Factor out the core logic for updating last_used_idx to be reused by
the packed in order implementation.
Acked-by: Eugenio Pérez <eperezma@xxxxxxxxxx>
Reviewed-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>
Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
---
drivers/virtio/virtio_ring.c | 43 +++++++++++++++++++++---------------
1 file changed, 25 insertions(+), 18 deletions(-)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index b0eb68efb535..271508203443 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -1751,6 +1751,30 @@ static bool more_used_packed(const struct vring_virtqueue *vq)
return virtqueue_poll_packed(vq, READ_ONCE(vq->last_used_idx));
}
+static void update_last_used_idx_packed(struct vring_virtqueue *vq,
+ u16 id, u16 last_used,
+ u16 used_wrap_counter)
+{
+ last_used += vq->packed.desc_state[id].num;
+ if (unlikely(last_used >= vq->packed.vring.num)) {
+ last_used -= vq->packed.vring.num;
+ used_wrap_counter ^= 1;
+ }
+
+ last_used = (last_used | (used_wrap_counter << VRING_PACKED_EVENT_F_WRAP_CTR));
+ WRITE_ONCE(vq->last_used_idx, last_used);
+
+ /*
+ * If we expect an interrupt for the next entry, tell host
+ * by writing event index and flush out the write before
+ * the read in the next get_buf call.
+ */
+ if (vq->packed.event_flags_shadow == VRING_PACKED_EVENT_FLAG_DESC)
+ virtio_store_mb(vq->weak_barriers,
+ &vq->packed.vring.driver->off_wrap,
+ cpu_to_le16(vq->last_used_idx));
+}
+
static void *virtqueue_get_buf_ctx_packed(struct vring_virtqueue *vq,
unsigned int *len,
void **ctx)
@@ -1794,24 +1818,7 @@ static void *virtqueue_get_buf_ctx_packed(struct vring_virtqueue *vq,
ret = vq->packed.desc_state[id].data;
detach_buf_packed(vq, id, ctx);
- last_used += vq->packed.desc_state[id].num;
- if (unlikely(last_used >= vq->packed.vring.num)) {
- last_used -= vq->packed.vring.num;
- used_wrap_counter ^= 1;
- }
-
- last_used = (last_used | (used_wrap_counter << VRING_PACKED_EVENT_F_WRAP_CTR));
- WRITE_ONCE(vq->last_used_idx, last_used);
-
- /*
- * If we expect an interrupt for the next entry, tell host
- * by writing event index and flush out the write before
- * the read in the next get_buf call.
- */
- if (vq->packed.event_flags_shadow == VRING_PACKED_EVENT_FLAG_DESC)
- virtio_store_mb(vq->weak_barriers,
- &vq->packed.vring.driver->off_wrap,
- cpu_to_le16(vq->last_used_idx));
+ update_last_used_idx_packed(vq, id, last_used, used_wrap_counter);
LAST_ADD_TIME_INVALID(vq);
--
2.39.5
