[RFC net-next v1 06/12] virtio_ring: remove API virtqueue_set_dma_premapped

[Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>]

Now, this API is useless. remove it.

Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>
---
 drivers/virtio/virtio_ring.c | 48 ------------------------------------
 include/linux/virtio.h       |  2 --
 2 files changed, 50 deletions(-)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index b570acb35d97..6edfcd4d1606 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -180,9 +180,6 @@ struct vring_virtqueue {
 	/* Host publishes avail event idx */
 	bool event;
 
-	/* Do DMA mapping by driver */
-	bool premapped;
-
 	/* Head of free buffer list. */
 	unsigned int free_head;
 	/* Number we've added since last sync. */
@@ -2086,7 +2083,6 @@ static struct virtqueue *vring_create_virtqueue_packed(
 	vq->packed_ring = true;
 	vq->dma_dev = dma_dev;
 	vq->use_dma_api = vring_use_dma_api(vdev);
-	vq->premapped = false;
 
 	vq->indirect = virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC) &&
 		!context;
@@ -2650,7 +2646,6 @@ static struct virtqueue *__vring_new_virtqueue(unsigned int index,
 #endif
 	vq->dma_dev = dma_dev;
 	vq->use_dma_api = vring_use_dma_api(vdev);
-	vq->premapped = false;
 
 	vq->indirect = virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC) &&
 		!context;
@@ -2777,49 +2772,6 @@ int virtqueue_resize(struct virtqueue *_vq, u32 num,
 }
 EXPORT_SYMBOL_GPL(virtqueue_resize);
 
-/**
- * virtqueue_set_dma_premapped - set the vring premapped mode
- * @_vq: the struct virtqueue we're talking about.
- *
- * Enable the premapped mode of the vq.
- *
- * The vring in premapped mode does not do dma internally, so the driver must
- * do dma mapping in advance. The driver must pass the dma_address through
- * dma_address of scatterlist. When the driver got a used buffer from
- * the vring, it has to unmap the dma address.
- *
- * This function must be called immediately after creating the vq, or after vq
- * reset, and before adding any buffers to it.
- *
- * Caller must ensure we don't call this with other virtqueue operations
- * at the same time (except where noted).
- *
- * Returns zero or a negative error.
- * 0: success.
- * -EINVAL: too late to enable premapped mode, the vq already contains buffers.
- */
-int virtqueue_set_dma_premapped(struct virtqueue *_vq)
-{
-	struct vring_virtqueue *vq = to_vvq(_vq);
-	u32 num;
-
-	START_USE(vq);
-
-	num = vq->packed_ring ? vq->packed.vring.num : vq->split.vring.num;
-
-	if (num != vq->vq.num_free) {
-		END_USE(vq);
-		return -EINVAL;
-	}
-
-	vq->premapped = true;
-
-	END_USE(vq);
-
-	return 0;
-}
-EXPORT_SYMBOL_GPL(virtqueue_set_dma_premapped);
-
 /**
  * virtqueue_reset - detach and recycle all unused buffers
  * @_vq: the struct virtqueue we're talking about.
diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index 306137a15d07..238728ed62fa 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -82,8 +82,6 @@ bool virtqueue_enable_cb(struct virtqueue *vq);
 
 unsigned virtqueue_enable_cb_prepare(struct virtqueue *vq);
 
-int virtqueue_set_dma_premapped(struct virtqueue *_vq);
-
 bool virtqueue_poll(struct virtqueue *vq, unsigned);
 
 bool virtqueue_enable_cb_delayed(struct virtqueue *vq);
-- 
2.32.0.3.g01195cf9f