net: mscc: ocelot: add support for mqprio offload

This doesn't apply anything to hardware and in general doesn't do
anything that the software variant doesn't do, except for checking that
there isn't more than 1 TXQ per TC (TXQs for a DSA switch are a dubious
concept anyway). The reason we add this is to be able to parse one more
field added to struct tc_mqprio_qopt_offload, namely preemptible_tcs.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Ferenc Fejes <fejes@inf.elte.hu>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 50 insertions, 0 deletions

diff --git a/drivers/net/ethernet/mscc/ocelot.c b/drivers/net/ethernet/mscc/ocelot.c
index 1502bb2c8ea7..8dc5fb1bc61b 100644
--- a/drivers/net/ethernet/mscc/ocelot.c
+++ b/drivers/net/ethernet/mscc/ocelot.c
@@ -8,6 +8,7 @@
 #include <linux/if_bridge.h>
 #include <linux/iopoll.h>
 #include <linux/phy/phy.h>
+#include <net/pkt_sched.h>
 #include <soc/mscc/ocelot_hsio.h>
 #include <soc/mscc/ocelot_vcap.h>
 #include "ocelot.h"
@@ -2699,6 +2700,55 @@ void ocelot_port_mirror_del(struct ocelot *ocelot, int from, bool ingress)
 }
 EXPORT_SYMBOL_GPL(ocelot_port_mirror_del);
 
+static void ocelot_port_reset_mqprio(struct ocelot *ocelot, int port)
+{
+	struct net_device *dev = ocelot->ops->port_to_netdev(ocelot, port);
+
+	netdev_reset_tc(dev);
+}
+
+int ocelot_port_mqprio(struct ocelot *ocelot, int port,
+		       struct tc_mqprio_qopt_offload *mqprio)
+{
+	struct net_device *dev = ocelot->ops->port_to_netdev(ocelot, port);
+	struct netlink_ext_ack *extack = mqprio->extack;
+	struct tc_mqprio_qopt *qopt = &mqprio->qopt;
+	int num_tc = qopt->num_tc;
+	int tc, err;
+
+	if (!num_tc) {
+		ocelot_port_reset_mqprio(ocelot, port);
+		return 0;
+	}
+
+	err = netdev_set_num_tc(dev, num_tc);
+	if (err)
+		return err;
+
+	for (tc = 0; tc < num_tc; tc++) {
+		if (qopt->count[tc] != 1) {
+			NL_SET_ERR_MSG_MOD(extack,
+					   "Only one TXQ per TC supported");
+			return -EINVAL;
+		}
+
+		err = netdev_set_tc_queue(dev, tc, 1, qopt->offset[tc]);
+		if (err)
+			goto err_reset_tc;
+	}
+
+	err = netif_set_real_num_tx_queues(dev, num_tc);
+	if (err)
+		goto err_reset_tc;
+
+	return 0;
+
+err_reset_tc:
+	ocelot_port_reset_mqprio(ocelot, port);
+	return err;
+}
+EXPORT_SYMBOL_GPL(ocelot_port_mqprio);
+
 void ocelot_init_port(struct ocelot *ocelot, int port)
 {
 	struct ocelot_port *ocelot_port = ocelot->ports[port];