igb: Support for modifying UDP RSS flow hashing

This patch provides ability to enable or disable UDP RSS hashing. It gives
users option of generating RSS hash based on the UDP source and destination
ports numbers. Currently, UDP flow hash is always disabled in igb-driver.

Signed-off-by: Akeem G Abodunrin <akeem.g.abodunrin@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 181 insertions, 0 deletions

diff --git a/drivers/net/ethernet/intel/igb/igb_ethtool.c b/drivers/net/ethernet/intel/igb/igb_ethtool.c
index d8b1bee606c0..2b82a53f4ab3 100644
--- a/drivers/net/ethernet/intel/igb/igb_ethtool.c
+++ b/drivers/net/ethernet/intel/igb/igb_ethtool.c
@@ -2350,6 +2350,185 @@ static int igb_get_ts_info(struct net_device *dev,
         }
 }
 
+static int igb_get_rss_hash_opts(struct igb_adapter *adapter,
+                                 struct ethtool_rxnfc *cmd)
+{
+        cmd->data = 0;
+
+        /* Report default options for RSS on igb */
+        switch (cmd->flow_type) {
+        case TCP_V4_FLOW:
+                cmd->data |= RXH_L4_B_0_1 | RXH_L4_B_2_3;
+        case UDP_V4_FLOW:
+                if (adapter->flags & IGB_FLAG_RSS_FIELD_IPV4_UDP)
+                        cmd->data |= RXH_L4_B_0_1 | RXH_L4_B_2_3;
+        case SCTP_V4_FLOW:
+        case AH_ESP_V4_FLOW:
+        case AH_V4_FLOW:
+        case ESP_V4_FLOW:
+        case IPV4_FLOW:
+                cmd->data |= RXH_IP_SRC | RXH_IP_DST;
+                break;
+        case TCP_V6_FLOW:
+                cmd->data |= RXH_L4_B_0_1 | RXH_L4_B_2_3;
+        case UDP_V6_FLOW:
+                if (adapter->flags & IGB_FLAG_RSS_FIELD_IPV6_UDP)
+                        cmd->data |= RXH_L4_B_0_1 | RXH_L4_B_2_3;
+        case SCTP_V6_FLOW:
+        case AH_ESP_V6_FLOW:
+        case AH_V6_FLOW:
+        case ESP_V6_FLOW:
+        case IPV6_FLOW:
+                cmd->data |= RXH_IP_SRC | RXH_IP_DST;
+                break;
+        default:
+                return -EINVAL;
+        }
+
+        return 0;
+}
+
+static int igb_get_rxnfc(struct net_device *dev, struct ethtool_rxnfc *cmd,
+                           u32 *rule_locs)
+{
+        struct igb_adapter *adapter = netdev_priv(dev);
+        int ret = -EOPNOTSUPP;
+
+        switch (cmd->cmd) {
+        case ETHTOOL_GRXRINGS:
+                cmd->data = adapter->num_rx_queues;
+                ret = 0;
+                break;
+        case ETHTOOL_GRXFH:
+                ret = igb_get_rss_hash_opts(adapter, cmd);
+                break;
+        default:
+                break;
+        }
+
+        return ret;
+}
+
+#define UDP_RSS_FLAGS (IGB_FLAG_RSS_FIELD_IPV4_UDP | \
+                       IGB_FLAG_RSS_FIELD_IPV6_UDP)
+static int igb_set_rss_hash_opt(struct igb_adapter *adapter,
+                                struct ethtool_rxnfc *nfc)
+{
+        u32 flags = adapter->flags;
+
+        /* RSS does not support anything other than hashing
+         * to queues on src and dst IPs and ports
+         */
+        if (nfc->data & ~(RXH_IP_SRC | RXH_IP_DST |
+                          RXH_L4_B_0_1 | RXH_L4_B_2_3))
+                return -EINVAL;
+
+        switch (nfc->flow_type) {
+        case TCP_V4_FLOW:
+        case TCP_V6_FLOW:
+                if (!(nfc->data & RXH_IP_SRC) ||
+                    !(nfc->data & RXH_IP_DST) ||
+                    !(nfc->data & RXH_L4_B_0_1) ||
+                    !(nfc->data & RXH_L4_B_2_3))
+                        return -EINVAL;
+                break;
+        case UDP_V4_FLOW:
+                if (!(nfc->data & RXH_IP_SRC) ||
+                    !(nfc->data & RXH_IP_DST))
+                        return -EINVAL;
+                switch (nfc->data & (RXH_L4_B_0_1 | RXH_L4_B_2_3)) {
+                case 0:
