = (struct ipv6hdr *)((char *)tx_desc->lso.header + ETH_HLEN);

			h6->nexthdr = IPPROTO_TCP;

			/* Copy the TCP header after the IPv6 one */

			memcpy(h6 + 1,

			       skb->data + ETH_HLEN + sizeof(*h6) +

					sizeof(struct hop_jumbo_hdr),

			       tcp_hdrlen(skb));

			/* Leave ipv6 payload_len set to 0, as LSO v2 specs request. */

		} else {

			/* Copy headers;

		 * note that we already verified that it is linear */

			 * note that we already verified that it is linear

			 */

			memcpy(tx_desc->lso.header, skb->data, lso_header_size);



		}

		ring->tso_packets++;



		i = shinfo->gso_segs;