dpaa2-eth: add support for TBF offload

React to TC_SETUP_QDISC_TBF and configure the egress shaper as
appropriate with the maximum rate and burst size requested by the user.
TBF can only be offloaded on DPAA2 when it's the root qdisc, ie it's a
per port shaper.
Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c

@@ -15,6 +15,7 @@
 #include <linux/fsl/mc.h>
 #include <linux/bpf.h>
 #include <linux/bpf_trace.h>
+#include <net/pkt_cls.h>
 #include <net/sock.h>
 
 #include "dpaa2-eth.h"
@@ -2251,12 +2252,55 @@ static int dpaa2_eth_setup_mqprio(struct net_device *net_dev,
 	return 0;
 }
 
+#define bps_to_mbits(rate) (div_u64((rate), 1000000) * 8)
+
+static int dpaa2_eth_setup_tbf(struct net_device *net_dev, struct tc_tbf_qopt_offload *p)
+{
+	struct tc_tbf_qopt_offload_replace_params *cfg = &p->replace_params;
+	struct dpaa2_eth_priv *priv = netdev_priv(net_dev);
+	struct dpni_tx_shaping_cfg tx_cr_shaper = { 0 };
+	struct dpni_tx_shaping_cfg tx_er_shaper = { 0 };
+	int err;
+
+	if (p->command == TC_TBF_STATS)
+		return -EOPNOTSUPP;
+
+	/* Only per port Tx shaping */
+	if (p->parent != TC_H_ROOT)
+		return -EOPNOTSUPP;
+
+	if (p->command == TC_TBF_REPLACE) {
+		if (cfg->max_size > DPAA2_ETH_MAX_BURST_SIZE) {
+			netdev_err(net_dev, "burst size cannot be greater than %d\n",
+				   DPAA2_ETH_MAX_BURST_SIZE);
+			return -EINVAL;
+		}
+
+		tx_cr_shaper.max_burst_size = cfg->max_size;
+		/* The TBF interface is in bytes/s, whereas DPAA2 expects the
+		 * rate in Mbits/s
+		 */
+		tx_cr_shaper.rate_limit = bps_to_mbits(cfg->rate.rate_bytes_ps);
+	}
+
+	err = dpni_set_tx_shaping(priv->mc_io, 0, priv->mc_token, &tx_cr_shaper,
+				  &tx_er_shaper, 0);
+	if (err) {
+		netdev_err(net_dev, "dpni_set_tx_shaping() = %d\n", err);
+		return err;
+	}
+
+	return 0;
+}
+
 static int dpaa2_eth_setup_tc(struct net_device *net_dev,
 			      enum tc_setup_type type, void *type_data)
 {
 	switch (type) {
 	case TC_SETUP_QDISC_MQPRIO:
 		return dpaa2_eth_setup_mqprio(net_dev, type_data);
+	case TC_SETUP_QDISC_TBF:
+		return dpaa2_eth_setup_tbf(net_dev, type_data);
 	default:
 		return -EOPNOTSUPP;
 	}
@@ -3726,7 +3770,7 @@ static int netdev_init(struct net_device *net_dev)
 	net_dev->features = NETIF_F_RXCSUM |
 			    NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
 			    NETIF_F_SG | NETIF_F_HIGHDMA |
-			    NETIF_F_LLTX;
+			    NETIF_F_LLTX | NETIF_F_HW_TC;
 	net_dev->hw_features = net_dev->features;
 
 	return 0;

drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h

@@ -43,6 +43,9 @@
  */
 #define DPAA2_ETH_FQ_TAILDROP_THRESH	(1024 * 1024)
 
+/* Maximum burst size value for Tx shaping */
+#define DPAA2_ETH_MAX_BURST_SIZE	0xF7FF
+
 /* Maximum number of Tx confirmation frames to be processed
  * in a single NAPI call
  */