From: Yicong Yang <yangyicong@xxxxxxxxxxxxx> [ Upstream commit 24b6c7798a0122012ca848ea0d25e973334266b0 ] The DMA operations of HiSilicon PTT device can only work properly with identical mappings. So add a quirk for the device to force the domain as passthrough. Acked-by: Will Deacon <will@xxxxxxxxxx> Signed-off-by: Yicong Yang <yangyicong@xxxxxxxxxxxxx> Reviewed-by: John Garry <john.garry@xxxxxxxxxx> Link: https://lore.kernel.org/r/20220816114414.4092-2-yangyicong@xxxxxxxxxx Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 21 +++++++++++++++++++++ 1 file changed, 21 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 d32b02336411..71f7edded9cf 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c @@ -2817,6 +2817,26 @@ static int arm_smmu_dev_disable_feature(struct device *dev, } } +/* + * HiSilicon PCIe tune and trace device can be used to trace TLP headers on the + * PCIe link and save the data to memory by DMA. The hardware is restricted to + * use identity mapping only. + */ +#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, @@ -2831,6 +2851,7 @@ 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, .default_domain_ops = &(const struct iommu_domain_ops) { -- 2.35.1
