RE: [XEN PATCH v8 09/22] xen/arm: ffa: add direct request support

[Henry Wang <Henry.Wang@xxxxxxx>]

Hi Jens,

> -----Original Message-----
> Subject: [XEN PATCH v8 09/22] xen/arm: ffa: add direct request support
> 
> Adds support for sending a FF-A direct request. Checks that the SP also
> supports handling a 32-bit direct request. 64-bit direct requests are
> not used by the mediator itself so there is not need to check for that.
> 
> Signed-off-by: Jens Wiklander <jens.wiklander@xxxxxxxxxx>
> ---
>  xen/arch/arm/tee/ffa.c | 112
> +++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 112 insertions(+)
> 
> diff --git a/xen/arch/arm/tee/ffa.c b/xen/arch/arm/tee/ffa.c
> index f129879c5b81..f2cce955d981 100644
> --- a/xen/arch/arm/tee/ffa.c
> +++ b/xen/arch/arm/tee/ffa.c
> @@ -181,6 +181,56 @@ static bool ffa_get_version(uint32_t *vers)
>      return true;
>  }
> 
> +static int32_t get_ffa_ret_code(const struct arm_smccc_1_2_regs *resp)
> +{
> +    switch ( resp->a0 )
> +    {
> +    case FFA_ERROR:
> +        if ( resp->a2 )
> +            return resp->a2;
> +        else
> +            return FFA_RET_NOT_SUPPORTED;
> +    case FFA_SUCCESS_32:
> +    case FFA_SUCCESS_64:
> +        return FFA_RET_OK;
> +    default:
> +        return FFA_RET_NOT_SUPPORTED;
> +    }
> +}
> +
> +static int32_t ffa_simple_call(uint32_t fid, register_t a1, register_t a2,
> +                               register_t a3, register_t a4)
> +{
> +    const struct arm_smccc_1_2_regs arg = {
> +        .a0 = fid,
> +        .a1 = a1,
> +        .a2 = a2,
> +        .a3 = a3,
> +        .a4 = a4,
> +    };
> +    struct arm_smccc_1_2_regs resp;
> +
> +    arm_smccc_1_2_smc(&arg, &resp);
> +
> +    return get_ffa_ret_code(&resp);
> +}
> +
> +static int32_t ffa_features(uint32_t id)
> +{
> +    return ffa_simple_call(FFA_FEATURES, id, 0, 0, 0);
> +}
> +
> +static bool check_mandatory_feature(uint32_t id)
> +{
> +    int32_t ret = ffa_features(id);
> +
> +    if (ret)

Coding style nit: You need spaces before and after "ret", i.e.
if ( ret )

With this fixed:

Reviewed-by: Henry Wang <Henry.Wang@xxxxxxx>

Kind regards,
Henry