net: lan966x: Add support for offloading pcp table

Add support for offloading pcp app entries. Lan966x has 8 priority
queues per port and for each priority it also has a drop precedence.
Reviewed-by: Daniel Machon <daniel.machon@microchip.com>
Reviewed-by: Piotr Raczynski <piotr.raczynski@intel.com>
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

drivers/net/ethernet/microchip/lan966x/Kconfig

@@ -10,3 +10,14 @@ config LAN966X_SWITCH
 	select VCAP
 	help
 	  This driver supports the Lan966x network switch device.
+
+config LAN966X_DCB
+	bool "Data Center Bridging (DCB) support"
+	depends on LAN966X_SWITCH && DCB
+	default y
+	help
+	  Say Y here if you want to use Data Center Bridging (DCB) in the
+	  driver. This can be used to assign priority to traffic, based on
+	  DSCP and PCP.
+
+	  If unsure, set to Y.

drivers/net/ethernet/microchip/lan966x/Makefile

@@ -15,6 +15,7 @@ lan966x-switch-objs  := lan966x_main.o lan966x_phylink.o lan966x_port.o \
 			lan966x_xdp.o lan966x_vcap_impl.o lan966x_vcap_ag_api.o \
 			lan966x_tc_flower.o lan966x_goto.o
 
+lan966x-switch-$(CONFIG_LAN966X_DCB) += lan966x_dcb.o
 lan966x-switch-$(CONFIG_DEBUG_FS) += lan966x_vcap_debugfs.o
 
 # Provide include files

drivers/net/ethernet/microchip/lan966x/lan966x_dcb.c

+// SPDX-License-Identifier: GPL-2.0+
+
+#include "lan966x_main.h"
+
+static void lan966x_dcb_app_update(struct net_device *dev, bool enable)
+{
+	struct lan966x_port *port = netdev_priv(dev);
+	struct lan966x_port_qos qos = {0};
+	struct dcb_app app_itr;
+
+	/* Get pcp ingress mapping */
+	for (int i = 0; i < ARRAY_SIZE(qos.pcp.map); i++) {
+		app_itr.selector = DCB_APP_SEL_PCP;
+		app_itr.protocol = i;
+		qos.pcp.map[i] = dcb_getapp(dev, &app_itr);
+	}
+
+	qos.pcp.enable = enable;
+	lan966x_port_qos_set(port, &qos);
+}
+
+static int lan966x_dcb_app_validate(struct net_device *dev,
+				    const struct dcb_app *app)
+{
+	int err = 0;
+
+	switch (app->selector) {
+	/* Pcp checks */
+	case DCB_APP_SEL_PCP:
+		if (app->protocol >= LAN966X_PORT_QOS_PCP_DEI_COUNT)
+			err = -EINVAL;
+		else if (app->priority >= NUM_PRIO_QUEUES)
+			err = -ERANGE;
+		break;
+	default:
+		err = -EINVAL;
+		break;
+	}
+
+	if (err)
+		netdev_err(dev, "Invalid entry: %d:%d\n", app->protocol,
+			   app->priority);
+
+	return err;
+}
+
+static int lan966x_dcb_ieee_delapp(struct net_device *dev, struct dcb_app *app)
+{
+	int err;
+
+	err = dcb_ieee_delapp(dev, app);
+	if (err < 0)
+		return err;
+
+	lan966x_dcb_app_update(dev, false);
+
+	return 0;
+}
+
+static int lan966x_dcb_ieee_setapp(struct net_device *dev, struct dcb_app *app)
+{
+	struct dcb_app app_itr;
+	int err;
+	u8 prio;
+
+	err = lan966x_dcb_app_validate(dev, app);
+	if (err)
+		return err;
+
+	/* Delete current mapping, if it exists */
+	prio = dcb_getapp(dev, app);
+	if (prio) {
+		app_itr = *app;
+		app_itr.priority = prio;
+		dcb_ieee_delapp(dev, &app_itr);
+	}
+
+	err = dcb_ieee_setapp(dev, app);
+	if (err)
+		return err;
+
+	lan966x_dcb_app_update(dev, true);
+
+	return 0;
+}
+
+static const struct dcbnl_rtnl_ops lan966x_dcbnl_ops = {
+	.ieee_setapp = lan966x_dcb_ieee_setapp,
+	.ieee_delapp = lan966x_dcb_ieee_delapp,
+};
+
+void lan966x_dcb_init(struct lan966x *lan966x)
+{
+	for (int p = 0; p < lan966x->num_phys_ports; ++p) {
+		struct lan966x_port *port;
+
+		port = lan966x->ports[p];
+		if (!port)
+			continue;
+
+		port->dev->dcbnl_ops = &lan966x_dcbnl_ops;
+	}
+}

drivers/net/ethernet/microchip/lan966x/lan966x_main.c

@@ -1213,6 +1213,8 @@ static int lan966x_probe(struct platform_device *pdev)
 	if (err)
 		goto cleanup_fdma;
 
