netdev - Re: [PATCH net-next v2 1/2] dt-bindings: net: airoha: npu: Add EN7581-7996 support

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <aWoAnwF4JhMshN1H@lore-desk>
Date: Fri, 16 Jan 2026 10:10:55 +0100
From: Lorenzo Bianconi <lorenzo@...nel.org>
To: Andrew Lunn <andrew@...n.ch>
Cc: Christian Marangi <ansuelsmth@...il.com>,
	Krzysztof Kozlowski <krzk@...nel.org>,
	Andrew Lunn <andrew+netdev@...n.ch>,
	"David S. Miller" <davem@...emloft.net>,
	Eric Dumazet <edumazet@...gle.com>,
	Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>,
	Rob Herring <robh@...nel.org>,
	Krzysztof Kozlowski <krzk+dt@...nel.org>,
	Conor Dooley <conor+dt@...nel.org>, netdev@...r.kernel.org,
	devicetree@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
	linux-mediatek@...ts.infradead.org
Subject: Re: [PATCH net-next v2 1/2] dt-bindings: net: airoha: npu: Add
 EN7581-7996 support

> On Wed, Jan 14, 2026 at 11:35:10PM +0100, Lorenzo Bianconi wrote:
> > > > In the current codebase the NPU driver does not need to access the WiFi PCIe
> > > > slot (or any other external device) since the offloading (wired and wireless)
> > > > is fully managed by the NPU chip (hw + firmware binaries).
> > > 
> > > Are you saying the NPU itself enumerates the PCI busses and finds the
> > > WiFi device?  If it can do that, why not ask it which PCI device it is
> > > using?
> > 
> > nope, we do not need any PCI enumeration in the NPU driver at the moment
> > (please see below).
> > 
> > > 
> > > Or this the PCI slot to use somehow embedded within the firmware?
> > 
> > in the current implementation the NPU driver does not need any reference to
> > WiFi or Ethernet devices. The NPU exports offloading APIs to consumer devices
> > (e.g. WiFi or Ethernet devices). In particular,
> > 1- during NPU module probe, the NPU driver configures NPU hw registers and
> >    loads the NPU firmware binaries.
> > 2- NPU consumers (ethernet and/or wifi devices) get a reference to the NPU
> >    device via device-tree in order to consume NPU APIs for offloading.
> > 3- netfilter flowtable offloads traffic to the selected ethernet and/or WiFi
> >    device that runs the NPU APIs accessible via the NPU reference obtained via
> >    dts.
> > 
> > The issue here is the NPU firmware binaries for EN7581, loaded by the NPU
> > driver during NPU probe and used for offloading, depend on the WiFi chipset
> > (e.g. MT7996 or MT7992) available on the EN7581 board (we have two different
> > NPU binaries for MT7996 offloading and for MT7992 offloading).
> 
> Maybe i'm getting the NPU wrong, but i assumed it was directly talking
> to the Ethernet and WiFi device on the PCIe bus, bypassing the host?

correct

> If so, it most somehow know what PCIe slots these devices use?

I have low visibility on the NPU hw internals but I do not think there are
any registers in NPU mmio memory where we can read this info, but I will
confirm it (please remember the fw binaries are not load yet).

Regards,
Lorenzo

> 
>    Andrew

Download attachment "signature.asc" of type "application/pgp-signature" (229 bytes)