From 8bd2f71054bd0bc997833e9825143672eb7e2801 Mon Sep 17 00:00:00 2001 From: Xuan Zhuo Date: Thu, 10 Aug 2023 20:30:56 +0800 Subject: virtio_ring: introduce dma sync api for virtqueue These API has been introduced: * virtqueue_dma_need_sync * virtqueue_dma_sync_single_range_for_cpu * virtqueue_dma_sync_single_range_for_device These APIs can be used together with the premapped mechanism to sync the DMA address. Signed-off-by: Xuan Zhuo Message-Id: <20230810123057.43407-12-xuanzhuo@linux.alibaba.com> Signed-off-by: Michael S. Tsirkin --- drivers/virtio/virtio_ring.c | 76 ++++++++++++++++++++++++++++++++++++++++++++ include/linux/virtio.h | 8 +++++ 2 files changed, 84 insertions(+) diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 916479c9c72c..81ecb29c88f1 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -3175,4 +3175,80 @@ int virtqueue_dma_mapping_error(struct virtqueue *_vq, dma_addr_t addr) } EXPORT_SYMBOL_GPL(virtqueue_dma_mapping_error); +/** + * virtqueue_dma_need_sync - check a dma address needs sync + * @_vq: the struct virtqueue we're talking about. + * @addr: DMA address + * + * Check if the dma address mapped by the virtqueue_dma_map_* APIs needs to be + * synchronized + * + * return bool + */ +bool virtqueue_dma_need_sync(struct virtqueue *_vq, dma_addr_t addr) +{ + struct vring_virtqueue *vq = to_vvq(_vq); + + if (!vq->use_dma_api) + return false; + + return dma_need_sync(vring_dma_dev(vq), addr); +} +EXPORT_SYMBOL_GPL(virtqueue_dma_need_sync); + +/** + * virtqueue_dma_sync_single_range_for_cpu - dma sync for cpu + * @_vq: the struct virtqueue we're talking about. + * @addr: DMA address + * @offset: DMA address offset + * @size: buf size for sync + * @dir: DMA direction + * + * Before calling this function, use virtqueue_dma_need_sync() to confirm that + * the DMA address really needs to be synchronized + * + */ +void virtqueue_dma_sync_single_range_for_cpu(struct virtqueue *_vq, + dma_addr_t addr, + unsigned long offset, size_t size, + enum dma_data_direction dir) +{ + struct vring_virtqueue *vq = to_vvq(_vq); + struct device *dev = vring_dma_dev(vq); + + if (!vq->use_dma_api) + return; + + dma_sync_single_range_for_cpu(dev, addr, offset, size, + DMA_BIDIRECTIONAL); +} +EXPORT_SYMBOL_GPL(virtqueue_dma_sync_single_range_for_cpu); + +/** + * virtqueue_dma_sync_single_range_for_device - dma sync for device + * @_vq: the struct virtqueue we're talking about. + * @addr: DMA address + * @offset: DMA address offset + * @size: buf size for sync + * @dir: DMA direction + * + * Before calling this function, use virtqueue_dma_need_sync() to confirm that + * the DMA address really needs to be synchronized + */ +void virtqueue_dma_sync_single_range_for_device(struct virtqueue *_vq, + dma_addr_t addr, + unsigned long offset, size_t size, + enum dma_data_direction dir) +{ + struct vring_virtqueue *vq = to_vvq(_vq); + struct device *dev = vring_dma_dev(vq); + + if (!vq->use_dma_api) + return; + + dma_sync_single_range_for_device(dev, addr, offset, size, + DMA_BIDIRECTIONAL); +} +EXPORT_SYMBOL_GPL(virtqueue_dma_sync_single_range_for_device); + MODULE_LICENSE("GPL"); diff --git a/include/linux/virtio.h b/include/linux/virtio.h index 79e3c74391e0..1311a7fbe675 100644 --- a/include/linux/virtio.h +++ b/include/linux/virtio.h @@ -220,4 +220,12 @@ void virtqueue_dma_unmap_single_attrs(struct virtqueue *_vq, dma_addr_t addr, size_t size, enum dma_data_direction dir, unsigned long attrs); int virtqueue_dma_mapping_error(struct virtqueue *_vq, dma_addr_t addr); + +bool virtqueue_dma_need_sync(struct virtqueue *_vq, dma_addr_t addr); +void virtqueue_dma_sync_single_range_for_cpu(struct virtqueue *_vq, dma_addr_t addr, + unsigned long offset, size_t size, + enum dma_data_direction dir); +void virtqueue_dma_sync_single_range_for_device(struct virtqueue *_vq, dma_addr_t addr, + unsigned long offset, size_t size, + enum dma_data_direction dir); #endif /* _LINUX_VIRTIO_H */ -- cgit v1.2.3