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authorAndy Lutomirski <luto@kernel.org>2016-02-02 21:46:37 -0800
committerMichael S. Tsirkin <mst@redhat.com>2016-03-02 17:01:57 +0200
commit2a2d1382fe9dccfce6f9c60a9c9fd2f0fe5bcf2b (patch)
treeab3783be11369f689e3e7aebe0c438ab6746375f /include/linux/virtio_ring.h
parent780bc7903a32edb63be138487fd981694d993610 (diff)
virtio: Add improved queue allocation API
This leaves vring_new_virtqueue alone for compatbility, but it adds two new improved APIs: vring_create_virtqueue: Creates a virtqueue backed by automatically allocated coherent memory. (Some day it this could be extended to support non-coherent memory, too, if there ends up being a platform on which it's worthwhile.) __vring_new_virtqueue: Creates a virtqueue with a manually-specified layout. This should allow mic_virtio to work much more cleanly. Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'include/linux/virtio_ring.h')
-rw-r--r--include/linux/virtio_ring.h35
1 files changed, 35 insertions, 0 deletions
diff --git a/include/linux/virtio_ring.h b/include/linux/virtio_ring.h
index a156e2b6ccfe..e8d36938f09a 100644
--- a/include/linux/virtio_ring.h
+++ b/include/linux/virtio_ring.h
@@ -59,6 +59,35 @@ static inline void virtio_store_mb(bool weak_barriers,
struct virtio_device;
struct virtqueue;
+/*
+ * Creates a virtqueue and allocates the descriptor ring. If
+ * may_reduce_num is set, then this may allocate a smaller ring than
+ * expected. The caller should query virtqueue_get_ring_size to learn
+ * the actual size of the ring.
+ */
+struct virtqueue *vring_create_virtqueue(unsigned int index,
+ unsigned int num,
+ unsigned int vring_align,
+ struct virtio_device *vdev,
+ bool weak_barriers,
+ bool may_reduce_num,
+ bool (*notify)(struct virtqueue *vq),
+ void (*callback)(struct virtqueue *vq),
+ const char *name);
+
+/* Creates a virtqueue with a custom layout. */
+struct virtqueue *__vring_new_virtqueue(unsigned int index,
+ struct vring vring,
+ struct virtio_device *vdev,
+ bool weak_barriers,
+ bool (*notify)(struct virtqueue *),
+ void (*callback)(struct virtqueue *),
+ const char *name);
+
+/*
+ * Creates a virtqueue with a standard layout but a caller-allocated
+ * ring.
+ */
struct virtqueue *vring_new_virtqueue(unsigned int index,
unsigned int num,
unsigned int vring_align,
@@ -68,7 +97,13 @@ struct virtqueue *vring_new_virtqueue(unsigned int index,
bool (*notify)(struct virtqueue *vq),
void (*callback)(struct virtqueue *vq),
const char *name);
+
+/*
+ * Destroys a virtqueue. If created with vring_create_virtqueue, this
+ * also frees the ring.
+ */
void vring_del_virtqueue(struct virtqueue *vq);
+
/* Filter out transport-specific feature bits. */
void vring_transport_features(struct virtio_device *vdev);