2 files changed, 56 insertions, 29 deletions

diff --git a/include/net/pkt_sched.h b/include/net/pkt_sched.h
index 6c5e64e0a0bb..02e3ccfbc7d1 100644
--- a/include/net/pkt_sched.h
+++ b/include/net/pkt_sched.h
@@ -160,6 +160,10 @@ struct tc_etf_qopt_offload {
 	s32 queue;
 };
 
+struct tc_mqprio_caps {
+	bool validate_queue_counts:1;
+};
+
 struct tc_mqprio_qopt_offload {
 	/* struct tc_mqprio_qopt must always be the first element */
 	struct tc_mqprio_qopt qopt;
diff --git a/net/sched/sch_mqprio.c b/net/sched/sch_mqprio.c
index 25ab215641a2..0f04b17588ca 100644
--- a/net/sched/sch_mqprio.c
+++ b/net/sched/sch_mqprio.c
@@ -35,6 +35,35 @@ static bool intervals_overlap(int a, int b, int c, int d)
 	return left < right;
 }
 
+static int mqprio_validate_queue_counts(struct net_device *dev,
+					const struct tc_mqprio_qopt *qopt)
+{
+	int i, j;
+
+	for (i = 0; i < qopt->num_tc; i++) {
+		unsigned int last = qopt->offset[i] + qopt->count[i];
+
+		/* Verify the queue count is in tx range being equal to the
+		 * real_num_tx_queues indicates the last queue is in use.
+		 */
+		if (qopt->offset[i] >= dev->real_num_tx_queues ||
+		    !qopt->count[i] ||
+		    last > dev->real_num_tx_queues)
+			return -EINVAL;
+
+		/* Verify that the offset and counts do not overlap */
+		for (j = i + 1; j < qopt->num_tc; j++) {
+			if (intervals_overlap(qopt->offset[i], last,
+					      qopt->offset[j],
+					      qopt->offset[j] +
+					      qopt->count[j]))
+				return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
 static int mqprio_enable_offload(struct Qdisc *sch,
 				 const struct tc_mqprio_qopt *qopt)
 {
@@ -110,9 +139,10 @@ static void mqprio_destroy(struct Qdisc *sch)
 		netdev_set_num_tc(dev, 0);
 }
 
-static int mqprio_parse_opt(struct net_device *dev, struct tc_mqprio_qopt *qopt)
+static int mqprio_parse_opt(struct net_device *dev, struct tc_mqprio_qopt *qopt,
+			    const struct tc_mqprio_caps *caps)
 {
-	int i, j;
+	int i, err;
 
 	/* Verify num_tc is not out of max range */
 	if (qopt->num_tc > TC_MAX_QUEUE)
@@ -131,35 +161,24 @@ static int mqprio_parse_opt(struct net_device *dev, struct tc_mqprio_qopt *qopt)
 	if (qopt->hw > TC_MQPRIO_HW_OFFLOAD_MAX)
 		qopt->hw = TC_MQPRIO_HW_OFFLOAD_MAX;
 
-	/* If hardware offload is requested we will leave it to the device
-	 * to either populate the queue counts itself or to validate the
-	 * provided queue counts.  If ndo_setup_tc is not present then
-	 * hardware doesn't support offload and we should return an error.
+	/* If hardware offload is requested, we will leave 3 options to the
+	 * device driver:
+	 * - populate the queue counts itself (and ignore what was requested)
+	 * - validate the provided queue counts by itself (and apply them)
+	 * - request queue count validation here (and apply them)
 	 */
-	if (qopt->hw)
-		return dev->netdev_ops->ndo_setup_tc ? 0 : -EINVAL;
-
-	for (i = 0; i < qopt->num_tc; i++) {
-		unsigned int last = qopt->offset[i] + qopt->count[i];
-
-		/* Verify the queue count is in tx range being equal to the
-		 * real_num_tx_queues indicates the last queue is in use.
-		 */
-		if (qopt->offset[i] >= dev->real_num_tx_queues ||
-		    !qopt->count[i] ||
-		    last > dev->real_num_tx_queues)
-			return -EINVAL;
-
-		/* Verify that the offset and counts do not overlap */
-		for (j = i + 1; j < qopt->num_tc; j++) {
-			if (intervals_overlap(qopt->offset[i], last,
-					      qopt->offset[j],
-					      qopt->offset[j] +
-					      qopt->count[j]))
-				return -EINVAL;
-		}
+	if (!qopt->hw || caps->validate_queue_counts) {
+		err = mqprio_validate_queue_counts(dev, qopt);
+		if (err)
+			return err;
 	}
 
+	/* If ndo_setup_tc is not present then hardware doesn't support offload
+	 * and we should return an error.
+	 */
+	if (qopt->hw && !dev->netdev_ops->ndo_setup_tc)
+		return -EINVAL;
+
 	return 0;
 }
 
@@ -254,6 +273,7 @@ static int mqprio_init(struct Qdisc *sch, struct nlattr *opt,
 	struct Qdisc *qdisc;
 	int i, err = -EOPNOTSUPP;
 	struct tc_mqprio_qopt *qopt = NULL;
+	struct tc_mqprio_caps caps;
 	int len;
 
 	BUILD_BUG_ON(TC_MAX_QUEUE != TC_QOPT_MAX_QUEUE);
@@ -272,8 +292,11 @@ static int mqprio_init(struct Qdisc *sch, struct nlattr *opt,
 	if (!opt || nla_len(opt) < sizeof(*qopt))
 		return -EINVAL;
 
+	qdisc_offload_query_caps(dev, TC_SETUP_QDISC_MQPRIO,
+				 &caps, sizeof(caps));
+
 	qopt = nla_data(opt);
-	if (mqprio_parse_opt(dev, qopt))
+	if (mqprio_parse_opt(dev, qopt, &caps))
 		return -EINVAL;
 
 	len = nla_len(opt) - NLA_ALIGN(sizeof(*qopt));