[net-next,v4,0/5] net: ipqess: introduce Qualcomm IPQESS driver

Hello everyone,

This is the 4th iteration of a series that introduces a new driver, for
the Qualcomm IPQESS Ethernet Controller, found on the IPQ4019.

Note that this series contains binding patches that should go through the
DT tree.

The DSA out-of-band tagging is still using the skb->headroom part, but
there doesn't seem to be any better way for now without adding fields to
struct sk_buff.

Notables changes on V4 :
 - Cache the uses_dsa info from CHANGEUPPER events
 - Use better string handling helpers for ethtool stats
 - rename ethtool callbacks
 - Fix a binding typo

Notables changes on V3 :
 - Took into account Russell's review on the ioctl handler and the mac
   capabilities that were missing
 - Took Andrew's reviews into account by reworking the napi rx loop,
   some stray "inline" keywords, and useless warnings
 - Took Vlad's reviews into account by reworking a few macros
 - Took Christophe's review into account by removing extra GFP_ZERO
 - Took Rob's review into account by simplifying the binding

Note that this V3 didn't focus on the tagging protocol, as I understand
the issue is still open. I'm willing to keep on testing some ideas, and
continue Florian's discussion.

Notables changes on V2 :
 - Put the DSA tag in the skb itself instead of using skb->shinfo
 - Fixed the initialisation sequence based on Andrew's comments
 - Reworked the error paths in the init sequence
 - Add support for the clock and reset lines on that controller
 - Fixed and updated the binding

The driver itself is pretty straightforward, but has lived out-of-tree
for a while. I've done my best to clean-up some outdated API calls, but
some might remain.

This controller is somewhat special, since it's part of the IPQ4019 SoC
which also includes an QCA8K switch, and uses the IPQESS controller for
the CPU port. The switch is so tightly intergrated with the MAC that it
is connected to the MAC using an internal link (hence the fact that we
only support PHY_INTERFACE_MODE_INTERNAL), and this has some
consequences on the DSA side.

The tagging for the switch isn't done inband as most switch do, but
out-of-band, the DSA tag being included in the DMA descriptor.

This series includes a new out-of-band tagger that uses the skb headroom
to convey the tag between the tagger and the MAC driver.

Thanks to the Sartura folks who worked on a base version of this driver,
and provided test hardware.

Best regards,

Maxime Chevallier



Maxime Chevallier (5):
  net: ipqess: introduce the Qualcomm IPQESS driver
  net: dsa: add out-of-band tagging protocol
  net: ipqess: Add out-of-band DSA tagging support
  net: dt-bindings: Introduce the Qualcomm IPQESS Ethernet controller
  ARM: dts: qcom: ipq4019: Add description for the IPQESS Ethernet
    controller

 .../devicetree/bindings/net/qcom,ipqess.yaml  |   95 ++
 MAINTAINERS                                   |    6 +
 arch/arm/boot/dts/qcom-ipq4019.dtsi           |   46 +
 drivers/net/ethernet/qualcomm/Kconfig         |   12 +
 drivers/net/ethernet/qualcomm/Makefile        |    2 +
 drivers/net/ethernet/qualcomm/ipqess/Makefile |    8 +
 drivers/net/ethernet/qualcomm/ipqess/ipqess.c | 1310 +++++++++++++++++
 drivers/net/ethernet/qualcomm/ipqess/ipqess.h |  522 +++++++
 .../ethernet/qualcomm/ipqess/ipqess_ethtool.c |  164 +++
 include/linux/dsa/oob.h                       |   17 +
 include/net/dsa.h                             |    2 +
 net/dsa/Kconfig                               |    7 +
 net/dsa/Makefile                              |    1 +
 net/dsa/tag_oob.c                             |   84 ++
 14 files changed, 2276 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/net/qcom,ipqess.yaml
 create mode 100644 drivers/net/ethernet/qualcomm/ipqess/Makefile
 create mode 100644 drivers/net/ethernet/qualcomm/ipqess/ipqess.c
 create mode 100644 drivers/net/ethernet/qualcomm/ipqess/ipqess.h
 create mode 100644 drivers/net/ethernet/qualcomm/ipqess/ipqess_ethtool.c
 create mode 100644 include/linux/dsa/oob.h
 create mode 100644 net/dsa/tag_oob.c

On Sat, 17 Sep 2022 00:20:31 +0000
Vladimir Oltean <vladimir.oltean@nxp.com> wrote:

> On Fri, Sep 09, 2022 at 05:24:49PM +0200, Maxime Chevallier wrote:
> > The DSA out-of-band tagging is still using the skb->headroom part,
> > but there doesn't seem to be any better way for now without adding
> > fields to struct sk_buff.  
> 
> Are we on the same page about what is meant by "skb extensions"? See
> what is provided by CONFIG_SKB_EXTENSIONS, I did not mean it as in
> "extend struct sk_buff with new fields".

Yep, that was one of the other approaches I had in mind, and I've
submitted a series adding fields to sk_buff in the past which was
rejected (for good reasons). But indeed that comment on the cover-letter
was misleading...

Thanks,

Maxime