#include <linux/tcp.h>
#include <linux/percpu.h>
-static DEFINE_PER_CPU(struct net_device_stats, loopback_stats);
+struct pcpu_lstats {
+ unsigned long packets;
+ unsigned long bytes;
+};
+static DEFINE_PER_CPU(struct pcpu_lstats, pcpu_lstats);
#define LOOPBACK_OVERHEAD (128 + MAX_HEADER + 16 + 16)
*/
static int loopback_xmit(struct sk_buff *skb, struct net_device *dev)
{
- struct net_device_stats *lb_stats;
+ struct pcpu_lstats *lb_stats;
skb_orphan(skb);
#endif
dev->last_rx = jiffies;
- lb_stats = &per_cpu(loopback_stats, get_cpu());
- lb_stats->rx_bytes += skb->len;
- lb_stats->tx_bytes = lb_stats->rx_bytes;
- lb_stats->rx_packets++;
- lb_stats->tx_packets = lb_stats->rx_packets;
- put_cpu();
+ /* it's OK to use __get_cpu_var() because BHs are off */
+ lb_stats = &__get_cpu_var(pcpu_lstats);
+ lb_stats->bytes += skb->len;
+ lb_stats->packets++;
netif_rx(skb);
- return(0);
+ return 0;
}
+static struct net_device_stats loopback_stats;
+
static struct net_device_stats *get_stats(struct net_device *dev)
{
- struct net_device_stats *stats = dev->priv;
+ struct net_device_stats *stats = &loopback_stats;
+ unsigned long bytes = 0;
+ unsigned long packets = 0;
int i;
- if (!stats) {
- return NULL;
- }
-
- memset(stats, 0, sizeof(struct net_device_stats));
-
for_each_possible_cpu(i) {
- struct net_device_stats *lb_stats;
+ const struct pcpu_lstats *lb_stats;
- lb_stats = &per_cpu(loopback_stats, i);
- stats->rx_bytes += lb_stats->rx_bytes;
- stats->tx_bytes += lb_stats->tx_bytes;
- stats->rx_packets += lb_stats->rx_packets;
- stats->tx_packets += lb_stats->tx_packets;
+ lb_stats = &per_cpu(pcpu_lstats, i);
+ bytes += lb_stats->bytes;
+ packets += lb_stats->packets;
}
-
+ stats->rx_packets = packets;
+ stats->tx_packets = packets;
+ stats->rx_bytes = bytes;
+ stats->tx_bytes = bytes;
return stats;
}
-static u32 loopback_get_link(struct net_device *dev)
+static u32 always_on(struct net_device *dev)
{
return 1;
}
static const struct ethtool_ops loopback_ethtool_ops = {
- .get_link = loopback_get_link,
+ .get_link = always_on,
.get_tso = ethtool_op_get_tso,
.set_tso = ethtool_op_set_tso,
+ .get_tx_csum = always_on,
+ .get_sg = always_on,
+ .get_rx_csum = always_on,
};
+/*
+ * The loopback device is special. There is only one instance and
+ * it is statically allocated. Don't do this for other devices.
+ */
struct net_device loopback_dev = {
.name = "lo",
+ .get_stats = &get_stats,
+ .priv = &loopback_stats,
.mtu = (16 * 1024) + 20 + 20 + 12,
.hard_start_xmit = loopback_xmit,
.hard_header = eth_header,
};
/* Setup and register the loopback device. */
-int __init loopback_init(void)
+static int __init loopback_init(void)
{
- struct net_device_stats *stats;
-
- /* Can survive without statistics */
- stats = kmalloc(sizeof(struct net_device_stats), GFP_KERNEL);
- if (stats) {
- memset(stats, 0, sizeof(struct net_device_stats));
- loopback_dev.priv = stats;
- loopback_dev.get_stats = &get_stats;
- }
-
return register_netdev(&loopback_dev);
};
+module_init(loopback_init);
+
EXPORT_SYMBOL(loopback_dev);