Move the logic for attaching a descriptor to its own function.
Signed-off-by: Andrew Scull ascull@google.com Reviewed-by: Simon Glass sjg@chromium.org --- drivers/virtio/virtio_ring.c | 36 +++++++++++++++++------------------- 1 file changed, 17 insertions(+), 19 deletions(-)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index a6922ce1b8..d3fc842f30 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -16,6 +16,18 @@ #include <linux/bug.h> #include <linux/compat.h>
+static unsigned int virtqueue_attach_desc(struct virtqueue *vq, unsigned int i, + struct virtio_sg *sg, u16 flags) +{ + struct vring_desc *desc = &vq->vring.desc[i]; + + desc->addr = cpu_to_virtio64(vq->vdev, (u64)(uintptr_t)sg->addr); + desc->len = cpu_to_virtio32(vq->vdev, sg->length); + desc->flags = cpu_to_virtio16(vq->vdev, flags); + + return virtio16_to_cpu(vq->vdev, desc->next); +} + int virtqueue_add(struct virtqueue *vq, struct virtio_sg *sgs[], unsigned int out_sgs, unsigned int in_sgs) { @@ -44,27 +56,13 @@ int virtqueue_add(struct virtqueue *vq, struct virtio_sg *sgs[], return -ENOSPC; }
- for (n = 0; n < out_sgs; n++) { - struct virtio_sg *sg = sgs[n]; - - desc[i].flags = cpu_to_virtio16(vq->vdev, VRING_DESC_F_NEXT); - desc[i].addr = cpu_to_virtio64(vq->vdev, (u64)(size_t)sg->addr); - desc[i].len = cpu_to_virtio32(vq->vdev, sg->length); - - prev = i; - i = virtio16_to_cpu(vq->vdev, desc[i].next); - } - for (; n < (out_sgs + in_sgs); n++) { - struct virtio_sg *sg = sgs[n]; - - desc[i].flags = cpu_to_virtio16(vq->vdev, VRING_DESC_F_NEXT | - VRING_DESC_F_WRITE); - desc[i].addr = cpu_to_virtio64(vq->vdev, - (u64)(uintptr_t)sg->addr); - desc[i].len = cpu_to_virtio32(vq->vdev, sg->length); + for (n = 0; n < descs_used; n++) { + u16 flags = VRING_DESC_F_NEXT;
+ if (n >= out_sgs) + flags |= VRING_DESC_F_WRITE; prev = i; - i = virtio16_to_cpu(vq->vdev, desc[i].next); + i = virtqueue_attach_desc(vq, i, sgs[n], flags); } /* Last one doesn't continue */ desc[prev].flags &= cpu_to_virtio16(vq->vdev, ~VRING_DESC_F_NEXT);