Re: [PATCH v9 00/11] Restructure the rpmsg_char driver and introduce rpmsg_ctrl driver

[Arnaud POULIQUEN <arnaud.pouliquen@foss.st.com>]

On 3/25/22 18:27, Mathieu Poirier wrote:
> On Fri, 25 Mar 2022 at 11:05, Arnaud POULIQUEN
> <arnaud.pouliquen@foss.st.com> wrote:
>>
>>
>>
>> On 3/25/22 16:59, Mathieu Poirier wrote:
>>> On Thu, Mar 24, 2022 at 06:36:23PM +0100, Arnaud POULIQUEN wrote:
>>>> Hi Bjorn,
>>>>
>>>> On 1/24/22 11:25, Arnaud Pouliquen wrote:
>>>>> Updates from V8 [1]:
>>>>> - rebase on 5.17-rc1 + rpmsg char cdev release fixes[2][3]
>>>>> - updates based on Bjorn Andersson's comments:
>>>>>   - remove rpmsg_create_default_ept API, set directly the ept->priv in rpmsg_chrdev_probe
>>>>>     function.
>>>>>   - rework commit message in [8/9]rpmsg: char: Introduce the "rpmsg-raw" channel
>>>>>
>>>>> Patchset description:
>>>>>
>>>>> The current rpmsg_char module implements a /dev/rpmsg_ctrl interface that provides the ability to
>>>>> instantiate char devices (/dev/rpmsgX) associated with an rpmsg endpoint for communication with the
>>>>> remote processor.
>>>>> This implementation fits with QCOM rpmsg backend but not with the magement by chanel implemented
>>>>> in the generic rpmsg virtio backend.
>>>>> This series restructures the rpmsg_char driver to decorrelate the control part from the data part
>>>>> in order to improve its compatible with the rpmsg virtio backend.
>>>>>
>>>>> Objective:
>>>>> - Expose a /dev/rpmsg_ctrlX interface for the application that is no longer dedicated to the
>>>>>   rpmsg_char but generalized to all rpmsg services. This offers capability to create and destroy
>>>>>   rpmsg channels from a user's application initiative (using the new RPMSG_CREATE_DEV_IOCTL and
>>>>>   RPMSG_DESTROY_DEV_IOCTL controls).
>>>>>   An application will be able to create/establish an rpmsg communication channel to communicate
>>>>>   with the remote processor, and not only wait the remote processor initiative.
>>>>>   This is interesting for example to establish a temporary communication link for diagnosis,
>>>>>   calibration, debugging... or instantiate  new data flows on some user actions.
>>>>> - Add capability to probe the rpmsg_char device at the initiative of the remote processor
>>>>>  (rpmsg service announcement mechanism).
>>>>>   This allows platforms based on the rpmsg virtio backend to create the /dev/rpmgX interface with
>>>>>   a rpmsg name service announcement.
>>>>>
>>>>> Subsets:
>>>>>   - Extract the control part of the char dev and create the rpmsg_ctrl.c file (patches 1 to 6)
>>>>>   - Introduce the "rpmsg-raw" channel in rpmsg_char(patches 7 to 10)
>>>>>   - Introduce the RPMSG_CREATE_DEV_IOCTL IOCTL and RPMSG_DESTROY_DEV_IOCTL to instantiate RPMsg
>>>>>     devices (patch 11)
>>>>>     The application can then create or release a channel by specifying:
>>>>>        - the name service of the device to instantiate.
>>>>>        - the source address.
>>>>>        - the destination address.
>>>>>
>>>>> This series has be applied and tested on 'commit e783362eb54c ("Linux 5.17-rc1") +
>>>>> rpmsg_char cdev release fixes [2][3]
>>>>>
>>>>> [1] https://lkml.org/lkml/2021/12/7/186
>>>>> [2] https://lkml.org/lkml/2022/1/10/1129
>>>>> [3] https://lkml.org/lkml/2022/1/10/1130
>>>>>
>>>>> Arnaud Pouliquen (11):
>>>>>   rpmsg: char: Export eptdev create and destroy functions
>>>>>   rpmsg: Create the rpmsg class in core instead of in rpmsg char
>>>>>   rpmsg: Move the rpmsg control device from rpmsg_char to rpmsg_ctrl
>>>>
>>>>
>>>>>   arm: configs: Configs that had RPMSG_CHAR now get RPMSG_CTRL
>>>>>   RISC-V: configs: Configs that had RPMSG_CHAR now get RPMSG_CTRL
>>>>>   arm64: defconfig: Config that had RPMSG_CHAR now gets RPMSG_CTRL
>>>>
>>>> Thank you for merging this series!
>>>>
>>>> I can't see in the "for next" branch[1] the 3 patches above that update configs
>>>> Are you expecting a specific action from me?
>>>
>>> Those patches will need to go through the Arm, RISC-V and arm64 subsystems.  The
>>> mailing list for those subsystems has been CC'ed but that isn't enough to get
>>> the maintainers' attention.
>>>
>>> I suggest sending another patchset with those 3 patches that CC the maintainers
>>> directly.  For the Arm patch I suggest adding Linus Walleij.
>>
>> I will do what you suggest.
>>
>> My concerns in this case is about the scheduling of the integration.
>> I suppose that sending a second patchset for configs requests that the
>> rpmsg char series is first applied
> 
> Right, but the rpmsg_char series has been applied.
> 
>> But on the other hand this may lead to some failures as the RPMSG_CTRL is now
>> needed to create the /dev/rpmsg_ctrl0
>>
> 
> Possibly, but right now there is no other way.
> 
>> so probably, I need to do this as fixup patch.
>>
> 
> Indeed, this can be applied as a fix in rc1.

