net: dev: move inline skb_needs_linearize helper to header

As we need it elsewhere, move the inline helper function of
skb_needs_linearize() over to skbuff.h include file. While
at it, also convert the return to 'bool' instead of 'int'
and add a proper kernel doc.

Signed-off-by: Daniel Borkmann <[email protected]>
Signed-off-by: Jesper Dangaard Brouer <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

Author: Daniel Borkmann

include/linux/skbuff.h

@@ -2392,6 +2392,24 @@ static inline void *skb_header_pointer(const struct sk_buff *skb, int offset,
 	return buffer;
 }
 
+/**
+ *	skb_needs_linearize - check if we need to linearize a given skb
+ *			      depending on the given device features.
+ *	@skb: socket buffer to check
+ *	@features: net device features
+ *
+ *	Returns true if either:
+ *	1. skb has frag_list and the device doesn't support FRAGLIST, or
+ *	2. skb is fragmented and the device does not support SG.
+ */
+static inline bool skb_needs_linearize(struct sk_buff *skb,
+				       netdev_features_t features)
+{
+	return skb_is_nonlinear(skb) &&
+	       ((skb_has_frag_list(skb) && !(features & NETIF_F_FRAGLIST)) ||
+		(skb_shinfo(skb)->nr_frags && !(features & NETIF_F_SG)));
+}
+
 static inline void skb_copy_from_linear_data(const struct sk_buff *skb,
 					     void *to,
 					     const unsigned int len)

net/core/dev.c

@@ -2535,21 +2535,6 @@ netdev_features_t netif_skb_features(struct sk_buff *skb)
 }
 EXPORT_SYMBOL(netif_skb_features);
 
-/*
- * Returns true if either:
- *	1. skb has frag_list and the device doesn't support FRAGLIST, or
- *	2. skb is fragmented and the device does not support SG.
- */
-static inline int skb_needs_linearize(struct sk_buff *skb,
-				      netdev_features_t features)
-{
-	return skb_is_nonlinear(skb) &&
-			((skb_has_frag_list(skb) &&
-				!(features & NETIF_F_FRAGLIST)) ||
-			(skb_shinfo(skb)->nr_frags &&
-				!(features & NETIF_F_SG)));
-}
-
 int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,
 			struct netdev_queue *txq, void *accel_priv)
 {