Re: [RFC net-next 1/6] ethernet: add a helper for assigning port addresses

On Fri, Oct 15, 2021 at 12:38:43PM -0700, Jakub Kicinski wrote:

+/**
+ * eth_hw_addr_set_port - Generate and assign Ethernet address to a port
+ * @dev: pointer to port's net_device structure
+ * @base_addr: base Ethernet address
+ * @id: offset to add to the base address
+ *
+ * Assign a MAC address to the net_device using a base address and an offset.
+ * Commonly used by switch drivers which need to compute addresses for all
+ * their ports. addr_assign_type is not changed.
+ */
+static inline void eth_hw_addr_set_port(struct net_device *dev,
+					const u8 *base_addr, u8 id)

If necessary, would it be possible to change 'id' to u16?

I'm asking because currently in mlxsw we set the MAC of each netdev to
'base_mac + local_port' where 'local_port' is u8. In Spectrum-4 we are
going to have more than 256 logical ports, so 'local_port' becomes u16.

Regarding the naming, eth_hw_addr_gen() sounds good to me.

Thanks for working on this

+{
+	u64 u = ether_addr_to_u64(base_addr);
+	u8 addr[ETH_ALEN];
+
+	u += id;
+	u64_to_ether_addr(u, addr);
+	eth_hw_addr_set(dev, addr);
+}
+
 /**
  * eth_skb_pad - Pad buffer to mininum number of octets for Ethernet frame
  * @skb: Buffer to pad
-- 
2.31.1