Merge branch 'inet_csums'

Tom Herbert says:

====================
net: Checksum offload changes

I am working on overhauling RX checksum offload. Goals of this effort
are:

- Specify what exactly it means when driver returns CHECKSUM_UNNECESSARY
- Preserve CHECKSUM_COMPLETE through encapsulation layers
- Don't do skb_checksum more than once per packet
- Unify GRO and non-GRO csum verification as much as possible
- Unify the checksum functions (checksum_init)
- Simply code

What is in this first patch set:

- Create a common "checksum_init" function which is called from
  TCPv{4,6} and UDPv{4,6}
- Add some for RFC6936, UDP/IPv6 zero checksums
- Add architecture support for csum_add and provide implementations
  for x86_64 and Sparc 32 and 64 bit (please test the latter)

Please review carefully and test if possible, mucking with basic
checksum functions is always a little precarious :-)
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 15 insertions, 0 deletions

diff --git a/include/net/checksum.h b/include/net/checksum.h
index a28f4e0f6251..87cb1903640d 100644
--- a/include/net/checksum.h
+++ b/include/net/checksum.h
@@ -57,12 +57,14 @@ static __inline__ __wsum csum_and_copy_to_user
 }
 #endif
 
+#ifndef HAVE_ARCH_CSUM_ADD
 static inline __wsum csum_add(__wsum csum, __wsum addend)
 {
 	u32 res = (__force u32)csum;
 	res += (__force u32)addend;
 	return (__force __wsum)(res + (res < (__force u32)addend));
 }
+#endif
 
 static inline __wsum csum_sub(__wsum csum, __wsum addend)
 {
diff --git a/include/net/ip.h b/include/net/ip.h
index 3ec2b0fb9d83..1988cefdbb70 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -342,6 +342,12 @@ static inline void ip_select_ident_more(struct sk_buff *skb, struct dst_entry *d
 		__ip_select_ident(iph, dst, more);
 }
 
+static inline __wsum inet_compute_pseudo(struct sk_buff *skb, int proto)
+{
+	return csum_tcpudp_nofold(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
+				  skb->len, proto, 0);
+}
+
 /*
  *	Map a multicast IP onto multicast MAC for type ethernet.
  */
diff --git a/include/net/ip6_checksum.h b/include/net/ip6_checksum.h
index 9e3c540c1b11..8ac5c21f8456 100644
--- a/include/net/ip6_checksum.h
+++ b/include/net/ip6_checksum.h
@@ -41,6 +41,13 @@ __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
 			__wsum csum);
 #endif
 
+static inline __wsum ip6_compute_pseudo(struct sk_buff *skb, int proto)
+{
+	return ~csum_unfold(csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
+					    &ipv6_hdr(skb)->daddr,
+					    skb->len, proto, 0));
+}
+
 static __inline__ __sum16 tcp_v6_check(int len,
 				   const struct in6_addr *saddr,
 				   const struct in6_addr *daddr,