On Thu, 30 Nov 2023 04:45:58 -0500, "Michael S. Tsirkin" <mst@xxxxxxxxxx> wrote: > On Thu, Aug 10, 2023 at 08:30:56PM +0800, Xuan Zhuo wrote: > > 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 <xuanzhuo@xxxxxxxxxxxxxxxxx> > > --- > > 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); > > +} > > > Why did you use DMA_BIDIRECTIONAL here? > Why is "dir" ignored? This is a mistake. I see Jason has a fix patch. How can I help? Thanks. > > > > +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"); > > same question here. > > > 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 */ > > -- > > 2.32.0.3.g01195cf9f > >