I’m allocating NvBuffer via NvBufferCreateEx and then use underlying dmabuf in my device driver. I want to apply DMA mask to NvBuffer so that physical address of dmabuf doesn’t exceed 32bit. How can I do that?
We may not support the case since the L4T releases are on 64-bit system. Is there a reason you would need this?
Well, as nvmap_dmabuf is an exporter of DMA buffer (when using NvBufferCreateEx) I would expect it to check DMA mask of a device that is trying to attach to it. The following quote is from dma-buf.h:
The exporter should also in general check whether the current
allocation fullfills the DMA constraints of the new device. If this
is not the case, and the allocation cannot be moved, it should also
fail the attach operation.
Apparently it’s not how nvmap works, am I correct?