[PATCH] firmware: arm_ffa: Allow the FF-A drivers to use 32bit mode of messaging

[Jens Wiklander]

Hi Sudeep,

On Thu, Oct 5, 2023 at 4:28 PM Sudeep Holla <sudeep.holla at arm.com> wrote:
>
> An FF-A ABI could support both the SMC32 and SMC64 conventions.
> A callee that runs in the AArch64 execution state and implements such
> an ABI must implement both SMC32 and SMC64 conventions of the ABI.
>
> So the FF-A drivers will need the option to choose the mode irrespective
> of FF-A version and the partition execution mode flag in the partition
> information.
>
> Let us remove the check on the FF-A version for allowing the selection
> of 32bit mode of messaging. The driver will continue to set the 32-bit
> mode if the partition execution mode flag specified that the partition
> supports only 32-bit execution.
>
> Signed-off-by: Sudeep Holla <sudeep.holla at arm.com>
> ---
>  drivers/firmware/arm_ffa/driver.c | 12 ++----------
>  1 file changed, 2 insertions(+), 10 deletions(-)
>
> Hi Jens,
>
> Based on our discussion in private, I am posting this patch. I am not marking
> fixes tag as the driver version is not yet bumped in the mainline. But if you
> think it is better to add, I can update when pulling in the change. Let me
> know.

A fixes tag would be nice, to make sure that this patch isn't missed.

Thanks,
Jens

>
> Regards,
> Sudeep
>
> diff --git a/drivers/firmware/arm_ffa/driver.c b/drivers/firmware/arm_ffa/driver.c
> index 121f4fc903cd..7cd6b1564e80 100644
> --- a/drivers/firmware/arm_ffa/driver.c
> +++ b/drivers/firmware/arm_ffa/driver.c
> @@ -587,17 +587,9 @@ static int ffa_partition_info_get(const char *uuid_str,
>         return 0;
>  }
>
> -static void _ffa_mode_32bit_set(struct ffa_device *dev)
> -{
> -       dev->mode_32bit = true;
> -}
> -
>  static void ffa_mode_32bit_set(struct ffa_device *dev)
>  {
> -       if (drv_info->version > FFA_VERSION_1_0)
> -               return;
> -
> -       _ffa_mode_32bit_set(dev);
> +       dev->mode_32bit = true;
>  }
>
>  static int ffa_sync_send_receive(struct ffa_device *dev,
> @@ -706,7 +698,7 @@ static void ffa_setup_partitions(void)
>
>                 if (drv_info->version > FFA_VERSION_1_0 &&
>                     !(tpbuf->properties & FFA_PARTITION_AARCH64_EXEC))
> -                       _ffa_mode_32bit_set(ffa_dev);
> +                       ffa_mode_32bit_set(ffa_dev);
>         }
>         kfree(pbuf);
>  }
> --
> 2.42.0
>