md: Turn rdev->sb_offset into a sector-based quantity.

[linux-2.6-omap-h63xx.git] / include / linux / virtio.h

diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index 14e1379876d334f9bb99d04d43750c571c967528..06005fa9e982e0f703a7eef56f4108378c566f24 100644 (file)
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -11,15 +11,13 @@
 /**
  * virtqueue - a queue to register buffers for sending or receiving.
  * @callback: the function to call when buffers are consumed (can be NULL).
- *    If this returns false, callbacks are suppressed until vq_ops->restart
- *    is called.
  * @vdev: the virtio device this queue was created for.
  * @vq_ops: the operations for this virtqueue (see below).
  * @priv: a pointer for the virtqueue implementation to use.
  */
 struct virtqueue
 {
-       bool (*callback)(struct virtqueue *vq);
+       void (*callback)(struct virtqueue *vq);
        struct virtio_device *vdev;
        struct virtqueue_ops *vq_ops;
        void *priv;
@@ -41,16 +39,19 @@ struct virtqueue
  *     vq: the struct virtqueue we're talking about.
  *     len: the length written into the buffer
  *     Returns NULL or the "data" token handed to add_buf.
- * @restart: restart callbacks after callback returned false.
+ * @disable_cb: disable callbacks
  *     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.
- * @shutdown: "unadd" all buffers.
+ *     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.
- *     Remove everything from the queue.
+ *     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.
  */
@@ -65,9 +66,8 @@ struct virtqueue_ops {
 
        void *(*get_buf)(struct virtqueue *vq, unsigned int *len);
 
-       bool (*restart)(struct virtqueue *vq);
-
-       void (*shutdown)(struct virtqueue *vq);
+       void (*disable_cb)(struct virtqueue *vq);
+       bool (*enable_cb)(struct virtqueue *vq);
 };
 
 /**
@@ -76,6 +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
@@ -84,6 +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;
 };
 
@@ -94,15 +97,22 @@ 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.
+ * @config_changed: optional function to call when the device configuration
+ *    changes; may be called in interrupt context.
  */
 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);
 };
 
 int register_virtio_driver(struct virtio_driver *drv);