Re: kernel.org 6.5.4 , NPU driver, --not support (RFC)

[Oded Gabbay]

On Wed, Sep 27, 2023 at 10:01 AM Cancan Chang <Cancan.Chang@xxxxxxxxxxx> wrote:
>
> “Or do you handle one cmd at a time, where the user sends a cmd buffer
> to the driver and the driver then submit it by writing to a couple of
> registers and polls on some status register until its done, or waits
> for an interrupt to mark it as done ?”
>   --- yes， user sends a cmd buffer to driver, and driver triggers hardware by writing to register,
>         and then, waits for an interrupt to mark it  as done.
>
>     My current driver is very different from drm, so I want to know if I have to switch to drm？
Could you please post a link to the driver's source code ?
In addition, could you please elaborate which userspace libraries
exists that work with your driver ? Are any of them open-source ?

>     Maybe I can refer to /driver/accel/habanalabs.
That's definitely a possibility.

Oded
>
> thanks
>
> ________________________________________
> 发件人: Oded Gabbay <ogabbay@xxxxxxxxxx>
> 发送时间: 2023年9月26日 20:54
> 收件人: Cancan Chang
> 抄送: Jagan Teki; linux-media; linux-kernel; Dave Airlie; Daniel Vetter
> 主题: Re: kernel.org 6.5.4 , NPU driver, --not support (RFC)
>
> [ EXTERNAL EMAIL ]
>
> On Mon, Sep 25, 2023 at 12:29 PM Cancan Chang <Cancan.Chang@xxxxxxxxxxx> wrote:
> >
> > Thank you for your reply from Jagan & Oded.
> >
> > It is very appropritate for my driver to be placed in driver/accel.
> >
> > My accelerator is named ADLA(Amlogic Deep Learning Accelerator).
> > It is an IP in SOC,mainly used for neural network models acceleration.
> > It will split and compile the neural network model into a private format cmd buffer,
> > and submit this cmd buffer to ADLA hardware. It is not programmable device.
> What exactly does it mean to "submit this cmd buffer to ADLA hardware" ?
>
> Does your h/w provides queues for the user/driver to put their
> workloads/cmd-bufs on them ? And does it provide some completion queue
> to notify when the work is completed?
>
> Or do you handle one cmd at a time, where the user sends a cmd buffer
> to the driver and the driver then submit it by writing to a couple of
> registers and polls on some status register until its done, or waits
> for an interrupt to mark it as done ?
>
> >
> > ADLA includes four hardware engines:
> > RS engines             : working for the reshape operators
> > MAC engines         : working for the convolution operators
> > DW engines           : working for the planer & Elementwise operators
> > Activation engines : working for activation operators(ReLu,tanh..)
> >
> > By the way, my IP is mainly used for SOC, and the current driver registration is through the platform_driver,
> > is it necessary to switch to drm?
> This probably depends on the answer to my question above. btw, there
> are drivers in drm that handle IPs that are part of an SOC, so
> platform_driver is supported.
>
> Oded
>
> >
> > thanks.
> >
> > ________________________________________
> > 发件人: Oded Gabbay <ogabbay@xxxxxxxxxx>
> > 发送时间: 2023年9月22日 23:08
> > 收件人: Jagan Teki
> > 抄送: Cancan Chang; linux-media; linux-kernel; Dave Airlie; Daniel Vetter
> > 主题: Re: kernel.org 6.5.4 , NPU driver, --not support (RFC)
> >
> > [你通常不会收到来自 ogabbay@xxxxxxxxxx 的电子邮件。请访问 https://aka.ms/LearnAboutSenderIdentification，以了解这一点为什么很重要;]
> >
> > [ EXTERNAL EMAIL ]
> >
> > On Fri, Sep 22, 2023 at 12:38 PM Jagan Teki <jagan@xxxxxxxxxx> wrote:
> > >
> > > On Fri, 22 Sept 2023 at 15:04, Cancan Chang <Cancan.Chang@xxxxxxxxxxx> wrote:
> > > >
> > > > Dear Media Maintainers:
> > > >      Thanks for your attention. Before describing my problem，let me introduce to you what I  mean by NPU.
> > > >      NPU is Neural Processing Unit, It is designed for deep learning acceleration, It is also called TPU, APU ..
> > > >
> > > >      The real problems:
> > > >       When I was about to upstream my NPU driver codes to linux mainline, i meet two problems:
> > > >         1.  According to my research, There is no NPU module path in the linux (base on linux 6.5.4) , I have searched all linux projects and found no organization or comany that has submitted NPU code. Is there a path prepared for NPU driver currently?
> > > >         2.   If there is no NPU driver path currently, I am going to put my NPU driver code in the drivers/media/platform/amlogic/ , because my NPU driver belongs to amlogic. and amlogic NPU is mainly used for AI vision applications. Is this plan suitabe for you?
> > >
> > > If I'm correct about the discussion with Oded Gabby before. I think
> > > the drivers/accel/ is proper for AI Accelerators including NPU.
> > >
> > > + Oded in case he can comment.
> > >
> > > Thanks,
> > > Jagan.
> > Thanks Jagan for adding me to this thread. Adding Dave & Daniel as well.
> >
> > Indeed, the drivers/accel is the place for Accelerators, mainly for
> > AI/Deep-Learning accelerators.
> > We currently have 3 drivers there already.
> >
> > The accel subsystem is part of the larger drm subsystem. Basically, to
> > get into accel, you need to integrate your driver with the drm at the
> > basic level (registering a device, hooking up with the proper
> > callbacks). ofc the more you use code from drm, the better.
> > You can take a look at the drivers under accel for some examples on
> > how to do that.
> >
> > Could you please describe in a couple of sentences what your
> > accelerator does, which engines it contains, how you program it. i.e.
> > Is it a fixed-function device where you write to a couple of registers
> > to execute workloads, or is it a fully programmable device where you
> > load compiled code into it (GPU style) ?
> >
> > For better background on the accel subsystem, please read the following:
> > https://docs.kernel.org/accel/introduction.html
> > This introduction also contains links to other important email threads
> > and to Dave Airlie's BOF summary in LPC2022.
> >
> > Thanks,
> > Oded