There's no need to sync DMA for CPU on mapping errors. So this patch skips the CPU sync in the error handling path of DMA mapping. Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx> --- drivers/virtio/virtio_ring.c | 98 +++++++++++++++++++++--------------- 1 file changed, 57 insertions(+), 41 deletions(-) diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index be7309b1e860..b422b5fb22db 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -441,8 +441,10 @@ static void virtqueue_init(struct vring_virtqueue *vq, u32 num) */ static void vring_unmap_one_split_indirect(const struct vring_virtqueue *vq, - const struct vring_desc *desc) + const struct vring_desc *desc, + bool skip_sync) { + unsigned long attrs = skip_sync ? DMA_ATTR_SKIP_CPU_SYNC : 0; u16 flags; if (!vq->do_unmap) @@ -450,16 +452,18 @@ static void vring_unmap_one_split_indirect(const struct vring_virtqueue *vq, flags = virtio16_to_cpu(vq->vq.vdev, desc->flags); - dma_unmap_page(vring_dma_dev(vq), - virtio64_to_cpu(vq->vq.vdev, desc->addr), - virtio32_to_cpu(vq->vq.vdev, desc->len), - (flags & VRING_DESC_F_WRITE) ? - DMA_FROM_DEVICE : DMA_TO_DEVICE); + dma_unmap_page_attrs(vring_dma_dev(vq), + virtio64_to_cpu(vq->vq.vdev, desc->addr), + virtio32_to_cpu(vq->vq.vdev, desc->len), + (flags & VRING_DESC_F_WRITE) ? + DMA_FROM_DEVICE : DMA_TO_DEVICE, + attrs); } static unsigned int vring_unmap_one_split(const struct vring_virtqueue *vq, - unsigned int i) + unsigned int i, bool skip_sync) { + unsigned long attrs = skip_sync ? DMA_ATTR_SKIP_CPU_SYNC : 0; struct vring_desc_extra *extra = vq->split.desc_extra; u16 flags; @@ -469,20 +473,22 @@ static unsigned int vring_unmap_one_split(const struct vring_virtqueue *vq, if (!vq->use_dma_api) goto out; - dma_unmap_single(vring_dma_dev(vq), - extra[i].addr, - extra[i].len, - (flags & VRING_DESC_F_WRITE) ? - DMA_FROM_DEVICE : DMA_TO_DEVICE); + dma_unmap_single_attrs(vring_dma_dev(vq), + extra[i].addr, + extra[i].len, + (flags & VRING_DESC_F_WRITE) ? + DMA_FROM_DEVICE : DMA_TO_DEVICE, + attrs); } else { if (!vq->do_unmap) goto out; - dma_unmap_page(vring_dma_dev(vq), - extra[i].addr, - extra[i].len, - (flags & VRING_DESC_F_WRITE) ? - DMA_FROM_DEVICE : DMA_TO_DEVICE); + dma_unmap_page_attrs(vring_dma_dev(vq), + extra[i].addr, + extra[i].len, + (flags & VRING_DESC_F_WRITE) ? + DMA_FROM_DEVICE : DMA_TO_DEVICE, + attrs); } out: @@ -717,10 +723,10 @@ static inline int virtqueue_add_split(struct virtqueue *_vq, if (i == err_idx) break; if (indirect) { - vring_unmap_one_split_indirect(vq, &desc[i]); + vring_unmap_one_split_indirect(vq, &desc[i], true); i = virtio16_to_cpu(_vq->vdev, desc[i].next); } else - i = vring_unmap_one_split(vq, i); + i = vring_unmap_one_split(vq, i, true); } free_indirect: @@ -775,12 +781,12 @@ static void detach_buf_split(struct vring_virtqueue *vq, unsigned int head, i = head; while (vq->split.vring.desc[i].flags & nextflag) { - vring_unmap_one_split(vq, i); + vring_unmap_one_split(vq, i, false); i = vq->split.desc_extra[i].next; vq->vq.num_free++; } - vring_unmap_one_split(vq, i); + vring_unmap_one_split(vq, i, false); vq->split.desc_extra[i].next = vq->free_head; vq->free_head = head; @@ -804,7 +810,8 @@ static void detach_buf_split(struct vring_virtqueue *vq, unsigned int