[RFC PATCH 03/10] vdpa: add vdpa_set_config() helper

[Stefano Garzarella]

Let's add a function similar to vpda_get_config() to check the
'offset' and 'len' parameters, call the set_config() device callback,
and return the amount of bytes written.

Signed-off-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>
---
 include/linux/vdpa.h |  2 ++
 drivers/vdpa/vdpa.c  | 16 ++++++++++++++++
 2 files changed, 18 insertions(+)

diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
index 8a679c98f8b1..562fcd14f4b5 100644
--- a/include/linux/vdpa.h
+++ b/include/linux/vdpa.h
@@ -334,6 +334,8 @@ static inline int vdpa_set_features(struct vdpa_device *vdev, u64 features)
 
 int vdpa_get_config(struct vdpa_device *vdev, unsigned int offset,
 		    void *buf, unsigned int len);
+int vdpa_set_config(struct vdpa_device *vdev, unsigned int offset,
+		    const void *buf, unsigned int len);
 
 /**
  * vdpa_mgmtdev_ops - vdpa device ops
diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
index 9ed6c779c63c..825afc690a7e 100644
--- a/drivers/vdpa/vdpa.c
+++ b/drivers/vdpa/vdpa.c
@@ -86,6 +86,22 @@ int vdpa_get_config(struct vdpa_device *vdev, unsigned int offset,
 }
 EXPORT_SYMBOL_GPL(vdpa_get_config);
 
+int vdpa_set_config(struct vdpa_device *vdev, unsigned int offset,
+		    const void *buf, unsigned int len)
+{
+	const struct vdpa_config_ops *ops = vdev->config;
+	int bytes_set;
+
+	bytes_set = vdpa_config_size_wrap(vdev, offset, len);
+	if (bytes_set <= 0)
+		return bytes_set;
+
+	ops->set_config(vdev, offset, buf, bytes_set);
+
+	return bytes_set;
+}
+EXPORT_SYMBOL_GPL(vdpa_set_config);
+
 static void vdpa_release_dev(struct device *d)
 {
 	struct vdpa_device *vdev = dev_to_vdpa(d);
-- 
2.29.2