Merge branch 'dsa-felix-qos'

Vladimir Oltean says:

====================
Basic QoS classification on Felix DSA switch using dcbnl

Basic QoS classification for Ocelot switches means port-based default
priority, DSCP-based and VLAN PCP based. This is opposed to advanced QoS
classification which is done through the VCAP IS1 TCAM based engine.

The patch set is a logical continuation of this RFC which attempted to
describe the default-prio as a matchall entry placed at the end of a
series of offloaded tc filters:
https://patchwork.kernel.org/project/netdevbpf/cover/20210113154139.1803705-1-olteanv@gmail.com/

I have tried my best to satisfy the feedback that we should cater for
pre-configured QoS profiles. Ironically, the only pre-configured QoS
profile that the Felix switch driver has is for VLAN PCP (1:1 mapping
with QoS class), yet IEEE 802.1Q or dcbnl offer no mechanism for
reporting or changing that.

Testing was done with the iproute2 dcb app. The qos_class of packets was
dumped from net/dsa/tag_ocelot.c.

(1) $ dcb app show dev swp3
default-prio 0
(2) $ dcb app replace dev swp3 default-prio 3
(3) $ dcb app replace dev swp3 dscp-prio CS3:5
(4) $ dcb app replace dev swp3 dscp-prio CS2:2
(5) $ dcb app show dev swp3
default-prio 3
dscp-prio CS2:2 CS3:5

Traffic sent with "ping -Q 64 <ipaddr>", which means CS2.
These packets match qos_class 0 after command (1),
qos_class 3 after command (2),
qos_class 3 after command (3), and
qos_class 2 after command (2).
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/ocelot/felix.c

@@ -1799,6 +1799,44 @@ felix_mrp_del_ring_role(struct dsa_switch *ds, int port,
 	return ocelot_mrp_del_ring_role(ocelot, port, mrp);
 }
 
+static int felix_port_get_default_prio(struct dsa_switch *ds, int port)
+{
+	struct ocelot *ocelot = ds->priv;
+
+	return ocelot_port_get_default_prio(ocelot, port);
+}
+
+static int felix_port_set_default_prio(struct dsa_switch *ds, int port,
+				       u8 prio)
+{
+	struct ocelot *ocelot = ds->priv;
+
+	return ocelot_port_set_default_prio(ocelot, port, prio);
+}
+
+static int felix_port_get_dscp_prio(struct dsa_switch *ds, int port, u8 dscp)
+{
+	struct ocelot *ocelot = ds->priv;
+
+	return ocelot_port_get_dscp_prio(ocelot, port, dscp);
+}
+
+static int felix_port_add_dscp_prio(struct dsa_switch *ds, int port, u8 dscp,
+				    u8 prio)
+{
+	struct ocelot *ocelot = ds->priv;
+
+	return ocelot_port_add_dscp_prio(ocelot, port, dscp, prio);
+}
+
+static int felix_port_del_dscp_prio(struct dsa_switch *ds, int port, u8 dscp,
+				    u8 prio)
+{
+	struct ocelot *ocelot = ds->priv;
+
+	return ocelot_port_del_dscp_prio(ocelot, port, dscp, prio);
+}
+
 const struct dsa_switch_ops felix_switch_ops = {
 	.get_tag_protocol		= felix_get_tag_protocol,
 	.change_tag_protocol		= felix_change_tag_protocol,
@@ -1862,6 +1900,11 @@ const struct dsa_switch_ops felix_switch_ops = {
 	.port_mrp_del_ring_role		= felix_mrp_del_ring_role,
 	.tag_8021q_vlan_add		= felix_tag_8021q_vlan_add,
 	.tag_8021q_vlan_del		= felix_tag_8021q_vlan_del,
+	.port_get_default_prio		= felix_port_get_default_prio,
+	.port_set_default_prio		= felix_port_set_default_prio,
+	.port_get_dscp_prio		= felix_port_get_dscp_prio,
+	.port_add_dscp_prio		= felix_port_add_dscp_prio,
+	.port_del_dscp_prio		= felix_port_del_dscp_prio,
 };
 
 struct net_device *felix_port_to_netdev(struct ocelot *ocelot, int port)

drivers/net/ethernet/mscc/ocelot.c

@@ -2907,6 +2907,122 @@ void ocelot_port_bridge_flags(struct ocelot *ocelot, int port,
 }
 EXPORT_SYMBOL(ocelot_port_bridge_flags);
 
