enetc: Enable TC offloading with mqprio

Add support to configure multiple prioritized TX traffic
classes with mqprio.

Configure one BD ring per TC for the moment, one netdev
queue per TC.

Signed-off-by: Camelia Groza <[e-mail]>
Signed-off-by: Claudiu Manoil <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/ethernet/freescale/enetc/enetc.c

···
 	return 0;
 }
 
+int enetc_setup_tc(struct net_device *ndev, enum tc_setup_type type,
+		   void *type_data)
+{
+	struct enetc_ndev_priv *priv = netdev_priv(ndev);
+	struct tc_mqprio_qopt *mqprio = type_data;
+	struct enetc_bdr *tx_ring;
+	u8 num_tc;
+	int i;
+
+	if (type != TC_SETUP_QDISC_MQPRIO)
+		return -EOPNOTSUPP;
+
+	mqprio->hw = TC_MQPRIO_HW_OFFLOAD_TCS;
+	num_tc = mqprio->num_tc;
+
+	if (!num_tc) {
+		netdev_reset_tc(ndev);
+		netif_set_real_num_tx_queues(ndev, priv->num_tx_rings);
+
+		/* Reset all ring priorities to 0 */
+		for (i = 0; i < priv->num_tx_rings; i++) {
+			tx_ring = priv->tx_ring[i];
+			enetc_set_bdr_prio(&priv->si->hw, tx_ring->index, 0);
+		}
+
+		return 0;
+	}
+
+	/* Check if we have enough BD rings available to accommodate all TCs */
+	if (num_tc > priv->num_tx_rings) {
+		netdev_err(ndev, "Max %d traffic classes supported\n",
+			   priv->num_tx_rings);
+		return -EINVAL;
+	}
+
+	/* For the moment, we use only one BD ring per TC.
+	 *
+	 * Configure num_tc BD rings with increasing priorities.
+	 */
+	for (i = 0; i < num_tc; i++) {
+		tx_ring = priv->tx_ring[i];
+		enetc_set_bdr_prio(&priv->si->hw, tx_ring->index, i);
+	}
+
+	/* Reset the number of netdev queues based on the TC count */
+	netif_set_real_num_tx_queues(ndev, num_tc);
+
+	netdev_set_num_tc(ndev, num_tc);
+
+	/* Each TC is associated with one netdev queue */
+	for (i = 0; i < num_tc; i++)
+		netdev_set_tc_queue(ndev, i, 1, i);
+
+	return 0;
+}
+
 struct net_device_stats *enetc_get_stats(struct net_device *ndev)
 {
 	struct enetc_ndev_priv *priv = netdev_priv(ndev);

drivers/net/ethernet/freescale/enetc/enetc.h

···
 int enetc_set_features(struct net_device *ndev,
 		       netdev_features_t features);
 int enetc_ioctl(struct net_device *ndev, struct ifreq *rq, int cmd);
+int enetc_setup_tc(struct net_device *ndev, enum tc_setup_type type,
+		   void *type_data);
+
 /* ethtool */
 void enetc_set_ethtool_ops(struct net_device *ndev);
 

drivers/net/ethernet/freescale/enetc/enetc_hw.h

···
 #define ENETC_TBSR_BUSY	BIT(0)
 #define ENETC_TBMR_VIH	BIT(9)
 #define ENETC_TBMR_PRIO_MASK		GENMASK(2, 0)
-#define ENETC_TBMR_PRIO_SET(val)	val
+#define ENETC_TBMR_SET_PRIO(val)	((val) & ENETC_TBMR_PRIO_MASK)
 #define ENETC_TBMR_EN	BIT(31)
 #define ENETC_TBSR	0x4
 #define ENETC_TBBAR0	0x10
···
 
 	val = (val & ~ENETC_TBMR_VIH) | (en ? ENETC_TBMR_VIH : 0);
 	enetc_txbdr_wr(hw, si_idx, ENETC_TBMR, val);
+}
+
+static inline void enetc_set_bdr_prio(struct enetc_hw *hw, int bdr_idx,
+				      int prio)
+{
+	u32 val = enetc_txbdr_rd(hw, bdr_idx, ENETC_TBMR);
+
+	val &= ~ENETC_TBMR_PRIO_MASK;
+	val |= ENETC_TBMR_SET_PRIO(prio);
+	enetc_txbdr_wr(hw, bdr_idx, ENETC_TBMR, val);
 }

drivers/net/ethernet/freescale/enetc/enetc_pf.c

···
 	.ndo_set_vf_spoofchk	= enetc_pf_set_vf_spoofchk,
 	.ndo_set_features	= enetc_pf_set_features,
 	.ndo_do_ioctl		= enetc_ioctl,
+	.ndo_setup_tc		= enetc_setup_tc,
 };
 
 static void enetc_pf_netdev_setup(struct enetc_si *si, struct net_device *ndev,

drivers/net/ethernet/freescale/enetc/enetc_vf.c

···
 	.ndo_set_mac_address	= enetc_vf_set_mac_addr,
 	.ndo_set_features	= enetc_vf_set_features,
 	.ndo_do_ioctl		= enetc_ioctl,
+	.ndo_setup_tc		= enetc_setup_tc,
 };
 
 static void enetc_vf_netdev_setup(struct enetc_si *si, struct net_device *ndev,