net/mlx4_en: add support for fast rx drop bpf program
authorBrenden Blanco <bblanco@plumgrid.com>
Tue, 19 Jul 2016 19:16:50 +0000 (12:16 -0700)
committerDavid S. Miller <davem@davemloft.net>
Wed, 20 Jul 2016 04:46:32 +0000 (21:46 -0700)
commit47a38e155037f417c5740e24ccae6482aedf4b68
treec615b0df2ff096b528d723dc2aa029172fc31ac3
parentd1fdd9138682e0f272beee0cb08b6328c5478b26
net/mlx4_en: add support for fast rx drop bpf program

Add support for the BPF_PROG_TYPE_XDP hook in mlx4 driver.

In tc/socket bpf programs, helpers linearize skb fragments as needed
when the program touches the packet data. However, in the pursuit of
speed, XDP programs will not be allowed to use these slower functions,
especially if it involves allocating an skb.

Therefore, disallow MTU settings that would produce a multi-fragment
packet that XDP programs would fail to access. Future enhancements could
be done to increase the allowable MTU.

The xdp program is present as a per-ring data structure, but as of yet
it is not possible to set at that granularity through any ndo.

Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/net/ethernet/mellanox/mlx4/en_netdev.c
drivers/net/ethernet/mellanox/mlx4/en_rx.c
drivers/net/ethernet/mellanox/mlx4/mlx4_en.h