[NET] loopback: minor statistics optimization
The loopback device status structure is a singleton and doesn't
need to be allocated. Add ethtool_ops hooks to show checksum always on,
and make ethtool_ops const.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/loopback.c b/drivers/net/loopback.c
index f429b19..4178b4b1 100644
--- a/drivers/net/loopback.c
+++ b/drivers/net/loopback.c
@@ -161,15 +161,13 @@
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;
int i;
- if (!stats) {
- return NULL;
- }
-
memset(stats, 0, sizeof(struct net_device_stats));
for_each_possible_cpu(i) {
@@ -185,19 +183,28 @@
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,
@@ -221,16 +228,6 @@
/* Setup and register the loopback device. */
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);
};