ftgmac100: Cleanup rx checksum handling

Read the descriptor field only once and check for IP header
checksum errors as well

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/faraday/ftgmac100.c b/drivers/net/ethernet/faraday/ftgmac100.c
index 876f54aa42f769f1adc6868f3825cb4d355c1fca..6277f6e70f6b7510680df9cd07fc2a02db1aa96f 100644 (file)
--- a/drivers/net/ethernet/faraday/ftgmac100.c
+++ b/drivers/net/ethernet/faraday/ftgmac100.c
@@ -352,31 +352,11 @@ static dma_addr_t ftgmac100_rxdes_get_dma_addr(struct ftgmac100_rxdes *rxdes)
        return le32_to_cpu(rxdes->rxdes3);
 }
 
-static bool ftgmac100_rxdes_is_tcp(struct ftgmac100_rxdes *rxdes)
+static inline bool ftgmac100_rxdes_csum_err(struct ftgmac100_rxdes *rxdes)
 {
-       return (rxdes->rxdes1 & cpu_to_le32(FTGMAC100_RXDES1_PROT_MASK)) ==
-              cpu_to_le32(FTGMAC100_RXDES1_PROT_TCPIP);
-}
-
-static bool ftgmac100_rxdes_is_udp(struct ftgmac100_rxdes *rxdes)
-{
-       return (rxdes->rxdes1 & cpu_to_le32(FTGMAC100_RXDES1_PROT_MASK)) ==
-              cpu_to_le32(FTGMAC100_RXDES1_PROT_UDPIP);
-}
-
-static bool ftgmac100_rxdes_tcpcs_err(struct ftgmac100_rxdes *rxdes)
-{
-       return rxdes->rxdes1 & cpu_to_le32(FTGMAC100_RXDES1_TCP_CHKSUM_ERR);
-}
-
-static bool ftgmac100_rxdes_udpcs_err(struct ftgmac100_rxdes *rxdes)
-{
-       return rxdes->rxdes1 & cpu_to_le32(FTGMAC100_RXDES1_UDP_CHKSUM_ERR);
-}
-
-static bool ftgmac100_rxdes_ipcs_err(struct ftgmac100_rxdes *rxdes)
-{
-       return rxdes->rxdes1 & cpu_to_le32(FTGMAC100_RXDES1_IP_CHKSUM_ERR);
+       return !!(rxdes->rxdes1 & cpu_to_le32(FTGMAC100_RXDES1_TCP_CHKSUM_ERR |
+                                             FTGMAC100_RXDES1_UDP_CHKSUM_ERR |
+                                             FTGMAC100_RXDES1_IP_CHKSUM_ERR));
 }
 
 static inline struct page **ftgmac100_rxdes_page_slot(struct ftgmac100 *priv,
@@ -486,11 +466,6 @@ static bool ftgmac100_rx_packet_error(struct ftgmac100 *priv,
 
                netdev->stats.rx_crc_errors++;
                error = true;
-       } else if (unlikely(ftgmac100_rxdes_ipcs_err(rxdes))) {
-               if (net_ratelimit())
-                       netdev_info(netdev, "rx IP checksum err\n");
-
-               error = true;
        }
 
        if (unlikely(ftgmac100_rxdes_frame_too_long(rxdes))) {
@@ -582,14 +557,23 @@ static bool ftgmac100_rx_packet(struct ftgmac100 *priv, int *processed)
        if (unlikely(ftgmac100_rxdes_multicast(rxdes)))
                netdev->stats.multicast++;
 
-       /*
-        * It seems that HW does checksum incorrectly with fragmented packets,
-        * so we are conservative here - if HW checksum error, let software do
-        * the checksum again.
+       /* If the HW found checksum errors, bounce it to software.
+        *
+        * If we didn't, we need to see if the packet was recognized
+        * by HW as one of the supported checksummed protocols before
+        * we accept the HW test results.
         */
-       if ((ftgmac100_rxdes_is_tcp(rxdes) && !ftgmac100_rxdes_tcpcs_err(rxdes)) ||
-           (ftgmac100_rxdes_is_udp(rxdes) && !ftgmac100_rxdes_udpcs_err(rxdes)))
-               skb->ip_summed = CHECKSUM_UNNECESSARY;
+       if (netdev->features & NETIF_F_RXCSUM) {
+               __le32 csum_vlan = rxdes->rxdes1;
+               __le32 err_bits = cpu_to_le32(FTGMAC100_RXDES1_TCP_CHKSUM_ERR |
+                                             FTGMAC100_RXDES1_UDP_CHKSUM_ERR |
+                                             FTGMAC100_RXDES1_IP_CHKSUM_ERR);
+               if ((csum_vlan & err_bits) ||
+                   !(csum_vlan & cpu_to_le32(FTGMAC100_RXDES1_PROT_MASK)))
+                       skb->ip_summed = CHECKSUM_NONE;
+               else
+                       skb->ip_summed = CHECKSUM_UNNECESSARY;
+       }
 
        map = ftgmac100_rxdes_get_dma_addr(rxdes);
 
@@ -621,7 +605,10 @@ static bool ftgmac100_rx_packet(struct ftgmac100 *priv, int *processed)
        netdev->stats.rx_bytes += skb->len;
 
        /* push packet to protocol stack */
-       napi_gro_receive(&priv->napi, skb);
+       if (skb->ip_summed == CHECKSUM_NONE)
+               netif_receive_skb(skb);
+       else
+               napi_gro_receive(&priv->napi, skb);
 
        (*processed)++;
        return true;
@@ -1575,7 +1562,7 @@ static int ftgmac100_probe(struct platform_device *pdev)
         * when NCSI is enabled on the interface. It doesn't work
         * in that case.
         */
-       netdev->features = NETIF_F_IP_CSUM | NETIF_F_GRO;
+       netdev->features = NETIF_F_RXCSUM | NETIF_F_IP_CSUM | NETIF_F_GRO;
        if (priv->use_ncsi &&
            of_get_property(pdev->dev.of_node, "no-hw-checksum", NULL))
                netdev->features &= ~NETIF_F_IP_CSUM;