These API has been introduced:
* virtio_dma_need_sync
* virtio_dma_sync_single_range_for_cpu
* virtio_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 | 70 ++++++++++++++++++++++++++++++++++++
include/linux/virtio.h | 8 +++++
2 files changed, 78 insertions(+)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 855338609c7f..84129b8c3e2a 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -3264,4 +3264,74 @@ 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 a dma address needs sync
+ * @dev: virtio device
+ * @addr: DMA address
+ *
+ * This API is only for pre-mapped buffers, for non premapped buffers virtio
+ * core handles DMA API internally.
+ */
+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_single_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
+ *
+ * This API is only for pre-mapped buffers, for non premapped buffers virtio
+ * core handles DMA API internally.
+ */
+void virtio_dma_sync_single_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_single_range_for_cpu);
+
+/**
+ * virtio_dma_sync_single_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
+ *
+ * This API is only for pre-mapped buffers, for non premapped buffers virtio
+ * core handles DMA API internally.
+ */
+void virtio_dma_sync_single_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_single_range_for_device);
+
MODULE_LICENSE("GPL");
diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index b5fa71476737..d0e707d744a0 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -225,4 +225,12 @@ 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_single_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_single_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
Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
https://lists.linuxfoundation.org/mailman/listinfo/virtualization
