From 71c87e0cedca843162206c698cfa02e5fea9e2e3 Mon Sep 17 00:00:00 2001 From: Jan-Bernd Themann Date: Wed, 8 Aug 2007 22:38:05 -0700 Subject: [NET]: Generic Large Receive Offload for TCP traffic This patch provides generic Large Receive Offload (LRO) functionality for IPv4/TCP traffic. LRO combines received tcp packets to a single larger tcp packet and passes them then to the network stack in order to increase performance (throughput). The interface supports two modes: Drivers can either pass SKBs or fragment lists to the LRO engine. Signed-off-by: Jan-Bernd Themann Signed-off-by: David S. Miller --- include/linux/inet_lro.h | 177 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 177 insertions(+) create mode 100644 include/linux/inet_lro.h (limited to 'include/linux') diff --git a/include/linux/inet_lro.h b/include/linux/inet_lro.h new file mode 100644 index 000000000000..e1fc1d16d3cd --- /dev/null +++ b/include/linux/inet_lro.h @@ -0,0 +1,177 @@ +/* + * linux/include/linux/inet_lro.h + * + * Large Receive Offload (ipv4 / tcp) + * + * (C) Copyright IBM Corp. 2007 + * + * Authors: + * Jan-Bernd Themann + * Christoph Raisch + * + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2, or (at your option) + * any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#ifndef __INET_LRO_H_ +#define __INET_LRO_H_ + +#include +#include + +/* + * LRO statistics + */ + +struct net_lro_stats { + unsigned long aggregated; + unsigned long flushed; + unsigned long no_desc; +}; + +/* + * LRO descriptor for a tcp session + */ +struct net_lro_desc { + struct sk_buff *parent; + struct sk_buff *last_skb; + struct skb_frag_struct *next_frag; + struct iphdr *iph; + struct tcphdr *tcph; + struct vlan_group *vgrp; + __wsum data_csum; + u32 tcp_rcv_tsecr; + u32 tcp_rcv_tsval; + u32 tcp_ack; + u32 tcp_next_seq; + u32 skb_tot_frags_len; + u16 ip_tot_len; + u16 tcp_saw_tstamp; /* timestamps enabled */ + u16 tcp_window; + u16 vlan_tag; + int pkt_aggr_cnt; /* counts aggregated packets */ + int vlan_packet; + int mss; + int active; +}; + +/* + * Large Receive Offload (LRO) Manager + * + * Fields must be set by driver + */ + +struct net_lro_mgr { + struct net_device *dev; + struct net_lro_stats stats; + + /* LRO features */ + unsigned long features; +#define LRO_F_NAPI 1 /* Pass packets to stack via NAPI */ +#define LRO_F_EXTRACT_VLAN_ID 2 /* Set flag if VLAN IDs are extracted + from received packets and eth protocol + is still ETH_P_8021Q */ + + u32 ip_summed; /* Set in non generated SKBs in page mode */ + u32 ip_summed_aggr; /* Set in aggregated SKBs: CHECKSUM_UNNECESSARY + * or CHECKSUM_NONE */ + + int max_desc; /* Max number of LRO descriptors */ + int max_aggr; /* Max number of LRO packets to be aggregated */ + + struct net_lro_desc *lro_arr; /* Array of LRO descriptors */ + + /* + * Optimized driver functions + * + * get_skb_header: returns tcp and ip header for packet in SKB + */ + int (*get_skb_header)(struct sk_buff *skb, void **ip_hdr, + void **tcpudp_hdr, u64 *hdr_flags, void *priv); + + /* hdr_flags: */ +#define LRO_IPV4 1 /* ip_hdr is IPv4 header */ +#define LRO_TCP 2 /* tcpudp_hdr is TCP header */ + + /* + * get_frag_header: returns mac, tcp and ip header for packet in SKB + * + * @hdr_flags: Indicate what kind of LRO has to be done + * (IPv4/IPv6/TCP/UDP) + */ + int (*get_frag_header)(struct skb_frag_struct *frag, void **mac_hdr, + void **ip_hdr, void **tcpudp_hdr, u64 *hdr_flags, + void *priv); +}; + +/* + * Processes a SKB + * + * @lro_mgr: LRO manager to use + * @skb: SKB to aggregate + * @priv: Private data that may be used by driver functions + * (for example get_tcp_ip_hdr) + */ + +void lro_receive_skb(struct net_lro_mgr *lro_mgr, + struct sk_buff *skb, + void *priv); + +/* + * Processes a SKB with VLAN HW acceleration support + */ + +void lro_vlan_hwaccel_receive_skb(struct net_lro_mgr *lro_mgr, + struct sk_buff *skb, + struct vlan_group *vgrp, + u16 vlan_tag, + void *priv); + +/* + * Processes a fragment list + * + * This functions aggregate fragments and generate SKBs do pass + * the packets to the stack. + * + * @lro_mgr: LRO manager to use + * @frags: Fragment to be processed. Must contain entire header in first + * element. + * @len: Length of received data + * @true_size: Actual size of memory the fragment is consuming + * @priv: Private data that may be used by driver functions + * (for example get_tcp_ip_hdr) + */ + +void lro_receive_frags(struct net_lro_mgr *lro_mgr, + struct skb_frag_struct *frags, + int len, int true_size, void *priv, __wsum sum); + +void lro_vlan_hwaccel_receive_frags(struct net_lro_mgr *lro_mgr, + struct skb_frag_struct *frags, + int len, int true_size, + struct vlan_group *vgrp, + u16 vlan_tag, + void *priv, __wsum sum); + +/* + * Forward all aggregated SKBs held by lro_mgr to network stack + */ + +void lro_flush_all(struct net_lro_mgr *lro_mgr); + +void lro_flush_pkt(struct net_lro_mgr *lro_mgr, + struct iphdr *iph, struct tcphdr *tcph); + +#endif -- cgit v1.2.3