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

[Oded Gabbay]

On 11/01/2024 10:04, Tomeu Vizoso wrote:
> Hi Oded,
>
> Out of curiosity, did you end up taking a look at Amlogic's driver?
>
> Cheers,
>
> Tomeu
Hi Tomeu,
Yes, I have looked at the driver's code. It was not an in-depth review, 
but I tried to mainly understand the features the driver provide to the 
user and how much complex it is.

From what I could see, this is a full-fledged accelerator which 
requires command submission/completion handling, memory management, 
information and debug capabilities and more.

Therefore, I do think the correct place is in the accel sub-system, 
which will require you to convert the driver to use drm (we can discuss 
exactly what is the level of integration required).

As I said, I didn't do a full-fledged review, but please note the driver 
has a lot of OS-wrapper code, which is not acceptable in the Linux 
kernel, so you will have to clean all the up.

Thanks,
Oded

> On Sat, Oct 7, 2023 at 8:37 AM Cancan Chang <Cancan.Chang@xxxxxxxxxxx> wrote:
> > Oded,
> >         You can get the driver code from  github link： https://github.com/OldDaddy9/driver
> >          e.g.  git clone https://github.com/OldDaddy9/driver.git
> >
> > ________________________________________
> > 发件人: Oded Gabbay <ogabbay@xxxxxxxxxx>
> > 发送时间: 2023年10月3日 18:52
> > 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 Thu, Sep 28, 2023 at 11:16 AM Cancan Chang <Cancan.Chang@xxxxxxxxxxx> wrote:
> > > “What happens if you call this again without waiting for the previous
> > > inference to complete ?”
> > >     --- There is a work-queue in the driver to manage inference tasks.
> > >           When two consecutive inference tasks occur, the second inference task will be add to
> > >           the "pending list". While the previous inference task ends, the second inference task will
> > >           switch to the "scheduled list", and be executed.
> > >           Each inference task has an id,  "inferece" and "wait until finish" are paired.
> > >
> > >           thanks
> > Thanks for the clarification.
> > I'll wait for your driver's code link. It doesn't have to be a patch
> > series at this point. A link to a git repo is enough.
> > I just want to do a quick pass.
> >
> > Thanks,
> > Oded
> >
> >
> >
> > > ________________________________________
> > > 发件人: Oded Gabbay <ogabbay@xxxxxxxxxx>
> > > 发送时间: 2023年9月28日 15:40
> > > 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 Thu, Sep 28, 2023 at 10:25 AM Cancan Chang <Cancan.Chang@xxxxxxxxxxx> wrote:
> > > > “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 ?”
> > > > --- We will prepare the adla driver link after the holiday on October 6th.
> > > >       It's a pity that there is no open-source userspace library.
> > > >       But you can probably understand it through a workflow, which can be simplified as:
> > > >       1. create model context
> > > >            ret = ioctl(context->fd, ADLAK_IOCTL_REGISTER_NETWORK, &desc);
> > > >       2.  set inputs
> > > >       3.  inference
> > > >             ret = ioctl(context->fd, ADLAK_IOCTL_INVOKE, &invoke_dec);
> > > What happens if you call this again without waiting for the previous
> > > inference to complete ?
> > > Oded
> > > >       4.  wait for the inference to complete
> > > >             ret = ioctl(context->fd, ADLAK_IOCTL_WAIT_UNTIL_FINISH, &stat_req_desc);
> > > >       5.  destroy model context
> > > >             ret = ioctl(context->fd, ADLAK_IOCTL_DESTROY_NETWORK, &submit_del);
> > > >
> > > >
> > > >        thanks
> > > >
> > > >
> > > > ________________________________________
> > > > 发件人: Oded Gabbay <ogabbay@xxxxxxxxxx>
> > > > 发送时间: 2023年9月28日 13:28
> > > > 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 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