Merge branch 'topic/ice' into for-linus

[pandora-kernel.git] / include / linux / virtio.h

diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index 260d1fc..06005fa 100644 (file)
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -41,13 +41,17 @@ struct virtqueue
  *     Returns NULL or the "data" token handed to add_buf.
  * @disable_cb: disable callbacks
  *     vq: the struct virtqueue we're talking about.
+ *     Note that this is not necessarily synchronous, hence unreliable and only
+ *     useful as an optimization.
  * @enable_cb: restart callbacks after disable_cb.
  *     vq: the struct virtqueue we're talking about.
- *     This returns "false" (and doesn't re-enable) if there are pending
- *     buffers in the queue, to avoid a race.
+ *     This re-enables callbacks; it returns "false" if there are pending
+ *     buffers in the queue, to detect a possible race between the driver
+ *     checking for more work, and enabling callbacks.
  *
  * Locking rules are straightforward: the driver is responsible for
- * locking.  No two operations may be invoked simultaneously.
+ * locking.  No two operations may be invoked simultaneously, with the exception
+ * of @disable_cb.
  *
  * All operations can be called in any context.
  */
@@ -72,6 +76,7 @@ struct virtqueue_ops {
  * @dev: underlying device.
  * @id: the device type identification (used to match it with a driver).
  * @config: the configuration ops for this device.
+ * @features: the features supported by both driver and device.
  * @priv: private pointer for the driver's use.
  */
 struct virtio_device
@@ -80,6 +85,8 @@ struct virtio_device
        struct device dev;
        struct virtio_device_id id;
        struct virtio_config_ops *config;
+       /* Note that this is a Linux set_bit-style bitmap. */
+       unsigned long features[1];
        void *priv;
 };
 
@@ -90,6 +97,8 @@ void unregister_virtio_device(struct virtio_device *dev);
  * virtio_driver - operations for a virtio I/O driver
  * @driver: underlying device driver (populate name and owner).
  * @id_table: the ids serviced by this driver.
+ * @feature_table: an array of feature numbers supported by this device.
+ * @feature_table_size: number of entries in the feature table array.
  * @probe: the function to call when a device is found.  Returns a token for
  *    remove, or PTR_ERR().
  * @remove: the function when a device is removed.
@@ -99,6 +108,8 @@ void unregister_virtio_device(struct virtio_device *dev);
 struct virtio_driver {
        struct device_driver driver;
        const struct virtio_device_id *id_table;
+       const unsigned int *feature_table;
+       unsigned int feature_table_size;
        int (*probe)(struct virtio_device *dev);
        void (*remove)(struct virtio_device *dev);
        void (*config_changed)(struct virtio_device *dev);