On 20.02.20 17:11, Christoph Hellwig wrote: > On Thu, Feb 20, 2020 at 05:06:05PM +0100, Halil Pasic wrote: >> Currently force_dma_unencrypted() is only used by the direct >> implementation of the DMA API, and thus resides in dma-direct.h. But >> there is nothing dma-direct specific about it: if one was -- for >> whatever reason -- to implement custom DMA ops that have to in the >> encrypted/protected scenarios dma-direct currently deals with, one would >> need exactly this kind of information. > > I really don't think it has business being anywhre else, and your completely > bogus second patch just proves the point. >From a users perspective it makes absolutely perfect sense to use the bounce buffers when they are NEEDED. Forcing the user to specify iommu_platform just because you need bounce buffers really feels wrong. And obviously we have a severe performance issue because of the indirections. Now: I understand that you want to get this fixes differently, but maybe you could help to outline how this could be fixed proper. Christian
