Subject: Re: [PATCH v8 00/13] Restructure the rpmsg_char driver and introduce
 rpmsg_ctrl driver
To:     Bjorn Andersson <bjorn.andersson@linaro.org>,
        Mathieu Poirier <mathieu.poirier@linaro.org>
CC:     <linux-remoteproc@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <linux-stm32@st-md-mailman.stormreply.com>, <julien.massot@iot.bzh>
References: <20211207080843.21222-1-arnaud.pouliquen@foss.st.com>
From:   Arnaud POULIQUEN <arnaud.pouliquen@foss.st.com>
Message-ID: <b5b3f474-f84d-d682-2987-a6f812da0710@foss.st.com>
Date:   Mon, 10 Jan 2022 09:48:39 +0100
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Hello Bjorn,


On 12/7/21 9:08 AM, Arnaud Pouliquen wrote:
> Update from V7 [1]:
> - miscellaneous fixes based on Bjorn Andersson's comments
> - add "arm64: defconfig: Config that had RPMSG_CHAR now gets RPMSG_CTRL"
>    for 5.16 compatibility

Gentle reminder.
Any new comment or concern on this patchset?

Regards,
Arnaud

> 
> 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 fit with QCOM rpmsg backend but not with themagement 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 11)
>    - Introduce the RPMSG_CREATE_DEV_IOCTL IOCTL and RPMSG_DESTROY_DEV_IOCTL to instantiate RPMsg
>      devices (patch 12)
>      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.
>    - Send a ns announcement to the remote processor on default endpoint creation (patche 13)
> 
> This series has be applied and tested on for-next branch 'c4b39a582b9b)[2].
> 
> [1] https://lkml.org/lkml/2021/11/8/501
> [2] https://git.kernel.org/pub/scm/linux/kernel/git/remoteproc/linux.git
> 
> Arnaud Pouliquen (10):
>    rpmsg: char: Export eptdev create an 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
>    rpmsg: Update rpmsg_chrdev_register_device function
>    rpmsg: char: Refactor rpmsg_chrdev_eptdev_create function
>    rpmsg: Introduce rpmsg_create_default_ept 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
>    rpmsg: core: Send a ns announcement when a default endpoint is created
> 
>   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        | 246 +++++++++++------------------
>   drivers/rpmsg/rpmsg_char.h        |  46 ++++++
>   drivers/rpmsg/rpmsg_core.c        |  84 +++++++++-
>   drivers/rpmsg/rpmsg_ctrl.c        | 250 ++++++++++++++++++++++++++++++
>   drivers/rpmsg/rpmsg_internal.h    |  14 +-
>   drivers/rpmsg/virtio_rpmsg_bus.c  |   2 +-
>   include/uapi/linux/rpmsg.h        |  10 ++
>   15 files changed, 505 insertions(+), 164 deletions(-)
>   create mode 100644 drivers/rpmsg/rpmsg_char.h
>   create mode 100644 drivers/rpmsg/rpmsg_ctrl.c
>