i40evf: Enable VF to request an alternate queue allocation

Currently the VF gets a default number of allocated queues from HW on
init and it could choose to enable or disable those allocated queues.
This makes it such that the VF can request more or less underlying
allocated queues from the PF.

First the VF negotiates the number of queues it wants that can be
supported by the PF and if successful asks for a reset.  During reset
the PF will reallocate the HW queues for the VF and will then remap the
new queues.

Signed-off-by: Alan Brady <alan.brady@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

1 files changed, 37 insertions, 1 deletions

diff --git a/drivers/net/ethernet/intel/i40evf/i40evf_ethtool.c b/drivers/net/ethernet/intel/i40evf/i40evf_ethtool.c
index 65874d6b3ab9..da006fa3fec1 100644
--- a/drivers/net/ethernet/intel/i40evf/i40evf_ethtool.c
+++ b/drivers/net/ethernet/intel/i40evf/i40evf_ethtool.c
@@ -669,7 +669,7 @@ static void i40evf_get_channels(struct net_device *netdev,
 	struct i40evf_adapter *adapter = netdev_priv(netdev);
 
 	/* Report maximum channels */
-	ch->max_combined = adapter->num_active_queues;
+	ch->max_combined = I40EVF_MAX_REQ_QUEUES;
 
 	ch->max_other = NONQ_VECS;
 	ch->other_count = NONQ_VECS;
@@ -678,6 +678,41 @@ static void i40evf_get_channels(struct net_device *netdev,
 }
 
 /**
+ * i40evf_set_channels: set the new channel count
+ * @netdev: network interface device structure
+ * @ch: channel information structure
+ *
+ * Negotiate a new number of channels with the PF then do a reset.  During
+ * reset we'll realloc queues and fix the RSS table.  Returns 0 on success,
+ * negative on failure.
+ **/
+static int i40evf_set_channels(struct net_device *netdev,
+			       struct ethtool_channels *ch)
+{
+	struct i40evf_adapter *adapter = netdev_priv(netdev);
+	int num_req = ch->combined_count;
+
+	if (num_req != adapter->num_active_queues &&
+	    !(adapter->vf_res->vf_cap_flags &
+	      VIRTCHNL_VF_OFFLOAD_REQ_QUEUES)) {
+		dev_info(&adapter->pdev->dev, "PF is not capable of queue negotiation.\n");
+		return -EINVAL;
+	}
+
+	/* All of these should have already been checked by ethtool before this
+	 * even gets to us, but just to be sure.
+	 */
+	if (num_req <= 0 || num_req > I40EVF_MAX_REQ_QUEUES)
+		return -EINVAL;
+
+	if (ch->rx_count || ch->tx_count || ch->other_count != NONQ_VECS)
+		return -EINVAL;
+
+	adapter->num_req_queues = num_req;
+	return i40evf_request_queues(adapter, num_req);
+}
+
+/**
  * i40evf_get_rxfh_key_size - get the RSS hash key size
  * @netdev: network interface device structure
  *
@@ -785,6 +820,7 @@ static const struct ethtool_ops i40evf_ethtool_ops = {
 	.get_rxfh		= i40evf_get_rxfh,
 	.set_rxfh		= i40evf_set_rxfh,
 	.get_channels		= i40evf_get_channels,
+	.set_channels		= i40evf_set_channels,
 	.get_rxfh_key_size	= i40evf_get_rxfh_key_size,
 	.get_link_ksettings	= i40evf_get_link_ksettings,
 };