On Mon, Jun 29, 2020 at 03:03:56PM +0200, Christoph Hellwig wrote: > Add a new API to check if calls to dma_sync_single_for_{device,cpu} are > required for a given DMA streaming mapping. > > +:: > + > + bool > + dma_need_sync(struct device *dev, dma_addr_t dma_addr); > + > +Returns %true if dma_sync_single_for_{device,cpu} calls are required to > +transfer memory ownership. Returns %false if those calls can be skipped. Hi Christoph - Thie call above is for a specific dma_addr. For correctness, would I need to check every addr, or can I assume that for a specific memory type (pages returned from malloc), that the answer would be identical? -- Jonathan