Merge branch 'xdp-redirect-bulk'

Lorenzo Bianconi says:

====================
XDP bulk APIs introduce a defer/flush mechanism to return
pages belonging to the same xdp_mem_allocator object
(identified via the mem.id field) in bulk to optimize
I-cache and D-cache since xdp_return_frame is usually
run inside the driver NAPI tx completion loop.

Convert mvneta, mvpp2 and mlx5 drivers to xdp_return_frame_bulk APIs.

More details on benchmarks run on mlx5 can be found here:
https://github.com/xdp-project/xdp-project/blob/master/areas/mem/xdp_bulk_return01.org



Changes since v5:
- do not keep looping over ptr_ring if the cache is full but release leftover
  pages running page_pool_return_page

Changes since v4:
- fix comments
- introduce xdp_frame_bulk_init utility routine
- compiler annotations for I-cache code layout
- move rcu_read_lock outside fast-path
- mlx5 xdp bulking code optimization

Changes since v3:
- align DEV_MAP_BULK_SIZE to XDP_BULK_QUEUE_SIZE
- refactor page_pool_put_page_bulk to avoid code duplication

Changes since v2:
- move mvneta changes in a dedicated patch

Changes since v1:
- improve comments
- rework xdp_return_frame_bulk routine logic
- move count and xa fields at the beginning of xdp_frame_bulk struct
- invert logic in page_pool_put_page_bulk for loop
====================

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>