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Message-Id: <20230719040422.126357-3-xuanzhuo@linux.alibaba.com>
Date: Wed, 19 Jul 2023 12:04:14 +0800
From: Xuan Zhuo <xuanzhuo@...ux.alibaba.com>
To: virtualization@...ts.linux-foundation.org
Cc: "Michael S. Tsirkin" <mst@...hat.com>,
Jason Wang <jasowang@...hat.com>,
Xuan Zhuo <xuanzhuo@...ux.alibaba.com>,
"David S. Miller" <davem@...emloft.net>,
Eric Dumazet <edumazet@...gle.com>,
Jakub Kicinski <kuba@...nel.org>,
Paolo Abeni <pabeni@...hat.com>,
Alexei Starovoitov <ast@...nel.org>,
Daniel Borkmann <daniel@...earbox.net>,
Jesper Dangaard Brouer <hawk@...nel.org>,
John Fastabend <john.fastabend@...il.com>,
netdev@...r.kernel.org,
bpf@...r.kernel.org,
Christoph Hellwig <hch@...radead.org>
Subject: [PATCH vhost v12 02/10] virtio_ring: put mapping error check in vring_map_one_sg
This patch put the dma addr error check in vring_map_one_sg().
The benefits of doing this:
1. reduce one judgment of vq->use_dma_api.
2. make vring_map_one_sg more simple, without calling
vring_mapping_error to check the return value. simplifies subsequent
code
Signed-off-by: Xuan Zhuo <xuanzhuo@...ux.alibaba.com>
Acked-by: Jason Wang <jasowang@...hat.com>
---
drivers/virtio/virtio_ring.c | 37 +++++++++++++++++++++---------------
1 file changed, 22 insertions(+), 15 deletions(-)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index f8754f1d64d3..87d7ceeecdbd 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -355,9 +355,8 @@ static struct device *vring_dma_dev(const struct vring_virtqueue *vq)
}
/* Map one sg entry. */
-static dma_addr_t vring_map_one_sg(const struct vring_virtqueue *vq,
- struct scatterlist *sg,
- enum dma_data_direction direction)
+static int vring_map_one_sg(const struct vring_virtqueue *vq, struct scatterlist *sg,
+ enum dma_data_direction direction, dma_addr_t *addr)
{
if (!vq->use_dma_api) {
/*
@@ -366,7 +365,8 @@ static dma_addr_t vring_map_one_sg(const struct vring_virtqueue *vq,
* depending on the direction.
*/
kmsan_handle_dma(sg_page(sg), sg->offset, sg->length, direction);
- return (dma_addr_t)sg_phys(sg);
+ *addr = (dma_addr_t)sg_phys(sg);
+ return 0;
}
/*
@@ -374,9 +374,14 @@ static dma_addr_t vring_map_one_sg(const struct vring_virtqueue *vq,
* the way it expects (we don't guarantee that the scatterlist
* will exist for the lifetime of the mapping).
*/
- return dma_map_page(vring_dma_dev(vq),
+ *addr = dma_map_page(vring_dma_dev(vq),
sg_page(sg), sg->offset, sg->length,
direction);
+
+ if (dma_mapping_error(vring_dma_dev(vq), *addr))
+ return -ENOMEM;
+
+ return 0;
}
static dma_addr_t vring_map_single(const struct vring_virtqueue *vq,
@@ -588,8 +593,9 @@ static inline int virtqueue_add_split(struct 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))
+ dma_addr_t addr;
+
+ if (vring_map_one_sg(vq, sg, DMA_TO_DEVICE, &addr))
goto unmap_release;
prev = i;
@@ -603,8 +609,9 @@ static inline int virtqueue_add_split(struct virtqueue *_vq,
}
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))
+ dma_addr_t addr;
+
+ if (vring_map_one_sg(vq, sg, DMA_FROM_DEVICE, &addr))
goto unmap_release;
prev = i;
@@ -1281,9 +1288,8 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq,
for (n = 0; n < out_sgs + in_sgs; n++) {
for (sg = sgs[n]; sg; sg = sg_next(sg)) {
- addr = vring_map_one_sg(vq, sg, n < out_sgs ?
- DMA_TO_DEVICE : DMA_FROM_DEVICE);
- if (vring_mapping_error(vq, addr))
+ if (vring_map_one_sg(vq, sg, n < out_sgs ?
+ DMA_TO_DEVICE : DMA_FROM_DEVICE, &addr))
goto unmap_release;
desc[i].flags = cpu_to_le16(n < out_sgs ?
@@ -1428,9 +1434,10 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq,
c = 0;
for (n = 0; 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, n < out_sgs ?
- DMA_TO_DEVICE : DMA_FROM_DEVICE);
- if (vring_mapping_error(vq, addr))
+ dma_addr_t addr;
+
+ if (vring_map_one_sg(vq, sg, n < out_sgs ?
+ DMA_TO_DEVICE : DMA_FROM_DEVICE, &addr))
goto unmap_release;
flags = cpu_to_le16(vq->packed.avail_used_flags |
--
2.32.0.3.g01195cf9f
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