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Date:   Mon, 19 Sep 2022 16:30:27 -0600
From:   Mathieu Poirier <mathieu.poirier@linaro.org>
To:     Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>
Cc:     Bjorn Andersson <bjorn.andersson@linaro.org>,
        linux-remoteproc@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-stm32@st-md-mailman.stormreply.com,
        Rob Herring <robh@kernel.org>, Christoph Hellwig <hch@lst.de>,
        Stefano Stabellini <stefanos@xilinx.com>,
        Bruce Ashfield <bruce.ashfield@xilinx.com>
Subject: Re: [PATCH v8 0/4] remoteproc: restructure the remoteproc VirtIO
 device
Message-ID: <20220919223027.GG759648@p14s>
References: <20220826115232.2163130-1-arnaud.pouliquen@foss.st.com>
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Hi,

On Fri, Aug 26, 2022 at 01:52:28PM +0200, Arnaud Pouliquen wrote:
> 1) Update from V7 [1]:
> 
> - rebase on rproc-next branch [2], commit 729c16326b7f ("remoteproc: imx_dsp_rproc: fix argument 2 of rproc_mem_entry_init")
>   The updates take into account the integration of the
>   commit 1404acbb7f68 ("remoteproc: Fix dma_mem leak after rproc_shutdown")
> - add Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> according to reviews on V7
> 
> 
> [1] https://lkml.org/lkml/2022/7/13/663
> [2] https://git.kernel.org/pub/scm/linux/kernel/git/remoteproc/linux.git/log/?h=for-next
> 
> 2) Patchset description:
> 
> This series is a part of the work initiated a long time ago in 
> the series "remoteproc: Decorelate virtio from core"[3]
> 
> Objective of the work:
> - Update the remoteproc VirtIO device creation (use platform device)
> - Allow to declare remoteproc VirtIO device in DT
>     - declare resources associated to a remote proc VirtIO
>     - declare a list of VirtIO supported by the platform.
> - Prepare the enhancement to more VirtIO devices (e.g I2C, audio, video, ...).
>   For instance be able to declare a I2C device in a virtio-i2C node.
> - Keep the legacy working!
> - Try to improve the picture about concerns reported by Christoph Hellwing [4][5]
> 
> [3] https://lkml.org/lkml/2020/4/16/1817
> [4] https://lkml.org/lkml/2021/6/23/607
> [5] https://patchwork.kernel.org/project/linux-remoteproc/patch/AOKowLclCbOCKxyiJ71WeNyuAAj2q8EUtxrXbyky5E@cp7-web-042.plabs.ch/
> 
> In term of device tree this would result in such hierarchy (stm32mp1 example with 2 virtio RPMSG):
> 
> 	m4_rproc: m4@10000000 {
> 		compatible = "st,stm32mp1-m4";
> 		reg = <0x10000000 0x40000>,
> 		      <0x30000000 0x40000>,
> 		      <0x38000000 0x10000>;
>         memory-region = <&retram>, <&mcuram>,<&mcuram2>;
>         mboxes = <&ipcc 2>, <&ipcc 3>;
>         mbox-names = "shutdown", "detach";
>         status = "okay";
> 
>         #address-cells = <1>;
>         #size-cells = <0>;
>         
>         vdev@0 {
> 		compatible = "rproc-virtio";
> 		reg = <0>;
> 		virtio,id = <7>;  /* RPMSG */
> 		memory-region = <&vdev0vring0>, <&vdev0vring1>, <&vdev0buffer>;
> 		mboxes = <&ipcc 0>, <&ipcc 1>;
> 		mbox-names = "vq0", "vq1";
> 		status = "okay";
>         };
> 
>         vdev@1 {
> 		compatible = "rproc-virtio";
> 		reg = <1>;
> 		virtio,id = <7>;  /*RPMSG */
> 		memory-region = <&vdev1vring0>, <&vdev1vring1>, <&vdev1buffer>;
> 		mboxes = <&ipcc 4>, <&ipcc 5>;
> 		mbox-names = "vq0", "vq1";
> 		status = "okay";
>         };
> };

I was in the process of applying this set when the last patch gave me a
checkpatch warning about "virtio,rproc" not being documented.

I suggest to introduce a new "virtio-rproc.yaml" based on this work[1], with the
above in the example sections.

Thanks,
Mathieu

[1]. https://elixir.bootlin.com/linux/v6.0-rc6/source/Documentation/devicetree/bindings/virtio/virtio-device.yaml


> 
> I have divided the work in 4 steps to simplify the review, This series implements only
> the step 1:
> step 1: Redefine the remoteproc VirtIO device as a platform device
>   - migrate rvdev management in remoteproc virtio.c,
>   - create a remotproc virtio config ( can be disabled for platform that not use VirtIO IPC.
> step 2: Add possibility to declare and probe a VirtIO sub node
>   - VirtIO bindings declaration,
>   - multi DT VirtIO devices support,
>   - introduction of a remote proc virtio bind device mechanism ,
> => https://github.com/arnopo/linux/commits/step2-virtio-in-DT
> step 3: Add memory declaration in VirtIO subnode
> => https://github.com/arnopo/linux/commits/step3-virtio-memories
> step 4: Add mailbox declaration in VirtIO subnode
> => https://github.com/arnopo/linux/commits/step4-virtio-mailboxes
> 
> Arnaud Pouliquen (4):
>   remoteproc: core: Introduce rproc_rvdev_add_device function
>   remoteproc: core: Introduce rproc_add_rvdev function
>   remoteproc: Move rproc_vdev management to remoteproc_virtio.c
>   remoteproc: virtio: Create platform device for the remoteproc_virtio
> 
>  drivers/remoteproc/remoteproc_core.c     | 154 +++---------------
>  drivers/remoteproc/remoteproc_internal.h |  23 ++-
>  drivers/remoteproc/remoteproc_virtio.c   | 189 ++++++++++++++++++++---
>  include/linux/remoteproc.h               |   6 +-
>  4 files changed, 210 insertions(+), 162 deletions(-)
> 
> -- 
> 2.24.3
>