@@ -175,11 +175,6 @@ 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. */
@@ -297,6 +292,11 @@ static bool vring_use_dma_api(const struct virtio_device *vdev)
return false;
}
+static bool vring_need_unmap_buffer(const struct vring_virtqueue *vring)
+{
+ return vring->use_dma_api && !vring->premapped;
+}
+
size_t virtio_max_dma_size(const struct virtio_device *vdev)
{
size_t max_segment_size = SIZE_MAX;
@@ -445,7 +445,7 @@ static void vring_unmap_one_split_indirect(const struct vring_virtqueue *vq,
{
u16 flags;
- if (!vq->do_unmap)
+ if (!vring_need_unmap_buffer(vq))
return;
flags = virtio16_to_cpu(vq->vq.vdev, desc->flags);
@@ -475,7 +475,7 @@ static unsigned int vring_unmap_one_split(const struct vring_virtqueue *vq,
(flags & VRING_DESC_F_WRITE) ?
DMA_FROM_DEVICE : DMA_TO_DEVICE);
} else {
- if (!vq->do_unmap)
+ if (!vring_need_unmap_buffer(vq))
goto out;
dma_unmap_page(vring_dma_dev(vq),
@@ -643,7 +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->do_unmap)
+ if (!indirect && vring_need_unmap_buffer(vq))
vq->split.desc_extra[prev & (vq->split.vring.num - 1)].flags &=
~VRING_DESC_F_NEXT;
@@ -802,7 +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->do_unmap) {
+ if (vring_need_unmap_buffer(vq)) {
for (j = 0; j < len / sizeof(struct vring_desc); j++)
vring_unmap_one_split_indirect(vq, &indir_desc[j]);
}
@@ -1236,7 +1236,7 @@ static void vring_unmap_extra_packed(const struct vring_virtqueue *vq,
(flags & VRING_DESC_F_WRITE) ?
DMA_FROM_DEVICE : DMA_TO_DEVICE);
} else {
- if (!vq->do_unmap)
+ if (!vring_need_unmap_buffer(vq))
return;
dma_unmap_page(vring_dma_dev(vq),
@@ -1251,7 +1251,7 @@ static void vring_unmap_desc_packed(const struct vring_virtqueue *vq,
{
u16 flags;
- if (!vq->do_unmap)
+ if (!vring_need_unmap_buffer(vq))
return;
flags = le16_to_cpu(desc->flags);
@@ -1340,7 +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->do_unmap) {
+ if (vring_need_unmap_buffer(vq)) {
vq->packed.desc_extra[id].addr = addr;
vq->packed.desc_extra[id].len = total_sg *
sizeof(struct vring_packed_desc);
@@ -1481,7 +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->do_unmap)) {
+ if (unlikely(vring_need_unmap_buffer(vq))) {
vq->packed.desc_extra[curr].addr = addr;
vq->packed.desc_extra[curr].len = sg->length;
vq->packed.desc_extra[curr].flags =
@@ -1615,7 +1615,7 @@ static void detach_buf_packed(struct vring_virtqueue *vq,
vq->free_head = id;
vq->vq.num_free += state->num;
- if (unlikely(vq->do_unmap)) {
+ if (unlikely(vring_need_unmap_buffer(vq))) {
curr = id;
for (i = 0; i < state->num; i++) {
vring_unmap_extra_packed(vq,
@@ -1632,7 +1632,7 @@ static void detach_buf_packed(struct vring_virtqueue *vq,
if (!desc)
return;
- if (vq->do_unmap) {
+ if (vring_need_unmap_buffer(vq)) {
len = vq->packed.desc_extra[id].len;
for (i = 0; i < len / sizeof(struct vring_packed_desc);
i++)
@@ -2091,7 +2091,6 @@ 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;
@@ -2636,7 +2635,6 @@ 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;
@@ -2804,7 +2802,6 @@ int virtqueue_set_dma_premapped(struct virtqueue *_vq)
}
vq->premapped = true;
- vq->do_unmap = false;
END_USE(vq);
To make the code readable, introduce vring_need_unmap_buffer() to replace do_unmap. use_dma_api premapped -> vring_need_unmap_buffer() 1. false false false 2. true false true 3. true true false Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> --- drivers/virtio/virtio_ring.c | 33 +++++++++++++++------------------ 1 file changed, 15 insertions(+), 18 deletions(-)