Re: [PATCH 1/7] iommu/arm-smmu-qcom: apply num_context_bank fixes for SDM630 / SDM660

[Bjorn Andersson]

On Sat, Sep 07, 2024 at 09:48:12PM GMT, Dmitry Baryshkov wrote:
> The Qualcomm SDM630 / SDM660 platform requires the same kind of
> workaround as MSM8998: some IOMMUs have context banks reserved by
> firmware / TZ, touching those banks resets the board.
> 
> Apply the num_context_bank workaround to those two SMMU devices in order
> to allow them to be used by Linux.
> 
> Fixes: b812834b5329 ("iommu: arm-smmu-qcom: Add sdm630/msm8998 compatibles for qcom quirks")
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>

Reviewed-by: Bjorn Andersson <andersson@xxxxxxxxxx>

> ---
>  drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
> index 087fb4f6f4d3..13a3e3585c89 100644
> --- a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
> +++ b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
> @@ -288,6 +288,12 @@ static int qcom_smmu_cfg_probe(struct arm_smmu_device *smmu)
>  	 */
>  	if (of_device_is_compatible(smmu->dev->of_node, "qcom,msm8998-smmu-v2") && smmu->num_context_banks == 13)
>  		smmu->num_context_banks = 12;

This should now be wrapped in {}

Regards,
Bjorn

> +	else if (of_device_is_compatible(smmu->dev->of_node, "qcom,sdm630-smmu-v2")) {
> +		if (smmu->num_context_banks == 21) /* SDM630 / SDM660 A2NOC SMMU */
> +			smmu->num_context_banks = 7;
> +		else if (smmu->num_context_banks == 14) /* SDM630 / SDM660 LPASS SMMU */
> +			smmu->num_context_banks = 13;
> +	}
>  
>  	/*
>  	 * Some platforms support more than the Arm SMMU architected maximum of
> @@ -350,6 +356,11 @@ static int qcom_adreno_smmuv2_cfg_probe(struct arm_smmu_device *smmu)
>  	/* Support for 16K pages is advertised on some SoCs, but it doesn't seem to work */
>  	smmu->features &= ~ARM_SMMU_FEAT_FMT_AARCH64_16K;
>  
> +	/* TZ protects several last context banks, hide them from Linux */
> +	if (of_device_is_compatible(smmu->dev->of_node, "qcom,sdm630-smmu-v2") &&
> +	    smmu->num_context_banks == 5)
> +		smmu->num_context_banks = 2;
> +
>  	return 0;
>  }
>  
> 
> -- 
> 2.39.2
>