Merge branch 'dpaa_eth-a050385-erratum-workaround-fixes-under-xdp'

Merge branch 'dpaa_eth-a050385-erratum-workaround-fixes-under-xdp'

Camelia Groza says:

====================
dpaa_eth: A050385 erratum workaround fixes under XDP

This series addresses issue with the current workaround for the A050385
erratum in XDP scenarios.

The first patch makes sure the xdp_frame structure stored at the start of
new buffers isn't overwritten.

The second patch decreases the required data alignment value, thus
preventing unnecessary realignments.

The third patch moves the data in place to align it, instead of allocating
a new buffer for each frame that breaks the alignment rules, thus bringing
an up to 40% performance increase. With this change, the impact of the
erratum workaround is reduced in many cases to a single digit decrease, and
to lower double digits in single flow scenarios.

Changes in v2:
- guarantee enough tailroom is available for the shared_info in 1/3
====================

Link: https://lore.kernel.org/r/cover.1612456902.git.camelia.groza@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>