From 2a2d1382fe9dccfce6f9c60a9c9fd2f0fe5bcf2b Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Tue, 2 Feb 2016 21:46:37 -0800 Subject: 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 Signed-off-by: Michael S. Tsirkin --- include/linux/virtio.h | 23 +++++++++++++++++++++-- include/linux/virtio_ring.h | 35 +++++++++++++++++++++++++++++++++++ 2 files changed, 56 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/virtio.h b/include/linux/virtio.h index 8f4d4bfa6d46..d5eb5479a425 100644 --- a/include/linux/virtio.h +++ b/include/linux/virtio.h @@ -75,8 +75,27 @@ unsigned int virtqueue_get_vring_size(struct virtqueue *vq); bool virtqueue_is_broken(struct virtqueue *vq); -void *virtqueue_get_avail(struct virtqueue *vq); -void *virtqueue_get_used(struct virtqueue *vq); +const struct vring *virtqueue_get_vring(struct virtqueue *vq); +dma_addr_t virtqueue_get_desc_addr(struct virtqueue *vq); +dma_addr_t virtqueue_get_avail_addr(struct virtqueue *vq); +dma_addr_t virtqueue_get_used_addr(struct virtqueue *vq); + +/* + * Legacy accessors -- in almost all cases, these are the wrong functions + * to use. + */ +static inline void *virtqueue_get_desc(struct virtqueue *vq) +{ + return virtqueue_get_vring(vq)->desc; +} +static inline void *virtqueue_get_avail(struct virtqueue *vq) +{ + return virtqueue_get_vring(vq)->avail; +} +static inline void *virtqueue_get_used(struct virtqueue *vq) +{ + return virtqueue_get_vring(vq)->used; +} /** * virtio_device - representation of a device using virtio 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); -- cgit v1.2.3