net: airoha: Introduce WAN device flag

Introduce WAN flag to specify if a given device is used to transmit/receive
WAN or LAN traffic. Current codebase supports specifying LAN/WAN device
configuration in ndo_init() callback during device bootstrap.
In order to consider setups where LAN configuration is used even for
GDM3/GDM4 devices, check airoha_is_lan_gdm_dev() to select pse_port in
airoha_ppe_foe_entry_prepare().
Please note after this patch, it will be possible to specify multiple LAN
devices but just a single WAN one. Please note this change is not visible
to the user since airoha_eth driver currently supports just the internal
phy available via the MT7530 DSA switch and there are no WAN interfaces
officially supported since PCS/external phy is not merged mainline yet
(it will be posted with following patches).

Tested-by: Xuegang Lu <xuegang.lu@airoha.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://patch.msgid.link/20260603-airoha-eth-multi-serdes-v9-5-5d476bc2f426@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

3 files changed, 66 insertions, 22 deletions

diff --git a/drivers/net/ethernet/airoha/airoha_eth.c b/drivers/net/ethernet/airoha/airoha_eth.c
index 4509281c3c7b..402aa1d33d33 100644
--- a/drivers/net/ethernet/airoha/airoha_eth.c
+++ b/drivers/net/ethernet/airoha/airoha_eth.c
@@ -1899,36 +1899,81 @@ static int airoha_enable_gdm2_loopback(struct airoha_gdm_dev *dev)
 	return 0;
 }
 
-static int airoha_dev_init(struct net_device *netdev)
+static struct airoha_gdm_dev *
+airoha_get_wan_gdm_dev(struct airoha_eth *eth)
 {
-	struct airoha_gdm_dev *dev = netdev_priv(netdev);
-	struct airoha_gdm_port *port = dev->port;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(eth->ports); i++) {
+		struct airoha_gdm_port *port = eth->ports[i];
+		int j;
+
+		if (!port)
+			continue;
+
+		for (j = 0; j < ARRAY_SIZE(port->devs); j++) {
+			struct airoha_gdm_dev *dev = port->devs[j];
+
+			if (dev && !airoha_is_lan_gdm_dev(dev))
+				return dev;
+		}
+	}
+
+	return NULL;
+}
+
+static void airoha_dev_set_qdma(struct airoha_gdm_dev *dev)
+{
+	struct net_device *netdev = netdev_from_priv(dev);
 	struct airoha_eth *eth = dev->eth;
 	int ppe_id;
 
 	/* QDMA0 is used for lan ports while QDMA1 is used for WAN ports */
 	dev->qdma = &eth->qdma[!airoha_is_lan_gdm_dev(dev)];
 	netdev->irq = dev->qdma->irq_banks[0].irq;
-	airoha_set_macaddr(dev, netdev->dev_addr);
+
+	ppe_id = !airoha_is_lan_gdm_dev(dev) && airoha_ppe_is_enabled(eth, 1);
+	airoha_ppe_set_cpu_port(dev, ppe_id, airoha_get_fe_port(dev));
+}
+
+static int airoha_dev_init(struct net_device *netdev)
+{
+	struct airoha_gdm_dev *dev = netdev_priv(netdev);
+	struct airoha_gdm_port *port = dev->port;
 
 	switch (port->id) {
 	case AIROHA_GDM3_IDX:
-	case AIROHA_GDM4_IDX:
-		/* If GDM2 is active we can't enable loopback */
-		if (!eth->ports[1]) {
-			int err;
+	case AIROHA_GDM4_IDX: {
+		struct airoha_eth *eth = dev->eth;
 
-			err = airoha_enable_gdm2_loopback(dev);
-			if (err)
-				return err;
-		}
+		/* GDM2 supports a single net_device */
+		if (eth->ports[1] && eth->ports[1]->devs[0])
+			break;
+
+		if (airoha_get_wan_gdm_dev(eth))
+			break;
+
+		fallthrough;
+	}
+	case AIROHA_GDM2_IDX:
+		/* GDM2 is always used as wan */
+		dev->flags |= AIROHA_PRIV_F_WAN;
 		break;
 	default:
 		break;
 	}
 
-	ppe_id = !airoha_is_lan_gdm_dev(dev) && airoha_ppe_is_enabled(eth, 1);
-	airoha_ppe_set_cpu_port(dev, ppe_id, airoha_get_fe_port(dev));
+	airoha_dev_set_qdma(dev);
+	airoha_set_macaddr(dev, netdev->dev_addr);
+
+	if (!airoha_is_lan_gdm_dev(dev) &&
+	    (port->id == AIROHA_GDM3_IDX || port->id == AIROHA_GDM4_IDX)) {
+		int err;
+
+		err = airoha_enable_gdm2_loopback(dev);
+		if (err)
+			return err;
+	}
 
 	return 0;
 }
diff --git a/drivers/net/ethernet/airoha/airoha_eth.h b/drivers/net/ethernet/airoha/airoha_eth.h
index 666e9246e70e..3e8262f583a7 100644
--- a/drivers/net/ethernet/airoha/airoha_eth.h
+++ b/drivers/net/ethernet/airoha/airoha_eth.h
@@ -538,6 +538,10 @@ struct airoha_qdma {
 	DECLARE_BITMAP(qos_channel_map, AIROHA_NUM_QOS_CHANNELS);
 };
 
+enum airoha_priv_flags {
+	AIROHA_PRIV_F_WAN = BIT(0),
+};
+
 struct airoha_gdm_dev {
 	struct airoha_gdm_port *port;
 	struct airoha_qdma *qdma;
@@ -548,6 +552,7 @@ struct airoha_gdm_dev {
 	u64 cpu_tx_packets;
 	u64 fwd_tx_packets;
 
+	u32 flags;
 	int nbq;
 };
 
@@ -654,13 +659,7 @@ static inline u16 airoha_qdma_get_txq(struct airoha_qdma *qdma, u16 qid)
 
 static inline bool airoha_is_lan_gdm_dev(struct airoha_gdm_dev *dev)
 {
-	struct airoha_gdm_port *port = dev->port;
-
-	/* GDM1 port on EN7581 SoC is connected to the lan dsa switch.
-	 * GDM{2,3,4} can be used as wan port connected to an external
-	 * phy module.
-	 */
-	return port->id == 1;
+	return !(dev->flags & AIROHA_PRIV_F_WAN);
 }
 
 static inline bool airoha_is_7581(struct airoha_eth *eth)
diff --git a/drivers/net/ethernet/airoha/airoha_ppe.c b/drivers/net/ethernet/airoha/airoha_ppe.c
index 96abf451fdac..f54622904733 100644
--- a/drivers/net/ethernet/airoha/airoha_ppe.c
+++ b/drivers/net/ethernet/airoha/airoha_ppe.c
@@ -355,7 +355,7 @@ static int airoha_ppe_foe_entry_prepare(struct airoha_eth *eth,
 				return -EINVAL;
 
 			port = dev->port;
-			if (dsa_port >= 0 || eth->ports[1])
+			if (dsa_port >= 0 || airoha_is_lan_gdm_dev(dev))
 				pse_port = port->id == 4 ? FE_PSE_PORT_GDM4
 							 : port->id;
 			else