RE: [PATCH 0/8] Make SCMI transport as standalone drivers

Peng Fan
2024-07-11T13:26:19Z

> Subject: [PATCH 0/8] Make SCMI transport as standalone drivers

You may need use V2 here :)
>
> Hi all,
>
> Till now the SCMI transport layer was being built embedded into in the
> core SCMI stack.
>
> Some of these transports, despite being currently part of the main
> SCMI module, are indeed also registered with different subsystems like
> optee or virtio, and actively probed also by those: this led to a few
> awkward and convoluted tricks to properly handle such interactions at
> boot time in the SCMI stack.
>
> Moreover some partner expressed the desire to be able to fully
> modularize the transports components.
>
> This series aim to make all such transports as standalone drivers that
> can be optionally loaded as modules.
>
> In order to do this, at first some new mechanism is introduced to
> support this new capability while maintaining, in parallel, the old
> legacy embedded transports; then each transport, one by one, is
> transitioned to be a standalone driver and finally the old legacy
> support for embedded transport is removed.
>
> Patch [1/8] is a mostly unrelated (but much needed) clean-up from
> Peng, which I included in this series to avoid conflicts at merge.
>
> Patch [2/8] simply collects the existing datagram manipulation helpers
> in a pair of function pointers structures, in preparation for later reworks.
>
> Patch [3/8] adds the bulk of the new logic to the core SCMI stack and
> then each existing transport is transitioned to be a standalone driver in
> patches 4,5,6,7 while shuffling around the compatibles. (no DT change
> is needed of curse for backward compatibility) While doing this I kept
> the module authorship in line with the main
> author(S) as spitted out by git-blame.
>
> Finally patch [8/8] removes all the legacy dead code from the core
> SCMI stack.
>
> No new symbol EXPORT has been added.
>
> The new transport drivers have been tested, as built-in and LKM, as
> follows:
>
> - mailbox on JUNO
> - virtio on emulation
> - optee on QEMU/optee using Linaro setup
>
> Exercised using the regular SCMI drivers stack and the SCMI ACS suite,
> testing commands, replies, delayed responses and notification.
>
> Multiple virtual SCMI instances support has been tested too.
>
> SMC has NOT been tested/exercised at run-time, only compile-tested.
> (due to lack of hardware)
>
> Note that in this new setup, all the probe deferral and retries between
> the SCMI core stack and the transports has been removed, since no
> more needed.
>
> Moreover the new drivers have been tested also with a fully
> modularized SCMI stack, i.e.:
>
> scmi-core.ko + scmi-module.ko + scmi_transport_*.ko [ + vendor
> modules ]
>
> ToBeDone:
> - completely remove any dependency at build time at the Kconfig level
> between
> the SCMI core and the transport drivers: so that the transports will be
> dependent only on the related subsystems (optee/virtio/mailbox/smc)
> (easy to be done but maybe it is not worth...)
> - integrate per-platform transport configuration capabilities
> (max_rx_timeout_ms & friends..)
>
> Based on sudeep/for-next/scmi/updates.
>
> Any feedback, and especially testing (:D) is welcome.
>

For the v2 patchset:
Tested-by: Peng Fan <peng.fan@nxp.com> #i.MX95-19x19-EVK

Regards,
Peng.

> Thanks,
> Cristian
>
> ---
> v1 --> v2
> - fixed setup_shmem_iomap to address also SMC needs (QC/nikunj)
> (silencing also warnings by kernel test robot <lkp@intel.com>)
> - using __free OF cleanup.h magic in setup_shmme_iomap
> - properly handle platform_driver_register() failures (Dan)
> - fixed a few commit message style
> - added a few missing static in scmi_desc
> (addresses warnings by kernel test robot <lkp@intel.com>)
>
> Cristian Marussi (7):
> firmware: arm_scmi: Introduce packet handling helpers
> firmware: arm_scmi: Add support for standalone transport drivers
> firmware: arm_scmi: Make MBOX transport a standalone driver
> firmware: arm_scmi: Make SMC transport a standalone driver
> firmware: arm_scmi: Make OPTEE transport a standalone driver
> firmware: arm_scmi: Make VirtIO transport a standalone driver
> firmware: arm_scmi: Remove legacy transport-layer code
>
> Peng Fan (1):
> firmware: arm_scmi: Introduce setup_shmem_iomap
>
> drivers/firmware/arm_scmi/Kconfig | 20 +-
> drivers/firmware/arm_scmi/Makefile | 9 +-
> drivers/firmware/arm_scmi/common.h | 184 +++++++++++++----
> -
> drivers/firmware/arm_scmi/driver.c | 140 +++++--------
> drivers/firmware/arm_scmi/msg.c | 34 +++-
> .../{mailbox.c => scmi_transport_mailbox.c} | 69 ++++---
> .../{optee.c => scmi_transport_optee.c} | 124 +++++-------
> .../arm_scmi/{smc.c => scmi_transport_smc.c} | 58 +++---
> .../{virtio.c => scmi_transport_virtio.c} | 103 +++++-----
> drivers/firmware/arm_scmi/shmem.c | 85 ++++++--
> 10 files changed, 468 insertions(+), 358 deletions(-) rename
> drivers/firmware/arm_scmi/{mailbox.c => scmi_transport_mailbox.c}
> (87%) rename drivers/firmware/arm_scmi/{optee.c =>
> scmi_transport_optee.c} (89%) rename
> drivers/firmware/arm_scmi/{smc.c => scmi_transport_smc.c} (87%)
> rename drivers/firmware/arm_scmi/{virtio.c => scmi_transport_virtio.c}
> (94%)
>
> --
> 2.45.2
>