Commit 23f1f4ef authored by Stephen Hemminger's avatar Stephen Hemminger Committed by David S. Miller
Browse files

[NET] ethernet: optimize memcpy and memset

The ethernet header management only needs to handle a fixed
size address (6 bytes). If the memcpy/memset are changed to
be passed a constant length, then compiler can optimize for
this case (and if it is smart eliminate string instructions).
Signed-off-by: default avatarStephen Hemminger <>
Signed-off-by: default avatarDavid S. Miller <>
parent fd21150a
......@@ -91,10 +91,10 @@ int eth_header(struct sk_buff *skb, struct net_device *dev, unsigned short type,
if (!saddr)
saddr = dev->dev_addr;
memcpy(eth->h_source, saddr, dev->addr_len);
memcpy(eth->h_source, saddr, ETH_ALEN);
if (daddr) {
memcpy(eth->h_dest, daddr, dev->addr_len);
memcpy(eth->h_dest, daddr, ETH_ALEN);
return ETH_HLEN;
......@@ -103,7 +103,7 @@ int eth_header(struct sk_buff *skb, struct net_device *dev, unsigned short type,
if (dev->flags & (IFF_LOOPBACK | IFF_NOARP)) {
memset(eth->h_dest, 0, dev->addr_len);
memset(eth->h_dest, 0, ETH_ALEN);
return ETH_HLEN;
......@@ -135,7 +135,7 @@ int eth_rebuild_header(struct sk_buff *skb)
"%s: unable to resolve type %X addresses.\n",
dev->name, (int)eth->h_proto);
memcpy(eth->h_source, dev->dev_addr, dev->addr_len);
memcpy(eth->h_source, dev->dev_addr, ETH_ALEN);
......@@ -233,8 +233,8 @@ int eth_header_cache(struct neighbour *neigh, struct hh_cache *hh)
return -1;
eth->h_proto = type;
memcpy(eth->h_source, dev->dev_addr, dev->addr_len);
memcpy(eth->h_dest, neigh->ha, dev->addr_len);
memcpy(eth->h_source, dev->dev_addr, ETH_ALEN);
memcpy(eth->h_dest, neigh->ha, ETH_ALEN);
hh->hh_len = ETH_HLEN;
return 0;
......@@ -251,7 +251,7 @@ void eth_header_cache_update(struct hh_cache *hh, struct net_device *dev,
unsigned char *haddr)
memcpy(((u8 *) hh->hh_data) + HH_DATA_OFF(sizeof(struct ethhdr)),
haddr, dev->addr_len);
haddr, ETH_ALEN);
......@@ -271,7 +271,7 @@ static int eth_mac_addr(struct net_device *dev, void *p)
return -EBUSY;
if (!is_valid_ether_addr(addr->sa_data))
memcpy(dev->dev_addr, addr->sa_data, dev->addr_len);
memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
return 0;
Supports Markdown
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment