Re: [PATCH 2/2] firmware: psci: support SMCCC v1.2 for SMCCC conduit

[Sudeep Holla]

On Thu, May 14, 2020 at 10:21:09AM +0200, Etienne Carriere wrote:
> Update PSCI driver to support SMCCC v1.2 reported by secure firmware
> and indirectly make SMCCC conduit properly set when so. TF-A release
> v2.3 implements and reports SMCCC v1.2 since commit [1].
> 
> Link: [1] https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/commit/?id=e34cc0cedca6e229847c232fe58d37fad2610ce9
> Signed-off-by: Etienne Carriere <etienne.carriere@xxxxxxxxxx>
> ---
>  drivers/firmware/psci/psci.c | 14 ++++++++++----
>  include/linux/psci.h         |  1 +
>  2 files changed, 11 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c
> index 2937d44b5df4..80cf73bea4b0 100644
> --- a/drivers/firmware/psci/psci.c
> +++ b/drivers/firmware/psci/psci.c
> @@ -409,11 +409,17 @@ static void __init psci_init_smccc(void)
>  	feature = psci_features(ARM_SMCCC_VERSION_FUNC_ID);
>  
>  	if (feature != PSCI_RET_NOT_SUPPORTED) {
> -		u32 ret;
> -		ret = invoke_psci_fn(ARM_SMCCC_VERSION_FUNC_ID, 0, 0, 0);
> -		if (ret == ARM_SMCCC_VERSION_1_1) {
> +		ver = invoke_psci_fn(ARM_SMCCC_VERSION_FUNC_ID, 0, 0, 0);
> +
> +		switch (ver) {
> +		case ARM_SMCCC_VERSION_1_1:
>  			psci_ops.smccc_version = SMCCC_VERSION_1_1;
> -			ver = ret;
> +			break;
> +		case ARM_SMCCC_VERSION_1_2:
> +			psci_ops.smccc_version = SMCCC_VERSION_1_2;
> +			break;
> +		default:
> +			break;
>  		}
>  	}
>  
> diff --git a/include/linux/psci.h b/include/linux/psci.h
> index a67712b73b6c..c7d99b7f34ed 100644
> --- a/include/linux/psci.h
> +++ b/include/linux/psci.h
> @@ -24,6 +24,7 @@ bool psci_has_osi_support(void);
>  enum smccc_version {
>  	SMCCC_VERSION_1_0,
>  	SMCCC_VERSION_1_1,
> +	SMCCC_VERSION_1_2,

I took approach to kill this completely [1] instead of having to keep
expanding it for ever.

-- 
Regards,
Sudeep

[1] https://lore.kernel.org/linux-arm-kernel/20200506164411.3284-5-sudeep.holla@xxxxxxx/