[PATCH v3 02/14] iommufd/fault: Add an iommufd_fault_init() helper

[Nicolin Chen <nicolinc@xxxxxxxxxx>]

The infrastructure of a fault object will be shared with a new vIRQ object
in a following change. Add a helper for a vIRQ allocator to call it too.

Reorder the iommufd_ctx_get and refcount_inc to keep them symmetrical with
the iommufd_fault_fops_release().

Since the new vIRQ object doesn't need "response", leave the xa_init_flags
in its original location.

Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>
Signed-off-by: Nicolin Chen <nicolinc@xxxxxxxxxx>
---
 drivers/iommu/iommufd/fault.c | 48 ++++++++++++++++++++---------------
 1 file changed, 28 insertions(+), 20 deletions(-)

diff --git a/drivers/iommu/iommufd/fault.c b/drivers/iommu/iommufd/fault.c
index 1fe804e28a86..1d1095fc8224 100644
--- a/drivers/iommu/iommufd/fault.c
+++ b/drivers/iommu/iommufd/fault.c
@@ -367,11 +367,35 @@ static const struct file_operations iommufd_fault_fops = {
 	.release	= iommufd_fault_fops_release,
 };
 
+static int iommufd_fault_init(struct iommufd_fault *fault, char *name,
+			      struct iommufd_ctx *ictx)
+{
+	struct file *filep;
+	int fdno;
+
+	mutex_init(&fault->mutex);
+	INIT_LIST_HEAD(&fault->deliver);
+	init_waitqueue_head(&fault->wait_queue);
+
+	filep = anon_inode_getfile(name, &iommufd_fault_fops, fault, O_RDWR);
+	if (IS_ERR(filep))
+		return PTR_ERR(filep);
+
+	fault->ictx = ictx;
+	iommufd_ctx_get(fault->ictx);
+	fault->filep = filep;
+	refcount_inc(&fault->obj.users);
+
+	fdno = get_unused_fd_flags(O_CLOEXEC);
+	if (fdno < 0)
+		fput(filep);
+	return fdno;
+}
+
 int iommufd_fault_alloc(struct iommufd_ucmd *ucmd)
 {
 	struct iommu_fault_alloc *cmd = ucmd->cmd;
 	struct iommufd_fault *fault;
-	struct file *filep;
 	int fdno;
 	int rc;
 
@@ -382,27 +406,12 @@ int iommufd_fault_alloc(struct iommufd_ucmd *ucmd)
 	if (IS_ERR(fault))
 		return PTR_ERR(fault);
 
-	fault->ictx = ucmd->ictx;
-	INIT_LIST_HEAD(&fault->deliver);
 	xa_init_flags(&fault->response, XA_FLAGS_ALLOC1);
-	mutex_init(&fault->mutex);
-	init_waitqueue_head(&fault->wait_queue);
-
-	filep = anon_inode_getfile("[iommufd-pgfault]", &iommufd_fault_fops,
-				   fault, O_RDWR);
-	if (IS_ERR(filep)) {
-		rc = PTR_ERR(filep);
-		goto out_abort;
-	}
 
-	refcount_inc(&fault->obj.users);
-	iommufd_ctx_get(fault->ictx);
-	fault->filep = filep;
-
-	fdno = get_unused_fd_flags(O_CLOEXEC);
+	fdno = iommufd_fault_init(fault, "[iommufd-pgfault]", ucmd->ictx);
 	if (fdno < 0) {
 		rc = fdno;
-		goto out_fput;
+		goto out_abort;
 	}
 
 	cmd->out_fault_id = fault->obj.id;
@@ -418,8 +427,7 @@ int iommufd_fault_alloc(struct iommufd_ucmd *ucmd)
 	return 0;
 out_put_fdno:
 	put_unused_fd(fdno);
-out_fput:
-	fput(filep);
+	fput(fault->filep);
 out_abort:
 	iommufd_object_abort_and_destroy(ucmd->ictx, &fault->obj);
 
-- 
2.43.0