aha/net/8021q/vlan_core.c
Eric Dumazet 9793241fe9 vlan: Precise RX stats accounting
With multi queue devices, its possible that several cpus call
vlan RX routines simultaneously for the same vlan device.

We update RX stats counter without any locking, so we can
get slightly wrong counters.

One possible fix is to use percpu counters, to get precise
accounting and also get guarantee of no cache line ping pongs
between cpus.

Note: this adds 16 bytes (32 bytes on 64bit arches) of percpu
data per vlan device.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-11-17 23:51:55 -08:00

137 lines
3.2 KiB
C

#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/if_vlan.h>
#include <linux/netpoll.h>
#include "vlan.h"
/* VLAN rx hw acceleration helper. This acts like netif_{rx,receive_skb}(). */
int __vlan_hwaccel_rx(struct sk_buff *skb, struct vlan_group *grp,
u16 vlan_tci, int polling)
{
if (netpoll_rx(skb))
return NET_RX_DROP;
if (skb_bond_should_drop(skb))
goto drop;
__vlan_hwaccel_put_tag(skb, vlan_tci);
skb->dev = vlan_group_get_device(grp, vlan_tci & VLAN_VID_MASK);
if (!skb->dev)
goto drop;
return (polling ? netif_receive_skb(skb) : netif_rx(skb));
drop:
dev_kfree_skb_any(skb);
return NET_RX_DROP;
}
EXPORT_SYMBOL(__vlan_hwaccel_rx);
int vlan_hwaccel_do_receive(struct sk_buff *skb)
{
struct net_device *dev = skb->dev;
struct vlan_rx_stats *rx_stats;
skb->dev = vlan_dev_info(dev)->real_dev;
netif_nit_deliver(skb);
skb->dev = dev;
skb->priority = vlan_get_ingress_priority(dev, skb->vlan_tci);
skb->vlan_tci = 0;
rx_stats = per_cpu_ptr(vlan_dev_info(dev)->vlan_rx_stats,
smp_processor_id());
rx_stats->rx_packets++;
rx_stats->rx_bytes += skb->len;
switch (skb->pkt_type) {
case PACKET_BROADCAST:
break;
case PACKET_MULTICAST:
rx_stats->multicast++;
break;
case PACKET_OTHERHOST:
/* Our lower layer thinks this is not local, let's make sure.
* This allows the VLAN to have a different MAC than the
* underlying device, and still route correctly. */
if (!compare_ether_addr(eth_hdr(skb)->h_dest,
dev->dev_addr))
skb->pkt_type = PACKET_HOST;
break;
};
return 0;
}
struct net_device *vlan_dev_real_dev(const struct net_device *dev)
{
return vlan_dev_info(dev)->real_dev;
}
EXPORT_SYMBOL(vlan_dev_real_dev);
u16 vlan_dev_vlan_id(const struct net_device *dev)
{
return vlan_dev_info(dev)->vlan_id;
}
EXPORT_SYMBOL(vlan_dev_vlan_id);
static gro_result_t
vlan_gro_common(struct napi_struct *napi, struct vlan_group *grp,
unsigned int vlan_tci, struct sk_buff *skb)
{
struct sk_buff *p;
if (skb_bond_should_drop(skb))
goto drop;
__vlan_hwaccel_put_tag(skb, vlan_tci);
skb->dev = vlan_group_get_device(grp, vlan_tci & VLAN_VID_MASK);
if (!skb->dev)
goto drop;
for (p = napi->gro_list; p; p = p->next) {
NAPI_GRO_CB(p)->same_flow =
p->dev == skb->dev && !compare_ether_header(
skb_mac_header(p), skb_gro_mac_header(skb));
NAPI_GRO_CB(p)->flush = 0;
}
return dev_gro_receive(napi, skb);
drop:
return GRO_DROP;
}
gro_result_t vlan_gro_receive(struct napi_struct *napi, struct vlan_group *grp,
unsigned int vlan_tci, struct sk_buff *skb)
{
if (netpoll_rx_on(skb))
return vlan_hwaccel_receive_skb(skb, grp, vlan_tci)
? GRO_DROP : GRO_NORMAL;
skb_gro_reset_offset(skb);
return napi_skb_finish(vlan_gro_common(napi, grp, vlan_tci, skb), skb);
}
EXPORT_SYMBOL(vlan_gro_receive);
gro_result_t vlan_gro_frags(struct napi_struct *napi, struct vlan_group *grp,
unsigned int vlan_tci)
{
struct sk_buff *skb = napi_frags_skb(napi);
if (!skb)
return GRO_DROP;
if (netpoll_rx_on(skb)) {
skb->protocol = eth_type_trans(skb, skb->dev);
return vlan_hwaccel_receive_skb(skb, grp, vlan_tci)
? GRO_DROP : GRO_NORMAL;
}
return napi_frags_finish(napi, skb,
vlan_gro_common(napi, grp, vlan_tci, skb));
}
EXPORT_SYMBOL(vlan_gro_frags);