Commit 19d6634d authored by Dmitry Osipenko's avatar Dmitry Osipenko
Browse files

dma-buf: Add unlocked variant of attachment-mapping functions 



Add unlocked variant of dma_buf_map/unmap_attachment() that will
be used by drivers that don't take the reservation lock explicitly.

Acked-by: default avatarSumit Semwal <sumit.semwal@linaro.org>
Acked-by: default avatarChristian König <christian.koenig@amd.com>
Signed-off-by: default avatarDmitry Osipenko <dmitry.osipenko@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221017172229.42269-3-dmitry.osipenko@collabora.com
parent 56e5abba

drivers/dma-buf/dma-buf.c

+53 −0
Original line number Diff line number Diff line
@@ -1100,6 +1100,34 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach, 
}

EXPORT_SYMBOL_NS_GPL(dma_buf_map_attachment, DMA_BUF);



/**

 * dma_buf_map_attachment_unlocked - Returns the scatterlist table of the attachment;

 * mapped into _device_ address space. Is a wrapper for map_dma_buf() of the

 * dma_buf_ops.

 * @attach:	[in]	attachment whose scatterlist is to be returned

 * @direction:	[in]	direction of DMA transfer

 *

 * Unlocked variant of dma_buf_map_attachment().

 */

struct sg_table *

dma_buf_map_attachment_unlocked(struct dma_buf_attachment *attach,

				enum dma_data_direction direction)

{

	struct sg_table *sg_table;



	might_sleep();



	if (WARN_ON(!attach || !attach->dmabuf))

		return ERR_PTR(-EINVAL);



	dma_resv_lock(attach->dmabuf->resv, NULL);

	sg_table = dma_buf_map_attachment(attach, direction);

	dma_resv_unlock(attach->dmabuf->resv);



	return sg_table;

}

EXPORT_SYMBOL_NS_GPL(dma_buf_map_attachment_unlocked, DMA_BUF);



/**

 * dma_buf_unmap_attachment - unmaps and decreases usecount of the buffer;might

 * deallocate the scatterlist associated. Is a wrapper for unmap_dma_buf() of
@@ -1136,6 +1164,31 @@ void dma_buf_unmap_attachment(struct dma_buf_attachment *attach, 
}

EXPORT_SYMBOL_NS_GPL(dma_buf_unmap_attachment, DMA_BUF);



/**

 * dma_buf_unmap_attachment_unlocked - unmaps and decreases usecount of the buffer;might

 * deallocate the scatterlist associated. Is a wrapper for unmap_dma_buf() of

 * dma_buf_ops.

 * @attach:	[in]	attachment to unmap buffer from

 * @sg_table:	[in]	scatterlist info of the buffer to unmap

 * @direction:	[in]	direction of DMA transfer

 *

 * Unlocked variant of dma_buf_unmap_attachment().

 */

void dma_buf_unmap_attachment_unlocked(struct dma_buf_attachment *attach,

				       struct sg_table *sg_table,

				       enum dma_data_direction direction)

{

	might_sleep();



	if (WARN_ON(!attach || !attach->dmabuf || !sg_table))

		return;



	dma_resv_lock(attach->dmabuf->resv, NULL);

	dma_buf_unmap_attachment(attach, sg_table, direction);

	dma_resv_unlock(attach->dmabuf->resv);

}

EXPORT_SYMBOL_NS_GPL(dma_buf_unmap_attachment_unlocked, DMA_BUF);



/**

 * dma_buf_move_notify - notify attachments that DMA-buf is moving

 *

include/linux/dma-buf.h

+6 −0
Original line number Diff line number Diff line
@@ -627,6 +627,12 @@ int dma_buf_begin_cpu_access(struct dma_buf *dma_buf, 
			     enum dma_data_direction dir);

int dma_buf_end_cpu_access(struct dma_buf *dma_buf,

			   enum dma_data_direction dir);

struct sg_table *

dma_buf_map_attachment_unlocked(struct dma_buf_attachment *attach,

				enum dma_data_direction direction);

void dma_buf_unmap_attachment_unlocked(struct dma_buf_attachment *attach,

				       struct sg_table *sg_table,

				       enum dma_data_direction direction);



int dma_buf_mmap(struct dma_buf *, struct vm_area_struct *,

		 unsigned long);