virtio: add drv_to_virtio to make code clearly

Add drv_to_virtio wrapper to get virtio_driver from device_driver.

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Signed-off-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index 1346ae8..1c01ac3 100644 (file)
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -73,7 +73,7 @@ static int virtio_dev_match(struct device *_dv, struct device_driver *_dr)
        struct virtio_device *dev = dev_to_virtio(_dv);
        const struct virtio_device_id *ids;
 
-       ids = container_of(_dr, struct virtio_driver, driver)->id_table;
+       ids = drv_to_virtio(_dr)->id_table;
        for (i = 0; ids[i].device; i++)
                if (virtio_id_match(dev, &ids[i]))
                        return 1;
@@ -97,8 +97,7 @@ void virtio_check_driver_offered_feature(const struct virtio_device *vdev,
                                         unsigned int fbit)
 {
        unsigned int i;
-       struct virtio_driver *drv = container_of(vdev->dev.driver,
-                                                struct virtio_driver, driver);
+       struct virtio_driver *drv = drv_to_virtio(vdev->dev.driver);
 
        for (i = 0; i < drv->feature_table_size; i++)
                if (drv->feature_table[i] == fbit)
@@ -111,8 +110,7 @@ static int virtio_dev_probe(struct device *_d)
 {
        int err, i;
        struct virtio_device *dev = dev_to_virtio(_d);
-       struct virtio_driver *drv = container_of(dev->dev.driver,
-                                                struct virtio_driver, driver);
+       struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
        u32 device_features;
 
        /* We have a driver! */
@@ -152,8 +150,7 @@ static int virtio_dev_probe(struct device *_d)
 static int virtio_dev_remove(struct device *_d)
 {
        struct virtio_device *dev = dev_to_virtio(_d);
-       struct virtio_driver *drv = container_of(dev->dev.driver,
-                                                struct virtio_driver, driver);
+       struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
 
        drv->remove(dev);
 

diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index 5f1f80c..cf8adb1 100644 (file)
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -119,6 +119,11 @@ struct virtio_driver {
 #endif
 };
 
+static inline struct virtio_driver *drv_to_virtio(struct device_driver *drv)
+{
+       return container_of(drv, struct virtio_driver, driver);
+}
+
 int register_virtio_driver(struct virtio_driver *drv);
 void unregister_virtio_driver(struct virtio_driver *drv);
 #endif /* _LINUX_VIRTIO_H */