bgmac: implement scatter/gather support
bgmac: implement scatter/gather support

Always use software checksumming, since the hardware does not have any
checksum offload support.
This significantly improves local TCP tx performance.

Signed-off-by: Felix Fietkau <118ed6118e893d16e8c6e0776e0ebc290952c897@openwrt.org>
Signed-off-by: David S. Miller <fe08d3c717adf2ae63592e4c9aec6e3e404d8e3e@davemloft.net>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs