On Tue, May 08, 2018 at 11:05:20AM +0100, Robin Murphy wrote:

On 24/04/18 15:02, Christoph Hellwig wrote:

quoted

Only used by the AMD GART driver, which must be built in.

FWIW debug_dma_dump_mappings() is also called by the Intel VT-d driver, but 
the same reasoning still applies.

I'll update the changelog.

This does rather beg the question of 
whether it's right to have bits of low-level dma-debug internals *only* 
called by a couple of IOMMU drivers, but that can wait for another day.

My gut feeling is that it is wrong, but I didn't have time to look into
the details and history of how this happened.