tcp: minor optimization around tcp_hdr() usage in receive path

This is additional to the
commit ea1627c20c34 ("tcp: minor optimizations around tcp_hdr() usage").
At this point, skb->data is same with tcp_hdr() as tcp header has not
been pulled yet. So use the less expensive one to get the tcp header.

Remove the third parameter of tcp_rcv_established() and put it into
the function body.

Furthermore, the local variables are listed as a reverse christmas tree :)

Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 4 insertions, 4 deletions

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 1191cac72109..d5ffb573ca4d 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -5390,11 +5390,11 @@ discard:
  *      the rest is checked inline. Fast processing is turned on in
  *      tcp_data_queue when everything is OK.
  */
-void tcp_rcv_established(struct sock *sk, struct sk_buff *skb,
-                         const struct tcphdr *th)
+void tcp_rcv_established(struct sock *sk, struct sk_buff *skb)
 {
-        unsigned int len = skb->len;
+        const struct tcphdr *th = (const struct tcphdr *)skb->data;
         struct tcp_sock *tp = tcp_sk(sk);
+        unsigned int len = skb->len;
 
         /* TCP congestion window tracking */
         trace_tcp_probe(sk, skb);
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index adbdb503db0c..749b0ef9f405 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1486,7 +1486,7 @@ int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
                                 sk->sk_rx_dst = NULL;
                         }
                 }
-                tcp_rcv_established(sk, skb, tcp_hdr(skb));
+                tcp_rcv_established(sk, skb);
                 return 0;
         }