net: introduce __netdev_alloc_skb_ip_align

RX rings should use GFP_KERNEL allocations if possible, add
__netdev_alloc_skb_ip_align() helper to ease this.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/linux/skbuff.h

@@ -1579,16 +1579,22 @@ static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev,
 	return __netdev_alloc_skb(dev, length, GFP_ATOMIC);
 }
 
-static inline struct sk_buff *netdev_alloc_skb_ip_align(struct net_device *dev,
-		unsigned int length)
+static inline struct sk_buff *__netdev_alloc_skb_ip_align(struct net_device *dev,
+		unsigned int length, gfp_t gfp)
 {
-	struct sk_buff *skb = netdev_alloc_skb(dev, length + NET_IP_ALIGN);
+	struct sk_buff *skb = __netdev_alloc_skb(dev, length + NET_IP_ALIGN, gfp);
 
 	if (NET_IP_ALIGN && skb)
 		skb_reserve(skb, NET_IP_ALIGN);
 	return skb;
 }
 
+static inline struct sk_buff *netdev_alloc_skb_ip_align(struct net_device *dev,
+		unsigned int length)
+{
+	return __netdev_alloc_skb_ip_align(dev, length, GFP_ATOMIC);
+}
+
 /**
  *	__netdev_alloc_page - allocate a page for ps-rx on a specific device
  *	@dev: network device to receive on