Re: [RFC PATCH v5 0/4] remoteproc: restructure the remoteproc VirtIO device

[Mathieu Poirier <mathieu.poirier@linaro.org>]

I have started looking at this set.  Comments to follow in the coming days.

Thanks,
Mathieu

On Wed, Apr 06, 2022 at 11:54:42AM +0200, Arnaud Pouliquen wrote:
> 1) Update from V4 [1]:
> 
> Minor updates based on Mathieu's comments.
> Updates are listed in the commit message of each patch.
> 
> [1] https://lkml.org/lkml/2022/3/14/1177
> 
> 2) Patchset description:
> 
> This series is a part of the work initiated a long time ago in 
> the series "remoteproc: Decorelate virtio from core"[2]
> 
> 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 [3][4]
> 
> [2] https://lkml.org/lkml/2020/4/16/1817
> [3] https://lkml.org/lkml/2021/6/23/607
> [4] 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 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 virtio device add/remove functions
>   remoteproc: core: Introduce rproc_register_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   | 193 ++++++++++++++++++++---
>  include/linux/remoteproc.h               |   6 +-
>  4 files changed, 215 insertions(+), 161 deletions(-)
> 
> -- 
> 2.25.1
>