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

From: Oded Gabbay
Date: Tue Oct 03 2023 - 06:53:28 EST


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