On Sat, Sep 18, 2021 at 07:18:43AM +0200, Christoph Hellwig wrote: > On Sat, Sep 18, 2021 at 12:22:47AM +0300, Mike Rapoport wrote: > > I did some digging and it seems that the most "generic" way to check if a > > page is in RAM is page_is_ram(). It's not 100% bullet proof as it'll give > > false negatives for architectures that do not register "System RAM", but > > those are not using dma_map_resource() anyway and, apparently, never would. > > The downside of page_is_ram is that it looks really expensiv for > something done at dma mapping time. Indeed :( But pfn_valid is plain wrong... I'll keep digging. -- Sincerely yours, Mike.