Yes, that's what I had in mind, I'll do it that way.

Thanks,
Arnaud

> 
>> FYI the RISC-V patch as been reviewed by Anup Patel
>>
> 
> ... but Anup does not maintain any of the defconfig files.
> 
>> Thanks,
>> Arnaud
>>
>>>
>>> Thanks,
>>> Mathieu
>>>
>>>>
>>>> [1]https://git.kernel.org/pub/scm/linux/kernel/git/remoteproc/linux.git
>>>>
>>>> Regards,
>>>> Arnaud
>>>>
>>>>>   rpmsg: Update rpmsg_chrdev_register_device function
>>>>>   rpmsg: char: Refactor rpmsg_chrdev_eptdev_create function
>>>>>   rpmsg: char: Add possibility to use default endpoint of the rpmsg
>>>>>     device
>>>>>   rpmsg: char: Introduce the "rpmsg-raw" channel
>>>>>   rpmsg: ctrl: Introduce new RPMSG_CREATE/RELEASE_DEV_IOCTL controls
>>>>>
>>>>>  arch/arm/configs/qcom_defconfig   |   1 +
>>>>>  arch/arm64/configs/defconfig      |   1 +
>>>>>  arch/riscv/configs/defconfig      |   1 +
>>>>>  arch/riscv/configs/rv32_defconfig |   1 +
>>>>>  drivers/rpmsg/Kconfig             |   8 +
>>>>>  drivers/rpmsg/Makefile            |   1 +
>>>>>  drivers/rpmsg/qcom_glink_native.c |   2 +-
>>>>>  drivers/rpmsg/qcom_smd.c          |   2 +-
>>>>>  drivers/rpmsg/rpmsg_char.c        | 231 +++++++++++-----------------
>>>>>  drivers/rpmsg/rpmsg_char.h        |  46 ++++++
>>>>>  drivers/rpmsg/rpmsg_core.c        |  15 +-
>>>>>  drivers/rpmsg/rpmsg_ctrl.c        | 243 ++++++++++++++++++++++++++++++
>>>>>  drivers/rpmsg/rpmsg_internal.h    |  10 +-
>>>>>  drivers/rpmsg/virtio_rpmsg_bus.c  |   2 +-
>>>>>  include/uapi/linux/rpmsg.h        |  10 ++
>>>>>  15 files changed, 419 insertions(+), 155 deletions(-)
>>>>>  create mode 100644 drivers/rpmsg/rpmsg_char.h
>>>>>  create mode 100644 drivers/rpmsg/rpmsg_ctrl.c
>>>>>