e1000e: Support RXFCS feature flag.

This enables enabling/disabling reception of the Ethernet
FCS.  This can be useful when sniffing packets.

For e1000e, enabling RXFCS can change the default
behaviour for how the NIC handles CRC.  Disabling RXFCS
will take the NIC back to defaults, which can be configured
as part of the module options.

Signed-off-by: Ben Greear <greearb@candelatech.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/e1000.h b/drivers/net/ethernet/intel/e1000e/e1000.h
index 45e5ae8a9fb7615ab7405680217d646be4d5283e..04a21fcb827e6fd03f4f3851a5799c7041c207fe 100644 (file)
--- a/drivers/net/ethernet/intel/e1000e/e1000.h
+++ b/drivers/net/ethernet/intel/e1000e/e1000.h
@@ -461,6 +461,7 @@ struct e1000_info {
 #define FLAG2_CHECK_PHY_HANG              (1 << 9)
 #define FLAG2_NO_DISABLE_RX               (1 << 10)
 #define FLAG2_PCIM2PCI_ARBITER_WA         (1 << 11)
+#define FLAG2_DFLT_CRC_STRIPPING          (1 << 12)
 
 #define E1000_RX_DESC_PS(R, i)     \
        (&(((union e1000_rx_desc_packet_split *)((R).desc))[i]))

diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index c079b9b0810d2dc792b77e559d9cb0ebb5e92ebd..30c8c15d0396ad51d6bea81eb54f1882daec3b0f 100644 (file)
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -933,8 +933,16 @@ static bool e1000_clean_rx_irq(struct e1000_ring *rx_ring, int *work_done,
                }
 
                /* adjust length to remove Ethernet CRC */
-               if (!(adapter->flags2 & FLAG2_CRC_STRIPPING))
-                       length -= 4;
+               if (!(adapter->flags2 & FLAG2_CRC_STRIPPING)) {
+                       /* If configured to store CRC, don't subtract FCS,
+                        * but keep the FCS bytes out of the total_rx_bytes
+                        * counter
+                        */
+                       if (netdev->features & NETIF_F_RXFCS)
+                               total_rx_bytes -= 4;
+                       else
+                               length -= 4;
+               }
 
                total_rx_bytes += length;
                total_rx_packets++;
@@ -1301,8 +1309,10 @@ static bool e1000_clean_rx_irq_ps(struct e1000_ring *rx_ring, int *work_done,
                                                           DMA_FROM_DEVICE);
 
                                /* remove the CRC */
-                               if (!(adapter->flags2 & FLAG2_CRC_STRIPPING))
-                                       l1 -= 4;
+                               if (!(adapter->flags2 & FLAG2_CRC_STRIPPING)) {
+                                       if (!(netdev->features & NETIF_F_RXFCS))
+                                               l1 -= 4;
+                               }
 
                                skb_put(skb, l1);
                                goto copydone;
@@ -1328,8 +1338,10 @@ static bool e1000_clean_rx_irq_ps(struct e1000_ring *rx_ring, int *work_done,
                /* strip the ethernet crc, problem is we're using pages now so
                 * this whole operation can get a little cpu intensive
                 */
-               if (!(adapter->flags2 & FLAG2_CRC_STRIPPING))
-                       pskb_trim(skb, skb->len - 4);
+               if (!(adapter->flags2 & FLAG2_CRC_STRIPPING)) {
+                       if (!(netdev->features & NETIF_F_RXFCS))
+                               pskb_trim(skb, skb->len - 4);
+               }
 
 copydone:
                total_rx_bytes += skb->len;
@@ -5982,7 +5994,7 @@ static int e1000_set_features(struct net_device *netdev,
                adapter->flags |= FLAG_TSO_FORCE;
 
        if (!(changed & (NETIF_F_HW_VLAN_RX | NETIF_F_HW_VLAN_TX |
-                        NETIF_F_RXCSUM | NETIF_F_RXHASH)))
+                        NETIF_F_RXCSUM | NETIF_F_RXHASH | NETIF_F_RXFCS)))
                return 0;
 
        /*
@@ -5996,6 +6008,20 @@ static int e1000_set_features(struct net_device *netdev,
                return -EINVAL;
        }
 
+       if (changed & NETIF_F_RXFCS) {
+               if (features & NETIF_F_RXFCS) {
+                       adapter->flags2 &= ~FLAG2_CRC_STRIPPING;
+               } else {
+                       /* We need to take it back to defaults, which might mean
+                        * stripping is still disabled at the adapter level.
+                        */
+                       if (adapter->flags2 & FLAG2_DFLT_CRC_STRIPPING)
+                               adapter->flags2 |= FLAG2_CRC_STRIPPING;
+                       else
+                               adapter->flags2 &= ~FLAG2_CRC_STRIPPING;
+               }
+       }
+
        netdev->features = features;
 
        if (netif_running(netdev))
@@ -6194,6 +6220,7 @@ static int __devinit e1000_probe(struct pci_dev *pdev,
 
        /* Set user-changeable features (subset of all device features) */
        netdev->hw_features = netdev->features;
+       netdev->hw_features |= NETIF_F_RXFCS;
 
        if (adapter->flags & FLAG_HAS_HW_VLAN_FILTER)
                netdev->features |= NETIF_F_HW_VLAN_FILTER;

diff --git a/drivers/net/ethernet/intel/e1000e/param.c b/drivers/net/ethernet/intel/e1000e/param.c
index 9c6a56d804a4c8290aa044f3878c1a640850455f..ff796e42c3ebbf1b146a28b677e7bb885e1f6bf6 100644 (file)
--- a/drivers/net/ethernet/intel/e1000e/param.c
+++ b/drivers/net/ethernet/intel/e1000e/param.c
@@ -463,10 +463,13 @@ void __devinit e1000e_check_options(struct e1000_adapter *adapter)
                if (num_CrcStripping > bd) {
                        unsigned int crc_stripping = CrcStripping[bd];
                        e1000_validate_option(&crc_stripping, &opt, adapter);
-                       if (crc_stripping == OPTION_ENABLED)
+                       if (crc_stripping == OPTION_ENABLED) {
                                adapter->flags2 |= FLAG2_CRC_STRIPPING;
+                               adapter->flags2 |= FLAG2_DFLT_CRC_STRIPPING;
+                       }
                } else {
                        adapter->flags2 |= FLAG2_CRC_STRIPPING;
+                       adapter->flags2 |= FLAG2_DFLT_CRC_STRIPPING;
                }
        }
        { /* Kumeran Lock Loss Workaround */