Am 05.09.24 um 08:56 schrieb Jens Wiklander:
On Fri, Aug 30, 2024 at 10:47 AM Christian König christian.koenig@amd.com wrote:
Am 30.08.24 um 09:03 schrieb Jens Wiklander:
Add a no_map attribute to struct restricted_heap_attachment and struct restricted_heap to skip the call to dma_map_sgtable() if set. This avoids trying to map a dma-buf that doens't refer to memory accessible by the kernel.
You seem to have a misunderstanding here dma_map_sgtable() is called to map a table into IOMMU and not any kernel address space.
So please explain why you need that?
You're right, I had misunderstood dma_map_sgtable(). There's no need for the no_map attribute, so I'll remove it.
Perhaps you have a suggestion on how to fix a problem when using dma_map_sgtable()?
Without it, I'll have to assign a pointer to teedev->dev.dma_mask when using the restricted heap with the OP-TEE driver or there will be a warning in __dma_map_sg_attrs() ending with a failure when trying to register the dma-buf fd. OP-TEE is probed with a platform device, and taking the dma_mask pointer from that device works. Is that a good approach or is there a better way of assigning dma_mask?
Mhm, I don't know the full picture so I have to make some assumptions.
The teedev is just a virtual device which represents the restricted memory access paths of a real device?
If that is true then taking the dma-mask from the real device is most likely the right thing to do.
Regards, Christian.
Thanks, Jens
Regards, Christian.
Signed-off-by: Jens Wiklander jens.wiklander@linaro.org
drivers/dma-buf/heaps/restricted_heap.c | 17 +++++++++++++---- drivers/dma-buf/heaps/restricted_heap.h | 2 ++ 2 files changed, 15 insertions(+), 4 deletions(-)
diff --git a/drivers/dma-buf/heaps/restricted_heap.c b/drivers/dma-buf/heaps/restricted_heap.c index 8bc8a5e3f969..4bf28e3727ca 100644 --- a/drivers/dma-buf/heaps/restricted_heap.c +++ b/drivers/dma-buf/heaps/restricted_heap.c @@ -16,6 +16,7 @@ struct restricted_heap_attachment { struct sg_table *table; struct device *dev;
bool no_map;};
static int
@@ -54,6 +55,8 @@ restricted_heap_memory_free(struct restricted_heap *rheap, struct restricted_buf static int restricted_heap_attach(struct dma_buf *dmabuf, struct dma_buf_attachment *attachment) { struct restricted_buffer *restricted_buf = dmabuf->priv;
struct dma_heap *heap = restricted_buf->heap;struct restricted_heap *rheap = dma_heap_get_drvdata(heap); struct restricted_heap_attachment *a; struct sg_table *table;@@ -70,6 +73,7 @@ static int restricted_heap_attach(struct dma_buf *dmabuf, struct dma_buf_attachm sg_dma_mark_restricted(table->sgl); a->table = table; a->dev = attachment->dev;
a->no_map = rheap->no_map; attachment->priv = a; return 0;@@ -92,9 +96,12 @@ restricted_heap_map_dma_buf(struct dma_buf_attachment *attachment, struct sg_table *table = a->table; int ret;
ret = dma_map_sgtable(attachment->dev, table, direction, DMA_ATTR_SKIP_CPU_SYNC);if (ret)return ERR_PTR(ret);
if (!a->no_map) {ret = dma_map_sgtable(attachment->dev, table, direction,DMA_ATTR_SKIP_CPU_SYNC);if (ret)return ERR_PTR(ret);} return table;@@ -106,7 +113,9 @@ restricted_heap_unmap_dma_buf(struct dma_buf_attachment *attachment, struct sg_t
WARN_ON(a->table != table);
dma_unmap_sgtable(attachment->dev, table, direction, DMA_ATTR_SKIP_CPU_SYNC);
if (!a->no_map)dma_unmap_sgtable(attachment->dev, table, direction,DMA_ATTR_SKIP_CPU_SYNC);}
static int
diff --git a/drivers/dma-buf/heaps/restricted_heap.h b/drivers/dma-buf/heaps/restricted_heap.h index 7dec4b8a471b..94cc0842f70d 100644 --- a/drivers/dma-buf/heaps/restricted_heap.h +++ b/drivers/dma-buf/heaps/restricted_heap.h @@ -27,6 +27,8 @@ struct restricted_heap { unsigned long cma_paddr; unsigned long cma_size;
bool no_map;void *priv_data;