virtio: add names to virtqueue struct, mapping from devices to queues.

Add a linked list of all virtqueues for a virtio device: this helps for
debugging and is also needed for upcoming interface change.

Also, add a "name" field for clearer debug messages.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

3 files changed, 14 insertions, 7 deletions

diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index 9410394bbf96..4fca4f5440ba 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -10,14 +10,17 @@
 
 /**
  * virtqueue - a queue to register buffers for sending or receiving.
+ * @list: the chain of virtqueues for this device
  * @callback: the function to call when buffers are consumed (can be NULL).
+ * @name: the name of this virtqueue (mainly for debugging)
  * @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
-{
+struct virtqueue {
+        struct list_head list;
         void (*callback)(struct virtqueue *vq);
+        const char *name;
         struct virtio_device *vdev;
         struct virtqueue_ops *vq_ops;
         void *priv;
@@ -76,15 +79,16 @@ 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.
+ * @vqs: the list of virtqueues for this device.
  * @features: the features supported by both driver and device.
  * @priv: private pointer for the driver's use.
  */
-struct virtio_device
-{
+struct virtio_device {
         int index;
         struct device dev;
         struct virtio_device_id id;
         struct virtio_config_ops *config;
+        struct list_head vqs;
         /* Note that this is a Linux set_bit-style bitmap. */
         unsigned long features[1];
         void *priv;
diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
index bf8ec283b232..9fae274751e0 100644
--- a/include/linux/virtio_config.h
+++ b/include/linux/virtio_config.h
@@ -55,7 +55,8 @@
  * @find_vq: find a virtqueue and instantiate it.
  *      vdev: the virtio_device
  *      index: the 0-based virtqueue number in case there's more than one.
- *      callback: the virqtueue callback
+ *      callback: the virtqueue callback
+ *      name: the virtqueue name (mainly for debugging)
  *      Returns the new virtqueue or ERR_PTR() (eg. -ENOENT).
  * @del_vq: free a virtqueue found by find_vq().
  * @get_features: get the array of feature bits for this device.
@@ -77,7 +78,8 @@ struct virtio_config_ops
         void (*reset)(struct virtio_device *vdev);
         struct virtqueue *(*find_vq)(struct virtio_device *vdev,
                                      unsigned index,
-                                     void (*callback)(struct virtqueue *));
+                                     void (*callback)(struct virtqueue *),
+                                     const char *name);
         void (*del_vq)(struct virtqueue *vq);
         u32 (*get_features)(struct virtio_device *vdev);
         void (*finalize_features)(struct virtio_device *vdev);
diff --git a/include/linux/virtio_ring.h b/include/linux/virtio_ring.h
index 71e03722fb59..166c519689de 100644
--- a/include/linux/virtio_ring.h
+++ b/include/linux/virtio_ring.h
@@ -119,7 +119,8 @@ struct virtqueue *vring_new_virtqueue(unsigned int num,
                                       struct virtio_device *vdev,
                                       void *pages,
                                       void (*notify)(struct virtqueue *vq),
-                                      void (*callback)(struct virtqueue *vq));
+                                      void (*callback)(struct virtqueue *vq),
+                                      const char *name);
 void vring_del_virtqueue(struct virtqueue *vq);
 /* Filter out transport-specific feature bits. */
 void vring_transport_features(struct virtio_device *vdev);