On Mon, Aug 30, 2021 at 10:39:11AM +0800, guangming.cao@xxxxxxxxxxxx wrote:
> From: Guangming Cao <Guangming.Cao@xxxxxxxxxxxx>
>
> When mapping the memory represented by a dma-buf into a device's
> address space, it might be desireable to map the memory with
> certain DMA attributes. Thus, introduce the dma_mapping_attrs
> field in the dma_buf_attachment structure so that when
> the memory is mapped with dma_buf_map_attachment, it is mapped
> with the desired DMA attributes.
>
> Signed-off-by: Isaac J. Manjarres <isaacm@xxxxxxxxxxxxxx>
> Signed-off-by: Sandeep Patil <sspatil@xxxxxxxxxx>
> Signed-off-by: Guangming Cao <Guangming.Cao@xxxxxxxxxxxx>
Can you pls include the code that's going to use this here too?
At a glance all the attributes you might want to set are supposed to be
under the control of the exporter, not the importer.
-Daniel
> ---
> drivers/dma-buf/heaps/cma_heap.c | 6 ++++--
> drivers/dma-buf/heaps/system_heap.c | 6 ++++--
> include/linux/dma-buf.h | 3 +++
> 3 files changed, 11 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/dma-buf/heaps/cma_heap.c b/drivers/dma-buf/heaps/cma_heap.c
> index 0c05b79870f9..2c9feb3bfc3e 100644
> --- a/drivers/dma-buf/heaps/cma_heap.c
> +++ b/drivers/dma-buf/heaps/cma_heap.c
> @@ -99,9 +99,10 @@ static struct sg_table *cma_heap_map_dma_buf(struct dma_buf_attachment *attachme
> {
> struct dma_heap_attachment *a = attachment->priv;
> struct sg_table *table = &a->table;
> + int attrs = attachment->dma_map_attrs;
> int ret;
>
> - ret = dma_map_sgtable(attachment->dev, table, direction, 0);
> + ret = dma_map_sgtable(attachment->dev, table, direction, attrs);
> if (ret)
> return ERR_PTR(-ENOMEM);
> a->mapped = true;
> @@ -113,9 +114,10 @@ static void cma_heap_unmap_dma_buf(struct dma_buf_attachment *attachment,
> enum dma_data_direction direction)
> {
> struct dma_heap_attachment *a = attachment->priv;
> + int attrs = attachment->dma_map_attrs;
>
> a->mapped = false;
> - dma_unmap_sgtable(attachment->dev, table, direction, 0);
> + dma_unmap_sgtable(attachment->dev, table, direction, attrs);
> }
>
> static int cma_heap_dma_buf_begin_cpu_access(struct dma_buf *dmabuf,
> diff --git a/drivers/dma-buf/heaps/system_heap.c b/drivers/dma-buf/heaps/system_heap.c
> index 23a7e74ef966..fc7b1e02988e 100644
> --- a/drivers/dma-buf/heaps/system_heap.c
> +++ b/drivers/dma-buf/heaps/system_heap.c
> @@ -130,9 +130,10 @@ static struct sg_table *system_heap_map_dma_buf(struct dma_buf_attachment *attac
> {
> struct dma_heap_attachment *a = attachment->priv;
> struct sg_table *table = a->table;
> + int attrs = attachment->dma_map_attrs;
> int ret;
>
> - ret = dma_map_sgtable(attachment->dev, table, direction, 0);
> + ret = dma_map_sgtable(attachment->dev, table, direction, attrs);
> if (ret)
> return ERR_PTR(ret);
>
> @@ -145,9 +146,10 @@ static void system_heap_unmap_dma_buf(struct dma_buf_attachment *attachment,
> enum dma_data_direction direction)
> {
> struct dma_heap_attachment *a = attachment->priv;
> + int attrs = attachment->dma_map_attrs;
>
> a->mapped = false;
> - dma_unmap_sgtable(attachment->dev, table, direction, 0);
> + dma_unmap_sgtable(attachment->dev, table, direction, attrs);
> }
>
> static int system_heap_dma_buf_begin_cpu_access(struct dma_buf *dmabuf,
> diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h
> index efdc56b9d95f..4d650731766e 100644
> --- a/include/linux/dma-buf.h
> +++ b/include/linux/dma-buf.h
> @@ -379,6 +379,8 @@ struct dma_buf_attach_ops {
> * @importer_ops: importer operations for this attachment, if provided
> * dma_buf_map/unmap_attachment() must be called with the dma_resv lock held.
> * @importer_priv: importer specific attachment data.
> + * @dma_map_attrs: DMA attributes to be used when the exporter maps the buffer
> + * through dma_buf_map_attachment.
> *
> * This structure holds the attachment information between the dma_buf buffer
> * and its user device(s). The list contains one attachment struct per device
> @@ -399,6 +401,7 @@ struct dma_buf_attachment {
> const struct dma_buf_attach_ops *importer_ops;
> void *importer_priv;
> void *priv;
> + unsigned long dma_map_attrs;
> };
>
> /**
> --
> 2.17.1
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
