net: sched: Make TBF Qdisc offloadable

Invoke ndo_setup_tc as appropriate to signal init / replacement, destroying
and dumping of TBF Qdisc.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/netdevice.h

@@ -850,6 +850,7 @@ enum tc_setup_type {
 	TC_SETUP_QDISC_TAPRIO,
 	TC_SETUP_FT,
 	TC_SETUP_QDISC_ETS,
+	TC_SETUP_QDISC_TBF,
 };
 
 /* These structures hold the attributes of bpf state that are being passed

include/net/pkt_cls.h

@@ -854,4 +854,26 @@ struct tc_ets_qopt_offload {
 	};
 };
 
+enum tc_tbf_command {
+	TC_TBF_REPLACE,
+	TC_TBF_DESTROY,
+	TC_TBF_STATS,
+};
+
+struct tc_tbf_qopt_offload_replace_params {
+	struct psched_ratecfg rate;
+	u32 max_size;
+	struct gnet_stats_queue *qstats;
+};
+
+struct tc_tbf_qopt_offload {
+	enum tc_tbf_command command;
+	u32 handle;
+	u32 parent;
+	union {
+		struct tc_tbf_qopt_offload_replace_params replace_params;
+		struct tc_qopt_offload_stats stats;
+	};
+};
+
 #endif

net/sched/sch_tbf.c

@@ -15,6 +15,7 @@
 #include <linux/skbuff.h>
 #include <net/netlink.h>
 #include <net/sch_generic.h>
+#include <net/pkt_cls.h>
 #include <net/pkt_sched.h>
 
 
@@ -137,6 +138,52 @@ static u64 psched_ns_t2l(const struct psched_ratecfg *r,
 	return len;
 }
 
+static void tbf_offload_change(struct Qdisc *sch)
+{
+	struct tbf_sched_data *q = qdisc_priv(sch);
+	struct net_device *dev = qdisc_dev(sch);
+	struct tc_tbf_qopt_offload qopt;
+
+	if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc)
+		return;
+
+	qopt.command = TC_TBF_REPLACE;
+	qopt.handle = sch->handle;
+	qopt.parent = sch->parent;
+	qopt.replace_params.rate = q->rate;
+	qopt.replace_params.max_size = q->max_size;
+	qopt.replace_params.qstats = &sch->qstats;
+
+	dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_TBF, &qopt);
+}
+
+static void tbf_offload_destroy(struct Qdisc *sch)
+{
+	struct net_device *dev = qdisc_dev(sch);
+	struct tc_tbf_qopt_offload qopt;
+
+	if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc)
+		return;
+
+	qopt.command = TC_TBF_DESTROY;
+	qopt.handle = sch->handle;
+	qopt.parent = sch->parent;
+	dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_TBF, &qopt);
+}
+
+static int tbf_offload_dump(struct Qdisc *sch)
+{
+	struct tc_tbf_qopt_offload qopt;
+
+	qopt.command = TC_TBF_STATS;
+	qopt.handle = sch->handle;
+	qopt.parent = sch->parent;
+	qopt.stats.bstats = &sch->bstats;
+	qopt.stats.qstats = &sch->qstats;
+
+	return qdisc_offload_dump_helper(sch, TC_SETUP_QDISC_TBF, &qopt);
+}
+
 /* GSO packet is too big, segment it so that tbf can transmit
  * each segment in time
  */
@@ -407,6 +454,8 @@ static int tbf_change(struct Qdisc *sch, struct nlattr *opt,
 
 	sch_tree_unlock(sch);
 	err = 0;
+
+	tbf_offload_change(sch);
 done:
 	return err;
 }
@@ -432,6 +481,7 @@ static void tbf_destroy(struct Qdisc *sch)
 	struct tbf_sched_data *q = qdisc_priv(sch);
 
 	qdisc_watchdog_cancel(&q->watchdog);
+	tbf_offload_destroy(sch);
 	qdisc_put(q->qdisc);
 }
 
@@ -440,6 +490,11 @@ static int tbf_dump(struct Qdisc *sch, struct sk_buff *skb)
 	struct tbf_sched_data *q = qdisc_priv(sch);
 	struct nlattr *nest;
 	struct tc_tbf_qopt opt;
+	int err;
+
+	err = tbf_offload_dump(sch);
+	if (err)
+		return err;
 
 	nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
 	if (nest == NULL)