From 0e27fa6ddeb0e070398692e369ce52fa91f9442d Mon Sep 17 00:00:00 2001 From: Xuan Zhuo Date: Thu, 10 Aug 2023 20:30:47 +0800 Subject: [PATCH] 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 Acked-by: Jason Wang Message-Id: <20230810123057.43407-3-xuanzhuo@linux.alibaba.com> Signed-off-by: Michael S. Tsirkin --- 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 f8754f1..87d7cee 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 | -- 2.7.4