Commit 8bd2f710 authored by Xuan Zhuo's avatar Xuan Zhuo Committed by Michael S. Tsirkin
Browse files

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: default avatarXuan Zhuo <xuanzhuo@linux.alibaba.com>
Message-Id: <20230810123057.43407-12-xuanzhuo@linux.alibaba.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent b6253b4e

drivers/virtio/virtio_ring.c

+76 −0
Original line number Diff line number Diff line
@@ -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");

include/linux/virtio.h

+8 −0
Original line number Diff line number Diff line
@@ -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 */