net: mvneta: Allow having more than one queue per TC

The current mqprio implementation assumed that we are only using one
queue per TC. Use the offset and count parameters to allow using
multiple queues per TC. In that case, the controller will use a standard
round-robin algorithm to pick queues assigned to the same TC, with the
same priority.

This only applies to VLAN priorities in ingress traffic, each TC
corresponding to a vlan priority.
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/marvell/mvneta.c

@@ -493,7 +493,6 @@ struct mvneta_port {
 	u8 mcast_count[256];
 	u16 tx_ring_size;
 	u16 rx_ring_size;
-	u8 prio_tc_map[8];
 
 	phy_interface_t phy_interface;
 	struct device_node *dn;
@@ -4897,13 +4896,12 @@ static void mvneta_clear_rx_prio_map(struct mvneta_port *pp)
 	mvreg_write(pp, MVNETA_VLAN_PRIO_TO_RXQ, 0);
 }
 
-static void mvneta_setup_rx_prio_map(struct mvneta_port *pp)
+static void mvneta_map_vlan_prio_to_rxq(struct mvneta_port *pp, u8 pri, u8 rxq)
 {
-	u32 val = 0;
-	int i;
+	u32 val = mvreg_read(pp, MVNETA_VLAN_PRIO_TO_RXQ);
 
-	for (i = 0; i < rxq_number; i++)
-		val |= MVNETA_VLAN_PRIO_RXQ_MAP(i, pp->prio_tc_map[i]);
+	val &= ~MVNETA_VLAN_PRIO_RXQ_MAP(pri, 0x7);
+	val |= MVNETA_VLAN_PRIO_RXQ_MAP(pri, rxq);
 
 	mvreg_write(pp, MVNETA_VLAN_PRIO_TO_RXQ, val);
 }
@@ -4912,8 +4910,8 @@ static int mvneta_setup_mqprio(struct net_device *dev,
 			       struct tc_mqprio_qopt_offload *mqprio)
 {
 	struct mvneta_port *pp = netdev_priv(dev);
+	int rxq, tc;
 	u8 num_tc;
-	int i;
 
 	if (mqprio->qopt.hw != TC_MQPRIO_HW_OFFLOAD_TCS)
 		return 0;
@@ -4923,21 +4921,28 @@ static int mvneta_setup_mqprio(struct net_device *dev,
 	if (num_tc > rxq_number)
 		return -EINVAL;
 
+	mvneta_clear_rx_prio_map(pp);
+
 	if (!num_tc) {
-		mvneta_clear_rx_prio_map(pp);
 		netdev_reset_tc(dev);
 		return 0;
 	}
 
-	memcpy(pp->prio_tc_map, mqprio->qopt.prio_tc_map,
-	       sizeof(pp->prio_tc_map));
+	netdev_set_num_tc(dev, mqprio->qopt.num_tc);
+
+	for (tc = 0; tc < mqprio->qopt.num_tc; tc++) {
+		netdev_set_tc_queue(dev, tc, mqprio->qopt.count[tc],
+				    mqprio->qopt.offset[tc]);
 
-	mvneta_setup_rx_prio_map(pp);
+		for (rxq = mqprio->qopt.offset[tc];
+		     rxq < mqprio->qopt.count[tc] + mqprio->qopt.offset[tc];
+		     rxq++) {
+			if (rxq >= rxq_number)
+				return -EINVAL;
 
-	netdev_set_num_tc(dev, mqprio->qopt.num_tc);
-	for (i = 0; i < mqprio->qopt.num_tc; i++)
-		netdev_set_tc_queue(dev, i, mqprio->qopt.count[i],
-				    mqprio->qopt.offset[i]);
+			mvneta_map_vlan_prio_to_rxq(pp, tc, rxq);
+		}
+	}
 
 	return 0;
 }