[RFC PATCH v2 3/4] net: core: use a dynamic_call for dst_input

[Edward Cree]

Typically there will be a small number of callees, such as ip_local_deliver
 or ip_forward, which will cover most packets.

Signed-off-by: Edward Cree <ec...@solarflare.com>
---
 include/net/dst.h | 5 ++++-
 net/core/dst.c    | 2 ++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/include/net/dst.h b/include/net/dst.h
index 6cf0870414c7..5dd838b9a7d2 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -16,6 +16,7 @@
 #include <linux/bug.h>
 #include <linux/jiffies.h>
 #include <linux/refcount.h>
+#include <linux/dynamic_call.h>
 #include <net/neighbour.h>
 #include <asm/processor.h>
 
@@ -444,10 +445,12 @@ static inline int dst_output(struct net *net, struct sock 
*sk, struct sk_buff *s
        return skb_dst(skb)->output(net, sk, skb);
 }
 
+DEFINE_DYNAMIC_CALL_1(int, dst_input, struct sk_buff *);
+
 /* Input packet from network to transport.  */
 static inline int dst_input(struct sk_buff *skb)
 {
-       return skb_dst(skb)->input(skb);
+       return dynamic_dst_input(skb_dst(skb)->input, skb);
 }
 
 static inline struct dst_entry *dst_check(struct dst_entry *dst, u32 cookie)
diff --git a/net/core/dst.c b/net/core/dst.c
index 81ccf20e2826..a00a75bab84e 100644
--- a/net/core/dst.c
+++ b/net/core/dst.c
@@ -342,3 +342,5 @@ void metadata_dst_free_percpu(struct metadata_dst __percpu 
*md_dst)
        free_percpu(md_dst);
 }
 EXPORT_SYMBOL_GPL(metadata_dst_free_percpu);
+
+DYNAMIC_CALL_1(int, dst_input, struct sk_buff *);