Re: [PATCH v5 00/16] introduce a generic IOCTL interface for RPMsg channels management

Arnaud POULIQUEN
2021-03-17T09:30:34Z

On 2/19/21 12:14 PM, Arnaud Pouliquen wrote:
> This series restructures the RPMsg char driver to decorrelate the control part and to
> create a generic RPMsg ioctl interface compatible with other RPMsg services.
>
> The V4 and V5 fix compilation issues reported by the kernel test robot <lkp@intel.com>
> and analyzed by Dan Carpenter <dan.carpenter@oracle.com>.
>
> The V3 is based on the guideline proposed by Mathieu Poirier to keep as much as possible
> the legacy implementation of the rpmsg_char used by the GLINK and SMD platforms.
>
> Objectives of the series:
> - Allow to create a service from Linux user application:
> - with a specific name
> - with or without name service announcement.
> - Allow to probe the same service by receiving either a NS announcement from the remote firmware
> or a Linux user application request.
> - Use these services independently of the RPMsg transport implementation (e.g be able to use
> RPMSg char with the RPMsg virtio bus).
>
> Steps in the series:
> - Extract the control part of the char dev and create the rpmsg_ctrl.c file (patches 1 to 6)
> - Enable the use of the chardev with the virtio backend (patches 7 to 11)
> - Introduce the RPMSG_CREATE_DEV_IOCTL 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.
> - Instantiate the /dev/rpmsg interface on remote NS announcement (patches 13 to 16)
>
> In this revision, I do not divide the series into several parts in order to show a complete
> picture of the proposed evolution. To simplify the review, if requested, I can send it in
> several steps listed above.

No new revision of this series planned, but move forward by splitting it in 3
new series to ease the review.
The first step is addressed here:
https://patchwork.kernel.org/project/linux-remoteproc/list/?series=446305

>
> Known current Limitations:
> - Tested only with virtio RPMsg bus. The glink and smd drivers adaptations have not been tested
> (not able to test it).
> - For the virtio backend: No NS announcement is sent to the remote processor if the source
> address is set to RPMSG_ADDR_ANY.
> - For the virtio backend: the existing RPMSG_CREATE_EPT_IOCTL is working but the endpoints are
> not attached to an exiting channel.
> - to limit patches the pending RPMSG_DESTROY_DEV_IOCTL has not ben implemented. This will be
> proposed in a second step.
>
> This series can be applied on git/andersson/remoteproc.git for-next branch (d9ff3a5789cb).
>
> This series can be tested using rpmsgexport, rpmsgcreatedev and ping tools available here:
> https://github.com/arnopo/rpmsgexport.git
>
> Reference to the V4 discussion thread: https://lkml.org/lkml/2021/2/17/384
>
> Arnaud Pouliquen (16):
> rpmsg: char: rename rpmsg_char_init to rpmsg_chrdev_init
> rpmsg: move RPMSG_ADDR_ANY in user API
> rpmsg: add short description of the IOCTL defined in UAPI.
> rpmsg: char: export eptdev create an destroy functions
> rpmsg: char: dissociate the control device from the rpmsg class
> rpmsg: move the rpmsg control device from rpmsg_char to rpmsg_ctrl
> rpmsg: update rpmsg_chrdev_register_device function
> rpmsg: glink: add sendto and trysendto ops
> rpmsg: smd: add sendto and trysendto ops
> rpmsg: char: use sendto to specify the message destination address
> rpmsg: virtio: register the rpmsg_ctrl device
> rpmsg: ctrl: introduce RPMSG_CREATE_DEV_IOCTL
> rpmsg: char: introduce __rpmsg_chrdev_create_eptdev function
> rpmsg: char: introduce a RPMsg driver for the RPMsg char device
> rpmsg: char: no dynamic endpoint management for the default one
> rpmsg: char: return an error if device already open
>
> drivers/rpmsg/Kconfig | 9 ++
> drivers/rpmsg/Makefile | 1 +
> drivers/rpmsg/qcom_glink_native.c | 18 ++-
> drivers/rpmsg/qcom_smd.c | 18 ++-
> drivers/rpmsg/rpmsg_char.c | 237 +++++++++++-------------------
> drivers/rpmsg/rpmsg_char.h | 51 +++++++
> drivers/rpmsg/rpmsg_ctrl.c | 229 +++++++++++++++++++++++++++++
> drivers/rpmsg/rpmsg_internal.h | 10 +-
> drivers/rpmsg/virtio_rpmsg_bus.c | 57 ++++++-
> include/linux/rpmsg.h | 3 +-
> include/uapi/linux/rpmsg.h | 18 ++-
> 11 files changed, 485 insertions(+), 166 deletions(-)
> create mode 100644 drivers/rpmsg/rpmsg_char.h
> create mode 100644 drivers/rpmsg/rpmsg_ctrl.c
>