[PATCH vhost v3 14/19] virtio_ring: remove api of setting vq premapped

[Xuan Zhuo <xuanzhuo@linux.alibaba.com>]

The virtio-net sets the premapped mode by find_vqs().

So the below API is not used by anyone, we remove it.

int virtqueue_set_dma_premapped(struct virtqueue *_vq);

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
---
 drivers/virtio/virtio_ring.c | 56 ------------------------------------
 include/linux/virtio.h       |  2 --
 2 files changed, 58 deletions(-)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 103b06574e8b..63084487c171 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -2775,62 +2775,6 @@ 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: vring does not use the dma api, so we can not enable premapped mode.
- */
-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;
-	}
-
-	if (!vq->use_dma_api) {
-		END_USE(vq);
-		return -EINVAL;
-	}
-
-	vq->vq.premapped = true;
-
-	if (vq->packed_ring) {
-		kfree(vq->packed.desc_dma);
-		vq->packed.desc_dma = NULL;
-	} else {
-		kfree(vq->split.desc_dma);
-		vq->split.desc_dma = NULL;
-	}
-
-	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 407277d5a16b..2167893313f6 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