[PATCH 2/4] vfio: Add vfio_device_get()

[Jason Gunthorpe]

To increment a reference the caller already holds. Export
vfio_device_put() to pair with it.

Signed-off-by: Jason Gunthorpe <jgg at nvidia.com>
---
 drivers/vfio/vfio_main.c | 3 ++-
 include/linux/vfio.h     | 6 ++++++
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
index 6f96e6d07a5e98..5ad50aec7dc94c 100644
--- a/drivers/vfio/vfio_main.c
+++ b/drivers/vfio/vfio_main.c
@@ -451,11 +451,12 @@ static void vfio_group_get(struct vfio_group *group)
  * Device objects - create, release, get, put, search
  */
 /* Device reference always implies a group reference */
-static void vfio_device_put(struct vfio_device *device)
+void vfio_device_put(struct vfio_device *device)
 {
 	if (refcount_dec_and_test(&device->refcount))
 		complete(&device->comp);
 }
+EXPORT_SYMBOL_GPL(vfio_device_put);
 
 static bool vfio_device_try_get(struct vfio_device *device)
 {
diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index e05ddc6fe6a556..25850b1e08cba9 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -143,6 +143,12 @@ void vfio_uninit_group_dev(struct vfio_device *device);
 int vfio_register_group_dev(struct vfio_device *device);
 int vfio_register_emulated_iommu_dev(struct vfio_device *device);
 void vfio_unregister_group_dev(struct vfio_device *device);
+void vfio_device_put(struct vfio_device *device);
+
+static inline void vfio_device_get(struct vfio_device *device)
+{
+	refcount_inc(&device->refcount);
+}
 
 int vfio_assign_device_set(struct vfio_device *device, void *set_id);
 
-- 
2.37.2