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authorJan-Bernd Themann <themann@de.ibm.com>2007-08-08 22:38:05 -0700
committerDavid S. Miller <davem@sunset.davemloft.net>2007-10-10 16:47:46 -0700
commit71c87e0cedca843162206c698cfa02e5fea9e2e3 (patch)
tree8f0138754aaee3c15d1b00c4d2774b5e12da2c78 /include
parente314dbdc1c0dc6a548ecf0afce28ecfd538ff568 (diff)
downloadop-kernel-dev-71c87e0cedca843162206c698cfa02e5fea9e2e3.zip
op-kernel-dev-71c87e0cedca843162206c698cfa02e5fea9e2e3.tar.gz
[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 <themann@de.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include')
-rw-r--r--include/linux/inet_lro.h177
1 files changed, 177 insertions, 0 deletions
diff --git a/include/linux/inet_lro.h b/include/linux/inet_lro.h
new file mode 100644
index 0000000..e1fc1d1
--- /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 <themann@de.ibm.com>
+ * Christoph Raisch <raisch@de.ibm.com>
+ *
+ *
+ * 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 <net/ip.h>
+#include <net/tcp.h>
+
+/*
+ * 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
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