This is a respin of https://www.spinics.net/lists/netdev/msg526066.html Since page_pool API fixes are merged into net-next we can now safely use it's DMA mapping capabilities.
The first patch changes the buffer allocation from netdev_alloc_frag() to page_pool API. Although this will lead to slightly reduced performance (on raw packet drops only) we can use the API for XDP buffer recycling. Another side effect is a slight increase in memory usage, due to using a single page per packet. The second patch adds XDP support on the driver. There's a bunch of interesting options that come up due to the single Tx queue. Use of locking (to avoid messing up the Tx queue since ndo_xdp_xmit and the normal stack can co-exist) is one thing. We also need to track down the 'buffer type' for TX and properly free or recycle the packet depending on it's nature. Since we use page_pool API in the XDP_TX case the buffers are already mapped for us and we only need to sync them, while on the ndo_xdp_xmit we need to map and send them Ilias Apalodimas (2): net: netsec: Use page_pool API net: netsec: add XDP support drivers/net/ethernet/socionext/Kconfig | 1 + drivers/net/ethernet/socionext/netsec.c | 459 ++++++++++++++++++++---- 2 files changed, 394 insertions(+), 66 deletions(-) -- 2.20.1
