net: stmmac: ARP Offload for GMAC4+ Cores

Implement the ARP Offload feature in GMAC4 and GMAC5 cores.
Signed-off-by: Jose Abreu <joabreu@synopsys.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/stmicro/stmmac/dwmac4.h

@@ -40,6 +40,7 @@
 #define GMAC_HW_FEATURE3		0x00000128
 #define GMAC_MDIO_ADDR			0x00000200
 #define GMAC_MDIO_DATA			0x00000204
+#define GMAC_ARP_ADDR			0x00000210
 #define GMAC_ADDR_HIGH(reg)		(0x300 + reg * 8)
 #define GMAC_ADDR_LOW(reg)		(0x304 + reg * 8)
 
@@ -165,6 +166,7 @@ enum power_event {
 #define GMAC_DEBUG_RPESTS		BIT(0)
 
 /* MAC config */
+#define GMAC_CONFIG_ARPEN		BIT(31)
 #define GMAC_CONFIG_SARC		GENMASK(30, 28)
 #define GMAC_CONFIG_SARC_SHIFT		28
 #define GMAC_CONFIG_IPC			BIT(27)
@@ -188,6 +190,7 @@ enum power_event {
 #define GMAC_HW_FEAT_TXCOSEL		BIT(14)
 #define GMAC_HW_FEAT_EEESEL		BIT(13)
 #define GMAC_HW_FEAT_TSSEL		BIT(12)
+#define GMAC_HW_FEAT_ARPOFFSEL		BIT(9)
 #define GMAC_HW_FEAT_MMCSEL		BIT(8)
 #define GMAC_HW_FEAT_MGKSEL		BIT(7)
 #define GMAC_HW_FEAT_RWKSEL		BIT(6)

drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c

@@ -782,6 +782,22 @@ static void dwmac4_enable_vlan(struct mac_device_info *hw, u32 type)
 	writel(value, ioaddr + GMAC_VLAN_INCL);
 }
 
+static void dwmac4_set_arp_offload(struct mac_device_info *hw, bool en,
+				   u32 addr)
+{
+	void __iomem *ioaddr = hw->pcsr;
+	u32 value;
+
+	writel(addr, ioaddr + GMAC_ARP_ADDR);
+
+	value = readl(ioaddr + GMAC_CONFIG);
+	if (en)
+		value |= GMAC_CONFIG_ARPEN;
+	else
+		value &= ~GMAC_CONFIG_ARPEN;
+	writel(value, ioaddr + GMAC_CONFIG);
+}
+
 const struct stmmac_ops dwmac4_ops = {
 	.core_init = dwmac4_core_init,
 	.set_mac = stmmac_set_mac,
@@ -815,6 +831,7 @@ const struct stmmac_ops dwmac4_ops = {
 	.update_vlan_hash = dwmac4_update_vlan_hash,
 	.sarc_configure = dwmac4_sarc_configure,
 	.enable_vlan = dwmac4_enable_vlan,
+	.set_arp_offload = dwmac4_set_arp_offload,
 };
 
 const struct stmmac_ops dwmac410_ops = {
@@ -850,6 +867,7 @@ const struct stmmac_ops dwmac410_ops = {
 	.update_vlan_hash = dwmac4_update_vlan_hash,
 	.sarc_configure = dwmac4_sarc_configure,
 	.enable_vlan = dwmac4_enable_vlan,
+	.set_arp_offload = dwmac4_set_arp_offload,
 };
 
 const struct stmmac_ops dwmac510_ops = {
@@ -890,6 +908,7 @@ const struct stmmac_ops dwmac510_ops = {
 	.update_vlan_hash = dwmac4_update_vlan_hash,
 	.sarc_configure = dwmac4_sarc_configure,
 	.enable_vlan = dwmac4_enable_vlan,
+	.set_arp_offload = dwmac4_set_arp_offload,
 };
 
 int dwmac4_setup(struct stmmac_priv *priv)

drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c

@@ -349,6 +349,7 @@ static void dwmac4_get_hw_feature(void __iomem *ioaddr,
 	dma_cap->tx_coe = (hw_cap & GMAC_HW_FEAT_TXCOSEL) >> 14;
 	dma_cap->rx_coe =  (hw_cap & GMAC_HW_FEAT_RXCOESEL) >> 16;
 	dma_cap->vlins = (hw_cap & GMAC_HW_FEAT_SAVLANINS) >> 27;
+	dma_cap->arpoffsel = (hw_cap & GMAC_HW_FEAT_ARPOFFSEL) >> 9;
 
 	/* MAC HW feature1 */
 	hw_cap = readl(ioaddr + GMAC_HW_FEATURE1);