Merge branch 'eth_hw_addr_gen-for-switches'

Jakub Kicinski says:

====================
ethernet: add eth_hw_addr_gen() for switches

While doing the last polishing of the drivers/ethernet
changes I realized we have a handful of drivers offsetting
some base MAC addr by an id. So I decided to add a helper
for it. The helper takes care of wrapping which is probably
not 100% necessary but seems like a good idea. And it saves
driver side LoC (the diffstat is actually negative if we
compare against the changes I'd have to make if I was to
convert all these drivers to not operate directly on
netdev->dev_addr).
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 21 insertions, 0 deletions

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
@@ -552,6 +552,27 @@ static inline unsigned long compare_ether_header(const void *a, const void *b)
 }
 
 /**
+ * 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
  *