[v4,0/2] Support for I/O width within ARM SCMI SHMEM

Message

Florian Fainelli Aug. 27, 2024, 6:24 p.m. UTC

We just got our hands on hardware that only supports 32-bit access width
to the SRAM being used. This patch series adds support for the
'reg-io-width' property and allows us to specify the exact access width
that the SRAM supports.

Changes in v4:

- added alignment warnings in case the source/destination/count are not
  a 4 bytes multiple
- switched to __ioread32_copy/__iowrite32_copy per Sudeep's suggestion
- dropped volatile qualifiers to permit that switch

Changes in v3:

- added missing documentation for the structure members being added
- removed the use of a macro for the 32-bit only operation, this
  gets rid of a number of checkpatch warnings
- added missing trailing barriers
- corrected binding indentation

Changes in v2:

- fixed typo in the binding and added reviewed-by tag from Krzysztof

- determine the correct I/O operation at the time we parse the
  'reg-io-width' property rather than for each
  tx_prepare/fetch_response/fetch_notification call

- dropped support for 1 and 2 bytes 'reg-io-width' as they do not quite
  make sense, if we can support such smaller access size, then we can
  support the larger 4 byte access width, too, and there are many places
  within the SCMI code where ioread32/iowrite32 are used

Florian Fainelli (2):
  dt-bindings: sram: Document reg-io-width property
  firmware: arm_scmi: Support 'reg-io-width' property for shared memory

 .../devicetree/bindings/sram/sram.yaml        |  6 ++
 drivers/firmware/arm_scmi/common.h            | 32 +++++++-
 .../arm_scmi/scmi_transport_mailbox.c         | 13 +++-
 .../firmware/arm_scmi/scmi_transport_optee.c  | 11 ++-
 .../firmware/arm_scmi/scmi_transport_smc.c    | 11 ++-
 drivers/firmware/arm_scmi/shmem.c             | 78 +++++++++++++++++--
 6 files changed, 130 insertions(+), 21 deletions(-)

Comments

Sudeep Holla Nov. 6, 2024, 7:23 a.m. UTC | #1

On Tue, 27 Aug 2024 11:24:48 -0700, Florian Fainelli wrote:
> We just got our hands on hardware that only supports 32-bit access width
> to the SRAM being used. This patch series adds support for the
> 'reg-io-width' property and allows us to specify the exact access width
> that the SRAM supports.
> 
> Changes in v4:
> 
> [...]

(with some trivial rebasing)

Applied to sudeep.holla/linux (for-next/scmi/updates), thanks!

[1/2] dt-bindings: sram: Document reg-io-width property
      https://git.kernel.org/sudeep.holla/c/14b2157a9c14
[2/2] firmware: arm_scmi: Support 'reg-io-width' property for shared memory
      https://git.kernel.org/sudeep.holla/c/2cd7f3db25fe

--
Regards,
Sudeep