net: ravb: Simplify types in RX csum validation

The hardware checksum value is used as a 16-bit flag, it is zero when
the checksum has been validated and non-zero otherwise. Therefore we
don't need to treat this as an actual __wsum type or call csum_unfold(),
we can just use a u16 pointer.

Signed-off-by: Paul Barker <paul.barker.ct@bp.renesas.com>
Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>

diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index 2f584c353c7819ef5023c89c77fa6927fd0b7986..ca8f785b96b4cb8f4ef73ddce5039c567295e731 100644 (file)
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -749,11 +749,11 @@ static void ravb_get_tx_tstamp(struct net_device *ndev)
 static void ravb_rx_csum_gbeth(struct sk_buff *skb)
 {
        struct skb_shared_info *shinfo = skb_shinfo(skb);
-       __wsum csum_proto;
-       u8 *hw_csum;
+       size_t csum_len;
+       u16 *hw_csum;
 
-       /* The hardware checksum status is contained in sizeof(__sum16) * 2 = 4
-        * bytes appended to packet data.
+       /* The hardware checksum status is contained in 4 bytes appended to
+        * packet data.
         *
         * For ipv4, the first 2 bytes are the ip header checksum status. We can
         * ignore this as it will always be re-checked in inet_gro_receive().
@@ -761,24 +761,22 @@ static void ravb_rx_csum_gbeth(struct sk_buff *skb)
         * The last 2 bytes are the protocol checksum status which will be zero
         * if the checksum has been validated.
         */
-       if (unlikely(skb->len < sizeof(__sum16) * 2))
+       csum_len = sizeof(*hw_csum) * 2;
+       if (unlikely(skb->len < csum_len))
                return;
 
        if (skb_is_nonlinear(skb)) {
                skb_frag_t *last_frag = &shinfo->frags[shinfo->nr_frags - 1];
 
-               hw_csum = skb_frag_address(last_frag) +
-                         skb_frag_size(last_frag);
-               skb_frag_size_sub(last_frag, 2 * sizeof(__sum16));
+               hw_csum = (u16 *)(skb_frag_address(last_frag) +
+                                 skb_frag_size(last_frag));
+               skb_frag_size_sub(last_frag, csum_len);
        } else {
-               hw_csum = skb_tail_pointer(skb);
-               skb_trim(skb, skb->len - 2 * sizeof(__sum16));
+               hw_csum = (u16 *)skb_tail_pointer(skb);
+               skb_trim(skb, skb->len - csum_len);
        }
 
-       hw_csum -= sizeof(__sum16);
-       csum_proto = csum_unfold((__force __sum16)get_unaligned_le16(hw_csum));
-
-       if (!csum_proto)
+       if (!get_unaligned(--hw_csum))
                skb->ip_summed = CHECKSUM_UNNECESSARY;
 }