Merge branch 'eth_proto_is_802_3'
Alexander Duyck says:
====================
Add eth_proto_is_802_3 to provide improved means of checking Ethertype
This patch series implements and makes use of eth_proto_is_802_3(). The
idea behind the function is to provide an optimized means of testing to
determine if a given Ethertype value is a length or 802.3 protocol number.
The standard path for this was to use ntohs(proto) and then perform a
comparison. This adds a slight cost as it usually requires either a 16b
rotate or byte swap which can cost 1 cycle or more depending on the
processor.
I had previously addressed this for eth_type_trans, however in doing so I had
overlooked checking with sparse and had introduced a couple sparse warnings.
The first patch in this series fixes those sparse warnings as well as does
some additional optimization for big endian systems. In addition it pushes
the code out into a separate function which can then be used in the other
patches to reduce the instruction count/processing time in those functions
as well.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/etherdevice.h b/include/linux/etherdevice.h
index c4a10f9..9012f87 100644
--- a/include/linux/etherdevice.h
+++ b/include/linux/etherdevice.h
@@ -191,6 +191,24 @@
}
/**
+ * eth_proto_is_802_3 - Determine if a given Ethertype/length is a protocol
+ * @proto: Ethertype/length value to be tested
+ *
+ * Check that the value from the Ethertype/length field is a valid Ethertype.
+ *
+ * Return true if the valid is an 802.3 supported Ethertype.
+ */
+static inline bool eth_proto_is_802_3(__be16 proto)
+{
+#ifndef __BIG_ENDIAN
+ /* if CPU is little endian mask off bits representing LSB */
+ proto &= htons(0xFF00);
+#endif
+ /* cast both to u16 and compare since LSB can be ignored */
+ return (__force u16)proto >= (__force u16)htons(ETH_P_802_3_MIN);
+}
+
+/**
* eth_random_addr - Generate software assigned random Ethernet address
* @addr: Pointer to a six-byte array containing the Ethernet address
*
diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h
index 920e445..b9ab677 100644
--- a/include/linux/if_vlan.h
+++ b/include/linux/if_vlan.h
@@ -539,7 +539,7 @@
*/
proto = vhdr->h_vlan_encapsulated_proto;
- if (ntohs(proto) >= ETH_P_802_3_MIN) {
+ if (eth_proto_is_802_3(proto)) {
skb->protocol = proto;
return;
}
diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c
index 91180a7..5149d9e 100644
--- a/net/bridge/netfilter/ebtables.c
+++ b/net/bridge/netfilter/ebtables.c
@@ -139,7 +139,7 @@
ethproto = h->h_proto;
if (e->bitmask & EBT_802_3) {
- if (FWINV2(ntohs(ethproto) >= ETH_P_802_3_MIN, EBT_IPROTO))
+ if (FWINV2(eth_proto_is_802_3(ethproto), EBT_IPROTO))
return 1;
} else if (!(e->bitmask & EBT_NOPROTO) &&
FWINV2(e->ethproto != ethproto, EBT_IPROTO))
diff --git a/net/ethernet/eth.c b/net/ethernet/eth.c
index 314e4c5..9045e2a 100644
--- a/net/ethernet/eth.c
+++ b/net/ethernet/eth.c
@@ -179,7 +179,7 @@
if (unlikely(netdev_uses_dsa(dev)))
return htons(ETH_P_XDSA);
- if (likely((eth->h_proto & htons(0xFF00)) >= htons(ETH_P_802_3_MIN)))
+ if (likely(eth_proto_is_802_3(eth->h_proto)))
return eth->h_proto;
/*
diff --git a/net/ipv4/ip_tunnel_core.c b/net/ipv4/ip_tunnel_core.c
index ce63ab2..3998b18 100644
--- a/net/ipv4/ip_tunnel_core.c
+++ b/net/ipv4/ip_tunnel_core.c
@@ -98,7 +98,7 @@
return -ENOMEM;
eh = (struct ethhdr *)skb->data;
- if (likely(ntohs(eh->h_proto) >= ETH_P_802_3_MIN))
+ if (likely(eth_proto_is_802_3(eh->h_proto)))
skb->protocol = eh->h_proto;
else
skb->protocol = htons(ETH_P_802_2);
diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index 096c627..3b90461 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -545,7 +545,7 @@
/* Normally, setting the skb 'protocol' field would be handled by a
* call to eth_type_trans(), but it assumes there's a sending
* device, which we may not have. */
- if (ntohs(eth->h_proto) >= ETH_P_802_3_MIN)
+ if (eth_proto_is_802_3(eth->h_proto))
packet->protocol = eth->h_proto;
else
packet->protocol = htons(ETH_P_802_2);
diff --git a/net/openvswitch/flow.c b/net/openvswitch/flow.c
index 2dacc7b..bc7b0ab 100644
--- a/net/openvswitch/flow.c
+++ b/net/openvswitch/flow.c
@@ -332,7 +332,7 @@
proto = *(__be16 *) skb->data;
__skb_pull(skb, sizeof(__be16));
- if (ntohs(proto) >= ETH_P_802_3_MIN)
+ if (eth_proto_is_802_3(proto))
return proto;
if (skb->len < sizeof(struct llc_snap_hdr))
@@ -349,7 +349,7 @@
__skb_pull(skb, sizeof(struct llc_snap_hdr));
- if (ntohs(llc->ethertype) >= ETH_P_802_3_MIN)
+ if (eth_proto_is_802_3(llc->ethertype))
return llc->ethertype;
return htons(ETH_P_802_2);
diff --git a/net/openvswitch/flow_netlink.c b/net/openvswitch/flow_netlink.c
index c691b1a..624e41c 100644
--- a/net/openvswitch/flow_netlink.c
+++ b/net/openvswitch/flow_netlink.c
@@ -816,7 +816,7 @@
if (is_mask) {
/* Always exact match EtherType. */
eth_type = htons(0xffff);
- } else if (ntohs(eth_type) < ETH_P_802_3_MIN) {
+ } else if (!eth_proto_is_802_3(eth_type)) {
OVS_NLERR(log, "EtherType %x is less than min %x",
ntohs(eth_type), ETH_P_802_3_MIN);
return -EINVAL;