> 2023年2月21日 17:58,Christoph Hellwig <hch@xxxxxx> 写道: > > On Tue, Feb 21, 2023 at 12:46:10PM +0000, Jiaxun Yang wrote: >> dma_default_coherent can be useful for determine default coherency >> even on arches without noncoherent support. > > How? I just want to make this symbol always available so OF code can reference it on all arches.