[PATCH net-next v1 7/9] igc: Add support for Frame Preemption offload

[Vinicius Costa Gomes <vinicius.gomes@intel.com>]

After the set of queues that are marked as preemptible are exposed to
the driver we can configure the hardware to enable the frame
preemption functionality.

Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
---
 drivers/net/ethernet/intel/igc/igc_main.c | 32 +++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index 3af54fd9cc0d..763f39082f91 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -4817,6 +4817,23 @@ static int igc_save_qbv_schedule(struct igc_adapter *adapter,
 	return 0;
 }
 
+static int igc_save_frame_preemption(struct igc_adapter *adapter,
+				     struct tc_preempt_qopt_offload *qopt)
+{
+	u32 preempt;
+	int i;
+
+	preempt = qopt->preemptible_queues;
+
+	for (i = 0; i < adapter->num_tx_queues; i++) {
+		struct igc_ring *ring = adapter->tx_ring[i];
+
+		ring->preemptible = preempt & BIT(i);
+	}
+
+	return 0;
+}
+
 static int igc_tsn_enable_qbv_scheduling(struct igc_adapter *adapter,
 					 struct tc_taprio_qopt_offload *qopt)
 {
@@ -4833,6 +4850,18 @@ static int igc_tsn_enable_qbv_scheduling(struct igc_adapter *adapter,
 	return igc_tsn_offload_apply(adapter);
 }
 
+static int igc_tsn_enable_frame_preemption(struct igc_adapter *adapter,
+					   struct tc_preempt_qopt_offload *qopt)
+{
+	int err;
+
+	err = igc_save_frame_preemption(adapter, qopt);
+	if (err)
+		return err;
+
+	return igc_tsn_offload_apply(adapter);
+}
+
 static int igc_setup_tc(struct net_device *dev, enum tc_setup_type type,
 			void *type_data)
 {
@@ -4845,6 +4874,9 @@ static int igc_setup_tc(struct net_device *dev, enum tc_setup_type type,
 	case TC_SETUP_QDISC_ETF:
 		return igc_tsn_enable_launchtime(adapter, type_data);
 
+	case TC_SETUP_PREEMPT:
+		return igc_tsn_enable_frame_preemption(adapter, type_data);
+
 	default:
 		return -EOPNOTSUPP;
 	}
-- 
2.29.2