virtio: add legacy feature table support

[pandora-kernel.git] / drivers / virtio / virtio.c

diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index 3e78f4b..f9ad99c 100644 (file)
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -113,6 +113,13 @@ void virtio_check_driver_offered_feature(const struct virtio_device *vdev,
        for (i = 0; i < drv->feature_table_size; i++)
                if (drv->feature_table[i] == fbit)
                        return;
+
+       if (drv->feature_table_legacy) {
+               for (i = 0; i < drv->feature_table_size_legacy; i++)
+                       if (drv->feature_table_legacy[i] == fbit)
+                               return;
+       }
+
        BUG();
 }
 EXPORT_SYMBOL_GPL(virtio_check_driver_offered_feature);
@@ -161,6 +168,7 @@ static int virtio_dev_probe(struct device *_d)
        struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
        u64 device_features;
        u64 driver_features;
+       u64 driver_features_legacy;
        unsigned status;
 
        /* We have a driver! */
@@ -177,7 +185,22 @@ static int virtio_dev_probe(struct device *_d)
                driver_features |= (1ULL << f);
        }
 
-       dev->features = driver_features & device_features;
+       /* Some drivers have a separate feature table for virtio v1.0 */
+       if (drv->feature_table_legacy) {
+               driver_features_legacy = 0;
+               for (i = 0; i < drv->feature_table_size_legacy; i++) {
+                       unsigned int f = drv->feature_table_legacy[i];
+                       BUG_ON(f >= 64);
+                       driver_features_legacy |= (1ULL << f);
+               }
+       } else {
+               driver_features_legacy = driver_features;
+       }
+
+       if (driver_features & device_features & (1ULL << VIRTIO_F_VERSION_1))
+               dev->features = driver_features & device_features;
+       else
+               dev->features = driver_features_legacy & device_features;
 
        /* Transport features always preserved to pass to finalize_features. */
        for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++)