net: airoha: Add loopback support for GDM2

Enable hw redirection for traffic received on GDM2 port to GDM{3,4}.
This is required to apply Qdisc offloading (HTB or ETS) for traffic to
and from GDM{3,4} port.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

drivers/net/ethernet/airoha/airoha_eth.c

@@ -1588,14 +1588,81 @@ static int airoha_dev_set_macaddr(struct net_device *dev, void *p)
 	return 0;
 }
 
+static void airhoha_set_gdm2_loopback(struct airoha_gdm_port *port)
+{
+	u32 pse_port = port->id == 3 ? FE_PSE_PORT_GDM3 : FE_PSE_PORT_GDM4;
+	struct airoha_eth *eth = port->qdma->eth;
+	u32 chan = port->id == 3 ? 4 : 0;
+
+	/* Forward the traffic to the proper GDM port */
+	airoha_set_gdm_port_fwd_cfg(eth, REG_GDM_FWD_CFG(2), pse_port);
+	airoha_fe_clear(eth, REG_GDM_FWD_CFG(2), GDM_STRIP_CRC);
+
+	/* Enable GDM2 loopback */
+	airoha_fe_wr(eth, REG_GDM_TXCHN_EN(2), 0xffffffff);
+	airoha_fe_wr(eth, REG_GDM_RXCHN_EN(2), 0xffff);
+	airoha_fe_rmw(eth, REG_GDM_LPBK_CFG(2),
+		      LPBK_CHAN_MASK | LPBK_MODE_MASK | LPBK_EN_MASK,
+		      FIELD_PREP(LPBK_CHAN_MASK, chan) | LPBK_EN_MASK);
+	airoha_fe_rmw(eth, REG_GDM_LEN_CFG(2),
+		      GDM_SHORT_LEN_MASK | GDM_LONG_LEN_MASK,
+		      FIELD_PREP(GDM_SHORT_LEN_MASK, 60) |
+		      FIELD_PREP(GDM_LONG_LEN_MASK, AIROHA_MAX_MTU));
+
+	/* Disable VIP and IFC for GDM2 */
+	airoha_fe_clear(eth, REG_FE_VIP_PORT_EN, BIT(2));
+	airoha_fe_clear(eth, REG_FE_IFC_PORT_EN, BIT(2));
+
+	if (port->id == 3) {
+		/* FIXME: handle XSI_PCE1_PORT */
+		airoha_fe_wr(eth, REG_PPE_DFT_CPORT0(0),  0x5500);
+		airoha_fe_rmw(eth, REG_FE_WAN_PORT,
+			      WAN1_EN_MASK | WAN1_MASK | WAN0_MASK,
+			      FIELD_PREP(WAN0_MASK, HSGMII_LAN_PCIE0_SRCPORT));
+		airoha_fe_rmw(eth,
+			      REG_SP_DFT_CPORT(HSGMII_LAN_PCIE0_SRCPORT >> 3),
+			      SP_CPORT_PCIE0_MASK,
+			      FIELD_PREP(SP_CPORT_PCIE0_MASK,
+					 FE_PSE_PORT_CDM2));
+	} else {
+		/* FIXME: handle XSI_USB_PORT */
+		airoha_fe_rmw(eth, REG_SRC_PORT_FC_MAP6,
+			      FC_ID_OF_SRC_PORT24_MASK,
+			      FIELD_PREP(FC_ID_OF_SRC_PORT24_MASK, 2));
+		airoha_fe_rmw(eth, REG_FE_WAN_PORT,
+			      WAN1_EN_MASK | WAN1_MASK | WAN0_MASK,
+			      FIELD_PREP(WAN0_MASK, HSGMII_LAN_ETH_SRCPORT));
+		airoha_fe_rmw(eth,
+			      REG_SP_DFT_CPORT(HSGMII_LAN_ETH_SRCPORT >> 3),
+			      SP_CPORT_ETH_MASK,
+			      FIELD_PREP(SP_CPORT_ETH_MASK, FE_PSE_PORT_CDM2));
+	}
+}
+
 static int airoha_dev_init(struct net_device *dev)
 {
 	struct airoha_gdm_port *port = netdev_priv(dev);
 	struct airoha_eth *eth = port->qdma->eth;
+	u32 pse_port;
 
 	airoha_set_macaddr(port, dev->dev_addr);
-	airoha_set_gdm_port_fwd_cfg(eth, REG_GDM_FWD_CFG(port->id),
-				    FE_PSE_PORT_PPE1);
+
+	switch (port->id) {
+	case 3:
+	case 4:
+		/* If GDM2 is active we can't enable loopback */
+		if (!eth->ports[1])
+			airhoha_set_gdm2_loopback(port);
+		fallthrough;
+	case 2:
+		pse_port = FE_PSE_PORT_PPE2;
+		break;
+	default:
+		pse_port = FE_PSE_PORT_PPE1;
+		break;
+	}
+
+	airoha_set_gdm_port_fwd_cfg(eth, REG_GDM_FWD_CFG(port->id), pse_port);
 
 	return 0;
 }

drivers/net/ethernet/airoha/airoha_eth.h

@@ -67,6 +67,13 @@ enum {
 	QDMA_INT_REG_MAX
 };
 
