net: lan966x: Add support for apptrust

Make use of set/getapptrust() to implement per-selector trust
and trust order.
Reviewed-by: Daniel Machon <daniel.machon@microchip.com>
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

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

@@ -2,7 +2,49 @@
 
 #include "lan966x_main.h"
 
-static void lan966x_dcb_app_update(struct net_device *dev, bool enable)
+enum lan966x_dcb_apptrust_values {
+	LAN966X_DCB_APPTRUST_EMPTY,
+	LAN966X_DCB_APPTRUST_DSCP,
+	LAN966X_DCB_APPTRUST_PCP,
+	LAN966X_DCB_APPTRUST_DSCP_PCP,
+	__LAN966X_DCB_APPTRUST_MAX
+};
+
+static const struct lan966x_dcb_apptrust {
+	u8 selectors[IEEE_8021QAZ_APP_SEL_MAX + 1];
+	int nselectors;
+} *lan966x_port_apptrust[NUM_PHYS_PORTS];
+
+static const char *lan966x_dcb_apptrust_names[__LAN966X_DCB_APPTRUST_MAX] = {
+	[LAN966X_DCB_APPTRUST_EMPTY]    = "empty",
+	[LAN966X_DCB_APPTRUST_DSCP]     = "dscp",
+	[LAN966X_DCB_APPTRUST_PCP]      = "pcp",
+	[LAN966X_DCB_APPTRUST_DSCP_PCP] = "dscp pcp"
+};
+
+/* Lan966x supported apptrust policies */
+static const struct lan966x_dcb_apptrust
+	lan966x_dcb_apptrust_policies[__LAN966X_DCB_APPTRUST_MAX] = {
+	/* Empty *must* be first */
+	[LAN966X_DCB_APPTRUST_EMPTY]    = { { 0 }, 0 },
+	[LAN966X_DCB_APPTRUST_DSCP]     = { { IEEE_8021QAZ_APP_SEL_DSCP }, 1 },
+	[LAN966X_DCB_APPTRUST_PCP]      = { { DCB_APP_SEL_PCP }, 1 },
+	[LAN966X_DCB_APPTRUST_DSCP_PCP] = { { IEEE_8021QAZ_APP_SEL_DSCP,
+					      DCB_APP_SEL_PCP }, 2 },
+};
+
+static bool lan966x_dcb_apptrust_contains(int portno, u8 selector)
+{
+	const struct lan966x_dcb_apptrust *conf = lan966x_port_apptrust[portno];
+
+	for (int i = 0; i < conf->nselectors; i++)
+		if (conf->selectors[i] == selector)
+			return true;
+
+	return false;
+}
+
+static void lan966x_dcb_app_update(struct net_device *dev)
 {
 	struct lan966x_port *port = netdev_priv(dev);
 	struct lan966x_port_qos qos = {0};
@@ -15,7 +57,10 @@ static void lan966x_dcb_app_update(struct net_device *dev, bool enable)
 		qos.pcp.map[i] = dcb_getapp(dev, &app_itr);
 	}
 
-	qos.pcp.enable = enable;
+	/* Enable use of pcp for queue classification */
+	if (lan966x_dcb_apptrust_contains(port->chip_port, DCB_APP_SEL_PCP))
+		qos.pcp.enable = true;
+
 	lan966x_port_qos_set(port, &qos);
 }
 
@@ -52,7 +97,7 @@ static int lan966x_dcb_ieee_delapp(struct net_device *dev, struct dcb_app *app)
 	if (err < 0)
 		return err;
 
-	lan966x_dcb_app_update(dev, false);
+	lan966x_dcb_app_update(dev);
 
 	return 0;
 }
@@ -79,7 +124,67 @@ static int lan966x_dcb_ieee_setapp(struct net_device *dev, struct dcb_app *app)
 	if (err)
 		return err;
 
-	lan966x_dcb_app_update(dev, true);
+	lan966x_dcb_app_update(dev);
+
+	return 0;
+}
+
+static int lan966x_dcb_apptrust_validate(struct net_device *dev,
+					 u8 *selectors,
+					 int nselectors)
+{
+	for (int i = 0; i < ARRAY_SIZE(lan966x_dcb_apptrust_policies); i++) {
+		bool match;
+
+		if (lan966x_dcb_apptrust_policies[i].nselectors != nselectors)
+			continue;
+
+		match = true;
+		for (int j = 0; j < nselectors; j++) {
+			if (lan966x_dcb_apptrust_policies[i].selectors[j] !=
+			    *(selectors + j)) {
+				match = false;
+				break;
+			}
+		}
+		if (match)
+			return i;
+	}
+
+	netdev_err(dev, "Valid apptrust configurations are:\n");
+	for (int i = 0; i < ARRAY_SIZE(lan966x_dcb_apptrust_names); i++)
+		pr_info("order: %s\n", lan966x_dcb_apptrust_names[i]);
+
+	return -EOPNOTSUPP;
+}
+
+static int lan966x_dcb_setapptrust(struct net_device *dev,
+				   u8 *selectors,
+				   int nselectors)
+{
+	struct lan966x_port *port = netdev_priv(dev);
+	int idx;
+
+	idx = lan966x_dcb_apptrust_validate(dev, selectors, nselectors);
+	if (idx < 0)
+		return idx;
+
+	lan966x_port_apptrust[port->chip_port] = &lan966x_dcb_apptrust_policies[idx];
+	lan966x_dcb_app_update(dev);
+
+	return 0;
+}
+
+static int lan966x_dcb_getapptrust(struct net_device *dev, u8 *selectors,
+				   int *nselectors)
+{
+	struct lan966x_port *port = netdev_priv(dev);
+	const struct lan966x_dcb_apptrust *trust;
+
+	trust = lan966x_port_apptrust[port->chip_port];
+
+	memcpy(selectors, trust->selectors, trust->nselectors);
+	*nselectors = trust->nselectors;
 
 	return 0;
 }
@@ -87,6 +192,8 @@ static int lan966x_dcb_ieee_setapp(struct net_device *dev, struct dcb_app *app)
 static const struct dcbnl_rtnl_ops lan966x_dcbnl_ops = {
 	.ieee_setapp = lan966x_dcb_ieee_setapp,
 	.ieee_delapp = lan966x_dcb_ieee_delapp,
+	.dcbnl_setapptrust = lan966x_dcb_setapptrust,
+	.dcbnl_getapptrust = lan966x_dcb_getapptrust,
 };
 
 void lan966x_dcb_init(struct lan966x *lan966x)
@@ -99,5 +206,8 @@ void lan966x_dcb_init(struct lan966x *lan966x)
 			continue;
 
 		port->dev->dcbnl_ops = &lan966x_dcbnl_ops;
+
+		lan966x_port_apptrust[port->chip_port] =
+			&lan966x_dcb_apptrust_policies[LAN966X_DCB_APPTRUST_DSCP_PCP];
 	}
 }