On Thu, Sep 27, 2018 at 03:30:20PM +0100, Robin Murphy wrote:

quoted

  +static gfp_t __dma_direct_optimal_gfp_mask(struct device *dev, u64 
dma_mask,
+		u64 *phys_mask)
+{
+	if (force_dma_unencrypted())
+		*phys_mask = __dma_to_phys(dev, dma_mask);
+	else
+		*phys_mask = dma_to_phys(dev, dma_mask);

Maybe make phys_to_dma_direct() take u64 instead of phys_addr_t so we can 
reuse it here?

This is a dma_to_phys and not a phys_to_dma.