+int ocelot_port_get_default_prio(struct ocelot *ocelot, int port)
+{
+	int val = ocelot_read_gix(ocelot, ANA_PORT_QOS_CFG, port);
+
+	return ANA_PORT_QOS_CFG_QOS_DEFAULT_VAL_X(val);
+}
+EXPORT_SYMBOL_GPL(ocelot_port_get_default_prio);
+
+int ocelot_port_set_default_prio(struct ocelot *ocelot, int port, u8 prio)
+{
+	if (prio >= IEEE_8021QAZ_MAX_TCS)
+		return -ERANGE;
+
+	ocelot_rmw_gix(ocelot,
+		       ANA_PORT_QOS_CFG_QOS_DEFAULT_VAL(prio),
+		       ANA_PORT_QOS_CFG_QOS_DEFAULT_VAL_M,
+		       ANA_PORT_QOS_CFG,
+		       port);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ocelot_port_set_default_prio);
+
+int ocelot_port_get_dscp_prio(struct ocelot *ocelot, int port, u8 dscp)
+{
+	int qos_cfg = ocelot_read_gix(ocelot, ANA_PORT_QOS_CFG, port);
+	int dscp_cfg = ocelot_read_rix(ocelot, ANA_DSCP_CFG, dscp);
+
+	/* Return error if DSCP prioritization isn't enabled */
+	if (!(qos_cfg & ANA_PORT_QOS_CFG_QOS_DSCP_ENA))
+		return -EOPNOTSUPP;
+
+	if (qos_cfg & ANA_PORT_QOS_CFG_DSCP_TRANSLATE_ENA) {
+		dscp = ANA_DSCP_CFG_DSCP_TRANSLATE_VAL_X(dscp_cfg);
+		/* Re-read ANA_DSCP_CFG for the translated DSCP */
+		dscp_cfg = ocelot_read_rix(ocelot, ANA_DSCP_CFG, dscp);
+	}
+
+	/* If the DSCP value is not trusted, the QoS classification falls back
+	 * to VLAN PCP or port-based default.
+	 */
+	if (!(dscp_cfg & ANA_DSCP_CFG_DSCP_TRUST_ENA))
+		return -EOPNOTSUPP;
+
+	return ANA_DSCP_CFG_QOS_DSCP_VAL_X(dscp_cfg);
+}
+EXPORT_SYMBOL_GPL(ocelot_port_get_dscp_prio);
+
+int ocelot_port_add_dscp_prio(struct ocelot *ocelot, int port, u8 dscp, u8 prio)
+{
+	int mask, val;
+
+	if (prio >= IEEE_8021QAZ_MAX_TCS)
+		return -ERANGE;
+
+	/* There is at least one app table priority (this one), so we need to
+	 * make sure DSCP prioritization is enabled on the port.
+	 * Also make sure DSCP translation is disabled
+	 * (dcbnl doesn't support it).
+	 */
+	mask = ANA_PORT_QOS_CFG_QOS_DSCP_ENA |
+	       ANA_PORT_QOS_CFG_DSCP_TRANSLATE_ENA;
+
+	ocelot_rmw_gix(ocelot, ANA_PORT_QOS_CFG_QOS_DSCP_ENA, mask,
+		       ANA_PORT_QOS_CFG, port);
+
+	/* Trust this DSCP value and map it to the given QoS class */
+	val = ANA_DSCP_CFG_DSCP_TRUST_ENA | ANA_DSCP_CFG_QOS_DSCP_VAL(prio);
+
+	ocelot_write_rix(ocelot, val, ANA_DSCP_CFG, dscp);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ocelot_port_add_dscp_prio);
+
+int ocelot_port_del_dscp_prio(struct ocelot *ocelot, int port, u8 dscp, u8 prio)
+{
+	int dscp_cfg = ocelot_read_rix(ocelot, ANA_DSCP_CFG, dscp);
+	int mask, i;
+
+	/* During a "dcb app replace" command, the new app table entry will be
+	 * added first, then the old one will be deleted. But the hardware only
+	 * supports one QoS class per DSCP value (duh), so if we blindly delete
+	 * the app table entry for this DSCP value, we end up deleting the
+	 * entry with the new priority. Avoid that by checking whether user
+	 * space wants to delete the priority which is currently configured, or
+	 * something else which is no longer current.
+	 */
+	if (ANA_DSCP_CFG_QOS_DSCP_VAL_X(dscp_cfg) != prio)
+		return 0;
+
+	/* Untrust this DSCP value */
+	ocelot_write_rix(ocelot, 0, ANA_DSCP_CFG, dscp);
+
+	for (i = 0; i < 64; i++) {
+		int dscp_cfg = ocelot_read_rix(ocelot, ANA_DSCP_CFG, i);
+
+		/* There are still app table entries on the port, so we need to
+		 * keep DSCP enabled, nothing to do.
+		 */
+		if (dscp_cfg & ANA_DSCP_CFG_DSCP_TRUST_ENA)
+			return 0;
+	}
+
+	/* Disable DSCP QoS classification if there isn't any trusted
+	 * DSCP value left.
+	 */
+	mask = ANA_PORT_QOS_CFG_QOS_DSCP_ENA |
+	       ANA_PORT_QOS_CFG_DSCP_TRANSLATE_ENA;
+
+	ocelot_rmw_gix(ocelot, 0, mask, ANA_PORT_QOS_CFG, port);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ocelot_port_del_dscp_prio);
+
 void ocelot_init_port(struct ocelot *ocelot, int port)
 {
 	struct ocelot_port *ocelot_port = ocelot->ports[port];

