diff options
author | Xuan Zhuo <xuanzhuo@linux.alibaba.com> | 2023-08-10 15:30:51 +0300 |
---|---|---|
committer | Michael S. Tsirkin <mst@redhat.com> | 2023-09-04 01:10:23 +0300 |
commit | b319940f83c21bb4c1fabffe68a862be879a6193 (patch) | |
tree | 5d69c2538deabac5419fb3eef41fc0e1d14346e2 /drivers/virtio/virtio_ring.c | |
parent | 2df64759071bdca2a12edb9af4f071e4419ad745 (diff) | |
download | linux-b319940f83c21bb4c1fabffe68a862be879a6193.tar.xz |
virtio_ring: skip unmap for premapped
Now we add a case where we skip dma unmap, the vq->premapped is true.
We can't just rely on use_dma_api to determine whether to skip the dma
operation. For convenience, I introduced the "do_unmap". By default, it
is the same as use_dma_api. If the driver is configured with premapped,
then do_unmap is false.
So as long as do_unmap is false, for addr of desc, we should skip dma
unmap operation.
Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Message-Id: <20230810123057.43407-7-xuanzhuo@linux.alibaba.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'drivers/virtio/virtio_ring.c')
-rw-r--r-- | drivers/virtio/virtio_ring.c | 42 |
1 files changed, 28 insertions, 14 deletions
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index bb3d73d221cd..7973814b6e31 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -175,6 +175,11 @@ struct vring_virtqueue { /* Do DMA mapping by driver */ bool premapped; + /* Do unmap or not for desc. Just when premapped is False and + * use_dma_api is true, this is true. + */ + bool do_unmap; + /* Head of free buffer list. */ unsigned int free_head; /* Number we've added since last sync. */ @@ -440,7 +445,7 @@ static void vring_unmap_one_split_indirect(const struct vring_virtqueue *vq, { u16 flags; - if (!vq->use_dma_api) + if (!vq->do_unmap) return; flags = virtio16_to_cpu(vq->vq.vdev, desc->flags); @@ -458,18 +463,21 @@ static unsigned int vring_unmap_one_split(const struct vring_virtqueue *vq, struct vring_desc_extra *extra = vq->split.desc_extra; u16 flags; - if (!vq->use_dma_api) - goto out; - flags = extra[i].flags; if (flags & VRING_DESC_F_INDIRECT) { + 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); } else { + if (!vq->do_unmap) + goto out; + dma_unmap_page(vring_dma_dev(vq), extra[i].addr, extra[i].len, @@ -635,7 +643,7 @@ static inline int virtqueue_add_split(struct virtqueue *_vq, } /* Last one doesn't continue. */ desc[prev].flags &= cpu_to_virtio16(_vq->vdev, ~VRING_DESC_F_NEXT); - if (!indirect && vq->use_dma_api) + if (!indirect && vq->do_unmap) vq->split.desc_extra[prev & (vq->split.vring.num - 1)].flags &= ~VRING_DESC_F_NEXT; @@ -794,7 +802,7 @@ static void detach_buf_split(struct vring_virtqueue *vq, unsigned int head, VRING_DESC_F_INDIRECT)); BUG_ON(len == 0 || len % sizeof(struct vring_desc)); - if (vq->use_dma_api) { + if (vq->do_unmap) { for (j = 0; j < len / sizeof(struct vring_desc); j++) vring_unmap_one_split_indirect(vq, &indir_desc[j]); } @@ -1217,17 +1225,20 @@ static void vring_unmap_extra_packed(const struct vring_virtqueue *vq, { u16 flags; - if (!vq->use_dma_api) - return; - flags = extra->flags; if (flags & VRING_DESC_F_INDIRECT) { + 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); } else { + if (!vq->do_unmap) + return; + dma_unmap_page(vring_dma_dev(vq), extra->addr, extra->len, (flags & VRING_DESC_F_WRITE) ? @@ -1240,7 +1251,7 @@ static void vring_unmap_desc_packed(const struct vring_virtqueue *vq, { u16 flags; - if (!vq->use_dma_api) + if (!vq->do_unmap) return; flags = le16_to_cpu(desc->flags); @@ -1329,7 +1340,7 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, sizeof(struct vring_packed_desc)); vq->packed.vring.desc[head].id = cpu_to_le16(id); - if (vq->use_dma_api) { + if (vq->do_unmap) { vq->packed.desc_extra[id].addr = addr; vq->packed.desc_extra[id].len = total_sg * sizeof(struct vring_packed_desc); @@ -1470,7 +1481,7 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq, desc[i].len = cpu_to_le32(sg->length); desc[i].id = cpu_to_le16(id); - if (unlikely(vq->use_dma_api)) { + if (unlikely(vq->do_unmap)) { vq->packed.desc_extra[curr].addr = addr; vq->packed.desc_extra[curr].len = sg->length; vq->packed.desc_extra[curr].flags = @@ -1604,7 +1615,7 @@ static void detach_buf_packed(struct vring_virtqueue *vq, vq->free_head = id; vq->vq.num_free += state->num; - if (unlikely(vq->use_dma_api)) { + if (unlikely(vq->do_unmap)) { curr = id; for (i = 0; i < state->num; i++) { vring_unmap_extra_packed(vq, @@ -1621,7 +1632,7 @@ static void detach_buf_packed(struct vring_virtqueue *vq, if (!desc) return; - if (vq->use_dma_api) { + if (vq->do_unmap) { len = vq->packed.desc_extra[id].len; for (i = 0; i < len / sizeof(struct vring_packed_desc); i++) @@ -2080,6 +2091,7 @@ static struct virtqueue *vring_create_virtqueue_packed( vq->dma_dev = dma_dev; vq->use_dma_api = vring_use_dma_api(vdev); vq->premapped = false; + vq->do_unmap = vq->use_dma_api; vq->indirect = virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC) && !context; @@ -2587,6 +2599,7 @@ static struct virtqueue *__vring_new_virtqueue(unsigned int index, vq->dma_dev = dma_dev; vq->use_dma_api = vring_use_dma_api(vdev); vq->premapped = false; + vq->do_unmap = vq->use_dma_api; vq->indirect = virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC) && !context; @@ -2771,6 +2784,7 @@ int virtqueue_set_dma_premapped(struct virtqueue *_vq) } vq->premapped = true; + vq->do_unmap = false; END_USE(vq); |