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authorTiwei Bie <tiwei.bie@intel.com>2018-11-21 18:03:26 +0800
committerDavid S. Miller <davem@davemloft.net>2018-11-26 22:17:39 -0800
commitfb3fba6b162aaa42aeba6e9034f3e92716c2a749 (patch)
tree1c095a49d00f84de4e3184ddb896de36bcb92ef3 /drivers/virtio
parentd79dca75c79680f52a27a7ee1b6ae75066f36b3e (diff)
downloadlinux-fb3fba6b162aaa42aeba6e9034f3e92716c2a749.tar.bz2
virtio_ring: cache whether we will use DMA API
Cache whether we will use DMA API, instead of doing the check every time. We are going to check whether DMA API is used more often in packed ring. Signed-off-by: Tiwei Bie <tiwei.bie@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/virtio')
-rw-r--r--drivers/virtio/virtio_ring.c12
1 files changed, 8 insertions, 4 deletions
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index d00a87909a7e..aafe1969b45e 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -86,6 +86,9 @@ struct vring_desc_state_split {
struct vring_virtqueue {
struct virtqueue vq;
+ /* Is DMA API used? */
+ bool use_dma_api;
+
/* Can we use weak barriers? */
bool weak_barriers;
@@ -262,7 +265,7 @@ static dma_addr_t vring_map_one_sg(const struct vring_virtqueue *vq,
struct scatterlist *sg,
enum dma_data_direction direction)
{
- if (!vring_use_dma_api(vq->vq.vdev))
+ if (!vq->use_dma_api)
return (dma_addr_t)sg_phys(sg);
/*
@@ -279,7 +282,7 @@ static dma_addr_t vring_map_single(const struct vring_virtqueue *vq,
void *cpu_addr, size_t size,
enum dma_data_direction direction)
{
- if (!vring_use_dma_api(vq->vq.vdev))
+ if (!vq->use_dma_api)
return (dma_addr_t)virt_to_phys(cpu_addr);
return dma_map_single(vring_dma_dev(vq),
@@ -289,7 +292,7 @@ static dma_addr_t vring_map_single(const struct vring_virtqueue *vq,
static int vring_mapping_error(const struct vring_virtqueue *vq,
dma_addr_t addr)
{
- if (!vring_use_dma_api(vq->vq.vdev))
+ if (!vq->use_dma_api)
return 0;
return dma_mapping_error(vring_dma_dev(vq), addr);
@@ -305,7 +308,7 @@ static void vring_unmap_one_split(const struct vring_virtqueue *vq,
{
u16 flags;
- if (!vring_use_dma_api(vq->vq.vdev))
+ if (!vq->use_dma_api)
return;
flags = virtio16_to_cpu(vq->vq.vdev, desc->flags);
@@ -1202,6 +1205,7 @@ struct virtqueue *__vring_new_virtqueue(unsigned int index,
vq->broken = false;
vq->last_used_idx = 0;
vq->num_added = 0;
+ vq->use_dma_api = vring_use_dma_api(vdev);
list_add_tail(&vq->vq.list, &vdev->vqs);
#ifdef DEBUG
vq->in_use = false;