[PATCH v1 08/20] iommu/riscv: Implement riscv_iommu_test_paging_domain

Nicolin Chen
2025-10-13T00:07:54Z

Move sanity and compatibility tests from the attach_dev callback to the
new test_dev callback function. The IOMMU core makes sure an attach_dev
call must be invoked after a successful test_dev call.

Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
---
drivers/iommu/riscv/iommu.c | 16 +++++++++++++---
1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/iommu/riscv/iommu.c b/drivers/iommu/riscv/iommu.c
index d9429097a2b51..6613ece2c9f41 100644
--- a/drivers/iommu/riscv/iommu.c
+++ b/drivers/iommu/riscv/iommu.c
@@ -1320,6 +1320,18 @@ static bool riscv_iommu_pt_supported(struct riscv_iommu_device *iommu, int pgd_m
return false;
}

+static int riscv_iommu_test_paging_domain(struct iommu_domain *iommu_domain,
+ struct device *dev, ioasid_t pasid,
+ struct iommu_domain *old)
+{
+ struct riscv_iommu_domain *domain = iommu_domain_to_riscv(iommu_domain);
+ struct riscv_iommu_device *iommu = dev_to_iommu(dev);
+
+ if (!riscv_iommu_pt_supported(iommu, domain->pgd_mode))
+ return -ENODEV;
+ return 0;
+}
+
static int riscv_iommu_attach_paging_domain(struct iommu_domain *iommu_domain,
struct device *dev,
struct iommu_domain *old)
@@ -1329,9 +1341,6 @@ static int riscv_iommu_attach_paging_domain(struct iommu_domain *iommu_domain,
struct riscv_iommu_info *info = dev_iommu_priv_get(dev);
u64 fsc, ta;

- if (!riscv_iommu_pt_supported(iommu, domain->pgd_mode))
- return -ENODEV;
-
fsc = FIELD_PREP(RISCV_IOMMU_PC_FSC_MODE, domain->pgd_mode) |
FIELD_PREP(RISCV_IOMMU_PC_FSC_PPN, virt_to_pfn(domain->pgd_root));
ta = FIELD_PREP(RISCV_IOMMU_PC_TA_PSCID, domain->pscid) |
@@ -1348,6 +1357,7 @@ static int riscv_iommu_attach_paging_domain(struct iommu_domain *iommu_domain,
}

static const struct iommu_domain_ops riscv_iommu_paging_domain_ops = {
+ .test_dev = riscv_iommu_test_paging_domain,
.attach_dev = riscv_iommu_attach_paging_domain,
.free = riscv_iommu_free_paging_domain,
.map_pages = riscv_iommu_map_pages,
--
2.43.0