On Wed, Mar 22, 2023 at 10:57 AM Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx> wrote:
>
> DMA-related logic is separated from the virtqueue_add_packed(). DMA
> address will be saved as sg->dma_address, then virtqueue_add_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 <xuanzhuo@xxxxxxxxxxxxxxxxx>
> ---
> drivers/virtio/virtio_ring.c | 37 +++++++-----------------------------
> 1 file changed, 7 insertions(+), 30 deletions(-)
>
> diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
> index fe704ca6c813..42e8c9d44161 100644
> --- a/drivers/virtio/virtio_ring.c
> +++ b/drivers/virtio/virtio_ring.c
> @@ -1430,9 +1430,9 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq,
> struct vring_virtqueue *vq = to_vvq(_vq);
> struct vring_packed_desc *desc;
> struct scatterlist *sg;
> - unsigned int i, n, c, descs_used, err_idx;
> + unsigned int i, n, c, descs_used;
> __le16 head_flags, flags;
> - u16 head, id, prev, curr, avail_used_flags;
> + u16 head, id, prev, curr;
> int err;
>
> START_USE(vq);
> @@ -1461,7 +1461,6 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq,
> }
>
> head = vq->packed.next_avail_idx;
> - avail_used_flags = vq->packed.avail_used_flags;
>
> WARN_ON_ONCE(total_sg > vq->packed.vring.num && !vq->indirect);
>
> @@ -1479,15 +1478,13 @@ static inline int virtqueue_add_packed(struct 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))
END_USE(vq) is needed.
> + return -ENOMEM;
Is it better to use -EIO (we use this before this patch).
With those fixed, you can add my:
Acked-by: Jason Wang <jasowang@xxxxxxxxxx>
Thanks
> +
> curr = id;
> c = 0;
> for (n = 0; n < out_sgs + in_sgs; n++) {
> for (sg = sgs[n]; sg; sg = sg_next(sg)) {
> - dma_addr_t 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;
> -
> flags = cpu_to_le16(vq->packed.avail_used_flags |
> (++c == total_sg ? 0 : VRING_DESC_F_NEXT) |
> (n < out_sgs ? 0 : VRING_DESC_F_WRITE));
> @@ -1496,12 +1493,12 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq,
> else
> desc[i].flags = flags;
>
> - desc[i].addr = cpu_to_le64(addr);
> + desc[i].addr = cpu_to_le64(vring_sg_address(sg));
> desc[i].len = cpu_to_le32(sg->length);
> desc[i].id = cpu_to_le16(id);
>
> if (unlikely(vq->use_dma_api)) {
> - vq->packed.desc_extra[curr].addr = addr;
> + vq->packed.desc_extra[curr].addr = vring_sg_address(sg);
> vq->packed.desc_extra[curr].len = sg->length;
> vq->packed.desc_extra[curr].flags =
> le16_to_cpu(flags);
> @@ -1547,26 +1544,6 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq,
> END_USE(vq);
>
> return 0;
> -
> -unmap_release:
> - 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)
> - break;
> - vring_unmap_extra_packed(vq, &vq->packed.desc_extra[curr]);
> - curr = vq->packed.desc_extra[curr].next;
> - i++;
> - if (i >= vq->packed.vring.num)
> - i = 0;
> - }
> -
> - END_USE(vq);
> - return -EIO;
> }
>
> static bool virtqueue_kick_prepare_packed(struct virtqueue *_vq)
> --
> 2.32.0.3.g01195cf9f
>
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