+enum {
+	HSGMII_LAN_PCIE0_SRCPORT = 0x16,
+	HSGMII_LAN_PCIE1_SRCPORT,
+	HSGMII_LAN_ETH_SRCPORT,
+	HSGMII_LAN_USB_SRCPORT,
+};
+
 enum {
 	XSI_PCIE0_VIP_PORT_MASK	= BIT(22),
 	XSI_PCIE1_VIP_PORT_MASK	= BIT(23),

drivers/net/ethernet/airoha/airoha_ppe.c

@@ -216,22 +216,22 @@ static int airoha_ppe_foe_entry_prepare(struct airoha_foe_entry *hwe,
 	      AIROHA_FOE_IB1_BIND_TTL;
 	hwe->ib1 = val;
 
-	val = FIELD_PREP(AIROHA_FOE_IB2_PORT_AG, 0x1f);
+	val = FIELD_PREP(AIROHA_FOE_IB2_PORT_AG, 0x1f) |
+	      AIROHA_FOE_IB2_PSE_QOS;
 	if (dsa_port >= 0)
 		val |= FIELD_PREP(AIROHA_FOE_IB2_NBQ, dsa_port);
 
 	if (dev) {
 		struct airoha_gdm_port *port = netdev_priv(dev);
 		u8 pse_port;
 
-		pse_port = port->id == 4 ? FE_PSE_PORT_GDM4 : port->id;
+		if (dsa_port >= 0)
+			pse_port = port->id == 4 ? FE_PSE_PORT_GDM4 : port->id;
+		else
+			pse_port = 2; /* uplink relies on GDM2 loopback */
 		val |= FIELD_PREP(AIROHA_FOE_IB2_PSE_PORT, pse_port);
 	}
 
-	/* FIXME: implement QoS support setting pse_port to 2 (loopback)
-	 * for uplink and setting qos bit in ib2
-	 */
-
 	if (is_multicast_ether_addr(data->eth.h_dest))
 		val |= AIROHA_FOE_IB2_MULTICAST;
 

drivers/net/ethernet/airoha/airoha_regs.h

@@ -38,6 +38,12 @@
 #define FE_RST_CORE_MASK		BIT(0)
 
 #define REG_FE_FOE_TS			0x0010
+
+#define REG_FE_WAN_PORT			0x0024
+#define WAN1_EN_MASK			BIT(16)
+#define WAN1_MASK			GENMASK(12, 8)
+#define WAN0_MASK			GENMASK(4, 0)
+
 #define REG_FE_WAN_MAC_H		0x0030
 #define REG_FE_LAN_MAC_H		0x0040
 
@@ -126,6 +132,7 @@
 #define GDM_IP4_CKSUM			BIT(22)
 #define GDM_TCP_CKSUM			BIT(21)
 #define GDM_UDP_CKSUM			BIT(20)
+#define GDM_STRIP_CRC			BIT(16)
 #define GDM_UCFQ_MASK			GENMASK(15, 12)
 #define GDM_BCFQ_MASK			GENMASK(11, 8)
 #define GDM_MCFQ_MASK			GENMASK(7, 4)
@@ -139,6 +146,16 @@
 #define GDM_SHORT_LEN_MASK		GENMASK(13, 0)
 #define GDM_LONG_LEN_MASK		GENMASK(29, 16)
 
+#define REG_GDM_LPBK_CFG(_n)		(GDM_BASE(_n) + 0x1c)
+#define LPBK_GAP_MASK			GENMASK(31, 24)
+#define LPBK_LEN_MASK			GENMASK(23, 10)
+#define LPBK_CHAN_MASK			GENMASK(8, 4)
+#define LPBK_MODE_MASK			GENMASK(3, 1)
+#define LPBK_EN_MASK			BIT(0)
+
+#define REG_GDM_TXCHN_EN(_n)		(GDM_BASE(_n) + 0x24)
+#define REG_GDM_RXCHN_EN(_n)		(GDM_BASE(_n) + 0x28)
+
 #define REG_FE_CPORT_CFG		(GDM1_BASE + 0x40)
 #define FE_CPORT_PAD			BIT(26)
 #define FE_CPORT_PORT_XFC_MASK		BIT(25)
@@ -351,6 +368,18 @@
 
 #define REG_MC_VLAN_DATA		0x2108
 
+#define REG_SP_DFT_CPORT(_n)		(0x20e0 + ((_n) << 2))
+#define SP_CPORT_PCIE1_MASK		GENMASK(31, 28)
+#define SP_CPORT_PCIE0_MASK		GENMASK(27, 24)
+#define SP_CPORT_USB_MASK		GENMASK(7, 4)
+#define SP_CPORT_ETH_MASK		GENMASK(7, 4)
+
+#define REG_SRC_PORT_FC_MAP6		0x2298
+#define FC_ID_OF_SRC_PORT27_MASK	GENMASK(28, 24)
+#define FC_ID_OF_SRC_PORT26_MASK	GENMASK(20, 16)
+#define FC_ID_OF_SRC_PORT25_MASK	GENMASK(12, 8)
+#define FC_ID_OF_SRC_PORT24_MASK	GENMASK(4, 0)
+
 #define REG_CDM5_RX_OQ1_DROP_CNT	0x29d4
 
 /* QDMA */