Hi everybody,
core idea in this patch set is that DMA-buf importers can now provide an optional invalidate callback. Using this callback and the reservation object exporters can now avoid pinning DMA-buf memory for a long time while sharing it between devices.
I've already send out an older version roughly a year ago, but didn't had time to further look into cleaning this up.
The last time a major problem was that we would had to fix up all drivers implementing DMA-buf at once.
Now I avoid this by allowing mappings to be cached in the DMA-buf attachment and so driver can optionally move over to the new interface one by one.
This is also a prerequisite to my patchset enabling sharing of device memory with DMA-buf.
Please review and/or comment, Christian.