[PATCH v1 17/20] iommu/s390-iommu: Implement s390_iommu_domain_test_device

Nicolin Chen
2025-10-13T00:06:29Z

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/s390-iommu.c | 22 +++++++++++++++-------
1 file changed, 15 insertions(+), 7 deletions(-)

diff --git a/drivers/iommu/s390-iommu.c b/drivers/iommu/s390-iommu.c
index 366e47978ac07..3c6141a4a1faf 100644
--- a/drivers/iommu/s390-iommu.c
+++ b/drivers/iommu/s390-iommu.c
@@ -694,6 +694,20 @@ static int blocking_domain_attach_device(struct iommu_domain *domain,
return 0;
}

+static int s390_iommu_domain_test_device(struct iommu_domain *domain,
+ struct device *dev, ioasid_t pasid,
+ struct iommu_domain *old)
+{
+ struct zpci_dev *zdev = to_zpci_dev(dev);
+
+ if (!zdev)
+ return -ENODEV;
+ if (WARN_ON(domain->geometry.aperture_start > zdev->end_dma ||
+ domain->geometry.aperture_end < zdev->start_dma))
+ return -EINVAL;
+ return 0;
+}
+
static int s390_iommu_attach_device(struct iommu_domain *domain,
struct device *dev,
struct iommu_domain *old)
@@ -704,13 +718,6 @@ static int s390_iommu_attach_device(struct iommu_domain *domain,
u8 status;
int cc;

- if (!zdev)
- return -ENODEV;
-
- if (WARN_ON(domain->geometry.aperture_start > zdev->end_dma ||
- domain->geometry.aperture_end < zdev->start_dma))
- return -EINVAL;
-
blocking_domain_attach_device(&blocking_domain, dev);

/* If we fail now DMA remains blocked via blocking domain */
@@ -1177,6 +1184,7 @@ static struct iommu_domain blocking_domain = {
.device_group = generic_device_group, \
.get_resv_regions = s390_iommu_get_resv_regions, \
.default_domain_ops = &(const struct iommu_domain_ops) { \
+ .test_dev = s390_iommu_domain_test_device, \
.attach_dev = s390_iommu_attach_device, \
.map_pages = s390_iommu_map_pages, \
.unmap_pages = s390_iommu_unmap_pages, \
--
2.43.0