e1000e: cleanup Rx checksum offload code

1) cleanup whitespace in e1000_rx_checksum() function header comment
2) do not check hardware checksum when Rx checksum is disabled
3) reduce duplicated calls to le16_to_cpu() by just using it within
   e1000_rx_checksum() instead of in each call to the function

v2: use swab16 instead of le16_to_cpu & htons and corrected type for the
passed-in csum

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index 3911401..263bf5f 100644 (file)
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -487,22 +487,27 @@ static void e1000_receive_skb(struct e1000_adapter *adapter,
 
 /**
  * e1000_rx_checksum - Receive Checksum Offload
- * @adapter:     board private structure
- * @status_err:  receive descriptor status and error fields
- * @csum:      receive descriptor csum field
- * @sk_buff:     socket buffer with received data
+ * @adapter: board private structure
+ * @status_err: receive descriptor status and error fields
+ * @csum: receive descriptor csum field
+ * @sk_buff: socket buffer with received data
  **/
 static void e1000_rx_checksum(struct e1000_adapter *adapter, u32 status_err,
-                             u32 csum, struct sk_buff *skb)
+                             __le16 csum, struct sk_buff *skb)
 {
        u16 status = (u16)status_err;
        u8 errors = (u8)(status_err >> 24);
 
        skb_checksum_none_assert(skb);
 
+       /* Rx checksum disabled */
+       if (!(adapter->netdev->features & NETIF_F_RXCSUM))
+               return;
+
        /* Ignore Checksum bit is set */
        if (status & E1000_RXD_STAT_IXSM)
                return;
+
        /* TCP/UDP checksum error bit is set */
        if (errors & E1000_RXD_ERR_TCPE) {
                /* let the stack verify checksum errors */
@@ -524,7 +529,7 @@ static void e1000_rx_checksum(struct e1000_adapter *adapter, u32 status_err,
                 * Hardware complements the payload checksum, so we undo it
                 * and then put the value in host order for further stack use.
                 */
-               __sum16 sum = (__force __sum16)htons(csum);
+               __sum16 sum = (__force __sum16)swab16((__force u16)csum);
                skb->csum = csum_unfold(~sum);
                skb->ip_summed = CHECKSUM_COMPLETE;
        }
@@ -957,8 +962,7 @@ static bool e1000_clean_rx_irq(struct e1000_adapter *adapter,
 
                /* Receive Checksum Offload */
                e1000_rx_checksum(adapter, staterr,
-                                 le16_to_cpu(rx_desc->wb.lower.hi_dword.
-                                             csum_ip.csum), skb);
+                                 rx_desc->wb.lower.hi_dword.csum_ip.csum, skb);
 
                e1000_receive_skb(adapter, netdev, skb, staterr,
                                  rx_desc->wb.upper.vlan);
@@ -1318,8 +1322,8 @@ copydone:
                total_rx_bytes += skb->len;
                total_rx_packets++;
 
-               e1000_rx_checksum(adapter, staterr, le16_to_cpu(
-                       rx_desc->wb.lower.hi_dword.csum_ip.csum), skb);
+               e1000_rx_checksum(adapter, staterr,
+                                 rx_desc->wb.lower.hi_dword.csum_ip.csum, skb);
 
                if (rx_desc->wb.upper.header_status &
                           cpu_to_le16(E1000_RXDPS_HDRSTAT_HDRSP))
@@ -1491,8 +1495,7 @@ static bool e1000_clean_jumbo_rx_irq(struct e1000_adapter *adapter,
 
                /* Receive Checksum Offload XXX recompute due to CRC strip? */
                e1000_rx_checksum(adapter, staterr,
-                                 le16_to_cpu(rx_desc->wb.lower.hi_dword.
-                                             csum_ip.csum), skb);
+                                 rx_desc->wb.lower.hi_dword.csum_ip.csum, skb);
 
                /* probably a little skewed due to removing CRC */
                total_rx_bytes += skb->len;