diff mbox series

[07/33] virtio_ring: add api virtio_dma_map() for advance dma

Message ID 20230202110058.130695-8-xuanzhuo@linux.alibaba.com (mailing list archive)
State Changes Requested
Headers show
Series virtio-net: support AF_XDP zero copy | expand

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netdev/patch_count fail Series longer than 15 patches (and no cover letter)
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Commit Message

Xuan Zhuo Feb. 2, 2023, 11 a.m. UTC 
Added virtio_dma_map() to map DMA addresses for virtual memory in
advance. The purpose of adding this function is to check
vring_use_dma_api() for virtio dma operation and get vdev->dev.parent as
the parameter of dma_map_page().

Added virtio_dma_unmap() for unmap DMA address.

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
---
 drivers/virtio/virtio_ring.c | 80 ++++++++++++++++++++++++++++++++++++
 include/linux/virtio.h       |  9 ++++
 2 files changed, 89 insertions(+)

Comments

Michael S. Tsirkin Feb. 3, 2023, 9:07 a.m. UTC | #1 
On Thu, Feb 02, 2023 at 07:00:32PM +0800, Xuan Zhuo wrote:
> Added virtio_dma_map() to map DMA addresses for virtual memory in
> advance. The purpose of adding this function is to check
> vring_use_dma_api() for virtio dma operation and get vdev->dev.parent as
> the parameter of dma_map_page().

No this looks like the implementation not the purpose.
I am guessing the purpose is to keep memory mapped
across multiple add/get buf operations right?

> Added virtio_dma_unmap() for unmap DMA address.
> 
> Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> ---
>  drivers/virtio/virtio_ring.c | 80 ++++++++++++++++++++++++++++++++++++
>  include/linux/virtio.h       |  9 ++++
>  2 files changed, 89 insertions(+)
> 
> diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
> index 7dfce7001f9f..67eda7bc23ea 100644
> --- a/drivers/virtio/virtio_ring.c
> +++ b/drivers/virtio/virtio_ring.c
> @@ -3022,4 +3022,84 @@ const struct vring *virtqueue_get_vring(struct virtqueue *vq)
>  }
>  EXPORT_SYMBOL_GPL(virtqueue_get_vring);
>  
> +/**
> + * virtio_dma_map_page - get the DMA addr of the memory for virtio device
> + * @dev: virtio device
> + * @page: the page of the memory to DMA
> + * @offset: the offset of the memory inside page
> + * @length: memory length
> + * @dir: DMA direction
> + *
> + * Returns the DMA addr. DMA_MAPPING_ERROR means error.
> + */
> +dma_addr_t virtio_dma_map_page(struct device *dev, struct page *page, size_t offset,
> +			       unsigned int length, enum dma_data_direction dir)
> +{
> +	struct virtio_device *vdev = dev_to_virtio(dev);
> +
> +	if (!vring_use_dma_api(vdev))
> +		return page_to_phys(page) + offset;
> +
> +	return dma_map_page(vdev->dev.parent, page, offset, length, dir);
> +}
> +
> +/**
> + * virtio_dma_map - get the DMA addr of the memory for virtio device
> + * @dev: virtio device
> + * @addr: the addr to DMA
> + * @length: memory length
> + * @dir: DMA direction
> + *
> + * Returns the DMA addr.
> + */
> +dma_addr_t virtio_dma_map(struct device *dev, void *addr, unsigned int length,
> +			  enum dma_data_direction dir)
> +{
> +	struct page *page;
> +	size_t offset;
> +
> +	page = virt_to_page(addr);
> +	offset = offset_in_page(addr);
> +
> +	return virtio_dma_map_page(dev, page, offset, length, dir);
> +}
> +EXPORT_SYMBOL_GPL(virtio_dma_map);
> +
> +/**
> + * virtio_dma_mapping_error - check dma address
> + * @dev: virtio device
> + * @addr: DMA address
> + *
> + * Returns 0 means dma valid. Other means invalid dma address.
> + */
> +int virtio_dma_mapping_error(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_mapping_error(vdev->dev.parent, addr);
> +}
> +EXPORT_SYMBOL_GPL(virtio_dma_mapping_error);
> +
> +/**
> + * virtio_dma_unmap - unmap DMA addr
> + * @dev: virtio device
> + * @dma: DMA address
> + * @length: memory length
> + * @dir: DMA direction
> + */
> +void virtio_dma_unmap(struct device *dev, dma_addr_t dma, unsigned int length,
> +		      enum dma_data_direction dir)
> +{
> +	struct virtio_device *vdev = dev_to_virtio(dev);
> +
> +	if (!vring_use_dma_api(vdev))
> +		return;
> +
> +	dma_unmap_page(vdev->dev.parent, dma, length, dir);
> +}
> +EXPORT_SYMBOL_GPL(virtio_dma_unmap);
> +
>  MODULE_LICENSE("GPL");
> diff --git a/include/linux/virtio.h b/include/linux/virtio.h
> index 3ca2edb1aef3..ce89126becc5 100644
> --- a/include/linux/virtio.h
> +++ b/include/linux/virtio.h
> @@ -9,6 +9,7 @@
>  #include <linux/device.h>
>  #include <linux/mod_devicetable.h>
>  #include <linux/gfp.h>
> +#include <linux/dma-mapping.h>
>  
>  /**
>   * struct virtqueue - a queue to register buffers for sending or receiving.
> @@ -218,4 +219,12 @@ void unregister_virtio_driver(struct virtio_driver *drv);
>  #define module_virtio_driver(__virtio_driver) \
>  	module_driver(__virtio_driver, register_virtio_driver, \
>  			unregister_virtio_driver)
> +
> +dma_addr_t virtio_dma_map_page(struct device *dev, struct page *page, size_t offset,
> +			       unsigned int length, enum dma_data_direction dir);
> +dma_addr_t virtio_dma_map(struct device *dev, void *addr, unsigned int length,
> +			  enum dma_data_direction dir);
> +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);
>  #endif /* _LINUX_VIRTIO_H */
> -- 
> 2.32.0.3.g01195cf9f
diff mbox series

