Re: [PATCH v3 6/6] iommu/qcom: Add support for QSMMUv2 and QSMMU-500 secured contexts

[Dmitry Baryshkov]

On 15/11/2022 12:11, AngeloGioacchino Del Regno wrote:
> On some SoCs like MSM8956, MSM8976 and others, secure contexts are
> also secured: these get programmed by the bootloader or TZ (as usual)
> but their "interesting" registers are locked out by the hypervisor,
> disallowing direct register writes from Linux and, in many cases,
> completely disallowing the reprogramming of TTBR, TCR, MAIR and other
> registers including, but not limited to, resetting contexts.
> This is referred downstream as a "v2" IOMMU but this is effectively
> a "v2 firmware configuration" instead.
>
> Luckily, the described behavior of version 2 is effective only on
> secure contexts and not on non-secure ones: add support for that,
> finally getting a completely working IOMMU on at least MSM8956/76.
>
> Signed-off-by: Marijn Suijten <marijn.suijten@xxxxxxxxxxxxxx>
> [Marijn: Rebased over next-20221111]
> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
> ---
>   drivers/iommu/arm/arm-smmu/qcom_iommu.c | 22 +++++++++++++++++++---
>   1 file changed, 19 insertions(+), 3 deletions(-)

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>

--
With best wishes
Dmitry