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Xuan Zhuo

2023-Feb-14 07:27 UTC

[PATCH vhost 08/10] virtio_ring: introduce dma sync api for virtio

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 at linux.alibaba.com>
---
 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

Jason Wang

2023-Feb-20 05:38 UTC

head link

[PATCH vhost 08/10] virtio_ring: introduce dma sync api for virtio

On Tue, Feb 14, 2023 at 3:27 PM Xuan Zhuo <xuanzhuo at linux.alibaba.com>
wrote:>
> These API has been introduced:
>
> * virtio_dma_need_sync
> * virtio_dma_sync_single_range_for_cpu
> * virtio_dma_sync_single_range_for_device
What's the advantages of exporting internal logic like
virtio_dma_need_sync() over hiding it in
virtio_dma_sync_single_range_for_cpu() and
virtio_dma_sync_single_range_for_device()?

Thanks

>
> These APIs can be used together with the premapped mechanism to sync the
> DMA address.
>
> Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
> ---
>  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 - Feb 2023 - [PATCH vhost 08/10] virtio_ring: introduce dma sync api for virtio

[PATCH vhost 08/10] virtio_ring: introduce dma sync api for virtio

[PATCH vhost 08/10] virtio_ring: introduce dma sync api for virtio