[PATCH v7 net-next 0/4] add multi-buff support for xdp running in generic mode

[Lorenzo Bianconi <lorenzo@kernel.org>]

Introduce multi-buffer support for xdp running in generic mode not always
linearizing the skb in netif_receive_generic_xdp routine.
Introduce generic percpu page_pools allocator.

Changes since v6:
- remove patch 4/5 'net: page_pool: make stats available just for global pools'
- rename netif_skb_segment_for_xdp() in
  skb_cow_data_for_xdp()/skb_pp_cow_data()
- rename net_page_pool_alloc() in net_page_pool_create()
- rename page_pool percpu pointer in system_page_pool
- set percpu page_pool memory size
Changes since v5:
- move percpu page_pool pointer out of softnet_data in a dedicated variable
- make page_pool stats available just for global pools
- rely on netif_skb_segment_for_xdp utility routine in veth driver
Changes since v4:
- fix compilation error if page_pools are not enabled
Changes since v3:
- introduce page_pool in softnet_data structure
- rely on page_pools for xdp_generic code
Changes since v2:
- rely on napi_alloc_frag() and napi_build_skb() to build the new skb
Changes since v1:
- explicitly keep the skb segmented in netif_skb_check_for_generic_xdp() and
  do not rely on pskb_expand_head()

Lorenzo Bianconi (4):
  net: add generic percpu page_pool allocator
  xdp: rely on skb pointer reference in do_xdp_generic and
    netif_receive_generic_xdp
  xdp: add multi-buff support for xdp running in generic mode
  veth: rely on skb_cow_data_for_xdp utility routine

 drivers/net/tun.c             |   4 +-
 drivers/net/veth.c            |  79 ++------------------
 include/linux/netdevice.h     |   2 +-
 include/linux/skbuff.h        |   2 +
 include/net/page_pool/types.h |   3 +
 net/core/dev.c                | 131 +++++++++++++++++++++++++++-------
 net/core/page_pool.c          |  23 ++++--
 net/core/skbuff.c             |  96 ++++++++++++++++++++++++-
 8 files changed, 231 insertions(+), 109 deletions(-)

-- 
2.43.0