On Tue, 2021-08-31 at 14:47 +0200, Daniel Vetter wrote: > 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 > Hi Daniel, Sorry for late. Currently I couldn't upload the coding going to use this part because of some miscellaneous reasons. Just as I said in commit message, for dma_heap, users can't skip cache sync or other opetrations when map iova[dma_buf_map_attachment] by fill (struct dma_buf_attachment).dma_map_attrs, it's not dma_map_attrs expected(link: https://github.com/torvalds/linux/blob/master/Documentation/core-api/dma-attributes.rst#dma_attr_skip_cpu_sync ). Correspondingly, if they use dma_buf to map iova[dma_buf_map_attrs], they will not meet this issue. So, I think it's a design flaw for dma_heap. BRs! Guangming > > --- > > 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 > > > >