include/net/dsa.h

@@ -892,6 +892,18 @@ struct dsa_switch_ops {
 	int	(*get_ts_info)(struct dsa_switch *ds, int port,
 			       struct ethtool_ts_info *ts);
 
+	/*
+	 * DCB ops
+	 */
+	int	(*port_get_default_prio)(struct dsa_switch *ds, int port);
+	int	(*port_set_default_prio)(struct dsa_switch *ds, int port,
+					 u8 prio);
+	int	(*port_get_dscp_prio)(struct dsa_switch *ds, int port, u8 dscp);
+	int	(*port_add_dscp_prio)(struct dsa_switch *ds, int port, u8 dscp,
+				      u8 prio);
+	int	(*port_del_dscp_prio)(struct dsa_switch *ds, int port, u8 dscp,
+				      u8 prio);
+
 	/*
 	 * Suspend and resume
 	 */

include/soc/mscc/ocelot.h

@@ -869,6 +869,11 @@ int ocelot_port_pre_bridge_flags(struct ocelot *ocelot, int port,
 				 struct switchdev_brport_flags val);
 void ocelot_port_bridge_flags(struct ocelot *ocelot, int port,
 			      struct switchdev_brport_flags val);
+int ocelot_port_get_default_prio(struct ocelot *ocelot, int port);
+int ocelot_port_set_default_prio(struct ocelot *ocelot, int port, u8 prio);
+int ocelot_port_get_dscp_prio(struct ocelot *ocelot, int port, u8 dscp);
+int ocelot_port_add_dscp_prio(struct ocelot *ocelot, int port, u8 dscp, u8 prio);
+int ocelot_port_del_dscp_prio(struct ocelot *ocelot, int port, u8 dscp, u8 prio);
 int ocelot_port_bridge_join(struct ocelot *ocelot, int port,
 			    struct net_device *bridge, int bridge_num,
 			    struct netlink_ext_ack *extack);