head, if (vq->do_unmap) { for (j = 0; j < len / sizeof(struct vring_desc); j++) - vring_unmap_one_split_indirect(vq, &indir_desc[j]); + vring_unmap_one_split_indirect(vq, + &indir_desc[j], false); } kfree(indir_desc); @@ -1221,8 +1228,10 @@ static u16 packed_last_used(u16 last_used_idx) } static void vring_unmap_extra_packed(const struct vring_virtqueue *vq, - const struct vring_desc_extra *extra) + const struct vring_desc_extra *extra, + bool skip_sync) { + unsigned long attrs = skip_sync ? DMA_ATTR_SKIP_CPU_SYNC : 0; u16 flags; flags = extra->flags; @@ -1231,24 +1240,28 @@ static void vring_unmap_extra_packed(const struct vring_virtqueue *vq, if (!vq->use_dma_api) return; - dma_unmap_single(vring_dma_dev(vq), - extra->addr, extra->len, - (flags & VRING_DESC_F_WRITE) ? - DMA_FROM_DEVICE : DMA_TO_DEVICE); + dma_unmap_single_attrs(vring_dma_dev(vq), + extra->addr, extra->len, + (flags & VRING_DESC_F_WRITE) ? + DMA_FROM_DEVICE : DMA_TO_DEVICE, + attrs); } else { if (!vq->do_unmap) return; - dma_unmap_page(vring_dma_dev(vq), - extra->addr, extra->len, - (flags & VRING_DESC_F_WRITE) ? - DMA_FROM_DEVICE : DMA_TO_DEVICE); + dma_unmap_page_attrs(vring_dma_dev(vq), + extra->addr, extra->len, + (flags & VRING_DESC_F_WRITE) ? + DMA_FROM_DEVICE : DMA_TO_DEVICE, + attrs); } } static void vring_unmap_desc_packed(const struct vring_virtqueue *vq, - const struct vring_packed_desc *desc) + const struct vring_packed_desc *desc, + bool skip_sync) { + unsigned long attrs = skip_sync ? DMA_ATTR_SKIP_CPU_SYNC : 0; u16 flags; if (!vq->do_unmap) @@ -1256,11 +1269,12 @@ static void vring_unmap_desc_packed(const struct vring_virtqueue *vq, flags = le16_to_cpu(desc->flags); - dma_unmap_page(vring_dma_dev(vq), - le64_to_cpu(desc->addr), - le32_to_cpu(desc->len), - (flags & VRING_DESC_F_WRITE) ? - DMA_FROM_DEVICE : DMA_TO_DEVICE); + dma_unmap_page_attrs(vring_dma_dev(vq), + le64_to_cpu(desc->addr), + le32_to_cpu(desc->len), + (flags & VRING_DESC_F_WRITE) ? + DMA_FROM_DEVICE : DMA_TO_DEVICE, + attrs); } static struct vring_packed_desc *alloc_indirect_packed(unsigned int total_sg, @@ -1389,7 +1403,7 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, err_idx = i; for (i = 0; i < err_idx; i++) - vring_unmap_desc_packed(vq, &desc[i]); + vring_unmap_desc_packed(vq, &desc[i], true); free_desc: kfree(desc); @@ -1539,7 +1553,8 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq, for (n = 0; n < total_sg; n++) { if (i == err_idx) break; - vring_unmap_extra_packed(vq, &vq->packed.desc_extra[curr]); + vring_unmap_extra_packed(vq, + &vq->packed.desc_extra[curr], true); curr = vq->packed.desc_extra[curr].next; i++; if (i >= vq->packed.vring.num) @@ -1619,7 +1634,8 @@ static void detach_buf_packed(struct vring_virtqueue *vq, curr = id; for (i = 0; i < state->num; i++) { vring_unmap_extra_packed(vq, - &vq->packed.desc_extra[curr]); + &vq->packed.desc_extra[curr], + false); curr = vq->packed.desc_extra[curr].next; } } @@ -1636,7 +1652,7 @@ static void detach_buf_packed(struct vring_virtqueue *vq, len = vq->packed.desc_extra[id].len; for (i = 0; i < len / sizeof(struct vring_packed_desc); i++) - vring_unmap_desc_packed(vq, &desc[i]); + vring_unmap_desc_packed(vq, &desc[i], false); } kfree(desc); state->indir_desc = NULL; -- 2.31.1