DMA-related logic is separated from the virtqueue_add_indirect_packed().

DMA address will be saved as sg->dma_address, then
virtqueue_add_indirect_packed() will use it directly. Unmap operation
will be simpler.

The purpose of this is to facilitate subsequent support to receive
dma address mapped by drivers.

Signed-off-by: Xuan Zhuo <xuanz...@linux.alibaba.com>
---
 drivers/virtio/virtio_ring.c | 17 ++++++-----------
 1 file changed, 6 insertions(+), 11 deletions(-)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index b4beb51072f7..221ff54fe58b 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -1303,7 +1303,7 @@ static int virtqueue_add_indirect_packed(struct 
vring_virtqueue *vq,
 {
        struct vring_packed_desc *desc;
        struct scatterlist *sg;
-       unsigned int i, n, err_idx;
+       unsigned int i, n;
        u16 head, id;
        dma_addr_t addr;
 
@@ -1323,16 +1323,14 @@ static int virtqueue_add_indirect_packed(struct 
vring_virtqueue *vq,
        id = vq->free_head;
        BUG_ON(id == vq->packed.vring.num);
 
+       if (virtqueue_map_sgs(vq, sgs, total_sg, out_sgs, in_sgs))
+               return -ENOMEM;
+
        for (n = 0; n < out_sgs + in_sgs; n++) {
                for (sg = sgs[n]; sg; sg = sg_next(sg)) {
-                       addr = vring_map_one_sg(vq, sg, n < out_sgs ?
-                                       DMA_TO_DEVICE : DMA_FROM_DEVICE);
-                       if (vring_mapping_error(vq, addr))
-                               goto unmap_release;
-
                        desc[i].flags = cpu_to_le16(n < out_sgs ?
                                                0 : VRING_DESC_F_WRITE);
-                       desc[i].addr = cpu_to_le64(addr);
+                       desc[i].addr = cpu_to_le64(sg->dma_address);
                        desc[i].len = cpu_to_le32(sg->length);
                        i++;
                }
@@ -1396,10 +1394,7 @@ static int virtqueue_add_indirect_packed(struct 
vring_virtqueue *vq,
        return 0;
 
 unmap_release:
-       err_idx = i;
-
-       for (i = 0; i < err_idx; i++)
-               vring_unmap_desc_packed(vq, &desc[i]);
+       virtqueue_unmap_sgs(vq, sgs, total_sg, out_sgs, in_sgs);
 
        kfree(desc);
 
-- 
2.32.0.3.g01195cf9f

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