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authorXuan Zhuo <xuanzhuo@linux.alibaba.com>2023-08-10 15:30:50 +0300
committerMichael S. Tsirkin <mst@redhat.com>2023-09-04 01:10:23 +0300
commit2df64759071bdca2a12edb9af4f071e4419ad745 (patch)
tree93b5c07e34c34572f96514dd1366394cc0f27911 /drivers
parentd7344a2f71e38eb04fc16e3fef4f0580f42cbbd5 (diff)
downloadlinux-2df64759071bdca2a12edb9af4f071e4419ad745.tar.xz
virtio_ring: introduce virtqueue_dma_dev()
Added virtqueue_dma_dev() to get DMA device for virtio. Then the caller can do dma operation in advance. The purpose is to keep memory mapped across multiple add/get buf operations. Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Acked-by: Jason Wang <jasowang@redhat.com> Message-Id: <20230810123057.43407-6-xuanzhuo@linux.alibaba.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/virtio/virtio_ring.c17
1 files changed, 17 insertions, 0 deletions
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index f9f772e85a38..bb3d73d221cd 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -2266,6 +2266,23 @@ int virtqueue_add_inbuf_ctx(struct virtqueue *vq,
EXPORT_SYMBOL_GPL(virtqueue_add_inbuf_ctx);
/**
+ * virtqueue_dma_dev - get the dma dev
+ * @_vq: the struct virtqueue we're talking about.
+ *
+ * Returns the dma dev. That can been used for dma api.
+ */
+struct device *virtqueue_dma_dev(struct virtqueue *_vq)
+{
+ struct vring_virtqueue *vq = to_vvq(_vq);
+
+ if (vq->use_dma_api)
+ return vring_dma_dev(vq);
+ else
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(virtqueue_dma_dev);
+
+/**
* virtqueue_kick_prepare - first half of split virtqueue_kick call.
* @_vq: the struct virtqueue
*