+	lan966x_dcb_init(lan966x);
+
 	return 0;
 
 cleanup_fdma:

drivers/net/ethernet/microchip/lan966x/lan966x_main.h

@@ -104,6 +104,11 @@
 #define LAN966X_VCAP_CID_ES0_L0 VCAP_CID_EGRESS_L0 /* ES0 lookup 0 */
 #define LAN966X_VCAP_CID_ES0_MAX (VCAP_CID_EGRESS_L1 - 1) /* ES0 Max */
 
+#define LAN966X_PORT_QOS_PCP_COUNT	8
+#define LAN966X_PORT_QOS_DEI_COUNT	8
+#define LAN966X_PORT_QOS_PCP_DEI_COUNT \
+	(LAN966X_PORT_QOS_PCP_COUNT + LAN966X_PORT_QOS_DEI_COUNT)
+
 /* MAC table entry types.
  * ENTRYTYPE_NORMAL is subject to aging.
  * ENTRYTYPE_LOCKED is not subject to aging.
@@ -392,6 +397,15 @@ struct lan966x_port_tc {
 	struct flow_stats mirror_stat;
 };
 
+struct lan966x_port_qos_pcp {
+	u8 map[LAN966X_PORT_QOS_PCP_DEI_COUNT];
+	bool enable;
+};
+
+struct lan966x_port_qos {
+	struct lan966x_port_qos_pcp pcp;
+};
+
 struct lan966x_port {
 	struct net_device *dev;
 	struct lan966x *lan966x;
@@ -456,6 +470,9 @@ int lan966x_port_pcs_set(struct lan966x_port *port,
 			 struct lan966x_port_config *config);
 void lan966x_port_init(struct lan966x_port *port);
 
+void lan966x_port_qos_set(struct lan966x_port *port,
+			  struct lan966x_port_qos *qos);
+
 int lan966x_mac_ip_learn(struct lan966x *lan966x,
 			 bool cpu_copy,
 			 const unsigned char mac[ETH_ALEN],
@@ -680,6 +697,14 @@ int lan966x_goto_port_del(struct lan966x_port *port,
 			  unsigned long goto_id,
 			  struct netlink_ext_ack *extack);
 
+#ifdef CONFIG_LAN966X_DCB
+void lan966x_dcb_init(struct lan966x *lan966x);
+#else
+static inline void lan966x_dcb_init(struct lan966x *lan966x)
+{
+}
+#endif
+
 static inline void __iomem *lan_addr(void __iomem *base[],
 				     int id, int tinst, int tcnt,
 				     int gbase, int ginst,

drivers/net/ethernet/microchip/lan966x/lan966x_port.c

@@ -394,6 +394,36 @@ int lan966x_port_pcs_set(struct lan966x_port *port,
 	return 0;
 }
 
+static void lan966x_port_qos_pcp_set(struct lan966x_port *port,
+				     struct lan966x_port_qos_pcp *qos)
+{
+	u8 *pcp_itr = qos->map;
+	u8 pcp, dp;
+
+	lan_rmw(ANA_QOS_CFG_QOS_PCP_ENA_SET(qos->enable),
+		ANA_QOS_CFG_QOS_PCP_ENA,
+		port->lan966x, ANA_QOS_CFG(port->chip_port));
+
+	/* Map PCP and DEI to priority */
+	for (int i = 0; i < ARRAY_SIZE(qos->map); i++) {
+		pcp = *(pcp_itr + i);
+		dp = (i < LAN966X_PORT_QOS_PCP_COUNT) ? 0 : 1;
+
+		lan_rmw(ANA_PCP_DEI_CFG_QOS_PCP_DEI_VAL_SET(pcp) |
+			ANA_PCP_DEI_CFG_DP_PCP_DEI_VAL_SET(dp),
+			ANA_PCP_DEI_CFG_QOS_PCP_DEI_VAL |
+			ANA_PCP_DEI_CFG_DP_PCP_DEI_VAL,
+			port->lan966x,
+			ANA_PCP_DEI_CFG(port->chip_port, i));
+	}
+}
+
+void lan966x_port_qos_set(struct lan966x_port *port,
+			  struct lan966x_port_qos *qos)
+{
+	lan966x_port_qos_pcp_set(port, &qos->pcp);
+}
+
 void lan966x_port_init(struct lan966x_port *port)
 {
 	struct lan966x_port_config *config = &port->config;