On Tue, Mar 28, 2023 at 2:24 PM Jason Wang <jasow...@redhat.com> wrote: > > > 在 2023/3/22 10:56, Xuan Zhuo 写道: > > DMA-related logic is separated from the virtqueue_add_split() to > > one new function. DMA address will be saved as sg->dma_address if > > use_dma_api is true, then virtqueue_add_split() 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> > > > Acked-by: Jason Wang <jasow...@redhat.com> > > Thanks
Please ignore this, hit the button accidentally. Thanks > > > > --- > > drivers/virtio/virtio_ring.c | 121 +++++++++++++++++++++++++++-------- > > 1 file changed, 93 insertions(+), 28 deletions(-) > > > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > > index 41144b5246a8..fe704ca6c813 100644 > > --- a/drivers/virtio/virtio_ring.c > > +++ b/drivers/virtio/virtio_ring.c > > @@ -379,6 +379,14 @@ static dma_addr_t vring_map_one_sg(const struct > > vring_virtqueue *vq, > > direction); > > } > > > > +static dma_addr_t vring_sg_address(struct scatterlist *sg) > > +{ > > + if (sg->dma_address) > > + return sg->dma_address; > > + > > + return (dma_addr_t)sg_phys(sg); > > +} > > + > > static dma_addr_t vring_map_single(const struct vring_virtqueue *vq, > > void *cpu_addr, size_t size, > > enum dma_data_direction direction) > > @@ -520,6 +528,80 @@ static inline unsigned int > > virtqueue_add_desc_split(struct virtqueue *vq, > > return next; > > } > > > > +static void virtqueue_unmap_sgs(struct vring_virtqueue *vq, > > + struct scatterlist *sgs[], > > + unsigned int total_sg, > > + unsigned int out_sgs, > > + unsigned int in_sgs) > > +{ > > + struct scatterlist *sg; > > + unsigned int n; > > + > > + if (!vq->use_dma_api) > > + return; > > + > > + for (n = 0; n < out_sgs; n++) { > > + for (sg = sgs[n]; sg; sg = sg_next(sg)) { > > + if (!sg->dma_address) > > + return; > > + > > + dma_unmap_page(vring_dma_dev(vq), sg->dma_address, > > + sg->length, DMA_TO_DEVICE); > > + } > > + } > > + > > + for (; n < (out_sgs + in_sgs); n++) { > > + for (sg = sgs[n]; sg; sg = sg_next(sg)) { > > + if (!sg->dma_address) > > + return; > > + > > + dma_unmap_page(vring_dma_dev(vq), sg->dma_address, > > + sg->length, DMA_FROM_DEVICE); > > + } > > + } > > +} > > + > > +static int virtqueue_map_sgs(struct vring_virtqueue *vq, > > + struct scatterlist *sgs[], > > + unsigned int total_sg, > > + unsigned int out_sgs, > > + unsigned int in_sgs) > > +{ > > + struct scatterlist *sg; > > + unsigned int n; > > + > > + if (!vq->use_dma_api) > > + return 0; > > + > > + for (n = 0; n < out_sgs; n++) { > > + for (sg = sgs[n]; sg; sg = sg_next(sg)) { > > + dma_addr_t addr = vring_map_one_sg(vq, sg, > > DMA_TO_DEVICE); > > + > > + if (vring_mapping_error(vq, addr)) > > + goto err; > > + > > + sg->dma_address = addr; > > + } > > + } > > + > > + for (; 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, > > DMA_FROM_DEVICE); > > + > > + if (vring_mapping_error(vq, addr)) > > + goto err; > > + > > + sg->dma_address = addr; > > + } > > + } > > + > > + return 0; > > + > > +err: > > + virtqueue_unmap_sgs(vq, sgs, total_sg, out_sgs, in_sgs); > > + return -ENOMEM; > > +} > > + > > static inline int virtqueue_add_split(struct virtqueue *_vq, > > struct scatterlist *sgs[], > > unsigned int total_sg, > > @@ -532,9 +614,9 @@ static inline int virtqueue_add_split(struct virtqueue > > *_vq, > > struct vring_virtqueue *vq = to_vvq(_vq); > > struct scatterlist *sg; > > struct vring_desc *desc; > > - unsigned int i, n, avail, descs_used, prev, err_idx; > > - int head; > > + unsigned int i, n, avail, descs_used, prev; > > bool indirect; > > + int head; > > > > START_USE(vq); > > > > @@ -586,32 +668,30 @@ static inline int virtqueue_add_split(struct > > virtqueue *_vq, > > return -ENOSPC; > > } > > > > + if (virtqueue_map_sgs(vq, sgs, total_sg, out_sgs, in_sgs)) > > + return -ENOMEM; > > + > > for (n = 0; n < out_sgs; n++) { > > for (sg = sgs[n]; sg; sg = sg_next(sg)) { > > - dma_addr_t addr = vring_map_one_sg(vq, sg, > > DMA_TO_DEVICE); > > - if (vring_mapping_error(vq, addr)) > > - goto unmap_release; > > - > > prev = i; > > /* Note that we trust indirect descriptor > > * table since it use stream DMA mapping. > > */ > > - i = virtqueue_add_desc_split(_vq, desc, i, addr, > > sg->length, > > + i = virtqueue_add_desc_split(_vq, desc, i, > > + vring_sg_address(sg), > > + sg->length, > > VRING_DESC_F_NEXT, > > indirect); > > } > > } > > for (; 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, > > DMA_FROM_DEVICE); > > - if (vring_mapping_error(vq, addr)) > > - goto unmap_release; > > - > > prev = i; > > /* Note that we trust indirect descriptor > > * table since it use stream DMA mapping. > > */ > > - i = virtqueue_add_desc_split(_vq, desc, i, addr, > > + i = virtqueue_add_desc_split(_vq, desc, i, > > + vring_sg_address(sg), > > sg->length, > > VRING_DESC_F_NEXT | > > VRING_DESC_F_WRITE, > > @@ -679,22 +759,7 @@ static inline int virtqueue_add_split(struct virtqueue > > *_vq, > > return 0; > > > > unmap_release: > > - err_idx = i; > > - > > - if (indirect) > > - i = 0; > > - else > > - i = head; > > - > > - for (n = 0; n < total_sg; n++) { > > - if (i == err_idx) > > - break; > > - if (indirect) { > > - vring_unmap_one_split_indirect(vq, &desc[i]); > > - i = virtio16_to_cpu(_vq->vdev, desc[i].next); > > - } else > > - i = vring_unmap_one_split(vq, i); > > - } > > + virtqueue_unmap_sgs(vq, sgs, total_sg, out_sgs, in_sgs); > > > > if (indirect) > > kfree(desc); _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization