On 25/02/2016 01:45, Stephen Bates wrote: > Great, we hope to have the RFC soon. It will be able to accept different flags for devm_memremap() call with regards to caching. Though one question I have is when does the caching flag affect Peer-2-Peer memory accesses? I can see caching causing issues when performing accesses from the CPU but P2P accesses should bypass any caches in the system? I don't think the caching flag will affect peer to peer directly, but we need to keep the BAR mapped to the host the same way it is today. If we change the driver to map page structs returned from devm_memremap_pages() instead of using io_remap_pfn_range() it needs to continue working with host uses and not only with peers. Regards, Haggai -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>