Re: [PATCH v3 net-next 09/10] net: dsa: microchip: add support for fdb and mdb management

On Fri, Jul 23, 2021 at 11:01:07PM +0530, Prasanna Vengateshan wrote:

+static int lan937x_port_fdb_add(struct dsa_switch *ds, int port,
+				const unsigned char *addr, u16 vid)
+{
+	struct ksz_device *dev = ds->priv;
+	u8 fid = lan937x_get_fid(vid);
+	u32 alu_table[4];
+	int ret, i;
+	u32 data;
+	u8 val;
+
+	mutex_lock(&dev->alu_mutex);
+
+	/* Accessing two ALU tables through loop */
+	for (i = 0; i < ALU_STA_DYN_CNT; i++) {
+		/* find any entry with mac & fid */
+		data = fid << ALU_FID_INDEX_S;
+		data |= ((addr[0] << 8) | addr[1]);

Maybe upper_32_bits(ether_addr_to_u64(addr)) and
lower_32_bits(ether_addr_to_u64(addr)) would be slightly easier on the
eye?

+		if (alu_table[0] & ALU_V_STATIC_VALID) {
+			/* read ALU entry */
+			ret = lan937x_read_table(dev, alu_table);
+			if (ret < 0) {
+				dev_err(dev->dev, "Failed to read ALU table\n");
+				break;
+			}
+
+			/* clear forwarding port */
+			alu_table[1] &= ~BIT(port);
+
+			/* if there is no port to forward, clear table */
+			if ((alu_table[1] & ALU_V_PORT_MAP) == 0) {
+				alu_table[0] = 0;
+				alu_table[1] = 0;
+				alu_table[2] = 0;
+				alu_table[3] = 0;

memset?

+			}
+		} else {
+			alu_table[0] = 0;
+			alu_table[1] = 0;
+			alu_table[2] = 0;
+			alu_table[3] = 0;
+		}
+
+		ret = lan937x_write_table(dev, alu_table);
+		if (ret < 0)
+			break;