ar71xx: add unaligned access hacks for VXLAN
authorMatthias Schiffer <mschiffer@universe-factory.net>
Tue, 23 Jan 2018 19:52:45 +0000 (20:52 +0100)
committerMatthias Schiffer <mschiffer@universe-factory.net>
Thu, 25 Jan 2018 10:00:48 +0000 (11:00 +0100)
Gives a ~5% performance gain.

Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>
target/linux/ar71xx/patches-4.9/910-unaligned_access_hacks.patch

index 92f0a67..f26af24 100644 (file)
        };
        if (skb->ip_summed != CHECKSUM_PARTIAL) {
                *sum = csum_fold(csum_partial(diff, sizeof(diff),
+--- a/drivers/net/vxlan.c
++++ b/drivers/net/vxlan.c
+@@ -1811,15 +1811,15 @@ static int vxlan_build_skb(struct sk_buf
+               goto out_free;
+       vxh = (struct vxlanhdr *) __skb_push(skb, sizeof(*vxh));
+-      vxh->vx_flags = VXLAN_HF_VNI;
+-      vxh->vx_vni = vxlan_vni_field(vni);
++      net_hdr_word(&vxh->vx_flags) = VXLAN_HF_VNI;
++      net_hdr_word(&vxh->vx_vni) = vxlan_vni_field(vni);
+       if (type & SKB_GSO_TUNNEL_REMCSUM) {
+               unsigned int start;
+               start = skb_checksum_start_offset(skb) - sizeof(struct vxlanhdr);
+-              vxh->vx_vni |= vxlan_compute_rco(start, skb->csum_offset);
+-              vxh->vx_flags |= VXLAN_HF_RCO;
++              net_hdr_word(&vxh->vx_vni) |= vxlan_compute_rco(start, skb->csum_offset);
++              net_hdr_word(&vxh->vx_flags) |= VXLAN_HF_RCO;
+               if (!skb_is_gso(skb)) {
+                       skb->ip_summed = CHECKSUM_NONE;
+--- a/include/linux/etherdevice.h
++++ b/include/linux/etherdevice.h
+@@ -435,7 +435,7 @@ static inline bool is_etherdev_addr(cons
+  * @b: Pointer to Ethernet header
+  *
+  * Compare two Ethernet headers, returns 0 if equal.
+- * This assumes that the network header (i.e., IP header) is 4-byte
++ * This assumes that the network header (i.e., IP header) is 2-byte
+  * aligned OR the platform can handle unaligned access.  This is the
+  * case for all packets coming into netif_receive_skb or similar
+  * entry points.
+@@ -458,11 +458,12 @@ static inline unsigned long compare_ethe
+       fold |= *(unsigned long *)(a + 6) ^ *(unsigned long *)(b + 6);
+       return fold;
+ #else
+-      u32 *a32 = (u32 *)((u8 *)a + 2);
+-      u32 *b32 = (u32 *)((u8 *)b + 2);
++      const u16 *a16 = a;
++      const u16 *b16 = b;
+-      return (*(u16 *)a ^ *(u16 *)b) | (a32[0] ^ b32[0]) |
+-             (a32[1] ^ b32[1]) | (a32[2] ^ b32[2]);
++      return (a16[0] ^ b16[0]) | (a16[1] ^ b16[1]) | (a16[2] ^ b16[2]) |
++             (a16[3] ^ b16[3]) | (a16[4] ^ b16[4]) | (a16[5] ^ b16[5]) |
++             (a16[6] ^ b16[6]);
+ #endif
+ }
+--- a/net/ipv4/tcp_offload.c
++++ b/net/ipv4/tcp_offload.c
+@@ -215,7 +215,7 @@ struct sk_buff **tcp_gro_receive(struct
+               th2 = tcp_hdr(p);
+-              if (*(u32 *)&th->source ^ *(u32 *)&th2->source) {
++              if (net_hdr_word(&th->source) ^ net_hdr_word(&th2->source)) {
+                       NAPI_GRO_CB(p)->same_flow = 0;
+                       continue;
+               }
+@@ -233,8 +233,8 @@ found:
+                 ~(TCP_FLAG_CWR | TCP_FLAG_FIN | TCP_FLAG_PSH));
+       flush |= (__force int)(th->ack_seq ^ th2->ack_seq);
+       for (i = sizeof(*th); i < thlen; i += 4)
+-              flush |= *(u32 *)((u8 *)th + i) ^
+-                       *(u32 *)((u8 *)th2 + i);
++              flush |= net_hdr_word((u8 *)th + i) ^
++                       net_hdr_word((u8 *)th2 + i);
+       /* When we receive our second frame we can made a decision on if we
+        * continue this flow as an atomic flow with a fixed ID or if we use
+--- a/net/ipv6/netfilter/ip6table_mangle.c
++++ b/net/ipv6/netfilter/ip6table_mangle.c
+@@ -58,7 +58,7 @@ ip6t_mangle_out(struct sk_buff *skb, con
+       hop_limit = ipv6_hdr(skb)->hop_limit;
+       /* flowlabel and prio (includes version, which shouldn't change either */
+-      flowlabel = *((u_int32_t *)ipv6_hdr(skb));
++      flowlabel = net_hdr_word(ipv6_hdr(skb));
+       ret = ip6t_do_table(skb, state, state->net->ipv6.ip6table_mangle);
+@@ -67,7 +67,7 @@ ip6t_mangle_out(struct sk_buff *skb, con
+            !ipv6_addr_equal(&ipv6_hdr(skb)->daddr, &daddr) ||
+            skb->mark != mark ||
+            ipv6_hdr(skb)->hop_limit != hop_limit ||
+-           flowlabel != *((u_int32_t *)ipv6_hdr(skb)))) {
++           flowlabel != net_hdr_word(ipv6_hdr(skb)))) {
+               err = ip6_route_me_harder(state->net, skb);
+               if (err < 0)
+                       ret = NF_DROP_ERR(err);