2
0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-21 11:44:01 +08:00
linux-next/include/linux/if.h
Eric Dumazet 93f154b594 net: release dst entry in dev_hard_start_xmit()
One point of contention in high network loads is the dst_release() performed
when a transmited skb is freed. This is because NIC tx completion calls
dev_kree_skb() long after original call to dev_queue_xmit(skb).

CPU cache is cold and the atomic op in dst_release() stalls. On SMP, this is
quite visible if one CPU is 100% handling softirqs for a network device,
since dst_clone() is done by other cpus, involving cache line ping pongs.

It seems right place to release dst is in dev_hard_start_xmit(), for most
devices but ones that are virtual, and some exceptions.

David Miller suggested to define a new device flag, set in alloc_netdev_mq()
(so that most devices set it at init time), and carefuly unset in devices
which dont want a NULL skb->dst in their ndo_start_xmit().

List of devices that must clear this flag is :

- loopback device, because it calls netif_rx() and quoting Patrick :
    "ip_route_input() doesn't accept loopback addresses, so loopback packets
     already need to have a dst_entry attached."
- appletalk/ipddp.c : needs skb->dst in its xmit function

- And all devices that call again dev_queue_xmit() from their xmit function
(as some classifiers need skb->dst) : bonding, vlan, macvlan, eql, ifb, hdlc_fr

