virtio: simplify feature bit handling

Now that we use u64 for bits, we can simply & them together.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>

diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index 9248125..3e78f4b 100644 (file)
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -160,6 +160,7 @@ static int virtio_dev_probe(struct device *_d)
        struct virtio_device *dev = dev_to_virtio(_d);
        struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
        u64 device_features;
+       u64 driver_features;
        unsigned status;
 
        /* We have a driver! */
@@ -168,15 +169,16 @@ static int virtio_dev_probe(struct device *_d)
        /* Figure out what features the device supports. */
        device_features = dev->config->get_features(dev);
 
-       /* Features supported by both device and driver into dev->features. */
-       dev->features = 0;
+       /* Figure out what features the driver supports. */
+       driver_features = 0;
        for (i = 0; i < drv->feature_table_size; i++) {
                unsigned int f = drv->feature_table[i];
                BUG_ON(f >= 64);
-               if (device_features & (1ULL << f))
-                       __virtio_set_bit(dev, f);
+               driver_features |= (1ULL << f);
        }
 
+       dev->features = driver_features & device_features;
+
        /* Transport features always preserved to pass to finalize_features. */
        for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++)
                if (device_features & (1ULL << i))