Two patches to implement a generic framework for dma-buf to support local private interconnects, in particular interconnects that are not driver-private.
The interconnect support is negotiated as part of an attachment and is not a property of the dma-buf itself. Just like pcie p2p support. The first patch adds members to the dma_buf_attach_ops and to the dma_buf_attachment structure. These are needed for generic check of interconnect support, typically when an interconnect is shared between drivers. For truly driver-private interconnects they are not strictly needed, but still could be convenient. The second patch implements an interconnect negotiation for xe, without actually changing the protocol itself from pcie_p2p. Just as an example. This patch is not intended to be merged. Note: This RFC only deals with interconnect negotiation. The attachment state and what data-structure to use to convey the mapping information is not dealt with in this RFC. v2: - Get rid of void pointers and instead provide generic structures that are intended to be embedded / subclassed for each interconnect implementation. Thomas Hellström (2): dma-buf: Add support for private interconnects drm/xe/dma-buf: Add generic interconnect support framework drivers/gpu/drm/xe/tests/xe_dma_buf.c | 12 ++--- drivers/gpu/drm/xe/xe_dma_buf.c | 73 ++++++++++++++++++++++++--- drivers/gpu/drm/xe/xe_dma_buf.h | 1 - drivers/gpu/drm/xe/xe_interconnect.h | 31 ++++++++++++ include/linux/dma-buf.h | 51 +++++++++++++++++++ 5 files changed, 155 insertions(+), 13 deletions(-) create mode 100644 drivers/gpu/drm/xe/xe_interconnect.h -- 2.51.0
