Re: helping with remapping vmem for dma

[Christoph Hellwig]

On Wed, Jun 15, 2022 at 02:15:33PM +0100, Robin Murphy wrote:
> Put simply, if you want to call dma_map_single() on a buffer, then that 
> buffer needs to be allocated with kmalloc() (or technically alloc_pages(), 
> but then dma_map_page() would make more sense when dealing with entire 
> pages.

Yes.  It sounds like the memory here comes from the dma coherent
allocator, in which case the code need to use the address returned
by that and not create another mapping.