ixgbe: Add support for displaying the number of Tx/Rx channels

This patch adds support for the ethtool get_channels operation.

Since the ixgbe driver has to support DCB as well as the other modes the
assumption I made here is that the number of channels in DCB modes refers
to the number of queues per traffic class, not the number of queues total.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Reviewed-by: John Fastabend <john.r.fastabend@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c
index db67359..cba27c6 100644 (file)
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c
@@ -2731,6 +2731,77 @@ static int ixgbe_get_ts_info(struct net_device *dev,
        return 0;
 }
 
+static unsigned int ixgbe_max_channels(struct ixgbe_adapter *adapter)
+{
+       unsigned int max_combined;
+       u8 tcs = netdev_get_num_tc(adapter->netdev);
+
+       if (!(adapter->flags & IXGBE_FLAG_MSIX_ENABLED)) {
+               /* We only support one q_vector without MSI-X */
+               max_combined = 1;
+       } else if (adapter->flags & IXGBE_FLAG_SRIOV_ENABLED) {
+               /* SR-IOV currently only allows one queue on the PF */
+               max_combined = 1;
+       } else if (tcs > 1) {
+               /* For DCB report channels per traffic class */
+               if (adapter->hw.mac.type == ixgbe_mac_82598EB) {
+                       /* 8 TC w/ 4 queues per TC */
+                       max_combined = 4;
+               } else if (tcs > 4) {
+                       /* 8 TC w/ 8 queues per TC */
+                       max_combined = 8;
+               } else {
+                       /* 4 TC w/ 16 queues per TC */
+                       max_combined = 16;
+               }
+       } else if (adapter->atr_sample_rate) {
+               /* support up to 64 queues with ATR */
+               max_combined = IXGBE_MAX_FDIR_INDICES;
+       } else {
+               /* support up to 16 queues with RSS */
+               max_combined = IXGBE_MAX_RSS_INDICES;
+       }
+
+       return max_combined;
+}
+
+static void ixgbe_get_channels(struct net_device *dev,
+                              struct ethtool_channels *ch)
+{
+       struct ixgbe_adapter *adapter = netdev_priv(dev);
+
+       /* report maximum channels */
+       ch->max_combined = ixgbe_max_channels(adapter);
+
+       /* report info for other vector */
+       if (adapter->flags & IXGBE_FLAG_MSIX_ENABLED) {
+               ch->max_other = NON_Q_VECTORS;
+               ch->other_count = NON_Q_VECTORS;
+       }
+
+       /* record RSS queues */
+       ch->combined_count = adapter->ring_feature[RING_F_RSS].indices;
+
+       /* nothing else to report if RSS is disabled */
+       if (ch->combined_count == 1)
+               return;
+
+       /* we do not support ATR queueing if SR-IOV is enabled */
+       if (adapter->flags & IXGBE_FLAG_SRIOV_ENABLED)
+               return;
+
+       /* same thing goes for being DCB enabled */
+       if (netdev_get_num_tc(dev) > 1)
+               return;
+
+       /* if ATR is disabled we can exit */
+       if (!adapter->atr_sample_rate)
+               return;
+
+       /* report flow director queues as maximum channels */
+       ch->combined_count = adapter->ring_feature[RING_F_FDIR].indices;
+}
+
 static const struct ethtool_ops ixgbe_ethtool_ops = {
        .get_settings           = ixgbe_get_settings,
        .set_settings           = ixgbe_set_settings,
@@ -2759,6 +2830,7 @@ static const struct ethtool_ops ixgbe_ethtool_ops = {
        .set_coalesce           = ixgbe_set_coalesce,
        .get_rxnfc              = ixgbe_get_rxnfc,
        .set_rxnfc              = ixgbe_set_rxnfc,
+       .get_channels           = ixgbe_get_channels,
        .get_ts_info            = ixgbe_get_ts_info,
 };