Merge tag 'platform-drivers-x86-v4.13-1' of git://git.infradead.org/linux-platform...

[karo-tx-linux.git] / include / net / udp.h

diff --git a/include/net/udp.h b/include/net/udp.h
index 1468dbd0f09ad5eeb559fffb545bda6f051f7301..972ce4baab6b2a4b0539624d1a671c632d77514c 100644 (file)
--- a/include/net/udp.h
+++ b/include/net/udp.h
@@ -302,6 +302,67 @@ struct sock *__udp6_lib_lookup(struct net *net,
 struct sock *udp6_lib_lookup_skb(struct sk_buff *skb,
                                 __be16 sport, __be16 dport);
 
+/* UDP uses skb->dev_scratch to cache as much information as possible and avoid
+ * possibly multiple cache miss on dequeue()
+ */
+#if BITS_PER_LONG == 64
+
+/* truesize, len and the bit needed to compute skb_csum_unnecessary will be on
+ * cold cache lines at recvmsg time.
+ * skb->len can be stored on 16 bits since the udp header has been already
+ * validated and pulled.
+ */
+struct udp_dev_scratch {
+       u32 truesize;
+       u16 len;
+       bool is_linear;
+       bool csum_unnecessary;
+};
+
+static inline unsigned int udp_skb_len(struct sk_buff *skb)
+{
+       return ((struct udp_dev_scratch *)&skb->dev_scratch)->len;
+}
+
+static inline bool udp_skb_csum_unnecessary(struct sk_buff *skb)
+{
+       return ((struct udp_dev_scratch *)&skb->dev_scratch)->csum_unnecessary;
+}
+
+static inline bool udp_skb_is_linear(struct sk_buff *skb)
+{
+       return ((struct udp_dev_scratch *)&skb->dev_scratch)->is_linear;
+}
+
+#else
+static inline unsigned int udp_skb_len(struct sk_buff *skb)
+{
+       return skb->len;
+}
+
+static inline bool udp_skb_csum_unnecessary(struct sk_buff *skb)
+{
+       return skb_csum_unnecessary(skb);
+}
+
+static inline bool udp_skb_is_linear(struct sk_buff *skb)
+{
+       return !skb_is_nonlinear(skb);
+}
+#endif
+
+static inline int copy_linear_skb(struct sk_buff *skb, int len, int off,
+                                 struct iov_iter *to)
+{
+       int n, copy = len - off;
+
+       n = copy_to_iter(skb->data + off, copy, to);
+       if (n == copy)
+               return 0;
+
+       return -EFAULT;
+}
+
 /*
  *     SNMP statistics for UDP and UDP-Lite
  */