RE: [RFC PATCH v3 0/4] remoteproc: restructure the remoteproc VirtIO device

Peng Fan
2022-02-15T08:34:54Z

> Subject: [RFC PATCH v3 0/4] remoteproc: restructure the remoteproc VirtIO
> device
>
> Update from V2 [1]:
> In order to better handle error cases and to have something more
> symmetrical between the functions in charge of rvdev initialization/deletion,
> the patchset has been reworked.
> - Introduction in the first patch, of rproc_vdev_data structure which allows
> to better
> decorrelate the rproc from the management of the rvdev structure. This
> structure is reused
> in the last patch of the series for the creation of the remoteproc virtio
> platform device.
> - In addition to the previous version, the management of the vring lifecycle
> has been fully
> migrated to the remoteproc_virtio.c (rproc_parse_vring, rproc_alloc_vring,
> rproc_free_vring)
>
> [1]
> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flkml.or
> g%2Flkml%2F2021%2F12%2F22%2F111&amp;data=04%7C01%7Cpeng.fan%4
> 0nxp.com%7C9e663eefc30a4fbb1fdb08d9e0e855e2%7C686ea1d3bc2b4c6fa
> 92cd99c5c301635%7C0%7C0%7C637788110748757786%7CUnknown%7CT
> WFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLC
> JXVCI6Mn0%3D%7C3000&amp;sdata=bFfSxpPMpPRGYcMBcwxaQ152mRzf3c
> fwoFPjiJ0SIgw%3D&amp;reserved=0
>
> 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

This means not using resource table anymore with new approach?
If yes, would that introduce a problem that different M-core images
requires different dtb?

> - 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.

As my understanding virtio-i2c is a i2c bus, you could declare a i2c device
in the virtual bus without your patchset, would you please share more?

Thanks,
Peng.

> - Keep the legacy working!
> - Try to improve the picture about concerns reported by Christoph Hellwing
> [3][4]
>
> [2]
> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flkml.or
> g%2Flkml%2F2020%2F4%2F16%2F1817&amp;data=04%7C01%7Cpeng.fan%4
> 0nxp.com%7C9e663eefc30a4fbb1fdb08d9e0e855e2%7C686ea1d3bc2b4c6fa
> 92cd99c5c301635%7C0%7C0%7C637788110748757786%7CUnknown%7CT
> WFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLC
> JXVCI6Mn0%3D%7C3000&amp;sdata=O2BZw5PCY19eD5xMGxrGUKC%2Fty1
> Sdc3LE6rhK4cSXvs%3D&amp;reserved=0
> [3]
> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flkml.or
> g%2Flkml%2F2021%2F6%2F23%2F607&amp;data=04%7C01%7Cpeng.fan%40
> nxp.com%7C9e663eefc30a4fbb1fdb08d9e0e855e2%7C686ea1d3bc2b4c6fa9
> 2cd99c5c301635%7C0%7C0%7C637788110748757786%7CUnknown%7CTW
> FpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJX
> VCI6Mn0%3D%7C3000&amp;sdata=xqX50iDeL%2BtFBOgyADnEUE5HH4gogK
> C0MwyqZSxVqNo%3D&amp;reserved=0
> [4]
> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fpatch
> work.kernel.org%2Fproject%2Flinux-remoteproc%2Fpatch%2FAOKowLclCbO
> CKxyiJ71WeNyuAAj2q8EUtxrXbyky5E%40cp7-web-042.plabs.ch%2F&amp;da
> ta=04%7C01%7Cpeng.fan%40nxp.com%7C9e663eefc30a4fbb1fdb08d9e0e85
> 5e2%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C637788110748
> 757786%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2
> luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&amp;sdata=mvSm3wM
> LgQ%2BDFhqjXIkG8de58zFjwPSURzw55JhGNaA%3D&amp;reserved=0
>
> In term of device tree this would result in such hiearchy (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 prob a VirtIO sub node
> - VirtIO bindings declaration,
> - multi DT VirtIO devices support,
> - introduction of a remote proc virtio bind device mechanism , =>
> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.
> com%2Farnopo%2Flinux%2Fcommits%2Fstep2-virtio-in-DT&amp;data=04%7
> C01%7Cpeng.fan%40nxp.com%7C9e663eefc30a4fbb1fdb08d9e0e855e2%7C
> 686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C637788110748757786
> %7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiL
> CJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&amp;sdata=X%2B462681gcxe6
> 2GP%2BV7ji2nef%2FuTbQVvIlddcMQwtmg%3D&amp;reserved=0
> step 3: Add memory declaration in VirtIO subnode =>
> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.
> com%2Farnopo%2Flinux%2Fcommits%2Fstep3-virtio-memories&amp;data=0
> 4%7C01%7Cpeng.fan%40nxp.com%7C9e663eefc30a4fbb1fdb08d9e0e855e2
> %7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C637788110748757
> 786%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luM
> zIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&amp;sdata=eMlXgCgrV6l46
> h3Ywv1%2BCoX3gLBabdTZs9ybsm4t4ys%3D&amp;reserved=0
> step 4: Add mailbox declaration in VirtIO subnode =>
> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.
> com%2Farnopo%2Flinux%2Fcommits%2Fstep4-virtio-mailboxes&amp;data=0
> 4%7C01%7Cpeng.fan%40nxp.com%7C9e663eefc30a4fbb1fdb08d9e0e855e2
> %7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C637788110748757
> 786%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luM
> zIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&amp;sdata=75hApOwihqMZ
> UUKz1VcitY2VPDc6KAIwAvH8enEZOPY%3D&amp;reserved=0
>
> 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 | 159 +++----------------
> drivers/remoteproc/remoteproc_internal.h | 33 +++-
> drivers/remoteproc/remoteproc_virtio.c | 193
> ++++++++++++++++++++---
> include/linux/remoteproc.h | 6 +-
> 4 files changed, 227 insertions(+), 164 deletions(-)
>
> --
> 2.25.1