[PATCH AUTOSEL 5.15 10/47] iommu/arm-smmu-v3: Make default domain type of HiSilicon PTT device to identity

Sasha Levin
2022-10-13T01:13:27Z

From: Yicong Yang <yangyicong@hisilicon.com>

[ 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@kernel.org>
Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Reviewed-by: John Garry <john.garry@huawei.com>
Link: https://lore.kernel.org/r/20220816114414.4092-2-yangyicong@huawei.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 79edfdca6607..e7da4a47ce52 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -2832,6 +2832,26 @@ 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,
@@ -2857,6 +2877,7 @@ 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,
};
--
2.35.1