On Thu, Feb 02, 2023 at 07:00:33PM +0800, Xuan Zhuo wrote: > In the process of dma sync, we involved whether virtio uses dma api. On > the other hand, it is also necessary to read vdev->dev.parent. So these > API has been introduced.
you don't need to repeat implementation here. just list the new APIs and how they will be used with premapped API. > Signed-off-by: Xuan Zhuo <[email protected]> > --- > drivers/virtio/virtio_ring.c | 61 ++++++++++++++++++++++++++++++++++++ > include/linux/virtio.h | 8 +++++ > 2 files changed, 69 insertions(+) > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > index 67eda7bc23ea..7b393133fd27 100644 > --- a/drivers/virtio/virtio_ring.c > +++ b/drivers/virtio/virtio_ring.c > @@ -3102,4 +3102,65 @@ void virtio_dma_unmap(struct device *dev, dma_addr_t > dma, unsigned int length, > } > EXPORT_SYMBOL_GPL(virtio_dma_unmap); > > +/** > + * virtio_dma_need_sync - check dma address need sync .... whether a dma address needs sync > + * @dev: virtio device > + * @addr: DMA address > + */ > +bool virtio_dma_need_sync(struct device *dev, dma_addr_t addr) > +{ > + struct virtio_device *vdev = dev_to_virtio(dev); > + > + if (!vring_use_dma_api(vdev)) > + return 0; > + > + return dma_need_sync(vdev->dev.parent, addr); > +} > +EXPORT_SYMBOL_GPL(virtio_dma_need_sync); > + > +/** > + * virtio_dma_sync_signle_range_for_cpu - dma sync for cpu > + * @dev: virtio device > + * @addr: DMA address > + * @offset: DMA address offset > + * @size: mem size for sync > + * @dir: DMA direction > + * > + * Before calling this function, use virtio_dma_need_sync() to confirm that > the > + * DMA address really needs to be synchronized > + */ > +void virtio_dma_sync_signle_range_for_cpu(struct device *dev, dma_addr_t > addr, > + unsigned long offset, size_t size, > + enum dma_data_direction dir) > +{ > + struct virtio_device *vdev = dev_to_virtio(dev); > + > + dma_sync_single_range_for_cpu(vdev->dev.parent, addr, offset, > + size, DMA_BIDIRECTIONAL); > +} > +EXPORT_SYMBOL_GPL(virtio_dma_sync_signle_range_for_cpu); > + > +/** > + * virtio_dma_sync_signle_range_for_device - dma sync for device > + * @dev: virtio device > + * @addr: DMA address > + * @offset: DMA address offset > + * @size: mem size for sync > + * @dir: DMA direction > + * > + * Before calling this function, use virtio_dma_need_sync() to confirm that > the > + * DMA address really needs to be synchronized > + */ > +void virtio_dma_sync_signle_range_for_device(struct device *dev, > + dma_addr_t addr, > + unsigned long offset, size_t size, > + enum dma_data_direction dir) > +{ > + struct virtio_device *vdev = dev_to_virtio(dev); > + > + dma_sync_single_range_for_device(vdev->dev.parent, addr, offset, > + size, DMA_BIDIRECTIONAL); > +} > +EXPORT_SYMBOL_GPL(virtio_dma_sync_signle_range_for_device); > + Pls document how these APIs are only for pre-mapped buffers, for non premapped virtio core handles DMA API internally. > MODULE_LICENSE("GPL"); > diff --git a/include/linux/virtio.h b/include/linux/virtio.h > index ce89126becc5..8c2fae318b0c 100644 > --- a/include/linux/virtio.h > +++ b/include/linux/virtio.h > @@ -227,4 +227,12 @@ dma_addr_t virtio_dma_map(struct device *dev, void > *addr, unsigned int length, > int virtio_dma_mapping_error(struct device *dev, dma_addr_t addr); > void virtio_dma_unmap(struct device *dev, dma_addr_t dma, unsigned int > length, > enum dma_data_direction dir); > +bool virtio_dma_need_sync(struct device *dev, dma_addr_t addr); > +void virtio_dma_sync_signle_range_for_cpu(struct device *dev, dma_addr_t > addr, > + unsigned long offset, size_t size, > + enum dma_data_direction dir); > +void virtio_dma_sync_signle_range_for_device(struct device *dev, > + dma_addr_t addr, > + unsigned long offset, size_t size, > + enum dma_data_direction dir); > #endif /* _LINUX_VIRTIO_H */ > -- > 2.32.0.3.g01195cf9f _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
