Merge branch '40GbE' of git://git.kernel.org/pub/scm/linux/kernel/git/tnguy/next...

Merge branch '40GbE' of git://git./linux/kernel/git/tnguy/next-queue

Tony Nguyen says:

====================
i40e: support XDP multi-buffer

Tirthendu Sarkar says:

This patchset adds multi-buffer support for XDP. Tx side already has
support for multi-buffer. This patchset focuses on Rx side. The last
patch contains actual multi-buffer changes while the previous ones are
preparatory patches.

On receiving the first buffer of a packet, xdp_buff is built and its
subsequent buffers are added to it as frags. While 'next_to_clean' keeps
pointing to the first descriptor, the newly introduced 'next_to_process'
keeps track of every descriptor for the packet.

On receiving EOP buffer the XDP program is called and appropriate action
is taken (building skb for XDP_PASS, reusing page for XDP_DROP, adjusting
page offsets for XDP_{REDIRECT,TX}).

The patchset also streamlines page offset adjustments for buffer reuse
to make it easier to post process the rx_buffers after running XDP prog.

With this patchset there does not seem to be any performance degradation
for XDP_PASS and some improvement (~1% for XDP_TX, ~5% for XDP_DROP) when
measured using xdp_rxq_info program from samples/bpf/ for 64B packets.

v1: https://lore.kernel.org/netdev/20230306210822.3381942-1-anthony.l.nguyen@intel.com/

* '40GbE' of git://git.kernel.org/pub/scm/linux/kernel/git/tnguy/next-queue:
  i40e: add support for XDP multi-buffer Rx
  i40e: add xdp_buff to i40e_ring struct
  i40e: introduce next_to_process to i40e_ring
  i40e: use frame_sz instead of recalculating truesize for building skb
  i40e: Change size to truesize when using i40e_rx_buffer_flip()
  i40e: add pre-xdp page_count in rx_buffer
  i40e: change Rx buffer size for legacy-rx to support XDP multi-buffer
  i40e: consolidate maximum frame size calculation for vsi
====================

Link: https://lore.kernel.org/r/20230309212819.1198218-1-anthony.l.nguyen@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>