[RFC PATCH 1/4] Add a new API to virtio-pci

[Krishna Kumar <krkumar2@in.ibm.com>]

Add virtio_get_queue_index() to get the queue index of a
vq.  This is needed by the cb handler to locate the queue
that should be processed.

Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com>
---
 drivers/virtio/virtio_pci.c |    9 +++++++++
 include/linux/virtio.h      |    3 +++
 2 files changed, 12 insertions(+)

diff -ruNp org/include/linux/virtio.h tx_only/include/linux/virtio.h
--- org/include/linux/virtio.h	2010-09-03 16:33:51.000000000 +0530
+++ tx_only/include/linux/virtio.h	2010-09-08 10:23:36.000000000 +0530
@@ -136,4 +136,7 @@ struct virtio_driver {
 
 int register_virtio_driver(struct virtio_driver *drv);
 void unregister_virtio_driver(struct virtio_driver *drv);
+
+/* return the internal queue index associated with the virtqueue */
+extern int virtio_get_queue_index(struct virtqueue *vq);
 #endif /* _LINUX_VIRTIO_H */
diff -ruNp org/drivers/virtio/virtio_pci.c tx_only/drivers/virtio/virtio_pci.c
--- org/drivers/virtio/virtio_pci.c	2010-09-03 16:33:51.000000000 +0530
+++ tx_only/drivers/virtio/virtio_pci.c	2010-09-08 10:23:16.000000000 +0530
@@ -359,6 +359,15 @@ static int vp_request_intx(struct virtio
 	return err;
 }
 
+/* Return the internal queue index associated with the virtqueue */
+int virtio_get_queue_index(struct virtqueue *vq)
+{
+	struct virtio_pci_vq_info *info = vq->priv;
+
+	return info->queue_index;
+}
+EXPORT_SYMBOL(virtio_get_queue_index);
+
 static struct virtqueue *setup_vq(struct virtio_device *vdev, unsigned index,
 				  void (*callback)(struct virtqueue *vq),
 				  const char *name,