Patch

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 7dfce7001f9f..67eda7bc23ea 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -3022,4 +3022,84 @@  const struct vring *virtqueue_get_vring(struct virtqueue *vq)
 }
 EXPORT_SYMBOL_GPL(virtqueue_get_vring);
 
+/**
+ * virtio_dma_map_page - get the DMA addr of the memory for virtio device
+ * @dev: virtio device
+ * @page: the page of the memory to DMA
+ * @offset: the offset of the memory inside page
+ * @length: memory length
+ * @dir: DMA direction
+ *
+ * Returns the DMA addr. DMA_MAPPING_ERROR means error.
+ */
+dma_addr_t virtio_dma_map_page(struct device *dev, struct page *page, size_t offset,
+			       unsigned int length, enum dma_data_direction dir)
+{
+	struct virtio_device *vdev = dev_to_virtio(dev);
+
+	if (!vring_use_dma_api(vdev))
+		return page_to_phys(page) + offset;
+
+	return dma_map_page(vdev->dev.parent, page, offset, length, dir);
+}
+
+/**
+ * virtio_dma_map - get the DMA addr of the memory for virtio device
+ * @dev: virtio device
+ * @addr: the addr to DMA
+ * @length: memory length
+ * @dir: DMA direction
+ *
+ * Returns the DMA addr.
+ */
+dma_addr_t virtio_dma_map(struct device *dev, void *addr, unsigned int length,
+			  enum dma_data_direction dir)
+{
+	struct page *page;
+	size_t offset;
+
+	page = virt_to_page(addr);
+	offset = offset_in_page(addr);
+
+	return virtio_dma_map_page(dev, page, offset, length, dir);
+}
+EXPORT_SYMBOL_GPL(virtio_dma_map);
+
+/**
+ * virtio_dma_mapping_error - check dma address
+ * @dev: virtio device
+ * @addr: DMA address
+ *
+ * Returns 0 means dma valid. Other means invalid dma address.
+ */
+int virtio_dma_mapping_error(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_mapping_error(vdev->dev.parent, addr);
+}
+EXPORT_SYMBOL_GPL(virtio_dma_mapping_error);
+
+/**
+ * virtio_dma_unmap - unmap DMA addr
+ * @dev: virtio device
+ * @dma: DMA address
+ * @length: memory length
+ * @dir: DMA direction
+ */
+void virtio_dma_unmap(struct device *dev, dma_addr_t dma, unsigned int length,
+		      enum dma_data_direction dir)
+{
+	struct virtio_device *vdev = dev_to_virtio(dev);
+
+	if (!vring_use_dma_api(vdev))
+		return;
+
+	dma_unmap_page(vdev->dev.parent, dma, length, dir);
+}
+EXPORT_SYMBOL_GPL(virtio_dma_unmap);
+
 MODULE_LICENSE("GPL");
diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index 3ca2edb1aef3..ce89126becc5 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -9,6 +9,7 @@ 
 #include <linux/device.h>
 #include <linux/mod_devicetable.h>
 #include <linux/gfp.h>
+#include <linux/dma-mapping.h>
 
 /**
  * struct virtqueue - a queue to register buffers for sending or receiving.
@@ -218,4 +219,12 @@  void unregister_virtio_driver(struct virtio_driver *drv);
 #define module_virtio_driver(__virtio_driver) \
 	module_driver(__virtio_driver, register_virtio_driver, \
 			unregister_virtio_driver)
+
+dma_addr_t virtio_dma_map_page(struct device *dev, struct page *page, size_t offset,
+			       unsigned int length, enum dma_data_direction dir);
+dma_addr_t virtio_dma_map(struct device *dev, void *addr, unsigned int length,
+			  enum dma_data_direction dir);
+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);
 #endif /* _LINUX_VIRTIO_H */