fbdev: add dma-buf support

Add support for the dma-buf exporter role to the frame buffer API. The
importer role isn't meaningful for frame buffer devices, as the frame
buffer device model doesn't allow using externally allocated memory.

Taken from an RFC on the linaro-mm-sig mailing list:

Signed-off-by: Guillaume Tucker <guillaume.tucker@arm.com>
[Ported to gem5's 4.3 kernel]
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
[Ported to gem5's 4.9 kernel. Added dep. on CONFIG_DMA_SHARED_BUFFER]
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
4 files changed