[PATCH RFC net-next v4 0/9] net: intel: start The Great Code Dedup + Page Pool for iavf

[Alexander Lobakin <aleksander.lobakin@intel.com>]

Here's a two-shot: introduce Intel Ethernet common library (libie) and
switch iavf to Page Pool. Details in the commit messages; here's
summary:

Not a secret there's a ton of code duplication between two and more Intel
ethernet modules. Before introducing new changes, which would need to be
copied over again, start decoupling the already existing duplicate
functionality into a new module, which will be shared between several
Intel Ethernet drivers.
The first thing that came to my mind was "libie" -- "Intel Ethernet
common library". Also this sounds like "lovelie" and can be expanded as
"lib Internet Explorer" :P I'm open for anything else (but justified).
The series is only the beginning. From now on, adding every new feature
or doing any good driver refactoring will remove much more lines than add
for quite some time. There's a basic roadmap with some deduplications
planned already, not speaking of that touching every line now asks: "can
I share this?".
PP conversion for iavf lands within the same series as these two are tied
closely. libie will support Page Pool model only, so a driver can't use
much of the lib until it's converted. iavf is only the example, the rest
will eventually be converted soon on a per-driver basis. That is when it
gets really interesting. Stay tech.

Alexander Lobakin (9):
  net: intel: introduce Intel Ethernet common library
  iavf: kill "legacy-rx" for good
  iavf: drop page splitting and recycling
  net: page_pool: add DMA-sync-for-CPU inline helpers
  libie: add Rx buffer management (via Page Pool)
  iavf: switch to Page Pool
  libie: add common queue stats
  libie: add per-queue Page Pool stats
  iavf: switch queue stats to libie

 MAINTAINERS                                   |   3 +-
 drivers/net/ethernet/intel/Kconfig            |  11 +
 drivers/net/ethernet/intel/Makefile           |   1 +
 drivers/net/ethernet/intel/i40e/i40e_common.c | 253 --------
 drivers/net/ethernet/intel/i40e/i40e_main.c   |   1 +
 .../net/ethernet/intel/i40e/i40e_prototype.h  |   7 -
 drivers/net/ethernet/intel/i40e/i40e_txrx.c   |  74 +--
 drivers/net/ethernet/intel/i40e/i40e_type.h   |  88 ---
 drivers/net/ethernet/intel/iavf/iavf.h        |   2 +-
 drivers/net/ethernet/intel/iavf/iavf_common.c | 253 --------
 .../net/ethernet/intel/iavf/iavf_ethtool.c    | 226 +------
 drivers/net/ethernet/intel/iavf/iavf_main.c   |  44 +-
 .../net/ethernet/intel/iavf/iavf_prototype.h  |   7 -
 drivers/net/ethernet/intel/iavf/iavf_txrx.c   | 608 ++++--------------
 drivers/net/ethernet/intel/iavf/iavf_txrx.h   | 176 +----
 drivers/net/ethernet/intel/iavf/iavf_type.h   |  90 ---
 .../net/ethernet/intel/iavf/iavf_virtchnl.c   |  20 +-
 .../net/ethernet/intel/ice/ice_lan_tx_rx.h    | 316 ---------
 drivers/net/ethernet/intel/ice/ice_main.c     |   1 +
 drivers/net/ethernet/intel/ice/ice_txrx_lib.c |  74 +--
 drivers/net/ethernet/intel/libie/Makefile     |   7 +
 drivers/net/ethernet/intel/libie/internal.h   |  23 +
 drivers/net/ethernet/intel/libie/rx.c         | 183 ++++++
 drivers/net/ethernet/intel/libie/stats.c      | 190 ++++++
 include/linux/net/intel/libie/rx.h            | 241 +++++++
 include/linux/net/intel/libie/stats.h         | 214 ++++++
 include/net/page_pool.h                       |  49 +-
 27 files changed, 1137 insertions(+), 2025 deletions(-)
 create mode 100644 drivers/net/ethernet/intel/libie/Makefile
 create mode 100644 drivers/net/ethernet/intel/libie/internal.h
 create mode 100644 drivers/net/ethernet/intel/libie/rx.c
 create mode 100644 drivers/net/ethernet/intel/libie/stats.c
 create mode 100644 include/linux/net/intel/libie/rx.h
 create mode 100644 include/linux/net/intel/libie/stats.h

---
Directly to net-next, has non-Intel code change (#4) :p

Based on the PP "hybrid" allocation series[0] and requires it to work.

From v3[1]:
* base on the latest net-next, update bloat-o-meter and perf stats;
* split generic PP optimizations into a separate series;
* drop "optimize hotpath a bunch" commit: a lot of [controversial]
  changes in one place, worth own series (Alex);
* 02: pick Rev-by (Alex);
* 03: move in-place recycling removal here from the dropped patch;
* 05: new, add libie Rx buffer API separatelly from IAVF changes;
* 05-06: use new "hybrid" allocation API from[0] to reduce memory usage
  when a page can fit more than 1 truesize (also asked by David);
* 06: merge with "always use order-0 page" commit to reduce diffs and
  simplify things (Alex);
* 09: fix page_alloc_fail counter.

From v2[2]:
* 0006: fix page_pool.h include in OcteonTX2 files (Jakub, Patchwork);
* no functional changes.

From v1[3]:
* 0006: new (me, Jakub);
* 0008: give the helpers more intuitive names (Jakub, Ilias);
*  -^-: also expand their kdoc a bit for the same reason;
*  -^-: fix kdoc copy-paste issue (Patchwork, Jakub);
* 0011: drop `inline` from C file (Patchwork, Jakub).

[0] https://lore.kernel.org/netdev/20230629120226.14854-1-linyunsheng@huawei.com
[1] https://lore.kernel.org/netdev/20230530150035.1943669-1-aleksander.lobakin@intel.com
[2] https://lore.kernel.org/netdev/20230525125746.553874-1-aleksander.lobakin@intel.com
[3] https://lore.kernel.org/netdev/20230516161841.37138-1-aleksander.lobakin@intel.com

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2.41.0