igb: Add support for ethtool private flag to allow use of legacy Rx

Since there are potential drawbacks to the new Rx allocation approach I
thought it best to add a "chicken bit" so that we can turn the feature off
if in the event that a problem is found.

It also provides a means of validating the legacy Rx path in the event that
we are forced to fall back.  At some point in the future when we are
convinced we don't need it anymore we might be able to drop the legacy-rx
flag.

Signed-off-by: Alexander Duyck <alexander.h.duyck@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/igb/igb.h b/drivers/net/ethernet/intel/igb/igb.h
index 6a88a08c021c79d37c5390b763ab8a4546f65987..bffdfe65a0b6ad04bfd13508d1fd3099388fa2e1 100644 (file)
--- a/drivers/net/ethernet/intel/igb/igb.h
+++ b/drivers/net/ethernet/intel/igb/igb.h
@@ -557,6 +557,7 @@ struct igb_adapter {
 #define IGB_FLAG_HAS_MSIX              BIT(13)
 #define IGB_FLAG_EEE                   BIT(14)
 #define IGB_FLAG_VLAN_PROMISC          BIT(15)
+#define IGB_FLAG_RX_LEGACY             BIT(16)
 
 /* Media Auto Sense */
 #define IGB_MAS_ENABLE_0               0X0001

diff --git a/drivers/net/ethernet/intel/igb/igb_ethtool.c b/drivers/net/ethernet/intel/igb/igb_ethtool.c
index d5966feb7b96c00ecb586ddbe017c2940df08772..797b9daba224aa95e68816a677409e31a4d1a349 100644 (file)
--- a/drivers/net/ethernet/intel/igb/igb_ethtool.c
+++ b/drivers/net/ethernet/intel/igb/igb_ethtool.c
@@ -144,6 +144,13 @@ static const char igb_gstrings_test[][ETH_GSTRING_LEN] = {
 };
 #define IGB_TEST_LEN (sizeof(igb_gstrings_test) / ETH_GSTRING_LEN)
 
+static const char igb_priv_flags_strings[][ETH_GSTRING_LEN] = {
+#define IGB_PRIV_FLAGS_LEGACY_RX       BIT(0)
+       "legacy-rx",
+};
+
+#define IGB_PRIV_FLAGS_STR_LEN ARRAY_SIZE(igb_priv_flags_strings)
+
 static int igb_get_settings(struct net_device *netdev, struct ethtool_cmd *ecmd)
 {
        struct igb_adapter *adapter = netdev_priv(netdev);
@@ -852,6 +859,8 @@ static void igb_get_drvinfo(struct net_device *netdev,
                sizeof(drvinfo->fw_version));
        strlcpy(drvinfo->bus_info, pci_name(adapter->pdev),
                sizeof(drvinfo->bus_info));
+
+       drvinfo->n_priv_flags = IGB_PRIV_FLAGS_STR_LEN;
 }
 
 static void igb_get_ringparam(struct net_device *netdev,
@@ -2280,6 +2289,8 @@ static int igb_get_sset_count(struct net_device *netdev, int sset)
                return IGB_STATS_LEN;
        case ETH_SS_TEST:
                return IGB_TEST_LEN;
+       case ETH_SS_PRIV_FLAGS:
+               return IGB_PRIV_FLAGS_STR_LEN;
        default:
                return -ENOTSUPP;
        }
@@ -2385,6 +2396,10 @@ static void igb_get_strings(struct net_device *netdev, u32 stringset, u8 *data)
                }
                /* BUG_ON(p - data != IGB_STATS_LEN * ETH_GSTRING_LEN); */
                break;
+       case ETH_SS_PRIV_FLAGS:
+               memcpy(data, igb_priv_flags_strings,
+                      IGB_PRIV_FLAGS_STR_LEN * ETH_GSTRING_LEN);
+               break;
        }
 }
 
@@ -3397,6 +3412,37 @@ static int igb_set_channels(struct net_device *netdev,
        return 0;
 }
 
+static u32 igb_get_priv_flags(struct net_device *netdev)
+{
+       struct igb_adapter *adapter = netdev_priv(netdev);
+       u32 priv_flags = 0;
+
+       if (adapter->flags & IGB_FLAG_RX_LEGACY)
+               priv_flags |= IGB_PRIV_FLAGS_LEGACY_RX;
+
+       return priv_flags;
+}
+
+static int igb_set_priv_flags(struct net_device *netdev, u32 priv_flags)
+{
+       struct igb_adapter *adapter = netdev_priv(netdev);
+       unsigned int flags = adapter->flags;
+
+       flags &= ~IGB_FLAG_RX_LEGACY;
+       if (priv_flags & IGB_PRIV_FLAGS_LEGACY_RX)
+               flags |= IGB_FLAG_RX_LEGACY;
+
+       if (flags != adapter->flags) {
+               adapter->flags = flags;
+
+               /* reset interface to repopulate queues */
+               if (netif_running(netdev))
+                       igb_reinit_locked(adapter);
+       }
+
+       return 0;
+}
+
 static const struct ethtool_ops igb_ethtool_ops = {
        .get_settings           = igb_get_settings,
        .set_settings           = igb_set_settings,
@@ -3435,6 +3481,8 @@ static const struct ethtool_ops igb_ethtool_ops = {
        .set_rxfh               = igb_set_rxfh,
        .get_channels           = igb_get_channels,
        .set_channels           = igb_set_channels,
+       .get_priv_flags         = igb_get_priv_flags,
+       .set_priv_flags         = igb_set_priv_flags,
        .begin                  = igb_ethtool_begin,
        .complete               = igb_ethtool_complete,
 };