[PATCH v6 02/14] iommufd/fault: Add an iommufd_fault_init() helper

[Nicolin Chen <nicolinc@nvidia.com>]

The infrastructure of a fault object will be shared with a new vEVENTQ
object in a following change. Add an iommufd_fault_init helper and an
INIT_EVENTQ_FOPS marco for a vEVENTQ allocator to use too.

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

Since the new vEVENTQ doesn't need "response" and its "mutex", so keep
the xa_init_flags and mutex_init in their original locations.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
---
 drivers/iommu/iommufd/fault.c | 70 +++++++++++++++++++++--------------
 1 file changed, 42 insertions(+), 28 deletions(-)

diff --git a/drivers/iommu/iommufd/fault.c b/drivers/iommu/iommufd/fault.c
index e89d27bb9548..08d940204169 100644
--- a/drivers/iommu/iommufd/fault.c
+++ b/drivers/iommu/iommufd/fault.c
@@ -400,20 +400,49 @@ static int iommufd_fault_fops_release(struct inode *inode, struct file *filep)
 	return 0;
 }
 
-static const struct file_operations iommufd_fault_fops = {
-	.owner		= THIS_MODULE,
-	.open		= nonseekable_open,
-	.read		= iommufd_fault_fops_read,
-	.write		= iommufd_fault_fops_write,
-	.poll		= iommufd_fault_fops_poll,
-	.release	= iommufd_fault_fops_release,
-};
+#define INIT_FAULT_FOPS(read_op, write_op)                                     \
+	((const struct file_operations){                                       \
+		.owner = THIS_MODULE,                                          \
+		.open = nonseekable_open,                                      \
+		.read = read_op,                                               \
+		.write = write_op,                                             \
+		.poll = iommufd_fault_fops_poll,                               \
+		.release = iommufd_fault_fops_release,                         \
+	})
+
+static int iommufd_fault_init(struct iommufd_fault *fault, char *name,
+			      struct iommufd_ctx *ictx,
+			      const struct file_operations *fops)
+{
+	struct file *filep;
+	int fdno;
+
+	spin_lock_init(&fault->lock);
+	INIT_LIST_HEAD(&fault->deliver);
+	init_waitqueue_head(&fault->wait_queue);
+
+	filep = anon_inode_getfile(name, 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;
+}
+
+static const struct file_operations iommufd_fault_fops =
+	INIT_FAULT_FOPS(iommufd_fault_fops_read, iommufd_fault_fops_write);
 
 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;
 
@@ -424,28 +453,14 @@ 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);
-	spin_lock_init(&fault->lock);
-	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,
+				  &iommufd_fault_fops);
 	if (fdno < 0) {
 		rc = fdno;
-		goto out_fput;
+		goto out_abort;
 	}
 
 	cmd->out_fault_id = fault->obj.id;
@@ -461,8 +476,7 @@ 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