DMA-related logic is separated from the virtqueue_add_vring_split() to prepare for subsequent support for premapped.
DMA address will be saved as sg->dma_address, then virtqueue_add_vring_split() will use it directly. If it is a premapped scene, the transmitted sgs should have saved DMA address in dma_address, and in virtio core, we need to pass virtqueue_map_sgs(). Signed-off-by: Xuan Zhuo <[email protected]> --- drivers/virtio/virtio_ring.c | 116 ++++++++++++++++++++++++----------- 1 file changed, 80 insertions(+), 36 deletions(-) diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 3005893ecc61..17520f0d7649 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -520,6 +520,73 @@ static inline unsigned int virtqueue_add_desc_split(struct virtqueue *vq, return next; } +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; + + 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)) + return -ENOMEM; + + 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)) + return -ENOMEM; + + sg->dma_address = addr; + } + } + + return 0; +} + +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); + } + } +} + /* note: return NULL means no indirect that is valid. */ static struct vring_desc *virtqueue_get_desc_split(struct vring_virtqueue *vq, unsigned int total_sg, @@ -577,7 +644,7 @@ static inline int virtqueue_add_vring_split(struct vring_virtqueue *vq, { struct virtqueue *_vq = &vq->vq; struct scatterlist *sg; - unsigned int i, n, avail, descs_used, prev, err_idx; + unsigned int i, n, avail, descs_used, prev; int head; bool indirect; @@ -598,30 +665,25 @@ static inline int virtqueue_add_vring_split(struct vring_virtqueue *vq, 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, + sg->dma_address, + 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, + sg->dma_address, sg->length, VRING_DESC_F_NEXT | VRING_DESC_F_WRITE, @@ -640,7 +702,7 @@ static inline int virtqueue_add_vring_split(struct vring_virtqueue *vq, vq, desc, total_sg * sizeof(struct vring_desc), DMA_TO_DEVICE); if (vring_mapping_error(vq, addr)) - goto unmap_release; + return -ENOMEM; virtqueue_add_desc_split(_vq, vq->split.vring.desc, head, addr, @@ -680,30 +742,6 @@ static inline int virtqueue_add_vring_split(struct vring_virtqueue *vq, virtqueue_kick(_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); - } - - if (indirect) - kfree(desc); - - END_USE(vq); - return -ENOMEM; } static inline int virtqueue_add_split(struct virtqueue *_vq, @@ -729,6 +767,10 @@ static inline int virtqueue_add_split(struct virtqueue *_vq, goto end; } + err = virtqueue_map_sgs(vq, sgs, total_sg, out_sgs, in_sgs); + if (err) + goto err; + head = vq->free_head; err = virtqueue_add_vring_split(vq, sgs, total_sg, out_sgs, in_sgs, desc); if (err) @@ -741,6 +783,8 @@ static inline int virtqueue_add_split(struct virtqueue *_vq, goto end; err: + virtqueue_unmap_sgs(vq, sgs, total_sg, out_sgs, in_sgs); + kfree(desc); end: -- 2.32.0.3.g01195cf9f _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
