Hi Robin,
Is this quirk ok with the SMMU v3 driver? Just want to confirm that I'm on the
right way to dealing with the issue of our device.
Thanks.
On 2022/1/24 21:11, Yicong Yang wrote:
> The DMA of HiSilicon PTT device can only work with identical
> mapping. So add a quirk for the device to force the domain
> passthrough.
>
> Signed-off-by: Yicong Yang <yangyicong@xxxxxxxxxxxxx>
> ---
> drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 16 ++++++++++++++++
> 1 file changed, 16 insertions(+)
>
> diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> index 6dc6d8b6b368..6f67a2b1dd27 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> @@ -2838,6 +2838,21 @@ static int arm_smmu_dev_disable_feature(struct device *dev,
> }
> }
>
> +#define IS_HISI_PTT_DEVICE(pdev) ((pdev)->vendor == PCI_VENDOR_ID_HUAWEI && \
> + (pdev)->device == 0xa12e)
> +
> +static int arm_smmu_def_domain_type(struct device *dev)
> +{
> + if (dev_is_pci(dev)) {
> + struct pci_dev *pdev = to_pci_dev(dev);
> +
> + if (IS_HISI_PTT_DEVICE(pdev))
> + return IOMMU_DOMAIN_IDENTITY;
> + }
> +
> + return 0;
> +}
> +
> static struct iommu_ops arm_smmu_ops = {
> .capable = arm_smmu_capable,
> .domain_alloc = arm_smmu_domain_alloc,
> @@ -2863,6 +2878,7 @@ static struct iommu_ops arm_smmu_ops = {
> .sva_unbind = arm_smmu_sva_unbind,
> .sva_get_pasid = arm_smmu_sva_get_pasid,
> .page_response = arm_smmu_page_response,
> + .def_domain_type = arm_smmu_def_domain_type,
> .pgsize_bitmap = -1UL, /* Restricted during device attach */
> .owner = THIS_MODULE,
> };
>
