[RFC 5/8] iommufd/selftest: Add a helper to get test device

[Yi Liu <yi.l.liu@intel.com>]

There is need to get the selftest device (sobj->type == TYPE_IDEV) in
multiple places, so have a helper to for it.

Signed-off-by: Yi Liu <yi.l.liu@intel.com>
---
 drivers/iommu/iommufd/selftest.c | 32 +++++++++++++++++++++-----------
 1 file changed, 21 insertions(+), 11 deletions(-)

diff --git a/drivers/iommu/iommufd/selftest.c b/drivers/iommu/iommufd/selftest.c
index 200c88387cd1..1f2ce4ffee4e 100644
--- a/drivers/iommu/iommufd/selftest.c
+++ b/drivers/iommu/iommufd/selftest.c
@@ -668,29 +668,39 @@ static int iommufd_test_mock_domain(struct iommufd_ucmd *ucmd,
 	return rc;
 }
 
-/* Replace the mock domain with a manually allocated hw_pagetable */
-static int iommufd_test_mock_domain_replace(struct iommufd_ucmd *ucmd,
-					    unsigned int device_id, u32 pt_id,
-					    struct iommu_test_cmd *cmd)
+static struct selftest_obj *
+iommufd_test_get_self_test_device(struct iommufd_ctx *ictx, u32 id)
 {
 	struct iommufd_object *dev_obj;
 	struct selftest_obj *sobj;
-	int rc;
 
 	/*
 	 * Prefer to use the OBJ_SELFTEST because the destroy_rwsem will ensure
 	 * it doesn't race with detach, which is not allowed.
 	 */
-	dev_obj =
-		iommufd_get_object(ucmd->ictx, device_id, IOMMUFD_OBJ_SELFTEST);
+	dev_obj = iommufd_get_object(ictx, id, IOMMUFD_OBJ_SELFTEST);
 	if (IS_ERR(dev_obj))
-		return PTR_ERR(dev_obj);
+		return (struct selftest_obj *)dev_obj;
 
 	sobj = container_of(dev_obj, struct selftest_obj, obj);
 	if (sobj->type != TYPE_IDEV) {
-		rc = -EINVAL;
-		goto out_dev_obj;
+		iommufd_put_object(dev_obj);
+		return ERR_PTR(-EINVAL);
 	}
+	return sobj;
+}
+
+/* Replace the mock domain with a manually allocated hw_pagetable */
+static int iommufd_test_mock_domain_replace(struct iommufd_ucmd *ucmd,
+					    unsigned int device_id, u32 pt_id,
+					    struct iommu_test_cmd *cmd)
+{
+	struct selftest_obj *sobj;
+	int rc;
+
+	sobj = iommufd_test_get_self_test_device(ucmd->ictx, device_id);
+	if (IS_ERR(sobj))
+		return PTR_ERR(sobj);
 
 	rc = iommufd_device_replace(sobj->idev.idev, &pt_id);
 	if (rc)
@@ -700,7 +710,7 @@ static int iommufd_test_mock_domain_replace(struct iommufd_ucmd *ucmd,
 	rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd));
 
 out_dev_obj:
-	iommufd_put_object(dev_obj);
+	iommufd_put_object(&sobj->obj);
 	return rc;
 }
 
-- 
2.34.1