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-05-18 22:19:19 -07:00

227 lines
7.8 KiB
C

/*
* INET An implementation of the TCP/IP protocol suite for the LINUX
* operating system. INET is implemented using the BSD Socket
* interface as the means of communication with the user level.
*
* Global definitions for the INET interface module.
*
* Version: @(#)if.h 1.0.2 04/18/93
*
* Authors: Original taken from Berkeley UNIX 4.3, (c) UCB 1982-1988
* Ross Biro
* Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
*
* 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 of the License, or (at your option) any later version.
*/
#ifndef _LINUX_IF_H
#define _LINUX_IF_H
#include <linux/types.h> /* for "__kernel_caddr_t" et al */
#include <linux/socket.h> /* for "struct sockaddr" et al */
#include <linux/compiler.h> /* for "__user" et al */
#define IFNAMSIZ 16
#define IFALIASZ 256
#include <linux/hdlc/ioctl.h>
/* Standard interface flags (netdevice->flags). */
#define IFF_UP 0x1 /* interface is up */
#define IFF_BROADCAST 0x2 /* broadcast address valid */
#define IFF_DEBUG 0x4 /* turn on debugging */
#define IFF_LOOPBACK 0x8 /* is a loopback net */
#define IFF_POINTOPOINT 0x10 /* interface is has p-p link */
#define IFF_NOTRAILERS 0x20 /* avoid use of trailers */
#define IFF_RUNNING 0x40 /* interface RFC2863 OPER_UP */
#define IFF_NOARP 0x80 /* no ARP protocol */
#define IFF_PROMISC 0x100 /* receive all packets */
#define IFF_ALLMULTI 0x200 /* receive all multicast packets*/
#define IFF_MASTER 0x400 /* master of a load balancer */
#define IFF_SLAVE 0x800 /* slave of a load balancer */
#define IFF_MULTICAST 0x1000 /* Supports multicast */
#define IFF_PORTSEL 0x2000 /* can set media type */
#define IFF_AUTOMEDIA 0x4000 /* auto media select active */
#define IFF_DYNAMIC 0x8000 /* dialup device with changing addresses*/
#define IFF_LOWER_UP 0x10000 /* driver signals L1 up */
#define IFF_DORMANT 0x20000 /* driver signals dormant */
#define IFF_ECHO 0x40000 /* echo sent packets */
#define IFF_VOLATILE (IFF_LOOPBACK|IFF_POINTOPOINT|IFF_BROADCAST|IFF_ECHO|\
IFF_MASTER|IFF_SLAVE|IFF_RUNNING|IFF_LOWER_UP|IFF_DORMANT)
/* Private (from user) interface flags (netdevice->priv_flags). */
#define IFF_802_1Q_VLAN 0x1 /* 802.1Q VLAN device. */
#define IFF_EBRIDGE 0x2 /* Ethernet bridging device. */
#define IFF_SLAVE_INACTIVE 0x4 /* bonding slave not the curr. active */
#define IFF_MASTER_8023AD 0x8 /* bonding master, 802.3ad. */
#define IFF_MASTER_ALB 0x10 /* bonding master, balance-alb. */
#define IFF_BONDING 0x20 /* bonding master or slave */
#define IFF_SLAVE_NEEDARP 0x40 /* need ARPs for validation */
#define IFF_ISATAP 0x80 /* ISATAP interface (RFC4214) */
#define IFF_MASTER_ARPMON 0x100 /* bonding master, ARP mon in use */
#define IFF_WAN_HDLC 0x200 /* WAN HDLC device */
#define IFF_XMIT_DST_RELEASE 0x400 /* dev_hard_start_xmit() is allowed to
* release skb->dst
*/
#define IF_GET_IFACE 0x0001 /* for querying only */
#define IF_GET_PROTO 0x0002
/* For definitions see hdlc.h */
#define IF_IFACE_V35 0x1000 /* V.35 serial interface */
#define IF_IFACE_V24 0x1001 /* V.24 serial interface */
#define IF_IFACE_X21 0x1002 /* X.21 serial interface */
#define IF_IFACE_T1 0x1003 /* T1 telco serial interface */
#define IF_IFACE_E1 0x1004 /* E1 telco serial interface */
#define IF_IFACE_SYNC_SERIAL 0x1005 /* can't be set by software */
#define IF_IFACE_X21D 0x1006 /* X.21 Dual Clocking (FarSite) */
/* For definitions see hdlc.h */
#define IF_PROTO_HDLC 0x2000 /* raw HDLC protocol */
#define IF_PROTO_PPP 0x2001 /* PPP protocol */
#define IF_PROTO_CISCO 0x2002 /* Cisco HDLC protocol */
#define IF_PROTO_FR 0x2003 /* Frame Relay protocol */
#define IF_PROTO_FR_ADD_PVC 0x2004 /* Create FR PVC */
#define IF_PROTO_FR_DEL_PVC 0x2005 /* Delete FR PVC */
#define IF_PROTO_X25 0x2006 /* X.25 */
#define IF_PROTO_HDLC_ETH 0x2007 /* raw HDLC, Ethernet emulation */
#define IF_PROTO_FR_ADD_ETH_PVC 0x2008 /* Create FR Ethernet-bridged PVC */
#define IF_PROTO_FR_DEL_ETH_PVC 0x2009 /* Delete FR Ethernet-bridged PVC */
#define IF_PROTO_FR_PVC 0x200A /* for reading PVC status */
#define IF_PROTO_FR_ETH_PVC 0x200B
#define IF_PROTO_RAW 0x200C /* RAW Socket */
/* RFC 2863 operational status */
enum {
IF_OPER_UNKNOWN,
IF_OPER_NOTPRESENT,
IF_OPER_DOWN,
IF_OPER_LOWERLAYERDOWN,
IF_OPER_TESTING,
IF_OPER_DORMANT,
IF_OPER_UP,
};
/* link modes */
enum {
IF_LINK_MODE_DEFAULT,
IF_LINK_MODE_DORMANT, /* limit upward transition to dormant */
};
/*
* Device mapping structure. I'd just gone off and designed a
* beautiful scheme using only loadable modules with arguments
* for driver options and along come the PCMCIA people 8)
*
* Ah well. The get() side of this is good for WDSETUP, and it'll
* be handy for debugging things. The set side is fine for now and
* being very small might be worth keeping for clean configuration.
*/
struct ifmap
{
unsigned long mem_start;
unsigned long mem_end;
unsigned short base_addr;
unsigned char irq;
unsigned char dma;
unsigned char port;
/* 3 bytes spare */
};
struct if_settings
{
unsigned int type; /* Type of physical device or protocol */
unsigned int size; /* Size of the data allocated by the caller */
union {
/* {atm/eth/dsl}_settings anyone ? */
raw_hdlc_proto __user *raw_hdlc;
cisco_proto __user *cisco;
fr_proto __user *fr;
fr_proto_pvc __user *fr_pvc;
fr_proto_pvc_info __user *fr_pvc_info;
/* interface settings */
sync_serial_settings __user *sync;
te1_settings __user *te1;
} ifs_ifsu;
};
/*
* Interface request structure used for socket
* ioctl's. All interface ioctl's must have parameter
* definitions which begin with ifr_name. The
* remainder may be interface specific.
*/
struct ifreq
{
#define IFHWADDRLEN 6
union
{
char ifrn_name[IFNAMSIZ]; /* if name, e.g. "en0" */
} ifr_ifrn;
union {
struct sockaddr ifru_addr;
struct sockaddr ifru_dstaddr;
struct sockaddr ifru_broadaddr;
struct sockaddr ifru_netmask;
struct sockaddr ifru_hwaddr;
short ifru_flags;
int ifru_ivalue;
int ifru_mtu;
struct ifmap ifru_map;
char ifru_slave[IFNAMSIZ]; /* Just fits the size */
char ifru_newname[IFNAMSIZ];
void __user * ifru_data;
struct if_settings ifru_settings;
} ifr_ifru;
};
#define ifr_name ifr_ifrn.ifrn_name /* interface name */
#define ifr_hwaddr ifr_ifru.ifru_hwaddr /* MAC address */
#define ifr_addr ifr_ifru.ifru_addr /* address */
#define ifr_dstaddr ifr_ifru.ifru_dstaddr /* other end of p-p lnk */
#define ifr_broadaddr ifr_ifru.ifru_broadaddr /* broadcast address */
#define ifr_netmask ifr_ifru.ifru_netmask /* interface net mask */
#define ifr_flags ifr_ifru.ifru_flags /* flags */
#define ifr_metric ifr_ifru.ifru_ivalue /* metric */
#define ifr_mtu ifr_ifru.ifru_mtu /* mtu */
#define ifr_map ifr_ifru.ifru_map /* device map */
#define ifr_slave ifr_ifru.ifru_slave /* slave device */
#define ifr_data ifr_ifru.ifru_data /* for use by interface */
#define ifr_ifindex ifr_ifru.ifru_ivalue /* interface index */
#define ifr_bandwidth ifr_ifru.ifru_ivalue /* link bandwidth */
#define ifr_qlen ifr_ifru.ifru_ivalue /* Queue length */
#define ifr_newname ifr_ifru.ifru_newname /* New name */
#define ifr_settings ifr_ifru.ifru_settings /* Device/proto settings*/
/*
* Structure used in SIOCGIFCONF request.
* Used to retrieve interface configuration
* for machine (useful for programs which
* must know all networks accessible).
*/
struct ifconf
{
int ifc_len; /* size of buffer */
union
{
char __user *ifcu_buf;
struct ifreq __user *ifcu_req;
} ifc_ifcu;
};
#define ifc_buf ifc_ifcu.ifcu_buf /* buffer address */
#define ifc_req ifc_ifcu.ifcu_req /* array of structures */
#endif /* _LINUX_IF_H */