[PATCH vhost v10 04/10] virtio_ring: packed: support add premapped buf

[Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>]

If the vq is the premapped mode, use the sg_dma_address() directly.

Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>
---
 drivers/virtio/virtio_ring.c | 36 ++++++++++++++++++++++++++----------
 1 file changed, 26 insertions(+), 10 deletions(-)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 18212c3e056b..dc109fbc05a5 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -1299,9 +1299,13 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq,
 
 	for (n = 0; n < out_sgs + in_sgs; n++) {
 		for (sg = sgs[n]; sg; sg = sg_next(sg)) {
-			if (vring_map_one_sg(vq, sg, n < out_sgs ?
-					     DMA_TO_DEVICE : DMA_FROM_DEVICE, &addr))
-				goto unmap_release;
+			if (vq->premapped) {
+				addr = sg_dma_address(sg);
+			} else {
+				if (vring_map_one_sg(vq, sg, n < out_sgs ?
+						     DMA_TO_DEVICE : DMA_FROM_DEVICE, &addr))
+					goto unmap_release;
+			}
 
 			desc[i].flags = cpu_to_le16(n < out_sgs ?
 						0 : VRING_DESC_F_WRITE);
@@ -1369,10 +1373,12 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq,
 	return 0;
 
 unmap_release:
-	err_idx = i;
+	if (!vq->premapped) {
+		err_idx = i;
 
-	for (i = 0; i < err_idx; i++)
-		vring_unmap_desc_packed(vq, &desc[i]);
+		for (i = 0; i < err_idx; i++)
+			vring_unmap_desc_packed(vq, &desc[i]);
+	}
 
 	kfree(desc);
 
@@ -1447,9 +1453,13 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq,
 		for (sg = sgs[n]; sg; sg = sg_next(sg)) {
 			dma_addr_t addr;
 
-			if (vring_map_one_sg(vq, sg, n < out_sgs ?
-					     DMA_TO_DEVICE : DMA_FROM_DEVICE, &addr))
-				goto unmap_release;
+			if (vq->premapped) {
+				addr = sg_dma_address(sg);
+			} else {
+				if (vring_map_one_sg(vq, sg, n < out_sgs ?
+						     DMA_TO_DEVICE : DMA_FROM_DEVICE, &addr))
+					goto unmap_release;
+			}
 
 			flags = cpu_to_le16(vq->packed.avail_used_flags |
 				    (++c == total_sg ? 0 : VRING_DESC_F_NEXT) |
@@ -1512,11 +1522,17 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq,
 	return 0;
 
 unmap_release:
+	vq->packed.avail_used_flags = avail_used_flags;
+
+	if (vq->premapped) {
+		END_USE(vq);
+		return -EIO;
+	}
+
 	err_idx = i;
 	i = head;
 	curr = vq->free_head;
 
-	vq->packed.avail_used_flags = avail_used_flags;
 
 	for (n = 0; n < total_sg; n++) {
 		if (i == err_idx)
-- 
2.32.0.3.g01195cf9f