kernel-ark/net/atm/pvc.c
Eric Dumazet 90ddc4f047 [NET]: move struct proto_ops to const
I noticed that some of 'struct proto_ops' used in the kernel may share
a cache line used by locks or other heavily modified data. (default
linker alignement is 32 bytes, and L1_CACHE_LINE is 64 or 128 at
least)

This patch makes sure a 'struct proto_ops' can be declared as const,
so that all cpus can share all parts of it without false sharing.

This is not mandatory : a driver can still use a read/write structure
if it needs to (and eventually a __read_mostly)

I made a global stubstitute to change all existing occurences to make
them const.

This should reduce the possibility of false sharing on SMP, and
speedup some socket system calls.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-01-03 13:11:15 -08:00

156 lines
3.5 KiB
C

/* net/atm/pvc.c - ATM PVC sockets */
/* Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA */
#include <linux/config.h>
#include <linux/net.h> /* struct socket, struct proto_ops */
#include <linux/atm.h> /* ATM stuff */
#include <linux/atmdev.h> /* ATM devices */
#include <linux/errno.h> /* error codes */
#include <linux/kernel.h> /* printk */
#include <linux/init.h>
#include <linux/skbuff.h>
#include <linux/bitops.h>
#include <net/sock.h> /* for sock_no_* */
#include "resources.h" /* devs and vccs */
#include "common.h" /* common for PVCs and SVCs */
static int pvc_shutdown(struct socket *sock,int how)
{
return 0;
}
static int pvc_bind(struct socket *sock,struct sockaddr *sockaddr,
int sockaddr_len)
{
struct sock *sk = sock->sk;
struct sockaddr_atmpvc *addr;
struct atm_vcc *vcc;
int error;
if (sockaddr_len != sizeof(struct sockaddr_atmpvc)) return -EINVAL;
addr = (struct sockaddr_atmpvc *) sockaddr;
if (addr->sap_family != AF_ATMPVC) return -EAFNOSUPPORT;
lock_sock(sk);
vcc = ATM_SD(sock);
if (!test_bit(ATM_VF_HASQOS, &vcc->flags)) {
error = -EBADFD;
goto out;
}
if (test_bit(ATM_VF_PARTIAL,&vcc->flags)) {
if (vcc->vpi != ATM_VPI_UNSPEC) addr->sap_addr.vpi = vcc->vpi;
if (vcc->vci != ATM_VCI_UNSPEC) addr->sap_addr.vci = vcc->vci;
}
error = vcc_connect(sock, addr->sap_addr.itf, addr->sap_addr.vpi,
addr->sap_addr.vci);
out:
release_sock(sk);
return error;
}
static int pvc_connect(struct socket *sock,struct sockaddr *sockaddr,
int sockaddr_len,int flags)
{
return pvc_bind(sock,sockaddr,sockaddr_len);
}
static int pvc_setsockopt(struct socket *sock, int level, int optname,
char __user *optval, int optlen)
{
struct sock *sk = sock->sk;
int error;
lock_sock(sk);
error = vcc_setsockopt(sock, level, optname, optval, optlen);
release_sock(sk);
return error;
}
static int pvc_getsockopt(struct socket *sock, int level, int optname,
char __user *optval, int __user *optlen)
{
struct sock *sk = sock->sk;
int error;
lock_sock(sk);
error = vcc_getsockopt(sock, level, optname, optval, optlen);
release_sock(sk);
return error;
}
static int pvc_getname(struct socket *sock,struct sockaddr *sockaddr,
int *sockaddr_len,int peer)
{
struct sockaddr_atmpvc *addr;
struct atm_vcc *vcc = ATM_SD(sock);
if (!vcc->dev || !test_bit(ATM_VF_ADDR,&vcc->flags)) return -ENOTCONN;
*sockaddr_len = sizeof(struct sockaddr_atmpvc);
addr = (struct sockaddr_atmpvc *) sockaddr;
addr->sap_family = AF_ATMPVC;
addr->sap_addr.itf = vcc->dev->number;
addr->sap_addr.vpi = vcc->vpi;
addr->sap_addr.vci = vcc->vci;
return 0;
}
static const struct proto_ops pvc_proto_ops = {
.family = PF_ATMPVC,
.owner = THIS_MODULE,
.release = vcc_release,
.bind = pvc_bind,
.connect = pvc_connect,
.socketpair = sock_no_socketpair,
.accept = sock_no_accept,
.getname = pvc_getname,
.poll = vcc_poll,
.ioctl = vcc_ioctl,
.listen = sock_no_listen,
.shutdown = pvc_shutdown,
.setsockopt = pvc_setsockopt,
.getsockopt = pvc_getsockopt,
.sendmsg = vcc_sendmsg,
.recvmsg = vcc_recvmsg,
.mmap = sock_no_mmap,
.sendpage = sock_no_sendpage,
};
static int pvc_create(struct socket *sock,int protocol)
{
sock->ops = &pvc_proto_ops;
return vcc_create(sock, protocol, PF_ATMPVC);
}
static struct net_proto_family pvc_family_ops = {
.family = PF_ATMPVC,
.create = pvc_create,
.owner = THIS_MODULE,
};
/*
* Initialize the ATM PVC protocol family
*/
int __init atmpvc_init(void)
{
return sock_register(&pvc_family_ops);
}
void atmpvc_exit(void)
{
sock_unregister(PF_ATMPVC);
}