Separate the logic for updating the vq state from virtqueue_add_split(). In this way, when the subsequent patch implements the logic of reusing the buffer when resize, we can share this function.
Signed-off-by: Xuan Zhuo <[email protected]> --- drivers/virtio/virtio_ring.c | 95 ++++++++++++++++++++---------------- 1 file changed, 54 insertions(+), 41 deletions(-) diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index f3ad9322b512..6fd45c9a3517 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -507,6 +507,51 @@ static inline unsigned int virtqueue_add_desc_split(struct virtqueue *vq, return next; } +static inline void virtqueue_update_split(struct vring_virtqueue *vq, + u32 descs_used, + u32 next, + struct vring_desc *desc, + void *data) +{ + struct virtqueue *_vq = &vq->vq; + u32 avail, head; + + head = vq->free_head; + + /* We're using some buffers from the free list. */ + vq->vq.num_free -= descs_used; + + /* Update free pointer */ + vq->free_head = next; + + /* Store token and indirect buffer state. */ + vq->split.desc_state[head].data = data; + vq->split.desc_state[head].indir_desc = desc; + + /* Put entry in available array (but don't update avail->idx until they + * do sync). + */ + avail = vq->split.avail_idx_shadow & (vq->split.vring.num - 1); + vq->split.vring.avail->ring[avail] = cpu_to_virtio16(_vq->vdev, head); + + /* Descriptors and available array need to be set before we expose the + * new available array entries. + */ + virtio_wmb(vq->weak_barriers); + vq->split.avail_idx_shadow++; + vq->split.vring.avail->idx = cpu_to_virtio16(_vq->vdev, + vq->split.avail_idx_shadow); + vq->num_added++; + + pr_debug("Added buffer head %i to %p\n", head, vq); + + /* This is very unlikely, but theoretically possible. Kick + * just in case. + */ + if (unlikely(vq->num_added == (1 << 16) - 1)) + virtqueue_kick(_vq); +} + static inline int virtqueue_add_split(struct virtqueue *_vq, struct scatterlist *sgs[], unsigned int total_sg, @@ -519,7 +564,7 @@ static inline int virtqueue_add_split(struct virtqueue *_vq, struct vring_virtqueue *vq = to_vvq(_vq); struct scatterlist *sg; struct vring_desc *desc; - unsigned int i, n, avail, descs_used, prev, err_idx; + unsigned int i, n, descs_used, prev, err_idx; int head; bool indirect; @@ -619,50 +664,18 @@ static inline int virtqueue_add_split(struct virtqueue *_vq, if (vring_mapping_error(vq, addr)) goto unmap_release; - virtqueue_add_desc_split(_vq, vq->split.vring.desc, - head, addr, - total_sg * sizeof(struct vring_desc), - VRING_DESC_F_INDIRECT, - false); + i = virtqueue_add_desc_split(_vq, vq->split.vring.desc, + head, addr, + total_sg * sizeof(struct vring_desc), + VRING_DESC_F_INDIRECT, + false); + } else { + desc = ctx; } - /* We're using some buffers from the free list. */ - vq->vq.num_free -= descs_used; - - /* Update free pointer */ - if (indirect) - vq->free_head = vq->split.desc_extra[head].next; - else - vq->free_head = i; - - /* Store token and indirect buffer state. */ - vq->split.desc_state[head].data = data; - if (indirect) - vq->split.desc_state[head].indir_desc = desc; - else - vq->split.desc_state[head].indir_desc = ctx; - - /* Put entry in available array (but don't update avail->idx until they - * do sync). */ - avail = vq->split.avail_idx_shadow & (vq->split.vring.num - 1); - vq->split.vring.avail->ring[avail] = cpu_to_virtio16(_vq->vdev, head); - - /* Descriptors and available array need to be set before we expose the - * new available array entries. */ - virtio_wmb(vq->weak_barriers); - vq->split.avail_idx_shadow++; - vq->split.vring.avail->idx = cpu_to_virtio16(_vq->vdev, - vq->split.avail_idx_shadow); - vq->num_added++; - - pr_debug("Added buffer head %i to %p\n", head, vq); + virtqueue_update_split(vq, descs_used, i, desc, data); END_USE(vq); - /* This is very unlikely, but theoretically possible. Kick - * just in case. */ - if (unlikely(vq->num_added == (1 << 16) - 1)) - virtqueue_kick(_vq); - return 0; unmap_release: -- 2.31.0 _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
