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 <xuanzhuo@xxxxxxxxxxxxxxxxx>
---
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
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