[NET]: Make illegal_highdma more anal

Rather than having illegal_highdma as a macro when HIGHMEM is off, we
can turn it into an inline function that returns zero.  This will catch
callers that give it bad arguments.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 4 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index 4f2014994a84..08976b08df5b 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1239,7 +1239,6 @@ void netdev_rx_csum_fault(struct net_device *dev)
 EXPORT_SYMBOL(netdev_rx_csum_fault);
 #endif
 
-#ifdef CONFIG_HIGHMEM
 /* Actually, we should eliminate this check as soon as we know, that:
  * 1. IOMMU is present and allows to map all the memory.
  * 2. No high memory really exists on this machine.
@@ -1247,6 +1246,7 @@ EXPORT_SYMBOL(netdev_rx_csum_fault);
 
 static inline int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
 {
+#ifdef CONFIG_HIGHMEM
         int i;
 
         if (dev->features & NETIF_F_HIGHDMA)
@@ -1256,11 +1256,9 @@ static inline int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
                 if (PageHighMem(skb_shinfo(skb)->frags[i].page))
                         return 1;
 
+#endif
         return 0;
 }
-#else
-#define illegal_highdma(dev, skb)       (0)
-#endif
 
 struct dev_gso_cb {
         void (*destructor)(struct sk_buff *skb);