[PATCH net-next v2 0/2] net: mvneta: implement basic MQPrio support

[PATCH net-next v2 0/2] net: mvneta: implement basic MQPrio support

[Maxime Chevallier]

Hi everyone,

This is V2 for the MQPrio support in mvneta.

This small series adds basic support for mqprio offloading, by having
the rx queueing mirroring the TCs based on VLAN prio fields.

This was tested on Armada 3700, and proves useful to make sure
high-priority traffic has a better chance not getting dropped when
there's lots of packets incoming.

The first patch of the series deals with the per-cpu interrupts on the
armada 3700. Since they don't work, there were already some patches
applied to keep all queue mappings to CPU0, but there still were some
remaining mappings left to be dealt with.

The second patch implements the MQPrio offloading for the receive path.

Changes in V2 :
 - Add a Fixes tag for the first patch
 - Fix some warnings and the xmas tree in the second patch

Thanks,

Maxime

Maxime Chevallier (2):
  net: mvneta: Remove per-cpu queue mapping for Armada 3700
  net: mvneta: Implement mqprio support

 drivers/net/ethernet/marvell/mvneta.c | 70 ++++++++++++++++++++++++++-
 1 file changed, 69 insertions(+), 1 deletion(-)

-- 
2.25.4

[PATCH net-next v2 1/2] net: mvneta: Remove per-cpu queue mapping for Armada 3700

[Maxime Chevallier]

According to Errata #23 "The per-CPU GbE interrupt is limited to Core
0", we can't use the per-cpu interrupt mechanism on the Armada 3700
familly.

This is correctly checked for RSS configuration, but the initial queue
mapping is still done by having the queues spread across all the CPUs in
the system, both in the init path and in the cpu_hotplug path.

Fixes: 2636ac3cc2b4 ("net: mvneta: Add network support for Armada 3700 SoC")
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
---
V2: Added Fixes tag, as per Pali's review

 drivers/net/ethernet/marvell/mvneta.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
index 6290bfb6494e..8e410fafff8d 100644
--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -3428,7 +3428,9 @@ static int mvneta_txq_sw_init(struct mvneta_port *pp,
 		return -ENOMEM;
 
 	/* Setup XPS mapping */
-	if (txq_number > 1)
+	if (pp->neta_armada3700)
+		cpu = 0;
+	else if (txq_number > 1)
 		cpu = txq->id % num_present_cpus();
 	else
 		cpu = pp->rxq_def % num_present_cpus();
@@ -4206,6 +4208,11 @@ static int mvneta_cpu_online(unsigned int cpu, struct hlist_node *node)
 						  node_online);
 	struct mvneta_pcpu_port *port = per_cpu_ptr(pp->ports, cpu);
 
+	/* Armada 3700's per-cpu interrupt for mvneta is broken, all interrupts
+	 * are routed to CPU 0, so we don't need all the cpu-hotplug support
+	 */
+	if (pp->neta_armada3700)
+		return 0;
 
 	spin_lock(&pp->lock);
 	/*
-- 
2.25.4

[PATCH net-next v2 2/2] net: mvneta: Implement mqprio support

[Maxime Chevallier]

Implement a basic MQPrio support, inserting rules in RX that translate
the TC to prio mapping into vlan prio to queues.

The TX logic stays the same as when we don't offload the qdisc.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
---
V2 : Fixed the reverse xmas tree, as per Andrew's review.
     Fixed a compile warning from the ktest bot

 drivers/net/ethernet/marvell/mvneta.c | 61 +++++++++++++++++++++++++++
 1 file changed, 61 insertions(+)

diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
index 8e410fafff8d..a635cf84608a 100644
--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -102,6 +102,8 @@
 #define      MVNETA_TX_NO_DATA_SWAP              BIT(5)
 #define      MVNETA_DESC_SWAP                    BIT(6)
 #define      MVNETA_TX_BRST_SZ_MASK(burst)       ((burst) << 22)
+#define	MVNETA_VLAN_PRIO_TO_RXQ			 0x2440
+#define      MVNETA_VLAN_PRIO_RXQ_MAP(prio, rxq) ((rxq) << ((prio) * 3))
 #define MVNETA_PORT_STATUS                       0x2444
 #define      MVNETA_TX_IN_PRGRS                  BIT(1)
 #define      MVNETA_TX_FIFO_EMPTY                BIT(8)
@@ -490,6 +492,7 @@ struct mvneta_port {
 	u8 mcast_count[256];
 	u16 tx_ring_size;
 	u16 rx_ring_size;
+	u8 prio_tc_map[8];
 
 	phy_interface_t phy_interface;
 	struct device_node *dn;
@@ -4922,6 +4925,63 @@ static int mvneta_ethtool_set_eee(struct net_device *dev,
 	return phylink_ethtool_set_eee(pp->phylink, eee);
 }
 
+static void mvneta_clear_rx_prio_map(struct mvneta_port *pp)
+{
+	mvreg_write(pp, MVNETA_VLAN_PRIO_TO_RXQ, 0);
+}
+
+static void mvneta_setup_rx_prio_map(struct mvneta_port *pp)
+{
+	u32 val = 0;
+	int i;
+
+	for (i = 0; i < rxq_number; i++)
+		val |= MVNETA_VLAN_PRIO_RXQ_MAP(i, pp->prio_tc_map[i]);
+
+	mvreg_write(pp, MVNETA_VLAN_PRIO_TO_RXQ, val);
+}
+
+static int mvneta_setup_mqprio(struct net_device *dev,
+			       struct tc_mqprio_qopt *qopt)
+{
+	struct mvneta_port *pp = netdev_priv(dev);
+	u8 num_tc;
+	int i;
+
+	qopt->hw = TC_MQPRIO_HW_OFFLOAD_TCS;
+	num_tc = qopt->num_tc;
+
+	if (num_tc > rxq_number)
+		return -EINVAL;
+
+	if (!num_tc) {
+		mvneta_clear_rx_prio_map(pp);
+		netdev_reset_tc(dev);
+		return 0;
+	}
+
+	memcpy(pp->prio_tc_map, qopt->prio_tc_map, sizeof(pp->prio_tc_map));
+
+	mvneta_setup_rx_prio_map(pp);
+
+	netdev_set_num_tc(dev, qopt->num_tc);
+	for (i = 0; i < qopt->num_tc; i++)
+		netdev_set_tc_queue(dev, i, qopt->count[i], qopt->offset[i]);
+
+	return 0;
+}
+
+static int mvneta_setup_tc(struct net_device *dev, enum tc_setup_type type,
+			   void *type_data)
+{
+	switch (type) {
+	case TC_SETUP_QDISC_MQPRIO:
+		return mvneta_setup_mqprio(dev, type_data);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
 static const struct net_device_ops mvneta_netdev_ops = {
 	.ndo_open            = mvneta_open,
 	.ndo_stop            = mvneta_stop,
@@ -4934,6 +4994,7 @@ static const struct net_device_ops mvneta_netdev_ops = {
 	.ndo_do_ioctl        = mvneta_ioctl,
 	.ndo_bpf	     = mvneta_xdp,
 	.ndo_xdp_xmit        = mvneta_xdp_xmit,
+	.ndo_setup_tc	     = mvneta_setup_tc,
 };
 
 static const struct ethtool_ops mvneta_eth_tool_ops = {
-- 
2.25.4