Re: [Devel] [PATCH v6 3/3] iommu/arm-smmu-v3:Enable ACPI based HiSilicon erratum 161010801

[Will Deacon <will.deacon at arm.com>]

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On Wed, Aug 09, 2017 at 11:07:15AM +0100, Shameer Kolothum wrote:
> The HiSilicon erratum 161010801 describes the limitation of HiSilicon
> platforms Hip06/Hip07 to support the SMMU mappings for MSI transactions.
> 
> On these platforms GICv3 ITS translator is presented with the deviceID
> by extending the MSI payload data to 64 bits to include the deviceID.
> Hence, the PCIe controller on this platforms has to differentiate the
> MSI payload against other DMA payload and has to modify the MSI payload.
> This basically makes it difficult for this platforms to have a SMMU
> translation for MSI.
> 
> This patch implements a ACPI table based quirk to reserve the hw msi
> regions in the smmu-v3 driver which means these address regions will
> not be translated and will be excluded from iova allocations.
> 
> Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi(a)huawei.com>
> ---
>  drivers/iommu/arm-smmu-v3.c | 27 ++++++++++++++++++++++-----
>  1 file changed, 22 insertions(+), 5 deletions(-)

Please can you also add a devicetree binding with corresponding
documentation to enable this workaround on non-ACPI based systems too? It
should be straightforward if you update the arm_smmu_options table.

Thanks,

Will