From e80094a473eefad9d856ce3ab0d7afdbb64800c4 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Mon, 18 Oct 2021 14:10:02 -0700 Subject: ethernet: add a helper for assigning port addresses We have 5 drivers which offset base MAC addr by port id. Create a helper for them. This helper takes care of overflows, which some drivers did not do, please complain if that's going to break anything! Signed-off-by: Jakub Kicinski Reviewed-by: Vladimir Oltean Reviewed-by: Shannon Nelson Reviewed-by: Ido Schimmel Signed-off-by: David S. Miller --- include/linux/etherdevice.h | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/include/linux/etherdevice.h b/include/linux/etherdevice.h index 23681c3d3b8a..2ad71cc90b37 100644 --- a/include/linux/etherdevice.h +++ b/include/linux/etherdevice.h @@ -551,6 +551,27 @@ static inline unsigned long compare_ether_header(const void *a, const void *b) #endif } +/** + * eth_hw_addr_gen - 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 + * + * Generate a MAC address using a base address and an offset and assign it + * to a net_device. 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_gen(struct net_device *dev, const u8 *base_addr, + unsigned int id) +{ + 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 -- cgit