From: Yicong Yang <yangyicong@xxxxxxxxxxxxx>
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>
---
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 88817a3376ef..e119ff8396c9 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -2839,6 +2839,26 @@ 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,
@@ -2856,6 +2876,7 @@ 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) {
--
2.24.0
