In recent days, Samsung has been posting kernel patches pertaining to buffer synchronization support of the DMA-BUF
buffer sharing mechanism.
The work out of Samsung provides for buffer synchronization support for the DMA-BUF buffer sharing framework that's used for providing Optimus-like support with sharing graphics buffers between different GPUs/drivers and can also be used in the ARM world for sharing buffers between different SoC drivers.
Inki Dae explains on the mailing list
, "The purpose of this framework is not only to couple cache operations, and buffer access control to CPU and DMA but also to provide easy-to-use interfaces for device drivers and potentially user application (not implemented for user applications, yet). And this framework can be used for all dma devices using system memory as dma buffer, especially for most ARM based SoCs."