+                        flags &= ~IGB_FLAG_RSS_FIELD_IPV4_UDP;
+                        break;
+                case (RXH_L4_B_0_1 | RXH_L4_B_2_3):
+                        flags |= IGB_FLAG_RSS_FIELD_IPV4_UDP;
+                        break;
+                default:
+                        return -EINVAL;
+                }
+                break;
+        case UDP_V6_FLOW:
+                if (!(nfc->data & RXH_IP_SRC) ||
+                    !(nfc->data & RXH_IP_DST))
+                        return -EINVAL;
+                switch (nfc->data & (RXH_L4_B_0_1 | RXH_L4_B_2_3)) {
+                case 0:
+                        flags &= ~IGB_FLAG_RSS_FIELD_IPV6_UDP;
+                        break;
+                case (RXH_L4_B_0_1 | RXH_L4_B_2_3):
+                        flags |= IGB_FLAG_RSS_FIELD_IPV6_UDP;
+                        break;
+                default:
+                        return -EINVAL;
+                }
+                break;
+        case AH_ESP_V4_FLOW:
+        case AH_V4_FLOW:
+        case ESP_V4_FLOW:
+        case SCTP_V4_FLOW:
+        case AH_ESP_V6_FLOW:
+        case AH_V6_FLOW:
+        case ESP_V6_FLOW:
+        case SCTP_V6_FLOW:
+                if (!(nfc->data & RXH_IP_SRC) ||
+                    !(nfc->data & RXH_IP_DST) ||
+                    (nfc->data & RXH_L4_B_0_1) ||
+                    (nfc->data & RXH_L4_B_2_3))
+                        return -EINVAL;
+                break;
+        default:
+                return -EINVAL;
+        }
+
+        /* if we changed something we need to update flags */
+        if (flags != adapter->flags) {
+                struct e1000_hw *hw = &adapter->hw;
+                u32 mrqc = rd32(E1000_MRQC);
+
+                if ((flags & UDP_RSS_FLAGS) &&
+                    !(adapter->flags & UDP_RSS_FLAGS))
+                        dev_err(&adapter->pdev->dev,
+                                "enabling UDP RSS: fragmented packets may arrive out of order to the stack above\n");
+
+                adapter->flags = flags;
+
+                /* Perform hash on these packet types */
+                mrqc |= E1000_MRQC_RSS_FIELD_IPV4 |
+                        E1000_MRQC_RSS_FIELD_IPV4_TCP |
+                        E1000_MRQC_RSS_FIELD_IPV6 |
+                        E1000_MRQC_RSS_FIELD_IPV6_TCP;
+
+                mrqc &= ~(E1000_MRQC_RSS_FIELD_IPV4_UDP |
+                          E1000_MRQC_RSS_FIELD_IPV6_UDP);
+
+                if (flags & IGB_FLAG_RSS_FIELD_IPV4_UDP)
+                        mrqc |= E1000_MRQC_RSS_FIELD_IPV4_UDP;
+
+                if (flags & IGB_FLAG_RSS_FIELD_IPV6_UDP)
+                        mrqc |= E1000_MRQC_RSS_FIELD_IPV6_UDP;
+
+                wr32(E1000_MRQC, mrqc);
+        }
+
+        return 0;
+}
+
+static int igb_set_rxnfc(struct net_device *dev, struct ethtool_rxnfc *cmd)
+{
+        struct igb_adapter *adapter = netdev_priv(dev);
+        int ret = -EOPNOTSUPP;
+
+        switch (cmd->cmd) {
+        case ETHTOOL_SRXFH:
+                ret = igb_set_rss_hash_opt(adapter, cmd);
+                break;
+        default:
+                break;
+        }
+
+        return ret;
+}
+
 static int igb_ethtool_begin(struct net_device *netdev)
 {
         struct igb_adapter *adapter = netdev_priv(netdev);
@@ -2390,6 +2569,8 @@ static const struct ethtool_ops igb_ethtool_ops = {
         .get_coalesce           = igb_get_coalesce,
         .set_coalesce           = igb_set_coalesce,
         .get_ts_info            = igb_get_ts_info,
+        .get_rxnfc              = igb_get_rxnfc,
+        .set_rxnfc              = igb_set_rxnfc,
         .begin                  = igb_ethtool_begin,
         .complete               = igb_ethtool_complete,
 };