Re: [PATCH net-next v10 00/10] net: intel: start The Great Code Dedup + Page Pool for iavf

From: Przemek Kitszel
Date: Thu Apr 18 2024 - 10:32:19 EST


On 4/18/24 13:36, Alexander Lobakin wrote:
Here's a two-shot: introduce {,Intel} Ethernet common library (libeth and
libie) and switch iavf to Page Pool. Details are in the commit messages;
here's a 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 name that came to my mind was
"libie" -- "Intel Ethernet common library". Also this sounds like
"lovelie" (-> one word, no "lib I E" pls) and can be expanded as
"lib Internet Explorer" :P
The "generic", pure-software part is placed separately, so that it can be
easily reused in any driver by any vendor without linking to the Intel
pre-200G guts. In a few words, it's something any modern driver does the
same way, but nobody moved it level up (yet).
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?". The final destination is very ambitious: have only
one unified driver for at least i40e, ice, iavf, and idpf with a struct
ops for each generation. That's never gonna happen, right? But you still
can at least try.
PP conversion for iavf lands within the same series as these two are tied
closely. libie will support Page Pool model only, so that 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 (10):
net: intel: introduce {,Intel} Ethernet common library
iavf: kill "legacy-rx" for good
iavf: drop page splitting and recycling
slab: introduce kvmalloc_array_node() and kvcalloc_node()
page_pool: constify some read-only function arguments
page_pool: add DMA-sync-for-CPU inline helper
libeth: add Rx buffer management
iavf: pack iavf_ring more efficiently
iavf: switch to Page Pool
MAINTAINERS: add entry for libeth and libie

MAINTAINERS | 20 +
drivers/net/ethernet/intel/Kconfig | 7 +
drivers/net/ethernet/intel/libeth/Kconfig | 9 +
drivers/net/ethernet/intel/libie/Kconfig | 10 +
drivers/net/ethernet/intel/Makefile | 3 +
drivers/net/ethernet/intel/libeth/Makefile | 6 +
drivers/net/ethernet/intel/libie/Makefile | 6 +
include/net/page_pool/types.h | 4 +-
.../net/ethernet/intel/i40e/i40e_prototype.h | 7 -
drivers/net/ethernet/intel/i40e/i40e_type.h | 88 ---
drivers/net/ethernet/intel/iavf/iavf.h | 2 +-
.../net/ethernet/intel/iavf/iavf_prototype.h | 7 -
drivers/net/ethernet/intel/iavf/iavf_txrx.h | 146 +----
drivers/net/ethernet/intel/iavf/iavf_type.h | 90 ---
.../net/ethernet/intel/ice/ice_lan_tx_rx.h | 320 ----------
include/linux/net/intel/libie/rx.h | 50 ++
include/linux/slab.h | 17 +-
include/net/libeth/rx.h | 242 ++++++++
include/net/page_pool/helpers.h | 34 +-
drivers/net/ethernet/intel/i40e/i40e_common.c | 253 --------
drivers/net/ethernet/intel/i40e/i40e_main.c | 1 +
drivers/net/ethernet/intel/i40e/i40e_txrx.c | 72 +--
drivers/net/ethernet/intel/iavf/iavf_common.c | 253 --------
.../net/ethernet/intel/iavf/iavf_ethtool.c | 140 -----
drivers/net/ethernet/intel/iavf/iavf_main.c | 40 +-
drivers/net/ethernet/intel/iavf/iavf_txrx.c | 551 +++---------------
.../net/ethernet/intel/iavf/iavf_virtchnl.c | 17 +-
drivers/net/ethernet/intel/ice/ice_main.c | 1 +
drivers/net/ethernet/intel/ice/ice_txrx_lib.c | 111 +---
drivers/net/ethernet/intel/libeth/rx.c | 150 +++++
drivers/net/ethernet/intel/libie/rx.c | 124 ++++
net/core/page_pool.c | 10 +-
32 files changed, 836 insertions(+), 1955 deletions(-)
create mode 100644 drivers/net/ethernet/intel/libeth/Kconfig
create mode 100644 drivers/net/ethernet/intel/libie/Kconfig
create mode 100644 drivers/net/ethernet/intel/libeth/Makefile
create mode 100644 drivers/net/ethernet/intel/libie/Makefile
create mode 100644 include/linux/net/intel/libie/rx.h
create mode 100644 include/net/libeth/rx.h
create mode 100644 drivers/net/ethernet/intel/libeth/rx.c
create mode 100644 drivers/net/ethernet/intel/libie/rx.c

---
libeth has way more generic functionality and code in the idpf XDP
tree[0], take a look if you want to have more complete picture of
what this really is about.

From v9[1]:
* pick Acked-by from Vlastimil and a couple Reviewed-by from Przemek;

thanks for the updates too!
I've read the code ~two times across the life of this series, nothing
bad spot, so for the series:
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@xxxxxxxxx>

* mention that the libeth_fq::fp kernel-doc generates a warning and the
fix for that is pending on the linux-doc ML (Jakub);
* no functional changes.

// ...