From 286ab723d4b83d37deb4017008ef1444a95cfb0d Mon Sep 17 00:00:00 2001 From: Joe Perches Date: Tue, 14 Jan 2014 15:18:47 -0800 Subject: [PATCH] etherdevice: Use ether_addr_copy to copy an Ethernet address Some systems can use the normally known u16 alignment of Ethernet addresses to save some code/text bytes and cycles. This does not change currently emitted code on x86 by gcc 4.8. Signed-off-by: Joe Perches Signed-off-by: David S. Miller --- include/linux/etherdevice.h | 24 +++++++++++++++++++++++- 1 file changed, 23 insertions(+), 1 deletion(-) diff --git a/include/linux/etherdevice.h b/include/linux/etherdevice.h index f344ac04f85..9c5529dc6d0 100644 --- a/include/linux/etherdevice.h +++ b/include/linux/etherdevice.h @@ -217,6 +217,28 @@ static inline void eth_hw_addr_random(struct net_device *dev) eth_random_addr(dev->dev_addr); } +/** + * ether_addr_copy - Copy an Ethernet address + * @dst: Pointer to a six-byte array Ethernet address destination + * @src: Pointer to a six-byte array Ethernet address source + * + * Please note: dst & src must both be aligned to u16. + */ +static inline void ether_addr_copy(u8 *dst, const u8 *src) +{ +#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) + *(u32 *)dst = *(const u32 *)src; + *(u16 *)(dst + 4) = *(const u16 *)(src + 4); +#else + u16 *a = (u16 *)dst; + const u16 *b = (const u16 *)src; + + a[0] = b[0]; + a[1] = b[1]; + a[2] = b[2]; +#endif +} + /** * eth_hw_addr_inherit - Copy dev_addr from another net_device * @dst: pointer to net_device to copy dev_addr to @@ -229,7 +251,7 @@ static inline void eth_hw_addr_inherit(struct net_device *dst, struct net_device *src) { dst->addr_assign_type = src->addr_assign_type; - memcpy(dst->dev_addr, src->dev_addr, ETH_ALEN); + ether_addr_copy(dst->dev_addr, src->dev_addr); } /** -- 2.43.2